JP2017053895A - Scanning optical device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning optical device that can reduce the volume of a heat radiation member and the volume of a channel for cooling compared with a prior art scanning optical device for the purpose of cooling the periphery of a polygon mirror, and an image forming apparatus including the same.SOLUTION: A scanning optical device 14 comprises a cooling fan 90 and a heat radiation component 80. The cooling fan 90 cools a housing 60 having a polygon mirror 42 stored therein. The heat radiation component 80 cools a motor part 44 that drives the polygon mirror 42. At least a part of a channel for an airflow generated by the cooling fan 90 passes through a top face S3 of the housing 60. The heat radiation component 80 is in contact with a bottom face S1 of the housing 60 and drawn from the bottom face S1 toward the channel for an airflow generated by the cooling fan 90.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a scanning optical apparatus and an image forming apparatus, and more particularly to a scanning optical apparatus using a polygon mirror and an image forming apparatus including the same.

  Image data read by the scanner and image data transmitted from the PC terminal are formed as an image on the surface of the photosensitive drum of the image forming apparatus using laser light. Specifically, the image data is converted into ON / OFF information of laser light by a control unit provided in the image forming apparatus and sent to the scanning optical device. In the scanning optical device, based on the ON / OFF information of the laser beam sent from the control unit, the laser beam is emitted from a laser oscillator provided in the scanning optical device. The emitted laser light is narrowed down through the lens and then reflected by a polygon mirror that rotates at high speed. Then, an image is formed on the photosensitive drum by the laser light reflected by the polygon mirror.

  By the way, as described above, the polygon mirror rotates at high speed. Therefore, the bearing of the motor portion that drives the polygon mirror tends to be hot. Further, since the polygon mirror and the motor portion for driving the polygon mirror are housed in a highly airtight housing for the purpose of dust prevention and the like, the heat generated from the motor portion is scattered in the housing and is not easily radiated. In order to cope with this, for example, in a scanning optical device (hereinafter referred to as a conventional scanning optical device) described in Patent Document 1, not only cooling a housing in which a polygon mirror or the like is accommodated but also a motor portion A heat conducting member provided with fins is attached to the bearing side of this, and cooling is also performed. However, in the conventional scanning optical device, it is necessary to secure a cooling air blowing means and a flow path for each of the heat conducting members including the housing and the fin in which the polygon mirror is accommodated, which increases the size and cost of the device. Invited to increase.

JP 2001-242408 A

  An object of the present invention relates to cooling around a polygon mirror, and a scanning optical device capable of reducing the volume of a heat radiation member and the volume of a cooling flow path as compared with a conventional scanning optical device, and an image forming apparatus including the same Is to provide.

The scanning optical apparatus according to the first aspect of the present invention is
A scanning optical apparatus using a polygon motor including a polygon mirror and a motor unit for driving the polygon mirror,
A blowing means for cooling the housing in which the polygon mirror is housed;
A first heat dissipating component for cooling the motor unit;
With
At least a part of the flow path of the air generated by the air blowing means passes through one surface of the housing that intersects with the extension line of the rotation shaft of the motor unit,
The first heat dissipating part is in contact with the other surface of the housing intersecting with an extension line of the rotating shaft of the motor unit, and is extended from the other surface toward the flow path;
It is characterized by.

An image forming apparatus according to a second aspect of the present invention is
Comprising the scanning optical device;
It is characterized by.

  In the scanning optical device according to the first aspect of the present invention, the first heat dissipating component for cooling the motor unit is provided in the air flow path generated by the air blowing means for cooling the housing in which the polygon mirror is housed. It is stretched toward. Thereby, the blowing means for cooling the housing can be used as the blowing means for cooling the first heat radiation component for cooling the motor unit. Therefore, it is not necessary to provide a cooling air blowing means and a flow path for each of the housing for housing the polygon mirror and the first heat radiation component for cooling the motor unit. As a result, in the scanning optical device according to the first embodiment of the present invention, the volume of the heat dissipation member and the volume of the cooling channel can be reduced as compared with the conventional scanning optical device.

  According to the scanning optical device of the present invention, the volume of the heat radiating member and the volume of the cooling channel can be reduced as compared with the conventional scanning optical device.

1 is a schematic diagram illustrating an internal structure of an image forming apparatus according to an embodiment. It is a perspective view which shows the scanning optical apparatus which concerns on one Example, and is a figure which shows the inside of this scanning optical apparatus in the state which removed the heat radiating component located in the top | upper surface of a housing. It is the perspective view which looked at the periphery of the laser light source enclosed with the broken line of FIG. 2 from the negative direction side (lower side) of the z-axis direction. It is sectional drawing of the scanning optical apparatus which concerns on one Example. 1 is a perspective view showing a scanning optical device and its surroundings according to one embodiment. It is a perspective view which shows the attachment state to the housing of the thermal radiation component which cools a motor part. It is the front view which looked at the thermal radiation component which cools a motor part from the direction of the cooling fan. It is a perspective view which shows the thermal radiation component which cools a motor part, and its periphery, Comprising: It is a figure which shows the flow path formed with a cooling fan.

  Hereinafter, an image forming apparatus 1 according to an embodiment will be described with reference to the accompanying drawings. In each figure, the same code | symbol is attached | subjected about the same member and part, and the overlapping description is abbreviate | omitted. 2 to 8, the horizontal direction of the image forming apparatus 1 is represented by the x axis, and the depth direction is represented by the y axis. Further, the vertical direction is represented by the z-axis.

(Schematic configuration of image forming apparatus, see FIG. 1)
As shown in FIG. 1, the image forming apparatus 1 is a tandem electrophotographic printer, and includes a control unit 4 that controls each unit and each unit of the image forming apparatus 1, Y (yellow), M (magenta), and C ( An imaging unit 10 for forming toner images of each color of cyan and K (black) and an intermediate transfer unit 20 are provided.

  Each of the imaging units 10 is provided with a charging charger 12, a developing device 13 and the like centered on the photosensitive drum 11, and is statically drawn on each photosensitive drum 11 by light emitted from the scanning optical device 14. The electrostatic latent image is developed by moving negatively charged toner from the developing device 13 to the photosensitive drum 11 to form toner images of the respective colors.

  The intermediate transfer unit 20 includes an intermediate transfer belt 21 that is rotationally driven endlessly in the direction of the arrow W, and an electric field applied from the primary transfer roller 22 that faces each of the photosensitive drums 11 causes each of the photosensitive drums 11 to be The toner images formed in the above are primarily transferred onto the intermediate transfer belt 21 and synthesized.

  In the lower part of the apparatus main body, an automatic paper feeding unit 30 for feeding paper one by one is disposed. The toner image (synthesized color image) is secondarily transferred by the electric field applied to the nip portion and applied from the secondary transfer roller 25. Thereafter, the sheet is conveyed to the fixing unit 35 where the toner is heated and fixed, and is discharged to the tray portion 2 disposed on the upper surface of the apparatus main body.

(Refer to FIG. 2 to FIG. 4 for the basic structure of the scanning optical device)
Hereinafter, the scanning optical device 14 provided in the image forming apparatus 1 will be described. As described above, the scanning optical device 14 draws an electrostatic latent image on each photosensitive drum 11 by the laser light emitted from the scanning optical device 14. As shown in FIGS. 2 and 3, the scanning optical device 14 includes a laser light source 40, a polygon mirror 42, and a motor unit 44 inside a housing including a unit case 37 and a housing 60 adjacent thereto. A polygon motor 41 and a plurality of lenses and mirrors.

  The laser light source 40 is a light source including semiconductor lasers such as a plurality of VCSELs (vertical cavity surface emitting lasers) and edge emitting lasers. Further, as shown in FIG. 3, the laser light oscillated from the laser light source 40 passes through a collimator lens 72 provided around the laser light source 40, is reflected by mirrors 74 and 76, and further is a cylindrical lens 78. Is passed through the polygon mirror 42.

  The polygon mirror 42 is a rotating polygonal mirror made of aluminum or the like and having a plurality of reflecting surfaces that reflect the laser light emitted from the laser light source 40. The polygon mirror 42 forms a regular polygon when viewed in plan from the rotation axis direction.

  As shown in FIG. 4, the motor unit 44 has an output shaft 46 that is provided below the polygon mirror 42 and extends vertically upward. A polygon mirror 42 is connected to the output shaft 46. Therefore, when the rotor 45 of the motor unit 44 rotates, the output shaft 46 also rotates, and as a result, the polygon mirror 42 rotates. A bearing 48 for the output shaft 46 is provided at the lower portion of the motor unit 44. The bearing 48 passes through the substrate 50 on which the rotor 45 is placed, and a lower end thereof further protrudes from the bottom surface S <b> 1 of the housing 60.

  The substrate 50 is a rectangular plate material on which the rotor 45 is placed. The substrate 50 is provided with a drive circuit that drives the rotor 45. Further, the lower surface of the substrate 50 is fixed to the housing 60 with four bolts.

  As shown in FIG. 2, the housing 60 is a box-shaped member formed integrally with the unit case 37, and is made of resin. A polygon motor 41 having a polygon mirror 42 and a motor unit 44 is housed inside the housing 60. Further, the housing 60 has a structure that is kept as airtight as possible in order to prevent the mirror surface of the polygon mirror 42 from being soiled by dust or dust and the irregular reflection of the laser light. However, in order to guide the laser beam reflected by the polygon mirror to the photosensitive drum 11, a rectangular window W1 is provided on the surface of the housing 60 adjacent to the unit case 37. Further, as shown in FIG. 3, a window W <b> 2 for allowing the laser light to pass therethrough is also provided on the path from the laser light emitted from the laser light source 40 to the polygon mirror 42.

  In the scanning optical device 14 configured as described above, the laser light is emitted from the laser light source 40 based on the ON / OFF information of the laser light sent from the control unit 4. The emitted laser light is reflected by the polygon mirror 42 that rotates at high speed. The laser light reflected by the polygon mirror 42 passes through a window W1 provided in the housing 60 and then forms an image on the photosensitive drum 11 through a plurality of lenses and mirrors (not shown).

(Refer to FIGS. 4 to 8 for the cooling mechanism of the scanning optical device)
The scanning optical device 14 forms an electrostatic latent image on the surface of the photosensitive drum 11 using a polygon mirror 42 that rotates at high speed. At this time, since the rotor 45 of the motor unit 44 that drives the polygon mirror 42 rotates at a high speed, the bearing 48 of the motor unit 44 has heat and tends to become high temperature. Along with this, heat generated from the motor unit 44 enters the housing 60 and raises the ambient temperature around the polygon mirror 42. Such a continuous temperature rise is an unfavorable situation because it causes a temperature exceeding an appropriate temperature range in use of the polygon motor 41. Accordingly, the scanning optical device 14 further includes two heat radiating components 70 and 80 and a cooling fan 90.

  As shown in FIGS. 4 and 5, the heat dissipating component 70 is a plate-like member constituting the upper surface of the housing 60 and is made of aluminum. In addition, the heat dissipation component 70 is provided for the purpose of cooling the ambient temperature in the housing 60.

  As shown in FIG. 4, the cooling fan 90 is a fan that is provided so as to be aligned horizontally with the housing 60 and blows air from the side S <b> 2 side that is one side of the housing 60. The air blown by the cooling fan 90 passes through the upper surface S3 of the heat radiating component 70 and is discharged to the outside of the image forming apparatus 1. Thereby, the housing 60 is cooled via the heat dissipation component 70. Hereinafter, a flow path from the cooling fan 90 shown in FIG. 5 through the upper surface S3 of the heat dissipation component 70 to the outside of the image forming apparatus 1 is referred to as a flow path A.

  The heat dissipation component 80 is provided mainly for the purpose of cooling the bearing 48 of the motor unit 44. The heat radiation component 80 is a plate-like member made of aluminum, and is provided so as to hang from the bottom surface S1 to the side surface S2 of the housing 60 as shown in FIG.

  A bottom surface portion 82 which is a portion of the heat radiation component 80 on the bottom surface S1 side of the housing 60 is a substantially square plate member, and a central portion of the motor portion 44 protrudes from the bottom surface S1 of the housing 60 as shown in FIG. In contact with the bearing 48. As shown in FIG. 6, two arms extend in the horizontal direction from the bottom surface portion 82, and these are fastened to a casing including the unit case 37 and the housing 60, so that the heat dissipation component 80. Is fixed to the bottom surface S <b> 1 of the housing 60.

  A portion of the heat radiation component 80 on the side surface S2 side of the housing 60 extends from the bottom surface portion 82 toward the flow path A. Further, the portion on the side surface S2 side of the housing 60 in the heat dissipation component 80 can be further divided into two portions.

  One is a cooling unit 86 located in a duct 100 that forms a flow path from the cooling fan 90 to the housing 60 as shown in FIG. As shown in FIG. 6, the cooling unit 86 is a plate-like member having a rectangular shape, and is provided along the side surface S <b> 2 of the housing 60. However, a gap V is provided between the cooling unit 86 and the housing 60 as shown in FIG. The lower and left portions of the gap V are closed by a bead protruding from the side surface S2 of the housing 60. On the other hand, no beads are provided on the upper and right portions. As a result, as shown in FIG. 6, an opening M1 is formed in the upper part of the gap V, and an opening M2 is formed in the right part. Here, the cooling unit 86 is positioned on the lower side in the flow path from the cooling fan 90 to the housing 60, and closes the window W3 provided on the side surface S2 through which the flow path A passes as shown in FIG. Not. That is, the upper part of the flow path from the cooling fan 90 to the housing 60 that is a part of the flow path A is not blocked. As a result, as shown in FIG. 8, the air flow generated by the cooling fan 90 passes through the window W3 and the upper surface S3 of the heat dissipation component 70 from the cooling fan 90 to the outside of the image forming apparatus 1. There is a flow path A that goes to and a flow path B that goes from the cooling fan 90 to the outside of the image forming apparatus 1 via the openings M1 and M2. Further, while the opening M2 faces the right side of the apparatus, the air that has passed from the cooling fan 90 through the upper surface S3 of the heat dissipation component 70 is discharged to the left side of the apparatus as shown in FIG. In addition, the side surface on the cooling fan 90 side in the casing constituting the unit case 37 and the housing 60 is covered with a sheet metal member 93 except for a portion through which air from the cooling fan 90 is passed. Accordingly, the flow path B is formed between the side surface and the sheet metal member 93. Further, a sealing material 95 for preventing leakage of the air blown from the cooling fan 90 is provided at a portion connecting the housing 60 and the duct 100 so as to be sandwiched between the sheet metal member 93 and the duct 100.

  Another part of the heat radiation component 80 on the side surface S2 side of the housing 60 is a connection portion 88 that connects the bottom surface portion 82 and the cooling portion 86 as shown in FIG. The connection portion 88 has a shape similar to an L shape, and is provided along the left half of the side surface S <b> 2 of the housing 60. The lower portion of the connecting portion 88 is connected to the bottom portion 82, and the right portion is connected to the cooling portion 86. In the above description, the heat radiating component 80 is divided into the bottom surface portion 82, the cooling portion 86, and the connection portion 88, but these are made by bending a single aluminum sheet metal.

(effect)
In the scanning optical device 14 and the image forming apparatus 1 including the same according to one embodiment, the heat radiation component 80 for cooling the bearing 48 of the output shaft 46 of the motor unit 44 cools the housing 60 in which the polygon mirror 42 is housed. It is extended toward the air flow path A generated by the cooling fan 90. Accordingly, the cooling fan 90 for cooling the housing 60 in which the polygon mirror 42 is housed is also used as a blowing unit for cooling the heat radiation component 80 for cooling the bearing 48 of the output shaft 46 of the motor unit 44. it can. As a result, a cooling air blowing means is provided for each of the heat radiation component 70 for cooling the housing 60 in which the polygon mirror 44 is housed and the heat radiation component 80 for cooling the bearing 48 of the output shaft 46 of the motor unit 44. And no need to provide a flow path. As a result, in the scanning optical device 14 according to one embodiment and the image forming apparatus 1 including the same, the volume of the heat radiating member and the volume of the cooling channel can be reduced as compared with the conventional scanning optical device. .

  In addition, a gap V is provided between the cooling unit 86 and the housing 60, which are extended portions of the heat dissipation component 80. In addition, an opening M1 is formed in the upper part of the gap V, and an opening M2 is formed in the right part. As a result, the air generated by the cooling fan 90 not only hits the main surface of one side of the cooling unit 86 facing the cooling fan 90 but also enters the gap V from the opening M1 and the other side of the cooling unit 86. The flow path B is formed in contact with the main surface of the image forming apparatus 1 from the opening M2 toward the outside of the image forming apparatus 1. Therefore, the cooling part 86 of the heat radiation component 80 is efficiently cooled because the air from the cooling fan 90 strikes both main surfaces.

  Furthermore, the cooling unit 86 is positioned on the lower side in the flow path from the cooling fan 90 to the housing 60, and is located above the flow path from the cooling fan 90 constituting a part of the flow path A to the housing 60. The part is not blocked. Thereby, compared with the case where there exists an object which interrupts flow path A, the ventilation from cooling fan 90 is directly applied by heat radiating component 70. Therefore, since the cooling unit 86 is arranged so as not to block the flow path A, the heat dissipation component 70 is efficiently cooled, and as a result, the effect of suppressing an increase in the ambient temperature in the housing 60 can be enhanced. .

  Moreover, since the opening M <b> 2 of the gap V faces rightward, most of the air that forms the flow path B out of the air blown from the cooling fan 90 goes to the outside of the image forming apparatus 1 without going toward the heat dissipation component 70. Will be discharged. As a result, the radiating component 70 is hardly blown by the air that has passed through the cooling portion 86, so that the radiating component 70 is further efficiently cooled and further has an effect of suppressing an increase in the ambient temperature in the housing 60. Can be increased. Further, the air blown through the cooling unit 86 does not hit the laser light source 40.

  By the way, the cooling part 86 of the heat radiating component 80 is a part extended from the bottom surface part 82 where the bearing 48 of the motor part 44 is located, so that the heat radiating part 80 is slightly away from the bearing 48 intended for cooling. is there. Therefore, even if the air from the cooling fan 90 is applied to the cooling unit 86 in the same manner as the heat radiating component 70 forming the top surface of the housing 60, the cooling effect equivalent to the effect of cooling the ambient temperature in the housing 60 by the heat radiating component 70 is achieved. Hard to get. However, the cooling part 86 of the heat dissipation component 80 is located in the duct 100 that forms a flow path from the cooling fan 90 to the housing 60. In other words, the cooling unit 86 is positioned upstream of the housing 60 in the flow path of the air generated by the cooling fan 90. As a result, the air just generated by the cooling fan 90 is blown to the cooling unit 86 with priority over the heat radiating component 70. As a result, the cooling part 86 of the heat radiating component 80 is blown with cooler air than the heat radiating component 70, so that the effect of cooling the bearing 48 by the heat radiating component 80 and the ambient temperature in the housing 60 by the heat radiating component 70 are cooled. The balance with the effect to do can be kept moderately.

  A sealing material 95 is provided at a portion connecting the housing 60 and the duct 100 so as to be sandwiched between the sheet metal member 93 and the duct 100. Thereby, the leakage of the ventilation from the cooling fan 90 is prevented, and the effect of cooling the heat dissipation components 70 and 80 is further enhanced.

(Other examples)
The scanning optical device and the image forming apparatus according to the present invention are not limited to the above-described embodiments, and can be variously modified within the scope of the gist thereof. For example, specific dimensions and shapes of each member are arbitrary.

  As described above, the present invention is superior in that the volume of the heat radiation member and the volume of the cooling channel can be reduced as compared with the conventional scanning optical device.

S1 Bottom (the other side)
S3 Top surface (surface on one side)
M1 opening (first opening)
M2 opening (second opening)
V gap 1 image forming device 14 scanning optical device 40 laser light source 41 polygon motor 42 polygon mirror 44 motor unit 46 output shaft (rotating shaft)
60 Housing 70 Heat dissipation component (second heat dissipation component)
80 Heat dissipation component (first heat dissipation component)
90 Cooling fan (fan)
95 Sealing material

Claims (11)

A scanning optical apparatus using a polygon motor including a polygon mirror and a motor unit for driving the polygon mirror,
A blowing means for cooling the housing in which the polygon mirror is housed;
A first heat dissipating component for cooling the motor unit;
With
At least a part of the flow path of the air generated by the air blowing means passes through one surface of the housing that intersects with the extension line of the rotation shaft of the motor unit,
The first heat dissipating part is in contact with the other surface of the housing intersecting with an extension line of the rotating shaft of the motor unit, and is extended from the other surface toward the flow path;
A scanning optical device. A gap is provided between the extended portion of the first heat dissipation component and the housing;
The scanning optical apparatus according to claim 1. A first opening through which the air flows and a second opening through which the air flows out are provided in the gap;
The scanning optical apparatus according to claim 2. The second opening does not face the direction toward the housing;
The scanning optical apparatus according to claim 3. The extended portion of the first heat radiating component is located on the upstream side of the housing in the air flow path generated by the air blowing means,
The scanning optical device according to claim 1, wherein: A flow path from the blowing means toward the housing is provided with a sealing material for preventing leakage of the blowing;
The scanning optical apparatus according to claim 5. The flow path of the air generated by the air blowing means includes a first flow path that passes through one surface of the housing and a second flow path that passes through an extended portion of the first heat dissipation component. Yes,
The second flow path does not pass over a laser light source for irradiating the polygon mirror with laser light;
The scanning optical apparatus according to claim 1, wherein: A second heat dissipating component is attached to the one side surface;
The scanning optical device according to claim 1, wherein: The air blowing means is arranged in a horizontal direction with the housing,
The stretched portion of the first heat dissipating part is located between the air blowing means and the housing;
The scanning optical device according to claim 1, wherein The extended portion of the first heat dissipating component is disposed at a position that does not block the flow path from the air blowing means toward the one surface of the housing;
The scanning optical apparatus according to claim 1, wherein: Comprising the scanning optical device according to any one of claims 1 to 10,
An image forming apparatus.

Images