Image pickup auxiliary light source device and digital camera provided with same

Patent metadata

Field	Value
Publication number	US-9451665-B2
Application number	US-201214365716-A
Country	US
Kind code	B2
Filing date	Dec 10, 2012
Priority date	Dec 20, 2011
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

An illumination device has LEDs, EDLCs for LED use, and a non-volatile memory for recording the difference between the color temperature and/or the illumination spectrum of LEDs and Xe gas. The unused charge in an EDLC is recovered by a power cell. Illumination strength is changed in accordance with the image pickup distance of a DSC. Illumination strength is changed in accordance with exposure time so that a fill-in ratio is maintained. The illumination strength of LEDs is gradually increased and then at the peak strength is suddenly reduced. The mixture ratio of light from LEDs having different light distributions is changed due to focal distance, and then an incidence angle is changed. A group of LEDs is disposed in a ring shape on the front of a lens. During continuous capture, LEDs are caused to illuminate continuously or synchronously.

First claim

The invention claimed is:

1. An image pickup auxiliary light source device comprising:
a light emitting diode;
an electric double-layer capacitor that supplies electric power to the light emitting diode; and
a non-volatile memory that stores illumination color information of the light emitting diode for color correction in processing an image picked up under illumination by the light emitting diode,
wherein the electric double-layer capacitor is supplied with electric power from a rechargeable power source battery, and wherein the image pickup auxiliary light source device further comprises a switchover control portion that performs a switchover between power supply from the electric double-layer capacitor to the light emitting diode and power supply directly from the rechargeable power source battery to the light emitting diode without passing through the electric double-layer capacitor.

2. The image pickup auxiliary light source device according to claim 1 , wherein the non-volatile memory stores color information relevant to color temperature and emission spectrum of the light emitting diode on the basis of the color temperature and emission spectrum of xenon gas.

3. The image pickup auxiliary light source device according to claim 2 , wherein the non-volatile memory stores color information relevant to deviation of the color temperature and emission spectrum of the light emitting diode from the color temperature and emission spectrum of the xenon gas.

4. The image pickup auxiliary light source device according claim 1 , further comprising a rechargeable power source battery and a charge control portion that transfers electric charges from the rechargeable power source battery to the electric double-layer capacitor, and returns accumulated electric charges from the electric double-layer capacitor to the power source battery.

5. The image pickup auxiliary light source device according to claim 1 , further comprising a pulse width modulation portion that controls power supply performed from the electric double-layer capacitor to the light emitting diode to control a time-dependent change in illumination intensity of the light emitting diode.

6. The image pickup auxiliary light source device according to claim 1 further comprising an illumination control portion that the illumination intensity of the light emitting diode at a constant intensity within a period.

7. A digital camera comprising the image pickup auxiliary light source device according to claim 6 , wherein the illumination control portion is further arranged to vary the constant intensity in accordance with an exposure period of the digital camera.

8. The image pickup auxiliary light source device according to claim 1 further comprising an illumination control portion that increases gradually the illumination intensity of the light emitting diode and decreases the illumination intensity sharply from a peak thereof.

9. A digital camera comprising the image pickup auxiliary light source device according to claim 8 , wherein the illumination control portion is arranged to gradually increases the illumination intensity of the light emitting diode during an exposure period of the digital camera and sharply decreases the illumination intensity from the peak thereof.

10. The image pickup auxiliary light source device according to claim 1 , comprising a plurality of the light emitting diodes that are different from one another in light distribution, the plurality of the light emitting diodes are supplied with electric power from the electric double layer capacitor.

11. A digital camera comprising the image pickup auxiliary light source device according to claim 10 further comprising
an illumination control portion that controls separately the plurality of light emitting diodes which are different from one another in light distribution.

12. A digital camera comprising the image pickup auxiliary light source device according to claim 1 , the digital camera further comprising an image pickup portion and an image process portion that processes the image picked up by the image pickup portion, wherein the color information of the light emitting diode stored in the non-volatile memory is reflected into color correction by the image process portion in processing the image to correct deviation of the color temperature and emission spectrum of the light emitting diode from the color temperature and emission spectrum of the xenon gas.

13. The digital camera according to claim 12 further comprising:
a zoom lens; and
an illumination control portion that changes light distribution of the image pickup auxiliary light source in accordance with a focal distance of the zoom lens.

14. A digital camera according to claim 12 further comprising:
an illumination control portion that changes an illumination intensity of the light emitting diode in accordance with an image pickup distance of the digital camera.

15. The digital camera according to claim 12 further comprising:
an image pickup lens and
a plurality of light emitting diodes that are disposed concentrically around an optical axis of the image pickup lens and are supplied with electric power from the electric double-layer capacitor to generate image pickup auxiliary light.

16. The digital camera according to claim 12 further comprising a camera control portion that receives the color information of the light emitting diode from the non-volatile memory to reflect the color information into color correction by the image process portion in processing the image.

17. The digital camera according to claim 16 , wherein the camera control portion is arranged to receive the color information of the light emitting diode from the non-volatile memory when the light emitting diode is built into the digital camera.

18. A digital camera comprising:
a light emitting diode;
an electric double-layer capacitor that is supplied with electric power from a rechargeable power source battery;
an illumination control portion that supplies electric power from the electric double-layer capacitor to the light emitting diode to generate image pickup auxiliary light, and supplies electric power from the rechargeable power source battery to the light emitting diode without passing through the electric double-layer capacitor to perform flicker illumination for reducing red eye; and
a switchover control portion that performs a switchover between the power supply from the electric double-layer capacitor to the light emitting diode and the power supply directly from the rechargeable power source battery to the light emitting diode without passing through the electric double-layer capacitor.

19. A digital camera comprising:
a light emitting diode;
an electric double-layer capacitor that is supplied with electric power from a rechargeable power source battery; and
an illumination control portion that supplies electric power from the electric double-layer capacitor to the light emitting diode to generate image pickup auxiliary light, and supplies electric power from the rechargeable power source battery to the light emitting diode without passing through the electric double-layer capacitor to perform self-timer display illumination; and
a switchover control portion that performs a switchover between the power supply from the electric double-layer capacitor to the light emitting diode and the power supply directly from the rechargeable power source battery to the light emitting diode without passing through the electric double-layer capacitor.

Assignees

• Rohm Co Ltd

Inventors

• Sato Tadayoshi
• Tanaka Masahide

Classifications

• H04N23/74

  by influencing the scene brightness using illuminating means · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• H04N23/671 Primary

  in combination with active ranging signals, e.g. using light or sound signals emitted toward objects · CPC title

• G03B7/08 Primary

  Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device · CPC title

• H04N23/69

  Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming · CPC title