JP4726530B2 - DEVELOPING DEVICE HAVING MAGNETIC SEAL AND IMAGE FORMING DEVICE HAVING THE DEVELOPING DEVICE - Google Patents

Description

  The present invention relates to a developing device and an image forming apparatus such as a printer including the developing device, and more particularly to a scraping member for removing the developer attached to a developer carrying member of the developing device.

  In image forming apparatuses such as copiers, printers, and fax machines, a powder developer (hereinafter referred to as toner) is mainly used, and an electrostatic latent image formed on an image carrier such as a photosensitive drum is formed with toner. A general process is to perform a fixing process after visualizing and transferring the toner image onto a recording medium.

  FIG. 5 shows a schematic configuration of a conventional image forming apparatus (for example, a printer) using a developing device. The image forming apparatus 100 includes at least a photosensitive drum 41, a charging unit 42, an image writing unit (laser scan unit) 43, a developing device 21, a toner storage unit 44, a transfer unit 45, a cleaning unit 46, a sheet storage unit 51, and a conveyance. The unit 52 includes a fixing unit 53, and a paper discharge unit 54.

  The photosensitive drum 41 is formed, for example, by laminating a photosensitive layer on an aluminum drum, and the charging unit 42 charges the surface. Then, an electrostatic latent image in which charging is attenuated is formed on the surface that has received a laser beam from an image writing unit 43 described later. The photosensitive layer is not particularly limited, but for example, amorphous silicon (a-Si) having excellent durability is preferable.

  The charging unit (charging charger) 42 charges the surface of the photosensitive drum 41 by discharging (for example, corona discharge). For example, the charging unit 42 has a thin wire or the like, and uses this as an electrode to discharge when a high voltage is applied.

  The image writing unit (LSU) 43 irradiates the photosensitive drum 41 with a light beam (for example, a laser beam) based on the image data, and forms an electrostatic latent image on the photosensitive drum 41. The image data is transmitted from a personal computer (PC) (not shown).

  The developing device 21 attaches toner to the electrostatic latent image on the photosensitive drum 41 to form a toner image. Examples of the developer accommodated in the developing device 21 include a two-component developer composed of toner and a carrier and a one-component developer composed only of toner. Details of the developing device 21 will be described later.

  The toner storage unit (hopper) 44 supplies the toner to the developing device 21 and stores the toner when the toner in the developing device 21 becomes insufficient.

  The transfer unit 45 transfers the toner image formed on the surface of the photoconductive drum 41 to the conveyed sheet without disturbing the toner image.

  The cleaning unit 46 removes the toner (residual toner) remaining on the surface of the photosensitive drum 41 after the toner image is transferred (transferred) to the sheet. For example, a blade material that makes line contact with the longitudinal direction of the photosensitive drum 41 may be used.

  The sheet storage unit 51 stores a sheet (paper, OHP, etc.) on which an image (toner image) is finally printed, and sends the sheet to the transport unit 52.

  The conveyance unit 52 is a sheet path from the sheet storage unit 51 to the paper discharge unit 54, and the fixing unit 53 is a toner image transferred to the sheet, which is a stable permanent image. By applying this energy, the toner image in the powder state is melted. The paper discharge unit 54 accommodates a sheet that has passed through the fixing unit 53, that is, a sheet on which a permanent image is printed.

  In the image forming apparatus 100 configured as described above, when image data is received from, for example, an external device (such as a PC), the LSU 43 irradiates the photosensitive drum 41 with a laser beam (light beam), whereby the image data is converted into the image data. An electrostatic latent image based thereon is formed on the surface of the photosensitive drum 41. Thereafter, the developing device 21 attaches toner to the electrostatic latent image (forms a toner image), and the transfer unit 45 transfers the toner image to the sheet. Next, the fixing unit 53 applies heat or the like to the sheet on which the toner image has been transferred to form a permanent image.

  Next, the device configuration of the developing device 21 will be described. FIG. 11 is a side sectional view showing the vicinity of the developing device 21 of the conventional image forming apparatus 100. The developing device 21 is installed at a position adjacent to the photosensitive drum 41. The developing device 21 includes at least a developer carrier 22 for supplying toner to the photosensitive drum 41. In the image forming process, an electrostatic latent image is formed on the photosensitive drum 41 by a laser beam from the LSU 43 based on the document image data. Subsequently, the developer carrying member 22 of the developing device 21 attaches toner to the electrostatic latent image on the photosensitive drum 41, whereby a toner image is formed on the photosensitive drum 41.

  The toner is supplied to the developer carrier 22 from the toner storage unit 44. Of the toner used at the time of image formation, the remaining toner that has not been fixed to the image-formed sheet is stored in a waste developer storage container (not shown).

  The developing device 21 uses a developing device 21a using a contact charging type layer regulating member and a non-contact charging type layer regulating member as a layer regulating member for regulating the amount of toner on the surface of the developer carrier 22. It can be classified into the developing device 21b. The developing device 21a regulates the amount of toner adhering on the developer carrier 22 using the frictional force and magnetic force of the layer regulating member. The developing device 21b regulates the amount of toner that adheres to the developer carrier 22 using the magnetic force of the layer regulating member.

  The configuration of the developing device 21a using the contact charging method as the layer regulating member will be described with reference to FIG. FIG. 6 is a partial view showing a part of a conventional developing device 21a. FIG. 6A is a partial plan view when a part of the developing device 21a is viewed from above. FIG. 6B is a side cross-sectional view of the developing device 21a shown in FIG. The developing device 21a includes at least a developer carrier 22, a magnetic seal (magnetic seal member) 23, a scraping member 24, a layer regulating member (developer carrying amount regulating member) 25, and a layer regulating member support 26. Yes.

  The developer carrying member 22 supplies toner to the photosensitive layer of the photosensitive drum 41 by rotating in accordance with the rotation of the photosensitive drum 41 (see FIG. 5). In addition, a magnetic field generating member (not shown) made of a permanent magnet facing the tip of a layer regulating member 25 described later is built in the inner surface of the developer carrier 22. Using the magnetic force of the magnetic field generating member, the toner is adhered (carried) to the surface of the developer carrier 22 to form a toner thin layer.

  The magnetic seal 23 is a magnetic body disposed at a certain distance (about 0.1 mm to 0.7 mm) with respect to the outer peripheral surface of the developer carrier 22 at the axial end of the developer carrier 22. It is a sealing member. The magnetic seal 23 is magnetized on the surface facing the developer carrier 22, and forms a concentrated magnetic field with the developer carrier 22. As a result, it is possible to prevent the toner from leaking outside from the developing device inner surface 61 described later.

  The scraping member 24 is a member provided on the downstream side in the rotation direction from the magnetic seal section (the space in which the magnetic seal 23 and the developer carrier 22 form a concentrated magnetic field). The scraping member 24 scrapes off the toner adhering to the developer carrier 22 in the magnetic seal section, and moves the scraped toner to the developer transport area of the developer carrier 22. Further, the contact surface of the scraping member 24 with respect to the developer carrier 22 is made larger than the lateral width of the magnetic seal 23. Therefore, the toner adhering to the outer side in the axial direction than the magnetic seal section can be scraped off.

  The layer regulating member 25 is for regulating the amount of toner supplied to the photosensitive drum 41 by the developer carrier 22, and for example, a coated elastic material or the like is used as the material. Specifically, a magnetic field is generated between the developer carrier 22 and the layer regulating member 25 by a magnetic field generating member (not shown), and the distance between the developer carrier 22 and the layer regulating member 25 and the strength of the magnetic field are determined. Is used to strictly regulate the amount of toner adhering to the developer carrier 22. As a result, a thin toner layer of several tens of microns can be formed on the surface of the developer carrying member 22.

  The layer restricting member support 26 is a member for attaching the layer restricting member 25, and has a role of fixing the layer restricting member 25 so as to restrict the toner amount by contacting the developer carrying member 22.

  The positional relationship between the above members will be described with reference to FIGS. FIG. 4 is a partial view of the vicinity of the developer carrying member 22 of the developing device 21a as viewed from the direction of the photosensitive drum 41. As shown in FIG. 4, the layer regulating member 25 is positioned above the axial center of the developer carrier 22. The magnetic seal 23 is present at the end in the axial direction from the layer regulating member 25. In the magnetic seal section formed by the magnetic seal 23, the scattered toner is adhered to the surface of the developer carrying member 22 by the magnetic restraining force so as not to leak to the outside.

  As shown to (a) of FIG. 6, the scraping member 24 is located in the axial direction edge part (downward direction in FIG. 6 (a)) rather than the layer control member 25. FIG. Further, the scraping member 24 has a structure having a wider width in the axial direction than the magnetic seal 23 so that the toner can be scraped off at the position of the end portion in the axial direction further than the magnetic seal 23. Yes.

  A process of scraping off the toner adhering to the end portion of the developer carrier 22 in the developing device 21a having the above configuration will be described with reference to FIG. FIG. 7 is a partial plan view showing the flow of toner when the surface of the developer carrying member 22 is viewed from above. Note that the upper part of FIG. 7 shows the axial center of the developer carrier 22. A developing device inner surface 61 and a layer restricting portion 62 exist upstream of the developer carrying member 22 in the rotation direction (left side in FIG. 7).

  The developing device inner surface 61 is a part of the surface portion of the developer carrier 22, and the developer carrier 22 is a portion that receives supply of toner from a developer storage portion (not shown). The toner adhering to the developer carrier 22 in this region is regulated in amount by the layer regulating member 25 and conveyed to the outside of the developer container (in the direction downstream of the developer carrier 22). The layer regulating portion 62 is a part of the surface portion of the developer carrying body 22, and the layer regulating member 25 uses a physical or electromagnetic force on the developer carrying body 22 to develop the developer carrying body. 22 is a portion that regulates the amount of toner adhering to 22.

  An arrow β indicates the flow of toner adhering to the developer carrier 22. This toner is removed by the scraping member 24 installed downstream of the magnetic seal section, and is moved in the direction of the arrow γ (developer transport area). The scraped toner is conveyed downstream without contacting the developing device inner surface 61 and the layer regulating portion 62. For this reason, the toner does not stay or flow backward due to contact with the developing device inner surface 61 or the layer regulating portion 62. As a result, the scraped toner can be reused in the developer transport area.

  However, in the configuration as described above, the contact surface of the scraping member 24 is on the downstream side in the rotation direction with respect to the developing device inner surface 61 and the layer regulating portion 62, as in the developing device 21a of the contact charging system shown in FIG. Only possible in some cases. On the other hand, the contact surface of the scraping member 24 is upstream of the developing device inner surface 61 or the layer regulating portion 62 in the rotational direction, as in the developing device 21b using the non-contact charging method shown in FIGS. If the toner is on the side, the toner scraped off by the scraping member 24 cannot return to the developer transport area of the developer carrier 22.

  The developing device 21b will be described with reference to FIG. FIG. 8 is a partial view showing a part of a conventional developing device 21b. FIG. 8A is a partial plan view when a part of the developing device 21b is viewed from above. FIG. 8B is a side cross-sectional view of the developing device 21b shown in FIG. The developing device 21b includes at least a developer carrier 22, a magnetic seal 23, a scraping member 24, and a layer regulating member 25.

  Since the developer carrier 22, the magnetic seal 23, and the scraping member 24 are the same as the members of the developing device 21a, description thereof is omitted here. The layer regulating member 25 regulates the thickness of the toner thin layer on the surface of the developer carrier 22. The difference from the layer regulating member 25 of the developing device 21a is that the toner thin layer is regulated only by a magnetic force without being physically in contact with the developer carrier 22. Accordingly, the layer regulating member 25 of the developing device 21b does not require the layer regulating member support 26 unlike the developing device 21a, and is configured to be mounted on the main body (not shown) of the developing device 21. Further, due to the difference in the structure of the layer regulating member 25, the position of the layer regulating unit 62 is different from the layer regulating unit 62 of the developing device 21a (below the layer regulating member 25).

  A process in which toner is scraped off in the developing device 21b having the above-described configuration will be described with reference to FIG. The arrow β in FIG. 9 indicates the flow of toner attached to the developer carrier 22. This toner is removed by the scraping member 24 installed downstream of the magnetic seal section, and tries to move in the direction of the arrow γ (developer transport region). However, at the tip of the arrow γ, the developing device inner surface 61 and the layer restricting portion 62 exist. For this reason, the toner existing on the inner surface 61 of the developing device or the layer regulating portion 62 becomes a wall and refuses to flow in the toner, and the toner flows backward in the direction of the arrow γ ′ (end in the axial direction). As a result, there arises a problem that the scraped toner accumulates at the axial end portion or leaks to the outside.

  As a method for avoiding the above problem, a method is conceivable in which the contact surface of the scraping member 24 is arranged on the downstream side of the developing device inner surface 61 and the layer regulating portion 62. By arranging as described above, the toner existing on the developing device inner surface 61 or the layer regulating portion 62 does not become a wall, and the scraped toner does not flow backward. As an invention adopting this method, in Patent Document 1, an image forming apparatus including a developing device in which the scraping member 24 is arranged on the downstream side in the rotation direction from the developing device inner surface 61 and the layer regulating portion 62 and on the surface facing the photosensitive drum 41 is disclosed. An apparatus is disclosed.

  In Patent Document 1, as shown in FIG. 10, a scraping member 24 is provided downstream of the developing device inner surface 61 and the layer regulating portion 62 in the rotational direction and on the surface facing the photosensitive drum 41. The scraping member 24 abuts in the forward direction with respect to the rotation direction of the developer carrier 22, scrapes the toner adhering to the developer carrier 22 in the magnetic seal section, and moves the toner to the developer transport region. Have a job. Thus, Patent Document 1 discloses a method for preventing leakage of the developer flowing out from the magnetic seal section.

  However, in the above configuration, the scraping member 24 bends in the driven direction with respect to the rotation direction of the photosensitive drum 41, so that the scraping performance cannot be sufficiently obtained. Conversely, the adhered toner is not scraped off but rather pressed down, resulting in an increase in the toner adhesion amount. As a method for avoiding this, for example, it is assumed that the scraping member 24 is installed not in the forward direction but in the reverse direction with respect to the rotation direction. In this case, although sufficient scraping performance may be obtained, the scraped toner scatters from the developer carrier 22 and adheres to the photosensitive drum 41, causing image defects such as black spots and fogging. The problem occurs.

  In the above configuration, as shown in FIG. 10, the developer carrier 22 is at θ ′ in FIG. 10 until the surface of the developer carrier 22 that has passed through the layer restricting portion 62 reaches the scraping member 24. Must rotate by the indicated angle. However, since θ ′ has an angle of 90 ° or more, the toner adhering to the end portion in the axial direction of the developer carrier 22 may be scattered while rotating.

As described above, in the developing device 21b using the conventional non-contact charging type layer regulating member 25 and the conventional scraping member 24, some trouble occurs regardless of where the scraping member 24 is arranged. There was a problem that.
JP 9-218578 A

  In view of the above problems, the present invention includes a scraping member that does not depend on the configuration of the layer regulating member (the layer regulating member can be adopted by either a contact charging method or a non-contact charging method), and can be implemented at low cost. And a developing device that can reliably remove the toner adhering to the edge of the developer carrying member by the scraping member, and the removed toner does not leak and cause trouble in image formation, and an image including the developing device. An object is to provide a forming apparatus.

The developing device of the present invention is
A developer storage section for storing the developer;
A developer carrying member for carrying the developer supplied from the developer storage unit;
A developer carrying amount regulating member that regulates the amount of developer carried on the surface of the developer carrying body;
A magnetic seal member that adheres the developer leaking outside from the axial end of the developer carrying member to the axial end of the developer carrying member by magnetic force;
A scraping member for removing the developer attached to the axial end of the developer carrier;
A scraping member support for fixing the scraping member in contact with the surface of the developer carrying member;
In a developing device comprising:
The scraping member is installed downstream of the developer carrying amount regulating member in the rotation direction of the developer carrying body.

  According to this configuration, the scraping member attached to the scraping member support is the axial end portion of the developer carrier, the downstream side in the rotation direction of the developer carrier relative to the layer regulating member, and the developer carrier. Is installed at a position in contact with the upstream portion in the rotational direction of the portion exposed to the outside of the developing device, and the scraping member is in contact with the surface of the developer carrying member and can be rubbed. . Therefore, the toner adhering to the axial end portion of the developer carrying member is removed by the scraping member in the downstream direction of the layer regulating member.

The developing device of the present invention is
The scraping member support has a shape having substantially the same curvature as the developer carrying member.

  According to this configuration, when a scraping member is mounted on the support, the pressure-contact direction of the scraping member with respect to the developer carrying member is the center direction (normal direction) of the developer carrying member, and is in contact with the developer carrying member. Apply a constant pressure in the plane. For this reason, the surface of the scraping member and the surface of the developer carrier are in contact with each other without any gap, and the toner adhering to the developer carrier is efficiently removed.

The developing device of the present invention is
The scraping member is formed of an elastic material;
An end surface of the scraping member is inclined from the outside in the axial direction to the inside with respect to the rotation direction of the developer carrying member in order to convey the scraped toner to the center in the axial direction;
It is characterized by.

  According to this configuration, the scraping member is made of an elastic material made of, for example, urethane, synthetic rubber, synthetic fiber, or the like, and the toner adhered to the axial end portion of the developer carrier by sliding the developer carrier. Is removed. Further, according to this configuration, a part of the scraping member, for example, one surface facing the rotation direction of the developer carrying member is cut in an oblique direction. For this reason, the scraped toner is moved to the developer transport region (axial center) using the inclined processing portion.

The developing device of the present invention is
The scraping member support is fixed to the developer carrying amount regulation member.

  According to this configuration, for example, the scraping member support is attached to a part of the layer regulating member (developer carrying amount regulation regulating member). Therefore, the scraping member support can be fixed without newly providing a contact portion unique to the scraping member support.

The developing device of the present invention is
The scraping member support is integrally formed with the developer storage portion.

  According to this configuration, for example, the scraping member support is integrated with the housing (developer storage unit) of the developing device. Therefore, the scraping member support can be added to the apparatus by changing the structure of the housing without newly providing a contact portion unique to the scraping member support.

According to the first configuration of the present invention,
When the scraping member is viewed from the axial end of the developer carrier and the rotation direction of the developer carrier, the developer carrier is exposed to the outside of the developing device and downstream from the layer regulating member. Since it is provided in the position which contacts the upstream part in the part which has, it can prescribe | regulate the character and raw material of a scraping member irrespective of the kind and shape of a layer control member.
In addition, since the scraped toner does not compete with the toner present in the layer regulating member or the developing container, the scraped toner is caused to flow backward by the toner present in the member, and there is no risk of leaking outside. .
Further, since the scraping member is installed immediately downstream of the layer regulating member as viewed from the rotation direction of the developer carrier, the surface where the toner is not removed by the scraping member is outside (downstream from the layer regulating member). Therefore, there is no possibility that the toner is scattered outside from the exposed surface.
From the above, according to the first configuration of the present invention, the toner adhering to the axial end of the developer carrier can be reliably removed regardless of the type and shape of the layer regulating member.

According to the second configuration of the present invention,
Since the scraping member attached to the scraping member support has the same curvature as that of the developer carrying member, it can contact the surface of the developer carrying member with a uniform pressure. Therefore, there is no difference in the scraping performance locally, the uniform scraping performance can be maintained over the entire contact surface, and the adhered toner can be more reliably removed.

According to the third configuration of the present invention,
The scraping member is made of an elastic material made of, for example, urethane, synthetic rubber, synthetic fiber, etc., so even if it is attached to a scraping part support with a curvature as shown in the second configuration, it is easy The member can be processed. Further, since it is an elastic material, it does not damage the surface of the developer carrying member even if it is rubbed.

  Further, according to this configuration, a part of the scraping member, for example, a portion facing the developer carrying member rotating direction is cut in an oblique direction, whereby the scraped toner is moved in a predetermined direction (for example, the center in the axial direction). The scraped toner can be reused by being guided and moved to the developer transport area.

According to the fourth configuration of the present invention,
For example, since the scraping member support is attached to the layer forming agent regulating portion, it is not necessary to newly provide a contact portion unique to the scraping member, and the member can be saved. Furthermore, since it is not necessary to make changes to other existing members, the present invention can be implemented at a minimum cost.

According to the fifth configuration of the present invention,
For example, since the scraping member support is integrally formed with the housing, there is no need to newly provide a contact portion unique to the scraping member, and the member can be saved. Since it is not necessary to change other existing members, the present invention can be implemented at a minimum cost.

The image forming apparatus of the present invention will be described below with reference to the drawings.
[Embodiment]
<1. Overall configuration of the device>
Here, the configuration of the printing apparatus 21 according to the present invention will be described with reference to FIGS. 1 and 4. In addition, about the part which is common in FIGS. 6-9 of a prior art example, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIGS. 1 and 4, the printing apparatus 21 of the present invention includes at least a developer carrier 22, a magnetic seal 23, a layer regulating member 25, a scraping member 28, a scraping member support 29, and a housing 30. It is configured to include. In the present embodiment, description is made using a printing apparatus in which the layer regulating member 25 is provided with a non-contact charging method. However, the present invention is similarly applied to a printing apparatus in which the layer regulating member 25 is provided with a contact charging method. It can be implemented.

  The scraping member 28 is a member made of an elastic material (for example, urethane, synthetic rubber, etc.) provided near the outlet downstream of the magnetic seal section. The scraping member 28 scrapes the toner adhering to the developer carrier 22 in the magnetic seal section and the toner adhering to the end in the axial direction further than the magnetic seal section, and again returns to the developer transport region of the developer carrier 22. This is a member that prevents the toner from leaking to the outside or the surface facing the photosensitive drum 41 by returning to the front. Details will be described later.

  The scraping member support 29 is a member for mounting the scraping member 28 and fixing it to a predetermined position. The scraping member support 29 has a similar curvature with respect to the developer carrier 22. The scraping member support 29 is attached to the layer regulating member 25 or is integrated with a housing 30 described later.

  The housing 30 is a main body of the developing device 21 and has a role of storing a developer. The housing 30 can be integrated with the scraping member support 29.

<2. Toner removal method using scraping member>
Next, a method for removing the adhered toner by the scraping member 28 in the configuration of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the scraping member 28 of the present invention is attached to a scraping member support 29 having the same curvature with respect to the developer carrier 22. For this reason, the scraping member 28 comes into contact with the developer carrier 22 with the same curvature. 1 represents an angle of 20 ° to 30 °, and the scraping member 28 rubs the surface of the developer carrying member 22 in this range.

  FIG. 2A is a side cross-sectional view of the vicinity of the scraping member 28 as viewed from the side. As shown in FIG. 2A, the pressure contact direction of the scraping member 28 is the central direction (normal direction) of the developer carrier 22. In the structure as described above, the scraping member 28 rubs against the developer carrier 22 by applying a constant pressure within the contact surface, thereby removing the toner on the developer carrier 22.

  FIG. 3 is a perspective view showing the periphery of the developer carrier 22. The scraping member 28 is fixed by sticking the scraping member 28 to the sticking surface 29 a of the scraping member support 29. In the drawing, an arrow α indicates an axial center portion (developer transport region), and an arrow α ′ indicates an axial end portion. In addition, arrows β, γ, and γ ′ in the figure indicate the flow of toner attached to the developer carrier 22.

  As shown in FIG. 3, the scraping member 28 of this embodiment is shaped so that the end surface on the upstream side in the rotational direction is inclined from the axial end to the axial central portion. As a result, the adhering toner conveyed in the direction indicated by the arrow β is scraped off by the scraping member 28 and then flows in the direction of the arrow γ (the central portion in the axial direction). At the same time, in order to prevent the toner from flowing in the direction of the arrow γ ′ (the end in the axial direction), the scraped toner can be surely moved to the toner layer (developer transport area) on the surface of the developer carrier. it can.

  In the present embodiment, the scraping member support 29 is fixed to the layer regulating member 25 and scrapes off the toner downstream of the layer regulating member 25 in the rotation direction. For this reason, the non-developer transport area where the toner is adhered is not exposed on the surface facing the photosensitive drum 41, and the scattering of the toner can be prevented. Note that the same effect can be obtained when the scraping member 28 is not fixed to the layer regulating member 25 as shown in FIG.

  Note that the scraping member 28 and the scraping member support 29 do not necessarily have a curved surface having the same ratio as that of the developer carrier 22 as in this embodiment, but in that case, as shown in FIG. Thus, the pressure in the elastic member contact surface is not uniform. For this reason, the toner scraping performance varies within the elastic member contact surface, and sufficient and efficient toner removal cannot be performed. From the above, it is more preferable that the scraping member 28 and the scraping member support 29 have curved surfaces with the same rate as the developer carrier 22.

<3. Various features of the present invention>
According to this embodiment,
The scraping member 28 is exposed to the axial end of the developer carrier 22, downstream of the layer regulating member 25 in the rotation direction of the developer carrier 22, and the developer carrier 22 is exposed to the outside of the developing device 21. The position which contacts the rotation direction upstream part among the parts which are carrying out is provided. For this reason, the character and material of the scraping member 28 can be defined regardless of the type and shape of the layer regulating member 25.

According to this embodiment,
When the scraped toner is moved to the developer conveying surface, the toner existing on the developing device inner surface 61 or the layer regulating portion 62 does not become a wall. Therefore, the toner scraped off can be moved into the developing device 21 reliably.

According to this embodiment,
Since the scraping member is installed in the vicinity of the layer regulating member, the surface where the toner is not removed by the scraping member is not exposed to the surface facing the photosensitive drum 41 (downstream side from the layer regulating member). Therefore, there is no possibility that the toner is scattered from the exposed surface to the outside.

According to this embodiment,
Since the scraping member 28 is installed outside the developing device 21, the configuration of the scraping member 28 can be easily changed. For example, when adjusting the scraping performance of the scraping member 28 according to the adhesion force of the toner to the developer carrying member 22, according to the configuration of the present invention, by changing the elastic member constituting the scraping member 28, It can respond flexibly. The adhesion force of the toner to the developer carrying member 22 varies depending on the material of the developer carrying member 22, the surface roughness, the magnetic force of the magnetic seal 23, the toner physical properties, and the like.

According to this embodiment,
Unlike the conventional configuration shown in FIG. 10, the scraping member 28 of the present invention has the same curvature as that of the developer carrier 22, so that the entire surface of the developer carrier 22 is removed. A uniform contact can be made across. As a result, a constant pressure can be applied over the whole, and the local scraping performance is prevented from being lowered. Further, the toner can be surely removed without pressing the developer against the surface of the developer carrying member 22 to fix the toner.

According to this embodiment,
Since the scraping member 28 of the present invention is made of an elastic material made of, for example, urethane, synthetic rubber, synthetic fiber, etc., the member is easily processed even when the scraping member 28 is fixed to the scraping portion support 29 having a curvature. be able to. Further, even if the developer carrying member 22 is rubbed, there is no risk of damaging the surface.

According to this embodiment,
Since the scraping member support 29 according to the present invention is mounted on the existing layer regulating member 25 or is integrally formed with the housing 30, each of the members other than the housing 30 is used in the implementation of the present invention. There is no need to make changes. Therefore, it is possible to implement the present invention at a low cost.

[Other embodiments]
The present invention has been described with reference to the preferred embodiments and examples. However, the present invention is not necessarily limited to the above embodiments and examples, and various modifications may be made within the scope of the technical idea. Can be implemented.

  For example, even if the structure of the developing device that realizes the functions of the above-described embodiments is used to improve the efficiency of toner removal in the non-developer transport area in an image forming apparatus other than a printer, the same effect is achieved. Needless to say.

  In this case, the developing device itself attached to the image forming apparatus realizes the functions of the above-described embodiments, and the image forming apparatus equipped with the developing device constitutes the present invention.

  In addition, as an image forming apparatus provided with the developing device in the present invention, for example, a printer, a copier, a facsimile, and the like are assumed.

FIG. 4 is a side cross-sectional view showing the vicinity of a developer carrier in the developing device of the present invention. It is side surface sectional drawing which showed the shape of the scraping member in the image development apparatus of this invention. It is a perspective view showing a developer carrying member, a scraping member, and a scraping member support of the present invention. It is the schematic which showed the developer carrier in the image development apparatus of this invention. It is a whole block diagram of the conventional image forming apparatus. FIG. 6 is a side sectional view and a partial plan view showing the vicinity of a developer carrier in a conventional contact charging type developing device. FIG. 6 is a partial plan view showing the vicinity of a developer carrier in a conventional contact charging type developing device. FIG. 6 is a side sectional view and a partial plan view showing the vicinity of a developer carrier in a conventional non-contact charging type developing device. FIG. 10 is a partial plan view showing the vicinity of a developer carrier in a conventional non-contact charging type developing device. 6 is a side cross-sectional view showing the vicinity of a developer carrier in a non-contact charging type developing device of Patent Document 1. FIG. It is side surface sectional drawing which showed the structure of the conventional image development apparatus.

Explanation of symbols

21 Developing Device 22 Developer Carrier 23 Magnetic Seal (Magnetic Seal Member)
24 scraping member 25 layer regulating member (developer carrying amount regulating member)
26 Layer regulating member support 28 Scraping member 29 Scraping member support 30 Housing (developer storage part)
41 Photosensitive drum

Claims (6)

A developer storage section for storing the developer;
A developer carrier that carries the developer supplied from the developer storage unit and supplies the developer to the photosensitive drum; and
A developer carrying amount regulating member that regulates the amount of developer carried on the surface of the developer carrying body;
A magnetic seal member that adheres the developer leaking outside from the axial end of the developer carrying member to the axial end of the developer carrying member by magnetic force;
A scraping member that removes the developer attached to the axial end portion of the developer carrying member and conveys it to the axial center of the developer carrying member;
A scraping member support for fixing the scraping member in contact with the surface of the developer carrying member;
In a developing device comprising:
The position where the scraping member comes into contact with the surface of the developer carrying member is downstream of the portion where the developer carrying amount is regulated by the developer carrying amount regulating member in the rotation direction of the developer carrying member. together, Ri upstream der than a position where the developer carrying member and the photosensitive drum is closest,
The scraping member is formed of an elastic material;
The developing device according to claim 1, wherein the scraping member is fixed to the scraping member support to have a shape having substantially the same curvature as the developer carrying member . The end surface of the scraping member is inclined from the outside in the axial direction to the inside with respect to the rotation direction of the developer carrying member in order to convey the scraped toner to the center in the axial direction. 2. The developing device according to 1. The developing device according to claim 1, wherein the scraping member support is fixed to the developer carrying amount regulating member. The developing device according to claim 1, wherein the scraping member support is integrally formed with the developer storage portion. The developing device according to claim 1, wherein the developer carrying amount regulating member is not in contact with the developer carrying member.   An image forming apparatus comprising the developing device according to claim 1.

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