Sensing system

• US 8,135,561 B2
• Filed: 12/08/2009
• Issued: 03/13/2012
• Est. Priority Date: 10/10/2008
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Lin, Cho-Yi, Cheng, Hsin-Chi
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US12/632,808
• Publication Number:
  US 20100090987A1
• Time in Patent Office: 826 Days
• Field of Search: 702/150, 702/151, 702/152, 702/153, 345/173, 345/157, 345/158, 178/18.09
• US Class Current: 702/150
• 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 panel, a reflective element, an image sensor, a processor, a first light guide rod, a second light guide rod and a light source module. The panel has a plane and a first area and a third area located at the plane. The third area in the first area is smaller than or equal to the first area. The first area has four boundaries connected in order. A reflective mirror plane of the reflective element disposed at the first boundary mirrors the first and third areas. The image sensor disposed at the intersection of the third and fourth boundaries is electrically connected to the processor. The first and the second light guide rods are disposed at the second and the third boundaries respectively. The light source module is adapted to emit light passing through the first and the second light guide rods to the image sensor.

Claims

1. A sensing system adapted to sense a pointer and calculate a location of the pointer, comprising:

a panel having a first plane, a first area located at the first plane and a third area located at the first plane, wherein the third area is located within the first area, the first area is quadrangular and has a first boundary, a second boundary, a third boundary and a fourth boundary which are connected in order, and the third area is smaller than or equal to the first area;

a reflective element disposed at the first boundary and located on the first plane, wherein a second plane of the reflective element is substantially perpendicular to the first plane, the second plane is a reflective mirror plane, the second plane mirrors the first area to form a second area, and the second plane mirrors the third area to form a fourth area;

an image sensor disposed at a first corner at which the third boundary and the fourth boundary intersect and located on the first plane, wherein the sensing range of the image sensor covers the third area and the fourth area;

a processor electrically connected to the image sensor;

a first light guide rod disposed at the second boundary and located on the first plane, wherein the first light guide rod has a first light-emitting surface and is mirrored by the reflective element to form a second mirror image;

a second light guide rod disposed at the third boundary and located on the first plane, wherein the second light guide rod has a second light-emitting surface and is mirrored by the reflective element to form a third mirror image, and at least part of the first light guide rod, at least part of the second mirror image and at least part of the third mirror image are located in the sensing range of the image sensor; and

a light source module adapted to emit light entering the first light guide rod and the second light guide rod and being transmitted from the first light-emitting surface and the second light-emitting surface to the image sensor;

when the pointer approaches the third area and the pointer is mirrored by the reflective element to form a first mirror image such that the pointer and the first mirror image are located in the sensing range of the image sensor, the image sensor senses the pointer and the first mirror image and the processor calculates the location of the pointer.

2. The sensing system as claimed in claim 1, wherein the light source module has a first light source disposed at the first corner.

3. The sensing system as claimed in claim 2, wherein the light source module further has a second light source disposed at a second corner at which the first boundary and the second boundary intersect.

4. The sensing system as claimed in claim 1, wherein the light source module has a first light source disposed at a third corner at which the second boundary and the third boundary intersect.

5. The sensing system as claimed in claim 4, wherein the light source module further has a second light source disposed at the first corner.

6. The sensing system as claimed in claim 5, wherein the light source module further has a third light source disposed at a second corner at which the first boundary and the second boundary intersect.

7. The sensing system as claimed in claim 1, wherein the first light-emitting surface is a rough surface and the second light-emitting surface is a rough surface.

8. The sensing system as claimed in claim 1, further comprising a first diffuser and a second diffuser, wherein the first diffuser is disposed on the first light-emitting surface and the second diffuser is disposed on the second light-emitting surface.

9. The sensing system as claimed in claim 1, wherein the first light guide rod comprises a first reflective layer disposed at a first bottom surface of the first light guide rod opposite to the first light-emitting surface, and the second light guide rod comprises a second reflective layer disposed at a second bottom surface of the second light guide rod opposite to the second light-emitting surface.

10. A sensing system adapted to sense a pointer and calculate a location of the pointer, comprising:

a panel having a first plane, a first area located at the first plane and a third area located at the first plane, wherein the third area is located within the first area, the first area is quadrangular and has a first boundary, a second boundary, a third boundary and a fourth boundary which are connected in order, and the third area is smaller than or equal to the first area;

a reflective element disposed at the first boundary and located on the first plane, wherein a second plane of the reflective element is substantially perpendicular to the first plane, the second plane is a reflective mirror plane, the second plane mirrors the first area to form a second area, and the second plane mirrors the third area to form a fourth area;

an image sensor disposed at a first corner at which the third boundary and the fourth boundary intersect and located on the first plane, wherein the sensing range of the image sensor covers the third area and the fourth area;

a processor electrically connected to the image sensor;

a first diffuser disposed at the second boundary and located on the first plane, wherein the first diffuser has a first light-emitting surface and is mirrored by the reflective element to form a second mirror image;

a second diffuser disposed at the third boundary and located on the first plane, wherein the second diffuser has a second light-emitting surface and is mirrored by the reflective element to form a third mirror image, and at least part of the first diffuser, at least part of the second mirror image and at least part of the third mirror image are located in the sensing range of the image sensor; and

a light source module adapted to emit light entering the first diffuser and the second diffuser and being transmitted from the first light-emitting surface and the second light-emitting surface to the image sensor;

when the pointer approaches the third area and the pointer is mirrored by the reflective element to form a first mirror image such that the pointer and the first mirror image are located in the sensing range of the image sensor, the image sensor senses the pointer and the first mirror image and the processor calculates the location of the pointer.

11. The sensing system as claimed in claim 10, wherein the light source module has a plurality of light sources, part of the light sources are disposed at a first bottom surface of the first diffuser opposite to the first light-emitting surface, and another part of the light sources are disposed at a second bottom surface of the second diffuser opposite to the second light-emitting surface.