JP2010055861A - Light-emitting device, and manufacturing method of light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device in which sufficient barrier characteristics are secured against moisture and gas even though a simple sealing process is used, a manufacturing method of this light-emitting device, the light-emitting device high in reliability in which this light-emitting device is integrated, and the manufacturing method of the light-emitting device. <P>SOLUTION: This has a substrate 2 having a cathode 3, a light-emitting part LS formed on the substrate 2 by using high polymer organic electroluminescent material, an anode 7 to cover this light-emitting part LS, and a sealing part 10 which is adhered at least to the anode 7, and covers a wider range than the anode 7. This is constituted of an ultraviolet ray curable resin, the whole sealing substrate 9 is adhered to a side opposite to an adhered part of the anode 7 to the sealing part 10, and a water-absorbing inorganic porous material (crystalline zeolite) is contained in the sealing part 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light-emitting device provided with an organic electroluminescence element and a method for manufacturing the light-emitting device. In addition, the present invention relates to an exposure device incorporating the light-emitting device and an image forming apparatus equipped with the exposure device.

  An electroluminescent element is a light-emitting device that uses electroluminescence of a solid fluorescent substance. Currently, an inorganic electroluminescent element using an inorganic material as a luminescent material has been put into practical use, and is used for backlights and flat displays of liquid crystal displays. Some applications are being developed. However, since the voltage required for light emission of the inorganic electroluminescent element is as high as 100 V or more and it is difficult to emit blue light, it is difficult to achieve full color using the three primary colors of RGB. In addition, since the inorganic electroluminescent element has a very large refractive index of the material used as a light emitter, it is strongly affected by total reflection at the interface, and the light extraction efficiency into the air for actual light emission is about 10 to 20%. It is difficult to achieve high efficiency.

On the other hand, research on electroluminescent devices using organic materials has attracted attention for a long time, and various studies have been made. However, since the luminous efficiency is very low, full-scale practical research has not progressed. However, in 1987, Kodak's C.I. W. Tang et al. Proposed an organic electroluminescence device having a function-separated stacked structure in which an organic material constituting a light-emitting layer is divided into a hole transport layer and a light-emitting layer, despite a low voltage of 10 V or less. not 1000 cd / m ² or more high luminance can be obtained revealed (non-Patent Document 1).

  Since then, organic electroluminescence elements have attracted a great deal of attention, and research on organic electroluminescence elements having a similar function-separated layered structure has been actively conducted, especially for the practical application of organic electroluminescence elements. High efficiency and longevity, which are indispensable for this, have been fully studied. In recent years, displays using organic electroluminescence elements have been realized.

  FIG. 9 is a cross-sectional view showing the structure of a conventional organic electroluminescence element.

  Hereinafter, the structure of a conventional general organic electroluminescence element will be described with reference to FIG.

As shown in FIG. 9, the organic electroluminescence element 11 is made of, for example, ITO (indium oxide (In ₂ O ₃ ) formed on a glass substrate 12 by sputtering, resistance heating vapor deposition, or the like with several percent tin oxide (SnO). ₂ ) is a compound to which is added an anode 13 made of a transparent conductive film such as Indium Tin Oxide), and N, N′− formed on the anode 13 by the resistance heating vapor deposition method. A hole transport layer 14 made of diphenyl-N, N′-bis (3-methylphenyl) -1, 1′-diphenyl-4,4′-diamine (hereinafter abbreviated as TPD), and the like; the organic material layer 15 made of 8-hydroxyquinoline Aluminum, which is formed by a resistance heating evaporation method on the layer 14 (hereinafter abbreviated as Alq ₃₎ , And a cathode 17 made of a metal film of 100 to 300 in the order of nanometers thick, which is formed by a resistance heating deposition method on the organic material layer 15.

  The hole transport layer 14 and the organic material layer 15 are collectively referred to simply as the light emitting layer 16 for convenience. In this case, the light emitting layer 16 includes, in addition to the hole transport layer 14 and the organic material layer 15, a hole injection layer, an electron injection layer, an electron transport layer, and an electron block layer (both not shown). May be. The following explanation is also based on this example.

  Reference numeral 18 denotes a sealing portion made of glass having a bathtub shape, for example. The sealing portion 18 is provided so as to cover at least the entire surface of the organic electroluminescence element 11, and the outer peripheral portion thereof is bonded to the glass substrate 12 or the like using an adhesive.

  When a direct-current voltage or direct current is applied via an electric circuit (not shown) with the anode 13 of the organic electroluminescence element 11 having the above configuration as a positive electrode and the cathode 17 as a negative electrode, the hole transport layer 14 is formed from the anode 13. Then, holes are injected into the organic material layer 15 and electrons are injected from the cathode 17 into the organic material layer 15. As a result, recombination of holes and electrons occurs in the organic material layer 15 constituting the light emitting layer 16 sandwiched between the anode 13 and the cathode 17, and the excitons generated thereby change from the excited state to the ground state. A light emission phenomenon occurs at the time of transition (in this way, a portion that is sandwiched between at least the anode 13 and the cathode 17 and substantially contributes to light emission is hereinafter referred to as a “light emitting portion”).

  And in such an organic electroluminescent element 11, the light radiate | emitted from the fluorescent substance in the organic material layer 15 which comprises a light emission part is radiate | emitted in all directions centering on a fluorescent substance, the hole transport layer 14, anode 13. The light is emitted from the light extraction direction (direction of the glass substrate 12) into the air via the glass substrate 12. Alternatively, the light is once reflected in the direction opposite to the light extraction direction, reflected by the cathode 17, and emitted to the air through the light emitting layer 16, the anode 13, and the glass substrate 12.

  As described above, the organic electroluminescence element 11 has a very simple structure, can be mass-produced, and attracts attention as a technology that can be expected to reduce the cost and increase the area of a display device such as a display. ing.

  On the other hand, however, one of the problems of the organic electroluminescence element 11 is that shrinkage (shrinking) of the light emitting region occurs over time when affected by moisture, and non-light emitting sites (dark spots) in the light emitting region. ) Is known to occur. In order to prevent the occurrence and expansion of shrinking and dark spots, it is necessary to keep the organic electroluminescent element 11 in a low humidity state. As described above, the organic electroluminescent element 11 is sealed by the sealing portion 18 such as glass. Methods such as sealing and maintaining the internal space of the sealed region in a vacuum state or filling with an inert gas of low humidity are used. In order to further enhance the sealing effect, a desiccant may be provided in the bathtub-like space.

  Recently, for example, a so-called gas barrier laminate having a laminated structure of an organic layer made of a resin and an inorganic layer made of a metal oxide or the like is used as the sealing portion 18 of the organic electroluminescence element 11. .

  As an example of such a gas barrier laminate, a manufacturing method disclosed in (Patent Document 1) is known. In (Patent Document 1), “(Omitted) Many studies have been made on inorganic films, single layers of organic films, or stacking of organic / inorganic film gas barrier layers. As a result, a metal oxide film, a metal nitride film or a metal film is provided on a substrate such as a film, and an organic layer made of a thermosetting resin is laminated thereon. In the gas barrier laminate having the second metal oxide film, the metal nitride film or the metal film, the first curing is performed in the range of 120 ° C. to 180 ° C. immediately after the organic layer as the intermediate layer is laminated. After the second metal oxide film, the metal nitride film, or the metal film is provided, the second thermosetting is performed in the range of 180 ° C. to 240 ° C., whereby an inorganic film, a single layer of the organic film, or an organic film / inorganic Film In such stacking the barrier layer is set to be able to obtain a gas barrier property expression is difficult.

As another approach related to the sealing technique, for example, a method for manufacturing a light emitting device disclosed in (Patent Document 2) is known. In (Patent Document 2), as a sealing adhesive for laminating the glass substrate 12 and the sealing portion 18, a photothermal conversion substance (that is, a substance that absorbs infrared rays or near infrared rays) into a thermosetting (or thermoplastic) resin. ) And irradiating a laser beam to this to locally heat the portion where the sealing portion is to be bonded, so that the organic electroluminescence device generally having only heat resistance of 100 ° C. to 120 ° C. is not damaged. It is said that sealing can be performed.
Tan (C.W. Tang), S.A. Vanslyke, "Appl. Phys. Lett." (USA), Vol. 51, 1987, p. 913 JP 2004-181793 A JP 2001-237066 A

  Organic electroluminescent elements have a simple manufacturing process, so light-emitting devices equipped with organic electroluminescent elements, mainly backlights for self-luminous displays and liquid crystal displays, surface-emitting illumination, and organic electroluminescent elements It is said that applications such as an exposure apparatus that employs as a light source are advantageous for cost reduction.

  However, in the manufacturing process, the presence of a process having a plurality of temperature controls as in (Patent Document 1) in the sealing process reduces the productivity and thus directly increases the cost. Regarding the manufacturing cost, the manufacturing method of performing local sealing using laser light (Patent Document 2) also has a problem in terms of cost due to the large manufacturing equipment.

In an actual configuration of the light emitting device, for example, an organic electroluminescence element, for example, a driving circuit constituted by a TFT, a lead wiring, and the like are formed and arranged on a substrate constituting the light emitting device. It will be coated.
The above (Patent Document 1) and (Patent Document 2) do not even suggest the importance of this, but the sealing performance such as the so-called gas barrier property greatly depends on the surface state of the structure to be bonded. Therefore, it depends on which structure the outer periphery of the sealing portion comes into contact with and adheres to, and is an important element for surely sealing.

  The present invention is capable of sealing in a simple process using an ultraviolet curable resin as a material for the sealing portion, and is a time for curing the resin without damaging the organic electroluminescence element due to heat. , A light-emitting device that secures a sufficient barrier property against moisture and gas despite using a simple sealing process, a method for manufacturing the light-emitting device, and a highly reliable exposure apparatus incorporating the light-emitting device And an image forming apparatus having a high image quality equipped with the exposure apparatus.

  The light-emitting device of the present invention has been made in view of the above problems, and a first substrate having a first electrode and a light-emitting portion formed on the first substrate using a polymer organic electroluminescent material And a second electrode that covers the light emitting portion, and a sealing portion that is bonded to at least the second electrode and covers a wider area than the second electrode, and is made of an ultraviolet curable resin. The whole of the second substrate is bonded to the opposite side of the sealing portion with the second electrode, and the sealing portion includes an inorganic porous material (crystalline zeolite) having water absorption. It is a thing.

  By using an ultraviolet curable resin as a sealing part member, it becomes possible to cure the resin simply by irradiating ultraviolet rays, and curing to cure the resin compared to a thermosetting resin that is cured by heat retention. By shortening the time, the tact time is shortened, and inexpensive sealing becomes possible. In addition, polymer organic electroluminescent materials have long molecular chains intertwined in a complex manner, and crystallization does not proceed even when exposed to a high temperature environment, resulting in very little deterioration in properties.

  However, when a sealing portion made of a thermosetting resin is provided for a light emitting portion formed using a polymer organic electroluminescence material, the organic electroluminescence element is caused by heat applied when the sealing portion is cured. Slightly damaged. By using an ultraviolet curable resin that does not require heating to cure the resin in the sealing part, the polymer organic electroluminescence element can be sealed without heat damage, enabling more reliable sealing. It becomes.

  Furthermore, this sealing part covers a wider area than the second electrode covering the organic electroluminescence element, and the sealing part is directly bonded to the entire second electrode, so that there is no space in the sealing part, The sealing performance can be improved. In addition, by directly bonding, the sealing portion can fill the unevenness of the wiring portion disposed on the electrode or the first substrate without any gap, and the bonding area between the sealing portion and the first substrate is increased. Therefore, it is possible to improve the adhesive strength, and it is possible to improve not only the sealing performance but also the reliability against external force.

  Also, by bonding the second substrate to the side opposite to the bonding portion with the second electrode, the portion where the sealing portion is exposed to the outside becomes only the thickness of the resin, thereby deteriorating the organic electroluminescence element. It is possible to minimize the moisture intrusion route, and to further improve the barrier property against moisture and gas. In addition, by bonding the second substrate from the upper part of the sealing part, it becomes possible to make the thickness of the sealing part uniform, and the internal stress can be evenly distributed, and the reliability against the internal stress is improved. Is possible.

  Furthermore, the inorganic porous material (crystalline zeolite) having water absorption in the sealing portion contains a minute amount of moisture that has passed through the resin constituting the sealing portion before reaching the light emitting portion. Since it is physically adsorbed by the van der Waals force in the pores of the material, the sealing performance can be greatly improved.

  In addition, since the electrode covering the organic electroluminescence element is composed of a metal material such as aluminum or silver (that is, a material having a high barrier property) as will be described later, it is very coupled with the good barrier property of these sealing portions. High sealing performance can be exhibited.

  The light-emitting device of the present invention includes a first substrate having a first electrode, a light-emitting portion formed on the first substrate using a polymer organic electroluminescent material, and a second substrate covering the light-emitting portion. An electrode and a sealing portion made of an ultraviolet curable resin that covers at least the second electrode and adheres to the second electrode, and the entire second substrate is the sealing portion. The second electrode is bonded to the side opposite to the bonding portion, and the sealing portion is configured to contain an inorganic porous material (crystalline zeolite) having water absorption.

  By using an ultraviolet curable resin as a sealing part member, it becomes possible to cure the resin simply by irradiating ultraviolet rays, and curing to cure the resin compared to a thermosetting resin that is cured by heat retention. By shortening the time, the tact time is shortened, and inexpensive sealing becomes possible. In addition, polymer organic electroluminescent materials have long molecular chains intertwined in a complex manner, and crystallization does not proceed even when exposed to a high temperature environment, resulting in very little deterioration in properties.

  However, when a sealing portion made of a thermosetting resin is provided for a light emitting portion formed using a polymer organic electroluminescence material, the organic electroluminescence element is caused by heat applied when the sealing portion is cured. Slightly damaged. By using an ultraviolet curable resin that does not require heating to cure the resin in the sealing part, the polymer organic electroluminescence element can be sealed without heat damage, enabling more reliable sealing. It becomes.

  Furthermore, this sealing part covers a wider area than the second electrode covering the organic electroluminescence element, and the sealing part is directly bonded to the entire second electrode, so that no space is generated in the sealing part. The sealing performance can be improved.

  In addition, by directly bonding, the sealing portion can fill the unevenness of the wiring portion disposed on the electrode or the first substrate without any gap, and the bonding area between the sealing portion and the first substrate is increased. Therefore, it is possible to improve the adhesive strength, and it is possible to improve not only the sealing performance but also the reliability against external force.

  Also, by bonding the second substrate to the side opposite to the bonding portion with the second electrode, the portion where the sealing portion is exposed to the outside becomes only the thickness of the resin, thereby deteriorating the organic electroluminescence element. It is possible to minimize the moisture intrusion route, and to further improve the barrier property against moisture and gas.

  In addition, by bonding the second substrate from the upper part of the sealing part, it becomes possible to make the thickness of the sealing part uniform, and the internal stress can be evenly distributed, and the reliability against the internal stress is improved. Is possible.

  Furthermore, the inorganic porous material (crystalline zeolite) having water absorption in the sealing portion contains a minute amount of moisture that has passed through the resin constituting the sealing portion before reaching the light emitting portion. Since it is physically adsorbed by the van der Waals force in the pores of the material, the sealing performance can be greatly improved.

  In the present invention, the second substrate facing the second electrode across the sealing portion covers a wider area than the second electrode, and the area of the second substrate is larger than that of the second electrode. It is configured smaller than the part.

  Thereby, when the second substrate is bonded to the sealing portion, the resin is bonded so as to also wrap around the side surface of the second substrate, and as a result, the second substrate is configured to be buried in the resin, Since the number of bonding surfaces between the substrate and the sealing portion is increased and the bonding strength between the sealing portion and the second substrate is improved, it is possible to improve not only the sealing performance but also the reliability against external force. .

  Furthermore, by bonding the second substrate from the upper part of the sealing part, it becomes possible to make the thickness of the sealing part uniform, and the internal stress can be distributed uniformly, and the reliability against the internal stress is improved. Is possible.

  In the present invention, the second substrate is constituted by a substrate having ultraviolet transparency. As a result, when the ultraviolet curable resin of the sealing portion is cured, it becomes possible to irradiate the ultraviolet rays from the upper part of the first substrate, the entire sealing portion can be uniformly cured, and the internal stress is reduced. Generation | occurrence | production can be relieve | moderated and the reliability with respect to an internal stress can be improved.

  In addition, when ultraviolet light is irradiated from the lower part of the first substrate, the polymer organic electroluminescent material of the light emitting part is also irradiated with ultraviolet light, and the polymer organic electroluminescent material is deteriorated.

  On the other hand, when the ultraviolet light is irradiated from the upper part of the second substrate, the light emitting part is covered with the second electrode, which is a metal layer, so the polymer organic electroluminescent material of the light emitting part is irradiated with the ultraviolet light that causes deterioration. Since this is not done, damage from ultraviolet rays can be eliminated.

  In the present invention, the pore size of the fine pores of the inorganic porous material (crystalline zeolite) contained in the sealing portion is 2.8 to 4.2 angstroms. As a result, oxygen molecules and water molecules that cause dark spots and shrinking can be effectively physically adsorbed into the fine pores of the inorganic porous material, which can greatly improve the sealing performance. It becomes possible. In addition, when calcium oxide or diphosphorus pentoxide is used as a water-absorbing material, heat generation and deliquescence occur in the chemical reaction of water absorption. Moreover, a chemical reaction with the ultraviolet curable resin of the sealing portion is caused, and the sealing portion is damaged.

  On the other hand, in the case of water absorption of an inorganic porous material (crystalline zeolite), unlike chemical adsorption, oxygen molecules and water molecules are physically adsorbed in the micropores by van der Waals force, and therefore, chemicals that generate heat. Since no reaction occurs and no reaction with the ultraviolet curable resin occurs, it is possible to absorb water without damaging the sealing portion.

  Furthermore, silica gel or activated carbon that absorbs water by physical adsorption has a large pore size of 50 to 1000 angstroms, so that desorption of adsorbate occurs in a low temperature range compared to inorganic porous materials (crystalline zeolite). In the case of an inorganic porous material (crystalline zeolite), the adsorbate is not desorbed even in a high temperature range, and the sealing performance can be greatly improved.

  Furthermore, the inorganic porous material (crystalline zeolite) does not depend on the humidity of the adsorption performance like silica gel or activated carbon, and can maintain a sufficient adsorption capacity even in a low humidity region. Since the sealing part is filled with resin in the first place and the relative humidity is low, it is possible to maintain the adsorption capacity in a low humidity state and to perform highly reliable sealing independent of humidity.

  Moreover, this invention is comprised so that the effective diameter of the micropore of the inorganic porous material (crystalline zeolite) contained in a sealing part may be 3-5 angstrom. This makes it possible to effectively adsorb oxygen molecules and water molecules, which cause dark spots and shrinking, to the fine pores of the inorganic porous material, thereby greatly improving the sealing performance. It becomes possible. The effective diameter is a diameter slightly larger than the actual size of the micropore due to the expansion and contraction and kinetic energy of the molecule. When a molecule with an effective diameter size slightly larger than the actual size of the micropore is adsorbed, Since it is difficult to desorb compared to molecules smaller than the micropores, it is possible to greatly improve the sealing performance. In addition, when calcium oxide or diphosphorus pentoxide is used as a water-absorbing material, heat generation and deliquescence occur in the chemical reaction of water absorption. Moreover, a chemical reaction with the ultraviolet curable resin of the sealing portion is caused, and the sealing portion is damaged.

  On the other hand, in the case of water absorption of an inorganic porous material (crystalline zeolite), unlike chemical adsorption, oxygen molecules and water molecules are physically adsorbed in the micropores by van der Waals force, and therefore, chemicals that generate heat. Since no reaction occurs and no reaction with the ultraviolet curable resin occurs, it is possible to absorb water without damaging the sealing portion.

  Furthermore, silica gel or activated carbon that absorbs water by physical adsorption has a large pore size of 50 to 1000 angstroms, so that desorption of adsorbate occurs in a low temperature range compared to inorganic porous materials (crystalline zeolite). In the case of an inorganic porous material (crystalline zeolite), the adsorbate is not desorbed even in a high temperature range, and the sealing performance can be greatly improved.

  Furthermore, the inorganic porous material (crystalline zeolite) does not depend on the humidity of the adsorption performance like silica gel or activated carbon, and can maintain a sufficient adsorption capacity even in a low humidity region. Since the sealing part is filled with resin in the first place and the relative humidity is low, it is possible to maintain the adsorption capacity in a low humidity state and to perform highly reliable sealing independent of humidity.

  In the present invention, the inorganic porous material (crystalline zeolite) contained in the sealing portion has a structure represented by (Equation 1),

  The metal cation M is configured to be a potassium ion, a sodium ion, or a calcium ion. This makes it possible to effectively adsorb oxygen molecules and water molecules, which cause dark spots and shrinking, to the fine pores of the inorganic porous material, thereby greatly improving the sealing performance. It becomes possible.

  Furthermore, by combining the adsorption of metal cations in the crystal lattice by electrostatic attraction and the physical adsorption of van der Waals force, it is possible to significantly improve the sealing performance.

  Moreover, when calcium oxide and diphosphorus pentoxide are used as the water-absorbing material, heat generation and deliquescence occur in the chemical reaction of water absorption. Moreover, a chemical reaction with the ultraviolet curable resin of the sealing portion is caused, and the sealing portion is damaged.

  On the other hand, in the case of water absorption of an inorganic porous material (crystalline zeolite), unlike chemical adsorption, oxygen molecules and water molecules are physically adsorbed in the micropores by van der Waals force, and therefore, chemicals that generate heat. Since no reaction occurs and no reaction with the ultraviolet curable resin occurs, it is possible to absorb water without damaging the sealing portion.

  Furthermore, silica gel or activated carbon that absorbs water by physical adsorption has a large pore size of 50 to 1000 angstroms, so that desorption of adsorbate occurs in a low temperature range compared to inorganic porous materials (crystalline zeolite). In the case of an inorganic porous material (crystalline zeolite), the adsorbate is not desorbed even in a high temperature range, and the sealing performance can be greatly improved.

  Furthermore, the inorganic porous material (crystalline zeolite) does not depend on the humidity of the adsorption performance like silica gel or activated carbon, and can maintain a sufficient adsorption capacity even in a low humidity region. Since the sealing portion is entirely filled with resin and the relative humidity is low, it is possible to maintain the adsorption capacity in a low humidity state and to perform highly reliable sealing independent of humidity.

  In the present invention, the pore size of the fine pores of the inorganic porous material (crystalline zeolite) contained in the sealing portion is set to 4.2 angstroms. Thus, only oxygen molecules having a molecular size of 3.46 angstroms and water molecules having a molecular size of 3.8 angstroms, which cause dark spots and shrinking, are selectively and effectively porous. It becomes possible to physically adsorb into the fine pores of the porous material, and the sealing performance can be greatly improved.

  Moreover, when calcium oxide and diphosphorus pentoxide are used as the water-absorbing material, heat generation and deliquescence occur in the chemical reaction of water absorption.

  Moreover, a chemical reaction with the ultraviolet curable resin of the sealing part is caused, and the sealing part is damaged.

  On the other hand, in the case of water absorption of an inorganic porous material (crystalline zeolite), unlike chemical adsorption, oxygen molecules and water molecules are physically adsorbed in the micropores by van der Waals force, and therefore, chemicals that generate heat. Since no reaction occurs and no reaction with the ultraviolet curable resin occurs, it is possible to absorb water without damaging the sealing portion.

  Furthermore, silica gel or activated carbon that absorbs water by physical adsorption has a large pore size of 50 to 1000 angstroms, so that desorption of adsorbate occurs in a low temperature range compared to inorganic porous materials (crystalline zeolite). In the case of an inorganic porous material (crystalline zeolite), the adsorbate is not desorbed even in a high temperature range, and the sealing performance can be greatly improved.

  Furthermore, the inorganic porous material (crystalline zeolite) does not depend on the humidity of the adsorption performance like silica gel or activated carbon, and can maintain a sufficient adsorption capacity even in a low humidity region. Since the sealing part is filled with resin in the first place and the relative humidity is low, it is possible to maintain the adsorption capacity in a low humidity state and to perform highly reliable sealing independent of humidity.

  In the present invention, the effective diameter of the micropores of the inorganic porous material (crystalline zeolite) contained in the sealing portion is 5 angstroms.

  Thus, only oxygen molecules having a molecular size of 3.46 angstroms and water molecules having a molecular size of 3.8 angstroms, which cause dark spots and shrinking, are selectively and effectively porous. It becomes possible to physically adsorb into the fine pores of the porous material, and the sealing performance can be greatly improved.

  The effective diameter is the diameter that is slightly larger than the actual size of the micropore due to the expansion and contraction and kinetic energy of the molecule. When a molecule with a size between the actual size and the effective diameter is adsorbed, it is fine. Since it is difficult to desorb compared to molecules smaller than the pores, the sealing performance can be greatly improved.

  Moreover, when calcium oxide and diphosphorus pentoxide are used as the water-absorbing material, heat generation and deliquescence occur in the chemical reaction of water absorption. Moreover, a chemical reaction with the ultraviolet curable resin of the sealing part is caused, and the sealing part is damaged.

  On the other hand, in the case of water absorption of an inorganic porous material (crystalline zeolite), unlike chemical adsorption, oxygen molecules and water molecules are physically adsorbed in the micropores by van der Waals force, and therefore, chemicals that generate heat. Since no reaction occurs and no reaction with the ultraviolet curable resin occurs, it is possible to absorb water without damaging the sealing portion.

  Furthermore, silica gel or activated carbon that absorbs water by physical adsorption has a large pore size of 50 to 1000 angstroms, so that desorption of adsorbate occurs in a low temperature range compared to inorganic porous materials (crystalline zeolite). In the case of an inorganic porous material (crystalline zeolite), the adsorbate is not desorbed even in a high temperature range, and the sealing performance can be greatly improved. Furthermore, the inorganic porous material (crystalline zeolite) does not depend on the humidity of the adsorption performance like silica gel or activated carbon, and can maintain a sufficient adsorption capacity even in a low humidity region. Since the sealing part is filled with resin in the first place and the relative humidity is low, it is possible to maintain the adsorption capacity in a low humidity state and to perform highly reliable sealing independent of humidity.

  In the present invention, the inorganic porous material (crystalline zeolite) contained in the sealing portion has a structure represented by (Equation 1), and the metal cation M is configured to be calcium ions.

  As a result, only oxygen molecules having a molecular size of 3.46 angstroms and water molecules having a molecular size of 3.8 angstroms that cause dark spots and shrinking are selectively and effectively inorganic. It becomes possible to physically adsorb into the fine pores of the porous material, and the sealing performance can be greatly improved. Furthermore, since the metal cation in the crystal lattice becomes calcium, the outermost shell electrons, so-called valence electrons, become two, so that the valence electrons are more adsorbable by electrostatic attraction than one potassium or sodium. The sealing performance can be greatly improved by strengthening and increasing the adsorptivity by combining the attraction by electrostatic attraction and the physical attraction of van der Waals force.

  In addition, when calcium oxide or diphosphorus pentoxide is used as a water-absorbing material, heat generation and deliquescence occur in the chemical reaction of water absorption. Moreover, a chemical reaction with the ultraviolet curable resin of the sealing portion is caused, and the sealing portion is damaged. On the other hand, in the case of water absorption of an inorganic porous material (crystalline zeolite), unlike chemical adsorption, oxygen molecules and water molecules are physically adsorbed in the micropores by van der Waals force, and therefore, chemicals that generate heat. Since no reaction occurs and no reaction with the ultraviolet curable resin occurs, it is possible to absorb water without damaging the sealing portion. Furthermore, silica gel or activated carbon that absorbs water by physical adsorption has a large pore size of 50 to 1000 angstroms, so that desorption of adsorbate occurs in a low temperature range compared to inorganic porous materials (crystalline zeolite). In the case of an inorganic porous material (crystalline zeolite), the adsorbate is not desorbed even in a high temperature range, and the sealing performance can be greatly improved.

  Furthermore, the inorganic porous material (crystalline zeolite) does not depend on the humidity of the adsorption performance like silica gel or activated carbon, and can maintain a sufficient adsorption capacity even in a low humidity region. Since the sealing part is filled with resin in the first place and the relative humidity is low, it is possible to maintain the adsorption capacity in a low humidity state and to perform highly reliable sealing independent of humidity.

  Moreover, this invention is comprised so that the average diameter of the particle | grains of the inorganic porous material (crystalline zeolite) contained in a sealing part may be 3-10 micrometers. As a result, it is possible to reduce the occurrence of dark spots caused by the destruction of the electrode by particles when the electrode and the sealing portion are bonded together, thereby enabling highly reliable sealing.

  Furthermore, when the particle | grains of an inorganic porous material (crystalline zeolite) are large, when the electrode and the sealing part adhere | attach, an electrode surface will be pushed in by pressing of a particle | grain and an unevenness | corrugation will arise in an electrode part. The convex part of the electrode part has a relatively thin polymer organic electroluminescent material film compared to the concave part, and when a current is applied to the light emitting part, current concentration occurs in the convex part, and the emission intensity of only that part increases. , Lack of uniformity of light emission.

  Moreover, since only that portion emits light brightly, the polymer organic electroluminescent material is locally degraded.

  Furthermore, a short circuit between the electrodes may occur by breaking through the polymer organic electroluminescent material film by pressing. By making the average diameter of the particles uniform and small, it is possible to improve the uniformity of light emission, to prevent local deterioration, and to prevent a short circuit between the electrodes. As a result, a stable light emitting device can be obtained over a long period of time.

  Furthermore, the infiltration path for moisture, gas, etc. that permeate the inside of the resin constituting the sealing portion becomes very long, and the sealing performance can be greatly improved.

  Moreover, this invention is comprised so that the thickness of the ultraviolet curable resin in a sealing part may be 30-250 micrometers. By setting the thickness of the sealing portion to 30 micrometers or more, it is possible to relieve stress due to curing shrinkage that occurs when the ultraviolet curable resin is cured, and as a result, it is possible to improve the adhesive strength of the sealing portion. It becomes.

  Furthermore, it becomes possible to ensure the absolute amount of the inorganic porous material (crystalline zeolite) contained in the sealing portion, and the sealing performance can be improved.

  On the other hand, by setting the thickness of the sealing portion to 250 micrometers or less, it becomes possible to reduce the cross-sectional area of the sealing portion, and to reduce the entrance of moisture, gas, etc. that enter the sealing portion. It is possible to improve the stopping performance.

  Moreover, this invention is comprised so that the thickness of the ultraviolet curable resin in a sealing part may be 50-100 micrometers. By making the thickness of the sealing part 50 μm or more, it is possible to further relax the stress due to curing shrinkage that occurs when the ultraviolet curable resin is cured, and consequently improve the adhesive strength of the sealing part. Is possible.

  Furthermore, it becomes possible to secure a sufficient absolute amount of the inorganic porous material (crystalline zeolite) contained in the sealing portion, and the sealing performance can be greatly improved.

  Furthermore, the unevenness of the structure on the substrate can be sufficiently relaxed, and a short circuit of the organic electroluminescence element can be prevented.

  On the other hand, by making the thickness of the sealing part 100 μm or less, the cross-sectional area of the sealing part is made the minimum necessary for stress relaxation, and the entrance of moisture, gas, etc. that penetrates the sealing part is minimized It becomes possible to make it small, and it becomes possible to improve sealing performance significantly. Further, since the thickness of the sealing portion becomes uniform, internal stress and external force can be alleviated evenly, and peeling of the sealing portion due to local stress can be prevented.

  Moreover, this invention is comprised so that the addition amount of the inorganic porous material (crystalline zeolite) contained in the ultraviolet curable resin which comprises a sealing part may be 10-50 weight% with respect to the weight of an ultraviolet curable resin. It is a thing. By making the addition amount of the inorganic porous material (crystalline zeolite) 10% by weight or more, it becomes possible to secure the absolute amount of the water-absorbing substance and improve the sealing performance.

  On the other hand, by making the amount of inorganic porous material (crystalline zeolite) added 50% by weight or less, it becomes possible to secure the viscosity when the resin is adhered onto the substrate, and the wettability to the substrate is included in the resin. By improving the ease of degassing the generated gas, it is possible to improve the bonding strength by improving the bonding area. Further, the handling property of the resin constituting the sealing portion can be improved, and simple sealing that does not require a large-scale device is possible.

  Moreover, this invention is comprised so that the addition amount of the inorganic porous material (crystalline zeolite) contained in the ultraviolet curable resin which comprises a sealing part may be 30 to 40 weight% with respect to the weight of an ultraviolet curable resin. It is a thing. By making the addition amount of the inorganic porous material (crystalline zeolite) 30% by weight or more, it becomes possible to secure a sufficient absolute amount of the water-absorbing substance, and to greatly improve the sealing performance. .

  On the other hand, when the amount of inorganic porous material (crystalline zeolite) added is 40% by weight or less, it becomes possible to ensure the viscosity when the resin is bonded onto the substrate, wettability to the substrate, and included in the resin. By improving the ease of degassing the generated gas, it is possible to improve the bonding strength by improving the bonding area. Further, the handling property of the resin constituting the sealing portion can be improved, and simple sealing that does not require a large-scale device is possible.

  Furthermore, the inorganic porous material (crystalline zeolite) can be uniformly contained in the ultraviolet curable resin, and the inorganic porous material (crystalline zeolite) can be evenly arranged in the sealing portion. The sealing performance can be greatly improved. Moreover, since the bonding interface of the sealing portion becomes uniform due to the uniform arrangement, the internal stress can be relaxed, and local peeling of the sealing portion can be prevented.

  Moreover, this invention is comprised so that the ultraviolet curable resin which comprises a sealing part may contain both the inorganic porous material (crystalline zeolite) which has water absorption, and the inorganic filler which has cleavage property. . Cleavage means that the crystal is easily cracked in a certain direction, or peels off and a smooth surface (cleavage surface) appears, which allows moisture, gas, etc. to permeate the inside of the resin constituting the sealing part. The penetration path becomes very long, and the sealing performance can be greatly improved.

  Furthermore, since the infiltration path has become very long, there are many opportunities for oxygen molecules and water molecules to be adsorbed by the inorganic porous material (crystalline zeolite), and the sealing performance can be greatly improved.

  Further, in the present invention, the ultraviolet curable resin constituting the sealing portion contains both an inorganic porous material having a water absorption property (crystalline zeolite) and an inorganic filler having a cleavage property, and an inorganic porous material for the resin. It is configured such that the amount of material added is greater than the amount of inorganic filler added. Cleavage means that the crystal is easily cracked in a certain direction, or peels off and a smooth surface (cleavage surface) appears, which allows moisture, gas, etc. to permeate the inside of the resin constituting the sealing part. The penetration path becomes very long, and the sealing performance can be greatly improved.

  Furthermore, since the infiltration path has become very long, there are many opportunities for oxygen molecules and water molecules to be adsorbed by the inorganic porous material (crystalline zeolite), and the sealing performance can be greatly improved.

  Furthermore, since the absolute amount of the inorganic porous material (crystalline zeolite) has increased, the amount of adsorbing oxygen molecules and water molecules can be increased, thereby greatly improving the sealing performance.

    In the present invention, a driving circuit composed of a TFT for driving a light emitting unit is provided on a substrate, and the driving circuit is covered with a sealing unit. If a crack or the like occurs in the drive circuit due to external stress, etc., the light emitting device is fatally damaged such that it cannot be driven, but the drive circuit is protected from external stress by covering the drive circuit part with a sealing part. The reliability of the light emitting device can be improved.

  An exposure apparatus according to the present invention includes the above-described light-emitting device and is configured so that a plurality of light-emitting units can be turned on / off independently. Since the light-emitting device of the present invention exhibits a sufficient sealing performance with a very simple structure, the exposure apparatus equipped with the light-emitting apparatus has high reliability over a long period of time, and further reduces the size and cost of the exposure apparatus. Can be realized.

  In the present invention, the light emitting unit is driven by an active matrix circuit provided on a substrate. Unlike the passive matrix circuit, the electrode (cathode described later) in the active matrix circuit does not need to be formed in a stripe shape, and a large number of spaces are not formed between the electrode and the sealing portion, so that the sealing performance can be improved. It becomes possible.

  Moreover, the manufacturing method of the light-emitting device of the present invention includes a step of forming a light-emitting portion using a polymer organic electroluminescent material on a first substrate having a first electrode, and a second electrode covering the light-emitting portion. And a step of bonding a sealing portion made of an ultraviolet curable resin containing an inorganic porous material (crystalline zeolite) covering at least a wider area than the second electrode onto the first substrate. And a step of adhering the second substrate, a step of curing the adhered ultraviolet curable resin, and a step of at least heat treatment in the step of adhering the resin constituting the sealing portion onto the substrate. It is what I did.

  This makes it possible to reduce the viscosity of the resin when the resin constituting the sealing portion is bonded onto the substrate. By reducing the viscosity, the stress during bonding can be relaxed, and the bonding strength of the sealing portion can be improved. In addition, by reducing the viscosity, it is possible to reduce the pressure on the electrode due to the inorganic porous material contained in the resin, it is possible to improve the uniformity of light emission, prevent local deterioration, and prevent short circuit between the electrodes. In particular, the light emitting device can be stabilized over a long period of time.

  Further, by reducing the viscosity, the wettability to the substrate and the ease of degassing the gas contained in the resin can be improved, so that the adhesion strength can be improved by improving the adhesion area. Further, sealing can be performed by a simple process that does not require a large-scale device.

  The present invention also provides a first heat treatment step after applying a polymer organic electroluminescent material on a substrate, and an ultraviolet curable resin containing an inorganic porous material (crystalline zeolite) constituting a sealing portion. There is a second heat treatment step in the step of bonding onto the substrate, and the temperature of the second heat treatment is lower than the temperature of the first heat treatment.

  As a result, an organic solvent such as toluene or xylene in which the polymer organic electroluminescent material is dissolved can be sufficiently volatilized, and the performance of the organic electroluminescent element as the light emitting portion can be stabilized.

  Furthermore, it is possible to reduce the viscosity of the resin that constitutes the sealing portion and at the same time reduce the damage to the polymer organic electroluminescent material due to the second heat treatment, thereby improving the sealing performance and the performance of the organic electroluminescent element for a long time. It is possible to stabilize.

  An image forming apparatus of the present invention includes the above-described exposure apparatus, a photoreceptor on which a latent image is formed by the exposure apparatus, a developing station that develops and visualizes the latent image formed on the photoreceptor, The image forming apparatus includes a transfer unit that transfers an image developed by the developing station to a recording sheet, and a fixing unit that fixes the image transferred by the transfer unit.

  Since the exposure apparatus of the present invention has features such as high reliability, small size, and low cost, an image forming apparatus equipped with the exposure apparatus can maintain high image quality over a long period of time, and the image forming apparatus Miniaturization and cost reduction can be achieved.

  Hereinafter, the light emitting device according to the present invention will be described in detail. In all the following examples, the light emitting element substrate 70 on which various structures are formed corresponds to the light emitting device according to the present invention.

Example 1
Hereinafter, the structure of the organic electroluminescence element 1 according to the first embodiment will be described in detail with reference to FIG. FIG. 1 is a cross-sectional view showing the structure of an organic electroluminescence element in a light emitting element substrate of Example 1 of the present invention.

i) Substrate Examples of the substrate 2 include inorganic oxide glasses such as transparent or translucent soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz glass. Inorganic glass such as inorganic fluoride glass can be used.

Other materials can be used as the substrate 2, for example, transparent or translucent polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyether sulfone, polyvinyl fluoride, polypropylene, polyethylene, polyacrylate, amorphous polyolefin, Polymer films using polymer materials such as fluororesin polysiloxane and polysilane, or transparent or translucent chalcogenoid glasses such as As ₂ S ₃ , As ₄₀ S ₁₀ , S ₄₀ Ge ₁₀ , ZnO, Nb ₂ When extracting light emitted from a light emitting region without passing through a substrate, such as metal oxides and nitrides such as O, Ta ₂ O ₅ , SiO, Si ₃ N ₄ , HfO ₂ , TiO ₂ , or the like, Opaque silicon, germanium, silicon carbide, gallium arsenide, nitriding It can be used by appropriately selecting from the above-mentioned transparent substrate material containing a semiconductor material such as lithium or the like, a metal material whose surface is insulated, etc., and using a laminated substrate in which a plurality of substrate materials are laminated. You can also.

  In the following description, structures such as the TFT 102 and the organic electroluminescence element 1 formed on the substrate 2 will be described. However, the substrate 2 and all structures formed thereon are integrated. This is referred to as a light emitting element substrate 70 (as described above, this is a “light emitting device”).

ii) TFT
Reference numeral 101 denotes a base coat layer formed on the surface A on the substrate 2, and is configured by stacking, for example, silicon nitride and silicon oxide. A TFT 102 made of polycrystalline silicon (polysilicon) is formed on the base coat layer 101. In the first embodiment, polycrystalline silicon is used as the TFT 102, but amorphous silicon (amorphous silicon) may be used. Amorphous silicon is disadvantageous compared to the low mobility of when constituting a transistor (0.5 cm ² / about Vs) design rules and high mobility in terms of the driving frequency polycrystalline silicon (100~200cm ² / Vs) However, the manufacturing process is inexpensive and has a cost advantage.

  Reference numeral 103 denotes a gate insulating layer made of silicon oxide having a thickness of, for example, about 100 nanometers, and insulates the TFT 102 and the gate electrode 104 made of a metal such as molybdenum at a predetermined interval.

  An intermediate layer 105 is formed by laminating silicon oxide and silicon nitride, for example, and has a total thickness of about 350 nanometers. The intermediate layer 105 covers the gate electrode 104 and supports a source electrode 106 and a drain electrode 107 made of a metal such as Al along the surface.

  The source electrode 106 and the drain electrode 107 are connected to the TFT 102 through contact holes provided in the intermediate layer 105 and the gate insulating layer 103, and a predetermined potential difference is applied between the source electrode 106 and the drain electrode 107. By applying a predetermined potential to the gate electrode 104, the TFT 102 operates as a switching transistor.

  Reference numeral 108 denotes a TFT protective layer made of silicon nitride or the like, which completely covers the source electrode 106 and forms an opening, that is, a contact hole 109 in a part of the drain electrode 107. Usually, the TFT protective layer 108 is formed to a thickness of about 300 nanometers. However, if an overcoat layer (not shown) made of resin or the like is not formed on the upper surface, the TFT protective layer 108 may be formed a little thicker.

The anode 3 uses ITO (indium tin oxide) as the first electrode in the first embodiment. As the anode 3, in addition to ITO, IZO (zinc-doped indium oxide), ATO (Sb-doped SnO ₂ ), AZO (Al-doped ZnO), ZnO, SnO ₂ , In ₂ O _{3 and the} like can be used. . The anode 3 can be formed by a vacuum deposition method or the like, but is preferably formed by a sputtering method or a CVD method (Chemical Vapor Deposition). The anode 3 is connected to the drain electrode 107 through a contact hole 109.

  As shown in FIG. 1, the TFT 102 which is a drive circuit for driving the organic electroluminescence element 1 is completely covered with a sealing portion 10. If a crack or the like is generated in the drive circuit due to external stress or the like, the light emitting device is fatally damaged such that it cannot be driven. However, by covering the drive circuit portion with the sealing portion 10, the TFT 102 which is the drive circuit is externally Thus, the stress of the light source does not act directly, and the reliability of the light emitting device can be improved.

iii) Pixel Restriction Section As defined in the description of the background art, a portion that is sandwiched between at least the anode and the cathode and substantially contributes to light emission in the following description is referred to as a “light emission section”. In the case where illustration is required, it will be described as “light emitting unit LS”.

  Reference numeral 8 denotes a pixel restricting portion that restricts the position, shape, size, and the like of the light emitting portion LS that contributes to light emission by covering part of the anode 3. In the first embodiment, silicon nitride is used as the pixel restricting portion 8, but silicon oxide may be used. The pixel restricting portion 8 is formed by, for example, uniformly forming these metal oxides or metal nitrides by vapor deposition or sputtering, and then patterning, developing, and etching using a photomask. The pixel restricting portion 8 may be formed by a sputtering method through a mask. The thickness of the pixel restricting portion 8 composed of these metal oxides or metal nitrides is preferably 50 nanometers or more and 2 micrometers or less. When the thickness of the pixel restricting portion 8 is less than 50 nanometers, a defect is generated in the film, and the probability that a portion that should not originally emit light emits light increases.

  On the other hand, when the thickness of the pixel restricting portion 8 exceeds 2 micrometers, a step is increased between the anode 3 and the pixel restricting portion 8 at the end of the pixel restricting portion 8 protruding to the anode 3 side. The uniformity of the light emission luminance in the formed light emitting part LS is impaired.

  There are various reasons why the light emitting part LS is configured by restricting the anode 3 with the pixel restricting part 8. For example, when an exposure apparatus is assumed, this is performed to accurately determine the position and shape of the light emitting surface. Of course, since the organic electroluminescence element 1 emits light at the portion where the anode 3 and the cathode 7 facing each other overlap according to the principle described above, the shape and the like of the light emitting portion LS can be regulated by the position and shape of the anode 3 and the cathode 7. However, in the exposure apparatus, for example, the application side demands that the size and arrangement pitch of the light emitting portions LS be extremely small {for example, 600 dpi (dot per inch), that is, the light emitting portion LS is in a direction perpendicular to the paper surface of FIG. In the direction), which is arranged at a pitch of 42.3 micrometers}, so that it is restricted by the electrodes such as the anode 3 and the cathode 7 in the position of the manufacturing process. High accuracy is required for the combination.

  Further, the individual electrode lines become too thin, resulting in a problem that the resistance value increases. Therefore, a method is generally used in which an electrode having a certain width is produced so that the resistance value does not increase, and a part thereof is regulated by the pixel regulating unit 8 to regulate the light emitting surface.

iv) Light-Emitting Layer The light-emitting layer 6 is a light-emitting layer that uses a polymer organic electroluminescent material, which will be described later, in Example 1 and employs a spin coating method that is one of the wet processes capable of reducing the cost by simple steps. 6 is formed by coating.

  In general, a polymer organic electroluminescent material refers to an organic electroluminescent material formed by a wet process such as spin coating, and a low molecular organic electroluminescent material is formed by a dry process such as vacuum deposition. Strictly speaking, a material that cannot be applied with a dry process such as a vacuum deposition method is called a polymer organic electroluminescent material.

  The reason why the vacuum deposition method cannot be applied to the polymer organic electroluminescent material is that the polymer organic electroluminescent material undergoes self-molecular motion before being vaporized, and the main chain is cut. In other words, this leads to lower molecular weight and lowers the original ability of the material.

  In coating and forming the light emitting layer 6 made of a polymer material by spin coating, in Example 1, MEH-PPV (poly [2-methoxy-5- (2′-ethylene) dissolved in toluene as a polymer organic electroluminescence material was used. Hexyloxy) -1,4-phenylenevinylene] (n ≧ 5)) and the film thickness is 120 nanometers.

  MEH-PPV is generally used as a polymer organic electroluminescence material, and can be purchased from, for example, Nippon Sebel Hegner. In addition to this, a styrene-based conjugated dendrimer or the like can be used as the polymer organic electroluminescent material.

  When the light emitting layer 6 is applied by the above-described spin coating method, the polymer organic electroluminescent material is applied on all the structures formed on the light emitting element substrate 70 before the light emitting layer 6 is formed. .

  In such a case, before forming the cathode 7 to be described later by the vapor deposition method, a predetermined area is wiped off by a manufacturing facility in which a solvent such as toluene or xylene is re-applied and recovered together with the molten polymer organic electroluminescent material. It is done.

  This wiping step can also be performed by, for example, a laser ablation method. Moreover, when the construction method which can apply | coat a polymeric organic electroluminescent material only to a predetermined area | region like the flood printing method using an inkjet technique is used, the above-mentioned wiping process becomes unnecessary.

  In any case, when a sealing portion 10 to be described later is formed in a state where a polymer organic electroluminescent material is applied to the entire surface of the light emitting element substrate 70, the organic electroluminescent element 1 ( It has been confirmed that since water penetrates into the interior of the light-emitting portion LS (see FIG. 1), shrinking of the light-emitting portion LS (see FIG. 1) and expansion of the dark spot easily proceed. The polymer organic electroluminescent material needs to be removed at least in the outer peripheral portion of the sealing portion 10.

  After this wiping process, the light emitting element substrate 70 is left in an environment of about 130 ° C. for about 1 hour to sufficiently volatilize an organic solvent such as toluene or xylene, which is a solvent in which the polymer organic electroluminescent material is dissolved (baking process). ). Hereinafter, the temperature in the baking process is referred to as the baking temperature.

  Now, the light emitting element substrate 70 according to the present invention includes a substrate 2 having an anode 3, a light emitting portion LS formed on the substrate 2 using a polymer organic electroluminescence material, and a second covering the light emitting portion LS. An electrode (cathode 7 described later), and a sealing portion (sealing portion 10 described later) made of an ultraviolet curable resin that adheres to at least the cathode 7 and covers a wider area than the cathode 7. The whole of the second substrate (sealing substrate 9 to be described later) is bonded to the opposite side of the sealing portion 10 from the bonding portion with the cathode 7, and the sealing portion 10 has an inorganic porous material (crystallinity). Zeolite) is contained, and the use of a polymer organic electroluminescent material as a material of the light emitting layer 6 constituting the light emitting portion LS is a major point. Below, the characteristic of a polymer organic electroluminescent material is demonstrated in detail through the comparison with the conventional low molecular organic electroluminescent material.

  Among the light-emitting materials that make up organic electroluminescent elements, low-molecular organic electroluminescent materials that have been widely used in the past are generally vulnerable to high-temperature environments because their organic compound groups are formed by vacuum deposition and become amorphous thin films. The heat-resistant temperature is at most a few tens of degrees Celsius. This is because, when exposed to a high temperature environment, the crystallization of the low molecular weight organic compound proceeds and the characteristics as a light emitting material deteriorate.

  In contrast, polymer organic electroluminescent materials form thin films by intertwining long molecular chains in a complicated manner, and there is no clear crystallization temperature, and there is an index to be called the softening start temperature called the glass transition point. It only exists.

  Furthermore, even a clear glass transition point may not be observed in many polymeric organic electroluminescent materials. In other words, the polymer organic electroluminescent material cannot move freely and crystallize due to the structure in which the molecules are intertwined.

  Such a characteristic of the polymer organic electroluminescent material appears as a great advantage of high heat resistance when the polymer organic electroluminescent material is applied to an organic electroluminescent element. This heat-resistant temperature sufficiently exceeds 200 ° C. including the already explained HEM-PPV. The light emitting part LS composed of the polymer organic electroluminescent material having the great feature of high heat resistance is also deteriorated in light emitting characteristics by a heat treatment process in sealing using an ultraviolet curable resin, which will be described later. Therefore, it is possible to effectively utilize the high barrier property against moisture and gas in the sealing portion.

  However, even low-molecular organic electroluminescent materials formed using a dry process such as vacuum evaporation are oligomers with high molecular weight and relatively high glass point transfer, more specifically PPV oligomers. In addition, it has high heat resistance and can easily apply wet processes, and these can be applied to the light emitting element substrate 70 of the present invention as an alternative to the polymer organic electroluminescence material.

  In Example 1, the light emitting layer 6 is a single layer film made of MEH-PPV. However, it may be a laminated film made of several materials. For example, in order to confine the charge injected into the MEH-PPV layer and improve the recombination efficiency, it is desirable to add a layer made of a material having an electron blocking function or a hole blocking function, which leads to improvement in device characteristics. .

  Specifically, the light-emitting layer 6 may have a three-layer structure of hole transport layer / electron block layer / the above-described organic light-emitting material (both not shown) in order from the anode 3 side. Two-layer structure of electron transport layer / organic light-emitting material (both not shown) in order from the side, or two-layer structure of hole transport layer / organic light-emitting material (both not shown), or the anode from the side of anode 3 It is good also as a 7-layer structure (all not shown) like hole injection layer / hole transport layer / electron block layer / organic light emitting layer / hole block layer / electron transport layer / electron injection layer in order from the 3 side. As described above, the light emitting layer 6 in Example 1 includes a case where the light emitting layer 6 has a multilayer structure having functional layers such as a hole transport layer, an electron block layer, and an electron transport layer.

  The hole transport layer contained in the light emitting layer 6 is preferably one having high hole mobility and being transparent and having good film forming properties. In addition to TPD described in the background art, porphin, tetraphenylporphine copper, phthalocyanine, copper Polyphyrin compounds such as phthalocyanine and titanium phthalocyanine oxide, 1,1-bis {4- (di-P-tolylamino) phenyl} cyclohexane, 4,4 ′, 4 ″ -trimethyltriphenylamine, N, N, N ′ , N'-tetrakis (P-tolyl) -P-phenylenediamine, 1- (N, N-di-P-tolylamino) naphthalene, 4,4'-bis (dimethylamino) -2-2'-dimethyltriphenyl Methane, N, N, N ', N'-tetraphenyl-4,4'-diaminobiphenyl, N, N'-diphenyl-N, N'- Aromatic tertiary amines such as m-tolyl-4,4'-diaminobiphenyl, N-phenylcarbazole, 4-di-P-tolylaminostilbene, 4- (di-P-tolylamino)- Stilbene compounds such as 4 '-[4- (di-P-tolylamino) styryl] stilbene, triazole derivatives, oxazizazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, annealed amine derivatives, amino Substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, polysilane aniline copolymers, polymer oligomers, styrylamine compounds, aromatic dimethylidin compounds, poly-3,4 ether Nji thiophene (PEDOT), organic materials such as polythiophene derivatives, such as tetra-Hye click sill fluorenyl biphenyl (TFB), or poly-3-methylthiophene (pMET) is used.

Further, a polymer-dispersed hole transport layer in which an organic material for a low-molecular hole transport layer is dispersed in a polymer such as polycarbonate is also used. In addition, inorganic oxides such as MoO ₃ , V ₂ O ₅ , WO ₃ , TiO ₂ , SiO, and MgO may be used. Moreover, these hole transport materials can also be used as an electron block material.

  As the electron transport layer in the light emitting layer 6 described above, oxadiazole derivatives such as 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7), anthraquinodimethane Derivatives, diphenylquinone derivatives, polymer materials composed of silole derivatives, etc., or bis (2-methyl-8-quinolinolate)-(para-phenylphenolate) Al (BAlq), bathofproin (BCP), etc. are used. Moreover, the material which can comprise these electron carrying layers can also be used as a hole block material.

  As mentioned above, although the light emitting layer 6 in Example 1 was demonstrated in detail, as a high molecular organic electroluminescent material which comprises the light emitting layer 6, it is not limited to MEH-PPV mentioned above, It is fluorescent or phosphorescent in visible region. A material having characteristics and good film forming properties can be selected. For example, a polymer light-emitting material such as polyparaphenylene vinylene (PPV) or polyfluorene can be used.

  Furthermore, polymer organic electroluminescent materials having various characteristics and emission colors have been proposed at present, and the light emitting layer 6 can be configured by appropriately selecting from these.

v) Cathode The cathode 7 is formed of a metal material such as Al by, for example, a vacuum deposition method. As the cathode 7 of the organic electroluminescent element 1, a metal or alloy having a low work function, for example, a metal such as Al, In, Mg, Ti, or Ag, a Mg alloy such as a Mg—Ag alloy or a Mg—In alloy, Al— Al alloys such as a Li alloy, an Al—Sr alloy, and an Al—Ba alloy are used. Alternatively, an electron injection electrode layer in contact with a metal such as Ba, Ca, Mg, Li, or Cs, or an organic layer made of a fluoride or oxide of these metals such as LiF or CaO, and Al, Ag, or the like formed thereon. A metal laminated structure including a protective electrode made of a metal material such as In can also be used.

  The cathode 7 needs to cover at least the entire surface of the light emitting unit LS because of the need to supply charges to the light emitting unit LS. However, by covering the entire surface of the light emitting unit LS with the cathode 7 made of metal, the cathode 7 can be externally applied. It is also possible to have a sealing function for preventing the intrusion of moisture.

  In Example 1, the organic electroluminescence element is covered with a cathode 7 made of a metal having a high barrier property against gas and moisture, and further, the sealing portion 10 is configured to cover the whole of the cathode 7 as described later. A light emitting device is configured.

  The organic electroluminescence element 1 is formed on the substrate 2 by the structure and process described above. The TFT 102 is formed in a 1: 1 relationship with respect to each organic electroluminescence element 1 and electrically constitutes a so-called active matrix circuit.

  The source electrode 106 is used as a positive electrode, a predetermined potential difference is provided between the source electrode 106 and the cathode 7, and the gate electrode 104 is controlled to a predetermined potential, so that holes are generated in the source electrode 106, the TFT 102, the drain electrode 107, and the anode 3. Then, electrons are injected into the light emitting layer 6, while electrons are injected from the cathode 7 into the light emitting layer 6. In the light emitting layer 6, recombination of holes and electrons occurs, and a light emission phenomenon occurs when excitons generated thereby shift from the excited state to the ground state.

  Thus, the light-emitting device of Example 1 has an active matrix configuration, and the above-described cathode 7 is formed over the entire surface of the plurality of organic electroluminescence elements 1. When the passive matrix configuration is used, the cathodes need to be formed in stripes, resulting in steps caused by a large number of cathodes. However, when the active matrix configuration is used, the steps between the cathodes adversely affect the sealing performance. Never give. This is also one of the factors that improve the sealing performance.

  The light emitted from the light emitting layer 6 passes through the anode 3, the intermediate layer 105, the gate insulating layer 103, the base coat layer 101, and the substrate 2, and is emitted from the surface opposite to the surface A of the substrate 2 and passes through a photoreceptor (not shown). Exposure.

vi) Sealing portion The sealing portion 10 is composed of an ultraviolet curable resin containing an inorganic porous material (crystalline zeolite) 201 and an inorganic filler 202, and the sealing substrate 9 is composed of a substrate having ultraviolet transparency. ing. The sealing part 10 is adhered to at least the cathode 7 as shown in the figure, and completely covers the light emitting part LS whose size and shape are regulated by the pixel regulating part 8.

  The entire sealing substrate 9 is bonded to the opposite side of the sealing portion 10 to the bonding portion with the cathode 7. As described later in detail with reference to FIG. 2, the sealing portion 10 further completely covers the cathode 7, and the sealing substrate 9 is configured to be larger than the cathode 7 and smaller than the sealing portion 10.

  Now, as the ultraviolet curable resin, epoxy resin and acrylic resin are generally used. However, in Example 1, an epoxy resin is adopted in consideration of a small curing shrinkage and a small degassing. Yes. In forming the sealing portion 10 on the light emitting element substrate 70, an ultraviolet curable resin is applied to the upper surface of the cathode 7 formed on the light emitting element substrate 70 using a dispenser. It is possible to adjust the supply amount. Further, the method of applying the ultraviolet curable resin is not limited to the above-mentioned dispenser.

  In Example 1, an epoxy resin was used as the ultraviolet curable resin, but polycarbonate, polymethyl methacrylate, polyacrylate, methyl phthalate homopolymer or copolymer, polyethylene terephthalate, polystyrene, diethylene glycol bisallyl carbonate, acrylonitrile / Styrene copolymer, poly (-4-methylpentene-1), phenol resin, cyanate resin, maleimide resin, polyimide resin, acrylic resin and the like can be mentioned. Further, those modified with polyvinyl butyral, acrylonitrile-butadiene rubber, polyfunctional acrylate compound, etc., crosslinked polyethylene resin, crosslinked polyethylene / epoxy resin, polyphenylene ether / cyanate resin and the like can also be used. A plurality of types of resins as listed above may be used in combination.

  Regarding the epoxy resin used as the sealing portion 10, there are two types, an ultraviolet curable resin and a thermosetting resin. In the former, a UV-reactive photocrosslinking initiator is added, and the curing reaction is instantly started by UV irradiation, and the curing reaction is completed in a relatively short time, so the tact time of the sealing process is short. Therefore, inexpensive sealing is possible. In addition, since heating is not required for curing the resin, the polymer organic electroluminescence element can be sealed without being damaged by heat, and more reliable sealing is possible.

  On the other hand, in the latter thermosetting resin, the curing reaction is started by heating, and the heat necessary for the curing becomes hundreds of degrees and damages the polymer organic electroluminescence element due to heat. In addition, since the resin is cured by heat retention, even if the curing reaction is completed, a sudden temperature change may cause thermal stress of the substrate and resin, which may cause the sealing part to peel off. The process must be performed. Therefore, since the sealing process takes time, the tact time for sealing becomes long.

  Further, the sealing portion 10 covers a wider area than the cathode 7 covering the organic electroluminescence element, and the sealing portion 10 is directly bonded to the entire cathode 7, so that no space is generated in the sealing portion 10. The sealing performance can be improved.

  Moreover, since the sealing part 10 can fill the unevenness | corrugation of the wiring part arrange | positioned on the cathode 7 or the board | substrate 2 without gap by direct bonding, the adhesion area of the sealing part 10 and the board | substrate 2 becomes large. Adhesive strength can be improved, and not only the sealing performance but also the reliability against external force can be improved.

The sealing substrate 9 may be any substrate as long as it has ultraviolet transparency, and i
) It can be used with a colorless and transparent substrate as already described for the substrate. By adhering the sealing substrate 9 to the opposite side of the sealing part 10 to the bonding part with the cathode 7, the contact part with the outside in the sealing part 10 becomes only the thickness of the resin, whereby the organic electroluminescence element It is possible to minimize the moisture intrusion route that degrades the moisture, and to further improve the barrier property against moisture and gas. Further, by adhering the sealing substrate 9 from the upper part of the sealing part 10, the thickness of the sealing part 10 can be made uniform, the internal stress can be uniformly distributed, and the reliability against the internal stress is improved. Can be improved.

  Further, by using the sealing substrate 9 having ultraviolet transparency, when the ultraviolet curable resin of the sealing portion 10 is cured, ultraviolet rays are irradiated from the upper part of the substrate 2 (upper part of the sealing substrate 9). Thus, the entire sealing portion can be uniformly cured, the generation of internal stress can be reduced, and the reliability against internal stress can be improved.

  On the other hand, when the ultraviolet rays are irradiated from the lower part of the substrate 2, ii) as already described in the TFT, a shadow of the gate electrode and the source electrode made of a metal that does not transmit light is formed. The ultraviolet rays are not irradiated, and the curing of the resin is not started. For this reason, the resin cannot be uniformly cured, causing internal stress. Furthermore, the polymer organic electroluminescent material of the light emitting part is also irradiated with ultraviolet rays, and the polymer organic electroluminescent material is deteriorated.

  On the other hand, when the ultraviolet light is irradiated from the upper part of the sealing substrate 9, since the light emitting part is covered with the cathode 7 which is a metal layer, the polymer organic electroluminescent material of the light emitting part is not irradiated with the ultraviolet light causing deterioration. No damage from UV rays.

  By including an inorganic porous material (crystalline zeolite) having water absorption in the sealing portion 10, the sealing performance can be greatly improved. This inorganic porous material is preliminarily heated in a heating furnace at 300 ° C. or higher for several hours to completely desorb the adsorbate and then contained in the ultraviolet curable resin. Also, cooling after heating must be done without touching the atmosphere, especially moisture. Also, the ultraviolet curable resin must be in an environment where it is not exposed to the atmosphere, particularly moisture. Even when the inorganic porous material having the adsorbed material removed from the ultraviolet curable resin is contained, it must be carried out without being exposed to air or moisture. For example, it is desirable to carry out in a box substituted with nitrogen or argon. Further, it is desirable to perform all the steps for forming the sealing portion in a box substituted with nitrogen or argon. It is desirable to carry out in a so-called inert environment.

  By adding an inorganic porous material, a minute amount of moisture that has passed through the inside of the resin is physically adsorbed to the micropores formed on the surface of the inorganic porous material by van der Waals force, before reaching the light emitting part. Be captured. Furthermore, since the degassed component from the resin is also adsorbed, it is possible to suppress damage to the polymer organic electroluminescence.

  This inorganic porous material is preferably a crystalline zeolite, for example, a molecular sieve composed of synthetic zeolite, etc., having a structure represented by (Equation 1), wherein M as a metal cation is potassium ion, sodium ion, What was comprised so that it might become calcium ion is good. Among them, calcium ion improves sealing performance. This is because the adsorption ability of the metal cations in the crystal lattice due to the electrostatic attraction and the physical adsorption of the van der Waals force can be enhanced to further improve the water-absorbing ability, greatly improving the sealing performance. It becomes possible to improve.

    Further, it is preferable that the pore size of the fine pores of the inorganic porous material (crystalline zeolite) is 2.8 to 4.2 angstroms, and the pore size is 4.2 angstroms. What was comprised so that it may improve sealing performance more.

    Moreover, what was comprised so that the effective diameter of a micropore may be 3-5 angstrom is good, and what was comprised so that the effective diameter of a micropore may become 5 angstrom improves the sealing performance more. This is an inorganic porous material that selectively and effectively causes only oxygen molecules having a molecular size of 3.46 angstroms and water molecules having a molecular size of 3.8 angstroms, which cause dark spots and shrinking. By being able to physically adsorb into the fine pores of the porous material, the sealing performance can be greatly improved.

  In addition, when calcium oxide or diphosphorus pentoxide, which is known by chemical adsorption, is used as a water-absorbing material, a water-absorbing action is caused by a chemical reaction with a small amount of moisture that has passed through the inside of the seal. These substances generate heat due to a chemical reaction with moisture, cause deliquescence, and damage the polymer organic electroluminescence element. Moreover, a chemical reaction with the ultraviolet curable resin of the sealing part is caused, and the sealing part is damaged.

  On the other hand, in the case of water absorption of an inorganic porous material (crystalline zeolite), unlike chemical adsorption, oxygen molecules and water molecules are physically adsorbed in the micropores by van der Waals force, and therefore, chemicals that generate heat. Since the reaction does not occur and the reaction with the ultraviolet curable resin does not occur, the sealing portion is not damaged, so that the sealing portion can be sealed without deterioration.

  Some molecular sieves that absorb water by physical adsorption have large pore diameters. For example, those with 10 angstroms are oxygen spots with a pore size of 3.46 angstroms that cause dark spots and shrinking. Since molecules and molecules are larger than water molecules of 3.8 angstroms, they absorb even dark spots and substances that do not cause shrinking. The water-absorbing effect until it was improved significantly was not confirmed.

  Silica gel, activated carbon, and the like that absorb water by physical adsorption have a large pore size of 50 to 1000 angstroms, and therefore, adsorbates are desorbed at a lower temperature than inorganic porous materials (crystalline zeolite). Ultimately, the sealing performance is not improved.

  On the other hand, in the case of an inorganic porous material (crystalline zeolite), the adsorbate is not desorbed even in a high temperature range, and the sealing performance can be greatly improved.

  Furthermore, the inorganic porous material (crystalline zeolite) does not depend on the humidity of the adsorption performance like silica gel or activated carbon, and can maintain a sufficient adsorption capacity even in a low humidity region. Since the sealing part is filled with resin in the first place and the relative humidity is low, more reliable sealing is possible with an inorganic porous material (crystalline zeolite) that can maintain adsorption capacity in a low humidity state. Become.

  Moreover, it is good to comprise so that the average diameter of the particle | grains of an inorganic porous material (crystalline zeolite) may be 3-10 micrometers. As a result, when the cathode 7 and the sealing portion 10 are adhered, the generation of dark spots caused by the particles breaking the cathode 7 can be reduced.

  When the particles of the inorganic porous material (crystalline zeolite) are large, the surface of the cathode 7 is pushed by the pressing of the particles when the cathode 7 and the sealing portion 10 are bonded, and the cathode 7 is uneven. The convex portion of the cathode 7 has a relatively thin polymer organic electroluminescent material film as compared with the concave portion. When a current is applied to the light emitting portion, current concentration occurs in the convex portion, and only the portion has a light emission intensity. It becomes strong and lacks the uniformity of light emission. A so-called luminescent bright spot is formed.

  Moreover, since only that portion emits light brightly, the polymer organic electroluminescent material is locally degraded. Furthermore, the convex part of the cathode 7 may break through the film of the polymer organic electroluminescence material due to the pressing of the particles, thereby causing a short circuit between the electrodes.

    By making the average diameter of the particles uniform and small, it leads to prevention of the above-mentioned luminescent bright spots, improvement of light emission uniformity, prevention of local deterioration, prevention of short circuit between electrodes, and as a result stable for a long time. A light emitting device is possible.

  The amount of these inorganic porous materials (crystalline zeolite) added is also an important factor. In the ultraviolet curable resin used in the present invention, the moisture permeability of the sealing portion 10 is remarkably lowered by setting the content of the inorganic porous material (crystalline zeolite) to 10 weight percent or more and 50 weight percent or less. It is possible. Furthermore, 30 weight percent or more and 40 weight percent or less are desirable.

By making the addition amount of the inorganic porous material (crystalline zeolite) 10% by weight or more, it becomes possible to secure the absolute amount of the water-absorbing substance and improve the sealing performance.
On the other hand, if the added amount of the inorganic porous material (crystalline zeolite) is 10 weight percent or less, the absolute amount of the water-absorbing substance is small, and all of the water passing through the sealing portion cannot be adsorbed, and dark It will accelerate the growth of spots and shrinking.

  In addition, by setting the amount of inorganic porous material (crystalline zeolite) to 50% by weight or less, it becomes possible to secure viscosity when the resin is bonded onto the substrate, wettability to the substrate, and included in the resin. By improving the ease of degassing the generated gas, it is possible to improve the bonding strength by improving the bonding area.

  Further, the handling property of the resin constituting the sealing portion can be improved, and simple sealing that does not require a large-scale device is possible.

  On the other hand, when the addition amount of the inorganic porous material (crystalline zeolite) is 50 weight percent or more, the viscosity of the resin is extremely increased, and the application onto the cathode 7 becomes difficult. For this reason, it is preferable that the content of the inorganic porous material (crystalline zeolite) be 10 weight percent or more and 50 weight percent or less. Furthermore, 30 weight percent or more and 40 weight percent or less are desirable.

  Furthermore, in order to improve the moisture permeability of the resin, both an inorganic porous material (crystalline zeolite) and an inorganic filler (filler) may be added to the resin itself. By adding an inorganic filler having a cleavage property, it is possible to lengthen the infiltration path for moisture, gas, and the like that permeate the inside of the resin. Furthermore, since the infiltration path has become very long, there are many opportunities for oxygen molecules and water molecules to be adsorbed by the inorganic porous material (crystalline zeolite), and the sealing performance can be greatly improved.

  Further, in order to suppress damage to the polymer organic electroluminescence element as much as possible by degassing from the resin, it is desirable that the amount of the solvent and the reaction initiator is small.

  The inorganic filler is preferably, for example, a plate-like inorganic filler or a scale-like inorganic filler. The plate-like inorganic filler and the scale-like inorganic filler are inorganic fillers having cleavage properties in most cases. Cleavage means that a crystal is easily cracked or peeled off in a certain direction and a smooth surface (cleavage surface) appears. That is, as a result, if it has cleavage property, each particle | grain of a filler will become plate shape or scale shape. Examples of such inorganic fillers include talc, mica, mica, and the like, but glass flakes are not particularly limited as long as the shape requirements are satisfied.

  The amount of these inorganic fillers added is also an important factor. In the ultraviolet curable resin used in the present invention, the addition amount of the inorganic porous material is larger than the addition amount of the inorganic filler composed of the plate-like inorganic filler or the scaly inorganic filler, so that oxygen molecules and water molecules are reduced. Opportunities to be adsorbed by the inorganic porous material (crystalline zeolite) are further increased, and the moisture permeability of the sealing portion 10 can be significantly reduced.

  Regarding the thickness required for the sealing portion 10, by making the thickness of the sealing portion 10 30 micrometers or more, it becomes possible to relieve stress due to curing shrinkage that occurs when the ultraviolet curable resin is cured. It becomes possible to improve the adhesive strength of the sealing portion.

  Furthermore, it becomes possible to ensure the absolute amount of the inorganic porous material (crystalline zeolite) contained in the sealing part 10 and to improve the sealing performance. On the other hand, when the thickness of the sealing portion 10 is 30 micrometers or less, the stress due to curing shrinkage cannot be absorbed, which causes peeling of the sealing portion.

  By setting the thickness of the sealing portion 10 to 250 micrometers or less, the cross-sectional area of the sealing portion 10 can be reduced, and the entrance of moisture, gas, or the like that enters the sealing portion 10 can be reduced. It becomes possible to improve sealing performance.

  On the other hand, when the thickness of the sealing portion 10 is 250 micrometers or more, the water and gas inlets become large, and the water absorption capacity of the inorganic porous material (crystalline zeolite) contained becomes insufficient, so The polymer organic electroluminescence element is reached. Further, in order to improve the sealing performance by significantly reducing the moisture permeability, it is desirable to set the thickness of the sealing portion 10 to 50 micrometers or more and 100 micrometers or less.

    As described above, the ultraviolet curable resin constituting the sealing portion 10 contains an inorganic porous material (crystalline zeolite) and an inorganic filling material in an inert environment, and then a light emitting element substrate using a dispenser. Although an ultraviolet curable resin is applied to the upper surface of the cathode 7 formed on 70, the supply amount can be adjusted by the application speed and pressure of the dispenser.

    In this invention, after apply | coating an ultraviolet curable resin to the cathode 7, it has the process of applying predetermined heat processing, when adhering the sealing substrate 9 to an ultraviolet curable resin from the upper part. By applying a predetermined heat treatment, the viscosity of the UV curable resin having increased viscosity can be lowered sufficiently by containing the inorganic porous material (crystalline zeolite) and the inorganic filler material, thereby lowering the viscosity. As a result, the stress during bonding can be relaxed, and the bonding strength of the sealing portion can be improved.

    In addition, it is possible to sufficiently bond even unevenness such as wiring formed on the substrate 2. Therefore, the bonding area of the sealing portion 10 on the substrate 2 is increased, and the bonding strength can be improved.

    Also, by reducing the viscosity, it becomes possible to reduce the pressure on the cathode 7 by the inorganic porous material or inorganic filling material contained in the resin, thereby preventing emission bright spots, improving the uniformity of emission, and local deterioration. And a short circuit between the electrodes, and as a result, a light-emitting device that is stable over a long period of time becomes possible.

  Furthermore, by lowering the viscosity, the gas contained in the resin can be easily degassed, but the uniformity of the resin thickness is maintained. As a result, the internal stress can be relaxed. Further, since the gas contained in the resin is eliminated, the adhesion area is increased and the adhesion strength can be improved. In addition, since the viscosity is sufficiently lowered, handling is improved, and sealing can be performed by a simple process that does not require a large-scale device. Further, as an improvement in handling properties, a coating device such as a dispenser may be heated in advance before the ultraviolet curable resin is applied to the cathode 7.

  In the present invention, the heating temperature as the predetermined heat treatment is controlled to iv) the baking temperature for the light emitting layer 6 made of the polymer organic electroluminescent material as described in the light emitting layer is lower than 130 ° C. is there. Specifically, it is desirable to set to 60 ° C to 80 ° C.

  As a result, it is possible to reduce the viscosity of the resin constituting the sealing portion 10 and at the same time reduce the damage to the polymer organic electroluminescent material due to the heat treatment in the sealing step, and the sealing performance and the organic electroluminescent element It becomes possible to stabilize the performance for a long time.

  iv) As described in the light-emitting layer, the high-molecular organic electroluminescent material has a much higher heat resistance temperature than the low-molecular organic electroluminescent material. Usually, when the light emitting layer 6 of the organic electroluminescence element 1 is made of a low molecular material, when the sealing portion 10 is heat-treated in a heating environment of 80 ° C., the low molecular material constituting the light emitting layer 6 is crystallized to emit light. Function is lost.

  Furthermore, once crystallized, the molecular state will not be restored even if the temperature is lowered. On the other hand, when the polymer material already described is used, the molecular state does not change even in such a heating environment, and the light emitting function is maintained. Therefore, when the light emitting layer 6 is made of a polymer organic electroluminescence material, heat treatment can be performed in the step of forming the sealing portion 10.

  In addition, when a thermosetting resin is used instead of an ultraviolet curable resin, curing of the resin is started by a heat treatment that should be aimed at lowering the viscosity of the resin, thereby sufficiently reducing the viscosity of the resin. As a result, a stable sealing process becomes difficult. Further, when a thermosetting resin that does not cure at 60 ° C. to 80 ° C. is used, a decrease in viscosity is obtained, but the curing temperature is increased, resulting in damage to the polymer organic electroluminescent material due to heating.

vii) Sealing Portion Outer Peripheral Portion FIG. 2 is a cross-sectional view showing the configuration of the outer peripheral portion of the sealing portion in the light emitting element substrate of Example 1 of the invention.

  Hereinafter, the configuration of the outer peripheral portion of the sealing portion 10 will be described in detail with reference to FIG.

  In FIG. 2, an arrow P indicates a structure constituting the light emitting element substrate 70 (that is, the substrate 2, the base coat layer 101, the gate insulating layer 103, the intermediate layer 105, the TFT protective layer 108, the pixel regulating portion 8, the light emitting layer 6, the cathode 7). , The sealing substrate 9 and the sealing portion 10) are continuously formed from the arrow P in FIG. 1, and the same applies to the arrow Q.

  However, FIG. 1 and FIG. 2 are not immediately connected at the positions of the arrow P and the arrow Q, but are connected through a small space (not shown). Further, in the case of the arrow Q, it is shown that the structure in which FIG.

  As shown in FIG. 2, the present invention is such that the sealing substrate 9 facing the cathode 7 across the sealing portion 10 covers a wider area than the cathode 7, and the area of the sealing substrate 9 is larger than the cathode 7, The sealing portion 10 is configured to be smaller than the sealing portion 10, and the outer peripheral portion of the sealing portion 10 is configured to adhere to the TFT protective layer 108.

  As a result, when the sealing substrate 9 is bonded to the sealing portion 10, the ultraviolet curable resin is bonded so as to wrap around the side surface of the sealing substrate 9. As a result, the sealing substrate 9 is buried in the resin. Since the number of adhesion surfaces between the sealing substrate 9 and the sealing portion 10 is increased and the adhesion strength between the sealing portion 10 and the sealing substrate 9 is improved, not only the sealing performance but also the external force It becomes possible to improve the reliability with respect to.

  Further, by adhering the sealing substrate 9 from the upper part of the sealing part, it is possible to make the thickness of the sealing part 10 uniform, and it is possible to uniformly disperse the internal stress, and to improve the reliability against the internal stress. Improvement is possible.

  iv) After the baking process described in the light emitting layer, the cathode 7 is formed so as to cover at least the entire surface of the light emitting portion LS (see FIG. 1) by vacuum deposition. The range in which the cathode 7 is formed can be adjusted with a relatively high degree of freedom by a mask in vacuum deposition.

  After the cathode 7 is formed, vi) the sealing portion 10 is formed by the process described in the sealing portion. At this time, the outer peripheral portion PO of the sealing portion 10 is bonded to the TFT protective layer 108. Since the TFT protective layer 108 is made of an extremely dense material such as silicon oxide and can be formed sufficiently thick, the surface of the TFT protective layer 108 is not affected by unevenness due to the underlying structure and is extremely smooth. The degree becomes higher. As a result, the sealing portion 10 formed on the TFT protective layer 108 is stably bonded to the TFT protective layer 108.

  Now, even if the TFT protective layer 108 and the sealing portion 10 are firmly bonded in this manner and the internal organic electroluminescent element 1 is sealed, an extremely small amount of moisture may enter the organic electroluminescent element 1. is there. In order to suppress this as much as possible and ensure long-term reliability of the light-emitting element substrate 70, the end portion of the light-emitting layer 6 and the sealing portion 10 that have been wiped off (see iv) for the wiping process) It is necessary to secure the distance Lf (sealing margin) as long as possible. The sealing margin Lf is required to be at least 0.5 mm or more, and if it is 2 mm, sufficient sealing performance can be ensured.

  In general, in the structure related to the TFT 102 (see FIG. 1) constituting the light emitting element substrate 70, an interface for inputting a control signal to drive the TFT 102 is configured in the peripheral portion of the TFT protective layer 108. Specifically, a contact hole (not shown) for making contact with an external circuit is formed in the peripheral portion of the TFT protective layer 108, but the contact hole and the external wiring (not shown) connected to the contact hole are uneven. Vi) As described in the sealing section, by reducing the viscosity of the ultraviolet curable resin, the unevenness can be sufficiently covered, and conversely, the adhesion area is increased. Further, a sufficient sealing margin Lf for maintaining a strong seal can be secured.

  FIG. 3 is a cross-sectional view of the light emitting element substrate according to the first embodiment of the present invention when the sealing portion is expanded to a contact hole with an external circuit and an external wiring region.

  Hereinafter, a configuration in the case where the sealing portion 10 is expanded to a contact hole with an external circuit and an external wiring region will be described with reference to FIG. In FIG. 3, the light emitting layer 6 and the cathode 7 shown in FIG. 2 are not shown, but this is because the sealing margin Lf indicating the distance between the end of the light emitting layer 6 and the outermost periphery of the sealing portion 10 is sufficient. This is because the light emitting layer 6 and the cathode 7 do not exist in the region shown in FIG.

  In FIG. 3, reference numeral 119 denotes a wiring pattern provided on the gate insulating layer 103. 110 is a contact hole provided as an opening in the TFT protective layer 108 for connection to an external circuit (not shown), and 120 is connected to the contact hole 110 to connect the wiring pattern 119 and the external circuit (not shown). External wiring. In FIG. 3, only one contact hole 110 and one external wiring 120 are shown. However, in the actual light emitting element substrate 70, a plurality of these are provided in a direction perpendicular to the paper surface. Therefore, the surface of the TFT protective layer 108 has irregularities due to the presence or absence of the external wiring 120.

  In the first embodiment, the light emitting element substrate 70 has a wiring portion (external wiring 120) for inputting at least a control signal related to driving of the light emitting portion LS (see FIG. 1), and the sealing portion covers the external wiring 120. 10 is bonded.

  The external wiring 120 formed on the TFT protective layer 108 is based on ITO, and has a multilayer structure in which a metal layer such as molybdenum is provided to reduce the wiring resistance thereon. Etc. can be formed. The thickness of the external wiring thus formed is about 150 to 200 nanometers.

  The unevenness formed by the external wiring 120 having a thickness of about 200 nanometers at most is completely filled with the sealing portion 10, and as a result, the unevenness formed by the contact hole 110 and the external wiring 120 is conversely the substrate 2 and the sealing portion. 10 to increase the bonding area. In addition, since the TFT protective layer 108 is formed by a dry process such as sputtering, the metal oxide or metal nitride constituting the TFT protective layer 108 is buried very densely and has a permeability to moisture and gas. There is nothing.

  In Example 1, since at least the outer peripheral portion of the sealing portion 10 is adhered on the TFT protective layer 108 formed in this manner, the sealing portion 10 adheres to the TFT protective layer 108 very stably. Is done.

viii) Overall Configuration of Light-Emitting Element Substrate FIG. 4A is a top view of the light-emitting element substrate of Example 1 of the present invention, and FIG. 4B is an enlarged view of the main part of the light-emitting element substrate of Example 1 of the present invention. FIG. Hereinafter, the configuration of the light-emitting element substrate 70 in Example 1 will be described in detail with reference to FIG.

  In FIG. 4, a light emitting element substrate 70 is a rectangular substrate having a thickness of about 0.7 millimeters and having at least a long side and a short side. A plurality of organic light emitting elements are arranged in the long side direction (main scanning direction). The electroluminescence elements 1 are formed in a row. As described above, the light emitting portion (not shown) of the organic electroluminescence element 1 is made of a polymer organic electroluminescence material.

  In the first embodiment, light emitting elements necessary for at least A4 size (210 millimeter) exposure are arranged in the long side direction of the light emitting element substrate 70, and the long side direction of the light emitting element substrate 70 is an arrangement space of a drive control unit 78 described later. Including 250 mm. In the first embodiment, the light emitting element substrate 70 is described as a rectangle for the sake of simplicity. However, the positioning of the light emitting element substrate 70 is not limited for the purpose of positioning when the light emitting element substrate 70 is attached to a housing A74a of an exposure apparatus described later. It may be accompanied by such a deformation that a part is notched.

  A drive control unit 78 receives a control signal (a signal for driving the organic electroluminescence element 1) supplied from the outside of the light emitting element substrate 70, and controls the driving of the organic electroluminescence element 1 based on the control signal. And includes an interface means (FPC 80) for receiving a control signal from the outside of the light emitting element substrate 70 and an IC chip (source driver 81) for controlling the driving of the light emitting element based on the control signal received through the interface means, as will be described later. It is out.

  Reference numeral 80 denotes an FPC (flexible printed circuit) as an interface means for connecting the connector A 73a of the relay substrate 72 and the light emitting element substrate 70, and is directly connected to a circuit pattern (not shown) provided on the light emitting element substrate 70 without using a connector or the like. Has been. As already described, image data, light amount correction data, control signals such as clock signals and line synchronization signals, drive power supply for the control circuit, and drive of the organic electroluminescence element 1 which is a light emitting element are supplied to the exposure apparatus 33 from the outside. The power is supplied to the light emitting element substrate 70 via the FPC 80 after passing through the relay substrate 72 shown in FIG.

  In Example 1, 5120 organic electroluminescence elements 1 as light sources of an exposure apparatus to be described later are formed in a row at a resolution of 600 dpi in the longitudinal direction of the light emitting element substrate 70 (main scanning direction). The electroluminescence elements 1 are independently controlled to be turned on / off by a TFT circuit described later.

  Reference numeral 81 denotes a source driver supplied as an IC chip for controlling the driving of the organic electroluminescence element 1, and is flip-chip mounted on the light emitting element substrate 70. Considering that surface mounting is performed on the glass surface, the source driver 81 employs a bare chip product. The source driver 81 is supplied with control-related signals such as a power supply, a clock signal, and a line synchronization signal and light amount correction data (for example, 8-bit multi-value data) from the outside of the exposure apparatus 33 via the FPC 80. As will be described in detail later, the source driver 81 is a drive parameter setting unit for the organic electroluminescence element 1. More specifically, the source driver 81 is based on the light amount correction data passed through the FPC 80. This is for setting the drive current value.

  In the light emitting element substrate 70, the joint portion of the FPC 80 and the source driver 81 are connected through, for example, an ITO circuit pattern (not shown) having a metal formed on the surface, and the FPC 80 is connected to the source driver 81 as drive parameter setting means. Control signals such as light quantity correction data, a clock signal, and a line synchronization signal are input via the. As described above, the FPC 80 as the interface means and the source driver 81 as the drive parameter setting means constitute the drive control unit 78.

  Reference numeral 108 denotes the TFT protective layer already described, and a TFT (Thin Film Transistor) circuit (not shown) is formed under the surface of the TFT protective layer 108. The TFT circuit includes a shift register, a data latch unit, and the like, a gate controller that controls the timing of turning on / off the light emitting elements, and a driving circuit (hereinafter referred to as a pixel circuit) that supplies a driving current to each organic electroluminescence element 1. Is included. One pixel circuit is provided for each organic electroluminescence element 1 and is arranged in parallel with the light emitting element row formed by the organic electroluminescence element 1. As will be described later in detail, a drive current value for driving each organic electroluminescence element 1 is set in the pixel circuit by a source driver 81 as drive parameter setting means.

  A TFT circuit (not shown) is supplied with a control signal such as a power supply, a clock signal, and a line synchronization signal and image data (1-bit binary data) from the outside of the exposure apparatus (not shown) via the FPC 80. The TFT circuit (not shown) controls the lighting / extinguishing timing of each light emitting element based on these power supplies and signals.

  A contact hole 110 is formed in the TFT protective layer 108, and an external wiring 120 is connected to the contact hole 110. In FIG. 4, for easy explanation, the organic electroluminescence element 1, the contact hole 110, and the external wiring 120 are drawn so as to be visible. Can not.

  FIG. 4 shows a case where the sealing portion 10 covers the entire contact hole 110 and a part of the external wiring 120, and corresponds to the configuration described with reference to FIG. Yes.

  In the first embodiment, as shown in FIG. 4, the TFT protective layer 108 is provided with a contact hole 110 as an opening and connected to the source driver 81 via the external wiring 120 made of ITO + metal. The source driver 81 is extended to the arrangement area, and an opening of the contact hole 110 is provided at a position corresponding to a signal terminal (bump part) of the source driver 81 which is an IC chip (bare chip), and the source driver 81 is directly joined thereto. You may comprise.

  In this way, the external wiring 120 can be simultaneously formed in the process of creating the TFT circuit, and the manufacturing process of the light emitting element substrate 70 can be simplified. Similarly, a wiring between the junction portion of the FPC 80 and the source driver 81 can also be provided under the TFT protective layer 108.

  Reference numeral 77 denotes a light quantity sensor unit in which a plurality of light quantity sensors made of amorphous silicon or the like are arranged along the light emitting element substrate 70 in the main scanning direction. The amount of light emitted from each organic electroluminescence element 1 is measured by the light amount sensor unit 77. The output of the light amount sensor unit 77 is once taken into a TFT circuit (not shown) by a wiring (not shown), subjected to signal processing such as amplification and analog-digital conversion, and then output to the outside of the light emitting element substrate 70 via the FPC 80. .

  This signal is received and processed by a controller 61 (see FIG. 5), which will be described later, to generate light amount correction data (for example, 8 bits), and the light emission amounts of all the organic electroluminescence elements 1 are controlled to be substantially equal. .

  In the first embodiment, the FPC 80 serving as the interface means constituting the drive control unit 78 and the source driver 81 serving as the drive parameter setting means in the light emitting element substrate 70 are arranged on the extension line (EL_dir) of the light emitting element row formed by the organic electroluminescence element 1. ).

  With such an arrangement, the drive control unit 78 is arranged at a position that does not overlap the light emitting element array at an arbitrary position in the long side direction (main scanning direction) of the light emitting element substrate 70. At the same time, in this configuration, at an arbitrary position in the long side direction (main scanning direction) of the light emitting element substrate 70, the drive control unit 78 is positioned so as not to overlap with a TFT circuit (not shown) formed in parallel with the light emitting element array. Will be placed.

  Furthermore, since the sealing unit 10 does not use a bathtub-shaped glass plate or the like as in the prior art, and only a necessary region of the light emitting element substrate 70 is used for sealing, the arrangement of the drive control unit 78 described above. As a result, the size of the light-emitting element substrate 70, particularly the size in the sub-scanning direction, can be reduced.

  In general, when a TFT circuit is configured on a glass substrate or the like, the number of substrates obtained from a mother glass of a predetermined size has the most influence on the cost as well as simplifying the manufacturing process. Therefore, by reducing the size of the light emitting element substrate 70, the manufacturing cost of the light emitting element substrate 70 can be dramatically reduced.

ix) Lighting control of organic electroluminescence element and size of light-emitting element substrate FIG. 5 is a circuit diagram relating to the light-emitting element substrate of Example 1 of the present invention. Hereinafter, the lighting control by the TFT circuit and the source driver 81 will be described in more detail with reference to FIG.

  In FIG. 5, reference numeral 82 denotes a TFT circuit configured on the light emitting element substrate 70. Reference numeral 61 denotes a controller incorporated in the image forming apparatus, which receives image data from a computer (not shown) or the like and generates printable image data, and as described above, the light amount sensor unit 77 disposed on the light emitting element substrate 70. Light amount correction data is generated based on the output (see FIG. 4).

  An image memory 85 stores binary image data generated by the controller 61 based on a command transferred from a computer (not shown). A light amount correction data memory 86 stores light amount correction data. The light quantity correction data memory 86 is a rewritable nonvolatile memory such as an EEPROM. In the manufacturing process of the exposure apparatus 33, the light emission amount and the light emission luminance distribution of all the organic electroluminescence elements 1 are measured for each exposure apparatus 33, and the light emission of each organic electroluminescence element 1 is based on these measurement results. A step of generating light amount correction data for making the light amounts substantially equal is included, and the light amount correction data memory 86 stores the value of the light amount correction data.

  The controller 61 can update the light amount correction data to the light amount correction data newly generated based on the output of the light amount sensor unit 77 (see FIG. 4) described above.

  A timing generation unit 87 generates a control signal related to timing for driving the organic electroluminescence element 1 formed on the light emitting element substrate 70. The image data stored in the image memory 85 and the light amount correction data stored in the light amount correction data memory 86 (or copied in advance to another high-speed memory not shown) are the clock signal and line generated by the timing generation unit 87. Based on the synchronization signal and the like, the light is supplied to the light emitting element substrate 70 through the cable 76, the connector B 73b, the relay substrate 72, the connector A 73a, and the FPC 80 which will be described later with reference to FIG.

  Further, the image data and the timing signal supplied to the light emitting element substrate 70 are supplied to the TFT circuit 82 through a wiring formed on the light emitting element substrate 70, for example, a metal layer on ITO, and the light quantity correction data and Similarly, the timing signal is supplied to the source driver 81.

  The TFT circuit 82 is roughly divided into a pixel circuit 89 and a gate controller 88. One pixel circuit 89 is provided for each organic electroluminescence element 1, and N groups are provided on the light emitting element substrate 70 with the M pixels of the organic electroluminescence element 1 as one group. In the first embodiment, one group is 8 pixels (that is, M = 8), and this group is 640. Therefore, the total number of pixels is 8 × 640 = 5120 pixels.

  Each pixel circuit 89 supplies a current to the organic electroluminescent element 1 to drive the driver unit 90, and a current value supplied by the driver to control the lighting of the organic electroluminescent element 1 (that is, a driving current value of the organic electroluminescent element 1) ) Is stored in a capacitor included therein, and the organic electroluminescence element 1 can be driven at a constant current according to a drive current value programmed in advance at a predetermined timing.

  The gate controller 88 includes a shift register that sequentially shifts input binary image data, and a latch unit that is provided in parallel with the shift register and collectively holds the input after a predetermined number of pixels are input to the shift register. The control unit controls these operation timings (both not shown). Further, the gate controller 88 outputs SCAN_A and SCAN_B signals, thereby controlling the timing of turning on / off the organic electroluminescence element 1 connected to the pixel circuit 89 and the current program period for setting the drive current.

  On the other hand, the source driver 81 has a number of D / A converters 92 corresponding to the number N of groups of the organic electroluminescence elements 1 (640 in the first embodiment), and the source driver 81 is supplied via the FPC 80. Based on the light intensity correction data (for example, 8 bits), the drive current for each organic electroluminescence element 1 is set to control the light emission luminance of each organic electroluminescence element 1 to be substantially equal.

  Next, the size of the light emitting element substrate 70 will be described with reference to FIGS. 4 and 2 in FIG. In the exposure apparatus equipped with the light emitting element substrate 70, if an exposure range of A4 size (about 210 millimeters) is obtained at a resolution of 600 dpi in the main scanning direction, 5120 organic EL elements 63 are necessary as described above. However, the scale of the TFT circuit 82 for driving these pixels is about 500,000 gates according to the study by the present inventors. When this is formed with a process rule of 4.5 micrometers, the shift register, latch part, and other control system circuits included in the gate controller 88 are about 1000 micrometers wide and the pixel circuit 89 is 200 micrometers wide. Is required in the sub-scanning direction.

  The wiring from the source driver 81 to the pixel circuit 89 can be suppressed to 1500 micrometers by multilayering the routing in the intermediate layer 105 (see FIG. 1) where the TFT circuit 82 is formed, for example. Then, the width of the TFT circuit in the sub-scanning direction can be set to about 2700 micrometers. That is, the TFT circuit 82 is formed with a width of 2700 micrometers in the direction from the organic electroluminescence element 1 to the contact hole 110 in FIG.

  As described with reference to FIG. 2, in the light emitting element substrate 70 of Example 1, the sealing margin Lf is 2000 micrometers and exhibits sufficient sealing performance. Therefore, as shown in FIG. 4, when the sealing margin Lf in the direction from the organic electroluminescence element 1 to the light quantity sensor unit 77 is also 2000 micrometers, either the TFT circuit 82 or the sealing margin Lf exists in the sub-scanning direction. The width is about 4700 micrometers. If the area of the external wiring 120 shown in FIG. 4 is added to this, the size of the light emitting element substrate 70 in the sub-scanning direction can be realized with about 5 millimeters.

  On the other hand, the width of the source driver 81 in the sub-scanning direction can be suppressed to about 3000 micrometers when the 640 D / A converters 72 are mounted (the width in the main scanning direction is about 16000 micrometers). . As already described, since the source driver 81 is mounted on the light emitting element substrate 70 at a position on the extended line of the light emitting element array, the width of the source driver 81 restricts the size of the light emitting element substrate 70 in the sub-scanning direction. There is no.

  As described above, the light emitting element substrate 70 of Example 1 has a very small size in the sub-scanning direction, the size of the exposure apparatus is reduced as described later, and the size of the image forming apparatus can be further reduced. .

x) Exposure apparatus FIG. 6 is a block diagram of an exposure apparatus on which the light emitting element substrate according to Embodiment 1 of the present invention is mounted. Hereinafter, the structure of the exposure apparatus will be described in detail with reference to FIG.

  In FIG. 6, reference numeral 33 denotes an exposure apparatus mounted on the image forming apparatus, on which the light-emitting element substrate 70 already described is mounted. On the light emitting element substrate 70, a light emitting element, that is, an organic electroluminescence element 1 (see FIG. 1) as an exposure light source is formed with a resolution of 600 dpi (dot per inch) in a direction (main scanning direction) perpendicular to the drawing.

  Reference numeral 71 denotes a lens array in which rod lenses (not shown) made of plastic or glass are arranged in a row, and the light emitted from the organic electroluminescence element 1 formed on the light emitting element substrate 70 is erecting at an equal magnification. As an image, it is guided to the surface of the photoreceptor 28 where a latent image is formed. One focal point of the lens array 71 is the surface A of the substrate 2 constituting the light emitting element substrate 70, and the other focal point of the light emitting element substrate 70, the lens array 71, and the photosensitive member 28 is the surface of the photosensitive member 28. The positional relationship has been adjusted. That is, when the distance L1 from the surface A of the substrate 2 to the surface closer to the lens array 71 and the distance L2 from the other surface of the lens array 71 to the surface of the photoconductor 28, L1 = L2. Is set.

  Reference numeral 72 denotes a relay substrate using, for example, a glass epoxy substrate. 73 a is a connector A, 73 b is a connector B, and at least a connector A 73 a and a connector B 73 b are mounted on the relay board 72. The relay substrate 72 temporarily relays image data, light amount correction data, and other control signals supplied from the outside to the exposure apparatus 33 via a cable 76 such as a flexible flat cable, etc., via a connector B 73b, and these signals are light emitting elements. Passed to the substrate 70.

  Since it is difficult to directly mount the connector on the surface of the substrate 2 constituting the light emitting element substrate 70 in consideration of bonding strength and reliability in various environments where the exposure apparatus 33 is placed, in the first embodiment, the relay substrate 72 is used. FPC (flexible printed circuit) is employed as a connection means between the connector A73a and the light emitting element substrate 70 (not shown), and the light emitting element substrate 70 and FPC are joined using, for example, an ACF (anisotropic conductive film). For example, it is configured to be directly connected to, for example, an ITO (indium tin oxide) electrode formed on the light emitting element substrate 70 in advance.

  On the other hand, the connector B 73b is a connector for connecting the exposure apparatus 33 to the outside. In general, connection by ACF or the like often has a problem of bonding strength, but by providing the connector B73b for connecting the exposure apparatus 33 on the relay substrate 72 in this way, the interface directly accessed by the user is provided. Sufficient strength can be ensured.

  A housing 74a is formed by bending a metal plate, for example. An L-shaped portion 75 is formed on the side of the housing 74 a facing the photoreceptor 28, and the light emitting element substrate 70 and the lens array 71 are disposed along the L-shaped portion 75. The end surface of the housing 74a on the photosensitive member 28 side and the end surface of the lens array 71 are aligned with each other, and the end portion of the light emitting element substrate 70 is supported by the housing 74a, thereby forming the L-shaped portion 75. If the accuracy is ensured, the positional relationship between the light emitting element substrate 70 and the lens array 71 can be accurately adjusted.

  As described above, since the casing 74a is required to have a dimensional accuracy, it is desirable that the casing 74a be made of metal. Further, by making the housing 74a made of metal, the influence of noise on electronic components such as a control circuit using a TFT formed on the light emitting element substrate 70 and an IC chip surface-mounted on the light emitting element substrate 70 can be reduced. It is possible to suppress.

  74b is a casing obtained by molding a resin. A notch (not shown) is provided in the vicinity of the connector 73b of the housing 74b, and the user can access the connector 73b from this notch. The image data, the light amount correction data, the control signal such as the clock signal and the line synchronization signal, the driving power source of the control circuit, and the organic light emitting element are supplied from the outside of the exposure apparatus 33 to the exposure apparatus 33 through the cable 76 connected to the connector 73b. Drive power for the electroluminescence element is supplied.

  Now, as already described in ix) Lighting control of organic electroluminescence elements and the size of the light emitting element substrate, the width in the sub-scanning direction of the light emitting element substrate 70 (see FIG. 4) of Example 1 should be about 5 millimeters. Therefore, the thickness Z of the exposure apparatus 33 on which the light emitting element substrate 70 is mounted can be reduced to 7 millimeters or less by making the thickness of the housing A74a and the housing B74b less than 1 millimeter.

xi) Configuration of Image Forming Apparatus FIG. 7 is a block diagram of an image forming apparatus equipped with an exposure apparatus to which the light emitting element substrate of Example 1 of the present invention is applied.

  In FIG. 7, an image forming apparatus 21 has four color developing stations, a yellow developing station 22Y, a magenta developing station 22M, a cyan developing station 22C, and a black developing station 22K, arranged in a stepwise manner in the vertical direction. Is provided with a paper feed tray 24 in which recording paper 23 is accommodated, and a recording paper transport path serving as a transport path for the recording paper 23 supplied from the paper feed tray 24 at locations corresponding to the developing stations 22Y to 22K. 25 is arranged vertically from above to below.

  The developing stations 22Y to 22K form yellow, magenta, cyan, and black toner images in order from the upstream side of the recording paper conveyance path 25. The yellow developing station 22Y includes a photoconductor 28Y and a magenta developing station 22M. The photosensitive member 28M and the cyan developing station 22C include the photosensitive member 28C, the black developing station 22K includes the photosensitive member 28K, and each developing station 22Y to 22K includes a series of electrophotographic systems such as a developing sleeve and a charger (not shown). The member which implement | achieves the image development process in is included.

  Further, exposure devices 33Y, 33M, 33C, and 33K for exposing the surfaces of the photoreceptors 28Y to 28K to form electrostatic latent images are disposed below the developing stations 22Y to 22K.

  The developing stations 22Y to 22K are different in the color of the filled developer, but the configuration is the same regardless of the development color. Therefore, unless particularly necessary to simplify the following description, A description will be given without clearly showing specific colors such as the developing station 22, the photoreceptor 28, and the exposure device 33.

  FIG. 8 is a configuration diagram illustrating the periphery of the developing station in the image forming apparatus according to the first exemplary embodiment of the present invention. In FIG. 8, the developing station 22 is filled with a developer 26 which is a mixture of carrier and toner. Reference numerals 27a and 27b denote stirring paddles for stirring the developer 26. The toner in the developer 26 is charged to a predetermined potential by friction with the carrier by the rotation of the stirring paddles 27a and 27b, and the interior of the developing station 22 is also charged. By circulating, the toner and the carrier are sufficiently stirred and mixed. The photoreceptor 28 is rotated in the direction D3 by a driving source (not shown).

  A charger 29 charges the surface of the photoreceptor 28 to a predetermined potential. 30 is a developing sleeve, and 31 is a thinning blade. The developing sleeve 30 has a magnet roll 32 having a plurality of magnetic poles formed therein. The layer thickness of the developer 26 supplied to the surface of the developing sleeve 30 is regulated by the thinning blade 31 and the developing sleeve 30 is rotated in the direction D4 by a driving source (not shown). As a result, the developer 26 is supplied to the surface of the developing sleeve 30, and an electrostatic latent image formed on the photoconductor 28 is developed by an exposure device described later, and the developer 26 not transferred to the photoconductor 28 is developed. It is collected inside the station 22.

  Reference numeral 33 denotes the exposure apparatus already described. As already described, since the light emitting element substrate 70 (see FIG. 4) mounted on the exposure apparatus 33 has excellent sealing performance and can form a latent image stably over a long period of time, it is a product as an exposure apparatus. Since the lifetime is long and an electrostatic latent image of a desired shape can be obtained over a long period of time, a high-quality image can always be formed.

  As described above, the exposure apparatus 33 according to the first embodiment includes the organic electroluminescence elements 1 arranged linearly at a resolution of 600 dpi (dot per inch), and is a photosensitive member charged to a predetermined potential by the charger 29. An electrostatic latent image having a maximum A4 size is formed on the body 28 by selectively turning on / off the organic electroluminescence element according to the image data. Only the toner of the developer 26 supplied to the surface of the developing sleeve 30 adheres to the electrostatic latent image portion, and the electrostatic latent image is visualized.

  A transfer roller 36 is provided at a position facing the recording paper conveyance path 25 with respect to the photoreceptor 28, and is rotated in the direction D5 by a driving source (not shown). A predetermined transfer bias is applied to the transfer roller 36, and the toner image formed on the photoconductor 28 is transferred to the recording paper 23 conveyed through the recording paper conveyance path 25.

  Subsequently, returning to FIG.

  As described above, the image forming apparatus 21 according to the first exemplary embodiment is a tandem type color image forming apparatus in which a plurality of developing stations 22Y to 22K are arranged in a stepwise manner in the vertical direction, and is equivalent to a color inkjet printer. It aims at size. Since a plurality of units are arranged in the developing stations 22Y to 22K, in order to reduce the size of the image forming apparatus 21, the developing stations 22Y to 22K themselves are reduced in size and are arranged around the developing stations 22Y to 22K. It is necessary to reduce the members involved in the image process and to reduce the arrangement pitch of the developing stations 22Y to 22K as much as possible.

  In consideration of user convenience when installing the image forming apparatus 21 on the desktop in an office or the like, in particular, accessibility to the recording paper 23 at the time of paper feed or paper discharge, from the bottom surface of the image forming apparatus 21 to the paper feed port 65. The height is preferably 250 mm or less. In order to realize this, it is necessary to suppress the height of the entire developing stations 22Y to 22K to about 100 millimeters in the entire configuration of the image forming apparatus 21. However, the existing LED head, for example, has a thickness of about 15 millimeters, and if it is disposed between the developing stations 22Y to 22K, it is difficult to achieve the target.

  According to the examination results of the present inventors, when the thickness of the exposure device 33 is 7 millimeters or less, the height of the entire development station is 100 millimeters even if the exposure devices 33Y to 33K are arranged in the gaps between the development stations 22Y to 22K. The following can be suppressed. x) As described in the exposure apparatus, since the thickness Z of the exposure apparatus 33 of Embodiment 1 is less than 7 millimeters, the height of the entire developing station is set to 100 millimeters or less, and a very small image forming apparatus 21 is configured. It becomes possible to do.

  A toner bottle 37 stores yellow, magenta, cyan, and black toners. A toner transport pipe (not shown) is provided from the toner bottle 37 to each of the developing stations 22Y to 22K, and supplies toner to each of the developing stations 22Y to 22K.

  A paper feed roller 38 is rotated in the direction D1 by controlling an electromagnetic clutch (not shown), and feeds the recording paper 23 loaded in the paper feeding tray 24 to the recording paper transport path 25.

  A registration paper 39 and a pair of pinch rollers 40 are provided as a nip conveyance means on the inlet side in the recording paper conveyance path 25 positioned between the paper supply roller 38 and the transfer portion of the most upstream yellow developing station 22Y. The registration roller 39 and the pinch roller 40 pair temporarily stop the recording paper 23 conveyed by the paper supply roller 38 and convey it in the direction of the yellow developing station 22Y at a predetermined timing. This temporary stop restricts the leading edge of the recording paper 23 in parallel with the axial direction of the registration roller 39 and pinch roller 40 pair, thereby preventing the recording paper 23 from skewing.

  Reference numeral 41 denotes a recording paper passage detection sensor. The recording paper passage detection sensor 41 is constituted by a reflective sensor (photo reflector), and detects the leading edge and the trailing edge of the recording paper 23 based on the presence or absence of reflected light.

  When the rotation of the registration roller 39 is started (the power transmission is controlled by an electromagnetic clutch (not shown) and the rotation is turned on / off), the recording paper 23 is conveyed along the recording paper conveyance path 25 in the direction of the yellow developing station 22Y. However, the timing of writing the electrostatic latent images by the exposure devices 33Y to 33K arranged in the vicinity of the developing stations 22Y to 22K is controlled independently from the timing of starting the rotation of the registration roller 39.

  A fixing device 43 is provided as a nip conveying means on the outlet side in the recording paper conveyance path 25 located further downstream of the most downstream black developing station 22K. The fixing device 43 includes a heating roller 44 and a pressure roller 45. The heating roller 44 is a multi-layered roller composed of a heating belt, a rubber roller, and a core material (both not shown) in order from the surface. Among them, the heat generating belt is a belt having a three-layer structure, and is composed of a release layer, a silicon rubber layer, and a base material layer (both not shown) from the side closer to the surface. The release layer is made of a fluororesin having a thickness of about 20 to 30 micrometers and imparts release properties to the heating roller 44. The silicon rubber layer is made of silicon rubber having a thickness of about 170 micrometers and gives the pressure roller 45 appropriate elasticity. The base material layer is made of a magnetic material that is an alloy of iron, nickel, chromium, or the like.

  A back core 26 includes an exciting coil. Inside the back core 46, an excitation coil in which a predetermined number of copper wires (not shown) whose surfaces are insulated is bundled in the direction of the rotation axis of the heating roller 44, and at both ends of the heating roller 44, the heating roller It circulates along the circumferential direction of 44. When an alternating current of about 30 kHz is applied to the exciting coil from an exciting circuit (not shown) that is a semi-resonant inverter, a magnetic flux is generated in a magnetic path constituted by the back core 46 and the base layer of the heating roller 44. Due to this magnetic flux, an eddy current is formed in the base material layer of the heat generating belt of the heating roller 44 and the base material layer generates heat. The heat generated in the base material layer is transmitted to the release layer through the silicon rubber layer, and the surface of the heating roller 44 generates heat.

  Reference numeral 47 is a temperature sensor for detecting the temperature of the heating roller 44. The temperature sensor 47 is a ceramic semiconductor obtained by sintering at a high temperature using a metal oxide as a main raw material, and it is possible to measure the temperature of a contacted object by applying a change in load resistance according to the temperature. it can. The output of the temperature sensor 47 is input to a control device (not shown). The control device controls the power output to the exciting coil inside the back core 46 based on the output of the temperature sensor 47, and the surface temperature of the heating roller 44 is about 170 ° C. Control to be

  When the recording paper 23 on which the toner image is formed is passed through the nip formed by the heating roller 44 and the pressure roller 45 that are controlled in temperature, the toner image on the recording paper 23 is connected to the heating roller 44. The toner image is fixed on the recording paper 23 by being heated and pressurized by the pressure roller 45.

  A recording paper trailing edge detection sensor 48 monitors the discharge state of the recording paper 23. Reference numeral 52 denotes a toner image detection sensor. The toner image detection sensor 52 is a reflective sensor unit that uses a plurality of light emitting elements (both visible light) having different emission spectra and a single light receiving element, and changes the image color between the background of the recording paper 23 and the image forming portion. Accordingly, the image density is detected by utilizing the fact that the absorption spectrum is different. Further, since the toner image detection sensor 52 can detect not only the image density but also the image forming position, the image forming apparatus 21 according to the first exemplary embodiment is provided with two toner image detection sensors 52 in the width direction of the image forming apparatus 21, and recording paper. The image formation timing is controlled based on the detection position of the image position deviation amount detection pattern formed on the image 23.

  53 is a recording paper transport drum. The recording paper transport drum 53 is a metal roller whose surface is covered with rubber having a thickness of about 200 micrometers, and the recording paper 23 after fixing is transported along the recording paper transport drum 53 in the direction D2. At this time, the recording sheet 23 is cooled by the recording sheet conveying drum 53 and is bent and conveyed in the direction opposite to the image forming surface. As a result, curling that occurs when a high density image is formed on the entire surface of the recording paper can be greatly reduced. Thereafter, the recording paper 23 is conveyed in the direction D6 by the kicking roller 55 and discharged to the paper discharge tray 59.

  Reference numeral 54 denotes a face-down paper discharge unit. The face-down paper discharge unit 54 is configured to be rotatable about the support member 56. When the face-down paper discharge unit 54 is opened, the recording paper 23 is discharged in the direction D7. In the closed state, the face-down paper discharge unit 54 is formed with ribs 57 along the transport path on the back surface so as to guide the transport of the recording paper 23 together with the recording paper transport drum 53.

  Reference numeral 58 denotes a drive source. In the first embodiment, a stepping motor is employed. By the drive source 58, peripheral portions of the developing stations 22Y to 22K including the paper feed roller 38, the registration roller 39, the pinch roller 40, the photoconductors (28Y to 28K), and the transfer rollers (36Y to 36K), the fixing device 43, The recording paper transport drum 53 and the kicking roller 55 are driven.

  Reference numeral 61 denotes a controller that receives image data from a computer (not shown) via an external network, and develops and generates printable image data.

  Reference numeral 62 denotes an engine control unit. The engine control unit 62 controls the hardware and mechanism of the image forming apparatus 21, forms a color image on the recording paper 23 based on the image data transferred from the controller 61, and performs overall control of the image forming apparatus 21. Yes.

  63 is a power supply unit. The power supply unit 63 supplies power of a predetermined voltage to the exposure devices 33Y to 33K, the drive source 58, the controller 61, and the engine control unit 62, and also supplies power to the heating roller 44 of the fixing device 43. The power supply unit also includes a so-called high-voltage power supply system such as charging of the surface of the photoconductor 28, a developing bias applied to the developing sleeve (see reference numeral 30 in FIG. 8), and a transfer bias applied to the transfer roller 36.

  The power supply unit 63 includes a power supply monitoring unit 64 so that at least the power supply voltage supplied to the engine control unit 62 can be monitored. This monitor signal is detected by the engine control unit 62 to detect a decrease in power supply voltage that occurs when the power switch is turned off or a power failure occurs.

  In the above description, the case where the present invention is applied to a color image forming apparatus has been described. However, the present invention can also be applied to a monochrome image forming apparatus such as black. Further, when applied to a color image forming apparatus, development colors are not limited to four colors of yellow, magenta, cyan, and black.

  The light emitting device of the present invention and the exposure apparatus and image forming apparatus using the same reliably protect the organic electroluminescence element from moisture and gas in the external atmosphere despite the simple structure, and generate shrinking and dark spots. In addition, since it is possible to effectively prevent enlargement, it can be used in various apparatuses that need to obtain stable light emission over a long period of time, and can be applied to, for example, a copying machine, a multifunction printer, a printer, and a facsimile machine. . In addition, since organic electroluminescent elements can obtain the three primary colors of Red, Green, and Blue by selecting an organic light-emitting material, for example, if an exposure apparatus that exposes each color of RGB is used, an image of a type that directly exposes photographic paper. It can also be applied to a forming apparatus. In addition, the light emitting device of the present invention is not only applicable to an exposure apparatus and an image forming apparatus, but is formed of a light emitting element such as an organic electroluminescence element and needs to be sealed, such as a display. The present invention can also be applied to a display device.

Sectional drawing which shows the structure of the organic electroluminescent element in the light emitting element substrate of Example 1 of this invention. Sectional drawing which shows the structure of the outer peripheral part of the sealing part in the light emitting element substrate of Example 1 of this invention. Sectional drawing at the time of enlarging to the area | region of the contact hole and external wiring with an external circuit in the light emitting element substrate of Example 1 of this invention (A) Top view of the light emitting element substrate of Example 1 of the present invention, (b) Enlarged view of the main part of the light emitting element substrate of Example 1 of the present invention. 1 is a circuit diagram relating to a light-emitting element substrate of Example 1 of the present invention. 1 is a configuration diagram of an exposure apparatus equipped with a light-emitting element substrate in Example 1 of the present invention. 1 is a configuration diagram of an image forming apparatus equipped with an exposure apparatus to which a light emitting element substrate according to Embodiment 1 of the present invention is applied. 1 is a configuration diagram showing the periphery of a developing station in an image forming apparatus according to Embodiment 1 of the present invention. Sectional drawing which shows the structure of the conventional organic electroluminescent element

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic electroluminescent element 2 Board | substrate 3 Anode 6 Light emitting layer 7 Cathode 8 Pixel control part 9 Sealing substrate 10 Sealing part 11 Organic electroluminescent element 12 Glass substrate 13 Anode 14 Hole transport layer 15 Organic material layer 16 Light emitting layer 17 Cathode 18 Sealing unit 21 Image forming apparatus 22, 22Y, 22M, 22C, 22K Developing station 23 Recording paper 25 Recording paper transport path 28, 28Y, 28M, 28C, 28K Photosensitive member 33, 33Y, 33M, 33C, 33K Exposure device 61 Controller 62 Engine control unit 70 Light emitting element substrate 71 Lens array 78 Drive control unit 80 FPC
81 source driver 82 TFT circuit 85 image memory 86 light quantity correction data memory 87 timing generation unit 88 gate controller 89 pixel circuit 101 base coat layer 102 TFT
DESCRIPTION OF SYMBOLS 103 Gate insulating layer 105 Intermediate layer 108 TFT protective layer 110 Contact hole 119 Wiring pattern 120 External wiring 201 Inorganic porous material 202 Inorganic filling material

Claims (5)

A first substrate having a first electrode; a light emitting part formed on the first substrate using a polymer organic electroluminescent material; a second electrode covering the light emitting part; and at least the second electrode A sealing portion made of an ultraviolet curable resin that covers a wider area than the second electrode, and the entire second substrate is connected to the second electrode of the sealing portion. A light-emitting device comprising an inorganic porous material (crystalline zeolite) bonded to the opposite side of the bonding portion and having water absorption in the sealing portion. The second substrate facing the second electrode across the sealing portion covers a wider area than the second electrode, and the area of the second substrate is larger than the second electrode, The light emitting device according to claim 1, wherein the light emitting device is smaller than the sealing portion. The light emitting device according to claim 1, wherein the second substrate is formed of a substrate having ultraviolet transparency. Forming a light-emitting portion on the first substrate having the first electrode using a polymer organic electroluminescent material, forming a second electrode covering the light-emitting portion, and at least the second electrode A step of bonding a sealing portion made of an ultraviolet curable resin containing an inorganic porous material (crystalline zeolite) covering a wider area onto the first substrate, and a step of bonding the second substrate; A method for manufacturing a light-emitting device, comprising: a step of curing the adhered ultraviolet curable resin, and including at least a heat treatment step in the step of bonding the resin constituting the sealing portion onto the substrate. After applying the polymer organic electroluminescence material on the substrate, the first heat treatment step and the ultraviolet curable resin containing the inorganic porous material (crystalline zeolite) constituting the sealing portion are adhered onto the substrate. 5. The method for manufacturing a light emitting device according to claim 4, further comprising a second heat treatment step, wherein the temperature of the second heat treatment is lower than the temperature of the first heat treatment.