JP4657088B2 - Development device - Google Patents

Description

  The present invention relates to a developing device, and more particularly to a developing device mounted on an image forming apparatus.

  Conventionally, an image forming apparatus configured to transfer a developer image formed on a photosensitive drum based on image data to a recording medium through a transfer process, when the apparatus is moved or moved, When the developing roller and the photosensitive drum collide with each other due to vibration generated during movement, there is a problem that the photosensitive drum is damaged.

  In view of this, in the image forming apparatus, the developing device provided with the developing roller and the apparatus main body are configured separately, and when the image forming apparatus is moved, the developing device is moved without being incorporated in the apparatus main body. The method is known.

  The developing device according to such a system is located at a position facing the photosensitive drum so that the photosensitive drum in the device main body and the developing roller of the developing device are opposed to each other when the developing device is mounted on the main body. An opening is provided through which the developing roller can be exposed.

  When the developing device is handled with the developing device detached from the apparatus main body, it is necessary to close the opening until the developing device is attached to the apparatus main body so that the toner does not leak and the developing roller is not damaged.

Therefore, as a conventional technique, for example, a cover member that covers the opening of the developing device mounted on the image forming apparatus is provided separately so as to protect the developing roll surface and prevent the toner from leaking. Is disclosed (see Patent Document 1).
JP 07-261550 A

  However, in the above conventional method, when packaging the developing device, separate parts such as a cushion member and a cover member for protecting the developing roller are required, and as the number of components increases, assembly and removal work increases. There is a problem that the work becomes complicated and the packaging cost and the like which are not directly related to the performance of the developing device are generated and expensive.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide an inexpensive developing device with a simple configuration that can simplify the packaging form without increasing the number of parts. And

The present invention for solving the above problems, a developer image formed on the photosensitive drum based on image data by a developer supplied by the developing roller to the image forming apparatus onto a recording medium through the transfer process A developing device used,
The developing roller is built in a casing that constitutes an exterior portion of the developing device,
The housing has an opening formed at a position where the developing roller and the photosensitive drum face each other, and a cover member that closes the opening is provided.
The cover member has an L-shaped cross section formed so that one end portion and the other end portion extend from a corner portion, and one end portion is in a thickness direction at a boundary portion with an opening edge of the housing The other end portion is formed separately from the housing, and the inside of the housing is sealed in a state of being overlapped with the bottom of the housing. Is configured as
The developing device according to claim 1, wherein the cover member is separated from the casing by separating the one end and separating the other end from the end of the casing .

In addition to the structure described in claim 1 , the developing device described in claim 2 is characterized in that the cover member is formed of the same material as that of the casing.

According to a third aspect of the present invention, in addition to the configuration described in the first or second aspect , the developing device includes a cover member holding structure that holds one end of the cover member on a part of the casing. It is what.

According to a fourth aspect of the present invention, in addition to the configuration described in the third aspect , the cover member holding structure includes an engagement portion formed at a free end of the cover member, and the cover of the housing. And a holding portion formed at an end portion corresponding to the free end portion of the member.

According to the first aspect of the present invention, it is used in an image forming apparatus that transfers a developer image formed on a photosensitive drum based on image data by a developer supplied from a developing roller to a recording medium through a transfer process. In the developing device, the developing roller is built in a casing constituting an exterior portion of the developing device, and an opening is formed in the casing at a position where the developing roller and the photosensitive drum face each other. A cover member for closing the opening is provided, and the cover member has an L-shaped cross section formed such that one end and the other end extend from a corner, and the one end is the casing. The boundary with the opening edge of the opening is cut away in the thickness direction so as to be separable and formed integrally with the housing, while the other end is formed separately from the housing and Seal the inside of the housing in a state where it overlaps the bottom. Be configured urchin, the cover member, by the separation of the one end and the other end was set to Hazuseru the cover member by spaced apart from an end portion of the housing from the housing, the number of parts Thus, the packaging form can be simplified without increasing the number, and an inexpensive developing device can be realized with a simple configuration.

  Further, according to the developing device of the present invention, the opening of the housing in which the developing roller is incorporated is normally closed with a cover member so that the surface of the developing roller is protected and foreign matter does not enter the developing device. It will be packed with. For example, at the time of shipment, the cover member is formed integrally with the housing of the developing device, and packing in a state of completely covering the opening is possible.

When the developing device is mounted on the image forming apparatus main body, the cover member, which is a part of the housing of the developing device, is cut along the notch line so that it can be easily used as the developing device. Can be installed. The cut cover member can be discarded as it is.
Further, at the boundary between the casing and the cover member, a notch is formed in the thickness direction of the casing, and the cover member can be separated from the casing along the notch, The cover member can be easily removed from the housing.

Further, it is possible in addition to the above common effect obtained by the invention described in claim 1, to obtain the following effects according to the invention described in the claims.

According to the second aspect of the present invention, since the cover member is formed of the same material as the casing, the casing and the cover member can be molded at the same time. It is possible to improve the performance.

According to the invention described in claim 3 , the cover member is provided with a cover member holding structure for holding one end portion of the cover member in a part of the housing, so that the cover member is in the housing during transportation or movement of the developing device. It becomes difficult to come off from the body and the opening can be reliably closed.

According to the invention described in claim 4 , the cover member holding structure includes an engagement portion formed at a free end portion of the cover member, and an end portion corresponding to the free end portion of the cover member of the housing. With the holding portion formed in the above, the opening portion can be reliably closed by holding the cover member on the housing with a simple structure without providing a separate locking mechanism.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an example of an embodiment for carrying out the invention, and is an explanatory diagram showing the overall configuration of a color image forming apparatus employing a developing device according to the present invention.

  In this embodiment, as shown in FIG. 1, color image formation is performed by transferring a developer image formed on a photosensitive drum 21 based on image data by a developer supplied by a developing roller 231 to a recording sheet through a transfer process. A developing device 23 used in the apparatus 1, which is configured to be detachable from the apparatus main body, and is used when the color image forming apparatus 1 is moved when the apparatus is carried in or moved. The developing device 23 is attached to the apparatus main body after the color image forming apparatus 1 is installed without being attached to the main body.

  As shown in FIG. 1, the color image forming apparatus 1 to which the developing device 23 according to this embodiment is mounted has a developer (hereinafter referred to as toner) that matches each hue according to the color-separated image information. The photosensitive drum 21 (21 a, 21 b, 21 c, 21 d) on which a developer image (hereinafter referred to as a toner image) is formed, and development for supplying the developer to the surface of the photosensitive drum 21. And a plurality of process printing units (image forming means) 20 (20a, 20b, 20c, 20d) provided with the apparatus 23, and further, laser light (on each photosensitive drum 21 for each color based on image information ( A transfer belt unit 30 including an endless transfer belt 31 that conveys the supplied recording paper, and a heating roller 2. The toner image transferred to the recording sheet by the a and a pressure roller 27b and a fixing unit 27 for thermally fixing.

First, the overall configuration of the color image forming apparatus 1 will be described.
A color image forming apparatus 1 according to the present embodiment is a so-called digital color printer, which color-separates image information, forms an image for each hue, and outputs a color image, as shown in FIG. In general, the image forming unit 108 and the sheet feeding unit 109 are configured to record a multicolor image or a single color image on the basis of a print job from an information processing apparatus (not shown) such as a personal computer connected to the outside. It is formed on top.

  The image forming unit 108 uses an electrophotographic method to form a multicolor image using each color of yellow (Y), magenta (M), cyan (C), and black (BK). The unit 10, the process printing unit 20, the fixing unit 27, a transfer belt unit 30 as a transfer means including a transfer belt 31, and a transfer belt cleaning unit 37 are configured.

  The schematic configuration of the image forming unit 108 is that a fixing unit 27 is arranged on one end side of the casing 1a of the color image forming apparatus 1, and is arranged in parallel with the fixing unit 27 and extends from the fixing unit 27 to the other end side. 30, the process printing unit 20 is disposed above the transfer belt unit 30, and the exposure unit 10 is disposed above the photosensitive drum 21 constituting the process printing unit 20.

  A transfer belt cleaning unit 37 is provided below the transfer belt unit 30. Further, a paper discharge tray 43 is formed above the image forming unit 108. A paper feeding unit 109 is configured below the image forming unit 108.

  In the present embodiment, as the process printing unit 20, four process printing units 20a, 20b, 20c, and 20d corresponding to respective colors in the order of yellow (Y), magenta (M), cyan (C), and black (BK) are provided. They are sequentially provided along the transfer belt 31.

  The process print unit 20d having the hue transferred last in the toner image transferred onto the transfer belt 31, that is, the process print unit 20d having the hue closest to the fixing unit 27 has a black hue. A toner is provided and a black toner image is finally formed on the transfer belt 31.

  These process printing units 20a, 20b, 20c, and 20d are arranged in parallel in a substantially horizontal direction (left and right direction in the drawing) in the casing 1a, and photoconductive drums 21a, 21b, which are image carriers for each color. 21c, 21d, chargers 22a, 22b, 22c, 22d for charging the photosensitive drums 21a, 21b, 21c, 21d, developing devices 23a, 23b, 23c, 23d, cleaner units 24a, 24b, 24c, 24d, etc., respectively. I have.

  Here, the symbols a, b, c, and d attached to the components corresponding to the respective colors correspond to the respective colors of yellow (Y), magenta (M), cyan (C), and black (BK). However, in the following description, the components provided for each color are collectively shown in the photosensitive drum 21 except for the case where the components corresponding to a specific color are specified. , Charger 22, developing device 23, and cleaner unit 24.

  The photosensitive drum 21 is disposed such that a part of the outer peripheral surface thereof is in contact with the surface of the transfer belt 31, and the charger 22, the developing device 23, and the cleaner unit as an electric field generating unit along the outer peripheral surface of the drum. 24 are arranged close to each other.

  As the charger 22, a corona wire charger type charger is used, and is arranged close to the outer peripheral surface of the photosensitive drum 21 on the substantially opposite side to the position where the transfer belt unit 30 is arranged with the photosensitive drum 21 interposed therebetween. . In the present embodiment, a corona wire charger type charger is used as the charger 22. However, instead of the corona wire charger type charger, a fur brush type charger, a magnetic brush type charger, a roller type charger, a saw tooth Any type charger, ion generating charging device, or the like can be used without particular limitation as long as it can impart desired chargeability to the photosensitive drum.

  The developing device 23 stores toner of each color of yellow (Y), magenta (M), cyan (C), and black (BK) for each developing device 23 (23a to 23d). It is arranged downstream of the charger 22 in the rotational direction (the direction of arrow A in the figure).

  In the developing devices 23a to 23d, developing rollers 231a to 231d are arranged to face the photosensitive drums 21a to 21d, respectively, and toners of various colors are formed on the electrostatic latent images formed on the outer peripheral surfaces of the photosensitive drums 21a to 21d, respectively. Is supplied and visualized.

  The cleaner unit 24 is disposed on the upstream side of the charger 22 in the rotation direction of the photosensitive drum. In addition, the cleaner unit 24 includes a cleaning blade 241, and the cleaning blade 241 is disposed in contact with the outer peripheral surface of the photoconductive drum 21 to scrape and collect residual toner on the photoconductive drum 21. Has been. Although the cleaning blade 241 is used in this embodiment, the present invention is not particularly limited to these configurations, and one or more cleaning blades may be used, or a fur brush or a magnetic brush may be used alone. A cleaning blade, a fur brush, and a magnetic brush may be used in combination. Any device configured to scrape and collect residual toner on the photosensitive drum 21 can be used.

  The exposure unit 10 mainly includes a case 10a formed in a box shape, a laser scanning unit (LSU) 11 including a laser irradiation unit (not shown) and a polygon mirror disposed therein, and a laser beam for each color. The reflecting mirrors 13a, 13b, and 13c are configured to reflect.

  The laser light emitted from the laser irradiation unit of the laser scanning unit 11 is color-separated by a polygon mirror and an fθ lens (not shown), and then reflected by the reflection mirrors 13a to 13c. 21b, 21c, and 21d are irradiated.

  The laser scanning unit 11 may be configured to use a writing head in which light emitting elements such as EL (Electro Luminescence) and LED (Light Emitting Diode) are arranged in an array instead of the laser irradiation unit, or a light source The liquid crystal shutter may be used, and any means capable of forming an electrostatic latent image on the photosensitive drum 21 can be used.

  As shown in FIG. 1, the transfer belt unit 30 mainly includes a transfer belt 31, a transfer belt driving roller 32, a transfer belt driven roller 33, intermediate transfer rollers 35a, 35b, 35c, and 35d, and a conveying roller 36. ing.

  In the following description, the intermediate transfer rollers 35a, 35b, 35c, and 35d are collectively referred to as the intermediate transfer roller 35 when used.

  The transfer belt 31 is stretched by a transfer belt driving roller 32, a transfer belt driven roller 33, and an intermediate transfer roller 35 so that the surface thereof is in contact with a part of the outer peripheral surface below the photosensitive drum 21, and the transfer belt 31 The recording sheet is conveyed while being pressed against the photosensitive drum 21 by moving in the sub-scanning direction (the direction of arrow B in the figure) by the driving force of the driving roller 32.

  The transfer belt driving roller 32 is disposed in the vicinity of the fixing unit 27, drives the transfer belt 31 to convey the transfer belt 31, and also has a photosensitive drum in a state where the transfer belt 31 and the recording paper are overlapped. 21 and the intermediate transfer roller 35 so as to convey the recording paper while being pressed against each other.

  The transfer belt driven roller 33 is disposed on the other end side of the housing 1a, and the transfer belt 31 and the transfer belt driving roller 32 are laid substantially horizontally from the fixing unit 27 side to the other end side of the housing 1a. When the size in the width direction of the color image forming apparatus 1 in FIG. 1 is to be reduced, or in order to save space in the so-called width direction, the transfer belt 31 is moved from the fixing unit 27 side together with the transfer belt drive roller 32. It is also possible to have one of the other sides of the housing 1a inclined, and appropriately set the various suitable arrangements, sizes, etc., such as the photoreceptor, development, laser irradiation unit, fixing, etc. It doesn't matter.

  The intermediate transfer roller 35 is disposed in the inner space of the transfer belt 31 that is wound from the transfer belt driving roller 32 to the transfer belt driven roller 33. The transfer belt 31 is disposed at a position shifted to the downstream side in the moving direction, presses the inner surface of the transfer belt 31, and the outer surface of the transfer belt 31 winds a part of the outer peripheral surface of the photosensitive drum 21. You may provide so that a predetermined | prescribed nip amount may be obtained.

  The intermediate transfer roller 35 includes a metal (for example, stainless steel) shaft having a diameter of 8 to 10 mm, and the outer peripheral surface of the metal shaft is coated with a conductive elastic material such as EPDM or urethane foam. It is not necessary to limit to these elastic materials.

  The intermediate transfer roller 35 configured in this manner is used to transfer a toner image formed on the photosensitive drum 21 onto a recording sheet conveyed by the transfer belt 31, that is, a high voltage transfer bias, that is, a toner charging polarity ( A high voltage having a polarity (+) opposite to that of (−) is applied, and a high voltage is uniformly applied to the transfer belt 31 by an elastic material.

  A toner image (electrostatic image) visualized according to each hue on each of the above-described photosensitive drums 21 is laminated on a recording sheet conveyed by the transfer belt 31, and becomes image information input to the apparatus.

  A registration roller 26 is provided upstream of the transfer belt driven roller 33 in the paper conveyance direction. The registration roller 26 is configured to align the front end of the recording paper supplied from the paper supply unit 109 with the front end of the toner image on the photoconductive drum 21 and convey it to the photoconductive drum 21 side.

  Further, as described above, the toner adhering to the transfer belt 31 due to the contact with the photosensitive drum 21 causes the toner to be mixed in the next process, so that the toner is removed and collected by the transfer belt cleaning unit 37. Is set.

  The transfer belt cleaning unit 37 is provided below the transfer belt 31 (on the side opposite to the photosensitive drum) and is disposed so as to contact (or slide) the transfer belt 31, and the cleaning blade 37a. A box-shaped toner collecting portion 37b for temporarily storing toner (waste toner) scraped off the residual toner on the transfer belt 31 is provided, and the residual toner on the transfer belt 31 is scraped and collected.

  As shown in FIG. 1, the fixing unit 27 includes a pair of fixing rollers 271 configured by a heating roller 27 a and a pressure roller 27 b, and a conveyance roller 27 c on the downstream side of the fixing roller 271 in the sheet conveyance direction. .

  Above the fixing unit 27, a discharge roller 28 is provided on the conveyance roller 27 c, and the recording sheet conveyed from the conveyance roller 27 c is discharged onto the discharge tray 43 by the discharge roller 28. Has been.

  The fixing of the toner image by the fixing unit 27 is controlled by controlling heating means (not shown) such as a heater lamp provided inside or close to the heating roller 27a based on a detection value of a temperature detector (not shown). The heating roller 27a is maintained at a predetermined temperature (fixing temperature), and the recording paper on which the toner image has been transferred is heated and pressed while being rotated and conveyed by being sandwiched between the heating roller 27a and the pressure roller 27b. The toner image is thermally fixed.

  In this embodiment, the heating roller 27a and the pressure roller 27b, which are heating means such as a heater lamp, are used. However, an induction heating method may be used or they may be used in combination. Further, any means may be used as long as it is an appropriate method capable of uniformly heat-fixing the toner image on the recording paper without disturbing the toner image without using a roller.

  Further, adjacent to the fixing unit 27, the recording paper transport paths S2 and S3 are configured from the rear to the upper side of the fixing unit 27, and are discharged by a paper discharge roller 28 provided downstream of the recording paper transport path S3 in the paper transport direction. The recording paper is discharged onto the paper discharge tray 43. Note that a paper discharge switching mechanism 44 provided in the recording paper conveyance path S2 can discharge paper to the second paper discharge tray 45.

  The paper feeding unit 109 includes a paper feeding cassette 42 for storing recording paper used for image formation, and the recording paper is supplied from the paper feeding cassette 42 to the image forming unit 108 one by one.

  The paper feed cassette 42 is provided below the image forming unit 108 and the exposure unit 10 in the housing 1a, and accommodates a large amount of recording paper having a size defined by the specifications of the apparatus or a size predetermined by the user. It is possible.

  A pickup roller 42a is provided on one end portion (right end portion in the figure) of the paper feed cassette 42, and a conveyance roller 42b is provided downstream of the pickup roller 42a in the recording sheet conveyance direction (arrow C direction in the figure). , 42c are provided.

  The pickup roller 42a comes into contact with the surface of one end of the recording paper at the top of the recording paper set in the paper feeding cassette 42, and reliably picks up and conveys the paper one by one by the frictional resistance of the roller. Yes.

  The conveying roller 42b conveys the recording sheet fed from the pickup roller 42a to the conveying roller 42c along the recording sheet conveying path S1 formed on one end side in the housing 1a, and the conveying roller 42c moves upward to the image. It is conveyed to the forming unit 108.

Here, image output by the color image forming apparatus 1 of the present embodiment will be described.
The color image forming apparatus 1 is configured to transfer the toner image on the photosensitive drum 21 onto the recording paper supplied from the paper supply unit 109 onto the recording paper.

First, the charger 22 uniformly charges the outer peripheral surface of the photosensitive drum 21 to a predetermined potential.
By irradiating the charged photosensitive drum 21 with laser light from the exposure unit 10, an electrostatic latent image for each color is generated on the photosensitive drum 21 for each color.

  Next, toner is supplied from the developing devices 23a to 23d to the outer peripheral surfaces of the photosensitive drums 21a to 21d, and the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 21 is visualized as a toner image by the toner. It becomes.

  Then, the toner images generated on the photosensitive drums 21 a to 21 d are transferred to the recording paper conveyed by the transfer belt 31. The transfer of the toner image from the photosensitive drum 21 to the recording paper is performed by applying a high voltage to the intermediate transfer roller 35 disposed in contact with the back side of the transfer belt 31.

  By applying a high voltage with a polarity (+) opposite to the toner charging polarity (-) to the intermediate transfer roller 35, the transfer belt 31 is uniformly applied with a high voltage by the intermediate transfer roller 35 and has a reverse polarity. (+). As a result, the toner image having the charging polarity (−) on the photosensitive drum 21 is transferred onto the recording paper when the photosensitive drum 21 is in rotational contact with the recording paper on the transfer belt 31.

  The toner images of the respective colors formed on the respective photosensitive drums 21a to 21d are yellow (Y), magenta (M), and cyan (C) as the recording paper moves and contacts with the respective photosensitive drums 21a to 21d. ) And black (BK) in this order, and a color toner image is formed on the recording paper.

  In this manner, the electrostatic latent images visualized with toner on the photosensitive drums 21a to 21d for each color are stacked on the recording paper, and the printing image is reproduced on the recording paper as a multicolor toner image. Is done.

  Since the toner adhering to the transfer belt 31 due to contact with the photosensitive drum 21 causes toner color mixing in the next step, it is removed and collected by the transfer belt cleaning unit 37.

Next, the recording paper supply operation by the paper supply unit 109 will be described.
When the recording paper stored in the paper feed cassette 42 is used, the recording paper is separated and fed one by one from the paper feed cassette 42 by the pickup roller 42a, and image formation is performed along the recording paper transport path S1 by the transport roller 42b. To the unit 108.

  The recording sheet conveyed from the paper feed cassette 42 is conveyed to the photosensitive drum 21 side by the registration roller 26 at a timing when the leading end of the recording sheet and the leading end of the toner image on the photosensitive drum 21 are aligned. The toner image on 21 is transferred onto the recording paper.

  The recording paper onto which the toner image on the photosensitive drum 21 is sequentially transferred reaches the fixing unit 27, and the toner image is thermally fixed on the recording paper by the heating roller 27 a and the pressure roller 27 b in the fixing unit 27.

The recording sheet that has passed through the fixing unit 27 passes through the recording sheet conveyance paths S2 and S3 and is discharged face-down onto the sheet discharge tray 43 by the sheet discharge roller 28.
In this manner, the toner image is transferred to the recording paper and an output operation is performed.

Next, the configuration of the developing device 23 according to the present invention will be described in detail with reference to the drawings.
2A is a partial cross-sectional view showing the structure of the cover member of the developing device constituting the color image forming apparatus of the present embodiment, and FIG. 2B shows the operation of removing the cover member from the housing of the developing device. (C) is a partial cross-sectional view showing a state where a cover member of the casing is removed.

  As shown in FIG. 1, the developing device 23 has a developing roller 231 disposed on the bottom side inside a housing 232 that forms an exterior portion, and the developing roller 231 is in contact with or close to the photosensitive drum 21. It is attached to the main body of the apparatus in the state where

  As shown in FIG. 2A, the housing 232 has a box shape, and the cover member 233 is disposed at a position where the developing roller 231 and the photosensitive drum 21 face each other with the developing device 23 mounted on the apparatus main body. It is formed integrally with the housing 232, and an opening 234 is formed when the cover member 233 is removed.

  The opening 234 is formed to be long in the width direction of the housing 232 along the axial center direction of the developing roller 231 so that at least the developing roller 231 can face and contact the photosensitive drum 21.

  The cover member 233 is formed by integral molding with the same material as the housing 232, and a boundary portion 232 a between the housing 232 and the cover member 233 that is one end edge of the opening 234 that is long in the width direction of the housing 232 includes: A substantially V-shaped notch 235 is formed in the width direction of the housing 232 so as to extend in the thickness direction of the housing 232.

The cutout 235 may have a thickness that allows the operator to easily separate the cover member 233 from the housing 232 along the cutout 235 with respect to the housing 232.
The cut depth of the notch 235 is determined as appropriate depending on the size of the opening 234 and the material of the housing 232.

  As shown in FIG. 2A, the outer peripheral edge other than the boundary portion 232 a of the cover member 233 is formed separately from the housing 232, and is in contact with or overlapping with the end of the housing 232. Thus, the inside of the housing 232 is sealed.

  As an example, the cover member 233 has an L-shaped cross section, and one end 233 a is formed integrally with the housing 232, while the other end 233 b is formed separately from the housing 232. The inside of the housing 232 is hermetically sealed in a state of being overlapped with the end of the bottom 232b of the housing 232.

  The bottom portion 232b of the housing 232 and the other end portion 233b of the cover member 233 may be simply combined in close contact with each other, or a part thereof is weakly heat-sealed or weakened by an adhesive or an adhesive member. It may be in an adhesive state.

Next, functions and effects of the developing device 23 will be described.
When the developing device 23 is attached to the color image forming apparatus 1, the cover member 233 is removed from the housing 232 of the developing device 23 so that the developing roller 231 inside the housing 232 is exposed, and then a predetermined unit of the apparatus main body is exposed. The developing device 23 is mounted at the position.

  When removing the cover member 233 from the housing 232, the other end 233b of the cover member 233 is separated from the bottom 232b of the housing 232, and the boundary 232a between the housing 232 and the cover member 233 is used as a fulcrum. Rotate.

  Since the boundary portion 232a integrally forms the casing 232 and the cover member 233 in a thin state by the notch portion 235, the boundary portion 232a can be easily cut by rotating the cover member 233 several times.

The cover member 233 that has been cut and separated from the housing 232 is removed, and the developing roller 231 is exposed from the opening 234 that is opened, and the developing device 23 is attached to the apparatus main body.
The cover member 233 separated from the housing 232 can be discarded as it is.

  In this manner, the cover member 233 can be separated from the housing 232 with a simple operation, and the developing device 23 can be easily assembled to the apparatus main body.

  Since it comprised as mentioned above, according to this embodiment, since the housing | casing 232 and the cover member 233 were formed integrally, a packing form can be simplified without increasing a number of parts, and easy An inexpensive developing device can be realized with the configuration.

  Further, according to the present embodiment, since the housing 232 and the cover member 233 are integrally formed, the developing roller with the opening 234 of the housing 232 in which the developing roller 231 is built closed by the cover member 233. It is possible to protect the surface and prevent foreign matter from entering the developing device 23, and packaging in a state of completely covering the opening 234 is possible at the time of shipment.

  In the present embodiment, one end of the cover member 233 is formed integrally with the housing 232, and the inside of the housing 232 is sealed with the other end except the one end simply abutting or overlapping. However, the present invention is not limited to the configuration in which the opening 234 is closed by the cover member, and the opening 234 may be closed by another configuration.

Hereinafter, modifications of the developing device 23 according to the above-described embodiment will be described in detail with reference to the drawings.
FIG. 3A is a partial cross-sectional view showing a configuration of a cover member of a modification of the developing device that constitutes the color image forming apparatus of the present embodiment, and FIG. 3B is a view of removing the cover member from the housing of the developing device. (C) is a partial cross-sectional view showing a state where a cover member of the casing is removed.
The image forming apparatus and the developing apparatus (not shown) in the modification have the same configuration as the color image forming apparatus 1 and the developing apparatus 23 described above, and the basic configuration and operation are the same as those in the above-described embodiment. Therefore, the description is omitted, and only different configurations are described.

  The developing device 223 has a developing roller 331 disposed on the bottom side inside the housing 332 that forms the exterior portion, and the developing roller 331 faces the photosensitive drum 21 with the developing roller 331 facing or approaching the photosensitive drum 21. Mounted (see FIG. 1).

  As shown in FIG. 3A, the housing 332 has a box shape, and the cover member 333 is located at a position where the developing roller 331 and the photosensitive drum 21 face each other when the developing device 223 is mounted on the apparatus main body. Is formed integrally with the housing 332, and an opening 334 is formed when the cover member 333 is removed.

  The opening 334 is formed to be long in the width direction of the housing 332 along the axial direction of the developing roller 231 so that at least the developing roller 331 can contact and contact the photosensitive drum 21.

  The cover member 333 is formed by integral molding with the same material as the housing 332, and a boundary 332 a between the housing 332 and the cover member 333 serving as one end edge of the opening 334 that is long in the width direction of the housing 332 includes A substantially V-shaped cutout 335 is formed in the width direction of the housing 332 so as to face in the thickness direction of the housing 232.

The notch 335 may have a thickness that allows the operator to easily separate the cover member 333 from the housing 332 along the notch 335 with respect to the housing 332.
Note that the cut depth of the notch 335 is appropriately determined depending on the size of the opening 334 and the material of the housing 332.

  The outer peripheral edge other than the boundary portion 232a of the cover member 333 is formed separately from the housing 332 so that the inside of the housing 332 is sealed in contact with or overlapping with the end of the housing 332. It has become.

  As shown in FIG. 3A, the cover member 333 has an L-shaped cross section, and one end 333 a is formed integrally with the housing 332, while the other end 333 b is separated from the housing 332. And the inside of the housing 332 is hermetically sealed with the end portion of the bottom 332b of the housing 332 overlapped.

  The other end portion 333b of the cover member 333 is formed with an engaging portion 333c projecting in a convex shape, and the bottom portion 332b of the housing 332 corresponds to the engaging portion 333c of the cover member 333. A holding portion 332c that is recessed in a concave shape for holding 333c is formed.

  A cover member holding portion structure 340 including a convex engaging portion 333 c and a concave holding portion 332 c is provided on the bottom portion 332 b of the housing 332. The configuration of the cover member holding portion structure 340 may be a configuration in which the concave and convex shapes of the engaging portion 333c and the holding portion 332c are reversed, and the engaging shape is limited. It is not a thing.

  With the configuration as described above, according to the developing device 223 of the present embodiment, the same operation and effect as the above-described embodiment can be achieved, and the engaging portion between the holding portion 332c of the housing 332 and the cover member 333 can be obtained. By forming the cover member holding part structure 340 including the 333c, the cover member 333 can be securely fixed to the housing 332 without providing a separate lock mechanism.

Next, a modified example in which the image forming apparatus in the above-described embodiment is developed into a composite apparatus will be described in detail with reference to the drawings.
FIG. 4 is another example of the embodiment for carrying out the invention, and is an explanatory diagram showing the overall configuration of a color image forming apparatus employing the developing device according to the present invention, and FIG. 5 shows the configuration of the color image forming apparatus. It is sectional drawing shown.

  In the present embodiment, as shown in FIG. 5, an image forming apparatus main body 210 having the same configuration as that of the color image forming apparatus 1 according to the above-described embodiment is added to a document (image) reading device 250, a paper feeding desk device 290, and the like. Is a color image forming apparatus 201 that supports high-speed mass printing at a high speed.

  In the color image forming apparatus 201 according to the present embodiment, the same components as those of the color image forming apparatus 1 described above are denoted by the same reference numerals, and the description thereof is omitted. The description is omitted by referring to the description of the embodiments and the drawings.

  The document reading device 250 is disposed above the image forming apparatus main body 210, and includes a document placing table 260, a scanner unit 270, an automatic document processing device 280, and the like. By mounting the automatic document processing device 280, it is possible to read both sides of a document and to perform automatic continuous reading processing of a plurality of documents.

  The document placement table 260 is disposed above the image forming apparatus main body 210 and has a transparent glass 262 on which the document is placed. Below the document placement table 260, a document for reading image information of the document. A scanner unit 270 serving as a reading unit is arranged.

  As shown in FIG. 5, the scanner unit 270 includes a first scanning unit 274 and a second scanning unit 275 that are disposed below the document placing table 260 and reciprocally move in parallel, an optical lens body 276, and photoelectric conversion. The document image reading unit is provided with an element (CCD) 277. In FIG. 5, the optical path of the scanner unit 270 is indicated by a one-dot chain line.

  The first scanning unit 274 has an exposure lamp 274A, a reflector 274B that exposes the light from the exposure lamp 274A on the surface of the original image, and a reflected light image from the original that is exposed and reflected through the reflector 274B. And a first mirror 274C for guiding in the direction of, and is controlled to reciprocate in parallel at a predetermined scanning speed while maintaining a certain distance from the lower surface of the document table 260. .

  The second scanning unit 275 includes a second mirror 275A and a third mirror for guiding the reflected light image from the document guided by the first mirror 274C of the first scanning unit 274 further in a predetermined direction. The mirror 275B of the first scanning unit 274 is reciprocally controlled in parallel while maintaining a constant speed relationship with the first scanning unit 274.

  The optical lens body 276 is disposed on the optical path of the reflected light of the document image guided by the third mirror 275B of the second scanning unit 275, and forms the optical image on the photoelectric conversion element 277.

  A photoelectric conversion element (for example, a CCD (Charge Coupled Device)) 277 creates original image information (original image data) by reading an optical image of an original image formed by the optical lens body 276 and photoelectrically converting it into an electrical signal. The document image information is output to the image processing unit 257.

  The image processing unit 257 performs image processing on the document image information output from the photoelectric conversion element 277 to print image information (print image data) whose resolution, density, and the like are suitable for printing. The image information for printing after image processing is transferred to an image data input unit of a laser scanning unit (LSU) 11.

  The laser scanning unit 11 irradiates the surface of the photosensitive drum 21 constituting the image forming unit (image forming process) 108 with laser light corresponding to the printing image information output from the image processing unit 257. Each drive unit is controlled based on a signal from the control unit 258, and an electrostatic latent image of image information for printing is written and formed on the photosensitive drum 21.

  The automatic document processing device 280 is arranged above the document placing table 260, and integrally includes a document pressing unit (document pressing cover) 281 including a double-sided document automatic reading device (R-SPF) using a document moving method. It is mounted on the table 260 so as to be openable and closable.

  The automatic document processor 280 has a document tray 282 on which documents are placed. When a plurality of documents are read continuously, the document placed on the document tray 282 is placed on a document pickup roller 283. Then, the original is introduced into the original conveyance path Sa1 via the original driving roller 284 and guided and conveyed upstream of the registration roller (PS roller) 285.

  An upstream side of the PS roller 285 is provided with a document insertion sensor (not shown) so that the document size of the document can be detected. The document insertion sensor detects the leading edge and the trailing edge of the document. The document is controlled to be conveyed toward the document table 260 while the conveyance timing is set based on the signal.

  In this case, the first scanning unit 274 of the scanner unit 270 is controlled to move so as to stand by and be positioned below the portion where the document is read.

  As the document conveyed on the document placing table 260 moves, the first image reading surface on one side is scanned by the first scanning unit 274 of the scanner unit 270. Other image forming processes such as reading by the photoelectric conversion element 277, image processing of image information, and printing are the same as described above.

  Then, the document after image reading on the document table 260 is conveyed to the document discharge roller 288 side of the document discharge path 287 via the conveyance belt 286. When only one-side reading is performed, the document is read on the document discharge tray 280a. The paper is discharged.

  When performing double-sided original reading, the original placed on the original placement table 260 is switched back by driving the conveyance belt 286 in the reverse direction by switching control of the original changeover gate 289, and the original is returned again. The original image on the image reading surface on the back side of the original is read.

  On the front side of the automatic document processor 280, there are operation switches 280b for the user to set the image forming conditions such as the paper type of the recording paper (paper thickness, paper thickness, etc.), the number of printed sheets, the magnification, and the density. It is arranged.

  The paper feeding desk device 290 is provided with a plurality of paper feeding cassettes 291 that are stacked in the vertical direction. Each paper feed cassette 291 can accommodate a plurality of recording papers of different sizes. Note that the paper feed cassette 291 may contain recording paper of the same size.

  A pickup roller 42a is provided on one end portion (right end portion in the figure) of the paper feed cassette 291 in the same manner as the structure of the paper feed cassette 42 described above, and the recording paper transport direction (see FIG. A conveyance roller 42b is provided on the downstream side (in the direction of arrow C), and a conveyance roller 292 is further provided on the downstream side.

  The pickup roller 42a comes into contact with the surface of one end portion of the recording paper at the top of the recording paper set in the paper feeding cassette 291, and reliably picks up and conveys the paper one by one by the frictional resistance of the roller. Yes.

  The conveying roller 42b is configured to convey the recording sheet fed from the pickup roller 42a upward along a recording sheet conveying path S5 formed on one end side in the housing 1a.

  The conveyance roller 292 is provided downstream of the recording sheet conveyance path S5 in the recording sheet conveyance direction, and conveys the recording sheet to the recording sheet conveyance path S4 formed inside the image forming apparatus main body 210.

  With the configuration as described above, according to the present embodiment, it is possible to realize a color image forming apparatus that exhibits the same operations and effects as those of the above-described embodiments and examples, and that supports high-speed mass printing.

  The developing device of the present invention is not limited to the above-described embodiments and examples, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

1 is an explanatory diagram illustrating an overall configuration of a color image forming apparatus according to an embodiment in which a developing device according to the present invention is employed. (A) is a partial cross-sectional view showing a configuration of a cover member of the developing device, (b) is a partial cross-sectional view showing an operation of removing the cover member from the housing of the developing device, and (c) is a cover of the housing. It is a fragmentary sectional view which shows the state which removed the member. (A) is a partial cross-sectional view showing the configuration of a cover member of a modification of the developing device, (b) is a partial cross-sectional view showing an operation of removing the cover member from the housing of the developing device, and (c) is the housing. It is a fragmentary sectional view which shows the state which removed the cover member of the body. It is explanatory drawing which shows the whole structure of the modification of the color image forming apparatus by which the developing device which concerns on this invention was employ | adopted. It is sectional drawing which shows the structure of the said color image forming apparatus.

Explanation of symbols

1,201 Color image forming apparatus 20, 20a, 20b, 20c, 20d Process printing unit 21, 21a, 21b, 21c, 21d Photosensitive drum 23, 23a, 23b, 23c, 23d, 223 Developing device 210 Image forming apparatus main body 231 , 331 Developing roller 232, 332 Housing 232a, 332a Boundary part 232b, 332b Bottom part 233, 333 Cover member 233a, 333a One end part 233b, 333b Other end part 234, 334 Open part 235, 335 Notch part 332c Holding part 333c Engagement Part 340 cover member holding part structure

Claims (4)

The developer image formed on the photosensitive drum based on image data by a developer supplied by the developing roller, a developing device used in an image forming apparatus onto a recording medium through the transfer process,
The developing roller is built in a casing that constitutes an exterior portion of the developing device,
The housing has an opening formed at a position where the developing roller and the photosensitive drum face each other, and a cover member that closes the opening is provided.
The cover member has an L-shaped cross section formed so that one end portion and the other end portion extend from a corner portion, and one end portion is in a thickness direction at a boundary portion with an opening edge of the housing The other end portion is formed separately from the housing, and the inside of the housing is sealed in a state of being overlapped with the bottom of the housing. Is configured as
The developing device according to claim 1, wherein the cover member is separated from the casing by separating the one end and separating the other end from the end of the casing . The developing device according to claim 1 , wherein the cover member is formed of the same material as the housing. The developing device according to claim 1 , further comprising a cover member holding structure that holds the other end portion of the cover member on a bottom portion of the casing. The cover member holding structure includes an engaging portion formed at a free end portion of the cover member and a holding portion formed at an end portion of the housing corresponding to the free end portion of the cover member. The developing device according to claim 3 , wherein:

Images