Electronic apparatus

Abstract

To provide a light-emitting device capable of adjusting an amount of light, a light-emitting device with high reliability, a light-emitting device with low power consumption, a light-emitting device being less likely to cause a shadow, or a small-sized light-emitting device.SOLUTION: There is provided a light-emitting device capable of adjusting an amount of light by controlling a magnitude of a constant-current pulse by a control signal. Specifically, the light-emitting device is provided that includes: a constant-current power source being supplied with the control signal and a control pulse signal and supplying the constant-current pulse; a control device supplying the control signal; a drive circuit supplying the control pulse signal; and a light-emitting panel to which the constant-current pulse is supplied. The control signal is a signal for controlling the magnitude of the constant-current pulse. The light-emitting panel has a light-emitting element, and the light-emitting element has a current density of 10 mA / cm2 or more and 1000 mA / cm2 or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to a light-emitting device, an electronic device, and a driving method thereof. In particular, one aspect of the present invention relates to a light-emitting device, an electronic device using an organic electroluminescence (hereinafter also referred to as EL) phenomenon, and a driving method thereof.

Background Art

[0002] Research and development of a light-emitting element using organic EL (also referred to as an organic EL element) have been actively conducted. The basic configuration of an organic EL element is one in which a layer containing a light-emitting organic compound (also referred to as an EL layer) is sandwiched between a pair of electrodes. By applying a voltage to this element, light emission from the light-emitting organic compound can be obtained.

[0003] Since an organic EL element can be formed in a film shape, a large-area element can be easily formed, and it has high utility value as a surface light source applicable to lighting and the like.

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

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] A flash is mounted on the camera so that a photo can be taken even in a dark place.

[0007] In addition, in order to make the camera easily portable, miniaturization and weight reduction of the camera are required.

[0008] However, when the flash is made smaller, its light-emitting part approaches a linear or dot shape. Since light travels straight from the light source, the shadow projected by an object becomes clearer as the light source becomes smaller. Thus, for example, when photographing a person's face in a dark place using a flash, the shadow of the nose may be projected onto the cheek.

[0009] In addition, when the flash emits light that is stronger than necessary, parts that originally have different brightness levels may become all white in the photograph (so-called white blooming). On the other hand, when the light emission of the flash is too weak, dark parts may become all black in the photograph (so-called black crush). Therefore, there is a need for a flash that can adjust the light amount according to the environment and the situation of the subject.

[0010] For example, a light-emitting diode using an inorganic material can adjust the light amount, but it is a point light source. When emitting the same amount of light, a point light source needs to increase the light amount per unit area or extend the light emission time compared to an area light source or a line light source. Since the light-emitting diode emits light with heat generation, when emitting light with a large current or for a long time, the amount of heat generated by the light-emitting diode increases, and there is a risk of a decrease in lifespan or destruction of the element. Even for a high-brightness light-emitting diode, from the perspective of reliability, it is difficult to pass a current of 1.0 A or more, and further 1.5 A or more.

[0011] Therefore, one aspect of the present invention aims to provide a light-emitting device capable of adjusting the light amount. Or, one aspect of the present invention aims to provide a highly reliable light-emitting device. Or, one aspect of the present invention aims to provide a light-emitting device with low power consumption. Or, one aspect of the present invention aims to provide a light-emitting device that is less likely to produce shadows. Or, one aspect of the present invention aims to miniaturize and reduce the weight of the light-emitting device.

[0012] Note that one aspect of the present invention does not necessarily need to solve all of these problems.

Means for Solving the Problems

[0013] The light-emitting device according to one aspect of the present invention includes a constant-current power supply that can supply a control signal and a control pulse signal and supply a constant-current pulse, a control device that can supply a control signal, a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch, and a light-emitting panel to which the constant-current pulse is supplied. The control signal is a signal for controlling the magnitude of the constant-current pulse. The light-emitting panel has light-emitting elements, and the current density of the light-emitting elements is 10 mA / cm or more and 1000 mA / cm or less. In the above light-emitting device, for example, the drive circuit may supply a control pulse signal so that the constant-current power supply supplies a constant current having a half-value width of 1 millisecond or more and 1000 milliseconds or less. The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. 2 or more 2 and 1000 mA / cm or less.

[0014] In the above light-emitting device, for example, the drive circuit may supply a control pulse signal so that the constant-current power supply supplies a constant current having a half-value width of 1 millisecond or more and 1000 milliseconds or less. In the above light-emitting device, for example, the drive circuit may supply a control pulse signal so that the constant-current power supply supplies a constant current having a half-value width of 1 millisecond or more and 1000 milliseconds or less.

[0015] The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. The light-emitting device according to one aspect of the present invention includes an open / close circuit that can supply a constant current and a control pulse signal and supply a constant-current pulse, a constant-current power supply that can supply a control signal and supply a constant current, a control device that can supply a control signal, and a drive circuit that includes a start switch and can supply a control pulse signal in accordance with the opening and closing operation of the start switch. and a light-emitting panel to which a constant-current pulse is supplied, wherein the control signal is a signal for controlling the magnitude of the constant-current pulse, the light-emitting panel has light-emitting elements, and the current density of the light-emitting elements is 10 mA / cm 2 or more and 1000 mA / cm 2 or less.

[0016] In the above light-emitting device, for example, the drive circuit may supply a control pulse signal so that the open / close circuit supplies a constant current having a half-value width of 1 millisecond or more and 1000 milliseconds or less.

[0017] Further, the light-emitting device having each of the above configurations may further include a photosensor capable of supplying a first detection signal according to the detected amount of light. At this time, the control device includes an arithmetic unit, and the first detection signal is supplied. Then, the control device performs an operation using the first detection signal in the arithmetic unit, and supplies a control signal so that the constant-current power supply supplies a constant current according to the operation result.

[0018] Further, the light-emitting device having each of the above configurations may further include a distance sensor capable of supplying a second detection signal according to the detected distance. At this time, the control device includes an arithmetic unit, and the second detection signal is supplied. Then, the control device performs an operation using the second detection signal in the arithmetic unit, and supplies a control signal so that the constant-current power supply supplies a constant current according to the operation result.

[0019] Further, the light-emitting device having each of the above configurations may have both the above photosensor and distance sensor. At this time, the control device includes an arithmetic unit, and the first detection signal and the second detection signal are supplied. Then, the control device uses the first detection signal and the second detection signal in the arithmetic unit. The constant current power supply supplies a constant current according to the calculation result. do.

[0020] In the light-emitting device having the above-mentioned configuration, the light-emitting panel includes a support substrate and a light-emitting element on the support substrate. The light emitting element has a first electrode located closer to the support substrate than the second electrode, and There may be an overlying second electrode and an EL layer between the first and second electrodes. In this case, the support substrate may be flexible, and the light-emitting panel may have a curved surface.

[0021] In the light emitting device having the above configuration, the constant current power supply is an AC / DC converter that supplies a direct current. a DC / DC converter that is supplied with a DC current and can supply a constant current;

[0043]

[0022] In this specification, a device that converts AC to DC is called an AC / DC converter. A device that converts a DC current of one voltage into a DC current of a different voltage is called a DC-DC converter. In addition, a constant current power supply can be configured by using a current sensor and a DC / DC converter. Cut.

[0023] In addition, in each of the light emitting devices, a battery that supplies a first voltage and a power supply that supplies the first voltage are provided. A first DC-DC converter that provides a second voltage higher than the first voltage, and a A capacitor is supplied with a current and a constant current is supplied from the capacitor. and a second DC-DC converter.

[0024] In addition, electronic devices such as cameras and digital still cameras equipped with the light emitting devices having the above configurations are also included in the present invention. This is one aspect of clarity. Effect of the Invention

[0025] According to one aspect of the present invention, a light-emitting device capable of adjusting the amount of light can be provided. Or, a light-emitting device with high reliability can be provided. Or, a light-emitting device with low power consumption can be provided. Or, a light-emitting device in which shadows are less likely to occur can be provided. Or, miniaturization and weight reduction of the light-emitting device can be achieved.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0027] Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and those skilled in the art can easily understand that the form and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the embodiments shown below. ​​It should not be construed as being limited to the described content. In the configuration of the invention described below , the same reference numerals are commonly used for the same parts or parts having similar functions between different drawings, and the repeated description thereof will be omitted.

[0028] (Embodiment 1) In this embodiment, the configuration of a light-emitting device according to one aspect of the present invention will be described with reference to FIGS. 1 and 2. explain.

[0029] A light-emitting device according to one aspect of the present invention can adjust the amount of light emitted by a light-emitting panel according to a control signal supplied by a control device. The amount of light may be manually adjusted by the user of the light-emitting device, or the brightness around the light-emitting device detected by a light sensor, or the distance to an object (such as a subject of a camera) detected by a distance sensor etc. The light-emitting device may be automatically adjusted according to the distance or the like. Further, in a control device capable of arithmetic processing, an arithmetic operation is performed using the information such as the brightness, the distance, or an image taken in advance and the amount of light may be adjusted based on the result of the arithmetic operation. ) or the like. device, and the amount of light may be adjusted based on the result of the operation.

[0030] A light-emitting device according to one aspect of the present invention has a light-emitting panel which is a surface light source. For example, when an organic EL element is used, an element with a small film thickness and a large area can be easily formed. When emitting the same amount of light , compared with a point light source or a line light source, the surface light source can reduce the amount of light per unit area or shorten the light emission time. In addition, since the light emission area is large, it is easy to dissipate heat. Therefore, deterioration due to local heat generation of the light-emitting panel can be suppressed. That is, the light-emitting device according to one aspect of the present invention has a wide range of adjustable light amounts and high reliability.

[0031] <Configuration Example 1> The light-emitting device 100 shown in FIG. 1(A) includes a light-emitting panel 120, a drive circuit 130, a constant-current power supply 1 ​​It includes a constant current power supply 140a and a control device 150. In the light-emitting device 100 shown in Fig. 1(A), DC An example of the change over time of the current supplied by the DC converter is shown in Fig. 1(D). For example, a current of 2 A can be supplied to the light-emitting panel 120 for 50 milliseconds.

[0032] The constant current power supply 140a is supplied with a control signal and a control pulse signal and can supply a constant current pulse. Also, the constant current pulse is supplied to the light-emitting panel 120.

[0033] The control device 150 can supply a control signal. The control signal is a signal for controlling the magnitude of the constant current pulse. By changing the magnitude of the constant current pulse, the light quantity of the light-emitting panel 120 can be adjusted. For example, when the user of the light-emitting device selects a desired light quantity and a signal corresponding to the selection is supplied to the control device 1

[0034] 50, the control device 150 may supply a control signal corresponding to the signal. Also, when detection signals from various sensors are supplied to the control device 150, the control device 150 may supply a control signal corresponding to the detection signal. Further, when the control device 150 has an arithmetic unit, the control device 150 may perform an operation using the signal supplied to the control device 150 and supply a control signal corresponding to the operation result. The drive circuit 130 has a start switch 132 and can supply a control pulse signal. Here, the drive circuit 130 outputs a control pulse signal in accordance with the opening and closing operation of the start switch 132. For example, the control pulse signal is output so that the constant current power supply 140a supplies a constant current with a half-value width of 1 millisecond or more and 1000 milliseconds or less. The constant current power supply 140a is a drive

[0035] circuit 130, and the start switch 132 is turned on to start the supply of the constant current pulse to the light-emitting panel 120. Here, the drive circuit 130 outputs a control pulse signal in accordance with the opening and closing operation of the start switch 132. For example, the control pulse signal is output so that the constant current power supply 140a supplies a constant current with a half-value width of 1 millisecond or more and 1000 milliseconds or less. The constant current power supply 140a is a drive circuit 130, and the start switch 132 is turned on to start the supply of the constant current pulse to the light-emitting panel 120. circuit 130, and the start switch 132 is turned on to start the supply of the constant current pulse to the light-emitting panel 120. The constant current power supply 140a supplies a constant current to the light-emitting panel 120 in accordance with the control pulse signal output by the drive ​Since the control pulse signal is supplied from the circuit 130, a pulsed constant current can be supplied to the light-emitting panel 120 thereby.

[0036] 《Light-emitting panel》 The light-emitting panel 120 is a surface light source and includes a support substrate and light-emitting elements on the support substrate. The number of light-emitting elements may be one or plural. The magnitude of the constant current pulses supplied to the plurality of light-emitting elements may be controlled by one control signal or may be independently controlled by a plurality of control signals. respectively.

[0037] As the light-emitting element, for example, an organic EL element can be used. The organic EL element has a first electrode on the support substrate side, a second electrode overlapping the first electrode, and an EL layer between the first electrode and the second electrode. Note that the configuration of the light-emitting panel 120 will be described in detail in Embodiment 2, and the configuration of the organic EL element will be described in detail in Embodiment 3.

[0038] The area of the light-emitting portion of the light-emitting panel 120 is 0.5 cm 2 or more and 1 m 2 or less, preferably 5 c m 2 or more and 200 cm 2 or less, more preferably 15 cm 2 or more and 100 cm 2 or less.

[0039] The light-emitting panel 120 has, for example, a current density of the light-emitting element of 10 mA / cm 2 or more and 1000 mA / cm 2 or less, preferably 10 mA / cm 2 or more and 1500 mA / cm 2 or less, more preferably 10 mA / cm 2 or more and 1700 mA / cm 2 less than, even more preferably 1 mA / cm 2 Above 2000 mA / cm 2 The amount of light can be adjusted within the following range.

[0040] In addition, in the light-emitting panel 120, when an organic EL element is used, the light-emitting area of the light-emitting panel 120 can be easily increased, and the amount of light per unit area can be reduced. As a result of this, the amount of heat generated per unit area can be reduced. Therefore, compared with the case of using a light-emitting diode or the like using an inorganic material, deterioration of the light-emitting panel is less, and a highly reliable light-emitting device can be provided.

[0041] When an organic EL element is used, the light-emitting panel 120 can be made thinner and lighter than in the case of using a conventional xenon lamp or the like. In addition, since heat generation accompanying light emission is dispersed over a wide area of the light-emitting panel 120, heat is dissipated efficiently. As a result, heat accumulation in the light-emitting panel 120 is suppressed, and deterioration of the light-emitting panel 120 is suppressed.

[0042] In addition, since the light-emitting panel 120 is a surface light source, when the light-emitting device according to one aspect of the present invention is used as a camera flash , it is less likely to cause a shadow on the subject.

[0043] By selecting and using a light-emitting organic compound, the light-emitting panel 120 can be configured to emit white light. For example, a plurality of light-emitting organic compounds that emit light of colors having a complementary color relationship with each other can be used. Alternatively, three types of light-emitting organic compounds that emit light of red, green, and blue can be used. In addition, various emission spectra can be selected from various organic compounds and used. As a result, a light-emitting device excellent in white balance can be obtained.

[0044] ​​​ When a light-emitting organic compound is used, a wider emission spectrum can be obtained compared to a light-emitting diode using an inorganic material. Light having a wide emission spectrum is close to natural light and is suitable for photographing shadows.

[0045] In addition, the light-emitting panel 120 may have a plurality of light-emitting elements exhibiting different colors. By making the color and color temperature of the camera flash variable, the reproducibility of the subject, environment, atmosphere, etc. when taking a photograph can be enhanced. Also, the light-emitting device may have a plurality of light-emitting panels, and each light-emitting panel may have a configuration in which different colors are exhibited.

[0046] In addition, a flexible light-emitting panel manufactured using a flexible material for a support substrate or the like can be arranged along a housing having a curved surface. Thereby, the light-emitting device can be arranged without impairing the design used for the housing. For example, a flash can be arranged along a housing having a curved surface of a camera.

[0047] 《Control Device》 When the control device 150 has an arithmetic unit, an operation can be performed using the signal supplied to the control device 150. Examples of the signal supplied to the control device 150 include detection signals supplied from various sensors such as a light sensor and a distance sensor, signals obtained by amplifying the detection signals via an amplifier, and signals obtained by converting the detection signals or the amplified signals from analog signals to digital signals via a converter. The control device 150 may have, for example, a processor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), and a memory such as a RAM and a ROM for storing an arithmetic program. ​

[0048] Constant Current Power Supply The constant current power supply 140a includes an AC-DC converter that supplies a direct current, and a DC-DC converter to which the direct current is supplied. The timing at which the DC-DC converter supplies a constant current is controlled using a control pulse signal. Thereby, the waveform of the constant current pulse can be adjusted. The timing at which the DC-DC converter supplies a constant current is controlled using a control pulse signal. Thereby, the waveform of the constant current pulse can be adjusted. The timing at which the DC-DC converter supplies a constant current is controlled using a control pulse signal. Thereby, the waveform of the constant current pulse can be adjusted. The timing at which the DC-DC converter supplies a constant current is controlled using a control pulse signal. Thereby, the waveform of the constant current pulse can be adjusted.

[0049] Drive Circuit The drive circuit 130 supplies a control pulse signal having a predetermined width. The predetermined width is, for example, 1 millisecond or more and 1000 milliseconds or less, preferably 10 milliseconds or more and 100 milliseconds or less. The drive circuit 130 supplies a control pulse signal having a predetermined width. The predetermined width is, for example, 1 millisecond or more and 1000 milliseconds or less, preferably 10 milliseconds or more and 100 milliseconds or less.

[0050] For example, the drive circuit 130 can be configured using a start switch 132, a latch circuit, and a monostable multivibrator.

[0051] Specifically, a high or low signal is supplied to the latch circuit using the start switch 132, the latch circuit supplies a trigger signal, and the monostable multivibrator to which the trigger signal is supplied supplies a rectangular wave having a predetermined width as the control pulse signal. Specifically, a high or low signal is supplied to the latch circuit using the start switch 132, the latch circuit supplies a trigger signal, and the monostable multivibrator to which the trigger signal is supplied supplies a rectangular wave having a predetermined width as the control pulse signal. Specifically, a high or low signal is supplied to the latch circuit using the start switch 132, the latch circuit supplies a trigger signal, and the monostable multivibrator to which the trigger signal is supplied supplies a rectangular wave having a predetermined width as the control pulse signal.

[0052] In Configuration Example 1, a configuration is shown in which the control pulse signal is supplied to the constant current power supply 140a and the constant current power supply 140a is controlled using the control pulse signal. However, as in Configuration Example 2 described later, the control pulse signal may be supplied to the switching circuit 110. In Configuration Example 1, a configuration is shown in which the control pulse signal is supplied to the constant current power supply 140a and the constant current power supply 140a is controlled using the control pulse signal. However, as in Configuration Example 2 described later, the control pulse signal may be supplied to the switching circuit 110. In Configuration Example 1, a configuration is shown in which the control pulse signal is supplied to the constant current power supply 140a and the constant current power supply 140a is controlled using the control pulse signal. However, as in Configuration Example 2 described later, the control pulse signal may be supplied to the switching circuit 110.

[0053] <Configuration Example 2> The light-emitting device 101 shown in FIG. 1(B) includes a switching circuit 110, a light-emitting panel 120, a drive circuit 130, a constant current power supply 140a, a control device 150, and a photosensor 160. The light-emitting device 101 shown in FIG. 1(B) includes a switching circuit 110, a light-emitting panel 120, a drive circuit 130, a constant current power supply 140a, a control device 150, and a photosensor 160.

[0054] The closed-loop circuit 110 is supplied with a constant current and a control pulse signal and can supply a constant-current pulse. The constant-current power supply 140a can supply a constant current when supplied with a control signal. Also, the constant-current pulse is supplied to the light-emitting panel 120. The light-emitting panel 120 can adopt the same configuration as Configuration Example 1.

[0055] The optical sensor 160 can supply a detection signal to the control device 150 according to the detected light quantity. The control device 150 has an arithmetic unit, and the arithmetic unit performs an operation using the detection signal. The control device 150 supplies a control signal to the constant-current power supply 140a so that the constant-current power supply 140a supplies a constant current according to the operation result. Since the constant-current power supply 140a is supplied with a control signal from the control device 150, the constant current adjusted according to the light quantity detected by the optical sensor 160 can be supplied to the light-emitting panel 120.

[0056] The drive circuit 130 has a start switch 132 and can supply a control pulse signal. Here, the drive circuit 130 outputs a control pulse signal along with the opening / closing operation of the start switch 132. For example, the control pulse signal is output so that the closed-loop circuit 110 supplies a constant current with a half-value width of 1 millisecond or more and 1000 milliseconds or less. Since the closed-loop circuit 110 is supplied with a control pulse signal from the drive circuit 130, a pulsed constant current can be supplied to the light-emitting panel 120.

[0057] That is, in the light-emitting device 101, the light quantity emitted by the light-emitting panel 120 can be adjusted according to the light quantity detected by the optical sensor 160. For example, the ambient brightness is detected by the optical sensor 160. ​​​​​Then, by performing calculations with the control device 150, the current supplied to the light-emitting panel 120 can be adjusted so that the light-emitting panel emits an optimal amount of light.

[0058] For example, when the light-emitting device 101 is used as a camera flash, the more light the photosensor 160 detects (the brighter the surroundings of the subject), the less light is emitted, and it may be controlled accordingly. This can suppress overexposure and underexposure in the photo.

[0059] Also, for example, when the light-emitting device 101 is used as a bicycle or car light, it is controlled to emit light when the amount of light detected by the photosensor 160 falls below a certain level, and further, the less light is detected (the darker the surroundings and the easier it is to recognize the emission of the light-emitting device 101), the less light is emitted, and it may be controlled accordingly. This can prevent the emission of unnecessary light, thereby achieving power saving and extended lifespan of the light-emitting device.

[0060] 《Photosensor》 The photosensor 160 has a photoelectric conversion element such as a photodiode. The photosensor 160 supplies a detection signal corresponding to the amount of received light to the control device 150.

[0061] 《Open / Close Circuit》 While a constant current and a control pulse signal are being supplied, the open / close circuit 110 supplies a constant current pulse to the light-emitting panel 120.

[0062] For example, the open / close circuit 110 may have a power transistor or a power FET. Specifically, a control pulse signal is supplied to the gate of the power transistor, a constant current is supplied to the first electrode, the light-emitting panel 120 is electrically connected to the second electrode, and the open / close circuit 110 can be configured. ​​​​​​​​​​​​

[0063] In the light-emitting device 101 shown in FIG. 1(B), an example of the constant current supplied by the DCDC converter is shown in FIG. 1(C). Also, an example of the change over time of the current supplied by the switching circuit 110 is shown in FIG. 1(D). For example, a current of 2 A can be supplied to the light-emitting panel 120 for 50 milliseconds .

[0064] <Configuration Example 3> The light-emitting device 102 shown in FIG. 2(A) differs from the light-emitting device 101 shown in FIG. 1(B) in that it has a configuration of a constant-current power supply and includes a distance sensor 162 and a counter circuit 155. Since other configurations are the same as those of the light-emitting device 101, the description of the above Configuration Example 2 shall be referred to . .

[0065] 《Distance Sensor》 The distance sensor 162 supplies a detection signal corresponding to the measured distance to the control device 150. Various sensors such as an ultrasonic distance sensor and a laser distance sensor can be used for the distance sensor 162 . .

[0066] The control device 150 performs calculations using the detection signal from the optical sensor and the detection signal from the distance sensor. Then, a control signal can be supplied to the constant-current power supply 140b so that the constant-current power supply 140b supplies a constant current according to the calculation result. Since the control signal is supplied to the constant-current power supply 140b from the control device 150, a constant current adjusted according to the amount of light detected by the optical sensor 160 and the distance measured by the distance sensor 162 can be supplied to the switching circuit 110 . . . .

[0067] That is, in the light-emitting device 102, the amount of light emitted by the light-emitting panel 120 can be adjusted according to the amount of light detected by the optical sensor 160 and the distance measured by the distance sensor 162. For example, the emission . When the optical device 102 is used as the flash of a camera, the brightness around the subject is detected by the optical sensor 160, the distance from the subject to the camera is detected by the distance sensor 162, and the control device 1 50 performs calculations to supply the light emitting panel 120 with a current so that the light emitting panel emits an optimal amount of light. This can suppress overexposure and underexposure in the photograph. In addition, since it is possible to prevent the emission of unnecessary light, it is possible to achieve power saving and extended life of the light emitting device.

[0068] <<Modification Example of Constant Current Power Supply>> The constant current power supply 140b includes a battery that supplies a first voltage, a first DCDC converter that supplies a second voltage higher than the first voltage when the first voltage is supplied, a capacitor to which the second voltage is supplied, and a second DCDC converter that is supplied with charge from the capacitor. The first DCDC converter boosts the voltage of the battery (first voltage) to the second voltage and supplies it.

[0069] The capacitor is charged with the second voltage.

[0070] The second DCDC converter is supplied with the charge stored in the capacitor and supplies a constant current.

[0071] According to this configuration, the second DCDC converter can supply a constant current while the capacitor supplies charge to the second DCDC converter. Note that when the charge stored in the capacitor falls below a predetermined amount, the second DCDC converter cannot supply a constant current.

[0072] An example of the change over time of the current supplied by the constant current power supply 140b is shown in FIG. 2(B). When the charge stored in the capacitor is below a predetermined amount, the second DCDC converter cannot supply a constant current.

[0073] An example of the change over time of the current supplied by the constant current power supply 140b is shown in Fig. 2(B).​​​​​​

[0074] The constant current power supply 140b can supply a constant current for a period longer than at least the width of the control pulse signal supplied by the drive circuit 130 (for example, 50 milliseconds). When current flows through the switching circuit 110, the charge stored in the capacitor is consumed, and eventually, the constant current power supply 140b can no longer supply a constant current. As a result, a non-rectangular wave current flows through the light-emitting panel 120, causing the light-emitting panel 120 to emit light at a brightness lower than a predetermined brightness, and power is wasted unnecessarily. The switching circuit 110 can stop supplying current after supplying current for a predetermined time so that power is not wasted in this way. An example of the change in the current supplied by the switching circuit 110 with respect to time is shown in FIG. 2(C).

[0075] In this way, the constant current power supply 140b can supply a constant current using a battery. Thereby, a light-emitting device 102 that is easy to carry can be provided.

[0076] 《Counter Circuit》 The counter circuit 155 accumulates the number of times the drive circuit 130 supplies a control pulse signal. Thereby, the number of times the light-emitting panel 120 emits light can be known.

[0077] There are cases where the brightness of the light-emitting panel 120 decreases depending on the number of times the light-emitting panel 120 emits light.

[0078] The number of times accumulated in the counter circuit 155 can be fed back to the drive circuit 130 to increase the width of the control pulse signal. Thereby, the light-emitting time of the light-emitting panel 120 can be increased to compensate for the reduced brightness of the light-emitting panel 120.

[0079] Alternatively, the number of times integrated in the counter circuit 155 may be fed back to the constant current power supply 140b to increase the magnitude of the constant current supplied by the constant current power supply 140b. Thereby, the brightness of the lowered light emitting panel 120 can be compensated.

[0080] As described above, by applying one aspect of the present invention, a light emitting device capable of adjusting the amount of light by controlling the current value can be provided. In addition, since it has a light emitting panel as a surface light source, a light emitting device that is less likely to cause a shadow on the subject even when used as a flash can be provided. Further, compared with the case of using an inorganic material for a light emitting diode or the like, even when emitting a large amount of light, the deterioration of the light emitting panel is small, and a highly reliable light emitting device can be provided. In addition, compared with the case of using a xenon lamp or the like, miniaturization and thinning of the light emitting device can be achieved.

[0081] Note that the present embodiment can be appropriately combined with other embodiments described in this specification.

[0082] (Embodiment 2) In the present embodiment, the configuration of the light emitting panel that can be used in the light emitting device according to one aspect of the present invention will be described with reference to FIGS. 3 to 5.

[0083] <<Configuration Example 1 of Light Emitting Panel>> FIG. 3(A) is a plan view showing a light emitting panel according to one aspect of the present invention, and FIG. 3(B) is a cross-sectional view taken along the dashed line A - B in FIG. 3(A).

[0084] The light emitting panel shown in FIGS. 3(A) and 3(B) includes a light emitting element 403 in a space 415 surrounded by a support substrate 401, a sealing substrate 405, and a sealing material 407. The light emitting element 403 is a bottom emission It is an organic EL element with a bottom emission structure. Specifically, it transmits visible light on a support substrate 401. It has a first electrode 421, has an EL layer 423 on the first electrode 421, and has a second electrode 425 that reflects visible light.

[0085] The light-emitting element applied to one aspect of the present invention is not limited to the bottom emission structure. For example, it may be a top emission structure.

[0086] The first terminal 409a is electrically connected to the auxiliary wiring 417 and the first electrode 421. The first An insulating layer 419 is provided in a region overlapping the auxiliary wiring 417 on the electrode 421. The first terminal 409a and the second electrode 425 are electrically insulated by the insulating layer 419 from each other. The second terminal 409b is electrically connected to the second electrode 425. In this embodiment Although the configuration in which the first electrode 421 is formed on the auxiliary wiring 417 is shown, the first electrode 421 may be formed on the auxiliary wiring 417.

[0087] It is preferable to have a light extraction structure 411a at the interface between the support substrate 401 and the atmosphere. By providing the light extraction structure 411a at the interface between the atmosphere and the support substrate 401, light that cannot be extracted into the atmosphere due to the effect of total reflection can be reduced, and the light extraction efficiency of the light-emitting panel can be improved.

[0088] Also, it is preferable to have a light extraction structure 411b between the light-emitting element 403 and the support substrate 401. When the light extraction structure 411b has irregularities, it is preferable to provide a planarization layer 413 between the light extraction structure 411b and the first electrode 421. Thereby, the first electrode 421 can be made into a flat film, and the irregularities of the first electrode 421 in the EL layer 423 can be eliminated. ​The generation of leakage current caused thereby can be suppressed. Further, since the light extraction structure 411b is provided at the interface between the planarization layer 413 and the support substrate 4 01, light that cannot be extracted into the atmosphere due to the influence of total reflection can be reduced, and the light extraction efficiency of the light-emitting panel can be improved.

[0089] As the material of the light extraction structure 411a and the light extraction structure 411b, for example, resin can be used. Further, as the light extraction structure 411a and the light extraction structure 411b, a hemispherical lens, a microlens array, a film with an uneven structure, a light diffusion film, etc. can also be used. For example, the above lens or film is placed on the support substrate 401, and the support substrate 401 or an adhesive having a refractive index similar to that of the lens or film is used for adhesion to form the light extraction structure 411a and the light extraction structure 411b.

[0090] The planarization layer 413 is flatter on the surface in contact with the first electrode 421 than on the surface in contact with the light extraction structure 411b. As the material of the planarization layer 413, a material having light transmittance and a high refractive index (for example, a liquid substance such as a refractive liquid, glass, resin, etc.) can be used.

[0091] Note that the light-emitting panel according to one aspect of the present invention can also be configured without a light extraction structure. In that case, it is possible and preferable to use the second electrode that reflects visible light as a mirror.

[0092] <<Configuration Example 2 of Light-Emitting Panel>> FIG. 4(A) is a plan view showing a light-emitting panel according to one aspect of the present invention, and FIGS. 5(A) and 5(B) are cross-sectional views obtained by cutting FIG. 4(A) along the dashed-dotted line X1 - Y1, respectively.

[0093] ​​​​​In the light-emitting panel shown in FIG. 5A, 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. , and electrically connects to the first electrode 1201. A part of the auxiliary wiring 1206 is exposed and serves as a terminal. The end of the first electrode 1201 and the end of the conductive layer 1210 are separated by a partition wall 1205. In addition, a partition wall 1205 covers the auxiliary wiring 1206 through the first electrode 1201. The light emitting element 1250 includes a supporting substrate 1220, a sealing substrate 1228, and an encapsulating layer 1229. The light extraction structure 120 is formed on the surface of the support substrate 1220. The support substrate 1220 and the sealing substrate 1228 are bonded to each other. By using the above, a flexible light-emitting panel can be realized.

[0094] 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. .

[0095] In the light-emitting panel shown in FIG. 5B, 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.

[0096] 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. There are a method and a second method in which a light-emitting element is formed on a substrate having high heat resistance different from a flexible substrate (hereinafter referred to as a production substrate), and after that, the production substrate and the light-emitting element are peeled off, and the light-emitting element is transferred to the flexible substrate. There is a second method in which a light-emitting element is formed on a substrate having high heat resistance different from a flexible substrate (hereinafter referred to as a production substrate), and after that, the production substrate and the light-emitting element are peeled off, and the light-emitting element is transferred to the flexible substrate. There is a second method in which a light-emitting element is formed on a substrate having high heat resistance different from a flexible substrate (hereinafter referred to as a production substrate), and after that, the production substrate and the light-emitting element are peeled off, and the light-emitting element is transferred to the flexible substrate.

[0097] For example, when using a substrate having heat resistance against the temperature applied in the manufacturing process of the light-emitting element, such as a glass substrate having a thickness thin enough to be flexible, it is preferable to use the first method because the process is simplified. For example, when using a substrate having heat resistance against the temperature applied in the manufacturing process of the light-emitting element, such as a glass substrate having a thickness thin enough to be flexible, it is preferable to use the first method because the process is simplified. For example, when using a substrate having heat resistance against the temperature applied in the manufacturing process of the light-emitting element, such as a glass substrate having a thickness thin enough to be flexible, it is preferable to use the first method because the process is simplified.

[0098] Also, by applying the second method, a low-permeability insulating film or the like formed by applying high temperature on the production substrate can be transferred to the flexible substrate. Therefore, even when using an organic resin or the like having high water permeability and low heat resistance as the material of the flexible substrate, a light-emitting panel having flexibility and high reliability can be manufactured. Also, by applying the second method, a low-permeability insulating film or the like formed by applying high temperature on the production substrate can be transferred to the flexible substrate. Therefore, even when using an organic resin or the like having high water permeability and low heat resistance as the material of the flexible substrate, a light-emitting panel having flexibility and high reliability can be manufactured. Also, by applying the second method, a low-permeability insulating film or the like formed by applying high temperature on the production substrate can be transferred to the flexible substrate. Therefore, even when using an organic resin or the like having high water permeability and low heat resistance as the material of the flexible substrate, a light-emitting panel having flexibility and high reliability can be manufactured. Also, by applying the second method, a low-permeability insulating film or the like formed by applying high temperature on the production substrate can be transferred to the flexible substrate. Therefore, even when using an organic resin or the like having high water permeability and low heat resistance as the material of the flexible substrate, a light-emitting panel having flexibility and high reliability can be manufactured.

[0099] <<Configuration Example 3 of Light-Emitting Panel>> FIG. 4(B) is a plan view showing a light-emitting panel according to an aspect of the present invention, FIGS. 6(A) and (B) are examples of cross-sectional views obtained by cutting FIG. 4(B) along the chain double-dashed line X2 - Y2, and FIG. 6(C) is a cross-sectional view obtained by cutting FIG. 4(B) along the chain double-dashed line X3 - Y3. FIG. 4(B) is a plan view showing a light-emitting panel according to an aspect of the present invention, FIGS. 6(A) and (B) are examples of cross-sectional views obtained by cutting FIG. 4(B) along the chain double-dashed line X2 - Y2, and FIG. 6(C) is a cross-sectional view obtained by cutting FIG. 4(B) along the chain double-dashed line X3 - Y3. FIG. 4(B) is a plan view showing a light-emitting panel according to an aspect of the present invention, FIGS. 6(A) and (B) are examples of cross-sectional views obtained by cutting FIG. 4(B) along the chain double-dashed line X2 - Y2, and FIG. 6(C) is a cross-sectional view obtained by cutting FIG. 4(B) along the chain double-dashed line X3 - Y3.

[0100] The light-emitting panel shown in FIGS. 6(A) to (C) is different from Configuration Example 2 of the light-emitting panel in that it has an opening in part. Here, only the differences will be described in detail, and for the common points, the description of Configuration Example 2 of the light-emitting panel will be referred to. The light-emitting panel shown in FIGS. 6(A) to (C) is different from Configuration Example 2 of the light-emitting panel in that it has an opening in part. Here, only the differences will be described in detail, and for the common points, the description of Configuration Example 2 of the light-emitting panel will be referred to. The light-emitting panel shown in FIGS. 6(A) to (C) is different from Configuration Example 2 of the light-emitting panel in that it has an opening in part. Here, only the differences will be described in detail, and for the common points, the description of Configuration Example 2 of the light-emitting panel will be referred to.

[0101] As shown in FIGS. 6(A) and (B), the light-emitting panel preferably has a sealing material 1226 so that the electrodes and the EL layer are not exposed at the opening. Specifically, a part of the light-emitting panel As shown in FIGS. 6(A) and (B), the light-emitting panel preferably has a sealing material 1226 so that the electrodes and the EL layer are not exposed at the opening. Specifically, a part of the light-emitting panel After opening, a sealing material 1226 may be formed so as to cover at least the exposed electrode and the EL layer. For the sealing material 1226, the same material as that of the sealing material 1227 can be used, and it may be the same material or different materials.

[0102] FIG. 6(A) shows an example in the case where an opening is made at a position where the partition wall 1205 is not formed, and FIG. 6 (B) shows an example in the case where an opening is made at a position where the partition wall 1205 is formed.

[0103] By manufacturing such a light-emitting panel and arranging the lens of the camera so as to overlap the opening, a light-emitting part can be arranged around the lens of the camera. Then, the light-emitting part can be used as a flash of the camera.

[0104] Note that a light extraction structure may be provided on the surface of the substrate.

[0105] 《Materials of the Light-Emitting Panel》 An example of a material that can be used for the light-emitting panel according to one aspect of the present invention will be described.

[0106] [Substrate] For the substrate on the side where the light from the light-emitting element is extracted, a material that transmits the light is used. For example, materials such as glass , quartz, ceramic, sapphire, and organic resin can be used.

[0107] By using a substrate with a thin film thickness, the weight reduction and thinning of the light-emitting panel can be achieved. Further more, by using a substrate with a thickness that has flexibility, a flexible light-emitting panel can be realized . Also, when a flexible light-emitting panel is not used, it can be folded and stored . As a result, it can be replaced with a board reflector in a photo studio Furthermore, it can be used as a lighting device that emits flash light over a large area. Alternatively, it is possible to provide a lighting device that can be folded. It is possible to provide a lighting device that can be folded.

[0108] As the glass, for example, alkali-free glass, barium borosilicate glass, aluminoborosilicate glass, etc. can be used. It is possible to use etc.

[0109] As the material having flexibility and transparency to visible light, for example, glass having a thickness with a certain degree of flexibility, polyethylene terephthalate (PET), polyethylene naphthalate ( PEN), etc. polyester resins, polyacrylonitrile resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES ) resin, polyamide resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyvinyl chloride resin, etc. can be mentioned. In particular, it is preferable to use a material with a low coefficient of thermal expansion. For example, polyamideimide resin, polyimide resin, PET, etc. can be preferably used . In addition, a substrate impregnated with an organic resin in glass fibers or a substrate in which an inorganic filler is mixed with an organic resin to lower the coefficient of thermal expansion can also be used. A substrate using such a material has a light weight, so the light-emitting panel using the substrate can also be made lightweight. Since it is light in weight, the light-emitting panel using the substrate can also be made lightweight.

[0110] In addition, since the substrate on the side where light is not extracted does not have to have translucency, in addition to the substrates listed above, a metal substrate using a metal material or an alloy material can also be used. Metal materials and alloy materials have high thermal conductivity and can easily conduct heat throughout the substrate. Therefore, local temperature rise of the light-emitting panel can be suppressed, which is preferable. In order to obtain flexibility and bendability, a metal substrate The thickness of the plate 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

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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. It is possible. The thickness of the glass layer is 20 μm or more and 200 μm or less, preferably 25 μm or more and 100 μm or less. The glass layer with such a thickness can simultaneously achieve high barrier properties against water and oxygen and flexibility. Further, the thickness of the organic resin layer is 10 μm or more and 200 μm or less, preferably 20 μm or more and 50 μm or less. By providing such an organic resin layer outside the glass layer, cracks and fractures in the glass layer can be suppressed, and the mechanical strength can be improved. By applying such a composite material of a glass material and an organic resin to a substrate, a highly reliable flexible light-emitting panel can be obtained.

[0116] [Insulating film] An insulating film may be formed between the support substrate and the light-emitting element. As the insulating film, an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film can be used. In particular, in order to suppress the intrusion of moisture and the like into the light-emitting element, it is preferable to use an insulating film with low water permeability such as a silicon oxide film, a silicon nitride film, or an aluminum oxide film. For the same purpose and using the same material, an insulating film covering the light-emitting element may be provided.

[0117] [Partition wall] As the partition wall, an organic resin or an inorganic insulating material can be used. As the organic resin, for example, a polyimide resin, a polyamide resin, an acrylic resin, a siloxane resin, an epoxy resin, or a phenolic resin can be used. As the inorganic insulating material, silicon oxide, silicon oxynitride, or the like can be used. Since the production of the partition wall becomes easy, it is particularly preferable to use a photosensitive resin.

[0118] ​​​​​The method for forming the partition is not particularly limited. For example, a photolithography method, a sputtering method, a vapor deposition method, a droplet ejection method (such as an inkjet method), a printing method (such as screen printing, offset printing), etc. may be used.

[0119] [Auxiliary wiring] The auxiliary wiring does not necessarily have to be provided, but it is preferably provided in order to suppress the voltage drop caused by the resistance of the electrode.

[0120] The material of the auxiliary wiring is selected from copper (Cu), titanium (Ti), tantalum (Ta), tungsten (W ), molybdenum (Mo), chromium (Cr), neodymium (Nd), scandium (Sc), nickel (Ni), or an alloy material mainly composed of these, and is formed as a single layer or by lamination. Aluminum can also be used as the material of the auxiliary wiring. When aluminum is used, there is a risk of corrosion if it is provided in direct contact with the transparent oxide conductive material. Therefore, it is preferable to use aluminum in a laminated structure for the auxiliary wiring so that corrosion does not occur, and not to contact with ITO or the like. The film thickness of the auxiliary wiring can be 0.1 μm or more and 3 μm or less, and preferably 0.1 μm or more and 0.5 μm or less.

[0121] [Sealing material] The method for sealing the light-emitting panel is not limited, and for example, it may be solid sealing or hollow sealing. For example, glass materials such as glass frit, curable resins that cure at room temperature such as two-component mixed resins, photocurable resins, thermosetting resins, and other resin materials can be used. The light-emitting panel may be filled with an inert gas such as nitrogen or argon, and PVC (poly vinyl chloride) resin, acrylic resin, polyimide resin, epoxy resin, silicone resin It may be filled with resins such as fats, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Further, a desiccant may be contained in the resin.

[0122] [Light extraction structure] As the light extraction structure, a hemispherical lens, a microlens array, a film with an uneven structure, a light diffusion film, etc. can be used. For example, the above lens or film is adhered onto a substrate using an adhesive or the like having a refractive index similar to that of the substrate or the lens or film, to form a light extraction structure.

[0123] Note that this embodiment can be appropriately combined with other embodiments shown in this specification.

[0124] (Embodiment 3) In this embodiment, a light-emitting element that can be used in a light-emitting device according to one aspect of the present invention will be described with reference to FIG. 7.

[0125] <<Configuration example of light-emitting element>> The light-emitting element shown in FIG. 7(A) has an EL layer 20 3 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 a cathode.

[0126] When a voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 201 and the second electrode 205, holes are injected into the EL layer 203 from the first electrode 201 side, and electrons are injected from the second electrode 205 side. The injected electrons and holes recombine in the EL layer 20 3, and the light-emitting substance contained in the EL layer 20

[0127] The EL layer 203 has at least a light-emitting layer 303 containing a light-emitting substance.

[0128] Further, as layers other than the light-emitting layer, the EL layer 203 may further have a layer containing a substance with high hole injection property, a substance with high hole transport property, a substance with high electron transport property, a substance with high electron injection property, or a bipolar substance (a substance with high electron transport property and high hole transport property), etc. The EL layer 203 can use either a low molecular weight compound or a high molecular weight compound, and may contain an inorganic compound.

[0129] The light-emitting device shown in Fig. 7(B) has an EL layer 20 3 between the first electrode 201 and the second electrode 205. In the EL layer 203, 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.

[0130] As in the light-emitting devices shown in Figs. 7(C) and 7(D), a plurality of EL layers may be laminated between the first electrode 201 and the second electrode 205. In this case, it is preferable to provide an intermediate layer 207 between the laminated EL layers. The intermediate layer 207 has at least a charge generation region.

[0131] For example, the light-emitting device shown in Fig. 7(C) has an intermediate layer 207 between the first EL layer 203a and the second EL layer 203b. Also, the light-emitting device shown in Fig. 7(D) has n EL layers (n is a natural number of 2 or more), and an intermediate layer 207 is provided between each EL layer.

[0132] The behavior of electrons and holes in the intermediate layer 207 provided between the EL layer 203(m) and the EL layer 203(m + 1) will be described. Between the first electrode 201 and the second electrode 205, a light-emitting element When a voltage higher than the threshold voltage of the child is applied, holes and electrons are generated in the intermediate layer 207, and the positive 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) provided on the first electrode 201 side. The holes injected into the EL layer 203(m + 1) recombine with the electrons injected from the second electrode 205 side, and the light-emitting substance contained in the EL layer 203( m + 1) emits light. In addition, the electrons injected into the EL layer 203(m) recombine with the holes injected from the first electrode 201 side, and the light-emitting substance contained in the EL layer 203(m) emits light. Therefore, the holes and electrons generated in the intermediate layer 207 reach light emission in different EL layers respectively. That is, the holes and electrons generated in the intermediate layer 207 reach light emission in different EL layers respectively. reach light emission.

[0133] In addition, when the same structure as the intermediate layer is formed between the EL layers by providing the EL layers in contact with each other , the EL layers can be provided in contact with each other without passing through the intermediate layer. For example, when a charge generation region is formed on one surface of the EL layer, an EL layer can be provided in contact with that surface.

[0134] In addition, by making the emission colors of the respective EL layers different, it is possible to obtain light emission of a desired color as the entire light-emitting element. For example, in a light-emitting element having two EL layers, by making the emission color of the first EL layer and the emission color of the second EL layer be in a complementary color relationship, it is also possible to obtain a light-emitting element that emits white light as the entire light-emitting element. The same applies to a light-emitting element having three or more EL layers. This is also the case for light-emitting elements having three or more EL layers.

[0135] 《Materials of the Light-Emitting Element》 The materials that can be used for each layer are exemplified below. Note that each layer is not limited to a single layer, and two or more layers may be stacked. That is, each layer is not limited to a single layer, and two or more layers may be stacked.

[0136] <Anode> The electrode (the first electrode 201) that functions as an anode can be formed using one or more kinds of conductive metals, alloys, conductive compounds, etc. In particular, it is preferable to use a material with a large work function (4.0 eV or more). For example, indium tin oxide (ITO: Indium Tin Oxide), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, indium oxide containing tungsten oxide and zinc oxide, graphene, gold, platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, or nitrides of metal materials (e.g., titanium nitride), etc. can be mentioned. When the anode is in contact with the charge generation region, various conductive materials can be used without considering the magnitude of the work function. For example, aluminum, silver, alloys containing aluminum, etc. can also be used. .

[0137] When the anode is in contact with the charge generation region, various conductive materials can be used without considering the magnitude of the work function. For example, aluminum, silver, alloys containing aluminum, etc. can also be used. For example, aluminum, silver, alloys containing aluminum, etc. can also be used.

[0138] <Cathode> The electrode (the second electrode 205) that functions as a cathode can be formed using one or more kinds of conductive metals, alloys, conductive compounds, etc. In particular, it is preferable to use a material with a small work function (3. 8 eV or less). For example, elements belonging to Group 1 or Group 2 of the periodic table (e.g., alkali metals such as lithium, cesium, etc., alkaline earth metals such as calcium, strontium, etc., magnesium, etc.), alloys containing these elements (e.g., Mg - Ag, Al - Li), rare earth metals such as europium, ytterbium, alloys containing these rare earth metals, aluminum, silver, etc. can be used.

[0139] ​​​​​When the cathode is in contact with the charge generation region, various conductive materials can be used without considering the work function. For example, indium tin oxide containing ITO, silicon, or silicon oxide can also be used.

[0140] The electrodes can be formed using, for example, vacuum evaporation or sputtering. Also, when using silver paste or the like, a coating method or an inkjet method can be used.

[0141] 〈Hole injection layer 301〉 The hole injection layer 301 is a layer containing a material with high hole injection properties.

[0142] Examples of materials with high hole injection properties include metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide, and phthalocyanine-based compounds such as phthalocyanine (abbreviation: H2Pc) and copper(II) phthalocyanine (abbreviation: CuPc) can be used.

[0143] In addition, polymer compounds such as poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenylamine) (abbreviation: PVTPA), and polymer compounds added with acids such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) can be used.

[0144] Also, the hole injection layer 301 can be used as the charge generation region. When the hole injection layer 301 in contact with the anode is the charge generation region, various conductive materials can be used for the anode without considering the work function.

[0145] 〈Hole transport layer 302〉 The hole transport layer 302 is a layer containing a substance with high hole transport property.

[0146] As the substance with high hole transport property, any substance with higher hole transport property than electron transport property is acceptable. In particular , 10 -6 cm 2 / Vs or higher hole mobility is preferred. For example, 4,4’-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NP B or α-NPD), 4-phenyl-4’-(9-phenylfluoren-9-yl)tri phenylamine (abbreviation: BPAFLP) and other aromatic amine compounds, 4,4’-di(N-ca rbazolyl)biphenyl (abbreviation: CBP), 9-[4-(10-phenyl-9-anthry l)phenyl]-9H-carbazole (abbreviation: CzPA), 9-phenyl-3-[4-( 10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA ) and other carbazole derivatives, 2-tert-butyl-9,10-di(2-naphthyl)an thracene (abbreviation: t-BuDNA), 9,10-di(2-naphthyl)anthracene (abbreviation : DNA), 9,10-diphenylanthracene (abbreviation: DPAnth) and other aromatic hydrocarbon compounds, polymer compounds such as PVK and PVTPA, and various compounds can be used.

[0147] 〈Light-emitting layer 303〉 The light-emitting layer 303 can use a fluorescent compound that emits fluorescence or a phosphorescent compound that emits phosphorescence.

[0148] Examples of the fluorescent compound that can be used in the light-emitting layer 303 include, for example, 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-carbazole-3-amine (abbreviation: 2PCAPA), rut henium, etc. can be mentioned.

[0149] In addition, as the phosphorescent compound that can be used in the light-emitting layer 303, for example, bis[2-( 4’,6’-difluorophenyl)pyridinato-N,C 2’ iridium(III) pic olinate (abbreviation: FIrpic), tris(2-phenylpyridinato-N,C 2’ ) iri dium(III) (abbreviation: Ir(ppy)3) (acetylacetonato)bis(3,5-di methyl-2-phenylpyrazinato)iridium(III) (abbreviation: Ir(mppr-Me )2(acac)), etc. of organometallic complexes can be mentioned.

[0150] Note that the light-emitting layer 303 may have a structure in which the above-described light-emitting organic compound (light-emitting substance, guest material) is dispersed in another substance (host material). As the host material, various materials can be used , and it is preferable to use a substance having a higher lowest unoccupied molecular orbital level (LUMO level) and a lower highest occupied molecular orbital level (HOMO level) than the guest material.

[0151] By adopting a structure in which the guest material is dispersed in the host material, crystallization of the light-emitting layer 303 can be suppressed. In addition, concentration quenching due to a high concentration of the guest material can be suppressed.

[0152] As the host material, the above-described substances having high hole-transporting properties (for example, aromatic amine compounds and carb azole derivatives) or substances having high electron-transporting properties described later (for example, quinoline skeletons or benzoqui Metal complexes having a norbornene skeleton, or those having an oxazole-based ligand or a thiazole-based ligand such as metal complexes) can be used. Specifically, tris(8-quinolinolato)aluminum (III) (abbreviation: Alq), bis(2-methyl-8-quinolinolato)(4-phenyl phenolato)aluminum(III) (abbreviation: BAlq) and other metal complexes, 3-(4- biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4- triazole (abbreviation: TAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP) and other heterocyclic compounds, condensed aromatic compounds such as CzPA, DNA, t-BuDNA, DPAnth, and aromatic amine compounds such as NPB can be used.

[0153] In addition, multiple types of host materials can be used. For example, a substance that suppresses crystallization such as rubrene can be further added to suppress crystallization. Also, NPB, or Alq or the like can be further added to more efficiently perform energy transfer to the guest material.

[0154] Moreover, by providing multiple light-emitting layers and making the emission colors of each layer different, overall light emission of a desired color can be obtained for the entire light-emitting device. For example, in a light-emitting device having two light-emitting layers, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer be in a complementary color relationship, it is also possible to obtain a light-emitting device that emits white light as a whole. The same applies to a light-emitting device having three or more light-emitting layers.

[0155] 〈Electron transport layer 304〉 The electron transport layer 304 is a layer containing a substance with high electron transport properties.

[0156] ​​​​​​​ 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.

[0157] 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.

[0158] <Electron injection layer 305> The electron injection layer 305 is a layer containing a substance with high electron injection properties.

[0159] 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. Potassium earth metals or their compounds can be used. Also, erbium fluoride and other The above-mentioned rare earth metal compound constituting the electron transport layer 304 can be used. It is also possible to use a material that

[0160] <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.

[0161] Examples of the organic compound with high hole transport property include, for example, those that can be used for the above-described hole transport layer. Examples of the organic compound with high electron transport property include, for example, those that can be used for the above-described electron transport layer. can be mentioned.

[0162] In addition, examples of the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, etc. can be mentioned. In addition, transition metal oxides can be mentioned. Also, oxides of metals belonging to Groups 4 to 8 in the periodic table of elements can be mentioned. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide are preferable because of their high electron accepting property. Among them, molybdenum oxide is particularly preferable because it is stable even in the air, has low hygroscopicity, and is easy to handle.

[0163] In addition, as the electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Group 13 in the periodic table of elements and its oxides and carbonates can be used. Specifically, lithium, cesium, magnesium, calcium, ytterbium, indium, lithium oxide, cesium carbonate, etc. are preferably used. In addition, an organic compound such as tetrathianaphthacene may be used as the electron donor.

[0164] Note that the layers constituting the above-described EL layer 203 and the intermediate layer 207 can be formed by methods such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, a coating method, etc.

[0165] ​​ In addition, this embodiment can be appropriately combined with other embodiments described in this specification. .

[0166] (Embodiment 4) In this embodiment, an electronic device using a light-emitting device according to an aspect of the present invention will be described with reference to FIGS. 8 and 9. using.

[0167] A light-emitting device according to an aspect of the present invention can be used for a flash of a camera such as a digital still camera, a camera provided in a mobile phone (also referred to as a mobile phone or a mobile phone device) having a photographing function, a mobile information terminal, etc. It can also be used for a flash of a camera or the like. Further, it can be used for illuminations such as bicycle and automobile lights, lighthouses, and decorative purposes. roads, etc. It can be used for illuminations such as roads.

[0168] FIG. 8(A) shows an example of a digital still camera. The digital still camera 7300 has a housing 7301, a lens 7304, a light-emitting device 7310, etc. The light-emitting device 7310 applies a light-emitting device according to an aspect of the present invention. The light-emitting portion 7303 of the light-emitting device 7310 is arranged so as to surround the lens 7304. Since the light-emitting device according to an aspect of the present invention has flexibility, it can be bent. In the digital still camera 7300, since the non-light-emitting portion 73 05 is bent along the shape of the housing 7301, the light-emitting portion 7303 can be widely arranged around the lens 7 304. Thereby, even when a person's face is shaded with a flash in a dark place, for example, the shadow of the nose can be made less likely to be projected onto the cheek. Note that a light-emitting element may be manufactured and provided in the non-light-emitting portion 7305 in the same process and used as an indicator indicating an operating state. 304. shadow, for example, the shadow of the nose can be made less likely to be projected onto the cheek. A light-emitting element may be manufactured and provided in the non-light-emitting portion 7305 in the same process and used as an indicator indicating an operating state. used.

[0169] Figures 8(B) and 8(C) show an example of a mobile phone. One side (the front side can also be said) of the mobile phone 7350 is shown in Figure 8(B), and the back side (the back side can also be said) of this side is shown in Figure 8(C). .

[0170] The mobile phone 7350 has a housing 7351, a display unit 7352, a lens 7354, a light-emitting device 73 60, etc. The light-emitting device 7360 applies the light-emitting device of one aspect of the present invention. The light-emitting device 7360 has a light-emitting part 7353 and a non-light-emitting part 7355, and the light-emitting part 7353 is arranged so as to surround the lens 7354. The light-emitting part 7353 may be designed to be used as a mirror when not emitting light. .

[0171] Figure 9(A) shows a modified example in which the light-emitting device 7360 of the mobile phone 7350 has two light-emitting panels 7353a, 7353b.

[0172] Figure 10 shows a block diagram of the light-emitting device 7360 in Figure 9(A). The light-emitting device 7360 has two light-emitting panels 7353a, 7353b, a drive circuit 730, two constant-current power supplies 740 a, 740b, and two control devices 750a, 750b.

[0173] Signals corresponding to the conditions selected by the user of the mobile phone 7350 and detection signals from various sensors are supplied to the two control devices 750a, 750b. The two control devices 750a, 7 50b supply control signals corresponding to the supplied signals respectively. .

[0174] The constant-current power supply 740a supplies a constant-current pulse corresponding to the control signal supplied from the control device 750a to the light-emitting panel 7353a. The constant-current power supply 740b supplies from the control device 750b A constant current pulse corresponding to the supplied control signal is supplied to the light emitting panel 7353b. Therefore, The light amounts of the two light emitting panels 7353a and 7353b are each independently adjusted. Thereby the light amount emitted by the light emitting device can be adjusted over a wider range, which is preferable.

[0175] Also, light emitting panels having different colors and color temperatures may be used. For example, when the color temperatures of the two light emitting panels are different, the light emitting device can emit light with an appropriate color temperature by adjusting the light amounts of the respective light emitting panels.

[0176] Also, the drive circuit 730 has a start switch 732. The two light emitting panels 7353 a and 7353b are each independently supplied with a control pulse signal from the drive circuit 730. Thus the drive circuit 730 may supply the same control pulse signal to the two light emitting panels 7353a and 7353b, or different control pulse signals may be supplied.

[0177] Note that the light emitting device 7360 may have two or more drive circuits. Also, the light emitting device 73 60 may have three or more light emitting panels. Also, a light emitting panel that cannot adjust the light amount and a light emitting panel that can adjust the light amount according to an aspect of the present invention may be combined. In the light emitting device 7360 having the configuration shown in FIG. 10, the light emitting panels 7353a and 7353b

[0178] can each be independently made to emit light. For example, when the light emission of only one light emitting panel is sufficient only one light emitting panel may be made to emit light, and both light emitting panels may be made to emit light only when a larger light amount is required. Thereby the power consumption of the light emitting device and the deterioration of the light emitting panel can be suppressed.

[0179] Figure 9(B) shows an example of a bicycle. Bicycle 7400 has a light 7405 . The light 7405 is applied with a light-emitting device according to an aspect of the present invention.

[0180] Figure 9(C) shows an example of an automobile. Automobile 7410 has a light 7415 . The light 7415 is applied with a light-emitting device according to an aspect of the present invention.

[0181] When the light-emitting device according to an aspect of the present invention is used in a bicycle or automobile light, for example, a light sensor is used to detect the ambient brightness. When the surroundings are bright enough, the light is not turned on. When the surroundings are sufficiently dark, the light is turned on and blinked. When the ambient brightness is insufficient but light can be detected , the light is turned on and blinked, and the light amount is increased, and other controls can be performed. Thus, since the light-emitting device according to an aspect of the present invention can emit light by adjusting to an appropriate optimal light amount, a power-saving light can be realized.

[0182] Note that this embodiment can be appropriately combined with other embodiments shown in this specification. .

Example

[0183] In this example, a light-emitting panel according to an aspect of the present invention will be described.

[0184] A plan view of the light-emitting panel manufactured in this example is shown in FIG. 4(A), and a cross-sectional view between the dashed-dotted lines X1 - Y1 in FIG. 4(A) is shown in FIG. 5(B). Note that in FIG. 4(A), a part of the configuration of the light-emitting panel is shown in an omitted manner.

[0185] As shown in FIG. 5(B), the light-emitting panel of this example has a support substrate 1 having a light extraction structure A light-emitting element 1250 is provided on 229 via an insulating film 1224. The insulating film 1224 has an auxiliary wiring 1206 provided thereon, which is electrically connected to the first electrode 1201. The auxiliary wiring 1206 is partially exposed and functions as a terminal. The ends of the first electrode 1201 and the conductive layer 1210 are covered by a partition wall 1205. Further, a partition wall 1205 is provided that covers the auxiliary wiring 1206 via the first electrode 1201. The light-emitting element 1250 is sealed by a support substrate 1229, a sealing substrate 1228, and a sealing material 1227.

[0186] In the light-emitting panel of this embodiment, a diffusion film of a polyester resin is used as the support substrate 1229, and a substrate having a thin glass layer and a polyethylene terephthalate (PET ) layer is used as the sealing substrate 1228. These substrates have flexibility, and the light-emitting panel of this embodiment is a flexible light-emitting panel. Also, the area of the light-emitting region in the light-emitting panel of this embodiment is 56 mm × 42 mm.

[0187] The light-emitting element 1250 is an organic EL element having a bottom emission structure. Specifically, it has a first electrode 1201 that transmits visible light on the support substrate 1229, and an EL layer 1202 on the first electrode 1201, and a second electrode 1203 that reflects visible light on the EL layer 1202. .

[0188] A method for manufacturing the light-emitting panel of this embodiment will be described.

[0189] First, a base film, a release layer (tungsten film), and a layer to be peeled off are formed in this order on a glass substrate, which is a manufacturing substrate. In this embodiment, the layer to be peeled off includes the insulating film 1224, the auxiliary wiring 1206, the first electrode 1201, and the partition wall 1205.

[0190] A total of seven auxiliary wirings 1206 were formed on the insulating film 1224. At this time, the pitch of the auxiliary wirings 1206 was set to 5.3 mm, and the width L2 was set to 322 μm. As the first electrode 1201, an indium tin oxide (ITSO) film containing silicon oxide was formed. A total of seven partition walls 1205 covering the auxiliary wirings 1206 were formed such that the width L1 was 330 μm.

[0191] Next, the temporary support substrate and the first electrode 1201 were adhered using a release adhesive, and the release layer was used to peel the layer to be peeled from the production substrate. As a result, the layer to be peeled was provided on the temporary support substrate side

[0192] Subsequently, the support substrate 1229 was bonded to the layer to be peeled, which was peeled from the production substrate and had the insulating film 1224 exposed, using an ultraviolet curable adhesive agent. As the support substrate 1229, as described above, a diffusion film of a polyester resin was used. Then, the temporary support substrate was peeled off, and the first electrode 1 229 was exposed on the support substrate 1229.

[0193] Next, an EL layer 1202 and a second electrode 1203 were formed on the first electrode 1201. The EL layer 1202 includes a first EL layer having a light-emitting layer containing a fluorescent compound that emits blue light from the first electrode 1201 side, an intermediate layer, and a second EL layer having a light-emitting layer containing a phosphorescent compound that emits green light and a light-emitting layer containing a phosphorescent compound that emits red light stacked in this order. Silver was used for the second electrode 1203.

[0194] Next, a photocurable resin containing zeolite, which is the encapsulant 1227, was applied and irradiated with ultraviolet light ​​​​It was cured in this way. Then, using an ultraviolet curable adhesive, the support substrate 1229 and the sealing substrate 1228, which is a thin glass layer and a polyethylene terephthalate (PET) layer, were bonded together with the substrate.

[0195] Measurements were made on the operating characteristics of the light-emitting panel obtained as described above. The voltage-luminance characteristics of the light-emitting panel at this time are shown as "Initial" in the legend of FIG. 11. Also, the emission spectrum of the light-emitting panel is shown in FIG. 12. As shown in FIG. 12, the light-emitting panel of this example emits light that includes light derived from a fluorescent compound that emits blue light, a phosphorescent compound that emits green light, and a phosphorescent compound that emits red light, respectively, showing an emission spectrum. It was found.

[0196] Thereafter, a reliability test of the light-emitting device using the light-emitting panel was conducted. As the reliability test, the light-emitting panel was made to emit light 3000 times or 10000 times at intervals. For each emission, a current of 2 A was passed through the light-emitting panel for 50 milliseconds (ms). The current density of the light-emitting element at this time was 90 mA / cm corresponding to. Also, the emission interval (non-emission time) was set to 10 seconds. 2

[0197] FIG. 11 shows the voltage-luminance characteristics of the light-emitting panel after emitting light 3000 times and after emitting light 10000 times.

[0198] From FIG. 11, the voltage-luminance characteristics of the light-emitting panel hardly changed even after emitting light 10000 times, and no deterioration of the light-emitting panel was observed. From this, the high reliability of the light-emitting panel of this example was shown.

Example

[0199] In this embodiment, an organic EL element applicable to one aspect of the present invention will be described.

[0200] In this embodiment, it was examined how much current could be passed through an organic EL element that emits white light. The light-emitting area of the organic EL element used was 2 mm × 2 mm. For each emission, a current was passed through the organic EL element for 50 milliseconds (ms).

[0201] As a result, a current of 60 mA could be passed through the organic EL element (corresponding to a current density of 1500 mA / cm 2 ). However, when a current of 68 mA was passed (corresponding to a current density of 1700 mA / cm 2 ), the organic EL element short-circuited. )

[0202] From this, it was suggested that in a light-emitting device of one aspect of the present invention to which an organic EL element is applied, the amount of light can be adjusted within a range where the current density is less than 17 00 mA / cm 2 . From this, it is considered that a larger current can be passed through an organic EL element compared to a light-emitting diode or the like using an inorganic material.

Explanation of Reference Numerals

[0203] 100 Light-emitting device 101 Light-emitting device 102 Light-emitting device 110 Open / close circuit 120 Light-emitting panel 130 Driving circuit 132 Start switch 140a Constant current power supply 140b Constant current power supply 150 Control device 155 Counter circuit 160 Optical sensor 162 Distance sensor 201 First electrode 203 EL layer 203a EL layer 203b EL layer 205 Second electrode 207 Intermediate layer 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 Encapsulation substrate 407 Encapsulant 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 730 Driving circuit 732 Start switch 740a Constant current power supply 740b Constant current power supply 750a Control device 750b Control device 1201 First electrode 1202 EL layer 1203 Second electrode 1205 Partition wall 1206 Auxiliary wiring 1209 Light extraction structure 1210 Conductive layer 1220 Support substrate 1224 Insulating film 1226 Encapsulant 1227 Encapsulant 1228 Encapsulation substrate 1229 Support substrate 1250 Light-emitting element 7300 Digital still camera 7301 Housing 7303 Light-emitting part 7304 Lens 7305 Non-light-emitting part 7310 Light-emitting device 7350 Mobile phone 7351 Housing 7352 Display part 7353 Light-emitting part 7353a Light-emitting panel 7353b Light-emitting panel 7354 Lens 7355 Non-light-emitting part 7360 Light-emitting device 7400 Bicycle 7405 Light 7410 Automobile 7415 Light

Claims

[Claim 1] a constant current power supply to which a control signal and a control pulse signal are supplied and which is capable of supplying a constant current pulse; a controller capable of providing said control signal; a drive circuit including a start switch and capable of supplying the control pulse signal in response to an opening and closing operation of the start switch; a light-emitting panel to which the constant current pulse is supplied, the control signal is a signal for controlling the magnitude of the constant current pulse, The light-emitting panel has a light-emitting element, The current density of the light emitting element is 10 mA / cm ２ More than 1000mA / cm ２ 1. A light-emitting device comprising:

Images