JPS6029971B2 - coordinate position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [1' Description of the Field to Which the Invention Pertains The present invention relates to a coordinate position detection device, and particularly to a coordinate position detection device that detects the position coordinates of an input point at high speed.

[2] Description of conventional technology In graphical input devices such as tablets and digitizers,
Various methods are known as methods for determining the positional coordinates of an input point, and a method with a detection principle suitable for the purpose is used depending on the purpose of use, positional accuracy, price, and other conditions.

One of these detection principles is a method of detecting position coordinates using an input board having the structure shown in FIG. 1st
In the figure, line electrode groups parallel to the x and y directions are provided, and the lines in the x and y directions are usually not in contact with each other, and when there is an input, that is, one point on the surface is pressed. Then, the structure is such that the line in the x direction and the line in the y direction touch at that point. The position of this contact point is determined in a similar way to television scanning. That is, for example, the contact point of SWy is set to y, and the contact point of SWx is sequentially moved from x to xn to scan in the x direction. Next, SWy is equalized and SWx is similarly scanned from x to xn. In this way, the point of contact (x in the figure)
:, yj), an electrical path connecting Py and Px is formed, so its position can be known. Of course, even if there are a plurality of contact points, they can be detected. In this method, it is necessary to scan each point on the entire surface to detect one point on the surface, and for inputs with movement, the entire input surface is scanned within a time such that the movement can be ignored. Since it must be scanned, high-speed operation is required. That is, if the numbers of lines in the x and y directions are n and n, respectively, and the time interval for scanning the entire surface is T, then the clock frequency of SWx is n=ratio/T. For example, n=1000, T
If = 1/100, then n = 100 MHz. Therefore, electronic circuits are required to be high-speed.
It has the disadvantage of being extremely uneconomical. {3} Purpose of the invention In order to solve these drawbacks, the present invention
The purpose of this invention is to enable independent detection of directional coordinates and reduce the clock frequency required for detection.The drawings will be described in detail below.

[4] Explanation of the structure and operation of the invention FIG. 2 shows an embodiment of the invention, in which 1 is an input board, 2 and 4 are line electrode sheets, and 3
1 shows a surface electrode sheet, 5 and 6 address detection circuits, 7 and 8 address output terminals, and 9 a power supply.

FIG. 3 is a detailed view showing the front and cross sections of the wire electrode sheets 2 and 4 shown in FIG. 1, in which 21 is an insulating sheet and 22 is a wire electrode.

The line electrodes 22 are formed in a straight line on the insulating sheet 21 in parallel and at regular intervals. For the sake of explanation, wire electrode 2
The surface on which 2 is formed will be referred to as the line electrode surface side of the line electrode sheet 2, and the surface on the opposite side will be referred to as the back surface of the line electrode sheet. As shown in FIG. 2, the input board 1 has a line electrode sheet 2, a surface electrode sheet 3, and a line electrode sheet 4 arranged in this order from the top. The line electrode surfaces of the electrode sheets 4 face each other with a surface electrode sheet in between, and the directions of the line electrodes 22 of the line electrode sheets 2 and 4 are perpendicular to each other.

The line electrodes 22 of the line electrode sheets 2 and 4 are all connected to address detection circuits 6 and 5 by lead wires. Further, the surface electrode sheet 3 is a conductor on both sides (front and back) and is connected to a power source 9 having a constant voltage. The line electrode sheets 2 and 4 and the surface electrode sheet 3 are usually separated when there is no input pressure, and when there is input pressure, only the pressed portions come into contact with each other.

Next, the operation of the present invention will be described.

When input pressure is applied to the input board 1, the pressure causes the wire electrodes 22 of the wire electrode sheets 2 and 4 to come into contact with the surface electrodes.
Therefore, the address detection circuit 5, 6' detects which line electrode 22 of the line electrode sheets 2, 4 has come into contact with the surface electrode sheet 3. This is done as shown in FIG.
FIG. 4 is a diagram showing only the lower half of the input board 1, and is a diagram for explaining the operation of detecting the position of the line electrodes of the line electrode sheet 4 on the lower surface. In the figure, 41 is a switch that rotates at regular intervals, and 42 is a detection terminal.

This switch 41 scans the wire electrodes 22 sequentially from the left, so when the switch 41 comes to the bran electrode 22 that is in contact with the surface electrode sheet 3, the voltage of the power source 9 is displayed on the detection terminal 42. be exposed. Therefore, by measuring the timing at which the switch 41 rotates, the position of the wire electrode 22 in contact can be known. Since this operation is the same even if the line electrode sheet is above, the position of the line electrode 22 in contact with the line electrode sheet 2 on the upper surface can be known by the same operation. Since it is clear that these operations can be performed independently upward and downward,
When the switch rotates once, the input positions in the x direction and the y direction are detected. Therefore, this has an extremely large effect compared to the conventional one shown in FIG. That is, if the number of bran electrodes in the upper and lower wire electrode sheets is n, and the time interval at which the switch moves is t, then
The time required to detect the position of the input point is n2 times in the conventional case, but only nt in the case of the present invention. Therefore, the position coordinates of the input point can be detected at extremely high speed. Also, this means that
If the detection time is fixed, the frequency at which the switch operates can be reduced, which means that there is an advantage that the device can be configured economically. Of course, a logic circuit having the same effect as such a rotating switch can also be constructed. Next, with the rotating switch as described above, it takes a certain amount of time to detect the input position, but in another embodiment shown in FIG. 6, the position can be detected as soon as the input is made. In the figure, 43 is a coder that converts four inputs into two bits. The figure shows an example of four wire electrodes. This outputs 0, 1, 2, and 3 expressed in 2-bit binary numbers to wide and 0, and the presence or absence of contact to Puch. In this example, the number of electrode wires is four, but even if the number of electrode wires is increased, it is easy to configure it with a normal logic circuit. When the number of electrode lines is n, encoding can be performed using at least log2n bits. Furthermore, in the present invention, a protective sheet or the like can be provided on the uppermost surface of the input board to protect the input surface from wear caused by input.

Although the structure of the input board has been described as having three sheets, it can also be constructed as having four sheets, as shown in FIG. In the case of a four-layer structure as shown in FIG. 7, signal output terminals can be taken out from the surface electrode sheet as shown in FIG.

Wind Effects of the Invention As explained above, according to the present invention, the position coordinates of an input point can be detected at high speed, and when a predetermined detection time is sufficient, the speed of scanning etc. can be compared. It can be delayed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram explaining the problems of the conventional configuration, FIG. 2 is an embodiment of the configuration of the present invention, FIG. 3 is an example of a wire electrode sheet, and FIGS. FIG. 6 is an explanatory diagram illustrating a position detection mode according to the invention, FIG. 6 is an explanatory diagram illustrating another embodiment of the configuration for position detection, and FIG. 7 is an explanatory diagram illustrating an arrangement mode of a line electrode sheet and a surface electrode sheet. In the figure, 1 is an input board, 2 and 4 are line electrode sheets, 3 is a surface electrode sheet, 5 and 6 are address detection circuits, 9 is a power source, 22 is a line electrode, and 43 is a coder. 2 figures 3 figures 4 figures 3 figures 6 figures 7 figures

Claims (1)

[Claims] 1 Consists of a first electrode sheet having a plurality of parallel line electrodes, a second electrode sheet, and a surface electrode sheet, and the direction of the line electrodes of the first electrode sheet and the direction of the line electrodes of the second electrode sheet are mutually In a coordinate detection device that detects the position when there is a pressure applied by an input, the first electrode sheet, the second electrode sheet, and the surface electrode sheet come into contact at the pressed location only when the pressure is applied. an input board arranged to It consists of a second detection means for detecting the position of the wire electrode in contact, the first detection means detects the first direction, and the second detection means detects the second direction. 1. A coordinate position detection device that detects the position coordinates of an input point by performing these operations temporally independently of each other.