EP2824379A1 - Lamp - Google Patents

Abstract

The present invention relates to a lamp, in particular a retrofit lamp provided with a lamp base, with an associated with the lamp base, at least partially transparent closed envelope, which is designed to act as a heat sink for the lamp, with a lighting arrangement, which a variety of optoelectronic devices disposed within the envelope in a 4-Anordnung arrangement to act in all spatial directions, with a gaseous heat transfer medium placed inside the envelope and adapted to receive thermal energy generated by the illuminant assembly the hull acting as a heat sink to transport, wherein the gaseous heat transfer medium is provided as the only gas in the shell and the molecules of the gaseous heat transfer medium each having at least three atoms.

Description

FIELD OF THE INVENTION

The present invention relates to an LED-based lamp, in particular a so-called retrofit lamp.

TECHNICAL BACKGROUND

An incandescent lamp is an artificial light source in which an electrical conductor is heated by electric current and thereby excited to shine. The widespread design of this incandescent lamp with screw base is colloquially referred to as a light bulb due to the shape of the glass bulb. Conventional incandescent lamps generally consist of a socket including the electric power supply in the squeeze foot and a glass bulb, which shields the filament and its holder from the outside environment. Such incandescent lamps have a relatively low luminous efficacy and high thermal radiation, and therefore low energy efficiency, so that the majority of the electrically supplied energy is emitted in the form of heat energy and only to a lesser extent in the form of light. For this reason, among other things, since the beginning of 2008, production and distribution bans for incandescent lamps with low energy efficiency have been implemented in stages in the European Union on the basis of the Ecodesign Directive 2005/32 / EC.

When looking for replacement products of incandescent bulbs, it is important to remember that these replacement products can be used in existing luminaires without requiring a change in the wiring of the luminaire. This should apply to both conventional ballasts (CCG) and electric ballasts (IVG), and also to dimmable systems.

For the replacement of incandescent lamps are increasingly used on light emitting diode (LED) based lamps. A light-emitting diode (or "LED" for short) is a light-emitting semiconductor component whose electrical properties correspond to those of a diode. If electrical current flows through the diode in the forward direction, it emits light, infrared radiation or also UV radiation with a wavelength dependent on the semiconductor material and the doping of the particular semiconductor material used.

In contrast to the conventional incandescent bulb with glass bulb, filament and socket LEDs are not temperature radiators, so that their luminous efficacy is very high. LEDs emit light in a limited spectral range that is nearly monochrome. In addition, they are characterized by a very long life, are insensitive to shocks and do not require a hollow body that could implode. Meanwhile, LEDs are also available with sufficiently high light output, so that they can also be used for applications with high light radiation. At the time of registration, the available luminous flux of LEDS is so high that, with a comparable size and comparable production costs, even with an electrical comparison, they can increasingly compete with incandescent lamps.

As part of the implementation of the Ecodesign Directive 2005/32 / EC, so-called retrofit lamps are increasingly being offered, which are light sources that resemble the design of a known incandescent lamp and thus have a lamp base, which is used in a conventional light socket can be. Such retrofit lamps are often mentioned in the literature, for example in the DE 20 2013 000 980 U1 and the DE 10 2009 035 515 A1 , For LED based Retrofit lamps are the corresponding LEDs arranged inside the glass bulb, for example in the DE 20 2011 000 010 U1 , of the DE 20 2013 000 980 U1 and the DE 10 2007 038 216 A1 are described.

The present invention, as well as the idea underlying it, will be explained below with reference to such an LED-based retrofit lamp, but without the invention being restricted thereto.

LED based lamps typically require a heat sink to dissipate the heat selectively generated by the plurality of LEDs used and to prevent overheating of the LEDs from adversely affecting their function and life. The LEDs are therefore usually coupled to a heat sink. Due to the heat sink, there are limitations in the design and placement of the LEDs within the glass bulb of the lamp. Since LEDs - within a respective opening angle - can only emit light in one direction, the light shading of the rear side of the LEDs, which is not present in the case of a filament of an incandescent lamp, results. Nevertheless, to send out light in all directions, there are various solutions:

In the DE 20 2013 000 980 U1 the LEDs are each arranged on a plane perpendicular to the longitudinal axis of the lamp plane, so that this lamp preferably emits a light beam directed in the lamp longitudinal axis, but not light in all directions.

In the DE 20 2011 000 010 U1 The mounted on a heat sink LED components are distributed in different directions in the space inside the glass bulb. However, such a relatively massive heat sink structure in the interior of the glass bulb for design reasons, not very appealing. In the DE 10 2007 038 216 A1 is formed in the glass envelope of the lamp, a part-spherical body having recesses on its peripheral surface, which are formed as a support for the LEDs. Here, too, a radiation of light in all directions is possible, but this solution is not very attractive for design reasons, since this hemispherical body is visible from the outside.

Furthermore, from the EP 2 535 640 A1 an LED light bulb known. The LED light bulb has an LED strip with LED chips, which is attached to a core column. An incandescent lamp envelope and the core column form a chamber which is filled with a gas having a low viscosity and a high thermal conductivity coefficient. The gas is helium or hydrogen. It is also possible to use a mixture of helium and hydrogen. Helium has the disadvantage that it is relatively expensive. Furthermore, helium and hydrogen have a low molecular weight and can absorb little heat and dissipate accordingly slower.

In the US 2010/0207501 A1 In addition, an LED lamp is described in which LEDs are connected to a heat sink made of metal and arranged in an at least partially transparent housing. The housing is filled with a gas which has a greater heat capacity than air. As a gas while a noble gas, in particular helium is filled into the housing. A fan means generates in the housing a gas flow to transport heat generated by the LED light source to an inner surface of the housing. The heat sink has the disadvantage that there are restrictions in the design and the arrangement of the LEDs within the housing. As previously described, noble gases such as helium, relatively expensive and can also store less heat.

Next is in the EP 1 471 564 A2 discloses an LED lamp having a translucent envelope. The shell is filled with a gas of low molecular weight, including helium or hydrogen. Helium is expensive, however, and helium and hydrogen can absorb only little heat and dissipate heat accordingly slower.

The WO 2011/098358 A1 describes a lamp having an LED light source located on a support. The LED light source and the carrier are mounted in a gas-tight container, wherein the vessel is at least partially translucent. Within the vessel is a gas mixture of at least one gas having a high thermal conductivity, such as helium or hydrogen, and at least one gas having a different physical property to perform other functions, such as pressure equalization and light filtering. Although the amount of helium used can be reduced by the gas mixture, but a gas mixture of at least two gases must be produced, which is associated with additional production costs.

SUMMARY OF THE INVENTION

Against this background, the present invention has the object to provide a particular design-technically improved lamp with improved heat dissipation.

According to the invention this object is achieved by a lamp having the features of patent claim 1.

Accordingly, a lamp, in particular a retrofit lamp is provided with a lamp base, with one with the lamp base connected, at least partially transparent closed envelope, which is designed to act as a heat sink for the lamp, with a lighting device containing a plurality of optoelectronic devices, which are arranged within the shell in such a 4π arrangement that they in all spatial directions act, with a single gaseous heat transfer medium, which is introduced in the interior of the shell and which is adapted to transport generated by the lamp arrangement thermal energy to the acting as a heat sink shell, wherein the gaseous heat transfer medium is provided as a single gas or single gas in the shell and the molecules of the gaseous heat transfer medium each have at least three atoms.

The finding of the present invention is that a heat sink provided especially for cooling the heat generated by the LED components on the one hand requires a relatively large space requirement in the interior of the lamp. In addition, due to the required cooling effect, these relatively large heat sinks are typically visible from the outside through the transparent or partially transparent envelope, which is not very appealing for design reasons.

The idea of the present invention is now to dispense with such massive, required for cooling the optoelectronic devices heatsink. For cooling the already existing shell of the lamp is used as well as a single provided inside the shell large molecular gas filling, wherein the molecules of the filling gas thereby have at least three atoms. This formed as a heat transfer medium large-molecular gas filling absorbs the output of the respective optoelectronic devices thermal energy and transports them to the relatively large-scale shell, which the heat to the outside can deliver. Furthermore, the heat transfer medium designed as a large molecular weight filling gas can store larger amounts of heat than low molecular weight gas, such as helium and hydrogen. As a result, the filling gas can transfer more heat and the heat can be dissipated more quickly via the shell. In addition, organic gases such as propane, butane, etc., which are less expensive than helium and helium mixtures, can be used as large-molecular gases. The same applies to inorganic gases such as carbon dioxide. By filling the envelope with a single gas, ie only a single gas, it is possible to dispense with the production of a gas mixture. Furthermore, the filling gas has the function of storing the largest possible amount of heat as a large molecular weight filling gas. Noble gases such as helium, as well as gases such as hydrogen have a high thermal conductivity λ and thus can conduct heat well. However, you can save only small amounts of heat, as already stated.

It can thus be relatively inexpensive lamps provide that can be produced easier and less expensive due to the elimination of the comparatively large and beyond heavy heat sink, and the elimination of the use of noble gases such as helium, and the elimination of gas mixtures.

In addition, the lamps according to the invention are also advantageous for design reasons, since only the corresponding optoelectronic components are visible from the outside, but not the less responsive heat sinks.

Preferably, the lamp is designed as a retrofit lamp. A retrofit lamp is understood to mean a lamp which has a pear-shaped shell, so that this lamp has a light bulb-like design.

The term "acting" in the context of claim 1, in the case of an optoelectronic component designed as an LED, denotes the emission of light from the optoelectronic component to the outside. In the case of an optoelectronic component designed as a sensor, the term "act" denotes the ability to be able to record a measurement parameter, for example light.

Advantageous embodiments and further developments will become apparent from the other dependent claims and from the description with reference to the figures of the drawing.

The heat transfer medium has a relatively large heat capacity. In particular, the heat transfer medium or the sole gas filled in the shell has a molar heat capacity of greater than 30J / (mol * K) at 25 ° C and in particular greater than 35J / (mol * K) at 25 °, preferably greater than 37J / (mol * K) at 25 ° C and more preferably greater than 50J / (mol * K) at 25 ° C. The heat capacity indicates how much thermal energy a heat transfer medium absorbs or releases based on the temperature change.

The heat transfer medium is the only filled in the shell gas, ie single gas, designed as a relatively large molecular weight gas. The molecules of the heat transfer medium each have at least three atoms as a large molecular weight gas. The heat transfer medium is designed to transport thermal energy generated by the optoelectronic components, for example by convection, to the casing which acts as a heat sink. In a preferred embodiment, the heat transfer medium is formed as an organic gaseous compound, ie organic gas. Such an organic gas is, for example, methane, ethane, propane, butane, pentane, etc. The invention is not limited to these large molecular and organic gases. Furthermore, you can also large molecular and inorganic gases are filled as the only filling gas in the shell, such as carbon dioxide and Sulfurhexafluorid. The shell is not permeable to the filled in the shell single gas or single gas and made for example of glass, ceramic and / or plastic. Depending on the function and intended use, the casing may be provided with an additional coating.

In a preferred embodiment, the thermal energy generated by the lamp arrangement is transported by convection to the acting as a heat sink envelope. The heat transfer takes place here without additional funds only due to the heat generated by the heat. Thermal convection, often simply referred to as convection, in this case refers to the carrying of thermal energy or, in other words, a change in location of easily movable, gaseous molecules that carry stored heat with them. In this way, in contrast to previously known solutions to be provided for cooling massive massive heatsinks are omitted, since their function by already existing means, in particular by the filling gas itself and the lamp shell, are met.

In a likewise preferred additional or alternative preferred embodiment, a device for generating flow can be provided inside the envelope. The device for generating flow is designed to transport the thermal energy generated by the lamp arrangement through the flow generated in this way to the envelope which functions as a heat sink. Here, therefore, there is a generation of the heat flow through borrowed funds. The means for generating flow may be designed, for example, as a fan, fan or the like.

In a preferred embodiment, the gas pressure of the heat transfer medium in the interior of the shell is more than 1 bar, preferably more than 20 bar. In particular, the gas pressure of the heat transfer medium can be in a range between 0.1 bar to 10 bar and preferably in a range of 0.5 bar to 2 bar.

Preferably, the shell consists of a glass, ceramic or plastic body, which is completely transparent or at least partially transparent. Completely transparent in this context means that the envelope is translucent in the spectral wavelength range of light visible to humans and, if necessary, also in the UV range and in the infrared range. Alternatively, it would also be conceivable if the envelope is designed as a frosted glass body or contains such. Milk glass body refers to an opaque glass, which, although translucent, but at least partially opaque, whereby the glass looks white and cloudy. In this case, the milk glass can be produced by admixing a turbid substance or by subsequent roughening of the surface. As milk glass body are not only glassy body, but also milky plastic body to understand.

In a preferred embodiment, the envelope connected to the lamp base is gas-tight for the single gaseous heat transfer medium or single gas contained therein, so that the relatively large molecular weight elements of the heat transfer medium can not escape inside the envelope. Inside the envelope, therefore, no vacuum must be generated or a special gas can be introduced at low pressure. Rather, a specific, large-molecular gas is deliberately introduced into the interior of the shell. The higher the gas pressure inside the shell, the better it is because of the rising Convection resulting heat transport. This makes the production less expensive.

In a preferred embodiment, the luminous means arrangement comprises a multiplicity of optoelectronic components designed as LEDs. These optoelectronic components are provided within the envelope in a 4π arrangement in such a way to emit light in all spatial directions. The advantage is that this lamp according to the invention thus emits a light comparable to a conventional incandescent lamp in all spatial directions, so that there are therefore no shading areas or regions with lower light emission, which are generally perceived as unpleasant or less comfortable by a user.

In a preferred embodiment, the number and / or the type and / or the orientation of the LEDs used are provided such that the lamp emits white light during operation. Such a lamp according to the invention with corresponding LEDs can therefore appear in visual spectral range lights and to the human eye apparently or - depending on the type of mixture actually - generate white light. Such white light can be generated, for example, by means of a blue light emitting diode and a broadband luminescent dye, for example phosphorus, by mixing the blue light produced by the blue light emitting diode with the yellow light generated by the luminescent dye. In addition, white light can be produced by means of an ultraviolet light emitting diode and a luminescent dye for red, green and blue. The light colors generated by the three luminescent dyes red, green and blue become white light by suitable mixing. In addition, there are many other possibilities for generating white light by means of various LEDs.

In a further preferred refinement, the illuminant arrangement has red light, blue light, yellow light, violet light and / or green light-emitting light-emitting diodes. In addition, it would also be conceivable that the light emitting diodes emit infrared or ultraviolet light. By suitable mixing of the light emitted by these LEDs, a preferred desired coloration can be achieved.

In a preferred embodiment, at least a portion of the LEDs are arranged in series with each other. The LEDs are preferably connected in series in a so-called LED strip (LED strip). Preferably, a plurality of series circuits of LEDs arranged in series are provided. The switching in series of different LEDs is advantageous insofar as the corresponding lamp arrangement can be operated in this way with a higher supply voltage, which increases the efficiency. Also preferably, a plurality of LEDs arranged in series with each other are arranged parallel to each other. Several such series-connected LED arrays, which are connected in parallel with each other, can be operated with the same supply voltage and increase the luminous efficacy.

In a preferred embodiment, a Zener diode is connected in antiparallel to each LED and / or to a series connection of a plurality of LEDs. The antiparallel Zener diodes are designed to prevent that the possible failure of a single LED of a series circuit of LEDs leads to a complete malfunction of the entire lamp. In addition, safety is also increased in this way.

In an additional or alternative embodiment, the luminous means arrangement has a multiplicity of optoelectronic components designed as photosensitive sensors on. These sensors are provided within the envelope in a 4π arrangement such as to be light-sensitive in all spatial directions. The lamp according to the invention can thus also be used as a highly sensitive sensor which is sensitive in all spatial directions. In this case, the sensor can be used in particular as a light-sensitive sensor, in which case the optoelectronic components are designed as light-sensitive sensors.

In a preferred embodiment, the optoelectronic components are formed in strip strips with successively arranged and / or switched optoelectronic components. Such a strip of tape, which is sometimes also referred to as a "strip", is for example a solid or flexible semiconductor body in whose surface the corresponding semiconductor components are introduced. In addition, it would also be conceivable that individual semiconductor components are provided which are fastened to a strip-shaped material which forms the tape strip and are electrically connected to one another.

Advantageously, the tape strip is in a three-dimensional arrangement, e.g. bent in a spiral to ensure the appropriate 4π arrangement already by the curved structure can. The particular advantage here is that the various optoelectronic components do not have to be arranged and mounted in a complex manner in order to ensure the 4π arrangement, but that this already takes place to a certain extent automatically by a suitable bending of the tape strip. The production of such lamps according to the invention is thus significantly simplified.

In a further, likewise preferred embodiment, at least one strip-shaped semiconductor body is provided, the three-dimensionally shaped and formed and in which the optoelectronic components are introduced from several sides so that they act in all spatial directions. For example, a suitable cubic semiconductor body may be provided, in which optoelectronic components are introduced into all or at least some of the surfaces of the semiconductor body. By way of example, semiconductor components can be introduced both on the front side and on the back side of the semiconductor body, so that they emit in both sides. In the case of a cubic semiconductor body, theoretically the semiconductor devices could be incorporated in all six surfaces or at least in four circumferential surfaces.

In a further, likewise preferred embodiment, the lamp cap is designed as a socket with Edison thread. Preferably, one is provided as E40, E27, E14 and / or E10 socket. The base of a lamp is used to fix the lamp in a lamp socket and to contact electrically. The design of the lamp holder limits the permissible power and current consumption of the lamp operable therein. The dimensions of the so-called Edison thread are standardized in DIN 40400 and also in IEC 60238: 1998. The advantage of using the Edison thread is that the lamps according to the invention in conventional lamp holders, which were thus designed for conventional incandescent lamps, can be screwed so that users can continue to use their previous lights by the aforementioned EU incandescent lamp manufacturing and sales ban.

In a particularly preferred embodiment, the luminous means arrangement has a measuring circuit which measures the current through the luminous means arrangement and / or measures the voltage drop across the illuminant arrangement. Additionally or alternatively, a measurement of the LEDs generated temperature can be made. In this way, for example, a defective LED can be detected within the light assembly, which is indicated for example by a suitable display device. In addition, using these means would also be possible to detect overheating of the lamp and to take appropriate measures for cooling. Such measures could be, for example, switching off the lamp or dimming down the light output.

By means of the measuring circuit according to the invention, it is also possible, for example, to measure the aging of individual LEDs or the entire luminous means arrangement. In this case, the voltage drop across the lamp arrangement of individual or all light-emitting diodes is measured. From the measurement result is closed to the aging state of the lamp assembly. This measured, age-related voltage drop is a good indicator of the aging and thus the expected remaining life of the LED-based illuminant assembly. For example, the measured voltage could be compared with a reference value, and it could be determined from the comparison result whether the LED illuminant arrangement is reaching or threatening to reach its end of life. The measurement of this voltage drop, the comparison and the evaluation can be done automatically, for example, at regular intervals or, for example, each time the lamp is put into operation again. In this way, unnecessary and safety-related premature replacement of the lamp can be avoided, as well as too long operation with reduced luminosity, which may entail, for example, safety problems or at least a loss of comfort in the event of a failed lamp.

In a preferred embodiment, a drive circuit connected to the base is provided, which is designed to receive a supply voltage tapped off via the base to convert to a DC voltage and operate the lamp assembly with this DC voltage. In addition, it would also be conceivable to transform the supply voltage, for example the mains alternating voltage, down to such a low-voltage direct voltage, which is sufficient for operating the LEDs. Preferably, the driver circuit is disposed within the socket. Depending on the type of lamp, the respective type of converter can be selected with a view to achieving the best system performance. For example, if relatively long lamp modules, such as the L58W fluorescent lamp, are to be replaced, boost converters are preferred, while for example short lamps such as L18W Modules, used as a buck converter transducer (buck converter) can be used.

The above embodiments and developments can, if appropriate, combine with each other as desired. Further possible refinements, developments and implementations of the invention also include combinations, not explicitly mentioned, of features of the invention described above or below with regard to the exemplary embodiments. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.

CONTENT OF THE DRAWING

Fig. 1

eine Prinzipdarstellung einer erfindungsgemäßen Lampe;

Fig. 2

eine Prinzipdarstellung einer als Retrofit-Lampe ausgebildeten erfindungsgemäßen Lampe;

Fig. 3

ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Retrofit-Lampe;

Fig. 4

ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Retrofit-Lampe;

Fig. 5

einer Prinzipskizze für die Anordnung der LED-Streifen im Inneren der Hülle der Lampe;

Fig. 6

einer Prinzipskizze für eine weitere Anordnung der LED-Streifen im Inneren der Hülle der Lampe;

Fig. 7

anhand eines Ausführungsbeispiels den Aufbau eines LED-Streifens für eine erfindungsgemäße Lampe;

Fig. 8

ein weiteres Ausführungsbeispiel eines LED-Streifen;

Fig. 9

ein weiteres Ausführungsbeispiel eines LED-Streifen;

Fig. 10

ein Blockschaltbild zur Erläuterung der Verschaltung der Leuchtmittelanordnung.

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawings. It shows:

Fig. 1

a schematic diagram of a lamp according to the invention;

Fig. 2

a schematic diagram of a trained as a retrofit lamp lamp according to the invention;

Fig. 3

a further embodiment of a retrofit lamp according to the invention;

Fig. 4

a further embodiment of a retrofit lamp according to the invention;

Fig. 5

a schematic diagram of the arrangement of the LED strips inside the shell of the lamp;

Fig. 6

a schematic diagram of a further arrangement of the LED strips inside the envelope of the lamp;

Fig. 7

Based on an embodiment, the structure of an LED strip for a lamp according to the invention;

Fig. 8

another embodiment of an LED strip;

Fig. 9

another embodiment of an LED strip;

Fig. 10

a block diagram for explaining the interconnection of the lamp assembly.

The accompanying drawings are intended to provide further understanding of the embodiments of the invention. They illustrate embodiments and, together with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the stated advantages will become apparent with reference to the drawings. The elements of the drawings are not necessarily shown to scale to each other.

In the figures of the drawing are the same, functionally identical and same-acting elements, features and components - unless otherwise stated - each provided with the same reference numerals.

DESCRIPTION OF EMBODIMENTS

Fig. 1 shows a schematic diagram of the structure of a lamp according to the invention. The lamp is designated by reference numeral 10 and comprises a lamp base 11, a shell 12, a lighting arrangement 13 and a gaseous heat transfer medium 14.

The lamp base 11 denotes that part of the lamp 10 which produces the mechanical and electrical contact with a lamp or lamp socket. The lamp base 11 is connected to an at least partially transparent, closed shell 12, which is also referred to as a glass bulb or lamp envelope. This glass bulb 12 can optionally also partially mirrored inside, frosted (that is, roughened) or be made of opaque glass (frosted glass). Likewise, the glass bulb or lamp bulb can be made of plastic or ceramic in addition to glass. In this case, such a glass bulb or lamp envelope made of plastic or ceramic optionally optionally additionally at least partially coated, e.g. mirrored or matted, i. be roughened. Likewise, the glass bulb or lamp bulb can be made of an opaque plastic, which gives the glass or lamp envelope a milk glass effect.

The interior 15 of the glass bulb 12 is filled with a gas 14 or single gas, whose function will be explained below. In the interior 15 of the shell 12, a light-emitting device 13 is further provided, which a plurality of only here includes schematically illustrated optoelectronic devices 16. These optoelectronic components 16 are arranged within the glass bulb 12 in such a way that they act in all spatial directions (ie 4n). The optoelectronic components 16 may be designed, for example, as LEDs, light-sensitive sensors, laser diodes and the like.

The operation of the lamp 10 according to the invention will be explained below:

The provided inside 15 of the glass bulb 12 gas 14 is preferably formed as a large molecular gas. The gas is provided as a single gas in the glass bulb 12, in contrast to a gas mixture of a plurality of gases. Optionally, the gas may or may not have additional contamination by another gas or gases as a single gas or single filled gas. However, the contamination of the gas or individual gas in the glass bulb 12 is less than 0.5% in such a case.

A large-molecular gas is a gas whose molecules each have more than three atoms. For example, sulfur hexafluoride SF ₆ , carbon dioxide CO ₂ , as well as organic gases, including, for example, methane, ethane, propane, butane, pentane, hexane, etc. represent such large molecular gases, which can be provided as a single gas or gas in the glass bulb 12 or lamp envelope.

können im Temperaturbereich 273 K - ca. 1300 K (0-1000 °C) die Wärmekapazitäten von Gasen berechnet werden. Die Einheit [J/(mol K)] kann leicht durch Division durch die molare Masse [g/mol] in die technische Einheit [kJ/(kg K)] umgerechnet werden. Die Cp-Werte für 25 °C werden als Beispiele hiermit berechnet. Anzumerken ist, dass auch über der flüssigen Phase eines Stoffs eine messbare gasförmige Phase existiert. Temperaturabhängigkeit von Cp bei Gasen Material molare Masse in g/mol a b c d C_p (25°C) in J/(mol·K) Wasserstoff 2,016 29,09 - 0,8374 2,013 0,0000 29,0 Sauerstoff 32,00 27,96 4,180 - 0,1670 0,0000 29,2 Stickstoff 28,01 28,30 2,537 0,5443 0,0000 29,1 Kohlenmonoxid 28,01 27,63 5,024 0,0000 0,0000 29,1 Kohlendioxid 44,01 21,57 63,74 -40,53 9,684 37,2 Wasser (gas- förmig) 18,02 30,38 9,621 1,185 0,000 33,4 Methan 16,04 17,46 60,50 1,118 -7,210 35,4 Ethan 30,07 5,355 177,8 -68,75 8,520 52,5 n-Propan 44,10 -5,062 308,7 -161,9 33,33 73,5 n-Butan (gasförmig) 58,12 - 0,05024 387,3 -201,0 40,64 98,6 n-Pentan (gasförmig) 72,15 0,4145 480,6 -255,2 52,85 122 n-Hexan (gasförmig) 86,18 1,792 570,9 - 306,2 64,04 147 Such individual gases taken up in the glass bulb or lamp bulb have, as large-molecular gases or gases whose molecules each have more than three atoms, a high molar heat capacity C _P of Cp> 30J / (mol · K) at 25 ° C. As a result, these gases can absorb a larger amount of heat and the amount of heat to be dissipated better, as will be explained below. Temperature dependence of the "molar heat" C _p With the relationship $$C_p=a+b\cdot \left(T/1000\right)+c\cdot {\left(T/1000\right)}^2+d\cdot {\left(T/1000\right)}^3$$

In the temperature range 273 K - approx. 1300 K (0-1000 ° C) the heat capacities of gases can be calculated. The unit [J / (mol K)] can easily be converted into the technical unit [kJ / (kg K)] by dividing by the molar mass [g / mol]. The Cp values for 25 ° C are calculated as examples hereof. It should be noted that there is also a measurable gaseous phase above the liquid phase of a substance. Temperature dependence of Cp in gases material molar mass in g / mol a b c d C _p (25 ° C) in J / (mol · K) hydrogen 2,016 29,09 - 0.8374 2,013 0.0000 29.0 oxygen 32,00 27.96 4,180 - 0.1670 0.0000 29.2 nitrogen 28,01 28.30 2,537 .5443 0.0000 29.1 Carbon monoxide 28,01 27.63 5.024 0.0000 0.0000 29.1 carbon dioxide 44,01 21.57 63.74 -40.53 9,684 37.2 Water (gaseous) 18,02 30.38 9,621 1,185 0,000 33.4 methane 16.04 17.46 60,50 1,118 -7.210 35.4 Ethan 30.07 5,355 177.8 -68.75 8,520 52.5 n-propane 44,10 -5.062 308.7 -161.9 33.33 73.5 n-butane (gaseous) 58.12 - 0.05024 387.3 -201.0 40.64 98.6 n-pentane (gaseous) 72.15 .4145 480.6 -255.2 52.85 122 n-hexane (gaseous) 86.18 1,792 570.9 - 306.2 64.04 147

The thermal conductivity λ in W / (m · K) for an organic gas such as methane (at 20 ° C and 1 bar) λ = 0.0341 and for sulfur hexafluoride (at 0 ° C) λ = 0.012 as shown in the following table. Gaseous substances material Thermal conductivity λ in W / (m · K) hydrogen 0,186 helium .1567 argon 0.0179 krypton 0.00949 xenon 0.0055 Air (21% oxygen, 78% nitrogen) 0.0262 oxygen 0.0263 nitrogen 0.0260 Steam 0.0248 carbon dioxide 0.0168 Methane (20 ° C, 1 bar) .0341 Sulfur hexafluoride (0 ° C) 0,012 vacuum 0

The gas 14 and preferably also the material of the shell 12 have a very high heat absorption capacity.

During operation of the illuminant arrangement 13, for example, the optoelectronic components designed as LEDs heat up 16. The heat generated during operation of these LEDs 16 is inventively taken up by the designed as a heat transfer medium 14 large molecular gas 14 as a single gas and transported to the shell 12. The shell 12, which preferably has a high thermal conductivity, thus effectively acts as a heat sink and diverts the heat stored by the gas 14 to the outside. By means of the heat transfer medium 14 is thus carried by convection heat conduction to the shell 12, which is thus realized a very effective and nevertheless very simple cooling.

Large molecular gases 14 or gases 14, whose molecules each have more than three atoms, have the advantage over gases such as helium and hydrogen, that they can store a larger amount of heat and thus heat can be dissipated faster. Furthermore, the use of noble gases such as expensive helium can be dispensed with. In addition, no extra gas mixture must be produced, which simplifies the production and reduces costs. Instead, the shell 12 is filled only with a single large molecular gas or a large molecular weight single gas.

As described above, such large molecular single gases, inorganic gases such as e.g. Carbon dioxide, sulfur hexafluoride or organic gases such as e.g. Ethane, propane, butane, pentane, methane, etc.

The large-molecular gas accommodated in the casing 12 has, in particular, a pressure in a range from 0.1 bar to 10 bar and in particular a pressure in a range from 0.5 bar to 2 bar.

Fig. 2 shows a particularly preferred embodiment of the lamp 10 according to the invention. The lamp 10 is designed here as a so-called retrofit lamp 10, which thus a one conventional light bulb has comparable design. In contrast to a conventional incandescent lamp, in which a protective gas is provided to protect the filament inside the envelope 12, in the retrofit lamp according to the invention the bulb-like glass bulb functions together with the gas contained therein as a coolant. The gas is in Fig. 2 as well as the following figures, as previously with reference to Fig. 1 described as the only gas or single gas filled in the glass bulb, in contrast to a gas mixture, as in the cited in the introduction of the prior art. For the gas contained in the glass bulb as a gaseous heat transfer medium, the previously with reference to Fig. 1 made in order to avoid unnecessary repetition.

The base 11, which is connected to the shell 12, is formed in the present case as Edison lamp base. For example, an E27 socket for use for general-service lamps can be provided here.

Furthermore, a spirally formed illuminant arrangement 13 is provided here. This helical structure is suitable, analogous to a conventional filament, to emit light in all spatial directions, ie in the 4π direction. This spiral-shaped luminous arrangement 13 can be realized, for example, by a bendable wire, strip or semiconductor body, on whose surface corresponding LED components (in FIG Fig. 2 not shown) and are electrically connected to each other.

Fig. 3 shows a further embodiment of a retrofit lamp according to the invention designed as a lamp 10. The base 11 has an external contact 17 'and a foot contact 18'', via which an electrical supply voltage, typically a mains AC voltage is tapped, provided that the lamp 10 is screwed in a lamp socket.

In the interior of the base 11, respective electrical connection lines 20 are provided, which are electrically connected to a drive circuit 21, which is likewise provided in the interior of the base 10. This drive circuit 21 has a converter circuit 22 and a driver circuit 23. By means of the converter circuit 22, the AC line voltage is converted into a DC voltage for operating the LED-based lamp arrangement 13. In addition, typically the amplitude of the supply voltage is stepped down. Depending on the application, the driver circuit 23 may comprise a step-up converter or step-down converter, depending on which supply voltage is required for the lighting device arrangement 13.

Between the base 10 and the shell 12, a fastening device is also provided in the interior of the lamp 10, which serves for the mechanical fixing and fastening of the light bulb arrangement 13 provided in the interior 15 of the shell 12. In addition, this fastening device also functions to carry out corresponding supply lines 25 coming from the base 11 or the drive circuit 21 contained therein. These supply lines 25 connect the drive circuit 21 to the lighting arrangement 13. The fastening device 25 furthermore has an axial opening provided along the lamp axis 28 , cylindrical support device 26, which serves to support the bulb assembly 13 and which carries the bulb assembly 13.

The illuminant arrangement 13 has a plurality of LED strips 27. The LED strips 27 are essentially here arranged radially around the support device 26 around and spaced from each of the same distance. The LED strips 27 run in the embodiment in Fig. 3 substantially parallel to one another and substantially axially relative to the axis 28 of the lamp 10.

The LED strips 27 each include a plurality of LED devices arranged in series with each other as described below with reference to FIG Fig. 6 is still set forth. The LED strips 27 are connected on one side via the supply lines 25 with the fastening device and the driver circuit 23. On the other hand, the LED strips 27 are also connected to the drive circuit 21 via further supply lines 29 and the support device 26. For example, a positive supply potential VDD is applied to the supply line 29, and the supply lines 25 are supplied with a reference potential, for example the reference ground GND. Thus drops over each of the LED strips 27, the supply voltage VDD-GND.

Fig. 4 shows a further embodiment of a designed as a retrofit lamp lamp according to the invention 10. In contrast to the embodiment in Fig. 3 Here, the various LED strips 27 are arranged so that they move toward each other in the direction of the lamp axis 28 and the end face 30. These slanted positions of the LED strips 27 result in a better 3D illumination of the light, since in this way in particular the front side 30 of the shell 12 is not darkened, but also white light is emitted via the front side 30.

On the inner surface of the shell 12 is in the embodiment in Fig. 4 a coating 35 is provided. By way of example, this coating 35 is a suitable photoluminescent material, in order in this way to produce a desired light. For example, the LEDs 16 of the LED strips 27 may be blue light generating LEDs. In this case, it is advantageous to use a cerium doped yttrium aluminum garnet powder for the coating 35, which is a yellow phosphor. When the blue light of the blue LED 16 is combined with the yellow phosphor of the yttrium-aluminum garnet powder, white light is emitted, which is radiated from the lamp 10 to the outside.

The FIGS. 5 and 6 show on the basis of a schematic diagram two further embodiments, as the LED strips 27 may be disposed in the interior 15 of the shell 12 of the lamp 10.

In the embodiment in Fig. 5 four LED strips 27 are arranged so that they are each arranged on a side surface 31 of a virtual pyramid 32, which tapers towards the end face 30 of the shell 12.

In the embodiment in Fig. 6 are also four LED strips 27 are provided, which are each arranged on adjacent four surfaces 33 of a cuboid 34 (cuboid faces) so that a respective LED strip 27 forms a diagonal of the rectangular surface 33 of the cuboid 34, which is characterized by the LED Do not cut strip 27 running straight lines in the projection.

Fig. 7 shows on the basis of an embodiment, the structure of an LED strip 27 for a lamp according to the invention. The LED strip 27 comprises a substrate 40, which may be formed, for example, from glass, hard glass, quartz glass, ceramic, plastic or the like. The substrate 40 is preferably transparent.

On the substrate 40, a plurality of LED chips 41 is arranged. These LED chips 41 are introduced into the substrate 40, applied to its surface, fastened there, or arranged and secured in specially provided recesses in the substrate 40. The attachment of the LED chips 41 can be done for example by means of an adhesive layer, a bond, an adhesive or fastened connections or the like.

Each of these LED chips 41 comprises at least one LED semiconductor device. Each LED chip 41 is thus designed to emit light of a specific wavelength in accordance with the physical properties of the semiconductor material used and its doping.

The various LED chips 41 are arranged on the elongate substrate 40 in series with one another, that is to say successively. Respective adjacent LED chips 41 are electrically connected to each other via connecting lines 42. In this case, each LED chip 41 contains at least two contact terminals A, K, wherein one of these terminals forms the anode contact A and the other terminal forms the cathode contact K. The electrical contacting of adjacent LED chips 41 takes place in each case by means of bonding contacts by contacting a respective anode contact A of a first LED chip 41 with a cathode contact K of a further LED chip 41 adjacent to this LED chip 41.

The LED strip 27 has at its two opposite ends in each case a contact terminal (lead) 43, 44 which are each connected to the outermost LED chips 41 of the LED strip 27 via a connecting line 42. For fixing these contact terminals 43, 44, a fixing device 45 is provided.

Additionally (in Fig. 7 not shown), a transparent outer sheath-shaped tube may be provided to protect the LED strip 27 and the individual LED chips 41 on the substrate 40.

In Fig. 7 Let it be assumed that all the LED components on the LED chips 41 are identical and thus emit a light of the same wavelength. It would also be conceivable, however, for different light-emitting LED chips 41 to be present, for example yellow light and blue light-emitting LEDs, whereby white light is emitted when the generated light beams are mixed. In the same way, of course, any other combinations of different light-emitting LEDs would be possible.

Alternatively, it would also be conceivable that the substrate 40 is a semiconductor substrate. In this case, the LED chips 41 could be introduced directly into the semiconductor body 40 of the substrate 40, for example by diffusion and implantation. This is particularly advantageous from a manufacturing point of view, but for the otherwise brittle semiconductor body of the substrate 40, e.g. an additional carrier is required, which would need to stabilize the substrate 40. Alternatively, it would also be conceivable that the substrate 40 designed as a semiconductor body is made so thin that it is flexible and is fastened, for example, on a flexible film.

Fig. 8 shows a further embodiment of an LED strip 27. This LED strip 27 has a cubic shape and thus comprises various rectangular surfaces 50. On at least two of these Rocheckförmigen surfaces 50 corresponding LED chips 41 are attached or, for example in the case of a semiconductor body 40 formed LED strip 27, embedded directly in the semiconductor body 40. The different LED chips 41 or LED components 16 are preferably arranged at least on two opposite rectangular surfaces 50 of the semiconductor body 40. Thus, after the various LEDs 16 or LED chips 41 have been arranged or introduced on different surfaces 50 of the semiconductor body 40, the cubic structure of the substrate 40 already radiates the light emitted by the various LEDs 16 into different spatial directions.

Fig. 9 shows a further embodiment of an LED strip 27 for a lamp 10 according to the invention. Here, the substrate 40 of the LED strip 27 is already in a curved shape, so that at least one non-planar, curved surface 51 is present. On this non-planar surface 51, the corresponding LED chips 41 and LED components 16 are arranged or introduced. Due to the curved structure of the LED strip 27, there is thus likewise a radiation of the light emitted by the various LEDs 16 in different spatial directions.

Fig. 10 shows a block diagram for a further embodiment of an LED strip according to the invention 27. The first contact terminal 43 is in operation with a first supply potential V1 and the second contact terminal 44 is acted upon in operation with a second supply potential V2. Between these contact terminals 43, 44, a series circuit of four LEDs 52 is connected. It is assumed that in the present case all LEDs 52 are identical. Antiparallel to each of these LEDs 52, a Zener diode 53 is connected in each case. These anti-parallel Zener diodes 53 serve the purpose of maintaining the operation of the LED series circuit with the remaining, functional LEDs in case of failure of an LED 52. Otherwise would in the event of failure of a single serially connected LED 52, the entire LED series circuit will be inoperable.

Furthermore, a measuring circuit 54 is provided. This measurement circuit 54 serves the purpose of determining the current, the voltage, the temperature and / or possibly further parameters of the LED strip 27. For example, the measurement of the current by means of a resistance element, which is arranged in series with the LEDs 52. The measurement of the voltage, for example, by means of a parallel resistor. In addition, the temperature can be derived from the determined current.

Although the present invention has been fully described above with reference to preferred embodiments, it is not limited thereto but is modifiable in a variety of ways.

In particular, the present invention is not limited to retrofit lamps with Edison socket. For example, another type of socket, such as a socket, bayonet socket, two-pin socket, and the like, may be used. Basically, so-called socketless lamps would be conceivable in which the base is realized via contact wires.

The shape of the shell is not limited to a pear-shaped incandescent-like design, but may be of any design, provided that it does not deviate from the core idea of the invention. For example, the invention is also applicable to a krypton lamp, a halogen-type lamp and the like. The lamp has, as previously with reference to Fig. 1 described, a single filling gas, wherein the molecules of the filling gas each have at least three atoms. This applies to all embodiments of the invention.

LIST OF REFERENCE NUMBERS

10

lamp

11

(Lamp) Base

12

Shell, glass bulb

13

Lamp positioning

14

Gas, heat transfer medium

15

Inner / interior of the shell

16

optoelectronic component, LED

17

outside Contact

18

foot contact

20

electrical connection lines

21

drive circuit

22

converter circuit

23

driver circuit

25

supply lines

26

support device

27

LED strip

28

Lamp axis

29

supply lines

30

front

31

side surface

32

pyramid

33

rectangular surface

34

cuboid

35

coating

40

Substrate, semiconductor body

41

LED chip

42

connecting line

43

first contact connection

44

second contact connection

45

fixing

50

rectangular surface

51

curved, non-level surface

52

LED component

53

Zener diode

54

measuring circuit

A

anode

K

cathode

GND

Reference potential, potential of reference ground

V1, V2

supply potential

Vdd

positive supply potential

Claims (15)

Lamp, in particular retrofit lamp,
with a lamp base,
with an at least partially transparent closed sheath, which is connected to the lamp base and which is designed to act as a heat sink for the lamp,
with a luminous means arrangement which contains a plurality of optoelectronic components which are arranged within the envelope in such a 4π arrangement that they act in all spatial directions,
with a gaseous heat transfer medium, which is introduced in the interior of the shell and which is adapted to transport generated by the lamp arrangement thermal energy to the acting as a heat sink envelope, wherein the gaseous heat transfer medium is provided as the only gas in the shell and the molecules of the gaseous Heat transfer medium each having at least three atoms. Lamp according to claim 1,
characterized,
that the heat transfer medium having a relatively large heat capacity, in particular, molar heat capacity, wherein the molar heat capacity greater than 30J / (mol * K). Lamp according to one of the preceding claims,
characterized,
that the heat transfer medium, a gaseous inorganic compound, in particular carbon dioxide or Sulfurhexafluorid, or an organic gaseous compound, in particular methane, ethane, propane, butane or pentane. Lamp according to one of the preceding claims,
characterized,
that the thermal energy generated by the lamp arrangement is transported by convection to the heat sink acting as sheath. Lamp according to one of the preceding claims,
characterized,
in that a device for generating flow, in particular a blower or a ventilator, is provided inside the envelope, which is designed to transport the thermal energy generated by the illuminant arrangement through the flow thus generated to the envelope functioning as a cooling body, the envelope preferably is formed of a completely transparent material or contains a partially transparent milk glass body. Lamp according to one of the preceding claims,
characterized,
that the gas pressure of the heat transfer medium inside the envelope is greater than 1 bar, preferably greater than 20 bar, and the gas pressure of the heat transfer medium is more preferably in a range between 0.1 bar and 10 bar and more particularly in a range of 0.5 bar to 2 bar. Lamp according to one of the preceding claims,
characterized,
that the lighting means arrangement comprises a plurality of LEDs formed as optoelectronic devices, which are provided within the shell in a 4π arrangement so as to emit light in all directions in space. Lamp according to one of the preceding claims,
characterized,
that the number and / or the type and / or the orientation of the LEDs used is such that the lamp emits white light during operation and preferably the lamp base as a socket with Edison thread, in particular as E40, E27, E14, E10 -Socket, is formed. Lamp according to one of the preceding claims,
characterized,
in that at least some of the LEDs are arranged in series with one another, wherein in particular a plurality of LEDs arranged in series are arranged parallel to one another and wherein at least one zener diode is connected in antiparallel to each LED and / or to a series connection of a plurality of LEDs. Lamp according to one of the preceding claims,
characterized,
that the luminous means arrangement has a large number of optoelectronic components designed as photosensitive sensors, which are provided within the envelope in a 4π arrangement in such a way as to be light-sensitive in all spatial directions. Lamp according to one of the preceding claims,
characterized,
in that the optoelectronic components are arranged in strip strips with successively arranged and / or switched components, wherein the strip strip is bent in particular in a 3D arrangement. Lamp according to one of the preceding claims,
characterized,
that at least one strip-shaped semiconductor body is provided which is 3D-shaped in such a way and in which the optoelectronic components are introduced from all sides in such a way that they act in all spatial directions. Lamp according to one of the preceding claims,
characterized,
that the luminous means arrangement has a measuring circuit which measures the current through the luminous means arrangement and / or which measures the voltage dropping at the illuminant arrangement and / or which measures the temperature generated by the LEDs. Lamp according to one of the preceding claims,
characterized,
in that a converter circuit connected to the base is provided, which is designed to convert a supply voltage tapped off via the base to a DC voltage. Lamp according to one of the preceding claims,
characterized,
that a driver circuit is provided, which is designed to drive the lamp arrangement with a DC voltage.

Images