Colour temperature and colour location control for a light

• US 8,058,816 B2
• Filed: 03/30/2007
• Issued: 11/15/2011
• Est. Priority Date: 04/07/2006
• Status: Active Grant

• Current Assignee: LEDON Lighting GmbH (Zumtobel Group AG)
• Original Assignee: LEDON Lighting GmbH (Zumtobel Group AG)
• Inventors: Sejkora, Gunther
• Primary Examiner(s): Tan; Vibol
• Application Number:
  US12/296,149
• Publication Number:
  US 20090174332A1
• Time in Patent Office: 1,691 Days
• Field of Search: 315/152, 315/297, 315/291, 315/160, 313498-512, 362/84, 362/231, 362/287, 362/293, 362/296.1
• US Class Current: 315/291
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

The present invention relates to a method for providing control signals for a light whose color or color temperature is variable. The invention also relates to a corresponding control apparatus and a corresponding lighting system. In the method, a series of at least three color locations (F₁, F₂, F₃) is determined, which lie on a predetermined color change curve (K1) in a corresponding coordinate system. By way of example, the color change curve may be the Planck curve train or a straight line. The color locations (F₁, F₂, F₃) are in this case chosen such that the respectively corresponding colors have a color distance (d) which, at least approximately, is subjectively perceived as in each case being of the same magnitude. This makes it easier to adjust the light to give a specific desired light impression.

Claims

1. A method of providing control signals for a luminaire which can radiate light in different colours,

having the following steps:

a1) input of input quantities into an input unit of a control device, comprising a computation unit for determining a series of at least three colour locations, which identify three different colours, depending on the input quantities, the colour locations being chosen so that in a co-ordinate system which represents the latter, they are at least approximately on a specified colour change curve, and that between any two colours which are adjacent according to the colour change curve, at least approximately equally great colour distances are present, and for determining, for the luminaire, control signals using which the luminaire can be caused to radiate light in the at least three colours, and a transmission unit for transmitting the control signals to the luminaire, wherein the input quantities are two colour locations which differ from each other, and wherein the first colour location identifies a first colour and the second colour location identifies a second colour which differs from the first colour,

a2) depending on the first colour location and the second colour location—

subject to the two conditions i) and ii) below—

a colour location which is to be determined, and which identifies a further colour, is determined;

i) the colour location to be determined, in the co-ordinate system, together with the first and the second colour location, is at least approximately on a specified colour change curve, and

ii) the colour distance between the first and the second colour, or an integer multiple of this colour distance, at least approximately equals the colour distance between the first and the further colour or between the second and the further colour, and

b) on the basis of the determined colour location, a control signal which causes the luminaire to radiate light in the further colour corresponding to the determined colour location is generated.

2. A method according to claim 1,

wherein the specified colour change curve is the Planckian locus.

3. A method according to claim 1,

wherein the luminaire comprises three lamps, preferably LEDs or fluorescent lamps, which can emit light of different colours.

4. A method according to claim 1, wherein the specified colour change curve is a straight line.

5. A method according to claim 4,

wherein the luminaire comprises at least two lamps, preferably LEDs or fluorescent lamps, which can emit light of different colours.

6. A method according to claim 1,

wherein in a step, a series of at least three colour locations is defined, such that, for their three corresponding colours, between any two colours which are adjacent according to the colour change curve, at least approximately an equally great colour distance is present.

7. A method according to claim 6,

wherein the luminaire is controlled temporally so that the at least approximately equally great colour distances are passed through at essentially equal time intervals.

8. A method according to claim 1,

wherein, as the co-ordinate system, a co-ordinate system is chosen in which a geometrical distance between two colour locations at least approximately represents a measure for a specified colour distance.

9. A method according to claim 1,

wherein the representation of the CIE 1976 colour table is chosen as the co-ordinate system.

10. A method of providing control signals for a luminaire which can radiate light in different colours,

having the following steps:

a1) input of input quantities into an input unit of a control device, comprising a computation unit for determining a series of at least three colour locations, which identify three different colours, depending on the input quantities, the colour locations being chosen so that in a co-ordinate system which represents the latter, they are at least approximately on a specified colour change curve, and that between any two colours which are adjacent according to the colour change curve, at least approximately equally great colour distances are present, and for determining, for the luminaire, control signals using which the luminaire can be caused to radiate light in the at least three colours, and a transmission unit for transmitting the control signals to the luminaire, wherein the input quantities are one colour location and one colour distance, and wherein the first colour location identifies a first colour,

a2) depending on the colour location and the colour distance—

subject to the two conditions i) and ii) below—

a colour location which is to be determined, and which identifies a further colour, is determined;

i) the colour location to be determined, in the co-ordinate system , together with the first colour location, is at least approximately on a specified colour change curve, and

ii) the colour distance between the first and the further colour, at least approximately equals the specified colour distance or an integer multiple of it, and

b) on the basis of the determined colour location, a control signal which causes the luminaire to radiate light in the further colour corresponding to the determined colour location is generated.

11. A method of providing control signals for a luminaire whose colour temperature is changeable,

having the following steps:

input of input quantities into an input unit of a control device, comprising a computation unit to determine a series of at least three colour temperature values, depending on the input quantities, the colour temperature values being chosen so that they correspond to three colours in such a way that between any two adjacent colours, at least approximately equally great colour distances are present, and to determine, for the luminaire, control signals using which the luminaire can be caused to radiate light with the at least three colour temperature values, and a transmission unit to transmit the control signals to the luminaire, wherein the input quantities are two colour temperature values which differ from each other, and

determination of a colour temperature setpoint value depending on the two colour temperature values, the colour temperature setpoint value being chosen so that the colour distance between the two colours, which correspond to the specified colour temperature values, or an integer multiple of this colour distance, at least approximately equals the colour distance between the colour which corresponds to one of the two specified colour temperature values and the colour which corresponds to the colour temperature setpoint value to be determined.

13. A method according to claim 11,

wherein the luminaire comprises three lamps, which can emit light of different colours.

14. A method according to claim 13,

wherein the three lamps are LEDs or fluorescent lamps.

15. A method according to claim 11,

wherein, in a further step, a series of at least three colour temperature values is defined, such that, for their three corresponding colours, between any two adjacent colours at least approximately an equally great colour distance is present.

16. A method according to claim 11,

wherein to determine the relationship between two colour temperature values and the colour distance between the two colours corresponding to the two colour temperature values, with the aid of Planck'"'"'s radiation law and the sensitivities of the human eye to red, green and blue light, a co-ordinate system in which a geometrical distance between two colour locations at least approximately represents a measure of a specified colour distance is used.

17. A method according to claim 16, wherein the representation of the CIE 1976 colour table is chosen as the co-ordinate system.

12. A method of providing control signals for a luminaire whose colour temperature is changeable,

having the following steps:

input of input quantities into an input unit of a control device, comprising a computation unit to determine a series of at least three colour temperature values, depending on the input quantities, the colour temperature values being chosen so that they correspond to three colours in such a way that between any two adjacent colours, at least approximately equally great colour distances are present, and to determine, for the luminaire, control signals using which the luminaire can be caused to radiate light with the at least three colour temperature values, and

a transmission unit to transmit the control signals to the luminaire wherein the input quantities are one colour temperature value and one colour distance, and

determination of a colour temperature setpoint value depending on the colour temperature value and the colour distance, the colour temperature setpoint value being chosen so that the colour distance between the colour which corresponds to the specified colour temperature value and the colour which corresponds to the colour temperature setpoint value to be determined at least approximately equals the specified colour distance or an integer multiple of the specified colour distance.