JPH0580922A - Calibration system for analog touch panel - Google Patents

Abstract

PURPOSE:To eliminate the need for troublesome periodic calibration by dynamically performing calibration when the touch panel is actually used. CONSTITUTION:The frequency of depression of the touch panel P is accumulated and stored and when the accumulated and stored value reaches a decision value during the actual use of the touch panel, the position of the touch panel P is automatically corrected. Further, the frequency of depression of the touch panel P is accumulated and stored in a storage device 7 and when the accumulated frequency reaches a specific value, the position is automatically corrected. Further, a calibration device is provided, the frequency of depression of the analog touch panel P is stored, and when the accumulated frequency reaches the specific value, the position is automatically corrected. Thus, the calibration is dynamically performed during the actual use of the touch panel P to eliminate the need for the troublesome periodic calibration and the touch panel P which is calibrated with high precision can be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calibration method for an analog touch panel, and more particularly to a calibration method for an analog touch panel that automatically calibrates a display device used in an information processing device.

[0002]

2. Description of the Related Art For example, in a personal computer or the like, an analog touch panel may be used for data input. The calibration (position correction of data display) of this analog type touch panel is performed by the manufacturer at the time of initial shipment, or by the user as necessary or periodically. The analog touch panel has advantages over the digital touch panel in that the inputable area is arbitrary, the layout of menu selection can be freely set, and handwriting input is possible.

[0003]

However, although the analog type touch panel (hereinafter referred to as a touch panel) has the above-mentioned advantages, it is necessary to adjust variations in the resistance value of the resistance of the touch panel and increase / decrease in the resistance value due to aging. , Must be calibrated at initial shipment or at regular intervals. Here, as a calibration method, a plurality of designated points (for example,
The designated position is displayed on the LCD arranged below the touch panel) is pressed with a human finger, pen, special jig or the like to correct the linearity of the touch panel. Such a calibration method is complicated, has an extra load on the user, and is a troublesome operation.

Therefore, an object of the present invention is to provide a calibration method in an analog type touch panel which can perform the complicated calibration operation without burdening the user.

[0005]

According to a first aspect of the present invention, in an analog type touch panel which detects the position information of the pressed position of a finger or a pen, the number of times the touch panel is pressed is cumulatively stored. Based on the stored value or elapsed time, the position of the touch panel is automatically corrected during actual use. According to the second aspect of the present invention, a storage device is provided for cumulatively storing the number of times the touch panel is pressed, and the position of the touch panel is automatically corrected when the number of times of cumulative storage reaches a predetermined value. did. Further, in the invention described in claim 3, the input device is configured by including the calibration device according to claim 2.

[0006]

In the calibration method for the analog touch panel according to claim 1, the number of times the touch panel is pressed is cumulatively stored, and when the cumulative stored value reaches a predetermined value while the touch panel is actually used. Automatically corrects the touch panel position. In addition, claim 2
The calibration device for an analog touch panel described above cumulatively stores the number of times the touch panel is pressed, and automatically performs position correction when the cumulative number reaches a predetermined value. Further, in the input device according to claim 3, the number of presses from the analog touch panel is cumulatively stored, and when the cumulative number reaches a predetermined value,
Position is automatically corrected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a calibration method for an analog touch panel according to the present invention will be described below with reference to FIGS.
This will be described in detail with reference to 2. First, prior to the description of the embodiments of the present invention, a structure of an analog type transparent touch panel used in the present embodiment, a detection method of a pressed position, and a calibration will be briefly described. 1 and 2 show the structure of the touch panel. As shown in FIGS. 1 and 2, two resistor films 1 and 2 are arranged to face each other with a spacer 3 interposed therebetween, and resistance is provided on the facing surfaces of the resistor films 1 and 2 which are arranged above and below. The bodies 1a and 2a are formed. Electrodes 1b and 1 are provided on both ends of each resistor film 1 and 2.
c and electrodes 2b and 2c are formed. And the code T
The upper and lower resistor films 1 and 2 are brought into contact with each other by pressing the effective contact area with a part (double-hatched part) indicated by (4) with a finger or a pen. The contact position of the resistor when the pen or the like is pressed down depends on the electrodes 1b, 1
It can be obtained from the resistance value from c, 2b, 2c to the contact position, and this resistance value is converted into a voltage, and the A / D
It is converted into a digital value by the converter and the coordinates are calculated.

FIG. 3 shows an equivalent circuit when the effective contact area T is pressed. The coordinates of the depression point Q in the effective contact area T are expressed by RX and RY when expressed by resistance values.
As shown in FIG. 4, a touch panel P is placed on the LCD, and the size of the LCD dot is 640 dots ×
With 400 dots, when an operation (depression) is performed on a menu or the like on the LCD, 640 × 400 dots become the effective area (LCD display unit) 4 of the actual touch panel.

Next, the operation of the embodiment thus constructed will be described. Here, the operation of calibration will be described. The two-point correction shown in FIG. 5 will be described for the sake of simplicity. The two-point correction associates respective X-direction resistance and Y-direction resistance obtained by pressing two points A and B on the effective area 4 of the touch panel with coordinates. In Figure 4, the coordinates of point A are (0,0)
And the coordinates of point B are (639,399). The resistance values corresponding to the points A and B are (RXa, RYa), (R
Xb, RYb). By using the obtained resistance value, the offset coordinates are obtained by linear approximation. FIG. 5 shows the above relationship as a diagram. The “solid line” is the actual measurement value of the resistance value change between two points A and B, and the “dotted line” is the actual measurement value a for point A and the actual measurement for point B. It represents a linear approximation in which the value b is connected by a straight line. The above relationship is shown in Table 1 below.

[0010]

[Table 1]

Generally, the data obtained by the calibration is written in a non-volatile memory and referred to when the coordinates are calculated. That is, when the correction value is determined according to the contents of Table 1, 640 × 400 of the LCD display unit 4 shown in FIG.
The coordinates (X, Y) when the resistance value obtained by pressing a certain place in the dot is R1 in the x direction and R2 in the y direction are calculated by the following equation. X = 639 × (R 1 -RXa) / (RXb-RXa) Y = 399 × (R 2 -RYa) / (RYb-RYa)

Further, in consideration of changes in resistance value due to environmental resistance of the touch panel, aging, etc., it is necessary to calibrate periodically. That is, as shown in FIG. 6, the correction value of the approximate straight line C may be corrected to the correction value of the approximate straight line D with respect to the change in the resistance value of the resistor due to the environment resistance / aging. The operation according to the gist of the present invention will be described based on the above prerequisites. In the present invention, the calibration is performed, for example, while the touch panel is being pressed due to normal use of the information processing apparatus.

FIG. 7 shows a block diagram of a control system used in this embodiment, FIG. 8 shows data in NVRAM, and FIG. 9 shows the position of the selection menu on the LCD display device 4.
As shown in FIG. 7, the CPU 5 includes a touch panel P via an A / D converter 6, an NVRAM (nonvolatile memory) 7 backed up by a backup power supply 8, and a ROM 9.
And the RAM 10 are connected. NVRAM 7
The data inside is shown in FIG.

Next, the operation will be described. As shown in FIG.
The pressing positions for calibration are set in the selection menu E and the selection menu F. For example, the meaning of the selection menu E is start or on, and the selection menu F is stop or off. Naturally the selection menu E
And the center coordinates of the selection menu F are fixed,
The data obtained by pressing each selection menu can be used as calibration. That is,
Pressing the selection menu means normal function selection (on / off
Off) and the meaning of calibration. As shown in FIG. 10, the selection menu E,
The data obtained by pressing F is cumulatively stored in the NVRAM 7 as a histogram (see FIGS. 11 and 12) (step S1). Then, after a lapse of a certain number of times and a certain time, the average value or the maximum value thereof is obtained as a calibration value (step S2), and the calibration value is automatically updated (step S3).

[0015]

As described above, according to the present invention, since the calibration is performed dynamically when the touch panel is actually used, the user does not need to perform a troublesome periodic calibration, and the calibration can be performed with high accuracy. It is possible to use the touch panel which has been turned on.

[Brief description of drawings]

FIG. 1 is a plan view showing the principle of a touch panel used in an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the principle of the touch panel.

FIG. 3 is a diagram showing an equivalent circuit of the touch panel.

FIG. 4 is a front view of the touch panel.

FIG. 5 is a diagram showing a relationship between an actual measurement value of a resistance value at a touch point on a touch panel and a linear approximation.

FIG. 6 is a diagram illustrating the principle of calibration.

FIG. 7 is a block diagram of an embodiment of the present invention.

FIG. 8 is a diagram showing data in the NVRAM shown in the block diagram.

FIG. 9 is a diagram showing a selection menu on the LCD display panel.

FIG. 10 is a flowchart showing the operation of the embodiment.

FIG. 11 is a histogram showing the cumulative number of touches on the touch panel.

FIG. 12 is a histogram showing the cumulative number of touches on the touch panel.

[Explanation of symbols]

 1 Upper Touch Panel 2 Lower Touch Panel 3 Spacer 4 LCD Display 7 NVRAM E Selection Menu F Selection Menu P Touch Panel

Claims (3)

[Claims] 1. An analog touch panel that detects the position information of the touched by pressing with a finger or a pen. The touching frequency of the touch panel is accumulated and stored, and the actual value is calculated based on the accumulated stored value or the elapsed time of use of the device. A calibration method for analog touch panels that automatically corrects the touch panel position when in use. 2. A storage device for accumulatively storing the number of times of touching the touch panel, wherein the position of the touch panel is automatically corrected when the number of times of cumulative storage reaches a predetermined value. Calibration device for analog touch panel. 3. An input device comprising the calibration device according to claim 2.