JP2824162B2 - Coordinate input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device such as a tablet used for inputting characters or figures into a computer or a word processor, and more particularly to a coordinate input device in which two sheet resistance sheets are opposed to each other. A so-called pressure-sensitive tablet that presses an arbitrary point on one sheet resistance sheet serving as an input surface with a finger or a pen to contact the other sheet resistance sheet, and detects and outputs coordinates of the contact point. A coordinate input device.

[0002]

2. Description of the Related Art Heretofore, for example, a pressure-sensitive tablet has been used as a means for inputting characters, figures, and the like to a computer or a word processor. Pressure-sensitive tablets are widely used because of their simple structure, low power consumption, and low cost compared to other types of tablets.

FIG. 11 is a cross-sectional view showing the structure of a conventional pressure-sensitive tablet 10. As shown in FIG. Pressure-sensitive tablet 10
As shown in FIG. 11A, a flexible polyester film 1 in which one conductive film (sheet resistance) 2 is formed over one entire surface, and one The glass substrate 3 on which one conductive film (sheet resistance) 4 is formed is disposed so that the conductive films 2 and 4 face each other.
The spacers 5 are interposed between the conductive films 2 and 4 to keep the insulation between the conductive films 4 and the distance between the conductive films 2 and 4 constant. FIG.
As shown in (2), a desired area between the spacers 5 is pressed by pressing means 6 such as a finger or a pen to bring the conductive films 2 and 4 into contact, and the coordinates of the contact point are detected and output.

FIG. 12 is a cross-sectional view showing the structure of another conventional pressure-sensitive tablet 11. As shown in FIG. This tablet 1
1 is similar to the tablet 10 shown in FIG. 11 described above, and the corresponding components are denoted by the same reference numerals and described.
In the tablet 11 shown in FIG. 12, the spacer 5 is provided only for maintaining insulation between the conductive films 2 and 4, and the distance between the conductive films 2 and 4 is kept uniform by another distance adjusting member. I have. That is, the tablet 11 shown in FIG.
The spacer 5 is provided only to prevent the conductive films 2 and 4 from coming into contact with each other in a region around the pressing region when the desired region is pressed by the pressing means 6.

As shown in FIG. 12 (2), the desired area between the spacers 5 is pressed by the pressing means 6 to bring the conductive films 2 and 4 into contact with each other, as shown in FIG. Detect and output coordinates.

[0006]

Generally, the input sensitivity of a pressure-sensitive tablet, that is, the pressure required for the upper and lower conductive films 2 and 4 to come into contact with each other depends on the height and spacing of the spacers 5 and the polyester film used as the pressing surface. 1 and the curvature of the leading end of the pressing means 6. Normally, the spacers 5 are arranged at uniform intervals as shown in FIG. 13, that is, at a uniform installation density so that input can be performed even with relatively light pressure.

However, as the size of the pressure-sensitive tablet increases, when a target position is to be input (pressed) by the pressing means 6 such as a finger or a pen, FIG.
As shown in FIG.
Touch the pressing surface of the pressure-sensitive tablet. As a result, the conductive films 2 and 4 come into contact with each other at a position other than the desired input position, which causes an erroneous input.

FIG. 15 is a circuit diagram showing the electrical configuration of the pressure-sensitive tablet, showing a state where the conductive films 2 and 4 are in contact at two places at the same time. Terminals XLa, XHa; YLa, YH are provided at opposite ends of the conductive films 2, 4, respectively.
a is provided. The sheet resistance of the conductive films 2 and 4 is Rxa between the terminals XLa and XHa and R between the terminals YLa and YHa.
ya, usually a resistance value of several hundred Ω.

When the pressing means 6 such as a pressure-sensitive pen is not in contact with the upper surface of the polyester film 1 on which the conductive film 2 is formed, as shown in FIGS. The conductive films 2 and 4 are slightly separated from each other via the spacer 5 and the like, and the conductive films 2 and 4 are electrically in a non-contact state.

The terminals XLa, XHa; YLa, YHa
Includes switching elements SXLa and SXHa;
SYLa and SYHa are connected, and by controlling these switching elements, terminals XLa and YL are connected.
a can be switched to a low level (ground potential) or a high impedance state, and the terminals XHa and YHa can be switched to a high level (potential Vc) or a high impedance state.

Therefore, it is possible to bring both the terminals XLa and XHa into a high impedance state so that the conductive film 2 is in a high impedance state. It is also possible to have a potential, and this is the same for the conductive film 4.

Here, referring to FIG. 15, one point on the polyester film 1 is pressed by the pressing means 6 to
4 illustrates a case where point contact is made at the contact point Pa. In this case, the switching elements SXLa and SXHa are both turned on, the terminal XLa is set to a low level (ground potential), the terminal XHa is set to a high level (potential Vc), and the switching elements SYLa and SYHa are both turned off to set the conductive film 4 high. In the state of impedance, the terminal Y
The potential of La becomes the potential of the contact point Pa. This contact point Pa
Is a potential for dividing the potential Vc into Rx1: Rx2, and the X coordinate can be calculated based on this potential. Further, by setting the setting state of the switching element in the opposite manner as described above, the Y coordinate can be calculated.

The potentials at the terminals XLa and YLa are converted into digital data by an A / D converter 8 having a high input impedance and supplied to a CPU (Central Processing Unit) 9. The CPU 9 calculates the X coordinate and the Y coordinate of the contact point Pa based on the provided digital data.

At this time, for example, as shown in FIG.
When an input is made with the pressing means 6 such as a detection pen or a finger, the palm 7 or the like may come into contact with the polyester film 1 and the conductive films 2 and 4 may come into contact at two places. In this case, as shown in FIG. 15, the resistance between the contact point Pa by the pressing means 6 and the contact point Qa by the palm 7 or the like becomes the parallel resistance of the resistance Rx21 by the conductive film 2 and the resistance Ry21 by the conductive film 4. Therefore, the resistance between the terminals XLa-XHa and the terminals YLa-YHa is equal to the normal resistance R
The value becomes lower than x and Ry, and there is a problem that a position completely different from the original contact point Pa is detected as input coordinates.

An object of the present invention is to provide a coordinate input device which prevents erroneous input and has good usability.

[0016]

According to the present invention, a pair of sheet resistance sheets having electrodes at opposite ends are held with spacers interposed therebetween to keep the distance between the sheets uniform. Arranged so as to be orthogonal to each other, and to be in contact with each other when an arbitrary point on one sheet resistance sheet is pressed, and for each sheet resistance sheet, one electrode and the other electrode are respectively provided. A switching means connected to a high level and a low level via a switching means to control the switching means so that one of the pair of sheet resistance sheets has an inclined potential and a switching means connected to the other sheet resistance sheet. In the high impedance state, the potential of the sheet resistance sheet on the switching means side in the high impedance state is detected, and coordinates of a point pressed based on the detected potential are calculated. In the coordinate input device so as to output a coordinate input apparatus characterized by thicker than the sheet thickness of the other regions of the sheet thickness of the particular region in which predetermined on the surface resistance sheet.

Further, according to the present invention, a pair of sheet resistance sheets having electrodes at opposite ends are held with spacers interposed therebetween to keep the distance between the sheets uniform, so that the electrode forming directions are orthogonal to each other. And, when an arbitrary point on one sheet resistance sheet is pressed, they are arranged to be in contact with each other, and one electrode and the other electrode of each sheet resistance sheet are respectively connected via switching means. Connected to a high level and a low level to control the switching means so that one of the pair of sheet resistance sheets has an inclined potential, and set the switching means connected to the other sheet resistance sheet to a high impedance state, The potential of the sheet resistance sheet on the switching means side in the high impedance state is detected, and coordinates of a pressed point are calculated based on the detected potential. In the coordinate input device, the size of the spacer in the predetermined specific area on the sheet resistance sheet is made larger than the size of the spacer in the other area, so that the distance between the sheet resistance sheets in the specific area is different. The coordinate input device is characterized in that the coordinate input device is set to be longer than the distance between the sheet resistance sheets in the region (1).

Still further, according to the present invention, a pair of sheet resistance sheets having electrodes at opposite ends are held with spacers interposed therebetween to keep the distance between the sheets uniform, so that the electrode forming directions are orthogonal to each other. And, when an arbitrary point on one sheet resistance sheet is pressed, they are arranged to be in contact with each other, and one electrode and the other electrode are connected to each sheet resistance sheet via switching means. To a high level and a low level to control the switching means so that one of the pair of sheet resistance sheets has an inclined potential, and the switching means connected to the other sheet resistance sheet is set to a high impedance state. Detecting the potential of the sheet resistance sheet on the switching means side in the high impedance state, and calculating coordinates of a pressed point based on the detected potential. In the coordinate input apparatus that,
A coordinate input device, wherein an installation density of the spacers in a predetermined specific area on the sheet resistance sheet is set higher than an installation density of the spacers in another area.

Further, the present invention is characterized in that the predetermined specific region corresponds to a region where an operator's hand contacts when the sheet resistance sheet is pressed.

[0020]

[0021]

According to the present invention, the input sensitivity of the predetermined area on the sheet resistance sheet is set lower than the input sensitivity of the other areas. The input sensitivity means a pressure required for two sheet resistance sheets to come in contact with each other. The predetermined specific region is selected as a region corresponding to a position where an operator's hand or the like contacts when the operator presses the sheet resistance sheet.

Accordingly, in the predetermined specific area, coordinate input cannot be performed unless a large pressure is applied as compared with the other areas. As a result, the sheet resistance sheet comes into contact with the area other than the coordinate to be originally input. Can be prevented. As a result, the occurrence of erroneous input can be reduced, and a highly usable coordinate input device can be provided.

In a so-called pressure-sensitive coordinate input device, the input sensitivity is determined by the distance between the two sheet resistance sheets (the height of the spacer), the thickness of the sheet resistance sheet serving as the input surface (pressing surface), and the pressing means. Is determined by the curvature of the tip of the lens.

When the same pressing means is used and the thickness of the sheet resistance sheet serving as a pressing surface is uniform, the larger the distance between the sheet resistance sheets by increasing the height of the spacer, the greater the pressure when inputting coordinates. is required. Therefore, the input sensitivity of the specific area can be set low by making the height of the spacer in the predetermined specific area larger than the height of the spacer in other areas.

When the same pressing means is used and the height of the spacer is uniform, the greater the thickness of the sheet resistance sheet serving as the pressing surface, the greater the pressure is required at the time of coordinate input. Therefore, by making the thickness of the sheet resistance sheet in the specific area larger than the thickness of the sheet resistance sheet in other areas, the input sensitivity of the specific area can be set low.

Further, when the same pressing means is used and the thickness of the sheet resistance sheet serving as the pressing surface is uniform and the height of the spacer is uniform, the deformation density at the time of pressing is increased by increasing the installation density of the spacer. If you reduce the area to
When inputting coordinates, a large pressure is required. Therefore,
By setting the installation density of the spacers in the specific area higher than the installation density of the spacers in other areas, the input sensitivity of the specific area can be set low.

[0027]

Usually, the coordinate input device employs a pen input method and a touch input method. The pen input method is a method in which input is performed by pressing means having a thin and hard material such as a ballpoint pen. The touch input method is a method in which an input is performed by pressing means having a relatively large curvature and a soft material such as a fingertip. In the pen input method, since the pressing surface is small, an input instruction can be made even with a relatively small pressure. In the touch input method, since the pressing surface is large, a relatively large pressure is required at the time of input.

Therefore, in the coordinate input device in which regions having different input sensitivities are set as described above, a touch input method is used in a region having a high input sensitivity, and a pen input method is used in a region having a low input sensitivity. A highly usable coordinate input device can be provided.

[0030]

FIG. 1 is a plan view of a pressure-sensitive coordinate input device 21 according to one embodiment of the present invention, and FIG. 2 is a perspective view of the pressure-sensitive coordinate input device 21. The coordinate input device 21 has a function selection area 22 and a character input area 23 which are set at both ends in the vertical direction of FIG. 1 and a work area 24 in which coordinates such as coordinates are input by a pen 25 as a pressing means. The function selection area 22 has a low input sensitivity and is a touch input area where an input is made with a fingertip or the like. The character input area 23 has a high input sensitivity and an input with the pen 25 or the like is performed. This is a pen input area to be performed. As shown in FIG. 2, a character input area (pen input area) 23 is arranged near the operator who inputs coordinates.

FIG. 3 is a sectional view of the coordinate input device 21 as viewed from the cutting plane line III-III. Coordinate input device 21
Is a resistance layer (sheet resistance) 3 made of indium oxide or the like.
Sheets 3 formed on surfaces facing each other
1 and 33 are bonded together with a spacer 35 interposed therebetween. The spacer 35 serves to keep the distance between the resistance layers 32 and 34 uniform and to electrically insulate the resistance layers 32 and 34.

The sheet 31 is an input surface pressed by the pen 25, and is made of a flexible material such as polyester or polyethylene. The sheet 33 is a fixed substrate, and is made of glass or polyethylene whose back surface is reinforced with plastic.

As shown in FIG. 3, the sheet thickness tf of the sheet 31 in the pen input area 23 is selected to be longer than the sheet thickness td of the sheet 31 in the touch input area 22.
Generally, in a pressure-sensitive coordinate input device, the input sensitivity is
It is determined by the height of the spacer 35 for adjusting the distance between the first and the third 33, the thickness of the sheet 31 as the input surface, and the curvature of the tip of the pen 25 as the pressing means. Therefore, as shown in FIG. 3, when the spacers 35 having the same size are used, a large pressure is required at the time of coordinate input by increasing the sheet thickness of the sheet 31. That is, the input sensitivity is set low.

Therefore, as shown in FIG.
When the function selection area 22 or the work area 24 is pressed by using, the input sensitivity is set low even if the palm or the finger of the operator touches the pen input area 23, so that the resistance layers 32 and 34 are set. But never touch. Thereby, occurrence of an erroneous input in the coordinate input device 21 can be prevented.

FIG. 4 is a plan view showing a schematic configuration of the coordinate input device 21. In FIG. 4, sheets 31, 33
Are sheets in which uniform resistance layers 32 and 34 are respectively formed on opposing surfaces as described above, and electrodes 31L and 31H;
3H are provided, and terminals XL and XH; YL and YH are connected to these electrodes, respectively. The sheet resistance of the sheets 31 and 33 is Rx between the terminals XL and XH and Ry between the terminals YL and YH, and is usually several hundred Ω.

FIGS. 5 and 6 are circuit diagrams showing the electrical configuration of the coordinate input device 21. When the pen 25 is not in contact with the input surface of the sheet 31, the two sheets 31, 3
3 are spaced apart from each other at predetermined uniform intervals via a spacer 35 or the like, and are electrically separated as shown in FIG.
The two resistance layers 32 and 34 are in a non-contact state.

The terminals XL, XH; YL, YH are respectively provided with switching elements SXL, SXH; SYL, SYH.
Is connected. By controlling these switching elements, the terminals XL and YL are switched to low level (ground potential) or high impedance, and the terminals XH and YH are switched to high level (potential Vc) or high impedance.

Therefore, by setting both the terminals XL and XH to high impedance and setting the resistance layer 32 to the high impedance state, the terminal XL is set to the low level and the terminal XH is set to the high level so that the resistance layer 32 has the inclined potential. This is also possible, and the same applies to the resistance layer 34.

FIG. 6 shows a state where one point on the sheet 31 is pressed by the pen 25, and the resistance layers 32 and 34 of the sheets 31 and 33 are in point contact at the contact point Pi. Therefore, the switching elements SXL and SXH are both turned on, the terminal XL is set to low level (ground potential), and the terminal XH
Is set to a high level (potential Vc) and the switching elements SYL and SYH are both turned off to be in a high impedance state, the potential of the terminal YL becomes the potential of the contact point Pi.

Here, in the resistance layer 32 of the sheet 31, the resistance from the terminal XL to the contact point Pi is Rx1, and the resistance from the contact point Pi to the terminal XH is Rx2. In the resistance layer 34 of the sheet 33, the terminal YL
The resistance from the contact point Pi to the contact point Pi is Ry1, and the contact point Pi
The resistance value from to the terminal YH is Ry2. Accordingly, the potential of the contact point Pi becomes a potential dividing the potential Vc into Rx1: Rx2, and the X coordinate can be calculated by detecting the potential of the terminal YL. Further, by setting the ON / OFF state of the switching element in the opposite manner as described above, the Y coordinate can be calculated in the same manner.

The potentials of the terminals XL and XH are converted into digital data by an A / D converter 26 having a high input impedance and applied to a CPU (central processing unit) 27. The CPU 27 calculates an X coordinate and a Y coordinate based on the detected potentials of the terminals XL and YL.

FIG. 7 is a sectional view showing the structure of a coordinate input device 21a according to another embodiment of the present invention. In this embodiment,
It is similar to the coordinate input device 21 described above, and the same components will be described with the same reference numerals. The feature of the coordinate input device 21a is that the spacer 3 in the pen input area 23
This means that the height hf of 5f is selected to be larger than the height hd of the spacer 35d in the touch input area 22 and the work area 24. Therefore, the distance between the sheets 31 and 33 in the input area 23 is longer than the distance between the sheets in other areas.

By increasing the inter-sheet distance in the pen input area 23 in this manner, the input sensitivity can be set low. This embodiment also has the same effect as the coordinate input device 21 described above.

FIG. 8 is a sectional view showing the structure of a coordinate input device 21b according to still another embodiment of the present invention. This embodiment is similar to the coordinate input devices 21 and 21a described above, and the same components will be described with the same reference numerals. The coordinate input device 21b is characterized in that in the pen input area 23, the sheet thickness tf of the sheet 31 is made larger than the sheet thickness td of the other areas, and the height hf of the spacer 35f is increased.
Is selected to be longer than the height hd of the spacer 35d in the other region. Thereby, the input sensitivity of the pen input area 23 is set lower than the input sensitivity of the other areas.
The coordinate input device 21b according to the present embodiment also has the same effect as the above-described embodiment.

FIG. 9 is a plan view of a coordinate input device 21c according to still another embodiment of the present invention. This embodiment is similar to the coordinate input device 21 described above, and the same components will be described with the same reference numerals. Coordinate input device 21
The characteristic of c is that the spacer 35 in a predetermined specific region is
Is higher than the installation density of the spacers 35 in other regions. In this embodiment, assuming that the operator is right-handed, the installation density of the lower right spacer 35 in the coordinate input device 21c is increased. As a result, the input sensitivity of the specific area is set lower than the input sensitivity of the other areas.

Therefore, when the operator presses the sheet 31 of the coordinate input device 21c, the specific area is selected as an area where a part of the hand other than the finger to be pressed may come into contact with the sheet 31. Even when the palm 28 of the operator touches the sheet 31 as shown in FIG. 10 when the sheet 31 is pressed, it is possible to prevent the resistance layers 32 and 34 from contacting at the contact portion. This embodiment also has the same effect as the coordinate input device 21 described above.

[0047]

As described above, according to the present invention, when the operator presses the sheet resistance sheet, it is possible to prevent the sheet resistances from contacting each other in a region other than the desired pressed region. As a result, the occurrence of erroneous inputs to the coordinate input device can be significantly reduced, and a coordinate input device with good usability and an expanded use range can be realized.

[Brief description of the drawings]

FIG. 1 shows a pressure-sensitive coordinate input device 2 according to an embodiment of the present invention.
1 is a plan view of FIG.

FIG. 2 is a perspective view of a pressure-sensitive coordinate input device 21.

FIG. 3 is a cross-sectional view of the pressure-sensitive coordinate input device 21.

FIG. 4 is a plan view showing a schematic configuration of a coordinate input device 21.

FIG. 5 is a circuit diagram showing an electrical configuration of the coordinate input device 21.

FIG. 6 is a circuit diagram showing a state when coordinates are input in the coordinate input device 21.

FIG. 7 shows a coordinate input device 21a according to another embodiment of the present invention.
FIG.

FIG. 8 is a sectional view of a coordinate input device 21b according to still another embodiment of the present invention.

FIG. 9 is a plan view of a coordinate input device 21c according to still another embodiment of the present invention.

FIG. 10 is a sectional view showing a state when coordinates are input in the coordinate input device 21c.

FIG. 11 is a cross-sectional view illustrating a configuration of a conventional pressure-sensitive tablet 10.

FIG. 12 is a cross-sectional view illustrating a configuration of a pressure-sensitive tablet 11 as another conventional example.

FIG. 13 is a plan view of a conventional pressure-sensitive tablet.

FIG. 14 is a cross-sectional view showing a state when inputting coordinates in a conventional pressure-sensitive tablet.

FIG. 15 is a circuit diagram showing an electrical configuration of a conventional pressure-sensitive tablet.

[Explanation of symbols]

 21, 21a, 21b, 21c Pressure-sensitive coordinate input device 22 Touch input area 23 Pen input area 24 Work area 25 Pen 31, 33 Sheet 32, 34 Resistive layer 35 Spacer

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 3/03

Claims (4)

(57) [Claims] 1. A pair of sheet resistance sheets having electrodes at opposite ends are held with spacers interposed therebetween to keep the distance between the sheets uniform, and the electrode forming directions are orthogonal to each other, and Arranged so as to be in contact with each other when an arbitrary point on one sheet resistance sheet is pressed, and one electrode and the other electrode of each sheet resistance sheet are set to a high level via switching means. Connected to a low level to control the switching means so that one of the pair of sheet resistance sheets has an inclined potential, and the switching means connected to the other sheet resistance sheet is set to a high impedance state, Detecting the potential of the sheet resistance sheet on the switching means side in the state,
In a coordinate input device configured to calculate coordinates of a pressed point based on a detected potential, a sheet thickness of a predetermined specific area on the sheet resistance sheet is made larger than a sheet thickness of another area. Coordinate input device. 2. A pair of sheet resistance sheets having electrodes at opposite ends are held with spacers interposed therebetween to keep the distance between the sheets uniform, and the electrode forming directions are orthogonal to each other, and Arranged so as to be in contact with each other when an arbitrary point on one sheet resistance sheet is pressed, and one electrode and the other electrode of each sheet resistance sheet are set to a high level via switching means. Connected to a low level to control the switching means so that one of the pair of sheet resistance sheets has an inclined potential, and the switching means connected to the other sheet resistance sheet is set to a high impedance state, Detecting the potential of the sheet resistance sheet on the switching means side in the state,
In a coordinate input device configured to calculate coordinates of a pressed point based on a detected potential, the size of the spacer in a predetermined specific area on the sheet resistance sheet is larger than the size of a spacer in another area. A coordinate input device, wherein the distance between the sheet resistance sheets in the specific area is set to be longer than the distance between the sheet resistance sheets in other areas by increasing the distance. 3. A pair of sheet resistance sheets having electrodes at opposite ends are held with spacers interposed therebetween to keep the distance between the sheets uniform, and the electrode forming directions are orthogonal to each other, and Arranged so as to be in contact with each other when an arbitrary point on one sheet resistance sheet is pressed, and one electrode and the other electrode of each sheet resistance sheet are set to a high level via switching means. Connected to a low level to control the switching means so that one of the pair of sheet resistance sheets has an inclined potential, and the switching means connected to the other sheet resistance sheet is set to a high impedance state, Detecting the potential of the sheet resistance sheet on the switching means side in the state,
In a coordinate input device configured to calculate the coordinates of a pressed point based on the detected potential, the installation density of the spacers in a predetermined specific area on the sheet resistance sheet is calculated from the installation density of the spacers in other areas. A coordinate input device characterized by increasing the size of the coordinate input device. 4. The coordinate input device according to claim 1, wherein the predetermined specific area corresponds to an area where an operator's hand contacts when a sheet resistance sheet is pressed.