Optical touch module capable of increasing light emitting angle of light emitting unit

• US 8,462,138 B2
• Filed: 03/16/2011
• Issued: 06/11/2013
• Est. Priority Date: 12/02/2010
• Status: Active Grant

• Current Assignee: Wistron Corporation
• Original Assignee: Wistron Corporation
• Inventors: Huang, Po-Liang, Liu, Chia-Jui
• Primary Examiner(s): OSORIO, RICARDO
• Application Number:
  US13/048,888
• Publication Number:
  US 20120139875A1
• Time in Patent Office: 818 Days
• Field of Search: 345/156, 345/173, 345/175, 345/104
• 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 module includes a screen and at least one optical positioning device disposed on the screen. The optical positioning device includes a case, at least one light emitting unit, a circuit board, a transparent diffusing part and an image capturing unit. The light emitting unit is disposed on case for emitting invisible light. The circuit board is electrically connected to the light emitting unit for controlling the light emitting unit. The transparent diffusing part is disposed at a light emitting side of the light emitting unit. A bar structure is formed on a light entrance surface of the transparent diffusing part for scattering the invisible light to be distributed over a touch surface of the screen. The image capturing unit is disposed on the case to capture an optical image for a touch object on the touch surface when the touch object is illuminated by the invisible light.

Claims

1. An optical touch module capable of increasing a light emitting angle of a light emitting unit, the optical touch module comprising:

a screen having a touch surface; and

at least one optical positioning device disposed on the screen, the optical positioning device comprising;

a case;

at least one light emitting unit disposed on the case for emitting invisible light;

a circuit board electrically connected to the light emitting unit for controlling the light emitting unit;

a transparent diffusing part disposed at a light emitting side of the light emitting unit, a bar structure being formed on a light entrance surface of the transparent diffusing part for scattering the invisible light to be distributed over the touch surface; and

an image capturing unit disposed on the case for capturing an optical image of a touch object on the touch surface when the touch object is illuminated by the invisible light.

2. The optical touch module of claim 1, wherein the light emitting unit is a near-infrared lamp LED.

3. The optical touch module of claim 2, wherein a diameter of the near-infrared lamp LED is substantially equal to 5 mm.

4. The optical touch module of claim 1, wherein a half-light-intensity of the light emitting unit is substantially equal to 40 degrees.

5. The optical touch module of claim 1, wherein the transparent diffusing part is made of transparent acrylic material.

6. The optical touch module of claim 1, wherein the bar structure is a continuous tooth-shaped bar structure.

7. The optical touch module of claim 6, wherein a vertex angle of the continuous tooth-shaped bar structure is substantially equal to 30 degrees.

8. The optical touch module of claim 1, wherein the bar structure is a discontinuous tooth-shaped bar structure.

9. The optical touch module of claim 8, wherein a vertex angle of the discontinuous tooth-shaped bar structure is substantially equal to 30 degrees.

10. The optical touch module of claim 8, wherein a distance between two bars on the discontinuous tooth-shaped bar structure is substantially equal to 1.4 mm.

11. The optical touch module of claim 1, wherein the bar structure is a continuous arc-shaped bar structure.

12. The optical touch module of claim 11, wherein a radius of the continuous arc-shaped bar structure is substantially equal to 0.7 mm.

13. The optical touch module of claim 1, wherein the bar structure is a discontinuous arc-shaped bar structure.

14. The optical touch module of claim 13, wherein a radius of the discontinuous arc-shaped bar structure is substantially equal to 0.7 mm.

15. The optical touch module of claim 13, wherein a distance between two bars of the discontinuous arc-shaped bar structure is substantially equal to 1.2 mm.