JP2007011131A - Developing mechanism and image forming apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus with a means for reducing noises resulting from collision of developing units, in the image forming apparatus having a mechanism that separates developing units from a photoreceptor after formation of toner images on the photoreceptor, causes the developing units to collide with a wall face, and stops the developing units in predetermined positions. <P>SOLUTION: Buffers are attached to parts of the wall face with which the developing units collide and, thereby, energy transmitted to the wall face by collisions of the developing units is reduced by deformation of the buffers. Thus, the noises resulting from collisions of the developing units are reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to a developing mechanism that reduces an impact sound generated by a forward and backward movement of a developing device and an image forming apparatus including the developing mechanism.

  Some electrophotographic image forming apparatuses and the like form an electrostatic latent image on a photosensitive belt by an exposure device, and then form a toner image by bringing a developing device into contact with the photosensitive belt.

  As a mechanism for bringing the developing unit into contact with or separating from the photosensitive member, a mechanism for moving the developing unit using a cam as described in Patent Document 1, for example, is known.

  However, since this mechanism has a complicated structure and a large number of parts, a mechanism that moves the developing device with a simpler mechanism has been proposed. For example, when the developing device is brought into contact with the photosensitive member, the developing device is moved while compressing or pulling the spring installed in the printer body, and after the toner image is formed on the photosensitive member, the tensile force or compressive force of the spring is used. There is a mechanism for moving the developing device away from the photoreceptor. In this mechanism, in order to stop the developing device moving by the force of a spring at a predetermined position, the developing device is configured to collide with, for example, a printer cover and stop.

US Pat. No. 6,763,213

  However, a mechanism that uses a spring to pull the developing device away from the photoreceptor and collide with a wall surface such as a cover to stop the developing device has a problem that an impact sound is generated when the developing device collides with the wall surface.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing mechanism and an image forming apparatus having the developing mechanism that solve such problems.

  Specifically, an object of the present invention is to provide a developing mechanism that reduces impact noise generated when a developing device collides against a wall surface in a mechanism that causes the developing device to collide with a wall surface such as a cover and stops the developing device. An object of the present invention is to provide an image forming apparatus including the same.

  In order to achieve the above-described object, the present invention is directed to forming a toner image on the photosensitive member by bringing the developing device into contact with the photosensitive member, and then moving the developing device in a direction in which the developing device is retracted from the photosensitive member. In the image forming apparatus having a mechanism that causes the developing device to collide with the wall surface and stop at a predetermined position, a buffer is provided at a location where the developing device collides with the wall surface, and the energy transmitted to the wall surface by the collision of the developing device is provided in the buffering device. One feature is that it is reduced by the deformation of the vessel.

  Another feature of the present invention is that when a toner image is developed on a photosensitive member, the developing device is brought into contact with the photosensitive member, and then the developing device is moved away from the photosensitive member. And a wall surface portion for stopping the developing device moving in a direction away from the photosensitive member, a shock absorber made of a viscoelastic body is formed on the wall surface portion.

  Another feature of the present invention is that the shock absorber is made of a material having a logarithmic attenuation factor of 0.5 or more.

  Another feature of the present invention resides in that the shock absorber is constituted by a member having a truncated cone shape having a hollow portion and a cross-sectional shape of which is M-shaped.

  Another feature of the present invention resides in that the shock absorber has a truncated cone shape having a hollow portion, and the cross-sectional shape thereof is constituted by a trapezoidal member.

  Another feature of the present invention resides in that the shock absorber is composed of a bowl-shaped member.

  Another feature of the present invention resides in that a cut is provided at a location where the shock absorber comes into contact with the developing device.

  Another feature of the present invention is that a hole smaller than the contact surface is provided at the center of the surface of the shock absorber that contacts the developing device.

  Another feature of the present invention is that when a toner image is developed on a photosensitive member, the developing device is brought into contact with the photosensitive member and then moved forward and backward in a direction away from the photosensitive member. A first wall surface portion for stopping the developing device moving in a direction away from the photosensitive member, and a second wall surface disposed so as to have a predetermined distance from the first wall surface portion. And a resilient member disposed between the cushioning member and the second wall surface portion in a slidable manner in a hole provided in the first wall surface portion. Is equipped with a shock absorber.

  According to the present invention, since the impact energy transmitted to the wall surface when the developing device collides with the wall surface can be reduced by the shock absorber, the noise generated by the vibration of the wall surface by the collision energy can be reduced.

  In addition, by making the shock absorber a specific shape such as a thin frustoconical shape or a thin bowl shape, the shock absorber can have a damping effect that is greater than the damping characteristics of the material constituting the shock absorber. Further, the transmission of collision energy due to the collision of the developing device can be further reduced. For this reason, there is an effect that the noise generated by the vibration of the wall surface by the collision energy can be further reduced.

Example 1
First, an embodiment of an image forming apparatus according to the present invention will be described with reference to FIG.

  The image forming apparatus main body 1 such as a printer is driven in contact with the photosensitive belt 2 and the charger 4, the exposure device 5, the developing mechanism 6, and the photosensitive belt 2 disposed in the vicinity of the belt 2. It consists of a transfer body 3 or the like.

  The developing mechanism 6 includes a developing unit 64 that forms a black toner image, a developing unit 63 that forms a yellow toner image, a developing unit 62 that forms a magenta toner image, and a development that forms a cyan toner image. A container 61 is provided. A spring 65 is attached to each of the developing devices 61 to 64, and the developing devices 61 to 64 move back and forth with respect to the photosensitive member 2 by the compression and pulling force of the spring 65. Each of the developing devices 61 to 64 is configured such that the developing function is imparted or eliminated by controlling the bias voltage.

  On the other hand, a recording paper cassette 10 is detachably attached to the lower part of the photosensitive belt 2 and the exposure device 5, and the recording paper 16 is stored in the recording paper cassette 10. Adjacent to the recording paper cassette 10, a paper feeding device 20 including a paper feeding roller 200 and a peeling pad 201 is disposed. Further, along the running direction of the recording paper 16, a registration roller 12, a transfer roller 13, and a fixing device 14. Etc. are arranged.

  Next, the operation of the image forming apparatus according to the present invention will be described.

  When a print signal is sent to the image forming apparatus main body from an information processing device (not shown) (for example, a computer), the exposure device 5 is uniformly charged by the charger 4 based on the print signal. 2 is irradiated with laser light to form an electrostatic latent image.

  The exposure device 5 first forms an electrostatic latent image corresponding to the black toner image on the photosensitive belt 2. Thereafter, the spring 65 is compressed to move the black developing device 64 in the direction of the photosensitive belt 2, thereby bringing the black developing device 64 into contact with the photosensitive belt 2. Then, a black toner image is formed on the photosensitive belt 2 by the black developing device 64. After the toner image is formed on the photosensitive belt 2, the black developing device 64 is moved away from the photosensitive belt 2 by the restoring force of the pushed spring 65. The developing device 64 moved by the restoring force of the spring 65 collides with the inside of the cover 66 of the apparatus 1 and stops. The toner image formed on the photosensitive belt 2 is transferred and held on the surface of the intermediate transfer member 3 at the contact portion with the intermediate transfer member 3.

  On the other hand, the residual toner that is not transferred onto the photosensitive belt 2 is removed by the blade 8, and the electric charge remaining on the surface of the photosensitive belt 2 is removed by an erase lamp (not shown).

  After completing the process of returning the surface of the photosensitive belt 2 to the initial state in this manner, a cyan toner image is similarly formed on the surface of the photosensitive belt 2 and transferred and held on the intermediate transfer body 3. The same process is repeated for magenta and yellow colors, and toner images of four colors are superimposed on the intermediate transfer body 3 and held on this surface.

  In order to transfer the four color toner images formed on the surface of the intermediate transfer body 3 as described above to the recording paper 16, the paper feeding roller 200 of the paper feeding device 20 is rotated, and the recording paper 16 is removed from the peeling pad 201. And peel them one by one and send them out.

  After the recording paper 16 delivered by the paper supply roller 200 is conveyed to the registration roller 12 to correct the skew of the recording paper 16, the paper supply roller 200 is stopped. Next, the rotation of the registration roller 12 is started at a timing that aligns with the toner image on the intermediate transfer body 3. The transfer roller 13 is pressed from the back of the recording paper 16 at a timing when the leading edge of the conveyed recording paper 16 comes into contact with the intermediate transfer body 3, and the toner image on the surface of the intermediate transfer body 3 is statically placed on the recording paper 16. Electrotransfer.

  The recording paper 16 to which the toner image has been transferred is fixed on the recording paper 16 by passing between the heating roller 141 and the pressure roller 142 of the fixing device 14. The recording paper 16 on which the toner is fixed is peeled off from the heating roller 141 by a peeling means, guided by the paper discharge guide 17 and stacked on the upper surface of the paper discharge tray 510.

  Next, an embodiment of the developing mechanism according to the present invention will be described with reference to FIG.

  The developing mechanism 6 includes a black developing device 64, a yellow developing device 63, and a magenta arranged so as to be movable in a direction contacting the photosensitive belt 2 (right direction in the drawing) and a direction separating from the photosensitive belt 2 (left direction in the drawing). A developing unit 62 and a cyan developing unit 61 are provided. Each developing device 61 to 64 is stacked between two frames 30 extending in the vertical direction, and a spring 65 is provided between each frame 30 and the support member 67 on the side surface of each developing device 61 to 64. Is provided.

  On the other hand, a shock absorber 9A is provided on the surface of the main body cover 66 on the back surface of each developing device 61-64. The shock absorber 9A of the present embodiment is made of a rectangular parallelepiped member made of a viscoelastic material such as polyethylene, for example, and is attached to the surface of the cover 66 with which the developing devices 61 to 64 collide.

  Next, the operation of the shock absorber 9A in the developing mechanism configured as described above will be described. Taking the black developing device 64 as an example, when forming a toner image on the photosensitive belt 2, the spring 65 is compressed to bring the black developing device 64 into contact with the photosensitive belt 2.

  After the toner image is formed on the photosensitive belt 2, the black developing device 64 is moved away from the photosensitive belt 2 by the restoring force of the pressed spring 65. The developing device moved by the restoring force of the spring 65 collides with the shock absorber 9 </ b> A formed on the cover 66 and stops. At this time, the kinetic energy E of the black developing device 64 is obtained by deforming the vibration energy Ev that causes the cover 66 to vibrate and generate noise, the energy Ehc that is consumed by deforming the cover 66, and the shock absorber 9A. Transition to consumed energy Ehd. For example, Ehd increases as the deformation of the shock absorber 9A increases, and as the damping characteristic of the shock absorber 9A increases. As a result, vibration energy Ev is reduced, and noise generated when the black developing device 64 collides with the cover can be reduced.

  For example, FIG. 2 shows the relationship between the logarithmic attenuation rate δ, which is one of the methods for expressing the attenuation characteristics of the shock absorber 9A of this embodiment, and the operation sound (acoustic power level) of the printer 1 during color printing. As shown in FIG. 2, it can be seen that as the logarithmic attenuation rate δ, which is the attenuation characteristic of the shock absorber 9A, is larger, the operation sound of the printer 1 is lower and the noise reduction effect by the shock absorber 9A is greater.

  According to an experiment by the present inventor, it has been found that the use of a shock absorber having a logarithmic attenuation rate δ of δ> 0.5 can reduce the sound caused by the collision to a level that is not harsh. Accordingly, in a preferred embodiment of the present invention, a material having a characteristic of δ> 0.5 is used as a shock absorber member.

  In the present embodiment, the shock absorber is formed using a rectangular parallelepiped viscoelastic body. However, as described below, other shapes such as a truncated cone shape and a hemispherical shape may be used. Further, two or more types of viscoelastic bodies may be combined and stacked, for example, to form a shock absorber.

  The operation has been described above by taking the black developing device 64 as an example, but the same applies to the cyan developing device 61, the magenta developing device 62, and the yellow developing device 63, and redundant description is avoided in the description of the following embodiments.

(Example 2)
Next, a second embodiment of the developing mechanism according to the present invention will be described with reference to FIG. In this figure, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In the following description, a duplicate description is also avoided.

  In the present embodiment, a shock absorber 9B is provided on the surface of the cover 66 with which the developing devices 61 to 64 collide. The shock absorber 9B is made of a viscoelastic material such as polyethylene, for example, and has a thin frustoconical shape with a hollow portion as shown in FIG.

  For example, the kinetic energy E of the black developing device 64 when the black developing device 64 collides with the buffer 9B and stops is the vibration energy Ev that vibrates the cover 66 and generates noise as described above, and the cover 66. Transition is made to the energy Ehc consumed by the deformation, and the energy Ehd consumed by deforming the shock absorber 9B. For example, Ehd increases as the deformation of the shock absorber 9B increases, and as the damping characteristic of the shock absorber 9B increases. As a result, vibration energy Ev is reduced, and noise generated when the black developing device 64 collides with the cover can be reduced.

  For example, FIG. 5 shows the relationship of the operation sound (acoustic power level) of the printer during color printing when the shock absorber 9B of this embodiment made of polyethylene and the shock absorber 9A of the first embodiment are used. As shown in FIG. 5, the shock absorber 9B of the present embodiment has a lower operating sound than the rectangular shock absorber 9A made of the same material, and the noise reduction effect of the shock absorber 9B can be reduced. You can see that it is getting bigger.

  In other words, a hollow portion is formed in a member having a truncated cone shape, and a three-dimensional structure is formed so that the cross section is M-shaped, so that a damping characteristic larger than that of the material used for the shock absorber 9B is obtained. Thus, the damping effect of the shock absorber 9B can be enhanced. As a result, noise due to the collision of the developing devices 61, 62, 63, 64 can be reduced.

  In the above-described embodiment, the hollow portion is provided in the truncated cone-shaped member so that the cross section has a thin M shape, but a shock absorber 9C having a shape as shown in FIG. 6 can also be used. The shock absorber 9C is formed by making, for example, a cross-shaped cut at a portion of the shock absorber 9B that contacts the developing devices 61 to 64, that is, at the top of the truncated cone. With such a structure, the shock absorber 9C is more easily deformed when it collides with the developing devices 61, 62, 63, 64, the heat energy Ehd consumed by the deformation of the shock absorber 9C is increased, and the cover 66 is vibrated. This has the effect of reducing the vibration energy Ev that generates noise.

  When the shock absorber 9C having the cut is deformed by the collision of any of the developing devices 61, 62, 63, 64, the cut width is reduced so that the cut surfaces rub against each other. The vibration damping effect of the shock absorber 9C may be increased by friction between them.

(Example 3)
Next, a third embodiment of the developing mechanism according to the present invention will be described with reference to FIG.

  In the present embodiment, a shock absorber 9D made of a viscoelastic material such as polyethylene is formed on the surface of the cover 66, for example. The shock absorber 9D has a truncated cone shape having a hollow portion, and has a thin trapezoidal cross section as shown in FIG.

  Even when the shock absorber has such a shape, it is possible to provide a damping characteristic larger than the original damping characteristic of the material used for the shock absorber 9D, as in FIGS. As a result, even when the material of the shock absorber 9D is limited, the damping effect of the shock absorber 9D can be enhanced. For this reason, it is possible to reduce noise caused by the collision of the developing devices 61, 62, 63, and 64.

  Further, as in the shock absorber 9E shown in FIG. 9, for example, a cross-shaped cut is made at a location where the shock absorber 9D is in contact with any of the developing devices 61, 62, 63, 64, thereby developing devices 61, 62, 63. , 64 may be more easily deformed when they collide. In this case, the heat energy Ehd consumed by the deformation of the shock absorber 9E increases, and the vibration energy Ev that vibrates the cover 66 to generate noise further decreases.

  When the shock absorber 9E with the cut is deformed by the collision of any of the developing devices 61, 62, 63, 64, the width of the cut is reduced so that the cut surfaces rub against each other. The vibration damping effect by the shock absorber 9E may be increased by the friction caused by.

  Further, as in the shock absorber 9F shown in FIG. 10, for example, a circular hole may be provided in the trapezoidal upper portion of the shock absorber 9E that contacts any of the developing devices 61, 62, 63, and 64. In this way, when any of the developing devices 61, 62, 63, and 64 collides, the deformation becomes easier, and the vibration energy Ev that generates noise by vibrating the cover 66 can be further reduced.

Example 4
FIG. 11 is a schematic configuration diagram showing a fourth embodiment of the developing device mechanism according to the present invention.

  In the present embodiment, a shock absorber 9G made of a viscoelastic material such as polyethylene is formed on the surface of the cover 66 with which the developing devices 61 to 64 collide. As shown in FIG. 12, the shock absorber 9G has a hemispherical shape having a hollow portion, that is, a bowl shape.

  FIG. 13 compares the operation sound (acoustic power level) of the printer during color printing that occurs when the shock absorber 9G shown in the present embodiment is used with the case where the shock absorber 9A of the first embodiment is used. Show. As is apparent from this result, it is understood that the operation sound of the printer is reduced by adopting the shape as in the present embodiment, and the noise reduction effect by the shock absorber 9G is increased.

  That is, by adopting a three-dimensional structure as in this embodiment, it is possible to have a damping characteristic larger than that of the material used for the shock absorber 9G, and the material of the shock absorber 9G is limited. Even in this case, the damping effect of the shock absorber 9G can be enhanced. Therefore, noise due to the collision of the developing devices 61, 62, 63, 64 can be further reduced.

  Further, as in the shock absorber 9H shown in FIG. 14, for example, a cross-shaped cut is made in a location where the shock absorber 9G is in contact with any of the developing devices 61, 62, 63, 64, thereby developing devices 61, 62, The shock absorber is easily deformed when either 63 or 64 collides, and the heat energy Ehd consumed by increasing the heat by deforming the shock absorber 9H is increased, and the cover 66 is vibrated to generate noise. The vibration energy Ev to be generated may be reduced.

  At this time, when the buffer 9H having the cut is deformed by the collision of any of the developing devices 61, 62, 63 and 64, the width of the cut is reduced so that the cut surfaces rub against each other. You may make it the vibration damping effect by the buffer 9H increase by the friction between each other.

  Further, as in the shock absorber 9I shown in FIG. 15, for example, a circular hole is provided in the upper portion of the shock absorber 9H that contacts the developing devices 61, 62, 63, 64, and any of the developing devices 61, 62, 63, 64 is provided. The vibration energy Ev that causes the shock absorber to be easily deformed when it collides, increases the heat energy Ehd that is consumed by deforming the shock absorber 9I and generates heat by vibrating the cover 66. May be reduced.

(Example 5)
Next, a fifth embodiment of the developing mechanism according to the present invention will be described with reference to FIGS. This figure shows the structure of the shock absorber 9J provided between the black developing device 64 and the cover 66.

  In the present embodiment, the cover 66 with which the developing devices 61 to 64 collide is constituted by a first wall surface portion 66a and a second wall surface portion 66b, and a space portion is formed between both wall surface portions 66a and 66b. ing.

  A hole is formed in a part of the first wall surface portion 66a, and a cup-shaped member 69 having a thin cross section is fitted into the hole so as to be slidable. A spring 67 is provided in the hollow portion of the cup-shaped member 69, one end of which is fixed to the second wall surface portion 66 b and the other end is fixed to the bottom surface portion of the cup-shaped member 69. The cup-shaped member 69 is made of a resin such as polyethylene or polypropylene. The cup-shaped member 69 is provided with a collar-shaped portion 68 at the opening, and the collar-shaped portion 68 engages with the first wall surface portion 66a so that the cup-shaped member 69 protrudes toward the developing devices 61-64. It plays the role of a stopper so as not to.

  In this embodiment, for example, when the black developing device 64 is not in contact with the shock absorber 9J, as shown in FIG. 17A, the cup-shaped member 69 is pushed out by the spring 67, and a part thereof is the first wall surface. In this state, the surface protrudes from the surface of the portion 66a to the developing device 64 side.

  After the toner image is formed on the photosensitive belt 2, when the black developing device 64 collides with the shock absorber 9J as shown in FIG. 17-2, the spring 67 is compressed and the cup-shaped member 69 slides downward. .

  At this time, the kinetic energy E of the black developing device 64 includes vibration energy Ev that vibrates the cover 66 and generates noise, thermal energy Ehc that is consumed by deforming the cover 66 and becomes heat, and the buffer 9J. Transition is made to energy Ehd consumed by deforming, and energy Ehs consumed by deforming the spring 67. For example, Ehd increases as the deformation of the shock absorber 9J increases and as the damping characteristic of the shock absorber 9J increases. In addition, Ehs increases as the deformation of the spring 67 increases, for example. As a result, vibration energy Ev is reduced, and noise generated when the black developing device 64 collides with the cover can be reduced.

  By configuring the shock absorber 9J as described above, it is possible to have a damping characteristic larger than that of the material used for the shock absorber 9J. Even when the material of the shock absorber 9J is limited, The attenuation effect can be enhanced. As a result, noise due to the collision of the developing devices 61, 62, 63, 64 can be reduced.

  The description of this embodiment is based on the operation of the black developing device 64, but the same applies to the cyan developing device 61, the magenta developing device 62, and the yellow developing device 63.

  Further, in this embodiment, the cover 66 provided with the shock absorber 9J is doubled by forming the first wall surface portion 66a and the second wall surface portion 66b. However, for example, these may be two independent wall surfaces. .

  FIGS. 17A and 17B show a structure in which an independent buffer 9J is provided for each of the developing devices 61 to 64. However, as shown in FIG. 18, the buffer 9K common to the developing devices 61 to 64 is used. May be provided.

  The shock absorber 9K slidably fits a cup-shaped member 69 having a large opening common to the developing devices 61 to 64 to the first wall surface portion 66a, so that the second wall surface portion 66b and the cup-shaped member 69 are fitted. Four springs 67 corresponding to the developing devices 61 to 64 are provided on the bottom surface. Even when the shock absorber 9K having such a structure is used, noise caused by the collision of the developing devices 61 to 64 can be reduced with a simpler configuration in the same manner as when the shock absorber 9J is used.

  The developing mechanism and the image forming apparatus using the developing mechanism according to the present invention have been described above. However, various modifications can be easily made without changing the basic concept of the present invention, and such modifications are also possible. It is included in the scope of the present invention.

  For example, the shape of the shock absorber may be other than the shapes shown in the first to fifth embodiments of the present invention. For example, the shape may be a polygonal frustum shape or a combination of the first to fifth embodiments of the present invention.

  Further, the notch provided in the shock absorber may be not only a cross shape as shown in the first to fourth embodiments of the present invention but also a notch in, for example, six directions or eight directions. Further, the hole provided in the shock absorber may not be circular as shown in the first to fourth embodiments of the present invention, but may be, for example, a star or hexagon.

It is a figure which shows the structure of the 1st Example of the image development mechanism based on this invention. It is a graph which shows the noise reduction effect of the 1st Example of the image development mechanism concerning this invention. It is a figure which shows the structure of the 2nd Example of the image development mechanism based on this invention. It is a figure which shows the cross-sectional shape of the buffer of the developing mechanism which concerns on 2nd Example of this invention. It is a graph which shows the noise reduction effect of the buffer of the developing mechanism concerning the 2nd example of the present invention. It is a figure which shows the modification of the buffer of the developing mechanism which concerns on 2nd Example of this invention. It is a figure which shows the structure of the 3rd Example of the image development mechanism based on this invention. It is a figure which shows the cross-sectional shape of the buffer in the developing mechanism which concerns on the 3rd Example of this invention. It is a figure which shows the modification of the buffer in the developing mechanism which concerns on the 3rd Example of this invention. It is a figure which shows the structure of the modification of the buffer in the developing mechanism which concerns on the 3rd Example of this invention. It is a figure which shows the structure of the 4th Example of the image development mechanism based on this invention. It is a figure which shows the cross-sectional shape of the buffer in the developing mechanism which concerns on the 4th Example of this invention. It is a graph which shows the noise reduction effect of the shock absorber in the 4th example of the development mechanism concerning the present invention. It is a figure which shows the structure of the modification of the buffer in the developing mechanism which concerns on the 4th Example of this invention. It is a figure which shows the structure of the modification of the buffer in the developing mechanism which concerns on the 4th Example of this invention. 1 is a schematic configuration diagram of an image forming apparatus using a developing mechanism according to the present invention. It is a figure which shows the structure of the buffer in the developing mechanism which concerns on the 5th Example of this invention. It is a figure which shows the structure of the buffer in the developing mechanism which concerns on the 5th Example of this invention. It is a figure which shows the structure of the modification of the buffer in the developing mechanism which concerns on the 5th Example of this invention.

Explanation of symbols

1: image forming apparatus (color laser printer), 2: photosensitive belt, 3: intermediate transfer member,
4: charger, 5: exposure device, 61: cyan developer, 62: magenta developer,
63: yellow developer, 64: black developer, 65: spring,
66: cover, 66a: first wall surface portion, 66b: second wall surface portion,
67: Spring, 68: Collar cup-shaped member, 7: Cleaner, 8: Blade,
9A, 9B, 9C, 9D, 9E, 9F, 9G, 9H, 9I, 9J, 9K: buffer,
10: recording paper cassette, 12: registration roller, 13: transfer roller,
14: fixing device, 141: heating roller, 142: pressure roller, 16: recording paper,
17: paper discharge guide, 510: paper discharge tray, 20: paper feed device, 200: paper feed roller,
201: peeling pad, 30: frame

Claims (13)

  After the developer unit is brought into contact with the photoconductor to form a toner image on the photoconductor, the developer unit is moved in a direction to retract from the photoconductor, and the developer unit is collided with a wall surface and stopped at a predetermined position. An image forming apparatus having a mechanism for causing an image to be formed, wherein a shock absorber is provided at a location where the developing device collides with the wall surface, and energy transmitted to the wall surface due to the collision of the developing device is reduced by deformation of the shock absorber. Forming equipment.   A plurality of developing units; means for bringing the developing unit into contact with a photoconductor to form a toner image on the photoconductor; and thereafter moving the developing unit in a direction away from the photoconductor; A developing mechanism having a wall surface portion for stopping the developing device moving in a direction away from the body, wherein a shock absorber made of a viscoelastic material is formed on the surface of the wall surface portion.   The image forming apparatus according to claim 1, wherein the shock absorber is a viscoelastic body.   4. The developing mechanism or the image forming apparatus according to claim 2, wherein the shock absorber is made of a material having a logarithmic attenuation factor of 0.5 or more.   3. The developing mechanism or the image forming apparatus according to claim 1, wherein the shock absorber has a truncated cone shape having a hollow portion, and a cross-sectional shape thereof is an M-shaped member.   3. The developing mechanism or the image forming apparatus according to claim 1, wherein the shock absorber has a truncated cone shape having a hollow portion, and a cross-sectional shape thereof is a trapezoidal member.   3. The developing mechanism or the image forming apparatus according to claim 1, wherein the shock absorber is formed of a bowl-shaped member.   8. The developing mechanism or the image forming apparatus according to claim 1, wherein the shock absorber has a notch at a position where the developing device contacts.   8. The developing mechanism or the image forming apparatus according to claim 1, wherein the shock absorber has a hole portion smaller than the contact surface at the center of the contact surface with which the developing device contacts. .   A plurality of developing units; means for bringing the developing unit into contact with the photosensitive member when a toner image is formed on the photosensitive member; and then moving the developing unit in a direction away from the photosensitive member; and the photosensitive member A developing mechanism comprising: a first wall surface portion that stops the developing device moving in a direction away from the first wall surface portion; and a second wall surface portion that is disposed so as to have a predetermined distance from the first wall surface portion. A shock absorber comprising a shock-absorbing member slidably provided in a hole provided in the first wall surface portion and an elastic body disposed between the shock-absorbing member and the second wall surface portion is provided. Development mechanism characterized by.   The developing mechanism according to claim 10, wherein the buffer member is made of a viscoelastic body.   The developing mechanism according to claim 10, wherein the elastic body is a spring. An image forming apparatus comprising the developing mechanism according to claim 10.

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