JPS60196838A - Input device of coordinate - Google Patents

Abstract

PURPOSE:To obtain a tablet such as an electronic blackboard having a wide area by providing a coordinate input tablet with a plate-like resistor element having high resistance and a plate-like resistor element having low resistance and formed on the inner periphery of said high resistance sheet as electrodes. CONSTITUTION:The tablet is constituted of the plate-like resistor element 6 having high resistance, the low resistance plate-like resistor element 7 formed on the inner periphery of the high resistance film 6 and acting as an electrode, an anisotropic conductive rubber 8, pressure-sensitive rubber 4, and a film sheet 9 forming a conductive film on its back and acting as a protecting and electrode sheet. To obtain an X coordinate, voltage is applied to the x direction. When voltages EV and 0V are applied to points BC and AD respectively, the whole BC of the low resistance sheet 7 reaches a value close to EV and the whole AD of the sheet 7 reaches a value close to 0V. Since the grade from 0V to EV is formed between AD and DC of the sheet 7 and the high resistance sheet 6 driven through the anisotropic conductive rubber also has the grade from 0V to EV, the potential grades of both the resistors are equal.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a coordinate input device.

(Background technology) The basic configuration of a conventional tablet is shown in FIG.

A high-resistance film 2 is applied on an insulating substrate 1, a low-resistance film 3 is applied on the four sides around it, a pressure-sensitive rubber 4 is provided on the resistance films 2 and 3, and a conductor is placed on the back side of the upper part of the pressure-sensitive rubber 4. A flexible film sheet 5 provided with a membrane is provided.

The operation is performed in the X and V directions in a time-sharing manner, and when calculating the X coordinate,
Apply voltage in the X direction. When applying voltage in the X direction, apply voltage E (V) to point BC and 0 [■
), the entire low-resistance film (3) BC becomes E (V
), and the low resistance film (3) AD has a value close to 0 [v
] Take the neighboring value. Furthermore, the low resistance film 3AD and the low resistance film (3) DC have a potential gradient from O (V) to E (V), and the high resistance film 2 driven by the low resistance film (3) BC and AD also has a potential gradient of 0 (V) to E (V). Since there is a potential gradient from [v] to E (V), by making the resistance distribution inside each resistor 2 and 3 uniform, regardless of the magnitude of the resistance value, the potential gradient of both paper antibodies is approximately equal. They become equal, and the potential disturbance becomes the lessee.

Next, when calculating the Y coordinate, apply a voltage in the y direction, but point A
By applying voltage E (V) to point B and voltage 0 (V) to point CD, a potential gradient in the X direction is formed in the same manner as when determining the X coordinate.

When a voltage is applied alternately in the X direction and the
It is transmitted to the conductive film formed on the back surface of the film sheet 5 through the film. This potential is A/D converted in synchronization with the timing of drive voltages applied alternately in the xyx directions, and as a result xy coordinate values on the tablet are obtained.

However, the absolute accuracy of this conventional resistive film method depends on the uniformity of the resistance distribution of the resistive film 2.3.

In other words, as shown in FIG.
It is necessary to make the resistance distribution of each type of resistive film uniform.

In order to achieve a uniform resistance distribution, a trimming method or a method of controlling the resistive film coating conditions must be applied to the resistive film 2.3.

The trimming method involves setting terminal patterns for checking at regular intervals of 10 to 20 mm in the longitudinal direction of the low resistance film 3, and trimming and adjusting the resistance film so that the resistance between these terminals becomes the specified resistance value. This is the way to do it.

FIG. 2 shows plot data when straight lines are drawn in a matrix on the resistive film before trimming, and FIG. 3 shows plot data when straight lines are drawn in a matrix on the resistive film after trimming.

As mentioned above, it is absolutely necessary to correct the resistance distribution, but in the conventional resistive film method, the resistive film is formed by vacuum evaporation, so it cannot be produced in large quantities, and of course variations occur from piece to piece. Resistor 1111 corresponding to each variation
2 and 3, it was necessary to apply the above-mentioned trimming method to each sheet for uniformity, which was very inefficient. Furthermore, since the resistive film 2.3 is coated on the insulating substrate l, there is also a drawback that it cannot be made thin.

Furthermore, since the low-resistance film and the high-resistance film are formed on the same insulating substrate, if one of the resistance films is out of specification, the entire film becomes unusable, resulting in a low yield.

(Problems to be solved by the invention) In order to eliminate these drawbacks, the purpose of the present invention is to mass-produce a resistive film with little variation by using a planar resistor element that can be mass-produced as a resistive film, and to improve uniformity by trimming. Its features include a high-resistance first planar resistor element made by kneading fine carbon particles into a binder resin and coating it on a film; Pressure-sensitive rubber to be laminated, second planar resistor elements provided on the four outer edges of the first planar resistor element, and sheet-like electrodes to be laminated on the pressure-sensitive rubber. The second resistor element has a lower resistance than the first resistor element, and the position of the pressure point applied to the pressure sensitive rubber via the electrode layer is set to the first resistor element. There is a coordinate input device that provides according to the applied potential gradient.

(Structure and operation of the invention) An embodiment of the invention is shown in FIG.

In Fig. 4, 6 is a high-resistance planar resistor element, for example, a biaxially stretched polyester film-L coated with fine carbon particles kneaded with a binder resin and then cut into a certain length. This corresponds to the high resistance film 2. Hereinafter, this will be referred to as a high resistance sheet.

7 is a low-resistance sheet resistor element for acting as an electrode at the four corners of the high-resistance film 6; for example, like the high-resistance sheet resistor element 6, a biaxially stretched polyester film is coated with a binder resin. This film corresponds to the conventional low-resistance film 3, which is coated with fine carbon particles kneaded with carbon and continuously molded, and then cut into a certain length. Hereinafter, this will be referred to as a low resistance sheet.

8 is an anisotropic conductive rubber that connects the high-resistance sheet 6 and the low-resistance sheet 7, in which conductors are arranged in countless numbers in the thickness direction of the sheet, and the conductors protrude from the surface in several colors. It functions as a conductor in the direction perpendicular to the direction, and as an insulator in the parallel direction.

4 is the same pressure sensitive rubber as the conventional one.

9 is a film sheet that functions as a protection and electrode sheet with a conductive film formed on the back surface, which is different from the conventional film sheet 5.
It is similar to Hereinafter, it will be referred to as a film sheet.

The operation will be explained below. The operation is performed in the X and X directions in a time-division manner, and when determining the X coordinate, a voltage is applied in the X direction.

When applying voltage in the X direction, apply voltage E (V) to point BC.
and applying 0 (V) to point AD, the low resistance sheet) (7) BC takes a value near E (V) as a whole, and the low resistance sheet (7) AD as a whole takes a value of 0 [V]. Takes the neighboring value. Also, low resistance sheet (?) A D and low resistance sheet (7) DC has a potential gradient from 0 [V] to E (V), and low resistance sheet (7) BC and AD make it 8
The high resistance sheet 6 driven through the anisotropic conductive rubber is also 0
Since there is a potential gradient from (V) to E (V), by making the resistance distribution inside each resistor sheet 6.7 uniform, regardless of the magnitude of the resistance value, the potential gradient of both paper antibodies can be made uniform. are almost equal, and the potential disturbance becomes the lessee.

Next, when calculating the Y coordinate, apply a voltage in the X direction, but point A
By applying voltage E (V) to point B and voltage 0 (V) to point CD, a potential gradient in the X direction is formed in the same manner as when determining the X coordinate.

When a voltage is applied alternately in the X direction and the It is transmitted to the conductor film formed on the back surface of the sheet 9. This potential is A/D converted in synchronization with the timing of drive voltages applied alternately in the xyx directions, and as a result, the xy coordinate values on the tablet are obtained.

As explained above, the uniformity of the potential distribution on the resistance sheet 6.7 depends on the uniformity of the resistance distribution.
7 can be mass-produced and is composed of a dielectric resistor element with very little variation, so even if there is a slight disturbance in uniformity, there is no need to trim each resistor film, making it extremely efficient. It is.

Note that the resistor element commercially available from Toshiku Co., Ltd. can be used as the resistor element, and one with a length of several hundred meters is already available. Moreover, since the tablet structure of the present invention does not require an insulating substrate, it can be made thinner, and since the high-resistance sheet 6 and the low-resistance sheet 7 are manufactured separately, stable quality can be used. All you had to do was replace what was bad or what had gone bad. The sheet resistance of the high resistance sheet 6 and the low resistance sheet 7 is preferably 1, for example, 4 to 5 Ω/hole and 350 to 800 Ω/hole, respectively.

In this embodiment, during maintenance, the resistance sheets 6 and 7 are connected by the anisotropic conductive rubber 8, so that the contact is stable and can be easily separated.
Another advantage is that they can be easily replaced. However, the anisotropic conductive rubber 8 may be removed and the high-resistance sheet 6 and the low-resistance sheet 7 may be pressed into direct contact with each other.

(Effects of the Invention) Since the present invention uses the resistance sheets 6.7, it can be applied to tablets with a wide area, such as electronic whiteboards. However, it goes without saying that the present invention can also be applied to a small tablet or the like in which a resistance sheet 6.7'll L air gap is formed instead of the pressure sensitive rubber 4.

Further, it goes without saying that when the surfaces of both anti-resistance sheets 6 and 7 have good adhesion, the anisotropic conductive rubber 8 provided for connecting the high-resistance sheet 6 and the low-resistance sheet 7 becomes unnecessary.

[Brief explanation of drawings]

Figure 1 is a diagram of the configuration of a conventional tablet, and Figure 2 is a diagram of the resistive film position accuracy before trimming. Figure 3 is a diagram of the resistor film position accuracy after trimming. FIG. 4 is a block diagram of a tablet according to the present invention. 1-m-insulating substrate, 2-m-high resistance film, 3-m-low resistance film, 4-m-pressure sensitive rubber, 6--high resistance sheet, 7--
-Low resistance sheet, 8-m-Anisotropic conductive rubber, 9-m-Electrode protection sheet. Patent applicant Oki Electric Industry Co., Ltd. Patent application agent Megumi Yamaki - Figure 2 Figure 3

Claims (1)

[Claims] a high-resistance first planar resistor element in which fine carbon particles are kneaded with a binder resin and coated on a film ball;
Pressure-sensitive rubber laminated in the center thereof, second planar resistor elements provided on the four outer edges of the planar resistor element of WIJl, and a sheet laminated on the pressure-sensitive rubber. The second resistor element has a lower resistance than the first resistor element, and the position of the pressure point applied to the pressure sensitive rubber via the electrode layer is set to the first resistor. A coordinate input device characterized in that a coordinate input device provides information according to a potential distribution applied to a body element.