JP2018132672A - Toner image forming apparatus, charging device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the life of a charger including a charging roller by shifting a contact position in a rotation axis direction with the use of a change with time.SOLUTION: A toner image forming apparatus comprises: a bearing member 80 that rotatably supports an end of a chronologically moving member 70 that is at least one of an image holding body, a charging roller, and a cleaning roller; and a wearing member 81 that is arranged at a position held between an end face of the chronologically moving member 70 and an inner wall surface of the bearing member 80 and is rubbed with and worn by rotation of the chronologically moving member 70 to be reduced in dimension with time.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a toner image forming apparatus, a charging device, and an image forming apparatus.

  A charging member that rotates while contacting an image holding member to charge the image holding member is known. It is known that this charging member may cause a charging failure due to fixing of toner or the like over time.

  Here, in Patent Document 1, the cleaning member that cleans the charging roller in contact with the charging roller is swung in the axial direction in conjunction with the rotation of the charging roller, thereby suppressing adhesion of toner or the like to the charging roller. An image forming apparatus having a structure is disclosed.

  Patent Document 2 discloses an image forming apparatus having a structure in which toner or the like is prevented from adhering to the charging roller by reciprocating a predetermined amount of a cleaning member for cleaning the charging roller in the longitudinal direction of the charging roller. Has been.

  Further, Patent Document 3 includes a mechanism for contacting and separating the charging roll from the photosensitive drum, and a mechanism for moving the photosensitive drum in the rotation axis direction. The contact position of the photosensitive drum and the charging roll in the rotation axis direction. An image forming apparatus having a structure in which the adhesion of toner or the like to the charging roller is suppressed by changing the above is disclosed.

Japanese Patent Laid-Open No. 2002-162813 JP 2004-054141 A JP 2006-267952 A

    SUMMARY OF THE INVENTION An object of the present invention is to provide a toner image forming apparatus, a charging device, and an image forming apparatus that extend the life by shifting the contact position between members in the direction of the rotation axis by using a change with time.

Claim 1
An image holding member that holds a toner image through a process of charging, exposure, and development while rotating, and transfers the toner image onto a transfer target;
A charging member that rotates while contacting the image holding member to charge the image holding member;
A cleaning member that rotates in contact with the charging member to clean the charging member;
A bearing member that rotatably supports an end of a temporally moving member that is at least one of the image holding member, the charging member, and the cleaning member;
The sliding member is disposed at a position sandwiched between an end surface of the temporally moving member and an inner wall surface facing the end surface of the bearing member, and slides with a rubbing surface that is one of the end surface and the inner wall surface by rotation of the temporally moving member. A toner image forming apparatus comprising: a wear member that wears by rubbing and wears down in size over time.

  According to a second aspect of the present invention, in the toner image forming apparatus according to the first aspect of the present invention, the wear member is a member having a faster wear rate at a stage where the aging has progressed compared to the initial time.

  According to a third aspect of the present invention, the wear member includes a plurality of types of materials in which a material having a relatively slow wear rate is disposed on the wear surface side and a material having a relatively fast wear rate as the distance from the wear surface increases. The toner image forming apparatus according to claim 1, wherein the toner image forming apparatus is made of a material.

  According to a fourth aspect of the present invention, the wear member is formed in a shape such that the wear speed is relatively slow on the wear face side and the wear speed is relatively increased as the wear member is separated from the wear face. 4. The toner image forming apparatus according to any one of items 1 to 3.

  According to a fifth aspect of the present invention, the outer diameter of the wear member is constant in the direction of the rotation axis of the time-dependent moving member, and the inner portion extends from an end surface on the side away from the rubbing surface to an intermediate position toward the peripheral rubbing surface. The toner image forming apparatus according to claim 4, wherein the toner image forming apparatus has a hollowed shape.

  A toner image forming apparatus according to any one of claims 1 to 5, further comprising a pressing member that pushes the temporally moving member toward the wear member.

  The toner image forming apparatus according to claim 6, wherein the temporally moving member is disposed obliquely in a direction in which the temporally moving member is pushed toward the wear member side with respect to a member in contact with the temporally moving member. It is.

  An eighth aspect of the present invention is the toner image forming apparatus according to any one of the first to seventh aspects, further comprising a shavings reservoir for accumulating the shavings of the wear member.

Claim 9
A charging member that rotates and charges the image holding member while contacting the image holding member that holds the toner image through a process of charging, exposure, and development while rotating and transfers the toner image onto the transfer target;
A cleaning member that rotates in contact with the charging member to clean the charging member;
A bearing member that rotatably supports an end portion of an aging member that is at least one of the charging member and the cleaning member;
It is disposed at a position sandwiched between the end surface of the time-moving member and the inner wall surface facing the end surface of the bearing member, and slides on the end surface or the inner wall surface due to rotation of the time-moving member and wears over time. And a wear member for reducing the size of the charging device.

Claim 10
A toner image forming apparatus according to any one of claims 1 to 8;
A transport device for transporting paper;
A transfer device for transferring the toner image formed by the toner image forming device onto the conveyed paper;
An image forming apparatus comprising: a fixing device that fixes a toner image transferred on a sheet to the sheet.

  According to the toner image forming apparatus of claim 1, the charging device of claim 9, and the image forming apparatus of claim 10, the contact position in the rotation axis direction of the members moves due to wear of the wear member over time, and the contact position Compared with the case where the toner is not moved, the toner can be prevented from sticking to the charging member, thereby extending the life.

  According to the toner image forming apparatus of the second and third aspects, the time-dependent moving member can be moved at a speed corresponding to the degree of time.

  According to the toner image forming apparatuses of the fourth and fifth aspects, even a single material wear member can be moved at a speed corresponding to the degree of passage of time of the aging member.

  According to the toner image forming apparatus of the sixth aspect, the temporally moving member moves reliably as compared with the case where the force pressing the temporally moving member toward the wear member does not act.

According to the toner image forming apparatus of the seventh aspect, the temporally moving member reliably moves without providing a separate member such as a pressing member.
According to the toner image forming apparatus of the eighth aspect, the risk of malfunction due to scraping of the wear member is reduced.

1 is a schematic diagram of an image forming apparatus as an embodiment of the present invention. It is a schematic diagram of a charger. It is the schematic diagram which showed the temporal movement member and its bearing member structure. It is the figure which showed the 1st example of the wear member. It is the figure which showed the 2nd example of the abrasion member. It is the figure which showed the 3rd example of the abrasion member. It is the schematic diagram which showed the 2nd example of the temporal movement member and its bearing member structure.

 Embodiments of the present invention will be described below.

 FIG. 1 is a schematic diagram of an image forming apparatus as an embodiment of the present invention. The image forming apparatus 100 shown in FIG. 1 includes one embodiment of the toner image forming apparatus of the present invention and one embodiment of the charging apparatus of the present invention.

 The image forming apparatus 100 includes a paper feeding unit 110, an image forming unit 120, and a winding unit 130.

 The paper supply unit 110 is loaded with a long roll paper P1 wound in a roll shape. The roll paper P1 loaded in the paper supply unit 110 is moved in the direction indicated by the arrow X1 toward the image forming unit 120 by the rotation of the roll shaft 111 in the direction of arrow A and the rotation of the delivery roll 112 by a drive source (not shown). It is sent out as a continuous paper P in the direction.

 In the image forming unit 120, the continuous paper P that has been fed in the direction of the arrow X1 is transported in the direction of the arrow X2 by the transport member 121, and an image is formed on the continuous paper P in the meantime.

 The continuous paper P on which this image is formed is sent to the winding unit 130 in the direction of the arrow X3, and is driven to rotate in the direction of the arrow B by a driving source (not shown) via the buffer 132 for absorbing the speed difference. The rolled paper 131 is wound around the roll shaft 131.

 The image forming unit 120 includes four image carriers 11Y, 11M, 11C, and 11K that rotate in the direction of the arrow Y, respectively. Here, Y, M, C, and K mean yellow, magenta, cyan, and black colors. On these four image carriers 11Y, 11M, 11C, and 11K, toner images of toners of respective colors are formed through a toner image forming process described below. In the following, in the description common to each color, the symbols Y, M, C, and K representing the distinction of colors are omitted.

 Around each image carrier 11, each charger 12 and each developer 13 are provided. Each charger 12 charges each image carrier 11. Each developing device 13 develops the electrostatic latent image formed on each image carrier 11 with each color toner. Further, an exposure device 14 is provided above the four image carriers 11Y, 11M, 11C, and 11K. From this exposure device 14, each image light 11 is irradiated with each exposure light 141 modulated with image data corresponding to each color. Then, on each image carrier 11, each color toner image is formed by charging by each charger 12, forming an electrostatic latent image by irradiating each exposure light 141 from the exposure device 14, and developing by each developing device 13. The formed image holders 11 temporarily hold the formed toner images of the respective colors. Here, each charger 12 corresponds to an example of the charging device of the present invention, and a combination of the image carrier 11, the charger 12, the developing device 13, and the exposure device 14 is an example of the toner image forming device of the present invention. It corresponds to.

 Further, the image forming unit 120 is provided with an intermediate transfer belt 21. This intermediate transfer belt 21 is an endless belt that is supported by a plurality of rolls 22 and circulates in the direction of arrow Z through a path along the four image carriers 11.

 Each primary transfer roll 23 is provided at each position where the intermediate transfer belt 21 is sandwiched between each image carrier 11. Each toner image temporarily held on each image carrier 11 is transferred onto the intermediate transfer belt 21 by the action of each primary transfer roll 23. The toner image transferred onto the intermediate transfer belt 21 is conveyed in the direction of arrow Z by the intermediate transfer belt 21 and transferred onto the continuous paper P by the action of the secondary transfer roll 24.

 The toner image transferred onto the continuous paper P is conveyed to the continuous paper P and proceeds in the direction of the arrow X2, and is sandwiched between the heating roll 31 and the pressure roll 32 constituting the fixing device 30 to be heated and pressurized. Then, the toner image is fixed on the continuous paper P. As a result, an image composed of a fixed toner image is formed on the continuous paper P. As described above, the continuous paper P on which this image is formed is fed into the winding unit 130 and wound up to become the roll paper P2.

 The image forming apparatus 100 further includes a control unit 41 and an operation unit 41. The control unit 41 is responsible for overall control for realizing the above-described image forming process in the image forming apparatus 100. The control unit 41 receives and temporarily stores a print instruction including image data transmitted from an external device, controls the exposure unit 14 based on the image data, and stores the image in the exposure unit 14. Exposure light 141 corresponding to the data is generated.

 The operation unit 42 has a role of receiving an operation by the user and transmitting the user operation to the control unit 41. The control unit 41 controls the image forming apparatus 100 so that the operation according to the user operation transmitted from the operation unit 42 is executed.

 Here, the feature of the present embodiment is the structure of the charger 12, and the structure of the charger 12 will be described below.

  FIG. 2 is a schematic diagram of the charger 12. Although four chargers 12Y, 12M, 12C, and 12K are shown in FIG. 1, all of these chargers 12Y, 12M, 12C, and 12K have the same configuration. The symbols Y, M, C, and K representing colors are omitted.

  The charger 12 includes a charging roll 50 and a cleaning roll 60.

  The charging roll 50 is a member that charges the image carrier 11 while contacting the image carrier 11 rotating in the direction of arrow Y and rotating in the direction of arrow E. The cleaning roll 60 is a member that cleans the charging roll 50 by attaching toner or the like attached to the charging roll 50 while contacting the charging roll 50 and rotating in the direction of arrow F. Here, the image carrier 11, the charging roll 50, and the cleaning roll 60 correspond to examples of the image holding member, the charging member, and the cleaning member according to the present invention.

  Here, any one member of the image carrier 11, the charging roll 50, and the cleaning roll 60 is configured to move with time in the direction of the rotation axis as described below. Here, a member configured to move with time in the rotation axis direction among the image carrier 11, the charging roll 50, and the cleaning roll 60 is referred to as a “time-moving member”.

 FIG. 3 is a schematic diagram showing a member that moves with time and a bearing member structure thereof. Here, the illustration of the drive structure of the temporally moving member 70 is omitted. Alternatively, the temporally moving member 70 is a member that rotates following the rotation of an adjacent member that is in contact with the temporally moving member 70 (for example, the image carrier 11 when the temporally driving member 70 is the charging roll 50). is there.

 The time-dependent moving member 70 has a roll shape, and the shaft 71 protrudes from both ends in the rotation axis direction. Here, for the sake of convenience, the portion of the shaft 71 protruding to the left in FIG. 3 is referred to as the shaft 71a, and the portion protruding to the right is referred to as the shaft 71b.

 The shaft 71a is rotatably supported by one bearing member 80. In the bearing member 80, a wear member 81 is disposed coaxially with the rotation axis of the time-dependent moving member 70. The wear member 81 is fixed to the inner wall surface of the bearing member 80, and when the time-moving member 70 rotates, the wear member 81 and the end surface of the shaft 71a slide. The wear member 81 is gradually scraped over time by sliding with the end surface of the shaft 71a, and the length in the rotation axis direction is gradually reduced. The bearing member 80 is formed with a shavings reservoir 82 for storing the shavings of the wear member 81. The wear member 81 also accumulates the shavings in the shavings reservoir 82, thereby preventing the shavings from entering between the shaft 71a and the bearing member 80 and causing rotation failure of the temporally moving member 70.

  Further, the shaft 71b of the temporally moving member 70 protruding from the right side of FIG. 3 is rotatably supported by the other bearing member 90. A leaf spring 91 is disposed in the bearing member 90 to press the end surface of the shaft 71b. When the wear member 81 is pushed down by the leaf spring 91, the wear member 81 gradually moves in the direction of the arrow Z as the length of the wear member 81 decreases with time. As a result, the contact position between the temporally moving member 70 and the adjacent member in contact with the temporally moving member 70 is shifted in the direction of the rotation axis with time.

  That is, when the temporally moving member 70 is the charging roll 50 shown in FIG. 2, the charging roll 50 moves in the direction of the rotation axis with time, whereby the image carrier 11 and the charging roll 50, and the charging roll 50 and the cleaning roll 60. Is rubbed in the direction of the rotation axis, and adhesion of toner or the like to the charging roll 50 is suppressed.

 Further, when the temporally moving member 70 is the image carrier 11, the image carrier 11 and the charging roll 50 are rubbed in the rotation axis direction, and adhesion of toner or the like to the charging roll 50 is suppressed.

 Further, when the temporally moving member 70 is the cleaning roll 60, the cleaning roll 60 and the charging roll 50 are rubbed in the direction of the rotation axis, and adhesion of toner or the like to the charging roll 50 is suppressed.

 Next, the wear member 81 will be described. The wear member 81 may be a simple member such as a columnar shape made of a single material. However, if the device described below is devised, the amount of movement of the temporally moving member until the end of its life This is more effective because the length of the member that moves with time can be reduced accordingly.

 FIG. 4 is a view showing a first example of a wear member. The wear member 81A shown in FIG. 4 or the wear members 81B and 81C shown in FIGS. 5 and 6 described later are members that can be used as the wear member 81 shown in FIG.

 The wear member 81A shown in FIG. 4 is a member made of two types of materials having the same diameter, that is, a material 811A and a material 812A, which are bonded to each other. The shaft 71a (see FIG. 3) first slides with the material 811A to scrape the material 811A, and after all the material 811A is shaved, it slides with the material 812A. As an adhesive for bonding the material 811A and the material 812A, it is necessary that the material 811A and the material 812A are not peeled off and can be easily scraped by sliding with the shaft 71a.

 The material 811A is a material harder than the material 812A, and the speed of scraping by sliding with the shaft 71a is slower than that of the material 812A. When the charger 12 (see FIG. 2) is still new, it is not necessary to move the aging member 70 in the direction of the rotation axis, and the hard material 811A is scraped at a slow speed. Then, the time-dependent moving member 70 moves at a slow speed in the arrow Z direction shown in FIG. When the material 811A is shaved and the end surface of the shaft 71a starts to slide with the material 812A, the material 812A is softer than the material 811A, so the material 812A is shaved faster than the material 811A, and the temporally moving member 70 slides with the material 811A. Move at a faster speed than you used to. When the charger 12 has been operating for a long period of time, toner or the like is likely to adhere to the charging roll 50, so that the time-moving member 70 is moved at a slightly higher speed to prevent the toner or the like from adhering to the charging roll 50.

 FIG. 5 is a view showing a second example of the wear member.

 The wear member 81B shown in FIG. 5 is also composed of two materials 811B and 812B having the same diameter. These materials 811B and 812B are the same as the two materials 811A and 812A shown in FIG.

 Here, three protrusions 811Ba are provided on the surface of the material 811B facing the material 812B side. Further, three holes 812Ba into which the protrusions 811Ba are fitted are formed at positions corresponding to the three protrusions 811Ba on the surface of the material 812B facing the material 811B side. The wear member 81B shown in FIG. 5 is configured by fitting protrusions 811Ba and holes 812Ba, unlike the bonding in the first example shown in FIG. For this reason, generation | occurrence | production of the defect by peeling of adhesion | attachment is prevented. The number of protrusions 811Ba and holes 812Ba is not limited to three and may be any number. However, if only one is provided coaxially with the rotation axis, rotation may occur between the material 811B and the material 812B. Therefore, it is preferable to avoid providing only one coaxially with the rotation axis. In addition to this fitting, adhesion may be used in combination.

 The first example shown in FIG. 4 and the second example shown in FIG. 5 are both examples using two types of materials, but the moving speed of the temporally moving member is set using three or more types of materials. You may speed up gradually to three steps or more.

 FIG. 6 is a view showing a third example of the wear member.

 The wear member 81C shown in FIG. 6 has a cylindrical outer shape and is made of a single material. However, the wear member 81C is formed with a hollow portion 811C which is formed in a cylindrical shape on the side away from the shaft 71a (see FIG. 3).

 For this reason, in this wear member 81C, when the hollow portion 811C is not formed at the initial stage, the clogged portion is scraped at a slow speed, and this scraping reaches the portion where the hollow portion 811C is formed. Increases the speed at which it can be sharpened.

 In this way, by changing the shape in the direction of the rotation axis, the moving speed of the time-dependent moving member 70 may be increased when the time has elapsed.

 The wear member 811C of the third example shown in FIG. 6 is an example having a simple cylindrical hollow portion 8111C. For example, a conical hollow portion is formed, and the time-dependent moving member 70 of the time-varying member 70 increases as time passes. The moving speed may be gradually increased.

 FIG. 7 is a schematic view showing another example of the temporally moving member.

 In the case of the example shown in FIG. 7, the leaf spring 91 that presses the shaft 71b provided in FIG. 3 is not provided. Although not shown here, the structure is the same as that shown in FIG. 3 except that the leaf spring 91 is not provided. Further, FIG. 7 shows a roll-like adjacent member 150 with which the temporally moving member 70 contacts. The adjacent member 150 is, for example, the image holding body 11 when the temporally moving member 70 is, for example, the charging roll 50. The time-dependent moving member 70 is disposed so as to be a slightly inclined rotation axis with respect to the rotation axis of the adjacent member 150.

 Here, the temporally moving member 70 will be described as a member that is driven by the rotation of the adjacent member 150 and is driven to rotate.

 In this case, the temporally moving member 70 receives a force H in a direction perpendicular to the rotation axis of the adjacent member 150 from the adjacent member 150 due to the rotation of the adjacent member 150. This force H can be divided into a component force H1 in a direction perpendicular to the rotation axis of the temporally moving member 71 and a component force H2 of the temporally moving member 71 in the rotational axis direction. The component force H1 in the direction perpendicular to the rotation axis acts as a force for rotating the time-dependent moving member 70. On the other hand, the component force H2 in the rotational axis direction of the temporally moving member 71 acts as a force that pushes the temporally moving member 70 in the rotational axis direction. A wear member is arranged at the tip in the direction in which this component force H2 acts. By doing this, the time-dependent moving member 70 is pushed toward the wear member 81 side without separately providing a member for pushing the time-dependent moving member 70 in the direction of the rotation axis, such as the leaf spring 91 in the first example shown in FIG. be able to.

 In addition, when the time-dependent moving member 70 is a member that receives the rotational driving force and rotates the adjacent member 150 in a driven manner, the time-dependent moving member 70 receives a reaction force from the adjacent member 150. The direction is reversed. For this reason, it is necessary to arrange the history moving member 70 so as to be a rotational axis slightly inclined in the opposite direction with respect to the rotational axis of the adjacent member 150.

 Here, the example in which the wear member 81 is fixed to the bearing member 80 has been described. However, the wear member 81 is fixed to the shaft 71 a and is slid between the wear member 81 and the inner wall surface of the bearing member 81. It is good also as a structure. In this case, the wear member 81 is arranged in a direction that becomes a material that is difficult to cut (or a shape that is difficult to cut) on the side sliding with the bearing member 80.

 Here, the example in which the present invention is applied to the image forming apparatus 100 that forms an image on the continuous paper P shown in FIG. 1 has been described, but the present invention is applied to an image forming apparatus that forms an image on a cut sheet. Can also be applied as is.

 Although the present invention has been described with respect to an example in which the present invention is applied to an image forming apparatus that forms a color image, the present invention can also be applied to an image forming apparatus that forms a monochrome image.

11, 11Y, 11M, 11C, 11K Image carrier 12, 12Y, 12M, 12C, 12K Charger 13Y, 13M, 13C, 13K Developer 14 Exposure unit 21 Intermediate transfer belt 23Y, 23M, 23C, 23K Primary transfer roll 24 Secondary transfer roll 30 Fixing device 50 Charging roll 60 Cleaning roll 70 Aging member 71, 71a, 71b Shaft 80 Bearing member 81, 81A, 81B, 81C Wear member 811A, 811B, 812A, 812B Material 811Ba Protrusion 812Ba Hole 811C Hollow Part 82 shavings pool 90 bearing member 91 leaf spring 100 image forming apparatus 150 adjacent member

Claims (10)

An image holding member that holds a toner image through a process of charging, exposure, and development while rotating, and transfers the toner image onto a transfer target;
A charging member that rotates while contacting the image holding member to charge the image holding member;
A cleaning member that rotates in contact with the charging member to clean the charging member;
A bearing member that rotatably supports an end of a temporally moving member that is at least one of the image holding member, the charging member, and the cleaning member;
The sliding member is disposed at a position sandwiched between an end surface of the temporally moving member and an inner wall surface facing the end surface of the bearing member, and slides with a rubbing surface that is one of the end surface and the inner wall surface by rotation of the temporally moving member. A toner image forming apparatus, comprising: a wear member that wears by rubbing and wears down in size over time.   2. The toner image forming apparatus according to claim 1, wherein the wear member is a member having a higher wear rate at a stage where the aging has advanced than an initial stage of aging.   The wear member is composed of a plurality of types of materials in which a material having a relatively low wear rate is disposed on the wear surface side, and a material in which the wear rate is relatively increased as the wear member is separated from the wear surface. The toner image forming apparatus according to claim 1, wherein the toner image forming apparatus is a toner image forming apparatus.   The wear member is formed in a shape in which the wear rate is relatively slow on the wear surface side and the wear rate is relatively increased as the wear member moves away from the wear surface. The toner image forming apparatus according to any one of the above.   The wear member has a shape in which the outer diameter is constant in the direction of the rotation axis of the temporally moving member, and the inside is hollowed out from the end surface on the side away from the rubbing surface to the middle position toward the peripheral rubbing surface The toner image forming apparatus according to claim 4, comprising: a toner image forming apparatus;   The toner image forming apparatus according to claim 1, further comprising a pressing member that presses the temporally moving member toward the wear member.   The toner image forming apparatus according to claim 6, wherein the temporally moving member is disposed obliquely in a direction in which the temporally moving member is pushed toward the wear member side with respect to a member in contact with the temporally moving member.   8. The toner image forming apparatus according to claim 1, further comprising a shavings pool for collecting shavings of the wear member. 9. A charging member that rotates and charges the image holding member while contacting the image holding member that holds the toner image through a process of charging, exposure, and development while rotating and transfers the toner image onto the transfer target;
A cleaning member that rotates in contact with the charging member to clean the charging member;
A bearing member that rotatably supports an end portion of an aging member that is at least one of the charging member and the cleaning member;
It is disposed at a position sandwiched between the end surface of the time-moving member and the inner wall surface facing the end surface of the bearing member, and slides on the end surface or the inner wall surface due to rotation of the time-moving member and wears over time. And a wear member that reduces the size of the charging device. A toner image forming apparatus according to any one of claims 1 to 8;
A transport device for transporting paper;
A transfer device for transferring the toner image formed by the toner image forming device onto the conveyed paper;
An image forming apparatus comprising: a fixing device that fixes a toner image transferred onto a sheet onto the sheet.

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