JP5836702B2 - Development device - Google Patents

Description

The present invention relates to a developing apparatus having a developer regulating member for use in visualizing and developing the electrostatic latent image formed on an image bearing member.

  The prior art will be described with reference to FIGS. FIG. 5 is a schematic sectional view showing an example of an image forming apparatus using a process cartridge, and FIG. 6 is an example of an image forming apparatus using the process cartridge.

  In this example, the image forming apparatus 100 includes a process cartridge 200, and the process cartridge 200 is an image carrier (hereinafter referred to as a “photosensitive drum”) 1 that is a charged body that rotates in the direction of an arrow A in the figure. And a charging device 2 for uniformly charging the photosensitive drum 1. Further, the process cartridge 200 develops an electrostatic latent image formed by exposing an image on the uniformly charged photosensitive drum 1 by the exposure device 3 with a developer (hereinafter referred to as “toner”) T. A developing device 4 for developing a visible image is provided. The process cartridge 200 is further integrated with a cleaning device 7 that removes toner remaining on the photosensitive drum 1 after transfer of a visible image.

  In general, the developing device 4 supplies the toner T accommodated in the developing container 4a to the developer carrying member (hereinafter referred to as “developing sleeve”) 8 by the stirring member 12 disposed in the developing container 4a, and develops the toner T. As the sleeve 8 rotates, it is conveyed in the direction of the developer regulating member 11. By passing the toner T between the developing sleeve 8 and the developer regulating member 11, a uniform toner layer imparted with a frictional charge can be formed on the developing sleeve 8 and then conveyed toward the photosensitive drum 1. . A constant minute gap is provided between the developing sleeve 8 and the photosensitive drum 1, and an electrostatic bias image formed on the photosensitive drum 1 is applied to the friction of the toner T by applying an appropriate bias therebetween. It is developed and visualized by electrostatic adsorption with electric charges.

  Further, in order to meet the recent demand for higher image quality and energy saving, it is necessary to use a toner having a smaller particle size and a lower melting point. There has been proposed a developer regulating member in which a polyamide-containing rubber layer is provided on a thin plate having spring characteristics so that the toner is not fused to the developer regulating member 11 even when such toner is used (see Patent Document 1). ).

  By providing a polyamide-containing rubber layer on a thin plate having spring characteristics in this way, it is possible to prevent the occurrence of image unevenness and image streaks due to toner coating unevenness due to toner fusion, and good toner on the developing sleeve. A layer can be formed stably.

JP-A-9-319213

  However, the following problems occur in the conventional example.

  In the process cartridge 200, the photosensitive drum 1, the charging device 2, and the developing device 4 are converted into cartridges, so that the user can replace the process cartridge that has reached the end of its life with a new one. This realizes a configuration that eliminates the need for maintenance by specialized service personnel. Until now, process cartridges that have reached the end of their life have been disposed of. However, due to the recent increase in protection of the global environment, the components constituting the developing device 4 and the charging device 2 of the process cartridge that have reached the end of their life have begun to be reused for the purpose of saving resources and reducing dust.

  One of the components constituting the developing device 4 is the developer regulating member 11 as described above. The developer regulating member 11 has a structure in which a covering member (polyamide-containing rubber layer) is provided on a thin plate. Generally, as shown in FIG. 4A, a covering member 112 having the same shape as the thin plate 111 is provided on the thin plate 111. Is laminated (arrow B). After that, the developer regulating member 11 shown in FIG. 4B is obtained by fixing it to the support metal plate 110 (arrow A). The developer regulating member 11 is fixed to the developing device 4 through the fastening hole 113, and a uniform toner layer can be formed on the developing sleeve 8 by coming into contact with the rotatable developing sleeve 8 fixed to the developing device 4. .

  As the process cartridge 200 repeats the image forming operation, the covering member 112 has a wear action such as scraping due to the rubbing action in the rotating operation of the developing sleeve 8, and reaches the end of its life. In the developer regulating member 11 in which the covering member 112 is laminated on the thin plate 111, even when the process cartridge 200 reaches the end of its life, the wear portion due to durability is only the covering member 112, and the thin plate 111 is in a state without wear. is there. Therefore, although the thin plate 111 can be sufficiently reused if the covering member 112 is peeled off, it is difficult to provide a handle portion necessary for peeling the covering member 112 after the end of its life, so that the recyclability is lowered. Further, there is a method of dissolving only the covering member 112 using a solvent or the like, but it is necessary to appropriately treat the generated waste liquid.

  For the reasons described above, in the developer regulating member 11 in which the covering member 112 is laminated on the thin plate 111, the thin plate 111 and the support metal plate 110 can be reused by simply peeling the covering member 112 from the thin plate 111. Was desired.

An object of the present invention is to provide a developing device having a developer regulating member having a covering member on a sheet that may be in view of the above circumstances, peeled off only briefly cover member from the sheet.

The above objects are achieved by the present image device Ru engaged with the present invention. In summary, according the onset bright, a developer carrying member for bearing and conveying the developer,
A developer regulating member that regulates the amount of developer applied on the surface of the developer carrying member ;
In a developing device having
The developer regulating member is
With a thin plate,
A support metal plate for attaching the thin plate;
A covering member for applying a charge to the developer, which is attached to a contact portion of the thin plate with the developer carrying member by laminating;
With
The covering member has a laminate unprocessed portion that is not laminated with the thin plate in a part other than the contact portion with the developer carrier ,
A developing device is provided.

  According to the present invention, in the developer regulating member in which the coating member is laminated on the thin plate, only the coating member can be easily peeled off from the thin plate, and the recyclability of the developer regulating member can be improved.

It is a figure explaining the whole structure of the developer control member of Example 1 which concerns on this invention, and demonstrates the procedure which peels a coating | coated member from a thin plate. FIG. 5 is a diagram illustrating a production process of a developer regulating member of Example 1. It is a figure explaining the whole structure of the developer control member of Example 2 which concerns on this invention, and demonstrates the procedure which peels a coating | coated member from a thin plate. It is a figure explaining the preparation process of the conventional developer control member. It is a schematic block diagram of the conventional process cartridge which can apply the image development apparatus of this invention. 1 is a schematic configuration diagram of a conventional image forming apparatus to which a developing device of the present invention can be applied.

Hereinafter, the developing device including the developer regulating member according to the present invention will be described in more detail with reference to the drawings.

Example 1
FIG. 6 is a schematic configuration diagram showing the conventional image forming apparatus 100 described above. The developing device of the present invention can be suitably used for such an image forming apparatus.

  As shown in FIG. 6, an image forming apparatus 100 to which a developing device 4 according to an embodiment of the present invention is applied includes a drum-type electrophotographic photosensitive member, that is, a photosensitive drum 1 as an image carrier. . In the photosensitive drum 1, the surface of the photosensitive drum 1 is charged to a predetermined potential, in this example, −700 V, by applying a DC voltage to the charging device 2 in contact with the surface of the photosensitive drum 1 with a power source (not shown). The charged surface of the photosensitive drum 1 is irradiated with light by image exposure by an exposure device 3 that receives an image signal and lights up, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. The electrostatic latent image on the photosensitive drum 1 is developed by the developing device 4 of this embodiment.

  On the other hand, a transfer material P is supplied from a paper cassette (not shown) by a paper feed roller (not shown), and the transfer material P is synchronized with the toner image on the photosensitive drum 1 by a registration roller (not shown) to the transfer device 5. Sent. The toner image on the photosensitive drum 1 is transferred onto the transfer material P by the action of the transfer device 5. The transfer material P that has received the transfer of the toner image is conveyed to the fixing device 6, where the toner image is fixed by heat and pressure in the fixing device 6, and is finally discharged out of the image forming apparatus main body.

  Incidentally, the toner T which is not transferred to the transfer material P and remains on the photosensitive drum 1 in the transfer step is removed by the cleaning device 7 having a rubber blade, and the surface of the photosensitive drum 1 is charged again by the charging device 2 and the above-described step. repeat.

  As shown in FIG. 5, the developing device 4 of the present embodiment includes a developing container 4a containing magnetic toner T, which is an insulating one-component magnetic developer, and can be rotated as a developer carrier in the container. A developing sleeve 8 is installed. On the developing sleeve 8, the toner T is applied in a thin layer by the developer regulating member 11, and is carried and conveyed to the developing unit facing the photosensitive drum 1. There is a minute gap between the developing sleeve 8 and the photosensitive drum 1. In this embodiment, the gap value is set to 300 μm. A non-rotating developing magnet 9 having magnetic poles S1, N1, S2, and N2 is disposed in the developing sleeve 8, and serves to supply and carry the toner T to the developing sleeve 8. A power source 10 is connected to the developing sleeve 8, and the power source 10 applies a voltage to the developing sleeve 8 to visualize the electrostatic latent image on the surface of the photosensitive drum 1 by reversal development with the toner T, and the photosensitive drum of the developing unit. A predetermined electric field is formed between 1 and the developing sleeve 8. In this embodiment, a DC voltage of −350 V, an AC voltage of 1500 Vpp, a frequency of 2000 Hz, and a rectangular waveform voltage are applied to the developing sleeve 8.

  In the developing container, a rotating sheet-like stirring member 12 for feeding the toner T to the developing sleeve 8 is provided in the vicinity of the developing sleeve 8. The stirring member 12 is rotationally driven in the direction of arrow R by a driving means (not shown). The agitating member 12 is provided with a sheet of polyethylene terephthalate having a thickness of 50 μm on an attachment shaft rotatably supported by a rotation shaft on a frame constituting the developing container 4a. As the toner T, a negative toner having a volume average particle diameter of about 8.0 μm was used.

  The developer regulating member 11 described above is fixed at a position above the developing sleeve of the developing container 4a, and contacts the developing sleeve 8 with a predetermined pressure, thereby regulating the toner T carried on the developing sleeve 8 and generating a frictional charge. A thin coat of toner is formed.

  As shown in FIG. 2A, the developer regulating member 11 is attached to a contact portion between a support sheet metal 110 processed from stainless steel, a thin plate 111 attached to the support sheet metal 110, and the developing sleeve 8 of the thin plate 111. And a covering member 112 attached thereto. In this embodiment, a phosphor bronze plate having a thickness of 80 μm and a longitudinal length of 230 mm is used for the thin plate 111, but stainless steel having the same shape may be used. Further, the covering member 112 is for imparting electric charge to the developer at the contact portion with the developing sleeve 8. In this embodiment, the covering member 112 is made of polyamide elastomer with a thickness of 30 μm and a longitudinal length of 240 mm. I used something. The short length of both the thin plate 111 and the covering member 112 is 15 mm.

  As a method for producing the developer regulating member 11 of this embodiment, as shown by an arrow B in FIG. 2A, a coating member 112 is laminated on a thin plate 111, and then the support sheet metal 110 is formed as shown by an arrow A. A thin plate 111 having a covering member is attached and fixed. If the covering member 112 is not uniformly bonded to the thin plate 111 on the surface in contact with the developing sleeve 8, toner coating unevenness on the developing sleeve 8 due to floating or dripping of the covering member 112 occurs. For this reason, a uniform laminating process is performed on the contact surface with the developing sleeve 8 so that there is no unlaminated portion.

  As a method of fixing the support member 110 and the thin plate 111, the thin plate 111 and the support metal plate 110, which are laminated with the covering member 112 over seven longitudinal points, can be fastened and fixed with a screw (not shown).

  As shown in FIG. 2B, the developer regulating member 11 produced in this way has a shape in which the length of the covering member 112 is longer than the thin plate 111 by the length (E). Therefore, the portion 112b of the non-laminated covering member that protrudes from the thin plate 111 is arranged in the direction of the arrow C, that is, in a portion other than the contact portion with the developing sleeve 8, in this embodiment, the developer regulating member 11 At one side, the developer regulating member 11 is bent to the back side opposite to the coating member side. In this embodiment, the unprocessed portion of the laminate is on the surface (back surface) where the developer regulating member 11 does not contact the developing sleeve 8 as shown in FIG. The covering member portion 112b bent in the above manner was fixed using a tape material 114. Since the surface of the developer regulating member 11 that does not come into contact with the developing sleeve 8 basically has no influence on the toner layer coated on the developing sleeve 8, the tape material 114 is fixed on the support metal plate 110 or the thin plate 111. Good. The developer regulating member 11 thus produced is attached to the developing device 4 and an image forming operation is executed.

  When the developing device 4 to which the developer regulating member 11 manufactured as described above is attached reaches the end of its life, the developing device 4 is disassembled and the developer regulating member 11 is taken out. In the developer regulating member 11 taken out, the tape material 114 affixed to the back surface is peeled off, and the state shown in FIG. Here, in order to prevent the thin plate 111 from being bent when the covering member 112 is peeled off from the thin plate 111, the entire length of the back surface of the developer regulating member 11 is adsorbed by air or static electricity, and is covered by the hand 13 from the thin plate 111. The member portion 112b is grasped and pulled in the direction of the arrow in the drawing, and the covering member 112 is peeled off from the thin plate 111. By peeling the covering member 112 from the thin plate 111, as shown in FIG. 1B, the surface of the thin plate 111 without wear is exposed.

  The developer regulating member 11 from which the covering member 112 has been peeled off removes the screw that fastens and fixes the thin plate 111 from the support metal plate 110, and again places the covering member 112 on the thin plate 111 and laminates it by heat or pressure. The developer restricting member 11 is reused.

  Further, for example, the thin plate 111 may be reused as it is without laminating the covering member 112 in a low-life developing device having a small toner capacity and less concern about toner fusion to the developer regulating member 11. In either case, at least the thin plate 111 and the support metal plate 110 can be used twice or more, and the image quality can be maintained until the life of the developing device.

  As described above, in order to reuse the developer regulating member 11 in which the covering member 112 is laminated on the thin plate 111, the unprocessed portion of the covering member 112 other than the contact surface between the thin plate 111 and the developing sleeve 8 is used. The configuration in which 112b is provided is important.

Example 2
Next, a second embodiment of the present invention will be described with reference to FIG. The configurations of the image forming apparatus and the developing apparatus used in this embodiment are the same as those in the first embodiment. Therefore, the description of the first embodiment is used for the description of the image forming apparatus and the developing device, and the developer regulating member 11 which is a characteristic part of the present embodiment will be described below.

  The second embodiment has a configuration in which deformation due to bending of the thin plate 111 when the covering member 112 laminated on the thin plate 111 is peeled is suppressed.

  As shown in FIG. 3A, the developer restricting member 11 of the second embodiment is also composed of a support metal plate 110 processed with stainless steel, a thin plate 111, and a covering member 112, as in the first embodiment. . A phosphor bronze plate having a thickness of 80 μm and a longitudinal length of 230 mm was used for the thin plate 111, and a polyamide elastomer having a thickness of 30 μm and a longitudinal length of 230 mm, which was the same as that of the thin plate 111, was used for the covering member 112. In the present embodiment, the covering member 112 has a cut shape 112c at the 115 mm portion from both sides above the central portion of the longitudinal length. The cut shape 112c may have any shape as long as it does not contact the developing sleeve 8. If the covering member 112 is not uniformly bonded to the thin plate 111 on the surface in contact with the developing sleeve 8, toner coating unevenness on the developing sleeve 8 due to floating or dripping of the covering member 112 occurs. For this reason, a uniform laminating process is performed on the contact surface with the developing sleeve 8 so that there is no unlaminated portion. The cut shape portion 112c, which is a laminate processing portion, also has a shape portion 112b protruding toward the support metal plate 110, and the protrusion 112b and the support metal plate 110 are not laminated. The protrusion 112b may have any shape as long as it can be grasped.

  Further, this embodiment does not require processing such as bending of the end of the covering member 112 as described in the first embodiment or adhesion on the back side of the developer regulating member with a tape agent.

  When the developing device 4 to which the developer regulating member 11 manufactured as described above is attached reaches the end of its life, the developing device 4 is disassembled and the developer regulating member 11 is taken out. As shown by the arrow in FIG. 3B, the covering member 112 starts to be peeled off from the portion where the thin plate 111 and the support metal plate 110 are fixed after gripping the protruding portion 112 b. Therefore, compared with the case where the thin plate 111 is peeled off from the free end such as the thin plate end portion, there is no concern about the bending of the thin plate 111 that occurs during the peeling, and it is not necessary to peel off the developer regulating member 11 while air adsorption or electrostatic adsorption. . The covering member 112 that has started to peel off is peeled toward the free ends at both ends of the thin plate 111 as shown by the arrows in FIG. By providing the covering member 112 with the cut shape 112c as shown in FIG. 3A, it becomes easy to peel in the intended peeling direction as shown by the arrow in the figure. In this way, the covering member 111 can be more easily peeled off without concern about bending of the thin plate 111 by peeling from the fixed end to which the thin plate 111 is fixed toward the free end of the end.

  The developer regulating member 11 from which the covering member 112 has been peeled off removes the screw that fastens and fixes the thin plate 111 from the support metal plate 110, and again places the covering member 112 on the thin plate 111 and laminates it by heat or pressure. Re-use as a developer regulating member. Further, for example, the thin plate 111 may be reused as it is without laminating the covering member 112 in a low-life developing device having a small toner capacity and less concern about toner fusion to the developer regulating member 11. In either case, at least the thin plate 111 and the support metal plate 110 can be used twice or more, and the image quality can be maintained until the life of the developing device.

  As described above, the structure in which the unprocessed portion 112b of the covering member 112 is provided in the portion where the thin plate 111 and the support metal plate 110 are fixed, and is peeled from the portion toward the free end portion of the thin plate 111 is important.

1 Photosensitive drum (image carrier)
8 Development sleeve (developer carrier)
DESCRIPTION OF SYMBOLS 11 Developer control member 110 Support sheet metal 111 Thin plate 112 Cover member 112a Lamination process part 112b Laminate unprocessed part 112c Cut shape 114 Tape material

Claims (5)

A developer carrier for carrying and conveying the developer;
A developer regulating member that regulates the amount of developer applied on the surface of the developer carrying member;
In a developing device having
The developer regulating member is
With a thin plate,
A support metal plate for attaching the thin plate;
A covering member for applying a charge to the developer, which is attached to a contact portion of the thin plate with the developer carrying member by laminating;
With
The covering member has a laminate unprocessed portion that is not laminated with the thin plate in a part other than the contact portion with the developer carrier,
A developing device. The developing device according to claim 1, wherein the covering member is a polyamide elastomer . The developing device according to claim 1, wherein the unprocessed portion of the covering member is provided on one side of the developer regulating member . The developing device according to claim 1, wherein the unprocessed portion of the covering member is provided above a central portion of the developer regulating member . The developing device according to claim 4, wherein the laminating portion of the covering member has a cut shape at a central portion of the developer regulating member .

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