Photoelectric touch panel having parallel light emitting and detecting arrays separated by a light shield

• US 4,837,430 A
• Filed: 11/30/1987
• Issued: 06/06/1989
• Est. Priority Date: 02/15/1985
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Hasegawa, Kazuo
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): Allen, Stephone B.
• Application Number:
  US07/125,736
• Time in Patent Office: 554 Days
• Field of Search: 250/221, 250/222.1, 340/555-557, 340/365 P
• US Class Current: 250/221
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A photoelectric touch panel has light emitting and light sensing elements mounted on the same circuit board located at one side of the panel and a reflector is placed on an opposing side of the panel thus eliminating the need for a second circuit board at the opposing side.

Claims

1. A photoelectric touch panel comprising:

a rectangular frame defining a planar area for a matrix of light beams which is disposed in front of an associated display screen;

two light detection assemblies perpendicular to each other, each assembly being disposed in parallel with the matrix plane on a respective one of two adjcent sides of said rectangular frame, each assembly consisting of a row of light emitting elements in parallel with a row of light detecting elements, both rows being aligned in parallel with said matrix plane with each of the light emitting elements being positioned spaced apart in a direction perpendicular to said matrix plane from a corresponding one of the light detecting elements, and a light shielding plate arranged upright and extending longitudinally between the two rows of light emitting and light detecting elements, wherein the row of light emitting elements is disposed between the light shielding plate and the display screen; and

two light reflecting members perpendicular to each other, each member being disposed in parallel with the matrix plane on a respective one of the other two adjacent sides of said rectangular frame facing opposite a respective one of the two light detection assemblies, each member consisting of a single planar reflecting plate for reflecting and returning light emitted by each of said light emitting elements of the light detection assembly across said matrix plane to the corresponding ones of said light detecting elements if the respective light beams therefore are not interrupted by an object interposed in said matrix plane, wherein said single planar reflecting plate is oriented perpendicular to said matrix plane and parallel with light to said rows of light emitting and detecting elements.