JPH08262955A - Image forming device and process unit - Google Patents

Abstract

PURPOSE: To provide an image forming device and a process unit where the separated state of a blade from a photoreceptor drum in the process unit is released just by turning on a switch after the installation. CONSTITUTION: This process unit 100 is provided with an energizing means 102 for energizing cleaning means 16a and 16c toward an image carrier 10, and a preventing means 112 whose one end is engaged with a housing 101 side and whose other end is engaged with a cleaning means side so as to inhibit the movement of the cleaning means toward the image carrier. Then, releasing means 103, 104 and 16c are installed, which release at least either the engagement of the preventing means with the housing side or the engagement thereof with the cleaning means side.

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 in which a process unit having an image bearing member, cleaning means capable of abutting on the image bearing member, and a casing for supporting them is detachably provided, and An image carrier, a cleaning unit that can abut on the image carrier, and a housing that supports these units,
The present invention relates to a process unit detachably attached to an image forming apparatus.

[0002]

2. Description of the Related Art Next, a conventional example will be described with reference to the drawings.
FIG. 8 is a sectional view of a color razor printer which is an image forming apparatus, and FIG. 9 is a view showing a state in which the upper main body is opened in FIG.

In FIG. 8, a photosensitive drum 10 as an image bearing member having an OPC photosensitive layer coated on its surface is rotationally driven in one direction (clockwise in the figure), and static elimination is performed by a static eliminator 11 at the time of previous printing. After removal of the charge of 1, the peripheral surface is uniformly charged by the charger 120 to prepare for the next print.

The image exposure based on the image signal is performed by the image exposure means 13 by the mark of the uniform charging. Image exposure means 1
Reference numeral 3 denotes a laser beam emitted from a laser light source, which will be described later, is rotationally scanned by the rotating polyhedron 13A, and the optical path is bent by the reflection mirror 13C via the fθ lens 13B and the like, and the peripheral surface of the photoreceptor drum 10 that has been precharged. Projected on
A latent image is formed on the surface of the photosensitive drum 10.

Yellow around the photosensitive drum 10.
A developing device 14 filled with a developer in which toners such as (Y), magenta (M), cyan (C), and black (B) are mixed with a magnetic carrier is provided.

The toner is supplied to each developing device 14 from the toner hopper 40 of each color through the pipes 44, 45, 46 ,.
It is timely through 47. First,
The development of the first color is performed by the developing sleeve 14S which has a magnet built therein and rotates while holding the developer. The developer is regulated to a predetermined thickness on the developing sleeve 14S by the layer forming rod and is conveyed to the developing area. Photoconductor drum 1
0 and the developing sleeve 14S, AC bias voltage VA
C and DC bias voltage VDC are superimposed and applied.

Here, the potential of the exposed portion of the photosensitive drum 10 is VL, the surface potential of the charged photosensitive layer other than the exposed portion is VH, and the DC bias voltage VDC is | VH |> | VDC |> |
By setting so that VL | is satisfied, the toner that is given the opportunity to be separated from the carrier by the AC bias voltage VAC does not adhere to the portion of VH whose voltage is higher than VDC, and the toner of potential VL lower than VDC is applied. It adheres to the R-high portion, is visualized, and is developed.

After the development of the first color is completed in this way, an image forming process for the two-color surface (for example, magenta) is started,
The photoconductor drum 10 is uniformly charged again, and the image data of the two-color surface is formed by the image exposure means 13. For the third color (cyan) and the fourth color (black), the same image forming process as for the second color is performed, and a total of four colors are developed on the photosensitive drum 10.

On the other hand, the recording paper P fed by the paper feed mechanism 22 from the paper feed cassette 21 or the manual feed port 24 is
The transfer belt device 300, in which the transfer belt 331 is stretched, is fed to a nip portion (transfer area) 335 formed between the photoconductor drum 10 and the transfer belt 331, and is transferred to the nip portion (transfer area) 335 on the peripheral surface of the photoconductor drum 10. Color images are collectively transferred to the recording paper P. Here, the holding roller 3 on the upstream side of the transfer belt 331
A high voltage is applied to the shaft 332a of the shaft 32.
A conductive brush 334 is installed on one side of the sheet 32a, which is opposed to the transfer belt 331 with the transfer belt 331 interposed therebetween, and the recording paper P that has been fed enters the transfer area while being sucked by the brush 334 and the transfer belt 331. The recording paper P separated from the photoconductor drum 10 is separated from the transfer belt 331 while being neutralized by using the shaft 333b of the holding roller 333 on the downstream side that stretches the transfer belt 331 as a counter electrode. The transfer belt 331 is separated from the photosensitive drum 10 about the shaft 333b of the holding roller 333 on the downstream side as a rotation center during the formation of the multicolor image.

Recording paper separated from transfer belt device 300
P has a heater inside at least one roller 2
The toner is conveyed to a fixing device 23 composed of two pressure rollers, and heat and pressure are applied between the two pressure rollers to melt the adhered toner and fix the toner on the recording paper P. The paper is conveyed upward through the conveyance guide 25 and is carried out of the apparatus.

The toner remaining on the peripheral surface of the photosensitive drum 10 after the transfer is discharged by the static eliminator 15 and then reaches the cleaning device 16, and the cleaning device 16 is cleaned by the cleaning blade 16a which is in contact with the photosensitive drum 10.
It is scraped inside, carried out by a screw or the like, and stored in the collection box 17. The photoconductor drum 10 from which the residual toner has been removed by the cleaning device 16 is the static eliminator 1
After the charge is removed by 1, the charger 120 uniformly receives the charge, and then the image forming cycle is started.

Further, the recording sheet P is not separated from the transfer belt 331 and is wound around the photosensitive drum 10 to remove the static electricity.
5, the cleaning blade 16a
A jam sensor 336 that detects the wrapping of the recording paper P at an early stage is attached near the static eliminator 15 because it may damage the electrode wire or the electrode wire.

The above is a description of the state in which the upper main body 1B and the lower main body 1A are closed and the image formation is operable. Next, referring to FIG. 9, the upper main body 1B is attached to the rotary support shaft 2. Around
Explain the state in which it is opened by turning 45 °.

Between the upper body 1A and the lower body 1B,
A sensor (limit switch) is provided, and the open / closed state of the upper body 1A and the lower body 1B can be detected by the signal of this sensor.

The lower main body 1A is provided with a paper feed cassette 21, a paper feed mechanism 22, a transfer belt device 300, a fixing device 23, etc., and the upper main body 1B is provided with an image exposure means 13 and a developing device 1.
4 and the toner hopper 40 and the like, and further the process cartridge unit 100 in which the photoconductor drum 10, the PCL 11, the charger 120, the charge eliminator 15, the cleaner 16, the collected toner box 17 and the like are incorporated is the upper body frame of the upper body 1B. 18
It is provided to be removable.

Now, the process cartridge 100 will be described. As shown in FIG. 10, the cleaning device 16 of the process cartridge 100 is provided in parallel with the rotation axis of the photosensitive drum 10, and has a shaft 16b to which the base end of the blade 16a is attached and an intermediate portion at the end of the shaft 16b. Has a lever 16c attached thereto.

One end of the lever 16c is engaged with the casing 101 of the process cartridge 100, and the other end of the spring 102 is engaged with the casing 101 of the process cartridge 100.
The tip portion of 6a is urged in the direction of abutting on the peripheral surface of the photosensitive drum 10.

Reference numeral 103 denotes a drive source (developing motor) not shown.
And a cam plate which is rotationally driven through a clutch (not shown) and is provided on the device side. Reference numeral 104 denotes an arm having an intermediate portion rotatably provided on the apparatus side. One rotating end of this arm can contact the other rotating end of the lever 16c, and the other rotating end can contact the cam plate 103, respectively.

When the cam plate 103 rotates, the lever 16c is rotated via the arm 104, and the blade 16a comes into contact with the peripheral surface of the photosensitive drum 10.
/ It is designed to leave.

[0020]

In the process unit 100 of the color laser printer, which is the image forming apparatus having the above-described structure, the spring 102 biases the
The blade 16a contacts the peripheral surface of the photosensitive drum 10.
If the blade 16a is left in contact with the photosensitive drum 10, the peripheral surface of the photosensitive drum 10 may be scratched or deteriorated, or the contact portion of the blade 16a may be plastically deformed.

Therefore, as shown in FIG. 11, when the image forming apparatus is shipped or in the replacement process unit (unused process unit) 100, the projection 1 is formed on the side of the housing 101.
01a is provided, and the other end of the lever 16c and the protrusion 101 are provided.
The above-mentioned problem is solved by inserting the blocking member 110 between the a and the a, restricting the rotation of the lever 16c, and separating the blade 16a from the peripheral surface of the photosensitive drum 10.

However, when the image forming apparatus is installed or when the process unit 100 is replaced, the user may use the blocking member 11
There is a problem that the removal of 0 is forgotten and the removal of the blocking member 110 is difficult.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus and a process in which after a process unit is set, a state in which a blade is separated from a photosensitive drum is released without human intervention. To provide a unit.

Another object of the present invention is to provide an image forming apparatus and a process unit in which the blade of the process unit is released from the photosensitive drum by simply turning on the switch after installation. is there.

[0025]

Means for Solving the Problems A first method for solving the above problems is described below.
According to another aspect of the present invention, in an image forming apparatus in which a process unit having an image carrier, a cleaning unit that can abut on the image carrier, and a housing that supports them is detachably provided, the process unit includes the cleaning unit. A biasing means for biasing the means toward the image carrier, one end of which is engaged with the housing side, and the other end of which is engaged with the cleaning means side, and the cleaning means in the direction of the image carrier. Blocking means for prohibiting movement, and releasing means for releasing at least one of the engagement of the blocking means with the housing side and the engagement with the cleaning means side.

Here, as an example of the cleaning means which is biased toward the recording carrier by the biasing means,
A shaft provided parallel to the rotation axis of the image carrier,
A base end portion is provided on the shaft, a blade capable of contacting the cylindrical surface of the image carrier on the entire end portion side, and an intermediate portion on the shaft are provided so as to be rotatable in a plane orthogonal to the shaft. There is one that consists of a lever that has been opened.

The urging means is a spring which has one end locked to the casing and the other end locked to the lever and urges the blade in the direction of the cylindrical surface of the image carrier. Is desirable.

As an example of the blocking means, the blocking means is provided so as to be movable in the same direction as the axial direction of the shaft of the cleaning means, and the blade of the cleaning means does not come into contact with the cylindrical surface of the image carrier. There is a block which is engaged with a lever and which prohibits further movement of the blade in the direction of the image carrier, and a spring which urges the block in the axial direction of the shaft.

As an example of the releasing means, a cam plate rotatably driven on the image forming apparatus side and a rotatably provided on the image forming apparatus side, one rotation end of which is provided on the cam plate and the other of which is provided on the other side. The rotating end portion includes an arm that can contact the rotating end portion of the lever of the cleaning means, and the shape of the cam plate is such that the rotating end portion of the lever engages with the block via the arm. 1
And a shape in which the rotating end of the lever guides to two positions, a second position away from the block of the blocking means.

It is desirable that the releasing means be driven after the main switch is turned on or after the process unit is mounted. Further, as another example of the releasing means,
It may be a protrusion provided on the image forming apparatus side and capable of contacting the block of the blocking unit or the lever of the cleaning unit.

A second aspect of the present invention is a process unit which has an image carrier, a cleaning unit that can abut on the image carrier, and a housing that supports these units, and is a process unit that is detachable from an image forming apparatus. An urging means for urging the cleaning means toward the image carrier, one end of the urging means engages with the housing side, and the other end engages with the cleaning means side so that the cleaning means moves toward the image carrier. And a blocking means for inhibiting the movement of the blocking means, the blocking means being released after being set in the image forming apparatus.

[0032]

In the image forming apparatus according to the first aspect of the invention, after the process unit is set in the image forming apparatus, the releasing means on the image forming apparatus side releases the engagement of the blocking means of the process unit, and the urging means cleans the cleaning means. Contacts the image carrier.

In the process unit of the second invention,
The blocking means is released after setting the process unit.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a main part of an embodiment of the present invention, and FIG.
2 is a perspective view, FIG. 3 is a diagram illustrating a block in an initial state in FIG. 2, and FIGS. 4 and 5 are diagrams illustrating an operation in FIG.

In this embodiment, the same parts as those in the conventional example are designated by the same reference numerals, and their description will be omitted. 1 and 2, the shaft 16 is provided on the side surface of the housing 101.
A guide 111 extending in the same direction as b is provided, and a block 112 is slidably engaged with the guide 111. In addition, the block 112 has a housing 10 at one end.
The other end of the spring 113 locked to the side surface of 1 is locked and is urged toward the housing 101.

As shown in FIG. 3, the lower surface of the block 112 has a groove 112 into which the lever 16c can be engaged at a position where the blade 16a does not contact the peripheral surface of the photosensitive drum 10.
By engraving and engaging a, the block 112 is prohibited from moving in the direction of the housing 101, and the blade 16a is prohibited from moving in the circumferential direction of the photosensitive drum 10.

Next, the electrical connection structure of the image forming apparatus will be described with reference to FIG. Reference numeral 200 is a main switch of the image forming apparatus, 201 is an upper body detection sensor that detects whether or not the upper body 1B is closed, 202 is a developing motor, and 203 is a developing motor.
Is a clutch for turning on / off the driving force transmission of the developing motor 203 to the cam plate 103, and 204 is a timer.
Then, these are controlled by the control unit 205.

Next, the operation of the above configuration will be described with reference to FIGS.
This will be described with reference to FIGS. 6 and 7. FIG. 4 shows a state in which the power is not yet turned on after the image forming apparatus is installed, or a new process unit is set for replacement with the upper main body 1B of the image forming apparatus opened.

In this state, the groove 112a of the block 112 is engaged with the lever 16c, and the blade 16a is separated from the peripheral surface of the photosensitive drum 10. Next, the upper body 1B
When the main switch 200 of the image forming apparatus is turned on from off with the switch closed, or when the main switch 20
When 0 is off, the upper body 1B is connected to the upper body detection sensor 201
When it is detected that it has been closed (step 1), the developing motor 202 (not shown) is driven (step 2).

When the developing motor 202 is driven, the timer 2
04 and the clutch 203 are turned on (step 3), and the cam plate 103 rotates. The rotation time of the cam plate 103 can be adjusted by the set time of the timer 204, but in this embodiment, it is set to 2 seconds, which is the time for the cam plate 103 to search the initial position for at least one rotation (step 4). ).

When the cam plate 103 rotates, the arm 104 that can come into contact with the cam plate 103 swings to push the other end of the lever 16c and push the lever 16c downward.

Then, the engagement between the groove 112a of the block 112 and the lever 16c is released, the block 112 moves toward the housing 101 by the urging force of the spring 113, and the blade 16a moves toward the peripheral surface of the photosensitive drum 10. The state shown in FIG.

Thereafter, the blade 16a is in the state of FIG. 1 when the residual toner on the peripheral surface of the photosensitive drum 10 after transfer is scraped off by the rotation of the cam plate 103, and in the state of FIG. Take a position.

When the set time of the timer 204 has passed, the developing motor 202 and the clutch 203 are turned off,
A series of operations is completed. According to the image forming apparatus and the process unit configured as described above, the unused process unit 1
After setting 00 to the image forming apparatus, the power supply is turned on, and the blade 16a is separated from the photosensitive drum 10 without manpower, that is, without the conventional work of removing the blocking member. It can be canceled.

In the image forming apparatus in operation, the process unit is replaced and the upper main body 1b is closed.
The separated state of the blade 16a from the photosensitive drum 10 can be released.

The present invention is not limited to the above embodiment. For example, when the process unit 100 is set in the image forming apparatus by providing a protrusion on the side of the image forming apparatus that can abut the lower surface of the block 112, the protrusion pushes the lower surface of the block 112 upward to release the engagement with the lever 16c. It may be configured to do so.

[0047]

As described above, according to the image forming apparatus of the first aspect of the invention, after the process unit is set in the image forming apparatus, the blocking means of the process unit is engaged by the releasing means on the image forming apparatus side. It can be canceled.

In the process unit of the second invention,
The blocking means can be released after setting the process unit.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an embodiment of the present invention.

FIG. 2 is a perspective view of FIG.

FIG. 3 is a diagram illustrating a block in an initial state in FIG.

FIG. 4 is a diagram illustrating an operation in FIG.

FIG. 5 is a diagram illustrating an operation in FIG.

FIG. 6 is a block diagram illustrating electrical connection.

FIG. 7 is a flowchart illustrating an operation.

FIG. 8 is a cross-sectional view of a color laser printer which is an image forming apparatus.

9 is a diagram showing a state in which an upper body is opened in FIG.

10 is a configuration diagram of main parts of the process unit in FIG.

11 is a configuration diagram of a main part of the process unit in FIG. 10 when it is not used.

[Explanation of symbols]

 10 Photoreceptor Drum 16a Blade 16b Shaft 16c Lever 100 Process Unit 102 Spring 111 Guide 112 Block 113 Spring

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 21/10 G03G 21/00 318

Claims (8)

[Claims] 1. An image forming apparatus in which a process unit having an image carrier, a cleaning unit that can abut on the image carrier, and a casing that supports these units is detachably provided, wherein the process unit includes: Urging means for urging the cleaning means toward the image carrier, one end of the urging means engages with the housing side, and the other end of the urging means engages with the cleaning means side. And a releasing means for releasing at least one of the engagement of the blocking means with the housing side and the engagement with the cleaning means side. Image forming apparatus. 2. The cleaning means biased by the biasing means in the direction of the recording carrier has a shaft provided in parallel with a rotation axis of the image carrier, and a proximal end portion provided on the shaft. A blade that can be in contact with the cylindrical surface of the image bearing member on the entire end side, and a lever that is provided rotatably in a plane orthogonal to the shaft and that has an intermediate portion provided on the shaft. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 3. The biasing means is a spring that has one end locked to the housing and the other end locked to the lever, and biases the blade in the cylindrical surface direction of the image carrier. The image forming apparatus according to claim 1, wherein the image forming apparatus is provided. 4. The blocking means is provided so as to be movable in the same direction as the axial direction of the shaft of the cleaning means,
A block that engages with the lever at a position where the blade of the cleaning means does not contact the cylindrical surface of the image carrier and prohibits further blade movement in the direction of the image carrier; The image forming apparatus according to claim 1, further comprising a spring that urges the shaft in the axial direction. 5. The releasing means is rotatably provided on the image forming apparatus side, and a cam plate rotatably driven on the image forming apparatus side, and one rotation end portion is provided on the cam plate and the other rotating end portion. The end portion includes an arm that can abut the rotary end portion of the lever of the cleaning means, and the cam plate has a shape such that the rotary end portion of the lever engages with the block via the arm. Position of,
The image forming apparatus according to any one of claims 1 to 3, wherein the rotating end portion of the lever is shaped so as to guide it to two positions, that is, a second position away from the block of the blocking unit. 6. The image forming apparatus according to claim 1, wherein the releasing unit is driven after a main switch is turned on or after the process unit is mounted. 7. The releasing means is a projection provided on the image forming apparatus side, which is capable of contacting a block of the blocking means or a lever of the cleaning means. The image forming apparatus according to item 1. 8. A process unit detachably mountable to an image forming apparatus, comprising: an image carrier, a cleaning unit that can come into contact with the image carrier, and a housing that supports these units. Biasing means for urging in the body direction, and one end that engages with the housing side and the other end engages with the cleaning means side, and prevents the cleaning means from moving toward the image carrier. Means, and the blocking means is released after being set in the image forming apparatus.