Sensing System and Locating Method thereof

• US 20100141963A1
• Filed: 02/10/2010
• Published: 06/10/2010
• Est. Priority Date: 10/10/2008
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: HSU, Teng-Wei, Cheng, Hsin-Chi
• Granted Patent: US 8,305,363 B2
• Time in Patent Office: Days
• US Class Current: 356/614
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421

Abstract

A sensing system includes a frame having a first boundary, a second boundary, a third boundary and a fourth boundary and defining a sensing area therein, a light source module for providing light to the sensing area, a first image sensor, a second image sensor, a third image sensor and a mirror component. The first image sensor is disposed between two neighboring ends of the first and second boundaries. The second image sensor is disposed between two neighboring ends of the second and third boundaries. The third image sensor is disposed between two neighboring ends of the first and fourth boundaries. The mirror component is disposed at the fourth boundary. A locating method of the sensing system can determine a location of a pointer accurately and avoid a problem of a blind zone.

Claims

1. A sensing system, comprising:

a frame comprising a first boundary, a second boundary, a third boundary and a fourth boundary, the first boundary facing to the third boundary, the second boundary facing to the fourth boundary, the frame defining a sensing area therein;

a light source module configured for providing light to the sensing area;

a first image sensor disposed between two neighboring ends of the first boundary and the second boundary, a sensing range of the first image sensor covering the third boundary and the fourth boundary;

a second image sensor disposed between two neighboring ends of the second boundary and the third boundary, a sensing range of the second image sensor covering the first boundary and the fourth boundary;

a third image sensor disposed between two neighboring ends of the first boundary and the fourth boundary, a sensing range of the third image sensor covering the second boundary and the third boundary; and

a mirror component disposed at the fourth boundary, wherein the mirror component is configured for forming a mirror image of a pointer in the sensing area, and the first image sensor and the second image sensor are configured for sensing optical information of the pointer and the mirror image.

2. The sensing system as claimed in claim 1, wherein the light source module comprises:

a first light emitting component disposed between two neighboring ends of the first boundary and the second boundary;

a second light emitting component disposed between two neighboring ends of the second boundary and the third boundary; and

a third light emitting component disposed between two neighboring ends of the first boundary and the fourth boundary.

3. The sensing system as claimed in claim 2, further comprising:

a fist light guiding component disposed at the first boundary;

a second light guiding component disposed at the second boundary; and

a third light guiding component disposed at the third boundary.

4. The sensing system as claimed in claim 3, wherein each of the first light guiding component, the second light guiding component and the third light guiding component is a light reflecting bar, the first light emitting component, the second light emitting component and the third light emitting component emit light towards the sensing area, and the first light guiding component, the second light guiding component and the third light guiding component reflect the light arriving thereat to the sensing area.

5. The sensing system as claimed in claim 3, wherein each of the first light guiding component, the second light guiding component and the third light guiding component is a light guide bar, and has a light emitting surface facing to the sensing area and a light incidence surface adjacent to the light emitting surface, the first light emitting component, the second light emitting component and the third light emitting component emit light to the light incidence surfaces of the first light guiding component, the second light guiding component and the third light guiding component respectively, and the light emits from the light emitting surfaces of first light guiding component, the second light guiding component and the third light guiding component to the sensing area.

6. The sensing system as claimed in claim 2, wherein each of the first light emitting component, the second light emitting component and the third light emitting component is a light emitting diode.

7. The sensing system as claimed in claim 1, wherein each of the first image sensor, the second image sensor and the third image sensor comprises a sensing unit and a processor electrically connected to the sensing unit.

8. The sensing system as claimed in claim 1, wherein further comprising a plate for disposing the frame, the light source module, the first image sensor, the second image sensor and the third image sensor thereon.

9. A locating method suitable for being applied to the sensing system claimed in claim 1, comprising:

using the mirror component to mirror a pointer in the sensing area to form a mirror image of the pointer;

sensing dark points caused the pointer by the first image sensor, the second image sensor and the third image sensor respectively to obtain a first optical information, sensing dark points of the mirror image by the first image sensor and the second image sensor respectively to obtain a second optical information; and

determining a location of the pointer in the sensing area according to the first optical information and the second optical information.