JPH03260684A - Blade press-contact structure for roller - Google Patents

Abstract

PURPOSE:To equalize the press-contact force of the tip part of an elastic blade to a roller with simple constitution by forming a recessed groove directed in a required direction at the required position of the elastic blade. CONSTITUTION:The elastic blade 41 which is disposed in parallel with a developing roller 11 is allowed to press-contact to the outer peripheral surface of the roller such as the developing roller 11. The recessed groove 81 directed in a longitudinal direction is formed at the position of the central part in the width direction of the blade 41, and stress generated in the blade 41 which is allowed to press-contact to the surface of the roller and folded in the width direction is concentrated in the groove 81, thereby equalizing the press-contact force of the tip part of the blade 41 to the roller 11 without complicating the constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a blade pressure contact structure of a roller used in an image forming apparatus such as a copying machine, facsimile machine, or printer that forms an image using a calculator photography method. This invention relates to a blade pressure contact structure of a roller that presses an elastic blade arranged parallel to the roller blade.

Prior art The blade pressure contact structure of this type of roller is disclosed in, for example, Japanese Patent Application Laid-open No. 63
As disclosed in Japanese Patent Publication No. 235970, etc., an elastic blade that is brought into pressure contact with the outer circumferential surface of a developing roller of an image forming apparatus presses and thins a single-component developer carried by the developing roller, or As disclosed in Japanese Patent No. 57-154255, there is an elastic blade that is brought into pressure contact with the surface of the photoreceptor after transfer to scrape off residual developer on the photoreceptor.

Conventionally, each of these blades has a simple plate shape that is uniformly continuous in the length direction and has a uniform thickness, and the tip portion is pressed against the surface of the roller while the base portion is fixed.

Problem to be Solved by the Invention However, in such a conventional structure, a phenomenon occurs in which the pressing force of the elastic blade against the roller surface is strong at the center in the longitudinal direction and weak at both ends.

For this reason, when the developer on the developing roller is made into a thin layer, the thickness of the thinned developer layer is thinner at the center in the longitudinal direction of the developing roller and thicker at both ends, so that the developing agent on the photoreceptor is The amount of agent supplied becomes uneven, causing uneven development. In addition, when cleaning the photoconductor by scraping off residual developer, even if the longitudinal center of the photoconductor can be sufficiently cleaned, cleaning pressure is insufficient at both ends, resulting in poor cleaning. This causes stains on images formed by the image forming apparatus.

Therefore, the present invention aims to achieve the following by simple improvement of the elastic blade.
It is an object of the present invention to provide a roller blade pressure contact structure that can solve the above-mentioned problems.

Means for Solving the Problems In order to achieve the above-mentioned problems, the invention of the present application cylinder 1 provides a roller blade pressure contact structure in which an elastic blade arranged parallel to the outer peripheral surface of the roller is pressed into contact with the outer peripheral surface of the roller. The elastic blade is characterized in that a concave groove facing in the longitudinal direction of the elastic blade is formed at a central position in the width direction of the elastic blade.

The invention of the cylinder 2 of the present application is further characterized in that, in the first invention, the groove is formed leaving both ends of the blade in the longitudinal direction.

Function In the above structure of the invention of the present cylinder 1, the elastic blade has a concave groove facing in the longitudinal direction of the elastic blade formed at the center position in the width direction, so that the elastic blade is pressed against the surface of the roller and bent in the width direction. The stress caused by this is concentrated on the groove portion,
The pressing force of the tip of the elastic blade against the roller can be equalized.

Furthermore, in the above structure of the invention of the present invention cylinder 2, the concave groove is formed leaving both ends of the elastic blade in the longitudinal direction, and weakens the bending rigidity of the elastic blade, especially in the center part in the longitudinal direction. It is possible to actively reduce the pressing force on the roller in a predetermined range, and more reliably equalize the pressing force on the roller over the entire length of the elastic blade.

EXAMPLE A printer having a roller blade pressure contact structure as an example of the present invention shown in FIGS. 1 to 6 will be described below.

The first part shows an image forming cartridge 1 equipped with a blade pressure contact structure according to the present invention. This cartridge 1 includes a developer casing 2 and a waste toner casing 3 as shown in the figure.
It is formed by connecting. 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.
As a result, residual toner scraped off from the top of the photosensitive drum 4 is accommodated 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 selenium oxide, 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 development roller 11 from being captured by the sponge roller 13 and supplied to the development roller 11 without being mixed with the unused development side. For this reason, the sponge roller 13
It is possible to prevent the stress of the residual developer 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 by the urging force of the springs 22 that act between them.
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.

An LFF 130 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 prevent 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.

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
A paper passing bus 37 for printing is formed between the upper frame 33 and the upper frame 33 as shown in Fig. 6, and the paper passing bus 37 is opened to facilitate troubleshooting such as jams. .

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 has an M
An exposure slit 51 that enables image exposure to the photosensitive drum 4 is provided in a part of the photosensitive drum 2O, and an image on the photosensitive drum 4 is formed in the image forming cartridge 1 so that an electrostatic latent image is formed by image exposure. A charger 52 that uniformly charges the surface of the photosensitive drum 4 is provided in front of the exposure position.

On the other hand, a seal plate 25 is provided at the bottom edge 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 therewith. A seal plate 26 is provided that extends to the photosensitive drum 4 and presses against it. As a result, the development area 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. can do.

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 M2O, and the opening 84 is closed with a semipermeable membrane 85. The semipermeable membrane 85 is made of a material 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 with low resistance prevents the air from blowing out. Even if the developer tries to get on top of the ejected air through the portion 85, 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.

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.

An elastic blade 41 is pressed against the developing roller 11 . 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 upper end of the elastic blade 41 is attached by adhesive or the like to a metal support member 42 that is stretched between the side walls of the developer casing 2, and the lower end is attached to the developing roller 1.
It is pressed against the surface of 1.

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 (FIGS. 2 and 3).

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, the diameter of the developer carrying area X of the developing roller 11 is somewhat different from that 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. 3) will occur.

Therefore, if the elastic blade 41 is uniformly and continuously pressed over the entire length of the developing roller 11, it will not carry the developer, and moreover, 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, 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 against the developing roller 11 of the entire long portion 41a of the elastic blade 41 is reduced. become even. In this sense, the concave groove 81
It is also effective to simply form the elastic blade 41 over a long area. 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.

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

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.

As another example, an insulating elastic roller may be used instead of the elastic blade 41, in which case the developing roller 11
You can set the relative speed in any way you like. This allows the charging characteristics to be adjusted in various ways,
Depending on whether the elastic roller is rotated in a subordinate direction to the developing roller 11 or in the opposite direction, the surface layer of the developer on the developing roller 11 is actively subjected to development;
It becomes possible to select whether to make it difficult to be subjected to development. Such selection is based on the developer, developer supply mechanism, and photosensitive drum 4.
This is useful when dealing with various types of image forming conditions, such as types, etc., or when responding to special requests.

In addition, a speed change mechanism is provided in the drive system of the developing roller 11 to increase the rotational speed of the developing roller 11 when forming an image with poor reproducibility such as a line drawing or a dot image. Increasing the supply amount improves reproducibility even for line drawings and dot drawings.

In this embodiment, the configuration of the charger 52 is devised in response to the fact that the photosensitive tram 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 charges 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 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 L 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 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 bus 37, as shown in FIG. The timing roller pair 61 partially receives the transfer paper 91 pinked up and fed from the paper feed cassette 92 by the pickup roller 93 in a stopped state, and then feeds the transfer paper 91 at a predetermined timing. The leading edge of the photosensitive drum 4 is aligned with the toner image formed on the photosensitive drum 4 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 transfer is cleaned by a cleaning plate 1.
” 7 to remove residual toner.

An eraser lamp 63 is provided immediately after the transfer charger 36 of the lower frame 32, and it irradiates the surface of the photosensitive drum 4 after transfer with erase light through the transfer paper 91 that is being passed, thereby erasing the surface of the photosensitive drum 4. removes residual charge. 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 halo 5 is configured to guide reflected light when a toner image formed on the photosensitive drum 4 is illuminated by an 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.

Further, 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 40 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 plate 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 cost can be reduced by punching out a PET sheet. Further, the concave groove is effective when applied to other elastic blades whose tips are pressed against roller members.

As shown in FIG. 5, the waste toner casing 3 is provided with an unused detection mechanism 71 that is linked to the drive system. This unused detection mechanism 71 includes a gear 73 provided on one shaft of the drive system, such as a paddle 80 and a rotating wheel 72 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 bin 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. The contact position 20 is located downstream from the recess 76 of the cam surface 77 in the driving direction when the image forming cartridge 1 is unused, that is, when the drive system is never operated and no developer is consumed. This is a position where quantification is possible.

When the image forming cartridge I 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 bin 78 by a small amount of rotation compared to the amount of drive for use. At this opposing position, the detection bottle 7B is fitted into the recess 76 by the bias of the spring 79.

The detection bin 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 bin 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 bin 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 an unused image forming cartridge l is installed.

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. In this case, it is preferable to employ a speed reduction mechanism. Furthermore, it can be said that the time point when the image forming cartridge l has been used for printing the limit number of sheets can be detected to warn against further use.

Effects of the Invention According to the invention of cylinder 1, the elastic blade has a concave groove facing in the longitudinal direction of the elastic blade formed at the center position in the width direction, and is pressed against the surface of the roller and bent in the width direction. The stress caused by this is concentrated in the groove, and the pressure force of the tip of the elastic blade against the roller is equalized, so operations such as thinning of the developer layer and cleaning, which are performed by pressing the elastic blade against the roller, are performed. This can be achieved uniformly over the entire longitudinal direction of the roller, and since the only improvement is the shape of the elastic blade, the structure does not become complicated and the cost does not increase.

According to the invention of the present cylinder 2, the groove is formed leaving both ends of the elastic blade in the longitudinal direction, and weakens the bending rigidity of the elastic blade, especially in the central part of the longitudinal direction, so that the groove is formed in a predetermined range of the central part of the elastic blade in the longitudinal direction. This has the advantage that the pressing force on the roller can be actively reduced, and the pressing force on the roller can be more reliably equalized over the entire length of the elastic blade.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view of an image forming cartridge having a roller blade pressure contact structure as an embodiment of the present invention, Fig. 2 is a perspective view showing a developing roller section, and Fig. 3 is a part of the developing roller section. 4 is an enlarged sectional view of a portion of the charging charge 1, FIG. 5 is a sectional view of a portion of the waste toner casing showing the unused detection mechanism of the image forming cartridge, and FIG.
1 is a sectional view showing a schematic configuration of a printer in which the image forming cartridge shown in the figure is used. 1 Photosensitive drum cleaning blade Developing roller 1 1 Elastic blade concave groove

Claims (2)

[Claims] (1) In a roller blade pressure contact structure in which an elastic blade arranged parallel to the outer peripheral surface of the roller is pressed into contact with the outer peripheral surface of the roller, a concave groove facing in the longitudinal direction of the elastic blade is formed at a central position in the width direction of the elastic blade. A roller blade pressure welding structure featuring: (2) The roller blade pressure contact structure according to claim 1, wherein the concave groove is formed leaving both ends of the blade in the longitudinal direction intact.