Luminaire of variable color temperature for obtaining a blend color light of a desired color temperature from different emission-color light sources

• US 5,350,977 A
• Filed: 06/08/1993
• Issued: 09/27/1994
• Est. Priority Date: 06/15/1992
• Status: Expired due to Fees

• Current Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Inventors: Gotoh, Shigeo, Hamamoto, Katunobu
• Primary Examiner(s): Lee, Benny
• Assistant Examiner(s): Philogene, Haissa
• Application Number:
  US08/073,373
• Time in Patent Office: 476 Days
• Field of Search: 315/324, 315/291, 315/292, 315/293, 315/307, 315/316, 315/DIG. 4, 315/169.1, 362/231, 362/257, 358/17, 358/29 C, 358/93, 358/240
• US Class Current: 315/291
• CPC Class Codes: H05B 39/041 the light-intensity of the source H05B39/08 takes precedence
• CPC Class Codes: H05B 41/3921 with possibility of light intensity variations
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: Y10S 315/04 Dimming circuit for fluorescent lamps

Abstract

A luminaire of variable color temperature is arranged for emitting blended color light from luminaire section, with color temperature control signals so transmitted from control section to luminaire-lighting section as to substantially equalize respective differences in reciprocal color temperatures of respective two adjacent stages of the color temperature control signals, to thereby render blended state of emission colors to be variable and a dimming of the blended color light to be realized with the color temperature gradually varied in smooth manner.

Claims

1. A luminaire of variable color temperature for obtaining a blended color light of a desired color temperature from different emission-color light sources, comprising:

a luminaire section including a plurality of light sources of mutually different and respectively predetermined emission colors, and means for lighting said plurality of light sources respectively in said predetermined emission colors, for emitting a blended color light with said emission colors of said light sources blended; and

a control section for transmitting to said lighting means of said luminaire section color-temperature control signals for varying a state in which the emission colors are blended to vary said blended color light from one of a plurality of blended color lights to another, said color-temperature control signals representing respectively a color temperature of each light source desired for obtaining said predetermined emission color of each light source, and respective differences in values of the color temperatures when represented by the reciprocal color temperatures of respective two adjacent stages of said control signals in a desired variation range of the color temperature being substantially equalized at any level of said variation range.

2. The luminaire according to claim 1, wherein said control section comprises a memory means in which said differences in the reciprocal color temperature of respective said two adjacent stages are set to be close to a predetermined color temperature descriminating threshold.

3. The liminaire according to claim 1, wherein said control section comprises a memory means in which said differences in the reciprocal color temperatures of respective said two adjacent stages are set in a range of substantially 1.0-10.0 mrd.

4. The luminaire according to claim 1, wherein said control section comprises means for dimming respective said light sources at a dimming ratio variable at a variation width changeable in different groups.

5. The luminaire according to claim 1, wherein said control section comprises a dimming characteristic converting means for dimming respective said light sources at a dimming ratio variable with a variation width changeable to be narrower when the light sources are dimmed at a low level and to be wider when the light sources are dimmed at a high level.

6. The luminaire according to claim 5, wherein said dimming characteristic converting means executes an analog signal processing.

7. The luminaire according to claim 5, wherein said dimming characteristic converting means executes a digital signal processing.

8. The luminaire according to claim 1, wherein said light sources are fluorescent lamps.

9. The luminaire according to claim 1, wherein said light sources have said emission colors of more than three colors containing at least red, green and blue.

10. The luminaire according to claim 1, wherein said light sources have said emission colors of more than three colors and positioning in a zone surrounded by desired chromaticity coordiates of at least red, green and blue on a color temperature graph.

11. The luminaire according to claim 1, wherein said light sources have said emission colors of more than three colors, and said control section further comprises means for dimming said light sources, the light sources of at least one of said three emission colors being dimmed at a dimming ratio with variable difference width.

12. The luminaire according to claim 1, wherein said light sources have said emission colors of three colors including red, green and blue, and said control section further comprises means for dimming said light sources, the light sources of said blue emission color only being dimmed at a dimming ratio at variable difference width.

13. The luminaire according to claim 2, wherein said memory means sets said color temperature differences to be about 50K in a range of color temperatures of about 2,500-4,500K, to be about 150K in a range of about 4,500-7,000K and to be about 500K in a range of about 7,500-10,000K.

14. The luminaire according to claim 2, wherein said memory means sets a color temperature difference in accordance with dimming data set in adjacent ones of addresses housed in the memory means to be about 40K in a color temperature range of about 2,500-5,000K and to be about 6 mrd in said range of about 2,500-5,000K.