JPS6055428A - Coordinate input device - Google Patents

Abstract

PURPOSE:To improve the durability of a coordinate input device by stacking a film for protection upon two detection plates. CONSTITUTION:The coordinate input device consists of the 1st detection plate 1 formed by sticking a resistance film 12 to the reverse surface of an insulating plate 13 with plasticity and providing electrodes at two facing sides and the 2nd detection plate 8 which is similar to said plate and provided thereunder across a space 7. Both detection plates 1 and 8 are normally insulated from each other because of the presence of the spacer 8, but when specific pressure is applied with a pen for input operation, they conduct to each other electrically to detect the coordinates of the input position of the pen. In this case, the film for protection, e.g. polyester film 14 is stacked on the top surface of the insulating plate 13 of the 1st detection plate 1 to improve the durability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a coordinate input device for handwritten characters.

The configuration of the conventional example and its problems A coordinate input device detects the coordinate position of a pen in order to input handwritten characters. The detected character information is sent to a computer or the like and displayed on a display device such as a CRT.

In order to know the position of a pen for handwriting input, conventionally known coordinate input devices are equipped with detection plates that detect coordinate positions in the X-axis direction and Y-axis direction. There is a system in which the position coordinates of the pen are known by having the pen receive a position signal from a detection plate by inductive or capacitive coupling between the plate and the pen, or conversely by receiving a signal from the pen by the detection plate.

Another conventionally known coordinate input device uses a resistor plate with uniformly distributed resistance values. A conventional method using this resistor plate will be explained below with reference to the drawings.

In Fig. 1, 1 is the first detection plate, and a resistive film with a uniform resistance value is attached to the lower surface of the flexible insulating plate so that the point input with the pen 2 is deformed downward. It further has electrodes 3.4 on its two opposing sides. Below the first sensing plate 1, a resistive film with a uniformly distributed resistance value is attached to the upper surface of the insulating plate, and electrodes 6, 6 are placed on two opposing sides at different positions from the first sensing plate 1. and further includes a first detection plate 1
A second sensing plate 8 having insulators 7 deposited on the resistive film at predetermined intervals as spacers for insulating between the two faces. When there is no input by the pen 2, the first detection plate 1 and the second detection plate 8 are not electrically connected due to the insulator 7, but now the pen 2 is used to detect the first detection plate 1 and the second detection plate 8. If you input pressure to any point from above with a pressure higher than the predetermined value, the first
Since the detection plate 1 is flexible, it is electrically connected to the second detection plate 8 at the input point. At this time, for example, if a constant voltage is applied between electrodes 3 and 4, a divided voltage opposite to the position of the pen 2 in the X-axis direction will be derived at electrode 6, and conversely, a constant voltage will be applied between electrodes 5 and 6. If you keep it, you can put pen 2 on electrode 3.
Since the divided voltage corresponding to the position in the Y-axis direction is derived, the coordinates of the input position of the pen 2 can be known. The position detection circuit 9 applies a constant voltage between these series of electrodes, derives divided voltages from the other electrodes, and alternately switches between these two operations in the X-axis direction and the Y-axis direction. The position detection circuit 9 also performs analog-to-digital conversion on the input divided voltage and outputs it to the arithmetic unit as position information. The arithmetic device can determine the coordinates of the input position of the pen 2 by performing simple calculations, and can also display characters input with the pen 2 on a display device such as a CRT.

FIG. 2 is a front sectional view of the conventional coordinate input device shown in FIG. The second sensing plates 1 and 8 are insulating plates 1o and 13 with resistive films 11 and 12 having uniformly distributed resistance attached to one side, and an insulating film 7 on the second sensing plate 8. is placed.

In such a device, input is made using a pen 2. That is, by moving the pen 2 in any direction, the character 9 can be written.
Figures etc. are input, but when moving the board/2 or first placing the board/2 on the first detection board 1, the surface of the insulating plate 13 of the first detection board The tip of the pen 2 may get caught in the insulating plate 13, which may cause cracks in the resistive film 12 attached to the insulating plate 13. Therefore, the resistive film 12 of the first sensing plate 1 lacks uniformity, and there is a drawback that coordinates different from those inputted may be read incorrectly.

OBJECTS OF THE INVENTION It is an object of the present invention to solve these conventional problems and provide a durable coordinate input device.

Structure of the Invention The coordinate input device of the present invention includes two opposing sensing plates having a resistive film and electrodes provided on two sides, and an insulator provided between the two sensing plates. The first contact with the pen
Lay the film on top of the flexible insulating plate of the first detection plate, and make sure that the tip of the pen and the insulation part of the first detection plate do not touch directly, and even if the tip of the pen and the film are scratched or scratched. ,
Even if the stacked films are stretched, the insulating plate is not stretched at all.

Description of examples An embodiment of the present invention will be described below with reference to FIG.

The configuration is basically the same as that shown in Figures 1 and 2),
Identical parts are given the same reference numerals.

To explain only the differences, 14 is a film superimposed on the upper surface of the insulating plate 13, and polyester film 76 is
~190μ and triacetate film 80-190
The insulating plate 13 of the first sensing plate 1 is covered with a polyester film, and the insulating plate 10 of the second sensing plate 8 is
A glass plate was used for , an ITO film was used for the uniform resistance films 11 and 12, and silicone rubber was used for the insulator 7. Regarding the film 14, a film in which 0.5 phr of stearic acid amide was mixed as a lubricant rich in external activity was also investigated.

Durability test method Configure the coordinate input device as shown in Figure 3,
With the power of 10. I input a straight line. This line was monitored with a CRT, and the life was determined when distortion occurred.

Durability test results When we investigated the lifespan of the configuration shown in Figure 2, we found that it was approximately 3.
It withstood about 1,000 degrees of writing input. However, considerable variation was observed depending on the method of written input, with +60Q times and -
There were over 1000 variations.

On the other hand, when the films 14 were stacked together as in the example of the present invention, both the polyester film and the triacetate film had a lifespan of about 500 cycles. As for thickness, 70 to 80μ is sufficient. Also, in the case of a film containing a lubricant, the lifespan was well over 5,000 times, and the tip of the pen 2 hardly caught. therefore,
It is expected that the lifespan will be longer if a lubricant is added. As for the material of the film 14, it is desirable that the pen 2 is not scratched by the material.

The type of lubricant and the amount added vary depending on the type of film, the degree of transparency required, etc. Further, the lubricant may be mixed into the insulating plate 13 in addition to the film, or may be contained only in the insulating plate 13. Note that it is also possible to apply it between the film 14 and the insulating plate 13 without mixing it.

As described above, the coordinate input device of the present invention has a protective film overlaid on two detection plates, and has greater durability than conventional coordinate input devices using this method. This could have been significantly improved.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing a conventional coordinate manpower device, FIG. 2 is a front sectional view thereof, and FIG. 3 is a front sectional view showing an embodiment of the device of the present invention. 1... Ml detection plate, 2... Pen, 7
...Insulator (spacer), 8...2nd
Detection plate, 11... Resistive film of second detection plate, 1
2... Resistive film of the first detection plate, 13... Insulating plate of the first detection plate, 14... Film.

Claims (1)

[Claims] 0) A resistive film is attached to the lower surface of a flexible insulating plate, and a first sensing plate having electrodes on two opposing sides is superimposed on the upper surface of the first sensing plate. a second sensing plate placed opposite to the lower surface of the first sensing plate and having a resistive film attached to the upper surface of the insulating plate and having electrodes on two opposing sides; A coordinate input device comprising a detection plate and an insulator that provides a gap between the second detection plate. ? 2.) The coordinate input device according to claim 1, wherein at least one of the film and the flexible insulating plate contains a lubricant rich in external activity. G3) The coordinate input device according to claim 1, wherein a lubricant is applied to the back surface of the film or the top surface of the highly flexible insulating plate.