JPS6266320A - Graphic information input device - Google Patents

Abstract

PURPOSE:To eliminate the need for position adjustment by performing correction arithmetic based on the maximum and minimum values of actual position coordinate information obtained by pressing respective end parts of the X- and Y- directional effective input range on an input board and a previously stored reference maximum value. CONSTITUTION:A correcting circuit 9 is provided with the 1st storage circuit 7 stored with reference maximum values of pieces of position coordinate information in the X and Y directions of the effective input ranges of a conductive sheet 1 and a resistance sheet 2 and the 2nd storage circuit 8 stored with respective pieces of position coordinate information obtained by a depression position detecting circuit 5 when respective end parts in the X and Y directions of the effective input range are pressed individually. This correcting circuit performs the correction arithmetic of position coordinate information obtained by the depression position detecting circuit when one optional point in the effective input range is pressed on the basis of the reference maximum values and position coordinate information stored in the 1st and the 2nd storage circuits.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an improvement in a graphic information input device for inputting, for example, handwritten characters and graphics.

[Technical background of the invention]

2. Description of the Related Art In recent years, devices for inputting graphic information by detecting handwriting such as characters and figures written on an input panel have become known. This type of device generally has a pair of planar electrodes facing each other while maintaining an electrically insulated state, and conduction occurs when one point of these planar electrodes is pressed to create continuity between each planar electrode. Written information is input by electrically detecting the coordinates of a position.

Figure 2 schematically shows the circuit configuration of this type of input device. Of the conductive sheet j-1 and resistor sheet i-2 that make up the input panel, conductive sheet 1 is grounded and the resistor A detection electrode X1 is provided on each side of the body sheet 2. X2. Yl,
Y2 are provided, and among these detection electrodes, electrodes X1 . X2, Yl, and Y2 are connected to each other and are selectively connected to a constant current source IQ by switch SW1.
is connected to. In addition, a detection resistor Rx1.
Rx2. A voltage drop across Rx2°Ry2 of these detection resistors is detected by differential amplifiers AX and Ay. Incidentally, FIG. 3 shows an example of the structure of the input panel, in which a resistor sheet 2 is disposed on the surface of a conductive sheet 1 with insulating projections 3 interposed therebetween. That is, the conductive sheets 1-1 are the fill 11
A planar electrode 12 with a protective film 12b formed on a conductive layer 12a is provided on the surface of a base material 11, and a large number of insulating protrusions 3 are arranged at equal intervals over the entire surface of the planar electrode 12.
Board 1 with a thin iron plate 13 as a magnetic material glued to the surface
4 with adhesive tape 15. On the other hand, the resistor sheet 2 has a resistor M22 formed on the back surface of a flexible film base material 21, and a resistor M22 formed on the front surface for protecting the input surface.
-1- Material 23 is applied.

However, in such a configuration, when an arbitrary point P on the input panel is pressed with the input pen 4 as shown in FIG.
The resistor layers 22 of the resistor sheets 1 and 2 contact the flat electrodes 12 of the conductive sheet 1, and the resistor layers 22 pass through this contact point.
A constant current from a constant current source 10 flows between the flat electrodes 12 and 12 . At this time, this constant current is shunted and outputted from the detection electrodes x1, x2 and Yl, Y2 according to the contact position P, and this shunted current IX1. IX2 and Iyl
.

One of Iy2 is a detection resistor RX2. It is detected as a voltage value by differential amplifiers Ax and Ay via RV2. In addition, the above X direction and Y direction
Detection of each shunt current value in each direction is performed separately for each of the X direction and the Y direction by switching the switch SW1. The detected voltage values in the X and Y directions, that is, the coordinate information of the pressed position P, are alternately supplied to the analog-to-digital converter (A/D) 5 by the switch SW2.
Here, the signal is converted into a digital signal and then sent via a communication line by a transmitter (not shown) to a distant monitor device for display.

On the other hand, if you want to erase input characters, for example, switch the changeover switch on the operation panel to the erase side, erase the blackboard, and rub any area on the input surface to specify the erasing range, and then send this information to the control unit (not shown). By detecting this, the written information in the corresponding area is erased.

In this way, by using this input device, just by writing characters or figures on the input board with a pen, the coordinate information of this writing trajectory is sent to a distant monitor device and displayed. This is extremely convenient, as staff can hold meetings while staying in remote locations without having to gather in one place.

[Problems with background technology]

However, such conventional devices have the following problems. That is, the resistor sheet 2 generally has variations in resistance value, and each detection electrode X1. X2. Y
1. The installation position of Y2 also often has a positional shift. Therefore, if the position coordinates of the pressed position are detected in this state, a discrepancy will occur between the detected position coordinate values and the actual coordinate values of the pressed position, which is very undesirable. Therefore, in the past, for example, as shown in FIG.
The position coordinate values are corrected by adjusting the resistance values of the variable resistors 6x and 6y and setting the offset value to an appropriate value during manufacturing. However, devices with such conventional correction functions use variable resistors 6x and 6y.
Adjustment is a complex and delicate task, which increases the burden on the operator and reduces productivity, and it is difficult to perform highly accurate adjustment. Furthermore, even if highly accurate adjustments are made during manufacturing, the correction values may change due to changes in the resistance values of the variable resistors 6x and ey over time. It was very tedious work as I had to readjust the settings.

(Objective of the Invention) The present invention provides a graphic information input device that greatly simplifies the adjustment work during manufacturing and eliminates the need for adjustment work during use, thereby enabling accurate correction at all times during the adjustment work. The purpose is to provide.

(Summary of the Invention) In order to achieve the above object, the present invention provides a first memory that stores reference maximum values of positional coordinate information in the X direction and Y direction of the effective input range to the conductive sheet and the resistor sheet.
a second memory circuit that stores each position coordinate information obtained by the pressed position detection circuit when each end of the effective input range in the X direction and the Y direction is individually pressed; and a correction circuit. With this correction circuit,
The positional coordinate information obtained by the pressed position detection circuit when any point in the effective input range is pressed is corrected based on the reference maximum value and positional coordinate information stored in the first and second storage circuits. It is designed to perform calculations.

[Embodiments of the invention]

FIG. 1 shows a circuit configuration of a graphic information input device in an embodiment of the present invention. In this figure, the same parts as in FIG. 2 are given the same reference numerals and detailed explanations will be omitted.

This device includes a first storage circuit 7 consisting of a ROM, and a RAM
It has a second memory circuit 8 and a correction circuit 9, of which the second memory circuit 8 and the correction circuit 9 have
Device coordinate information constituted by the A/D converter 5 is supplied via the changeover switch SW3. 1st
The storage circuit 7 stores the reference maximum value Z
V p is stored in advance. -5 The second memory circuit 8 stores information in the X direction and Y direction of the effective input range of the input panel.
Each position coordinate information obtained from the A/D converter 5 when each end in the direction is pressed, that is, the maximum value Zx2 of each position coordinate information in the X direction and Y direction of the effective input range
．． Zy2 and minimum values ZX1 and Zyl are respectively stored. In addition, the correction circuit 9 receives position coordinate information obtained from the A/D converter when any one point in the effective input range is pressed.
N.

yN is corrected based on the reference maximum value of the position coordinate information stored in the first and second storage circuits 7.8 and the maximum and minimum values of the actual position coordinate information obtained from the input panel. The operation is XM= ((XN −7x
1) / (Zx 2-7x 1)) XZXp ・”(
1) VM-((VN-Zyl)/(ZV2-zyl))XZVp (2).

Because of this configuration, when a manufacturing worker wants to adjust the position coordinate information, he or she should switch the selector switch SW3 to the second memory circuit 8 side, and in this state change the input panel's effective input range in the X direction. and each end thereof in each Y direction, for example, Px2 in the figure. Pxl and Py2. Press Pyl individually. Then, for each pressing position, the maximum value Zx2. Zy2
and minimum values ZXI and Zll are output, and these values are stored in the second storage circuit 8, respectively. After completing this memorization, the operator switches the changeover switch SW3 to the correction circuit 9 side and fixes it there, thereby completing the adjustment work. That is, the operator's adjustment work is simply to cause the second storage circuit 8 to store the positional coordinate information of each end in the input effective range of the input panel.

By making such adjustments, when the operator presses any point on the input panel with the input ben 4 during use, the position coordinate information of this pressed position is output from the A/D converter 5 and then Correction circuit 9 via changeover switch SW3
guided by. Then, the correction circuit 9 performs a correction calculation according to equations (1) and (2), and the corrected signal is supplied to a transmitter (not shown) and transmitted.

As described above, in this embodiment, the reference maximum value and the actual maximum and minimum values of the effective input range of the input panel are stored in the first and second storage circuits 7 and 8, respectively, and the correction is performed. Since the circuit 9 performs supplementary calculations on the position coordinate information input from the input panel based on these stored values, the operator can easily perform the computation during manufacturing.

It is now necessary to simply write the maximum and minimum values of the actual position coordinate information at each end of the input panel into the second memory circuit 8, which greatly simplifies the adjustment work and reduces the workload. At the same time, the working time is shortened, and as a result, adjustment efficiency can be increased. In addition, since a variable resistor is not used, the correction accuracy will not deteriorate due to changes in the resistance value of this resistor over time, and as a result, the correction accuracy can always be maintained at a high level, and there is no need for readjustment during use. It can be done. Furthermore, even if it becomes necessary to perform readjustment due to replacement of the resistor sheet of the input panel, etc., the maximum and minimum values of the position coordinate information can be written to the second memory circuit 8 in the same way as in the case of manufacturing. This work is extremely easy as all you have to do is

Note that the present invention is not limited to the above embodiments. For example, in the above embodiment, the output of the A/r) converter 5, that is, the digital value, is corrected, but the output (analog value) of the differential amplifiers AX and Ay may also be corrected. good. In this case, either the first and second storage circuits are configured with analog memories, or the information read from the first and second storage circuits is D/A converted.
;Just do it. In addition, if a CPU is provided in the transmitter, etc., the correction calculation of the correction circuit may be performed by this CPU, and in this case, the program memory attached to the CPU serves as the first storage circuit. It is also possible to use a RAM for data storage as the second storage circuit.

In addition, the configuration of the correction circuit and the first and second storage circuits,
The structure of the input panel can also be modified in various ways without departing from the spirit of the invention.

〔Effect of the invention〕

As described in detail above, according to the present invention, the first memory circuit stores the reference maximum value of each position coordinate information in the X direction and the Y direction of the effective input range of the conductive sheet and the resistor sheet, and A second storage circuit that stores each position coordinate information obtained by a pressed position detection circuit when each end in the X direction and Y direction of the layout effective input range is pressed in detail, and a correction circuit are provided. With the correction circuit,
The positional coordinate information obtained by the pressed position detection circuit when any point in the effective input range is pressed is corrected based on the reference maximum value and positional coordinate information stored in the first and second storage circuits. By performing calculations, it is possible to greatly simplify the adjustment work during manufacturing and eliminate the need for adjustment work during use, thereby providing a graphic information input device that allows easy adjustment work and always performs accurate correction. can do.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of a graphic information input device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the circuit configuration of a conventional graphic information input device, and FIG. 3 is a block diagram showing the structure of the input panel. It is a sectional view showing an example. 1... Conductive sheet, 2... Resistor sheet, ×1゜X
2. Yl, Y2... detection electrode, Io... constant current source,
Rx2. Ry2...Resistance for shunt current detection, AX. Ay...Differential amplifier, SWl, SW2. SW3...
Selector switch, 5...Analog-to-digital converter (A
/D converter), 7...first storage circuit, 8...second
memory circuit, 9...correction circuit, ZXp, ZVp...
Reference maximum value of position coordinate information, 7x2. Zy2: Maximum value of actual position coordinate information, Zxl, Zyl: Minimum value of actual position coordinate information.

Claims (1)

[Claims] When a pair of conductive sheets and a resistor sheet are placed facing each other while being insulated from each other, and any point on these sheets is pressed to create a short circuit between the two sheets, a short circuit occurs between the two sheets through this short circuit position. a constant current generation circuit that supplies a constant current to the resistor sheet, and detects the current value of the constant current that is divided by the resistor sheet in each of the X direction of the resistor sheet and the Y direction orthogonal to this, and calculates this current value. a pressed position detection circuit that obtains positional coordinate information of the short circuit position from
A first storage circuit that stores a reference maximum value of each position coordinate information in the direction, and a pressed position detection circuit that is obtained when each end of the effective input range in the X direction and the Y direction is pressed individually. a second memory circuit that stores each piece of position coordinate information; and a second memory circuit that stores position coordinate information obtained by the pressed position detection circuit when any point in the effective input range is pressed, and stores the position coordinate information that is obtained by the pressed position detection circuit in the first and second memory circuits. A graphic information input device comprising: a correction circuit that performs correction calculations based on stored reference maximum values and positional coordinate information.