JP3665262B2 - Developing device and method for adjusting facing distance - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device used in an image forming apparatus such as an electrophotographic copying apparatus or a printer, and more particularly to a method for adjusting a facing distance between a developing roller and a developer regulating member.
[0002]
[Prior art]
An electronic copying apparatus, which is an image forming apparatus, includes a photosensitive drum in its body, and a charging charger, a developing device, a transfer / peeling charger, a cleaning device, and the like are arranged around the photosensitive drum along a rotation direction. Is arranged.
[0003]
At the time of image formation, the surface of the photosensitive drum charged by the charging charger is irradiated with reflected light reflected from the document, and an electrostatic latent image corresponding to the document image is formed. The electrostatic latent image is sent to the developing device by the rotation of the photosensitive drum, and is visualized by supplying the developer from the developing device. The visible image is transferred to a sheet by the action of a transfer charger, then peeled off, sent to a fixing device, fixed, and then discharged.
[0004]
By the way, the developing device has to form a uniform developer layer on the peripheral surface of the developing roller in order to make the electrostatic latent image on the photosensitive drum well visible. Therefore, a developer regulating member called a plate-like or bar-like doctor blade is disposed at a position that is narrow and has a uniform interval with the circumferential surface of the developing roller.
[0005]
In such a developing device, in order to obtain an image having a uniform density over the entire peripheral surface of the photosensitive drum, the interval between the developing portions formed between the peripheral surface of the photosensitive drum and the peripheral surface of the developing roller, Further, it is necessary to strictly manage the facing distance (hereinafter, referred to as “facing distance”) formed between the tip of the developer regulating member fixed to the developing casing and the peripheral surface of the developing roller.
[0006]
The spacing between the developing sections is important for supplying the developer satisfactorily to the electrostatic latent image on the photosensitive drum, and the spacing between the opposed portions is a stable amount of developer on the circumferential surface of the developing roller. It is for layering. In particular, since the amount of developer supplied from the developing device to the photosensitive drum is defined by the facing distance, the size of the facing distance is important during the manufacture and maintenance of the developing device. It becomes.
[0007]
Therefore, conventionally, in order to set the facing distance, a special jig for gap adjustment such as a gap gauge is inserted between the tip of the developer regulating member and the peripheral surface of the developing roller, After the mounting position of the developer regulating member is adjusted with, for example, the developer regulating member is fixed with a set screw.
[0008]
FIG. 16 shows a mounting structure of a developer restricting member in a conventional developing device. As shown in the figure, the developer restricting member (with respect to the developing roller 10 fixed to the casing via a bearing member 51) is shown. When fixing the doctor blade 30) to a predetermined position in the developing casing 2, the screw hole 2a provided on the side surface of the casing 2 of the developing device is installed as a long hole to attach the doctor blade 30, and the position where the doctor blade 30 is attached. To be subtly changeable. Thus, the doctor blade 30 is completely fixed and attached using the set screw 50 in the long hole in a state where the distance (opposite distance) between the developing roller 10 and the doctor blade 30 is adjusted with a clearance gauge.
[0009]
In addition, as shown in FIG. 17, the doctor blade 30 may be fixed to the blade support frame 2d provided on the upper surface side of the casing 2 instead of the side surface of the casing 2 of the developing device. In this case, it is not necessary to use two upper screws 50, 50 on one side and a total of four set screws 50 on both sides, and the doctor blade 30 is attached to the blade support frame 2d with two set screws 50. It can be fixed. In this case, a long hole 30a is formed in the doctor blade 30, and the opposing distance is adjusted with a clearance gauge, and then fixed with a set screw 50.
[0010]
By the way, in the case of the above-described high-quality developer, the interval between the developing portions is a value of 0.5 mm to 0.75 mm, and this value needs to be maintained over the entire length direction of the developing roller. However, even if a gap gauge is inserted at both ends of the developer restricting member to set the distance between both ends of the developer restricting member, the developing device may be affected by mechanical play such as a bearing that supports the developing roller. The development interval often fluctuates during this operation, and adjustment is often troublesome. In maintenance and management of the developing device, the interval may be readjusted in consideration of wear of the developing roller and the bearings that support it. With difficulty.
[0011]
In order to solve the above problems, in Japanese Patent Laid-Open No. 5-313482, when attaching the developer regulating member to the developing roller, a protruding portion is formed at both ends of the developer regulating member, and this protruding portion is a non-image area of the developing roller. The gap between the developing roller and the developer regulating member can be accurately adjusted with a simple operation.
[0012]
Japanese Patent Application Laid-Open No. 10-171242 includes a variable roller having a spiral peripheral portion whose distance from the center continuously changes to a stepped portion, and the variable roller is used as a rotation support shaft at both ends of the developing roller. The developer roller is attached so as to be rotatable, the tip end surface of the developer restricting member is pressed against the peripheral edge of the variable roller, and the facing distance is adjusted by rotating the variable roller around the developing roller.
[0013]
[Problems to be solved by the invention]
However, in the above Japanese Patent Laid-Open No. 5-313481, development is performed. Agent The protrusions formed at both ends of the regulating member abut against the developing roller, which may cause damage to the developing roller by applying a load to the developing roller, etc. It is impossible to cope with the warp of the developer regulating member due to heat or the like, and it is actually difficult to supply the developer to the photosensitive drum satisfactorily.
[0014]
In addition, since the protruding portion having a predetermined step is brought into contact with the developing roller, the once-set facing interval cannot be adjusted. For example, when the interval needs to be adjusted again during maintenance. The problem of not being able to respond is also invited.
[0015]
On the other hand, in Japanese Patent Application Laid-Open No. 10-171242, the variable roller has a spiral shape, which causes a problem that it is expensive and difficult to form. In addition, since variable rollers are provided at both ends of the developing roller, if there is a difference in the rotational movement amount of each variable roller, a gap occurs in the facing distance, and a uniform developer layer cannot be formed. There was a problem.
[0016]
In addition, the adjustment amount of the facing interval (hereinafter referred to as “facing interval”) formed between the tip of the developer regulating member and the peripheral surface of the developing roller is 0.1 mm or less (for example, a set value) On the other hand, an adjustment range of ± 25 μm is required). For this reason, the work is extremely complicated and difficult, and the actual condition is that skill is required for the adjustment.
[0017]
SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a developing device capable of adjusting an accurate facing distance in a short time by an extremely simple operation.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, a developing device according to the present invention includes a developing roller that is rotatably supported by a support shaft and carries and conveys the developer, and a developer regulation that regulates the layer thickness of the developer on the developing roller. A developing device comprising: a member, and a spacer member rotatably attached to a support shaft, and a spacer member that abuts the developer regulating member and secures a desired interval between the developer regulating member and the developing roller. The member adopts a configuration having a line-symmetric cross-sectional shape in which the distance from the rotation center of the support shaft to the outer peripheral portion is continuously changed, so that the opposing spacing is maintained regardless of which direction the spacer member is rotated. The spacer member is not front and back, and may be loosely fitted to the support shaft from either side, so that there is no mistake in attaching the spacer member, and the attaching operation can be performed easily.
[0019]
Here, the shape of the spacer member is not particularly limited as long as the distance from the rotation center of the support shaft to the outer peripheral portion changes continuously and is a line-symmetric cross-sectional shape, and various elliptical shapes, etc. However, if a spacer member that has a circular outer peripheral surface and is rotatably mounted at a position that is eccentric with respect to the support shaft is used, it is easy to process and can be manufactured at low cost. Become. In other words, since the spacer member has a simple circular shape, the outer peripheral surface can be easily formed by cutting or molding, and a spacer member can be created simply by forming a through hole for a spindle at a predetermined position. It becomes possible to do.
[0020]
Further, in addition to the above-described configuration, if the spacer member has a concave groove portion that can fit the developer regulating member, the developer regulating member fits into the concave groove portion of the spacer member. Thus, the facing distance can be adjusted strictly in a stable state.
[0021]
In this case, the spacer member only needs to have a constant distance from the rotation center of the support shaft to the outer periphery of the spacer member, and may be, for example, a fan shape or a circular shape. Among them, if a shape having a circular outer peripheral surface and a plurality of concave grooves having different depths is used, like the spacer member, the outer peripheral surface has a circular shape, a disk shape, or the like. Since it is a simple circular shape, it is easy to process, and if the depth (cutting amount) of the concave groove is accurately controlled, the groove width should be formed so that the developer regulating member can be fitted approximately. Well, it is not necessary to process the spacer member finely, and the complexity of the shape is avoided, so that the manufacturing cost can be reduced. Further, by forming a plurality of concave grooves, it is possible to finely adjust the facing distance.
[0022]
Furthermore, if the concave grooves are arranged so that the depth changes stepwise, the distance between the opposing members gradually becomes deeper or shallower by simply rotating the spacer member by a predetermined angle, so that fine adjustment is easy. Can be done.
[0023]
The spacer member is not particularly limited as long as the spacer member is rotatably attached to the developing roller, and can be combined with the bearing member. Specifically, a bearing member that rotatably supports the support shaft of the developing roller is provided, and the bearing member has a frame portion that is rotatably held in a state in which the spacer member is fitted therein, and the developer restriction on the frame portion. If a slit is formed in which the member can be fitted into the groove of the spacer member, the spacer member can be viewed as being integrated with the bearing member, and the spacer member can also be used as the bearing portion. Therefore, the rotation stability of the developing roller can be improved, and the spacer member and the bearing member are separated from each other. Therefore, the spacer member can be rotated while the support shaft is stably supported by the bearing member. It is also possible to adjust the facing distance.
[0024]
Further, the spacer member can have a function of a bearing member. That is, if a configuration is adopted in which the spacer member is rotatably attached to the casing and the support shaft of the developing roller is rotatably supported, the bearing member becomes unnecessary, and the number of parts can be reduced. In this case, the developer restricting member is fitted in the concave groove portion to prevent the spacer member from rotating, and the spacer member can function as a bearing.
[0025]
Further, the material of the spacer member is not particularly limited as long as it has a strength that can stably abut the end portion of the developer regulating member in a state where the rotation support shaft of the developing roller is fitted. However, if the spacer member and the bearing member are formed of a conductive material such as a copper-based sintered alloy or a conductive resin, a bias voltage can be applied to the developer regulating member via the developing roller. It becomes possible to prevent the developer from adhering to the developer regulating member.
[0026]
The developing apparatus described above can stabilize the facing distance by providing a biasing unit that biases the developer regulating member toward the developing roller. In particular, in the case of a spacer member having a concave groove portion, the developer regulating member is securely fitted into the concave groove portion, and is always in the depth of the concave groove portion, so that the facing distance is strictly controlled. Can do.
[0027]
Further, if a rotating means for rotating the spacer member is provided, the facing distance can be easily adjusted, and the facing distance can be automatically adjusted.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
As shown in FIG. 1, the developing device in the image forming apparatus according to this embodiment includes a developing casing 2 containing a two-component developer in which a magnetic carrier and a nonmagnetic toner are mixed, and a developing casing facing the photosensitive drum 40. 2 and a developing roller 10 disposed in the opening, and a developer stirring blade 4 and a circulating screw 6 disposed in parallel in the developing casing 2. The developer regulating member 30 (doctor) and the developing roller 10 are attached to the developing casing 2 with a predetermined facing interval. The developing roller 10 includes a cylindrical sleeve 10c and a magnet roller 10a disposed inside the sleeve 10c.
[0029]
The developer accommodated in the developing casing 2 is stirred and circulated by the developer stirring blade 4 and the circulation screw 6, and in the process, is attracted and held on the outer peripheral surface of the sleeve 10c by the action of the magnet roller 10a. . The developer held on the sleeve 10c in this way is conveyed toward the developing unit facing the photosensitive drum 40 by the rotation of the sleeve 10c, and the layer thickness is regulated by the developer regulating member 30 during the conveyance. Then, it is uniformly coated on the sleeve 10c as a developer layer having a predetermined layer thickness, and is used for development in the developing section.
[0030]
In the present embodiment, a disc-shaped spacer member 52 having a diameter larger than the outer diameter of the sleeve 10c is used. The details will be described below with reference to FIGS. 2 is a perspective view of the developing device in the present embodiment, and FIG. 3 is a front sectional view of the developing device (longitudinal direction of the developing roller). The spacer member 52 used in the present embodiment has a disk shape, and a through hole 52a for inserting a support shaft is formed at a position eccentric from the center. The developing roller 10 is supported by the bearing member 51 in a state where the support shaft 10 b is passed through the through hole 52 a of the spacer member 52.
[0031]
The bearing member 51 is fixed to the opening 2 b formed at the developing roller mounting position of the casing 2, whereby the developing roller 10 is installed in a rotatable state in the developing casing 2. The spacer member 52 has a structure in which the rotational driving force of the developing roller 10 is not transmitted, and can be rotated with respect to the support shaft 10b regardless of the rotation of the developing roller.
[0032]
4A and 4B are schematic views showing the developing device, where FIG. 4A is a front sectional view and FIG. 4B is a side view. The developer regulating member 30 is formed slightly longer than the axial length of the sleeve 10c, and its end 30b is opposed to the spacer member 52 disposed at the axial end of the sleeve 10c. Further, the developer regulating member 30 is attached to a support portion 56 provided on the developing casing 2 thereabove so as to be able to advance and retreat in a direction orthogonal to the support shaft 10b of the developing roller.
[0033]
Further, as a biasing means, a spring member 53 such as a compression spring is disposed between the developer support portion 56 and the developer regulating member 30, so that the developer regulating member 30 is attached to the developing roller 10 side. The spacer member 52 is brought into contact with the spacer member 52. Therefore, by rotating the spacer member 52, the distance between the developer regulating member 30 and the developing roller 10, that is, the facing distance can be adjusted.
[0034]
Note that the support shaft 10b, the spacer member 52, and the like are disposed at both ends of the developing roller 10, and when the opposing distance between the developing roller 10 and the developer regulating member 30 is not parallel at both ends, one spacer A uniform developer layer can also be formed by adjusting only the member 52.
[0035]
Although the spacer member 52 has a disk shape, the center of rotation is provided at a position decentered from the center of the disk. Therefore, the distance from the shaft core to the peripheral edge of the spacer member 52 depends on the rotation phase applied to the spacer member 52. Come different. That is, the distance to the peripheral edge is the maximum or the minimum on one side and the other side of the shaft core that are 180 degrees apart, and the distance to the peripheral edge is between the maximum and minimum when the spacer member 52 is in a phase beyond this. Gradually changes. Therefore, by rotating the spacer member 52 in any direction and changing the distance from the axial center to the peripheral edge, a desired interval is ensured between the developing roller 10 and the developer regulating member 30. Strict facing distance can be maintained.
[0036]
Actually, development is performed at a phase where the distance from the axis to the peripheral edge is the minimum. Agent The front end of the regulating member 30 abuts against the developing roller 10, and the distance is set to increase as the distance to the peripheral edge increases when the phase is separated. That is, the spacer member 52 functions as an eccentric cam, and the lift amount of the cam varies depending on the phase.
[0037]
For the purpose of merely changing the facing distance between the developing roller 10 and the developer regulating member 30, it is sufficient to rotate the spacer member 52 in any direction, and the shape of the spacer member 52 is also the center. It is possible on either side of the line. However, from the viewpoint of preventing work mistakes at the time of adjustment and reducing the burden on the operator, in this embodiment, the cross-sectional shape of the spacer member 52 is such that the opposing distance can be reliably adjusted regardless of the direction of rotation. Is a line-symmetric shape in which the distance from the center of rotation to the peripheral edge changes continuously.
[0038]
[Second Embodiment]
FIG. 5 is a perspective view of a developing device showing a second embodiment of the present invention, and FIG. 6 is a schematic view of the developing device showing a state where a rotating means is added. The present embodiment is characterized in that the end portion of the developer regulating member 30 and the spacer member 52 are arranged outside the developing casing 2, and other configurations are the same as those in the first embodiment. .
[0039]
That is, in this embodiment, in order to install the spacer member 52 outside the developing casing 2, a slit 2 c is formed in the casing 2, and the end portion 30 b of the developer regulating member 30 passes outside the slit 2 c. The developer regulating member 30 is exposed to the peripheral surface of the spacer member 52 so that the operator can adjust the facing distance from the outside of the developing device, and the operability can be improved. It becomes.
[0040]
The spacer member 52 can be manually rotated, but it is also possible to automatically adjust the rotation by a rotating means. In particular, when the spacer member 52 is arranged outside the developing device as in the present embodiment, as shown in FIG. 6, the gear 55 that is integrally formed with the spacer member 52 and loosely fits on the support shaft 10b. The spacer member 52 may be rotationally driven using a rotating means including a driving member 54 (motor) and a gear 57 formed on the rotating shaft of the driving member 54 and meshing with the gear 55. In this case, if the spacer members 52 on both sides of the support shaft are synchronously controlled to rotate by a predetermined rotation angle, the facing interval d can be automatically adjusted to a predetermined value.
[0041]
In this case, a sensor for detecting the facing distance (not shown, for example, a position sensor for detecting the height of the developer regulating member 30) and a signal from this sensor are periodically recognized. If the interval is not a predetermined interval, the facing interval can be automatically adjusted by providing a control unit (not shown) such as a microcomputer for driving and controlling the spacer member 52 by the rotating unit. Needless to say.
[0042]
[Third Embodiment]
A third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the spacer member 52 has a circular outer peripheral surface, the center of which is the center of rotation, and a point in which concave grooves having different depths are formed on the outer peripheral portion. There are features, and other configurations are the same as those of the second embodiment.
[0043]
In other words, in the present embodiment, the developer regulating member 30 is fitted into the recessed groove portion 52b formed in advance at a predetermined depth (cut amount), so that the opposing interval is not displaced and is very stable. An accurate facing distance can be set easily.
[0044]
FIG. 7 is a perspective view showing the spacer member 52 of the present embodiment. The spacer member 52 only needs to have a circular outer peripheral surface. For example, the spacer member 52 has a roller shape having a large axial length as shown in FIG. 7A or a plate thickness as shown in FIG. It is possible to use any of the thin disk-shaped ones. A through hole 52a for inserting a support shaft is formed at the center position of the spacer member 52, and is inserted through the support shaft 10b. A plurality of concave groove portions 52b are formed on the outer peripheral surface of the spacer member 52, and each concave groove portion 52b is arranged so that the cutting amount (depth of the concave groove portion) changes stepwise. It is possible to easily adjust the facing distance d by changing the facing distance d stepwise.
[0045]
In the present embodiment, similarly to the first embodiment, the support 56 of the developer regulating member 30 in the developing casing 2 is provided with a recess in which a spring member 53 such as a compression spring is inserted. By attaching the developer regulating member 30 to the support portion 56 via the spring member 53, the developer regulating member 30 is urged in the direction of the developing roller 10 and the end thereof is securely fitted into the groove 52b. Become.
[0046]
Specifically, as shown in FIG. 8, eight concave grooves 52b1... 52b8 are formed radially at an equal pitch with respect to the spacer member 52, and the depth of each concave groove 52b is increased by 25 μm. . In FIG. 8, the groove 52b1 is 25 μm deep, the groove 52b2 is 50 μm deep, the groove 52b3 is 75 μm deep, the groove 52b4 is 100 μm deep, the groove 52b5 is 125 μm deep, and the groove 52b6 is deep. The depth is 150 μm, the groove 52b7 is 175 μm deep, and the groove 52b8 is 200 μm deep.
[0047]
In this case, the depth (cut amount) changes by 25 μm between the groove portions 52b adjacent to each other at 45 ° intervals. Therefore, the distance can be adjusted as much as 200 μm in total width only by rotating the spacer member 52 once.
[0048]
Therefore, the developer regulating member 30 moves forward or backward with respect to the developing roller 10 only by rotating the spacer member 52 and changing the position of the concave groove portion 52b against which the end of the developer regulating member 30 is pressed. . As a result, the facing distance d, which is the distance between the developing roller 10 and the developer regulating member 30, can be easily and reliably changed.
[0049]
When the facing distance is decreased, the spacer member 52 is rotated in a direction in which the cut amount of the concave groove portion 52b decreases (in FIG. 8, the direction of mark A), so that the predetermined concave groove portion 52b is notched in the frame portion 51a. It arrange | positions in the position corresponding to the part 51b, and the developer control member 30 is pressed with respect to the ditch | groove part 52b. On the other hand, when the facing distance d is increased, the spacer member 52 is rotated in the direction in which the cut amount of the concave groove portion 52b increases (in the direction of arrow B in FIG. 8), and the developer restriction is applied to the predetermined concave groove portion 52b. The member 30 is pressed. As a result, the facing distance d can be changed stepwise, so that the facing distance d can be adjusted more easily as described above.
[0050]
The specific spacing d is, for example, approximately 0.50 mm to 0.75 mm in the case of using a high image quality developer, but is not limited thereto. However, it changes as appropriate according to the standard and type of the developing device used. Therefore, the change range and the change pitch of the depth (cut amount) of the concave groove 52b formed in the spacer member 52 are not limited to the 200 μm range or the 25 μm pitch described above.
[0051]
The developer transport amount on the developing roller 10 increases as the facing distance d increases, and decreases as it decreases. Therefore, when the developing device or an image forming apparatus using the developing device is assembled and adjusted or maintenance service work is performed, the facing distance d can be easily and reliably adjusted only by rotating the spacer member 52 as necessary. As a result, the amount of developer transported by the developing roller 10 can be made stable and optimal in accordance with the use environment and use conditions of the image forming apparatus, and the image quality of the image forming apparatus can be improved. it can.
[0052]
9 and 10 are schematic front views showing the developing device according to this embodiment. FIG. 9 shows a case where a disk-shaped spacer member 52 is used, and FIG. 10 shows a roller-shaped spacer member 52. The case where is used is shown respectively. As shown in the figure, a spacer member 52 is further provided outside the bearing member 51 that pivotally supports the developing roller 10, and the urging means 53 develops the groove 52 b formed in the outer peripheral portion of the spacer member 52. The width of the facing interval d, which is the interval between the developing roller 10 and the developer regulating member 30, is defined by pressing and fitting the end of the tip (doctor blade edge) of the agent regulating member 30. In this state, the developer regulating member 30 does not directly contact the developing roller 10 and the developer regulating member 30 is fitted in the groove 52b of the spacer member 52. The situation where d shifts is also avoided. Therefore, it is possible to easily set a very stable and accurate facing distance d.
[0053]
[Fourth Embodiment]
11, 12 and 13 are diagrams showing a fourth embodiment of the present invention. The present embodiment is characterized in that the bearing member has a structure including a frame portion that holds the spacer member in a state in which the spacer member is fitted, and other configurations are the same as those of the third embodiment. It has become.
[0054]
That is, in this embodiment, since the spacer member 52 is fitted in the bearing member 51, it can be seen that both are integrated, and the rotation stability of the developing roller 10 is improved by increasing the bearing width. Can be made.
[0055]
As shown in FIGS. 11 and 12, the bearing member 51 that supports the developing roller 10 includes a disk-shaped bearing portion 51 c having a through hole in the center portion, and a substantially cylindrical frame portion 51 a into which the spacer member 52 is fitted. It is fixed by inserting a bearing 51c into an opening 2b formed in the casing 2. A spacer member 52 is fitted into a frame portion 51a exposed to the outside of the casing 2, and is rotatably attached to the support shaft 10b.
[0056]
The developer regulating member 30 is biased toward the developing roller 10 by a spring member (not shown) in a state where the leading end surface faces the developing roller 10. The developer regulating member 30 is fitted into a slit 2c formed from the top of the opening 2b of the developing casing 2 to the upper side, and thereby the position with respect to the developing roller 10 is defined. Further, the frame 51a of the bearing member 51 is formed with a notch 51b at a position corresponding to the slit 2c, and the side end of the developer regulating member 30 is the outer periphery of the spacer member 52 as shown in FIG. The opposing interval is defined by fitting into the concave groove portion 52b of the portion.
[0057]
[Fifth Embodiment]
14A and 14B are perspective views of a developing device showing a fifth embodiment of the present invention, where FIG. 14A is an exploded view of the developing device, and FIG. Shown respectively. In the present embodiment, the spacer member and the bearing member are combined to reduce the number of parts, and other configurations are the same as those of the third embodiment.
[0058]
The spacer member 52 in this embodiment includes a thick disc-shaped spacer portion 52c and a bearing portion 52d having a slightly smaller diameter than the spacer portion 52c, which are integrally formed concentrically. Is formed with a through hole 52a for bearing. Further, a plurality of groove portions 52b are formed on the outer peripheral surface of the spacer portion 52c, and each groove portion is arranged so that the cutting amount changes stepwise (typically one in the drawing). Only the groove 52b is shown).
[0059]
In the spacer member 52, the bearing portion 52 d is rotatably supported by the opening 2 b formed in the casing 2 in a state where the developing roller 10 is inserted through the through hole 52 a. Further, the developer regulating member 30 is inserted in a slit 2c formed from the top of the opening 2b of the casing 2 to the upper side so as to be able to advance and retreat, thereby defining the position of the developer regulating member 30 relative to the developing roller 10. Further, since the leading end portion of the developer regulating member 30 is engaged with the concave groove portion 52b of the spacer member 52 (FIG. 14B), the spacer member 52 is also prevented from rotating with the rotation of the developing roller 10. be able to. That is, the developer regulating member 30 and the concave groove portion 52b function as a rotation stop mechanism.
[0060]
In this embodiment, if the rotation means as described in the second embodiment is provided and the opposing interval can be automatically adjusted, the spacer members 52 arranged at both ends of the developing roller 10 are synchronized. By simply controlling the rotation by a predetermined rotation angle, the opposing distance d can be automatically adjusted to a predetermined value accurately even when the rotation distance cannot be strictly determined by fitting the developer regulating member 30 and the groove 52b. it can.
[0061]
The present invention is not limited to the above embodiment, and it is needless to say that many modifications and changes can be made within the scope of the present invention. For example, the size of the spacer member 52 is not particularly limited as long as the interval between the developing roller 10 and the developer regulating member 30 can be defined to be a constant interval. In the above embodiment, FIG. As shown in FIG. 4, the length from the center of the through hole 52a to the outer peripheral portion, that is, the radius R1 of the spacer member 52 is the length from the center of the rotation support shaft 10b of the developing roller 10 to the outer peripheral surface, that is, the length of the developing roller 10. Although the case where the radius is larger than the radius R2 (R1> R2) has been described, as shown in FIG. 15B, the radius R1 of the spacer member 52 may be smaller than the radius R2 of the developing roller 10 (R1 <R2).
[0062]
In the former case, the end portion 30b (the doctor blade edge) of the developer regulating member 30 that fits into the groove 52b of the spacer member 52 and the central portion 30c may be formed flat. There is no need for special processing. On the other hand, in the latter case, when the end portion 30b and the central portion 30c of the developer regulating member 30 are formed flat, the central portion 30c is positioned on the outer peripheral surface of the developing roller 10 before the end portion 30b is fitted into the concave groove portion 52b. Will abut. Therefore, the end portion 30b of the developer regulating member 30 needs to be formed in a shape protruding from the central portion 30c to prevent the central portion 30c and the developing roller 10 from coming into contact with each other. Compared to the former, the size of the spacer member 52 can be made smaller.
[0063]
【The invention's effect】
As is clear from the above description, according to the present invention, a spacer member having a line-symmetric cross-sectional shape in which the distance from the rotation center to the outer peripheral portion continuously changes is adopted. Even if it is rotated in the direction, it is possible to finely adjust the facing distance, and the spacer member has no front and back, so that the mounting operation can be easily performed.
[0064]
In particular, if a spacer member having a circular outer peripheral surface and rotatably mounted at a position eccentric with respect to the support shaft is used, it becomes easy to process and can be manufactured at low cost.
[0065]
In addition, if a spacer member having a circular outer peripheral surface and having a plurality of recessed groove portions with different depths is used, the developer regulating member is fitted into the recessed groove portion of the spacer member so that the spacer member is stable. In this state, the facing distance can be adjusted strictly and, like the spacer member, the outer peripheral surface is circular, so that it is easy to process and can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a developing device showing a first embodiment.
FIG. 2 is a perspective view of the developing device.
FIG. 3 is a front sectional view of the developing device.
4A and 4B are schematic views of the developing device, in which FIG. 4A is a front sectional view and FIG. 4B is a side view.
FIG. 5 is a perspective view of a developing device showing a second embodiment.
FIG. 6 is a front sectional view of the developing device.
FIGS. 7A and 7B are perspective views of a spacer member according to a third embodiment, in which FIG. 7A shows a roller shape, and FIG. 7B shows a disk shape.
FIG. 8 is a side view of the spacer member.
FIG. 9 is a schematic view of a developing device showing a third embodiment.
FIG. 10 is a schematic view of a developing device showing a third embodiment.
FIG. 11 is a perspective view of a developing device showing a fourth embodiment.
FIG. 12 is a perspective view showing a part of the developing device.
FIG. 13 is a side view showing a part of the developing device.
14A and 14B are perspective views of a developing device according to a fifth embodiment, in which FIG. 14A shows an exploded view and FIG. 14B shows a use state.
FIG. 15 is a schematic view showing an aspect of a developer regulating member.
FIG. 16 is a perspective view showing a mounting structure of a developer regulating member of a conventional developing device.
FIG. 17 is a perspective view showing another mounting structure of the developer regulating member.
[Explanation of symbols]
2 Development casing
10 Developing roller
30 Developer regulating member
51 Bearing member
52 Spacer member
52b Concave groove

Claims (8)

A developing roller that is rotatably supported by a support shaft, carries and conveys the developer, a developer regulating member that regulates the layer thickness of the developer on the developing roller, and is rotatably attached to the support shaft, A developing device that includes a spacer member that contacts the developer regulating member and secures a desired interval between the developer regulating member and the developing roller, the spacer member having a circular outer peripheral surface, 2. A developing device according to claim 1, wherein a plurality of recessed grooves having different depths into which the developer regulating member can be fitted are formed on the outer periphery. Each groove portion, the developing device according to claim 1, wherein the depth is characterized in that it is arranged to vary stepwise. The developing device of the spacer member rotation means for rotating the can according to claim 1 or 2, wherein provided. The developer developing apparatus according to claim 1, wherein the biasing means is provided for the regulating member to urge the developing roller side. A bearing member that rotatably supports the support shaft of the developing roller is provided, and the bearing member has a frame portion that is rotatably held in a state in which a spacer member is fitted, and the frame portion includes a developer regulating member. an apparatus according to any one of claims 1 to 4, characterized in that slits to allow fitting the member in the groove of the spacer member is formed. It said spacer member is rotatably mounted in the casing, a developing device according to any one of claims 1 to 5, characterized in that rotatably supports the shaft of the developing roller. 7. The developing device according to claim 5, wherein the spacer member and the bearing member are made of a conductive material. When the thickness of the developer carried on the developing roller rotatably supported by the support shaft is regulated by the developer regulating member, a predetermined interval is set between the developer regulating member and the developing roller. A plurality of concave grooves having different depths are formed on the outer peripheral portion, and a spacer member rotatably attached to the support shaft is rotated to select the concave groove portion. And a developer regulating member fitted into the groove portion.

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