Camera with LED illumination

• US 10,218,916 B2
• Filed: 01/05/2018
• Issued: 02/26/2019
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google LLC (Alphabet Inc.)
• Inventors: Dorai, Arvind, Nelson, Anders, Conner, Brian Jonathan
• Primary Examiner(s): Pasiewicz, Daniel M
• Application Number:
  US15/863,567
• Publication Number:
  US 20180167543A1
• Time in Patent Office: 417 Days
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: H04N 23/20 for generating image signals from infrared radiation only
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: H05B 45/39 Circuits containing inverter bridges
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices

Abstract

This application discloses a camera including a camera lens, a plurality of light sources and bypass circuit. The camera lens is configured to capture visual data of a field of view, and the light sources are configured to illuminate the field of view. The bypass circuit is coupled to the light sources, and configured to group the light sources into a plurality of light source subsets. At least two of the light source subsets include distinct light source members to illuminate different regions of the field of view of the camera. The camera includes a first mode in which the light sources are electrically coupled in series to form a string and driven by a boosted drive voltage, and a second mode in which one of the light source subsets is selected and driven by a regular drive voltage that is lower than the boosted drive voltage.

Claims

1. A camera, comprising:

a camera lens configured to capture visual data of a field of view;

a plurality of light sources configured to illuminate the field of view; and

bypass circuit coupled to the plurality of light sources and configured to bypass a subset of the plurality of light sources, wherein the bypass circuit is configured to select one of a plurality of light source subsets, and at least two of the plurality of light source subsets include distinct light source members configured to illuminate different regions of the field of view of the camera;

wherein;

the camera includes a first mode and a second mode;

in the first mode, the plurality of light sources are electrically coupled to form a string and driven by a boosted drive voltage; and

in the second mode, the one of the plurality of light source subsets is selected and driven by a regular drive voltage that is lower than the boosted drive voltage.

2. The camera of claim 1, wherein the plurality of light sources includes eight light sources, and in the second mode, six of the eight light sources are bypassed, and two remaining light sources are coupled in series and driven by the regular drive voltage.

3. The camera of claim 1, wherein the plurality of light sources includes a plurality of light emitting diodes (LEDs).

4. The camera of claim 3, wherein the plurality of LEDs is disposed to surround the camera lens.

5. The camera of claim 4, wherein each LED is tilted with an angle with respect to an optical axis of the camera lens.

6. The camera of claim 5, wherein each LED is tilted away from the optical axis of the camera with the angle in the range of 20-40 degrees.

7. The camera of claim 3, wherein the plurality of LEDs includes a plurality of infrared LEDs.

8. The camera of claim 7, further comprising:

a dark-colored infrared-transparent cover enclosing the plurality of infrared LEDs, wherein the plurality of infrared LEDs are not visible from an exterior of the camera.

9. The camera of claim 1, wherein the plurality of light sources are disposed symmetrically with respect to the camera lens.

10. The camera of claim 1, wherein the plurality of light sources includes one or more infrared light source and one or more visible light source, and in a night mode associated with the second mode, the one or more infrared light source is driven to illuminate at least part of the field of view with infrared light.

11. The camera of claim 1, wherein the bypass circuit includes a plurality of bypass elements, and each light source is coupled in parallel with one of the plurality of bypass elements configurable to bypass the respective light source in the second mode.

12. An electronic device, comprising:

a camera lens configured to capture visual data of a field of view;

a plurality of light sources configured to illuminate the field of view; and

bypass circuit coupled to the plurality of light sources and configured to bypass a subset of the plurality of light sources, wherein the bypass circuit is configured to select one of a plurality of light source subsets, and at least two of the plurality of light source subsets include distinct light source members configured to illuminate different regions of the field of view of the camera;

wherein;

the camera includes a first mode and a second mode;

in the first mode, the plurality of light sources are electrically coupled to form a string and driven by a boosted drive voltage; and

in the second mode, the one of the plurality of light source subsets is selected and driven by a regular drive voltage that is lower than the boosted drive voltage.

13. The electronic device of claim 12, further comprising:

a microcontroller coupled to the bypass circuit, wherein the microcontroller is configured to control the bypass circuit to bypass the subset of the plurality of light sources in the second mode, thereby selecting the one of the plurality of light source subsets.

14. The electronic device of claim 12, wherein the bypass circuit includes a plurality of bypass elements, and each light source is coupled in parallel with one of the plurality of bypass elements configurable to bypass the respective light source in the second mode.

15. The electronic device of claim 12, wherein the plurality of light sources is grouped into four subsets of light sources that are configured to illuminate four quadrants of the field of view, respectively.

16. The electronic device of claim 15, wherein depth information of the field of view is recovered at night time according to the variation of the field of view illuminated by these four subsets of light sources.

17. A method of providing a camera, comprising:

providing a camera lens configured to capture visual data of a field of view;

providing a plurality of light sources configured to illuminate the field of view; and

coupling bypass circuit to the plurality of light sources, wherein the bypass circuit is configured to bypass a subset of the plurality of light sources and select one of a plurality of light source subsets, and at least two of the plurality of light source subsets include distinct light source members configured to illuminate different regions of the field of view of the camera;

wherein;

the camera includes a first mode and a second mode;

in the first mode, the plurality of light sources are electrically coupled to form a string and driven by a boosted drive voltage; and

in the second mode, the one of the plurality of light source subsets is selected and driven by a regular drive voltage that is lower than the boosted drive voltage.

18. The method of claim 17, wherein the plurality of light sources includes eight LEDs, and wherein in the second mode, six of the eight LEDs are bypassed, and two remaining LEDs are coupled in series and driven by the regular drive voltage.

19. The method of claim 17, wherein:

when driven by the boosted drive voltage in the first mode, the plurality of light sources is associated with a first drive current; and

when driven by the regular drive voltage in the second mode, the selected one of the plurality of light source subsets is associated with a second drive current that is distinct from the first drive voltage.

20. The method of claim 17, further comprising:

providing image sensors, a microphone, a speaker, and one or more antennas, wherein the camera is configured to communicate the visual data to a client device via a remote surveillance server in real time while capturing the visual data.