JP2010181547A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device that reduces torque for rotating a developing roller and suppresses toner leak. <P>SOLUTION: A body stores toner. A developing roller 54 carries toner on its periphery. A regulating member 56 comes into press-contact with the developing roller 54, thereby regulating the thickness of a layer of toner carried by the developing roller 54 to a predetermined thickness. A reinforcing member 60 is the one for reinforcing a press-contact portion, which comes in press-contact with the developing roller 54 in the regulating member 56, and the reinforcing member 60 is disposed within the area R overlapping the press-contact portion in the regulating member 56. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developing device, and more particularly to a developing device including a developing roller that carries toner.

  A general developing device includes a main body, a supply roller, a developing roller, and a regulating member. The main body stores toner. The supply roller is rotatably attached to the main body. The developing roller carries the toner conveyed by rotating the supply roller on its peripheral surface. The regulating member is in pressure contact with the circumferential surface of the developing roller, and regulates the thickness of the toner layer formed on the circumferential surface of the developing roller to a predetermined thickness. The toner layer thus regulated to a predetermined thickness is conveyed to the photosensitive drum as the developing roller rotates. Then, a toner image is formed according to the electrostatic latent image formed on the peripheral surface of the photosensitive drum.

  By the way, in the developing device, there is a demand to rotate the developing roller with as little torque as possible. As a method for achieving such a requirement, for example, the force with which the regulating member is pressed can be reduced. Thereby, the sliding resistance between the developing roller and the regulating member is reduced, and the developing roller can be rotated with a small torque.

  However, if the force with which the regulating member is pressed against the developing roller is small, the toner may leak from the main body when the developing device is dropped. More specifically, when the developing device falls, the main body of the developing device is instantaneously elastically deformed by an impact. When the regulating member is pressed against the developing roller with a sufficient force, even if the main body is deformed, there is almost no gap between the developing roller and the regulating member. However, when the force with which the regulating member is pressed against the developing roller is small, a gap may be generated between the developing roller and the regulating member when the main body is deformed. As a result, the toner leaks from the gap to the outside of the main body.

  As a conventional developing device, for example, a developing device described in Patent Document 1 is known. In the developing device, a damping member is provided on the regulating member in order to prevent the toner layer from having a uniform thickness due to vibration of the regulating member. However, Patent Document 1 does not describe a configuration for preventing toner from leaking from the main body due to an impact at the time of dropping.

Japanese Patent Laid-Open No. 11-52721

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device that can reduce torque for rotating a developing roller and suppress toner leakage.

  A developing device according to an aspect of the present invention includes a main body that stores toner, a developing roller that carries the toner on a peripheral surface thereof, and the toner carried by the developing roller by being in pressure contact with the developing roller. A regulating member made of a plate-like member that regulates the thickness of the layer to a predetermined thickness, and a reinforcing member for reinforcing the press-contact portion that is in pressure contact with the developing roller in the regulating member, And a reinforcing member provided in a region overlapping with the pressure contact portion.

  According to the present invention, torque for rotating the developing roller can be reduced and toner leakage can be suppressed.

1 is a configuration diagram of an image forming apparatus including a developing device according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional structure diagram of a developing device. FIG. 4 is an enlarged view of the vicinity of a supply roller and a development roller of the development device. It is the figure which planarly viewed the regulating member from the direction of arrow A in FIG. It is an external appearance perspective view of a control member.

  A developing device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an image forming apparatus 10 including a developing device according to an embodiment of the present invention.

  As shown in FIG. 1, the image forming apparatus 10 includes a paper feed cassette 12, a paper feed roller 14, an image forming unit 15, a transfer device 32, a paper discharge roller pair 34, and a paper discharge tray 36. The paper feed cassette 12 stores a plurality of sheets P in a stacked state. The paper feed roller 14 takes out and conveys the paper P stored in the paper feed cassette 12 one by one.

  As shown in FIG. 1, the image forming unit 15 includes a developing unit 16, a photosensitive drum 18, a scanning optical device 20, a cleaner 22, a transfer belt 24, a driving roller 26, a driven roller 28, and a transfer roller 30. .

  The peripheral surface of the photosensitive drum 18 is charged by a charger (not shown). The scanning optical device 20 irradiates the charged peripheral surface of the photosensitive drum 18 with laser. Thereby, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 18.

  As shown in FIG. 1, the developing unit 16 includes a developing device 17 (17Y (yellow), 17M (magenta), 17C (cyan), 17K (black)) that is detachable from the image forming apparatus 10, and has an arrow. It can rotate in the direction of E. The developing device 17 applies toner to the photosensitive drums 18 to form toner images on the peripheral surfaces of the plurality of photosensitive drums 18. More specifically, the developing device 17 contains toner and is negatively charged by stirring the toner. Then, the developing device 17 conveys the toner to the vicinity of the photosensitive drum 18 by the developing roller. At this time, the negatively charged toner moves from the developing roller to the photosensitive drum 18 under the influence of the electric field due to the electrostatic latent image. As a result, a toner image is formed on the peripheral surface of the photosensitive drum 18.

  The transfer belt 24 is stretched between the driving roller 26 and the driven roller 28, and the toner image formed on the photosensitive drum 18 is primarily transferred. The cleaner 22 serves to collect toner remaining on the peripheral surface of the photosensitive drum 18 after the primary transfer. The drive roller 26 is driven by a motor (not shown) to drive the transfer belt 24. As a result, the transfer belt 24 conveys the toner image to the transfer roller 30.

  The transfer roller 30 faces the transfer belt 24 to form a nip portion N, and the toner image conveyed by the transfer belt 24 is transferred from the paper feed roller 14 to the paper P passing through the nip portion N. Secondary transfer.

  The sheet P on which the toner image is secondarily transferred is conveyed to the fixing device 32. The fixing device 32 fixes the toner image on the paper P by performing heat treatment and pressure treatment on the paper P. The paper discharge roller pair 34 discharges the paper P to the paper discharge tray 36. Printed paper P is placed on the paper discharge tray 36.

  Here, when the image forming apparatus 10 prints a color image composed of four colors Y, M, C, and K, the scanning optical device 20 first transfers the electrostatic image of the Y image to the photosensitive drum 18. Form. Next, Y toner is applied to the photosensitive drum 18 by the developing device 17Y, and a Y toner image is formed. The Y toner image is primarily transferred from the photosensitive drum 18 to the transfer belt 24. Thereafter, M, C, and K toner images are formed on the photosensitive drum 18 by the same procedure, and are superimposed on the transfer belt 24. As a result, a color toner image is formed. The color toner image is secondarily transferred to the paper P by the transfer roller 30 and fixed on the paper P by the fixing device 32.

  Next, details of the developing device 17 will be described with reference to the drawings. FIG. 2 is a sectional structural view of the developing device 17. FIG. 3 is an enlarged view of the vicinity of the supply roller 52 and the developing roller 54 of the developing device 17. 4 is a plan view of the regulating member 56 from the direction of arrow A in FIG. FIG. 5 is an external perspective view of the regulating member 56.

  As shown in FIGS. 2 and 3, the developing device 17 includes a main body 50, a supply roller 52, a developing roller 54, a regulating member 56, a holder 58, and a reinforcing member 60. The main body 50 is a container for storing the toner T. The supply roller 52 is rotatably mounted in the main body 50 and is made of, for example, conductive urethane foam. The supply roller 52 supplies the toner T to the developing roller 54 by being rotated in the direction of arrow C (counterclockwise).

  The developing roller 54 is a cylindrical member, and carries the toner T supplied by the supply roller 52 on the peripheral surface thereof. That is, a layer of toner T (hereinafter referred to as a toner layer) is formed on the peripheral surface of the developing roller 54. The developing roller 54 is rotated in the direction of arrow D (counterclockwise) to convey the toner T to the photosensitive drum 18.

  As shown in FIG. 3, the regulating member 56 is pressed against the developing roller 54 to regulate the thickness of the toner layer formed on the peripheral surface of the developing roller 54 to a predetermined thickness. More specifically, the regulating member 56 scrapes off excessive toner from the toner adhering to the peripheral surface of the developing roller 54. Hereinafter, the portion of the regulating member 56 that is in pressure contact with the developing roller 54 is referred to as a pressure contact portion. Further, as shown in FIGS. 3 and 4, a region that overlaps the pressure contact portion when the restriction member 56 is viewed in plan is called a region R. The regulating member 56 is a plate-like member having a rectangular shape with a thickness of 0.04 mm to 0.1 mm made of, for example, stainless steel (SUS301-CSP-H).

  The holder 58 is a member bent into a U-shape and plays a role of holding the regulating member 56. The holder 58 is made of a steel plate having a thickness of 1 mm to 2 mm, for example, and having a surface plated. The regulating member 56 and the holder 58 are fixed by, for example, spot welding. Further, as shown in FIG. 5, the holder 58 is attached to the main body 50 by screws 62a and 62b.

  The reinforcing member 60 is a plate-like member that reinforces the pressure contact portion that is in pressure contact with the developing roller 54 in the regulating member 56. As shown in FIGS. 3 and 4, the reinforcing member 60 is provided on the opposite side of the pressure contact portion of the regulating member 56 and in the region R. The reinforcing member 60 is made of the same material as the restricting member 56 and is attached to the restricting member 56 with an adhesive. The size of the regulating member 56 is, for example, a thickness of 0.1 mm and a width of 5 mm.

  According to the developing device 17 as described above, as described below, torque for rotating the developing roller 54 can be reduced and toner leakage can be suppressed. More specifically, in the developing device, as a method for reducing the torque for rotating the developing roller, it is possible to reduce the force with which the regulating member is pressed. Specifically, the thickness of the regulating member is reduced to reduce the strength of the regulating member. Thereby, the sliding friction between the regulating member and the developing roller is reduced, and the torque for rotating the developing roller can be reduced.

  However, if the force with which the restriction member is pressed is reduced, a gap may be generated between the restriction member and the developing roller when the developing device is dropped.

  Therefore, in the developing device 17, the reinforcing member 60 is provided so as not to protrude from the region R that overlaps the pressure contact portion of the restriction member 56 that is in pressure contact with the developing roller 54. Thereby, in the regulating member 56, the strength of the press contact portion is improved, and the strength of the other portions is not improved. That is, in the developing device 17, the strength of the pressure contact portion of the regulating member 56 is improved, so that deformation of the regulating member 56 due to an impact when the developing device 17 is dropped is suppressed. As a result, a gap is generated between the developing roller 54 and the restricting member 56, and toner leakage from the main body 50 is suppressed.

  On the other hand, in the regulating member 56, the strength between the portion fixed to the holder 58 and the press contact portion is almost the same as that of the regulating member not provided with the reinforcing member. Therefore, the force with which the regulating member 56 is pressed is almost the same as the force with which the regulating member not provided with the reinforcing member is pressed. Therefore, in the image forming apparatus 10, torque for rotating the developing roller 54 is reduced. As described above, in the developing device 17, it is possible to achieve both reduction in the rotational torque of the developing roller 54 and suppression of toner leakage. Incidentally, in the developing device 17, even if the force with which the regulating member 56 is pressed is about half (0.1 N / m) of the force with which the regulating member is pressed in the conventional developing device (0.2 N / m), it falls. Sometimes no toner leakage occurred.

  Although it is desirable that the regulating member 56 and the reinforcing member 60 are made of the same material, they may be made of different materials. However, it is desirable that the linear expansion coefficient of the reinforcing member 60 is 0.7 to 1.3 times the linear expansion coefficient of the reinforcing member 60.

  The present invention is useful for a developing device, and is particularly excellent in that the torque for rotating the developing roller can be reduced and toner leakage can be suppressed.

R region T toner 10 image forming apparatus 17, 17Y, 17M, 17C, 17K developing device 50 main body 52 supply roller 54 developing roller 56 regulating member 58 holder 60 reinforcing member

Claims (3)

A main body for storing toner;
A developing roller carrying the toner on the peripheral surface;
A regulating member made of a plate-like member that regulates the thickness of the toner layer carried by the developing roller to a predetermined thickness by being pressed against the developing roller;
A reinforcing member for reinforcing a pressure contact portion in pressure contact with the developing roller in the restriction member, the reinforcement member provided in a region overlapping the pressure contact portion in the restriction member;
Having
A developing device. The reinforcing member is provided on a surface of the regulating member opposite to the pressure contact portion;
The developing device according to claim 1. The reinforcing member is made of the same material as the regulating member;
The developing device according to claim 1, wherein:

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