JP2512936B2 - Matrix switch / sense device - Google Patents

Description

The present invention relates to a sense device for a matrix switch, in which a plurality of sense lines and a plurality of drive lines each having a predetermined width are arranged in a matrix.

[Prior Art] Conventionally, as a sensing device for detecting a touched portion, as shown in FIG. 5, a plurality of sense lines and drive lines having a predetermined width are arranged in a matrix and sequentially scanned and scanned. There is known a matrix switch / sense device or the like that digitally detects a touched portion.

On the other hand, as shown in FIG. 6, by arranging two films having thin film resistors formed so as to face each other and using each of them as a driving layer and a sense layer, the resistance value changes depending on the touched portion. There is also known an analog type sensing device or the like that detects the vertical position and the horizontal position based on the detected voltage value and the like.

As an invention and a proposal regarding the sensing device, etc.,
The "matrix switch sense method" shown in 59-216234 is known.

[Problems to be Solved by the Invention] Although the above-described conventional sensing device has an excellent effect of being able to preferably detect a touched portion, the following problems have been considered.

That is, in a matrix switch sense device including a plurality of sense lines and drive lines, there is a problem that the resolution is determined by the number of sense lines and drive lines. Therefore, if an attempt is made to increase the resolution, there may be a problem that the structure becomes complicated in proportion to the height of the resolution, the number of parts is increased, or even if the resolution is set high, the resolution may be low. There was a problem such as lack of versatility.

On the other hand, in the analog type sensing device, the vertical position and the horizontal position of the touched portion are detected based on the voltage drop according to the change in resistance value depending on the contact position between the films on which the thin film resistor is formed. Therefore, it is necessary to make the film thickness of the thin film resistor uniform. However, a single film having a large area may have a part where the film thickness of the thin-film resistor is not uniform, and in such a case, there is a gap between the detected touch location and the actual touch location. If an error occurs or if two or more points are pressed at the same time, it cannot be detected that two or more points are pressed (that is, it is treated as pressing only one point), and an incorrect pressing position is detected, etc. The problem was considered.

The matrix switch sense device of the present invention has been made for the purpose of solving the above problems and providing a more versatile matrix switch sense device.

Configuration of the Invention [Means for Solving the Problems] The matrix switch sense device of the present invention is
A sense device of a matrix switch in which a plurality of sense lines and a plurality of drive lines each having a predetermined width are arranged in a matrix at regular intervals, as illustrated in the basic configuration of the figure. And scan detection means (M1) for digitally detecting by sequentially scanning and scanning a specific area including a portion where the sense line and the drive line are in contact with each other, which is formed by overlapping the drive line and the specific line. Analog detection means (M2) for detecting the contact point in the specific area from each analog electric signal detected from each of the sense line and the drive line forming the area, and .

[Operation] The matrix switch sense device of the present invention having the above structure operates as follows.

The matrix switch / sense device of the present invention includes a scan detection unit (M) that detects a specific area formed by overlapping the sense line and the drive line including a portion where the sense line and the drive line are in contact with each other by being touched.
1) sequentially scans and detects, and from the analog electric signals detected from each of the sense line and the drive line forming the specific area, the analog detection means (M2) detects the contact point in the specific area. Works to detect.

[Embodiment] Next, a preferred embodiment will be described with reference to the drawings in order to further clarify the configuration of the matrix switch sense device of the present invention.

As shown in FIG. 2, the matrix switch / sense device of this embodiment mainly includes CPU1, ROM2, RAM3, etc., and an analog / digital converter (hereinafter, simply referred to as A / D converter) 4 and an external device. An electronic control unit 7 as a logical operation circuit in which the interface circuit 5 and the like are connected to each other by a common bus 6, and a plurality of predetermined widths (2.0 cm in this embodiment)
Of the drive lines x1 to xn and the sense lines y1 to yn, and the selection switching circuits 15 to 18 and the selection switching circuit 15 which are used when the scan scanning of the matrix switch 10 is performed.
A power source switching circuit 20 for supplying a power source of a predetermined voltage to the drive lines x1 to xn or the sense lines y1 to yn via a reference voltage source 21 and the like. Where the drive line
x1 to xn and sense lines y1 to yn are oxide indium (so-called IT
O), one of both ends of each of the drive lines x1 to xn is a selection switching circuit 15 and the other of each of the ends is a selection switching circuit 16, and similarly, one of both ends of each of the sense lines y1 to yn. Is connected to the selection switching circuit 17, and the other end of each is connected to the selection switching circuit 18.

The selection switching circuits 15 and 17 are so-called multiplexers and demultiplexers, and similarly, the selection switching circuits 16 and 18 are
Demultiplexer, each consisting of signal lines 25 to 28
It is directly connected to each of the CPU 1 of the electronic control unit 7 via. The selection switching circuit 15 is connected to the power supply side of the reference power supply 21 via the signal line 30 and the switch 20a of the power supply switching circuit 20, and the selection switching circuit 17 is connected to the power supply side of the reference power supply 21 via the signal line 31 and the switch 20b. Similarly, the selection switching circuit 16 includes a signal line 32 and a switch 20c.
Via the signal line 33 and the switch 20d.
Are connected to the ground side of the reference power source 21 via the and. The output side of the selection switching circuit 16 is the A / D converter 4 of the electronic control unit 7 via the signal line 34, and the output side of the selection switching circuit 17 is the CPU 1 and the A / D conversion via the signal line 35. Connected to the container 4. Further, the power supply switching circuit 20 includes a signal line 36
It is directly connected to CPU1 via.

The operation of the present embodiment having the above configuration will be described with reference to the flowchart of the "touch position detection process" shown in FIG.

First, when the matrix switch / sense device of the present embodiment is powered on, initialization such as clearing the value of RAM3 is executed (step S100), and then the digital scan processing SKN corresponding to the scan detection means. Is executed (steps S110 to S130).

That is, the CPU 1 turns on the switches 20b and 20c of the power supply switching circuit 20 via the signal line 36, switches the selection switching circuit 17 via the signal line 26, and sequentially applies a predetermined voltage to the sense lines y1 to yn. Is applied. Further, at this time, the CPU 1 switches the selection switching circuit 16 via the signal line 27 and inputs the signal via the signal line 35 while applying a voltage to any one of the sense lines y1 to yn. Sense line y1 or
Processing for determining the voltage level of yn is performed. As a result, the plurality of drive lines x1 to xn and the plurality of sense lines y1 to xn
yn and a matrix switch with a predetermined resolution
It is possible to detect the touch position (pressed position) on 10. A pull-up resistor (not shown) is connected to the signal line 31.

On the other hand, the digital scan processing SKN (step S110
Through S130), the pressed position detected by the above-mentioned predetermined resolution is required (step S140), the analog detection process AN corresponding to the analog detection means is subsequently executed.
G is executed (steps S150 to S170).

Now, for example, if a point P1 on the matrix switch 10 shown in FIG. 2 is pressed, the CPU 1 firstly presses the pressed position P detected by the digital scan processing SKN.
The drive line x2 and the sense line y2 corresponding to 1 are stored in the RAM 3 as position coordinates (addresses) (step S1
50). After this, the CPU1 drives the drive line x2 as shown in FIG.
And the sense line y2 are overlapped with each other, the pressing position P1 is detected from the specific area are (steps S160 to S170).

That is, the CPU 1 has the switches 20b and 20d of the power supply switching circuit 20.
After turning on the switch and turning off the switches 20a and 20c,
The selection switching circuits 17 and 18 are switched to apply a predetermined voltage only to the sense line y2, and the selection switching circuits 15 and 16 are switched to convert the analog electric signal detected from the drive line x2 to the signal line 34 and the A / D converter 4 Input via (step 160). Similarly, the CPU 1 turns on the switches 20a and 20c of the power supply switching circuit 20 and turns off the switches 20b and 20d, and then switches the selection switching circuits 15 and 16 to apply a predetermined voltage only to the drive line x2. Switch the selection switching circuits 17 and 18 to sense line
The analog electrical signal detected from y2 is converted to signal line 35 and A /
Input through the D converter 4 (step 170). By this analog detection processing ANG, the address of the x and y coordinates of the pressed position P1 is detected with higher resolution from the specific area are. Incidentally, FIG. 4 shows an equivalent circuit for obtaining the x coordinate of the depressed position P1.

In the following process step S180, the address obtained by the digital scan process SKN and the analog detection process ANG are obtained.
It is confirmed whether or not the address obtained in step S1 is the same, that is, whether the address obtained in the analog detection process ANG is located in the specific area are obtained in the digital scan process SKN.

If an affirmative decision is made in step S180, the address of the high-resolution pressing position P1 obtained by the analog detection processing ANG is set to the above-mentioned step S1.
If a negative decision is made at 40, the address of the predetermined resolution obtained by the digital scan processing SKN is
A process for outputting to a display device such as a CRT display device (not shown) through the external interface circuit 5 is performed (step
S190). After this, or when a negative determination is made in step S130 or step S180, the process returns to step S110.

As described above, according to the matrix switch / sense device of the present embodiment described in detail, it is possible to selectively use the digital scan process of the predetermined resolution and the analog detection process of the high resolution with a simple configuration, which is extremely versatile and excellent. Have an effect. As a result, it is not necessary to configure the resolution of the digital scan process to be high, and the film thickness can be made uniform for each drive line and sense line having a predetermined width. Further, even if the drive line or the sense line has a non-uniform portion in film thickness, the address of the pressed position detected by the analog detection process is compared with the position detected by the digital scan process. Therefore, there is an excellent effect that the detected pressed position can be more reliable. Furthermore, since both digital scan processing and analog detection processing can be performed, it is possible to detect that two or more points have been pressed during the digital scan processing, and prevent misidentification as if one point was pressed. It also has the effect of being able to.

The matrix switch / sense device of the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the scope of the present invention.

EFFECTS OF THE INVENTION According to the matrix switch sensing device of the present invention, the scan detecting means (M1) having a predetermined resolution and the analog detecting means (M2) having a high resolution can be selectively used with a simple structure, which is extremely versatile. Has excellent effect. This eliminates the need to configure the scan detection means (M1) with high resolution, and has an excellent effect that the film thickness may be made uniform for each drive line and sense line having a predetermined width. In addition, even if the drive line or the sense line has a non-uniform thickness, the pressed position detected by the analog detection means (M2) is the same as the position detected by the digital detection means (M1). It is possible to make a comparison, and there is also an excellent effect that the detected pressed position can be more reliable. Furthermore,
Since the digital detection means (M1) and the analog detection means (M2) can be performed together, the digital detection means (M1)
Therefore, it is possible to detect that two or more points are pressed, and it is possible to prevent the analog detection means (M2) from erroneously recognizing that one point is pressed.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of a matrix switch sensing device of the present invention, FIG. 2 is a schematic configuration diagram showing a matrix switch sensing device of one embodiment of the present invention, and FIG. FIG. 4 is an equivalent circuit diagram showing a circuit for obtaining the x-coordinate of the depressed position P1, FIG. 5 is an explanatory diagram showing a matrix switch of a conventional matrix switch sensing device, and FIG. 6 is a conventional diagram. It is an explanatory view for showing the structure of an analog type sensing device. 7 ... Electronic control unit 10 ... Matrix switch 20 ... Power supply switching circuit

Claims (1)

(57) [Claims] 1. A sense device of a matrix switch, in which a plurality of sense lines and a plurality of drive lines each having a predetermined width are arranged in a matrix at regular intervals, wherein the sense lines and the drive lines overlap each other. Scan detection means for sequentially scanning and scanning a specific area including a portion where the sense line and the drive line are in contact with each other, and each of the sense line and the drive line forming the specific area. A matrix switch sense device, comprising: an analog detection unit that detects the contact point in the specific area from each analog electric signal detected from the analog switch.