JP6188461B2 - Spacing guarantee member, developing device, and process cartridge - Google Patents

Description

  The present invention relates to a gap ensuring member used in an image forming apparatus, a developing device having the same, and a process cartridge.

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

  2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image forming process, a spacer is provided at the end of a developing roller in order to maintain a constant distance and distance between a photosensitive drum (image carrier) and a developing roller (developer carrier). An interval guarantee member called “etc.” is provided.

The spacer is sandwiched between the photosensitive drum and the developing roller by an urging force such as a spring, and regulates a constant interval between the photosensitive drum and the developing roller.
The conventional spacer is supported so as to be rotatable with respect to the developing roller in addition to the one rotating itself according to the rotation of the developing roller and the photosensitive drum, but the spacer itself does not rotate (for example, Patent Document 1). ) Has been proposed.

Japanese Patent No. 3679665

  The object of the present invention is to further develop the prior art. In the configuration in which the interval ensuring member itself does not rotate, the intrusion of developer or the like is suppressed at the contact portion between the interval ensuring member and the image carrier. An object of the present invention is to suppress the variation in the distance between the image carrier and the developer carrier and suppress the occurrence of defective images.

  In order to achieve the above object, a typical configuration of the present invention is as follows.

In the interval ensuring member that maintains the distance between the image carrier on which the latent image is formed and the developer carrier that carries the developer,
A distance holding unit that holds the distance between the image carrier and the developer carrier by contacting the image carrier and the developer carrier;
A rotation prevention unit that prevents the spacing assurance member from moving in the rotation direction of the developer carrier;
In the rotation direction of the image carrier, the distance holding unit is disposed further upstream from the upstream end of the region in contact with the image carrier, and comes into contact with the image carrier by contacting the image carrier. A scraping part for scraping off the developer adhering to the image carrier;
It is characterized by providing.

  In the configuration in which the interval ensuring member itself does not rotate, the developer or the like is prevented from entering the contact portion between the interval ensuring member and the image carrier. In addition, the variation in the distance between the image carrier and the developer carrier can be suppressed, and the occurrence of defective images can be suppressed.

It is explanatory drawing which shows the structure of a spacer. 1 is a cross-sectional view illustrating a configuration of an image forming apparatus. It is sectional drawing of a process cartridge. It is explanatory drawing which shows the structure of a spacer from the viewpoint of 2 directions. It is explanatory drawing which shows the structure of a spacer. It is explanatory drawing which shows the structure of a spacer. It is explanatory drawing which shows the structure of a spacer from the viewpoint of 2 directions. It is explanatory drawing which shows two examples of the structure of a spacer. It is explanatory drawing which shows the structure of a spacer. It is explanatory drawing which shows the structure of a spacer.

Example 1
Hereinafter, exemplary embodiments of the first embodiment will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent. Further, the materials, shapes, etc. of the members once described in the following description are the same as those in the first description unless otherwise described.

  In the following description, the longitudinal direction of the process cartridge is the same direction as the longitudinal direction of the developing roller and the photosensitive drum. That is, the longitudinal direction is the central axis direction of the developing roller or the central axis direction of the photosensitive drum (the direction parallel to the direction in which the central axis (axis line) of the developing roller extends).

  Further, left and right are left or right when the recording medium is viewed from above according to the conveyance direction of the recording medium. Further, the upper surface of the process cartridge is a surface located above in a state where the process cartridge is mounted on the apparatus main body, and the lower surface is a surface located below.

(Overall description of electrophotographic image forming apparatus)
First, an overall configuration of an image forming apparatus that forms an image on a recording medium using an electrophotographic system will be schematically described with reference to FIG. FIG. 2 is a schematic cross-sectional view of an image forming apparatus equipped with a process cartridge according to the present embodiment. More specifically, FIG. 2 is a schematic cross-sectional view of a laser beam printer which is one form of the image forming apparatus.

  As shown in FIG. 2, an image forming apparatus (laser beam printer) A according to the present embodiment irradiates a drum-shaped photosensitive drum 7 with information light based on image information from an optical system 1 as an optical unit. Then, a latent image (electrostatic latent image) is formed on the photosensitive drum 7. This electrostatic latent image is developed with a developer (hereinafter referred to as “toner”) to form a toner image (developer image) on the photosensitive drum 7. That is, the photosensitive drum 7 is an image carrier that carries an image (latent image or toner image).

  In synchronism with the formation of the toner image on the photosensitive drum 7, the recording medium (for example, recording paper, OHP sheet, cloth, etc.) 2 is moved from the cassette 3a to the pickup roller 3b and a pressure contact member 3c that presses the recording medium. Separately feed each sheet. The fed recording medium 2 is conveyed along a conveyance guide 3f1 to a transfer portion T where the photosensitive drum 7 of the process cartridge B and the transfer roller 4 as a transfer unit face each other.

  The recording medium 2 conveyed to the transfer portion T is transferred with the toner image formed on the photosensitive drum 7 by the transfer roller 4 to which voltage is applied, and is conveyed to the fixing unit 5 along the conveyance guide 3f2. The fixing unit 5 includes a driving roller 5a and a heater 5b. The fixing unit 5 includes a fixing rotating body 5d formed of a cylindrical sheet rotatably supported by a supporting body 5c. The transferred toner image is fixed by applying pressure. The discharge roller 3d conveys the recording medium 2 on which the toner image is fixed, and discharges it to the discharge unit 6 through the reverse conveyance path.

  In this embodiment, the pickup means 3 (transport mechanism, transport device) 3 for transporting the recording medium 2 is constituted by the pickup roller 3b, the pressure contact member 3c, the discharge roller 3d, and the like.

(Process cartridge)
Next, the overall configuration of the process cartridge will be schematically described with reference to FIG. FIG. 3 is a schematic cross-sectional view of the process cartridge according to the present embodiment.

  As shown in FIG. 3, the process cartridge B includes a photosensitive drum 7 and at least one process means. Here, as the process means, for example, a charging means for charging the photosensitive drum 7, a developing means for developing the electrostatic latent image formed on the photosensitive drum 7, and a toner for cleaning the toner remaining on the photosensitive drum 7 are used. There are cleaning means and the like. The process cartridge B is a cartridge that can be attached to and detached from the main body of the image forming apparatus A.

  In the process cartridge B according to the present embodiment, the surface of the photosensitive drum 7 is made uniform by rotating the photosensitive drum 7 having a photosensitive layer in the direction of the arrow X2 and applying a voltage to the charging roller 8 as charging means. Is charged. Information light (light image) based on image information from the optical system 1 is exposed to the charged photosensitive drum 7 through the exposure opening 9b to form an electrostatic latent image on the surface of the photosensitive drum 7, The electrostatic latent image is developed by the developing unit 10. That is, the developing unit 10 is a developing device, and in this embodiment, the developing unit 10 is detachable from the apparatus main body of the image forming apparatus A as a part of the process cartridge B.

  The toner frame 14 of the developing unit 10 forms a toner storage chamber 10a, and the toner is stored inside the toner storage chamber 10a. The toner in the toner storage chamber 10 a is sent out to the development chamber 10 i by a developer conveying member (hereinafter referred to as “toner feeding member”) 10 b rotatably provided in the toner storage chamber 10 a and an elastic sheet 12. The elastic sheet 12 is disposed within the rotation region of the toner feeding member 10b and vibrates in contact with the toner feeding member 10b. By this vibration, the elastic sheet 12 functions to move the toner stored in the toner storage chamber 10a in a direction approaching the developing chamber 10i.

  The developing roller 10 disposed in the developing chamber 10i is a developing rotating body (developer carrying body) having a built-in fixed magnet 10c, and carries the developer on the surface thereof. The developing roller 10d is rotated in the direction of the arrow X1, and a toner layer is formed on the surface of the developing roller 10d by applying a triboelectric charge to the toner by the developing blade 10e. Thus, the toner carried on the surface of the developing roller 10d is transferred to the photosensitive drum 7 in accordance with the electrostatic latent image. As a result, a toner image is formed on the photosensitive drum 7, and the latent image formed on the photosensitive drum 7 is visualized.

  After the toner image is transferred to the recording medium 2 by applying a voltage having a polarity opposite to that of the toner image to the transfer roller 4, the toner remaining on the photosensitive drum 7 is scraped off by the cleaning blade 11a. At the same time, the toner written off by the cleaning blade 11a is scooped by the squeeze sheet 11b and collected in the removed toner storage portion 11c. Thus, the residual toner on the photosensitive drum 7 is removed by the cleaning means (cleaning blade 11a).

  The process cartridge B according to the present embodiment includes a drum unit 11a and a developing unit 10. The drum unit 11a rotatably supports the photosensitive drum 7 by a frame (drum frame 11d). A cleaning blade 11a and a charging roller 8 are further attached (incorporated) to the drum frame 11d. The developing unit 10 supports the developing roller 10d by the developing frame 10f1. The developing frame 10f1 forms a frame of the developing unit 10 together with the toner frame 14. A toner chamber 10a (developer housing portion) is formed mainly by the toner frame 14. The toner frame 14 includes a frame body 14a and a lid member 14b that joins the frame body 14a.

  The developing frame 10f1 includes arm portions 10q1 and 10q2 at both ends in the longitudinal direction. The arm portions 10q1 and 10q2 are formed with coupling holes 10p1 and 10p2 for rotatably supporting the developing unit 10 on the drum unit 11, respectively. By inserting the coupling portion of the drum unit 11 into the coupling holes 10p1 and 10p2, the developing unit 10 is rotatably supported with respect to the drum unit.

  With this configuration, the developing frame 10f1 can face the developing roller 10d in parallel with the photosensitive drum 7 at a predetermined interval. An interval ensuring member (hereinafter referred to as a “spacer”) 10 m is disposed at both ends of the developing roller 10 d. The spacer 10m maintains a distance and a distance between the developing roller 10d and the photosensitive drum 7.

(Spacer that keeps the distance between the developing roller and the photosensitive drum)
Next, the configuration of the spacer 10m that maintains the distance between the developing roller and the photosensitive drum will be described more specifically with reference to FIGS. 1 and 4 to 8. FIG. FIG. 4 is a diagram of the spacer 10m viewed from two viewpoints.

  As shown in FIGS. 1 and 4, the spacer 10m includes a developing roller contact surface 10m1 extending along the peripheral surface of the developing roller 10d, and a photosensitive drum contact surface 10m2 extending along the peripheral surface of the photosensitive drum 7. It has.

  FIG. 9 is a schematic diagram of a cross section of the developing roller 10d and the like (a cross section perpendicular to the axis of the developing roller 10d).

  The developing roller 10d and the photosensitive drum 7 rotate so as to move the circumferential surfaces of the developing roller 10d and the photosensitive drum 7 in the same direction. That is, the developing roller 10d and the photosensitive drum 7 are rotated so that both opposing surfaces are moved from above to below.

  The developing roller contact surface 10m1 and the photosensitive drum contact surface 10m2 are in contact with the developing roller 10d and the photosensitive drum 7, respectively, so that the distance between the developing roller 10d and the photosensitive drum 7 is kept constant. That is, the developing roller contact surface 10m1 and the photosensitive drum contact surface 10m2 serve as a distance holding unit that holds the distance between the developing roller 10d and the photosensitive drum 7.

  In particular, in this embodiment, the developing roller contact surface 10m1 has a curved surface shape (arc shape) bent along the peripheral surface of the developing roller 10m1. The developing roller contact surface 10m1 is in contact with the developing roller 10d from the upstream side to the downstream side of the line La in the rotation direction X1 of the developing roller 10d. Here, the line La is a straight line connecting the center of the developing roller 10 d and the center of the photosensitive drum 7.

  In other words, the developing roller contact surface 10m1 has at least the first developing roller rubbing portion (first developing side rubbing portion) 10p1u and the second developing roller rubbing portion (second developing side rubbing portion) when the developing roller 10d rotates. ) Rub with the developing roller 10d at two points of 10p1d. The first developing roller rubbing portion 10p1u rubs against the developing roller 10d on the upstream side in the rotation direction X1 of the developing roller 10d from the closest position between the developing roller 10d and the photosensitive drum 7 (from the line La). It is an area. The second developing roller rubbing portion 10p1d is an area that rubs against the developing roller 10d on the downstream side in the rotational direction X1 from the closest portion (from the line La). In this embodiment, the first developing roller rubbing portion 10p1u and the second developing roller rubbing portion 10p1d are on the same curved surface (developing roller contact surface 10m1), and the two rubbing portions (10p1u, 10p1d) are It is continuous. However, the two rubbing portions (10p1u, 10p1d) may not be connected, and there may be a gap between them.

  Similarly, the photosensitive drum contact surface 10 m 2 also has a curved surface shape (arc shape) bent along the peripheral surface of the photosensitive drum 7. Therefore, the photosensitive drum contact surface 10m2 is in contact with the photosensitive drum 7 from the upstream side to the downstream side of the line La in the rotation direction X2 of the photosensitive drum 7. In other words, the photosensitive drum contact surface 10m has at least the first drum rubbing portion (first image bearing side rubbing portion) 10p2u and the second drum rubbing portion (second image bearing side) when the photosensitive drum 7 rotates. (Rubbing part) Rubbing with the photosensitive drum 7 at two locations of 10p2d.

  The first drum rubbing portion 10p2u is a region that rubs against the developing roller 10d on the upstream side in the rotational direction X2 of the photosensitive drum 7 from the closest position between the developing roller 10d and the photosensitive drum 7 (from the line La). It is. The second drum rubbing portion 10p2d is an area that rubs against the photosensitive drum 7 on the downstream side in the rotation direction X2 from the closest portion (from the line La). In this embodiment, the first drum rubbing portion 10p2u and the second drum rubbing portion 10p2d are on the same curved surface (photosensitive drum contact surface 10m2), and the two rubbing portions (10p2u, 10p2d) are continuous. doing. However, the two rubbing portions (10p2u, 10p2d) may not be connected, and there may be a gap between them.

  The spacer 10m has the above-described four rubbing portions (10p1u, 10p1d, 10p2u, 10p2d), so that the distance between the developing roller 10d and the photosensitive drum 7 can be stably held. The four rubbing portions (10p1u, 10p1d, 10p2u, 10p2d) are distance holding portions that hold the distance between the developing roller 10d and the photosensitive drum 7.

  Further, the first drum rubbing portion 10p2u of the photosensitive drum contact surface 10m2 and the first developing roller rubbing portion 10p1u of the developing roller contact surface 10m1 regulate and prevent the rotation of the spacer 10m associated with the rotation of the developing roller 10d. Also serves as a blocking unit 10m4.

  When the distance L3 between the first developing roller rubbing portion 10p1u and the first drum rubbing portion 10p2u is measured in a direction parallel to the line La, L3 is the closest position between the surface of the photosensitive drum 7 and the surface of the developing roller 10d. It is larger than the distance at (the shortest distance). That is, the spacer 10m has a width larger than the shortest distance between the developing roller 10d and the photosensitive drum 7 on the upstream side of the line La in the rotation direction of the developing roller 10d and the photosensitive drum 7.

  For this reason, even if the developing roller 10d and the photosensitive drum 7 rotate during image formation, the spacer 10m does not rotate. The first developing roller rubbing portion 10p1u and the first drum rubbing portion 10p2u come into contact with the developing roller 10d and the photosensitive drum 7, respectively, so that the spacer 10m moves in the rotation direction of the developing roller 10d and the photosensitive drum 7. To prevent it.

  Further, as shown in FIG. 4, the spacer 10m is provided with a longitudinal regulating portion 10m3 that regulates the movement of the developing roller 10d in the axial direction (longitudinal direction). Hereinafter, the longitudinal restriction portion 10m3 may be simply referred to as a restriction portion.

  As shown in FIGS. 1 and 5, the spacer 10m is attached to the longitudinal end of the developing roller 10d. The restricting portion 10m3 is sandwiched between the end surface of the developing roller 10d and the developing roller gear 10n and is prevented from moving in the longitudinal direction. Thus, the spacer 10m is positioned between the end surface of the developing roller 10d and the end surface of the developing roller gear 10n in the axial direction of the developing roller 10d.

  Further, as described above, the developing unit 10 and the drum unit 11 are rotatable around the coupling holes 10p1 and 10p2. By applying a predetermined pressing force between the developing unit 10 and the drum unit 11 using a spring or the like, the photosensitive drum 7 and the developing roller 10d are biased and pressurized in a direction approaching.

  With this applied pressure, the spacer 10m is brought into contact with the developing roller 10d at the developing roller contact surface 10m1, and is brought into contact with the surface of the photosensitive drum 7 at the photosensitive drum contact surface 10m2.

  As described above, the spacer 10m includes the developing roller contact surface 10m1 and the photosensitive drum contact surface 10m2. The spacer 10m is sandwiched between the developing roller 10d and the photosensitive drum 7 by a predetermined pressure, thereby guaranteeing (holding) the developing roller 10d and the photosensitive drum 7 at a constant interval and distance. .

  In this embodiment, the photosensitive drum contact surface 10m2 has a radius substantially equal to the outer peripheral radius of the photosensitive drum 7, and the entire photosensitive drum contact surface 10m2 or part of the photosensitive drum contact surface 10m2 serves as a photosensitive drum side interval guarantee section. Rubbing against the photosensitive drum.

  Similarly, the developing roller contact surface 10m1 has a radius substantially equal to the outer peripheral radius of the developing roller 10d, and a part of the developing roller contact surface 10m1 rubs against the developing roller 10d as a developing roller side interval guarantee portion.

  Further, in this embodiment, as shown in FIG. 4, a scraping portion 10m7 for scraping foreign matter on the surface of the photosensitive drum 7 is provided upstream of the photosensitive drum contact surface 10m2 in the rotational direction of the photosensitive drum 7 with a spacer 10m. And formed integrally.

  The scraping portion 10m7 is formed in a thin plate shape having a thickness T of about 0.1 to 0.3 mm, and the width in the longitudinal direction is equal to or greater than the width in the longitudinal direction of the photosensitive drum contact surface 10m2. Moreover, although the shape of the front-end | tip part of the scraping part 10m7 may be a plane or a curved surface, it is preferable to form an edge because scraping performance is good.

  Therefore, the tip of the scraping portion 10m7 of this embodiment forms an edge with a ridge line 10m8, and is in contact with the surface of the photosensitive drum 7 at this edge (ridge line 10m8). That is, the ridge line 10 m 8 is a contact portion of the scraping portion 10 m 7 with respect to the photosensitive drum 7. Here, the ridge line 10m8 is on the most upstream side in the rotation direction of the photosensitive drum 7 in the contact portion between the spacer 10m and the photosensitive drum 7 in a cross section perpendicular to the central axis of the photosensitive drum 7 (see FIG. 9). There is a point.

  That is, the ridge line 10m8 is upstream of the photosensitive drum contact surface 10m2 in the rotational direction of the photosensitive drum 7.

  The ridge line 10m8 scrapes off the developer on the surface of the photosensitive drum 7, thereby suppressing the developer from adhering to the photosensitive drum contact surface 10m. For this purpose, in the rotational direction X2 of the photosensitive drum 7, the upstream end of the region where the drum contact surface 10m2 and the photosensitive drum 7 are in contact, or further upstream of the upstream end in the rotational direction X2. The ridgeline 10m8 should just be arrange | positioned in the position. At this time, the intrusion of toner into the contact area between the drum contact surface 10m2 and the photosensitive drum 7 can be suppressed by the ridge line 10m8.

  Further, the ridge line 10m8 is inclined so as to be in contact with the central axis direction k of the photosensitive drum 7 (substantially parallel to the developing roller central axis direction i). This is because if the ridgeline 10m8 has an inclination θ, the scraped foreign matter CT can be easily moved to the outside in the longitudinal direction along the slope, which is preferable for scraping off the foreign matter CT. In this embodiment, θ = 15 °.

  That is, the ridge line 10m8 is a region inclined from the upstream position in the rotation direction of the photosensitive drum 7 and the inner position in the longitudinal direction toward the downstream position in the rotation direction and the outer position in the longitudinal direction.

  Further, the foreign matter led to the outside in the longitudinal direction along the inclination of the ridge line 10m8, that is, in the direction away from the image forming unit, remains at a position far from the image forming unit so as not to approach the image forming unit again. It is desirable.

  A specific example of the measure for that is shown in FIG. In the spacer 10m, a corner (developer holding part) 10m10 for holding the removed developer and an extension part 10m9 extending the ridge line 10m8 are formed. The scraping portion 10m7 has an extension portion 10m9 obtained by further extending the ridgeline 10m8 outward. The inclination of the extension 10m9 is opposite to the inclination of the ridge line 10m8, and the inclination angle is θ ′. That is, the extension 10m9 is a region inclined from the downstream position in the rotation direction of the photosensitive drum 7 and the inner position in the longitudinal direction toward the upstream position in the rotation direction and the outer position in the longitudinal direction. The extending portion 109m is disposed outside the ridgeline 10m8 in the longitudinal direction. Then, a corner portion 10m10 is formed for retaining the foreign matter CT at a place where the inclination θ of the ridge line changes from θ ′.

  That is, the contact portion of the scraping portion 10m7 with respect to the photosensitive drum 7 has two regions (ridge line 10m8 and its extension 10m9) inclined at different angles (θ and θ ′), and the boundary (inclination) between these regions. Is the corner 10m5. The developer scraped off by the scraping portion 10m7 gathers at the corner portion 10m5 along the ridge line 10m8 and the extension portion 10m9 and is held at the corner portion 10m5.

  If comprised in this way, even if the foreign material CT led to the edge part by the ridgeline 10m8 of inclination | tilt angle (theta) tries to move further outside, the foreign material CT will not move outside by the ridgeline 10m9 of reverse inclination, but inside. Returned to Therefore, the foreign matter CT can be stably held at the corner 10m10 where the inclination of the ridge line is switched.

  However, this is not the case when the amount of foreign matter on the surface of the photosensitive drum is small. If the scraped foreign matter stays in the scraping portion 10m7 and does not overflow, the foreign matter does not enter the photosensitive drum contact surface 10m2. Therefore, it is not necessary to incline the ridgeline 10m8 at the tip, that is, the inclination θ = 0 ° may be used.

  Here, FIG. 8 is a view showing two types of configurations of the spacer 10m described above and the spacers of other embodiments described later, as seen from a direction perpendicular to the central axis direction i of the developing roller. . In this embodiment shown in FIG. 8A, the width L2 of the ridgeline 10m8 in the central axis direction k or i and the width L1 of the photosensitive drum contact surface 10m2 in the same direction are the same length (L1 = L2). The case where the width L2 and the width L1 are at the same position in the central axis direction k or i is shown. However, the shape of the scraping portion 10m7 is not limited to this. For example, FIG. 7 and FIG. 8B showing the shape of the entire spacer will be described as an example showing another embodiment. 7A and 7B and FIG. 8B only have different viewpoints, and all show the same spacer configuration.

  As shown in FIGS. 7 and 8B, the width L2 of the ridgeline 10m8 may be larger than the width L1 of the photosensitive drum contact surface 10m2 (L2> L1). In this case, the entire width L1 of the photosensitive drum contact surface 10m2 may be positioned so that the width L2 of the ridge line 10m8 overlaps the entire area. Thus, the photosensitive drum contact surface 10m2 of the spacer 10m and the photosensitive drum 7 can be rubbed with each other while the ridgeline 10m8 always scrapes off the foreign matter on the surface of the photosensitive drum 7.

  Since the scraping portion 10m7 is formed integrally with the spacer 10m, the positions of the scraping portion 10m7 and the photosensitive drum surface can be determined with high accuracy. Therefore, it is possible to suppress a variation in contact pressure of the scraping portion 10m7 described later and maintain stable scraping performance.

  With these shapes, even when a small amount of toner or paper dust adheres to the surface of the photosensitive drum 7, the scraping unit 10m7 surely scrapes these foreign substances, and at least the position in the longitudinal direction of the photosensitive drum contact surface 10m2 Can be excluded.

  Further, the scraping portion 10m7 is elastically deformed and abuts against the surface of the photosensitive drum 7, but the abutting pressure is lower than the abutting pressure at the nipped photoconductor drum contact surface 10m2. By setting it to a value, the repulsive force does not affect the SD gap retention.

  With the configuration of the scraping portion 10m7 described above, it is possible to stably prevent foreign matter from entering the photosensitive drum contact surface 10m2, and it is possible to prevent the occurrence of defective images due to unexpected SD gap fluctuations.

  In this embodiment, the portion that supports the spacer 10m is the surface of the developing roller 10d. However, the present invention is not limited to this, and the present invention can also be applied to the case where the spacer 10m is supported by the journal portion 10dj of the developing roller 10d. .

  In this embodiment, the developing roller 10d and the photosensitive drum 7 are arranged with a certain gap between the surfaces, that is, the configuration adopting the non-contact developing method is described as an example. Absent. For example, the spacer 10m described in this embodiment may be adopted in the configuration of the contact development method shown in FIGS. 10 (a) and 10 (b). FIG. 10A is a cross-sectional view perpendicular to the developing roller 10d, and FIG. 10B is an explanatory view showing the arrangement of the spacers 10m in the longitudinal direction of the developing roller 10d.

  10A and 10B, the developing roller 10d has an aluminum sleeve 10d2 and a rubber layer (elastic portion) 10d3 provided on the surface thereof. The spacer 10m is provided at both ends of the aluminum sleeve 10d2. The rubber layer 10d33 of the developing roller 10d is compressed by a certain amount and is in contact with the photosensitive drum 7.

  That is, in FIG. 10, the spacer 10m maintains the distance between the developing roller 10d and the photosensitive drum 7 (the distance between the centers) in a state where the surfaces of the developing roller 10d and the photosensitive drum 7 are in contact with each other. Thus, the compression amount of the rubber layer 10d3 is kept constant. Even in the case shown in FIG. 10, if the scraping portion 10m7 described above is provided in the spacer 10m, the toner attached to the photosensitive drum 7 can be scraped off.

A image forming apparatus B process cartridge X1 developing roller rotation direction X2 photosensitive drum rotation direction 7 photosensitive drum 10 developing unit 10d developing roller 10m spacer 10m1 developing roller contact surface 10m2 photosensitive drum contact surface 10m3 regulating portion 10m4 rotation blocking portion 10m7 scraping Take part 10m8 Ridge line 10m9 Ridge line 10m10 Corner

Claims (12)

In the interval ensuring member that maintains the distance between the image carrier on which the latent image is formed and the developer carrier that carries the developer,
A distance holding unit that holds the distance between the image carrier and the developer carrier by contacting the image carrier and the developer carrier;
A rotation prevention unit that prevents the spacing assurance member from moving in the rotation direction of the developer carrier;
In the rotation direction of the image carrier, the distance holding unit is disposed further upstream from the upstream end of the region in contact with the image carrier, and comes into contact with the image carrier by contacting the image carrier. A scraping part for scraping off the developer adhering to the image carrier;
A spacing assurance member comprising: The contact portion in contact with said image bearing member before Symbol scraping portion,
A region inclined from an upstream position in the rotation direction of the image carrier and an inner position in the longitudinal direction of the image carrier toward a downstream position in the rotation direction and an outer position in the longitudinal direction. The spacing assurance member according to claim 1. In the interval ensuring member that maintains the distance between the image carrier on which the latent image is formed and the developer carrier that carries the developer,
A distance holding unit that holds the distance between the image carrier and the developer carrier by contacting the image carrier and the developer carrier;
A rotation prevention unit that prevents the spacing assurance member from moving in the rotation direction of the developer carrier;
In the rotation direction of the image carrier, the distance holding unit is disposed on the upstream end of the region in contact with the image carrier or on the further upstream side than the upstream end and contacts the image carrier. A scraping part for scraping off the developer attached to the image carrier,
With
The contact portion of the scraping portion that contacts the image carrier is located upstream from the position in the rotational direction of the image carrier and from the inside in the longitudinal direction of the image carrier, to the downstream in the rotational direction and in the longitudinal direction. A spacing assurance member characterized by having a region inclined toward an outer position in the case. The distance TPA member, the spacing guarantees member according to any one of claims 1 to 3, characterized in that it comprises a developer holder for holding a developer scraped by the scraping portion. The contact portion in contact with said image bearing member before Symbol scraping portion,
5. The interval ensuring member according to claim 4 , wherein the gap holding member has two regions inclined at different angles with respect to the axis of the image carrier, and the boundary thereof serves as the developer holding portion. In the interval ensuring member that maintains the distance between the image carrier on which the latent image is formed and the developer carrier that carries the developer,
A distance holding unit that holds the distance between the image carrier and the developer carrier by contacting the image carrier and the developer carrier;
A rotation prevention unit that prevents the spacing assurance member from moving in the rotation direction of the developer carrier;
In the rotation direction of the image carrier, the distance holding unit is disposed on the upstream end of the region in contact with the image carrier or on the further upstream side than the upstream end and contacts the image carrier. A scraping part for scraping off the developer attached to the image carrier,
With
The gap ensuring member has a developer holding portion that holds the developer scraped off by the scraping portion, and a contact portion of the scraping portion with the image carrier is on an axis of the image carrier. An interval ensuring member, comprising two regions inclined at different angles to each other, the boundary being the developer holding portion. Contact pressure when the scraper unit is brought into contact with the image bearing member, any of claims 1 to 6 wherein the distance holder is being lower than the contact pressure when in contact with the image bearing member The spacing assurance member according to claim 1. In the interval ensuring member that maintains the distance between the image carrier on which the latent image is formed and the developer carrier that carries the developer,
A distance holding unit that holds the distance between the image carrier and the developer carrier by contacting the image carrier and the developer carrier;
A rotation prevention unit that prevents the spacing assurance member from moving in the rotation direction of the developer carrier;
In the rotation direction of the image carrier, the distance holding unit is disposed on the upstream end of the region in contact with the image carrier or on the further upstream side than the upstream end and contacts the image carrier. A scraping part for scraping off the developer attached to the image carrier,
With
An interval ensuring member, wherein a contact pressure when the scraping portion contacts the image carrier is lower than a contact pressure when the distance holding portion contacts the image carrier. The developer carrying body and the image carrying body are rotated so as to move their opposing surfaces in the same direction,
The rotation prevention unit is in contact with the image carrier on the upstream side in the rotation direction of the image carrier from a line connecting the center of the image carrier and the center of the developer carrier, and from the line Also, the gap ensuring member is configured to prevent the developer carrying member from moving in the rotation direction of the developer carrier by contacting the developer carrier on the upstream side in the rotation direction of the developer carrier. The spacing assurance member according to any one of claims 1 to 8 . In a developing device used in an image forming apparatus,
A developer carrier that carries a developer for developing a latent image formed on the image carrier, and rotates together with the image carrier;
The gap ensuring member according to any one of claims 1 to 9 ,
A developing device comprising: The developing device according to claim 10 , wherein the gap ensuring member is attached to the developer carrying member. In a process cartridge that can be attached to and detached from the main body of an image forming apparatus,
An image carrier;
A developing device according to claim 10 or 11 ,
A process cartridge comprising:

Images