JPH10260771A - Data transfer device for touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dissolve the situation of generating the omission of coordinate data at the time of the coordinate detection of a touch panel and character recognition and to normally perform an operation by preparing the difference of the coordinate data of an X coordinate value and a Y coordinate value detected from the touch panel and saving it in a buffer memory. SOLUTION: An A/D converter 2 A/D converts a value corresponding to the X coordinate of a pressing point and the value corresponding to a Y coordinate detected from the touch panel 1 and a touch panel controller 3 obtains X difference data and Y difference data based on the converted X coordinate value and Y coordinate value and temporarily stores the obtained X difference data and Y difference data in the buffer memory 4. Then, the original X coordinate value and Y coordinate value are respectively reproduced based on the X difference data and the Y difference data taken out from the buffer memory 4. Along with that, the X coordinate value and the Y coordinate value converted by the A/D converter 2 or the reproduced X coordinate value and Y coordinate value are transferred to the CPU 5 of a transfer request origin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel data transfer device for detecting and transferring an X coordinate and a Y coordinate of a pressed point on a touch panel.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, a resistive touch panel has an X sheet having a number of resistance lines arranged in an X-axis direction and a Y sheet having a number of resistance lines arranged in a Y-axis direction. Are applied orthogonally to each other, a voltage is applied to both ends of the X-axis, a voltage corresponding to the resistance value of the X-axis corresponding to the point where the Y-axis is opened and pressed is detected from the opened Y-axis,
A voltage is applied to both ends of the axis, and the X-axis is released and the voltage corresponding to the resistance value of the Y-axis corresponding to the pressed point is released.
Detect from axis. The voltage corresponding to the former X-axis pressing point and the latter corresponding to the Y-axis pressing point are converted by the AD converter 2.
2 to a value using 2 bytes (a value using 10 to 12 bits in 2 bytes), and the touch panel controller 23 transfers the total 4 bytes of data to the CPU 25, or the CPU 25 Sometimes, it is temporarily saved in the buffer memory 24,
When the CPU 25 enters the operating state, the buffer memory 2
The 4-byte X coordinate and Y coordinate values extracted from 4 were transferred.

[0003]

Therefore, when the CPU 25 is busy or stopped in the configuration of FIG. 7, two bytes each of the X-axis and the Y-axis are used for each of the pressed points on the touch panel 21.
It is necessary to save a total of 4 bytes of data in the buffer memory 24. To save a large amount of coordinate data, the capacity of the buffer memory 24 becomes large.

[0004] The capacity of the buffer memory 24 provided in the touch panel controller 23 is limited, and there is a problem that so much 4-byte coordinate data cannot be saved. For this reason, if the coordinate data to be retracted from the touch panel 21 becomes large, the coordinate data cannot be retracted to the buffer memory 24, and the coordinate data will be lost in the middle. Problem occurs.

[0005] The present invention solves these problems,
Creates difference data for the X coordinate and Y coordinate data detected from the touch panel and saves the data to the buffer memory. A large amount of coordinate data is saved to the same buffer memory to realize coordinate data for touch panel coordinate detection and character recognition. The purpose of the present invention is to solve the problem of the occurrence of toothlessness and to operate normally.

[0006]

Means for solving the problem will be described with reference to FIG. In FIG. 1, the touch panel 1 outputs values (here, voltage values) corresponding to the X coordinate and the Y coordinate of the pressed point.

The A / D converter 2 converts analog values corresponding to the X and Y coordinates of the pressed point output from the touch panel 1 into digital values. The touch panel controller 3 performs various controls for notifying the CPU 5 of the X coordinate value and the Y coordinate value of the pressed point of the touch panel 1.
With

The buffer memory 4 temporarily stores difference data of the X coordinate and the Y coordinate when the touch panel 1 is pressed. The CPU 25 requests transfer of the X coordinate value and the Y coordinate value of the pressed point on the touch panel 1.

Next, the operation will be described. The A / D converter 2 A / D converts the value corresponding to the X coordinate and the value corresponding to the Y coordinate of the pressed point detected from the touch panel 1, and the touch panel controller 3 converts the X value converted by the A / D converter 2. X difference data and Y difference data are obtained based on the coordinate value and the Y coordinate value.
The difference data is temporarily stored in the buffer memory 4, the original X coordinate value and the Y coordinate value are respectively reproduced based on the X difference data and the Y difference data extracted from the buffer memory 4, and the A / D converter is used. X converted by 2
The coordinate value and the Y coordinate value or the reproduced X coordinate value and the Y coordinate value are transferred to the transfer requesting CPU 1.

At this time, the difference between the previous X coordinate value and the current X coordinate value and the difference between the previous Y coordinate value and the current Y coordinate value are determined as the X difference data and the Y difference data. .

Further, as the X difference data and the Y difference data, when the difference between the previous X coordinate value and the current X coordinate value is within a predetermined value, or the difference between the previous Y coordinate value and the current Y coordinate value, The X difference data and the Y difference data are output when the difference is within a predetermined value.

Further, two bytes are used for the X coordinate value and the Y coordinate value, and one byte is used for the X difference data and the Y difference data, so that the buffer memory 4 is effectively used twice as much as the conventional one.

Only when the transfer requesting CPU 1 cannot receive the X coordinate value and the Y coordinate value, the X difference data based on the X coordinate value and the Y coordinate value converted by the A / D converter 2 are obtained. And Y difference data to generate the buffer memory 4
When the transfer requesting CPU 1 is ready to receive, the original X coordinate value and Y coordinate value are reproduced from the buffer memory 4 based on the X difference data and Y difference data and transferred. I am trying to do it.

Further, based on the X coordinate value and the Y coordinate value converted by the AD converter 2, X difference data and Y
The difference data is generated and stored in the buffer memory 4, and the original X coordinate value and Y coordinate value are reproduced from the buffer memory 4 and transferred based on the X difference data and the Y difference data.

Further, the touch panel 1 detects a voltage at an intersection where a sheet provided with a plurality of resistance lines in the X coordinate direction and a sheet provided with a plurality of resistance lines in the Y coordinate direction are overlapped and pressed. The voltage is converted into an X coordinate value and a Y coordinate value by the AD converter 2 and output.

Therefore, the difference data of the coordinate data of the X coordinate and the Y coordinate detected from the touch panel 1 is created and saved in the buffer memory 4, and is stored in the buffer memory 4.
The original X-coordinate value and Y-coordinate are reproduced based on the difference data extracted from the transfer data and transferred to the transfer requester, so that a large amount of coordinate data is saved in the same buffer memory 4 and the coordinate detection of the touch panel 1 is performed. It is possible to eliminate a situation in which coordinate data is missing at the time of character recognition or character recognition, and to operate normally.

[0017]

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

FIG. 2 is a flowchart illustrating the operation of the present invention. This explains the overall operation of the configuration of FIG. 1 in detail. In FIG. 2, S1 performs X-axis AD conversion. Specifically, the analog voltage value of the X coordinate detected from the touch panel 1 of FIG. 1 is converted into a digital X coordinate value by the AD converter 2.

In step S2, it is determined whether the difference between the previous time and the current time is equal to or more than a predetermined value. This is because the difference between the X coordinate value after the A / D conversion by the A / D converter 2 and the previous X coordinate value is within a predetermined value (for example, within 2 bits in binary, that is, in decimal). (“4” or less). If YES, S
Proceed to 4. In the case of NO, the noise is deleted in S3 and the process returns to S1 and is repeated.

In step S4, Y-axis AD conversion is performed. this is,
The analog voltage value of the Y coordinate detected from the touch panel 1 in FIG. 1 is converted into a digital Y coordinate value by the AD converter 2.

In step S5, it is determined whether the difference between the previous time and the current time is within a predetermined value. This is because the difference between the Y coordinate value after A / D conversion by the A / D converter 2 and the previous Y coordinate value is within a predetermined value (for example, within 2 bits in binary, that is, in decimal). (“4” or less). If YES, S
Proceed to 6. In the case of NO, the noise is deleted in S3 and the process returns to S1 and is repeated.

In step S6, the amount of change in the X axis is calculated. In this case, the change amount (X difference data) is obtained by subtracting the current X coordinate value from the previous X coordinate value. In step S7, the amount of change (X difference data) is set in the buffer memory 4. here,
As will be described later, since the change amount (X difference data) has a 1-byte configuration, the change amount (X difference data) is stored in a 1-byte area of the buffer memory 4, and the memory capacity is half that of the conventional case. I'm done.

In step S8, the amount of change in the Y axis is calculated. In this method, the change amount (Y difference data) is obtained by subtracting the current Y coordinate value from the previous Y coordinate value. In step S9, the amount of change (Y difference data) is set in the buffer memory 4. here,
As will be described later, since the change amount (Y difference data) has a 1-byte configuration, the change amount (Y difference data) is stored in a 1-byte area of the buffer memory 4, and the memory capacity is half that of the conventional case. I'm done.

In step S10, conversion for transferring data to the CPU is performed. This is because the buffer memory 4 in S7 and S9
(X difference data) and change amount (Y
1-byte data is taken out as difference data) and converted into 2-byte data of the original X coordinate value and Y coordinate value.

In step S11, data is transferred to the CPU. This transfers the data returned to the original 2-byte X coordinate value and Y coordinate value in S10 to the CPU 1. By the above,
X coordinate and Y of the pressed point pressed on touch panel 1
The coordinates are converted by the AD converter 2 into an X coordinate value and a Y coordinate value using two digital bytes, and the X coordinate value and the Y coordinate value are changed by one byte from the previous coordinate value ( Difference data) to obtain the buffer memory 4
And the 1-byte change amount (difference data) extracted from the buffer memory 4 is returned to the X-coordinate value and the Y-coordinate value using the original 2 bytes, and is transferred to the CPU 1. A large amount of change (X difference data, Y difference data) can be saved by doubling the usage efficiency of the conventional one, and the situation where the coordinate data is missing during coordinate detection and character recognition on the touch panel 1 is eliminated and operates normally. It is possible to do.

FIG. 3 shows a format example of coordinate data of the touch panel of the present invention. FIG. 3A shows coordinate data (X axis / Y axis). This coordinate data (X axis / Y
(Axis) is a value obtained by digitally converting the voltage values corresponding to the X coordinate and the Y coordinate output from the touch panel 1 by the A / D converter 2 and is 12 bits (2 bits) as shown in FIG. Bit). 4 on the LSB side
Bits are unused.

FIG. 3B shows a change value (X axis / Y axis). The change value (X-axis / Y-axis) is the change amount (X-axis / Y-axis) between the previous coordinate data (X-axis / Y-axis) in FIG. / Y axis) and 1
It is expressed by 8 bits as shown using bytes. Here, all bits of one byte are used. With this, 2-byte coordinate data (X axis / Y axis)
Means that the data amount can be reduced by half to the change amount of one byte (X axis / Y axis). Therefore, the change amount (X axis / Y
Axis) is stored in the buffer memory 4, and if the capacity of the buffer memory 4 is the same, twice as many coordinate data (X-axis / Y-axis) can be saved, and the coordinate detection and character recognition of the touch panel 1 can be performed. Occasionally, the situation where the coordinate data is missing can be resolved and normal operation can be performed.

FIG. 3C shows a state in which the coordinate data is restored. This returns the amount of change of one byte (X axis / Y axis) in FIG. 3B to the original coordinate data (X axis / Y axis) using two bytes. The coordinate data (X axis / Y axis) using the returned 2 bytes is transferred to the CPU 5.

FIG. 4 shows a mode example of the system of the present invention. This is the C of FIG. 1 of the battery operated notebook PC.
This is an example of the mode of the PU 5 and includes three modes: an operation mode, a pseudo operation mode, and a suspend mode.

The operation mode is a mode in which the CPU operates and the display is ON. The pseudo operation mode is a mode in which the CPU is stopped and the display is ON, and it appears that the CPU is operating from the outside, and the CPU is stopped to save power. When the touch panel 1 is pressed in the pseudo operation mode, the mode is changed to the operation mode. At this time, when transitioning to the operation mode, a processing time for activating the CPU 5 is required, and during this processing time (S22 and S2 in FIG. 5).
3) The coordinate values (X-axis / Y-axis) from the touch panel 1 are saved in the buffer memory 4 as change amounts (X-axis / Y-axis),
When the CPU 5 transitions to the operation mode, the change amount (X-axis / Y-axis) is extracted from the buffer memory 4 and returned to the original coordinate value (X-axis / Y-axis) and transferred to the CPU 5.

In the suspend mode, the CPU stops,
This is a mode in which the display is OFF and a mode in a standby state. FIG. 5 shows an example of a time chart according to the present invention. This is a time chart when the operation mode, the pseudo operation mode, and the suspend mode of the CPU 5 in FIG. 4 are changed.

In FIG. 5, the mode of the system is shown in FIG.
, The pseudo operation mode, and the suspend mode. The CPU is the CPU of FIG.
5 represents the operation state. ON indicates an operation, and OFF indicates a stop.

The display indicates whether the display device is ON or OFF. The scanning of the touch panel represents a state in which the touch panel 1 scans a pressed point and detects coordinate data (X axis / Y axis). ON indicates detection, and OFF indicates stop.

From left to right of the system mode: In the case of the first operation mode from the left, the CPU is turned on, the display is turned on, the touch panel scan is turned on, and the pressed point of the touch panel 1 is detected. The coordinate data (X axis / Y axis) is transferred to the CPU 5.

In the case of the second pseudo operation mode from the left, a process for stopping the CPU 5 is performed in S21, and the CPU 5 is stopped (OFF) (display is ON).
Remains).

In the case of the third operation mode from the left, since the touch panel 1 is depressed in S22, the processing for starting the CPU in S23 by interruption is performed, and then the CPU 5 is operated (ON). To At this time, during the processing time of S23 from the time when the touch panel 1 is pressed to the time when the CPU 5 is operated, the coordinate data of the pressed point on the touch panel 1 is changed to the amount of change (X axis / Y axis) and stored in the buffer memory 4. The amount of change (X-axis / Y) taken out of the buffer memory 4 when the CPU 5 enters the operating state
Axis) is reproduced as coordinate data (X axis / Y axis) and transferred to the CPU 5.

In the fourth suspend mode from the left, the CPU 5, display, and scanning of the touch panel are all stopped. FIG. 6 is an explanatory diagram of the AD conversion of the touch panel of the present invention.

FIG. 6A shows the AD conversion of the X axis. When performing the X-axis AD conversion, the touch panel 1
Is obtained by superimposing an X sheet in which a voltage is applied to both ends of a plurality of resistance lines in the X direction and a Y sheet having both ends opened in a plurality of orthogonal resistance lines in the Y direction, and pressing the intersection thereof to make contact. A voltage corresponding to the pressed point in the X-axis direction can be detected at a point where both ends of the Y sheet are opened, and the X-axis voltage is AD-converted to obtain X coordinate data.

FIG. 6B shows the AD conversion of the Y axis. In the case of performing the Y-axis A / D conversion, similarly, the touch panel 1 opens both ends of the plurality of resistance lines in the X direction orthogonal to the Y sheet in which voltage is applied to both ends of the plurality of resistance lines in the Y direction. By pressing the intersection of the X sheet and the intersection thereof, the voltage corresponding to the pressed point in the Y-axis direction can be detected at the point where both ends of the X sheet are opened. Convert to obtain Y coordinate data.

[0040]

As described above, according to the present invention,
Difference data is created for the coordinate data of the X coordinate and the Y coordinate detected from the touch panel 1, saved in the buffer memory 4, and the original X coordinate value and the Y coordinate are reproduced based on the difference data extracted from the buffer memory 4. And a large amount of coordinate data is saved in the same buffer memory 4, and the coordinate data is missed during coordinate detection and character recognition on the touch panel 1. And can be operated normally.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating the operation of the present invention.

FIG. 3 is a format example of coordinate data of a touch panel according to the present invention.

FIG. 4 is a mode example of the system of the present invention.

FIG. 5 is an example of a time chart of the present invention.

FIG. 6 is an explanatory diagram of AD conversion of the touch panel of the present invention.

FIG. 7 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1: Touch panel 2: A / D converter 3: Touch panel controller 4: Buffer memory 5: CPU

Claims (7)

[Claims] 1. A data transfer device for detecting and transferring an X coordinate and a Y coordinate of a pressed point of a touch panel, wherein a value corresponding to the X coordinate and the Y coordinate of the pressed point detected from the touch panel is A-valued. AD to D conversion
A converter; means for obtaining X difference data and Y difference data based on the X coordinate value and Y coordinate value converted by the A / D converter; and temporarily determining the obtained X difference data and Y difference data. A buffer memory for storing the data, means for reproducing the original X coordinate value and the original Y coordinate value based on the X difference data and the Y difference data taken out of the buffer memory, respectively, and X converted by the AD converter. Coordinate value and Y
Means for transferring the coordinate values or the reproduced X coordinate values and Y coordinate values to a transfer request source. 2. The X difference data and the Y difference data are a difference between a previous X coordinate value and a current X coordinate value and a difference between a previous Y coordinate value and a current Y coordinate value. The data transfer device for a touch panel according to claim 1. 3. The method according to claim 1, wherein the difference between the previous X coordinate value and the current X coordinate value is within a predetermined value or the difference between the previous Y coordinate value and the current Y coordinate value is determined as the X difference data and the Y difference data. 3. The touch panel data transfer device according to claim 1, wherein the X difference data and the Y difference data are output when the difference is within a predetermined value. 4. Two bytes are used for the X coordinate value and the Y coordinate value, and one byte is used for the X difference data and the Y difference data.
4. The data transfer device for a touch panel according to claim 1, wherein a byte is used. 5. Only when the transfer request source cannot receive the X coordinate value and the Y coordinate value, the X difference data and the X difference data based on the X coordinate value and the Y coordinate value converted by the A / D converter. Y difference data is generated and temporarily stored in the buffer memory, and when the transfer request source is ready to receive, the original X coordinate value based on the X difference data and the Y difference data from the buffer memory. 5. The data transfer device for a touch panel according to claim 1, further comprising means for reproducing and transferring the Y coordinate value. 6. An X-difference data and a Y-difference data are generated based on the X-coordinate value and the Y-coordinate value converted by the A / D converter and stored in the buffer memory. 6. The touch panel data transfer device according to claim 1, wherein the original X coordinate value and Y coordinate value are reproduced and transferred based on the data and the Y difference data. 7. A voltage at a point where the touch panel is depressed by superposing an X sheet provided with a plurality of resistance lines in the X coordinate direction and a Y sheet provided with a plurality of resistance lines in the Y coordinate direction is detected. 7. The data transfer device for a touch panel according to claim 1, wherein the detected voltage is converted into an X coordinate value and a Y coordinate value by the AD converter and output.