JPH05346694A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To suppress the temperature rise of a cleaner with the heat of a fixing unit, without adopting a constitution against a request for miniaturization. CONSTITUTION:A process cartridge 30 provided with the cleaner 16 is attached to an upper main body 10b, and the fixing unit 23 is provided with a lower main body 10a. A shutter member 40 is provided on the process cartridge 30. The shutter member 40 is supported so as to freely move to a shield position for covering an aperture 31a and a retreating position between the cleaner 16 and the fixing unit 23, by freely turnable first and second arms 41 and 42. Then, the engaging projecting part 41a of the first arm 41, is engaged with the guiding rib 45 of the lower main body 10a, in a state where the upper main body 10b is closed, and the shutter member 40 is held at the retreating position so as to shield between the cleaner 16 and the fixing unit 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention records on a sheet by an electrophotographic system (a system for transferring an image formed on a photoconductor to a sheet for recording) such as a printer, a copying machine, and a facsimile using a laser. The present invention relates to an electrophotographic device.

[0002]

2. Description of the Related Art Conventionally, for example, in a laser printer, an electrophotographic process device such as a charging device, a developing device, a transfer device, and a cleaning device is arranged around a photosensitive member, and a toner image is formed on the photosensitive member by the electrophotographic process device. And the toner image is transferred to the sheet. After the transfer, the toner image is fixed by applying heat with a fixing device, while the residual toner on the photoconductor is removed with a cleaning device and collected in the waste toner tank chamber.

By the way, the size of this laser printer has recently been reduced, and, for example, the fixing device and each electrophotographic process device are arranged close to each other. However, when the electrophotographic process device is arranged close to the fixing device, various problems occur due to the influence of heat received from the fixing device during image fixing. In particular, in the cleaning device adjacent to the fixing device, problems such as the collected toner in the waste toner tank chamber being solidified by heat have occurred.

Therefore, conventionally, for example, the cleaning device and the fixing device are arranged far apart from each other, or a large fan is separately installed to suppress the temperature rise of the cleaning device.

[0005]

However, if the cleaning device and the fixing device are largely separated from each other or a large fan is installed in this way, there is a problem that the request for downsizing of the apparatus is violated.

Therefore, an object of the present invention is to prevent the temperature of the cleaning device from rising due to the heat of the fixing device in the electrophotographic device as described above, without making the structure contrary to the demand for downsizing of the device. Especially.

[0007]

Therefore, the present invention provides
For example, as in the following illustrated embodiment, at least the cleaning device 16 is integrated with the photoconductor 12 to form a process cartridge 30, and the process cartridge 30 is attached to the upper main body 10b of the apparatus main body 10 while the lower side of the apparatus main body 10 is attached. In the electrophotographic apparatus including the fixing device 23 in the main body 10a, the process cartridge 30 has a shielding position covering the opening 31a and the cleaning device 16.
A shutter member 40 is provided movably between the retracted position and the fixing device 23, and the shutter member 40 is moved to the shield position or the retracted position in conjunction with the opening / closing operation of the upper body 10b. It is characterized by

According to a second aspect of the present invention, for example, as in the following illustrated embodiment, in the electrophotographic apparatus according to the first aspect, a heat insulating material 50 is superposed on the shutter member 40. ..

According to a third aspect of the present invention, a heat reflecting material 51 is superposed on the fixing device 23 side of the shutter member 40 in the electrophotographic apparatus of the first aspect, for example, as shown in the following illustrated embodiments. It is characterized by

According to a fourth aspect of the present invention, the shutter member 40 has a duct shape in the electrophotographic apparatus according to the first aspect, for example, as shown in the following embodiments.

[0011]

When the upper body 10b is opened, the shutter member 40 is moved to the closed position to cover the opening 31a, and when the upper body 10b is closed, the shutter member 40 is moved to the retracted position to clean the cleaning device 16. And between the fixing device 23 is blocked.

According to the second and third aspects, when the shutter member 40 is in the retracted position, heat is blocked.

According to the fourth aspect of the present invention, when the shutter member 40 is in the retracted position, the air inside the apparatus body 10 flows through the duct-shaped shutter member 40.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 7 is a schematic view of the entire internal structure of a laser printer according to an embodiment of the present invention.

Reference numeral 10 in the figure denotes the apparatus main body. The apparatus main body 10 is composed of a lower main body 10a and an upper main body 10b, and the upper main body 10b is pivoted on the lower main body 10a by a fulcrum 1
It can be opened and closed centering around 1. In the device body 10,
A belt-shaped photoconductor 12 is provided in the approximate center. Around the photoconductor 12, a charging device 13, a developing device 14, a transfer device 15, and a cleaning device 1 are arranged in this order in a driving direction indicated by an arrow in the figure.
Place 6 An optical writing device 17 is arranged above the charging device 13 and the cleaning device 16, and a paper feeding cassette 18 accommodating the sheet S is arranged below the transfer device 15. Then, in this device body 10, the lower body 10a is
At least the developing device 14, the transfer device 15, and the fixing device 23 are attached, and at least the photoconductor 12, the charging device 13, the cleaning device 16, and the optical writing device 17 are attached to the upper main body 10b.

Then, the sheet feeding roller 20 is rotated to feed the sheet S from the sheet feeding cassette 18 in the direction of the arrow A in the figure, and the registration roller pair 21 conveys the sheet S to the lower side of the photoconductor 12 at a timing. The photoconductor 12 is driven in the clockwise direction indicated by the arrow, and at that time, the surface of the photoconductor 12 is uniformly charged by the charger 13, and the laser beam from the optical writing device 17 is irradiated to the photoconductor 12 to form an electrostatic latent image. To form. This latent image is developed by the developing device 1.
When passing through the 4th position, a visible image is formed by the toner. Then, the visible image is transferred by the transfer device 15 onto the upper surface of the sheet S conveyed to the lower side of the photoconductor 12. And
The sheet S after the image transfer is guided by the conveyance guide 22 and conveyed to the fixing device 23, and the fixing device 23 fixes the transferred image. Then, the sheet S exiting the fixing device 23 is further conveyed by the sheet ejection roller 24 and ejected in the direction of arrow B or C in the figure.

On the other hand, after the image transfer, the photoconductor 12 is cleaned by the cleaning device 16 to remove the residual toner, and then the static eliminator 2 is used.
Remove electricity at 5.

By the way, in the illustrated laser printer, as shown in FIG.
As shown in, the cleaning device 16 is integrated with the photoconductor 12 to form the process cartridge 30, and the process cartridge 30 is replaceably attached to the upper main body 10b. In the process cartridge 30, the photoconductor 12 is arranged on the right side of the case 31, and the cleaning device 16 is arranged on the left side of the photoconductor 12. The case 31 is located at a position facing the transfer roller 15 and the developing roller 14a of the developing device 14, and has a transfer opening 31a and a developing opening 31b, respectively.
To provide. The cleaning device 16 is constructed by holding a cleaning blade 32 in a case 31 by a holder 33 and pressing the tip of the blade 32 against the photoconductor 12. Also,
A waste toner tank chamber 34 is formed on the fixing device 23 side, and a recovery blade 35 and a recovery blade are provided in the waste toner tank chamber 34.
The door 36 is provided.

Further, the process cartridge 30 is provided with a plate-like shutter member 40 on the outer surface of the case 31 between the cleaning device 16 and the fixing device 23. The shutter member 40 has a V-shaped cross section in conformity with the outer surface of the case 31, and has one end both ends thereof connected to the tip of the first arm 41 and both ends opposite both ends thereof to which the second arm 42 is connected. Each first arm 41
Are attached to the support shafts 43 on the outer surfaces of both sides of the case 31, respectively.
The center of each second arm 42 is also rotatable about the support shaft 44 on the outer surface of both side portions of the case 31. Each of the first arms 41 is provided with an outwardly projecting engaging projection 41a in the middle thereof. Then, when the upper main body 10b is in the closed state in the drawing, the engagement convex portion 41a is hooked on the guide rib 45 provided on the lower main body 10b to hold the shutter member 40 at the retracted position between the cleaning device 16 and the fixing device 23. The guide rib 45 is provided with a guide portion 45a that engages with the engaging convex portion 41a to guide the shutter member 40 to the retracted position when closing the upper body 10b. The second arm 42 has a toggle spring 46 at each base end.
Attach. The toggle spring 46 has one end hooked on the second arm 42 and the other end hooked on the outward projection 31c provided on the outer surface of the side portion of the case 31. Then, the toggle spring 46 constantly urges the first and second arms 41 and 42 to rotate counterclockwise about the support shafts 43 and 44, respectively, so that the shutter member 40 covers the transfer opening 31a. Gives a movement habit to the shield position.

In the illustrated laser printer, as shown in FIG. 1, after the transfer of the toner image, the sheet S is guided by the conveyance guide 22 and conveyed to the fixing device 23, and is added to the fixing roller 23a of the fixing device 23. Heat and pressure are applied between the pressure rollers 23b to fix the toner image. On the other hand, the cleaning blade 32 scrapes off the residual toner t on the photoconductor 12 for cleaning, and the scraped toner t is sent by the recovery blade 35 to be collected in the waste toner tank chamber 34. In addition, the tip of the recovery blade 36 is pressed against the recovery blade 35 so that the toner t
Are prevented from adhering to the recovery blade 35.

When the image is fixed, the shutter member 40 located at the retracted position prevents the temperature of the cleaning device 16 from rising due to the heat generated from the fixing device 23.

Further, in the illustrated laser printer, the upper main body 10b is used at the time of maintenance such as jam clearance and photoconductor replacement.
Open. Then, the process cartridge 30 ascends together with the upper main body 10b, and the engaging convex portion 41a moves into the guide rib
5, the first and second arms 41 and 42 are rotated counterclockwise by the biasing force of the toggle spring 46, and the shutter member 40 is moved to the blocking position as shown in FIG.
Then, the shutter member 40 covers the transfer opening 31a to protect the photoconductor 12.

After the maintenance is completed, the upper body 10b is closed. Then, the process cartridge 30 descends together with the upper main body 10b, the engaging convex portion 41a of the first arm 41 is engaged with the guide portion 45a, and the guide portion 45a guides the first and second arms 41, 42. Toggle spring 4
Rotate clockwise against 6. Then, as shown in FIG. 1, the shutter member 40 is moved to the original retracted position to open the transfer opening 31a.

By the way, in the present invention, as shown in FIG. 3, for example, a heat insulating material 50 such as felt may be laminated and attached to the inner surface of the shutter member 40 on the cleaning device 16 side. Also, for example, in FIG.
As shown in, the heat reflecting plate 51 may be attached to the outer surface of the shutter member 40 on the fixing device 23 side in a superposed manner.

Further, according to the present invention, as shown in FIG. 5, for example, both side edges of the shutter member 40 in the lengthwise direction are bent to form a rising portion 40a to form a duct shape, and the shutter member 40 is attached to the process cartridge 30. It may be attached. And in this illustrated embodiment,
When in the retracted position, the shutter member 40 has a duct shape as shown in FIG. 6, and the shutter member 40 and the outer surface of the cleaning device 16 form an air passage 55.

In the illustrated embodiment, at the time of fixing an image, an exhaust fan 60 provided on the fixing device 23 creates a flow of air in the apparatus main body 10. Then, as indicated by an arrow A in FIG. 6, the air flows in through an inlet 55 a separated from the fixing device 23 and flows out through an outlet 55 b through the air passage 55. Therefore, the circulation of the air prevents the temperature of the cleaning device 16 from rising due to the heat of the fixing device 23.

[0027]

Therefore, according to the present invention, when the electrophotographic apparatus having the upper main body closed is used, the shutter member is arranged between the cleaning device and the fixing device, which violates the demand for downsizing of the device. Without the configuration, it is possible to prevent the temperature of the cleaning device from rising due to the heat of the fixing device.

According to the second aspect of the present invention, the temperature rise of the cleaning device can be suppressed more effectively by the heat insulating material.

According to the third aspect of the present invention, the temperature increase of the cleaning device can be suppressed more effectively by the heat reflecting material.

According to the fourth aspect, the temperature rise of the cleaning device can be suppressed more effectively by the air flow in the duct-shaped shutter member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of a laser printer that is an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of the laser printer when the upper main body is opened.

FIG. 3 is a side view of a shutter member in which heat insulating materials are superposed.

FIG. 4 is a side view of a shutter member in which heat reflecting plates are superposed.

FIG. 5 is a perspective view of a duct-shaped shutter member.

FIG. 6 is an arrangement configuration diagram showing a process cartridge to which the shutter member is attached, a fixing device, and an exhaust fan.

FIG. 7 is an overall schematic configuration diagram showing an internal mechanism of a laser printer which is an embodiment of the present invention.

[Explanation of symbols]

 10 Device Main Body 10a Lower Main Body 10b Upper Main Body 12 Photoconductor 16 Cleaning Device 23 Fixing Device 30 Process Cartridge 31a Opening 40 Shutter Member 50 Heat Insulating Material 51 Heat Reflecting Plate

Claims (4)

[Claims] 1. An electrophotographic apparatus comprising a photoconductor and at least a cleaning device integrated with each other to form a process cartridge, and the process cartridge is attached to an upper main body of the apparatus main body while a fixing unit is provided to a lower main body of the apparatus main body. The process cartridge is provided with a shutter member movably between a shielded position covering the opening and a retracted position located between the cleaning device and the fixing device, and the shutter member is interlocked with the opening / closing operation of the upper main body. And an electrophotographic apparatus which is moved to the shielding position or the retracted position. 2. The electrophotographic apparatus according to claim 1, wherein a heat insulating material is superposed on the shutter member. 3. The electrophotographic apparatus according to claim 1, wherein a heat reflecting material is superposed on the fixing member side of the shutter member. 4. The electrophotographic apparatus according to claim 1, wherein the shutter member has a duct shape.