DE102010042200A1 - Lighting module for lighting device in surgical microscope for producing illumination light during ophthalmic surgery of patient, has electrical assembly that operates white light LEDs with different electric currents based on preset value - Google Patents

Abstract

The module (10) has an interface (46) for connecting an optical light transmission system (42). An optical system (48) collects light of white light LEDs (12, 14, 16) and transfers the light to a passage surface for light of the interface. An electrical assembly (26) controls the white light LEDs for adjusting intensity of illumination light provided at the interface at a preset value in one of operating conditions. The assembly operates the LEDs with different electric currents depending on the preset value. The LEDs are thermally connected to a common cooling body (24). Independent claims are also included for the following: (1) a method for operating a lighting module (2) a lighting device including a carrier housing.

Description

The invention relates to a lighting module having at least one first white light LED and at least one second white light LED, with an interface having a passage surface for the connection of an optical transmission system for light, with an optical system which transmits the light of at least one first white light. LED and the at least one second white light LED collects and leads to the passage surface for light of the interface, and with an electrical assembly for controlling the at least one first white light LED and the at least one second white light LED. The invention also relates to a lighting device with such a lighting module. Moreover, the invention relates to a lighting system with a plurality of such lighting modules.

An illumination module of the type mentioned is from the DE 10 2009 005 839 A1 known. In this lighting module there are several light sources in the form of red, green, blue and white LEDs. These light sources are assigned a control unit. The lighting module comprises a field with honeycomb-shaped collector lenses and a converging lens. By means of the collector lenses and the converging lens, the light of the light sources is fed to an optical waveguide. For adjusting the spectral composition of illumination light generated with the light sources, the illumination module includes a control device. The control device allows the individual control of the light sources in the lighting module. This illumination module is designed for the production of illumination light that is suitable for use in medical observation devices, such as surgical microscopes.

In such observation apparatus, it is desired that the illuminating light for an observer cause an observation image with high image brightness and natural visual impression when examining a colored object area.

The perceived by an observer color impression of the observation image is dependent on the spectral intensity distribution of the illumination light. The effect of the illumination light from a lighting module on the color impression can be quantified by means of a color rendering index. Such a color rendering index can be z. B. based on the on the P. 317 in E. Fred Schubert, Light Emitting Diodes, Cambridge University Press, Second Edition 2006 calculated formula expression 19.9. This color rendering index is a numeric value. The numerical value is a measure of the color fidelity of a normalized color panel illuminated with the illumination module as a light source in comparison with a light source in the form of a thermal blackbody emitter. The color rendering index for sunlight is 100. The color rendering index does not depend on a specific color temperature of the blackbody radiator. Any light source that perfectly reproduces the spectrum of a blackbody with a specific color temperature in the visible wavelength range will achieve a color rendering index of 100.

Illuminating light with a high color rendering index, which approximates to sunlight, is desirable in medical-optical observation devices, because doctors distinguish different types of inflammation, in particular from the red hue of body tissue. However, this is only possible if the spectral intensity density of the illumination light in the red spectral region is greater than zero, runs continuously and has no gaps.

A color rendering index of 100 can be achieved with light from xenon high pressure lamps. However, such xenon high-pressure lamps have a limited life and they must be laboriously cooled.

In addition, the intensity of the light from thermal light sources, such as. As high-pressure xenon lamps, adjust only within narrow limits by varying the lamp current, without the course of the spectral intensity distribution of the light of the light source is changed greatly due to different values of the lamp current and without the stability of an arc collapses in such lamps.

On the other hand, the intensity of the light of an LED can be modified over wide ranges by varying the current conducted by an LED without having a greater effect on the shape of the spectral intensity distribution curve as a function of the wavelength of the light. However, due to the exponential characteristic of the current-voltage characteristics of LEDs, precise control of the intensity of the generated light in the range of light intensities that are below 10% of the maximum intensity of light from a light emitting diode is not possible by varying current and voltage , Indeed, even the smallest relative changes in the lamp current conducted by an LED cause very large relative changes in the light intensity of the illumination light generated by the LED.

In order to adjust the intensity of the illumination light generated in illumination modules for medical observation devices, conventionally adjustable screen diaphragms are therefore used. These panels have a variety of openings whose Size and number per unit area varies across the screens. By displacing the screen aperture in an illumination beam path, the portion of the screen aperture that is penetrated by the illumination light can be adjusted. According to the number and size of the openings of the screen aperture, which are arranged in the illumination beam path, the light flux passing through the screen aperture can be controlled. For such a screen panel, a sufficiently large space must be provided in a lighting system. In addition, since a screen aperture is heated when used in an illumination system, complex cooling is required, especially at high light outputs.

The object of the invention is to provide a lighting module which allows the generation of white illumination light with an intensity that can be varied over a wide range.

This object is achieved by a lighting module of the aforementioned type, in which the electrical assembly for setting the intensity of the illumination light provided at the interface to a predefinable value in at least one operating state the at least one first white light LED and the at least one second white light LED with a different, dependent on the predeterminable value electric current operates.

When the at least one first white light LED and the at least one second white light LED are configured to generate light having the same color temperature, by varying the current flowing through the white light LED, the intensity of the illumination light provided at the interface can be be controlled without noticeably changing the color temperature for an observer.

It is advantageous if the optical transmission system guides the light of the at least one first white light LED and the at least one second white light LED to the passage surface for light of the interface in such a way that the passage surface for light of the interface both with light of the at least one first White light LED as well as with the light of the at least one second white light LED can be illuminated.

Since the at least one first white-light LED and the at least one second white-light LED are designed to produce white light with a different color temperature, it is also possible to set the color temperature in the illumination module. Extensive tests have shown that with a lighting module in which the at least one first white light LED for generating white light with the color temperature T _F = 5500 ° K ± 500 ° K is designed and the at least one second white light LED white light with a Color temperature T _F = 4400 ° K ± 500 ° K generated, the illumination range of surgical microscopes can be illuminated so that the detected with the surgical microscope illumination light is bright and has a good contrast. In particular, it has been shown that the light from such an illumination module in ophthalmic surgical microscopes enables light and high-contrast observation images of a patient's eye.

It is advantageous if the at least one first white light LED and the at least one second white light LED have a blue light emitting LED and an enforceable with light of the LED optically transmissive layer with phosphor material with different layer thickness and / or different chemical configuration of the phosphor material to have. It has been shown that in a surgical microscope with a lighting module that contains at least four first white light LEDs and at least three second white light LEDs, excellent field illumination of the object area is possible. With the electrical assembly, the first white light LEDs and the second white light LEDs are conveniently driven as groups. That is, in a group formed by a plurality of LED's, the current flowing through the LED's is set to the same value.

The light output that can be generated by the lighting module can be increased when the white light LEDs are cooled. Moreover, by adjusting the favorable operating parameters for a white light LED, the course of the spectral intensity distribution can be optimized for a given application. Efficient cooling can be achieved by thermal coupling of white light LEDs to a preferably common heat sink. For the effective dissipation of the heat that occurs during operation of the white light LEDs, it is advantageous if the at least one first white light LED and the at least one second white light LED is accommodated on a light source carrier which is fixed to the heat sink. This heat sink conveniently has at least one cooling fin. As a carrier for the white light LEDs is particularly suitable a metal core board. Here, the outflow of heat generated by means of the LEDs can be improved if heat conduction material is arranged between the light source carrier and the heat sink.

Preferably, the lighting module includes a cooling device for cooling the heat sink. As a cooling device is z. B. a blower designed as a fan for the flow against the at least one cooling fin with fluid, in particular with Air. For the removal of heat, the heat sink can also be combined with a cooling system comprising a heat pipe and / or a water cooling.

The precise adjustment of the intensity of the illumination light provided with the illumination module at the interface is made possible by the electrical assembly for attenuating the intensity of the illumination light provided at the interface to a predetermined value from an operating condition in which the at least one first white light LED and the at least one second white light LED is operated with a substantially equal electric power, the at least one first white light LED is operated in a first step with increasing electric power and in a subsequent second step with decreasing electric power, and at least a second white light LED is operated with decreasing electrical power or is turned off.

To be used in a lighting device for medical-optical equipment such. As a surgical microscope to ensure good heat dissipation from the arranged in the lighting module heat sink, it is advantageous if the lighting device has a carrier housing with an opening. Advantageously, this carrier housing has a connection element for fastening to a mounting portion in a stand for medical-optical equipment. In this case, the illumination module is accommodated in the carrier housing in a favorable manner such that the heat sink is at least partially released from the opening in the carrier housing.

A heat sink can in principle also be designed as a carrier housing of a lighting module.

In an illumination system having a plurality of illumination modules, which have heat sinks, it is advantageous if the heat sinks are thermally coupled by at least two illumination devices arranged adjacent to one another. For this purpose, the heat sink z. B. be connected through the opening in the carrier housings through a thermal contact. In this way, the heat dissipation of the white light LEDs can be optimized, since a heat dissipation through a plurality of heatsinks is made possible and the heatsinks can also act as heat sinks.

In this case, a thermal contact of the heat sink is effected by an arranged between the heat sinks, preferably designed as a copper plate metal plate. In an illumination system and an additional heat sink can be integrated, which is thermally coupled to the heat sink of a lighting module. This allows a particularly efficient removal of heat from the arrangement.

In the following the invention will be explained in more detail with reference to the embodiments schematically illustrated in the drawing.

Show it:

1 a lighting module with a plurality of white light LEDs and a heat sink;

2 a white light LED in the lighting module;

3 the characteristic of the white light LED for current and voltage;

4 the spectral intensity distribution of the illumination light generated in an LED current;

5 the light output of the LED for different LED currents;

6 the white point of the LEDs in the lighting module in a CIE color space;

7 the heat sink in the lighting module having a metal core board and white light LEDs fixed to the heat sink;

8th a plan view of the fixed to the heat sink metal core board with white light LEDs;

9 the light flux of the illumination light generated by the illumination module in different operating states;

10 a section of the surgical microscope with the illumination system in an exploded view;

11 another lighting system with lighting modules, which have a heat sink; and

12 a lighting system with heatsinks for high-power LEDs, which are thermally connected via brackets.

The 1 shows a lighting module 10 for a lighting device in a surgical microscope. The lighting module 10 contains several white light LEDs 12 . 14 . 16 on a metal core board 18 are arranged. The metal core board 18 acts as a light source carrier in the lighting device. The metal core board 18 is by means of screws 20 . 22 on a heat sink 24 established. The heat sink 24 is made of aluminum. In the lighting module 10 is there for controlling the white light LEDs 12 . 14 . 16 an electrical assembly 26 , The electrical assembly 26 has a control circuit 28 , by means of which by the white light LEDs 12 . 14 . 16 Guided current can be controlled to the intensity of the means of white light LEDs 12 . 14 . 16 set to be generated illumination light.

If through the white light LEDs 12 . 14 . 16 Current flows, luminescent light is generated. Due to their electrical resistance, the white light LEDs 12 . 14 . 16 heated thereby. The heat from the white light LEDs 12 . 14 . 16 is doing over the metal core board 18 in the heat sink 24 initiated. The lighting module 10 contains a fan 30 , The fan creates a heat sink 24 impinging airflow 32 by means of which the heat sink 24 can be cooled.

The lighting module 10 has a carrier housing 34 , The carrier housing 34 has openings 36 through which the fan 30 Can suck in air.

The by means of the fan 30 generated airflow 32 can be over openings 38 from the carrier housing 34 escape.

In the carrier housing 34 is a recording 40 for a light guide acting as an optical transmission system for light 42 educated. In the recording 40 can the entrance area 44 for light in the light guide 42 at a passage surface for light of an optical interface 46 of the lighting module 10 be positioned. To do that with the white light LEDs 12 . 14 . 16 generated illumination light at the optical interface 46 There is in the lighting module 10 an optics system 48 , The optics system 48 has a structure that in the DE 10 2009 005 839 A1 is described. The optics system 48 does this by means of the white light LEDs 12 . 14 . 16 generated illumination light through a collector lens array with honeycomb collector lenses 50 and by a condenser lens 52 to the passage area for light of the interface 46 ,

The lighting module 10 contains a filter wheel 54 , The filter wheel 54 can with an adjustment motor 56 be adjusted. By adjusting the filter wheel 54 Different optical filters can be used in the illumination beam path 58 be pivoted with the optical transmission system 48 for light to the interface 46 to be led.

The carrier housing 34 of the lighting module 10 has a mounting section 60 , The mounting section 60 has a dovetail guide 62 with a fixing screw 64 on. About the mounting section 60 can the lighting module 10 so that at one to the dovetail guide 62 complementary recording, z. B. be set in a surgical microscope tripod.

The electrical assembly 26 has a facility 66 for adjusting the intensity of the at the optical interface 46 of the lighting module 10 provided illumination light. About the device 66 may be a value for a desired intensity of illumination light at the optical interface 46 be specified. According to that about the device 66 predetermined value for the intensity of illumination light is thereby via the control circuit 28 for every single white light LED 12 . 14 . 16 set a defined electric current I for generating luminescent light. By means of the electrical assembly 26 it is possible to increase the intensity L of the optical interface 46 provided illumination light between the value 0 and a maximum value L _MAX . For adjusting the intensity that at the optical interface 46 provided illumination light can with the control circuit 28 an operating state can be set in which two or more of the white light LEDs 12 . 14 . 16 are operated with a non-zero electrical power difference .DELTA.P, that of the on the device 66 set intensity of the at the optical interface 46 provided illumination light is dependent.

The 2 shows the white light LED 12 in the lighting module 10 , The white light LED 12 is a high power LED, eg. B. a high-performance LED for generating white light, which is offered by the company. Cree Inc. under the name Cree ^® XLamp ^® XR-E LED. The white light LED 12 contains a LED chip 72 which consists of GaInN / GaN. This chip 72 is on a carrier body 74 arranged and by means of contact wires 76 and 78 with a first and a second electrical connection 80 . 82 connected. In the carrier body 74 is the LED chip 72 in a phosphor layer 77 embedded. The carrier body 74 with the contact wires 76 . 78 and the LED chip 72 and the phosphor layer 77 is in a plastic body 84 cast. The operating principle of the white light LED is on P. 353 in E. Fred Schubert, Light Emitting Diodes, Cambridge University Press, Second Edition 2006 described: when through the LED chip 72 Current is conducted, it luminesces in the blue spectral range. When penetrating the phosphor layer 76 the blue light produces yellow light. The yellow light is superimposed with the blue LED light as an additive spectral color mixture to white light. This white light is then transmitted through the plastic body 84 , in which the arrangement is poured, delivered to the environment.

The 3 shows the characteristic 78 the white light LED 12 for the current I and the voltage U. For the generation of luminescent light becomes the white light LED 12 operated with a forward voltage U in a range between 2.2 V and 3.6 V. The spectral intensity distribution L of a current I with the white light LED 12 generated illumination light is in 4 with the graph 80 shown. The spectral intensity distribution 82 of the white light LED 12 emitted light has a local maximum 84 , which lies in the blue spectral range. This maximum is due to the fact that in the white light LED, the white light is generated by conversion of blue light that the LED chip 72 in 2 generated. When the blue light passes through the in 2 shown phosphor layer 72 passes through the white light LED, the phosphor is in the phosphor layer 72 excited to luminescence. This produces white light with wavelengths λ, which are in the wavelength range 84 lie. This white light is superimposed by that blue light that is not converted or absorbed in the phosphor layer. In principle, UV light in the wavelength range of 405 mm or even short-wave UV light is also suitable for exciting the phosphor layer in the white-light LED.

The 5 shows with the graph 86 the curve 88 the light output L _{total of} the white light LED 12 for different luminescence currents I. The curve 88 is convexly curved, with the curvature of the curve 88 for smaller luminescence currents I increases. From the course of the curve 88 It turns out that the intensity L is _totally the with the white light LED 12 generated luminescent light in the area 90 the curve 88 For smaller luminescence currents I can be controlled only with great effort, because even very small changes in the luminescence differently than in the middle range 92 the curve 88 leads to very large changes in the luminescence I.

The structure of the white light LEDs 14 and 16 in the lighting module 10 out 1 corresponds to the structure of the white light LED provided therein 12 ,

With the white light LEDs 14 and 16 however, the phosphor layer is made of phosphor which converts the blue light generated by the GaInN / GaN-provided LED chips provided therein into white light with another spectrum mixture. This causes by means of the white light LEDs 12 . 14 and 16 white light can be generated whose color temperature is different.

The 6 shows the color of the white light LEDs 12 . 14 and 16 produced white light in the CIE color chart 94 , The white light of the white light LED 12 corresponds to the color temperature T _F = 5800 ° K. In the color chart 94 This white light has the color place 96 , The white light of the white light LED 14 has the color temperature T _F = 4900 ° K and the color locus 98 in the CIE color chart 94 , For the color temperature of the white light of the white light LED 16 applies: T _F = 4400 ° K. This light has the color location 100 in the CIE color chart 94 , The color locations of the white light LEDs in the lighting module 10 out 1 lie on the curve 99 , The curve 99 corresponds to the color locus of the color of a black body, which generates according to its temperature electromagnetic radiation with the spectral intensity distribution of Planck's law of radiation.

The 7 is a partial section of the lighting module 10 out 1 along the line VII-VII. The metal core board 18 for the white light LEDs 12 . 14 and 16 has a metal core of copper coated with a ceramic layer. The white light LEDs 12 . 14 and 16 are set on this ceramic layer. To get a good transport of heat from the white light LEDs 12 . 14 . 16 in the heat sink 24 to ensure there is between metal core board 18 and the heat sink 24 a layer 103 made of thermal grease.

The heat sink 24 has cooling fins 104 . 106 , The space 108 between the cooling fins 104 . 106 is with the means of the fan 30 flow through the air flow generated.

The 8th is a plan view of the on the heat sink 24 fixed metal core board 18 in the lighting module 10 out 1 along the line VIII-VIII.

On the metal core board 18 are a total of seven white high-power LEDs 12 . 14 . 16 . 110 . 112 . 114 and 116 arranged. The color temperature of the white light LEDs 110 and 112 corresponds to the color temperature of the white light LED 12 , The white light LEDs 114 . 116 have the same color temperature as the white light LED 14 ,

The 9 shows in the graph 118 the light flux F at the optical interface 46 of the lighting module 10 out 1 in different operating states. To do that with the lighting module 10 provided illumination light, starting from a maximum value F _max for the entire light flux F of the illumination light provided with the illumination module to dim light, controls the electrical assembly 26 for each individual white light LED in the lighting module, the electric current I flowing through the corresponding white light LED. The curve 119 corresponds to the light flux F of the lighting module 10 at the interface 46 , In the operating state 1 For diminishing the light flux F, the white light LEDs 12 . 14 . 16 . 110 . 112 and 114 such as 116 via the control circuit 28 in the electrical assembly 26 of the lighting module 10 each with identical electrical currents I ₁₂ = I ₁₄ = I ₁₆ = I ₁₁₀ = I ₁₁₂ = I ₁₁₄ = I ₁₁₆ operated. In the of the operating condition 1 different operating state 2 on the other hand, the one by the group of white light LEDs 12 . 14 . 16 flowing current I ₁₂ , I ₁₄ , I ₁₆ according to the curve 121 lowered to zero. At the same time, however, is the group of white light LEDs 110 . 112 and 114 guided power in the operating state 2 for dimming the with the lighting module at the interface 46 provided illumination light according to the curve 122 raised. When passing through the white light LEDs 12 . 14 . 16 flowing current I ₁₂ , I ₁₄ , I ₁₆ is lowered to zero, is in the operating state 3 the lighting module 10 the current I ₁₁₀ = I ₁₁₂ = I ₁₁₄ = I ₁₁₆ passing through the white light LEDs 110 . 112 . 114 and 116 flows, for the further dimming of the lighting module 10 according to the curve 123 lowered again.

To the color temperature of the with the lighting module 10 in 1 Adjusting the illumination light generated, the intensity of the illumination light generated by the white light LEDs in the illumination module is varied. For example, the white light LEDs 12 . 110 and 112 by means of the control circuit 28 in the electrical assembly 24 in the lighting module 10 energized so that they produce high intensity illumination light. For the white light LEDs 14 . 16 and 114 such as 116 on the other hand, a low current is set. If illumination light whose color temperature is comparatively low is to be generated by means of the illumination module, the procedure is reversed. In this case, the white light LEDs 14 . 16 , such as 114 and 116 subjected to a comparatively high current. In contrast, by means of the control circuit 28 in the electrical assembly 26 the intensity of the white light LEDs 12 such as 110 and 112 retracted generated illumination light.

The 10 shows two lighting devices 148 . 150 in a tripod 151 for a surgical microscope. The lighting equipment 148 . 150 form a lighting system here 152 , which contains two lighting modules with the structure described above. The lighting system comprises a light guide 153 and a light guide 155 , The light guide 153 receives light from the lighting device 148 , The light guide 155 is using light from the lighting device 150 fed.

The lighting device 148 has a carrier housing 154 , The carrier housing 154 has an opening formed as an opening 156 for the heat sink 158 the lighting module in the lighting device 148 , The lighting device 150 has a carrier housing 160 on. Also the carrier housing 160 has an opening for the heat sink of the lighting module of the lighting device 150 ,

The lighting modules in the lighting devices 148 . 150 are in the vehicle housings 154 . 160 with fastening screws 164 . 166 . 168 . 170 established. The fixing screws 164 . 166 . 168 . 170 pass through the heat sink 158 the lighting module in the lighting device 148 and the heat sink of the lighting module in the lighting device 150 , By means of these fixing screws 164 . 166 . 168 . 170 the heat sinks are braced against each other. This causes a thermal contact between the heat sink 158 in the lighting device 148 and the heat sink of the lighting device 150 ,

About the light guides 153 and 155 in the tripod 151 can in a recorded on the tripod surgical microscope, such as the 9 the above cited DE 10 2009 005 839 A1 shows, differently adjustable lighting configurations are supplied with light. The lighting equipment 148 . 150 can be controlled independently of each other. The thermal coupling of the heat sinks arranged in the lighting devices achieves that the heat sink in the lighting module of a lighting device which is currently not operated or only operates with low power can absorb heat from the adjacent lighting device and vice versa.

The tripod 151 has a cover housing 176 for the lighting system 152 , In the cover housing 146 there are ventilation slots 178 . 180 , via the air for cooling by means of in the lighting modules of the lighting devices 148 . 150 arranged modules can enter or exit. The fans in the lighting modules are used to cool the heat sink so that the air for cooling in the heatsink according to the arrows 182 indicated flow direction occurs and the air the cover housing 146 with the flow direction according to the arrows 184 leaves. By this measure it is achieved that in the heat sinks of the lighting modules of the lighting devices 148 . 150 heated air flow is directed away from a visualized by means of the surgical microscope operation area.

The 11 shows a lighting system 200 for use in the stand of a surgical microscope. The lighting system has several lighting devices 202 . 204 , The lighting equipment 202 . 204 have interfaces 203 . 205 for the connection of a light guide. Any lighting device 202 . 204 contains a heat sink 206 . 208 . 210 , The heat sinks 206 . 208 the lighting devices are arranged side by side. For generating a thermal contact with little resistance are the heatsink 206 . 208 over a copper plate 212 connected, which acts as a thermal bridge. The heat sink 206 is with a copper plate 214 to an additional heat sink 210 connected with cooling fins.

The 12 shows a section of a lighting system 300 that has several heat sinks 302 . 304 for cooling high power LEDs 306 . 308 which is on a metal core board 310 . 312 are arranged. Each metal core board is in the corresponding heat sink 302 . 304 sunk. For thermal coupling of the heatsink 302 . 304 These are by means of parentheses 306 . 308 pressed against each other from a spring material, z. B. with staples made of spring steel.

In summary, the following preferred features of the invention are particularly noted: The invention relates to a lighting module 10 with at least a first white light LED 12 and at least one second white light LED 14 , The lighting module 10 has an interface 46 with a passage area for light. the interface 46 serves for the connection of an optical transmission system 42 for light. The lighting module 10 contains an optics system 48 , The optics system 48 The light collects the least one first white light LED 12 and the at least one second white light LED 14 and leads it to the passage area for light of the interface 46 , For driving the at least one first white light LED 12 and the at least one second white light LED 14 contains the lighting module 10 an electrical assembly 26 , With the electrical assembly 26 can change the intensity of the interface 46 provided illumination light can be adjusted. The electrical assembly 26 operates for adjusting the intensity of the interface 46 provided illumination light to a predetermined value in at least one operating state, the at least one first white light LED 12 and the at least one second white light LED 14 with a different, dependent on the predetermined value electric current.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009005839 A1 [0002, 0041, 0060]

Cited non-patent literature

• P. 317 in E. Fred Schubert, Light Emitting Diodes, Cambridge University Press, Second Edition 2006 [0004]
• P. 353 in E. Fred Schubert, Light Emitting Diodes, Cambridge University Press, Second Edition 2006 [0045]

Claims (15)

Lighting module ( 10 ) with at least one first white light LED ( 12 ) and at least one second white light LED ( 14 ), with an interface having a passage surface for light ( 46 ) for the connection of an optical transmission system ( 42 ) for light, with an optical system ( 48 ), which receives the light of the at least one first white light LED and the at least one second white light LED ( 12 ) and to the passage surface for light of the interface ( 46 ) and with at least one first white light LED ( 12 ) and the at least one second white light LED ( 14 ) driving electrical assembly ( 26 ) for adjusting the intensity of at the interface ( 46 ) provided illumination light, characterized in that the electrical assembly ( 26 ) for adjusting the intensity of the interface ( 46 ) provided illumination light to a predetermined value in at least one operating state ( 2 . 3 ) the at least one first white light LED ( 12 ) and the at least one second white light LED ( 14 ) operates with a different, dependent on the predetermined value of electric current. Illumination module according to claim 1, characterized in that the optical system ( 48 ) the light of at least a first white light LED ( 12 ) and the at least one second white light LED ( 14 ) in such a way to the passage surface for light of the interface ( 46 ) leads that the passage surface for light of the interface ( 46 ) with light from the at least one first white light LED ( 12 ) as well as with light of the at least one second white light LED ( 14 ) is illuminable. Illumination module according to the preamble of claim 1, in particular according to claim 1 or claim 2, characterized in that the at least one first white light LED ( 12 ) and the at least one second white light LED ( 14 ) is designed for generating white light with different color temperature. Illumination module according to one of claims 1 to 3, characterized in that the electrical assembly ( 26 ) for separately driving a plurality of first white light LEDs combined into a first group ( 12 . 16 . 110 . 112 ) and one of a plurality of second white light LEDs combined into a second group ( 14 . 114 . 116 ) is designed. Illumination module according to the preamble of claim 1, in particular according to one of claims 1 to 4, characterized in that the at least one first white light LED ( 12 ) and the at least one second white light LED ( 14 ) thermally to a preferably common heat sink ( 24 ) is coupled. Illumination module according to claim 5, characterized in that the at least one first white light LED ( 12 ) and the at least one second white light LED ( 14 ) on a light source carrier ( 18 ) received on the heat sink ( 24 ). Lighting module according to claim 6, characterized in that the light source carrier a metal core board ( 18 ), wherein between the light source carrier and the heat sink ( 24 ) Heat conduction material ( 103 ) is arranged. Illumination module according to one of claims 5 to 7, characterized in that a cooling device ( 30 ) is provided for the cooling of the heat sink. Illumination module according to claim 8, characterized in that the heat sink ( 24 ) at least one cooling fin ( 104 . 106 ) and the cooling device preferably as a fan ( 30 ) trained blower for the flow of the at least one cooling fin ( 104 . 106 ) with fluid, in particular with air. Method for operating a lighting module (according to one of Claims 1 to 9) ( 10 ), in which the electrical assembly ( 26 ) for dimming the intensity of the at the interface ( 46 ) provided illumination light to a predetermined value, starting from an operating state ( 1 ), in which the at least one first white light LED ( 12 ) and the at least one second white light LED ( 14 ) is operated with a substantially equal electric current, the at least one first white light LED ( 12 ) is operated in a first step with increasing electric current and in a subsequent second step with decreasing electric current, and the at least one second white light LED ( 14 ) is operated with decreasing electric current or is turned off. Lighting device ( 148 . 150 ) with an opening ( 156 ) having carrier housing ( 154 . 160 ), which is a connection element ( 62 ) for mounting to a mounting section in a tripod ( 151 ) for medical-optical equipment, and having a trained according to one of claims 5 to 9 lighting module ( 10 ), which in the carrier housing ( 154 . 160 ) is accommodated such that the heat sink ( 24 ) from the opening in the carrier housing ( 154 . 160 ) is at least partially released. Lighting device ( 148 . 150 ) having a trained according to one of claims 5 to 9 lighting module, wherein the heat sink is a carrier housing. Lighting system having at least two mutually adjacent and according to claim 11 or 12 formed lighting devices ( 148 . 150 ), in which the heat sinks ( 24 ) of the at least two mutually adjacent lighting devices ( 148 . 150 ) through the opening ( 156 ) in the carrier housings ( 154 . 160 ) are connected through a thermal contact. Lighting system according to claim 13, characterized in that the thermal contact of the heat sink ( 24 ) by a between the heat sinks ( 206 . 208 ) arranged preferably as a copper plate ( 212 ) formed metal plate is effected. Lighting system according to claim 13 or 14, characterized in that an additional with the heat sink ( 206 . 208 ) a lighting device ( 202 . 204 ) thermally coupled heat sink ( 210 ) is provided.

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