DE102014200369A1 - Areal illuminator with planar light guide - Google Patents

Abstract

The surface illumination device (11) has at least one planar light guide (12), in particular light guide plate, and at least one extractor body (15) having a plurality of micro-optics (18), which micro-optics (18) each have a light entrance side (D) and one of the light entry side (D) have different light exit side (G), wherein the micro-optics (18) on a flat side (13) of the light guide (12) are arranged, at least some of the micro-optics (18) via their light entry sides (D) in optical contact with the Flat side (13) of the light guide (12) and the extractor body (15) on its side remote from the light guide plate (12) side (32) at least one light exit surface (22) for the micro-optics (18) shaped light (L). The surface illumination device is particularly applicable to backlighting, e.g. of screens or display ("backlighting"), for example of smartphones, laptop computers or televisions, for general lighting, e.g. in offices, for vehicle lighting such as taillights or daytime running lights, for signage applications, for copier and scanner lighting or for machine vision.

Description

The invention relates to a surface illumination device, comprising at least one planar light guide, in particular a light guide plate. The invention is particularly applicable to backlighting, e.g. of screens or displays ("backlighting"), for example of smartphones, laptop computers or televisions, for general lighting, e.g. in offices, for vehicle lights such as taillights or daytime running lights, for signage applications, for copier and scanner illumination and / or for machine vision.

Surface light guides play an important role in the backlighting of screens, including displays. In these, it is desirable to provide a directional radiation characteristic. According to the current state of the art, the light from a light guide for backlighting can not be directed, but only with broad radiation characteristics, e.g. approximately lambertsch, be decoupled. A directional radiation characteristic can be generated in practice by arranging an optical, angle-dependent filter in front of the light guide, which converts the non-directional radiation into a directed one, by retaining unwanted angular components of the light to a greater extent than desired angular components. Such a filter is also called BEF (Brightness Enhancement Film). However, this is not efficient.

Also contrary to use as lighting in the workplace is that according to the current state of the art no directional coupling of light from the planar light guide with high-quality glare and sufficiently high luminous flux can be realized inexpensively.

It is the object of the present invention to overcome the disadvantages of the prior art at least partially and in particular an improved possibility for directional coupling of light (including IR light and / or UV light) from a flat side of a planar light guide, in particular a light guide plate to provide.

This object is achieved according to the features of the independent claims. Preferred embodiments are in particular the dependent claims.

The object is achieved by a surface illumination device, comprising at least one planar light guide and at least one extractor body, which has a plurality of micro-optics, which micro-optics each have a light entrance side and a light exit side different from the light entry side, the micro-optics are arranged on a flat side of the light guide, at least some of the micro-optics are in optical contact with the flat side of the light guide via their light entry sides and the extractor body has on its side remote from the light guide plate at least one light exit surface for light formed by the micro-optics. As a flat side of the light guide is in particular that side of the light guide to understand, which has the largest surface area.

This surface illumination device has the advantage that in this way a light extraction from a flat side of the planar light guide can be achieved in a targeted manner in a plurality of micro-optics in a low-loss manner. The micro-optics enable a high-grade and precise direction of the light passing through them. Such a surface lighting device allows a high luminous flux and can also be produced with only a small effort.

The extractor body is in particular a coherent body, which simplifies its handling and attachment to the planar light guide. The micro-optics can also be understood as subregions of the extractor body. The micro-optics are thus in particular integrated into the extractor body so that they are connected to one another. This results in the further advantage that the micro-optics can be permanently positioned and aligned with each other very accurately. The extractor body may have been made in one piece or in several pieces.

A micro-optics is understood in particular to be an optical system, in particular an optical element, which has a small extent in all three dimensions. This excludes micro-optical structures which in one dimension have at least an order of magnitude greater expansion than in another dimension. Excluded thereby e.g. groove-like, linear or trench-like optical structures. Microoptics are to be understood in particular as optics with dimensions which are smaller by at least one order of magnitude, particularly preferably 2 or 3 orders of magnitude, than the extent of the entire lighting device. Typically, optical elements having dimensions on the order of less than 2 mm, in particular less than 1 mm, will be referred to as micro-optics.

Frequently, the size of the micro-optics depends on the accuracy with which it can be manufactured in particular relative to the size of the light source. To ensure the functionality of the micro-optics even with the given manufacturing tolerances, the size of the micro-optics is sufficient set large, usually by 1 to 2 orders of magnitude larger than the manufacturing tolerances.

A "light entry side" of a micro-optic may, in particular, be understood as that area of the micro-optic through which light enters the micro-optics. The light entry side may have a contiguous (light entry) area or a plurality of separate (light entry) areas.

A "light exit side" of a micro-optic may, in particular, be understood to be that area of the micro-optic through which light emerges from the micro-optic. The light exit side may have a contiguous (light exit) surface area or a plurality of separate (light exit) area areas. The light exit side may coincide with a surface of the extractor body and / or may be within the extractor body.

In particular, the light exit side has no overlap or coincidence with a light entry side; Light entry sides and light exit sides are thus separated from each other. As a result, light irradiated into a micro-optics through a light-entrance side is also not radiated back to a substantial extent (e.g., except for a slight Fresnel reflection) through a light-entrance side.

The light exit surface may be a continuous surface or may have a plurality of separate partial surfaces. The light emerging at the light exit surface of the extractor body may be a superposition of light from a plurality of micro-optics.

By "optical contact" may be understood in particular a physically light-conducting, in particular transparent, connection.

It is a development that the planar light guide is a light guide plate. A light guide plate is easy to produce and compact. The light guide plate may be flat or curved. However, the sheet light guide is not limited to a light guide plate but may be e.g. also be a significantly extended in all directions body with at least one flat (flat or slightly curved side).

It is still a development that the photoconductive material of the planar light guide is transparent. This keeps light losses in the planar light guide low. As the photoconductive material, for example, polycarbonate, PMMA, zeonex, other plastic (such as ABS, etc.), glass or silicone may be used.

The extractor body may also be made of plastic (e.g., polycarbonate, PMMA, Zeonex, etc.) or glass. Particularly preferred is a preparation of the extractor body - or at least its micro-optics - made of silicone, which allows finer structures than a normal plastic.

The extractor body may consist of the same material as the planar light guide, which facilitates a connection in separate production.

It is still a further development that the extractor body is a self-supporting body, in particular a rigid body. This simplifies handling and thus production, in particular in comparison to film-like bodies.

The fact that at least some of the micro-optics are in optical contact with the flat side of the light guide via their light entry sides may include in particular that all micro-optics are in optical contact with the flat side of the light guide via their light entry sides. Also included is the case that at least one of the micro-optics is not in optical contact with the flat side of the light guide, but at least one micro-optics of the extractor body is in optical contact with the flat side of the light guide. Thus, if the extractor body has n> = 2 micro-optics, [1, ..., n] of which may be in optical contact with the flat side of the optical fiber.

It is also a development that several micro-optics are arranged in an irregular or in a regular surface pattern, e.g. in a matrix pattern or in a tightly packed pattern.

It is still an embodiment that at least one of the micro-optics is a reflector. The reflector can redirect incident light by reflection, in particular by means of total internal reflection and / or by means of a reflective coated surface. Due to the reflector, a particularly strong directional effect can be achieved.

It is a further embodiment that at least one reflector is a shell reflector. A shell reflector allows a particularly simple way a strong directional effect perpendicular to the flat side of the planar light guide and / or a particularly targeted directional effect. Under a shell reflector may be understood in particular a reflector, which has a circumferentially closed reflection surface which separates a light inlet opening and a light exit opening from each other. The reflection surface expands in particular from the light entry opening to the light exit opening. It is a development that the reflector is a paraboloide, having spherical, frusto-conical, truncated pyramidal and / or free-form reflective surface. In the following, when a pyramidal shape or a conical shape is mentioned, in particular a truncated pyramidal shape or a truncated cone shape can also be understood. The reflective surface may be faceted or unfaceted.

It is an embodiment that the light entrance opening of the shell reflector is in optical contact with the flat side of the planar light guide. Thus, a high luminous flux from the flat side of the planar light guide is specifically made possible in the light inlet opening. The light entrance opening of the shell reflector thus corresponds in particular to the light entry side of the micro-optics.

It is a development that the shell reflector is a transparent solid body. Its reflection surface can be formed in particular by at least one surface of the extractor body. The reflection surface can act by means of total internal reflection reflective, the at least one acting as a reflection surface surface so be a TIR surface. Alternatively, the at least one reflective surface may be reflective coated, e.g. be metallized.

It is yet another embodiment that at least one shell reflector has a reflecting surface having the reflector shell, which is filled in the region of its light inlet opening with a transparent material, which is in optical contact with the flat side of the planar light guide. The reflector shell may therefore be at least partially hollow. This may simplify manufacture and save weight. The reflector shell itself does not need to be light-conducting. In this case, therefore, the extractor body may be integrally formed at least in two parts, specifically with the at least one reflector shell and the filling compound of the translucent material, which is inseparably bonded thereto, as different parts.

To produce such a surface lighting device, for example, at least one previously empty reflector shell may be placed with its light inlet opening on the planar light guide and subsequently at least partially filled with the light-transmitting material, in particular potted.

The reflector shell may in particular be a prefabricated reflector shell. The reflector cup may have been aftertreated on its inside for producing or improving a reflectivity, e.g. be covered with a reflective layer.

In the case of an extractor body having a plurality of reflector shells, the associated reflector shells may be e.g. be connected to each other via connecting webs. This component may e.g. made of plastic, in particular injection-molded plastic, as base material.

It is also an embodiment that at least one of the micro-optics is designed as a refractive transmitted-light element and thus in particular not or not mainly as a reflector. The transmitted light element may for example be a lens.

Generally, several micro-optics may be optically connected in series. For example, light emerging from a light exit side of at least one reflector may enter a light entrance side of a refractive light transmissive element, e.g. a microlens, invade. In particular, light emerging from a light exit side of precisely one reflector may be incident on a light entry side of precisely one refractive transmitted-light element. But it may also occur from a light exit side of multiple reflectors occurring light in a light entrance side of exactly one refractive transmitted light element and / or it may come from a light exit side of exactly one reflector emerging light in a light entrance side of several refractive transmitted light elements.

It is also an embodiment that the micro-optics in all three dimensions or spatial directions have a "microscopic" extension of less than 10 mm, in particular less than 5 mm. Particularly preferred is a maximum expansion, in particular of less than 1 mm, in particular less than 0.5 mm, in particular less than 0.2 mm, in particular less than 0.1 mm.

It is still another embodiment that at least one of the micro-optics (e.g., a reflector or a refractive transmitted-light element) is a transparent solid. Light is directed in particular in the solid body.

In particular, in the event that at least one of the micro-optics is a transparent solid body, it is a preferred embodiment for simple attachment, that at least one micro-optics at its light entrance side in a translucent bonding agent, which provides contact to the planar light guide is immersed. However, this is basically also possible for hollow shell reflectors, etc. The bonding agent is particularly transparent.

For attachment of the micro-optics like the associated planar light guide, for example, flat or only locally to a designated Contact area are covered with the translucent bonding agent. Subsequently, the micro-optics may be pressed into the primer until it has cured sufficiently. The immersed area may correspond to the light entry side of the micro-optics. A refractive index of the sheet light guide, the adhesion promoter and the micro-optic (s) is preferably similar or equal to avoid reflections at interfaces.

It is a development that at least one of the micro-optics on its side facing the flat side of the planar light guide side has a taper or tip and dips with its tip in the light-permeable bonding agent. The at least one micro-optic may e.g. a conical or pyramidal micro-optic. This development is particularly advantageous for quick and easy attachment of the extractor body.

It is also an embodiment that at least one of the micro-optics is attached to a flat side of the planar light guide. For example, such a micro-optic may be glued to the sheet-like light guide, fused (e.g., by laser light), or joined in some other way. This embodiment enables a particularly compact and simple attachment of the extractor body to the planar light guide. Particularly advantageous is an attachment by ultrasonic welding.

Alternatively, the extractor body may be pressed or pressed against the flat side of the lightguide plate and e.g. by means of at least one fastener (e.g., at least one clip or detent member).

It is also an embodiment that the planar light guide is integrally formed with at least one extractor body, e.g. by co-manufacturing in one piece, e.g. by casting. The extractor body may in particular be injection-molded with the planar light guide on its flat side, in particular in a construction as a plastic part.

It is still an embodiment that at least one of the micro-optics is not functional. Thus, the Lichtabstrahlmuster the surface lighting device can be varied even more varied in a simple manner. The lacking or lacking functionality can be achieved, for example, in that at least one of the micro-optics is not in optical contact with the planar light guide, e.g. by omitting an adhesion promoter in the area of this micro-optics. Another way to achieve the lack of or lack of functionality of a selected micro-optic may be e.g. comprise at least partial destruction or coverage of the micro-optics. Thus, it is still a further development that the extractor body has one or more non-functional - in particular subsequently rendered inoperative - micro-optics.

It is yet another embodiment that the surface illumination device has at least one semiconductor light source which is arranged to irradiate its light in an edge or a narrow side of the planar light guide. This allows a particularly low-loss light coupling in the planar light guide and a large uniform distribution of light in the planar light guide.

Preferably, the at least one semiconductor light source comprises at least one light-emitting diode. If several LEDs are present, they can be lit in the same color or in different colors. A color may be monochrome (e.g., red, green, blue, etc.) or polychrome (e.g., white). The light emitted by the at least one light-emitting diode can also be an infrared light (IR LED) or an ultraviolet light (UV LED). Several light emitting diodes can produce a mixed light; e.g. a white mixed light. The at least one light-emitting diode may contain at least one wavelength-converting phosphor (conversion LED). The phosphor may alternatively or additionally be arranged remotely from the light-emitting diode ("remote phosphor"). The at least one light-emitting diode can be in the form of at least one individually housed light-emitting diode or in the form of at least one LED chip. Several LED chips can be mounted on a common substrate ("submount"). The at least one light emitting diode may be equipped with at least one own and / or common optics for beam guidance, e.g. at least one Fresnel lens, collimator, and so on. Instead of or in addition to inorganic light emitting diodes, e.g. based on InGaN or AlInGaP, organic LEDs (OLEDs, for example polymer OLEDs) can generally also be used. Alternatively, the at least one semiconductor light source may be e.g. have at least one diode laser.

Another advantage of LEDs is that they allow a significantly higher luminance than low-pressure gas discharge lamps or fluorescent tubes.

In particular, when using LEDs for light irradiation in the planar light guide, it is advantageous because of the high luminance to make the micro-optics so small that the eye of a viewer can not resolve the structures from a typical viewing distance. This results in a viewer seeing a reduced effective luminance, which results from an averaging of luminous and no or only slightly luminous areas. Is the size of the Structures below the limit of resolution of the human eye give a qualitatively better impression than with larger structures. When using fluorescent tubes, however, it is not advantageous to use this effect, since the luminance is lower. It is particularly preferred that a dimension of a micro-optic is not more than 1 mm, preferably not more than 0.5 mm.

The radiating into the planar light guide LEDs can emit light of different colors. From the extractor body, a mixed light is then emitted which corresponds to a mixture of the light irradiated into the planar light guide and whose color corresponds to a color mixing of the colors of the different LEDs. Such color mixing is advantageous when using light-emitting diodes, since such a sum color location of the mixed light can be varied by simple means, e.g. towards a warm white humming color. In particular, in this case, it is advantageous for a uniform color mixing, if at least one edge region is present on the flat side of the planar light guide which faces the extractor body, on which there is no extractor body or no micro-optics. Consequently, no light is coupled out of this at least one edge region of the flat side into the extractor body. The edge region adjoins at least one narrow side or an edge of the planar light guide, in which LEDs radiate or couple light of different color. The differently colored light coupled in on this narrow side first passes through this edge region and is mixed there before it enters the region of the light guide which is provided with coupling-out structures.

Alternatively, or additionally, the light may be mixed by placing a light mixing element or a light mixing structure on the exit side of the extractor plate so that the light from the LEDs first the light guide plate, then the coupling-out micro-optics and then the light mixing structure or Light mixing component goes through.

Another advantage of effectively blending optics is that some of the LEDs, e.g. every second LED can temporarily switch off without impairing a color impression in order to save energy, which may be technically easier to implement than dimming.

An additional or alternative possibility for achieving a uniformly bright and optionally color-identical light exit surface is to make the narrow sides of the planar light guide highly reflective, where no LEDs are arranged, e.g. through a specular or diffuse reflective coating. As a result, the light travels a few times on average through the planar light guide before it is decoupled. Thus, it is achieved to evenly distribute the light in the planar light guide prior to decoupling, whereby a uniform, bright light emitting surface is achieved. This development may serve in particular as a replacement for the conventional method of homogenizing the brightness (specific light emission) of the light exit surface, which is to vary a size or a spatial density of the coupling-out structures in dependence on the position on the light guide plate. However, this conventional method alone is only of limited suitability in connection with the coupling-out, light-directing micro-optics, since it may lead to an insufficient optical contact area between the light guide and the micro-optics.

It is one for a specific variation of a luminous intensity distribution within the planar optical waveguide and thus a preferred embodiment for non-brightness-varied light emission of the surface illumination device that the surface illumination device comprises a plurality of semiconductor light sources, which at least partially have a different distance between two adjacent semiconductor light sources.

It is also a further development that a collimated light distribution or a so-called batwing light distribution is produced by means of the surface illumination device, e.g. to increase the efficiency of screens.

It is a development that the surface illumination device is a backlighting device, in particular for the backlighting of screens, including displays, especially displays of mobile devices such as smartphones, tablets, etc.

It is another development that the surface lighting device for room lighting, especially office or workplace lighting, is provided.

The surface lighting device may also be particularly advantageous to be used for vehicle lights, in particular for non-spotlight vehicle lights, e.g. for the realization of a tail light, a brake light, a daytime running light and / or an interior lighting.

Also, the surface lighting device can be used particularly advantageously for so-called "signage" applications or display devices, which likewise require particularly uniform illumination, such as display or light boxes ("light boxes") or signs, for example for advertising purposes.

In addition, the surface illumination device can be used particularly advantageously in the area of "machine vision", for example for machine defect detection under surfaces, dimensional and dimensional testing, position detection, surface inspection, object recognition, layer thickness measurements and / or completeness testing.

Furthermore, the surface illumination device can be used particularly advantageously as a lighting unit for scanners and / or copiers.

The above-described characteristics, features, and advantages of this invention, as well as the manner in which they will be achieved, will become clearer and more clearly understood in connection with the following schematic description of exemplary embodiments which will be described in detail in conjunction with the drawings. In this case, the same or equivalent elements may be provided with the same reference numerals for clarity.

1 shows a sectional side view of a section of a surface lighting device according to a first embodiment;

2 shows a sectional side view of a section of a surface lighting device according to a second embodiment;

3 shows an oblique view of a section of an extractor body of a surface illumination device according to the first or the second embodiment;

4 shows a sectional side view of a section of a surface lighting device according to a third embodiment;

5 shows an oblique view of a section of an extractor body of a surface illumination device according to the third embodiment;

6 shows a section in side view of a section of a surface lighting device according to a fourth embodiment;

7 to 10 show a sectional side view of a section of a surface lighting device according to a fifth to ninth embodiment;

11 shows in plan view a possible positioning of light sources on a surface illumination device; and

12 shows in plan view another possible surface lighting device.

1 shows a section in side view of a section of a surface lighting device 11 according to a first embodiment. The surface lighting device 11 has a planar light guide in the form of a planar light guide plate 12 with a first flat side 13 and a second flat side 14 on. At the first flat side 13 is a designed as a translucent solid body extractor body 15 attached, via one on the first flat side 13 applied layer of a translucent adhesion promoter 16 , The translucent adhesion promoter 16 may for example be a transparent adhesive. The light guide plate 12 and the extractor body 15 consist of a transparent base material such as glass or plastic (eg PMMA, PC, ABS, etc.). The light guide plate 12 and the extractor body 15 may consist of the same or a different basic material.

The extractor body 15 has a flat plate area 17 on, which at its the first flat side 13 the light guide plate 12 facing side has a plurality of protruding areas, which are micro-optics in the form of (micro) reflectors 18 serve. The reflectors 18 can also be referred to as reflector areas. The reflectors 18 are in particular in a regular surface pattern over this side of the extractor body 15 distributed, eg tightly packed in a matrix pattern. The reflectors 18 Here, purely by way of example, have a shape with a larger base area G and a smaller top surface D, in particular a spherical layer.

The reflectors 18 go at their larger footprint G in the flat plate area 17 over and are on their smaller top surface D on the translucent bonding agent 16 with the first flat side 13 the light guide plate 12 physically connected to light. The equivalent is that the reflectors 18 with the light guide plate 12 are optically connected without air gap. The respective top surface D serves as a light entry side or light entrance opening of the reflectors 18 , the respective base G as light exit side or light exit opening. The reflectors 18 Thus, they have light-permeable material on their cover surfaces D serving as light entry openings, namely the material of the extractor body 15 ,

For light irradiation, the surface illumination device 11 several LEDs 19 on, whose light L through at least one narrow side or an edge 20 the light guide plate 12 can be coupled into this. The light L is in the light guide plate 12 passed through total internal reflection and also on the flat sides 13 and 14 the light guide plate 12 , optionally also on a free surface of the bonding agent 16 , To avoid light loss is the refractive index of the adhesion promoter 16 similar or equal to the material of the light guide plate 12 ,

At the top surfaces D of the reflectors 18 However, the light L from the light guide plate 12 decouple and through the top surfaces D in the reflectors 18 pass. If the light L is on the free side walls 21 the reflectors 18 it is reflected there. The reflection may be, for example, due to an internal total reflection or due to a reflective design of the free side walls 21 , eg by providing a reflective layer.

Consequently, the light L passes (possibly down to a few Fresnel reflections) after passing through the reflectors 18 by their serving as light exit surfaces base G in the flat plate area 17 , Due to the reflection of strongly obliquely irradiated light L on the free side walls 21 the reflectors 18 points this into the flat plate area 18 entering light L angle, which is a total reflection at the light guide plate 12 facing away, as light exit (upper) surface 22 prevent serving side. As a result, the light L is incident on the light exit surface 22 of the extractor body 15 from the surface lighting device 11 out. Overall, this is from the light exit surface 22 emerging light beams due to the directivity of the (micro-) reflectors 18 narrower or narrower than that without the extractor body 15 from the flat sides 13 and 14 the light guide plate 12 decoupled light bundles.

2 shows a section in side view of a section of a surface lighting device 31 according to a second embodiment. The surface lighting device 31 is similar to the area lighting device 11 designed, except that the light guide plate 12 remote light exit (upper) surface 32 of the extractor body 33 not even, but is formed beam-forming. The light exit surface 32 has refractive transmitted light elements or transmitted light areas as micro-optics in the form of plano-convex lenses acting projections 34 on top of the reflectors 18 are arranged. An interface 35 to the flat plate area 17 like as a light entrance side of a projection 34 serve that to a head start 34 associated area 36 the light exit (upper) surface 32 as a light exit side.

The lenticular projections 34 allow, for example, a further beam focusing. Instead of lenticular projections 34 However, for example, even concentrator-like projections and / or Fresnel patterns, etc. may be present. The extractor body 33 thus has both a reflector structure and a lens structure.

In another way of looking at the reflectors 18 and the lenticular projections arranged above 34 together with the respective intermediate volumes 37 of the flat plate area 17 as uniform micro-optics 18 . 37 . 34 which have both a reflector function and a lens function. These uniform micro-optics 18 . 37 . 34 are by the interposed portions of the flat plate area 17 connected with each other.

That of this surface lighting device 31 radiated light can be particularly well collimated and improved deblind. In addition, an improved control of the luminous intensity distribution is made possible.

3 shows an oblique view from below of a section of the extractor body 15 or 33 the surface lighting device 11 or 31 , The reflectors 18 are arranged in a regular surface pattern, for example, with a hexagonal basic cell or alternately shifted by half a position rows.

4 shows a section in side view of a section of a surface lighting device 41 according to a third embodiment. The surface lighting device 41 is similar to the area lighting device 11 configured, however, have the reflectors serving as micro-optics 42 of the extractor body 43 a pyramidal basic shape. As in 4 shown, dip the tips of the (micro) reflectors 42 in the translucent adhesion promoter 16 one. Since the refractive indices of the light guide plate 12 , the translucent adhesion promoter 16 and the extractor body 43 are similar or practically the same, thereby the effective transfer of the light L from the light guide plate 12 through the translucent adhesion promoter 16 in the extractor body 43 allows. The light entrance opening or light entry side of a pyramidal reflector 42 So corresponds to his in the adhesion agent 16 immersed or the bonding agent 16 contacting area 44 , The free side walls 46 the reflectors 42 also form the reflection surfaces here. The base area 45 the reflectors 42 corresponds to its light exit side.

5 shows an oblique view from below of a section of the extractor body 43 with the arrangement of the reflectors 42 in a regular surface pattern.

6 shows a section in side view of a section of a surface lighting device 51 according to a fourth embodiment.

The surface lighting device 51 has an extractor body 52 on, which is a reflector pad 53 with several micro-optics in the form of partially empty reflectors 54 having. The reflector pad 53 is especially in the field of reflectors 54 formed reflective on the inside and thus provides the reflection surfaces 55 the reflectors 54 ready. The partially empty reflectors 54 lie with the edge of their serving as a light entrance side light entrance opening D or neck opening on the light guide plate 12 on. The reflector pad 53 may be made of plastic or metal, for example.

At the flat contact surfaces 57 between the reflector pad 53 and the light guide plate 12 it comes with not filled reflectors 54 to no transition of light L in the reflector pad 53 , eg due to significantly different refractive indices or by providing a reflective layer or reflective surface design in the region of the contact surface 57 ,

For an effective light transition from the light guide plate 12 in the light entry openings D of the reflectors 54 to reach are the reflectors 54 at least in the region of its light entry openings D with a translucent material 58 whose refractive index is a refractive index of the material of the light guide plate 12 is similar or similar, filled. The reflectors 54 have at their light entry openings D so translucent material 58 for light extraction from the light guide plate 12 on. In the present case, the reflectors 54 only partially with the translucent material 58 filled and thus have a free surface 59 on, reflected in the reflector 54 located.

During operation of the associated at least one light-emitting diode 19 is their light L in the light guide plate 12 passed through total internal reflection and can be at the interface between the light guide plate 12 and the translucent material 58 effectively decouple and through the interface in the reflectors 54 pass. If the light L there on the reflection walls 55 it is reflected. At the free surface 59 the light L emerges from the translucent material 58 because it does not satisfy the angular condition for total internal reflection. Slanted on the free surface 59 emitted light L can continue over free, not from the translucent material 58 occupied areas of the reflection walls 55 reflected and thus focused.

The reflectors 54 the surface lighting device 51 can be similar to the area lighting fixtures 11 . 31 and 41 be designed as a body with a more than two-fold rotational symmetry.

7 shows a section in side view of a section of a surface lighting device 61 according to a fifth embodiment. The surface lighting device 61 is similar to the area lighting device 11 designed, however, is the translucent adhesion promoter 16 now only locally in the area of the top surfaces D of the reflectors 18 available. Neighboring areas or "islands" of the adhesion promoter 16 do not touch each other.

interspaces 62 between the light guide plate 12 and the extractor body 15 can be filled by means of a medium M, which has a lower refractive index than the material of the light guide plate 12 and the extractor body 15 , The medium may be, for example, air, other gas such as nitrogen, water, oil, silicone, PMMA or magnesium oxide. The gaps 62 can to achieve a particularly effective internal reflection and / or for particularly strong attachment of light guide plate 12 and extractor body 15 be evacuated or under vacuum.

8th shows a section in side view of a section of a surface lighting device 71 according to a sixth embodiment. The surface lighting device 71 is similar to the area lighting device 11 designed, but now stand the light guide plate 12 and the extractor body 15 in direct contact with each other, without adhesion promoter 16 at the (micro) reflectors 18 ,

9 shows a section in side view of a section of a surface lighting device 81 according to a seventh embodiment. The surface lighting device 81 is similar to the area lighting device 71 designed, however, are the light guide plate 12 and the extractor body 15 Subareas of a unitary, one-piece component 12 . 15 , The component 12 . 15 For example, it may have been produced in a single production process, eg by casting, in particular injection molding. Alternatively, the light guide plate 12 and the extractor body 15 be prepared separately and connected in one piece, for example by laser welding or melting at the contact points or contact surfaces. Particularly suitable is ultrasonic welding.

10 shows a section in side view of a section of a surface lighting device 91 according to an eighth embodiment. The surface lighting device 91 is similar to the area lighting device 61 constructed, however, the extractor body 92 now no reflector areas, but only on the flat plate area 17 attached lenticular projections 34 as micro-optics on. The lenticular projections 34 are at the light guide plate 12 opposite side 93 of the flat plate area 17 of the extractor body 92 arranged, which serves as a light exit surface. For light coupling into the lens-like projections 34 from the light guide plate 12 are between the light guide plate 12 and the flat plate area 17 below the lens-like projections 34 localized areas or islands of the transparent adhesion promoter 16 present, through which the light L from the light guide plate 12 so in the flat plate area 17 occurs that a light leak from the extractor body 92 at the lenticular projections 34 happens. The Lichteinkopplung likes, inter alia, on the size or area of the bonding agent 16 be adjustable.

11 shows in plan view a possible arrangement of several, here: five, LEDs 19 a surface lighting device, such as a surface lighting device 11 . 31 . 41 . 51 . 61 . 71 . 81 or 91 in relation to the light guide plate 12 , The light-emitting diodes 19 are on one edge 20 the light guide plate 12 arranged and are perpendicular to the edge 20 aligned. The light-emitting diodes 19 have a partially different distance between two adjacent LEDs 19 on. Thus, a light emission pattern of the surface illumination device can be varied more or less. Alternatively, the light-emitting diodes 19 arranged equidistantly to each other.

12 shows in plan view another area lighting device 101 with several, here equidistant, LEDs 19 different colors, eg blue, red, green and yellow. The light-emitting diodes 19 emit their light in a narrow side or edge 20 one. One at this edge 20 adjoining border area 102 the first flat side 103 the light guide plate 104 is not from the extractor body 105 covered. Out of this edge area 102 Consequently, no light is in the extractor body 105 decoupled. That on this edge 20 Coupled differently colored light passes first through the edge area 102 and is mixed there before it's in one area 106 the light guide plate 104 enters with the extractor body 105 is provided. For further improved light mixing are all edges 20 the light guide plate 104 except for the light through the LEDs 19 necessary window designed to be highly reflective. The extractor body 105 likes, for example, analogous to the extractor bodies described above 15 . 33 . 43 . 52 , or 92 be educated.

Although the invention has been further illustrated and described in detail by the illustrated embodiments, the invention is not so limited and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Thus, the extractor body for varying the Lichtabstrahlmusters additionally or alternatively at least one non-functional micro-optics, eg reflector, 18 . 42 . 54 and / or lens 34 , exhibit. This may be caused, for example, by destruction or by a blocked optical connection of the reflector to the light guide plate 12 happen. The prevented optical connection may be with a reflector 54 eg be achieved by not using the material 58 is filled. In the pyramidal reflector 42 eg local no adhesion agent 16 to be available.

Generally, "on", "an", etc. may be taken to mean a singular or a plurality, in particular in the sense of "at least one" or "one or more" etc., unless this is explicitly excluded, e.g. by the expression "exactly one", etc.

In general, features of the various embodiments can be used alternatively or in combination with one another, eg a pyramidal reflector according to FIG 4 with a lenticular projection according to 2 , Instead of a pyramidal reflector, for example, a conical reflector, etc. may also be used.

Also, a number may include exactly the specified number as well as a usual tolerance range, as long as this is not explicitly excluded.

LIST OF REFERENCE NUMBERS

11

Surface lighting device

12

Light guide plate

13

first flat side

14

second flat side

15

Extraktorkörper

16

translucent adhesion promoter

17

flat plate area

18

reflector

19

led

20

Edge or narrow side

21

free sidewall

22

Light-emitting surface

31

Surface lighting device

32

Light-emitting surface

33

Extraktorkörper

34

head Start

35

interface

36

to the area belonging to a projection

37

Volume of the flat plate area

41

Surface lighting device

42

reflector

43

Extraktorkörper

44

Area

45

area

46

free sidewall

51

Surface lighting device

52

Extraktorkörper

53

reflector support

54

empty reflector

55

reflecting surface

57

contact area

58

translucent material

59

free surface

61

Surface lighting device

62

gap

71

Surface lighting device

81

Surface lighting device

91

Surface lighting device

92

Extraktorkörper

93

Side of the flat plate area

101

 Surface lighting device

102

 border area

103

 first flat side

104

 Light guide plate

105

Extraktorkörper 106 Area of the light guide plate

D

cover surface

G

Floor space

L

light

M

medium

Claims (22)

Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ), at least comprising - a planar light guide ( 12 ; 104 ), in particular light guide plate, and - at least one extractor body ( 15 ; 33 ; 43 ; 52 ; 92 ; 105 ), which has a multiplicity of micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ), which micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ) each have a light entry side (D; D, 35 ; 44 ) and one from the light entrance side (D; D, 35 ; 44 ) different light exit side (G; G, 36 ; 45 ), wherein - the micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ) on a flat side ( 13 ; 103 ) of the light guide ( 12 ; 104 ), at least some of the micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ) via their light entry sides (D; D, 35 ; 44 ) in optical contact with the flat side ( 13 ; 103 ) of the light guide ( 12 ) and - the extractor body ( 15 ; 33 ; 43 ; 52 ; 92 ; 105 ) at its from the light guide plate ( 12 ; 104 ) facing away ( 22 ; 32 ; 93 ) at least one light exit surface ( 22 ; 32 . 36 ; 59 ; 93 . 36 ) for the micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ) has shaped light (L). Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to claim 1, wherein at least one of the micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ) a reflector ( 18 ; 42 ; 54 ). Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to claim 1, wherein at least one of the micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ) a reflector ( 18 ; 42 ; 54 ), which redirects light (L) by total internal reflection. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of claims 2 or 3, wherein the reflector ( 18 ; 42 ; 54 ) is a shell reflector whose serving as a light entrance side light inlet opening (D; 44 ) with the flat side ( 13 ) of the planar light guide ( 12 ) is in optical contact. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to claim 3, wherein the reflector ( 42 ) is pyramidal or conical and a tip thereof in optical contact with the flat side ( 13 ) of the light guide plate ( 12 ) stands. Surface illumination device ( 51 ) according to claim 3, wherein at least one shell reflector ( 54 ) has a reflector shell, which has a reflection surface and which in the region of its light inlet opening (D) with a light-transmitting material ( 58 ) is in optical contact with the flat side ( 13 ) of the planar light guide ( 12 ) stands. Surface illumination device ( 31 ; 91 ; 101 ) according to one of the preceding claims, wherein at least one of the micro-optics ( 34 . 102 ) is configured as a refractive transmitted light element, in particular a lens. Surface illumination device ( 31 ; 91 ; 101 ) according to one of the preceding claims, wherein the micro-optics ( 18 ; 18 . 34 ; 42 ; 54 . 58 ) have at least in all three dimensions an extent of less than 10 mm, in particular less than 5 mm, in particular less than 1 mm, in particular less than 0.2 mm. Surface illumination device ( 41 ) according to one of the preceding claims, wherein at least one of the micro-optics ( 42 ) at its light entry side into a light-transmitting adhesion promoter ( 16 immersed), which the optical contact to the flat side ( 13 ) of the light guide plate ( 12 ). Surface illumination device ( 51 ) according to one of the preceding claims, wherein at least one of the micro-optics ( 52 . 54 . 58 ) is designed as a linear micro-optics. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 91 ; 101 ) according to one of the preceding claims, wherein at least one of the micro-optics with its light entry side ( 18 ; 18 . 34 ; 42 ; 54 . 58 ; 102 ) on a flat side ( 13 ) of the planar light guide ( 12 ) is attached. Surface illumination device ( 71 ) according to claim 11, wherein the flat side ( 13 ) of the light guide ( 12 ) With the extractor body ( 15 ) is connected by ultrasonic welding. Surface illumination device ( 81 ) according to one of the preceding claims, wherein the planar light guide ( 12 ) is integrally formed integrally with the extractor body. Surface illumination device ( 11 ; 31 ; 41 ; 61 ; 71 ; 91 ; 101 ) according to one of the preceding claims, wherein at least one micro-optic ( 18 ; 18 . 34 ; 42 ; 102 ) is formed as a translucent solid. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of the preceding claims, wherein the surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) at least one semiconductor light source ( 19 ), which is arranged to move its light (L) into an edge ( 20 ) of the planar light guide ( 12 ). Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to claim 15, wherein the surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) several in one edge ( 20 ) of the light guide ( 20 ) radiating semiconductor light sources ( 19 ), which at least partially different distances between adjacent semiconductor light sources ( 19 ) exhibit. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of the preceding claims, wherein it is a backlighting device for backlighting screens. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of claims 1 to 16, wherein it is provided for room lighting. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of claims 1 to 16, wherein it is a vehicle lighting device. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of claims 1 to 16, wherein it is a signage surface illumination device. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of claims 1 to 16, wherein it is a lighting unit for scanners and / or copiers. Surface illumination device ( 11 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91 ; 101 ) according to one of claims 1 to 16, wherein it is a machine vision lighting unit.

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