JPH07219399A - Image forming device - Google Patents

Abstract

PURPOSE:To miniaturize a whole device, to satisfactorily and uniformly electrify an image carrier even at the time of a high speed rotation, and to form an excellent image by providing a cleaning member with an electrifying layer for electrifying the surface of the image carrier. CONSTITUTION:The cleaning member 1 is formed in a state of the plate integrally laminated with the electrification layer 1a and the discharging layer 1b respectively having the triangular-shaped cross sectional plane, and held in slidable contact with the surface of the image carrier 3 at the forward end part. By the electrification layer 1a to which a bias is applied, the surface of the image carrier 3 is uniformly electrified and the electrostatic latent image on the surface of the image carrier 3 is developed to the visual image with the toner from the developing means 7. While, after transferring the toner image 4 to the transfer paper 9, the remaining toner 4a on the surface of the image carrier 3 is scraped off by the discharging layer 1b composing the cleaning member 1 and being grounded, then transported to the outside of the cleaning device 2. Thus, the device can be miniaturized, by respectively imparting the electrification and the discharging function to the respective layer of the cleaning member composed of the laminated layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copying machine, a facsimile,
The present invention relates to improvement of an electrophotographic image forming apparatus such as a printer or a printing machine, a scanner, or a composite machine having these functions together. More specifically, the residual toner remaining on the surface of an image carrier carrying a toner image. The present invention relates to an image forming apparatus that has an improved cleaning member that scrapes off an image.

[0002]

2. Description of the Related Art Conventional electrophotographic image forming apparatuses such as copying machines, facsimiles, printers, printing machines, scanners,
Alternatively, an image forming unit such as a multi-function peripheral having these functions also electrostatically irradiates image information such as reflected light from a document onto an image carrier (photoreceptor) that has been uniformly charged in advance. An image is formed by forming a latent image and transferring and fixing a toner image obtained by applying toner to the electrostatic latent image from a developing device on recording paper. The toner and the like remaining on the image carrier after the toner transfer is removed by a cleaning device to prepare for the next image forming step.

By the way, conventionally, a contact static eliminator for charging and removing static electricity by bringing a blade-shaped plate-like body into contact with the surface of an image carrier has achieved a space saving due to the miniaturization of the main body of the apparatus, and the environment. It is used to reduce the amount of ozone generated as a countermeasure. For example, an electrophotographic printing device in which a cleaning unit and a contact charge eliminator are integrated is known (see JP-A-3-13973). Further, a cleaning blade having a multi-stage edge provided at the end of the image bearing member which comes into contact with the surface of the photoreceptor is also known (Japanese Utility Model Publication No. 50-142439, Japanese Utility Model Publication No. 63-1).
See Japanese Patent No. 94369). Further, there is also known an electrophotographic copying machine having a cleaning blade having a multi-layer structure in order to prevent stress from concentrating on one member (see Japanese Patent Application Laid-Open No. 63-159892).

However, by any of the above-mentioned conventional techniques, it is possible to obtain a member made of a material which simultaneously fulfills all the functions of the cleaning function as the cleaning member, the charging function as the charging member, and the static elimination function as the static elimination member. Instead, static elimination and electrification were made up of separate blade-shaped plate-shaped members. Therefore, the entire apparatus tends to be large, and especially when the image carrier rotates at high speed, the contact time between the image carrier and the plate-shaped body is shortened, and sufficient charging or uniform charging is not performed, and high-quality image formation cannot be performed. There was a problem.

[0005]

In the conventional image forming apparatus, the blade for charging or discharging is provided separately from the blade as the cleaning member, so that the entire apparatus becomes large, and in particular, When the image carrier is rotated at a high speed, the contact time becomes short, and sufficient charging and uniform charging are not performed, and high quality image formation cannot be performed.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to solve such a problem. That is, it is an object of the present invention to provide an image forming apparatus in which the size of the entire apparatus is reduced, and sufficient charging or uniform charging is performed even when the image carrier rotates at high speed to perform high quality image formation.

[0007]

In order to achieve the above object, the present invention provides a plate-shaped cleaning member which is in sliding contact with the surface of an image carrier to scrape off residual toner remaining on the surface of the image carrier. In the image forming apparatus including the above, the cleaning member has at least a charging layer having a function of charging the surface of the image carrier, and the plate-shaped cleaning member is downstream in the rotation direction of the image carrier. The charging layer is provided on the side surface (the surface facing the image carrier), and the upstream side surface in the rotation direction of the image carrier (the surface not facing the image carrier).
To have a charge eliminating layer having a function of eliminating charge on the surface of the image bearing member, the cleaning member has a function of electrically insulating the charge layer and the charge eliminating layer between the charge layer and the charge eliminating layer. The cleaning member has an insulating layer, the cleaning member has at least the charging layer on the downstream side in the rotation direction of the image carrier, and the cleaning member has a multi-stage structure in which residual toner remaining on the surface of the image carrier is multistaged. The present invention is characterized in that it has a multi-stage edge portion that is scraped off by an edge, and that at least one charging blade is arranged at a predetermined interval in the downstream direction of the rotation direction of the image carrier of the cleaning member.

[0008]

In the image forming apparatus constructed as described above, each layer of the cleaning member composed of the laminated body has a function of charging, discharging, etc., respectively, and functions independently or in cooperation with the function of another layer or member. The surface of the image bearing member is miniaturized by charging the surface of the image bearing member with a charging layer having a function of charging at least the surface of the image bearing member, and the surface of the image bearing member is rotated even when the image bearing member rotates at high speed. In this way, high-quality image formation is performed by sufficient charging and uniform charging.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic view showing a main configuration of an image forming unit of an image forming apparatus to which the present invention is applied, and a blade-shaped cleaning member 1 constitutes a cleaning device 2. The cleaning member 1 is formed of a laminated body in which different materials are laminated in the plate thickness direction in the plate thickness direction, and carries a toner image 4 and rotates in an arrow A direction by a drive source (not shown) (photoreceptor). The tip of the drum 3 is in sliding contact with the surface of the image carrier so as to scrape off the residual toner 4a remaining on the surface of the drum 3.

The cleaning member 1 is formed into a plate shape by laminating and integrating a charging layer 1a having a triangular cross section and a charge eliminating layer 1b. The charging layer 1a to which a bias is applied uniformly charges the surface of the image carrier 3 and an electrostatic latent image formed on the surface of the image carrier 3 by the exposure light from the exposure unit 6. Is visualized by the toner from the developing unit 7 to become the toner image 4. The toner image 4 is transferred onto a transfer paper 9 by a roller-shaped transfer means 8 to which a bias is applied, and is fixed by a fixing means 10. The transfer sheet 9 on which the image has been formed in this way is ejected by the ejecting means 11 and accommodated in an ejecting tray or the like.

On the other hand, the residual toner 4a remaining on the surface of the image carrier 3 after the toner image 4 is transferred onto the transfer paper 9 is
The toner carrying screw 1 is scraped off by the static elimination layer 1b which constitutes the cleaning member 1 and is grounded to the ground.
2 is conveyed in the direction orthogonal to the paper surface and is conveyed to the outside of the cleaning device 2.

FIG. 2 is a sectional view showing a concrete example of the structure of the cleaning member 1 shown in FIG.
Is a charging layer 1a to which a bias is applied to uniformly charge the surface of the image bearing member 3, and a charge eliminating layer 1b which is grounded to ground and scrapes off the residual toner 4a remaining on the surface of the image bearing member 3.
The thin film-shaped insulating layer 1c having a function of electrically insulating the charging layer 1a and the static elimination layer 1b is provided between the facing surfaces of the charging layer 1a and the static elimination layer 1b. Since the cleaning member 1 of this embodiment has a function of scraping off the residual toner and the like at the contact portion with the image carrier, it has a cleaning function in addition to the charging and discharging functions.

The charging layer 1a and the static elimination layer 1b are made of acrylic rubber, epichlorohydrin rubber, silicon rubber or the like in which carbon powder is dispersed, and the intermediate insulating layer 1c is made of only silicon rubber. use.

FIG. 3 is a sectional view showing another example of the structure of the cleaning member of the present invention.
It has a plate shape in which a thin plate-shaped charging layer 1a and a thin plate-shaped static elimination layer 1b are laminated and integrated. In this embodiment, the static elimination layer 1b
As a light-transmissive material, for example, urethane rubber is used, the light from the light source 13 provided at the end of the static elimination layer 1b is radiated to the surface of the image carrier 3 through the static elimination layer 1b to perform the static elimination. I am supposed to do it. Since the charging layer 1a is made of silicon rubber that is made conductive by dispersing carbon powder, light from the light source 13 or the like does not pass therethrough, and the charging function is not disturbed by the light. . A reflective layer having light reflectivity may be provided between the charging layer 1a and the static elimination layer 1b, or a material having light reflectivity may be used for the charging layer 1a.

FIG. 4 is a view showing the structure of a cleaning member according to another embodiment of the present invention. The cleaning member 1 has a plate-shaped cleaning layer 1d having a protruding tip and a plate-shaped charging layer having a retracted tip. 1a is integrally laminated, and the multi-stage edge portion 5 is provided at the end portion thereof. Therefore, the contact condition that is good for cleaning to scrape off the residual toner 4a remaining on the surface of the image carrier 3 is obtained. As a result, good contact conditions can be obtained in which the surface of the image carrier 3 is sufficiently and uniformly charged, and both surfaces are contacted in a better condition.

FIG. 5 is a structural explanatory view of another embodiment of the present invention. A charging blade 1f is provided at a predetermined interval in the downstream direction of the rotation direction A of the image carrier 3 of the cleaning member 1. is there. The cleaning member 1 is a plate-shaped charging layer 1a.
And the plate-shaped charge removal layer 1b are joined and integrated via the insulating layer 1c. The static elimination layer 1b projects as shown in the figure to form a multi-step edge portion 5. Charging layer 1a
A DC power supply 14 is connected to the charging blade 1f, and a DC / AC superimposing power supply 15 is connected to the charging blade 1f, so that the surface of the image carrier 3 is gradually charged without being charged at once. Therefore, even if the image carrier 3 rotates at a high speed, the surface of the image carrier 3 is sufficiently and uniformly charged.

For example, in the conventional structure as shown in FIG. 7, reference numeral 101 is a charging blade and 102 is a cleaning blade, and the surface of the image carrier 103 rotates in the direction of arrow A at a high linear velocity of 300 mm / sec. When
When the DC component of the applied voltage is 0.8 KV, the AC peak-to-peak voltage is 2 KV, and the frequency is 1 KHz by the superimposed power source 115 of DC and AC to the charging blade 101,
The characteristic of the charging potential in the longitudinal direction of the surface of the image carrier 103 is as shown by the broken line in FIG.

In the embodiment of the invention shown in FIG. 5,
The surface of the image carrier 3 has a linear velocity of 300 mm / se in the direction of arrow A.
During high speed rotation of c, the voltage applied to the charging layer 1a is set to 0.5 KV by the DC power supply 14 and the charging blade 1f is rotated.
Is 0.8 KV for the DC component of the applied voltage, 2 KV for the AC peak-to-peak voltage, and 1 for the frequency by the superimposed power source 15 of DC and AC.
As shown by the solid line in FIG. 6, the characteristics of the charging potential in the longitudinal direction of the surface of the image carrier 3 when applied as KHz are as shown in the solid line in FIG. That is, sufficient and uniform charging is performed.

[0019]

Since the present invention is configured as described above, each layer in which a cleaning member is formed into a laminated body has its own function, and functions independently or in cooperation with the function of another layer or member. Since the surface of the image bearing member is charged by the charging layer having the function of charging at least the surface of the image bearing member, downsizing can be achieved, and even when the image bearing member rotates at a high speed, High-quality image formation is performed by performing charging or uniform charging.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a main part of an image forming apparatus showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a main part of an image forming apparatus showing another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a main part of an image forming apparatus showing another embodiment of the present invention.

FIG. 5 is an explanatory diagram of a main part of an image forming apparatus showing another embodiment of the present invention.

FIG. 6 is a graph showing the characteristics of the charging potential in the longitudinal direction of the surface of the image carrier of the image forming apparatus of another embodiment of the present invention and the conventional image forming apparatus for comparison.

FIG. 7 is an explanatory diagram of a main part of a conventional image forming apparatus.

[Explanation of symbols]

1 ... Cleaning member, 1a ... Charging layer, 1b.
..Static elimination layer, 1c ... Insulating layer, 1d ... Cleaning layer, 1e ... Cleaning blade, 1f ... Charging blade, 2 ... Cleaning device, 3 ... Image carrier, 4. ..Toner image, 4a ... Residual toner, 5.
..Multi-stage edge portions, 6 ... exposure means, 7 ... developing means, 8 ... transfer means, 9 ... transfer paper, 10 ... fixing means, 11 ... paper ejecting means, 12 ... Toner transport screw, 13 ... Light source, 14 ... DC power supply, 15
... Superposed power source of direct current and alternating current, 101 ... Charging blade, 102 ... Cleaning blade, 103 ...
Image carrier, 115 ... DC and AC superimposed power source.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03G 21/06

Claims (6)

[Claims] 1. An image forming apparatus comprising a plate-shaped cleaning member which is in sliding contact with the surface of the image carrier to scrape off residual toner remaining on the surface of the image carrier, wherein the cleaning member is at least an image. An image forming apparatus comprising a charging layer having a function of charging the surface of a carrier. 2. The plate-shaped cleaning member has the charging layer on the side facing the image carrier, and has a function of removing the charge on the surface of the image carrier on the side not facing the image carrier. The image forming apparatus according to claim 1, further comprising a charge eliminating layer. 3. The cleaning member has an insulating layer having a function of electrically insulating the charging layer and the static elimination layer between the charging layer and the static elimination layer. Image forming device. 4. The image forming apparatus according to claim 1, wherein the cleaning member has the charging layer on at least a side facing the image carrier. 5. The image forming apparatus according to claim 1, wherein the cleaning member has a multi-step edge portion that scrapes off residual toner remaining on the surface of the image bearing member with multi-step edges. 6. The image forming apparatus according to claim 1, wherein at least one charging blade is arranged at a predetermined circumferential interval on the side of the cleaning member facing the image carrier. apparatus.