JP3517475B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an electrophotographic or electrostatic recording type image forming apparatus, and more particularly to a transfer which forms a visible image on an image carrier and moves the visible image endlessly. The present invention relates to an image forming apparatus that obtains an image by transferring it onto a transfer material carried on a material carrier and conveyed, and can be suitably embodied in, for example, a multicolor or monochromatic electrophotographic copying machine or a laser beam printer.

[0002]

2. Description of the Related Art A color laser beam printer will be described as an example. This color laser beam printer
A drum-shaped electrophotographic photosensitive member, that is, a photosensitive drum, which is rotatably supported and rotates in one direction, as an image bearing member, is provided at a substantially central portion thereof. Around the photosensitive drum, a primary charger that uniformly charges the photosensitive drum, a laser beam exposure unit that irradiates image information to form a latent image, and a plurality of latent images that are developed to form a visible image (toner image). And a transfer material carrier which is a transfer drum for carrying and carrying the transfer material fed from the developing device and the paper feeding device. The toner image formed on the photosensitive drum is transferred to the transfer material on the transfer drum. The residual toner on the photosensitive drum is removed by a cleaning device, and the photosensitive drum is subjected to the next image forming process.

By repeating such an image forming process, a multicolor toner image is transferred and transferred onto the transfer material on the transfer drum.

After that, the transfer material is separated from the transfer drum, and the toner image is fixed on the transfer material by the fixing device and sent out of the apparatus.

[0005]

The present invention is a further development of the above-mentioned prior art.

According to the present invention, it is an object of the present invention to provide an image forming apparatus in which the attachment / detachment of the process cartridge cannot be performed unless the transfer material carrier is separated from the electrophotographic photosensitive drum.

[0007]

[Means for Solving the Problems] To achieve the above object
A typical configuration according to the present invention is an electrophotographic photosensitive drum.
Detachable in a direction orthogonal to the process cartridge and the conveying direction of the transfer material having, to form an image on the transfer material
In the image forming apparatus, the transfer material is carried and conveyed.
The toner image formed on the electrophotographic photosensitive drum.
A transfer material carrier for transferring to the transfer material, comprising:
The contact position where the photographic photosensitive drum is contacted, and the electrophotographic
Transfer material support that can be separated from the photosensitive drum
The holder and the process cartridge include the image forming apparatus.
In the mounting direction to be mounted on the main body of the
On the upstream side of the installed process cartridge
Place the process cartridge in a position that
A waste toner container detachably provided,
Waste toner that stores the toner removed from the photoconductor drum
-Separate the container and the transfer material carrier from the contact position
An operating member which is moved between the transfer position and the transfer material.
When the carrier is located at the contact position, the waste toner volume
The restriction part that restricts the removal of the container from the device body.
And an operating member having the same.

Another aspect of the present invention for achieving the above object
In the above configuration, the transfer material carrier is manually rotated.
A transfer material carrier rotating means, wherein the transfer material carrier is
When located at the contact position, the operating member is a transfer material carrier.
Characterized by restricting the operation of the manual rotation means
It

[0009]

[0010]

[0011]

[0012]

[0013]

Embodiments of an image forming apparatus according to the present invention will be described below in detail with reference to the drawings. The same members as those described above are designated by the same reference numerals.

(Embodiment 1) A first embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. 3 is an overall configuration diagram showing an image forming apparatus such as a full-color laser beam printer.

First, the overall structure of the color image forming apparatus will be schematically described with reference to FIG. As shown in FIG. 3, the color image forming apparatus of this embodiment has, for example, an electrophotographic photosensitive drum 4a as an image carrier, and an electrostatic latent image of each color formed on the photosensitive drum 4a by exposure. Are developed by the rotary developing device 5A to form toner images of respective colors, and the toner images of the respective colors are fed from the paper feeding device 1 and superimposed on the transfer material 2 wound around the transfer drum 3a which is a transfer material carrier. Transfer to form a color image. The transfer material 2 onto which the toner images of the respective colors have been transferred is separated from the transfer drum 3a and separated from the fixing portion 6
The toner image is mixed therewith and fixed on the transfer material 2 by fixing, and a full-color permanent image is formed. Then, the toner is discharged by a discharge roller 7 to a discharge portion 8 in the upper part of the apparatus.

The exposure of the photosensitive drum 4a is performed by the scanner section 10. The scanner unit 10 has a laser diode (not shown), and when an image signal is given, the laser diode generates image light λ corresponding to the image signal and irradiates it to the polygon mirror 10a. The polygon mirror 10a is rotated at a high speed by a scanner motor to reflect the image light λ, and the image light λ reflected by the polygon mirror 10a is exposed from the exposure section of the image carrier unit via the coupling lens 10b and the reflection mirror 10c. Body drum 4a
Are selectively exposed.

Next, the configuration of each part of the image forming apparatus will be described in detail.

The paper feeding device 1 is for feeding the transfer material 2 to the transfer drum 3a, and has a paper feeding cassette 1a for accommodating the transfer material 2 loaded in the bottom portion of the apparatus main body 9. At the time of image formation, the feeding roller 1b rotates in accordance with the image forming operation to separate the transfer materials 2 one by one from the paper feed cassette 1a and feed them to the transfer drum 3a. The transfer material 2 is fed to the transfer drum 3a through the registration rollers 1e while being guided by the guide plate 1c.

The transfer drum 3a winds the fed transfer material 2 and directs the toner image of each color on the photosensitive drum 4a to the image transfer portion facing the photosensitive drum 4a in order to transfer the toner image of each color onto the transfer material 2. 3 in the direction of the arrow in FIG.
It rotates at the same speed as the peripheral speed. The transfer drum 3a has a fixed shaft 3
By being rotatably supported by e, the drive force from the drive motor is transmitted to a gear (not shown) fixed to the transfer drum 3a so that the gear rotates in the direction of the arrow in accordance with the image forming operation.

At a predetermined position on the outer circumference of the transfer drum 3a, a gripper 3f for gripping the leading end of the fed transfer material 2 is provided. The transfer material guide member 3m guides the transfer material 2 when the tip of the transfer material 2 is gripped by the gripper 3f. Further, an electrostatic attraction roller 3g is provided so that it can be brought into contact with and separated from the outer periphery of the transfer drum 3a
Is provided, and the suction roller 3g transfers the transfer material 2 to the transfer drum 3
It is pressed against the outer periphery of the transfer drum 3a so as to be sandwiched between it and a. Then, by applying a voltage between the attraction roller 3g and the transfer drum 3a, the transfer material 2 that is a dielectric material is transferred.
And to induce an electric charge in a dielectric layer (not shown) of the transfer drum 3a,
The transfer material 2 is electrostatically attracted to the outer periphery of the transfer drum 3a.

The photosensitive drum 4a, which is an image carrier, has its rotation axis rotatably supported by the image carrier cover 4e. The photoconductor drum 4a is configured to rotate in the direction of the arrow in FIG. 3 in accordance with an image forming operation by transmitting a driving force from a drive motor to one end of its rotation shaft via a gear (not shown). . A primary charging device 4b and a cleaning device 4c are arranged on the outer circumference of the photosensitive drum 4a.

The above-mentioned primary charger 4b is disclosed in JP-A-63-1.
In the so-called contact charging method as disclosed in Japanese Patent Publication No. 49669, a conductive roller is provided, and the conductive roller is brought into contact with the photosensitive drum 4a and a voltage is applied to the conductive roller, whereby the photosensitive drum 4a. Uniformly charges the surface of.

Further, the cleaning device 4c includes a developing device 5 (5
(M, 5C, 5Y, 5K) is for cleaning the toner remaining on the photoconductor drum 4a after the toner image formed on the photoconductor drum 4a is transferred to the transfer material 2, and in this embodiment, The waste toner cleaned by the cleaning device 4c is transported to a waste toner container (not shown) attached to the side surface of the apparatus main body by a transport screw 4d inserted into the waste toner container. When the waste toner container is full of waste toner, it is removed and replaced with a new waste toner container.

The rotary developing device 5A has developing devices 5 for the respective colors, that is, developing devices 5M, 5C, 5Y and 5K provided with magenta, cyan, yellow and black toners. The developing devices 5 of these four colors are rotatably arranged around a rotation shaft 5e, and the centers of the respective developing devices 5 rotate in conjunction with a rotating gear arranged on the outer periphery of the revolving gear, and their postures. Is always kept constant.

At the time of image formation, the developing device 5 rotates about the shaft 5e, and the developing device 5 of the color corresponding to the latent image stops at the position of the developing device facing the photoconductor drum 4a, and further develops there. The developing sleeve 5b of the container 5 is the photosensitive drum 4
After being positioned so as to face a and a small gap (about 300 μm), the latent image on the photosensitive drum 4a is developed by the toner contained in the developing container.

In the developing device 5 for developing, the toner accommodated in the container is fed to the coating roller 5a by the feeding mechanism, and is rotated by the rotation of the coating roller 5a and the regulation of the toner layer pressure by the blade 5c. A predetermined thin toner layer is applied and formed on the sleeve 5b, and a triboelectric charge is applied to the toner.

At the time of development, a developing bias is applied between the developing sleeve 5b and the photosensitive drum 4a, whereby the toner on the developing sleeve 5b is transferred corresponding to the latent image on the photosensitive drum 4a, and the latent image is formed. Are developed and visualized as a toner image. The developing sleeve 5b of each developing device 5 is connected to a high-voltage power source for developing each color provided in the apparatus main body 9 when the developing device 5 is rotationally moved to the developing position, and a developing bias of a voltage selected for each color. Is applied.

As shown in FIG. 3, the fixing device 6 includes a pressure roller 6a that is rotationally driven, and a fixing roller 6b that presses the pressure roller 6a to apply heat and pressure to the transfer material 2. The transfer material 2 separated from the transfer drum 3 and sent to the fixing device 6 is
The toner image of each color on the transfer material 2 is fixed by the heat and pressure of the fixing roller 6b while passing through the fixing device 6 by being conveyed by the pressure roller 6a.

A cleaning member 6c is in contact with the fixing roller 6b, and the toner attached to the roller 6b is removed by the cleaning member 6c.

Next, the image forming operation of the image forming apparatus having the above-mentioned components will be described. By rotating the feeding roller 1b shown in FIG. 3, one transfer material 2 in the feeding cassette 1a is separated and is fed to the transfer drum 3a. Transfer drum 3a
Rotates in the direction of the arrow in FIG. 3, grips the tip of the transfer material 2 fed thereto by the gripper 3f, and electrostatically adsorbs it on its peripheral surface.

The photosensitive drum 4a is rotated in the direction of the arrow in FIG. 3 in synchronism with the rotation of the transfer drum 3a, the drum surface of the photosensitive drum 4a is uniformly charged by the primary charger 4b, and the scanner is also scanned. The unit 10 irradiates the image light λ of the magenta image to form a latent image of the magenta image on the photoconductor drum 4a. Simultaneously with this latent image formation, the magenta developing device 5M is driven to develop a developing bias voltage having the same polarity as the charging polarity of the image carrier and substantially the same potential so that the magenta toner adheres to the latent image formed on the photosensitive drum 4a. To develop a magenta toner image on the photosensitive drum 4a. Then, a transfer voltage having a polarity opposite to that of magenta toner is applied to the transfer drum 3a to transfer the magenta toner image on the photoconductor drum 4a onto the transfer material 2 on the transfer drum 3a.

When the transfer of the magenta toner image is completed as described above, the next developing device rotates to rotate the photosensitive drum 4a.
In the same manner, the cyan, yellow, and black latent images are formed, developed, and the obtained toner images are sequentially transferred, and a color image is formed on the transfer material 2.

After the transfer of the toner image is completed, the transfer material 2 is separated from the transfer drum 3a by the transfer material separating material 3u, conveyed to the fixing device 6, and after fixing the toner image by the fixing device 6, The sheet is discharged to the discharge section 8 by the discharge roller pair 7, and the image formation is completed. When the transfer material 2 is separated from the transfer drum 3a, the surface potential of the transfer drum 3a is adjusted by the transfer drum surface charge eliminating roller 3n to prepare for the next transfer material adsorption.
Next, the operation for taking out and replacing the process cartridge and the configuration and operation of each part will be described. In this embodiment, the drum-shaped electrophotographic photosensitive member 4a, the charging means 4b and the cleaning means 4c are integrally made into a cartridge, and the process cartridge 4 can be attached to and detached from the main body of the image forming apparatus.

A description will be given below in combination with FIG. 1, FIG. 2 and FIG. FIGS. 1 and 2 show a user operation unit for separating the transfer drum 3a from the photosensitive drum 4a in the apparatus main body shown in FIG. 3, and are diagrams that best show the features of the present invention.

Since the photoconductor coated on the surface of the photoconductor drum 4a is gradually worn away by image formation,
It is necessary to replace it every predetermined number of times of image formation. The photosensitive drum 4a is integrated with the peripheral primary charger 4b, the cleaning device 4c and the like by the cover 4e to form a so-called process cartridge 4, which is detached in this state.

Since the transfer drum 3a is normally pressed toward the photosensitive drum 4a, if the process cartridge 4 is attempted to be pulled out in this state, the photosensitive drum 4a and the transfer drum 3a will be damaged.

The photosensitive drum 4a is also used when the transfer material that is still held on the transfer drum 3a is removed by stopping the apparatus.
And the transfer drum 3a is damaged.

Therefore, the transfer drum 3a is replaced by the photosensitive drum 4
It is necessary to separate from a. A mechanism is provided for separating the transfer drum 3a from the photosensitive drum 4a.

In FIGS. 1, 2 and 3, the transfer drum 3a is supported by a spacing guide 20 having its shaft 3e fixed. A compression coil spring 21 is mounted inside the separation guide 20 and presses the shaft 3e of the transfer drum 3a toward the photosensitive drum 4a.

Further, a separating lever 30 for separating the transfer drum 3a from the photosensitive drum 4a is provided rotatably around a fixed shaft 31, and a protrusion 30d formed at an appropriate portion thereof forms a transfer lever of the transfer drum. It is in contact with the shaft 3e.

Normally, since the transfer drum 3a is pressed toward the photosensitive drum 4a by the urging force of the compression coil spring 21 provided inside the separation guide 20, the position of the separation lever 30 is set to the shaft 3e of the transfer drum 3a. Is determined by the position of.

When the process cartridge 4 is attached or detached, the manual separation cam 4 serves as means for separating the transfer drum 3a.
0s are arranged near both ends of the transfer drum 3a. The manual separation cam 40 extends in parallel to the longitudinal direction of the transfer drum 3a and is connected by a manual separation shaft 41 supported by a stationary bearing (not shown). In addition, the manual separation shaft 4
An operation lever 42 is fixed to one end portion of 1.

The lock arm 51 for restricting the attachment / detachment of the process cartridge 4 is supported by a guide member (not shown) slidably in the direction of the arrow in the figure. Overlaps. When the contact with the operating lever 42 is released, the lock arm 51 slides away from the pull-out portion of the process cartridge 4 by the action of the compression coil spring 52 (see FIG. 2) incorporated therein.

1 and 2 show a user's operation portion of the image forming apparatus having a mechanism for separating the transfer drum 3a from the photosensitive drum 4a as shown in FIG.

FIG. 1 shows a state in which normal image formation is performed.
A waste toner container 61 that stores residual toner that has not been transferred in the image forming process as waste toner is connected to the cleaning device of the process cartridge 4. In FIG. 1, the transfer drum 3a can be separated from the photosensitive drum 4a by tilting the operation lever 42 described in FIG. 3 in the direction of the arrow. A manual knob 53 for manually rotating the transfer drum 3a when removing the transfer material held on the transfer drum 3a is a gear (not shown) or the like.
Is combined with.

In FIGS. 1 and 3, when the operation lever 42 in the fixed position is rotated clockwise, the manual separation cam 40 is also integrally rotated via the manual separation shaft 41. When the manual separation cam 40 rotates, it comes into contact with the separation lever 30, and when the manual separation cam 40 further rotates, the protrusion 30d of the separation lever 30 causes the protrusion 30d of the separation lever 30 to move.
The shaft 3e of a is pressed, and the transfer drum 3a is separated from the photosensitive drum 4a against the biasing force of the compression coil spring 21. Further, the overlapping of the lock arm 51 with the drawer of the photosensitive drum cartridge 4 is released (FIG. 2).

In this way, the process cartridge 4 can be pulled out and replaced only when the operation lever 42 is operated to separate the transfer drum 3a from the photosensitive drum 4a. Therefore, an erroneous operation of pulling out the process cartridge 4 without separating the transfer drum 3a from the photosensitive drum 4a does not occur.

To attach the process cartridge 4 to the apparatus main body from the state in which the process cartridge 4 is removed, in the state shown in FIG. 2, the process cartridge 4 is inserted from the direction orthogonal to the paper surface of FIG. Rotates counterclockwise in the opposite direction and is mounted as shown in FIG.

(Second Embodiment) Next, a second embodiment of the image forming apparatus according to the present invention will be described with reference to FIG.
The same reference numerals are given to those having the same functions as those according to the above-described embodiment.

This embodiment is intended to prevent erroneous operation when the process cartridge is pulled out and replaced. FIGS. 4 and 5 show a user operation unit for separating the transfer drum 3a from the photosensitive drum 4a. The feature is that the operation lever 42 is integrally provided with a hook portion 42f overlapping the waste toner container 61. Is formed.

FIG. 4 shows a state during normal image formation. In this state, since the hook portion 42f overlaps a part of the waste toner container 61, the waste toner container 61 cannot be removed, and the process cartridge 4 located on the back side of the waste toner container 61 cannot be pulled out. is there.

In order to pull out the process cartridge 4, as shown in FIG. 5, first, the operation lever 42 is rotated in the direction of the arrow to release the overlap between the hook portion 42f and the waste toner container 61 and remove the waste toner container 61. I have to.

In this way, the process cartridge 4 can be pulled out and replaced only when the operation lever 42 is operated to separate the transfer drum 3a from the photosensitive drum 4a. Therefore, an erroneous operation of pulling out the process cartridge 4 without separating the transfer drum 3a from the photosensitive drum 4a does not occur.

(Third Embodiment) Next, a third embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. 6 and 7.

The present embodiment is intended to prevent erroneous operation of the manual knob when removing the transfer material that is still held on the transfer drum. FIG. 6 shows a user operation unit for separating the transfer drum 3a from the photosensitive drum 4a.
The features are the operation lever 42 and the manual knob 53.
That is, they are configured so that they overlap during normal image formation.

FIG. 6 shows a state during normal image formation. In this state, the operation lever 42 overlaps with the manual knob 53, so that the manual knob 53 cannot be operated.

In order to operate the manual knob 53, it is necessary to rotate the operation lever 42 as shown in FIG. 7 and release the overlap between the operation lever 42 and the manual knob 53.

By doing so, the manual knob 53 can be operated only when the operation lever 42 is operated to separate the transfer drum 3a from the photosensitive drum 4a. Therefore, the erroneous operation of operating the manual knob 53 without separating the transfer drum 3a from the photosensitive drum 4a does not occur.

(Fourth Embodiment) Next, a fourth embodiment of the image forming apparatus according to the present invention will be described with reference to FIG.

This embodiment is intended to prevent erroneous operation when the process cartridge is pulled out and replaced and the transfer material held on the transfer drum is removed. FIG. 8 shows a user operation unit for separating the transfer drum 3a from the photosensitive drum 4a. The feature is that the process cartridge 4 is interlocked with the operation lever 42.
Has a lock arm 51 for restricting the drawer replacement, and the operation lever 42 overlaps the manual knob 53 at the time of image formation, and the hook portion 42 is also attached to the waste toner container 61.
That is, f is configured to overlap. The operation of each of these features is the above-mentioned first to third.
As described in the description of the embodiment, the further description is omitted here.

By doing so, the transfer drum 3a is not separated from the photosensitive drum 4a in either case of pulling out and replacing the process cartridge 4 or removing the transfer material held on the transfer drum 3a. There is no mistaken operation.

In this embodiment, as the process cartridge 4, the electrophotographic photosensitive member, the charging means and the cleaning means are integrally formed as a cartridge, but the present invention is not limited thereto.

The process cartridge is a cartridge in which the charging means, the developing means or the cleaning means and the electrophotographic photosensitive member are integrally formed, and the cartridge can be attached to and detached from the main body of the image forming apparatus. Further, at least one of the charging means, the developing means, and the cleaning means and the electrophotographic photosensitive member are integrally made into a cartridge so that it can be attached to and detached from the main body of the image forming apparatus. Furthermore,
At least the developing means and the electrophotographic photosensitive member are integrally made into a cartridge so as to be attachable to and detachable from the apparatus main body.

[0064]

As described above, according to the present invention, the transfer
Contact position at which the copying material carrier contacts the electrophotographic photosensitive drum
And an operating member that moves between the
However, when the electrophotographic photosensitive drum contacts the transfer material carrier
In addition, this operating member is removed from the electrophotographic photosensitive drum.
The waste toner container that stores the accumulated toner from the main unit
I tried to regulate it. Therefore, electrophotographic exposure
When the body drum and transfer material carrier are in contact, waste toner
The process cartridge is removed from the main unit by the container.
It cannot be removed. And the electrophotographic photosensitive drum
When the toner carrier and the carrier are separated from each other, remove the waste toner container.
Since it can be removed from the main body of the device,
The tridge can also be removed from the device body. Obey
Damage the electrophotographic photosensitive drum and transfer material carrier.
Without removing the process cartridge from the main unit
It is possible.

[0065]

[0066]

[0067]

[0068]

[0069]

[Brief description of drawings]

FIG. 1 is a front view illustrating an operation unit of a transfer drum separating device according to a first embodiment of the present invention.

FIG. 2 is a side view showing the operation of FIG.

FIG. 3 is a vertical sectional view showing the color laser beam printer according to the first embodiment of the present invention.

FIG. 4 is a front view showing a second embodiment of the present invention.

5 is a side view showing the operation of FIG. 4. FIG.

FIG. 6 is a front view showing a third embodiment of the present invention.

FIG. 7 is a front view showing the operation of FIG.

FIG. 8 is a front view showing a fourth embodiment of the present invention.

[Explanation of symbols]

3a Transfer Drum 4 Process Cartridge 4a Photosensitive Drum 42 Operation Lever 51 Photosensitive Drum Cartridge Detachment Control Member (Lock Arm) 53 Manual Knob 61 Waste Toner Container

Continuation of front page (56) Reference JP-A-2-169441 (JP, A) JP-A-54-41731 (JP, A) JP-A-3-105363 (JP, A) JP-A-3-4245 (JP , A) JP 5-32348 (JP, A) JP 60-181756 (JP, A) JP 1-321443 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G03G 13/01 G03G 13/02 G03G 13/14-13/16 G03G 15/00 G03G 15/00 550 G03G 15/01-15/01 117 G03G 15/02-15/02 103 G03G 15/14- 15/16 103 G03G 21/10-21/12 G03G 21/16-21/18

Claims (2)

(57) [Claims] 1. An image forming apparatus for forming an image on the transfer material, wherein a process cartridge having an electrophotographic photosensitive drum is attachable / detachable in a direction orthogonal to a transfer material conveying direction, and the transfer material is carried and conveyed. A transfer material carrier for transferring the toner image formed on the electrophotographic photosensitive drum onto the transfer material, the contact position being in contact with the electrophotographic photosensitive drum, and the separation position from the electrophotographic photosensitive drum. And a transfer material carrier that can be spaced apart from each other, and in the mounting direction in which the process cartridge is mounted in the main body of the image forming apparatus, the process cartridge of the process cartridge is provided on the upstream side of the process cartridge mounted in the apparatus main body. A waste toner container detachably provided at a position that hinders removal, the toner being removed from the electrophotographic photosensitive drum. A waste toner container for storing the waste toner container, and an operation member for moving the transfer material carrier between the contact position and the separation position, wherein the waste toner when the transfer material carrier is located at the contact position An image forming apparatus, comprising: an operation member having a restriction portion that restricts removal of the container from the apparatus main body. 2. A transfer material carrying member rotating means for manually rotating the transfer material carrying member, wherein when the transfer material carrying member is located at the contact position, the operating member is a transfer material carrying member. The image forming apparatus according to claim 1, wherein the operation of the manual rotation unit is restricted.