EP1886538A2

EP1886538A2 - Spotlight for shooting films and videos

Info

Publication number: EP1886538A2
Application number: EP06753169A
Authority: EP
Inventors: Regine KRÄMER
Original assignee: Arnold and Richter KG; Arnold and Richter Cine Technik GmbH and Co KG
Current assignee: Arnold and Richter KG; Arnold and Richter Cine Technik GmbH and Co KG
Priority date: 2005-05-11
Filing date: 2006-05-11
Publication date: 2008-02-13
Anticipated expiration: 2026-05-11
Also published as: DE102005022832A1; JP2008541361A; EP1886538B1; WO2006119750A3; US7744242B2; DE502006005854D1; US20090046453A1; JP4644280B2; WO2006119750A2

Abstract

The invention relates to a spotlight for shooting films and videos with light-emitting diodes (LED's) arranged on a light-emitting surface. According to the invention, at least three LED's (4; 5; 61 64) are provided, whereby different LED colors (R, G, A, B, Ye) are emitted by the color LED's (61 64), and light flux portions are provided for a color mixture, and of which at least one LED is a fluorescent LED (4). The invention also relates to a device (2), which controls the LED's (4; 5; 61 - 64) at least in groups and which serves to set the light flux portion emitted by the LED's (4; 5; 61 - 64). The invention further relates to a method for adjusting the color characteristics emitted by a spotlight of the aforementioned type.

Description

Headlamp for film and video recordings

description

The invention relates to a headlamp for film and video recordings arranged on a light-emitting surface light-emitting diodes and a method

There are known illumination headlights with light emitting diodes (LEDs), which are used for example as a camera attachment light for film and video cameras. Since the LEDs used for this purpose either have the color temperature "daylight white" or "warm white", stepless or exact switching on or switching from a warm white to a daylight white color temperature is not possible, and in both variants the color reproduction in film and video recordings is unsatisfactory ,

Typical film footage for movies such as "Cinema Color Negative Film" are optimized for daylight with a color temperature of 5600 K or incandescent light with a color temperature of 3200 K and achieve excellent color rendering characteristics with these light sources for illuminating a set For a set, these have to be adapted to the optimum color temperature of 3200 K or 5600 K and have a very good color rendering quality, usually the best color rendering level with a color rendering index of CRI> 90 ... 100 required.

However, as with the use of fluorescent lighting for film or video recordings, artificial light sources with non-continuous spectral characteristics can achieve these levels of color temperature and color rendering, yet still use filament or incandescent light when used for filming HMI lamps or daylight have a significant color cast. In this case, one speaks of an insufficient mixing light capability. This effect can also occur when using different colored LEDs in an LED headlight. For example, in a test with a color combination of 5600 K and a color rendering index of CRI = 96 optimized LED combination when shooting a massive reddish compared to HMI lamps was detected. Even tests with daylight white LEDs did not give satisfactory results in terms of mixed light capability.

From DE 102 33 050 A1 an LED-based light source for the production of white light is known which makes use of the principle of three-color mixing. To produce the white light, a mixture of the three primary colors red-green-blue (RGB) is performed, wherein in a housing at least one blue light-emitting LED, which is referred to as a transmission LED and directly used light primarily in the wavelength range of 470 to 490th nm, as well as another LED, which works with conversion and is accordingly called a conversion LED, which emits light primarily in the wavelength range of at most 465 nm. Both LEDs or one of a plurality of LED types constructed surface (array) is preceded by a common conversion surface of a potting or a glass plate with one or more phosphors, so that the phosphors completely convert the light of the conversion LED, the light of But let the transmission LED pass through unhindered.

Even with this light source optimal color reproduction for film and video recordings can not be guaranteed since, in particular, there is the danger of an overemphasis or suppression of color components and thus a falsification of the colors of an object illuminated by the light source. For this reason, such a light source is mainly used in the entertainment sector. In addition, the phosphor in the known light source by short-wave radiation of max. 465 nm excited, which disadvantages in terms of efficiency and life of the fluorescent LEDs are expected.

US 2004/0105261 A1 discloses a method and a device for emitting and modulating light with a predetermined light spectrum. The known lighting device has a plurality of groups of light-emitting devices, each group emitting a predetermined light spectrum and a control device controlling the energy supply to the individual light-emitting devices so that the total resulting radiation has the predetermined light spectrum. there can be set by combining daylight white and warm white LEDs and changing the intensities of any color temperature between the warm white and daylight white LEDs.

A disadvantage of these methods are also not optimal color reproduction in film and video recordings and the lack of ability to set a predetermined color temperature and a precise color location. Depending on the selection of the individual LEDs or groups of LEDs and the color temperature set in each case, it is to be expected that there will be considerable color deviations from Planck's curve, which can only be corrected by presetting corrective filters. In addition, the light output is not optimal in a warm white setting the combination of daylight white and warm white LEDs, as this relatively high conversion losses occur due to the secondary emission of the phosphor. Another disadvantage of this method is that to set a warm or daylight white color temperature, a large part of the LEDs of the other color temperature can not be used or only strongly dimmed and thus the utilization factor for the typically during film shooting color temperatures to 3200 K and 5600 K. only about 50%.

The object of the present invention is to provide a headlamp for film and video recordings with light-emitting diodes arranged on a light-emitting surface, which ensures a very good color rendering and homogeneous color mixing of the radiation emitted by LEDs of different colors, whose color properties are suitable both for film and video. and are optimized for video recordings and no color cast against other light sources, such as halogen lamps or daylight, and allows any adjustment of the color temperature or a color location with very good use of the LEDs used.

This object is achieved by a headlamp of the type mentioned above, the light-emitting surface has at least three LEDs that emit different LED colors and provide luminous flux components for color mixing, of which at least one LED consists of a fluorescent LED, and one with the LEDs at least in groups controlling device for adjusting the output of the LEDs luminous flux component per color. The solution according to the invention provides an LED headlamp for film and video recordings, in which a very good color reproduction is achieved by a suitable combination of differently colored LEDs and whose color properties are optimized both for film and for video recordings without a color cast with respect to recordings other sources of light, such as incandescent or daylight. The compilation and arrangement of the LEDs thereby allows a largely homogeneous color mixing of the radiation emitted by the different colored LEDs and by accurately controlling the different LED colors or groups of LED colors, the color temperature between about 2500 K and 7000 K converted or arbitrarily set or a deviating from the Planckian curve color location within the gamut of the LEDs used are arbitrarily set. When setting a warm white or daylight white color temperature of 3200 K or 5600 K, a very high degree of utilization of> 85% based on the total luminous flux of the LEDs used is achieved.

For the solution according to the invention, it was assumed that it is not sufficient for high-quality illumination for film recordings to optimize an artificial light source only for the color temperature and the color rendering index. In addition, it must be ensured that the spectral distribution with regard to the spectral sensitivity of the film materials used does not lead to any undesired color casts in comparison with incandescent lamp or HMI lamps. Thus, among other things, it is necessary to avoid or skilfully compensate for the maxima of the film sensitivity curves with spectral emission peaks of the light source.

The solution according to the invention is based on the consideration of using a suitable for film and video recordings LED headlamps at least three different colored LEDs, one of which is designed as a LED LED and either a white, especially daylight, neutral or Warm white color or a yellow and / or green color emitted. A yellow and / or green color emitting phosphor LED is also referred to below as "yellow-green phosphor LED" and preferably combined with at least one LED color "blue" emitting LED. The solutions described below show suitable LED combinations that, at the right color temperature and excellent color reproduction, simultaneously ensure full mixed light capability when used for film and video recordings.

This results in the combination of a white fluorescent LED or a yellow-green fluorescent LED with at least three monochrome LEDs, of which when using a yellow-green or warm white fluorescent LED at least one monochrome LED has the LED color "blue".

The combinations of a plurality of monochrome LEDs and a white phosphor LED or a yellow-green phosphor LED are preferably combined to form an LED module, and the light-emitting surface of the headlight is assembled from an array of LED modules.

One way to miniaturize and improve the color homogeneity of the individual LED modules is to at least partially offset the spatial separation of fluorescent LEDs and color LEDs. Accordingly, according to a further feature of the invention, the phosphor layer of the phosphor LED covers not only the phosphor LED, but also the adjacent to the chip of the phosphor LED chips of the color LEDs of the green to red wavelength range. In this case, the chip of the phosphor LED is arranged, for example, in the middle of an LED module. The phosphor layer covers a larger area compared to the size of the phosphor LED.

However, it is preferable that the blue color LED is not integrated under the phosphor layer of the yellow-green or white phosphor LED. The blue color LED is excluded from this integration because otherwise its radiation would excite the phosphor of the yellow-green or white phosphor LED to secondary emissions, so that the blue color LED's radiation is no longer independent of the yellow-green radiation or white fluorescent LED could be adjusted.

In contrast, the radiation of the green to red color LEDs does not stimulate the yellow-green phosphor of the yellow-green or white phosphor LED and can pass this without spectral change. This embodiment of the solution according to the invention makes it possible to accommodate the chips in a confined space, since the chips of the color LEDs can be placed very close to the chip of the fluorescent LED. On the other hand, however, miniaturization and the associated higher luminance of the individual LED modules ensure that the quality of beam shaping and color homogenization achieved by the optical elements following the radiation source is improved.

A further advantage consists in that part of the radiation emitted by the color LEDs is scattered by the phosphor layer of the phosphor LEDs, and thus the entire surface of the phosphor layer in the colors of the color LEDs illuminates, thereby additionally homogenizing the color mixture is improved.

When combining the color LEDs and the phosphor LEDs into one LED module, each LED color, for example, yellow-green, blue, or red, consists of one or more LED chips to provide the optimum luminous flux component for color mixing. The number of LED chips actually used in each LED module or in the array of LED modules for the light-emitting surface of the headlamp per color is based on the power and luminous efficacy of the monochrome LEDs and phosphor LEDs used. Since these can change over time due to the development of new LEDs, the number of LEDs required for each color is selected such that the brightness ratios listed below are set at full luminous flux output, while by reducing the partial luminous flux, in particular by dimming individual ones Color LEDs with a minimum of required LEDs the relevant color temperature range from approx. 2700 K to 6000 K with optimum color rendering and at the same time almost constant brightness can be set.

In a further embodiment of the inventive solution, a homogeneous color mixing of the different LEDs is achieved in that the different colored LEDs are spatially very closely arranged by chip-on-board technology in small modules, each module as the smallest and complete unit all required LED Colors and the number of LEDs used per color based on the chip size and the required partial luminous flux. Accordingly, for example, an LED module, a daylight white, warm white or yellow-green fluorescent LED and four each contain blue, green, amber and red color LED chips. In a preferred embodiment of the solution according to the invention, the LED modules each have at least five different LEDs, of which one LED as a yellow-green or white phosphor LED, an LED as a monochrome cyan or blue color LED, an LED as a monochrome green color LED and two LEDs are designed as different monochrome color LEDs with a red, orange, yellow-orange or yellow LED color.

In a first variant of the inventive solution, the LED modules have a yellow-green or white phosphor LED, a monochrome blue color LED with a peak wavelength of 430nm - 480nm, preferably 450nm - 480nm, a monochrome green color LED with a peak wavelength from 505nm - 535nm, a monochrome amber color LED with a peak wavelength of 610nm - 640nm and a monochrome red color LED with a peak wavelength of 630nm - 660nm.

In a second variant of the solution according to the invention, the LED modules have a yellow-green or white phosphor LED, a monochrome cyan color LED with a peak wavelength of 480 nm-515 nm, preferably 485 nm-515 nm, a monochrome green color LED with a peak wavelength from 505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm and a monochrome amber color LED with a peak wavelength of 610nm - 640nm.

In a third variant of the solution according to the invention, the LED modules have a yellow-green or white phosphor LED, a monochrome cyan color LED with a peak wavelength of 480 nm-515 nm, preferably 485 nm-515 nm, a monochrome green color LED a peak wavelength of 505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm, a monochrome amber color LED with a peak wavelength of 610nm - 640nm and a monochrome blue color LED with a peak wavelength of 430nm - 480nm, preferably 450nm - 480nm, on.

In a fourth variant of the solution according to the invention, the LED modules have a yellow-green or white phosphor LED, a monochrome cyan color LED with a peak wavelength of 480 nm-515 nm, preferably 485 nm-515 nm, a monochrome green color LED with a peak wavelength from 505nm - 535nm, a mόnochrom yellow color LED with a peak wavelength of 580nm - 610nm and a monochrome red color LED with a peak wavelength of 630nm - 660nm. In a fifth variant of the solution according to the invention, the LED modules have a yellow-green or white phosphor LED, a monochrome cyan color LED with a peak wavelength of 480 nm-515 nm, preferably 485 nm-515 nm, a monochrome green color LED with a peak wave length of 505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm, a monochrome red color LED with a peak wavelength of 630nm - 660nm and a monochrome blue color LED with a peak wavelength of 430nm - 480nm, preferably 450nm - 480nm, on.

In a sixth variant of the solution according to the invention, the LED modules have a yellow-green or white phosphor LED, a monochrome cyan color LED with a peak wavelength of 480 nm-515 nm, preferably 485 nm-515 nm, a monochrome green color LED with a peak wavelength from 505 - 535nm, a monochrome amber colored color LED with a peak wavelength of 610 - 640 nm and a monochrome red color LED with a peak wavelength of 630 - 660nm.

In a seventh variant of the solution according to the invention, the LED modules have a yellow-green or white phosphor LED, a monochrome cyan color LED with a peak wavelength of 480 nm-515 nm, preferably 485 nm-515 nm, a monochrome green color LED with a peak wavelength from 505nm - 535nm, a monochrome amber colored color LED with a peak wavelength of 610mn - 640nm, a monochrome red color LED with a peak wavelength of 630nm - 660nm and a monochrome blue color LED with a peak wavelength of 430nm - 480nm, preferably 450nm - 480nm, up.

In an eighth variant of the solution according to the invention, the LED modules have a yellow-green or white phosphor LED, a monochrome blue color LED with a peak wavelength of 430nm - 480nm, preferably 450nm - 480nm, a monochrome green color LED with a peak wavelength from 505nm to 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm and a monochrome red color LED with a peak wavelength of 630nm - 660nm. In a ninth variant of the solution according to the invention, the LED modules each have less than five different LEDs, namely a yellow-green or white phosphor LED, a monochrome blue color LED with a peak wavelength of 430nm - 480nm, preferably 450nm - 480nm , and a monochrome red color LED with a peak wavelength of 630nm - 660nm. The blue color LED may never be, the red color LED can optionally be arranged below the phosphor layer of the fluorescent LED.

Of course, in all variants, several color LEDs can be present in one LED module for each color. Also, multiple phosphor LEDs may be present in one LED module.

In order to set the optimum color characteristic for film and video recordings, the luminous flux component emitted by the individual color LEDs of an LED module is determined and the radiation intensity of the LEDs is adjusted continuously or at intervals in order to compensate for changing environmental conditions and aging effects of the modules. A control or regulating device provided for this purpose contains at least one measuring device, which is arranged between the LED board and the front side of the headlamp, preferably regulated at a constant temperature, which detects the radiation intensity of the LEDs and serves as color measuring device, RGB sensor, V (λ). Sensor or light sensor is formed. Conceivable and advantageous in this context may also be to use an external measuring device, which is arranged outside the area between the LED board and the front of the headlamp.

In an advantageous embodiment, the measuring device is formed by at least five light sensors of different spectral sensitivity in the visible wavelength range between 380 nm and 780 nm. The at least five light sensors can be optimized in narrow bandwidth by means of optical filters, such as dichroic filters, in their spectral sensitivity to the radiation emitted by the LEDs and aligned for the determination of the radiation components of the monochrome LEDs in their spectral sensitivity to the maxima of the monochrome LEDs, the spectral sensitivity of the light sensor for determining the radiation fraction of the white or the yellow-green phosphor LED has its maximum either in the range 530 ... 610 nm or in the range 650 ... 750 nm. In the case of an LED combination without monochrome blue LEDs, the maximum of the spectral sensitivity of the light sensor can be used for Mood of the radiation component of the white or the yellow-green fluorescent LED alternatively in the wavelength range 430 ... 490 nm. Advantage of this arrangement is that from the signals of the sensors directly and simultaneously the luminous flux components of all involved LED colors can be determined and, if necessary, the intensity of the LEDs can be corrected to track eg thermally induced brightness or color changes. In the case of deviations from the predetermined target color location, the color location can then be readjusted immediately, continuously and without any disturbance for the user or for the camera. A warning to the user can thus be omitted, and a determination of the luminous flux components in a separate step is not required.

In one embodiment of the invention, a representative portion of each LED color is coupled into the photosensitive surface of the measuring device, in particular one in front of an array of e.g. Side-mounted LED light guide plate mixes the light, homogenized and let emerge evenly upwards. Through a small opening in the outer circumferential mirroring of the light guide plate, a representative portion of each LED color is coupled into the measuring device.

In an alternative embodiment, a monitor LED module arranged at a thermally representative point of the array of LED modules is used to illuminate the measuring receiver and a part of the radiation emitted by the LEDs is coupled into the measuring device by means of a light guide.

In a further alternative embodiment, a monitor LED module which is likewise arranged at a thermally representative point of the array of LED modules is used for the indirect illumination of the measuring receiver. The monitor LED module illuminates a diffuser plate mounted over the monitor LED module, which is mirrored up to eliminate incident ambient light for the measurement. The sensor is located directly next to the monitor LED module and detects the reflected light from the diffuser plate. In order to avoid the detection of incident on the side of the sensor ambient light, the sensor can be housed either in an example annular tube whose aperture is matched to the size and spacing of the diffuser plate. Or the diffuser plate is located together with the sensor within a mounted over the monitor LED module measuring capsule, which is preferably light-tight and inside white or mirrored. Furthermore, the spectral sensitivity of color sensors used in the measuring device can be adjusted by means of interference filters, wherein the aperture of the color sensors should typically be limited to a small aperture smaller than 10 ° in order to minimize color errors due to obliquely incident light.

The measurement of the individual LED colors can be triggered manually and indicate a visual and / or acoustic signal device, the deviation of the current setting of a predetermined target value.

Preferably, the desired color temperature, the desired color location, a color correction that emulates pre-set color correction filters, and / or a light color that emulates color filters or a light source are input by means of a user interface.

In a further advantageous embodiment of the headlamp is designed so that in a dimming mode, the color temperature is automatically adjusted and tracked depending on the brightness of the headlamp. For example, the dimple of an incandescent lamp, the color temperature of which changes with the brightness, can be reproduced by simultaneously adjusting the color temperature as the brightness of the spotlight changes, so that a brightness-color temperature profile corresponding to the dimming characteristic of an incandescent lamp is achieved is obtained.

Furthermore, it is conceivable and advantageous to design the headlight so that any selected by a user light color and / or light source can be adjusted. In this case, the light source to be imitated can be in particular a fluorescent lamp. By way of example, a user can then specify the light color 842 of a fluorescent lamp with a color temperature of 4200 K and a color rendering index CRI greater than 80 and reproduce it by the headlight in such a way that color casts are minimized during film and video recordings. This can be expedient in particular when using the headlamp for recording in buildings equipped with fluorescent lamps, for example as a report light and facilitates the handling and operability of the headlamp for a user.

In order to achieve optimum color characteristics for film and video recordings on a headlamp with the characteristics mentioned above, the luminous flux component emitted by the individual LEDs of an LED module is set with the following method steps. A method for adjusting the output of a headlight optimal color characteristic is characterized in that after switching on the headlamp, the maximum available radiation content of the LED colors and during operation of the headlamp from time to time, the current RGB or intensity values LED colors are measured and the radiation intensity of the LED colors is readjusted taking into account the current RGB or intensity values determined for each LED color in order to compensate for temperature and aging effects.

The current color location is preferably calculated from the current RGB or intensity values of the total radiation of the LED colors (R, G, A, B, Ye) and, in the case of deviations from the target color location, the current RGB or intensity values of the individual LED colors (R, G, A, B, Ye). The radiation intensity of the LED colors (R, G, A, B, Ye) is then readjusted taking into account the current RGB or intensity values determined for each LED color (R, G, A, B, Ye).

In a first alternative, the measurement of the current RGB or intensity values of the LED colors during operation can be achieved by briefly activating the individual LED colors and measuring the RGB or intensity values.

In a second alternative, successively two or a maximum of three LED colors are activated and measured together, whereby the intensities of the individual LED colors are calculated from the measured RGB value.

In a third alternative, the total radiation is first measured and then each individual LED color is turned off in turn and the RGB or intensity value of the remaining LED colors is measured, and the RGB or intensity values of the respectively switched-off LED color are determined by subtraction.

The triggering of the measurement and subsequent control of the LED intensity ratios can also take place in fixed, short intervals in configurations in which the radiation of a monitor LED module is detected by a measuring device associated with this module, if only the LED colors of the Monitor LED module is briefly switched on and off and the contribution of the monitor LED module to the overall brightness is less than 1%. In this case occur through the measurement and control cycles No disturbing brightness or color variations during movie or video recording.

Finally, in a fourth alternative, the radiation components of the LED colors are determined by measuring the total radiation of all LED colors with light sensors of different spectral sensitivity. The prerequisite for this is that the number of light sensors corresponds to the number of LED colors used. Advantage of this variant is that no additional, the lighting operation disturbing operation for detecting the radiation components is required, but the radiation components can be determined continuously during operation of the headlamp.

Based on embodiments shown in the drawing, the basic structure of the LED headlamp according to the invention, the setting of Farbcharakte- ristika and color temperatures and the control of the color intensities in the operation of the LED headlamp will be explained in more detail. Show it:

1 is a schematic view of one of an array of controllable LED

Modules composite light-emitting surface of a headlamp with measuring device;

FIG. 2 shows a schematic plan view of an LED module with a yellow-green or white phosphor LED whose phosphor layer covers a plurality of color LEDs; FIG.

3 shows a section through the LED module according to FIG. 2 along the line III-III;

4 is a schematic plan view of an LED module with a yellow-green or white phosphor LED whose phosphor layer is limited to the phosphor LED and does not cover adjacent color LEDs; ;

5 shows a section through the LED module according to FIG. 4 along the line V-V;

6 shows the relative wavelength spectra for blue color LEDs, green color

LEDs, amber or amber color LEDs and red color LEDs, as well as yellow-green fluorescent LEDs; 7-8 show the relative wavelength spectra of optimized LED combinations for film and video recordings with a warm white or daylight white color temperature;

9A shows a section through an LED headlamp with a measuring device in which light emitted by side emitting LEDs is mixed by a light guide plate;

Fig. 9B is a section through the LED headlamp of Fig. 9A taken along the line A-B;

10A-1OC is a flow chart for color adjustment and color control of an LED headlamp;

FIGS. 11-13 are flow diagrams for different variants of the intensity measurement of the

LEDs;

FIG. 14 is a flowchart for determining and calibrating color correction factors; FIG.

FIG. 15 shows a flow chart for determining and calibrating brightness characteristics; FIG.

Fig. 16 is a flowchart for emulating color filters;

17A shows a first embodiment of an LED headlight with measuring device in plan view;

Fig. 17B is a section through the LED headlamp of Fig. 17A taken along the line A-B;

18A shows a second embodiment of an LED headlight with measuring device in plan view;

Fig. 18B is a section through the LED headlamp of Fig. 18A taken along the line

FROM; 19A shows a third embodiment of an LED headlamp with measuring device in plan view;

Fig. 19B is a section through the LED headlight of Fig. 19A taken along the line

FROM;

2OA a fourth embodiment of an LED headlight with measuring device in plan view;

Fig. 2OB is a section through the LED headlight of Fig. 2OA along the line

FROM;

21 A shows a fifth exemplary embodiment of an LED headlight with a measuring device in plan view;

Fig. 21 B is a section through the LED headlight of Fig. 21 A along the line

FROM.

FIG. 22 shows the relative wavelength spectrums for blue color LEDs, red color LEDs and yellow-green phosphor LEDs; FIG.

FIGS. 23-24 show the relative wavelength spectra of optimized LED combinations for film and video recordings with a warm-white or daylight-white color temperature;

Fig. 25 shows the relative wavelength spectra for daylight white and warm white

Fluorescent LEDs as well as blue, green, yellow and red color LEDs;

Fig. 26 shows the Gamut of the headlamp for two different combinations of LEDs and

27 shows the dimming characteristic representing color temperature brightness

Course of a lightbulb. Fig. 1 shows a schematic plan view of the light-emitting surface or LED board 1 of a headlamp, which contains an array of LED modules 3 in rows and columns, which are connected individually or in groups with a control device 2, for example, the Individual LED modules 3 or groups of LED modules supplied electrical power varies. This can be done by varying the current supplied to the LED modules by means of pulse width modulation (frequency> 10 kHz to avoid exposure fluctuations in high speed recordings) or by changing the DC current intensity by changing resistance values or the like.

For detecting the luminous flux component emitted by the LED modules 3, a measuring device 7 with a photosensitive surface is provided, into which a representative portion of each LED color is coupled. For this purpose, the measuring device 7 is connected for example via a thin optical fiber with a mirrored up white diffuser plate, which is arranged on a monitor LED module at a thermally representative point of the LED modules. The diffuser plate receives radiation from each LED color and couples it into the light guide. A schematic section through a corresponding arrangement of a light guide 8 or alternative arrangements of the sensor without using a light guide are shown in FIGS. 9a, 9b and FIGS. 17a to 21b.

A measurement of the emitted overall color of the LED modules 3 takes place either continuously or at predetermined time intervals in order to continuously take into account a change in environmental parameters such as the ambient temperature and aging-related changes in the LED modules 3. If deviations from the set target color location are detected, the individual intensities of the LED colors of the LED modules can be measured either at predetermined time intervals or triggered manually and the color readjusted.

2 and 4 is a schematic plan view of different LED modules 3 and 3 ¹ and in FIGS. 3 and 5 is a section through the LED modules 3 and 3 'according to FIGS. 2 and 4 along the line IM-. III and VV shown.

The LED module 3 shown in a schematic plan view in FIG. 2 in the center contains a chip 40 of a yellow-green or white phosphor LED 4, around which several

Are arranged color LEDs 61 to 64, of which six color LEDs 62 to 64 of the Wei- lenlängen green to red around the chip 40 of the yellow-green or white fluorescent LED 4 are grouped. You can do this, but do not have to be directly adjacent to the chip 40. The phosphor layer 41 of the yellow-green or white phosphor LED 4 covers both the chip 40 of the yellow-green or white phosphor LED 4 and the color LEDs 62 to 64. Outside the phosphor layer 41 are more, exclusively blue or cyan color LEDs 61 so that their radiation, the phosphor layer 41 can not stimulate secondary emissions and thus the radiation of the blue or cyan color LED 61 regardless of the radiation of the phosphor LED 4 and the radiation of the colored LEDs 62 to 64 are set can.

For operation, the following is noted. The phosphor LED 4 consists of a blue LED chip 40, which is covered by the phosphor layer 41. The blue radiation emitted by the LED chip 40 excites the phosphor to longer wavelength (e.g., yellowish green) secondary emission. The overall color of the phosphor LED 4 is the mixed color of the blue light component which passes unchanged through the phosphor and the color of the light converted to longer wavelength radiation. The color location (standard color value components x, y) of the light emitted by the phosphor LED 4 can be varied depending on the choice of the phosphor material and its layer thickness and is located in the standard color chart on the connecting line between the two color locations of the blue primary radiation and the secondary radiation of the phosphor ,

As the phosphor material, for example, phosphorus or a phosphor mixture having a yellow or yellow-green coloration can be used. The color locus and the color temperature of the phosphor LED 4 can vary depending on the layer thickness of the applied phosphor layer 41 phosphorus or phosphor mixture of yellow, yellow-green, warm white on neutral white to daylight white with a color temperature of 50000K.

Depending on the applied phosphor layer thus a phosphor LED 4 with a color point and a color temperature between yellow and daylight white can be produced and used for the headlight. Such a luminous material LED is referred to herein generally as yellow-green or white luminous LED 4.

The spectral radiation components of the light emitted by the green, yellow, amber and / or red LEDs 62-64 lie above the excitation spectrum of the light source

Phosphorus and are therefore not absorbed by the phosphor and in converted longer-wavelength radiation. The radiation of these LEDs is thus not spectrally changed by the phosphor. Only in the case of green LEDs is a small proportion of the short-wave spectrum converted by the phosphor into longer-wave (yellow-green) radiation. Since the converted content is favorable to the spectral light sensitivity curve of the human eye, this effect slightly increases the luminous efficacy of the green LEDs, with no negative effects such as deterioration of color reproduction. Green color LEDs can thus also be arranged under the phosphor layer.

Although the color LEDs 62-64 are thus under the phosphor layer, they are not fluorescent LEDs but color LEDs because of their quasi-unchanged, narrow-band LED spectrum.

In contrast, the radiation emitted by the blue or cyan LEDs 61 still falls in their spectral composition into the excitation spectrum of yellow-green phosphors. Therefore, these color LEDs can not be arranged under the phosphor layer, since their radiation would be changed too much spectrally by the phosphor. Depending on the spatial arrangement of the blue or cyan chips 61, a negligible proportion of luminous flux exiting from the side of the chip may eventually strike the phosphor layer and be converted into longer-wave, yellow-green radiation (cf Fig. 6). However, this effect is connected for the same reasons as for the green LED with no disadvantages for efficiency or color quality of the total radiation.

In an alternative embodiment of the module 3 'according to FIGS. 4 and 5, the chip 40 of a yellow-green or white phosphor LED 4 is likewise arranged centrally and surrounded by a plurality of color LEDs 61-64. In this case, as well as the blue or cyan LEDs 61, the further color LEDs 62-64 are not covered by the phosphor layer 41 of the phosphor LED; this extends alone over the chip 40. In order to effect a precollimation of the light emitted by the LEDs, the individual LEDs can be embedded in microreflectors, also called "cups" or "cavities", which are preferably silvered, in order to reduce light losses through absorption to minimize.

The use of four differently colored color LEDs 61-64 in FIGS. 2 and 4 is only to be understood as an example; It is also possible to use a different number of different LEDs and / or to arrange them in a different way be. In a preferred embodiment, four blue color LEDs, four green color LEDs, two amber color LEDs and six red color LEDs are provided in order to arrange a central phosphor LED of an edge length of, for example, 1 mm. The green, amber and red color LEDs are distributed as uniformly as possible around the central phosphor LED, for example by arranging two concentric circles around the phosphor LED. Other colors can be used, but always the blue or cyan LED 61 is disposed outside the phosphor layer of the phosphor LED.

6 shows the wavelength spectrums for blue color LEDs 61 (B), green color LEDs 62 (G), amber or amber color LEDs 63 (A) and red color LEDs 64 (R) and for a yellow color LED. green fluorescent LED (Y) of an LED module and FIGS. 7 and 8 wavelength spectra for two optimized LED combinations, in which the full mixed light capability when used for film at a suitable warm or daylight white color temperature of the total radiation and excellent color rendering - And video recordings is guaranteed. It can be seen in the spectrum of the blue LED that a small proportion of luminous flux is converted by the adjacent phosphor into longer-wave radiation.

In two embodiments, the aforementioned LED colors are used in combination with a yellow-green phosphor LED whose peak wavelengths according to FIG. 6 are at the following wavelengths λ:

Peak wavelength λ color LED (nm)

Blue 461

Green 522

Amber 631

Red 646

Fluorescent LED

Yellow-green 563

In the two embodiments, there are two LED combinations for the settings "Tungsten" and "daylight", the optimized LED combinations the aforementioned LED colors blue, green, amber, red and a yellow-green fluorescent LED contain. An optimized Tungsten and Daylight LED module for film and video is composed of the following luminous flux components of the LED colors listed above and their peak wavelengths. This LED combination ensures a high luminous flux utilization factor of> 85% for the tungsten or daylight settings.

LED color Tungsten daylight

Blue 3.4% 10.5%

Green 0.2% 10.4%

Amber 7.4% 5.9%

Red 4.1% 0.0%

Yellow-green 84.8% 73.2%

Total 100.0% 100.0%

This results in a color temperature of 5732 K with a color rendering index CRI of 93 for the setting "daylight" whose wavelength distribution is shown in FIG. 7, and a color temperature of 3215 K with a color rendering index CRI of 96 for the setting "Tungsten". , whose wavelength distribution is shown in Fig. 8.

From the color temperature, the color rendering index CRI, the spectral radiation distribution of the light source, the spectral sensitivity functions of "Tungsten" or "daylight" sensitized color negative and color positive films in conjunction with a xenon lamp as a projection light source, an empirical evaluation variable of the mixed light capability is determined, both embodiments as very suitable for FiIm- and video recordings.

Fig. 25 shows the wavelength spectrums for blue color LEDs 61 (B), green color LEDs 62 (G), yellow color LEDs (Ye) and red color LEDs 64 (R) of an LED module and for a daylight white phosphor LED 4 (DL) and a warm white fluorescent LED 4 (WW), which can be combined in a further embodiment in an LED module, wherein either a daylight white or a warm white fluorescent LED with the color LEDs together in one LED Module is arranged. In four embodiments, the above-mentioned LED colors are used in combination with a daylight white (DL) phosphor LED and a warm white (WW) phosphor LED, respectively, whose peak wavelengths are λ at the following wavelengths (as shown in FIG. LEDs are indicated instead of the peak wavelengths the most similar to the fluorescent LEDs color temperatures):

Peak wavelength λ (nm)

Color LED

Blue 461

Green 522

Yellow 594

Red 646

Fluorescent LED Most similar color temperature (Kelvin)

Daylight white 5370

Warm white 3170

In the embodiments described below are two LED combinations for the settings "warm white" and "daylight", the optimized LED combinations, the above-mentioned LED colors blue, green, yellow, red and a daylight white or a warm white Fluorescent LED included.

An LED module optimized for film and video recordings for the "warm white" and "daylight" settings is then composed of the following luminous flux components of the LED colors specified above and their peak wavelengths:

When using a daylight white fluorescent LED:

Luminous flux portions

LED color warm white daylight white

BLUE 0% 1, 3%

Daylight white 45% 83%

GREEN 23% 10%

YELLOW 19% 1, 7%

RED 14% 4%

Total 700% 100%

This results in the setting "warm white" a color temperature of 3211 K with a color rendering index CRI of 92 and very good mixed light capability with incandescent lamps for film or video recordings and in the setting "daylight white" a color temperature of 5800 K with a color rendering index CRI of 93 and also very good mixed light capability with daylight or HMI light for film or video recordings.

When using a warm white fluorescent LED:

Luminous flux portions

LED color warm white daylight white

BLUE 1.2% 4.2%

GREEN 21% 23%

YELLOW 12.3% 5.8%

RED 10.5% 3% warm white 55% 64%

Sum 100% 100%

This results in the setting "warm white" a color temperature of 3198 K with a color rendering index CRI of 95 and very good mixed light capability and in the setting "daylight white" a color temperature of 5800 K with a color rendering index CRI of 94 and also very good mixed light.

The use of the LEDs with the wavelength spectra shown in FIG. 25 in combination in an LED module offers the advantage that a large gamut results, within which the color location of the LED modules can be set. This is illustrated in FIG. 26 which illustrates the gamut Ga1 of an LED module having a combination of blue, green, yellow and red color LEDs and a warm white or daylight white phosphor LED and the gamut Ga2 of an LED module having a combination of blue, green, amber and red color LEDs and a warm white or daylight white fluorescent LED. An essential advantage of the enlarged gamut Ga1 is that the gamut Ga1 completely covers the Planck ^'locus P for the setting very low color temperatures below 2000K and this allows the generation of white light with very good color rendering properties with a very good mixing of light ability.

That by means of the headlight, the entire Planck ^' s curve P can be reproduced, can be used for example for the emulation of the dimming characteristic of an incandescent lamp ("Tungsten") whose color temperature, as shown in Fig. 27, depends on the brightness (luminance) and, in particular at low brightness, assumes values below 2000 K. In order to emulate the light of a dimmed incandescent lamp, it is then possible to use an LED module with a combination of blue, green and blue LEDs. ner, yellow and red color LED and a warm white or daylight white or yellow-green fluorescent LED and using the large Gamut Ga1 the corresponding low brightness of the dimmed light bulb corresponding low color temperature are set.

It is also conceivable in this context to emulate the dimming curve of an incandescent lamp or another emulated lamp in a dimming mode of the headlamp by adjusting the color temperature of the headlamp in accordance with the dimming characteristic of the incandescent lamp or of the other lamp when the brightness is varied.

Taking advantage of the large gamut Ga1, it is also conceivable and advantageous to design the headlight in such a way that any light color and / or light source selected by a user can be adjusted. For example, a user can then specify the light color 842 of a fluorescent lamp with a color temperature of 4200 K and a color rendering index CRI greater than 80 and replicate it by the headlight in such a way that optimum mixed light capability is achieved for video and video recordings, thus color castings for film. and video recordings are minimized in order to be used, for example, as an easy-to-use reportage light in buildings.

FIG. 22 shows the wavelength spectra used for a further embodiment for blue color LEDs 61 (B), red color LEDs 64 (R) and for a yellow-green phosphor LED (Y) of an LED module and FIG. 23 and 24 wavelength spectra for two optimized LED combinations.

In two embodiments, the above-mentioned LED colors are used in combination with a yellow-green phosphor LED whose peak wavelengths according to FIG. 22 are at the following wavelengths λ:

Color LED peak wavelength λ (nm)

Blue 464

Red 646

Fluorescent LED

Yellow-green 562 In the two embodiments, there are two LED combinations for the settings "warm white" and "daylight white", the optimized LED combinations containing the aforementioned LED colors blue, red and a yellow-green fluorescent LED.

An LED module optimized for film and video recordings for the "warm white" and "daylight white" settings consists of the following luminous flux components of the LED colors specified above and their peak wavelengths:

LED color warm white daylight

Blue 2.9% 8.1%

Red 7.9% 1.8%

Yellow-green 89.2% 90.1%

Total 100.0% 100.0%

The following results can be achieved: for a warm white setting, a color temperature CCT = 3224 K with a color rendering index CRI = 93 and a very good mixed light capability; in a daylight white setting a color temperature CCT = 5470 K with a color rendering index CRI = 87 and a good mixed light capability. The wavelength distribution of the setting "daylight" is shown in FIG. 23 and the wavelength distribution of the setting "warm white" in FIG. 24.

The embodiment of FIGS. 22 to 24 has the advantage of a simple design, since it consists of only 3 LED colors (yellow-green phosphor LED, blue and red). With low compromises for the daylight-white setting in the color rendering index (87 instead of 90) and only good instead of very good mixed light capability, it represents a very simple and thus more cost-effective system as a triple combination.

17a to 21b show LED headlights with possible positioning of the light sensor (light sensor, V (λ) sensor, RGB sensor or colorimeter).

The beam shaping takes place, for example, by means of micro-optical elements such as micro-optically structured plates for Softlight headlamps or lenses for spotlight headlamps, optionally in conjunction with microreflectors in which the LEDs are embedded. Further features of the headlamp may be that the color is measured online with a colorimeter and readjusted to compensate for thermal and aging effects.

A control device provided for this purpose contains at least one preferably constant temperature controlled measuring device 7, which receives light from a white diffuser plate 9, which is arranged between the light-emitting surface and the front or rear of the headlamp, and for example from the LEDs of one or two monitor LED modules, which are located at a thermally representative place, is illuminated. To turn off incident ambient light for the measurement, the diffuser plate 9 is mirrored up. The incident on the diffuser plate 9 light is then forwarded to the measuring device 7, which may be formed, for example, as a colorimeter, RGB sensor, V (λ) sensor or light sensor.

17a, 17b of one of the LED modules 3 arranged on the LED circuit board 1 is provided as monitor LED module 3 ^" .The diffuser plate 9 is arranged on the underside of a pane 10. It has a mirror coating 91 is turned off both upwards and sideways by means of the reflective coating 91. The diffuser plate 9 is coupled to a light guide 8 ^' , which is connected to the measuring device 7, which in the illustrated exemplary embodiment is located in an edge region of FIG The printed circuit board 10 is preferably designed as a transparent pane or as a diffusing screen and may have a microstructure for beam shaping of the light emitted by the LED modules 3. The diffuser plate 9 is made, for example, from PTFE.

The 3 ^'light emitted from the monitor LED module illuminates the diffuser plate 9 and is directed by the latter by means of the light guide ^8' on the measuring device 7. The mirror coating 91 prevents incident ambient light is considered in the measurement.

Two monitor LED modules 3 "are provided in the exemplary embodiment of Figures 18a, 18b. The measuring device 7 is located between these monitor LED modules 3 ^" on the LED board 1. The diffuser plate 9 is again located on the underside of a Cover or lens 10 and has adjacent to the disc 10 a reflective coating 91. In this embodiment, that of the monitor LED modules 3 " radiated light from the diffuser plate 9 is reflected and detected directly by the measuring device 7. In this case, can be located above the measuring device 7 in the direction of the diffuser plate 9 open housing for Aperturanpassung. The height of such a housing is designed so that the aperture of the measuring device or the sensor 7 is matched to the diffuser plate 9 and laterally incident light is shaded.

In the embodiment of Figures 19a, 19b, similar to the exemplary embodiments of Figures 18a, 18b, the measuring device 7 (preferably designed as a sensor chip) is arranged next to a monitor LED module 3 ^" on the LED board 1. The measuring device 7 becomes direct The diffuser plate 9 is located in a measuring window capsule 11, which is preferably designed to be light-tight and, for this purpose, is white or mirrored, for example, inside the diffuser plate The sensor window 7 is placed over the monitor LED module 3 "and the measuring device 7 on the LED board 1.

In the embodiment of FIGS. 20a, 20b, a monitor LED module 3 "is located on a thermally representative point on the rear side of the LED board 1. In this embodiment, the measuring device 7 is located in a measuring window capsule 11 ', which is above - Over the monitor LED module 3 ^"is arranged. The monitor LED module 3 "directly illuminates the measuring device 7. The measuring window capsule 11 'is preferably light-tight and, for this purpose, white, black or mirrored in. An advantage of this embodiment is that it is invisible to the user in that the light of the monitor LED module 3 "does not contribute to the useful radiation of the headlight. The monitor LED module can therefore be interconnected independently of the other LED modules and at any time a measurement of the current LED luminous flux components are performed without this disturbing variations in brightness could occur during film or video recordings.

In the embodiment of Figures 21a, 21b, the measuring device 7 is also located on the back of the LED board 1. The measuring device 7 is illuminated analogous to Figure 19a, 19b on the reflected light from a diffuser plate 9 in a measuring window capsule 11 '. The measuring device 7 is located next to the monitor LED module 3 ^" on the underside of the LED board 1 and within the measuring window capsule 11 '. Another embodiment is shown in FIGS. 9a, 9b. In this embodiment, the LEDs 5 are designed as side-emitting LEDs. Preferably, an arrangement with five groups consisting of side-emitting LEDs is provided, wherein one LED group consists of white phosphor LEDs and four LED groups of color LEDs. Each of the five groups consists of side-emitting LEDs of a specific color. The luminous flux components of the five colors of the side-emitting LEDs are each driven in groups in order to set the desired color or color temperature can.

For example, 11 times 17 side-emitting LEDs are provided, which are divided into five colors as follows: 17 cyan color LEDs with a peak at 501 nm, 32 green color LEDs with a peak at 522 nm, 103 daylight white Fluorescent LEDs, 24 yellow color LEDs with a peak at 593 nm and 11 red color LEDs with a peak at 635 nm.

The light emerging from the side-emitting LEDs 5 is coupled into a light guide plate 12, which generates a light mixture and thus a uniformly luminous and color-homogeneous surface by multiple reflections. The light guide plate 12 has downwardly a reflective coating or a highly reflective optical layer 13. Also lateral Verspiegelungen 14 are provided to prevent light loss by laterally exiting light. Upwards, the light guide plate 12 can be formed either clear or with an optical microstructure for targeted beam steering (not shown).

In the Lichtleitplatte 12 and the reflective lower layer 13 holes 15 for the LEDs 5 are introduced, which are not carried out continuously. The holes 15 have bevels 151 on their upper side, which cause an upwardly emerging radiation component of the LEDs 5 also coupled laterally into the light guide plate 12 and thus the homogeneity is further improved.

In the circumferential reflective coating 14, a small opening 16 is introduced, in which the sensor chip 7 is arranged. This thus captures the intensity of all LEDs.

For control and regulation, it is sufficient if the sensor 7 in each embodiment receives a constant proportion of luminous flux per LED color, which is directly proportional to the total luminous flux component of the LED color of the headlamp. Calibration of the headlamp (see Fig. 14, Calibration flow chart) dermal intensity correction factors and Dimmcharakteristiken determined and stored for each headlight in the internal memory.

The measurement of the individual LED colors can be triggered manually and indicate an optical and / or audible signal device, the deviation of the current setting of a predetermined target value.

Preferably, the desired color temperature and / or the desired color location and / or an emulation of preset color correction filters is input by means of a user interface.

The color correction can also be done and performed by inputting .plus / minus Green 'for color shifts along the Juddian line or inputting a CTO or CTB value for color shifts along the Planckian curve. The specification of a CTO value (CTO: Color Temperature Orange) means a reduction in the most similar color temperature, while a CTB value (CTB: Color Temperature Blue) means an increase in the most similar color temperature. These values are typically used to specify color correction filters and are provided by manufacturers of typical color correction filters.

The flowchart shown in FIGS. 10a to 10c of a program for color adjustment and control of an LED headlight starts after the start 100 with an initialization 101 for measuring the intensity of the LED colors, which is shown in FIG. 11 to FIG Flowcharts performed and example, according to the flowchart of FIG. 11 individually and in each case to 100% measured. Subsequently, in the program step 102, the calibration factors kX, kY, kZ are read in from an EEPROM memory, and subsequently the user is asked in step 103 to input the desired color temperature Tsoll.

In the subsequent step 104, the desired brightness components for the settings "tungsten" and "daylight" are read from the EEPROM memory and subsequently the desired brightness components of the LED colors for the target color location with the coordinates xsoll, ysoll as a function of the desired Color temperature Tsoll calculated in program step 105. In the calculation method 106, the target color location with the coordinates x and y is first determined as a function of the target color temperature Tset, and then a linear interpolation of the basic mixtures for "tungsten" and "daylight" is performed on the target color location determined by the coordinates x and y.

Since the two basic blends for warm white and daylight white (about 3200 K and 5600 K) can be calculated exactly on Planck, a linear interpolation between these two color words results in slight deviations from the Planckian curve, the greater the farther the color temperature of one of the two basic mixtures is removed. However, the deviations maximum Δy = 0.006 and thus a maximum of 2 threshold units and can thus be neglected, moreover, these maximum deviations occur in an uninteresting for film and video recordings color temperature range around 4000 K .... 4500 K.

In the next step 107, a decision is made as to whether a color correction with filters is to be emulated and, if confirmed in step 108, the target brightness components of the LED colors determined for the new target color location xset, yset are calculated. This is followed by a program step 109 for calculating the correction factors k.sub.X, k.sub.Y and k.sub.Z for the set color mixture and subsequently, in step 110, the characteristic curves for each LED color are read.

After calculating the desired drive signals of the xsoll, ysoll LED colors from the ^■ target brightness values and the characteristics for each LED color (step 111), taking into account the maximum brightnesses measured at initialization for each maximum brightness output LED color (Block 112), the LEDs are activated in program step 113 with desired drive signals, and in step 114 the color values RO, GO, BO of the total radiation are measured.

This is followed in program step 115 by a calculation of the standard color values

XO = kX * RO YO = kY * GO ZO = KZ * BO and the standard color value components for the coordinates xθ and yθ of the color locus

xθ = f (X0, Y0, Z0) yθ = f (X0, Y0, Z0)

as a function of the standard color values XO, Yo and ZO.

In the following program step 116 it is decided whether the chromaticity distance between xθ, yθ on the one hand and xsoll, ysoll is greater than a predefined threshold value. If this is the case (YES), the system jumps to step 121 and issues a warning "color deviation." If this is not the case, then the values Rt, Gt, and Bt are measured in step 117, and in step 118 standard color values Xt, Yt and Zt and standard color value components xt and yt.

If an abort of the program is decided at the subsequent decision block 119, the program jumps to the end 125. Otherwise, it is decided in step 120 whether the chromaticity distance between the standard chromaticity coordinates for the coordinates xθ and yθ of the color locus on the one hand and the standard chromaticity coordinates xt, yt greater is a predetermined threshold. If this is the case (YES), then the warning "color deviation" also occurs in step 121. If this is not the case (NO), the program jumps back to step 1 17 and passes again after a measurement of the values Rt, Gt and Bt the loop described above.

After issuing the warning "color deviation", a decision is made in program step 122 about a color correction which, if affirmative in step 123, results in an intensity measurement of the LED colors individually, subtractive or grouped according to the flowcharts shown in FIGS. 11 to 13. In the case of a negative, the program jumps back to step 117 and, after measuring the values Rt, Gt and Bt again, goes through the loop described above.

After calculating the required intensity differences for each LED color in the last program step 125, a calculation of the corrected target control signals for each of the predetermined LED colors. Fig. 11 shows a flow chart for a single intensity measurement of the LEDs. After the program has been started, for example in the first program step 100 or at start 200, the LED colors are activated individually in program step 201 and their RGB or intensity values Ri, Gi and Bi are measured in program step 202. In the subsequent decision block 203, a decision is made as to whether all predefined LED colors have been measured. If this is answered in the negative, the program jumps back to program step 201. After all LED colors have been activated and measured, the program is ended with program step 204.

In the flowchart for alternative grouped intensity measurement of the color LEDs shown in FIG. 12, after the program start in the output step 300 and an initialization of the intensity measurement of the individual color LEDs, a group activation is made in program step 301 (RMOO, GMOO, BM00) with two or three LED colors simultaneously in program step 302. This is followed in program step 303 by a measurement of the RGB values of the mixed radiation Rm, Gm and Bm of the LED group.

Subsequently, in program step 304, a calculation of the RGB values of the involved LED colors # 1, # 2, possibly also # 3 according to the equations

Rm = k1 * R1_100 + k2 * R2_100 + k3 * R3_100 Gm = k1 ^* G1_100 + k2 * G2_100 + k3 * G3_100 Bm = k1 ^* B1_100 + k2 ^* B2_100 + k3 ^* B3_100

R1 = k1 * R1_100

G1 = k1 * G1_100 B1 = k1 * B1_100

R2 = k21 ^* R2_100 G2 = k2 ^* G2_100

B2 = k2 * B2_100

R3 = k3 ^* R3_100

G3 = k3 ^* G3_100 B3 = k3 * B3 100 In program step 305, a decision is made as to whether all the LED colors have been measured in groups and either the program has been terminated with END 306 or returned to program step 302.

In the embodiment of FIGS. 22 to 24, the method for color measurement and possible control steps can be implemented much more simply with only three colors since, after an initial measurement at the start of the program during operation of the headlamp, it is clear from the RGB signal of the total radiation, analogous to that of FIG. 12 group activation of up to 3 colors simultaneously, which could determine luminous flux components of the 3 LED colors. In the case of deviations from the predetermined target color location, a "warning" to the user would thus be omitted since the "flashing" of the individual LED colors triggered manually or automatically in order to determine their luminous flux components could be circumvented. Instead, the color location could be readjusted immediately, constantly and without any disturbance to the user or the camera.

Fig. 13 shows a flow chart for a subtractive intensity measurement of the LEDs. After the program start (start 400) and activation of all LEDs in program step 401, the RGB values of the total radiation Rg, Gg and Bg of the RGB values are measured in program step 402. After a single deactivation of one LED color in program step 403 respectively In the program step 404 again the RGB or intensity values Rgi, Ggi, Bgi measured and then in the program step 405, the RGB data of the jewiligen LED color according to the equations

Ri = Rg - Rgi Gi = Gg - Ggi

Bi = Bg - Bgi

certainly. This loop is passed through decision block 406 until it is determined that all LED colors have been measured so that the program end is reached in program step 407.

Fig. 14 is a flowchart for determining the color correction factors for calibration used in program step 109 of the color adjustment program of an LED headlamp shown in Figs. 10a to 10c. After program start 500, in program step 501, the LED colors are activated individually and at 100%. Subsequently, in program step 502, their RGB data Ri, Gi, Bi are measured with an integrated RGB sensor, and in program step 503 the standard color values Xi, Yi, Zi of the LED colors are measured with an external precision measuring device. Thereafter, in program step 504, the calibration factors for the sensor are calculated from the two measurements according to the equations

kXi = Xi / Ri kYi = Yi / Gi kZi = Zi / Bi

calculated. After the decision 505, this loop is run through until all LED colors have been measured, and subsequently, in the program step 506, the calibration factors kXi, kYi and kZi are stored in a memory and the program is concluded with the END 507.

FIG. 15 shows a flow chart for determining characteristic curves for the brightness as a function of the drive signal for calibrating the LED modules. After the start 600 of the program, a variation of the on control signal from 0 to 100% is performed for each color LED in the program step 601 and the brightness Gi is measured as a function of the drive signal. Ideally, this characteristic is determined with an external sensor. After a normalization of the characteristic curve in program step 602 to Gi _max = 100%, this loop is passed through after decision 603 until all LED colors have been measured. Subsequently, in the program step 604, the characteristic curves in the form Gi = f (control signal) are stored in the memory and the program is terminated in step 605.

16 is a flowchart for emulating color filters for color correction of the LED modules as used in program step 108 of the color adjustment control program of an LED headlamp.

After the program has been started in program step 700, user input of the color correction takes place in program step 701 after selecting one or more color filters

(eg VT minus green). This is followed in program step 702, a reading of the spectral transmittance (s) pi (λ) ... p _n (λ) of the or the selected filter from a Memory. In program step 703, the Planckian radiation distribution for the set color temperature becomes TSOLL according to the function

SPIanck = f (T soll)

calculated.

Subsequently, in the program step 704, the standard color value components x, y of the filter or of the filter combination in the case of a fluoroscopy with Planck radiation of the color temperature T _SO LL according to the equations

Srel (λ) = P ₁ (λ) * ... * p _n (λ) * SPIanck (λ)

X, Y ₁ Z = f (S rel) x, y = f (X, Y, Z)

calculated. Finally, in the program step 705, a calculation of the required brightness components for the adjustment of the color locus with the coordinates x and y is carried out, wherein according to the program step 706 a color mixture contains the maximum contribution of the LED combination for TSOLL in order to maximize the color quality of the optimized mixture to obtain. The program for emulating color filters for a color correction of the LED modules is finished with program step 707.

The program shown in FIGS. 10a to 10c and described above for adjusting the color of an LED headlight and the subroutines shown in FIGS. 11 to 16 and described above provide only a selection of possible programs for implementing the method according to the invention in use In particular, the described calculation steps for determining the color locus from a user input in which the color temperature or color correction or Filteremulation is specified and then from this the required brightness components of the LED colors are determined once be performed outside of the headlamp or its control device and stored in the form of tables in the memory of the headlamp or its control device. For example, the tables may contain the required brightness levels of the LED colors depending on the color location or the color temperature. In addition, these can Tables are calculated for color rendering-optimized settings as well as additionally for optimized settings and stored in memory.

LIST OF REFERENCE NUMBERS

1 LED board

2 control device (microprocessor)

3, 3 'LED modules

3 "monitor LED module

4 yellow-green or daylight or warm white fluorescent LED

5 side emitting LEDs

7 measuring device

8, 8 'optical fiber

9 diffuser plates

91 Mirror layer of the diffuser plate

10 cover or diffuser

11, 11 'measuring window capsule

12 light guide plate

13 reflective lower layer

14 circumferential mirroring

15 holes for LEDs

151 bevels of the holes

16 opening in all-round mirroring

40 chip of yellow-green or daylight or warm white fluorescent LED

41 phosphor layer of the yellow-green or daylight or warm white fluorescent LED

61 blue or cyan color LED

62 green color LEDs

63 amber or amber color LED

64 red color LEDs

A amber LED color

B Blue LED color

DL daylight white phosphor

G Green LED color

Ga1, Ga2 Gamut

P Planck ^'s Curve

R Red LED color Ye yellow LED color

Y yellow-green phosphor

WW Warm white phosphor

Claims

claims

1. Headlamps for film and video recordings with light-emitting diodes (LEDs) arranged on a light-emitting surface,

marked by

at least three LEDs (4; 5; 61-64), of which color LEDs (61-64) emit different LED colors (R, G, A, B, Ye) and provide luminous flux components for color mixing, and at least an LED consists of a phosphor LED (4), and with a device (2) controlling the LEDs (4; 5; 61-64) at least in groups to set the luminous flux component emitted by the LEDs (4; 5; 61-64) ,

2. Headlight according to claim 1, characterized in that the phosphor LED consists of a yellow-green or daylight, neutral or warm white fluorescent LED (4).

3. Headlight according to claim 2, characterized in that the phosphor layer (41) of the yellow-green or daylight, neutral or warm white fluorescent LED (4) covers at least a part of the color LEDs (61 - 64).

4. Headlight according to claim 2 or 3, characterized in that at least one color LED (61) emits the LED color "blue" or "cyan".

5. Headlight according to claims 3 and 4, characterized in that the phosphor layer (41) at least a part of the color LEDs (62-64) with the exception of the LED color "blue" or "cyan" emitting color LED ( 61).

6. Headlight according to at least one of the preceding claims, characterized in that the individual color LEDs (61-64) are arranged on a substrate with chip-on-board technology.

7. Headlight according to at least one of the preceding claims, characterized in that the individual color LEDs (61-64) are embedded with chip-on-board technology in micro-reflectors.

8. Headlight according to at least one of the preceding claims, characterized in that the LEDs (4; 61-64) are combined to form an LED module (3) and the light-emitting surface of the headlight from an LED board (1) an LED module (3) or an array of LED modules (3).

9. Headlight according to claim 8, characterized in that the headlight has a plurality of LED boards (1).

10. Headlight according to at least one of the preceding claims, characterized in that the LED modules (3) have a predetermined number of color LEDs (61-64) and phosphor LEDs (4), wherein for each LED color (R, G, A, B, Ye) at least one color LED (61-64) is provided.

11. Headlight according to at least one of the preceding claims, characterized in that the phosphor layer (41) of the phosphor LED (4) to the chip (4) of the phosphor LED (4) adjacent chips of the color LEDs (62 - 64 ) of the red, green, orange, yellow-orange or yellow wavelength range and that one or more color LEDs (61) of the blue or cyan wavelength range are arranged around or next to the phosphor layer (41).

12. Headlight according to at least one of the preceding claims, characterized in that the LED modules (3) each have at least five different LEDs (4; 5; 61-64), of which - an LED as a yellow-green or white phosphor LED (4), one LED as a monochrome cyan or blue color LED (61), one LED as a monochrome green color LED (62) and two LEDs as different monochrome color LEDs (63, 64) with a red one , orange, yellow-orange or yellow LED color (R, A, Ye) are formed.

13. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) - a yellow-green or white fluorescent LED (4), a monochrome blue color LED (61) having a peak wavelength from 430nm

- 480nm, a monochrome green color LED (62) with a peak wavelength of

505nm - 535nm, - a monochrome amber color LED (63) with a peak wavelength of 610nm - 640nm and a monochrome red color LED (64) with a peak wavelength of 630nm

- have 660nm.

14. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) a yellow-green or white phosphor LED (4), - a monochrome cyan color LED (61) having a peak wavelength from

480nm - 515nm, a monochrome green color LED (62) with a peak wavelength of

505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm and a monochrome amber color LED (63) with a peak wavelength of 610nm - 640 nm.

15. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) a yellow-green or white phosphor LED (4), a monochrome cyan color LED (61) having a peak wavelength of 480nm -515nm, a monochrome green color LED (62) with a peak wavelength of

505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm -

610nm, - a monochrome amber colored color LED (63) with a peak wavelength of 610nm - 640nm and a monochrome blue color LED (61) with a peak wavelength of 430nm

- 480nm.

16. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) a yellow-green or white phosphor LED (4), - a monochrome cyan color LED (61) having a peak wavelength from

480nm - 515nm, a monochrome green color LED (62) with a peak wavelength of

505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm and a monochrome red color LED (64) with a peak wavelength of 630nm

- have 660nm.

17. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) a yellow-green or white phosphor LED (4), a monochrome cyan color LED (61) having a peak wavelength of 480nm - 515nm, a monochrome green color LED (62) with a peak wavelength of 505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm, - a monochrome red color LED (64) with a peak wavelength of 630nm

- 660nm and a monochrome blue color LED (61) with a peak wavelength of 430nm

- 480nm.

18. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) a yellow-green or white phosphor LED (4), - a monochrome cyan color LED (61) having a peak wavelength from

480nm - 515nm, a monochrome green color LED (62) with a peak wavelength of

505nm - 535nm, a monochrome amber color LED (63) with a peak wavelength of 61 onm - 640 nm and a monochrome red color LED (64) with a peak wavelength of 630nm

- have 660nm.

19. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) a yellow-green or white phosphor LED (4), a monochrome cyan color LED (61) having a peak wavelength of 480nm - 515nm, a monochrome green color LED (62) with a peak wavelength of 505nm - 535nm, a monochrome amber color LED (63) with a peak wavelength of 610nm - 640nm, - a monochrome red color LED (64) with a peak wavelength of 630nm

- 660nm and a monochrome blue color LED (61) with a peak wavelength of 430nm - 480nm.

20. Headlight according to at least one of the preceding claims 1 to 12, characterized in that the LED modules (3) a yellow-green or white phosphor LED (4), - a monochrome blue color LED (61) having a peak wavelength from 430nm

- 480nm, a monochrome green color LED (62) with a peak wavelength of 505nm - 535nm, a monochrome yellow color LED with a peak wavelength of 580nm - 610nm and a monochrome red color LED (64) with a peak wavelength of 630nm

- have 660nm.

21. Headlight according to at least one of the preceding claims 1 to 11, characterized in that the LED modules (3) a yellow-green or white fluorescent LED (4), a monochrome blue color LED (61) having a peak wavelength of 430 nm - 480 nm and a monochrome red color LED (64) with a peak wavelength of 630 - 660 nm.

22. Headlight according to at least one of the preceding claims, characterized in that at least one measuring device (7) between the LED board (1) and the front side of the headlamp is arranged.

23. Headlight according to claim 22, characterized in that the measuring device detects the radiation intensity of the LEDs (4; 5; 61-64) and is designed as a color measuring device, RGB sensor, V (λ) sensor or light sensor.

24. Headlight according to claim 23, characterized in that the measuring device (7) is formed by at least five light sensors of different spectral sensitivity.

25. Headlight according to claim 23 or 24, characterized in that the measuring device detects the radiation intensity of the LEDs (4; 5; 61-64) continuously or at predetermined time intervals.

26. Headlight according to at least one of the preceding claims 22 to 25, characterized in that the measuring device (7) is regulated to a constant temperature.

27. Headlight according to at least one of the preceding claims 22 to 26, characterized in that a representative portion of each LED color (R, G, A, B, Ye) is coupled into the photosensitive surface of the measuring device (7).

28. Headlight according to at least one of the preceding claims 22 to 27, characterized in that in front of an array of LED modules (3) mounted diffuser collects light and an opening of a surrounding mirroring mirror part of the light in the measuring device (7 ).

29. Headlight according to at least one of the preceding claims 22 to 28, characterized in that at least one at a thermally representative point of the array of LED modules (3) arranged monitor LED module (3 ") for illuminating the measuring receiver ( 7) is used and a portion of the radiation emitted by the monitor LED module (3 ") radiation in the measuring device (7) is coupled.

30. Headlight according to claim 29, characterized in that the light emitted by the monitor LED module (3 ^" ) a diffuser plate (9) and from the diffuser plate (9) to the measuring device (7) is reflected or directed.

31. Headlight according to claim 30, characterized in that the light from the diffuser plate (9) via a light guide (8 ') on the measuring device (7) is passed.

32. Headlight according to claim 30 or 31, characterized in that the diffuser plate (9) on the underside of a transparent disc (10) is arranged, which is arranged above the light-emitting surface of the headlamp.

33. Headlight according to claim 30 or 31, characterized in that the diffuser plate in a capsule (11, 11 ") is arranged, which is placed on one side of the light-emitting surface of the headlamp and the monitor LED module (3") and the measuring receiver (7) surrounds.

34. Headlight according to claim 33, characterized in that the capsule (11, 11 ') is formed light-tight.

35. Headlight according to claim 33 or 34, characterized in that the monitor LED module (3), the measuring receiver (7) and the capsule (11, 11 ') are arranged on the underside of the light-emitting surface of the headlamp.

36. Headlight according to at least one of claims 30 to 35, characterized in that the diffuser plate (9) on its side facing away from the measuring receiver (7) side has a reflective coating (91).

37. Headlight according to claim 29, characterized in that the measuring device (7) is located on the monitor LED module (3 ") facing away from the end of a capsule (11 ') which above the monitor LED module (3"). ) is arranged on the top or bottom of the light-emitting surface of the headlamp.

38. Headlight according to at least one of the preceding claims, characterized in that the LEDs (5) are designed as side emitting LEDs.

39. Headlight according to claim 38, characterized in that the LEDs (5) have a light distribution, which is designed so that on one of the LEDs (5) illuminated surface, a constant illumination intensity distribution can be generated.

40. Headlight according to claim 38 or 39, characterized in that on the light-emitting surface of the headlamp, a light guide plate (12) is realized, wherein the output from the side emitting LEDs (5) light is mixed by the light guide plate (12).

41. Headlight according to claim 40, characterized in that the light guide plate (12) is realized with a circumferential reflective coating (14).

42. Headlight according to claims 22 and 41, characterized in that in the circumferential reflective coating (14) has an opening (16) in which the measuring device (7) is arranged.

43. Headlight according to at least one of the preceding claims 22 to 42, characterized in that the measurement of the radiation intensity of the individual LED colors (R, G, A, B, Ye) is manually triggered.

44. Headlight according to at least one of the preceding claims 22 to 43, characterized in that an optical and / or acoustic signal means indicates the deviation of the current setting of a predetermined desired value.

45. Headlight according to at least one of the preceding claims 22 to 44, characterized in that by means of a user interface, the desired color temperature and / or the desired color locus for setting by the headlamp is predetermined.

46. Headlight according to at least one of the preceding claims 22 to 45, characterized in that by means of a user interface, a color correction, emulating the advanced color correction filter, and / or a light color emulating the color filter, is adjustable for reproduction by the headlight.

47. Headlight according to at least one of the preceding claims, characterized in that the headlamp is adapted to adjust the color temperature in a dimming mode in dependence on the brightness of the headlamp.

48. Headlight according to at least one of the preceding claims, characterized in that the headlamp is designed to emulate a light color selected by a user and / or light source.

49. A method of adjusting the color characteristic output by a headlamp according to the preceding claims,

characterized in that

after switching on the headlamp, the available radiation components of the LED colors (R, G, A, B, Ye) are measured,

during operation, the current RGB or intensity values of the LED colors (R, G, A, B, Ye) are measured continuously or at predetermined intervals, and

the radiation intensity of the LED colors (R, G, A, B, Ye) is readjusted taking into account the current RGB or intensity values determined for each LED color (R, G, A, B, Ye).

50. Method according to claim 49, characterized in that the current color location is calculated from the current RGB or intensity values of the total radiation of the LED colors (R, G, A, B, Ye) and, in the case of deviations from the target color location, the current RGB color. or intensity values of the individual LED colors (R, G, A, B, Ye) are measured, whereupon the radiation intensity of the LED colors (R, G, A, B, Ye) taking into account the for each LED color (R , G, A, B, Ye) readjusted current RGB or intensity values.

51. The method of claim 49 or 50, characterized in that the radiation components of the LED colors (R, G, A, B, Ye) by briefly successive activation of the individual LED colors (R, G, A, B, Ye ) and measuring the RGB or intensity values of the individual LED colors (R, G, A, B, Ye).

52. The method according to claim 49 or 50, characterized in that the radiation components of the LED colors (R, G, A, B, Ye) are ren by successively activating two or at most three LED colors (R, G, A, B, Ye), measuring the RGB and intensity values, respectively, and calculating the intensities of the individual LED colors (R, G, A, B, Ye).

53. The method of claim 49 or 50, characterized in that the radiation components of the LED colors (R, G, A, B, Ye) by measuring the total radiation of all LED colors (R, G, A, B, Ye), sequentially switching off individual LED colors (R, G, A, B, Ye), measuring the RGB or intensity values of the remaining LED colors (R, G, A, B, Ye) and subtracting the values thus measured to determine the RGB or intensity values of the LED

Color (R, G, A, B, Ye) are determined.

54. Method according to claim 49 or 50, characterized in that the radiation components of the LED colors (R, G, A, B, Ye) are measured by measuring the total radiation of all LED colors (R, G, A, B, Ye ) with light sensors of different spectral

Sensitivity are determined, the number of light sensors corresponding to the number of LED colors used (R, G, A, B, Ye).