JP2008198457A - Manufacturing method of light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the manufacturing costs of a tandem-type light-emitting device where a plurality of luminous unit layers are laminated. <P>SOLUTION: A donor film 10 is prepared, where a peel layer 12 and a luminous unit layer U are laminated on a base film 11. While the donor film 10 is in contact with an electrode 30 in a substrate 20, laser beams L are applied, and the luminous unit layer U is separated, thus transferring the first luminous unit layer U1 to the surface of the electrode 30. Then, while the donor film 10 is in contact with the surface of the first luminous unit layer U1, laser beams L are applied for transferring, thus laminating the second luminous unit layer U2 on the first luminous unit layer U1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light emitting device in which a plurality of light emitting unit layers each having a light emitting element such as an organic EL (Electroluminescence) element are stacked.

As a light-emitting device, for example, Patent Document 1 describes a light-emitting device in which a plurality of light-emitting units (light-emitting unit layers) are stacked (hereinafter referred to as “tandem light-emitting device”). Generally, the light emitting unit layer includes a light emitting layer made of a light emitting material such as an organic EL material, and an electrode sandwiching the light emitting layer. In the tandem light emitting device, since a plurality of light emitting unit layers are electrically connected in series, the light emission amount per unit time with respect to the same current is multiplied by the number of layers, and the light emission efficiency is dramatically improved. Since the lifetime of the light-emitting element is shortened according to the current density flowing through the element, the tandem light-emitting device can increase the luminance of the light-emitting device as a whole without reducing the lifetime of the light-emitting element.
JP 2005-285401 A

However, in the manufacture of a tandem light emitting device, it is necessary to repeatedly laminate each electrode layer of the light emitting unit layer and the light emitting layer, and thus the manufacturing cost is high.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a method for manufacturing a tandem light-emitting device capable of stacking a plurality of light-emitting unit layers at a low cost.

  In order to solve the above-described problem, in the method for manufacturing a tandem light emitting device according to the present invention, at least first and second light emitting unit layers are stacked, and each light emitting unit layer is formed on both the first electrode and the second electrode. A method of manufacturing a tandem light-emitting device having a sandwiched light-emitting layer, wherein each of the first electrode, the second electrode, and the light-emitting layer is formed of a light-transmitting material, the base film and a release layer And the light emitting unit layer are sequentially laminated, the surface of the transfer region on the substrate onto which the light emitting unit layer is transferred is brought into contact with the surface of the donor film on the light emitting unit layer side, and the donor film In a state where the transferred region is in contact, the donor film is irradiated with a laser beam, and the light emitting unit layer is peeled from the base film with the release layer as a boundary, whereby the first light emitting unit layer is removed from the transferred region. In the state where the first layer transfer step of transferring to the surface, the surface of the donor film on the light emitting unit layer side is brought into contact with the surface of the first light emitting unit layer, and the donor film and the first light emitting unit layer are in contact with each other. A second layer transfer step of transferring the second light emitting unit layer onto the first light emitting unit layer by irradiating the donor film with laser light and peeling the light emitting unit layer from the base film with the release layer as a boundary; Is provided.

  In the manufacturing method, a donor film including a light emitting unit layer is prepared, and a plurality of light emitting unit layers are stacked by repeatedly transferring the light emitting unit layer of the donor film to the substrate side, thereby manufacturing a tandem light emitting device. Therefore, for example, as compared with the case where each layer of the light emitting unit layer is formed one by one using a vapor deposition method, the manufacturing time is greatly shortened and the manufacturing is also simplified. Therefore, the manufacturing cost is reduced.

In a preferred aspect of the present invention, in the first layer transfer step, a plurality of irradiation regions are selectively irradiated with laser light, and the light emitting unit layer in the irradiation region is peeled from the base film, thereby The first light emitting unit layer is transferred, and in the second layer transfer step, the remaining region where the light emitting unit layer remains in the donor film used in the first layer transfer step is formed on the surface of the first light emitting unit layer. The second light emitting unit layer is transferred onto the first light emitting unit layer by contacting the plurality of irradiation regions with laser light selectively.
In this embodiment, after the light emitting unit layer is transferred from the donor film to form the first light emitting unit layer, the remaining light emitting unit layer of the same donor film is used to transfer the remaining light emitting unit layer. Thus, the second light emitting unit layer is formed. Therefore, for example, when 50% of the donor film is transferred as the first light emitting unit layer and the remaining 50% is transferred as the second light emitting unit layer, a two-layer tandem element can be manufactured with one donor film. Similarly, if the same donor film is used three times, a three-layer tandem element can be manufactured. Therefore, the material is not wasted. Thus, according to this aspect, since the tandem light emitting device is formed by the transfer method using the donor film, the material can be effectively used, and the manufacturing cost can be reduced.

  In another preferred aspect of the present invention, the donor film used in the first layer transfer step includes a first color light emitting layer that emits light in a first color, and the donor film used in the second layer transfer step includes: A second color light emitting layer that emits light in the second color and has a mixed color with the first color is white is included. The first color is, for example, blue, and the second color is, for example, orange. A light emitting device in which a blue light emitting layer and an orange light emitting layer are arranged in tandem by preparing donor films each of which includes a light emitting unit layer including a light emitting layer that emits light of each color and sequentially transferring them to a substrate. Can be manufactured. When blue and orange are mixed, it becomes white, so that it is possible to easily manufacture a light emitting device that outputs white light.

  In another preferred aspect of the present invention, a color filter substrate on which a color filter is formed is used as the substrate. According to this aspect, since it is not necessary to provide an element substrate, the manufacturing cost is further reduced.

  The present invention is also grasped as an illuminating device, an image forming apparatus (printing apparatus), or an electronic device including any of the tandem light emitting devices manufactured by the manufacturing method. According to the present invention, an effect similar to any of the effects related to the manufacturing method according to each aspect described above is achieved.

Embodiments according to the present invention will be described below with reference to the accompanying drawings. In the drawings, the ratio of dimensions of each part is appropriately changed from the actual one.
<A-1: First Embodiment>
1 to 3 are cross-sectional views showing a manufacturing process of a tandem light emitting device 100 (hereinafter simply referred to as “light emitting device 100”) according to the first embodiment of the present invention. As shown in FIG. 3G, in the light emitting device 100 of the present embodiment, two layers of light emitting unit layers RU, GU, and BU for each of RGB are stacked on the substrate 20. Specifically, red light emitting unit layers RU1 and RU2 are stacked in the region RA, green light emitting unit layers GU1 and GU2 are stacked in the region GA, and blue light emitting unit layers BU1 and BU2 are stacked in the region BA. . An electrode 30 to which a high potential VEL is applied is formed between the first light emitting unit layer U1 (RU1, GU1, BU1) of the first layer and the substrate 20. Further, an extraction wiring 40 to which the low potential VGD is applied is formed above the second light emitting unit layer U2 (RU2, GU2, BU2) of the second layer. In these figures, only three regions are shown for the sake of simplicity of explanation, but there may be many light emitting regions. The same applies to the other drawings.

  In the present embodiment, each electrode 30 has a stripe shape with the Y direction in the drawing as the longitudinal direction. On the other hand, the lead-out wiring 40 is formed in a stripe shape whose longitudinal direction is the X direction so as to cross the electrode 30 at right angles. Each electrode 30 and extraction wiring 40 are selected in time series (voltage is applied), and current flows only in the light emitting unit layer U where the selected electrode 30 and extraction wiring 40 intersect at a certain time. Only the light emitting layer sandwiched between the portions emits light. Therefore, the light emitting device 100 of this embodiment is a light emitting device driven by a simple matrix method.

  As shown in FIG. 1A, in the method of manufacturing the light emitting device 100, first, the donor film 10 (10G in the illustrated example) including the light emitting unit layer U (the green light emitting unit layer GU in the illustrated example). And a substrate 20 having a plurality of electrodes 30 formed on the surface thereof.

  The donor film 10 is obtained by sequentially laminating a base film 11, a release layer 12, and a light emitting unit layer U. The base film 11 is made of a transparent polymer film such as polycarbonate (PC), polyethylene terephthalate (PET), polyester, polyacryl, epoxy resin, polyethylene, polystyrene, or polyether sulfone. As a film thickness of the base film 11, 10-600 micrometers is preferable and 50-200 micrometers is especially preferable.

  The release layer 12 is in contact with the base film 11, is formed on the light-to-heat conversion layer for absorbing light and generating heat efficiently, and on the light emitting unit layer U side with respect to the light-to-heat conversion layer, for efficient transfer It includes a heat propagation layer that propagates heat. The photothermal conversion layer is, for example, an organic film in which a metal film made of aluminum, an oxide thereof and / or a sulfide thereof, carbon black, graphite, or an infrared dye is dispersed in a polymer material. An example of the heat propagation layer is a polymer material such as poly α-methylstyrene.

  The light emitting unit layer U includes a cathode 13, an electron injection layer 14, a light emitting layer 15, a hole transport layer 16, a hole injection layer 17, and an anode 18. However, at least the light emitting layer 15 is preferably disposed between the cathode 13 and the anode 18. As the light emitting material of the light emitting layer 15, a known light emitting material for organic EL is used. An electron transport layer (not shown) may be provided between the electron injection layer 14 and the light emitting layer 15. Further, a hole blocking layer or an electron blocking layer that prevents holes or electrons from leaking from the light emitting layer 15 may be provided. Examples of the anode 18 include ITO (Indium Tin Oxide), IZO (registered trademark) (Indium Zinc Oxide), IGO (Indium Germanium Oxide), and the like. The transparent conductive material can be used. The cathode 13 has two layers although not shown. The first layer is formed from a material having a low work function, such as calcium, with a very thin thickness, and the second layer is formed from a transparent material such as ITO, IZO, or IGO. The first layer is in contact with the electron injection layer 14, and the second layer is disposed on the opposite side of the electron injection layer 14 with the first layer interposed therebetween. Both the first layer and the second layer can be formed by a deposition method such as vapor deposition. When the first layer is formed from calcium, the second layer is formed after the calcium thin film (first layer), so that calcium is oxidized by oxygen contained in the second layer, and the cathode 13 is transparent and It becomes a cathode excellent in electron injectability.

  Each layer of the light emitting unit layer U and the release layer 12 are preferably formed of a light transmissive material. As a result, in a tandem configuration in which a plurality of sets are stacked to emit light, light emitted from each light emitting layer 15 is transmitted.

  In the present embodiment, a red light emitting unit layer RU including a light emitting layer 15R that emits light in R color, a green light emitting unit layer GU that includes a light emitting layer 15G that emits light in G color, and a blue light emitting unit that includes a light emitting layer 15B that emits light in B color. Three types of donor films 10R, 10G, and 10B including any of the layers BU are prepared. As shown in FIG. 1A, in this embodiment, a donor film 10G is prepared first.

As described above, the electrode 30 is formed in a stripe shape on the surface of the substrate 20. In each of FIGS. 1 to 3, three electrodes 30 are illustrated. The three electrodes 30 include a striped region RA in which a red light emitting unit layer RU including a light emitting layer 15R that emits light in R color is stacked, and a green light emitting unit layer GU that includes a light emitting layer 15G that emits light in G color. The stripe-shaped region GA to be stacked and the blue light-emitting unit layer BU including the light-emitting layer 15B that emits light of B color are respectively formed in the stripe-shaped region BA. A terminal to which a high potential power supply VEL is input is connected to the end of each electrode 30.
As the substrate 20, for example, a light transmissive material such as glass is used. As the electrode 30, for example, a transparent conductive material such as ITO, IZO, or IGO is used. Therefore, the light emitting device 100 of the present embodiment is a bottom emission type light emitting device.
1 to 3, only the three electrodes 30 and the light emitting unit layer U are shown. However, in actuality, the number of electrodes corresponding to the resolution (more precisely, the number of pixels in the X direction) is shown. An electrode and a light emitting unit layer U are formed.

  Next, as shown in FIG. 1B, the green light emitting unit layer GU of the donor film 10 </ b> G is brought into contact with the surface of the electrode 30. In a state where both are in contact with each other, the laser beam L is irradiated to the stripe-shaped region GA while pressing the surface opposite to the electrode forming surface of the substrate 20 or the surface on the base film 11 side of the donor film 10G. To do. In this embodiment, a laser transfer (LITI: Light Induced Thermal Imaging) method using YAG (Yttrium Aluminum Garnet) laser light is used. In this LITI method, the laser light L is converted into heat by the photothermal conversion layer included in the release layer 12, and the green light emitting unit layer GU heated by this heat is released and transferred to the substrate 20 side. The laser beam L is preferably irradiated with a 14 W YAG laser beam split by a diffraction grating.

As a result, as shown in FIG. 1C, when the donor film 10G is separated from the substrate 20 (moved in the direction of arrow A), only the region corresponding to the region GA in the green light emitting unit layer GU is an electrode. It stays in a state where it is crimped to 30. Here, the bonding surface between the anode 18 and the electrode 30 of the green light emitting unit layer GU is formed clean and smooth. Therefore, the anode 18 and the electrode 30 are pressure-bonded without using a conductive adhesive, and sufficient conduction can be obtained only by this pressure-bonding. The release layer 12 is formed after the light emitting unit layer U is peeled off by irradiation with a laser beam L described later from the viewpoint of reducing the resistance between the bonding surfaces of the transfer layer (the light emitting unit layer U) and the transferred layer. Is preferably formed of a material that does not remain. However, even if it remains, since it contains a conductive material such as carbon black, there is little resistance to current between layers, and there is little risk of causing a problem in light emission performance.
In this way, the first green light emitting unit layer GU1 is formed.

  On the other hand, in the green light emitting unit layer GU, the remaining region excluding the region corresponding to the region GA is separated from the substrate 20 together with the donor film 10G. Next, as shown in FIG. 2D, the donor film 10G having a remaining region is moved in the direction of arrow B, and the remaining region is moved to the surface (peeling layer 12) of the first layer (green light emitting unit layer GU1). Is left in contact with the surface of the release layer 12. Subsequently, in a state where the remaining region and the first layer are in contact with each other, the LITI method is applied to the region GA while pressing the surface opposite to the electrode forming surface of the substrate 20 or the surface on the base film 11 side of the donor film 10G. The laser beam L is irradiated using Subsequently, when the donor film 10G is separated from the substrate 20 (moved in the direction of arrow A), only the region corresponding to the region GA in the green light emitting unit layer GU is pressure-bonded to the first green light emitting unit layer GU1 or the release layer 12. In this state, the second green light emitting unit layer GU2 is formed.

  In manufacturing a tandem light-emitting device, in addition to the above-described manufacturing method (transfer method), for example, a method of forming each layer of an electrode layer (anode and cathode) and a light-emitting layer one by one using a vapor deposition method is conceivable. However, in the manufacturing method of the embodiment, the donor film 10 including the light emitting unit layer U is prepared, and the light emitting unit layer U is laminated by repeatedly transferring the light emitting unit layer U of the donor film 10 onto the substrate 20. Therefore, compared with the case where each layer of the light emitting unit layer U is formed one by one, the manufacturing time is greatly shortened and the manufacturing is also simplified. Therefore, the manufacturing cost is reduced.

  For example, in the vapor deposition method using masking, the material adhering to the mask is wasted. However, in the manufacturing method described above, after the light emitting unit layer U is transferred from the donor film 10 to form the first light emitting unit layer U1, the remaining region where the light emitting unit layer U of the same donor film 10 remains is used. Then, the remaining light emitting unit layer U is transferred to form the second light emitting unit layer U2. Therefore, for example, if 50% of the donor film is transferred as the first light emitting unit layer and the remaining 50% is transferred as the second light emitting unit layer, a two-layer tandem element can be manufactured with one donor film. Is not wasted. Thus, according to the manufacturing method of the present embodiment, the tandem light-emitting device is formed by the transfer method using the donor film 10, so that the material can be used effectively and the manufacturing cost is reduced.

  Next, using the donor film 10R including the red light emitting unit layer RU, the same steps as those shown in FIGS. 1A to 1C and FIG. 2D are repeated. As a result, as shown in FIG. 2E, the first red light emitting unit layer RU1 and the second red light emitting unit layer RU2 are sequentially stacked on the electrode 30 in the region RA. Similarly, steps similar to those shown in FIGS. 1A to 1C and FIG. 2D are repeated using the donor film 10B including the blue light emitting unit layer BU corresponding to the B color. As a result, as shown in FIG. 3F, the first blue light emitting unit layer BU1 and the second blue light emitting unit layer BU2 are sequentially stacked on the electrode 30 in the region BA.

Subsequently, as shown in FIG. 3G, the extraction wiring 40 is formed on the surface of the second light emitting unit layer U2. FIG. 4 is an enlarged cross-sectional view showing a state in which the extraction wiring 40 is disposed. As shown in FIG. 4, an input terminal 40 a to which a low potential power supply VGD is applied is formed at the end of the substrate 20. As described above, the extraction wiring 40 is formed so as to orthogonally intersect the light emitting unit layer U, and its end is connected to the input terminal 40a. Since the light emitting device 100 of this embodiment is a bottom emission type, a conductive metal material such as aluminum is used for the lead-out wiring 40.
It is preferable that the region M sandwiched between the electrode 30 and the input terminal 40a in the surface of the substrate 20 is filled with an insulating material. As the insulating material, epoxy resin, polyimide resin, silicon nitride, or the like can be used.

Next, as shown in FIG. 3G and FIG. 4, the entire two light emitting unit layers U formed for each color of RGB are sealed using a sealing can 60. At this time, the desiccant 50 is disposed inside the sealing can 60.
In this way, the tandem light emitting device 100 is manufactured.

  As described above, in the manufacturing method of the tandem light emitting device of this embodiment, the light emitting unit layer U is transferred onto the substrate 10 from the donor film 10 using a transfer method. Therefore, the manufacturing process is simplified as compared with a case where electrode layers such as an anode and a cathode and a light emitting layer are formed one by one. Moreover, since the second layer is transferred using the remaining region of the light emitting unit layer U, the material can be effectively used. Therefore, the manufacturing cost is reduced.

<A-2: Modification of First Embodiment>
In the first embodiment, the bottom emission type light emitting device 100 has been described. However, a top emission type light emitting device may be used. FIG. 5 is a cross-sectional view of a light emitting device 100A as a modification of the first embodiment.
As shown in FIG. 5, the light emitting device 100 </ b> A according to the present modification uses a substrate 20 having a reflective electrode 30 a, which is a light reflective conductive material, instead of the electrode 30 on the surface of the substrate 20. An example of the reflective electrode 30a is aluminum. Further, as the substrate 20, for example, a transparent substrate such as glass, an opaque substrate obtained by coating an insulating material on a metallic substrate such as ceramic, aluminum, or iron may be used.

  On the substrate 20 on which the reflective electrode 30a is formed, the two light emitting unit layers U1 and U2 are transferred using the transfer method described above, and the lead-out wiring 40 is formed on the second light emitting unit layer U2. . As the lead-out wiring 40, a light transmissive conductive material such as ITO is used. Subsequently, the surface of the substrate 20 and the entire surface of the two light emitting unit layers are formed so as to be covered with the thin film sealing layer 80. As the thin film sealing layer 80, silicon oxynitride (SiON) having high transparency and good moisture resistance is used. Next, a resin layer 90 as an adhesive is disposed so as to cover the thin film sealing layer 80, and a transparent sealing substrate is bonded to the upper part thereof. According to this modification, the same effect as the first embodiment is achieved.

<B-1: Second Embodiment>
6 to 8 are cross-sectional views illustrating manufacturing steps of the tandem light emitting device according to the second embodiment of the present invention.
As shown in FIG. 8F, the tandem light emitting device 200 according to the second embodiment includes a color filter substrate 70a on which a color filter 70 is formed instead of the substrate 20 in the first embodiment. Use. In the first embodiment, a tandem element is formed by overlapping two layers of the same light emitting unit layers RU, GU, BU for each of the regions RA, GA, BA. However, the light emitting device 200 of the present embodiment is used. , A blue light emitting unit layer BU is used as the first light emitting unit layer U1, and an orange light emitting unit layer RgU is stacked thereon as the second light emitting unit layer U2, whereby a blue light emitting unit layer BU and an orange light emitting unit layer are stacked. White light is obtained by mixing with RgU. White light is transmitted through the color filter 70 and emitted.
The light emitting device 200 has the same configuration as the light emitting device 100 of the first embodiment except for the points described above. Therefore, in FIGS. 6-8, the same reference number is used for a common element, and the description thereof is omitted as appropriate.

  First, as shown in FIG. 6A, a color filter substrate 70a on which a color filter 70 is formed and a blue donor film 10B are prepared. As the color filter substrate 70a, for example, a light transmissive material such as glass is used. A black matrix BM is formed in a grid pattern on the surface of the color filter substrate 70a, and an R color filter 70R, a G color filter 70G, and a B color filter 70B are formed in each window of the grid of the black matrix BM. Either is formed. An electrode 30 is formed on the upper layer of the R color filter 70R, the G color filter 70G, and the B color filter 70B.

  The blue donor film 10B includes a base film 11, a release layer 12, and a blue light emitting unit layer BU. The blue light emitting unit layer BU emitting blue light includes a cathode 13, an electron injection layer 14, and a blue light emitting layer 15B. , A hole transport layer 16, a hole injection layer 17, and an anode 18.

  Next, as shown in FIG. 6B, the blue light emitting unit layer BU of the donor film 10 </ b> B is brought into contact with the surface of the electrode 30. Then, in a state where both are in contact with each other, while pressing the surface on the opposite side of the color filter substrate 70a or the surface on the base film 11 side of the donor film 10B, all the regions RA, GA, BA are used as the irradiation regions. Irradiate light L.

  As a result, as shown in FIG. 7C, when the donor film 10B is separated from the color filter substrate 70a (moved in the direction of arrow A), the regions RA, GA, and BA of the blue light emitting unit layer BU. Only the region corresponding to is left in a state where it is crimped to the electrode 30. In this manner, the blue light emitting unit layer BU is formed as the first light emitting unit layer U1.

  Next, an orange donor film 10Rg is prepared. The orange light emitting unit layer RgU of the orange donor film 10Rg includes an orange light emitting layer 15Rg that emits orange light instead of the blue light emitting layer 15B.

  Next, as shown in FIG. 7D, the anode 18 of the orange donor film 10Rg is abutted against the surface of the blue light emitting unit layer BU or the release layer 12. Then, in a state where both are in contact, the laser beam is applied to all the regions RA, GA, and BA while pressing the surface on the opposite side of the color filter substrate 70a or the surface on the base film 11 side of the donor film 10Rg. L is irradiated. As a result, as shown in FIG. 8E, when the donor film 10Rg is separated from the blue light emitting unit layer BU (moved in the direction of the arrow A), the regions RA, GA, BA of the orange light emitting unit layer RgU are separated. Only the region corresponding to is left in a state where it is pressed against the blue light emitting unit layer BU. In this way, the orange light emitting unit layer RgU is formed as the second light emitting unit layer U2.

Subsequently, as shown in FIG. 8F, after forming the extraction wiring 40 on the upper surface portion of the orange light emitting unit layer RgU, two layers formed for each color of RGB using the sealing can 60 are used. The entire light emitting unit layer U is sealed. At this time, the desiccant 50 is disposed inside the sealing can 60.
In this way, the tandem light emitting device 200 is manufactured.

  As described above, in the manufacturing method of the tandem light emitting device in this embodiment, it is possible to obtain the same effects as those in the first embodiment described above. In the present embodiment, the blue donor film 10B and the orange donor film 10Rg are prepared, and the light emitting device in which the blue light emitting layer and the orange light emitting layer are arranged in tandem is sequentially transferred to the color filter 70. Can be manufactured. When blue and orange are mixed, it becomes white, so that it is possible to easily manufacture a light emitting device that outputs white light.

  In addition, when forming each electrode layer and a light emitting layer on an element substrate (for example, the substrate 20 of the first embodiment) and forming a color filter on the opposite side of the element substrate with the light emitting layer interposed therebetween, It is necessary to use both the element substrate and the color filter substrate 70a. However, in this embodiment, since the color filter substrate 70a on which the color filter is formed is used instead of the element substrate, it is not necessary to provide the element substrate, and the manufacturing cost is further reduced.

<B-2: Modification of Second Embodiment>
In the second embodiment, the bottom emission type light emitting device 200 has been described. However, a top emission type light emitting device may be used. FIG. 9 is a cross-sectional view of a light emitting device 200A as a modification of the second embodiment.
As shown in FIG. 9, the light emitting device 200 </ b> A according to the present modification uses a surface of the substrate 20 in which a reflective electrode 30 a that is a light reflective conductive material is formed instead of the electrode 30. On the substrate 20 on which the reflective electrode 30a is formed, the two light emitting unit layers BU and RgU are transferred using the transfer method described above, and an extraction wiring 40 is formed on the orange light emitting unit layer RgU. Subsequently, the thin film sealing layer 80 is formed so as to cover the surface of the substrate 20 and the entire surface of the two light emitting unit layers. Next, a resin layer 90 is formed so as to cover the thin film sealing layer 80, and a color filter substrate 70a on which the black matrix BM and the color filters 70R, 70G, and 70B are formed is adhered to the resin layer 90. According to this modification, the same effect as the above embodiment is achieved.

<C: Modification>
(1) In the first and second embodiments described above, a mode has been described in which a plurality of light emitting elements (for example, pixels) whose emission luminances are individually controlled are formed on the substrate 20 or the color filter substrate 70a. It is good also as an aspect which forms a light emitting element uniformly in the whole board | substrate.
FIG. 10 is a cross-sectional view of a tandem light emitting device 300 according to this modification. As shown in FIG. 10, the light emitting device 300 includes a substrate 20 on which the electrode 30 is formed, a first light emitting unit layer U1 and a second light emitting unit layer U2, and an extraction wiring 40, and a desiccant. 50 is sealed by a sealing can 60 enclosed.
In manufacturing the light emitting device 300, the donor film 10 including the first light emitting unit layer U1 is prepared, and the laser light L is applied to the region RW in a state where the first light emitting unit layer U1 of the donor film 10 is pressed against the electrode 30. , The first light emitting unit layer U1 is transferred. Next, the donor film 10 including the second light emitting unit layer U2 is prepared, and the laser light is applied to the region RW in a state where the second light emitting unit layer U2 of the donor film 10 is pressed against the upper surface of the first light emitting unit layer U1. By irradiating L, the second light emitting unit layer U2 is transferred.
For example, when the blue light emitting unit layer BU is used as the first light emitting unit layer U1 and the orange light emitting unit layer RgU is used as the second light emitting unit layer U2, for example, both colors are mixed and white light is generated. The light-emitting device 300 can be used as a lighting device.
According to this embodiment, it is possible to obtain the same effect as that of the above-described embodiment.

  (2) In the first and second embodiments described above, the light emitting devices 100, 100A, 200, and 200A that output light of three colors of RGB have been described. However, a light emitting device that outputs single color light may be used. In the second embodiment, the white light is obtained by stacking the blue light emitting unit layer BU and the orange light emitting unit layer RgU. However, instead of the orange light emitting unit layer RgU, the light emitted from the blue light emitting layer 15B Other materials from which a white color can be obtained by mixing these colors, for example, a yellow light emitting material, may be used. Or it is good also as a structure which obtains white emitted light by laminating | stacking three layers of red light emission unit layer RU, green light emission unit layer GU, and blue light emission unit layer BU. In the above-described embodiment, the light emitting devices 100, 100A, 200, and 200A are driven by the simple matrix driving method. However, the present invention is not limited to this, and an active matrix driving method may be used. In that case, an active element such as a thin film transistor (TFT) may be formed on the substrate 20.

  (3) In the first and second embodiments described above, the method for manufacturing the tandem light emitting device in which the two light emitting unit layers U are stacked has been described. However, the method is not limited to two layers, and three or more light emitting unit layers are formed. It may be a light emitting device.

<D: Image forming apparatus>
The light emitting devices 100, 100A, 200, 200A in the above-described embodiments can be used as a line-type optical head for writing a latent image on an image carrier in an image forming apparatus using an electrophotographic method. Examples of the image forming apparatus include a printer, a printing part of a copying machine, and a printing part of a facsimile. FIG. 11 is a longitudinal sectional view showing an example of an image forming apparatus using the optical head 1A as a line type optical head. This image forming apparatus is a tandem type full color image forming apparatus using a belt intermediate transfer body system.

  In this image forming apparatus, four organic EL arrays 10K, 10C, 10M, and 10Y having the same configuration are exposed to four photosensitive drums (image carriers) 110K, 110C, 110M, and 110Y having the same configuration. It is arranged at each position. The organic EL arrays 10K, 10C, 10M, and 10Y are the light emitting devices 100, 100A, 200, and 200A according to the embodiments exemplified above.

  As shown in FIG. 11, the image forming apparatus is provided with a driving roller 121 and a driven roller 122. An endless intermediate transfer belt 120 is wound around these rollers 121 and 122, and an arrow indicates As shown, the periphery of the rollers 121 and 122 is rotated. Although not shown, tension applying means such as a tension roller that applies tension to the intermediate transfer belt 120 may be provided.

  Around the intermediate transfer belt 120, four photosensitive drums 110K, 110C, 110M, and 110Y each having a photosensitive layer on the outer peripheral surface are arranged at a predetermined interval. The subscripts K, C, M, and Y mean that they are used to form black, cyan, magenta, and yellow visible images, respectively. The same applies to other members. The photosensitive drums 110K, 110C, 110M, and 110Y are rotationally driven in synchronization with the driving of the intermediate transfer belt 120.

  Around each photosensitive drum 110 (K, C, M, Y), there is a corona charger 111 (K, C, M, Y), an organic EL array 10 (K, C, M, Y), and development. A device 114 (K, C, M, Y) is arranged. The corona charger 111 (K, C, M, Y) uniformly charges the outer peripheral surface of the corresponding photosensitive drum 110 (K, C, M, Y). The organic EL array 10 (K, C, M, Y) writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum. Each organic EL array 10 (K, C, M, Y) is installed such that the arrangement direction of the plurality of light emitting elements P is along the bus (main scanning direction) of the photosensitive drum 110 (K, C, M, Y). Is done. The electrostatic latent image is written by irradiating the photosensitive drum with light by the plurality of light emitting elements P described above. The developing device 114 (K, C, M, Y) forms a visible image, that is, a visible image on the photosensitive drum by attaching toner as a developer to the electrostatic latent image.

  The black, cyan, magenta, and yellow developed images formed by the four-color single-color image forming station are sequentially transferred onto the intermediate transfer belt 120 to be superimposed on the intermediate transfer belt 120. As a result, a full-color image is obtained. Four primary transfer corotrons (transfer devices) 112 (K, C, M, Y) are arranged inside the intermediate transfer belt 120. The primary transfer corotron 112 (K, C, M, Y) is disposed in the vicinity of the photosensitive drum 110 (K, C, M, Y), and the photosensitive drum 110 (K, C, M, Y). The electrostatic image is electrostatically attracted from the toner image to transfer the visible image to the intermediate transfer belt 120 passing between the photosensitive drum and the primary transfer corotron.

  A sheet 102 as an object on which an image is to be finally formed is fed one by one from the sheet feeding cassette 101 by the pickup roller 103, and between the intermediate transfer belt 120 and the secondary transfer roller 126 in contact with the driving roller 121. Sent to the nip. The full-color visible image on the intermediate transfer belt 120 is secondarily transferred to one side of the sheet 102 by the secondary transfer roller 126 and fixed on the sheet 102 through the fixing roller pair 127 as a fixing unit. . Thereafter, the sheet 102 is discharged onto a paper discharge cassette formed in the upper part of the apparatus by a paper discharge roller pair 128.

Next, another embodiment of the image forming apparatus according to the present invention will be described.
FIG. 12 is a longitudinal sectional view of another image forming apparatus using the light emitting devices 100, 100A, 200, and 200A as a line type optical head. This image forming apparatus is a rotary developing type full-color image forming apparatus using a belt intermediate transfer body system. In the image forming apparatus illustrated in FIG. 12, a corona charger 168, a rotary developing unit 161, an organic EL array 167, and an intermediate transfer belt 169 are provided around the photosensitive drum 165.

  The corona charger 168 uniformly charges the outer peripheral surface of the photosensitive drum 165. The organic EL array 167 writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum 165. The organic EL array 167 is the optical head 1 </ b> A of the embodiment exemplified above, and is installed so that the arrangement direction of the plurality of light emitting elements is along the bus line (main scanning direction) of the photosensitive drum 165. The electrostatic latent image is written by irradiating the photosensitive drum 165 with light from these light emitting elements.

  The developing unit 161 is a drum in which four developing units 163Y, 163C, 163M, and 163K are arranged at an angular interval of 90 °, and can rotate counterclockwise about the shaft 161a. The developing units 163Y, 163C, 163M, and 163K supply yellow, cyan, magenta, and black toners to the photosensitive drum 165, respectively, and attach the toner as a developer to the electrostatic latent image, thereby the photosensitive drum 165. A visible image, that is, a visible image is formed.

  The endless intermediate transfer belt 169 is wound around a driving roller 170a, a driven roller 170b, a primary transfer roller 166, and a tension roller, and is rotated around these rollers in a direction indicated by an arrow. The primary transfer roller 166 transfers the visible image to the intermediate transfer belt 169 that passes between the photosensitive drum and the primary transfer roller 166 by electrostatically attracting the visible image from the photosensitive drum 165.

  Specifically, in the first rotation of the photosensitive drum 165, an electrostatic latent image for a yellow (Y) image is written by the organic EL array 167, and a developed image of the same color is formed by the developing device 163Y. The image is transferred to the intermediate transfer belt 169. In the next rotation, an electrostatic latent image for a cyan (C) image is written by the organic EL array 167, and a developed image of the same color is formed by the developing device 163C. The image is transferred to the transfer belt 169. Then, during the four rotations of the photosensitive drum 165, yellow, cyan, magenta, and black visible images are sequentially superimposed on the intermediate transfer belt 169. As a result, a full-color visible image is formed on the transfer belt 169. It is formed. When images are finally formed on both sides of a sheet as an object on which an image is to be formed, the same color images of the front and back surfaces are transferred to the intermediate transfer belt 169, and then the front and back surfaces are transferred to the intermediate transfer belt 169. A full-color visible image is obtained on the intermediate transfer belt 169 by transferring the visible image of the next color.

  The image forming apparatus is provided with a sheet conveyance path 174 through which a sheet passes. The sheets are picked up one by one from the paper feed cassette 178 by the pick-up roller 179, advanced through the sheet transport path 174 by the transport roller, and between the intermediate transfer belt 169 and the secondary transfer roller 171 in contact with the drive roller 170a. Pass through the nip. The secondary transfer roller 171 transfers the developed image to one side of the sheet by electrostatically attracting a full-color developed image from the intermediate transfer belt 169 collectively. The secondary transfer roller 171 can be moved closer to and away from the intermediate transfer belt 169 by a clutch (not shown). The secondary transfer roller 171 is brought into contact with the intermediate transfer belt 169 when a full-color visible image is transferred onto the sheet, and is separated from the secondary transfer roller 171 while the visible image is superimposed on the intermediate transfer belt 169.

  The sheet on which the image has been transferred as described above is conveyed to the fixing device 172 and is passed between the heating roller 172a and the pressure roller 172b of the fixing device 172, whereby the visible image on the sheet is fixed. The sheet after the fixing process is drawn into the discharge roller pair 176 and proceeds in the direction of arrow F. In the case of double-sided printing, after most of the sheet passes through the paper discharge roller pair 176, the paper discharge roller pair 176 is rotated in the reverse direction and introduced into the double-sided printing conveyance path 175 as indicated by an arrow G. The Then, the visible image is transferred to the other surface of the sheet by the secondary transfer roller 171, the fixing process is performed again by the fixing device 172, and then the sheet is discharged by the discharge roller pair 176.

  Since the image forming apparatus illustrated in FIGS. 11 and 12 uses the light emitting element as the exposure means, the apparatus can be made smaller than when the laser scanning optical system is used. Note that the light-emitting device of the present invention can also be adopted in an electrophotographic image forming apparatus other than those exemplified above. For example, the optical head in the above aspect can be applied to an image forming apparatus that transfers a visible image directly from a photosensitive drum to a sheet without using an intermediate transfer belt, and an image forming apparatus that forms a monochrome image. Is possible.

  Further, the image forming apparatus to which the optical head in the above aspect is applied is not limited to the image forming apparatus. For example, the light emitting device of the present invention is also used as a lighting device in various electronic devices. Examples of such electronic devices include facsimile machines, copiers, multifunction machines, and printers. For these electronic devices, a light emitting device in which a plurality of light emitting elements are arranged in a planar shape is suitably employed.

<E: Image reading device>
FIG. 13 is a longitudinal sectional view showing an example of an image reading apparatus using the light emitting devices 100, 100A, 200, and 200A of the embodiment as a line type optical head. A flat platen glass 202 is provided on the upper part of the cabinet 201 of the image reading apparatus, and a document 203 is placed on the platen glass 202 with its image surface facing downward. A platen cover (not shown) presses the document 203 toward the platen glass 202.

  Inside the cabinet 201, a high speed carriage 204 and a low speed carriage 205 are arranged so as to be movable in the horizontal direction. An organic EL array exposure head 206 that irradiates the original 203 and a reflecting mirror 207 are mounted on the high-speed carriage 204, and two reflecting mirrors 208 and 209 are mounted on the low-speed carriage 205. These organic EL array exposure head 206 and reflecting mirrors 207, 208, and 209 extend in the direction perpendicular to the paper surface (main scanning direction) in FIG. The organic EL array exposure head 206 is installed so that the arrangement direction of the plurality of OLED elements is along the main scanning direction.

  A document reader 210 is disposed at a fixed position inside the cabinet 201. The document reader 210 includes an imaging lens 212 and a line sensor (light receiving device) 213 composed of a large number of photosensitive pixels (charge coupled devices). The line sensor 213 extends in the direction perpendicular to the paper surface (main scanning direction) in FIG. 17, and is installed such that the arrangement direction of the plurality of photosensitive pixels is along the main scanning direction.

Light emitted from the organic EL array exposure head 206 passes through the platen glass 202 and is reflected by the lower surface of the document 203. Reflected light from the original 203 is transmitted through the platen glass 202, reflected by the reflecting mirrors 207 to 209, and then imaged by the line sensor 213 by the imaging lens 212. The high-speed carriage 204 moves in the horizontal direction so that the entire surface of the original 203 is irradiated by the organic EL array exposure head 206, and the low-speed carriage 205 moves at half the speed of the high-speed carriage 204, The length of the reflected light path reaching 213 is kept constant.
As described above, the light emitting devices 100, 100A, 200, and 200A are used as the organic EL array exposure head 206 that is an illumination device of the image reading device.

  As described above, the image reading apparatus to which the light emitting devices 100, 100A, 200, and 200A can be applied has been exemplified. However, the light emitting devices 100, 100A, 200, and 200A can be applied to other image reading devices, and as such. Such an image forming apparatus is within the scope of the present invention. For example, the light receiving device may move together with the light emitting devices 100, 100A, 200, 200A, and 300 as an illumination device, or the light receiving device and the light emitting devices 100, 100A, 200, 200A, and 300 are fixed together to read an original or a document. The target may be moved and read.

<F: Electronic equipment>
Next, an electronic apparatus using the light emitting device according to the present invention will be described. FIG. 14 and FIG. 15 illustrate a form of an electronic apparatus that employs the light-emitting device according to any one of the above forms as a display device.

  FIG. 14 is a perspective view showing a configuration of a mobile personal computer employing a light emitting device. The personal computer 2000 includes a display device D that displays various images, and a main body 2010 on which a power switch 2001 and a keyboard 2002 are installed. As the display device D, the light emitting devices 100, 100A, 200, and 200A of the above embodiment are used. Since the light emitting devices 100, 100A, 200, and 200A use organic light emitting diode elements, it is possible to display an easy-to-see screen with a wide viewing angle.

  FIG. 15 is a perspective view illustrating a configuration of a mobile phone to which the light emitting device is applied. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and a display device D that displays various images. As the display device D, the light emitting devices 100, 100A, 200, and 200A of the above embodiment are used. By operating the scroll button 3002, the screen displayed on the display device D is scrolled.

  Note that electronic devices to which the light emitting device according to the present invention is applied include, in addition to the devices shown in FIGS. 14 and 15, personal digital assistants (PDAs), digital still cameras, televisions, video cameras, cars Examples include navigation devices, pagers, electronic notebooks, electronic papers, calculators, word processors, workstations, videophones, POS terminals, printers, scanners, copiers, video players, devices equipped with touch panels, and the like.

It is sectional drawing which shows the manufacturing process of the tandem light-emitting device 100 which concerns on 1st Embodiment of this invention. FIG. 11 is a cross-sectional view showing a manufacturing process of the light emitting device 100. FIG. 11 is a cross-sectional view showing a manufacturing process of the light emitting device 100. It is an expanded sectional view which shows a mode that the extraction wiring 40 was arrange | positioned. It is sectional drawing of 100 A of light-emitting devices as a modification of 1st Embodiment. It is sectional drawing which shows the manufacture process of the tandem type light-emitting device 200 which concerns on 2nd Embodiment of this invention. FIG. 11 is a cross-sectional view showing a manufacturing process of the light emitting device 200. FIG. 11 is a cross-sectional view showing a manufacturing process of the light emitting device 200. It is sectional drawing of 200 A of light-emitting devices as a modification of 2nd Embodiment. It is sectional drawing of the light-emitting device 300 as a modification. It is a longitudinal cross-sectional view which shows an example of the image forming apparatus using a light-emitting device. It is a longitudinal cross-sectional view which shows an example of another image forming apparatus using a light-emitting device. It is a longitudinal cross-sectional view which shows an example of the image reading apparatus using a light-emitting device. It is a perspective view which shows the structure of the mobile type personal computer which employ | adopted the light-emitting device. It is a perspective view which shows the structure of the mobile telephone to which the light-emitting device is applied.

Explanation of symbols

  10 (10R, 10G, 10B, 10Rg) ... Donor film, 11 ... Base film, 11 ... Base film, 12 ... Release layer, 13 ... Cathode, 14 ... Electron injection layer, 15 (15R, 15G, 15B, 15Rg) ... Light emitting layer, 16 ... hole transport layer, 17 ... hole injection layer, 18 ... anode, 20, 20a ... substrate, 30 ... electrode, 30a ... reflective electrode, 40 ... extraction wiring, 40a ... input terminal, 50 ... desiccant , 60 ... sealing can, 60a ... sealing substrate, 70 ... color filter (70R, 70G, 70B), 70a ... color filter substrate, 80 ... thin film sealing layer, 90 ... resin layer, 100, 100A, 200, 200A, 300 ... light emitting device, BM ... black matrix, M ... area, RA, GA, BA ... area, U, RU, GU, BU, RgU ... light emitting unit layer.

Claims (4)

At least first and second light-emitting unit layers are stacked, and each light-emitting unit layer has a light-emitting layer sandwiched between a first electrode and a second electrode, the first electrode, the second electrode, and the A method of manufacturing a tandem light emitting device in which each of the light emitting layers is formed of a light transmissive material,
Prepare a donor film in which a base film, a release layer and the light emitting unit layer are laminated in order,
The surface of the transfer region on the substrate onto which the light emitting unit layer is transferred is brought into contact with the surface of the donor film on the side of the light emitting unit layer, and the donor film and the transfer region are in contact with each other. A first layer transfer step of transferring the first light emitting unit layer onto the transferred region by peeling the light emitting unit layer from the base film with the release layer as a boundary;
The surface of the donor film on the side of the light emitting unit layer is brought into contact with the surface of the first light emitting unit layer, and the donor film is irradiated with laser light in a state where the donor film and the first light emitting unit layer are in contact with each other. A second layer transfer step of transferring the second light emitting unit layer onto the first light emitting unit layer by peeling the light emitting unit layer from the base film with a layer as a boundary. In the first layer transfer step, the first light emitting unit layer is transferred by selectively irradiating a plurality of irradiation regions with laser light and peeling the light emitting unit layers in the irradiation regions from the base film. ,
In the second layer transfer step, the remaining region of the donor film used in the first layer transfer step where the light emitting unit layer remains is brought into contact with the surface of the first light emitting unit layer, and the plurality of irradiated regions are formed. The method for manufacturing a tandem light-emitting device according to claim 1, wherein the second light-emitting unit layer is transferred onto the first light-emitting unit layer by selectively irradiating a laser beam. The donor film used in the first layer transfer step includes a first color light emitting layer that emits light in a first color,
2. The tandem light emitting device according to claim 1, wherein the donor film used in the second layer transfer step includes a second color light emitting layer that emits light of a second color and a color mixture with the first color is white. Method. The method for manufacturing a tandem light-emitting device according to claim 2, wherein a color filter substrate on which a color filter is formed is used as the substrate.

Images