Lens driving apparatus and its manufacturing method

0001The present application claims priority under 35 U.S.C. §119 to Japanese application 2006-303177 filed on Nov. 8, 2006, the contents of which are incorporated herein by reference.

FIELD OF INVENTION

0002The present invention relates to the field of a lens driving apparatus that drives lenses in the optical axis direction to image a photographic subject and related manufacturing methods.

BACKGROUND

0003Camera phones having a camera function and digital cameras have been widely available in recent years, and cameras installed in such mobile apparatuses have a lens driving apparatus for driving lenses to move in the optical axis direction. One such lens driving apparatus has been proposed that has a movable body holding lenses, a fixed body for supporting the movable body via two flat springs to move in the optical axis direction, the two flat springs being positioned at two places distanced in the optical axis direction, and a magnetic drive mechanism for driving the movable body in the optical axis direction. Another configuration has also been proposed in which two coil end portions pulled out from the coils are respectively connected to the two flat springs so that current is supplied to the coils via the two flat springs (see Patent References 1 and 2). <ul id="ul0001" list-style="none"><li id="ul0001-0001" num="0004">[Patent Reference 1] Japanese Unexamined Patent Application (Tokkai) NO. 2005-128392</li><li id="ul0001-0002" num="0005">[Patent Reference 2] Japanese Unexamined Patent Application (Tokkai) NO. 2006-201525</li></ul>

0006However, in the lens driving apparatus disclosed in the above-mentioned patent references, it is necessary to supply electricity to the two flat springs that are distanced from each other in the optical axis direction; therefore, the apparatus is configured such that terminals are positioned at two places which are distanced from each other in the optical axis direction or one of the terminals is pulled around to the vicinity of the other terminal. In the former case, the wiring pattern becomes more complicated on the substrate for current supply to the terminals; in the latter case, in a downsized lens driving apparatus, enough space cannot be obtained for pulling the terminals around.

0007Considering the above problems, an objective of the present invention is to provide a lens driving apparatus in which current can be easily supplied to the coils provided to the movable body, and to provide its manufacturing method.

SUMMARY

0008To achieve the above, an embodiment of the present invention may feature a lens driving apparatus that comprises a movable body holding lenses, a fixed body for supporting the movable body via a spring member to move in the optical axis direction, and a magnetic drive mechanism which has coils held by the movable body and drives the movable body in the optical axis direction; wherein the spring member is configured with a plurality of spring pieces which are electrically divided at one place in the optical axis direction, and a plurality of coil end portions pulled out from the coils are respectively and electrically connected to different spring pieces of a plurality of spring pieces from each other.

0009In at least an embodiment of the present invention, the spring member may be divided into a plurality of spring pieces at one place in the optical direction and these spring pieces are used for current supply; therefore, current can be supplied at only one place in the optical axis direction to supply current to the coils. Therefore, there is no need to supply current at two places which are distanced from each other in the optical axis direction and no need to pull around one of the terminals to the vicinity of the other terminal in the optical axis direction. Thus, current can be easily supplied to the coils arranged to the movable body.

0010In at least an embodiment of the present invention, the spring member may be configured with a first spring member and a second spring member positioned at two places which are distanced from each other in the optical axis direction, and either the first spring member or the second spring member is divided into a plurality of spring pieces.

0011In this case, it is preferred that the other spring member, the first spring member or the second spring member [which is not divided], have openings formed for the coil end portions pulled out from the coils to pass at the positions away from the spring piece.

0012In at least an embodiment of the present invention, it is preferred that the second spring member be arranged on the photographic subject side and the first spring member be arranged on the side opposite from the photographic subject side, and the first spring member be divided into a plurality of spring pieces. Other electrical wiring such as the arrangement of an image pick-up device needs to be done on the side opposite from the photographic subject side; therefore, by gathering the wiring locations on the side opposite from the photographic subject side, wiring space can be reduced, increasing efficiency in wiring.

0013In at least an embodiment of the present invention, it is preferred that the first spring member and the second spring member be composed of different materials. In this way, the spring member that is divided into the spring pieces can be formed of a material that can be easily bent and cut off by folding, machine cutting or laser fusing while the spring member that will not be divided can be composed of a material that enhances the spring property.

0014In at least an embodiment of the present invention, it is preferred that a terminal for external power supply be formed integrally with the spring piece. In this way, there is no need to provide an additional terminal.

0015In at least an embodiment of the present invention, it is preferred that, one of the coil end portions pulled out from the coils, which is pulled out at the position away from the spring piece is passed through a groove-like guide portion extending in the optical axis direction on the outer peripheral face of the movable body and pulled around to the spring piece. In this way, there is no need to obtain additional space for pulling around the coil end portion.

0016In at least an embodiment of the present invention, the coil is configured with the first coil and second coil positioned at two places distanced from each other in the optical axis direction, and the first coil and the second coil are connected with each other by coil end portions thereof on one ends and coil end portions on the other ends are electrically connected to the spring pieces.

0017In at least an embodiment of the present invention, a configuration may be used in which the connection portion of the coil end portions on one ends are electrically connected to the spring piece which is different from the one connected to the coil end portions on the other ends.

0018In at least an embodiment of the present invention, a configuration may be used in which a plurality of spring pieces include a spring piece that is electrically connected to a back yoke constituting the magnetic drive mechanism, and a ground potential is applied to the spring piece. In this way, a shield structure using the back yoke can be easily configured.

0019In at least an embodiment of the present invention, it is preferred that the ends of a plurality of spring pieces have a cutting trace.

0020At least an embodiment of the present invention features a method of manufacturing a lens driving apparatus that comprises a movable body holding lenses, a fixed body for supporting the movable body via a spring member to move in the optical axis direction, and a magnetic drive mechanism which is provided with coils held by the movable body and drives the movable body in the optical axis direction, wherein a spring member configuring unit as a single unit is connected with the movable body first, the spring member configuring unit is divided into spring pieces to which a plurality of coil end portions pulled out from the coils are respectively connected, and the spring member is configured by a plurality of spring pieces. In this way, even when the spring member is configured by a plurality of spring pieces, the spring member configuring unit as a single unit simply needs to be connected to the movable body; therefore, there is no need to connect a plurality of spring pieces separately to the movable body. Accordingly, the efficiency in assembling a lens driving apparatus can be improved.

0021In at least an embodiment of the present invention, it is preferred that the spring member configuring unit be configured such that a plurality of spring pieces are joined together via constricted portions or thin portions. In this ways, the spring member configuring unit can be divided by an easy method of folding at the constricted portions or at the thin portions to configure a plurality of spring pieces.

0022In at least an embodiment of the present invention, the spring member is divided into a plurality of spring pieces at one place in the optical axis direction, through which current is supplied to the coils; thus, the coils can be supplied with current at only one location in the optical axis direction. Therefore, there is no need to supply current at two locations distanced in the optical axis direction, and also there is no need to pull around one terminal to the vicinity of the other terminal in the optical axis direction; thus, current can be easily supplied to the coils arranged to the movable body.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:

<figref idref="DRAWINGS">FIGS. 1</figref> (A), (B) and (C) are respectively an external appearance view of a lens driving apparatus to which the present invention may be applied, observing the front of the apparatus diagonally from the top, its perspective disassembly view and its side view.

<figref idref="DRAWINGS">FIGS. 2</figref> (A) and (B) are respectively cross-sectional views of the lens driving apparatus cut along the optical axis direction at the positions corresponding to the F-F′ line and the G-G′ line in <figref idref="DRAWINGS">FIG. 1</figref> (A).

<figref idref="DRAWINGS">FIGS. 3</figref> (A), (B) and (C) are respectively a plan view of the sleeve used in the lens driving apparatus of the present invention, its J-J′ cross-sectional view and its K-K′ cross-sectional view.

<figref idref="DRAWINGS">FIG. 4</figref> is a plan view of the case used in the lens driving apparatus to which the present invention is applied.

<figref idref="DRAWINGS">FIGS. 5</figref> (A) and (B) are respectively a plan view and a side view of the plate-like cover used in the lens driving apparatus to which the present invention is applied.

<figref idref="DRAWINGS">FIGS. 6</figref> (A) and (B) are respectively a perspective view of the first stopper mechanism configured in the lens driving apparatus to which the present invention is applied, and its plan view.

<figref idref="DRAWINGS">FIGS. 7</figref> (A) and (B) are respectively perspective views of the status of the lens driving apparatus of the present invention in which the first flat spring and the second flat spring are joined to the sleeve, observed from the photographic subject side and from the image pick-up side.

<figref idref="DRAWINGS">FIGS. 8</figref> (A) and (B) are respectively schematic diagrams showing the method of connecting the drive coils to the flat springs to which the present invention is applied.

<figref idref="DRAWINGS">FIG. 9</figref> is a plan view of the second flat spring used in the lens driving apparatus to which the present invention is applied.

<figref idref="DRAWINGS">FIGS. 10</figref> (A) and (B) are respectively plan views of the configurations of the first flat spring used in the lens driving apparatus of the present invention before and after the division.

<figref idref="DRAWINGS">FIGS. 11</figref> (A) and (B) are respectively enlarged diagrams showing the shape of the meander portion of the flat spring used in the lens driving apparatus to which the present invention is applied.

<figref idref="DRAWINGS">FIGS. 12</figref> (A), (B) and (C) are respectively configuration diagrams showing the shape of the arm portion of the flat spring used in the lens driving apparatus to which the present invention is applied.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

0036A lens driving apparatus to which the present invention may be applied is described hereinafter referring to the drawings. Note that the lens driving apparatus to be described hereinafter can be installed not only in camera phones, but also in various electronic apparatuses. For example, it can be used in thin digital cameras, PHSs, PDAs, barcode readers, surveillance cameras, cameras for checking behind vehicles, or doors having an optical verification function.

(Overall Configuration)

0037<figref idref="DRAWINGS">FIGS. 1</figref> (A), (B) and (C) are respectively an external appearance view of a lens driving apparatus to which the present invention may be applied, observing the front of the apparatus diagonally from the top, its perspective disassembly view and its side view. <figref idref="DRAWINGS">FIGS. 2</figref> (A) and (B) are respectively cross-sectional views of the lens driving apparatus, cut along the optical axis direction at the positions corresponding to the F-F′ line and G-G′ line in <figref idref="DRAWINGS">FIG. 1</figref> (A). Note that the illustrations of the lenses and lens base are omitted in <figref idref="DRAWINGS">FIG. 2</figref> (B).

0038Used in thin cameras such as digital cameras or camera phones, the lens driving apparatus <b>1</b> of this embodiment shown in <figref idref="DRAWINGS">FIGS. 1</figref> (A), (B) and (C) and <figref idref="DRAWINGS">FIGS. 2</figref> (A) and (B) moves three lenses <b>121</b>, <b>122</b>, <b>123</b> in both A direction (to the front) and B direction (to the back) along the optical axis, the A direction in which the lenses are moved toward a photographic subject (toward an object) and the B direction in which the lenses are moved in the opposite direction from the photographic subject (toward the image). It is in a rectangular parallelepiped shape. The lens driving apparatus <b>10</b> has a movable body <b>3</b> in which the three lenses <b>121</b>, <b>122</b>, <b>123</b> and a fixed aperture <b>124</b> are held on a cylindrical lens holder <b>12</b> as a single unit, a drive mechanism <b>5</b> that moves the movable body <b>3</b> along the lens optical axis, L, and a fixed body <b>2</b> in which the drive mechanism <b>5</b> and the movable body <b>3</b> are installed. Also, the movable body <b>3</b> is provided with a cylindrical sleeve <b>13</b> inside which the cylindrical lens holder <b>12</b> is fixed.

0039In this embodiment, the fixed body <b>2</b> is provided with a rectangular base <b>19</b> for holding an image pick-up device (not illustrated) on the image side, a rectangular case <b>11</b> positioned on the photographic subject side, and a plate-like cover <b>18</b> (cover portion) for covering the end of the case <b>11</b> on the photographic subject side; circular light-entrance windows <b>110</b> and <b>180</b> are respectively formed in the centers of the case <b>11</b> and the plate-like cover <b>18</b> for collecting the light reflected from the photographic subject into the lenses. The fixed body <b>2</b> is also provided with an angular barrel-shaped back yoke <b>16</b> sandwiched between the base <b>19</b> and the case <b>11</b>; the back yoke <b>16</b> together with magnets <b>17</b>, which will be described later, configure an interlinked magnetic field producing body <b>4</b> that produces an interlinked magnetic field to coils <b>141</b> and <b>142</b>.

0040The lens drive mechanism <b>5</b> is provided with polygonal barrel-shaped first drive coil <b>141</b> and second drive coil <b>142</b> arranged on the outer circumferential face of the sleeve <b>15</b> and also with the interlinked magnetic field producing body <b>4</b> that produces an interlinked magnetic field to the drive coils <b>141</b> and <b>142</b>; the drive coils <b>141</b> and <b>142</b> and the interlinked magnetic field producing body <b>4</b> together configure a magnetic drive mechanism <b>5</b><i>a</i>. The interlinked magnetic field producing body <b>4</b> is equipped with four magnets <b>17</b> arranged between the drive coils <b>141</b> and <b>142</b> and with the angular barrel-shaped back yoke <b>16</b> composed of a ferromagnetic plate such as steel plate; the four drive magnets <b>17</b> are respectively fixed in the four corner portions of the inner peripheral face of the back yoke <b>16</b>. Each of the four drive magnets <b>17</b> is magnetized to opposite poles on the inside face and on the outside face. For example, each of the four drive magnets <b>17</b> is magnetized to N pole on the inside face and to S pole on the outside face.

0041The back yoke <b>16</b> is sandwiched between the base <b>19</b> and the case <b>11</b>, and is exposed to and configures the side faces of the lens driving apparatus <b>1</b>.

0042The lens drive mechanism <b>5</b> is further equipped with a first flat spring <b>31</b> (spring member) sandwiched between the back yoke <b>16</b> and the base <b>19</b> and a second flat spring <b>32</b> (spring member) sandwiched between the back yoke <b>16</b> and the case <b>11</b>. Both the first flat spring <b>31</b> and the second flat spring <b>32</b> are formed of a metallic thin plate and the thickness thereof is the same, thus increasing productivity. Note that the thickness of the first flat spring <b>31</b> and the second flat spring <b>32</b> in the optical axis direction may be varied accordingly. Also, another configuration can be adopted wherein the first flat spring <b>31</b> and the second flat spring <b>32</b> are composed of different materials, but in the same thickness.

0043In this embodiment, the distance between the opposing faces of the drive coils <b>141</b> and <b>142</b> is larger than the dimension of the drive magnet <b>17</b> in the optical axis direction, L. Therefore, there is a gap between the drive magnets <b>17</b> and the first drive coil <b>141</b> and between the drive magnets <b>17</b> and the second drive coil <b>142</b> in the optical axis direction, L; within the gap, the movable body <b>3</b> is movable in the optical axis direction, L.

0044The back yoke <b>16</b> is formed such that the length thereof in the optical axis direction, L, is longer than the distance between the opposing faces of the drive coils <b>141</b> and <b>142</b>. Therefore, leakage of magnetic flux from the magnetic path configured between the drive magnets <b>17</b> and the first drive coil <b>141</b> and from the magnetic path configured between the drive magnets <b>17</b> and the second drive coil <b>142</b>, can be reduced so that linearity between the moving amount of the sleeve <b>15</b> and the current passing through the drive coils <b>141</b> and <b>142</b> can be improved. For this reason, the above mentioned effect of reducing the leakage of magnetic flux can be obtained in the back yoke <b>16</b> of this embodiment even when the yoke <b>16</b> is not shaped to cover the side faces and the bottom face or the top face of the drive coils <b>141</b> and <b>142</b>.

0045In the lens driving apparatus <b>10</b>, terminals <b>318</b><i>a </i>and <b>318</b><i>b </i>for the drive coils <b>141</b> and <b>142</b> are formed on one side face; the configuration of the terminals <b>318</b><i>a </i>and <b>318</b><i>b </i>will be described later together with the configuration of the first flat spring <b>31</b> and the second flat spring <b>32</b>.

(Detailed Configuration of Sleeve

15

)

0046<figref idref="DRAWINGS">FIGS. 3</figref> (A), (B) and (C) are respectively a plan view of the sleeve <b>15</b>, its J-J′ cross-sectional view and its K-K′ cross-sectional view. As shown <figref idref="DRAWINGS">FIG. 1</figref> (B), <figref idref="DRAWINGS">FIG. 2</figref> (A) and <figref idref="DRAWINGS">FIG. 3</figref> (B), the sleeve <b>15</b> is cylindrical and a larger diameter portion <b>150</b> is formed on the outer circumferential face of the sleeve <b>15</b> around the center in the optical axis direction, L. As shown in <figref idref="DRAWINGS">FIG. 2</figref> (B), <figref idref="DRAWINGS">FIGS. 3</figref> (B) and (C), at the end portion of the sleeve <b>15</b> on the image pick-up device side, a rectangular flange portion <b>156</b> is formed and corner portions are formed at four locations in the circumferential direction. Further, as shown in <figref idref="DRAWINGS">FIG. 2</figref> (B), <figref idref="DRAWINGS">FIGS. 3</figref> (A), (B) and (C), at the end portion of the sleeve <b>15</b> on the photographic subject side, a rectangular flange portion <b>157</b> is formed and corner portions <b>157</b><i>a</i>, <b>157</b><i>b</i>, <b>157</b><i>c </i>and <b>157</b><i>d </i>formed in a trapezoid shape project at the four locations in the circumferential direction.

0047In this embodiment, when the drive coils <b>141</b> and <b>142</b> are fixed to the sleeve <b>15</b>, as shown in <figref idref="DRAWINGS">FIGS. 2</figref> (A), (B) and <figref idref="DRAWINGS">FIGS. 3</figref> (A), (B) and (C), the second drive coil <b>142</b> wound around a square drive coil bobbin (not illustrated) is fixed to the outer peripheral face of the flange portion <b>157</b> such that the corner portions thereof are positioned outside the corner portions <b>157</b><i>a</i>, <b>157</b><i>b</i>, <b>157</b><i>c </i>and <b>157</b><i>d</i>. At that time, the end face of the second drive coil <b>142</b> on the image pick-up device side makes contact with the end face of the larger diameter portion <b>150</b> on the photographic subject side. Also, the first drive coil <b>141</b> wound around a square drive coil bobbin (not illustrated) is fixed to the outer peripheral face of the flange portion <b>156</b> such that the corner portions thereof are positioned outside the corner portions of the flange portion <b>156</b>. At that time, the end face of the first drive coil <b>141</b> on the photographic subject side makes contact with the end face of the larger diameter portion <b>150</b> on the image pick-up device side.

0048Of the corner portions <b>157</b><i>a</i>, <b>157</b><i>b</i>, <b>157</b><i>c </i>and <b>157</b><i>d </i>in the sleeve <b>15</b>, the corner portions <b>157</b><i>a </i>and <b>157</b><i>c </i>that project in a trapezoid shape on the diagonal line are respectively provided with thick portions <b>158</b><i>a </i>and <b>158</b><i>c </i>on the outer periphery thereof and magnetic piece retaining holes <b>159</b><i>a </i>and <b>159</b><i>c </i>which open to the photographic subject side are formed inside the thick portions <b>158</b><i>a </i>and <b>158</b><i>c</i>. In the magnetic piece retaining holes <b>159</b><i>a </i>and <b>159</b><i>c</i>, magnetic pieces <b>38</b> are retained which will be described later.

0049In the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>which project in a trapezoid shape on the other diagonal line of the sleeve <b>15</b>, thick portions <b>158</b><i>b </i>and <b>158</b><i>d </i>are formed projecting toward the photographic subject like columns even more than the end face of the sleeve <b>15</b> on the photographic subject side (the end face of the movable body <b>3</b> on the photographic subject side), and magnetic piece retaining holes <b>159</b><i>b </i>and <b>159</b><i>d </i>which open to the photographic subject side are formed inside the thick portions <b>158</b><i>b </i>and <b>158</b><i>d</i>. In the magnetic piece retaining holes <b>159</b><i>b </i>and <b>159</b><i>d</i>, magnetic pieces <b>138</b> are retained which will be described later.

0050In this embodiment, the drive coils <b>141</b> and <b>142</b> are supplied with current via the first flat spring <b>31</b> as described in detail later. More specifically, while the drive coil <b>141</b> is directly connected to the first flat spring <b>31</b>, the drive coil <b>142</b> is passed through a groove-like guide portion (see <figref idref="DRAWINGS">FIG. 3</figref> (A)) formed in the vicinity of the corner portion <b>157</b><i>a </i>of the sleeve <b>15</b> and connected to the first flat spring <b>31</b>. Therefore, there is no need to provide an additional space for pulling around the end portion of the coil. The drive coils <b>141</b> and <b>142</b> are connected to each other by the coil end portions thereof and the connection portion is stored in the groove-like guide portion <b>154</b> of the sleeve <b>15</b>.

(Configuration of Case

11

)

0051<figref idref="DRAWINGS">FIG. 4</figref> is a plan view of the case <b>11</b>. As shown in <figref idref="DRAWINGS">FIGS. 1</figref> (A) and (B) and <figref idref="DRAWINGS">FIG. 4</figref>, the case <b>11</b> is a rectangular flat plate, and a light-entrance window <b>110</b> is formed in the center thereof. In the case <b>11</b>, step portions <b>111</b><i>a </i>and <b>111</b><i>c </i>are formed along the light-entrance window <b>110</b> on one of the diagonal lines.

0052Also, in the case <b>11</b>, notches <b>112</b><i>b </i>and <b>112</b><i>d </i>are cut radially outward from the light-entrance window on the other diagonal line. The notches <b>112</b><i>b </i>and <b>112</b><i>d </i>are configured by recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>and shallow notches <b>114</b><i>b </i>and <b>114</b><i>d</i>; the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>being cut deep radially outward from the light-entrance window <b>110</b> in a trapezoid shape, and the shallow notches <b>114</b><i>b </i>and <b>114</b><i>d </i>extending in the circumferential direction from the recess portions <b>113</b><i>b </i>and <b>113</b><i>d</i>. The recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>are shaped in trapezoid in the same manner as the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>described referring to <figref idref="DRAWINGS">FIGS. 3</figref> (A) and (C); however, they are slightly larger than the corner portions <b>157</b><i>b </i>and <b>157</b><i>d. </i>

(Configuration of Plate-Like Cover

18

)

0053<figref idref="DRAWINGS">FIGS. 5</figref> (A) and (B) are respectively a plan view and a side view of the plate-like cover <b>18</b>. As shown in <figref idref="DRAWINGS">FIGS. 1</figref> (A) and (B), <figref idref="DRAWINGS">FIGS. 2</figref> (A) and (B) and <figref idref="DRAWINGS">FIGS. 5</figref> (A) and (B), the plate-like cover <b>18</b> is composed of a nonmagnetic thin plate (SUS304, for example) and provided with a rectangular ceiling portion <b>185</b> that covers the end of the case <b>11</b> on the photographic subject side and a pair of engaging leg portions <b>181</b> that extend from a pair of opposing sides of the ceiling portion <b>185</b>. A light-entrance window <b>180</b> is formed in the center of the ceiling portion <b>185</b> and notches <b>186</b> are cut in the positions superposing the step portions <b>111</b><i>a </i>and <b>111</b><i>c </i>of the case <b>11</b> which have been described referring to <figref idref="DRAWINGS">FIG. 4</figref>.

0054The engaging leg portions <b>181</b> have engaging through holes <b>181</b><i>a </i>formed near the bottom ends thereof. To engage with these leg portions, engaging protrusions <b>191</b> are formed in the side faces of the base <b>19</b> as shown in <figref idref="DRAWINGS">FIGS. 1</figref> (A) and (B). Therefore, having the base <b>19</b>, the flat spring <b>31</b>, the back yoke <b>16</b>, the flat spring <b>32</b> and the case <b>11</b> already layered, the plate-like cover <b>18</b> is layered on top of the case <b>11</b> on the photographic subject side and the engaging protrusions <b>191</b> of the base <b>19</b> are fitted into the engaging through holes <b>181</b><i>a</i>. In this way, the plate-like cover <b>18</b> is fixed to the base <b>19</b>.

(Configuration of Stopper Mechanism)

0055<figref idref="DRAWINGS">FIGS. 6</figref> (A) and (B) are respectively a perspective view of a first stopper mechanism in the lens driving apparatus to which the present invention is applied, and its plan view. When the lens driving apparatus <b>10</b> is assembled, as shown in <figref idref="DRAWINGS">FIGS. 6</figref> (A) and (B), the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>of the sleeve <b>15</b> (movable body <b>3</b>) in a plane trapezoid shape settle into the inside of the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>of the case <b>11</b> in a plane trapezoid shape. Under this condition, the outer peripheral faces of the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>of the sleeve <b>15</b> are opposed to the inner peripheral faces of the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>of the case <b>11</b> via a gap, x, on the inner side in the radial direction. Also, the outer peripheral faces of the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>are opposed to the inner peripheral faces of the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>via a gap, y, in the circumferential direction. In this manner, a stopper mechanism <b>101</b> is configured for regulating the displacement of the movable body <b>3</b> in the direction (radial direction or circumferential direction) perpendicular to the optical axis direction, L.

(Operation)

0056In the lens driving apparatus <b>10</b> of this embodiment, the movable body <b>3</b> is normally positioned on the image pick-up device side as shown in <figref idref="DRAWINGS">FIG. 2</figref> (A) or <figref idref="DRAWINGS">FIG. 2</figref> (B). More specifically, the bottom end face (the face on the image side) of the sleeve <b>15</b> is in contact with the top face (the face on the front side) of the base <b>19</b>.

0057Under such a condition, when current is passed through the drive coils <b>141</b> and <b>142</b> in a predetermined direction, both coils receive an upward electromagnetic force (toward the front). By this force, the sleeve <b>15</b> around which the drive coils <b>141</b> and <b>142</b> are firmly fixed starts moving toward the photographic subject (toward the front). At that time, resilient force that regulates the movement of the sleeve <b>15</b> is respectively applied between the flat spring <b>31</b> and the front end of the sleeve <b>15</b> and between the flat spring <b>32</b> and the rear end of the sleeve <b>15</b>. For this reason, the sleeve <b>15</b> is halted when the electromagnetic force to move the sleeve <b>15</b> to the front attains equilibrium with the resilient force that regulates the movement of the sleeve <b>15</b>. Also, when current is passed through the drive coils <b>141</b> and <b>142</b> in the opposite direction, the drive coils <b>141</b> and <b>142</b> receive a downward electromagnetic force (toward the back).

0058At that time, by adjusting the current passing through the drive coils <b>141</b> and <b>142</b> and adjusting the resilient force of the flat springs <b>31</b> and <b>32</b> exerted on the sleeve <b>15</b>, the sleeve <b>15</b> (movable body <b>3</b>) can be halted in a desired position. Since the urging force of the magnetic pieces <b>138</b> and the drive magnets <b>17</b> held by the movable body <b>3</b> is also used, the magnetic drive mechanism <b>5</b><i>a </i>for producing a thrust force in the optical axis direction, L, to the movable body <b>3</b> can be downsized.

0059Also, the flat springs <b>31</b> and <b>32</b> in this embodiment have a linear relationship established between the resilient force (stress) and the displacement; therefore, linearity between the moving amount of the sleeve <b>15</b> and the current passing through the drive coils <b>141</b> and <b>142</b> can be improved. Also, when the two flat springs <b>31</b> and <b>32</b> which are resilient members are used, a large force in equilibrium is applied in the optical axis direction, L, when the sleeve <b>15</b> is halted; therefore, even when the centrifugal force or another force such as a force of impact is exerted in the optical axis direction, L, the sleeve <b>15</b> can be halted with more stability. Further, in the lens driving apparatus <b>10</b>, the sleeve <b>15</b> is halted not by colliding with a colliding material (a buffer material) but by utilizing equilibrium between the electromagnetic force and the resilient force; therefore, colliding noise can be prevented.

0060Further, in this embodiment, the movable body <b>3</b> is supported by the fixed body <b>2</b> via the flat springs <b>31</b> and <b>32</b>, and the stopper mechanism <b>101</b> is configured between the movable body <b>2</b> and the fixed body <b>2</b> (case <b>11</b>) for regulating the displacement of the movable body <b>3</b> in the direction (radial direction or circumferential direction) perpendicular to the optical axis direction, L, caused when a shock is applied; therefore, the movable body <b>3</b> is not displaced greatly even when a shock is applied to the movable body <b>3</b> in the direction perpendicular to the optical axis direction. Therefore, since the flat springs <b>31</b> and <b>32</b> will not be deformed into unrecoverable shape, they function normally even after a shock is applied. Even when the movable body <b>2</b> receives a shock in the direction perpendicular to the optical axis direction, L, the movable body <b>3</b> will not be displaced greatly, thus preventing the problems of the drive coils <b>141</b> and <b>142</b> colliding with other members to cut wires or short circuits. In the lens driving apparatus <b>10</b> according to the present invention, shock resistance in the direction perpendicular to the optical axis direction, L, can be improved.

0061The stopper mechanism <b>101</b> is configured by the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>(protrusions) that project from the movable body <b>3</b> in the radial direction and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>inside which the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>are positioned; thus, the stopper mechanism <b>101</b> can be constructed by a relatively simple configuration. Also, since the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>are in a trapezoid (polygonal) shape, even when a shock is applied to the movable body <b>3</b> in the direction perpendicular to the optical axis direction, L, the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>interfere with each other in a relatively wide area, ensuring the operation and preventing any damage to the stopper mechanism <b>101</b>.

0062Further, the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>are formed to the movable body <b>3</b> while the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>are formed to the fixed body <b>2</b> (case <b>11</b>); therefore, the thickness of the movable body <b>2</b> can be reduced. In other words, when the recess portions are formed to the movable body <b>3</b>, there is a restriction in designing to form the outer peripheral wall of the movable body <b>3</b> to be thick. However, since the protrusions (the corner portions <b>157</b><i>b </i>and <b>157</b><i>d</i>) are formed to the movable body <b>3</b>, there is no restriction in designing.

0063Furthermore, the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>are provided with the thick portions <b>158</b><i>b </i>and <b>158</b><i>d </i>that project like columns from the end face of the movable body <b>3</b> on the photographic subject side toward the photographic subject, and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>are formed to the case <b>11</b>; therefore, longer dimensions in the optical axis direction, L can be obtained for the protrusions (the corner portions <b>157</b><i>b </i>and <b>157</b><i>d</i>) and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d</i>. For this reason, even under the condition where the movable body <b>3</b> is in a position shifted to either side in the optical axis direction, L, when a shock is applied to the movable body <b>3</b> in the direction perpendicular to the optical axis direction, L, the protrusions (the corner portions <b>157</b><i>b </i>and <b>157</b><i>d</i>) and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>will interfere with each other with certainty to regulate the displacement of the movable body <b>3</b>.

0064Although the stopper mechanism <b>101</b> (the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d</i>) is exposed to the face of the case <b>11</b> on the photographic subject side, since it is covered with the plate-like cover <b>18</b>, the appearance of the lens driving apparatus <b>10</b> can be improved. Also, the plate-like cover <b>18</b> prevents foreign matter from entering the lens driving apparatus <b>10</b>.

0065Provided to the movable body <b>3</b> are the magnetic piece retaining holes <b>159</b><i>a</i>, <b>159</b><i>b</i>, <b>159</b><i>c </i>and <b>159</b><i>d </i>for retaining the magnetic pieces <b>138</b> that apply the urging force to the movable body <b>3</b> in the optical axis direction, L, by using the attraction force produced with the drive magnets <b>17</b>. While the magnetic piece retaining holes <b>159</b><i>a </i>and <b>159</b><i>c </i>are covered by the case <b>11</b>, the other holes <b>159</b><i>b </i>and <b>159</b><i>d </i>are exposed to the face of the base <b>11</b> on the photographic subject side. Therefore, the magnetic piece retaining holes <b>159</b><i>b </i>and <b>159</b><i>d </i>can be used as the urging force-adjusting magnetic piece retaining portions through which the number and size of the magnetic pieces <b>138</b> can be changed even after the case <b>11</b> is covered. Even in this case, the magnetic piece retaining holes <b>159</b><i>b </i>and <b>159</b><i>d </i>(the urging force-adjusting magnetic piece retaining portions) are formed in the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>configuring the stopper mechanism <b>101</b> and covered by the plate-like cover <b>18</b>; thus, foreign matter is prevented from entering the lens driving apparatus <b>10</b>.

0066Since the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>(the protrusions) projecting from the movable body <b>3</b> in the radial direction are settled inside the recess portions <b>113</b><i>b </i>and <b>113</b><i>d</i>, the effective length can be obtained for the corner portions <b>157</b><i>b </i>and <b>157</b><i>d</i>, by which the lens driving apparatus <b>10</b> can be thinner.

0067Note that, although the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>and the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>are respectively formed in a trapezoid (polygonal) shape, they may be formed in a half-circular shape. Also, the bottom ends of the corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>may be extended outward in the radial direction and these extended portions be slid to the edges of the recess portions <b>113</b><i>b </i>and <b>113</b><i>d </i>of the case <b>11</b>. In this way, the extended portions and the edge of the case <b>11</b> are layered in the optical axis direction, L, and opposed to each other via a predetermined gap in the optical axis direction, L. Therefore, the stopper mechanism can be configured for regulating the moving range of the movable body <b>3</b> toward the photographic subject when a shock is applied to the movable body <b>3</b> in the optical axis direction, L. For this reason, the displacement of the movable body <b>3</b> in the optical axis direction, L, can be prevented before the flat springs <b>31</b> and <b>32</b> are excessively deformed; therefore, the flat springs <b>31</b> and <b>32</b> can function normally even after the shock is applied. Even when a shock is applied to the movable body <b>3</b> in the optical axis direction, L, the movable body <b>3</b> will not be displaced excessively; therefore, even in the case that the drive coils <b>141</b> and <b>142</b> and the drive magnets <b>17</b> are opposed to each other in the optical axis direction, L, problems such as cut wires or short circuits that may be caused by the collision between the drive coils <b>141</b> and <b>142</b> and drive magnets <b>17</b> will be prevented. Accordingly, shock resistance in the optical axis direction, L, can be improved in the lens driving apparatus <b>10</b>.

(Configuration of Current Supply to Drive Coils

141

and

142

)

0068<figref idref="DRAWINGS">FIGS. 7</figref> (A) and (B) are respectively perspective views of the sleeve <b>15</b> with which the flat springs <b>31</b> and <b>32</b> are joined, observed from the photographic subject side and from the image pick-up device side. <figref idref="DRAWINGS">FIGS. 8</figref> (A) and (B) are respectively schematic diagrams showing methods of joining the drive coils to the flat springs to which the present invention is applied.

0069As shown in <figref idref="DRAWINGS">FIGS. 7</figref> (A) and (B), in the lens driving apparatus <b>10</b> of this embodiment, the first flat spring <b>31</b> and the second flat spring <b>32</b> are joined to the top and bottom ends of the sleeve <b>15</b> (movable body <b>3</b>). Each of the flat springs <b>31</b> and <b>32</b> supports the movable body <b>3</b> to move in the optical axis direction and functions to prevent the rotation of the movable body <b>3</b> about the optical axis.

0070While the first flat spring <b>31</b> and the second flat spring <b>32</b> are formed in the same shape, they are arranged at the angle positions mutually shifted by 90°.

0071In this embodiment, the second flat spring <b>32</b> is formed as a single piece. On the other hand, the first flat spring <b>31</b> is configured by two spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>which are electrically divided; the terminals <b>318</b><i>a </i>and <b>318</b><i>b </i>are respectively formed to the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>. Therefore, as shown in <figref idref="DRAWINGS">FIGS. 8</figref> (A) and (B), the coil ends of the drive coils <b>141</b> and <b>142</b> are electrically connected to the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>so that current can be supplied to the drive coils <b>141</b> and <b>142</b> via the terminals <b>318</b><i>a </i>and <b>318</b><i>b. </i>

0072More specifically described, as shown in <figref idref="DRAWINGS">FIG. 8</figref> (A), for example, the beginning winding (coil end portion) <b>141</b><i>a </i>pulled out from the inner periphery of the drive coil <b>141</b> is soldered to the coil connecting portion <b>317</b><i>a </i>formed to the spring piece <b>31</b><i>a</i>, and the ending winding (coil end portion) <b>142</b><i>b </i>pulled out from the outer periphery of the drive coil <b>142</b> is soldered to the coil connecting portion <b>317</b><i>b </i>formed to the spring piece <b>31</b><i>b</i>. Also, the ending winding (coil end portion) <b>141</b><i>b </i>pulled out from the outer periphery of the drive coil <b>141</b> is connected with the beginning winding (coil end portion) <b>142</b><i>a </i>pulled out from the inner periphery of the drive coil <b>142</b>. At that time, the ending winding (coil end portion) <b>142</b><i>b </i>of the drive coil <b>142</b> is passed through the groove-like guide portion <b>154</b> cut near the corner portion <b>157</b><i>a </i>of the sleeve <b>15</b> shown in <figref idref="DRAWINGS">FIGS. 3</figref> (A) and guided to the spring piece <b>31</b><i>b</i>, and the connection portion <b>140</b> between the ending winding (coil end portion) <b>141</b><i>b </i>of the drive coil <b>141</b> and the beginning winding (coil end portion) <b>142</b><i>a </i>of the drive coil <b>142</b> is also stored in the groove-like guide portion <b>154</b>. In this way, the drive coils <b>141</b> and <b>142</b> are connected in series and the winding directions of the drive coils <b>141</b> and <b>142</b> are unified.

0073As shown in <figref idref="DRAWINGS">FIG. 8</figref> (B), while the ending winding (coil end portion) <b>141</b><i>b </i>pulled out from the outer periphery of the drive coil <b>141</b> may be soldered to the coil connecting portion <b>137</b><i>a </i>formed to the spring piece <b>31</b><i>a</i>, the ending winding (coil end portion) <b>142</b><i>b </i>pulled out from the outer periphery of the drive coil <b>142</b> may be soldered to the coil connecting portion <b>317</b><i>b </i>formed to the spring piece <b>31</b><i>b</i>. In this case, the beginning winding (coil end portion) <b>141</b><i>a </i>pulled out from the inner periphery of the drive coil <b>141</b> is connected with the beginning winding (coil end portion) <b>142</b><i>a </i>pulled out from the inner periphery of the drive coil <b>142</b>. Even in this case, the ending winding (coil end portion) <b>142</b><i>b </i>of the drive coil <b>142</b> is passed through the groove-like guide portion <b>154</b> formed near the corner portion <b>157</b><i>a </i>of the sleeve <b>15</b> shown in <figref idref="DRAWINGS">FIGS. 3(A)</figref> and guided to the spring piece <b>31</b><i>b</i>, and the connection portion <b>140</b> between the beginning winding (coil end portion) <b>141</b><i>a </i>of the drive coil <b>141</b> and the beginning winding (coil end portion) <b>142</b><i>a </i>of the drive coil <b>142</b> is also stored in the groove-like guide portion <b>154</b>. In this way, the drive coils <b>141</b> and <b>142</b> are connected in series, but the winding directions of the drive coils <b>141</b> and <b>142</b> are opposite from each other.

0074Note that, when one of the coil end portions pulled out from the drive coils <b>141</b> and <b>142</b>, which is pulled out at the position away from the first flat spring <b>31</b>, is pulled around to the spring piece <b>31</b><i>b</i>, it may pass through the opening formed in the second flat spring <b>32</b>.

(Detailed Configuration of Second Flat Spring

32

)

0075<figref idref="DRAWINGS">FIG. 9</figref> is a plan view of the second flat spring <b>32</b> used in the lens driving apparatus to which the present invention is applied. As shown in <figref idref="DRAWINGS">FIG. 9</figref>, the second flat spring <b>32</b> is provided with a rectangular outside frame portion <b>321</b> held by the fixed body <b>2</b> being sandwiched between the back yoke <b>16</b> and the case <b>11</b>, an annular inside frame portion <b>322</b> joined to the top end of the sleeve <b>15</b>, and two arm portions <b>323</b> for connecting the inside frame portion <b>322</b> and the outside frame portion <b>321</b>. The two arm portions <b>323</b> are configured by point symmetry about the center C<b>2</b> (optical axis) of the inside frame portion <b>322</b>; each arm portion <b>323</b> extends in the area (hereinafter corner portion <b>325</b>) corresponding to the corner portion of the outside frame portion <b>321</b> between the inside frame portion <b>322</b> and the outside frame portion <b>321</b>, meandering in a plurality of curve portions <b>323</b><i>e </i>with respect to the direction of a plane perpendicular to the optical axis direction, L. The two arm portions <b>323</b> are configured such that the portions thereof joining with the outside frame portion <b>321</b> (outside frame joining portions <b>323</b><i>a</i>) are positioned on the sides of the outside frame portion <b>321</b> by point symmetry about the center C<b>2</b> of the inside frame portion <b>322</b>. Also, the two arm portions <b>323</b> respectively extend parallel to the side portions of the outside frame portion <b>321</b> to which they are joined, crossing over an imaginary bisector, L<b>2</b>, that passes through the center C<b>2</b> (optical axis) of the inside frame portion <b>322</b>, and then are joined to the inside frame portion <b>322</b>.

0076In the two arm portions <b>323</b>, the portions thereof joining with the inside frame portion <b>322</b> (inside frame joining portion <b>323</b><i>b</i>) are parallel to the bisector, L<b>2</b>, and are shifted from the bisector, L<b>2</b> (preferably the inside frame joining portions <b>323</b><i>b </i>are respectively shifted to the opposite directions from the bisector, L<b>2</b>). Further, the extension lines of the inside frame joining portions <b>323</b><i>b </i>of the two arm portions <b>323</b> are displaced from the center, C<b>2</b>, of the inside frame portion <b>322</b>. The arm portion <b>323</b> varies its width in the longitudinal direction, being wider near the outside frame joining portion <b>323</b><i>a </i>and at the inside frame joining portion <b>323</b><i>b. </i>

0077In each of the four corner portions of the outside frame portion <b>321</b> of the second flat spring <b>32</b>, a hole <b>324</b> is formed into which the protrusion portion <b>16</b><i>a </i>of the back yoke <b>16</b> shown in <figref idref="DRAWINGS">FIG. 2</figref> (B) is fitted. Also, in the inside frame portion <b>322</b> of the second flat spring <b>32</b>, notches <b>326</b> are cut into which small protrusions <b>152</b> of the sleeve <b>15</b> shown in <figref idref="DRAWINGS">FIG. 7</figref> (A) are fitted.

(Detailed Configuration of First Flat Spring

31

)

0078<figref idref="DRAWINGS">FIGS. 10</figref> (A) and (B) are plan views of the first flat spring <b>31</b> used in the lens driving apparatus to which the present invention is applied, showing the configuration before and after the division. As shown in <figref idref="DRAWINGS">FIG. 10</figref> (B), the first flat spring <b>31</b> is divided into two spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>which are electrically insulated; when the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>are combined together, it is in the same shape as the second flat spring <b>32</b>. More specifically described, the first flat spring <b>31</b> is provided with a rectangle outside frame portion <b>311</b> held by the fixed body <b>2</b> being sandwiched between the back yoke <b>16</b> and the base <b>19</b>, an annular inside frame portion <b>312</b> joined to the bottom end of the sleeve <b>15</b>, and two arm portions <b>313</b> for connecting the inside frame portion <b>312</b> and the outside frame portion <b>311</b>. The two arm portions <b>313</b> are configured by point symmetry about the center, C<b>1</b>, (optical axis) of the inside frame portion <b>312</b>; each of the arm portions <b>313</b> extends in the area (hereinafter corner portion <b>315</b>) corresponding to the corner portion of the outside frame portion <b>311</b> created between the inside frame portion <b>312</b> and the outside frame portion <b>311</b>, meandering in a plurality of curve portions <b>313</b><i>e </i>with respect to the direction of a plane perpendicular to the optical axis direction, L. The two arm portions <b>313</b> are configured such that the portions thereof joining with the outside frame portion <b>311</b> (outside frame joining portions <b>313</b><i>a</i>) are positioned on the sides of the outside frame portion <b>311</b> by point symmetry about the center, C<b>1</b>, of the inside frame portion <b>312</b>. Also, each of the two arm portions <b>313</b> respectively extend parallel to the side portions of the outside frame portion <b>311</b>, to which they are joined, crossing over an imaginary bisector, L<b>1</b>, that passes through the center, C<b>1</b>, (optical axis) of the inside frame portion <b>312</b>, and then are joined to the inside frame portion <b>312</b>.

0079In the two arm portions <b>313</b>, the portions thereof joining with the inside frame portion <b>312</b> (inside frame joining portion <b>313</b><i>b</i>) are positioned on both sides of a bisector, L<b>1</b>, and extend parallel to the sides of the outside frame portion <b>311</b>, that is, parallel to the bisector, L<b>1</b>; the extension lines of the inside frame joining portions <b>313</b><i>b </i>of the two arm portions <b>313</b> are displaced from the center, C<b>1</b>, of the inside frame portion <b>312</b>. The arm portion <b>313</b> varies its width in the longitudinal direction, being wider near the outside frame joining portion <b>313</b><i>a </i>and at the inside frame joining portion <b>313</b><i>b. </i>

0080In the inside frame portion <b>312</b> of the first flat spring <b>31</b>, small holes <b>316</b> are formed to which the small protrusions <b>151</b> of the sleeve <b>15</b> shown in <figref idref="DRAWINGS">FIG. 7</figref> (B) are fitted. Also, in the first flat spring <b>31</b>, coil connection portions <b>317</b><i>a </i>and <b>317</b><i>b </i>are formed in the inside frame portions <b>312</b> of the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>, projecting toward the outer periphery, and are connected by soldering to the coil ends shown in <figref idref="DRAWINGS">FIGS. 8</figref> (A) and (B). Further, in the first flat spring <b>31</b>, terminals <b>318</b><i>a </i>and <b>318</b><i>b </i>are respectively formed at the outside frame portions <b>311</b> of the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>, being bent at right angle at the outer periphery.

0081The first flat spring <b>31</b> configured as above is assembled in the lens driving apparatus <b>10</b> as a flat spring-configuring member <b>310</b> in which the spring pieces <b>31</b><i>a </i>and <b>32</b><i>b </i>are formed in a lead frame as a single unit. In the flat spring-configuring member <b>310</b>, the ends of the terminals <b>318</b><i>a </i>and <b>318</b><i>b </i>are joined to a substantially U-shaped connection portion <b>310</b><i>a </i>via constricted portions <b>138</b><i>c</i>. Therefore, by simply folding [the connection portion <b>310</b><i>a</i>] at the constricted portions <b>318</b><i>c</i>, the connection portion <b>310</b><i>a </i>can be cut. Also, on the other side of the first flat spring member from the terminals <b>318</b><i>a </i>and <b>318</b><i>b</i>, the outside frame portion <b>311</b> is joined to the substantially U-shaped connection portion <b>310</b><i>b </i>via constricted portions <b>311</b><i>c</i>. Therefore, by simply folding [the connection portion <b>310</b><i>b</i>] at the constricted portions <b>311</b><i>c</i>, the connection portion <b>310</b><i>b </i>can be cut. Further, the ends of the inside frame portions <b>312</b> are respectively joined via constricted portions <b>312</b><i>c </i>with two pieces of connection portions <b>310</b><i>c </i>that extend inward in the radial direction. One end of each of the two pieces of connection portions <b>310</b><i>c </i>is divided by a slit; by simply folding the pieces of connection portions <b>310</b><i>c </i>individually at the constricted portions <b>312</b><i>c</i>, the connection portions <b>310</b><i>c </i>can be detached. For this reason, the end portions of the spring pieces <b>31</b><i>a </i>and <b>32</b><i>b </i>have a cutting [trace].

(Assembly Method)

0082The lens driving apparatus <b>10</b> using the above members is assembled in the following process. The movable body <b>3</b> is first positioned inside the back yoke <b>16</b>, and the back yoke <b>16</b> and the base <b>19</b> are fixed by an adhesive, sandwiching the flat spring member configuring unit <b>310</b> (first flat spring <b>31</b>) and an insulation material (not illustrated) between them. Next, the connection portions <b>310</b><i>a</i>, <b>310</b><i>b </i>and <b>310</b><i>c </i>are respectively folded at the constricted portions <b>311</b><i>c</i>, <b>312</b><i>c </i>and <b>318</b><i>c </i>of the flat spring member configuring unit <b>310</b> to detach them. In this manner, the first flat spring <b>31</b> is divided into two pieces of spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>. Then, the terminals <b>318</b><i>a </i>and <b>318</b><i>b </i>are bent downward.

0083Next, the coil ends of the drive coils <b>141</b> and <b>142</b> are soldered to the coil connection portions <b>317</b><i>a </i>and <b>317</b><i>b </i>formed to the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>. Note that the process of soldering the coil ends of the drive coils <b>141</b> and <b>142</b> to the coil connection portions <b>317</b><i>a </i>and <b>317</b><i>b </i>may be performed before the flat spring member configuring unit <b>310</b> is divided into the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b. </i>

0084For such an assembly process, in the movable body <b>3</b> (sleeve <b>15</b>), the ball-type, wire-type or bar-type magnetic piece <b>138</b> is attached to each of the magnetic piece retaining holes <b>159</b><i>a</i>, <b>159</b><i>b</i>, <b>159</b><i>c </i>and <b>159</b><i>d</i>, which open to the photographic subject side, and fixed by an adhesive.

0085Next, the back yoke <b>16</b> and the case <b>11</b> are fixed by an adhesive, sandwiching the second flat spring <b>32</b> and an insulation material (not illustrated) between them. At that time, the corner portions <b>157</b><i>a </i>and <b>157</b><i>c </i>including the magnetic piece retaining holes <b>159</b><i>a </i>and <b>159</b><i>c </i>are entirely covered by the case <b>11</b>. On the other hand, the magnetic piece retaining holes <b>159</b><i>b </i>and <b>159</b><i>d </i>are exposed with the faces thereof on the photographic subject side through the notch portions of the flat spring <b>32</b> and the notches <b>112</b><i>b </i>and <b>112</b><i>d </i>of the case <b>11</b>.

0086Under this condition, the drive coils <b>141</b> and <b>142</b> are electrified to drive the movable body <b>3</b>, and then the inclination of the movable body <b>3</b> and the current value (start current) required to start the movable body <b>3</b> are corrected. In other words, if there is a problem in the inclination of the movable body <b>3</b>, an additional ball-type, wire-type, or bar-type magnetic piece <b>138</b> is attached to either one or both of the magnetic piece retaining holes <b>159</b><i>b </i>and <b>159</b><i>d </i>or the magnetic piece <b>138</b> is replaced with one in a different size to correct the inclination of the movable body <b>3</b>. Also, by placing the additional magnetic piece <b>138</b> or replacing the magnetic piece <b>138</b> with one in a different size, the current value (starting current) required to start the movable body <b>3</b> can be adjusted. Without such a configuration, the magnetic pieces <b>138</b> once installed in the lens driving apparatus <b>10</b> cannot be replaced with another; when the urging force of the magnetic pieces <b>138</b> applied to the moving body <b>3</b> is not suitable, waste of process can be prevented. However, according to this embodiment, even after the inspection of the apparatus near the completion of the assembly, the magnetic pieces <b>138</b> can be easily changed; therefore, there will be no waste of process.

0087Next, the plate-like cover <b>18</b> is layered on the end of the case <b>11</b> on the photographic subject side, and the engaging protrusions <b>191</b> of the base <b>19</b> are fitted into the engaging through holes <b>181</b><i>a </i>to fix the plate-like cover <b>18</b> to the base <b>19</b>. Under this condition, the entire corner portions <b>157</b><i>b </i>and <b>157</b><i>d </i>of the sleeve <b>15</b> including the magnetic piece retaining holes <b>159</b><i>b </i>and <b>159</b><i>d </i>and also the entire notches <b>112</b><i>b </i>and <b>112</b><i>d </i>of the case <b>11</b> are covered by the plate-like cover <b>18</b>.

0088<figref idref="DRAWINGS">FIGS. 11</figref> (A) and (B) are respectively the enlargements of the examples of the shape of the meander portion of the flat spring used in the lens driving apparatus of the present invention. As shown in <figref idref="DRAWINGS">FIGS. 11</figref> (A) and (B), the meander portion of the flat spring <b>31</b>, <b>32</b> formed with a plurality of curve portions <b>313</b><i>e</i>, <b>323</b><i>e </i>can be formed in any shape within the scope of the present invention. For example, as shown in <figref idref="DRAWINGS">FIG. 11</figref> (A), the meander portion can be shaped by stretching the meandering line; as shown in <figref idref="DRAWINGS">FIG. 11</figref> (B), it can be shaped with more turns.

0089<figref idref="DRAWINGS">FIGS. 12</figref> (A), (B) and (C) are respectively configuration diagrams showing the examples of the shape of the arm portions of the flat spring in the present invention. As shown in <figref idref="DRAWINGS">FIGS. 12</figref> (A), (B) and (C), in the flat spring <b>32</b>, the two arm portions <b>323</b> can be formed in any shape within the scope of the present invention. For example, in the above-mentioned embodiment, the meander portion is formed closer to the outside frame joining portion <b>323</b><i>a</i>; however, as shown in <figref idref="DRAWINGS">FIG. 12</figref> (A), the meander portion may be formed closer to the inside frame joining portion <b>323</b><i>b</i>. Also, as shown in <figref idref="DRAWINGS">FIG. 12</figref> (B), one of the extension lines of the inside frame joining portions <b>323</b><i>b </i>may pass through the center position, C, of the inside frame portion <b>322</b> while the other extension line extends away from the center position, C. Further, as shown in <figref idref="DRAWINGS">FIG. 12</figref> (C), if the extension lines of the inside frame joining portions <b>323</b><i>b </i>extend parallel to each other on both sides of the center position, C, of the inside frame portion <b>322</b>, one of the extension lines of the outside frame joining portion <b>323</b><i>a </i>may be parallel to the extension lines of the inside frame joining portion <b>323</b><i>b </i>and the other may intersect with the extension lines of the inside frame joining portion at any angle but 90 degrees. Although the illustration is omitted, both extension lines of the outside frame joining portion <b>323</b><i>a </i>may be parallel to the extension lines of the inside frame joining portion <b>323</b><i>b </i>or may intersect with the extension lines of the inside frame joining portion <b>323</b><i>b </i>at any angle but 90 degrees. Note that the configurations described referring to <figref idref="DRAWINGS">FIGS. 12</figref> (A), (B) and (C) can be applied to the arm portion <b>313</b> of the flat spring <b>31</b>.

(Effects of Shock Resistance)

0090As described in this embodiment, even when the rectangular flat springs <b>31</b> and <b>32</b> are used in accordance with the external shape of the lens driving apparatus <b>10</b> or the shape of the lens driving apparatus <b>5</b>, wider space assigned to the corner portions <b>315</b> and <b>325</b> in the outside frame portions <b>311</b> and <b>321</b> created in the area sandwiched between the rectangular outside frame portion <b>311</b> and the annular inside frame portions <b>312</b> and <b>322</b>, is efficiently used to extend the arm portions <b>313</b> and <b>323</b>. For this reason, a sufficient spring property can be given to the arm portions <b>313</b> and <b>323</b>, and the arm portions <b>313</b> and <b>323</b> can be constructed in such way that plastic deformation and breaking are not easily caused when the movable body <b>3</b> is moved abruptly in the direction perpendicular to the optical axis direction, L, or in the tilt direction. In other words, the arm portions <b>313</b> and <b>323</b> are shaped to have a plurality of curve portions <b>313</b><i>e </i>and <b>323</b><i>e </i>in wider space corresponding to the corner portions <b>315</b> and <b>325</b> of the outside frame portion <b>311</b> created in the area sandwiched between the outside frame portions <b>311</b> and <b>321</b> and the inside frame portions <b>312</b> and <b>322</b>. Therefore, even when the flat springs <b>31</b> and <b>32</b> are deformed by external force, since the stress applied to the meander portions is decentralized, the strength of the flat springs <b>31</b> and <b>32</b> remains. Accordingly, even when a vibration or shock in the direction perpendicular to the optical axis direction of the movable body <b>3</b> or in the tilt direction is applied to the apparatus having the configuration that the flat springs <b>31</b> and <b>32</b> have the rectangular outside frame portions <b>311</b> and <b>321</b>, the flat springs <b>31</b> and <b>32</b> will not have plastic deformation or breaking. Therefore, the lens driving apparatus <b>10</b> can be configured to be excellent in resisting vibrations and shocks in the direction perpendicular to the optical axis direction and in the tilt direction and also excellent in resisting the twist (distortion?) of the movable body <b>3</b>.

0091Also, the inside frame joining portions <b>313</b><i>b </i>and <b>323</b><i>b </i>which are joined to the inside frame portion <b>312</b> and <b>322</b> in the two arm portions <b>313</b> and <b>323</b> are configured such that the extension lines thereof extend parallel to each other in both areas sandwiching the center position, C, of the inside frame portions <b>312</b> and <b>322</b>. Therefore, since the locations at which the arm portions <b>313</b> and <b>323</b> give the spring property to the movable body <b>3</b> can be decentralized in a plane perpendicular to the optical axis direction, L, vibrations of the movable body <b>3</b> in the tilt direction can be efficiently reduced. From such a viewpoint, the extension lines of the inside frame joining portion <b>313</b><i>b </i>and <b>323</b><i>b </i>may intersect with each other at the position avoiding the center positions, C<b>1</b> and C<b>2</b>, of the inside frame portions <b>312</b> and <b>322</b>.

0092Further, the two arm portions <b>313</b> and <b>323</b> respectively extend crossing imaginary bisectors, L<b>1</b> and L<b>2</b>, which pass through the centers of the inside frame portions <b>312</b> and <b>322</b>, and the arm portions <b>313</b> and <b>323</b> are formed long; therefore, even when there is a restriction such as a narrow space between the sides of the outside frame portions <b>311</b> and <b>321</b> and the inside frame portions <b>312</b> and <b>322</b>, the spring property can be enhanced.

0093The two flat springs <b>31</b> and <b>32</b> are formed in the same shape, but arranged so that the angle position is shifted by 90°; therefore, the movable body <b>3</b> can be supported by the spring property in all directions. For this reason, problems such as poor vibration resistance and shock resistance in a particular direction can be avoided. Considering the fact that the movable body <b>3</b> is supported by the spring property in all directions, the shift of angle positions of the two flat springs <b>31</b> and <b>32</b> is not limited to 90° depending on the number and shape of the arm portions <b>313</b> and <b>323</b>.

0094Also, the arm portions <b>313</b> and <b>323</b> are formed wider near the outside frame joining portion <b>313</b><i>a </i>and at the inside frame joining portion <b>313</b><i>b</i>, thus varying the width thereof in the longitudinal direction; therefore, problems will be avoided in that the movable body <b>3</b> is resonated and displaced greatly and stress is concentrated on specific locations of the arm portions <b>313</b> and <b>323</b>. From the above viewpoint, the thickness of the arm portions <b>313</b> and <b>323</b> may be changed in the longitudinal direction.

Major Effects of this Embodiment

0095As described above, in this embodiment, the first flat spring <b>31</b> is divided at one place in the optical axis direction, L, into a plurality of spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>, and these spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>are used for current supply to the drive coils <b>141</b> and <b>142</b>; therefore, current can be supplied to the drive coils <b>141</b> and <b>142</b> by simply supplying current at one place in the optical axis direction, L. Thus, there is no need to supply current at two locations which are distanced from each other in the optical axis direction, L, and also no need to pull around one of the terminals to the vicinity of the other; thus, current can be easily supplied to the coils provided to the movable body.

0096Also, since the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>of the first flat spring <b>31</b> positioned opposite from the photographic subject side are used for current supply in this embodiment, the space for wiring can be reduced. In other words, since other electrical wiring such as the arrangement of the image pick-up device is done on the side opposite from the photographic subject side, the wiring may be gathered on the side opposite from the photographic subject side to reduce the wiring space and increase efficiency of the wiring operation.

0097Further, in this embodiment, the terminals <b>318</b><i>a </i>and <b>318</b><i>b </i>are integrally formed to the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>for external power supply. Therefore, there is an advantage in that there is no need to provide an additional terminal.

Other Embodiment

0098In the above embodiment, the first flat spring <b>31</b> and the second flat spring <b>32</b> are composed of the same material; however, they may be composed of different materials. More specifically described, the first flat spring <b>31</b> which is divided into the spring pieces <b>31</b><i>a </i>and <b>31</b><i>b </i>may be formed of a hard material that facilitates folding and cutting or a material excellent in conductivity while the second flat spring <b>32</b> which is not divided into pieces may be composed of a material excellent in resilience for the spring property.

0099In the above embodiment, the first flat spring <b>31</b> is divided into the two spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>; however, it may be divided into three or more pieces and the connection portion <b>140</b> between the first drive coil <b>141</b> and the second drive coil <b>142</b> may be electrically connected to another spring piece different from the one to which the coil end portion is connected.

0100Further, one of a plurality of spring pieces may be electrically connected to the back yoke <b>16</b> and a ground potential be applied to the back yoke <b>16</b> via the spring piece to configure a shield structure.

0101Furthermore, in the above embodiment, the first flat spring <b>31</b> is completely divided into the two spring pieces <b>31</b><i>a </i>and <b>31</b><i>b</i>; however, the spring pieces may be joined together by resin as long as they are separated electrically.

0102Also, the second flat spring <b>32</b> positioned on the photographic subject side may be divided into a plurality of spring pieces. Further, the terminals and the spring pieces may be formed separately and then the terminals may be attached to the spring pieces later or electrically connected by using another wiring material. To facilitate the folding of the flat spring member configuring unit <b>310</b> for cutting off, thin portions formed by half etching may be used in addition to the constricted portions.

0103Note that, although the drive magnet <b>17</b> is divided in the above embodiment, a single drive magnet <b>17</b> may be used. In the above embodiment, two drive coils are used; however, one drive coil may be used. On the other hand, one drive coil and two drive magnets may be used. Further, in the above embodiment, the drive magnets <b>17</b> and the drive coils <b>141</b> and <b>142</b> are opposed to each other in the optical axis direction, L; however, the drive coils <b>141</b> and <b>142</b> may be fixed to the outer periphery of the sleeve <b>15</b> and the drive magnets <b>17</b> may be fixed to the back yoke <b>16</b> so that they are opposed to the outer periphery of the drive coils <b>141</b> and <b>142</b>. Further, if an interlinked magnetic field can be produced to the drive coils <b>141</b> and <b>142</b> in the direction perpendicular to the optical axis, the drive magnets <b>17</b> can be magnetized in the axial line direction or magnetized on the inside and outside thereof in the radial direction. Also, to the sleeve <b>15</b>, the drive magnets, not the drive coils, can be fixed. In the above embodiment, the plate-like cover <b>18</b> may be composed of a magnetic material, and the entire side faces of the case <b>11</b>, the back yoke <b>16</b> and the base <b>19</b> may be covered by the plate-like cover <b>18</b>. In this way, the plate-like cover <b>18</b> can function as a shield material. Also, the portion of the plate-like cover <b>18</b> that covers the side face of the back yoke <b>16</b> may be formed of a magnetic material. In this way, the plate-like cover <b>18</b> can function as a supplement back yoke for intensifying the magnetism of the drive magnets <b>17</b>. In the above embodiment, the protrusions are formed to the movable body <b>3</b> and the recess portions are cut to the fixed body <b>2</b> to [together] create the stopper mechanism <b>101</b> (the first stopper mechanism); however, recess portions which are recessed inward in the radial direction may be formed to the movable body <b>3</b> and protrusions which come into the recess portions may be formed to the fixed body to [together] create the stopper mechanism <b>101</b> (the first stopper mechanism). Furthermore, although the four magnetic piece retaining holes are provided to the movable body <b>3</b>, only one magnetic piece retaining hole may be provided.

DESCRIPTION OF REFERENCES NUMERALS

0000<ul id="ul0002" list-style="none"><li id="ul0002-0001" num="0104"><b>2</b> Fixed body</li><li id="ul0002-0002" num="0105"><b>3</b> Movable body</li><li id="ul0002-0003" num="0106"><b>10</b> Lens driving apparatus</li><li id="ul0002-0004" num="0107"><b>15</b> Sleeve</li><li id="ul0002-0005" num="0108"><b>2</b> Flat spring (spring member)</li><li id="ul0002-0006" num="0109"><b>31</b><i>a</i>, <b>31</b><i>b </i>Spring piece</li><li id="ul0002-0007" num="0110"><b>141</b>, <b>142</b> Drive coil</li><li id="ul0002-0008" num="0111"><b>311</b>, <b>321</b> Outside frame portion</li><li id="ul0002-0009" num="0112"><b>312</b>, <b>322</b> Inside frame portion</li><li id="ul0002-0010" num="0113"><b>313</b>, <b>323</b> Arm portion</li></ul>

0114While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.

0115The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.