Illumination device

• US 7,144,130 B2
• Filed: 06/08/2004
• Issued: 12/05/2006
• Est. Priority Date: 06/09/2003
• Status: Expired due to Fees

• Current Assignee: Schott Moritex Corporation
• Original Assignee: Moritex Corporation (Cognex Corporation)
• Inventors: Nakao, Hitoshi, Fukunaga, Yasuhiko, Toyota, Makoto
• Primary Examiner(s): Ward, John Anthony
• Assistant Examiner(s): MAKIYA, DAVID J
• Application Number:
  US10/862,377
• Publication Number:
  US 20040246742A1
• Time in Patent Office: 910 Days
• Field of Search: 362/230, 362/551, 362/552
• US Class Current: 362/230
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules

Abstract

An illumination apparatus for illumination of light by emitting light from LED for each of RGB colors capable of optionally setting a color temperature and controlling the brightness after the setting while maintaining the color temperature as it is, in which a light control circuit supplies a light control voltage for variably controlling the light quantity of the illumination light equally to each color setting circuit connected with LED of each color which is lit by a light quantity in proportion with a driving current and a color temperature setter of the color temperature setting circuit adjusts the light control voltage by a predetermined ratio to a control voltage, and a constant current circuit outputs a driving current in accordance with the control voltage to each LED for each of RGB colors.

Claims

1. An illumination apparatus that emits light of a particular color temperature by emitting light from a red LED, a green LED, and a blue LED, comprising:

a plurality of color temperature setting circuits, each color temperature setting circuit being connected to one of the red LED, the green LED, and the blue LED, each of the red LED, the green LED, and the blue LED being supplied with a driving current; and

a light control circuit that supplies a light control voltage to each color temperature setting circuit; and

a bundle of fibers, comprising a plurality of fibers which are each associated with one of the red LED, the green LED, and the blue LED, the bundle of fibers combining lights emitted by the red LED, the green LED and the blue LED, wherein each color temperature setting circuit comprises a color temperature setter that generates an adjusted control voltage from the light control voltage in accordance with a predetermined ratio, and a constant current circuit that outputs a driving current corresponding to the adjusted control voltage to a connected LED,

wherein each color temperature setting circuit comprises an internal power supply and a switch which alternately supplies the light control voltage and a voltage from the internal power supply to the color temperature setter.

3. The illumination apparatus according to claim 1, wherein the driving current supplied to each of the red LED, the green LED, and the blue LED is controlled by adjusting the predetermined ratio of a corresponding color temperature setter.

4. The illumination apparatus according to claim 1, wherein each color temperature setter comprises a variable resistor.

5. The illumination apparatus according to claim 1, wherein the color temperature of a combined light outputted by the bundle of fibers is controlled by adjusting a predetermined ratio of at least one color temperature setter, and the brightness of the combined light is controlled by adjusting the light control voltage.

6. The illumination apparatus according to claim 1, wherein, for each fiber of the bundle of fibers, one end of the fiber connects to one of the red LED, the green LED, and the blue LED, and the other end of the fiber is bundled with ends of the other fibers to combine the lights emitted by the red LED, the green LED and the blue LED.

2. An illumination apparatus that emits light of a particular color temperature by emitting light from a red LED, a green LED, and a blue LED, comprising:

a plurality of color temperature setting circuits, each color temperature setting circuit being connected to one of the red LED, the green LED, and the blue LED, each of the red LED, the green LED, and the blue LED being supplied with a driving current; and

a light control circuit that supplies a light control voltage to each color temperature setting circuit, wherein each color temperature setting circuit comprises a color temperature setter that generates an adjusted control voltage from the light control voltage in accordance with a predetermined ratio, and a constant current circuit that outputs a driving current corresponding to the adjusted control voltage to a connected LED,

wherein each color temperature setting circuit comprises an internal power supply and a switch which alternately supplies the light control voltage and a voltage from the internal power supply to the color temperature setter.

7. The illumination apparatus according to claim 2, wherein the driving current supplied to each of the red LED, the green LED, and the blue LED is controlled by adjusting the predetermined ratio of a corresponding color temperature setter.

8. The illumination apparatus according to claim 2, wherein each color temperature setter comprises a variable resistor.