JP2010240848A - Electro-optical device, exposure head, and image forming apparatus - Google Patents

Abstract

A light-emitting element is reliably deteriorated due to oxygen or moisture by making the maximum use of the fact that a light-transmitting member such as a lens array or a light-transmitting spacer is disposed on the element substrate. To provide an electro-optical device, an exposure head, and an image forming apparatus that can be prevented.
In an exposure head 10, an element substrate 11 has a first substrate surface 11a on which an organic EL element 2 is provided facing a side closed by an end plate portion 52 in a housing 5, and in this state, the element substrate 11 Between the board | substrate 11 and the inner wall of the cylindrical trunk | drum 51 of the housing 5, it seals with the 1st sealing material 8a. An open end side of the housing 5 (the other end side of the cylindrical body portion 51) is a translucent member holding portion 53 for holding the translucent member 4. In the translucent member holding portion 53, the translucent member is provided. 4 and the translucent member holding part 53 are sealed with a second sealing material 8b.
[Selection] Figure 3

Description

  The present invention relates to an electro-optical device, an exposure head, and an image forming apparatus in which a light emitting element such as an organic electroluminescence element (hereinafter referred to as EL (Electroluminescence)) is formed on an element substrate.

  As an electro-optical device in which a light-emitting element is provided on an element substrate, for example, an organic EL device can be exemplified, and such an organic EL device is used as an exposure head for forming a latent image on an image bearing surface in an image forming apparatus. Used (see, for example, Patent Documents 1 and 2).

  For example, as shown in FIG. 11A, the exposure head includes a translucent element substrate 11 in which an organic EL element 2 is provided on a first substrate surface 11a. In the element substrate 11, the lens array 40 is disposed on the second substrate surface 11b side opposite to the first substrate surface 11a, and the element substrate 11 and the lens array 40 are held by the frame 5x. Further, as shown in FIG. 11B, the exposure head includes a light-transmitting element substrate 11 in which the organic EL element 2 is provided on the first substrate surface 11 a, and the second substrate surface of the element substrate 11. In some cases, a translucent spacer 45 and a lens array 40 are disposed on the 11b side.

  In the exposure head having such a configuration, the organic EL element 2 is easily deteriorated by contact with oxygen or moisture. Therefore, a structure in which a can-shaped sealing member 5y is placed on the first substrate surface 11a side of the element substrate 11 and the side plate portion of the sealing member 5y and the element substrate 11 are sealed with the sealing material 8 is employed. There are many cases.

No. 2006-218848 2006-218849

  However, in the sealing structure shown in FIGS. 11A and 11B, the length of the seal portion is only the thickness of the side plate portion of the sealing member 5y and is short. For this reason, oxygen and moisture may enter from between the sealing member 5y and the element substrate 11 from the outside. On the other hand, when the side plate portion of the sealing member 5y is thickened and the sealing portion is lengthened, the exposure head is increased in size and the cost is increased.

  In view of the above problems, the object of the present invention is to lengthen the seal portion by making the best use of the fact that translucent members such as lens arrays and translucent spacers are arranged on the element substrate. An object of the present invention is to provide an electro-optical device, an exposure head, and an image forming apparatus that can reliably prevent deterioration of a light-emitting element due to oxygen or moisture.

  In order to solve the above-described problems, the present invention provides a translucent element substrate in which a light-emitting element is provided on a first substrate surface, and a second substrate surface side opposite to the first substrate surface in the element substrate. A translucent member provided on the electroluminescent device, wherein the light emitted from the light emitting element is emitted through the element substrate and the translucent member, and surrounds the element substrate A cylindrical body and an end plate that closes one end of the cylindrical body, and holding the translucent member with an opening that emits light transmitted through the translucent member on the other end of the cylindrical body And a first sealing material that seals between the housing and the element substrate disposed with the first substrate surface facing the end plate portion inside the housing. And a second sealing material that seals between the translucent member and the housing; Characterized in that it has a.

  In the present invention, the element substrate and the translucent member are held by a common housing. In addition, the element substrate faces the first substrate surface on which the light emitting element is provided to the side closed by the end plate portion in the housing, and in this state, the gap between the element substrate and the housing is sealed with the first sealing material. It has been stopped. The open end side of the housing (the other end side of the cylindrical body) is a translucent member holding unit for holding the translucent member. In the translucent member holding unit, the translucent member, the housing, Is sealed with a second sealing material. For this reason, since the sealing part by the 1st sealing material and the sealing part by the 2nd sealing material are provided in series between the light emitting element and the exterior, oxygen and moisture will reach the light emitting element. Since it is necessary to penetrate the sealing part by the first sealing material and the sealing part by the second sealing material, the sealing performance can be improved without changing the size of the member. Can do.

  The present invention is particularly effective when applied to the case where the light emitting element is an organic EL element. Such organic EL elements are particularly susceptible to deterioration due to oxygen and moisture, and thus the effects when the present invention is applied are remarkable.

  In the present invention, the translucent member is, for example, a lens array in which lenses that emit light emitted from the light emitting element as convergent light are integrally formed. In this case, the second sealing material employs a configuration that seals between the lens array and the housing.

  In the present invention, the translucent member includes a lens array including a lens that emits the light emitted from the light emitting element as convergent light, and a translucent spacer interposed between the lens array and the element substrate. , May have.

  In such a configuration, the second sealing material can employ a configuration in which a gap between the lens array and the housing is sealed. Further, the second sealing material may adopt a configuration in which a space between the light transmissive spacer and the housing is sealed. In the present invention, it is preferable that the second sealing material seals between the translucent spacer and the housing and between the lens array and the housing.

  In the present invention, the housing is preferably integrally formed as a whole. According to such a configuration, unlike the case where the housing is composed of a plurality of members, there is no possibility that oxygen or moisture enters between the members.

  In the present invention, the housing includes a housing body provided with the cylindrical body and the end plate, and a lid member connected to the other end of the cylindrical body with the opening. In such a configuration, it is preferable that the gap between the other end of the cylindrical body and the lid member is sealed with a third sealing material or the second sealing material.

  In the present invention, it is preferable that a getter material that captures at least one of oxygen and moisture is provided in a space defined by the first substrate surface of the element substrate and the housing. According to this configuration, when oxygen or moisture enters the space defined by the first substrate surface of the element substrate and the housing and can be captured by the getter material, the light emitting element is deteriorated by oxygen and moisture. This can be prevented more reliably.

  In the present invention, a getter material that captures at least one of oxygen and moisture is provided in a space defined by the translucent member and the housing on the second substrate surface side of the element substrate. It is preferable. According to such a configuration, even when oxygen or moisture enters the space defined by the translucent member and the housing on the second substrate surface side of the element substrate, it can be captured by the getter material. It is possible to prevent oxygen and moisture from entering the space defined by the one substrate surface and the housing. Therefore, it is possible to more reliably prevent the light emitting element from being deteriorated by oxygen or moisture.

  The electro-optical device to which the present invention is applied can be used as an exposure head of an image forming apparatus, and the image forming apparatus has an image carrier on which a latent image is formed by light emitted from the light emitting element. Yes.

  In addition to the exposure head of the image forming apparatus, the electro-optical device to which the present invention is applied uses an electronic device such as a lighting device using a light emitting element as a light source, or the electro-optical device to which the present invention is applied as a display device. It can be used for electronic devices such as mobile phones and mobile computers.

It is explanatory drawing which shows the principal part of the image printing apparatus to which this invention is applied. It is explanatory drawing of the main member used for the exposure head shown in FIG. It is explanatory drawing of the exposure head which concerns on Embodiment 1 of this invention. It is explanatory drawing of the exposure head which concerns on the modification of Embodiment 1 of this invention. It is explanatory drawing of the exposure head which concerns on Embodiment 2 of this invention. It is explanatory drawing of the exposure head which concerns on the modification of Embodiment 2 of this invention. It is explanatory drawing of the exposure head which concerns on Embodiment 3 of this invention. It is explanatory drawing of the exposure head which concerns on the modification of Embodiment 3 of this invention. 1 is a longitudinal sectional view showing an overall configuration of an image forming apparatus to which the present invention is applied. It is a longitudinal cross-sectional view which shows the whole structure of another image forming apparatus to which this invention is applied. It is explanatory drawing of the exposure head used for the conventional image forming apparatus.

  Embodiments of the present invention will be described with reference to the drawings. In the following description, an example in which an electro-optical device to which the present invention is applied is used as an exposure head of an image forming apparatus will be mainly described.

[Configuration of image printing device]
FIG. 1 is an explanatory view showing a main part of an image printing apparatus to which the present invention is applied. FIGS. 1A and 1B are an explanatory view when a lens array is used as a translucent member, and a transparent portion, respectively. It is explanatory drawing at the time of using a lens array and a translucent spacer as an optical member.

  An image forming apparatus 100 shown in FIGS. 1A and 1B is an apparatus used as a printing portion of a printer, a copier, a facsimile, or the like, and extends in a bus line direction (main scanning direction) indicated by an arrow A. It has a cylindrical photosensitive drum 110 and an exposure head 10 (electro-optical device) arranged on the outer side in the radial direction of the photosensitive drum 110. The photosensitive drum 110 includes an image bearing surface 110s on a circumferential surface (outer circumferential surface), and rotates in a direction around the axis X (direction indicated by an arrow B / sub-scanning direction). The image bearing surface 110s is irradiated with light from outside in the radial direction of the body drum 110 to form a latent image on the image bearing surface 110s.

  The exposure head 10 includes a translucent element substrate 11 in which an element formation region 28 is provided on a first substrate surface 11a, and the second substrate surface 11b on the element substrate 11 opposite to the first substrate surface 11a. A translucent member 4 is arranged on the side.

  In the image forming apparatus 100 illustrated in FIG. 1A, a lens array 40 is disposed between the element substrate 11 and the photosensitive drum 110 as the translucent member 4.

  In the image forming apparatus 100 shown in FIG. 1B, a lens array 40 is disposed between the element substrate 11 and the photosensitive drum 110 as the translucent member 4, and between the element substrate 11 and the lens array 40. A translucent spacer 45 is disposed therebetween. The translucent spacer 45 defines the distance between the element substrate 11 and the lens array 40.

(Configuration of element substrate 11 and lens array 40)
2 is an explanatory diagram of main members used in the exposure head 10 shown in FIG. 1, and FIGS. 2A, 2B, and 2C are explanatory diagrams each showing a cross-sectional configuration of the element substrate 11, and elements. FIG. 2 is an explanatory diagram showing a planar configuration of a substrate 11 and an explanatory diagram of a lens array 40.

  As shown in FIG. 2A, the exposure head 10 has an element substrate 11 on which an organic EL element 2 as a light emitting element is formed on the first substrate surface 11a side. On one substrate surface 11a, a circuit portion 3 on which a thin film transistor 15 and the like are formed is also formed. A transparent pixel electrode 24 made of ITO or the like is formed on the uppermost interlayer insulating film among the plurality of interlayer insulating films formed in the circuit unit 3. The pixel electrode 24 is electrically connected to the thin film transistor 15. Connected. An insulating layer 17 made of a silicon oxide film or the like is formed on the upper layer of the pixel electrode 24 between the adjacent pixel electrodes 24, and the insulating layer 17 partially overlaps the pixel electrode 24. . Therefore, the surface of the pixel electrode 24 is exposed at the opening of the insulating layer 17. A partition 18 made of acrylic resin, polyimide resin, or the like having a height of 1 to 3.5 μm is formed on the insulating layer 17 so as to surround the pixel electrode 24, and the region surrounded by the partition 18 Inside, the organic functional layer 20 is laminated on the upper layer side of the insulating layer 17. A cathode layer 25 is formed on the organic functional layer 20, and the pixel electrode 24, the organic functional layer 20, and the cathode layer 25 constitute the organic EL element 2. A plurality of such organic EL elements 2 are formed in the element formation region 28. In FIG. 2A, the organic EL element 2 and the thin film transistor 15 are shown at positions where they overlap, but the organic EL element 2 and the thin film transistor 15 are formed at positions shifted from each other.

The organic functional layer 20 includes, for example, a hole injection transport layer 21 stacked on the pixel electrode 24 and a light emitting layer 22 stacked on the hole injection transport layer 21. Other organic functional layers having other functions such as an interlayer layer may be provided below or above the light emitting layer 22. For example, an electron transport layer made of aluminum quinolinol (Alq ₃ ) or the like may be formed on the light emitting layer 22. The hole injection transport layer 21 has a function of injecting holes into the light emitting layer 22 and a function of transporting holes. In the light emitting layer 22, holes injected from the hole injecting and transporting layer 21 and electrons injected from the cathode layer 25 are recombined in the light emitting layer to emit light. Here, the light emitting layer 22 is configured to emit white light in all the organic EL elements 2.

  The hole injecting and transporting layer 21 is formed by discharging a liquid composition containing a hole injecting and transporting layer forming material and a solvent (including a dispersion medium) to the inside of the partition wall 18 and then removing the solvent. The light emitting layer 22 is also formed by discharging a liquid composition containing a light emitting layer forming material and a solvent (including a dispersion medium) to the inside of the partition wall 18 and then removing the solvent. Thus, when forming the positive hole injection transport layer 21 and the light emitting layer 22, the partition 18 has the function which prevents that a liquid composition protrudes outside. In such a configuration, the hole injecting and transporting layer 21 includes, for example, 3,4-polyethylenediosithiophene / polystyrenesulfonic acid (PEDOT / PSS) which is a polyolefin derivative, or polyphenylene whose polymer precursor is polytetrahydrothiophenylphenylene. It consists of organic functional materials such as vinylene and 1,1-bis- (4-N, N-ditolylaminophenyl) cyclohexane. The light emitting layer 22 is made of, for example, a polyfluorene derivative, a polyphenylene derivative, polyvinyl carbazole, a polythiophene derivative, or a polymer material thereof, a perylene dye, a coumarin dye, a rhodamine dye, such as rubrene, perylene, or 9,10-diphenyl. It consists of an organic functional material doped with anthracene, tetraphenylbutadiene, Nile red, coumarin 6, quinacridone and the like.

  Moreover, the hole injection transport layer 21 and the light emitting layer 22 may be formed by vapor deposition. In such a configuration, the hole injection transport layer 21 is made of a triarylamine (ATP) multimer or the like. The light emitting layer 22 is made of a styrylamine-based material containing an anthracene-based dopant or a rubrene-based dopant.

  The cathode layer 25 is formed on substantially the entire one surface of the element substrate 11 or in a stripe shape, and plays a role of flowing a current through the organic functional layer 20 in a pair with the pixel electrode 24. The cathode layer 25 has, for example, a structure in which a calcium layer and an aluminum layer are stacked. In this embodiment, the cathode layer 25 is in direct contact with the light emitting layer 22 and plays a role of injecting electrons into the light emitting layer 22. Depending on the material of the light emitting layer 22, the light emitting layer 22 is intended to increase the light emission efficiency. An electron injection layer such as LiF may be formed between the cathode layer 25 and the cathode layer 25.

  The exposure head 10 of this embodiment is, for example, a bottom emission type that emits light from the element substrate 11 side, and the cathode layer 25 is made of a reflective material such as Al (aluminum). Therefore, the light emitted from the organic functional layer 20 to the element substrate 11 side is emitted from the second substrate surface 11b side of the element substrate 11 as indicated by an arrow L1, and from the organic functional layer 20 to the element substrate 11. The light emitted to the opposite side is reflected by the cathode layer 25, passes through the element substrate 11 and is emitted to the lower side of the element substrate 11, as indicated by an arrow L1. Therefore, in the bottom emission type exposure head 10, a transparent element substrate such as glass, quartz, or transparent resin is used as the element substrate 11.

  The layout of the organic EL element 2 is expressed as shown in FIG. In the example shown here, on the first substrate surface 11 a of the element substrate 11, the direction orthogonal to the rotation direction of the photosensitive drum 110 (direction indicated by arrow B) (direction indicated by arrow A / bus line direction of the photosensitive drum 110). Two element rows 20 in which the organic EL elements 2 are arranged are provided in the rotation direction of the photosensitive drum 110, and the organic EL elements 2 are arranged between the element rows 20 in the bus line direction of the photosensitive drum 110. It is provided in the position shifted by. Note that there may be three or more element rows 20, for example, four rows. According to such a configuration, even if there is a limit in approaching the organic EL elements 2 to each other, the organic EL element 2 is in the same state as the proximity of the organic EL element 2 in the generatrix direction of the photosensitive drum 110. Can be achieved.

  As shown in FIG. 2C, in the lens array 40, a plurality of lenses 42 are arranged corresponding to the layout of the organic EL element 2 shown in FIG. In this embodiment, the lens 42 is a gradient index lens, and the lens array 40 is configured as a converging lens array made of glass or resin. The gradient index lens 42 is a graded index optical fiber formed such that the refractive index at the central axis, that is, the optical axis is low, and the refractive index increases as the distance from the central axis increases. The erect image can be formed on the photosensitive drum 110 by transmitting the light that has been transmitted. A specific example of such a converging lens array is, for example, SLA (Selfoc Lens Array) available from Nippon Sheet Glass Co., Ltd.

  When the lens array 40 having such a configuration is used, the distance between the light entrance of the lens array 40 and the organic EL element 2 and the distance between the light exit of the lens array 40 and the photosensitive drum 110 are made equal. There is a need. In controlling the distance, in the image forming apparatus 100 and the exposure head 10 of the type shown in FIG. 1A, the distance between the lens array 40 and the element substrate 11 is defined by a housing described later. On the other hand, in the image forming apparatus 100 and the exposure head 10 of the type shown in FIG. 1B, the distance between the lens array 40 and the element substrate 11 is defined by the translucent spacer 45. Here, a configuration in which one end of the translucent spacer 45 and the lens array 40 are joined by an adhesive 9e is employed. Moreover, the structure by which the other end of the translucent spacer 45 and the 2nd board | substrate surface 11b of the element substrate 11 are joined by the adhesive agent 9f is employ | adopted. Thus, when employ | adopting the structure joined by the adhesive agents 9e and 9f, it is preferable to use the thing with the same refractive index as the translucent spacer 45 about the adhesive agents 9e and 9f.

  In the exposure head 10 configured as described above, the organic EL element 2 deteriorates when it comes into contact with oxygen or moisture, and enters a non-lighting state. Therefore, in the exposure head 10 and the image forming apparatus 100 to which the present invention is applied, the sealing structure described below is adopted.

[Embodiment 1]
FIG. 3 is an explanatory view of the exposure head (electro-optical device) according to Embodiment 1 of the present invention, and FIGS. 3 (a), (b), (c), and (d) each illustrate the implementation of the present invention. FIG. 2 is an explanatory view showing the overall configuration of the exposure head according to the first embodiment, a bottom view of the exposure head viewed from the light emitting surface side, an explanatory view of a housing main body of the housing used for the exposure head, and a cross-sectional view of the exposure head. 3D corresponds to a cross-sectional view when the exposure head 10 is cut at a position corresponding to the line B1-B1 ′ of FIG.

  The exposure head 10 shown in FIG. 3 is of the type shown in FIG. 1A, and includes only the lens array 40 as the translucent member 4 and does not include the translucent spacer 45. For this reason, as described below, the sealing between the translucent member 4 and the housing 5 is performed between the lens array 40 and the housing 5.

  In the exposure head 10 of the present embodiment, the housing 5 includes a housing body 6 that is open at one end and a lid member 7 that covers the open end side of the housing body 6. A flexible substrate 19 is connected to the first substrate surface 11 a where the organic EL element 2 is formed on the element substrate 11.

  The housing 5 includes a cylindrical body 51 and an end plate part 52 that closes one end of the cylindrical body 51, and the light transmitted through the translucent member 4 is transmitted to the other end of the cylindrical body 51. A translucent member holding portion 53 that holds the translucent member 4 (lens array 40) with an opening 54 that emits light is provided. In this embodiment, the cylindrical body 51 has a rectangular tube shape.

  In this embodiment, an opening 54 is used as the translucent member holding portion 53, and the translucent member 4 (lens array 40) is fitted in the opening 54. Here, the housing 5 includes a housing body 6 and a lid member 7, the cylindrical body portion 51 and the end plate portion 52 are formed in the housing body 6, and the opening portion 54 and the translucent member holding portion 53 are the lid member 7. Is formed.

  In configuring the exposure head 10 using such a housing 5, the element substrate 11 is arranged with the first substrate surface 11 a on which the organic EL element 2 is formed facing the end plate portion 52. In this embodiment, a step portion 51a is formed on the inner surface of the cylindrical body portion 51 of the housing 5, and the element substrate 11 is held on the step portion 51a. As the housing 5 (housing main body 6 and lid member 7), those made of glass, metal, or resin can be used.

  In the exposure head 10 configured as described above, the space between the outer peripheral end portion of the element substrate 11 and the inner wall of the cylindrical body portion 51 is sealed by the first sealing material 8a. The space between the outer peripheral surface of the translucent member 4 (lens array 40) and the inner peripheral surface of the translucent member holding portion 53 (opening 54) is sealed with a second sealing material 8b. Further, the space between the housing body 6 and the lid member 7 is sealed with a third sealing material 8c. For the sealing materials 8a, 8b, and 8c, a resin-based sealing material such as an epoxy resin, or a glass-based sealing material using low-melting glass can be used. Here, the same material may be used for the sealing materials 8a, 8b, and 8c, but different materials may be used.

  In the housing body 6, one end 66 in the longitudinal direction is formed with a notch 67 for drawing out one end 11 s of the element substrate 11. In sealing the notch 67, the end portion 76 of the lid member 7 is bent, and the gap between the end portion 76 and the second substrate surface 11b of the element substrate 11 is sealed with the fourth sealing material 8d. . Also for the fourth sealing material 8d, a resin-based sealing material such as an epoxy resin, or a glass-based sealing material using low-melting glass can be used.

  A getter material 9 a that captures at least one of oxygen and moisture is provided in a space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5. In this embodiment, the getter material 9 a is attached to the end plate portion 52 of the housing 5. In addition, in the space 5b defined by the translucent member 4 (lens array 40) and the housing 5 on the second substrate surface 11b side of the element substrate 11, at least one of oxygen and moisture is contained in the space 5a. A getter material 9b to be captured is provided. In this embodiment, the getter material 9b is located at a position that does not block the light emitted from the organic EL element 2 among the second substrate surface 11b of the element substrate 11, the inner wall of the cylindrical body 51, and the inner surface of the lid member 7. It is attached.

In the case of using a desiccant as the getter materials 9a and 9b, the type is not limited as long as it can absorb moisture, and various types can be used. For example, as the getter materials 9a and 9b, sodium oxide (Na ₂ O), potassium oxide (K ₂ O), calcium oxide (CaO), barium oxide (BaO), magnesium oxide (MgO), lithium sulfate (Li ₂ SO) ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), cobalt sulfate (CoSO ₄ ), gallium sulfate (Ga ₂ (SO ₄ ) ₃ ), titanium sulfate (Ti ( SO _{4) 2),} nickel sulfate (NiSO _4), calcium chloride (CaCl _2), magnesium chloride (MgCl _2), strontium chloride (SrCl _2), yttrium chloride (YCl _3), copper chloride (CuCl _2), fluoride cesium (CsF), tantalum fluoride (TaF _5), niobium fluoride (NbF _5), bromide Cal Um (CaBr _2), cerium bromide (CeBr _3), bromide selenium (SEBR _4), vanadium bromide _(VBr 2), magnesium bromide (MgBr _2), barium iodide _(BaI 2), magnesium iodide ( MgI ₂ ), barium perchlorate (Ba (ClO ₄ ) ₂ ), magnesium perchlorate (Mg (ClO ₄ ) ₂ ), and the like can be used.

  When a deoxidizing material is used as the getter materials 9a and 9b, there is no limitation on the type as long as it can absorb oxygen, and various types can be used. Examples of the getter materials 9a and 9b include activated carbon, silica gel, activated alumina, molecular sieve, magnesium oxide, iron oxide, and titanium oxide.

  As the getter materials 9a and 9b, only a drying material, only a deoxidizing material, or both of them may be provided. Or you may provide getter material 9a, 9b which combines the function of both a desiccant and a deoxidation raw material like magnesium oxide.

(Main effects of this form)
As described above, in the exposure head 10 (electro-optical device) and the image forming apparatus 100 according to this embodiment, the element substrate 11 and the translucent member 4 are held by the common housing 5. In addition, the element substrate 11 faces the first substrate surface 11a on which the organic EL element 2 is provided toward the side closed by the end plate portion 52 in the housing 5, and in this state, the cylinder of the element substrate 11 and the housing 5 is placed. A space between the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a. The open end side of the housing 5 (the other end side of the cylindrical body portion 51) is a translucent member holding portion 53 for holding the translucent member 4, and in the translucent member holding portion 53, A space between the optical member 4 and the translucent member holding portion 53 is sealed with a second sealing material 8b. For this reason, since the sealing part by the 1st sealing material 8a and the sealing part by the 2nd sealing material 8b are provided in series between the organic EL element 2 and the exterior, oxygen and a water | moisture content are organic EL. In order to reach the element 2, it is necessary to penetrate the sealing portion by the first sealing material 8 a and the sealing portion by the second sealing material 8 b, so that there is no need to change the size of the member or the like. The sealing performance can be improved.

  Further, in this embodiment, the housing 5 is constituted by the housing body 6 and the lid member 7, but the space between the housing body 6 and the lid member 7 is sealed by the third sealing material 8 c. For this reason, in order for oxygen and moisture to reach the organic EL element 2 through the space between the housing body 6 and the lid member 7, the sealing portion by the first sealing material 8 a and the sealing portion by the third sealing material 8 c Therefore, the sealing performance is high.

  In this embodiment, the light transmitting member 4 (lens array 40) and the housing 5 are separated on the space 5a defined by the first substrate surface 11a of the element substrate 11 and the housing 5 and on the second substrate surface 11b side of the element substrate 11. Getter materials 9a and 9b are provided in the space 5b partitioned by. For this reason, when oxygen or moisture enters the space 5a defined by the first substrate surface 11a of the element substrate 11 and the housing 5, it can be captured by the getter material 9a, so that the organic EL element 2 can be captured by oxygen or moisture. Can be reliably prevented from deteriorating. Further, when oxygen or moisture enters the space 5b defined by the translucent member 4 (lens array 40) and the housing 5 on the second substrate surface 11b side of the element substrate 11, it can be captured by the getter material 9b. Therefore, it is possible to prevent oxygen and moisture from entering the space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5. Therefore, it is possible to more reliably prevent the organic EL element 2 from being deteriorated by oxygen or moisture.

[Modification of Embodiment 1]
FIGS. 4A and 4B are explanatory views of an exposure head (electro-optical device) according to a modification of the first embodiment of the present invention. The exposure head 10 is shown by B1-B1 in FIG. It corresponds to a cross-sectional view when cut at a position corresponding to the line '. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  The exposure head 10 shown in FIG. 4A is of the type shown in FIG. 1A, and includes only the lens array 40 as the translucent member 4 and does not include the translucent spacer 45. For this reason, as described below, the sealing between the translucent member 4 and the housing 5 is performed between the lens array 40 and the housing 5.

  In the exposure head 10, the housing 5 is integrally formed as a whole, but has substantially the same configuration as that described with reference to FIG. 3. That is, the housing 5 includes a cylindrical body 51 and an end plate part 52 that closes one end of the cylindrical body 51, and the other end side of the cylindrical body 51 is transmitted through the translucent member 4. A translucent member holding portion 53 that holds the translucent member 4 (lens array 40) with an opening 54 that emits light is provided. In this embodiment, an opening 54 is used as the translucent member holding portion 53, and the translucent member 4 (lens array 40) is fitted in the opening 54.

  In the configuration of the exposure head 10 using such a housing 5, also in this embodiment, the element substrate 11 has the first substrate surface 11 a on which the organic EL element 2 is formed as the end plate portion 52, as in the first embodiment. The gap between the element substrate 11 and the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a. Further, the space between the translucent member 4 (lens array 40) and the translucent member holding portion 53 (opening 54) is sealed with a second sealing material 8b. Furthermore, the space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5 and the light transmitting member 4 (lens array 40) and the housing 5 are defined on the second substrate surface 11 b side of the element substrate 11. Getter materials 9a and 9b are provided in the space 5b.

  The exposure head 10 shown in FIG. 4B is of the type shown in FIG. 1B, and includes a lens array 40 and a translucent spacer 45 as the translucent member 4. However, as described below, the sealing between the translucent member 4 and the housing 5 is performed between the lens array 40 and the housing 5. Here, the translucent spacer 45 and the lens array 40 are joined by an adhesive 9e, and the translucent spacer 45 and the second substrate surface 11b of the element substrate 11 are joined by an adhesive 9f. The housing 5 includes a housing main body 6 having one end open, and a lid member 7 that covers the open end of the housing main body 6.

  In the configuration of the exposure head 10 using such a housing 5, also in this embodiment, the element substrate 11 has the first substrate surface 11 a on which the organic EL element 2 is formed as the end plate portion 52, as in the first embodiment. The gap between the element substrate 11 and the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a. Further, the space between the translucent member 4 (lens array 40) and the translucent member holding portion 53 (opening 54) is sealed with a second sealing material 8b. Furthermore, the space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5 and the light transmitting member 4 (lens array 40) and the housing 5 are defined on the second substrate surface 11 b side of the element substrate 11. In the space 5b, getter materials 9a and 9b are provided.

  Therefore, even in the configuration shown in FIGS. 4A and 4B, in order for oxygen and moisture to reach the organic EL element 2, the sealing portion by the first sealing material 8a and the sealing by the second sealing material 8b are used. Since it is necessary to penetrate the portion, the same effects as those of the first embodiment, such as high sealing performance, are obtained.

[Embodiment 2]
FIG. 5 is an explanatory diagram of an exposure head (electro-optical device) according to Embodiment 2 of the present invention, and FIGS. 5 (a), (b), (c), and (d) each illustrate the implementation of the present invention. 4 is an explanatory view showing the overall configuration of the exposure head according to Embodiment 2, a bottom view of the exposure head viewed from the light emitting surface side, an explanatory view of a housing body of a housing used for the exposure head, and a cross-sectional view of the exposure head. 5D corresponds to a cross-sectional view when the exposure head 10 is cut at a position corresponding to the line B2-B2 ′ of FIG. 5B.

  The exposure head 10 shown in FIG. 5 is of the type shown in FIG. 1B and includes a lens array 40 and a light transmissive spacer 45 as the light transmissive member 4. Therefore, in this embodiment, as described below, sealing between the translucent member 4 and the housing 5 is performed between the translucent spacer 45 and the housing 5. The translucent spacer 45 and the lens array 40 are joined by an adhesive 9e, and the translucent spacer 45 and the second substrate surface 11b of the element substrate 11 are joined by an adhesive 9f. The housing 5 is an integral one.

  In the exposure head 10 shown in FIG. 5, the housing 5 includes a cylindrical body 51 and an end plate portion 52 that closes one end of the cylindrical body 51, and on the other end side of the cylindrical body 51, A translucent member holding portion 53 that holds the translucent member 4 with an opening 54 that emits light transmitted through the translucent member 4 is provided.

  In this embodiment, each of the translucent member holding portion 53 and the opening 54 is composed of an end portion on the other end side of the cylindrical body portion 51, and the translucent member 4 (translucent member) is placed in the opening 54 (the translucent member holding portion 53). The light spacer 45) is in a fitted state. Here, the translucent spacer 45 is completely accommodated inside the housing 5, and only the lens array 40 protrudes from the housing 5.

  In configuring the exposure head 10 using such a housing 5, in this embodiment, the element substrate 11 is disposed with the first substrate surface 11 a on which the organic EL element 2 is formed facing the end plate portion 52. A space between the element substrate 11 and the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a.

  In this embodiment, the entire portion of the translucent member 4 between the outer peripheral surface of the translucent spacer 45 and the translucent member holding portion 53 (opening portion 54) is sealed by the second sealing material 8b. ing. Here, the first sealing material 8a and the second sealing material 8b are integrally formed. That is, a part of the sealing material functions as the first sealing material 8a, and the other part functions as the second sealing material 8b.

Further, a getter material 9 a is provided in a space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5. In this embodiment, since there is no gap on the second substrate surface 11b side of the element substrate 11 in the housing 5, the getter material 9b described with reference to FIGS. 3 and 4 is not provided.

  In the housing 5, one end 56 in the longitudinal direction is formed with a notch 57 for drawing out one end 11 s of the element substrate 11. When sealing the notch 57, the space between the first substrate surface 11a of the element substrate 11 and the housing 5 is sealed with a first sealing material 8a. Also. A space between the second substrate surface 11b of the element substrate 11 and the translucent spacer 45 is sealed with an adhesive 9f.

  Even in such a form, in order for oxygen and moisture to reach the organic EL element 2, it is necessary to penetrate the sealing portion by the first sealing material 8a and the sealing portion by the second sealing material 8b. The effect similar to that of the first embodiment is obtained.

  Further, in this embodiment, the entire outer peripheral surface of the translucent spacer 45 is joined to the translucent member holding portion 53 (opening portion 54) with the second sealing material 8b. For this reason, since the sealing length in the 2nd sealing material 8b is long, there exists an advantage that oxygen and a water | moisture content do not reach the organic EL element 2. FIG.

[Modification of Embodiment 2]
6A and 6B are explanatory views of an exposure head (electro-optical device) according to a modification of the second embodiment of the present invention, and the exposure head 10 is shown by B1-B1 in FIG. 5B. It corresponds to a cross-sectional view when cut at a position corresponding to the line '. Since the basic configuration of this embodiment is the same as that of Embodiments 1 and 2, common portions are denoted by the same reference numerals and description thereof is omitted.

  The exposure head 10 shown in FIGS. 6A and 6B is of the type shown in FIG. 1B and includes a lens array 40 and a light-transmitting spacer 45 as the light-transmitting member 4. Therefore, in this embodiment, as described below, sealing between the translucent member 4 and the housing 5 is performed between the translucent spacer 45 and the housing 5. The translucent spacer 45 and the lens array 40 are joined by an adhesive 9e, and the translucent spacer 45 and the second substrate surface 11b of the element substrate 11 are joined by an adhesive 9f. The housing 5 is an integral one.

  In the exposure head 10 shown in FIGS. 6A and 6B, the housing 5 includes a cylindrical body 51 and an end plate portion 52 that closes one end of the cylindrical body 51. On the other end side, a translucent member holding portion 53 that holds the translucent member 4 with an opening 54 that emits light transmitted through the translucent member 4 is provided. In this embodiment, each of the translucent member holding portion 53 and the opening 54 is composed of an end portion on the other end side of the cylindrical body portion 51, and the translucent member 4 (translucent member) is placed in the opening 54 (the translucent member holding portion 53). The light spacer 45) is in a fitted state.

  In the exposure head 10 shown in FIG. 6A, only a part of the translucent spacer 45 is accommodated inside the housing 5, and the rest protrudes from the housing 5. Moreover, the step part 51a as shown in FIG.3 and FIG.5 is not formed in the housing 5. FIG. In configuring the exposure head 10 using such a housing 5, in this embodiment, the element substrate 11 is disposed with the first substrate surface 11 a on which the organic EL element 2 is formed facing the end plate portion 52. A space between the element substrate 11 and the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a. In addition, a portion between the outer peripheral surface of the translucent member 4 accommodated in the housing 5 on the outer peripheral surface of the translucent spacer 45 and the translucent member holding portion 53 (opening 54) is the second sealing material 8b. It is sealed by. Here, the first sealing material 8a and the second sealing material 8b are integrally formed. Further, a getter material 9 a is provided in a space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5. Even in such a form, in order for oxygen and moisture to reach the organic EL element 2, it is necessary to penetrate the sealing portion by the first sealing material 8a and the sealing portion by the second sealing material 8b. The effect similar to that of the first embodiment is obtained.

  In particular, in this embodiment, since the outer peripheral surface of the translucent spacer 45 is joined to the translucent member holding portion 53 (opening 54) by the second sealing material 8b, the sealing length of the second sealing material 8b is small. long. Therefore, there is an advantage that oxygen and moisture do not reach the organic EL element 2.

  In the exposure head 10 shown in FIG. 6B, the translucent spacer 45 is entirely accommodated inside the housing 5, and only the lens array 40 protrudes from the housing 5. Further, the housing 5 has a stepped portion 51a as shown in FIGS. In configuring the exposure head 10 using such a housing 5, in this embodiment, the element substrate 11 is disposed with the first substrate surface 11 a on which the organic EL element 2 is formed facing the end plate portion 52. A space between the element substrate 11 and the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a. Moreover, between the translucent member 4, the whole outer peripheral surface of the translucent spacer 45 and the translucent member holding part 53 (opening part 54) are sealed with the 2nd sealing material 8b. Here, a part 8ba of the second sealing material 8b protrudes to the outside of the housing 5, and completely blocks the space between the translucent spacer 45 and the translucent member holding portion 53 (opening portion 54). Further, a getter material 9 a is provided in a space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5. Even in such a form, in order for oxygen and moisture to reach the organic EL element 2, it is necessary to penetrate the sealing portion by the first sealing material 8a and the sealing portion by the second sealing material 8b. The effect similar to that of the first embodiment is obtained. Further, a part 8ba of the second sealing material 8b protrudes to the outside of the housing 5 and completely blocks between the light transmissive spacer 45 and the light transmissive member holding portion 53 (opening 54). Oxygen and moisture are difficult to enter.

[Embodiment 3]
FIG. 7 is an explanatory diagram of an exposure head (electro-optical device) according to Embodiment 3 of the present invention. When the exposure head 10 is cut at a position corresponding to the line B1-B1 ′ of FIG. It corresponds to a sectional view. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  The exposure head 10 shown in FIG. 7 is of the type shown in FIG. 1B and includes a lens array 40 and a light transmissive spacer 45 as the light transmissive member 4. Therefore, as described below, sealing between the translucent member 4 and the housing 5 is performed both between the lens array 40 and the housing 5 and between the translucent spacer 45 and the housing 5. It is. Here, the translucent spacer 45 and the lens array 40 are joined by an adhesive 9e, and the translucent spacer 45 and the second substrate surface 11b of the element substrate 11 are joined by an adhesive 9f. The housing 5 includes a housing main body 6 having one end open, and a lid member 7 that covers the open end of the housing main body 6.

  The housing 5 includes a cylindrical body 51 and an end plate part 52 that closes one end of the cylindrical body 51, and the light transmitted through the translucent member 4 is transmitted to the other end of the cylindrical body 51. An outgoing opening 54 is formed. Here, the translucent member holding portion 53 a for the translucent spacer 45 is formed by the other end itself of the cylindrical body portion 51, and the translucent member holding portion 53 b for the lens array 40 is an opening formed in the lid member 7. Part 54 is used. For this reason, the translucent spacer 45 is fitted to the other end (translucent member holding portion 53a) of the cylindrical body 51, and the lens array 40 is fitted to the opening 54 (translucent member holding portion 53b).

  In configuring the exposure head 10 using such a housing 5, in this embodiment, the element substrate 11 is disposed with the first substrate surface 11 a on which the organic EL element 2 is formed facing the end plate portion 52. A space between the element substrate 11 and the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a.

  Moreover, between the outer peripheral surface of the translucent spacer 45 and the other end (translucent member holding part 53a) of the cylindrical trunk | drum 51 among the translucent members 4, it seals with the 2nd sealing material 8b. Further, the space between the outer peripheral surface of the lens array 40 and the opening 54 (translucent member holding portion 53b) is also sealed with the second sealing material 8b. Here, the 1st sealing material 8a and the 2nd sealing material 8b between the outer peripheral surface of the translucent spacer 45, and the other end (translucent member holding | maintenance part 53a) of the cylindrical trunk | drum 51 are formed integrally. Has been. Further, the space between the housing body 6 and the lid member 7 is sealed with a third sealing material 8c.

  Furthermore, the space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5 and the light transmitting member 4 (lens array 40) and the housing 5 are defined on the second substrate surface 11 b side of the element substrate 11. In the space 5b, getter materials 9a and 9b are provided.

  Even in such a form, in order for oxygen and moisture to reach the organic EL element 2, it is necessary to penetrate the sealing portion by the first sealing material 8a and the sealing portion by the second sealing material 8b. The effect similar to that of the first embodiment is obtained.

  In particular, in this embodiment, the sealing portion by the second sealing material 8b is between the outer peripheral surface of the translucent spacer 45 and the other end (translucent member holding portion 53a) of the cylindrical body 51, and of the lens array 40. Since it exists between an outer peripheral surface and the opening part 54 (translucent member holding part 53b), the sealing length in the 2nd sealing material 8b is long. Therefore, there is an advantage that oxygen and moisture do not reach the organic EL element 2.

[Modification of Embodiment 3]
FIG. 8 is an explanatory diagram of an exposure head (electro-optical device) according to a modification of the third embodiment of the present invention, and the exposure head 10 is cut at a position corresponding to the line B1-B1 ′ in FIG. It corresponds to a cross-sectional view at that time. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  The exposure head 10 shown in FIG. 8 is of the type shown in FIG. 1B, and includes a lens array 40 and a light transmissive spacer 45 as the light transmissive member 4. Therefore, as described below, sealing between the translucent member 4 and the housing 5 is performed both between the lens array 40 and the housing 5 and between the translucent spacer 45 and the housing 5. It is. Here, the translucent spacer 45 and the lens array 40 are joined by an adhesive 9e, and the translucent spacer 45 and the second substrate surface 11b of the element substrate 11 are joined by an adhesive 9f. The housing 5 includes a housing main body 6 having one end open, and a lid member 7 that covers the open end of the housing main body 6.

  The housing 5 includes a cylindrical body 51 and an end plate part 52 that closes one end of the cylindrical body 51, and the light transmitted through the translucent member 4 is transmitted to the other end of the cylindrical body 51. An outgoing opening 54 is formed. Here, the translucent member holding portion 53 a for the translucent spacer 45 is formed by the other end itself of the cylindrical body portion 51, and the translucent member holding portion 53 b for the lens array 40 is an opening formed in the lid member 7. Part 54 is used. For this reason, the translucent spacer 45 is fitted to the other end (translucent member holding portion 53a) of the cylindrical body 51, and the lens array 40 is fitted to the opening 54 (translucent member holding portion 53b).

  In configuring the exposure head 10 using such a housing 5, in this embodiment, the element substrate 11 is disposed with the first substrate surface 11 a on which the organic EL element 2 is formed facing the end plate portion 52. A space between the element substrate 11 and the inner wall of the cylindrical body 51 is sealed with a first sealing material 8a.

  Moreover, between the outer peripheral surface of the translucent spacer 45 and the other end (translucent member holding part 53a) of the cylindrical trunk | drum 51 among the translucent members 4, it seals with the 2nd sealing material 8b. Here, the 1st sealing material 8a and the 2nd sealing material 8b between the outer peripheral surface of the translucent spacer 45, and the other end (translucent member holding | maintenance part 53a) of the cylindrical trunk | drum 51 are formed integrally. Has been.

  The space between the outer peripheral surface of the lens array 40 and the periphery of the opening 54 (translucent member holding portion 53b) of the lid member 7 is also sealed with the second sealing material 8b. Here, the second sealing material 8b between the outer peripheral surface of the lens array 40 and the opening 54 (translucent member holding portion 53b) is formed on the entire surface of the lid member 7 on the side where the element substrate 11 is located, and the housing. The space between the main body 6 and the lid member 7 is also sealed.

  Further, a getter material 9 a is provided in a space 5 a defined by the first substrate surface 11 a of the element substrate 11 and the housing 5. In this embodiment, since there is no gap on the second substrate surface 11b side of the element substrate 11 in the housing 5, the getter material 9b described with reference to FIG. 7 is not provided.

  Even in such a form, in order for oxygen and moisture to reach the organic EL element 2, it is necessary to penetrate the sealing portion by the first sealing material 8a and the sealing portion by the second sealing material 8b. The effect similar to that of the first embodiment is obtained.

  In particular, in this embodiment, the sealing portion by the second sealing material 8b is between the outer peripheral surface of the translucent spacer 45 and the other end (translucent member holding portion 53a) of the cylindrical body 51, and of the lens array 40. Since it exists between an outer peripheral surface and the opening part 54 (translucent member holding part 53b), the sealing length in the 2nd sealing material 8b is long. Therefore, there is an advantage that oxygen and moisture do not reach the organic EL element 2.

[Other embodiments]
In the above embodiment, a sealing film or a sealing substrate is not provided on the cathode layer 25 on the first substrate surface 11 a side of the element substrate 11, but silicon nitride is provided on the cathode layer 25. The present invention may be applied to the element substrate 11 on which a sealing film using a film or the like is laminated, or the exposure head 10 in which the sealing substrate is provided on the first substrate surface 11 a side of the element substrate 11. .

  In the above embodiment, the organic EL element 2 is used as the light emitting element. However, the present invention can be applied to the case where an inorganic EL element or LED (Light Emitting Diode) is used as the light emitting element.

  In the above-described embodiment, the electro-optical device is configured as the exposure head 10, but the image forming apparatus 100 is configured as long as the translucent member 4 is provided on the second substrate surface 11 b side of the element substrate 11. In addition to the exposure head 10, the present invention may be applied to an electronic device such as an illumination device using a light emitting element as a light source, or an electro-optical device used in an electronic device such as a mobile phone.

[Entire configuration of image forming apparatus]
The overall configuration of the image forming apparatus to which the present invention is applied will be described with reference to FIGS. FIG. 9 and FIG. 10 are a longitudinal sectional view showing an overall configuration of an image forming apparatus to which the present invention is applied, and a longitudinal sectional view showing an overall configuration of another image forming apparatus to which the present invention is applied.

(Configuration example 1 of image forming apparatus)
An image forming apparatus 100 shown in FIG. 9 is a tandem full-color image forming apparatus using a belt intermediate transfer body method. In this image forming apparatus 100, four exposure heads 10K, 10C, 10M, and 10Y are arranged at exposure positions of four photosensitive drums (image carriers) 110K, 110C, 110M, and 110Y, respectively. The exposure heads 10K, 10C, 10M, and 10Y are the exposure heads 10 according to the above embodiments.

  The image forming apparatus 100 includes a driving roller 121 and a driven roller 122, and an endless intermediate transfer belt 120 is wound around these rollers 121 and 122, and the rollers 121 and 122 are indicated by arrows. Can be rotated around. Although not shown, tension applying means such as a tension roller that applies tension to the intermediate transfer belt 120 may be provided.

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

  Around each photosensitive drum 110 (K, C, M, Y), a corona charger 111 (K, C, M, Y), an exposure head 10 (exposure heads 10K, C, M, Y), Developing units 114 (K, C, M, Y) are arranged. The corona charger 111 (K, C, M, Y) uniformly charges the outer peripheral surface of the corresponding photosensitive drum 110 (K, C, M, Y). The exposure head 10 (exposure heads 10K, C, M, Y) writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum. Each exposure head 10 (K, C, M, Y) is installed such that a plurality of organic EL elements 2 are arranged along the bus (main scanning direction) of the photosensitive drum 110 (K, C, M, Y). Is done. The electrostatic latent image is written by irradiating the photosensitive drum with light by a plurality of light emitting elements (organic EL elements 2). The developing device 114 (K, C, M, Y) forms a visible image, ie, a visible image, on the photosensitive drum by attaching toner as a developer to the electrostatic latent image.

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

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

  Since the image forming apparatus 100 uses a light emitting element (organic EL element) including a light emitting layer made of an organic EL material as writing means (exposure means), the apparatus is more suitable than a case where a laser scanning optical system is used. Can be miniaturized.

(Configuration example 2 of image forming apparatus)
An image forming apparatus 100 shown in FIG. 10 is a rotary developing type full-color image forming apparatus using a belt intermediate transfer body system, and a corona charger 168, a rotary type developing unit 161, and the like around a photosensitive drum 165. An exposure head 167 and an intermediate transfer belt 169 are provided.

  The corona charger 168 uniformly charges the outer peripheral surface of the photosensitive drum 165. The exposure head 167 writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum 165. The exposure head 167 is the exposure head 10 according to the above embodiment.

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

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

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

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

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

  Since the image forming apparatus 100 uses a light emitting element (organic EL element 2) including a light emitting layer made of an organic EL material as a writing unit (exposure unit), compared to a case where a laser scanning optical system is used. The size of the apparatus can be reduced.

(Other configuration examples)
Note that the light-emitting device of the present invention can also be adopted in an electrophotographic image forming apparatus other than those exemplified above. For example, the light emitting device according to the present invention is applied to an image forming apparatus that directly transfers a visible image from a photosensitive drum to a sheet without using an intermediate transfer belt, and an image forming apparatus that forms a monochrome image. Is possible.

2 .. Organic EL element (light emitting element) 4 .. Translucent member 5 .. Housing 6.. Housing body 7.. Lid material 8 a ... First seal material 8 b ... Second seal material 8c ··· Third sealing material 10 · · Exposure head (electro-optical device) 11 · · Element substrate 11a · · · First substrate surface 11b · · · Second substrate surface 40 · · Lens array (translucent Member), 45 .. translucent spacer, 53, 53a, 53b .. translucent member holding portion, 110 .. photosensitive drum, 110 s .. image bearing surface, 100.

Claims (12)

A translucent element substrate provided with a light emitting element on the first substrate surface, and a translucent member provided on the second substrate surface side opposite to the first substrate surface in the element substrate, An electro-optical device in which light emitted from the light emitting element is emitted through the element substrate and the translucent member,
An opening for emitting light that has passed through the translucent member on the other end side of the cylindrical body portion, comprising a cylindrical body portion surrounding the element substrate and an end plate portion that closes one end of the cylindrical body portion A housing provided with a translucent member holding part for holding the translucent member with a part;
A first sealing material that seals between the housing and the element substrate disposed with the first substrate surface facing the end plate inside the housing;
A second sealing material that seals between the translucent member and the housing;
An electro-optical device comprising:   The electro-optical device according to claim 1, wherein the light emitting element is an organic electroluminescence element. The translucent member is a lens array in which lenses that emit light emitted from the light emitting element as convergent light are integrally formed,
The electro-optical device according to claim 1, wherein the second sealing material seals between the lens array and the housing. The translucent member includes a lens array including a lens that emits the light emitted from the light emitting element as convergent light, and a translucent spacer interposed between the lens array and the element substrate.
The electro-optical device according to claim 1, wherein the second sealing material seals between the lens array and the housing. The translucent member includes a lens array having a lens that emits the light emitted from the light emitting element as convergent light, and a translucent spacer provided between the lens array and the element substrate. ,
3. The electro-optical device according to claim 1, wherein the second sealing material seals between the light-transmitting spacer and the housing. The translucent member includes a lens array having a lens that emits the light emitted from the light emitting element as convergent light, and a translucent spacer provided between the lens array and the element substrate. ,
3. The electro-optic according to claim 1, wherein the second sealing material seals between the translucent spacer and the housing and between the lens array and the housing. apparatus.   The electro-optical device according to claim 1, wherein the housing is integrally formed as a whole. The housing includes a housing body provided with the cylindrical body and the end plate, and a lid member connected to the other end of the cylindrical body with the opening.
The space between the other end of the cylindrical body and the lid member is sealed with a third sealing material or the second sealing material. Electro-optic device.   9. A getter material that captures at least one of oxygen and moisture is provided in a space defined by the first substrate surface of the element substrate and the housing. The electro-optical device according to any one of the above.   A getter material that captures at least one of oxygen and moisture is provided in a space defined by the translucent member and the housing on the second substrate surface side of the element substrate. The electro-optical device according to any one of claims 1 to 9.   An exposure head for an image forming apparatus, comprising the electro-optical device according to claim 1. An image forming apparatus comprising the electro-optical device according to any one of claims 1 to 10 as an exposure head,
An image forming apparatus comprising an image carrier on which a latent image is formed by light emitted from the light emitting element.

Images