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Patent Issued for Light Sensor Having IR Cut and Color Pass Interference Filter Integrated On-Chip

August 27, 2014



By a News Reporter-Staff News Editor at Journal of Engineering -- A patent by the inventors Holenarsipur, Prashanth (Fremont, CA); Wang, Zhihai (Sunnyvale, CA); Kerness, Nicole D. (Menlo Park, CA), filed on October 2, 2013, was published online on August 12, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8803270 is assigned to Maxim Integrated Products, Inc. (San Jose, CA).

The following quote was obtained by the news editors from the background information supplied by the inventors: "Electronic devices, such as smart phones, tablet computers, digital media players, and so forth, increasingly employ light sensors to control the manipulation of a variety of functions provided by the device. For example, light sensors may be used by an electronic device to detect ambient lighting conditions in order to control the brightness of the device's display screen. Typical light sensors employ photodetectors such as photodiodes, phototransistors, or the like, which convert received light into an electrical signal (e.g., a current or voltage). However, the response of such photodetectors can be influenced by the presence of infrared (IR) light (i.e., electromagnetic radiation having a wavelength greater than approximately 700 nanometers (nm) that can be detected by the photodetector). For example, a light sensor of an electronic device may indicate that the surrounding ambient environment is 'brighter' than it really is because the surrounding lighted environment contains a larger proportion of infrared light than normal, such as where the surrounding lighted environment is furnished by artificial lighting, and so forth."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "A light sensor is described that includes an IR interference filter and at least one color interference filter integrated on-chip (i.e., integrated on the die of the light sensor). In one or more implementations, the light sensor comprises a semiconductor device (e.g., a die) that includes a substrate. Photodetectors (e.g., photodiodes, phototransistors, etc.) are disposed proximate to the surface of the substrate. An IR interference filter is disposed over the photodetectors. The IR interference filter is configured to filter infrared light from light received by the light sensor to at least substantially block infrared light from reaching the photodetectors. At least one color interference filter is disposed above or below the IR interference filter. The color interference filter is configured to filter visible light received by the light sensor to pass light in a limited spectrum of wavelengths (e.g., light having wavelengths between a first wavelength and a second wavelength) to at least one of the photodetectors. The photodetectors may also comprise one or more clear photodetectors configured to receive light that is not filtered by a color interference filter, thereby allowing the clear photodetector to detect the ambient light environment.

"This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter."

URL and more information on this patent, see: Holenarsipur, Prashanth; Wang, Zhihai; Kerness, Nicole D.. Light Sensor Having IR Cut and Color Pass Interference Filter Integrated On-Chip. U.S. Patent Number 8803270, filed October 2, 2013, and published online on August 12, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8803270.PN.&OS=PN/8803270RS=PN/8803270

Keywords for this news article include: Maxim Integrated Products Inc.

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Source: Journal of Engineering


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