JP6241168B2 - Drum developing unit and image forming apparatus - Google Patents

Description

The present invention relates to a drum developing unit and an image forming apparatus .

  In an electrophotographic image forming apparatus such as a color printer, a color copy, a facsimile multifunction peripheral, etc., in-machine scattering such as toner and dust occurs due to long-term use. In particular, when these scattered toner or dusty foreign matter accumulates on the lens of the LED head, the exposure to the drum developing unit is shielded from light only in that portion, resulting in an image failure that causes white streaks in the printed image. In order to prevent such an image failure, there is an LED head cleaner.

  In Patent Document 1, a cleaning member is provided at the rear end of the photosensitive unit in the pull-out direction. When the photosensitive unit is inserted into the main body or pulled out from the main body, the cleaning member is slidably contacted with the charging member for cleaning. It has become. This cleaning member is a brush and is attached to the bracket in an oblique direction. Here, the bracket is a member that supports the photosensitive drum (end of paragraph 0008). Therefore, the bracket is considered to be a rigid member. The cleaning member will also be attached to the rigid member.

  In Patent Document 2, the cleaning member rubs the light beam exit surface and wipes off the toner as the charging unit enters and exits the main body. This cleaning member is similarly put in and out as the charging unit is put in and out. Although the cleaning member is depicted in many drawings of FIGS. 3 to 14, the cleaning member is provided vertically upright with respect to the charging / removing direction of the charging unit.

  In Patent Document 3, the cleaning member engages with the cartridge and cleans the cover glass as the cartridge is inserted and removed. In this cleaning member, the cleaning surface makes surface-to-surface contact with the cover glass.

  In patent document 4, the cleaning sheet which has flexibility makes the contact angle (angle of the direction which advances at the time of cleaning) an obtuse angle, especially 135 degree | times.

Japanese Patent Laid-Open No. 6-149022 JP 2007-240789 A JP 2009-244541 A JP 2009-244543 A

  In the technique described in Patent Document 1, the brush is attached at an angle, but the attached portion is a rigid member and is supported thereby.

  In the technique described in Patent Document 2, the cleaning member is provided upright with respect to the light beam exit surface.

  In the technique described in Patent Document 3, the cleaning surface makes surface-to-surface contact.

  The technique described in Patent Document 4 is a cleaning sheet having flexibility with a contact angle of 135 degrees, but the attachment is not particularly limited, and is considered to be attached to a rigid member.

  Here, an example of a more general electrophotographic color printer will be described in detail with reference to the drawings. FIG. 8A is a perspective view showing a conventional head cleaner. FIG. 8B is a side view of a conventional head cleaner. As shown in FIGS. 8 (a) and 8 (b), a conventional head cleaner has a cleaner base 97a formed by bending a rectangular PET (polyethylene terephthalate) film at a substantially right angle (90 degrees) and a cleaner pad made of rectangular felt. The contact portion 97b is bent and attached by approximately 180 degrees at its center.

  FIG. 9 shows a conventional head cleaner attachment position. FIG. 9 is a perspective view illustrating the bottom side of the drum developing unit 2 (the side to be inserted when inserted into the main body) upside down so that the bottom portion can be seen. When the drum developing unit 2 is viewed from the front, a head cleaner 97 is attached to the drum cover 5 corresponding to the back side of the short main body on the right side with a double-sided tape. Here, the drum cover 5 is a member that covers the photosensitive drum. The LED head is configured to form an image on the photosensitive drum. Since the focal length of the LED head lens is set to a short distance, the LED head lens is provided close to the photosensitive drum. Therefore, the LED head lens can be cleaned by attaching the head cleaner 97 to this position.

  FIG. 10 is a schematic cross-sectional view of the head cleaning mechanism installed in the drum developing unit 2. FIG. 10A shows a state immediately before the drum developing unit 2 is inserted into the main body of the electrophotographic color printer (image forming apparatus) 1. The drum developing unit 2 is inserted from left to right in FIG. A head cleaner 97 is provided on the drum cover 5 of the drum developing unit 2. When the drum developing unit 2 is inserted, the LED head 3 is lowered downward by about 10 mm from the drum developing unit. When the drum developing unit 2 is inserted, the drum developing unit 2 is separated to prevent it from being accidentally bumped and damaged or soiled.

  FIG. 10B shows the middle of insertion of the drum developing unit 2 (during lens cleaning). The head cleaner 97 attached to the drum developing unit 2 is cleaning the LED head lens 6 of the LED head 3. Since it is made of the head cleaner 97 PET film, it can be bent. Therefore, cleaning is performed while deforming from 90 degrees in a stationary state to an acute angle state. This angle is an angle formed by the direction in which the drum developing unit 2 is inserted and the cleaner base to which the cleaner contact portion of the head cleaner 97 is attached.

  FIG. 10C shows a state in which the drum developing unit 2 has been inserted. The LED head 3 is about to rise soon. In FIG. 10A, the drum developing unit 2 and the LED head 3 are separated. However, when the electrophotographic color printer 1 is used, it is necessary that the light from the LED head strikes the photosensitive drum of the drum developing unit 2 to form an image. Since the focal length of the LED head lens 6 is generally designed to be short, it is necessary to bring the LED head close to the photosensitive drum of the drum developing unit 2. Therefore, at the timing when the insertion of the drum developing unit 2 is completed, the LED head 3 rises and approaches the drum developing unit 2.

  Here, since the shape of the head cleaner 97 has returned to the 90 degree state, a collision may occur when the LED head 3 is raised. When the collision occurs, the LED head 3 cannot be raised to the original position, and as a result, an image focus failure may occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a drum developing unit and an image forming apparatus in which the LED head lens is cleaned by inserting and removing the drum developing unit without causing the user to be conscious of cleaning, and does not cause problems when the apparatus is used. To do.

In order to solve the above problems, a drum developing unit according to the present invention is a drum developing unit that is inserted into and removed from an image forming apparatus, and the drum developing unit is configured to clean the surface of an LED head lens for exposure. A head cleaner is provided at the head portion of the drum developing unit, and the head cleaner is folded in half so that the central portion has an acute angle, and faces the LED head lens when the drum developing unit is inserted and removed. A flexible film fixed to a side surface of the drum developing unit, and a flexible film that is provided at the central portion of the flexible film and supports the flexible film at an acute angle inside the bent portion. features and sex support member, and a other of the contact member attached to the distal end portion of the folded flexible film, that To.
In addition, an image forming apparatus according to the present invention is characterized in that the above-described drum developing unit is detachable .

According to the present invention, it is possible to provide a drum developing unit and an image forming apparatus in which the LED head lens is cleaned by inserting and removing the drum developing unit without causing the user to be aware of the cleaning, and no problem occurs when the apparatus is used .

1 is an external perspective view of a main body of an electrophotographic color printer (image forming apparatus). It is a perspective view which shows the state which opened the front door of the electrophotographic color printer main body. FIG. 6 is a perspective view showing a state where the drum developing unit is disengaged from the electrophotographic color printer main body. (A) is a perspective view of a head cleaner according to the present invention. (B), (c), (d) is a side view of the head cleaner according to the present invention. (C) shows a modification in which the cross-sectional shape of the flexible support member is a quadrangle, and (d) shows a modification in which the cross-sectional shape of the flexible support member is a trapezoid. (Embodiment). It is a perspective view explaining the attachment position and attachment state of a head cleaner (embodiment). It is a figure which shows the state which a head cleaner contact | abuts to an LED head lens and cleans, when inserting a drum developing unit. (A) shows the state immediately before insertion, (b) shows the state during insertion (during cleaning), (c) shows the state before insertion is completed and the head is raised, (d) shows The state when the insertion is completed and the head is raised is shown (embodiment). (A) is a figure which shows a deformation | transformation of the cleaner contact part at the time of insertion. (B) is a figure which shows a deformation | transformation of the cleaner contact part at the time of extraction (embodiment). (A) is a perspective view of the conventional head cleaner. (B) is the figure which looked at the conventional head cleaner from the side (conventional). It is a perspective view explaining the attachment position and attachment state of a head cleaner (conventional). It is a figure which shows the state which a head cleaner contact | abuts to an LED head lens and cleans, when inserting a drum developing unit. (A) shows a state immediately before insertion, (b) shows a state during insertion (during cleaning), and (c) shows a state when insertion is completed (conventional).

《Explanation of concepts and terms》
Hereinafter, definitions and explanations of concepts and terms used in the present invention will be given.
The LED head is a member serving as an emission port that emits light to form an image on the photosensitive drum.
The LED head lens is a lens that images light emitted from the LED head on a photosensitive drum.
Here, the head cleaner refers to a member that cleans the LED head lens.
The drum developing unit is a replacement part provided with a head cleaner for cleaning the LED head (lens).
The flexibility is a property that can bend.
The contact angle is an angle formed by the direction in which the head cleaner advances and cleans, and the head cleaner (the portion of the cleaner base to which the cleaner contact portion is attached).

<< About the point where the present invention is different from the past >>
In the background art section, a conventional general electrophotographic color printer (image forming apparatus) has been described with reference to FIGS. The present invention is different from the conventional general electrophotographic color printer only in that the shape of the head cleaner, the bending angle, and the support member are newly provided, and other parts are the same as the conventional one.
That is, the head cleaner of the present invention includes a cleaner base, a flexible support member, and a cleaner contact portion. The cleaner base is a member made of a flexible film bent at an acute angle such that the contact angle with the LED head lens becomes an acute angle. The flexible support member is a member provided at the bent portion so as to maintain the contact angle of the cleaner base. The cleaner abutting portion is a flexible member attached to the side of the cleaner base that abuts on the LED head lens so that a portion surrounding the cleaner base and a portion not surrounding the cleaner base can be formed.
And this head cleaner was provided in the part close | similar to the LED head lens of the back | inner side of the drum developing unit to insert / extract.
There are two points that differ from the conventional one. First, the cleaner base is used by bending it at an acute angle. Second, a flexible support member is provided so as to keep the angle of the bent portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view of an electrophotographic color printer (image forming apparatus) 1 according to the present invention. The electrophotographic color printer 1 transfers the three color and black toner images obtained on the photosensitive drum by the electrophotographic method onto a transfer belt, and then secondarily transfers them onto the printing paper accommodated in the paper feed cassette 25. The printing paper after printing, which is fixed by applying heat and pressure by the fixing device, is discharged to the discharge tray 37. When the front door 42 is opened, parts such as a toner unit, a drum developing unit, and a fixing unit are provided as parts that can be replaced by the user, and an old part is extracted by simple operation and a new part is inserted. It is configured to be able to.

FIG. 2 shows a state where the front door 42 of the main body of the electrophotographic color printer 1 is opened. Four drum developing units 2 (three colors and black) are mounted, and the four LED heads 3 are lifted and close to the photosensitive drum 2a provided in the drum developing unit 2 so that exposure is possible. Yes. This is shown by the fact that the four stagnations 52 are horizontal.
As described above, the drum developing unit may be a unit of a head cleaner alone, or a cleaner unit in which the head cleaner and waste toner discharge from the photosensitive drum are set. A unit including a photosensitive drum is also conceivable. Here, an example in which a head cleaner is provided in a drum developing unit including a photosensitive drum will be described.

FIG. 3 is a perspective view showing a state where the drum developing unit 2 is disengaged from the main body of the electrophotographic color printer 1.
The unit housing 16 is a portion that abuts when engaging with the main body of the electrophotographic color printer 1. Here, an example is shown in which the drum developing unit 2 is provided with a charging roller 3, a photosensitive drum 2a, and the like. The unit front cover 54 is provided with a knurling 52 so as to be rotatable. An alignment position display mark 53 is provided at one end of the stagnation 52, and the stagnation 52 is directed to a position that matches an unlock position display mark 56 provided on the upper side of the unit front cover 54. In this state, the LED head 3 provided on the main body side is at a position away from the photosensitive drum 2a.

  As shown in FIG. 3, when the drum developing unit 2 is disengaged from the main body of the electrophotographic color printer 1, the alignment position display mark 53 is in a position that matches the unlock position display mark 56. As shown in FIG. 5, the alignment position display mark 53 is in a position that matches the lock position display mark 55 when engaged with the main body. In this state, the LED head 3 is lifted up and close to the photosensitive drum 2a so that exposure is possible. A mechanism that allows the LED head 3 to be raised and lowered is provided on the back side of the unit front cover 54.

  FIG. 4 shows the shape and structure of the head cleaner 7 according to the present invention. The head cleaner 7 includes a cleaner base 7a, a cleaner contact portion 7b, and a flexible support member 7c. The cleaner base 7a is made of a flexible rectangular plate-like member, and can be made of, for example, a PET (polyethylene terephthalate) film. For example, Lumirror (trademark of Toray) provided by Toray Industries, Inc. can be used as the PET film. This PET film is formed into a rectangle, and is bent in the middle thereof to form a drum developing unit mounting portion 7a1 and a bent portion 7a2. The bending angle, that is, the angle formed between the drum developing unit mounting portion 7a1 and the bent portion 7a2 is an acute angle, preferably 40 degrees to 50 degrees. Then, when attached to the drum developing unit in the direction described later, the contact angle with the LED head (lens) becomes an acute angle (40 degrees to 50 degrees). Here, the contact angle is an angle formed by the direction in which the drum developing unit 2 is inserted (direction in which the cleaner advances) and the bent portion 7a2. Assuming that the insertion direction of the drum developing unit and the drum developing unit mounting portion 7a1 are parallel, the bending angle of the cleaner base 7 and the contact angle of the head cleaner 7 when inserting the drum developing unit are as follows: , Match.

  As shown in FIG. 4, a cleaner contact portion 7b is provided at the tip of the bent portion 7a2 of the cleaner base 7a of the head cleaner 7. The cleaner abutting portion 7b is attached so that a flexible soft member, for example, a rectangular member made of felt is bent by 180 degrees in the middle thereof and the tip of the cleaner-based bent portion 7a2 is sandwiched therebetween. The attachment method uses, for example, an adhesive. At this time, a base-equipped portion 7b1 where the cleaner contact portion 7b sandwiches the bent portion 7a2 and a base-free portion 7b2 which is not sandwiched are configured. The baseless portion 7b2 is flexibly and softly deformed by not sandwiching the cleaner base. This is to avoid a collision with the LED head (lens) mentioned in the problem of the prior art.

  The flexible support member 7c is made of, for example, a sponge, and has a shape in which a pentagonal column is laid down as shown in FIG. 4B, a shape in which a quadrangular column is laid down side by side in FIG. The cross section shown in FIG. 4 (d) can be made to lie next to a trapezoidal quadrangular prism. By bending the flexible support member 7c between the bent portion 7a2 of the cleaner base 7a and the drum developing unit mounting portion 7a1, the bending angle can be stably maintained. When the bent portion having an acute angle shape is constituted only by the cleaner base 7a, it may be restored by the stiffness of the material to return to the original right angle shape or obtuse angle shape, which is unstable in shape.

  As described above, the cleaner base is bent at an acute angle, the bending angle is maintained by the flexible support member, and the portion without the base is provided at the tip of the cleaner abutting portion, thereby improving the cleaning effect and the prior art. The structure avoids the collision with the LED head mentioned in the problem.

  FIG. 5 shows a position where the head cleaner 7 is attached to the drum developing unit 2. As for the pasting position, there is no change from the conventional one described in the prior art. A head cleaner 7 is attached to the bottom of the drum cover 5 that covers the photosensitive drum 2a. FIG. 5 is a view in which the rear side of the drum developing unit 2 (the portion that becomes the head when inserted into the main body) is turned upside down as in FIG. 9. Therefore, in this state, the head cleaner 7 faces upward. However, when the head cleaner 7 is inserted into the main body, the head cleaner 7 faces downward, and the LED head (lens) positioned directly below the photosensitive drum 2a is placed. to clean up.

FIG. 6 shows a cleaning mechanism of the head cleaner 7. As described above, the difference from the prior art is only the head cleaner, and the basic structure is the same as the conventional one.
Since the cleaner base of the head cleaner 7 is bent at an acute angle, it becomes easier to insert the head cleaner 7 during the insertion shown in FIG.
FIG. 6B shows a state where the head cleaner 7 is cleaning the LED head (lens) during insertion. The cleaner 7 advances from left to right in FIG. 6B, and the contact angle with the LED head lens 6 is an acute angle (preferably 40 to 50 degrees).

FIG. 6C shows a state immediately after the LED head 3 is lifted (close to the photosensitive drum) when the insertion is completed. Writing in parenthesis (before pulling out) indicates that this state is also obtained when pulling out after use. When the insertion of the drum developing unit 2 in FIG. 6C is completed and the LED head 3 is about to rise, the head cleaner 7 is in an acute angle state. The support member 7c is crushed and deformed in a direction in which the bending angle approaches 0 degrees.
When the drum developing unit 2 is pulled out, that is, when the drum developing unit 2 is pulled out, as shown in FIG. 6C, the LED head lens 6 and the head cleaner 7 are over at the baseless portion 7b2 (felt only portion). Since it is wrapped, only the felt of the head cleaner 7 can be deformed and the drum developing unit 2 can be pulled out. At this time, the baseless portion 7b2 is made of a soft member called felt as described above, and is flexibly deformed, so that there is no fear of damaging the LED head lens 6.

  FIG. 6D shows a state in which the LED head 3 is raised to a fixed position where the photosensitive drum 2 a of the drum developing unit 2 can be exposed. At this time, the head cleaner 7 is nearly bent by the LED head 3 and is folded without collision. Here, the force for raising the LED head 3 is sufficiently larger than the restoring force of the flexible support member 7 c of the head cleaner 7, so that the position of the LED head 3 is not affected at all.

  FIG. 7A shows a state in which the baseless portion 7b2 of the cleaner contact portion 7b of the head cleaner 7 at the time of insertion is deformed and contacts the LED head lens 6. FIG. FIG. 7B shows a state in which the non-base portion 7b2 of the cleaner contact portion 7b of the head cleaner 7 at the time of removal is deformed and contacts the LED head lens 6. As can be seen by comparing FIGS. 7 (a) and 7 (b), the side that contacts when the baseless portion 7b2 is inserted is different from the side that contacts when the connector is removed. Therefore, effective cleaning is possible because cleaning is performed on a surface that is not soiled during insertion and removal.

  As described above, the present invention can provide a function of automatically cleaning the LED lens by inserting and removing the drum developing unit without the user being aware of the cleaning in the LED cleaning in the electrophotographic printer. Further, by using the cleaner of the present invention, it is possible to provide a mechanism free from defects such as poor focus, poor insertion / extraction, and dropout for the LED head.

Although several embodiments of the present invention have been described, the present invention is included in the invention described in the claims and the equivalents thereof. Hereinafter, the invention described in the scope of claims of the present application will be appended.
[Appendix 1]

A cleaner base made of a flexible film bent so that the contact angle with the LED head lens becomes an acute angle;
A flexible support member provided at a bent portion of the cleaner base so as to maintain the contact angle of the cleaner base;
A flexible cleaner contact portion attached to a side of the cleaner base that contacts the LED head lens;
A head cleaner with
A drum developing unit, characterized in that the drum developing unit is provided at a portion positioned at the head in the inserting direction of the drum developing unit to be inserted and removed.
[Appendix 2]

2. The drum developing unit according to claim 1, wherein the cleaner base has a bending angle of 40 to 50 degrees.
[Appendix 3]

The drum developing unit according to appendix 1 or 2, wherein the cleaner base is made of a PET film.
[Appendix 4]

The drum developing unit according to any one of appendices 1 to 3, wherein the flexible support member is made of sponge.
[Appendix 5]

The drum developing unit according to any one of appendices 1 to 4, wherein the cleaner contact portion is made of felt.
[Appendix 6]

6. The drum developing unit according to any one of appendices 1 to 5, wherein the cleaner contact portion is attached so as to form a portion surrounding the cleaner base and a portion not surrounding the cleaner base.
[Appendix 7]

  An image forming apparatus using the drum developing unit according to any one of appendices 1 to 6.

  The present invention can be applied to a drum developing unit of an electrophotographic printer (image forming apparatus), particularly a drum developing unit close to an LED head, for example, a drum developing unit including a photosensitive drum.

1 Electrophotographic color printer (image forming device)
2 Drum development unit 2a Photosensitive drum 3 LED head 5 Drum cover 6 LED head lens 7 Head cleaner 7a Cleaner base 7a1 Drum development unit mounting portion 7a2 Bending portion 7b Cleaner contact portion 7b1 Base portion 7b2 Base-free portion 7c Flexible Support member 12 charging roller 14 developing device 16 unit housing 25 paper cassette 37 paper discharge tray 42 front door 52 squeeze 53 alignment position display mark 54 unit front cover 55 lock position display mark 56 unlock position display mark 97 head cleaner (Conventional)
97a Cleaner base (conventional)
97b Cleaner contact part (conventional)

Claims (4)

A drum developing unit to be inserted into and removed from the image forming apparatus,
The drum developing unit is
In order to clean the surface of the LED head lens for exposure, a head cleaner is provided at the head of the drum developing unit,
The head cleaner is
A flexible film fixed to the side surface of the drum developing unit, one of which is bent in two so that the central portion has an acute angle, faces the LED head lens when the drum developing unit is inserted and removed;
A flexible support member that is provided at the central portion of the flexible film and supports the flexible film inside the bent portion at an acute angle;
A contact member attached to the other tip of the bent flexible film,
A drum developing unit. The contact member has a drum-developing unit according to claim 1, wherein a portion of said flexible film is attached to the flexible film so that the core. Wherein the flexible film is a PET film, the flexible support member is made of sponge, the drum development unit according to claim 1 or 2, wherein the contact member is characterized in that it consists of felt. An image forming apparatus comprising the drum developing unit according to claim 1 so as to be insertable / removable.

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