LIGHTING DEVICE WITH FIBER GUIDE DETECTION

Description

[0001] The present invention relates to a lighting device for an endoscope with integrated detection means for optical fiber recognition, as well as a method for operating the lighting device.

[0002] In modern endoscopy, the provision of a light source for illumination is essential when examining cavities that are generally difficult to access. In addition to providing a light source at the distal end of an endoscope for insertion into the cavity to be examined, it is already well known to provide an external light source or an illumination device comprising such a light source and to transmit light via a proximal end of the endoscope by means of a light guide having light-conducting fibers arranged therein to the distal end or endoscope tip, where the light exits to illuminate the cavity. In addition to a smaller endoscope design, this has the advantage of avoiding significant heat input into the cavity to be examined.

[0003] In addition to halogen bulbs or arc lamps, it is also already known to use light-emitting diodes (LEDs) as light sources in the lighting device. The light provided by the lighting device is typically coupled into the light guide connected to the endoscope or connectable to it via a provided light guide connector, for example, a plug-in coupling.

[0004] Previously known light sources or lighting devices incorporating them are typically matched to the respective light guide to be contacted. In particular, the emission surface of the light source is matched to the transmission surface of the light guide to be contacted. This enables a simple and, in particular, energy-efficient design of the lighting device. At the same time, however, it limits the possible applications. This is particularly true because different light guides and endoscopes are generally used depending on the intended use and anatomical conditions. For example, light guides with a diameter of 4.8 mm are preferred in laparoscopy, whereas significantly thinner light guides are used in otoscopy.

[0005] DE 10 2013 113 511 A1 discloses an endoscope with a fiber optic bundle for transmitting light from a proximal end to a distal end, wherein the proximal end comprises a continuous fiber optic bundle and the distal end comprises several arbitrarily distributed sub-bundles or individual fibers. The light is coupled in by means of an array-like LED light source with individual light sources assigned to the proximal end. The arbitrary distribution of the sub-bundles and the resulting distribution of the activated individual light sources aim to optimize the heat distribution in the light source. The individual light sources are controlled by a control unit using an assignment function that determines the assignment between individual sub-bundles and the proximal end surfaces of the fibers assigned to the respective individual light sources.The assignment function is determined using a separate test device during assembly of the endoscope, whereby the test device has external photodiodes for detecting a respective light output at the distal end of the sub-beams of the endoscope.

[0006] US 2011 / 0257483 A1 discloses a device comprising an LED matrix light source, a focusing unit associated with the LED matrix light source, and a light guide of an endoscope that can be arranged relative to an emission surface of the focusing unit. A control unit associated with the LED light source is configured to read a memory in a respective endoscope and, based on this, to control the light source.

[0007] US 2005 / 0140270 A1 discloses a lighting unit comprising an LED matrix field with a plurality of LED light sources and a light guide associated therewith, wherein the light guide is stabilized by a provided support structure between its first and second ends, and wherein the device comprises a heat sink which is thermally coupled to a conductor layer of the LED light sources.

[0008] Based on the known prior art, the present invention is based on the object of providing a lighting device and a method for operating a lighting device for an endoscope that addresses the above-mentioned disadvantages of the prior art. In particular, an improved lighting device and a method for operating a lighting device are to be provided that enables expanded applicability while simultaneously offering an energy-efficient and simple design.

[0009] This object is achieved by the device and method according to the independent claims. The dependent claims describe advantageous developments of the present invention. The invention also addresses further problems, as will become apparent from the following description.

[0010] In a first aspect, the invention relates to an illumination device for an endoscope, comprising illumination means for coupling light into a light guide connectable to the device, and comprising an LED matrix field comprising a plurality of LED pixels forming an emission surface, a light guide connection associated with the illumination means for positioning a light-conducting transmission surface arranged at the end of the light guide substantially orthogonal to a main emission direction of the emission surface of the LED matrix field, wherein the device comprises detection means designed to detect LED pixels of the emission surface aligned in the main emission direction towards non-light-conducting regions of the light guide, and that the device comprises a control unit designed to selectively control the LED pixels of the LED matrix field for coupling light into the light guide, such thatthat the LED pixels aligned in the main radiation direction towards the non-conductive areas of the light guide are at least partially controlled with lower power or deactivated.

[0011] The provided device enables the detection of non-light-conducting regions of a light guide arranged on the lighting device and thus the detection of different light guides with regard to their transmission surface or with regard to the non-light-conducting regions surrounding the transmission surface. When light is coupled into the light guide, a selective, i.e. individual, control of the individual LED pixels for light emission can thus take place, wherein the LED pixels aligned with non-light-conducting regions of the light guide are at least partially controlled with lower power or deactivated. This reduces or avoids the light input into non-light-conducting regions and thus undesirable thermal stress on the light guide and in particular on a generally metallic connector of the light guide.Furthermore, energy-efficient operation of the lighting device is enabled, as ideal utilization of the light source for each connected light guide is achieved, and not only the provision of an insufficiently small light-emitting emission surface for the connected light guide, but also, in particular, the provision of an excessively large light-emitting emission surface is avoided. Cooling for the light guide or light guide connector, which might otherwise be required, can also be avoided, thus achieving a simple and space-saving design of the lighting device in addition to the aforementioned advantages.

[0012] The term "LED matrix field" is understood below to mean an LED matrix array comprising a plurality of individually controllable LED pixels, arranged thereon, in particular in a grid-like manner. These are advantageously formed by individual, white-light-emitting LED chips. The LED matrix field preferably has between 500 and 4500, more preferably between 1000 and 4500 LED pixels. The individual LED pixels form a contiguous emission surface of the LED matrix field. The individual LED pixels are preferably designed to be individually controllable, at least in part, with regard to their light intensity or light emission. This can be achieved using conventional control methods, such as pulse-width modulation.

[0013] In the following, the "main emission direction" of the emission surface is understood to mean a direction orthogonal to the emission surface formed by the LED pixels, and in which light is emitted by the LED pixels.

[0014] In the following, "non-light-conducting regions" of the light guide are understood to mean parts of the light guide that are light-conducting and essentially non-light-conducting, particularly compared to a light-conducting transmission surface. These include, in particular, a light guide connector arranged at the end of the light guide or a light guide sleeve that surrounds the light-conducting and continuous transmission surface. The non-light-conducting regions are preferably reflective regions of the light guide, particularly those that are reflective opposite a main emission direction of the emission surface. The transmission surface of the light guide is preferably formed from a plurality of light-conducting fiber ends, which are arranged essentially orthogonally to the main emission direction of the emission surface for light coupling.

[0015] "Aligned toward a non-light-conducting region" is understood in particular to mean that the emission radiation of the respective LED pixel impinges on at least a portion of a non-light-conducting region in the main emission direction. This preferably means that, in a plan view of the emission surface, along the main emission direction, at least a portion, preferably at least 30%, more preferably at least 50%, of the respective LED pixel is concealed or covered by a non-light-conducting region of the light guide.

[0016] In a preferred embodiment, the control unit is designed to deactivate all LED pixels aligned in the main emission direction toward a non-light-conducting region of the light guide when coupling light into the light guide. This prevents unwanted heat input into non-light-conducting regions of the light guide and further optimizes the efficiency of light coupling.

[0017] In a preferred embodiment, the control unit is designed to detect a non-light-conducting outer contour of the light guide surrounding the transmission surface based on information provided by the detection means. The information provided can in particular comprise a spatial arrangement of the LED pixels aligned with the non-light-conducting regions in the emission surface. The control unit is preferably designed to selectively or individually control the LED pixels depending on the detected outer contour, such that LED pixels aligned with the outer contour and / or with a region radially outside the outer contour in the main emission direction are at least partially, more preferably completely, controlled with lower power or deactivated during light coupling.

[0018] This allows light emission through the LED matrix field towards the outer contour of the light guide and / or towards an area radially outside the outer contour of the light guide to be reduced or avoided, thereby preventing undesired heat input into the light guide and enabling more efficient operation of the device during light coupling into the light guide.

[0019] In a further preferred embodiment, the controller is alternatively or additionally designed to detect a continuous transmission surface of the optical fiber connected to the optical fiber connection based on the information provided by the detection means, in particular with regard to a spatial arrangement of the LED pixels aligned with the non-light-conducting regions in the emission surface. The control unit is preferably designed to selectively or individually control the LED pixels depending on the detected continuous transmission surface, such that only LED pixels aligned with the transmission surface in the main emission direction are controlled to emit light when the light is coupled into the optical fiber. The remaining LED pixels are then controlled at least with lower power and are preferably deactivated.

[0020] In a further preferred embodiment, the controller can alternatively or additionally be configured to detect at least two and preferably a plurality of different outer contours of a light guide based on the information provided by the detection means, in particular with regard to a spatial arrangement of the LED pixels aligned with the non-light-conducting regions in the emission surface. In this case, the control unit can be configured to selectively or individually control the LED pixels depending on the respectively detected outer contour according to a spatial arrangement of the LED pixels for light emission when light is coupled into the light guide, which is stored in the device.In this way, for example, a transmission surface of the light guide encoded by the respective outer contour of a light guide can be decoded by the control unit and the emission surface or the LED pixels of the emission surface can be controlled in a manner tailored to the respective transmission surface.

[0021] In a preferred embodiment, the lighting device has at least a first calibration mode for detecting the LED pixels of the emission surface aligned with non-light-conducting regions of the light guide, and a second operating mode for coupling light into the light guide. The control unit can be configured for sequential and / or alternating activation of the first and second operating modes.

[0022] The control unit can be designed such that, after activation of the device, for example by means of a provided control element, the calibration mode is first activated, in which the optical fiber connected to the device is detected by the detection means. In particular, the LED pixels that are aligned with non-light-conducting regions of the connected optical fiber are detected. Subsequently, the operating mode is activated, in which the actual light is coupled into the optical fiber by means of the illumination means and based on the individual control of the LED pixels by the control unit. Calibration preferably takes place within less than one second, more preferably less than 10 milliseconds.

[0023] Alternating activation of the first and second operating modes may, in particular, include activation of the calibration mode at preferably regular intervals, for example, every 30 seconds. This allows for continuous checking and / or correction of the fiber optic detection, for example, if the positioning of the fiber optic cable at or in the fiber optic connector changes, particularly due to external influences.

[0024] The detection means are preferably designed to detect reflected radiation, in particular, occurring counter to the main emission direction of the emission surface, in particular by non-light-conducting regions of the optical fiber. The detection means can thus detect reflected radiation that is reflected by the non-light-conducting regions of the optical fiber, in particular in a direction substantially counter to the main emission direction. The reflected radiation is, in particular, light radiation that is emitted by at least some of the LED pixels of the LED matrix array and reflected back by the non-light-conducting regions of the optical fiber.

[0025] In a preferred embodiment, the detection means are formed by at least some of the LED pixels of the LED matrix array, which are designed to be controllable as sensor elements by the control unit at least in a first calibration mode of the device. The corresponding LED sensor elements can be pure photodiodes, which are designed to detect light irradiation onto the respective LED and thus for the control unit to acquire sensor information. In a particularly preferred embodiment, however, the respective LED pixels that can be controlled as sensor elements are designed such that they can be controlled to emit light in a second operating mode.

[0026] To control the LED pixels emitting light in operating mode as sensor elements in calibration mode, the control unit is preferably designed such that the respective LED pixels are not supplied with current and / or voltage in calibration mode and are therefore not stimulated to emit light. In addition, the control unit taps a voltage and / or current signal, based on which the control unit can infer a respective reflected light incidence on the respective LED pixel. In this case, the invention utilizes the property of the respective LED chips or LED pixels that, when light falls on an LED that is switched off or not supplied with current or voltage, a light incidence-dependent current and / or voltage signal can be detected at the LED.

[0027] The control unit can comprise at least one microcontroller and associated memory means. The control unit can also be configured to execute a predefined analysis algorithm, which is implemented by individually controlling the LED pixels as a sensor element and / or as a light-emitting element.

[0028] The control unit is preferably designed to evaluate and, in particular, compare the signals of all LED pixels controlled as LED sensor elements. By appropriately evaluating the acquired sensor information or current and / or voltage signals, any light incident laterally on the respective LED pixel from neighboring LED pixels excited to emit light can be filtered out during the calculation or evaluation. In other words, by comparing the acquired sensor signals, the control unit can distinguish between LED pixels serving as sensor elements which are only partially (co-)irradiated by neighboring LED pixels in the emission area and excited to emit, and which are exposed to additional reflected radiation, in particular due to reflection occurring essentially opposite to the main emission direction at non-light-conducting regions of the light guide.The control unit can then identify the latter as LED pixels of the emitting surface aligned in the main emission direction toward non-light-conducting areas. These can then serve as reference points on the emitting surface or in the LED matrix field for individually controlling the emitting surface during light coupling into the light guide.

[0029] The control unit is preferably configured to control at least a first portion of the LED pixels of the LED matrix array to emit light in the first calibration mode and to control at least a second portion of the LED pixels of the LED matrix array as sensor elements for detecting reflected light incident on the respective LED pixel. The first portion of the LED pixels serving as an emission element can comprise a smaller or substantially equal number of LED pixels than the second portion serving as a sensor element.

[0030] The control unit can be configured to alternately control the first and second parts of the LED pixels as a sensor element and as a light-emitting element. This can further improve the detection accuracy of LED pixels aligned to non-light-conducting areas in the emitting area.

[0031] In a preferred embodiment, the control unit is designed as a sensor element for controlling a plurality of LED pixels distributed substantially uniformly and / or according to a predefined calibration pattern on the emission surface. The LED pixels controlled as sensor elements are preferably arranged uniformly distributed between the LED pixels controlled for light emission. This enables, in particular, optimized detection of the LED pixels aligned with non-light-conducting regions of the light guide. In a further preferred embodiment, the control unit is designed in the first calibration mode for sequentially controlling the LED pixels controlled for light emission in a manner that gradually expands radially from a center of the emission surface outwards, in particular substantially concentrically or star-shaped.

[0032] The control unit can be designed as a sensor element for controlling at least every fourth, preferably at least every third, LED pixel of the emitting area in a row and / or column direction of the emitting area of ​​the LED matrix array. In a further preferred embodiment, at least one, more preferably at least two, LED pixels controlled as a sensor element are arranged between two LED pixels adjacent in a row and / or column direction and serving as emitting elements.

[0033] In an alternative embodiment, the detection means can comprise an optical system arranged between the emission surface and the transmission surface of the optical fiber, in particular a beam splitter or a semi-transparent mirror, and an associated sensor unit for detecting radiation reflected back by non-conductive regions of the optical fiber. The associated sensor unit can comprise a CCD camera or a photodiode array, which enables feedback to the control unit regarding back reflections from non-light-conductive regions of the optical fiber.

[0034] The optical fiber connector is preferably designed for the centered positioning of at least two optical fibers with different transmission surfaces. The optical fiber connector preferably has a particularly circular receptacle into which a plug arranged at the end of the optical fiber can be inserted. The plug preferably comprises a sleeve-like configuration that surrounds the transmission surface arranged at the end for coupling light into the optical fiber. The plug preferably has a flat surface arranged parallel to the transmission surface. The plug is preferably made of metal.

[0035] The device preferably does not have any cooling means for cooling the optical fiber and in particular the optical fiber connector.

[0036] In a further aspect, the invention relates to the use of the lighting device as described above for coupling light into at least two light guides with transmission surfaces that differ from one another in terms of size and / or shape. The respective transmission surface preferably has a diameter between 1.5 and 14 mm, more preferably between 2 and 10 mm. The respective transmission surface is surrounded by a sleeve-like plug.

[0037] In a further aspect, the invention relates to a method for coupling light into a light guide for an endoscope, comprising the steps: Providing a lighting device with lighting means for coupling light into a light guide that can be connected to the device and having an LED matrix field comprising a plurality of LED pixels forming an emission surface, positioning an end-side light-conducting transmission surface of a light guide substantially orthogonal to a main emission direction of the emission surface of the LED matrix field, wherein the method comprises the further steps of: detecting LED pixels of the emission surface that are aligned in the main emission direction towards non-light-conducting regions of the light guide, and coupling light into the light guide while selectively controlling the LED pixels of the emission surface for light emission, wherein the LED pixels aligned towards non-light-conducting regions are at least partially controlled with lower power or are deactivated.

[0038] To avoid repetition, reference is made to the previously described lighting device according to the invention. The features disclosed for the device are intended to be disclosed and claimable for the method, and vice versa.

[0039] In a preferred embodiment, the detection comprises controlling a first part of the LED pixels of the emission surface for light emission and controlling a second part of the LED pixels of the emission surface as sensor elements for detecting reflected light incidence on the respective LED pixel.

[0040] The detection preferably comprises a varying control of the respective LED pixels as a light emission element or as a sensor element. The varying control of the respective LED pixels can take place according to a predefined temporal sequence and / or a spatial arrangement of the respective LED pixels on the emission surface. The control can comprise a substantially checkerboard-like or checkerboard-shaped control of a first part of the LED pixels for light emission and of a second part of the LED pixels as a sensor element. Alternatively or additionally, the control can comprise a control of a first part of the LED pixels for light emission that expands radially outwards from a center of the emission surface, in particular substantially concentrically or star-shaped. The respective control can be carried out only once, twice, or multiple times according to a predefined sequence.

[0041] The detection can also include identifying an outer contour of the light guide by evaluating a sensor reading on the LED pixels controlled as sensor elements. The detection can be based directly on the detected signal readings on the LED pixels and / or based on interpolation performed by the control unit and based on the signal readings. Upon light coupling, the LED pixels are then selectively controlled such that LED pixels aligned in the main radiation direction toward the outer contour and / or toward an area radially outside the outer contour are at least partially, preferably completely, controlled with lower power or deactivated.

[0042] Details, advantageous effects and details of the present invention are explained below with reference to the purely schematic, merely exemplary drawings.

[0043] Showing: Fig.1 a lighting device according to a preferred embodiment of the invention in front view; Fig. 2a a schematic detailed view of a light guide for connection to the lighting device; Fig. 2b a detailed view of the device without the connected light guide; Fig. 3 a schematic plan view of an LED matrix field of the lighting means of the device; Fig. 4 a schematic side view of a coupling of a light guide to the illumination means at the light guide connection of the device; Fig. 5a,b a preferred embodiment of a calibration mode of the device for detecting the optical fiber with a substantially checkerboard arrangement of the sensor elements; Fig. 6a-d a further preferred embodiment of a calibration mode of the device for detecting the optical fiber with an outwardly radially expanding arrangement of the light emitting elements; Fig. 7a,b a schematic plan view of the lighting means with different control of light guides in working mode for coupling light into the light guide; Fig. 8a,b a schematic plan view of the lighting means with different control of light guides with different outer contours; Fig. 9 a further preferred embodiment of the device according to the invention, comprising optics arranged between the emission surface and the transmission surface.

[0044] Fig. 1 shows a lighting device 10 for an endoscope 20, comprising lighting means 1 for coupling light into a light guide 2 that can be connected to the device via a light guide connection 5. The device can have a user interface 10a, which can in particular comprise an on / off switch and / or a control for the light intensity. The device 10 further comprises a power supply (not shown) and lighting means associated at least with the power supply and with the light guide connection 5 (cf. Fig. 2b ) connected control unit 8. The light guide 2 can be firmly connected to the endoscope 20 or, in particular, can be designed so that it can be screwed onto or onto the endoscope via a twist lock.

[0045] Fig. 2a schematically shows an end-side connection or plug region 30 of the light guide 2, designed for connection to the lighting device 10. This comprises a circular transmission surface 2a, which is formed by a plurality of fiber ends 2c arranged therein. The transmission surface 2a is surrounded or enclosed by a non-light-conducting, in this case sleeve-like outer contour 2b, which is formed by a light guide sleeve 2d surrounding the optical fibers of the light guide. In the connection or plug region, the light guide sleeve 2d is preferably flat. The plug region 30 and furthermore preferably the flat outer contour 2b are preferably made of, in particular, polished metal.

[0046] Fig. 2b shows a front view of the device 10 without a connected light guide 2. The lighting means 1 comprise an LED matrix field 3 arranged centrally with respect to the light guide connection 5. Fig. 3 shows a schematic detailed view of the LED matrix field 3, which has a plurality of individual LED pixels 4a,...,4n, arranged in particular in a grid-like manner or in the row and column direction Z, S, and which form a coherent emission surface 4.

[0047] Fig. 4 shows a schematic side view of a coupling of a light guide 2 to the illumination means 1 at the light guide connection 5 of the device 10. In the connected arrangement, the light guide 2 is preferably arranged with its transmission surface 2a substantially parallel to the emission surface 4 of the LED matrix field 3. A main emission direction L of the emission surface 4 is thus arranged substantially orthogonal to the transmission surface 2a. An end-side outer contour surface 2e of the light guide sleeve 2d is also preferably arranged substantially parallel to the emission surface 4.

[0048] The figure shows a first calibration mode of the device for detecting the LED pixels of the emission surface 4 aligned with non-light-conducting regions 7a,...,7n of the light guide 2. In the calibration mode, the control unit 8 is designed to control at least a first part of the LED pixels 9a,...,9n of the LED matrix field 3 for light emission E and to control at least a second part of the LED pixels 9a',...,9n' of the LED matrix field 3 as sensor elements for detecting reflected light incidence R on the respective LED pixel.

[0049] For simplification, the schematic drawing only shows one light emission E of the respective LED pixels in the main emission direction L. As in Figur 4 As shown, a reflection R occurs at the non-light-conducting regions 7a,b of the light guide 2. Radiation R reflected back thereby, which is oriented substantially opposite to the main emission direction L, can then be detected by the LED pixels 9a',...,9n` each aligned with the non-light-conducting regions 7a,b and designed as sensor elements and / or adjacent to the LED pixels 9a,...,9n aligned with the non-light-conducting regions 7a,b and serving as emission elements. In this case, in particular, a current and / or voltage signal occurring at the sensor elements 9a',...,9n` due to the reflected light incidence is tapped by the control unit. The occurring reflection R can, in addition to a direct reflection at the respective non-light-conducting regions 7a,7b, at least partially also comprise a diffuse reflection or diffuse reflection radiation R'.Diffuse reflection radiation R' is understood to mean scattered reflection, in particular due to possible unevenness on the respective surface of the non-light-conducting areas 7a, 7b,..., 7n of the light guide 2.

[0050] The control unit 8 is preferably designed such that it controls the respective LED pixels 4a,...4n in a varying and / or alternating manner as emission elements 9a,...,9n and as sensor elements 9a',...9n'. Such a design is exemplified in Fig. 5a und 5b shown. The control unit 8 is designed to control the first LED pixels 9a,...,9n controlled as emission elements and the second LED pixels 9a',...,9n' controlled as sensor elements according to a predefined calibration pattern, in this case, for example, according to a checkerboard arrangement. For example, every second LED 4a,...,4n of the emission surface 4 can be calibrated in the row direction Z and / or column direction S (cf. Fig. 3 ) can be controlled as emission element 9a,...,9n to provide light emission for detecting the non-light-conducting areas of the connected light guide 2. The remaining LED pixels can be controlled as sensor elements 9a',...9n' to detect reflections on non-light-conducting areas 7a,...,7n of the light guide 2, in particular on the outer contour surface 2e of the light guide sleeve 2d surrounding the transmission surface 2a. The non-light-conducting areas 7a,...,7n are in Fig. 5a, 5b shown merely by way of example and schematically. The non-light-conducting regions 7a,...,7n preferably form the outer contour surface 2e of the light guide 2.

[0051] After emission and detection in the Fig. 5a In the arrangement shown, a varying control of the individual LED pixels 4a,...4n can be carried out, as in Fig. 5b Here, the checkerboard-shaped control of the individual LED pixels is parallel or diagonally offset by an offset V compared to the formation in Fig. 5a offset or shifted. This means that LED pixels previously controlled as sensor elements 9a',...9n' are now controlled as emission elements 9a,...9n, and vice versa. In this case, the current and / or voltage signals occurring at the sensor elements 9a',...9n' due to the reflected light incidence R are again detected by the control unit 8.

[0052] The control unit 8 can be designed to compare the signals of all LED pixels 9a',... 9n' controlled as LED sensor elements. The control unit 8 can distinguish, preferably by comparing the tapped sensor signals, between LED pixels serving as sensor elements which are only (co-)irradiated by emission elements 9a,...,9n arranged adjacently in the emission surface 4 and which are exposed to additional reflection radiation R, in particular due to reflection R occurring essentially opposite to the main emission direction L at non-light-conducting regions 7a,...7n of the light guide 2. The control unit 8 can then identify the latter as LED pixels of the emission surface 4 which are aligned in the main emission direction L towards non-light-conducting regions. These can then be used as reference points on the emission surface 4 orin the LED matrix field 3 for the individual control of the emission surface 4 when coupling the light into the light guide 2.

[0053] Fig. 6a-6d show an alternative embodiment in which the LED pixels 4a,...,4n are controlled in calibration mode such that an arrangement of the LED pixels 9a,...,9n controlled for emission gradually expands outward and preferably radially from a center of the emission surface. The remaining LED pixels can be controlled as sensor elements 9a',...,9n'.

[0054] Fig. 7a,7b A schematic top view of the lighting means 1 during the different control of light guides 2, 2' with different transmission areas 2a, 2a' in the working mode. The working mode of the device 10 corresponds to the operation for coupling light into the light guide 2, 2' connected to the device. Due to the previously performed calibration, the control unit 8 detects LED pixels of the emission surface 4 that are aligned with non-light-conducting regions of the light guide 2. These are preferably controlled with less power or, more preferably, deactivated in the working mode. The remaining LED pixels 9a,..., 9n are controlled for light emission with a predefined power that can be optionally adjusted by the user.

[0055] The control unit 8 further preferably detects an outer contour 2b of the light guide 2 connected to the device in the calibration mode and, in the working mode, controls the LED pixels aligned in the main emission direction L towards the outer contour 2b and / or towards an area radially outside the outer contour 2b at least partially with lower power during light coupling or deactivates them.

[0056] Fig. 8a und 8b show an example and schematically a detection of the respective outer contour 2b of a connected optical fiber. As in Fig. 8a As shown, the control unit 8 can be configured to detect a displacement or offset of the optical fiber 2 relative to the emission surface 4, for example, due to external influences. This can be achieved by alternately activating the previously described calibration mode and the operating mode. In particular, the calibration mode can be activated at regular intervals during the operating mode. The control of the emission surface 4 can be adjusted accordingly in the subsequent operating mode.

[0057] Fig. 8b shows, merely by way of example, the detection of a varying outer contour 2b' of a light guide 2, which, unlike the previously shown outer contour, has a polygonal contour. The controller can optionally be designed to detect at least two and preferably a plurality of different outer contours 2b, 2b` of a light guide 2 based on the information provided by the detection means, in particular with regard to a spatial arrangement of the LED pixels aligned with the non-light-conducting regions in the emission surface. In this case, the control unit can then be designed to individually control the LED pixels depending on the respectively detected outer contour in accordance with a spatial arrangement of the LED pixels for light emission when light is coupled into the light guide.

[0058] Fig. 9 shows an alternative embodiment of the device 10 according to the invention. Here, the detection means comprise an optic 6 arranged between the emission surface 4 and the transmission surface 2a of the light guide 2, in particular a beam splitter or semi-transparent mirror, as well as an associated sensor unit 11 for detecting radiation R reflected back by non-light-conducting regions 7a,...,7n of the light guide 2. The sensor unit 11 can comprise a CCD camera or a photodiode array.

[0059] In calibration mode, a portion of the emitted light, which is reflected back by the non-light-conducting regions of the light guide 2, is detected by the associated sensor unit 11 via the optics, for example the semi-transparent mirror. In particular, a relative position detection of the respective reflected radiation R can be performed. Based on this detection, the respective LED pixels 4a,...,4n can be controlled accordingly in the operating mode, as previously described for the other exemplary embodiments. In the operating mode, the optics 6 can also be removed from the emission region of the illumination means 1, for example by pivoting (direction A). Bezugszeichenliste

[0060] 1Illumination source 2Light guide 2aTransmission surface 2bOuter contour 2cLight-conducting fibers 2dLight guide sleeve 2eOuter contour surface 3Matrix field 4Emission surface 4a,..,4nLED pixel 5Light guide connector 6Optics 7a,...,7nNon-light-conducting parts of the light guide 8Control unit 9a,...,9nEmission element 9a',...,9n'Sensor element 10Device 10aUser interface 11Sensor unit 20Endoscope 30Connector area A Swivel direction EEmission radiation LMain radiation direction R,R'Reflection radiation SScolumn direction VOffset ZRow direction

Claims

1. An illumination device (10) for an endoscope (20), the device comprising illumination means (1) for coupling light into a light guide (2) connectable to the device, the illumination means comprising an LED matrix array (3) comprising a plurality of LED pixels (4a, ..., 4n) forming an emission area (4), and a light guide port (5) associated with the illumination means (1) for positioning a light-guiding transmission area (2a), which is disposed at an end of the light guide, essentially orthogonally to a main emission direction (L) of the emission area (4) of the LED matrix array (3), characterized in that the device comprises detection means which are configured to detect LED pixels of the emission area (4) that are directed at non-light-guiding portions (7a, ..., 7n) of the light guide (2) in the main emission direction (L), and that the device (10) has a control unit (8) configured to selectively operate the LED pixels (4a, ..., 4n) of the LED matrix array (3) for coupling light into the light guide (2) in such a manner that at least some of the LED pixels directed at the non-guiding portions (7a, ..., 7n) of the light guide (2) in the main emission direction (L) are operated at lower power or deactivated.

2. The illumination device according to claim 1, characterized in that the control unit (8) is configured to detect a non-light-guiding outer contour (2b) of the light guide (2) surrounding the transmission area (2a) based on information provided by the detection means, and that the control unit (8) is configured to selectively operate the LED pixels (4a, ..., 4n) as a function of the detected outer contour (2b) in such a manner that at least some of the LED pixels (4a, ..., 4n) directed at the outer contour (2b) and / or at an area radially outside of the outer contour (2b) in the main emission direction (L) are operated at lower power or deactivated when light is being coupled in.

3. The illumination device according to any one of claims 1 or 2, characterized in that the illumination device (10) comprises at least a first calibrating mode for detecting the LED pixels of the emission area (4) that are directed at non-light-guiding portions (7a, ..., 7n) of the light guide (2) and a second work operating mode for coupling light into the light guide (2), and that the control unit (8) is configured to sequentially and / or alternately activate the first and the second operating mode.

4. The illumination device according to any one of claims 1 to 3, characterized in that the detection means are configured to detect reflected radiation (R) occurring in particular in a direction opposite to the main emission direction (L) of the emission area (4), in particular radiation (R) reflected by non-light-guiding portions (7a, ..., 7n) of the light guide (2).

5. The illumination device according to any one of the preceding claims, characterized in that the detection means are formed by at least some of the LED pixels (4a, ..., 4n) of the LED matrix array (3) which are configured to be operated as sensor elements by the control unit (8) at least in a first calibrating mode of the device (10) and to be operated for light emission at least in a second work operating mode.

6. The illumination device according to claim 5, characterized in that the control unit (8) is configured to operate at least a first part of the LED pixels of the LED matrix array (3) for light emission in the first calibrating mode and to operate at least a second part of the LED pixels of the LED matrix array (3) as sensor elements for detecting reflected light incident on the respective LED pixel.

7. The illumination device according to claim 6, characterized in that the control unit (8) is configured to alternately operate the first and the second part of the LED pixels (4a, ..., 4n) as sensor elements and as light emission elements.

8. The illumination device according to any one of claims 5 to 7, characterized in that the control unit (8) is configured to operate a plurality of LED pixels (4a, ..., 4n) distributed on the emission area (4) essentially uniformly and / or according to a pre-defined calibrating pattern as sensor elements.

9. The illumination device according to any one of claims 5 to 8, characterized in that the control unit (8) is configured to operate at least every fourth, preferably every third LED pixel of the emission area (4) in a row direction (Z) and / or a column direction (S) of the emission area (4) of the LED matrix array (3) as a sensor element.

10. The illumination device according to any one of claims 5 to 9, characterized in that the control unit (8) in the first calibrating mode is configured to sequentially operate the LED pixels operated for light emission in a manner gradually widening radially outward from a center of the emission area, in particular essentially concentrically or in a star shape.

11. The illumination device according to any one of preceding claims 1 to 4, characterized in that the detection means comprise optics, in particular a beam splitter or a semi-transparent mirror, disposed between the emission area (4) and the transmission area (2a) of the light guide (2), and an associated sensor unit (11), in particular a CCD camera or a photodiode array, for detecting radiation (R) reflected back by non-guiding portions (7a, ..., 7n) of the light guide (2).

12. The illumination device according to any one of the preceding claims, characterized in that the LED matrix array (3) preferably comprises between 500 and 4500, more preferably between 1000 and 4500 LED pixels (4a, ..., 4n), which are preferably formed by white light emitting LED chips.

13. The illumination device according to any one of the preceding claims, characterized in that the light guide port (5) is configured to position, preferably center, at least two light guides (2, 2') having different transmission areas.

14. A method for coupling light into a light guide for an endoscope, the method comprising the following steps: - providing an illumination device (10) comprising illumination means (1) for coupling light into a light guide (2) connectable to the device, the illumination means comprising an LED matrix array (3) comprising a plurality of LED pixels (4a, ..., 4n) forming an emission area (4), - positioning a light-guiding transmission area (2a), which is disposed at an end of a light guide (2), essentially orthogonally to a main emission direction (L) of the emission area (4) of the LED matrix array (3), characterized in that the method further comprises the following steps: - detecting LED pixels of the emission area (4) that are directed at non-light-guiding portions (7a, ..., 7n) of the light guide (2) in the main emission direction, and - coupling light into the light guide (2), with the LED pixels of the emission area (4) being selectively operated for light emission, wherein at least some of the LED pixels directed at non-light-guiding portions (7a, ..., 7n) are operated at lower power or are deactivated.

15. The method according to claim 14, characterized in that the detection comprises operating a first part of the LED pixels of the emission area for light emission and operating a second part of the LED pixels of the emission area as sensor elements for detecting reflected light incident on the respective LED pixel.

16. The method according to claim 15, characterized in that the detection comprises operating the respective LED pixels in a varying manner as light emission elements (9a, ..., 9n) or as sensor elements (9a', ..., 9n'), preferably according to a predefined chronological order and / or a spatial arrangement of the respective LED pixels on the emission area.

17. The method according to claim 15 or 16, characterized in that the operation comprises operating a first part of the LED pixels for light emission and operating a second part of the LED pixels as sensor elements in an essentially chessboard-like manner.

18. The method according to any one of claims 15 to 17, characterized in that the operation comprises operating a first part of the LED pixels for light emission in a manner widening radially outward from a center of the emission area, in particular essentially concentrically or in a star shape.

19. The method according to any one of claims 15 to 18, characterized in that the detection comprises detecting an outer contour (2b) of the light guide (2) by evaluating sensor data acquired by the LED pixels operated as sensor elements, wherein during the coupling in of light the LED pixels are selectively operated in such a manner that at least some of the LED pixels directed in the main emission direction (L) at the outer contour (2b) and / or at an area radially outside of the outer contour (2b) are operated at lower power or deactivated.

20. A use of the illumination device according to any one of claims 1 to 13 for coupling light into at least two light guides (2, 2') having transmission areas (2a, 2a') differing in size and / or shape.