JPH04337820A - Coordinate input device - Google Patents

Abstract

PURPOSE:To obtain a coordinate input device which prevents erroneous input and has satisfactory usability. CONSTITUTION:The input sensitivity of an area where the palm or the other finger of an operator possibly touches a sheet 31 when the operator inputs the coordinate, namely, when the sheet 31 is pressed is set lower than the input sensitivity of the other area. Input sensitivity denotes pressure required for the contact of the sheets 31 and 33. The input sensitivity of the pressure sensitive coordinate input device is decided by the height of a spacer controlling a distance between the sheets 31 and 33, the thickness of the sheet 31 becoming an input surface and the quality of the sheet 31. Thus, input sensitivity can be set low by heightening the spacer 35 or thickening the sheet 31. Thus, resistance layers 32 and 34 can be prevented from touching in a part except for a desired coordinate input point.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a coordinate input device such as a tablet used for inputting characters, figures, etc. into computers, word processors, etc. More specifically, the present invention relates to a coordinate input device such as a tablet that is used when inputting characters and figures into a computer, word processor, etc. A so-called pressure-sensitive tablet, etc., which detects and outputs the coordinates of the contact point by pressing an arbitrary point on one surface resistance sheet, which serves as an input surface, with a finger or a pen, and bringing it into contact with the other surface resistance sheet. The present invention relates to a coordinate input device.

0002

2. Description of the Related Art Conventionally, pressure-sensitive tablets, for example, have been used as means for inputting characters, figures, etc. into computers, word processors, and the like. Pressure-sensitive tablets are widely used because they have a simpler structure, lower power consumption, and are cheaper than other types of tablets.

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

FIG. 12 is a 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 corresponding components will be described with the same reference numerals. In the tablet 11 shown in FIG. 12, the spacer 5 is provided only to maintain insulation between the conductive films 2 and 4, and the distance between the conductive films 2 and 4 is kept uniform by other distance adjusting members. There is. That is, the tablet 11 shown in FIG.
Here, when the spacer 5 presses a desired area with the pressing means 6, the conductive film 2 is formed in the area around the pressed area.
, 4 are provided only to prevent them from coming into contact with each other.

In this tablet 11 as well, as shown in FIG. 12(2), a 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, and the contact point is Detect and output coordinates.

[0006]

[Problems to be Solved by the Invention] In general, 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, is determined by the height and installation interval of the spacer 5, and the polyester film serving as the pressing surface. 1 and the curvature of the tip of the pressing means 6. Normally, input is possible even with relatively light pressure.
As shown in FIG. 13, the spacers 5 are arranged at uniform intervals, that is, at a uniform installation density.

However, as pressure-sensitive tablets have become larger, when an attempt is made to input (press) a desired position with a pressing means 6 such as a finger or a pen,
As shown in Figure 4, it is inevitable to use the palm 7 on the operator's hand side.
etc. may touch the pressing surface of the pressure-sensitive tablet. This causes the conductive films 2 and 4 to come into contact with each other at a position other than the desired input position, causing erroneous input.

FIG. 15 is a circuit diagram showing the electrical configuration of the pressure-sensitive tablet, and shows a state in which the conductive films 2 and 4 are in contact at two locations 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 values of the conductive films 2 and 4 are Rxa between terminals XLa and XHa, and Rxa between terminals YLa and YHa.
ya, and usually has a resistance value of several hundred ohms.

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 FIG. 11 (1) and FIG. 12 (1), the conductive film 2 and 4 are slightly separated via a spacer 5 or the like, and the conductive films 2 and 4 are electrically in a non-contact state.

[0010] The terminals XLa, XHa; YLa, YHa
are respectively switching elements SXLa, SXHa;
SYLa and SYHa are connected, and by controlling these switching elements, terminals XLa and YL
a can be switched to a low level (ground potential) or a high impedance state, and terminals XHa and YHa can be switched to a high level (potential Vc) or a high impedance state.

Therefore, it is possible to set the conductive film 2 to a high impedance state by setting both the terminals XLa and XHa to high impedance, or by setting the terminal XLa to a low level and the terminal It is also possible to provide a potential, and this also applies to the conductive film 4.

Referring to FIG. 15, one point on the polyester film 1 is pressed by the pressing means 6, and the conductive film 2,
4 is in point contact at the contact point Pa. In this case, both switching elements SXLa and SXHa are turned on to set the terminal XLa to a low level (ground potential) and terminal XHa to a high level (potential Vc), and both switching elements SYLa and SYHa are turned off to set the conductive film 4 to a high level. When set to impedance state, terminal YL
The potential at a becomes the potential at the contact point Pa. The potential of this contact point Pa is a potential that divides the potential Vc into Rx1:Rx2, and it is possible to calculate the X coordinate based on this potential. Further, the Y coordinate can be calculated by setting the setting state of the switching element in the opposite manner to that described above.

Each of the potentials at the terminals XLa and YLa is converted into digital data by an A/D converter 8 having a high input impedance and is applied to a CPU (central processing unit) 9. The CPU 9 calculates the X and Y coordinates of the contact point Pa based on the provided digital data.

At this time, for example, as shown in FIG.
When inputting with the pressing means 6 such as a detection pen or a finger, the palm 7 or the like comes into contact with the polyester film 1 and the conductive film 2
, 4 may come into contact at two places. in this case,
As shown in FIG. 15, the resistance between the contact point Pa caused by the pressing means 6 and the contact point Qa caused by the palm 7 or the like becomes a parallel resistance of the resistance Rx21 caused by the conductive film 2 and the resistance Ry21 caused by the conductive film 4, so that the terminal XLa-XHa and terminal YL
The resistance values between a and YHa are the normal resistance values Rx and R, respectively.
There is a problem that the value becomes lower than y, and a position completely different from the original contact point Pa is detected as the input coordinate.

An object of the present invention is to provide a coordinate input device that prevents erroneous input and is easy to use.

[0016]

[Means for Solving the Problems] The present invention holds a pair of sheet resistance sheets having electrodes at opposite ends thereof with a spacer interposed therebetween to maintain a uniform distance between the sheets, and the direction in which the electrodes are formed is The electrodes are arranged so as to be perpendicular to each other and in contact with each other when an arbitrary point on one sheet resistance sheet is pressed, and one electrode and the other electrode are connected to each sheet resistance sheet respectively. The switching means is connected to a high level and a low level through a switching means, and the switching means is controlled so that one of the pair of sheet resistance sheets has a gradient potential, and the switching means connected to the other sheet resistance sheet is connected to the high level and the low level through a switching means. In the coordinate input device, the coordinate input device detects the potential of the sheet resistance sheet on the side of the switching means that is brought into the high impedance state, and calculates the coordinates of the pressed point based on the detected potential. This coordinate input device is characterized in that the input sensitivity of a predetermined specific area on a sheet is set lower than the input sensitivity of other areas.

Further, the present invention is characterized in that the sheet thickness in the predetermined specific area is made thicker than the sheet thickness in other areas.

Furthermore, in the present invention, by making the size of the spacer in the predetermined specific area larger than the size of the spacer in the other area, the distance between the sheet resistance sheets in the specific area is increased from that in the other area. The distance between the sheet resistance sheets is set to be longer than the distance between the sheet resistance sheets.

Furthermore, the present invention is characterized in that the spacer installation density in the predetermined specific area is greater than the spacer installation density in other areas.

Furthermore, the present invention is characterized in that the predetermined specific area corresponds to an area that the operator's hand comes into contact with when pressing the sheet resistance sheet.

[0021]

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

[0022] Therefore, in the predetermined specific area, coordinates cannot be input without applying greater pressure than in other areas, and as a result, the surface resistance sheet may come into contact with the area other than the coordinates that should be input. This can be prevented. This makes it possible to reduce the occurrence of erroneous inputs and to provide a highly usable coordinate input device.

In a so-called pressure-sensitive type coordinate input device, the input sensitivity depends on the distance between 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. It is determined by the curvature of the tip.

[0024] If the same pressing means is used and the thickness of the sheet resistance sheet serving as the pressing surface is uniform, the greater the distance between the sheet resistance sheets by increasing the height of the spacer, the greater the pressure when inputting coordinates. is necessary. Therefore, by making the height of the spacer in the predetermined specific area larger than the height of the spacer in other areas, the input sensitivity of the specific area can be set low.

Furthermore, if the same pressing means is used and the height of the spacer is uniform, the thicker the sheet resistance sheet that becomes the pressing surface, the greater the pressure required when inputting coordinates. 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.

Furthermore, if the same pressing means is used, the thickness of the sheet resistance sheet serving as the pressing surface is uniform, and the height of the spacers is uniform, the deformation during pressing can be prevented by increasing the installation density of the spacers. If you make the area smaller,
A large amount of pressure is required when inputting coordinates. therefore,
By setting the density of spacers in the specific area higher than the density of spacers in other areas, the input sensitivity of the specific area can be set low.

Furthermore, if the same pressing means is used, the thickness of the sheet resistance sheet is uniform with respect to the pressing surface, and the height of the spacer is the same, the material of the sheet resistance sheet forming the pressing surface is hard. I see, a lot of pressure is required when inputting coordinates. Therefore, by selecting the material of the sheet resistance sheet in the predetermined specific area to be harder than the material of the sheet resistance sheet in other areas, the input sensitivity of the specific area can be set low.

[0028] Usually, coordinate input devices employ a pen input method and a touch input method. The pen input method is a method in which input is performed using a pressing means with a thin tip and made of a hard material, such as a ballpoint pen. The touch input method is a method in which input is performed using a pressing means made of a soft material with a relatively large curvature, such as a fingertip. In the pen input method, the pressing surface is small, so input instructions can be given with a relatively small pressure.In the touch input method, the pressing surface is large, so a relatively large pressure is required for input.

Therefore, in a coordinate input device in which areas with different input sensitivities are set as described above, by using the touch input method in areas with high input sensitivity and using the pen input method in areas with low input sensitivity, A coordinate input device that is easy to use can be provided.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view of a pressure-sensitive coordinate input device 21 which is an 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 set at both ends in the vertical direction of the paper in FIG. 1, and a work area 24 in which coordinates and the like are input using a pen 25 as a pressing means. The function selection area 22 is a touch input area where the input sensitivity is set low and where input is performed with a fingertip or the like.
The character input area 23 has a high input sensitivity and is a pen input area in which input is performed using a pen 25 or the like. As shown in FIG. 2, a character input area (pen input area) 23 is arranged near the hand of an operator who inputs coordinates.

FIG. 3 is a sectional view of the coordinate input device 21 taken along the section line III--III. The coordinate input device 21 includes a resistance layer (sheet resistance) 32 made of indium oxide, etc.
34 are respectively formed on opposing surfaces of the sheets 31,
33 are laminated together with a spacer 35 interposed therebetween. The spacer 35 has the role of maintaining a uniform distance between the resistance layers 32 and 34 and electrically insulating the resistance layers 32 and 34.

The sheet 31 is an input surface that is 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 that adjusts the distance between 1 and 33, the thickness of the sheet 31 that serves as the input surface, and the curvature of the tip of the pen 25 that is the pressing means. Therefore, as shown in FIG. 3, when spacers 35 of the same size are used, by increasing the thickness of the sheet 31, a large pressure is required when inputting coordinates. In other words, the input sensitivity is set low.

Therefore, as shown in FIG.
Even if the operator's palm or fingers come into contact with the pen input area 23 when pressing the function selection area 22 or the work area 24 using the never come into contact. This makes it possible to prevent erroneous inputs from occurring in the coordinate input device 21.

FIG. 4 is a plan view showing a schematic configuration of the coordinate input device 21. As shown in FIG. In FIG. 4, sheets 31 and 33 each have a uniform resistance layer 3 on opposing surfaces as described above.
2 and 34, and electrodes 31L, 31H; 33L, 33 shown with diagonal lines at opposite ends thereof
Terminals XL, XH; YL, YH are connected to these electrodes, respectively. The sheet resistance value of the sheets 31 and 33 is R between terminals XL and XH.
x, and Ry between terminals YL and YH, which usually has a resistance value of 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 a predetermined uniform interval via a spacer 35, etc., and electrically, as shown in FIG.
The two resistance layers 32 and 34 are in a non-contact state.

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

Therefore, it is also possible to set the resistance layer 32 in a high impedance state by setting both the terminals XL and This also applies to the resistance layer 34.

FIG. 6 shows a state in which a point on the sheet 31 is pressed with the pen 25, and the resistance layers 32 and 34 of the sheets 31 and 33 are in point contact at a contact point Pi. Therefore, switching elements SXL and SXH are both turned on, terminal XL is set to low level (ground potential), and terminal XH is set to low level (ground potential).
When is set to a high level (potential Vc) and switching elements SYL and SYH are both turned off to enter 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 value from the terminal XL to the contact point Pi is Rx1,
Let Rx2 be the resistance value from the contact point Pi to the terminal XH. Further, in the resistance layer 34 of the sheet 33, the resistance value from the terminal YL to the contact point Pi is Ry1, and the resistance value from the contact point Pi to the terminal YH is Ry2. Therefore, the potential at the contact point Pi becomes a potential that divides the potential Vc into Rx1:Rx2, and the X coordinate can be calculated by detecting the potential at the terminal YL. Furthermore, by setting the on/off state of the switching element in the opposite manner to the above, the Y coordinate can be calculated in the same manner.

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

FIG. 7 is a sectional view showing the configuration of a coordinate input device 21a which is another embodiment of the present invention. In this example,
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
The height hf of the spacer 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.

The input sensitivity can also be set low by increasing the distance between the sheets in the pen input area 23 in this manner. This embodiment also has the same effects as the coordinate input device 21 described above.

FIG. 8 is a sectional view showing the structure of a coordinate input device 21b which is 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 characteristics of the coordinate input device 21b are that the sheet thickness tf of the sheet 31 in the pen input area 23 is made thicker than the sheet thickness td in other areas, and the height hf of the spacer 35f is
This is because the height hd of the spacer 35d is selected to be longer than the height hd of the spacer 35d in other areas. As a result, the input sensitivity of the pen input area 23 is set lower than the input sensitivity of other areas. The coordinate input device 21b of this embodiment also has the same effects as those of the above-mentioned embodiments.

FIG. 9 is a plan view of a coordinate input device 21c which is 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 feature of c is that the spacer 35 in a predetermined specific area
This is because the installation density of the spacers 35 is selected to be larger than the installation density of the spacers 35 in other areas. In this embodiment, assuming that the operator is right-handed, the installation density of the spacers 35 on the lower right side of 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 other areas.

Therefore, the specific area is selected as an area where there is a possibility that when the operator presses the sheet 31 of the coordinate input device 21c, a part of the hand other than the pressing finger may come into contact with the sheet 31, Even if the operator's palm 28 or the like comes into contact with the sheet 31 as shown in FIG. 10 when pressing the sheet 31, the resistance layers 32 and 34 can be prevented from coming into contact at the contact portion. This embodiment also has the same effects as the coordinate input device 21 described above.

[0047]

As described above, according to the present invention, when an operator presses a sheet resistance sheet, it is possible to prevent sheet resistances from coming into contact with each other in areas other than the desired pressing area. As a result, it is possible to significantly reduce the occurrence of erroneous inputs to the coordinate input device, and to realize a coordinate input device that is easy to use and whose range of use can be expanded.

[Brief explanation of drawings]

FIG. 1: Pressure-sensitive coordinate input device 2 which is 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.

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

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

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

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

FIG. 7: Coordinate input device 21a which is another embodiment of the present invention.
FIG.

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

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

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

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

FIG. 12 is a cross-sectional view showing the structure of another conventional pressure-sensitive tablet 11.

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

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

FIG. 15 is a circuit diagram showing the 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 Working area 25 Pen 31, 33 Sheets 32, 34 Resistive layer 35 Spacer

Claims (5)

[Claims] 1. A pair of sheet resistance sheets having electrodes at opposite ends thereof are held with a spacer interposed therebetween to maintain a uniform distance between the sheets, and the electrode formation directions are perpendicular to each other, and They are arranged so that they come into contact with each other when an arbitrary point on one of the sheet resistance sheets is pressed, and one electrode and the other electrode of each sheet resistance sheet are connected to a high level through a switching means. the switching means is connected to a low level, and the switching means is controlled to cause one of the pair of sheet resistance sheets to have a gradient potential, and the switching means connected to the other sheet resistance sheet is brought into a high impedance state, In a coordinate input device that detects the potential of a sheet resistance sheet on the side of the switching means that is in the state and calculates the coordinates of a pressed point based on the detected potential, A coordinate input device characterized in that input sensitivity is set lower than input sensitivity of other areas. 2. The coordinate input device according to claim 1, wherein the sheet thickness in the predetermined specific area is made thicker than the sheet thickness in other areas. 3. By making the size of the spacer in the predetermined specific area larger than the size of the spacer in other areas, the distance between the sheet resistance sheets in the specific area can be increased from the distance between the sheet resistance sheets in the other area. Claim 1 characterized in that the distance is set longer than the distance between
Or the coordinate input device described in 2. 4. Claims 1 and 2, characterized in that the spacer installation density in the predetermined specific area is greater than the spacer installation density in other areas.
or the coordinate input device described in 3. 5. The coordinate input device according to claim 1, wherein the predetermined specific area corresponds to an area that an operator's hand comes into contact with when pressing the sheet resistance sheet.