Device for detecting and inputting a specified position

• US 6,518,959 B1
• Filed: 08/28/2000
• Issued: 02/11/2003
• Est. Priority Date: 09/10/1999
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Ito, Takahiro, Saka, Yasuhiko
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US09/650,156
• Time in Patent Office: 897 Days
• Field of Search: 345/150-153, 345/156, 345/179, 345/175, 345/173, 250/221, 362/31
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

The coordinate-position input device comprises a substantially flat surface for specifying a desired position using a pointing tool. A reflecting member is provided around this surface. A light emitter emits a flux of light of desired thickness over the entire surface towards the reflecting member. The light flux is such that it is thicker near the reflecting member and becomes thinner and thinner as it goes away from the reflecting member. That is, the light flux diverges as it approaches the reflecting member.

Claims

1. A coordinate-position input device based on an optical system which detects a coordinate input position by probe beams, wherein an optical axis of a probe beam is substantially parallel to a coordinate input surface and the probe beam, when propagating away from a source, diverges in a direction perpendicular to said coordinate input surface.

2. A coordinate-position input device comprising:

a light-emitting element which emits a probe beam to detect a coordinate input position; and

a refractive lens which refracts the probe beam emitted by said light-emitting element in a prescribed direction, wherein

said light-emitting element is disposed at a location between said refractive lens and a first focal point of said refractive lens.

3. A coordinate-position input device comprising:

a substantially flat surface configured to specify a desired position using a pointing tool;

a reflecting member provided around said surface configured to reflect any light flux falling on the reflecting member;

a light emitter which emits a flux of light of desired thickness over entire said surface towards said reflecting member, wherein the light flux is thicker near said reflecting member and becomes thinner and thinner as it goes away from said reflecting member;

a light receiver which receives the light reflected from said reflecting member and detects an intensity of the received light; and

a calculating unit which calculates coordinates of a position specified on said surface based on the intensity of light detected by said light receiver.

4. The coordinate-position input device according to claim 3, wherein

said surface is substantially rectangular in shape having four corners and four sides,

one unit comprising said light emitter and said light receiver is provided at two adjacent corners of said surface, and

said reflecting member is provided along all sides of said surface excluding a side which is in between said two corners where said light emitter and said light receiver are provided.

5. The coordinate-position input device according to claim 3, wherein said pointing tool is a rod-shaped member made of material which does not allow light to pass through.

6. The coordinate-position input device according to claim 3, wherein said light emitter comprises,

a light source;

a lens which converges a light emitted from said light source into a light beam such that sides of said light beam diverge with respect to an optic axis of the light coming out of said lens; and

a mirror which reflects the light beam coming out of said lens as a flux of light over entire said surface.

7. The coordinate-position input device according to claim 3, wherein said light emitter comprises,

a light source;

a lens which converges a light emitted from said light source into a light beam, wherein said light source is located at a position which is nearer to said lens than a focal point of said lens; and

a mirror which reflects the light beam coming out of said lens as the flux of light over entire said surface.

8. A method of detecting coordinates of a specified position comprising:

emitting a flux of light of a desired thickness over a substantially flat surface towards a reflecting member, which flat surface is used to specify a desired position with a pointing tool, wherein the light flux is thicker near said reflecting member and becomes thinner and thinner as it goes away from said reflecting member;

collecting at two places a light flux reflected by said reflecting member and detecting an intensity of the light coming from different directions and detecting two directions in which the intensity of the light is substantially less as compared to other directions; and

calculating coordinates of the specified position based on an intersection point of said two directions in which the intensity of the light is substantially less and a distance between said two places at which the light flux reflected by said reflecting member is collected.

9. The method of detecting coordinates of the specified position according to claim 8, wherein said pointing tool is a rod-shaped member made of material which does not allow, light to pass through.