JPH0553715A - Digitizer - Google Patents

Abstract

PURPOSE:To provide such a digitizer that detects the jump of the coordinates caused in a continuous input state and then invalidates the coordinate data caused by the jump of the coordinates. CONSTITUTION:When the coordinate input sheets 10A and 10B where the stripe electrodes 18 are laminated in the direction intersecting orthogonally with each other are touched with fingers, the coordinate data are fetched by a CPU 15. The CPU 15 computes the correlativity of the continuous coordinate data based on the increase quantity and the increase-decrease relation of data. Then the CPU 15 skips the improper coordinate data when supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called digitizer used as an input device for handwritten characters and figures, and particularly when a figure is input to a computer or only a partial area of a printed matter by a copy machine. The present invention relates to a digitizer provided with a coordinate input sheet used when specifying each coordinate input data to specify and copy.

[0002]

2. Description of the Related Art As a conventional digitizer, for example, there is a digitizer disclosed in Japanese Patent Laid-Open No. 61-104513. In this case, a uniform strip-shaped resistor is formed by applying a resistance film on an insulating substrate by using a mask, coating, printing, vapor deposition, sputtering, and the like.

Another conventional example is Japanese Patent Laid-Open No.
In the digitizer using the coordinate input sheet disclosed in Japanese Patent No. 2-184512, two coordinate input sheets 1A and 1B are provided as shown in the principle diagram of FIG.
Each of the coordinate input sheets 1A and 1B has electrodes 2 and 3 facing each other at both ends of an insulating sheet, and a surface resistance 4 is formed between the electrodes. These two coordinate input sheets 1A and 1B are vertically arranged, respectively. The electrode directions are overlapped with each other by 90 degrees, and they are used, for example, for detecting the X-coordinate position of the contact point for pressing the lower coordinate input sheet 1B and for detecting the upper coordinate input sheet 1A.

That is, when the coordinate input sheet 1A is brought into contact with an arbitrary point P in FIG. 3, a voltage 5A is applied to the upper coordinate input sheet 1A to cause the sheet 1A to move.
The partial pressure at the finger contact input point P at is extracted from the partial pressure output end 6 of the lower coordinate input sheet B as X-axis coordinate position data.

Next, when the voltage 5B is applied to the lower coordinate input sheet 1B, the partial pressure at the finger contact input point P on the lower coordinate input sheet 1B is changed to the partial pressure output end 7 of the upper coordinate input sheet 1A.
Is taken out as Y-axis coordinate position data, and the position on the XY coordinate of the finger input point P is obtained by such time division.

In the conventional example of FIG. 3, since it is necessary to insulate between the two coordinate input sheets, each coordinate input sheet 1
A dot spacer 30 as shown in FIG. 4 is provided between A and 1B to form the gap 10 between each coordinate input sheet.

[0007]

However, when the trace is continuously traced on the sheet, the correct voltage cannot be read at the coordinate position pointed to on the dot spacer 30, so that in the case of continuous input. There was a problem that only the points would cause coordinate jumps and correct coordinate detection could not be performed.

The present invention has been made in order to overcome the drawbacks of the prior art, and a digitizer capable of skipping the coordinate data when a finger is touched on the dot spacer in the case of continuous input. The purpose is to provide.

[0009]

The digitizer of the present invention comprises:
A digitizer in which two sheets of strip resistors and strip electrodes are laminated in a direction in which the strip resistors of the respective sheets are alternately orthogonal to each other, and which has dot spacers for insulating the sheets from each other. It is characterized by further comprising a control means for calculating the correlation between the coordinate detection data to detect the coordinate jump.

[0010]

In the digitizer having the above-mentioned structure, the control means detects the coordinate jump from the correlation of the continuous coordinate detection data, and makes the coordinate detection data judged as the coordinate jump invalid data.

[0011]

FIG. 1 is a circuit block diagram showing the configuration of an embodiment of a digitizer of the present invention. The digitizer has two coordinate input sheets 10A for X and Y coordinates which are arranged orthogonally to each other by 90 °. 10B and the coordinate input sheets 10A and 10B
Switching circuits 11, 12, 13 connected to the switching circuit, and switching circuit 1
2, an A / D converter 14 for converting analog signals of X and Y coordinates input from 2 into a digital signal, and a CPU 15 as control means connected to the A / D converter 14.
It is roughly composed of and.

The uniform resistors 17, 17 which are strip-shaped resistors of the coordinate sheets 10A, 10B are each divided into four by five drive electrodes 16, and a voltage Vcc is separately applied between the drive electrodes. Switch circuit 11, 1
Three contact points a to d are provided.

The voltage application contacts A and D of the switching circuits 11 and 13 are connected so as to be supplied with a voltage Vcc (5 [V] in this embodiment), and a ground contact B for grounding,
E is provided. In addition, the switching circuits 11 and 13
Are provided with switches 11a, 11b and 13a, 13b which are opened and closed under the control of the CPU 15.

In the switching circuit 12, the input points of the coordinate input sheets 10A and 10B for detecting the positions of the X and Y coordinates by the pen or the pressed finger are individually obtained.
A switch 12a for selecting the contacts a, b, c, d for the coordinate input information from the coordinate input sheets 10A, 10B and the voltage information applied to each block under the control of the CPU 15 is provided. This is a contact for analog signal input.

Further, the coordinate input sheet 10A detects a pressing input point having a Ly width on the Y-axis, and the coordinate input sheet 1
0B is configured to detect a pressing input point of LX width on the X axis.

Further, in the figure, 18, ... Are silver stripe electrodes.

The flow of the digitizer in this embodiment having the above construction will be described with reference to the flow chart shown in FIG. First, in step 100, the CPU 15 causes the A-open, B-open, C-a, D-a, and E-o.
pen control is performed, and the coordinate detection signal at the position where the finger is touched is set as an analog signal pressing voltage via the switching circuit 12
It is input to the / D converter 14.

In step 101, the A / D converter 1
The pressing voltage V input to V.4 is V> Vcc (5V) -0.
When it is 5V, that is, V> 5V-0.5V = 4.5 [V], the CPU 15 determines that there is a depression (YES), and proceeds to the next step 102. Also, in step S101,
When the pressing voltage V is the applied voltage Vcc [5V], V ≦ Vcc
-0.5V, that is, V≤5V-0.5V = 4.5
When it is [V], the CPU 15 judges that there is no depression (NO),
Returning to step 100, the press detection is repeated as described above.

In step 102, the coordinate input sheet 10
The block on B where the input point is located is searched. Here, the CPU 15 sets each switch to A-op.
en, B-open, C-a, D-a, E-d, and the position on the X coordinate of the input point is input as an analog signal from the a contact of the switching circuit 12 to the A / D converter 14. After being converted into a digital signal, the calculation unit of the CPU 15 performs a calculation of the formula X = Lx × (V / Vcc) to determine which block of the X coordinate the input point is.

Next, at step 103, the coordinate input sheet 1
It is searched for in which block on 0A the input point exists. Here, the CPU 15 sets each switch to A-
a, B-d, C-c, D-open, and E-open are controlled, and from the b contact of the switching circuit 12 to the A / D converter 14
After the position of the input point on the Y coordinate is input as an analog signal and converted into a digital signal, the calculation unit of the CPU 15 performs the calculation of the formula Y = Ly × (V / VCC) and inputs it. It is determined which block on the Y coordinate the point is.

Further, in step 104, the determined X
A voltage Vcc (5V) is applied to the block of coordinates. At this time, each switch is set to A-open and B by the CPU 15.
-Open, D-c, E-c, switch C first c
Connect to and read the voltage on the Vcc side of the block (VXH), then switch to d to read the voltage on the ground side (VXL), and finally switch to a and divide the voltage at the input position (VX)
Read. Thus, when an input signal composed of an analog signal on the X coordinate is input to the A / D converter 14, the analog signal is replaced with a digital signal and the CPU 15
To enter.

Next, at step 105, the coordinate position on the X coordinate thus input is calculated by the calculation unit of the CPU 15 using X = Xn + Lxn. (VX-VXL) / (VXH-VXL). , The position of the input point on the X coordinate is determined.

Next, the process proceeds to step 106, where the CPU 15
Switches each switch to A-b, B-b, C-b, D-ope
The voltage Vcc (5V) is applied to the block of the Y coordinate determined as n and E-open. Then step 107
Then, the CPU 15 first connects the switch C to a and reads the voltage (VYH) on the Vcc side of the block, then switches to b and reads the voltage on the ground side (VYL), and finally switches to c to select the input position. Read the pressure voltage (VX). The coordinate position on the Y coordinate thus input is obtained by the arithmetic unit of the CPU 15 by Y = Yn + Lyn. (VY-VYL) / (VXH-VXL), and the position on the Y coordinate of the input point is determined. ..

Although the currently input coordinates are determined by the flow up to this point, the flow after step 108 is further executed in order to detect the coordinate jump which occurs when the dot spacer is touched. That is, in step 108, the CPU 15 refers to a memory (not shown) that stores the coordinate position detected in the past, and whether or not the coordinate value detected two times before and the coordinate value detected one time before exist. If any coordinate value does not exist, the process returns to step 100.

On the other hand, if the coordinate value of the previous two coordinate values and the coordinate value of the previous one exist, the process proceeds to step 109, and the CPU 15 determines whether or not the coordinate skip has occurred.
If no coordinate jump has occurred, step 110
Then, the coordinate value detected immediately before is transmitted as valid data and stored in a memory (not shown). If it is determined that the coordinate skip has occurred, the coordinate value detected immediately before is ignored and the process returns to step 100.

Here, the principle of detecting the coordinate jump in step 108 will be described. Let P0 (X0, Y0) P1 (X1, Y1) P2 (X2, Y2) be the past two coordinate data and the current coordinate data stored in the memory. DX0 = X1 -X0 dY0 = Y1 -Y0 The change in the X coordinate and the Y coordinate at this time is dX1 = X2 -X1 dY1 = Y2 -Y1. In the case of continuous input, assuming that a range appropriate for the change of coordinates is a, dY0 / dX0> a and dY1 / dX1 <-a (1) dY0 / dX0 <-a and dY1 / dX1> a ... ( 2) dX0 / dY0> a and dX1 / dY1 <-a (3) dX0 / dY0 <-a and dX1 / dY1> a (4) If any of the above four conditions is satisfied, the CPU
15 determines that the coordinate jump has occurred and skips the coordinate P1.

Further, X1> X0 and X1> X2 and Y1> Y0 and Y1> Y2 (5) X1> X0 and X1> X2 and Y1 <Y0 and Y1 <Y2 (6) X1 <X0 and X1 < X2 and Y1> Y0 and Y1> Y2 (7) X1 <X0 and X1 <X2 and Y1 <Y0 and Y1 <Y0 (8) If any of the above four conditions is satisfied, the CPU
15 determines that the coordinate jump has occurred and skips the coordinate P1.

As described above, the CPU 15 determines whether the correlation of three consecutive data is appropriate, and if it is determined that the correlation is not appropriate, the coordinate value is skipped. In the above embodiment, three consecutive phases are used.
Although the coordinate jump is discriminated from one coordinate data, it goes without saying that the coordinate skip may be discriminated from the correlation of more continuous coordinate data.

[0029]

As described above, according to the digitizer of the present invention, the control means determines the correlation between consecutive coordinate data.
Since the coordinate jump that occurs during continuous input is detected,
Even when correct coordinate data cannot be obtained as in the case where the dot spacer is touched, only correct coordinate data can be obtained by skipping this.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a digitizer of the present invention.

FIG. 2 is a flow chart for explaining the operation of the digitizer shown in FIG.

FIG. 3 is a principle diagram of a digitizer using a conventional coordinate input sheet.

FIG. 4 is a cross-sectional view of a conventional digitizer.

[Explanation of sign]

 10A, 10B Coordinate input sheet 15 CPU (control means) 17 Strip resistor 18 Striped electrode 30 Dot spacer

Claims (1)

[Claims] 1. A digitizer having two sheets each composed of a strip resistor and a striped electrode, laminated in a direction in which the strip resistors of the respective sheets are alternately orthogonal to each other, and having a dot spacer for insulating the sheets from each other. The digitizer is characterized by comprising control means for calculating a correlation between consecutive coordinate detection data to detect a coordinate jump.