Invention Grant
- Patent Title: Ambient light sensor with internal light cancellation
-
Application No.: US14074547Application Date: 2013-11-07
-
Publication No.: US09612152B2Publication Date: 2017-04-04
- Inventor: Erik G. deJong , Jean-Pierre S. Guillou , Koorosh Aflatooni
- Applicant: Apple Inc.
- Applicant Address: US CA Cupertino
- Assignee: Apple Inc.
- Current Assignee: Apple Inc.
- Current Assignee Address: US CA Cupertino
- Agency: Blakely, Sokoloff, Taylor & Zafman LLP
- Main IPC: G01J1/42
- IPC: G01J1/42 ; G01J1/04 ; G01J1/32

Abstract:
An electronic device includes a transparent surface, a light emitting device that emits light through the transparent surface, and a light sensor for receiving ambient light and providing an ambient light value. A retarder and a linear polarizer are placed between the transparent surface and the light emitting device. The retarder and linear polarizer may attenuate internal reflections from the transparent surface. The light sensor may have two channels and a second linear polarizer may attenuate the ambient light directed toward a second channel. A second retarder may be used with the second linear polarizer to attenuate the ambient light directed toward the second channel. A light detection circuit may use the difference between the two channels of the light sensor to provide the ambient light value.
Public/Granted literature
- US20150122978A1 AMBIENT LIGHT SENSOR WITH INTERNAL LIGHT CANCELLATION Public/Granted day:2015-05-07
Information query