JPH0968833A - Electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely electrically connect an image forming unit and a device main body by retreating a contact member with which the contact part of an image forming unit can come in contact before the image forming unit is loaded, and moving the contact member to a regular position after it is loaded. SOLUTION: As for a process cartridge (image forming unit) B, an electrifying contact part 14a, a developing contact part 14b and a drum contact part 14c respectively eletrically connected to an electrifying roller 4, a developing roller 5b and a photoreceptor drum 3 are exposed from the frame body of the cartridge. When the cartridge B is loaded in the device main body A, the contact parts 14a to 14c respectively come into contact with the pin-like contact members 15a to 15c provided on the device main body A side. The members 15a to 15c are held by a contact holder 16 so that they can move to a retreat position and the regular position with respect to a base plate 17 fixed in the device main body A. When the cartridge B is loaded in the device main body A, the members 15a to 15c are temporarily retreated, and they are restored to the regular position after the cartridge B is loaded therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus capable of reliably electrically connecting an image forming unit and an apparatus main body.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is used as an image forming apparatus. A process cartridge system detachable from the main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a service person, so that the operability can be remarkably improved. Therefore, this process cartridge method,
Widely used in image forming apparatuses.

In the above-mentioned image forming apparatus, it is necessary to apply a bias voltage to the developing means, charging means, etc. provided in the process cartridge. Therefore, the contact portion connected to the developing means and the charging means is exposed from the process cartridge, and when the process cartridge is mounted on the apparatus main body, the contact portion comes into contact with the contact member provided on the apparatus main body. The power source and the process cartridge are electrically connected.

[0004]

SUMMARY OF THE INVENTION The present invention is a further development of the above image forming apparatus, and its object is to mount an image forming unit such as a process cartridge in the main body of the image forming apparatus. The present invention provides an electrophotographic image forming apparatus in which a contact portion on the image forming unit side and a contact member on the apparatus main body side are normally brought into contact with each other so that reliable electrical connection can be performed.

[0005]

A typical constitution according to the present invention for achieving the above object is to provide an electrophotographic image forming apparatus which is capable of attaching and detaching an image forming unit and which forms an image on a recording medium. Mounting means for detachably mounting an image forming unit having a contact portion electrically connectable to the apparatus main body, a contact member contactable with the contact portion of the image forming unit, and image forming the image forming unit A contact moving means for moving the contact member to the retracted position before the movable member is mounted at the movable position, and for moving the contact member to the regular position when the image forming unit is mounted at the image forming position. It becomes a feature.

In the above structure, the contact member is temporarily retracted when the image forming unit is mounted on the apparatus main body, and when mounted, the contact member returns to the normal position. For this reason, the contact portion of the image forming unit and the contact member of the apparatus main body normally contact without lateral contact.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to the drawings.

First Embodiment First, an electrophotographic image forming apparatus to which a process cartridge according to the first embodiment can be mounted will be specifically described with reference to FIGS. 1 to 3. 1 is a schematic explanatory view of the configuration of an electrophotographic image forming apparatus in which a process cartridge is detachably mounted, and FIG.
FIG. 3 is a structural explanatory view of the contact moving means, and FIG. 3 is a sectional explanatory view of the contact portion of the process cartridge and the contact member of the apparatus main body as seen from the recording medium feeding side.

As the order of explanation, the overall construction of the electrophotographic image forming apparatus will be described first, and then the construction of the contact moving means will be described.

{Overall Configuration of Apparatus} In this electrophotographic image forming apparatus (original moving type copying machine), as shown in FIG. 1, the original table 1 can be moved to the upper part of the apparatus main body A (left and right direction in FIG. 1).
It is installed in. This document table 1 is a platen glass 1
The document is placed on a and is fixed by the document holder 1b. When reading manuscript information, the manuscript table 1 is moved with respect to the apparatus main body A, and the light source 2a irradiates the manuscript surface with light, and the reflected light is transmitted to the electrophotographic photosensitive member via the short focus lens array 2b. Irradiate.

A process cartridge B as an image forming unit is detachably mounted on the apparatus main body A. A photosensitive drum 3 having a photosensitive layer as an electrophotographic photosensitive member is provided at the center of the process cartridge B. The photosensitive drum 3 is rotated and its surface is transferred to a charging roller 4 as a charging means. It is uniformly charged by applying a voltage, and the reflected light from the document is supplied to the short focus lens array 2
The photosensitive drum 3 is exposed through b to form a latent image, and the latent image is developed by the developing means 5.

The developing means 5 sends out the toner in the toner storage portion 5a, rotates the developing roller 5b having a fixed magnet built therein, and at the same time, a toner layer to which a triboelectric charge is applied by the developing blade 5c is applied to the surface of the developing roller 5b. The toner image is formed and transferred to the photosensitive drum 3 according to the latent image to form a toner image, and the latent image is visualized. Then, after a voltage having a polarity opposite to that of the toner image is applied to the transfer charger (not shown) to transfer the toner image to the recording medium S, the cleaning blade 6a scrapes off the toner remaining on the photosensitive drum 3. The cleaning means 6 collecting in the waste toner storage portion 6b is configured to remove the residual toner on the photosensitive drum 3.

Further, in synchronization with the image formation, the recording medium S is conveyed from the feeding tray 7 by the conveying means 8 to transfer the toner image formed on the photosensitive drum 3, and the recording medium S is transferred.
Is discharged to the output tray 10 through the discharge fixing means 9. That is, the recording medium S loaded on the feeding tray 7 is separated and fed one by one by the separating roller 8b and the pressure contact piece 8c, and is sent to the image transfer portion by the registration roller pair 8d at the image forming timing. The toner image is transferred at the transfer portion. The recording medium S after the transfer of the toner image is applied with heat and pressure when passing through the fixing means 9, so that the toner image is fixed on the recording medium and is discharged to the discharge tray 10.

The fixing means 9 and the light source 2a are provided in the apparatus.
An exhaust heat fan 11 is provided to cool the heat generated from the.

The process cartridge B is attached to the apparatus main body A.
It is removably mounted by the mounting means. In this structure, as shown in FIG. 1, an upper frame 13 which is rotatable around a shaft 12 and can be opened and closed is provided on an upper portion of the apparatus main body A, and the process cartridge B is provided on an inner surface of the upper frame 13. Guide members 13a and 13b for supporting both ends of the process cartridge B are provided so as to face each other, and the process cartridge B is locked by a locking projection 13c formed at the tip of the guide members 13a and 13b. Insert B by inserting it from the front side to the back side in FIG. That is, when the process cartridge B is replaced, first, the document table 1 is manually moved to a position where the upper frame 13 can be opened and closed, and a hook (not shown) is operated to rotate the upper frame 13 (see FIG. 1). Rotate it about 90 ° so that the right end is lifted upward. Next, the used process cartridge B is pulled out from the upper frame 13 to the front side, and then the new cartridge B is inserted into the guide members 13a and 13b.
Insert so that it will be locked. Then, the process cartridge B is mounted at the image forming position by rotating the upper frame 13 by rotating it by about 90 ° so as to push it downward and closing it.

The process cartridge B is electrically connected to a charging contact portion 14a electrically connected to the charging roller 4, a developing contact portion 14b electrically connected to the developing roller 5b, and a photosensitive drum 3. The drum contact portion 14c is exposed from the cartridge frame. When the process cartridge B is attached to the apparatus main assembly A as described above,
The contact portions 14a, 14b, 14c contact the pin-shaped charging contact member 15a, the developing contact member 15b, and the earth contact member 15c provided on the apparatus main body A side, respectively, and the bias voltage of the charging roller 4 and the developing roller 5b is respectively applied. Can be applied,
Further, the photosensitive drum 3 is grounded via the apparatus main body A.

{Structure of contact moving means} The contact member 15
The contacts a, 15b, and 15c are held by a contact holder 16, and are configured to be movable between a retracted position and a regular position with respect to an electric board 17 fixed to the apparatus main body A. Next, the holding structure of the contact members 15a, 15b, 15c and the structure of the contact moving means will be described with reference to FIGS.

As shown in FIG. 1, for example, a charging contact member 15
At the lower end of a, a step portion 15d1 for being biased by a spring 18 made of a conductive member and a contact member 15a are provided in a contact holder.
A step portion 15d2 is formed so as not to come out from 16. The lower end of the spring 18 contacts the contact of the electric board 17,
The upper end of the contact member 15a is fitted to the lower end of the contact member 15a.
a is always biased upward. Energized contact member 15a
Is pushed upward and is in contact with the step inside the contact holder 16. As a result, the contact member 15a comes into pressure contact with the charging contact portion 14a of the mounted process cartridge B.

Incidentally, the other developing contact member 15b and the drum contact member 15c are also contact holders like the charging contact member 15a.
Held at 16.

Engaging claws 16a are provided on both sides of the contact holder 16.
Are provided, and the engaging claws 16a are loosely fitted in the engaging holes 17a provided in the electric board 17. Therefore, the contact holder 16 is movable up and down and is biased upward by the biasing force of the spring 18.

As shown in FIG. 1, when the process cartridge B is mounted at the image forming position, the contact portions 14a, 14b,
14c abuts on the contact members 15a, 15b, 15c, respectively, and the contact members 15a, 15b, 15c and the contact holder 16 are pushed downward by several mm.

A cam is provided above the contact holder 16.
19 are provided. This cam 19 is a D-cut type cam, and when the upper frame 13 rotates 90 °, the cam 19 will
It is configured to rotate 180 °. Then, as shown in FIG. 1, when the upper frame 13 is closed, the cam 19 has a lever member 20 whose D-cut surface pushes down the flat portion of the contact holder 16.
As shown in FIG. 2, when the upper frame 13 is opened, the arcuate surface of the cam 19 pushes the lever member 20 downward and the contact holder 16 downward.

As shown in FIG. 3, one end of the lever 20 is rotatably supported by a support member 22 provided on a bottom plate 21, and the right end of the lever member 20 abuts on a flat portion of the contact holder 16. ing.

Further, as shown in FIGS. 2 and 3, the cam gear 22 is loosely fitted on the shaft 22a so as to rotate integrally with the cam 19. The cam gear 22 meshes with a fan-shaped gear 24 via intermediate gears 23a and 23b, and the rotation center of the fan-shaped gear 24 is the upper frame body.
It is configured to coincide with the center of rotation of 13 and rotate integrally with the upper frame body 13. As a result, when the upper frame 13 is rotated, the cam 19 is rotated through the gear train, and the upper frame 13 is moved.
The gear ratio is set so that the cam 19 rotates 180 ° when rotated 90 °.

Incidentally, the cam gear 22 and the intermediate gears 23a, 23
The gear shafts 22a, 23a1 and 23b1 of b are the process cartridge B.
It is planted in a side plate 25 having a U-shaped groove for supporting the above, and this side plate 25 is provided with an escape hole 25a through which the lever member 20 penetrates.

In the above structure, when the process cartridge B is replaced or a jam (paper jam) is processed,
When the upper frame 13 is opened, the fan gear 24 rotates and the cam 19 turns 180.
When rotated, the arc surface of the cam 19 pushes down the lever member 20 as shown in FIG.
Press down. When the contact holder 16 is pushed down, the respective contact members 15a, 15b, 15c are also pushed down to the retracted position (movement loci of the contact portions 14a, 14b, 14c when the process cartridge B is mounted at the image forming position). To a position that is off). On the other hand, the process cartridge B moves upward together with the upper frame 13.

As a result, the process cartridge B can be replaced, and at the same time, a large opening is formed in the upper portion of the main assembly A of the apparatus, so that it is possible to easily carry out jam processing and the like.

Next, the process cartridge B is used as a guide member.
When the upper frame body 13 attached to 13a and 13b is closed, the cam 19 rotates accordingly, and when the upper frame body 13 is completely closed, the cam 19 rotates 180 ° from the open state. As a result, FIG.
Also, as shown in FIG. 3, the D-cut surface of the cam 19 faces the lever member 20, and the contact of the contact holder 16 moves upward due to the urging of the spring 18 because the cam 19 is no longer pressed. Along with this, the contact members 15a, 15b, 15c also move upward and return to the normal position, and these contact members 15a, 15b, 15c contact the contact portions 14a, 14b, 14c of the process cartridge B with proper pressure. The apparatus main body A and the process cartridge B are electrically connected to each other by contact.

That is, when the process cartridge B is mounted at the image forming position, the contact points 14a, 14b, 14c draw an arc locus along with the rotation of the upper frame 13, and at this time, the contact points on the apparatus main body A side. Since the members 15a, 15b and 15c are in the retracted position below, they are not twisted by the contact portions 14a, 14b and 14c. Further, when the process cartridge B is mounted in the image forming position, the contact members 15a, 15b, 15c
Moves to the normal position and comes into pressure contact with the contact portions 14a, 14b, 14c, so that side contact does not occur.

[Second Embodiment] Next, a second contact moving means will be described.
An embodiment will be described with reference to FIGS. 4 to 6.
Since the basic configurations of the apparatus main body A and the process cartridge B of the second embodiment are the same as those of the above-described first embodiment, members having the same functions are designated by the same reference numerals and overlapping description will be omitted. The configuration of the contact moving means will be omitted.

The process cartridge B of this image forming apparatus is one in which the process cartridge B is inserted from the top of the apparatus main body A so as to draw an arcuate locus and mounted.
To this end, bosses 26 are provided on both side surfaces in the longitudinal direction of the process cartridge B from the rotary shaft of the photosensitive drum 3, and guide grooves for guiding the bosses 26 are provided on both inner side walls 27 of the cartridge mounting space of the apparatus main assembly A. 27a is provided. This guide groove 27a has an arc shape,
By inserting the process cartridge B along the boss 26 with the 27a, the process cartridge B is inserted into the apparatus main assembly A.
On the other hand, it is inserted and attached so as to draw an arc locus from the state of the two-dot chain line in FIG. 4 to the state of the solid line.

On the other hand, in the contact moving means, as shown in FIG. 5, a D-cut cam 19 and a gear 28 are integrally rotatably fitted on a shaft 28a, and a fan-shaped gear is attached to the gear 28. 29
Are in mesh. The fan-shaped gear 29 is rotatable about a shaft 30 and an arm member 31 is integrally attached. The arm member 31 is located on the movement locus of the boss 26 when the process cartridge B is attached and detached, and is rotated by interfering with the boss 26 when the process cartridge B is attached and detached. A tension spring 32 is attached between the arm member 31 and the side wall 27, and the arm member 31 is urged clockwise in FIG. 5 and abuts on a stopper 27b provided on the side wall 27.

The contact members 15a, 15b, 15c are held by the contact holder 16 via the spring 18, and the contact holder 16
Is similar to that of the first embodiment in that it is configured to be loosely fitted in the engaging hole 17a of the board 17 by the engaging claw 16a and movable in the vertical direction. Here, the substrate 17 is pressed from the back surface by the leaf spring 33, the contact holder 16 is pushed upward as shown in FIG. 4, and when the lever member 20 is pushed down by the rotation of the cam 19, as shown in FIG. Is pushed downwards.

Therefore, when mounting the process cartridge B in the apparatus main assembly A, first, the document table 1 is manually moved to the left side as shown by the solid line in FIG. 4, and then the process cartridge B is set in the cartridge mounting space of the apparatus main assembly A. Push the boss 26 along the guide groove 27a. At this time, when it is inserted to the position shown in FIG. 5, the boss 26 comes into contact with the arm member 31, and when further pushed in, the arm member 31 rotates counterclockwise. This rotation causes the cam 19 to rotate, and when the process cartridge B is mounted at the image forming position (the position indicated by the solid line in FIG. 4), the D cut surface of the cam 19 completely faces the lever member 20. As a result, the lever member 20 and the contact holder 16 are no longer pressed by the cam 19 and moved to the upper normal position, and the contact members 15a, 15b, 15c are properly aligned with the contact portions 14a, 14b, 14c of the process cartridge B. Contact with different pressure.

When the process cartridge B is mounted at the image forming position, the protrusion 34 of the cartridge B engages with the movable engaging portion 35 of the main assembly A of the apparatus to prevent the process cartridge B from rising. Then, the original table 1 is returned to the position shown by the chain double-dashed line in FIG.

Next, when the process cartridge B is to be replaced or the jam processing is to be performed, the document table 1 is manually moved to the left side as shown by the solid line in FIG. 4 as in the case of mounting the process cartridge B. , The locking portion 35 is shifted to the right to release the engagement with the protrusion 34. Then the tension spring 32
The boss 26 is pressed by the arm member 31 by the urging force of the process cartridge B, the process cartridge B is pushed out from the position shown by the solid line in FIG. 4 to the position shown in FIG. Therefore, the process cartridge B
Can be easily taken out and replaced. Then, at this time, due to the rotation of the arm member 31, the cam 19 rotates from the state of FIG. 4 to the state of FIG. 5, and the arcuate surface pushes down the lever member 20. Therefore, the contact holder 16 is pushed down to the retracted position below.

Therefore, when the process cartridge B is mounted as in the first embodiment, the contact members 15a, 15b,
Since 15c is in the retracted position, the process cartridge B
The contact portions 14a, 14b, 14c of the above will not be twisted. Further, when the process cartridge B is mounted in the image forming position, the contact members 15a, 15b, 15c move to the regular positions and press-contact with the contact portions 14a, 14b, 14c, so that side contact does not occur.

[Third Embodiment] Next, a third contact moving means will be described.
An embodiment will be described with reference to FIGS. 7 and 8.
Since the basic configurations of the apparatus main body A and the process cartridge B of the third embodiment are the same as those of the above-described first embodiment, members having the same functions are designated by the same reference numerals and overlapping description will be omitted. The configuration of the contact moving means will be omitted.

FIG. 7 is a cross-sectional explanatory view of an original moving type copying machine, and FIG. 8 is a structural explanatory view of a contact member moving means.
In this embodiment, the document table 1 is rotatably supported integrally with the upper frame 36 about a shaft 37, and a hook (not shown) provided on the recording medium feeding side (left side in FIG. 7) is released. Then, the upper frame 36 is rotated by a torsion spring (not shown) attached to the shaft 37.
Rotates to the position indicated by the chain double-dashed line in the figure, and the process cartridge B can be replaced or jammed.

The upper frame 36 is provided with a fan-shaped gear 38 which rotates about the shaft 37. The gear 38 is an upper frame.
It rotates with the opening and closing of 36. As shown in FIG. 8, the gear 38 meshes with a small-diameter gear 39a of the step gear, and the large-diameter gear 39b of the step gear meshes with a cam gear 41 via intermediate gear trains 40a, 40b, 40c, and this cam gear 41 The D-cut cam 19 and the D-cut cam 19 can rotate together. The gear ratio of these gear trains is such that the cam 19 rotates 180 ° with the opening and closing of the upper frame body 36, and when the upper frame body 36 is opened, the arc surface of the cam 19 pushes down the lever member 20. When the frame 36 is closed, the cam 19D
The cut surface faces the lever member 20 and is separated from the lever member 20.

Further, the contact members 15a, 15b, 15c and the contact holder 16 are attached to the apparatus main body A as in the first embodiment.

Therefore, when the process cartridge B is mounted on the apparatus main assembly A, the upper frame 36 is first opened by rotating it from the position indicated by the solid line in FIG. 7 to the position indicated by the alternate long and two short dashes line. Cam at this time
As shown in FIG. 8, the arcuate surface of 19 pushes down the lever member 20, so that the contact members 15a, 15b, 15c move to the retracted position. Then, the process cartridge B is inserted along the guide portions 36a and 36b provided on the upper frame body 36, and the upper frame body 36 is inserted.
Close. At this time, as described above, since the cam 19 has the D-cut surface facing the lever member 20 as shown in FIG. 7, the contact holder 16 moves upward and the contact members 15a, 15b, 15
c moves to the regular position and contacts the contact portions 14a, 14b, 14c of the process cartridge B with proper pressure.

Therefore, in this embodiment as well, when the process cartridge B is mounted, the contact members 15a, 15b, 15c are in the retracted position when the process cartridge B is mounted, so that the contact portions 14a, 14b, 14c won't let you down. Further, when the process cartridge B is mounted in the image forming position, the contact members 15a, 15b, 15c
Moves to the normal position and comes into pressure contact with the contact portions 14a, 14b, 14c, so that side contact does not occur.

[Other Embodiments] Next, other examples of each part of the electrophotographic image forming apparatus according to the above-described embodiment will be described.

In the above-described embodiment, an example is shown in which the cam 19 is mechanically rotated with opening / closing of the upper frame or attachment / detachment of the process cartridge, but this may be performed electrically. For example, to describe the example of the third embodiment described above, in the configuration shown in FIG. 8, the shaft gear 43 of the motor 42 is meshed with the gear 40a, and the cam gear 41 is configured to be rotatable by the motor 42. Then, a switch for detecting the opening and closing of the upper frame body 36 is provided, and when the upper frame body 36 is closed and the switch is turned on, the arc surface of the cam 19 presses the lever member 20, and the upper frame body 36 is opened to switch the switch. The drive of the motor 42 is controlled so that the D-cut surface of the cam 19 faces the lever member 20 when is turned off. Even in this case, the same effect as that of the above-described embodiment can be obtained.

A solenoid is used instead of the motor, and the solenoid is operated in response to opening and closing of the upper frame 36,
This moves the lever member 20 up and down to bring the contact holder 16
May be moved up and down.

Further, although the process cartridge is exemplified as the image forming unit in the above-described embodiment, this process cartridge is not limited to the case of forming a single color image, but a plurality of developing means are provided and a plurality of color images (for example, two color images are formed). It can also be suitably applied to a cartridge that forms an image, a three-color image, a full-color image, or the like.

As the developing method, it is possible to use various developing methods such as a known two-component magnetic brush developing method, cascade developing method, touch-down developing method, cloud developing method and the like.

The electrophotographic photosensitive member is not limited to the above-mentioned photosensitive drum, but includes, for example, the following. First, a photoconductor is used as the photoconductor, and examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and an organic photoconductor (OP).
C) and the like. The shape on which the photoconductor is mounted includes, for example, a rotating body such as a drum or a belt, and a sheet. In general, a drum-shaped or belt-shaped one is used. For example, in the case of a drum-type photoconductor, a photoconductor is deposited or coated on a cylinder of an aluminum alloy or the like. It is.

As for the structure of the charging means, the so-called contact charging method was used in the above-described first embodiment, but a tungsten wire conventionally used as another structure is provided with metal shields such as aluminum around the three sides, It goes without saying that a configuration may be used in which positive or negative ions generated by applying a high voltage to the tungsten wire are moved to the surface of the photosensitive drum to uniformly charge the surface of the drum.

The charging means may be of a blade type (charging blade), a pad type, a block type, a rod type, a wire type or the like, other than the roller type.

Further, as a method of cleaning the toner remaining on the photosensitive drum, the cleaning means may be constituted by using a blade, a fur brush, a magnetic brush or the like.

The above-mentioned process cartridge is
For example, an electrophotographic photosensitive member and at least one of the process means
It is equipped with one. Therefore, as the mode of the process cartridge, in addition to the embodiment described above, for example, the electrophotographic photosensitive member and the charging unit are integrally made into a cartridge, which can be attached to and detached from the apparatus main body. The electrophotographic photosensitive member and the developing means are integrated into a cartridge,
A device that can be attached to and detached from the device body. An electrophotographic photosensitive member and a cleaning means are integrally formed into a cartridge so that the cartridge can be attached to and detached from the apparatus main body. Further, there is a type in which an electrophotographic photoreceptor and two or more of the above-mentioned process means are combined into a cartridge to be integrally detachable from the apparatus main body.

That is, the above-mentioned process cartridge is one in which the charging means, the developing means or the cleaning means and the electrophotographic photosensitive member are integrally formed into a cartridge, 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. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachable from the apparatus main body.

Further, the image forming unit is not limited to the process cartridge, but may be one in which only the developing means is attached or detached.

Further, in the above-described embodiment, the manuscript moving type copying machine is exemplified as the electrophotographic image forming apparatus, but the present invention is not limited to this, and for example, a laser beam printing machine, a facsimile machine, a word processor or the like may be used. Of course, it can be used for the electrophotographic image forming apparatus.

[0057]

As described above, according to the present invention, in the above structure, the contact member is temporarily retracted when the image forming unit is mounted on the apparatus main body, and the contact member returns to the normal position when mounted. Therefore, the contact portion of the image forming unit and the contact member of the main body of the apparatus are not twisted, and the contact is made normally without lateral contact.

[Brief description of drawings]

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

FIG. 2 is a configuration explanatory view of a contact member moving means according to the first embodiment.

FIG. 3 is a cross-sectional explanatory view of the contact member moving means according to the first embodiment as viewed from the recording medium feeding side.

FIG. 4 is a schematic explanatory diagram of an electrophotographic image forming apparatus according to a second embodiment.

FIG. 5 is a structural explanatory view of a contact member moving means according to a second embodiment.

FIG. 6 is a cross-sectional explanatory view of the contact member moving means according to the second embodiment as viewed from the recording medium feeding side.

FIG. 7 is a schematic explanatory diagram of an electrophotographic image forming apparatus according to a third embodiment.

FIG. 8 is a structural explanatory view of a contact member moving means according to a third embodiment.

[Explanation of symbols]

A ... Device main body, B ... Process cartridge, S ... Recording medium, 1 ... Original platen, 1a ... Platen glass, 1b ... Original pressing, 2a ... Light source, 2b ... Lens array, 3 ... Photosensitive drum, 4 ... Charging roller, 5 ... Developing means, 5a ... Toner storage section, 5b ... Developing roller, 5c Developing blade, 6 ... Cleaning means, 6a ... Cleaning blade, 6b ... Waste toner storage section, 7 ... Feed tray, 8 ... Conveying means, 8b ...
Separation roller, 8c ... Pressure contact piece, 8d ... Registration roller pair,
9 ... Fixing means, 10 ... Ejection tray, 11 ... Exhaust heat fan, 12 ...
Shaft, 13 ... Upper frame, 13a, 13b ... Guide member, 13c ... Locking protrusion, 14a ... Charging contact portion, 14b ... Developing contact portion, 14c ... Drum contact portion, 15a ... Charging contact member, 15b ... Developing contact Member, 15c ... Ground contact member, 15d1, 15d2 ... Step, 16 ... Contact holder, 16a ... Engaging claw, 17 ... Electrical board, 17a ... Engaging hole, 18 ... Spring, 19 ... Cam, 20 ... Lever member, 21 ... bottom plate,
22 ... Cam gear, 22a ... Gear shaft, 23a, 23b ... Intermediate gear,
23a1, 23b1 ... Gear shaft, 24 ... Fan gear, 25 ... Side plate, 25a ...
Escape hole, 26 ... Boss, 27 ... Side wall, 27a ... Guide groove, 27b ...
Stopper, 28 ... Gear, 29 ... Fan gear, 30 ... Shaft, 31 ... Arm member, 32 ... Extension spring, 33 ... Leaf spring, 34 ... Projection, 35 locking portion, 36 ... Upper frame, 36a, 36b ... Guide part, 37 ... Shaft, 38
... fan gear, 39a ... small diameter gear, 39b ... large diameter gear, 40a,
40b, 40c ... intermediate gear, 41 ... cam gear

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuaki Aoki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Yoshitaka Masuda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canono Within the corporation

Claims (5)

[Claims] 1. An image forming unit is removable,
In an electrophotographic image forming apparatus for forming an image on a recording medium, a mounting means for detachably mounting an image forming unit having a contact portion electrically connectable to the apparatus body, and a contact portion of the image forming unit A contact member that can be contacted, and the contact member is moved to the retracted position before the image forming unit is mounted at the image formable position, and the contact member is properly moved when the image forming unit is mounted at the image formable position. An electrophotographic image forming apparatus, comprising: a contact moving means for moving to a position. 2. The electrophotographic image forming apparatus includes an upper frame body that can be opened and closed by rotating with respect to a main body of the apparatus, the upper frame body having the mounting means, and the contact moving means includes the upper frame body. Is configured to move the contact member to a retracted position when it is rotated with respect to the apparatus main body, and to move the contact member to a regular position when it is rotated to close the upper frame body. The electrophotographic image forming apparatus according to claim 1. 3. The retracted position of the contact member is a position deviated from a movement locus of the contact portion when the image forming unit is mounted at an image formable position, and the regular position of the contact member is the normal position of the contact member. The electrophotographic image forming apparatus according to claim 1, wherein the contact member is in a position where the contact member comes into contact with the contact portion when the image forming unit is mounted in the image formation position. 4. The electrophotographic image forming apparatus according to claim 1, wherein the image forming unit is a process cartridge having an electrophotographic photosensitive member and at least one process unit acting on the electrophotographic photosensitive member. apparatus. 5. The electrophotographic image forming apparatus according to claim 1, wherein the image forming unit is a developing unit for developing a latent image formed on the electrophotographic photosensitive member.