Compact pointing device

The present invention relates to a pointing device for controlling a cursor on a display.

To simplify the discussion below, the invention describes pointing devices utilized in computers, however, the invention covers a wide range of data processing, including handheld computers, mobile phones, video games, and the like. Used with the system. Modern computer operating systems and graphics programs require a pointing device to control the position of the cursor on the computer display. For desktop PCs, the most successful pointing device is the "mouse". A mouse is a handheld object that moves on a flat surface near the keyboard and controls the movement of the cursor on a computer display. The direction and distance the mouse moves defines the direction and distance the cursor moves on the display. Traditional mice provide a rigid object that the user can move very accurately. For desktop computers, the mouse provides a satisfactory solution to the alignment problem. If the work environment is not wide enough to move the mouse and provide a path corresponding to the desired cursor movement on the display, the user simply picks up the mouse and recenters it in the workspace. Put in.

In the desktop PC market, mice provide a satisfactory solution to the problem of pointing devices, but similar successful devices are not available for portable and handheld computers. These computers are often used in environments that lack a sufficiently wide flat surface near a keyboard on which the mouse can be moved. Therefore, some other form of pointing device is used when using those computers in such an environment.

Pointing devices for use in those environments must solve the problem of quick and accurate cursor movement. In addition, the device must be able to operate in an intuitive way that an inexperienced user can understand, without a wealth of instructions. In addition, the pointing device must be operated in a limited working environment and fit within the computer's form factor or handheld device. Ultimately, it meets the usual constraints of low cost, low power output, and high reliability.

Currently, there are two main solutions to the problem of pointing devices on laptop computers, Synaptics' capacitive touchpad® and IBM's TrackPoint®. Other companies also manufacture variants of those devices with similar functionality. Both of these devices are far from satisfying the above requirements. TrackPoint® is a small button that is generally located in the center of a laptop keyboard. The button is moved in a manner similar to a "joystick" by applying a lateral force to the top of the button with a finger. Unfortunately, the button moves only a small amount, so the amount of movement of the button cannot be directly converted to the amount of movement of the cursor position on the computer display. Instead, the amount of movement of the button controls the direction and speed at which the cursor moves. The accuracy with which the user can position the cursor using this form of speed control is significantly less than achieved with conventional mice. This limitation is especially apparent for tasks that require small and accurate movements, such as those drawn by computer graphics programs.

A touchpad® is a rectangular blank pad with a side of 50-100 mm that is generally located in front of many laptop keyboards. The device detects the position of the finger on the surface of the rectangle with respect to the sides of the device. This detection is achieved by measuring the change in capacitance guided by the user's finger on a series of electrodes beneath an insulated low friction material.

Like the TrackPoint®, the Touchpad® lacks accuracy. It is inherently difficult to measure capacitance changes induced by users with unknown potentials to the circuit. Further, the area of contact with the user's finger is relatively large. Therefore, in order to accurately measure the position of the finger, the device must determine some parameter, such as the center in the contact area between the finger and the pad. Unfortunately, the size and shape of the contact area will vary depending on the pressure applied by the user. Such a determination is best with limited accuracy. In fact, the user cannot repeat and perform accurate actions.

<p> If the user unknowingly touches the pad with a finger or wrist, the wrong signal can cause problems. On some devices, tapping the pad performs the traditional mouse "click" function. As a result, such inadvertent action between types can cause the cursor to jump to a new location or insert text into a new location during a typing operation.</p>

<p> The present invention relates to a pointing device having a movable pack that moves on the surface of the pack operating area. The position detector measures the position of the puck within the puck operating area. In one embodiment, the position detector comprises a surface electrode on the surface and a puck electrode that moves with the puck, and the position detector measures the capacitance between selected ones of a plurality of electrodes. In another embodiment, the position sensor measures the flow of current between selected ones of multiple electrodes. In another embodiment, the pack comprises a user sensor that detects the interaction between the user and the pack. In another embodiment, the user sensor includes a force sensor that generates a first signal indicating a first predetermined force applied to the pack by the user. In another embodiment, the force sensor generates a signal when the force exceeds a second predetermined force level and / or a signal indicating the magnitude of the force. When the user sensor detects the interaction between the user and the puck, the controller causes the cursor to move on the display in response to the movement of the puck within the puck operating area. The magnitude and direction of cursor movement is defined by the magnitude and direction of puck movement within the puck movement area. In yet another embodiment, a restoration mechanism is provided to return the pack to a predetermined area of the pack operating area when the user releases the pack. An embodiment in which the restoration mechanism utilizes a spring or a magnetic field will be described.</p>

How the present invention brings its benefits can be more easily understood by referring to FIGS. 1A-1B, which illustrates the pointing device 10 according to an embodiment of the present invention. FIG. 1A is a plan view of the pointing device 10, and FIG. 1B is a cross-sectional view of the pointing device 10 along the line 1B-1B shown in FIG. 1A. The pointing device 10 includes a pack 11 that moves on the surface 12 of the substrate 15 within the pack operating region 19 in response to a lateral force applied to the pack 11. In general, the force is applied by the user's fingers, fingertips, thumb, thumb tip, and multiple fingers. Pack 11 includes a pressure sensing mechanism that measures the vertical pressure applied to pack 11. In addition, the pointing device 10 includes a detection mechanism that determines the position of the pack 11 on the surface 12.

See further FIG. 2A-2B, which illustrates the control of the cursor on the display 100 by the pack described above. When the user applies a vertical force greater than a predetermined threshold to the pack 11, any change in the position of the pack 11 on the surface 12 is transmitted to the host device on which the pointing device 10 forms the portion. The repositioning is used to move the cursor on the display by the magnitude and direction of movement of the pack 11 while the vertical force is applied to the pack 11. .. That is, if the motion of the pack 11 is characterized by a distance d and a direction defined by an angle φ on the pointing device, then the motion of the cursor 101 is defined by a distance D and an angle φ on the display 100. Characterized by direction.

When the user releases the pack 11 by releasing the user's finger 16, the pack 11 is returned to its center position by the spring 13 indicated by the reference number 13 that connects the pack to the side 14 of the pack operating area. Since the user's finger does not apply a force perpendicular to the pack 11 to the pack 11 while the pack returns, the position change associated with that return motion is not transmitted to the host device. That is, the cursor 101 remains at the position of reference number 102. This generally provides a convenient "recentering" function achieved in the mouse by lifting and repositioning the mouse in the center of the motion area. Recentering is especially needed in laptop computers, handheld devices, and other small applications with limited operating areas.

In a preferred embodiment of the invention, the pressure sensor in Pack 11 detects two predetermined levels of pressure. The first level is used to track the cursor on the display, as described above. The second level is used to perform the "click" function associated with traditional mice. Therefore, the user can click at the current position of the cursor by increasing the force applied to pack 11. Mechanical clicks can also be designed to provide tactile feedback on the "click" threshold.

Further refer to FIG. 3, which shows a more detailed cross section of the pack of the present invention. Pack 20 includes a movable component 21 suspended above the cavity 26. The distance between the component 21 and the bottom surface 25 of the cavity 26 varies depending on the pressure applied to the top surface of the component 21. In the embodiment shown in FIG. 3, component 21 is a deformable membrane suspended from the spacer shown by reference numeral 27. The distance the component 21 has traveled from its rest position is a measure of the force applied to the component 21. This distance can be detected by any suitable mechanism.

For example, two pressure switches are indicated by reference numbers 23 and 24. Each pressure switch is open when the force applied to the component 21 is less than a predetermined value, and the value is different for each switch. When the component 21 is pushed downwards, the switch 23 first engages and switches to a conductive state. This switch signals the host device where the pointing device is started. At this point, the host device measures the position of the pointing device and changes the position of the cursor on the display according to those measurements.

When the force on the component 21 increases above a predetermined second level, the switch 24 is also closed. The state of this switch is independently monitored by the host device on which the pointing device forms its part, or the controller which is part of the pointing device itself. In a conventional mouse, a user-enabled button signals the host device to acquire some particular annotation at the current position of the cursor on the display. Closing the switch by pressing this button is often referred to as "clicking" at the current cursor position. Switch 24 is used to provide this click function in pointing devices that utilize Pack 20.

The above embodiment of Pack 20 utilizes a separate switch for detecting two thresholds of force. However, a force threshold for activating the cursor track and click functions is provided utilizing a single pressure sensing component that provides an analog measurement of the position of the surface of component 21 with respect to the bottom surface 25 of the cavity. be able to. For example, component 21 includes an electrode that forms a capacitor with the relevant component on the bottom of the cavity. As the distance between the surface of component 21 and the bottom of the cavity changes, so does the capacitance of that capacitor. The change in capacitance can be measured by any of many conventional circuits and is used to determine the distance between component 21 and the bottom of the cavity. In this case, the two capacitance thresholds define the above two force thresholds.

The above embodiment, which utilizes the elasticity of the component 21 to provide a mechanism for converting the force applied to the component 21 into its distance, is measurable. However, there are many other known mechanisms for providing that function. For example, the cavity 26 can be filled with a compressible medium such as rubber. In yet another embodiment, rigid movable components suspended on the surface by a spring mechanism can be utilized.

Further refer to FIG. 4, which shows a cross section of another embodiment of the pack utilized in the pointing device of the present invention. Pack 30 contains a cavity 36 seen, with a rigid member 31 which is suspended on the bottom of the cavity 36 by a spring. An exemplary spring is shown by reference number 38. If no downward force is applied to the member 31, the member 31 is held in place by the retaining ring indicated by reference numeral 37. When a force is applied in the direction indicated by reference numeral 39, the member 31 moves towards the bottom of the cavity by a distance that depends on the applied force and the spring constant of the spring 38. Measuring the capacitance between electrodes 32 and 33 provides a measurement of the distance between member 31 and bottom 35.

See further in FIG. 5, which illustrates an equivalent circuit formed by the electrodes shown in FIG. Electrodes 32, 33, 34 form an electrical circuit equivalent to two capacitors connected in series with electrode 34 as common electrodes. Capacitor C₁Represents the capacitance between electrodes 33 and 34, capacitor C₂Represents the capacitance between electrodes 32 and 34. The total capacitance between electrodes 32 and 33 depends on the distance between electrodes 34 and electrodes 32, 33. This capacitance is omitted from the figure for the sake of simplicity, but is detected using an external electrical connection to electrodes 32 and 33. The proposed capacitance measurement does not require an external electrical connection to the electrode 34 and is therefore inexpensive and simple to implement. However, other embodiments based on the measurement of capacitance between the electrode 34 and one or both of the electrodes 32 and 33 can be used as an alternative.

Although the pack embodiments described above utilize volumetric measurements to detect the distance between the movable component and the bottom of the cavity, other measurement techniques can also be utilized. See further in FIG. 6, which shows a cross section of another embodiment of the pack for use in the present invention. In Pack 40, the spring shown by reference number 38 in FIG. 4 is replaced by a compressible conductive foam layer whose resistivity depends on the compression of the foam. Such materials are known and are therefore not discussed in detail herein. For the purposes of the present invention, it is sufficient to point out that the resistivity between electrodes 32 and 33 changes with the compression of the foam.

The above embodiments of the present invention have described two discontinuous levels of force that define a level of force in which cursor movement is linked and a level of force at which the click function is achieved. However, it is also possible to introduce devices that are used to measure analog levels of force and perform other functions. For example, an analog level of force can be used to perform the function of a pressure sensitive drawing device. Graphic input devices that take advantage of that type of functionality are well known in the art and are therefore not discussed in detail herein. For the purposes of this theory, it is only pointed out that the pressure on the surface to which the pointing device is applied is converted to some attribute of the figure, such as the width of the line currently drawn at the cursor position on the display. Is enough.

An embodiment of a position detector that detects the position of the pack on the underlying surface can be more easily understood by referring to FIG. FIG. 7 is a plan view of the portion of the surface 12 shown in FIG. 1 in which the pack moves on the embodiment of the present invention. Surface 50 includes four electrodes, reference numbers 51-54, having terminals connected to an external circuit. These terminals are omitted for the sake of simplicity in the drawing. The pack has a bottom surface that includes an electrode 55, which is shown by the dotted line in the figure. Electrodes 51-55 are electrically isolated from others. For example, the electrode 55 is covered with a dielectric layer that provides the required insulation as the electrode 55 slides over the other electrodes. In short, the electrodes are patterned on the back side of the substrate on the surface indicated by reference numeral 50. This reduces the capacitance between the electrodes and the pack electrode, but is practical for substrates with a thickness of a few millimeters or less. The overlap between the electrodes 55 and each electrode 51-54 depends on the position of the pack with respect to the electrodes 51-54. The overlap between electrodes 55 and 51-54 is indicated by AD, respectively.

See further FIG. 8, which is a schematic diagram of an equivalent circuit for electrodes 51-55. The portion of the electrode 55 that overlaps the electrode 51 forms a parallel plate capacitor having a capacitance proportional to the overlap A. Similarly, the portion of the electrode 55 that overlaps with the electrode 52 forms a parallel plate capacitor having a capacitance proportional to the overlap B, and so on. Since all of the capacitors share the portion of electrode 55, the equivalent circuit consists of four capacitors connected to the common electrode indicated by reference numeral 58. This electrode is exactly the electrode 55. Therefore, the position of the electrode 55 with respect to the electrode 51-54 can be defined by measuring the capacitance between the electrode 55 and each electrode 51-54. This demarcation is made by the controller 159, which is part of the pointing device, or part of the host device from which the pointing device forms that part.

In embodiments where the pack operating area is substantially larger than the diameter of the pack, more than four electrodes can be placed on the substrate. A measurement of the capacitance between each of those electrodes and the pack can be used to determine the position of the pack, as described above.

The above embodiment of the position detector has an electrical connection to the electrode 55 at the bottom of the pack. In embodiments where the capacitive coupling between each electrode pair on the surface 50 is measured, this connection can be omitted. That is, the capacitance between the electrodes 51 and 52 is measured separately from the capacitance between the electrodes 51 and 53, and so on. Consider the capacitance between electrodes 51 and 52. The equivalent circuit is C, which is proportional to the overlap A.₁C that overlaps with C and is proportional to C₂It is the same as the circuit shown in FIG. The four measurements between adjacent electrodes provide information for solving each of the four capacitances, thus defining the position of the pack.

The electrode on the bottom of the pack has a circular shape, and it is preferable to reduce the error caused by the shape of the electrode. The restoring spring causes the pack to rotate somewhat. If the user's finger is not in the center of the puck during the movement of the puck, torque will result and the puck will rotate slightly. If the electrodes of the puck are annular and symmetric, such rotation does not change the result of the position measurement. On the other hand, if the electrodes of the puck are not annularly symmetric, the overlap between the puck and the various electrodes will be different for different rotations, even in each case where the center of the puck is in the same position.

In the above embodiment of the present invention, since the influence of dust accumulated on the surface of the electrode or wear on the surface of the pack or the electrode is small and the consumption electrode is very small, the detection of the position is defined as the measurement of capacitance. However, other position detection mechanisms can be used. Further refer to FIG. 9A, which is a plan view of the portion of the surface 12 shown in FIG. 1 in which the pack moves over it in another embodiment of the present invention. Surface 60 includes a single resistance layer with electrodes at its four corners, as indicated by reference numbers 71-74. Pack 62 slides over this layer. Again, the pack is shown with a dotted line. The pack 62 includes an electrode 63 that contacts a very small area of the resistance layer 61. The position of the electrode 63 with respect to the electrodes 71-74 can be defined by measuring the current flowing from the electrodes 71-74 when the current is injected into the electrodes 63.

The position of the pack within the pack operating area can also be confirmed by using an optical sensor as used in a conventional optical mouse. See further FIG. 9B, which illustrates such a detection mechanism. In this embodiment, the bottom surface 84 of the pack 82 includes a pattern or appearance illuminated by an optical mouse sensor 83 located beneath the surface 81 of the pack operating area. Optical mouse sensors are well known in the art and are therefore not discussed in detail herein. For the purposes of this paper, it is sufficient to point out that the optical mouse sensor 83 has a lighting system that illuminates the bottom surface of the pack 82 and an image sensor that forms an image of the illuminated surface portion. The imaging system compares the continuous images of the bottom surface to determine the size and direction in which the puck moves between the images.

Previous examples of suitable position detection mechanisms are provided by way of example. However, from the previous discussion, it is clear that a large number of position measuring mechanisms are available without departing from the art of the present invention.

Many of the above embodiments require that electrical contact be formed in the pack. The pressure sensing mechanism requires two or three connections, depending on the particular embodiment implemented. The position detector requires an additional connection. See again FIG. 1 in which the springs designated by reference numeral 13 are utilized for their connection in a preferred embodiment of the present invention. In such an embodiment, the springs are made from an electrically conductive material or coated with an electrically conductive material, so that each spring provides an electrical connection to the pack.

The above embodiment of the present invention utilizes an electrical connection made to the pack via a spring. However, methods are available to detect signals associated with the pack that do not require a direct connection to the pack. Techniques for remote measurement are known in RF identification sheet techniques and are not discussed in detail herein. For the purposes of this theory, it is sufficient to point out that the values of capacitors and inductors in remote devices can detect the absorption of the device from RF signals by measuring the output. For example, consider an embodiment in which the pressure applied to the pack is detected via a change in volume, as described above. Capacitors whose capacitance is measured can be incorporated into tank circuitry where the resonance frequency is detected by measuring the output absorbed by the pack as a function of the frequency from the RF antenna located at the base of the pointing device. it can.

In the above embodiment of the present invention, when the pressure applied to the puck is greater than the activation threshold level, the coupling between the cursor and the puck on the display is activated and the pressure is lower than the activation threshold level. , The bond is released. If the pressure is completely released, the puck is returned to its center position by the spring described above.

The distance the cursor is moved can be greater than the maximum distance that can be moved by moving the puck from its stationary position in the center of the puck operating area to the boundaries of the puck operating area. In this case, the user is required to recenter the pack in the same way as using a conventional mouse: release the pack and then re-engage the pack by placing a finger on the pack. You can move the cursor. The cursor is released when the finger is removed prior to recentering the puck, allowing the user to resume moving the cursor on the display from the position on the display where the user's finger was removed from the puck. .. This approach provides a satisfactory solution for most cursor movements, but can require very large movements. In such cases, achieving movement through so many small movements is not always satisfactory.

The above embodiment utilizes a meandering spring that repositions the pack when the user releases the pack. Ideally, the springs used to reposition the puck provide a restoring force that recenters the puck without requiring the user to apply a force that fatigues the user's hands. In addition, the force must not change over the puck operating area as the change may prevent the user from accurately positioning the puck. In addition, in embodiments designed for use in laptop computers, handheld devices, and other small applications, both the lateral dimensions of the pointing device and the thickness of the pointing device are important. Therefore, a design that increases the thickness and lateral dimensions of the pointing device is not preferred.

The meandering spring shown in FIG. 1 prevents the puck from reaching all parts of the puck operating area. This is especially true when the puck movement is directed towards a spring mounting position around the puck operating area. Therefore, in order to bring the device to a specific range of the pack operating area, a somewhat larger lateral range is needed to accommodate the unusable space on the surface required for the spring in its pressed state. .. In addition, the forces required to move the pack differ for different areas in terms of the pack operating area. Therefore, the meandering spring design shown in Figure 1 is far from ideal.

Common spiral coil springs have similar problems. In addition, the spring has the desired thickness, which increases the thickness of the pointing device. Therefore, such a spring is also unfavorable.

Further refer to FIG. 10, which is a plan view of the pointing device 70 according to another embodiment of the present invention. The pointing device 70 utilizes a spiral spring design that provides most of the ideal properties described above. Pack 75 is attached to the four spiral members designated by reference numbers 71-74. Each spiral member has one end attached to the pack 75 and the other end attached to a fixed point on the pointing device at a point around the pack operating area 76.

The best spring is a spiral spring that rotates approximately 270 to 360 degrees. That is, the spring connected to the upper part of the puck at the 12 o'clock position indicated by the reference number 79 terminates between 9 o'clock and 12 o'clock at the boundary of the puck operating area indicated by the reference number 77. This is the preferred spring configuration, but other spring configurations can also be used. When using shorter springs, the puck is more likely to rotate if it moves to the limit of the puck operating area. Such rotation interferes with the position detection mechanism in some designs. Springes longer than 360 degrees consume more space available, resulting in weaker restoring force.

The puck design shown in Figure 9A has a dead space adjacent to the boundary of the puck operating area, which is three times the width of the spring. Metallic springs with a width of approximately 0.25 mm are properly implemented. Therefore, a range narrower than 1 mm adjacent to the boundary of the puck operating region is wasted in such a spiral spring based on a pointing device. A plastic spring with a width of 0.75 mm and a thickness of 1.5 mm fits into a pack with a diameter of 30 mm within a working area of 60 mm in diameter.

The embodiment shown in FIG. 10 utilizes a spiral member that is flat for each spring. That is, when the puck is centered in the puck operating region, the curve achieved by the spring is given by R = k-k'θ in the polar coordinate system (R, θ). Here, k and k'are constants. This curve is a good approximation that maximizes the length of the spring, but a curve with a different relationship than this one at the two ends is advantageous. In such springs, the two ends of the swirl are modified to form an end that is approximately in contact with the point where the spring is attached to the boundary of the puck and puck operating area. With such modifications, the puck is more easily reached by the limits of the puck operating area. In addition, it is clear that the exact curve achieved by each flat swirl member can be somewhat different from the perfect swirl shape, still providing considerable benefits over other spring designs. .. Thus, the term "flat spiral member" is defined to include any linear structure having a length L and a centerline, where R is at least 50% of L for any given value of θ. Against R₀A curve is achieved in a polar system (R, θ) such that it is in the range of 25% of = k-K'θ. In addition, other forms of bow springs can be utilized even in springs that do not provide all the advantages of the spiral members described above.

The above-described embodiment of the present invention utilizes four springs to restore the pack to its resting position. However, it is possible to utilize other numbers of springs. In principle, one spring can be utilized, however, the spring is required to provide restoring force in two directions and is therefore no longer isotropic and more rigid than the springs mentioned above. In addition, more springs can be utilized to provide an additional electrical connection to the pack.

The spring in the above embodiment ideally returns the pack to a stationary position in the center of the operating area. Such an embodiment maximizes the amount of movement adapted from the stationary position. However, it is clear from the previous discussion that the puck does not have to be accurately returned to the same starting position each time it is released. Similarly, it is not necessary to return the puck to a stationary position that is closely aligned with the center of the puck operating area. The present invention meanders as long as the puck can be moved from that position to a new position in any desired direction by returning the puck to a position sufficiently close to the center of the puck operating area. Brings improvements beyond spring design.

Note that it is preferable for the puck to return to its resting position with as little vibration as possible. Therefore, it is preferable to include some form of damping vibration. One way to dampen the vibration is to ensure that the puck is pressed against the underlying surface as it is released by the user and returns to its resting position. In this case, the friction between the pack and the underlying surface provides damping force. This is achieved by attaching a spring to the pack that applies a downward force. For example, the mounting position of the pack with respect to the end of the spring can be placed at a greater distance from the operating surface than the mounting position of the pack with respect to the other end of the spring. Alternatively, the springs can be deformed so that each spring exerts a downward force in addition to the restoring force described above.

The above embodiment of the present invention utilizes a spring that returns the pack to its stationary position when the user releases the pack. However, other mechanisms for restoring the pack to its resting position when released by the user are also available. For example, the pack includes magnets that are attracted to the corresponding magnets in the substrate below the pack. Such an embodiment is shown in FIG. 11 showing a cross section of yet another embodiment of the pointing device of the present invention. The pointer 90 includes a pack 91 similar to the pack above, which includes a pressure detection mechanism in which the pack defines a pressure threshold. The pointer 90 also includes an electrode at the bottom of the pack, on which the position of the pack with respect to the electrode on the substrate 93 on which the pack moves is measured. Exemplified substrate electrodes are shown with reference numbers 94 and 95. The pack 91 also includes a magnet 96 that provides both a restoring force to return the pack to its resting position when the pack is released by the user and an electrode structure for measuring the position of the pack. The corresponding magnet 97 is included in the substrate 93. The poles of the magnet 97 are arranged to oppose the poles of the magnet 96. The magnetic field of the magnet has a maximum value at the center of the magnet shown in FIG. 10 and is selected to weaken with distance from the center of the magnet. Thus, when the puck is released, the puck is returned to a stationary position where the magnets are centered above the other. It should be noted that when the magnet provides the downward damping force described above and the puck is released, some vibration of the puck is reduced near its resting position.

The above embodiment of the present invention utilizes the force exerted by the user's finger to activate the binding of the movement of the pack to the movement of the cursor on the display. However, other mechanisms can be used to signal the cursor coupling. For example, the capacity can be detected by placing the user's finger on the pack. Such sensors are known and will not be discussed in detail herein. It is sufficient to point out that placing the user's finger changes the capacitance of one or more electrodes on the pack measurable.

User sensors are also performed by software analysis of the pack's x and y positions by the controller, rather than a separate force or capacitance sensor. When the puck is rapidly returned to the center under the force of the recentering spring, the direction and acceleration of the puck's movement determines whether the puck was operated by the user or is just under the influence of the spring. To.

The above embodiment of the present invention utilizes some sort of restoration mechanism that returns the pack to its resting position when the user releases pressure on the pack. However, embodiments of the present invention in which the restoration mechanism is the finger of the user can also be configured. In such an embodiment, the user reduces the pressure on the puck to a level below the level at which the puck is bound to the cursor. In addition, the user manually moves the puck to a new position without interlocking with the cursor on the display. In addition, the user continues to move the cursor by pressing again on the puck with sufficient pressure to activate the puck-cursor coupling.

The above embodiment of the present invention refers to a pack that is returned to a predetermined resting position by a restoring mechanism when the user releases the pack. As mentioned above, certain embodiments include some damping force to minimize the time required to eliminate vibrations in the position of the pack after the pack has been released. As a result, the puck is not always accurately returned to the starting position. However, such an accurate restoration is not necessary. Embodiments that generally return the pack to a given starting area are also satisfactorily implemented. Any starting area that is sufficiently far from the boundaries of the pack operating area is satisfactorily implemented.

The above embodiment of the present invention utilizes a circular pack operating region, but other shaped pack operating regions are also possible. For example, the pack operating area can be elliptical or rectangular. In these cases, the optimum spring shape is different from that described above.

Various modifications of the present invention will be apparent to those skilled in the art from the above detailed description and accompanying drawings. Therefore, the present invention is limited only by the description of the appended claims.

<figref num="1A">It is a top view of the pointing device 10.</figref><figref num="1B">It is sectional drawing of the pointing device 10 along the line 1B-1B shown in FIG. 1A.</figref><figref num="2A">It is a figure which illustrates the control of the cursor on the display 100 by the said pack.</figref><figref num="2B">It is a figure which illustrates the control of the cursor on the display 100 by the said pack.</figref><figref num="3">It is a figure which shows the more detailed cross section of the pack of this invention.</figref><figref num="4">It is sectional drawing which shows the other embodiment of the pack for use in the pointing device of this invention.</figref><figref num="5">It is a figure which illustrates the equivalent circuit formed by the electrode shown in FIG.</figref><figref num="6">It is sectional drawing which shows the other embodiment of the pack for use in this invention.</figref><figref num="7">FIG. 5 is a plan view showing a portion of the surface 12 shown in FIG. 1 in which a pack moves over the pack in one embodiment of the present invention.</figref><figref num="8">It is a figure which shows schematic the equivalent circuit with respect to the electrode 51-55 shown in FIG. ..</figref><figref num="9A">FIG. 5 is a plan view showing a portion of the surface 12 shown in FIG. 1 in which the pack moves on the other embodiment of the present invention.</figref><figref num="9B">It is a figure which illustrates one Embodiment of this invention which uses the optical sensor for measuring the position of a pack.</figref><figref num="10">It is a top view of the pointing device 70 according to another embodiment of this invention.</figref><figref num="11">It is sectional drawing of still another embodiment of the pointing device of this invention.</figref>