Illumination apparatus for a medical imaging device, in particular an endoscope, exoscope and / or microscope

Abstract

The invention relates to an illumination apparatus (10a; 10b), in particular for a medical imaging device (11a) such as an endoscope, exoscope and / or microscope, comprising: - an illumination unit (14a; 14b) which comprises a group of illumination sources (16a, 18a, 36a, 38a, 62a; 16b, 18b, 36b, 38b, 62b) with a first illumination source (16a; 16b) and at least one second illumination source (18a; 18b) for the provision of at least one illumination, - a detector unit (80a; 80b) for determining at least one illumination property of the illumination, with the detector unit being arranged within the illumination apparatus in a beam path of the illumination light, and - a selection unit (60a; 60b) which is configured to allow illumination light of only a subgroup of the group of illumination sources (16a, 18a, 36a, 38a, 62a; 16b, 18b, 36b, 38b, 62b) onto at least one partial surface (70a; 70b) of a detector surface (72a; 72b) of the detector unit (80a; 80b).

Description

[0001] Illumination device for a medical imaging device, in particular an endoscope, exoscope and / or microscope

[0002] The present invention relates to a lighting device for a medical imaging device, such as an endoscope, exoscope and / or microscope, a medical imaging device, in particular an endoscopic, exoscopic and / or microscopic one, comprising such a lighting device and a method for operating a lighting device for a medical imaging device such as an endoscope, exoscope and / or microscope.

[0003] Imaging devices such as endoscopic or exoscopic devices that generate multispectral or hyperspectral images are known from the prior art. Multispectral or hyperspectral images have, in addition to two spatial dimensions, such as a conventional camera image, a spectral dimension. The spectral dimension encompasses several spectral bands (wavelength bands). Multispectral and hyperspectral images differ primarily in the number and width of their spectral bands.

[0004] Several imaging devices for generating such multispectral or hyperspectral images are known, particularly in the context of medical applications. For example, DE 20 2014 010 558 U1 describes a device for capturing a hyperspectral image of an examination region of a body. The device includes an input lens for generating an image in an image plane and a slit-shaped aperture in the image plane for masking out a slit-shaped region of the image. The light passing through the aperture is spread out by a dispersive element and recorded by a camera sensor. As a result, the camera sensor can record a plurality of spectra, each with an associated spatial coordinate, along the longitudinal direction of the slit-shaped aperture.The described device is further configured to record additional spectra along the longitudinal direction of the slit-shaped aperture in a direction different from the longitudinal direction of the slit-shaped aperture. The method underlying this disclosure for generating multispectral or hyperspectral images is also known as the so-called pushbroom method.

[0005] In addition to the pushbroom method, there are other methods for generating multispectral or hyperspectral images. In the so-called whiskbroom method, the examination area or object is scanned point by point, and a spectrum is obtained for each point. In contrast, the staring method acquires multiple images with the same spatial coordinates. Different spectral filters and / or illumination sources are used from image to image to resolve spectral information. Furthermore, there are methods in which a two-dimensional multicolor image is decomposed into several individual spectral images using suitable optical elements such as optical slicers, lenses, and prisms. These individual images are simultaneously acquired on different detectors or detector areas. This is sometimes referred to as the snapshot approach.

[0006] As described in DE 10 2020 105 458 A1, multispectral and hyperspectral imaging devices are particularly suitable as endoscopic imaging devices. In this context, multispectral and / or hyperspectral imaging is a fundamental field of application, for example, for diagnostics and for assessing the success or quality of a procedure.

[0007] White light imaging is also used, particularly in medical imaging. Observed tissue is illuminated with white light, and images of the tissue are generated using a camera or other image capture sensor, which can then be displayed to a user.

[0008] Fluorescence imaging is also used, especially in medical imaging. Tissue is specifically illuminated in a specific wavelength range to excite fluorescent dye molecules introduced into specific entities, such as tissue regions. The resulting emitted light at a longer wavelength can be observed through a suitably selected filter, which can filter out the excitation light.

[0009] Multimodal imaging devices allow the selective acquisition of white light images and / or multispectral images and / or fluorescence images and / or hyperspectral images. Examples of such imaging devices are multimodal endoscopes and multimodal exoscopes. To implement different modes, illumination devices may be required that can be operated in different illumination modes to generate illumination light in different spectral ranges as needed. US 10,481,095 B2 and US 11,668,922 B2 disclose illumination devices with multiple illumination sources, the light emitted by each of which can be combined using beam splitter elements.

[0010] Based on the prior art, the invention is based in particular but not limited to the object of providing reliable and efficient illumination of an examination area.

[0011] This object is achieved according to the invention by a lighting device, by a medical imaging device and by a method for operating a lighting device as described herein and defined in the claims.

[0012] The invention relates to a lighting device, in particular for a medical imaging device such as an endoscope, exoscope and / or microscope, comprising:

[0013] - a lighting unit which, for providing illumination light, has a group of illumination sources with a first illumination source and at least one second illumination source,

[0014] - a detector unit for determining at least one illumination property of the illumination light, wherein the detector unit is arranged within the illumination device in a beam path of the illumination light and

[0015] - a selection unit which is configured to supply illumination light only to a subgroup of the group of illumination sources of at least one partial area of ​​a detector area of ​​the detector unit.

[0016] The invention further relates to a method for operating a lighting device, in particular for a medical imaging device such as an endoscope, exoscope and / or microscope, comprising:

[0017] - a lighting unit which, for providing illumination light, has a group of illumination sources with a first illumination source and at least one second illumination source, and

[0018] - a detector unit for determining at least one illumination property of the illumination light, wherein the detector unit is arranged within the illumination device in a beam path of the illumination light, wherein illumination light is supplied to only a subgroup of the group of illumination sources in at least a partial region of the detector unit. The features according to the invention can provide reliable and efficient illumination of an examination region. In particular, advantageous operation in different modes can be enabled. A high degree of efficiency and / or operating reliability and simplicity can be achieved. By combining imaging modes or illumination sources used for this purpose, the complexity of the light source and / or image acquisition can be reduced.Furthermore, by automatically coordinating the operating state of the imaging device and the illumination mode, a high degree of user comfort can be achieved and operating errors can be avoided. This makes it possible to provide a multimodal system that can be easily switched between different modes. The detector unit in conjunction with the selection unit can advantageously increase the imaging, illumination, and / or evaluation quality. In particular, thermal influences on the illumination spectrum or spectra due to heating and / or aging of illumination sources and / or optical elements can be taken into account and / or compensated. This can improve white balance and / or correct an initial white balance.In addition, the selection unit can reduce costs, complexity and / or space requirements, since only one detector unit can be used for all illumination sources.

[0019] The illumination device can be part, in particular a subassembly, of a medical imaging device, in particular an endoscopic, exoscopic, and / or microscopic one. The imaging device can comprise a medical imaging device such as an endoscope, exoscope, and / or microscope, which can be supplied with output illumination provided by the illumination device via a light guide, which can also be part of the imaging device. The imaging device can be designed to provide at least a portion, preferably at least a majority, and particularly preferably substantially all of the output illumination for illuminating and / or illuminating an examination region.The imaging device, and in particular the illumination device, can be provided to provide light in a wavelength range from 100 nm to 1 mm, preferably from 200 nm to 1000 nm, and particularly preferably from 400 nm to 1000 nm, in the form of a broad, continuous spectrum or in the form of several separate partial spectra. The output illumination can be provided at an optical interface of the illumination device, wherein the light guide can be coupled to the optical interface. The optical interface can be fixed or optionally detachable and connectable. Furthermore, the optical interface can be combined with a mechanical interface, so that an optical connection is established automatically, for example, when the imaging device is mechanically coupled.

[0020] In some embodiments, the imaging device and in particular the imaging apparatus is configured to be insertable into a cavity for inspection and / or observation, for example, into an artificial and / or natural cavity, such as the interior of a body, a body organ, tissue, or the like. The imaging device and in particular the imaging apparatus can also be configured to be insertable into a housing, casing, shaft, pipe, or other, particularly artificial, structure for inspection and / or observation.

[0021] The imaging device and in particular the imaging apparatus can be configured to record tissue parameters, images of wounds, images of body parts, etc. For example, the imaging device can be configured to image a surgical field. The imaging device and / or the imaging apparatus can comprise a spatially and spectrally resolved image acquisition unit, which comprises at least one optical system and at least one image acquisition sensor coupled to the optical system, which is configured to perform an image acquisition of an image region, generating spatially and spectrally resolved image data that includes both spatial and spectral information.

[0022] The image acquisition unit and in particular the optics and / or the image acquisition sensors can be configured for multispectral and / or hyperspectral imaging, specifically for capturing and / or generating multispectral and / or hyperspectral image data. Multispectral imaging or multispectral image data can refer in particular to imaging in which at least two, in particular at least three, and in some cases at least five spectral bands can be and / or are captured independently of one another. Hyperspectral imaging or hyperspectral image data can refer in particular to imaging in which at least 20, at least 50, or even at least 100 spectral bands can be and / or are captured independently of one another.

[0023] In some embodiments, the imaging device and / or the imaging apparatus comprises a white-light camera and / or sensor technology for white-light image acquisition. The imaging device and / or the imaging apparatus can be configured for white-light imaging in addition to spectrally resolved imaging. Separate optics and / or shared optics can be used for this purpose. The white-light imaging and the spectrally resolved imaging can be performed simultaneously or alternately, or at times simultaneously and at times sequentially.

[0024] In some embodiments, the imaging device and / or the imaging apparatus comprises sensors for fluorescence imaging. The imaging device and / or the imaging apparatus can be configured for fluorescence imaging in addition to spectrally resolved imaging and, optionally, in addition to white-light imaging. Separate optics and / or shared optics can be used for this purpose. The fluorescence imaging, optionally the white-light imaging, and the spectrally resolved imaging can be performed simultaneously or alternately, or at times simultaneously and at times sequentially.

[0025] For some applications, it may be advantageous to be able to use a high spectral resolution. In these cases, hyperspectral imaging is a suitable option. This can be combined with white-light imaging and / or fluorescence imaging. This enables real-time observation via a white-light image and / or a fluorescence image, even if the acquisition of spectrally resolved image data is essentially only real-time, meaning that, for example, several seconds are required to create a spectrally resolved image.

[0026] For some applications, it may be advantageous to generate spectral image data in real time. This includes, for example, generating a spectrally resolved image in less than one second or even multiple times per second. In this case, it may be appropriate to use multispectral imaging. A potentially lower spectral resolution is then offset by a higher frame rate. Depending on the application, it may be sufficient to consider only a few different spectral ranges and / or wavelengths, for example, two, three, or four, or generally fewer than ten. In this case, additional white-light imaging can optionally be omitted.Spectrally resolved image data, which is acquired in real time or delivers several images per second, can also be used for surveillance purposes, whereby it is not necessarily necessary to create an image for a user to display, but the image data can also be processed in the background.

[0027] The imaging device may comprise a controller configured to automatically coordinate an operating state of the imaging device and an illumination mode of the illumination device, in particular of the illumination unit. The controller may be configured to control the illumination device and / or the imaging device.

[0028] In addition to the group of illumination sources, the illumination unit could comprise a further group of additional illumination sources. The illumination unit is provided, in particular by means of the group of illumination sources and / or the further group of additional illumination sources, for providing optical radiation, in particular in the wavelength range from 100 nm to 1 mm, preferably in the wavelength range from 200 nm to 1000 nm, and can comprise infrared radiation, visible light, and UV radiation.

[0029] The subset of the group of light sources can contain a single or multiple light sources. However, the subset of the group of light sources always contains fewer light sources than the group of light sources.

[0030] The optical radiation can be used to illuminate an examination area, for example with white light, and / or excitation radiation can be provided to excite a luminescent dye, preferably a fluorescent dye, such as cyanine 5.5 (Cy 5.5), indocyanine green (ICG), pafolacianin (OTL 38), PPIX, VisBlue, Vis-Red, NIR1, fluorescein or others that appear appropriate to a person skilled in the art.

[0031] Individual illumination sources of the illumination unit can be configured to emit optical radiation within a specific wavelength range and / or a specific radiation spectrum. The illumination sources are preferably all configured to emit optical radiation in different wavelength ranges and / or with different radiation spectra, with overlaps of the radiation spectra being conceivable. The illumination sources can be configured as any radiation sources deemed appropriate by a person skilled in the art, for example, vacuum lamps, LEDs, lasers, and / or laser diodes.For example, at least one of the illumination sources could be configured to emit red light, particularly in the wavelength range from 640 nm to 780 nm, at least one of the illumination sources could be configured to emit green light, particularly in the wavelength range from 490 nm to 570 nm, and / or at least one of the illumination sources could be configured to emit blue light, particularly in the wavelength range from 430 nm to 490 nm. Furthermore, at least one of the illumination sources could be configured to emit infrared radiation, particularly in the wavelength range from 780 nm to 1 mm, and / or at least one of the illumination sources could be configured to emit UV radiation, particularly in the wavelength range from 100 nm to 380 nm.

[0032] In addition, the lighting unit can have at least one optical element for beam shaping, beam splitting and / or beam combining, and / or beam deflection. The optical element can be provided to shape radiation provided by one or more of the illumination sources, in particular to focus an optical beam, and / or to split radiation provided by one or more of the illumination sources into two beam paths, or to combine two beams provided by at least two of the illumination sources and / or to deflect radiation provided by one or more of the illumination sources.

[0033] The illumination unit may comprise lenses, in particular converging lenses, as optical elements. The illumination unit may have beam splitter elements as optical elements. The beam splitter elements described herein may comprise bandpass filters, in particular notch filters, such that they each have a high reflectance and a low transmittance in a narrow spectral band or bands, but otherwise a high transmittance and a low reflectance, or vice versa. Alternatively or additionally, the beam splitter elements may comprise edge filters, such that they have a high reflectance and a low transmittance in a spectral band up to an edge, but otherwise a high transmittance and a low reflectance, or vice versa.The spectral position and / or width of the corresponding notch and / or the spectral position of the edge can be adapted to the spectral range of the respective associated illumination source or sources, so that its or their light can be largely redirected, but light from other illumination sources can be largely transmitted.

[0034] One of the beam splitter elements could be designed as an output beam splitter element upstream of the illumination output. The output beam splitter element can be the last beam splitter element in the beam direction upstream of the illumination output. The output beam splitter element can be designed as any optical element deemed appropriate by a person skilled in the art, but preferably as a semi-transparent mirror and / or an interference mirror or filter, preferably as a dichroic mirror and / or filter. The output beam splitter element can be provided to combine two beam paths and direct them toward the illumination output. One of the beams is transmitted through the output beam splitter element, while the other beam is reflected by the output beam splitter element.Transmission and reflection properties of the output beam splitter element can preferably be matched to spectra of the two beams in order to advantageously avoid radiation losses.

[0035] The output illumination at the illumination output consists at least partially of the illumination light provided by the illumination unit and may additionally include portions of additional illumination light from the illumination unit. The illumination device may optionally have a homogenizer upstream of the illumination output to homogenize the output illumination.

[0036] In some embodiments of the invention, the output beam splitter element

[0037] - either be designed to allow a large part of the intensity of an incoming illumination light to pass in the direction of the illumination output and to redirect a portion of the intensity of the illumination light in the direction of the detector unit, and to redirect a large part of the intensity of an incoming further illumination light in the direction of the illumination output and to allow a further portion of the intensity of the further illumination light to pass in the direction of the detector unit,

[0038] - or be designed to redirect a large portion of the intensity of the illumination light toward the illumination output and allow a portion of the intensity of the illumination light to pass toward the detector unit, as well as to allow a large portion of the intensity of the additional illumination light to pass toward the illumination output and redirect a further portion of the intensity of the additional illumination light toward the detector unit. The portion or the additional portion amounts to a maximum of 5%, preferably a maximum of 2%, and particularly preferably a maximum of 1% of the intensity of the illumination light or the additional illumination light.

[0039] The detector unit can comprise at least any optical detector deemed appropriate by a person skilled in the art, for example a photodiode, a phototransistor, a photoresistor, a CCD sensor, a CMOS sensor and / or a camera. The detector unit is arranged within the illumination device, for example in the same housing. Furthermore, the detector unit is arranged in a beam path of the illumination light. This means that illumination light from one or more illumination sources strikes the detector unit, partially or completely, as described above. For example, illumination light can be guided to the detector element after passing through a beam splitter element, in particular the output beam splitter element. The detector unit therefore serves to determine an illumination property in the illumination device itself.The detector unit is arranged in particular in front of the illumination output in the beam direction, wherein illumination light supplied to the detector unit is in particular not supplied to the illumination output. The illumination device can additionally be connected to the imaging device, in particular to the image acquisition unit, whereby feedback from the imaging device can be provided to the illumination device, in particular for white balance. The illumination property could now be an illumination spectrum, an illumination intensity, and / or an illumination power, and this illumination property determined as described could be used to improve the white balance.Preferably, the illumination property is a total radiant power of the output illumination, whereby thermal influences can be easily taken into account and / or compensated, not only with regard to the illumination sources, but also with regard to all other components, such as lenses or beam splitters, in an optical path of the illumination device, which each absorb and / or reflect certain light components. In particular, a white balance can be particularly easily improved and / or corrected, and the imaging, illumination, and / or evaluation quality can be enhanced.The selection unit can be configured to supply illumination light only to a subgroup of the group of illumination sources to at least one partial area of ​​a detector surface of the detector unit, either once at the beginning of an operating state or recurringly over time, in particular during a test operating state, or alternatively continuously over time, in particular during a continuous operating state. The continuous operating state can be interrupted recurringly over time, in particular periodically, by the test operating state.

[0040] The selection unit can be configured to supply illumination light of a first subgroup of the group of illumination sources to a first partial area of ​​the detector surface during a first time interval and a second subgroup of the group of illumination sources to a second partial area of ​​the detector surface during a second time interval. In some embodiments of the invention, the first partial area can be identical to the second partial area. In alternative embodiments of the invention, the first partial area can be different from the second partial area and preferably spatially spaced apart. Furthermore, in some embodiments of the invention, the first time interval can be identical to the second time interval. In alternative embodiments of the invention, the first time interval can be different from the second time interval and preferably spaced apart in time.Preferably, in some embodiments of the invention, the first partial area is identical to the second partial area, and the first time interval is different from the second time interval. Preferably, in alternative embodiments of the invention, the first partial area is different from the second partial area, and the first time interval is identical to the second time interval.

[0041] In addition, different illumination sources can belong to the first subgroup and the second subgroup, wherein preferably each illumination source can be assigned to exactly one subgroup, in particular to the first, the second or a further subgroup.

[0042] In a preferred embodiment of the invention, the subgroup and / or the further subgroup can comprise exactly one illumination source, whereby monitoring can be advantageously simplified.

[0043] If objects are named, in particular, using numerical terms such as "first," "second," "third," etc., these serve to name and / or assign objects. Thus, for example, a first object and a third object may be included, but not a second object. "Intended" should be understood as specifically designed and / or programmed, not merely as mere suitability.

[0044] In some embodiments, the partial area can be smaller than the detector area, whereby several partial areas, each smaller than the detector area, are available simultaneously to simultaneously supply illumination light from several subgroups of the group of illumination elements to the detector area. This can, in particular, enable continuous monitoring of the illumination unit. The partial areas can, in particular, be arranged next to one another and without overlapping, preferably in a pattern, on the detector area. Each partial area can be assigned a subgroup of illumination sources or, preferably, exactly one illumination source.

[0045] In alternative embodiments, however, the partial area can also correspond at least substantially to the detector area, which can advantageously increase the reliability of monitoring the lighting unit. The partial area can correspond to at least 75%, in particular at least 85%, and preferably at least 95% of the detector area. Particularly preferably, the partial area is identical to the detector area.

[0046] The selection unit can comprise a filter unit arranged upstream of the detector unit in the beam direction. This allows chromatic filtering to be achieved. The filter unit could, for example, comprise at least one chromatically variable filter element for adjusting a transmission wavelength range. In another embodiment, the filter unit could also comprise at least one dispersive element, in particular a prism, for spectral splitting.

[0047] The filter unit can preferably have a plurality of individual filter elements, thereby providing a structurally simple filter unit. The filter elements could be designed as individual chromatic filters, each having a high transmittance in a specific wavelength range and a low transmittance otherwise. The filter elements could be arranged in a pattern on a filter plate of the filter unit or along a circumferential direction on a rotatable filter wheel of the filter unit. In the case of a filter wheel, this could, by rotation, only allow light from a specific subgroup of the illumination sources to reach the detector surface. The filter elements could have a polygonal, in particular rectangular, or oval, in particular circular, shape.

[0048] Advantageously, the filter unit can have at least one dedicated filter element for each of the illumination sources of the illumination unit, which filter element at least partially allows illumination light from the associated illumination source to pass through. This can advantageously simplify monitoring of the illumination unit. Furthermore, continuous monitoring of the illumination unit can be enabled. To ensure that the filter elements essentially only allow light from the respectively assigned illumination source to pass through, the filter elements can preferably be designed to be relatively narrow-band. The filter elements are preferably designed to overlap one another in the wavelength space. The filter elements can be provided to allow an intensity component of at least 75%, in particular of at least 85% and preferably of at least 95% of the respectively assigned illumination source to pass through to the detector surface.The lighting unit can have a special filter for at least one of the lighting sources, which can cut out a partial area from a lighting spectrum of the respective lighting source, wherein light from this partial area can be at least substantially transmitted through the associated dedicated filter element, in particular to at least 75%, in particular to at least 85% and preferably to at least 95%.

[0049] Furthermore, each filter element can be assigned a partial area of ​​the detector surface, which preferably enables simultaneous monitoring of several and preferably all illumination sources of the illumination unit. The filter elements can preferably be arranged next to one another in a pattern, in particular in a matrix-like manner, so that the filter unit can form a filter array. The partial areas of the detector surfaces are preferably arranged next to one another and without overlap. The selection unit can be configured to assign a subgroup of the illumination sources, and preferably exactly one of the illumination sources, to each partial area.

[0050] In some embodiments, the selection unit may comprise a control unit which is configured to operate at least one illumination source and preferably all illumination sources of the subgroup in isolation from other illumination sources of the illumination unit in at least one operating state, which may in particular be a test step of a test operating state, and to supply illumination light from the illumination sources of the subgroup to the detector surface.In this case, the control unit can be set up to operate at least one illumination source and preferably all illumination sources of a further subgroup of the group of illumination sources in isolation from other illumination sources of the illumination unit in at least one further operating state, which can in particular be a further test step of the test operating state, and to supply illumination light from the illumination sources of the further subgroup to the detector surface. In this way, monitoring with regard to a power measurement can be advantageously improved, since although a measurement for the individual subgroups must be carried out one after the other in several test steps, the measured radiant power can be clearly assigned to one of the subgroups of the illumination sources and preferably to exactly one illumination source.

[0051] The control unit is particularly configured to activate the at least one operating state and the at least one further operating state sequentially. The at least one operating state can be activated depending on a frame rate of the imaging device, for example, synchronized with it.

[0052] The at least one and / or the at least one further operating state are active for less than one second, in particular each and also together.

[0053] Preferably, each of the operating states of the illumination sources is activated sequentially. Furthermore, each of the operating states can be activated sequentially within a period of one second or less, in particular individually and also together. In particular, the operating states can all be active for less than one second individually and also in total.

[0054] The test step / operating state and the subsequent test step / operating state can therefore run sequentially. The test step and / or the subsequent test step can have a duration of less than 1 s, in particular a maximum of 100 ms and preferably a maximum of 75 ms. For example, with five illumination sources and an imaging device frame rate of 60 frames / s, the illumination unit could be adapted to the imaging device, whereby each of the light sources could be switched off for four frames (67 ms) within each second and, for example, activated for the remainder of the time.The light sources are deactivated and activated one after the other in time, so that in the test step / relevant operating state only one light source is active and the others are deactivated, so that the illuminating light hits the detector unit located in a beam path of the illuminating light and the illuminating property of the illuminating source (LED) can be determined.

[0055] In this way, the lighting properties of the light sources can be determined individually without having to impair the lighting for long periods. At the same time, the lighting properties of the light sources can be determined almost in real time.

[0056] In some embodiments, the detector unit can have a camera sensor that defines the detector surface, which preferably allows continuous monitoring of the illumination unit by assigning different sub-areas of the detector surface to different subgroups of illumination sources or to different illumination sources. The camera sensor can be designed as a CCD sensor or a CMOS sensor.

[0057] In alternative embodiments, the detector unit can have at least one photodiode, one phototransistor or one photoresistor or even several of the aforementioned elements, which define(s) the detector surface at least in sections, thereby advantageously achieving low costs. A photodiode, one phototransistor or one photoresistor is particularly suitable for monitoring the illumination unit, in which certain subgroups of the illumination sources are successively directed onto the entire detector surface. A plurality of photodiodes, phototransistors or photoresistors could, for example, be used in conjunction with the aforementioned plurality of filter elements, wherein each of the filter elements could be assigned at least one photodiode, at least one phototransistor or at least one photoresistor.

[0058] The devices, units, and systems according to the invention are not intended to be limited to the application and embodiment described above. In particular, to fulfill a functionality described herein, they may have a number of individual elements, components, and units that differs from the number stated herein. Furthermore, in the value ranges specified in this disclosure, values ​​within the stated limits are also to be considered disclosed and can be used arbitrarily. The present invention is described below by way of example with reference to the attached figures. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and use them meaningfully in combination within the scope of the claims.

[0059] If more than one example of a particular object exists, only one of them is provided with a reference symbol in the figures and in the description. The description of this example can be applied accordingly to the other examples of the object.

[0060] They show:

[0061] Fig. 1 shows a medical imaging device with an imaging device in the form of an endoscope and with a lighting device connected to the endoscope,

[0062] Fig. 2 is a schematic representation of the lighting device,

[0063] Fig. 3 is a schematic representation of a beam path of the illumination device,

[0064] Fig. 4 an explanatory diagram of the beam path,

[0065] Fig. 5 diagrams for explaining a method for operating the lighting device,

[0066] Fig. 6 is a schematic representation of a beam path of a lighting device of an alternative embodiment,

[0067] Fig. 7 shows a filter unit of the lighting device from Fig. 6 in a plan view,

[0068] Fig. 8 is a diagram of illumination spectra of illumination sources of a lighting unit of the lighting device from Fig. 6 and Fig. 9 is the diagram from Fig. 8 with marked filter areas of filter elements of the filter unit from Fig. 7.

[0069] Fig. 1 shows a schematic representation of a medical imaging device 12a. In the exemplary case shown, the imaging device 12a is an endoscopic medical imaging device. Alternatively, the medical imaging device 12a could be an exoscopic, microscopic, or macroscopic medical imaging device. The imaging device 12a is intended, for example, for examining a cavity 86a.

[0070] The imaging device 12a comprises a medical imaging device 11a. In the illustrated case, this is an endoscope that can be partially inserted into the cavity 86a.

[0071] The imaging device 12a comprises an illumination device 10a with an optical interface 21a. The imaging device 11a can be optically connected to the optical interface 21a. The optical interface 21a can be part of an optical-mechanical interface that can be selectively connected and detachable. The imaging device 11a can be selectively decoupled from the illumination device 10a.

[0072] The illumination device 10a is provided for providing output illumination at an illumination output 20a, which has the optical interface 21a. The output illumination can be fed to the imaging device 11a via a light guide 22a of the imaging device 12a. The imaging device 11a couples the output illumination onto an object to be imaged, such as a site.

[0073] In the illustrated case, the imaging device 12a further comprises a display unit 88a, on which images based on image data acquired by the imaging device 11a can be displayed. These can be video images, still images, overlays of different images, partial images, image sequences, etc.

[0074] The imaging device 12a is multimodal. By way of example, the imaging device can be operated in three basic modes: a multispectral mode, a fluorescence mode, and a white light mode. Furthermore, it can be provided that the imaging device 12a can be operated in a hyperspectral mode in addition to or alternatively to the multispectral mode. The illumination device 10a is multimodal. The illumination device 10a can be operated in different illumination modes, in which it provides light for different imaging modes. In the present case, the illumination device 10a can be operated in three basic modes: a multispectral mode, a fluorescence mode, and a white light mode. Likewise, the imaging device 11a can be operated in different operating modes, specifically also in at least one multispectral mode, one fluorescence mode, and one white light mode.In the corresponding operating mode of the imaging device 12a, the modes of the illumination device 10a and / or the imaging device 11a are coordinated with one another by a control of the imaging device 12a.

[0075] Fig. 2 shows a schematic representation of the lighting device 10a. The lighting device 10a comprises a lighting unit 14a, which has a group of lighting sources 16a, 18a, 36a, 38a, 62a for providing at least one illumination light.

[0076] The lighting unit 14a has a first illumination source 16a, a second illumination source 18a, a third illumination source 36a, a fourth illumination source 38a, and a fifth illumination source 62a. Alternatively, the lighting unit 14a could also have more or fewer illumination sources 16a, 18a, 36a, 38a, 62a, but at least two.

[0077] The first illumination source 16a is designed as an LED. The first illumination source 16a is designed to emit narrowband light with a mean wavelength of 460 nm.

[0078] The second illumination source 18a is designed as an LED. The second illumination source 18a is designed to emit narrowband light with a mean wavelength of 660 nm.

[0079] The third illumination source 36a is designed as an LED. The third illumination source 36a is designed to emit narrowband infrared radiation with a mean wavelength of 940 nm. The fourth illumination source 38a is designed as an LED. The fourth illumination source 38a is designed to emit narrowband light with a mean wavelength of 770 nm.

[0080] The fifth illumination source 62a is configured as an LED or, alternatively, as a laser diode. The fifth illumination source 62a is designed to emit light with a mean wavelength of 560 nm.

[0081] The illumination sources 16a, 18a, 36a, 38a, 62a can be activated independently of one another or in groups to implement the different operating modes. The first illumination source 16a, the second illumination source 18a, the fourth illumination source 38a, and the fifth illumination source 62a are designed to emit white light together in the white light mode and / or in the multispectral mode. The third illumination source 36a and / or the fifth illumination source 62a are designed to emit excitation radiation for exciting a fluorescent dye in at least one fluorescence mode and / or in the multispectral mode.

[0082] In alternative embodiments, other mean wavelengths and / or bandwidths and / or spectra for the illumination sources 16a, 18a, 36a, 38a, 62a would also be conceivable.

[0083] The lighting device 10a comprises a detector unit 80a for determining at least one lighting property of the output lighting, namely its total radiant power.

[0084] The illumination device 10a has an output beam splitter element 66a, which is provided to combine a part of an illumination light provided by the illumination sources 16a, 18a, 36a, 38a and a part of a further illumination light provided by the fifth illumination source 62a to form the output illumination.

[0085] The output beam splitter element 66a is provided to allow a large portion of the intensity of the illumination light to pass in the direction of the illumination output 20a and to redirect a maximum of 1% of the intensity of the illumination light in the direction of the detector unit 80a, as well as to redirect a large portion of the intensity of the further illumination light in the direction of the illumination output 20a and to allow a further portion of a maximum of 1% of the intensity of the further illumination light to pass in the direction of the detector unit 80a.

[0086] For this purpose, the output beam splitter element 66a has a bandpass filter which has a high transmittance and a low reflectance between 500 nm and 620 nm and otherwise has a high reflectance and a low transmittance.

[0087] The illumination device 10a has a focus lens 84a located behind the output beam splitter element 66a in the direction of the illumination output 20a. The focus lens 84a focuses the output illumination supplied to the illumination output 20a. The illumination device 10a may additionally have a homogenizer 82a, for example in the form of a homogenizer rod, for homogenizing the output illumination in front of the illumination output 20a, but this is not required.

[0088] The illumination device 10a has an optical path 24a, 26a, 54a, 90a for the illumination sources 16a, 18a, 36a, 38a, which extends from the respective illumination source 16a, 18a, 36a, 38a to the illumination output 20a.

[0089] A first optical path 24a extends from the first illumination source 16a to the illumination output 20a and comprises exactly three optical beam shaping elements 28a, 32a, 34a.

[0090] A second optical path 26a extends from the second illumination source 18a to the illumination output 20a and comprises exactly three optical beam shaping elements 30a, 32a, 34a.

[0091] A third optical path 54a extends from the third illumination source 36a to the illumination output 20a and comprises exactly three optical beam shaping elements 34a, 40a, 42a.

[0092] A fourth optical path 90a extends from the fourth illumination source 38a to the illumination output 20a and comprises exactly three optical beam-shaping elements 32a, 34a, 92a. Thus, all optical paths 24a, 26a, 54a, 90a from the illumination sources 16a, 18a, 36a, 38a to the illumination output 20a each comprise exactly three optical beam-shaping elements 28a, 30a, 32a, 34a, 40a, 42a, 92a.

[0093] The optical beam-shaping elements 28a, 30a, 40a, 92a are designed as condenser lenses 48a, 50a, 56a, 94a, namely a first condenser lens 48a spaced by a distance L1 from the first illumination source 16a, a second condenser lens 50a spaced by a distance L1 from the second illumination source 18a, a third condenser lens 56a spaced by a distance L1' from the third illumination source 36a, and a fourth condenser lens 94a spaced by a distance L1 from the fourth illumination source 38a. The first condenser lens 48a, the second condenser lens 50a, and the fourth condenser lens 94a are identical to one another. The third condenser lens 56 differs from the first condenser lens 48a, the second condenser lens 50a and the fourth condenser lens 94a, also with respect to a distance L1 ' to the associated illumination source 36a.In alternative embodiments, L1 ' = L1 could apply and the third condenser lens 56a could be designed identically to the other condenser lenses 48a, 50a, 94a.

[0094] The optical beamforming element 32a is formed as a common compensator lens 52a, which is common to the first optical path 24a, the second optical path 26a and the fourth optical path 90a.

[0095] The optical beamforming element 42a is designed as a dedicated compensator lens 58a, which is solely part of the third optical path 54a.

[0096] The optical beam shaping element 34a is designed as the focus lens 84a and is common to all optical paths 24a, 26a, 54a, 90a.

[0097] The illumination device 10a has three beam splitter elements 44a, 46a, 98a, each of which is provided to couple one of the illumination sources 18a, 36a, 38a of the illumination unit 14a into a beam path emanating from the illumination source 16a in the direction of the illumination output 20a.

[0098] The beam splitter element 44a is part of the first optical path 24a and the second optical path 26a. The beam splitter element 44a is spaced a distance L2 from the first condenser lens 48a and the second condenser lens 50a, respectively. The beam splitter element 44a has an edge filter with an edge that lies in the wavelength space between a wavelength range emitted by the first illumination source 16a and a wavelength range emitted by the second illumination source 18a, for example, at 540 nm.

[0099] The beam splitter element 46a is part of the first optical path 24a, the second optical path 26a, and the third optical path 54a. The beam splitter element 46a is spaced a distance L4 from the fourth condenser lens 94a. The beam splitter element 46a has an edge filter with an edge that lies in the wavelength space between a wavelength range emitted by the first illumination source 16a and the second illumination source 18a and a wavelength range emitted by the fourth illumination source 38a, for example, at 700 nm.

[0100] The beam splitter element 98a is part of the first optical path 24a, the second optical path 26a, the third optical path 54a, and the fourth optical path 90a. The beam splitter element 46a has an edge filter with an edge that lies in the wavelength space between a wavelength range emitted by the first illumination source 16a, the second illumination source 18a, and the fourth illumination source 38a and a wavelength range emitted by the third illumination source 36a, for example, at 840 nm.

[0101] The beam splitter elements 44a, 46a are optically arranged directly one behind the other and spaced apart by a distance L3. The common compensator lens 52a is arranged optically between the beam splitter element 46a and the beam splitter element 98a.

[0102] The output beam splitter element 66a and, if applicable, the homogenizer 82a are part of the first optical path 24a, the second optical path 26a, the third optical path 54a, and the fourth optical path 90a. The beam splitter element 98a and the output beam splitter element 66a are arranged optically directly one behind the other.

[0103] The first optical path 24a, the second optical path 26a and the fourth optical path 90a are of equal length, since the following relationship applies between the distances L2, L3 and L4: L4 = L2 + L3

[0104] The first optical path 24a, the second optical path 26a, and the fourth optical path 90a also have the same optical beamforming elements 28a, 30a, 32a, 34a, and 92a. The first optical path 24a, the second optical path 26a, and the fourth optical path 90a are thus identical to one another.

[0105] The third optical path 54a differs from the first optical path 24a, the second optical path 26a, and the fourth optical path 90a. The third optical path 54a uses the dedicated compensator lens 58a instead of the common compensator lens 52a.

[0106] For the illumination sources 16a, 18a, 36a, 38a, this results in a fundamentally similar beam path to the illumination output 20a (except for partially different path lengths and optical components). This is sketched as an example for the first illumination source 16a in Fig. 3 and Fig. 4: The beam path for each of the illumination sources 16a, 18a, 36a, 38a always runs via the condenser lens 48a, 50a, 56a, 94a assigned to it, via a compensator lens, namely the common compensator lens 52a or the dedicated compensator lens 58a, and via the focus lens 84a.

[0107] The illumination device 10a has a fifth optical path 64a for the fifth illumination source 62a, which extends from the fifth illumination source 62a to the illumination output 20a. The fifth optical path 64a comprises exactly two optical beam-shaping elements 34a, 68a.

[0108] The optical beam-shaping element 68a is configured as a fifth condenser lens 96a. The fifth condenser lens 96a differs from the first condenser lens 48a, the second condenser lens 50a, the third condenser lens 56a, and the fourth condenser lens 94a, but could also be identical in alternative embodiments.

[0109] The optical beam-shaping element 34a is again designed as the focus lens 84 and is shared by the optical paths 24a, 26a, 54a, and 90a. Since the fifth illumination source 62a is relatively strong and the fifth optical path 64a is relatively short, a compensator lens can be omitted in the fifth optical path 64a. The beam losses are manageable here.

[0110] The fifth optical path 64a also includes the output beam splitter element 66a and optionally the homogenizer 82a.

[0111] The illumination device 10a comprises a selection unit 60a (see Fig. 2), which is configured to direct illumination light from only a subgroup of the group of illumination sources 16a, 18a, 36a, 38a, 62a onto at least a partial area of ​​a detector surface of the detector unit 80a. The partial area 70a corresponds to the entire detector surface 72a. The detector unit 80a has a photodiode 91a, which completely defines the detector surface 72a.

[0112] The selection unit 60a has a control unit 83a which is configured to operate all illumination sources 16a, 18a, 36a, 38a, 62a of the subgroup in isolation from other illumination sources 16a, 18a, 36a, 38a, 62a of the illumination unit 14a in at least one operating state corresponding to a first test step of a test operating state and to allow illumination light from the illumination sources 16a, 18a, 36a, 38a, 62a of the subgroup onto the detector surface 72a.Furthermore, the control unit 83a is configured, in at least one further operating state, which corresponds to a second test step of the test operating state, to operate all illumination sources 16a, 18a, 36a, 38a, 62a of a further subgroup of the group of illumination sources 16a, 18a, 36a, 38a, 62a in isolation from other illumination sources 16a, 18a, 36a, 38a, 62a of the illumination unit 14a and to allow illumination light from the illumination sources 16a, 18a, 36a, 38a, 62a of the further subgroup onto the detector surface 74a.

[0113] In the present case, the subgroup and the further subgroup each have exactly one of the illumination sources 16a, 18a, 36a, 38a, 62a, and indeed different ones. However, in alternative embodiments, it would also be conceivable for the subgroup and / or the further subgroup to have two or more of the illumination sources 16a, 18a, 36a, 38a, 62a.

[0114] The control unit 83a is integrated into the control system of the imaging device 12. The control unit 83a controls the illumination sources 16a, 18a, 36a, 38a, 62a and the detector unit 80a accordingly to determine a total radiant power provided by the individual illumination sources 16a, 18a, 36a, 38a, 62a at the illumination output 20a (for the sake of clarity, lines of action between the control unit 83a and the individual illumination sources 16a, 18a, 36a, 38a, 62a are not shown in Fig. 2).

[0115] Fig. 5 shows diagrams to explain a method for operating the lighting device 10a, which is carried out by the control unit 83a. To determine the total radiant power provided by the individual lighting sources 16a, 18a, 36a, 38a, 62a at the lighting output 20a, the control unit 83a sequentially controls the lighting sources 16a, 18a, 36a, 38a, 62a in the test operating state, so that at any given time only one of the lighting sources 16a, 18a, 36a, 38a, 62a is active and, consequently, only its light can reach the detector unit 80a. The five illumination sources shown in Fig.The characteristic curves shown one above the other in Figure 5 each represent the power applied to the illumination sources 16a, 18a, 36a, 38a, 62a, wherein the first illumination source 16a is active during a time interval Ti, the second illumination source 18a during a time interval T2, the third illumination source 36a during a time interval T3, the fourth illumination source 38a during a time interval T4, and the fifth illumination source 62a during a time interval Ts, each of which is active on its own and provides the output illumination at the illumination output 20a during the respective time interval. The time intervals Ti, T2, T3, T4, and Ts can be of equal or different lengths. The time intervals Ti, T2, T3, T4, and Ts immediately follow one another. The time intervals Ti, T2, T3, T4, and Ts have a length of well under one second, for example, a maximum of 0.1 s.

[0116] The test operating state is carried out repeatedly in order to ensure stable operation of the lighting device 10a.

[0117] 6 to 9 show a further exemplary embodiment of the invention. The following description is essentially limited to the differences between the exemplary embodiments. With regard to structural units and components with the same reference numerals, reference can generally be made to the description of the first exemplary embodiment in FIGS. 1 to 5. For differentiation, the reference numerals of the exemplary embodiments in FIGS. 6 to 9 are followed by the letter "b" instead of the letter "a" in the exemplary embodiment in FIGS. 1 to 5. Fig. 6 shows a modified variant of an illumination device 10b compared to the previous exemplary embodiment, in which the positions of an illumination output 20b and a detector unit 80b are reversed.

[0118] Accordingly, an output beam splitter element 66b of the illumination device 10b is provided to redirect a large portion of the intensity of an illumination light provided by illumination sources 16b, 18b, 36b, 38b toward the illumination output 20b and to allow a maximum of 1% of the intensity of the illumination light to pass toward the detector unit 80b, as well as to allow a large portion of the intensity of a further illumination light provided by a fifth illumination source 62b to pass toward the illumination output 20b and to redirect a further portion of a maximum of 1% of the intensity of the further illumination toward the detector unit 80b. Accordingly, the transmission and reflection properties of the output beam splitter element 66b are exactly the opposite of those in the previous embodiment.

[0119] This arrangement may allow certain requirements regarding space utilization and / or cooling to be better met.

[0120] The illumination device 10b comprises a selection unit 60b, which is configured to direct illumination light from only a subgroup of the group of illumination sources 16b, 18b, 36b, 38b, 62b onto at least a partial area of ​​a detector surface of the detector unit 80a in a continuous operating state. The partial area 70b is smaller than the detector surface 72a (see Fig. 7). The detector unit 80b has a camera sensor 89b, specifically a CMOS sensor in this case, which defines the detector surface 72b.

[0121] The selection unit 60b has a filter unit 74b, which is arranged in front of the detector unit 80b in the beam direction. The filter unit 74b is shown in more detail in Fig. 7. The filter unit 74b is designed as a filter plate, which is arranged in front of the detector unit 80b. The filter unit 74b partially or completely covers the detector surface 72b. In the present case, the detector surface 72b is slightly larger than the filter unit 74b. The filter unit 74b has a plurality of individual filter elements 75b, 76b, 77b, 78b, 79b, wherein the filter unit 74b has a dedicated filter element 75b, 76b, 77b, 78b, 79b for each of the illumination sources 16b, 18b, 36b, 38b, 62b of the illumination unit 14b, which allows illumination light of the associated illumination source 16b, 18b, 36b, 38b, 62b to pass through at least partially.

[0122] A first filter element 75b is assigned to the first illumination source 16b. A second filter element 76b is assigned to the second illumination source 18b. A third filter element 77b is assigned to the third illumination source 36b. A fourth filter element 78b is assigned to the fourth illumination source 38b. A fifth filter element 79b is assigned to the fifth illumination source 62b.

[0123] Each of the filter elements 75b, 76b, 77b, 78b, 79b is assigned a partial area 70b of the detector surface 72b (in Fig. 7, only one of the partial areas 70b is provided with a reference symbol). From the radiation power incident on the partial areas 70b, a controller of the imaging device 12b can deduce the total radiation power of the respectively assigned illumination source 16b, 18b, 36b, 38b, 62b.

[0124] In this embodiment, continuous monitoring of the lighting device 10b can be ensured to ensure stable operation of the lighting device 10b.

[0125] To ensure that the filter elements 75b, 76b, 77b, 78b, 79b provide a clean separation between the illumination sources 16b, 18b, 36b, 38b, 62b, the filter elements 75b, 76b, 77b, 78b, 79b are only transmissive in a narrow wavelength range. This is explained below with reference to Figs. 8 and 9.

[0126] Figure 8 shows a diagram of the five illumination spectra 63b, 65b of the illumination sources 16b, 18b, 36b, 38b, and 62b (for clarity, the illumination spectra of the illumination sources 16b, 18b, 36b, and 38b are provided with the same reference symbol). A relative radiant power is plotted on a vertical axis. A wavelength is plotted on a horizontal axis. The illumination spectra 63b, 65b are shown with different dashed lines. As can be seen from the figure, the illumination spectra 63b, 65b partially overlap. In particular, the illumination spectrum 65b of the illumination source 62b is relatively broadband. In order to reduce overlap with the illumination spectra 63b of the other illumination sources 16b, 18b, 36b, 38b, a filter 81b is provided behind the illumination source 62b (cf. Fig. 6), which blocks the illumination spectrum 65b below 500 nm and above 620 nm (cf. Fig. 8).The filter 81b is adapted to the output beam splitter element 66b with regard to its transmission and reflection properties.

[0127] Fig. 9 shows the diagram from Fig. 8 with the filter regions 67b of the filter elements 75b, 76b, 77b, 78b, 79b of the filter unit 74b indicated. For the sake of clarity, only one of the filter regions 67b is provided with a reference numeral. The filter elements 75b, 76b, 77b, 78b, 79b are relatively narrow-band and cut out narrow regions from the illumination spectra of the individual illumination spectra 63b, 65b, which, in particular, allow for unambiguous assignment to the associated illumination sources 16b, 18b, 36b, 38b, 62b. For this purpose, the filter regions 67b overlap one another without overlapping.

[0128] List of reference symbols

[0129] 10 Lighting device

[0130] 11 Imaging device

[0131] 12 Imaging device

[0132] 14 Lighting unit

[0133] 16 first light source

[0134] 18 second lighting source

[0135] 20 Lighting output

[0136] 21 optical interface

[0137] 22 light guides

[0138] 24 first optical path

[0139] 26 second optical path

[0140] 28 optical beam shaping element

[0141] 30 optical beam shaping element

[0142] 32 optical beam shaping element

[0143] 34 optical beam shaping element

[0144] 36 third lighting source

[0145] 38 fourth illumination source

[0146] 40 optical beam shaping element

[0147] 42 optical beam shaping element

[0148] 44 beam splitter element

[0149] 46 beam splitter element

[0150] 48 first condenser lens

[0151] 50 second condenser lens

[0152] 52 common compensator lens

[0153] 54 third optical path

[0154] 56 third condenser lens

[0155] 58 dedicated compensator lens

[0156] 60 selection unit

[0157] 62 fifth source of illumination

[0158] 63 Lighting spectrum

[0159] 64 fifth optical path

[0160] 65 lighting spectrum

[0161] 66 Output beam splitter element

[0162] 67 filter area 68 optical beam shaping element

[0163] 70 subareas

[0164] 72 detector area

[0165] 74 Filter unit

[0166] 75 first filter element

[0167] 76 second filter element

[0168] 11 third filter element

[0169] 78 fourth filter element

[0170] 79 fifth filter element

[0171] 80 detector unit

[0172] 81 filters

[0173] 82 Homogenizer

[0174] 83 Control unit

[0175] 84 Focus lens

[0176] 86 Cavity

[0177] 88 display unit

[0178] 89 camera sensor

[0179] 90 fourth optical path

[0180] 91 photodiode

[0181] 92 optical beam shaping element

[0182] 94 fourth condenser lens

[0183] 96 fifth condenser lens

[0184] 98 beam splitter element

[0185] FE

Claims

Claims 1 . Illumination device (10a; 10b) for a medical imaging device (11a) such as an endoscope, exoscope and / or microscope comprising: - a lighting unit (14a; 14b) which, for providing illumination light, has a group of illumination sources (16a, 18a, 36a, 38a, 62a; 16b, 18b, 36b, 38b, 62b) with a first illumination source (16a; 16b) and at least one second illumination source (18a; 18b), - a detector unit (80a; 80b) for determining at least one illumination property of the illumination light, wherein the detector unit is arranged within the illumination device in a beam path of the illumination light, and - a selection unit (60a; 60b) which is designed to supply illumination light only to a subgroup of the group of illumination sources (16a, 18a, 36a, 38a, 62a; 16b, 18b, 36b, 38b, 62b) of at least one partial area (70b) of a detector area (72b) of the detector unit (80a; 80b).

2. Lighting device (10b) according to one of the preceding claims, wherein the selection unit (60b) has a filter unit (74b) which is arranged in front of the detector unit (80b) in the beam direction.

3. Lighting device (10b) according to claim 2, wherein the filter unit (74b) comprises a plurality of individual filter elements (75b, 76b, 77b, 78b, 79b).

4. Lighting device (10b) according to claim 2 or 3, wherein the filter unit (74b) has at least one dedicated filter element (75b, 76b, 77b, 78b, 79b) for each of the illumination sources (16b, 18b, 36b, 38b, 62b) of the lighting unit (14b), which allows illumination light of the associated illumination source (16b, 18b, 36b, 38b, 62b) to pass through at least partially.

5. Lighting device (10b) according to claim 3 or 4, wherein each filter element (75b, 76b, 77b, 78b, 79b) is assigned a partial area (70b) of the detector area (72b).

6. Lighting device (10a) according to one of the preceding claims, wherein the selection unit (60a) has a control unit (83a) which is is arranged, in at least one operating state, to operate at least one illumination source (16a, 18a, 36a, 38a, 62a) and preferably all illumination sources (16a, 18a, 36a, 38a, 62a) of the sub-group in isolation from other illumination sources (16a, 18a, 36a, 38a, 62a) of the illumination unit (14a) and to supply illumination light from the illumination source or illumination sources (16a, 18a, 36a, 38a, 62a) of the sub-group to the detector surface (72a).

7. Lighting device (10a) according to claim 6, wherein the control unit (83a) is configured to operate, in at least one further operating state, at least one illumination source (16a, 18a, 36a, 38a, 62a) and preferably all illumination sources (16a, 18a, 36a, 38a, 62a) of a further subgroup of the group of illumination sources (16a, 18a, 36a, 38a, 62a) in isolation from other illumination sources (16a, 18a, 36a, 38a, 62a) of the lighting unit (14a) and to supply illumination light of the illumination source or illumination sources (16a, 18a, 36a, 38a, 62a) of the further subgroup to the detector surface (74a).

8. Lighting device (10a) according to claim 7, wherein the control unit (83a) is configured to activate the at least one operating state and the at least one further operating state sequentially in time.

9. Lighting device (10a) according to one of claims 6 to 8, wherein the control unit (83a) is configured to activate the at least one operating state as a function of a frame rate of the imaging device (11a).

10. Lighting device (10a) according to one of claims 6 to 9, wherein the at least one and / or the at least one further operating state are active for less than one second.

11. Lighting device (10a) according to one of claims 7 to 10, wherein each of the operating states is activated sequentially.

12. Lighting device (10a) according to one of claims 7 to 11, wherein each of the operating states is activated sequentially within a period of one second or less.

13. Lighting device (10b) according to one of the preceding claims, wherein the detector unit (80b) has a camera sensor (89b) which defines the detector surface (72b).

14. Lighting device (10a) according to one of claims 1 to 12, wherein the detector unit (80a) has at least one photodiode (91a), a phototransistor or a photoresistor, which defines the detector surface (72a) at least in sections.

15. Lighting device (10a; 10b) according to one of the preceding claims, further comprising: - an illumination output (20a; 20b) which has an optical interface (21a) and is intended to provide an output illumination which is at least partially formed by the illumination light, wherein the illumination property is at least one illumination property of the output illumination, preferably a total radiant power of the output illumination.

16. Lighting device (10a; 10b) according to one of the preceding claims, wherein the subgroup and / or the further subgroup comprises exactly one illumination source (16a, 18a, 36a, 38a, 62a; 16b, 18b, 36b, 38b, 62b).

17. Medical imaging device (12a), in particular endoscopic, exoscopic and / or microscopic medical imaging device, with an illumination device (10a; 10b) according to one of the preceding claims.

18. A method for operating a lighting device (10a; 10b) for a medical imaging device (11a) such as an endoscope, exoscope and / or microscope, in particular according to one of claims 1 to 16, comprising: - a lighting unit (14a) which, for providing illumination light, has a group of illumination sources (16a, 18a, 36a, 38a, 62a; 16b, 18b, 36b, 38b, 62b) with a first illumination source (16a; 16b) and at least one second illumination source (18a; 18b), and - a detector unit (80a; 80b) for determining at least one illumination property of the illumination light, wherein the detector unit is arranged within the illumination device in a beam path of the illumination light, wherein illumination light is supplied to only a subgroup of the group of illumination sources (16a, 18a, 36a, 38a, 62a; 16b, 18b, 36b, 38b, 62b) of at least one partial area (70b) of a detector area (72b) of the detector unit (80a; 80b).

Images