Systems and methods for autofocus trigger

• US 9,703,175 B2
• Filed: 07/02/2015
• Issued: 07/11/2017
• Est. Priority Date: 07/02/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Dayana, Venkata Ravi Kiran, Shanmugavadivelu, Karthikeyan, Lou, Ying Chen, Ravirala, Narayana Karthik Sadanandam, Wu, Hung-Hsin, Golikeri, Adarsh Abhay, Liu, Shizhong
• Primary Examiner(s): Laballe, Clayton E
• Assistant Examiner(s): Smith, Linda B
• Application Number:
  US14/791,035
• Publication Number:
  US 20170003573A1
• Time in Patent Office: 740 Days
• Field of Search: 396125
• CPC Class Codes: G03B 13/36 Autofocus systems
• CPC Class Codes: H04N 23/959 by adjusting depth of field during image capture, e.g. maximising or setting range based on scene characteristics

Abstract

Method and systems for autofocus triggering focusing are disclosed herein. In one example, a system may include a lens, a memory component configured to store lens parameters of the lens and regions of focus corresponding to the lens parameters, and a processor coupled to the memory and the lens. The processor may be configured to focus the lens on a target object at a first instance of time, receive information indicative of distances from an imaging device to the target object over a period of time, obtain lens parameters of the lens, and determine a region of focus, and trigger the lens to re-focus on the target object if the distance to the target object indicates the target object is outside of the region of focus and the distance to the target object is unchanged for a designated time period.

Claims

1. A focusing system, comprising:

a first lens;

a memory component configured to store lens parameters of the first lens and distance ranges of focus corresponding to the lens parameters; and

a processor coupled to the memory and the first lens, the processor configured to

focus the first lens on a target object at a first focus positon at a first instance of time,

receive information indicative of distances from an imaging device to the target object over a period of time, the first instance of time included in the period of time,

obtain lens parameters of the first lens at the first focus position at the first instance of time,

determine a distance range of focus of the first lens at the first focus position based on the distance at the first instance of time and lens parameters at the first instance of time; and

trigger the first lens to re-focus on the target object if the distance to the target object indicates the target object is outside of the distance range of focus at the first focus position and the distance to the target object is unchanged for a designated time period stored in the memory component.

2. The system of claim 1, wherein the lens parameters comprise information indicative of an aperture of the first lens and information indicative of a focal length of the first lens at the first instance of time.

3. The system of claim 1, wherein the processor is further configured to access the memory component to retrieve lens parameters of the first lens and use the retrieved lens parameters to determine the distance range of focus.

4. The system of claim 1, wherein the memory component is configured with lens parameters and associated distance ranges of focus, and the processor is further configured to retrieve from the memory component a distance range of focus associated with the lens parameters of the first lens at the first instance of time.

5. The system of claim 1, wherein the designated time period comprises a predetermined time period.

6. The system of claim 1, wherein the processor is further configured to determine a depth of field associated with the first focus position and lens parameters of the first lens, wherein the distance range of focus is determined based on a predetermined distance within the determined depth of field.

7. The system of claim 1, further comprising a range finding system coupled with the processor, the range finding system configured to send to the processor the information indicative of distance from the imaging device to the target object.

8. The system of claim 7, wherein the range finding system comprises the first lens and a second lens, and the range finding system is configured to determine information indicative of the distance from the imaging device to the target object based on a disparity between an image generated using the first lens and an image generated using the second lens.

9. The system of claim 7, wherein the range finding system comprises a light emitter, and wherein the range finding system is configured to determine information indicative of the distance from the imaging device to the target object based on receiving light that is emitted by the light emitter and reflected from the target object.

31. The method of claim 1, wherein the predetermined time period is more than one consecutive frame.

10. A method of focusing, comprising:

storing, in a memory component, lens parameters of a first lens and distance ranges of focus corresponding to the lens parameters;

focusing the first lens on a target object at a first focus position and at a first instance of time,

receiving information indicative of distances from an imaging device to the target object over a period of time, the first instance of time included in the period of time,

obtaining lens parameters of the first lens at the first focus position and at the first instance of time,

determining a distance range of focus at the first focus position based on the distance at the first instance of time and lens parameters at the first instance of time; and

triggering the first lens to re-focus on the target object if the distance to the target object indicates the target object is outside of the distance range of focus at the first focus position and the distance to the target object is unchanged for a designated time period stored in the memory component.

11. The method of claim 10, wherein the lens parameters comprise information indicative of an aperture of the first lens and information indicative of a focal length of the first lens at the first instance of time.

12. The method of claim 10, further comprising accessing the memory component to retrieve lens parameters of the first lens and use the retrieved lens parameters to determine the distance range region of focus.

13. The method of claim 10, wherein the designated period of time comprises a predetermined time period.

14. The method of claim 10, further comprising determining a depth of field associated with the first focus position and lens parameters of the first lens, wherein the distance range of focus is determined based on a predetermined distance within the determined depth of field.

15. The method of claim 10, further comprising determining information indicative of the distance from the imaging device to the target object based on a disparity between an image generated using the first lens and an image generated using a second lens.

16. The method of claim 10, further comprising determining information indicative of the distance from the imaging device to the target object based on emitting light to the target object and receiving reflected light from the target object.

17. A system, comprising:

means for storing lens parameters of a first lens and distance ranges regions of focus corresponding to the lens parameters;

means for focusing the first lens on a target object at a first focus position and at a first instance of time,

means for receiving information indicative of distances from an imaging device to the target object over a period of time, the first instance of time included in the period of time,

means for obtaining lens parameters of the first lens at the first focus position and at the first instance of time,

means for determining a distance range of focus at the first focus position based on a distance at the first instance of time and lens parameters at the first instance of time; and

means for triggering the first lens to re-focus on the target object if the distance to the target object indicates the target object is outside of the distance range of focus at the first focus position and the distance to the target object is unchanged for a designated time period stored in the means for storing.

18. The system of claim 17, wherein the lens parameters comprise information indicative of an aperture of the first lens and information indicative of a focal length of the first lens at the first instance of time.

19. The system of claim 17, further comprising means for retrieving lens parameters of the first lens and using the retrieved lens parameters to determine the distance range of focus.

20. The system of claim 17, wherein the designated period of time comprises a predetermined time period.

21. The system of claim 17, wherein the means for determining a distance range of focus is further configured to determine a depth of field associated with the first focus position and lens parameters of the first lens, wherein the distance range of focus is determined based on a predetermined distance within the determined depth of field.

22. The system of claim 17, further comprising means for determining information indicative of the distance from the imaging device to the target object based on a disparity between an image generated using the first lens and an image generated using a second lens.

23. The system of claim 17, further comprising means for determining information indicative of the distance from the imaging device to the target object based on emitting light to the target object and receiving reflected light from the target object.

24. A non-transitory computer-readable medium storing instructions that, when executed by one or more computing devices, perform a method comprising:

storing, in a memory component, lens parameters of a first lens and distance ranges of focus corresponding to the lens parameters;

focusing the first lens on a target object at a first focus position at a first instance of time,

receiving information indicative of distances from an imaging device to the target object over a period of time, the first instance of time included in the period of time,

obtaining lens parameters of the first lens at the first focus position and at the first instance of time,

determining a distance range of focus at the first focus position based on the distance at the first instance of time and lens parameters at the first instance of time; and

triggering the first lens to re-focus on the target object if the distance to the target object indicates the target object is outside of the distance range of focus at the first focus position and the distance to the target object is unchanged for a designated time period stored in the memory component.

25. The non-transitory computer-readable medium of claim 24, wherein the lens parameters comprise information indicative of an aperture of the first lens and information indicative of a focal length of the first lens at the first instance of time.

26. The non-transitory computer-readable medium of claim 24, where the method further comprises accessing the memory component to retrieve lens parameters of the first lens and use the retrieved lens parameters to determine the distance range of focus.

27. The non-transitory computer-readable medium of claim 24, wherein the designated period of time comprises a predetermined time period.

28. The non-transitory computer-readable medium of claim 24, the method further comprising determining a depth of field associated with the first focus position and lens parameters of the first lens, wherein the distance range of focus is determined based on a predetermined distance within the determined depth of field.

29. The non-transitory computer-readable medium of claim 24, wherein the method further comprises determining information indicative of the distance from the imaging device to the target object based on a disparity between an image generated using the first lens and an image generated using a second lens.

30. The non-transitory computer storage of claim 24, further comprising determining information indicative of the distance from the imaging device to the target object based on emitting light to the target object and receiving reflected light from the target object.