Brightness controlled light source

• US 8,212,483 B2
• Filed: 06/12/2008
• Issued: 07/03/2012
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Reisch, Juergen
• Primary Examiner(s): Le, Tung X
• Application Number:
  US12/138,299
• Publication Number:
  US 20090309500A1
• Time in Patent Office: 1,482 Days
• Field of Search: 315/77, 315/82, 315149-158, 315/219, 315/224, 315/294, 315/307, 315/312
• US Class Current: 315/82
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A method and system is provided for automatic brightness control of a light source. The system includes at least one light sensor that operates in a different range of the light spectrum than the light spectrum generated by the controlled light source.

Claims

1. A light control system comprising:

a vehicle headlight configured to emit light in a visible range of a light spectrum;

a light sensor configured to operate in an ultraviolet range of the light spectrum, wherein the ultraviolet range of the light spectrum is different than the visible range of the light spectrum, and wherein the light sensor is substantially insensitive to the visible range of the light spectrum; and

a control logic coupled to the light sensor and the vehicle headlight, the light sensor configured to provide information to the control logic to control a brightness of the vehicle headlight.

2. The system according to claim 1, wherein the light sensor is configured to provide information to control the brightness of the vehicle headlight as a function of daylight intensity sensed by the light sensor.

3. The system according to claim 1, wherein the light sensor is configured to operate in the ultraviolet range of the light spectrum such that the controlled brightness of the vehicle headlight depends substantially on daylight incidence or on sunlight in a vicinity of the vehicle headlight.

4. The system according to claim 1, wherein the light sensor is configured to cause light intensity of the vehicle headlight to be regulated within a range from 0 to maximum and/or from a switched off status of the controlled vehicle headlight to a maximum light emission of the vehicle headlight.

5. The system according to claim 1, wherein the light sensor comprises an opto-electronic sensor.

6. The system according to claim 1, wherein the light sensor is configured to detect an ultraviolet portion of the light spectrum, the light sensor comprising active electronic elements that amplify a current generated in the light sensor.

7. The system according to claim 6, wherein the light sensor comprises an electronic wavelength filter that electronically selects the ultraviolet portion of the light spectrum.

8. The system according to claim 1, wherein the light control system comprises a programmable brightness control system.

9. The system according to claim 8, wherein the programmable brightness control system is programmable to regulate the brightness of the vehicle headlight as a function of ambient brightness of light in the ultraviolet range in the a vicinity of the controlled vehicle headlight.

10. The system according to claim 1, wherein the light sensor and the control logic are implemented in a single integrated circuit.

11. The system according to claim 10, wherein the integrated circuit includes functionality implemented in CoolMos technology.

12. The system according to claim 10, wherein the integrated circuit is integrated in the vehicle headlight, in a socket of the vehicle headlight, in a casing of the vehicle headlight and/or in a glass bulb of the vehicle headlight.

13. The system according to claim 1, further comprising an AC/DC rectifier or transformer and/or a voltage converter coupled between the light sensor and the vehicle headlight.

14. The system according to claim 1, further comprising an insulated gate bipolar transistor element for controlling or regulating current in a proportionate manner to the a light power to be emitted from the vehicle headlight, the insulated gate bipolar transistor element being coupled between the light sensor and the vehicle headlight.

15. The system according to claim 1, wherein a current supply for the light control system is provided by an interface parallel or coupled to a socket connection of the vehicle headlight.

16. The system according to claim 1, wherein the light control system is capable of implementing a power-saving mode and/or a low standby current mode.

17. The system according to claim 1, wherein the light sensor is arranged with an orientation to ambient light such that the light sensor is configured to substantially detect brightness of natural light in a vicinity of the vehicle headlight as a basis for regulating the brightness of the controlled vehicle headlight.

18. The system according to claim 1, wherein the vehicle headlight comprises a bulb, a light emitting diode, a fluorescent lamp, a quartz lamp, a low-energy light bulb or a dimmable energy saving lamp.

19. The system according to claim 1, wherein the vehicle headlight comprises a plurality of light sources.

20. A method for controlling a light source, the method comprising:

detecting brightness or intensity of daylight near a vehicle headlight by at least one light sensor that operates only in an ultraviolet range of light spectrum; and

regulating brightness of a visible range of the light spectrum of the vehicle headlight based on the brightness or intensity of the daylight detected near the vehicle headlight.

21. The method according to claim 20, wherein the at least one light sensor is substantially insensitive to light generated by the vehicle headlight.

22. The method according to claim 20, wherein the ultraviolet range of the light spectrum is detected by the at least one light sensor and utilized to regulate the brightness of the vehicle headlight.

23. The method according to claim 20, wherein regulating the brightness of the vehicle headlight comprises varying light intensity of the vehicle headlight within a range from 0 to maximum and/or from a switched off status of the vehicle headlight to a maximum light emission power of the vehicle headlight.

24. The method according to claim 20, wherein the brightness of the vehicle headlight is regulated substantially independent of self-generated ambient brightness and/or room brightness and independent of light generated by artificial light sources.

25. The method according to claim 20, wherein the light sensor operates in a range of 200 nm to 500 nm wavelength.

26. The method according to claim 20, wherein the brightness of the vehicle headlight is regulated on a linearly and/or on a logarithmically basis.

27. The method according to claim 20, wherein, the vehicle headlight requires alternating current and wherein opto-electronical sampling of the light sensor being performed during a voltage zero-crossing of a current supply to the vehicle headlight.

28. An integrated circuit comprising components of a control and/or regulatory system, the integrated circuit being arranged and adapted such that it can be used as a control and/or regulatory device for performing the method according to claim 20.

29. A light control system comprising:

a vehicle headlight configured to emit light in a visible range of a light spectrum and further configured not to emit light in an ultraviolet range of the light spectrum;

a light sensor configured to operate in the ultraviolet range of the light spectrum and further configured to not operate in the visible range of the light spectrum; and

a control logic coupled to the light sensor and the vehicle headlight, the light sensor configured to provide information to the control logic to control a brightness of the vehicle headlight.

30. The light control system according to claim 29, wherein the light sensor provides information to control the brightness of the vehicle headlight as a function of daylight intensity sensed by the light sensor.