US 7,173,384 B2 · Illumination device and control method

Abstract

A description is given of an illumination device which emits mixed-color light containing light of at least two different color channels (R, R1, G, G1, B, B1). The illumination device contains at least one primary light source (1) of a first color, the light of which forms a first color channel (R, R1, G, G1, B, B1), and at least one primary light source (1) of a second color, the light of which forms a second color channel (R, R1, G, G1, B, B1), at least one sensor device (3), which is positioned such that it can receive mixed-color light and is suitable for detecting brightness of light of a wavelength range comprising the color channels (R, R1, G, G1, B, B1) and which determines the brightnesses of the different color channels (R, R1, G, G1, B, B1) separately and repeatedly during operation. Furthermore, the illumination device contains an evaluation and control device (4), which evaluates the brightness values of the color channels (R, R1, G, G1, B, B1) and determines pulse-width-modulated electrical signals with a basic period (11) modified in such a way for the driving of the individual color channels (R, R1, G, G1, B, B1) in such a way that the color location of the mixed-color light lies within a predetermined region of the CIE standard chromaticity diagram. A method is also described for controlling such an illumination device.

Claims18

Dependent claims

An illumination device which emits mixed-color light during operation, said light containing light of at least two different color channels (R, R1, G, G1, B, B1), comprising:

at least one first primary light source (1) of a first color, the light of which forms a first color channel (R, R1, G, G1, B, B1);
at least one second primary light source (1) of a second color, the light of which forms a second color channel (R, R1, G, G1, B, B1);
at least one sensor device (3), which is positioned to receive mixed-color light and is suitable for detecting brightness of light of a continuous wavelength range comprising the first and second color channels (R, R1, G, G1, B, B1) and which determines brightness values of the first and second color channels (R, R1, G, G1, B, B1) separately and repeatedly during operation;
and
an evaluation and control device (4), which, during operation, evaluates the brightness values of the first and second color channels (R, R1, G, G1, B, B1) and determines pulse-width-modulated electrical signals with a basic period (11) modified in such a way for the driving of the first and second color channels (R, R1, G, G1, B, B1) that color location of the mixed-color light lies within a predetermined region of the CIE standard chromaticity diagram.

2 more elements

A method for controlling an illumination device which emits mixed-color light containing light of at least two different color channels (R, R1, G, G1, B, B1), in which each color channel (R, R1, G, G1, B, B1) is driven with a pulse-width-modulated electrical signal with a sequence of basic periods (11), comprising:

modifying the basic periods (11) of a pulse-width-modulated electrical signal such that the basic periods (11) contain a first time interval during which all of the color channels (R, R1, G, G1, B, B1) are turned on simultaneously;
modifying the basic periods (11) of a pulse-width-modulated electrical signal such that they contain at least one second time interval during which only one of the at least two color channels (R, R1, G, G1, B, B1) is turned on and the brightness of the turned-on color channel is in each case determined separately;
repeating the modified basic periods (11) to form an overall period (12);
and
after the overall period (12) has elapsed, comparing the ratio of the brightnesses of the individual color channels (R, R1, G, G1, B, B1), and setting the duty ratios of the respective modified pulse-width-modulated electrical signals such that the color location of the mixed-color light lies within a predetermined region of the CIE standard chromaticity diagram.

2 more elements

Dependencies are inferred from the claim text.

Illumination device and control method

Life of this patent

Illumination device and control method

Life of this patent

Abstract

Claims18