JP2001296965A - Coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coordinate input device suitable for miniaturization as a pointing device for controlling the position of a cursor. SOLUTION: A columnar body 1 is erected integrally on a tabular pedestal 6 to make a substrate, distortion gages (detection sensors) 3 are adhered and fixed respectively to the four outside surfaces of the cylinder 1 and the respective gages 3 are coated with overcoat layers (protective layers) to constitute the pointing device. Then, the pointing device constituted like this is fixed to the inside of a keyboard input device and when an operator inclines the upper end of the cylinder 1 projecting into respective key tops, a distortion value is outputted from each detection sensor in accordance with its tilt angle and a control part controls the position of the cursor on the display in an optional direction based on these output signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a coordinate input device as a pointing device for controlling the position of a cursor.

[0002]

2. Description of the Related Art In general, a pointing device such as a mouse or a trackball is installed as a separate component from a keyboard input device in a graphic display device or the like. In this case, a dedicated installation space for the pointing device is required. However, there is a disadvantage that the installation area of the entire graphic display device is unnecessarily large.

Therefore, a keyboard input device in which a number of key switches are arranged, a trackball as a pointing device is incorporated, and both are integrated,
It has been conventionally proposed in Japanese Patent Application Laid-Open No. 4-148408. The keyboard input device integrated with the pointing device as described above has an advantage that it can be easily carried in addition to an advantage that the installation area can be reduced, and is used in a field where miniaturization of a portable personal computer or the like is essential. Demand tends to increase.

[0004]

By the way, the above-mentioned conventional keyboard input device integrated with a pointing device incorporates components of a track ball such as a ball and an encoder in a key switch, and the ball is placed on the top surface of the key switch. Since it is rotatably exposed from the surface, the miniaturization of the trackball is naturally limited in consideration of the operability of the ball, and there is room for improvement in miniaturization. In addition, since the arrangement of the input key switch group is standardized, the key switch with a built-in pointing device must be arranged beside the input key switch group, and each key switch is hit. For the operator (operator), it is necessary to move the fingertip from the home position to the lateral direction every time the pointing device is used, and there is also a problem that the operator tends to be tired.

[0005] The present invention has been made in view of such a situation of the prior art, and an object of the present invention is to provide a coordinate input device suitable for miniaturization.

[0006]

In order to achieve the above object, in a coordinate input device according to the present invention, a base on which a columnar body is integrally erected on a base, and a base provided on the base. A plurality of detection sensors and an output unit for outputting detection signals from the detection sensors are provided, and the detection sensors are covered with a protective film.

In the coordinate input device configured as described above,
When a detection signal is output from each detection sensor according to the tilt angle of the columnar body, the cursor position on the display can be controlled in an arbitrary direction based on the output signal, and each detection sensor is protected by a protective film. Because it is covered, each detection sensor can be protected from humidity, dust, and the like, and thus a coordinate input device suitable for miniaturization can be provided.

In the above structure, when the Young's modulus of the protective film after curing is set to be smaller than the Young's modulus of the base, the variation of the initial resistance value and the resistance change before and after the application of the protective film is reduced. Since both are kept low, it is possible to prevent the protective film from adversely affecting each detection sensor. In particular, when a soft UV-curable adhesive is used as the protective film, the curing time after application is significantly reduced. Therefore, workability is also improved.

[0009]

FIG. 1 is a perspective view of a pointing device according to a first embodiment, and FIG. 2 is an exploded perspective view of the pointing device. 3 is a sectional view of the pointing device, FIG. 4 is a front view of a base provided in the pointing device of FIG. 1, FIG. 5 is a plan view of the base, FIG.
7 is a bottom view of the base, FIG. 7 is a sectional view taken along line AA of FIG. 5, FIG.
FIG. 9 is a bottom view of a cap provided in the pointing device of FIG. 1, FIG. 9 is a sectional view taken along line BB of FIG. 8, and FIG.
FIG. 2 is a plan view of a keyboard input device provided with the pointing device of FIG.

As shown in FIGS. 1 to 3, the pointing device according to the present embodiment comprises a base 2 having a columnar body 1 and four detection sensors affixed to side surfaces of the columnar body 1. , A flexible cable 4 connected to each strain gauge 3, and a cap 5 attached to an upper end of the columnar body 1.
Are fixed on a metal plate described later.

As shown in FIGS. 4 to 7, the base 2 is
It has a flat pedestal 6 and the columnar body 1 erected at the center of the pedestal 6, and these columnar body 1 and pedestal 6 are integrally formed using a synthetic resin such as polyphenylene ether (PPE). I have. The columnar body 1 has a quadrangular pyramid shape, and its four outer surfaces are tapered so as to taper upward from the pedestal 6, and the lower part of each outer surface is used to position the strain gauge 3. Is formed. Further, a hollow portion 7 having four vertical walls is formed inside the columnar body 1 so that the thickness of the columnar body 1 is largest on the pedestal 6 side by this hollow portion 7 and becomes gradually thinner upward. Is set to As described above, the thickness of the columnar body 1 is gradually increased downward, and the sectional modulus Z of the columnar body 1 is set so as to gradually increase downward. Therefore, when the upper end of the columnar body 1 is pressed. Outer skin stress σ
= M / Z (M is bending moment) is uniformed in each part,
It is possible to reduce a decrease in detection accuracy due to a variation in the position where the strain gauge 3 is attached. On the other hand, recesses 6a are formed at three places on the upper surface of the pedestal 6, and projections 6b are formed at three places on the back surface of the pedestal 6 corresponding to each recess 6a. The lower surfaces of the protrusions 6b are in the same virtual plane, and the recesses 6a and the protrusions 6b are set at the same distance from the axis passing through the center of the columnar body 1, respectively.

The cap 5 is made of a soft material such as silicone rubber. As shown in FIGS. 8 and 9, the cap 5 has an insertion hole 8 for being attached to the upper end of the columnar body 1. ing. A notch 5a as a chamfer is formed on the inner peripheral edge at the lower end of the insertion hole 8, and the outer surface of the columnar body 1, the cap 5, and the inner surface come into contact at an obtuse angle by the notch 5a. .

Returning to FIGS. 1 to 3, the strain gauges 3 are attached to the outer surfaces of the columnar body 1 using an adhesive, but as described above, each strain gauge 3 has a rib 1a. Affixed as positioning reference. The flexible cable 4 is extended on the upper surface of the pedestal 6 by inserting a through hole 4a into the columnar body 1. The flexible cable 4 and each of the strain gauges 3 are made of solder, conductive adhesive, or the like. Connected using Therefore, when the operator presses the cap 5 in an arbitrary direction with his / her finger, the columnar body 1 is tilted in accordance with the pressing force, and according to the pressing force from each of the strain gauges 3 attached to each outer surface of the columnar body 1. The respective distortion values are output. Note that an overcoat layer 9 described later is applied to the entire strain gauges 3 and the connection between the flexible cable 4 and the strain gauges 3 so as to be protected from humidity, dust and the like.

The adhesive for attaching the strain gauge 3 to the outer surface of the columnar body 1 must be selected in consideration of compatibility with the material of the base 2 and workability.

The overcoat layer 9 needs to be selected in consideration of the influence on the strain gauge 3 and workability. Therefore, a soft type U is used as the overcoat layer 9.
V-curing type (hardness after curing JIS-A20, Young's modulus =
0.2 kgf / cm ² ), hard type UV curing type (hardness after curing JIS-D50, Young's modulus = 300 kgf /
cm ² ), room temperature curing type (hardness after curing JIS-A24,
An evaluation test was performed on these three types of overcoat layers using Young's modulus = 0.2 kgf / cm ² ). The material of the base 2 used was polyphenylene ether (Young's modulus = 257 kgf / cm ² ), the adhesive was a one-part epoxy thermosetting type, and the test contents were as follows: before and after applying the overcoat layer. Resistance value R ₀ variation 2 before and after application of overcoat layer
Item. FIGS. 11 and 12 are explanatory diagrams showing the results of this evaluation test. As is clear from these figures, the hard UV-curable overcoat layer has an initial resistance value R ₀ and a resistance change amount ΔR. It was found that the fluctuation amount was large and had an adverse effect on the strain gauge 3. This is because the Young's modulus of the hard UV-curable overcoat layer is 30% while the Young's modulus of PPE, which is the material of the base 2 (the columnar body 1), is 257 kgf / cm ^2.
This is considered to be 0 kgf / cm ^2, which is higher than the base 2. Further, the soft type UV-curable overcoat layer and the room temperature-curable overcoat layer exhibit almost the same fluctuation characteristics in both the initial resistance value R ₀ and the resistance change ΔR, but are compared with the room temperature-curable type. Since the curing time of the UV-curable type is extremely short, it has been found that the most suitable overcoat layer is a soft type UV-curable type in consideration of workability.

In the pointing device configured as described above, the base 2 is mounted on the metal plate 10 via the membrane sheet substrate 11 and the metal plate 1
The three support pieces 10a cut and raised to zero are fixed in the respective recesses 6a of the pedestal 6 by bending them. At this time, the base 2 is supported at three points by three projections 6b formed on the back surface of the base 6, so that the smoothness of the mounting surface is maintained with high accuracy. The metal plate 10 and the membrane sheet substrate 11 are arranged inside the keyboard input device shown in FIG. 10, and a large number of key switches 12 are mounted on the metal plate 10 and the membrane sheet substrate 11. The key top of each key switch 12 and the cap 5 of the pointing device are exposed from the top surface of the housing 13 forming the outer shell of the keyboard input device and slightly protrude from the key top. F, J
Are exposed so as to be surrounded by the key tops of three keys G, H, and B located in the middle of the space key 12a, specifically, right above the space key 12a. With this arrangement, it is possible to operate the pointing device with the left and right forefinger while operating with other fingers, thereby improving operability.

FIG. 13 is a block diagram showing an arithmetic processing portion of the pointing device. As shown in FIG. 13, signals output from the respective strain gauges 3 are input to a control unit 14 via a flexible cable 4. , This control unit 14
After calculating the moving direction, the moving amount, and the moving speed of the cursor, the moving data is transmitted to the host 15 side.
The control unit 14 has an interface with the mouse 16 so that a mouse 16 as another pointing device can be connected.

FIG. 14 is a block diagram of the control unit 14. As shown in FIG.
An A / D converter 18, a CPU 19, and a D / A converter 20 are provided. In the present embodiment, two strain gauges 3 facing each other in the X-axis direction and the Y-axis direction among the four strain gauges 3 described above are set as one set, and for example, the strain gauges 3 (Y +, Y The voltage obtained from −) is divided and output to the operational amplifier 17. The operational amplifier 17 increases / subtracts the voltage V ₁ and the correction value V ₂ sent from the CPU 19 via the D / A converter 20 to remove the variation of each strain gauge 3 itself, and then outputs the output voltage V ₃ To the CPU 19 via the A / D converter 18. Similarly, the divided voltage obtained from the pair of strain gauges 3 (X +, X−) in the X-axis direction is also sent to the CPU 19 after the operational amplifier 17 removes the variation of each strain gauge 3 itself. . The CPU 19 is based on the output voltage V ₃ obtained from each of the strain gauges 3 in the X-axis direction and the Y-axis direction and a table showing a relationship between stress (gf) and strain value (μm / m) of the strain gauge 3. Then, the movement direction, movement amount and movement speed of the cursor are calculated, and the movement data is transmitted to the host 15 side.

Next, the operation of the above embodiment will be described.
In the keyboard input device shown in FIG. 10, when an operator presses the cap 5 in an arbitrary direction with a finger, the columnar body 1 is tilted in accordance with the pressing force, and each strain adhered to each outer surface of the columnar body 1 is displaced. A strain value proportional to the pressing force is output from the gauge 3 as a change in resistance value. At this time, since the columnar body 1 has a hollow structure, the columnar body 1 is easily deformed.
Are tapered so as to become gradually thicker toward the pedestal 6 side, so that the stress acting on the strain gauge 3 has less variation and a stable resistance value is output. Further, a notch 5a is formed in the inner peripheral edge of the lower end of the cap 5.
Is formed, and the outer surface of the columnar body 1 and the inner side surface of the cap 5 come into contact with each other at an obtuse angle, so that stress concentration at the contact portion can be avoided and the contact area between the columnar body 1 and the cap 5 decreases. The columnar body 1 can be deformed without displacement with respect to the cap 5, and a stable resistance value is output from this point as well.

The resistance value output from each strain gauge 3 in this manner is input to the control unit 14 via the flexible cable 4 and, as described above, the control unit 14 converts the output value from each strain gauge 3 into an output value. After the moving direction, the moving amount, and the moving speed of the cursor are calculated based on the calculated data, the moving data is transmitted to the host 15. Thus, in the graphic display device not shown, the cursor is moved in accordance with the pressing force on the cap 5, and for example, when the cap 5 is slowly pressed in an arbitrary direction, the cursor is also slowly moved in the same direction.

FIG. 15 is a cross-sectional view of a main part showing a mounting state of the pointing device according to the second embodiment. FIG. 16 is a plan view of a base provided in the pointing device. Corresponding parts are denoted by the same reference numerals.

As shown in these figures, in the present embodiment, three mounting holes 6c are provided on the pedestal 6 of the base 2 at equal distances from the center line of the columnar body 1, and the metal plate 10 Three bosses 10b extending downward through the membrane sheet substrate 11 are vertically provided, and the screws 21 are fixed in a state where the upper surface of each mounting hole 6c is abutted against the lower surface of the boss 10b.
The base 2 is fixed to the metal plate 10 using. With this configuration, a part of the pointing device is disposed in the space below the metal plate 10, so that the height of the columnar body 1 and the cap 5 protruding above the metal plate 10 can be reduced. This is advantageous for reducing the thickness of the keyboard input device.

The present invention can be modified in various ways other than the embodiment described above. For example, the shape of the columnar body 1 is not limited to a quadrangular pyramid. Each strain gauge 3 may be adhered to the peripheral surface. Also,
The position where each of the strain gauges 3 is attached is not limited to the outer surface of the columnar body 1, but may be attached to the inner wall of the hollow portion 7 of the columnar body 1 as shown in FIG. Each strain gauge 3
Has the additional effect of protecting the device from external factors such as static electricity and humidity. Furthermore, the number of each strain gauge 3 is not limited to four, and it is essential that at least two strain gauges 3 be provided so that deformation of the X-axis component and the Y-axis component of the columnar body 1 can be detected. . Furthermore, the thickness of the columnar body 1 may be gradually increased downward by forming the hollow portion inside the columnar body 1 in a tapered shape.

[0024]

The present invention is embodied in the form described above and has the following effects.

The pedestal is provided with a base on which a columnar body is erected integrally, a plurality of detection sensors provided on the base, and an output section for outputting detection signals from these detection sensors. Therefore, when a detection signal is output from each detection sensor according to the tilt angle of the columnar body, the cursor position on the display can be controlled in an arbitrary direction based on these output signals. Is covered with a protective film, so that each detection sensor can be protected from humidity, dust, and the like, and thus a coordinate input device suitable for miniaturization can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a pointing device according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the pointing device.

FIG. 3 is a sectional view of the pointing device.

FIG. 4 is a front view of a base provided in the pointing device of FIG. 1;

FIG. 5 is a plan view of the base.

FIG. 6 is a bottom view of the base.

FIG. 7 is a sectional view taken along line AA of FIG. 5;

FIG. 8 is a bottom view of a cap provided in the pointing device of FIG. 1;

FIG. 9 is a sectional view taken along line BB of FIG. 8;

FIG. 10 is a plan view of a keyboard input device provided with the pointing device of FIG. 1;

FIG. 11 is an explanatory diagram showing the results of an initial resistance value variation test of an overcoat layer.

FIG. 12 is an explanatory diagram showing the results of a resistance change amount variation test of the overcoat layer.

FIG. 13 is a configuration diagram illustrating an arithmetic processing portion of the pointing device of FIG. 1;

FIG. 14 is a block diagram of a control unit provided in the arithmetic processing unit of FIG.

FIG. 15 is a cross-sectional view of a main part showing a mounting state of a pointing device according to a second embodiment of the present invention.

FIG. 16 is a plan view of a base provided in the pointing device.

FIG. 17 is a plan view showing a modification of the columnar body.

FIG. 18 is a sectional view showing a modification of the pointing device.

[Explanation of symbols]

 Reference Signs List 1 columnar body 1a rib 2 base 3 strain gauge 4 flexible cable 5 cap 5a notch 6 pedestal 6a recess 6b protrusion 6c mounting hole 7 hollow portion 8 insertion hole 9 overcoat layer (protective layer) 10 metal plate 10a support piece 10b Boss 11 Membrane sheet substrate 12 Key switch 13 Housing 14 Control unit 15 Host 17 Operational amplifier 18 A / D converter 19 CPU 20 D / A converter 21 Screw

Claims (3)

[Claims] 1. A base on which a columnar body is erected integrally with a base, a plurality of detection sensors provided on the base,
An output unit for outputting detection signals from the detection sensors, wherein the detection sensors are covered with a protective film. 2. The coordinate input device according to claim 1, wherein the cured Young's modulus of the protective film is set smaller than the Young's modulus of the base. 3. The coordinate input device according to claim 2, wherein a soft UV-curable adhesive is used as the protective film.