JPH11249368A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that minimizes the influence of heat on a unit without increasing the size of the unit composed of an image carrier and its peripheral parts. SOLUTION: The image forming device, in which the image carrier 1 is composed as one unit 50 together with its peripheral parts and the unit 50 is attached to a device main body detachably, is equipped with a heat radiating means 52 which radiates heat, generated in the device main body, outside by sucking air in the device main body, a duct part 55 which forms an exhaust-air passage for guiding the air to the radiating means 52, and a shutter 51 which is attached to the unit 50 and protects the image carrier by convering it. The shutter 51 forms the exhaust-air passage together with the duct part 55 and restricts the flow of air toward the duct part 55, thereby preventing the air from flowing into the image-carrier side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus utilizing an electrophotographic process, an electrostatic latent image corresponding to a document image is formed on the surface of a photoreceptor charged to a predetermined polarity in advance. This electrostatic latent image is developed by a developing unit provided at a predetermined position around the photoconductor. That is, the electrostatic latent image is developed and visualized by the charged fine powder toner supplied from the developing unit. The toner image formed on the photoreceptor reaches the transfer unit by rotation of the photoreceptor, and is transferred to a transfer material (recording paper) conveyed to the transfer unit. afterwards,
The toner image transferred to the transfer material is fixed to the transfer material in a fixing unit.

In such an image forming apparatus, a photosensitive member, charging means for charging the surface of the photosensitive member, cleaning means for removing residual toner on the photosensitive member, and developing means for supplying toner are provided. Are configured as an integrated unit, and this unit is detachably attached to the apparatus main body of the image forming apparatus. In such a unit type, the ozone generated due to the discharge of the charging unit is efficiently removed and the heat generated from the fixing unit is efficiently released to minimize the influence of heat on the unit. For this reason, there is a type in which a part of the unit is formed in a duct shape and a wind generation source is arranged at an outlet of the portion formed in the duct shape (Japanese Patent Laid-Open No. 3-10 / 1990).
No. 7953).

[0004]

However, in a unit in which a part of the unit is formed in a duct shape, since the inside of the unit is formed in a duct shape, it is necessary to secure a sufficient air flow in the unit. Requires very large space in the unit. Therefore, there is a disadvantage that the unit becomes large, and as a result, the entire image forming apparatus becomes large.

Further, in a configuration in which the inside of the unit is formed in a duct shape, air flows through gaps between the parts in the unit, so that the efficiency of air flow is extremely low and there is a possibility that turbulence may occur partially. is there.

If the air flow efficiency in the unit is low, the air volume of the exhaust fan (wind generating source) must be increased, and this will generate a loud noise, which may make the user uncomfortable. is there.

The present invention has been made in view of the above circumstances, and has as its object to minimize the influence of heat on the unit without increasing the size of the unit including the image carrier and its peripheral parts. It is an object of the present invention to provide an image forming apparatus which can be reduced to a minimum.

[0008]

According to a first aspect of the present invention, an image carrier is constructed as a single unit together with its peripheral parts, and this unit is attached to and detached from an apparatus main body. In an image forming apparatus that can be mounted, a heat radiating means for sucking air in the apparatus main body and releasing heat generated in the apparatus main body to the outside, and an exhaust passage for guiding the air to the heat radiating means are formed. And a shutter mounted on the unit and covering the image carrier to protect the image carrier. The shutter forms an exhaust passage together with the duct, and regulates a flow of air toward the duct. It is characterized in that lever air is prevented from flowing into the image carrier side.

According to the first aspect of the present invention, it is possible to minimize the influence of heat on the unit without increasing the size of the unit including the image carrier and its peripheral parts.

According to a second aspect of the present invention, in the first aspect of the invention, the shutter is separated from the image carrier by a predetermined distance to form a first position forming an exhaust flow path together with the duct portion; It is characterized by being rotatable between a second position stored in the unit side adjacent to the image carrier.

According to the second aspect of the invention, when the shutter is located at the first position, the heat generated in the apparatus main body is guided to the heat radiating means without contacting the image carrier, and When the shutter is located at the second position, the shutter is housed in the unit side while preventing the thermal effect on the portion of the unit protected by the
The shutter does not interfere when the unit is attached to or detached from the apparatus body.

According to a third aspect of the present invention, in the second aspect, the apparatus main body has a cover which can be opened and closed,
The shutter rotates between a first position and a second position in conjunction with the opening and closing operation of the cover.

According to the third aspect of the invention, the work of attaching and detaching the unit to and from the apparatus main body becomes easy.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a plurality of ribs are formed on the shutter to regulate the flow of air toward the duct. It is characterized by having been done.

According to the fourth aspect of the present invention, the heat generated in the apparatus main body smoothly flows through the ribs to the duct section, and also flows in the duct section toward the heat radiating means, and the heat generated in the apparatus main body. It is discharged outside. That is, the ribs maintain the flow of air toward the duct portion evenly, and realize efficient airflow.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the duct portion is formed by a frame of the apparatus main body.

According to the fifth aspect of the present invention, it is possible to provide an image forming apparatus with high air flow efficiency while minimizing an increase in component costs.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an image forming apparatus (in this embodiment,
1 schematically shows the internal structure of a device main body of a laser printer. As shown in the figure, the apparatus main body has a photosensitive drum (hereinafter simply referred to as a photosensitive member) 1 as an image carrier on which an electrostatic latent image corresponding to image information is formed. Around the photoreceptor 1, a charging charger 2 for charging the surface of the photoreceptor 1 and an electrostatic latent image on the surface of the photoreceptor 1 by irradiating light image data to the photoreceptor 1 after the charging process And a developing device that supplies a toner 5 to the electrostatic latent image formed on the surface of the photoconductor 1 to visualize the electrostatic latent image to form a toner image on the photoconductor 1 6
A transfer unit (transfer bias roller) 7 for transferring the toner image on the photoconductor 1 to a transfer material such as copy paper; and a cleaning unit 3 for cleaning the photoconductor 1 after the transfer process in preparation for the next copy process. And a waste toner storage unit 56 for storing the waste toner removed by the cleaning unit 3.

The laser optical system 4 irradiates the original placed on the contact glass with light and reads the reflected light (image information), and reads the reflected light (image information) based on the image information read by the reading unit. It has a writing section for outputting a laser beam, and a mirror for guiding the laser beam in a predetermined direction.

On the lower side of the apparatus main body, there is provided a paper feeder having a first paper feed cassette 10 detachably attached to the apparatus main body. This paper feeder is fed by the rotation of the paper feed roller 12, the bottom plate 11 that presses the uppermost transfer material (hereinafter referred to as paper) P in the paper feed cassette 10 against the paper feed roller 12, and the paper feed roller 12. And separation pads 13 for separating the sheets of paper P one by one.

A registration roller pair 20 for feeding the paper P fed from the paper feeding device toward the transfer unit 7 at a predetermined timing, and a toner image transferred to the paper P by the transfer unit 7 are provided in the apparatus main body. A fixing device 30 for fixing the sheet P and a sheet discharge tray 40 for receiving the sheet P on which the fixing process has been performed are provided.

The fixing device 30 includes a fixing roller 32 having a built-in heater 31 and a pressure roller 33 pressed against the fixing roller 32. These rollers 32, 3
The sheet P is drawn into the nip portion between the three and the toner image on the sheet P is fixed. On the downstream side of the fixing device 30 in the sheet discharging direction, a sheet discharging roller pair 34 for sending out the sheet P on which the fixing process has been completed toward the sheet discharging tray 40 is provided.

In such a configuration, first, the paper feed rollers 12
Is rotated in the direction of the arrow in the drawing, and the uppermost sheet P is fed out of the sheet cassette 10 while being separated one by one by the separation pad 13. The fed sheet P is transferred to the transfer unit 7 by the registration roller pair 20 at a predetermined timing.
Transported to During this time, the photoreceptor 1 is driven to rotate counterclockwise in the figure, and the surface is uniformly charged by the charging charger 2, and receives a laser beam from the laser optical system 4 to form an electrostatic latent image on the surface. Is formed. The electrostatic latent image is visualized by the toner 5 supplied from the developing device 6, and the visualized toner image is transferred to the upper surface of the sheet P conveyed to the photoconductor 1 by the transfer unit 7. Then, the paper P after the image transfer is conveyed to the fixing device 30, where the transferred image is fixed. The paper P sent from the fixing device 30 is discharged onto the paper discharge tray 40 by the paper discharge roller pair 34 in a face-down state with its recording surface facing down. In addition, the photoconductor 1 after image transfer
The remaining toner is removed by the cleaning unit 3.

In the image forming apparatus according to the present embodiment, the photosensitive member 1, the charging charger 2, the cleaning unit 3, the developing unit 6, and the waste toner storage unit 56 are formed as an integral cartridge (unit) 50. Have been. The cartridge 50 is detachably attached to the apparatus main body, and as shown in FIG. 4, an openable / closable front cover 60 (in this embodiment, provided on the right side of the apparatus main body in the figure).
(The front side of the apparatus main body is on the right side in the figure).

The front cover 60 is configured to be rotatable about a support shaft 60a supported by the apparatus main body for jam clearance and replacement / maintenance of the cartridge 50. Further, a second sheet cassette 66 is provided in the front cover 60. This second paper cassette 66
The paper feed roller 67, a bottom plate 65 for pressing the uppermost sheet P in the paper feed cassette 65 against the paper feed roller 67, and a separation pad for separating the paper P fed by the rotation of the paper feed roller 67 one by one The sheet P can be conveyed to the registration rollers 20 as in the case of the first sheet cassette 10.

As shown in detail in FIG.
A fan motor 52 that sucks air in the apparatus main body and discharges heat generated in the apparatus main body to the outside is attached. The fan motor 52 is provided with a duct 55 connected to the outside of the apparatus main body through the fan motor 52. The cartridge 50 is provided with a photoconductor protection shutter 51 for preventing high-temperature air from flowing toward the photoconductor 1. The protective shutter 51 is connected to the cartridge 50.
Is rotatably held by a support shaft 51a supported by
In the illustrated set state, an exhaust passage (duct space) is formed together with the duct portion 55 connected to the fan motor 52.

As shown in FIG. 5, the upper surface of the protective shutter 51 which forms an exhaust passage together with the duct portion 55 connected to the fan motor 52 extends along the width direction of the photosensitive member 1 (total width of the photosensitive member 1). ), A plurality of partition ribs a to e are provided. These ribs a to e form the duct 5 without causing turbulent flow of high-temperature air from the fixing device 30 side.
5 so as to be smoothly guided toward 5.

The protective shutter 51 is separated from the photosensitive member 1 to form a discharge passage together with the duct portion 55 (the position shown in FIG. 2).
Between the retracted position (the position shown in FIG. 3) and the support shaft 51.
It is rotated around a. In particular, in the present embodiment, the protection shutter 51 is rotated in conjunction with the opening and closing operation of the front cover 60. That is, as shown in FIG.
When the front cover 60 is opened, the protective shutter 51 is turned to the retreat position around the support shaft 51a via a drive mechanism such as a link mechanism (not shown). In this state, the photosensitive member 1
It is possible to take out the protective shutter 51 positioned so as to cover from the apparatus main body together with the cartridge 50 (see FIG. 4). As shown in FIG. 2, when the front cover 60 is closed, the protective shutter 51 is rotated to the set position about the support shaft 51a via a drive mechanism such as a link mechanism (not shown). In this state, the protection shutter 5
Numeral 1 is separated from the photoreceptor 1 and forms, together with the duct portion 55, an exhaust passage for discharging high-temperature air on the side of the fixing device 30 toward the fan motor 52.

As described above, in the image forming apparatus of the present embodiment, the photosensitive member protection shutter 51 for preventing high-temperature air from flowing toward the photosensitive member 1 is mounted on the cartridge 50, and the protection shutter 51 Is configured to be rotated between a set position where an exhaust passage is formed together with the duct portion 55 on the side of the fan motor 52 and a retracted position where the photosensitive member 1 is covered.

Accordingly, when the protective shutter 51 is located at the set position, the high-temperature air generated from the fixing device 30 is guided to the fan motor 52 without coming into contact with the photoreceptor 1 as shown by an arrow in FIG. When the protective shutter 51 is located at the retracted position, the protective shutter 51 is compactly stored in the cartridge 50 side, while the thermal effect on the cartridge portion below the shutter 51, in particular, the discharged toner storing portion 56 is prevented. The protective shutter 51 does not interfere when the cartridge 50 is attached to or detached from the apparatus main body.

Further, in the image forming apparatus of the present embodiment, the protective shutter 5 which forms an exhaust passage together with the duct 55
A plurality of partition ribs a to e are provided on the upper surface of one.
Therefore, when the protection shutter 51 is located at the set position, the high-temperature air from the fixing device 30 flows smoothly to the duct 55 through the partition ribs a to e on the protection shutter 51 and The air flows into the fan motor 52 and is discharged to the outside of the apparatus main body. That is, the partition ribs a to e maintain the flow of air toward the duct 55 evenly, and realize an efficient air flow. Such an efficient and uniform air flow makes it possible to suppress the air volume of the fan motor 52 and reduce the noise level.

As described above, in the present embodiment, the inside of the cartridge 50 is not formed in a duct shape, but only by providing the rotatable protective shutter 51 on the cartridge 50 without increasing the size of the cartridge 50. The effect of heat on the cartridge 50 can be minimized. That is, while effectively utilizing the existing space between the cartridge 50 and the apparatus main body, a sufficient and efficient air flow can be secured, and the cartridge 50 can be made compact.

In the image forming apparatus of this embodiment, the protective shutter 51 is automatically rotated between the set position and the retracted position in conjunction with the opening and closing operation of the front cover 60. Therefore, the work of attaching and detaching the cartridge 50 to and from the apparatus main body becomes easy.

In the above-described embodiment, the duct 55 as a separate member (dedicated component) is connected to the fan motor 52. However, the duct 55 may be formed by an existing frame of the apparatus body. That is, the duct portion 55 may be formed by the frame portion 53 of the apparatus main body that extends to the fan motor 52 and the cover portion 54 that forms a part of the paper discharge tray 40 and faces the frame portion 53. As described above, if the duct portion 55 is configured using the shape of the existing components of the apparatus main body, it is possible to form the exhaust passage (duct space) without newly providing a dedicated component, thereby reducing component costs. It is possible to provide an image forming apparatus with good airflow efficiency while minimizing the rise.

[0036]

According to the first aspect of the present invention, the effect of heat on the unit can be minimized without increasing the size of the unit including the image carrier and its peripheral parts.

According to the second aspect of the invention, when the shutter is located at the first position, heat generated in the apparatus main body is guided to the heat radiating means without contacting the image carrier.
The effect of heat on the part of the unit protected by the shutter is prevented, and when the shutter is located at the second position, the shutter is housed in the unit side so that the shutter does not interfere when the unit is attached to or detached from the apparatus main body. .

According to the third aspect of the present invention, the unit can be easily attached to and detached from the apparatus main body.

According to the fourth aspect of the present invention, the heat generated in the apparatus main body smoothly flows through the ribs to the duct section, and also flows in the duct section toward the heat radiating means, and the heat generated outside the apparatus main body. Is discharged to That is, the ribs maintain the flow of air toward the duct portion evenly, and realize efficient airflow.

According to the fifth aspect of the present invention, it is possible to provide an image forming apparatus with high air flow efficiency while minimizing an increase in component costs.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a state in which a front cover is closed and a shutter is located at a set position.

FIG. 3 is a diagram illustrating a state in which a front cover is opened and a shutter is located at a retracted position.

FIG. 4 is a view showing a state in which a shutter is taken out of the apparatus main body together with a unit through an opened front cover.

FIG. 5 is a perspective view of a shutter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor (image carrier) 50 Cartridge (unit) 51 Shutter 52 Fan motor (radiator) 55 Duct part 60 Front cover a, b, c, d, e Partition rib

Claims (5)

[Claims] 1. An image forming apparatus in which an image carrier is configured as one unit together with its peripheral parts, and this unit is detachably mounted on the apparatus main body. Heat radiating means for radiating heat generated inside to the outside, a duct portion forming an exhaust flow path for guiding air to the heat radiating means, and a shutter mounted on the unit and covering and protecting the image carrier. Image forming, wherein the shutter forms an exhaust passage together with the duct portion, and regulates the flow of air toward the duct portion to prevent the air from flowing into the image carrier side. apparatus. 2. A first shutter which forms an exhaust passage together with a duct at a predetermined distance from the image bearing member.
The image forming apparatus according to claim 1, wherein the image forming apparatus is rotatable between a position (1) and a second position stored in the unit side adjacent to the image carrier. 3. The apparatus main body has an openable / closable cover, and the shutter rotates between a first position and a second position in conjunction with the opening / closing operation of the cover. Item 3. The image forming apparatus according to Item 2. 4. The image according to claim 1, wherein the shutter has a plurality of ribs for restricting a flow of air toward the duct. Forming equipment. 5. The image forming apparatus according to claim 1, wherein the duct portion is formed by a frame of the apparatus main body.