Optical sensor capable of detecting IR light and visible light simultaneously

• US 9,093,342 B2
• Filed: 03/23/2012
• Issued: 07/28/2015
• Est. Priority Date: 03/25/2011
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Hsu, En-Feng, Liao, Chi-Chieh
• Primary Examiner(s): Bryant, Casey
• Application Number:
  US13/427,912
• Publication Number:
  US 20120241618A1
• Time in Patent Office: 1,222 Days
• Field of Search: 250/339.01, 250/339.05, 257/432
• US Class Current: 1/1
• CPC Class Codes: H01L 27/1462 Coatings
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14645 Colour imagers
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H01L 27/14649 Infrared imagers

Abstract

An optical sensor includes an image sensor, a proximity sensor and a visible light sensor. The image sensor includes a first pixel and a second pixel. The first pixel is coated with a first optical film for blocking light whose wavelength is outside a first predetermined range and a second optical film for blocking light whose wavelength is outside a second predetermined range. The proximity sensor generates an IR signal according to a first exposure value. The visible light sensing unit generates a visible light signal according to the difference between the first exposure and a second exposure value or according to a ratio of the first exposure value to the second exposure value. The first exposure value represents an incident light quantity which is absorbed by the first pixel. The second exposure value represents an incident light quantity which is absorbed by the second pixel.

Claims

1. An optical sensor, comprising:

an image sensor, comprising;

a first pixel coated with two optical films, wherein a first optical film is configured to block light whose wavelength is outside a first predetermined range, and a second optical film is on the first optical film and configured to block light whose wavelength is outside a second predetermined range; and

a second pixel without being coated with any optical film; and

a processing unit configured to simultaneously receive pixel data measured by the first pixel and the second pixel and generate an electrical signal accordingly, wherein the first predetermined range and the second predetermined range are not overlapped.

2. The optical sensor of claim 1, wherein the first predetermined range and the second predetermined range are different and selected from 380-500 nm, 500-600 nm, and 600-780 nm.

3. The optical sensor of claim 1, wherein the processing unit comprises a proximity sensor configured to generate an infrared radiation (IR) electrical signal according to a first exposure value, wherein the first exposure value represents an incident light quantity which is absorbed by the first pixel.

4. The optical sensor of claim 1, wherein the processing unit comprises a visible light sensor configured to generate a visible light electrical signal according to a difference between a first exposure value and a second exposure value or according to a ratio of the first exposure value to the second exposure value, wherein the first exposure value represents an incident light quantity which is absorbed by the first pixel, and the second exposure value represents an incident light quantity which is absorbed by the second pixel.