JPH0450978A - Developing device - Google Patents

Abstract

PURPOSE:To prevent leaking or excessive feeding to a developing roll of developer by automatically closing a shutter member and preventing the developer from going inside a developing mechanism when the developing device is not loaded to the device main body. CONSTITUTION:A shutter member 18 is pushed down by a spring 19 when an image formation cartridge 1 is being transported, a developer feeding opening 5 is closed, and the developer is sealed inside a developer containing part 9 and is not entered into the developing mechanism part 10. Furthermore, even in the middle of use with the image formation cartridge 1 loaded, if an upper part frame 33 is opened in the upper direction, the toner feeding opening 5 is closed. Thus, the leaking of toner to the outside and excessive feeding of toner to a developing roll 11 can be surely prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developing device that is detachable from the main body of an image forming apparatus such as a copying machine, facsimile machine, or printer that forms images using an electrophotographic method.

2. Description of the Related Art As described above, it is well known that a developing device containing a predetermined amount of developer is attached to the main body of the device, and the developing device is replaced when the developer runs out. Furthermore, an image forming cartridge that integrates two or more image forming means such as an image bearing member and a developing device can be attached to and removed from the main body of the apparatus, thereby eliminating the need for maintenance of these image bearing members and developing devices. The forming apparatus is also disclosed in, for example, JP-A-57-154255 and JP-A-61-279.
This has been known from the prior art, such as in Japanese Patent No. 870. In the image forming cartridge, in order to eliminate the need for maintenance as described above, a predetermined amount of developer corresponding to the life of the image carrier is stored in a developer storage section in advance.

In the developing device and the developing device of the image forming cartridge, the developing roller is arranged close to the image carrier facing the paper passing path, so a part of the developing roller also faces the external space. Appropriate sealing means is provided around the exposed portion of the developing roller to the external space to prevent the developer from leaking outside.

However, since the developing device and the image forming cartridge are handled roughly during transportation, there is a risk that the developer previously stored inside may leak out through the sealing means around the developing roller. To prevent this, conventionally, the outside of the exposed portion of the developing roller was sealed with a seal tape or the like to prevent the developer from leaking out.

Problems to be Solved by the Invention However, when sealing tape is used as described above, it is strongly fixed with adhesive or the like, so it is not easy to remove it, which is time consuming and troublesome. There are problems such as the risk of getting your hands dirty during the process. Also, if the developing device or image forming cartridge is installed in the main body of the device and then removed midway through, depending on how it is handled, too much developer may get into the area around the developing roller, resulting in oversupply of developer to the forming image roller. In addition, the upper frame is tilted diagonally upward to open the paper passage path, and the upper frame does not have a developing device or an image forming device. When installing a cartridge, there is a risk that when the upper frame is opened, excessive developer may enter around the developing roller, causing a similar problem.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a developing device that can reliably prevent leakage of developer and excessive supply to a developing roller without requiring much effort.

Means for Solving the Problems In order to achieve the above-mentioned problems, the present invention provides a developing device that is detachable from the main body of an image forming apparatus.
A developer storage section and a developing mechanism section that forms a thin layer of developer on the outer peripheral surface of the developing roller are separated, and a developer supply port is opened between the developer storage section and the development mechanism section. A shutter member for opening and closing is provided, and a means for biasing the shutter member to close is provided, and the shutter member is opened against the biasing means when it is attached to an apparatus main body set in a state capable of image formation. It is characterized by providing means.

Operation With the above structure of the present invention, when the developing device is transported, when the developing device is taken out from the main body of the device, and furthermore, when the upper frame is opened in the case of a device main body configured to open the upper frame diagonally upward, etc. When the developing device is not attached to the main body of the device that is set to be ready for image formation, the shutter member is automatically closed by the biasing means and the developer in the developer container is supplied. Since the developer is prevented from entering the developing mechanism through the opening, even if the developer is handled roughly during transportation or installation/removal, or when the upper frame is opened, developer will still leak outside through the gap around the developing roller. It is possible to reliably prevent developer from leaking into the developer or from being supplied in excess to the developing roller.

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 1 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.

The developing mechanism section 10 on the connecting end side of the developing device casing 2 includes:
A developing roller 11 for developing the electrostatic latent image on the photosensitive drum 4 with toner is provided, and is pivotally supported by a shaft 12 on the side wall. A fur brush 13 is provided on the back of the developing roller 11 and supplies the developer to the developing roller 11 while charging it.
It is pivotally supported on the side wall of the developer casing 2 by a shaft 14 .

A partition plate 95 is provided on the side opposite to the connecting end of the developer casing 2.
A developer storage section 9 is provided separated from the developing mechanism section 10 at. A developer supply port 5 provided in a partition plate 95 is provided inside the developer storage portion 9 to stir the developer.
An agitating supply paddle 15 for supplying developer to the fur brush 13 in the developing mechanism section 10 through the agitation supply paddle 15 is provided and is pivotally supported on the side wall by a shaft 16. This agitation supply paddle 15 is made of a flexible sheet-like body, and has an opening 15a formed therein to increase the agitation efficiency with an appropriate pinch. Further, the shaft 16 is provided with stirring blades 1 for preventing the toner from forming into blocks.
7 is installed.

Further, a shutter member 18 that opens and closes the developer supply port 5 formed in the partition plate 95 is arranged to be movable up and down along the partition plate 95, and is moved downwardly by a spring 19 so as to close the developer supply port 5. The facing side is energized. An opening operation shaft 20 is vertically provided from both sides of the shutter member 18 and extends downwardly through the bottom wall surface of the developer casing 2 . Then, as shown in FIG. 2, the image forming cartridge 1 is inserted into the printer 31.
It is attached to the upper frame 33 of the
When the opening operation shaft 20 is closed and set in the image forming state, the lower end of the opening operation shaft 20 touches the lower frame 3, as shown in FIG.
2 and is pushed up against the spring 19,
The toner supply port 5 is configured to be open.

Thus, when the image forming cartridge 1 is transported, the shutter member 18 is pressed down by the spring 19 and the developer supply port 5 is closed, so that the developer is sealed inside the developer storage section 9 and is not allowed to flow inside the developing mechanism section 10. Therefore, even if the developer is handled roughly during transportation, there is no risk of the developer leaking out from the gap around the developing roller 11. Further, even when the image forming cartridge 1 is installed and in use, if the upper frame 33 is opened upward as shown in FIG. 2, the toner supply port 5 is closed, so that the opening angle of the upper frame 33 is large. Even if the image forming cartridge 1 is loaded or taken out, even if it receives a shock when opened, or if the image forming cartridge 1 is roughly handled when it is taken out, toner will not be excessively supplied to the developing mechanism section 10. Therefore, it is possible to reliably prevent toner from leaking to the outside or from oversupplying toner onto the developing roller 11.

The lower part of the fur brush 13 is in contact with the bottom wall surface of the developer casing 2, and the toner is charged by forming a layer 80 made of a material that charges the toner to a predetermined polarity at the contact portion of the bottom wall surface with the fur brush 13. I'm trying to eliminate unevenness.

Further, a wire 82 for scraping off the developer is provided on the back of the fur brush 13. This allows fur brush 1
When the residual developer supplied to the developing roller 11 on 3 returns to the back side of the fur brush 13, this residual developer is scraped off from the surface of the fur brush 13 by the wire 82, and the unused developer is removed. taken back inside. 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 caught by the fur brush 13 and supplied to the developing roller 11 without being mixed with unused developer. Therefore, it is possible to prevent the stress of the residual developer that is not supplied to the developing roller 11 on the fur brush 13 from affecting the developing characteristics.

The developer casing 2 and the waste toner casing 3 are connected to the shaft 2.
1, and the photosensitive drum 4 and the developing roller 11 are
and positioning rollers 23.2 on both shafts 6.12.
4 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 30 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 30 extends to the waste toner casing 3 and covers the waste toner casing 3, making it easy to handle the image forming cartridge 1 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 a play is provided between the lid 30 and the waste toner casing 3 to an extent 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 plate 25 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 is in pressure contact therewith. A seal plate 26 is provided that extends to the drum 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.

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 IE 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. through the part of
Even if the developer tries to get on top of the ejected air, the semipermeable membrane 85 prevents it from ejecting to the outside. Such a structure can be applied to the waste toner casing 3 as well, if necessary.

This image forming cartridge 1 is used, for example, by being attached to the printer 31 shown in FIG. 2 as described above. 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 is closed to the lower frame 32, the image forming cartridge 1 has a paper passing path 3 for printing between the transfer charge 36 provided on the lower frame 32 side.
7, and when the upper frame 33 is opened upward as shown in FIG. 2, the paper passing bus 37 is opened, making troubleshooting such as jamming easier.

A laser scanning unit 38 is provided above the portion of the upper frame 330 where the image forming cartridge l is mounted. This laser scanning unit 38 deflects a laser beam 39 from a laser emission source modulated according to an image signal provided by a personal computer, image league, etc., onto the photosensitive drum 4 using an appropriate scanning means such as a polygon mirror. image exposure on the photosensitive drum 4. For this image exposure, the image forming cartridge 1 is provided with an exposure ring 51 on a part of the lid 30 that enables image exposure to the photosensitive drum 4, and inside the image forming cartridge 1, electrostatic charge is generated by the image exposure. A charger 52 that uniformly charges the surface of the photosensitive drum 40 is provided in front of the image exposure position of the photosensitive drum 4 so that a latent image is formed.

As shown in detail in FIGS. 4 and 5, an elastic blade 41 is pressed against the developing roller 11. As shown in FIGS. As the elastic blade 41, a rubber blade such as urethane rubber or silicone rubber, or a metal blade such as phosphor bronze for springs or spring rope is useful. The base of the elastic blade 41 on the side opposite to the pressure contact portion with respect to the developing roller 11 is attached to a metal support member 42 by adhesive or the like, and both ends of this support member 42 are fixed to both side walls of the developer casing 2. .

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 1 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 (
(Fig. 5) will occur.

Therefore, if the elastic blade 41 is uniformly and continuously pressed over the entire length of the developing roller, it will not carry the developer, and the developer non-carrying area Y will have a small diameter.
Floating occurs between the two and causes 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 is divided by the notch 86 into the center side in the longitudinal direction facing the developer carrying area X and the developer non-carrying area Y of the developing roller 11, and the sections 41a and 41b on both sides thereof. Since the respective portions 41a and 41b independently press against the developer carrying area X and the developer non-carrying area Y of the developing roller 11 without being influenced by each other, there is a step Z between the respective areas X and Y. Part 4 of the elastic blade 41
1b can be brought into close contact with a portion of the developer non-carrying area Y, as shown in FIG. Therefore, the elastic blade 41
It is possible to eliminate the inconvenience in which the developer floats from the developing roller 11 in the developer non-carrying area Y and the developer leaks from the developer non-carrying area Y to the photosensitive drum 4 side.

Further, the portion 41b of the elastic blade 41 is attached to the support member 42.
It is held down by presser metals 57 attached to both ends of the holder, which further prevents it from lifting up. Developing roller 1
A sealing material 88 is interposed between 1 and the side wall 87.

Furthermore, in a long continuous portion of the elastic blade 41 in the longitudinal direction, pressure contact with the developing roller 11 tends to be stronger in the central portion of the continuous range than in other portions.
The layer thickness of the developer formed on the developing roller 11 tends to be non-uniform in the axial direction of the developing roller 11, which causes uneven development characteristics. Therefore, in this embodiment, in order to solve this problem,
A groove 81 as shown in FIGS. 1 and 4 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.

As a result, the long portion 41a of the elastic blade 4I
The bending rigidity at the central portion in the longitudinal direction is weakened by the concave groove 81, and the pressing force against the developing roller If is reduced, and the pressing force against the developing roller 11 of the entire long portion 41a of the elastic blade 4 is reduced. become equal.

Further, 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 if 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 12, and uniform development characteristics can be expected over the entire developer carrying head 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 reduced compared to when a molded product such as urethane foam is used. In this case PE
Since T is a strong material, we did not want to damage the developing roller 11 or cause chatter, so in order to avoid contact with the tip of the developing roller 11, we installed the developing roller 11 at the so-called abdomen.
It is preferable to press the material into contact with the material.

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 IJ 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 a small diameter. The small-diameter photosensitive drum 4 to be scratched 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 (Figs. 1 and 3). As a result, the charging charger 52 is initially a corotron type charger without a grid or exhibiting charging characteristics similar to that 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 bus 37.
The developed toner image formed on the photosensitive drum 4 is transferred to the transfer paper 91 from the back side of the transfer paper 91 being conveyed.
Transfer it on top.

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 path 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 pink-up roller 93 in a stopped state, and then feeds the transfer paper 91 at a predetermined timing and then The leading edge is aligned with the toner image formed on the drum 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.

Immediately after the transfer charger 36 of the lower frame 32, an eraser lamp 63 is provided, which irradiates the surface of the photosensitive drum 4 after transfer with an erase light through the transfer paper 91 that is being passed, and erases the surface of the photosensitive drum 4. 4.Remove residual charges on the surface. A light receiving end 65 of an optical fiber 65 is located near the eraser lamp 63.
a 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 density sensor 64 can detect the density of the toner image by sharing the eraser lamp 63 for illuminating the image to be inspected. By sharing the eraser lamp 63 and using the optical fiber 65, a special space is created around the transfer section. It is possible to detect the density of a toner image without the need for a , and cost is also 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 punched out from 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 1 is not in use, that is, when the drive system has never been operated and no developer is consumed, this abutment position is set a predetermined amount downstream from the recess 76 of the cam surface 77 in the driving direction. It's 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 a small amount of rotation compared to the amount of drive 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 image forming 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 1 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.

Although the above embodiment shows an example in which the developing device is integrated into the image forming cartridge 1, it goes without saying that the present invention can also be applied to a developing device that is detachably attached to the main body of the apparatus. Furthermore, in the above embodiment, the developer storage section 9
Although the example in which the and developing mechanism section 10 are integrated is shown, the developer storage section 9 is connected to the developing device or the image forming cartridge l.
It can also be constructed so that it can be attached and detached.

Effects of the Invention According to the present invention, when the developing device is transported, when the developing device is taken out from the device main body, and furthermore, when the upper frame is opened in the case of a device main body configured to open the upper frame diagonally upward, When the developing device is not installed in the main body of the device that is set to the state where image formation is possible, the shutter member is automatically closed by the biasing means and the developer in the developer container is released into the developing device. Since the agent is prevented from entering the developing mechanism through the supply port, even if it is handled roughly during transportation or installation/removal, or when the upper frame is opened,
Even without any operation, it is possible to reliably prevent the developer from leaking out from the gap around the developing roller or from excessively supplying the developer to the developing roller.

[Brief explanation of drawings]

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 front view showing the schematic configuration of the printer with the image forming cartridge installed, and Fig. 3 is a charging FIG. 4 is a perspective view showing the developing roller section, FIG. 5 is an enlarged front view of a portion of the developing roller section, and FIG. 6 is a partially enlarged sectional view of the charger, and FIG. 6 shows the unused detection mechanism section of the image forming cartridge. FIG. 3 is a cross-sectional view of a part of the waste toner casing. 2--・------------------m-Developer casing 5---------1---1--1--Developer Agent supply port 9−・−−−−−・−・−−−−
m-・-Developer storage section 10----------111-
--=--------Developing mechanism section 18--------
−−−−−−−Shank member 19− ・−−−1−−
−−−−−−・−1−−Spring 20−・−1−−−−・
−1−−−−・−・−Opening operation axis. Agent Patent Attorney Masaru Ishihara

Claims (1)

[Claims] (1) In a developing device that is removably attachable to the main body of an image forming apparatus, a developer storage section and a developing mechanism section that forms a thin layer of developer on the outer circumferential surface of a developing roller are separately provided;
A shutter member for opening and closing the developer supply port opened between the developer accommodating section and the developing mechanism section is provided, and a means for urging the shutter member to close is provided, and the shutter member is set in a state where image formation is possible. 1. A developing device comprising means for opening a shutter member against a biasing means when the developing device is attached to a main body of the developing device.