LIGHT CONTROL OF A FLASH UNIT

• US 20100059659A1
• Filed: 10/09/2008
• Published: 03/11/2010
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Inventors: KLINGHULT, Gunnar
• Granted Patent: US 7,829,831 B2
• Time in Patent Office: Days
• US Class Current: 250/205
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 2215/0503 Built-in units
• CPC Class Codes: H05B 41/325 by measuring the incident light

Abstract

A device includes a flash unit to generate light, and an optical sensor to receive the light from the flash unit, and generate a light intensity signal based on the received light. The device also includes a controller to generate a modified error signal based on the light intensity signal. The device further includes a control circuit to receive the modified error signal from the controller, receive an output voltage from a power source associated with the device, control the output voltage based on the modified error signal, and provide the controlled output voltage to the flash unit.

Claims

1. A method performed by a device, the method comprising:

generating light with a flash unit associated with the device;

receiving, directly from the flash unit, the generated light with an optical sensor associated with the device;

generating, with the optical sensor, a light intensity signal based on the received light received directly from the flash unit;

generating, with a controller associated with the device, a control signal based on the light intensity signal;

receiving, by a control circuit associated with the device, the control signal;

receiving, by the control circuit, an output voltage;

controlling, with the control circuit, the output voltage based on the control signal;

providing the controlled output voltage from the control circuit to the flash unit; and

controlling the light generated by the flash unit based on the controlled output voltage.

3. The method of claim 1, where the controller comprises a proportional-integral-derivative (PID) controller.

4. The method of claim 1, where the flash unit is one of:

integrated with the optical sensor;

or

located in a same package as the optical sensor.

5. The method of claim 1, where the device includes at least one of:

a radiotelephone;

a personal communications system (PCS) terminal;

a laptop;

a personal computer;

a camera;

a video camera with camera capabilities;

binoculars;

or

a telescope.

6. The method of claim 1, where the flash unit includes a plurality of light-emitting devices, and the method further comprises:

receiving, with the optical sensor, light directly from one of the plurality of light-emitting devices; and

generating, with the optical sensor, the light intensity signal based on the light directly received from one of the plurality of light-emitting devices.

7. The method of claim 6, where the light intensity signal is used to control the light generated by the plurality of light-emitting devices.

2. (canceled)

8. A device comprising:

a flash unit to generate light;

an optical sensor to;

receive the generated light directly from the flash unit, and

generate a light intensity signal based on the generated light received directly from the flash unit;

a controller to generate a modified error signal based on the light intensity signal; and

a control circuit to;

receive the modified error signal from the controller,

receive an output voltage from a power source associated with the device,

control the output voltage based on the modified error signal, and

provide the controlled output voltage to the flash unit,

where the flash unit adjusts an intensity of the light generated by the flash unit based on the provided controlled output voltage.

9. The device of claim 8, where the device includes at least one of:

a radiotelephone,

a personal communications system (PCS) terminal,

a laptop,

a personal computer,

a camera,

a video camera with camera capabilities,

binoculars, or

a telescope.

10. The device of claim 8, where the flash unit is further to:

generate light based on the controlled output voltage.

11. The device of claim 8, where the control circuit comprises a direct current to direct current (DC/DC) converter.

12. The device of claim 11, where the controller comprises a proportional-integral-derivative (PID) controller.

13. The device of claim 8, where the flash unit is one of:

integrated with the optical sensor, or

located in a same package as the optical sensor.

14. The device of claim 8, where the flash unit includes a plurality of light-emitting devices, and the optical sensor is further to:

receive light directly from one of the plurality of light-emitting devices, and

generate the light intensity signal based on the light received directly from one of the

plurality of light-emitting devices,

where the light intensity signal is used to control the light generated by the plurality of light-emitting devices.

16. The device of claim 8, where the flash unit comprises a flash light-emitting diode (LED).

17. The device of claim 8, where the control circuit comprises one of a digital circuit or an analog circuit.

18. The device of claim 8, where the optical sensor comprises a sensor that optically receives the light generated by the flash unit and is unaffected by ambient light.

15. (canceled)

19. (canceled)

20. A device comprising:

means for generating light;

means for receiving light directly from the means for generating light;

means for generating a light intensity signal based on the received light received directly from the means for generating light;

means for generating a control signal based on the light intensity signal;

means for receiving an output voltage;

means for controlling the output voltage based on the control signal; and

means for controlling the light generated by the means for generating light based on the controlled output voltage.

21. The device of claim 20, where the means for generating light comprises a plurality of light-emitting devices,

where the means for receiving light is to:

receive light directly from one of the plurality of light-emitting devices,

generate the light intensity signal based on the light received directly from one of the plurality of light-emitting devices, and

where the means for controlling the light, generated by the means for generating light, uses the light intensity signal to control the light generated by the plurality of light-emitting devices.

22. The device of claim 20, further comprising:

means for generating an error signal based on a negative value of the light intensity signal and a reference signal,

where the means for generating the control signal generates a modified error signal based on the error signal, and

where the means for controlling the output voltage controls the output voltage based on the modified error signal.

23. The device of claim 20, where the device includes at least one of:

a radiotelephone,

a personal communications system (PCS) terminal,

a laptop,

a personal computer,

a camera,

a video camera with camera capabilities,

binoculars, or

a telescope.