Developing apparatus and image forming apparatus

Abstract

To provide a layer-restricting member that is strong and less prone to errors during assembly. [Solution] A developing apparatus comprising: a developing container capable of containing a developer containing toner and a carrier; a developer holder disposed inside the developing container and rotating with the developer on its surface; and a layer thickness regulating member whose tip is positioned opposite the surface of the developer holder and which regulates the layer thickness of the developer held by the developer holder, wherein the layer thickness regulating member comprises a non-magnetic plate with both longitudinal ends fixedly supported, and a magnetic plate formed symmetrically with respect to the rotation direction of the developer holder and fitted to cover the tip of the non-magnetic plate that faces the developer holder.

Description

Technical Field

[0001] The present invention relates to a developing device and an image forming apparatus.

Background Art

[0002] There is known a developer regulating member including a regulating plate disposed along the longitudinal direction of a developing roller having a magnet roller and regulating the supply amount of a developer, and a holding plate attached to a side surface of the regulating plate and holding the developer. A bent piece is provided on the side surface of the regulating plate, and the bent piece is bent to sandwich a side end portion of the holding plate between the regulating plate and the bent piece is caulked, whereby the holding plate is fixed to the side surface of the regulating plate (Patent Document 1).

[0003] There is also known a developing device including a developing container that houses a developer containing a carrier and toner, a stirring and conveying member that stirs and conveys the developer in the developing container, a developer carrier that carries the developer supplied from the stirring and conveying member, and a regulating member that is disposed opposite to the developer carrier and regulates the layer thickness of the developer on the surface of the developer carrier. The regulating member includes a regulating main body made of a resin having higher strength than the developing container, and a metal foil disposed at a tip end portion of the regulating main body. The metal foil has a downstream surface portion fixed to a surface on the downstream side in the rotation direction of the developer carrier of the regulating main body, and a regulating surface portion formed by bending a tip end of the downstream surface portion upstream in the rotation direction of the developer carrier and disposed opposite to the developer carrier (Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention aims to provide a layer-restricting member that is strong and less prone to errors during assembly. [Means for solving the problem]

[0006] To solve the above problem, the developing apparatus according to claim 1 is A developing container capable of housing a developer containing toner and carrier, A developer holder is placed inside the developing container and rotates while holding the developer on its surface, A layer thickness regulating member, the tip of which is positioned opposite the surface of the developer holder, regulates the layer thickness of the developer held in the developer holder, the layer thickness regulating member comprising: a non-magnetic plate with both longitudinal ends fixedly supported; and a magnetic plate formed symmetrically with respect to the rotational direction of the developer holder and fitted so as to cover the tip of the non-magnetic plate that faces the developer holder, It is characterized by the following:

[0007] The invention described in claim 2 is a developing apparatus described in claim 1, The magnetic plate has a restricting portion positioned opposite the surface of the developer holder, and a mounting portion formed by bending the plate so as to intersect the restricting portion and attached to the non-magnetic plate. It is characterized by the following:

[0008] The invention described in claim 3 is a developing apparatus described in claim 2, The magnetic plate is fixed to the non-magnetic plate by a snap formed in the mounting portion fitting into a groove formed in the non-magnetic plate. It is characterized by the following:

[0009] The invention described in claim 4 is a developing apparatus described in claim 2, The regulating portion is convex toward the surface of the developer holder. The developing apparatus according to feature 2.

[0010] The invention according to claim 5 is in the developing device according to any one of claims 1 to 4 wherein the magnetic plate has a thickness exceeding at least 0.3 mm, which is characterized by the above.

[0011] To solve the above problems, the image forming apparatus according to claim 6 includes an image carrier for holding an electrostatic latent image, developing means for developing the electrostatic latent image on the image carrier, and is provided with wherein the developing device according to any one of claims 1 to 5 is used as the developing means, <000E069>which is characterized by the above.

Advantages of the Invention

[0012] According to the inventions of claims 1 and 6, it becomes possible to attach the layer thickness regulating member on either the upstream side or the downstream side in the rotational direction of the developer carrier.

[0013] <G000077>According to the invention of claim 2, the magnetic plate can be easily and accurately attached to the non-magnetic plate.

[0014] According to the invention of claim 3, the magnetic plate can be easily attached to the non-magnetic plate without using screws or adhesives, and the rigidity of the layer thickness regulating member can be increased.

[0015] [[ID=PDF]] According to the invention of claim 4, the layer thickness of the developer can be made thinner.

[0016] According to the invention of claim 5, the variation in the layer thickness of the developer can be reduced and the layer can be made thinner. According to the invention of claim 5, the variation in the layer thickness of the developer can be reduced and the layer can be made thinner.

Brief Description of the Drawings

[0017] [Figure 1] It is a cross-sectional schematic view showing an example of the schematic configuration of the image forming apparatus. <000E093> [Figure 2] It is a longitudinal cross-sectional schematic view showing the photoreceptor unit and the developing device. [Figure 3] It is a schematic longitudinal sectional view showing the configuration of the developing device. [Figure 4] It is a schematic cross-sectional view developed in the horizontal direction along line A-B-C for explaining the conveyance of the developer in the developing device. [Figure 5] It is a diagram for explaining the configuration of the layer thickness regulating member, where (a) is a front view and (b) is a longitudinal sectional view. [Figure 6] It is a diagram for explaining the configuration of the magnetic plate, where (a) is a front view and (b) is a longitudinal sectional view. [Figure 7] It is a diagram for explaining the attachment of the layer thickness regulating member to the developing roller. [Figure 8] It is an explanatory diagram showing the relationship between the gap between the tip of the layer thickness regulating member and the surface of the developing sleeve and the amount of developer adhered to the developing roller after layer thickness regulation according to the thickness of the magnetic plate. [Figure 9] It is a diagram for explaining the configuration of the layer thickness regulating member according to a modified example, where (a) is a front view and (b), is a longitudinal sectional view.

Embodiments for Carrying Out the Invention

[0018] Next, embodiments and specific examples will be given below while referring to the drawings to explain the present invention in more detail, but the present invention is not limited to these embodiments and specific examples. Also, in the description using the following drawings, it should be noted that the drawings are schematic and the ratios of each dimension are different from the actual ones, and illustrations other than the members necessary for the explanation are appropriately omitted for ease of understanding.

[0019] [[ID=三十二]] (1) Overall Configuration and Operation of the Image Forming Apparatus (1.1) Overall Configuration of the Image Forming Apparatus FIG. I is a schematic cross-sectional view showing an example of the schematic configuration of the image forming apparatus 1 according to the present embodiment, and FIG. 2 is a schematic longitudinal sectional view showing the photosensitive member unit 13 and the developing device 14. The image forming apparatus 1 comprises an image forming unit 10, a paper feeder 20 mounted below the image forming unit 10, a paper discharge unit 30 provided at one end of the image forming unit 10 for discharging printed paper, an operation display unit 40, and an image processing unit 50 that generates image information from print information transmitted from a host device.

[0020] The image forming unit 10 comprises a system control device 11, an exposure device 12, a photoreceptor unit 13, a developing device 14, a transfer device 15, paper transport devices 16a, 16b, 16c, and a fixing device 17, and forms a toner image on the recording medium fed from the paper feed device 20.

[0021] The paper feeder 20 supplies recording media to the image forming unit 10. Specifically, it has multiple paper stacking sections 21 and 22 that accommodate recording media of different types (e.g., material, thickness, paper size, paper grain), and supplies recording media fed from any one of these paper stacking sections 21 and 22 to the image forming unit 10.

[0022] The paper discharge unit 30 discharges the recording medium on which the toner image has been formed in the image forming unit 10 and fixed in the fixing device 17. For this purpose, the paper discharge unit 30 is equipped with a transport path 30a for transporting the fixed recording medium and a paper discharge storage unit T1 for accommodating the discharged recording medium. Furthermore, when toner images are formed on both sides of the recording medium, it is equipped with a paper reversal unit 18 that reverses the front and back of the recording medium and sends it to the paper transport device 16b. The paper discharge unit 30 may also have functions for post-processing such as cutting or stapling the paper stack output from the image forming unit 10.

[0023] The operation display unit 40 is used for inputting various settings and instructions, and for displaying information. In other words, it corresponds to the so-called user interface and is composed of a combination of a liquid crystal display panel, various operation buttons, a touch panel, etc.

[0024] The image processing unit 50 is configured, for example, as a dedicated processor or processing board, and performs image processing such as color correction and gradation correction. The data processed by the image processing unit 50 is sent to the image forming unit 10.

[0025] (1.2) Configuration and operation of the image forming unit In this type of image forming apparatus 1, the recording medium is fed to the image forming unit 10 from the paper stacking units 21 and 22, which are specified in the print job for each sheet of paper to be printed, in accordance with the timing of image formation.

[0026] The image forming unit 10 includes a photoreceptor unit 13 and a developing device 14.

[0027] The photoreceptor unit 13 is located below the exposure device 12, with each unit arranged in parallel and equipped with a photoreceptor drum 31 that acts as a rotating image holder. The charger 32, exposure device 12, developing device 14, primary transfer roller 52, and cleaning device 33 are arranged along the rotation direction of the photoreceptor drum 31 (indicated by arrows in the figure).

[0028] The developing unit 14 has a developing roller 42 positioned opposite the photoreceptor drum 31, serving as a developer holder. Each developing unit 14 is configured in substantially the same way except for the developer, and each developing roller 42 forms yellow (Y), magenta (M), cyan (C), and black (K) toner images on the opposing photoreceptor drums 31.

[0029] Above the developing unit 14 are a replaceable toner cartridge TC for storing toner and a toner supply device (not shown) that supplies toner and carrier from each toner cartridge TC to the developing unit 14.

[0030] The surface of the rotating photoreceptor drum 31 is uniformly charged by the charger 32, and an electrostatic latent image is formed by latent image forming light emitted from the exposure device 12. The electrostatic latent image formed on the photoreceptor drum 31 is developed as a toner image by the developing roller 42.

[0031] The transfer device 15 is configured to include an intermediate transfer belt 51 on which the toner images of each color formed on the photoreceptor drum 31 of each photoreceptor unit 13 are transferred in multiple layers, a primary transfer roller 52 that sequentially transfers the toner images of each color formed on each photoreceptor unit 13 to the intermediate transfer belt 51 (primary transfer), and a secondary transfer roller 53 that transfers the toner images of each color superimposed and transferred on the intermediate transfer belt 51 to the recording medium all at once (secondary transfer).

[0032] The toner images of each color formed on the photoreceptor drum 31 of each photoreceptor unit 13 are sequentially electrostatically transferred (primary transfer) onto the intermediate transfer belt 51 by a primary transfer roller 52 to which a predetermined transfer voltage is applied from a power supply unit (not shown) controlled by the system control device 11, thereby forming a superimposed toner image in which each color toner is superimposed.

[0033] As the intermediate transfer belt 51 moves, the superimposed toner image is transported to the secondary transfer section TR, where the secondary transfer roller 53 is pressed against the backup roller 65 via the intermediate transfer belt 51. When the superimposed toner image is transported to the secondary transfer unit TR, the recording medium is supplied to the secondary transfer unit TR from the paper feed device 20 at the same time. Then, a predetermined secondary transfer voltage is applied to the backup roller 65 facing the secondary transfer roller 53 via the intermediate transfer belt 51 from a power supply device (not shown) controlled by the system control device 11, and the multiple toner images on the intermediate transfer belt 51 are transferred onto the recording medium all at once.

[0034] Residual toner on the surface of the photoreceptor drum 31 is removed by the cleaning device 33 and collected in the waste toner storage unit (not shown). Then, the surface of the photoreceptor drum 31 is uniformly recharged by the charger 32, and the next image forming cycle begins.

[0035] The fixing device 17 has an endless fixing belt 17a that rotates in one direction and a pressure roller 17b that contacts the circumferential surface of the fixing belt 17a and rotates in one direction, and a nip portion (fixing region) is formed in the pressure contact area between the fixing belt 17a and the pressure roller 17b. The recording medium onto which the toner image has been transferred in the transfer device 15 is transported to the fuser device 17 via the paper transport device 16a while the toner image is still unfixed. In the fuser device 17, the recording medium is heated and pressurized by a pair of fuser belts 17a and pressure rollers 17b to fix the toner image.

[0036] Once fixing is complete, the recording media are fed to the paper output section 30 and stacked on the paper output storage section T1. Further post-processing, such as cutting or stapling, is performed as needed.

[0037] (2) Developing device Figure 3 is a schematic vertical cross-sectional view showing the configuration of the developing apparatus 14, and Figure 4 is a schematic horizontal cross-sectional view unfolded along the A, B, and C lines illustrating the transport of the developer within the developing apparatus 14. The configuration and operation of the developing device 14 will be described below with reference to the drawings.

[0038] (2.1) Overall configuration of the developing apparatus The developing apparatus 14 includes a developing container 41 that contains a developer containing toner and a carrier, a developing roller 42 as an example of a developer holder that holds the developer and transports it to a developing area facing the photoreceptor drum 31, a supply auger 43 that transports the developer through the developing roller 42 while agitating it, an admix auger 44 that transports the developer to the supply auger 43 while agitating it, a counter auger 45 that transports the developer peeled off from the developing roller 42 in the opposite direction to the transport direction of the admix auger 44, and a layer thickness regulating member 46 that regulates the amount (layer thickness) of developer held on the developing roller 42.

[0039] (2.2) Circulation of developer As shown in Figure 3, the developing container 41 is provided with a developer storage section 41A and a developer storage section 41B, which are formed in a substantially cylindrical cross-section, in order to house the supply auger 43 and the admix auger 44. The developer storage section 41B is separated from the developer container 41 by a partition wall 41a and is located adjacent to the developer storage section 41A in the vertical direction below. The developer container 41 is also provided with a developer storage section 41C for storing the developer peeled off from the counter auger 45 and the developer roller 42 and for transporting the developer in the opposite direction to the transport direction of the admix auger 44. Furthermore, as schematically shown in Figure 4, openings 41b and 41c are provided at both longitudinal ends of the partition wall 41a, respectively, for the transfer of developer between the supply auger 43 and the admix auger 44, which are arranged vertically adjacent to each other.

[0040] The Admix auger 44 agitates the developer in the developer container 41B while transporting it in the direction of arrow (Y), and the supply auger 43 agitates the developer in the developer container 41A while transporting it in the direction of arrow (-Y). The developer transported in the direction of arrow (Y) moves from the opening 41b to the developer container 41A (is pumped up), and the developer transported in the direction of arrow (-Y) moves from the opening 41c to the developer container 41B (falls). As a result, the developer in the developing container 41 is circulated and agitated by the Admix auger 44 and the Supply auger 43. This agitation of the developer causes the toner in the developer to become electrically charged.

[0041] The developing roller 42 has a magnetic roller 42A fixedly supported in the developing container 41 and a developing sleeve 42B rotatably supported on the outer circumference of the magnetic roller 42A. The magnetic roller 42A has a total of five magnetic poles: three north poles N1, N2, and N3 and two south poles S1 and S2. The magnetic poles are arranged in the order S1, N1, S2, N3, and N2 in the direction of rotation of the developing sleeve 42B, with S1 positioned in the developing area facing the photoreceptor drum 31.

[0042] The developing roller 42 rotates while the developing agent in the developing agent container 41A, which is being agitated by the supply auger 43, is attracted to the developing sleeve 42B by the magnetic force of the magnetic roller 42A, thereby transporting the developing agent from the developing container 41 to the developing area facing the photoreceptor drum 31. In the developing area, the electrostatic latent image formed on the surface of the photoreceptor drum 31 is developed, and the developed agent returns to the developing container 41 by the rotation of the developing roller 42.

[0043] (2.3) Layer thickness regulating member Figure 5 illustrates the configuration of the layer thickness regulating member 46 according to this embodiment, with Figure 5(a) being a front view and Figure 5(b) being a longitudinal cross-sectional view. Figure 6 illustrates the configuration of the magnetic plate 48, with Figure 6(a) being a front view and Figure 6(b) being a longitudinal cross-sectional view. Figure 7 illustrates the attachment of the layer thickness regulating member 46 to the developing roller 42. The configuration and function of the layer thickness regulating member 46 will be described below with reference to the drawings.

[0044] As shown in Figure 3, a layer thickness regulating member 46 extending along the axis of the developing roller 42 is fixed to the developing container 41 at both axial ends by screws SW. The tip of the layer thickness regulating member 46 is positioned opposite the developing sleeve 42B, and it regulates the thickness of the developer layer adhering to the developing sleeve 42B.

[0045] As shown in Figure 5, the layer thickness regulating member 46 has a non-magnetic plate 47 and a magnetic plate 48. The non-magnetic plate 47 is a rectangular plate-shaped member, formed from a non-magnetic metal material such as stainless steel with a thickness of 2 mm. The non-magnetic plate 47 has grooves 47a, 47a formed along its length. The magnetic plate 48 is fixed to the non-magnetic plate 47 by fitting snaps 49, which are provided on the mounting portion 48B of the magnetic plate 48 (described later), into the grooves 47a, 47a. Note that if the magnetic plate 48 is attached by adhesive without using snaps, the grooves 47a, 47a are unnecessary.

[0046] The non-magnetic plate 47 has screw through holes 47b, 47b formed at both longitudinal ends through which the screw SW passes. As will be described later, the layer thickness regulating member 46 is symmetrical with respect to the rotation direction of the developing roller 42, and can be attached to either the front or back side (upstream or downstream side in the rotation direction of the developing roller 42) using the screw through holes 47b, 47b, making it less likely to make a mistake when assembling the layer thickness regulating member 46 to the developing container 41.

[0047] As shown in Figure 6, the magnetic plate 48 is a thin plate member with a U-shape or U-shaped cross-section, and is formed of a magnetic metal material with a thickness of more than 0.3 mm. The magnetic plate 48 has a restricting portion 48A positioned opposite the developing sleeve 42B of the developing roller 42, and mounting portions 48B, 48B formed by bending the magnetic plate 48B so as to intersect with the restricting portion 48A and attaching it to the non-magnetic plate 47. Thus, the magnetic plate 48, consisting of the restricting portion 48A and the mounting portions 48B, 48B, is formed to be symmetrical on the upstream and downstream sides with respect to the normal N in the rotation direction of the developing roller 42 (indicated by arrow R in the figure) when positioned opposite the developing roller 42, as shown in Figure 7. As a result, the layer thickness restricting member 46 can be attached to either the front or back side (upstream or downstream side in the rotation direction of the developing roller 42).

[0048] Snaps 49, 49 are formed at one end of the mounting portions 48B, 48B. The snaps 49, 49 are formed as protrusions that project inward from the mounting portions 48B, 48B by bending one end of the mounting portions 48B, 48B inward. In this manner, the magnetic plate 48, with snaps 49, 49 formed at one end of the mounting portions 48B, 48B, is fitted onto the non-magnetic plate 47 so as to cover the tip, and the snaps 49, 49 fit into the grooves 47a, 47a of the non-magnetic plate 47, thereby fixing it to the non-magnetic plate 47. Alternatively, the magnetic plate 48 may be fixed to the non-magnetic plate 47 by applying adhesive or the like to the inner surfaces of the mounting portions 48B, 48B and the regulating surface portion 48A, without providing snaps 49, 49 at one end of the mounting portions 48B, 48B.

[0049] Figure 8 is an explanatory diagram showing the relationship between the gap TG between the tip of the layer thickness regulating member 46 and the surface of the developing sleeve 42B and the amount of developer adhering to the developing roller 42 after layer thickness regulating, according to the thickness of the magnetic plate 48. When the gap TG (TG: trimmer gap) between the restricting portion 48A of the magnetic plate 48 and the surface of the developing sleeve 42B is widened, the amount of developer adhering per unit area of ​​the developing roller 42 after the layer thickness restriction (MOS [g / m²]) 2 ]) increases. At this time, MOS also changes depending on the thickness of the magnetic plate 48. As shown in Figure 8, when the thickness of the magnetic plate 48 is small (0.03 mm: thin) in response to the change in gap TG, the amount of MOS fluctuation is large, and when the thickness of the magnetic plate 48 is large (0.3 mm: thin), the amount of MOS fluctuation is small.

[0050] When the developer, which is conveyed in the rotational direction of the developing roller 42 (developing sleeve 42B), reaches the vicinity of the layer thickness regulating member 46, it forms a spike by the trimming magnetic pole N1. This spike of developer is regulated by the layer thickness regulating member 46, so that it is formed on the developing roller 42 as a developer layer of a predetermined thickness (MOS). At this time, it is presumed that the thicker the magnetic plate 48, the higher the magnetic field line density formed between the developing roller 42 and the magnetic roller 42A, and the greater the regulating effect of the developer in the gap TG.

[0051] "Variations" Figure 9 illustrates the configuration of a modified layer thickness restricting member 460, with Figure 9(a) being a front view and Figure 9(b) being a longitudinal cross-sectional view. In the modified layer thickness regulating member 460, the regulating portion 462A is formed in a convex shape toward the developing sleeve 42B of the developing roller 42. As shown in Figure 9, an R shape is preferred for the convex shape. By making the regulating portion 462A R shape, the amount of developer (MOS [g / m²]) per unit area of ​​the developing roller 42 after layer thickness regulating can be controlled. 2 It becomes more stable with less of the ]) and can be made into a thinner layer.

[0052] (2.4) Operation of the developing device The developing apparatus 14 includes a developing container 41 capable of housing a developer containing toner and a carrier, a developing roller 42 positioned inside the developing container 41 that rotates while holding the developer in a developing sleeve 42B, and a layer thickness regulating member 46 whose tip is positioned opposite the developing sleeve 42B of the developing roller 42 and which regulates the layer thickness of the developer held by the developing roller 42. The layer thickness regulating member 46 has a non-magnetic plate 47 whose longitudinal ends are fixedly supported, and a magnetic plate 48 that is formed symmetrically with respect to the rotation direction of the developing roller 42 and fitted to cover the tip of the non-magnetic plate 47 that faces the developing roller 42. This makes it possible to attach the layer thickness regulating member 46 regardless of whether it is facing upstream or downstream in the rotation direction of the developing roller 42.

[0053] The magnetic plate 48 has a restricting portion 48A positioned opposite the developing sleeve 42B of the developing roller 42, and mounting portions 48B, 48B formed by bending the magnetic plate 48A so as to intersect with the restricting portion 48A, and attached to the non-magnetic plate 47. This allows the magnetic plate 48 to be easily and accurately attached to the non-magnetic plate 47.

[0054] The magnetic plate 48 is fixed to the non-magnetic plate 47 by snaps 49, 49 formed on the mounting portions 48B, 48B that fit into grooves 47a, 47a formed on the non-magnetic plate 47. This allows the magnetic plate 48 to be easily attached to the non-magnetic plate 47 without using screws or adhesives, and also increases the rigidity of the layer thickness regulating member 46.

[0055] The regulating portion 48A may be convex toward the developing sleeve 42B of the developing roller 42. This allows for a thinner layer of developer.

[0056] The magnetic plate 48 has a thickness of at least 0.3 mm. This reduces variations in the thickness of the developer layer, allowing for thinner layers.

[0057] (Note) This specification discloses at least the following inventions: (((1))) A developing container capable of housing a developer containing toner and carrier, A developer holder is placed inside the developing container and rotates while holding the developer on its surface, A layer thickness regulating member, the tip of which is positioned opposite the surface of the developer holder, regulates the layer thickness of the developer held in the developer holder, the layer thickness regulating member comprising: a non-magnetic plate with both longitudinal ends fixedly supported; and a magnetic plate formed symmetrically with respect to the rotational direction of the developer holder and fitted so as to cover the tip of the non-magnetic plate that faces the developer holder, A developing apparatus characterized by the following features. (((2))) The magnetic plate has a restricting portion positioned opposite the surface of the developer holder, and a mounting portion formed by bending the plate so as to intersect the restricting portion and attached to the non-magnetic plate. The developing apparatus according to (((1))), characterized in that (((3))) The magnetic plate is fixed to the non-magnetic plate by a snap formed in the mounting portion fitting into a groove formed in the non-magnetic plate. The developing apparatus according to (((2))), characterized in that (((4))) The regulating portion is convex toward the surface of the developer holder. The developing apparatus according to (((2))) or (((3))), characterized in that (((5))) The magnetic plate has a thickness of at least 0.3 mm. A developing apparatus according to any one of (((1))) to (((4))), characterized by the above. (((6))) An image holder that holds an electrostatic latent image, A developing means for developing the electrostatic latent image of the image holder, Equipped with, An image forming apparatus using a developing device as described in any of (((1))) to (((5))) as the developing means.

[0058] According to the inventions described in (((1))) and (((6))), the layer thickness regulating member can be attached regardless of whether it is on the upstream or downstream side in the rotation direction of the developer holder. According to the invention described in (((2))), a magnetic plate can be easily and accurately attached to a non-magnetic plate. According to the invention described in (((3))), a magnetic plate can be easily attached to a non-magnetic plate without using screws or adhesives, and the rigidity of the layer thickness regulating member can be increased. According to the invention described in (((4))), the thickness of the developer layer can be made even thinner. According to the invention described in (((5))), variations in the thickness of the developer layer can be reduced, and the layer can be made thinner. [Explanation of symbols]

[0059] 1. Image forming apparatus 10. Image Forming Unit 11. System Control Unit 12. Exposure equipment 13. Photoconductor Unit 14...Developing device, 41...Developing container, 41A, 41B, 41C...Developer storage section, 41a...Partition wall, 41b, 41c...Opening, 42...Developing roller, 42A...Magnetic roller, 42B...Developing sleeve, 43...Supply auger, 44...Addmix auger, 45...Counter auger, 46, 460...Layer thickness regulating member, 47...Non-magnetic plate, 47a...Groove section, 47b...Screw through hole, 48...Magnetic plate, 48A, 462A...Regulating section, 48B...Mounting section, 49...Snap 15. Transfer device 17. Fixing device 20. Paper feeder 30... Paper output section 40...Operation display section 50...Image Processing Unit

Claims

1. A developing container capable of housing a developer containing toner and carrier, A developer holder is placed inside the developing container and rotates while holding the developer on its surface, A layer thickness regulating member, the tip of which is positioned opposite the surface of the developer holder, regulates the layer thickness of the developer held in the developer holder, the layer thickness regulating member comprising: a non-magnetic plate with both longitudinal ends fixedly supported; and a magnetic plate formed symmetrically with respect to the rotational direction of the developer holder and fitted so as to cover the tip of the non-magnetic plate that faces the developer holder, A developing apparatus characterized by the following features.

2. The magnetic plate has a restricting portion positioned opposite the surface of the developer holder, and a mounting portion formed by bending the plate so as to intersect the restricting portion and attached to the non-magnetic plate. The developing apparatus according to feature 1.

3. The magnetic plate is fixed to the non-magnetic plate by a snap formed in the mounting portion fitting into a groove formed in the non-magnetic plate. The developing apparatus according to feature 2.

4. The regulating portion is convex toward the surface of the developer holder. The developing apparatus according to feature 2.

5. The magnetic plate has a thickness of at least 0.3 mm. The developing apparatus according to any one of claims 1 to 4.

6. An image holder that holds an electrostatic latent image, A developing means for developing the electrostatic latent image of the image holder, Equipped with, An image forming apparatus using the developing apparatus described in any one of claims 1 to 5 as the developing means.

Images