JPH10260783A - Touch panel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the mixing-in of noise, to eliminate the charges of the X axis sheet/Y axis sheet of floating, to prevent erroneous detection and to detect accurate pen-down/X coordinate value/Y coordinate value by putting an insulation sheet between a touch panel and an LCD and CRT, etc. SOLUTION: The touch panel 1 is provided with the structure of orthogonally piling up the X axis sheet 11 and the Y axis sheet 12 formed from a resistance film sheet and is provided with the transparent insulation sheet for eliminating the noise under. A controller 2 turns both ends of the X axis sheet 11 of the touch panel 1 provided with the insulation sheet under to an H level, A/D converts the potential of the Y axis sheet 12, compares it with a reference value and detects that pressing is performed. Also, both ends of the X axis sheet 11 are turned to the H level and an L level, the potential of the Y axis sheet 12 is A/D converted and the X coordinate value of a pressed point is detected. Also, both ends of the Y axis sheet 12 are turned to the H level and the L level, the potential of the X axis sheet 11 is A/D converted and the Y coordinate value of the pressed point is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel device comprising two resistive sheets (X-axis / Y-axis) and having a noise removing function.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, an X-axis sheet made of a resistive film sheet and a Y-axis sheet are overlapped at right angles, and a voltage is applied to both ends of the X-axis sheet to form a Y-axis sheet. When both ends are opened and pressed, the potential in the X-axis direction is detected from the Y-axis sheet. When a voltage is applied to both ends of the Y-axis sheet and both ends of the X-axis sheet are opened and pressed, Y is applied.
For example, the potential in the axial direction is detected from the X-axis sheet. At this time, in order to prevent noise from entering the controller 22, a noise filter 24 is inserted in the detection terminal of the X-axis sheet and the detection terminal of the Y-axis sheet, or the noise is removed by connecting a capacitor C25. The erroneous detection due to noise was prevented. Hereinafter, the configuration and operation of FIG. 9 will be described.

FIG. 9 shows an explanatory diagram of the prior art. In FIG. 9, the touch panel 21 has an X-axis sheet and a Y-axis sheet orthogonally stacked.

The controller 22 scans the touch panel 21 to detect the pressed X coordinate value and Y coordinate value, and is composed of an A / D converter 23 and the like.

The A / D converter 23 converts an analog voltage output to a detection terminal of the touch panel 21 into a digital X coordinate value, Y coordinate value, and the like. The filter 24 removes noise.

[0006] The capacitor C25 removes noise. Next, the operation will be described. (1) The controller 22 sets both ends of the X-axis sheet of the touch panel 21 to the H level, detects the voltage output from the Y-axis sheet by the A / D converter 23, and detects that the pen is down when the voltage exceeds a predetermined value. Like that.

(2) The controller 22 sets both ends of the X-axis sheet of the touch panel 21 to H level and L level,
The voltage output from the axis sheet is converted into a digital value by the AD converter 23, and the pressed X-axis coordinate value is detected.

(3) The controller 22 sets both ends of the Y-axis sheet of the touch panel 21 to H level and L level,
The voltage output from the axis sheet is converted into a digital value by the AD converter 23, and the pressed Y-axis coordinate value is detected.

[0009]

As described above, conventionally, a signal line input from the touch panel 21 to the A / D converter 23 of the controller 22 is provided with a filter to prevent noise from passing therethrough, However, there has been a problem that noise cannot be sufficiently removed and erroneous detection is performed. In particular, when the transparent touch panel 21 is directly disposed on an LCD or CRT, the filter or capacitor cannot sufficiently remove the noise due to the influence of the noise from the LCD or CRT, resulting in erroneous detection. There was a problem.

In addition, it is necessary to float the X-axis seed or the Y-axis sheet when detecting the pen down, the X coordinate value and the Y coordinate value. .

The present invention has been made to solve these problems.
Insert an insulating sheet between the touch panel and LCD or CRT to reduce noise contamination, or remove charges from the floating X-axis sheet / Y-axis sheet when detecting pen down / X coordinate value / Y coordinate value. It is another object of the present invention to prevent erroneous detection and detect an accurate pen down / X coordinate value / Y coordinate value.

[0012]

Means for solving the problem will be described with reference to FIGS. 1 and 5. 1 and 5, a touch panel 1 has a structure in which an X-axis sheet 11 and a Y-axis sheet 12 made of a resistive film sheet are orthogonally stacked, and an insulating sheet for removing a transparent noise below. 13.

The controller 2 sets each end of the X-axis sheet 11 and the Y-axis sheet 12 of the touch panel 1 to H level / L.
Level / floating control,
The data is converted into a digital value by the -D converter 3.

The noise determination switching instruction means 6 arbitrarily controls a detection voltage (reference voltage) for determining pen down. Next, the operation will be described.

The controller 2 sets the both ends of the X-axis sheet 11 of the touch panel 1 provided with the insulating sheet 13 below to the H level, converts the potential of the Y-axis sheet 12 from analog to digital, compares it with a reference value, and presses down. , The A-D conversion of the potential of the Y-axis sheet 12 by setting both ends of the X-axis sheet 11 of the touch panel 1 to the H level and the L bell, and the X coordinate value of the pressed point are detected. The potential of the X-axis sheet 11 is set to A−
D conversion is performed and the Y coordinate value of the pressed point is detected.

At this time, the X-axis sheet 11 of the touch panel 1
Are set to the H level, and both ends of the Y-axis sheet 12 are temporarily set to the L level.
After the level is changed to a floating state, the potential is subjected to A / D conversion, and is compared with a reference value to detect that the button is pressed.

Further, both ends of the X-axis sheet 11 of the touch panel 1 are set to the H level and L level, and both ends of the Y-axis sheet 12 are temporarily set to the L level. The X coordinate value of the point is detected.

Further, both ends of the Y-axis sheet 12 of the touch panel 1 are set to the H level and L level, and both ends of the X-axis sheet 11 are temporarily set to the L level. The Y coordinate value of the point is detected.

After detecting the pen down, X coordinate value, and Y coordinate value of the touch panel 1, the next pen down, X
Until the detection of the coordinate value and the Y coordinate value, the X-axis sheet 1
1 and the both ends of the Y-axis sheet 12 are all at L level to reduce noise and save power.

Instead of temporarily setting both ends of the Y-axis sheet 12 to the L level and then bringing the same into a floating state, both ends of the X-axis sheet 11 and both ends of the Y-axis sheet 12 are temporarily set to the L level.
After the level is changed to a floating state, charges on the signal lines and the like are removed.

Further, a reference value for detecting that the noise determination switch instructing means 6 is pressed is set to an arbitrary value so that pen down can be accurately detected without erroneous detection.

Therefore, the touch panel 1 and the LCD or CRT
By inserting an insulating sheet 13 between them and reducing the mixing of noise, or by removing the electric charge of the floating X-axis sheet 11 and Y-axis sheet 12 when detecting the pen down / X coordinate value / Y coordinate value. It is possible to detect an accurate pen down / X coordinate value / Y coordinate value while preventing erroneous detection.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments and operations of the present invention will be described sequentially in detail with reference to FIGS.

FIG. 2 is a diagram for explaining pen-down detection according to the present invention. This shows a procedure for detecting when the pen is down on the touch panel 1 in the configuration of FIG. FIG. 2A shows a signal level.

X-axis right control line (XR): H level X-axis left control line (XL): H level Y-axis upper control line (YU): Hi level (floating) Y-axis lower control line (YD ): Hi level (floating) PD: L level This is the XR of the X-axis sheet 11 of the touch panel 1 in FIG.
And XL to H level, YU and YD of Y axis sheet 12 to Hi
(Floating), and the PD terminal of the controller 2 is set to L level.

FIG. 2B shows a detection signal. In order to detect the pen down, the X-axis sheet 11 is set to the H level by setting the signal level in FIG. 2A and the Y level in the floating state due to the pen down, as schematically shown in FIG. 2B. The Y-axis sheet 1 contacts the axis sheet 12
2 is connected to the L level of the PD via the resistor R1. Here, RT is the total resistance from the X-axis sheet 11 of the touch panel to the resistance R1. And the resistance RT
Potential of ADX at the connection point of the resistor and the resistor R1 (expressed by the following formula)
Is detected by the A / D converter 3 and compared with a specified value (which can be arbitrarily set in FIG. 7).

ADX = (R1) / (R1 + RT) Equation 3 FIG. 3 is an explanatory diagram of X coordinate detection according to the present invention. This shows a procedure for detecting the X coordinate value of the pressed point on the touch panel 1 under the configuration of FIG.

FIG. 3A shows a signal level. X-axis right control line (XR): H level X-axis left control line (XL): L level Y-axis upper control line (YU): Hi level (floating) Y-axis lower control line (YD): Hi Level (floating) PD: Hi level (floating) This is the XR of the X-axis sheet 11 of the touch panel 1 in FIG.
And XL to H level and L level, YU and YD of Y axis sheet 12 to Hi (floating), and controller 2
Is set to Hi (floating).

FIG. 3B shows a detection signal. In order to detect the X coordinate value, by setting the signal level in FIG. 3A, as shown schematically in FIG. 3B, XR of the X-axis sheet 11 is H level and XL is L level. As a result, the X potential (expressed by the following equation) at the pressed point is transmitted by touching the Y-axis sheet in the floating state by being pressed, and the X-coordinate value of the digital is detected by the AD converter 3.

ADX = (RX2) / (RX1 + RX2) Expression where RX1 represents a resistance value between a pressing point of the X-axis sheet 11 and a point of the H level potential, and RX2 represents X. It represents the resistance value between the pressed point of the shaft sheet 11 and the point of the L level potential.

FIG. 4 is a diagram for explaining the detection of the Y coordinate of the present invention. This shows a procedure for detecting the Y coordinate value of the pressed point on the touch panel 1 in the configuration of FIG. FIG. 4A shows a signal level.

X-axis right control line (XR): Hi level (floating) X-axis left control line (XL): Hi level (floating) Y-axis upper control line (YU): H level Y-axis lower control Line (YD): L level PD: Hi level (floating) This is the YU of the Y axis sheet 12 of the touch panel 1 in FIG.
And YD at H level and L level, XR and XL of X-axis sheet 11 at Hi (floating), and controller 2
Is set to Hi (floating).

FIG. 4B shows a detection signal. In order to detect the Y coordinate value, by setting the signal level of FIG. 4A, as shown schematically in FIG. 4B, YU of the Y-axis sheet 12 is at H level and UD is at L level. When the button is pressed, it comes into contact with the floating X-axis sheet 11 to transmit the Y potential (expressed by the following formula) at the pressed point, and the A / D converter 3 detects the digital Y coordinate value.

ADY = (RY2) / (RY1 + RY2) where RY1 represents a resistance value between the point at which the Y-axis sheet 12 is pressed and the point at the H level potential, and RY2 is Y. It represents the resistance value between the point where the shaft sheet 12 is pressed down and the point of the L level potential.

FIG. 5 shows an example of the insulating sheet of the present invention. FIG. 5A shows a sectional view. This is an LCD or CRT
When the touch panel 1 is placed on the
Insulating sheet 13 for noise removal on D or CRT 14
And a Y-axis sheet 1 on which a touch panel 1 is provided
2. An X-axis sheet 11 is provided. As described above, the insulating sheet 13 is provided with the LCD or CRT 14 and the Y-axis sheet 1.
LCD and CRT provided between 2 and X-axis sheet 11
This eliminates the situation in which the noise generated by the noise 14 (noise in FIG. 5B) is mixed into the Y-axis sheet 12 and the X-axis sheet 11 to make the detection position inaccurate.

FIG. 5B shows an example of the LCD noise waveform. The LCD has driving noise as shown, and without the insulating sheet 13 shown in FIG. 5A, the noise is generated by the Y-axis sheet 12 and the X-axis sheet 1 constituting the touch panel 1.
1, especially when the signal enters a floating state, and the mixed signal is converted into an X coordinate value or a Y coordinate value by the A / D converter 3, so that it appears as an error in the detection position. Will be incorrect. The present invention
In order to prevent such a detection position from becoming inaccurate, an insulating sheet 13 is provided between the LCD or CRT 14 and the Y-axis sheet 12 and the X-axis sheet 11 constituting the touch panel 1 so that the noise is particularly low in the floating state. Shaft sheet 1
1 or the Y-axis sheet 12 so as not to be mixed.

FIG. 6 is an explanatory diagram of the noise removing method of the present invention. This means that the electric charge accumulated in the X-axis sheet 11 and the Y-axis sheet 12 of the touch panel 1 is detected by pen-down detection,
The removal is performed immediately before the detection of the X coordinate value and the detection of the Y coordinate value, thereby eliminating the erroneous detection of the pen down detection due to the electric charge and the incorrect detection of the X coordinate value and the Y coordinate value.

In the case of XR, XL, XL, YU, YD, and PD are all set to L level to remove (discharge) electric charges.
Sets XR, XL, YU, YD, and PD as shown in FIG. 2A described above in order to detect pen-down. Here, all are set to L level to remove charges immediately before (only YU and YD may be set to L level to remove charges. If all are set to L level, charges are removed. In addition, power saving can be achieved).

XR: H level XL: H level YU: Hi level YD: Hi level PD: L level The YU and YD are set to L level to remove charges.

In order to detect the X-coordinate value by scanning the X-axis, XR, XR as shown in FIG.
L, YU, YD, PD are set as follows. XR: H level XL: L level YU: Hi level YD: Hi level PD: Hi level XR and XL are set to L level to remove electric charge.

In order to detect the Y coordinate value by scanning the Y axis, XR and XR are used as shown in FIG.
L, YU, YD, PD are set as follows.・ XR: Hi level ・ XL: Hi level ・ YU: H level ・ YD: L level ・ PD: Hi level A series of pen down detection, X coordinate value detection, and Y coordinate value detection are completed It is done. Then, the process waits, and the following pen-down detection, X-coordinate value detection, and Y-coordinate value detection are repeated in the order of. Accordingly, it is possible to accurately detect pen-down by removing electric charges immediately before pen-down detection, immediately before X-coordinate value detection, and immediately before Y-coordinate value, and to increase detection accuracy of X-coordinate value and Y-coordinate value. Becomes possible.

FIG. 7 is a flowchart for setting a pen down detection voltage according to the present invention. This corresponds to FIG.
7 is a flowchart for appropriately setting a prescribed value (reference value) for comparing with the pen-down detected voltage ADX to determine whether the pen is down.

In FIG. 7, in step S1, it is determined whether or not detection is performed without pen down. If YES, S
At 2, the detection voltage is increased, the process returns to S1, and the process is repeated. In the case of NO, the process proceeds to S3.

In step S3, the pen goes down. In S4, it is determined whether or not the pen down is detected. In the case of OK, the detection voltage (FIG. 2)
(B), the reference voltage for comparing the presence or absence of pen-down is determined to be appropriate, and the detection voltage is set (updated) in S5, and the processing ends (END). On the other hand, N of S4
In the case of G, the detection voltage is reduced in S6, and the process returns to S1 and repeats.

As described above, it is possible to appropriately set the detection voltage (reference voltage) when the noise determination switching instructing means 6 in FIG. 1 detects the pen down state by comparing with ADX in FIG. 2B. It becomes possible.

FIG. 8 is a diagram for explaining a measure for removing noise when the pen is down according to the present invention. Here, RT and R1 represent RT and R1 shown in FIG. The H level and L level represent the H level and L level potentials of FIGS. The shaded area is the pen-down detection range, and the potential of the pen-down is equal to or higher than this detection range.
When X is reached, pen down is detected. At this time, a positive noise is added to the L level, and a negative noise is added downward from the potential of the ADX at the time of pen down, and a hatched portion between them is a pen down detection range, which is not affected by the noise. It is.

Therefore, when the above-described detection voltage (specified voltage, reference voltage) of FIG. 7 is set substantially at the center of the pen-down detection range indicated by the hatched portion in FIG. The pen down can be detected.

[0048]

As described above, according to the present invention,
An insulating sheet 13 is inserted between the touch panel 1 and the LCD, CRT, or the like to reduce the noise, or to detect the charge of the floating X-axis sheet 11 or Y-axis sheet 12 when detecting the pen down / X coordinate value / Y coordinate value. To eliminate false detection of pen down,
Moreover, an accurate X coordinate value / Y coordinate value can be detected. The X-axis sheet 11 and the Y-axis sheet 12
R, XL, YU, YD, and PD are set to L level to remove electric charge to accurately detect pen down / X coordinate value / Y coordinate value, and to save power.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of the present invention.

FIG. 2 is an explanatory diagram of pen-down detection of the present invention.

FIG. 3 is an explanatory diagram of X coordinate detection according to the present invention.

FIG. 4 is an explanatory diagram of Y coordinate detection according to the present invention.

FIG. 5 is an example of an insulating sheet of the present invention.

FIG. 6 is an explanatory diagram of a noise removing method according to the present invention.

FIG. 7 is a flowchart for setting a pen down detection voltage according to the present invention.

FIG. 8 is an explanatory diagram of noise countermeasures at the time of pen down according to the present invention.

FIG. 9 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1: Touch panel 2: Controller 3: A / D converter 4: Capacitor C 5: Filter 6: Switching instruction means for noise judgment 11: X-axis sheet 12: Y-axis sheet 13: Insulation sheet 14: LCD / CRT

Claims (7)

[Claims] 1. A touch panel having a structure in which an X-axis sheet and a Y-axis sheet made of a resistive film sheet are orthogonally stacked, an insulating sheet disposed under the touch panel for removing noise, and an X-axis of the touch panel Means for setting both ends of the sheet to the H level, performing A / D conversion of the potential of the Y-axis sheet, comparing the potential with a predetermined value, and detecting that the sheet has been pressed; Means for AD-converting the potential of the Y-axis sheet and detecting the X-coordinate value of the pressed point; and setting the both ends of the Y-axis sheet of the touch panel to H level and L level to set the potential of the X-axis sheet. Means for performing A / D conversion and detecting a Y coordinate value of a pressed point. 2. Both ends of the X-axis sheet of the touch panel are H
Level, set both ends of the Y-axis sheet to L level once, and then to a floating state to A / D convert the potential,
2. The touch panel device according to claim 1, further comprising: means for comparing the value with a predetermined value to detect that the button is pressed. 3. Both ends of the X-axis sheet of the touch panel are H
After setting both ends of the Y-axis sheet to L level once and then to L level, the floating state is set to A-D
3. The touch panel device according to claim 1, further comprising means for converting and detecting an X coordinate value of a pressed point. 4. Both ends of the Y-axis sheet of the touch panel are H
After setting both ends of the X-axis sheet to the L level once and the L level, the floating state is established and the potential is set to AD.
4. The touch panel device according to claim 1, further comprising means for converting and detecting a Y coordinate value of a pressed point. 5. From the pen down, X coordinate value and Y coordinate value detection of the touch panel to the next pen down, X coordinate value and Y coordinate value detection, both ends of the X axis sheet and Y coordinate are detected. The touch panel device according to any one of claims 1 to 4, wherein both ends of the shaft sheet are set to L level to reduce noise and save power. 6. Instead of temporarily setting both ends of the Y-axis sheet according to claim 2 to L level and then bringing them into a floating state, both ends of the X-axis sheet and both ends of the Y-axis sheet are temporarily set to L level. A touch panel device, wherein the touch panel device is set in a floating state after the touch panel. 7. The touch panel device according to claim 2, further comprising means for setting the predetermined value to an arbitrary value when detecting that the button is pressed.