JP6540176B2 - Developing device, process cartridge and image forming apparatus - Google Patents

Description

The present invention is now ZoSo location relates profile processes cartridge and an image forming apparatus.

In electrophotographic image forming apparatuses such as copying machines and printers, various developing devices are used to develop an electrostatic latent image formed on an image carrier. As such a developing device, in addition to a developing device of a two-component developing method using a developer containing toner and a carrier, a developing device of a one-component developing method using only toner as a developer without using a carrier It has been known.
In these developing devices, an agitating member or a conveying member (hereinafter, a member having any function of stirring and / or conveying) used at a portion in contact with the developer or toner is used as a “stirring / conveying member”. The toner is charged by circulating or stirring the toner.

  If the stirring / conveying member is not kept at 40 to 50 ° C. or less, the heat of the stirring / conveying member transfers heat to the toner in the vicinity where it contacts the toner, whereby the toner is melted, and toner aggregates and the like Problems such as an abnormal image of the lens or locking of the rotary drive unit. In recent years, the toner has been fixed at a low temperature particularly from the viewpoint of energy saving, while the rotation speed of the stirring / conveying member is increased from the viewpoint of high productivity (speeding up of the device). Heat generation due to friction is becoming larger. Therefore, coexistence of each technology from the above-mentioned viewpoint is increasing in importance.

Therefore, there is already known a technology for dissipating the heat of the bearing by manufacturing the shaft and the bearing of the conveying screw using a material having good thermal conductivity and flowing the air flow around the bearing by the cooling fan (for example, patent) Reference 1).
Patent Document 1 discloses a technique for generating an air flow with a fan attached to a conveyance screw shaft to dissipate heat in the development housing for the purpose of dissipating heat in the development housing.

  However, the cooling fan alone can not obtain a sufficient cooling effect with respect to a local temperature rise of the bearing portion of the conveying screw, and there is a problem that the image quality is deteriorated due to the toner fixation and the generation of toner aggregates.

The present invention has been made in view of the above-described circumstances, and a main object of the present invention is to provide a developing device provided with a rotating member having a shaft member capable of suppressing a temperature rise due to friction between a shaft and a bearing portion. I assume.

In order to achieve the above object, the present invention has a shaft member slidably supported on a support when rotating, and has a function of stirring and transporting the developer or stirring and transporting the recovered developer. Rotating member provided with at least one of the following functions, wherein the shaft member includes a hollow member in which a liquid is enclosed to an end including at least a portion supported by the support portion. In the developing device, the developer is a one-component developer including only toner .

  According to the present invention, with the above configuration, it is possible to suppress the temperature rise of the contact sliding portion due to the friction between the shaft member and the support portion.

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view of the developing device in the image forming apparatus of FIG. 1 as viewed from the rear side. (A) is a perspective view of the image development apparatus of FIG. 2, (b) is an enlarged sectional perspective view of the principal part which fractures and shows the image development apparatus of (a). It is sectional drawing of the rotating shaft of the conventional conveyance screw, and its bearing part periphery. It is sectional drawing of rotation shafts, such as a conveyance screw of Embodiment 1-3, and its bearing part. FIG. 10 is a cross-sectional view of a two-component developing type developing device according to a third embodiment. FIG. 7 is a cross-sectional view of a photoconductor cleaning device according to a third embodiment.

  Hereinafter, embodiments of the present invention (hereinafter referred to as “embodiments”) including the embodiments will be described in detail with reference to the drawings. Throughout the respective embodiments and the like, components (members and components) having the same functions and shapes and the like are described once by the same reference numerals after the description unless there is a risk of confusion, and the description thereof is omitted. In order to simplify the drawings and the description, even components that should be represented in the drawings may not be omitted unless necessary.

(Embodiment 1)
A first embodiment in which the present invention is applied to a copying machine as an example of an image forming apparatus will be described with reference to FIG. FIG. 1 is a schematic block diagram of an image forming apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the image forming apparatus 500 includes an image forming unit (hereinafter referred to as a printer unit 100), a sheet feeding table (hereinafter referred to as a sheet feeding unit 200), and the printer unit 100 provided in the image forming apparatus main body. The scanner (hereinafter referred to as the scanner unit 300) attached to the
The sheet feeding unit 200 includes upper and lower two-stage sheet feeding cassettes 10a and 10b storing transfer sheets P as transfer sheets, and the uppermost transfer sheet P stacked on the sheet feeding cassettes 10a and 10b. And a sheet feeding roller 11 for feeding the sheet.

The printer unit 100 includes process cartridges 1 (Y, M, C, and K) as four process units, an intermediate transfer belt 7 as an intermediate transfer member moving in the direction of arrow A in FIG. An exposure device 6 and a fixing device 12 as a fixing unit are provided. The intermediate transfer belt 7 is configured to be stretched around a plurality of stretching rollers and to move in the direction of arrow A in FIG.
The suffixes Y, M, C, and K appended to the reference numerals of the four process cartridges 1 indicate specifications of yellow, magenta, cyan, and black members. The four process cartridges 1 (Y, M, C, and K) have substantially the same configuration except that the colors of the toners used are different from one another. Therefore, the suffixes Y, M, C, and K are omitted below. Explain.

  The process cartridge 1 integrally includes a drum-shaped photosensitive member 2 as a latent image carrier, a charging member 3 as a charging unit, a developing device 4 as a developing unit, and a photosensitive member cleaning device 5 as a cleaning unit and a cleaning unit. It is a unitized structure supported by the Each process cartridge 1 is detachable from the main body of the image forming apparatus by releasing a stopper member which is an attaching / detaching means disposed in each process cartridge 1.

  The photosensitive member 2 rotates clockwise in FIG. 1 as indicated by the arrow in FIG. The charging member 3 is a roller-shaped charging roller, which is in pressure contact with the surface of the photosensitive member 2 and is driven to rotate by the rotation of the photosensitive member 2. At the time of image formation, a predetermined charging bias is applied to the charging member 3 by a high voltage power source, and the surface of the photosensitive member 2 is uniformly charged. Although the process cartridge 1 of Embodiment 1 uses the roller-shaped charging member 3 in contact with the surface of the photosensitive member 2 as the charging means, the charging means is not limited to this, and the charging means may not be corona charging or the like. A contact charging system may be used.

The exposure device 6 exposes the surface of the photosensitive member 2 on the basis of the image information of the document image read by the scanner unit 300 or the image information input from an external device such as a personal computer. Form an electrostatic latent image. The exposure device 6 included in the printer unit 100 uses a laser beam scanner method using a laser diode, but other configurations such as an LED array may be used as the exposure unit.
The photoreceptor cleaning device 5 cleans the transfer residual toner remaining on the surface of the photoreceptor 2 which has passed the position facing the intermediate transfer belt 7.

  The four process cartridges 1 form toner images of the respective colors yellow, magenta, cyan and black on the photosensitive member 2. The four process cartridges 1 are disposed in parallel in the surface movement direction of the intermediate transfer belt 7, and transfer the toner images formed on the respective photosensitive members 2 so as to sequentially overlap the intermediate transfer belt 7 A visible image is formed on the belt 7.

  In FIG. 1, a primary transfer roller 8 as a primary transfer unit is disposed at a position opposite to each photosensitive member 2 with the intermediate transfer belt 7 interposed therebetween. A primary transfer bias is applied to the primary transfer roller 8 by a high voltage power source, and forms a primary transfer electric field with the photosensitive member 2. By forming a primary transfer electric field between the photosensitive member 2 and the primary transfer roller 8, the toner image formed on the surface of the photosensitive member 2 is transferred to the surface of the intermediate transfer belt 7. The intermediate transfer belt 7 is surface-moved in the direction of the arrow A in the figure by rotationally driving one of the plurality of stretching rollers stretching the intermediate transfer belt 7 by the drive motor disposed. The full color image is formed on the surface of the intermediate transfer belt 7 by sequentially overlapping and transferring the toner images of the respective colors on the surface of the intermediate transfer belt 7 moving on the surface.

  With respect to the position where the four process cartridges 1 face the intermediate transfer belt 7, the intermediate transfer is performed on the secondary transfer counter roller 9a which is one of the stretching rollers at the downstream side of the surface transfer direction of the intermediate transfer belt 7. A secondary transfer roller 9 is disposed at a position opposite to and across the belt 7. A secondary transfer nip is formed between the secondary transfer roller 9 and the intermediate transfer belt 7, and a predetermined voltage is applied between the secondary transfer roller 9 and the secondary transfer opposing roller 9a to perform secondary transfer. Form an electric field. Then, based on a signal output from the control unit to feed the transfer sheet P from one of the sheet feeding cassettes 10a and 10b in the sheet feeding unit 200, the transfer sheet P is transferred from either one of the sheet feeding cassettes 10a and 10b. Is fed. Next, when the transfer paper P conveyed in the direction of arrow S in FIG. 1 passes the secondary transfer nip, the full color image formed on the surface of the intermediate transfer belt 7 is secondary to the secondary transfer roller 9. The image is transferred onto the transfer paper P by the secondary transfer electric field formed between the transfer opposing roller 9a and the transfer paper P.

A fixing device 12 is disposed downstream of the secondary transfer nip in the conveyance direction of the transfer sheet P. The transfer paper P having passed through the secondary transfer nip reaches the fixing device 12, and the full-color image transferred onto the transfer paper P is fixed by the heating and pressure in the fixing device 12, and the transfer paper P on which the image is fixed is The image is output to the outside of the image forming apparatus 500.
On the other hand, the toner remaining on the surface of the intermediate transfer belt 7 without being transferred to the transfer paper P at the secondary transfer nip is collected by the transfer belt cleaning device 13.

  As shown in FIG. 1, above the intermediate transfer belt 7, toner bottles 400 (Y, M, C, K) containing toners of respective colors are arranged detachably with respect to the image forming apparatus main body. The toner, which is a developer stored in the toner bottle 400 of each color, is developed by the toner replenishing device corresponding to each color (the device connecting the toner bottle 400 of each color and the developing device 4 corresponding to each color) 4 is supplied. The developing device 4 of the present embodiment is a one-component developing system, and a one-component developer composed of only toner is used as a developer. Further, as the toner, one that can be fixed at low temperature is used.

  The developing device in the image forming apparatus of FIG. 1 will be described with reference to FIGS. 2, 3A, and 3B. 2 is a schematic cross-sectional view of the developing device in the image forming apparatus of FIG. 1 as viewed from the rear side, FIG. 3A is a perspective view of the developing device of FIG. 2, and FIG. It is an enlarged section perspective view of the principal part which fractures and shows the development device of (a).

  As shown in FIGS. 2, 3A, and 3B, the developing casing 41 forming the outer shape of the developing device 4 is formed by combining the upper case 411, the middle case 412, and the lower case 413. Ru. The middle case 412 forms a toner storage portion 43. In the upper case 411, a toner replenishing port 55, which is a developer replenishing portion for communicating the toner accommodating portion 43 with the outside, is formed. Further, the upper case 411 is provided with an inlet seal 47 for sealing the gap between the developing roller 42 and the upper case 411.

The middle case 412 is provided with a developing roller 42, a supply roller 44, a doctor blade 45, a paddle 46, a conveying screw 48, a toner remaining amount sensor 49, and the like.
The developing device 4 is provided with an opening 56 communicating the inside with the outside along the longitudinal direction (Y-axis direction in the drawing). In the opening 56, a cylindrical developing roller 42 for carrying and conveying the toner T as a one-component developer from the inside to the outside (developing area α facing the photosensitive member 2 shown by a two-dot chain line in FIG. 2) It is provided. The developing roller 42 functions as a developer carrier that carries the toner T and supplies the toner T to the photoconductor 2.

  In the developing device 4, the supply roller 44 rotates in the direction of the arrow A1 in FIG. 2 (clockwise direction in FIG. 2) to move the surface, whereby the toner T in the toner container 43 faces the developing roller 42. The toner is conveyed to the supply nip portion β which is an area, and the toner is supplied to the surface of the developing roller 42. The developing roller 42 carries the supplied toner on the surface, and rotates in the direction of arrow B in FIG. 2 (clockwise direction in FIG. 2) to move the surface, whereby the toner on the developing roller 42 is transferred. The toner is conveyed to a portion opposed to the doctor blade 45 regulated to a predetermined amount. The toner regulated to a predetermined amount at the portion facing the doctor blade 45 reaches the developing region α which is the portion facing the photosensitive member 2 by the rotation of the developing roller 42.

  In the developing device 4 of the present embodiment, the surface movement direction of the developing roller 42 and the surface movement direction of the supply roller 44 are opposite in the supply nip portion β where the development roller 42 and the supply roller 44 face each other. As a result, the difference in linear velocity between the surface of the developing roller 42 and the surface of the supply roller 44 in the supply nip portion β is increased, and the collection performance of the supply roller 44 in the supply nip portion β can be improved. Therefore, it is possible to suppress the toner from being supported by the developing roller 42, to suppress the toner from adhering to the surface of the developing roller 42, and to cause the developer to adhere to the surface of the developer carrier. It is possible to suppress the occurrence of uneven density during development.

Further, as shown in FIG. 2, in the developing device 4, the supply roller 44 is disposed above the toner storage portion 43, and at least a portion of the supply roller 44 stops the rotation of the paddle 46. It is higher than the agent surface Ta which is the powder surface of the toner T. The area downstream of the supply roller 44 in the surface movement direction with respect to the supply nip portion β (hereinafter referred to as the supply nip downstream area) is above the application surface Ta of the toner T. When the downstream region of the supply nip is filled with toner, the toner in the state of being filled in the downstream region of the supply nip inhibits new toner from entering the downstream region of the supply nip, and There is a possibility that the collection efficiency of the toner from the developing roller 42 may be reduced.
On the other hand, in the developing device 4 of the present embodiment, as shown in FIG. 2, the downstream region of the supply nip is above the agent surface Ta of the toner T, so the downstream region of the supply nip is filled with toner. Not. Therefore, the toner present in the downstream region of the supply nip does not inhibit the collection of the toner from the developing roller 42 in the supply nip portion β, and the toner can be efficiently collected, and the toner reset property Can be improved.

  The conveying screw 48 has a function of stirring and conveying the toner supplied from the toner supply port 55, that is, both functions of a toner stirring member and a toner conveying member, and functions as a rotating member of the present invention. The transport screw 48 is also referred to as a feed screw.

Before describing the shaft portion of the conveying screw 48 which is a characteristic configuration of the present invention, the shaft portion of a conventional conveying screw 148 will be described first with reference to FIG. 4 in order to clarify the characteristics. FIG. 4 is a cross-sectional view around the rotation shaft of the conventional conveyance screw and its bearing portion. In FIG. 4, for simplification of the drawing, the middle case 412 of the developing casing only shows the lower portion to which the bearing unit 50 is attached and fixed, and the upper portion is omitted (the same applies to FIG. ).
The conventional conveying screw 148 is disposed at the same site in place of the conveying screw 48 of FIG. 2 showing the first embodiment, and as shown in FIG. It consists of a screw 150 integrally fixed to the outer peripheral portion of the shaft 149. Both end portions of the rotary shaft 149 (represented by one end on the right side in the figure below) are rotatably and slidably supported by a bearing member 51 including a seal member 52 which is a bearing portion 50. The bearing portion 50 formed of the bearing member 51 including the seal member 52 is mounted and fixed to the middle case 412 of the developing casing.

The seal member 52 is a so-called grease-less seal member to have a sealing property to prevent the leakage of the developer and to prevent a lubricant such as grease from being mixed in the developer. The sealing member 52 has sealing properties and lubricating performance, and is excellent in heat resistance, abrasion resistance, and chemical resistance, and is formed mainly of, for example, polytetrafluoroethylene resin (PTPF resin).
The bearing member 51 has lubricating performance and is excellent in heat resistance, abrasion resistance, and chemical resistance, and is formed of, for example, polyacetal resin (POM resin) or the like.

  The transport screw 148 circulates the developer, and operates in a state where the developer is in contact with the rotating shaft 149 and the bearing member 51 and the seal member 52 (hereinafter referred to as the bearing portion 50). When the transport screw 148 rotates, since the rotary shaft 149 slides while rotating between the bearing member 51 and the seal member 52, the sliding friction increases during driving, and heat is generated at this portion.

  The transport screw 148 of FIG. 4 was replaced with the transport screw 48 of the developing device 4 of FIG. As an experimental condition, the toner having the property of not causing toner aggregation up to 47 ° C. was used, and was carried out under an environment of 23 ° C. As a result of the experiment, when the conveying screw 148 was continuously driven at 900 rpm, the temperature of the rotating shaft 149 in the bearing unit 50 exceeded 51 ° C. at the operation for 2 hours, and a large amount of toner aggregates were generated. The operation was continued further, and after reaching 57 ° C. by driving for 3 hours, it was temporarily stopped, and after 30 minutes, it was tried to operate again, but the transport screw 148 was locked and could not be operated.

  As described in the background art above, if the stirring / conveying member is not kept at 40 to 50 ° C. or less, the toner is melted, causing problems such as abnormal images such as toner aggregates and locking of the rotation driving unit It will In recent years, the toner has been fixed at a low temperature particularly from the viewpoint of energy saving, while the rotation speed of the stirring / conveying member is increased from the viewpoint of high productivity (speeding up of the device). Heat generation due to friction is becoming larger. Therefore, coexistence of each technology from the above-mentioned viewpoint is increasing in importance.

So, in Embodiment 1 of the present invention, it is a shaft member that is used for a rotating mechanism and is slidably supported by the support when it rotates, and the temperature due to the friction between the shaft and the bearing including the seal member. We have developed a shaft member that can suppress the rise.
The conveying screw 48 of the first embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view around the rotation shaft of the conveyance screw of the first embodiment and its bearing portion.
As shown in FIGS. 2 and 5, the conveying screw 48 includes a rotating shaft 20 and a screw 30 integrally fixed to an outer peripheral portion of the rotating shaft 20. Both end portions of the rotary shaft 20 (represented by one end on the right side in the drawings below) are rotatably and slidably supported by a bearing member 51 including a seal member 52, which is a bearing portion 50 as a support portion of the present invention. It is done.

The conveying screw 48 is different from the conventional conveying screw 148 shown in FIG. 4 only in that it uses a rotating shaft 20 as a shaft member having a unique internal structure instead of the rotating shaft 149. The rotating shaft 20 includes a hollow portion 21 in which water as an example of the liquid 22 and air as an example of the gas 23 are sealed. Water as the liquid 22 is about half filled and sealed at a volume ratio of the hollow portion 21. Both end portions of the hollow portion 21 in the rotation shaft 20 are formed to have a length extending from the bearing portion 50 as shown in FIG. 5, and both ends of the rotation shaft 20 are closed (sealed).
The hollow portion 21 of the rotating shaft 20 can be formed relatively easily if, for example, a hollow shaft formed in a pipe shape in advance is used, as long as it is made of a metal having a relatively high thermal conductivity. Moreover, if it is a thing made of resin, if it is made to enclose a liquid inside at the time of blow molding using a blow molding method, it can form comparatively easily.

The experiment was performed on the transport screw 48 of the first embodiment under the same experimental conditions as the conventional transport screw 148 described above. The rotating shaft 20 used in this experiment was a pipe made of stainless steel (SUS) made of metal. As a result of the experiment, the temperature of the rotating shaft 20 of the bearing unit 50 after driving for 3 hours is 42 ° C., and the temperature is lowered by 15 ° C. compared to the conveying screw 148 of the conventional configuration. Also did not occur.
The effects are as follows. That is, the heat generated by the sliding friction between the rotary shaft 20 and the bearing portion 50 moves to the rotary shaft 20 portion in contact with the bearing portion 50, and further, the liquid sealed in the hollow portion 21 of the rotary shaft 20 ( Move to the water). Then, the liquid (water) in the hollow portion 21 moves in the hollow portion 21 (rotational movement in the length direction and the radial direction of the rotary shaft 20) as the rotary shaft 20 rotates, whereby heat is dispersed. Thereby, the local temperature rise of the contact sliding part of the rotating shaft 20 and the bearing part 50 is suppressed.
Thereby, even when using a low temperature fixing developer in which toner aggregates are likely to be generated even at low temperatures, it is possible to prevent the generation of toner aggregates in advance, and an image forming apparatus, process cartridge, and developing device capable of obtaining stable image quality , A rotating member, a shaft member, and thus a cleaning device.

  The rotary shaft 20 of the transport screw 48 of the first embodiment and the rotary shaft 149 of the conventional transport screw 148 are made of stainless steel (SUS) made of metal with relatively good thermal conductivity, but the resin It may be made of For example, the rotation shaft 20 of the transport screw 48 may be formed of resin using a blow molding method, and liquid may be enclosed inside at the time of blow molding.

  The rotary shaft 20, which is a shaft member of the first embodiment, is not limited to the one disposed on the conveyance screw 48, but may be disposed on the recovered toner conveyance screw 60 provided in the photosensitive member cleaning device 5 shown in FIG. Thus, it is possible to achieve the above-described effects. In this case, the recovered toner transport screw 60 transports a waste toner (residual toner on the photosensitive member 2) which is a developer removed and recovered by a cleaning blade as a cleaning blade member provided in the photosensitive member cleaning device 5 Function as a rotating member. In other words, the recovered toner conveying screw 60 functions as a waste toner conveying member or a waste toner stirring member, and has the rotating shaft 20 and the screw 30.

  As shown in FIG. 5, the rotary shaft 20 disposed on the recovered toner conveyance screw 60 shown in parentheses is disposed on the photosensitive member cleaning device 5 and mounted on the cleaning case 61 shown in parentheses It is slidably and rotatably supported by the fixed bearing portion 50.

Second Embodiment
Second Embodiment A shaft member according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment only in that a rotation shaft 20A as a shaft member is used in place of the rotation shaft 20 as a shaft member. Hereinafter, the rotation shaft 20A of the second embodiment will be described focusing on the differences.
The rotary shaft 20A of the second embodiment is mainly limited to the highly volatile liquid having a boiling point of 30 to 50 ° C. of the liquid 22 sealed in the hollow portion 21 as compared with the rotary shaft 20 of the first embodiment. It is different. Examples of the highly volatile liquid having a boiling point of 30 to 50 ° C. of the liquid 22 include diethyl ether having a boiling point of 34.6 ° C. The point at which the boiling point of the liquid 22 is 30 to 50 ° C. is a standard of the normal temperature or more and less than the temperature at which the toner is not damaged.

  The rotating shaft 20A is internally provided with a hollow portion 21 in which air as an example of the gas 23 is enclosed, together with a liquid such as highly volatile diethyl ether having a boiling point of 30 to 50 ° C. of the liquid 22. The liquid 22 such as highly volatile diethyl ether is filled and sealed about half in volume ratio of the hollow portion 21. As shown in FIG. 5, both end portions of the hollow portion 21 in the rotation shaft 20A are formed to have a length extending at least from the bearing portion 50, and both ends of the rotation shaft 20A are closed (sealed) .

In FIG. 5, when the temperature of the sliding contact portion between the rotating shaft 20A and the bearing portion 50 reaches the boiling point of the liquid 22, heat is released due to vaporization heat due to boiling of the liquid 22 at that portion, leaving the bearing portion 50 A thermal cycle of liquefying at normal temperature is performed inside the rotary shaft 20A at the above position. Thereby, the temperature at the contact sliding portion between the rotary shaft 20A and the bearing portion 50 is lowered more effectively, and the local temperature rise of the contact sliding portion between the rotary shaft 20 and the bearing portion 50 is more reliable Suppressed.
Therefore, an image forming apparatus, a process cartridge, a developing device, and a cleaning device capable of preventing generation of toner aggregates in advance and obtaining stable image quality even when using a low-temperature fixing developer which generates toner aggregates , Rotating members, shaft members.

  It goes without saying that the rotation shaft 20A, which is the shaft member of the second embodiment, can be applied to the transport screws 48 and 60 of the first embodiment instead of the rotation shaft 20 of the first embodiment.

(Embodiment 3)
Third Embodiment A third embodiment in which the present invention is applied to a two-component developing type developing device 4A and a photosensitive member cleaning device 5A will be described with reference to FIGS. FIG. 6 is a cross-sectional view of a two-component developing type developing device 4A, and FIG. 7 is a cross-sectional view of a photosensitive member cleaning device 5A.
The rotating shafts 20 and 20A which are shaft members of Embodiments 1 and 2 are not limited to those provided on the conveying screws 48 and 60, but are provided in the developing device 4A of the two-component developing system and the photoconductor cleaning device 5A. The present invention can be applied to a rotating member to achieve the above-described effects.

  The third embodiment is different from the image forming apparatus shown in FIG. 1 in that the developing device 4A uses a two-component developer including toner and a carrier instead of the developing device 4 using a one-component developer. And the photosensitive member cleaning device 5 is replaced with a photosensitive member cleaning device 5A. Hereinafter, the developing device 4A and the photosensitive member cleaning device 5A of the third embodiment will be described focusing on the differences.

The developing device 4A rotates the supply chamber stirring and conveying screw 304, the collection chamber stirring and conveying screw 305, the developing roller 302, etc. for stirring and conveying the two-component developer G including the toner T and the carrier C in the developing casing 301. A member and other members are provided. The supply chamber stirring and conveying screw 304 and the recovery chamber stirring and conveying screw 305 function as a rotating member of the present invention.
The developing roller 302 is closely disposed so as to form a developing region α by bringing the developing roller 302 into close proximity to and facing the photosensitive member 2. The portion of the developing casing 301 corresponding to the portion facing the photosensitive member 2 is opened to expose the developing roller 302. The developer G in the developing casing 301 is conveyed to the developing area α by the developing roller 302. The toner in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive member 2 in the development region α, and is visualized as a toner image.

The developing device 4A has a developing roller 302, a feeding chamber stirring and conveying screw 304, a collecting chamber stirring and conveying screw 305, and a developer regulating member 303 inside the developing casing 301, and stirs, conveys and circulates the developer G. . In the supply chamber stirring and conveying screw 304 and the recovery chamber stirring and conveying screw 305, a screw having a spiral shape is integrally fixed to the outer peripheral portion of the rotation shaft 20 having the same configuration as that of the first embodiment.
The developing roller 302 internally includes a magnet roller in which a plurality of magnets are arranged in the circumferential direction, and a cylindrical sleeve rotates integrally with the rotation shaft 302e. In FIG. 6, reference numeral 303 denotes a developer restricting member 303, reference numeral 306 denotes a partition plate, reference numeral 307 denotes an opening 307 formed in the partition plate 306, reference numeral 309 denotes an agent release area, and reference numeral 310 denotes an agent pumping area. Are shown respectively.

The detailed configuration of the developing device 4A is similar to, for example, FIGS. 1 to 6 of JP-A No. 2003-263012 except for the respective rotation shafts 20 and 20A of the supply chamber stirring and conveying screw 304 and the recovery chamber stirring and conveying screw 305. , I omit detailed explanation more than this.
As shown in FIG. 5, the rotation shafts 20 and 20A disposed in the supply chamber stirring and conveying screw 304 and the collection chamber stirring and conveying screw 305 shown in parentheses are disposed in the developing device 4A shown in FIG. It is slidably and rotatably supported by a bearing unit 50 attached and fixed to the developing casing 301 shown in parentheses.

  The photosensitive member cleaning device 5A is disposed at a position close to the photosensitive member 2 as shown in FIG. The photosensitive member cleaning device 5A includes a cleaning blade 62 for removing the toner remaining on the surface of the photosensitive member 2 without being completely transferred to the transfer sheet, and a transport screw 65 for collecting and transporting the toner removed by the cleaning blade 62. Is provided in the cleaning case 64. The conveying screw 65 functions as a rotating member of the present invention.

  As shown in FIG. 5, the rotating shafts 20 and 20A disposed on the conveying screw 65 shown in parentheses are disposed on the photosensitive member cleaning device 5A shown in FIG. It is slidably and rotatably supported by a bearing unit 50 attached and fixed to the case 64.

In the first to third embodiments, the shaft member of the present invention is applied to the transport screws 48 and 65, the recovered toner transport screw 60, the supply chamber stirring transport screw 304, the recovery chamber stirring transport screw 305, etc. as specific rotating members. Although described, the rotating members applied are not limited to these.
For example, in the developing device 4 shown in FIG. 2, it is needless to say that the invention can be applied to each axis of the supply roller 44 which is a toner supply member and the paddle 46 which is a toner stirring member. That is, in an image forming apparatus, it is used for a rotating mechanism provided in a developing device or a cleaning device associated with a device in contact with toner in a developer, and slides on a supporting portion such as a bearing when rotating. It can also be applied to the shanks of various rotating members, which have a possibly supported axis.
Further, the shaft portion 42a of the developing roller 42 shown in FIG. 2 and the shaft portion of the developing roller 302 shown in FIG.

  The rotating member may have at least one of the functions of stirring and conveying the developer regardless of the one-component and two-component developers.

As described above, it can be said that the following first to eleventh technical configurations are substantially described in the first to third embodiments. That is, the first technical configuration is a shaft member such as a rotating shaft 20 which is used for a rotating mechanism and slidably supported by a supporting portion such as the bearing 50 when rotating, and the shaft member is The shaft member includes a hollow portion such as a hollow portion 21 in which a liquid such as the liquid 22 is sealed.
According to the first technical configuration, it is possible to suppress the temperature rise of the contact sliding portion due to the friction between the shaft member and the support portion.

In the second technical configuration, in the first technical configuration, the boiling point of the liquid is 30 to 50 ° C., and the hollow portion is a shaft member such as a rotating shaft 20A in which a gas is enclosed together with the liquid.
According to the second technical configuration, it is possible to more reliably suppress the temperature rise of the contact sliding portion due to the friction between the shaft member and the support portion.

The third technical configuration has the shaft member of the first or second technical configuration, and has at least one of the functions of stirring and conveying the developer, the supply roller 44, the paddle 46, the conveying screw 48, It is a rotating member such as the supply chamber stirring and conveying screw 304 and the recovery chamber stirring and conveying screw 305.
The fourth technical configuration has a shaft member of the first or second technical configuration, and has at least one function of a function to agitate and transport the recovered developer, a recovery toner transport screw 60, a transport screw 65 or the like.

According to a fifth technical configuration, in the third or fourth technical configuration, the developer is a one-component developer including only toner.
According to a sixth technical configuration, in the third or fourth technical configuration, the developer is a two-component developer including toner and a carrier.

A seventh technical configuration is a developing device having a rotating member according to any one of the third to sixth technical configurations.
According to the seventh technical configuration, since the temperature rise of the contact sliding portion due to the friction between the shaft member and the support portion can be suppressed, the generation of toner aggregates can be prevented in advance, and the stable image quality can be obtained. It becomes possible to obtain.

An eighth technical configuration is a cleaning device having a rotating member according to any one of the third to sixth technical configurations.
According to the eighth technical configuration, since the temperature rise of the contact sliding portion due to the friction between the shaft member and the support portion can be suppressed, it is possible to prevent the generation of the toner aggregate in advance.

The ninth technical configuration is a process cartridge having an image carrier and the developing device of the sixth technical configuration.
According to the ninth technical configuration, the workability of replacing consumables and the like is improved.
A tenth technical configuration is a process cartridge having an image carrier and the cleaning device of the eighth technical configuration.
According to the tenth technical configuration, the workability of replacing consumables and the like is improved.

An eleventh technical configuration is an image forming apparatus having the developing device of the seventh technical configuration, the cleaning device of the eighth technical configuration, or the process cartridge of the ninth or tenth technical configuration.
According to the eleventh technical configuration, stable image quality can be obtained.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and the present invention described in the appended claims unless otherwise specified in the above description. Various modifications and changes are possible within the scope of the present invention. For example, the technical matters described in the above embodiment, examples, and the like may be appropriately combined.

  For example, the liquid 22 moves in the direction of the rotation axis along with the rotation such as spiral processing in at least a part of the hollow portion 21 which is the hollow portion inside the rotation shafts 20 and 20A in the first and second embodiments shown in FIG. The shaft member may be processed to apply a force. According to the rotating shafts 20 and 20A as such shaft members, it is possible to enhance the circulation of the liquid 22 in the hollow portion 21 inside the rotating shafts 20 and 20A. Specifically, the liquid 22 in the hollow portion 21 inside the rotary shafts 20 and 20A is collected in the bearing portion 50 at the time of driving, and the liquid 22 in the hollow portion 21 is dispersed inside the rotary shafts 20 and 20A at the time of stop, It can be dispersed throughout 20, 20A. Thereby, the further temperature reduction effect in the contact sliding part of rotating shaft 20, 20A and the bearing part 50 is expectable.

  The image forming apparatus according to the present invention is not limited to the intermediate transfer type tandem type image forming apparatus shown in FIG. 1, but the direct transfer type tandem type image formation directly transferring onto a sheet held on a conveyance belt The apparatus may be an apparatus or an image forming apparatus that forms an image using a single image carrier.

  The effects appropriately described in the embodiments of the present invention only list the most preferable effects resulting from the present invention, and the effects by the present invention are limited to those described in the embodiments of the present invention It is not a thing.

1 Process cartridge 2 Photosensitive member (image carrier or latent image carrier)
3 charging member 4, 4A developing device 5, 5A photoconductor cleaning device (an example of the cleaning device)
6 Exposure device 7 Intermediate transfer belt 20, 20A Rotating shaft (example of shaft member)
21 hollow portion 22 liquid 23 gas 30 screw 41 developing casing 42 developing roller 46 paddle (an example of a rotating member)
48, 65 Conveying screw (an example of a rotating member)
50 Bearing (example of support)
51 bearing 52 seal member 60 collected toner conveying screw (an example of a rotating member)
61, 64 cleaning case 100 printer unit 200 sheet feeding unit 300 scanner unit 301 developing casing 301
304 Supply chamber stirring and conveying screw (an example of a rotating member)
305 Recovery chamber stirring and conveying screw (an example of a rotating member)
500 image forming apparatus T Toner (one-component developer)
G Developer (two-component developer)

JP, 2010-243681, A

Claims (8)

It has a shaft member slidably supported by the support when it rotates,
A rotating member having at least one of a function of stirring and transporting a developer or a function of stirring and transporting a recovered developer,
The shaft member includes a rotating member internally provided with a hollow portion in which liquid is sealed to an end including at least a portion supported by the support portion ,
The developing device, wherein the developer is a one-component developer including only toner . In the developing device according to claim 1,
The boiling point of the liquid is 30 to 50 ° C.,
It said hollow portion, a developing device, characterized in that the gas together with the liquid is sealed. In the developing device according to claim 1 or 2,
A developing device having a greaseless seal member at the support portion. It has a shaft member slidably supported by the support when it rotates,
A rotating member having at least one of a function of stirring and transporting a developer or a function of stirring and transporting a recovered developer,
The shaft member includes a rotating member internally provided with a hollow portion in which liquid is sealed to an end including at least a portion supported by the support portion,
A developing device characterized in that the developer is a two- component developer including a toner and a carrier . In the developing device according to claim 4 ,
The boiling point of the liquid is 30 to 50 ° C.,
In the hollow portion, a gas is enclosed together with the liquid . In the developing device according to claim 4 or 5 ,
A developing device having a greaseless seal member at the support portion . A process cartridge comprising an image carrier and the developing device according to any one of claims 1 to 6 . An image forming apparatus comprising the developing device according to any one of claims 1 to 6 or the process cartridge according to claim 7 .

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