JP2006167985A - Optical recording head and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To relatively freely set the arrangement, the size and the shape of openings which emit a recording light, obtain a good spot diameter by a relatively high intensity and facilitate assembly and manufacture in an optical recording head and image forming apparatus,. <P>SOLUTION: In the optical recording head 1 where a plurality of light emitting sources independently driven when a driving voltage is applied by a driving control part 19 are formed on a glass substrate 2, an ITO electrode 4, an organic EL layer 5 and an aluminum electrode 7 are layered in this order, and an optical waveguide layer is formed by the ITO electrode 4 and organic EL layer 5. The recording light which propagates in the optical waveguide layer except an opening 7a is constrained in by a reflecting layer 3a, a clad layer 3b and the aluminum electrode 7. A scattering part 6 is formed in the optical waveguide layer located at the opening 7a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical recording head and an image forming apparatus.

Conventionally, in an electrophotographic image forming apparatus such as an optical printer or a digital copying machine, an organic electroluminescence element (abbreviated as an organic EL element) is used as a recording pixel as an exposure means for forming an electrostatic latent image. A plurality of optical recording heads which are arranged in response to each other and whose lighting elements are controlled to be turned on according to an image signal for each recording pixel are known.
The organic EL element emits light in the normal direction of the light emitting layer as a surface light emitting element in a display device or the like, but since the required exposure amount of the optical printer is higher than the light amount of the display device, the pixel area There has been proposed an edge-emitting element that forms a light-emitting layer with a larger area and collects emitted light in the side surface direction in which the light-emitting layer extends to increase the light emission intensity.
For example, Patent Document 1 describes an optical recording head capable of multi-tone recording using such an edge-emitting EL element and an optical printer using the same. That is, in this EL element, a layered cross-sectional structure in which a light emitting layer is formed through an insulating layer between a metal base electrode having a good reflectance and a counter electrode extends in a band shape, and the EL element is insulated. A large number of optical recording heads are arranged in parallel at a predetermined pitch on a conductive substrate. The light generated in the light emitting layer of each EL element reaches the end in the longitudinal direction of the belt while being reflected by the insulating layer, the base electrode, or the counter electrode, and is emitted to the outside.
JP-A-2-48965 (page 5-10, FIG. 2-4)

However, the conventional optical recording head and image forming apparatus as described above have the following problems.
In the technique described in Patent Document 1, the optical recording head has a configuration in which end portions of EL elements that form emitted light are aligned with side end surfaces of an insulating substrate such as a glass substrate on which they are arranged. For this reason, a space for holding a condensing element such as a lens for condensing recording light emitted from the EL element is as narrow as the thickness of the insulating substrate, and it is difficult to directly install the condensing element. For this reason, for example, it is necessary to align and attach the two on another holding member, and there is a problem that the configuration is complicated and the manufacturing efficiency is inferior.
In addition, since the light emitting layer thickness of the EL element is extremely thin, in order to secure the light amount, the opening width in the direction perpendicular to the layer thickness must be widened. There is a problem that the image becomes too flat and a good spot diameter cannot be formed on the optical recording surface even through the light condensing element. For example, an anamorphic lens or the like may be adopted as a light condensing element, but there is a problem that providing such a special light condensing element for each pixel results in an expensive device.

  The present invention has been made in view of the above-described problems, and the arrangement, size, and shape of the aperture for emitting recording light can be set relatively freely, and it has a relatively high intensity and a good spot. It is an object of the present invention to provide an optical recording head and an image forming apparatus which can obtain a diameter and can be easily assembled and manufactured.

In order to solve the above-described problem, in the invention described in claim 1, the second electrode is disposed opposite to the first electrode set to the reference potential and applies a driving voltage in accordance with the image signal. A plurality of light emitting sources sandwiched between the first electrode and the second electrode and having a light emitting layer for generating recording light according to the driving voltage and an opening for emitting the recording light to the outside An optical recording head comprising an optical recording portion formed on the plate surface of the base substrate and in which the openings are arranged in accordance with the pixel positions of the optical recording surface in a direction along the plate surface of the base substrate, Each light emitting source is formed with an optical waveguide layer capable of propagating recording light generated by the light emitting layer in a direction perpendicular to the layer thickness direction of the light emitting layer, and the layer thickness direction of the light emitting layer of each light emitting source The visual area is set larger than the opening area of each corresponding opening, Each opening is provided at a position where the recording light propagating through the optical waveguide layer can be emitted in the thickness direction of the light emitting layer, and the emitted light from other than the opening of the recording light is disposed around the optical waveguide layer. An optical sealing means for confining in the optical waveguide layer is provided, and a scattering means for disturbing the optical path of the recording light propagating in the optical waveguide layer is provided in the optical waveguide layer positioned in the opening. .
According to this invention, recording light is generated from the light emitting layer by applying a driving voltage corresponding to the image signal to the second electrode. Since the recording light is confined in the optical waveguide layer by the optical sealing means except for the aperture, the reflection in the optical waveguide layer is repeatedly propagated in the direction perpendicular to the layer thickness direction, and the scattering means. When the light beam reaches, the optical path is disturbed, and the recording light traveling toward the opening increases, and the recording light is emitted from the opening to the outside. By repeating this, the recording light generated in the light emitting layer is emitted from the opening except for some attenuated light.
That is, since the recording light generated in an area wider than the opening is emitted to the outside from the opening in the direction perpendicular to the layer thickness direction of the light emitting layer, a large amount of light can be obtained compared to the size of the opening.
Since each light source is formed on the plate surface of the base substrate and the openings can be two-dimensionally arranged in a direction along the plate surface of the base substrate, the degree of freedom of the arrangement position of the openings is high, and the optical recording surface It becomes easy to arrange according to the pixel position. Moreover, when arrange | positioning a condensing element etc., in order to arrange | position to the front surface of opening, it can attach on a base substrate.
In addition, the opening can be set to a free shape within a range of the area of the light emitting layer without depending on the thickness of the light emitting layer, for example, a rectangle with a small difference in aspect ratio, a shape such as a circle, an ellipse, etc. It becomes easy to make the spot diameter good when condensed.

  Here, the light sealing means may be a means for reflecting light to the inside in order to confine light, or a means for confining light by bending the optical path by changing the refractive index.

According to a second aspect of the present invention, in the optical recording head of the first aspect, the scattering means is composed of a plurality of granular materials having a refractive index different from that of the optical waveguide layer.
According to the present invention, by arranging a plurality of granular materials having a refractive index different from that of the optical waveguide layer in the optical waveguide layer, when recording light is incident on the granular material, a part of the recording light is refracted and transmitted while changing the propagation direction. Others are reflected on the surface of the granular material and scattered in various directions. Then, the optical path of the recording light is disturbed.
In addition, according to such a configuration, it is only necessary to dispose the granular material in the optical waveguide layer, so that the scattering means can be easily manufactured.

According to a third aspect of the present invention, in the optical recording head according to the second aspect, the granular material is composed of a phosphor whose light is excited by the wavelength of the recording light.
According to this invention, since the granular material is constituted by the phosphor whose light is excited by the wavelength of the recording light, the recording light is scattered as the granular material, and the excitation light having a light amount corresponding to the intensity of the recording light is emitted from the phosphor. Arising from. For this reason, the amount of recording light emitted from the opening can be increased.

According to a fourth aspect of the present invention, in the optical recording head according to the first aspect, the scattering means comprises a diffraction grating.
According to the present invention, by providing the diffraction grating, the recording light is diffracted according to the wavelength of the recording light and the incident angle with respect to the diffraction grating to generate higher-order light, so that the optical path of the recording light can be disturbed. As a result, even when the 0th-order light is not emitted from the opening, the possibility that high-order light is emitted is increased, so that the recording light emitted from the opening can be increased.

According to a fifth aspect of the present invention, in the optical recording head according to the first aspect, the scattering means is at least one of the opening-side layer surface of the optical waveguide layer positioned in the opening and the bottom surface of the layer facing it. It is set as the structure which consists of unevenness | corrugation provided in.
According to the present invention, since the optical waveguide layer positioned in the opening is provided with irregularities on at least one of the surface of the opening side layer and the bottom surface of the layer facing it, the reflection and refraction of the recording light are disturbed by the irregularities, and the optical path Is scattered. For this reason, it is possible to increase the recording light transmitted from the inside toward the opening.

Here, the unevenness means including either a concave surface or a convex surface, each of which may be a smooth curved surface, or a shape such as a groove shape or a mountain shape with a sharp bottom or top. Also good.
In order to manufacture these shapes, for example, in a manufacturing process in which the optical waveguide layer is formed with a substantially constant thickness, the underlying layer on which the optical waveguide layer is formed is cut or etched to form irregularities. Can be produced. Further, for example, after forming the optical waveguide layer and before forming the opening, the surface of the optical waveguide layer can be shaved or etched to directly form irregularities.

According to a sixth aspect of the present invention, in the optical recording head according to any one of the first to fifth aspects, the light emitting layer comprises an organic EL layer, and one of the first and second electrodes is the recording light. And the other of the first and second electrodes is a light-reflecting electrode that reflects the recording light, and the light-emitting layer and one of the first and second electrodes Constitutes the optical waveguide layer, and the opening is formed in the other of the first and second electrodes.
According to this invention, even if the light emitting layer is an organic EL layer having a relatively thin layer thickness, the recording light emitted from the entire organic EL layer is formed by forming the optical waveguide layer having the layer thickness combined with the transparent electrode. Can be efficiently extracted from the opening arranged in the layer thickness direction by the scattering means.
In addition, since the member that forms the opening by the other of the light-reflective first and second electrodes and the light sealing means can be used together, a simple configuration can be achieved.

According to a seventh aspect of the present invention, in the optical recording head according to the sixth aspect, the transparent electrode has a thickness of 50 nm to 1000 nm.
According to the present invention, since the thickness of the transparent electrode becomes appropriate, the efficiency of optical waveguide can be improved and the light quantity loss can be reduced.
The thickness of the transparent electrode is more preferably narrower than the above range, and for example, the upper limit is preferably 600 nm.

In the invention described in claim 8, an electrostatic latent image is formed on a photosensitive member having a photoconductive optical recording surface by using an exposure means, and the electrostatic latent image is developed by a developing means to form a visible image. An image forming apparatus to be formed, wherein the exposure unit includes the optical recording head according to claim 1.
According to the present invention, an image forming apparatus using the optical recording head according to any one of claims 1 to 7 can be obtained. Therefore, it has the same effect as that of the invention according to any one of claims 1 to 7.

  According to the optical recording head and the image forming apparatus of the present invention, the plurality of light sources including the optical waveguide layer formed on the base substrate are arranged in the direction along the plate surface of the base substrate, and the light emitting layer is arranged in the layer thickness direction. Since an opening having a larger area than that of the light emitting layer is provided, the arrangement position, size, and shape of the opening can be set relatively freely, so that it is possible to easily obtain a good spot diameter with relatively high intensity. For example, there is an effect that assembly and manufacture are facilitated, for example, a member such as a condensing element is easily arranged on the opening side.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

[First Embodiment]
An optical recording head according to a first embodiment of the present invention will be described.
FIG. 1A is a schematic explanatory view in plan view for explaining the configuration of the main part of the optical recording head according to the first embodiment of the present invention. However, for the schematic view, the illustration of a part of the cross section such as the drive control unit 19 is omitted. FIG.1 (b) is AA sectional drawing in Fig.1 (a). FIG.1 (c) is BB sectional drawing in Fig.1 (a). FIG. 2A is a schematic explanatory view of a cross-sectional view taken along the line AA of FIG. 1A for describing the scattering means used in the optical recording head according to the first embodiment of the present invention.

In the optical recording head 1 of the present embodiment, a plurality of light emitting sources that can be independently driven to emit light corresponding to the pixels on the optical recording surface are arranged on the glass substrate 2 (base substrate), and lighting control can be performed according to an image signal. For example, it is suitable as an exposure unit of an image forming apparatus.
As shown in FIG. 1A, the schematic configuration of the optical recording head 1 includes a drive control unit 19 that performs lighting control according to an image signal or a drive control signal obtained by performing appropriate signal processing on the image signal, and drive control. A plurality of light emitting sources connected to the unit 19 includes a recording unit 17 arranged on the glass substrate 2 with an appropriate pitch.
The power supply unit 18 is for supplying a DC voltage as a drive voltage to the drive control unit 19, and may be built in the optical recording head 1 or provided outside.
The drive control unit 19 applies a drive voltage to each light emission source of the recording unit 17 and includes, for example, switching means for on / off control.

The configuration of the light source constituting the recording unit 17 will be described.
The schematic configuration of each light emitting source is as shown in FIGS. 1B and 1C, with a reflection layer 3a (light sealing means) and a cladding layer 3b on a glass substrate 2 which is an insulator substrate. (Light sealing means), ITO (Indium Tin Oxide) electrode 4 (second electrode), organic EL layer 5 (light emitting layer), aluminum electrode 7 (first electrode), sealing film 8, and scattering portion 6 (Scattering means).
As the glass substrate 2, for example, Corning 1737 manufactured by Corning Corporation can be used.

The reflection layer 3 a is a metal reflection film layer for preventing leakage light that reflects recording light generated at the upper portion and passes through the glass substrate 2, and is provided on the glass substrate 2. As the type of metal, any metal can be used as long as a necessary reflectance can be obtained. For example, chromium can be used. In that case, the film thickness is preferably about 100 nm, for example.
The clad layer 3b is a transparent film having a refractive index smaller than that of the ITO electrode 4 thereabove, and is provided to reflect recording light propagating through the ITO electrode 4. As the material of the clad layer 3b, for example, a SiO ₂ film can be adopted.
The layer thickness of the clad layer 3b is preferably 150 nm to 500 nm.

The reflective layer 3a and the clad layer 3b are provided as an optical sealing means so as to efficiently reduce the leakage light to the glass substrate 2 and to efficiently guide the recording light in the transparent electrode. However, if only one of them can sufficiently regulate the amount of light leaked to the glass substrate 2 side, only one of them may be provided.
For example, when the resistance value of the transparent electrode is high, the transparent electrode may be formed directly on the reflective layer 3a without providing the cladding layer 3b. In that case, the recording light is optically guided by being reflected by the reflective layer 3a.

The ITO electrode 4 is a transparent electrode serving as an anode made of indium tin oxide, is formed in a strip shape on the cladding layer 3 b, and is connected to the power supply unit 18 via the drive control unit 19. ing. A drive voltage can be applied to each light source in accordance with the pixel signal.
The ITO electrodes 4 of the respective light emission sources are arranged in parallel to each other with a predetermined pitch, which will be described later, in the short direction in plan view.
The refractive index of the ITO electrode 4 is about 2.1. The layer thickness of the ITO electrode 4 is preferably in the range of 50 nm to 1000 nm, and more preferably in the range of 50 nm to 600 nm. In this embodiment, the layer thickness is about 0.4 μm.

Here, the thickness range of the ITO electrode 4 will be described with reference to simulation results.
For simplicity, the case of a two-dimensional waveguide model in which the glass substrate 2, the ITO electrode 4, the organic EL layer 5, and the aluminum electrode 7 are laminated in this order will be considered. Here, the organic EL layer 5 is a buffer layer for preventing light loss due to the aluminum electrode 7. In order to simplify the calculation, the organic EL layer 5 is sufficiently thicker than the other layers. Further, the refractive indexes of the glass substrate 2, the ITO electrode 4, and the organic EL layer 5 that are the optical waveguide layers of the ITO electrode 4 are 1.5, 2.0, and 1.7, respectively.
At this time, when the eigenvalue equation for the TE mode is solved from the Maxwell equation, the thickness T of the optical waveguide layer that cuts off the light guided is obtained as follows.
T = 0.15 · (0.76 + m · π) · λ (1)
Here, λ is the wavelength of light λ, and m is the waveguide mode number.

When the thickness T in the range of the wavelength λ of 500 nm to 650 nm is calculated by the equation (1), the following table is obtained.

From Table 1, it can be seen that there is an optimum layer thickness for cutting off light for each wavelength in the range of 57 nm to 993 nm. If the wavelength range is slightly expanded from the range shown in Table 1, it can be seen that a suitable value exists in the range of 50 nm to 1000 nm.
As described above, the layer thickness of the ITO electrode 4 has an optimum value depending on the wavelength and the waveguide mode number, but the emission wavelength of the organic EL layer 5 varies, and the waveguide mode also includes various modes. Considering this, if the layer thickness is within such a range, a good optical waveguide layer can be obtained.

The organic EL layer 5 may have any layer configuration as long as it can emit light by applying a driving voltage with the ITO electrode 4 and the aluminum electrode 7. For example, TPD (tetraphenyldiamine derivative) as a hole transport material, As a fluorescent material, Alq3 (aluminato-tris-8-hydroxyquinolate, aluminum quinolinol complex) is formed on the ITO electrode 4 in this order as a two-layer structure of about 50 nm to 70 nm, and in a range overlapping with the ITO electrode 4 in plan view. An extended configuration can be employed.
In this configuration, TPD constitutes a hole transport layer, and Alq3 serves as both a light-emitting layer and an electron transport layer in a narrow sense.
Such an organic EL layer 5 can transmit recording light and has a refractive index of about 1.7.
Thus, the ITO electrode 4 and the organic EL layer 5 constitute an optical waveguide layer that propagates the recording light emitted by the organic EL layer 5.

The aluminum electrode 7 is a member that forms a light-reflective cathode provided so as to sandwich the organic EL layer 5 with the ITO electrode 4, and has the same potential (reference potential) between the light emitting sources. Are connected to each other and connected to the negative electrode of the power supply unit 18. The layer thickness of the aluminum electrode 7 is preferably about 150 nm.
In the present embodiment, the pixel electrode portions 7b... Provided in a substantially U shape in a BB sectional view covering the upper surface and the side surface of the organic EL layer 5 corresponding to the strip shape of the ITO electrode 4, and the pixel electrode portion 7b. .. At the end in the longitudinal direction, and a conducting portion 7c for conducting each of them. For example, a rectangular opening 7a is formed on the upper surface of the approximate center in the longitudinal direction of each pixel electrode portion 7b.
Therefore, the aluminum electrode 7 substantially covers the optical waveguide layer except for the opening 7a, and can reflect the recording light propagating through the optical waveguide layer. Therefore, the light sealing means for sealing the recording light propagating through the optical waveguide layer is configured together with the reflective layer 3a and the clad layer 3b.

The pitch between the openings 7a is set to an appropriate value according to the pixel arrangement pitch of the optical recording surface itself, or in the case where a condensing element is disposed between the recording unit 17 and the optical recording surface. Is done. In this embodiment, for example, the pitch is 20 μm. This arrangement pitch is also an arrangement pitch in the short direction of one light emitting source.
Accordingly, the size of the opening 7a in plan view can be set as appropriate within the range of this pitch, but it is preferable to make it as large as possible.
Further, the shape is not limited to a rectangle, and may be an appropriate shape such as a square shape, a circular shape, or an elliptical shape.

According to such a configuration, a larger light output can be extracted as compared with the case where the area of the light emitting layer coincides with the opening.
In addition, when an image is formed on the optical recording surface by arranging a condensing element on the aperture, for example, a simple condensing element such as a spherical lens is arranged compared to a case where the aspect ratio of the aperture is large and the light emission image is flat. The advantage is that a spot having a different shape can be obtained, and the size and shape of the spot diameter can be set relatively easily.

The sealing film 8 is a transparent film for covering and protecting the entire upper surface of the recording unit 17, and for example, an Al ₂ O ₃ / SiO ₂ film deposited by about 50 nm can be employed.

The scattering unit 6 scatters the recording light in a direction different from the optical path of the regular reflection light with respect to the reflection layer 3a (cladding layer 3b) by reflecting or refracting the recording light incident at a constant incident angle. It is a member.
FIG. 2A shows an example in which the scattering portion 6 is configured by disposing granular bodies 11... Having a refractive index different from that of the optical waveguide layer on the cladding layer 3b and below the opening 7a. Although FIG. 2A is a schematic diagram, it is drawn in a simplified manner. However, the granular bodies 11 may be arranged directly on the cladding layer 3b, may be arranged in layers, or may be an optical waveguide. You may disperse | distribute and arrange | position in a layer. Moreover, as long as it is in the optical waveguide layer through which the recording light passes, it may be arranged in either the ITO electrode 4 or the organic EL layer 5.
The granular material 11 is preferably a fine particle having a refractive index larger than that of the optical waveguide layer in order to increase the reflectance with respect to the recording light and facilitate the scattering.
For example, fine particles of titanium dioxide TiO ₂ , for example, those having a particle size of 30 nm to 50 nm can be employed. The refractive index of TiO ₂ is about 2.4 or more in the visible light wavelength region, and is higher than both the ITO electrode 4 and the organic EL layer 5.

A method for manufacturing the optical recording head 1 of the present embodiment will be described focusing on the method for manufacturing the recording unit 17.
First, the reflective layer 3a is patterned on the glass substrate 2 as necessary, and Cr (chromium) is deposited to form a metal layer having a thickness of about 100 nm.
A SiO ₂ layer having a thickness of about 150 nm to 500 nm is formed thereon as the cladding layer 3b.

Next, the layer of the granular material 11 is patterned in the part where the scattering part 6 is provided.
For example, a solution in which about 5 to 30% of a TiO ₂ alcoholate (for example, SYM-T105 manufactured by Koyo Chemical Co., Ltd.) is mixed in a solution in which 15 wt% of TiO ₂ fine particles are dispersed in IPA is dropped onto a predetermined portion by an inkjet method. . Then, it is dried at 180 ° C. for 20 minutes.
In this way, as the TiO ₂ fine particles extremely thin TiO ₂ layer is secured on the glass substrate 2, scattering portion 6 is formed.

Next, the ITO electrode 4 is formed.
First, ITO is formed into a film with a thickness of about 0.4 μm by a sputtering method, and etched according to a predetermined arrangement pattern in which the scattering portion 6 comes to substantially the center of each ITO electrode 4.
Then, the organic EL layer 5 is formed so as to cover the upper surface of the ITO electrode 4. That is, by vacuum deposition, for example, TPD is formed at a film formation rate of 0.1 nm / s, and Alq3 is formed on the upper surface thereof at the same film formation rate. In either case, patterning is not particularly required.
Thereafter, in order to continuously form the aluminum electrode 7, the pixel electrode portion 7b covers the ITO electrode 4 and the organic EL layer 5 on the upper surface side and the sides thereof using a metal mask, and a predetermined opening 7a. Then, aluminum is deposited by patterning into a predetermined pattern so as to form the conductive portion 7c. The film formation rate is preferably about 0.05 nm / s.
In this way, the recording unit 17 can be formed.

Although a detailed description is omitted, the drive control unit 19 can be manufactured by forming a necessary circuit pattern on the glass substrate 2 together with the recording unit 17. The optical recording head 1 is manufactured by wiring an appropriate power supply unit 18, arranging a condensing element (not shown) on the opening 7 a as necessary, and storing the condensing element in an appropriate housing or the like.
As the light condensing element, for example, a lens array made of a synthetic resin molded product or the like can be used. In this case, the optical axis direction is arranged according to the normal direction of the surface where the opening 7 a is formed, that is, the normal direction of the glass substrate 2. Therefore, by providing an attachment area on the glass substrate 2 that avoids a circuit area or the like, it is possible to attach the light collecting element easily and easily by attaching an attachment or positioning leg.

Next, the operation of the optical recording head 1 of this embodiment will be described.
FIG. 3 is a schematic explanatory diagram of a cross section in the layer thickness direction for explaining the operation of the optical recording head 1 according to the first embodiment of the present invention.

When an image signal is input to the drive control unit 19 and a specific light source is switched, a drive voltage is applied between the ITO electrode 4 and the aluminum electrode 7 of the light source.
Thereby, in the organic EL layer 5, electrons move from the aluminum electrode 7 side, holes move from the ITO electrode 4 side, and they recombine inside the organic EL layer 5, resulting in electroluminescence emission. Is called.
That is, the organic EL layer 5 emits light in various directions from the inside to the outside of the organic EL layer 5 as a surface light source.

As shown in FIGS. 1B and 1C, the light emitted from the organic EL layer 5 is a recording light 9 a emitted to the outside through the opening 7 a, a light beam composed of the ITO electrode 4 and the organic EL layer 5. The recording light 9b is repeatedly reflected inside the wave layer. Of the recording light 9b, the light incident on the opening 7a at an angle that passes through the optical waveguide layer is emitted from the opening 7a as the recording light 9a.
At this time, since the scattering portion 6 is provided in the present embodiment, the ratio of the recording light 9b emitted from the opening 7a can be increased as compared with the case where the scattering portion 6 is not provided.

This point will be described with reference to FIG.
Since the ITO electrode 4 and the organic EL layer 5 have different refractive indexes, they are refracted and reflected at their boundary surfaces. For simplicity, the following description will be made assuming that light travels straight in these optical waveguide layers. .

As shown in FIG. 3, when there is no scattering portion 6 (broken line in the drawing), the clad layer 3b that confines the recording light 9b and the reflective layer 3a form a uniform reflective surface, facing the aluminum electrode 7 and parallel reflective surfaces. Is formed. In the lateral direction, light is confined by the aluminum electrode 7 as shown in FIG.
When the recording light 9b is incident at a relatively large incident angle theta ₁ as light R _4, is reflected by the exit angle theta _1, light propagation is repeated in the direction perpendicular to the thickness direction of the optical waveguide layer. If the incident angle θ ₁ exceeds the critical angle, even if the reflection layer 3a and the clad layer 3b are not present, total reflection occurs and similar propagation occurs.
Further, when the recording light 9b is incident at a relatively small incident angle theta ₂ as rays R _1, a ray R ₃ is reflected by the exit angle theta _2, the refraction angle theta ₃ cladding layer 3b is refracted _{(theta 3} > θ ₂ ), and the light ray R ₂ travels. Rays R ₂ are reflected by the reflective layer 3a, the incident angle is as large light than theta _2, is reflected in the optical waveguide layer.

Although the recording light 9b has various incident angles, since the optical waveguide layer is sandwiched between the parallel reflection surfaces, the recording light 9b repeats propagation in a steady reflected light path. Therefore, the recording light 9b having a relatively small incident angle has a short reflection point pitch, and when it reaches the vicinity of the opening 7a, the recording light 9b is emitted from the opening 7a to become the recording light 9a, but an optical path having a relatively large incident angle. In the recording light 9b, since the pitch of the reflection points is large, the probability of reaching and exiting the opening 7a is small. Further, when the incident angle satisfies the total reflection condition, the total reflection is repeatedly confined.
Therefore, most of the recording light 9b propagating through the optical waveguide layer is not emitted from the opening 7a as the recording light 9a.

On the other hand, in the case of the present embodiment, as shown by the broken line, the scattering portion 6 made of the granular material 11 is disposed on the cladding layer 3b and below the opening 7a, so that the light rays R ₁ and R incident on the scattering portion 6 are disposed. ₄ propagate as light rays S ₁ and S ₂ that are scattered by the particles 11 and emitted in directions that are independent of the incident angle, for example, with a relatively small exit angle. If the particle size of the granular material 11 is set appropriately, the scattering unit 6 is the same as the point light source distributed at that position.
Therefore, these are emitted from the opening 7a and added to the recording light 9a, and the ratio of the recording light 9b emitted from the recording light 9b is increased.
As a result, most of the light emitted from the organic EL layer 5 is emitted as the recording light 9a from the opening 7a.

Thus, according to the optical recording head 1 of the present embodiment, the light emitted from the organic EL layer 5 wider than the opening 7a propagates in the optical waveguide layer and is emitted from the opening 7a with high efficiency. Therefore, a high-output light source can be formed as compared with a light source whose light emitting layer has the same area as the opening 7a.
Therefore, for example, it can be suitably used as an exposure unit of an image forming apparatus that requires high output for forming a latent image.
Further, since the opening 7a is provided at a position where the recording light can be emitted in the layer thickness direction of the light emitting layer, the opening 7a can be set to have a larger area compared to the case where the opening is provided on the side end surface of the light emitting layer.
In addition, the shape of the opening has a high degree of freedom, and a spot diameter that is uniform when focusing on the optical recording surface can be formed. For example, if the aspect ratio is a rectangle close to 1, the image on the condensing side is also substantially rectangular without special aberration correction, so that a simple condensing element can be used.

  Further, in the case of providing a condensing element that condenses the recording light 9a, it can be provided on the surface of the glass substrate 2, so that it is easy to provide an attachment area avoiding a circuit area and the like, and the degree of freedom of installation is increased. Therefore, the optical recording head 1 can be easily assembled.

Next, a first modification of the present embodiment will be described.
In this modification, as shown in FIG. 2A, the optical recording head 1 of the first embodiment includes an organic EL layer 5 </ b> A instead of the organic EL layer 5. Instead, the phosphor particles 12 are provided.

The organic EL layer 5A emits light having an excitation wavelength of the phosphor particles 12. For example, TPD as a hole transport layer, and triazole (Triazole) as a fluorescent material serving as both a light-emitting layer and an electron transport layer. ) A structure in which a derivative (such as DA-TAZ) is laminated is adopted.
According to such an organic EL layer 5A, the emission wavelength is around 400 nm to 460 nm.

The phosphor particles 12 are fine particles made of a phosphor that emits light with the wavelength of light generated in the organic EL layer 5A. The particle size can be, for example, approximately the same as that of the granular material 11, but may be larger than the granular material 11 as long as it can be disposed in the optical waveguide layer. The emission wavelength of the phosphor particles 12 is set within a range included in the wavelength sensitivity region of the optical recording surface.
This modification employs phosphor particles that have an excitation wavelength in the blue region near 460 nm and emit light in the 570 nm band. Examples of such phosphor particles include YAG phosphor P46-Y3 manufactured by Kasei Optonix.
The wavelength of 570 nm has sufficient sensitivity for a photosensitive drum used in, for example, a copying machine or an optical printer.

  According to such a configuration, in the manufacturing method of the above embodiment, the triazole derivative and the phosphor particles 12 can be replaced in place of Alq3 and the granular material 11, and the same manufacturing can be performed.

According to this modification, a part of the recording light 9 b incident on the scattering portion 6 is scattered by the phosphor particles 12 and the other is absorbed by the phosphor particles 12. Since the recording light 9b has a wavelength in the vicinity of 400 nm to 460 nm, it excites the phosphor particles 12 in the blue region having an excitation wavelength near 460 nm to generate light having a wavelength of 570 nm. Since the exit angle of the excitation light does not depend on the incident angle of the recording light 9b and is emitted in a random direction, it is easily emitted from the opening 7a like the scattered light. The emitted excitation light can be optically recorded on the optical recording surface.
Thus, in this modification, since the recording light 9b propagating through the optical waveguide layer is also used as the excitation light and emitted from the opening 7a, the recording light 9b can be converted into the recording light 9a more efficiently.

Next, a second modification of the present embodiment will be described.
FIG. 2B is a schematic explanation of a cross-sectional view taken along the line AA of FIG. 1A for explaining the scattering means used in the optical recording head of the second modified example of the first embodiment of the present invention. FIG.
In this modification, as shown in FIG. 2B, the scattering portion 6 of the optical recording head 1 of the first embodiment includes a diffraction grating 13 instead of the granular material 11.

  The diffraction grating 13 is provided for diffracting the incident recording light 9b in various directions to change the optical path. For example, the grating 13 is chirped with a period of several to several tens of wavelengths to emit outgoing light. It consists of a chirped grating in which the direction can be continuously varied within an appropriate angle range. As a technique for controlling the optical path and the diffusion range by using such chirped grating, for example, a technique described in Japanese Patent Application Laid-Open No. 2004-95138 can be suitably employed.

In the manufacturing method of this modification, the diffraction grating 13 is formed instead of patterning the layer of the granular material 11 in the first embodiment. That is, the manufacturing process below the opening 7a forming the scattering portion 6 is changed as follows.
Before the ITO electrode 4 is formed, for example, a resist is patterned by using an EB drawing apparatus, and the glass substrate 2 located below the opening 7a is etched to have a depth of about 0.1 μm at a predetermined grating period. A lattice groove is formed.
For example, patterning is performed so as to cover a portion other than the portion where the lattice grooves are formed with a hydrofluoric acid resistant resist, etching is performed using hydrofluoric acid, and the resist is removed after the lattice grooves are eroded.
Then, the ITO electrode 4 is directly formed thereon, thereby forming a refractive index distribution type diffraction grating.
By setting such a grating period Λ, efficient diffraction can be performed. Therefore, a large amount of high-order diffracted light is generated by the recording light 9b, and light can be scattered in various directions.

  According to this modification, the recording light 9b incident on the scattering unit 6 at various incident angles can be diffracted and scattered in various directions by high-order light. Therefore, there is an advantage that the degree of scattering can be easily varied by adjusting the grating period according to the wavelength of the recording light 9b. Further, since the refractive index distribution type diffraction grating is used, there is an advantage that it can be easily manufactured by patterning.

Next, a third modification of the present embodiment will be described.
FIG. 2C is a schematic description of a cross-sectional view taken along the line AA of FIG. 1A for explaining the scattering means used in the optical recording head of the third modified example of the first embodiment of the present invention. FIG.
In this modification, as shown in FIG. 2C, the scattering portion 6 of the optical recording head 1 of the first embodiment is arranged on the upper surface of the organic EL layer 5 located in the opening 7a. A diffraction grating 14 is formed as the scattering portion 6.

  The diffraction grating 14 diffracts the light passing through the opening 7a out of the recording light 9b reflected by the cladding layer 3b, the reflection layer 3a, etc. It is made to radiate | emit with. That is, the 0th-order light is emitted in the same manner as when the diffraction grating 14 is not provided, but the high-order light is emitted at an angle different from that of the 0th-order light. Therefore, the recording light 9a that has a small emission angle and is easy to collect is increased by the high-order light.

In the manufacturing method of this modification, in the first embodiment, instead of forming the scattering portion 6 below the opening 7a, the organic EL layer 5 is formed, and then the ITO electrode 4 has a grating period determined by the equation (1). A grating is formed by etching a material having a refractive index different from that of, for example, SiO ₂ .

Next, a fourth modification of the present embodiment will be described.
FIG. 2D is a schematic explanation of a cross-sectional view taken along the line AA of FIG. 1A for explaining the scattering means used in the optical recording head of the fourth modified example of the first embodiment of the present invention. FIG.
In the present modification, as shown in FIG. 2D, a diffusion layer 60 is formed on the upper surface of the organic EL layer 5 located in the opening 7a, instead of the diffraction grating 14 in the third modification.

The diffusion layer 60 is used to emit the diffused light to the outside when transmitting the light passing through the opening 7a among the recording light 9b reflected by the cladding layer 3b, the reflective layer 3a, and the like.
As the diffusion layer 60, for example, a film layer of TiO ₂ having a high refractive index can be employed.

In the manufacturing method of this modification, in the first embodiment, instead of forming the scattering portion 6 below the opening 7a, after forming the organic EL layer 5, the aluminum electrode 7 is formed to cover the opening 7a. It can be manufactured by EB deposition of a patterned TiO ₂ film. The film thickness of the TiO ₂ film is set so that the spread of the diffused light is in an appropriate range.

Next, a fifth modification of the present embodiment will be described.
FIG. 4A is a schematic explanation of a cross-sectional view taken along the line AA of FIG. 1A for explaining the scattering means used in the optical recording head of the fifth modified example of the first embodiment of the present invention. FIG.

In this modification, uneven portions 15a and 15b (uneven portions) are formed as scattering means instead of the scattering portion 6 of the optical recording head 1 of the above embodiment.
As shown in FIG. 4A, the uneven portion 15a is provided in the organic EL layer 5 located in the opening 7a, and the depth of the recessed portion is 0.2 μm to 20 μm, more preferably 0.4 μm to 5.0 μm. It is said.
Although FIG. 4A is a schematic diagram, it is drawn in a cross-sectional mountain shape, but the cross-sectional shape is not limited to a mountain shape as long as irregularities are formed. For example, the concave portion may be a U-shaped groove, or the convex portion may be formed of a curved surface. Further, the shape of the concavo-convex portion 15 in plan view may be connected linearly or may be dispersed in the form of dots.
In the uneven portion 15a of this modification, the uneven portion 15b having the same shape is formed on the glass substrate 2, and the same unevenness is formed on each of the reflective layer 3a, the clad layer 3b, the ITO electrode 4, and the organic EL layer 5. Has been.

In order to manufacture such uneven portions 15a and 15b, first, the glass substrate 2 is patterned so as to cover a portion other than the portion where the concave portions of the uneven portion 15b are formed with a hydrofluoric acid resistant resist, and then etched with hydrofluoric acid. Do. As a result, the portion of the glass substrate 2 that is not covered with the resist is etched and eroded into a concave shape.
Thereafter, the resist is peeled off, and the reflective layer 3a, the clad layer 3b, the ITO electrode 4, and the organic EL layer 5 are formed in the same manner as in the first embodiment.
As a result, each of these layers is formed substantially in parallel along the unevenness on the glass substrate 2, and the uneven portion 15a is formed.

The operation of the concavo-convex portions 15a and 15b, which are the scattering means of this modification, will be described.
FIG. 5 is a schematic explanatory view of a cross section in the layer thickness direction for explaining the operation of the optical recording head 1 of the fourth modified example of the first embodiment of the present invention.

As in the case of FIG. 3, for the sake of simplicity, description will be made assuming that refraction and reflection do not occur at the interface between the ITO electrode 4 and the organic EL layer 5.
As shown in FIG. 5, a cladding layer 3b (reflective layer 3a), by entering a relatively large incident angle theta ₁ with respect to the aluminum electrode 7, and propagates the light-emitting layer while being repeatedly reflected between them Consider the rays R ₄ and R ₅ that form a steady reflected light path.
When the uneven portions 15a and 15b are not present, the light rays R ₄ and R ₅ have a low chance of reaching the opening 7a or are highly likely to be totally reflected even if they reach (shown broken lines).

On the other hand, in the case of this embodiment, since the uneven part 15b is formed on the glass substrate 2 and the uneven part 15a is formed on the surface of the organic EL layer 5, the probability that the incident angle is reduced also with the light rays R ₄ and R ₅ increases.
For example, since the light ray R ₄ is incident on the inclined surface of the opening 7 a at an incident angle θ ₃ (where θ ₃ <θ ₁ ), the light ray R ₄ is emitted from the opening 7 a as the light ray P ₄ . Further, for example, the light ray R ₅ is incident on the cladding layer 3b (reflective layer 3a) at an incident angle θ ₄ (where θ ₄ <θ ₁ ), so that the optical path is converted to the layer thickness direction side, and the light passes through the opening 7a. Emitted. Moreover, it may be re-reflected by the surface of the uneven part 15a after emission.
As described above, the recording light 9b is scattered below the opening 7a by the concave and convex portions 15a and 15b, and the ratio of the recording light 9a emitted from the opening 7a is increased.
On the contrary, if there is no uneven portion 15a, 15b, a part of the light emitted as the recording light 9a may be totally reflected and return to the optical waveguide layer, but there is a low probability that it will be totally reflected subsequently. Therefore, as a whole, a scattering effect occurs and the recording light 9a increases.

In this modification, there is an advantage that the scattering method can be appropriately set by changing the depth and pitch of the concave portions of the concave and convex portions 15a and 15b.
In addition, in this modification, although the case where both the uneven | corrugated | grooved parts 15a and 15b were formed was demonstrated, only any one may be formed. Even in that case, it is clear that it can be a scattering means.

Next, a sixth modification of the present embodiment will be described.
FIG. 4B is a schematic description of a cross-sectional view taken along the line AA of FIG. 1A for explaining the scattering means used in the optical recording head of the sixth modified example of the first embodiment of the present invention. FIG.

In this modification, instead of the concavo-convex parts 15a and 15b of the fourth modification, the concave holes 16a and 16b having only concave parts are provided as scattering means.
As shown in FIG. 4B, the recessed hole portion 16a is formed by forming a recessed portion of about 0.2 μm to 20 μm, more preferably about 0.4 μm to 5.0 μm in the organic EL layer 5 below the opening 7a. It is. The shape of the recess may be a smooth curved surface such as a spherical surface, but is not particularly limited thereto, and may be an appropriate curved surface or a collection of flat surfaces. Moreover, the surface may not be smooth.
And the surface of the glass substrate 2 is recessed like the uneven | corrugated | grooved part 15a, the recessed hole part 16b is formed, and the reflection layer 3a, the clad layer 3b, and the ITO electrode 4 are also concave.

According to the present modification, the boundary surface of the organic EL layer 5 is inclined by the recessed hole portion 16a, so that the recording light 9b is easily transmitted toward the opening 7a as in the fourth modification. Further, since the reflection hole 3b and the cladding layer 3b are formed in a concave shape by forming the concave hole portion 16b, the recording light 9b incident thereon is reflected and scattered according to the curvature of the concave portion, and there is no concave portion. Compared to the case, the amount of light toward the opening 7a increases.
And according to this modification, since a simple shape is provided, there exists an advantage that manufacture becomes easy. In addition, there is an advantage that light loss due to multiple reflection can be reduced.

[Second Embodiment]
Next, an image forming apparatus according to a second embodiment of the present invention will be described.
FIG. 6 is a schematic explanatory diagram for explaining the configuration of the main part of the image forming apparatus according to the second embodiment of the present invention.

  The optical printer 100 (image forming apparatus) of this embodiment is an apparatus for printing on a print medium 28 using electrophotography by a one-component non-contact developing method, and the main part thereof is as shown in FIG. The image forming apparatus includes a photosensitive drum 20 (photosensitive member), a charging roller 21, an optical recording head 200 (exposure unit), a developing device 30 (developing unit), a transfer roller 27, a signal processing unit 31, and a power supply unit 18.

The photosensitive drum 20 is a cylindrical drum having a photoconductive photosensitive layer formed on the surface and an optical recording surface having wavelength sensitivity in a certain wavelength range. The photosensitive drum 20 is rotationally driven in a direction indicated by an arrow by a driving unit (not shown). Is done.
The charging roller 21 is a conductive rubber roller that rotates in contact with the photosensitive drum 20. The roller shaft is electrically connected to a high voltage power source (not shown) and uniformly charges the surface of the photosensitive drum 20.

The schematic configuration of the optical recording head 200 includes a lens 1a (light condensing element) that forms an image of recording light on the optical recording surface with a predetermined spot diameter, a recording unit 17, and a drive control unit 19, and is sent from a signal processing unit 31. Exposure means for irradiating the photosensitive drum 20, which is an optical recording surface, with recording light emitted from each light source in response to an image signal.
In the exposed portion of the recording light, the charge on the photoreceptor layer is discharged, so that the difference in surface potential between the exposed portion and the non-exposed portion distributed corresponding to the image signal is recorded, and a so-called electrostatic latent image is formed. The The exposure position is provided at a predetermined position on the downstream side of the charging roller 21.
The wavelength of the recording light can be set to an appropriate wavelength range in the visible light range, and can be set to a frequency around 550 nm, for example. It is easy to give the wavelength sensitivity of the photosensitive drum 20 within the range.

The optical recording head 200 can adopt all the configurations of the optical recording head 1 described in the first embodiment or a configuration in which they are appropriately combined.
Each opening 7a can be arranged linearly at a pitch that matches the pixel density of the optical recording surface, for example.
As the lens 1a, for example, a lens array made of a synthetic resin molded product or the like can be used. The optical axis of each lens is fixed to the attachment region provided in the non-circuit region on the glass substrate 2 with, for example, adhesion, with the optical axis of each lens being arranged at the center of the opening 7a.

The developing device 30 is a mechanism for, for example, charging the toner 26 having a negative charging polarity to visualize the electrostatic latent image formed on the photosensitive drum 20, and is close to the photosensitive drum 1 on the downstream side of the exposure position. Is provided. The schematic configuration includes a developing roller 22 made of a conductive rubber roller, a developing blade 23 that forms a thin layer of charged toner 26 on the developing roller, a supply roller 24 that supplies the toner 26 to the developing roller 22, and a friction of the toner 26 It comprises a stirring blade 25 that is charged and conveyed to the supply roller 24.
The developing roller 22 is provided with a cap spacer collar 29 for ensuring a certain gap with the photosensitive drum 20, and a high voltage (not shown) is used to obtain an electric field for selectively moving the toner 26 to the electrostatic latent image. It is electrically connected to the power source.

  The transfer roller 27 is provided downstream of the developing device 30 and applies a transfer voltage when the print medium 28 arrives, so that the toner image (visible image) developed on the photosensitive drum 20 is statically transferred to the print medium 28 side. A conductive roller for electroadsorption. And it is electrically connected to a high voltage power supply (not shown).

According to such a configuration, each light source of the optical recording head 200 is controlled to be turned on in accordance with an image signal sent from the signal processing unit 31 to form an electrostatic latent image on the photosensitive drum 20 and developed. It can be developed by the device 30. Then, the toner image can be transferred to the print medium 28 by the transfer roller 27 and fixed by a fixing means (not shown) to form an image.
According to the optical printer 100 of the present embodiment, since the optical recording head 200 having the configuration of the optical recording head of the first embodiment is used, the image forming apparatus having the effects of the optical recording head according to the first embodiment. It can be.

  In the above description, the example in which either the clad layer or the reflective layer is arranged between the base substrate and the second electrode has been described. It may be omitted.

  In the above description, the example in which the opening is provided in the light reflective electrode has been described. However, when the transparent electrode is provided, the light reflecting layer is provided on the transparent electrode, and the light reflecting layer is provided with the opening. Also good.

  In the above description, the openings are linearly arranged with a predetermined pitch apart. However, since the openings are provided in a direction along the plate surface of the base substrate, the two-dimensional layout can be obtained by appropriately laying out the circuit pattern. May be arranged. For example, it may be arranged in a zigzag pattern or linearly extended in a plurality of rows.

  In the above description, the example in which each scattering unit is provided individually has been described. However, if possible, the scattering unit may be combined.

In the above description, since the transparent electrode is used as the second electrode, the example in which the optical waveguide layer is configured by the light emitting layer and the transparent electrode has been described. However, the light emitting layer sandwiched between the first and second electrodes is described. The second electrode may be composed of a light-reflective electrode as long as the containing layer can be guided in light.
In the above description, the case where the light emitting layer is formed of an organic EL layer has been described. However, the present invention is not limited to such a configuration, and other configurations may be employed as long as the light emitting layer can emit light. For example, inorganic EL may be used.

  In the above description, ITO is used as the transparent electrode. However, the material is not limited to ITO. For example, IZO (Indium Zinc Oxide) can also be suitably employed.

FIG. 2 is a schematic explanatory view in plan view for explaining the configuration of the main part of the optical recording head according to the first embodiment of the present invention, its AA sectional view and BB sectional view. FIG. 4 is a schematic explanatory view in cross-sectional view taken along the line AA of FIG. 1A for describing the scattering means used in the optical recording head according to the first embodiment of the present invention and the first to fourth modifications thereof. is there. FIG. 3 is a schematic explanatory diagram of a cross section in the layer thickness direction for explaining the operation of the optical recording head 1 according to the first embodiment of the present invention. It is a schematic explanatory drawing of the cross-sectional view in alignment with the AA of FIG. 1 (a) for demonstrating the scattering means used for the optical recording head of the 5th and 6th modification of the 1st Embodiment of this invention. FIG. 10 is a schematic explanatory diagram of a cross section in the layer thickness direction for explaining the operation of the optical recording head 1 of the fifth modified example of the first embodiment of the present invention. FIG. 6 is a schematic explanatory diagram for explaining a configuration of a main part of an image forming apparatus according to a second embodiment of the present invention.

Explanation of symbols

1 Optical recording head 2 Glass substrate (base substrate)
3a Reflective layer 3b Clad layer 4 ITO electrode (second electrode)
5 Organic EL layer (light emitting layer)
6 Scattering part (scattering means)
7 Aluminum electrode (first electrode)
7a Apertures 9a, 9b Recording light 11 Granules (scattering means)
12 Phosphor particles (scattering means)
13, 14 Diffraction grating (scattering means)
15a, 15b Uneven portion (unevenness)
16a, 16b Recessed hole (unevenness)
17 Recording section 18 Power supply section 19 Drive control section 20 Photosensitive drum (photoconductor)
30 Developer (Developing means)
31 Signal processor 60 Diffusion layer (scattering means)
100 Optical printer (image forming apparatus)
200 Optical recording head (exposure means)

Claims (8)

A second electrode disposed opposite to the first electrode set to a reference potential and applying a drive voltage in accordance with an image signal; and sandwiched between the first electrode and the second electrode; A plurality of light emitting sources having a light emitting layer for generating recording light in response to the driving voltage and an opening for emitting the recording light to the outside are formed on the plate surface of the base substrate and the plate surface of the base substrate An optical recording head including an optical recording unit in which the openings are arranged in accordance with pixel positions on the optical recording surface in a direction along
Each light emitting source is formed with an optical waveguide layer capable of propagating recording light generated by the light emitting layer in a direction perpendicular to the layer thickness direction of the light emitting layer,
The area in the thickness direction of the light emitting layer of each light emitting source is set to be larger than the opening area of each corresponding opening,
Each opening is provided at a position where recording light propagating through the optical waveguide layer can be emitted in the layer thickness direction of the light emitting layer,
Around the optical waveguide layer, there is provided a light sealing means for confining the emitted light from other than the opening of the recording light in the optical waveguide layer,
An optical recording head characterized in that a scattering means for disturbing an optical path of the recording light propagating in the optical waveguide layer is provided in the optical waveguide layer positioned in the opening.   The optical recording head according to claim 1, wherein the scattering unit includes a plurality of granular materials having different refractive indexes from the optical waveguide layer.   The optical recording head according to claim 2, wherein the granular body is made of a phosphor whose light is excited by the wavelength of the recording light.   The optical recording head according to claim 1, wherein the scattering unit includes a diffraction grating.   2. The optical recording according to claim 1, wherein the scattering unit includes irregularities provided on at least one of a surface of the opening-side layer of the optical waveguide layer positioned in the opening and a bottom surface of the layer facing the surface. head. The light emitting layer is composed of an organic EL layer,
One of the first and second electrodes comprises a transparent electrode that transmits the recording light,
The other of the first and second electrodes is a light reflective electrode that reflects the recording light,
The light emitting layer and one of the first and second electrodes constitute the optical waveguide layer,
The optical recording head according to claim 1, wherein the opening is formed in the other of the first and second electrodes.   The optical recording head according to claim 6, wherein the transparent electrode has a thickness of 50 nm to 1000 nm. An image forming apparatus that forms an electrostatic latent image on a photosensitive member having a photoconductive optical recording surface by using an exposure unit, and develops the electrostatic latent image by a developing unit to form a visible image.
An image forming apparatus using an optical recording head, wherein the exposure unit includes the optical recording head according to claim 1.

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