JP2003280407A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus by which the occurrence of a defective image is prevented and whose maintenance property is improved by optimizing the positioning of devices with each other in the case that a cartridge structure attachable/detachable to/from a device main body is provided. <P>SOLUTION: The image forming apparatus is constituted of the device main body possessing several juxtaposed image forming parts 1, a transfer means 13 provided opposed to several image forming parts 1 at the device main body and to successively transfer images formed by several image forming parts 1 and a supporting means 16 provided at the device main body, to freely turnably support the transfer means 13 at a first position at which the transfer means 13 gets near to the image forming parts 1 and performs transfer and a second position at which the transfer means 13 is separated from the image forming parts 1 and to set the transfer means 13 in a posture in which it is made attachable/detachable when the transfer means 13 is at the second position. <P>COPYRIGHT: (C)2004,JPO

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, and more particularly, to a structure for improving the maintainability of constituent members used for forming images of a plurality of colors.

[0002]

2. Description of the Related Art Images to be image-formed may include not only a single color but also a plurality of colors. In this case, full color or selected colors are targets.

For forming images of a plurality of colors, there is a structure in which a plurality of image forming portions are provided and the images formed by the respective image forming portions are superimposed and transferred. As one of the configurations for this, there is a configuration in which the device to be replaced is made into a cartridge and installed in the image forming unit.

[0004]

In recent years, in the image forming apparatus, a structure has been adopted in which each apparatus for executing the image forming process is formed into a cartridge as described above and can be replaced according to the degree of wear. However, when replacing the cartridge, the cartridge is attached to and detached from the device body,
Assembly error is likely to occur between each device. For this reason, for example, if the positional relationship between the photoconductor and the transfer target member is not appropriate, image misregistration and insufficient transfer of toner tend to result in defective transfer.

In view of the above-mentioned problems in the conventional image forming apparatus, an object of the present invention is to optimize the positioning of the apparatuses in the case of having a cartridge structure that can be attached to and detached from the apparatus main body and prevent the occurrence of defective images. And an image forming apparatus having a configuration capable of improving maintainability.

[0006]

The invention according to claim 1 is
An apparatus main body having a plurality of image forming sections arranged side by side, and a plurality of image forming sections in the apparatus main body, which are provided to face each other,
A transfer unit capable of sequentially transferring the images formed by the plurality of image forming units; a first position provided in the apparatus main body and capable of transferring by bringing the transfer unit close to the image forming unit; The transfer unit is rotatably supported at a second position in which the transfer unit is separated from the image forming unit, and the transfer unit is detachable when the transfer unit is at the second position. It is characterized by comprising possible supporting means.

According to a second aspect of the present invention, in addition to the first aspect of the invention, the supporting means is configured to support the transfer means by inserting a part of the transfer means. I am trying.

The invention according to claim 3 is the invention according to claim 1 or 2.
In addition to the invention described above, the transfer means is provided with a first engaging portion, and the supporting means is provided with a second engaging portion into which the first engaging portion can be inserted and removed. It is characterized in that the transfer means is supported by the supporting means by inserting the first engaging portion into the second engaging portion.

According to a fourth aspect of the present invention, in addition to the invention according to any one of the first to third aspects, the supporting means is axially supported by the casing of the apparatus main body and is at the first position. And the second position.

According to a fifth aspect of the present invention, in addition to the third aspect of the present invention, the first engaging portion of the transfer means has widthwise opposite ends corresponding to a direction perpendicular to the moving direction of the transfer means. It is characterized in that it is provided on the side surface of.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to embodiments shown in the drawings. The image forming apparatus according to the embodiment of the present invention is intended for an image forming apparatus capable of obtaining a full-color image by superimposing and transferring a plurality of separated color images on the conveyor belt 10 as shown in FIG. The full-color image forming apparatus shown in FIG. 1 has a plurality of image forming units arranged along a sheet conveying path, and different colors are sequentially transferred each time a recording sheet passes through each image forming unit, and a final color is finally transferred. A full-color image is obtained by superimposing four colors. Each image forming unit includes a plurality of drum-shaped photoconductors 1 that function as an image forming medium.
The rotation direction around the photoconductor 1 (counterclockwise in FIG. 1)
A charging device 2, an exposure device 4, a developing device 3, and a cleaning device 5 are arranged along the line. Note that in FIG. 1, reference numeral 1 is shown for the sake of convenience for one drum-shaped photoconductor, but in reality, cyan, yellow, magenta, and black color images corresponding to complementary colors of the color-separated colors are formed. Since the drum-shaped photoconductors are arranged in parallel, and the remaining three image forming units have the same configuration as described above, the description thereof will be omitted.

The surface of the photoconductor 1 is uniformly charged by the charging device 2, and then is exposed or optically written by the exposure device 4 in a pattern corresponding to the image to be output, and an electrostatic latent image is formed on the surface of the photoconductor 1. An image is formed. The electrostatic latent image is developed by the developing device 3 to form a toner image, and the toner image is transferred onto the paper. The toner remaining on the surface of the photoconductor after the transfer is removed by the cleaning device 5. In the pattern exposure or optical writing process, a color separation image signal sent from a personal computer (not shown) is subjected to color conversion processing by an image processing unit (not shown) based on the intensity level thereof, and black (BK) and magenta (M). , Yellow (Y) and cyan (C) are converted into color image data, and exposure or optical writing is performed by the exposure device 4 based on this data. It should be noted that in FIG. 1, the regions including the photoconductor 1 that forms the image of each color described above are indicated by reference characters Y, M, C, and BK.

A laser scanner is used as the exposure device 4, and this laser scanner reflects a laser beam from a laser light source by a polygon scanner 6, and further bends an optical path and narrows a light diameter by an fθ lens 7, The surface of the photoconductor 1 is exposed and scanned. In this laser scanner, as the polygon scanner 6 rotates, writing is performed with the axial direction of the photoconductor as the main scanning direction, and the rotation of the photoconductor 1 causes subscanning in a direction perpendicular to the axial direction of the photoconductor 1. Writing is done as a direction.

For superimposing the respective colors, the timing at which the recording sheet S sent from the paper feeding section 8 is conveyed from the resist section 9 to the transfer position of each color by the conveyor belt 10 and the image on each photoconductor is moved to the transfer position. It is performed by setting the exposure start time so that the timing of movement is the same for all colors. After the transfer, the image is fixed by the fixing device 11 and is discharged to the paper discharge unit 12 such as a tray.

As shown in FIG. 6, the transfer / conveyance unit, which is a means for transferring the image formed in each image forming section, is detachable from the main body of the apparatus. 6, the transfer / transport unit 13 is provided with a pair of belt rollers 10A and 10B in FIG.
B is a conveyor belt 10 made of a light-transmittable material.
Is hung around.

The conveyor belt 10 carries a recording sheet and provides an image from each photoconductor 1 for transfer, and also conveys the image from each photoconductor 1 toward the fixing portion when the superimposition transfer of the image is completed. The recording paper in this case is electrostatically or mechanically carried at a fixed position. The transfer / conveyance unit 13 is provided with a cover 131 that can cover the portion of the conveyor belt 10 that is wound around the belt roller. Cover 131
An opening 131A (for convenience, see FIG. 2 used to describe the embodiment of the present invention) is formed in a part of the opening 131A.
Therefore, the conveyor belt 10 is exposed to the outside.

On the transfer / conveyance unit 13 side near the opening 131A, image position detection, which will be described later, can be performed. Therefore, the transfer / conveyance unit cassette 16 is provided.
A light receiving unit 14 that is one of the image position detection sensors is provided facing the light emitting unit 18 located on the side. Light receiving part 14
The transport belt 10 facing the transfer / transport unit 13
Positioning is performed for setting an optical distance via a guide rail 131B provided on the. The light receiving unit 14 is equipped with a circuit board (not shown) including a photosensor and an amplifier that amplifies a photoelectrically converted signal. The image position detection sensor is for detecting a toner mark (not shown) formed on the conveyance belt 10, and the conveyance belt is arranged so that the image transfer start position from each photoconductor to the recording sheet is aligned. 10
It is used as a component of means for controlling the driving state of the.

The transfer / conveyance unit 13 has guide rails 13B having protrusions on both side surfaces in the width direction corresponding to the direction perpendicular to the moving direction of the conveyor belt 10 (only protrusions are shown in FIG. 2) is provided. The guide rail 13B is attachable to and detachable from a mounting portion 16C of the transfer / transport unit cassette 16 described later.

On the image forming apparatus main body side, a supporting portion corresponding to the supporting means of the transfer / transport unit 13 is provided. That is, in FIG. 6, a transfer / transport unit cassette 16 that is hinged to the apparatus main body and can be opened and closed is provided at a position facing each photoconductor 1. The transfer / transport unit cassette 16 has a downward U-shaped locking portion 16A.
By attaching this locking portion 16A to the locking pin 17 located in the lower part of the main body of the apparatus in FIG. 6, it is possible to swing (tilt) in the opening / closing direction, and the opening angle is set by a restriction member (not shown). It is supposed to be regulated. That is, the transfer / conveyance unit cassette 16 has the locking pin 17
Between the first position, which is close to the photoconductor 1 so as to face the photoconductor 1, and the second position, which is separated from the photoconductor and where the transfer / transport unit 13 can be inserted and removed, as shown in FIG. It can be opened and closed.

On the upper portion of the transfer / transport unit cassette 16, there is provided an engaging hook 16B which can be engaged and disengaged on the apparatus main body side.
When it is closed, it can be engaged with the engagement portion P on the device side to maintain the closed position. On the side surface of the transfer / transport unit cassette 16, a U-shaped mounting portion 16C having an upward opening to which the guide rail 13B mounted on the side surface of the transfer / transport unit 13 can be attached / detached is provided.

The transfer / transport unit cassette 16 is provided with an opening on the upper surface in FIG. 6 to which the transfer / transport unit 13 can be attached / detached, and the light receiving portion 14 on the side of the inserted transfer / transport unit 13 is provided inside. A light emitting unit 18 which is the other side of the image position detecting sensor is provided at a position where the light emitting unit 18 can face. The light emitting unit 18 is the transfer / transport unit cassette 1
It is attached to the tip of a supporting screw 18A fixed to the 6 side so as to face the light receiving portion 14. In addition,
In FIG. 6, reference numeral H indicates a support portion of the drive mechanism of the belt roller 10A located on the drive side among the belt rollers, and reference numeral U indicates a side plate portion on the apparatus main body side.

In this embodiment, a structure for positioning members used for image position detection is provided. In other words, the configuration for detecting the image position is provided separately for both the transfer / transport unit 13 and the transfer / transport unit cassette 16 that are in the insertion / removal relationship, and both of them perform relative movement. , Is provided to maintain the positioning accuracy.

FIG. 2 is a perspective view showing the transfer / transport unit. In FIG. 2, the conveyance belt 10 used in the transfer / conveyance unit 13 is made of a light transmissive material.

An opening 131A is formed in a part of the cover 131 provided in the transfer / transport unit 13, and the transport belt 10 is exposed from the opening 131A. The cover 131 is attached to the side wall portion 132 of the transfer / transport unit 13,
A part of the positioning means 140 is provided on both sides of the opening in the side wall 132.

The positioning means 140 includes an engaging portion 141 provided on the transfer / transport unit 13 side and a transfer / transport unit cassette 16 (FIG. 6) which can be opened and closed on the apparatus main body side.
(See) and the engaging pin 142 provided in (see). The engaging portion 141 is composed of a hole formed in one of the side wall portions 132 located at both ends in the width direction of the transfer / transport cassette 13 and a groove formed in the other side portion.
An engaging pin 142 formed of a protrusion located on the transfer / conveyance unit cassette 16 side can be engaged with 1. As for the engaging portion 141, it is possible to use only a hole or a structure that does not shift when engaged like the hole.

The facing position of the engaging portion 141 and the engaging pin 142 is determined on the following premise. That is, the transfer / transport unit 13 is transferred to the transfer / transport unit cassette 16
The light emitting portion 18 which is mounted inside and is one of the optical members of the image position detecting sensor can face the light receiving portion 14 which is the other optical member of the image position detecting sensor located on the transfer / transport unit cassette 16 side. ing. In other words,
The optical members are positioned and formed in the vicinity of the installation positions of the optical members. As a result, the positional relationship between the optical members is regulated according to the state in which the engaging portion 141 and the engaging pin 142 engage with each other at the location that most affects the positional relationship between the optical members.

A support member 150 for the light receiving portion 14 is provided on the transfer / transport unit cassette 16 side having the light receiving portion 14 which is the other of the optical members. The support member 150 is
The conveyance belt 10 is configured by stacking plate members whose width direction corresponds to the longitudinal direction, and is configured by a support plate of the engagement pin 142 and a terminal plate for the light emitting unit 18 superimposed on the support plate.
Engaging pins 142 formed of protrusions are attached near both ends in the longitudinal direction of the support member 150, and the light emitting portion 18 is attached inside thereof.

The engaging pin 142 has a truncated cone shape and is easily aligned with the engaging portion 141. The mounting center position of the engagement pin 142 is aligned with the mounting center position of the light receiving portion 14 in the width direction corresponding to the direction perpendicular to the longitudinal direction of the support member 150. Such an attachment center position is set similarly in the engaging portion 141 and the light emitting portion 18 formed on the transfer / transport unit 13 side, and in the design drawing, the engaging portion 141 and the engaging pin are set. 1
The center line with 42 coincides.

A supporting pin 151 for supporting the supporting member 150 so that it can be moved back and forth toward the light emitting portion 18 is inserted. The support pin 151 has a stepped structure on the head located on the light emitting portion 18 side, and the end opposite to the head is fastened and held to the transfer / transport unit cassette 16 as shown in FIG.

The support pin 151 is inserted into the insertion hole 150 formed in the support member 150, but the insertion hole 1
50A is slightly larger than the outer diameter of the support pin 151. Accordingly, the support member 150 can be displaced around the outer periphery of the support pin 151 by utilizing the dimensional difference between the support pin 151 and the insertion hole 150A.

As shown in FIG. 3, the support pin 151 has
An elastic body 152 such as a coil spring is inserted between the back surface of the support member 150, that is, the surface opposite to the head of the support pin 151 and the inner surface of the transfer / transport unit cassette 16. The support member 150 is maintained in a state in which the support pin 151 is inserted and abuts against the head of the support pin 151 by the urging force of the elastic body 152, and further, a dimension between the insertion hole 150A and the outer diameter of the support pin 151. Support member 15 due to the difference
In the plane along the longitudinal direction of 0, it can be displaced in the front-back, left-right and combined directions thereof. In addition, in FIG. 2, a portion indicated by reference numeral 150B indicates a support hole for inserting and electrically connecting the pin terminal of the light receiving portion 14.

Since the present embodiment is constructed as described above,
The operation will be described as shown in FIGS. FIG. 3 shows a state in which the transfer / transport unit 13 is about to be mounted in the transfer / transport unit cassette 16. In this state, the transfer / transport unit cassette 16 is opened from the side plate U of the apparatus main body and positioned at the second position, and the guide rail 13B on the transfer / transport unit 13 side is mounted on the transfer / transport unit cassette 16 side. By being inserted into 16C, the transfer / transport unit 13 is mounted on the transfer / transport unit cassette 16 located on the apparatus main body side. As a result, when the transfer / transport unit 13 is attached to the transfer / transport unit cassette 16, the transfer / transport unit 13 is transferred.
The transfer / transport unit 13 can be positioned with respect to the transport unit cassette 16, and further, the transfer / transport unit 16 is closed to transfer / transfer unit cassette 1
The transfer / conveyance unit 16 is positioned with respect to the apparatus main body by engaging the engaging hook 16B located at the upper part of 6 with the apparatus main body side, so that the positioning between the cartridged apparatuses is optimized. Will be done.

On the other hand, as shown in FIG. 4, the transfer / conveyance unit 13 uses the guide rails 13B to transfer / convey unit 1.
6 is completely attached to the transfer / conveyance unit cassette 16 by abutting the end edge portion in the attachment portion 16C of 6,
The light emitting portion 18 and the light receiving portion 14 are aligned by engaging the engaging pin 142 with the engaging portion 141 provided in the positioning means 14 used for detecting the image position.

When the transfer / transport unit 13 is completely installed in the transfer / transport unit cassette 16, as shown in FIG. 5, the transfer / transport unit 16 uses the engaging pin 17 as an axial fulcrum to the casing side of the apparatus main body. Closed towards. As a result, in the transfer / transport unit 13, the transfer / transport unit cassette 16 has the engagement pin 1 depending on the shape of the mounting portion 16C.
7 is maintained as a shaft fulcrum and the state displaced from the second position to the first position is maintained.

As described above, when the transfer / transport unit 13 is replaced, the transfer / transport unit cassette 1
6 is opened and closed by using the engaging pin 17 as the pivot point, and
Since the transfer / conveyance unit 13 can be inserted / removed by tilting as shown in FIG. 7, the transfer / conveyance unit 13 can be replaced by a simple operation without the need to remove or attach the transfer / conveyance unit 13. Particularly, the transfer / transport unit 13 in the transfer / transport unit cassette 16 is exposed to the outside using the engaging pin 17, and the transfer / transport unit 13 in the tilted state is taken out only by pulling up as shown in FIG. As a result, unlike the case of pulling out in the horizontal direction, the space for pulling out can be reduced, and convenience can be obtained when securing a pulling out space in the peripheral portion of the image forming apparatus.

[0036]

According to the inventions of claims 1 and 4,
Since the supporting means can be displaced between the first position in which the transfer means is brought close to the image forming portion and the second position in which the transfer means is separated from the image forming portion, the operation for removing the transfer means from the apparatus main body is required. The transfer means can be attached and detached by a simple operation of only changing the position of the support means, and the labor for maintenance can be simplified. In particular, in claim 5, since the support means is pivotally supported by the housing of the apparatus main body so that the posture can be set to each of the above positions, the operation such as pulling out the transfer means from the housing becomes unnecessary, and the drawer is pulled out. It becomes possible to eliminate the sliding resistance and the structure at the time of.
Moreover, by defining the first and second positions respectively and optimizing the positioning between the devices that are individually brought into contact with and separated from each other, it is possible to prevent the occurrence of a defective image due to an error in the transfer position or the like. .

According to the invention described in claims 2, 3, and 5, the first engaging portion and the second engaging portion are provided, and the first engaging portion is inserted into the second engaging portion. By doing so, not only the positioning between them can be performed but also the state in which the transfer means can be displaced together with the support means can be set, so that the positional relationship with the main body of the apparatus on which these both means are supported is optimized and the transfer It is only necessary to engage and disengage the engaging portions without the need to remove or attach the transfer means when attaching or detaching the means. This makes it possible to simplify the labor required for work such as replacement of the transfer unit.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a color image forming apparatus which is an example of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a transfer / transfer used in the image forming apparatus shown in FIG.
It is a perspective view of a conveyance unit.

FIG. 3 is a diagram for explaining one aspect of a mounted state of the transfer / transport unit shown in FIG.

FIG. 4 is a diagram showing a state after the mounting of the transfer / transport unit shown in FIG. 2 is completed.

FIG. 5 is a diagram showing a state in which the transfer / transport unit with the transfer / transport unit attached is closed toward the apparatus main body.

FIG. 6 is a diagram for explaining a conventional example regarding a configuration of a transfer / conveyance unit equipped in an image forming apparatus and a mounting portion of the transfer / conveyance unit.

[Explanation of symbols] 1 photoconductor 10 Conveyor belt 13 Transfer / transport unit 13A terminal 13B guide rail 14 Light emitting part that forms one side of the sensor 15 lead wire 16 Transfer / transport unit cassette 16C mounting part

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Claims (5)

[Claims] 1. An apparatus main body having a plurality of image forming sections arranged side by side, and a plurality of image forming sections of the apparatus main body, which are provided so as to face each other, and images formed by the plurality of image forming sections can be sequentially transferred. Transfer unit, a first position provided in the apparatus main body for transferring the transfer unit in the vicinity of the image forming unit, and a second position for separating the transfer unit from the image forming unit. An image forming apparatus, comprising: a supporting unit that is rotatably supported by and that can set a position that allows the transfer unit to be attached and detached when the transfer unit is in the second position. . 2. The image forming apparatus according to claim 1, wherein the support unit supports the transfer unit by inserting a part of the transfer unit. 3. The image forming apparatus according to claim 1, wherein the transfer means is provided with a first engaging portion, and the supporting means is capable of inserting and removing the first engaging portion. The image forming method is characterized in that two engaging portions are provided, and the transfer means is supported by the supporting means by inserting the first engaging portion into the second engaging portion. apparatus. 4. The image forming apparatus according to claim 1, wherein the supporting means is pivotally supported by a casing of the apparatus main body and has the first position and the second position. An image forming apparatus characterized in that it is displaceable to. 5. The image forming apparatus according to claim 3, wherein the first engaging portion of the transfer means is provided on both side surfaces in the width direction corresponding to a direction perpendicular to the moving direction of the transfer means. An image forming apparatus characterized in that