JP5315733B2 - Optical scanning apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the heat generation in an optical scanner by efficiently cooling an optical deflector. <P>SOLUTION: A polygon scanner 10 housed in an optical housing 11 is arranged at an open part 13 provided on the bottom face 11a of the housing. A temperature control unit 12 is arranged at a position which is opposite to a rotating polygon mirror 14 with respect to a polygon scanner substrate 15 and corresponding to the polygon scanner 10, and the temperature control unit 12 directly cools the polygon scanner 10. The temperature control unit 12 is held so as not to be made contact with the polygon scanner 10 (and the optical scanner), thus the influence of vibration and heat or the like is reduced. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an optical scanning device used for a writing system such as a digital copying machine and a laser printer, and an image forming apparatus equipped with the optical scanning device.

JP 2004-160747 A

  In recent years, image forming apparatuses have been required to increase the printing speed and reduce the size of the apparatus. However, as speed increases and miniaturization advances, an increase in the amount of heat generated by the machine and heat storage inside the machine have become problems. As one of the heat sources, there is heat generated by a deflector that is a component of the optical scanning device. For example, a polygon scanner widely used as a rotating deflector easily generates heat because a polygon mirror is rotated at a high speed.

  With respect to the heat generated by the deflector, measures such as making the housing cover of the optical scanning device into a sheet metal or providing a cooling mechanism to exhaust heat to the outside of the device have been proposed (for example, Patent Document 1).

  However, it is difficult to efficiently cool the deflector housed in the housing of the optical scanning device. In the configuration in which the deflector is indirectly cooled, the supply amount of the coolant supplied by the cooling mechanism and the driving of the cooling mechanism are difficult. It is natural that heat is not released to the outside of the device if the amount of water is not sufficient. Due to a large loss in the supply path, there is a problem that a targeted effect cannot be expected and a sufficient heat dissipation effect may not be obtained.

  The present invention solves the above-mentioned problems in the conventional optical scanning device and image forming apparatus, can cool the deflector efficiently, and can suppress heat generation in the optical scanning device and image formation. It is an object to provide an apparatus.

According to the present invention, there is provided a light that houses an optical deflector in an optical housing, deflects a light beam from a light source by the optical deflector, and scans a surface to be scanned of an image carrier via an optical system. In the scanning device, the optical deflector is disposed facing an opening provided in the optical housing, and temperature adjusting means for directly cooling the optical deflector is disposed so as not to contact the optical deflector. The temperature adjusting means is mounted on and supported by a plate-like support member and is disposed opposite to the opening at a position corresponding to the optical deflector, and the cooling medium passes through the plate-like support member. A medium passage opening is formed, a convex portion is formed on the plate-like support member, the temperature adjusting means is placed on the convex portion, and above the support member surface on which the medium passage opening is formed. The temperature control means is supported by It is resolved by the.

Further, it is preferable that the plate-like support member functions as a partition member that partitions the optical scanning device and a paper feeding unit of the image forming apparatus on which the optical scanning device is mounted.

Further, it is preferable that the medium passage opening is disposed within a projection range when the temperature adjusting means is projected onto the plate-like support member.

Also, the medium passage opening is arbitrarily favored length of round or long side portion of diameter less than 2mm is less shape 2mm.

Moreover, it is preferable that the upper surface of the convex portion and the temperature adjusting means are in close contact with each other.
The optical deflector includes a rotating polygon mirror, a driving unit for driving the rotating polygon mirror, and a substrate on which a driving circuit for the driving unit is mounted, and the substrate is disposed so as to face the opening. Preferably.

Further, it is preferable that the temperature adjusting means is disposed on the opposite side of the rotary polygon mirror with the substrate interposed therebetween.
The temperature adjusting means is preferably a cooling fan.

Moreover, it is preferable to introduce cooling air from the cooling fan through a relay duct.
In addition, according to the present invention, the above problem is solved by an image forming apparatus including the optical scanning device according to any one of claims 1 to 12.

According to the optical scanning device of the present invention, the optical deflector is disposed facing the opening provided in the optical housing, and the temperature adjusting means for directly cooling the optical deflector is disposed so as not to contact the optical deflector. Thus, the optical deflector can be efficiently cooled and the influence of heat, vibration, etc. from the temperature adjusting means on the optical deflector can be suppressed or prevented.
In addition, since the temperature adjusting means is mounted and supported on the plate-like support member and is disposed opposite the opening at a position corresponding to the optical deflector, effective cooling of the optical deflector can be realized with a simple configuration. be able to.
Further, since the medium passage opening through which the cooling medium passes is formed in the plate-like support member, efficient cooling can be performed with a simple configuration.
Moreover, the cooling medium taken in from the medium passage opening can be efficiently sent to the temperature adjusting means.

According to the second aspect of the present invention, it is possible to partition the paper feed unit and the optical scanning device of the image forming apparatus with a plate-like support member and prevent the dust and toner from falling.

According to the configuration of the third aspect , the cooling medium can be taken in efficiently, and the cooling efficiency can be improved.
According to the configuration of the fourth aspect , it is possible to prevent the tool or other members from entering and prevent the optical scanner from being deteriorated in accuracy or damaged.

According to the configuration of the fifth aspect, a cooling medium conveyance path is formed between the temperature adjusting means and the plate-like support member, and the cooling medium can be sent to the temperature adjusting means more efficiently.

According to the configuration of the sixth aspect , the substrate of the optical deflector can be efficiently cooled.
With the configuration of the seventh aspect , the substrate of the optical deflector can be efficiently cooled without being affected by the rotary polygon mirror.

According to the configuration of the eighth aspect , the optical deflector can be cooled at low cost with a simple configuration by the cooling fan.
With the configuration of the ninth aspect , fresh air outside the apparatus can be taken in and the optical deflector can be efficiently cooled.

According to the image forming apparatus of the tenth aspect , it is possible to suppress the heat generation in the optical scanning apparatus to prevent the temperature inside the image forming apparatus from increasing, and to realize a small-sized and excellent productivity image forming apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing the vicinity of a deflector in an example of an optical scanning device according to the present invention. In this figure, optical elements such as a light source unit and lenses / mirrors provided in the optical scanning device are not shown. Further, the top plate or upper cover of the optical housing is omitted and the inside of the housing is visible. As shown in FIG. 1, a polygon scanner 10 as an optical deflector is provided in an optical housing 11. A temperature control device 12 is attached to the bottom surface of the optical housing 11.

  As shown in FIG. 2, an opening 13 is provided in the bottom plate 11 a of the optical housing 11, and the polygon scanner 10 is mounted on the optical housing 11 so that the substrate 15 of the polygon scanner 10 is positioned on the opening 13. Fixed. The bottom surface of the substrate 15 on which the polygon scanner drive circuit and the like are mounted is exposed to the outside of the optical unit through the opening 13.

  The temperature adjustment device 12 is disposed on the opposite side of the polygonal mirror 14 with respect to the substrate 15 of the polygon scanner 10 and at a position corresponding to the polygon scanner 10, and is disposed inside the optical housing 11. The polygon scanner 10 is provided so that it can be directly cooled. The temperature adjustment device 12 can cool the polygon scanner 10 directly, so that the temperature can be adjusted efficiently.

  FIG. 3 is a cross-sectional view of the optical scanning device in the main scanning direction. As shown in this figure, the temperature control device 12 is supported and mounted on a plate-like member 16. The plate-like member 16 can be configured as a partition plate that partitions an image forming unit and a paper feeding unit in an image forming apparatus, for example. The plate-like member 16 of this example holds the temperature adjusting device 12 so as not to contact the polygon scanner 10 (and the optical scanning device). As a result, the temperature adjusting device 12 reduces or prevents factors that affect the optical deflector, such as vibration and heat.

  FIG. 4 is a schematic diagram of the plate-like member 16 that supports the temperature control device 12. In this drawing, the plate-like member 16 is shown as a single flat plate-like member, but when used in an actual machine, it is formed in a shape corresponding to the actual machine as shown in FIG. Now, as schematically shown in FIG. 4, a large number of small openings 17 are formed in the plate-like member 16 that supports the temperature control device 12. In the illustrated example, the large number of openings 17 are arranged in a “cross” shape. When the temperature control device 12 is a fan, air as a cooling medium is taken in from the opening 17 and blown into the polygon scanner 10 (the lower surface of the substrate 15) by the fan, thereby serving as an optical deflector. The temperature of the polygon scanner 10 is adjusted.

  As shown in FIG. 5, the numerous openings 17 are disposed so as to be within the installation range of the temperature control device 12. Thereby, it becomes possible to take in the air which is a cooling medium efficiently, and it can make cooling efficiency favorable. When the opening is also outside the installation range of the temperature control device 12, the air taken in from the opening (opening outside the installation range) circulates around the opening and is efficiently sent to the cooling target (polygon scanner 10). In some cases, the cooling efficiency may be reduced.

  Further, in this example, the openings 17 are circular in which each opening has a diameter of 2 mm or less, prevents entry of tools such as a driver and other members, and optical scanning that requires high-precision positioning. The influence on the apparatus can be prevented. At the same time, it is possible to prevent foreign matter from dropping from the image forming apparatus image forming unit to the paper supply unit or the like. The shape of the opening 17 is not limited to a circle, and may be an elliptical shape or a polygonal shape. In that case, it is preferable that the length of the long side portion is 2 mm or less.

  FIG. 6 is a perspective view showing a state in which the temperature adjusting device 12 is mounted and supported on the plate-like member 16. As shown in FIGS. 6 and 3, the plate-like member 16 is formed with a convex portion 16a protruding upward, and the temperature control device 12 is placed on and supported on the convex portion 16a. Is done. In this example, the convex portion 16a has a rectangular shape in the plan view, and the central portion is recessed, and the opening 17 is formed in the central concave portion. As can be seen from FIG. 3, the upper surface of the convex portion 16a is in close contact with the temperature control device 12 (the lower surface thereof), and a space is formed between the opening 17 and the temperature control device 12, and this space serves as a medium transmission path. It has become. Further, since the convex portion 16a of the plate-like member protrudes upward, a space 18 is also formed below the convex portion 16a, and the medium transmission path is also provided outside the plate-like member 16. Is formed. Thereby, it is possible to efficiently take in air as a cooling medium. In addition, the ridgeline part of the convex part 16a is not restricted to the square shape like the example of illustration, A curved shape may be sufficient.

  FIG. 7 shows an example of a configuration that regulates the positioning and rotation of the temperature control device 12 to the plate-like member 16. In the illustrated example, a plurality of protrusions 19 are provided on the plate-like member 16B at positions where they contact the outer surface of the temperature adjustment device 12, and the positioning and rotation regulation of the temperature adjustment device 12 are performed by the plurality of protrusions 19. It is composed. You may provide this some protrusion 19 on the convex part 16a of the plate-shaped member 16 shown to FIG.

  FIG. 8 is a perspective view showing a second embodiment of the optical scanning device. FIG. 9 is a perspective view of the optical scanning device viewed from below. The second embodiment shown in this figure is the same as the first embodiment except that the temperature of the polygon scanner 10 as an optical deflector is adjusted from the temperature adjusting device 12 via the relay duct 20. is there. When the temperature control device 12 is a fan, air as a cooling medium is guided to the opening 13 of the optical housing 11 through the relay duct 20 to cool the polygon scanner 10 exposed outside the optical housing 11 from the bottom surface. .

  For example, the polygon scanner 10 can be effectively cooled by introducing fresh air outside the apparatus by disposing the temperature adjusting device 12 on the front or side of the apparatus and cooling the polygon scanner 10 via the relay duct 20. .

  The relay duct 20 (and the temperature control device 12) is supported and mounted on a plate-like member (not shown) as in the first embodiment, so that the relay duct 20 and the temperature control device 12 are in contact with the polygon scanner 10. Not to be held. As a result, it is possible to reduce or prevent factors that the temperature adjusting device 12 affects the optical deflector, such as vibration and heat.

  As described above, the optical scanning device according to the present invention is provided such that (a part of) the optical deflector is exposed to the outside of the optical housing, and the optical deflector can be directly cooled by the temperature adjusting device. Therefore, the temperature of the optical deflector can be adjusted efficiently, and the heat generation of the deflector can be effectively suppressed.

  Heretofore, the temperature adjustment device has been described as an air-cooling type, but a liquid-cooling type temperature adjustment device can also be adopted. For example, a portion exposed to the outside of the optical housing of the optical deflector may be directly cooled using a heat pipe.

Finally, an image forming apparatus including an optical scanning device according to the present invention will be described with reference to FIG.
FIG. 10 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus including the optical scanning device according to the present invention. Here, the optical scanning device is shown as being mounted with the first embodiment described above, but the optical scanning device according to the second embodiment using the relay duct 20 can also be mounted. It is also possible to employ a liquid cooling type temperature control device.

  The image forming apparatus shown in FIG. 10 is configured as an intermediate transfer type tandem type full-color printer, and an intermediate transfer belt 5 wound around a plurality of rollers is disposed at a substantially central portion of the apparatus main body. The four image forming units 2 (M, C, Y, Bk) are arranged along the lower running side of the intermediate transfer belt 5.

  Each image forming unit 2 includes a photosensitive drum 1 as an image carrier. Around the photosensitive drum 1, a charging unit, a developing device, a cleaning unit, and the like are arranged, and a transfer roller as a primary transfer unit is provided inside the intermediate transfer belt 5 at a position facing each photosensitive drum 1. It has been. In the case of this example, the four image forming units 2 have the same structure, but the developer colors handled by the developing devices of the respective image forming units are different from four colors of magenta, cyan, yellow, and black. . In the case of this example, the four image forming units 2 are arranged in the order of magenta, cyan, yellow, and black from the left in the drawing. Each image forming unit 2 is detachably provided as a process cartridge in the apparatus main body.

  An optical scanning device 100 is provided below the image forming unit 2. This optical scanning device 100 has one deflector 10 in the center, and the light beams from the four light sources are deflected and scanned by the four deflectors 10 into four systems, and four photosensitive drums 1Y, 1C, 1M, A latent image is written in 1 Bk. Four laser diode (LD) light sources prepared for each color, an optical system for collimating a laser beam emitted from the light source, and a polygon mirror (rotating polygon mirror) And a rotary deflector (polygon scanner) 10 composed of a polygon motor and an optical system composed of a scanning / imaging lens such as an fθ lens, a correction lens, and a mirror disposed in the optical path of each light source. Has been. The laser light emitted from the laser diode in accordance with the image information of each color is deflected and scanned by the polygon scanner 10 and irradiated to the photosensitive drums 1Y, 1C, 1M, and 1Bk of each color.

  In addition, a toner bottle 3 containing toner for replenishing the developing device of each image forming unit is provided at the uppermost part inside the apparatus. Each toner bottle 3 is filled with toners of yellow (Y), cyan (C), magenta (M), and black (Bk) from the left in the drawing, and a predetermined replenishment amount from here through a conveyance path (not shown). Only the toner of each color is supplied to the developing device of each color image forming unit.

  The paper feed unit 9 at the lower part of the apparatus body is provided with a two-stage paper feed cassette that stores transfer paper as a recording material, and the transfer paper is selectively fed from one of the paper feed cassettes. The paper is fed toward the registration roller 7 through the conveying roller. The transfer sheet fed to the registration roller 7 is sent out at a predetermined timing toward the secondary transfer portion where the transfer counter roller 4 and the secondary transfer roller 6 face each other. A fixing unit 8 is installed above the secondary transfer roller 6. In the fixing unit 8, for example, a fixing roller and a pressure roller are provided. The upper surface of the apparatus main body is configured as a paper discharge tray.

An image forming operation in the full color printer of this example configured as described above will be briefly described.
The photosensitive drum 1 of the image forming unit 2 is rotated in the clockwise direction in the figure by a driving unit (not shown), and the surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity by the charging unit. The charged photoconductor surface is irradiated with laser light from the optical scanning device 100, whereby an electrostatic latent image is formed on the photoconductor drum 1 surface. At this time, the image information exposed on each photosensitive drum 1 is single-color image information obtained by separating a desired full-color image into color information of yellow, magenta, cyan, and black. Each color toner is applied from the developing device to the electrostatic latent image formed in this way, and visualized as a toner image.

  Further, the intermediate transfer belt 5 is driven to run counterclockwise in the drawing as indicated by the arrow, and the toner images of the respective colors are sequentially superimposed on the intermediate transfer belt 5 from the photosensitive drum 1 by the action of the primary transfer roller in each image forming unit 2. Transcribed. In this way, the intermediate transfer belt 5 carries a full-color toner image on its surface.

  A single color image can be formed using any one of the color image forming units 2, or a two-color or three-color image can be formed using a plurality of image forming units. In the case of monochrome printing, image formation is performed using the rightmost Bk unit in the figure among the four image forming units.

  The residual toner adhering to the surface of the photosensitive drum after the toner image is transferred is removed from the surface of the photosensitive drum by the cleaning means, and then the surface is subjected to the action of the static eliminator to initialize the surface potential. Ready for image formation.

  On the other hand, the transfer paper is selectively fed from the paper supply unit 9 and sent to the secondary transfer position by the registration roller pair 7 in timing with the toner image carried on the intermediate transfer belt 5. . In this example, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the surface of the intermediate transfer belt is applied to the transfer roller 6, whereby the toner image on the surface of the intermediate transfer belt is collectively transferred onto the paper. When the sheet on which the toner image has been transferred passes through the fixing device 8, the toner image is fused and fixed to the sheet by heat and pressure. The transfer sheet on which the toner image is fixed is discharged to a discharge tray formed on the upper surface of the apparatus main body by a discharge roller.

  As described above, since the deflector 10 of the optical scanning device 100 is directly cooled by the temperature adjusting device 12, even the rotary deflector that rotates the polygon mirror at high speed is efficiently cooled. Heat generation is effectively suppressed. Further, since the temperature adjusting device 12 is supported by the plate-like member 16 and is held so as not to come into contact with the deflector 10, the influence on the optical deflector such as heat and vibration from the temperature adjusting device 12 is reduced. Or prevented. Further, the plate-like member 16 partitions the image forming unit and the paper feeding unit 9 so that the image forming unit is made into an enclosure, and dust, toner, and the like can be prevented from falling on the paper feeding unit 9.

As mentioned above, although this invention was demonstrated by the example of illustration, this invention is not limited to this.
The deflector of the optical scanning device may have a single polygonal mirror. Further, the scanning is not limited to the multi-beam method, and scanning with a single beam may be used. The arrangement of optical elements provided in the optical scanning device and the shape of the optical housing are also arbitrary. In addition, a temperature control device having an appropriate configuration can be used. The shape and size of the plate-like member that supports the temperature control device can also be set as appropriate. When a duct is used, the shape, size, material, and the like of the duct are arbitrary and can be appropriately configured according to the present invention.

  Further, the image forming apparatus including the optical scanning device is not limited to the illustrated printer, and may be a copying machine, a facsimile, or a multifunction machine having a plurality of functions. Not only the intermediate transfer method but also a direct transfer method device is possible. Further, the image forming method, the number of colors, and the like are not limited to the tandem type.

It is a perspective view which shows the deflector vicinity in an example of the optical scanner which concerns on this invention. It is the perspective view which looked at the optical scanning device from the lower part. It is sectional drawing of the main scanning direction of an optical scanning device. It is a schematic diagram of the plate-shaped member which supports a temperature control apparatus. It is a top view which shows arrangement | positioning of the opening provided in the plate-shaped member. It is a perspective view which shows a mode that the temperature control apparatus was mounted | worn and supported by the plate-shaped member. An example of the structure which controls the positioning and rotation to the plate-shaped member of a temperature control apparatus is shown. It is a perspective view which shows 2nd Example of an optical scanning device. It is the perspective view which looked at the optical scanning device from the lower part. 1 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus including an optical scanning device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Image forming unit 5 Intermediate transfer belt 8 Fixing unit 9 Paper feed part 10 Polygon scanner (optical deflector)
DESCRIPTION OF SYMBOLS 11 Optical housing 12 Temperature control device 13 Aperture 14 Rotating polygon mirror (polygon mirror)
15 Substrate 16 Plate-like member 16a Convex part 17 Opening (medium passage opening)
20 Relay duct 100 Optical scanning device

Claims (10)

In an optical scanning device that houses an optical deflector in an optical housing, deflects a light beam from a light source by the optical deflector, and scans a scanned surface of an image carrier via an optical system.
While arranging the optical deflector facing the opening provided in the optical housing,
A temperature adjusting means for directly cooling the optical deflector is provided so as not to contact the optical deflector,
The temperature adjusting means is mounted and supported on a plate-like support member and is disposed to face the opening at a position corresponding to the optical deflector,
The plate-like support member is formed with a medium passage opening through which a cooling medium passes,
A convex portion is formed on the plate-like support member, the temperature adjusting means is placed on the convex portion, and the temperature adjusting means is supported above the support member surface on which the medium passage opening is formed. An optical scanning device characterized by comprising: 2. The optical scanning according to claim 1, wherein the plate-like support member functions as a partition member that partitions the optical scanning device and a paper feeding unit of an image forming apparatus on which the optical scanning device is mounted. apparatus. 2. The optical scanning device according to claim 1, wherein the medium passage opening is disposed within a projection range when the temperature adjusting unit is projected onto the plate-like support member.   4. The optical scanning device according to claim 1, wherein the medium passage opening has a circular shape with a diameter of 2 mm or less or a shape with a long side portion having a length of 2 mm or less. 5.   The optical scanning device according to claim 1, wherein an upper surface of the convex portion and the temperature adjusting unit are in close contact with each other.   The optical deflector includes a rotating polygon mirror, a driving unit for driving the rotating polygon mirror, and a substrate on which a driving circuit for the driving unit is mounted, and the substrate is disposed so as to face the opening. The optical scanning device according to claim 1, wherein:   The optical scanning device according to claim 6, wherein the temperature adjusting unit is disposed on the opposite side of the rotary polygon mirror with the substrate interposed therebetween.   The optical scanning device according to claim 1, wherein the temperature adjusting unit is a cooling fan.   9. The optical scanning device according to claim 8, wherein cooling air is introduced from the cooling fan through a relay duct.   An image forming apparatus comprising the optical scanning device according to claim 1.

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