JPH11119548A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image forming device capable of ensuring a gap between a developing sleeve and an image carrier by the removal of toner sticking to parts where butting members abut on the image carrier, and steadily obtaining a satisfactory image free of image blur. SOLUTION: In the image forming device with butting rollers (butting members) 15 against the photoreceptor drum (image carrier) which are arranged at the ends of the developing sleeve 14, end blades 7 abut on the same parts of the photoreceptive drum as the butting rollers 15. Thus, because toner sticking to the parts where the butting rollers 15 abut on the photoreceptive drum 1 is removed by the end blades 7, a gap between the developing sleeve 14 and the photoreceptor drum is ensured, and a satisfactory image free of image blur can stably be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus provided with an abutting member for an image carrier disposed at an end of a developing sleeve.

[0002]

2. Description of the Related Art In a conventional image forming apparatus such as an electrostatic recording apparatus or an electrophotographic apparatus, a toner image is formed on an image carrier such as a photoreceptor, and the toner image is transferred to a transfer material. The residual toner on the carrier is scraped off by a cleaning blade of a cleaning device for cleaning. The cleaning blade is a molded product of rubber, metal, or the like, and physically cleans and removes toner adhered to the surface of the image bearing member by contacting the surface.

[0003]

However, in the prior art, the cleaning blade is not in contact with the entire area of the image carrier in the longitudinal direction, but only in the area where the toner image is formed on the image carrier. The length of the cleaning blade is shorter in the longitudinal direction than the image carrier, and in the area where the cleaning blade is not in contact with the image carrier, scattered toner floating in the image forming apparatus main body or the cleaning blade causes the cleaning blade to move away from the image carrier. There is a problem that the removed waste toner leaks little by little from the longitudinal end surface of the cleaning blade and the toner adheres to the end of the image carrier.

In addition, since an abutting roller is in contact with the end of the image carrier to assure a gap between the developing sleeve and the image carrier, toner adhering to the end of the image carrier abuts. The roller is crushed by the contact roller, and an uneven projection is generated on the image carrier. For this reason, the gap between the developing sleeve and the image carrier cannot be guaranteed, and there is a problem that image blur occurs.

[0005] The present invention has been made in view of the above problems, and its object is to remove toner adhering to the contact portion of the abutting member against the image carrier to remove the toner from the developing sleeve and the image carrier. An object of the present invention is to provide an image forming apparatus capable of guaranteeing a gap and stably obtaining a good image without image blur.

[0006]

According to a first aspect of the present invention, there is provided an image forming apparatus provided with an abutting member against an image carrier disposed at an end of a developing sleeve. The end blade is brought into contact with the same position as the position of the image carrier with which the butting member is in contact.

According to a second aspect of the present invention, in the first aspect of the present invention, the end blade is brought into contact with the generatrix of the image carrier at a predetermined angle.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the end blade is replaceable without removing it from the frame supporting the image carrier. .

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, a waste toner receiver for receiving the toner removed from the image carrier by the end blade is provided. And

Therefore, according to the present invention, since the toner adhering to the contact portion of the abutting member to the image carrier is removed by the end blade, the gap between the developing sleeve and the image carrier is ensured, and A good image without blur is stably obtained.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 is a sectional view of a main part of an image forming apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a photosensitive drum as an image carrier, and 2 denotes primary charging. Reference numeral 3 denotes an optical unit, 4 denotes a developing device, 5 denotes a transfer charger, 6 denotes a cleaning device, 7 denotes an end blade, 8 denotes a waste toner receiver, 9 denotes a cleaning blade, and 10 denotes a pre-exposure lamp.

Here, the image forming process will be described.

When a transfer material is conveyed to a pair of registration rollers 11 by a paper supply device (not shown), the transfer material is transferred to a transfer charger 5 by an optical unit 4 in synchronization with an image formed on the photosensitive drum 1. Transported to Then, the image on the photosensitive drum 1 is transferred onto a transfer material, and the transfer material on which the image has been transferred is conveyed to a fixing device 13 by a conveyance belt 12, and the image is fixed in the fixing device 13.

The toner not completely transferred to the transfer material by the transfer charger 5 is removed from the photosensitive drum 1 by the cleaning blade 9 in the cleaning device 6. Then, the potential on the photosensitive drum 1 is
Is charged again by the primary charger 2 to be used for the next image formation.

Next, the relationship between the developing device 4 and the photosensitive drum 1 will be described with reference to FIG. FIG. 2 is a plan view showing the relationship between the developing device 4 and the photosensitive drum 1.

In FIG. 2, reference numeral 14 denotes a developing sleeve of the developing device 4, and 15 denotes an abutting roller. In order to secure a gap of 50 μ between the photosensitive drum 1 and the developing sleeve 14, the outer diameter of the developing sleeve 14 is set to φ30 mm. The outer diameter of the abutting roller 15 is 30.05 mm, and the abutting roller 15 is brought into contact with the photosensitive drum 1 by a pressing means.

Here, the relationship between the butting roller 15, the photosensitive drum 1, the cleaning blade 9, and the end blade 7 in the longitudinal direction of the image forming area will be described.

The cleaning blade 9 includes the developing sleeve 1.
4, the end blade 7 is in contact with the photosensitive drum 1 at both ends of the cleaning blade 9 and in a region wider than the abutting roller 15 in the same positional relationship as the abutting roller 15 in the longitudinal direction.

Incidentally, the end blade 7 is an elastic rubber blade, and is not in a positional relationship parallel to the center line of the photosensitive drum 1 as shown in FIG. I have. The waste toner receiver 8 is arranged so that its longitudinal direction is located at the end of the end blade 7.

By setting the above positional relationship, the scattered toner generated by the rotation of the developing sleeve 14 or the waste toner scattered from the end of the cleaning blade 9 becomes an end on the photosensitive drum 1 (non-image forming area). The toner adhered to the area of the abutting roller 15 on the photosensitive drum 1 can be removed by the end blade 7, and the removed toner is removed by the end blade 7 as described above. Since the photosensitive drum 1 is in contact with the photosensitive drum 1 at a certain angle, it moves to the outside of the photosensitive drum 1 and falls into the waste toner receiver 8 to be collected.

In this manner, the waste toner on the photosensitive drum 1 is removed by the cleaning blade 9 and the end blade 7, and particularly, the toner adhering to the contact portion of the contact roller 15 against the photosensitive drum 1 is removed from the end blade 7. Therefore, a gap between the developing sleeve 14 and the photosensitive drum 1 is guaranteed, and a good image without image blur can be stably obtained.

When the durability of the cleaning blade 9 is deteriorated or when the waste toner receiver 8 is full of waste toner, the cleaning device 6, the primary charger 2, the photosensitive drum 1, and the like are integrally formed. Is pulled out of the image forming apparatus main body, and the screw 20 shown in FIG.
The waste toner receiver 8 can be easily replaced.

In this embodiment, an elastic rubber is used as the end blade 7, but a sheet material such as a PET sheet may be used.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a plan view showing the relationship between the developing device and the photosensitive drum of the image forming apparatus according to the present embodiment, and FIG. 5 is a front view showing the configuration of the end blade.

In this embodiment, the developing sleeve 1
The relationship between 4 and the longitudinal direction of the abutting roller 15 and the cleaning blade 9 is the same as that of the first embodiment. That is, the end blades 16 are located at both ends of the cleaning blade 9 and abut on the photosensitive drum 1 in an area wider than the abutting rollers 15 in the same positional relationship as the abutting rollers 15 in the longitudinal direction.

Thus, in the present embodiment, the end blade 16 has a positional relationship that overlaps both ends of the cleaning blade 9 in the longitudinal direction.

Next, the positional relationship between the end blade 16 and the photosensitive drum 1 will be described with reference to FIG.

The end blade 16 contacts the photosensitive drum 1 at an angle of about 15 ° so as to be inclined toward the center of the photosensitive drum 1 as shown in the figure. Since the end blade 16 overlaps the cleaning blade 9 in the longitudinal direction, the waste toner removed by the end blade 16 moves in the direction of arrow A shown in the drawing to move from the end of the end blade 16. The waste toner leaks onto the photosensitive drum 1, and the waste toner is further cleaned by the cleaning blade 9, so that the waste toner and the attached matter on the photosensitive drum 1 are reliably removed, and the same effect as in the first embodiment can be obtained.

In the first and second embodiments, the end blades 7 and 16 are in contact with the photosensitive drum 1 in the forward direction with respect to the rotational direction. .

[0031]

As is apparent from the above description, according to the present invention, in an image forming apparatus provided with an abutting member for an image carrier disposed at an end of a developing sleeve, the abutting member is provided. Since the end blade is brought into contact with the position of the image carrier in contact, the toner adhering to the contact portion of the abutting member against the image carrier is removed, and the gap between the developing sleeve and the image carrier is removed. , And a good image without image blur can be stably obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an image forming apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a plan view showing a relationship between a developing device and a photosensitive drum of the image forming apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a front view illustrating a configuration of an end blade of the image forming apparatus according to the first embodiment of the present invention.

FIG. 4 is a plan view showing a relationship between a developing device and a photosensitive drum of the image forming apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a front view illustrating a configuration of an end blade of an image forming apparatus according to Embodiment 2 of the present invention.

[Description of Signs] 1 photosensitive drum (image carrier) 7 end blade 8 waste toner receiver 14 developing sleeve 15 butting roller (butting member) 16 end blade

Claims (4)

[Claims] 1. An image forming apparatus comprising an abutting member for an image bearing member disposed at an end of a developing sleeve, wherein the abutting member is located at the same position as the position of the image bearing member in contact with the abutting member. An image forming apparatus having a blade abutted thereon. 2. The image forming apparatus according to claim 1, wherein the end blade contacts the generatrix of the image carrier at a predetermined angle. 3. The image forming apparatus according to claim 1, wherein the end blade is replaceable without being detached from a frame supporting the image carrier. 4. An image forming apparatus according to claim 1, further comprising a waste toner receiver for receiving the toner removed from said image carrier by said end blade.