JPS5835679A - Coordinate input device due to switching of switch - Google Patents

Abstract

PURPOSE:To output a coordinate position with a high precision, by using one resistance film and one conductor film and applying the voltage of a DC power source to the resistance film in time division in longitudinal and lateral directions and detecting the potential at a pressurized point in longitudinal and lateral directions independently of each other by a writing tool. CONSTITUTION:A resistance film 19 is formed on an insulating substrate 20, and an insulating film 16 provided with a conductor film 17 on the rear face is arranged on the surface of the film 19 through a pressure sensitive rubber 18. Terminal groups 21-24 are provided in the peripheral part of the surface of the resistance film 19, and terminal groups 21-24 are connected to respective terminals of analog switch groups 25-28 in a ratio of 1:1. Analog switches 30 and 31 are connected to a DC power source 29, and switches 30 and 31 are connected to switches 26 and 27, and switches 25 and 28 are connected to the negative pole of the power source 29 and are grounded. A current is flowed to the resistance film 19 from the power source in time division in longitudinal and lateral directions through switches 25 and 28, switches 30 and 31, and switches 26 and 27, and thus, coordinates of a pressurized point 34 of a writing tool 33 are detected with a high precision.

Description

[Detailed Description of the Invention] The present invention provides coordinate information of a pressurized position by pressurizing a writing instrument or the like. This invention relates to a coordinate input device for detection.

In a device 9 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 board 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 numeral 1 denotes a resistive film closely attached to an insulating plate.

2 is an AC power supply, 3, 4, 5.6 is a group of diodes,
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. Further, the cathodes of the diode group 4 located opposite to the diode group 3 and the anodes of the diode group 5 located opposite to 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
．． Reference numerals 10 denote terminal groups provided on the resistive film 1. The terminal group 7 is connected to the cathode of the diode group 3, and the terminal group 8 is connected to the anode of the diode group 4.

Terminal group 9 is connected to the cathode of diode group 5, and terminal group 10 is connected to the anode of diode group 6.

11 is a pen, 12 and 13 are diodes, 14.
15 is a terminal.

The tip of the pen 11 is connected to the cathode of the diode 12 and the anode of the diode 13 by a conductive wire.
The anode of the diode 2 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 with the pen 11, when the AC power supply 2 is negative, the diode group 3 and 4 are in a cut-off state, and diode groups 5 and 6 are in a conductive state. Therefore, a 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, the diode groups 5 and 6 are cut off, the diode groups 3 and 4 are conductive, and the positive voltage at the pressurizing point is transmitted to the pen 11, and the diode 1
A positive voltage corresponding to the pressurizing point is output to the terminal 15 through the terminal 3.

Here, 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, so that the terminals 14 are The negative voltage applied represents the Xi coordinate, and the positive voltage derived at terminal 15 represents the Y-axis coordinate.

In this way, the coordinates of both the X and Y axes are detected.

In the conventional coordinate input device, the coordinates are detected through the input pen by electrical conduction caused by contact between the resistive film l, which is the input panel, and the pen 11, which is the input pen.

Therefore, the input pen has the serious drawback that it requires a connection cord and has poor operability. Furthermore, the coordinate input device has an unacceptable drawback in that it is not possible to place a form between the input panel and the input pen, and it is not possible to make a copy of the characters input into the handwritten character input device. A method has also been proposed in which a form is inserted between the input panel and the input pen, and the coordinate position 'ff: is detected by capacitive coupling without relying on conduction in order to input data while taking notes. The only solution was that the circuit was expensive and lacked practicality.

Furthermore, in the case of the coordinate input device, X,
Since opposing electrodes are formed in the Y2 direction, when a voltage is applied between one group of terminals, a current wraparound phenomenon occurs between the terminal groups to which no voltage is applied, and the ideal equipotential surfaces are different. It was difficult to obtain a surface on which equipotential lines were formed regularly, and there was a serious drawback that the accuracy of coordinate position decreased.Finally, another major drawback is that since AC power is used as a driving power source, The circuit becomes expensive.

As a result, the widespread use of coordinate input devices has been prevented.

The purpose of the present invention is to eliminate these drawbacks, and by using a DC power supply, using one resistive film and one conductive film, and switching them using an analog switch, the resistive film can be applied in a time-sharing manner in the horizontal and vertical directions. The position of the pressurizing point is detected by passing a current in the direction and detecting the potential of the pressurizing point using a conductive film.By using an analog switch, an ideal equipotential surface is constructed, and the coordinates are It is characterized by maintaining high positional accuracy and will be described in detail below. FIG. 2 is a configuration diagram showing a first embodiment of the present invention.
6 is an insulating film, 17 is a conductive film provided on the back surface of the insulating film 16,
18 is a pressure sensitive comb (rubber that becomes conductive when pressed), 19 is a resistive film, 20 is an insulating substrate, and the insulating film 16 and the conductive film 17 on the back side are made of flexible materials. ing. FIG. 3 is a block diagram of the present invention.
24 is a group of terminals provided on the four sides around the resistive film 19; 25-
28 is an analog switch group, and each analog switch of the analog switch group 25 is connected to each terminal of the terminal group 21 on a one-to-one basis. The analog switch groups 26 to 28 are also connected in pairs to the terminal groups 22 to 24, respectively. 29 is DC power supply, 30°31
3 is an analog switch, 32 is an analog-to-digital converter, 33 is a writing instrument, and 34 is a pressure point to which pressure is applied by the writing instrument 33. Figure 3 shows the analog switch 30.
, the analog switch groups 21 and 22 are closed, and the analog switch 31 and the analog switch groups 23 and 24 are open, indicating the timing for detecting the horizontal coordinates. Depending on the state of the analog switch, the potential of the DC power supply 29 passes through the analog switch 30 and is applied to the terminal group 22 via the analog switch group 26 .

Further, the terminal group 21 is connected to the negative side of the DC power supply 29 via the analog switch group 25, and serves as a return path for the current generated by the potential applied to the terminal group 22. Furthermore, the terminal groups 23 and 24 are respectively connected to the analog switch groups 27 and 28, and the analog switch groups 27 and 28 are connected to the analog switch groups 27 and 28, respectively.
Since all of the analog switches 31 that supply the potential to the terminals 7 are open, there is no current bypassing due to the characteristics of the analog switches themselves, and the current path from the terminal group 22 to the terminal group 22 is disrupted. Therefore, literally an ideal equipotential surface is obtained.

Now, when the pressure point 34 is pressurized with the writing instrument 33, the potential at that point is led out to the conductor film 17 by the pressure sensitive rubber 18, and the analog-digital converter 32 is connected to the conductor film 17.
is converted into a digital quantity by A lateral potential corresponding to the pressure point 34 on the input panel is thus obtained. At the next timing, analog switch groups 27, 28, and analog switch 31 are closed, and analog switch group 2 is closed.
5, 26, and the analog switch 30, a vertical potential corresponding to the pressure point 34 on the input panel is obtained in exactly the same way as in the horizontal direction.

Note that the terminal groups 21 to 24 and the terminal groups 21 to 24 are one-to-one.
The analog switch groups 25 to 28 provided in the circuit are symbolically shown as three each in FIG. do not have.

As explained above, in the first embodiment, a DC voltage is applied to the resistive film 19 by switching the vertical and horizontal directions using an analog switch. All coordinates are detected by detection using the membrane 17. Because analog switches are used for switching, the current looping is only a practical problem, and the circuit can be ideally connected and disconnected, which is equivalent to switching the circuit using a mechanical switch. Therefore, the coordinate position accuracy does not deteriorate. Therefore, the coordinate position can be detected with high precision simply by converting the potential detected by the conductive film 17 into a digital quantity by the analog/digital converter 32.

Furthermore, since the circuit does not need to be complicated as in the case where the drive power source is an AC power source, there is an advantage that reliability can be improved.

Furthermore, in terms of use, since the input pen does not require a connection cord, a normal writing instrument can be used, which improves operability, and has the advantage that input can be made while taking notes.

In addition, from a manufacturing perspective, since the resistive film can be formed on the insulating substrate, the same effect can be obtained as the resistive film is essentially eliminated, and in addition, only the conductive film and the insulating film need to be flexible. Furthermore, the wiring between the analog switch and the terminal group on the resistive film can be formed by a printed pattern on the back side of the insulating substrate, which has the advantage that the manufacturing process can be simplified, such as by reducing the number of wiring lines, and the coordinate input device can be provided at a low price.

In the first embodiment, as shown in FIG. 2, a flexible conductive film 17 is provided on the back surface of a flexible insulating film 16, a resistive film 19 is provided on an insulating substrate 20, and a conductive film 17 is provided on the back surface of a flexible insulating film 16. 17 and the resistive film 19, the pressure sensitive rubber 18 is provided between the second
As shown in FIG. 4 as a configuration diagram of this embodiment, a flexible resistive film 35 is provided on the back surface of a flexible insulating film 16, a conductive film 36 is provided on the insulating substrate 20, and the resistive film 35 is Even if the pressure sensitive rubber 18t is provided between the conductive film 36 and the conductor film 36, the same effect can be obtained.

In the case of the second actual example, the difference in effect from the first example lies in the manufacturing aspect. That is, since only the conductor film 36 is formed on the insulating substrate 20, it can be manufactured using general 1J converter manufacturing technology.

This is essentially an insulating substrate having a conductive film 36, and has the same effect as reducing the number of components by one. Further resistance @35
Since it is only necessary to manufacture and assemble on a separate line, if you do not set up a dedicated line for manufacturing the input panel for the coordinate input device, the first This embodiment has the advantage that the coordinate input device can be provided at a lower cost than the embodiment described above.

In both the first embodiment and the second embodiment, the pressure sensitive rubber 18 was provided between the resistive film and the conductive film.

Instead of this pressure-sensitive rubber 18, an appropriate gap configured so that the resistive film and the conductive film are not electrically connected when no pressure is applied may be used, and even if an appropriate gap is used in place of the pressure-sensitive rubber 18, the present invention will still work. It's not a hindrance.

As explained in detail above, using a DC power supply, one resistive film and one conductive film, voltage is applied to the resistive film vertically and horizontally in a time-division manner by connecting and disconnecting an analog switch, and the voltage is applied to the resistive film vertically and horizontally in a time-division manner. Since the electric potential is detected separately in the vertical and horizontal directions, the coordinate position can be detected with high precision.In addition, there is no need for a connection cord to the writing instrument, and you can input data while keeping a notebook. It can also be widely used in fields such as input panels for online character recognition.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional coordinate input device.
FIG. 2 is a configuration diagram of the first embodiment of the present invention. FIG. 3 is a block diagram of the present invention, and FIG. 4 is a configuration diagram of a second embodiment of the present invention. 1... Resistance film closely adhered on an insulating substrate, 2... AC power source, 3-6... diode group, 7-10... terminal group. 11...Pen, 12.13...Diode,
14.15...Terminal. 16... Insulating film, 17... Conductor film, 18... Pressure sensitive rubber, 19... Resistive film, 20... Insulating substrate, 21-
24... Terminal group, 25-28... Analog switch group, 29... DC power supply, 30° 31... Analog switch, 32... Analog-digital converter,
33...Writing A, 34...One addition Ff, 35
...Resistance film, 36...Conductor film. Patent applicant Oki Electric Industry Co., Ltd. Patent application agent Megumi Yamamoto - Figure 4

Claims (1)

[Scope of Claims] In a coordinate input device that includes an input panel and a pressurizing body that selectively pressurizes the input panel, and outputs coordinate information of a pressurized position as an electric signal, the input panel is a A laminated structure consisting of a rectangular resistive film having a plurality of terminals on the four sides of the grid, a conductive film, and a pressure-sensitive rubber or gap formed between the conductive film and the resistive film. It has an insulating substrate and an insulating film provided on the front and back sides of the laminated structure, and a plurality of analog switches provided corresponding to each terminal of the resistive film. A coordinate input device characterized in that a voltage is applied to a resistive film through a horizontal terminal and an analog switch, and the potential of the resistive film at a position pressurized by a pressurizing body is detected via a conductive film.