Image pickup apparatus and control method thereof

• US 10,880,486 B2
• Filed: 11/15/2018
• Issued: 12/29/2020
• Est. Priority Date: 11/17/2017
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kogure, Kentaro
• Primary Examiner(s): Selby, Gevell V
• Application Number:
  US16/191,617
• Publication Number:
  US 20190158752A1
• Time in Patent Office: 775 Days
• CPC Class Codes: G03B 15/02 Illuminating scene
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls

Abstract

An image pickup apparatus aims to control an illuminating part so as to obtain an image of good visibility irrespectively of a state of a zooming operation under dark environment. The image pickup apparatus has an image pickup part including a zoom lens, and a lens driving part configured to drive the zoom lens in an optical axis direction. The image pickup apparatus is capable of performing shooting by using an illuminating part configured to irradiate a subject with light. The image pickup apparatus comprises a control unit configured to control a dimming speed of the illuminating part according to drive information of the zoom lens.

Claims

1. An image pickup apparatus having an image pickup part including a zoom lens, and a lens driving part configured to drive the zoom lens in an optical axis direction, and configured to perform shooting by using an illuminating part configured to irradiate a subject with light, the image pickup apparatus comprising:

at least one processor or circuit programmed to function as;

a control unit configured to change a dimming speed of the illuminating part based on drive information related to the driving of the zoom lens.

2. The image pickup apparatus according to claim 1,

wherein the processor or circuit is further programmed to function as a lens driving determining unit configured to determine whether the zoom lens is being driven, and

wherein the control unit is further configured to change the dimming speed when the lens driving determining unit determines that the zoom lens is being driven, compared to when the lens driving determining unit does not determine that the zoom lens is being driven.

3. The image pickup apparatus according to claim 2,

wherein the processor or circuit is further programmed to function as an illumination determining unit configured to determine whether the illuminating part is activated or deactivated, and

wherein the control unit is further configured to change the dimming speed when the illumination determining unit determines that the illuminating part is activated and the lens driving determining unit determines that the zoom lens is being driven, compared to when the lens driving determining unit does not determine that the zoom lens is being driven.

4. The image pickup apparatus according to claim 1,

wherein the processor or circuit is further programmed to function as a brightness detecting unit configured to detect a brightness of the subject picked up by the image pickup part, and

wherein the control unit is further configured to dim the illuminating part when the brightness of the subject detected by the brightness detecting unit is darker than a predetermined brightness level.

5. The image pickup apparatus according to claim 1, wherein the control unit is further configured to change the dimming speed by changing a rate of a change amount of an illumination intensity of the illuminating part per unit time.

6. The image pickup apparatus according to claim 1,

wherein the processor or circuit is further programmed to function as a movement direction determining unit configured to determine a movement direction of the zoom lens, and

wherein the control unit is further configured to relatively increase the dimming speed when the movement direction determining unit determines that the zoom lens moves toward a tele side compared to when the zoom lens moves toward a wide side.

7. The image pickup apparatus according to claim 1,

wherein the processor or circuit is further programmed to function as a driving speed calculating unit configured to calculate a driving speed at which the lens driving part drives the zoom lens, and

wherein the control unit is further configured to change the dimming speed according to the driving speed of the zoom lens calculated by the driving speed calculating unit.

8. The image pickup apparatus according to claim 7, wherein the driving speed calculating unit is further configured to calculate a driving speed from a current position to a target position of the zoom lens.

9. The image pickup apparatus according to claim 2,

wherein the processor or circuit is further programmed to function as a driving time calculating unit configured to calculate a time during which the lens driving determining unit determines that the zoom lens is being driven, and

wherein the control unit is further configured to change the dimming speed according to a driving time calculated by the driving time calculating unit.

10. The image pickup apparatus according to claim 2,

wherein the processor or circuit is further programmed to function as an obtaining unit configured to obtain an aperture F value per current position of the zoom lens, and

wherein the control unit is further configured to change the dimming speed according to the aperture F value obtained by the obtaining unit.

11. The image pickup apparatus according to claim 1, further comprising a pan-tilt driving apparatus configured to drive at least the image pickup part in a pan direction and a tilt direction, and change a shooting direction of the image pickup part,

wherein the pan-tilt driving apparatus is further configured to obtain a driving speed in the pan direction or the tilt direction, and

the control unit is further configured to change the dimming speed according to the driving speed obtained by the pan-tilt driving apparatus.

12. The image pickup apparatus according to claim 11, wherein the pan-tilt driving apparatus is further configured to change the driving speed in the pan direction or the tilt direction.

13. The image pickup apparatus according to claim 1, wherein the illuminating part is further configured to radiate infrared light.

14. The image pickup apparatus according to claim 1, wherein the illuminating part is configured to be detachable from the image pickup apparatus.

15. A control method for an image pickup apparatus having an image pickup part including a zoom lens, and a lens driving part configured to drive the zoom lens in an optical axis direction, and configured to perform shooting by using an illuminating part configured to irradiate a subject with light, the control method comprising:

changing a dimming speed of the illuminating part based on drive information related to the driving of the zoom lens.

16. The control method according to claim 15, further comprising determining whether the zoom lens is being driven,

wherein the dimming speed is changed when it is determined that the zoom lens is being driven, compared to when it is not determined that the zoom lens is being driven.

17. The control method according to claim 16, further comprising determining whether the illuminating part is activated or deactivated,

wherein the dimming speed is changed when it is determined that the illuminating part is activated and it is determined that the zoom lens is being driven, compared to when it is not determined that the zoom lens is being driven.

18. The control method according to claim 15, further comprising detecting a brightness of the subject picked up by the image pickup part,

wherein the illuminating part is dimmed when the detected brightness of the subject is darker than a predetermined brightness level.

19. The control method according to claim 15, wherein the dimming speed is changed by changing a rate of a change amount of an illumination intensity of the illuminating part per unit time.

20. The control method according to claim 15, further comprising determining a direction of a change in a zoom magnification of the zoom lens,

wherein the dimming speed is relatively increased when it is determined that the zoom magnification changes toward a tele side compared to when the zoom magnification changes toward a wide side.