WO2010052174A1

WO2010052174A1 - Semi-transparent illumination apparatus

Info

Publication number: WO2010052174A1
Application number: PCT/EP2009/064385
Authority: WO
Inventors: Peter Westphal; Daniel Bublitz; Johannes Knoblich; Johannes Winterot
Original assignee: Carl Zeiss Ag
Priority date: 2008-11-04
Filing date: 2009-10-30
Publication date: 2010-05-14
Also published as: DE102008055714B4; DE102008055714A1

Abstract

A semi-transparent illumination apparatus which emits on one side comprises a luminous layer (120) and a screening layer (130) which is made of a non-transparent material and is arranged between a rear side of the illumination apparatus and the luminous layer (120). A multiplicity of transparent hole regions (140) at which the luminous layer (120) and the screening layer (130) are broken through and which extend between the rear side and a front side of the illumination apparatus. The screening layer (130) has edge regions (132) which are each formed around the hole regions (140) and project beyond the luminous layer (120).

Description

Semitransparent lighting device

The present invention relates to a planar semitransparent lighting device with single-sided radiation characteristic.

Numerous electrically powered radiation sources are known for illuminating objects, e.g. Incandescent lamps, arc lamps, lasers, LEDs (LED: "Light Emitting Diode") and OLEDs (OLED: "Organic Light Emitting Diode"). To obtain areal illumination, most of the radiation sources mentioned must be combined with a homogenizing or scattering optic (for example diffuser). Only the OLED has a priori the property to radiate areally and homogeneously from a very thin layer.

The usual structure of OLEDs is that a substrate with a transparent conductor layer, e.g. indium tin oxide (ITO). The transparent wiring layer is followed by a hole line layer, a luminescent layer containing small organic molecules or polymers, an electron conduction layer, and a low workfunction metal cathode layer. When an electric current flows through these layers, the luminescent layer, which is typically only about 200 nm thick, emits radiation. This radiation is usually in the visible spectral range, but may also have shares in the ultraviolet or infrared spectral range.

Further developments of OLEDs aim to replace the relatively expensive ITO layer with other transparent and simultaneously conductive materials. It has been found that, for example, gold nanowires are in principle suitable for this purpose.

Furthermore, it is also known that the luminous surface of an OLED can be structured. For this purpose, it is possible, for example, to use shadow masks when evaporating the OLED layers. For polymer OLEDs, printing processes can be used for structuring. A distinction can be made between two basic types of OLEDs. In one design, one electrode layer is transparent (eg, ITO) while the other is an untransparent metallic layer. In this design, the radiation generated by the OLED is emitted only on one side through the transparent electrode layer. Accordingly, this design is also impermeable to other light.

In the second design, both electrode layers are transparent, for example made of ITO. Here, the OLED radiates from both sides, and it is also permeable to other light. However, imaging through such an OLED is only possible to a limited extent because the two-sided radiation causes dazzling of the detector (for example camera or eye). At least a significant decrease in contrast is to be expected when the OLED radiates in the direction of the detector.

US 2006/0202104 A1 discloses a monolithic image sensor which can be provided with a semitransparent luminous layer emitting on one side. The unilaterally radiating semitransparent luminescent layer can be implemented on the basis of LEDs or OLEDs. The luminescent layer contains on one side a metallic contact layer. Holes formed in the luminescent layer allow the passage of light to an image-receiving layer. However, even in this known lighting device, light generated in the luminescent layer may be scattered through the holes in the direction of the image-capturing layer. This problem is exacerbated when the proportion of holes in the total area of the luminescent layer is increased to achieve improved transparency. There is a need, therefore, for single-sided radiating semitransparent lighting devices that allow for improved separation of the generated light and the transmitted light.

An object of the present invention is to provide a lighting device which has an improved suitability for image capture by the lighting device.

This object is achieved by a lighting device according to claim 1. The dependent claims define advantageous embodiments of the invention.

According to the present invention, a lighting device comprises a luminescent layer and one between the back of the lighting device and the Luminescent layer arranged shielding of an untransparent material. Furthermore, a plurality of transparent hole regions are provided which extend through the luminescent layer and the shielding layer between the rear side and a front side of the illumination device. The luminescent layer and the shielding layer are thus broken at the hole areas. The shielding layer has respective edge regions formed around the hole regions, the edge regions projecting beyond the luminescent layer. Preferably, the edge regions protrude beyond the luminescent layer by at least one micrometer. The hole areas can have any suitable shape in cross-section, for example round, oval, rectangular, triangular, polygonal or strip-like. The extension of the hole areas in the plane of the shielding layer is 500 μm or less in at least one direction. The hole areas may be arranged in the plane of the shielding layer in a periodic grid. Alternatively, an irregular or stochastic arrangement is possible. The latter may be advantageous in certain applications to reduce moiré effects. Furthermore, it is also not necessary that the hole areas each have the same shape and size. Using different shapes and sizes for the hole areas can also help reduce moiré effects.

In the lighting device according to the invention, light is emitted on one side in the direction of the front side of the lighting device. The shielding layer prevents radiation of light towards the back of the lighting device. In particular, the edge regions which project beyond the luminescent layer prevent light generated by the luminescent layer from being emitted or scattered in the direction of its rear side within the illumination device. This advantage is maintained even if the proportion of the hole areas on the total area of the luminescent layer is relatively high, e.g. 50% or more.

According to one embodiment, shielding walls of an untransparent material are formed around the hole areas. The shielding walls may extend substantially perpendicular to the shielding layer and the luminescent layer. The shielding walls are formed along a part of the hole portions between the shielding layer and the front side of the lighting device. The shielding walls may be connected to the shielding layer. The shielding walls preferably extend between the luminescent layer and the hole regions. In particular, the shielding walls can extend beyond the luminescent layer in the direction of the front side of the lighting device. An amount of the Screen walls along the axis of the hole areas is preferably larger, the greater the width of the enclosed between two adjacent hole areas luminescent layer. The height of the shielding walls can be selected, for example, depending on the width of the enclosed luminescent layer in a range between 10 .mu.m and 500 .mu.m. The shielding layer and / or the shielding walls can be designed to be reflective. However, it is also possible for the side of the shielding walls facing the luminescent layer or the side of the shielding walls facing the hole areas to be designed to be absorbent.

By means of the shielding walls, beam traps are formed around the luminescent layer, which enable an effective suppression of the scattering or radiation of light generated in the luminescent layer in the direction of the rear side of the lighting device.

According to a further preferred embodiment, the lighting device comprises at least one further luminescent layer, which is arranged between the luminescent layer and the front side of the lighting device. The further luminescent layer is made of a transparent material. By way of example, the further luminescent layer may be an OLED luminescent layer. In this embodiment, the luminous regions also extend through the further luminous layer or through the further luminous layers, and shielding walls are provided, which extend between the further luminous layer and the hole regions, so that beam traps are also formed around the further luminous layer or around the further luminous layers are.

In addition, the lighting device may comprise one or more antireflection layers. For example, an antireflection layer may be arranged on the front side of the illumination device. In addition, an internal anti-reflection layer can be formed between each luminescent layer and the front side of the lighting device. In addition, an antireflection layer can also be provided on the back of the lighting device. The antireflection layers may include, for example, the dielectric multilayers or moth-eye structures. The antireflection layers preferably have a reflectivity of less than one percent in the visible spectral range.

In a further preferred embodiment, a transparent protective layer is arranged on the front side of the lighting device. The transparent Protective layer may be, for example, a thin cover glass plate. The transparent protective layer protects the luminescent layer from harmful external influences, eg mechanical damage or chemical aging. In addition, the emission behavior of the illumination device can be purposefully improved by the protective layer. For example, the protective layer may be configured such that light reflected inwardly on the outside of the protective layer from the luminescent layer remains trapped due to total reflection in the illumination device.

Moreover, in a preferred embodiment, a plurality of microlenses may be disposed on the front of the illumination device. The microlenses can prevent light from the luminescent layer, which is reflected inwardly at the front side of the lighting device, from being directed in the direction of the hole regions. For this purpose, the microlenses are preferably located between the hole areas, i. in front of the regions of the luminous layer formed between the luminous areas. Furthermore, a targeted beam deflection, in particular focusing, of the light emitted from the illumination device can be achieved by the microlenses. In this way, for example, the irradiance in an object plane can be partially increased.

The illumination device can be produced by a layer structure on a transparent back substrate. However, it may also be provided separate intermediate substrates, which are attached to a carrier substrate. For example, such intermediate substrates may be configured as a perforated plate which is perforated at the positions of the perforated regions. The luminescent layer and / or a further luminescent layer can then be applied to the surface of the perforated plate. The inner walls of the hole areas formed in the perforated plate may be coated to form the shielding walls.

The substrates used in the lighting device may be planar or have curved surfaces. The lighting device can thus be provided with a curvature. The curvature may be, for example, spherical or cylindrical. For example, the layers of the illumination device can be applied to a curved surface of a lens. In this case, the lens would represent a carrier substrate for the lighting device. Furthermore, the lighting device can also be constructed on the basis of deformable substrates. The luminescent layer and / or the further luminescent layers may each be formed as a coherent luminescent layer. Alternatively, a plurality of luminous regions can be formed, which can be controlled separately. In this case, a targeted activation of the separate lighting areas is possible in order to achieve lighting with controllable area-like patterns.

The lighting device according to the invention can be advantageously used for a large number of applications. For example, the illumination device according to the invention may be provided in an optical device, for example in an endoscope, a microscope, a magnifying glass, a pair of glasses, a lens, a camera, e.g. a photographic camera, a movie camera or a video camera, a display device, a copier or a scanner. In this case, the illumination device may be applied to an optical element of the optical device. The optical element may be a transmissive imaging element, e.g. a lens, a reflective imaging element, e.g. a semitransparent mirror, or a beam splitter element. In addition, the lighting device may be part of a watch glass, a display case, a cabinet, an aquarium or a terrarium. Furthermore, the illumination device can be part of a picture frame. The lighting device can also be part of a refrigerator or freezer or a window pane to a neighboring room. The illumination device can serve to illuminate a reflective display device or be used for incident illumination for a matrix-like arrangement of miniature lenses.

According to embodiments of the invention, the lighting device may thus be mounted on or in front of a spectacle lens, a lens of a magnifying glass or a watch glass. Furthermore, the illumination device can be part of a microscope, for example, mounted on or in front of an optical element of the microscope. The lighting device may also be part of an ophthalmological device, for example mounted on or in front of an optical element of the ophthalmological device. The lighting device can also be part of a camera, for example a photo camera, a film camera or a video camera. In particular, the illumination device can be mounted on or in front of an optical element of the camera. The lighting device may also be part of a display device, for example, mounted on or in front of a scale or data display. The scale or data display can be static or variable in content. Furthermore, lighting device with respect to the scale or data display displaceable or be rotatable, for example in the manner of a pointer instrument. The lighting device can also be mounted on or in front of an electronically controllable display device, for example a segment or matrix display device. Furthermore, the lighting device may also be part of a reading device for electronic books or e-book readers. For example, the lighting device may be mounted on or in front of a display device of the reader. In general, the lighting device can advantageously be used in conjunction with all reflective display devices, eg with static or variable content. The lighting device may also be part of a head-mounted display, for example, be mounted on or in front of a transparent element of the head-mounted display. The lighting device may also be mounted on or in front of magazines, newspapers, books, pictures, posters, posters, signs or paintings. Furthermore, the lighting device can be used to illuminate the interior of a showcase, a cabinet, a refrigerator, a stove, an aquarium, a greenhouse or the like. In addition, the lighting device can be used to illuminate the interior of a container or packaging, for example as part of a viewing window.

When the illumination device is applied to a specular optical element, better beam shaping can be achieved for different illumination arrangements. Furthermore, the use of the lighting device is made possible in hybrid lenses. When using the illumination device as part of a beam splitter element, applications are possible which combine incident-light fluorescence microscopy methods with a dimmable incident-light / bright-field microscopy method, i. in a multimodal microscopy method.

The invention will be explained in more detail below with reference to the accompanying drawings with reference to embodiments.

1 schematically illustrates a lighting device according to an embodiment of the invention.

FIG. 2 shows a schematic plan view of the illumination device of FIG. 1. FIG.

3 schematically illustrates a lighting device according to a further exemplary embodiment of the invention. 4 schematically illustrates a lighting device according to another embodiment of the invention.

5 schematically illustrates a lighting device according to a further exemplary embodiment of the invention.

FIG. 6 schematically shows a plan view of intermediate substrates used in the lighting apparatus of FIG. 5.

Fig. 7 schematically illustrates a lighting device according to another embodiment of the invention.

8 schematically illustrates an optical device in the form of a pair of glasses with a lighting device according to the invention.

9 schematically illustrates an optical device in the form of a lens with a lighting device according to the invention.

10 schematically illustrates an optical device in the form of a mapping optical system with a lighting device according to the invention.

Fig. 1 1 schematically illustrates an optical device in the form of a microscope with a lighting device according to the invention.

In the following description of embodiments, reference is made to the accompanying drawings in which like or similar elements are designated by the same reference numerals throughout. A repeated description of these elements will be omitted. It is understood that the structures illustrated in the drawings are not to scale. In particular, layer thicknesses can be exaggerated for reasons of clarity.

Fig. 1 schematically illustrates a lighting device. The lighting device comprises a transparent back substrate 110. The transparent back substrate 110 may consist, for example, of glass, crystal, ceramic or plastic. Applied to the back substrate 110 is a luminescent layer 120, which is designed as an OLED luminescent layer. However, other forms are also conditions of the luminescent layer 120 possible, for example, as an inorganic LED luminescent layer.

The luminescent layer 120 is structured periodically in that a periodic lattice of hole regions 140 is formed in the luminescent layer 120. The illustration of FIG. 1 shows a cross section through the hole regions 140 and webs of the luminescent layer 120 formed between the hole regions 140.

The luminescent layer 120 is at least over some periods of structuring, e.g. five or more periods, coherently formed. In this way, only one electrical contact via an anode layer and a cathode layer (not shown) is required for the contiguous regions of the luminescent layer 120. It goes without saying that the entire luminescent layer 120 can also be designed as a single coherent luminous area. When subdivided into a plurality of contiguous luminous regions of the luminous layer 120, a separate electrical actuation of the individual luminous regions can be provided in order to be able to control, for example, the generation of different planar illumination patterns.

The light-emitting layer 120 is provided on one side with a transparent electrode layer, so that light generated in this side in the light-emitting layer 120 can be emitted in the direction of a front side of the lighting device. The transparent electrode layer may be made of ITO or other transparent and electrically conductive material, e.g. Gold nanowires. On the other side of the luminescent layer 120, a transparent electrode layer may likewise be formed.

On the other side of the luminescent layer 120, that is to say the side facing a rear side of the illumination device, a shielding layer 130 is formed from an opaque material. In the example illustrated in FIG. 1, the luminescent layer 120 is formed directly on the shielding layer 130. The shielding layer 130 prevents light generated by the luminescent layer 120 from being emitted toward the back of the lighting device. However, it is understood that the shielding layer 130 could also be arranged between the luminescent layer 120 and the front side of the lighting device, so that light generated in the luminescent layer 120 can only be emitted towards the rear side of the lighting device. In the following, however, only the Case of delivery of the light generated in the luminescent layer 120 toward the front of the lighting device are considered.

The shielding layer may be a metallic electrode which serves to drive the luminescent layer 120. In order to avoid reflections on the metallic electrode, an absorbing layer and / or an antireflection coating can be introduced between the luminescent layer 120 and the back substrate 110 in this case. The absorbing layer may contain, for example, nanoparticles.

Between the luminescent layer 120 and the front side of the lighting device, a transparent protective layer 150 is furthermore applied. The protective layer 150 may be, for example, a thin glass plate, a vapor-deposited oxide layer or a thin polymer layer. The protective layer 150 protects the luminescent layer 120 against aging processes such as oxidation and against mechanical damage. In particular, in the case of a protective layer 150 formed as a glass plate or polymer layer, air, a protective gas or a polymer-based embedding medium, e.g. transparent adhesive.

In order to avoid that light generated in the luminescent layer is scattered by reflection on or in the protective layer 150 in the direction of the back substrate 110, the protective layer 150 is preferably provided with an antireflection layer 155. For the antireflection layer 155, a reflectivity of well below one percent in the visible spectral range is preferred.

Furthermore, also on the back of the lighting device, i. on the surface of the back substrate 1 10, an antireflection layer 1 15 may be provided. In this way, the total transmission by the lighting device can be increased. The antireflection layers 15, 155 may be, for example, the dielectric multilayers or moth-eye structures.

In the lighting device illustrated in FIG. 1, consequently, the transparent hole regions 140 extend between the front side and the rear side of the lighting device. The hole regions 140 extend substantially perpendicularly through the luminescent layer 120 and the shielding layer 130. The structuring of the luminescent layer 120 and the shielding layer 130 is therefore substantially congruent, whereby specific deviations can be introduced, which are explained in more detail below.

As already mentioned, it should be avoided by the shielding layer 130 that light generated in the luminescent layer 120 is emitted in the direction of the rear side of the lighting device. For this reason, the shielding layer 130 has an edge region 132 around the hole regions 140, which protrudes beyond the luminescent layer 120. The edge region 132 preferably protrudes beyond the luminescent layer 120 by at least one micrometer. Typically, the width of the edge region 132 is chosen to be greater than the thickness of the luminescent layer 120. For example, if the luminescent layer 120 is only a few hundred nanometers thick, an edge region 132 projecting only a few micrometers beyond the luminescent layer 120 can be selected. However, an excessively wide width of the edge portion 132 should be avoided so as not to unnecessarily reduce the transparent hole portions 140.

In Fig. 1, the light generated by the lighting device is shown schematically by solid arrows 20. The light emitted by the illumination device strikes an object plane 50, which is typically spaced apart by the illumination device, and is scattered or reflected there. The scattered or reflected light emanating from the object plane 50 is illustrated in FIG. 1 by dashed arrows 30. It can be seen that due to the hole areas 140 in the lighting device, the reflected or scattered light 30 is transmitted toward the back of the lighting device.

Although the back substrate 110 and the layers of the illumination device formed thereon are shown as planar in FIG. 1, it will be understood that a domed or deformable structure may also be provided.

FIG. 2 schematically shows a plan view of the illumination device of FIG. 1. A region occupied by the illumination layer 120 is shown hatched. Furthermore, the edge regions 132 of the shielding layer 130 formed around the hole regions 140 can be seen.

As shown in Fig. 2, the transparent hole portions 140 are not continuous and formed in a square shape. However, other cross-sectional shapes are also possible for the hole regions 140, eg round, oval, rectangular, triangular angular, polygonal or strip-shaped. Furthermore, it is also conceivable for a hole region 140 in the plane of the luminescent layer 120 to have a different cross-sectional shape than in the plane of the shielding layer 130, as long as the edge region 132 protruding beyond the luminescent layer 120 extends around the entire hole region 140. In such a case, the edge region 132 would typically have a varying width along the circumference of the hole region 140.

Furthermore, it can be seen in FIG. 2 that the hole regions 140 are arranged in the plane of the shielding layer 130 as well as in the plane of the luminous layer 120 in a regular square grid. However, other arrangements are possible, such as a rectangular grid in which a distance between adjacent hole areas 140 in a first direction is different than a spacing of adjacent hole areas 140 in a second direction, a hexagonal grid, or an irregular or stochastic arrangement. For example, an irregular array may be advantageous to reduce the occurrence of moire effects. Furthermore, the transparent hole portions 140 need not all be formed with the same cross-sectional shape or size. A variation of cross-sectional shapes or sizes can also be used to reduce moiré effects.

The pitch of the hole regions 140 may be selected in the range of about 0.5 μm to 10 mm. However, in certain applications it is preferred that the patterning be visually imperceptible or barely perceptible. In this case, the distance between the transparent hole regions 140 may be less than 500 μm, in particular less than 100 μm.

Moreover, the proportion of the hole areas 140 on the total area of the luminescent layer 120, i. including the transparent hole areas 140, are selected in a wide range. This proportion determines the transmission of light through the lighting device. The proportion of the hole areas 140 on the total area of the luminescent layer 120 may be between 5% and 95%. In order to achieve a relatively high transmission, the proportion of the hole areas 140 on the total area is preferably 50% or more.

The illumination device can furthermore be designed in such a way that the radiation emitted by the luminescent layer 120, which is reflected on the outer surface of the transparent protective layer 150, due to total reflection in the Composite of back substrate 1 10 and transparent protective layer 150 remains trapped. In this way it can additionally be avoided that radiation generated by the luminescent layer 120 is scattered within the illumination device in the direction of the rear side of the illumination device and emitted on the rear side of the illumination device. For this purpose, the transparent protective layer 150 is made of a material having a specific refractive index of preferably n> 1.5, the back substrate 110 also having the definite refractive index of preferably n> 1.5. The transparent protective layer can be configured, for example, as a thin cover glass plate. The light generated by the luminescent layer 120, which is reflected on the outer surface of the transparent protective layer 150, can then be held by total reflection in the composite of back substrate 110 and transparent protective layer 150. In this case, it is advantageous that between the transparent protective layer 150 and the back substrate 110 there is a medium, for example optical cement, which has a similar refractive index as the transparent protective layer 150 and the back substrate 1 10. In this case, no light can shine on the Back of the lighting device exit from the back substrate 110, which has an angle to the solder of the outer surface of the back substrate 1 10, which is greater than a certain by the total reflection limit angle. When selecting a refractive index of n> 1, 5 for the back substrate 1 10 and for the transparent protective layer 150 and assuming air as the surrounding medium, this critical angle is 42 °. At the outer edges of the illumination device, absorbent layers may be applied as jet traps. When light is emitted from the luminescent layer 120 and reflected from the outer surface of the transparent protective layer 150 so as to be transmitted through the hole areas 140 toward the back of the illuminator, this light has an angle which is the distance of the outer surface of the illuminator transparent protective layer 150 to the luminescent layer 120 and the width of the edge regions 132 around the hole areas 140 results. If this angle is greater than the critical angle for the total reflection, the light can not escape from the back substrate 110. In this case, it would also be possible to dispense with an antireflection coating of the transparent protective layer 150. For example, when a transparent protective layer 150 having a thickness of 30 μm is used, assuming a total reflection angle of 42 °, no light can be transmitted through the outer surface of the back substrate 110 when the peripheral areas 132 around the hole areas 140 have a width greater than 40 have μm. The edge regions 132 are preferably designed with an absorbing surface on the side facing the front side of the illumination device, so that light reflected or scattered toward the rear side of the illumination device does not diffuse from the luminescent layer 120 due to multiple scattering or reflection through the hole regions 140 in the direction of the Rear side of the lighting device can get.

Fig. 3 illustrates another lighting device. The illumination device of FIG. 3 essentially corresponds to that of FIG. 1 and FIG. 2, wherein similar or identical elements have been designated by the same reference numerals. With regard to the properties of these elements, reference is made to the description of FIGS. 1 and 2.

In the lighting device of FIG. 3, the suppression of light emitted toward the back of the lighting device has been further improved. This improvement is based, on the one hand, on the measure that shielding walls 135 of an untransparent material are formed around the perforated areas 140. The shielding walls 135 extend from the shielding layer 130 toward the front side of the illumination device and are arranged in the plane of the luminescent layer 120 between the luminescent layer 120 and the hole regions 140. As shown, a height of the shielding walls 135 is selected to extend beyond the luminescent layer 120.

By the shielding walls 135, which are connected to the shielding layer 130, 120 beam traps are formed around the luminescent layer. The effect of the beam traps is that light emitted at large angles to the surface normal of the luminous layer 120 strikes the shielding walls 135 and is absorbed, scattered or reflected there. It is avoided that the light generated by the luminescent layer 120 in the region of the hole regions 140 strikes the protective layer 150 and is reflected from there in the direction of the rear side of the lighting device. For this purpose, the shielding walls 135 preferably extend to the protective layer 150.

The height of the shielding walls 135 is preferably selected depending on the extent of the luminescent layer 120 between the shielding walls 135. If, for example, the width of the luminescent layer 120 is approximately 50 μm between two adjacent hole regions 140, a height for the shielding walls 135 in the range between approximately 100 and 500 μm is preferably selected. The shield walls 135 may be made by various methods known in the art of microstructure, e.g. As embossing, injection molding, gluing, etc. In addition, known coating techniques, such as vapor deposition, sputtering, chemical coating, etc., are used. Preferably, the hole areas are formed in an intermediate substrate of transparent plastic, which is easy to pattern.

Furthermore, in the illumination device illustrated in FIG. 3, microlenses 160 are applied to the front side of the illumination device. In particular, the microlenses 160 are formed on the surface of the protective layer 150. As shown in FIG. 3, the microlenses 160 are arranged in such a way that they are arranged in front of the regions of the luminescent layer 120 lying between the hole regions 140. If, as shown in FIG. 2, the luminescent layer 120 is connected like a lattice, lattice-like cylindrical lens structures result for the microlenses 160.

Preferably, the extent of the microlenses 160 along the plane of the luminescent layer 120 is chosen to be greater than the extent of the luminescent layer 120 between two adjacent hole regions 140.

By means of the microlenses 160, the portion of the light generated in the luminescent layer 120 which is reflected on the outer surface of the protective layer 150 is reflected predominantly back in the direction of the luminescent layer 120. This proportion of the reflected light is shown schematically in FIG. 3 by a dashed arrow 20 '. It is thus avoided that light reflected on the outer surface of the protective layer 150 passes through the hole portions 140 toward the back of the lighting device.

Furthermore, the microlenses 160 can deflect and bundle the light emitted by the luminous layer 120, as a result of which the illuminance in the object plane can be adjusted. For example, the illuminance in the object plane can be partially increased.

The microlenses 160 may also be fabricated by known techniques of microstructure technology. It is understood that in addition an antireflection Layer may be formed on the protective layer 150 and over the outer surface of the microlenses 160.

4 schematically illustrates another lighting device. The lighting device corresponds in many respects to the lighting devices illustrated in FIGS. In Fig. 4, elements which are similar to those of Figs. 1 -3 are designated by the same reference numeral. For their properties, reference is made to the explanations in connection with Fig. 1 -3.

In the illumination device illustrated in FIG. 4, in addition to the luminescent layer 120, a further luminescent layer 125 is provided. The further luminescent layer 125 is made of a transparent material. In particular, the further luminescent layer 125 can be designed as an OLED luminescent layer.

The luminescent layer 120 and the further luminescent layer 125 are spatially separated from one another by an intermediate substrate 170. The hole regions 140 extend through the intermediate substrate 170 and the further luminescent layer 125, so that transparent hole regions 140, which extend through the luminescent layer 120, the further luminescent layer 125 and the shielding layer 130, are again formed between the front side and the back side of the illumination device. In the area of the intermediate substrate 170, the hole areas correspond to cavities which may be filled with air, another gas or a transparent material. The shielding walls 135 are applied to the inner surfaces of the cavities formed in the intermediate substrate 170 by suitable coating techniques. As shown, the shielding walls 135 are arranged between the luminescent layer 120 and the hole regions 140 and between the further luminescent layer 125 and the hole regions 140, so that beam traps for both the light generated by the luminescent layer 120 and for the light generated by the further luminescent layer 125 be formed. The shielding walls 135 and the shielding layer 130 may be designed to be reflective on their respective sides facing the luminescent layer 120 or the further luminescent layer 125. In this way, an improved yield of the light emitted from the luminescent layer 120 and the further luminescent layer 125 can be achieved.

The shielding walls 135 preferably extend perpendicular to the luminescent layers 120, 125, but may also have, within certain limits, an angle that deviates from 90 ° relative to the luminescent layers 120, 125. 4, the light emitted by the luminescent layer 120 is schematically represented by solid arrows 20, while the light emitted by the further luminescent layer 125 is shown schematically by dashed arrows 25. The backscattered or reflected light from the object plane 50 is shown schematically by dashed arrows 30.

In the illumination device illustrated in FIG. 4, light is emitted from the luminescent layer 120 in the direction of the front side of the illumination device. The light emitted by the light-emitting layer 120 radiates through the further light-emitting layer 125 and is emitted from the illumination device in the direction of the object plane 50.

The further luminous layer 125 radiates light both in the direction of the front side of the lighting device and in the direction of the rear side of the lighting device. However, due to reflecting surfaces behind the first luminescent layer 120 and on the shielding walls 135, the light generated by the further luminescent layer 125 can ultimately leave the lighting device only in the direction of the front side of the lighting device.

By using the further luminous layer 125, a significant increase in the emitted light output is possible. This represents a great advantage for many applications, in particular if both the luminescent layer 120 and the further luminescent layer 125 are implemented as OLED luminescent layers, which have a comparatively low luminance in comparison to other light sources, such as LEDs or incandescent lamps , which can be compensated by using multiple parallel luminescent layers.

Fig. 5 schematically illustrates another lighting device. The illumination device of FIG. 5 corresponds in many respects to the illumination devices illustrated in FIGS. In Fig. 5, elements corresponding to those of Figs. 1-4 are designated by the same reference numerals. With regard to the properties of these elements, reference is made to the corresponding description in connection with FIG. 1 -4.

5 is configured as a two-stage illumination device, which has a first luminescent layer 120 and a first further luminescent layer. Layer 125, which correspond to the luminescent layers 120, 125 of the illumination device of Fig. 4. In addition, however, a second further luminescent layer 126 is also provided, which is spatially separated from the first further luminescent layer 125 by a further intermediate substrate 190 and by an intermediate cover layer 180. The intermediate cover layer 180 is made of a transparent material and provided with an anti-reflection layer 185 on at least one of its surfaces. In the illumination device illustrated in FIG. 5, hole regions 140 between the front side and the back side of the illumination device extend through the luminescent layer 120, the first further luminescent layer 125 and the second further luminescent layer 126 and through the shielding layer 130.

The further intermediate substrate 190, like the intermediate substrate 170, is designed as a perforated plate, with the perforated regions 140 corresponding in each case to cavities in the intermediate substrates 170, 190. The cavities may be filled with air, another gas or a transparent material. On the inner walls of the cavities in the further intermediate substrate 190 further shielding walls 136 are formed, which extend in extension of the shielding walls 135. The further shielding walls 136 extend in such a way that they are arranged in the plane of the second further luminous layer 126 between the second further luminous layer 126 and the respectively adjacent hole area 140.

In FIG. 5, light emitted by the second further luminous layer 126 is illustrated by double-dashed arrows 26, while light reflected or scattered from the object plane 50 is illustrated by dot-dashed arrows 30.

The first and second further light-emitting layers 125, 126 are made of a transparent material. By way of example, the first and second further luminescent layers 125, 126 can each be implemented as an OLED luminescent layer.

As shown in FIG. 5, light is emitted from the second further light-emitting layer 126 both in the direction of the rear side of the lighting device and in the direction of the front side of the lighting device. The light emitted in the direction of the rear side of the lighting device is reflected on the surfaces of the shield walls 135, 136 and on the surface of the shielding layer 130, so that it can ultimately only leave the lighting device in the direction of the front side of the lighting device. Due to the multiple stages of the lighting device shown in Fig. 5, the available luminance can be further increased. In addition, the spectral distribution of the light emitted by the illumination device can be adjusted by means of the various illumination layers, ie the illumination layer 120 and the first and second further illumination layers 125, 126, by the illumination layers 120, 125, 126 having corresponding individual emission spectra to be selected. This can be advantageous, for example, for professional film recordings in which a color rendering index of more than 90 is required, which can be achieved efficiently by using several OLED luminous layers with individual emission spectra. In addition, the individual luminescent layers 120, 125, 126 are applied to different substrates, whereby they can be controlled separately with little effort. In this way, for example, the color rendering index can in turn be adjusted in a targeted manner or aging processes of the individual luminescent layers 120, 125, 126 can be compensated.

It is understood that the multi-stage of the lighting device illustrated with reference to FIG. 5 can be extended to any number of stages. In this context, it is advantageous to provide the best possible anti-reflection of intermediate cover plates (corresponding to the intermediate cover plate 180) used between the individual steps. For example, the Zwischenabdeckplatten can be provided on both sides with an antireflection coating.

6 schematically shows a plan view of a section of the intermediate substrates 170, 190 used in the illumination devices of FIGS. 4 and 5. As already mentioned, the intermediate substrates 170, 190 are made of a transparent material, which is hatched in FIG Surface is shown. In the transparent material, the hole areas 140 are formed as cavities. On the inner walls of the cavities, the shielding walls 135, 136 are formed by applying a layer of an untransparent material. A side of the shielding walls 135, 136 facing the luminescent layers 120, 125, 126, designated 137, is provided with a reflective or reflecting surface. A side of the shielding walls 135, 136 facing the hole areas 140, labeled 138, is likewise designed as a reflecting or reflecting surface. Alternatively, the side 138 of the shielding walls 135, 136 can also be made absorbent, for example with a blackened surface. The reflective design of the side 137 of the shielding walls 135, 136 on the one hand prevents light from passing through the shielding walls into the hole areas 140. At the same time, it is possible for the light, if appropriate after multiple reflection on the surface of the shielding walls 135, 136 or the upper surface of the shielding layer 130, to be emitted in the direction of the front side of the lighting device.

However, an absorbent configuration of the side 138 of the shielding walls 135, 136 may be advantageous for preventing light scattered on the intermediate cover plate 180 from being scattered toward the back of the lighting device. In addition, the quality of image capture by the hole areas 140, which could be affected by reflection at the sides 138 of the shielding walls 135, 136, can be improved.

Fig. 7 schematically illustrates another lighting device. The lighting device of Fig. 7 is substantially the same as that of Figs. 5 and 6. Elements of the lighting device of Fig. 7 which correspond to those of Figs. 1-6 are denoted by the same reference numerals. With regard to the properties of these elements, reference is made to the corresponding explanations to FIGS. 1-6.

In the illumination device of FIG. 7, a protective layer 150 is provided on the front side of the illumination device, which is provided with microlenses 160 on its surface. As explained in connection with FIG. 3, the microlenses 160 can further suppress the light backscattered in the direction of the rear side of the illumination device. In FIG. 7, light generated in the second further luminous layer 126, which is reflected inwardly on the surface of a microlens 160 in the protective layer 150, is denoted by 26 '. The microlenses 160 ensure that the backscattered light 26 'is directed into the region of the beam traps formed by the shielding walls 135, 136. The backscattered light is thereby effectively prevented from passing through the hole areas 140 to the back of the lighting device.

As explained in connection with FIG. 3, the microlenses 160 are arranged between the hole regions 140 and thus form a grid-like cylindrical lens structure. The extension of the microlenses 160 in the plane of Again, protective layer 150 is preferably selected larger than the width of the respective regions of the luminescent layers 120, 125, 126.

The luminescent layers provided in the illumination devices explained with reference to FIGS. 1 to 7 can consist of a plurality of electrically isolated partial regions, so that a plurality of separately controllable luminous regions result. If these separately controllable lighting areas are supplied with power via a passive or active matrix control, the lighting apparatus can be controlled to generate different areal illumination patterns. The lighting patterns can be used for decorative or functional purposes. For example, text or images can be generated. This can be used, for example, for advertising purposes, to display information or to issue warnings.

In the lighting devices illustrated in Figures 1-7, the dimensions of the structures in the various layers, e.g. Cross section of the hole areas, width of the webs of the luminescent layers, thickness of the various substrates, typically in the range of 1 -1000 microns. However, a range of 5-50 μm is preferred. The luminescent layers are typically thinner than 1 μm.

FIG. 8 shows an application example for the lighting device explained in connection with FIGS. 1-7.

In the application example illustrated in FIG. 8, the illumination device is arranged in spectacle lenses of a pair of spectacles 200. For example, the lighting device may be applied to an inner or outer surface of the lenses. Alternatively, the lighting device may also be embedded in the lenses. The glasses 200 may be configured as reading glasses, data glasses or surgical loupe. Consequently, the spectacle lenses can also be provided with suitable optical imaging properties. For example, the goggles 200 may be configured for viewing objects in close proximity. The illuminating radiation 20 emitted by the glasses 200 illuminates an object 250, for example the pages of a book or an operating field.

To supply energy to the lighting devices in the lenses of the glasses 200, a power source 220 is provided, for example a rechargeable battery or a battery. In the application example shown in Fig. 8 is the Power source 220 connected via a cable with the glasses 200. Alternatively, the energy source 220 may also be integrated in the goggles 200.

In the application example shown in FIG. 8, there are advantages in that the illumination device integrated in the spectacle lenses is very space-saving and lightweight, since it consists essentially of a coating of the spectacle lenses, this coating having a thickness of typically a few tenths of a millimeter at most. The already existing eyeglass lenses are thus used as a carrier substrate for the lighting device. The spectacle lenses may be specifically adapted and provided with an optical effect or not.

In the case of the glasses 200, lighting always takes place automatically where it is needed. The illumination radiation 20 is generated directly between the eye and the observed object. The illumination distribution can be further optimized by using microlenses, which are designed asymmetrically, in accordance with the arrangements shown in FIGS. 3 and 7, so that the illumination radiation 20 is given a preferential direction for the area of the typical visual field.

For specific applications, the illumination devices integrated in the lenses can also be designed such that they emit light in the ultraviolet spectral range, either in addition to light in the visible spectral range or exclusively. In this way it is possible to observe fluorescent objects. In this case, the spectacle lenses can also be provided with an additional spectral coating on the side facing the eye, which blocks ultraviolet radiation but allows visible radiation to pass. Applications for ultraviolet spectral irradiance illuminators include, for example, in bloodstain forensics research, in the study of fluorescent security features, e.g. in bills, or in geology.

Fig. 9 schematically illustrates another application example of the lighting device shown in Figs. 1-7.

In FIG. 9, the illumination device 100 is part of a camera objective 300 for a camera. The camera lens 300 includes a front lens 310 and optionally another lens 320 having one or more lenses or other imaging elements. The camera can be a movie camera or a video camera or act on a camera. The camera can be configured analog or digital.

The illumination device 100 is arranged in front of the front lens 310 of the camera lens 300. In this case, the lighting device 100 may be implemented using planar substrates.

Starting from the illumination device 100, the illumination radiation, illustrated by solid arrows 20, is emitted into the object plane 50. Starting from the object plane 50, scattered or reflected light, illustrated by a dashed arrow 30, is received by the illumination device 100 in the camera lens 300. The front lens 310 and the optional further optics 320 image the detected scattered or reflected radiation 30 onto an image pickup device, e.g. a photosensitive film or a photosensitive chip.

Fig. 10 schematically illustrates another embodiment of the illumination device described in Figs. 1-7.

In the application example shown in FIG. 10, the illumination device 100 is provided as part of an imaging optic 400. The imaging optics 400 comprises a front lens 410 and optionally further optics, which may consist of one or more further lenses or other imaging elements. The illumination device 100 is applied to the surface of the front lens 410 of the imaging optics 400. Due to the front lens 410 and the further optics, light detected by the imaging optics 400 is imaged onto a detector 450. The detector may, for example, be a camera. However, visual observation by the human eye is also possible. Optionally, a spectral filter 420 may be disposed in the optical path between the front lens 410 and the detector 450, e.g. between the front lens 410 and the further optic 430.

In the example of application shown in FIG. 10, the illumination radiation generated by the illumination device 100, shown schematically by solid arrows 20, is emitted in the direction of the object plane 50. Starting from the object plane 50, reflected or scattered light, schematically represented by a dashed arrow 30, is transmitted through the front lens 410 and the light applied thereon. Luminous device 100 recorded in the imaging optics 400 and imaged via the front lens 410 and the further optics 430 on the detector 450.

The imaging optics 400 may be, for example, a camera or video camera for close-ups. Due to the illumination device 100 applied directly to the front lens 410, a space-saving alternative to a lighting ring formed around a lens or to a separate illumination source is provided. With a sufficiently small structuring of the illumination device 100, impairments of the image quality due to the structures introduced into the beam path in the illumination device can be avoided since the illumination device is sufficiently far away from the object plane 50 to be sharply imaged.

Alternatively, however, similar to the example of use explained with reference to FIG. 9, the lighting device 100 can be reversibly attached to a lens as a pre-screw component. In this case, the illumination device can be applied to a substrate which is planar or has a curvature that deviates from the front lens 410. For example, the illumination device 100 can be applied to a substrate which is concavely curved, as a result of which an increase in illuminance in the center of the image can be achieved.

The spectral filter 420 may be used to filter unwanted spectral regions from the light detected by the imaging optics 400. This may in particular be radiation in the ultraviolet spectral range which is generated by the illumination device 100, for example in order to bring about fluorescence excitation in an object under examination. The spectral filter 420 may be a separate component of the imaging optics 400, which may optionally be configured interchangeable. Alternatively, the spectral filter 420 may be mounted on a lens or other optical element.

The arrangement shown in FIG. 10 may also be part of an endoscope with wide-field detection. Compared to a conventional illumination by means of a separate optical fiber or by means of a beam splitter again results here the advantage of a small footprint, which is of great importance in endoscopes. The arrangement shown in FIG. 10, however, may also be a part of a microscope, for example a stereomicroscope, a surgical microscope, a compound or wide field microscope or an ophthalmological microscope. Furthermore, it can be part of an industrial measuring device. The advantage over conventional lighting devices, in turn, is that little space is required and even with a small working distance in relation to the diameter of a lens used efficient lighting can be achieved.

When using the illumination device 100 in a microscope-like arrangement, it should be noted that the structured illumination device may not lie directly in the object plane 50 or an image plane conjugate thereto. This applies to lenses, zoom systems, reflected-light and transmitted light illumination arrangements. However, the illumination device 100 can be used in a pupil plane of the imaging optics, e.g. in the plane of a microscope aperture or in an accessible lens pupil. Here, through various areal illumination patterns, e.g. Rings, segments, half-pupils, etc., different microscopic contrasting methods are generated and continuously mixed by a dimming process, for example, with a bright field image or a dark field image. This results in advantages over a hard switching between different microscopic contrast methods. With a division of the planar illumination in half-pupils, a continuous connection of the spatial image contrast is possible.

A concrete application example of the illumination device 100 in a microscope is illustrated in FIG. 11.

FIG. 11 shows, by way of example, a stereomicroscope 500 in which the illumination device explained with reference to FIGS. 1-7 is arranged in front of the imaging optics. Starting from the illumination device 100, light is emitted onto an object 550 to be observed. Light reflected or scattered by the observed object 550 is detected by the illumination device 100 in the microscope 500 in an object of the microscope 500 and supplied to an observation section 510 of the microscope 500. For example, in the observation section 510, there may be eyepieces which allow a visual observation of the observation object 550 by the human eye. Alternatively or additionally, the observation section 510 may also be provided with a camera. In addition to the application examples already mentioned, the illumination device described with reference to FIGS. 1-7 can also be used in conjunction with matrix-like arrangements of miniature lenses. By the matrix-like arrangement of mini-lenses, for example, a 1: 1 image can be made on a camera chip. In such arrangements, which can be produced by means of a plurality of microlens arrays lying one above the other, a very large ratio of viewing area to working distance can be achieved. The diameter of the miniature lenses is typically less than 5mm. In this case, the illumination device described with reference to FIGS. 1-7 can be introduced between the camera chip and the object plane in order to realize a reflected light illumination.

In addition, the illumination device described with reference to FIGS. 1-7 can also be used for reflection-free illumination of images. For this purpose, a transparent protective material arranged in front of the image, e.g. a protective glass, are provided by a substantially the entire surface of the image covering lighting device with the explained with reference to FIGS. 1-7 properties. In this way, the image is illuminated very evenly and reflections from separate light sources on the transparent protective material are avoided. Since the use of OLED luminescent layers allows the illumination radiation emitted by the illumination device to be adjusted in terms of its spectral range such that it contains no components in the ultraviolet spectral range, the illumination device can also be used for objects sensitive to ultraviolet radiation, e.g. Paintings, photographs or the like, are used. By varying the spectral distribution of the emitted illumination radiation by an electrical control of the luminescent layer or the luminescent layers, the illumination can also be adapted effectively to the respective object to be illuminated and / or the environmental conditions. Furthermore, the brightness of the lighting is easily controllable. An automatic brightness control can be used in combination with a brightness sensor.

Another use of the illumination device described with reference to Figs. 1-7 is as part of a watch glass, e.g. to dial illumination.

In addition, the lighting device can also be used in showcases or cabinet doors as a light source. There are similar advantages to lighting images. In addition, there is also a use in glazed doors of Refrigerators or freezers, eg in food markets, possible. In this case, it proves to be an advantage over conventional types of illumination that OLED-based luminescent layers can produce light with high efficiency and low heat generation.

Furthermore, it is possible to use the illumination device explained with reference to FIGS. 1-7 for illuminating and optionally monitoring neighboring rooms through window panes. Here, an advantage results from the fact that a large-area illumination is realized, which causes no glare and illuminates an object to be observed or people to be observed exactly from the direction from which the observation is made. In the event that the observer or a camera used for observation purposes should not be visible, e.g. when monitoring in supermarkets or in interrogation rooms, the lighting device may be additionally provided on the side facing the observer with a partially transparent mirror layer.

A further field of application of the illumination device explained with reference to FIGS. 1 to 7 is found in optical copiers and scanners. Here it is currently customary to illuminate an object, e.g. a sheet of paper to draw a line-shaped light source over the object. The mechanical complexity associated therewith can be avoided by using the planar lighting device explained with reference to FIGS. 1-7, by realizing a substantially full-surface illumination of the object. The image recording can then take place through the illumination device. A further advantage is that the image acquisition can take place with a two-dimensionally configured camera, which in turn allows a higher copy or scan speed to be achieved. In this application example, the mean distance between the hole areas in the lighting device should preferably be less than 50 μm.

Another field of application concerns so-called teleprompters, with which lecturers can read their text without the text being able to be seen by the audience. Such Teleprompter be used in eg live events or television. Currently, teleprompters usually consist of a projector and a partially reflecting plate. The speaker sees the reflected, projected text, while the viewer sees only the partially reflecting plate. With the aid of the explained with reference to FIG. 1 -7 lighting device, the projector can be saved, since the text can be displayed directly with the lighting device according to the invention. For this purpose, the lighting device is to be designed such that it functions with a sufficient resolution as a text and / or image-representing display. As has been explained above, only partial areas of the lighting device have to be separately electronically controllable for this purpose. For this purpose, the usual in displays passive matrix method or active matrix method can be used.

Furthermore, the illumination device explained with reference to FIGS. 1-7 can also be used in reflective display devices, e.g. In LCoS (Liquid Crystal on Silicon) (LCoS) display devices, the illumination device can be placed a short distance in front of the reflective display device and a very flat design is made possible, in which case the reflective display devices also be used for large-area display, as a complex incident illumination with beam-forming elements is not required.In this application example, the average distance between the hole areas in the lighting device should be smaller than the pixels of the display device.

It is understood that the above-described implementations of the lighting device and application examples can be suitably combined with each other.

Claims

A lighting device comprising: a luminescent layer (120), a shielding layer (130) of an opaque material disposed between a back side of the lighting device and the luminescent layer (120), and a plurality of transparent hole regions (140) to which the luminescent layer (120 ) and the shielding layer (130) are perforated and which extend between the rear side and a front side of the lighting device, the shielding layer (130) each having around the hole areas (140) formed edge regions (132), which protrude beyond the luminescent layer (120) ,

2. Lighting device according to claim 1, wherein the edge regions (132) protrude by at least 1 micron on the luminescent layer (120).

3. A lighting device according to claim 1 or 2, comprising: shielding walls (135, 136) formed of the non-transparent material around the perforated areas (140), the shielding walls (135, 136) extending along a portion of the perforated areas (140) between the shielding layer (140). 130) and the front of the lighting device.

4. The lighting device according to claim 3, wherein the shielding walls (135) are connected to the shielding layer (130).

5. Lighting device according to claim 3 or 4 wherein the Abschirmwände (135) extend between the luminescent layer (120) and the hole areas (140).

6. The lighting device according to claim 3, comprising: at least one further luminescent layer (125, 126) made of a transparent material arranged between the luminous view (120) and the front side of the lighting device, wherein the hole regions (140) extend through the further luminescent layer (125, 126), and wherein the shielding walls (135, 136) extend between the further luminescent layer (125, 126) and the hole regions.

7. Lighting device according to claim 6, wherein the further luminescent layer (125, 126) is designed as an OLED luminescent layer.

8. A lighting device according to claim 6 or 7, comprising: an antireflective layer (155, 185) arranged between the further luminous layer (125, 126) and the front side of the lighting device.

9. Lighting device according to one of claims 5-8, wherein the shielding layer (130) and / or the Abschirmwände (135, 136) are designed reflective.

10. Lighting device according to one of claims 6-9, comprising: a transparent intermediate substrate (170, 190), on the surface of the further luminescent layer (125, 126) is applied.

11. A lighting device according to one of the preceding claims, comprising: a transparent protective layer (150) which is arranged on the front side of the lighting device.

The illumination device of claim 1 1, wherein the protective layer (150) comprises an antireflective layer (155).

13. The lighting device according to claim 11 or 12, comprising: a plurality of microlenses (160) disposed on the front side of the lighting device.

14. Lighting device according to claim 13, wherein the microlenses (160) are arranged between the hole areas (160).

15. Lighting device according to one of the preceding claims, comprising: a transparent back substrate (110) disposed between the shielding layer (130) and the back side of the lighting device.

16. Lighting device according to one of the preceding claims, comprising: an antireflection layer (1 15) on the back of the lighting device.

17. Lighting device according to one of the preceding claims, wherein the hole regions (140) in the plane of the shielding layer (130) in at least one direction have an extension of 500 microns or less.

18. Lighting device according to one of the preceding claims, wherein the hole regions (140) in the plane of the shielding layer (130) are arranged in a periodic grid.

19. Lighting device according to one of claims 1 -17, wherein the hole areas (140) in the plane of the shielding layer (130) are arranged irregularly.

20. Lighting device according to one of the preceding claims, wherein the lighting device (100) comprises a planar or a curved support substrate (1 10).

21. Lighting device according to one of the preceding claims, wherein in the plane of the luminescent layer (120) a plurality of luminous areas are provided, which are separately controllable.

22. Lighting device according to one of the preceding claims, wherein the hole regions (140) extend substantially perpendicular to the luminescent layer (120) and the shielding layer (130).

23. Optical device with a lighting device (100) according to one of the preceding claims.

24. An optical device according to claim 23, wherein the illumination device (100) is applied to an optical element of the optical device.

25. An optical device according to claim 24, wherein the optical element is a transmissive imaging element, a reflective imaging element or a beam splitter element.

26. An optical device according to claim 23 or 25, wherein the optical device is an endoscope, a microscope, a magnifying glass, a pair of glasses, a lens, a camera, a display device, a copier or a scanner.