JP3121645B2 - Image forming device - Google Patents

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 a copying machine, a facsimile, a printer, etc., and more particularly, to a casing having an opening directed to the surface of an image carrier and supported detachably on the main body of the image forming apparatus. A cleaning member disposed in the casing so that a part thereof is exposed from the opening and comes into contact with the surface of the image carrier; and a sealing member provided at a lower edge of the opening. In a cleaning device that removes residual toner on the image carrier with
The present invention relates to prevention of toner scattering when taking out the cleaning device.

[0002]

2. Description of the Related Art FIG. 4A shows a configuration near a cleaning device in a conventional image forming apparatus. In the figure, the surface of a photosensitive drum 1 serving as a latent image carrier is driven to rotate counterclockwise by an arrow. A cleaning device 3 is provided so as to face the surface of the photosensitive drum 1. In this example, a fur brush roller 5 and a cleaning blade 8 are provided as cleaning members.

[0003] Here, the photosensitive member 1 is
Part of the toner removed from above accumulates in a space surrounded by the lower wall of the casing and the fur brush roller 5. The accumulated toner may fall or scatter outside the cleaning device to stain the inside of the image forming apparatus, or may fall directly on transfer paper passing below the cleaning device to cause stains on the image. Therefore, a seal 4 made of, for example, an elastic film is provided on the casing 3a so that the upper end edge contacts the photoconductor surface.

[0004] However, the deposited toner is transferred to the seal 4.
A toner reservoir A is formed in the vicinity, and when the height of the toner reservoir A becomes higher than the upper edge of the seal 4, when the cleaning device is removed from the image forming apparatus main body for maintenance such as cleaning, the seal is removed. There is a case where the sealing between the photoconductor 1 and the photoconductor 1 is lost, and the accumulated toner may fall out of the cleaning device from a gap generated between the upper edge of the seal 4 and the photoconductor 1.

For example, in FIG. 4A, when the cleaning device is taken out to the right side of the drawing while the photoreceptor 1 is left in the apparatus, the tip of the seal 4 and the photoreceptor are taken out at the time of taking out. Since one surface is separated from the other, the deposited toner falls from between the two surfaces. In FIG. 4A, the seal 4 and the photosensitive member are also removed when the cleaning device is taken out above the paper surface (withdrawn in the axial direction of the photosensitive drum) while the photosensitive member 1 is left inside the device. In order to prevent each part from being damaged by rubbing against the surface of the photoconductor 1, the cleaning device moves to the right side of the drawing at the beginning of the removal operation so that the leading edge of the seal 4 is separated from the surface of the photoreceptor 1 and the guide mechanism of the cleaning device. FIG. 4 (b)
As shown in FIG.
A gap is formed between the leading edge of the photoconductor 1 and the surface of the photoconductor 1, from which the toner falls. Then, the toner dropped from the gap adheres to the transfer paper conveyance path formed below the cleaning device as described above, thereby generating back stains on the transfer paper and cleaning the inside of the device during maintenance. There was a problem that the burden on the user was increased.

In order to solve such a problem, in the conventional example shown in the drawing, a toner receiving box 10 having an upper opening for receiving toner dropped from a gap between the surface of the photosensitive drum 1 and the upper edge of the seal 4 is provided. I was

However, according to this configuration, since the toner receiving member has a box shape, there is a problem that a relatively large space is required, which hinders downsizing of the image forming apparatus.

Further, Japanese Patent Application Laid-Open No. 3-69984 discloses that
When the cleaning device is removed from the main body of the image forming apparatus for maintenance such as cleaning, the toner in the toner reservoir A formed near the seal 4 is prevented from falling from the gap between the seal 4 and the surface of the photosensitive drum 1. In order to prevent this, before removing the cleaning device, a toner removing rod for breaking the toner pool A and removing toner from the vicinity of the seal 4 is used.
A cleaning device disposed near a seal member in the cleaning device is disclosed.

However, even with this configuration, the toner in the vicinity of the seal 4 cannot be completely removed, and the toner that cannot be removed may fall from the gap. Further, in order to enhance the toner removing function, a sheet plate extending in a radial direction is fixed to the toner removing rod and the toner removing rod is rotated, but according to this, the leading edge of the sheet plate is rotated. Thus, there is a risk that the surface of the photosensitive drum 1 may be damaged.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object the following:
When removing the cleaning device from the apparatus main body, toner accumulated near the seal member provided at the lower end edge of the casing opening can be prevented from scattering into the image forming apparatus, and the image forming apparatus can be downsized. To provide an image forming apparatus capable of performing the following.

[0011]

In order to achieve the above object, the present invention is directed to a casing provided with an opening facing the surface of an image carrier and detachably supported on an image forming apparatus main body; A cleaning member disposed in the casing so that a part thereof is exposed from the opening and comes into contact with the surface of the image carrier; and a sealing member provided at a lower edge of the opening. An image forming apparatus having a cleaning device that removes residual toner on an image carrier with a member receives toner that falls from between the seal member and the surface of the image carrier when the cleaning device is removed from the image forming apparatus main body. the receiving member, and a plate-like member facing the image bearing member surface leading end edge with a following distance 1 mm, and, separately from the image forming apparatus main body with the cleaning device the plate-like member According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the plate-like member is provided with a sensor for detecting a toner adhesion amount on the surface of the latent image carrier. It is characterized in that it is detachable from the image forming apparatus main body by being integrated with a member facing the surface of the latent image carrier such as a separation claw and detachably supported by the image forming apparatus main body. , Claim 3
According to the present invention, in the image forming apparatus according to the first aspect, in a state in which the cleaning device is attached to a predetermined position of the image forming apparatus main body, the locking that disables removal of the plate-like member from the image forming apparatus main body is disabled. The invention according to claim 4 is characterized in that the plate-shaped member has a thickness in the range of 0.1 mm to 0.5 mm and a JIS hardness of 70 ° on an A scale. It is characterized by being constituted by a thermoplastic urethane sheet within a range of from 96 to 96 °.

[0012]

In the image forming apparatus of the present invention, when the cleaning device is taken out of the image forming apparatus main body, the cleaning device is removed from the gap between the leading edge of the seal member provided at the lower edge of the casing opening and the surface of the latent image carrier. The dropped toner is received by the plate-shaped toner receiving member, thereby preventing the toner from scattering into the image forming apparatus. The plate-shaped toner receiving member is appropriately removed from the image forming apparatus main body and cleaned.

[0013]

An embodiment of the present invention will be described below.
FIG. 1 is a front view illustrating a main part of the image forming apparatus according to the present embodiment. In FIG. 1, an image made of toner powder is created on the surface of a photosensitive drum 1 serving as an image carrier by an image forming unit (not shown), and is transferred to transfer paper by a transfer unit 2, and the residual toner is left attached thereto. It moves to the position of the cleaning device 3. In the cleaning device 3, the toner is removed from the photoreceptor drum 1 by passing through the seal 4 on the entrance side of the cleaning device 3 and electrically sucking and / or mechanically rubbing by the fur brush roller 5 for cleaning. The toner powder attached to the fur brush roller 5 is removed by the flicker member 6. The toner powder removed from the fur brush roller 5 is discharged out of the casing 3a of the cleaning device by rotation of the toner discharge screw 7. The cleaning blade 8 contacts the photosensitive drum 1 downstream of the fur brush roller 5 in the rotation direction of the photosensitive drum 1, and removes toner that has passed through the fur brush roller 5 and toner that has reattached from the fur brush roller 5. It is removed and dropped on the upper part of the fur brush roller 5 below. The toner dropped on the fur brush roller 5 is also removed by the flicker member 6 in the same manner.

In the cleaning device 3 of this example,
A seal 4 is attached to the lower edge of the opening of the casing 3a. Further, in this example, the unit can be detached from the unit guide casing 20 having the rail 20a for guiding the upper part of the casing 3a of the cleaning device 3 so that the cleaning device can be taken out above the paper surface while the photosensitive drum 1 is left in the apparatus main body. It is supported by.

When the cleaning device 3 is taken out of the main body of the cleaning device, the toner falls from the gap between the seal 4 and the surface of the photosensitive drum 1 so as to receive the toner. A plate-shaped toner receiving member 21 extending to the end is provided. The toner receiving member 21 is fixed to a distal end of a holder 22 whose base end is slidably supported by a guide rail 20b formed on the unit guide casing 20, whereby
It is detachable from the unit guide casing 20.

The gap δ between the leading edge of the toner receiving member 21 and the surface of the photosensitive drum 1 is desirably set to 1 mm or less. This is because the horizontal axis is the gap δ, and the vertical axis is the amount of toner falling on the toner receiving member 21, that is, the amount of toner captured by the toner receiving member 21 (capture amount).
FIG. 2 shows experimental data obtained by calculating the conversion amount per unit length in the axial direction of the photosensitive drum and examining the relationship between the two.
This is because, as shown in the graph of (a), when the gap δ is larger than 1 mm, the trapped amount decreases sharply.

The toner receiving member 21 has, for example, a thickness in the range of 0.1 mm to 0.5 mm and a JI
It can be composed of a thermoplastic urethane sheet whose S hardness is in the range of 70 ° to 96 ° A scale. According to this, the toner can be sufficiently held by the strength of the waist, and
Even when the toner receiving member 21 is accidentally bumped against the surface of the photosensitive drum 1 when the toner receiving member 21 is taken out of the unit guide casing 20, the surface of the photosensitive drum 1 is not damaged.

For example, FIG. 2B shows a surface of the photosensitive drum 1 in the case where a toner receiving member 21 made of various thermoplastic urethane sheets having different thicknesses and hardnesses is prepared and is hit against the surface of the photosensitive drum 1. 4 shows the results of evaluation of the degree of damage of the. The vertical axis represents thickness, and the horizontal axis represents hardness. And for those with a clear scratch, ×
The evaluation result is indicated by a mark, a mark with slight scratches, and a mark with no scratches, respectively. Although not shown in this figure, when the thickness is less than 0.1 or when the hardness is less than 70 °, the toner receiving member 21 is too weak to drop toner. Therefore, considering the evaluation results in this figure together, when the hardness is in the range of 70 ° to 96 ° and the thickness is in the range of 0.1 mm to 0.5 mm, and preferably in the range of 0.1 mm to 0.2 mm, the toner fall is also reduced. And the damage to the surface of the photosensitive drum 1 can be suppressed.

In the above embodiment, the holder 22 of the toner receiving member 21 is slidably supported by the unit guide casing 20 so that the toner receiving member 21 is attached to the image forming apparatus main body separately from the cleaning device. As shown in FIG. 3A, an optical sensor 23 for detecting the amount of toner adhering on the surface of the photosensitive drum 1 is fixedly provided on the holder 22, and a toner receiving member 21 is provided. And the optical sensor 23 may be integrated, so that a mechanism for detachably supporting them on the image forming apparatus main body may also be used.

Further, as shown in FIG. 3B, in order to forcibly separate the transfer material from the surface of the photosensitive drum 1 after the transfer, the leading edge is arranged in contact with or close to the surface of the photosensitive drum 1. Separation claw 24 which needs to be removed and cleaned appropriately
The toner receiving member 21 may be fixed to the holder 25, and the separation claw 24 and the toner receiving member may be integrated. According to this, since the holder 25 is detachably attached to the support shaft 26 by various known mechanisms, the separation claw 2 is
4, the toner receiving member 21 can be detachably supported by the image forming apparatus main body separately from the cleaning device 3.

Further, if the toner receiving member 21 is removed from the image forming apparatus main body before the cleaning apparatus 3 is removed from the image forming apparatus main body, the cleaning apparatus 3 is removed.
When the toner is taken out, toner falling from the gap between the leading edge of the seal 4 and the surface of the photosensitive drum 1 scatters into the image forming apparatus.
Thus, the toner receiving member 21 is
It is desirable to provide a mechanism for preventing the first member from being taken out. For example, as shown in FIG. 3C, the front end of the casing 3a of the cleaning device 3 is located on the front lower end of the casing 3a of the cleaning device 3 so that the front end is located on the front side of the front end of the toner receiving member 21 and its holder 22. A pull-out prevention knob 27 to which a base end is attached is provided.

[0022]

According to the present invention, when the cleaning device is taken out of the image forming apparatus main body, the cleaning device drops from the gap between the front edge of the seal member provided at the lower edge of the casing opening and the surface of the latent image carrier. The received toner is received by a plate-shaped toner receiving member, and the plate-shaped toner receiving member is appropriately removed from the main body of the image forming apparatus so that the toner can be cleaned. In addition, there is an excellent effect that scattering in the image forming apparatus can be prevented and the size of the image forming apparatus can be reduced.

In particular, the plate-like member is opposed to the surface of the latent image carrier such as a toner adhesion amount detection sensor or a separation claw on the surface of the latent image carrier and is detachably supported by the main body of the image forming apparatus. If it is made detachable to the main body of the image forming apparatus by integrating with the above, the mechanism for making the main body detachable to the main body of the image forming apparatus is also used by such a toner adhesion amount detection sensor and the plate-like member. can do.

If the cleaning device is mounted at a predetermined position on the main body of the image forming apparatus and locking means for preventing the plate-like member from being removed from the main body of the image forming apparatus is provided, the cleaning device can be provided. When the toner is removed from the image forming apparatus main body, it can be ensured that the toner receiving member is at a predetermined position, and the toner is removed by removing the cleaning device from the image forming apparatus main body in a state where the toner receiving member is removed from the image forming apparatus main body. Scattering can be prevented from occurring.

Further, the above plate-like member is formed to have a thickness of 0.1 mm.
If it is made of a thermoplastic urethane sheet having a JIS hardness within a range of 70 to 96 ° and a JIS hardness within a range of 70 ° to 96 °, toner spills and the plate-like member are taken out from the image forming apparatus main body. In this case, even if the surface of the latent image carrier is accidentally hit, the surface of the latent image carrier is not excessively damaged.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration near a lower wall of a casing of a cleaning device according to an embodiment.

2A is a graph showing a relationship between a gap between a leading edge of a toner receiving member and a surface of a photosensitive drum and an amount of captured toner in an embodiment, and FIG. 2B shows a change in hardness and thickness of the toner receiving member; 4 is a graph showing the result of examining the surface of the photosensitive drum for damage.

FIGS. 3A, 3B, and 3C are front views showing modified examples of a support mechanism of a toner receiving member and the like.

FIG. 4A is a front view showing a schematic configuration near a lower casing wall of a cleaning device according to a conventional example, and FIG. 4B is a schematic configuration near a lower casing wall of the cleaning device when the cleaning device is taken out from the apparatus main body. FIG.

[Explanation of symbols]

Reference Signs List 1 photosensitive drum, 3 cleaning device 3a casing, 4 seal 5 cleaning fur brush roller, 8 cleaning blade 10 toner receiving member, 20 unit guide casing 21 toner receiving box, 22 holder 23 optical sensor, 24 separating claw 25 holder, 27 extraction Prevention knob

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 21/10-21/12

Claims (4)

(57) [Claims] A casing provided with an opening facing the surface of the image carrier and detachably supported by the image forming apparatus main body;
A cleaning member disposed in the casing so that a part thereof is exposed from the opening and contacts the surface of the image carrier;
A seal member provided at the lower edge of the opening,
An image forming apparatus having a cleaning device that removes residual toner on an image carrier with the cleaning member, wherein toner that falls from between the seal member and the surface of the image carrier when the cleaning device is removed from the image forming device body Receiving member is formed of a plate-like member whose front edge is opposed to the surface of the image carrier with an interval of 1 mm or less , and the plate-like member can be detachably attached to the image forming apparatus main body separately from the cleaning device. An image forming apparatus, comprising: 2. The image forming apparatus according to claim 1, wherein the plate-shaped member is opposed to the surface of the latent image carrier such as a toner adhesion amount detection sensor or a separation claw on the surface of the latent image carrier and is detachably supported by the main body of the image forming apparatus. The image forming apparatus according to claim 1, wherein the image forming apparatus is detachable from the image forming apparatus main body by being integrated with the image forming apparatus. 3. The image forming apparatus according to claim 1, wherein said cleaning device is mounted at a predetermined position on said main body of said image forming apparatus. The image forming apparatus according to claim 1, wherein: 4. The plate-like member having a thickness of 0.1 mm to 0.5 mm and a JIS hardness of A scale 70
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is made of a thermoplastic urethane sheet whose angle is in a range of from about 90 degrees to about 96 degrees.