JPS6224810B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a coordinate input device that detects coordinate information of a pressurized position by pressurizing a writing instrument or the like.

(Background Art) In devices for inputting characters and figures into a computer or the like, such as a handwritten character input device, a coordinate input device using an input panel has conventionally been used as a device for detecting the coordinates of a pen position.

FIG. 1 is a block diagram showing an example of a conventional coordinate input device, in which 1 is a resistive film closely attached to an insulating substrate, 2 is an AC power supply, and 3, 4, 5, and 6 are diode groups. The anodes of the diode group 3 and the cathodes of the diode group 6 are commonly connected and connected to one side of the AC power source 2. Also, diode group 3
The cathodes of the diode group 4 located opposite to the diode group 6 and the anodes of the diode group 5 located opposite the diode group 6 are also commonly connected and connected to the other side of the AC power source 2 and grounded. 7, 8,
9 and 10 are terminal groups provided on the resistive film 1, respectively. The terminal group 7 is grounded to the cathode of the diode group 3, the terminal group 8 is connected to the anode of the diode group 4, and the terminal group 9 is grounded to the cathode of the diode group 4. The terminal group 10 is connected to the anode of the diode group 6. 11 is a pen and 1
2 and 13 are diodes, and 14 and 15 are terminals. Diode 1 is connected by a conductor from the tip of pen 11.
The anode of the diode 12 is connected to the terminal 14, and the cathode of the diode 13 is connected to the terminal 15.

Therefore, when one point on the resistive film 1 is pressurized by the pen 11, and the AC power source 2 is negative, the diode groups 3 and 4 are cut off and the diode groups 5 and 6 are made conductive. Therefore, the negative voltage at the pressure point is transmitted to the pen 11, and a negative voltage corresponding to the pressure point is outputted to the terminal 14 through the diode 12.

Conversely, when the AC power supply 2 is positive, diode groups 5 and 6 are cut off, diode groups 3 and 4 are conductive, and the positive voltage at the pressurizing point is transmitted to the pen 11 and pressurizes the terminal 15 through the diode 13. A positive voltage corresponding to the point is output.

Here, since the terminal groups 7 and 8 are installed at opposite ends of the resistive film 1 in the Y direction, and the terminal groups 9 and 10 are installed at opposite ends of the resistive film 1 in the X direction, The negative voltage applied to the terminal 15 represents the X-axis coordinate, and the positive voltage derived to the terminal 15 represents the Y-axis coordinate. In this way, the coordinates of both the X and Y axes are detected, but in the conventional coordinate input device, the input pen is moved by contact between the resistive film 1, which is the input panel, and the pen 11, which is the input pen. The coordinates were detected through the

However, in the case of the coordinate input device, since opposing electrodes in the X and Y directions are formed on one resistive film, when a voltage is applied between one terminal group, the voltage is passed between the terminal groups to which no voltage is applied. This has the serious disadvantage that a current wraparound phenomenon occurs, and it is difficult to obtain a surface with an ideal constant potential gradient, that is, an equipotential surface, and the accuracy of coordinate position is reduced.

(Problems to be solved by the invention) The purpose of the present invention is to eliminate these drawbacks by applying a potential to a position corresponding to the pressing point of a parallel conductor provided in the X and Y directions without depending on the resistive film, and The coordinates of the pressure point are detected by detecting which of the conductors the pressure is applied to, and in order to prevent the peripheral circuits from increasing even if the number of parallel conductors increases, the parallel conductors are grouped into groups of a certain number and their By connecting each unit of parallel conductors with a constant resistance, a potential tail is generated in the detected potential,
By converting the voltage into a digital value, it is possible to detect which portion of the parallel conductor is being pressed, and will be explained in detail below.

(Structure and operation of the invention) FIG. 2 is a block diagram of an embodiment of the present invention.
6 is an X detection surface in which a large number of printed patterns (parallel conductor groups) are arranged in the X direction on an insulating substrate, 17, 19
18 is a conductor film, and 20 is a Y detection surface in which a large number of printed patterns (parallel conductor groups) are arranged in the Y direction on the back surface of a flexible insulating substrate. FIG. 3 is a block diagram of the present invention, in which 21 is a power supply, 22 is an analog switching circuit (hereinafter referred to as A-EXG), 23 is an encoder, 2
4 is an analog selection circuit (hereinafter referred to as A-SEL);
25 is an analog-digital converter (hereinafter referred to as
26, 27, 28, 29 are print pattern groups, 30 to 33 are output lines of A-EXG 22, 34, 35 are output lines of encoder 23, 3
6 is the output line of A-SEL24, 37 and 38 are ADC
25 output lines are shown.

The operation of the present invention will be explained below.

When pressed from the upper part of the Y detection surface 20 with a writing instrument such as a ballpoint pen, the printed pattern on the Y detection surface 20, the pressure sensitive rubber 19, the conductive film 18, and the pressure sensitive rubber 1 are pressed.
7. The printed pattern on the X detection surface 16 is electrically conductive. Since a potential is now applied to the conductor film 18, the potential E supplied by the power source 21 to the pressed point P on the printed pattern on the X detection surface 16
is applied.

Now, referring to FIG. 3, details of the X detection surface 16 will be explained.

In FIG. 3, the printed pattern group 26 is composed of four (generally M) parallel conductors, each connected to a resistor r, and the other end of each resistor r connected to the printed pattern group 27. Print pattern groups 26, 27, 28, 29
are connected in series with each other through a resistor r, and A-
Connected to EXG22. If there are N parallel conductor groups with M conductors in one group, the total number of conductors is M×
It is N.

The pressing point P is located above one line on the print pattern group 27, and a potential E is applied thereto. A-
EXG22 is a switching circuit that switches the analog voltage, and when switching is currently being performed in the X direction, the printed pattern group 29 is connected to the resistor R through A-EXG22. Here, since the other end of the resistor R is grounded, a voltage of ExR/R+2r [V] appears on the extension line 31 of the output lines 30 to 33 of A-EXG22, and the voltage of ExR/R+2r [V] appears on the other lines 30, 32, and 33. is O
A voltage of [V] appears. These A-EXG22
The output of is input to the encoder 23, and only the line 31 has voltage, and the other lines 30, 32, and 33 are O [V], so the value of the output of the encoder 23 is 1,
The lower bit line 34 becomes a logic "1" and the upper bit line 35 becomes a logic "0". It is assumed that the input of the encoder 23 is set so that even a voltage of ExR/R+3r is treated as logic 1. This makes it possible to indicate which of the M conductors the pressurizing point corresponds to.

Now, the lines 34 and 35 become switching signals for the A-SEL 24, and since the line 34 is logic 1 and the line 35 is logic 0, the voltage of the line 31 is output to the output line 36 of the A-SEL 24 and input to the ADC 25. ADC25 is
When the voltage of the line 36 becomes E [V], the output line 37 receives a logic 1 (hereinafter referred to as "1"; similarly, a logic 0).
is called "0", and when lines 37 and 38 are "1" and "0", it is expressed as "10"), and at the same time, "1" also appears on line 38, and as a result, ADC2
The ADC 25 operates so that the output of 5 becomes "11". Similarly, the input line 36 of the ADC 25 is E・R/R+r[V
], E·R/R+2r [V], and E·R/R+3r [V], the output lines 37 and 38 of the ADC 25 become “10”, “01”, and “00”, respectively. The output of ADC25 is N
It specifies one group in a group. Therefore, when the pressing point P is pressed, the potential E is applied to P, so the output lines 37 and 38 of the ADC 25 become "01", and since the pressing point P is the second line of the print pattern group 27, the encoder 23 Output lines 35, 34
is "01". That is, the position of the pressing point P is expressed by the output of the ADC 25 and the output of the encoder 23, and when the pressing point P is shown in FIG. 3, it is "0101".
So, 5 counting from 0 (0, 1, 2, 3, 4,
When counting 5, 6, etc., 5 indicates the 6th point when counting from 1), and this indicates the correct position more clearly than point P in Figure 3. There is. In this way, the position in the X direction is detected, and then, by replacing the A-EXG 22 with Y, a Y detection surface 20, which is configured similarly to the X detection surface 16 but differs by 90 degrees only in the direction of the printed pattern group, is created.
The position in the Y direction is detected using

(Effects of the Invention) As described in detail above, in the above embodiment, a potential is applied to the parallel conductors of the printed pattern groups 26 to 29, lines to which the potential is applied are detected, and the potentials are further roughly classified to determine which Compared to a method that uses a resistive film to detect whether there is a pressed point in a group of printed patterns, the accuracy of the position is determined by the printed pattern and is extremely accurate, so there is no decrease in coordinate position detection accuracy. do not have. Furthermore, as the number of printed patterns increases, the peripheral circuitry increases, which is impractical, but to prevent this, the printed pattern groups can be identified by connecting the printed pattern groups with a resistor r and roughly detecting the potential at the output terminal. Therefore, the ADC 25 only requires a small number of bits. In other words, in order to realize a coordinate input device with a resolution of 4 points per 1 mm in the size of an A4 sheet, it is necessary to detect 297 x 4 = 1188 points, and if a resistive film is used, an 11-bit analog-to-digital converter is required. However, if the number of print patterns in one print pattern group is 16, then
Since 1188÷16≒74, a 7-bit analog-to-digital converter is sufficient and can be realized at low cost.

In the embodiment described above, the numerals 17 and 19 have been described as pressure-sensitive rubbers that conduct only in the vertical direction, but needless to say, they are not limited to pressure-sensitive rubbers and may be any suitable space. Next, in the embodiment, a large amount of resistors are required to connect the printed pattern groups by resistors r, but these resistors are not limited to individual resistors, but are also provided on insulating substrates and flexible insulating substrates. It should be added that it can be constructed by depositing or coating a resistive material thereon.

Finally, although the print pattern groups 26 to 29 have been described as having 4 or 16 print patterns, the number is not limited to these, and may be any number that is a power of 2 depending on the size and control method of the coordinate input device. An expert in the field can easily deduce that any number is sufficient.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional coordinate input device, FIG. 2 is a sectional view showing some elements constituting an embodiment of the present invention, and FIG. 3 is a block diagram showing an example of the present invention. FIG. 4 is a block diagram showing other elements. 1... Resistance film closely adhered on an insulating substrate, 2...
AC power supply, 3 to 6... Diode group, 7 to 10...
...Terminal group, 11... Pen, 12, 13... Diode, 14, 15... Terminal, 16... X detection surface,
17, 19...Pressure sensitive rubber, 18...Conductor film, 20
... Y detection surface, 21 ... Power supply, 22 ... Analog switching circuit, 23 ... Encoder, 24 ... Analog selection circuit, 25 ... Analog-digital converter, 26, 27, 28, 29 ... Print pattern group , 30-38... Output line.

Claims (1)

[Claims] 1 In a coordinate input device that has an input panel, a pressurizing body that pressurizes the input panel, and an electric circuit that gives the coordinates of the input panel pressurized by the pressurizing body, the input panel has M×N parallel to the surface. A first insulating substrate having a group of conductors (M, N are natural numbers), a second insulating substrate having a group of parallel conductors in a direction perpendicular to the group of parallel conductors, and a conductor film inserted between each insulating substrate, and the conductor. means inserted between the membrane and each insulating substrate to electrically connect the conductor membrane and one of the group of parallel conductors at a pressurizing point; Resistance r for each M parallel conductor in the conductor group
an encoder that detects which of the M parallel conductors at the outermost end is applied with a potential, and an encoder that outputs a digital value according to the potential applied to the parallel conductor. and an analog-to-digital converter for specifying one group among the N groups of parallel conductors, and the output of the encoder and the output of the analog-to-digital converter provide the coordinates of the pressurized point on the input board. A coordinate input device characterized by: