JPH01273122A - Coordinate input device - Google Patents

Abstract

PURPOSE:To raise the coordinate input accuracy, and also, to improve the reliability by detecting a conducting state of an electrode provided on a resistor sheet at the time of initializing, and inhibiting a coordinate input and giving a warning, if a normal conducting state cannot be detected. CONSTITUTION:At the time of initializing a device, a conducting state of electrodes provided on resistor sheets 2, 3 is detected, and if a normal conducting state cannot be detected, a prescribed error processing is executed, a coordinate input is inhibited and a warning is given. Accordingly, such states as deterioration of input accuracy, input impossibility, etc. caused by disconnection of the resistor sheets 2, 3, a contact failure, a foreign matter loaded onto the input surface, etc. are prevented, and also, by repeating the check of an input value, only a normal input value can be inputted. In such a way, the detection accuracy can be improved.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a coordinate input device, in particular, a coordinate input device, in which a plurality of resistor sheets are arranged facing each other by a predetermined distance, and pressed down from one side to bring the opposed resistor sheets into contact with each other. The present invention relates to a coordinate input device that inputs the coordinate value of a pressed point based on a change in resistance value detected through a resistor sheet.

[Prior Art] Conventionally, as a coordinate input device, resistor sheets coated with a resistor are arranged facing each other at a predetermined distance apart, and by pressing them from one side, coordinates are determined by changing the resistance value obtained through the resistor sheet. Pressure-sensitive devices for detecting are known. Such coordinate input devices are used for inputting handwritten characters, images, etc. into a personal computer or the like, or as an editor for specifying a copy range in a copying machine or the like.

[Problem H to be solved by the invention] - The pressure-sensitive coordinate input device using a resistive film as described above has the following problems regarding its coordinate input accuracy and reliability.

1) In the resistor sheet of the device, a large number of parallel electrodes are provided on the resistor base film by silver printing or the like, and changes in resistance are detected through these electrodes.

The multiple electrodes are connected to a detection circuit using flexible cables or the like. In this structure, where a large number of electrodes are connected via connectors using flexible cables, electrode disconnection or poor contact is likely to occur, which can lead to problems such as inaccurate coordinate input or the inability to input coordinates. was there.

2) When resistor sheets are placed facing each other and are brought into contact at the coordinate input point, and the input coordinates are detected through both resistor sheets, the resistor sheets must be in contact at only one of the input points. is assumed. If the resistor sheets are in contact at two or more points, the information output through the resistor sheets will of course change significantly and the input coordinates will be incorrect. For this reason, if the operator turns on the power and attempts to perform Fg scale input with a heavy object placed on the input surface, there is a possibility that the output coordinates will be incorrect and the operator will not notice even I;).

3) In the method of placing resistor sheets facing each other and making them contact each other at the coordinate input point, contact resistance exists between the resistor sheets, so depending on the setting of the voltage detection threshold,
Even if the input surface is pressed with a slight force, coordinates may be input.

For this reason, a configuration has been considered in which a switch is provided to detect the pressing force of the input pen so that input is performed using a predetermined input pen, and coordinate input is performed only when a pressing force of a predetermined value or more is applied. However, in such a configuration, it is necessary to take in the switch output of the input pen via a cable or the like, and there is a problem in that the operability of the input pen is significantly hindered. However, if such a configuration is not provided, the detection accuracy will deteriorate due to the contact resistance between the resistor sheets.

The object of the present invention is to solve the above problems.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, a plurality of resistor sheets are arranged facing each other at a predetermined ratio, and the opposing resistor sheets are pressed down from one side to bring them into contact with each other. In a coordinate input device that inputs the coordinate value of a pressed point based on a resistance value change detected through a resistor sheet, detecting a conduction state of an electrode provided on the resistor sheet at the time of initializing the device, If a normal conduction state cannot be detected, predetermined error processing is performed and coordinate input is prohibited, or the contact state of the resistor sheet is detected at the time of initializing the device, and even if coordinate input is not performed, If contact with the resistor sheet is detected, predetermined error processing is performed and coordinate input is prohibited, or coordinate input is repeated multiple times and the input value is within a predetermined range that includes the reference value input at the beginning of each repetition. We adopted a configuration in which when coordinate values are obtained multiple times, the final input coordinate value is taken in as the valid input value.

[Function] According to the above configuration, disconnection of the resistor sheet, poor contact,
It is possible to prevent situations such as input failure due to input disturbances caused by foreign objects placed on the input surface, etc., and to repeatedly check input values to capture only normal input values.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings. The configuration of a coordinate input device in an editor for specifying a copying range of a copying machine will be described below.

FIG. 1 shows an editor for a copying machine employing the present invention. As shown in the figure, the main body of the apparatus is a flat plate, and is configured as a document holder for a copying machine. Almost the entire center of the device is an input surface 7, and an operation section 8 is provided on the front side of this input surface 7.

The operation unit 8 performs various operations, such as extracting a specified image range,
Alternatively, an input key 81 is provided for specifying processing such as copying only that part. Among the input keys 81, those that need to display the operation mode have LED 8.
2 is attached as an indicator.

Further, on the other side of the input surface 7, a recess 9 for placing the input ben 6 is provided. A switch (not shown) is provided at the bottom of the recess 9 to detect whether the input ben is placed in that position. If this switch is not operated, it is determined that the operator has started inputting.

FIG. 2 shows the structure of the coordinate input section provided at the bottom of the input surface 7. In FIG. 2, reference numeral 1 is a protection sheet for protecting the input mechanism, and as shown in the figure, ruled lines are printed to designate the range of the document. Each member indicated by reference numerals 2 to 5 is laminated under the protective sheet 1. As shown in FIG. An X-resistance sheet 2 is provided under the protection sheet 1.

Further, an X-resistance sheet 3 is provided at the lower part of the X-ray resistor sheet 3 with a dot spacer 4 interposed therebetween. As shown in the cross section on the right side of FIG. 2, the X-resistance sheet 2 and the X-resistance sheet 3 are placed facing each other by a dot spacer 4 with a predetermined distance ms between them.

A resistor is uniformly coated on the opposing surfaces of both resistive sheets, and electrodes 2X and 2y for extracting a detection signal are provided in parallel. Electrodes 2x, 2 of each resistor sheet 2.3
Although y is provided parallel to the x and y coordinates shown at the bottom of the figure, the electrode 2x is arranged parallel to the y-axis, and the electrode 2y is arranged parallel to the X-axis. The arrangement pitch of the electrodes 2x, 2y is set according to the desired input resolution. A metal plate 5 is placed below the X-resistance sheet 3 to ensure rigidity.

Next, the coordinate detection principle of the coordinate input section in Fig. 2 is explained in Fig. 3 (A
), as shown in FIG. 4, in FIG. 3(A), the symbols 2 and 3 are the X resistor sheet 2 and the X resistor sheet 3 in FIG. 1, respectively.
1, and the reference numeral 10 indicates the electrodes 2x and 2y in FIG.

The electrodes 2x, 2y are connected to pickup bins x1-xlO1 and y1-y10, which are detection electrodes, respectively. Pick up bin x1, x10 and yl, ylo
A power supply voltage VD can be applied to both ends of the transistors through transistors TXH%TXL and TYH%TYL, respectively. When the input surface 7 is pressed down through the protective sheet 1 by the input ben 6 in FIG. 1, the contact resistance RC of the X-resistance sheet 2 and the
connected via. Here, detection of the X coordinate will be described.

When detecting the X coordinate, transistors TYH and TYL
is cut off by the control signal YH%YL, and the transistor T
XH%TXL is made conductive by control signal XH%XL. At this time, voltages corresponding to the distances of the respective electrodes are generated in the pickup bins x1 to xlO. On the other hand, a voltage measuring section such as an AD converter is connected to the pickup bins y1 to y10. If we consider that the input impedance of this voltage measuring section is infinite, then the pickup bin y
The voltages from 1 to y10 are all equal and equal to Vx. This voltage can be considered as the partial pressure at the pressure point located between any two of the electrodes 2x connected to the pickup bins X1 to xlO.

On the other hand, by measuring the respective voltages of the pickup bins x1 to xlO in advance and storing them in a memory or the like, the voltages of each of these and the pickup bins y1 to y
By comparing the voltages Vx obtained from any of the pickup bins 10 to 10, it is possible to identify which two of the pickup bins x1 to xlO the input point is located between. Figure 4 shows this situation.

FIG. 4 shows the relationship between the distance between the detection point on the X or y axis and the origin and the detected voltage, with the horizontal axis representing the distance 11L and the vertical axis representing the voltage V. vO to V9 on the vertical axis are voltages of pickup bins x1 to xlO. Also, 1121.3 on the horizontal axis
1... indicates the distance between the electrodes 2x.

Here, if an input is made between pickup bins x8 and x9, the voltage Vx that can be detected from any of pickup bins y1 to yto will naturally be between pickup bins x8 and x9.
The value is between voltage v7 and v8 which is the voltage of x9. Therefore, the X coordinate value is the sum of the distance to the electrode of pickup bin x8 plus the distance obtained by dividing the distance between pickup bins x8 and x9 by the ratio of the difference between voltages v7 and Vx, and Vx and v8. If this is converted into a film, the X coordinate becomes vx -vN. Here, Vn is the maximum Vn that satisfies V n < V x. Although the X coordinate can be determined as described above, the X coordinate can also be determined by performing similar detection with the transistor settings reversed.

Note that, of course, the number of electrodes on the resistor sheet and the number of pick-up pins are not limited to the above.

FIG. 5 shows the structure of the control system of the apparatus shown in FIG.

In the figure, numerals 51 to 54 each represent an 8-channel multiplexer, and multiplexers 51, 52 and 53
．． Reference numerals 54 are for connecting the X resistor and the pickup bins of the X resistor shown in FIG. 3(A) to the A/D converter 55, respectively. In addition, the reference numeral 57 is shown in FIG. 3 (A
) is an amplifier that amplifies control signals that control transistors TXH, TxL%TYH%TYL, respectively.

The CPU 56 is composed of a microprocessor, etc., and performs the settings explained in connection with FIGS. 3(A) and 4 via the multiplexers 51 to 54 and the gate 57, and controls the voltage of each pickup bin and the detected voltage. Vx to vy are detected via the A/D converter 55. A/
Based on the detected voltage of the digital value taken out via the D converter 55, the CPU 56 detects the input coordinate value by calculating the equations (1) and (2).

Further, one end of the input key 81 in FIG. 1 is each pulled up to the power supply voltage via a resistor, and this terminal voltage is inputted to the CPU 56 as a switch detection voltage. In response to each switch operation, the CPU 56 turns on the LED through the gate 64.
82 (see Figure 1). Further, a switch 58 for detecting whether or not the input pen is removed from the recess 9 in FIG. 1 in the control described later is also connected to the CPU 56. The input circuit of this switch 58 is similar to that of the input key 81. Furthermore, a buzzer 59 for error notification is connected to the CPO 56.

The arithmetic processing of the CPU 56 uses the RAM 62 as a work area, and this RAM 62 is used as a buffer for the detection voltage of the pickup bin, a buffer for input coordinate values, or a setting area for various control flags. A program for the CPU 56, which will be described later, is stored in the ROM 83.

The CPU 56 transmits the X and X coordinates detected as described above to the main body of the copying machine via serial communication. Also, various commands are similarly received from the copying machine main body through serial communication.

Reference numeral 65 in FIG. 5 is a gate that buffers signals sent and received to and from the main body of the copying machine. As can be seen from the direction of the gate, the signals ACK and TXD are transmission signals to the copying machine main body, and the signals REQ and RXD are reception signals from the copying machine main body. Serial transmission is controlled as shown in FIG.

The main body of the copying machine periodically activates the signal REQ to the editor (low level). The editor activates the signal ACK (low level) immediately after the signal REQ is activated. After confirming activation of ACK, the copying machine body serially transmits 8 bytes of data to the editor. Further, the editor also serially transmits 8 bytes of data to the main body of the copying machine after the signal ACK becomes active. After receiving the data from the editor, the copying machine main body deactivates the signal REQ (high level).

The editor also outputs signal A in response to this deactivation of signal REQ.
CK is deactivated (high level).

FIGS. 7 and 8 show transmission data and reception data transmitted and received by signals TXD and RXD, respectively. As shown in the figure, both data are in a packet configuration, and bytes BO to B7 to be transmitted and received are composed of 8 bits b7 to bo, and information as shown in the figure is assigned to each bit.

In the editor transmission data shown in FIG. 7, bits b1 and bo of byte BO are control flags, EDON, E
It is DPICK. The flag EDON is a flag that determines whether or not the coordinate input state is based on the detection state of the switch 58 in FIG. 5, which is controlled by the placement of the input ben 6 in the recess 9.

The flag EDPICK is a flag indicating whether fixed coordinate data has been input. Each bit of the next byte Bl indicates the operating state of each key of the operating section 8. Bytes B2 and B3 express the distance using each nib (half byte) as a BCD code.
Each expresses the X coordinate by a straight line distance. Part-time job B
4 and B5 similarly express the X coordinate.

On the other hand, in FIG. 8, bit bO of byte BO is a flag PKCATCH, which indicates that the main body side has received data normally. Bytes B1 are lighting control information for controlling the LEDs 82 of the operation unit 8, respectively.

Next, the operation in the above configuration will be explained. Here, some examples of control procedures performed by the CPU 56 will be shown.

The control procedure is shown in the flowcharts from FIG. 9 onwards, and the illustrated procedure is stored in the ROM 63 as a program for the CPU 56.

Note that in the flowcharts below, it is assumed that the flow is continuous at points with the same number.

The procedure shown in FIG. 9 solves the problem 1) mentioned in the section on problems of the present invention. That is, although the electrodes 2x and 2y of the X resistor sheet 2.3 in FIG. 2 are connected via a flexible cable or the like, it is conceivable that a normal detection signal cannot be output due to disconnection, poor contact, or the like. Therefore, the procedure shown in FIG. 9 is intended to prevent such disconnections, failure of input due to poor contact, or deterioration of input accuracy.

When the device is powered on, the CPU 56 determines whether or not there is a disconnection of the electrode in step S91 of FIG. This determination is made as follows.

Here, first, the transistor TXH% of FIG. 3(A)
TXL is turned on, TYH%TYL is turned off, and the pickup bin
Measure the voltage of ~xlO. If there is a disconnection or poor contact, the voltages of the pickup bins x1 to xlO will no longer show normal values, so it is only necessary to determine whether the voltage of each pickup bin is within a preset range. Similarly, turn on transistor TYH%TYL,
Turn off TXH%TXL, pick up bins y1 to y
Disconnection or poor contact is detected by measuring the voltage on the 10 side.

If an abnormality is detected in step S91, step S91 is detected.
In step S92, a predetermined number or all of the LEDs 82 of the operation section are made to blink, and in step S93, the buzzer 59 is made to sound.

Subsequently, in step S94, the main body of the copying machine is notified that an error due to disconnection or poor contact has occurred in the format shown in FIG. In this case, in the editor transmission data shown in Figure 7, byte B6, bit b2 (ER
Transmission is performed with R2) set to 1.

If no abnormality is found in step S91, the process moves to step S95. In step S95, the state of the switch 58 shown in FIG.
Determine whether it is placed in When the input ben 6 is placed in the recess 9, the switch 58 is turned on, and the process advances to step 396 for eight lines.

When the input ben 6 is picked up, the switch 58 is turned off and the process moves to step S97. In step S96, the flag EDON, which controls the capture of input coordinate data, is reset to prohibit coordinate input, and the process returns to step S95. When the operator picks up the input ben 6, the switch 58 is turned off, and in step S97, the flag EDON is set to enable coordinate input.

Subsequently, in step 39B, it is determined whether coordinates have been input. This judgment is performed as before by inputting
This is performed by comparing the output of a pressure-sensitive switch provided at the tip of the sensor or the detection voltage Vx to vy detected from the pickup bottle, which changes depending on the contact resistance, with a reference value.

Once the coordinates have been input, the process moves to step S99, and the above-mentioned (
Coordinate calculations are performed using equations 1) and (2).

In step 5100, the detected coordinate values are transmitted to the copying machine main body in the format shown in FIG.

In step 5101, a flag EDP is used to confirm coordinate input.
ICK is set, and in step 5102, the flag PK is sent from the copying machine in the format shown in Figure 8.
Determine whether CATCH is enabled. When the copying machine receives the input coordinate values normally, it activates this flag and returns it, so if step 5102 is affirmed, the process moves to step 5103 and flag EDPICK is activated.
Reset.

The states of these flags are sequentially transmitted to the main body of the copying machine. In step 5104, the process waits until the flag PKCATCH becomes inactive to request the next data transmission, and if step 5104 is affirmed, the process returns to step S95.

According to the above configuration, before starting coordinate input, it is always determined whether there is any disconnection or poor contact of the electrodes, and if such an abnormality is found, the buzzer and LED are activated.
Displays an error message and prohibits coordinate input. Therefore, the operator can easily identify that there is an abnormality in the coordinate input section, and can take appropriate measures such as arranging repairs. In addition, in the case of an error display, which electrode is abnormal may be indicated by the type of LED that is blinked. This allows inspection and repair work to be carried out easily.

The procedure in FIG. 10 is used in place of steps 391 to S94 in FIG. 9, but may be inserted immediately before step 591 or between steps S91 and 595.

Problem 2) mentioned in the section on problems of the present invention is that if a heavy object is placed on the input surface 7 when the power is turned on, and input is performed without noticing this, more than 2 points on the input surface 702 will be pressed and the coordinates Although it is affected by the input, the procedure shown in Figure 10 determines whether or not the X-resistance sheet 2.3 is in contact with the input surface due to pressure at the start of control, and if so, performs error processing. It is something to do.

In step 391' of FIG.
Determine whether they are in contact with each other. This determination can be made via a circuit as shown in FIG. 3(B). In FIG. 3(B), reference numeral 71 indicates a comparator, and the output of this comparator 71 is sent to the CPU 56.
is input. The manual input terminal of the comparator 71 has a reference voltage VREF obtained by dividing the power supply voltage VD by resistors R1 and R2.
is entered.

Further, the - input terminal is connected to one of the pickup terminals on the y resistor sheet 3 side (here, yl). - A load resistor R is connected between the input terminal and ground.

In step 391', transistor TX)1%TXL is turned on, TY)l.

Turn off TYL. As a result, the resistor sheet 2.
3 is not in contact, the voltage V is not input to one input terminal of the comparator 71, but if it is in contact, the voltage vrN of the one input terminal becomes . emitter voltage). This input value VIN is VR on the input terminal side.
When it becomes larger than EF, a low level contact detection signal is input to the CPU 56.

If the resistor sheet is in contact in the initial state such as when the power is turned on, it is considered that something heavy is on the input surface 7. Therefore, the process moves to step 392' and performs the same operation as step S92 above. A predetermined LED of the section 8 is made to blink, and the buzzer 59 is made to sound in step 393'.

In step 594', the main body of the copying machine is notified that an error has occurred in the format shown in FIG. In this case, in the editor transmission data of FIG. 7, the ratio of byte B6 ≠ 44,000 bits b.

Transmission is performed with (ERRO) set to 1. This notifies the user that the resistor sheet is in contact with the main body.

By performing such processing at the time of initialization, the resistor 2.3 will not come into contact with the pressure of a foreign object and the coordinate input will not be possible, and only the press information of the input ben 6 can be taken in from the input surface. can.

Furthermore, FIG. 11 shows a different control procedure. The procedure shown in FIG. 11 solves problem 3) mentioned in the section on problems of the present invention. According to the procedure shown in FIG. 11, the input ben 6 operation by the operator can be reliably reflected in the input coordinates without providing a switch for detecting pressing force on the input ben 6.

In the procedure shown in FIG. 11, the coordinate input value is checked n times, and if the input value is within a normal range, that value is treated as a valid input value. On the other hand, if the value is not within the normal range, the input is repeated again, but if the input value does not fall within the normal range and loops eight times, error handling is performed.

Steps S95 to S97 in FIG. Now, in the case of FIG. 9, exactly the same processing as in step E is performed.

That is, the flag EDON is controlled by detecting whether or not the input ben 6 is placed in the recess 9. When the operator picks up the input ben 6, the flag EDON is set and the process moves to step 5150.

In step 5150, the circuit of FIG.
Contact between the resistor sheet 2 and the X resistor sheet 3 is detected.

If step 5150 is affirmed, step 515
If the answer is negative, the process moves to step 5151.

In steps 5151 and 5152, the check counter and loop counter are reset to zero. The check counter counts the number of normal inputs in the previous n times, and the loop counter counts the number of abnormal inputs in the previous N times. When step 5152 ends, the process returns to step S95.

When the input is detected, in step 5153, the input coordinate value is detected based on the voltage detection of the X-resistance sheet 2 and the X-resistance sheet 3, as described above.

The coordinate values obtained in step 5153 are
4, the reference values are stored in buffers REFx and REFy, respectively.

Next, a loop consisting of steps 8156 to 5163 for counting the number of normal and abnormal inputs is entered.

First, in step 5156, the loop counter is incremented by one.

In step 5157, the calculation buffers BUFX and BU
A new input coordinate value (same as the first detected value when entering the loop for the first time) is input to Fy.

Next, in step 3158, the buffers BUFX, BUF
It is determined whether the new input value in y is within the range of ±α from the reference values stored in buffers REFx and REFy. If step 5158 is negative, proceed to step 5162; if affirmed, proceed to step 5.
159.

In step 5159, it is determined whether the value of the check counter has reached n. If step S159 is affirmed, the process moves to step 5164, and if negative, the process moves to step 5160.

In step 5160, the check counter is incremented by 1,
In step 3161, the detected values are taken in again from the X resistor sheet 2 and the X resistor sheet 3, coordinate values are determined, and the process returns to step 5156.

On the other hand, if step 3158 is negative, the check counter is reset in step 5162, and then it is determined in step 8163 whether the value of the loop counter has reached N.

If step 5163 is negative, step 51
The process returns to step 53.5154 to re-enter the reference value, and if the answer is affirmative, the process proceeds to step 5170 and subsequent error processing.

When the input value falls within the range of the reference value ±α after repeating n times, the process moves to step 5164, and finally the buffer BUFx
, the coordinate values taken into BUFy are stored in a transmission data buffer or the like in order to be transmitted.

Thereafter, the input coordinate values are transmitted to the main body of the copying machine through transmission processing in steps 8101 to 5104.

This transmission procedure is exactly the same as steps 3101 to 5104 in FIG.

On the other hand, if the input value varies from the reference value even once, the loop is repeated from the reference value input, and the number of trials from the reference value input is N.
If this continues, the process moves to error processing from step 5170 onwards.

The processing in steps 8170 to 5172 corresponds to steps 592 to 394 in FIG. 9, and the error information transmission in step 5172 is performed, which reduces the LED light on the operation unit 8, sounds the buzzer 59, and notifies the copying machine of the error. Now, the seventh
Bit b3 of byte B6 of the transmission data format in the figure
(ERR3) is set to 1 to notify an error.

In the procedure shown in FIG. 11, after an error is determined, input is not completely prohibited, but after an error is displayed for a time corresponding to the timer time in step 5173, re-input is enabled. When it is confirmed in step 5173 that the predetermined time has elapsed, the process moves to step 5174 to stop blinking the LED, stop the buzzer 59 in step 5175, and send information denying the error to the copying machine in step 3176. Then, the process returns to step S95. In step 8176, bit b3 (ERR3) of byte B6 of the transmission data format in FIG. 7 is set to 0 to perform transmission.

According to the above control, if the coordinate values input repeatedly n times fall within the range of coordinate values ±α initially taken in as reference values, the input values are regarded as valid values and the final input values are copied. Can be sent to the machine itself.

In addition, if the input coordinate value falls outside the range of the reference value ±α even once, it will be repeated from the first reference value input, and when the number of times reaches N, an error will be displayed. Therefore, the accurate coordinate value checked multiple times will be displayed. can be entered. In addition, the possible causes of an abnormal input being determined include insufficient pressing force on the input ben 6 or too fast operation speed, but by displaying an appropriate error message, it is possible to prompt appropriate operation. can.

Although three control procedures have been illustrated above, it goes without saying that any combination of these may be used.

Further, in the above embodiment, an editor used for specifying a range in a copying machine is used as an example, but the present invention can of course be applied to any pressure-sensitive coordinate input device.

[Effects of the Invention] As is clear from the above, according to the present invention, a plurality of resistor sheets are arranged facing each other with a predetermined pressure, and the resistor sheets are pressed down from one side to bring the opposed resistor sheets into contact with each other. In a coordinate input device that inputs the coordinate value of a pressed point based on a change in resistance value detected through If it cannot be detected, predetermined error processing is performed and coordinate input is prohibited, or the contact state of the resistor sheet is detected during initialization of the device, and the contact state of the resistor sheet is detected even though coordinates are not input. If contact is detected, predetermined error processing is performed and coordinate input is prohibited, or coordinate input is repeated multiple times, and coordinate values are returned multiple times within a predetermined range that includes the reference value input at the beginning of each repetition. Since we have adopted a configuration in which the final input coordinate value is taken as a valid input value when the
In addition to preventing situations such as reduced input accuracy or failure to input due to disconnection of the resistor sheet, poor contact, or foreign objects placed on the input surface, this function repeatedly checks input values and captures only normal input values. There is no need to provide a pressure-sensitive switch or the like on the input member, which has the excellent effect of increasing the coordinate input accuracy of the device and improving reliability.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the structure of a coordinate input device employing the present invention, Fig. 2 is an explanatory diagram showing the structure of the input section of the device of Fig. 1, and Fig. 3 (A) is an illustration of the input section. A circuit diagram showing the basic structure, FIG. 3(B) is a circuit diagram showing different configurations of the input section, and FIG. 4 is a diagram showing the operation of the circuit in FIG. 3(A).
Fig. 5 is a block diagram showing the structure of the control system of the coordinate input device, Fig. 6 is a timing chart showing the communication state of the coordinate input device, and Fig. 7 shows the transmission data format of the coordinate input device. Explanatory diagram, Figure 8 is an explanatory diagram showing the received data format of the coordinate input device, Figures 9 to 11
The figures are flowcharts showing different coordinate input control procedures. 1... Protective sheet 2... X resistor sheet 3... Y resistor sheet 4... Dot spacer 5... Metal plate 6... Input ben 7...
・Input surface 8...Operation unit 9...Recesses 51-54...Multiplexer 55 ・A/D near inverter 56-CPU
57...Gate 62...RAM63
...ROM 71...Comparator 81...Input key 82...-LED Seat connection input rabbit θ feeding feather (2) Fig. 2 Input section input section aAtL 4th Figure 6.

Claims (1)

[Claims] 1) A plurality of resistor sheets are arranged facing each other at a predetermined distance apart,
In a coordinate input device that presses down from one side to bring opposing resistor sheets into contact and inputs coordinate values of a pressed point based on a resistance change detected through the resistor sheet, the resistor sheet is pressed at the time of initializing the device. 1. A coordinate input device that detects a conduction state of an electrode provided in the terminal, and if a normal conduction state cannot be detected, predetermined error processing is performed, and coordinate input is prohibited and a warning is issued. 2) A plurality of resistor sheets are arranged facing each other at a predetermined distance apart,
In a coordinate input device that presses down from one side to bring opposing resistor sheets into contact and inputs coordinate values of a pressed point based on a resistance change detected through the resistor sheet, the resistor sheet is pressed at the time of initializing the device. Detects the contact state of the resistor sheet, and if contact with the resistor sheet is detected even though coordinates have not been input, predetermined error processing is performed, and coordinate input is prohibited and a warning is issued. input device. 3) A plurality of resistor sheets are arranged facing each other at a predetermined distance apart,
In a coordinate input device that presses down from one side to bring opposing resistor sheets into contact and inputs the coordinate value of the pressed point based on the resistance change detected through the resistor sheet, the coordinate input is repeated multiple times. A coordinate input device characterized in that when coordinate values are obtained multiple times within a predetermined range that includes a reference value that is first input, a final input coordinate value is taken as a valid input value. 4) If a coordinate value is obtained outside the predetermined range that includes the reference value, perform the repeat process from the first reference value input, and if the input from this reference value input is repeated a predetermined number of times, a predetermined error occurs. The coordinate input device according to claim 3, characterized in that the coordinate input device shifts to processing.