Illumination device

• US 20060082333A1
• Filed: 09/29/2005
• Published: 04/20/2006
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Laski, Joseph John
• Granted Patent: US 7,334,917 B2
• Time in Patent Office: Days
• US Class Current: 315/312
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]

Abstract

An illumination device comprising at least four luminous units (1, 2), the light emitted by at least two of the four luminous units (1, 2) being suitable for being mixed to form white light. Moreover, an apparatus (3) for dimming at least one of the four luminous units (1, 2) is provided. White light having a desired color temperature (CCT) and a high color rendering index can be generated by means of the illumination device.

Claims

1. An illumination device, having

at least four luminous units (1, 2), the light emitted by at least two of the four luminous units (1, 2) being suitable for being mixed to form white light, and

an apparatus (3) suitable for dimming at least one of the four luminous units (1, 2).

2. The illumination device as claimed in claim 1, in which at least one of the luminous units (1, 2) contains at least one of the following radiation-emitting components:

light-emitting diode, organic light-emitting diode, laser, electroluminescent film.

3. The illumination device as claimed in claim 1, in which the apparatus (3) is suitable for generating pulse-width-modulated signals.

4. The illumination device as claimed in claim 1, having a control apparatus (4) for driving the apparatus (3), by means of which a correlated color temperature (CCT) of the light emitted by the illumination device can be set in a defined manner.

5. The illumination device as claimed in claim 1, in which at least the light emitted by one of the luminous units (1, 2) is suitable for increasing the color rendering index of the light emitted by the illumination device.

6. The illumination device as claimed in claim 1, in which

at least one luminous unit is suitable for emitting light having a central wavelength of between 455 nm and 485 nm,

at least one luminous unit is suitable for emitting light having a central wavelength of between 512 nm and 538 nm,

at least one luminous unit is suitable for emitting light having a central wavelength of between 580 nm and 594 nm,

at least one luminous unit is suitable for emitting light having a central wavelength of between 608 nm and 626 nm.

11. The illumination device as claimed in claim 10, in which the apparatus (3) is suitable for generating pulse-width-modulated signals for the blue, yellow and red light-emitting diodes of the light-emitting diode module (1, 2) and the green light-emitting diodes emit light with maximum intensity independently of the position of the switches (41.48) of the control apparatus (4).

7. An illumination device, having

a first light-emitting diode module (1) comprising at least one light-emitting diode suitable for emitting light in the red spectral range, at least one light-emitting diode suitable for emitting light in the green spectral range, and at least one light-emitting diode suitable for emitting light in the blue spectral range,

a second light-emitting diode module (2) comprising at least one light-emitting diode suitable for emitting light in the yellow spectral range,

an apparatus (3) suitable for generating pulse-width-modulated signals for driving at least one portion of the light-emitting diodes, and

a control apparatus (4), by means of which at least one predefined correlated color temperature (CCT) of the light emitted by the illumination device can be set.

8. The illumination device as claimed in claim 7, in which

the control apparatus (4) comprises switches (41.48), and

each switch (41.48) is assigned a color temperature of the white light emitted by the illumination device in such a way that as a result of one of the switches being closed and the remaining switches being opened, white light having the color temperature assigned to the switch is emitted by the illumination device.

9. The illumination device as claimed in claim 7, in which the control apparatus (4) comprises a network of three times eight series circuits, each series circuit containing a potentiometer and a diode connected in series with the potentiometer.

10. The illumination device as claimed in claim 7, in which, depending on the state of the switches (41.48) of the control apparatus (4), voltages are present at control inputs (3b) of the apparatus (3) and the brightness of at least one portion of the light-emitting diodes of the light-emitting diode modules (1, 2) is dependent on said voltages.

12. The illumination device as claimed in claim 10, in which the green light-emitting diodes of the first light-emitting diode module (1) are directly connected to the current supply (5).

13. The illumination device as claimed in claim 7, in which, by means of the control apparatus (4), it is possible to choose at least between the following correlated color temperatures (CCT):

6500 K, 5500 K, 5000 K, 4100 K, 3500 K, 3000 K, 2800 K, 2500 K.

14. The illumination device as claimed in claim 7, in which each light-emitting diode module (1, 2) comprises ten or fewer than ten light-emitting diodes of the same color.