Lamps

• US 8,884,527 B2
• Filed: 10/16/2012
• Issued: 11/11/2014
• Est. Priority Date: 10/17/2011
• Status: Active Grant

• Current Assignee: Lextar Electronics Corporation
• Original Assignee: Lextar Electronics Corporation
• Inventors: Lin, Feng-Ling, Chen, Po-Shen, Chen, Hui-Ying, Chen, Chun-Kuang, Chen, Tung-Yu
• Primary Examiner(s): CRAWFORD, JASON
• Application Number:
  US13/653,015
• Publication Number:
  US 20130093331A1
• Time in Patent Office: 756 Days
• Field of Search: 315149-152, 315/291, 315/294, 315/297, 315/307
• US Class Current: 315/149
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

An embodiment of the invention provides a lamp comprising a control circuit and a light emitting device. The light emitting device comprises a plurality of light emitting units with different wavelengths. The control circuit calibrates a control signal according to an environment light to adjust a light spectrum of the light emitting device by controlling the luminance of each light emitting unit.

Claims

1. A lamp, comprising:

a light emitting device which comprises a plurality of light emitting units with different wavelengths; and

a control circuit which calibrates a control signal according to an environment light, to adjust a light spectrum of the light emitting device by controlling the luminance of each light emitting unit, wherein the control circuit further calibrates the control signal according to a photopic vision curve and a scotopic vision curve, wherein when the luminance of the environment light is reduced, the control circuit selects a second light emitting unit from the light emitting units according to a wavelength range and increases the luminance of the second light emitting unit and gradually reduces the luminance of the light emitting units except the second light emitting unit.

2. The lamp of claim 1, wherein the wavelength range is determined according to the scotopic vision curve.

3. The lamp of claim 2, wherein the wavelength range is between 450 nm and 530 nm.

4. The lamp of claim 3, wherein the center wavelength of the scotopic vision curve is 507 nm.

5. The lamp of claim 2, wherein when the second light emitting unit complies with the scotopic vision curve, a luminance increment of the red spectrum in the light emitting device is removed.

6. The lamp of claim 1, wherein the control circuit quickly increases the luminance of the light emitting unit with a red spectrum of the light emitting device at the beginning.

7. The lamp of claim 6, wherein the range of the red spectrum is between 600 nm and 680 nm.

8. The lamp of claim 1, wherein the control circuit controls the luminance of the light emitting units by adjusting the current value of a plurality of currents outputted to the light emitting units.

9. The lamp of claim 1, wherein the control circuit controls the luminance of the light emitting units by adjusting a plurality of duty cycles for outputting a plurality of driving signals of the light emitting units.

10. A lamp, comprising:

a light emitting device which comprises a green light emitting unit, a cyan light emitting unit and a red light emitting unit; and

a control circuit which adjusts the luminance of the green light emitting unit, the cyan light emitting unit and the red light emitting unit according to an environment light signal related to environment light, wherein when a luminance of the environment light is increased, the control circuit reduces a first luminance of the cyan light emitting unit and increases a second luminance of the green light emitting unit, and when the luminance of the environment light is reduced, the controls circuit increases the first luminance of the cyan light emitting unit and reduces the second luminance of the green light emitting unit, wherein when the luminance of the environment light is reduced, the control circuit gradually increases a third luminance of the red light emitting unit and then reduces the third of the red light emitting unit to an initial luminance after the first luminance of the cyan light emitting unit complies with a scotopic vision curve.

11. The lamp of claim 10, wherein the initial luminance refers to the luminance before adjustment of the red light emitting unit.

12. A lamp, comprising:

a light emitting device which comprises a plurality of light emitting units with different wavelengths; and

a control circuit which calibrates a control signal according to an environment light, to adjust a light spectrum of the light emitting device by controlling the luminance of each light emitting unit, wherein the control circuit further calibrates the control signal according to a photopic vision curve and a scotopic vision curve, wherein when a luminance of the environment light is increased, the control circuit selects a green light emitting unit from the light emitting units according to a wavelength range and increases the luminance of the green light emitting unit and the luminance of other light emitting units, wherein the luminance variation of the green light emitting unit is greater than the luminance variation of the other light emitting units.

13. The lamp of claim 12, wherein the wavelength range is determined according to the photopic vision curve.

14. The lamp of claim 13, wherein the wavelength range is between 530 nm and 590 nm.

15. The lamp of claim 14, wherein a center wavelength of the photopic vision curve is 555 nm.