JP4552665B2 - LIGHT EMITTING DEVICE, MANUFACTURING METHOD THEREOF, IMAGE FORMING DEVICE, AND IMAGE READING DEVICE - Google Patents

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 transparent cover glass is bonded onto the light-emitting element by a transparent adhesive such as resin, and the light-emitting element is positioned on the surface of the cover glass so as to overlap the light-emitting element. A lens is provided. The adhesive is cured into a shape covering the light emitting element, and bonds the cover glass onto the light emitting element. Therefore, the adhesive and the cover glass cooperate with the substrate to seal the light emitting element. The lens provided on the surface of the cover glass is integrally formed on the surface of the cover glass by an etching process, or is molded using a mold and then adhered onto the surface of the cover glass.

JP 2004-58448 A

However, as described in Patent Document 1, in the case where a lens is provided on the surface of a cover glass that is bonded onto the light emitting element, 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 easily and reliably include a lens at a position where the light beam focusing efficiency is good.

A light emitting device according to the present invention includes a substrate, a light emitting element formed on the substrate, and a transparent sealing film that is molded on the light emitting element and seals the light emitting element in cooperation with the substrate. And a lens formed integrally with the sealing film and overlapping the light emitting element.

As described above, by integrally molding the lens on the transparent sealing film formed on the light emitting element, a part of the sealing film in the immediate vicinity of the light emitting element functions as a lens. The distance between can be reduced. Further, the accuracy of the positional relationship between the light emitting element and the lens can be increased by integrally molding the lens on the sealing film directly bonded onto the light emitting element. As a result, the light emitted from the light emitting element can be accurately and efficiently guided to the lens. In addition, since the lens is integrally formed with the sealing film, the number of parts of the light emitting device can be reduced.

In a preferred embodiment, a transparent sealing substrate bonded to the sealing film is provided, and the lens is embedded in the sealing substrate. Thus, by providing a sealing substrate of a type that further surrounds the lens on the sealing film, the lens molded into the sealing film can be protected, and the light emitting element is formed by the sealing film and the sealing substrate. Can be double sealed. In addition, if an external force is applied to the thin sealing film, there is a risk of damage to the light emitting element overlapped with the thin sealing film and a conducting wire that energizes this, and a short circuit of the circuit for driving the light emitting element. According to this preferable form in which the substrates are overlapped, even if an external force is applied to the sealing substrate, the pressure applied to the light emitting element, the conductor and the circuit is reduced, and the risk of damage to these elements can be reduced.

The method for manufacturing a light emitting device of the present invention includes a step of forming a light emitting element on a substrate, and a step of forming a transparent sealing film including a lens shape portion on the light emitting element using a mold. ,including. Thus, by integrally molding the sealing film and the lens using the mold, they can be simultaneously molded on the light emitting element, and the manufacturing process of the light emitting device can be simplified.

In a preferred embodiment, a transparent mold is used as the mold, and the transparent mold is left without being removed after the molding of the sealing film. By leaving the transparent mold in this way, the mold can function as a sealing substrate. When an external force is applied to the thin sealing film, there is a risk of damage to the light emitting element overlapped with the thin sealing film and a conducting wire passing through the thin sealing film, and a short circuit of a circuit for driving the light emitting element. According to this preferred form of overlapping, even when an external force is applied to the sealing substrate, the pressure applied to the light emitting element, the conducting wire, and the circuit is reduced, and the risk of damage to these elements can be reduced.

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 transparent sealing film 20 is formed on the cathode 17. The sealing film 20 is molded using a mold as will be described later, and a convex lens 20A located above the light emitting layer 16 is integrally molded in a part thereof. As a molding material for the sealing film 20, for example, a transparent epoxy ultraviolet curable plastic, a transparent acrylic ultraviolet curable plastic, or various transparent thermosetting plastics can be used. The sealing film 20 is formed so as to cover the light emitting element 12 and is bonded to the substrate 12, thereby sealing the light emitting element 12 in cooperation with the substrate 11, and
In particular, it is separated from moisture and oxygen) to suppress its deterioration.

The light emitting device 10 configured as described above has a light beam emitted from the light emitting element 12 and a convex lens 20A.
And then discharged upward in FIG. Further, a converging lens array (not shown) is provided above the sealing film 20, and the light from the lens 20 </ b> A can be further converged and used by the converging lens array. A converging lens array is 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 are imaged by a plurality of gradient index lenses. The image becomes one continuous image. As a converging lens array, for example, SLA 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 20A 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 20A and other optical conditions.

Since the lens 20A is integrally formed with the thin sealing film 20 that is directly bonded onto the light emitting element 12, the lens 20A itself is directly bonded onto the light emitting element 12 without using a special adhesive or the like. It will be. Therefore, the distance between the lens 20A and the light emitting element 12 becomes extremely short,
Light from the light emitting element 12 tends to enter the lens 20A. 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, the voltage applied to the light emitting element 12 can be reduced as compared with the conventional case, and the life of the light emitting element 12 can be extended accordingly.

Further, since the light beam from the light emitting element 12 directly enters the lens 20A without using a special adhesive or the like, the lens 20A can accurately focus the light beam from the light emitting element 12 and project a precise image. it can. Further, the lens 20 </ b> A is integrally formed with the sealing film 20 itself that is directly bonded onto the light emitting element 12, so that the lens 20 </ b> A is positioned with high accuracy relative to the light emitting element 12. Therefore, the lens 20A can fully exhibit the lens function by facing the light emitting element 12 with high accuracy.

The sealing film 20 is also an adhesive that is directly bonded to the light emitting element 12. Therefore, the sealing film 20 has a function as a sealing member that separates the light emitting element 12 from the outside air, a function as an adhesive that bonds such a sealing member to the light emitting element 12, and a function as a lens. become. Further, since the lens 20A is integrally formed on the sealing film 20 as a sealing member indispensable for sealing the light emitting element 12, the number of parts of the light emitting device 10 can be reduced.

Moreover, as a variation of such a light emitting device 10, although not shown, a transparent sealing body such as glass is adhered on the substrate 11 with an adhesive, and the sealing body cooperates with the substrate 11,
The sealing film 20 including the lens 20A may be further sealed. More specifically,
A sealing body is bonded onto the sealing film 20 formed on the substrate 11, and a light emitting element is formed together with the sealing film 20 including the lens 20 </ b> A in a sealing space formed between the sealing body and the substrate 11. 12 is sealed. The sealing space may be provided with a desiccant for absorbing moisture that may adversely affect the light emitting element 12. That is, cap sealing may be performed. Moreover, the adhesive for adhering the sealing body on the substrate 11 may be transparent or not transparent.

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 layers 16 and the barrier ribs 19 of the plurality of light emitting elements 12. Hereinafter, the substrate 11 on which the sealing film 20 is not yet formed even if the light emitting element 12 is formed in this way is referred to as “light emitting device main body 10-1”.

FIGS. 3A to 3E are explanatory diagrams of a method for creating the mold 21 for molding the sealing film 20. However, the mold 21 may be molded by another mold without adopting the steps shown in FIGS. The material of the mold 21 includes glass or plastic. In any case, the mold 21 can be molded by another mold. However, when the plastic is used as the material of the mold 21, the mold 21 is different. It is preferable that the mold 21 shown in FIG. The plastic may be transparent or opaque. However, when the mold 21 is left without being removed after the molding of the sealing film 20 as in the second embodiment described later, it is necessary to be a transparent plastic.

Whether glass or plastic is used as the material of the mold 21, FIG.
) To (d) can be employed. In particular, when glass is used as the material of the mold 21, the steps shown in FIGS. 3 (a) to 3 (d) are performed. The mold 21 is preferably created. The glass may be transparent or opaque. However, when the mold 21 is left without being removed after the molding of the sealing film 20 as in the second embodiment described later, it is necessary to be transparent glass.

First, as shown in FIG. 3A, a plate glass for a mold 21 is prepared, and a resist film 22 serving as a mask for glass etching is formed on one surface thereof. Next, as shown in FIG. 3B, the resist film 22 is patterned to form openings 22A. The opening 22 </ b> A is a small-diameter hole that penetrates the resist film 22. In order to form the opening 22A, for example, a region where the opening 22A is to be formed in the resist film 22 may be exposed, and the region may be dissolved and removed with a developer.

Next, the plate glass for the mold 21 is etched with an etching solution (for example, hydrofluoric acid) to form a recess 21A in the plate glass as shown in FIG. In the etching, an etching solution is gradually introduced into the plate glass through the opening 22 </ b> A of the resist film 22. As a result, the portion of the plate glass around the opening 22A is gradually dissolved to form a hemispherical recess 21A centering on the opening 22A. Thereafter, after the resist film 22 is peeled off as shown in FIG. 3D, the surface of the mold 21 on the concave portion 21A side is shaved to reduce the thickness of the mold 21 as shown in FIG. The mold 21 may be cut by mechanical grinding and polishing, or may be chemically cut, for example, etching in a state where the recess 21A is masked.

Using the mold 21 created in this way, on the light emitting device main body 10-1, from FIG.
The sealing film 20 is formed through the step d).
First, as shown in FIG. 4A, the mold 21 with the concave portion 21 </ b> A facing upward is set in the holder 30. Next, as shown in FIG. 4B, the molding material for the sealing film 20 is poured into the holder 30.
The holder 30 prevents the molding material of the sealing film 20 from leaking from the side of the mold 21, and the concave material 21 </ b> A is completely filled with the molding material of the sealing film 20. The molding material of the sealing film 20 is a transparent material having a predetermined refractive index when cured. Like the second embodiment described later,
When the transparent mold 21 is left without being removed after the molding of the sealing film 20, a transparent material having a higher refractive index than that of the transparent mold 21 when cured is used as a molding material for the sealing film 20. .

As the molding material of the sealing film 20, transparent ultraviolet curable or thermosetting plastics can be used, and various materials such as ultraviolet curable epoxy adhesives having different refractive indexes can also be used. Specifically, 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.
, An ultraviolet curable epoxy adhesive having a refractive index of 1.63 which is higher than that of glass (
Optclave (trademark) HV153 manufactured by Adel Co., Ltd., and Optodyne (trademark) UV-40 manufactured by Daikin Industries, Ltd., which is an ultraviolet curable epoxy adhesive having a refractive index of 1.567
00.

Next, as shown in FIG. 4C, the light emitting device main body 10-1 with the light emitting element 12 facing downward is positioned in the holder 30, and the sealing film 20 between the mold 21 and the light emitting device main body 10-1 is positioned. The material is compressed to a predetermined size and shape. The molding material of the sealing film 20 is the mold 21 and the light emitting device main body 10-.
1 is in close contact with the opposite surface. Thereafter, the molding material of the sealing film 20 is cured to complete the molding of the sealing film 20, and then the holder 30 and the mold 21 are removed as shown in FIG. Thereby, the light emitting device 10 is completed. In addition, it is preferable that at least the process of pouring the molding material of the sealing film 20 (FIG. 4B) to the process of curing the molding material (FIG. 4C) is performed in a vacuum. By performing the work in a vacuum, the risk of bubbles occurring in the molding material of the sealing film 20 can be reduced. Even if bubbles are generated, the bubbles are compressed and become minute under atmospheric pressure after production.

As a variation of the method for manufacturing the light emitting device 10, although not shown, a mold 21 is used.
Of the sealing film between the light emitting device main body 10-1 with the light emitting element 12 facing upward and the mold 21 with the concave portion 21A facing down. A molding space may be formed.

<Second Embodiment>
FIG. 5 is a cross-sectional view showing a light emitting device 10 according to the second embodiment of the present invention. The second embodiment is different from the light emitting device 10 of the first embodiment described above only in that the transparent mold 21 is left without being removed.

That is, in the second embodiment, the mold 21 is left as a part of the components of the light emitting device 10 without removing the mold 21 after the molding of the sealing film 20. The remaining mold 21 functions as a sealing substrate bonded to the light emitting element 12 by the sealing film 20, and the light emitting element 1 formed on the substrate 11.
2 can be more reliably protected from deterioration. Further, the lens 20A of the sealing film 20 is embedded in the sealing substrate. In this way, by providing a sealing substrate of a type surrounding the lens 20A on the sealing film 20, the lens 20A molded on the sealing film 20 can be protected. In addition, when an external force is applied to the thin sealing film 20, there is a risk of damage to the light emitting element 12 and the conductive wire that passes through the thin sealing film 20, and a short circuit of the circuit for driving the light emitting element 12. According to this preferable form in which a mold 21 as a sealing substrate overlaps with 20,
Even when an external force is applied to the mold 21 as the sealing substrate, the pressure applied to the light emitting element 14, the conducting wire and the circuit is reduced, and the risk of damage to these elements can be reduced. The mold 21 left in this way has a lower refractive index than the lens 20A as described above.

<Image forming apparatus>
As described above, the light-emitting device 10 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 of the light emitting devices 10 of the first and second embodiments described above 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 1 of the first and second embodiments described above.
0.

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.

Since the image forming apparatus of FIG. 6 uses any one of the light emitting devices 10 of the first and second embodiments having an organic EL array as writing means, the apparatus is more than the case where a laser scanning optical system is used. Can be miniaturized. Further, as described above, since the light emitting element 12 and the lens 20A of the light emitting device can be positioned with high accuracy and the light emitted from the light emitting element 12 can be focused with high accuracy, a high resolution image can be formed satisfactorily. it can.

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 of the first and second embodiments 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, a corona charger 168, a rotary developing unit 161, an organic EL array exposure head 167, and an intermediate transfer belt 169 are provided around a photosensitive drum (image carrier) 165. Yes.

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 is one of the light-emitting devices 10 of the first and second embodiments described above, and the arrangement direction of the plurality of light-emitting elements (OLED elements) 12 is the bus (mainly) of the photosensitive drum 165. It is installed along the scanning direction. 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 (one of the light emitting devices 10 of the first and second embodiments) is used, the device can be made smaller than when a laser scanning optical system is used. Further, as described above, since the light emitting element 12 and the lens 20A of the light emitting device can be positioned with high accuracy and the light emitted from the light emitting element 12 can be focused with high accuracy, a high resolution image can be formed satisfactorily. it can.

As described above, the image forming apparatus to which any one of the light emitting devices 10 of the first and second embodiments can be applied has been exemplified. However, the first and second embodiments are also applied to other electrophotographic image forming apparatuses. Light emitting device 1
0 can be applied, and such an image forming apparatus is within the scope of the present invention. For example, the first and second embodiments can be 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. Any one of the light emitting devices 10 can be applied.

<Image reading device>
Further, the light emitting device 10 of the first and second embodiments 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 of the first and second embodiments 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
An L array exposure head 206 (one of the light emitting devices 10 of the first and second embodiments) and a reflecting mirror 207 are mounted, and two reflecting mirrors 208 and 209 are mounted on the low-speed carriage 205. . These organic EL array exposure head 206 and reflecting mirrors 207, 208,
Reference numeral 209 extends 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. 8, and is arranged 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 (one of the light emitting devices 10 of the first and second embodiments) 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. The high-speed carriage 204 moves in the horizontal direction so that the entire surface of the original 203 is irradiated by the organic EL array exposure head 206, and the low-speed carriage 205 moves at half the speed of the high-speed carriage 204,
The length of the reflected light path from 03 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 of the first and second embodiments can be applied has been exemplified. However, the light emitting devices 10 of the first and second embodiments can be applied to other image reading devices. Any of the above can be applied, and such an image reading apparatus is within the scope of the present invention. For example, the light receiving device may move together with one of the light emitting devices 10 of the first and second embodiments as an illumination device, or the light receiving device and the light emitting devices 10 of the first and second embodiments. Either of them may be fixed together, and the original 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.

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 explanatory drawing of the production | generation process of the type | mold used for the light-emitting device of FIG. It is explanatory drawing of the manufacturing process 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 a longitudinal cross-sectional view which shows an example of the image forming apparatus using the light-emitting device of the 1st or 2nd 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 of the 1st or 2nd 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 of the 1st or 4th embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Light-emitting device, 11 ... Board | substrate, 12 ... Light emitting element, 13 ... Drive element layer, 14 ... Anode, 15
DESCRIPTION OF SYMBOLS ... Hole injection layer, 16 ... Light emitting layer, 17 ... Cathode, 18 ... Insulating layer, 19 ... Partition, 20 ... Sealing film,
20A ... lens, 21 ... mold (sealing substrate), 22 ... resist film, 10K, 10C, 10M,
10Y, 167, 206... Organic EL array exposure head (light emitting device).

Claims (5)

A substrate,
A light emitting device formed on the substrate;
A transparent sealing film which is molded on the light emitting element and seals the light emitting element in cooperation with the substrate;
A lens integrally formed with the sealing film and overlapping the light emitting element;
A light emitting device comprising a transparent sealing substrate bonded to the sealing film, wherein the lens is embedded in the sealing substrate . Forming a light emitting element on the substrate;
A step of forming a transparent sealing film having a shape including a lens shape portion on the light emitting element using a mold,
Only including,
Using a transparent mold as the mold,
The method for manufacturing a light emitting device according to claim 1, wherein the transparent mold is left as the sealing substrate without being removed after the sealing film is formed .   By etching the material through the opening in a state where a mask having an opening is overlaid on the mold material, a mold having a hemispherical recess is formed, and the surface on the recess side of the mold is scraped. The manufacturing method according to claim 2, further comprising the step of preparing the mold having a recess corresponding to the shape portion of the mold. An image carrier;
A charger for charging the image carrier;
The light emitting device according to claim 1 , 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 developing unit that forms a visible image on the image carrier by attaching toner to the latent image; and
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 claim 1 , 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