JP6641986B2 - Developing device and image forming device - Google Patents

Description

  The present invention relates to a developing device and an image forming apparatus that form an image by an electrophotographic method. Note that the image forming apparatus includes a digital copying machine, a facsimile, an electrophotographic device such as a printer, a recording device, a display device, and the like irrespective of color or monochrome.

  2. Description of the Related Art In an electrophotographic image forming apparatus such as a copier, a printer, a facsimile, and a multifunction peripheral, a developing device supplies a developer to an electrostatic latent image formed on a photoconductor to form a toner image. The developing device includes a developer replenishing unit, a developing tank, a developer supply member, a developer carrier, a regulating member, and a developer stirring / conveying member.

  The replenished developer is agitated and transported by a developer agitating and transporting member in the developing tank, and is supplied onto the developer carrying member via a developer supplying member. The excess amount of the developer supplied onto the developer carrier is removed by the regulating member, so that the amount of the developer transported is made uniform, and is transported to the opposing portion of the photoreceptor as it is.

  When unevenness occurs without uniformity in the amount of developer transported at the photoconductor-facing portion, shading unevenness occurs according to unevenness in the amount of developer transported. In the following, the main cause of the unevenness in the developer conveyance amount is that when the developer is supplied from the developer supply member composed of a screw or the like to the developer carrier, the developer is formed at the crests and valleys of the screw. Since the amount is uneven, the developer conveyance amount unevenness corresponding to the screw pitch occurs on the developer carrying member. In order to cope with such a problem, current developing devices use a regulating member prepared with high accuracy to suppress unevenness in the amount of transported developer.

  In recent years, in order to cope with further cost reductions, longevity of members has been promoted for the purpose of reducing component costs, simplifying apparatuses, and reducing replacement costs. Specifically, in order to reduce the amount of charged developer, simplify the developing device including the regulating member, and extend the life of the developer, the amount of developer supplied to the developer carrier is reduced to reduce the stress on the developer. Measures such as suppression.

  Heretofore, a large amount of developer has been supplied to the regulating member, and an excess amount of the developer has been removed by the regulating member, thereby obtaining a uniform amount of developer transport. However, if measures are taken to reduce the amount of developer supplied to the developer carrying member, it becomes difficult to secure a sufficient amount of developer before the regulating member to absorb uneven supply in the longitudinal direction. There is a concern that the function of evenly leveling the developer may be reduced, and uneven conveyance may occur in the longitudinal direction.

  In addition, the strength of the regulating member is insufficient due to simplification accompanying cost reduction, and when used for a long time, the regulating member is curved, the gap between the developer carrier and the regulating member changes in the longitudinal direction, and the longitudinal direction is changed. Of the developer transport amount.

  In Japanese Patent Application Laid-Open No. 2005-91953 (Patent Literature 1), by using a magnet as the regulating member, the magnetic field lines of the magnet inside the developer carrying member are easily concentrated on the regulating member, and the developer can be regulated by magnetic force. And With this configuration, the sensitivity of the developer conveyance amount to the gap between the developer carrier and the regulating member is reduced. Further, by changing the cross-sectional area of the magnetic member in accordance with the curvature, the developer transport amount in the longitudinal direction is made uniform.

JP 2005-91953 A

  However, when the supply amount of the developer is reduced in the above-described configuration, screw unevenness caused by the use of the screw used as the developer stirring / conveying member occurs before the regulating portion.

  Such uneven developer transport amount in the longitudinal direction, which occurs before the regulating portion, is less likely to be affected by the regulating member. In order to suppress unevenness in the amount of developer transport such as screw unevenness, it is necessary to move the developer in the longitudinal direction in order to eliminate the difference in the amount of developer between the peak and the valley.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been developed in consideration of developing agent transport amount unevenness occurring on a developer carrier before a regulating member provided in a developing device. An object of the present invention is to provide a developing device having a configuration capable of achieving a uniform amount of an agent, and an image forming apparatus having the developing device.

  The image forming apparatus includes a developer supply mechanism that supplies a developer, and a cylindrical development sleeve that carries the developer supplied from the developer supply mechanism and transports the developer in a rotation direction. A developer carrying member; and a regulating member disposed opposite to the developing sleeve at a predetermined interval and extending along the axial direction of the developing sleeve.

  A magnet member is arranged at a position facing the developing sleeve of the regulating member, and the magnet member includes a magnet body arranged along a direction obliquely intersecting the axial direction.

  In another embodiment, the magnet member has the magnet body and the non-magnetic body alternately and repeatedly arranged along the axial direction.

  In another embodiment, the magnet member is configured such that the magnet body and the magnetic member are alternately and repeatedly arranged along the axial direction.

  In another embodiment, the magnet member has the N-pole magnet body and the S-pole magnet body alternately and repeatedly arranged.

  In another embodiment, when viewed along the movement direction of the developing sleeve, the magnet body passes through both the one magnet body and the one non-magnetic body part of the magnet member. Are located.

  In another embodiment, the developer supply mechanism includes a supply screw for supplying a developer to the developing sleeve, wherein the thickness of the magnet member is A (mm), the width of the magnet body is B (mm), When the intersection angle between the axial direction and the direction in which the magnet body is arranged is θ (°) and the screw pitch of the supply screw is D (mm), the relationship of A / tan θ> D is satisfied. .

  This image forming apparatus includes any of the developing devices described above.

  According to the developing device and the image forming apparatus, the unevenness in the amount of the developer transported on the developer carrier before the regulating member provided in the developing device can be made uniform in the longitudinal direction of the developer carrier. And an image forming apparatus including the developing device.

FIG. 1 is a schematic diagram illustrating an overall configuration of an image forming apparatus according to an embodiment. FIG. 2 is a side view illustrating a configuration of a developing device used in the image forming apparatus according to the embodiment. FIG. 2 is a side view illustrating a configuration of a developing device used in the image forming apparatus according to the embodiment. FIG. 2 is a side view illustrating a configuration of a developing roller and a regulating member according to the first exemplary embodiment. FIG. 2 is a top view illustrating a configuration of a regulating member of the developing device according to the first exemplary embodiment. FIG. 9 is a side view illustrating a configuration of a developing roller and a regulating member according to a second exemplary embodiment. FIG. 9 is a top view illustrating a configuration of a regulating member of a developing device according to a second exemplary embodiment. FIG. 13 is a side view illustrating a configuration of a developing roller and a regulating member according to a third embodiment. FIG. 13 is a top view illustrating a configuration of a regulating member of a developing device according to a third embodiment. FIG. 13 is a side view illustrating a configuration of a developing roller and a regulating member according to a fourth embodiment. FIG. 14 is a top view illustrating a configuration of a regulating member of a developing device according to a fourth embodiment. FIG. 9 is a side view illustrating a configuration of a developing roller and a regulating member in Comparative Example 1. FIG. 9 is a side view illustrating a configuration of a developing roller and a regulating member in Comparative Example 2. FIG. 9 is a diagram illustrating a configuration of a regulating member of a developing device in Comparative Example 2. It is a figure which shows the evaluation result in Examples 1-4 and Comparative Examples 1-2. It is a figure showing a judgment standard. FIG. 9 is a diagram illustrating a relationship between “a gap between a developing roller and a regulating member” and “developer conveyance amount” in Examples 1 to 4 and Comparative Examples 1 and 2. It is a figure which shows the evaluation result at the time of changing an inclination angle in Examples 1-4. FIG. 3 is a partially enlarged view showing a relationship among a plate thickness of a magnet member, a width of a magnet body, a width of a non-magnetic body, an intersection angle °, and a screw pitch in Example 1.

  Hereinafter, a developing device and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the embodiments described below, when referring to the number, the amount, and the like, the scope of the present invention is not necessarily limited to the number, the amount, and the like, unless otherwise specified. The same components and corresponding components are denoted by the same reference numerals, and duplicate description may not be repeated. In addition, in the drawings, some parts are not shown according to the ratios of the actual dimensions, but are shown with the ratios changed so as to make the structure clear in order to facilitate understanding of the structure.

(Image forming apparatus 100)
With reference to FIG. 1, a schematic configuration of image forming apparatus 100 according to the present embodiment will be described. FIG. 1 is a schematic diagram showing the overall configuration of the image forming apparatus 100.

  Around a photoreceptor 1 as an image carrier, a cleaning device 2, a charging unit 3, a writing device 4 (only scanning light from the writing device is shown in the figure), a developing device 5 (a developing roller 51 in the figure, And a recording material 6 such as a transfer sheet. Although well-known devices such as a paper feeding device and a fixing device are also provided, description thereof is omitted here.

  The photoconductor 1 is driven to rotate by a driving unit (not shown). The surface of the photoconductor 1 is uniformly charged by the charging unit 3. The charged surface of the photoconductor 1 is irradiated with scanning light from the writing device 4. As a result, an electrostatic latent image is formed on the surface of the photoconductor 1. A developer is applied to the electrostatic latent image from the developing device 5, and a toner image is visualized on the surface of the photoconductor 1. The toner image is transferred from the surface of the photoconductor 1 to the recording material 6. Further, the toner image transferred onto the recording material 6 is fixed by a fixing device (not shown). The toner remaining on the photoconductor 1 after the transfer is removed by the cleaning device 2. As the developer, a two-component developer containing a toner and a magnetic carrier is used.

(Developing device 5)
The configuration of the developing device 5 used in the image forming apparatus 100 will be described with reference to FIGS. FIG. 2 is a side view showing the configuration of the developing device 5 and FIG. 3 is a side view showing the configuration of the developing device.

  The developing device 5 is a two-component developing device that develops the electrostatic latent image on the photoconductor 1, and turns the electrostatic latent image into a visible toner image by reversal development using negatively charged toner particles.

  The developing device 5 has a housing 55 for housing the developer, and at a predetermined position inside the housing 55, the developing roller 51, the supply screw 53, and And a stirring screw 54 are accommodated. A regulating member 52 is provided at a position facing the surface of the developing roller 51.

  The developing roller 51, the supply screw 53, and the stirring screw 54 are arranged in parallel along the direction extending in the direction of the respective rotation axes (the L1 direction in the drawing). In FIG. 3, the screw pitch of the supply screw 53 and the stirring screw 54 is D (mm).

  The stirring screw 54 mainly functions as a stirring member for stirring the toner particles, and the supply screw 53 mainly has a function of conveying the toner particles to the developing roller 51. The supply screw 53 and the stirring screw 54 function as a developer supply mechanism for supplying the developer to the developing roller 51.

  The regulating member 52 is located on the surface of the developing roller 51, is opposed to the rotating developing sleeve 511 (see FIG. 4) at a predetermined interval (Dd), and extends along the axial direction L1 of the developing sleeve 511. have.

Hereinafter, each embodiment of the developing device 5 having the above configuration will be described.
(Example 1)
The configurations of the developing roller 51 and the regulating member 52 in the first embodiment will be described in detail with reference to FIGS. FIG. 4 is a side view illustrating the configuration of the developing roller 51 and the regulating member 52 according to the first embodiment. FIG. 5 is a top view illustrating the configuration of the regulating member 52 according to the first embodiment.

  Referring to FIG. 4, developing roller 51 includes a developing sleeve 511 that houses magnet roller 512. On the outer surface of the magnet roller 512, N-pole magnetism and S-pole magnetism are alternately arranged. The developing sleeve 511 and the magnet roller 512 are connected by a flange (not shown) provided at each end, and the developing sleeve 511 is rotatably provided with respect to the magnet roller 512 by a bearing (not shown). .

  The regulating member 52 includes a regulating blade 522 and a magnet member 521 at a position facing the developing sleeve 511. The magnet member 521 is attached to the regulating blade 522 using an adhesive or the like. Note that a method of applying a powder magnet to the surface of the developing sleeve 511 or the regulating member itself may be made of a magnet (magnetic powder + resin).

  Referring to FIG. 5, magnet member 521 includes a magnet body 521b arranged along a direction obliquely intersecting axial direction L1. The directions of intersection may be opposite. In this embodiment, magnet bodies 521b and non-magnetic bodies 521a are alternately and repeatedly arranged along the axial direction L1. In this embodiment, aluminum, stainless steel, or the like is used for the regulating blade 522 and the non-magnetic body 521a.

  4 and 5, F1 indicates the rotation direction of the developing sleeve 511, that is, the moving direction of the developer as viewed from the magnet member 521 (the regulating member 52), and θ (°) indicates the axial direction L1. And the direction in which the magnet body 521b is arranged. In the present embodiment, θ = 15 °. A indicates the width (plate thickness) of the regulating member 52 along the F1 direction, B indicates the width of the magnet body 521b along a direction inclined by θ (°) with respect to the axial direction L1, and C Indicates the width of the non-magnetic body 521a along the direction inclined by θ (°) with respect to the axial direction L1. In this embodiment, A = 1.6 mm and B = C = 1 mm.

  According to the developing roller 51 and the regulating member 52 having the above configuration, the following operation and effect can be obtained. The developer conveyed and supplied by the stirring screw 54 and the supply screw 53 (see FIG. 3) is supplied to the developer roller 51 at a position in front of the regulating member 52 on the developing roller 51 at the crests and valleys of the screw. , The unevenness in the amount of developer transport corresponding to the ridges and valleys of the screw also occurs on the developing roller 51.

  At the time of passage through the regulating member 52, the pressure applied to the developer is high in the peak portion where the amount of the developer is large, and the pressure in the valley portion is low. In this embodiment, since the magnet body 521b is arranged at an angle to the direction of travel of the developer, a part of the developer passing through the regulating member 52 moves in the axial direction L1 under the influence of the magnetic force. I do. In the movement in the axial direction L1, the peaks where the pressure applied to the developer is high are easy to move, and the valleys are difficult to move. Therefore, when the developer passes through the regulating member 52, the unevenness of the screw can be eliminated or reduced because the developer in the peak moves to the valley and is leveled.

  Further, in the present embodiment, since the magnet member 521 is used to improve the regulation ability by magnetism, the sensitivity of the developer conveyance amount to the gap between the developing roller 51 and the regulation member 52 is reduced.

  Therefore, the strength of the regulating member 52 is insufficient due to the simplification accompanying the cost reduction, and even if the regulating member 52 is curved and the gap between the developing roller 51 and the regulating member 52 changes in the longitudinal direction, the unevenness in the amount of developer transported. Can be suppressed.

(Example 2)
The configurations of the developing roller 51 and the regulating member 52A in the second embodiment will be described in detail with reference to FIGS. FIG. 6 is a side view illustrating the configuration of the developing roller 51 and the regulating member 52A in the second embodiment, and FIG. 7 is a top view illustrating the configuration of the regulating member 52A in the second embodiment. Note that the configuration of the developing roller 51 is the same as that of the first embodiment, and a duplicate description will be omitted.

  The regulating member 52A includes a regulating blade 522 and a magnet member 521A at a position facing the developing sleeve 511. The magnet member 521A is attached to the regulating blade 522 using an adhesive or the like. Note that a method of applying a powder magnet to the surface of the developing sleeve 511 or the regulating member itself may be made of a magnet (magnetic powder + resin).

  Referring to FIG. 7, magnet member 521A includes a magnet body 521b arranged along a direction obliquely intersecting axial direction L1. The directions of intersection may be opposite. In this embodiment, the magnet bodies 521b and the magnetic bodies 521c are alternately and repeatedly arranged along the axial direction L1. In this embodiment, aluminum is used for the regulating blade 522, and SUS430 is used for the magnetic body 521c.

  6 and 7, F1 indicates the rotational direction of the developing sleeve 511, that is, the moving direction of the developer as viewed from the magnet member 521A (the regulating member 52A), and θ (°) indicates the axial direction L1. And the direction in which the magnet body 521b is arranged. In the present embodiment, θ = 15 °. A indicates the width (plate thickness) of the regulating member 52A along the F1 direction, B indicates the width of the magnet body 521b along a direction inclined by θ (°) with respect to the axial direction L1, and C Indicates the width of the non-magnetic body 521a along the direction inclined by θ (°) with respect to the axial direction L1. In this embodiment, A = 1.6 mm and B = C = 1 mm.

  With the developing roller 51 and the regulating member 52A having the above-described configuration, the same effect as that of the first embodiment can be obtained. Further, since the magnet bodies 521b and the magnetic bodies 521c are alternately arranged, the sensitivity of the transport amount of the developer at the interval (Dd) between the magnet member 521A and the developing sleeve 511 is smaller than that in the first embodiment. Can be lowered.

(Example 3)
The configurations of the developing roller 51 and the regulating member 52B in the third embodiment will be described in detail with reference to FIGS. FIG. 8 is a side view illustrating the configuration of the developing roller 51 and the regulating member 52B according to the third embodiment. FIG. 9 is a top view illustrating the configuration of the regulating member 52B according to the third embodiment. Note that the configuration of the developing roller 51 is the same as that of the first embodiment, and a duplicate description will be omitted.

  The regulating member 52B includes a regulating blade 522 and a magnet member 521B at a position facing the developing sleeve 511. The magnet member 521B is attached to the regulating blade 522 using an adhesive or the like. Note that a method of applying a powder magnet to the surface of the developing sleeve 511 or the regulating member itself may be made of a magnet (magnetic powder + resin).

  Referring to FIG. 9, in magnet member 521B, N-pole magnet bodies 521n and S-pole magnet bodies 521s are alternately arranged along a direction obliquely intersecting with axial direction L1. The directions of intersection may be opposite.

  8 and 9, F1 indicates the rotation direction of the developing sleeve 511, that is, the moving direction of the developer as viewed from the magnet member 521B (the regulating member 52B), and θ (°) indicates the axial direction L1. And the direction in which the N-pole magnet body 521n and the S-pole magnet body 521s are arranged. In the present embodiment, θ = 15 °. A indicates the width (plate thickness) of the regulating member 52B along the F1 direction, and B indicates the width of the N-pole magnet body 521n along a direction inclined by θ (°) with respect to the axial direction L1. , C indicate the width of the S pole magnet body 521s along a direction inclined by θ (°) with respect to the axial direction L1. In this embodiment, A = 1.6 mm and B = C = 1 mm.

  With the developing roller 51 and the regulating member 52B having the above-described configuration, the same effect as that of the first embodiment can be obtained. Further, since the N-pole magnet bodies 521n and the S-pole magnet bodies 521s are alternately arranged, the developer is transported at a distance (Dd) between the magnet member 521B and the developing sleeve 511 as compared with the second embodiment. The quantity sensitivity can be further reduced.

(Example 4)
With reference to FIGS. 10 and 11, the configurations of the developing roller 51 and the regulating member 52C in the fourth embodiment will be described in detail. FIG. 10 is a side view illustrating the configuration of the developing roller 51 and the regulating member 52C according to the fourth embodiment. FIG. 11 is a top view illustrating the configuration of the regulating member 52C according to the fourth embodiment. Note that the configuration of the developing roller 51 is the same as that of the first embodiment, and a duplicate description will be omitted.

  The regulating member 52A includes a regulating blade 522 and a magnet member 521C at a position facing the developing sleeve 511. The magnet member 521C is attached to the regulating blade 522 using an adhesive or the like. Note that a method of applying a powder magnet to the surface of the developing sleeve 511 or the regulating member itself may be made of a magnet (magnetic powder + resin).

  Referring to FIG. 11, magnet member 521C includes a magnet body 521b arranged along a direction obliquely intersecting axial direction L1. The directions of intersection may be opposite. In this embodiment, magnet bodies 521b and non-magnetic bodies 521a are alternately and repeatedly arranged along the axial direction L1. Furthermore, the inclination angle of the magnet body 521b is alternately reversed, and the magnet bodies 521b are arranged in a zigzag manner. In this embodiment, aluminum, stainless steel, or the like is used for the regulating blade 522 and the non-magnetic body 521a in this embodiment.

  10 and 11, F1 indicates the rotation direction of the developing sleeve 511, that is, the moving direction of the developer as viewed from the magnet member 521C (the regulating member 52C), and θ (°) indicates the axial direction L1. And the direction in which the magnet body 521b is arranged. In the present embodiment, θ = 15 °. A indicates the width (plate thickness) of the regulating member 52A along the F1 direction, and B indicates the width of the magnet body 521b along the direction inclined by θ (°) with respect to the axial direction L1. . In this embodiment, A = 1.6 mm and B = 1 mm.

  With the developing roller 51 and the regulating member 52C having the above configuration, the same operation and effect as those of the first embodiment can be obtained.

(Evaluation)
Next, the evaluation of Example 1-4 will be described in comparison with Comparative Example 1-2. FIG. 12 is a top view illustrating the configuration of the regulating member 52X in Comparative Example 1, FIG. 13 is a side view illustrating the configuration of the developing roller 51 and the regulating member 52Y in Comparative Example 2, and FIG. FIG. 5 is a top view illustrating a configuration of a regulating member 52Y. In Comparative Examples 1 and 2, the configuration of the developing roller 51 is the same as that in Example 1, and therefore, the duplicate description is omitted.

  In the regulation member 52X in Comparative Example 1 shown in FIG. 12, as shown in the above-described Example 1-4, the magnet member is not included in the position facing the developing sleeve 511, and the regulation member 52X is formed using aluminum. It was done. On the other hand, as shown in FIGS. 13 and 14, the regulating member 52Y in Comparative Example 2 includes a regulating blade 522 and a magnet member 521 at a position facing the developing sleeve 511. The magnet member 521 in Comparative Example 2 has a magnet member disposed on the entire surface.

  With reference to FIGS. 15 to 18, evaluation results in Examples 1 to 4 and Comparative Examples 1 and 2 will be examined. FIG. 15 is a diagram showing evaluation results in Examples 1 to 4 and Comparative Examples 1 and 2, FIG. 16 is a diagram showing criteria, and FIG. 17 is Examples 1 to 4 and Comparative Examples 1 to 4. 2 is a diagram illustrating the relationship between the “gap between the developing roller and the regulating member” and the “developer conveyance amount”, and FIG. 18 is a diagram illustrating evaluation results when the inclination angle is changed in Examples 1 to 4. .

  In the evaluation, the presence or absence of screw unevenness in the longitudinal direction of the developing roller 51 and the image evaluation were performed. The configuration of each example and each comparative example was applied to a commercially available Konica Minolta “bizhub PRO C554” (tandem color multifunction machine of laser exposure / reversal development / intermediate transfer body with a wavelength of 780 nm) manufactured by Konica Minolta. .

  This evaluation was performed in a state where the amount of developer to be filled was reduced by 40 g from a commercially available product, assuming that the amount of developer to be filled was small due to cost reduction. For this reason, even in Comparative Example 1, which is a commercial product condition, screw unevenness was confirmed in the longitudinal direction.

  Evaluation of the screw unevenness in the longitudinal direction was visually confirmed. Those that could be confirmed visually and were of NG level in terms of quality were rated "F (fail)", those that could be confirmed visually were "C (acceptable)", and those that could not be confirmed visually were "B (good)".

  In the evaluation of the image, the unevenness of the density of the image was evaluated, and the color difference ΔE between the high density portion and the low density portion was calculated from the measurement result of the meter, and the reference shown in FIG. 16 was provided. “A (excellent)” indicates a color difference ΔE <1, “B (good)” indicates 1 ≦ color difference Δ <2, “C (acceptable)” indicates 2 ≦ color difference Δ <3, and “F (fail)” Was evaluated as 3 ≦ color difference Δ.

  Referring to FIG. 15, the evaluation result of Example 1 was “B” for evaluation of screw unevenness, and “A” for image evaluation. In the evaluation results of Example 2, the evaluation of screw unevenness was “B” and the image evaluation was “A”. In the evaluation results of Example 3, the evaluation of screw unevenness was “B” and the image evaluation was “A”. In the evaluation results of Example 4, the evaluation of screw unevenness was “B”, and the image evaluation was “B”. In the evaluation results of Comparative Example 1, the evaluation of screw unevenness was “F” and the image evaluation was “F”. In the evaluation results of Comparative Example 2, the evaluation of screw unevenness was “F” and the image evaluation was “F”.

  As shown in FIG. 17, since the sensitivity of the developer conveyance amount to the gap is low, even if the gap between the developing roller 51 and the regulation member changes in the longitudinal direction due to the curving of the regulation member, the developer conveyance amount is hard to change, resulting in an image defect. Was confirmed to be suppressed. Example 3 was the most effective. In the third embodiment, since the N-pole magnet bodies 521n and the S-pole magnet bodies 521s are alternately arranged, it is considered that the line of magnetic force easily concentrates on adjacent magnets at a short distance, and the magnetic regulation force is increased.

  FIG. 18 shows the evaluation results when the inclination angle (θ) is changed in the first to fourth embodiments. As is clear from FIG. 18, when the intersection angle between the axial direction L1 and the direction in which the magnet bodies 521b are arranged is 15 ° (165 ° when the inclination is opposite), the evaluation of the screw unevenness is made. It was confirmed that "B" and the image evaluation were the best, "A".

  Furthermore, it was confirmed from the evaluation results of FIG. 18 that it is desirable that the inclination angle θ be in the range of 10 ° ≦ θ ≦ 30 ° or 150 ° ≦ θ ≦ 170 °. If the inclination angle is too small, the moving force of the developer in the longitudinal direction is weakened, and if the inclination angle is too large, the moving distance of the developer in the longitudinal direction is short, so that the effect of suppressing screw unevenness is small. Become.

  In each of the above embodiments, when the first embodiment is described as a representative example with reference to FIG. 19, the plate thickness of the magnet member is Amm, the width of the magnet body is Bmm, and the width of the nonmagnetic body is When the intersection angle between Cmm, the axial direction L1 and the direction in which the magnet body 521b is arranged is θ °, the relationship of A> B / cos θ may be satisfied. Further, it is preferable that A> C / cos θ is satisfied. That is, when viewed along the movement direction (F1) of the developing sleeve, the developer may be allowed to pass through both the portion where one magnetic material exists and the portion other than the one magnetic material.

  Accordingly, only the same magnetic pole or non-magnetic pole portion does not face the developer in the rotation direction of the developer, so that it is possible to more effectively suppress uneven conveyance in the longitudinal direction due to the magnetic pole pattern.

  Further, referring to FIG. 19, the plate thickness of the magnet member is A mm, the intersection angle between axial direction L1 and the direction in which magnet body 521b is arranged is θ °, and the screw pitch of supply screw 53 (see FIG. 3) is D. (Mm), the relationship of A / tan θ> D is preferably satisfied.

  Thereby, the developer of the screw unevenness formed by the supply screw 53 can be moved from the peak to the valley, and the occurrence of the screw unevenness of the developer can be more effectively eliminated.

  In the above-described embodiment and each example, the shape of the regulating member is not limited to the plate (blade). For example, a cylindrical shape may be adopted.

  The embodiment and each example disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  Reference Signs List 1 photosensitive member, 2 cleaning device, 3 charging means, 4 writing device, 5 developing device, 6 recording material, 51 developing roller, 52 regulating member, 52A regulating member, 52B regulating member, 53 supply screw, 54 stirring screw, 55 housing , 100 image forming apparatus, 511 developing sleeve, 512 magnet roller, 521 magnet member, 521A magnet member, 521C magnet member, 521B magnet member, 521a non-magnetic body, 521b magnet body, 521c non-magnetic body, 521n N pole magnet body, 521s S pole magnet body, 522 regulating blade.

Claims (6)

A developer supply mechanism for supplying a developer,
A developer carrying member that carries the developer supplied from the developer supply mechanism and includes a cylindrical developing sleeve that conveys the developer in a rotational direction;
A regulating member that is disposed opposite to the developing sleeve at a predetermined interval and extends along the axial direction of the developing sleeve;
With
At a position facing the developing sleeve of the regulating member, a magnet member is arranged,
The magnet member is seen containing a magnet which is arranged in a direction intersecting obliquely to the axial direction,
The magnet member is provided to extend from an upstream end to a downstream end of the regulating member,
The developer supply mechanism includes a supply screw that supplies a developer to the developing sleeve,
The thickness of the magnet member is A (mm), the width of the magnet body is B (mm), the intersection angle between the axial direction and the direction in which the magnet body is arranged is θ (°), A developing device having a relationship of A / tan θ> D when the pitch is D (mm) .   The developing device according to claim 1, wherein the magnet member is configured such that the magnet body and the nonmagnetic body are alternately and repeatedly arranged along the axial direction.   The developing device according to claim 1, wherein the magnet member and the magnetic member are alternately and repeatedly arranged along the axial direction.   The developing device according to claim 1, wherein the magnet member has the N-pole magnet body and the S-pole magnet body arranged alternately and repeatedly.   The plurality of magnet bodies are arranged so as to pass through both the one magnet body and the one non-magnetic body portion of the magnet member when viewed along the movement direction of the developing sleeve. The developing device according to claim 1. Claims 1 having a developing device according to any one of claims 5, the image forming apparatus.