JPH0738920Y2 - Development device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a developing device using a one-component developer of an image forming apparatus such as an electrophotographic copying machine, a facsimile, and a printer.

BACKGROUND ART A one-component developing device having a developing roller, a toner supplying means, and a regulating means for regulating the thickness of a toner layer on the developing roller is known.

The conventional regulating blade is arranged in contact with or close to the developing roller to regulate the thickness of the toner layer.

In the regulation blade, there is a problem that a stable contact cannot be obtained with the developing roller due to toner adhesion or dust adhesion, or a stable contact cannot be obtained due to wear, so that the thickness of the toner layer cannot be uniformly maintained. Further, there is a problem that toner leaks at both ends of the developing roller.

It is an object of the present invention to solve the above problems and to provide a developing device in which the contact between the developing roller and the regulating means is secured with stability over time and toner leakage at both ends of the developing roller is prevented. There is.

In order to achieve the above-mentioned object, the present invention is the only restricting means in which sealing members are provided at both ends of the developing roller, are attached substantially perpendicular to the developing roller, and extend in the axial direction of the developing roller. Is made of silicone rubber or synthetic resin, a substance harder than the regulating means is mixed in the developing toner, both ends of the regulating means bite into the sealing member, and the sealing member applies pressure to the regulating means. It is characterized in that it is made of a material having a small reaction force so that it does not fluctuate, and that the thickness of the amount of toner adhered to the developing roller is maintained constant.

The structure and operation of the present invention will be described based on the embodiment shown in the drawings.

Prior to the description of the present invention, an example of a developing and forming apparatus to which the present invention is applied will be generally described.

FIG. 1 shows a laser printer as an example of an image forming apparatus. The recording paper 2 fed from the paper feeding device 1 in the direction of arrow A is composed of a drum-shaped photosensitive member 4 which is timed by a registration roller pair 3. It is conveyed to the latent image carrier.

The photoconductor 4 is rotationally driven in the clockwise direction, the surface of the photoconductor 4 is charged by the charging charger 5, and the laser beam L from the laser optical system 6 is irradiated to form an electrostatic latent image on the photoconductor. This latent image is visualized by the toner as it passes through the developing roller 22 of the developing unit 17, and the visible image is formed by the photoreceptor 4.
The transfer charger 8 transfers the visible image on the recording paper 2 conveyed to the recording paper 2, and the visible image on the transferred recording paper is fixed by the fixing device 9. The recording paper exiting the fixing device 9 is a paper discharge section 11 formed by the upper wall surface of the printer body 10 as shown by an arrow B.
Is discharged to.

On the other hand, the residual toner is removed by the cleaning device having the cleaning blade 12 on the photoconductor portion after the transfer of the visible image, and the static elimination device 13 removes the static electricity. The toner removed from the photoconductor 4 is collected by the impeller 14 in the toner collection chamber 15 and is stored therein.

In the illustrated laser printer, as shown in FIG. 2, the latent image carrier composed of the photoconductor 4 and its related components are configured as one carrier unit 16.
An image forming unit including the developing unit 16 and the developing unit 17 is detachably supported by an image forming unit case 18 separately.
The carrier unit 16 has a box-shaped case 19 as shown in FIGS. 1 to 4, and the support shaft 4a of the photoconductor 4 is rotatably supported by the case 19. Further, a hole 20 through which the laser light from the laser optical system 6 enters is formed in the case 19, and the toner recovery chamber 15 described above is partitioned by the case 19 itself. In addition to this case 19, the charger 5
The static eliminator 13, the impeller 14 and the cleaning blade 12 shown in FIG. 1 are respectively supported, and these constitute a carrier unit 16.

Further, the developing unit 17 includes a main body case 21 containing the toner T, the above-mentioned developing roller 22 opposed to the photoconductor 4, and a thin layer of toner on the developing roller having a uniform layer thickness, as is apparent from FIG. Regulating blade 24 which is a regulating means for regulating the supply roller 23, a supply roller 23 for supplying toner to the developing roller 22, and a body case
The developing roller 22 has an agitator 62 for agitating the toner T in the main body case 21 as shown in FIG.
Is rotatably supported by the supply roller 23 and the agitator.
62 is also rotatably supported by the main body case 21.

The regulation blade 24 is also attached to the main body case 21. Further, a toner cartridge 25 is detachably attached to the main body case 21, and when the toner remaining in the main body case 21 becomes low, the cartridge that has been attached until then
The toner can be replenished to the case 21 by replacing 25 with a new cartridge containing toner.

As is well known per se for the developing operation, the toner T in the main body case 21 is rotated by the supply roller 23 to rotate the developing roller 22.
The toner supplied to the developing roller 22 that rotates in the counterclockwise direction is thinned by the regulation blade 24 and is conveyed to the area where the photoconductor 4 and the developing roller 22 face each other, and the latent image on the photoconductor is electrostatically charged. Shift to the target.

The printer main body 10 is divided into an upper main body 10a and a lower main body 10b, and is configured so that the upper main body 10a can be opened and closed with respect to the lower main body 10b around a hinge (not shown) provided on the back side thereof. There is. In this case, the image forming unit case 18 is provided in the lower portion 10b of the main body, so that the carrier unit 16 and the developing unit 17 also belong to the lower portion 10b of the main body, and when the upper portion 10a of the main body is opened, the upper portions of both units 16 and 17 are exposed. To do. The image forming unit case 18 is supported on the lower portion 10b of the main body so as to be vertically rotatable, and the lower portion 10b of the main body is locked by a locking device.
locked against b

The developing unit 17 is locked to the case 18 by a stopper 29 formed integrally with the image forming unit case 18. This stopper 29 has a stop claw 31 and a knob 30, is made of, for example, a synthetic resin, and is elastically deformable in the direction of arrow C. When the developing unit 17 is housed in the image forming unit case 18, the stopper claw 31 of the stopper 29 engages with the engaging portion 21a formed in the main body case 21 of the developing unit 17,
The developing unit 17 is held. When removing the developing unit 17 for the purpose of maintenance and inspection, or replacement thereof, pull the knob 30 to the right in FIG.
Is elastically deformed in the direction of arrow C to disengage the claw 31 from the engaging portion 21a, and the developing unit 17 is lifted upward. On the contrary, when the developing unit 17 is mounted, the developing unit 17 is lowered from the upper side, the stopper 29 is pressed rightward and elastically deformed, and the claw 31 is engaged with the engaging portion 21a. After the engagement, the stopper 29 elastically biases the developing unit 17 to the left in FIG.

The carrier unit 16 can be attached to and detached from the image forming unit case 18 in the same manner as the developing unit 17.

When the carrier unit 16 and the developing unit 17 are attached to and detached from the case 18, the lower part 10b of the main body and the case 18 are kept in a horizontal state, so that the work can be performed in a comfortable posture.

When the carrier unit 16 is supported by the image forming unit case 18, a part of the photoconductor 4 is an opening formed in the bottom wall of the case 18.
A gear (not shown) which is projected into 61 and is attached to the support shaft 4a also projects into the opening 61, and is driven by meshing with a gear (not shown) supported by the lower portion 10b of the printer main body. Similarly, the gear 63 of the developing roller support shaft 22a and the gears (not shown) of the supply roller 23 and the agitator 62 also engage with the gears on the lower portion 10b side of the main body and are rotationally driven.

Imaging unit case 18 attached to the printer body 10
Each unit 16 and 17 was housed in and was locked by a stopper, but this case 18 is the main body 10, the lower part of the main body in the example of the figure.
Since the units 16 and 17 are correctly positioned and fixed to the unit 10b, the units 16 and 17 can be positioned and set with respect to the main body 10 by locking the units 16 and 17 to the case 18. One end of the developing device 17 is positioned with respect to the image forming unit case 18 by the first supporting member 28a and the second supporting member 28b as shown in FIGS.
The image forming unit case 18 is provided on the other end side of the 17 by the stopper 29.
The developing unit 17 can be properly positioned and set with respect to the image forming unit case 18.

In this example, in order to easily and correctly set the position of the developing unit 17 with respect to the carrier unit 16, the rear pressure spring 33 is provided on the right side wall 18c of the image forming unit case 18 and the developing unit 17 in FIGS. It is stretched between the holding part piece 32 and the holding part piece 32. The pressure spring 33 presses the developing unit 17 to the left in FIG.

At this time, since the support shaft 22a of the developing roller 22 is placed on the upper surface of the horizontal supporting member 28 in a state of being movable in the horizontal direction, when the developing unit 17 is biased to the left, the developing roller 22 is pressed against the photoconductor 4. At this time, since the supporting shaft 4a of the photoconductor 4 is fitted into the groove-shaped supporting portion 27 of the carrier unit 16 and the movement in the horizontal direction is blocked, the developing roller 22 and the photoconductor 4 are arranged in the longitudinal direction thereof. Uniform pressure contact over the entire length. In this way, the photoconductor 4 can be easily and surely
The relative position between the developing roller 22 and the developing roller 22 can be correctly determined, positional accuracy such as parallelism and axial distance between the two can be obtained, and the pressure contact force between the two can be kept within a predetermined appropriate value. This configuration can be adopted even when both the developing roller 22 and the surface of the photoconductor are made of rigid bodies, but when at least one of these is made of an elastic body, this elastic body is appropriately elastically deformed by the pressing force of the spring 33. It is particularly advantageous because the contact area between the two required for development can be maintained at an appropriate size. In addition, even if the photoconductor 4 or the developing roller 22 vibrates to some extent during the operation of the printer,
Since the spring 33 elastically presses the two, the contact area does not change greatly due to vibration, and it is possible to always obtain a high-quality visible image.

Even in a developing device in which the developing roller and the photoconductor are arranged with a predetermined gap, the developing roller is biased toward the photoconductor by the biasing force of the spring 33, etc., and the support shaft of the roller is brought into contact with the stopper to position them. It is possible to As the spring 33, a coil spring, a leaf spring or the like can be appropriately selected.

A biasing means other than the spring 33 may be used, or the pressing force of this biasing means may be directly exerted on the developing unit 17. It is also possible to support the biasing means on the developing unit side.

After holding the carrier unit 16 and the developing unit 17 in the image forming unit case 18 as described above, the main body upper part 10a is closed as shown in FIG. 1 to perform the printing operation. 17 is locked to the image forming unit case 18 by a stopper, but the external force acting on each of the units 16 and 17 causes the units 16 and 17 to move vertically or vibrate with respect to the image forming unit case 18. Can also be considered. If such a situation occurs, the image quality of the visible image formed on the recording paper may deteriorate.
Therefore, in the illustrated printer, the bottom surface of the image forming unit case 18 and the main body frame (hereinafter referred to as the upper frame) 34 of the main body upper portion 10a are made of sponge as shown, rubber, foam, or a compression coil spring. Elastic body
When 35, 36 are attached or attached and the upper part 10a of the main body is closed, the upper frame 34 presses the carrier unit 16 and the developing unit 17 via the elastic body 36, and accordingly, both units 16, 17 are connected. Is elastically pressed against the bottom surface of the image forming unit case 18 via the elastic body 35. As a result, both units 16 and 17 are elastically and firmly held in the vertical direction, and these are fixed to the image forming unit case 18
The inconvenience of moving or vibrating against is prevented or suppressed. When the units 16 and 17 are housed in the image forming unit case 18, and these are locked to the image forming unit case 18 by the stopper 29 and the like, the elastic body 35 moves the units 16 and 17 upward. Since it is urged, it is possible to more securely lock with the stopper. Elastic body 3
5,36 may be provided only between the upper part 10a of the main body and both units 16 and 17, or between these units 16 and 17 and the image forming unit case 18, and the elastic bodies 35 and 36 may be provided to the units 16 and 17, respectively.
Of course, it may be mounted on the 17 side. The configuration using the elastic body can be adopted even when the carrier unit and the developing unit are configured as one unit integrally assembled.

By providing the elastic bodies 35 and 36 as described above, both units 1
It is possible to prevent vertical movement or vibration of 6,17. However, in the illustrated printer, the developing roller 22 rotating counterclockwise rotates at a peripheral speed higher than that of the photoconductor rotating clockwise, so that the developing roller 22 is slanted as indicated by an arrow D in FIG. A strong external force directed upward is received from the photoconductor side. Therefore, it may be difficult to hold the developing unit 17 immovably in the vertical direction only by pressing the main body upper part 10a via the elastic bodies 35 and 36 described above. Therefore, in the illustrated embodiment, a lock lever 37 is provided as a developing unit holding member shown in FIGS.

The lock lever 37 is rotatably attached to the shaft 22a of the developing roller 22. When the developing unit 17 is set in the apparatus, the lock lever 37 is attached by a spring 38 while tilting in one direction.

When the developing unit 17 is set in the apparatus and the upper body 10a is closed, the pressure lever (not shown) attached to the upper body 10a side pushes the portion of the lock lever 37 marked with an arrow in the direction of arrow E. And engages with a stopper 39 fixed to the image forming unit case.

The driving-side side of the developing unit 17 having the gear 23 is held in the vertical position by the engagement of the lock lever 37 and the stopper, and the operating-side side opposite to the driving-side side is the first supporting member 28.
The vertical position is held by a roller as a and a compression coil spring 36 ', sandwiched from above and below. Further, only the lower surface of the central portion of the end portion of the developing unit 17 opposite to the side supporting the developing roller 22 is supported by the roller as the second supporting member 28b.

The first support member 28a and the second support member 28b regulate the position of the developing unit 17 in the main body case 21 in the vertical direction, but allow movement only in a certain range in the horizontal direction. When removing the developing unit 17 from the image forming unit case 18, the lock lever 37 and the compression coil spring are opened by opening the upper part 10a of the main body.
Both 36 'are automatically released and the developing unit 17 can be easily removed.

When the image forming unit case 18 is housed in the mounting position shown in FIGS. 1 and 2, a lock device 57 is provided for the purpose of properly positioning and holding the case with respect to the lower frame 54 of the lower body 10b. There is. The locking device 57 has a rotating member 59 movably supported by a pair of support pins 58 projecting from the image forming unit case 18, and a pair of locking claws 65 and a knob 66 are provided on the member 59. It is formed integrally. Further, a compression coil spring 69 is press-fitted between a receiving portion 67 formed by cutting and bending a part of the rotating member 59 and a horizontally formed portion 68 of the image forming unit case 18, and the compression coil spring 69 is rotated by the spring 69. The member 59 is given a turning habit in the clockwise direction in FIG.

A pair of locking holes 70 are formed in the lower frame 54, and when the image forming unit case 18 is stored in the mounting position shown in FIG. It is engaged by the action of 69. In this case, in the illustrated example, a compression coil spring 71 is provided in the image forming unit case 18 as shown in FIG. 2, and the lower end of the spring 71 is the lever 7 of the lower portion 10b of the main body.
Since it is pressed against 2, the image forming unit case 18 is biased counterclockwise by the spring 71 about the pivot pin 52 when the image forming unit case 18 is housed in the mounting position. Therefore, the lock claw 65 is pressed against the upper wall portion defining the locking hole 70, and the main body case 21 is securely locked and held at the mounting position. It goes without saying that the lock claw may be provided on the lower side of the main body and the locking hole with which the lock claw is engaged may be provided on the image forming unit case 18 side.

When opening the image forming unit case 18, the knob 66 of the rotating member 59 is pulled upward in FIG. As a result, the rotating member 59 rotates around the support pin 58 in the counterclockwise direction, the lock claw 65 is disengaged from the locking hole 70, and the locked state is released. Therefore, the pivot pin 52 does not interfere with the image forming unit case 18. It can be rotated around and opened. When the image forming unit case 18 is rotated again to return to the position shown in FIG. 2 and is pushed into the lower portion 10b of the main body, the locking claws 65 are automatically engaged with the locking holes 70 so that the image forming unit case 18 is formed. Locked. Thus, the image forming unit case 18 can be held by a simple operation.

Instead of rotatably supporting the rotating member of the locking device,
The lock claw may be elastically deformed to be locked and unlocked.

By the way, as described above, the recording paper is fed to the photoconductor 4 with the timing set by the registration roller pair 3. The registration roller pair 3 can be seen from FIG.
It is composed of a drive roller 3a and a driven roller 3b which makes rolling contact with the drive roller 3a. In this case, the drive roller 3a is fixedly supported by the side plate, while the driven roller 3b has its support shaft rotatably supported by the lever 72 shown earlier.
72 is pivotally supported by a pin 80 on the side plate.
When the image forming unit case 18 is held at the mounting position shown in FIG. 2, the above-mentioned spring 71 attached to the image forming unit case 18 presses the lever 72. This allows the driven roller
The driving roller 3a is pressed against the driving roller 3a, and the driving roller 3a cooperates with each other to convey the recording paper. When the image forming unit case 18 is opened, the pressing action of the spring 71 on the lever 72 is released.
Therefore, the lever 72 can be easily swung around the pin 80 by hand, and when the recording paper is jammed between the rollers 3a and 3b, it can be easily removed. It is also possible that the sheet conveying rollers other than the registration rollers are similarly brought into pressure contact with the image forming unit case 18, or the pressure contact can be released.

Although the recording paper passes below the image forming unit case 18, in the illustrated embodiment, attention is paid to this point and the locking device 57 described above is used.
The lower part of the rotating member 59 constituting the above is used as the guide portion 82 of the recording paper. This eliminates the need to provide another independent guide member on the right adjacent part of the image forming unit case 18 to reduce the number of parts, and when the image forming unit case 18 is rotated and lifted, it becomes a jammed paper immediately. There is also an advantage that it can be accessed and the jam paper can be easily processed. For the same purpose, a plurality of ribs 81 arranged in the direction perpendicular to the paper surface of FIG. 2 are provided on the lower surface of the image forming unit case 18 so that the recording paper can be guided.

As described above, the function of the case 18 can be expanded and the number of parts of the image forming apparatus can be increased by pressing the registration roller and releasing the registration roller by the image forming unit case 18, and by configuring the recording paper to be guided. It can be reduced.

In the illustrated embodiment, the image forming unit is divided into a carrier unit and a developing unit, and these are configured so that they can be locked to the main body of the image forming apparatus via the image forming unit case. It is also possible to combine them into one or divide them into three or more parts, and it is also possible to lock the image forming unit directly to the main body without interposing the image forming unit case. Further, instead of rotatably supporting the image forming unit case with respect to the main body, it may be slidably supported, or may be fixedly fixed to the main body. The stopper may be provided on the image forming unit case side, or when the image forming unit case is used, the stopper may be provided directly on the main body of the image forming apparatus.

The present invention can be applied to various image forming apparatuses other than the laser printer, such as a copying machine and a facsimile.

In the developing device according to the present invention, as shown in FIGS. 8 to 9 showing a modification of the developing device in FIG. 2, the toner T supplied is agitated by the agitator 62 and sent to the developing roller 22 by the supply roller 23. And is electrostatically attached. At that time, each roller is rotated in the direction of the arrow, and the supply roller 23 and the developing roller 22 are
Is set to a certain bias potential.

The regulating blade 24 is a guide groove 41a of the holding arm 41 as a regulating means for making the toner layer attached to the developing roller 22 into a uniform thin layer.
Both ends of the
Pressurized by 42. The edge of the regulation blade 24 is in parallel contact with the development roller 22 so that the excess toner on the development roller 22 is scraped off by the regulation blade 24.

The regulation blade 24 is composed of a blade 24a for scraping off toner, a holder 24b for supporting the blade 24a, and a peeling prevention plate 24c attached to the upper portion of the holder 24b.

The holding arm 41 is rotatably supported on the shaft 22a of the developing roller 22 by a bearing 43, and has a positioning portion 41b. The positioning portion 41b is fixed to the main body case 21 by a bolt or the like to position the holding arm 41. The holder 24b is fitted in the guide groove 41a of the holding arm 41.

The blade 24a of the regulation blade 24 is formed longer than the developing roller 22 in order to prevent the toner from falling from the end, and the long portion can contact the seal members 44 attached to both ends of the developing roller 22, and the spring 42 It is configured so that the seal member 44 is difficult to be pushed in by pressure.

The blade 24a was made of a conventional metal, such as stainless steel, but if toner sticks to the blade tip 24d or dust or the like adheres to the toner layer, the toner layer becomes uneven, and the blade does not become a thin layer evenly. Occurred.

In the present invention, the blade 24a is made of silicone rubber such as methyl vinyl polysiloxane or other resin material.

The developing roller 22 is required to have a certain contact width in order to contact the photosensitive member 4 for development. For this purpose the developing roller
An elastic material, for example, a material such as urethane rubber is used for 22, and a film layer of conductive particles is formed on the surface layer.

Some of the developing toner contains hard materials such as blade 24
A toner harder than the material of a and an abrasive such as SiC, SiO ₂ , TiO ₂ are mixed and used for polishing the blade. If necessary, both hard toner and abrasive can be mixed. As a result, even if toner adheres to the blade 24a or dust or the like enters and adheres to the blade 24a, the blade 24a is abraded due to friction with the toner, and can have a self-cleaning property.

For example, according to JIS C 2123, a combination of a silicone rubber blade having a hardness of 65 ° to 95 ° and a toner containing SiC Hv3000 was found to have good self-cleaning property.

The elastic layer of the developing roller 22 is formed of a material that is softer than the blade 24a and the toner and has JIS hardness A type of about 30 °,
When the toner is adhered to the developing roller 22 by the supply roller 23 and the toner layer is regulated by the blade 24a, the blade 24a is abraded by the hard toner in the toner or the abrasive, and the toner adhesion amount on the developing roller 22 is stable for a long time. In this state, the layer thickness can be regulated to a uniform layer thickness.

The spring 42 that pressurizes the regulating blade 24 is set so that the developing roller 22 presses the tip 24d of the blade 24 at a uniform pressure, thereby ensuring an appropriate toner adhesion amount.

The proper amount of toner adhesion 0.4mg / cm ² ~0.5mg / cm ² is selected, the image density, problems such as scumming occurs at a coverage other than these. The proper amount of adhesion is the blade 24a and the developing roller 2
In addition to the combination of 2 and the above conditions of toner, pressurization amount is 24 to 3
It is necessary to select 6gf / cm.

It is possible that toner does not exist on the developing roller when the developing roller 22 starts rotating. At this time, since the coefficient of friction between the developing roller 22 and the blade 24a is very high, the tip portion 24d of the blade 24a is pulled by the developing roller 22 in the rotational direction by frictional force, and is permanently deformed to the tip portion 24d of the blade 24a. Cause For example, the blade 24a having the shape as shown in FIG. 11 (a) at first is deformed as shown in FIG. 11 (b). This deformation does not necessarily extend over the entire length of the blade 24, but causes partial deformation. This deformation causes unevenness in the thickness of a thin layer of toner on the developing roller 22, resulting in uneven density on the image.

When toner intervenes between the developing roller and the blade 24a, the friction coefficient becomes low, and therefore such development does not occur.
Blade to solve the problem when this toner is not
An appropriate amount of fine powder of polyvinylidene fluoride, SiC, or SiO ₂ is applied to the tip portion 24d of 24a in advance. As a result, even when there is no toner, it becomes possible to reduce the friction coefficient and torque when the toner is present. For reference, an example of the friction coefficient and the magnitude of the developing roller torque with and without the toner is shown in Table 1. The developing roller torque is a torque that also includes other load factors.

Both ends of the blade 24a are pressed by the spring 42 so that the seal member 44 is difficult to fit into the seal member 44. Therefore, as the rotation of the developing roller 22 progresses, wear of the tip end portion 24d of the blade 24a progresses, but only the both end portions are seal members. Since it cuts into 44, it remains without being worn. Since the seal member 44 is adhered to the holding arm 41, both side end portions of the blade 24a further bite into the seal member 44 as time passes. Therefore, it is convenient that the seal member 44 is made of a material that is sufficiently softer than the developing roller 22 and has a small reaction force to the extent that the pressure applied by the spring 42 to the blade 24a does not change. Furthermore,
The blade 24a is also made of a material that is soft and maintains the sealing property in a distorted place. As the material, for example, rubycell made of Toyo Polymer, polyvinyl alcohol, soft urethane foam, polyethylene sintered body, foam such as rubber sponge are preferable. This made it possible to achieve both uniform wear of the blade and toner sealability at the edges. Seal member
One 44 may be arranged at each end of the developing roller 22, but it can be arbitrarily deformed depending on the shape of the holding arm 41 and the like. In FIG. 10, the seal member 44 is a ring-shaped seal member 44a attached to the boss-shaped portion of the holding arm 41, a seal member 44b in contact with the end portion of the developing roller 22, and bonded on the ring-shaped seal member 44a. The sealing member 44b is bonded to the holding arm 41 by, for example, a double-sided tape 44d or the like.

Effect According to the present invention, since the seal member is in contact with both ends of the developing roller and the regulating means, toner leakage can be prevented. Also, since a soft member is selected as the seal member, even if the portions of the regulating member that contact the developing roller are worn and the non-abraded portions of both ends are not worn, the sealing member is pushed into the sealing member, so Even when worn, the developing roller always comes into contact with the developing roller in a stable state, and a sufficient sealing effect against toner leakage can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an example of an image forming apparatus to which the present invention is applied, FIG. 2 is a sectional view of an image forming main portion, FIG. 3 is a sectional view illustrating a unit structure of the image forming portion, and FIG. Is a perspective view showing a state where the unit is disassembled, FIG. 5 is an external perspective view of the developing device, FIG. 6 is a side view of the developing device, FIG. 7 is a side sectional view of the developing device, and FIG. 8 is a developing device. Front sectional view, FIG. 9 is an exploded perspective view showing the relationship between the developing roller and the regulating blade, FIG. 10 is a side sectional view of FIG. 9, FIG. 11 is a view showing deformation of the blade, and FIG. FIG. 11b is a diagram showing the state after deformation. 22 …… Developing roller 23 …… Supply roller (toner supplying means) 24 …… Regulating blade (regulating means) T …… Toner

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-59943 (JP, A) JP-A-63-180984 (JP, A) Actual development: Sho-61-29361 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A one-component developing device containing a developing roller, a toner supplying means, and a regulating means for regulating the thickness of a toner layer on the developing roller, wherein a seal member is provided. The only restricting means that are arranged at both ends of the developing roller, are attached almost vertically to the developing roller, and extend in the axial direction of the developing roller are made of silicone rubber or synthetic resin. A hard substance is mixed in the developing toner, and both ends of the regulating means bite into the seal member,
The seal member is made of a material having a small reaction force to the extent that the pressure applied to the regulating means does not fluctuate, and the thickness of the amount of toner adhered to the developing roller is kept constant. .