JP2002318362A - Optical scanner and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanner and an image forming device by which an image quality is improved by making a dividing boundary inconspicuous. SOLUTION: This optical scanner possesses a light emission source, a supporting base body by which a plurality of optical scanning modules each having a deflector to deflect a light beam from the light emission source are arrayed and supported in a main scanning direction and a housing to respectively position and support a plurality of pieces of image formation means to form an image with the light beam with which scanning is performed by the deflector corresponding to each optical scanning module on a surface to be scanned and to support the supporting base body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning apparatus and an image forming apparatus, and more particularly to an optical scanning apparatus used in a writing system of an image forming apparatus such as a digital copying machine and a laser printer.

[0002]

2. Description of the Related Art Conventionally, when an optical scanner is used to expose a wide area of a photoreceptor, optical components such as a polygon mirror and a scanning lens are enlarged, and component accuracy is required to maintain high image quality. Is done. Therefore, Japanese Patent Laid-Open No.
No. 78 (hereinafter referred to as Conventional Example 1) and JP-A-2000-1
As disclosed in Japanese Patent No. 9438 (hereinafter referred to as Conventional Example 2), there is a method in which an exposure range of a photoconductor is divided and a small optical scanning device is provided in each of the divided portions to perform scanning exposure.

[0003]

However, in the above-described conventional system, the number of components is increased due to the provision of a plurality of optical scanning devices, the production efficiency is poor, and the scanning line positions between the optical scanning devices are accurately adjusted. Otherwise, there is a drawback that the division boundary becomes conspicuous and image quality deteriorates.

An object of the present invention is to solve these problems, and an object of the present invention is to provide an optical scanning device and an image forming apparatus that can make the division boundaries less noticeable and improve the image quality.

[0005]

In order to solve the above-mentioned problems, an optical scanning apparatus according to the present invention comprises a light-emitting source and an optical scanning module having a deflector for deflecting a light beam from the light-emitting source. A plurality of imaging means for imaging a light beam scanned by a deflector corresponding to each optical scanning module on a surface to be scanned; And a housing for supporting the base. Therefore, since each optical scanning module and each imaging unit are supported in common, the accuracy of the relative arrangement is maintained, the scanning position deviation at the division boundary can be reduced, and high-quality image formation can be performed. In addition, the number of parts can be reduced and productivity can be improved.

Further, since all of the optical scanning modules are arranged and supported on the same surface of the supporting base, even if the supporting base is inclined or the like, all the optical scanning modules change their postures integrally. Even if there is an absolute shift in the emission direction, no relative shift occurs, the scan position shift at the division boundary can be reduced, and high-quality image formation can be performed.

Further, the housing has a positioning portion for abutting and positioning the mounting surface on which the optical scanning modules are arranged, so that the reference surface on which the optical scanning module is mounted and the positioning portion are the same, and the housing is connected to the optical scanning module. Accuracy of relative position with respect to the image means can be ensured, scanning position deviation at the division boundary can be reduced, and high quality image formation can be performed.

An image forming apparatus according to another aspect of the present invention includes:
It is characterized in that one line of image data is divided into the number of unit modules and image recording is performed on an image forming unit that forms a single color image.

Further, an image forming apparatus according to another invention includes:
It is characterized in that it is provided in each of the image forming units for each color for forming a full-color image, and performs image recording individually using image data corresponding to each color.

An image forming apparatus according to another aspect of the present invention includes:
It is characterized in that it is commonly used for the image forming units for each color for forming a full-color image, and that image recording is performed in chronological order using image data corresponding to each color.

Further, an image forming apparatus according to another aspect of the present invention includes:
It is characterized in that the image forming unit for each color forming a full-color image is commonly used for one or a plurality of colors, and that image recording is performed in a time series with image data corresponding to each color.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical scanning device according to the present invention comprises a light-emitting source and a supporting base for supporting a plurality of optical scanning modules having a deflector for deflecting a light beam from the light-emitting source in the main scanning direction. A plurality of image forming means for forming an image of a light beam scanned by a deflector corresponding to each optical scanning module on a surface to be scanned, and supporting the image forming means;

[0013]

FIG. 1 is an exploded perspective view showing the structure of an optical scanning module in an optical scanning device according to the present invention. In FIG. 1, a casing 101 made of aluminum die-casting includes a bearing 102 into which a sleeve for supporting a shaft of a polygon motor is press-fitted, and a coupling lens 10 for converting a light beam from a semiconductor laser 106 into a substantially parallel light beam.
3, and a cylinder lens 10 having a curvature in the sub-scanning direction
A V-shaped groove 105 for holding the cylindrical surface of No. 4 is integrally formed. A fitting hole 117 for press-fitting and holding the semiconductor laser 106 is provided on a side wall of the light source holding member 116. The coupling lens 103 has a V-shaped groove 105
, The light emitting point of the semiconductor laser 106 can be aligned with the axis in a plane orthogonal to the optical axis, and the position is adjusted by adjusting in the direction of the groove to adhere. In this embodiment, the cylinder lens 104 is similarly supported by having the same outer diameter. The light beam emitted from the semiconductor laser 106 is reflected by the triangular prism-shaped reflecting mirror 118 positioned on the casing 101 via the coupling lens 103 and the cylinder lens 104, and converges linearly on the polygon mirror 107 in the sub-scanning direction. And is deflected. The deflected light beam is reflected by a triangular prism-shaped reflecting mirror 108 positioned on the casing 101 and emitted upward at a predetermined angle with respect to the scanning plane. The coil unit 109 for driving the polygon motor is formed by laminating annular silicon plywood, winding each of a plurality of inwardly projecting projections to form a coil 110, and a recess provided concentrically with the bearing 102. 111. The polygon mirror 107 is a mirror-finished aluminum plate end face. In this embodiment, five polygon mirrors are held by the mirror holding unit 112. A shaft 113 is press-fitted into the mirror holding unit 112 and an annular magnet 114 is joined to form a rotor unit. The magnets 114 are magnetized with S and N poles alternately in the circumferential direction, and are arranged to face the inside of the plurality of coils 110 so as to be opposed to each other.
07 rotates.

FIG. 2 is an exploded perspective view showing the configuration of another optical scanning module in the optical scanning device according to the present invention. In the figure, a plurality of bearing holding members 2
02 are arranged. Since the image forming means and the housing in FIG. 1 are the same, the description is omitted. The bearing holding member 202 has a flange shape, and the lower surface of the flange portion is fixed by abutting the substrate surface, and a sleeve for supporting the shaft of the polygon motor is press-fitted at the center to form the bearing 204. The coil for driving the polygon motor is formed by laminating a winding pattern 203 formed of a thin film on an electric board 201, and circuit-wiring is arranged concentrically with the bearing 204.
The L-shaped light source holding member 205 is formed of resin, and has a V-shape that holds a cylindrical surface of a coupling lens 206 and a cylindrical lens 207 having a curvature in the sub-scanning direction, with the light beam of the semiconductor laser 209 being a substantially parallel light beam. Groove 208
Are integrally formed. Also, the light source holding member 205
A fitting hole 219 for press-fitting and holding the semiconductor laser 209 is provided on a side wall of the device, and a projection 216 protruding from the lower surface is engaged with and supported by the fitting hole 217 on the surface of the electrical board 201.
The light beam emitted from the semiconductor laser 209 enters the polygon mirror 210 via the coupling lens 206 and the cylinder lens 207. The light beam deflected by the polygon mirror 210 is reflected by a triangular prism-shaped reflecting mirror 211 directly bonded onto the electrical board 201, and is emitted upward at a predetermined angle with respect to the scanning plane. In addition, the reflection mirror 2
The sub-scanning position and the inclination of each scanning line can also be adjusted by moving and adjusting 11 on the ground plane. In addition, the polygon mirror 210 is a mirror-finished aluminum plate end face. In this embodiment, five faces are held by the mirror holding unit 213. The shaft 214 is press-fitted into the mirror holding portion 213 and an annular magnet 215 is joined to form a rotor portion. The magnet 215 is alternately S in the circumferential direction.
The poles and the N poles are magnetized and arranged above the plurality of coils to face each other, and rotate the polygon mirror 210 by applying an AC voltage to the coils. As in the embodiment of FIG. 1, a plurality of optical scanning modules having the above-described configuration are arranged on an electrical board, and form part of a semiconductor laser drive circuit and a motor drive circuit. The cable 218 is a cable for wiring the lead terminals of the semiconductor laser 209 and the electrodes. In each of the embodiments, a polygon mirror is used as a rotating mirror, but a galvano mirror or the like that reciprocates a single mirror may be used instead of the polygon mirror.

FIG. 3 is an exploded perspective view showing the configuration of another optical scanning module in the optical scanning device according to the present invention. The embodiment shown in the drawing uses a semiconductor resonance mirror as an embodiment using a galvanometer mirror. In the figure, a plurality of semiconductor resonance mirror holding members 405 are arranged on an electric board 201. Since the image forming means and the housing in FIG. 1 are the same, the description is omitted. The semiconductor resonance mirror holding member 405 is formed in a box shape of ceramic or the like, and a lead wire 407 is provided to penetrate the bottom surface, and the semiconductor resonance mirror is mounted at the center thereof. The semiconductor resonance mirror is formed by forming a vibrator 402 that penetrates a silicon substrate 403 by etching and is supported by a pair of torsion bars 404. A mirror is formed by a metal film at the center of the vibrator, and a winding is patterned so as to surround the mirror. One end of the lead wire 407 is soldered to a through hole of the electrical board 201, the other end is connected to a land formed on the silicon substrate 403 by wire bonding, and an alternating current is applied to the winding pattern through a torsion bar 404. You. Permanent magnets 406 are arranged outside the semiconductor resonance mirror symmetrically with the torsion bar 404 interposed therebetween. The vibrator 402 generates Lorentz force due to the magnetic field and the current flowing through the winding pattern, and rotates reciprocally with the torsion bar 404 as a rotation axis. When the frequency of the alternating current approaches the natural frequency of the vibrator, the vibrator enters a resonance state, the rotation angle is enlarged, and a stable amplitude is obtained. The L-shaped light source holding member 405 is formed of a resin, and the coupling lens 406 converts the light beam of the semiconductor laser 409 into a substantially parallel light beam.
A groove 408 for holding the cylindrical surface of the cylinder lens 407 having a curvature in the sub-scanning direction is integrally formed.
The semiconductor laser 40 is provided on the side wall of the light source holding member 405.
A fitting hole for press-fitting and holding 9 is provided, and a projection 416 protruding from the lower surface is engaged with and supported by the fitting hole 417 on the surface of the electrical equipment board 401. The light beam emitted from the semiconductor laser 409 is coupled to the coupling lens 406 and the cylinder lens 4.
07, the light enters from the side surface of the prism joined to the frame of the silicon substrate 403, is reflected downward by the slope 411, and is incident on the semiconductor resonant mirror. The light beam deflected and scanned by the semiconductor resonance mirror is reflected upward, passes vertically through the prism, and is emitted from the upper surface 412. In this embodiment, by performing image recording in only one direction of the reciprocal scanning, writing control can be performed in the same manner as in the embodiment using the polygon mirror.

FIG. 4A is a schematic external view of an optical scanning device according to an embodiment of the present invention, and FIG. 4B is a schematic perspective view of the optical scanning device according to the present embodiment. FIG. 5 is a sectional view. 4 and 5, in the optical scanning module having the configuration shown in FIGS. 1 and 2, the contact surface formed on the lower surface of the casing in parallel with the scanning plane is grounded on the electrical component substrate 302 as a support substrate. It is fixed with screws from the back side. Although a plurality of optical scanning modules shown in FIG. 1 are arranged on the electrical board 302, the sub-scanning position and the inclination of each scanning line can be adjusted by adjusting the movement on the ground plane during fixing. An electrode for wiring the lead terminals of the semiconductor laser 106 and an electrode for wiring the windings are provided on the electrical board 302, and form part of the semiconductor laser drive circuit and the motor drive circuit, and are provided at one end in the longitudinal direction. Connector 30
In FIG. 9, wiring connections to all the optical scanning modules can be collectively performed. Cable is semiconductor laser 10
6 is a cable for wiring the lead terminals and electrodes. In the present embodiment, the main scanning is divided into a plurality of areas, and the light scanning modules are assigned to each area. In this embodiment, the number of arrays is three, but the number is not limited to three, and the number of arrays can be increased or decreased according to the recording width (paper width) of main scanning. Further, although the light beam is emitted at a predetermined angle with respect to the scanning plane using the reflection mirror, the light beam may be emitted directly without using the reflection mirror.

The light beam emitted from the optical scanning module installed as described above is scanned by two scanning lenses 304 and 30.
6, a surface 300 to be scanned such as a photosensitive drum surface
Image. In this embodiment, the scanning lens 306 is held in the beam exit window of the housing by integrally molding the lens unit for each module with resin. On the other hand, the scanning lens 304 has a strip shape in the sub-scanning direction, and is joined and arranged and fixed to a reference surface 307 provided on the housing 301. The electrical board 302 on which a plurality of optical scanning modules are provided has its upper surface abutted on a positioning surface 308 provided in an opening of the housing 301 on the side opposite to the above-mentioned exit window. Secure with screws. A mirror 305 is provided on each scanning start side, and the light beam reflected by the mirror 305 is applied to the synchronous detection sensor 3 mounted on the electrical board 302.
09, a synchronization detection signal is generated, and recording is started for each scanning line after a lapse of a predetermined time from this signal.

FIG. 6 shows a digital copying machine, FIG. 7 shows a laser printer, and FIG. 8 shows a plain paper facsimile as an image forming apparatus using the electrophotographic process equipped with the optical scanning apparatus according to the above-described embodiment. Here is an example. In FIG. 6, a digital copier main body 500 includes an optical scanning device 501, cassettes 502 and 502 ′ for accommodating sheets, and a cassette 50.
Paper feed roller 5 for taking out sheets one by one from 2,502 '
03, 503 ', a registration roller 504 for controlling the conveyance timing, a transfer charger 505, a photosensitive drum 506, a developing roller 507, and a charging roller 5
08 and other process cartridges 509
A fixing roller 510 having a built-in halogen heater,
A fixing device 511 constituted by a pressure roller;
2 and a paper discharge roller 513. In the optical scanning device 501 in the digital copying machine having such a configuration, a semiconductor laser is modulated according to an image signal.
A latent image is formed on the photosensitive drum 506 uniformly charged by the charging roller 508, and is visualized by toner supplied from the developing roller 507. On the other hand, the paper taken out by the paper feed rollers 503 and 503 ′ is conveyed by the registration roller 504 according to the timing of writing an image by the optical scanning device, and the toner image is transferred. The transferred image is fixed by a fixing roller 510 and a fixing device 511, and is conveyed by a conveying roller 512 and a discharge roller 513.
Is discharged.

In FIG. 6, a document reading device main body 6 is shown.
At 00, a document reading unit 601 fixed to a platen
Is formed on a photoelectric conversion element 603 such as a CCD via an imaging lens 602, and a mirror group 604 is moved to sequentially convert the data into electronic data. Although the digital copying machine shown in FIG. 6 is a monochrome copying machine, the invention is not limited to this. In the case of a full-color copying machine, a type in which the optical scanning device of the present invention is provided for each process cartridge for each color, a full-color image It is needless to say that the present invention can be applied to an image forming apparatus of a type provided for a single image forming unit for forming or a type comprising a plurality of image forming units.

In FIG. 7, a laser printer 700 is
Optical scanning device 701 and cassette 702 for storing paper
, A paper feed roller 703 for taking out sheets one by one from the cassette 702, a registration roller 704 for controlling the conveyance timing, a transfer charger 705, a photosensitive drum 706, a developing roller 707, a charging roller 708 and the like are integrated. The process cartridge 709 includes a fixing roller 710 having a built-in halogen heater, a fixing device 711 including a pressure roller, and a paper discharge roller 712. In the optical scanning device 701 in the laser printer 700 having such a configuration, the semiconductor laser is modulated according to an image signal from a host device, and the photosensitive drum 706 is uniformly charged by the charging roller 708.
A latent image is formed thereon, and is visualized by toner supplied from the developing roller 708. On the other hand, the sheet taken out by the sheet feeding roller 703 is conveyed by the registration roller 704 in accordance with the timing of writing an image by the optical scanning device, and the toner image is transferred. The transferred image is fixed by a fixing roller 710 and a fixing device 711, and is discharged by a discharge roller 712.

Referring to FIG. 8, a plain paper facsimile 800 is shown.
Is a light scanning device 801 and a cassette 80 for storing sheets.
2, a paper feed roller 803 for taking out sheets one by one from the cassette 802, a registration roller 804 for controlling the conveyance timing, a transfer charger 805, a photosensitive drum 806, a developing roller 807, a charging roller 808, and the like. Process cartridge 809, a fixing roller 810 having a built-in halogen heater, a fixing device 811 composed of a pressure roller, a paper feed roller 813 for taking out a document from a document table 812, and conveying the document in the sub-scanning direction. And a reading unit 816 that optically reads an image of a document. The image of the document sent from the document table 812 by the paper feed roller 813 is sequentially converted into electronic data by the reading unit 816 while being transported by the transport roller pairs 814 and 815. The plain paper facsimile 800 transmits the image signal from the reading unit 816 read as described above by a communication unit (not shown), and the semiconductor laser in the optical scanning device 801 responds to the image signal received via the communication unit. A latent image is formed on the photosensitive drum 806 which is modulated and uniformly charged by the charging roller 808,
The image is visualized by the toner supplied from the developing roller 807. On the other hand, the sheet taken out by the sheet feeding roller 803 is conveyed by the registration roller 804 in accordance with the timing of writing an image by the optical scanning device, and the toner image is transferred. The transferred image is fixed by a fixing roller 810 and a fixing device 811 and discharged.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and substitutions can be made within the scope of the claims.

[0023]

As described above, the optical scanning device of the present invention comprises a plurality of optical scanning modules having a light emitting source and a deflector for deflecting a light beam from the light emitting source arranged in the main scanning direction. A supporting base for supporting, and a housing for supporting and positioning the plurality of image forming means for imaging the light beam scanned by the deflector corresponding to each optical scanning module on the surface to be scanned, respectively. It is characterized by having. Therefore, since each optical scanning module and each imaging unit are supported in common, the accuracy of the relative arrangement is maintained, the scanning position deviation at the division boundary can be reduced, and high-quality image formation can be performed. In addition, the number of parts can be reduced and productivity can be improved.

Further, since all of the optical scanning modules are arranged and supported on the same surface of the supporting base, even if the supporting base is inclined or the like, all the optical scanning modules change their postures integrally. Even if there is an absolute shift in the emission direction, no relative shift occurs, the scan position shift at the division boundary can be reduced, and high-quality image formation can be performed.

Furthermore, the housing is provided with a positioning portion for abutting and positioning the mounting surface on which the optical scanning modules are arranged, so that the reference surface on which the optical scanning module is mounted and the positioning portion are the same, and the housing is connected to the optical scanning module. Accuracy of relative position with respect to the image means can be ensured, scanning position deviation at the division boundary can be reduced, and high-quality image formation can be performed.

An image forming apparatus according to another aspect of the present invention includes:
It is characterized in that one line of image data is divided into the number of unit modules and image recording is performed on an image forming unit that forms a single color image.

Further, an image forming apparatus according to another aspect of the present invention includes:
It is characterized in that it is provided in each of the image forming units for each color for forming a full-color image, and performs image recording individually using image data corresponding to each color.

An image forming apparatus according to another aspect of the present invention includes:
It is characterized in that it is commonly used for the image forming units for each color for forming a full-color image, and that image recording is performed in chronological order using image data corresponding to each color.

Further, an image forming apparatus according to another aspect of the present invention includes:
It is characterized in that the image forming unit for each color forming a full-color image is commonly used for one or a plurality of colors, and that image recording is performed in a time series with image data corresponding to each color.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of an optical scanning module in an optical scanning device according to the present invention.

FIG. 2 is an exploded perspective view showing a configuration of another optical scanning module in the optical scanning device according to the present invention.

FIG. 3 is an exploded perspective view showing a configuration of another optical scanning module in the optical scanning device according to the present invention.

FIG. 4 is a schematic diagram of an optical scanning device according to one embodiment of the present invention.

FIG. 5 is a sectional view of the optical scanning device of the present embodiment.

FIG. 6 is a schematic cross-sectional view showing a configuration of a digital copier equipped with the optical scanning device of the present invention.

FIG. 7 is a schematic sectional view showing a configuration of a laser printer equipped with the optical scanning device of the present invention.

FIG. 8 is a schematic sectional view showing a configuration of a plain paper facsimile equipped with the optical scanning device of the present invention.

[Explanation of symbols]

 301; housing; 302; electrical board.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2C362 AA07 AA10 BA04 BA49 BA85 BA90 2H045 BA02 BA22 BA36 DA02 DA11 5C051 AA02 CA07 DA02 DB02 DB22 DB24 DB30 DC04 DC05 DC07 DE09 EA01 FA01 5C072 AA03 BA02 BA17 HA02 HA06 HA09 HA13 Q XA05

Claims (7)

[Claims] 1. A light-emitting source; a support base for supporting a plurality of optical scanning modules having a deflector for deflecting a light beam from the light-emitting source in a main scanning direction; An optical scanning device, comprising: a housing that supports and positions the plurality of image forming units that form an image of a light beam scanned by the deflector on a surface to be scanned, and supports the support base. 2. The optical scanning device according to claim 1, wherein all the optical scanning modules are arranged and supported on the same surface of the support base. 3. The optical scanning device according to claim 1, wherein the housing has a positioning portion for abutting and positioning a mounting surface on which the optical scanning modules are arranged. 4. An image forming apparatus for performing image recording by dividing image data for one line into unit modules for an image forming unit for forming a single color image. 5. The image forming apparatus according to claim 4, wherein the image forming apparatus is provided in each image forming unit for each color for forming a full-color image, and performs image recording individually using image data corresponding to each color. 6. The image forming apparatus according to claim 4, wherein the image forming unit is commonly used for an image forming unit for each color for forming a full-color image, and performs image recording in chronological order using image data corresponding to each color. 7. An image forming section for each color for forming a full-color image is commonly used for one or a plurality of colors, and image recording is performed in a time series by image data corresponding to each color.
The image forming apparatus as described in the above.