JP2010175996A - Optical scanning apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical scanning apparatus which solves various problems involved in wide image angle due to miniaturization and which achieves the miniaturization and low price. <P>SOLUTION: Two incident optical systems each including light sources 1 and 1b, are disposed substantially symmetrically with respect to a plane (subscanning cross section) which includes the rotary axis of a polygon mirror 5 and is parallel to a main scanning direction. Between the two incident optical systems, a synchronization optical system composed of a synchronization lens 10 and a synchronization detection unit 11 is arranged and a light shielding member 12 which shields counter flare light is disposed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical scanning device (including the concept of an optical writing device) and an image forming apparatus such as a copier, a printer, a facsimile machine, a plotter having the optical scanning device, and a multifunction machine including at least one of them.

Conventionally, optical scanning devices are widely known in connection with image forming apparatuses such as optical printers, digital copying machines, and optical plotters. Is required.
In order to reduce the size of the optical scanning device, it is required to increase the angle of view of the scanning optical system by shortening the optical path length. However, the synchronous optical system indispensable for optical scanning must be housed in a miniaturized optical scanning apparatus.

Japanese Patent Application Laid-Open No. 2004-228561 describes a scanning light beam passing portion provided at the end of the scanning lens in the main scanning direction, and the synchronizing light flux passage portion having a parallel plate shape in the main scanning direction and a cylindrical lens shape in the sub scanning direction. Yes.
However, in the optical scanning device having a wide angle of view as the object of the present invention, the synchronous light beam is incident on the synchronous light beam passage portion at a very large incident angle. The following problems arise.
(1) The aberration of the sync beam becomes large and interferes with the sync detection function. (2) The sync beam passing part becomes too large in the main scanning direction, and the scanning lens becomes large and interferes with the incident optical system.

Patent Document 2 describes a synchronous optical system in which a synchronous mirror and a synchronous detection element are conjugated in a sub-scan section. In this regard, the wide-angle scanning optical system has a problem similar to that of Patent Document 1. Further, the invention described in Patent Document 2 has a problem that the optical path of the synchronous optical system becomes long and is not suitable for miniaturization.
Patent Document 3 describes a configuration in which one synchronization detection unit is shared in a plurality of optical scanning configurations. Although price reduction and miniaturization can be expected, there is no suggestion for the problem of the present invention to be described later regarding the arrangement position of the synchronization detector.

  Patent Document 4 describes a configuration in which a notch portion is provided at the end of the scanning lens in the main scanning direction so that the synchronous light beam does not pass through the scanning lens and is not affected by the expansion and contraction of the scanning lens. Yes. Although this method can be expected to be downsized, a special processing must be applied to the outer shape of the scanning lens, which is not suitable for lowering the price.

In widening the angle of view of the scanning optical system by downsizing the optical scanning device, the layout of the synchronous optical system becomes difficult. If the synchronous optical system is forcibly changed, miniaturization will be hindered, and if a mirror required for folding will be provided, cost reduction will be hindered.
If a method in which the synchronous light beam passes through the scanning lens is taken, it is inevitable that the scanning lens becomes large. In addition, the aberration of the synchronous optical system increases due to the sudden incidence angle due to a wide angle of view.
The wide angle of view results in a layout in which the “opposed flare” in which the reflected light of one scanning optical system enters the opposing scanning optical system and becomes ghost light is likely to occur.

  The present invention has been made in view of such a current situation, and provides an optical scanning device that can solve the above-mentioned problems associated with widening the angle of view due to compactness, and that can achieve downsizing and cost reduction. Main purpose.

  In order to achieve the above object, according to the first aspect of the present invention, the light beam emitted from the light source is guided to the optical deflector, and the light beam is formed as a long line image in the main scanning direction on the optical deflector reflection surface. A plurality of incident optical systems, a single optical deflector on which a plurality of light beams guided by the plurality of incident optical systems are incident, and a plurality of light beams deflected by the optical deflectors to be guided to a plurality of scanned surfaces and imaged In an optical scanning device having a scanning optical system and a synchronous optical system for determining a writing timing to the surface to be scanned, a plurality of incident optical systems include a rotation axis of the optical deflector and a main scanning direction And each incident optical system includes a rotation axis of the optical deflector and includes a rotation axis of the optical deflector, and is linear with an angle with respect to the sub-scanning section parallel to the main-scanning direction. The scanning optics comprising a plurality of optical elements arranged The writing range in the main scanning direction on the scanned surface is longer than the optical distance connecting the reflection point of the optical deflector to the center of the scanned surface, and the synchronous optical system includes a synchronous lens And a synchronous beam detecting element, wherein the synchronous optical system is located between the plurality of incident optical systems.

According to a second aspect of the present invention, in the optical scanning device according to the first aspect, a light shielding member is provided between the plurality of incident optical systems together with the synchronous optical system.
According to a third aspect of the present invention, in the optical scanning device according to the second aspect, the synchronous optical system is a single unit for a plurality of optical scanning configurations including the plurality of incident optical systems and the plurality of scanning optical systems. It is characterized by being.

According to a fourth aspect of the present invention, in the optical scanning device according to the first or second aspect, two synchronous optical systems are provided between two incident optical systems facing each other with respect to the optical deflector. To do.
According to a fifth aspect of the present invention, in the optical scanning device according to the fourth aspect, the two synchronization optical systems share the synchronization lens or the synchronization detection element.

According to a sixth aspect of the present invention, in the optical scanning device according to any one of the first to fifth aspects, the plurality of incident optical systems and a plurality of objects positioned on opposite sides of the optical deflector. A plurality of optical scanning configurations composed of the plurality of scanning optical systems for scanning a scanning plane are overlapped in the rotation axis direction of the optical deflector.
According to a seventh aspect of the present invention, in the optical scanning device according to any one of the first to sixth aspects, the optical deflector is a polygon mirror.

According to an eighth aspect of the present invention, in the optical scanning device according to any one of the first to seventh aspects, the synchronization detecting element and a reflection surface of the optical deflector in the synchronous optical system are within a sub-scanning section. It is conjugate.
According to the ninth aspect of the present invention, a plurality of photosensitive image carriers are optically scanned by an optical scanning device to form a latent image corresponding to each color, and the latent image is visualized by a developing unit to be a color image. In the image forming apparatus for obtaining the above, the optical scanning device according to any one of claims 1 to 8 is used as the optical scanning device.

  According to the present invention, various problems associated with widening the angle of view due to compactness can be solved, and miniaturization and cost reduction can be realized.

It is a schematic block diagram in the main scanning cross section of the optical scanning device which concerns on the 1st Embodiment of this invention. It is a schematic block diagram in the main scanning cross section of the optical scanning device which concerns on 2nd Embodiment. It is a schematic block diagram in the main scanning cross section of the optical scanning device which concerns on 3rd Embodiment. It is a schematic block diagram in the main scanning cross section of the optical scanning device which concerns on 4th Embodiment. It is a schematic block diagram of the image forming apparatus which concerns on 5th Embodiment. It is a schematic block diagram of the image forming apparatus which concerns on 6th Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
First, a first embodiment will be described with reference to FIG. FIG. 1 shows the main part of an optical scanning device of the opposite scanning system embodying the present invention. The paper surface (plane) in FIG. 1 corresponds to the main scanning section.
A plurality of light beams emitted from the light source 1 which is a semiconductor laser are coupled to a subsequent optical system by a coupling lens 2. The light source 1 may be a semiconductor laser array or a VCSEL having a plurality of light emitting points.
When the light beam that has passed through the coupling lens 2 passes through the opening of the aperture 3, the light beam peripheral portion is blocked and shaped, and enters the cylindrical lens 4. The cylindrical lens 4 focuses the incident light beam in the sub-scanning direction, and condenses it as a long line image in the main scanning direction in the vicinity of the deflection reflection surface of the polygon mirror 5 that is an optical deflector.
The cylindrical lens 4 may be provided with a diffractive surface having a power for correcting fluctuation due to temperature of the scanning optical system.

The light source 1, the coupling lens 2, the aperture 3, and the cylindrical lens 4 are optical elements that constitute one incident optical system.
The light source 1b, the coupling lens 2b, the aperture 3b, and the cylindrical lens 4b are optical elements that constitute another incident optical system.
Therefore, this embodiment has a plurality (two in this case) of incident optical systems.
These incident optical systems are arranged so as to be substantially symmetric with respect to a plane (sub-scanning cross section) including the rotation axis of the polygon mirror 5 and parallel to the main scanning direction. In other words, the two incident optical systems are arranged symmetrically with respect to the line M passing through the rotation axis of the polygon mirror 5 in the main scanning section. A sub-scan section is obtained by continuing the line M in the thickness direction of the paper surface of FIG.
The line M is parallel to the main scanning direction (the direction in which the scanned surface 8 to be described later extends).
The plurality of optical elements constituting each incident optical system are arranged in a straight line having an angle with respect to the sub-scanning section in the main scanning section.
The incident optical system may be bent in the sub-scanning direction by a mirror or the like due to layout requirements.
A plurality of incident optical systems may exist for one scanning optical system.

The light beam reflected by the deflecting and reflecting surface of the polygon mirror 5 passes through the scanning lens system 6 constituting the scanning optical system while being deflected at a constant angular velocity as the polygon mirror 5 rotates at a constant speed. In FIG. 1, the scanning optical system is depicted on the same plane, but the optical path is actually bent by a folding mirror 7 that bends the optical path in the thickness direction of the paper in order to guide the light beam to the surface to be scanned.
The light beam whose optical path is bent by the bending mirror 7 is condensed as a beam spot on the photoconductive photosensitive member 8 which is the substance of the surface to be scanned, and the surface to be scanned is optically scanned. Here, the scanning lens system 6 has a single lens configuration.
The writing range S in the main scanning direction on the surface to be scanned 8 is longer than the optical distance L connecting the center of the surface to be scanned 8 from the reflection point of the polygon mirror 5, and the wide angle of view is configured. .
Prior to optical scanning of the photoconductor 8, the deflected light beam is condensed in the main scanning direction by the synchronization lens 10 on the synchronization detection unit 11. Based on the output of the synchronization detector 11, the write start timing of optical scanning is determined.
In the present embodiment, the synchronization lens 10 forming the synchronization optical system and the synchronization detection unit 11 serving as a synchronization detection element include an incident optical system of the light source 1 to the polygon mirror 5 and another incident optical system of the light source 1b to the polygon mirror 5. It is provided between the system b.

When a plurality of incident optical systems and scanning optical systems use a common optical deflector, the writing timing of all scanning optical systems is easily correlated. Accordingly, it is sufficient that at least one writing timing is detected over a plurality of optical scanning devices (optical scanning configurations). This is because a scanning optical system that does not perform synchronization detection can be analogized by calculation using a synchronization detection signal.
If there are multiple synchronous optical systems, the layout of an optical scanning device originally designed for compactness becomes difficult and the number of parts increases. A synchronous detection mechanism that does not hinder downsizing of the scanning device can be constructed.

In the present embodiment, the synchronization detector 11 as a synchronization detection element and the optical deflector reflection surface in the synchronization optical system are conjugate in the sub-scan section.
Since the synchronous optical system of this embodiment stores the synchronous optical system in a region sandwiched between a plurality of incident optical systems, a light guide element such as a synchronous mirror is not necessary.
In addition, since the light is already condensed in the sub-scanning direction on the light deflector reflecting surface by the incident optical system, the optical deflector reflecting surface is automatically formed by using an optical system that focuses on the synchronization detecting element by the synchronization lens. The synchronous detection element is conjugate within the sub-scan section.
One of the problems of synchronization detection is that the synchronization light beam condensing position is shifted in the sub-scanning direction with respect to the synchronization detection element, and normal synchronization detection cannot be performed. Synchronous beam sub-scanning position shift due to manufacturing error is optically corrected.

Between these incident optical systems, a light shielding member 12 is provided together with the synchronous optical system, and the opposing flare lights 13 and 13b are shielded on both sides.
The light shielding member 12 is provided between the incident optical system b (light source 1b to polygon mirror 5) and the synchronous optical system in FIG. 1, but the place where the synchronous light beam reaches the synchronous detection unit 11 and can shield the opposing flares 13 and 13b. If so, it may be disposed anywhere in the region sandwiched between the two incident optical systems in FIG.
When the scanning optical system is a counter scanning method in which the optical deflector is opposed to the scanning optical system, the scanning lens surface reflection component of the light beam enters the opposing scanning optical system, and the surface to be scanned may be exposed as it is ( Referred to herein as “opposing flare”).
Since this problem is more likely to occur as the wide-angle scanning optical system is used, a member that shields the opposing flare is required. From this viewpoint, the light shielding member 12 is provided.
The light shielding member 12 is preferably installed in a region “between a plurality of incident optical systems” where the synchronous optical system is disposed.

The layout according to the present embodiment also has an advantage that the substrate for driving the light source and the substrate for performing synchronous detection can be integrated as shown by reference numeral 9 in FIG.
According to the present embodiment, in an optical scanning device having a scanning optical system with a wide angle of view accompanying downsizing, synchronization detection can be performed without impairing the compactness.

A plurality of optical scanning configurations comprising a plurality of incident optical systems and a plurality of scanning optical systems for scanning a plurality of scanned surfaces located on opposite sides across the optical deflector are arranged in the direction of the rotation axis of the optical deflector. It can also be set as the structure which overlaps.
In this way, writing can be performed on three or more scanned surfaces. It is also suitable when the writing timing of another scanning optical system is predicted by signal calculation, such as a configuration in which a single synchronous optical system is used.
There are various optical deflectors such as a polygon mirror, a micro mirror, and a galvanometer mirror, and a polygon mirror is suitable for performing optical deflection on a plurality of scanning optical systems facing each other.
In particular, as described above, with respect to a configuration in which a plurality of optical scanning configurations are overlapped in the rotation axis direction of the optical deflector, the polygon mirror is overlapped in the rotation axis direction (multi-stage polygon mirror) or thick in the rotation axis direction. It is preferable because it can be processed.

A second embodiment will be described with reference to FIG. Note that the same parts as those in the above embodiment are denoted by the same reference numerals, and unless otherwise specified, description of the configuration and functions already described is omitted, and only the main part will be described (the same applies to other embodiments below).
As shown in FIG. 2, in the present embodiment, a plurality (here, two) of synchronous optical systems are provided, and the scanning start end and the scanning end end of two opposing optical scanning devices (optical scanning configurations), respectively. Shows how to detect synchronization.
Each synchronization optical system includes two synchronization lenses 10 and one synchronization detection unit 11 corresponding to each optical scanning configuration, and the synchronization detection unit 11 is shared by the two synchronization optical systems. In some cases, the synchronization detection unit 11 may be provided for each synchronization optical system.
The actual synchronization detection signal is affected by manufacturing errors and temporal variations of the scanning lens and other optical scanning devices. Therefore, if the synchronization detection element is performed only at the scanning start end, the number of parts can be reduced, but it cannot be corrected if the above error occurs.
Here, in the two scanning optical systems facing each other, one can perform synchronization detection at the scanning start end and the other at the scanning end end, so that synchronization detection accuracy can be improved.
The light shielding member 12 is disposed between the two synchronous optical systems.

In the configuration in which the synchronization optical system is individually provided corresponding to each light scanning configuration, as shown in FIG. 3, it is composed of one synchronization lens 10 having a region corresponding to each light scanning configuration and one synchronization detection unit 11. In this manner, the two synchronization optical systems may share the synchronization lens 10 and the synchronization detection unit 11 (third embodiment).
Increasing the number of synchronization optical systems as described above is effective for improving the synchronization detection accuracy, but it becomes an impediment to cost reduction and size reduction. In the present embodiment, the synchronization detection accuracy is improved without increasing the number of parts by sharing the optical elements of the plurality of synchronization optical systems. At the same time, the convenience of layout is improved and downsizing is not hindered.
In the present embodiment, the light blocking member 12 is disposed between the optical paths of the synchronous light fluxes of the respective synchronous optical systems.
In the example shown in FIG. 2 and FIG. 3, the light shielding member 12 that prevents the opposing flare is provided in the region sandwiched between the two synchronous optical systems, but if the region is sandwiched between the two incident optical systems, As shown in FIG. 4, it may be provided in a region sandwiched between one synchronous optical system and one incident optical system closer thereto (fourth embodiment).
In any case, since the region sandwiched between the scanning optical system and the incident optical system is extremely narrow in the facing wide field angle scanning optical system, the object of the present invention is achieved.

FIG. 5 shows a fifth embodiment (image forming apparatus).
A laser printer 1000 as an image forming apparatus has a “photoconductive photosensitive member formed in a cylindrical shape” as a photosensitive image carrier 1110. Around the image carrier 1110, a charging roller 1121 as a charging unit, a developing device 1131 as a developing unit, a transfer roller 1141, and a cleaning device 1115 are provided. A “corona charger” can also be used as the charging means.
An optical scanning device 1171 that performs optical scanning with the laser beam LB is provided, and “exposure by optical writing” is performed between the charging roller 1121 and the developing device 1131.
In FIG. 5, reference numeral 1161 denotes a fixing device, reference numeral 1181 denotes a paper feeding cassette, reference numeral 1191 denotes a registration roller pair, reference numeral 1201 denotes a paper feeding roller, reference numeral 1211 denotes a conveyance path, reference numeral 1221 denotes a paper discharge roller pair, and reference numeral 1231 denotes paper discharge. A tray and a symbol P indicate transfer paper as a sheet-like recording medium.

When image formation is performed, the image carrier 1110 that is a photoconductive photosensitive member is rotated at a constant speed in the clockwise direction, the surface thereof is uniformly charged by the charging roller 1121, and the optical beam of the laser beam LB of the optical scanning device 1171 is written. An electrostatic latent image is formed upon exposure to the image. The formed electrostatic latent image is a so-called “negative latent image”, and the image portion is exposed.
This electrostatic latent image is reversely developed by the developing device 1131, and a toner image is formed on the image carrier 1110. The paper feed cassette 1181 storing the transfer paper P is detachable from the main body of the image forming apparatus 1000. When the transfer paper P is loaded as shown in FIG. The fed transfer paper P is fed to the registration roller pair 1191 at the leading end. The registration roller pair 1191 feeds the transfer paper P to the transfer unit in time with the toner image on the image carrier 1110 moving to the transfer position.

The transferred transfer paper P is superimposed on the toner image at the transfer portion, and the toner image is electrostatically transferred by the action of the transfer roller 1141. The transfer paper P to which the toner image has been transferred is sent to the fixing device 1161, where the toner image is fixed by the fixing device 1161, passes through the conveyance path 1211, and is discharged onto the tray 1231 by the discharge roller pair 1221.
The surface of the image carrier 1110 after the toner image has been transferred is cleaned by a cleaning device 1115 to remove residual toner, paper dust, and the like.
By using the above-described optical scanning device of the present invention as the optical scanning device 1171, it is possible to form a good image.
In the present embodiment, the number of photosensitive members is one. However, by providing a plurality of incident optical systems in the optical scanning device 1171 and using the multi-beam method, the advantages of the present invention can be utilized.

Various photosensitive image carriers can be used. For example, a silver salt film can be used as the image carrier. In this case, a latent image is formed by writing by optical scanning, and this latent image can be visualized by processing by a normal silver salt photographic process. Such an image forming apparatus can be implemented as an optical plate making apparatus or an optical drawing apparatus that draws a CT scan image or the like.
As the photosensitive image carrier, it is also possible to use a color developing medium (positive printing paper) that develops color by the thermal energy of the beam spot during optical scanning. In this case, a visible image is directly formed by optical scanning. it can.
As the photosensitive image bearing member, a photoconductive photosensitive member can also be used. As the photoconductive photoreceptor, a sheet-like one such as zinc oxide paper can be used, or a selenium photoreceptor, an organic optical semiconductor, or the like that is repeatedly used in the form of a drum or a belt can be used. .

When a photoconductive photoconductor is used as an image carrier, an electrostatic latent image is formed by uniform charging of the photoconductor and optical scanning by an optical scanning device. The electrostatic latent image is visualized as a toner image by development. The toner image is directly fixed on the photoconductor when the photoconductor is in the form of a sheet such as zinc oxide paper, and transfer paper or an OHP sheet when the photoconductor can be used repeatedly. It is transferred and fixed on a sheet-like recording medium such as (plastic sheet for overhead projector).
The transfer of the toner image from the photoconductive photosensitive member to the sheet-like recording medium may be directly transferred from the photosensitive member to the sheet-like recording medium (direct transfer method), or may be temporarily transferred from the photosensitive member to an intermediate transfer belt or the like. After transfer to the intermediate transfer medium, transfer from the intermediate transfer medium to a sheet-like recording medium (intermediate transfer method) may be performed.
Such an image forming apparatus can be implemented as an optical printer, an optical plotter, a digital copying apparatus, or the like.
In addition, as exemplified below, the image forming apparatus according to the present invention includes a plurality of the photoconductors arranged along the conveyance path of the sheet-like recording medium, and a plurality of optical scanning devices are used for each photoconductor. To implement as a tandem type image forming apparatus that forms an electrostatic latent image and transfers and fixes a toner image obtained by visualizing the latent image onto the same sheet-like recording medium to obtain a color image or a multicolor image synthetically Can do.

FIG. 6 shows a sixth embodiment (multicolor image forming apparatus).
In FIG. 6, photoconductors 1Y, 1M, 1C, and 1K as image carriers rotate in the direction of the arrow, and around them, chargers 2Y, 2M, 2C, and 2K, developing devices 4Y, 4M, 4C, 4K, transfer charging means 6Y, 6M, 6C, 6K and cleaning means 5Y, 5M, 5C, 5K are provided. Y represents yellow, M represents magenta, C represents cyan, and K represents black.
The chargers 2Y, 2M, 2C, and 2K are charging members that constitute a charging device for uniformly charging the surface of the photoreceptor. The surface of the photosensitive member between the charging member and the developing devices 4Y, 4M, 4C, and 4K is irradiated with a beam by a writing unit (optical scanning device) so that an electrostatic latent image is formed on the photosensitive member. Based on the electrostatic latent image, a toner image is formed on the surface of the photoreceptor by the developing device. Further, the transfer toner images of the respective colors are sequentially transferred onto the recording paper (not shown) conveyed on the conveyance belt of the transfer conveyance device 80 by the transfer charging units 6Y, 6M, 6C, and 6K, and finally recorded by the fixing unit 30. The image is fixed on the trial.
Also in the present embodiment, by using the above-described optical scanning device of the present invention as the optical scanning device 20, it is possible to form a good image.

  According to the present invention, it is possible to realize a highly stable optical scanning device while simultaneously reducing the number of parts associated with the enhancement of the functionality of the optical scanning device and the realization of various types of optical scanning devices. As a result, the amount of material used in the production of the optical scanning device can be reduced, leading to a reduction in the environmental burden with respect to the amount of mined resources and the amount of plastic waste discharged.

DESCRIPTION OF SYMBOLS 1 Light source 1Y, 1M, 1C, 1K Image carrier 5 Polygon mirror as optical deflector 8 Surface to be scanned 10 Synchronous lens 11 Synchronous light beam detection element 20, 1171 Optical scanning device

Japanese Patent Laid-Open No. 10-010445 JP 2007-248626 A JP-A-4-313776 JP 2002-089921 A

Claims (9)

A plurality of incident optical systems that guide the light beam emitted from the light source to the optical deflector and form the light beam as a long line image in the main scanning direction on the optical deflector reflection surface;
A single optical deflector on which a plurality of light beams guided by a plurality of incident optical systems are incident;
A plurality of scanning optical systems for guiding the light beams deflected by the optical deflector to a plurality of scanned surfaces and forming images; and
In the optical scanning device having a synchronous optical system for determining the writing timing to the surface to be scanned,
The plurality of incident optical systems are arranged substantially symmetrically with respect to the sub-scanning section parallel to the main scanning direction including the rotation axis of the optical deflector, and each incident optical system includes the rotation axis of the optical deflector. It consists of a plurality of optical elements arranged in a straight line having an angle with respect to a sub-scanning section parallel to the main scanning direction,
In the scanning optical system, the writing range in the main scanning direction on the scanned surface is longer than the optical distance connecting the center of the scanned surface from the reflection point of the optical deflector,
The synchronous optical system includes a synchronous lens and a synchronous light beam detecting element,
The optical scanning device, wherein the synchronous optical system is located between the plurality of incident optical systems. The optical scanning device according to claim 1,
An optical scanning device characterized in that a light shielding member is provided between the plurality of incident optical systems together with the synchronous optical system. The optical scanning device according to claim 2.
The optical scanning apparatus characterized in that the synchronous optical system is single for a plurality of optical scanning configurations including the plurality of incident optical systems and the plurality of scanning optical systems. The optical scanning device according to claim 1 or 2,
An optical scanning device characterized in that two synchronous optical systems are provided between two incident optical systems facing each other with respect to the optical deflector. The optical scanning device according to claim 4.
The optical scanning apparatus characterized in that the two synchronous optical systems share the synchronous lens or the synchronous detection element. In the optical scanning device according to any one of claims 1 to 5,
An optical scanning configuration comprising the plurality of scanning optical systems for scanning the plurality of incident optical systems and a plurality of scanned surfaces located on opposite sides across the optical deflector is a rotation of the optical deflector. An optical scanning device characterized by being overlapped in the axial direction. In the optical scanning device according to any one of claims 1 to 6,
The optical scanner is characterized in that the optical deflector is a polygon mirror. In the optical scanning device according to any one of claims 1 to 7,
The optical scanning device characterized in that the synchronous detector and the reflecting surface of the optical deflector in the synchronous optical system are conjugate in the sub-scan section. In an image forming apparatus for forming a latent image corresponding to each color by performing optical scanning with an optical scanning device on a plurality of photosensitive image carriers, and visualizing the latent image with a developing unit to obtain a color image.
An image forming apparatus using the optical scanning device according to claim 1 as the optical scanning device.

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