Light-emitting device

Abstract

To provide a small light-emitting device, and a light-emitting device that hardly generates shades.SOLUTION: The light-emitting device comprises a switching circuit for supplying pulsed constant current and a light-emitting panel to which the pulsed constant current is supplied.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an article, a method, or a manufacturing method. , manufacture, or composition of matter. The present invention relates to, for example, a semiconductor device, a display device, a light-emitting device, a power storage device, and a driving method thereof. In particular, the present invention relates to a light emitting device. [Background technology]

[0002] Using organic electroluminescence (EL) Research and development of light-emitting elements (also called organic EL elements) that use light emitted from a light source is being actively carried out. The basic structure of the device is a layer containing a light-emitting organic compound (also called an EL layer) sandwiched between a pair of electrodes. By applying a voltage to this element, light is emitted from the light-emitting organic compound. can be obtained.

[0003] Since organic EL elements can be formed into a film, it is easy to form large-area elements. It is also highly useful as a surface light source for lighting and other applications.

[0004] For example, Patent Document 1 discloses a lighting fixture using an organic EL element. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-130132 A Summary of the Invention [Problem to be solved by the invention]

[0006] The camera is equipped with a flash so that photos can be taken in dark places.

[0007] In addition, there is a demand for cameras to be smaller and / or lighter so that they can be easily carried around. It is being done.

[0008] However, if the flash is made smaller, the light emission area becomes more linear or dot-like, which can cause the following problems: becomes apparent.

[0009] Because light travels in a straight line from its source, the shadow cast by an object will be clearer the smaller the source.

[0010] This means that, for example, when a person's face is photographed in a dark place using a flash, the shadow of the nose will be on the cheek. It may be projected.

[0011] One aspect of the present invention has been made against this technical background. It is an object of the present invention to provide a light-emitting device having a light-emitting function that is less likely to cause shadows. One of the goals of the project is to

[0012] The description of these problems does not preclude the existence of other problems. It is not necessary for the embodiment to solve all of these problems. The above will become apparent from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the descriptions in the patent, claims, etc. [Means for solving the problem]

[0013] In the embodiment described below, a light source having a light emitting portion that spreads out in a plane emits light with high brightness for a short period of time. This includes an aspect of the present invention that has been created with a focus on a configuration that can illuminate the light.

[0014] The light-emitting device of one embodiment of the present invention includes a switching circuit for supplying a pulsed constant current and a The light emitting panel has a flow-supplied thereto.

[0015] In one aspect of the present invention, a constant current and a control pulse signal are provided, and a constant current pulse is provided. a constant current power supply capable of supplying a constant current; and a control pulse signal. A driving circuit having a start switch and a constant current pulse is provided. and a light-emitting panel.

[0016] The driving circuit is a switching circuit that supplies a constant current with a half-width of 1 millisecond or more and 1000 milliseconds or less. A control pulse signal is output in response to the opening and closing operation of the start switch so as to supply a control signal.

[0017] In another embodiment of the present invention, a light-emitting panel includes a support substrate and a light-emitting element extending in a planar manner over the support substrate. and a light-emitting element having a first electrode disposed closer to the support substrate than the second electrode, and a second electrode overlying the first electrode and an EL layer between the first electrode and the second electrode. It is located.

[0018] In another embodiment of the present invention, a light-emitting panel includes a curved surface, a flexible supporting substrate, The light emitting element has a first electrode and a first a second electrode overlapping the first electrode, and an EL layer between the first electrode and the second electrode. It is a light-emitting device.

[0019] In one aspect of the present invention, a constant current power supply includes an AC / DC converter that supplies a direct current, and a direct A DC-DC converter that is supplied with a constant current and can supply a constant current. In this specification, a device that converts AC current into DC current is referred to as an AC / DC A converter is a device that converts a DC voltage into a DC current of a different voltage. A constant current power supply is also constructed by using a current sensor and a DC-DC converter. It can be achieved.

[0020] Further, one embodiment of the present invention is a battery that supplies a first voltage, and a first A first DC-DC converter that supplies a second voltage higher than the voltage of the first DC-DC converter and a second DC-DC converter that supplies the second voltage. and a second capacitor that is powered by the capacitor and capable of supplying a constant current. The light emitting device has a DC-DC converter.

[0021] Further, one aspect of the present invention is a camera or digital camera including any one of the above-described light-emitting devices. It is a Tarsus still camera. Effect of the Invention

[0022] According to one embodiment of the present invention, a small-sized light-emitting device can be provided. We can provide placement. [Brief description of the drawings]

[0023] [Figure 1] 1A to 1C illustrate a structure of a light-emitting device according to an embodiment. [Diagram 2] 1A to 1C are diagrams illustrating a light-emitting panel according to an embodiment. [Diagram 3] 1A to 1C are diagrams illustrating a light-emitting panel according to an embodiment. [Figure 4] 1A to 1C are diagrams illustrating a light-emitting panel according to an embodiment. [Diagram 5] 1A to 1C are diagrams illustrating light-emitting elements according to an embodiment. [Figure 6] 1A to 1C are diagrams illustrating electronic devices according to an embodiment. [Figure 7]FIG. 4 is a graph showing voltage-luminance characteristics of the light-emitting panel of the embodiment. [Figure 8] FIG. 4 shows an emission spectrum of the light-emitting panel of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiment, and various changes and modifications may be made in the form and details without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that the above-mentioned invention can be obtained by the following embodiments. The present invention should not be construed as being limited to the contents described below. The same reference numerals are used in different drawings to indicate the same parts or parts having similar functions. A repeated explanation will be omitted.

[0025] (Embodiment 1) In this embodiment, a structure of a light-emitting device according to one embodiment of the present invention will be described with reference to FIGS. This will be explained with reference to (A-3).

[0026] FIG. 1A-1 is a block diagram illustrating a structure of a light-emitting device according to one embodiment of the present invention.

[0027] The light emitting device 100A described in this embodiment is supplied with a constant current and a control pulse signal. A switching circuit 110 capable of supplying a constant current pulse and a constant current A constant current DC power supply 140A and a start switch 132 are provided to supply a control pulse signal. and a light-emitting panel 120 to which a constant current pulse is supplied. The driving circuit 130 switches a constant current whose half-width is 1 millisecond or more and 1000 milliseconds or less. As circuit 110 provides, a control pulse signal is generated in response to the opening and closing of start switch 132. Output is

[0028] The light emitting device 100A described in this embodiment includes a switching circuit 11 for supplying a pulsed constant current. 0 and a light-emitting panel 120 to which a pulsed constant current is supplied. It is possible to expand the light emitting portion to which a pulsed constant current is supplied in a planar manner without increasing the thickness. As a result, a small-sized light-emitting device can be provided. Alternatively, a light-emitting device that is less likely to cause shadows can be provided. Can be provided.

[0029] The individual elements constituting the light emitting device 100A according to one embodiment of the present invention will be described below.

[0030] "Illuminating Panel" The light-emitting panel 120 includes a support substrate 401 and a light-emitting element 40 extending in a planar shape on the support substrate 401. The light emitting element 403 has a first electrode 421 on the supporting substrate 401 side, A second electrode 425 overlapping the first electrode 421, and a first electrode 421 and a second electrode 425 overlapping the first electrode 421 and the second electrode 425 An EL layer 423 is provided between them (see FIG. 2).

[0031] The light-emitting panel 120 has a light-emitting area of ​​5 cm 2 More than 200cm 2 Less than or equal to 15cm, preferably 2 More than 100cm 2 It spreads out in a surface area as shown below.

[0032] This makes the light-emitting panel 120 thinner and lighter than conventional xenon lamps. In addition, the heat generated by light emission is dispersed over a wide area of ​​the light-emitting panel 120. This effectively dissipates heat. This reduces heat accumulation in the light-emitting panel 120. Deterioration of 20 is suppressed.

[0033] In this specification, a layer provided between a pair of electrodes of the light-emitting element 403 is called an EL layer. Therefore, the light-emitting layer containing an organic compound, which is a light-emitting material, sandwiched between the electrodes is one embodiment of the EL layer. be.

[0034] By selecting and using a light-emitting organic compound, the light-emitting element can be made to emit white light. The panel 120 can be configured, for example, with a plurality of luminescent elements that emit complementary colors. Organic compounds that emit red, green, and blue light can also be used. Various emission spectra can be obtained from a variety of organic compounds. This allows the light emitting device 100A to have excellent white balance. can be obtained.

[0035] The use of light-emitting organic compounds allows for a wider range of light emission than light-emitting diodes that use inorganic materials. Light with a wide emission spectrum is close to natural light and is suitable for taking photographs. The display device is suitable for use in a display device having a flexible support substrate and an organic EL element on the support substrate. The light emitting panel having flexibility can be arranged along the curved surface of the housing. This allows the light emitting device to be arranged without compromising the design of the housing. For example, The flash can be positioned along the curved housing of the camera.

[0036] The configuration of light-emitting panel 120 will be described in detail in the second embodiment.

[0037] 《Constant current DC power supply》 The constant current DC power supply 140A consists of an AC / DC converter that supplies DC current and a and a DC-DC converter.

[0038] An example of a constant current supplied by a DC-DC converter is shown in Figure 1 (A-2).

[0039] <Drive circuit> The driver circuit 130 supplies a control pulse signal of a predetermined width.

[0040] The predetermined width is 1 millisecond or more and 1000 milliseconds or less, preferably 10 milliseconds or more and 100 Less than a millisecond.

[0041] For example, the start switch 132, the latch circuit and the monostable multivibrator The driver circuit 130 can be configured using the above-mentioned capacitor.

[0042] Specifically, a start switch 132 is used to supply a high or low signal to the latch circuit. The latch circuit supplies a trigger signal, and the monostable multi-channel The vibrator supplies a rectangular wave having a predetermined width as a control pulse signal.

[0043] In addition, a control pulse signal is supplied to the constant current DC power supply 140A, and the constant current DC power supply 140A is The DC-DC converter may be configured to be controlled using a control pulse signal. The timing of supplying the constant current may be controlled using a control pulse signal. It is possible to adjust the waveform of a constant current having a predetermined width, that is, a constant current pulse.

[0044] "Opening and closing circuit" The opening and closing circuit 110 supplies a constant current pulse to the light emitting panel while the constant current and control pulse signal are being supplied. Supply to Nel 120.

[0045] For example, the switching circuit 110 may be configured using a power transistor or a power FET. Specifically, a control pulse signal is supplied to the gate of the power transistor, and the first A constant current is supplied to the electrode, and the light-emitting panel 120 is electrically connected to the second electrode to form an opening / closing circuit 1 10 can be configured.

[0046] An example of the change over time of the constant current pulse supplied by the constant current DC power supply 140A is shown below. As shown in FIG. 1(A-3), for example, a current of 2 A is supplied to the light-emitting panel 120 for 50 milliseconds. It is possible.

[0047] <Modification> Regarding a light-emitting device exemplified as a modification of this embodiment, FIG. 1(B-1) to FIG. 1(B-3) are The following explanation will be given with reference to the above.

[0048] FIG. 1B-1 is a block diagram illustrating a structure of a light-emitting device according to one embodiment of the present invention.

[0049] The light emitting device 100B described with reference to FIG. 1(B-1) is the same as the light emitting device 100A described with reference to FIG. The light emitting device 100A has a configuration including a constant current DC power supply 140B and a counter circuit. The other configurations are the same as those of the light emitting device 100A described with reference to FIG. 1(A-1). Therefore, the above explanation should be taken into consideration.

[0050] <<Modification of constant current DC power supply>> The constant current DC power supply 140B described in the modified embodiment of the present invention is a battery that supplies a first voltage. A first DC / DC converter is provided to supply a first voltage and supplies a second voltage higher than the first voltage. a second voltage supply, a capacitor to which a second voltage is supplied, and a second power supply to which power is supplied from the capacitor. and a DC-DC converter.

[0051] The first DC-DC converter boosts the battery voltage to a second voltage and supplies it.

[0052] The capacitor is charged with a second voltage.

[0053] The second DC-DC converter is supplied with the power stored in the capacitor and supplies a constant current. do.

[0054] According to this configuration, while the capacitor supplies power to the second DC-DC converter, The second DC-DC converter can supply a constant current. When the power supplied to the second DC / DC converter falls below a certain value, the second DC / DC converter is no longer able to supply constant current. do.

[0055] FIG. 1(B-2) shows an example of the change over time of the current supplied by the constant current DC power supply 140B. As shown in.

[0056] The constant current DC power supply 140B is designed to have a width ( A constant current can be provided for a period of time longer than 50 milliseconds (e.g., 50 milliseconds). When current flows, the power stored in the capacitor is consumed, and eventually the constant current DC power supply 140B As a result, a current that is not a square wave is supplied to the light-emitting panel 120. As a result, the light-emitting panel 120 emits light at a brightness lower than the predetermined brightness and is not useful. In this way, the switching circuit 110 is designed to prevent unnecessary consumption of power. To prevent this, the supply of current can be stopped after a predetermined period of time. An example of the change over time of the current supplied by the switching circuit 110 is shown in FIG. show.

[0057] In this manner, the constant current DC power supply 140B can supply a constant current using a battery. This makes it possible to provide light emitting device 100B that is easy to carry.

[0058] Counter Circuit The counter circuit 150 counts the number of times the drive circuit 130 has supplied a control pulse signal. This allows the number of times that light-emitting panel 120 has been illuminated to be known.

[0059] For example, the luminance of the light-emitting panel 120 decreases depending on the number of times the light-emitting panel 120 is illuminated. This may be the case.

[0060] In order to compensate for the reduced brightness of the light-emitting panel 120, the counter circuit 150 accumulates the The number of times the control pulse is output may be fed back to the drive circuit 130 to increase the width of the control pulse signal.

[0061] Alternatively, in order to compensate for the reduced brightness of the light-emitting panel 120, the counter circuit 150 The integrated number of times is fed back to the constant current DC power supply 140B. The magnitude of the constant current supplied by B may be increased.

[0062] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification. .

[0063] (Embodiment 2) In this embodiment, a structure of a light-emitting panel that can be used in a light-emitting device according to one embodiment of the present invention will be described. This will be described with reference to FIGS.

[0064] <Light-emitting panel configuration example 1> FIG. 2A is a plan view illustrating a light-emitting panel according to one embodiment of the present invention, and FIG. FIG. 2 is a cross-sectional view of A taken along dashed line AB.

[0065] The light-emitting panel shown in FIGS. 2(A) and 2(B) includes a support substrate 401, a sealing substrate 405, and a sealing material 40 The light emitting element 403 is provided in a space 415 surrounded by the bottom emitter 417. Specifically, the organic EL element has a support substrate 401 on which a transparent layer for visible light is formed. A first electrode 421 is provided, an EL layer 423 is provided on the first electrode 421, and a A second electrode 425 is provided that reflects visible light.

[0066] The light-emitting element applied to one embodiment of the present invention is not limited to a bottom emission structure. Regarding the structure of a light-emitting element that can be applied to one embodiment of the present invention, This will be described in detail in embodiment 3.

[0067] The first terminal 409a is electrically connected to the auxiliary wiring 417 and the first electrode 421. An insulating layer 419 is provided on the electrode 421 in a region overlapping with the auxiliary wiring 417 . The first terminal 409a and the second electrode 425 are electrically insulated by an insulating layer 419. The second terminal 409b is electrically connected to the second electrode 425. 4 shows a configuration in which the first electrode 421 is formed on the auxiliary wiring 417. An auxiliary wiring 417 may be formed on the layer 421 .

[0068] It is preferable that the light extraction structure 411a is provided at the interface between the support substrate 401 and the atmosphere. By providing a light extraction structure 411a at the interface between the support substrate 401 and the light source 402, the light is not emitted to the atmosphere due to the effect of total reflection. This reduces the amount of light that cannot be extracted, thereby improving the light extraction efficiency of the light-emitting panel.

[0069] In addition, a light extraction structure 411b is provided between the light emitting element 403 and the support substrate 401. When the light extraction structure 411b has projections and recesses, the light extraction structure 411b and the first It is preferable to provide a planarization layer 413 between the first and second electrodes 421. The first electrode 421 can be a flat film, and the unevenness of the first electrode 421 in the EL layer 423 can be compensated for. The occurrence of leakage current caused by the above problem can be suppressed. Since the light extraction structure 411b is provided at the interface with the light source 01, the light cannot be extracted to the atmosphere due to total reflection. This reduces unobstructed light and improves the light extraction efficiency of the light-emitting panel.

[0070] The light extraction structure 411a and the light extraction structure 411b are made of a material such as resin. In addition, the light extraction structure 411a and the light extraction structure 411b may be Hemispherical lenses, microlens arrays, films with uneven structures, light diffusion films, etc. For example, the lens or film may be mounted on a support substrate 401. 401 or the lens or film is bonded using an adhesive having a refractive index similar to that of the lens or film. By this, the light extraction structure 411a and the light extraction structure 411b can be formed. .

[0071] The planarization layer 413 has a surface in contact with the first electrode 421 rather than a surface in contact with the light extraction structure 411b. The planarizing layer 413 is made of a material having a light-transmitting property and a high refractive index. Materials that can be used (for example, liquid substances such as refractive liquids, glass, resins, etc.) can be used.

[0072] Note that the light-emitting panel of one embodiment of the present invention may have a structure without a light extraction structure. In that case, the second electrode that reflects visible light can be preferably used as a mirror.

[0073] <Light-emitting panel configuration example 2> FIG. 3 is a plan view of a light-emitting panel according to one embodiment of the present invention. FIG. 3 is a cross-sectional view taken along dashed line XY of FIG.

[0074] In the light-emitting panel shown in FIG. 4A, a light-emitting element is disposed on a support substrate 1220 via an insulating film 1224. Auxiliary wiring 1206 is provided on the insulating film 1224. , electrically connected to the first electrode 1201. The end of the first electrode 1201 and the terminal 1210 The end of the first electrode 1201 is covered with a partition wall 1205. A partition wall 1205 is provided to cover the light emitting element 1250. The light emitting element 1250 is made of a support substrate 1220, an encapsulant 1220, and a light emitting device 1250. The support substrate 1220 is sealed by a sealing material 1227. A light extraction structure 1209 is attached to the support substrate 1220 and the sealing substrate 122. By using a flexible substrate for 8, a flexible light-emitting panel can be realized.

[0075] The light emitting element 1250 is an organic EL element having a bottom emission structure. A first electrode 1201 that transmits visible light is provided on the plate 1220. The device has an L layer 1202 and a second electrode 1203 that reflects visible light on the EL layer 1202. .

[0076] In the light-emitting panel shown in FIG. 4B, the support substrate 122 of the light-emitting panel shown in FIG. Instead of the light extraction structure 1209 and the light extraction structure 1209, a support substrate 1229 having a light extraction structure is provided. The support substrate 1229 functions as a support and also as a light extractor for the light-emitting panel. It has both functions of improving efficiency.

[0077] Here, when manufacturing a flexible light-emitting panel, a light-emitting element is formed on a flexible substrate. As a method for forming the light-emitting element, for example, a first method is to directly form the light-emitting element on a flexible substrate. The method is to form a substrate having a high heat resistance different from the flexible substrate (hereinafter, referred to as a "fabrication substrate"). After the light emitting element is formed, the light emitting element is peeled off from the formation substrate, and the light emitting element is attached to a flexible substrate. There is a second way to transpose children:

[0078] For example, a thin glass substrate that is flexible may be used in the manufacturing process of a light-emitting element. When a substrate having heat resistance to the temperature at which the substrate is to be heated is used, the first method can be used to perform the process. This is preferred because of simplicity.

[0079] In addition, by applying the second method, it is possible to easily remove the insulating film or the like having low water permeability formed on the substrate. It can be transferred to a flexible substrate. Therefore, it is possible to use a substrate with high water permeability and low heat resistance. Even if a flexible substrate made of a resin such as a resin is used, a flexible and highly reliable emitter can be obtained. Light panels can be made.

[0080] <Materials for luminous panels> An example of a material that can be used for the light-emitting panel of one embodiment of the present invention will be described.

[0081] [substrate] The substrate on the side from which the light from the light emitting element is extracted is made of a material that transmits the light. For example, glass Materials such as quartz, ceramic, sapphire, and organic resins can be used.

[0082] By using a substrate with a thin film thickness, the light-emitting panel can be made lighter and thinner. By using a substrate that is thick enough to be flexible, a flexible light-emitting panel can be realized. In addition, the flexible light-emitting panel can be folded and stored when not in use. This allows it to be used as a board reflector in a photo studio. In addition, it can be used as a lighting device that flashes light over a wide area. A collapsible lighting device may be provided.

[0083] Examples of glass include non-alkali glass, barium borosilicate glass, and aluminoboron glass. Silicate glass or the like can be used.

[0084] Examples of materials having flexibility and transparency to visible light include flexible materials. Thick glass, polyethylene terephthalate (PET), polyethylene naphthalate ( PEN) and other polyester resins, polyacrylonitrile resins, polyimide resins, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES ) resin, polyamide resin, cycloolefin resin, polystyrene resin, polyamide-imide Resin, polyvinyl chloride resin, etc. In particular, it is preferable to use materials with a low thermal expansion coefficient. For example, polyamide-imide resin, polyimide resin, PET, etc. are preferably used. In addition, it is possible to use a substrate in which glass fibers are impregnated with organic resin, or an inorganic filler is impregnated with organic resin. It is also possible to use a substrate with a lower thermal expansion coefficient by mixing materials such as Because of its light weight, the light-emitting panel using the substrate can also be made lightweight.

[0085] In addition, the substrate on the side from which light is not extracted does not need to have light-transmitting properties. In addition to the substrate, a metal substrate using a metal material or an alloy material can also be used. and alloy materials have high thermal conductivity and easily conduct heat to the entire encapsulation substrate, making it possible to This is preferable because it is possible to suppress local temperature rises. The thickness of the metal substrate is preferably 10 μm or more and 200 μm or less, and more preferably 20 μm or more and 50 μm or less. It is more preferable that there is.

[0086] The material constituting the metal substrate is not particularly limited, but examples thereof include aluminum, copper, and nickel. It is preferable to use metal alloys such as aluminum alloys and stainless steel. can be done.

[0087] In addition, the surface of a conductive substrate may be oxidized or an insulating film may be formed on the surface to perform insulation treatment. For example, a coating method such as spin coating or dipping may be used. The insulating film may be formed by electrochemical deposition, vapor deposition, sputtering, or the like. In addition to leaving it in the atmosphere or heating it, an oxide film is formed on the surface of the substrate by anodizing or other methods. You may do so.

[0088] As for the flexible substrate, the layer using the above-mentioned material protects the surface of the light-emitting panel from scratches, etc. Hard coat layers (e.g., silicon nitride layers, etc.) and layers of materials that can disperse pressure (e.g., The light-emitting layer may be laminated with a layer of a polyester resin, an aramid resin layer, etc. In order to prevent the deterioration of the element's lifespan, etc., nitrogen and silicon nitride films, etc. Low water permeability films such as films containing silicon and films containing nitrogen and aluminum, such as aluminum nitride films An insulating film may be provided.

[0089] The substrate may be formed by laminating a plurality of layers. In particular, when the substrate has a glass layer, This improves the barrier properties against water and oxygen, thereby making it possible to provide a highly reliable light-emitting panel.

[0090] For example, a substrate having a glass layer, an adhesive layer, and an organic resin layer laminated thereon from the side closer to the light emitting element is used. The thickness of the glass layer is from 20 μm to 200 μm, preferably The thickness of the glass layer is 25 μm or more and 100 μm or less. A glass layer with such a thickness has high resistance to water and oxygen. The thickness of the organic resin layer is set to 10 μm or less. The thickness of the organic resin layer is set to 200 μm or less, and preferably 20 μm or more and 50 μm or less. By providing the outer side of the glass layer, it is possible to suppress breakage or cracks in the glass layer and to prevent mechanical The strength can be improved. When such a composite material of glass and organic resin is applied to the substrate, By using this, a highly reliable and flexible light-emitting panel can be obtained.

[0091] [Insulating film] An insulating film may be formed between the support substrate and the light emitting element. The insulating film may be a silicon oxide film, a nitride film, or the like. Inorganic insulating films such as silicon nitride films, silicon oxynitride films, and silicon nitride oxide films are used. In particular, in order to prevent moisture from entering the light-emitting element, a silicon oxide film or a silicon nitride film is used. It is preferable to use an insulating film having low water permeability, such as a PET film or an aluminum oxide film. An insulating film may be provided to cover the light emitting element using a target or material.

[0092] [Bulkhead] The partition wall can be made of an organic resin or an inorganic insulating material. , polyimide resin, polyamide resin, acrylic resin, siloxane resin, epoxy resin, or The insulating material may be a phenol resin or the like. Silicon nitride, etc. can be used. Photosensitive resin is particularly preferred because it makes it easier to fabricate the partition walls. It is preferable to use:

[0093] The method for forming the partition wall is not particularly limited, and may be, for example, a photolithography method, a sputtering method, or a vapor deposition method. method, droplet ejection method (inkjet method, etc.), printing method (screen printing, offset printing, etc.) etc. can be used.

[0094] [Auxiliary wiring] Although it is not necessary to provide an auxiliary wiring, it is recommended to provide one in order to suppress the voltage drop caused by the resistance of the electrodes. Therefore, it is preferable to provide such a filter.

[0095] The materials for the auxiliary wiring are copper (Cu), titanium (Ti), tantalum (Ta), and tungsten (W ), Molybdenum (Mo), Chromium (Cr), Neodymium (Nd), Scandium (Sc), Nickel (Ni), or alloy materials mainly composed of these, The auxiliary wiring may be formed by laminating or stacking. Aluminum may also be used as the material for the auxiliary wiring. In that case, a laminated structure is used to prevent corrosion problems, and the layers that do not come into contact with ITO, etc. The thickness of the auxiliary wiring should be between 0.1 μm and 3 μm. The thickness is preferably 0.1 μm or more and 0.5 μm or less.

[0096] When paste (such as silver paste) is used as the material for the auxiliary wiring, the metal that constitutes the auxiliary wiring becomes granular. As a result, the surface of the auxiliary wiring becomes rough and has many gaps, and the EL layer It is difficult to completely cover the auxiliary wiring, and it is difficult to electrically connect the upper electrode and the auxiliary wiring. This is easier and more preferable.

[0097] [Sealing material] The sealing method of the light-emitting panel is not limited, and may be, for example, solid sealing or hollow sealing. For example, glass materials such as glass frit and two-part mixed resins that harden at room temperature are Resin materials such as a curable resin, a photocurable resin, and a thermosetting resin can be used. The light panels may be filled with an inert gas such as nitrogen or argon and are made of PVC (polyvinyl chloride). Vinyl chloride resin, acrylic resin, polyimide resin, epoxy resin, silicone resin grease, PVB (polyvinyl butyral) resin, EVA (ethylene vinyl acetate) resin, etc. It may be filled with resin, and the resin may contain a desiccant.

[0098] [Light extraction structure] The light extraction structure includes a hemispherical lens, a microlens array, and a filter with a concave-convex structure. For example, the above-mentioned lens or film may be provided on a substrate. The substrate, lens or film is bonded to the substrate using an adhesive or the like having a refractive index similar to that of the substrate, lens or film. By bonding the light, a light extraction structure can be formed.

[0099] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification. .

[0100] (Embodiment 3) In this embodiment, a light-emitting element that can be used in a light-emitting device of one embodiment of the present invention is illustrated. 5 will be used to explain.

[0101] Example of the configuration of the light-emitting element The light-emitting element shown in FIG. 5A has an EL layer 20 between a first electrode 201 and a second electrode 205. In this embodiment, the first electrode 201 functions as an anode, and the second electrode 20 5 functions as the cathode.

[0102] A voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 201 and the second electrode 205. Then, holes are injected into the EL layer 203 from the first electrode 201 side, and electrons are injected into the EL layer 203 from the second electrode 205 side. The injected electrons and holes recombine in the EL layer 203, and the EL layer 20 The luminescent substance contained in 3 emits light.

[0103] The EL layer 203 includes at least a light-emitting layer 303 containing a light-emitting substance.

[0104] In addition, the EL layer 203 is formed of a material having a high hole injection property and a material having a high hole transport property as a layer other than the light emitting layer. A material having a high electron transporting property, a material having a high electron injecting property, or a bipolar material (electron The EL layer 203 may further include a layer containing a substance having high electron transport and hole transport properties. Both low molecular weight compounds and high molecular weight compounds can be used, including inorganic compounds. It's okay to be.

[0105] The light-emitting element shown in FIG. 5B has an EL layer 20 between a first electrode 201 and a second electrode 205. 3, and the EL layer 203 includes a hole injection layer 301, a hole transport layer 302, a light emitting layer 303, An electron transport layer 304 and an electron injection layer 305 are laminated in this order from the first electrode 201 side. is.

[0106] As shown in FIG. 5C and FIG. 5D, the light-emitting element In this case, an intermediate layer may be provided between the stacked EL layers. It is preferable to provide the intermediate layer 207. The intermediate layer 207 has at least a charge generating region.

[0107] For example, the light-emitting element shown in FIG. 5C includes a first EL layer 203a and a second EL layer 203b. The light-emitting element shown in FIG. 5D has an n-layer EL layer (n is a natural number of 2 or more), and an intermediate layer 207 is provided between each EL layer.

[0108] The electric field in the intermediate layer 207 provided between the EL layer 203(m) and the EL layer 203(m+1) The behavior of electrons and holes will be described. When a voltage higher than the threshold voltage of the molecule is applied, holes and electrons are generated in the intermediate layer 207, and the positive The holes move to the EL layer 203(m+1) provided on the second electrode 205 side, and the electrons move to the EL layer 203(m+1) provided on the second electrode 205 side. Moves to the EL layer 203(m) provided on the electrode 201 side. Injected into the EL layer 203(m+1) The holes are recombined with the electrons injected from the second electrode 205 side, and the EL layer 203 ( The light-emitting material contained in the EL layer 203(m+1) emits light. The electrons injected into the EL layer 203(m) emit light. The electrons recombine with the holes injected from the first electrode 201 side and are contained in the EL layer 203(m). The luminescent material emits light. Therefore, the holes and electrons generated in the intermediate layer 207 are Light emission occurs in the different EL layers.

[0109] In addition, when the EL layers are provided in contact with each other, the same structure as the intermediate layer is formed between them. In the above, the EL layers can be provided in contact with each other without an intermediate layer. When a charge generating region is formed on a surface, an EL layer can be provided in contact with the surface.

[0110] In addition, by making the emission color of each EL layer different, the light-emitting device as a whole can have a desired color. For example, in a light-emitting device having two EL layers, the first By making the emission color of the first EL layer and the emission color of the second EL layer complementary to each other, It is also possible to obtain a light-emitting device that emits white light as a whole. The same applies to the case of a light emitting element having a

[0111] <Light-emitting element materials> Examples of materials that can be used for each layer are given below. Each layer is not limited to a single layer. Two or more layers may be laminated.

[0112] <anode> The electrode (first electrode 201) functioning as an anode is made of a conductive metal, an alloy, or a conductive material. In particular, the material having a large work function (4.0 For example, indium tin oxide (ITO) is preferably used. Indium Tin Oxide, silicon or silicon oxide-containing indium tin oxide Indium oxide containing tungsten oxide and zinc oxide, Graphene, gold, platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, Examples include copper, palladium, and nitrides of metallic materials (eg, titanium nitride).

[0113] In addition, when the anode contacts the charge generating region, various conductive materials can be used without considering the magnitude of the work function. For example, aluminum, silver, and alloys containing aluminum can be used. There can be.

[0114] <cathode> The electrode functioning as a cathode (second electrode 205) is made of a conductive metal, an alloy, or a conductive material. In particular, the material having a small work function (3. For example, it is preferable to use a material that belongs to Group 1 or Group 2 of the periodic table. Elements that cause oxidation (e.g., alkali metals such as lithium and cesium, calcium, strontium, etc.) Alkaline earth metals such as magnesium, alloys containing these elements (e.g. Mg-Ag , Al-Li), europium, ytterbium and other rare earth metals, Examples of materials that can be used include alloys of tantalum, aluminum, and silver.

[0115] In addition, when the cathode is in contact with the charge generating region, various conductive materials can be used without considering the magnitude of the work function. For example, ITO, indium containing silicon or silicon oxide, Tin oxide and the like can also be used.

[0116] The electrodes may be formed by vacuum deposition or sputtering. When a paste or the like is used, a coating method or an ink-jet method may be used.

[0117] <Hole injection layer 301> The hole injection layer 301 is a layer containing a substance with high hole injection properties.

[0118] Examples of materials with high hole injection properties include molybdenum oxide, vanadium oxide, and ruthenium oxide. Metal oxides such as tungsten oxide, manganese oxide, etc., and phthalocyanine oxide, etc. Phthalocyanine (abbreviation: HPc), copper(II) phthalocyanine (abbreviation: CuPc), etc. Compounds of the nin series can be used.

[0119] In addition, poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenyl Polymer compounds such as poly(3,4-ethylenediamine) (abbreviation: PVTPA) and poly(3,4-ethylenediamine) Poly(dithiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) and other acid-added A polymer compound can be used.

[0120] The hole injection layer 301 may also serve as a charge generating region. When the charge generation region is the charge generation region, various conductive materials can be used for the anode without considering the work function. The materials constituting the charge generating region will be described later.

[0121] <Hole transport layer 302> The hole transport layer 302 is a layer containing a substance with a high hole transport property.

[0122] The material having a high hole transporting property may be any material having a higher hole transporting property than an electron transporting property. , 10 -6 cm 2 It is preferable that the material has a hole mobility of 0.1 V or more. For example, 4,4'-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NP B or α-NPD), 4-phenyl-4'-(9-phenylfluoren-9-yl)trimethyl Aromatic amine compounds such as phenylamine (abbreviation: BPAFLP), 4,4'-di(N-phenylamine) Rubazolyl)biphenyl (abbreviation: CBP), 9-[4-(10-phenyl-9-anthracene 9-phenyl-3-[4-(phenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 10-Phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA ), carbazole derivatives such as 2-tert-butyl-9,10-di(2-naphthyl)an t-BuDNA, 9,10-di(2-naphthyl)anthracene (abbreviation Aromatic carbonization such as DNA, 9,10-diphenylanthracene (DPAnth) Various compounds can be used, including hydrogen compounds, polymer compounds such as PVK and PVTPA. Cut.

[0123] <Light-emitting layer 303> The light-emitting layer 303 is made of a fluorescent compound that emits fluorescence or a phosphorescent compound that emits phosphorescence. This can be done.

[0124] Examples of fluorescent compounds that can be used in the light-emitting layer 303 include N,N'-bis[4 -(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4 ,4'-diamine (abbreviation: YGA2S), N-(9,10-diphenyl-2-anthryl )-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), Bren et al.

[0125] In addition, examples of phosphorescent compounds that can be used in the light-emitting layer 303 include bis[2-( 4',6'-Difluorophenyl)pyridinato-N,C 2’ ]Iridium(III) pico Linate (abbreviation: FIrpic), Tris(2-phenylpyridinato-N,C 2’ ) Ili Ir(ppy)3)(acetylacetonato)bis(3,5-diacetylacetonate) Methyl-2-phenylpyrazinate)iridium(III) (abbreviation: Ir(mppr-Me )2(acac) and other organometallic complexes.

[0126] The light-emitting layer 303 is formed by dissolving the above-mentioned light-emitting organic compound (light-emitting substance, guest material) in another material. The host material may be a material in which the cations are dispersed. It is possible to obtain a LUMO level higher than that of the guest material and a highest occupied It is preferable to use a substance with a low orbital level (HOMO level).

[0127] By dispersing the guest material in the host material, crystallization of the light-emitting layer 303 is suppressed. In addition, it is possible to suppress concentration quenching caused by a high concentration of the guest material. can be done.

[0128] As the host material, the above-mentioned substances having high hole transport properties (e.g., aromatic amine compounds and carbene compounds) are used. and highly electron-transporting substances (e.g., quinoline or benzoxazole derivatives) described later. Metal complexes having a tetrahydrofuran skeleton, oxazole-based ligands or thiazole-based ligands Metal complexes) can be used. Specifically, tris(8-quinolinolato)aluminium complexes can be used. Al(III) (abbreviation: Alq), bis(2-methyl-8-quinolinolato)(4-phenyl Alphenolato)aluminum(III) (abbreviation: BAlq), and other metal complexes, Biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4- Triazole (abbreviation: TAZ), Bathophenanthroline (abbreviation: BPhen), Bathocu Heterocyclic compounds such as proine (abbreviation: BCP), CzPA, DNA, t-BuDNA, Condensed aromatic compounds such as DPAnth and aromatic amine compounds such as NPB can be used. can.

[0129] In addition, multiple host materials can be used. For example, rubrene can be used to suppress crystallization. A substance that suppresses crystallization, such as fluorine, may be further added. In order to make the transfer more efficient, NPB, Alq or the like may be further added.

[0130] In addition, by providing multiple light-emitting layers and making each layer emit a different color, As a whole, it is possible to obtain light of a desired color. For example, in a light-emitting device having two light-emitting layers, In the present invention, the luminescent color of the first luminescent layer and the luminescent color of the second luminescent layer are made to have a complementary color relationship. It is also possible to obtain a light emitting element that emits white light as a whole. The same applies to the case of a light emitting element having three or more.

[0131] <Electron transport layer 304> The electron transporting layer 304 is a layer containing a substance with a high electron transporting property.

[0132] As a substance having a high electron transporting property, an organic compound having a higher electron transporting property than a hole transporting property may be used. , especially, 10 -6 cm 2 It is preferable that the material has an electron mobility of .beta. / Vs or more.

[0133] Examples of the material with high electron transporting properties include quinoline or benzoate structures such as Alq and BAlq. Metal complexes with the benzoquinoline skeleton, etc., and bis[2-(2-hydroxyphenyl)benzoyl] xazolato]zinc (abbreviation: Zn(BOX)2), bis[2-(2-hydroxyphenyl) Benzothiazolato]zinc (abbreviated as Zn(BTZ)2) and other oxazoles and thiazoles Metal complexes having ligands such as TAZ, BPhen, and BC can also be used. P can also be used.

[0134] <Electron injection layer 305> The electron injection layer 305 is a layer containing a substance with high electron injection properties.

[0135] Examples of materials with high electron injection properties include lithium, cesium, calcium, and lithium fluoride. Alkali metals such as fluoride, cesium fluoride, calcium fluoride, lithium oxide, etc. Alkali-earth metals or their compounds can be used. Also, erbium fluoride The above rare earth metal compound can be used. It is also possible to use a substance that

[0136] <Charge Generation Region> The charge generation region is made by adding an electron acceptor to an organic compound with high hole transport properties. Even if the structure is the same, the structure is one in which an electron donor (donor) is added to an organic compound with high electron transport properties. Also, both of these configurations may be laminated.

[0137] As the organic compound having high hole transport properties, for example, the above-mentioned organic compound can be used for the hole transport layer. Examples of organic compounds having high electron transport properties include the above-mentioned electron transport layer. Examples of materials that can be used include:

[0138] In addition, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroethylene is used as an electron acceptor. Examples of the fluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, etc. Further, transition metal oxides can be mentioned. Examples of the oxides of metals belonging to the group include vanadium oxide, niobium oxide, Tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, lanthanum oxide Molybdenum oxide is preferred because it has high electron-accepting properties. In particular, molybdenum oxide is stable in the atmosphere. This is preferable because it has low hygroscopicity and is easy to handle.

[0139] The electron donor may be an alkali metal, an alkaline earth metal, a rare earth metal, or an elemental Metals belonging to Group 13 of the periodic table and their oxides and carbonates can be used. Generally, lithium, cesium, magnesium, calcium, ytterbium, and indium It is preferable to use tetrathiazol-1, lithium oxide, cesium carbonate, etc. Organic compounds such as benzene may be used as electron donors.

[0140] The layers constituting the EL layer 203 and the intermediate layer 207 are formed by deposition (vacuum deposition). It can be formed by methods such as deposition method, transfer method, printing method, inkjet method, coating method, etc. can.

[0141] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification. .

[0142] (Embodiment 4) In this embodiment, an electronic device using a light-emitting device according to one embodiment of the present invention will be described with reference to FIGS. Reveal.

[0143] The light-emitting device of one embodiment of the present invention can be used as a flash or a photographing function for a digital still camera or the like. A camera equipped in a mobile phone (also called a mobile phone or mobile phone device) or a mobile information terminal having the It can be used for flashing lights, etc. It can also be used for illumination such as warning lights, lighthouses, and decorative purposes. It can be used for applications such as

[0144] FIG. 6A shows an example of a digital still camera. Digital still camera 7300 The light-emitting device 7310 includes a housing 7301, a lens 7304, and a light-emitting device 7310. The light-emitting device according to one embodiment of the present invention is applied to the light-emitting portion 7303 of the light-emitting device 7310. The light-emitting device according to one embodiment of the present invention has flexibility. In the digital still camera 7300, the non-light emitting portion 73 7301. The lens 7305 is bent to fit the shape of the housing 7301. This allows the camera to be placed widely around the 304. This makes it possible to take pictures of people's faces in dark places using a flash. Even if a shadow is cast on the face, for example, the shadow of the nose can be made less likely to be cast on the cheek. A light element is fabricated in the non-light-emitting part 7305 in the same process and installed as an indicator showing the operating state. It may be used.

[0145] 6B and 6C show an example of a mobile phone. The rear surface of the one surface (which can also be called the back surface) is shown in FIG. 6(C). . The mobile phone 7350 includes a housing 7351, a display unit 7352, a lens 7354, and a lens 7355. The light-emitting device 7360 includes the light-emitting device of one embodiment of the present invention. The light emitting device 7360 has a light emitting portion 7353 and a non-light emitting portion 7355. The light-emitting portion 7353 is disposed so as to surround the lens 7354. It may also be designed to be used as a mirror at times.

[0146] When the subject is on the display unit 7352 side, the display unit 7352 is The entire surface or part of the light source can be used to take pictures using the lens 7356. In this case, the display portion 7352 can be switched to a light-emitting portion just before shooting. For example, The entire display unit 7352 or a part of it is used as a display unit for displaying a subject, and the display is turned on immediately before shooting. Similarly, the entire or part of the light-emitting portion 7353 may be used as a display portion. There can be.

[0147] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification. . EXAMPLES

[0148] In this example, a light-emitting device according to one embodiment of the present invention will be described.

[0149] FIG. 3 shows a plan view of the light-emitting panel produced in this embodiment. A cross-sectional view is shown in Fig. 4(B). Note that part of the configuration of the light-emitting panel is omitted in Fig. 3.

[0150] As shown in FIG. 4B, the light-emitting panel of this embodiment includes a support substrate 1 having a light extraction structure. A light emitting element 1250 is provided on the insulating film 1224. An auxiliary wiring 1206 is provided on the first electrode 1201 and is electrically connected to the first electrode 1201. An end of the first electrode 1201 and an end of the terminal 1210 are covered with a partition wall 1205. A partition wall 1205 is provided to cover the auxiliary wiring 1206 with the first electrode 1201 interposed therebetween. The optical element 1250 is sealed by a support substrate 1229, a sealing substrate 1228, and a sealing material 1227. It has been stopped.

[0151] In the light-emitting panel of this embodiment, a polyester resin diffusion film is used as the support substrate 1229. A thin glass layer and polyethylene terephthalate (PET) were used as the sealing substrate 1228. The substrates used in this example were flexible. The light-emitting panel of this embodiment has a light-emitting area of ​​100 mm. It is 56mm x 42mm.

[0152] The light emitting element 1250 is an organic EL element having a bottom emission structure. A first electrode 1201 that transmits visible light is provided on the plate 1229. The device has an L layer 1202 and a second electrode 1203 that reflects visible light on the EL layer 1202. .

[0153] A method for manufacturing the light-emitting panel of this embodiment will be described.

[0154] First, a base film, a peeling layer (tungsten film), and a layer to be peeled are formed on a glass substrate, which is a substrate for fabrication. In this embodiment, the layers to be peeled are the insulating film 1224 and the auxiliary wiring 1206. , a first electrode 1201 , and a partition wall 1205 .

[0155] A total of seven auxiliary wirings 1206 were formed on the insulating film 1224. The first electrode had a thickness of 5.3 mm and a width of 322 μm. As the 1201, an indium tin oxide (ITSO) film containing silicon oxide was formed. A total of seven partition walls 1205 covering the wiring 1206 were formed so that the width L1 was 330 μm.

[0156] Next, the temporary support substrate and the first electrode 1201 are bonded together using a peeling adhesive, and a peeling layer is formed. The layer to be peeled off was peeled off from the prepared substrate using a tungsten carbide (TFT). can be done.

[0157] Next, the layer to be peeled off from the substrate is peeled off, and the insulating film 1224 is exposed. The support substrate 1229 was attached using a bonding agent. A polyester resin diffusion film was used. After that, the temporary support substrate was peeled off, and the support substrate 1 was A first electrode 1201 was exposed on 229 .

[0158] Next, an EL layer 1202 and a second electrode 1203 were formed on the first electrode 1201. The layer 1202 is a light-emitting layer containing a fluorescent compound that emits blue light from the first electrode 1201 side. A first EL layer having a layer, an intermediate layer, and an emitting layer including a phosphorescent compound exhibiting green emission. A second EL layer having a light-emitting layer containing a phosphorescent compound that emits red light is stacked in this order. The second electrode 1203 was made of silver.

[0159] Next, a photocurable resin containing zeolite is applied as the sealing material 1227, and then irradiated with ultraviolet light. Then, the support substrate 1229 and the sealing substrate 1229 were bonded together using an ultraviolet light curing adhesive. Plate 1228 has a thin glass layer and a polyethylene terephthalate (PET) layer. The substrate and the substrate were bonded together.

[0160] The operating characteristics of the light-emitting panel obtained in the above manner were measured. The voltage-luminance characteristic of the light-emitting panel is shown as "initial" in the legend of FIG. The spectrum is shown in FIG. 8. As shown in FIG. 8, the light-emitting panel of this embodiment emits blue light. fluorescent compounds that emit green light, phosphorescent compounds that emit red light, and It was found that the emission spectrum contained light originating from each of these.

[0161] After that, a reliability test was carried out on a light-emitting device using the light-emitting panel. The light panel was flashed 3,000 or 10,000 times at intervals. A current of 2A was applied to the panel for 50 milliseconds (ms). The interval between light emission (non-light emission time) was The time was set to 10 seconds.

[0162] Figure 7 shows the voltage-luminance characteristics of the light-emitting panel after 3,000 flashes and after 10,000 flashes. show.

[0163] From Figure 7, it can be seen that the voltage-luminance characteristics of the light-emitting panel remain almost the same as before the reliability test even after 10,000 light emission cycles. There was almost no change, and no deterioration of the light-emitting panel was observed. This demonstrated the high reliability of the light-emitting device. [Explanation of symbols]

[0164] 100A Light Emitting Device 100B Light emitting device 110 Opening and closing circuits 120 Light-emitting panel 130 Drive circuit 132 Start switch 140A constant current DC power supply 140B constant current DC power supply 150 Counter Circuit 201 First electrode 203 EL layer 203a EL layer 203b EL layer 205 Second electrode 207 Middle Class 301 Hole injection layer 302 Hole transport layer 303 Light-emitting layer 304 Electron transport layer 305 Electron injection layer 401 Support substrate 403 Light emitting element 405 Sealing substrate 407 Sealing material 409a Terminal 409b Terminal 411a Light extraction structure 411b Light extraction structure 413 Planarization layer 415 Space 417 Auxiliary wiring 419 Insulating Layer 421 First electrode 423 EL layer 425 Second Electrode 1201 First electrode 1202 EL layer 1203 Second electrode 1205 Bulkhead 1206 Auxiliary wiring 1209 Light extraction structure 1210 Terminal 1220 Support substrate 1224 Insulating film 1227 Sealing material 1228 Sealing substrate 1229 Support Substrate 1250 Light emitting element 7300 Digital Still Camera 7301 Case 7303 Light emitting part 7304 Lens 7305 Non-light-emitting part 7310 Light emitting device 7350 Mobile Phone 7351 Case 7352 Display section 7353 Light emitting part 7354 Lens 7355 Non-luminous part 7360 Light Emitting Device

Claims

[Claim 1] A switching circuit that is supplied with a constant current and a control pulse signal and can supply a constant current pulse; A constant current power source capable of supplying the constant current; a drive circuit capable of supplying the control pulse signal and including a start switch; a light-emitting panel to which the constant current pulse is supplied, The drive circuit outputs the control pulse signal in response to the opening and closing operation of the start switch so that the opening and closing circuit supplies a constant current whose half-value width is 1 millisecond or more and 1000 milliseconds or less.

Images