The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 2014
Filed:
Sep. 17, 2010
Jeffrey Raynor, Edinburgh, GB;
Abdelouahid Zakriti, Bouskoura, MA;
Stephane Vivien, Grenoble, FR;
Pascal Mellot, Lans en Vercours, FR;
Jeffrey Raynor, Edinburgh, GB;
Abdelouahid Zakriti, Bouskoura, MA;
Stephane Vivien, Grenoble, FR;
Pascal Mellot, Lans en Vercours, FR;
STMicroelectronics (Research & Development) Limited, Marlow, GB;
STMicroelectronics SAS (Moroc), Bouskoura, MA (US);
STMicroelectronics (Grenoble 2) SAS, Grenoble, FR;
Abstract
Ambient light is detected by a photodiode circuit by measuring the time taken for a digital output of the photodiode circuit to change state in response to exposure of a photodiode of the photodiode circuit to that ambient light. A nominal time for state change is calculated based on photodiode circuit characteristics. Furthermore, an effective time for the photodiode circuit digital output to change state is determined in a calibration mode where the photodiode has been disconnected and a reference current is applied to the circuit. An illumination value of the detected ambient light is then calculated as a function of: the measured time, the effective time and the nominal time.