Optical touch device

• US 8,698,781 B2
• Filed: 10/29/2010
• Issued: 04/15/2014
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Chen, Hui-Hsuan, Liu, Wu-Chieh, Lai, Hung-Ching, Chuang, Chiang-Yuan
• Primary Examiner(s): Beck, Alexander S
• Assistant Examiner(s): BOGALE, AMEN W
• Application Number:
  US12/915,613
• Publication Number:
  US 20110234538A1
• Time in Patent Office: 1,264 Days
• Field of Search: 704231-257, 345/175, 345/18.09, 345/173, 345/176, 178/18.09
• US Class Current: 345/175
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• 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

An optical touch device includes a transparent substrate and at least a light emitting and receiving unit. The transparent substrate has a touch surface, a first light incidence surface and a first light emitting surface. Each light emitting and receiving unit includes a linear light source, a light path adjusting component and a light sensing component. The linear light source is disposed beside the first light incidence surface. The light path adjusting component is disposed between the linear light source and the first light incidence surface and configured for adjusting the incidence angles of the optical signals striking at the first incidence surface so that each of the optical signals enters into the transparent substrate through the first incidence surface with a predetermined angle. The light sensing component is disposed beside the first light emitting surface. The optical touch device has a high light utility efficiency.

Claims

1. An optical touch device, comprising:

a transparent substrate comprising a touch surface and a plurality of side surfaces adjacent to the touch surface, at least one of the side surfaces being a first light incidence surface, and at least one of the side surfaces being a first light emitting surface opposite to the first light incidence surface;

at least a light emitting and receiving unit, and each light emitting and receiving unit comprising;

a linear light source disposed beside the first light incidence surface of the transparent substrate and configured for providing a plurality of optical signals into the transparent substrate;

a light path adjusting component disposed between the linear light source and the first light incidence surface and configured for adjusting incidence angles of the optical signals striking at the first incidence surface so that each of the optical signals enters into the transparent substrate through the first incidence surface with a predetermined angle, wherein the light path adjusting component has a bottom surface, a fourth light incidence surface and a fourth light emitting surface opposite to the fourth light incidence surface, the bottom surface is connected between the fourth light emitting surface and the fourth light incidence surface, the fourth light emitting surface is a plane surface and has two opposite edges respectively connected to the bottom surface and the fourth light incident surface, the fourth light incidence surface is a convex curved surface facing to the linear light source, and the fourth light emitting surface is an inclined surface with respective to the bottom surface; and

a light sensing component disposed beside the first light emitting surface, the light sensing component and the linear light source being respectively disposed at two opposite sides of the transparent substrate, and the light sensing component being configured for sensing the optical signals from the linear light source.

2. The optical touch device as claimed in claim 1, wherein the linear light source comprises:

a light guide plate having a second light incidence surface and a second light emitting surface adjacent to the second light incidence surface, and the second light emitting surface facing to the light path adjusting component;

a light emitting component disposed beside the second light incidence surface; and

a shell configured for receiving the light guide plate and the light emitting component.

3. The optical touch device as claimed in claim 2, wherein the light emitting component comprises an infrared light emitting component.

4. The optical touch device as claimed in claim 1, wherein each light emitting and receiving unit further comprises a light concentrating component disposed between the light sensing component and the first light emitting surface and configured for receiving the optical signals emitting from the first light emitting surface, and a light emitting structure is disposed on a surface of the light concentrating component far away from the transparent substrate to transmit the optical signals to the light sensing component through the light emitting structure.

5. The optical touch device as claimed in claim 4, wherein the light emitting structure comprises a grating structure or a matte surface structure.

6. The optical touch device as claimed in claim 4, wherein each light emitting and receiving unit further comprises a lens set disposed between the light sensing component and the light concentrating component and configured for concentrating the optical signals to the light sensing component.

7. The optical touch device as claimed in claim 4, wherein each light emitting and receiving unit further comprises a reflecting member, the reflecting member is disposed between the light sensing component and the light concentrating component and configured for reflecting the optical signals to the light sensing component.

8. The optical touch device as claimed in claim 7, wherein the reflecting member of each light receiving and emitting unit comprises a prism, and the prism has a third light incidence surface facing to the light concentrating component, a third light emitting surface facing to the light sensing component and a reflecting surface connecting between the third light incidence surface and the third light emitting surface.

9. The optical touch device as claimed in claim 7, wherein each light emitting and receiving unit further comprises a refracting member disposed between the reflecting member and the light concentrating component and configured for refracting the optical signals to the reflecting member.

10. The optical touch device as claimed in claim 1, further comprising two reflecting layers respectively formed on the touch surface and a surface opposite to the touch surface, wherein the reflecting layers are configured for reflecting infrared optical signals.

11. The optical touch device as claimed in claim 1, wherein the transparent substrate is a substrate of a display panel.

12. The optical touch device as claimed in claim 1, wherein the first light incidence surface is an inclined surface.

13. The optical touch device as claimed in claim 1, wherein the light sensing component has a sensing region, the optical signals provided by the linear light source are totally reflected in the transparent substrate, when a touch member touches the touch surface, a portion of the optical signals is not totally reflected due to the touch member so that a portion of the sensing region of the light sensing component do not sense the optical signals.

14. The optical touch device as claimed in claim 13, further comprising a processing unit electrically connected to the light sensing component, wherein the processing unit is configured for judging a location of the touch member according to a location of the portion of the sensing region that do not sensing the optical signals.