DE102015209911A1 - Lighting device with semiconductor light source - Google Patents

Abstract

A lighting device (1) has at least one semiconductor light source (4), the semiconductor light source (4) being surrounded laterally by a light-permeable annular TIR body (8), the TIR body (8) being one of the at least one semiconductor light source (4). remote from the outside (10) having a TIR structure (11) and the TIR structure (11) is adapted to reflect inside incident thereon light (L) through a light exit opening (13) of the TIR body (8). The invention is applicable, for example, to retrofit lamps or modules, in particular for spot lighting, in particular with at least one LED as the semiconductor light source.

Description

The invention relates to a lighting device with at least one semiconductor light source. The invention is applicable, for example, to retrofit lamps or modules, in particular for radiators with large emission angles, in particular with at least one LED as the semiconductor light source.

There are known LED retrofit lamps to replace conventional MR16 halogen lamps, which are usually offered with nominal beam angles of 24 degrees, 36 degrees or even 120 degrees (full angle). These lamps with different nominal radiation angles are usually made of equal parts, with only the beam-expanding optical element being different. While for less than 120 degree nominal beam angles of the lamp, lenses are often used to set the proper nominal beam angle, for large nominal beam angles of about 120 degrees, the light emitted by the LED is used without main beam shaping.

In this case, light is also emitted by the LED at even larger angles than the nominal emission angle, for example in the case where the LED has at least approximately an emission property similar to a Lambertian emitter. However, because the same housing is used for large nominal radiating angles as for smaller nominal radiating angles, light emitted from the LED at very large angles (e.g., between 160 and 180 degrees) is blocked by the housing of the LED retrofit lamp. This leads to a decrease in the efficiency of the LED retrofit lamp.

To increase the efficiency, a reflector can be used to reflect the light incident on the housing for use as useful light. It is disadvantageous that the reflector is either an additional component or present as a coating of the housing, which is why a further manufacturing step is then required. In addition, reflective coatings are prone to chemical corrosion and, in particular on a plastic substrate, are often susceptible to delamination. Therefore, reflector-based solutions for cost, manufacturing and longevity reasons are disadvantageous.

Lamps are known in which, as an alternative to a reflector, a curved cover is provided, but this does not significantly reduce the amount of light blocked by the housing.

It is the object of the present invention to overcome the disadvantages of the prior art at least partially and in particular to provide a cheaper way of increasing a light output of a semiconductor light device, in particular an LED lamp, with simpler manufacturing means, which can also be formed long-term stable.

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 lighting device, wherein the semiconductor light source is circumferentially surrounded laterally by a translucent annular TIR body, the TIR body has an outer side facing away from the at least one semiconductor light source with a TIR structure and the TIR structure is formed on the inside light incident thereon through a light exit opening of the TIR body. The lighting device may thus in particular comprise at least one semiconductor light source, which is circumferentially surrounded laterally by a light-transmissive annular TIR body whose outer side facing away from the at least one semiconductor light source is a TIR structure for reflecting light incident on the inside. The light can thus escape through a light exit opening of the TIR body. In particular, an inner side of the TIR body may face the at least one semiconductor light source.

This lighting device has the advantage that the light emitted by the at least one semiconductor light source at strongly lateral emission angles no longer falls on the housing but is reflected by the TIR body (possibly also several times) and then - typically from the light exit opening - exit. The reflected light, since it is no longer absorbed, can be used as useful light, which increases the luminous efficacy. In addition, in such a TIR body can be dispensed with a coating for reflection, which increases the longevity. In addition, by eliminating the coating for light reflection consuming manufacturing steps are saved.

The lighting device may have a housing, on which the at least one semiconductor light source and possibly also the TIR body are arranged or mounted. The housing may be at least partially made of plastic.

Light emitted or emitted by the at least one semiconductor light source can either be directed directly (ie without impinging on the TIR structure) onto the light exit opening or at a large emission angle through the inside of the annular TIR body enter this and then fall from inside or inside of the TIR structure. At the TIR structure, the light is transmitted through inner Total reflection thrown back through the TIR body and then exits on the inside of the TIR body again. Since the light is emitted starting from the semiconductor light source only in a front or upper half-space, the light is blasted with each reflection further in the direction of the light exit opening, from which it emerges after a reflection or after multiple reflections. Therefore, therefore, a "virtual" Lichtabstrahlfläche is created at the light exit opening of the TIR body, which is increased in comparison to the at least one semiconductor light source and thus no longer hits the housing under a strong lateral Lichtabstrahlwinkel, but over it radiates.

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 multichrome (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. Also the at least one diode laser may be followed by a wavelength-converting phosphor, e.g. in a LARP ("Laser Activated Remote Phosphor") arrangement.

The at least one semiconductor light source may be exactly one semiconductor light source, in particular exactly one LED.

The annular TIR body has an annular basic shape that may be formed in plan view (eg, along a longitudinal axis or symmetry axis), for example, oval, annular, or angular (e.g., triangular, rectangular, hexagonal, etc.).

The annular TIR body may in particular have a hollow cylindrical basic shape. The annular TIR body has in particular on its outer circumferential surface on the TIR structure. The light exit opening is bounded or defined by an upper edge of the TIR body and may in particular correspond to an upper cover surface of the annular TIR body.

The at least one semiconductor light source is arranged in the region of a lower cover surface of the annular TIR body. For example, it may protrude partially into the annular TIR body or be disposed entirely within the annular TIR body. The lower deck surface may be bounded or formed by the lower edge of the TIR body.

The lighting device can in particular be fastened to its rear or rear region and, for example, to this end. at a rear end portion, a socket (e.g., an Edison socket or a bipin socket). The lighting device emits its light in particular predominantly forward or upward, for example in a front or upper half-space. The terms "rear" or "bottom" and "front" or "top" can be used generally analogously. In particular, a longitudinal axis of the lighting device may extend from the rear to the front and, in particular, coincide with a main emission direction of the lighting device.

It is a development that a lower edge of the TIR body corresponds to a bearing edge or a foot surface of the TIR body. The TIR body can thereby be placed on the same surface of the lighting device, e.g. a housing of the lighting device, rest as the at least one semiconductor light source.

The annular TIR body may be open on both top surfaces, open on one top surface and closed on the other top surface, or closed on both top surfaces.

The TIR body is particularly transparent. For example, the translucent TIR body may be made of plastic (e.g., PP, PMMA, ABS, PC, etc.) or glass. Glass has a particularly high resistance to aging and a particularly high refractive index. Plastic is particularly inexpensive and lightweight.

It is a development that the at least one semiconductor light source is arranged centrally to the TIR body, in particular on a longitudinal axis of the TIR body. This results in the advantage that the light beams emitted by the at least one semiconductor light source encircle the TIR structure uniformly irradiate and thus, for example, can be avoided in a simple way that for some areas of the TIR structure, the light rays incident there no longer fulfill the condition for the total internal reflection.

It is an embodiment that the lighting device has a bowl-shaped region with a bottom surface and an edge, the at least one semiconductor light source is arranged on the bottom surface and the TIR body is arranged between the at least one semiconductor light source and the edge. This allows a particularly simple structure. The bowl-shaped region corresponds in particular to a front region of the housing.

It is a development that the cup-shaped region is part of a housing of the lighting device. It is an embodiment that at least the cup-shaped region consists of plastic.

It is still a development that the floor surface is a flat or flat floor surface.

It is also a development that the edge of the cup-shaped area is an annular, in particular annular, edge.

In order to achieve a particularly high luminous efficacy, the TIR body can be so high that no light beam from the at least one semiconductor light source on the TIR body past the housing, in particular on the edge, can impinge.

In particular, the light exit surface of the TIR body is at least at the same height as the edge of the bowl-shaped region. In this case, a height can in particular be understood to mean a position along a longitudinal axis of the lighting device.

It is a development that the annular TIR body is open on the top and bottom, so has open bases.

It is still an embodiment that the annular TIR body has at least one practically not or not appreciably reflective coverage area covering a respective base area. The coverage area also allows the TIR body to provide protection, for example, to the at least one semiconductor light source.

It is a development that the at least one cover region has a (flat or curved) plate-shaped basic shape. The covering region can thus assume the function of a covering element, in particular for the at least one semiconductor light source.

It is a further development that the at least one cover region has been produced separately from the annular TIR body or from the annular region of the TIR body and has subsequently been connected to it.

It is a particularly inexpensive and robust development that the at least one coverage area has been made integral with that of its annular TIR area of the TIR body (i.e., not made separately). The TIR body equipped with the at least one coverage area may be e.g. have been produced as an injection-molded body.

The coverage area may be transparent or diffuse reflective. If it is diffusely reflective, it can e.g. be produced integrally with the annular TIR body by means of a two-component injection molding process.

It is a further embodiment that a cover region, starting from an edge-in particular from a bottom-side edge-of the annular TIR region of the TIR body is arched into an inner space of the annular TIR region. Such a coverage area may act as a compact dome-like cover.

It is a further development that the coverage area connects tightly to the annular TIR area of the TIR body, since in this way a particularly effective protection of the at least one semiconductor light source can be implemented. The coverage area can densely overhang the at least one semiconductor light source.

It is yet another embodiment that the TIR body has as a cover region a translucent cover plate which covers the light exit opening.

It is a development of the fact that the covering area tightly covers the light exit opening, which enables particularly effective protection of the at least one semiconductor light source. The cover plate can for this purpose connect to the upper edge of the annular TIR area. It can be flat or flat or curved.

It is also an embodiment that the cover plate is spaced from the light exit opening, for example via thin spacers. This provides the advantage that light can not enter the cover plate directly from the annular region of the TIR body. The cover plate is thus in particular by a gap of the annular area separated and mechanically connected only by local spacers (eg three or four spacers). Such a spacer can be made in one piece, for example as an injection molded part.

The cover plate can simultaneously serve as a cover plate for the housing, e.g. for the bowl-shaped area of the housing. So components can be saved and a production can be facilitated.

It is also an embodiment that the TIR structure in its circumferential direction has adjacent and in the longitudinal direction parallel to each other aligned V-shaped longitudinal grooves. Such a TIR structure is easy to produce and can reflect incident light rays virtually lossless and very uniformly in the circumferential direction. The longitudinal grooves are thus aligned in particular parallel or at least approximately to the longitudinal axis.

It is also an embodiment that the annular TIR body has a - in particular from bottom to top - widening basic shape. As a result, a maximum emission angle of the light beam emitted from the light exit surface can be reduced. In addition, it is thus possible to reduce a number of reflections on the TIR structure required for emergence, which is advantageous in particular for light beams which radiate almost horizontally.

The TIR structure may be rectilinear or curved in a cross-sectional view through the annular TIR body. It may be parallel or oblique with respect to a longitudinal axis of the TIR body.

It is a development that the lighting device is a lighting module.

It is still a development that the lighting device is a "light engine", i. a combination of at least one light module with an operating electronics, which may comprise, for example, a driver for the at least one semiconductor light source.

It is also a development that the lighting device is a lamp.

It is also an embodiment that the lighting device is a replacement or retrofit lamp. This can be used as a replacement for conventional lamps. For example, it can have a base which fits into conventional lamp sockets and is thus designed analogously to conventional sockets.

It is a development that the retrofit lamp is an incandescent retrofit lamp and is therefore designed to replace conventional incandescent lamps. For this purpose, the incandescent retrofit lamp may be a e.g. Edison socket or a bayonet socket.

It is also an embodiment that the retrofit lamp is adapted to illuminate a localized lighting area and, for example, generates no isotropic light emission. In particular, the retrofit lamp may have a large (nominal) emission angle, e.g. may be in a range between 90 ° and 140 °, in particular at about 120 °. Such a lamp may be referred to as a "spot lamp" without restriction of generality. Such a retrofit lamp can for example serve as a replacement for a halogen lamp, in particular of the MR type, e.g. of type MR16.

It is a development that the retrofit lamp is designed as a retrofit lamp to replace lamps, which are suitable for use in PAR lamps or other radiators with large beam angles.

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 view in side view of a sketch of a retrofit lamp;

2 shows in a view obliquely from above a section of the retrofit lamp 1 ;

3 shows one in a view from diagonally above 2 analog section of a retrofit lamp according to a first embodiment with a TIR body;

4 shows in plan view a section of the TIR body 3 with a path of a possible ray of light;

5 shows a sectional side view of another TIR body with respect to an LED; and

6 shows a sectional view in a view obliquely from above yet another TIR body.

1 shows a sectional side view of a sketch of a lighting device serving as a lamp in the form of, for example, an MR16 LED retrofit lamp 101 ,

The lamp 101 indicates at a rear end region of a housing with respect to a longitudinal axis S. 2 a pedestal 3 eg in the form of a GU5.3 pin header. The front side, and thus in the direction of the longitudinal axis S, is a semiconductor light source in the form of, for example, a white light emitting LED 4 arranged, in the middle and thus on the longitudinal axis S.

As well as in relation to a detail A more exactly in 2 shown is the case 2 front side as a frontally open cup-shaped area 5 educated. The bowl-shaped area 5 has a flat, circular bottom surface 6 on top of an upright annular rim 7 surrounded on all sides. The LED 4 is centered on the floor area 6 arranged and has a main emission or optical axis z, which coincides with the longitudinal axis S. The edge 7 For example, in lamps with low nominal beam angles, it can be used to hold a reflector. Also, the edge can 7 serve to hold a translucent cover such as a cover or a piston.

Again referring to 1 is - with respect to the longitudinal axis S - smaller radiation angles of the LED 4 emitted light L directly from the bowl-shaped area 5 radiated without going to the edge 7 hold true. At larger beam angles from the LED 4 emitted light L, however, hits the edge 7 and would be blocked there without further action and noticeably absorbed.

3 shows you one 2 analog section of an MR16 LED retrofit lamp 1 , The lamp 1 is similar to the lamp 101 constructed, but now also has a here annular TIR body 8th on top of the LED 4 laterally (ie, in a (x, y) plane of the LED 4 ) surrounds circumferentially. The TIR body 8th is between the LED 4 and the edge 7 arranged so that it has a direct line of sight from the LED 4 to the edge 7 prevented. The TIR body 8th consists of transparent plastic (eg PC or PMMA) or transparent glass. The LED 4 is centered in relation to the TIR body 8th arranged so that a center of the TIR body 8th lies on the longitudinal axis S.

An inside 9 of the TIR body 8th is the LED 4 facing and structureless, where they can be roughened microscopically for improved coupling and / or decoupling of the light L. The LED 4 opposite outside 10 has a TIR structure 11 on. The TIR structure 11 has in its circumferential direction contiguous and in the longitudinal direction (ie, in alignment of the longitudinal axis S) parallel to each other aligned V-shaped longitudinal grooves 12 on.

The LED 4 protrudes into an open lower deck area 14 of the TIR body 8th into or in the area of the lower deck area 14 completely in the TIR body 8th , The TIR body 8th can with its lower edge, the lower deck surface 14 spanned, on the floor surface 6 rest and be fixed there, for example.

As well as in 4 in plan view of a section of the TIR body 8th shown on the inside 9 incident light L in the TIR body 8th coupled and runs on the TIR structure 11 the outside 10 , The surfaces of the V-shaped longitudinal grooves 12 are angled so that the incident light L is reflected due to total internal reflection, here twice, then to the inside 9 to run back and be decoupled there again. Because that of the LED 4 on the TIR body 8th emitted light L is directed obliquely forward, it can thus be so long in the TIR body by TIR reflection 8th "ascend" until there is a light exit opening 13 serving, open upper deck surface reached. The light L is therefore no longer at the edge 7 absorbed (because it is the edge 7 not reached), but can be used as a useful light, which significantly increases a light output. For example, a radius of the TIR body 8th , an opening angle of the V-shaped longitudinal grooves 12 and their height can be adjusted as needed.

5 shows a sectional view in side view of another TIR body 18 in relation to a position of the LED 4 , The TIR body 18 For example, instead of the TIR body 8th with the lamp 1 be used.

The TIR body 18 has a transparent annular TIR region 19 on, similar to the TIR body 8th is formed, but now from the bottom to the top (ie, along a direction of the longitudinal axis S) is slightly rectilinear, resulting in a light emission through the light exit opening 13 facilitated.

The TIR area 19 can with its bottom edge 20 on the floor surface 6 rest or - eg for improved ventilation and thus for improved heat dissipation from the area of the LED 4 - a gap 21 to the floor area 6 exhibit. A light leak through the gap 21 is negligible, since the emission area of the LED 4 can be higher and also a light emission from the LED 4 perpendicular to the optical axis z is practically negligible small.

The front or top light exit surface 13 is of an upper translucent (transparent or translucent) and virtually non-reflective cover plate 22 covered, which is also the whole open front of the bowl-shaped area 5 can cover. For this purpose, the cover plate 22 eg front on the edge 7 rest. The flat cover plate 22 is here over a gap 23 from the light exit surface 13 spaced. The cover plate 22 is with the TIR area 19 manufactured in one piece or integrally (eg by means of the same casting mold) made of plastic, wherein the mechanical connection of these two parts 19 . 22 of the TIR body 18 through small integral spacers 24 is reached. This firstly air circulation to the LED 4 and second, undesirable light transmission from the TIR region 19 to the cover plate 22 suppressed. However, the cover plate can basically also directly to the TIR area 19 connect.

6 shows a sectional view in a view obliquely from above yet another TIR body 28 , The TIR body 28 For example, instead of the TIR body 8th with the lamp 1 be used.

The TIR body 28 has a transparent annular TIR region 29 on, similar to the TIR body 8th or the TIR area 19 can be shaped.

Starting from the bottom or bottom edge 20 of the TIR area 29 may be a translucent (especially transparent) coverage area 30 connect to the inside, the - eg spherical shell - in an interior of the TIR body 28 is arched. The coverage area 30 protects the LED 4 , wherein in a variant by a spacing of the bottom edge 20 from the bottom surface 6 a ventilation of the LED 4 is possible.

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.

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.

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

1

 lamp

2

 casing

3

 base

4

 LED

5

 Cup-shaped area

6

 floor area

7

 edge

8th

 TIR body

9

 Inside of the TIR body

10

 Outside of the TIR body

11

 TIR structure

12

 longitudinal groove

13

 Light opening

14

 Lower cover surface of the TIR body

18

 TIR body

19

 Annular TIR area

20

 Lower edge of the TIR body

21

 gap

22

 cover

23

 gap

24

 spacer

28

 TIR body

29

 TIR area

30

 coverage area

101

 lamp

A

 neckline

L

 light

S

 longitudinal axis

x

 Solid axis of the LED

y

 Solid axis of the LED

z

 Optical axis

Claims (11)

Lighting device ( 1 ), comprising at least one semiconductor light source ( 4 ), wherein - the semiconductor light source ( 4 ) laterally encircling a translucent annular TIR body ( 8th ; 18 . 19 ; 28 . 29 ), - the TIR body ( 8th ; 18 . 19 ; 28 . 29 ) one of the at least one semiconductor light source ( 4 ) facing away from outside ( 10 ) with a TIR structure ( 11 ) and - the TIR structure ( 11 ) is configured to light incident thereon inside (L) through a light exit opening ( 13 ) of the TIR body ( 8th ; 18 . 19 ; 28 . 29 ) to reflect. Lighting device ( 1 ) according to claim 1, wherein - the lighting device ( 1 ) a bowl-shaped area ( 5 ) with a bottom surface ( 6 ) and a border ( 7 ), - the at least one semiconductor light source ( 4 ) at the bottom surface ( 6 ) is arranged and The annular TIR body ( 8th ; 18 . 19 ; 28 . 29 ) between the at least one semiconductor light source ( 4 ) and the edge ( 7 ) is arranged. Lighting device ( 1 ) according to any one of the preceding claims, wherein the annular TIR body ( 8th ; 18 . 19 ; 28 . 29 ) at least one non-reflective coverage area ( 22 ; 30 ) having a respective base area ( 13 . 14 ) covers. Lighting device ( 1 ) according to claim 3, wherein a coverage area ( 30 ) starting from a bottom edge ( 20 ) of the TIR body ( 28 . 29 ) into an interior of the TIR body ( 28 . 29 ) is arched. Lighting device ( 1 ) according to one of claims 3 or 4, wherein the TIR body ( 18 . 19 ) as a cover area a translucent cover plate ( 22 ), which the light exit opening ( 13 ) covers. Lighting device ( 1 ) according to claim 5, wherein the cover plate ( 22 ) from the light exit opening ( 13 ) is spaced. Lighting device ( 1 ) according to one of the preceding claims, wherein at least the cup-shaped region ( 5 ) consists of plastic. Lighting device ( 1 ) according to any one of the preceding claims, wherein the TIR structure ( 11 ) in their circumferential direction adjacent and in the longitudinal direction (S) parallel to each other aligned V-shaped longitudinal grooves ( 12 ) having. Lighting device ( 1 ) according to any one of the preceding claims, wherein the annular TIR body ( 18 . 19 ; 28 . 29 ) has a widening basic shape. Lighting device ( 1 ) according to one of the preceding claims, wherein the lighting device is a retrofit lamp ( 1 ). Lighting device ( 1 ) according to claim 10, wherein the retrofit lamp has a nominal radiation angle in a range between 90 ° and 140 °.

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