JP2006326901A - Optical housing, optical scanner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optical housing in which an extra optical housing conforming to the rotating speed of a rotary polyhedral mirror as a deflection means is not required when print speed is increased due to model change, and to obtain an optical housing an optical scanner and an image forming apparatus. <P>SOLUTION: A light source emitting a light beam, a rotary polyhedral mirror 111 for deflecting a scanning light beam from the light source, a motor 4 for driving the rotary polyhedral mirror 111, a drive control circuit board 3 of the motor 4, and an optical means for forming the image of the scanning light beam deflected by the rotary polyhedral mirror 111 on an image forming plane are positioned and held in an optical housing 1. Fastening parts of the drive control circuit board 3 are provided at a plurality of positions so that fixing position of the drive control circuit board 3 can be selected arbitrarily. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical housing and an optical scanning device used in an optical writing system such as a digital copying machine and a laser printer, and a monochrome image forming apparatus using monochromatic toner using the optical scanning device, The present invention also relates to an image forming apparatus capable of forming a color image by superimposing a plurality of color toner images.

  In an image forming apparatus using an electrophotographic process called the Carlson process, as the image bearing member rotates, for example, the photosensitive drum, uniform charging on the surface of the photosensitive drum, latent image formation by exposure, development, transfer, and fixing , And the like are sequentially executed to form an image. In the monochrome image forming apparatus, a monochrome image is formed using one photosensitive drum. In a multicolor image forming apparatus, a color image is formed by rotating a single photosensitive drum a number of times (for example, four times), or a plurality of photosensitive drums are arranged along the transport direction of the transfer body, A color image is formed by a multicolor image forming method in which the toner images formed at the image forming stations of the respective colors are overlapped.

  In order to form a latent image on the photosensitive member, a light source unit that emits a light beam, a deflecting unit that deflects the light beam and performs main scanning, an incident optical system that causes the light beam emitted from the light source unit to enter the deflecting unit, There is used an optical scanning device having an imaging optical means comprising one or a plurality of optical elements for imaging the light beam deflected and scanned by the deflection means on the surface of the photosensitive member, and an optical housing for positioning and holding them. In a monochrome image forming apparatus, a latent image is formed on a photoconductor using one of the optical scanning devices described above. A color image forming apparatus includes one or more optical scanning devices. In color image forming apparatuses, a tandem method including a plurality of photoconductors corresponding to each color is widely adopted, and a light beam corresponding to the number of photoconductors is emitted from a single optical scanning device to form a latent image of an image corresponding to each color. Are formed on each photoconductor, an optical scanning device is arranged according to the number of photoconductors, and a latent image of an image corresponding to each color is formed on each photoconductor by a light flux emitted from each optical scanning device, There are optical scanning devices that use half of the number of photoconductors, and two light beams are emitted from one optical scanning device to form a latent image of an image corresponding to each color on each photoconductor.

  In these image forming apparatuses, when the model is made into a series and the image forming speed (printing speed) of the image forming apparatus belonging to the series is changed, the rotating speed of the rotary polygon mirror (polygon scanner) which is a light deflecting unit is changed. May be changed to change the scanning speed, that is, the scanning line speed. Since the image forming apparatuses belonging to the same series share the same optical design of the scanning optical system, when changing the image forming apparatus belonging to the same series to increase the printing speed, for example, The rotating polygon mirror is supported at a high rotational speed. However, when the rotational speed of the rotary polygon mirror is increased, the current flowing through the integrated circuit on the drive control circuit board for controlling the rotation of the deflecting means increases, and the amount of heat generated by the rotational drive unit and the integrated circuit increases. In addition, the amount of heat generated from the rotation drive unit increases, and the temperature inside the optical housing rises. In particular, when the optical housing is made of a material with low thermal conductivity such as resin, heat is difficult to escape, adversely affects the optical components and electronic components inside the optical housing, and the life of the rotary drive unit is reduced. There was a drawback of shortening.

  The rise in temperature inside the optical housing due to heat generation is, for example, a scanning lens that constitutes the imaging optical means when heat accumulates in the optical housing and has a temperature gradient in addition to the adverse effects on parts and the disadvantage of shortening the service life. As a result, the expansion of the beam spot is not uniform, and the beam spot diameter on the photoconductor is abnormal, and the position of the beam spot varies with time, resulting in problems such as abnormal images.

On the other hand, if the rotational speed of the rotating polygon mirror as the deflecting means is increased, the wind noise of the rotating polygon mirror increases. Therefore, a chamber or space for storing the deflecting means is created in the optical housing to isolate it from other spaces. There is a case. In this case, since heat is trapped in the space in which the deflection means is stored, heat generation of the deflection means becomes a problem. The drive circuit control board is separated from the other deflection scanning means, and the drive circuit control board is mounted on the deflection means. Measures such as taking it out of the storage space were taken. In addition to measures such as taking the drive circuit control board out of the storage space of the deflecting means, a material having good thermal conductivity is used for a part of the optical housing, or the optical housing and the deflecting scanning means are installed. A device for storing the room or a cover of the space has been devised (for example, see Patent Document 1). Also, an invention that allows air to flow back and forth between the space for storing the deflection scanning means and the outside (for example, see Patent Document 2), an invention that is devised to increase the thermal conductivity of the lid of the optical housing (for example, Patent Document 3 and Patent Document 4), an invention in which a heat dissipating material is attached to the deflection scanning means (for example, refer to Patent Document 5).
The inventions described in these patent documents address the problem of adverse effects on parts and shortening the service life by dissipating heat, and when the heat is trapped in the optical housing and has a temperature gradient, for example, the imaging optical means The (scanning lens) does not expand uniformly, and an attempt is made to cope with problems such as an abnormal beam spot diameter on the photoconductor and a change in the position of the beam spot over time, resulting in an abnormal image. Is.

  However, in the configuration as described in each of the above patent documents, even in an image forming apparatus belonging to a specific series that uses the same scanning optical system, the rotation speed of the rotating polygon mirror of the deflecting unit is supported. It is necessary to prepare a separate optical housing. If the optical housing is made of resin, precise mold design and molding conditions must be determined, and evaluation will be required for each model, resulting in waste of human resources. It was. In particular, in a color image forming apparatus using an optical scanning device that emits a luminous flux equal to or more than the number of photosensitive members, the optical housing is enlarged, and the specifications of the optical housing differ depending on the model. A plurality of molds for the optical housing are required in one series, and this has been against the resource saving such as waste of resources as mold material, waste of molding resin for molding condition determination and evaluation. Furthermore, when a plurality of optical housing molds are required in one series, there is a problem that the manufacturing cost of the mold, the mold management cost, etc. increase. As an invention devised so that it is not necessary to prepare a plurality of optical housings even when image forming apparatuses are serialized, there is an invention described in Patent Document 6, but it is not an invention that solves the problem of heat generation of the deflection scanning means. .

  Up to this point, we have described the problems when image forming devices are serialized. However, from the viewpoint of resource saving in recent years, models are collected from users and used as new products after making necessary changes and adjustments. The “reuse machine” is being adopted. Even in the case of using a scanning optical system having the same optical design in this “reuse machine”, there is the same problem as the above problem when dealing with an increase in printing speed.

Japanese Patent No. 3075497 JP-A-9-288246 Japanese Patent Laid-Open No. 2000-180776 JP 2000-258719 A JP 2003-215490 A Japanese Patent No. 3434153

  The present invention provides a deflecting means for a case where a scanning optical system having the same optical design, such as a series of image forming apparatuses or “reuse machines”, is used and the printing speed is increased due to a change in model specifications. It is an object of the present invention to provide an optical housing, an optical scanning device using the optical housing, and an image forming apparatus which are devised so that it is not necessary to separately prepare an optical housing corresponding to the rotational speed of the rotating polygon mirror.

According to the first aspect of the present invention, a light source that emits a light beam, a rotary polygon mirror that deflects and scans the light beam from the light source, a motor that rotationally drives the rotary polygon mirror, a drive control circuit board for the motor, and the rotation An optical housing for positioning and holding the light beam deflected and scanned by a polygon mirror on an image forming surface and capable of arbitrarily selecting a fixed position of the drive control circuit board Thus, the fastening location of the drive control circuit board is provided at a plurality of locations.
As in the second aspect of the invention, the material of the optical housing may be glass fiber-containing resin.
According to a third aspect of the present invention, the optical housing may be formed by combining a plurality of partial housings and combining the plurality of partial housings.

  According to a fourth aspect of the present invention, there is provided a light source that emits a light beam, a rotary polygon mirror that deflects and scans the light beam from the light source, a motor that rotationally drives the rotary polygon mirror, a drive control circuit board for the motor, and the rotation An imaging optical means for imaging the light beam deflected and scanned by the polygon mirror on the imaging plane; and an optical housing for positioning and holding the light source, the rotary polygon mirror, the motor, the drive control circuit board, and the imaging optical means; The optical housing has a plurality of fastening points where the drive control circuit board can be fastened so that the fixing position of the drive control circuit board can be arbitrarily selected. The drive control circuit board is fixedly fastened to an arbitrary fastening portion of the optical housing.

According to a fifth aspect of the present invention, in the optical scanning device according to the fourth aspect, the deflection scanning unit is configured integrally with the rotary polygon mirror, the motor, and the drive control circuit board, and includes a plurality of units provided in the optical housing. It is characterized by being fastened to one of the fastening points via a drive control circuit board.
According to a sixth aspect of the present invention, in the optical scanning device according to the fifth aspect, the deflection scanning means includes a light beam emitted from a light source and a plane A passing through the center of the effective width in the main scanning direction of the imaging optical means and perpendicular to the main scanning direction. The plane A ′ that is intersected with the center line B of the rotary polygon mirror is located in a region surrounded by the circumscribed circle and the inscribed circle of the rotary polygon mirror and is parallel to the plane A through the rotation center of the rotary polygon mirror. It is fastened to the optical housing so as to be positioned on the light source side.

According to a seventh aspect of the present invention, in the optical scanning device according to the fourth aspect, the deflection scanning means is configured separately from a rotary polygon mirror and a motor part that rotationally drives the mirror, and a drive control circuit board. The rotary polygon mirror and the motor part are fastened at one of a plurality of fastening points provided in the optical housing, and the drive control circuit board is different from the position where the rotary polygon mirror and the motor part are fastened. It is characterized in that it is fastened at the position where it is fastened.
According to an eighth aspect of the present invention, in the optical scanning device of the seventh aspect, the rotary polygon mirror and the motor portion of the deflection scanning means pass through the center of the effective width in the main scanning direction of the imaging optical means and are perpendicular to the main scanning direction. The plane A and the intersection of the center line B of the light beam emitted from the light source exist in the area surrounded by the circumscribed circle and the inscribed circle of the rotary polygon mirror and pass through the rotation center of the rotary polygon mirror to the plane A. The optical housing is fastened so as to be positioned on the light source side with a parallel plane A ′ as a boundary.

According to a ninth aspect of the present invention, in the optical scanning device according to the seventh aspect, the rotary polygon mirror and the motor portion of the deflection scanning means are integrated with a dummy substrate having the same dimensions as the drive control circuit board of the rotary polygon mirror. It is characterized by.
According to a tenth aspect of the present invention, in the optical scanning device according to the fifth or seventh aspect, the deflection scanning means is fastened by screws.
The invention according to claim 11 is the optical scanning device according to claim 4, wherein the material of the optical housing is a resin containing glass fiber.
According to a twelfth aspect of the present invention, in the optical scanning device according to the fourth aspect of the present invention, the optical housing includes a plurality of partial housings, and the optical housing is configured by combining the plurality of partial housings. To do.

According to a thirteenth aspect of the present invention, in the optical scanning device according to the twelfth aspect of the present invention, the deflection scanning means formed integrally with the rotary polygon mirror, the motor and the drive control circuit board is fastened to one of the partial housings. It is characterized by being.
According to a fourteenth aspect of the present invention, in the optical scanning device according to the twelfth aspect, the deflection scanning means is configured separately from a rotary polygon mirror, a motor portion for rotationally driving the mirror, and a drive control circuit board. The polygon mirror and the motor part are fastened to one of the partial housings.

According to a fifteenth aspect of the present invention, in the optical scanning device according to the twelfth aspect, the deflection scanning means is configured separately from a rotary polygon mirror, a motor portion for rotationally driving the mirror, and a drive control circuit board. The control circuit board is fastened to a partial housing to which a rotary polygon mirror and a motor are fastened.
According to a sixteenth aspect of the present invention, in the optical scanning device according to the twelfth aspect, the deflection scanning means is configured separately from a rotary polygon mirror, a motor portion for rotationally driving the mirror, and a drive control circuit board. The control circuit board is fastened to a partial housing different from the partial housing to which the rotary polygon mirror and the motor are fastened.

  According to a seventeenth aspect of the present invention, there is provided an image forming apparatus having an apparatus for executing an electrophotographic process, and the optical scanning according to any one of the third to sixteenth aspects as an apparatus for executing an exposure process in the electrophotographic process. A device is provided.

  According to the present invention, in an optical housing, an optical scanning device, and an image forming apparatus, the optical housing is provided with at least two fastening portions for deflecting scanning means, thereby forming a series of image forming apparatuses, “reuse machines”, and the like. When using a scanning optical system with the same optical design and the model specifications change and the printing speed increases, there is no need to prepare a separate optical housing corresponding to the rotational speed of the rotary polygon mirror as the deflecting means. Therefore, it is possible to provide an optical housing, an optical scanning device, and an image forming apparatus using the optical housing, which are inexpensive and can save resources.

  Hereinafter, embodiments of an optical housing, an optical scanning device, and an image forming apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of a basic optical system layout of an image forming apparatus to which the present invention is applied. In FIG. 1, reference numeral 101 denotes a semiconductor laser as light source means, 105 denotes a coupling lens, 109 denotes a cylindrical lens, 111 denotes a rotary polygon mirror as deflection means, 113 denotes a first scanning lens as first imaging means, Reference numeral 121 denotes a second scanning lens as second imaging means, 123 denotes dust-proof glass, 204 denotes a surface of the photosensitive member as a scanned surface, and G denotes soundproof glass. In FIG. 1, the vertical direction of the paper surface is the main scanning direction, and the direction perpendicular to the paper surface is the sub-scanning direction.

  The light beam emitted from the semiconductor laser 101 is coupled by the coupling lens 105, passes through an aperture (not shown) for shaping the light beam, and enters a cylindrical lens 109 having power only in the sub-scanning direction. In this specification, the combination of the coupling lens 105 and the cylindrical lens 109 is referred to as an incident optical system. The light beam emitted from the cylindrical lens 109 is formed as a long line image in the main scanning direction in the vicinity of the deflection reflection surface of the rotary polygon mirror 111, and the light beam is deflected and scanned in the main scanning direction by rotating the rotary polygon mirror 111. The deflected and scanned light beam is condensed on the surface of the photosensitive member 204 via the first scanning lens 113 and the second scanning lens 121, and scans the surface of the photosensitive member 204 at a substantially constant speed.

  With the configuration shown in FIG. 1, an image of one color (monochrome) can be formed. As a color image forming apparatus, it is common to use four colors of magenta (represented as M), cyan (represented as C), yellow (represented as Y), and black (represented as Bk). Therefore, the optical system shown in FIG. 1 is arranged corresponding to one image forming station, and four optical systems and photoconductors are arranged corresponding to each color to constitute four stations.

  The light beam deflection scanning means can be divided into a main component part: a rotary polygon mirror part, a motor part that rotationally drives the rotary polygon mirror, and a drive control circuit board part that controls the rotation of the motor. 2 and 3 are sectional views showing an example in which a rotary polygon mirror, a motor, and a drive control circuit board constituting the deflection scanning means are integrally configured. In other words, the deflection scanning unit includes the rotary polygon mirror 111, the motor 4 that rotates the rotary polygon mirror 111, and the drive control circuit board 3. In the motor 4, a rotating shaft 6 that forms the rotation center of the rotor is rotatably supported by a motor bearing portion 5, and the bearing housing portion 2 that houses the motor bearing portion 5 is integrally fastened to the drive control circuit board 3 by caulking or the like. Has been. The rotary polygon mirror 111 is fixed to the upper end portion of the rotary shaft 6 by a fixed spring 7, and the rotary polygon mirror 111 is configured to rotate integrally with the rotary shaft 6. When the rotary polygon mirror 111 rotates, the light beam emitted from the semiconductor laser 101 is deflected and scanned by the deflecting reflection surface, and the light beam is incident on the surface of the photosensitive member 204 through the lens groups 113 and 121 constituting the imaging optical means. While condensing, the surface of the photoconductor 204 is scanned at a constant speed. This scanning direction is called a main scanning direction. An integrated circuit 12 is installed on the drive control circuit board 3.

  Such a deflection scanning means is positioned and fixed to the optical housing 1 by screws 8. The optical housing 1 is made of metal such as resin containing glass fiber or aluminum die cast. The optical housing 1 is covered with a cover member 13 made of a thin metal plate, a synthetic resin plate, or the like, and between the optical housing 1 as the optical box main body and the cover member 13 for sealing the inside of the optical box main body. A gasket (not shown) may be sandwiched.

  The optical housing 1 shown in FIG. 2 and FIG. 3 includes the drive control circuit board of the deflection scanning unit in which the rotary polygon mirror 111, the motor 4 for rotating the rotary polygon mirror 111, and the drive control circuit board 3 are integrated. In addition to the fastening part for fixing 3 with the screw 8, in order to fasten and fix the drive control circuit board 3 when the drive control circuit board 3 is separated from the rotary polygon mirror 111 and the motor 4, A fixed portion 20 is provided in advance. Another fixing portion 20 for fastening and fixing the drive control circuit board 3 is provided on the back surface of the optical housing 1 as shown in FIG. 2, and is indicated by a broken line in FIG. However, the fastening position of the drive control circuit board 3 is not particularly limited as long as it is a part where the drive control circuit board 3 blocks the light beam or does not interfere with other components.

  The embodiment shown in FIGS. 2 and 3 is an example in which the deflection scanning unit is integrally configured by the rotary polygon mirror 111, the motor 4, and the drive control circuit board 3, and is provided in the optical housing 1 at a plurality of locations. The deflection scanning means is fastened via the drive control circuit board 3 by selecting one of the fastening places of the drive control circuit board 3 and fastening the drive control circuit board 3. Although the optical housing 1 is provided with another fixing portion 20 to which the drive control circuit board 3 can be fastened in advance, the drive control circuit board is not fastened to the other fixing portion 20. Accordingly, the other fixed portion 20 is unused and is a dummy in this example.

  In the first embodiment, the position where the deflection scanning unit is selectively fastened to the optical housing 1 satisfies the following condition. As shown in FIG. 4, the intersection of the plane A passing through the center of the effective width in the main scanning direction of the imaging optical means 113 and 121 and perpendicular to the main scanning direction and the center line B of the light beam emitted from the light source is rotated. The intersection of the plane A and the center line B is such that the intersection of the plane A and the center line B exists in a region (shaded region in FIG. 4) surrounded by the circumscribed circle 52 and the inscribed circle 51 of the polygonal mirror 111. The deflection scanning means is positioned so as to deviate toward the light source side with a plane A ′ parallel to the plane A passing through the center of rotation.

  In the second embodiment, the current flowing in the integrated circuit on the drive circuit control board is increased by increasing the printing speed and the rotation speed of the rotary polygon mirror constituting the deflection scanning unit while using the optical system of the same specification. This is an embodiment that can cope with a case where the heat generation amount of the rotation drive unit and the integrated circuit increases. In a series of image forming apparatuses, reuse machines, etc., when the rotary polygon mirror constituting the deflection scanning means, the motor, and the drive control circuit board are integrally configured, when the high-speed specification is changed, As described above, the temperature inside the optical housing rises to adversely affect the optical components and electronic components inside the optical housing, thereby causing a problem of shortening the life of the rotary drive unit. In order to avoid this problem, the second embodiment is an example in which the rotary polygon mirror and the motor constituting the deflection scanning means are separated from the drive control circuit board. A sectional view thereof is shown in FIG.

  In FIG. 5, in order to fasten and fix the drive control circuit board, the drive control circuit board 3 is fastened with screws 8 to another fixing portion 20 formed in advance on the outside of the optical housing 1. Further, the rotary polygon mirror 111 and the motor 4 constituting the deflection scanning means are integrated with a dummy substrate 21 having the same dimensions as the drive control circuit board 3 of the rotary polygon mirror 111, and the dummy substrate 21 is screw 8. The parts of the rotary polygon mirror 111 and the motor 4 are fixed to the optical housing 1 by being fastened and fixed to the optical housing 1. The separate motor 4 part and the drive control circuit board 3 are electrically coupled by a cable (not shown), the rotation of the motor 4 is controlled by the drive control circuit board 3, and the light beam is deflected by the rotation of the rotary polygon mirror 111. A scan is performed.

  In the embodiment shown in FIG. 5, the drive control circuit board 3 is arranged outside the optical housing 1, but may be inside the optical housing 1. In the example shown in FIG. 5, the integrated circuit 12 is in a positional relationship such that the integrated circuit 12 is sandwiched between the drive control circuit board 3 and the optical housing 1. 1 may be disposed on the lower surface of the drive control circuit board 3 in a direction away from 1, that is, in FIG. In any case, in the second embodiment, the driving circuit board 3 on which the integrated circuit 12 serving as the heating means is mounted is separated from the rotary polygonal mirror 111 and the motor 4 serving as the deflection scanning means, and the driving circuit board 3 is mounted on the optical housing 1 in advance. It is characterized in that it is fixed independently from the positioning portion provided.

  In the second embodiment, the position where the deflection scanning means is selectively fastened to the optical housing 1 passes through the center of the effective width in the main scanning direction of the imaging optical means 113 and 121 as shown in FIG. In the region (shaded region in FIG. 4) where the intersection of the plane A perpendicular to the direction and the center line B of the light beam emitted from the light source is surrounded by the circumscribed circle 52 and the inscribed circle 51 of the rotary polygon mirror 111 In addition, it is set so as to exist on the light source side with a plane A ′ passing through the rotation center of the rotary polygon mirror 111 and parallel to the plane A as a boundary.

  As described above, if another fixing portion 20 for fastening and fixing the drive control circuit board 3 to the optical housing 1 is provided in advance, in an image forming apparatus or a reuse machine having the same optical system configuration and a series. The deflection scanning means is configured to be used separately for one in which the rotary polygon mirror 111, the motor 4 and the drive control circuit board 3 are integrally formed, and one in which the drive control circuit board 3 is separated from the rotary polygon mirror 111 and the motor 4. Can do. This is particularly effective when the printing speed is increased and the rotation speed of the deflection scanning means is changed to the high speed specification, as in the first embodiment. That is, when changing to the high-speed specification, the current flowing through the integrated circuit on the drive circuit control board increases, the amount of heat generated in the rotary drive unit and integrated circuit increases, the temperature inside the optical housing rises, and the inside of the optical housing increases. Adversely affects the optical parts and electronic parts, and shortens the life of the rotary drive unit. However, the above-mentioned problem can be solved by changing as in the second embodiment, and the rotational surface of the deflecting means can be rotated. It is possible to provide an image forming apparatus that does not require a separate optical housing corresponding to the rotational speed of the mirror.

  As described above, it is not necessary to separately prepare the optical housing 1 corresponding to the rotational speed of the rotary polygon mirror 111 of the deflecting means. In the case where the optical housing 1 is a resin containing glass fiber, precise mold design and molding are performed. Conditioning and evaluation are unnecessary for each model, and there is also an advantage that human resources are not wasted. In particular, in a color image forming apparatus that uses an optical scanning device that emits as many light beams as the number of photoconductors from one optical scanning device, the optical housing is enlarged, and a separate optical housing is prepared. In this case, only one type of mold for the optical housing can be used in the series machine, which eliminates waste of mold material resources, molding conditions, and waste of glass-filled resin for evaluation. Can be achieved. Furthermore, an increase in mold management costs and the like can be suppressed. The same applies to the “reuse machine”.

As described in the first and second embodiments, the series machine and the reuse machine can be used with one type of optical housing for the heat generated by the deflecting means. It is possible to do. However, an optical housing made of glass fiber-containing resin tends to accumulate heat. Conventionally, as the material of the optical housing, a resin containing glass fiber is used when the rotation speed of the deflecting means is low, and a metal material with good heat dissipation, such as aluminum die casting, is used when the rotation speed is high.
However, according to the present invention, an optical housing made of glass fiber can be used in a wide range from low speed to high speed by using optical housings of the same specifications as in the first or second embodiment. It becomes. Accordingly, an optical housing made of glass fiber-containing resin can be used from a low speed machine to a high speed machine, so that a cheaper optical housing, optical scanning device and image forming apparatus can be provided.

  In the first and second embodiments, the case where one optical scanning device is used for one photosensitive member has been described. In recent years, due to the demand for speeding up of color image forming apparatuses, a color image is formed by a multicolor image forming method in which a plurality of photosensitive drums are arranged along the transfer direction of a transfer body and toner images formed at image forming stations of respective colors are superimposed There are an increasing number of so-called tandem image forming apparatuses. FIG. 6 shows an example of an optical system around the deflecting unit applied to the tandem image forming apparatus. In FIG. 6, the deflecting means is represented by rotating polygonal mirrors 111 and 112 integrally formed one above the other. An optical system is arranged symmetrically on the left and right with the deflection means interposed therebetween. Hereinafter, a description will be given by taking the optical system on one side as a representative. Two light beams that have been emitted from the two light sources 101 and 102, transmitted through the coupling lenses 105 and 106, and further transmitted through the cylindrical lens 109 are incident on the rotary polygon mirror 111, and are long in the main scanning direction near the deflecting reflection surface. Line images are formed. Two light beams that have been emitted from the two light sources 103 and 104, transmitted through the coupling lenses 107 and 108, and further transmitted through the cylindrical lens 110 are incident on the rotary polygon mirror 112, and are long in the main scanning direction near the deflecting reflection surface. Line images are formed. The light beams deflected and reflected by the rotation of the rotary polygon mirrors 111 and 112 are transmitted through the first scanning lenses 113 and 114 that are arranged one above the other, and further transmitted through the second scanning lens (not shown), and the optical path is transmitted by an appropriate mirror. Are bent and guided to each photoconductor, imaged on the surface of each photoconductor, and scanned. Similarly, an image is formed on the surface of each photoconductor and scanned by an optical system disposed on the other side of the rotary polygon mirrors 111 and 112.

  In the case of the third embodiment, the optical scanning device described in the first and second embodiments can be used. In the case of the third embodiment, since the optical system is symmetrically arranged on the left and right with the deflection scanning unit interposed therebetween, the optical housing becomes larger than the case where one optical scanning device is used for one photosensitive member. . Therefore, the above-described effects of the present invention that can use the optical housing in common for the series machine and the reuse machine are increased. Note that the glass indicated by G in FIG. 6 is used to create a “chamber” that houses the deflection scanning means inside the optical housing when the wind noise of the rotary polygon mirrors 111 and 112 increases. , 112 is used to block a window hole provided to allow the luminous flux to enter and exit.

  FIG. 7 shows a first partial housing and a first partial housing when the optical housing is composed of a plurality of partial housings among the optical scanning devices used in the color image forming apparatus shown in the third embodiment. The example of the main optical element used is shown. In FIG. 7, reference numerals 507 to 510 denote light source means, 111 and 112 denote rotary polygon mirrors constituting deflection scanning means, 113 denotes first imaging optical means, and 525 denotes a first partial housing. Although an example in which the rotary polygon mirror is configured in two stages is shown, a single-stage rotary polygon mirror can be used to devise an optical system. The first partial housing 525 is provided with an appropriate number of protrusions 526 and screw fixing holes 524 so as to be fixedly fastened to a second optical housing described later. In addition, an opening 505 is provided so that the light beam deflected and scanned by the rotary polygon mirrors 111 and 112 and transmitted through the first imaging unit 113 reaches the second imaging unit (not shown). Four holes 607 are formed on the side wall of the first partial housing 525 opposite to the side wall on which the projection 526 is provided, and light source means 507 to 510 are fitted into these holes 607, respectively. Fastened to the housing 525. The side walls to which the light source means 507 to 510 are attached are formed so as to be inclined so that the light beams emitted from the light source means 507 to 510 are directed to the rotary polygon mirrors 111 and 112. A lid 504 is attached to the first partial housing 525 and constitutes a first optical scanning device.

  In the first partial housing 525, as in the embodiment shown in FIG. 2, even when “the deflection scanning means is integrally formed of a rotary polygon mirror, a motor, and a drive control circuit board” A plurality of fastening points of the drive control circuit board are provided in advance so as to be able to cope with “when the scanning unit is configured separately from the rotary polygon mirror, the motor, and the drive control circuit board”. However, since the figure becomes complicated, the above fastening part is not shown in FIG. By configuring in this way, as described in the first and second embodiments, the printing speed is changed in the series machine and the reuse machine, and the problem of heat generation due to the change in the rotation speed of the rotary polygon mirror of the deflection scanning unit is One type of housing can be used.

  FIG. 8 shows the optical scanning device used in the color image forming apparatus described in the third embodiment, which is fixed to the second partial housing and the second partial housing when the optical housing is composed of a plurality of partial housings. An example of main optical elements to be fastened is shown. In FIG. 8, reference numeral 123 denotes a second imaging optical means, 632 denotes a fixing member of the second imaging optical means 123, and 630 denotes a mirror. Four second image-forming optical means 123, fixing members 632, and mirrors 630 are provided corresponding to each color. The mirror 630 bends the deflected light beam and guides it to the surface of each photoconductor. Both end portions of these members are fitted in fitting fixing holes 633 and 634 formed on the vertical surfaces of the members 620 and 621 constituting the side wall of the second partial housing, and are pressed by a leaf spring (not shown). Positioning is fixed.

  The second partial housing includes side wall constituent members 620 and 621 and a bottom plate 623, and the bottom plate 622 is provided with an opening 622 for transmitting a light beam toward a photosensitive member (not shown). The example shown in FIG. 8 is configured assuming that the photosensitive member is positioned below the second optical housing. However, when the photosensitive member is above the second optical housing, the upper plate And an opening for transmitting the luminous flux may be provided there.

  The second optical housing can be accommodated even when "the deflection scanning means is configured separately from the rotary polygon mirror, the motor, and the drive control circuit board". However, a fastening portion of the drive control circuit board is provided in advance. When the drive control circuit board is fixed at this location, the deflection scanning means part composed of a rotary polygon mirror and a motor positioned and fixed to the first optical housing and the motor are connected by a harness to drive the deflection scanning means. To do. This configuration is the same as in the first and second embodiments.

  FIG. 9 is a perspective view showing an example for fastening the first optical housing 525 and the second optical housing 600. In FIG. 9, the first optical housing 525 is inserted into the second optical housing 600 so as to pass through the opening 527 provided in the side wall of the second optical housing 600. The protrusion 526 of the first optical housing 525 is fitted in the positioning hole 530 of the second optical housing, and the screw fixing hole 524 of the first optical housing 525 and the positioning hole 550 of the second optical housing 600 are screwed. Is inserted and the nut is screwed and tightened, whereby the first optical housing 525 is integrated with the second optical housing 600.

Regarding the optical scanning device used in the color image forming apparatus of this embodiment, more specifically, in the case where the optical housing is divided into a plurality of partial optical housings, the configuration of the deflection scanning means is summarized as follows. .
(1) When the deflection scanning means is integrally formed of a rotary polygon mirror, a motor, and a drive control circuit board: In this case, the deflection scanning means is in the first partial housing, and the first and second The fixed position of the drive control circuit board provided in each partial housing is a dummy.
(2) When the deflection scanning means is configured separately from the rotary polygon mirror, the motor and the drive control circuit board: In this case, the rotary polygon mirror and the motor section of the deflection scanning means are in the first partial housing. The drive control circuit board is fixed somewhere in a fixed position of the drive control circuit board provided in each of the first and second partial housings.

  Of the deflection scanning means (1) and the deflection scanning means (2), the rotary polygon mirror and the motor are selectively fastened to the first partial housing as shown in FIG. The intersection of the plane A that passes through the center of the effective width in the main scanning direction of the imaging optical means 113 and 121 and is perpendicular to the main scanning direction and the center line B of the light beam emitted from the light source is the circumscribed circle 52 of the rotary polygon mirror. It is set in the area surrounded by the inscribed circle 51 (shaded area in FIG. 4), and passes through the rotation center of the rotary polygon mirror and is parallel to the plane A and is on the light source side. ing.

  Further, the material of the first partial housing is assumed to be a resin containing glass fiber, and the material of the second partial housing is assumed to be a sheet metal. However, the present invention is not limited to this. For example, the reverse may be used. The material of the housing may be the same material. As described above, also in the case of an optical scanning device used in a color image forming apparatus (one in which an optical housing is divided into a plurality of optical housings), a plurality of fastening positions of the drive control circuit board are provided in advance in the partial housing. The effect is the same as that described in the first and second embodiments.

  FIG. 10 shows an example of a tandem type image forming apparatus using the optical housing and the optical scanning device described so far. In FIG. 10, reference numeral 50 denotes an optical scanning device that has been described so far “a plurality of fastening points of the drive control circuit board are provided in the optical housing”. The optical scanning device 50 can be attached to and detached from the image forming apparatus, and when reused, the optical scanning device can be removed from the image forming apparatus and used as a new model by performing necessary changes and adjustments. It becomes possible.

  In FIG. 10, the optical scanning device 50 is inclined and arranged in the image forming apparatus main body 700, and four photosensitive drums 710, 720, 730, and 740 are parallel to the optical scanning device 50 obliquely below the optical scanning device 50. It is arranged to make. The photosensitive drums 710, 720, 730, and 740 form yellow (Y), cyan (S), magenta (M), and black (Bk) images, respectively, and are emitted from the optical scanning device 50 and have respective colors. By scanning with a light beam modulated with an image signal corresponding to the above, an electrostatic latent image corresponding to each color is formed on the surface of each photosensitive drum. Around each photosensitive drum, a charging device, an exposure device, a developing device, a transfer device, and a cleaning device for performing an electrophotographic process are arranged, and fixing for fixing a toner image formed on the transfer paper The device is arranged. The optical scanning device 50 functions as the exposure device by optically scanning the surface of each uniformly charged photoreceptor drum, and forms a latent image corresponding to each color on the surface of each photoreceptor drum. These latent images are developed with a corresponding color toner by a developing device. A cassette 750 for storing transfer paper in an overlapping manner can be loaded at the bottom of the image forming apparatus main body 700, and the transfer paper drawn one by one from the cassette 750 is a toner image formed on the surface of each photosensitive drum. , The toner images of the respective colors are transferred onto the transfer paper by the transfer device, and a color image is formed. The color image on the transfer paper is fixed by a fixing device 760 and is discharged onto a paper discharge tray by a paper discharge roller.

  When the optical scanning device according to the above-described embodiment is used as the optical scanning device of the color image forming apparatus shown in FIG. 10, the scanning optical system having the same optical design is used, and the printing speed is increased due to the specification change. Therefore, it is not necessary to prepare a separate optical housing corresponding to the rotational speed of the rotary polygon mirror as the deflecting means, and it is possible to provide an image forming apparatus that can be resource-saving at low cost.

  In each of the embodiments described above, the scanning optical system is constituted by two imaging means. However, the number of imaging means constituting the scanning optical system is not limited, and one imaging means or It may be composed of three or more imaging means.

It is an optical arrangement | positioning figure which shows schematically the example of the optical scanning device concerning this invention from the main scanning plane direction. It is front sectional drawing which shows one Example of the optical scanning device concerning this invention. It is a top view of the said Example. It is an optical arrangement | positioning top view for demonstrating the optical arrangement conditions of the said Example. It is front sectional drawing which shows another Example of the optical scanning device concerning this invention. It is a perspective view which shows another Example of the optical scanning device concerning this invention. It is a disassembled perspective view which shows the Example of the optical housing concerning this invention, and an optical scanning optical system. It is a disassembled perspective view which shows the example of the partial housing applicable to this invention. It is a disassembled perspective view which shows the example which combined the said partial housing and the other housing. 1 is a front view conceptually showing an embodiment of an image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical housing 3 Drive control circuit board 4 Motor 12 Integrated circuit 20 Another fixed location 21 Dummy board 101 Semiconductor laser as light source means 111 Rotating polygon mirror 113 1st imaging means 121 2nd imaging means

Claims (17)

A light source that emits a light beam, a rotary polygon mirror that deflects and scans the light beam from the light source, a motor that rotationally drives the rotary polygon mirror, a drive control circuit board for the motor, and the scanning that is deflected and scanned by the rotary polygon mirror An optical housing for positioning and holding an imaging optical means for imaging a light beam on an imaging surface,
An optical housing, wherein a plurality of fastening locations of the drive control circuit board are provided so that a fixed position of the drive control circuit board can be arbitrarily selected.   2. The optical housing according to claim 1, wherein the material of the optical housing is a resin containing glass fiber.   3. The optical housing according to claim 1, wherein the optical housing includes a plurality of partial housings, and the plurality of partial housings are coupled to form an optical housing. A light source that emits a light beam, a rotary polygon mirror that deflects and scans the light beam from the light source, a motor that rotationally drives the rotary polygon mirror, a drive control circuit board for the motor, and the scanning that is deflected and scanned by the rotary polygon mirror Optical scanning comprising: an imaging optical means for imaging a light beam on an imaging surface; and an optical housing for positioning and holding the light source, rotary polygon mirror, motor, drive control circuit board, and imaging optical means In the device
The optical housing has a plurality of fastening points to which the drive control circuit board can be fastened so that the fixing position of the drive control circuit board can be arbitrarily selected.
An optical scanning device, wherein the drive control circuit board is fixedly fastened to an arbitrary fastening portion of the optical housing.   5. The optical scanning device according to claim 4, wherein the deflection scanning unit is configured integrally with the rotary polygon mirror, the motor, and the drive control circuit board, and is provided at one of a plurality of fastening points provided in the optical housing. An optical scanning device, which is fastened via a drive control circuit board.   6. The optical scanning device according to claim 5, wherein the deflection scanning means is an intersection of a plane A passing through the center of the effective width in the main scanning direction of the imaging optical means and perpendicular to the main scanning direction and the center line B of the light beam emitted from the light source. Is located in the region surrounded by the circumscribed circle and the inscribed circle of the rotating polygon mirror, and is positioned on the light source side with a plane A ′ passing through the rotation center of the rotating polygon mirror and parallel to the plane A as a boundary. An optical scanning device which is fastened to an optical housing.   5. The optical scanning device according to claim 4, wherein the deflection scanning means is configured separately from a rotary polygon mirror and a motor portion for rotationally driving the rotary polygon mirror and a drive control circuit board, and the rotary polygon mirror and the motor portion. Is fastened to one of a plurality of fastening points provided in the optical housing, and the drive control circuit board is fastened to a fastening part at a position different from the position where the rotary polygon mirror and the motor part are fastened. An optical scanning device characterized by comprising:   8. The optical scanning device according to claim 7, wherein the rotary polygon mirror and the motor portion of the deflection scanning means are emitted from the light source and the plane A that passes through the center of the effective width in the main scanning direction of the imaging optical means and is perpendicular to the main scanning direction. The intersection of the center lines B of the luminous fluxes is present in a region surrounded by the circumscribed circle and the inscribed circle of the rotating polygon mirror, and passes through the rotation center of the rotating polygon mirror and is parallel to the plane A ′ parallel to the plane A ′. An optical scanning device, which is fastened to an optical housing so as to be positioned on the light source side.   8. The optical scanning device according to claim 7, wherein the rotary polygon mirror and the motor portion of the deflection scanning means are integrated with a dummy substrate having the same dimensions as the drive control circuit board of the rotary polygon mirror. Scanning device.   8. The optical scanning device according to claim 5, wherein the deflection scanning means is fastened with screws.   5. The optical scanning device according to claim 4, wherein the material of the optical housing is a resin containing glass fiber.   5. The optical scanning device according to claim 4, wherein the optical housing includes a plurality of partial housings, and the optical housing is configured by coupling the plurality of partial housings.   13. The optical scanning device according to claim 12, wherein a deflection scanning means in which the rotary polygon mirror, the motor, and the drive control circuit board are integrally formed is fastened to one of the partial housings. apparatus.   13. The optical scanning device according to claim 12, wherein the deflection scanning means is configured separately as a rotary polygon mirror and a motor portion for rotationally driving the rotary polygon mirror and a drive control circuit board, and the rotary polygon mirror and the motor portion are partially provided. An optical scanning device which is fastened to one of housings.   13. The optical scanning device according to claim 12, wherein the deflection scanning means is separately configured as a rotary polygon mirror, a motor portion for rotationally driving the mirror, and a drive control circuit board, wherein the drive control circuit board is a rotary polygon mirror. And an optical scanning device which is fastened to a partial housing to which a motor portion is fastened.   13. The optical scanning device according to claim 12, wherein the deflection scanning means is separately configured as a rotary polygon mirror, a motor portion for rotationally driving the mirror, and a drive control circuit board, wherein the drive control circuit board is a rotary polygon mirror. And an optical scanning device characterized by being fastened to a partial housing different from the partial housing to which the motor portion is fastened. 17. An image forming apparatus comprising an apparatus for executing an electrophotographic process, wherein the optical scanning apparatus according to claim 3 is provided as an apparatus for executing an exposure process in the electrophotographic process. An image forming apparatus.

Images