JP2009175323A - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device in which a developer regulating member is easily cleaned. <P>SOLUTION: The developing device 10 includes a housing in which developer is stored, a developer carrier 22 which rotates while carrying the developer on its surface and conveys the developer to the outside of the housing, and the developer regulating member 25 which regulates thickness of the developer conveyed by the developer carrier 22. The developing device 10 includes a cleaning member 29 which is held to be housed in the developer carrier 22 and which cleans the developer regulating member 25 by projecting from the developer carrier 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic developing device and an image forming apparatus.

  In an electrophotographic image forming apparatus, the surface of an image carrier (photosensitive member) is charged, the surface of the charged image carrier is selectively exposed to form an electrostatic latent image, and the electrostatic latent image is formed by a developing device. A developer (toner) is supplied to form a toner image on the image carrier.

  In the developing device, a roller-shaped developer carrying member carries a developer (toner) on its surface and rotates, thereby supplying toner to the image carrying member. The developing device generally has a plate-like developer regulating member that regulates the thickness of the developer (toner) layer in order to make the amount of the developer (toner) carried by the image carrier constant. Is.

  The temperature of the developer regulating member rises due to friction with the developer (toner), and the toner is easily fused. The toner fusion to the developer regulating member is not necessarily constant, and there is a partial variation. When the amount of developer (toner) supplied to the image carrier is biased, the image is uneven. was there.

Patent Document 1 describes a cleaning jig that scrapes off toner fused to a developer regulating member of a developing device. However, in recent downsized image forming apparatuses, it is difficult to secure a space for performing cleaning by inserting such a cleaning jig. In addition, it is necessary to take measures to prevent light fatigue of the image carrier and prevent the cleaning jig from coming into contact with the image carrier and being damaged. Further, there is a problem that the downtime of the image forming apparatus becomes longer by cleaning the developer regulating member using the cleaning jig.
JP 2004-20877 A

  In view of the above problems, an object of the present invention is to provide a developing device and an image forming apparatus that can easily clean a developer regulating member.

  In order to solve the above-described problems, a developing device according to the present invention includes a housing for accommodating a developer, a developer carrying member that carries the developer on a surface, rotates, and carries the developer out of the housing. A developer regulating member that regulates the thickness of the developer carried out by the developer carrying body, and is held so as to be housed in the developer carrying body, and protrudes from the developer carrying body. It shall have a cleaning member which can be cleaned.

  According to this configuration, the developer regulating member can be easily cleaned by rotating the developer carrying member by projecting the cleaning member or moving the projecting cleaning member on the developer carrying member.

  In the developing device of the present invention, the developer carrying member includes an exterior member that carries the developer, and an interior member that is disposed inside the exterior member and forms a magnetic field. , And may be accommodated between the exterior member and the interior member.

  According to this configuration, since the cleaning agent is stored using the gap between the exterior member and the interior member, the developing device does not increase in size.

  In the developing device of the present invention, the cleaning member may be able to contact the developer regulating member when protruding from the developer carrier.

  According to this configuration, the toner attached to the developer regulating member can be surely scraped off by bringing the cleaning member into contact with the developer regulating member.

  In the developing device of the present invention, the developing device further includes a supply member that supplies the developer contained in the housing to the developer carrier, and the developer carrier can be driven independently of the supply member. There may be.

  According to this configuration, since the developer regulating member can be cleaned by the cleaning member after the supply member is stopped and the developer is not on the developer carrier, the toner scraped off from the developer regulating member is developed. Reattachment can be prevented without staying on the agent regulating member.

  The image forming apparatus according to the present invention includes any one of the developing devices.

  According to this configuration, since the developer regulating member can be easily cleaned, unevenness due to variations in the amount of toner supply is unlikely to occur in the formed image.

  In the image forming apparatus of the present invention, the cleaning member may protrude from the developer carrier only during non-image formation.

  According to this configuration, since the cleaning member is accommodated at the time of image formation, the cleaning member does not vary the supply amount of the developer (toner).

  The image forming apparatus of the present invention further includes a supply member that supplies the developer contained in the housing to the developer carrier, and the developer carrier can be driven independently of the supply member. And a cleaning mode in which the driving of the supply member is stopped, the developer carrier is rotated, and the cleaning member is protruded and moved.

  According to this configuration, it is possible to maintain the image quality by cleaning the developer regulating member without the developer on the developer carrying member.

  According to the present invention, it is possible to maintain the uniform supply of the developer by the developing device by cleaning the developer regulating member by the cleaning member.

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 shows an image forming apparatus 1 according to the first embodiment of the present invention. The image forming apparatus 1 includes four developing units 2 that form images of different development colors using yellow (Y), magenta (M), cyan (C), and black (K) toners, and laser light to the developing units 2. Are transferred to the transfer belt 4, the transfer device 4, the transfer belt 4, the primary transfer roller 5 that transfers the toner image formed by the development unit 2 of each development color to the transfer belt 4 with electrostatic force The image forming apparatus includes a secondary transfer roller 6 that transfers the toner image onto the recording paper S with electrostatic force, and a fixing device 7 that heats the recording paper S and fixes the toner image.

  Each developing color developing unit 2 includes a rotating drum-shaped photoconductor (image carrier) 8 and a charger 9 for charging the photoconductor 8. An electrostatic latent image is formed by irradiation with laser light. Further, the developing unit 2 gradually removes the developing device 10 that forms toner images by attaching toner to the electrostatic latent image on the photoconductor 8, the cleaner 11 that scrapes off the toner on the surface of the photoconductor 8, and the photoconductor 8. And a static eliminator 12 for electrification.

  The transfer belt 4 is stretched over a drive roller 13 that is driven to rotate, a free roller 14, and a tension roller 15 that applies tension, and is rotated by the drive roller 13 in the direction of the arrow. Further, the image forming apparatus 1 includes a cleaner unit 16 that removes toner remaining on the surface of the transfer belt 4.

  The recording paper S is supplied to the paper supply unit 17, fed one by one by the supply roller 18, transported to the secondary transfer roller 6 by the transport roller 19, and discharged to the paper discharge unit 20 through the fixing device 7. .

  In the image forming apparatus 1, first, a Y color toner image developed on the photoreceptor 8 of the Y color developing unit 2 is transferred to the intermediate transfer belt 4, and the Y color toner image transferred by the rotation of the intermediate transfer belt 4 is transferred. The toner image of M color is formed on the photosensitive member 8 of the developing unit 2 of M color in accordance with the timing when the toner image moves onto the photosensitive member 8 of the developing unit 2 of M color, and the Y color of the intermediate transfer belt 4 is formed. The toner image of M color is transferred on the toner image. Similarly, a color image is formed by transferring the C-color toner image and the K-color toner image on the intermediate transfer belt 4 in a timely manner.

  FIG. 2 shows the configuration of the developing device 10. The developing device 10 rotates with the housing 21 containing the developer (toner) and the developer (toner) in the housing 21 supported on the surface, and the developer (toner) is carried out of the housing 21 to rotate the photosensitive member 8. A developer carrying member (developing roller) 22 for supplying toner to the toner, a stirring member 23 for stirring the developer (toner) in the housing, and a supply member 24 for feeding the developer (toner) to the developer carrying member 22 And a plate-like developer regulating member 25 that regulates the thickness of the developer (toner) carried on the developer carrying member 22 and keeps the amount of developer (toner) supplied to the photosensitive member constant.

  FIG. 3 shows the structure of the developer carrier 22 in detail. The developer carrier 22 includes a cylindrical exterior member 26 that carries the developer (toner), and a developer (toner) that is attracted by the magnetic force to be carried on the exterior member 26, and the housing is held on the exterior member. An interior member 27 that forms a magnetic field that is detached from the developer (toner) exterior member 26 that has returned to the interior by magnetic force, and is housed in a gap between the exterior member 26 and the interior member 27, As shown in FIG. 4, a large number of flexible rod-shaped cleaning members 29 that can respectively protrude from a large number of openings 28 formed in the exterior member 26, and a thin plate-shaped holding member 30 that holds the cleaning member 29. Have.

  The cleaning member 29 is made of, for example, a non-magnetic material such as a nylon thread having a diameter of several microns to several millimeters. The cleaning member 29 is held in a moquet shape by a holding member made of a non-magnetic material such as PET or aluminum. May be.

  As shown in FIG. 5, the exterior member 26 is formed with a band-shaped opening 28 over the entire width of the effective range for carrying the developer (toner), and each opening 28 is sealed by a cleaning member 29, respectively. Intrusion of the developer (toner) into the exterior member 26 is prevented. The opening 28 from which the cleaning member 29 protrudes may be provided over the substantially front surface of the exterior member 26.

  As shown in FIG. 4, when the exterior member 26 is rotated with the holding member 30 deformed and the cleaning member 29 protruding from the opening 28 of the exterior member 26, the cleaning member 29 contacts the developer regulating member 25. The toner adhering to the developer regulating member 25 can be scraped off. As a result, the developing device 10 is configured when the image quality is deteriorated when the thickness of the developer (toner) that the developer carrying member 22 is carried out of the housing 21 changes due to the adhesion of the toner to the developer regulating member 25. Alternatively, before the image quality deteriorates, the developer regulating member 25 is cleaned by the cleaning member 29 so that the amount of toner supplied to the photoreceptor 8 can be kept constant and the image quality can be maintained.

  Depending on the material and size of the cleaning member 29, even if the cleaning member 29 protrudes from the exterior member 26, it does not contact the developer restricting member 25 and protrudes from the developer restricting member 25 toward the developer carrier 22. It is also possible to scrape only the deposits that have grown.

  FIG. 6 illustrates a means for deforming the holding member 30 that holds the cleaning member 29. In this example, the outer peripheral portion of the holding member 30 is airtightly joined to the inner wall of the exterior member 26, and holds the cleaning member 29 so as not to protrude from the exterior member 26 in normal times. When compressed air is supplied to the inside of the developer carrier 22 via, for example, a hollow rotating shaft, the internal pressure of the developer carrier 22 is increased, and the holding member 30 is pressed toward the exterior member 26. Deform. That is, the holding member 30 is deformed according to a change in the internal pressure of the developer carrying member 22 and functions as a diaphragm that protrudes or houses the cleaning member 29.

  Further, as shown in FIG. 7, the cleaning member 29 may have a columnar shape having substantially the same cross-sectional shape as that of the opening 28. As shown in FIG. It may have an inverted conical shape that becomes thinner.

  Further, in the developing device 10 of this embodiment, it is desirable that the exterior member 26 of the developer carrier 22 can be driven independently of the stirring member 23 and the supply member 24. For example, a motor for driving the exterior member 26 and a motor for driving the stirring member 23 and the supply member 24 may be provided independently in the main body of the image forming apparatus 1, and the driving force of the motor for driving the exterior member 26 is provided. You may make it transmit to the stirring member 23 and the supply member 24 via the clutch which can be isolate | separated.

  In the developing device 10, a cleaning mode in which the driving of the stirring member 23 and the supply member 24 is stopped and the exterior member 26 is rotated can be provided. In this cleaning mode, since the developer (toner) is not supplied to the exterior member 26, it is possible to create a state where there is no developer (toner) on the surface of the exterior member 26. In this state, the cleaning member 29 is protruded, and further, the exterior member 26 is rotated, so that the toner and other deposits scraped off from the developer regulating member 25 are separated from the developer regulating member 25 and again the developer regulating member. It can be made difficult to adhere to the member 25.

  In the cleaning mode, after the developer regulating member 25 is cleaned, before the development is resumed, the exterior member 26 is rotated several times while the stirring member 23 and the supply member 24 are driven, thereby developing the surface of the exterior member 26. An agent (toner) layer is formed.

  Further, FIG. 9 shows a developer carrier 22 according to the developing device 10 of the second embodiment of the present invention. In addition, since the other structure of this embodiment is the same as 1st Embodiment, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  The developer carrier 22 of the present embodiment has an endless belt 32 that is stretched around pulleys 31 that are disposed at both ends of the developer carrier 22. The endless belt 32 forms a cylindrical surface integrally without forming a step between the endless belt 32 and the outer surface of the exterior member 26. The endless belt 32 holds a plurality of cleaning members 29 at a part thereof, and the pulley 31 rotates to move the cleaning member 29 in the width direction (longitudinal direction) on the surface of the developer carrier 22. And as shown in FIG. 10, it can be made to circulate so that the space between the exterior member 26 and the interior member 27 may move.

  As shown in FIG. 11, the developing device 10 according to the present embodiment stops the endless belt 32 in a state where the cleaning member 29 is accommodated in the space between the exterior member 26 and the interior member 27, and the exterior member 26 is By rotating, the toner can be supplied to the photoreceptor 8.

  In the present embodiment, the developing device 10 according to the present embodiment stops the exterior member 26 at a position where the endless belt 32 faces the developer regulating member 25 and rotates the endless belt 32, as shown in FIG. The cleaning member 29 can be moved along the developer regulating member 25 in the longitudinal direction of the developer carrying member, and the toner adhering to the developer regulating member 25 can be scraped off by the cleaning member 29.

  Also in the present embodiment, the driving of the agitating member 23 and the supply member 24 is stopped and the exterior member 26 is rotated so that there is no developer (toner) on the exterior member 26. It is preferable to scrape off the deposits on the member 25.

  Further, FIG. 13 shows an example of a mechanism for driving the pulley 31 to rotate the endless belt 32 of the present embodiment. This drive mechanism includes a driven bevel gear 33 that rotates together with the pulley 31, a drive bevel gear 34 that can be engaged with the driven bevel gear 33 and can drive the driven bevel gear 33, and a drive motor 35 that rotationally drives the drive bevel gear 34. The driving bevel gear 34 and the driving motor 35 are arranged on the image forming apparatus 1 so as to be movable integrally.

  When the exterior member 26 of the developer carrier 22 rotates, the drive mechanism retracts the drive bevel gear 34 together with the drive motor 35 to the main body of the image forming apparatus 1, and moves the drive bevel gear 34 from the driven bevel gear 33. Separated. However, when cleaning the developer regulating member 25, the endless belt 32 is opposed to the developer regulating member 25 and the exterior member 26 is stopped. Then, the developer regulating member 25 is moved together with the driving motor 35 to move the driving bevel gear 34 to the developer carrying member. 22 and engaged with the driven gear 33. Then, by starting the drive motor 35, the pulley 31 is rotated via the drive bevel gear 34 and the driven bevel gear 33, and the endless belt 32 is circulated. As a result, the cleaning member 29 appears from one end of the developer carrier 22 and moves along the developer regulating member 25 in a state of protruding toward the developer regulating member 25 to clean the developer regulating member 25.

  Since the present invention does not require manual work for cleaning the developer regulating member 25, there is no risk of accidentally damaging the photoreceptor 8, and the cleaning member 29 is housed inside the developer carrier 22. The light shielding of the photoconductor 8 is not impaired, and the light fatigue of the photoconductor 8 is not increased.

1 is a schematic diagram of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a developing device of the image forming apparatus in FIG. 1. FIG. 3 is a cross-sectional view of a developer carrier in a normal state of the developing device of FIG. FIG. 3 is a cross-sectional view of a developer carrier when the developing device of FIG. 2 is cleaned. FIG. 3 is a plan view of a developer carrier of the developing device in FIG. 2. FIG. 4 is an axial cross-sectional view illustrating a drive mechanism for a cleaning member of the developing device in FIG. 3. FIG. 4 is a detailed sectional view of a cleaning member of the developing device in FIG. 3. FIG. 4 is a detailed cross-sectional view of an alternative cleaning member of the developing device of FIG. 3. The perspective view of the developer carrier of the developing device of 2nd Embodiment of this invention. FIG. 10 is an axial cross-sectional view of the developer carrier of FIG. 9. FIG. 10 is a side sectional view of the developer carrying member of FIG. 9 in a normal state. FIG. 10 is a side sectional view of the developer carrying member of FIG. 9 when cleaning. FIG. 10 is a schematic view of a cleaning member driving mechanism in a normal state of the developer carrying member of FIG. 9. FIG. 10 is a schematic view of a cleaning member driving mechanism at the time of cleaning the developer carrying member of FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Developing unit 8 ... Photoconductor (image carrier)
DESCRIPTION OF SYMBOLS 10 ... Developing apparatus 21 ... Housing 22 ... Developer carrying body 23 ... Stirring member 24 ... Supply member 25 ... Developer control member 26 ... Exterior member 27 ... Interior member 28 ... Opening 29 ... Cleaning member 30 ... Holding member 31 ... Pulley 32 ... Endless belt 33 ... Follower bevel gear 34 ... Drive bevel gear 35 ... Drive motor

Claims (7)

A housing for containing the developer;
A developer carrying member that carries and rotates the developer on the surface, and carries the developer out of the housing;
A developer regulating member for regulating the thickness of the developer carried out by the developer carrying member;
A developing device, comprising: a cleaning member that is storably held in the developer carrying member and protrudes from the developer carrying member and capable of cleaning the developer regulating member. The developer carrying body includes an exterior member that carries the developer, and an interior member that is disposed inside the exterior member and forms a magnetic field,
The developing device according to claim 1, wherein the cleaning member is accommodated between the exterior member and the interior member.   The developing device according to claim 1, wherein the cleaning member can contact the developer regulating member when protruding from the developer carrying member. A supply member for supplying the developer contained in the housing to the developer carrier;
The developing device according to claim 1, wherein the developer carrying member can be driven independently of the supply member.   An image forming apparatus comprising the developing device according to claim 1.   The image forming apparatus according to claim 5, wherein the cleaning member protrudes from the developer carrier only during non-image formation. A developing device according to claim 4,
An image forming apparatus comprising: a cleaning mode in which the driving of the supply member is stopped to rotate the developer carrying member, and the cleaning member is protruded and moved.

Images