JP2017037337A - Development device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a development device, a process cartridge and an image formation apparatus which are reduced in size and thickness.SOLUTION: A development device which develops a latent image formed on an image carrier includes: a developer carrier which is provided rotationally and carries a developer; a development container which forms a developer storage chamber for storing the developer; a developer regulation part which is provided in the development container and regulates the amount of the developer carried by the developer carrier; a support part which supports the developer carrier and can move the developer carrier with respect to the developer regulation part; and a pressure member which presses the developer carrier toward the developer regulation part. A contact portion of the developer regulation part with respect to the developer carrier is fixed to the development container without a gap with the development container on the downstream side in the pressing direction by the pressure member.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a developing device, a process cartridge, and an image forming apparatus.

  Here, the image forming apparatus forms an image on a recording medium, and includes, for example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic facsimile apparatus, and the like.

  The process cartridge is a cartridge in which at least the image carrier and the developing device are integrated into a cartridge and can be attached to and detached from the main body of the image forming apparatus. The developing device is a device that develops an electrostatic latent image formed on an image carrier.

  For example, an electrophotographic image forming apparatus (hereinafter referred to as an “image forming apparatus”) such as a copying machine or a laser beam printer irradiates an electrophotographic photosensitive member (photosensitive member) with light corresponding to image data. (Electrostatic latent image) is formed. Then, toner that is a developer is supplied from the developing device to the electrostatic image to be visualized as a toner image. This toner image is transferred from a photoreceptor to a recording medium such as recording paper by a transfer device. The toner image is fixed on a recording medium by a fixing device to form a recorded image.

  Various apparatuses have been proposed for developing apparatuses using the dry one-component developing method. One example is as follows. That is, in the developing device, toner that is a one-component developer is accommodated in the developing container. A toner is carried on a developing roller rotatably fixed to the developing container, and a toner layer having a uniform layer thickness is formed by a developer regulating member. The developing roller carrying the toner layer is brought close to or in contact with the photosensitive member, and a developing bias voltage composed of, for example, an alternating current component and a direct current component is applied to the developing roller, whereby the electrostatic image on the photosensitive member and the developing sleeve are applied. A potential difference is generated. Thus, development is performed by moving the toner to the electrostatic image.

  As a method for regulating the thickness of the toner layer formed on the developing roller, there is a method called a cantilever method as disclosed in Patent Document 1. In this method, a regulating blade having elasticity is used as a developer regulating member, and the regulating blade is fixed to the developing container so as to come into contact with the developer carrying member in a bent state. Since the pressure generated when the regulating blade is bent is used as the regulating pressure for regulating the developer, the desired regulating pressure can be stably obtained even if the mounting positions of the developer carrier and the developer regulating member vary.

  Further, as shown in Patent Document 2, there is a method in which a rigid body is used as the developer regulating member and a spring member is provided between the developer regulating member and the developing container. The developer regulating member is pressed against the developer carrying member from above by the spring member. Since the biasing pressure of the spring member is used as the developer regulating pressure, the desired regulating pressure can be stably obtained even if the mounting positions of the developer carrier and the regulating member vary.

JP-A-5-142933 Japanese Patent Laid-Open No. 9-21966

  In recent years, image forming apparatuses are required not only to improve image quality, but also to reduce the size of the apparatus, particularly to reduce its thickness.

  However, in the configuration of Patent Document 1, the regulating pressure of the developer is obtained by bending the regulating blade that is an elastic member. Therefore, as shown in FIG. 27, a space S1 for bending the regulating blade 23 between a fixing portion for fixing the regulating blade 23 to the developing container 22 and a developer regulating position 25 on the developer carrier 24. Is required.

  In the configuration of Patent Document 2, a rigid developer regulating member 28 and a spring member 29 are accommodated between the developer container 26 and the developer regulating position 27 above the developer carrying member 24 as shown in FIG. Space S2 is required.

  In view of the above problems, an object of the present invention is to provide a developing device and a process cartridge that are further downsized and thinned while maintaining the regulated pressure and regulated position of the developer.

A typical configuration of the present invention for solving the above problems is as follows.
In a developing device for developing a latent image formed on an image carrier,
A developer carrier that is rotatably provided and carries the developer;
A developer container forming a developer storage chamber for storing the developer;
A developer regulating unit that regulates the amount of developer that is provided in the developer container and carried on the developer carrying member;
A support part that supports the developer carrier and allows the developer carrier to move relative to the developer regulating part;
A pressure member for pressurizing the developer carrier toward the developer regulating portion;
With
The contact portion of the developer regulating portion with respect to the developer carrying member is fixed to the developer container without providing a gap with the developer container on the downstream side in the pressure direction by the pressure member. It is characterized by.

  As described above, according to the present invention, it is possible to provide a developing device and a process cartridge that are more downsized and thinner while stably regulating the developer carried on the developer carrying member.

Cross section of image forming apparatus Perspective view of developing device Top view of developing device Internal plan view of the developing device Cross-sectional view of developing device Cross section of development device Explanatory drawing of the pressurizing structure for the developing sleeve Cross-sectional view of developing device Cross section of development device (A) Cross-sectional view of developing device (b) Enlarged view of developer regulating region Cross section of development device Cross-sectional view of developing device (A) Sectional drawing of developing device. (B) Sectional view of developing device Illustration of insert processing Illustration of two-color molding process Explanatory drawing of the developer regulation section Explanatory drawing of the developer regulation section Cross section of development device Cross-sectional view of developing device (A) Explanatory drawing of movement restricting part (b) Explanatory drawing of magnet roller Illustration of bearing member Cross-sectional view of developing device Cross-sectional view of developing device The perspective view which shows a movement control part and a developer control part Explanatory drawing of the movement restriction part Explanatory drawing of the movement restriction part Illustration of conventional example Illustration of conventional example

[Example 1]
The schematic configuration of the image forming apparatus of this embodiment is shown in FIG. The image forming apparatus in the present embodiment is a monochrome laser beam printer that forms an image on a recording medium such as paper using an electrophotographic process.

  A drum-type photosensitive member 1 is disposed as an image carrier (hereinafter, referred to as a photosensitive drum 1) in the approximate center of the apparatus main body M of the image forming apparatus. The photosensitive drum 1 has an OPC (organic optical semiconductor) photosensitive layer formed on the outer peripheral surface of a conductive drum substrate such as aluminum, and is driven to rotate at a predetermined process speed (peripheral speed) of 200 mm / s.

  The surface (circumferential surface) of the above-described photosensitive drum 1 is uniformly (uniformly) charged to a predetermined polarity and potential by a charging roller 2 as a charging unit. The surface of the charged photosensitive drum 1 is exposed by a laser beam output from a laser beam scanner 3 as an exposure unit. This laser beam is modulated in accordance with the target image information and forms an electrostatic latent image on the photosensitive drum. The electrostatic latent image is developed as a toner image by attaching a toner 5 as a developer by a developing device 4 as a developing unit.

  The recording medium 9 is fed by a paper feed roller, and is sent to a transfer nip portion between the photosensitive drum 1 and the transfer roller 10 so as to be synchronized with the toner image written on the photosensitive drum 1, and the toner image on the surface. Is transcribed. A transfer transfer bias is applied to the transfer roller 10 from a transfer bias application power source (not shown) during transfer.

  The recording medium 9 that has received the transfer of the toner image is separated from the surface of the photosensitive drum 1 and conveyed to a fixing device 11 as fixing means, where it is heated and pressurized to fix the toner image on the surface. On the other hand, after the toner image has been transferred, the toner 5 remaining on the surface without being transferred to the recording medium 9 is removed by a cleaning member 12 as a cleaning means, and used for the next image formation.

  In the image forming apparatus according to the present embodiment, four process devices including the photosensitive drum 1, the charging roller 2, the developing device 4, and the cleaning member 12 are integrally incorporated, and are detachable from the apparatus main body M. (Process Unit) 13 is configured.

(Overview of development device configuration)
The developing device, which is a feature of this embodiment, will be described with reference to FIGS. FIG. 2 is an external perspective view of the developing device 4 in this embodiment. FIG. 3 is a plan view of the developing device. FIG. 4 is a plan view of the developing device 4 with the ceiling plate 14g of the developing container 14 removed in FIG. FIG. 5 shows the process cartridge of this embodiment.

  In the following description, the front side of the developing device 4 is the side where the developing sleeve faces the photosensitive drum as the image carrier. The near side or the front side or the front side is also synonymous with the front side. The back side is the side opposite to the front side. The back side, the back side, or the back side is also synonymous with the back side. Left and right are left or right when viewed from the front. Up and down are up or down in the direction of gravity. The longitudinal direction is the axial direction of the rotating body or a direction parallel to the axial direction. When L or R is added to the end of the reference sign, it indicates that the member is provided on the left side (L) or the right side (R) of the developing device unless otherwise specified.

  In this embodiment, a developing sleeve 6 as a developer carrier is provided in the developing device 4. A gap of about 300 μm is provided between the developing sleeve 6 and the photosensitive drum 1, and a developing bias voltage that is a superimposed voltage of direct current and alternating current is applied to the developing sleeve 6 by the developing bias power source 7 during development. Specifically, in this embodiment, a superimposed voltage having an AC component frequency of 2.5 kHz, an amplitude of 1.6 kV, and a DC component of −400 V was applied. The toner 5 is transferred from the developing sleeve 6 to the electrostatic image formed on the photosensitive drum 1 by the action of the developing bias.

  As shown in FIGS. 2, 3, and 4, ring-shaped spacers concentrically with the developing sleeve 6 are attached to both ends of the developing sleeve 6. The spacer has a thickness of 300 μm, and maintains a gap between the photosensitive drum 1 and the developing sleeve 6 at 300 μm by contacting the photosensitive drum 1. When the direction in which the photosensitive drum 1 is pressed against the developing sleeve 6 is a drum pressing direction B (see FIG. 5), the drum pressing direction B in this embodiment is a direction connecting the centers of the photosensitive drum 1 and the developing sleeve 6. is there.

  The developing sleeve 6 is driven to rotate by a drive gear 17 attached to one end (driving side end), driven by an image forming apparatus main body M (not shown). In the following description, in the longitudinal direction of the developing sleeve 6, the side on which the sleeve driving gear 17 is provided on the developing sleeve 6 may be called a driving side, and the side opposite to the driving side may be called a non-driving side.

  In the developing device 4 of this embodiment, a toner 5 as a developer is stored in a developer storage chamber 14 a formed by the developing container 14. The developing container 14 is molded with a high impact polystyrene resin (HI-PS), the toner 5 is a magnetic toner, and the regular charging polarity (normal polarity), that is, the polarity charged during image formation is negative. is there. Further, a developing sleeve 6 as a developer carrying member is rotatably disposed in an opening 14b (see FIG. 2) of the developing device 4 facing the photosensitive drum 1.

  As shown in FIG. 4, a left inner plate 14 dL extending in the front-rear direction is provided at a position close to the left plate 14 cL of the developer container 14 with a predetermined interval inside the developer container 14. Further, a right inner plate 14dR extending in the front-rear direction is provided at a position close to the right plate 14cR of the developing container 14 with a space therebetween. The developing sleeve 6 is disposed in the opening 14b (see FIG. 2) on the front side of the developing container 14 so as to be rotatable by the left and right bearing mechanisms 18 (18L and 18R) with the axial direction set to the left and right.

  In the present embodiment, in the developing container 14, a closed space portion surrounded by the bottom plate 14e, the left inner plate 14dL, the right inner plate 14dR, the rear plate 14f, the ceiling plate 14g, and the developing sleeve 6 of the developing container 14. Is a developer storage chamber 14a.

  In the developing container 14 of the present embodiment, as shown in FIG. 5, the toner in the developer containing chamber 14a is formed such that the substantially rear half of the bottom plate 14e is inclined downward from the rear plate 14f side to the developing sleeve 6 side. 5, the fluidity of moving toward the developing sleeve 6 is generated. A rotationally driven paddle member (toner stirring / conveying member) that stirs the toner 5 and positively moves it toward the developing sleeve can be disposed in the developer storage chamber 14a.

  In FIG. 4, W6 is the entire width of the developing sleeve 6 (sleeve portion 6a) (the entire length of the developing sleeve 6). The distance between the left and right spacers 8L and 8R also substantially corresponds to the full width W6 of the developing sleeve. W1 is the entire width of the drum 1 (the entire length of the drum 1), and is larger than the interval W6 between the spacers 8L and 8R.

  W6d is a developer supply area width in the developing sleeve 6, and W6e is a developer non-supply area width. The developer supply area width W6d substantially corresponds to the maximum image forming area width in the drum 1. In the present embodiment, the developer supply region width W6d is defined by the interval between the left inner plate 14dL and the right inner plate 14dR of the developing container 14. The entire width of the developer restricting portion 16 (the total length of the developer restricting portion 16) W16 substantially corresponds to the developer supply region width W6d. The developer non-supply area width W6e is a width of the developing sleeve surface portion corresponding to the outside of the interval between the left inner plate 14dL and the right inner plate 14dR.

  No. 20 (20L / 20R) is provided between the front side of the left inner plate 14dL and the developing sleeve 6 and between the front side of the right inner plate 14dR and the developing sleeve 6 to prevent the toner 5 from leaking through the gap. It is a sealing member.

The developing sleeve 6 of this embodiment is obtained by forming a conductive resin layer containing a binder resin, conductive fine powder, and rough particles on a cylindrical aluminum base tube having a diameter of 16 [mm]. A resistor having a resistance of 10 ⁻² to 10 ⁴ [Ωcm] was used. A phenol resin was used as the binder resin, carbon black and graphite were used as the conductive fine powder, and spherical carbonized particles were used as the roughened particles.

  As shown in FIG. 5, a magnet roller 15 is fixedly disposed in the developing sleeve 6 as a magnetic field generating means for generating a magnetic field. The toner 5 is attracted and taken in on the developing sleeve 6 by the magnetic force of the magnet roller 15.

  As described above, the developing sleeve 6 is rotatably arranged, and the toner 5 attracted onto the developing sleeve 6 is regulated by the developer regulating unit 16 by rotating in the arrow R1 direction. The developer regulating unit 16 is a part of the developing container 14. That is, the developer regulating portion 16 is formed integrally with the developing container 14.

  In this embodiment, the toner 5 on the developing sleeve 6 is regulated to a desired amount by rotating the developing sleeve 6 while applying pressure to the developer regulating portion 16 provided in the developing container 14. The surface of the developer restricting portion 16 is almost smooth and the surface roughness Ra = 0.15 μm. The surface roughness of the developing sleeve is Ra = 1.2 μm. The surface roughness Ra is an arithmetic average roughness (centerline average roughness) [μm] defined in JIS-B0601-1994, and a contact surface roughness measuring instrument SE3500 (manufactured by Kosaka Laboratory Ltd.). And measured under the following conditions.

Reference length: 0.8 [mm]
Evaluation length: 4.0 [mm]
Feeding speed: 0.1 [mm]
Filter: Gauss In the present embodiment, the contact pressure when the developing sleeve 6 contacts the developer regulating portion 16 is 30 g / cm as a linear pressure. The contact pressure is a value obtained by the following procedure. Spring pressure when three SUS sheets (thickness 50 μm, width w [cm]) are inserted between the contact nip between the developing sleeve 6 and the developer regulating portion 16 without toner and the middle sheet is pulled out. F [gf] is measured. The coefficient of friction μ between the SUS sheets is measured. Then, the contact pressure (linear pressure) P = μF / w is obtained.

In the above configuration, the amount of charge (the amount of charge per unit weight) of the toner carried on the developing sleeve 6 after passing through the developer regulating portion 16 is 10 μC / g. The amount of toner carried on the developing sleeve 6 (weight per unit area) after passing through the developer regulating portion 16 was 15 g / m ² .

  A movable and pressurizing mechanism of the developing sleeve 6 will be described with reference to FIGS. As shown in FIG. 5, the developing sleeve 6 is pressurized by an elastic member (hereinafter referred to as a spring member) 19 as a pressing member at the end in the longitudinal direction thereof, and is a part of the developing container 14. It is pressed against the agent regulating part 16. The longitudinal direction of the developing sleeve 6 is a direction (axial direction) parallel to the rotation axis of the developing sleeve 6.

  6 is a cross-sectional view taken along dotted line L in FIG. As shown in FIG. 6, the developing sleeve 6 is pressurized by spring members 19 at both ends in the longitudinal direction.

  The developing sleeve 6 is rotatably attached to the bearing mechanism 18. The bearing mechanism 18 includes a guide member 18b and a bearing member 18a guided by the guide member 18b. The bearing member 18 a is a support portion that supports the shaft of the developing sleeve 6. One end 19a of the spring member 19 is attached to the bearing member 18a. On the other hand, the other end 19 b of the spring member 19 abuts against the developing container 14. The spring member 19 presses the developing sleeve 6 against the developer regulating portion 16 via the bearing member 18a.

  Here, as shown in FIG. 6, the developing sleeve 6 has a cylindrical shape, and a sleeve portion (carrying portion) 6a that is a portion for carrying toner, and a shaft portion 6c (with a smaller diameter than the sleeve portion 6a). 6cL · 6cR). The developing sleeve 6 has left and right end plate portions 6bL and 6bR that close the left and right openings of the sleeve portion 6a. The shaft portion 6c is concentric with the sleeve portion 6a, and the outer diameter is smaller than the outer diameter of the sleeve portion 6a. The bearing member 18a rotatably supports the developing sleeve 6 at the shaft portion 6c.

  Therefore, as shown in FIG. 5, when the developing device 4 is viewed along the longitudinal direction of the developing sleeve 6, one end portion 19a of the spring member 19 attached to the bearing member 18a is located inside the outer periphery of the sleeve portion 6a. Located in. The region S3 occupied by the spring member 19 in the developing container 14 substantially overlaps the region occupied by the developing sleeve 6. It is not necessary to provide a new space in the developing container 14 for installing the spring member 19.

  That is, the spring member 19 pressurizes the developing sleeve 6 with the shaft portion 6c having a small diameter, thereby reducing the space necessary for providing the spring member 19 and further reducing the size of the developing device 4. Is possible. As shown in FIG. 5, the bearing member 18 a can slide along a guide member 18 b provided in the developing container 14.

  FIG. 7 is a view of one end portion (driving side end portion) of the developing sleeve 6 as viewed in the H direction of FIG. The bearing member 18a has a guide groove a that forms a concave portion, and the concave portion is fitted into the convex portion b of the guide member 18b provided in the developing container 14. With this configuration, the bearing member 18a can move in the direction of arrow A in FIG. 5 along the guide member 18b. That is, the bearing member 18a can be brought into contact with the developer regulating portion 16 by displacing the developing sleeve 6 in the arrow A direction.

  The developing sleeve 6 can slide only in the direction of arrow A in FIG. The displacement direction of the developing sleeve 6 is also a pressing direction A by the spring member 19. The pressing direction A is a direction connecting the center of the sleeve and the developer restricting portion 16, and the angle θ (see FIG. 8) formed by the drum pressing direction B described above is 90 degrees. The other end (non-driving side end) of the developing sleeve 6 is also supported in the same configuration.

  In this embodiment, the developing sleeve 6 is pressed against the developer restricting portion 16 that does not move with respect to the developing container 14 by the pressure of the spring members 19 disposed at both ends of the developing sleeve 6. By adopting this configuration, it is possible to stably maintain the regulation pressure that regulates the toner carried on the developing sleeve 6 and the regulation position of the toner. That is, it is possible to keep the amount of the toner 5 carried on the developing sleeve 6 and the layer thickness of the toner layer formed on the developing sleeve 6 constant while making the developing device smaller and thinner.

  That is, conventionally, as shown in FIGS. 27 and 28, a space S1 for bending the regulating blade 23 and a space S2 for providing a spring 29 for pressing the developer regulating member 28 against the developer carrier 24 are required. . As a result, it is difficult to reduce the size of the developing containers 26 and 22.

  On the other hand, in this embodiment, as shown in FIG. 8, the developer restricting portion 16 is integrated with the developing container 14, and a space is not provided between the developer restricting portion 16 and the developing container 14. Thereby, it is easy to reduce the size of the developing container 14.

  Further, in the conventional regulation blade 23 (see FIG. 27), the regulation position 25 that is a contact portion with the developer carrier 24 is separated from the developing container 22. That is, a space for deforming the regulating blade 23 is provided by disposing the contact portion of the regulating blade 23 that contacts the developer carrier 24 and the developing container 22 with a space therebetween. For this reason, there is a possibility that the restricting position 25 moves somewhat due to the deformation of the restricting blade 23.

  On the other hand, in this embodiment shown in FIG. 8, the developer regulating portion 16 and the developing container 14 are integrated. Therefore, even if the developer regulating portion 16 receives the pressure of the spring member 19 via the developing sleeve 6, the contact portion (developer regulating position) of the developer regulating portion 16 with respect to the developing sleeve 6 is against the developing container 14. There is no movement.

  In other words, in this embodiment, the developer regulating portion 16 and the developing container 14 are not arranged with a space therebetween. There is no space allowing deformation of the developer restricting portion 16 relative to the developing container 14 on the downstream side in the pressurizing direction A from the contact portion between the developer restricting portion 16 and the developing sleeve 6. Therefore, even if the developer regulating member 16 is pressed against the spring member 19, the position of the contact portion of the developer regulating portion 16 with respect to the developing sleeve 6 is fixed with respect to the developing container 14.

  Thereby, the developer regulating unit 16 can stably regulate the amount of developer on the developing sleeve 6.

  It is also possible to increase the developer regulating force by processing the developer regulating unit 16 such as roughing. When the amount of toner carried on the developing sleeve 6 is large and the toner is transferred to the blank area of the recording medium, so-called fogging occurs, the developer regulating portion 16 is subjected to a roughing process, whereby the developing sleeve 6 is treated. It is preferable to reduce the amount of toner carried.

  In order to roughen the developer regulating portion 16, the surface of the molding die for molding the developer regulating portion 16 may be blasted at random to create irregularities.

For example, when the surface roughness of the developer regulating portion 16 is set to Ra = 1.2 μm by the roughening process, the amount of toner carried on the developing sleeve 6 after passing through the developer regulating portion 16 is 12 g / m. ² . This is the weight of the toner carried per unit area of the developing sleeve 6. It becomes a smaller value than the case where the developer restricting portion 16 is not roughened and molded with a substantially smooth surface shape.

  In this embodiment, the sleeve pressing direction A in which the developing sleeve 6 is pressed against the developer regulating portion 16 by the spring member 19 is the direction connecting the sleeve center and the developer regulating portion 16. However, the developing sleeve 6 is not limited to this as long as it is in a direction in which the developer regulating portion 16 is pressurized. Further, in this embodiment, as shown in FIG. 5, the drum pressing direction B in which the photosensitive drum 1 presses the developing sleeve 6 and the sleeve pressing direction in which the developing sleeve 6 is pressed against the developer regulating portion 16 by the spring member 19. Although the angle θ formed by A is 90 degrees, it is not limited to this. It is sufficient that the developing sleeve 6 and the developer regulating portion 16 are not separated by the force with which the photosensitive drum 1 presses the developing sleeve 6.

  This is a case where Equation 1 shown below holds.

F1 + F2 × cos θ> 0 (1)
Here, as shown in FIG. 8, F <b> 1 is a force by which the spring member 19 presses the developing sleeve 6 toward the developer regulating portion 16. F2 is a force by which the photosensitive drum 1 presses the developing sleeve 6. θ is an angle formed by the direction in which F1 acts and the direction in which F2 acts on a plane orthogonal to the axis of the developing sleeve 6 (FIG. 8).

  In the left side of Equation 1, F2 × cos θ is a component force of F2 acting in the pressing direction A of the spring member 19. This component force has a positive value when θ is smaller than 90 degrees, and takes a negative value when θ is larger than 90 degrees.

  When Formula 1 is satisfied, the force with which the spring member 19 presses the developing sleeve 1 against the developer regulating portion 16 becomes larger than the force with which the photosensitive drum 1 tries to separate the developing sleeve 6 from the developer regulating portion 16.

  In this embodiment, an aluminum sleeve is used as the developer carrying member, but this is not a limitation. For example, a rubber roller may be used for the developer carrying member and a non-magnetic toner may be used for the developer.

[Example 2]
Example 2 will be described with reference to FIG. In the first embodiment, the developer regulating portion 16 is a part of the developing container 14 and is formed integrally with the developing container 14. However, in the present embodiment, the sheet member 40 is attached to the developing container 14 side. This is the developer regulating section.

The sheet member 40 is made of urethane rubber having a thickness of 0.5 mm and a surface roughness Ra = 0.1 μm. The sheet member 40 has a JIS-A hardness of 65 ° and a Young's modulus E = 3 × 10 ⁶ Pa. One surface of the sheet member 40 was attached to the ceiling plate 14g of the developing container 14 using a double-sided tape having a thickness of 0.1 mm. The other surface is in contact with the developing sleeve 6 and regulates the toner carried on the developing sleeve 6. The sheet member 40 that is a developer restricting portion is a member that is sandwiched between the developing plate 6 and the ceiling plate 14 g that is a fixing portion of the developing container 14 at a contact portion that contacts the developing sleeve 6. The configuration other than the sheet member 40 is the same as that of the developing device 4 of the first embodiment.

  Since the surface of the sheet member 40 opposite to the surface in contact with the developing sleeve 6 is supported by the ceiling plate 14g, the sheet member 40 moves relative to the developing container 14 even when pressed from the developing sleeve 6. There is no. That is, in the pressure direction of the spring member 19, the fixing portion (ceiling plate 14 g) of the developing container 14 is spaced from the sheet member 40 on the downstream side (back side of the contact portion) of the contact portion between the sheet member 40 and the developing sleeve 6. Arranged without leaving a gap. Even when the sheet member 40 is subjected to the pressing force of the spring member 19 due to contact with the developing sleeve 6, there is no space that allows the sheet member 40 to move downstream of the sheet member 40 in the pressing direction. . That is, the position of the contact portion between the sheet member 40 and the developing sleeve 6 is fixed without moving with respect to the developing container 14. Accordingly, the sheet member 40 can stably form a toner layer having a certain thickness on the developing sleeve 6.

  Urethane rubber has higher wear resistance than HI-PS, so that the durability of the process cartridge is improved. In this embodiment, urethane rubber is used as the material of the sheet member, but the material is not limited to this as long as another material is used for the restricting portion in order to improve wear resistance.

  Further, as the sheet member 40, a material that is different from the developing container 14 in chargeability with respect to the toner can be used.

  For example, if the charge amount of the toner becomes too high, the toner may be agglomerated by static electricity at the developer regulating portion, and the toner layer may not be regulated uniformly. When such a problem occurs, polyphenylene sulfide resin (PPS) can be used as the sheet member 40. PPS is a material having a negative charge series (charged column) compared to HI-PS, which is the material of the developing container 14. That is, PPS is a member that is negatively charged when rubbed with HI-PS. That is, PPS is less likely to charge toner 5 to negative polarity (normal polarity) than HI-PS.

  Actually, when a PPS having a thickness of 100 μm and a surface roughness Ra = 0.1 μm is adopted as the sheet member 40, charging of the toner carried on the developing sleeve 6 after passing between the sheet member 40 and the developing sleeve 6 is performed. The amount (charge amount per unit weight) was 7 μC / g. This is a value lower than the charge amount of the toner in Example 1.

  The use of a material that is not limited to PPS and is less likely to charge toner than the developing container 14 is used for the developer regulating portion, so that the occurrence of electrostatic aggregation can be suppressed and the occurrence of image defects can be suppressed. This is not limited to the case where the sheet member 40 is used for the developer restricting portion, and the same applies when the developer restricting portion is formed as a part of the developing container.

  Conversely, in order to reliably charge the toner, a material that charges the toner more easily than the developing container 14 is selected as the sheet member 40. Such a configuration will be described in detail later in the third embodiment.

Example 3
Another embodiment of the present invention will be described with reference to the drawings. First, the developing device 100 used in this embodiment will be described with reference to FIG.

  In this embodiment, the developing device 100 is integrated with the photosensitive drum 120 to form a process cartridge B1. The process cartridge B1 is detachably mounted on the main body of the image forming apparatus.

  The developing device 100 agitates the toner accommodated in the developing container 110 by a rotating agitating member 109 and conveys the toner to the vicinity of the developing roller 101 which is a developer carrying member. The stirring member 109 includes a rotation support member 108 that is rotatably supported by the developing container 110, and a flexible sheet 107 that is attached to the rotation support member 108. The flexible sheet 107 has a length sufficient to contact the bottom surface so that toner does not stay on the bottom surface of the developing container 110.

  The toner conveyed to the vicinity of the developing roller 101 by the stirring member 109 is carried on the developing roller 101. In this embodiment, the developing roller 101 is a developing sleeve made of an aluminum tube, and has a magnet roller inside. The toner is a magnetic toner having magnetism, and is attracted to the developing roller 101 by the magnetic force generated by the magnet roller.

  The amount of toner carried on the developing roller 101 is regulated to be constant in the developer regulating region 111, and a toner layer having a predetermined layer thickness is formed on the developing roller 101. In this embodiment, the developer restriction region 111 is configured by a sheet seat surface 104 formed in the developing container 110 and a sheet member 103 attached to the sheet seat surface 104.

  The seat seat surface 104 is a fixing portion that fixes the seat member 103. The sheet member 103 is disposed at a position sandwiched between the developing roller 101 and the sheet seating surface 104, and is attached to the sheet seating surface 104 by a double-sided tape 106. The sheet member 103 is a member that actually contacts the developing roller 101 and forms a developer regulating portion.

  When the sheet member 103 in the developer restricting region 111 comes into contact with the developing roller 101, the amount of toner carried on the developing roller 101 is regulated to a constant level, and a toner layer having a predetermined layer thickness is formed on the developing roller 301. It is formed. In addition, the toner is given a desired charge in the regulation nip portion 102 where the developing roller 101 and the sheet member 103 abut.

  The charged toner on the developing roller 101 develops the electrostatic latent image formed on the photosensitive drum 120 at a facing portion 121 where the developing roller 101 and the photosensitive drum 120 face each other. In the developing process of this embodiment, a superimposed bias obtained by superimposing an AC voltage on a DC voltage is used for the developing roller 101. The developing roller 101 and the photosensitive drum 120 are not in contact with each other at the facing portion 121, and the charged toner is caused to fly by the electric field formed between the developing roller 101 and the photosensitive drum 120.

  Here, the developing roller 101 is rotatably supported at its shaft portion 101 b by a bearing member (support portion) 112. The bearing member 112 is movably provided, and the distance between the developing roller 101 and the developer regulating area 111 is variable. A spring member (elastic member) 113 as an urging member (pressure member) is attached to the bearing member 112 and presses the developing roller 101 toward the developer regulating region 111.

  With this configuration, also in the process cartridge B1 of the present embodiment, the regulation pressure and the regulation position for regulating the toner of the developing roller 101 are accurately maintained.

  The material of the developing container 110 is HI-PS using a styrene resin from the viewpoint of impact resistance, material cost, workability, and the like. The toner used was granulated with the same styrenic resin as the developing container 110 in order to prevent electrostatic aggregation in the developing container due to unnecessary charged charges when stored in the developing container. This is to prevent the toner from aggregating inside the developing container 110 and reducing the toner transportability.

  That is, in this embodiment, in order to prevent the toner from electrostatically aggregating in the developer storage chamber 110a of the developing container 110, the developing container 110 and a toner material that does not easily charge the toner are selected. However, on the other hand, in order to develop a latent image using a developer at the time of image formation, it is necessary to charge the toner carried on the developing roller by the developer regulating unit.

  In particular, in an environment where the temperature and humidity are high and it is difficult to charge the toner, it is necessary to sufficiently charge the toner by the developer regulating unit. This is because when the charge amount of the toner is reduced, it is difficult to be held by the developing roller, and the toner may scatter from the developing roller and may contaminate the inside of the image forming apparatus.

  Therefore, in this embodiment, a material having higher chargeability with respect to the toner than the developer accommodating chamber 110a is used for the sheet member 103 provided in the developer regulating region 111. Accordingly, even when the temperature and humidity environment changes, electrostatic charging of the toner is suppressed, and an appropriate charged charge is given to the toner carried on the developing roller 101 so that the toner does not scatter from the developing roller 101. It is characterized by.

  Hereinafter, since the effect in the present embodiment was verified by experiment, it will be described below.

(Experimental conditions)
As experimental conditions, the developing roller 101 has a diameter of 12 mm, and the photosensitive drum 120 has a diameter of 20 mm. The spring member 113 was adjusted so that the contact pressure at which the developing roller 101 abuts against the developer restricting region 111 in the restricting nip 102 was 30 [g / cm] in terms of linear pressure. Here, the method for measuring the linear pressure is as follows.

  First, three SUS sheets are inserted into the restriction nip portion 102 between the developing roller 101 and the developer restriction area 111 in the absence of toner, and the spring pressure F [gf] when the middle sheet is pulled out is measured. Here, the thickness of the SUS sheet is 50 [μm] and the width is w [cm]. Then, the friction coefficient μ between the SUS sheets is measured. From these numerical values, the linear pressure P is obtained by a calculation formula of P = μF / w.

  As a condition for supporting the toner on the developing roller 101, 100 g of toner was filled in the developing container 110, and the developing roller was rotated for 1 minute at a rotation speed of 30 rpm (rotation speed per minute).

  Thereafter, the charge amount per unit mass of the toner carried on the developing roller 101 was measured using a coulomb meter and an electronic balance. In addition, in order to check the toner scattered in the apparatus, an OHP sheet 401 was attached to the lower part of the developing container 110 as shown in FIG. 11, and the presence or absence of toner falling from the developing roller 101 was checked.

(Measurement of comparative example)
First, an experiment was performed using a process cartridge B2 shown in FIG. 12 as a comparative example for the present embodiment. In the process cartridge B2, the developer regulating portion 304 is formed of the same HI-PS material as that of the developing container 307. Other configurations are the same as those of the process cartridge B1 in this embodiment.

Table 1 shows the result of the experiment with the process cartridge B2. As shown in Table 1, the charge amount and the toner drop were confirmed under three typical temperature and humidity conditions. Each condition is: Condition 1: Temperature 15 ° C, Humidity 10%
Condition 2: Temperature 23 ° C, Humidity 60%
Condition 3: Temperature 32 ° C, Humidity 80%
It was. The unit of charge amount of toner is [μC / g]. Further, the criteria for determining whether or not the toner has dropped is when “◯” indicates that the toner has not dropped and “×” indicates that the toner has dropped.

  As a result of experiments, it was found that the amount of charged charge varies depending on the temperature and humidity conditions. In addition, whether or not the toner is dropped differs depending on the temperature and humidity conditions, and there is a threshold value at which the toner falls while the charged charge amount of the toner changes from −5 [μC / g] to −2 [μC / g]. I understood that. As is apparent from Table 1, it can be seen that there is a tendency to the triboelectric charge amount of the toner on the developing roller and the toner dropping.

  That is, in the process cartridge B2 of the comparative example, the toner is sufficiently charged under the condition 1 (low temperature and low humidity: temperature 15 ° C., humidity 10%) and under the condition 2 (room temperature and normal humidity: temperature 23 ° C., humidity 60%). However, the toner does not fall from the developing roller. On the other hand, in condition 3 (high temperature and high humidity: temperature 32 ° C., humidity 80%), the charge amount of the toner tends to decrease, and the toner sometimes falls from the developing roller.

(Measurement in this example)
Therefore, based on the above results, in the process cartridge B1 of the present embodiment, as described above, the sheet member 103 that is the developer regulating portion is formed of a material that is more easily charged with a negative polarity (normal polarity) than the developing container 110. . That is, the sheet member 103 is made of a material that is on the positive polarity side of the developing container 110 in the charging series, and has a property of being charged to a positive polarity when rubbed with the HI-PS constituting the developing container 110.

  The sheet member 103 is charged with a positive polarity, so that the toner carried on the developing roller 101 is charged with a negative polarity.

  Actually, as the sheet member 103, a polycarbonate (PC) sheet, a polyethylene terephthalate (PET) sheet, and a metal sheet (in this example, stainless steel (SUS) is used) are used. Each of the sheet members 103 was sandwiched between the developing roller 101 and the sheet seating surface 104, and an experiment was performed.

  In the process cartridge B1 in this embodiment, Table 2 shows the results of experiments on the sheet member 103 employing the above-described materials. Comparing Table 1 and Table 2, it is possible to increase the amount of toner triboelectric charge compared to the comparative example by installing the sheet member 103 that easily charges the toner in the developer regulating portion. I understand. Furthermore, it was confirmed that the toner does not fall even under high temperature and high humidity with the improvement of the triboelectric charge amount.

  As described above, by providing a sheet member that can easily charge the toner to the negative polarity (the normal polarity of the toner at the time of image formation) from the developing container in the developer regulating portion, an appropriate charge is applied to the toner. The toner scattering can be further suppressed.

(Modification)
Next, two modified examples of this embodiment are shown in FIGS. 13 (a) and 13 (b). As shown in FIG. 13A, this modification is characterized in that a developer regulating member 114 serving as a developer regulating portion is fitted and fixed to a seating surface portion (fixed portion) 110b of the developing container 110. Further, as shown in FIG. 13B, the developer restricting portion 115 is fixed to the fixing portion 110b. The developer regulating member 114 is disposed at a position sandwiched between the developing roller 101 and the seat surface portion 110b. That is, the developer regulating member 114 is supported by the seat surface portion 110b on the side opposite to the contact portion with the developing roller 101. The developer regulating portion 115 is fixed by inserting a fixed portion 115b provided on the opposite side of the contact portion with the developing roller 101 into the seating surface portion 110b.

  The developer regulating members 114 and 115 are formed of a material that is on the positive side in the charging series (a material that is easily charged positively) than the developing container 110, and charge the toner to a negative polarity (the normal polarity of the toner at the time of image formation). It is a member that is easy to let

  The developer restricting members 114 and 115 provided in the developer restricting portion of this modification have rigidity, and the position for restricting the developer is different from that of the flexible sheet member 103 (see FIG. 10). There is a stable feature.

  The configuration described above is an example, and the present invention is not limited to this. For example, in this embodiment, the sheet member 103 is made of a material that easily charges the toner to a negative polarity. This is because the image forming system used in this embodiment is configured to form an image by charging the toner to a negative polarity. In an image forming system using a toner charged with a positive polarity for image formation, a similar effect can be obtained by selecting a sheet member that is more easily charged with a positive polarity than the developing container.

  In order to reliably charge the toner to the normal polarity by the developer restricting portion, it is only necessary that the developer restricting portion be easily charged to a polarity opposite to the normal polarity of the toner from the developer storage chamber of the developer container. That is, in the charging series, the developer restricting portion may be formed of a material that is on the side opposite to the normal polarity of the toner from the developer accommodating chamber.

Example 4
In Example 3, a sheet member or the like that easily gives the toner a triboelectric charge amount is used for the developer regulating unit, so that the toner is charged only by contact between the frame of the developing container and the developing roller. The toner can be charged efficiently.

  On the other hand, in this embodiment, a configuration in which the developer restricting portion is integrally molded with the developing container by using two-color molding or insert molding instead of fixing a member of another material to the developing container will be described. Also in this embodiment, it is possible to provide a developing device and a process cartridge that appropriately charge the toner in the developer regulating portion.

  First, the configuration used in this embodiment will be described with reference to FIGS. 14, 15, and 16. FIG. Note that a description of the same parts as those in the third embodiment will be omitted.

  FIG. 14 is an explanatory view for explaining a molding means called insert molding. As shown in FIG. 14A, an insert member 603 serving as a developer regulating portion is installed in a mold such as a mold 601 and a mold 602. In the case of the present embodiment, as an example, a SUS plate that is a metal sheet was installed as the insert member 603.

  The mold 601 is provided with a casting port 604 for casting resin or the like into the mold. The casting port 604 is not limited to being provided at the location shown in FIG. 14, and an optimized location and number can be selected depending on the viscosity of the resin to be cast and the size of the member to be molded.

  As shown in FIG. 14B, the insert member 603 is installed, the mold 601 and the mold 602 are heated to such a degree that the resin to be cast and poured sufficiently flows into the mold, and the resin is injected from the casting port 604. To do. When the resin is sufficiently cast as shown in FIG. 14C, the mold 601 and the mold 602 are separated again while cooling the mold. At that time, the insert-molded resin member is separated from the mold, and the developer container and the developer regulating member are obtained in a form close to the product (see FIG. 14D). Thereafter, an excess portion 605 such as the remainder of the casting port is cut to obtain a final molded part. By using insert molding in this way, the developer regulating portion formed of the insert member 603 is molded integrally with the frame 607 of the developer container.

  On the other hand, as shown in FIG. 15, the developer regulating portion can be molded using a molding means called two-color molding or double molding.

  As shown in FIG. 15A, the molds 701 and 702 are combined, and the resin is cast from the casting port 710 as shown in FIG. 15B. At this time, the first-stage molded member formed by the mold 701 and the mold 702 is obtained in a state where a portion (a portion serving as a developer regulating portion) 703 desired to be made of different materials is removed. Thereafter, the mold 702 is removed as shown in FIG. 15 (c), and the mold 704 capable of casting resin only in a portion to be the developer regulating portion is formed as shown in FIG. 15 (d). Combine with. Thereafter, as shown in FIG. 15 (e), a resin of a material different from the resin cast from the casting port 710 is cast from the casting port 709.

  The molded member is a member formed by molding two types of resin 705 forming a developer storage chamber of the developer container and resin 706 serving as a developer regulating portion (see FIG. 15F).

  The obtained molded member can be cut into excess portions 707 and 708 remaining inside the casting port to obtain a product shape. As described above, the developer regulating portion (resin 706 in FIG. 15) and the developer container (resin 705 in FIG. 15) can be integrally formed by two-color molding.

  In order to make the description of the mold 704 used in the present description easy to understand, a casting port 709 is provided at a position where the contact surface of the developer regulating portion that contacts the developing roller is formed. However, since the contact surface that contacts the developing roller is an important part for uniformly coating the toner layer of the developing roller, high surface accuracy is required. For this reason, it is desirable that the casting port 709 is installed away from the contact surface of the developer regulating portion.

  Hereinafter, this embodiment will be described by taking as an example the case where the developer container and the developer regulating portion are molded using the two-color molding shown in FIG.

  In this embodiment, a resin made of PET (polyethylene terephthalate) was selected as the resin 706 serving as the developer regulating portion. Further, HI-PS (high impact polystyrene) was selected as the resin 705 that forms the main part of the developing container (the part that becomes the developer storage chamber). That is, in the developer container, a material that easily charges the toner to the negative polarity (normal polarity) is used for the developer regulating portion, which is more positively charged than the developer storage chamber.

  Table 3 shows the charge amount of the toner and the presence / absence of toner dropping in this example. The experimental method is the same as that used in Example 3 described above.

  For reference, in addition to the present embodiment, the results of an experiment with a configuration using a sheet member made of PET for the developer regulating portion (the configuration shown in Example 3, see FIG. 5) are listed.

  Also in this example, the same results as in the configuration of Example 3 (configuration in which a sheet member made of PET is provided in the developer regulating portion) can be obtained. That is, even when the developer restricting portion is formed by two-color molding, a sufficient effect can be obtained to appropriately frictionally charge the toner.

  Furthermore, in this embodiment, the developer restricting portion is fixed in a form compatible with the frame of the developing container, so that the developer restricting portion can be stably installed.

Example 5
In the third and fourth embodiments, the effect and means by changing the material of the developer regulating portion to a member that easily charges the toner has been described.

  In the present embodiment, the configurations of the third and fourth embodiments are further developed to suppress the toner from being overcharged at the end portion of the image forming region and to reliably suppress the image defect.

  When a large amount of printing is performed in a low temperature and low humidity environment in a short time, there is a possibility that the toner adheres to the edge margin of the recording paper (recording medium). This is because the toner positioned at the end in the longitudinal direction of the developing roller is difficult to be used for image formation and continues to be charged by the developer regulating portion. In other words, if the toner is excessively charged at the end of the developing roller, the toner may be transferred from the developing roller to a non-image forming area (an area where no toner image is originally formed) of the photosensitive drum, and finally adhere to the recording paper. Be sexual.

  In particular, a gap between the developing container and the developing roller is filled by contacting a seal member at the end of the developing roller so that the developer does not leak outside from the developing container. Outside the position where the seal member contacts the developing roller, the toner is hardly used for image formation. That is, when the toner is carried on the developing roller outside the seal member, it is carried and tends to be excessively charged.

  Therefore, in this embodiment, in the developer regulating portion, the region that contacts the end portion of the developing roller is formed of a material that is less likely to charge the toner than the region that contacts the central portion of the developing roller. As a result, the charge applied to the toner by the developer regulating unit is appropriately controlled to prevent the toner carried on the end of the developing roller from being overcharged.

  Hereinafter, the configuration of the developer regulating portion 804 in this embodiment will be described with reference to FIG. In this embodiment, in the longitudinal direction of the developing roller 101, the central portion 804a of the developer restricting portion 804 is formed of PET, and the end portions 804b and 804c of the developer restricting portion 804 are made of the same HI-PS as the developer containing chamber. Formed.

  In the developing roller 101, an area indicated by reference numeral 803, which is located at the center in the longitudinal direction, is a toner supply area to which toner is supplied from the developer storage chamber.

  A seal member (not shown) is in contact with the developing roller 101 at both ends of the toner supply region 803. Further, there are developing roller end regions 801 and 802 outside the position where the seal member contacts.

  In the end regions 801 and 802 located outside the toner supply region 803, toner is not supplied from the developing container and hardly carries toner. However, once toner is carried on the end region 801 and the end region 802, the toner may be excessively charged.

  Therefore, as shown in FIG. 16, the toner supply region 803 is brought into contact with the central portion 804a of the developer restricting portion formed of PET, while the end portion regions 801 and 802 are made of the developer restricting portion formed of HI-PS. The end portions 804b and 804c of each other were brought into contact with each other. HI-PS is a member on the negative polarity side of PET in the charging series. In other words, HI-PS is less likely to charge the toner to a negative polarity than PET, and the toner can be prevented from being excessively charged at the end of the developing roller. This suppresses the phenomenon that the overcharged toner adheres to the end of the recording paper.

  Since the effect of this example was confirmed by the test, the result will be described below. In the test, a process cartridge employing the developer regulating unit 804 described above was mounted on an image forming apparatus, and images were continuously printed on recording paper by the image forming apparatus. The printed recording paper was confirmed, and it was determined whether toner adhered to the edge of the recording paper.

  As operating conditions of the image forming apparatus, a process speed for rotating the photosensitive drum was set to 200 mm / sec, and a speed for printing an image on a recording sheet was set to 30 sheets per minute. A4 size paper was used as the recording paper, and a 600 dpi resolution image in which horizontal lines of 4 dots width were arranged at a pitch of 100 dots was used as an image to be printed. The ratio of the area where the image is printed on the recording paper, that is, the printing rate is 4%.

  Table 4 shows whether or not toner adheres to the edge of the recording paper for each number of recording papers printed continuously. A circle indicates that no toner has adhered to the recording paper, and a circle indicates that the toner has adhered to the recording paper.

  As a comparative example with respect to the present embodiment, as shown in FIG. 17, the test was performed under the same conditions using a process cartridge in which the entire region of the developer regulating portion 904 was formed of PET. Table 4 shows the test results.

  As can be seen from Table 4, in the comparative example in which all of the developer regulating portion 904 (see FIG. 17) is made of PET, when 1600 or more recording sheets are continuously printed, toner adheres to the end of the recording sheet. (Metastasis) was observed. On the other hand, in this embodiment (see FIG. 16), it was possible to suppress the toner from adhering to the recording paper over the printing of 1800 sheets.

  Table 5 shows the results of measuring the charge amount of the toner carried on the central portion and the end portion of the developing roller before the test and at the time of printing 1200 sheets of recording paper.

  As shown in Table 5, in the configuration shown in the comparative example, it is understood that the charge amount of the toner carried on the end portion of the developing roller is very high by printing 1200 sheets of recording paper. On the other hand, in the present embodiment, there was almost no change in the charge amount of the toner carried on the end of the developing roller before the test and after printing 1200 sheets of recording paper. It was also confirmed that the same amount of charged charge as that at the center of the developing roller was obtained.

  The configuration described in this embodiment is only an example. Although the description has been made using PET and HI-PS as a combination of materials of the developer regulating portion, this is not restrictive. For example, in a developer container in which the developer accommodating chamber is formed of HI-PS, when the central portion of the developer restricting portion is formed by PC, the end of the developer restricting portion is less charged with respect to toner than PC. Even if formed by PET, it is effective.

  In other words, the end of the developer restricting portion may be formed of a material that is on the normal polarity side of the toner relative to the central portion of the developer restricting portion in the charging series.

  Further, the place where the material of the developer restricting portion is switched may be any place as long as it does not affect the image. In this embodiment, the positions of the central portion 804a and the end portion 804b of the developer storage chamber are determined on the basis of the case where the A4 size is adopted for the recording paper. However, the present invention is not limited to this.

Example 6
Another embodiment will be described below.

  Since the developer carrier is configured to be displaceable with respect to the developer container in the first embodiment, the developer carrier oscillates with the rotation, and the axis of the developer carrier is oriented in the design direction. The possibility of tilting with respect to When the developer carrying member swings in this way, the end portion in the longitudinal direction of the developer carrying member moves from the position where the developer regulating unit is provided. As a result, there is a possibility that the developer cannot be stably regulated at the end of the developer carrying member. As a result, problems such as fogging and image density unevenness may occur at both ends of the image.

  Therefore, in the configuration in which the developer carrying body is displaceable with respect to the developer container and the developer carrying body is pressurized by the developer regulating portion to regulate the developer on the developer carrying body. It is important to suppress the rocking of the. The present embodiment is characterized in that a movement restricting portion 30 that restricts the peristaltic movement of the developer carrying member is provided. In the following description, the same components as those in the first embodiment will be described using the same reference numerals. Detailed description of the same configuration as that of the first embodiment is omitted.

  18 is a cross-sectional view taken along line (7)-(7) in FIG. 3 (vertical front view), and FIG. 19 is a cross-sectional view taken along line (8)-(8) in FIG. It is. 20A is a partially cutaway perspective view of the assembly of the developing sleeve 6 and the magnet roller 15, and FIG. 20B is a partially enlarged perspective view of FIG. (A) also includes a developer restricting portion 16 to be described later and left and right movement restricting portions 30L and 30R for restricting both end portions of the developing sleeve 6 (one end side and the other end side in the axial direction of the developing sleeve 6). doing. The magnet roller 15 has an outer diameter that is slightly smaller than the inner diameter of the sleeve portion 6a. The left and right shaft end portions 15aL and 15aR of the shaft portion 15a of the magnet roller 15 are inserted into the left and right shaft portions 6cL and 6cR of the developing sleeve 6, respectively. The outer diameters of the shaft end portions 15aL and 15aR are substantially the same as the inner diameters of the shaft portions 6cL and 6cR, and the shaft portions 6cL and 6cR are rotatably supported by the shaft end portions 15aL and 15aR. That is, the developing sleeve 6 can rotate coaxially around the outer circumference of the magnet roller 15.

  The left shaft end portion 15aL of the shaft portion 15a protrudes outward from the left shaft portion 6cL as shown in FIG. A key 15bL is provided at the end of the protruding shaft end 15aL. The key 15bL of the shaft end portion 15aL protruding outward from the left shaft portion 6cL is fitted and engaged with a vertical key groove 14hL provided on the inner surface side of the left side plate 14cL of the developing container 14. Further, the right shaft 6cR protrudes outwardly from the right plate 14cR through a vertical hole 14j (FIG. 18) provided in the right plate 14cR of the developing container 14 in the vertical direction. A drive gear 17 is disposed concentrically and integrally with the protruding shaft portion 6cR.

  FIG. 21 is a perspective view of the right bearing mechanism 18R. The key 15bL of the shaft end portion 15aL protruding outward from the left shaft portion 6cL is fitted and engaged with a vertical key groove 14hL provided on the inner surface side of the left side plate 14cL of the developing container 14. The right shaft portion 6cR protrudes outwardly from the vertical hole 14j provided in the right plate 14cR of the developing container 14 to the outside of the right plate 14cR. Accordingly, the developing sleeve 6 including the magnet roller 15 is allowed to move in the vertical direction with the magnet roller 15 being rotated. The developing sleeve 6 can rotate around the magnet roller 15 that is prevented from rotating by transmitting a rotational force to the drive gear 17.

  As in the first embodiment, in this embodiment, the left and right ends of the developing sleeve 6 having the longitudinal axis as the longitudinal direction can be slid in the vertical direction along the guide members 18bL and 18bR, respectively, and the left and right movable bearing members 18aL and 18aR. It is supported by. The developing sleeve 6 can be displaced in the direction A in which the developer sleeve 6 is pressurized by pushing and biasing the left and right movable bearing members 18aL and 18aR by the spring members 19L and 19R.

  For this reason, a gap (backlash) is required to some extent between the fitting portions of the bearing members 18aL and 18aR and the guide members 18bL and 18bR on the developing container side. In designing, although consideration is given to minimizing the backlash as much as possible, the backlash may become relatively large due to variations in the dimensions of parts.

  Due to this play, as the developing sleeve 6 rotates, as shown in the schematic diagram of FIG. 22, the direction of the arrow A in the X1 and X2 directions (the plane perpendicular to the axis of the developing sleeve 6 (FIG. 22)) May swing in the direction of crossing). When the developing sleeve 6 is swung, both ends in the longitudinal direction of the developing sleeve 6 are moved from the position where the developer restricting portion 16 is provided. As a result, the regulation of the toner 5 becomes unstable at both ends in the longitudinal direction of the developing sleeve 6 and the amount of toner 5 on the developing sleeve 6 is increased. As a result, problems such as fogging and density unevenness may occur at both ends of the image, leading to a decrease in image quality.

  Therefore, in the present invention, as shown in FIGS. 23, 18, 20, and 21, the movement restricting portions 30 </ b> L and 30 </ b> R for restricting the swing (movement) of both ends of the developing sleeve 6 are developed by the developing device 4. It was provided in the container 14. Thereby, even if there is a backlash in the fitting portion between the movable bearing members 18aL and 18aR and the guide member 18bL and 18bR on the developing container side, the swing of the developing sleeve 6 can be suppressed. As a result, the amount of toner 5 on the developing sleeve 6 is stabilized.

  In this embodiment, the movement restricting portions 30L and 30R are disposed outside the developer restricting portion 16 and within the developer non-supply area width W6e at both ends of the developing sleeve 6. As shown in FIG. 21, the movement restricting portions 30L and 30R are located on the downstream side of the developing sleeve 6 in the direction in which the spring members 19L and 19R press the developing sleeve 6 (arrow A direction), and the spring members 19L and 19R The developing sleeve 6 pressurized by 19R is pressed. FIG. 24 is a partial perspective view of the developer container 14 provided with the developer restricting portion 16 and the movement restricting portions 30L and 30R as seen from the inner surface side of the ceiling plate 14g of the developing container 14. Each of the movement restricting portions 30L and 30R has a developing sleeve receiving surface 30a for receiving the upper surface portions of both end portions of the developing sleeve 6. In this embodiment, the developing sleeve receiving surface 30a is an arc-shaped surface that matches the curvature of the developing sleeve 6 as shown in the schematic diagram of FIG. That is, the developing sleeve receiving surface 30 a is a curved surface portion along the peripheral surface of the developing sleeve 6.

  The developing sleeve 6 is pushed upward and biased by the left and right bearing mechanisms 18 </ b> L and 18 </ b> R (pressing direction A), so that the top surface of the sleeve abuts with a predetermined pressing force along the length of the developer regulating portion 16. Further, on the left and right outer sides in the longitudinal direction of the developer restricting portion 16, the upper surface portions on the left and right end portions of the developing sleeve 6 are fitted into the developing sleeve receiving surface 30a that is the arc-shaped surface of the left and right movement restricting portions 30L and 30R and pressed. To be accepted.

  In the present embodiment, as described above, the left and right movement restricting portions 30L and 30R having the arcuately shaped developing sleeve receiving surface 30a along the outer peripheral surface of the developing sleeve 6 are the upper surface portions on the left and right ends of the developing sleeve 6. Are received in a fitting manner. As a result, the developing sleeve 6 is hardly swung in the front-rear direction as shown in FIGS. 25B and 25C, that is, the developing sleeve 6 is restricted from swinging at both longitudinal ends, and the developing sleeve 6 is swung. Motion is reduced. That is, on the plane orthogonal to the axis of the developing sleeve 6, the developing sleeve 6 extends in a direction (arrow X 1 and X 2 directions shown in FIG. 22) that intersects the pressing direction of the pressure spring 19 (arrow A direction shown in FIG. 22). Can be prevented from moving.

  Since the movement restricting portions 30L and 30R rub against the surface of the carrying portion 6a of the developing sleeve 6 when the developing sleeve 6 rotates, it is preferable to use a smooth member so that the frictional force received at this time becomes small. Specifically, plastics such as polyacetal (POM), polyphenylene sulfide (PPS), and polytetrafluoroethylene (PTFE) are preferable.

  By disposing the movement restricting portions 30L and 30R outside the developer restricting portion 16, it is possible to suppress the swing of the developing sleeve 6 without affecting the amount of toner 5 on the developing sleeve 6. By disposing the developing sleeve 16 at both ends, the swinging of the developing sleeve 6 can be effectively suppressed.

  The movement restricting portions 30L and 30R can be molded integrally with the developing container 14, but a member of a material with better wear resistance may be molded in two colors or attached as a separate member. As a result, it is possible to cope with a long-life developing device.

Example 7
In the sixth embodiment, the shape of the developing sleeve receiving surface 30a of the movement restricting portions 30L and 30R is an arc shape that matches the curvature of the developing sleeve 6. In this configuration, the movement restricting portions 30L and 30R and the developing sleeve 6 are in contact at one point. Although the swing of the developing sleeve 6 can be suppressed, the axis of the developing sleeve 6 may be slightly inclined with respect to the direction in which the developer restricting portion 16 extends (longitudinal direction of the developer restricting portion 16).

  In the seventh embodiment, as shown in the schematic diagram of FIG. 26, the shape of the developing sleeve receiving surface 30a of the movement restricting portions 30L and 30R is V-shaped. In this configuration, on the plane orthogonal to the axis of the developing sleeve 6 (FIG. 26), the movement restricting portions 30L and 30R and the developing sleeve 6 are in contact at two different points (two locations) P and Q. In the rotation direction of the developing sleeve 6, the point P is a point on the downstream side with respect to the contact portion between the developer regulating portion 16 and the developing sleeve 6, and the point Q is a point on the upstream side. As a result, the swinging of the developing sleeve 6 can be more reliably suppressed. In other words, the positions of both end portions in the longitudinal direction of the developing sleeve 6 with respect to the developer regulating portion 16 can be determined more reliably. As a result, the amount of toner 5 on the developing sleeve 6 in the longitudinal direction is more stable, and a higher quality image without image unevenness in the longitudinal direction can be obtained.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 4 Developing apparatus 5 Toner 6 Developing sleeve 9 Recording medium 13 Process cartridge 14 Developer container 16 Developer control part 18a Bearing member 19 Spring member (elastic member)

Claims (14)

In a developing device for developing a latent image formed on an image carrier,
A developer carrier that is rotatably provided and carries the developer;
A developer container forming a developer storage chamber for storing the developer;
A developer regulating unit that regulates the amount of developer that is provided in the developer container and carried on the developer carrying member;
With
The developing device, wherein the developing container sandwiches a part of the developer restricting portion, and the developing container and the developer restricting portion are integrally formed.   The developing device according to claim 1, wherein the developer restricting portion is a metal sheet. In a process cartridge that can be attached to and detached from the main body of an image forming apparatus,
An image carrier on which a latent image is formed;
A developer carrier that is rotatably provided and carries a developer for developing the latent image;
A developer container forming a developer storage chamber for storing the developer;
A developer regulating unit that regulates the amount of developer that is provided in the developer container and carried on the developer carrying member;
A support part that supports the developer carrier and allows the developer carrier to move relative to the developer regulating part;
A pressure member for pressurizing the developer carrier toward the developer regulating portion;
With
The process container, wherein the developer container sandwiches a part of the developer restricting portion, and the developer container and the developer restricting portion are integrally formed.   The process cartridge according to claim 3, wherein the developer restricting portion is a metal sheet. A developing device manufacturing method for developing a latent image formed on an image carrier,
A developer carrier that is rotatably provided and carries the developer;
A developer container forming a developer storage chamber for storing the developer;
A developer regulating unit that regulates the amount of developer that is provided in the developer container and carried on the developer carrying member;
The developing device comprises
The developer container manufacturing method according to claim 1, wherein the developer container sandwiches a part of the developer restricting portion, and the developer container and the developer restricting portion are integrally formed.   The method for manufacturing a developing device according to claim 5, wherein the developer restricting portion is configured integrally with the developing container using insert molding.   The method for manufacturing a developing device according to claim 6, wherein the developer regulating portion is a metal sheet.   The method for manufacturing a developing device according to claim 5, wherein the development regulating member is configured integrally with the developing container using two-color molding.   The method of manufacturing a developing device according to claim 8, wherein the developer regulating portion is formed between the developing container and a mold after the developing container is formed. A process cartridge manufacturing method detachable from an apparatus main body of an image forming apparatus,
An image carrier on which a latent image is formed;
A developer carrier that is rotatably provided and carries a developer for developing the latent image;
A developer container forming a developer storage chamber for storing the developer;
A developer regulating unit that regulates the amount of developer that is provided in the developer container and carried on the developer carrying member;
A support part that supports the developer carrier and allows the developer carrier to move relative to the developer regulating part;
A pressure member for pressurizing the developer carrier toward the developer regulating portion;
The process cartridge comprises:
The process container manufacturing method, wherein the developer container sandwiches a part of the developer restricting portion, and the developer container and the developer restricting portion are integrally configured.   The method of manufacturing a process cartridge according to claim 10, wherein the developer restricting portion is configured integrally with the developing container using insert molding.   The method of manufacturing a process cartridge according to claim 11, wherein the developer regulating portion is a metal sheet.   11. The process cartridge manufacturing method according to claim 10, wherein the development regulating member is configured integrally with the developing container using two-color molding.   14. The method of manufacturing a process cartridge according to claim 13, wherein the developer restricting portion is formed between the developing container and a mold after the developing container is formed.

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