JP2006196197A - Light emitting device, its manufacturing method, image forming device, and image reading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device capable of enhancing precision of position relationship between a light emitting element and a lens. <P>SOLUTION: The light emitting device 10 is provided with a substrate 11, a barrier 19 which is formed on the substrate 11 and demarcates a recess part on the substrate 11, the light emitting element 12 formed on the substrate 11 so that the position of a light emitting layer 16 will be regulated by the recess part, and the lens 20 overlapped on the light emitting element 12 and formed in the recess part. In manufacturing the light emitting device 10, the lens 20 can be formed by adding a material of the lens 20 into the recess part utilized to form a positive hole injection layer 15 and the light emitting layer 16 of the light emitting element 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a light-emitting device including a light-emitting element on a substrate, a manufacturing method thereof, an image forming apparatus, and an image reading apparatus.

In recent years, light-emitting devices including light-emitting elements such as EL elements (electroluminescence elements) on a substrate have been widely used as exposure devices for display devices and electrophotographic image forming apparatuses.

Some of such light emitting devices include a lens for converging or collimating light emitted from the light emitting element. For example, Patent Document 1 describes a configuration in which a lens is provided in a light emitting device in which an inorganic EL element as a light emitting element is formed on a substrate. For example, in the light emitting device described in FIG. 6 of Patent Document 1, a lens is provided on the surface of a cover glass that seals the light emitting element at a position overlapping the light emitting element. These lenses are formed integrally on the surface of the cover glass by an etching process, or are molded using a mold and then adhered to the surface of the cover glass.
JP 2004-58448 A

However, when the lens is provided on the surface of the cover glass as described in Patent Document 1, there is a possibility that the lens is displaced with respect to the light emitting element. When such a positional deviation occurs, the lens does not face the light emitting element, and the function of the lens cannot be sufficiently exhibited. In addition, since the light emitting element on the substrate is separated from the lens on the cover glass, the ratio of the light transmitted through the lens out of the light from the light emitting element is reduced, and the light use efficiency is lowered.

An object of the present invention is to provide a light emitting device, a method for manufacturing the same, an image forming apparatus, and an image reading apparatus that can improve the accuracy of the positional relationship between the light emitting element and the lens.

A light-emitting device according to the present invention includes a substrate, a partition wall formed on the substrate and defining a recess on the substrate, and a light-emitting layer whose position is regulated by the recess, and is formed on the substrate. And a lens formed in the recess so as to overlap the light emitting element. Thus, by forming a lens in the recess that regulates the position of the light emitting layer of the light emitting element,
The accuracy of the positional relationship between these light emitting elements and the lens can be increased, and the distance between them can be reduced. As a result, the light emitted from the light emitting element can be accurately and efficiently guided to the lens.
Here, “inside the recess” means that the lens is in the recess when viewed from the direction perpendicular to the substrate surface, and the lens may not protrude from the recess when the substrate is viewed from the side. May be.

In a preferred embodiment, a sealing body for sealing the light emitting element together with the lens in cooperation with the substrate is provided. By sealing the light emitting element and the lens in this manner, the lens can be protected while preventing the light emitting element from being deteriorated.

In another preferred embodiment, a thin film sealing layer is provided between the light emitting element and the lens and seals the light emitting element in cooperation with the substrate. In a light emitting device in which a light emitting layer is formed in a recess defined by a partition wall, even if the light emitting element is sealed with a thin film sealing layer, unevenness corresponding to the partition wall and the recess is generated in the sealing layer. Therefore, since the sealing layer also has a recess at a position overlapping with the recess, it is possible to form a lens in the recess that regulates the position of the light emitting layer.

The method of manufacturing a light emitting device according to the present invention includes a step of forming a partition wall on the substrate so as to define a recess on the substrate, and a position of the light emitting layer is regulated by the recess. A step of forming a light emitting element on the substrate, and a lens molding liquid is applied in the recess, and then the molding material is cured to form a lens at a position overlapping the light emitting element. And a process. In this way, by applying a liquid molding material in the recess that regulates the position of the light emitting layer of the light emitting element, and then curing it to form a lens, the accuracy of the positional relationship between the light emitting element and the lens is improved. Can be increased. In addition, since the lens material is provided in the recess used to form the light emitting element, it is not necessary to provide a special recess to provide the lens material.

In a preferred embodiment, droplets of the molding material are applied into the recess using a droplet discharge device that can discharge the molding material as droplets. As described above, the molding material can be applied without damaging the light emitting element by applying the droplet of the molding material into the recess for forming the light emitting element.

The image forming apparatus according to the present invention includes an image carrier, a charger for charging the image carrier, and a plurality of the light emitting elements, and a plurality of the light emitting elements on a charged surface of the image carrier. The light-emitting device that forms a latent image by irradiating light, a developing unit that forms a visible image on the image carrier by attaching toner to the latent image, and another visible image from the image carrier. A transfer machine for transferring to an object. Since the light-emitting device can accurately guide the light emitted from the light-emitting element to the lens, by using such a light-emitting device, a high-resolution latent image can be favorably formed on the image carrier and a high-quality image can be obtained. Can be formed.

The image reading apparatus according to the present invention includes the light emitting device in which a plurality of the light emitting elements are arranged;
A light receiving device that converts light emitted from the light emitting element and reflected by a reading target into an electrical signal. Since the light emitting device can accurately guide the light emitted from the light emitting element to the lens, by using such a light emitting device, it is possible to efficiently irradiate the reading target with light. In order to obtain illuminance, the voltage applied to the light emitting element can be reduced as compared with the conventional case.

Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings. In the drawings, the ratio of dimensions of each part is appropriately changed from the actual one.

<First Embodiment>
FIG. 1 is a cross-sectional view showing a light emitting device according to the first embodiment of the present invention, and FIG. 2 is a plan view of the electro-optical device. More specifically, FIG. 1 is a cross-sectional view taken along line AA in FIG.

The light-emitting device 10 illustrated in the figure includes a plurality of light-emitting elements 12 on a substrate 11, and for example, a latent image is formed on an image carrier (for example, a photosensitive drum) in an image forming apparatus using an electrophotographic system. Used as a line-type optical head for writing. Each light emitting element 12 is an organic light emitting diode (hereinafter abbreviated as “OLED”) element and emits light according to an applied voltage. The substrate 11 is made of a suitable material such as glass, plastic, ceramic, or metal, and may be transparent or opaque. A driving element layer 13 is formed on the substrate 11, and a plurality of light emitting elements 12 are formed thereon. Although detailed illustration of the inside of the drive element layer 13 is omitted, a plurality of TFT (thin film transistor) elements and wiring for supplying current to the TFT elements are provided here. Each TFT element applies a driving voltage to the light emitting element 12.

As shown in FIG. 2, the light emitting elements 12 are arranged in two rows and a staggered pattern. The arrangement pattern of the light emitting elements 12 is not limited to the illustrated form, and may be a single row or three or more rows, or may be arranged in another appropriate pattern.

Light emitted from each light emitting element 12 is emitted upward in FIG. 1 on the side opposite to the substrate 11. That is, the light emitting device 10 is a top emission type OLED light emitting panel. Each of the light emitting elements 12 includes an anode 14 formed on the drive element layer 13, a hole injection layer 15 formed on the anode 14, a light emitting layer 16 formed thereon, And a cathode 17 formed thereon. The cathode 17 is common to the plurality of light emitting elements 12.

In order to allow light emitted from the light emitting layer 16 to travel upward, the anode 14 is made of a conductive material that reflects light, such as aluminum, while the cathode 17 is made of transparent ITO (
Indium Tin Oxide). The hole injection layer 15 and the light emitting layer 16 are formed of the insulating layer 1
8 and the recess 19 defined by the partition wall 19. The recess is the hole injection layer 1
5 and the position of the light emitting layer 16, and thus the position of the light emitting element 12 is regulated. The hole injection layer 15 can be formed by applying the liquid molding material in the recess and then curing it. After the hole injection layer 15 is cured, the light emitting layer 16 can be similarly formed by applying the liquid molding material in the recess and then curing it. In the formation of the hole injection layer 15 and the light emitting layer 16, a droplet discharge device (typically an ejection device having the same principle as an ink jet printer) is used to supply a liquid material. The material of the insulating layer 18 is, for example, SiO ₂ , and the material of the partition wall 19 is, for example, polyimide or acrylic.

The configuration of each light-emitting element 12 in this embodiment is as described above, but as a variation of the light-emitting element that can be used in the present invention, a type in which an electron injection layer is provided between the cathode and the light-emitting layer, or an appropriate one can be used. It may be a type having other layers such as a type in which an insulating layer is provided at a position.

A cathode 17 is formed on the light emitting layer 16 and the partition wall 19, and a convex lens 20 is formed on the cathode 17 in a recess located above the light emitting layer 16. Since the light emitting element 12 in which the positions of the hole injection layer 15 and the light emitting layer 16 are regulated by the partition wall 19 as described above is formed below the concave portion where the lens 20 is formed, the lens is formed in the concave portion. By forming 20, the accuracy of the positional relationship between the lens 20 and the light emitting element 12 is inevitably increased. That is, the lens 20 can be formed with high accuracy at a position facing the light emitting element 12.

The lens 20 can be formed by applying a liquid as a molding material in the concave portion above the light emitting layer 16 and then curing it. As the liquid molding material, ultraviolet curable or thermosetting plastic can be used. Since the position of the liquid molding material is regulated in the recess, the positional relationship with the light emitting element 12 is determined with higher accuracy. The liquid molding material is desirably applied so as not to damage the light emitting element 12, and for this purpose, a droplet discharge device capable of discharging droplets can be used. The droplet discharge device may be, for example, an ejection device based on the same principle as an inkjet printer that ejects liquid ink using a piezoelectric element.

A transparent sealing body 22 is bonded onto the cathode 17 and the lens 20 with a transparent adhesive 21. As the adhesive 21, for example, a transparent epoxy ultraviolet curable plastic, a transparent acrylic ultraviolet curable plastic, or various transparent thermosetting plastics can be used. The sealing body 22 cooperates with the substrate 11 to seal the light emitting element 12 together with the lens 20, thereby separating the light emitting element 12 from the outside air (particularly moisture and oxygen) and suppressing deterioration thereof. The sealing body 22 can be formed of, for example, transparent glass or plastic. The lens 20 has a higher refractive index than the adhesive 21, and the refractive index of the adhesive 21 is equal to or higher than the refractive index of the sealing body 22. The relationship between these refractive indexes is not limited to this, and can be arbitrarily set according to the purpose of use of the light emitting device.

As a molding material for the lens 20 and the adhesive 21, various materials such as an ultraviolet curable epoxy adhesive having different refractive indexes can be used. As these molding materials, for example, Optodyne (trademark) UV-3200 manufactured by Daikin Industries, Ltd., which is an ultraviolet curable epoxy adhesive having a refractive index of 1.514, which is similar to that of glass, has a refractive index higher than that of glass. Optclave made by Adel Co., Ltd., which is an ultraviolet curable epoxy adhesive having a large refractive index of 1.63
(Trademark) HV153 and Optodyne (trademark) UV-4000 made by Daikin Industries, Ltd., which is an ultraviolet curable epoxy adhesive having a refractive index of 1.567.

The light emitting device 10 configured as described above can focus the light beam from the light emitting element 12 by the convex lens 20 and then emit it upward in FIG. Further, a converging lens array (not shown) is provided above the sealing body 22, and the converging lens array
The light from the lens 20 can be further focused and used. What is a converging lens array?
A lens array in which a plurality of gradient index lenses that can transmit light and form an erect image with respect to the original image are arranged, and the image formed by the plurality of gradient index lenses is one continuous image. It becomes. As the converging lens array, for example, there is SLA (Selfoc Lens Array) available from Nippon Sheet Glass Co., Ltd. (Selfoc \ SELFOC is a registered trademark of Nippon Sheet Glass Co., Ltd.). For example, when the light emitting device 10 is used as a line-type optical head in an electrophotographic image forming apparatus, the light focused by the lens 20 and the focusing lens array reaches an image carrier such as a photosensitive drum. An electrostatic latent image can be formed there. Note that the microlens is not necessarily provided depending on the light condensing performance of the lens 20 and other optical conditions.

Further, as described above, since the partitioning position 19 that restricts the positions of the hole injection layer 15 and the light emitting layer 16 of the light emitting element 12 is used to restrict the formation position of the lens 20, the lens 2.
0 is positioned with high accuracy with respect to the light emitting element 12. Therefore, the lens 20 faces the light emitting element 12 with high accuracy and sufficiently exhibits the lens function, and the light beam from the light emitting element 12 can be accurately focused to project a precise image.

In addition, since the distance between the lens 20 and the light emitting element 12 is extremely short, light from the light emitting element 12 tends to enter the lens 20. That is, the utilization efficiency of the light emitted from the light emitting element 12 can be significantly increased. Therefore, in order to obtain an image with the same illuminance, it is possible to reduce the voltage applied to the light emitting element as compared with the conventional case, and it is possible to extend the life of the light emitting element accordingly.

Next, a method for manufacturing the light emitting device 10 will be described.
First, the drive element layer 13, the anode 14, the insulating layer 18, and the partition wall 19 are formed on the substrate 11. Since these molding methods may be any known method, description thereof is omitted.

Thereafter, the material of the hole injection layer 15 is applied onto the anode 14 in the recess defined by the insulating layer 18 and the partition wall 19 by a droplet discharge device, and is cured. After the hole injection layer 15 is cured, on the hole injection layer 15 in the recess defined by the insulating layer 18 and the partition wall 19,
The material of the light emitting layer 16 is administered by a droplet discharge device and is cured. Further, a cathode 17 having a uniform thickness is deposited on the light emitting layer 16 and the partition wall 19 of the plurality of light emitting elements 14.

Thereafter, the lens 20 is formed in the concave portion above the light emitting element 12 by using the partition wall 19 that regulates the positions of the hole injection layer 15 and the light emitting layer 16 of the light emitting element 12. The lens 20 can be molded by applying a liquid as a molding material into the recess by a droplet discharge device and then curing the liquid. After forming the lens 20 in this way, the adhesive 2
1, the sealing body 22 is adhered to complete the light emitting device 10. According to this method, since the material of the lens 20 is applied in the recess used to form the hole injection layer 15 and the light emitting layer 16 of the light emitting element 14, a special recess is used to apply the material of the lens 20. There is no need to provide.

<Second Embodiment>
FIG. 3 is a cross-sectional view showing a light emitting device 1110 according to the second embodiment of the present invention. Second
In the embodiment, only the sealing structure of the light emitting element 12 is different from the light emitting device 10 of the first embodiment described above.

That is, in the second embodiment, a transparent sealing body 111 such as glass is formed on the substrate 11.
2 is bonded by an adhesive 1111, and the sealing body 1112 seals the lens 20 and the light emitting element 12 in cooperation with the substrate 11. More specifically, the cathode 17 formed on the substrate 11.
The sealing body 1112 is bonded to the top, and the light emitting element 12 is sealed together with the lens 20 in a sealing space formed between the sealing body 1112 and the substrate 11. In the sealing space, the light emitting element 1
A desiccant 1113 for absorbing moisture that may adversely affect 2 is provided. The adhesive 1111 may be transparent or not transparent.

<Third Embodiment>
FIG. 4 is a cross-sectional view showing a light-emitting device 1210 according to the third embodiment of the present invention.
In the third embodiment, a transparent thin film sealing layer 1 is formed on the cathode 17 and the lens 20.
211 is formed. The sealing layer 1211 is formed by, for example, CVD (chemical vapor deposition), and seals the light emitting element 12 together with the lens 20 in cooperation with the substrate 11. The sealing layer 1211 has a refractive index lower than that of the lens 20. According to the first to third embodiments, the sealing bodies 12, 1111, and 1211 can not only prevent the light emitting element 14 from being deteriorated, but also protect the lens 20.

<Fourth embodiment>
FIG. 5 is a sectional view showing a light emitting device 1310 according to the fourth embodiment of the present invention.
In the fourth embodiment, a transparent thin film sealing layer 1311 is formed on the cathode 17, and the sealing layer 1311 cooperates with the substrate 11 to seal the light emitting element 12. The sealing layer 1311 can be formed by, for example, CVD (chemical vapor deposition), and the cathode 1
7 is thinly formed on the surface. In such a thin sealing layer 1311, irregularities corresponding to the partition walls 19 and the concave portions are formed. Accordingly, since the sealing layer 1311 also has a recess at a position overlapping the recess defined by the partition wall 19, the lens is placed in the recess that regulates the positions of the hole injection layer 15 and the light emitting layer 16 of the light emitting element 12. 20 can be formed. The lens 20 is
The recess is formed in the same manner as in the above-described embodiment.

<Image forming apparatus>
As described above, the light emitting devices 10, 1110, 1210, and 1310 can be used as a line-type optical head for writing a latent image on an image carrier in an image forming apparatus using an electrophotographic system. Examples of the image forming apparatus include a printer, an image forming portion of a copying machine, and an image forming portion of a facsimile.

FIG. 6 is a longitudinal sectional view showing an example of an image forming apparatus using any one of the light emitting devices 10, 1110, 1210, and 1310 as a line type optical head. This image forming apparatus is a tandem type full color image forming apparatus using a belt intermediate transfer body system.

In this image forming apparatus, four organic EL array exposure heads 10K and 10C having the same configuration are used.
, 10M, 10Y are four photosensitive drums (image carriers) 110K, 11 having the same configuration.
Arranged at the exposure positions of 0C, 110M, and 110Y, respectively. The organic EL array exposure heads 10K, 10C, 10M, and 10Y are the light emitting devices 10, 1110, 1210, and 1 described above.
310.

As shown in FIG. 6, this image forming apparatus is provided with a driving roller 121 and a driven roller 122, and an endless intermediate transfer belt 120 is wound around these rollers 121 and 122, as indicated by arrows. Thus, the periphery of the rollers 121 and 122 is rotated. Although not shown,
A tension applying unit such as a tension roller that applies tension to the intermediate transfer belt 120 may be provided.

Around the intermediate transfer belt 120, photosensitive drums 110K, 110C, 110M, and 110Y having photosensitive layers on four outer peripheral surfaces are arranged at predetermined intervals. Subscript 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. Photosensitive drums 110K and 11
0C, 110M, and 110Y are rotationally driven in synchronization with the driving of the intermediate transfer belt 120.

Around each photosensitive drum 110 (K, C, M, Y), a corona charger 111 (K, C,
M, Y), organic EL array exposure head 10 (K, C, M, Y), and developing device 114 (K, Y).
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 organic EL array exposure head 10 (K, C, M, Y) writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum. Each organic EL array exposure head 10 (K, C, M, Y) includes a plurality of OLED elements 1.
4 are arranged so that the arrangement direction of 4 is along the bus (main scanning direction) of the photosensitive drum 110 (K, C, M, Y). The electrostatic latent image is written by irradiating the photosensitive drum with light from the plurality of OLED elements 14. The developing device 114 (K, C, M, Y) forms a visible image, that is, a visible image on the photosensitive drum by attaching toner as a developer to the electrostatic latent image.

Black, cyan, magenta, and black formed by such a four-color single color image forming station
The yellow visible images are sequentially primary-transferred onto the intermediate transfer belt 120 to be superimposed on the intermediate transfer belt 120, and as a result, a full-color visible image is obtained. Inside the intermediate transfer belt 120, four primary transfer corotrons (transfer units) 112 (K, C, M, Y) are provided.
Is arranged. The primary transfer corotron 112 (K, C, M, Y) is connected to the photosensitive drum 11.
0 (K, C, M, Y) are arranged in the vicinity of the photosensitive drum 110 (K, C,
The visible image is electrostatically attracted from (M, Y) to transfer the visible image to the intermediate transfer belt 120 passing between the photosensitive drum and the primary transfer corotron.

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

The image forming apparatus shown in FIG. 6 includes light emitting devices 10 and 1 each having an organic EL array as writing means.
Since any one of 110, 1210, and 1310 is used, the apparatus can be reduced in size as compared with the case where a laser scanning optical system is used. Further, as described above, the light emitting element 1 of the light emitting device.
2 and the lens 20 can be positioned with high accuracy and the light emitted from the light emitting element 12 can be focused with high accuracy, so that a high-resolution image can be formed satisfactorily.

Next, another embodiment of the image forming apparatus according to the present invention will be described.
FIG. 7 is a longitudinal sectional view of another image forming apparatus using any one of the light emitting devices 10, 1110, 1210, and 1310 as a line type optical head. This image forming apparatus is a rotary developing type full-color image forming apparatus using a belt intermediate transfer body system. In the image forming apparatus shown in FIG. 7, around a photosensitive drum (image carrier) 165, a corona charger 168, a rotary developing unit 161, an organic EL array exposure head 167, and an intermediate transfer belt 16 are provided.
9 is provided.

The corona charger 168 uniformly charges the outer peripheral surface of the photosensitive drum 165. The organic EL array exposure head 167 writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum 165. The organic EL array exposure head 167 includes the light emitting devices 10, 1110, and 1210 described above.
, 1310 and the light emitting elements (OLED elements) 12 are arranged so that the arrangement direction thereof is along the bus line (main scanning direction) of the photosensitive drum 165. The electrostatic latent image is written by irradiating the photosensitive drum with light by the plurality of light emitting elements 12 described above.

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

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

Specifically, in the first rotation of the photosensitive drum 165, an electrostatic latent image for a yellow (Y) image is written by the exposure head 167, and a developed image of the same color is formed by the developing unit 163Y.
Further, the image is transferred to the intermediate 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 9, the yellow, cyan, magenta, and black visible images are sequentially superimposed on the intermediate transfer belt 169. As a result, a full-color visible image is formed on the transfer belt 169. It is formed. When images are finally formed on both sides of a sheet as an object on which an image is to be formed, the same color images of the front and back surfaces are transferred to the intermediate transfer belt 169, and then the front and back surfaces are transferred to the intermediate transfer belt 169. A full-color visible image is obtained on the intermediate transfer belt 169 by transferring the visible image of the next color.

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

The sheet on which the image has been transferred as described above is conveyed to the fixing device 172 and is passed between the heating roller 172a and the pressure roller 172b of the fixing device 172, whereby the visible image on the sheet is fixed. The sheet after the fixing process is drawn into the discharge roller pair 176 and proceeds in the direction of arrow F. In the case of double-sided recording, 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 as shown by the arrow G, the double-sided recording conveyance path 1
75. Then, the visible image is transferred to the other surface of the sheet by the secondary transfer roller 171, the fixing process is performed again by the fixing device 172, and then the sheet is discharged by the discharge roller pair 176.

The image forming apparatus of FIG. 7 includes an exposure head 167 having an organic EL array as writing means.
Since (any one of the light emitting devices 10, 1110, 1210, and 1310) is used, the size of the device can be reduced as compared with the case where the laser scanning optical system is used. As mentioned above,
Since the light emitting element 12 and the lens 20 of the light emitting device can be positioned with high precision and the light emitted from the light emitting element 12 can be accurately focused, a high resolution image can be formed satisfactorily.

As described above, the image forming apparatus to which any one of the light emitting devices 10, 1110, 1210, and 1310 can be applied is exemplified. However, the light emitting devices 10, 1110, and 12 can be applied to other electrophotographic image forming apparatuses.
10 and 1310 can be applied, and such an image forming apparatus is within the scope of the present invention. For example, the light emitting devices 10, 1110, 1210, and 1310 may be used in image forming apparatuses that transfer a visible image directly from a photosensitive drum to a sheet without using an intermediate transfer belt, and image forming apparatuses that form monochrome images. Either can be applied.

<Image reading device>
In addition, the light emitting devices 10, 1110, 1210, and 1310 can be used as a line type optical head for irradiating light to a reading target in the image reading device. Examples of the image reading apparatus include a scanner, a reading portion of a copying machine, a reading portion of a facsimile, a barcode reader, and a two-dimensional image code reader that reads a two-dimensional image code such as a QR code (registered trademark).

FIG. 8 is a longitudinal sectional view showing an example of an image reading apparatus using any one of the light emitting devices 10, 1110, 1210, and 1310 as a line type optical head. A flat platen glass 202 is provided on the upper part of the cabinet 201 of the image reading apparatus, and a document 203 is placed on the platen glass 202 with its image surface facing downward. A platen cover (not shown) presses the document 203 toward the platen glass 202.

Inside the cabinet 201, a high speed carriage 204 and a low speed carriage 205 are arranged so as to be movable in the horizontal direction. The high-speed carriage 204 irradiates the original 203 with the organic E
L array exposure head 206 (light emitting device 10, 1110, 1210, or 1310)
And the reflecting mirror 207 are mounted on the low-speed carriage 205.
9 is installed. These organic EL array exposure head 206 and reflecting mirrors 207, 2
08 and 209 extend in the direction perpendicular to the paper surface (main scanning direction) in FIG. The organic EL array exposure head 206 is installed so that the arrangement direction of the plurality of light emitting elements (OLED elements) 12 is along the main scanning direction.

A document reader 210 is disposed at a fixed position inside the cabinet 201. The document reader 210 includes an imaging lens 212 and a line sensor (light receiving device) 213 composed of a large number of photosensitive pixels (charge coupled devices). The line sensor 213 extends in the direction perpendicular to the paper surface (main scanning direction) in FIG. 20, and is installed so that the arrangement direction of the plurality of photosensitive pixels is along the main scanning direction.

Light emitted from the organic EL array exposure head 206 (any one of the light emitting devices 10, 1110, 1210, and 1310) is transmitted through the platen glass 202 and reflected by the lower surface of the document 203. Reflected light from the original 203 is transmitted through the platen glass 202, reflected by the reflecting mirrors 207 to 209, and then imaged by the line sensor 213 by the imaging lens 212. High speed carriage 2
04 moves laterally so that the entire surface of the original 203 is irradiated by the organic EL array exposure head 206, and the low speed carriage 205 moves at half the speed of the high speed carriage 204,
The length of the reflected light path from the original 203 to the line sensor 213 is kept constant.

As described above, the image reading device to which any one of the light emitting devices 10, 1110, 1210, and 1310 can be applied is exemplified.
Any of 310 can be applied, and such an image reading apparatus is within the scope of the present invention. For example, the light receiving device is a light emitting device 10, 1110, 1210 as an illumination device.
, 1310, or the light receiving device and the light emitting device 10, 1110, 1
Either 210 or 1310 may be fixed together, and the document or the reading target may be moved and read.

<Other applications>
The light emitting device according to the present invention can be further applied to various exposure apparatuses, illumination apparatuses, and image display apparatuses.

In the above light emitting device, an OLED element is used as a light emitting element for converting applied electric energy into optical energy. However, other light emitting elements (for example, an inorganic EL element and a plasma display element) emit light. It may be used for panels. Further, the lens does not need to be formed so as to be accommodated in the inner space of the recess defined by the partition wall, and the upper portion thereof may protrude above the recess as in the embodiment described above. That is, it is sufficient that the lens is at least partly located in the recess and its formation position is restricted.

It is sectional drawing which shows the light-emitting device which concerns on the 1st Embodiment of this invention. It is a top view of the light-emitting device of FIG. It is sectional drawing which shows the light-emitting device which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the light-emitting device which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows the light-emitting device which concerns on the 4th Embodiment of this invention. It is a longitudinal cross-sectional view which shows an example of the image forming apparatus using the light-emitting device in any one of the 1st to 4th embodiment of this invention. It is a longitudinal cross-sectional view which shows the other example of the image forming apparatus using the light-emitting device in any one of the 1st to 4th embodiment of this invention. It is a longitudinal cross-sectional view which shows an example of the image reading apparatus using the light-emitting device in any one of the 1st to 4th embodiment of this invention.

Explanation of symbols

10, 1110, 1210, 1310 ... light emitting device, 11 ... substrate, 12 ... light emitting element, 13
DESCRIPTION OF SYMBOLS ... Drive element layer, 14 ... Anode, 15 ... Hole injection layer, 16 ... Light emitting layer, 17 ... Cathode, 18 ... Insulating layer, 19 ... Partition, 20 ... Lens, 21 ... Adhesive, 22, 1112 ... Sealing body 1111: adhesive, 1113 ... desiccant, 1211, 1311 ... sealing layer, 10K, 10C, 10M, 10
Y, 167, 206... Organic EL array exposure head (light emitting device).

Claims (7)

A substrate,
A partition formed on the substrate and defining a recess on the substrate;
A light emitting element having a light emitting layer whose position is regulated by the recess and formed on the substrate;
A lens overlapping the light emitting element and formed in the recess;
A light emitting device comprising: The light emitting device according to claim 1, further comprising a sealing body that cooperates with the substrate to seal the light emitting element together with the lens. 2. The light emitting device according to claim 1, further comprising a thin film sealing layer interposed between the light emitting element and the lens and sealing the light emitting element in cooperation with the substrate. Forming a partition on the substrate so as to define a recess on the substrate;
Forming a light emitting element having the light emitting layer on the substrate in such a manner that the position of the light emitting layer is regulated by the recess.
A step of forming a lens at a position overlapping the light emitting element by applying a liquid molding material for lens molding in the recess and then curing the molding material;
A method for manufacturing a light-emitting device, comprising: The method for manufacturing a light-emitting device according to claim 4, wherein droplets of the molding material are applied into the recess using a droplet discharge device capable of discharging the molding material as droplets. An image carrier;
A charger for charging the image carrier;
The light emitting device according to any one of claims 1 to 5, wherein a plurality of the light emitting elements are arranged and a latent image is formed by irradiating light on the charged surface of the image carrier with the plurality of light emitting elements.
A developer that forms a visible image on the image carrier by attaching toner to the latent image;
A transfer machine for transferring the visible image from the image carrier to another object;
An image forming apparatus comprising: The light emitting device according to any one of claims 1 to 5, wherein a plurality of the light emitting elements are arranged,
A light receiving device that converts light emitted from the light emitting element and reflected by a reading object into an electrical signal;
An image reading apparatus comprising:

Images