JPS61169931A - Input device - Google Patents

Abstract

PURPOSE:To detect highly accurately the coordinate data of a keying position by retrieving a storage means on the basis of the counting values of a clock counter group executing counting operation by detecting signals outputted from a pickup group. CONSTITUTION:Oscillation waves generated by keying a substrate 1 are independently detected by plural pickup groups 3-5 or 3'-5'. Simultaneously, a pickup group having the highest detecting signal level is selected out of the pickup groups 3-5 or 3'-5' by a level comparing means 15. A CPU8 inputs the counting value of a clock counter group in a control means 6 which corresponds to the pickup group selected by the control means 6 on the basis of a selecting signal outputted from the means 15, retrieves the storage means on the basis of the counting value, so that the X-Y coordinate data indicating the keying positions can be read out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an input device that detects coordinate positions by detecting vibration waves generated and propagated on a board by a plurality of pickups when a key is pressed.

(Technical background of the invention and its problems) Conventionally, coordinates have been detected using a resistive film method, a capacitive method, or an LED.
This was done by various methods. That is, the resistive film method is a method in which x and y coordinates are detected by overlapping sheets in which conductive materials are provided in a grid pattern in the vertical and horizontal directions, and pressing a desired position to extract a voltage corresponding to the coordinates. Further, the capacitive method is a method in which the capacitance value is changed by pressing the electrode portion, and the X and Y coordinates are detected from this capacitance change. Furthermore, the LED method is a method for detecting x and Y coordinates by blocking light between a light emitting element and a light receiving element with a finger or the like.

However, since the resistive film method uses a voltage division method, it is necessary to make the resistance value of the conductive material uniform, resulting in poor yields and the transparency of the resistive film being as low as 62-63%. You can see the image by pasting it on the surface.
There is a drawback that it becomes. In addition, in the capacitive method, the electrode part must be a certain size in order to obtain changes in capacitance, so the input range is limited and the resolution is low. It has the disadvantage that it is easily affected and malfunctions, and that the surface film is easily damaged because it is a film. Furthermore, the LED method has the disadvantage that it often malfunctions because the light may be blocked by dust or the like.

Therefore, the present applicant first generates a vibration wave at an arbitrary position on the board by pressing a key, and detects this vibration wave with a propagation time difference at a plurality of peaks and cup sections provided on the board. In addition, we have proposed an input device that allows a clock counter to count pulses from a pulse generator in accordance with the propagation time difference, thereby accurately detecting the X and Y coordinates corresponding to the keystroke position at low cost. (November 1982)
(See patent application filed on May 20th).

(Object of the Invention) A further object of the present invention is to
, Y coordinates can be detected.

(Summary of the Invention) The present invention independently detects vibration waves generated by keystrokes on a board using a plurality of pickup groups, selects the pickup group with the highest detection signal level by a level comparison means, and selects the pickup group with the highest detection signal level by a level comparison means. It is characterized by taking in the count value of the clock counter group corresponding to the pickup group selected by the control means based on the selection signal from the control means, and searching the storage means based on the count value to read coordinate data indicating the keystroke position. do.

(Embodiments of the Invention) Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the input device according to the present invention has a substrate l.
Equipped with A keystroke range LA is formed on the substrate 1 as an input range for a keystroke pen (not shown). A first pickup group 2 (see FIG. 2) consisting of pickups 3 to 5 and a second pickup group 2' consisting of pickups 3' to 5' are mounted on the substrate l.

These pickups 3 to 5 and 3' to 5' are composed of piezoelectric elements made of, for example, 25 mm' PZT (lead zirconium titanate), and detect the vibration waves generated on the substrate l when keys are pressed with a key pen. do. Each Big Ar,
3 to 5 and 3' to 5' are connected to a controller 6. As shown in FIG. 2, this controller 6 includes a reset start generation circuit 9 to which detection signals from each pickup of the first pickup group 2 are input, and a second
A reset start generation circuit 9' to which the detection signal from each pickup of the pickup group 2' is manually input, and clock counters 10 to 12 whose reset inputs are connected to the output side of each reset start generation circuit 9 and 9'. 10' to 12'. Clock counters 10 to 12 constitute a first clock counter group 13 and are connected to the output sides of pickups 3 to 5, respectively.

Further, the clock counters 10' to 12' constitute a second clock counter group 13', and are connected to the output sides of the pickups 3' to 5', respectively. These clock counters lO to 12 and lO' to 12
A pulse oscillator 14 is connected to ', and the pulse oscillator 14 inputs pulses to be counted at a predetermined frequency.

A CPU 8 is connected to the output side of each clock counter,
A ROM 7 is connected to the CPU 8 via a memory bus. The ROM 7 has a coordinate data section in which keystroke positions on the board 1 are stored as X-Y coordinate data. The ROM 7 also includes a first clock counter group 13.
, set the count value of each clock counter to the reference value "O"
In the first coordinate conversion table in which the count values of the other two clock counters correspond to the above X-Y coordinate data, and in the second clock counter group 13', the count values of each clock counter are used as a reference. A second coordinate conversion table is stored in which the count values of the other two clock counters are made to correspond to the XY coordinate data when the value is set to "0". The output side of the level comparator 15 is connected to the control terminal of the CPU 8, and the pickups 4 and 5 and 4' and 5' are connected to the input side of the level comparator 15. This level comparator 15 determines the output level when the respective detection signal levels output from the pickups 4 and 5 are added, and the output level when the respective detection signal levels output from the pickups 4' and 5' are added. Compare.

If the output level of pickups 4 and 5 is high, CPU8
Outputs the selection signal to.

Next, the operation of the input device according to the present invention will be explained together with the control operation of the CPU 8.

When an arbitrary point within the keystroke range IA, for example, point A, is tapped with a keystroke pen, a vibration wave is generated on the substrate 1, and this vibration wave propagates through the substrate 1. Then, this vibration wave first begins with A
Since the pickups 3' and 3 located closest to the point are reached first, the respective detection signals from these pickups 3' and 3 trigger the respective reset start generation circuits 9 and 9' of the controller 6, and each reset From the start generation circuits 9 and 9' to the first clock counter group 13
A reset signal is output to the clock counters 10 to 12 of the second clock counter group 13' and the clock counters 10' to 12' of the second clock counter group 13'. Therefore, each clock counter 10 to 12 and 10' to 12' starts operating,
The pulses from the pulse oscillator 14 are counted. The detection signals of the pickups 3 and 3', which the vibration waves reach first, are input to the respective reset start generation circuits 9 and 9', and are also input to the clock counters 10 and 10' as counting stop signals. Therefore, the count values of the clock counters 10 and 10' connected to the pickups 3 and 3' where the vibration waves first arrived are held at rOJ, and based on this value, the other clock counters 11, 12 and 11', 12' counts the pulses from the pulse oscillator 14 as described above.

Next, when the vibration wave generated by the key pen reaches the pickups 5 and 5', each detection signal of these pickups 5 and 5' is inputted to the clock counters 12 and 12' as a counting stop signal. 12 and 12' stop the counting operation. Furthermore, when the vibration waves finally reach the pickups 4 and 4', the detection signals of these pickups 4 and 4' are input to the clock counters 11 and 11' as counting stop signals, so the clock counters 11 and 11' Stop counting operation.

On the other hand, the detection signals of the pickups 4 and 5 and the detection signals of the pickups 4' and 5' are input to the level comparator 15, but the distance between the above point A and one of the pickups 4 and 5 is ' and 5', the output level from one of the pickups 4 and 5 becomes large. Therefore, from the level comparator 15, CP
A selection signal is output to U8. When this selection signal is input, the CPU 8 determines that the output levels from the clock counters 4 and 5 of the first clock counter group 13 are large, as shown in FIG. The clock counter that should be used as a reference, in the above example, reads the address of the clock counter 10.
The CPU 8 reads the counted value of the clock counter that detected the vibration wave second, which is the clock counter 12 in the above example, and compares this counted value with the corresponding value in the first coordinate conversion table based on the above address. , determine whether there are similar values. If there are similar values, the clock counter that last detected the vibration wave, in the above example, clock counter 1.
A count value of 1 is read in, and this count value is compared with the corresponding value in the coordinate conversion table in the same manner as described above, and it is determined whether there is a similar value. If a similar value exists, the coordinate data section of the ROM 7 is searched based on the address of the reference clock counter 10 and the hundred count value, and the X-Y coordinates corresponding to the point A are stored. The address information is read out and this address information is transferred to the CPU on the host side.

On the other hand, when the key is pressed at point A' in FIG. 5' becomes thicker, the level comparator 15 does not output a selection signal to the CPO2, and when the selection signal is not input, the CPU 8
The CPU 8 determines that the output level from the clock counters 4' and 5' of the clock counter group 13' is large, and reads out the address of the clock counter 10' from the second coordinate conversion table in the ROM 7. The count value of the clock counter 12' that detected the vibration wave and the count value of the clock counter 11' that detected the vibration wave last are read, and each count value is compared with the corresponding value in the second coordinate conversion table. Search the coordinate data section of ROM 7 from the count value and the above address, read out the address where the X-Y coordinates corresponding to the above point A' are stored, and further transfer this address information to the CPU on the host side. .

In this way, the output levels of each pickup group are compared,
When you select the pickup group near the keystroke position on board l,
Since the pickup group outputs the detection signal before the vibration waves are greatly attenuated, it is possible to send a high-level detection signal to the corresponding clock counter group. Therefore, it is possible to search for coordinate data using the count values of the clock counter group with significantly less malfunction, so that coordinate data corresponding to the keystroke position can be obtained accurately.

In the above embodiment, a pair of pickup groups 2.2' is associated with a pair of clock counter groups 13.13', but three or more pickup groups may be associated with three or more clock counter groups. good.

(Effects of the Invention) According to the present invention, the count value of the clock counter group that selects the pick-up group with the highest detection signal level and performs a counting operation based on the detection signal from the pickup group, that is,
By searching the storage means using the count value of the clock counter group, which is extremely unlikely to malfunction, the coordinate data of the keystroke position can be detected with high precision.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an input device according to the present invention, FIG. 2 is a flowchart showing the internal configuration of a controller according to the present invention, and FIG. 3 is an operation flowchart. 1--1----- Board, 2.2"---1--Pickup group, 3 to 5--
, ---Pickup, 3' to 5'-1--//7-------ROM. 8---------CPU, 10 to 12---Clock counter. 10' to 12' --tt 13.13' --m-clock counter group, 15 ---
-----Level comparator. Figure 2

Claims (1)

[Claims] a board on which a key is pressed at an arbitrary position; provided on the board;
at least one pair of pickup groups consisting of a plurality of pickups each detecting a vibration wave generated and propagated on the board by the keystroke with a time difference; and an output from each pickup group provided corresponding to the pickup group. a plurality of clock counter groups, each of which corresponds to a time difference between the detection signals detected by a pulse count value, and a storage means that stores keystroke positions on the board as coordinate data in correspondence with the count values of each of the clock counter groups; Level comparison means for comparing detection signal levels from the plurality of pickup groups and selecting the pickup group with the highest detection signal level; and a clock counter corresponding to the selected pickup group based on the selection signal from the level comparison means. An input device comprising: control means for taking in a count value of a group, searching the storage means and reading out corresponding coordinate data.