JP3877433B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a printer.
[0002]
[Prior art]
Generally, in a paper feeding device of an image forming apparatus such as a copying machine or a printer, a paper feeding roller that feeds paper gradually deteriorates due to wear or dirt. Therefore, in most image forming apparatuses, the paper feed roller is changed several times before the end of the life of the apparatus itself. For this reason, it is desirable that the replacement of the paper feed roller be simple.
[0003]
Conventionally, as a simpler replacement of a paper feed roller, for example, as disclosed in JP-A-6-144606, in a manual paper feeder, the shaft of the paper feed roller is integrated with the paper feed roller. The paper feed roller shaft and the drive shaft for transmitting the rotational force to the paper feed roller are divided, and both shafts are connected by a slidable shaft joint, and the shaft joint is slid to take out the paper feed roller. The technology is known.
[0004]
The above-described technique is a technique for a manual sheet feeding device, and the manual sheet feeding device is provided near the exterior surface of the apparatus due to its configuration and can be easily seen and handled from the outside. The exchange was not so difficult.
[0005]
[Problems to be solved by the invention]
However, in a paper feeding device that takes out paper from the paper feeding cassette, the paper feeding roller is generally provided below and near the center of the main body and is difficult to see and handle from the outside. There is a problem that exchange is difficult.
[0006]
SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus in which a paper feed roller can be easily replaced.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided an image forming unit in which a unit including at least one of a photoreceptor, a developing device, an exposure device, and the like can be attached to and detached from the main body, a paper feed cassette for loading paper, and the paper supply. A paper feed roller for feeding paper on a paper cassette to the image forming unit, a drive shaft connected to one end of a roller shaft of the paper feed roller and slidable in the axial direction, and the other end of the roller shaft are fitted. An image forming apparatus comprising: a fitting portion to be joined; a guide member that slides the drive shaft in an axial direction; and a structure that supports the image forming portion, the paper feed roller, and the drive shaft. When the guide member is slid in the direction away from the fitting portion, the paper feed roller slides together with the guide member, and the fitting between the other end of the roller shaft and the fitting portion is released. It is characterized by that.
[0008]
According to the first aspect of the present invention, when replacing the paper feed roller, first, the unit located above the paper feed roller is detached from the main body. In this way, a fixed space is formed above the sheet feed roller, the sheet feed roller can be visually confirmed from the outside, and a work space can be secured, so that the sheet feed roller can be easily replaced.
[0009]
When the guide member is slid in the direction away from the fitting portion after the unit is detached from the main body, the paper feed roller is also slid accordingly. When the paper feed roller slides, the other end of the roller shaft and the fitting portion of the structure are disengaged, and the paper feed roller can be taken out. Since the paper feed roller can be taken out simply by sliding the guide member away from the fitting portion, the paper feed roller can be replaced more easily.
[0010]
According to a second aspect of the present invention, in the first aspect of the invention, the fitting portion includes a roller that is disengaged from the fitting portion below the other end of the roller shaft that is fitted to the fitting portion. A rib for receiving a shaft is provided.
[0011]
According to the second aspect of the present invention, when the fitting portion is provided with a rib, the feeding roller is slid and the other end of the roller shaft and the fitting portion are disengaged. Since the other end of the roller shaft is in contact with the rib, the feeding roller can be prevented from falling.
[0012]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the main body includes an openable / closable side wall, and the paper feed roller is provided in the vicinity of the side wall. When opened, the unit is detached from the opening.
[0013]
In the invention according to claim 3, since the paper feed roller is disposed in the vicinity of the side wall that can be opened and closed with respect to the main body, the paper feed roller can be seen immediately when the side wall is opened. The work such as replacement is further simplified. Further, when the side wall is opened, the unit is detached from the main body, so that a certain space is formed above the paper feed roller, and a work space can be secured.
[0014]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the guide member is formed with a locking portion, and one end of the roller shaft is formed with an engaging portion. The engaging portion is locked to the engaging portion.
[0015]
According to the fourth aspect of the present invention, since the engaging portion of the guide member is engaged with the engaging portion of the paper feed roller, the paper feed roller and the guide member can slide integrally with a simple configuration. .
[0016]
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, when the paper feed roller is slid on the guide member side, the side surface of the paper feed roller is abutted against the guide member side. A projecting portion that is in contact is provided.
[0017]
According to the fifth aspect of the present invention, when the guide member is slid, the paper feed roller also slides together with the guide member, and the side surface of the paper feed roller contacts the protruding portion. When the side surface of the paper feed roller comes into contact with the protruding portion, the other end of the roller shaft of the paper feed roller rotates upward with the tangent portion as a fulcrum, and is disengaged from the fitting portion. Since the paper feed roller can be removed simply by sliding the guide member, the paper feed roller can be removed more easily.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment will be described with reference to the accompanying drawings. The copying machine 1 shown in FIG. 1 scans and reads a document, digitizes it, and copies it onto a recording medium (hereinafter referred to as “paper”) as will be described later. The apparatus has a multi-function having both a facsimile function for exchanging image information of a document with a remote place and a so-called printer function for printing image information handled by a computer on paper.
[0019]
The copier 1 is an in-body discharge type copier, and is arranged in order of the reading unit 3, the image forming unit 5, and the paper feeding unit 7 from the top. A space between the image forming unit 5 and the reading unit 3 is formed as a paper discharge storage unit 4, and a sheet on which an image is formed is discharged and stored.
[0020]
The image forming unit 5 includes a charging device 11 that charges the surface of the photoconductor 9 around the drum-shaped photoconductor 9, an exposure device 13 that irradiates the surface of the photoconductor 9 with laser light and image information. A developing device 15 that visualizes an electrostatic latent image formed by exposure on the surface of the body 9, a transfer device 17 that transfers a toner image developed on the photoreceptor 9 to a sheet, and remains on the surface of the photoreceptor 9 after transfer. A cleaning device 19 that removes and collects the toner to be recovered is disposed. The photoreceptor 9, the charging device 11, the developing device 15, and the cleaning device 19 form a single developing unit 21.
[0021]
In addition to the image forming unit 5 described above, there is a fixing unit 23 for fixing the toner on the paper to which the toner image is transferred. The fixing unit 23 is disposed above the developing unit 21 and includes a fixing roller 24 and a paper discharge device 25. The paper that has passed through the fixing unit 23 is discharged and stored in the paper discharge storage unit 4 by the paper discharge device 25.
[0022]
The developing unit 21, the fixing unit 23, and the exposure device 13 are supported by a resin structure 26 (see FIG. 2) in the main body, and the developing unit 21 and the fixing unit 23 can be attached to and detached from the main body. It has become.
[0023]
In the reading unit 3, a reading traveling body 27 including a light source for illuminating a document and a mirror moves reciprocally with respect to the document loaded on the contact glass 29, thereby scanning the document. The image information scanned by the reading traveling body 27 is read as an image signal into a CCD (Charge Coupled Device Image Sensor) 33 disposed behind the lens 31 (right side in the figure). The read image signal is digitized and subjected to image processing.
[0024]
Based on the image-processed signal, an optical signal generated by light emitted from an LD (laser diode) in the exposure device 13 reaches the photoconductor 9 via a polygon mirror or lens, and an electrostatic latent image is formed on the surface of the photoconductor 9. It is formed.
[0025]
The side wall located at the rear (right side in the figure) of the copying machine 1 can be opened and closed with respect to the main body, and the side wall 47 is opened for maintenance such as replacement of the paper feed roller 39 or replacement of toner. A manual paper feeder 49 is disposed in the vicinity of the side wall 47, and the paper stacked on the paper stacking plate 51 slidable in the direction of arrow “a” in the drawing is conveyed to the registration roller 43 by the pickup roller 53.
[0026]
The paper feed unit 7 includes a paper feed cassette 35 and a paper transport unit (see FIG. 2) 40. Unused paper is stored in the paper feed cassette 35, and the spring 41 pressurizes the bottom plate 37 that is rotatably supported to press the uppermost paper against the paper feed roller 39. The uppermost sheet is fed from the sheet feeding cassette 35 by the rotation of a sheet feeding roller 39 described later, and is conveyed to the registration roller 43 through the guide plate 45. The registration roller 43 conveys the sheet to the photosensitive member 9 at a timing so that the positional relationship between the toner image on the surface of the photosensitive member 9 and the leading edge of the sheet becomes a predetermined position.
[0027]
FIG. 2 is a perspective view showing a state where the side wall 47 is opened and the developing unit 21 and the fixing unit 23 are detached from the main body. Note that the manual sheet feeder 49 is omitted in FIG.
[0028]
As shown in FIG. 2, the paper transport unit 40 is disposed in the vicinity of the side wall 47, and includes a paper feed roller 39 and a drive unit 55. Further, as shown in FIG. 3, the paper transport unit 40 is supported by each of the wall portions 57 a to 57 c (see FIG. 3) extending from the structure 26. In this way, the paper feed roller 39 is disposed in the vicinity of the side wall 47, and when the side wall 47 is opened, the paper feed roller 39 can be seen immediately. Therefore, operations such as replacement of the paper feed roller 39 are easy. .
[0029]
As shown in FIG. 3, the structure 26 has wall portions 57 a to 57 c, and a boss (fitting portion) 61 into which one end portion 59 a of a roller shaft 59 described later is fitted on the wall portion 57 a. It extends in the direction of the paper feed roller 39. Inside the boss 61, a pressing pin 65 urged in the direction of the paper feed roller by a spring 67 is disposed. The tip of the pressing pin 65 is in contact with one end portion 59 a of the roller shaft 59 through a hole 69 formed on the paper feed roller 39 side of the boss 61. In addition, a rib 63 extending in the direction of the paper feed roller 39 is formed below the boss 61 on the wall portion 57 a to prevent the paper feed roller 39 from falling.
[0030]
A hole 79 through which a guide member 75 described later is passed is formed in the wall portion 57b, and the guide member 75 is disposed in the hole 79. A hole 83 through which a drive shaft 73 described later is passed is formed in the wall portion 57c, and a bearing 85 of the drive shaft 73 is fitted in the hole 83.
[0031]
The paper feed roller 39 is rotated by a roller shaft 59 to which a rotational force from a drive shaft 73 described later is transmitted. A concave portion 71 is formed at one end portion 41 a of the roller shaft 41, and engages with the boss 61. At this time, the tip end of the pressing pin 65 is in contact with the substantially central position of the recess 71.
[0032]
The other end portion 59b of the roller shaft 41 has a substantially D-shaped cross section, and is fitted into the drive shaft 73 through a guide member 75 described later. For this reason, the other end 59b and the drive shaft 73 are in a state in which they cannot rotate with respect to each other. Further, the axis of the roller shaft 59 and the drive shaft 73 coincide with each other.
[0033]
The drive unit 55 includes a drive shaft 73 and a guide member 75. The drive shaft 73 is slidable left and right in the drawing, and transmits a drive force from a drive source (not shown) to the roller shaft 59. The end of the drive shaft 73 on the paper feed roller 39 side has a substantially D-shaped projection that fits into the shape of the other end 59b of the roller shaft 59. The other end 59b of the shaft 59 is fitted. Accordingly, the drive shaft 73 is supported by the fitting with the other end portion 59 b and the bearing 85. A groove 73a is formed in the drive shaft 73 in the guide member 75, and a claw 75b described later meshes with the groove 73a.
[0034]
The guide member 75 has a hollow cylindrical shape and is disposed in a hole 79 formed in the wall portion 57b. The guide member 75 connects and supports the drive shaft 73 and the other end portion 59 b of the paper feed roller 39. A handle member 77 is integrally formed with the guide member 75 on one side and on the upper side of the guide member 75 on the paper feed roller 39 side, and the lower part is an extension portion 75a extending in the direction of the paper feed roller 39. Is formed. The extension portion 75a and the rib 63 described above prevent the paper feed roller 39 from falling.
[0035]
The guide member 75 is biased in the direction of the paper feed roller 39 by a spring 81 having a stronger biasing force than the spring 67 of the pressing pin 65 described above. Therefore, normally, the one end portion 59a of the roller shaft 59 is slid in the direction of the arrow a by the urging force of the spring 81 and is engaged with the boss 61.
[0036]
A claw portion 75 b extending downward is formed inside the guide member 75 and meshes with the groove portion 73 a of the drive shaft 73. Thereby, the drive shaft 73 and the guide member 75 slide integrally. Note that the claw portion 75b and the groove portion 73a are merely engaged with each other, and thus do not affect the rotation of the drive shaft 73. In addition, although the material which comprises the guide member 75 is not specifically limited, It is preferable that it is comprised with materials, such as resin, and the guide member 75 is comprised with resin in this Embodiment.
[0037]
Next, the operation of the first embodiment will be described based on the configuration described above.
[0038]
Normally, the paper feed roller 39 rotates with one end portion 59 a of the roller shaft 59 fitted to the boss 61, and conveys the paper stored in the paper feed cassette 35 to the photoconductor 9. When the paper feed roller 39 is worn out, the paper feed roller 39 is replaced.
[0039]
When replacing the paper feed roller 39, first, the side wall 47 is opened, and the developing unit 21 and the fixing unit 23 located above the paper feed roller 39 are separated from the main body. When these are separated, a certain space is formed above the paper feed roller 39 as shown in FIG. Since a certain space is formed above the sheet feeding roller 39, the sheet feeding roller 39 can be visually confirmed from the outside, and a work space can be secured, so that the sheet feeding roller 39 can be easily replaced.
[0040]
After the developing unit 21 and the fixing unit 23 are attached and detached, the handle member 77 of the guide member 75 is held, and the guide member 75 is moved in the direction of the wall portion 57b. As a result, the guide member 75 and the drive shaft 73 are integrally slid rightward, and the paper feed roller 39 is pushed rightward by the pressing pin 65. When the paper feed roller 39 is pushed rightward, as shown in FIG. 3, the engagement between the one end portion 59a of the roller shaft 59 and the boss 61 is released, and the paper feed roller 39 can be taken out. By simply sliding the guide member 75 to the right, the sheet feeding roller 39 can be taken out, so that the sheet feeding roller 39 can be replaced more easily.
[0041]
Next, the second embodiment will be described. In the description thereof, the same parts as those described above are denoted by the same reference numerals, and the description thereof is omitted.
[0042]
In the second embodiment, as shown in FIG. 4, a locking claw (locking portion) 75 c is formed on one side and on the upper side of the guide member 75 on the paper feed roller 39 side. The only difference from the first embodiment is that an engaging groove (engaging portion) 59c that engages with the locking claw 75c is formed in the end portion 59b.
[0043]
The locking claw 75c is engaged with the engagement groove 59c using the elasticity of the resin material. Therefore, the guide member 75 and the paper feed roller 39 can be slid integrally. When the paper feed roller 39 is taken out, the locking claw 75c is elastically deformed so that the engagement with the engagement groove 59c is released. Note that the locking claw 75c and the engaging groove 59c are merely engaged, and thus do not affect the rotation of the paper feed roller 39.
[0044]
As described above, since the engaging claw 75 c and the engaging groove 59 c are engaged, when the guide member 75 is slid to the right, the paper feed roller 39 is also slid to the right together with the guide member 75. Therefore, unlike the first embodiment, the pressing pin 65 for sliding the paper feed roller 39 to the right is not necessary, so the number of parts is reduced and the configuration is simple.
[0045]
Next, a third embodiment will be described. In the third embodiment, as shown in FIG. 5, a projecting portion 87 is formed below the wall portion 57 b and on the paper feed roller 39 side so as to contact one side of the paper feed roller 39. Only this is different from the second embodiment.
[0046]
The protruding portion 87 is formed at a position where the paper feed roller 39 that has been slid integrally with the guide member 75 contacts one side of the paper feed roller 39 when the paper feed roller 39 slides a predetermined distance.
[0047]
When one side of the sheet feeding roller 39 slid rightward comes into contact with the protruding portion 87 and further slid rightward, the sheet feeding roller 39 rotates upward with the contact point as a fulcrum. When the paper feed roller 39 rotates upward, the engagement between the one end portion 59a of the roller shaft 59 and the boss 61 is released, and the wall portion 57a of the paper feed roller 39 jumps upward as shown in FIG. The paper feed roller 39 is removed.
[0048]
As described above, since the paper feed roller 39 can be removed simply by sliding the guide member 75, the replacement of the paper feed roller 39 is further simplified.
[0049]
In addition, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the summary, various deformation | transformation are possible.
[0050]
For example, in the present embodiment, the other end portion 59a of the roller shaft 59 is formed in a concave shape and is fitted to the boss 61. However, the other end portion 59a is formed in a protruding shape so that the wall portion 57a is replaced with the boss 61. Recesses may be formed and fitted together. The same applies to the claw portion 75b of the guide member 75 and the groove portion 73a of the drive shaft 73, and the engaging claw 75c of the guide member 75 and the engagement groove 59c of the roller shaft 59.
[0051]
Although the present invention is applied to the multifunctional copying machine 1, the present invention is not limited to this. For example, even when applied to a simple copying machine, printer, facsimile, etc., the same effects can be obtained.
[0052]
【The invention's effect】
According to the first aspect of the present invention, since the unit located above the paper feed roller can be detached from the main body, the paper feed roller can be visually confirmed from the outside and a work space can be secured. Becomes easier. Further, since the paper feed roller can be taken out only by sliding the guide member in the direction away from the fitting portion, the replacement of the paper feed roller is further simplified.
[0053]
According to the second aspect of the present invention, the sheet feeding roller can be prevented from dropping due to the configuration in which the fitting portion is provided with the rib.
[0054]
According to the third aspect of the present invention, since the paper feed roller is disposed in the vicinity of the side wall that can be opened and closed with respect to the main body, the replacement of the paper feed roller is further simplified and a working space can be secured.
[0055]
According to the fourth aspect of the present invention, since the engaging portion of the guide member is engaged with the engaging portion of the paper feed roller, the paper feed roller and the guide member can be integrally slid with a simple configuration.
[0056]
In the invention according to the fifth aspect, since the projecting portion is provided, the feeding roller can be taken out more easily.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically showing a copying machine to which the present invention is applied.
FIG. 2 is a perspective view showing a state in which the side wall of the copying machine of FIG. 1 is opened.
FIG. 3 is an enlarged cross-sectional view of the vicinity of a paper feed roller according to the first embodiment.
FIG. 4 is an enlarged cross-sectional view of the vicinity of a paper feed roller according to a second embodiment.
FIG. 5 is an enlarged cross-sectional view of the vicinity of a paper feed roller according to a third embodiment.
[Explanation of symbols]
1 Copying machine (image forming device)
5 Image forming unit 9 Photoconductor 13 Exposure device 15 Development device 21 Development unit 24 Fixing unit 26 Structure 35 Paper feed cassette 39 Paper feed roller 47 Side wall 59 Roller shaft 59c Engaging groove (locking portion)
61 Boss (Fitting part)
63 Rib 73 Drive shaft 75 Guide member 75a Extension part 75c Locking claw (engagement part)
87 Projection

Claims (5)

An image forming unit in which a unit including at least one of a photoconductor, a developing device, an exposure device, and the like can be attached to and detached from the main body, a paper feeding cassette for loading paper, and a paper on the paper feeding cassette to form the image A feed roller that feeds the roller, a drive shaft that is coupled to one end of a roller shaft of the feed roller and is slidable in the axial direction, a fitting portion that fits the other end of the roller shaft, and the drive An image forming apparatus comprising: a guide member that slides an axis in an axial direction; and a structure that supports the image forming unit, the paper feed roller, and the drive shaft,
When the guide member is slid in a direction away from the fitting portion, the paper feed roller slides together with the guide member, and the fitting between the other end of the roller shaft and the fitting portion is released. An image forming apparatus. 2. The rib of the fitting portion is provided with a rib that receives a roller shaft that is disengaged from the fitting portion under the other end of the roller shaft that is fitted to the fitting portion. The image forming apparatus described. 2. The main body is provided with a side wall that can be opened and closed, and the paper feed roller is provided in the vicinity of the side wall, and the unit is detached from the opening when the side wall is opened. Or the image forming apparatus according to 2; 4. A locking portion is formed on the guide member, an engaging portion is formed at one end of the roller shaft, and the locking portion is locked to the engaging portion. The image forming apparatus according to claim 1. 5. The projecting portion according to claim 1, wherein a protrusion is provided on the guide member side so as to contact a side surface of the paper feed roller when the paper feed roller is slid. 6. The image forming apparatus described.

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