JPH0667108A - Rotating mirror and its production - Google Patents

Abstract

PURPOSE:To provide the rotary mirror which is high in production efficiency, is inexpensive, has high accuracy, simplifies the process for production in the case of use of the mirror as an optical polarizer and facilitates the assembly and adjustment thereof. CONSTITUTION:Film-like layers consisting of a resin are formed in multiple layers on the surfaces to be formed as reflection mirror surfaces on the peripheral surfaces of a base body having a circular columnar or prism-shaped parts, by that, the resin films of good surface accuracy transferring the shapes and planes of molds and other transfer plates with extremely high accuracy are formed and thin films having a high light reflectivity are formed on these resins, by that, the rotary mirror having the high accuracy is inexpensively produced. The resins shrink by several % to several 10% at the time of solidifying, but the flatness of the resins is made extremely small and uniform every time when the resin layers are superposed even if the base body having the poor surface roughness is used. The transferability of the shapes and planes of the molds and other transfer plates of the resins are improved. There is no need for correcting a surface inclination if the base plate mounted with a revolving shaft is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating mirror (hereinafter referred to as a rotating mirror) having one or a plurality of reflecting mirror surfaces used for scanning a laser beam in a laser beam printer or the like, and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a printing terminal for information equipment, a laser beam printer capable of printing on plain paper, excellent in printing quality, capable of high-speed printing, and quiet has rapidly spread in recent years. This laser beam printer is configured to reflect light emitted from a laser by a rotating mirror and irradiate a recording drum for recording.

FIG. 6 shows the configuration of a conventional general laser beam printer. As shown in the figure, the light of the semiconductor laser 61 modulated by the data signal is condensed on the recording drum 63 by a plurality of condenser lenses 62. A rotary polygon mirror 64 is disposed in the middle of the condenser lens, and the rotary polygon mirror 64 is rotated at a high speed to scan a laser beam, and a light spot 65 is scanned on the recording drum. On the other hand, the recording drum 63 is slowly rotated to perform sub-scanning, and is combined with the main scanning of the light spot to form the recording drum 63.
A two-dimensional recording latent image will be formed on top.

Now, in such a scanning optical system, in order to form one picture on the recording drum 63, the rotary mirror is required to have a considerable accuracy. That is, in order to obtain an excellent print quality with a constant scanning interval, the tilt angle error of the rotating mirror with respect to the reference surface must be within several tens of seconds. In addition, the flatness of the reflecting surface must be within a few λ (λ: wavelength of helium neon laser light 632.8 nm), the surface roughness must be less than a few hundred μm, and the reflectance must be 85% or more. . In order to satisfy such precision, conventionally, a structure was formed by cutting from an aluminum rod of high purity, and then the surface to be used as a reflection surface was mirror-cut with a lathe to obtain the surface accuracy of the reflection surface. It was

On the other hand, as a second conventional example, an attempt has been made to manufacture a mirror entirely of resin. In this method, an injection molding method is mainly adopted, polycarbonate is mainly used as a resin to be used, and a reflection film is formed on a surface to be a mirror surface by a vapor deposition method or the like.

When the rotating mirror is used as an optical deflector, the rotating mirror of the motor can be attached to the rotating shaft of the motor or the hub arranged on the rotating shaft with high accuracy. The process of killing has been taken.

[0007]

When a mirror is manufactured by the conventional manufacturing method as described above, if the mirror surface cutting is performed as in the first conventional example, the production efficiency is lowered and the extremely expensive N is used.
Since the C cutting device is required, there is a problem that the cost becomes high.

Further, in the method of injection molding a resin as in the second conventional example, since the resin molding die withstands a high pressure, it is necessary that the die be entirely made of metal. However, when trying to achieve the flatness and surface roughness required for a polygonal mirror with a metal mold, the stability of the mold material becomes a problem, and accurate mold material has poor workability and it is difficult to manufacture the mold. It gets harder. Moreover, since injection molding is performed at high temperature and high pressure, it is often difficult to ensure the accuracy of the molded product.

On the other hand, in the case of a resin molded product, when the ambient temperature rises, the dimensional change due to thermal expansion of the resin increases as the thickness direction as viewed from the mirror surface side of the resin forming the mirror plane increases. Moreover, since the mirror itself is not a uniform shape like a spherical surface, surface deformation easily occurs, and it may be out of the required accuracy immediately, so it was quite difficult to put it into practical use. Therefore, it is conceivable to uniformly reduce the thickness of the resin forming the mirror flat surface, and a thermally stable base with a small dimensional change is coated in the form of a resin film, and the coating film is provided with surface roughness and flatness. Attempts have been made to obtain a mirror surface by accurately forming the mirror surface. However, even in the above coating method, the resin is shrunk when it is solidified, and there is a limit in copying the shape and plane of a mold or other transfer plate onto the resin. In injection molding, since the resin portion is much thicker than the coating, the precision of the mold and other transfer plate shapes and the transferability of the flat surface is further deteriorated, and it has been difficult to manufacture a highly accurate rotating mirror.

Further, when the reflecting mirror manufactured by the above method is used as an optical deflector, the accuracy decreases when the reflecting mirror is mounted on the rotating shaft of the motor or the hub provided on the rotating shaft when mounted on the motor. There was a problem of doing.

The present invention solves such problems, and an object thereof is to provide a rotary mirror having high productivity, low cost, high precision, and a method for manufacturing a rotary mirror which has a simple process and is easy to assemble and adjust. It is what

[0012]

In order to solve this problem, the present invention provides at least a peripheral surface of a base having a cylindrical or polygonal columnar portion in a rotating mirror provided with at least one reflecting mirror surface. After a plurality of resin film layers are formed in multiple layers, a mirror surface is manufactured by forming a thin film having a high light reflectance on the multilayer resin film.

Further, in the above manufacturing method, when forming a multi-layered film-like resin layer, the surface roughness is set to Rmax 0.3 μm or more except for the resin layer at the outermost periphery from the base side, and only the outermost periphery resin layer needs the surface roughness. A high-precision mirror surface can be achieved by setting the mirror-surface accuracy to be equal to or less than that.

Further, a rotating mirror having at least one reflecting mirror surface is manufactured by the above manufacturing method, using a base having a cylindrical or polygonal cylindrical portion having a rotating shaft mounted at the center.

[0015]

As described above, according to the present invention, by forming a multi-layered resinous film layer on the surface to be the reflecting mirror surface around the base having the cylindrical or polygonal columnar portion as described above, a die or another transfer is formed. A highly accurate rotary mirror can be manufactured at low cost by forming a resin film having a high surface accuracy by accurately transferring a plate shape and a flat surface and forming a thin film having a high light reflectance on the resin. A few percent to a few tens of percent when resin solidifies
However, even if a base with poor surface accuracy is used, the film thickness of the resin can be made uniform each time the resin layers are stacked, and the shape of the resin mold or other transfer plate Transferability becomes good.

Further, by providing the base having thermal stability in the central portion, it is possible to provide a stable rotating mirror whose dimensional change is small with respect to ambient temperature change. Further, in the above rotary polygon mirror, the rotation axis is first fixed to the center of the base by a method such as shrink fitting, and the surface to be the reflection surface of the base with respect to the rotation axis is the above method, Since a rotating mirror can be manufactured by forming a coating film of resin, when used in an optical polarizer, the manufacturing process is simplified, there is no need to correct the surface tilt of the reflecting surface, and assembly and adjustment are easy.

[0017]

1 to 4 show an embodiment of the present invention. Hereinafter, the present invention will be described in detail with reference to these drawings.

FIG. 1 shows an example of the rotary hexahedron of this embodiment. For the base 13 having a polygonal columnar part, a resin molded product, metal or alloy having sufficient rigidity and good temperature characteristics is used. When a resin molded product is used for the base 13, tooling plastic (polycarbonate, acrylic, urethane, polyacetal, urea, polystyrene, polyethylene, etc.) alone, or rigidity, thermal characteristics,
A resin containing an additive (silica, wood, metal powder, etc.) to improve curing shrinkage, or a liquid crystal polymer which has recently been in the spotlight can be used. On the other hand, when a metal or alloy is used, metals such as Al and Cu or alloys thereof can be widely used. This is because the base 13 placed at the center is merely arranged to enhance rigidity and thermal stability, so that the processing accuracy of the surface and the ease of processing the surface do not pose a problem.

The reflecting surface 12 includes a resin layer 14 composed of three layers,
A high reflectance metal thin film 15 is formed on the resin layer 14 to form a mirror surface having a reflectance of 85% or more. The high reflectance metal thin film 15 may be any material as long as it efficiently reflects the wavelength region of the reflected laser light, such as Al, Au,
Cu, Ag, Ni, Cr or the like or alloys thereof can be formed by a method such as sputtering or vapor deposition.
The thickness is several hundred to several thousand Å. In the case of sputtering, for example, with Al, in order to maintain a high light reflectance, 500 Å or more is desirable, and when it is 1000 Å or more, white turbidity tends to occur. Further, in the case of a soft metal thin film, when a rotating mirror is mounted on a motor and rotated at high speed, dust in the air may collide with the mirror surface and scratch the reflective surface. For the purpose of protecting this, and for preventing moisture (rust) of the metal thin film, so as not to affect the reflectance of the laser light, a protective film (SiO ₂ , Al ₂ O ₃ or the like or those to which an additive is added) are preferably formed on the metal thin film 15 by a method such as vapor deposition or sputtering as a protective film.

In this structure, since the base 13 of the rotating mirror has a sufficiently rigid and thermally stable base material, a rotating mirror sufficiently stable against both high speed rotation and heat is provided. Since it can be manufactured by using a combination of extremely inexpensive materials, the manufacturing cost can be reduced.
First, the rotary shaft 11 is fixed to the base 13 by a method such as shrink fitting, a resin film is formed on the surface of the base 13 that is to be the reflecting surface with the rotary shaft 11 as a reference, and the metal thin film 15 is formed thereon. Form and manufacture a rotating mirror. By this method, the step of correcting the surface tilt of the reflecting surface becomes unnecessary, and the manufacturing process is simplified. Moreover, when the rotating mirror manufactured in this way is used for an optical polarizer, its assembly and adjustment are facilitated.

Next, as an example of a method of manufacturing a rotating mirror having this structure, a manufacturing method of forming a resin multilayer film by a coating method using a photo-curing resin is shown in FIG.

First, FIG. 2A shows the case where the first resin layer is formed. The surface of the base 21 having the rotation axis fixed, which is desired to be the reflection surface thereof, substantially faces the glass plate 22-1 which is a transfer plate for transferring the flat surface.
The rotary shaft 23 is set on the base holder 24 so that the angle between the 2-1 and the rotary shaft 23 becomes a predetermined tilt angle. Then, a photo-curing resin 25-1 is applied to the surface to be a reflecting surface, and a glass plate for plane transfer is placed on a glass positioning table 26 installed at a height such that the resin 25-1 can obtain a predetermined parallel film thickness. 22-1 is placed. In this state, the resin curing light is uniformly irradiated, and after the resin is cured, the glass plate 22-1 is peeled from the resin. The transfer plate 22-1 used at this time is made of glass having a good flatness and having its surface roughness roughened to about 0.3 μm or more by etching, polishing or the like.

Next, FIG. 2B shows the case where the resin layer is formed from the second layer onward to the layer further forward than the outermost periphery. Position the glass positioning table 26 by the thickness of the second resin layer,
The position is set higher than the position where the first resin layer was formed, and the resin layer is cured and the glass plate is peeled off by the same method as the first resin layer forming method. Thereafter, the resin layers from the outermost layer to the front layer are similarly shifted in height of the glass positioning table, so that a multilayer resin layer can be easily produced.

FIG. 2C is a view of forming the outermost resin layer. When forming n resin layers, the resin layers up to the (n-1) th layer are produced by the above method, and the outermost resin layer is similarly formed by transferring a glass plate for transfer by a predetermined resin layer thickness. Although it can be manufactured by shifting, the surface of the resin cured surface that is formed after the glass plate is peeled off by using a glass plate for transfer with high accuracy in flatness and surface roughness when forming the outermost peripheral resin. The roughness should be good.

Further, a rotary mirror can be manufactured by forming a high light reflecting film as described above in the explanation of FIG. 1 and, if necessary, a protective film on the multilayer cured resin film.

When the resin is formed in multiple layers, since the resin is cured on the resin, the adhesive force between the resin and the resin is the adhesive force between the cured resin and the glass plate for transfer or the mold surface. It is necessary to make the resin film on the base side satisfactorily, but the resin generally has better adhesion to the inorganic material such as glass and metal than the resin surface, and the transfer plate side It is unstable just to apply a release agent to the. Therefore, the resin cured surface from the first layer to the (n-1) th layer should have a certain degree of surface roughness, and the adhesion with the resin layer formed thereon can be physically improved. It becomes effective. It is meaningless that the flatness becomes worse than that before the resin film is formed by increasing the surface roughness, but the roughness for physically improving the adhesive strength is about Rmax of 0.3 μm or more, and there is hardening. As the transfer plate used from the layer to the (n-1) th layer, a plate having good flatness is used, and a plate having a uniform surface roughness by etching or polishing is used. It is possible to control the surface roughness to a constant value while improving the flatness. Since the resin surface on the outermost periphery serves as a reflection surface, the transfer plate is a glass plate or a mold surface with good flatness and surface roughness.

When the transfer agent is treated with a release agent so as to have a releasability from the resin, it is necessary to apply the release agent uniformly on the glass surface. Good results have been obtained by diluting. Further, the base can be subjected to a treatment for giving an adhesive force to the resin, if necessary. Especially when a resin is used for the base, various compounds such as a low molecular weight plasticizer, an anti-aging agent, a surfactant, and a release agent in the resin are often gathered on the resin surface. There are treatments such as removal by solvent and polishing treatment, and coating / drying of a primer solution having a polar group on the surface. Also,
In the case where the base is a metal or a metal alloy, primer treatment is effective, and as the primer, for example, by using a silane coupling agent or the like having a reactive group similar to the reactive group of the resin used at one end, The bonding force between the resin and the base metal can be improved by binding to the resin at one end of the coupling agent and reacting with the metal at the other end.

Even when the resin is cured in multiple layers, it is possible to treat the cured resin layer with a primer or the like after forming each layer. However, it is disadvantageous in terms of process. Therefore, in the case of curing the resin in multiple layers, the resin cured surface from the first layer to the (n-1) th layer has a certain degree of surface roughness as described above, and the resin formed thereon It is effective to physically improve the adhesion with the layer. However, when the release agent treatment is performed on the glass plate that is the transfer plate, the release agent may remain on the resin-cured coating surface when the glass plate is released after the resin is cured. If necessary, a washing step must be added as it may deteriorate the adhesion.

FIG. 3 shows details of the process in which the flatness is improved by forming the resin layers into multiple layers. In general, a photo-curing resin has a curing shrinkage of about 5 to 20%, and in FIG. 3, a resin having a shrinkage of 10% is used as an example for a base having a layer thickness of 50 μm and a surface step of 50 μm. Has become. Since the surface difference of the base is 50 μm, the film thickness of the applied resin has a maximum difference of 50 μm, but when this is cured with a shrinkage of 10%, the flatness on the base side of the first layer is within 5 μm. Therefore, in the second layer, the maximum film thickness difference of the applied resin is 5 μm, and when this is cured, a surface having a flatness within 0.5 μm is formed. Similarly, in the third outermost layer, a flatness of about 0.05 μm can be achieved if the flatness of the transfer plate is good. If only one resin layer is used, the transferability will be limited due to the shrinkage of the resin, no matter how good the accuracy of the transfer plate is. However, by using multiple layers, it is possible to perform transfer with extremely high accuracy. You can do it. Since the required accuracy as the mirror surface of the rotating mirror is covered by the resin multilayer film, the base lower surface of the base is not required to have high accuracy, and therefore, the requirements for the material and the manufacturing method of the base are lenient. However, although the actual calculation does not always follow the above calculation, the actual effect of the multi-layer coating will be shown in the description of FIG. 5 described later.

The thickness of the film-like resin is, of course, at least the "maximum difference between waviness, surface roughness, and step difference" of the base, but when the photocurable resin is used, it is too thick. The required amount of light rapidly increases and it takes a long time to cure, and it also becomes difficult for light to reach a sufficiently deep portion, so that problems such as partial uncured and easy troubles in curing occur. Also, the thicker the film, the greater the amount of dimensional change due to thermal expansion, etc., so the thinner the film, the more preferable is 5-300 μm.
Is good.

FIG. 4 shows that the photocurable resin is used in the manufacturing method shown in FIG. 2, the surface roughness of the transfer glass plate used when forming the first resin layer is changed, and the resin of the second layer is mirror-finished. 2 shows the probability that the second resin layer could be completely formed on the base side when a coating film having a two-layer resin structure was formed using the above transfer glass plate. If the roughness of the transfer plate used for forming the lower layer is smaller than Rmax 0.3 μm, the second plate is used when the transfer plate is peeled off after curing the second resin layer.
The second resin layer is likely to remain on the transfer plate side, causing chipping, etc.
There was no stability. A fluorine-based release agent was used for the transfer plate, and coupling-treated Al was used for the base to perform the test.

FIG. 5 shows the manufacturing method shown in FIG. 2. When a lower resin layer other than the uppermost layer is formed by using a photo-curing resin, a glass plate having a mirror surface precision is etched by a glass plate for transfer to have a surface roughness Rmax of 0.8 μm. Is a graph showing the result of the flatness at each number of layers when the resin of the uppermost layer is used and the resin for the uppermost layer is manufactured in multiple layers by using a glass plate for transfer having mirror surface accuracy. The base accuracy on the horizontal axis of the graph is the maximum difference value when the outer shape including undulation and surface roughness is measured. In addition, the resin layers were stacked with a thickness of 50 μm each. If the precision of the base used is poor, the roughness of the base cannot be covered with only one layer of the resin coating, but it was possible to secure the mirror surface precision by forming the resin coating in multiple layers.

Since the curing time of the photo-curing resin is as short as several seconds to several tens of seconds, the total time does not matter so much even when the cured coating film is manufactured one by one. It is also possible to cure several surfaces at a time, for example, by hardening every other surface together, which are not adjacent to each other, and thus productivity can be increased.

Further, the improvement of the planar transfer property by these multi-layer resin layers is effective not only for the photo-curing resin but also for the resin accompanied by shrinkage, and the thermosetting resin generally having a smaller curing shrinkage rate than the photo-curing resin. It is also effective for epoxy resins and unsaturated polyester resins.

[0035]

As is apparent from the above description of the embodiments, according to the present invention, in the rotating mirror having one or a plurality of reflecting mirror surfaces, the reflecting mirror surface on the surface of the base having the columnar or polygonal columnar portion. By forming multiple resin film upper layers on the surface to be formed, it is possible to accurately transfer the shape and flat surface of a mold or other transfer plate, and to obtain a resin film with extremely high surface accuracy. By forming a thin film having a high light reflectance on this resin, a rotating mirror with high accuracy can be manufactured at low cost. When the resin is solidified, it shrinks by several% to several tens%, but even if a base with poor surface accuracy is used, the flatness of the resin can be made small and uniform each time the resin layers are stacked. It is possible to improve the transferability of resin molds and other transfer plate shapes and flat surfaces.

Further, since the base having the thermal stability is provided in the central portion, the mirror-forming resin portion becomes a thin film having a substantially uniform thickness, so that it is possible to provide a rotating mirror which is stable against changes in ambient temperature. In the rotating mirror, the rotation axis is fixed to the center of the base by a method such as shrink fitting, and a resin coating film is formed on the surface to be the reflecting surface with the rotation axis of the base as a reference. Even when it is used as a polarizer, it is not necessary to correct the surface tilt of the rotating mirror, which facilitates assembly and adjustment.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing the structure of a rotary hexahedron mirror according to an embodiment of the present invention.

FIG. 2A is a diagram illustrating an example of a method for manufacturing a rotating mirror according to the present invention, in which a base for a hexagonal mirror having a rotating shaft mounted in the center is fixed, and a glass plate is positioned and fixed after applying a photo-curing resin. The figure which shows the resin film of the 1st layer is formed by irradiating curing light (B) The figure which shows the resin film of the 2nd layer (C) The resin film of the outermost layer is formed Figure

FIG. 3 is an explanatory diagram of accuracy of flatness of each layer when a multilayer film is used.

FIG. 4 is a characteristic diagram showing the results of stability of the second resin layer for a coating film formed in two layers by changing the surface roughness of the transfer glass plate used when forming the first resin layer.

FIG. 5 is a diagram showing a result of flatness at each number of layers when a resin is manufactured in multiple layers on a base having various surface precisions.

FIG. 6 is a diagram showing an optical scanning method of a laser beam printer.

[Explanation of symbols]

12 reflective surface 14 resin layer 15 metal thin film 21 base 22-1 etching transfer glass plate 22-2 transfer glass plate with good flatness and surface roughness 23 rotating shaft 24 base holder 25-1 photocurable resin First layer 25-2 Photo-curable resin Second layer 25-3 Resin cured film layer up to (n-1) th layer 25-4 Outermost peripheral n-layer photo-curable resin 27-1 Second layer spacer for resin thickness 27-2 Spacer for resin thickness up to (n-1) th layer

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 13, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art As a printing terminal for information equipment, a laser beam printer capable of printing on plain paper, excellent in printing quality, capable of high-speed printing, and quiet has rapidly spread in recent years. This laser beam printer is configured to reflect light emitted from a laser by a rotating mirror and irradiate a recording drum for recording.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

FIG. 6 shows the configuration of a conventional general laser beam printer. As shown in the figure, the emitted light from the semiconductor laser 61 modulated by the data signal is condensed on the recording drum 63 by a plurality of condenser lenses 62. A rotary polygon mirror 64 is arranged in the middle of the condenser lens, and the laser beam is scanned by the high speed rotation of the rotary polygon mirror 64, and a light spot 65 is formed on the recording drum.
Are scanned. On the other hand, the recording drum 63 is slowly rotated to perform sub-scanning, and is combined with the main scanning of the light spot to form a two-dimensional recording latent image on the recording drum 63.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Further , when the rotating mirror is used as an optical polarizer, the rotating mirror is attached to the motor with high precision by adhering it to the rotating shaft of the motor manufactured at a right angle or a hub arranged on the rotating shaft. The process of shrink fitting has been taken.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

FIG. 1 shows an example of the rotary hexahedron of this embodiment. For the base 13 having a polygonal columnar part, a resin molded product, metal or alloy having sufficient rigidity and good temperature characteristics is used. If the base 13 using resin molding, tooling plastics (polycarbonate, Po
Liamide , polyacetal, polyphenylene oxai
, Polyethylene terephthalate, polybutylene terephthalate
(Talate, etc.) alone, or additives (silica, wood powder, calcium carbonate ) to improve rigidity, thermal properties, curing shrinkage, etc.
Resins , glass fibers , metal powders, etc., or liquid crystal polymers, which have recently been in the spotlight.
On the other hand, when a metal or alloy is used, metals such as Al and Cu or alloys thereof can be widely used. Because the base 13 placed in this center is enough to form a reflecting mirror surface.
Large area and accurate positioning and mounting on the rotor.
Has a sufficient area, the rotating shaft can be fixed, and it is balanced when rotating.
There is a volume and weight that can be taken accurately, and there is no centrifugal force during rotation.
Rigid enough to withstand any external force and hold the resin layer / reflection film
To reduce the influence of heat from the motor side on the resin layer / reflection film.
The surface processing accuracy and the surface processing easiness do not matter so much.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

When the resin is formed in multiple layers, since the resin is cured on the resin, the adhesive force between the resin and the resin is the adhesive force between the cured resin and the glass plate for transfer or the mold surface. It is necessary to make the resin film on the base side satisfactorily, but the resin generally has better adhesion to the inorganic material such as glass and metal than the resin surface, and the transfer plate side It is unstable just to apply a release agent to the. Therefore, the resin cured surface from the first layer to the (n-1) th layer should have a certain degree of surface roughness, and the adhesion with the resin layer formed thereon can be physically improved. It becomes effective. It is meaningless that the flatness becomes worse than before the resin film is formed by increasing the surface roughness, but the roughness for physically improving the adhesive strength is about Rmax 0.3 μm or more.
Is effective, by using those uniformly surface roughness by etching, polishing or the like the ones flatness favorable as transfer plate used in the first layer to the (n-1) th layer and the large It is possible to control the surface roughness to a constant value while improving the flatness of the base with poor accuracy. Since the resin surface on the outermost periphery serves as a reflection surface, the transfer plate is a glass plate or a mold surface with good flatness and surface roughness.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

FIG. 3 shows details of the process in which the flatness is improved by forming the resin layers into multiple layers. In general, a photo-curing resin has a curing shrinkage of about 5 to 20%, and in FIG. 3, a resin having a shrinkage of 10% is used as an example for a base having a layer thickness of 50 μm and a surface step of 50 μm. Has become. Since the surface difference of the base is 50 μm, the film thickness of the applied resin has a maximum difference of 50 μm, but when this is cured with a shrinkage of 10%, the flatness on the base side of the first layer is within 5 μm. Therefore, in the second layer, the maximum film thickness difference of the applied resin is 5 μm, and when this is cured, a surface having a flatness within 0.5 μm is formed. Similarly, in the third outermost layer, a flatness of about 0.05 μm can be achieved if the flatness of the transfer plate is good. If there is only one resin layer, the surface step of the base will be
When the resin is large and hardens with shrinkage, the transferability is limited. However, by using multiple layers, it is possible to perform transfer with extremely high precision. Since the required accuracy as the mirror surface of the rotating mirror is covered by the resin multilayer film, the base lower surface of the base is not required to have high accuracy, and therefore, the requirements for the material and the manufacturing method of the base are lenient. However, although it does not always follow the above calculation,
The actual effect of the multi-layer coating will be shown in the description of FIG. 5 described later.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

FIG. 1 is a partially cutaway perspective view showing the structure of a rotary six-sided mirror according to an embodiment of the present invention.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

FIG. 6 is a schematic view of an optical system of a conventional laser beam printer.
Diagram showing the schematic configuration

Claims (2)

[Claims] 1. A rotating mirror having at least one reflecting mirror surface, wherein a plurality of resin film layers are formed on at least a part of a peripheral surface of a base having a columnar or polygonal columnar portion, A rotating mirror formed by forming a thin film having a high light reflectance on this multilayer resin film. 2. A method of manufacturing a rotary mirror, wherein in the process of forming a plurality of resinous film layers in the rotary mirror, the surface roughness is Rmax of 0.3 μm or more at the time of formation except for the resin layer from the base side to the outermost circumference. .