Apparatus, a method, and a computer program for automatic focusing

Patent metadata

Field	Value
Publication number	US-9167143-B2
Application number	US-200913514014-A
Country	US
Kind code	B2
Filing date	Dec 7, 2009
Priority date	Dec 7, 2009
Publication date	Oct 20, 2015
Grant date	Oct 20, 2015

Abstract

An apparatus ( 500 ) comprises: an image detector ( 122 ) for capturing an image frame (F N ), a driving unit ( 200 ) for adjusting focusing of light onto said image detector ( 122 ), and a pulse generating unit ( 120 ), wherein said pulse generating unit ( 120 ) is configured to generate one or more synchronization pulses (S 11 , S 12 ) based on the timing of optical exposure of a predetermined portion (TRIGLN) of said image frame (F N ), and said driving unit ( 200 ) is configured to perform said adjusting based on the timing of said one or more synchronization pulses (S 11 , S 12 ).

First claim

The invention claimed is:

1. An apparatus comprising:
an image detector for capturing an image frame,
a driving unit for adjusting focusing of light onto said image detector, and
a synchronization signal generating unit,
wherein said synchronization signal generating unit is configured to generate a synchronization signal corresponding to a start time of optical exposure of a predetermined portion of said image frame, and said driving unit is configured to initiate said adjusting based on a timing of said synchronization signal, and
wherein said synchronization signal generating unit is further configured to generate a plurality of successive synchronization signals, and said apparatus further comprises a control unit configured to change a value of a delay parameter which specifies a time delay between said synchronization signals.

2. The apparatus of claim 1 wherein optical exposure of a first portion of said image frame is configured to take place earlier than optical exposure of a second portion of said image frame.

3. The apparatus of claim 1 wherein said synchronization signal generating unit is configured to generate at least one synchronization signal when the optical exposure of said predetermined portion is started.

4. The apparatus of claim 1 wherein said synchronization signal generating unit is configured to generate at least one synchronization signal when the optical exposure of said predetermined portion is finished.

5. The apparatus according to claim 1 wherein said predetermined portion is a predetermined line of pixels of said image frame.

6. The apparatus according to claim 1 comprising a first parameter register having a re-writable parameter, which specifies the location of said predetermined portion with respect to said image frame.

7. The apparatus of claim 6 wherein said first parameter register comprises a re-writable parameter specifying the number of said synchronization signals and/or the time delay between said synchronization signals.

8. The apparatus according to claim 1 comprising a second parameter register having a re-writable parameter specifying direction and/or magnitude for said adjusting.

9. The apparatus of claim 8 wherein the control unit is configured to write either an end point for a focus adjustment or a magnitude for a focus adjustment to said second register, depending on the value of a parameter.

10. The apparatus of claim 8 herein said second register comprises a parameter, which specifies whether said adjusting is performed by using a single magnitude of adjustment or by using two different magnitudes of adjustment.

11. The apparatus according to claim 8 wherein said driving unit comprises said second register.

12. The apparatus according to claim 8 wherein said first register and said second register are located on different semiconductor chips.

13. A method comprising:
capturing an image frame by an image detector,
adjusting focusing of light onto said image detector by a driving unit,
generating a synchronization signal corresponding to a start time of optical exposure of a predetermined portion of said image frame,
initiating said adjusting based on a timing of said synchronization signal,
generating a plurality of successive synchronization signals, and
changing a value of a delay parameter, which specifies a time delay between said synchronization signals.

14. The method of claim 13 wherein optical exposure of a first portion of said image frame takes place earlier than optical exposure of a second portion of said image frame.

15. The method of claim 13 wherein at least one synchronization signal is generated when the optical exposure of said predetermined portion is started.

16. The method of claim 13 wherein at least one synchronization signal is generated when the optical exposure of said predetermined portion is finished.

17. The method according to claim 13 wherein said predetermined portion is a predetermined line of pixels of said image frame.

18. The method according to claim 13 comprising changing the value of a trigger parameter stored in a first parameter register, said trigger parameter specifying the location of said predetermined portion with respect to said image frame.

19. The method of claim 13 wherein said delay parameter is stored in said driving unit.

20. The method of claim 18 comprising storing the trigger parameter and the delay parameter in parameter registers, which are located on different semiconductor chips.

21. The method according to claim 13 comprising changing the value of a parameter specifying direction and/or magnitude for said adjusting.

22. The method according to claim 13 comprising checking the value of an identifier, and writing either an end point for a focus adjustment or a magnitude for a focus adjustment to a second register, depending on the value of said identifier.

23. The method according to claim 13 comprising performing said adjusting by using two different magnitudes of adjustment.

24. A computer program product comprising a non-transitory computer readable medium having executable program code stored thereon, which when executed by a processor causes an apparatus to perform the method according to claim 13 .

25. A device for adjusting focusing of light onto an image detector, wherein said device comprises an input for receiving a synchronization signal corresponding to a start time of optical exposure of a predetermined portion of an image frame, and said device is configured to start said adjusting based on a timing of said synchronization signal, wherein said input is further configured to receive a plurality of successive synchronization signals, and wherein a changeable value of a delay parameter specifies a time delay between said synchronization signals.

26. The device of claim 25 comprising a second parameter register, wherein said second parameter register comprises a parameter specifying direction and/or magnitude for said adjusting.

27. A device comprising:
an image detector for capturing an image frame,
a synchronization signal generating unit configured to generate a synchronization signal corresponding to a start time of optical exposure of a predetermined portion of said image frame, and
an output for transmitting said synchronization signal to a driving unit for adjusting focusing of light onto said image detector, wherein said driving unit is configured to initiate said adjusting based on a timing of said synchronization signal, and
wherein said synchronization signal generating unit is further configured to generate a plurality of successive synchronization signals, and said device further comprises a control unit configured to change a value of a delay parameter which specifies a time delay between said synchronization signals.

28. The device of claim 27 comprising a first parameter register, wherein said first parameter register comprises a parameter specifying the location of said predetermined portion with respect to said image frame.

29. An apparatus comprising:
a means for capturing an image frame,
a means for adjusting focusing of light onto said image detector, and
a means for generating synchronization signals,
wherein said means for generating synchronization signals is configured to generate a synchronization signal corresponding to a start time of optical exposure

Assignees

• Ollila Mikko
• Muukki Mikko
• Nokia Technologies Oy

Inventors

• Ollila Mikko
• Muukki Mikko

Classifications

• H04N23/665 Primary

  involving internal camera communication with the image sensor, e.g. synchronising or multiplexing SSIS control signals · CPC title

• H04N23/673

  based on contrast or high frequency components of image signals, e.g. hill climbing method · CPC title

• H04N5/23212

  Electricity · mapped topic

• H04M1/0264

  for a camera module assembly · CPC title

• G02B7/36 Primary

  using image sharpness techniques {, e.g. image processing techniques for generating autofocus signals (image data processing per se G06T; in cameras having a solid state image sensor H04N23/67)} · CPC title