JPH04465A - Developing device - Google Patents

Abstract

PURPOSE:To obtain a developing device in which cleaning and inspection are easily performed and an elastic blade is easily restored without complicated adjusting work by attaching the elastic blade between a position where it press-contacts with a developing roller and a position where it separates from the roller so that it can rock. CONSTITUTION:The elastic blade 41 is in press-contact with the developing roller 11 and the base part thereof on a side opposite to the press-contact part with the roller 11 is attached to a supporting member 42 with adhesion, and both ends of the member 42 are supported by hinges 43 so as to be able to rock up and down. Then, the member 42 is constituted so that it may be energized to rock in a direction where the blade 41 press-contacts with the roller 11 by a proper energizing means 45 lying between the hinge 43 and the member 42, and the rocking end may be regulated by stopper 46 to stop at a position where specified press-contact force acts. In the case of replenishing developer with such constitution, the blade 41 is allowed to rock upward with the member 42 by resisting the means 45 to separate from the roller 11, so that the cleaning and the inspection of the blade 41 are easily performed. By quietly restoring the blade 41 to an initial state at the time of finishing, the blade 41 is in pres- contact with the roller.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developing device used in an image forming apparatus such as a copying machine, facsimile machine, or printer that forms an image by electrophotography.

BACKGROUND ART Conventionally, a developing device used in the above-mentioned image forming apparatus has a magnetic brush formed on the outer peripheral surface of a developing roller to hold toner, and this magnetic brush is brought into contact with an image bearing member on which an electrostatic latent image is formed. A commonly used device is one in which the toner is electrostatically attracted to the electrostatic latent image and developed.

However, in the case of forming this magnetic brush, the structure of the developing roller is complicated and the cost is high.
A one-component non-magnetic developer is used, and this developer is triboelectrically charged with a charging means such as a fur brush and carried on the developing roller.The developer carried on the developing roller is transferred to the developing roller using an elastic blade. A developing device has been proposed in which a layer is pressed onto a surface and further triboelectrically charged to thin the layer to a predetermined thickness, and then subjected to development.

In addition, in order to eliminate the need for maintenance of the image carrier and the developing device, an image forming apparatus is provided with an image forming cartridge that integrates at least the image carrier and the developing device, and which is detachably attached to the main body of the device. However, for example, JP-A-27154225 and JP-A-61-2798
It has been known from the prior art, for example, in Japanese Patent No. 70, and it is also known to use a developing device configured using an elastic blade as described above.

Problems to be Solved by the Invention However, in the developing device using the above-described elastic blade, unless the elastic blade is cleaned and inspected at predetermined intervals and replaced as necessary, stable high quality cannot be achieved. I can't get the image. However, conventionally, the elastic blade is fixedly installed in pressure contact with the developing roller, so when performing cleaning or inspection, the elastic blade must be completely removed, cleaned, etc., and then fixedly installed again. There was a problem in that it was necessary to make delicate adjustments to the mounting position, which was time-consuming.

In addition, in the developing device of the image forming cartridge, the above problem did not occur because the image forming cartridge was traditionally disposable because it was maintenance-free, but in recent years, image carriers with a long lifespan have become relatively simple. However, it is still relatively expensive in terms of cost, and from the perspective of making the developer casing compact and downsizing the image forming cartridge, it is necessary to make the image forming cartridge not disposable. It is conceivable to replenish the developer, but in that case, the problem is that cleaning and inspection of the elastic blade is difficult as described above.

Therefore, the present invention provides a developing device in which a thin layer of developer is held on a developing roller by an elastic blade.
An object of the present invention is to provide a developing device that allows easy cleaning and inspection of an elastic blade.

Means for Solving the Problems In order to achieve the above-mentioned problems, the present invention has a method in which an elastic blade is brought into pressure contact with the outer peripheral surface of a developing roller supplied with developer to hold the developer in a thin layer. In a developing device that develops by electrostatically attracting developer to an electrostatic latent image formed on an image carrier that moves close to the outer peripheral surface of the developing roller, the position where the elastic blade is pressed against the developing roller. The device is characterized in that it is mounted so that it can swing between the two positions.

Function: In the above structure of the present invention, the elastic blade is attached so as to be able to swing between a position where it is in pressure contact with the developing roller and a position where it is separated from the developing roller. Cleaning, inspection, etc. can be easily carried out by swinging it to this position, and it can then be easily returned to a predetermined pressure contact position without any complicated adjustment work.

EXAMPLE A developing device as an example of the present invention shown in FIGS. 1 to 6 will be described below.

FIG. 1 shows an image forming cartridge 1 equipped with a developing device according to the present invention. As shown in the figure, this cartridge I is formed by connecting a developer casing 2 and a waste toner casing 3. A photosensitive drum 4 is provided at the connecting end of the waste toner casing 3 and is pivotally supported on the side wall of the waste toner casing 3 by a shaft 6. A cleaning blade 7 is brought into pressure contact with the back of the photosensitive drum 4, and residual toner scraped off from the top of the photosensitive drum 4 is stored in the waste toner casing 3. To accommodate this, a paddle 8 is provided near the bottom of the waste toner casing 3 behind the photosensitive drum 4 to scrape the toner scraped from the photosensitive drum 4 into the waste toner casing 3. The photosensitive drum 4 has a photoconductive layer made of zinc oxide, selenium, organic photoconductive material, etc. formed on the surface of a metal base such as aluminum, and forms an electrostatic latent image by imagewise exposure.

A developing roller 11 for developing an electrostatic latent image on the photosensitive drum 4 with toner is provided at the connecting end of the developing device casing 2 and is pivotally supported by a shaft 12 on a side wall. A sponge roller 13 is provided on the back of the developing roller 11 and is pivotally supported on the side wall of the developing device casing 2 by a shaft 14, which charges the developer and supplies it to the developing roller 11. A developer supply paddle 15 is provided inside the developer casing 2 and is pivotally supported on a side wall by a shaft 16 for stirring the developer in the developer casing 2 while supplying it to the sponge roller 13 . The shaft 16 is equipped with stirring blades 17 to prevent toner from forming into blocks.
is installed.

A wire 82 for scraping off the developer is provided on the back of the sponge roller 13. This wire 82 is stretched between the opening edges of a partition plate 95 in the developer casing 2 and is pressed against the back surface of the sponge roller 13. As a result, when the residual developer that has been supplied to the developing roller 11 on the sponge roller 13 returns to the back side of the sponge roller 13, this residual developer is scraped off from the surface of the sponge roller 13 by the wire 82. Returned to unused developer. Therefore, the residual developer that remains after being supplied to the developing roller 11 does not leave the surface of the developing roller 11 and is repeatedly supplied to the developing roller 11 as it is, or is scraped off once from the surface of the developing roller 11. This prevents the developer from being captured by the sponge roller 13 and supplied to the developing roller 11 without being mixed with unused developer. For this reason, the sponge roller 13
It is possible to prevent the stress of the residual developer that was not supplied to the developing roller 11 from affecting the developing characteristics.

The developer casing 2 and the waste toner casing 3 are connected to the shaft 2.
Positioning rollers 23 and 24 provided on the shafts 6 and 12 of both the photosensitive drum 4 and the developing roller 11 are connected to each other so as to be swingable by the shafts 6 and 1 of the photosensitive drum 4 and the developing roller 11.
They are brought into pressure contact with each other, and a predetermined gap is maintained between the photosensitive drum 4 and the developing roller 11 while absorbing manufacturing and assembly errors of each part.

A lid 3o is attached to an upwardly opened developer input port 83 of the developer casing 2, and is fixed to the developer casing 2 by an appropriate method such as adhesion, welding, or screwing. The lid 3o extends to the waste toner casing 3 and covers the waste toner casing 3, making it easy to handle the image forming cartridge I as an integral part. In particular, the lid 30 is heavier than the waste toner casing 3 and is fixed to the side of the larger developer casing 2 to serve as the gripping portion H for integral handling, so that the stability of the image forming cartridge 1 during handling is improved. This makes it easier to handle. Note that there is provided an amount of play between M2O and the waste toner casing 3 that does not impede the necessary rocking of the waste toner casing 3 relative to the developer casing 2 due to pressure contact between the positioning rollers 23 and 24. Also, input port 8
3, a developer replenishment port (not shown) is provided on the side of the developer casing 2 and is closed with an opening/closing lid that cannot be opened or closed by the user.
The work of collecting the developer and replenishing the developer can be easily performed.

Further, a seal vi25 is provided at the bottom of the connecting end opening of the developer casing 2 and extends to the circumferential surface of the developing roller 11 and comes into pressure contact with it, and a photosensitive drum is provided at the bottom edge of the connecting end opening of the waste toner casing 3. A sealing plate 26 is provided which extends up to 4 and presses against it. As a result, the developer handling space of the image forming cartridge 1 formed by the developer casing 2 and the waste toner casing 3 becomes almost sealed, thereby preventing the developer from scattering to the outside. I can do it.

Note that the sealing performance can be further improved by providing the seal plates 25 and 26 in the developer casing 2 and the waste toner casing 3 in multiple stages as necessary, and pressing them against the surfaces of the developing roller 11 and the photosensitive drum 4 in multiple stages in their rotational directions. improves.

This image forming cartridge 1 is used by being attached to a printer 31 shown in FIG. 6, for example. In this printer 31, an upper frame 33 can be opened and closed vertically about a hinge shaft 34 with respect to a lower frame 32, and the image forming cartridge 1 is mounted on the upper frame 33 as shown in FIG. This attachment is performed detachably from the rear of the upper frame 33 that opens upwardly along guides (not shown) provided inside both side walls of the upper frame 33. When the upper frame 33 of the image forming cartridge 1 is closed with respect to the lower frame 32,
Transfer charger 3 provided on the lower frame 32 side
6, and when the upper frame 33 is opened upward as shown in FIG. 6, the paper passing path 37 is opened, making troubleshooting such as jams easier. .

A laser scanning unit 38 is provided above the portion of the upper frame 33 where the image forming cartridge 1 is mounted. This laser scanning unit 38 deflects a laser beam 39 from a laser emitting source modulated according to an image signal provided by a personal computer, an image reader, etc., using an appropriate scanning means such as a polygon mirror, and scans the photosensitive drum 39. Image exposure is performed on the photosensitive drum 4 toward the image. For this image exposure, the image forming cartridge 1 is provided with an exposure sling 1-51 on a part of the lid 30, which enables image exposure to the photosensitive drum 4.
Inside, an electrostatic latent image is formed by image exposure.
A charger 52 is provided in front of the image exposure position of the photosensitive drum 4 to uniformly charge the surface of the photosensitive drum 4.

However, due to recent miniaturization and weight reduction, the thickness of each member forming the image forming cartridge 1 tends to become thinner and the rigidity tends to decrease. Therefore, when handling the image forming cartridge 1 alone, an external force for gripping the image forming cartridge 1 acts on the developing device casing 2 forming the grip part H of the image forming cartridge 1, causing temporary deformation such as twisting or denting. It may also occur. At this time, the volume of the developer casing 2 momentarily decreases, and the developer may be blown out along with the internal air from the weak portion of the seal.

Therefore, in this embodiment, an opening 84 is formed in the lid 30, and the opening 84 is closed with a semipermeable membrane 85. The semipermeable membrane 85 is one that allows air to pass through but does not allow the developer to pass through. As a result, even if the developer casing 2 is deformed as described above during handling of the image forming cartridge 1 and the volume is reduced and internal air is blown out, the semi-permeable membrane 85 with less resistance prevents the air from blowing out. Even if the developer tries to get onto the blown air, the semi-permeable membrane 8
5 to prevent it from spewing out to the outside. Such a structure can be applied to the waste toner casing 3 as well, if necessary.

As shown in detail in FIGS. 2 and 3, an elastic blade 41 is pressed against the developing roller 11. As shown in FIGS. As the elastic blade 41, a rubber blade made of urethane rubber, silicone rubber, or the like, or a metal blade made of spring-use phosphor bronze, spring steel, or the like is useful. The base of the elastic blade 41 on the side opposite to the part in pressure contact with the developing roller 11 is attached to a metal support member 42 by adhesive or the like, and both ends of the support member 42 are supported by hinges 43 so as to be able to swing up and down. There is. This hinge 43 is fixed to both side walls of the developer casing 2 via brackets 44. Further, the support member 42 is connected to the hinge 4
3, the elastic blade 41 is urged to swing in a direction in which it comes into pressure contact with the developing roller 11, and the end of the swing is regulated by a stopper 46, so that a predetermined pressure contact is achieved. It is configured to stop at the position where a force is applied.

With this configuration, when collecting the image forming cartridge 1 and replenishing developer into the developer casing 2, the elastic blade 41 is swung upward together with the support member 42 against the biasing means 45. By moving the elastic blade 41 away from the developing roller 11, cleaning and inspection of the elastic blade 41 can be easily performed, and by gently returning the elastic blade 41 to its original position when the work is completed, the elastic blade 41 can be moved to a predetermined position on the developing roller 11. It comes into contact with the position in a predetermined pressure state.

Incidentally, the developing roller 11 has a developer carrying area X on the central side in the longitudinal direction formed with a satin surface by sandblasting or the like, which is advantageous for carrying the developer. Both ends of the developing roller 11 on both sides of the developer carrying area be. For this reason, the developer non-carrying area Y is kept as a smooth surface to avoid carrying the developer.

As a result, the developer carrying area X of the developing roller 11 has a satin-like unevenness formed on its surface, and the convex portion rises from the surface of the fabric, so that the diameter thereof is slightly increased compared to the developer non-carrying area Y. In addition, since the developer carrying area X of the developing roller 11 carries the developer supplied from the sponge roller 13, although the developer is thinned to a predetermined layer thickness by pressure contact with the elastic blade 41, the developing roller The diameter of the developer carrying area X portion of No. 11 is further increased. Therefore, there is a slight difference in diameter between the developer carrying area X of the developing roller 11 and the diameter of the developer non-carrying area Y, and there is a gap between the developer carrying area X and the developer non-carrying area Y of the developing roller 11. Step Z (
Figure 3).

Therefore, if the elastic blade 41 is uniformly and continuously pressed over the entire length of the developing roller 11, floating will occur between it and the developer carrying area Y, which does not carry any developer and has a small diameter. , causing the developer to leak forward.

In order to solve this problem, in this embodiment, a notch 86 cut from the tip is formed in the portion of the elastic blade 41 facing the boundary K between the developer carrying area X and the developer non-carrying area Y of the developing roller 11. is forming. As a result, the elastic blade 41 can move the developer carrying M1tiX of the developing roller 11,
Each portion 41a, 41b on the longitudinal center side facing each portion of the developer non-carrying area Y and on both sides thereof has a cut 86.
The parts 41a and 41b are separated by the developer carrying area
Since it comes into pressure contact with the developer non-carrying area Y individually, even if there is a step Z between these areas Regardless of the portion 41a, it can be brought into close contact with the developer non-carrying area Y as shown in FIG. Therefore, it is possible to solve the problem that the elastic blade 41 is lifted from the developing roller 11 in the developer non-carrying area Y of the developing roller 11 and the developer leaks from the developer non-carrying area Y to the photosensitive drum 4 side. can.

Further, the elastic blade 410 portion 41b is attached to the support member 42.
It is held down by presser metals 57 attached to both ends of the plate, and the lifting is more strongly prevented. Developing roller 1
A sealing material 88 is interposed between 1 and the side wall 87.

In addition, in a long continuous portion of the elastic blade 41 in the longitudinal direction, the pressure contact with the developing roller 11 tends to be stronger in the central portion of the continuous range than in other portions, and the developer formed on the developing rotier 1 The layer thickness tends to be non-uniform in the axial direction of the developing roller 11, causing uneven development characteristics. Therefore, in this embodiment, in order to solve this problem,
A groove 81 as shown in FIGS. 1 and 2 is formed on the back surface of the elastic blade 41. This groove 81 is located approximately at the center in the width direction of the elastic blade 41, and is formed in a range excluding both ends of the portion 41a between the long cuts 86 of the elastic blade 41.

This allows the long portion 41a of the elastic blade 41 to
The bending rigidity at the central portion in the longitudinal direction is weakened by the concave groove 81, the pressing force against the developing roller 11 is reduced, and the pressing force of the entire long portion 41a of the elastic blade 41 against the developing roller 1 is reduced. become even.

Furthermore, stress is concentrated in the concave groove 81 portion of the elastic blade 41, and by equalizing the stress in other portions, the pressing force against the developing roller 11 can be made uniform.

Therefore, a thin layer of developer can be formed with a uniform layer thickness over the entire developer carrying area X of the developing roller 11, and uniform development characteristics can be expected over the entire developer carrying area X of the developing roller 11.

In addition, the elastic blade 41 is made of polyethylene terephthalate (
If it is formed by punching from a sheet such as PET, the cost will be lower than when a molded product such as urethane foam is used. In this case PET
Since it is made of a strong material, it does not damage the developing roller 11 or cause chattering, and it is preferable to press the developing roller 11 at the so-called abdomen in order to avoid contact with the tip edge.

Furthermore, since the elastic blade 41 is made of an insulating material, the frictional charging between the developer and the elastic blade 41 can be increased, and the overall charging state can be sufficiently stabilized. In this sense, forming a coating layer of an insulating material on the surface of the developing roller 11 can further improve the charging characteristics. Furthermore, since the insulating coating layer can form a satin surface during resin molding without sandblasting, the cost of the boundary image roller 11 is reduced accordingly, and the developer can be transported to areas where the electric field is not diffused. At the same time, the gap between the developing roller 11 and the photosensitive drum 4 can be shortened beyond the discharge limit.
Resolution in development is improved.

In addition, as another example, a speed change mechanism is provided in the drive system of the developing roller 11, and when forming the type of image to be formed, for example, an image with poor reproducibility such as a line drawing or a dot image, the developing roller
If the rotational speed of the developer is increased to increase the amount of developer supplied, the reproducibility of even line drawings and dot drawings will be improved.

In this embodiment, the configuration of the charger 52 is devised in response to the fact that the photosensitive drum 4 is designed to have an extremely small diameter. The photosensitive drum 4, which has an extremely small diameter, faces the charging charger 52 on a curved surface with a sharp degree of curvature, and it is difficult to perform stable charging due to the influence of higher speeds. Therefore, the charger 52 connects the mesh of the grid section 53 to the photosensitive drum 4.
It is arranged so that it gradually becomes finer from the upstream side to the downstream side in the direction of rotation (Fig. 1, Fig. 4). As a result, the charger 52 is initially a corotron-type charger without prints or a similar charging characteristic to ensure charging performance for the rotating photosensitive drum 4, and then a scorotron-type charger with a grid. This ensures controllability of charging by exhibiting charging characteristics as described above.

This makes it possible to achieve stable charging by ensuring both charging performance and charging controllability.

Although the charger 52 is formed into one for miniaturization, two chargers, a corotron type charger and a scorotron type charger, may be installed. Further, the size of the mesh may change continuously or discontinuously. The charger 52 has a grid portion 53 for miniaturization.
and a discharge stabilizing frame 54 are integrally formed from a metal plate. The corona wire 55 is installed between resin blocks 56 attached to both side walls of the developer casing 2.
This resin block 56 holds the end of the discharge stabilizing frame 54.

Note that the corona wire 55 has a wire diameter of about 80 μm, which is extremely thin, so there is a problem with elongation and cutting, which makes it troublesome to handle during installation, and maintenance such as cleaning when it becomes dirty due to use is also troublesome. Therefore, it is conceivable that a metal plate is buried in a resin base (not shown) by insert molding or the like, and a part of the buried metal plate is exposed to be used in place of the corona wire. In this case, costs can be reduced and the strength of the corona electrode portion is improved, making assembly and cleaning easier. Alternatively, a predetermined metal material may be printed in a line shape on the surface of the resin base to serve as a substitute for the corona wire. In this case as well, the same effects as the above improvements can be expected.

Further, the discharge stabilizing frame 54 can also be formed by applying metal plating to the inner surface of the resin housing. In this case, the resin housing can be integrally formed with a part of the existing member such as the lid 30, and the structure can be simplified.

When the upper frame 33 is closed on the lower frame 32, the transfer charger 36 faces the photosensitive drum 4 of the image forming cartridge 1 with a certain gap, and is connected to the paper passing path 37.
The developed toner image formed on the photosensitive drum 4 is transferred onto the transfer paper 9I by working from the back side of the transfer paper 9I being conveyed.

In addition, in the case of the transfer charger 36, the same improvement as that of the charging charger 52 can be made for the corona wire.

A timing roller pair 61 is provided in front of the transfer section of the paper passing bus 37, as shown in FIG. The timing roller pair 61 temporarily stops receiving the transfer paper 91 picked up and fed from the paper feed cassette 92 by the pickup roller 93 in a stopped state, and thereafter feeds the transfer paper 91 at a predetermined timing, and then feeds the transfer paper 91 to the photosensitive drum. The leading edge is aligned with the toner image formed on 4 and used for transfer.

A pair of fixing rollers 62 is provided behind the transfer section, and heat fixes the transfer sheet fed after the transfer.

The surface of the photosensitive drum 4 after the transfer is cleaned by a cleaning blade 7 to remove residual toner.

An eraser lamp 63 is provided immediately after the transfer charger 36 of the lower frame 32, and irradiates erase light onto the surface of the photosensitive drum 4 after transfer through the transfer paper 91 that is being passed, thereby eliminating any residue on the surface of the photosensitive drum 4. Remove charge. Near this eraser lamp 63, there is a light receiving end 65a of the optical fiber halo 5.
is positioned facing the photosensitive drum 4. The optical fiber 65 guides reflected light when the toner image formed on the photosensitive drum 4 is illuminated by the eraser lamp 63 to a density sensor 64 provided at an appropriate position. As a result, the concentration sensor 64 is activated by the eraser lamp 6.
3 for illuminating the image to be inspected, and by using the eraser lamp 63 in common and using the optical fiber 65, the toner image can be detected without requiring any special space around the transfer section. The concentration can be detected, and the cost can be reduced because the eraser lamp 63 is shared.

By sending the detected density of the toner image to the control system, it is possible to determine whether there is a shortage or deterioration of the developer, and to take measures such as warning of the usage limit due to the life of the image forming cartridge 1 or stopping printing.

Note that if the eraser lamp 63 is installed within the discharge stabilizing frame of the transfer charger 36, further space saving can be achieved.

Furthermore, the cleaning blade 7 can be formed of a transparent resin material and used as a light guide to irradiate the surface of the photosensitive drum 4 with eraser light. According to such an erase method, the degree of freedom in selecting the installation location of the eraser lamp 63 increases. Furthermore, cleaning blade 7
Similarly to the elastic blade 41, a concave groove can be formed on the back of the blade to equalize the pressing force. In this case, the resonant frequency of the blade can be easily selected.

Furthermore, the waste toner casing 3 can be formed by punching out a PET sheet to reduce costs, and the waste toner casing 3 is provided with an unused detection mechanism 71 that is linked to the drive system, as shown in FIG. . This unused detection mechanism 71 is a gear 73 provided on one shaft of the drive system, for example, the rotating shaft 72 of the paddle 8 for scraping in waste toner.
The detection gear 74 is engaged. The detection gear 74 has teeth 75 only on a part of the outer periphery, and the other part of the outer periphery is a cam surface 77 having a recess 76 in a part. The waste toner casing 3 also includes a detection pin 78 facing the cam surface 77.
is held movably forward and backward, and this detection pin 78 is brought into contact with the cam surface 77 by a spring 79. When the image forming cartridge l is not in use, that is, when the drive system has never been operated and no developer is consumed, this abutting position is set a predetermined amount downstream from the recess 76 of the cam surface 77 in the driving direction. It is a remote location.

When the image forming cartridge 1 is installed in the printer 31 and is driven and used even once, the gear 7 that is interlocked with the drive is activated.
3 rotates the detection gear 74. The concave portion 76 of the cam surface 77 faces the detection pin 78 by an amount of rotation that is extremely small compared to the amount of drive required for use. At this opposing position, the detection pin 78 is fitted into the recess 76 by the force of the spring 79.

The detection pin 78 protrudes outside the waste toner casing 3 when the image forming cartridge 1 is not in use, and when the image forming cartridge 1 is mounted on the upper frame 33, the switch 94 provided on the upper frame 33 is activated. It is pushed by the detection pin 78 and automatically detects that the imaging cartridge 1 is unused. This detection signal is sent to the control system of the printer 31 to start counting the number of prints using the image forming cartridge and to issue a restriction or warning against use of more than a predetermined number of prints based on this count. Conversely, if the image forming cartridge 1 to be installed has already been used, the detection pin 78 is retracted toward the waste toner casing 3, so even if the image forming cartridge 1 is installed in the upper frame 33, Switch 94 cannot be pressed. Therefore, no action is taken as would be the case when the unused waste toner casing 3 is attached.

However, the usage status can also be detected at the necessary time. For example, by detecting the point in time when a predetermined number of sheets, such as 500 sheets, have been used and using this as a use start signal, it is possible to support test use of up to 500 sheets. Furthermore, it can be said that the point in time when the image forming cartridge 1 has been used for printing the maximum number of sheets for use is detected and a warning is given for further use.

Effects of the Invention According to the present invention, since the elastic plate is attached so as to be able to swing between a position where it is in pressure contact with the developing roller and a position where it is separated from the developing roller, the elastic blade can be moved away from the developing roller when performing cleaning, inspection, etc. By swinging it to a separated position, cleaning, inspection, etc. can be easily performed, and after that, it can be easily returned to a predetermined pressure contact position without complicated adjustment work.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an image forming cartridge equipped with a developing device according to an embodiment of the present invention, FIG. 2 is a perspective view showing a developing roller section, and FIG. 3 is an enlarged front view of a part of the developing roller section. Fig. 4 is a partially enlarged cross-sectional view of the charging charge, and Fig. 5 is a waste toner casing showing the unused detection mechanism of the image forming cartridge.
FIG. 6 is a front view showing a schematic configuration of a printer in which the image forming cartridge shown in FIG. 1 is used. 4-------1・1 t---------------・41-------
−−−−−−−1・ 42−−−−−−・

Claims (1)

[Claims] (1) An elastic blade is pressed against the outer peripheral surface of the developing roller supplied with developer to hold the developer in a thin layer, and the developer is moved close to the outer peripheral surface of the developing roller on the image carrier. A developing device which develops an electrostatic latent image formed by electrostatic attraction thereon, characterized in that an elastic blade is mounted so as to be swingable between a position in pressure contact with the developing roller and a position away from the developing roller. developing device.