JPH04309967A - Process cartridge - Google Patents

Abstract

PURPOSE:To integrally unitize an abutting member on a movable member in a process cartridge or a proximate member, to facilitate the cleaning of an abutting part and to prevent positional accuracy and image forming setting condition from being changed in the case of reuse. CONSTITUTION:As to the process cartridge, an upper frame 7 and a lower frame 8, which are divided, are fitted and an electrostatic charging blade 2, a developing coat blade 5 and a cleaning blade 6 are provided in the upper frame 7. In the case of disassembly, it is sufficient to detach only the upper and the lower frames 7 and 8, and the blades 2, 5 and 6 are easily cleaned, then assembly is simple.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reusable process cartridge for an image forming apparatus using a removable process cartridge.

0002

2. Description of the Related Art In printers, copying machines, etc., for example, a primary charger, an optical system window for introducing image signals from a printer or image exposure from a copying machine, a developing device, a transfer section, and a cleaning device are installed around a photosensitive drum. The process cartridge is arranged as an integrated process cartridge, and its life span is reached when the developer in the process cartridge is consumed, and the process cartridge is replaced.

Conventionally, this type of process cartridge has been provided with a container-shaped frame as a developing device unit and a cleaning device unit, respectively, and the developing device has a developing device storage container containing a built-in developing means and a developer (toner) storage container bonded together. The cleaning device is integrated by welding, and is equipped with a cleaning blade and a scoop sheet at the opening of the container-shaped frame, and the frame members on both sides of the opening are extended to support the photosensitive drum, and these are attached to the process cartridge frame. It is fixed together with the primary charger by adhesive or welding. Therefore, there is no structure that takes into account reuse, and the conventional process cartridge requires additional work to remove developer that cannot be used once, such as a window for removing waste toner and a window for supplying developer toner. It was something.

0004

[Problems to be Solved by the Invention] In the conventional example described above, it is difficult to remove dirt in the nip of the abutment part and dirt in the narrow gap by cleaning without disassembly; Streak-like image defects ■ Sleeve contamination and fusion in the developing section ■ Charging failure due to foreign matter in the charging section ■ Photosensitive drum contamination, abrasion, and fusion in the cleaning section may occur, resulting in noticeable image defects .

[0005] Furthermore, although cleaning after disassembly work can alleviate the problems associated with the above-mentioned cleaning, it requires disassembling each unit and disassembling it down to the parts level, and (2) disassembly and reassembly are time-consuming. ■ The position, conditions, and accuracy of each part after disassembly cannot be guaranteed (1) Image density associated with appropriate durability cannot be obtained (2)
(3) The charging potential becomes abnormal and a charging failure occurs. (3) Various problems related to images may occur, such as drum contamination and increased abrasion due to poor cleaning or contact abnormalities.

[0006]

[Means for Solving the Problems] The present invention provides an abutment member for an image forming member, particularly a movable member in a process cartridge;
Or, by unitizing the adjacent members, 1. 2. Easily clean the contact area. This allows the positional accuracy and image formation setting conditions to remain unchanged even when reused.

The present invention provides an image forming apparatus characterized in that a charging member, a developer regulating member, and a cleaning member that are in contact with or close to an image carrier and a developer carrier can be integrally separated from a process cartridge. This is a process cartridge that can be attached to and detached from the device.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of the process cartridge of the present invention;
FIG. 2 is a longitudinal sectional view of an image forming apparatus equipped with the process cartridge PC of FIG.

The photosensitive drum 1 rotates as shown by the arrow in the figure, and is first uniformly charged by the charging blade 2. The charging blade 2 is made of a rubber elastic material and contacts the photosensitive drum 1 at the contact portion A, and is powered by a bias power source (not shown) (direct current + alternating current, alternating current has a peak-to-peak voltage that is more than twice the discharge starting voltage) to generate a desired voltage. The potential of is obtained from the DC component value. Next, a light image is obtained from the optical system 3 (light source 13 for irradiating the document 12 + mirror lens systems 14 and 15 or a laser beam (not shown)) to form an electrostatic latent image, and then the image is transferred to the developing section 16 .

[0010] In the developing section 16, the toner T is coated on the developing sleeve 4 by the developing coat blade 5 which presses against the developing sleeve 4 at the abutting portion B, and the developing sleeve 4 is developed. After development, the toner image is transferred to the transfer material P fed from the paper feed section 18 at the transfer section 17 at the bottom of the figure using the transfer charger 19, and unnecessary deposits such as residual toner remaining on the photosensitive drum 1 are transferred. is scraped off by a cleaning blade 6 provided in the cleaning section 20 and brought into contact with the photosensitive drum 1 at a contact portion C. The transfer material P onto which the unfixed toner image has been transferred is sent to the fixing device 21, where it is fixed, and then discharged outside the machine. This cycle is then repeated. For details of each part, the charging blade 2 has a thickness of about 1.0 to 3.0 mm and a resistance of 106 to 109 Ωc.
Urethane, silicon, hydrin, which has a conductivity of m
A protective layer based on nylon or urethane is applied to the contact surface side of a plate-shaped material such as EPDM rubber to a thickness of 5 to 100 μm.
It is fixed to the upper frame 7 and is pressed against the photosensitive drum 1 with a linear pressure of 5 to 30 g/cm using the bending elastic force of the rubber, and the pressure may be applied by a pressure mechanism such as a spring.

The developing coat blade 5 is made of rubber such as urethane or silicone, has a thickness of 0.5 to 3.0 mm, and contacts the developing sleeve 4 with a linear pressure of 3 g/cm to 45 g/cm.

The cleaning blade 6 is also made of rubber such as urethane or silicone, has a thickness of 1.0 to 3.0 mm, and contacts the photosensitive drum 1 with a linear pressure of 5 to 50 g/cm.

The frame of the process cartridge PC is entirely open at the upper edge of a single plane, and the bottom is open to the photosensitive drum 1.
In the container-shaped lower frame 8 in which the transfer portion 17 position is the opening 22,
An edge 23 surrounding the lower frame 8 is provided around the top plate 24, and the lower frame 8
It has a lid-shaped upper frame 7 into which the inner periphery of the edge 23 fits. The photosensitive drum 1 and the developing sleeve 4 are rotatably supported on the lower frame 8, and when installed in the electronic copying machine main body, the photosensitive drum 1,
The developing sleeve 4 is adapted to engage with a drive device on the main body side. The upper frame 7 has a top plate 24, a mounting part 25 for the cleaning blade 6, a mounting part 26 for the charging blade 2, a slit-shaped optical window 28 slightly shorter than the length of the photosensitive drum in the 1-axis direction, and a developer coat blade 5. A mounting portion 27 is integrally provided. Each of the mounting parts 25, 26, and 27 is plate-shaped in the illustrated cross section, is perpendicular to the plane of the drawing, and extends near the entire width of the upper frame 7, with both ends spaced apart from the edge 23 by the thickness of the side plate of the lower frame 8. . Each of the blades 2, 5, and 6 is attached by adhesive when attached to the respective attachment portions 25, 26, and 27. For example, the cleaning blade 6 has a member that contacts the photosensitive drum 1 and a mounting member made of sheet metal that are integrally molded. In this case, the mounting member and the mounting portion 25 of the cleaning blade are fixed by a member such as a self-tapping screw.

When the toner t in the developing section is consumed and the waste toner is stored in the cleaning section 20, the first life of the process cartridge PC ends, and it is removed from the main body of the image forming apparatus and collected.

In the disassembly work for regeneration, the upper frame 7 is attached to the lower frame 8.
The photosensitive drum 1 and the developing sleeve 4 other than the charging blade 2, developer coating blade 5, and cleaning blade 6 attached to the photosensitive drum 1 and the developing sleeve 4 remain, and the only thing to disassemble is to separate the upper frame 7 and the lower frame 8.

A charging blade 2 that contacts the photosensitive drum 1;
At least a nip is formed at the contact portions A, B, and C of the developer coating blade 5 and the cleaning blade 6, and if the nip portion and its vicinity are not cleaned, charging failure will occur at the contact portion A of the charging blade 2. Coating streaks may occur at the contact area B of the developing coating blade 5, and image defects such as poor cleaning and fusion may occur at the contact area C of the cleaning blade 6.

Conventionally, these parts were disassembled individually, but in the present invention, cleaning of this nip part is easy by only separating the upper and lower frames 7 and 8, and cleaning of the developing part and cleaning part can also be done from the upper direction in the figure. It also has the effect of being able to clean in one direction.

Furthermore, since each member that comes into contact with the photosensitive drum 1 is fixed to the upper frame 7, fitting portions 9 are provided on the upper and lower frames 7 and 8 as shown in FIG. By providing a position reference 11 for the developing sleeve, the accuracy can be improved.
Even if the upper frame 7 and the lower frame 8 are separated many times, the contact position is determined and a good image can be obtained. Upper and lower frame 7,
When assembling 8, apply a releasable seal to the mating surface. Upper frame 7
and screw the screw member into the lower frame 8 (not shown).

[0019]

[Other Examples] In the following, each blade is bonded to the upper frame 7 by adhesive or mechanically, but as shown in FIG.
, 6 are integrally formed with the upper frame 7, higher precision and joint stability can be obtained. This is each blade 2,5
, 6 may be molded of the same material and only the charging blade 2 may be surface-coated later, or each blade may be molded using a different material.

FIG. 5 shows a further simplified configuration in which the charging blade 2 and the cleaning blade 6 are the same and serve as a charging/cleaning member 30.

Further, the development coating blade 5 is attached to a frame 7, such as a resin film, a thin gold foil plate, or other members coated with resin.
A method of heat caulking may also be used.

FIG. 6 shows another process element, in which a charging member (2) is a roll that rotates under pressure against the photosensitive drum 1, which is an image carrier, due to its elasticity.

The developing coat blade 5 as a toner regulating member has an internal magnetic force, has a gap with the developing sleeve 4 of the toner carrier, and is a magnetic blade that regulates toner by magnetic force, or simply regulates the toner brush length. It is a non-magnetic blade.

In either case, it is not only easy to clean the abutting part or the opposing part, but also prevents curling and torque abnormalities due to the initial friction coefficient μP, especially when reusing the cleaning blade or the elastic developer coated blade. Easy to apply lubricant.

[0025]

[Effects of the Invention] The present invention makes it possible to integrally separate the charging member, developer regulating member, and cleaning member that are in contact with or close to the image carrier and developer carrier from the process cartridge, so that the process cartridge can be recycled. In this case, it is possible to separate and assemble easily and quickly, and it is easy to clean the parts of the charging member, developer regulating member, and cleaning member that contact or are close to the image carrier or developer carrier. In addition, it is easy to apply a lubricant to prevent curling due to an increase in the coefficient of friction and abnormal rotational force that drives the image carrier or developer carrier at an early stage when the portion is not used.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the invention.

FIG. 2 is a longitudinal cross-sectional view of an image forming apparatus equipped with the process cartridge of FIG. 1;

FIG. 3 is a perspective view showing positioning means for the upper and lower frames.

FIG. 4 is a longitudinal sectional view of another embodiment.

FIG. 5 is a longitudinal sectional view of still another embodiment.

FIG. 6 is a longitudinal cross-sectional view of another embodiment.

[Explanation of symbols]

1 Photosensitive drum 2　Charged blade 5 Developing coat blade 6 Cleaning blade 7 Upper frame 8 Lower frame

Claims (1)

[Claims] 1. An image forming apparatus characterized in that a charging member, a developer regulating member, and a cleaning member that are in contact with or close to an image carrier and a developer carrier can be integrally separated from a process cartridge. Removable process cartridge.