JP2016130784A - Cleaning device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize cleaning performance.SOLUTION: A cleaning device comprises: an image holding body that holds an image of a powder for image formation to which an external additive is added having a particle diameter smaller than the particle diameter of the powder, the image being formed on the surface of the image holding body by a forming unit that forms the image; a removing member that is in linear contact with the surface of the image holding body after the image has been transferred to rub the surface, and thereby removing an unnecessary material from the surface; and an application unit that receives supply of the powder from a supply source that supplies the powder to the forming unit, and applies the powder to the surface of the image holding body after the transfer of the image and before the removal of the unnecessary material.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cleaning device and an image forming apparatus.

  Conventionally, an image forming apparatus that forms an image with toner and a cleaner that cleans residual toner are known.

  For example, Patent Document 1 discloses a technique for improving the robustness of cleaning by providing means for supplying toner to a cleaning blade.

  For example, Patent Document 2 discloses a technique for supplying toner removed and stored from an image carrier to the image carrier using a cleaning roller.

  For example, Patent Document 3 discloses a technique for discharging toner removed from a cleaning unit to an image carrier under conditions where discharge products are likely to adhere.

JP 2013-167808 A JP 2011-013349 A JP 2009-294443 A

  An object of the present invention is to stabilize cleaning ability.

The cleaning device according to claim 1 is:
Image holding for holding an image of the powder formed on the surface by a forming device for supplying the powder to which an external additive having a particle size smaller than the particle size of the powder for image formation is added. A removal member that removes unwanted materials from the surface of the body by linearly contacting the surface after the image is transferred and rubbing the surface;
An applicator for supplying the powder from a supply source for supplying the powder to the former, and applying the powder to the surface of the image carrier after the transfer of the image and before removal of the unnecessary material;
It is provided with.

The cleaning device according to claim 2 is further provided by the cleaning device according to claim 1.
A mover that moves the applicator between a first position where the applicator contacts the surface of the image carrier and a second position spaced from the surface;
The applicator applies the powder at the first position, and stops applying the powder at the second position.

A cleaning device according to claim 3 is:
The applicator applies the powder when the density of the image is a first density, and the powder when the density of the image is a second density higher than the first density. It is characterized by stopping the application of the body.

An image forming apparatus according to claim 4
An image carrier for holding an image of the powder formed on the surface;
A former that is supplied with the powder to form the image;
A feeder for supplying the powder to which the external additive having a particle size smaller than the particle size of the powder has been added;
A transfer machine for transferring the image from the image carrier onto a recording medium;
A removing member that linearly contacts the surface of the image carrier after the image is transferred and rubs the surface to remove unwanted matter from the surface;
An applicator for supplying the powder to the surface of the image holding member after the transfer of the image and before the removal of the unnecessary material after the image is transferred;
It is provided with.

  According to the cleaning apparatus of the first aspect and the image forming apparatus of the fourth aspect, the cleaning ability is stabilized as compared with the case where the powder removed by the removing member is re-supplied to the image carrier.

  According to the cleaning device of the second aspect, the cleaning ability is further stabilized as compared with the case where powder is constantly supplied.

  According to the cleaning device of the third aspect, the cleaning ability is further stabilized as compared with the case where powder is constantly supplied.

1 is a schematic configuration diagram of a printer which is an embodiment of an image forming apparatus of the present invention. It is a figure which shows the detail of an applicator periphery.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a printer which is an embodiment of the image forming apparatus of the present invention.

  The printer 10 shown in FIG. 1 is a monochrome printer.

  An image signal representing an image created outside the printer 10 is input to the printer 10 via a signal cable (not shown). The printer 10 includes a control unit 11 that controls the movement of each component in the printer 10, and an image signal is input to the control unit 11. In the printer 10, an image is formed based on the image signal under the control of the control unit 11.

  The printer 10 includes a cylindrical photosensitive member 12 that rotates in a direction indicated by an arrow A. A charger 13, an exposure device 14, a developing device 15, a transfer device 16, and a photoconductor cleaner 17 are disposed around the photoconductor 12. The photoconductor 12 corresponds to an example of an image carrier according to the present invention, the developing unit 15 corresponds to an example of a forming unit according to the present invention, and the transfer unit 16 corresponds to an example of a transfer machine according to the present invention.

  The charger 13 charges the surface of the photoconductor 12, and the exposure device 14 exposes the surface of the photoconductor 12 in accordance with an image signal sent from the control unit 11 to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 15 to form a toner image.

  Here, the charger 13 may be a contact type equipped with a charging roller or the like, or may be a non-contact type equipped with a discharge wire or the like. The exposure device 14 may use laser light as a light source, or may use LED or the like as a light source. The developing device 15 may use a so-called two-component developer in which a toner and a carrier are mixed, or may use a developer mainly composed of toner.

  When the electrostatic latent image is developed by the developing unit 15, the toner in the developer in the developing unit 15 is reduced. Therefore, the printer 10 is provided with a supply unit 18 that supplies toner to the developing unit 15. The toner is supplied to the developing device 15 via the first supply path 181. The toner supplied from the supply device 18 is mixed with a so-called external additive, and the external additive has a particle size smaller than that of the toner particles and adheres to the surface of the toner particles. The feeder 18 corresponds to an example of a feeder according to the present invention.

  While a toner image is formed on the photoconductor 12, the paper P is conveyed in the direction of arrow B to a facing position between the transfer device 16 and the photoconductor 12 by a conveyance mechanism (not shown). Then, the toner image on the photoconductor 12 is transferred onto the paper P under the action of the transfer device 16. The external additive described above assists the separation of the toner particles from the surface of the photoreceptor 12 during the transfer of the toner image, so that the amount of toner (residual toner) remaining on the photoreceptor 12 after the transfer is small. The sheet P that has received the transfer of the toner image further proceeds in the direction of arrow B, and the toner image is fixed on the sheet P by being heated and pressed by a fixing device (not shown). As a result, an image composed of a fixed toner image is formed on the paper P.

  Residual toner on the photoconductor 12 is removed from the photoconductor 12 by the photoconductor cleaner 17. The photoconductor cleaner 17 is provided with a rubber cleaning blade 170, and the cleaning blade 170 has a long plate shape extending in the direction in which the cylindrical photoconductor 12 extends. The photoconductor 12 is in linear contact with one side extending along the photoconductor 12. For convenience, the one side in contact with the photosensitive member 12 may be referred to as an edge of the cleaning blade 170. Since the cleaning blade 170 is fixed while the photosensitive member 12 is rotating, the cleaning blade 170 rubs the surface of the photosensitive member 12 with an edge. Residual toner, external additives mixed in the toner, paper dust derived from the paper P, etc.) are scraped off and removed. Such a cleaning blade 170 corresponds to an example of a removing member according to the present invention.

  When unnecessary materials are scraped off the surface of the photoconductor 12 by the cleaning blade 170, a part of the scraped unnecessary materials stays along the edge of the cleaning blade 170 and is referred to as a toner dam or an external dam. A stagnant body is formed. The presence of the staying body surely scrapes off the unwanted matter, and the maintenance of the staying body is important for maintaining the cleaning ability by the cleaning blade 170. In particular, since the external additive has a small particle size, filling the gap between the edge and the surface of the photoconductor 12 or the gap between the toners prevents damage to the cleaning blade 170 due to wear and improves the cleaning ability of the cleaning blade 170.

  However, for example, when low density images are continuously formed, the cleaning blade 170 is damaged by friction with the photosensitive member 12 and the cleaning ability is reduced when the unwanted matter on the photosensitive member 12 is reduced and the staying member is reduced. There is a risk of doing. If the cleaning ability is reduced as such, streaky image defects may occur.

  1 is applied to the surface of the photoconductor 12 on the upstream side of the cleaning blade 170 (that is, after transfer of the toner image and before removal of residual toner). A container 171 is provided. The same toner as that supplied to the developing device 15 is supplied to the applicator 171 from the supply device 18 via the second supply path 182. This applicator 171 corresponds to an example of an applicator according to the present invention.

  FIG. 2 is a diagram showing details around the applicator.

  The applicator 171 includes a storage chamber 172 that stores toner, and a brush 173 that sends the toner from the storage chamber 172 to the photoreceptor 12 and applies the toner. The toner is supplied to the storage chamber 172 from the supply port 174 through the second supply path 182. Since the toner supplied in this way is the same toner as the toner supplied to the developing device 15, the same external additive is mixed therein. In the case where low density images are continuously formed, the external additive particles may be embedded in the surface of the toner accommodated in the developing device 15, and the toner or external additive in such a state If the staying body is formed by the cleaning blade 170, the role of preventing the cleaning blade 170 from being damaged may be insufficient. On the other hand, the toner applied to the surface of the photoreceptor 12 by the applicator 171 has an external additive attached to the surface, and the toner and the external additive in such a state form a staying body with the cleaning blade 170. By doing so, the cleaning blade 170 is prevented from being damaged by wear, and the cleaning ability of the cleaning blade 170 is maintained.

  Since the toner application by the applicator 171 is excessively consumed if it is always executed, it is preferably executed limitedly under conditions such as when low density images are continuously formed. . Therefore, in this embodiment, a tension spring 175 and a solenoid 176 are attached to the applicator 171, and the applicator 171 is normally separated from the photoreceptor 12 by the tension spring 175. Since the brush 173 of the applicator 171 applies toner by rotating with the photoreceptor 12, no toner is applied while the applicator 171 is separated from the photoreceptor 12. Further, since the applicator 171 is separated from the photoconductor 12, movement of unnecessary objects from the transfer device 16 side toward the cleaning blade 170 is not hindered.

  Based on the image data, the control unit 11 determines whether or not the operating condition is satisfied such that the formation of the low density image continues for a predetermined number or more, and when the operating condition is satisfied, the drive signal is sent to the solenoid 176. Send. The operating conditions include a condition that the average image density calculated for each predetermined number of sheets is lower than the reference density, a condition that the average image density calculated for each predetermined time is lower than the reference density, a standard There may be a condition that images having a density lower than the density continue for a predetermined number or more. Upon receiving the drive signal, the solenoid 176 pushes the applicator 171 to bring the applicator 171 into contact with the photoconductor 12, whereby the brush 173 rotates to apply toner to the surface of the photoconductor 12.

  Here, toner is applied by one applicator 171 over the entire length of the cleaning blade 170, but a plurality of applicators 171 are provided along the cleaning blade 170 (that is, in the depth direction of FIG. 2). Thus, each applicator 171 may be operated according to the image density in the area corresponding to each applicator 171.

  In the above embodiment, a monochrome printer is exemplified. However, the present invention may be applied to a color apparatus, or may be applied to a facsimile, a copier, or a multifunction machine.

  In the above-described embodiment, an apparatus for forming a toner image by electrophotography is exemplified. However, the forming device referred to in the present invention directly draws a toner image on an image holding member by an electrode array or the like. Also good.

  In the above embodiment, a transfer device that directly transfers a toner image from a photoconductor to a sheet is exemplified. However, the transfer device according to the present invention transfers an image from an image holding member to a recording medium via an intermediate transfer member. Indirect transfer may be used.

  In the above embodiment, paper is exemplified as the recording medium. However, the recording medium referred to in the present invention may be an OHP sheet or plastic paper.

DESCRIPTION OF SYMBOLS 10 Printer 11 Control part 12 Photoconductor 13 Charger 14 Exposure device 15 Developing device 16 Transfer device 17 Photoconductor cleaner 170 Cleaning blade 171 Coating device 18 Supply device 181 First supply path 182 Second supply path

Claims (4)

Image holding for holding an image of the powder formed on the surface by the forming device for supplying the powder to which an external additive having a particle size smaller than the particle size of the image forming powder is added. A removal member that removes unwanted matter from the surface by linearly contacting the surface of the body after the image is transferred and rubbing the surface;
An applicator for supplying the powder from a supply device for supplying the powder to the former, and applying the powder to the surface of the image carrier after the transfer of the image and before removal of the unnecessary material;
A cleaning device comprising: A mover that moves the applicator between a first position that contacts the surface of the image carrier and a second position that is spaced from the surface;
The cleaning device according to claim 1, wherein the applicator applies the powder at the first position and stops applying the powder at the second position.   The applicator applies the powder when the density of the image is a first density, and the powder when the density of the image is a second density higher than the first density. The cleaning apparatus according to claim 1, wherein the body application is stopped. An image carrier for holding an image of the powder formed on the surface;
A former that is supplied with the powder to form the image;
A feeder for supplying the powder to which the external additive having a particle size smaller than the particle size of the powder is added to the former;
A transfer machine for transferring the image from the image carrier onto a recording medium;
A removal member that linearly contacts the surface of the image carrier after the image is transferred and rubs the surface to remove unwanted matter from the surface;
An applicator for supplying the powder to the surface of the image holding body after the transfer of the image and before the removal of the unnecessary material after the image is transferred;
An image forming apparatus comprising:

Images