Light guide mechanism for guiding a light to an illuminance sensor

• US 7,884,314 B2
• Filed: 12/23/2008
• Issued: 02/08/2011
• Est. Priority Date: 04/03/2008
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Tagawa, Masashi, Hamada, Wataru, Kang, Hui Young, Takemoto, Yuji, Hagii, Toshiharu
• Primary Examiner(s): Sohn; Seung C
• Application Number:
  US12/318,276
• Publication Number:
  US 20090250598A1
• Time in Patent Office: 777 Days
• Field of Search: 250/227.14, 250/208.1, 250/239
• US Class Current: 250/227.14
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0204 Compact construction
• CPC Class Codes: G01J 1/0233 Handheld
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0422 using light concentrators, collectors or condensers

Abstract

A light guide mechanism for an illuminance sensor includes: a lighting window configured to pass through an external light; the illuminance sensor configured to detect an illuminance of the light passed through the lighting window; and a light-blocking part provided between the lighting window and the illuminance sensor and configured to block a light other than the light passed through the lighting window. The light-blocking part has an inner surface inclined with respect to a line perpendicular to a light-receiving surface of the illuminance sensor. A direction of inclination of the inner surface is such that the inner surface faces the light-receiving surface of the illuminance sensor.

Claims

1. A light guide mechanism for an illuminance sensor, comprising:

a lighting window configured to pass through an external light;

the illuminance sensor configured to detect an illuminance of the external light passed through the lighting window; and

a light-blocking part provided between the lighting window and the illuminance sensor and configured to block a light other than the light passed through the lighting window, which travels toward an inner space from outside the light-blocking part, the inner space being formed at least by the light-blocking part,

wherein the light-blocking part has an inner surface inclined with respect to a line perpendicular to a light-receiving surface of the illuminance sensor, and a direction of inclination of the inner surface that faces the light-receiving surface of the illuminance sensor.

2. The light guide mechanism according to claim 1, wherein the inner space includes an empty space having a circular or polygonal cross section, and at least a part of the empty space is inclined with respect to the line perpendicular to the light-receiving surface of the illuminance sensor so that a cross sectional area of the empty space increases toward the illuminance sensor.

3. The light guide mechanism according to claim 1, wherein an inclination angle of the inner surface of the light-blocking part is determined based on an amount of light reflected by the inner surface of the light-blocking part and incident on the illuminance sensor.

4. The light guide mechanism according to claim 1, wherein the light-blocking part is integrally formed with a housing to which the lighting window is provided.

5. The light guide mechanism according to claim 1, wherein a display device is arranged in a vicinity of the illuminance sensor, and a part of the display device forms a part of the light-blocking part.

6. The light guide mechanism according to claim 1, wherein the illuminance sensor is provided inside a device housing, and a part of the device housing forms a part of the light-blocking part.

7. The light guide mechanism according to claim 1, wherein the lighting window is formed of a material, which transmits a light while scattering the light.

8. A mobile phone comprising:

a housing; and

a light guide mechanism provided in the housing,

wherein the light guide mechanism includes,

a lighting window provided in the housing and configured to pass through an external light;

an illuminance sensor provided in the housing and configured to detect an illuminance of the external light passed through the lighting window; and

a light-blocking part provided between the lighting window and the illuminance sensor and configured to block a light other than the light passed through the lighting window, which travels toward an inner space from outside the light-blocking part, the inner space being formed at least by the light-blocking part,

wherein the light-blocking part has an inner surface inclined with respect to a line perpendicular to a light-receiving surface of the illuminance sensor, and a direction of inclination of the inner surface that faces the light-receiving surface of the illuminance sensor.

9. The mobile phone according to claim 8, wherein the inner space includes an empty space having a circular or polygonal cross section, and at least a part of the empty space is inclined with respect to the line perpendicular to the light-receiving surface of the illuminance sensor so that a cross sectional area of the empty space increases toward the illuminance sensor.

10. The mobile phone according to claim 8, wherein an inclination angle of the inner surface of the light-blocking part is determined based on an amount of light reflected by the inner surface of the light-blocking part and incident on the illuminance sensor.

11. The mobile phone according to claim 8, wherein the light-blocking part is integrally formed with the housing to which the lighting window is provided.

12. The mobile phone according to claim 8, wherein a display device is arranged in a vicinity of the illuminance sensor, and a part of the display device forms a part of the light-blocking part.

13. The mobile phone according to claim 8, wherein a part of the housing forms a part of the light-blocking part.

14. The mobile phone according to claim 8, wherein the lighting window is formed of a material, which transmits a light while scattering the light.