JP2014102431A - Process cartridge and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent accumulation of ozone inside a charging device, and reduce the size, weight, and cost of an image forming apparatus.SOLUTION: A process cartridge includes a photoreceptor, a charging device that charges the photoreceptor, and a developing device that develops an electrostatic latent image on the photoreceptor. The process cartridge includes an accommodation cover that accommodates at least a driving mechanism including a driving shaft of the developing device; and the charging device includes a first air-flow channel extending in an axial direction of the photoreceptor. The accommodation cover is provided with a first air suction port for sucking an air from the outside of the process cartridge, and a first air exhaust port that is communicated with the first air-flow channel to exhaust the air.

Description

The present invention relates to a process cartridge used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an image forming apparatus including the process cartridge.

A charging device used in an electrophotographic image forming apparatus is accompanied by ozone generation during charging depending on the charging method. Since ozone is a harmful substance, it is not preferable to discharge it outside the apparatus, and it is necessary to remove it with an ozone removing filter or the like. In addition, ozone has an action of promoting deterioration of the photoreceptor, and if ozone stays in the vicinity of the photoreceptor, image quality is deteriorated. Thus, a method is already known in which an air flow path is provided in a charging device constituting a process cartridge, and an air flow is formed through the charging device so as to be guided to an ozone removal filter.

Further, when the developing device constituting the process cartridge is configured to circulate in two axes by a stirring screw and a supply screw, a driving mechanism (gear train) for transmitting the biaxial drive is provided in front of the process cartridge and the image forming apparatus. There is something to have. In this configuration, it may be necessary to arrange a cover for housing the drive mechanism in order to improve the appearance and reduce noise caused by the drive mechanism.

The storage box for storing the drive unit is easy to attach to and remove from the development device as a storage box with a box shape that partitions a part of a container integrally formed with the development device or a structure that covers the drive unit of the development device. There is a configuration.

In Patent Document 1 (Japanese Patent Laid-Open No. 2012-3058), for the purpose of efficiently cooling the developing device, air is supplied to a storage box that houses a stirring member of the developing device and a drive unit that rotationally drives the developing member. A configuration for discharging is disclosed.
The drive unit includes a stirring gear for rotating the developer stirring member in the developer container and a developing gear for rotating the developing member for supplying the developer to the surface of the image carrier, and the storage box is a rotating shaft of both members. Support. There is disclosed a configuration in which an intake port for taking in air from the outside of the developing device and an exhaust port for taking in the air are provided in a storage box that stores the drive unit.

However, it is possible to eliminate the problem that ozone stays in the charging device because the air flow passage is not formed in the charging device only by circulating air through the storage box of the driving unit of the developing device. Not.

The developing device is a device that develops and visualizes the electrostatic latent image formed on the latent image carrier using a two-component developer composed of toner and carrier. The developer whose toner has been consumed after completion of the development process in the development area is collected, mixed with the replenished toner, stirred, and again developed.

In order to obtain a stable toner image, the developer used in the developing device having such a configuration needs to maintain a constant toner concentration and charge amount. The toner density is adjusted by the amount of toner consumed during development and the amount of replenished toner, and the charge amount is given by frictional charging during mixing of the carrier and toner.

In recent image forming apparatuses, miniaturization, weight reduction, and cost reduction are required.
However, in a process cartridge used in a conventional image forming apparatus, if the air flow path of the developing device or the charging device and the air inlet and outlet of the cover that houses the drive mechanism are formed as separate parts, The number of parts tends to increase. For this reason, there existed a problem that an apparatus will enlarge, the weight of an apparatus will increase, and an apparatus will become high-cost.
In addition, since the structure is such that only the drive mechanism is cooled and air does not pass through the charging device, ozone stays in the charging device, and the surface of the photoreceptor is contaminated by the remaining ozone, or ozone accumulates in the charging device. Subsequently, there has been a problem of adversely affecting the environment around the image forming apparatus.

The present invention has been made in view of the above problems, and is provided with an air suction port and a discharge port provided in a cover that accommodates the drive mechanism, and the discharge port communicates with the air flow passage of the charging device. The purpose is to prevent ozone retention in the device. Another object of the present invention is to reduce the size, weight, and cost of the process car, ridge, and image forming apparatus.

In order to achieve the above object, the present invention employs the following solutions. A first solving means of the present invention is a process cartridge having a photosensitive member, a charging device for charging the photosensitive member, and a developing device for developing an electrostatic latent image on the photosensitive member, wherein the process cartridge is at least A process cartridge having a drive shaft and a drive mechanism of the developing device and a cover for housing the drive mechanism, and the charging device having a first air flow path in the axial direction of the photosensitive member. A first suction port for sucking air from the outside, and a first discharge port for discharging air from the process cartridge in communication with the first air flow passage. is there.

As described above, according to the present invention, the cover that houses the drive mechanism for conveying the developer of the developing device includes the air suction port from the outside of the developing device and the discharge port that discharges air in the direction opposite to the air suction port. Provided, and the discharge port communicates with the air flow path of the charging device. For this reason, there is an excellent effect that ozone retention in the charging device can be prevented and the process cartridge and the image forming apparatus can be reduced in size, weight, and cost.

The air flow passage of the charging device can exhaust the ozone generated in the charging device efficiently by a dedicated air flow passage provided in the charging device. A cover may be disposed so as to cover the charging roller of the charging device. As described above, it is possible to prevent or reduce the influence of the air flow on the devices in the vicinity of the charging device at the time of discharging the air, and the configuration in which the dedicated air flow passage is attached to the charging device or the vicinity of the charging device.

Further, the air flow path may be a gap portion that is a gap with the charging device in the axial direction of the photosensitive member, or may be a gap portion along the partition wall when a partition wall is disposed in the vicinity of the charging device. Good.

It is possible to employ a mechanism for generating an air flow from the end portion on the housing cover side that houses the drive mechanism of the developing device of the process cartridge toward the opposite end portion of the process cartridge. As a result, retention of air containing ozone gas in the process cartridge and the image forming apparatus can be prevented and the number of parts can be reduced, and the process cartridge and the image forming apparatus can be reduced in size, weight, and cost. .

In addition, it is possible to effectively cool the drive mechanism of the developing device.

1 is a schematic configuration diagram illustrating a printer according to an embodiment of an image forming apparatus to which the present invention is applied. 1 is a cross-sectional view illustrating a schematic configuration illustrating an example of a process cartridge of a printer according to an embodiment of the present invention. FIG. 3 is a schematic perspective view illustrating an example of a process cartridge of the printer according to the embodiment of the invention. FIG. 4 is a perspective view in which a housing cover for housing the drive unit is attached to the drive unit of the process cartridge of the printer according to the embodiment of the present invention. It is the schematic of the accommodation cover which accommodates the drive part in embodiment of this invention. It is the schematic which shows the back surface side of the accommodation cover in embodiment of this invention. It is a figure explaining the distribution | circulation of the air in the process cartridge and the accommodation cover in embodiment of this invention. It is a figure explaining circulation of the air in a process cartridge and an accommodation cover in another embodiment of the present invention. It is a figure explaining circulation of the air in a process cartridge and a storage cover in another embodiment of the present invention.

Embodiments of the present invention will be described below. The present invention has the following characteristics in a process cartridge used in an image forming apparatus. The present invention is characterized in that an air suction port and a discharge port are provided in a cover that houses the drive mechanism, and the discharge port communicates with the air flow path of the charging device.

FIG. 1 is a schematic configuration diagram illustrating the overall configuration of the image forming apparatus according to the present embodiment.
In many electrophotographic image forming apparatuses, four process cartridges (6Y, 6M, 6C, 6K) corresponding to each color (yellow: Y, magenta: M, cyan: C, black: K) are arranged in parallel. ing. Many process cartridges are composed of a plurality of devices including a developing device and a charging device. In FIG. 1, the printer 100 includes four toner image forming units 6Y, 6M, 6C, and 6K for forming toner images of respective colors of yellow: Y, magenta: M, cyan: C, and black: K. Yes.

The toner image forming units 6Y, 6M, 6C, and 6K constitute process cartridges 6Y, 6M, 6C, and 6K that are detachably attached to the main body of the printer 100.

  The process cartridges 6Y, 6M, 6C, and 6K use toners of Y, M, C, and K, which are different colors, as image forming materials, respectively, but have the same configuration.

Taking a process cartridge 6Y for forming a Y toner image as an example, it includes a drum-shaped photosensitive member 1Y as an image carrier, a drum cleaning device 2Y, a charge eliminating device (not shown), a charging device 4Y, a developing device 5Y, and the like. These are integrated.

The process cartridge 6Y is detachable from the main body of the printer 100, and can be replaced as a consumable part at a time.

The charging device 4Y uniformly charges the surface of the photoreceptor 1Y that is rotated clockwise in the drawing by a driving unit (not shown).

The uniformly charged surface of the photoconductor 1Y is exposed and scanned with a laser beam L based on Y image information from an optical writing unit 7 as an exposure device to form an electrostatic latent image for Y. The

The electrostatic latent image for Y is developed into a Y toner image by the developing device 5Y using a two-component developer composed of nonmagnetic Y toner and a magnetic carrier.

A primary transfer bias roller 9Y serving as a transfer unit is applied with a transfer bias from a high voltage power source to form a transfer electric field with the photoreceptor 1Y. By this transfer electric field, the Y toner image on the photoreceptor 1Y is transferred onto the intermediate transfer belt 8 at an intermediate transfer position between the photoreceptor 1Y and the intermediate transfer belt 8.

The drum cleaning device 2Y removes toner remaining on the surface of the photoreceptor 1Y after the intermediate transfer position. A static elimination device (not shown) neutralizes residual charges on the photoreceptor 1Y after cleaning, and the surface of the photoreceptor 1Y is initialized by this static elimination to prepare for the next image formation.

The developing device 5Y agitates and conveys the two-component developer 53Y composed of the nonmagnetic toner and the magnetic carrier in the developing container 54Y by the agitating and conveying member 55Y (configuration that circulates on two axes of the agitating screw and the supply screw). A magnetic brush is formed by magnetic poles contained in a developer carrier 51Y as a developer carrier.

The agitating / conveying member 55Y and the developer carrying member 51Y are rotated by a rotation driving device (not shown), and when the process linear speed of the printer is switched, the rotation driving device causes the stirring / conveying member 55Y and the developer carrying member 51Y to line up. Speed can be switched.

The developer 53Y on the developer carrier 51Y is transported to the development area as the developer carrier 51Y rotates.

As the developer 53Y is conveyed to the development area, a large number of magnetic carriers in the developer 53Y gather with the toner along the magnetic field lines of the development pole in the developer carrier 51Y, and a magnetic brush (developer of developer) Form a head).

The thickness of the developer 53Y on the developer carrier 51Y is regulated by the developer regulating member 52Y.

A developing bias is applied to the developer carrier 51Y from a high voltage power source at a position facing the photoreceptor 1Y as a latent image carrier, and the electrostatic latent image on the photoreceptor 1Y is contained in the developer on the developer carrier 51Y. The toner adheres and is developed.

Toner is replenished from the toner replenishing device 32Y into the developing container 54Y of the developing device 5Y, and this toner replenishing device 32Y is driven by the drive motor 41Y to replenish toner into the developing container 54Y.

The developing devices of the other process cartridges 6M, 6C, 6K (hereinafter referred to as 5M, 5C, 5K) have the same configuration as the developing device 5Y of the process cartridge 6Y.

A two-component developer composed of a non-magnetic toner of M, C, and K in each developer container and a magnetic carrier is agitated and conveyed by an agitating and conveying member, and a magnetic brush is formed by magnetic poles contained in the developer carrier. To do.

The agitating / conveying member and the developer carrying member 51Y are rotated by a rotation driving device (not shown), and when the process linear speed of the printer is switched, the rotation driving device causes the stirring / conveying member and the developer carrying member 51Y to line. Speed can be switched.

The developer on the developer carrier 51Y is conveyed to the development area as the developer carrier 51Y rotates.

As the developer is transported to the development area, a large number of magnetic carriers in the developer gather together with the toner along the magnetic field lines of the development pole in the developer carrier 51Y to form a magnetic brush. The thickness of the developer on the developer carrier 51Y is regulated by the developer regulating member 52Y.

A developing bias is applied to each developer carrier from a high-voltage power source at a position facing the photoreceptors 1M, 1C, and 1K as latent image carriers, and the electrostatic latent images on the photoreceptors 1M, 1C, and 1K are respectively The toner in the developer on each developer carrier is attached and developed.

The developing containers 5M, 5C, and 5K are respectively replenished with toner of M, C, and K colors from toner replenishing devices 32M, 32C, and 32K (see FIG. 1).

These toner replenishing devices 32M, 32C, and 32K are respectively driven by drive motors (hereinafter referred to as 41M, 41C, and 41K) to replenish toner into the developing containers of the developing devices 5M, 5C, and 5K.

As shown in FIG. 1, in the other process cartridges 6M, 6C, and 6K, similarly to the process cartridge 6Y, photoconductors 1M, 1C, and 1K as image carriers, a drum cleaning device, a discharging device, and charging devices 4M and 4C. 4K, developing devices 5M, 5C, 5K and the like.

In the same manner as the process cartridge 6Y, toner images of M, C, and K colors are formed on the photoreceptors 1M, 1C, and 1K.

The toner images of these colors are transferred onto the intermediate transfer belt 8 by the primary transfer bias rollers 9M, 9C, and 9K as transfer means so as to overlap with the Y toner image, thereby forming a full color image.

Below the process cartridges 6Y, 6M, 6C, and 6K in the drawing, an optical writing unit 7 is disposed as an exposure device as a latent image forming unit.

The optical writing unit 7 serving as an exposure apparatus emits each laser beam L emitted from a plurality of light sources based on image information of each color of Y, M, C, and K to each of the process cartridges 6Y, 6M, 6C, and 6K. The bodies 1Y, 1M, 1C and 1K are respectively irradiated and exposed.

By this exposure, electrostatic latent images for Y, M, C, and K are formed on the photoreceptors 1Y, 1M, 1C, and 1K.

The optical writing unit 7 as an exposure apparatus scans the laser light L emitted from the light source with a polygon mirror that is rotationally driven by a motor, and passes the photosensitive members 1Y, 1M, and Irradiate 1C, 1K.

On the lower side of the optical writing unit 7 as an exposure apparatus in the drawing, a paper feed unit having a paper feed cassette 26 and a paper feed roller 27 incorporated therein is disposed.

The paper feed cassette 26 stores a plurality of transfer papers P as recording bodies, and a paper feed roller 27 is in contact with each uppermost transfer paper P.

When the paper feed roller 27 is rotated counterclockwise in the figure by a driving means (not shown), the uppermost transfer paper P of the paper feed cassette 26 is fed by the paper feed roller 27 and between the rollers of the registration roller pair 28. It is sent toward.

The registration roller pair 28 rotates to pinch the transfer paper P, but temporarily stops rotating immediately after the transfer paper P is pinched. Then, the registration roller pair 28 sends the transfer paper P toward a secondary transfer nip described later at an appropriate timing.

Above the process cartridges 6Y, 6M, 6C, and 6K, there is an intermediate transfer unit 15 that moves an endless intermediate transfer belt 8 as an intermediate transfer member serving as an image carrier while being stretched by a plurality of rollers. It is arranged.

The intermediate transfer unit 15 includes an intermediate transfer belt 8, four primary transfer bias rollers 9Y, 9M, 9C, and 9K, a cleaning device 10, a secondary transfer backup roller 12, a cleaning backup roller 13, a tension roller 14, and the like. I have.

The intermediate transfer belt 8 is stretched around the secondary transfer backup roller 12, the cleaning backup roller 13, and the tension roller 14, and at least one of the rollers is driven to rotate by the rotation driving unit, thereby rotating counterclockwise in the figure. It can be moved.

The primary transfer bias rollers 9Y, 9M, 9C, and 9K sandwich the intermediate transfer belt 8 that is moved in this manner between the photoreceptors 1Y, 1M, 1C, and 1K to form primary transfer nips. .

The primary transfer bias rollers 9Y, 9M, 9C, and 9K are applied with a transfer bias having a polarity opposite to that of the toner (for example, plus) from the high-voltage power source on the back surface (loop inner peripheral surface) of the intermediate transfer belt 8.

All of the rollers 12 to 14 except the primary transfer bias rollers 9Y, 9M, 9C, and 9K are electrically grounded.

The intermediate transfer belt 8 sequentially passes through the primary transfer nips for Y, M, C, and K as it moves, and Y, M, and C on the photoreceptors 1Y, 1M, 1C, and 1K. , K toner images of the respective colors are superimposed and primarily transferred.

As a result, a four-color superimposed toner image (four-color toner image: full-color image) is formed on the intermediate transfer belt 8.

The secondary transfer backup roller 12 forms a secondary transfer nip with the intermediate transfer belt 8 sandwiched between the secondary transfer roller 19 as a transfer means, and the secondary transfer roller 19 is applied with a transfer bias from a high voltage power source. The

The four-color superimposed toner image formed on the intermediate transfer belt 8 is transferred onto the transfer paper P from the resist roller pair 28 by the secondary transfer roller 19 at the secondary transfer nip.

Untransferred toner that has not been transferred onto the transfer paper P adheres to the intermediate transfer belt 8 after passing through the secondary transfer nip. This is cleaned by the cleaning device 10.

In the secondary transfer nip, the transfer paper P is sandwiched between the intermediate transfer belt 8 whose surface moves in the forward direction and the secondary transfer roller 19 and is conveyed in the direction opposite to the registration roller pair 28 side. Is done.

When the transfer paper P sent out from the secondary transfer nip passes through the fixing device 20, the four-color superimposed toner image transferred to the surface is fixed by heat and pressure. Thereafter, the transfer paper P is discharged out of the apparatus through a pair of paper discharge rollers 29.

A stack unit 30 is formed on the upper surface of the main body of the printer 100, and the transfer paper P discharged to the outside by the paper discharge roller pair 29 is sequentially stacked on the stack unit 30.

Above the secondary transfer backup roller 12, a reflection type photosensor 40 as an image density detection means is disposed, and this reflection type photosensor 40 outputs a signal corresponding to the light reflectance on the intermediate transfer belt 8. To do.

In this reflection type photosensor 40, the difference between the amount of reflected light on the surface of the intermediate transfer belt 8 and the amount of reflected light of a reference pattern image to be described later can be set to a sufficient value between the diffused light detection type and the regular reflection light detection type. Is used.

The reflection type photosensor 40 can be disposed close to each of the photoreceptors 1Y, 1M, 1C, and 1K to serve as image density detection means on the photoreceptor surface.

A toner concentration sensor 56Y for detecting the toner concentration in the developing device 5Y is mounted on the developing container 54Y. As the toner concentration sensor 56Y, for example, a magnetic permeability sensor including an oscillator, a resonance circuit, a phase comparison circuit, an integration circuit, and an impedance conversion circuit is used.

The developer 53 (53Y, 53M, 53M, 53M, 53C, 53K) changes the resonance frequency of the resonance circuit due to the magnetic permeability (toner concentration) of the developer 53 (53Y, 53M, 53C, 53K) in the developing device 5 and changes the output of the resonance circuit. , 53C, 53K) is detected.

The control unit 150 controls the toner image forming units 6Y, 6M, 6C, and 6K, the optical writing unit 7 as an exposure device, the paper feeding cassette 26, the rotation driving unit of the registration roller pair 28, and the intermediate transfer unit 15.

Furthermore, the reflection type photosensor 40, the toner density sensor 56 (56Y, 56M, 56C, 56K) of each process cartridge 6Y, 6M, 6C, 6K, and the like are controlled.

The control unit 150 includes a CPU that controls the arithmetic unit and the like, and a RAM that stores data. Further, toner supply from each color toner supply device 32Y, 32M, 32C, 32K to the developing devices 5Y, 5M, 5C, and 5K during paper feeding is controlled.

The characteristics of the present invention described above in the image forming apparatus having the above configuration will be described in detail below. The image forming apparatus shown in FIG. 1 is an example showing a basic configuration and a basic arrangement. In addition to the configuration shown in FIG.

FIG. 2 is a diagram showing an embodiment showing the basic configuration and basic arrangement of the process cartridge of the present invention, and shows the configuration of the process cartridge 6Y of FIG. A plurality of devices including a developing device 5Y, a developer carrier 51Y, a developer regulating member 52Y, a photoreceptor 1Y, a cleaning device 2Y, and a charging device 4Y are provided. The arrangement of each component of each component in the process cartridge 6Y shown in FIG. 2 shows an example of arrangement at an appropriate position.

As shown in FIG. 2, the process cartridge 6Y of the present invention uses an air gap (first air flow path) in the axial direction of the photoreceptor 1Y using a gap around the photoreceptor 1Y and the charging device 4Y. ). An air flow passage 81Y using the above-mentioned gap portion communicating with the photoreceptor 1Y in the axial direction of the charging device 4Y or an air flow passage 80Y having a dedicated exhaust duct so as to cover the charging portion of the charging device 4Y, for example. Deploy. By flowing the air sucked from the side of the housing cover 60 (shown in FIG. 4) in the axial direction of the charging device 4Y, the air containing the ozone gas generated by the charging operation of the charging device 4Y is pushed out of the charging device 4Y. It becomes possible to exhaust.

In FIG. 2, an air flow passage (second air flow passage) is formed in the peripheral portion of the developing container 54Y of the developing device 5Y, and ozone gas that may stay in the peripheral portion of the developing device 5Y is formed. The contained air can be pushed out of the developing device 5Y or exhausted. Air flow passages 82Y and 83Y communicating in the axial direction of the developing device 5Y are formed using the gap around the developing device 5Y. For example, by arranging the air flow passage 83Y using a gap or the air flow passage 82Y as a dedicated exhaust duct, the air sucked from the housing cover 60 side can be circulated in the axial direction of the developing device 5Y. become. It becomes possible to push out or exhaust the air containing ozone gas generated by the charging operation of the charging device 4Y and staying around the developing container 54Y of the developing device 5Y to the outside of the developing device 5Y. Further, the developing container 54Y of the developing device 5Y can be cooled by air flow.

FIG. 3 is a perspective view showing one embodiment of the process cartridge of the present invention. In addition, the process cartridge 6 (hereinafter collectively referred to as 6Y, 6M, 6C, and 6K) includes a developing device 5 (hereinafter collectively referred to as 5Y, 5M, 5C, and 5M) and a charging device 4 (hereinafter referred to as 4Y, 4M, 4C, and 4M). And a plurality of devices including the general name. The reference numerals in FIG. 3 are represented by generic names in which the alphabetical symbols of the respective constituent elements in the process cartridges 6Y, 6M, 6C, and 6K are deleted. Hereinafter, the same notation is used.

In the process cartridge 6 shown in FIG. 3, the developing device 5 has two shafts of a stirring / conveying member 55 (hereinafter collectively referred to as 55Y, 55M, 55C, 55M. The developer is circulated. The gear train of the drive mechanism 64 that transmits the drive of the two shafts is provided on one end side of the process cartridge 6.

Depending on the charging method, the charging device 4 is accompanied by ozone generation during charging. The charging device 4 normally applies a high voltage to a thin tungsten wire and charges the photoconductor 1 by corona discharge. At this time, ozone generated by the corona discharge contaminates the surface of the photoconductor.

Further, when discharging to the outside of the machine, it is necessary to reliably remove it with an ozone removal filter or the like. As described above, ozone has an action of promoting deterioration of the photosensitive member, and if ozone stays in the vicinity of the photosensitive member, it leads to deterioration of image quality.

Therefore, as shown in FIG. 2, in order to push out the air containing ozone from the charging device 4 to the outside of the charging device 4, the air intake passages 65 of the air flow passages 80 and 81 and the air flow passages 80 and 81 are inserted into the charging device 4. , And an air outlet 74 of the air flow passage 80 is provided. One or both of the air flow passage 80 and the air flow passage 81 may be provided. The air flow passage 81 uses a gap between the charging device 4 and the photosensitive member 1, and the outlet of the air flow passage 81 uses a gap between the charging device 4 and the photosensitive member 1. These air flow passages allow the air containing ozone to be discharged outside without being retained in the process cartridge. The air flow passage 80 has an exhaust duct structure that covers the periphery of the charging device 4 so as to exclusively discharge air containing ozone in the process cartridge.

FIG. 4 is a diagram illustrating an example in which a housing cover 60 that houses the driving unit of the developing device 5 is installed on one end side of the process cartridge 6. Air for cooling the gear train of the drive mechanism 64 can be taken in from an air suction port (first air suction port) 67 provided in the housing cover 60. An air outlet 68 (first air outlet) provided in the housing cover 60 is disposed. The air inlet 67 and the air outlet 68 are in communication. Further, as will be described later, the air discharge port 68 can communicate with an air flow passage 80 and an air flow passage 81 provided in the charging device 4. Further, the storage cover 60 can also have an air suction port 70 (second air suction port) that communicates from an air flow inlet 69 provided in the developing device 5 to an air flow passage 82 and an air flow passage 83. The air suction port 70 has an air discharge port 71 (second air discharge port) that communicates therewith. Further, an air inlet 72 for sucking air from the lower side of the housing cover 60 may be provided.

As shown in FIG. 3, the state in which the gear train of the drive mechanism 64 of the developing device 5 is exposed is not preferable in appearance, and operation noise is generated when the drive mechanism 64 is driven. As shown in FIG. 4, the process cartridge 6 is provided with a housing cover 60 for housing the drive mechanism 64 from the viewpoint of improving the appearance and reducing the noise caused by the operation sound. The housing cover 60 is attached and fixed to the housing portion of the process cartridge 6 by a fixing screw or the like (not shown). The housing cover 60 can be easily removed by removing a fixing screw or the like.

FIG. 5 is a view showing an embodiment of the accommodation cover 60 in the present invention. The housing cover 60 has air suction ports 67 (communication with the air suction ports 65 of the charging device 4) and 70 (communication with the air suction ports 69 of the air flow passages 82 and 83 of the developing device 5). Is provided). The air suction port 67 is provided with an air discharge port 68 with a guide portion, and the air suction port 70 is provided with an air discharge port 71 with a guide portion. The housing cover 60 can have an air inlet 72 provided at the lower portion thereof. The housing cover 60 can be easily and inexpensively manufactured by a die casting method using a lightweight metal such as an aluminum alloy.

FIG. 6 is a perspective view of the housing cover 60 as viewed from the air outlet side of the housing cover 60. In this embodiment, air outlets 68 and 71 with guide portions are shown.

Examples of the present invention will be described below in detail with reference to FIGS. 7, 8 and 9 showing the air circulation state in the process cartridge 6. The arrows in the figure indicate the direction of air flow.

FIG. 7 is a view showing the air circulation state in the process cartridge 6. An air discharge port 75 is provided on the other end side of the process cartridge 6 to discharge air containing ozone from the air flow passage 80 and the air flow passage 81 (shown in FIG. 2) of the process cartridge 6. An air exhaust port 74 is provided in the air flow passage 80. An intake fan 85 disposed on the air suction side for taking in air from outside into the charging device 4 and an exhaust fan 86 disposed on the exhaust side for pushing out air containing ozone to the outside of the charging device 4 can be provided. . The intake fan 85 and the exhaust fan 86 can effectively perform intake and exhaust of air.
As shown in FIG. 7, in order to guide air to the air flow passage 80 in the charging device 4, the accommodation cover 60 is also provided with an air circulation space, an air suction port 67, and an air discharge port 68. The suction port 65 and the air discharge port 68 of the housing cover 60 are arranged to communicate with each other.

In FIG. 7, the housing cover 60 that houses the drive mechanism 64 is provided with an air suction port 70 in the lower part on the front surface side and an air discharge port 71 in the upper part on the back surface side, and the air taken in from the air suction port 70 is transferred to the housing mechanism 60. The gear train is cooled by passing through the gear train surface. Further, this air is circulated from the suction port 65 of the air flow passage 80 provided on one end side of the charging device 4, and from the discharge port 75 of the process cartridge via the air discharge port 74 on the other end side of the charging device 4. Indicates that air containing ozone is pushed out and discharged.

FIG. 8 is a view showing the air circulation state in the process cartridge 6. As shown in FIGS. 4 and 8, the air discharge port 68 of the housing cover 60 is provided with a guide portion 68a for improving the air flow in a rectified state. The front end of the guide portion 68a is close to and communicates with the air suction port 65 of the charging device 4. The structure in which the air discharge port 68 of the storage cover 60 and the air suction port 65 of the charging device 4 communicate with each other stabilizes the flow of air flowing to the air flow passage 80 of the charging device 4 and ensures that the air containing ozone is reliably supplied. Can be pushed out. In addition, by arranging the air suction port 65 in a communicating state in the vicinity of the suction port of the air flow passage 81 using the gap, the flow of the circulating air is stabilized, and the air containing ozone is surely removed from the apparatus. Can be extruded. Further, by providing the air suction port 72, the air taken in from the lower part of the housing cover can pass through the surface of the gear train of the drive mechanism 64, and the gear train can be cooled.

FIG. 9 is a view showing the air circulation state in the process car and the ridge 6. When the developing device 5 reaches a high temperature, the toner accommodated in the developing device 5 is fixed, and an abnormality may occur on the output image. Therefore, the developing device 5 needs to be cooled. In that case, the same air flow path can be disposed in the developing device 5 as in the charging device 4. The developing device 5 is provided with an air flow passage 82, an air flow passage 83 (shown in FIG. 2), an air suction port 69, and an air discharge port 77. Further, in order to guide air to the air flow passage 82 in the developing device 5, the housing cover 60 is also provided with a gap (not shown) for air circulation, an air suction port 70, and an air discharge port 71. The air suction port 69 of the developing device 5 and the air discharge port 71 of the housing cover 60 communicate with each other.

The drive mechanism 64 of the developing device 5 generates heat due to friction between the drive shaft and the bearing during rotation. This heat may cause the toner in the vicinity of the drive mechanism 64 to become hot and stick. In order to prevent this, it is effective to cool the drive mechanism 64 by applying air as shown in FIG. Air sucked from the air suction port 70 passes through the gear train surface of the drive shaft of the drive mechanism 64 by the air suction port 70 provided in the housing cover 60 and the air discharge port 68 to the charging device 4. Air circulates through the air inlet 65. With such an arrangement, the air sucked through the air suction port 70 and the air discharge port 71 of the housing cover 60 flows in a direction perpendicular to the drive shaft of the drive mechanism 64. Thereby, the air sucked into the housing cover 60 can be guided to the charging device 4 while being applied to the drive mechanism 64. Cooling of the drive mechanism 64 and air containing ozone in the charging device 4 can be discharged. In FIG. 9, the air taken in from the air suction port 70 flows through the housing cover 60 from the air discharge port 71 and also flows in the direction passing through the gear train surface of the drive mechanism 64 to cool the gear train. To do.

The process cartridge of the present invention has a configuration in which the charging device has a first air flow path in the axial direction of the photosensitive member, as well as a driving shaft and a driving mechanism of the developing device, and a cover for housing the driving mechanism. Further, in the process cartridge, the cover is provided with a first air suction port for sucking air from the outside of the developing device and a first discharge port for the sucked air communicating with the first air flow passage. It has the composition which is. This configuration is characterized in that the air containing ozone is discharged outside the apparatus, thereby suppressing deterioration of the photoreceptor due to the residence of ozone gas and suppressing occurrence of density unevenness in the image over time. .

The process cartridge of the present invention can be applied to the image forming apparatus shown in FIG.

An image forming apparatus according to the present invention includes a process cartridge including a latent image forming apparatus that forms a latent image on an image carrier and a developing unit that develops and visualizes the latent image on the image carrier. The image forming apparatus further includes a transfer unit that transfers an image on the image carrier to the recording member via an intermediate transfer member, and a fixing unit that fixes the image transferred to the recording member.

In this image forming apparatus, an electrophotographic printer as an image forming apparatus to which the process cartridge according to the present invention is applied can obtain a high-quality image without causing uneven density in the image over time.

In addition, a full color image can be formed by using a plurality of the developing devices of the present invention that contain developers of different colors, and a high quality color image can be obtained without causing density unevenness in the image over time. Is obtained.

100 Image forming apparatus
4Y, 4M, 4C, 5M Charger 5Y, 5M, 5C, 5M Developing device 6Y, 6M, 6C, 6M Process cartridge 60 Housing cover 64 Drive mechanism 80, 81, 82, 83 Air flow path 65 Air inlet port 68 Air exhaust Exit

JP 2012-3058 A

Claims (5)

A process cartridge having a photosensitive member, a charging device for charging the photosensitive member, and a developing device for developing an electrostatic latent image on the photosensitive member, wherein the process cartridge includes at least a driving shaft of the developing device. In the process cartridge in which the charging device has a first air flow path in the axial direction of the photoconductor, the first air that sucks air from the outside of the process cartridge into the housing cover A process cartridge comprising: a suction port; and a first air discharge port that communicates with the first air flow passage and discharges air. 2. The process cartridge according to claim 1, wherein the developing device has a second air flow passage in a direction of the drive shaft, and a second air suction port that sucks air from outside the process cartridge into the housing cover. 3. And a second air exhaust port for exhausting air in communication with the second air flow passage. 3. The process cartridge according to claim 1, wherein the first air suction port and the first air discharge port are configured such that air sucked from the first suction port passes through a gear train surface of the drive shaft. The process cartridge is disposed in the housing cover so that air flows through the first air flow passage. 3. The process cartridge according to claim 1, wherein the second air suction port and the second air discharge port are configured such that air sucked from the second suction port passes through a gear train surface of the drive shaft. The process cartridge is disposed in the housing cover so that air flows through the second air flow passage. An image forming apparatus comprising a plurality of process cartridges according to claim 1.

Images