Ambient light sensor

Patent metadata

Field	Value
Publication number	US-9869584-B1
Application number	US-201715414894-A
Country	US
Kind code	B1
Filing date	Jan 25, 2017
Priority date	Aug 10, 2016
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

Presented here are devices and methods to correct ambient light measurements made in the presence of optical elements, such as the curved edge of the cover glass associated with the mobile device. In one embodiment, a film with optical properties is placed within the ambient light sensor to diffuse the high-intensity light beam coming from the optical element. In another embodiment, an aperture associated with the ambient light sensor is disposed to prevent the high-intensity light beam from entering the ambient light sensor. In another embodiment, a processor coupled to the ambient light sensor smoothes the peak associated with the high intensity light beam produced by the optical element.

First claim

The invention claimed is:

1. An apparatus with an increased display area, the apparatus comprising:
an ambient light sensor that measures ambient light intensity;
a light focusing element comprising a substantially curved focusing surface positioned proximate to the ambient light sensor, the light focusing element to receive ambient light and to focus ambient light onto the ambient light sensor;
a processor coupled to the ambient light sensor, the processor configured to:
receive a signal from the ambient light sensor comprising a peak corresponding to ambient light focused onto the ambient light sensor by the light focusing element, the peak comprising a high frequency, the signal correlating an incident angle of ambient light to a light intensity, the incident angle of ambient light defined with respect to the ambient light sensor;
determine a plurality of points associated with the signal such that the plurality of points are outside the peak associated with the signal;
replace the peak with a plurality of values interpolated based on the plurality of points to produce a smooth signal; and
based on the smooth signal, determine ambient light intensity.

2. The apparatus of claim 1 , the processor configured to
perform a low-pass filter operation on the signal to remove the high frequency corresponding to the peak and to produce the smooth signal.

3. An apparatus with an increased display area, the apparatus comprising:
a light focusing element comprising a substantially curved focusing surface to receive ambient light, to focus ambient light, and to produce a focused light beam comprising a high light intensity, the light focusing element comprising a curved portion of a cover glass associated with an electronic display;
an ambient light sensor positioned proximate to the light focusing element, the ambient light sensor to receive the focused light beam from the light focusing element, the ambient light sensor comprising:
a film disposed between the light focusing element and a photodiode, the film to ameliorate the high light intensity associated with the focused light beam, the film comprising an optically opaque region, the optically opaque region disposed within the film to prevent the focused light beam from entering the ambient light sensor; and the photodiode coupled to the film, the photodiode to measure ambient light intensity.

4. An apparatus with an increased display area, the apparatus comprising:
a light focusing element comprising a substantially curved focusing surface to receive ambient light, to focus ambient light, and to produce a focused light beam comprising a high light intensity, the light focusing element comprising a curved portion of a cover glass associated with an electronic display;
an ambient light sensor positioned proximate to the light focusing element, the ambient light sensor to receive the focused light beam from the light focusing element, the ambient light sensor comprising:
an aperture frame defining an aperture, the aperture frame disposed on top of a photodiode, the aperture frame to block the focused light beam from reaching the photodiode; the aperture asymmetrically disposed within the aperture frame, the aperture to transmit ambient light, the aperture formed into a shape preventing the focused light beam from entering the aperture; a film disposed between the light focusing element and the aperture, comprising an optically opaque region, the optically opaque region disposed within the film to prevent the focused light beam from entering the ambient light sensor; and the photodiode coupled to the aperture, the photodiode to measure ambient light intensity.

5. A method to increase display area of a device, the method comprising:
receiving a signal from an ambient light sensor, wherein the signal correlates an incident angle of ambient light to a light intensity, the incident angle of ambient light defined with respect to the ambient light sensor, wherein the signal comprises a peak corresponding to incoming light focused by a light focusing element comprising a substantially curved focusing surface, and wherein the peak comprises a high frequency; smoothing the peak corresponding to incoming light focused by the light focusing element to produce a smooth signal, said smoothing the peak comprising: determining a plurality of points associated with the signal such that the plurality of points are outside the peak associated with the signal; replacing the peak with values interpolated based on the plurality of points; and based on the smooth signal, determining ambient light intensity.

6. The method of claim 5 , said smoothing the peak comprising: performing a low-pass filter operation on the signal to remove the high frequency corresponding to the peak, and to produce the smooth signal.

7. An apparatus to measure ambient light intensity the apparatus comprising: an ambient light sensor that measures ambient light intensity;
a light focusing element positioned proximate to the ambient light sensor to receive ambient light and to focus ambient light onto the ambient light sensor;
a processor coupled to the ambient light sensor, the processor configured to:
receive a signal from the ambient light sensor comprising a peak corresponding to ambient light focused onto the ambient light sensor by the light focusing element, the peak comprising a high frequency, the signal correlating an incident angle of ambient light to a light intensity, the incident angle of ambient light defined with respect to the ambient light sensor;
determine a plurality of points associated with the signal such that the plurality of points are outside the peak associated with the signal;
replace the peak with a plurality of values interpolated based on the plurality of points, thereby producing a smooth signal; and
based on the smooth signal, determine ambient light intensity.

8. A method to correct ambient light intensity measurement the method comprising: receiving a signal from an ambient light sensor, wherein the signal correlates an incident angle to a light intensity, the incident angle defined with respect to the ambient light sensor, wherein the signal comprises a peak corresponding to incoming light focused by a light focusing element, and wherein the peak comprises a high frequency; determining a plurality of points associated with the signal such that the plurality of points are outside the peak associated with the signal; replacing the peak with values interpolated based on the plurality of points; and based on the smooth signal, determining ambient light intensity.

Assignees

• Essential Products Inc

Inventors

• Evans V David John
• Jiang Xinrui
• Rubin Andrew E
• Hershenson Matthew
• Miao Xiaoyu
• Tate Joseph Anthony
• Gagne-Keats Jason Sean
• Zavin Rebecca Schultz

Classifications

• G01J2001/444

  Compensating; Calibrating, e.g. dark current, temperature drift, noise reduction or baseline correction; Adjusting · CPC title

• G01J2001/446

  Photodiode · CPC title

• G01J1/44 Primary

  Electric circuits {(for command of an exposure part G03B7/02)} · CPC title

• G01J1/0411

  using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction · CPC title

• G01J1/0418

  using attenuators · CPC title