JP2005035206A - Exposing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high definition exposing device using a waveguide and an image forming apparatus. <P>SOLUTION: This exposing device comprises the waveguides consisting of a plurality of cores which are arranged mutually in parallel and optically separated in a main scanning direction by each of pixels of which the end faces in at least the sub-scanning direction are made to be light-taking faces, and a light source formed on the waveguides capable of emitting a light according to an input signal. The exposing device uses as the exposing light the light which is incident on the waveguides by being emitted from the light source and is radiated from the light-taking face. The waveguides are constituted of two or more rows thereof. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exposure apparatus and an image forming apparatus using a waveguide.

  As an exposure apparatus for a printer, an exposure apparatus using a laser diode as a light source is generally well known, or in recent years, an LED array in which light emitting diodes (inorganic LEDs) for the purpose of space saving are arranged in an array. Have been put to practical use, and light-emitting elements made of these inorganic semiconductors have been put into practical use as light sources for electrophotographic printer exposure apparatuses.

  As light sources other than these light sources, light sources using electroluminescent elements are also well known. An electroluminescence element is a light-emitting device that utilizes electroluminescence of a solid fluorescent substance. Currently, an inorganic electroluminescence element using an inorganic material as a light emitter has been put into practical use, and is used for backlights and flat displays of liquid crystal displays. The application development of is partly planned. However, the inorganic electroluminescence element has a high voltage required for light emission of 100 V or more, and the refractive index of the material used as the light emitter is very large, so that it is strongly affected by total reflection at the interface, and the light emitting layer There is a problem that only 10 to 20% of the emitted light is used.

  On the other hand, research on organic electroluminescence devices using organic materials as the light-emitting layer has attracted attention for a long time, and various studies have been conducted. However, since the luminous efficiency is very low, full-scale practical research has progressed. There wasn't.

However, as disclosed in (Non-patent Document 1), Kodak's C.I. W. Tang et al. Proposed an organic electroluminescent device having a function-separated stacked structure in which an organic material is divided into two layers, a hole transport layer and a light-emitting layer, and 1000 cd / m ² or more despite a low voltage of 10 V or less. It was revealed that a high emission luminance can be obtained. Since then, organic electroluminescence devices have attracted a great deal of attention, and research on organic electroluminescence devices having a similar functionally separated type laminated structure has been actively conducted, especially for practical application of organic electroluminescence devices. In addition, high efficiency and long life which are indispensable for the use have been sufficiently studied, and in recent years, displays using organic electroluminescence elements as light sources have been put into practical use.

  Here, the structure of the conventional general organic electroluminescent element is demonstrated using FIG.

  FIG. 15 is a cross-sectional view of a main part of a conventional organic electroluminescence element.

  In FIG. 15, 15 is a substrate, 11 is an anode, 14 is a hole transport layer, 10 is a light emitting layer, and 9 is a cathode.

As shown in FIG. 15, the organic electroluminescence element includes an anode 11 made of a transparent conductive film such as ITO formed on a substrate 15 made of glass or the like by a sputtering method, a resistance heating vapor deposition method, or the like, and an anode 11 N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-diphenyl-4,4′-diamine (hereinafter referred to as TPD) formed on the same by the resistance heating vapor deposition method or the like. A light-emitting layer 10 made of 8-hydroxyquinoline aluminum (hereinafter abbreviated as Alq ₃ ) formed on the hole-transport layer 14 by a resistance heating vapor deposition method or the like. And a cathode 9 made of a metal film having a thickness of 100 nm to 300 nm formed on the light emitting layer 10 by a resistance heating vapor deposition method or the like.

  When a direct current voltage or direct current is applied with the anode 11 of the organic electroluminescence element having the above configuration as a positive electrode and the cathode 9 as a negative electrode, holes are generated from the anode 11 to the light emitting layer 10 through the hole transport layer 14. Then, electrons are injected from the cathode 9 into the light emitting layer 10. In the light emitting layer 10, recombination of holes and electrons occurs, and a light emission phenomenon occurs when excitons generated thereby shift from the excited state to the ground state.

In addition, about the element structure of an organic electroluminescent element, there exist some which are disclosed by (patent document 1), (patent document 2), etc.
Tan (C. W. Tang), V. Vanslyke, “Appl. Phys. Lett” (USA), Vol. 51, 1987, p. 913 US Pat. No. 5,917,280 US Pat. No. 5,932,895

  However, in recent years, there has been a strong demand for higher performance for printers, and printer exposure devices are also required to have characteristics for realizing high-speed and high-quality printing. Therefore, the printer exposure apparatus is required to have a large light quantity for realizing high-speed printing or fine pitch pixels for realizing high-quality printing.

  In order to achieve high-speed and high-quality printing in conventional exposure systems that use laser diodes, the accuracy of the optical system and the driving accuracy of the drive unit such as the polygon mirror become very severe, and vibration and noise Such problems also occur. Further, since it is necessary to sufficiently reduce the laser spot diameter itself, it is difficult to realize a high-definition exposure apparatus.

  A printer exposure apparatus using inorganic LEDs as a light source, which is a so-called solid scanning exposure apparatus that does not scan exposure light, has a structure in which a plurality of inorganic LED chips are arranged, and has recently been put into practical use. . However, since it has a structure in which a plurality of LED chips are arranged, the print quality is deteriorated due to, for example, a positional deviation between adjacent chips or a light amount variation between adjacent chips, and it is difficult to realize a high-definition exposure apparatus. .

  In addition, when an organic electroluminescence element is used, since a long printer exposure device can be formed at once, there is no problem between adjacent elements, but the life of the organic electroluminescence element is not enough, etc. A sufficient amount of light as a printer exposure device cannot be obtained, and it has not been put into practical use. Furthermore, fine pixels must be arranged in the organic electroluminescence element, which causes problems such as short circuit between adjacent pixels and insulation.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high-speed and high-definition image forming apparatus that is bright at a fine pitch and by using this exposure apparatus.

The exposure apparatus according to the present invention includes a plurality of light sources that can emit light at least in response to an input signal and optically separated in the main scanning direction for each pixel whose end surface in the sub-scanning direction is a light extraction surface. Is an exposure apparatus that uses, as exposure light, light emitted from the light source, incident on the waveguide, and emitted from the light extraction surface. The waveguide is composed of at least two or more stages of waveguides.

  As described above, since the waveguide is composed of two or more waveguides, the space between adjacent pixels of the light source can be sufficiently larger than the pitch required by the exposure apparatus. An exposure apparatus can be easily formed, and a bright exposure apparatus can be easily formed by increasing the core portion.

  According to the present invention, a waveguide in which a plurality of optically separated pixels in the main scanning direction are arranged in parallel with each other and each of the pixels whose end faces in the sub-scanning direction are light extraction surfaces is provided. An exposure apparatus that uses light emitted from the light source to enter the waveguide and emitted from the light extraction surface as exposure light. The waveguide is composed of at least two or more stages of waveguides, so that a bright exposure apparatus with a fine pitch can be easily formed. Furthermore, by using this exposure apparatus, a high-speed and high-definition image forming apparatus can be easily provided.

  According to a first aspect of the present invention, there is provided a waveguide in which a plurality of pixels optically separated in the main scanning direction are arranged in parallel to each other at least for each pixel whose end surface in the sub-scanning direction is a light extraction surface. And a light source that can emit light according to an input signal formed on the waveguide, and that uses the light emitted from the light source to enter the waveguide and emitted from the light extraction surface as exposure light The exposure apparatus is characterized in that the waveguide is composed of at least two or more stages of waveguides, and an exposure apparatus having a large light source area can be easily formed without increasing the area of the light extraction surface. A bright exposure apparatus can be realized, and brightness equal to or higher than that of the single-stage waveguide can be obtained even if the waveguide interval in the same stage is widened and the area of the light source is reduced. Because of the waveguide Preparation of the light source and it is possible to realize an easy exposure apparatus. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

  According to a second aspect of the present invention, there is provided the exposure apparatus according to the first aspect, wherein the waveguides have substantially the same pitch and phase of the waveguides arranged in adjacent stages. Yes, an exposure apparatus with a large light source area can be easily realized without increasing the area of the light extraction surface, a bright exposure apparatus can be realized, and the waveguide spacing in the same stage can be widened. Even if the area of the light source is reduced, the brightness equal to or higher than that of the single-stage waveguide can be obtained, so that it is possible to realize an exposure apparatus that can easily manufacture the waveguide and the light source. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized, and the pitch and phase of the waveguides arranged in adjacent stages are substantially the same. A bright exposure apparatus can be easily realized without introducing a control mechanism such as a complicated control circuit and control signal.

A third aspect of the present invention is the exposure apparatus according to the first aspect, wherein the waveguides have the same pitch of the waveguides arranged in adjacent stages, and the phase shift is an integer less than the number of stages. This exposure device is characterized by approximately the same value as the divided value, and can easily realize an exposure device with a large light source area without increasing the area of the light extraction surface, thereby realizing a bright exposure device. In addition, it is possible to obtain a brightness equivalent to or higher than that of a single-stage waveguide even if the waveguide interval in the same stage is widened and the area of the light source is reduced. An exposure apparatus can be realized. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized, and the pitch of the waveguides arranged in adjacent stages is the same, and the phase shift is the pitch. Is substantially the same as the value obtained by dividing the number by an integer equal to or less than the number of stages, and therefore, high-definition exposure more than the waveguide pitch can be easily realized.

  A fourth aspect of the present invention is the exposure apparatus according to the first aspect, wherein the waveguides have the same pitch of the waveguides arranged in adjacent stages, and the phase shift is approximately one half of the pitch. It is an exposure apparatus characterized by being capable of easily realizing an exposure apparatus with a large light source area without increasing the area of the light extraction surface, realizing a bright exposure apparatus, Even if the waveguide interval in the same stage is widened and the area of the light source is reduced, the brightness equal to or higher than that of the single-stage waveguide can be obtained. Therefore, an exposure apparatus that can easily manufacture the waveguide and the light source is realized. Can do. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized, and the pitch of the waveguides arranged in adjacent stages is the same, and the phase shift is the pitch. Therefore, high-definition exposure that is twice the waveguide pitch can be easily realized without introducing a complicated control circuit, control mechanism such as a control signal, and the like.

  A fifth aspect of the present invention is the exposure apparatus according to any one of the first to fourth aspects, wherein the waveguide has a light shielding layer formed between adjacent stages. Yes, an exposure apparatus with a large light source area can be easily realized without increasing the area of the light extraction surface, a bright exposure apparatus can be realized, and the waveguide spacing in the same stage can be widened. Even if the area of the light source is reduced, the brightness equal to or higher than that of the single-stage waveguide can be obtained, so that it is possible to realize an exposure apparatus that can easily manufacture the waveguide and the light source. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized. In addition, since stray light propagating between adjacent stages can be reduced by the light shielding layer, the exposure apparatus capable of performing high-definition exposure with little optical crosstalk can be realized.

  A sixth aspect of the present invention is the exposure apparatus according to any one of the first to fifth aspects, wherein the waveguide has a taper formed on a surface facing the light extraction surface. Since the exposure apparatus can easily form wiring in light sources formed in different stages, an exposure apparatus having a large light source area can be easily realized without increasing the area of the light extraction surface. A bright exposure apparatus can be realized, and even if the waveguide interval in the same stage is widened and the area of the light source is reduced, brightness equal to or higher than that of the single-stage waveguide can be obtained. An exposure apparatus that can easily produce a light source can be realized. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

  A seventh aspect of the present invention is the exposure apparatus according to the sixth aspect, wherein the light source is not formed on the tapered portion of the waveguide, and the light emitted from the adjacent stage. Therefore, it is possible to easily realize an exposure apparatus having a large light source area without increasing the area of the light extraction surface, to realize a bright exposure apparatus, and to guide the light in the same stage. Even if the waveguide interval is widened and the area of the light source is reduced, the brightness equal to or higher than that of the single-stage waveguide can be obtained, so that an exposure apparatus that can easily manufacture the waveguide and the light source can be realized. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

The invention according to claim 8 is a waveguide in which a plurality of optically separated pixels in the main scanning direction are arranged in parallel to each other at least for each pixel whose end surface in the sub-scanning direction is a light extraction surface. And a light source that can emit light according to an input signal formed on the waveguide, and that uses the light emitted from the light source to enter the waveguide and emitted from the light extraction surface as exposure light The light source is an exposure apparatus characterized in that the light source is formed on at least two opposing surfaces of the waveguide. Since the waveguide interval can be widened without reducing the area of the light source, the light source is short-circuited. Thus, it is possible to realize an exposure apparatus that can easily produce a light source that is less affected by the above. Further, since the light source can be easily formed, a high-definition exposure apparatus in which the area of the light extraction surface of the waveguide is reduced can be easily realized with a high yield.

  A ninth aspect of the present invention is the exposure apparatus according to the eighth aspect, wherein the light source includes a light source in which at least an electrode facing the substrate is a transparent electrode. Since the waveguide interval can be widened without reducing the area, it is possible to realize an exposure apparatus that can easily produce a light source that is less affected by a short circuit or the like. Further, since the electrode on the side facing the substrate is formed of a transparent electrode, it is not necessary to use a waveguide as the substrate. Therefore, a small waveguide can be easily used, and a small exposure apparatus can be realized. . Further, since the light source can be easily formed, a high-definition exposure apparatus in which the area of the light extraction surface of the waveguide is reduced can be easily realized with a high yield.

  A tenth aspect of the present invention is the exposure apparatus according to any one of the eighth to ninth aspects, wherein the waveguide includes at least two or more stages of waveguides, An exposure apparatus having a large light source area can be easily realized without increasing the area of the light extraction surface, and a bright exposure apparatus can be realized, and the waveguide interval can be reduced without reducing the area of the light source. Since it can be widened, it is possible to realize an exposure apparatus that can easily produce a light source that is less affected by a short circuit or the like. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

  The invention according to claim 11 is the exposure apparatus according to any one of claims 1 to 10, wherein the light source includes at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons. It is an exposure device characterized by comprising an organic electroluminescence element equipped with it, and it can easily realize an exposure device with a large light source area without increasing the area of the light extraction surface, realizing a bright exposure device In addition, it is possible to obtain a brightness equivalent to or higher than that of a single-stage waveguide even if the waveguide interval in the same stage is widened and the area of the light source is reduced. An exposure apparatus can be realized. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized. In addition, since a bright light source can be easily formed without increasing the burden on the light emitting element, a bright point light source can be easily realized by using an organic electroluminescence element having a problem in life.

  The invention described in claim 12 is the exposure apparatus according to any one of claims 1 to 11, wherein the refractive index of the core of the waveguide is larger than a value obtained by subtracting 0.3 from the refractive index of the light emitting layer. The light emitted from the light emitting layer can be efficiently incident on the waveguide, and a bright exposure apparatus can be realized. In addition, since an exposure apparatus having a large light source area can be easily realized without increasing the area of the light extraction surface, a bright exposure apparatus can be realized and the waveguide interval in the same stage can be widened. However, since the brightness equal to or higher than that of the single-stage waveguide can be obtained even if the area of the light source is reduced, it is possible to realize an exposure apparatus that can easily manufacture the waveguide and the light source. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

A thirteenth aspect of the present invention is the exposure apparatus according to any one of the first to twelfth aspects, wherein the waveguide is formed using the same material as the light emitting layer. It is possible to realize a bright exposure apparatus that can easily enter the light emitted from the light emitting layer into the waveguide without considering the refractive index of the waveguide. In addition, an exposure apparatus with a large light source area can be easily realized without increasing the area of the light extraction surface, a bright exposure apparatus can be realized, and the waveguide interval in the same stage can be widened. Even if the area of the light source is reduced, the brightness equal to or higher than that of the single-stage waveguide can be obtained, so that it is possible to realize an exposure apparatus that can easily manufacture the waveguide and the light source. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

  A fourteenth aspect of the present invention is the exposure apparatus according to any one of the first to thirteenth aspects, wherein a light shielding layer or a reflective layer is provided between waveguides adjacent to each other. The exposure apparatus can easily realize an exposure apparatus having a large light source area without increasing the area of the light extraction surface, and can realize a bright exposure apparatus, and also can provide a waveguide interval within the same stage. Even if the area of the light source is reduced and the area of the light source is reduced, the brightness equal to or higher than that of the single-stage waveguide can be obtained. Therefore, it is possible to realize an exposure apparatus in which the waveguide and the light source can be easily manufactured. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized. Further, since the stray light propagating between the adjacent waveguides can be reduced by the light shielding layer, the exposure apparatus capable of performing high-definition exposure with little optical crosstalk can be realized. Alternatively, the reflection layer can use light that has been wasted in the waveguide as effective light, so that the light use efficiency can be improved, and optical crosstalk can be achieved without arranging a light shielding layer. An exposure apparatus that can perform high-definition exposure with a small amount of light can be realized.

  A fifteenth aspect of the present invention is the exposure apparatus according to any one of the first to fourteenth aspects, wherein the light extraction surface has a shape corresponding to a pixel shape, and the light extraction surface An exposure apparatus with a large light source area can be easily realized without increasing the area of the light source, a bright exposure apparatus can be realized, and the waveguide spacing in the same stage is widened to reduce the area of the light source. However, since the brightness equal to or higher than that of the single-stage waveguide can be obtained, an exposure apparatus that can easily manufacture the waveguide and the light source can be realized. In addition, by making the shape of the light extraction surface of the waveguide a shape corresponding to the pixel shape, a high-definition exposure apparatus can be easily realized.

  A sixteenth aspect of the invention is the exposure apparatus according to any one of the first to fifteenth aspects, wherein an angle of light incident on the waveguide from the light emitting layer is converted into the waveguide and led to the light extraction surface. The exposure apparatus is characterized in that an angle conversion structure is formed, and light emitted from the light source can be efficiently propagated to the light extraction surface, so that a bright exposure apparatus can be easily realized. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

  A seventeenth aspect of the present invention is the exposure apparatus according to any one of the first to sixteenth aspects, wherein the light emitted from the light extraction surface forms an image on the photosensitive member at an equal magnification. An exposure apparatus that can easily form an image without using a complicated optical system can be realized. An exposure apparatus having a large light source area can be easily realized without increasing the area of the light extraction surface, and a bright exposure apparatus can be realized. Even if the area is reduced, brightness equal to or higher than that of the single-stage waveguide can be obtained, so that an exposure apparatus that can easily manufacture the waveguide and the light source can be realized. Also, by reducing the area of the light extraction surface of the waveguide, a high-definition exposure apparatus can be easily realized.

  According to an eighteenth aspect of the present invention, there is provided an image forming apparatus comprising: the exposure apparatus according to any one of the first to seventeenth aspects; and a photoconductor on which an electrostatic latent image is formed by the exposure apparatus. Since a bright and high-definition exposure apparatus can be used, a high-speed and high-definition image forming apparatus can be realized.

A nineteenth aspect of the present invention is the image forming apparatus according to the eighteenth aspect, wherein the image forming apparatus is alternately lit, and a photosensitive member on which an electrostatic latent image is formed by an exposure device; An image forming apparatus characterized by having a bright and high-definition exposure apparatus, so that a high-speed and high-definition image forming apparatus can be realized and the exposure apparatus has a long life. A forming apparatus can be realized.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. In these drawings, the same members are denoted by the same reference numerals, and redundant description is omitted.

  First, a color image forming apparatus using the exposure apparatus of the present invention will be described with reference to FIG.

  FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, 1 is an exposure unit, 2 is a photosensitive member, 3 is a charger, 4 is a developing unit, 5 is a transfer unit, 6 is a cleaner, and 7 is a fixing unit.

  The photoconductor 2 includes at least a support member 2a and a photoconductive layer 2b whose conductivity is changed by irradiating light, and controls the conductivity of the surface of the photoconductor 2 by irradiating light to cope with image information. Image can be formed.

  The photosensitive member 2 having a non-uniform surface potential distribution is uniformly charged to a predetermined potential on the surface of the photosensitive member 2 by charging by a charging means indicated by a charger 3 using a contact or non-contact charging method. Forming a charged surface. As a charging method, the surface of the photoconductor 2 is charged by corona discharge without contact, and a charging unit such as a charging roller, a fur brush roller, a magnetic brush roller, or a charging blade that applies a voltage to the surface of the photoconductor 2 is contacted. In recent years, the contact charging method has been put to practical use for the reason that the generation of ozone can be suppressed or the power consumption in the charging unit is small, and any charging method may be used. The bias applied to the photosensitive member 2 may be a DC bias, but an alternating bias such as a sine wave, a rectangular wave, or a triangular wave may be applied, and a bias composed of an arbitrary periodic ON / OFF signal may be used.

  By irradiating the charged surface of the photosensitive member 2 with light based on the image information using the exposure means indicated by the exposure unit 1, an electrical potential having a surface potential corresponding to the image information is formed on the photosensitive member charged surface. A latent image is formed.

  This electrical latent image is developed as a toner image on the surface of the photoreceptor 2 corresponding to image information by attaching an insulating toner by electrostatic force in a toner attaching means shown by the developing device 4. The development method includes a contact development method, a non-contact development method, a one-component development method, a two-component development method, a reversal development method, and a regular development method, and any development method can be used. Good. The applied voltage in the developing device 4 is the same as the bias in the charger 3, and any direct current or alternating bias can be appropriately selected and used.

  Further, the toner image on the photosensitive member 2 is transferred to a toner image on a transfer material such as an intermediate transfer member composed of a paper surface or a belt or a drum by a predetermined pressing force and a transfer bias in a toner transfer unit as shown by a transfer unit 5. Is transcribed as As a transfer method, there are transfer methods such as roller transfer, blade transfer, and corona discharge transfer, which can be appropriately selected and used.

The transfer material finally receiving the toner image is separated from the surface of the photosensitive member 2 and finally fixed on the surface of the object to be printed by fixing means such as thermal fixing as shown by the fixing unit 7 and discharged as a printed matter. . Further, the surface of the photoreceptor 2 after the toner image transfer is appropriately cleaned by removing the remaining toner by a cleaning means or the like shown as a cleaner 6.

  In the case of a monochrome printer, black toner is used as the toner, and the image forming apparatus, the fixing unit, the paper supply / discharge unit and the like are realized as a monochrome printer.

  In the case of a full-color printer, four different toner adhering means are used, and black toner, cyan toner, magenta toner, and yellow toner are developed and transferred as latent images corresponding to the respective image information as respective toner images. It is transferred onto the printed material as a predetermined full-color printed material. Alternatively, a full color printed material can be realized by developing and transferring a plurality of pieces of image information as a single toner image for the latent images corresponding to the respective image information. Alternatively, a plurality of image forming apparatuses are arranged corresponding to black, cyan, magenta, and yellow, and a full color printed material is realized by transferring each toner image. Also, these arbitrary processes can be combined into one removable process cartridge.

  In the image forming apparatus having such a configuration, first, a latent image is formed on the photoreceptor in accordance with the image information of the yellow component, and transfer is performed. At this time, a latent image of the magenta component is formed at the same time, and the transfer of the magenta component is performed following the transfer of the yellow component. In the same manner, the toner images are superimposed in the order of the cyan component and the black component, and a full-color print is formed.

  In the present invention, an image forming apparatus such as a copying machine or a printer that can be easily printed in a small size, at a low price, and at high speed can be realized by using a small size, low price, and large light quantity exposure device for the exposure unit 1. Can do.

  FIG. 2 is an explanatory diagram showing in detail an exposure unit in the image forming apparatus of FIG.

  In FIG. 2, 8 is an erecting equal-magnification optical system, 9 is a cathode, 10 is a light emitting layer, 11 is an anode, 12 is a core, 12a is a light emitting surface, and 13 is a cladding. Reference numeral 100 denotes an exposure apparatus.

  An erecting equal-magnification optical system 8 is disposed between the light emitting surface 12 a of the waveguide formed from the core 12 and the clad 13 and the photosensitive member 2. Normally, the light emitted from the light exit surface 12a serving as the end face of the waveguide propagates as diffused light. By forming this erecting equal-magnification optical system 8 between the photosensitive member 2, the light exit surface 12a. The light emitted from the light is imaged on the photoconductor 2 and light can be applied only to a portion of the photoconductor 2 corresponding to a desired pixel. With such a configuration, it is possible to easily combine the exposure apparatus 100 and the photoreceptor 2 to realize an image forming apparatus.

  Note that the erecting equal-magnification optical system 8 can easily form an image on the photoconductor 2, but the light exposure surface 12 a of the waveguide and the photoconductor 2 are exposed on the photoconductor 2. It is sufficient that an optical system for forming an image corresponding to light is formed. A lens array formed for each pixel, a cylindrical lens uniform in the main scanning direction, an optical system such as a prism array, or between adjacent pixels. It is only necessary to form a light shielding means such as a light shielding film for eliminating the optical crosstalk.

  FIG. 3 is a perspective view showing the main part of the exposure apparatus in the exposure unit of FIG. 2, and FIG. 4 shows a cross-sectional view of the main part showing in detail the waveguide and light source of the exposure apparatus of FIG. FIG. 4 shows a cross section cut along a plane orthogonal to the light emitting direction of the waveguide.

As shown in FIGS. 3 and 4, the waveguide formed from the core 12 and the cladding 13 in the exposure apparatus 100 sandwiches a light source composed of the light emitting layer 10 and the cathode 9 disposed between the anodes 11, Two upper and lower stages are provided, and the pitches of the waveguides are substantially equal to each other, so that there is no phase shift and they are opposed to each other at the same position. That is, a light source is disposed between the stages of the waveguide, and is formed of two substantially upper and lower waveguides having the same pitch, and the multistage waveguide can be easily obtained without considering light leakage between the waveguides. Can be formed. In the case of the first embodiment, the adjacent stage waveguide in the present invention means a two-stage waveguide formed vertically with a light source interposed therebetween.

  In particular, as in this configuration, by forming an exposure apparatus using a waveguide of another stage using the cathode 9 as a common electrode, it is possible to easily conduct multistage conduction without considering conduction, insulation, etc. between light sources at different stages. Waveguides can be formed.

  In an exposure apparatus that forms a light source on a waveguide, light emitted from the light source propagates while being reflected and refracted at the core / cladding interface of the waveguide according to Snell's law. Therefore, in a light source that emits light isotropically, for example, an organic electroluminescence element, light emitted at an angle larger than the critical angle repeats total reflection at the core / cladding interface, so that the waveguide Propagate through.

  In particular, in the present invention, the light advances through the core 12 surrounded by the clad 13 while repeating total reflection, and reaches the end face in the sub-scanning direction. In the present invention, the end face of the waveguide in the sub-scanning direction is used as a light extraction surface, and light emitted from this light extraction surface is used as exposure light.

  Therefore, when the light is emitted through the waveguide, it is preferable that the electrode on the side in contact with the core 12 (in this case, the anode 11) has a high light transmittance, and in particular, the length of the waveguide portion is sufficient. When it is long, the attenuation of light becomes large. Therefore, the light transmittance of the anode 11 here is more preferably 75% or more.

  3 and 4, the case where the electrode on the side in contact with the core 12 is an anode has been described. However, when the electrode on the side in contact with the core 12 is a cathode, the light transmittance of the cathode can be increased. That's fine.

  In order to efficiently propagate the light emitted into the waveguide to the light extraction surface, the refractive index of the waveguide is preferably smaller than the refractive index of the light emitting layer. It is preferable that the value is larger than 0.3. This is because the light emitted from the light emitting layer is propagated according to Snell's law at each interface, so that when the refractive index of the waveguide is larger than the refractive index of the light emitting layer, the light in the waveguide is incident on the light extraction surface. On the other hand, the light at the sleeping angle increases, and the optical path length until reaching the light extraction surface is increased. Since such light is strongly affected by light absorption and scattering in the waveguide or other layers, efficient light propagation is not performed. On the other hand, when the refractive index of the waveguide is almost the same as or smaller than the refractive index of the light emitting layer, a lot of light propagates in the direction of the light exit surface in the waveguide, and the light efficiently Will be propagated. However, when the refractive index of the waveguide is smaller than the refractive index of the light emitting layer, total reflection of light occurs at the interface with the waveguide according to the refractive index difference between the waveguide and the light emitting layer. Light emitted into the waveguide is reduced. In particular, when the refractive index of the light emitting layer is smaller than 0.3 as compared with the refractive index of the waveguide, this reduction in the amount of light due to total reflection cannot be ignored, and efficient light propagation is not performed. Therefore, by forming the waveguide using the same material as the light emitting layer, it is possible to easily form a waveguide through which efficient light is propagated without strictly selecting the refractive index of the waveguide.

Further, in order to obtain exposure light that is sufficiently independent between the waveguides of adjacent stages, it is preferable that a light shielding layer or a reflective layer is provided between the adjacent stages. With such a configuration, light does not enter from the adjacent waveguides, so that there is no variation in the amount of light extracted from the light extraction surface between the waveguides. In particular, when a reflective layer is provided, light that is incident on another waveguide in the adjacent stage and propagates as invalid light propagates as effective light, and thus is more efficiently guided to the light extraction surface. It has the effect that it is possible to further increase the amount of light.

  In the case shown in FIG. 3 and FIG. 4, since the light emitting layer 10 is arranged with the cathode 9 as a common electrode between adjacent stages, the cathode 9 functions as a reflective layer, and the adjacent stages Independent exposure light can be obtained. Although details will be described later, in the case where the light emitting layer 10 is not disposed between adjacent stages, it is preferable to provide a light-shielding layer or a reflective layer between adjacent stages. The light shielding layer or the reflective layer can be formed by an easy method such as forming the light shielding layer or the reflective layer, or forming the clad portion of the waveguide by the light shielding layer or the reflective layer. By forming it, it is possible to obtain exposure light that is well independent between the adjacent waveguides.

  Further, in order to obtain exposure light that is satisfactorily independent between the waveguides in the same stage, it is preferable that a light shielding layer or a reflective layer is provided between the waveguides adjacent to each other. . With such a configuration, light does not enter from other adjacent waveguides, so that there is no variation in the amount of light extracted from the light extraction surface between the waveguides. In particular, when a reflective layer is provided, light that is incident on another waveguide and propagates as invalid light propagates as effective light, and thus is more efficiently guided to the light extraction surface. It has the effect of being able to increase. A light shielding layer or a reflective layer is formed by an easy method such as forming a light shielding layer or a reflective layer between adjacent waveguides when forming a waveguide, or forming a cladding portion of the waveguide by a light shielding layer or a reflective layer. By forming the light shielding layer or the reflection layer, it is possible to obtain exposure light that is well independent between the adjacent waveguides.

  When the light extraction surface has a shape corresponding to the pixel shape, a member for converting the exposure light emitted from the light extraction surface into the pixel shape is not required, and thus the exposure apparatus can be easily reduced in size and thickness. it can. Further, since the light extraction surface has a shape corresponding to the pixel shape, the design of the shape of the light extraction surface has an effect that a high-definition latent image can be easily formed.

  As described above, when light propagates through the waveguide and exits from the light extraction surface, the sleeping light increases. Therefore, in order to prevent this, the effect of sleeping light can be suppressed by providing a light propagation angle conversion structure on the waveguide surface and forming an angle conversion unit for guiding light to the light extraction surface. In order to obtain efficient light propagation, it is preferable to have an angle conversion structure for converting the angle of light inside the waveguide, rather than a waveguide having a simple shape. This is because, for example, when a saw blade-shaped angle conversion structure that converts the angle of light in the direction of the light extraction surface is provided, an angle that does not propagate through the waveguide in a simple-shaped waveguide By performing angle conversion on the light, it can be used as effective light emitted from the light extraction surface. In a simple waveguide, light propagating through the waveguide rarely reaches the interface between the waveguide and air without performing angle conversion of the light. Propagate through the waveguide. As described above, since the light has an angle conversion structure inside the waveguide, light passing through the waveguide can be propagated in a simple waveguide, and efficient light propagation can be realized.

In the case where the waveguide is a waveguide composed of a core having a large refractive index and a clad having a smaller refractive index, the light angle conversion structure is preferably provided at the interface between the core and the cladding. When effective angle conversion of light is performed at the interface between the core and the clad, the light subjected to angle conversion propagates through the core and is emitted from the light extraction surface. On the other hand, when an angle conversion structure is provided at the interface between the clad and air, the light that has undergone effective angle conversion becomes light that propagates through both the core and the clad, and is emitted from the light extraction surface. . For this reason, when the angle conversion structure of light is provided at the interface between the core and the clad, the optical path length when propagating through the waveguide can be shortened, and the light can be efficiently propagated on the clad surface.

  When the light emitting element is not formed on the surface facing the light extraction surface but formed on the side surface of the waveguide, part of the light incident from the light emitting element into the waveguide propagates to the surface facing the light extraction surface, The light is emitted as invalid light from the facing surface into the air. For this reason, since the ineffective light is used as effective light by making the light extraction surface into a reflection surface in a waveguide with good symmetry, efficient light propagation is realized. Also, by making the surface facing this light extraction surface not a simple reflection surface, but a surface that is not perpendicular to the waveguide, a reflection surface utilizing total reflection with little light loss can be formed, Efficient light propagation is achieved. In particular, by designing the angle of the light extraction surface, this surface can also be used as a light angle conversion structure, and more efficient light propagation can be easily realized.

  Hereinafter, the organic electroluminescence element of the present invention will be described in detail.

  First, the substrate will be described. The substrate of the organic electroluminescence device of the present invention can be transparent or opaque, and any substrate can be used. When light is extracted from the substrate side, a transparent substrate is used. Otherwise, any substrate is appropriately selected and used. be able to. The substrate may be strong enough to hold the organic electroluminescence element, and the substrate of the organic electroluminescence element can also be used as a support for the driver IC.

  The substrate includes, for example, a material used for a waveguide such as transparent or translucent soda-lime glass, or a semiconductor material such as opaque silicon, germanium, silicon carbide, gallium arsenide, or gallium nitride, or a pigment. The transparent substrate material, a metal material whose surface is insulated, and the like can be appropriately selected and used, and a laminated substrate in which a plurality of substrate materials are laminated can also be used. Further, a circuit composed of a resistor, a conductor, an inductor, a diode, a transistor, and the like for driving the organic electroluminescence element may be formed on the substrate surface or inside the substrate.

  Next, the waveguide will be described.

  The waveguide is composed of a transparent core and a clad having a refractive index smaller than that of the core around the core, and the clad can substitute for an air layer, or can be composed of only the core.

Materials used for the waveguide include transparent or translucent soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz glass, inorganic oxide glass, inorganic Inorganic glass such as fluoride glass, or transparent or translucent polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyether sulfone, polyvinyl fluoride, polypropylene, polyethylene, polyacrylate, amorphous polyolefin, fluororesin, poly Polymer materials such as siloxane and polysilane, or transparent or translucent chalcogenoid glass such as As ₂ S ₃ , As ₄₀ S ₁₀ , S ₄₀ Ge ₁₀ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ , SiO , Si ₃ N _4, Hf _2, TiO ₂ or the like of the metal oxide and can be suitably selected from materials such as nitrides, or a photosensitive material such as a resist may be used in bleaching. Furthermore, in order to make the refractive index of the waveguide close to the refractive index of the light emitting layer, the waveguide can be formed using the same material as the light emitting layer material.

  In the present invention, the definition of transparent or translucent indicates transparency to the extent that the visual recognition of light emission by the organic electroluminescence element is not hindered.

  In addition, the light angle conversion structure is a structure in which, when incident light reaches the interface at the interface between two different media, it is reflected at an angle different from the incident angle with respect to the interface. Surfaces and structures that are not parallel to any of the surfaces.

  Specific examples include a surface that is non-parallel and non-perpendicular to the interface. For example, a triangular prism, a cylinder, a triangular pyramid, a cone, or a complex in which these are arranged three-dimensionally or two-dimensionally, It is a structure composed of a scattering surface, etc., and is composed of waveguide curvature, waveguide surface irregularities, microlenses, microprisms, micromirror structures, and aggregates thereof.

  The angle conversion structure of light can be formed either on the surface of the waveguide or on the inside of the waveguide.

  When the angle conversion structure of light is formed on the surface of the waveguide, the surface of the waveguide can be polished to form irregularities, and can be realized by forming a clad or a light emitting element on the irregularities. Alternatively, it can be realized by bonding a microlens or the like to the surface of the waveguide. When the angle conversion structure of light is formed on the surface of the waveguide, the interface may be an air / substrate interface. Is used as a cladding layer. Thus, when the angle conversion structure of light is formed on the surface of the waveguide, the surface may be processed after the formation of the organic electroluminescence element, and the formation process is simple, so that it can be easily formed.

  Also, when the light angle conversion structure is formed inside the waveguide, the light angle conversion structure can be formed by embedding irregularities or microlenses in the waveguide, and in the core or cladding, or at the core / cladding interface. Can be formed. When it is formed at the core / cladding interface, it can be realized by forming irregularities on the surface of the core by polishing, blasting, etching or the like and forming a cladding layer on the surface. In such a structure, the light angle conversion structure is not exposed, stable light angle conversion is performed, and the waveguide surface can be flattened, so that an anode or the like is easily formed on the waveguide. be able to.

  The anode is an electrode for injecting holes, and it is necessary to efficiently inject holes into the light emitting layer or the hole transport layer.

A transparent electrode can be used as the anode. As a material for the transparent electrode, metal oxides such as indium tin oxide (ITO), tin oxide (SnO ₂ ), and zinc oxide (ZnO), or SnO: Sb (antimony), ZnO: Al (aluminum), IZO A transparent conductive film made of a mixture of (In ₂ O ₃ : ZnO), or Al (aluminum), Cu (copper), Ti (titanium), Ag (silver), Au (thickness not to impair transparency) It is possible to use a metal thin film such as gold), a mixed thin film of these metals, a metal thin film such as a laminated thin film, or a conductive polymer such as polypyrrole. Moreover, it can also be set as a transparent electrode by laminating | stacking several said transparent electrode material, It forms by various polymerization methods, such as resistance heating vapor deposition, electron beam vapor deposition, a sputtering method, or an electric field polymerization method. Further, it is desirable that the transparent electrode has a thickness of 1 nm or more in order to provide sufficient conductivity or to prevent uneven light emission due to unevenness on the substrate surface. In addition, it is desirable that the thickness be 500 nm or less in order to provide sufficient transparency.

Furthermore, as the anode, besides the transparent electrode, a metal having a large work function such as Cr (chromium), Ni (nickel), Cu (copper), Sn (tin), W (tungsten), Au (gold), Alternatively, an alloy, oxide, or the like can be used, and a laminated structure of a plurality of materials using these anode materials can also be used. However, when a transparent electrode is not used as the anode, the anode is preferably formed of a material that reflects light in order to make the most of the effect of the light angle conversion means. In addition, when not using a transparent electrode as an anode, a cathode should just be a transparent electrode.

Further, an amorphous carbon film may be provided on the anode. In this case, both have a function as a hole injection electrode. That is, holes are injected from the anode into the light emitting layer or the hole transport layer through the amorphous carbon film. The amorphous carbon film is formed by sputtering between the anode and the light emitting layer or the hole transport layer. Examples of the carbon target by sputtering include isotropic graphite, anisotropic graphite, glassy carbon, and the like. Although not particularly limited, isotropic graphite having high purity is suitable. Specifically, when the work function of the amorphous carbon film is measured using a surface analyzer AC-1 manufactured by Riken Keiki, the work of the amorphous carbon film is shown. The function is W _c = 5.40 eV. Here, the work function of ITO, which is generally used as an anode, is W _ITO = 5.05 eV. Therefore, the use of an amorphous carbon film efficiently generates holes in the light emitting layer or the hole transport layer. Can be injected. Further, when the amorphous carbon film is formed by sputtering, reactive sputtering is performed in an atmosphere of nitrogen or a mixed gas of hydrogen and argon in order to control the electric resistance value of the amorphous carbon film. Furthermore, in the thin film formation technique by sputtering or the like, when the film thickness is 5 nm or less, the film becomes an island structure and a uniform film cannot be obtained. For this reason, when the film thickness of the amorphous carbon film is 5 nm or less, efficient light emission cannot be obtained, and the effect of the amorphous carbon film cannot be expected. Further, when the film thickness of the amorphous carbon film is 200 nm or more, the color of the film becomes dark and light emitted from the organic electroluminescence element cannot be sufficiently transmitted.

Here, as the light-emitting layer has a fluorescence characteristic in the visible region, and is preferably made of a film-forming properties good phosphor, in addition to Alq ₃ and Be- benzoquinolinol (BeBq _2), 2,5- Bis (5,7-di-t-pentyl-2-benzoxazolyl) -1,3,4-thiadiazole, 4,4′-bis (5,7-benzyl-2-benzoxazolyl) stilbene, 4,4′-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] stilbene, 2,5-bis (5,7-di-t-benzyl-2- Benzoxazolyl) thiophine, 2,5-bis ([5-α, α-dimethylbenzyl] -2-benzoxazolyl) thiophene, 2,5-bis [5,7-di- (2-methyl-) 2-butyl) -2-benzoxazolyl] -3,4-diphenylthio 2,5-bis (5-methyl-2-benzoxazolyl) thiophene, 4,4′-bis (2-benzoxazolyl) biphenyl, 5-methyl-2- [2- [4- Benzoxazoles such as (5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazolyl, 2- [2- (4-chlorophenyl) vinyl] naphtho [1,2-d] oxazole, 2, Benzothiazoles such as 2 '-(p-phenylenedivinylene) -bisbenzothiazole, 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole, 2- [2- (4-carboxyphenyl) ) Vinyl] benzimidazole and other fluorescent brighteners, bis (8-quinolinol) magnesium, bis (benzo-8-quinolinol) Bis (2-methyl-8-quinolinolate) aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-quinolinol lithium, tris (5-chloro-8-quinolinol) gallium Metal chelates such as 8-hydroxyquinoline-based metal complexes such as bis (5-chloro-8-quinolinol) calcium and poly [zinc-bis (8-hydroxy-5-quinolinonyl) methane] and dilithium ependridione Oxinoid compounds, 1,4-bis (2-methylstyryl) benzene, 1,4- (3-methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, distyrylbenzene, 1,4- Bis (2-ethylstyryl) benzene, 1,4-bis (3-ethylstyryl) Styrene, 1,4-bis (2-methylstyryl) 2-methylbenzene and other styrylbenzene compounds, 2,5-bis (4-methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine 2,5-bis [2- (1-naphthyl) vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2,5-bis [2- (4-biphenyl) vinyl] pyrazine, 2, Distylpyrazine derivatives such as 5-bis [2- (1-pyrenyl) vinyl] pyrazine, naphthalimide derivatives, perylene derivatives, oxadiazole derivatives, aldazine derivatives, cyclopentadiene derivatives, styrylamine derivatives, Coumarin derivatives and aromatic dimethylidin derivatives are used. Furthermore, anthracene, salicylate, pyrene, coronene and the like are also used. Alternatively, a phosphorescent material such as fac-tris (2-phenylpyridine) iridium, or a polymer light emitting material such as PPV (polyparaphenylene vinylene) or polyfluorene may be used.

  In addition to the single-layer structure of only the light-emitting layer, any of a two-layer structure of a hole transport layer and a light-emitting layer or a light-emitting layer and an electron transport layer, or a three-layer structure of a hole transport layer, a light-emitting layer, and an electron transport layer The structure of may be sufficient. However, in the case of such a two-layer structure or a three-layer structure, the hole transport layer and the anode are stacked or the electron transport layer and the cathode are in contact with each other. Alternatively, a structure in which an electron blocking layer is provided between the hole transport layer and the light emitting layer, a structure in which a hole blocking layer is provided between the light emitting layer and the electron transport layer, or an anode and a hole transport layer Even in a multi-layer structure in which a functionally separated layer is appropriately selected and laminated or mixed, such as a structure in which a hole injection layer is provided between the layers and a structure in which an electron injection layer is provided between the electron injection layer and the cathode Good.

  And as a positive hole transport layer, a hole mobility is high, and a transparent and favorable film forming property is preferable. In addition to TPD, porphyrin compounds such as porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, 1,1-bis {4- (di-P-tolylamino) phenyl} cyclohexane, 4,4 ′, 4 ″ -trimethyltriphenylamine, N, N, N ′, N′-tetrakis (P-tolyl) -P-phenylenediamine, 1- (N, N-di-P-tolylamino) naphthalene, 4,4 ′ -Bis (dimethylamino) -2-2'-dimethyltriphenylmethane, N, N, N ', N'-tetraphenyl-4,4'-diaminobiphenyl, N, N'-diphenyl-N, N'- Di-m-tolyl-4, N, N-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-4,4′-diamine, 4′- Aromatic tertiary amines such as aminobiphenyl and N-phenylcarbazole, 4-di-P-tolylaminostilbene, 4- (di-P-tolylamino) -4 ′-[4- (di-P-tolylamino) Styryl] stilbene and other stilbene compounds, triazole derivatives, oxazizazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, annealed amine derivatives, amino-substituted chalcone derivatives, Oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, polysilane aniline copolymers, polymer oligomers, styrylamine compounds, aromatic dimethylidin compounds, poly-3 − Organic materials such as chill thiophene is used. Further, a polymer-dispersed hole transport layer in which an organic material for a low-molecular hole transport layer is dispersed in a polymer such as polycarbonate is also used. These hole transport materials can also be used as a hole injection material or an electron block material.

  As the electron transport layer, oxadiazole derivatives such as 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7), anthraquinodimethane derivatives, diphenylquinone Derivatives, or PEDOT (polyethylenedioxythiophene), BAlq, BCP (basofproin) and the like are used. These electron transport materials can also be used as an electron injection material or a hole blocking material.

Here, the cathode is an electrode for injecting electrons, and it is necessary to efficiently inject electrons into the light-emitting layer or the electron transport layer, and Al (aluminum), In (indium), Mg ( Metals such as magnesium), Ti (titanium), Ag (silver), Ca (calcium), and Sr (strontium), or oxides or fluorides of these metals, alloys thereof, and laminates are generally used. The light that has once reached the light / air interface and has not been taken out into the air due to Fresnel reflection or the like propagates again into the device and reaches the cathode. Alternatively, since light is emitted isotropically in the light emitting layer, half of the light emitted from the light emitting layer reaches the cathode before reaching the light extraction surface. At this time, if the cathode is made of a material that reflects light, the light that reaches the cathode is reflected and can propagate again in the direction of the light extraction surface, which can be used as effective light. There is. In order to make this effect effective, the cathode is preferably formed of a material that reflects light, and the light reflectance is preferably 50% or more. The above applies to the anode when the cathode is used as a transparent electrode.

In addition, as the cathode, an ultra-thin film using a metal having a low work function is formed at the interface in contact with the light emitting layer or the electron transport layer, and a transparent electrode is laminated on the upper surface to form a transparent cathode. It can also be formed. In particular, Mg, Mg—Ag alloy, Al—Li alloy, Sr—Mg alloy, Al—Sr alloy, Al—Ba alloy or the like having a small work function or a laminated structure such as LiO ₂ / Al or LiF / Al is suitable as a cathode material. It is.

  Furthermore, resistance heating vapor deposition, electron beam vapor deposition, and sputtering are used as a method for forming these cathodes.

  Note that at least one of the anode and the cathode may be a transparent electrode. Furthermore, both may be transparent electrodes, but in order to improve the light extraction efficiency, if one is a transparent electrode, it is preferable that the other be formed of a material that reflects light.

In addition, a protective film may be formed on the surface of the element in order to block the organic electroluminescence element from the outside air and ensure long-term stability. As a material for the protective film, a thin film made of inorganic oxide, inorganic nitride, inorganic fluoride such as SiON, SiO, SiN, SiO ₂ , Al ₂ O ₃ , LiF, or inorganic oxide, inorganic nitride, inorganic Examples include glass films made of fluoride, etc., or mixtures thereof, thermosetting and photo-curing resins, and silane-based polymer materials that have a sealing effect. It is formed.

  Embodiments of the present invention will be described below.

(Embodiment 2)
Next, an exposure apparatus according to Embodiment 2 of the present invention will be described.

  FIG. 5 is an explanatory view showing in detail the exposure unit in the second embodiment of the present invention, and FIG. 6 is a cross-sectional view showing a main part in detail showing the waveguide and light source of the exposure apparatus in the exposure unit of FIG.

  5 and 6, the anode 11, the hole transport layer 14, the light emitting layer 10, the cathode 9, the core 12, and the clad 13 are the same as those described in the first embodiment and the prior art. Therefore, the same reference numerals are given and description thereof is omitted.

In an exposure apparatus using a waveguide, light from the light source propagates through the core portion of the waveguide. Therefore, the exposure light quantity can be increased by enlarging the core portion and enlarging the light emitting portion. However, when the waveguides are arranged in a planar shape, it is difficult to increase the amount of light sufficiently because the cores cannot be arranged more densely than the waveguide pitch. In addition, when the core is sufficiently large with respect to the waveguide pitch, the cladding becomes smaller as the core becomes larger, so that the cladding performs its function by oozing light from the cladding to the adjacent core. There is a problem that the waveguide cannot be manufactured because it is lost or the processing of the clad portion becomes difficult. In particular, in an exposure apparatus that performs high-quality exposure, the pitch of the waveguide is very small, so even if the cladding layer has a minimum thickness that does not allow light to ooze out, the thickness is the thickness of the core. Therefore, it is difficult to enlarge the core so that the amount of exposure light is sufficiently increased. Therefore, a waveguide having a large core portion can be easily realized and the amount of exposure light can be increased by making the waveguide a structure composed of two or more stages of waveguides.

  As shown in FIG. 6, the light source using the waveguide according to the second embodiment is composed of a two-stage waveguide having the same pitch and phase, and is independently provided in the core 12 portion of the waveguide. The anode 11 is disposed, and the hole transport layer 14, the light emitting layer 10, and the cathode 9 are uniformly formed thereon. With such a structure, by applying an independent current to the anode 11 in the light source, the light emission of each light emitting layer 10 can be easily driven independently, and any exposure light is easily emitted. Can be made.

  In addition, since the exposure apparatus of the present invention is composed of two independent waveguides and a light source that can be driven independently, any exposure can be easily obtained. When using an element having a problem in light emission amount, element lifetime, or the like as an organic electroluminescence element as a light source, or when performing high-speed printing using an element that can obtain a sufficient amount of light by conventional printing as a light source, one step The first and second stages emit light simultaneously to increase the amount of light, or the same exposure portion is sequentially shifted in the first and second stages in accordance with the movement of the exposure target to perform exposure control. A large amount of light can be exposed without intensifying the light emitted from the waveguide and the light source. Alternatively, when rough printing such as simple printing is performed, printing can be performed by an exposure method such that one of the light sources in two stages emits light or only an arbitrary light source emits light. Further, it is possible to perform driving such as improving the life of the light source by changing the level of light emission based on the indicators such as the number of times of lighting and the number of printed sheets.

  In addition, when the light source is formed on two opposite surfaces of the waveguide as shown in FIG. 6, the light source can be formed on the two surfaces using the waveguide as a substrate, but it is easy to handle when forming the exposure apparatus. In view of the above, it is preferable to include a so-called top emission type light source in which at least the electrode facing the substrate is a transparent electrode. With such a configuration, the light source can be easily formed on the two opposing surfaces of the waveguide.

  As described above, according to the second embodiment, a waveguide having a large core portion can be easily realized by using a waveguide composed of two or more stages of waveguides. A bright exposure apparatus compatible with printing or an arbitrary exposure method can be realized.

  Needless to say, the exposure apparatus according to the second embodiment can be used as an exposure apparatus for an image forming apparatus such as a printer or a copying machine.

  Here, a case where a light shielding layer is formed in the exposure apparatus according to the second embodiment will be described. 7, 8, and 9 are principal part cross-sectional views showing in detail the waveguide, light source, and light shielding layer of the exposure apparatus using the waveguide according to Embodiment 2 of the present invention. 7, 8, and 9, reference numeral 19 denotes a light shielding layer.

  As shown in FIG. 7, by providing the light shielding layer 19 between the adjacent waveguides, it is possible to obtain exposure light that is satisfactorily independent between the adjacent waveguides. With such a configuration, light does not enter from the adjacent waveguides, so that there is no variation in the amount of light extracted from the light extraction surface between the waveguides.

Unlike the case shown in FIGS. 3 and 4 described in the first embodiment, in the case where the light emitting layer 10 is not disposed between adjacent stages as shown in FIG. 7 in the second embodiment, It is preferable to provide a light shielding layer 19 between adjacent steps. Further, when forming the waveguide, the light shielding layer 19 can be formed by an easy method such as forming a layered light shielding layer 19 between adjacent steps. Then, by forming the light shielding layer 19, it is possible to obtain exposure light that is satisfactorily independent between adjacent waveguides.

  The light shielding layer 19 may be a reflective layer having a function of reflecting light. In particular, when a reflective layer is provided, light that is incident on another waveguide in the adjacent stage and propagates as invalid light propagates as effective light, and thus is more efficiently guided to the light extraction surface. It has the effect that it is possible to further increase the amount of light.

  Further, as shown in FIG. 8, in order to obtain exposure light that is well independent between the waveguides in the same stage, the light shielding layer 19 (or the reflection layer) is provided between the adjacent waveguides. Layer) is preferably provided. With such a configuration, light does not enter from other adjacent waveguides, so that there is no variation in the amount of light extracted from the light extraction surface between the waveguides.

  In particular, when a reflective layer is provided, light that is incident on another waveguide and propagates as invalid light propagates as effective light, and thus is more efficiently guided to the light extraction surface. It has the effect that it becomes possible to aim at the increase.

  Then, the light shielding layer 19 (or the reflective layer) can be formed by an easy method such as forming the light shielding layer 19 (or the reflective layer) between the waveguides adjacent to each other when the waveguide is formed. Alternatively, it is possible to obtain well-exposed exposure light between waveguides adjacent to each other by forming a reflective layer.

  Furthermore, as shown in FIG. 9, by providing a light shielding layer 19 (or a reflective layer) between adjacent waveguides and between adjacent waveguides, between adjacent waveguides, In addition, it is possible to obtain exposure light that is well independent between waveguides adjacent to each other. In this case, the clad 13 may be made to function as the light shielding layer 19 (or the reflective layer). With such a configuration, light may enter from the waveguides adjacent to the adjacent stages. And there is no variation in the amount of light extracted from the light extraction surface between the waveguides.

(Embodiment 3)
An exposure apparatus according to Embodiment 3 of the present invention will be described.

  FIG. 10 is a cross-sectional view of an essential part showing in detail the waveguide and light source of the exposure apparatus using the waveguide according to Embodiment 3 of the present invention.

  In FIG. 10, the anode 11, the hole transport layer 14, the light emitting layer 10, the cathode 9, the core 12, and the clad 13 are the same as those described in the first embodiment and the prior art, so The description is omitted.

  As shown in FIG. 10, in the light source using the waveguide in the third embodiment, the waveguides arranged in adjacent stages have the same waveguide pitch, and the waveguide phases in different stages are guided. It is composed of a two-stage waveguide that is shifted by a half of the waveguide pitch, and an independent anode 11 is disposed in the core 12 portion of the waveguide, on which a hole transport layer 14 and light emission are formed. The layer 10 and the cathode 9 are formed uniformly. With such a structure, by applying an independent current to the anode 11 in the light source, the light emission of each light emitting layer 10 can be easily driven independently, and any exposure light is easily emitted. Can be made.

  Here, in the third embodiment, since it is constituted by two-stage waveguides, the phase shift is a half equal to the value obtained by dividing the pitch by 2 which is an integer equal to or less than the number of stages. Note that dividing by 1 indicates that there is no phase shift, and the state shown in Embodiments 1 and 2 is obtained. In addition, in the case of a plurality of stages of three or more stages, for example, in the case of three stages, the phase shift may be 1/3 or 1/2, but the preferred phase shift is an integer whose pitch is equal to the number of stages. One third of the value divided by.

  When the phase of the waveguides at such different stages is shifted by a half of the waveguide pitch, the diameter of the minimum exposure light is the same as the core diameter. High-definition exposure light having a half of the waveguide pitch can be realized. For this reason, in a configuration in which the waveguide pitch is the same and the phase is shifted by a half of the pitch, high-definition exposure light that is twice the waveguide pitch can be easily realized. In particular, when considering the application of an exposure device of an image forming apparatus such as a printer, the latent image formed by the exposure light is developed as a visible image with toner having the same size as the spot image of the exposure light. Or, since the minimum line width required for the printed material and the spot image of the exposure light are sufficiently large, the diameter of the minimum exposure light is hardly a problem, and the resolution is higher than the waveguide pitch. A latent image can be formed.

  In addition, since the exposure apparatus of the present invention realizes a high-definition latent image by shifting the phase of two different stages of waveguides, compared with a latent image formed by one stage of waveguide, The amount of light per pixel can be reduced. Therefore, it is possible to realize an exposure apparatus with a large amount of light that can be easily printed at high speed, and because the core part can be made smaller than in the case of a single stage, the cladding part can be enlarged, and the waveguide and light source Easy to manufacture.

  As described above, according to the third embodiment, a waveguide having a large core portion can be easily realized by making the waveguide a structure including two or more stages of waveguides. A bright exposure apparatus compatible with printing or an arbitrary exposure method can be realized.

  Needless to say, the exposure apparatus according to the third embodiment can be used as an exposure apparatus for an image forming apparatus such as a printer or a copying machine.

(Embodiment 4)
An exposure apparatus according to Embodiment 4 of the present invention will be described.

  FIG. 11 is a fragmentary cross-sectional view showing in detail the waveguide and light source of the exposure apparatus using the waveguide according to the fourth embodiment of the present invention.

  In FIG. 11, the anode 11, the hole transport layer 14, the light emitting layer 10, the cathode 9, the core 12, and the clad 13 are the same as those described in the first embodiment and the prior art, and therefore the same reference numerals are used. The description is omitted.

As described above, in the exposure apparatus using the waveguide, light from the light source propagates through the core portion of the waveguide. Therefore, the exposure light quantity can be increased by increasing the core portion and increasing the light emitting portion. At this time, since the exposure apparatus for realizing high-definition printing is composed of pixels with a minute pitch, when the waveguide pitch is densely arranged, the light source pitch must be densely arranged as well. However, there arises a problem that it is difficult to align the light source and the waveguide. In addition, in order to drive each light source independently, it is necessary to insulate between adjacent light sources, but when the light source pitch is dense, the space between adjacent anodes must be increased in order to provide sufficient insulation. Therefore, there is a problem that the light emitting portion becomes small. For this reason, an electrode for emitting light from the light source must have a narrow space between adjacent electrodes, so that it is difficult to produce a pixel with a large light emitting portion and a small pitch, particularly as an exposure device for a printer head. It is very difficult to produce a light source with a high yield in a large area.

  As shown in FIG. 11, the light source using the waveguide in the fourth embodiment (the light emitting layer 10 disposed between the independent anode 11 and the cathode 9) has a light source on two opposing surfaces of the waveguide. The pitch of the light source can be doubled compared to the pitch of the waveguide. At this time, in particular, since the non-light emitting portion of the light source can be widened, the space between the adjacent anodes 11 can be sufficiently widened, and the light emission of each light emitting layer 10 can be easily driven independently. A high-definition light source can be formed. In particular, it is a very useful configuration for producing a light source with a high yield in a wide area such as an exposure device for a printer head.

  Further, in such a configuration, since there is a margin in the non-light emitting portion, the light emitting portion can be easily formed larger, and the position of the waveguide and the light source can be increased by making the light emitting portion larger than the core portion of the waveguide. It is possible to realize an exposure apparatus using a waveguide that can take an alignment margin and can be easily aligned.

(Embodiment 5)
An exposure apparatus according to Embodiment 5 of the present invention will be described.

  FIG. 12 is a cross-sectional view of an essential part showing in detail the waveguide and light source of the exposure apparatus using the waveguide according to the fifth embodiment of the present invention.

  In FIG. 12, the anode 11, the hole transport layer 14, the light emitting layer 10, the cathode 9, the core 12, and the clad 13 are the same as those described in the first embodiment and the prior art, so The description is omitted.

  As shown in FIG. 12, the light source using the waveguide according to the fifth embodiment is composed of two-stage waveguides in which the light source is formed on two opposing surfaces of the waveguide and the pitch and phase are the same. In the waveguide core 12, individual anodes 11 are arranged, and a hole transport layer 14, a light emitting layer 10, and a cathode 9 are uniformly formed thereon. . With this configuration, the pitch of the light source can be doubled compared to the waveguide pitch, and high-definition exposure light that is twice as high as the waveguide pitch can be emitted. . With such a configuration, the light source unit and the waveguide can be easily manufactured, and a high-definition light source that can independently drive the light emission of each light emitting layer 10 can be formed. In particular, it is a very useful configuration for producing a light source with a high yield in a wide area such as an exposure device for a printer head.

  Further, in such a configuration, since there is a margin in the non-light emitting portion, the light emitting portion can be easily formed larger, and the position of the waveguide and the light source can be increased by making the light emitting portion larger than the core portion of the waveguide. It is possible to realize an exposure apparatus using a waveguide that can take an alignment margin and can be easily aligned.

  Needless to say, the exposure apparatus according to the fifth embodiment can be used as an exposure apparatus for an image forming apparatus such as a printer or a copying machine.

(Embodiment 6)
An exposure apparatus according to Embodiment 6 of the present invention will be described.

  FIG. 13 is a cross-sectional view of the principal part showing in detail the waveguide and light source of the exposure apparatus using the waveguide according to Embodiment 6 of the present invention.

  In FIG. 13, the anode 11, the hole transport layer 14, the light emitting layer 10, the cathode 9, the core 12, the cladding 13, and the substrate 15 are the same as those described in the first embodiment and the conventional technique. The same reference numerals are given and description thereof is omitted. Reference numeral 16 denotes an adhesive.

  As shown in FIG. 13, in the light source using the waveguide in the sixth embodiment, a single-stage light source is formed on the waveguide formed on the substrate 15, and the adhesive 16 is used on the surface of the light source. A light source using a two-stage waveguide is formed by bonding light sources of various shapes. A light source can be formed on the surface of a two-stage waveguide by forming a light source on both sides of the two-stage waveguide as a substrate. It must be thinned, and the waveguide portion cannot hold the light source and cannot function as a substrate. Further, when a top emission type light source is used, it is necessary to use different processes between the upper stage and the lower stage in order to form the light source, which is not preferable. Therefore, by making two-stage light sources separately and bonding them, an exposure apparatus using a two-stage waveguide can be easily realized without devising a production process for each stage of the light source. .

  Needless to say, the exposure apparatus according to the sixth embodiment can be used as an exposure apparatus for an image forming apparatus such as a printer or a copying machine.

(Embodiment 7)
An exposure apparatus according to Embodiment 7 of the present invention will be described.

  FIG. 14 is a cross-sectional view of the main part in the longitudinal direction of the waveguide showing in detail the positional relationship between the waveguide of the exposure apparatus using the waveguide according to Embodiment 7 of the present invention, the light source, and the driver IC for driving them. is there.

  In FIG. 14, the anode 11, the hole transport layer 14, the light emitting layer 10, the cathode 9, the core 12, and the clad 13 are the same as those described in the first embodiment and the prior art, and therefore the same reference numerals are used. The description is omitted. Reference numeral 17 denotes a wiring electrode, and 18 denotes a driver IC.

  As shown in FIG. 14, the light source on the waveguide and the driver IC 18 are electrically connected via the wiring electrode 17. At this time, since a light source is formed on the waveguide, a step is generated between the light source and the driver IC 18. Therefore, by forming a taper on the surface of the waveguide that faces the light extraction surface, it is possible to perform wiring with a low possibility of disconnection. In addition, since light reaching the surface of the waveguide facing the light extraction surface becomes invalid light, there is no problem even if a taper is formed on this surface. Therefore, an exposure apparatus using a two-stage waveguide that can be easily driven independently by forming a taper on the surface opposite to the light extraction surface of the waveguide as in the seventh embodiment. Can be realized.

  In the waveguide formed with a taper, the wiring electrode 17 can be shortened and a light source can also be formed in the tapered portion. However, in this case, the size of the light source formed on the upper surface and the lower surface of the waveguide is different. This is not preferable because a difference in the amount of light occurs between the upper and lower stages. Furthermore, since the angle of light incident on the waveguide from the light source is different, this effect also causes a difference in the amount of light between the upper and lower stages. Therefore, it is preferable that no light source be formed in the tapered portion of the waveguide. .

  In FIG. 14, the light source formed on the waveguide is formed on two opposing surfaces of the waveguide. By adopting such a configuration, the pitch of the light source can be made sufficiently larger than the waveguide pitch, so that it is possible to easily realize an exposure apparatus in which the light source is formed on the waveguide.

A transparent SiON film having a film thickness of 10 μm is formed on one surface by a sputtering method on a transparent substrate made of quartz with a low-temperature sputtering apparatus depressurized to a vacuum degree of 2 × 10 ⁻⁶ Torr or less, and further in an oxygen atmosphere. An ITO film was formed to 10 μm. A resist material (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the ITO film by a spin coating method to form a resist film having a thickness of 3 μm, and the resist film is patterned into a predetermined shape by masking, exposing and developing. Then, a waveguide on which ITO was formed was formed on the core surface.

  Next, this waveguide substrate was cleaned in the order of cleaning with a detergent (manufactured by Furuuchi Chemical Co., Semico Clean), cleaning with pure water, and cleaning with pure water at 50 ° C., and then moisture adhering to the substrate with a nitrogen blower was removed. Removed and further heated to dry.

Next, TPD having a film thickness of about 50 nm was formed as a hole transport layer on the ITO surface in a resistance heating vapor deposition apparatus reduced in pressure to 2 × 10 ⁻⁶ Torr or less.

Next, similarly, in the resistance heating vapor deposition apparatus, Alq ₃ having a film thickness of about 60 nm was formed on the hole transport layer as a light emitting layer. The vapor deposition rates of TPD and Alq ₃ were both 0.2 nm / s.

Next, a SiON film having a thickness of 0.5 μm was formed on the light emitting layer in a low damage sputtering apparatus that was similarly decompressed to a vacuum of 2 × 10 ⁻⁶ Torr or less.

  Next, an adhesive made of an epoxy resin having a thickness of 1 μm is applied by spin coating onto a substrate having organic electroluminescence elements formed on the surfaces of two waveguides produced in the same manner. The layers were aligned and pasted so that the phase of each of them was shifted by a half of the waveguide pitch.

  Next, this element was heated to 80 ° C. to fix the two elements.

On a transparent substrate made of quartz, at a low temperature sputtering apparatus was evacuated to a vacuum degree of 2 × 10 ^-6 Torr, after forming on a surface by sputtering a transparent SiON film having a film thickness of 10 [mu] m, further in an oxygen atmosphere An ITO film was formed to 10 μm. A resist material (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the ITO film by a spin coating method to form a resist film having a thickness of 3 μm, and the resist film is patterned into a predetermined shape by masking, exposing and developing. Then, a waveguide on which ITO was formed was formed on the core surface.

  Next, this waveguide substrate was cleaned in the order of cleaning with a detergent (manufactured by Furuuchi Chemical Co., Semico Clean), cleaning with pure water, and cleaning with pure water at 50 ° C., and then moisture adhering to the substrate with a nitrogen blower was removed. Removed and further heated to dry.

Next, TPD having a film thickness of about 50 nm was formed as a hole transport layer on the ITO surface in a resistance heating vapor deposition apparatus reduced in pressure to 2 × 10 ⁻⁶ Torr or less.

Next, similarly, in the resistance heating vapor deposition apparatus, Alq ₃ having a film thickness of about 60 nm was formed on the hole transport layer as a light emitting layer. The vapor deposition rates of TPD and Alq ₃ were both 0.2 nm / s.

Next, a SiON film having a thickness of 0.5 μm was formed on the light emitting layer in a low damage sputtering apparatus that was similarly decompressed to a vacuum of 2 × 10 ⁻⁶ Torr or less.

  Next, an epoxy resin having a thickness of 15 μm was applied on the device by spin coating, and heated to 100 ° C. to form a clad layer.

  Next, a resist material is applied to the surface of the clad layer by spin coating to form a resist film having a thickness of 3 μm. The mask is exposed, developed, and the core is positioned at a position where the phase is shifted by a half of the waveguide pitch. A resist mask to be formed was formed.

Next, the resist mask-clad surface is etched to a depth of 10 μm by a reactive ion etching method, and then is transparent with a film thickness of 10 μm using a low-temperature sputtering apparatus whose pressure is reduced to a vacuum of 2 × 10 ⁻⁶ Torr or less. After forming a simple SiO ₂ film and ITO film on one surface by sputtering, the resist was peeled off to obtain an element in which a two-stage waveguide was formed.

Next, TPD having a film thickness of about 50 nm was formed as a hole transport layer on the ITO surface in a resistance heating vapor deposition apparatus reduced in pressure to 2 × 10 ⁻⁶ Torr or less.

Next, similarly, in the resistance heating vapor deposition apparatus, Alq ₃ having a film thickness of about 60 nm was formed on the hole transport layer as a light emitting layer. The vapor deposition rates of TPD and Alq ₃ were both 0.2 nm / s.

Next, a SiON film having a thickness of 0.5 μm was formed on the light emitting layer in a low damage sputtering apparatus that was similarly decompressed to a vacuum of 2 × 10 ⁻⁶ Torr or less.

(Comparative example)
An ITO film having a thickness of 160 nm is formed on a transparent substrate made of glass, and then a resist material is applied onto the ITO film by a spin coating method to form a resist film having a thickness of 10 μm. Was etched to form an anode having a width of 10 μm.

  Next, a resist film is applied to the surface of the substrate on which the anode is formed to a thickness of 3 μm, and is patterned in a shape in which the resist is removed with a width of 10 μm in a direction perpendicular to the anode, and a square shape having a side of 10 μm. A patterned substrate on which an anode was formed was obtained.

  Next, this patterning substrate is subjected to ultrasonic cleaning for 5 minutes with detergent (Semico Clean, manufactured by Furuuchi Chemical Co., Ltd.), ultrasonic cleaning for 10 minutes with pure water, and aqueous hydrogen peroxide with respect to ammonia water 1 (volume ratio). After cleaning in the order of 5 minutes ultrasonic cleaning with a solution of 1 and water 5 and 5 minutes ultrasonic cleaning with 70 ° C. pure water, water attached to the substrate was removed with a nitrogen blower and further heated. And dried.

Next, this patterning substrate was washed in the same manner, and then TPD was deposited on the surface on the anode side as a hole transport layer with a thickness of about 50 nm in a resistance heating evaporation apparatus reduced in vacuum to 2 × 10 ⁻⁶ Torr or less. It was formed with a film thickness.

Next, similarly, in the resistance heating vapor deposition apparatus, Alq ₃ having a film thickness of about 60 nm was formed on the hole transport layer as a light emitting layer. The vapor deposition rates of TPD and Alq ₃ were both 0.2 nm / s.

  Next, in the same manner, in the resistance heating vapor deposition apparatus, a cathode was formed to a thickness of 150 nm using an Al—Li alloy containing 15 at% Li on the light emitting layer as a vapor deposition source.

  Here, the evaluation method and the evaluation criteria in the evaluation items of (Table 1) will be described.

  The amount of exposure light was evaluated for the amount of light emitted from the light extraction surface of the exposure apparatus. The evaluation is a three-stage evaluation of ◎, ○, △, and the evaluation criteria are ◎: very good, ◯: excellent, and △: acceptable.

Moreover, the exposure pitch evaluated about the pitch of the exposure image which can be formed using the exposure apparatus formed with the same pitch. The evaluation is a three-stage evaluation of ◎, ○, △, and the evaluation criteria are ◎: very good, ◯: excellent, and △: acceptable.
Further, the yield was evaluated with respect to the ratio at which predetermined exposure light was emitted for the exposure apparatus formed at the same pitch. The evaluation is a three-stage evaluation of ◎, ○, △, and the evaluation criteria are ◎: very good, ◯: excellent, and △: acceptable.

  The exposure apparatus and the image forming apparatus of the present invention are useful as an exposure apparatus and an image forming apparatus that are bright at a fine pitch, high speed, and high definition.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to Embodiment 1 of the present invention. Explanatory drawing which shows the exposure part in the image forming apparatus of FIG. 1 in detail The perspective view which shows the principal part of the exposure apparatus in the exposure part of FIG. FIG. 3 is a cross-sectional view of an essential part showing in detail the waveguide and light source of the exposure apparatus of FIG. Explanatory drawing which shows the exposure part in Embodiment 2 of this invention in detail FIG. 5 is a fragmentary cross-sectional view showing in detail the waveguide and light source of the exposure apparatus in the exposure unit of FIG. Sectional drawing which shows the principal part which shows in detail the waveguide of the exposure apparatus using the waveguide in Embodiment 2 of this invention, a light source, and a light shielding layer Sectional drawing which shows the principal part which shows in detail the waveguide of the exposure apparatus using the waveguide in Embodiment 2 of this invention, a light source, and a light shielding layer Sectional drawing which shows the principal part which shows in detail the waveguide of the exposure apparatus using the waveguide in Embodiment 2 of this invention, a light source, and a light shielding layer Sectional drawing which shows the principal part which shows in detail the waveguide and light source of the exposure apparatus using the waveguide in Embodiment 3 of this invention Sectional drawing which shows the principal part which shows in detail the waveguide and light source of the exposure apparatus using the waveguide in Embodiment 4 of this invention Sectional drawing which shows the principal part which shows in detail the waveguide and light source of the exposure apparatus using the waveguide in Embodiment 5 of this invention Sectional drawing which shows the principal part which shows in detail the waveguide and light source of the exposure apparatus using the waveguide in Embodiment 6 of this invention Sectional drawing of the principal part of the longitudinal direction of a waveguide which shows in detail the positional relationship of the waveguide of the exposure apparatus using the waveguide in Embodiment 7 of this invention, the light source, and the driver IC for driving these Cross-sectional view of the main part of a conventional organic electroluminescence device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exposure part 2 Photoconductor 3 Charger 4 Developer 5 Transfer device 6 Cleaner 7 Fixing device 8 Erecting equal magnification optical system 9 Cathode 10 Light emitting layer 11 Anode 12 Core 13 Cladding 14 Hole transport layer 15 Substrate 16 Adhesive 17 Wiring Electrode 18 Driver IC
19 Shading layer

Claims (19)

A waveguide composed of a core in which a plurality of optically separated pixels in the main scanning direction are arranged in parallel to each other at least for each pixel whose end surface in the sub-scanning direction is a light extraction surface; and on the waveguide A light source that can emit light in accordance with the formed input signal, and is an exposure apparatus that uses light emitted from the light source, incident on the waveguide, and emitted from the light extraction surface as exposure light. The exposure apparatus is characterized by comprising a plurality of waveguides of at least two stages. 2. The exposure apparatus according to claim 1, wherein the waveguides have substantially the same pitch and phase of waveguides arranged in adjacent stages. 2. The exposure according to claim 1, wherein the waveguides have the same pitch between the waveguides arranged in adjacent stages, and the phase shift is substantially the same as a value obtained by dividing the pitch by an integer equal to or less than the number of stages. apparatus. 2. The exposure apparatus according to claim 1, wherein the waveguides have the same pitches arranged in adjacent stages, and the phase shift is approximately one half of the pitch. The exposure apparatus according to claim 1, wherein the waveguide has a light shielding layer formed between adjacent stages. 6. The exposure apparatus according to claim 1, wherein the waveguide has a taper formed on a surface facing the light extraction surface. The exposure apparatus according to claim 6, wherein the light source is not formed in a tapered portion of the waveguide. A waveguide composed of a core in which a plurality of optically separated pixels in the main scanning direction are arranged in parallel to each other at least for each pixel whose end surface in the sub-scanning direction is a light extraction surface; and on the waveguide A light source that can emit light in accordance with the formed input signal, and is an exposure apparatus that uses light emitted from the light source, incident on the waveguide, and emitted from the light extraction surface as exposure light. The light source is formed on at least two opposing surfaces of the waveguide. 9. The exposure apparatus according to claim 8, wherein the light source includes a light source in which at least an electrode facing the substrate is a transparent electrode. The exposure apparatus according to claim 8, wherein the waveguide includes a plurality of waveguides including at least two stages. 11. The exposure according to claim 1, wherein the light source comprises an organic electroluminescence device including at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons. apparatus. 12. The exposure apparatus according to claim 1, wherein the refractive index of the core of the waveguide is larger than a value obtained by subtracting 0.3 from the refractive index of the light emitting layer. The exposure apparatus according to claim 1, wherein the waveguide is formed using the same material as the light emitting layer. 14. The exposure apparatus according to claim 1, wherein a light shielding layer or a reflective layer is provided between the waveguides adjacent to each other. 15. The exposure apparatus according to claim 1, wherein the light extraction surface has a shape corresponding to a pixel shape. The angle conversion structure for converting the angle of light incident on the waveguide from the light emitting layer and guiding the light to the light extraction surface is formed in the waveguide. The exposure apparatus described. The exposure apparatus according to claim 1, wherein the light emitted from the light extraction surface forms an image on the photosensitive member at an erecting equal magnification. An exposure apparatus according to any one of claims 1 to 17,
An image forming apparatus comprising: a photosensitive member on which an electrostatic latent image is formed by the exposure device. The image forming apparatus according to claim 18, wherein the exposure apparatus is alternately turned on at different stages.

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