JP2011044360A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To install a power supply circuit for supplying electric power to a surface light emitting element so as to be manufactured with a small area at low cost, in a light emitting device having a surface light emitting element. <P>SOLUTION: The light emitting device 1 includes: the surface light emitting element 4 having a light emitting layer 43 and electrodes 41, 46 sandwiching the light emitting layer; a transparent substrate 5 on which the surface light emitting element 4 is placed; and a sealing member 6 which seals the surface light emitting element 4. The light emitting device 1 further includes the power supply circuit 9 and a wiring pattern 10 which supply electric power to the surface light emitting element 4, and the power supply circuit 9 and the wiring pattern 10 are formed on part of the sealing member 6. As a result, part of the sealing member 6 is also used for forming the power supply circuit 9, and the power supply circuit 9 is manufactured with the small area at low cost. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device having a planar light emitting element.

  2. Description of the Related Art Conventionally, EL (electroluminescence) light-emitting elements are known as planar light-emitting elements that are planar light sources, and particularly organic EL light-emitting elements have been developed. In the organic EL light emitting device, an organic thin film containing an organic compound is sandwiched between an anode and a cathode. Then, electrons from the cathode and holes (holes) from the anode are injected into the organic thin film, and the injected electrons and holes are combined in the light emitting layer of the organic thin film, and the exciton in which the electronic state of the organic compound is in an excited state. Light emitted when the exciton is returned to the ground state is extracted outside the organic EL light emitting element. Since the organic EL light emitting element emits light when supplied with a direct current voltage, a power supply circuit for converting an alternating commercial power source into direct current is necessary.

  The luminaires have different required specifications such as light output (light flux) and shape of the light emitting part depending on the usage and application. When many types of organic EL light-emitting elements incorporated in a lighting fixture are designed and produced in accordance with many required specifications for the lighting fixture, design labor and production cost become excessive. Therefore, it is conceivable that the lighting fixture is adapted to the required specifications by combining a versatile organic EL light emitting element and incorporating it into the lighting fixture. In this case, since the specifications of the power source for supplying power to the organic EL light-emitting elements are different depending on the number of organic EL light-emitting elements to be combined and the connection state, it is difficult to share power sources in different lighting fixtures. For this reason, it is conceivable to individually provide a power source for each organic EL light emitting element.

  An individual power source for each organic EL light emitting element is required to be thin in order to be juxtaposed with a thin organic EL light emitting element. Also, the electrical connection between the power source and the organic EL light emitting element is required to be thin. For this reason, for example, a power supply is created using a printed circuit board, and this power supply and an organic EL light emitting element are connected by FPC (flexible printed circuit board).

  However, a lighting fixture in which an organic EL light emitting element and a power source are arranged side by side has a large area of a power source that is a non-light-emitting portion, so that it does not look good, and the size (area) of the lighting fixture increases. In addition, since the power source and the organic EL light emitting element are separate bodies, stress is generated at the connection portion between them, and it is difficult to ensure reliability to withstand the stress. In order to suppress the generation of stress, a structure in which the power source and the organic EL light emitting element are fixed to each other is conceivable. However, the fixing structure increases the cost of the lighting fixture, and the size of the fixing structure increases the size of the lighting fixture.

  In addition, a configuration in which a power source is provided on the back surface of the organic EL light emitting element and the organic EL light emitting elements are connected by FPC is known (for example, see Patent Document 1). The luminaire can be made smaller than when power supplies are juxtaposed. However, since the lighting fixture of this connection form requires a component for fixing the power source on the back surface of the organic EL light emitting element, the number of components increases and the cost increases.

JP 2006-323144 A

  An object of the present invention is to solve the above-described problem, and an object of the present invention is to provide a power supply circuit for supplying power to a planar light emitting element in a light emitting device having a planar light emitting element so as to reduce the area and cost.

  In order to achieve the above object, the invention of claim 1 includes a planar light emitting device having a light emitting layer and an electrode sandwiching the light emitting layer, a transparent substrate on which the planar light emitting device is mounted, and the surface. A sealing member for sealing the planar light emitting element, further comprising a power supply circuit and a wiring pattern for supplying power to the planar light emitting element, wherein the power supply circuit and the wiring pattern are provided on the sealing member. It is implemented in part.

  According to a second aspect of the present invention, in the light emitting device according to the first aspect, the sealing member includes a portion extending from a peripheral edge of the transparent substrate, and supplies power to the power supply circuit from the outside of the light emitting device. The terminal part to receive is provided in the said extension part.

  According to a third aspect of the present invention, in the light emitting device according to the first or second aspect, the sealing member is provided on an insulating material and the insulating material, and the temperature distribution of the planar light emitting element is made uniform. The power supply circuit and the wiring pattern are mounted on the insulating material.

  According to the first aspect of the present invention, since a part of the sealing member for sealing the planar light emitting element is also used for mounting the power supply circuit, the power supply circuit can be configured integrally with the planar light emitting element. Therefore, the area is reduced, and a separate member for fixing the power supply circuit is not required, and the cost is reduced.

  According to the second aspect of the present invention, the terminal portion provided in the extended portion of the sealing member is also used for receiving power supply and fixing the light emitting device, so that the portion that does not emit light (non-lighting) The area of the light emitting part) can be reduced. Further, when a lighting fixture is configured by arranging a plurality of light emitting devices, the area of the non-light emitting portion of the lighting fixture can be reduced by superimposing the terminal portions serving as the non-light emitting portions.

  According to the invention of claim 3, since the temperature distribution of the planar light emitting element is made uniform by the metal material, the light emission unevenness due to the temperature difference is suppressed. In addition, the power supply circuit and the wiring pattern are insulated from the metal material by the insulating material, and the power supply circuit dissipates heat by conduction of heat generated in the metal material, so that the temperature rise can be suppressed.

The perspective view of the lighting fixture which has a light-emitting device which concerns on the 1st Embodiment of this invention. The exploded perspective view of the lighting fixture. The top view which looked at the light-emitting device of the lighting fixture from the opposite side to the side from which light is taken out. AA line sectional view of Drawing 3. The top view of the lighting fixture. BB sectional drawing of FIG. The perspective view of the lighting fixture which concerns on the 2nd Embodiment of this invention. The exploded perspective view of the lighting fixture. The top view of the lighting fixture. CC sectional view taken on the line of FIG. Sectional drawing of the light-emitting device which concerns on the 3rd Embodiment of this invention. Sectional drawing of the light-emitting device which concerns on the 4th Embodiment of this invention. Sectional drawing of the light-emitting device which concerns on the 5th Embodiment of this invention. Sectional drawing of the light-emitting device which concerns on the 6th Embodiment of this invention.

(First embodiment)
A lighting fixture having a light emitting device according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a lighting fixture 2 is configured by a planar light emitting device 1, a plate-like lighting fixture body 21 to which the light emitting device 1 is fixed, and a mounting bracket 3. Illumination light from the luminaire 2 is irradiated upward in FIG. The light emitting device 1 has a substantially rectangular shape in a plan view of about several tens mm (millimeters) to several hundred mm square, for example. The lighting fixture 2 is installed on a wall surface, a ceiling, or the like. As shown in FIG. 2, the light emitting device 1 has a terminal portion 11 fixed to the luminaire main body 21 by a hook-shaped mounting bracket 3.

  As shown in FIGS. 3 and 4, the light emitting device 1 includes a planar light emitting element 4 (hereinafter referred to as a light emitting element), a transparent substrate 5 on which the light emitting element 4 is placed, and a seal that seals the light emitting element 4. A stop member 6, a protective film 7, a hygroscopic agent 8, and a power supply circuit 9 and a wiring pattern 10 for supplying power to the light emitting element 4 are provided. The power supply circuit 9 and the wiring pattern 10 are mounted on a part of the sealing member 6. Light emitted from the light emitting element 4 is extracted as illumination light downward in FIG.

  The light emitting element 4 is an organic EL element, and is formed on the transparent substrate 5 in the order of an anode 41, a hole transport layer 42, a light emitting layer 43, an electron transport layer 44, an electron injection layer 45, and a cathode 46. The hole transport layer 42, the light emitting layer 43, the electron transport layer 44, and the electron injection layer 45 are organic thin films having a total thickness of about 100 to 200 nm (nanometers) formed by, for example, vacuum deposition or the like. Enlarged in the direction. This organic thin film is sandwiched between an anode 41 and a cathode 46 which are electrodes.

The material of each layer of the light emitting element 4 is, for example, that the anode 41 is ITO (indium tin oxide), the hole transport layer 42 is arylamines, the light emitting layer 43 is aluminum complex (Alq ₃ ), and the electron transport layer 44 is oxodioxide. In the case of azoles, the electron injection layer 45 is a lithium complex, and the cathode 46 is aluminum. The hole transport layer 42, the electron transport layer 44, and the electron injection layer 45 improve the light emission efficiency of the light emitting layer 43. A part of the cathode 46 is formed on the transparent substrate 5 in order to provide a part connected to the power supply circuit 9. The anode 41 and the cathode 46 on the transparent substrate 5 are insulated from each other by an insulating layer 48. An auxiliary electrode 411 is provided on a part of the surface of the anode 41. The auxiliary electrode 411 has a low resistance and makes the potential of the anode 41 uniform.

  The light emitting layer 43 passes through the transparent anode 41 and the transparent substrate 5 and outputs light into the atmosphere. The transparent substrate 5 is made of glass, and a light extraction film 51 is attached to a surface on the light extraction side. The light extraction film 51 is a resin film having fine irregularities on its surface, a resin film containing a fine particle light diffusing agent, or the like, and suppresses total reflection at the interface with the atmosphere to increase light extraction efficiency. The cathode 46 reflects light emitted from the light emitting layer 43 to the transparent substrate 5 side, and improves light extraction efficiency.

  The sealing member 6 includes an insulating base 61 and a sealing material 62 and hermetically seals the light emitting element 4 and the power supply circuit 9. The insulating base 61 is made of a thin film-like insulating material having flexibility, and is, for example, a polyimide film. The polyimide film has a thickness of 0. 0 which is generally used for FPC and the like. It is an insulating material of about several mm. The sealing material 62 is made of, for example, an epoxy resin and can be freely formed in shape. By using a polyimide film or the like having low air permeability and moisture permeability for the insulating base 61, the sealing material 62 can be used mainly for the peripheral portion of the insulating base 61 to reduce the amount of use.

  The insulating base 61 includes a portion extending from the peripheral edge of the transparent substrate 5, and the terminal portion 11 is provided in the extending portion. In the present embodiment, the terminal portion 11 is provided at a portion extending from the four corners of the periphery of the light emitting device 1. The terminal unit 11 is supplied with power from the outside of the light emitting device 1 and is connected to the power supply circuit 9 by the wiring pattern 10. The power supply circuit 9 is electrically connected to at least two terminal portions 11 among the plurality of terminal portions 11. In order to improve the connection reliability, all the terminal portions 11 may be connected to the power supply circuit 9.

  The protective film 7 is formed on the cathode 46, the hygroscopic agent 8 is provided on the protective film 7, and the sealing member 6 is provided on the hygroscopic agent 8. The sealing material 62 and the hygroscopic agent 8 are bonded by an adhesive 63 such as an epoxy resin. The hygroscopic agent 8 is made of calcium oxide (CaO), barium oxide (BaO), or the like, and is disposed in a portion that is kept airtight by the sealing member 6, and prevents deterioration of the light emitting element 4 due to moisture. The protective film 7 is made of an organic compound or the like, and protects the cathode 46 from the hygroscopic agent 8.

  The power supply circuit 9 is an AC / DC circuit or a DC / DC circuit, and at least a part thereof is mounted on the insulating base 61. The DC output of the power supply circuit 9 is input from the power supply input unit 47 to the light emitting element 4. The insulating substrate 61 may not be a polyimide film as long as it has appropriate characteristics and can be mounted on at least a part of the power supply circuit 9.

  The wiring pattern 10 is a conductive pattern made of copper foil or the like, and is formed on the insulating substrate 61. The power supply circuit 9 has a power supply circuit element 91. The power circuit element 91 is wired by a part of the wiring pattern 10.

  The power supply input unit 47 is provided on the electrodes 41 and 46 of the light emitting element 4, and is connected to the output side of the power supply circuit 9 through the electrical connection unit 92. The electrical connection portion 92 is an aluminum wire or the like, is connected by ultrasonic bonding, and is protected by the sealing material 62.

  In the light emitting device 1 configured as described above, since the insulating base 61 that is a part of the sealing member 6 that seals the light emitting element 4 is also used for mounting the power supply circuit 9, the power supply circuit 9 is used as the light emitting element. 4, so that the area is small, and a separate member for fixing the power supply circuit 9 is not required, resulting in a low cost.

  As shown in FIGS. 5 and 6, the terminal portion 11 is fixed to the luminaire main body 21 by the mounting bracket 3. The mounting bracket 3 serves as both a mounting member and a conductive member, and is formed of a metal in a bowl shape. The mounting bracket 3 has a head portion 31 and a shaft portion 32 as a flange, and a spring washer on the lower surface side of the head portion 31. A contact member 34 made of copper or the like for reducing contact resistance is provided on a partial surface of the shaft portion 32.

  The terminal portion 11 is formed on the insulating base 61 provided with an insertion hole 64 for inserting the shaft portion 32 of the mounting bracket 3, the wiring pattern 10 provided on both surfaces of the insulating base 61, and the insulating base 61. And vias 12 extending therethrough. The via 12 conducts the wiring pattern 10 provided on both surfaces of the insulating base 61.

  The luminaire main body 21 has a hole 22 at a position corresponding to the insertion hole 64 of the insulating base 61 and an electric wire 23 inside. The electric wire 23 is provided in order to supply electric power to the light-emitting device 1 from an external commercial power source. A power source for stepping down the commercial power source may be provided in the luminaire main body 21, and power may be supplied from the power source via the electric wire 23. An end portion of the electric wire 23 is connected to a feeding contact portion 24 provided on the inner wall of the hole portion 22. The feeding contact portion 24 is a leaf spring-shaped metal member.

  Then, the shaft portion 32 of the mounting bracket 3 is inserted into the insertion hole 64 of the insulating base material 61 and fitted into the hole portion 22 of the lighting fixture main body 21. The terminal portion 11 is pressed against the surface of the luminaire main body 21 by the head 31 of the mounting bracket 3 and fixed. The current path from the luminaire main body 21 to the light emitting device 1 includes the electric wire 23, the power supply contact portion 24, the contact member 34, the shaft portion 32, the head portion 31, the spring washer 33, and the wiring pattern 10, as indicated by broken line arrows. Become. Power is supplied to the power supply circuit 9 of the light emitting device 1 through this current path.

  As described above, the light emitting device 1 does not emit light by using the terminal portion 11 provided in the extended portion of the insulating base 61 for receiving power supply and fixing the light emitting device 1. The area of the portion can be reduced. Moreover, the lighting fixture 2 which has the light-emitting device 1 is easily changed into the fixture with a different light output, without replacing the lighting fixture main body 21, by replacing the light-emitting device 1 with one having a different light output.

(Second Embodiment)
A lighting apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The same code | symbol is attached | subjected to the location equivalent to 1st Embodiment. As shown in FIG. 7, the lighting fixture 102 of the present embodiment includes a light emitting device 1 having the same configuration as that of the first embodiment, and a single lighting fixture main body 121 that fixes and arranges a plurality of the light emitting devices 1. Have. The number of light-emitting devices 1 arranged in the lighting fixture 102 is determined based on the required specifications for the lighting fixture 102. As shown in FIG. 8, the light emitting devices 1 that are adjacent to each other are fixed to the luminaire main body 121 by the mounting bracket 3 with the respective terminal portions 11 overlapped. Here, the upper and lower order of overlapping the terminal portions 11 is not limited.

  As shown in FIG. 9, a plurality of light emitting devices 1 are attached to a luminaire main body 121 to constitute a luminaire 102. Since the terminal part 11 is comprised using the thin film-like insulating base material 61 which has a softness | flexibility, as FIG. 10 shows, the several terminal part 11 is easily overlaid. The shaft portion 32 of the mounting bracket 3 is inserted into the insertion holes 64 of the plurality of terminal portions 11 and fitted into the hole portions 22 of the lighting fixture main body 121. The overlapped terminal portion 11 is pressed and fixed to the surface of the lighting fixture main body 121 by the head 31 of the mounting bracket 3. As in the first embodiment, power is supplied from the lighting fixture main body 121 to the power supply circuit 9 of the light emitting device 1.

  Thus, when the lighting fixture 102 is configured by arranging a plurality of light emitting devices 1, the area of the non-light emitting portion of the lighting fixture 102 can be reduced by overlapping the terminal portions 11 serving as the non-light emitting portions. . In addition, by overlapping the terminal portions 11, the plurality of light emitting devices 1 can be arranged with a small gap therebetween.

(Third embodiment)
A light emitting device according to a third embodiment of the present invention will be described with reference to FIG. The light emitting device 103 of the present embodiment has the same configuration as that of the light emitting device 1 of the first embodiment, and instead of the electrical connection portion made of aluminum wire or the like, a part of the insulating base 61 is curved, By connecting the wiring pattern 10 on the insulating base 61 to the power input unit 47, power is supplied from the power circuit 9 to the light emitting element 4. Since the insulating base 61 is a film having flexibility, a curved configuration is possible. For connection of the wiring pattern 10 in the power input unit 47, for example, ACF (anisotropic conductive film) connection or the like is used. With this configuration, the light emitting device 103 according to the present embodiment is reduced in the number of parts for connecting the power supply circuit 9 and the light emitting element 4, thereby reducing costs.

(Fourth embodiment)
A light emitting device according to a fourth embodiment of the present invention will be described with reference to FIG. The light emitting device 104 of the present embodiment has a metal substrate 66 made of a planar metal material on an insulating substrate 61 in addition to the same configuration as that of the light emitting device 1 of the first embodiment. The metal base 66 is, for example, plate-like aluminum, a so-called aluminum substrate, and is disposed so as to face the light emitting element 4 through the insulating base 61 or the like in order to make the temperature distribution of the light emitting element 4 uniform. . The power supply circuit 9 and the wiring pattern 10 are mounted on an insulating base 61 made of an insulating material. The power supply circuit 9 is close to the metal base 66 through the insulating base 61 and the like.

  When the metal substrate 66 is not provided, if the light emitting element has a large element area, a difference in temperature distribution occurs due to heat generation during light emission, and light emission unevenness occurs due to the temperature difference. In the present embodiment, the heat generated by the light emitting element 4 is conducted to the metal substrate 66. Since the metal base material 66 made of a metal material has high thermal conductivity, the temperature distribution is substantially uniform. Since the temperature distribution of the light emitting element 4 is made uniform by the metal base material 66, unevenness in light emission due to a temperature difference is suppressed. In addition, the light-emitting device 104 increases the sealing effect of the light-emitting element 4 by the metal base material 66, and the strength is improved by the mechanical strength of the metal base material 66. Moreover, since the heat generated in the power supply circuit 9 is conducted to the metal substrate 66 and radiated, the temperature rise can be suppressed.

(Fifth embodiment)
A light emitting device according to a fifth embodiment of the present invention will be described with reference to FIG. The light emitting device 105 of the present embodiment has the same configuration as the light emitting device 1 of the first embodiment, and faces the light emitting element 4 of the insulating base 61 instead of forming a cathode on the light emitting element 4. A metal pattern 67 is formed on the surface. The metal pattern 67 is made of a metal having high conductivity and high reflectivity, such as aluminum, copper, silver, and the like. The metal pattern 67 is in contact with the organic layer of the light emitting element 4 to supply power and reflects light emitted from the light emitting layer 43. . With such a configuration, the cathode of the light emitting element 4 is not formed, so that the cost of the light emitting device 105 is reduced.

(Sixth embodiment)
A light emitting device according to a sixth embodiment of the present invention will be described with reference to FIG. The light emitting device 106 of the present embodiment has the same configuration as that of the light emitting device 1 of the first embodiment, and all the power supply circuit elements 91 of the power supply circuit 9 mounted on the insulating substrate 61 are contained in the sealing material 62. In place of the arrangement, a part of the power supply circuit element 91 a is arranged outside the sealing material 62 in the vicinity of the outer periphery of the light emitting device 106. The power supply circuit element 91a disposed outside the sealing material 62 is an element that generates a large amount of heat among the power supply circuit elements 91 of the power supply circuit 9, and is, for example, a switching element or an inductance element. Other power supply circuit elements 91 b are sealed with a sealing material 62. The insulating base 61 is provided with a spacer 13 for keeping a distance from the transparent substrate 5.

  As described above, since the power supply circuit element 91a that generates a large amount of heat is disposed outside the sealing material 62, heat dissipation is improved. For this reason, the temperature rise of the light emitting element 4 due to the heat generation of the power supply circuit element 91a is prevented, and the occurrence of uneven light emission of the light emitting element 4 is prevented. The power supply circuit element 91a is desirably disposed near the terminal portion 11 in the vicinity of the outer periphery of the light emitting device 106. With such an arrangement, in addition to heat radiation to the atmosphere, heat to the luminaire main body via the terminal portion 11 is provided. Heat dissipation is promoted by conduction.

  In addition, this invention is not restricted to the structure of said embodiment, A various deformation | transformation is possible in the range which does not change the summary of invention. For example, you may comprise the lighting fixture 102 of 2nd Embodiment using the light emitting element in any one of 3rd thru | or 6th Embodiment. Moreover, in 1st or 2nd embodiment, the attachment metal fitting 3 is made into a bolt shape, a female screw is formed in a part of the inner wall of the hole part 22 of the lighting fixture body 21, and the attachment metal fitting 3 is screwed into the hole part 22. You may comprise as follows. Further, instead of the mounting bracket 3, a resin mounting jig having substantially the same shape may be used. In that case, the spring washer 33 and the shaft contact member 34 are electrically connected by a conductive wire or the like.

1, 103, 104, 105, 106 Light-emitting device 2, 102 Lighting fixture 4 Planar light-emitting element 41 Anode (electrode)
43 Light emitting layer 46 Cathode (electrode)
5 Transparent substrate 6 Sealing member 61 Insulating base material (insulating material)
66 Metal substrate (metal material)
9 Power supply circuit 10 Wiring pattern 11 Terminal

Claims (3)

A planar light emitting device having a light emitting layer and an electrode sandwiching the light emitting layer;
A transparent substrate on which the planar light emitting element is placed;
A light-emitting device comprising a sealing member for sealing the planar light-emitting element,
A power circuit for supplying power to the planar light emitting device and a wiring pattern;
The light emitting device, wherein the power supply circuit and the wiring pattern are mounted on a part of the sealing member. The sealing member includes a portion extending from a peripheral edge of the transparent substrate,
The light emitting device according to claim 1, wherein a terminal portion that receives power from the outside of the light emitting device is provided in the extending portion. The sealing member includes an insulating material, and a planar metal material provided on the insulating material for uniforming the temperature distribution of the planar light emitting element,
The light emitting device according to claim 1, wherein the power supply circuit and the wiring pattern are mounted on the insulating material.

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