Tape printing apparatus

CROSS-REFERENCE TO RELATED APPLICATIONS

0001The present application claims priority from <patcit id="pcit0001" dnum="JP2006250799A"><text>JP 2006-250799</text></patcit>, filed on September 15.

BACKGROUND OF THE INVENTION

1. Field of the Invention

0002The present invention relates to a tape printing apparatus having a cutting device for cutting a long size roll sheet.

2. Description of Related Art

0003Conventionally, a variety of tape printing apparatuses having the cutting device for cutting the long size roll sheet throughout its entire width have been proposed. For example, there is available a tape printing apparatus having a slide type cutting device for cutting the roll sheet in the width direction by sliding its movable blade in the width direction of the roll sheet (for example, Japanese Patent Application Laid-open No.<patcit id="pcit0002" dnum="JP2002086823A"><text>2002-86823</text></patcit>).

0004The slide type described in the above-mentioned Japanese Unexamined Patent Publication No.<patcit id="pcit0003" dnum="JP2002086823A"><text>2002-86823</text></patcit> includes a cutter carrying mechanism for reciprocating a cutter unit having the movable blade in a cutting direction, so that the movable blade set at the home position is slid and the reciprocating motion of passing a printing medium in the width direction completely is achieved when cutting a printing medium. This cutter carrying mechanism has a problem that it is difficult to form into a thin configuration because it needs to be provided with a guide shaft for guiding the cutter unit and a lead screw which is engaged with the cutter unit to move the cutter. Further, the slide system has a problem that the durability of the movable blade is dropped because cutting points of the movable blade for cutting the roll sheet are concentrated locally.

0005Thus, a cutting mechanism (so-called guillotine cutter) which cuts the roll sheet with a fixed blade making contact with one side face of the roll sheet throughout the entire width in the width direction and a movable blade which after making contact with the entire width in the width direction on the other side face of the roll sheet, slides on this fixed blade moving in the thickness direction of the roll sheet can be considered. However, in the cutting mechanism comprised of the fixed blade and movable blade, no gap relative to a frame member is secured to protect the movable blade in a condition in which the movable blade is stored. For the reason, if a non-printing object surface of the roll sheet is provided with an adhesive agent layer, there is such a problem that an adhesive agent adheres to the movable blade and when the movable blade slides on the frame member to cut out the roll sheet, sliding resistance is caused thereby dropping durability performance of the cutting mechanism.

0006<patcit id="pcit0004" dnum="US2002056354A1"><text>US 2002/056354 A1</text></patcit> discloses a generic tape printing apparatus comprising a cutting device for cutting a long size roll sheet, wherein the cutting device comprises a fixed blade; a frame member in which the fixed blade is fixed; a roll sheet insertion port which is formed at a position opposing the fixed blade of the frame member and for passing a roll sheet through; a movable blade having a V-shaped tip which is movably provided to slide on the fixed blade for cutting out the roll sheet; and a movable blade driving device for reciprocating the movable blade on the frame member between a home position and a cutting position.

0007Other tape printing apparatus are known from <patcit id="pcit0005" dnum="US6118469A"><text>US 6,118,469</text></patcit> and <patcit id="pcit0006" dnum="EP1559566A1"><text>EP 1 559 566 A1</text></patcit>.

0008<patcit id="pcit0007" dnum="EP1541363A1"><text>EP 1 541 363 A1</text></patcit> discloses a printer including a cutting portion with a fixed blade and a movable blade. <patcit id="pcit0008" dnum="US20060137827A1"><text>US 2006/0137827 A1</text></patcit> discloses a guillotine cutter and tape affixing apparatus; and <patcit id="pcit0009" dnum="JPH11000892A"><text>JP H11 000892 A</text></patcit> discloses a cutter unit of a label printer having a vertically movable V-shaped blade provided with a recess serving as an adhesive agent accumulation portion.

SUMMARY OF THE INVENTION

0009Accordingly, the present invention has been accomplished to solve the above-described problem and an object of the disclosure is to provide a tape printing apparatus capable of improving durability performance of a cutting mechanism constituted of a fixed blade and a movable blade by preventing an adhesive agent adhering to the movable blade from causing resistance to sliding when the movable blade slides on a frame member.

0010To achieve the purpose of the disclosure, there is provided a tape printing apparatus according to claim 1.

0011Further developments of the invention are given in the dependent claims

BRIEF DESCRIPTION OF THE DRAWINGS

0012<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is a perspective view of an appearance of a tape printing apparatus of this embodiment as seen from its front face;</li><li><figref idref="f0002">FIG. 2</figref> is a perspective view of an appearance of the tape printing apparatus as seen from its rear face;</li><li><figref idref="f0003">FIG. 3</figref> is a perspective view showing a condition in which a roll sheet holder is loaded in the tape printing apparatus by opening a top cover, as seen from above to the right;</li><li><figref idref="f0004">FIG. 4</figref> is a perspective view showing a condition in which the roll sheet holder is loaded in the tape printing apparatus by opening the top cover as seen from above to the left;</li><li><figref idref="f0005">FIG. 5</figref> is a side sectional view showing a condition in which the roll sheet holder is loaded in the tape printing apparatus;</li><li><figref idref="f0006">FIG. 6</figref> is a schematic perspective view showing a condition in which a front cover is removed by opening the top cover of the tape printing apparatus as seen from above to the front;</li><li><figref idref="f0007">FIG. 7</figref> is a front view of a cutter unit;</li><li><figref idref="f0008">FIG. 8</figref> is a front view showing a condition in which the front frame of the cutter unit is removed;</li><li><figref idref="f0009">FIG. 9</figref> is a plan view showing a condition in which the front frame of the cutter unit is removed;</li><li><figref idref="f0009">FIG. 10</figref> is a rear view showing a condition in which the front frame of the cutter unit is removed;</li><li><figref idref="f0010">FIG. 11</figref> is a right side view showing a condition in which the front frame of the cutter unit is removed;</li><li><figref idref="f0010">FIG. 12</figref> is a sectional view taken along the line X1-X1 of <figref idref="f0008">FIG.8</figref>;</li><li><figref idref="f0011">FIG. 13</figref> is a rear view of the cutter unit when cutting of the roll sheet is started, for explaining an activity of the cutter unit;</li><li><figref idref="f0012">FIG. 14</figref> is a rear view of the cutter unit when the roll sheet is cut, for explaining an activity of the cutter unit;</li><li><figref idref="f0013">FIG. 15</figref> is a sectional view of major portions, taken along the line X2-X2 of <figref idref="f0011">FIG. 13</figref>, for explaining a cutting starting time of the roll sheet;</li><li><figref idref="f0013">FIG. 16</figref> is a sectional view of major portions taken along the line X3-X3 of <figref idref="f0012">FIG. 14</figref>, for explaining a cutting time of the roll sheet;</li><li><figref idref="f0014">FIG. 17</figref> is a sectional view of major portions taken along the line X2-X2 of <figref idref="f0011">FIG. 13</figref>, for explaining a cutting starting time of the roll sheet in the tape printing apparatus of other embodiment; and</li><li><figref idref="f0014">FIG. 18</figref> is a sectional view of major portions taken along the line X3-X3 of <figref idref="f0012">FIG. 14</figref>, for explaining a cutting time of the roll sheet in the tape printing apparatus of other embodiment.</li></ul>

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

0013Hereinafter, a preferred embodiment of a tape printing apparatus embodying the present invention will be described in detail with reference to the accompanying drawings. Embodiments

0014First, the schematic structure of the tape printing apparatus loaded with a roll sheet holder of this embodiment will be described based on <figref idref="f0001 f0002 f0003 f0004 f0005 f0006">FIGS. 1 to 6</figref>. As shown in <figref idref="f0001 f0002 f0003 f0004 f0005 f0006">FIGS. 1 to 6</figref>, in the tape printing apparatus 1, a main body case 2 and a roll sheet holder 3 on which a non-specified length holder sheet 3A (hereinafter referred to as "roll sheet 3A") of a predetermined width is wound are accommodated in a roll sheet holder accommodating portion 4. The top portion thereof is covered with a top cover 5 made of resin, the cover being attached to the top edge portion on the rear side such that it can be opened/closed freely. A check window 5A made of transparent resin is formed in the top face portion of this top cover 5 so that the roll sheet 3A loaded in the holder accommodating portion 4 can be confirmed visually.

0015A power button 7A, a feed button 7B for discharging the roll sheet 3A in a carrying direction while it is kept pressed and a cut button 7C for cutting the roll sheet 3A by driving the cutter unit 8 covered with the front cover 6 when it is pressed are provided on a side end portion (right end portion in <figref idref="f0001">FIG. 1</figref>) on one side of the front side of the upper cover 5. The front cover 6 includes a sheet discharge port 6A for discharging the printed roll sheet 3A outside.

0016An inlet 9 to which a power cord (not shown) is to be connected is disposed on an end portion on one side of the rear face portion of the main body case 2 and a blower fan (not shown) is disposed on a side thereof. Further, a universal serial bus (USB) connector 10 to be connected to a personal computer (not shown) and a connecting connector 11 are provided on the side portion on the other side.

0017As shown in <figref idref="f0005">FIG. 5</figref>, this roll sheet 3A is constituted by bonding together long size heat sensitive sheet (so-called thermal paper) 3C having self color generating characteristic and peeling paper 3E via an adhesive agent layer 3D provided on the rear face side of this heat sensitive sheet 3C and wound around such that printing object face of the heat sensitive sheet 3C is located inside.

0018As shown in <figref idref="f0003">FIGS. 3</figref>, <figref idref="f0004">4</figref> and <figref idref="f0006">6</figref>, the tape printing apparatus 1 has a holder supporting member 15 in which an attachment member 13 having a substantially rectangular section which is projected outward of the positioning member 12 constituting the roll sheet holder 3 can be fitted on a side edge portion (right side end portion in <figref idref="f0003">FIG. 3</figref>) on one side in a substantially perpendicular direction to the carrying direction of the roll sheet holder accommodating portion 4. This holder supporting member 15 includes a first positioning groove portion 16 formed in a substantially longitudinally long U shape in its front view, which is open upward in the width direction and at the same time open to both sides in the width direction.

0019A loading portion 21 on which the front side top end portion of the guide member 20 constituting the roll sheet holder 3 described later is to be placed is provided such that it is extended substantially horizontally from the rear end portion of an insertion port 18 to which the roll sheet 3A is to be inserted up to the top end portion on the front side of the roll sheet holder accommodating portion 4. Seven second positioning groove portions 22A to 22G having a substantially L-shaped section are formed corresponding to a plurality of width dimensions of the roll sheet 3A on an edge corner portion on the rear side in the carrying direction of this loading portion 21. As shown in <figref idref="f0005">FIG. 5</figref>, the second positioning groove portions 22A to 22G are formed such that the bottom end portion on the front end to come into contact with the loading portion 21 of the guide member 20 constituting the load sheet holder 3 can be fitted thereto from above.

0020A positioning concave portion 4A of a rectangular shape with a longer side as seen in its plan view is formed in a predetermined depth (about 1.5 to 3 mm in this embodiment) substantially vertically to the carrying direction from the inside proximal end portion of the holder supporting member 15 up to the proximal end portion of an opposing side face in the bottom portion of the roll sheet holder accommodating portion 4. The carrying direction width dimension of this positioning concave portion 4A is set substantially equal to the width dimension of each of the bottom end portion of the positioning member 12 and the guide member 20 which constitute the roll sheet holder 3. Further, a determining concave portion 4B of a rectangular shape with a longer side along the carrying direction as seen in its plan view is formed so that a portion opposing a sheet determining portion (not shown) extending inward substantially at right angle from the bottom end portion of the positioning portion 12 is deeper than the positioning concave portion 4A by a predetermined depth (a depth of about 1.5 to 3 mm in this embodiment), the same determining concave portion being formed on the proximal end inside of the holder supporting member 15 of the positioning concave portion 4A.

0021This determining concave portion 4B includes six sheet determining sensors P1, P2, P3, P4, P5, P6 arranged in an L-shape each constituted of push type micro switch or the like in order to determine the type of the roll sheet 3A and material of the heat sensitive sheet 3C, the width of the roll sheet 3A and the like. In the meantime, <figref idref="f0006">FIG. 6</figref> indicates five sheet determining sensors P1 to P5.

0022The sheet determining sensors P1 to P6 are constituted of a known mechanical switch composed of a plunger, micro switch and the like and the top end portion of each plunger is provided to project from the bottom face portion of the determining concave portion 4B up to the vicinity of the bottom face portion of the positioning concave portion 4A. The sheet determining sensors P1 to P6 detect whether or not there is any sensor hole (not shown) formed in a sheet determining portion extending inward substantially at right angle from the bottom end portion of the positioning member 12 so as to detect the type of the roll sheet 3A loaded in the roll sheet holder 3, material of the heat sensitive sheet 3C, width of the roll sheet 3A and the like depending on an ON/OFF signal.

0023In each sheet determining sensor P1 to P6 of this embodiment, its plunger is projected up to the vicinity of the bottom face of the positioning concave portion 4A from the bottom face of the determining concave portion 4B and the micro switch is kept OFF normally. Then, when the sensor hole in the sheet determining portion is located at a position opposing each of the sheet determining sensors P1 to P6, the plunger is not pressed so that the micro switch is kept OFF and thus, an OFF signal is outputted. On the other hand, if the sensor hole in the sheet determining portion is not located at a position opposing the sheet determining sensors P1 to P6, the plunger is pressed to turn ON the micro switch and then an ON signal is outputted. Thus, the respective sheet determining sensors P1-P6 output 6-bit "0", "1" signals and when the respective sheet determining sensors P1 to P6 are all OFF, namely, no roll sheet holder 3 is mounted, a 6-bit signal of "000000" is outputted.

0024A side end portion (right end portion in <figref idref="f0003">FIG. 3</figref>) on the side of a holder supporting member 15 of the insertion port 18 is formed at a position opposing the inside end face of the positioning member 12 to be fitted to the holder supporting member 15. Further, a guide wall face is formed on the side end portion on the side of the holder supporting member 15 of the insertion port 18 such that it is raised up to almost a rear end portion in the carrying direction in the loading portion 21 and a guide portion 23 projecting by a specified width in the width direction is formed to cover the top face portion of the roll sheet 3A and the roll sheet 3A is passed therebelow.

0025A platen roller 26 is supported rotatably on the bottom side of the front end portion of the top cover 5. A thermal head 31 is fixed to the top face of a head supporting member 32 urged upward by a pressing spring 24. The end portion on the rear side in the carrying direction of this head supporting member 32 is supported swingably in a vertical direction by the rear face portion of the frame 33. A guide portion 34 of a predetermined width (about 15 mm in this embodiment) extending outward is fitted into a guide hole 35 (see <figref idref="f0007">FIG. 7</figref>) provided in the front face portion of the frame 33 in the center of the end portion on the front side in the carrying direction of the head supporting member 32 such that it can be moved in the vertical direction.

0026When the top cover 5 is closed, the platen roller 26 depresses the roll sheet 3A against the thermal head 31 urged upward by the pressing spring 24 so as to enable printing to be carried out. Additionally, when the top cover 5 is closed, respective collar members 25, 25 fitted rotatably to the outer periphery of both end portions of a roller shaft 26A of the platen roller 26 are secured by respective pawl portions 28, 28 having a substantially inverted L shape in its side view urged backward in the carrying direction. A gear 26B is fixed at an end portion on the side of the holder supporting member 15 of the roller shaft 26A and when the top cover 5 is closed, it meshes with a gear string (not shown) so that the platen roller 26 can be rotated by a sheet feeding motor (not shown) constituted of a stepping motor or the like.

0027When release knobs 27, 27 provided on right and left side wall portions of the main body case 2 are pressed upward, the respective engaging pawls 28, 28 are rotated forward in the carrying direction resisting an urging force, so that engagement with each collar member 25 is released. Consequently, the platen roller 26 is urged upward by the thermal head 31 and the top cover 5 is brought slightly upward thereby enabling the top cover to be opened.

0028A control board 36 having a control circuit portion for controlling driving of each mechanical component according to an instruction from a personal computer outside or the like is provided on the bottom portion of the roll sheet holder portion 4. A power supply board 37 containing a power circuit portion is provided below the frame 33. Then, the control board 36 and the power supply board 37 are covered with a bottom face cover 38 made of thin steel plate (steel plate such as SPCC about 0.5 mm thick in this embodiment) screwed to the bottom face portion.

0029Consequently, the roll sheet holder 3 on which the roll sheet 3A wound around a core is loaded is mounted detachably on the roll sheet holder accommodating portion 4 by fitting the attachment member 13 of the positioning member 12 into a first positioning groove portion 16 of the holder supporting member 15 and then fitting a bottom end portion of the front end of the guide member 20 into any of second positioning groove portions 22A to 22G so that the bottom end portion of the guide member 20 is fitted into a positioning concave portion 4A and brought into a contact therewith. A sheet determining portion provided on the bottom end portion inside of the positioning member 12 is inserted into a determining concave portion 4B, so as to make it possible to detect whether or not each sensor hole in the sheet determining portion opposing the respective sheet determining sensors P1 to P6 disposed on the determining concave portion 4B exists. That is, the type of the roll sheet 3A loaded on the roll sheet holder 3 can be detected.

0030With the side edge portion on one side of the roll sheet 3A in contact with the inside face of the guide member 20, the side edge portion on the other side of this roll sheet 3A is brought into a contact with the guide portion 23 provided on the side edge portion of the insertion hole 18 and a inserted into the insertion hole 18, and then when the top cover 5 is closed, printing is enabled.

0031When the top cover 5 is closed as shown in <figref idref="f0005">FIG. 5</figref>, the roll sheet 3A is pressed and urged against the line type thermal head 31 urged upward by the pressing spring 24 so that printing is enabled. The platen roller 26 is rotated by the sheet feeding motor (not shown) constituted of a stepping motor or the like and the driving of the thermal head 31 is controlled to carry the roll sheet 3A to print image data on a print face of a heat sensitive sheet 3C in succession. When a cutting position on the rear side in the carrying direction of a printed roll sheet 3A is carried up to a position opposing a fixed blade 41 of the cutter unit 8, as described later, a movable blade 42 shaped in letter V in its front view of the cutter unit 8 is reciprocated in the vertical direction by a cutting motor 43 such as a DC motor (see <figref idref="f0007">FIG. 7</figref>) so that the roll sheet 3A is cut out (see <figref idref="f0013">FIG. 16</figref>) by the fixed blade 41 and the movable blade 42 and a cut sheet is discharged from the sheet discharge port 6A.

0032Next, the schematic structure of the cutter unit 8 will be described with reference to <figref idref="f0005">FIGS. 5</figref>, <figref idref="f0007 f0008 f0009 f0010">7 to 12</figref>. As shown in <figref idref="f0005">FIGS. 5</figref>, <figref idref="f0007 f0008 f0009 f0010">7 to 12</figref>, the cutter unit 8 comprises a rear frame 51 formed in U shape in its plan view which is disposed on the rear side in the carrying direction and on which the fixed blade 41 or the like is fixed, a front frame 52 on which the cutting motor 43 or the like is fixed and which covers the front side in the carrying direction of the rear frame 51.

0033As shown in <figref idref="f0005">FIGS. 5</figref>, <figref idref="f0007">7</figref>, the left bottom corner of the front frame 52 in <figref idref="f0007">FIG. 7</figref> is cut out and a predetermined length (about 12mm in this embodiment) thereof is bent in an inward direction substantially at right angle and then, the cutting motor 43 is attached via a motor flange 53. A cam gear 55 is attached rotatably in a substantially central portion of the front frame 52 opposing the movable blade 42. The cam gear 55 is rotated via a pinion gear 43A, a gear 56 and a worm gear 57 mounted on a motor shaft of the cutting motor 43 by the cutting motor 43.

0034A drive pin 59 fitted into an elongated cam groove 61 (see <figref idref="f0008">FIG. 8</figref>) provided in a guide portion 42A (see <figref idref="f0008">FIG. 8</figref>) of the movable blade 42 is provided projectingly in the vicinity of the outer periphery on an end face on the side of the movable blade 42 of the cam gear 55. The front frame 52 has a home position detecting switch 60 for detecting the lowest point of the drive pin 59 erected on this cam gear 55, namely, the position of the home position to the right of the cam gear 55 in <figref idref="f0007">FIG. 7</figref>. A pressing portion 55A for pressing this home position detecting switch 60 is formed on the outer peripheral portion of the cam gear 55 when the drive pin 59 is located at the lowest point, namely, the position of the home position and capable of detecting that the cam gear 55 is rotated by a single turn from the home position by driving the cutting motor 43. Thus, when the tape printing apparatus 1 is started, the cam gear 55 is located at the home position and set at a position in which the home position detecting switch 60 is pressed via the pressing portion 55A.

0035As shown in <figref idref="f0008 f0009 f0010">FIGS. 8 to 12</figref>, in the rear frame 51 to which the front frame 52 is to be mounted, its right and left end portions are bent substantially at right angle in a forward direction of the carrying direction so as to form left side wall portion 51A and right side wall portion 51B. Further, the bottom edge portion of the rear frame 51 is bent by a predetermined width (about 5 mm in this embodiment) substantially at right angle in a forward direction of the carrying direction and a front frame receiving portion 51C which extends by a predetermined length (about 12 mm in this embodiment) in the forward direction of the carrying direction is formed substantially in the center thereof.

0036An elongated opening portion 62 through which the roll sheet 3A passes is provided in the rear frame 51. The fixed blade 41 longer than the lateral width of the opening portion 62 is screwed with screws 63, 63 to the top edge portion of the opening portion 62 between the respective side wall portions 51A and 51B on the front side in the carrying direction. The tip of the fixed blade 41 is situated slightly below the top edge portion of the opening portion 62 (below the top edge portion of the opening portion 62 by about 1 mm - 1.5 mm in this embodiment) such that it can make contact with an entire width of the roll sheet 3A.

0037Both right and left end portions of the movable blade 42 are extended upward with a substantially identical width into a gap between the right/left side end portions of the opening portion 62 and the side wall portions 51A, 51B and when the movable blade 42 is situated at the lowest point, namely, the home position, the top end portions ride over both right and left end portions of the fixed blade 41 so as to form respective guide portions 42B, 42C.

0038The bottom end portion of the opening portion 62 of the rear frame 51 is located at a position lower by a predetermined length (about 3 mm - 5mm in this embodiment) than the bottommost end portion of the V-shaped tip of the movable blade 42 when the movable blade 42 is situated at the lowest point, that is, the home position (see <figref idref="f0009">FIG. 10</figref>). Then, when the movable blade 42 is situated at the lowest point, there is formed a gap of a predetermined distance in the vertical direction between the bottommost end portion of the V-shaped tip of the movable blade 42 and the bottom end portion of the opening portion 62. An extending portion 64 which extends backward in the carrying direction substantially at right angle from the bottom edge portion of the opening portion 62 is formed so that it makes contact with the front side face in the carrying direction of the frame 33.

0039A flat-sheet, U-shaped movable blade guide member 65 which is open upward in its front view is disposed substantially in the center on the front side in the carrying direction below the opening portion 62 of the rear frame 51. Then, the right/left side face portions of a guide portion 42A extending downward from the bottom end portion of the V-shaped movable blade 42 are supported by this movable blade guide member 65 such that they can be reciprocated freely in the thickness direction of the roll sheet 3A. A substantially semicircular pressing spring 66 is secured to the rear frame 51 together with the guide member 65 with screws 67, 67 such that it can press the front face side of the movable blade 42 along substantially the center line in the right-left direction and the above-mentioned right/left side face portions are supported such that they can be reciprocated in the thickness direction of the roll sheet 3A with the movable blade 42 pressed against the fixed blade 41 side. A convex portion 66A whose side section is substantially semi-circular, projecting backward in the carrying direction is formed at the top end portion of the pressing spring 66 thereby reducing contact resistance of the movable blade 42.

0040A through hole 68 of a predetermined diameter is provided in a portion opposing the cam groove 61 of the movable blade 42 of the rear frame 51 so that the drive pin 59 fitted into this cam groove 61 can be moved circularly with a rotation of the cam gear 55.

0041Cutting of the roll sheet 3A by the cutter unit 8 having the above-described structure will be described with reference to <figref idref="f0011 f0012 f0013">FIGS. 13 to 16</figref>. When cutting of the roll sheet 3A is started, as shown in <figref idref="f0011">FIGS. 13</figref>, <figref idref="f0013">15</figref>, the pressing portion 55A of the cam gear 55 is located at the home position which presses the home position detecting switch 60 and the drive pin 59 is located at the lowest point, so that the movable blade 42 is located at the lowest point. The roll sheet 3A printed by the thermal head 31 is carried into the opening portion 62 and with an end portion on the rear side in the carrying direction of the roll sheet 3A pressed by the platen roller 26 against the thermal head 31 so that it is nipped therebetween, the other end portion is projected from the sheet discharge port 6A.

0042When the cam gear 55 is rotated by 180° from the home position by driving the cutting motor 43 as shown in <figref idref="f0012">FIGS. 14</figref>, <figref idref="f0013">16</figref>, the drive pin 59 is moved to a position at the topmost end while it slides in the cam groove 61 of the movable blade 42, so that the bottommost end portion of the V-shaped tip of the movable blade 42 is moved to above the fixed blade 41. Consequently, the roll sheet 3A carried into the opening portion 62 is cut out throughout the entire width in the width direction. Further, an adhesive agent of an adhesive agent layer 3D of the roll sheet 3A adhering to the tip of the movable blade 42 is moved to a position of a height near the bottommost end portion of the V-shaped tip of the movable blade 42 with sliding between the movable blade 42 and the fixed blade 41, so that an adhesive agent accumulation portion 71 (shaded portion of the movable blade 42 in <figref idref="f0012">FIG. 14</figref>) in which an adhesive agent is accumulated is formed along the tip of the fixed blade 41.

0043When the cutting motor 43 is stopped after the pressing portion 55A of the cam gear 55 is rotated until it presses down the home position detecting switch 60 by driving the cutting motor 43, that is, when the cutting motor is stopped after the cam gear 55 is rotated by 360° from the home position, the drive pin 59 is located at the lowest point again as shown in <figref idref="f0011">FIGS. 13</figref> and <figref idref="f0013">15</figref>, so that the movable blade 42 is located at the lowest point. As described above, the bottom end portion of the opening portion 62 is located at a position lower by a predetermined length (about 3 mm to 5 mm in this embodiment) than the bottommost end portion of the V-shaped tip of the movable blade 42 by a predetermined height. Thus, the adhesive agent accumulation portion 71 formed near the bottommost end portion of the V-shaped tip of the movable blade 42 is located above the bottom end portion of the opening portion 62, so that contact between the adhesive agent accumulation portion 71 and the rear frame 51 can be avoided.

0044As shown in <figref idref="f0013">FIG. 15</figref>, an extending portion 64 of the rear frame 51 makes contact with the front side face in the carrying direction of the frame 33. If the cut roll sheet 3A or the like enters the opening portion 62 through the sheet discharge port 6A, it makes contact with this extending portion 64 to prevent it from invading into the tape printing apparatus 1.

0045Therefore, in the tape printing apparatus 1 of this embodiment, when the roll sheet 3A is cut out, the adhesive agent in the adhesive agent layer 3D of the roll sheet 3A adhering to the movable blade 42 is moved up to a position of height near the bottommost end portion of the V-shaped tip of the movable blade 42 by sliding between the movable blade 42 and the fixed blade 41 and the adhesive agent accumulation portion 71 in which an adhesive agent is accumulated is formed along the tip of the fixed blade 41. When the movable blade 42 is lowered to the position corresponding to the home position at the lowest point, the adhesive agent accumulation portion 71 formed near the bottommost end portion of the V-shaped tip of the movable blade 42 is located above the bottom edge portion of the opening portion 62.

0046Consequently, the adhesive agent accumulation portion 71 formed at the position of height near the bottommost end portion of the V-shaped tip of the movable blade 42 is always moved in the thickness direction of the roll sheet 3A, namely, in the vertical direction within the opening portion 62. Thus, contact between the adhesive agent accumulation portion 71 and the rear frame 51 can be avoided securely thereby preventing an adhesive agent adhering to the movable blade 42 from causing resistance to sliding with respect to the rear frame 51 with a simple structure. As a result, the durability performance of the cutter unit 8 constituted of the fixed blade 41 and the movable blade 42 or the like can be improved tremendously.

0047Because the extending portion 64 of the rear frame 51 is kept in contact with the front side face in the carrying direction of the frame 33, when the cut roll sheet 3A or the like enters the opening portion 62 through the sheet discharge port 6A, it comes into contact with this extending portion 64 so that it is prevented from invading into the tape printing apparatus 1.

0048Needless to say, the present invention is not restricted to the above-described embodiment but may be improved or modified in various ways within a range not departing from the scope of the appended claims.

0049As shown in <figref idref="f0014">FIGS. 17, 18</figref>, in the cutter unit 8, the height of the bottom end portion of the opening portion 62 in the rear frame 51 is formed to be situated near the top end portion of the tip of the movable blade 42 and the height in the vertical direction of the opening portion 62 is so set that the roll sheet 3A can pass therethrough. Further, it is permissible to provide an expanding portion 81 which starts expanding from a portion lower by a predetermined length (about 3 to 5 mm in this embodiment) than the bottommost end portion of the V-shaped tip of the movable blade 42 at the home position while keeping a predetermined distance (for example, a distance of about 3 mm to 5 mm) backward in the carrying direction throughout the entire longitudinal direction of the opening portion 62.

0050Consequently, this expanding portion 81 functions as a keep-off spatial portion and the adhesive agent accumulation portion 71 formed at the position of height near the bottommost end portion of the V-shaped tip of the movable blade 42 always move in the thickness direction of the roll sheet 3A, namely, the vertical direction within the expanding portion 81, so that contact between the adhesive agent accumulation portion 71 and the rear frame 51 can be avoided securely. Consequently, adhesive agent adhering to the movable blade 42 can be prevented from causing resistance to sliding with respect to the rear frame 51 with a simple structure, thereby improving durability performance of the cutter unit 8 constituted of the fixed blade 41 and the movable blade 42 or the like tremendously. When the cut roll sheet 3A or the like enters the opening portion 62 through the sheet discharge port 6A, it makes contact with this expanding portion 81 so that it can be blocked from invading into the tape printing apparatus 1.

0051In the disclosed tape printing apparatus, it is preferable that the keep-off spatial portion contains a window portion formed by cutting out a side edge portion on the side of the movable blade in the roll sheet insertion port by a predetermined width in a moving direction of the movable blade.

0052In the disclosed tape printing apparatus, it is preferable that the side edge portion on the side of the movable blade in the window portion is formed to oppose a portion outside in the moving direction of the movable blade, relative to a sliding portion between the movable blade and the fixed blade when the movable blade reaches a position most apart from the fixed blade.

0053In the disclosed tape printing apparatus, it is preferable that the window portion has an extending portion extending to an insertion side in a roll sheet insertion direction from the side edge portion on the side of the movable blade, the extending portion being so constructed that when a cut roll sheet invades from the window portion, the cut roll sheet comes into contact therewith.

0054In the disclosed tape printing apparatus, it is preferable that the keep-off spatial portion has an expanding portion which starts expanding from a position lower by a predetermined length than an end of a sliding portion of the movable blade in a state of drawing back most apart from the fixed blade in the frame member and reaches the bottom side edge portion of the roll sheet insertion port, expanding by a predetermined distance toward the upstream side in a carrying direction of the roll sheet throughout an entire width of the roll sheet insertion port.

0055In the tape printing apparatus of the disclosure, if the keep-off spatial portion contains the window portion formed by cutting out the side edge portion on the side of the movable blade in the roll sheet insertion port by a predetermined width in the moving direction of the movable blade, when the movable blade is reciprocated on the frame member, adhesive agent adhering to the movable blade can be prevented from causing resistance to sliding with a simple structure.

0056In the tape printing apparatus of the disclosure, the side edge portion on the side of the movable blade in the window portion may be formed to oppose a portion outside in the moving direction of the movable blade, relative to a sliding portion between the movable blade and the fixed blade when the movable blade reaches a position most apart from the fixed blade. Consequently, even when adhesive agent adhering to the movable blade is accumulated on the edge portion of the sliding portion by sliding between the movable blade and the fixed blade, adhesive agent adhering to the movable blade can be prevented from causing resistance to sliding with respect to the frame member securely, because the side edge portion on the side of the movable blade in the window opposes a portion outside in the moving direction of the movable blade relative to the sliding portion in which the adhesive agent is accumulated.

0057In the tape printing apparatus of the disclosure, the window portion may have an extending portion extending to an insertion side in the roll sheet insertion direction from the side edge portion on the side of the movable blade, the extending portion being so constructed that when a cut roll sheet invades from the window portion, the cut roll sheet comes into contact therewith. Consequently, when the cut roll sheet enters into the window portion by mistake, it comes into contact with this extending portion, so that it can be prevented from invading into the tape printing apparatus.

0058In the tape printing apparatus of the disclosure, the keep-off spatial portion may be so constructed that a part of the keep-off spatial portion starts expanding from a position lower by a predetermined length than an end of a sliding portion of the movable blade in a state of drawing back most apart from the fixed blade in the frame member and reaches the bottom side edge portion of the roll sheet insertion port, expanding by a predetermined distance toward the upstream side in a carrying direction of the roll sheet through out an entire width of the roll sheet insertion port. Consequently, even when an adhesive agent adhering to the movable blade is accumulated on the edge portion of the sliding portion by sliding between the movable blade and the fixed blade, the adhesive agent accumulated on the side edge portion of this sliding portion can be prevented from causing resistance to sliding relative to the frame member, because the expanding portion of the frame is expanded by a predetermined distance to the upstream side in the carrying direction of the roll sheet.