JPH068595Y2 - Electrophotographic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial application field" The present invention relates to an electrophotographic apparatus for forming an image by an electrophotographic process such as a copying machine, a printer, a facsimile, and more specifically, a developing unit, etc. The present invention relates to an electrophotographic apparatus in which a process unit including at least a developing unit is detachably attached to an apparatus main body.

"Prior art" The electrostatic latent image formed on the photoconductor drum by using the laser beam modulated according to the input information and the reflected light corresponding to the original image is visualized on the photoconductor drum. After that, an electrophotographic apparatus such as a copying machine or a printer, which transfers the image to a transfer paper and forms a predetermined image, is well known, and in this kind of apparatus, in order to enable color change of developing toner and color development, 2. Description of the Related Art There is an apparatus in which a process unit including at least a developing unit (hereinafter referred to as a developing unit or the like) is configured to be detachable from an apparatus main body.

"Problems to be solved by the invention" In this type of apparatus, generally, for the convenience of maintenance, the developing unit and the like are configured to be detachable in parallel with the photosensitive drum axis. Since the photosensitive drum carrying the image and the developing roller (toner carrying member) incorporated in the developing unit or the like are arranged in contact with each other or at positions extremely close to each other, the developing unit or the like is detached from the main body of the apparatus or At the time of attachment, the developing roller may rub the surface of the photoconductor drum by mistake, which may damage the surface of the photoconductor drum.

For this reason, in such an apparatus, the developing unit is detached from the apparatus main body side after the developing unit is once separated from the photosensitive drum, but the so-called maintenance-free unit can be replaced by the consumer side. As the number of copiers increased, the developer unit may be directly removed from or mounted on the main body of the device without stepping away from the photoconductor drum, which often caused damage to the photoconductor drum. .

In view of the drawbacks of the prior art, the present invention is configured such that the developing unit and the like cannot be taken out before the photosensitive drum and the developing unit and the like are separated from each other. The purpose is to prevent damage accidents.

Another object of the present invention is to provide an electrophotographic apparatus capable of easily and simply replacing the developing unit and the like.

Another object of the present invention is to provide an electrophotographic apparatus in which backlash and rocking do not occur due to a large number of replacements of a developing unit or the like, or vibrations generated when various drive systems rotate. And

[Means for Solving Problems] In order to achieve the technical problem, the present invention allows a process unit including a drum unit including a photosensitive drum and a process unit including a developing roller to be attached to and detached from the apparatus main body in respective predetermined directions. In the electrophotographic apparatus configured as described above, a developing roller is provided with a process unit that is configured to be detachable in the direction in which the developing roller separates from and comes into contact with the photosensitive drum. A lever member for locking and unlocking the drum unit is provided by means of which the rocking member is rocked in conjunction with the turning operation of the lever member, and is rocked in a direction separating from the photoconductor drum while pressing the process unit. The point at which the swing member is provided is that the pressing force of the swing member causes the process unit to swing from the positioning position to the release position. That the elastic force biasing direction is switched capable elastic member provided with the positioning holding member of the process unit mounted in the kinematic process, it is an configuration requirements.

[Operation] Therefore, according to the technical means, when the drum unit or the process unit mounted in the apparatus main body is released, the rocking operation is performed by rotating the lever member from the engagement position of the drum unit to the release position. The moving member urges a pressing force in a direction of separating the process unit from the photoconductor drum, and the pressing force of the oscillating member causes the process unit to oscillate from the positioning position to the releasing position, and an elastic force is applied during the oscillating process. The urging direction is switched to the releasing direction, and the elastic force keeps the developing roller of the process unit away from the photosensitive drum.

Therefore, since the photoconductor drum is separated from the developing roller, the photoconductor drum is not damaged even when the drum unit is pulled out, and the pressing force of the positioning holding member is released in the process unit as well. , The process unit can be taken out easily.

On the other hand, when mounting the drum unit or the process unit on the apparatus main body side, after mounting the respective units, by operating the lever member to return from the release position of the drum unit to the engagement position,
First, the drum unit is locked.

Then, the swinging member swings in a direction away from the process unit in conjunction with the return operation, and then the positioning holding member swings from the positioning release position of the process unit to the positioning holding position, thereby swinging the swinging member. In the process, the process unit can be positioned while being elastically pressed by the position holding member while the elastic force urging direction is switched to the positioning direction.

Therefore, according to the technical means, the drum unit can be locked / unlocked and the process unit can be positioned / separated from the drum only by rotating / returning the lever, and the attachment / detachment work can be further simplified. .

In addition, it is possible to completely eliminate the possibility that the drum may be damaged when the units are attached or detached.

Further, since the positioning and holding of the developing unit is configured to be performed by the elastic biasing force, the rattling or the swinging is caused by the replacement of the developing unit or the like many times or the vibration generated when the various drive systems rotate. A clear image can always be formed without any occurrence.

Further, according to the present invention, since the pressure contact force of the holding means urged by the developing unit or the like is released in association with the separating operation from the photosensitive drum, when the developing unit is removed. It is possible to easily and easily replace the developing unit without burdening the weight of the developing unit.

In this case, the urging direction of the elastic urging force of the holding unit is switched in association with the separating operation of the developing unit or the like from the photosensitive drum, and the holding unit is separated from the pressure contact position of the developing unit or the like. By arranging it to move to the above position, the replacement work of the developing unit and the like can be further facilitated and simplified.

As such an elastic member, for example, a click crack spring, a leaf spring, or the like as shown in Examples described later can be cited.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be exemplarily described in detail with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but merely illustrative examples. Nothing more than.

1 to 5 show a laser printer according to an embodiment of the present invention in which a drum unit as well as a developing unit can be easily attached and removed, and FIG. 1 is an overall schematic view showing a state in which a tray, a paper feed cassette and the like are removed. 2 and FIG. 2 are plan views mainly showing the positional relationship between the developing unit and the drum unit, and the attachment / detachment mechanism for these units, FIG. 3 is a front sectional view of the essential parts mainly showing the positional relationship of various process means, and FIG. 4 is the developing unit. FIG. 5 is a perspective view showing the positioning and fixing means such as FIG. 5, and FIG. 5 is a front view of the essential portions showing the separating means between the developing unit and the drum unit.

In this apparatus, as shown in FIG. 1, an image corresponding to image information is obtained while a recording sheet fed from a sheet feeding cassette attached to a cassette mounting port 9 passes on a recording sheet conveying path formed in the apparatus. After being transferred and fixed, the sheet is discharged onto a tray (not shown) or a sorter through a discharge port 10 opened on the upper surface side of the apparatus.

A door 11 that can be opened and closed is attached to the center of the outer wall of the front side of the device. By opening the door 11, the drum shaft is opened.
Drum unit 1 that can be pulled out and installed in the 14a direction,
A lever member 5 for fixing and releasing the fixing of the drum unit 1.
And are exposed. Further, on the right side of the front outer wall in the figure, an operation panel 12 including operation buttons and a display unit is arranged.

Further, a lid 13 that can be opened and closed is attached to the upper surface side of the apparatus, and by opening the lid 13, toner can be introduced and the developing unit 2 can be taken out and attached.

The drum unit 1 is a photosensitive drum as shown in FIG.
14, a cleaning device 15, a charger 16, and a frame body 17 integrally supporting or rotatably supporting them, and rail guides 18 and 19 are formed at both upper and right corners of the upper end of the frame body 17. And the rail guides 18 and 19 as guides to the casings 3 and 4
By pulling out and pushing in the direction of the drum shaft 14a along the rails 7 and 8 installed between them, the unit 1 can be easily taken out and mounted in a predetermined position.

Further, the central portion of the upper surface of the frame body 17 is formed in a stepped shape, and the stepped opening is formed so as to guide the light of the static elimination lamp 21 fixed to the apparatus main body side to the surface of the photosensitive drum 14. There is.

A substantially square front cover member 22 (a portion indicated by a thick phantom line in FIG. 3) is fixedly provided on the front end side of the frame body 17, and the drum unit 1 is pulled out forward from the front surface of the front cover member 22. A handle portion 23 and a long groove opening 24 are formed on the side wall surface side thereof. When the lever member 5 is rotated, the developing unit and the drum unit are separated from each other, and the tip portion of the lever member 5 is engaged with the long groove opening 24. The drum unit 1 can be fixed (locked) by combining them.

On the other hand, above the photosensitive drum 14, an optical scanning unit 26 fixed at a predetermined position by a support wall 25 formed on the apparatus main body side.
However, a transfer device 27 is provided below the photosensitive drum 14, and a recording paper conveyance guide 28 and a registration roller 29 are provided at predetermined positions of the apparatus main body at the entrance side of the transfer device 27.

Further, the developing unit 2 is arranged in the space inside the apparatus between the optical scanning unit 26 and the conveyance guide 28 on the side of the photoconductor drum 14 with the developing roller 30 facing the photoconductor drum 14.

With this configuration, the laser beam emitted from the optical scanning unit 26 is imaged on the photosensitive drum 14 to form an electrostatic latent image, and the electrostatic latent image is visualized by the developing unit 2 and then transferred. It is possible to transfer the recording paper to the recording paper by the device 27, fix the image while the recording paper is conveyed along a conveyance path (not shown), and discharge the recording paper from the discharge port 10 to outside the apparatus.

Next, the developing unit 2 is operated by rotating the lever member 5.
The configurations of various members for separating and holding the position will be described with reference to FIGS. 2 to 5.

The developing unit 2 applies the toner whose layer thickness is regulated to the photosensitive drum.
Developing roller 30 and developing container to convey to the developing position on the 14 side
31 and includes guide pins 3 on the front and rear wall surfaces of the developing container 31.
2,33 are projected vertically.

Then, on the inner wall side of the housings 3 and 4 facing the front and rear wall surfaces of the developing container 31, the guide grooves 35 with which the guide pins 32 and 33 can be engaged.
A guide plate 34 having a concave shape is fixedly provided, and after the lid 13 formed on the upper surface side of the apparatus is opened, the developing unit 2 can be mounted and taken out by using the guide groove 35 as a guide. .

Further, at a space position below the developing unit 2 on the opposite side of the photoconductor drum 14 side, a support shaft 36 is provided in parallel with the drum shaft 14a and a housing 3,4.
The shaft 36 is rotatably supported in between, and one end portion of the support shaft 36 is provided so as to project to the outside of the front housings 3 and 4.

The base ends of a pair of swing members 6 are connected to the support shaft 36 at a position close to the center side, and the guide pin 3
A pair of pressure contact levers 40 are rotatably provided in the vicinity of the inner wall surfaces of the casings 3 and 4 corresponding to the casings 2 and 33, and further, the front casings 3 and 4.
The base end of one side of the support shaft 36 projecting to the outside of the link member 42 is connected to the base end of the link member 42 whose other end engages with the arcuate elongated hole 41 on the lever member 5 side via the pin shaft 43. .

The pair of oscillating members 6 extend at their tips to a position below the developing unit 2 on the photoconductor drum 14 side, and the oscillating members 6 rotate following the rotation of the support shaft 36, whereby the developing unit is rotated. 2 is obliquely upward along the guide groove 35, that is, the developing roller 30 can be pushed up in a direction away from the photosensitive drum 14.

The pair of pressure contact levers 40 extend obliquely upward along the wall surface of the developing container 31, and engage one end of a click crack spring 45 via a pin 44 at the center position thereof. Then, the other end of the click crack spring 45 is engaged with the pin 46 protruding from the wall surface of the developing container 31.

As shown in FIG. 5, the link member 42 is provided with a pin shaft 43 which is engageable with the arcuate elongated hole 41 of the lever member 5 on the tip side thereof, and is rotated by a predetermined angle following the rotation operation of the lever member 5. It is configured such that it moves and its rotation can be transmitted to the support shaft 36.

The lever member 5 is arranged such that its tip end side extends toward the opening of the long groove, and is rotatable about the rotary shaft 5a by the rotary operation of the grip portion 48 protruding on the front surface.
An arc-shaped elongated hole 41 having a 90 ° curvature is drilled around the periphery of the drum unit from an obliquely upper position toward the drum unit side so that the radial distance gradually increases, and as described above, the arc-shaped elongated hole 41 is inserted through the pin shaft 43. The link members 42 are connected.

Next, the operation of this configuration will be described.

First, when removing the developing unit 2 or the drum unit 1, after opening the front door 11, hold the grip 48 and hold the lever member 5
When is rotated clockwise to a position indicated by an imaginary line, the engagement between the drum unit 1 and the lever member 5 is released, and the link member 42 follows this and rotates by a predetermined angle to support the rotation. Transmission to shaft 36.

Then, the swinging member 6 rotates following the rotation of the support shaft 36,
The developing unit 2 is pushed up obliquely upward along the guide groove 35, and the developing unit 2 is separated from the photosensitive drum 14.

Further, when the developing unit 2 is pushed up obliquely upward along the guide groove 35 by the pressing of the swing member 6, the press contact lever 40 pressing the guide pin 32 is rotated by a predetermined angle and one end thereof is The click crack spring 45 engaged with the press contact lever 40 is bent to a predetermined angle, whereby the elastic force urging direction of the spring 45 is switched, and the press contact lever 40
Is separated from the guide pin 32 and is rotationally locked to a vertically upper position.

Therefore, in this state, since the photosensitive drum 14 and the developing roller 30 are separated from each other, the photosensitive drum 14 will not be damaged even if the drum unit 1 is pulled out.

Further, in the developing unit 2 as well, since the pressing force with the pressing lever 40 is released and the developing unit 2 is in a free state, the developing unit 2 can be easily taken out along the guide groove 35 by opening the lid 13.

Then, after re-installing the developing unit 2 along the guide groove 35 and the drum unit 1 along the rails 7 and 8, respectively, the lever member 5 is tilted to the drum unit 1 side, so that the long groove opening 24 of the drum unit 1 is formed. The drum unit 1 is locked by engaging with the lever member 5, and
The support shaft 36 rotates counterclockwise via the link member 42, the swinging member 6 rotates downward following the rotation of the support shaft 36, and the developing unit 2 moves along the guide groove 35. By sliding, the developing roller 30 is positioned at a predetermined position facing the photoconductor drum 14.

When the developing unit 2 further slides downward, the click crack spring 45 is bent and bent to a predetermined angle, the elastic force urging direction of the spring 45 is switched downward, and the pressure contact lever 40 is rotated to the guide pin 32 side. The developing unit 2 is pressed against the developing pin 2 via the guide pin 32, and the developing unit 2 is positioned and held by the elastic biasing force of the spring 45.

Therefore, according to such an embodiment, by rotating the lever member 5, the developing unit 2 can be automatically released while the drum unit 1 and the developing unit 2 are separated from each other, and the lever member 5 can be returned. By this, the developing unit 2 is automatically positioned and held at a predetermined position, and the developing unit 2 can be replaced very easily, and the photosensitive drum 14 and other various members may be damaged during the replacement work. There is no

[Advantages of the Invention] As described above, according to the present invention, it is possible to completely prevent the photoconductor drum from being damaged when the developing unit or the like is replaced, and to easily and simply replace the developing unit or the like. It becomes possible to change.

Further, according to the present invention, a vivid image can be always formed without rattling or rocking due to a large number of replacements of the developing unit or the like or vibrations generated when various driving systems rotate.

[Brief description of drawings]

1 to 5 show a laser printer according to an embodiment of the present invention in which a drum unit as well as a developing unit can be easily attached and removed, and FIG. 1 is an overall schematic view showing a state in which a tray, a paper feed cassette and the like are removed. FIG. 2 is a plan view mainly showing the positional relationship between the developing unit and the drum unit, and the attachment / detachment mechanism thereof, FIG. 3 is a front sectional view of an essential part showing mainly the positional relationship of various process means, and FIG. FIG. 5 is a perspective view showing the positioning and fixing means of FIG. 5, and FIG. 5 is a front view of the essential portions showing the separating means between the developing unit and the drum unit. 2: Development unit, 40: Holding means (pressing lever) 45: Elastic member (click crack spring) 14: Photosensitive drum, 5: Separation means (lever member)

Claims (1)

[Scope of utility model registration request] 1. In an electrophotographic apparatus in which a drum unit including a photosensitive drum and a process unit including a developing roller are detachably attached to a main body of the apparatus in respective predetermined directions, the developing roller is separated from the photosensitive drum. A process unit configured to be detachable in the contact direction, a lever member that is pivotably operated to engage a part of the drum unit, and locks and unlocks the drum unit by the pivot operation; An oscillating member that oscillates in an interlocking manner and oscillates the process unit in a direction away from the photoconductor drum while pressing the process unit; The position of the process unit in which the elastic member is attached so that the elastic force bias direction can be switched during the swinging process. And a holding member, and by rotating the lever member from the engagement position to the release position of the drum unit, the swing member urges a pressing force in a direction of separating the process unit from the photosensitive drum, The pressing force of the swing member causes the process unit to swing from the positioning position to the release position, and in the swinging process, the elastic force biasing direction switches to the release direction, while the lever member is engaged from the release position of the drum unit. The swinging member swings in the direction away from the process unit by returning to the position, and then the positioning holding member swings from the positioning release position of the process unit to the positioning holding position to swing the swinging member. An electronic copying device characterized in that the process unit can be positioned while the elastic force urging direction is switched to the positioning direction during the process. Equipment