JP4696896B2 - Organic EL lighting panel and organic EL lighting device - Google Patents

Description

  The present invention relates to an organic EL lighting panel using organic EL (electroluminescence), and more particularly to an organic EL lighting panel that can reduce luminance unevenness. And it is related with the organic EL lighting apparatus using this organic EL lighting panel.

  Organic EL elements have been researched and developed for a relatively long time because they are brighter and clearer than liquid crystal elements because of self-luminescence. In particular, in 1987, Kodak's C.I. W. Since Tang et al. Proposed an organic EL device with a laminated structure, this device has been attracting attention because of its excellent power consumption, brightness, responsiveness, and viewing angle. Yes.

  FIG. 2 is a perspective view showing the structure of the organic EL display described in Patent Document 1. As shown in FIG. In FIG. 2, a typical organic EL display 500 includes a glass substrate 501, a strip-shaped anode group 502 formed on the glass substrate 501, and an anode group 502 as disclosed in, for example, Patent Document 1. A hole-transporting organic layer 503 formed almost on the entire surface, an organic layer 504 having an electron-transporting property and a light-emitting function, and a strip-shaped cathode formed on the organic layer 504 in a direction perpendicular to the anode group 502 And a group 505. The anode group 502 is made of a conductive transparent thin film such as ITO, and the cathode group 505 is made of a metal thin film such as silver magnesium alloy (AgMg).

  In the organic EL display 500 having such a structure, one of the orthogonal electrode groups (the anode group 502 and the cathode group 505) is used as a scan electrode, and a scan signal divided in time is sequentially applied to each scan electrode. And a selection signal corresponding to whether or not to display a pixel intersecting with the scanning electrode is supplied to each signal electrode, and the pixel to be displayed emits light.

Here, for example, a conductive transparent thin film such as ITO has a resistivity on the order of 10 ⁻⁴ Ω · cm, and has a relatively high resistance compared to metal, and therefore, from a power supply terminal that receives power supply from a power source. There is an inconvenience that a large reduction in luminance occurs in distant display pixels.
JP 2000-123980 A

  By the way, even when the strip-like cathode group 505 is replaced with a planar cathode electrode layer to constitute an organic EL lighting panel, the same disadvantages as those of the organic EL display 500 occur. That is, for example, a conductive transparent thin film such as ITO has a relatively high resistance, which causes a disadvantage that luminance is greatly reduced on the light emitting surface far from the power supply terminal and luminance unevenness occurs. In particular, for lighting, this inconvenience is serious because the area of the light emitting surface needs to be relatively wide.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an organic EL lighting panel capable of reducing luminance unevenness. And it aims at providing the organic EL lighting apparatus using this organic EL lighting panel.

As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, in one embodiment of the present invention, an organic EL layer formed by sandwiching an organic light emitting layer including at least a light emitting layer between a pair of first and second electrode layers, at least one of which is light transparent, is provided on a light transmitting substrate. In the organic EL lighting panel provided with a sealing member disposed and cooperating with the substrate to seal the organic EL layer, the organic light emitting layer is a single layer corresponding to the entire light emitting surface , 1 and the one of the second electrode layer, in the light-emitting surface side, consists a plurality of parallel linear or strip-shaped transparent electrodes to each other, mutually opposing pair of transparent electrodes adjacent in the plurality of transparent electrodes power is supplied from the power supply at the end, the other of the first and second electrode layers are characterized by planar electrode der Rukoto corresponding to the organic light emitting layer.

  The organic EL lighting device according to an aspect of the present invention includes a plurality of switching devices that are inserted into the above-described organic EL lighting panel and the power supply lines of the plurality of electrodes, respectively, and turn on and off the power from the power source. And a dimming control unit that controls on / off of each of the plurality of switching elements.

  The organic EL lighting panel and the organic EL lighting device having such a configuration can reduce luminance unevenness as compared with the background art.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

  FIG. 1 is a diagram illustrating a configuration of an organic EL lighting device according to an embodiment. FIG. 1A shows a front surface and a driving unit of the organic EL lighting panel, and FIG. 1B shows a cross section of the organic EL lighting panel taken along line AA in FIG.

  In FIG. 1, an organic EL lighting device 1 includes a substrate 11, a first electrode layer 12 stacked on one surface 111 of the substrate 11, an organic light emitting layer 13 stacked on the first electrode layer 12, an organic An organic EL lighting panel 10 including a second electrode layer 14 stacked on the light emitting layer 13, first and second sealing members 15, 16, a plurality of switching elements 21, and a dimming control unit 22. The drive part 20 provided is comprised.

  The substrate 11 is a flat plate-like member for supporting an organic EL layer formed by sandwiching an organic light emitting layer 13 including at least a light emitting layer by a pair of first and second electrode layers 12 and 14 having at least one light transmitting property. Yes, it is made of a material transparent to the wavelength of light emitted from the organic light emitting layer 13, such as glass.

  The first electrode layer 12 is composed of a plurality of linear or belt-like electrodes 121 parallel to each other, and is a conductive thin film made of a material transparent to the wavelength of light emitted from the organic light emitting layer 13 and serves as an anode. . Since the organic light emitting layer 13 emits visible light, the first electrode layer 12 is formed of, for example, ITO (Indium Tin Oxide) that transmits visible light. The electrode 121 of the first electrode layer 12 is formed so that a part thereof is exposed from the first sealing member 15, and a part of the electrode 121 includes an anode feeding region 122 for receiving power supply from the DC power supply 30. Constitute. In the example shown in FIG. 1, the first electrode layer 12 includes six electrodes 121-1 to 121-6, and is formed so that both ends thereof are exposed from the first sealing member 15. Anode feeding regions 122-1 to 122-6 are configured. In the example shown in FIG. 1, the number of electrodes 121 of the first electrode layer 12 is six, but the number is arbitrary. For example, the size and light emission amount of the organic EL lighting panel 10 are taken into consideration according to the specifications. It is determined appropriately.

  Here, in this specification, when referring generically, it shows with the reference symbol which abbreviate | omitted the suffix, and when referring to an individual structure, it shows with the reference symbol which attached the suffix.

The organic light emitting layer 13 includes at least a light emitting layer made of an organic material of a fluorescent material or an organic material containing a fluorescent material, and if necessary, a hole injection layer, a hole transport layer, an electron transport layer and an electron injection Provide layers. More specifically, the first and second electrode layers 12 and 14 are also described, for example, the following layer structure.
(1) (first electrode layer 12; anode) / light emitting layer / (second electrode layer 14; cathode)
(2) (first electrode layer 12; anode) / hole transport layer / light emitting layer / (second electrode layer 14; cathode)
(3) (first electrode layer 12; anode) / light emitting layer / electron transport layer / (second electrode layer 14; cathode)
(4) (first electrode layer 12; anode) / hole transport layer / light emitting layer / electron transport layer / (second electrode layer 14; cathode)
(5) (first electrode layer 12; anode) / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / (second electrode layer 14; cathode)

  The second electrode layer 14 is a conductive thin film and serves as a cathode. The second electrode layer 14 may be formed of a material that is transparent to the wavelength of light emitted from the organic light emitting layer 13 as in the case of the first electrode layer 12, but in the present embodiment, the organic light emitting layer 13 emits light. In order to increase the light extraction efficiency, the organic light emitting layer 13 is formed of a material that reflects the light emitted. The second electrode layer 14 is made of, for example, a metal such as aluminum (Al), aluminum lithium (Al: Li), magnesium silver (Mg: Ag), an alloy, or the like. In the present embodiment, for example, the second electrode layer 14 is made of aluminum, for example, from the viewpoint of conductivity, reflectance, cost, and the like. A cathode terminal 141 is disposed on the second electrode layer 14 so as to be electrically connected to the second electrode layer 14 and partly exposed from the first sealing member 15.

  The first and second sealing members 15 and 16 are insulating members for hermetically sealing the organic light emitting layer 13 in cooperation with the substrate 11. For example, a first sealing member 15 made of resin having adhesiveness is applied so as to cover the first electrode layer 12, the organic light emitting layer 13, and the second electrode layer 14 excluding the anode feeding region 122, for example, a glass plate The second sealing member 16 made of a shaped member is placed on the second electrode layer 14 via the first sealing member 15 and pressure is applied, whereby the second sealing member 16 becomes the first sealing member. 15 is bonded to the second electrode layer 14, and the peripheral edge portion of the second sealing member 16 is hermetically bonded and bonded to the substrate 11 by the first sealing member 15. Accordingly, the first and second sealing members 15 and 16 cooperate with the substrate 11 to hermetically seal the organic light emitting layer 13.

  The switching element 21 is an element for turning on and off the power from the DC power supply 30 by being inserted into each power supply line in the plurality of electrodes 121 constituting the first electrode layer 12. For this reason, the number of switching elements 21 is the same as the number of electrodes 121 constituting the first electrode layer 12. The switching element 21 is, for example, an element with a control terminal to which a control signal for switching on and off is input. More specifically, the switching element 21 is, for example, a MOS transistor or a bipolar transistor. In the example shown in FIG. 1, MOS transistors 21-1 to 21-6 are used.

  The dimming control unit 22 is a circuit that controls ON / OFF of the switching element 21, and outputs a control signal to the control terminal of the switching element 21. In the example shown in FIG. 1, the dimming control unit 22 is connected to each gate electrode of each MOS transistor 21-1 to 21-6, and a control signal is sent to each gate electrode of each MOS transistor 21-1 to 21-6. Respectively.

  What should be noted here is that power from the DC power supply 30 is alternately supplied to the anode power supply regions 122 at the ends of the plurality of electrodes 121 constituting the first electrode layer 12. That is, a plurality of switching elements 21 are respectively inserted between the DC power supply 30 and each electrode 121, and one terminal of each of the plurality of switching elements 21 is commonly connected to the anode of the DC power supply 30. The other terminals of the plurality of switching elements 21 are connected to the anode feeding regions 122 at the ends facing each other in the pair of adjacent electrodes of the plurality of electrodes 121. The cathode of the DC power supply 30 is connected to the cathode terminal 141.

  In the example shown in FIG. 1, the source electrodes of the MOS transistors 21-1 to 21-6 are commonly connected to the anode of the DC power supply 30, and the drain electrodes of the MOS transistors 21-1 to 21-6 are connected. The plurality of electrodes 121-1 to 212-6 are alternately connected to the anode power feeding regions 122-1 to 122-6 at the ends. More specifically, the drain electrode of the MOS transistor 21-1 is connected to the anode feeding region 122-1 at one end (upper side in FIG. 1) in the longitudinal direction of the electrode 121-1, and the drain of the MOS transistor 21-2. The electrode is connected to the anode feeding region 122-2 at the other end in the longitudinal direction of the electrode 121-2 adjacent to the electrode 121-1 (the end facing the one end in the longitudinal direction, the lower side in FIG. 1). The drain electrode of the MOS transistor 21-3 is connected to the anode feeding region 122-3 at one end in the longitudinal direction (upper side in FIG. 1) of the electrode 121-3 adjacent to the electrode 121-2, and the MOS transistor 21-4 Is connected to the anode feeding region 122-4 at the other end (lower side in FIG. 1) in the longitudinal direction of the electrode 121-4 adjacent to the electrode 121-3. The drain electrode of the transistor 21-5 is connected to the anode feeding region 122-5 at one end in the longitudinal direction (upper side in FIG. 1) of the electrode 121-5 adjacent to the electrode 121-4, and the MOS transistor 21-6 The drain electrode is connected to the anode feeding region 122-6 at the other end (lower side in FIG. 1) in the longitudinal direction of the electrode 121-6 adjacent to the electrode 121-5.

  As described above, in the pair of adjacent electrodes 121 in the plurality of electrodes 121 constituting the first electrode layer 12, the power from the DC power supply 30 is supplied at the ends of the electrodes 121 in the longitudinal direction facing each other. That is, in the pair of electrodes 121 adjacent to each other in this way, the pair of switching elements 21 are connected to the ends of the electrodes 121 in the longitudinal direction facing each other.

  In the above description, the switching element 21 is directly connected to the electrode 121 of the first electrode layer 12 so as to be supplied with power from the DC power supply 30, but is supplied with power from the DC power supply 30. For example, a plurality of power feeding portions such as bumps and pads may be provided at the ends of the electrodes 121 in the longitudinal direction facing each other in the pair of adjacent electrodes 121 in the plurality of electrodes 121. By connecting the switching element 21 to the power feeding unit, the power from the DC power supply 30 can be alternately supplied to the ends of the plurality of electrodes 121 as described above.

  In the organic EL lighting panel 10 having such a configuration, the organic light emitting layer 13 emits light by supplying DC power between the plurality of electrodes 121 constituting the first electrode layer 12 and the second electrode layer 14. . The light emitted from the organic light emitting layer 13 is a surface on which the organic EL layer formed by sandwiching the organic light emitting layer 13 between the pair of first and second electrode layers 12 and 14, that is, the first electrode layer 12. Is emitted as output light of the organic EL lighting panel 10 from the other surface 112 (light emitting surface) opposite to the one surface 111 on which is formed.

  Here, since each electrode 121 of the first electrode layer 12 is made of a conductive transparent thin film such as ITO having a relatively high resistance, the end facing the longitudinal direction from the end of the anode feeding region 122. The luminance gradually decreases toward the part. However, in the pair of adjacent electrodes 121, power is supplied from the DC power supply 30 in each anode feeding region 122 at the end of the electrode 121 in the longitudinal direction facing each other. The decrease in luminance at the electrode 121 can be compensated by the luminance at the other electrode 121. For this reason, the luminance is averaged over the entire light emitting surface 112 of the organic EL lighting panel 10, and the luminance unevenness can be reduced. In particular, luminance unevenness can be effectively reduced for lighting with a relatively large light emitting surface area. Therefore, the luminance unevenness of the organic EL lighting device 1 using such an organic EL lighting panel 10 can also be reduced.

  In the case of dimming, a pair of adjacent electrodes 121 is taken as a set, and the power supply of the pair of electrodes 121 is controlled to be turned on / off by the drive unit 20, whereby a light emitting portion (light emitting portion) is emitted. The light emission amount of the organic EL lighting panel 10 can be adjusted step by step while reducing the luminance unevenness.

  For example, in the example shown in FIG. 1, since the first electrode layer 12 is composed of six electrodes 121-1 to 121-6, 100% light emission, 66.7% light emission, 33.3% light emission, and 0 The organic EL lighting panel 10 and the organic EL lighting device 1 can be dimmed in four stages of% light emission (off).

  In the case of 100% light emission, the dimming control unit 22 outputs a control signal for turning on the switching element 21 to each control terminal of all the switching elements 21-1 to 21-6. All the switching elements 21-1 to 21-6 are turned on by this control signal, and power is supplied from the DC power supply 30 to all the electrodes 121-1 to 121-6. As a result, the organic EL lighting panel 10 and the organic EL lighting device 1 emit 100%.

  In the case of 66.7% light emission, the dimming control unit 22 outputs a control signal to each control terminal of the four switching elements 21-2 to 21-5, for example. The four switching elements 21-2 to 21-5 are turned on by this control signal, and power is supplied from the DC power supply 30 to the four electrodes 121-2 to 121-5. As a result, the organic EL lighting panel 10 and the organic EL lighting device 1 emit light of 66.7%.

  Here, in the above description, the four switching elements 21-2 to 21-5 are turned on to emit light from the four electrodes 121-2 to 121-5 continuously located in the center. The combination of the switching elements 21 is not limited to this. For example, four switching elements 21-1 to 21- are arranged to emit light from four electrodes 121-1 to 121-4 (or four electrodes 121-3 to 121-6) that are continuously located from one side. 4 (or four switching elements 21-3 to 21-6) may be turned on, and the four electrodes 121-1, 121-2: 121-5, 121-6 located on both sides should be made to emit light. The four switching elements 21-1, 21-2; 21-5, 21-6 may be turned on.

  In the case of 33.3% light emission, the dimming control unit 22 outputs a control signal to each control terminal of the two switching elements 21-3 and 21-4, for example. By this control signal, the two switching elements 21-3 and 21-4 are turned on, and power is supplied from the DC power supply 30 to the two adjacent electrodes 121-3 and 121-4. Accordingly, the organic EL lighting panel 10 and the organic EL lighting device 1 emit 33.3%. Also in this case, the two electrodes 121 that emit light are not limited to the two electrodes 121-3 and 121-4. For example, other electrodes 121-2 and 121-3 are adjacent to each other. A combination may be used.

  In the case of 0% light emission (extinguishment), the dimming control unit 22 does not output a control signal for turning on the switching element 21 to each control terminal of all the switching elements 21-1 to 21-6. Accordingly, all the switching elements 21-1 to 21-6 are kept off, and power is not supplied from the DC power supply 30 to all the electrodes 121-1 to 121-6, and the organic EL lighting panel 10 and the organic EL The lighting device 1 emits light (turns off) 0%.

  By controlling the organic EL lighting panel 10 and the organic EL lighting device 1 in this way, the amount of light emission can be adjusted step by step while reducing the luminance unevenness in the light emitting portion on the light emitting surface.

  Such an organic EL lighting panel 10 is manufactured by the following steps, for example. First, an ITO first electrode layer 12 composed of a plurality of strip-shaped electrodes 121 is formed in a substantially central portion on a rectangular glass substrate 11. Next, the substrate 11 on which the ITO thin film of the first electrode layer 12 is formed is subjected to ultrasonic cleaning with acetone, isopropyl alcohol (both manufactured by Kanto Chemical Co., Ltd.), Semico Clean (manufactured by Furuuchi Kagaku), and ultrapure water, respectively. After washing, it is washed with isopropyl alcohol vapor and dried. Next, surface treatment of the substrate 11 on which the ITO thin film of the first electrode layer 12 is formed is performed by an atmospheric pressure plasma surface treatment apparatus (manufactured by Matsushita Electric Works Co., Ltd.).

  Next, using a mask for an organic light emitting layer having an opening, 4,4′-bis [N- (naphthyl) -N-phenyl-amino] biphenyl (α-NPD) was deposited, and Alq3 was doped with coumarin. Deposit a layer. Next, Alq3 is vapor-deposited and LiF is vapor-deposited. Thereby, the organic light emitting layer 13 is formed.

  Next, aluminum is vapor-deposited using the 2nd electrode mask which has an opening part, and the 2nd electrode layer 14 of aluminum is formed.

  Next, the cathode terminal 141 is connected to the second electrode layer 14, and a glass plate as the second sealing member 16 is adhered to the substrate 11 with an epoxy-based adhesive as the first sealing member 15, thereby hermetically sealing. To do. Thereby, the organic EL lighting panel 10 shown in FIG. 1 is manufactured.

It is a figure which shows the structure of the organic electroluminescent illuminating device which concerns on embodiment. It is a perspective view which shows the structure of the organic electroluminescent display of patent document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic EL lighting device 10 Organic EL lighting panel 11 Board | substrate 12 1st electrode layer 13 Organic light emitting layer 14 2nd electrode layer 15 1st sealing member 16 2nd sealing member 20 Drive part 21 Switching element 22 Dimming control part 30 DC power supply 121 Electrode 122 Anode feeding area

Claims (2)

An organic EL layer comprising at least one light-transmitting pair of first and second electrode layers sandwiching an organic light-emitting layer including at least a light-emitting layer is disposed on a light-transmitting substrate and cooperates with the substrate. In an organic EL lighting panel including a sealing member for sealing the organic EL layer,
The organic light emitting layer is a single layer corresponding to the entire light emitting surface ,
Wherein one of the first and second electrode layers, in the light-emitting surface side, consists a plurality of parallel linear or strip-shaped transparent electrodes to each other, each other in a pair of transparent electrodes adjacent in the plurality of transparent electrodes Power from the power supply is supplied at the opposite end,
The other of said 1st and 2nd electrode layers is a planar electrode corresponding to the said organic light emitting layer, The organic electroluminescent illumination panel characterized by the above-mentioned . The organic EL lighting panel according to claim 1;
A plurality of switching elements that are respectively inserted in the respective power supply lines in the plurality of electrodes and turn on and off the power from the power source;
An organic EL lighting device comprising: a dimming control unit that controls on / off of each of the plurality of switching elements.

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