Light detection circuit for ambient light and proximity sensor
First Claim
1. A circuit for implementing an ambient light sensing mode and a proximity sensing mode, comprising:
- a first light sensor that is more sensitive to light in the infrared spectrum than to light in the visible spectrum;
a light source that emits light in the infrared spectrum;
a second light sensor that is sensitive to light in the visible spectrum; and
a controller coupled to the first light sensor, the light source, and the second light sensor;
wherein the controller is configured to process an ambient light level output from the first light sensor without the light source energized with an output from the first light sensor with the light source energized to implement the proximity sensing mode, andwherein the controller is configured to process an output from the second light sensor to implement the ambient light sensing mode.
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Accused Products
Abstract
A circuit for implementing an ambient light sensing mode and a proximity sensing mode includes a first light sensor that is more sensitive to light in the infrared spectrum than to light in the visible spectrum and a light source that emits light in the infrared spectrum. The circuit further includes a second light sensor that is sensitive to light in the visible spectrum and a controller coupled to the first light sensor, the light source, and the second light sensor. The controller is configured to process an ambient light level output from the first light sensor without the light source energized with an output from the first light sensor with the light source energized to implement a proximity sensing mode. Further, the controller is configured to process an output from the second light sensor to implement an ambient light sensing mode.
35 Citations
18 Claims
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1. A circuit for implementing an ambient light sensing mode and a proximity sensing mode, comprising:
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a first light sensor that is more sensitive to light in the infrared spectrum than to light in the visible spectrum; a light source that emits light in the infrared spectrum; a second light sensor that is sensitive to light in the visible spectrum; and a controller coupled to the first light sensor, the light source, and the second light sensor; wherein the controller is configured to process an ambient light level output from the first light sensor without the light source energized with an output from the first light sensor with the light source energized to implement the proximity sensing mode, and wherein the controller is configured to process an output from the second light sensor to implement the ambient light sensing mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A light sensor circuit, comprising:
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a light sensor and one or more calibration sensors disposed around the light sensor, wherein the light sensor is coupled to an output pin and a bias voltage is applied to the one or more calibration sensors to enhance the sensitivity of the light sensor; and a guard ring disposed around the light sensor and the one or more calibration sensors. - View Dependent Claims (14, 15)
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16. A circuit that models a typical human visual system response to visible light intensity, comprising:
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a first light sensor that is sensitive to both visible light and infrared light, a second light sensor that is more sensitive to light in the infrared spectrum than to light in the visible spectrum; a controller coupled to the first and second light sensors to process the outputs from the first and second light sensors to model the typical human visual system response to visible light intensity, wherein the second sensor includes a P-type substrate with an N-type well formed over the P-type substrate, an N+ doped region disposed within the N-type well, P+ doped regions disposed on opposing sides of the N-type well, and a poly silicon layer over the P-type substrate. - View Dependent Claims (17, 18)
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Specification