JP2017116771A - Developing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device that can suppress unevenness in the amount of developer conveyed generated on a developer carrier on the near side of a regulation member provided in a developing device and can make the amount of developer uniform in the longitudinal direction of the developer carrier, and an image forming apparatus including the developing device.SOLUTION: The present developing device comprises: a developer supply mechanism that supplies a developer; a developer carrier including a cylindrical developing sleeve that carries the developer supplied from the developer supply mechanism and conveys the developer in the direction of rotation; and a regulation member that is arranged opposite to the developing sleeve 511 with a predetermined interval and extends along the axial direction L1 of the developing sleeve. A magnet member 521 is arranged at a position facing a developing sleeve 511 of the regulation member 52, and the magnet member 521 includes a magnet body 521b that is arranged along a direction intersecting obliquely with the axial direction L1.SELECTED DRAWING: Figure 5

Description

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

  In an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine, a developer is supplied from a developing device to an electrostatic latent image formed on a photoreceptor to form a toner image. The developing device includes a developer supply section, a developing tank, a developer supply member, a developer carrier, a regulating member, and a developer agitation / conveyance member member.

  The replenished developer is agitated and conveyed by the developer agitating / conveying member in the developing tank, and is supplied onto the developer carrying member via the developer supplying member. The developer supplied onto the developer carrying member is scraped by an excessive amount by the regulating member, so that the developer carrying amount is made uniform and is conveyed as it is to the opposing portion of the photoreceptor.

  When unevenness occurs because the developer conveyance amount of the photosensitive member facing portion is not uniform, unevenness in density corresponding to the unevenness of the developer conveyance amount occurs. In the following, the main cause of unevenness in the developer transport amount is that when supplying the developer from the developer supply member composed of a screw or the like to the developer carrier, the developer is at the peak and valley of the screw. Since the amount is uneven, the developer carrying amount unevenness corresponding to the screw pitch occurs on the developer carrying member. In order to cope with such a problem, the current developing apparatus uses a regulating member prepared with high accuracy to suppress unevenness in the developer conveyance amount.

  In recent years, in order to cope with further cost reduction, the lifespan of members has been promoted for the purpose of reducing component costs, simplifying devices, and reducing replacement costs. Specifically, in order to reduce the amount of the filled developer, simplify the developing device including the regulating member, and extend the life of the developer, the developer supply amount to the developer carrying member is reduced to reduce the stress on the developer. Measures such as suppression are listed.

  Until now, a large amount of developer has been supplied to the regulating member, and excess developer has been passed through the regulating member to obtain a uniform developer transport amount. However, if the measure to reduce the developer supply amount to the developer carrier is advanced, it becomes difficult to secure the developer amount that can sufficiently absorb the supply unevenness in the longitudinal direction before the regulating member, There is a concern that the function of uniformly leveling the developer is lowered, and uneven conveyance amount occurs in the longitudinal direction.

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

  In Japanese Patent Laid-Open No. 2005-91953 (Patent Document 1), the magnetic force of the magnet in the developer carrying member is easily concentrated on the regulating member by magnetizing the regulating member, and the developer can be regulated by magnetic force. It is said. With this configuration, the sensitivity of the developer conveyance amount with respect to the gap between the developer carrier and the regulating member is reduced. Furthermore, the developer conveyance amount in the longitudinal direction is made uniform by changing the cross-sectional area of the magnetic member in accordance with the curvature.

JP 2005-91953 A

  However, when the developer supply amount decreases with the above-described configuration, screw unevenness or the like that occurs due to the use of the screw used as the developer agitating / conveying member occurs before the regulating portion.

  Such uneven developer transport amount unevenness in the longitudinal direction occurring in front of the restricting portion is less likely to be affected by the restricting member. In order to suppress the developer transport amount unevenness such as screw unevenness, it is necessary to move the developer in the longitudinal direction in order to eliminate the difference in the developer amount between the crest and trough.

  An object of the present invention has been made in view of the above problems, and develops developer transport amount unevenness generated on a developer carrier in front of a regulating member provided in the developing device in the longitudinal direction of the developer carrier. It is an object of the present invention to provide a developing device having a configuration capable of making the amount of the agent uniform, and an image forming apparatus including 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 conveys the developer in a rotation direction. An agent carrier, and a regulating member that is disposed to face the developing sleeve at a predetermined interval and extends along the axial direction of the developing sleeve.

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

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

  In another embodiment, in the magnet member, the magnet body and the magnetic member are alternately and repeatedly arranged along the axial direction.

  In another embodiment, the magnet member is configured such that the N-pole magnet body and the S-pole magnet body are alternately and repeatedly arranged.

  In another form, when viewed along the direction of movement of the developing sleeve, the magnet body passes through both the one magnet body and the one other than the magnetic body in the magnet member. Has been placed.

  In another embodiment, the developer supply mechanism includes a supply screw that supplies the developer to the developing sleeve, the plate thickness of the magnet member is A (mm), the width of the magnet body is B (mm), When the crossing 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 developer transport amount unevenness generated on the developer carrying member before the regulating member provided in the developing device is uniformized in the developer amount in the longitudinal direction of the developer carrying member. It is possible to provide a developing device having a configuration capable of achieving the above and an image forming apparatus including the developing device.

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 in the embodiment. FIG. 2 is a side view illustrating a configuration of a developing device used in the image forming apparatus in the embodiment. FIG. 3 is a side view illustrating a configuration of a developing roller and a regulating member in Embodiment 1. FIG. 3 is a look-up view illustrating a configuration of a regulating member of the developing device in Embodiment 1. FIG. 10 is a side view illustrating configurations of a developing roller and a regulating member in Embodiment 2. FIG. 6 is a look-up view illustrating a configuration of a regulating member of a developing device in Embodiment 2. FIG. 10 is a side view illustrating a configuration of a developing roller and a regulating member in Embodiment 3. FIG. 10 is a look-up view illustrating a configuration of a regulating member of a developing device in Embodiment 3. FIG. 10 is a side view illustrating configurations of a developing roller and a regulating member in Embodiment 4. FIG. 10 is a look-up view illustrating a configuration of a regulating member of a developing device in Embodiment 4. 6 is a side view showing configurations of a developing roller and a regulating member in Comparative Example 1. FIG. 10 is a side view showing the configuration of a developing roller and a regulating member in Comparative Example 2. FIG. 10 is a diagram illustrating a configuration of a regulating member of a developing device in Comparative Example 2. FIG. It is a figure which shows the evaluation result in Examples 1-4 and Comparative Examples 1-2. It is a figure which shows the criterion. 6 is a diagram illustrating a relationship between “a gap between a developing roller and a regulating member” and “a developer conveyance amount” in Examples 1 to 4 and Comparative Examples 1 and 2. FIG. It is a figure which shows the evaluation result at the time of changing an inclination angle in Examples 1-4. In Example 1, it is the elements on larger scale which show the relationship of the plate | board thickness of a magnet member, the width | variety of a magnet body, the width | variety of a nonmagnetic body, crossing angle degree, and screw pitch.

  A developing device and an image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. The same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated. Further, in the drawings, there are some portions that are not illustrated in accordance with the ratio of actual dimensions, but are illustrated with the ratio changed so that the structure becomes clear in order to facilitate understanding of the structure.

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

  Around the photoreceptor 1 as an image carrier, there are a cleaning device 2, a charging means 3, a writing device 4 (only scanning light from the writing device is shown in the figure), a developing device 5 (in the figure, a developing roller 51, and A recording member 6 such as a transfer paper is disposed. Well-known devices such as a paper feeding device and a fixing device are also provided, but a description thereof is omitted here.

  The photoreceptor 1 is rotationally driven by driving means (not shown). The surface of the photoreceptor 1 is uniformly charged by the charging unit 3. The surface of the charged photoreceptor 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 photoreceptor 1. Developer is applied to the electrostatic latent image from the developing device 5, and the toner image is visualized on the surface of the photoreceptor 1. The toner image is transferred from the surface of the photoreceptor 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 photoreceptor 1 after the transfer is removed by the cleaning device 2. As the developer, a two-component developer containing 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 photoreceptor 1 and converts the electrostatic latent image into a visible toner image by reversal development with negatively charged toner particles.

  The developing device 5 includes a housing 55 that accommodates a developer. A developing roller 51, a supply screw 53, and a housing 55 can be rotated about a rotation axis with respect to the housing 55 at a predetermined position inside the housing 55. The stirring screw 54 is 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 respective rotation axis directions (L1 direction in the drawing). In FIG. 3, let the pitch of the screw of the supply screw 53 and the stirring screw 54 be D (mm).

  The stirring screw 54 mainly functions as a stirring member that stirs the toner particles, and the supply screw 53 mainly has a function of transporting the toner particles to the developing roller 51. The supply screw 53 and the stirring screw 54 function as a developer supply mechanism that supplies 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) with a predetermined interval (Dd), and extends along the axial direction L 1 of the developing sleeve 511. have.

Hereinafter, examples of the developing device 5 having the above-described configuration will be described.
Example 1
With reference to FIG. 4 and FIG. 5, the structure of the developing roller 51 and the regulating member 52 in Embodiment 1 will be described in detail. FIG. 4 is a side view illustrating the configuration of the developing roller 51 and the regulating member 52 in the first embodiment, and FIG. 5 is a top view illustrating the configuration of the regulating member 52 in the first embodiment.

  With reference to FIG. 4, the developing roller 51 includes a developing sleeve 511 that houses a 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 to each other by flanges (not shown) provided at respective end portions, and the developing sleeve 511 is rotatably provided to the magnet roller 512 by a bearing (not shown). .

  The restriction member 52 includes a restriction blade 522 and a magnet member 521 at a position facing the developing sleeve 511. The magnet member 521 is attached to the regulation 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 that is disposed along a direction that obliquely intersects axial direction L1. The intersecting directions may be opposite. In this embodiment, the magnet body 521b and the non-magnetic body 521a are alternately and repeatedly arranged along the axial direction L1. In the present embodiment, aluminum, stainless steel or the like is used for the regulating blade 522 and the nonmagnetic material 521a.

  4 and 5, F1 indicates the rotation direction of the developing sleeve 511, that is, the moving direction of the developer when viewed from the magnet member 521 (regulating member 52), and θ (°) indicates the axial direction L1. And the crossing angle with the direction in which the magnet body 521b is arranged. In this embodiment, θ = 15 °. A indicates a width (plate thickness) along the F1 direction of the regulating member 52, B indicates a 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 material 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-described configuration, the following effects can be obtained. The developer conveyed and supplied by the stirring screw 54 and the supply screw 53 (see FIG. 3) is supplied at the crest and trough of the screw at a position before the regulating member 52 on the developing roller 51. Therefore, the developer conveyance amount unevenness corresponding to the crest and trough of the screw also occurs on the developing roller 51.

  When the regulating member 52 passes, the pressure received by the developer is high at the peak where the amount of the developer is large, and the pressure at the valley is low. In the present embodiment, since the magnet body 521b is disposed at an angle with respect to the developer traveling direction, a part of the developer passing through the regulating member 52 is moved in the axial direction L1 due to the influence of the magnetic force. To do. In the movement in the axial direction L1, the crest portion where the pressure received by the developer is high is easily moved, and the trough portion is difficult to move. For this reason, when passing through the regulating member 52, the developer at the crest moves to the trough and is leveled, so that screw unevenness can be eliminated or reduced.

  Further, in the present embodiment, the magnet member 521 is used to improve the magnetic regulation capability, and therefore the sensitivity of the developer conveyance amount with respect to the gap between the developing roller 51 and the regulating member 52 is reduced.

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

(Example 2)
With reference to FIG. 6 and FIG. 7, the structure of the developing roller 51 and the regulating member 52A in Embodiment 2 will be described in detail. FIG. 6 is a side view showing the configuration of the developing roller 51 and the regulating member 52A in the second embodiment, and FIG. In addition, since the structure of the developing roller 51 is the same as that of the first embodiment, a duplicate description is omitted.

  The restriction member 52A includes a restriction blade 522 and a magnet member 521A at a position facing the developing sleeve 511. The magnet member 521A is attached to the regulation 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 that is disposed along a direction that obliquely intersects axial direction L1. The intersecting directions 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 rotation direction of the developing sleeve 511, that is, the moving direction of the developer when viewed from the magnet member 521A (regulating member 52A), and θ (°) indicates the axial direction L1. And the crossing angle with the direction in which the magnet body 521b is arranged. In this embodiment, θ = 15 °. A indicates the width (plate thickness) along the F1 direction of the regulating member 52A, B indicates the width of the magnet body 521b along the direction inclined by θ (°) with respect to the axial direction L1, and C Indicates the width of the non-magnetic material 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.

  The same effects as those of the first embodiment can be obtained by the developing roller 51 and the restricting member 52A having the above-described configuration. In addition, since the magnet bodies 521b and the magnetic bodies 521c are alternately arranged, compared to the first embodiment, the sensitivity of the developer conveyance amount in the gap (Dd) between the magnet member 521A and the developing sleeve 511 is improved. Can be lowered.

(Example 3)
With reference to FIG. 8 and FIG. 9, the structure of the developing roller 51 and the regulating member 52B in Embodiment 3 will be described in detail. FIG. 8 is a side view illustrating the configuration of the developing roller 51 and the regulating member 52B in the third embodiment, and FIG. 9 is a top view illustrating the configuration of the regulating member 52B in the third embodiment. In addition, since the structure of the developing roller 51 is the same as that of the first embodiment, a duplicate description is omitted.

  The restriction member 52B includes a restriction blade 522 and a magnet member 521B at a position facing the developing sleeve 511. The magnet member 521B is attached to the regulation 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 intersecting directions may be opposite.

  8 and 9, F1 indicates the rotation direction of the developing sleeve 511, that is, the moving direction of the developer when viewed from the magnet member 521B (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 this embodiment, θ = 15 °. A indicates the width (plate thickness) along the F1 direction of the regulating member 52B, and B indicates the width of the N-pole magnet body 521n along the direction inclined by θ (°) with respect to the axial direction L1. , C indicates the width of the S-pole magnet body 521s 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.

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

Example 4
With reference to FIG. 10 and FIG. 11, the structure of the developing roller 51 and the regulating member 52C in Embodiment 4 will be described in detail. FIG. 10 is a side view showing the configuration of the developing roller 51 and the regulating member 52C in the fourth embodiment, and FIG. In addition, since the structure of the developing roller 51 is the same as that of the first embodiment, a duplicate description is omitted.

  The restriction member 52A includes a restriction blade 522 and a magnet member 521C at a position facing the developing sleeve 511. The magnet member 521C is attached to the regulation 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 521 </ b> C includes a magnet body 521 b that is disposed along a direction that obliquely intersects axial direction L <b> 1. The intersecting directions may be opposite. In this embodiment, the magnet body 521b and the non-magnetic body 521a are alternately and repeatedly arranged along the axial direction L1. Further, the magnet bodies 521b are arranged in a zigzag with the inclination angles alternately reversed. In this embodiment, aluminum, stainless steel, or the like is used for the regulating blade 522 and the nonmagnetic material 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 when viewed from the magnet member 521C (regulating member 52C), and θ (°) indicates the axial direction L1. And the crossing angle with the direction in which the magnet body 521b is arranged. In this embodiment, θ = 15 °. A indicates the width (plate thickness) along the F1 direction of the regulating member 52A, 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.

  Also with the developing roller 51 and the regulating member 52C having the above-described configuration, the same operational effects 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 shows a top view showing the configuration of the regulating member 52X in Comparative Example 1, FIG. 13 shows the configuration of the developing roller 51 and the regulating member 52Y in Comparative Example 2 as a side view, and FIG. FIG. 7 shows a look-up view showing the configuration of the regulating member 52Y. In Comparative Examples 1 and 2 as well, the configuration of the developing roller 51 is the same as that in the first embodiment, and thus a duplicate description is omitted.

  In the regulating member 52X in Comparative Example 1 shown in FIG. 12, as shown in Example 1-4 above, the regulating member 52X is formed of aluminum at a position facing the developing sleeve 511 without including a magnet member. It is a thing. On the other hand, as shown in FIGS. 13 and 14, the restriction member 52 </ b> Y in the comparative example 2 includes a restriction blade 522 and a magnet member 521 at a position facing the developing sleeve 511. The magnet member 521 in the comparative example 2 has the magnet member arranged on the entire surface.

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

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

  This evaluation was performed in a state where the amount of developer to be filled was reduced by 40 g from the 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.

  The evaluation of screw unevenness in the longitudinal direction was confirmed visually. Those that can be visually confirmed and are of an NG level in quality are “F (failed)”, those that can be visually confirmed are “C (acceptable)”, and those that cannot be visually confirmed are “B (good)”.

  The evaluation of the image is based on the uneven density of the image, and the color difference ΔE between the dark portion and the light portion is calculated from the measurement result of the measure meter, and the reference shown in FIG. 16 is provided. “A (excellent)” is a color difference ΔE <1, “B (good)” is 1 ≦ color difference Δ <2, “C (good)” is 2 ≦ color difference Δ <3, and “F (fail)” Was evaluated as 3 ≦ color difference Δ.

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

  As shown in FIG. 17, since the sensitivity to the gap of the developer conveyance amount is low, even if the gap between the developing roller 51 and the regulating member changes in the longitudinal direction due to the curving of the regulating member, the developer carrying amount hardly changes and the image is defective. It was confirmed that it was suppressed. Example 3 was the most effective. In Example 3, since the N-pole magnet bodies 521n and the S-pole magnet bodies 521s are alternately arranged, it is considered that the lines of magnetic force tend to concentrate 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, the evaluation of screw unevenness occurs when the intersection angle between the axial direction L1 and the direction in which the magnet body 521b is arranged is 15 ° (165 ° when the inclination is opposite). It was confirmed that “B” and the image evaluation were “A” as best.

  Furthermore, from the evaluation results of FIG. 18, it was confirmed that the inclination angle θ is preferably 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 shortened, so the effect of suppressing screw unevenness is small. Become.

  Further, in each of the above embodiments, with reference to FIG. 19, when the first embodiment is described as a representative example, the plate thickness of the magnet member is Amm, the width of the magnet body is Bmm, and the width of the non-magnetic body is When the crossing angle between Cmm, the axial direction L1 and the direction in which the magnet body 521b is disposed is θ °, the relationship of A> B / cos θ may be satisfied. Furthermore, A> C / cos θ should be satisfied. That is, when viewed along the moving direction (F1) of the developing sleeve, the developer may pass through both the part where the one magnetic body exists and the part other than the one magnetic body.

  As a result, 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 the conveyance unevenness in the longitudinal direction due to the magnetic pole pattern.

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

  As a result, the screw uneven developer formed by the supply screw 53 can be moved from the peak portion to the valley portion, and the occurrence of screw unevenness in the developer can be more effectively eliminated.

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

  It should be considered that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. 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.

  DESCRIPTION OF SYMBOLS 1 Photoconductor, 2 Cleaning apparatus, 3 Charging means, 4 Writing apparatus, 5 Developing apparatus, 6 Recording material, 51 Developing roller, 52 Restriction member, 52A Restriction member, 52B Restriction 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 (7)

A developer supply mechanism for supplying the developer;
A developer carrier including a cylindrical development sleeve that carries the developer supplied from the developer supply mechanism and conveys the developer in a rotation direction;
A regulating member disposed opposite to the developing sleeve at a predetermined interval and extending along an axial direction of the developing sleeve;
With
A magnet member is disposed at a position of the regulating member facing the developing sleeve,
The developing device, wherein the magnet member includes a magnet body arranged along a direction obliquely intersecting the axial direction.   The developing device according to claim 1, wherein the magnet member is configured such that the magnet body and the non-magnetic body are alternately and repeatedly disposed along the axial direction.   The developing device according to claim 1, wherein the magnet member includes the magnet body and the magnetic member that are alternately and repeatedly disposed along the axial direction.   The developing device according to claim 1, wherein the magnet member includes the N-pole magnet body and the S-pole magnet body that are alternately and repeatedly arranged.   When viewed along the moving direction of the developing sleeve, the plurality of magnet bodies are arranged so as to pass through both the one magnet body and the one portion other than the one magnetic body in the magnet member. The developing device according to any one of claims 1 to 4. The developer supply mechanism includes a supply screw for supplying developer to the developing sleeve,
The thickness of the magnet member is A (mm), the width of the magnet body is B (mm), the crossing angle between the axial direction and the direction in which the magnet body is arranged is θ (°), the screw of the supply screw 6. The developing device according to claim 1, wherein when the pitch is D (mm), a relationship of A / tan θ> D is satisfied.   An image forming apparatus comprising the developing device according to claim 1.