JP2014224858A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to allow easy cleaning of an LED array, while preventing increase in installation space or size of the image forming apparatus.SOLUTION: An image forming apparatus 1 includes an exposure unit 5 for a latent image carrier 2, in a device body 1A formed of a housing which supports a process cartridge 3 having at least the latent image carrier 2 so as to be drawn out or inserted thereto. The exposure unit 5 can move between a position for exposing the latent image carrier 2, and a position facing a draw-out side of the process cartridge 3.

Description

  The present invention relates to an image forming apparatus, and more particularly to a moving structure of an exposure unit with respect to a removable image forming unit.

As is well known, in an image forming apparatus such as a copying machine, a printer, or a printing machine, an electrostatic latent image formed on a photosensitive member, which is a latent image carrier, is visualized by a developer supplied from a developing device. It is processed.
The visible image-processed toner image is transferred to a transfer material, and is then fixed by heating and pressurizing with a fixing device so that the toner melts and permeates to form a copy image.

  Some image forming apparatuses are configured to form not only a single color but also a plurality of colors such as full color. In the latter configuration, images of different colors formed in a plurality of image forming units are sequentially transferred (primary transfer) to an intermediate transfer member such as a belt, and then the superimposed image is transferred to a recording medium such as a recording sheet. In some cases, a batch transfer (secondary transfer) method is used.

On the other hand, when forming an electrostatic latent image, a configuration in which writing light corresponding to image information is irradiated onto a photoconductor is widely used. As one of the configurations, an LED array head is used for an exposure unit. Configurations that are known are known.
The LED array head is positioned in relation to the photoreceptor in the image forming unit. In some cases, the image forming unit employs a process cartridge system in which a charging device, a developing device, a cleaning device, and the like used for image forming processing including a photosensitive member are collectively accommodated. When a process cartridge is used, the LED array head is disposed at a position that can face the photoconductor.

In some cases, the process cartridge is detachably attached to the image forming apparatus for the purpose of opening the recording paper conveyance path when removing the recording paper in which component replacement or jamming has occurred. That is, a configuration in which the process cartridge is pulled out from the image forming apparatus is known.
In the configuration using the process cartridge described above, the LED array head may be retracted from the writing position with the photosensitive member when the process cartridge is pulled out. The reason for adopting such a configuration is that if the positional relationship between the photoconductor and the LED array head is fixed in advance, the surface of the photoconductor is damaged when it contacts the LED array head when the photoconductor moves. There is.

In the configuration in which the LED array head is retracted from the photosensitive member, the LED array head is provided on the inner surface of the opening / closing cover disposed on the upper surface of the apparatus body, and the LED array head is retracted from the photosensitive member by opening the opening / closing cover. The configuration is known (for example, Patent Document 1).
In addition, a configuration that does not use the above-described opening and closing of the cover has been proposed. In other words, the process cartridge has a configuration in which a raising / lowering guide portion of the LED array head is provided in a part of the process cartridge, or a configuration in which a drive mechanism that interlocks with the attachment / detachment operation is provided (for example, Patent Document 2). In this configuration, the LED array head can be retracted from the photosensitive member by moving the LED array head up and down in conjunction with the process cartridge attaching / detaching operation.

  In the configuration disclosed in Patent Document 1, since opening / closing the opening / closing cover is a condition for separating the LED head array and the photoconductor, there is a space for opening the opening / closing cover above the image forming apparatus. Necessary. This space is unrelated to image formation, and there is a problem that this space must be taken into account when installing the image forming apparatus. For example, it becomes impossible to install the image forming apparatus on a shelf or the like that tends to be a narrow space.

The configuration disclosed in Patent Document 2 does not require a space outside the image forming apparatus, but it is necessary to provide a space for the LED array head in the apparatus.
If the separation space is reduced so as not to increase the height of the image forming apparatus, there is a possibility that a space necessary for inserting a hand when the LED array head is cleaned cannot be obtained. Since the LED array head is used as an exposure unit that faces the photoconductor, discharge products scattered from the periphery, paper dust, or toner that is floating without being attached may adhere. If the light exit surface at the exposed portion is contaminated by these foreign substances, normal optical writing cannot be performed. For this reason, it is a member that needs to be cleaned.

  An object of the present invention is to reduce the installation space of the exposure unit used in the image forming apparatus in view of the problems in the conventional image forming apparatus and to easily clean the exposure unit even when the space is reduced. An image forming apparatus is provided.

  In order to achieve this object, the present invention comprises an apparatus main body comprising a housing in which a process cartridge is provided so that it can be pulled out and inserted, and a cover that is opened and closed when the process cartridge is drawn and inserted. The apparatus main body is provided with an exposure unit provided with an exposure unit corresponding to a light irradiation unit facing the latent image carrier, wherein the exposure unit includes a position for performing exposure and the process. An image forming apparatus is characterized in that the image forming apparatus is movable to a position directed to a cartridge drawing side.

  In the present invention, when the process cartridge is pulled out, the exposure unit can be moved to a position directed toward the process cartridge pull-out side, so that the space necessary for retracting the exposure unit can be saved and the exposure unit can be removed without taking out the exposure unit. It becomes possible to clean.

1 is a schematic diagram of an image forming apparatus for explaining a configuration that is a premise of an image forming apparatus according to an embodiment of the present invention; FIG. 3 is a schematic diagram for explaining an example of a characteristic portion of the image forming apparatus according to the embodiment of the present invention. It is a schematic diagram for demonstrating the position change of the LED array head used for the exposure part in the characteristic part shown in FIG. It is a schematic diagram for demonstrating an example of the effect | action in the characteristic part shown in FIG. It is a schematic diagram for demonstrating the time-dependent change of the effect | action in the characteristic part shown in FIG. It is a schematic diagram for demonstrating the principal part modification of the characteristic part shown in FIG. It is a schematic diagram for demonstrating the other principal part modification in the characteristic part shown in FIG. It is a schematic diagram for demonstrating the structure of the other characteristic part in the image forming apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an image forming apparatus having a configuration premised on the present invention.
In FIG. 1, an image forming apparatus 1 includes a photoconductor 2 that is used as a latent image carrier for forming a monochrome image.
The photosensitive member 2 is disposed inside a process cartridge 3 used in the image forming unit. The process cartridge 3 is provided so that it can be pulled out and inserted into the apparatus main body 1A constituted by a casing.

  Since the process cartridge 3 constitutes an image forming unit, the charging device 4, the exposure unit 5, the developing device 6, and the cleaning device 7 for the photoconductor after transfer, which are necessary for image forming processing on the photoconductor 2. Are housed together.

  On the other hand, a transfer roller 8 is disposed in the image forming apparatus 1 at a position facing the photosensitive member 2 in the process cartridge 3. With respect to the transfer roller 8, the recording paper fed out from the paper feeding device 9 disposed below is conveyed after the registration timing is set by the registration roller 10 and the transfer process is executed.

The paper feeding device 9 includes a paper feeding cassette 9A on which recording paper is mounted, a paper feeding roller 9B that feeds recording paper from the paper feeding cassette 9A, and a friction pad 9C that abuts against the paper feeding roller 9B to separate one sheet. ing.
After the transfer process by the transfer roller 8 has been completed, the recording sheet is conveyed to the fixing device 11 and fixed on the image, and then discharged to the discharge tray via the discharge roller 12.

  The process cartridge 3 may be pulled out when exchanging the components housed therein, performing maintenance inspections, or clearing a jam in the conveyance path provided near the process cartridge 3. Therefore, the apparatus main body 1A is provided with an opening for pulling out and inserting the process cartridge 3 and a cover 1B that can open and close the opening on the side wall of the housing.

When the process cartridge 3 is pulled out, it is necessary to eliminate the state in which the exposure unit 5 with the light irradiation unit facing the photosensitive member 2 interferes with the movement path of the process cartridge 3.
Therefore, the exposure unit 5 is rotatably provided on the apparatus main body 1 </ b> A side corresponding to a position different from the process cartridge 3.
The exposure unit 5 uses an LED array head 5A in which a large number of LEDs are arranged in the main scanning direction of the photoconductor 2, and is exposed when the light irradiation unit faces the photoconductor 2 as shown in FIG. The body 2 can be exposed.
When the process cartridge 3 is pulled out from the apparatus main body 1A, as shown in FIG. 2, the light irradiation part of the exposure unit 5 is rotated horizontally so as not to interfere with the movement space of the process cartridge 3 inside the apparatus main body 1A. To do.
As a mechanism for rotating the exposure unit 5, a configuration in which the exposure unit 5 is turned sideways by being kicked up by a part of the process cartridge is used. In this configuration, usually, a habit that the exposed portion faces the photoreceptor 2 is given.

The features of the present embodiment will be described as follows for the above-described configuration.
Although the feature of this embodiment is mentioned later, as shown in FIG. 3, it exists in the point provided with the structure which can be positioned in the position of the 1st-3rd multiple places.
In particular, when the process cartridge 3 is pulled out, the exposure unit 5 is directed to the drawing side of the process cartridge 3 and can be positioned in a state where the light irradiation unit of the exposure unit 5 can be cleaned from the outside.
Specifically, the LED array head 5A is structured so as to be movable from a position where it does not interfere with the drawing space of the process cartridge to a position where the light irradiation part is directed to the drawing side of the process cartridge 3.
In the present embodiment, first to third positions are determined as positions where the exposure unit 5 moves, and these first to third positions correspond to the following positions.
The first position is a position where the exposure unit 5 faces the photoreceptor 2, and the second position is a position where the exposure unit is directed to the drawing side of the process cartridge 3. The third position is a position where the exposure unit 5 moves away from the space for drawing out the process cartridge 3 and the light irradiation unit of the exposure unit 5 faces in the casing opposite to the drawing side of the process cartridge.

Positioning means for positioning the LED array head 5A used in the exposure unit 5 by moving the LED array head 5A to the first to third positions moves the LED array head 5A to the first to third positions as shown in FIG. A guide unit 100 that can be guided and an operation member 101 that can be operated from the outside are provided.
The guide portion 100 is formed on a side of the apparatus main body and is formed of a laterally U-shaped groove or rail, and the parallel positions correspond to the second and third positions.
That is, at the time of writing, the LED array head 5A of the exposure unit 5 is positioned at the bottom between the U-shaped parallel sides (first position), and moves from this position to the upper side of one of the parallel sides. Then, the LED array head 5A directs the light irradiation part into the housing (third position).
Then, when the exposure unit 5 located on the upper side moves to the lower side on the other side of the U-shaped parallel side, the direction is reversed in the middle, and the LED array head 5A emits the light. The irradiation unit is directed to the drawing side of the process cartridge 3 (second position).
The LED array head 5A is provided with a pair of guide pins 5A2 for sliding the guide portion 100, and one of them, that is, a guide pin provided at a position far from the light irradiation portion is also used as a rotation fulcrum. It is done.

As the operation member 101, a lever 101A urged toward the opening / closing cover located on the drawing side of the process cartridge 3 by an urging means (not shown) is used, and the LED array head 5A is supported on one side in the extending direction.
The other side of the operation member 101 in the extending direction opposite to the support position of the LED array head 5A is opposed to the cover 1B due to the urging behavior, and when the cover 1B is closed, the process cartridge 3 is pulled out to the drawing side. Movement is blocked.
The operation member 101 is a member that can be operated from the outside when the cover 1B is opened, and by this operation, the LED array head 5A can be moved to any one of the first to third positions. For this reason, when the cover 1B is opened, the operation member 101 can protrude outside from the drawer side space of the process cartridge 3, as shown in FIG. Note that the operation member 101 does not necessarily have to protrude to the outside of the housing, and it is sufficient that the position of the operation member 101 is known from the outside.

Since the present embodiment is configured as described above, the cover 1B is opened when the process cartridge 3 is pulled out. Thereby, as shown in FIG. 4, the drawer space of the process cartridge 3 is opened, and the process cartridge 3 can be pulled out.
When the cover 1B is opened, the operation member 101 of the positioning means protrudes outward from the cover 1B due to its own behavior, and can be operated from the outside.
The LED array head 5 </ b> A can move as the operation member 101 moves. The movement of the LED array head 5A in this case is the movement from the first position to the third position shown in FIG. 3, and the light irradiation section of the exposure section 5 is directed into the housing at a position that does not interfere with the drawer space. It will move to the position where it was.
By moving the exposure unit 5 away from the drawer space and moving to a position where it does not interfere, the process cartridge 3 can be moved without contacting the exposure unit 5.

FIG. 5 shows a state after the LED array head 5A has moved to a position where it does not interfere with the drawer space.
In this figure, when the operation member 101 is pushed into the housing against its own behavior by an external operation, the LED array head 5A can be moved toward the second position shown in FIG. it can.
The orientation of the LED array head 5A moved to the second position is reversed with respect to the third position and is directed to the drawing side of the process cartridge 3.
In this state, after the process cartridge 3 is pulled out, the exposed portion of the LED array head 5A can be cleaned.

  In the present embodiment, when the LED array head 5A moves from the first position to the third position, the orientation of the exposure unit turns into the housing, so that even if the hand is inserted during jam processing, the hand is exposed. I do not touch the part. Thereby, breakage and contamination of the exposed portion can be prevented. Moreover, since the exposure unit can be directed to the outside by moving the LED array head 5A to the second position, the exposure unit can be cleaned without requiring removal.

Next, a description will be given of a modification of the main part of the above characteristic part.
FIG. 6 is a view showing a holding mechanism for holding the LED array head 5A in the second position.
In the drawing, the holding mechanism has a configuration that holds the position of the operation member 101 opposite to the support position of the LED array head 5A when the operation member 101 is pushed to the position shown in FIG. Specifically, a notch-shaped locking portion 1C that can be engaged with a part of the operation member 101 provided on the housing side and corresponding to the position on the opposite side of the operation member 101 is provided on the operation member 101 side. Thus, an engagement pin 101B that can be fitted to the locking portion 1C is provided.
The locking portion 1C is formed with a concave portion 1C1 in which the engaging pin 101B can be inserted into a corresponding position when the operation member 101 moves the LED array head 5A toward the second position. .
When the operation member 101 moves the LED array head 5A to the second position, the locking pin 101B enters the concave portion 1C1, and thus the LED array head 5A is moved to the second position against the habit given to itself. Can be held in the position.

Next, another modified example of the main part in the above characteristic part will be described.
FIG. 7 is a view showing a modification of the configuration for positioning the LED array head 5A. In FIG. 7, an auxiliary member 200 that can be raised and lowered independently of the cover 1B is provided on the cover 1B side. .
The auxiliary member 200 has a shape that can cover the opening of the space for drawing out the process cartridge 3 when standing up, and is a member that lies down together with the cover 1B when the process cartridge 3 is drawn out as shown in FIG.
When the auxiliary member 200 falls down, the space for drawing out the process cartridge 3 is opened, and when the auxiliary member 200 stands up, it stands up in a state of covering the opening of the space for drawing out the process cartridge 3 and the process cartridge cannot be inserted from the outside. It becomes.

On the other hand, the auxiliary member 200 is positioned at a position where a part of the operation member 100 abuts against the operation member 100 when standing up.
When the LED array head 5 </ b> A is moved toward the second position by the operation member 100, the operation member 100 abuts against the auxiliary member 200 by bringing the auxiliary member 200 upright.
Thereby, the operation member 100 is stopped by the auxiliary member 200 and is prevented from moving, and the LED array head 5A can be held in the second position against the habit imparted to itself. it can.

Next, a modified example of the positioning means described above will be described.
FIG. 8 is a diagram showing a displacement state of the LED array head 5A by the positioning means.
The configuration shown in FIG. 8 does not include a mechanism that rotates the LED array head 5A that is the target of the configuration shown in FIGS.
Further, in this configuration, the first position of the exposure unit 5 is a position facing the photoconductor 2 as shown in the figure, and the second position is a position where the exposure unit 5 is directed to the drawing side of the process cartridge 3. It is. The third position is a position where the light irradiator is directed into the housing at a position where the exposure unit 5 is moved away from the drawing space of the process cartridge 3.
In the figure, the LED array head 5A is attached to the swing end of a support bracket 300 supported swingably by a support shaft 1D provided on the housing side.
The support shaft 1D is provided with a knob (not shown) that can be operated from the outside, and further, a locking mechanism that holds the LED array head 5A in the first to third positions.
As a locking mechanism in this case, although not shown, a ratchet wheel fixed to the support shaft 1D and a locking claw that can be engaged with and disengaged from the ratchet wheel by external operation are used. The ratchet wheel is provided with a locking tooth at a rotation position corresponding to the first to third positions, and one of the first to third positions is selected depending on the rotation position when the knob is rotated. can do. As a result, the support shaft 1D and the support bracket 300 constitute a rotation support mechanism for the LED array head 5A.

In this configuration, when the cover 1B is opened, the knob of the support shaft 1D is rotated to displace the LED array head 5A from the first position to the third position.
After the process cartridge 3 is pulled out, the LED array head 5A is rotated from the second position to the second position by a knob turning operation.

  In the above configuration, since the LED array head 5A is displaced to the first to third positions, the LED array head 5A can be operated only by the rotation of the LED array head 5A. Is no longer necessary. Thus, the LED array head 5A can be positioned at a cleanable position with a simple configuration.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1A Housing | casing 1B Cover 1C Locking part 1D Spindle 2 Photoconductor 3 Process cartridge 5 Exposure part 5A LED array head 100 Guide part 101 Operation member 101A Lever 101B Engagement pin 200 Auxiliary member

JP 2004-167728 A JP 2007-140293 A

Claims (10)

An image forming apparatus in which an exposure unit for the latent image carrier is provided in an apparatus main body including a housing that is supported so that at least a process cartridge including the latent image carrier can be pulled out and inserted.
The image forming apparatus according to claim 1, wherein the exposure unit is movable between a position where the latent image carrier can be exposed and a position directed toward the drawer side of the process cartridge.   The image forming apparatus according to claim 1, wherein the exposure unit is movable to a position that does not interfere with a drawing space of the process cartridge.   The image forming apparatus according to claim 1, wherein an LED array head is used for the exposure unit.   The exposure unit is located at a position where the latent image carrier can be exposed using an operation member operable from the outside and a guide unit provided on the apparatus main body side, and a position directed toward the drawing side of the process cartridge. The image forming apparatus according to claim 1, wherein the image forming apparatus is positioned.   The guide portion is provided on the housing side and is configured by a laterally U-shaped rail or groove, and one of the U-shaped parallel sides faces the exposure portion toward the drawing side of the process cartridge. 5. The image forming apparatus according to claim 4, wherein a bottom portion between parallel side portions is used for positioning the exposure unit so that the latent image carrier can be exposed.   The operating member includes a lever that is biased so that the exposure unit is supported on one side and the openable / closable cover provided on the housing on the other side. The image forming apparatus according to claim 4, wherein the exposure unit can be moved by operation.   The exposure unit is provided with positioning means for positioning the exposure unit at a position where the exposure of the latent image carrier can be performed and a position directed toward the drawing side of the process cartridge. The image forming apparatus according to claim 1, wherein a rotating mechanism is used.   The housing includes a holding mechanism that holds the exposure unit at a position directed toward the drawing side of the process cartridge. The holding mechanism is provided on the housing side and can be engaged with a part of the operation member. The image forming apparatus according to claim 1, further comprising an engaging portion.   The casing is provided with an auxiliary member that can be raised and lowered independently from the cover on the cover side, and when the cover is opened, the auxiliary member is raised to stop a lever used for the operation member. The image forming apparatus according to claim 1, wherein the exposure unit can be held at a position directed toward a drawing side of the process cartridge.   The image forming apparatus according to claim 9, wherein the auxiliary member stands up in a state of covering the opening of the drawer side space of the process cartridge when standing up.

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