LIGHT BEAM POSITION ENCODER APPARATUS

• US 3,860,754 A
• Filed: 05/07/1973
• Issued: 01/14/1975
• Est. Priority Date: 05/07/1973
• Status: Expired due to Term

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: Frederick A. Ebeling, James H. Parry, Roger L. Johnson
• Inventors: Johnson, Roger L., Ebeling, Frederick A., Parry, James H.
• Primary Examiner(s): Robinson, Thomas A.
• Application Number:
  US05/358,020
• Time in Patent Office: 617 Days
• Field of Search: 340/365P,365S,365E,166R 250/553,271,221,338,349,578 178/18,19,17D
• US Class Current: 178/18.09
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An improved sequentially scanned crossed light beam position encoder including means for detecting and transmitting the address of interrupted light beams, means for electrically detecting the subsequent status of an initially detected interrupted beam and means for inhibiting subsequent transfer of the address of the initially detected interrupted beam in the event the subsequent beam status at the address has not changed. The improvement includes means for continuously sequentially activating pairs of non-visible radiation sources and detectors to continuously scan the surface of a display device with respective crossing beams, and means responsive to the initial detection of an interrupted beam at an associated address and responsive to the subsequent absence of beam interruption at the same address on a subsequent scan to reset the system and prepare it for further detection of new beam interruptions.

Claims

1. In a communication system including a display device, a crossed light beam position encoder for said display device having means for detecting and transmitting the address of interrupted light beams, the improvement comprising:

a plurality of respectively paired light beam sources and detectors;

means for sequentially activating said respective pairs of sources and detectors to scan said display device with respective crossed light beams between said sequentially activated paired sources and detectors;

means for electrically detecting the subsequent status of an initially detected interrupted beam at an associated address; and

means for inhibiting subsequent transfer of the address of said initially detected interrupted beam in the event the subsequent status at said address has not changed.

2. In a position address encoder for display devices, including a plurality of paired non-visible radiation sources and detectors along respective sides of the display device, means for sequentially activating pairs of said sources and detectors to scan the surface of the display device with respective crossing beams between said sequentially activated paired sources and detectors, and address means for responding to an interruption of said crossing beams to provide the address of the position of said interruption, the improvement comprising:

means for continuously sequentially activating pairs of said sources and detectors to continuously scan the surface of said display device with said respective crossing beams;

storage means for storing the address of the position corresponding to the detection of an interrupted beam; and

means coupled to said storage means, including means responsive to the initial detection of an interrupted beam at an associated address and to the subsequent absence of said interrupted beam at said address on a subsequent scan to reset said storage means.

3. An x-y position address encoder for display devices comprising:

a plurality of paired x non-visible light sources and detectors arranged to provide non-visible light beams along the x coordinate direction adjacent the surface of said display device;

a plurality of paired y non-visible light sources and detectors arranged to provide non-visible light beams along the y coordinate direction adjacent the surface of said display device;

sequential timing control means selectively coupled to said plurality of x and y non-visible light sources and detectors for sequentially activating corresponding pairs of x sources and detectors, while sequentially activating corresponding pairs of y sources and detectors;

said x and y sources when sequentially activated providing intersecting non-visible light beams sequentially scanning the surface of said display device;

said sequential timing control means including an x and y address counter, including means for denoting the x and y address of the particular pairs of x and y sources and detectors when sequentially activated;

means coupled to said x and y address counter and including means responsive to an interruption of said intersecting non-visible light beams for identifying the corresponding x and y position addresses;

storage means for storing said identified x and y position addresses corresponding to an interruption of said intersecting non-visible light beams; and

means coupled to said storage means, including reset means responsive to the initial detection of an interrupted beam at an associated address and to the subsequent absence of said interrupted beam at said address on a subsequent scan to reset said storage means.

4. An x-y position encoder for display devices according to claim 3, wherein said reset means includes means coupled to said storage means and to saiD detectors for comparing an initial detected and stored interrupted beam status at one address with the detected status on subsequent scans of said address.

5. An x-y position encoder for display devices according to claim 3, wherein said reset means includes;

comparator means having one input coupled to said storage means and another input coupled to said counter for comparing the address of a detected interrupted beam with the sequential addresses from said counter and providing an output signal when said addresses are the same.

6. An x-y position encoder for display devices according to claim 5, wherein said reset means further includes X and Y And gates having inputs coupled respectively to said comparator means and to said X and Y detectors;

said And gates providing a reset signal to reset said storage means when said comparator means output signal and a detected beam signal from said detectors are present at said And gate.

7. In a communication system including a display device, a light beam position encoder for said display device having means for detecting and transmitting the address of interrupted light beams, the improvement comprising:

a plurality of respectively paired light beam sources and detectors;

means for sequentially activating said respective pairs of sources and detectors to scan said display device with respective crossed light beams between said sequentially activated paired sources and detectors;

means for electrically detecting the subsequent status of an initially detected interrupted beam at an associated address; and

means for inhibiting subsequent transfer of the address of said initially detected interrupted beam in the event the subsequent status at said address has not changed.

8. In a light beam position address encoder for display devices, including a plurality of paired non-visible radiation sources and detectors along at least one side of the display device, means for sequentially activating pairs of said sources and detectors to scan the surface of the display device with a light beam between said sequentially activated paired sources and detectors, and address means for responding to an interruption of said light beam to provide the address of the position of said interruption, the improvement comprising:

means for continuously sequentially activating pairs of said sources and detectors to continuously scan the surface of said display device with said light beam;

storage means for storing the address of the position corresponding to the detection of an interrupted beam; and

means coupled to said storage means, including means responsive to the initial detection of an interrupted beam at an associated address and to the subsequent absence of said interrupted beam at said address on a subsequent scan to reset said storage means.

9. In light beam position encoder apparatus having means for detecting and transmitting the address of interrupted light beams, the improvement comprising:

a plurality of respectively paired light beam sources and detectors;

means for sequentially activating said respective pairs of sources and detectors to provide respective crossed light beams between said activated paired sources and detectors;

means for electrically detecting the subsequent status of an initially detected interrupted beam at an associated address; and

means for inhibiting subsequent transfer of the address of said initially detected interrupted beam in the event the subsequent status at said address has not changed.