Tablet type coordinate input apparatus using elastic wave
First Claim
1. A tablet type coordinate input apparatus using an elastic wave, comprising:
- medium means for propagating an elastic wave;
elastic wave detecting means disposed on at least part of said medium means;
elastic wave input means including elastic wave generating means for generating an elastic wave and for radiating the generating the generated elastic wave toward any desired position on the surface of said medium means; and
means for receiving electrical signals indicative of a longitudinal elastic wave component of said radiated elastic wave detected by said detecting means, thereby providing coordinate information of the input position of said input means.
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Abstract
A tablet type coordinate input apparatus comprises a flat medium for propagating a longitudinal elastic wave, longitudinal elastic wave detecting elements disposed on part of the end-adjacent side surfaces or of the front surface of the flat medium, a longitudinal elastic wave input member having an end portion terminating in a sharp-pointed end and brought into pressure engagement at that end with any desired position on the surface of the flat medium to radiate the longitudinal elastic wave from that end, an amplifier circuit amplifying electrical signals indicative of the elastic wave detected by the detecting elements, a comparator circuit comparing the signals amplified by the amplifier circuit with a predetermined threshold voltage thereby generating delay pulse signals corresponding to the propagation times of the longitudinal elastic wave, a counter circuit counting the lengths of time elapsed from the time of radiation of the longitudinal elastic wave toward the flat medium as a result of pressure engagement of the input member therewith to the time of generation of the delay pulse signals, and a computing circuit computing the coordinates on the basis of the time signals applied from the counter circuit.
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Citations
20 Claims
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1. A tablet type coordinate input apparatus using an elastic wave, comprising:
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medium means for propagating an elastic wave; elastic wave detecting means disposed on at least part of said medium means; elastic wave input means including elastic wave generating means for generating an elastic wave and for radiating the generating the generated elastic wave toward any desired position on the surface of said medium means; and means for receiving electrical signals indicative of a longitudinal elastic wave component of said radiated elastic wave detected by said detecting means, thereby providing coordinate information of the input position of said input means.
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2. A tablet type coordinate input apparatus, comprising:
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flat medium means for propagating an elastic wave; detecting means disposed on part of one of the end-adjacent surfaces and the front surface of said medium means for detecting a leading wave of a longitudinal elastic wave component of said elastic wave; elastic wave input means including elastic wave generating means for generating an elastic wave, said elastic wave input means having an end portion terminating in a sharp-pointed end and brought into pressure engagement at said end with any desired position on the front surface of said medium means to radiate the generated elastic wave from said end; and means for receiving electrical signals indicative of the leading wave of the longitudinal elastic wave detected by said detecting means as a result of radiation of said elastic wave, thereby providing information of the identified engaging position of said input means. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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- 18. A tablet type coordinate input apparatus comprising input means having a built-in ultrasonic wave transmitting element generating an ultrasonic wave by being excited by an electrical signal and having a sharp-pointed end for radiating the ultrasonic wave, writable means for propagating the ultrasonic wave radiated from said input means, detecting means inlcuding wave receiving elements disposed at or adjacent to the corners of said writable means for converting the propagating ultrasonic wave into electrical signals, and signal processing means for identifying the position of said input means by processing the output signals of said detecting means, said writable means being composed of at least two laminar media including a laminar propagation medium propagating the ultrasonic wave and an overlying laminar input medium having a longitudinal wave propagation velocity lower than that of said laminar propagation medium, said wave receiving elements being mounted to said laminar propagation medium.
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20. A tablet type coordinate input apparatus comprising input means having a built-in ultrasonic wave transmitting element generating an ultrasonic wave by being excited by an electrical signal and having a sharp-pointed end for radiating the ultrasonic wave, writable means for propagating the ultrasonic wave radiated from said input means, detecting means including wave receiving elements disposed at or adjacent to the corners of said writable means for converting the propagating ultrasonic wave into electrical signals, signal processing means for identifying the position of said input means by processing the output signals of said detecting means, and display means for displaying the identified position, said input means being provided at its sharp-pointed end with a contact-purpose small piece formed of a medium whose longitudinal wave propagation velocity is lower than that of said writable means.
Specification