JP3155402B2 - 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 electrophotographic or electrostatic recording type image forming apparatus, and more particularly, to a drum-shaped recording material carrier which carries a recording material and forms a plurality of colors formed on the image carrier. The present invention can be suitably embodied in a color image forming apparatus that transfers the toner image of the present invention onto the same recording material.

[0002]

2. Description of the Related Art Conventionally, a color image forming apparatus having a recording material carrier as shown in FIG. 7 is known. Referring to FIG. 1, the color image forming apparatus includes a photosensitive drum 1 which is an image carrier which rotates in the direction of an arrow, and further includes a corona charger 2, an optical system 3, a developing device 4, a recording material carrier around the photosensitive drum 1. A transfer device 5 as a body, a cleaning device 6, and the like are provided.

A corona charger 2 charges the photosensitive drum 1 uniformly, and an optical system 3 is a laser beam exposure device as shown in FIG. An image or a light image E corresponding to the image is irradiated on the photosensitive drum 1 to form a latent image on the surface thereof. The developing device 4 is, for example, a rotary developing device and has a central shaft 4b.
Has four developing units, namely, a black developing unit 4Bk, a cyan developing unit 4c, a magenta developing unit 4m, and a yellow developing unit 4y, and moves a predetermined developing unit to a developing position facing the photosensitive drum 1. To develop the latent image on the photosensitive drum 1 to form an image with a resin-based toner.

The transfer device 5 includes a transfer drum 5a, a transfer corona charger 5b, a suction corona charger 5c for electrostatically attracting a recording material, a suction roller 5g opposed to the suction corona charger, and an inner corona charger. 5d, an outer corona charger 5e, a pressing means 50, and the like.
a is rotatably supported by the apparatus main body, and a recording material carrying sheet 5f made of a dielectric material is cylindrically and integrally stretched in a peripheral opening area. As the transfer drum 5a rotates in the direction of the arrow, it is supplied from the recording material cassette 7 to a position facing the photosensitive drum 1 via a transport system, and is transferred to the transfer charger 5b.
Thus, the toner image formed on the photosensitive drum 1 is transferred to the recording material carried on the recording material carrying sheet 5f. At this time, a desired number of color images are transferred to the recording material, and a full-color image is formed.

When the transfer of the desired number of toner images is completed in this way, the recording material is separated from the transfer drum 5 a by the separating means 8,
Is discharged to On the other hand, the photosensitive drum 1 that has completed the transfer is
After the residual toner on the surface is removed by the cleaning device 6, the toner is again subjected to the image forming process.

Next, the transfer drum 5a of the transfer device 5 will be described with reference to FIG. The transfer drum 5a has a rotatable transfer frame 5h as its frame and a recording material carrying sheet 5f integrally stretched on the peripheral surface thereof. The transfer frame 5h has a front desk 5i provided at both ends and a rear desk 5i. It is composed of a desk 5k and a connecting member 5j for connecting both desks. The front desk 5i is provided with an opening 5m for exchanging the drum built-in parts. The recording material supporting sheet 5f is pressed by the pressing means 50.
The recording material carried on the photosensitive drum 1 is uniformly adhered to the photosensitive drum 1, and is therefore made of a flexible material.

Next, the pressing means 50 will be described with reference to FIG. The pressing means 50 is provided adjacent to the transfer corona charger 5b provided inside the transfer device 5 so as to substantially face the photosensitive drum 1, and has a flexible pressing force such as a polyester sheet. The member 50a, the pressing support plate 50b for holding the pressing member 50a, the support shaft 50c for rotatably supporting the pressing support plate 50b, and the ends of the pressing support plate 50b and the pedestal 5 of the pressing means 50, respectively.
0e and a pressure spring 50d connected to the pressure spring 50e. In the operating state of the pressing means 50, the pressing support plate 50b
The pressing member 50a is urged in the direction of arrow A with the support shaft 50c as a fulcrum by the force of the pressure spring 50d. The pedestal 50e that supports the pressing means 50 is slidably fitted to the internal frame 54 attached along the longitudinal direction of the transfer drum 5a by appropriate means.

By the way, as for the pressing means 50, the pressing member 50a is liable to be stained or set with the elapse of the use time of the apparatus. However, as is clear from FIG. 9, at least the pressing member 50a needs to protrude radially outward from the opening 5m of the front desk 5i in function, and the opening 5m of the transfer device is left as it is.
It is impossible to extract from. Therefore, the pressing means 50 has a configuration as described below.

That is, as shown in FIG.
The support shaft 50c is attached to the standing member 50j standing from the end face of the e as described above, and the supporting shaft 50c is attached to the standing member 5 as described above.
0j, extends outwardly, and has a release lever 50 at its end.
f is rotatably supported like a pendulum. The release lever 50f has a substantially triangular shape with one side being an arc, and an arc-shaped long hole 50g is partially formed along the arc.
During the operation of the device, the release lever 50f
Is a screw 50h through the right end of the arc-shaped long hole 50g in the drawing.
Is fixed to the standing member 50j. One end of a shaft 50i is fixed to a corner portion of the release lever 50f substantially opposite to the long hole 50g.
i is parallel to the support shaft 50c and the pressing support plate 50
The pressure spring 50b extends along the connection-side end face 50d.

When the pressing means 50 constructed as described above is pulled out of the transfer drum 5a during maintenance, as shown in FIG. 11, the screw 50h is loosened, and the release lever 50f is pivoted on the support shaft 50c as shown by an arrow in FIG. The shaft 50i is similarly rotated in the same direction.
The rotation of the shaft 50i causes the pressing support plate 50b
Is pushed up against the tensile force of the pressure spring 50d, and rotates in the direction of arrow C together with the pressing member 50a with the support shaft 50c as a fulcrum. Next, the release lever 50f is fixed by the screw 50h to maintain the state of FIG. 11, and the pressing means 50 can be extracted from the opening 5m.

[0011]

However, in the above configuration, an unskilled worker pushes the pressing means 5.
When performing the extraction work of 0, the extraction work is often performed without following the procedure of the release operation. As a result, the pressing member 50a interferes with the front desk 5i, and in the worst case, the pressing member 50a is pressed. There was a problem that the member 50a was damaged.

Accordingly, an object of the present invention is to fix a second unit, such as a pressing unit, from a first unit, such as a main body or a transfer device, unless the moving unit is operated when the second unit is detached. By constructing such that it is impossible to release from the state, when the second unit is pulled out for maintenance or the like, the projecting portion is not damaged due to erroneous operation by the operator, and the running cost of the apparatus is improved together with the maintainability of the apparatus. An object of the present invention is to provide an image forming apparatus capable of improving the image quality.

Another object of the present invention is to provide an image forming apparatus provided with a transfer device capable of completely preventing damage to the pressing member when the pressing means is pulled out.

[0014]

The above object is achieved by an image forming apparatus according to the present invention. In summary, according to the first aspect of the present invention, there is provided a first unit having an opening, and a second unit detachable from the opening, wherein the second unit is detachable from the second unit. An image forming apparatus comprising: a projecting member capable of projecting from the opening in a direction perpendicular to the direction; and a moving unit that moves the projecting member to a retracted position that fits in the opening. Having a fixing member for fixing to one unit, for extracting the second unit from the first unit,
When the moving means is moved from a position where the fixing member is concealed to a position where the fixing member is opened, the projecting member is moved to the retracted position.

According to one embodiment of the first invention, the projecting member is a flexible member. According to another embodiment, the fixing member is a screw. According to another embodiment of the first aspect of the present invention, the moving means includes a lever member, and in order to extract the second unit from the first unit, the moving unit is moved from a position where the fixing member is concealed to an open position. When the lever member is moved, the projecting member is moved to the retracted position. According to another embodiment of the first invention, the first unit includes a recording material carrier for carrying a recording material, and the image on the image carrier is recorded on the recording material carried by the recording material carrier. Transcribed. According to another embodiment,
During image transfer, the projecting member presses the recording material carrier toward the image carrier.

According to the second aspect of the present invention, a first unit including a recording material carrier for supporting a recording material, a second unit detachable from an opening provided in the first unit,
Wherein the second unit is a protruding member that can protrude from the opening in a direction orthogonal to the attaching / detaching direction of the second unit, and the image carrier is mounted on a recording material carried by the recording material carrier. A projecting member that presses the recording material carrier toward the image carrier when transferring the upper image, a moving unit that moves the projecting member to a retracted position that fits in the opening,
Wherein the first unit includes a regulating member that regulates the movement of the second unit and the moving unit in the attaching / detaching direction, and the first unit is moved to remove the second unit from the first unit. When the means is moved from a position regulated by the regulating member to a position opened, the projecting member is moved to the retracted position.

According to one embodiment of the second invention, the projecting member is a flexible member. According to another embodiment of the second invention, the moving means comprises a lever member,
When the lever member is moved to a position where it is released from a position regulated by the regulating member in order to extract the second unit from the first unit, the projecting member is moved to the retracted position.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus according to the present invention will be described in more detail with reference to the drawings. In the embodiment described below, the present invention is applied to the color image forming apparatus described above with reference to FIG. 7, and the features of the present invention are shown in FIGS.
It is assumed that the present invention is embodied in a transfer device as shown in FIG. Therefore, the same members as those described above are denoted by the same reference numerals and description thereof will be omitted.

In FIG. 1, a pedestal 50e for supporting the pressing means 50 is slidably fitted to an internal frame 54 attached to the transfer drum 5a along the longitudinal direction by appropriate means. An upright member 50j is erected on the end surface of the pedestal 50e, and a support shaft 50c that supports the support plate 50b so as to be rotatably pressed against an appropriate position of the upright member 50j is supported. The pressing support plate 50b is connected to the pedestal 50e by a pressing spring 50d, and is urged clockwise about the supporting shaft 50c as a fulcrum. As a result, the pressing member 50a held by the pressing support plate 50b presses the recording material carrying sheet 5f stretched on the peripheral surface of the transfer drum 5a against the surface of the photosensitive drum 1 by the urging force of the pressing spring 50d. .

A release lever 51 for releasing the operating state of the pressing means 50 is attached to the standing member 50j of the pedestal 50e. The release lever 51 is formed integrally with a shaft 55 that penetrates the standing member 50j and extends to the back surface of the pressing support plate 50b, and a release cam 52 fixed to the tip of the shaft 55. Further, a fixing screw 53 for fixing the pedestal 50e to the inner frame 54 of the transfer device 5 is attached to the standing member 50j. The fixing screw 53 is arranged so as to overlap with the release lever 51 in the operating state of the pressing means 50, in other words, at a position where it is hidden by the release lever 51. The shape of the release cam 52 is such that when the release lever 51 is rotated,
Are formed so that the pressing support plate 50b is supported by the support shaft 50c as a fulcrum and is rotated counterclockwise against the urging force of the pressing spring 50d.

A similar standing member is provided at the other end (not shown) of the pedestal 50e, and the end of the support shaft 50c is supported.

Next, the operation of the pressing means 50 configured as described above will be described with reference to FIGS.
FIG. 2 illustrates the pressing means 50 in the operating state. It can be seen that the pressing member 50a is urged clockwise by the pressing spring 50d, and its tip extends beyond the opening 5m of the transfer drum 5a. At this time, the release cam 52 is at a position where it does not come into contact with the pressing support plate 50b. Further, the fixing screw 53 is covered by the end 51a of the release lever 51, that is, is positioned so as to be behind the end 51a. In such a state, it is impossible to loosen the fixing screw 53. Therefore, the pressing means 50 cannot be pulled out to the near side in the drawing, and, of course, the pressing member 50a and the front desk of the transfer drum 5a. 5i does not interfere, and it is possible to prevent the pressing member 50a from being damaged.

FIG. 3 shows the pressing means 50 in the released state. When the release lever 51 is rotated integrally with the release cam 52, the projecting portion of the pressing member 50a comes into contact with the convex portion of the release cam 52 against the pressing support plate 50b to resist the urging force of the pressing spring 50d. Then, it rotates to a position where it fits within the opening 5m. At this time, since the fixing screw 53 is exposed from the release lever 51, the fixing screw 53 can be loosened, so that the pressing means 50 can be pulled out from the transfer drum 5a.

As described above, only by releasing the pressing means 50, the fixing screw 53 can be loosened, and the pressing means 50 can be pulled out. That is, when the pressing means 50 is in the operating state as described above, it cannot be pulled out, so that interference between the pressing member 50a and the front desk 5i of the transfer drum 5a can be completely prevented.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. The description of the same members as those in the above embodiment will be omitted. In FIG. 4, a release lever 51 has a protrusion 51b protruding laterally on a side surface thereof.
The inner frame 54 has an extension 54a extending from its end face toward the front in the figure and further extending upward. At this time, the extending portion 54a of the internal frame 54 is located on the front side of the convex portion 51b of the release lever 51, that is, when the release lever 51 is pulled toward the front side, the convex portion 51b The release lever 51 cannot move any more because it is interfered by the extension 54a of the lever 54.

In such a configuration, when the pressing means 50 is in the operating state as shown in FIG. 5, even if the release lever 51 is moved to the near side in the drawing to pull out the pressing means 50 from the transfer drum, Projection 51b of release lever 51
Cannot be pulled out because it contacts the extension 54a of the internal frame 54. Therefore, interference between the pressing member 50a and the front desk 5i of the transfer drum 5a can be prevented.

On the other hand, in order to release the pressing means 50, as shown in FIG. 6, the release lever 51 is rotated integrally with the release cam 52, and the projection of the release cam 52 is pressed against the support. The protruding portion of the pressing member 50a is rotated to a position where the protruding portion of the pressing member 50a fits within the opening 5m against the urging force of the pressing spring 50d by contacting the plate 50b. At this time, since the convex portion 51b of the release cam 51 has moved to a position deviated from the position where it overlaps with the extending portion 54a of the internal frame 54, the pressing means 50 can be extracted from the transfer drum 5a. .

As described above, it is possible to extract the pressing means 50 only by setting the pressing means 50 to the release state. When the pressing means 50 is in the operating state as described above, it cannot be extracted. The interference between the pressing member 50a and the front desk 5i of the transfer drum 5a can be completely prevented.

In the above embodiment, the description has been given of the case where the characteristic portion of the present invention is embodied in the transfer device. However, the second unit can be detached through the opening formed in the main body or the first unit. The present invention can be applied to the means configured as described above.

[0030]

As is apparent from the above description, the present invention relates to A.I. A first unit having an opening, and a second unit detachable from the opening, the second unit having a projecting member capable of projecting from the opening in a direction orthogonal to the attaching / detaching direction of the second unit; A moving unit for moving the protruding member to a retracted position that fits in the opening, the fixing unit fixing the second unit to the first unit, and extracting the second unit from the first unit. When the moving means is moved from the position where the fixing member is concealed to the position where the fixing member is opened, the projecting member is moved to the retracted position. A first unit provided with a recording material carrier for supporting the recording material, and a second unit detachable from an opening provided in the first unit;
The unit is a protruding member that can protrude from the opening in a direction orthogonal to the attaching / detaching direction of the second unit, and is configured to transfer the image on the image carrier to the recording material carried on the recording material carrier. In an image forming apparatus including: a projecting member that presses a body toward an image carrier; and a moving unit that moves the projecting member to a retracted position that fits in the opening, the first unit is a detachable direction of the second unit and the moving unit. A restricting member for restricting movement to the first unit. When the moving means is moved from a position restricted by the restricting member to a position opened to extract the second unit from the first unit, the projecting member moves to the retracted position. Since it is configured to be moved, when the second unit is extracted from the first unit, it is possible to reliably prevent the projecting member from being damaged by an erroneous operation by the operator,
Therefore, the running cost does not increase.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a pressing means of a transfer device according to the present invention.

FIG. 2 is a side view showing an operation state of the pressing means of FIG. 1;

FIG. 3 is a side view showing a released state of the pressing means of FIG. 1;

FIG. 4 is a perspective view showing another embodiment of the pressing means according to the present invention.

FIG. 5 is a side view showing an operation state of the pressing means of FIG. 4;

FIG. 6 is a side view showing a released state of the pressing means of FIG. 4;

FIG. 7 is a cross-sectional view showing a conventional full-color electrophotographic apparatus.

FIG. 8 is a schematic perspective view showing a conventional transfer device.

FIG. 9 is a side view showing a pressing unit of a conventional transfer device.

FIG. 10 is a perspective view of an essential part showing an operation state of the pressing means of FIG. 9;

FIG. 11 is a perspective view of a main part showing a released state of the pressing means of FIG. 9;

[Explanation of symbols]

 5a 1st unit (transfer drum) 5m opening 50 2nd unit (pressing means) 50a pressing member 50d pressure spring 50e pedestal 51 release lever 51b convex portion 52 release cam 53 fixing screw 54 internal frame 54a extension portion

Claims (9)

(57) [Claims] A first unit having an opening; and a second unit detachable from the opening.
An image forming apparatus including: a projecting member capable of projecting from the opening in a direction orthogonal to the attaching / detaching direction of the second unit; and a moving unit that moves the projecting member to a retracted position that fits in the opening. In the above, further comprising a fixing member for fixing the second unit to the first unit, in order to extract the second unit from the first unit, the moving means is moved to a position where the fixing member is opened from a position where the fixing member is concealed. The image forming apparatus according to claim 1, wherein when moved, the projecting member is moved to the retracted position. 2. The image forming apparatus according to claim 1, wherein said projecting member is a flexible member. 3. The image forming apparatus according to claim 1, wherein the fixing member is a screw. 4. The moving means comprises a lever member, and for extracting the second unit from the first unit,
The image according to any one of claims 1 to 3, wherein when the lever member is moved from a position where the fixing member is concealed to a position where the lever member is opened, the projecting member is moved to the retracted position. Forming equipment. 5. The image forming apparatus according to claim 1, wherein the first unit includes a recording material carrier for carrying a recording material, and an image on the image carrier is transferred to the recording material carried on the recording material carrier. Item 5. The image forming apparatus according to any one of Items 1 to 4. 6. The image forming apparatus according to claim 5, wherein at the time of image transfer, the projecting member presses the recording material carrier toward the image carrier. 7. A first unit having a recording material carrier for supporting a recording material, and a second unit detachable from an opening provided in the first unit, wherein the second unit is A projecting member projecting from the opening in a direction perpendicular to the attaching / detaching direction of the second unit, wherein the recording material carrier is used to transfer an image on the image carrier to a recording material carried by the recording material carrier; An image forming apparatus comprising: a protruding member that presses a body toward the image carrier; and a moving unit that moves the protruding member to a retracted position that fits within the opening. The first unit includes the second unit and A regulating member that regulates movement of the moving means in the attaching / detaching direction, wherein the moving means is opened from a position regulated by the regulating member in order to extract the second unit from the first unit. Moving to the position, the protruding member is an image forming apparatus characterized by being moved to the retracted position. 8. The image forming apparatus according to claim 7, wherein said projecting member is a flexible member. 9. The moving means includes a lever member, and is configured to extract the second unit from the first unit.
9. The projecting member is moved to the retracted position when the lever member is moved from a position regulated by the regulating member to a position released.
Image forming apparatus.