JP2010049042A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to radiate heat from a scanning exposure device, and equipped with a housing that supports the scanning exposure device with high rigidity. <P>SOLUTION: The image forming apparatus 1 includes: image forming parts 30 each having a photoreceptor 31 on which a toner image is formed; exposure parts 33 each for scanning the photoreceptor 31 with light in accordance with image data; and the housing 70 that supports the exposure parts 33. The housing 70 includes: a hollow part that forms voids 71c and 71e; openings 73a and 73b for guiding air into the voids 71c and 71e. The hollow part is disposed around the exposure part 33. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine using an electrophotographic method, and more particularly to an image forming apparatus that performs heat dissipation from a scanning exposure apparatus.

  In general, an image forming apparatus such as a copying machine has a scanning exposure device that performs exposure while scanning a photoconductor according to image data. An optical case of the scanning exposure device includes a rotary polygon mirror, a motor, An imaging lens, a reflection mirror, and the like are accommodated. Then, the laser light from the laser light source is deflected by a rotating polygon mirror and guided to the photosensitive member by the imaging lens and the reflecting mirror to scan the photosensitive member. This rotary polygon mirror is driven by a motor.

  When the motor of the rotary polygon mirror is driven, the heat generated from the driving IC on the motor substrate and the coils constituting the stator of the motor raises the temperature of the atmosphere in the optical case. Thus, when the inside of the optical case becomes high temperature and exceeds the limit of the environmental temperature at which the motor can be used, the rotational performance of the motor deteriorates. In addition, the optical performance of optical components such as an imaging lens changes, and the image quality is significantly reduced.

  Therefore, in Patent Document 1, a laser light source, an imaging lens, a rotary polygon mirror, and the like are attached to the bottom wall of the optical case. A hollow projecting portion having a void is provided on the lower side of the bottom wall of the optical case, and this void serves as an air passage. One end of the air passage is open to one side of the optical case, and a fan for sucking air is provided. On the opposite side, a hole is provided, and a louver is provided in the vicinity of the hole. Outside air is sent to the hole from the outside of the optical case through this louver. The outside air sent to the hole flows in the air path below the bottom wall of the optical case, cools the motor and the driving IC, and sucks this air out of the optical case by the fan. This promotes heat dissipation of the motor and driving IC for rotating the rotary polygon mirror, and prevents the imaging lens and the like from being heated.

However, in recent years, printing speed has increased, and the rotary polygon mirror has to be rotated at high speed. In addition, the rotation speed of the rotary polygon mirror has been increased in order for the image forming apparatus to improve the image quality and increase the image resolution. There must be. As a result, the power consumption of the motor that rotates the rotary polygon mirror is increased, and the amount of heat generated from the motor is further increased, which requires more heat radiation from the scanning exposure apparatus than in the prior art. In addition, the image quality must be improved and high writing accuracy on the photosensitive member of the scanning exposure apparatus must be maintained. For this reason, optical components such as imaging lenses and mirrors are supported with high accuracy, and the scanning exposure apparatus is positioned with high accuracy with respect to the photosensitive member. It is necessary.
JP 11-52267 A (paragraphs [0033], [0034], FIG. 3)

  The present invention has been made to solve the above-described problems, and provides an image forming apparatus including a housing that supports the scanning exposure apparatus with high rigidity while radiating heat from the scanning exposure apparatus. For the purpose.

  To achieve the above object, the present invention provides an image forming unit having a photoconductor on which a toner image is formed, an exposure unit that optically scans the photoconductor according to image data, and a housing that supports the exposure unit. And the housing includes a hollow portion that forms a void and an opening that allows air to flow through the void, and the hollow portion is disposed around the exposure portion. .

  According to this configuration, when the motor that optically scans the photosensitive member rotates in the exposure unit, the temperature in the exposure unit rises, but the air flowing through the hollow space cools the exposure unit from its surroundings. In addition, since the casing has a hollow configuration, the exposure unit is supported with high rigidity.

  According to a second aspect of the present invention, the hollow portion is arranged in a horizontal direction of the exposure portion. According to this configuration, the air flowing through the hollow space disposed in the horizontal direction of the exposure unit cools the exposure unit from around the horizontal direction. Further, since the casing is hollow in the horizontal direction, the exposure unit is supported with high rigidity in the vertical direction.

  In the invention according to claim 3, the plurality of exposure parts are arranged in parallel in the horizontal direction, and the hollow part extends linearly along one side and the other side in the parallel direction of the plurality of exposure parts. It has the 1st empty space and the 2nd empty space which connects each said 1st empty space, It is characterized by the above-mentioned. According to this configuration, air flows through the first and second cavities of the hollow portions arranged in the horizontal direction of the plurality of exposure units, and the air cools the plurality of exposure units from around the horizontal direction. . In addition, since the casing has a hollow configuration having the first and second cavities, the plurality of exposure units are supported with high rigidity in the vertical direction.

  According to a fourth aspect of the present invention, the exposure part is formed in a substantially rectangular parallelepiped shape, and the hollow part surrounds four sides in the horizontal direction of the exposure part. According to this configuration, the air flowing through the hollow spaces arranged in the four horizontal directions of the exposure unit cools the exposure unit from the four horizontal directions. Further, since the casing is hollow in the horizontal direction, the exposure unit is supported with high rigidity in the vertical direction.

  Further, the invention according to claim 5 is characterized in that the hollow portion is formed by a main body frame forming a main configuration of the casing and an attachment frame to which the exposure portion is attached.

  According to a sixth aspect of the present invention, the apparatus further comprises a fan that exhausts the air in the void from the opening, the image forming unit is disposed in the vicinity of the housing, and the hollow portion is formed of the image forming unit. It has a flow hole through which the air of the image forming part is passed at a position opposite to. According to this configuration, the heat generated from the image forming unit including the developing device or the like is sucked into the void from the circulation hole.

  According to the first aspect of the present invention, when the motor that optically scans the photosensitive member rotates in the exposure unit, the temperature in the exposure unit rises, but the void in the hollow portion arranged around the exposure unit is removed. The flowing air can cool the exposed portion from its surroundings and prevent the exposed portion from rising in temperature. Further, since the casing has a hollow structure, the exposure unit is supported with high rigidity, so that the apparatus is lightweight and the position accuracy of the exposure unit can be stabilized.

  According to the second aspect of the present invention, the air flowing through the hollow space can cool the exposed portion from around the horizontal direction and prevent the exposed portion from rising in temperature. In addition, since the casing has a hollow structure in the horizontal direction, the exposure unit is supported with high rigidity in the vertical direction, so that the apparatus becomes lighter and the position accuracy of the exposure unit can be stabilized. .

  According to the third aspect of the present invention, air flows through the first and second cavities of the hollow portions arranged in the horizontal direction of the plurality of exposure units, and the air passes through the plurality of exposure units. Cool from around the horizontal. In addition, since the casing has a hollow configuration having the first and second cavities, the plurality of exposure units are supported with high rigidity in the vertical direction. Therefore, even when applied to a tandem type color image forming apparatus, it is possible to prevent the temperature of a plurality of exposure sections from rising, and the apparatus becomes light in weight. Position accuracy can be stabilized.

  According to the fourth aspect of the present invention, the air flowing through the voids of the hollow portions arranged in the four horizontal directions of the exposure unit cools the exposure unit from the four sides in the horizontal direction, and rises the exposure unit. Can prevent temperature. In addition, since the casing has a hollow structure in the horizontal direction, the exposure unit is supported with high rigidity in the vertical direction, so that the apparatus is lightweight and the position accuracy of the exposure unit can be stabilized. .

  According to the invention of claim 5, since the hollow portion is formed by the main body frame forming the main structure of the housing and the mounting frame to which the exposure portion is attached, the exposure portion can be easily attached. And a hollow configuration can be formed.

  According to the sixth aspect of the present invention, the heat generated from the image forming unit provided with the developing device or the like is sucked into the void from the flow hole, so that the temperature of the image forming unit is increased along with the temperature increase of the exposure unit. Can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. The embodiment of the present invention shows the most preferable form of the invention, and the use of the invention and the terms shown here are not limited thereto.

  FIG. 1 is a schematic configuration diagram of a tandem type color printer showing an embodiment of an image forming apparatus according to the present invention. In FIG. 1, the image forming apparatus 1 has a rectangular parallelepiped housing, in which a paper feeding unit 10 that accommodates paper 11 and four image forming units 30 a disposed above the paper feeding unit 10. To 30d, exposure units 33a to 33d arranged above the image forming units 30a to 30d, a fixing unit 40 arranged to the left of the image forming units 30a to 30d, and a right side of the paper feeding unit 10. The paper transport path 20 is provided, and a discharge unit 50 for discharging the paper 11 is provided at the top of the apparatus.

  The paper feed unit 10 includes a feed roller 21 that feeds the paper 11 stacked and placed in the paper feed cassette 13 one by one to the exit side (right side in FIG. 1) of the paper feed cassette 13, and transports the fed paper to the paper Paper is fed to the path 20. The paper transport path 20 includes a pair of transport rollers, a transport guide, and the like, and transports the fed paper toward the image forming units 30a to 30d. The manual feed tray 80 separately supplies paper of a size that is not placed on the paper supply unit 10 and includes a feed roller 82 and feeds the paper one by one to the paper transport path 20.

  The image forming units 30a to 30d are provided corresponding to toners of cyan, magenta, yellow, and black, respectively, in the transport direction from the upstream side (right side in FIG. 1), and are arranged in series in the horizontal direction of the apparatus. Has been placed. Each of the image forming units 30a to 30d includes cylindrical photoconductors 31a to 31d, and in order from the upstream side around the rotation direction, chargers 32a to 32d, developing devices 34a to 34d, and transfer rollers 35a to 35a. 35d and cleaners 36a to 36d are disposed.

  The rotatable photoreceptors 31a to 31d use amorphous silicon photoreceptors as photosensitive materials for forming the photosensitive layer, and are arranged corresponding to each color of cyan, magenta, yellow, and black. The photosensitive layer may be an organic photoreceptor (OPC photoreceptor). The developing units 34a to 34d are arranged on the right side of the photoconductors 31a to 31d, have a developing roller and a toner container, and supply toner to the photoconductors 31a to 31d. The chargers 32a to 32d uniformly charge the surfaces of the photoreceptors 31a to 31d.

  The exposure units 33a to 33d irradiate the surfaces of the photoconductors 31a to 31d with laser beams as indicated by broken lines in FIG. 1 based on document image data input to an image input unit (not shown) from a personal computer or the like. . Electrostatic latent images are formed on the surfaces of the photoreceptors 31a to 31d by the irradiated laser light, and the electrostatic latent images are developed by the developing units 34a to 34d.

  The sheet conveying belt 38 is stretched between the driving roller 62 and the driven roller 61, and a belt traveling path for conveying the sheet is formed between the photoreceptors 31a to 31d and the transfer rollers 35a to 35d. The transfer rollers 35a to 35d are in pressure contact with the paper conveyance transfer belt 38 so as to face the photoreceptors 31a to 31d with the paper conveyance belt 38 interposed therebetween, thereby forming a transfer nip portion. In each of the transfer nip portions, the toner images of the photoconductors 31a to 31d are sequentially transferred to the paper 11 conveyed from the paper conveyance path 20 at a predetermined timing as the paper conveyance belt 38 rotates. Are superimposed on four color toner images of cyan, magenta, yellow and black to form a color toner image.

  The toner tanks 39a to 39d are arranged above the image forming units 30a to 30d and store toners of any one of cyan, magenta, yellow, and black, respectively. The toner of each color is supplied to the corresponding developing devices 34a to 34d.

  The fixing unit 40 is disposed on the downstream side of the image forming unit 30 a, and heats and presses the paper 11 on which the toner image is transferred in the image forming units 30 a to 30 d to melt and fix the toner image on the paper 11. The paper 11 that has passed through the fixing unit 40 is discharged to the discharge unit 50 through the paper conveyance path 15.

  The cooling fan 78 is disposed on the right side of the apparatus main body 75, blows outside air to the exposure units 33a to 33d and the image forming units 30a to 30d, and generates heat to the exposure units 33a to 33d and the image forming units 30a to 30d. Cool down. A cooling fan (not shown) is also provided on the left side of the image forming unit 30a to cool the exposure units 33a to 33d and the image forming units 30a to 30d.

  The apparatus main body 75 includes a casing that supports the sheet feeding unit 10, the image forming units 30a to 30d, the exposure units 33a to 33d, the fixing unit 40, the toner tanks 39a to 39d, and the like alone or in combination. . As shown by the alternate long and short dash line in FIG. 1, the housing 70 fixes and supports the image forming units 30a to 30d and the exposure units 33a to 33d, and supports the paper transport belt 38 so as to be rotatable. Yes. Details of the housing 70 will be described later.

  Next, the exposure units 33a to 33d will be described. FIG. 2 is a perspective view showing a configuration of the exposure units 33a to 33d from which the upper case used in the image forming apparatus 1 is removed. In the following description, the configuration and operation of the exposure unit 33a opposite to the image forming unit 30a in FIG. 1 will be described. However, the configuration and operation of the exposure units 33b to 33d are the same as those of the exposure unit 33a, and the description is omitted. In addition, the reference numerals “a” to “d” indicating the exposure part and the image forming part of each color are omitted, and the reference numerals “a” to “d” are given when necessary.

  The exposure unit 33 includes a laser diode 6, a collimator lens 5, a rotary polygon mirror 2, a motor 3, a scanning optical system 4, a reflection mirror 7, a mirror 8 for detecting scanning timing, and a photosensor 9. An optical case 79 including an upper case that supports these members is provided.

  The laser diode 6 irradiates the beam light modulated by the image data, the collimator lens 5 focuses the light on the reflecting surface of the rotary polygon mirror 2 while adjusting the beam diameter of the irradiated laser light, and the rotary polygon mirror 2 The reflected light from the rotating polygon mirror 2 is deflected and scanned by the rotation, and the scanning optical system 4 scans the light beam deflected through the reflecting mirror 7 on the photosensitive member 31 at a constant speed to form an image. By this scanning (scanning in the axial direction of the photoconductor 31) and the rotation of the photoconductor 31, an electrostatic latent image is formed on the photoconductor 31.

  The motor 3 that rotationally drives the rotary polygon mirror 2 is attached to the bottom wall of the optical case 79 together with a motor drive IC (not shown), and the cylindrical lens 5 and the scanning optical system 4 are also attached to the bottom wall of the optical case 79. . The scanning optical system 4 is composed of a synthetic resin fθ lens, a toroidal lens, and the like. When the motor 3 rotates at a high speed, the temperature in the optical case 79 gradually increases from the vicinity of the motor 3, and heat is accumulated in the fθ lens and the toroidal lens.

  Next, a housing that dissipates heat in the optical case 79 and supports the exposure units 33a to 33d will be described with reference to FIGS. FIG. 3 is a perspective view showing a configuration of a housing that supports the exposure unit, FIG. 4 is an exploded perspective view showing members constituting the housing that supports the exposure unit, and FIG. 5 shows a configuration of the housing. 6 is a perspective view of the body frame to be viewed from the rear, FIG. 6 is a cross-sectional view showing the configuration of the hollow portion in the AA portion of FIG. 5, and FIG. 7 is the configuration of the hollow portion in the BB portion of FIG. FIG. 8 is a cross-sectional plan view schematically showing the air flow path in the hollow space. As shown in FIG. 3, the following description will be made assuming that the X direction of the casing is the left-right direction, the Y direction of the casing is the front-rear direction, and the Z direction of the casing is the vertical direction.

  As shown in FIG. 3, the housing 70 includes a rectangular parallelepiped main body frame 71 that forms a structure that forms the framework of the housing 70, a mounting frame 72 disposed on the upper portion of the main body frame 71, and left and right sides of the main body frame 71. The first longitudinal frame 73 and the second longitudinal frame 74 are arranged. Each of the frames 71 to 74 is formed by subjecting an iron plate to sheet metal processing such as bending, and is attached by welding. In the left-right direction of the casing 70, a pair of intake fans 78 a and a pair of exhaust fans 78 b are provided as cooling fans 78 apart from the casing 70. Exposure units 33 a to 33 d having a substantially rectangular parallelepiped shape that are long in the front-rear direction are mounted on a mounting frame 72, and an image forming unit such as a developing device (not shown) and a paper transport belt are mounted inside the main body frame 71.

  As shown in FIG. 4, the main body frame 71 includes a bent flat plate 71g provided on the rear surface, a hollow beam plate 71h provided with the front surface opened in a quadrilateral shape, and a flat plate 71i provided on the lower surface. Lower bent frames 71j and 71k, upper outer frames 71m and 71n, and flat plates 71i, which have an L-shaped cross section or a U-shaped cross section, are attached to the bent flat plate 71g and the beam plate 71h by welding or screwing. Yes.

  A lateral hollow forming portion 71b extending in the left-right direction is attached to the bent flat plate 71g on a horizontal plane substantially the same height as the upper outer frames 71m, 71n. Further, as shown in FIG. 5, on the horizontal plane that is substantially the same height as the upper outer frames 71m and 71n, a side hollow is formed extending in the left-right direction at a position opposite to the side hollow forming portion 71b (front side). The part 71a is attached. The side hollow forming portions 71a and 71b are formed in a U-shaped cross section with the upper part opened.

  Four longitudinal hollow forming portions 71d arranged at equal intervals in the left-right direction extend in the front-rear direction on the horizontal surface having substantially the same height as the upper outer frames 71m, 71n, and the side hollow forming portions 71a, 71b. Attached to. The longitudinal hollow forming part 71d is formed in a U-shaped cross section with the upper part opened. The portions of the side hollow forming portions 71a and 71b that come into contact with the long hollow forming portion 71d are punched and opened in the same shape as the U-shaped cross section of the long hollow forming portion 71d. Air between 71d and the side hollow forming portions 71a and 71b can flow.

  Returning to FIG. 4, the attachment frame 72 includes a case attachment portion 72a having a surface for supporting the exposure portions 33a to 33d, and a case insertion hole portion 72b having four holes for accommodating the exposure portions 33a to 33d. Prepare. The exposure units 33a to 33d are attached to the attachment frame 72 with screws. The attachment frame 72 is formed of a rectangular flat plate, and is attached to the main body frame 71 in contact with the upper portions of the side hollow formation portions 71 a and 71 b and the long hollow formation portion 71 d of the main body frame 71. When the attachment frame 72 is attached to the main body frame 71, the exposure portions 33a to 33d supported on the attachment frame 72 are surrounded by the side hollow formation portions 71a and 71b of the main body frame 71 and the long hollow formation portions 71d. Will be.

  Further, when the attachment frame 72 is attached to the main body frame 71, the longitudinal hollow forming portion 71 d is closed by the attachment frame 72 as shown in FIG. A hollow space 71e (referred to as a longitudinal space 71e) is formed by the U-shaped section of the longitudinal hollow forming portion 71d and the case mounting portion 72a of the mounting frame 72. This longitudinal space 71e has a hollow structure with a square cross section, is not easily deformed, increases the rigidity of the housing 70, and allows air to flow through the longitudinal space 71e. Further, two holes as flow holes 71f are arranged in the front-rear direction below the longitudinal hollow forming portion 71d (see FIG. 5), and the image forming portion is disposed below the longitudinal hollow forming portion 71d. (Not shown) and the longitudinal space 71e are also circulated so that heat of the image forming unit can be sucked. The longitudinal space 71e may be a hollow structure having a square section that is long in the vertical direction or a hollow structure having a square section that is long in the left-right direction. However, the hollow structure having a square section that is long in the vertical direction can further increase the rigidity. .

  When the attachment frame 72 is attached to the main body frame 71, the side hollow forming portions 71 a and 71 b are closed by the attachment frame 72 as shown in FIG. A hollow space 71c (referred to as a side space 71c) is formed by the U-shaped section of the side hollow forming portions 71a and 71b and the case mounting portion 72a of the mounting frame 72. The side space 71c has a hollow structure with a square cross section, is not easily deformed, increases the rigidity of the housing 70, and allows air to flow through the side space 71c. The side space 71c may have a hollow structure with a square section that is long in the vertical direction or a hollow structure with a square section that is long in the front-rear direction, but the hollow structure with a square section that is long in the vertical direction can further increase the rigidity. .

  As shown in FIG. 5, the upper outer frames 71m and 71n are provided with two intake hollow portions 71p facing the side hollow forming portion 71a. Each intake hollow portion 71p includes a space facing the side space 71c (see FIG. 7), and allows air to flow through the side space 71c. The upper outer frames 71m and 71n are provided with two exhaust hollow portions 71q so as to face the side hollow forming portion 71b. Each exhaust hollow portion 71q includes a space facing the side space 71c (see FIG. 7), and enables air to flow through the side space 71c.

  Returning to FIG. 4, the first longitudinal frame 73 has an inverted L-shaped cross section and extends in the front-rear direction, and is attached to the beam plate 71 h and the bending plate 71 g on the right side of the main body frame 71. In the first longitudinal frame 73, a hole as an intake opening 73a is formed at a position facing the empty space of the intake hollow portion 71p, and an exhaust opening 73b is formed at a position facing the empty space of the exhaust hollow portion 71q. As a hole is formed. When the first longitudinal frame 73 is attached to the main body frame 71, the strength is reinforced against the external force acting in the front-rear direction of the housing 70.

  The intake fan 78a takes outside air into the apparatus and sends the outside air to the side space 71c and the longitudinal space 71e through the intake opening 73a and the intake hollow portion 71p. The exposure part 33 is cooled from the surroundings by the air flowing through the side space 71c and the longitudinal space 71e. The exhaust fan 78b exhausts the air that has cooled the exposure unit 33 and the like to the outside of the apparatus through the exhaust hollow portion 71q and the exhaust opening 73b.

  The second longitudinal frame 74 has an inverted L-shaped cross section and extends in the front-rear direction, and is attached to the beam plate 71 h and the bending plate 71 g on the left side of the main body frame 71. In the second longitudinal frame 74, a hole as an intake opening 74a is formed at a position facing the void of the intake hollow portion 71p (see FIG. 5), and at a position facing the void of the exhaust hollow portion 71q. A hole is formed as the exhaust opening 74b. When the second longitudinal frame 74 is attached to the main body frame 71, the strength is reinforced against the external force acting in the front-rear direction of the housing 70.

  The intake fan 78a takes outside air into the apparatus and sends the outside air to the side space 71c and the longitudinal space 71e through the intake opening 74a and the intake hollow portion 71p. The exposure part 33 is cooled from the surroundings by the air flowing through the side space 71c and the longitudinal space 71e. The exhaust fan 78b exhausts the air that has cooled the exposure unit 33 and the like to the outside of the apparatus through the exhaust hollow portion 71q and the exhaust opening 74b.

  The flow of air will be described in detail with reference to FIG. A right flow passage for circulating air from the right intake fan 78a to the right exhaust fan 78b and a left flow passage for circulating air from the left intake fan 78a to the left exhaust fan 78b are formed. As described above, two partition walls 71w that block air flow are provided at positions corresponding to the space between the exposure unit 33b and the exposure unit 33c in each side space 71c.

  In the right flow passage, outside air is taken in from the intake fan 78a and flows into the intake opening 73a. The inflowing outside air flows from the side space 71c to the longitudinal space 71e as shown by the arrow in FIG. 8, and further flows to the side space 71c, thereby cooling the exposure units 33d and 33c from the surroundings. The cooled air is sucked by the exhaust fan 78b through the exhaust opening 73b and discharged out of the apparatus.

  In the exposure part 33c, outside air flows around the outer periphery, and the heat in the exposure part 33c is dissipated. In addition, outside air flows in the outer periphery of the exposure unit 33d, and heat in the exposure unit 33d is dissipated. Further, by the suction of the exhaust fan 78b, the heat of the image forming unit such as the developing device is discharged out of the apparatus from the plurality of flow holes 71f (see FIG. 5) formed in the longitudinal space 71e.

  In the left flow passage, outside air is taken in from the intake fan 78a and flows into the intake opening 74a. The inflowing outside air flows from the side space 71c to the longitudinal space 71e as shown by the arrow in FIG. 8, and further flows to the side space 71c, thereby cooling the exposure units 33a and 33b from the surroundings. The cooled air is sucked by the exhaust fan 78b through the exhaust opening 74b and discharged outside the apparatus.

  Outside air flows around the outer periphery of the exposure unit 33a, and along the outer periphery of the exposure unit 33b, along with the flow of outside air in the left flow passage, outside air flows in the longitudinal space 71e of the right flow passage, and the exposure unit 33a. , 33b is dissipated. Further, by the suction of the exhaust fan 78b, the heat of the image forming unit such as the developing device is discharged out of the apparatus from a plurality of flow holes 71f (see FIG. 5) formed in the longitudinal space 71e.

  According to the above-described embodiment, the image forming apparatus 1 includes the image forming unit 30 including the photoconductor 31 on which the toner image is formed, the exposure unit 33 that optically scans the photoconductor 31 according to image data, and the exposure unit. And a housing 70 for supporting 33. The housing 70 has hollow portions that form the spaces 71c and 71e, and openings 73a, 73b, 74a, and 74b that allow air to flow into the spaces 71c and 71e. Be placed.

  According to this configuration, when the motor 3 that optically scans the photoconductor 31 rotates in the exposure unit 33, the temperature in the exposure unit 33 rises, but the hollow space disposed around the exposure unit 33 is empty. The air flowing through 71c and 71e can cool the exposure unit 33 from its surroundings and prevent the exposure unit 33 from rising in temperature. In addition, since the housing 70 has a hollow configuration, the exposure unit 33 is supported with high rigidity, so that the apparatus is lightweight and the positional accuracy of the exposure unit 33 can be stabilized.

  Further, according to the above embodiment, the hollow portion is arranged in the horizontal direction of the exposure unit 33, so that the air flowing through the hollow spaces 71 c and 71 e cools the exposure unit 33 from around the horizontal direction, The temperature rise of the exposure unit 33 can be prevented. Further, since the housing 70 has a hollow structure in the horizontal direction, the exposure unit 33 is supported with high rigidity in the vertical direction, so that the apparatus becomes lighter and the positional accuracy of the exposure unit 33 is stabilized. be able to.

  Moreover, according to the said embodiment, the some exposure parts 33a-33d are paralleled in the horizontal direction, and a hollow part is extended linearly along one side and the other side of the parallel direction of the some exposure parts 33a-33d, respectively. It has a side space 71c (first space) and a longitudinal space 71e (second space) connecting the respective side spaces 71c (first space). As a result, the air flowing in the side space 71c and the longitudinal space 71e of the hollow portion cools the plurality of exposure portions 33a to 33d from around the horizontal direction. Further, the casing 70 has a hollow structure having a side space 71c and a longitudinal space 71e, thereby supporting the plurality of exposure portions 33a to 33d with high rigidity in the vertical direction. Therefore, even when applied to a tandem type color image forming apparatus, the temperature rise of the plurality of exposure units 33a to 33d can be prevented, and the apparatus becomes light in weight. The positional accuracy of the exposure units 33a to 33d with respect to the bodies 31a to 31d can be stabilized.

  Further, according to the above embodiment, the exposure part 33 is formed in a substantially rectangular parallelepiped shape, and the hollow part encloses the four horizontal parts of the exposure part 33, thereby forming the hollow part arranged in the four horizontal parts of the exposure part 33. The air flowing through the vacant spaces 71c and 71e can cool the exposure unit 33 from the four directions in the horizontal direction and prevent the temperature of the exposure unit 33 from rising. In addition, since the housing 70 has a hollow configuration in the horizontal direction and supports the exposure unit 33 with high rigidity in the vertical direction, the apparatus is lightweight and the positional accuracy of the exposure unit 33 is stabilized. be able to.

  Further, according to the above embodiment, the hollow portion is formed by the main body frame 71 that forms the main structure of the housing 70 and the mounting frame 72 to which the exposure portion 33 is attached. Attached and a hollow configuration can be formed.

  Further, according to the above embodiment, the exhaust fan 78 b that exhausts the air in the longitudinal space 71 e from the exhaust opening 73 b is provided, the image forming unit 30 is disposed in the vicinity of the housing 70, and the hollow portion is the image forming unit 30. Since the flow hole 71f that allows the air of the image forming unit 30 to pass therethrough is provided at a position opposite to the image forming unit 30, heat generated from the image forming unit 30 including the developing device 34 and the like is sucked from the flow hole 71f to the longitudinal space 71e The temperature rise of the image forming unit 30 can be prevented together with the temperature rise of the exposure unit 33.

  In the above embodiment, an example is shown in which the present invention is applied to a tandem type color printer having a casing that supports four exposure units separately. However, the present invention is not limited to this, and the four exposure units are grouped. The present invention may be applied to a tandem color image forming apparatus including a supporting housing, or may be applied to a monochrome image forming apparatus.

  In the above embodiment, the configuration in which the exposure unit is disposed on the upper side of the image forming apparatus has been described. However, the present invention is not limited to this, and the present invention is applied to a configuration in which the exposure unit is disposed on the lower side of the image forming apparatus. May be. In this case, the same effect as described above can be obtained.

  In the above-described embodiment, the configuration in which the housing supports the image forming unit together with the exposure unit has been described. However, the present invention is not limited to this, and the housing may support the exposure unit. In this case, the same effect as described above can be obtained.

  In the above embodiment, the cavities 71c and 71e have a hollow structure with a square cross section. However, the present invention is not limited to this, and the cavities 71c and 71e may have a hollow structure with a round cross section. In this case, the same effect as described above can be obtained.

  Further, in the above-described embodiment, the configuration in which the plurality of flow holes 71f are provided in the hollow portion forming the longitudinal space 71e is shown, but the present invention is not limited to this, and the plurality of flow holes 71f have the side space. You may make it the structure provided in the hollow part which forms 71c. When the image forming unit is arranged in the vicinity of the flow hole 71f, heat generated from the image forming unit is sucked into the side space 71c. In addition, when the fixing unit is disposed in the vicinity of the flow hole 71f, heat generated from the fixing unit is sucked.

  INDUSTRIAL APPLICABILITY The present invention can be used for an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine using an electrophotographic method, and more particularly, to an image forming apparatus that radiates heat from a scanning exposure apparatus. Can do.

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view showing an internal configuration of an exposure unit of an image forming apparatus according to an embodiment of the present invention. These are perspective views which show the structure of the housing | casing which supports the exposure part which concerns on embodiment of this invention. These are the exploded perspective views which show the structure of the housing | casing which supports the exposure part which concerns on embodiment of this invention. These are the perspective views seen from the back which show the structure of the main body frame of the exposure part which concerns on embodiment of this invention. These are sectional drawings which show the structure of the hollow part which concerns on embodiment of this invention. These are sectional drawings which show the structure of another hollow part which concerns on embodiment of this invention. These are the cross-sectional top views which show typically the flow path of the air in the space of the hollow part which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Motor 30a-30d Image forming part 31a-31d Photoreceptor 33a-33d Exposure part 70 Case 71 Main body frame 71a, 71b Side hollow formation part (hollow part)
71c Side space (first space)
71d Longitudinal hollow forming part (hollow part)
71e Longitudinal space (second space)
71f Flow hole 71m, 71n Upper outer frame 71p Air intake hollow part 71q Exhaust hollow part 71w Partition wall 72 Mounting frame (hollow part)
72a Case mounting portion 73 First longitudinal frame 73a, 74a Intake opening 73b, 74b Exhaust opening 74 Second longitudinal frame 78 Cooling fan 78a Intake fan 78b Exhaust fan 79 Optical case

Claims (6)

An image forming unit having a photoconductor on which a toner image is formed, an exposure unit that optically scans the photoconductor according to image data, and a housing that supports the exposure unit,
The image forming apparatus, wherein the housing includes a hollow portion that forms a void and an opening that allows air to flow through the void, and the hollow portion is disposed around the exposure unit.   The image forming apparatus according to claim 1, wherein the hollow portion is disposed in a horizontal direction of the exposure unit.   The plurality of exposure portions are arranged in parallel in the horizontal direction, and the hollow portion includes a first space that extends linearly along one side and the other side in the parallel direction of the plurality of exposure portions, and the respective first portions. The image forming apparatus according to claim 1, further comprising a second space that connects the spaces.   The image forming apparatus according to claim 1, wherein the exposure part is formed in a substantially rectangular parallelepiped shape, and the hollow part surrounds four sides in the horizontal direction of the exposure part.   The image according to any one of claims 1 to 4, wherein the hollow portion is formed by a main body frame that forms a main configuration of the casing and an attachment frame to which the exposure unit is attached. Forming equipment.   A fan for exhausting air in the void from the opening; the image forming unit is disposed in the vicinity of the housing; and the hollow portion is located at a position facing the image forming unit. The image forming apparatus according to claim 1, further comprising a flow hole through which the air passes.

Images