JP2005158483A - Lighting device and drive method of lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting device with improved life characteristics of an organic EL element. <P>SOLUTION: In the lighting device 100 having the organic EL element 10 as a light source, a plurality of organic EL element regions 10a, 10b formed on an identical substrate and a driving means 20 which supplies a forward current one by one for each organic EL element region are provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lighting device using an organic EL element as a light source and a driving method of the lighting device.

  In recent years, organic EL elements have attracted attention as self-luminous elements. An organic EL element has a configuration in which a thin light emitting layer made of an organic compound is sandwiched between electrodes, and emits light when a current is supplied between the electrodes. By using the organic EL element as a backlight of a liquid crystal display device or a light source of an illumination device, the illumination portion can be thinned, and thus the entire device can be easily reduced in size and weight.

  When an organic EL device is used as a planar light emitting device, for example, ITO electrodes used as anodes are formed as a plurality of independent electrode patterns in order to improve the light emitting lifetime, and the lifetime is proportional to the number of independent ITO electrodes. A technique for improving the characteristics is known (for example, see Patent Document 1).

In addition, an inorganic EL element is configured by arranging two sets of anodes and cathodes formed in a substantially comb-like shape so as to fit in a plan view, and a voltage is applied alternately to the two sets of electrodes. Thus, a technique for improving the light emission lifetime of an inorganic EL element is also known (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 10-233285 JP 2003-173880 A

  However, in the conventional organic EL element (Patent Document 1), the emission lifetime is improved in proportion to the number of independent ITO electrodes, and the emission lifetime of the single organic EL element itself is improved. Not a thing.

  In addition, an inorganic EL element emits light when a carrier is accelerated and excited by applying a high electric field and deactivated. On the other hand, in the organic EL element, electrons are injected from the cathode, holes are injected from the anode, and these recombine to emit light through an excited state. In the case of an organic EL element, the applied voltage is also relatively low. As described above, the element characteristics, the light emission mechanism, and the driving method are different between the inorganic EL element and the organic EL element, and the light emission life is improved by alternately applying a voltage between the two sets of the anode and the cathode. The conventional technique (Patent Document 2) cannot be applied as it is when the organic EL element is driven.

  The subject of this invention is providing the illuminating device which improved the lifetime characteristic of the organic EL element.

  In order to solve the above-described problem, the invention described in claim 1 is a lighting device using an organic EL element as a light source, and includes a plurality of organic EL element regions formed on the same substrate and each of the organic EL element regions. And a driving means for sequentially supplying a forward current.

  According to a second aspect of the present invention, in the illumination device according to the first aspect, the driving unit instantaneously reverses the organic EL element region after supplying a forward current to the organic EL element region for a predetermined time. A directional current is supplied.

  According to a third aspect of the present invention, in a lighting device using an organic EL element as a light source, a forward current is supplied to a plurality of organic EL element regions formed on the same substrate and any one of the organic EL element regions. And driving means for sequentially performing the operation of supplying the reverse current to the other organic EL element regions for each organic EL element region.

  According to a fourth aspect of the present invention, in the illuminating device according to any one of the first to third aspects, the driving unit is configured to change each organic EL element region according to a ratio of light emitting areas of the organic EL element regions. The time for supplying the forward current is determined.

  According to a fifth aspect of the present invention, in the illumination device according to any one of the first to fourth aspects, a light emitting area of each organic EL element region is relatively substantially equal.

  A sixth aspect of the present invention is the illumination device according to any one of the first to fifth aspects, wherein each of the organic EL element regions is formed by connecting a plurality of organic EL elements in series. It is characterized by that.

  The invention according to claim 7 is the illuminating device according to any one of claims 1 to 6, wherein the diffusion plate diffuses light emitted from the organic EL element region on the light emitting surface of each organic EL element region. It is provided with.

  According to an eighth aspect of the present invention, in a driving method of an illuminating device for driving an illuminating device using an organic EL element as a light source, a plurality of organic EL element regions are formed on the same substrate, and each organic EL element region is The forward current is supplied sequentially.

  According to a ninth aspect of the present invention, in the method of driving an illumination device according to the eighth aspect, after a forward current is supplied to the organic EL element region for a predetermined time, a reverse current is instantaneously applied to the organic EL element region. It is characterized by supplying.

  According to a tenth aspect of the present invention, in the driving method of an illuminating device for driving an illuminating device using an organic EL element as a light source, a plurality of organic EL element regions are formed on the same substrate, and any one of the organic EL element regions is formed. The operation of supplying the forward current to the other organic EL element regions and the backward current to the other organic EL element regions is sequentially performed for each organic EL element region.

  According to the first or eighth aspect of the present invention, a plurality of organic EL element regions are formed on the same substrate, and a forward current is sequentially supplied to each organic EL element region by the driving means. The light emission lifetime of each organic EL element region can be improved by blinking the organic EL element region.

  According to the second or ninth aspect of the present invention, it is possible to extract electric charges from the organic EL element without damaging the organic EL element, and it is possible to extend the life of the organic EL element.

  According to the invention described in claim 3 or 10, a plurality of organic EL element regions are formed on the same substrate, a forward current is supplied to any one of the organic EL element regions by the driving means, and another organic EL element is supplied. Since the operation for supplying the reverse current to the element region is sequentially performed for each organic EL element region, each organic EL element region flashes and emits light, and the charge remaining in the organic EL element is supplied by supplying the reverse current when the light is extinguished. It can be pulled out, and the life characteristics of the organic EL element can be improved.

  According to the invention described in claim 4, since the time for supplying the forward current to each organic EL element region is determined according to the ratio of the light emitting area of each organic EL element region, the area of the organic EL element region Regardless of the size, the light emission amount of each organic EL element region can be made equal.

  According to the fifth aspect of the present invention, since the light emission areas of the respective organic EL element regions are relatively equal, the light emission amounts from the respective organic EL element regions can be made substantially equal.

  According to the invention described in claim 6, by configuring each organic EL element region by connecting a plurality of organic EL elements in series, the drive voltage per one organic EL element can be divided. It becomes easy to drive an organic EL element with improved luminous efficiency at high voltage.

  According to the seventh aspect of the present invention, since the diffusion plate is provided on the light emitting surface of the organic EL element region, the light emission from the organic EL element region can be diffused to make the luminance uniform.

  The best mode for carrying out the illumination device according to the present invention will be described below with reference to the drawings. FIG. 1 schematically shows an organic EL element 10 used as a light source of the illumination device 100 (see FIG. 2) in the best mode. As shown in FIG. 1, the organic EL element 10 includes an anode 12, an organic layer 13 including a light emitting layer, and a cathode 14 on a substrate 11, and these layers are sequentially stacked.

  The light emission mechanism of the organic EL element 10 is as follows. When a forward current is supplied to the organic EL element 10 from the outside via the anode 12 and the cathode 14, electrons and holes injected in the organic layer 13 are combined to excite organic molecules. When the excited organic molecule returns to the ground state, the difference energy is emitted as light. The emitted light passes through the anode 12 and the substrate 11 and is emitted.

  Note that the configuration of the organic EL element 10 is not limited to the mode shown in FIG. 1, and the anode 12 and the cathode 14 may be stacked on the substrate 11 in the order opposite to the order shown in FIG. 1. Alternatively, a top emission configuration in which light emitted from the organic layer 13 is emitted from a substantially transparent cathode obtained by laminating a thin film cathode material and an anode material having high transmittance may be employed.

Next, each layer will be described.
The substrate 11 may be a solid substrate or a flexible substrate.
As the base material of the solid substrate, glass, quartz or the like can be used.
As the base material of the flexible substrate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), Cellulose triacetate (TAC), cellulose acetate propionate (CAP) and the like can be used.

  The anode 12 is a transparent electrode that transmits light. For example, indium tin oxide (ITO), indium zinc oxide (IZO), gold, tin oxide, zinc oxide and the like have a work function of 4 eV or more and a transmittance of 40% or more. The conductive material can be used.

  The organic layer 13 may have a single-layer configuration including only a light-emitting layer, or a multi-layer configuration including a three-layer configuration in which the light-emitting layer is sandwiched between a hole transport layer and an electron transport layer. The organic layer 13 has a thickness of several nm to several μm.

  The light emitting layer includes an organic light emitting material composed of an organic compound or a complex. In order to emit light efficiently, it is effective to shorten the moving distance of carriers, and it is desirable to reduce the thickness of the light emitting layer. Organic light-emitting materials include fluorescent materials that emit the energy difference as fluorescence when returning from the single excited state to the ground state, and phosphorescent materials that emit the energy difference when returning from the triple excited state to the ground state as phosphorescence. However, it is particularly preferable to use a phosphorescent material from the viewpoint of luminous efficiency and lifetime.

  Note that organic molecules are generally vulnerable to moisture and oxygen, and have a high probability of being deteriorated by reacting with oxygen or moisture in the atmosphere, particularly when in an excited state. Therefore, in an organic EL element, it is common to cover and seal the organic layer 13 with a metal tube or glass tube under an inert gas atmosphere such as nitrogen, and shield from the external atmosphere. For simplification of description, drawings and description of sealing of the organic EL element 10 are omitted.

  When the hole transport layer is provided, the hole transport layer is provided in contact with the anode 12. When the electron transport layer is provided, the electron transport layer is provided in contact with the cathode 14. Further, when the organic layer 13 has a multi-layer structure, a lithium fluoride layer, an inorganic metal salt layer, a layer containing them, or the like may be disposed at an arbitrary position.

  The cathode 14 is a reflective electrode that reflects light, and can be made of a metal material having a work function of less than 4 eV and a reflectivity of 60% or more, such as aluminum, sodium, lithium, magnesium, silver, and calcium. .

  In addition, when using the organic EL element 10 as a light source of an illuminating device, it is desirable to whiten, but since there is no single luminescent material that shows white, as a method for whitening, a different emission maximum wavelength is shown. A method of forming a light emitting layer from two or more light emitting materials, or a light emitting material having at least one light emission maximum wavelength from the light emitting layer and light from the light emitting layer as excitation light to absorb In this method, a fluorescent material that emits light in a longer wavelength region than the excitation light is dispersed in the light emitting layer, the substrate 11 or the like by emitting light from the phosphor, and whitened with two or more different emission maximum wavelengths. May be.

  Next, an illumination device 100 to which the organic EL element 10 is applied will be described with reference to FIG. FIG. 2A shows a plan view of the illumination device 100, and FIG. 2B shows a cross-sectional view.

  As shown in FIG. 2A, the lighting device 100 includes two organic EL element regions 10a and 10b formed in a comb shape on the same substrate 11 in plan view, and the organic EL element regions 10a and 10b. On the other hand, there is provided driving means 20 for alternately supplying a forward current.

  In plan view, the comb tooth portions 101b formed in the other organic EL element regions 10b are formed in the recesses 101a formed in one organic EL element region 10a so that the organic EL element regions 10a and 10b do not overlap each other. Patterned to fit. Further, the light emitting areas of both the organic EL element regions 10a and 10b are formed to be relatively equal.

  As shown in FIG. 2B, each of the organic EL element regions 10a and 10b is formed from the organic EL element 10 described above, and includes an anode 12 formed on the substrate 11, an organic layer 13, and comb teeth. The cathode 14 patterned in the shape is provided.

  As described above, the driving unit 20 supplies forward current to the organic EL element regions 10a and 10b alternately so that the organic EL element regions 10a and 10b emit light alternately. After the forward current is supplied to the organic EL element region 10a, the current supply switching operation is performed so as to supply the forward current to the other organic EL element region 10b.

  The light emission lifetime of each organic EL element region 10a, 10b can be improved by blinking each organic EL element region 10a, 10b.

  The driving unit 20 supplies a forward current to one organic EL element region 10a, supplies a reverse current to the other organic EL element region 10b, and supplies a forward current to the other organic EL element region 10b. A current supply switching operation for supplying a reverse current to one organic EL element region 10a may be sequentially and repeatedly performed.

  As described above, the organic EL element regions 10a and 10b are caused to blink and emit light, and by supplying a reverse current when the organic EL element regions are turned off, charges remaining in the organic EL element 10 can be extracted. The lifetime characteristic of the element 10 can be improved.

  Further, the driving unit 20 supplies a forward current to one organic EL element region 10a for a predetermined time, and then supplies a forward current to another organic EL element region 10b for a predetermined time. A current supply switching operation for instantaneously supplying the reverse current to the region 10a may be performed.

  By supplying the reverse current instantaneously when the organic EL element regions 10a and 10b are turned off, the charge can be extracted from the organic EL element 10 without damaging the organic EL element 10. Further, the lifetime of the organic EL element 10 can be further increased.

  In addition, the driving means 20 does not perform any of the above-described current supply switching operations, but the respective organic light emission amounts are equalized according to the ratio of the light emission areas of the organic EL element regions 10a and 10b. It is preferable to determine the time for supplying the forward current to the EL element regions 10a and 10b. In this embodiment, since the light emission areas of one organic EL element region 10a and the other organic EL element region 10b are formed to be substantially equal, the driving means 10 distributes the same time to each of the organic EL element regions 10a and 10b. The current supply switching operation is performed so that the forward current is supplied. On the other hand, for example, when the ratio of the light emission area of one organic EL element region to another organic EL element region is 30%: 70%, the time during which forward current is supplied to one organic EL element region The current supply switching operation is performed so that the ratio of the forward current supplied to the other organic EL element regions is 70%: 30%. The same applies to the case where two or more organic EL element regions are provided.

  As shown in FIG. 2B, the substrate 11 is preferably provided with a diffusion plate 15 in order to make the luminance of the entire light emitting surface A of the lighting device 100 uniform. The diffusion plate 15 is provided on the light emitting surface side of each organic EL element region 10a, 10b, and diffuses light emitted from each organic EL element region 10a, 10b. Thereby, it can be made as if it was light-emitted from the light emission surface A whole.

  In the lighting device 100 shown in FIG. 2, the shape of the cathode 14 is two independent comb-shaped electrodes, but the shape of the anode 12 may be a comb-shaped shape.

  Moreover, if each organic EL element area | region 10a, 10b can be made to light alternately, the shape of organic EL element area | region 10a, 10b and an electrode will not be limited to a comb-tooth shape, The shape of the light emission surface of the illuminating device 100 Depending on the case, an appropriate shape can be obtained. For example, as shown in FIG. 3A, the shape may be a combination of triangle shapes, and when the light emitting surface is circular or elliptical as shown in FIG. 3B, it is formed in a spiral shape. The two sets of organic EL element regions 10a and 10b may be patterned into a shape that fits in plan view. The light emitting areas of the two sets of organic EL element regions 10a and 10b are preferably substantially equal, and each organic EL element region 10a and 10b is preferably configured to be uniformly distributed over the entire light emitting surface.

  Further, the number of organic EL element regions and the number of independent electrodes are not limited to two, and may be two or more. Even in that case, it is preferable that the light emitting areas of the respective organic EL element regions are relatively substantially equal, and it is preferable that the respective organic EL element regions are configured to be uniformly distributed with respect to the light emitting surface.

  When the number of organic EL element regions is two or more, the driving unit 20 may sequentially supply a forward current for each organic EL element region. At this time, the driving means supplies the forward current to any one of the organic EL element areas and simultaneously supplies the backward current to the other organic EL element areas. May be.

  Furthermore, as shown in FIG. 4, each organic EL element region 10a, 10b may be configured by connecting a plurality of organic EL elements 10 in series. In this case as well, the shape of each organic EL element 10 may be appropriately selected according to the light emitting surface, and may be a rectangular shape as shown in FIG. Of course, it may have a polygonal shape or the like and is not particularly limited.

  As shown in FIG. 4, the drive voltage per organic EL element can be divided by configuring each organic EL element region 10a, 10b by connecting a plurality of organic EL elements 10 in series. It becomes easy to drive the organic EL element with improved luminous efficiency at high voltage.

Next, a specific configuration example of the driving unit 20 of the lighting device 100 will be described.
As shown in FIG. 5, the driving means 20 can be composed of a DC power source 21, a control means 22, switching means 23a, 23b, and the like.

  The DC power source 21 is an operating power source for the control unit 22 and the switching units 23a and 23b, and also serves as a current source that supplies current to each of the organic EL element regions 10a and 10b. Further, the DC power source 21 may be a secondary battery or the like, or may be a DC power source that is used by converting from a nominal 100V AC commercial power source supplied to a general household to DC. The DC power supply 21 may be a constant current source or a constant voltage source.

  The control means 22 supplies control pulses to the switching means 23a and 23b, and the switching means 23a and 23b forward the current supply to the organic EL element regions 10a and 10b by the control pulse supplied from the control means 22. And switch to the opposite direction.

  The switching means 23a and 23b are provided for each of the organic EL element regions 10a and 10b. In accordance with the control pulse supplied from the control means 22, the forward current and the reverse current are alternately supplied to the organic EL element regions 10a and 10b, respectively. The current supply switching operation to supply to

  Next, the current supply switching operation of the forward current and the reverse current by the switching means 23a will be described with reference to FIG. 6 showing a circuit configuration example of the switching means 23a. FIG. 6 shows only one switching unit 23a, but the configuration and operation of the other switching unit 23b are the same as those of the one switching unit 23a.

  The switching means 23a can be configured using a first transistor Tr1, a second transistor Tr2, a third transistor Tr3, a fourth transistor Tr4, a first resistor R1, a second resistor R2, and the like.

  By switching on / off the transistors Tr1, Tr2, Tr3, Tr4 by the control pulse b supplied from the control means 22, forward current or reverse current is applied to the organic EL element 10 constituting the organic EL element region 10a. Supply directional current. Each of the transistors Tr1, Tr2, Tr3, Tr4 can be configured using, for example, a TFT (Thin Film Transistor).

  Specifically, when the signal level of the control pulse b supplied from the control means 22 is “H” level, the “H” level control signal is applied to the first transistor Tr1 and the third transistor Tr3, These transistors Tr1 and Tr3 are turned on. At this time, an "L" level control signal obtained by inverting the signal level of the control pulse b by the inverter 24 is applied to the second transistor Tr2 and the fourth transistor Tr4, and the transistors Tr2 and Tr4 are turned off. .

  Thereby, a current flows from the DC power source 21 in the order of the first transistor Tr1 → the organic EL element 10 → the third transistor Tr3, a forward current is supplied to the organic EL element 10, and the organic EL element 10 is turned on.

  On the other hand, when the signal level of the control pulse b supplied from the control means 22 is “L” level, the first transistor Tr1 and the third transistor Tr3 are turned off by applying the “H” level control signal, and the second transistor An "H" level control signal is applied to the Tr2 and the fourth transistor Tr4 by the inverter 24 and turned on.

  As a result, a current flows from the DC power supply 21 in the order of the fourth transistor Tr4 → the organic EL element 10 → the second transistor Tr2, and a reverse current is supplied to the organic EL element 10. Thereby, the electric charge remaining in the organic EL element 10 is extracted and the organic EL element 10 is turned off.

  The first resistor R1 and the second resistor R2 are variable resistors, and the voltage value applied from the DC power source 21 to the organic EL element 10 is adjusted by changing the voltage dividing ratio by changing the resistance value. The voltage value when the forward current is supplied to the organic EL element 10 can be adjusted by the first resistor R1, and the voltage value when the reverse current is supplied can be adjusted by the second resistor R2. That is, by providing the first resistor R1 and the second resistor R2, voltage adjustment at the time of forward current supply and at the time of reverse current supply can be performed individually, and the voltage at which the organic EL element 10 exhibits optimum light emission characteristics. It can adjust so that can be applied.

  Note that the blinking light emission period of the organic EL element 10 by switching between the forward current supply operation and the reverse current supply operation for the organic EL element 10 by the switching means 23a is determined by the period of the control pulse b supplied from the control means 22. The ratio of the time for lighting in the forward direction is determined by the duty ratio of the control pulse b. The blinking cycle is preferably 50 Hz or more, at which a person hardly perceives flickering of brightness due to blinking, and more preferably a frequency exceeding the audible frequency band of the human ear, for example, 20 kHz or more. Thereby, generation | occurrence | production of operation sounds, such as an annoying oscillation sound, can be prevented.

  In FIG. 6, the current supply switching operation for switching between the forward current supply operation and the reverse current supply operation for the organic EL element region 10 a by showing one switching means 23 a has been described. However, as described above, the other switching means 23 b Have the same circuit configuration, and the forward current supply operation and the reverse current supply operation are switched by the control pulse supplied from the control means 22 in the same manner as the one switching means 23a. At this time, a control pulse obtained by inverting the control pulse b is output to the other switching means 23b. By applying the inverted control pulse to the other switching means 23b, the one organic EL element region 10a and the other organic EL element region 10b can emit light alternately. Thus, by sequentially emitting light from the plurality of organic EL element regions 10a and 10b, the luminance of light emitted from the light emitting surface A can be kept constant, and flickering can be made difficult to feel.

It should be noted that the present invention is not limited to the above-described best mode, and can of course be changed as appropriate without departing from the spirit of the present invention.
For example, the switching means 23a shown in FIG. 6 is configured to always supply a reverse current when the organic EL element region 10a is extinguished. However, the present invention is not limited to this, and the reverse current is supplied instantaneously. It is good also to do. For example, when a reverse current is supplied to the organic EL element region 10a, a one-shot circuit that receives an inverted input of the control pulse b and instantaneously outputs an ON signal to the second transistor Tr2 and the fourth transistor Tr4 is provided. By providing the switching means 23a, a reverse current can be instantaneously supplied to the organic EL element region 10a, and the charge charged by the supply of the forward current can be organically supplied without damaging the organic EL element 10. The EL element 10 can be pulled out.

A specific configuration example of the one-shot circuit is shown in FIG. The one-shot circuit shown in FIG. 7 is configured using a D-type flip-flop 25 and an RC time constant circuit 26. The clock input terminal CLK of the D-type flip-flop 25 is connected to the output terminal of the inverter 24, and the output terminal Q is connected to the gate terminals of the second transistor Tr2 and the fourth transistor Tr4. One end of the resistor R3 of the RC time constant circuit 26 is connected to the output terminal Q of the D-type flip-flop and the second transistor Tr2 and the fourth transistor Tr4, and the other end is connected to the reset terminal R of the D-type flip-flop 25. It is connected to the capacity C. According to this one-shot circuit, as shown in FIG. 7B, the second transistor Tr2 and the fourth transistor Tr4 are turned on in synchronization with the fall of the control pulse b, and after the RC time constant (about 0. 7RC), the second transistor Tr2 and the fourth transistor Tr4 are turned off. As a result, a reverse current is instantaneously (approximately 0.7 RC) supplied to the organic EL element region 10a.
Of course, a similar one-shot circuit may be provided for the other switching means 23b.

  Furthermore, in the drive means 20 shown in FIGS. 6 and 7, the reverse current is supplied when the organic EL element 10a is turned off, but the present invention is not limited to this. As described above, the driving means 20 only needs to be able to supply forward current alternately to one organic EL element region 10a and another organic EL element region 10b. For example, as shown in FIG. The switching unit may be configured by using the first transistor Tr1 and the forward current may be intermittently supplied to the organic EL element 10 according to the control pulse b supplied from the control unit 22. At this time, with respect to the other organic EL element region 10b, by applying the inverted control pulse from the control means 22 to the other switching means having the same configuration as this one switching means, The organic EL element regions 10b can be alternately turned on.

  Further, in the switching means 23a shown in FIGS. 6 and 7, the voltage dividing ratio is changed by changing the resistance values of the first resistor R1 and the second resistor R2, and applied from the DC power source 21 to the organic EL element 10. Although the voltage value is adjusted, the present invention is not limited to this. For example, current detection means for detecting a current value supplied to the organic EL element 10 and constant current control for controlling the organic EL element 10 to be supplied with a constant current based on the current value detected from the current detection means. Means may be provided to perform constant current control. The constant current control means can be configured using, for example, a differential amplifier.

  Moreover, as shown in FIG. 9, the current detection means 24a, 24b which detects the electric current which flows into the organic EL element 10 for each organic EL element area | region 10a, 10b is provided, and the electric current value detected by the current detection means 24a, 24b Based on the control pulse, the duty ratio of the control pulse may be adjusted to control the time for supplying the forward current to the organic EL element 10. Thereby, brightness fixed control that keeps the light emission brightness of the lighting device 100 constant may be performed, or light control may be performed so that the brightness is instructed from the outside by a user or the like.

It is the schematic diagram which showed the structure of the organic EL element of an example of this invention. It is the top view (a) and sectional drawing (b) which showed typically the structure of the illuminating device of an example of this invention. It is the top view (a) and (b) which showed typically the structure of the illuminating device of the other example of this invention. In the illuminating device 100 of FIG. 2, it is the top view which showed typically the example by which the several organic EL element was comprised in series in the organic EL element area | region 10a, 10b. It is a block diagram which shows the functional structure of an example of the drive means 20 of FIG. It is a figure which shows the circuit structural example of the drive means 20 of the illuminating device 100 of FIG. FIG. 6A is a diagram illustrating another circuit configuration example of the driving unit 20 of the illumination device 100 of FIG. 2 and a timing chart illustrating the change in the signal level of the transistors Tr1 to Tr4. It is a figure which shows the other circuit structural example of the drive means 20 of the illuminating device 100 of FIG. It is a block diagram which shows the functional structure of the other example of the drive means 20 of the illuminating device 100 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Organic EL element 10a, 10b Organic EL element area | region 11 Board | substrate 12 Anode 13 Organic layer 14 Cathode 15 Diffusion plate 20 Drive means 21 DC power supply 22 Control means 23a Switching means 23b Switching means A Light emission surface b Control pulse 100 Illuminating device

Claims (10)

In an illumination device using an organic EL element as a light source,
A plurality of organic EL element regions formed on the same substrate;
Drive means for sequentially supplying a forward current for each organic EL element region;
An illumination device comprising: The lighting device according to claim 1.
The driving unit supplies a forward current to the organic EL element region for a predetermined time, and then instantaneously supplies a reverse current to the organic EL element region. In an illumination device using an organic EL element as a light source,
A plurality of organic EL element regions formed on the same substrate;
Driving means for sequentially supplying the forward current to any one of the organic EL element regions and supplying the reverse current to the other organic EL element regions with respect to each organic EL element region;
An illumination device comprising: In the illuminating device as described in any one of Claims 1-3,
The driving device determines a time for supplying a forward current to each organic EL element region in accordance with a ratio of light emitting areas of the organic EL element regions. In the illuminating device as described in any one of Claims 1-4,
The light emitting area of each said organic EL element area | region is relatively substantially equal, The illuminating device characterized by the above-mentioned. In the illuminating device as described in any one of Claims 1-5,
Each of the organic EL element regions is formed by connecting a plurality of organic EL elements in series. In the illuminating device as described in any one of Claims 1-6,
An illuminating device comprising a diffusion plate for diffusing light emitted from the organic EL element region on a light emitting surface of each organic EL element region. In a driving method of a lighting device for driving a lighting device using an organic EL element as a light source,
A driving method of a lighting device, wherein a plurality of organic EL element regions are formed on the same substrate, and a forward current is sequentially supplied to each organic EL element region. The driving method of the lighting device according to claim 8.
A driving method of a lighting device, wherein a forward current is instantaneously supplied to the organic EL element region after a forward current is supplied to the organic EL element region for a predetermined time. In a driving method of a lighting device for driving a lighting device using an organic EL element as a light source,
The operation of forming a plurality of organic EL element regions on the same substrate, supplying a forward current to any one of the organic EL element regions and supplying a reverse current to the other organic EL element regions A method for driving an illuminating device, which is sequentially performed on regions.

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