JPS62236024A - Coordinate input device - Google Patents

Abstract

PURPOSE:To attain a simple constitution of a coordinate input device and to simplify the calculation of coordinates, by supporting an input part having a panel plate at a single point and obtaining the indicated coordinates from the results of detection of two bending distortion values of the support part as well as the indicated pressing force when a panel plate is indicated with pressure. CONSTITUTION:When a point P (x, y) is indicated with pressure on a panel plate 1 after initialization, the signal proportional to the pressing force is produced at a force detector 4 together with the signals proportional to the bending distortion of a support part 2 produced to the distortion detectors 5a and 5b respectively. These three output signals are amplified by a DC amplifier 60 and then stored successively in a memory 64 in the form of digital signals by a multiplexer 61 and an A/D converter 62 and with the indication of a CPU63. Then the indicated pressing force F And the bending distortion values epsilonx and epsilony are calculated and stored in the memory 64. Then both x and y values are calculated from the data on the force F and values epsilonx and epsilony stored in the memory 64.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a coordinate input device that detects positional coordinates on a panel board that are input using a finger or a pen, and inputs the coordinate values into a computer or the like. It is.

[Conventional technology]

Conventionally, characters for computer information terminal devices, etc.

Digitizers, touch panels, and the like have been widely used as input devices for graphics and the like. These input devices sequentially detect coordinates indicated by a pen or finger on an input surface and input them into a computer or the like.

Furthermore, recently, so-called touch input devices, which are integrated input/output devices that process input by pointing the display surface with a finger or a pen, have been developed that combine a display device and an input device in an integrated manner. Due to its excellent properties, its use is increasing.

Typical methods for such input devices include the electromagnetic induction method, the capacitive coupling method, the method in which a switch matrix is constructed using a conductive film, and the method in which a transparent resistance sheet is used to determine the indicated coordinates based on voltage and current division characteristics. A method to detect the specified coordinates by blocking the scanning light beam, a method to detect the propagation time of surface waves, etc. A method to elastically support the input panel board at multiple points and suppress the input panel board. There is a mechanical method that detects the indicated coordinates by using the component force or displacement of the support part when the object is moved. (For example, shapes and images,
Vol. 3, Not (1982) P. 65 or Nikkei Electronics, No. 1984.72, P. 213) Furthermore, a method has also been proposed in which the indicated coordinates are detected using the inclination of the panel board when an instruction is given as a Ja mechanical method. (See Japanese Patent Application No. 60-287951).

“＼ [Problem to be solved by the invention] However, with the exception of the mechanical detection method,
- Generally, the configuration and processing circuit of the device is complex and expensive, and if it is used by an unspecified number of people on the street, it is difficult to ensure reliability against rough input operations, etc. There were drawbacks such as.

On the other hand, mechanical detection methods are superior in terms of simple structure, ease of selecting elastic springs for support, and ease of ensuring operational reliability when used by an unspecified number of people. ing. In this mechanical detection method, there is a support component force detection method in which the component force of the support part of the indicated pressing force is detected with a force detector or a strain gauge attached to the support, and the coordinate value is obtained, and the other A support displacement detection method is generally used in which coordinate values are determined by detecting the displacement of the support part of the support part using a one-dimensional image sensor, force detector, or conversion of the output of a strain gauge. however.

These detection methods require a minimum of three supports,
Since the number of force detectors, strain gauges, or image sensors required is equal to the number of supporting parts, the configuration of the detectors or the processing circuitry becomes complicated and expensive.

In addition, with the mechanical detection method that uses the tilt of the panel board,
In order to optically detect the inclination of the panel, a separate optical system must be provided and an expensive two-dimensional photodetector element is required.

This invention was made to solve the above problems, and has a simple configuration with a small number of detection elements, and also ensures long-term reliability even when used by an unspecified number of people on the street. The purpose of the present invention is to provide a coordinate input device that allows easy input of coordinates.

[Means for solving problems]

The coordinate input device according to the present invention includes an input section having a panel board for inputting a finger or an instruction, a support section made of an elastic member that supports the input section at one point, and a coordinate input device for inputting an instruction to the panel board. A force detector that detects force, a strain detector that detects the amount of bending strain in two directions of the support part that occurs when an instruction is input, and a force detector that detects the coordinates of the instruction input position when an instruction is input to the panel board. and a coordinate calculation circuit that calculates based on the output of the strain detector.

[Effect]

In this invention, when a point on the panel board of the input section is indicated (pressed) with a finger or a pen, force due to the instruction acts on the input section and the support section, and the support section receives the instruction force and the indicated point. A bending moment determined by is generated. Therefore, each bending moment is detected by a strain detector as a bending strain generated in the support portion using a force detector, and these detection results are used to determine the specified coordinates by a coordinate calculation circuit.

〔Example〕

First, the detection principle of this invention will be explained.

FIG. 5 is a diagram illustrating the detection principle of the present invention, 1
2 is a horizontally placed panel board, and 2 is an elastic support part that fixedly supports the panel board 1 at its center. In addition,
For convenience of explanation, let X be one direction and y be the other direction.
Set orthogonal coordinates x-y as shown in the figure. Now, when a point (x, y) on the panel board 1 is pressed with a force F, a bending moment (Mx) is generated in the support part 2 in the X and y axis directions respectively.
.

My, that is, MX = F fist
・(1)M,=F・y・・・・・・
...(2) comes into play. Therefore, (1), (
From equation 2), the indicated coordinates (x, y) can be determined by measuring the pressing force F and the bending moments Mx, My.

Therefore, if the support part 2 is constructed of a round bar with a diameter d and a length that is intersecting, the support part 2 will have a fixed lower end and a cantilevered circular cross section on which the bending moment (MX, M,) is applied to the upper end. It is considered a burr. In this case, the bending strain eX+'V on the surface of the round bar in the x and y axis directions is as follows, where E is the longitudinal elastic modulus of the round bar.

Length My 64 Therefore, in equations (3) and (4), Mal in equations (1) and (2).

By substituting My and rearranging, the indicated coordinates (x,
y) is the following formula. ' From Equations (5) and (B), the indicated coordinates (x, y) can be obtained by measuring the indicated pressing force F and the bending strains εX, εy of the support part 2. Specifically, the The bending strain @8 is measured by the force detector installed on the support part 2.
, εV can be detected by using two strain detectors provided on the surface of the support portion 2, respectively.

In the above description, a round bar was used as an example of the support part 2, but it is clear that any cross-sectional shape may be used. Furthermore, the mounting angle of the panel board 1, the mounting position of the support part 2 with respect to the panel board 1, and the mounting angle of the two strain detectors are as follows.
It is clear that any selection can be made by correcting the force and strain detection results.

Next, each embodiment of the present invention will be described.

[Embodiment 1] Fig. 1 shows an embodiment of the present invention, in which 1 is a panel plate serving as an input section, 2 is a support part made of an elastic material that fixes and supports the center part of the panel plate 1, and 3 is a base. , 4 is a force detector provided between the lower end of the support part 2 and the base 3, 5a, 5b
is a strain detector provided on the surface of the support part 2, and both are arranged at right angles. Further, 6 is a coordinate calculation circuit to which the outputs of the force detector 4 and the strain detector 5 are connected;
7 is an output terminal from the coordinate calculation circuit 6. In addition, x
, y are orthogonal coordinate axes for explanation, and the panel board 1 is a fully bent flat board made of plastic material or the like. The support part 2 is an elastic member made of metal or plastic and has a circular cross section, and its upper end is fixed to the panel plate 1 and its lower end is fixed to the force detector 4. The force detector 4 is a resistance wire or a semiconductor force transducer, and is fixed to the base 3. The strain detectors 5a and 5b are foil or semiconductor strain gauges, and are attached as 5a and 5b on the negative axis side of the coordinate axis x t V, respectively, as shown in an enlarged view in FIG.

The coordinate calculation circuit 6 has a configuration as shown in FIG.
61 is a multiplexer, 62 is an A/D converter, 163 is a CPU,
64 is a memory, 65A, 65B, and 65C are I10 ports, and 66 is a common bus. The force detector 4 and the strain detectors 5a and 5b are each connected to a multiplexer 61 via a DC amplifier 6o, and the output of the multiplexer 61 is connected to an I10 port 65B via an A/D converter 62, and a memory 64, I10 boat 65A for output,
An I10 port 65C and an I10 port 65B for controlling the multiplexer 61 and the A/D converter 62 are connected to and controlled by a common bus 66 to cp[63.

FIG. 4 is an operation flowchart of the coordinate calculation circuit 6 shown in FIG. The operation of the embodiment of the invention shown in FIG. 1 will be explained with reference to FIG. Note that (1) to (13) indicate each operation step.

First, after performing the initial settings (1), when a point P (x, y) on the panel board 1 is pressed with a finger or a pen, the force detector 4 outputs a signal proportional to the pressing force and a strain signal. A signal proportional to the bending strain occurring in the support portion 2 is generated and output to the detectors 5a and 5b. After each of these three output signals is amplified by the DC amplifier 6o, the CPU 63
According to the instruction, the multiplexer 61 and the A/D converter 62 sequentially store the signals in the memory 64 as digital signals (2) to (7).

Next, the indicated pressing force F and the bending strain amount (8,
ε, is calculated and stored in the memory 64 (8) to (S)
.

＼ Furthermore, the pressing force F and strain amount (×, (()) stored in the memory 64 are
Calculate the X value and y value according to the formula and remember them 10)
.

(11) If necessary, input the signal from the I10 boat 65 to a computer or the like from the output terminal 7 as an output signal (12).

(13).

In this way, by periodically repeating the operation flow shown in FIG. 4, it is possible to process a press input to the panel board 1 at an arbitrary time.

Note that when the designated pressing position is P (0, O), only the output signal of the force detector 4 is obtained, and the strain detectors 5a and 5b are
Although the output signal of the force detector 4 is O, it can be operated without any problem by configuring the device to determine whether or not there is an instruction press based on the level of the output signal of the force detector 4.

[Embodiment 2] FIG. 6 shows another embodiment of the present invention, in which a display device is integrated with a panel board in the input section. That is, 1 is a panel board, 8 is a display device such as a flat display, 9 is a substrate, and the panel 1 and the display device 8 are connected to the substrate 9.
are installed in layers on top. Further, 10 is a control circuit that controls the display device 8, and the other components are the first
This is the same as the embodiment shown in the figure.

In the embodiment shown in FIG. 6, the panel board 1 is transparent, and the upper end of the support part 2 is fixed to the substrate 9.
The configuration and operation are exactly the same as the embodiment shown in FIG.

In addition, in this embodiment, display bag b! Panel 1 on the top of 18
Since the is a laminated structure, instructions can be input directly on the display surface of the display device 8 according to the display or guidance of the display device 8, or conversely, the information can be displayed on the display device 8 at the position where the instructions are input. can do.

[Embodiment 3] FIG. 7 shows still another embodiment of the present invention, in which the force detector 4 used in the embodiment of FIG. 1 was removed and two strain detectors were added to the support part 2. It is the composition. That is, in the embodiment shown in FIG. 7, as shown in FIG. 8 which shows an enlarged cross section of the support part 2, strain detection is performed on the positive axis side of the coordinate axes x and y so as to face the strain detectors 5a and 5b, respectively. This is a configuration in which containers 5c and 5d are added. This results in a configuration in which a pair of strain detectors 5a and 5c are attached in the X direction, and a pair of strain detectors 5b and 5d are also attached in the y direction.

FIG. 9 shows a configuration example of the coordinate calculation circuit 6 of the embodiment shown in FIG. The only difference is that they are connected together, and the other configurations are the same.

Now, consider the operation of the strain detector 5 in this embodiment. One point P(x) on panel board 1.

When y) is pressed, a pressing force F and a bending moment) M (Mx, Mv) are applied to the support portion 2. Now, focusing on the strain detectors 5a and 5c facing each other in the X-axis direction, the bending strains εxa and εyc acting on the respective strain detectors 5a and 5c are as follows, assuming that the elongation strain is positive.

(×a=-ε8F+ε×H・・・・・・・・・(7)ε
xc"-ε×"-ε×-...(8) Here, @×" is the axial (compressive) strain of the support 2 due to the pressing force F, and εXM is the bending moment MX Therefore, if we calculate the sum or difference of equations (7) and (8),

ε×a+εxc= 2ε×[・・・・・・・・・(9
)ε×a−ε×C:2εM −……(10
), the "sum" is the amount of strain that depends only on the commanded pressing force F, as shown in equation (9), and the "difference" is the amount of strain that depends only on the bending moment Mx, as shown in equation (lO). Note that the strain detector 5b in the y-axis direction.

The same applies to 5a.

In this way, by summing the output signals of the strain detectors 5, without using a force detector.

The commanded pressing force F can be determined, and the amount of strain due to the bending moment can be determined by subtraction.

FIG. 10 is an operation flowchart of the coordinate calculation circuit 6 shown in FIG. In the operation flowchart of FIG. 10, step (8) and step (9) are only different from the operation flowchart of FIG. 4, and the other operations are exactly the same. That is, in step (8), by adding (8a) the output signals of the strain detectors 5a and 5c (or 5b and 5d) as shown in equation (8),
Calculate the commanded pressing force F and store it in the memory 64 (8b
). Here, it is clear that the following equation is used to calculate the commanded pressing force F when, for example, a round bar with a diameter d and a length is used as the support portion 2.

Or, in step (9), by subtracting the output signals of the strain detectors 5a and 50 as shown in equation (10), the bending strain ε×base is obtained as (9a), and the strain detector 5b,
The amount of bending strain εVM is obtained by subtracting the output signal of 5d (8b), and from this, ε8=
By substituting ε×V+εV=εyM, the indicated coordinates (x, y) are calculated and stored in the memory 64 (10), (11).

〔Effect of the invention〕

As explained above, this invention supports an input section having a panel plate at one point, and when a specified pressing force is applied to the panel plate, an instruction is obtained from the detection results of the specified pressing force and two amounts of bending strain of the support section. Since the configuration is configured to obtain coordinates, the device configuration and coordinate calculation calculation can be simplified, and the number of detectors can be reduced compared to conventional mechanical methods.

Furthermore, since the device can be configured by combining mechanical elements, it can maintain high reliability over a long period of time even when used by an unspecified number of people, such as on the street.

Furthermore, the designated coordinates can be obtained only by detecting the amount of bending strain in the support portion, which has the advantage of further simplifying the device configuration and making the device more economical.

In addition to being used as a digitizer and a tablet, the present invention is also suitable as a touch panel in which the display device is simplified by making the panel transparent as in the second embodiment.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the first embodiment of this invention, Fig. 2 is an enlarged view of the main part of the embodiment of Fig. 1, and Fig. 3 is a diagram for calculating coordinates of the embodiment of Fig. 1. A circuit configuration diagram showing an example of the circuit, FIG. 4 is an operation flowchart of the coordinate calculation circuit of FIG. 3,
Fig. 5 is a diagram explaining the detection principle of this invention, Fig. 6 is a block diagram of a second embodiment of this invention, Fig. 7 is a block diagram of a third embodiment of this invention, and Fig. 8 is a block diagram of a third embodiment of this invention. FIG. 7 is an enlarged view of the main part of the third embodiment, FIG. 9 is a circuit configuration diagram showing an example of the coordinate calculation circuit of the third embodiment of FIG. 7, and FIG. 10 is an operation flowchart of the coordinate calculation circuit shown in FIG. 9. FIG. In the figure, 1 is a panel board, 2 is a support part, 3 is a base, 4 is a force detector, 5 is a strain detector, 6 is a coordinate calculation circuit, and 7 is an output terminal. Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 ■

Claims (3)

[Claims] (1) An input section having a panel board for inputting instructions with a finger or a pen, a support section made of an elastic member that supports this input at one point, and detecting the force applied to the panel board by inputting instructions. a force detector; a strain detector that detects the amount of bending strain in two directions of the support portion that occurs when an instruction is input; and a strain detector that detects the coordinates of the instruction input position when an instruction is input to the panel board. A coordinate input device comprising a coordinate calculation circuit that calculates coordinates based on output signals from a strain detector. (2) The coordinate input device according to claim (1), wherein the force detector includes a pair of strain detectors provided in at least one direction. (3) The coordinate input device according to claim (1), wherein the input section is equipped with a display device.