JP3666935B2 - Image forming apparatus - Google Patents

Description

[0001]
The present invention relates to an image forming apparatus in which a process cartridge for forming an image by an electrophotographic recording method can be detachably mounted.
[0002]
[Prior art]
Conventionally, in an image forming apparatus using an electrophotographic image forming process, the electrophotographic photosensitive member and the process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the image forming apparatus main body. The process cartridge method is adopted. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. For this reason, this process cartridge system is widely used in image forming apparatuses.
[0003]
In such a process cartridge, as shown in FIGS. 11 (a) to 11 (c), guide members 51 and 52 for guiding both side surfaces in the longitudinal direction of the process cartridge 50 provided in the image forming apparatus main body are attached to a frame 56 by screws 55. The bosses 50a provided on both side surfaces of the cartridge 50 are inserted along the guide grooves 53 and mounted.
[0004]
In order to position the process cartridge 50 on one side in the longitudinal direction, a leaf spring 54 is attached to one guide member 51, and when the process cartridge 50 is inserted, one side surface of the cartridge 50 is pressurized to the other side. Positioning is performed such that the side surface is in close contact with the guide member 52.
[0005]
[Problems to be solved by the invention]
The present invention is a further development of the above-described image forming apparatus, and an object of the present invention is to provide an image forming apparatus that can pressurize a process cartridge using an inexpensive elastic member and reduce costs. Is to provide. The present invention also provides an image forming apparatus having a good insertion feeling of a process cartridge.
[0006]
In order to achieve the above object, a typical configuration according to the present invention includes a transport unit for transporting the recording medium in an image forming apparatus in which a process cartridge is detachable and forms an image on the recording medium. A guide member provided so as to be able to swing; a guide member for guiding the process cartridge in an insertion direction for inserting the process cartridge into the image forming apparatus; and an urging unit configured integrally with the guide member. Urging means for urging the guide member in an orthogonal direction perpendicular to the insertion direction, and the guide member is urged by the urging means when the process cartridge is inserted into the image forming apparatus. The process cartridge is pressurized in the orthogonal direction.
[0007]
[Action]
In the above configuration, when the process cartridge is guided by the guide member and inserted into the apparatus main body, the guide member biased by the biasing means swings and pressurizes and positions the process cartridge. The biasing means is constructed integrally with the guide member. Furthermore, since it is not in direct contact with the process cartridge, it is not necessary to use an expensive leaf spring.
[0009]
【Example】
Next, a reference embodiment on which the present invention is based will be described with reference to the drawings. The reference embodiment is not included in the present invention because the biasing means is not integrally formed with the guide member.
[0010]
[Reference Example]
First, a process cartridge according to a reference embodiment and an image forming apparatus to which the process cartridge can be mounted will be described in detail with reference to FIGS. 1 is a schematic explanatory view of the structure of the guide member, FIG. 2 is a schematic explanatory view of the structure of the image forming apparatus equipped with the process cartridge, FIG. 3 is an explanatory view of the structure of the process cartridge, and FIGS. FIG. 6 is an explanatory diagram of a process cartridge mounting configuration.
[0011]
Here, as an order of description, first, the overall configuration of the process cartridge and the image forming apparatus using the process cartridge will be described with reference to FIGS. 2 to 7, and then the configuration of the guide member will be described with reference to FIG.
[0012]
{overall structure}
As shown in FIG. 2, this electrophotographic image forming apparatus (laser beam printer) A irradiates information light based on image information from an optical system 1 onto a drum-shaped electrophotographic photosensitive member, thereby forming a latent image on the photosensitive member. And developing the latent image to form a toner image. In synchronism with the formation of the toner image, the recording medium 2 is separated and fed one by one from the paper feed cassette 3a by the pickup roller 3b and the pressure contact member 3c pressed against it, and the conveyance roller pair 3d and registration roller pair 3e. The toner image formed on the electrophotographic photosensitive member, which is transported by the transporting means 3 composed of, etc. and formed into a cartridge as the process cartridge B, is transferred to the recording medium 2 by applying a voltage to the transfer roller 4 as the transfer means, The recording medium 2 is conveyed to the fixing unit 5 by the conveyance belt 3f. The fixing means 5 includes a driving roller 5a, a heater 5b, a fixing rotating body 5d made of a cylindrical sheet that is rotatable and supported by a support 5c, and applies heat and pressure to the recording medium 2 passing therethrough. To fix the transferred toner image. The recording medium 2 is conveyed by a pair of ejection rollers 3g and 3h, and is ejected to the ejection unit 6 through a reverse conveyance path. The image forming apparatus A can also be manually fed by a manual feed tray 3i and a roller 3j.
[0013]
On the other hand, the process cartridge B includes an electrophotographic photosensitive member and at least one process means. Here, as the process means, for example, a charging means for charging the electrophotographic photosensitive member, a developing means for developing the latent image formed on the electrophotographic photosensitive member, and a cleaning means for cleaning the toner remaining on the surface of the electrophotographic photosensitive member. Etc. As shown in FIG. 3, the process cartridge B of the present embodiment rotates a photosensitive drum 7 which is an electrophotographic photosensitive member having a photosensitive layer, and applies a voltage to a charging roller 8 which is a charging means to apply the voltage to the photosensitive drum. The surface of the drum 7 is uniformly charged, a light image from the optical system 1 is exposed to the charged photosensitive drum 7 through the opening 9 to form a latent image, and the latent image is developed. The developing is performed by the means 10.
[0014]
The developing means 10 feeds the toner in the toner storage portion 10a by a rotatable first feeding member 10b1 and second feeding member 10b2 which are feeding means, and a developing roller 10d which is a developing rotating body incorporating a fixed magnet 10c. A toner layer is formed on the surface of the developing roller 10d by rotating the developing blade 10e while applying a triboelectric charge, and the toner is transferred to the photosensitive drum 7 according to the latent image to form a toner image. It is to be visualized.
[0015]
After the toner image is transferred to the recording medium 2 by applying a voltage having a polarity opposite to that of the toner image to the transfer roller 4, the toner remaining on the photosensitive drum 7 is scraped off by the cleaning blade 11a and scooped by the squeeze sheet 11b. The residual toner on the photosensitive drum 7 is removed by the cleaning means 11 that collects and collects in the waste toner storage portion 11c.
[0016]
Each member such as the photosensitive drum 7 is constituted by coupling a developing frame 12a, a developing lower frame 12b and a toner developing frame 12 which are integrated by welding a lid member 12c, and a cleaning frame 13. The cartridge is stored in the cartridge frame and is detachably mounted on the cartridge mounting means provided in the apparatus main body 14.
[0017]
The process cartridge B is attached / detached by opening the opening / closing member 15 around the shaft 15a as shown in FIGS. 4 and 5, but when the opening / closing member 15 is opened, a cartridge mounting space is provided in the apparatus main body 14. As shown in FIGS. 6 and 7, cartridge mounting guide members 17 and 18 are attached to the frames 16 on the left and right side surfaces of the space so as to face each other. On the other hand, a boss 19 (see FIG. 3) is formed on both outer side surfaces of the process cartridge B in the longitudinal direction. The boss 19 is formed in a guide groove 20 formed by the left and right guide members 17 and 18 and the frame 16. Along with this, the process cartridge B is inserted. A concave portion 20a is formed in the groove 20 at the back, and the shaft portion 19a of the boss 19 is dropped into the concave portion 20a to mount a cartridge. At this time, a drum gear (not shown) attached to the end of the photosensitive drum 7 in the longitudinal direction meshes with a driving gear 25 provided in the apparatus main body 14 so that drive transmission is performed to the photosensitive drum 7.
[0018]
{Configuration of guide member}
Next, the guide members 17 and 18 will be described with reference to FIG. 1A is an explanatory view of the guide member attached to the frame 16 as viewed from the front, and FIG. 1B is a schematic cross-sectional explanatory view taken along line AA of FIG.
[0019]
The guide members 17 and 18 are both formed of a sliding grade mold member that has good slidability with the process cartridge B, and the left guide member 17 is formed in a hole 16a formed with a locking claw 17a in the frame 16. The guide groove 20 is formed by the lower surface of the guide member 17 and the frame 16. The guide member 17 is fixed to the frame 16.
[0020]
On the other hand, the right guide member 18 is similarly fitted in and locked to a hole 16a formed in the frame with a locking claw 18a attached thereto, and a guide groove 20 is formed by the lower surface of the guide member 18 and the frame 16. . The guide member 18 is attached to the frame 16 so as to be swingable. That is, guide shafts 18b, 18c, 18d are provided on the back side of the swing guide member 18 (the back side of the surface in contact with the process cartridge B), and these shafts are fitted into positioning holes 16b formed in the frame 16. ing. A pressure spring 21 is lightly press-fitted to the shaft 18c, and the guide member 18 is urged in the direction of arrow a in FIG.
[0021]
The clearance between the shafts 18b, 18c, and 18d and the hole 16b into which the shafts 18b and 18d are inserted does not cause so-called biting when the guide member 18 swings in the direction of arrow b about the axis connecting the shafts 18b and 18d. It is configured to be about 0.3 mm to 0.5 mm. As a result, the swing guide member 18 can swing in the directions of arrows a and b in FIG. 1 (a) with the axis connecting the hole 16b into which the shafts 18b and 18d are fitted as a hinge.
[0022]
In the guide structure as described above, when the cartridge is inserted with the boss 19 of the process cartridge B along the guide groove 20 as described above, both side surfaces of the cartridge are guided by the guide members 17 and 18. At this time, the swing guide member 18 is pushed from the free position (the position indicated by the one-dot chain line in FIG. 1B) to the side surface of the process cartridge B to the cartridge setting position (the position indicated by the solid line in FIG. 1B). Gradually rushed. Due to the compression of the pressure spring 21 at this time, the process cartridge B is pressed in the direction of arrow a by the swing guide member 18, and one side surface is in close contact with the fixed guide member 17, and the thrust direction of the photosensitive drum 7 is positioned. .
[0023]
Thus, by configuring at least one of the guide members 18 to be swingable, the process cartridge B can be urged and positioned in the thrust direction without using a leaf spring. Further, since the guide members 17 and 18 are made of a sliding grade mold member, even if the process cartridge B is rubbed against the guide members 17 and 18 in a pressed state, the guide members 17 and 18 are attached and detached without feeling a great resistance. The operability is also improved.
[0024]
The guide members 17 and 18 can be attached with one touch by locking the locking claws to the frame 16.
[0025]
[First embodiment]
Next, a first embodiment to which the present invention is applied will be described with reference to FIG. 8 (a) is an explanatory view of the swing guide member attached to the frame 16 as seen from the front, and FIG. 8 (b) is a schematic cross-sectional explanatory view taken along line AA in FIG. 8 (a). c) is a schematic cross-sectional explanatory view taken along the line BB of FIG.
[0026]
Further, the process cartridge and the image forming apparatus to be used are the same as those in the above-described reference embodiment, and members having the same functions as those in the above-described reference embodiment are denoted by the same reference numerals and redundant description is omitted.
[0027]
The swing guide member 22 according to the first embodiment is attached to the frame 16 so that the locking claw 22a is locked to the frame 16, and is guided by the guide shafts 22b and 22c so that the shafts 22b and 22c are inserted into the holes 16b. As in the reference embodiment, the axis connecting the two is used as a hinge and is swingable about the hinge. This differs from the swing guide member 18 of the reference embodiment in that the reference embodiment constitutes an urging means by the pressurizing spring 21, whereas in the first embodiment, the mold integral with the guide member 22 is used. The spring portion 22d is formed, thereby constituting the biasing means.
[0028]
By configuring the biasing means integrally with the guide member 22 in this way, not only the same effects as in the reference embodiment can be obtained, but a dedicated spring is not necessary, and it can be configured at a lower cost. It will be.
[0029]
[ Second Reference Example ]
Next, a second reference embodiment to which the present invention is applied will be described with reference to FIG. 9A is an explanatory view of the swing guide member attached to the frame 16 as viewed from the front, and FIG. 9B is a schematic cross-sectional explanatory view taken along line AA of FIG. 9A. The reference embodiment is not included in the present invention because the biasing means is not integrally formed with the guide member .
[0030]
Further, the process cartridge and the image forming apparatus to be used are the same as those in the above-described reference embodiment, and members having the same functions as those in the above-described reference embodiment are denoted by the same reference numerals and redundant description is omitted.
[0031]
The swing guide member 23 according to the second reference embodiment is mounted in a state in which the locking claw 23a is locked to the frame 16 to prevent the swinging guide member 23 from being detached, and is swingable by being guided by the guide shafts 23b, 23c, 23d. The point that the process cartridge B can be pressurized by the pressure spring 21 attached to the shaft 23d is the same as that of the reference embodiment described above. This is different from the above-described reference embodiment in that the insertion hole 16c of the frame 16 into which the guide shafts 23b and 23c are inserted is constituted by a long hole in the vertical direction, and the guide member 23 connects 16c into which the shafts 23b and 23c are inserted. The axis is a hinge, and when swinging about the hinge, swinging in the direction perpendicular to the long hole direction is restricted.
[0032]
By configuring the swing guide member as described above, the same effects as those of the reference embodiment described above can be obtained, and when the guide member 23 swings, the backlash in the direction perpendicular to the long hole is suppressed to 0.1 mm or less. It can be done.
[0033]
[ Second Embodiment ]
Next, a second embodiment to which the present invention is applied will be described with reference to FIG. 10 (a) is an explanatory view of the swing guide member attached to the frame 16 as viewed from the front, and FIG. 10 (b) is a schematic cross-sectional explanatory view taken along line AA of FIG. 10 (a).
[0034]
Further, the process cartridge and the image forming apparatus to be used are the same as those in the above-described reference embodiment, and members having the same functions as those in the above-described reference embodiment are denoted by the same reference numerals and redundant description is omitted.
[0035]
The swing guide member 24 according to the second embodiment is attached to the frame 16 so that the locking claw 24a is locked to the frame 16, and is guided by the guide shafts 24b and 24c. The guide member 24 is inserted into the shafts 24b and 24c. The axis line connecting 16c is a hinge and is configured to be swingable in the direction of the arrow with the hinge as the center, similar to the reference embodiment described above. The urging means for pressurizing the process cartridge B via the guide member 24 is formed by forming a mold spring portion 24d integral with the guide member 24 as in the first embodiment. Further, the insertion hole 16c of the frame 16 into which the guide shafts 24b, 24c are inserted is formed as a long hole in the vertical direction as in the second reference embodiment, and the long hole is formed when the guide member 24 swings. It is configured so as to regulate the swing in the direction perpendicular to the direction.
[0036]
With this configuration, the process cartridge can be urged in the thrust direction without using a leaf spring as in the above-described reference embodiment, and specially as an urging means as in the above-described first embodiment. Further, there is no need for a spring or the like, and the backlash in the direction perpendicular to the long hole of the swing guide member 24 can be suppressed to 0.1 mm or less as in the second reference embodiment. It can be obtained.
[0037]
[Other Examples]
Next, another example of each part of the process cartridge B and the image forming apparatus according to the above-described embodiment will be described.
[0038]
The process cartridge B described above is for forming a single color image. However, the process cartridge is not limited to the case of forming a single color image, but a plurality of developing means are provided so that a plurality of color images (for example, two color images, three color images, etc.) are provided. The present invention can also be suitably applied to a cartridge for forming a color image or full color).
[0039]
As the developing method, various developing methods such as a known two-component magnetic brush developing method, cascade developing method, touch-down developing method, and cloud developing method can be used.
[0040]
The electrophotographic photosensitive member is not limited to the photosensitive drum, and includes, for example, the following. First, a photoconductor is used as the photoreceptor, and examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and organic photoconductor (OPC). The shape for mounting the photosensitive member includes, for example, a rotating member such as a drum shape or a belt shape, and a sheet shape. In general, a drum-like or belt-like one is used. For example, in the case of a drum-type photoreceptor, a photoconductor is vapor-deposited or coated on a cylinder such as an aluminum alloy. It is.
[0041]
In addition, the so-called contact charging method is used in the first embodiment described above for the structure of the charging means. However, as another structure, a metal shield such as aluminum is provided around three sides of a tungsten wire conventionally used, and the tungsten wire Of course, it is also possible to use a configuration in which positive or negative ions generated by applying a high voltage to the surface of the photosensitive drum are moved to the surface of the photosensitive drum and the surface of the drum is uniformly charged.
[0042]
In addition to the roller type, the charging unit may be a blade type (charging blade), a pad type, a block type, a rod type, a wire type, or the like.
[0043]
Further, as a method for cleaning the toner remaining on the photosensitive drum, the cleaning unit may be configured using a blade, a fur brush, a magnetic brush, or the like.
[0044]
The process cartridge described above includes, for example, an electrophotographic photosensitive member and at least one process means. Therefore, as an aspect of the process cartridge, in addition to the embodiment described above, for example, the electrophotographic photosensitive member and the charging means are integrally formed into a cartridge so that it can be attached to and detached from the apparatus main body. An electrophotographic photosensitive member and developing means are integrated into a cartridge so that it can be attached to and detached from the apparatus main body. An electrophotographic photosensitive member and a cleaning means are integrated into a cartridge so that it can be attached to and detached from the apparatus main body. Further, there is a combination of an electrophotographic photosensitive member and two or more of the above process means, which are integrated into a cartridge so that it can be attached to and detached from the apparatus main body.
[0045]
That is, the process cartridge described above is a cartridge in which a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive member are integrally formed, and this cartridge can be attached to and detached from the image forming apparatus main body. In addition, at least one of the charging unit, the developing unit, and the cleaning unit and the electrophotographic photosensitive member are integrally formed into a cartridge that can be attached to and detached from the main body of the image forming apparatus. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrated into a cartridge so that it can be attached to and detached from the apparatus main body.
[0046]
In the above-described embodiments, the photosensitive drum and the developing roller are made into cartridges, and an apparatus for forming an image by attaching the process cartridge is exemplified. The present invention can be similarly applied to an image forming apparatus directly attached.
[0047]
Further, in the above-described embodiments, the laser beam printer is exemplified as the image forming apparatus. However, the present invention is not limited to this, and other image forming apparatuses such as an LED printer, an electrophotographic copying machine, a facsimile apparatus, or a word processor are used. Of course, it can be used.
[0048]
【The invention's effect】
As described above, the present invention is configured such that the guide member that guides the insertion of the process cartridge into the apparatus main body can be swung, and the guide member is biased by the biasing means. The guide member is integrally formed. Therefore, in order to pressurize the process cartridge in the thrust direction, a dedicated spring or the like is not necessary, and it is not necessary to use an expensive leaf spring, so that a configuration for protecting the edge portion of the leaf spring is also unnecessary. Further, the process cartridge can be urged in the thrust direction at low cost, and the cost of the image forming apparatus can be reduced.
[0050]
Further, if the urging means is configured integrally with the guide member, a dedicated spring or the like as the urging means becomes unnecessary, and the cost can be further reduced.
[0051]
Further, if the guide member is configured to be locked and attached to the retaining state by the locking claw, the guide member can be attached with one touch.
[Brief description of the drawings]
FIG. 1A is a configuration explanatory view of a guide member according to a reference embodiment, and FIG. 1B is a state explanatory view as seen from a section AA in FIG.
FIG. 2 is a schematic explanatory diagram of a configuration of an image forming apparatus.
FIG. 3 is a schematic explanatory diagram of a configuration of a process cartridge.
FIG. 4 is an explanatory diagram of a state in which a process cartridge is mounted.
FIG. 5 is an explanatory diagram of an internal state in which a process cartridge is mounted.
FIG. 6 is an explanatory view of the appearance with a swing guide member attached.
FIG. 7 is an explanatory view of the appearance with a fixed guide member attached.
8A is an explanatory view of the guide member according to the first embodiment, FIG. 8B is an explanatory view of the AA cross section of FIG. 8A, and FIG. 8C is an explanatory view of the BB cross section of FIG. FIG.
9A is an explanatory view of a guide member according to a second reference embodiment , and FIG. 9B is an AA cross-sectional explanatory view of FIG. 9A.
10A is an explanatory view of a guide member according to a second embodiment , and FIG. 10B is an AA cross-sectional explanatory view of FIG.
11A is an explanatory view of a guide member according to the prior art, FIG. 11B is a state explanatory view seen from the AA cross section of FIG. 11A, and FIG. 11C is a BB cross section of FIG. It is explanatory drawing.

Claims (2)

In an image forming apparatus in which a process cartridge is detachable and forms an image on a recording medium.
Transport means for transporting the recording medium;
A guide member provided so as to be swingable, the guide member for guiding the process cartridge in an insertion direction for inserting the process cartridge into the image forming apparatus;
An urging means configured integrally with the guide member, the urging means for urging the guide member in a direction orthogonal to the insertion direction;
Have
The image forming apparatus, wherein when the process cartridge is inserted into the image forming apparatus, the guide member presses the process cartridge in the orthogonal direction by the biasing means.   The image forming apparatus according to claim 1, wherein the guide member swings while being guided by a guide shaft provided on the guide member.

Images