JP2005148257A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce chatter or unpleasant sound caused by stick slip between an ITB and a cleaning blade. <P>SOLUTION: Under predetermined conditions, the mass of a metal plate serving as a holder of the cleaning blade is increased and also a V-shaped metal plate is attached to increase its rigidity. Further, a metal plate is also affixed, via a viscoelastic substance, to the side of the blade, which side is opposite to the joined side of the blade with the holder, thereby restraining chatter or unpleasant sound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a color image forming apparatus using an electrophotographic system, such as a printer, a copying machine, and a facsimile.

  As a color image forming apparatus, each color has a developing device for storing yellow, magenta, and cyan toners (in some cases, in addition to the above three colors, black toner). Alternatively, there are those arranged on a curve to develop an electrostatic latent image corresponding to each color developer. There are a direct transfer method and an intermediate transfer method as processes for superimposing a plurality of color images in a color image forming apparatus until a final visible image is obtained on a transfer material.

  In the direct transfer method, toner is transferred from the image carrier to the transfer material, so that the transfer environment due to the physical properties of the transfer material, the transferability of the transfer material, and the like affect the image quality. On the other hand, in the intermediate transfer method, since the transfer target in the step of superimposing the toner is always the same object (that is, the intermediate transfer member), a stable superimposed image can be obtained.

  A conventional cleaning device in an image forming apparatus using an intermediate transfer member will be described below with reference to FIG.

  First, the configuration of a conventional toner transport mechanism will be described. In the developing device 42, there is an image carrier 42a that carries an electrostatic latent image, and a toner image 51 adheres to the surface of the image carrier 42a according to the electrostatic latent image. The image carrier 42a is disposed adjacent to the intermediate transfer member 43. The image carrier 42a rotates in the A direction in the drawing, and the intermediate transfer member 43 rotates in the B direction in the drawing. When viewed from the image carrier 42a, a transfer device 44 is disposed adjacent to the intermediate transfer member 43 at the downstream side in the rotation direction of the intermediate transfer member 43, and rotates in the direction C in the drawing. Between the developing device 42 and the transfer device 44, a cleaning member 45 represented by a blade is disposed in contact with the intermediate transfer member 43, and the transfer residual toner 52 adhering to the surface of the intermediate transfer member 43 is removed. The surface of the intermediate transfer member 43 is scraped off and cleaned. A collection bottle 46 for collecting the cleaned transfer residual toner 52 is provided in the vicinity of the cleaning member 45, and a conveying device 41 is provided in the path between the cleaning member 45 and the collection bottle 46. The transport device 41 is composed of first transport means 41a that transports the toner 52 in the horizontal direction. When the motor 48 rotates, a screw or the like disposed immediately below the cleaning member 45 rotates. The toner 52 is conveyed to the entrance of the toner.

As the blade, a rubber blade is generally used. Actually, a very small amount of toner passes between the intermediate transfer member and the blade, and lubricates between the two. As a prior art, there is one having a cleaning blade on an intermediate transfer member. (For example, see Patent Document 1.)
JP 2000-321890

  However, as the material of the rubber blade is improved, the cleaning performance is improved, but the lubrication effect is reduced, and chatter vibration may occur from a portion where the intermediate transfer member and the blade are in contact with each other. This chatter vibration may cause resonance of the metal plate supporting the blade, resulting in unpleasant noise (blade squeal) for the user. The present invention aims to reduce such chatter vibration. It is said.

  In order to solve the above-mentioned problems, the invention described in the claims includes a blade that contacts the intermediate transfer member and cleans the intermediate transfer member, a support member that fixes and supports the blade, and an adhesive member interposed between the support member and the support member. A first damping material attached thereto, the blade is fixed to at least the first surface of the support member, and the first damping material is disposed on the back side of the first surface of the support member. The image forming apparatus attached to the second surface is characterized in that the blade has a second damping material that satisfies a condition in the range described.

  As described above, the following effects can be obtained in the color image forming apparatus using the intermediate transfer member.

  Since the cleaning blade of the intermediate transfer unit has the first and second vibration damping materials that satisfy the predetermined condition, noise such as squeal caused by stick-slip generated between the blade body and the intermediate transfer body can be suppressed, and the image In using the forming apparatus, the user can obtain a favorable environment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic sectional view of a color image forming apparatus using an electrophotographic system. The image forming apparatus A shown here is a laser beam printer that can form a four-color full-color image.

  The color image forming apparatus A, which forms an image through a process of fixing an image visualized with a developer (for example, toner) to a transfer material by heat or the like, is a drum-type electrophotographic as a first image carrier. Photosensitive drums 1Y, 1M, 1C, and 1BK are provided as photosensitive members. The photosensitive drum 1 (when these symbols are common to Y, M, C, and BK, these symbols are omitted) is driven to rotate, for example, counterclockwise by driving means (not shown).

  A charging device 2 that uniformly charges the surface of the photosensitive drum 1, an exposure device 3 that flashes a light source (for example, laser light or LED light) based on image information and forms an electrostatic latent image on the photosensitive drum 1, a photosensitive device A developing device 4 that develops toner by attaching toner to the electrostatic latent image on the drum 1 and an intermediate transfer unit 5 as a second image carrier to which the toner image on the photosensitive drum 1 is transferred are installed. The intermediate transfer member 5b in this case has a belt shape and rotates clockwise.

  The developing device 4 including the photosensitive drum 1 is fixedly disposed in parallel to the intermediate transfer unit 5. The developing device 4 that develops the electrostatic latent image on the photosensitive drum 1 has four developer accommodating portions that accommodate four color toners. Each developer accommodating portion is provided with a developer carrying roller 4a facing the photosensitive drum 1 when the developer accommodating portion faces the photosensitive drum 1 while carrying the toner as a developer on the surface. The electrostatic latent image on the photosensitive drum 1 can be developed by the developer carrying roller 4a.

  By sequentially transferring and superimposing the developed image on the photosensitive drum 1 to one intermediate transfer unit 5 facing each other, a single full-color developed image electrostatically adsorbed on the intermediate transfer member 5b is formed. In order to transfer toner from the photosensitive drum 1 to the intermediate transfer belt 5b, transfer means 5d for generating an electric bias with respect to the photosensitive drum is provided on the opposite side of the photosensitive drum.

  After one developed image is formed on the intermediate transfer member 5b, the intermediate transfer member 5b further rotates to a location E where the developed image is transferred to the transfer material. The transfer material in the transfer material storage box 6 is supplied to the transfer portion E by the paper feeding / conveying device 7 at a predetermined timing. In the transfer portion E, transfer means 5e for generating an electric bias for the transfer belt 5b is provided on the opposite side of the transfer belt 5b with the transfer material interposed therebetween.

  As described above, the toner image is collectively transferred to the transfer material by using the electrostatic attraction force. Further, in order to fix the toner image on the transfer material, the transfer material is conveyed to a fixing device. In the fixing device, heat and pressure are used to melt and fix the toner on the transfer material.

  The transfer material that has passed through the fixing device 8 is discharged to the paper discharge tray 10 by the transport unit 9.

  A curve 20 indicates a transfer material conveyance path.

  Next, the blade according to the present invention and the vicinity thereof will be described with reference to FIGS.

  As shown in FIG. 2, the blade of this embodiment includes a blade body 21 made of an elastic body such as rubber, a sheet metal 21b as a support member that stably supports the blade body 21a, and a blade of the sheet metal 21b. The first damping material 22 and the blade body 21a, which are fixedly supported on the back surface of the surface to which the body is bonded or welded, are attached to the downstream surface of the intermediate transfer body 5b in the moving direction (D in the figure). And a second damping material 23. Further, when configured as the intermediate transfer unit 5, only the edge portion 21c of the blade body 21a is in contact with the intermediate transfer body 5b.

  The first and second damping materials 22 and 23 will be described in detail with reference to FIGS.

  In the conventional case shown in FIG. 5, chatter vibration generated in the blade body 21a vibrates the support metal plate 21b, which is generated as sound. The chatter vibration at the contact portion between the blade body 21a and the intermediate transfer body 5b is generated because the intermediate transfer body 5b moves, and so-called self-excited vibration occurs.

  In order to suppress the vibration of the support metal plate 21b, a first damping material is fixed to the support metal plate 21b as a weight and a rigidity reinforcing member. The first damping material 22 is fixed to the back side where the blade body 21a is attached. The first damping material 22 is bent as shown in FIG. 3 to ensure its own rigidity. Experiments have confirmed that it is effective to make the longitudinal direction substantially the same as 21b. This is because, in this system, it has been experimentally known that the vibration mode is such that the longitudinal center portion is an antinode and both ends are nodes, and this is because the amplitude of the center portion is made as small as possible. In addition, the mass of the first damping material 22 is

Where m _{p is} the mass of the support member 21b, m _r is the mass of the blade body 21a, and m _{d1 is} the mass of the first damping material 22. The upper limit value 2.4 of m _p / m _d1 was set as described above due to space limitations of this system. The first damping material 22 is fixed to the support sheet metal 21b by an adhesive member 22a typified by a double-sided tape. In addition, the vibration damping effect can be obtained more by using a double-sided tape using a viscoelastic body instead of the double-sided tape.

The second damping material 23 includes a viscoelastic body 23a attached to the blade body 21a and a restraining body 23b that restrains the viscoelastic body 23a from above. Further, the second damping material 23 is disposed outside the transition region (between the fixed end and the free end l1) with respect to the length l0 of the blade body 21a in the direction in contact with the intermediate transfer member 5b. Yes. Thereby, the contact pressure of the blade body 21a does not differ depending on the presence or absence of the second damping material. Further, as shown in FIG. 4, the second damping material 23 is attached so as to cover the entire surface in the longitudinal direction w ₀ of the blade body 21a, that is, the direction orthogonal to the moving direction of the intermediate transfer body 5b. Thus, by providing the second damping material, the vibration energy generated and propagated between the intermediate transfer member 5b and the blade body 21a is contained in the viscoelastic body 23a sandwiched between the blade body 21a and the restraining body 23b. By efficiently converting to thermal energy and dissipating vibration energy, generation of vibrations that cause noise is suppressed. The mass of the second damping material 23 is set to the following range from the experimental results.

Where m _{p is} the mass of the support member 21a, and m _{d2 is} the mass of the second damping material 23.
The results of these experiments are summarized in Table 1.

1 is a schematic cross-sectional view of a color image forming apparatus according to the present invention. In the Example of this invention, the perspective view of a braid | blade and the intermediate transfer body vicinity is shown. In the Example of this invention, sectional drawing of a braid | blade and two damping materials is shown. In the Example of this invention, the relationship of the longitudinal direction of a braid | blade and a 2nd damping plate is shown. A conventional example near the blade and the intermediate transfer member is shown. The conventional example regarding the structure of a toner conveyance mechanism is shown.

Explanation of symbols

1, 42a Photosensitive drum (image carrier)
2 Charging device
3 exposure equipment,
4a Developer transfer roller
5 Intermediate transfer unit,
5b, 43 Transfer belt, intermediate transfer member
5d Primary transfer means
5e Secondary transfer means
5f Press material
6 Transfer material storage box
7 Paper feeder
8 Fixing device
9 Transport unit
10 Output tray
11 Access door
20 Transfer material transport path
21 blade
21a Blade body
21b (support) sheet metal
21c Edge part
22 First damping material
22a Adhesive member
23 Second damping material
23a Viscoelastic body
23b Restraint
24 rollers
41 Transport means
41a First transport means
42b Second transfer means
44 Transfer device
45 Cleaning material
46 Collection bottle
50 Transferred material
51 Toner image (toner)
52 Untransferred toner (toner)
A, B, C, D Movement direction

Claims (3)

There are an image carrier, an exposure device for forming an electrostatic latent image on the image carrier, a developing device for developing the electrostatic latent image on the image carrier, and at least a plurality of them, and the image In the process of transferring the development on the carrier to the transfer material, there is an intermediate transfer member for simultaneously carrying a plurality of images and transferring the images to the transfer material at once. The intermediate transfer member is attached to the intermediate transfer member. A blade body that abuts and cleans the intermediate transfer body; a support member that fixes and supports the blade body; and a first vibration damping member that is attached to the support member via an adhesive member. In the image forming apparatus, the blade body is fixed to at least the first surface of the support member, and the first damping material is attached to the second surface on the back side of the first surface of the support member.
A second damping material having a viscoelastic body and a restraining body for restraining the viscoelastic body satisfying the following conditions is disposed on the first surface side with respect to the intermediate transfer body, Image forming apparatus.
conditions

Where m _p : mass of the support member, m _r : mass of the blade body part, m _d1 : mass of the first damping material, m _d2 : mass of the second damping material.   The image forming apparatus according to claim 1, wherein the second vibration damping material is provided on the entire surface in a direction orthogonal to a moving direction of the intermediate transfer member of the blade. 2. The image forming apparatus according to claim 1, wherein the second damping material is disposed outside a transition region (between a fixed end and a free end) of the blade.

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