JP2011158565A - Optical scanner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress transmission failure of a light beam due to thermal deformation of a housing in an optical scanner. <P>SOLUTION: The optical scanner includes: a plurality of heat radiation fluid passages 30b1, 30b2, 30c1 which are provided to the upper part and the lower part of the housing 30 to conduct heat of the inside of the housing 30 to a fluid, wherein the heat radiation fluid passages 30b1, 30b2, 30c1 are arranged without being superimposed when viewed from a vertical direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical scanning device and an image forming apparatus.

  2. Description of the Related Art Conventionally, an optical scanning device, which is a main component of an image forming unit incorporated in an image forming apparatus such as a copying machine or a multifunction peripheral, has a housing having a predetermined volume space inside. In this housing, a polygon comprising a light beam generator (light beam emitting means) for generating a light beam (laser light) and a hexagon for deflecting the light beam emitted from the light beam generator. A mirror, a polygon motor (polygon scanner motor) that rotationally drives the polygon mirror, a control board that supports the polygon motor and mounts electronic components such as an IC, and a light beam deflected by the polygon mirror is used as a photosensitive member An optical element such as an imaging lens (fθ lens) for image formation is provided.

  By the way, the polygon motor attached to the control board generates heat when driven. As the polygon motor generates heat in this manner, the inside of the housing is heated, and various components arranged inside the housing are affected by the heat. For this reason, conventionally, in the optical scanning device, measures against heat as shown in the following Patent Documents 1 to 3 have been taken.

  Patent Documents 1 and 2 disclose a method of cooling air by forcibly applying air to the casing of the polygon motor, and Patent Document 3 provides cooling by adding a heat pipe to the drive circuit board on which the polygon motor is mounted. A method is disclosed.

JP 2002-214552 A JP 2004-12859 A Japanese Patent Laying-Open No. 2005-215284

However, in the configuration of Patent Document 1, since it is necessary to install fans above and below the polygon mirror, it is difficult to reduce the thickness of the optical scanning device.
In the configuration of Patent Document 2, it is difficult to secure a flow path unless the base on which the optical element is installed has a sufficient thickness, and it is difficult to reduce the thickness of the optical scanning device.
Moreover, in the structure of patent document 3, when the optical scanning device is reduced in size, it becomes difficult to ensure the heat transfer amount in a heat pipe.
As described above, when the configuration employed in the conventional optical scanning device is used, it is difficult to reduce the thickness of the optical scanning device.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to make it possible to reduce the thickness of an optical scanning device while reliably dissipating heat inside the housing.

  The present invention adopts the following configuration as means for solving the above-described problems.

  The first invention includes a light beam emitting means for emitting a light beam, a light guiding means for guiding the light beam, a deflecting means for deflecting the light beam, the light beam emitting means, the light guiding means, and An optical scanning device including a box-shaped housing for holding the deflecting unit, the optical scanning device including a plurality of heat-dissipating channels provided at an upper portion and a lower portion of the housing and transferring heat inside the housing to a fluid, A configuration is adopted in which the heat radiation channels are arranged without overlapping when viewed from above and below.

  According to a second aspect of the present invention, in the first aspect of the present invention, the heat dissipation channel is formed by extending linearly at the upper portion of the housing and the fluid flows in one direction, A fluid is formed in the lower part of the housing so as to extend in a straight line in parallel with the first heat radiating flow path, and a fluid having a flow direction opposite to the flow direction of the fluid flowing through the first heat radiating flow path. The structure of having two heat radiation channels is adopted.

  According to a third invention, in the second invention, a polygon mirror and a polygon motor arranged in the center of the housing are provided as the deflecting means, and the second heat radiation channel is arranged immediately below the polygon mirror and the polygon motor. Adopted the configuration that is.

  In a fourth aspect based on the third aspect, the first heat radiating flow path is disposed between the second heat radiating flow path and the second heat radiating flow path as viewed from above and below. A configuration having a flow path is employed.

  According to a fifth aspect of the present invention, there is provided an optical scanning device that emits and scans a light beam, a photosensitive member on which an electrostatic latent image is formed by irradiation with the light beam, and developing the electrostatic latent image. The image forming apparatus includes a developing device that forms a toner image, and the optical scanning device according to any one of the first to fourth inventions is employed as the optical scanning device.

According to the present invention, the heat dissipating flow path through which the fluid flows is provided in the upper part and the lower part of the housing, and the heat dissipating flow path is arranged without being overlapped when viewed from above and below, so that the heat in the housing is efficiently released. Thus, the influence on the base portion on which the light beam emitting means, the light guiding means and the deflecting means are installed is reduced.
In addition, since a heat dissipation channel through which fluid flows is formed in the housing itself, it is not necessary to provide fans above and below the housing, and it is not necessary to increase the thickness of the base part on which the optical element is installed. Even in this case, heat can be efficiently released as described above.
Therefore, according to the present invention, it is possible to reduce the thickness of the optical scanning device while reliably radiating the heat inside the housing.

1 is a cross-sectional view illustrating a schematic configuration of a copying machine according to a first embodiment of the present invention. 1 is a perspective view showing a schematic configuration of a laser scanning unit provided in a copying machine according to a first embodiment of the present invention. FIG. 2 is a bottom view of a laser scanning unit provided in the copier according to the first embodiment of the present invention. 1 is a top view of a laser scanning unit provided in a copying machine according to a first embodiment of the present invention. It is a perspective view which shows schematic structure of the laser scanning unit with which the copying machine in 2nd Embodiment of this invention is provided. (A) is a layout diagram of the heat dissipation channel of the housing, (b) is a heat distribution diagram of the top surface of the housing, and (c) is a heat distribution diagram of the bottom surface of the housing. (A) is a layout diagram of a heat dissipation channel of another housing, (b) is a heat distribution diagram of the upper surface of the housing, and (c) is a heat distribution diagram of the bottom surface of the housing. It is a graph which shows the temperature in the housing at the time of cooling, and the temperature of a polygon motor.

  Hereinafter, an embodiment of an optical scanning device and an image forming apparatus according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size. In the following description, a copying machine will be described as an example of the image forming apparatus of the present invention.

(First embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of a copying machine P according to the present embodiment. As shown in this figure, the copier P of this embodiment includes an image reading unit 1 that reads an image of a document, and a printing unit 2 that prints on a recording sheet (recording medium) based on the read image data. ing.

  The image reading unit 1 irradiates an image of a document with light and receives reflected light to read the image of the document as image data. The image reading unit 1 receives light returned from the light source device or the document that irradiates the document with light. It includes a light receiving sensor that receives light and converts it into image data.

  The printing unit 2 includes a belt unit 6, an image forming unit 7, a paper feed cassette 8, a paper feed tray 9, a secondary transfer unit 10, a fixing unit 11, a paper discharge tray 12, and a conveyance path 13. It has.

The belt unit 6 transfers the toner image formed in the image forming unit 7 and conveys the transferred toner image. The belt unit 6 includes an intermediate transfer belt 61 to which the toner image is transferred from the image forming unit 7, and an intermediate transfer belt 61. A transfer roller 61 is provided, and a driving roller 62 that drives the transfer belt 61 endlessly, a driven roller 63, and a tension roller 64 are provided.
The intermediate transfer belt 61 is stretched around a driving roller 62, a driven roller 63, and a tension roller 64.
The drive roller 62 is connected to a drive unit having a drive source such as a motor, and rotates while applying a grip force to the intermediate transfer belt 61.
The driven roller 63 is driven to rotate following the rotational drive of the drive roller 62.
The tension roller 64 is a kind of driven roller that is driven to rotate by the rotational driving of the driving roller 62, and has a spring mechanism to apply tension to the intermediate transfer belt 61.
Further, the belt unit 6 is provided with a cleaning unit (not shown) so that the toner remaining on the intermediate transfer belt 61 is removed.

  The image forming unit 7 is provided corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (BK), and forms a toner image of each color. These image forming units 7 are arranged along the intermediate transfer belt 61.

Each image forming unit 7 includes a photoreceptor 71, a charger 72, a laser scanning unit 73 (optical scanning device), a developing device 74, a primary transfer roller 75, a cleaning device 76, a neutralizing device (not shown), and the like. Have
The photosensitive member 71 is formed in a cylindrical shape, and an electrostatic latent image and a toner image based on the electrostatic latent image are formed on the peripheral surface thereof. The charger 72 is disposed to face the photoconductor 71 and charges the peripheral surface of the photoconductor 71. The laser scanning unit 73 scans the laser light emitted based on the image data in the print format on the peripheral surface of the charged photoreceptor 71. The developing device 74 develops a toner image based on the electrostatic latent image on the circumferential surface of the photoreceptor 71 by supplying toner to the circumferential surface of the photoreceptor 71. The primary transfer roller 75 is disposed opposite to the photoreceptor 71 with the intermediate transfer belt 61 interposed therebetween, and primarily transfers the toner image developed on the photoreceptor 71 to the intermediate transfer belt 61. The cleaning device 76 removes toner remaining on the photoreceptor 71 after the primary transfer.

The paper feed cassette 8 can be pulled out of the apparatus main body and accommodates recording paper. The paper feed tray 9 is openable and closable with respect to the apparatus main body, and accommodates recording paper.
The secondary transfer unit 10 performs secondary transfer of the image formed on the intermediate transfer belt 61 to a storage medium. The secondary transfer unit 10 sandwiches the drive roller 62 that drives the intermediate transfer belt 61 and the intermediate transfer belt 61 therebetween. The drive roller 62 and the secondary transfer roller 10a are arranged to face each other.
The fixing unit 11 fixes the toner image secondarily transferred onto the storage medium to the recording paper, and includes a heating roller that fixes the toner image to the recording paper by applying pressure and heating.
The transport path 13 includes a pickup roller 13 a that unloads the storage paper from the paper feed cassette 8, a paper feed roller 13 b that transports the storage medium, a paper discharge roller 13 c that discharges the storage medium to the paper discharge tray 12, and the like.

  The copying machine P of the present embodiment having such a configuration acquires image data in the image reading unit 1 as described above, and the printing unit 2 prints on recording paper based on the image data.

Next, a laser scanning unit (LSU) 73 in the copying machine P according to the present embodiment will be described with reference to FIGS. As described above, the laser scanning unit 73 is provided corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (BK), but in this embodiment, The laser scanning unit 73 provided for yellow (Y) and the laser scanning unit 73 provided for magenta (M) are integrated into a laser scanning unit 73a, which is provided for cyan (C). The laser scanning unit 73 and the laser scanning unit 73 provided for black (BK) are integrated to form a laser scanning unit 73b, which is miniaturized.
Since each laser scanning unit 73a, 73b has the same configuration, only one laser scanning unit 73a will be described in the following description.
2 is a cross-sectional view of the laser scanning unit 73a, FIG. 3 is a bottom view of the laser scanning unit 73a, and FIG. 4 is a top view of the laser scanning unit 73a.

The laser scanning unit 73a includes a housing 30, a light beam generator 31 (light beam emitting means), a polygon mirror 32, a polygon motor 33, a control board 34, and optical elements 35a to 39a and 35b to 39b. ing.
In the present embodiment, the light beam is deflected by the polygon mirror 32 and the polygon motor 33. That is, in this embodiment, the deflection means in the present invention is constituted by the polygon mirror 32 and the polygon motor 33.
In the present embodiment, the light beam is guided by the optical elements 35a to 39a and 35b to 39b. That is, in this embodiment, the light guide means in the present invention is configured by optical elements 35a to 39a and 35b to 39b.

  The housing 30 is made of a hollow box-shaped synthetic resin and includes a base portion 30a, an upper lid portion 30b, and a lower lid portion 30c, as shown in FIG.

The base 30a is provided with a light beam generator 31, a polygon mirror 32, a polygon motor 33, a control board 34, and optical elements 35a to 39a and 35b to 39b, and the upper and lower ends are open. It is considered as an end.
Moreover, the upper cover part 30b closes the upper end of the base part 30a, and the lower cover part 30c closes the lower end of the base part 30a. And each upper cover part 30b and the lower cover part 30c have the concave heat radiation flow path 30b1, 30b2, 30c1 which transfers the heat inside the housing 30 to an air flow. That is, in the copying machine P of the present embodiment, the lid portions (upper lid portion 30b and lower lid portion 30c) are arranged on the upper and lower sides of the base portion 30a, and the lid portions (upper lid portion 30b and lower lid portion 30c) are arranged. The heat dissipation channels 30b1, 30b2, and 30c1 are provided.

  More specifically, the base portion 30a is formed by integrally molding a housing substrate 30d that bisects the interior of the housing 30 and a side wall 30e of the housing 30. Near the left and right side walls 30e of the housing substrate 30d, there are provided slits 30a1 and 30a2 for allowing light beams reflected by optical elements 36a and 36b (reflection mirrors) described later to pass therethrough.

The upper end of the base portion 30a is covered with the upper lid portion 30b, and the lower end of the base portion 30a is covered with the lower lid portion 30c.
Near the both sides (left and right sides in FIG. 2) outside the upper lid portion 30b, it is parallel to the heat radiating flow channel 30c1 at a position that does not overlap with the heat radiating flow channel 30c1 provided outside the lower lid portion 30c described later. In addition, concave heat radiation channels 30b1 and 31b2 are formed over the entire upper lid portion 30b (in FIG. 4, the entire length from the upper end to the lower end).
On the outer side of the lower lid portion 30c, a concave heat radiation channel 30c1 is formed across the entire lower lid portion 30c (in FIG. 3, the whole from the upper end to the lower end) while passing through the center portion thereof. .

  That is, the laser scanning unit 73a according to the present embodiment includes a plurality of heat radiation channels 30b1, 31b2, and 31c1 that are provided at the upper and lower portions of the housing 30 and transfer heat inside the housing 30 to the fluid, and the heat radiation channels 30b1. , 31b2 and 31c1 are arranged without being overlapped when viewed from above and below.

Note that the most depressed portion of the heat dissipation channel 30c1 of the lower lid 30c (in FIG. 2, the upper end portion of the heat dissipation channel 30c1) is configured to contact the bottom surface of the housing substrate 30d. The lower lid portion 30c is provided with slits 30c2 and 30c3 for allowing light beams reflected by optical elements 39a and 39b (reflecting mirrors), which will be described later, to pass near the heat radiation channel 30c1.
That is, the housing 30 has an upper chamber X formed on the upper side thereof by the housing substrate 30d, and lower chambers Y1 and Y2 divided by the housing substrate 30d on the lower side of the housing substrate 30d.

  Here, the inside of the housing 30 is divided into two vertically by the housing substrate 30d. However, when the laser scanning unit 73a that can be placed in FIG. Divide into left and right. Therefore, in the present invention, the phrase “dividing the inside of the housing up and down” means simply dividing the inside of the housing 30 into two.

  The light beam generator 31 is fixed to the housing 30 and is fixed to the side wall 30e of the base portion 30a located on the back side of the sheet of FIG. The light beam generator 31 irradiates the polygon mirror 32 provided in the housing 30 with a light beam.

  The polygon mirror 32 deflects the light beam emitted from the light beam generator 31 and has a polygonal shape (in the illustrated example, a hexagon). The outer periphery of the polygon mirror 32 is formed of a reflection mirror, and the center position of the polygon mirror 32 is attached so as to penetrate the rotation shaft of the polygon motor 33.

  The polygon motor 33 rotates the polygon mirror 32, and is composed of a precision motor such as a DC brushless motor. The polygon motor 33 is installed on the control board 34.

The control board 34 is made of a plate material containing metal, and its planar shape is rectangular. Then, one surface side, that is, the back surface side of the control substrate 34 is fixed to the upper surface of the housing substrate 30d through four screws (not shown). Further, a polygon motor 33 is fixed on the side surface side of the control board 34.
Although omitted in FIG. 2, electronic components such as a driving IC for the polygon motor 33 are mounted on the surface side of the control board 34. The control board 34 is also provided at the central portion of the upper surface of the housing substrate 30d because the polygon mirror 32 is provided at the central portion of the upper surface of the housing substrate 30d.

Among the optical elements 35a to 39a and 35b to 39b, the optical elements 35a and 35b are fθ lenses provided in the upper chamber X, and function to form an image of the light beam emitted from the polygon mirror 32. The polygon mirror 32 is provided on the left and right sides, respectively.
The optical elements 36a and 36b are reflection mirrors, which are provided outside the optical elements 35a and 35b, respectively, and can guide the light beams emitted from the polygon mirror 32 to the lower chambers Y1 and Y2 through the slits 30c2 and 30c3, respectively. It is configured as follows.
The optical elements 37a and 37b are reflection mirrors provided in the lower chambers Y1 and Y2, respectively, and are configured to be able to irradiate the lower chambers Y1 and Y2 with light beams guided through the slits 30a1 and 30a2, respectively. .
The optical elements 38a and 38b are long lenses provided in the lower chambers Y1 and Y2, respectively, and are provided inside the optical elements 37a and 37b, respectively. These optical elements 38a and 38b act so that the light beams emitted from the optical elements 37a and 37b can be uniformly irradiated onto the photoconductor 71 without any difference in magnification.
The optical elements 39a and 39b are reflection mirrors, which are provided on the inner side of the optical elements 38a and 38b, respectively, and configured to be able to irradiate the photoreceptor 71 through the slits 30c2 and 30c3.

  In the present embodiment, the optical elements 35a to 39a and 35b to 39b are provided so as to extend in the same direction and extend in the same direction as the heat radiation channels 30b1, 30b2, and 30c1.

As shown in FIG. 1, the copying machine P of the present embodiment includes a fan device 14 that causes an air flow to flow through the heat dissipation channels 30b1 and 30b2 of the upper lid portion 30b via the duct, and a heat dissipation channel of the lower lid portion 30c. 30c1 is provided with a fan device 15 for flowing an air flow through a duct.
And in this embodiment, as shown in FIG. 2, the air flow a1 which goes to the back | inner side from the paper surface is formed in the thermal radiation flow path 30b1, 30b2 of the upper cover part 30b by these fan devices 14, 15. An air flow a2 is formed in the heat dissipation channel 30c1 of the lower lid portion 30c from the back side to the front side. That is, in the present embodiment, the flow direction of the air flow a1 that flows to the heat dissipation flow paths 30b1 and 30b2 of the upper lid portion 30b, and the flow direction of the air flow a2 that flows to the heat dissipation flow path 30c1 of the lower cover portion 30c Is the opposite.
Conventionally, there are cases in which a fan device is installed in a copying machine to cool the photoreceptor 71 or the like. In such a case, the existing fan device can also be used as one of the fan devices 14 and 15. As a result, the number of installed fan devices can be reduced and the copying machine can be miniaturized.

  As described above, in the laser scanning unit 73a according to the present embodiment, the heat radiation channel is formed to extend linearly at the upper portion of the housing 30, and the air flow (fluid) flows in one direction. 30 b 1, 31 b 2 (first heat radiating flow path) and the flow direction of the air flow formed in the lower part of the housing 30 extending linearly in parallel with the heat radiating flow paths 30 b 1, 31 b 2 and flowing through the heat radiating flow paths 30 b 1, 31 b 2 And a heat radiation channel 31c1 (second heat radiation channel) through which an air flow having a direction opposite to the flow direction flows.

  In the laser scanning unit 73a according to the present embodiment, the heat radiation channel 31c1 is disposed directly below the polygon mirror 32 and the polygon motor 33 disposed in the center of the housing 30, and the heat radiation channel 31c1 is viewed from above and below. The heat radiation flow paths 31b1 and 31b2 are arranged with being sandwiched therebetween.

  In the laser scanning units 73a and 73b configured as described above, a light beam generated based on the image data is emitted from the light beam generator 31, and this light beam is applied to the polygon mirror 32. The light beam applied to the polygon mirror 32 is scanned by the rotation of the polygon mirror 32. The scanned light beams are optical elements 35a and 35b (fθ lenses), optical elements 36a and 36b (reflective mirrors), optical elements 37a and 37b (reflective mirrors), and optical elements 38a and 38b (long lenses). In addition, the light is guided onto the photoconductor 71 through optical elements 39a and 39b (reflection mirrors). On the photoconductor 71, an electrostatic latent image is formed by the irradiated light beam based on a detection signal for determining an image writing position on the photoconductor 71.

According to the laser scanning units 73a and 73b provided in the copying machine P of the present embodiment, the heat dissipation channels 30b1, 30b, and 30c1 through which the airflow flows are provided in the upper and lower portions of the housing 30, and the heat dissipation channels 30b1, 30b, and 30c1 are provided. Therefore, the heat in the housing 30 is efficiently released, and the light beam generator 31, the polygon mirror 32, the polygon motor 33, the control board 34, The influence on the base 30a on which the optical elements 35a to 39a and 35b to 39b are installed is reduced.
Further, since the heat radiating passages 30b1, 30b, and 30c1 through which the air flow flows are formed in the housing 30 itself, it is not necessary to provide the fan devices 14 and 15 above and below the housing 30, and the base portion on which the optical elements and the like are installed. It is not necessary to increase the thickness of 30a, and even when the thickness is reduced, heat can be efficiently released as described above.
Therefore, according to the laser scanning units 73a and 73b provided in the copier P of the present embodiment, it is possible to reduce the thickness while reliably radiating the heat inside the housing 30.

Further, in the laser scanning units 73a and 73b provided in the copying machine P of the present embodiment, the heat radiation channels 30b1, 30b2, and 30c1 are provided to extend in the same direction, and the air to the heat radiation channels 30b1 and 30b2 is provided. The flow direction of the air flow a2 with respect to the flow a1 and the heat dissipation flow path 30c1 is opposite.
For this reason, in the extending direction of the heat radiation flow paths 30b1, 30b2, and 30c1, a cold air flow flows from both sides to the heat radiation flow paths 30b1, 30b2, and 30c1, whereby the laser scanning unit 73 can be cooled uniformly.

Further, in the above-described embodiment, the inside of the housing 30 guides the light beam emitted from one light beam generator 31 (lower chamber Y1) and the other light beam is generated by the heat radiating flow path 30c1. It is divided into a region (lower chamber Y2) for guiding the light beam emitted from the vessel 31.
For this reason, it is not necessary to separately provide a partition for dividing two regions (lower chamber Y1 and lower chamber Y2), and it is possible to reduce the material for forming the housing.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the description of the second embodiment, the description of the same components as those of the first embodiment is omitted or simplified.

FIG. 5 is a cross-sectional view of the laser scanning unit 73a in the present embodiment. As shown in this figure, in the copying machine P of the present embodiment, the laser scanning unit 73a is provided with a radiation fin 40 that is disposed in the radiation channel 30c1 and that transfers heat from the polygon motor 33 to the radiation channel 30c1. .
The heat radiating fins 40 are constituted by a plurality of fin members that are erected along the flow direction of the air flow a2 in the heat radiating flow path 30c1.

  By providing such heat radiation fins 40, the surface area for the air flow a2 is increased, and the heat of the polygon motor 33 can be efficiently radiated to the heat radiation flow path 30c1.

(Experimental example)
In the simulation, as shown in FIG. 6A, similarly to the above embodiment, two heat radiation channels 30b1 and 30b2 are provided on the upper surface of the housing 30, and one heat radiation channel 30c1 is provided on the bottom surface. The heat distribution of the housing 30 when providing is shown. 2B shows the heat distribution on the upper surface of the housing 30, and FIG. 2C shows the heat distribution on the bottom surface of the housing 30. Here, the portion with high brightness (portion close to white) has a high temperature, and the portion with low brightness (portion close to black) indicates that the temperature is low.
The arrows in FIGS. 7B and 7C indicate the direction in which the cooling air passes. The amount of ventilation on the top side and the bottom side is the same. This condition is the same in the case of FIG. 7 described later.

  FIG. 7 shows a simulation result for comparison with the heat distribution shown in FIG. Here, as shown in FIG. 5A, the upper surface of the housing 30 is provided with a single heat radiation channel 30b3 in parallel with the heat radiation channel 30c1 provided on the bottom surface. FIG. 2B shows the heat distribution on the top surface of the housing 30, and FIG. 3C shows the heat distribution on the bottom surface of the housing 30. Here, a portion with high brightness (portion close to white) has a low temperature, and a portion with low brightness (portion close to black) indicates that the temperature is high.

  6 (b) and (c) and FIG. 7 (b) and (c) are compared, FIG. It turns out that is excellent.

FIG. 8 is a graph showing the air temperature in the housing 30 in the form of the heat dissipation channel shown in FIG. 6 and the temperature of the polygon motor provided in the housing 30.
As is clear from this graph, the cooling effect is high when the air flows through both the heat radiation channels 30b1 and 30b2 on the top surface and the heat radiation channel 30c1 on the bottom surface. It can be seen that the opposite is the best.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above-described embodiment, the configuration in which the laser scanning unit 73 that is an example of the optical scanning device of the present invention is mounted on a copying machine that is one of the image forming apparatuses has been described.
However, the optical scanning device of the present invention is not limited to this, and may be mounted on a device such as a measuring instrument or an inspection device in addition to an image forming apparatus such as a copying machine.

  P: Copying machine (image forming apparatus), 71: Photoconductor, 73, 73a, 73b ... Laser scanning unit (optical scanning apparatus), 74: Developing apparatus, 30 ... Housing, 30a: Base section, 30b: upper lid, 30b1, 30b2 ... heat radiation channel (first heat radiation channel), 30c ... lower lid, 30c1 ... heat radiation channel (second heat radiation channel), 31: light beam generator (Light beam emitting means), 32... Polygon mirror, 33... Polygon motor, 35a, 35b... Optical element (f.theta. Lens), 36a, 36b, 37a, 37b, 39a, 39b. , 38a, 38b: optical element (long lens), 40: heat radiating member, a1, a2: air flow (fluid)

Claims (5)

A light beam emitting means for emitting a light beam, a light guide means for guiding the light beam, a deflecting means for deflecting the light beam, the light beam emitting means, the light guide means, and the deflecting means are held. An optical scanning device comprising a box-shaped housing,
A plurality of heat radiating passages are provided at the upper and lower portions of the housing and transfer heat inside the housing to the fluid, and the heat radiating passages are arranged without overlapping when viewed from above and below. An optical scanning device. The heat dissipation channel is
A first heat radiating flow path that is formed extending linearly at the top of the housing and through which a fluid flows in one direction;
A fluid is formed in the lower part of the housing so as to extend in a straight line parallel to the first heat radiating flow path and to have a flow direction opposite to the flow direction of the fluid flowing through the first heat radiating flow path. The optical scanning device according to claim 1, further comprising: 2 heat radiation channels.   3. The polygon mirror and polygon motor disposed in the center of the housing as the deflecting means, and the second heat radiation channel is disposed immediately below the polygon mirror and polygon motor. Optical scanning device.   The said heat radiating flow path has one 2nd heat radiating flow path and two 1st heat radiating flow paths arrange | positioned on both sides of the said 2nd heat radiating flow path seeing from the up-down direction. Optical scanning device. An optical scanning device that emits and scans a light beam, a photosensitive member that forms an electrostatic latent image when irradiated with the light beam, and a developer that forms a toner image by developing the electrostatic latent image An image forming apparatus comprising:
An image forming apparatus comprising the optical scanning device according to claim 1 as the optical scanning device.

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