JPH07104909A - Plotting tablet - Google Patents

Abstract

PURPOSE:To detect the position coordinate of a plotting tablet surface pressed by the tip of a pen for input or the like while reducing power consumption by respectively adjusting resistance values between a pair of electrodes on respective panels at specified values. CONSTITUTION:Concerning a plotting tablet 1, the resistance values between X coordinate reading electrodes 5x and 5x and between Y coordinate reading electrodes 5y and 5y are respectively adjusted at 100-5000OMEGA. Namely, this tablet is provided with an X coordinate reading panel 2 and a Y coordinate reading panel 3 which shapes and sizes are equal each other, a conductive layer 4 and the X coordinate reading electrodes 5x and 5x are successively formed on one side of the X coordinate reading panel 2, and a conductive layer 4 and coordinate reading electrodes 5y and 5y are successively formed on one side of the Y coordinate reading panel 3. Therefore, since the resistance value between a pair of electrodes is adjusted at 100-5000OMEGA for each panel, the position coordinate on the surface of the plotting tablet 1 pressed by the tip of the pen for input or the like is detected with low power consumption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing tablet suitable for pen-touch image input, and more particularly to a drawing tablet capable of image input with low power consumption.

[0002]

BACKGROUND OF THE INVENTION A drawing tablet as shown in FIG. 1 is conventionally known. This drawing tablet 1 has X
A coordinate reading panel 2 and a Y coordinate reading panel 3 are provided, and a conductive layer 4 is formed on one surface of the X coordinate reading panel 2 and one surface of the Y coordinate reading panel 3, respectively.

On the surface of the conductive layer 4 formed on one surface of the X-coordinate reading panel 2, a pair of X-coordinate reading electrodes 5x and 5x are further formed so as to face both peripheral edge portions thereof. Further, on the surface of the conductive layer 4 formed on one surface of the Y-coordinate reading panel 3, a pair of Y-coordinate reading electrodes 5y and 5y are further formed so as to face both peripheral edge portions thereof.

In the drawing tablet 1, the conductive layer 4 formed on one side of the X coordinate reading panel 2 and the conductive layer 4 formed on one side of the Y coordinate reading panel 3 are insulating spacers (not shown). And are substantially parallel to each other. Further, in the drawing tablet 1, the X coordinate reading electrode 5x and the Y coordinate reading electrode 5y are arranged so as to be orthogonal to each other.

Of these, X coordinate reading electrodes 5x, 5x
Circuits are formed between the Y coordinate reading electrodes 5y and 5y. Also, in each circuit,
For example, a constant voltage power supply 7, a position coordinate detection circuit 10 including an A / D converter 8 and a CPU 9 are connected via an analog switch 6, and an image input device is constituted by this.

In this type of image input device, when the constant voltage power supply 7 is applied, high speed switching of the analog switch 6 is repeated. Then, the constant voltage power source 7 is electrically connected to the X coordinate reading electrodes 5x and 5x, and the Y coordinate reading electrodes 5y and 5y are electrically connected to the position coordinate detecting circuit 10, and the constant voltage power source 7 is The state in which the Y coordinate reading electrodes 5y and 5y are electrically connected and the X coordinate reading electrodes 5x and 5x are electrically connected to the position coordinate detecting circuit 10 is alternately repeated at high speed. In this manner, the surface of the drawing tablet 1 is pressed by the tip of an input pen or the like while the image input device is driven, and the X coordinate reading panel 2 is pressed.
The conductive layer 4 formed on one side of the Y coordinate reading panel 3 and the conductive layer 4 formed on the one side of the Y coordinate reading panel 3 are in contact with each other at point A, and the position coordinates (X coordinate and Y coordinate) of the point A are sequentially A / D. It is designed to be detected via the converter 8 and the CPU 9.

In the image input device as described above, depending on the drawing tablet 1, the power consumption required for image input becomes too large, or the tip of an input pen or the like is used while the image input device is driven. Even if the surface of the drawing tablet 1 is pressed, the position of the pressed point cannot be detected by the position coordinate detection circuit.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems in the prior art, in which the position coordinates of the surface of the drawing tablet pressed by the tip of an input pen or the like have low power consumption. The purpose is to provide a drawing tablet that can be detected.

[0009]

SUMMARY OF THE INVENTION A drawing tablet according to the present invention comprises two panels each having a conductive layer formed on one surface of an insulating substrate and a pair of electrodes formed so as to face a peripheral portion of the surface of the conductive layer.
A drawing tablet in which conductive layers are arranged in parallel to face each other via a spacer,
The resistance value between the pair of electrodes in these panels is adjusted to 100 to 5,000 Ω, respectively.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The drawing tablet according to the present invention will be specifically described below with reference to the drawings. The drawing tablet according to the present invention is shown in FIG. 1 except that the resistance value between the X coordinate reading electrodes 5x and 5x and the resistance value between the Y coordinate reading electrodes 5y and 5y are adjusted to 100 to 5,000Ω, respectively. It is similar to the drawing tablet 1.

That is, the drawing tablet according to the present invention comprises an X-coordinate reading panel 2 and a Y-coordinate reading panel 3 having the same shape and size.
The conductive layer 4 and the X coordinate reading electrodes 5x and 5x are sequentially formed on one surface of the X coordinate reading panel 2, and the conductive layer 4 and the Y coordinate reading electrodes 5y and 5y are sequentially formed on one surface of the Y coordinate reading panel 3.

Then, the X coordinate reading panel 2 and Y
One of the coordinate reading panels 3, for example, the X coordinate reading panel 2 is usually made of a flexible material, for example, a transparent plastic film such as a polyethylene terephthalate film (hereinafter referred to as PET film).

The preferable thickness of the X-coordinate reading panel 2 is 50 μm including the thickness of the conductive layer 4 from the point of pen input.
It is m to 1 mm. In addition, the Y coordinate reading panel 3
It consists of a substrate which may be flexible or rigid, for example a glass substrate.

In the drawing tablet according to the present invention, normally,
1 × 10 ⁻⁴ to 1 × 10 ⁻¹ Ω · cm, preferably 2 × 10
^-4 to 4 × 10 ^-2 Ω · cm, and has a volume resistivity of 0.
01-0.2 μm, preferably 0.02-0.08 μm
A conductive layer 4 having a film thickness of 1 is formed on one surface of the X coordinate reading panel 2 and one surface of the Y coordinate reading panel 3.

Conductive layer 4 having volume resistivity as described above
Can be obtained by forming a thin film made of a conductive material such as ITO on one side of the X coordinate reading panel 2 or one side of the Y coordinate reading panel 3 by a sputtering method or the like.

In the conductive layer 4 formed on one surface of the X-coordinate reading panel 2, the resistance value between the X-coordinate reading electrodes 5x and 5x is the width of the X-coordinate reading electrode 5x, the distance between the X-coordinate reading electrodes 5x and 5x, The volume resistivity of the conductive layer 4 and the film thickness of the conductive layer 4 are adjusted to 100 to 5,000 Ω.

Similarly, in the conductive layer 4 formed on one surface of the Y coordinate reading panel 3, the Y coordinate reading electrodes 5y and 5y are formed.
The resistance value between them is adjusted to 100 to 5,000Ω by the width of the Y coordinate reading electrode 5y, the distance between the Y coordinate reading electrodes 5y and 5y, the volume resistivity of the conductive layer 4 and the film thickness of the conductive layer 4.

The resistance value of the conductive layer 4 between the X coordinate reading electrodes 5x and 5x and the resistance value of the conductive layer 4 between the Y coordinate reading electrodes 5y and 5y are 100 to 5,000, respectively.
It suffices that the values are adjusted to 0Ω, and different values may be used.

When the resistance value between these electrodes is less than 100 Ω, excessive electric power is consumed by the drawing tablet due to the current value flowing between these electrodes, and conversely, when it exceeds 5,000 Ω, these electrodes are consumed. Almost no current flows between them. For example, the A / D converters 8 and C in FIG.
The input signal detected through the PU 9 and noise cannot be distinguished, or the detected coordinate position is displaced.

Generally, in a drawing tablet, the above-mentioned electrode width and inter-electrode distance are set according to the size of the panel (X coordinate reading panel 2 and Y coordinate reading panel 3).

According to the present invention, the conductive layer 4 is formed so that the resistance value of the conductive layer 4 between the electrodes 5x, 5x or between the electrodes 5y, 5y is 100 to 5,000 Ω according to the electrode width and the distance between the electrodes. The conductive material to be formed and the film thickness of the conductive layer 4 are selected.

Also, a pair of X coordinate reading electrodes 5x, 5
Specific examples of the electrode material used when forming the x and Y coordinate reading electrodes 5y and 5y include metal materials such as silver.

[0023]

According to the present invention, a drawing tablet is provided with two panels in which a conductive layer is formed on one surface of a panel insulating substrate and a pair of electrodes are formed so as to face a peripheral portion of the surface of the conductive layer. Since the resistance value between the pair of electrodes is adjusted to 100 to 5,000 Ω for each panel,
The position coordinates of the surface of the drawing tablet pressed by the tip of the input pen or the like are detected with low power consumption.

[0024]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0025]

Example 1 An ITO film having a different resistance value was formed as a conductive layer on one surface of a 10 cm square glass substrate by a sputtering method. Then, a pair of silver electrodes was formed so as to face the peripheral edge of the surface of the ITO film formed on one surface of this glass substrate, to prepare a panel.

A voltage of 5 V was applied between both electrodes of the panel thus obtained, the current flowing between both electrodes was measured, and the power consumption of the panel was calculated. The results are shown in Figure 2.

[0027]

[Example 2] IT as a conductive layer on one side of a PET film
An O film was formed by a sputtering method, and then a pair of silver electrodes was formed in the same manner as in Example 1, the distance between X coordinate reading electrodes was 10 cm, and the resistance value between X coordinate reading electrodes was 4.
An X coordinate reading panel having 800Ω was prepared.

In addition, ITO was used as the conductive layer in the same manner as above except that a glass substrate was used instead of the PET film.
A Y-coordinate reading panel in which a film and a pair of silver electrodes are sequentially formed so as to face the periphery of the surface of the conductive layer, the Y-coordinate reading electrode distance is 10 cm, and the Y-coordinate reading electrode resistance value is 4,600 Ω. It was created.

On the ITO film of this Y-coordinate reading panel, a diameter of 100 μm and a height of 1 were obtained by screen printing.
Insulating dot spacers of 5 μm were formed with a pitch of 5 mm.

The X-coordinate reading panel and the Y-coordinate reading panel with insulating dot spacers obtained as described above are arranged so that the X-coordinate reading electrode and the Y-coordinate reading electrode are orthogonal to each other as shown in FIG. Then, the X-coordinate reading panel and the Y-coordinate reading panel and the conductive layer formed on one side of the panel were arranged to face each other, and the drawing tablet was assembled.

On the drawing tablet thus obtained, as shown in FIG. 1, an analog switch 6, a constant voltage power source 7,
When the A / D converter 8 and the CPU 9 were connected and the drawing tablet surface was pressed with the tip of an input pen or the like while applying a voltage of 5 V to the drawing tablet, the pressing point X
The coordinates and the Y coordinate were detected correctly.

[0032]

Comparative Example 1 A drawing tablet was prepared in the same manner as in Example 2 except that the resistance value between X-coordinate reading electrodes was 10,000Ω and the resistance value between Y-coordinate reading electrodes was 8,000Ω by changing the conditions for forming the ITO film. Got

As shown in FIG. 1, the drawing tablet thus obtained has an analog switch 6, a constant voltage power supply 7,
When the A / D converter 8 and the CPU 9 were connected and the drawing tablet surface was pressed with the tip of an input pen or the like while applying a voltage of 5 V to the drawing tablet, the pressing point X
A positional shift occurred in the coordinates and the Y coordinate, and the X coordinate and the Y coordinate of the pressed point could not be accurately detected.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a drawing tablet according to the present invention.

FIG. 2 is a graph showing a relationship between a resistance value between reading electrodes and power consumption of the drawing tablet according to the present invention.

[Explanation of symbols]

 1 ... Drawing tablet 2 ... X coordinate reading panel 3 ... Y coordinate reading panel 4 ... Conductive layer 5x ... X coordinate reading electrode 5y ... Y coordinate reading electrode 6 ... Analog switch 7 ... Constant voltage power supply 8 ... A / D converter 9 ... CPU 10 ... Position coordinate detection circuit

Claims (1)

[Claims] 1. A two-panel panel, in which a conductive layer is formed on one surface of an insulating substrate, and a pair of electrodes are formed so as to face a peripheral portion of the surface of the conductive layer, and the conductive layers face each other in parallel. In the drawing tablet formed by interposing spacers as described above, the resistance value between the pair of electrodes in each panel is 100.
A drawing tablet characterized by being adjusted to ~ 5,000 Ω.