JP4373581B2 - Exposure equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus, and more particularly to an exposure apparatus that exposes a photoreceptor using an organic electroluminescent element (hereinafter referred to as “organic EL element”).
[0002]
[Prior art and problems to be solved by the invention]
An organic EL element emits light when a voltage is applied to an organic light emitting material of a phosphor, and an exposure apparatus has been proposed that exposes a photoreceptor using light emitted from the organic EL element. For example, an exposure apparatus has been proposed that includes an organic EL element array light source in which organic EL elements are arranged in a one-dimensional array, and exposes light emitted from the light source to a photoconductor.
[0003]
However, in such an exposure apparatus, since the organic EL element array light source becomes large, the SELFOC lens array (hereinafter referred to as “SLA”) for imaging the light also becomes large, and the entire apparatus becomes large. There is a problem of becoming large.
[0004]
Conventionally, the wiring pattern routing is complicated when the organic EL element is driven at a high duty (≈100%), and it is conceivable to reduce the size in accordance with the simplification of the wiring pattern. Furthermore, it is necessary to improve the utilization efficiency of light emitted from the organic EL element more than ever.
[0005]
The present invention has been proposed in order to solve the above-described problems, and provides an exposure apparatus capable of reducing the size of the entire apparatus and efficiently using light emitted from an organic EL element. With the goal.
[0007]
[Means for Solving the Problems]
The invention described in claim 1 is a light-transmitting substrate which is formed in a rectangular parallelepiped shape, and has two reflecting surfaces which are separated from each other and reflect light incident from two opposing element forming surfaces in the light emitting surface direction. And first and second organic electroluminescent elements that are provided on the two element forming surfaces and emit different colors, respectively, and a side surface of the light-transmitting substrate that is different from the two element forming surfaces. And emitting light of a color different from that of the first and second organic electroluminescent elements in the direction of the light emitting surface, and passing the light between the two reflecting surfaces to emit from the light emitting surface . And an organic electroluminescent element, and exposing the photosensitive member with light emitted from a light emitting surface of the light transmissive substrate.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
[0016]
As shown in FIG. 1, an exposure apparatus 1 according to this embodiment includes an organic electroluminescent element (hereinafter referred to as “organic EL element”) array light source 10 (10R, 10) that emits red, green, and blue light, respectively. 10G, 10B) and a SELFOC lens array (hereinafter referred to as “SLA”) 30 for condensing the light from the organic EL element array light source 10 on the photosensitive member 40. The organic EL element array light sources 10R, 10G, and 10B emit red, green, and blue, respectively, and include organic EL elements 11R, 11G, and 11B, which will be described later. The organic EL element array light source 10 is comprised from the board | substrate 20 with which the organic EL element 11 was formed, as shown in FIG.
[0017]
(Configuration of organic EL element 11)
As shown in FIG. 3, an organic EL element 11 is formed on a substrate 20 by sequentially laminating a transparent electrode 12 as an anode, an organic compound layer 13 including a light emitting layer, and a metal electrode 14 as a cathode. The organic EL element 11 is covered with a sealing member 16 such as a stainless steel can. The edge of the sealing member 16 and the substrate 20 are bonded by the adhesive layer 17, and the organic EL element 11 is sealed in the sealing member 16 replaced with dry nitrogen gas. When a predetermined voltage is applied between the transparent electrode 12 and the metal electrode 14 of the organic EL element 11, the light emitting layer included in the organic compound layer 13 emits light, and the emitted light passes through the transparent electrode 12 and the substrate 20. It is taken out.
[0018]
The transparent electrode 12 serving as the anode preferably has a light transmittance of at least 50 percent or more, preferably 70 percent or more in the visible light wavelength region of 400 nm to 700 nm. As a material for constituting the transparent electrode 12, in addition to a compound known as a transparent electrode material such as tin oxide, indium tin oxide (ITO) and indium zinc oxide, a thin film made of a metal having a high work function such as gold or platinum is used. It may be used. Moreover, organic compounds, such as polyaniline, polythiophene, polypyrrole, or these derivatives, may be sufficient. The transparent conductive film is described in detail in the supervision of Yutaka Sawada “New Development of Transparent Conductive Film” published by CMC (1999), and can be applied to the present invention. The transparent electrode 12 can be formed on the substrate 20 by a vacuum deposition method, a sputtering method, an ion plating method, or the like.
[0019]
The organic compound layer 13 may have a single-layer structure composed of only the light emitting layer, or may appropriately include other layers such as a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer in addition to the light emitting layer. A laminated structure may be used. Specific configurations (including electrodes) of the organic compound layer 13 include anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode, anode / light emitting layer / electron transport layer / cathode, anode / Examples include hole transport layer / light emitting layer / electron transport layer / cathode. A plurality of light emitting layers, hole transport layers, hole injection layers, and electron injection layers may be provided.
[0020]
The metal electrode 14 serving as a cathode is formed of a metal material such as an alkali metal such as Li or K having a low work function, an alkaline earth metal such as Mg or Ca, and an alloy or a mixture of these metals with Ag or Al. Preferably it is done. In order to achieve both storage stability and electron injectability at the cathode, the electrode formed of the above material may be further coated with Ag, Al, Au, etc. having a high work function and high conductivity. Note that, similarly to the transparent electrode 12, the metal electrode 14 can also be formed by a known method such as vacuum deposition, sputtering, or ion plating.
[0021]
(Configuration of substrate 20)
As shown in FIG. 2, the substrate 20 is formed in a plate shape having a thickness t. The transparent member 21 on which the organic EL element 11 is formed, and the wiring 18 of the organic EL element 11 are bonded to the transparent member 21. It is comprised with the member 22 for wiring in which is formed.
[0022]
The transparent member 21 is formed in a triangular prism shape having a substantially triangular cross section. Each side surface of the transparent member 21 has a reflecting surface 23 that is in contact with the wiring member 22, an element forming surface 24 on which the organic EL element 11 is formed, and light emitted from the organic EL element 11 is emitted to the outside. It acts as a light exit surface 25. The reflection surface 23 is formed so as to form an angle of 45 degrees with respect to the element formation surface 24 and reflects light from the element formation surface 24 toward the light emission surface 25. The light emitting surface 25 is formed so as to form an angle of 90 degrees with respect to the element forming surface 24.
[0023]
On the element forming surface 24 of the transparent member 21, the organic EL elements 11 are arranged in an array in the length direction, and the sealing member 16 shown in FIG. 3 is formed so as to cover these organic EL elements 11. ing.
[0024]
A plurality of wirings 18 are formed along the side surface of the wiring member 22. Each wiring 18 is obtained by extending the transparent electrode 12 of each organic EL element 11 formed on the transparent member 21, and is arranged so as to be parallel to each other.
[0025]
The reflecting surface 23 is not particularly limited as long as it reflects light from the element forming surface 24 in the direction of the light emitting surface 25. For example, the reflecting surface 23 is formed as follows.
[0026]
For example, as shown in FIG. 4, the transparent member 21 is composed of a medium having a refractive index n1, and the wiring member 22 is composed of a medium that transmits light having a refractive index n2 (<n1). At this time, the light emitted from the organic EL element 11 is reflected at the boundary between the transparent member 21 and the wiring member 22 and proceeds in the direction of the light emitting surface 25. That is, the boundary between the transparent member 21 and the wiring member 22 constitutes the reflecting surface 23.
[0027]
As shown in FIG. 5, when the transparent member 21 and the wiring member 22 are made of a medium having a refractive index n2, ions are implanted into the transparent member 21 so that the refractive index of the transparent member 21 is n1. May be.
[0028]
Further, as shown in FIG. 6, the reflective surface 23 may be formed by applying a reflective coating to the joint surface of the transparent member 21 or the wiring member 22 or sandwiching the reflective member between the transparent member 21 and the wiring member 22. Good.
[0029]
Furthermore, as shown in FIG. 7, an air layer may be formed between the transparent member 21 and the wiring member 22. At this time, the refractive index of air is smaller than the refractive index of the medium of the transparent member 21. Therefore, the light emitted from the organic EL element 11 is totally reflected at the boundary between the transparent member 21 and the air layer. That is, the transparent member 21 and the air layer act as the reflecting surface 23. In addition, since the reflective surface 23 is comprised by the transparent member 21 and an air layer, the member 22 for wiring does not need to be.
[0030]
Further, as shown in FIG. 8, the wiring member 22 may be made of a material that totally reflects light. Thereby, the surface of the wiring member 22 that comes into contact with the transparent member 21 becomes the reflecting surface 23.
[0031]
As described above, the exposure apparatus 1 totally reflects the light from the organic EL element 11 by the reflection surface 23 and performs exposure while changing the traveling direction of the light. Therefore, the degree of freedom of the arrangement position of the organic EL element 11 is large. As a result, as shown in FIG. 1, the width from each organic EL element array light source 10R to the organic EL element array light source 10B can be (3t + α). That is, since the interval between the organic EL element array light sources 10 is only α / 2, the outer shape of the SLA 30 can be reduced accordingly. As a result, the entire apparatus can be reduced in size.
[0032]
In addition, since the exposure apparatus 1 includes the wiring member 22 for forming the wiring of the organic EL element 11, the wiring can be easily designed without carrying out complicated wiring. Furthermore, as shown in FIG. 9, the height of each organic EL element array light source 10 can be changed. Thereby, connection with the wiring 18 and the other wiring 19 can be performed easily.
[0033]
The present invention is not limited to the embodiment described above, and may be configured as follows. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
[0034]
The reflection surface 23 of the substrate 20 is formed to form an angle of 45 degrees with respect to the element formation surface 24, but may be formed to form an angle within a range of 30 degrees to 60 degrees. Further, as shown in FIG. 10, the reflecting surface 23 may be a concave mirror so that the light emitted from the organic EL element 11 is condensed on the photosensitive member.
[0035]
The light emitting surface 25 is formed at an angle of 90 degrees with respect to the element forming surface 24, but may be formed at an angle within a range of 60 degrees to 120 degrees. Further, the light emitted from the organic EL element 11 may be condensed on the photosensitive member by making the light emitting surface 25 convex or by providing a convex lens on the light emitting surface 25. Thereby, the exposure of the photoreceptor can be performed efficiently.
[0036]
(Other configurations of the organic EL element array light source 10)
The organic EL element array light source 10 may be configured as described below. In the following description, the color emitted by each organic EL element 11 is not particularly limited, and the arrangement positions of the organic EL elements 11R, 11G, and 11B may be interchanged.
[0037]
For example, as shown in FIG. 11, the organic EL element array light sources 10R and 10G shown in FIG. 1 may be bonded together. Specifically, the surface opposite to the element formation surface 24R of the organic EL element array light source 10R and the surface opposite to the element formation surface 24G of the organic EL element array light source 10G are bonded together. Thereby, since it is not necessary to provide a gap between the organic EL element array light source 10R and the organic EL element array light source 10G, the apparatus can be reduced in size.
[0038]
Also, as shown in FIG. 12, organic EL elements 11R and 11G may be provided on opposite side surfaces (element formation surfaces 24R and 24G), respectively, with respect to a rectangular parallelepiped substrate 60 formed of a rectangular parallelepiped transparent medium. . The organic EL element 11B is formed on the other side surface of the rectangular parallelepiped substrate 60, which forms an angle of 90 degrees with the element formation surfaces 24R and 24G.
[0039]
In the rectangular parallelepiped substrate 60, reflecting surfaces 23R and 23G that reflect light from the organic EL elements 11R and 11G in the direction of the light emitting surface 25 (25R and 25G) are provided. The reflecting surface 23R is arranged to form an angle of 45 degrees with respect to the element forming surface 24R and the light emitting surface 25R. The reflecting surface 23G is disposed so as to form an angle of 45 degrees with respect to the element forming surface 24G and the light emitting surface 25G. The reflective surface 23R and the reflective surface 23G are provided with a predetermined distance across the transparent medium even at the closest location.
[0040]
With such a configuration, the blue light emitted from the organic EL element 11B travels in the direction of the light emission surface 25 while passing through the inside of the rectangular parallelepiped substrate 60, and is directly output through the reflection surfaces 23R and 23G. . That is, the light from the organic EL elements 11R, 11G, and 11B is output to the outside of the rectangular parallelepiped substrate 60 in the same direction.
[0041]
Thus, the rectangular parallelepiped substrate 60 on which the organic EL elements 11R, 11G, and 11B are formed can be reduced in size as compared with the organic EL element array light sources 10R, 10G, and 10B shown in FIG. Accordingly, the SLA can be reduced in size, so that the entire apparatus can be reduced in size.
[0042]
Furthermore, for example, as shown in FIG. 13, organic EL elements 11R, 11G, and 11B that emit red, green, and blue light may be stacked. As a result, the light of the three primary colors emitted from the organic EL elements 11R, 11G, and 11B is reflected by the reflecting surface 23 to expose the same spot on the photoreceptor.
[0043]
Therefore, although the exposure apparatus 1 shown in FIG. 1 requires three organic EL element array light sources 10, one organic EL element array light source 10 is sufficient in the present embodiment. Thereby, since the organic EL element array light source 10 can be reduced as compared with the exposure apparatus 1, the apparatus can be further downsized.
[0044]
As shown in FIG. 14, a temperature control element 27 may be provided on the opposite side of the element formation surface 24 of the organic EL element array light source 10 shown in FIG. The temperature control element 27 is required to have general substrate characteristics such as heat resistance, dimensional stability, solvent resistance, electrical insulation, workability, low air permeability, and low moisture absorption. Examples of the temperature control element 27 include a ceramic Peltier element, a ceramic heater, a thermoelectric cooler, and the like.
[0045]
With such a configuration, the temperature of the substrate 20 can be controlled with high accuracy and efficiency, and the temperature of the substrate 20 can be made substantially constant when the organic EL element 11 outputs a high luminance. Therefore, the thermal deterioration of the organic EL element 11 accompanying the temperature rise of the substrate 20 is suppressed, and the durability of the organic EL element 11 can be improved.
[0046]
Further, as shown in FIG. 15, a transparent substrate 70 is disposed in close contact with each organic EL element array light source 10R, 10G, 10B, and the organic EL element 11R of the organic EL element array light source 10R is coated with an adhesive 71. The gaps between the organic EL element array light sources 10R, 10G, and 10B may be sealed with an adhesive 71.
[0047]
The substrates 20R, 20G, and 20B of the organic EL element array light sources 10R, 10G, and 10B are preferably formed in a rectangular shape so that the transparent substrate 70 can be placed in close contact with each other. At this time, the transparent substrate 70 is disposed in close contact with the end surfaces of the substrates 20R, 20G, and 20B, that is, the light emitting surfaces 25R, 25G, and 25B. The organic EL elements 11R, 11G, and 11B are formed on the main surfaces of the substrates 20R, 20G, and 20B, that is, the element formation surfaces 24R, 24G, and 24B. The adhesive 71 needs not to generate a gas that affects the organic layer.
[0048]
Thereby, since each organic EL element 11 can be isolated from oxygen and moisture, the durability of the organic EL element 11 can be improved. Alternatively, the organic EL element array light sources 10R, 10G, and 10B on which the organic EL elements 11R, 11G, and 11B are formed may be stacked.
[0049]
The organic EL element 11R that emits red light has a particularly low emission luminance and a long exposure time compared to the organic EL elements 11G and 11B that emit green and blue light. Therefore, instead of the organic EL element 11R that emits red light, a light emitting diode (LED) that emits red light may be provided to perform the exposure time in a short time.
[0050]
【The invention's effect】
The present invention, the degree of freedom of installation position of the perforated electromechanical field light-emitting element is increased, as a result, it is possible to reduce the overall size of the device.
[Brief description of the drawings]
FIG. 1 is a perspective view of an exposure apparatus according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a configuration of an organic EL element array light source of the exposure apparatus.
FIG. 3 is a cross-sectional view showing a configuration of an organic EL element formed in an organic EL element array light source.
FIG. 4 is a schematic cross-sectional view showing another configuration of the transparent substrate.
FIG. 5 is a schematic cross-sectional view showing another configuration of the transparent substrate.
FIG. 6 is a schematic cross-sectional view showing another configuration of the transparent substrate.
FIG. 7 is a schematic cross-sectional view showing another configuration of the transparent substrate.
FIG. 8 is a schematic cross-sectional view showing another configuration of the transparent substrate.
FIG. 9 is a schematic cross-sectional view showing another configuration of the organic EL element array light source.
FIG. 10 is a schematic cross-sectional view showing another configuration of the organic EL element array light source.
FIG. 11 is a schematic cross-sectional view showing another configuration of the organic EL element array light source.
FIG. 12 is a schematic cross-sectional view showing another configuration of the organic EL element array light source.
FIG. 13 is a schematic cross-sectional view showing another configuration of the organic EL element array light source.
FIG. 14 is a schematic cross-sectional view showing another configuration of the organic EL element array light source.
FIG. 15 is a schematic cross-sectional view showing another configuration of the organic EL element array light source.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Exposure apparatus 10 Organic EL element array light source 11 Organic EL element 20 Transparent substrate 23 Bonding surface 40 Photoconductor

Claims (1)

A light-transmitting substrate that is formed in a rectangular parallelepiped shape and that is formed by separating two reflecting surfaces that reflect light incident from two opposing element forming surfaces in the direction of the light emitting surface;
First and second organic electroluminescence elements that are respectively provided on the two element formation surfaces and emit different colors;
The side surface of the light-transmitting substrate is provided on a side surface different from the two element formation surfaces, emits a color different from that of the first and second organic electroluminescence elements in the light emitting surface direction, and emits the light. A third organic electroluminescent element that passes between the two reflecting surfaces and emits from the light emitting surface ,
An exposure apparatus that exposes a photosensitive member with light emitted from a light emitting surface of the light transmissive substrate.

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