JP2005338211A - Cleaning device, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device which effectively reduces noise caused between an image carrier and the cleaning device, and to provide a process cartridge including the cleaning device, and an image forming apparatus. <P>SOLUTION: The cleaning device 6 has a cleaning blade 25 for clearing away residual toner on the image carrier 1 in contact with the image carrier 1. The cleaning blade 25 comprises: a blade member 25a for performing cleaning by scraping toner on the image carrier 1 by the contact of the cleaning blade 25 with the image carrier 1; and a holder 20 for holding the blade member 25a. The resonance frequency of the image carrier 1 and that of the cleaning blade 25 are not matched with each other or are not present close to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a low-noise type cleaning device provided in an electrophotographic copying machine, FAX, printer, and the like, a process cartridge including the cleaning device, and an image forming apparatus.

  Conventional noise prevention has mainly been passive measures using sound absorbing and sound insulating materials, but the idea of active noise control (Active Noise Control) that intentionally emits reverse-phase sound and extinguishes it by interference has also been around for a long time. However, this active noise control has not been realized because an advanced control technique is required in actual application. In recent years, it has finally become possible to achieve this with the development of signal processing technology. Some of these famous active noise controls are those applied to refrigerators and automobiles, which cancel noise by causing them to interfere with noise by using speakers or other means to produce noise in the opposite phase. It is.

  Patent Document 1 describes an example in which an active noise control method is applied to an automobile or the like. Further, Patent Document 2 describes an example in which an active noise control method is applied to a copying machine. These make a sound having a phase opposite to that of a noise by a speaker or the like, interfere with the noise, and cancel the noise. Thus, in order to block leakage of noise generated by OA equipment and the like to the outside of the equipment, a silencer using a passive noise control method and a silencer using an active noise control method are effectively used. Further, in Patent Document 3, as a reduction in charging noise, a dynamic damper is provided on a photosensitive drum that is a vibrating body, thereby reducing drum vibration and resulting noise.

Patent No. 03097926 Japanese Patent Laid-Open No. 5-142887 JP-A-7-199731

  In a photoconductor unit of an image forming apparatus, stick slip occurs due to friction between the cleaning blade and the photoconductor, and vibration caused by the stick slip generates vibration noise from the photoconductor. There is a problem of generating noise by propagating from the unit to the unit housing. In order to remove the residual toner, a cleaning device is indispensable, and reduction of these noises is desired. This noise is often amplified by the resonance frequency of the photosensitive member (image carrier) and the resonance of the cleaning blade, and it is necessary to reduce these vibrations as much as possible.

  The present invention has been made paying attention to the above-mentioned circumstances, and an object of the present invention is to provide a cleaning device capable of effectively reducing noise generated between the image carrier and a process cartridge including the cleaning device, and An object is to provide an image forming apparatus.

  In order to solve the above problems, the invention described in claim 1 has a cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier, and the cleaning blade includes an image. In a cleaning device comprising a blade member for cleaning by scraping off toner on an image carrier by contact with the carrier, and a holder for holding the blade member, the resonance frequencies of the image carrier and the cleaning blade are mutually It is characterized by not being in agreement or in the vicinity.

  Further, the invention described in claim 2 has a cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier, and the cleaning blade is in contact with the image carrier. In the cleaning apparatus comprising a blade member for cleaning by scraping off the toner on the image carrier and a holder for holding the blade member, the holder has three or more points to be fixed, and its bending mode is generated. It is fixed at the position of the belly.

  Further, the invention described in claim 3 has a cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier, and the cleaning blade is in contact with the image carrier. In the cleaning device comprising a blade member that scrapes off the toner on the image bearing member for cleaning and a holder for holding the blade member, an elastic body is interposed between the holder and the member for fixing the holder. It is characterized by being inserted.

  According to a fourth aspect of the present invention, there is provided a cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier, the cleaning blade being in contact with the image carrier. In this cleaning apparatus, the holder is made of a non-metal having vibration damping properties.

  Further, the invention described in claim 5 has a cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier, and the cleaning blade is in contact with the image carrier. In a cleaning device comprising a blade member for cleaning by scraping off the toner on the image carrier and a holder for holding the blade member, noise generated by stick-slip between the image carrier and the cleaning blade The cleaning blade is provided with a vibration system having a resonance frequency similar to the frequency.

  The invention described in claim 6 is characterized in that in the invention described in claim 5, a plurality of vibration systems are provided.

  According to a seventh aspect of the present invention, there is provided an image forming apparatus comprising: an image carrier; and a cleaning unit for removing toner remaining on the image carrier. The cleaning apparatus according to any one of items 6 is provided.

  The process cartridge described in claim 8 comprises an image carrier, a charging unit, a developing unit, a transfer unit, and the cleaning device according to any one of claims 1 to 6. And is detachable from the main body of the image forming apparatus.

  According to a ninth aspect of the present invention, there is provided an image forming apparatus having at least two process cartridges according to the eighth aspect, wherein the developing means of each process cartridge develops different colors to form a color image. It is characterized by being.

  According to the present invention, it is possible to provide a cleaning device capable of effectively reducing noise generated between the carrier and a process cartridge and an image forming apparatus provided with the cleaning device.

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

  FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the invention. The image forming apparatus includes an image carrier 1 that rotates in the direction of arrow A, and a charging unit 2, an exposure unit 3, a developing unit 4, a transfer unit 5, a cleaning unit 6, and a charge eliminating unit 7 are disposed around the image carrier 1. Further, a fixing device (not shown) for fixing the toner image on the transfer material 8 transferred from the image carrier 1 is arranged.

  The charging unit 2 is disposed on the surface of the image carrier 1 at a predetermined distance in contact or non-contact with the image carrier 1, and applying a bias to the charging unit 2 causes the image carrier 1 to have a predetermined polarity and a predetermined potential. Is charged.

  The exposure means 3 uses an LD or LED as a light emitting element, and irradiates the image carrier 1 with light based on image data to form an electrostatic latent image.

  The developing means 4 includes a magnet roller fixed inside and a rotatable developer carrier, and holds the developer on the developer carrier. In this embodiment, two-component magnetic brush development using a two-component developer composed of toner and carrier is used as the developer. As another developing method, a one-component developing method that does not use a carrier may be used. A voltage is applied to the developer carrying member from a developing bias power source. Due to the potential difference between the developing bias and the potential of the electrostatic latent image formed on the surface of the image carrier 1, development is performed by attaching a charged toner to the electrostatic latent image in the developing region.

  The transfer unit 5 contacts the surface of the image carrier 1 with a predetermined pressing force at the time of transfer, and a voltage is applied to the surface of the image carrier 1 at the transfer nip portion between the image carrier 1 and the transfer unit 5. The toner image is transferred to the transfer material 8. In this embodiment, transfer is performed using a transfer roller. Transfer means such as corotron and transfer belt may be used.

  The neutralization unit 7 neutralizes the residual charge of the image carrier 1 from which the residual toner has been removed by the cleaning device, and is a light neutralization method using an LED or the like.

  The cleaning device 6 shown in FIG. 1 includes a vibrating member and a blade member, and removes residual toner from the image carrier 1 by pressing the blade member against the image carrier 1.

  The toner cleaned from the image carrier 1 by the cleaning device 6 is stored in a waste toner bottle (not shown) as waste toner by a toner conveying member and collected by a service person or the like, or is transported to a developing device as recycled toner and developed. Used for.

  FIG. 2 shows a graph of vibration transmissibility. As shown in the figure, when the excitation frequency / resonance frequency becomes 1, that is, when the resonance frequency and the excitation frequency coincide with each other, the vibration amplification factor becomes maximum and the vibration becomes large. In addition, in the range where the excitation frequency / resonance frequency is larger than √2, the amplification factor of vibration becomes smaller than 1, indicating that the vibration is reduced. The same applies to stick-slip during cleaning. When the cleaning blade 25 resonates due to stick-slip, the excitation force applied from the cleaning blade 25 to the photosensitive drum as an image carrier increases. Further, when the resonance frequency of the cleaning blade 25 and the resonance frequency of the image carrier coincide or are close to each other, the excitation force increased by the cleaning blade 25 is further amplified by the image carrier, resulting in a large vibration. To do. When the image bearing member is a photosensitive drum due to this vibration, the photosensitive member becomes an acoustic radiation surface and generates noise. Therefore, it is possible to obtain a cleaning device that does not generate noise because the resonance frequencies of the image carrier and the cleaning blade 25 do not coincide or exist in the vicinity. Further, not only the cleaning failure caused by the toner slipping due to the vibration is reduced, but also the effect of reducing the aging of the edge of the blade member 25a constituting the cleaning blade is effective.

  FIG. 3 shows an example of a vibration mode of the cleaning blade 25 when the holder 20 is fixed at two locations A and B. As shown in the figure, when a low-order bending mode occurs, the cleaning blade vibrates greatly at the portion where the antinode 22 of the mode resonates, resulting in a large cleaning failure and large excitation force. Therefore, as shown in FIG. 4, the resonance mode can be prevented from being generated by restraining by the fixing member 30 such as a screw at the portion that becomes the antinode 22 of the vibration, and the vibration of the cleaning blade 25 is reduced. It leads to noise reduction.

  FIG. 5 shows a schematic view of a cleaning device characterized in that an elastic body 35 is interposed between the holder 20 and a member 29 for fixing the holder 20. As shown in the figure, the stick-slip vibration generated by the blade member 25 through the elastic body 35 (a phenomenon that repeats being caught or slipped halfway when the object is slid) is vibrated by the elastic body 35 and dissipated as heat energy. The noise due to the vibration of the holder 20 is reduced. Further, the elastic body 35 is not limited, but a material having high vibration damping properties such as rubber or foam is preferable.

  In this embodiment, the cleaning blade 25 for cleaning the toner remaining in contact with the image carrier 1 holds the blade member 25 a and the blade member 25 a that perform cleaning by contacting the image carrier 1. Therefore, the holder 20 is made of a non-metal having a high damping property. Thereby, since the attenuation of the holder 20 itself is large and the vibration amplification factor is lower than that of a general metal, the excitation force when noise is generated is reduced, and noise is also reduced.

  FIG. 6 is a schematic diagram in which a vibration system 40 having a resonance frequency similar to the frequency of noise generated by stick-slip between the image carrier 1 and the cleaning blade is provided on the cleaning blade 25. As shown in the figure, the vibration system 40 is composed of a mass m and a spring constant k, and the natural frequency f of the vibration system is calculated by the following equation.

  By making this frequency coincide with the frequency of noise, energy is dissipated by the vibration system 40, and vibration transmission to the photosensitive member as the image carrier 1 serving as a vibrating body is reduced, resulting in noise reduction. Leads to.

  In the cleaning device, when there are a plurality of blade squeaking noise frequencies due to stick-slip, it is necessary to reduce the noise for each frequency. Therefore, a vibration system can be designed for a plurality of noise frequencies, and the vibration energy can be dissipated by the plurality of vibration systems 40 (see FIG. 7) to reduce noise.

FIG. 8 is a schematic sectional view of a process cartridge C including the cleaning device of the present invention. In the present invention, a plurality of components such as the image carrier 1, the charging unit 2, and the developing unit 4 are integrally coupled as a process cartridge C. The image forming apparatus main body such as a copying machine or a printer is detachable.
By providing the cleaning device in the detachable process cartridge C, it becomes possible to improve maintenance and to easily replace the cleaning device with another device.

  Next, an embodiment adapted to a color image forming apparatus using the process cartridge C including the cleaning device will be described.

  FIG. 9 shows a color image forming apparatus in which the above-described process cartridge C is juxtaposed along a transfer belt 50 extending horizontally. Four process cartridges C are arranged for each color of yellow, magenta, cyan, and black. The developing toner on the image carrier 1 developed in each process cartridge C is sequentially transferred onto a transfer belt 50 to which a horizontally extending transfer voltage is applied. In this way, images of yellow, magenta, cyan, and black are formed, multiple transferred onto the transfer belt, and transferred onto the transfer material 52 collectively. The multiple toner images on the transfer material 52 are fixed by a fixing device (not shown). The process cartridge C has been described in the order of yellow, magenta, cyan, and black. However, the process cartridge C is not specified in this order, and may be arranged in any order.

  Usually, since a color image forming apparatus has a plurality of image forming units, the apparatus becomes large. In addition, when each unit such as cleaning and charging fails individually or it is time to replace it due to its life, the device is complicated and it takes a lot of time to replace the unit. Therefore, as in this embodiment, a small and highly durable color image that can be replaced by the user by combining the components of the image carrier, the charging unit, and the developing unit integrally as a process cartridge. A forming apparatus can be provided.

  As described above, in this embodiment, since the resonance frequencies of the image carrier 1 and the cleaning blade 25 do not coincide with each other or do not exist in the vicinity, the vibration of the cleaning blade 25 in which stick slip becomes a vibration source causes the image carrier 1 to vibrate. The vibration is not amplified by the resonance, and the acoustic radiation is also reduced accordingly, so that the noise can be reduced.

  In the present embodiment, the number of points for fixing the holder 20 is three or more, so that the cleaning blade 25 itself is constrained at multiple points, thereby reducing the amount of vibration amplitude and reducing noise caused by stick-slip. . Further, since the number of restraint points increases, the number of bending vibration modes decreases in the blade longitudinal direction, and it becomes easy to prevent resonance frequency coincidence with the image carrier.

  In the present embodiment, the elastic body 35 is interposed between the holder 20 and the member 29 for fixing the holder 20, so that vibration due to stick-slip is reduced by the damping effect of the elastic body 35, and noise reduction is achieved. It becomes possible.

  Further, in the present embodiment, since the holder 20 is made of a non-metal having a high damping property, the vibration amplification by the cleaning blade 25 itself is less than that of the metal, so that the noise can be reduced.

  Further, in the present embodiment, since the cleaning blade 25 is provided with a vibration system 40 having a resonance frequency similar to the frequency of noise generated by stick-slip between the image carrier 1 and the cleaning blade 25, this vibration is provided. The system 40 acts as a dynamic vibration absorber. Instead of the vibration of the cleaning blade 25, the vibration system 40 dissipates energy, so that the vibration of the cleaning blade 25 and the image carrier 1 is reduced, and noise can be reduced. It becomes.

  In this embodiment, since the vibration system 40 dissipates energy for a plurality of frequencies by having a plurality of vibration systems 40, the vibrations of the cleaning blade 25 and the image carrier 1 are reduced, and the noise is reduced. It becomes possible. In the present embodiment, an image forming apparatus capable of reducing stick-slip noise in the cleaning device can be realized.

  Further, in the present embodiment, not only the noise due to cleaning is reduced, but the process cartridge C can be used to improve maintainability at the time of replacement.

  In addition, in the present embodiment, a color image forming apparatus that can reduce noise due to cleaning and improve maintainability when replacing a process cartridge is possible.

1 is a schematic view of a main part of an image forming apparatus provided with a cleaning device according to an embodiment of the present invention. It is a graph of a vibration transmissibility. It is a figure which shows an example of the vibration mode of the cleaning blade at the time of fixing a holder in two places. It is a top view which shows the state which prevented generation | occurrence | production of the resonance mode by restraining a holder in the part used as the antinode of a vibration. It is sectional drawing which shows the state which inserted the elastic body between the member for fixing a holder and a holder. It is the schematic of the cleaning apparatus provided with the vibration system. It is the schematic of the cleaning apparatus provided with the several vibration system. It is the schematic of the process cartridge provided with the cleaning apparatus which concerns on one Embodiment of this invention. FIG. 9 is a schematic view of a main part of a color image forming apparatus including a plurality of process cartridges of FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image carrier 6 Cleaning device 20 Holder 25 Cleaning blade 25a Blade member 40 Vibration system

Claims (9)

A cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier is provided, and the cleaning blade scrapes off the toner on the image carrier for cleaning by contacting the image carrier. In a cleaning device comprising a blade member for performing the above and a holder for holding the blade member,
A cleaning apparatus, wherein the resonance frequencies of the image carrier and the cleaning blade do not coincide with each other or do not exist in the vicinity. A cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier is provided, and the cleaning blade scrapes off the toner on the image carrier for cleaning by contacting the image carrier. In a cleaning device comprising a blade member for performing the above and a holder for holding the blade member,
The cleaning device is characterized in that the holder has three or more points to be fixed and is fixed at the position of the antinode of the generated bending mode. A cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier is provided, and the cleaning blade scrapes off the toner on the image carrier for cleaning by contacting the image carrier. In a cleaning device comprising a blade member for performing the above and a holder for holding the blade member,
A cleaning device, wherein an elastic body is interposed between a holder and a member for fixing the holder. A cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier is provided, and the cleaning blade scrapes off the toner on the image carrier for cleaning by contacting the image carrier. In a cleaning device comprising a blade member for performing the above and a holder for holding the blade member,
A cleaning device, wherein the holder is a non-metal having vibration damping properties. A cleaning blade for cleaning the toner remaining on the image carrier in contact with the image carrier is provided, and the cleaning blade scrapes off the toner on the image carrier for cleaning by contacting the image carrier. In a cleaning device comprising a blade member for performing the above and a holder for holding the blade member,
A cleaning device, wherein a vibration system having a resonance frequency similar to a frequency of noise generated by stick-slip between an image carrier and a cleaning blade is provided on the cleaning blade.   The cleaning apparatus according to claim 5, comprising a plurality of vibration systems.   7. The cleaning apparatus according to claim 1, wherein the image forming apparatus includes an image carrier and a cleaning unit for removing toner remaining on the image carrier. An image forming apparatus comprising:   An image carrier, a charging unit, a developing unit, a transfer unit, and the cleaning device according to any one of claims 1 to 6 are integrally provided and detachable from the main body of the image forming apparatus. Process cartridge.   9. An image forming apparatus comprising: at least two process cartridges according to claim 8, wherein the developing means of each process cartridge performs development of different colors to form a color image.

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