JPS60205624A - Coordinate position detector - Google Patents

Abstract

PURPOSE:To prevent an error of the detection of a coordinate position by using an output terminal led out of the detection probe of an input pen as a position signal terminal and an output terminal led out through a pressure-sensitive conductive terminal as a pen-down signal terminal. CONSTITUTION:When the input pen 1 is put close to a plane resistor 13, a position signal having a specific phase shift from a reference signal is induced at the tip part of the detection probe 2 and outputted to a position signal terminal 11. This signal is larger and larger as the pen is closer and closer to the resistor 13 and attains to its maximum value when the pen contacts the resistor 13. Then when the pen is further pressed against the resistor 13, a pressure-sensitive rubber switch 3 is pressed to conduct, and the position signal is outputted to the pen-down signal terminal 12 and inputted to a pen-down detecting circuit 18. The circuit 18 compares this signal with a reference value and outputs a pen- down signal when the signal exceeds the reference value. The output signal at the terminal 12 has chattering possibly, but the output at the signal terminal 11 is maximum and stable, so there is no error in the detected coordinate position.

Description

[Detailed description of the invention] ta) Technical field of invention The present invention relates to a coordinate position detection device, and particularly to a coordinate position detection device.

The present invention relates to an improvement in a pen-down detection method that enables reliable and easy detection of pen-down position.

(bl) Prior Art and Problems As shown in FIG. When the pen is down, the pressure-sensitive rubber switch 3 is pressed and conducts.Therefore, the position signal detected at the tip of the detection probe 2 is output via the pressure-sensitive rubber switch 3.When the pen is up, the pressure-sensitive rubber switch 3 is pressed and conducts. The pressing force of the pressure-sensitive rubber switch 3 is removed, the switch becomes non-conductive again, and no position signal is output.

In conventional coordinate position detection devices, the device signal formed from the input pen is used for both coordinate position detection and pen-down determination. That is, the coordinate detection circuit 4 determines the coordinate position of the input pen from the output position signal, while the level detection circuit 5 determines whether the pen is up or down from the magnitude of the level of the position signal. That is, the pen down signal is output when the level of the position signal is high. However, immediately after pen-down or immediately before pen-up, the output position signal becomes unstable due to chattering of the pressure-sensitive rubber switch 3. Therefore, the conventional coordinate position detection device has a problem in that the coordinate position is detected by determining that the pen is down during the unstable period of the position signal, and as a result, an incorrect coordinate position is output.・In order to solve this problem, as shown in FIG. 7, this pressure sensitive rubber switch 3
A coordinate position detection device has been used in which both ends of the pen are led to a pen down detection circuit 6, and whether or not the pen is down is detected by turning on and off the switch 3.

In the above configuration, the position signal is directly output from the detection probe 2 to the coordinate detection circuit without passing through the pressure-sensitive rubber switch 3, so that no chattering occurs in the position signal. Therefore, the problem of erroneous detection of coordinate positions caused by the chattering described above does not occur.

However, with this configuration, when the detection probe 2 is pushed up, the pressure-sensitive rubber switch 3 is pressed and becomes conductive. When the detection probe 2 is pressed down, the pen-down detection circuit 6 is activated and a pen-down signal is output. Therefore, there is a problem in that noise or the like is detected and a false coordinate position is output even though no position signal is output.

(C1 Object of the Invention The object of the present invention is to provide a coordinate position detection device that is free from the possibility of erroneous detection of coordinate positions due to chattering and erroneous detection at locations other than planar resistors.

(d) Structure of the Invention The present invention is characterized by a planar resistor to which a reference signal is applied between opposing electrodes, and a position signal having a relationship with the reference signal corresponding to position coordinates on the planar resistor. In the configuration, the input pen includes a detection probe and a position detection circuit that detects position coordinates on the planar resistor from the detected position signal. a first output end led out from the detection probe via a pressure-sensitive conductor; It is used as a signal end and a pen-down signal end.

18) Examples of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a cross-sectional view showing the structure of the input pen 1, which is the main part of the present invention. As seen in the figure, the input pen 1 in this embodiment has a detection probe 2, A first output end 11 is led out directly from the detection probe 2 to the outside, and a second output end 12 is led out from the detection probe 2 through a pressure-sensitive conductor such as a pressure-sensitive rubber switch 3. .

In the input pen 1 having such a structure, when the tip of the detection probe 2 is pressed, the pressure-sensitive rubber switch 3 is pressed and becomes conductive. If this operation is performed on the planar resistor, the position signal induced in the detection probe 2 by electrostatic induction or electromagnetic induction will be sent directly from the detection probe 2 to the first output end 11, and to the second output terminal 11. The signal is outputted to the output end I2 via the pressure sensitive rubber switch 3.

During this series of operations, the device signal formed from the first output end 11 gradually increases as the tip of the detection probe 2 approaches the planar resistive plate, and reaches its maximum value when the tip contacts the planar resistive plate. , and since there is no switch involved, no chattering occurs. On the other hand, at the second output end 12, the position signal is output only when the tip of the detection probe 2 is pressed onto the planar resistor, so the position signal at the first output end is output. The start time is delayed, and the position signal output with this delay is input to a pen-down circuit, which will be described later.

Therefore, if the above operation is performed at a location other than the flat resistor, the pressure-sensitive rubber switch 3 will still be pressed and become conductive, but no signal will be induced in the detection probe 2. Therefore, no output appears at either the first or second output terminals 11.12.

This embodiment uses the input pen l having such characteristics as the first one described above.
The second output end is used as a position signal end, and the second output end is used as a pen down signal end.

FIG. 4 is a block diagram showing an embodiment of the present invention constructed using the input pen 1 described above. As shown in the figure, electrodes 14 and 15 are provided on two opposing edges of the planar resistor 13. Although the figure only shows a pair of electrodes arranged in the X direction for convenience of explanation, in reality, a pair of electrodes are also arranged in the Y direction. Reference signals are applied from signal sources 16 and 17 to the pair of opposing electrodes 14 and 15, respectively. Although it is not necessary to specifically limit what kind of reference signal is used, in this embodiment, an example will be described in which alternating current signals of the same frequency and having a certain phase difference are used. That is, the signal source 16,1
Letting the signal outputs of 7 be El and E2, respectively, it is expressed as E1=sinωt E2=sin ((J)t+π/2). Here, ω is the angular frequency, and t is the time [seconds].

In this way, there is always a phase difference of 90 degrees between the electrodes 14 and 15, so at any point on the planar resistor 13,
It has a phase difference α (0≦α≦90 degrees) corresponding to the distance from the electrode 14 with respect to the reference signal at the electrode 14.

When the input pen 1 approaches the flat resistor 13, the detection probe 2
As described above, a position signal having a predetermined phase difference with respect to the reference signal is induced at the tip of the position signal and output to the position signal end (first output end) 11. This output gradually increases as the tip of the detection probe 2 approaches the planar resistor 13.
When the tip comes into contact with the planar resistor 13, it almost reaches the maximum value.

At this time, no output appears at the pen-down signal terminal (second output terminal) 12 yet. When the tip of the detection probe 2 contacts the flat resistor 13 and is further pressed against the flat resistor 13, the pressure-sensitive rubber switch 3 is pressed and conducts, and the position signal is finally sent to the pen-down signal end 12. is output and input to the pen down detection circuit 18. The pen-down detection circuit 18 compares the output signal of the pen-down signal terminal 12 with a predetermined reference value, and outputs a pen-down signal when the reference value is exceeded. Above pen down signal end 12
Of course, there is some chattering in the output signal from the position signal end 11, but at this time the output from the position signal end 11 has already reached its maximum value and is stable, so even if the pen down signal is output during the chattering, it will not be detected. No error occurs in the coordinate position.

Also, when the pen is up, when the pressing force of the detection probe 2 becomes weaker, the pressure-sensitive rubber switch 3 becomes non-conductive before the tip of the detection probe 2 leaves the surface of the flat resistor 13, and the pen-down signal end 12 becomes non-conductive. The output at disappears. Even if chattering occurs at this time, the output of the position signal end 11 is still stable, so no error occurs in the detected coordinate position.

In this way, in this embodiment, the coordinate position can be detected correctly both when the pen is down and when the pen is amplified. Furthermore, even if the detection probe is pressed at a location other than the planar resistor 13, no output will appear at the pen-down signal end 12, so it will not be determined that the pen is down, and therefore a false coordinate position will not be output. do not have.

(f) As described in detail, in the present invention, the first output end 11 directly derived from the detection probe 2 of the input pen is used as a position signal end;
By using the second output end 12 led out through the pressure-sensitive conductor 3 as a pen-down signal end, it was possible to prevent erroneous detection of the coordinate position.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining the difficulties of conventional coordinate position detection devices, and FIGS. 3 and 4 are diagrams showing an embodiment of the present invention, and FIG. 3 is a diagram for explaining the main points of the present invention. FIG. 4 is a cross-sectional view showing a novel input pen, which is a part of the present invention. FIG. In the figure, ■ is an input pen, 2 is a detection probe, 3 is a pressure-sensitive conductor, 4 is a coordinate position detection circuit, 11 is a first output end used as a position signal end, and 12 is a pen down signal end. second output terminal, 13 is a planar resistor, 14 and 15
are electrodes arranged opposite to each other, 16 and 17 are 9
A signal source having the same frequency and a phase difference of 0 degrees, and 18 a pen-down detection circuit. Agent: Patent Attorney Sada Igata -- Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] a planar resistor to which a reference signal is applied between opposing electrodes; an input pen that detects a position signal corresponding to a position coordinate on the planar resistor with respect to the reference signal; and a position detection circuit that detects the position coordinates of the input pen, wherein the input pen includes a detection probe, a first output end directly derived from the detection probe, and a pressure-sensitive conductor from the detection probe. and a second output end derived through the coordinate position detection method, wherein the first output end and the second output end are used as a position signal end and a pen-down signal end, respectively. Device.