JPH06148965A - Image forming device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a protecting cover provided on a developing process unit, to reduce the cost of a device and to detect whether the unit is used or not by the protecting cover. CONSTITUTION:The developing process unit 13 obtained by arranging and integrating a photosensitive drum 7, an electrostatic charger 8, a developing device 9, a toner cleaner 10, a discharge toner box 11, a destaticizing lamp 12 or the like is provided so as to be freely loaded and unloaded in/from the device main body. The exposed part of a photosensitive body in the unit 13 is protected by the sheet-like protecting cover 22 and the cover 22 is carried and ejected by driving a carrying mechanism when the unit 13 is loaded in the device main body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus applied to a laser printer, a copying machine or the like.

[0002]

2. Description of the Related Art In this type of image forming apparatus, a charging mechanism, an exposure mechanism, a developing mechanism, a transfer mechanism and the like are arranged around a photosensitive drum, and the surface of the photosensitive drum is charged by the charging mechanism and then the exposure mechanism is used. An exposure is performed to form an electrostatic latent image on the surface of the photosensitive drum, a developing mechanism causes toner to adhere to the electrostatic latent image, and the toner image is transferred to a transfer paper by a transfer mechanism. The transfer paper on which the toner image has been transferred is then thermally fixed by the fixing device and discharged to the outside.

In such an image forming apparatus, maintenance such as replacement of the photoconductor, disposal of waste toner, replenishment of developer, cleaning of the charging mechanism, etc. is required depending on the period of use. Although the maintenance work has been relatively troublesome, a compact personal computer and a laser printer have been developed in recent years, and it is required to simplify the maintenance work as much as possible.

From the above, a unit in which a series of developing processes such as a photoconductor, a charging mechanism and a developing mechanism are unitized has been developed. In such a unit, the portion of the photoconductor facing the transfer mechanism of the apparatus main body is exposed. Therefore, a protective cover is required to protect the exposed portion from ultraviolet ray irradiation and external damage.

From the above, Japanese Patent Laid-Open No. 57-2000
In No. 52 publication, a protective cover is integrally attached to the unit,
When the unit is loaded in the apparatus main body, the protective cover opens and the portion of the photoconductor facing the transfer mechanism is exposed, and when the unit is taken out of the apparatus main body, the protective cover closes.

[0006]

However, there is a problem in that the structure in which the unit and the protective cover are integrated is complicated in structure. In addition, since the protective cover is closed when the unit is taken out from the device body, it is not possible to distinguish whether the unit is in use or not in use when the unit is taken out halfway and reloaded. There was a problem that a separate mechanism had to be provided in order to inform.

Therefore, according to the present invention, in a unit provided with a protective cover, the structure is simple and the cost can be reduced, and it is possible to easily distinguish between a unit in use and an unused unit. Is to provide.

[0008]

The invention according to claim 1 is
Unitize with at least a part of the photoconductor exposed
In an image forming apparatus in which this unit is detachably provided in an apparatus main body having a sheet conveyance mechanism, the unit is provided with a sheet-like protective cover for protecting the exposed portion of the photoconductor, and the apparatus main body has a conveyance mechanism when the unit is attached. A control means for driving the protective cover to convey and discharge the protective cover is provided.

According to a second aspect of the present invention, the unit is provided with a sheet-like protective cover for protecting the exposed portion of the photosensitive member, and the apparatus main body drives the transport mechanism when the unit is mounted to transport and discharge the protective cover. A sensor for detecting the presence or absence of the protective cover conveyed by the control means is provided, and the sensor output determines whether the unit is used or not.

According to a third aspect of the invention, the unit is provided with a sheet-like protective cover that protects the exposed portion of the photoconductor and has a cleaning function for the transport mechanism and the fixing device.
The apparatus main body is provided with a control unit that drives the transport mechanism when the unit is mounted and transports and discharges the protective cover through the fixing device.

According to a fourth aspect of the present invention, the unit is provided with a sheet-like protective cover for protecting the exposed portion of the photoconductor and information on the number of times the unit is used in the apparatus body, and the apparatus body is provided with a transport mechanism for mounting the unit. A control means for driving and discharging the protective cover and an information reading means for reading the unit use number information from the protective cover conveyed by the control means are provided.

[0012]

In the present invention having such a structure, when an unused unit is mounted on the apparatus main body, the transport mechanism is driven to peel off the protective cover from the unit and transport and discharge it. Therefore, the unit once in use does not have a protective cover.

Further, in the present invention, when an unused unit is mounted on the apparatus main body, the transport mechanism is driven to peel off the protective cover from the unit and transport and discharge it. At this time, the sensor detects the protective cover conveyed and determines that the unit is an unused unit. Further, when the unit in use is attached to the apparatus main body, the sensor does not detect the protective cover because there is no protective cover. This determines that the unit is the unit in use.

Further, in the present invention, when an unused unit is mounted on the apparatus main body, the transport mechanism is driven to peel off the protective cover from the unit and transport and discharge it. At this time, the conveyance mechanism and the fixing device are cleaned by the cleaning function provided in the protective cover.

Further, in the present invention, when an unused unit is mounted on the apparatus main body, the transport mechanism is driven to peel off the protective cover from the unit and transport and discharge it. At this time, the unit use count information is read from the protective cover conveyed. That is, it is possible to know how many times the unit is a unit.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the invention is applied to a laser printer.

FIG. 1 shows the overall structure. A sheet conveying path 6 extending from a sheet feeding cassette 2 in a housing 1 of the apparatus main body to a sheet discharging section 5 above the housing via a transfer section 3 and a fixing device 4. Is formed. A photosensitive drum 7 is provided in the central portion of the housing 1, and a charger 8, a developing device 9, a toner cleaner 10, a waste toner box 11, a charge eliminating lamp 12 and the like are sequentially arranged around the photosensitive drum 7 to integrally form a unit. The developing process unit 13 is detachably incorporated into the apparatus main body.

A laser scanner unit 14 is arranged above the unit 13, and a laser beam from the laser scanner unit 14 is applied to the surface of the photosensitive drum located between the charging charger 8 and the developing device 9 for exposure. It is like this. The transfer charger 15 is attached to the transfer unit 3.
Are arranged.

The developing process unit 13 charges the photosensitive drum 7 with the charger 8 and then exposes it with a laser beam from the laser scanner unit 14 to form an electrostatic latent image. The electrostatic latent image is developed by the developing unit 9 A toner image is formed by adhering the toner from the above, and the toner image is transferred to the transfer paper 16 by the transfer unit 3. Then, the residual toner remaining on the surface of the photosensitive drum 7 due to the transfer is cleaned by the toner cleaner 10, and the surface of the photosensitive drum 7 is discharged by the discharging lamp 12.

The transfer paper 16 is housed in the paper feed cassette 2, and is sent out from the paper feed cassette 2 to the paper transport path 6 by the paper feed roller 17 at a predetermined timing, and in the paper transport path 6 by the paper feed roller 18. It is supplied to the transfer unit 3. Then, after the toner image is transferred from the photosensitive drum 7 by the operation of the transfer charger 15 in the transfer unit 3, it is heat-fixed by the fixing device 4 and is sent out to the paper discharge unit 5 through the paper conveyance path 6. It has become.

A sensor 19 for detecting a conveyed sheet is arranged in the sheet conveying path 6 between the transfer section 3 and the fixing device 4.

A power supply 20 and a circuit board 21 incorporating control circuit components are arranged on the bottom of the housing 1.

As shown in FIG. 2, the developing process unit 13 is provided with a sheet-like protective cover 22 for protecting the exposed portion of the photosensitive drum 7, that is, the portion facing the transfer portion 3 when not in use. The protective cover 22 is formed of a flexible thin film such as paper or a plastic film, and plays a role of protecting the exposed portion of the photosensitive drum 7 from ultraviolet irradiation, dust, dust, and other damages caused by the objective. In addition,
The developing device 9 includes a toner storage box 23 and a developing roller 2.
4, the blade 25 and the like.

As shown in FIG. 3, a hole 22a and a black solid portion 22b that easily attracts toner are formed in the protective cover 22 provided in the developing process unit 13 which is mounted for the second time or later with respect to the main body of the apparatus. It has become. The solid black portion 22a is formed by solid black printing in advance.

FIG. 4 is a block diagram showing the control circuit.
Is a CPU (central processing unit) that constitutes the control unit main body, 32
Is a ROM (read only memory) storing program data for the CPU 31 to control each section,
A reference numeral 33 designates a buffer memory for storing print data received from the host, a page memory for storing data developed in a dot pattern, and a RAM forming a print number counter.
(Random access memory), 34 is an interface for communicating with the host, and 35 is an I / O port.
The CPU 31, ROM 32, RAM 33, interface 34 and I / O port 35 are electrically connected by a bus line 36.

The photosensitive drum 7 is connected to the I / O port 35.
And a driver 38 of a motor 37 for driving the transport mechanism of the sheet transport path 6, the laser scanner unit 14, a high voltage power source 39 for supplying a high voltage to the charger 8 and the transfer charger 15, the developing device 9, the sensor 19 and the like. A sensor circuit 40 for fetching signals from the device, an operation panel 41 provided with various keys and a display, and the like are connected to each other.

A program is set so that the CPU 31 performs the processing shown in FIG. 5 when the developing process unit 13 is mounted.

That is, when the unit 13 is mounted, the motor 37 is driven to drive the transport mechanism of the paper transport path 6. Then, it is checked whether or not there is a detection output of the protective cover 22 by the sensor 19 from the sensor circuit 40. If there is a detection output, it is determined that the mounted unit is an unused unit, and if there is no detection output even after a certain period of time, it is determined that the mounted unit is already in use. When the unused unit is determined, the print number counter provided in the RAM 33 is reset.

Then, it is checked whether or not there is a hole detection output of the protective cover 22 by the sensor 19 from the sensor circuit 40. If the hole is not detected by the sensor 19, the protective cover 22 is waited for being discharged to the paper discharge section 5, and when it is discharged, this processing is ended.

When the hole is detected by the sensor 19, it is determined that the unit mounted this time is the second time or later in the apparatus, and the conveyance of the protective cover 22 is temporarily stopped before the fixing device 4. That is, the drive of the motor 37 is temporarily stopped. Then, the fixing device 4 is warmed up and waits until the temperature of the fixing roller 4a rises sufficiently. When the temperature of the fixing roller 4a of the fixing device 4 rises sufficiently, the motor 37 is driven again to re-drive the transport mechanism of the paper transport path 6. Then, the process waits until the protective cover 22 is discharged to the paper discharge unit 5, and when discharged, this processing ends.

In the embodiment having such a structure, when the unused developing process unit 13 is attached to the apparatus main body, the motor 37 is driven and the transport mechanism of the paper transport path 6 is driven. Then, the protective cover 22 is peeled off from the developing process unit 13 by driving the transport mechanism, and the sheet is transported through the sheet transport path 6. At this time, if the developing process unit 13 is attached to the main body of the apparatus for the first time, the hole 22a is not formed in the protective cover 22. At this time, therefore, the protective cover 22 remains as it is through the sheet conveying path 6 and the sheet discharging section. It is discharged to 5.

When the protective cover 22 is discharged, the sensor 19 detects the protective cover 22. As a result, the CPU 31 of the apparatus main body knows that the unused developing process unit 13 has been mounted, and resets the print number counter. In this way, the printed sheet counter can count the number of printed sheets from the beginning with respect to the unused developing process unit 13, and thus the life of the developing process unit 13 can be grasped from this count value.

If the developing process unit 13 is taken out of the apparatus body and attached again during the life of the developing process unit 13, the developing process unit 13 does not already have the protective cover 22 at this time. The sensor 19 does not detect the protective cover. Therefore, at this time, it is determined that the developing process unit 13 is the unit in use, and the print number counter is not reset.

When the unused developing process unit 13 for the second time and thereafter is mounted on the main body of the apparatus, the protective cover 22 has a hole 22a and a solid black portion 22b at this time. Therefore, the sensor 19 detects the protective cover 22 and further detects the hole 22a.

As a result, the CPU 31 of the apparatus main body knows that the unused developing process unit 13 has been mounted and that it has been mounted for the second time and thereafter, resets the print number counter and conveys the protective cover 22. 6 is temporarily stopped before the fixing device 4 as shown in FIG.

In this state, it waits until the temperature of the fixing roller 4a of the fixing device 4 rises sufficiently. When the temperature of the fixing roller 4a rises sufficiently, the motor 37 is driven again to restart the conveyance of the protective cover 22.

When the protective cover 22 is conveyed, the black solid portion 22b cleans the toner adhering to the conveying mechanism of the sheet conveying path 6 and also the toner adhering to the fixing roller 4a of the fixing device 4. It Moreover, since the temperature of the fixing roller 4a is sufficiently high, the toner attached to the fixing roller 4a can be efficiently cleaned.

The protective cover 22 is in the form of a sheet and is attached to the exposed portion of the photosensitive drum.
The configuration is extremely simple and can be realized at low cost.

In the above embodiment, one hole 22a is provided in the protective cover 22 to notify the second and subsequent mounting of the unit, but the mounting frequency can be more accurately adjusted by changing the size and number of the holes. Alternatively, the CPU 31 may be informed of the type of the unit to be used, or the like. It is also possible to print some mark such as a bar code instead of the hole and optically detect the mark to obtain various information of the unit. When the CPU 31 knows various information of the unit,
It is possible to automatically perform various conditions of the electrophotographic process, such as laser power change and charging voltage change, according to the unit used. It is also possible to automatically set the life of various units, that is, the maximum number of prints for each unit.

Further, in the above-mentioned embodiment, the black cover is formed on the protective cover as a cleaning function, but the cleaning function is not limited to this. For example, the protective cover is coated with an adhesive to form the cleaning function. You may.

Although the above embodiments have been described with the present invention applied to a laser printer, the present invention is not limited to this, and can be applied to a copying machine or the like.

[0042]

As described above, according to the present invention, in the developing process unit in which at least the photoconductor is partially exposed, the developing process unit is provided with the protective cover, and the structure of the protective cover is simple and the cost is reduced. Moreover, the protection cover can easily distinguish between the unit in use and the unit not in use, and the practicality can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a developing process unit in the embodiment.

FIG. 3 is a diagram showing a configuration of a protective cover in the embodiment.

FIG. 4 is a block diagram showing a control circuit of the same embodiment.

FIG. 5 is a flowchart showing a unit mounting process in the embodiment.

FIG. 6 is a diagram for explaining the operation of the main part of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing | casing of apparatus main body 3 ... Transfer part 4 ... Fixing device 6 ... Paper conveyance path 7 ... Photosensitive drum 13 ... Development process unit 19 ... Sensor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41J 29/13 G03G 21/00 118

Claims (4)

[Claims] 1. An image forming apparatus in which at least a part of a photoconductor is exposed so as to form a unit, and the unit is detachably provided in an apparatus main body having a sheet transport mechanism, wherein the unit is an exposed portion of the photoconductor. An image forming apparatus is provided with a sheet-like protective cover for protecting the sheet, and the apparatus body is provided with control means for driving the transport mechanism when the unit is mounted to transport and discharge the protective cover. 2. An image forming apparatus in which at least a part of a photoconductor is exposed so as to form a unit, and the unit is detachably provided in an apparatus main body having a sheet conveying mechanism, wherein the unit is an exposed portion of the photoconductor. A sheet-like protective cover for protecting the protective cover is provided, and the apparatus main body drives the transport mechanism when the unit is mounted to transport and discharge the protective cover, and the presence or absence of the protective cover transported by the control means. An image forming apparatus, comprising: a sensor for detecting whether or not the unit is used, and determining whether the unit is used or not. 3. An image forming apparatus in which at least a part of a photoconductor is exposed so as to be a unit, and the unit is detachably provided in an apparatus main body having a sheet transport mechanism and a fixing device. Is provided with a sheet-like protective cover that protects the exposed portion of the fixing mechanism and a cleaning function of the transport mechanism and the fixing device, and the apparatus main body drives the transport mechanism when the unit is mounted, and the protective cover covers the fixing device. An image forming apparatus, characterized in that a control means for transporting and ejecting via an image forming device is provided. 4. An image forming apparatus in which at least a part of a photoconductor is exposed so as to form a unit, and the unit is detachably provided in an apparatus main body having a sheet transport mechanism, wherein the unit is an exposed portion of the photoconductor. A sheet-like protection cover for protecting the device main body and information on the number of times of unit use of the device main body, and the device main body drives the transport mechanism when the unit is mounted and transports and discharges the protective cover. An image forming apparatus comprising information reading means for reading unit usage number information from the protective cover conveyed by the control means.