JPH0922231A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which surely prevents waste toner, scraped by a cleaning member, from scattering from the ends of the member. SOLUTION: The device is provided with at least photoreceptive drums (image carriers) 1a-1d, and a cleaner having the cleaning blade (cleaning member) 43 which reciprocates in the direction where each of the photoreceptive drums 1a-1d thrusts. At both ends of the cleaning blade 43, end seals 44 which move interlocking with the reciprocation of the cleaning blade 43 are arranged, and at each end of the cleaner, a fixed end-seal 46 is arranged. A relationship of L1-L2>=S is established between the distance L1 from the middle of the cleaning blade 43 in the thrusting direction to each end seal 44, the distance L2 from the middle of the cleaning blade 43 in the thrust direction to the end of each fixed end-seal 46, and a one-side reciprocating stroke S of the cleaning blade on each of the photoreceptive drums 1a-1d.

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 such as an electrostatic copying machine or an electrostatic printer which utilizes an electrostatic transfer process.

[0002]

2. Description of the Related Art In such an image forming apparatus, an electrostatic latent image formed on an image carrier is visualized as a toner image by a developing device, and the toner image is transferred from the image carrier to a transfer material. However, the untransferred toner remaining on the image carrier without being transferred is cleaned and removed by the cleaning device.

By the way, FIG. 6 shows a cleaning device 104.
The sealing structure between the image carrier 101 and the image carrier 101 is shown. However, in the cleaning device 104, in order to prevent the untransferred toner scraped off from the image carrier 101 by the cleaning member 143 from scattering, the end of the cleaning member 143 has an end. A partial seal 144 is provided.

In recent years, however, it has become clear that the cleaning member is clogged with dust, paper dust, etc., which causes cleaning failure and impairs the durability of the cleaning member itself. As a countermeasure against this, a mechanism has been proposed in which a cleaning member reciprocates in the thrust direction of the image carrier at the time of image formation (reciprocating operation), and attempts have been made to enhance the durability of the cleaning member against dust, paper dust, and the like.

An apparatus has also been proposed in which toner scattered from the end of the cleaning member is mechanically sucked and sucked out.

Further, in the cleaning device for performing the reciprocating operation of the cleaning member, the length of the image carrier in the thrust direction is made longer than the length of the cleaning member so that the end of the cleaning member does not rub against the end face of the image carrier.
Proposals have also been made to prevent toner scattering due to rubbing against the cleaning member at the end surface of the image carrier.

[0007]

However, in the cleaning device which employs the reciprocating operation of the cleaning member, the end portion is freed by the reciprocating operation of the cleaning member, which promotes the leakage of scattered waste toner from the end portion. It was.

Further, when the untransferred toner is scraped off, the reciprocating operation of the cleaning member increases the amount of laterally-running toner (toner that propagates along the contact edge of the cleaning member), which results in increasing the amount of toner accumulated at the end portion. Due to the rubbing of the end surface of the carrier and the seal on the peripheral surface, the accumulated toner was scraped up and scattered.

On the other hand, the untransferred toner scraped off by the cleaning member becomes floating toner in the waste toner box and diffuses toward the end portion, and scatters upward from the end gap generated during the reciprocating operation of the cleaning member. Then, the charging device was contaminated. Further, the floating toner was accumulated at the end portion, and the waste toner accumulated at the end portion was also rolled up and scattered by the conveying screw.

In order to solve the above problems, it has been proposed to forcibly mechanically suck the scraped off toner by the cleaning member. According to this proposal, the device becomes complicated and large, and the cleaning device is hermetically sealed. There was a tendency that there were many technical problems to be solved.

Further, it has been proposed that the cleaning member is shorter than the image carrier to carry out the end scattered seal by the surface of the image carrier, but according to this, the end seal is always in contact with and rubbed against the image carrier. Therefore, the end seal itself causes rubbing damage, and as a result, the end gap between the end seal and the image carrier increases, and the toner scattering from the end increases, and The addition of vibration to the carrier and the inhibition of normal rotation of the image carrier have been caused, which has been a cause of image defects.

The present invention has been made in view of the above problems, and an object thereof is an image forming apparatus capable of reliably preventing scattering of waste toner scraped off by a cleaning member from an end portion of the cleaning member. To provide.

Another object of the present invention is to prevent lateral movement of scraped-off waste toner due to the reciprocating operation of the cleaning member, and to prevent the toner accumulated on the end face of the image carrier from flying up and scattering. It is to provide an image forming apparatus capable of

Further, an object of the present invention is to prevent the generation of the end gap due to the reciprocating operation of the cleaning member and to surely prevent the end scattered toner from leaking from the waste toner box. To provide.

[0015]

To achieve the above object, the invention according to claim 1 is provided with a cleaning device having at least an image carrier and a cleaning member which performs a reciprocating operation in the thrust direction of the image carrier, In an image forming apparatus in which end seals interlocking with the reciprocating operation of the cleaning member are arranged at both ends of the cleaning member, and fixed end seals are arranged at the end of the cleaning device, a thrust direction of the cleaning member is provided. A distance L1 from the central portion to the end portion of the end seal, a distance L2 from the central portion in the thrust direction of the cleaning member to the end portion of the fixed end seal, and one side reciprocating stroke of the cleaning member on the image carrier. Between S and
It is characterized in that the relationship L1-L2 ≧ S is established.

Therefore, according to the first aspect of the invention, the overlap amount (L1-L2) between the end seal and the end fixed seal at the time of non-image formation is equal to or longer than the one-sided reciprocating stroke S of the cleaning member. Since (L1−L2 ≧ S) is set, even if the cleaning member reciprocates by the stroke S, the end seal and the end fixed seal always overlap each other, and as a result, a gap is formed at both ends of the cleaning member. Does not occur, and the scattering of the waste toner scraped off by the cleaning member from the end of the cleaning member is reliably prevented.

According to a second aspect of the present invention, in the first or second aspect of the present invention, a peripheral surface seal that abuts against the image carrier is attached on the metal plate of the end seal, and the peripheral seal is attached on the image carrier. Distance Ld from the thrust center to the image carrier edge
And Ld ≧ L3 + between the distance L3 from the thrust direction central portion of the cleaning member to the end of the peripheral surface seal and the one-sided reciprocating stroke S of the cleaning member.
It is characterized by establishing the relationship S.

Therefore, according to the second aspect of the present invention, the lateral seal reliably prevents the lateral movement of the scraped off waste toner due to the reciprocating operation of the cleaning member.
Further, since the distance Ld is set to (L3 + one side reciprocating stroke S) or more (Ld ≧ L3 + S), the end seal interlocked with the reciprocating operation of the cleaning member moves to the end side of the image carrier to the maximum extent. In addition, the peripheral seal does not rub against both ends of the image carrier, deformation of the peripheral seal is prevented, and the toner accumulated on the end face of the image carrier is prevented from flying up and scattering. Get off.

Furthermore, a third aspect of the invention is the waste toner box according to the first or second aspect of the invention, in which floating waste toner is shielded at both ends of the waste toner box for collecting the scraped toner by the cleaning member. An end seal is provided, and a distance L1 from the central portion of the cleaning member in the thrust direction to the end portion of the end seal, and the distance from the central portion of the cleaning member in the thrust direction to the central end portion of the waste toner box end seal. Between the distance L6 and the one-sided reciprocating stroke S of the cleaning member, L1-L6
It is characterized in that the relation ≧ S is established.

Therefore, according to the third aspect of the invention, between the distances L1, L6 and the reciprocating stroke S, L
Since the relationship of 1-L6 ≧ S is established, an end gap is not generated by the reciprocating operation of the cleaning member, and the waste toner box end seal prevents the floating toner in the waste toner box from moving to the end. As a result, it is possible to prevent the toner scattered at the ends from leaking from the waste toner box.

[0021]

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

<First Embodiment> FIG. 1 is a sectional view of an image forming unit of a multicolor electrophotographic copying machine according to the first embodiment of the present invention. FIG. 2 shows a cleaning device and a photosensitive drum in the same image forming unit. FIG. 3 is a front view showing a seal structure, and FIG. 3 is a schematic sectional view of a multicolor electrophotographic copying machine according to the present invention.

First, the image forming apparatus according to the present embodiment will be outlined with reference to FIG.

The image forming apparatus according to this embodiment is a multicolor electrophotographic copying machine having four image forming units Pa, Pb, Pc and Pd, and each of the image forming units Pa to Pd.
Have photosensitive drums 1a to 1d as image bearing members, respectively, and a primary charger 12 is provided around each of the photosensitive drums 1a to 1d.
a to 12d, pre-exposure light sources 13a to 13d, developing device 2a
To 2d, transfer chargers 3a to 3d, and cleaning device 4
a to 4d are arranged respectively. Also, the photosensitive drum 1
An endless transfer belt 30 as a conveying unit is arranged below the a to 1d, and the transfer material P is the transfer charger 3
It is supplied to the contact portions (transfer nip portion) between the a to 3d and the photosensitive drums 1a to 1d at an appropriate timing.

By the way, as shown in FIG. 1, each of the cleaning devices 4a to 4d has a cleaning blade 43 and a squeeze sheet 41 which come into counter contact and with which the photosensitive drums 1a to 1d come into contact with each other.
Further, in the waste toner box 48 of each of the cleaning devices 4a to 4d, a gear 42 for rotating and driving a waste toner conveying screw (not shown) which is long in the direction perpendicular to the paper surface of FIG. 1 is housed.

Thus, in the present embodiment, the photosensitive drum 1
As a to 1d, those having a diameter of 80 mm are used, and these are rotationally driven in the direction of arrow A in FIG. 1 at a peripheral speed (process speed) of 200 mm / sec. After the surface charges of the photosensitive drums 1a to 1d are removed by the pre-exposure light source 13a to 13d during the rotation process,
The surface thereof is uniformly charged by the primary chargers 12a to 12d, and an electrostatic latent image color-separated corresponding to the image exposure pattern is formed on the surface by exposure by the laser beam exposure device 11 (see FIG. 3). To be done.

By the way, the developing devices 2a to 2d of the respective colors have negatively charged toners of respective colors (yellow color, magenta color, cyan color, black color), and the respective developing sleeves 21 (see FIG. 1). A voltage (development bias) applied to each developing sleeve 21 by being carried on a carrying area and conveyed to a developing area close to the photosensitive drums 1a to 1d.
The toner of each color is made to adhere to the electrostatic latent images on each of the photosensitive drums 1a to 1d by a developing electric field formed by the electric field and the surface potentials of the photosensitive drums 1a to 1d, and the electrostatic latent images are visualized as toner images.

On the other hand, the transfer material P is carried on the transfer belt 30 as described above, and is transferred to the transfer chargers 3a to 3d and the photosensitive drum 1.
The photosensitive drums 1a to 1d are supplied at appropriate timing to contact portions (transfer nip portions) with the photosensitive drums 1a to 1d.
The toner images on the transfer material P are sequentially transferred by the transfer chargers 3a to 3d, and a full-color image is formed on the transfer material P.
Then, the transfer material P carrying the unfixed full-color image
Is conveyed to the fixing device 5 by the conveying belt 62, and after the full-color image is fixed by heat and pressure while passing between the fixing roller 51 and the pressure roller 52 of the fixing device 5, the paper is discharged outside the machine. It is discharged onto the tray 63.

The untransferred toner remaining on the photosensitive drums 1a to 1d without being transferred onto the transfer material P in the transfer step is removed by the cleaning devices 4a to 4d, and the photosensitive drums from which the untransferred toner is removed are removed. 1a ~
1d is used for the next image formation.

Thus, in the multicolor electrophotographic image forming apparatus according to this embodiment, the photosensitive drums 1a to 1d each having a diameter of 80 mm and a thrust direction length of 350 mm are used. ) Is 200 mm /
sec.

A urethane blade is used as the cleaning blade 43 provided in each of the cleaning devices 4a-4d, and its length in the thrust direction is 390 m.
is set to m, and these are configured to reciprocate (reciprocate) with a stroke of ± 1 mm in the thrust direction of each of the photosensitive drums 1a to 1d.

Next, the seal structure between the cleaning devices 4a-4d and the photosensitive drums 1a-1d will be described with reference to FIG.

As shown in FIG. 2, L-shaped end seals 44 are arranged at both ends of the cleaning blade 43.
The L-shaped end seal 44 is used for the cleaning blade 4.
It is configured to interlock with the reciprocating operation of 3.

On the other hand, fixed end seals 46 are arranged at both fixed ends of each of the cleaning devices 4a to 4d, and the cleaning blade 4 extends from the fixed end of each fixed end seal 46.
The length of 3 in the direction of the thrust center is set to 5 mm. As the fixed end seal 46, an acrylic brush is used to prevent fatigue due to the reciprocating operation.

Here, when the positional relationship between the L-shaped end seal 44 and the fixed end seal 46 interlocked with the reciprocating operation is clarified, the fixed end of the end seal 44 from the central portion in the thrust direction of the cleaning blade 43. Distance to the side L1
Is set to 210 mm, and the same cleaning blade 43
The distance L2 from the thrust direction center to the end of the fixed end seal 46 on the cleaning blade 43 side is 207 mm.
Is set to

Thus, in the present embodiment, the reciprocating operation of the cleaning blade 43 is turned off when the photosensitive drums 1a to 1d are not rotated during the pre-rotation, and at this time, the L-shaped end seal 44 and the end are The part fixed seal 46 is overlapped on one side by a width of ΔL = L1−L2 = 3 mm.

When the image forming operation is started, each cleaning blade 43 reciprocates with a stroke S of ± 1 mm in the thrust direction of each of the photosensitive drums 1a to 1d, but with the end seal 44 at the time of non-image forming. Since there is an overlap amount ΔL = 3 mm of the fixed end seal 46, the end seal 44 and the fixed end seal 46 overlap each other with a width of 2 mm at least on one side during the image forming operation.

Therefore, the overlap amount ΔL = between the L-shaped end seal 44 and the fixed end seal 46 at the time of non-image formation.
If L1-L2 is the length of one side reciprocating stroke S of the cleaning blade 43 or more (L1-L2 ≧ S),
Despite the reciprocating operation of the cleaning blade 43, no gap is generated at both ends of the cleaning blade 43, and scattered toner is reliably sealed.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. 4 is a front view showing a seal structure between the cleaning device and the photosensitive drum in the image forming apparatus according to the present embodiment. In this figure, the same elements as those shown in FIG. There is.

In this embodiment, the photosensitive drums 1a to 1a are placed on the L-shaped end seal 44 shown in the first embodiment.
The peripheral surface sealing member 45 that contacts the end portion of d is arranged. However, in the portions facing both ends of the photosensitive drums 1a to 1d,
The peripheral surface seal 45 is not provided. As the peripheral surface seal 45, a high molecular polyethylene sheet having a low friction coefficient with the photosensitive drums 1a to 1d is used.

The peripheral surface seal 45 is an L-shaped end seal 4.
It is affixed to the sheet metal of No. 4 and arranged so as to contact the tip of the cleaning blade 43, and the distance L3 from the central portion in the thrust direction of the cleaning blade 43 to the end of the peripheral surface seal 45 on the fixed end side is set to 198 mm. The distance Ld from the central portion of the cleaning blade 43 in the thrust direction to the end surfaces of the photosensitive drums 1a to 1d is 200 mm.
Is set to Further, the length of the circumferential surface seal 45 in the thrust direction is set to 6 mm, and the length in the tip direction (circumferential direction) is set to 3 mm. Here, the cleaning blade 43 has a stroke S = ± 1 mm as in the first embodiment.
The reciprocating action is done with.

Therefore, in the present embodiment, the distance Ld is (L
3+ one side reciprocating stroke S) or more (Ld ≧ L3 +
Since it is set to S), the cleaning blade 43
Even if the end seal 44 interlocked with the reciprocating operation of the above moves to the end side of the photosensitive drums 1a to 1d to the maximum, the peripheral surface seal 4
5 does not rub against both ends of the photosensitive drums 1a to 1d, deformation of the peripheral surface seal 45 is prevented, and the photosensitive drum 1 is prevented.
The flying and scattering of the toner accumulated on the end faces a to 1d due to the sliding friction was also suppressed.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a front view showing the seal structure between the cleaning device and the photosensitive drum in the image forming apparatus according to the present embodiment. In this figure, the same elements as those shown in FIGS. Attached.

In this embodiment, the waste toner box 48 is used.
The distance L1 from the central portion of the cleaning blade 43 in the thrust direction to the end of the end seal 44 is 2
The distance L6 from the central portion in the thrust direction of the cleaning blade 43 to the central end of the waste toner box end seal 47 is set to 195 mm. Here, the cleaning blade 43 is reciprocated with the stroke S = ± 1 mm as in the first and second embodiments.

The waste toner box end seal 47 is made of an acrylic member having a width of 10 mm and a height (photosensitive drum surface side) of 10 mm, and its thrust width is set to 20 mm.

In the above embodiment, the distances L1 and L6 and the reciprocal stroke S have a relationship of L1-L6 ≧ S, that is, the length between the end seal 44 and the end seal 47 of the waste toner box. Since the relationship of the reciprocating stroke S of the cleaning blade 43 or more is established, a gap is not formed between the end seal 45 and the waste toner box 48 due to the reciprocating operation of the cleaning blade 43.

Therefore, the untransferred toner scraped off by the cleaning blade 43 is collected in the waste toner box 48, and is conveyed and stays at the end while being scraped by the conveying screw, and the toner is scattered by the conveying screw and scattered. In this case, no end gap is generated due to the reciprocating operation of the cleaning blade 43, and the waste toner box end seal 47 prevents the floating toner in the waste toner box 48 from moving to the end. It is possible to enhance the sealing property of the toner scattered at the end portions from the inside.

[0048]

As is apparent from the above description, claim 1
According to the above-described invention, the overlap amount (L1-L2) between the end seal and the end fixed seal during non-image formation becomes the length (L1-L2 ≧ S) equal to or more than the one-sided reciprocating stroke S of the cleaning member. Since the setting is made, even if the cleaning member reciprocates by the stroke S, the end seal and the end fixed seal always overlap each other, and as a result, no gap is generated at both ends of the cleaning member, and the cleaning is performed. The effect that the waste toner scraped off by the member is reliably prevented from scattering from the end portion of the cleaning member is obtained.

Further, according to the second aspect of the invention, the lateral seal reliably prevents the lateral movement of the scraped waste toner due to the reciprocating operation of the cleaning member. Further, the distance Ld is (L3 + one side reciprocating stroke S) or more (L
Since d ≧ L3 + S), even if the end seal interlocked with the reciprocating operation of the cleaning member moves to the end side of the image carrier to the maximum, the peripheral seals slide on both ends of the image carrier. Without rubbing, the deformation of the peripheral seal can be prevented, and the scattering of the toner accumulated on the end surface of the image bearing member due to the sliding friction can be prevented.

Further, according to the invention described in claim 3, between the distances L1, L6 and the reciprocating stroke S, L1 is set.
Since the relationship of −L6 ≧ S is established, the end gap is not generated due to the reciprocating operation of the cleaning member, and the waste toner box end seal prevents the floating toner in the waste toner box from moving to the end. Therefore, it is possible to reliably prevent the toner scattered at the end from leaking from the waste toner box.

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming unit of an image forming apparatus (multicolor electrophotographic copying machine) according to a first embodiment of the present invention.

FIG. 2 is a front view showing the seal structure between the cleaning device and the photosensitive drum in the image forming unit of the image forming apparatus (multicolor electrophotographic copying machine) according to the first embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of an image forming apparatus (multicolor electrophotographic copying machine) according to the present invention.

FIG. 4 is a front view showing a seal structure between a cleaning device and a photosensitive drum in an image forming unit of an image forming apparatus according to a second embodiment of the present invention.

FIG. 5 is a front view showing a seal structure between a cleaning device and a photosensitive drum in an image forming unit of an image forming apparatus according to a third embodiment of the present invention.

FIG. 6 is a front view showing a seal structure between a cleaning device and a photosensitive drum in a conventional image forming apparatus.

[Explanation of symbols]

1a to 1d Photosensitive drum (image bearing member) 4a to 4d Cleaning device 43 Cleaning blade (cleaning member) 44 End seal 45 Peripheral surface seal 46 Fixed end seal 47 Waste toner box end seal 48 Waste toner box

Claims (3)

[Claims] 1. A cleaning device comprising at least an image carrier and a cleaning member that reciprocates in the thrust direction of the image carrier, and end seals interlocking with the reciprocating motion of the cleaning member are provided at both ends of the cleaning member. In the image forming apparatus, which is provided with a fixed end seal at the end of the cleaning device, the distance L1 from the central portion in the thrust direction of the cleaning member to the end of the end seal, and the cleaning member The relationship L1−L2 ≧ S is established between the distance L2 from the central portion in the thrust direction to the end of the fixed end seal and the one-sided reciprocating stroke S of the cleaning member on the image carrier. A characteristic image forming apparatus. 2. A peripheral seal abutting against the image carrier is attached on a sheet metal of the end seal, and a distance Ld from a central portion in the thrust direction on the image carrier to an end of the image carrier and the cleaning are performed. 2. The relationship Ld ≧ L3 + S is established between the distance L3 from the central portion in the thrust direction of the member to the end portion of the peripheral surface seal and the one-sided reciprocating stroke S of the cleaning member. Image forming apparatus. 3. A waste toner box end seal for shielding floating waste toner is provided at both ends of a waste toner box for collecting scraped toner by the cleaning member, and the end seal is provided from a central portion in the thrust direction of the cleaning member. Between the distance L1 to the end of the cleaning member, the distance L6 from the central portion in the thrust direction of the cleaning member to the central end of the waste toner box end seal, and the one-sided reciprocating stroke S of the cleaning member, L1-L6. The image forming apparatus according to claim 1 or 2, wherein a relationship of ≧ S 2 is established.