JPH02155021A - Coordinate input device - Google Patents

Abstract

PURPOSE:To set the pressure of a resistor sheet for an effective input at a desired value by providing a control means which validates input information when the pressure of the resistor sheet is at >= a prescribed value, and a means which variably controls the prescribed value to validate the information. CONSTITUTION:In a coordinate input part provided at the lower part of an input surface, an (x) resistor sheet 2 and a (y) resistor sheet 3 are provided so as to face each other at a prescribed interval. The voltage of the ground side terminal of the (y) resistor 3 is inputted to a comparator 71a, and it is compared with a voltage VREF obtained by dividing a supply voltage VD by means of resistances R1 and R2. The comparator 71a measures a voltage drop corresponding to the contact resistance when the resistor is pushed down, and decides whether or not the effective value is inputted. Thus, by making the resistance R2 variable, the tablet pressure necessary for the effective input can be regulated to the desired value.

Description

Detailed Description of the Invention [Industrial Field of Application] 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 with a predetermined pressure i1 apart, 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, coordinate human-powered devices using various systems have been used. Typically, this type of device has a dedicated input pen, a regular writing instrument, an input tablet operated with a fingertip, etc., and detects the coordinates of the operator's input point using various detection methods. In particular, as one of the detection methods, resistor sheets are placed facing each other to form a tablet, the resistor sheets are brought into contact with each other by pressing force during input, and the coordinates of the human power point are determined based on the resistance value information obtained from the resistor sheet. What it detects is known. Such coordinate input devices are used to input handwritten characters, images, etc. into personal computers, etc.
It is also used as an editor for specifying the copy range in copying machines and the like.

[Problems to be Solved by the Invention] In a coordinate input device using a resistor as described above, in order to determine whether an input is being made, a comparator or the like is used to measure the voltage drop due to the contact resistance of the upper and lower resistors. Techniques for measuring using the same method are known.

However, in the above conventional example, the reference voltage of the comparator that measures the voltage drop is constant, so the contact resistance value at which input is valid is also fixed at a constant level, and the input surface pressing blade also There was a problem in that the manual operation could not be performed without applying force, and even if the operator felt that the manual force surface pressing blade was too large, the setting could not be changed.

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 with a predetermined distance Wi apart, and the opposing resistor sheets are brought into contact by pressing down from one side. In a coordinate human-powered device that inputs the coordinate value of a pressed point based on a change in resistance value detected through a resistor sheet, the input information is validated when the pressing force of the resistor sheet is equal to or greater than a predetermined value. and a means for variably controlling the predetermined value for validation.

[Operation] According to the above configuration, the pressing force of the resistor sheet for effective input can be set as desired by the variable control means.

[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 according to 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, a 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 pen is placed at 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 with a predetermined pressure mu between them by a dot spacer 4.

A resistor is uniformly coated on the opposing surfaces of both resistor sheets, and electrodes 2x and 2y are provided in parallel for extracting a detection signal and for averaging the voltage distribution on the resistor. The electrodes 2x and 2y of each resistor sheet 2.3 are provided parallel to the x5yu keyaki shown at the bottom of the figure, but the electrodes 2.
x is arranged parallel to the y axis, and the electrode 2y is arranged parallel to the X glaze.

The arrangement pitch of the electrodes 8i2x and 2y is set according to the desired manual resolution. These electrodes are connected to pickup bins P1 to PIO, respectively, as shown in the equivalent circuit of FIG. The electrodes taken out by the pickup pins P1 to PIO are used as correction voltages during coordinate calculation as described later. A metal plate 5 is placed below the X-resistance sheet 3 to ensure rigidity.

As shown in Fig. 3, a predetermined power supply voltage VD is applied to the X%y resistor 2.3, and the on/off of the power supply side and ground side is controlled by a transistor TX)I%TX
L, TYI (, TYL) can be independently controlled. Also, the voltage at the ground terminal of the y resistor 3 is input to the comparator 71a, and the power supply voltage VD is connected to the resistor R.
1, and is compared with the voltage V REF divided by R2.

This comparator 71a measures the voltage drop corresponding to the contact resistance when the resistor is pressed, and determines whether or not a valid input is being made.

When one point on the input surface is pressed with an input pen (or other projection), the X-resistor sheets 2 and 3 are connected via the contact resistance Rc, as shown in FIG.

At this time, if the transistor TXI is turned on, the value of the input voltage Vi of the comparator 71a will be Vl = O when the tablet is not pressed down, so Vi<VRE.
F, and the comparator output becomes the VO valve VD.

If the tablet is pressed, Vi = (VD - VCE) / (Ra + Rc + R
b)+R.

At this time, VREF=VD-R+/(R1+R2), so if Vi>VREF, the comparator output becomes Vo40 and is inverted. If this state is monitored by a CPU, which will be described later, valid input from the tablet can be detected.

First, to find the X coordinate, the X resistor side transistor T
Turn on XH, TXL, y resistor side transistor TYH,
When TYL is turned off, the voltage at the X resistor contact appears at the Y resistor pickup electrode.

At this time, if this voltage is VX, the voltages of the pickup electrodes that sandwich the contact part on the x resistor side (bin N+1 and bin N+2) are "N" and VN+1, respectively, and the distance between adjacent pickup electrodes is 1, then As shown in Figure 4, the X coordinate is x-x ・(Vx -v, 4)/(vs++ -VN)
+fL(N-1).

Furthermore, the Y coordinate can also be read using a similar method to determine the coordinates of the pressed point on the tablet.

Here, the relationship between the pressing force on the input surface and the contact resistance of the x and y resistor sheets is shown in FIG. As shown in the figure, if the push-down blade f is large, the contact resistance value Rc of the upper and lower resistors becomes smaller.

Next, the lower part of FIG. 6 shows an equivalent circuit at the time of contact detection. Vi =
The contact resistance RC of the upper and lower resistors when contact is detected from VREF is Ro V CE V CE
RC==R2(1--)-(Ra+Rbi Ro・-
RI VD VD (however, Ra and Rb are the characteristic values of the carbon resistor, R
O1R2 is a constant, and VCE is the voltage across the core-emitter of transistor TXH). Here, when R2 is a variable resistance, it can be seen that if the value of R2 is changed by a large value, the value of the contact resistance value Rc when Vi=VREF becomes large.

As is clear from FIG. 5, this indicates that the value of the pressing blade f for determining a valid input becomes small. Conversely, if the value of R2 is reduced, the value of RC when Vi=VREF becomes smaller, which indicates that the value of the pressing blade f for determining a valid input becomes larger.

Therefore, by making R2 a variable resistor, it becomes possible for the operator to adjust the tablet pressing blade necessary for effective input to a desired value.

FIG. 7 shows a block diagram of the editor control circuit. In the figure, the CPU 71 is a one-chip microprocessor (for example, a μC0M87AD manufactured by Nikkei Co., Ltd.) equipped with a serial communication function.
). , 1m<1) The CPU 71 inputs the voltage of the pickup pin of the x1y resistor as a digital value through the electrode selection 8ch multiplexers 85 to 88 and the A/D converter 72.

The CPU 71 calculates coordinate values from the voltage values and transmits the results to the copying machine via the serial communication interface 74. The CPU 1 also includes an input port 81 for editor operation section switches, and an output port 8 for editor operation section LEDs.
Data input/output to/from the operating section 8 is performed via the terminal 2.

Furthermore, the CPU 71 is also connected to a comparator 71a shown in FIGS. 3 and 6 for detecting presses on the editor input surface.

Here, FIG. 8 shows a serial communication time chart between the editor and the copying device.

As shown in FIG. 8, the copying machine (not shown) periodically turns on the REQ signal to the editor. The editor is
After confirming that the REQ signal is on, immediately turn on the ACK signal.

The copying device outputs byte data B after confirming that the ACKC signal is on.
Send O to B7 to the editor. Also, the editor is also
After turning on the K signal, send 8 bytes of data to the copying machine.

The copying machine turns off the REQ signal after receiving the 8-byte data from the editor. Further, the editor also turns off the ACK signal after receiving 8-byte data from the copying machine and confirming that the REQ signal is turned off.

FIGS. 9A and 9B show serial communication data formats between the editor and the copying device. As shown in the figure, both data are in the form of packets, and byte B is sent and received.
O to B7 are composed of 8 bits b7 to bO, and the following information is assigned to each bit.

In the editor transmission data in FIG. 9(A), byte B
Bits b1 and bO of O are control flags, and EDO
It is N%EDPICK.

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 EDP I CK is a flag indicating whether fixed coordinate data has been input. Each bit of the next byte B1 indicates the operating state of each input key of the operating section 8. Bytes B2 and B3 express the distance using each nibble (half byte) as a BCD code, and each express the X coordinate by a straight line distance. Bytes B4 and B5 similarly represent the X coordinate.

On the other hand, in FIG. 9(B), bit b of byte BO
O 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.

In the above, the comparator reference voltage V REF is changed by the variable resistor R2, but the contact detection voltage Vi is input to the A/D converter, and its digital value is compared with a certain reference value by software inside the CPU. When performing contact detection, a configuration in which the reference value is made variable by setting a dip switch or the like may be considered.

Next, the overall operation of the above configuration will be explained with reference to the flowchart shown in FIG. Figure 10 is C of Figure 7.
The control procedure of PU71 is shown.

First, in step S1, the output of the comparator 71a is "0"
If it is "0", it is determined that the coordinates are manually operated and moves to the next step, and if it is "1", it is assumed that there is no coordinate input, and the comparator output becomes "0" (coordinates are manually operated). ) wait.

If it is determined in step S1 that the coordinates are manually operated, the process moves to step S2. In step S2.3, the X and Y components of the coordinate values are calculated using the method described above, and in step S4, the calculated coordinate values are transmitted to the copying machine. In step S5, the coordinate confirmation flag EDP of FIG. 9(B) is
ICK is set to "1" and that information is also transmitted to the copying machine.

Thereafter, in step S6, the system waits until the coordinate reception end flag PKCATCH sent from the copying machine becomes "1", and in step S7, the coordinate reception end flag PKCATCH is set to "1".
When TCH=1 is received, coordinate confirmation flag EDP I
CK is set to "0" and the information is transmitted to the copying machine.

Next, in step S8, the coordinate reception end flag PKC is
Wait until ATCH becomes "0" and then proceed to step S.
At step 9, after confirming that the comparator output is "1" (the input pen is released from the tablet), the editor enters the state of accepting new coordinate data.

According to the above embodiment, the reference value for identifying valid input of the comparator 71a, that is, the threshold value of the pressing force for valid input, can be set as desired, so that input can be performed without any discomfort. This has an excellent effect.

In the above, a configuration was shown in which the change in contact resistance according to the pressing force of the x and y resistors is input to the comparator to identify valid input, but as shown in FIG. 11, an empty channel of the 8-channel multiplexer 88 is used. Then, the voltage on the ground side of the y resistor is input via the A/D converter 85, and the voltage on the ground side of the y resistor is input to the CPU 71.
Valid input may be detected by comparing it with a predetermined reference value using software. With this configuration, the reference value corresponding to the pressing force threshold can be switched by software. The reference value can be set using a keyboard such as a numeric keypad or dip switch.

[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 at a predetermined distance apart, and the resistor sheets are pressed down from one side to bring the opposed resistor sheets into contact with each other. In the coordinate human-powered device that manually inputs the coordinate value of a pressed point based on a resistance value change detected by the resistor sheet, the control means validates the input information when the pressing force of the resistor sheet is equal to or more than a predetermined value; Since the configuration includes a means for variably controlling a predetermined value for , the operator can set the pressing force of the resistor sheet for effective input as desired according to the variable control means. A coordinate manpower device with excellent operability can be provided.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the configuration of a tablet of a coordinate human power device employing the present invention, Fig. 2 is an exploded perspective view of the device shown in Fig. 1, and Fig. 3 is a circuit diagram showing the principle of the device shown in Fig. 1. , Fig. 4 is a diagram showing the coordinate detection principle of the device shown in Fig. 1, Fig. 5 is a diagram showing the relationship between the pressing force of the resistor and the contact resistance, and Fig. 6 is a diagram showing the principle of coordinate detection of the device shown in Fig. 3. FIG. 7 is a block diagram showing the configuration of the control system of the coordinate input device according to the present invention; FIG. 8 is a timing chart of serial communication between the copying machine and the coordinate input device; FIG. 9 is a circuit diagram showing the operation. (A) and (B) are explanatory diagrams of the data format of serial communication between the copying machine and the coordinate input device, FIG. 10 is a flowchart diagram showing the control procedure of the device according to the present invention, and FIG. It is a circuit diagram showing an example of. 1...Protection sheet 2...X resistor sheet 3
...y resistor sheet 4...dot spacer 5.
...Metal plate 6...Input pen 7...Input surface 8...Operation unit 9...Recesses 51-54...Multiplexer 55...A/D converter 56...CPU 57...・Gate 62
-RAM 63 ・ROM2S... Comparator 81... Person oyster - 82... LED Shihata Sat n j Koshi n B □ 11 Indication of Lugo Ding 8 of the 5th generation of clams 'Hi, Bo moxibustion, door] 50th REQ Fig. 8 A [f sect

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 change in resistance detected through the resistor sheet, the pressing force of the resistor sheet is set to a predetermined value. A coordinate input device comprising: a control means for validating input information when the input information is equal to or greater than a value; and a means for variably controlling the predetermined value for validation.