JPS6364790B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic copying apparatus using a photoreceptor belt.

In electrophotographic copying apparatuses, drum-shaped or endless belt-shaped photoreceptors are used as photoreceptors. An endless photoreceptor belt is usually stretched around appropriate pulleys or rollers and rotated in one direction by a predetermined driving means, during which time an electrostatic latent image is formed on the belt surface. is made into a visible image, and this visible image is transferred to transfer paper.

By the way, in this type of electrophotographic copying device using an endless belt-shaped photoreceptor, the upper body is configured to be openable and closable with respect to the main body of the copying device, and the photoreceptor belt is installed, and the upper body is attached to the main body of the device. When the belt is opened, the lower part of the belt is released.
Some devices are designed to facilitate equipment maintenance, jam paper removal, etc. FIG. 1 shows an example of this type of electrophotographic copying apparatus, and reference numeral 1 designates the entire copying apparatus. A contact glass 2 on which a document is placed and a pressure plate (not shown) that presses the document placed on the contact glass 2 are provided on the top surface of the copying apparatus 1, respectively. The upper body 1A of this copying apparatus 1 is
As shown by the chain line, it can be rotated upward. A charging/exposure unit 9 serving as an exposure device of the copying apparatus is arranged below the contact glass 2, and a photoreceptor belt device 10 made of an OPC photoreceptor or the like is further arranged below it.

The charging/exposure unit 9 includes an illumination lamp 1 that illuminates the document on the contact glass 2 in a slit shape.
1. An imaging optical system 12 consisting of a convergent light transmission array that transmits the illuminated original image to the photoreceptor belt 13 of the photoreceptor belt device; prior to exposure by the imaging optical system, the photoreceptor belt 13 is It consists of a charger 14 that charges to a specific polarity, a high voltage generator 15 for supplying high voltage power to the charger, and a support 16 that supports each of these devices substantially integrally.

In the charging/exposure unit 9, the imaging optical system 12 moves forward by a length L from the starting position St to the ending position E, and then returns to the starting position St.

The photoreceptor belt device 10 includes a drive roller 1
7. A driven roller 18, a tension roller 19, and a photoreceptor belt 13 wrapped around each of these rollers.
It is made up of. The above charging/exposure unit 9
When the photoreceptor belt 13 moves forward, the photoreceptor belt 13 is stopped, and the photoreceptor is charged by the charging charger 14, and exposed and scanned by the illumination lamp 11 and the imaging optical system 12 to form an original image. An electrostatic latent image corresponding to is formed. When the charging/exposure unit 9 reaches the terminal position E, the photoreceptor belt 13 rotates in the direction of the arrow, and the electrostatic latent image is visualized by the developing device 21.

The photoreceptor belt 13 consists of two segments: a first image forming area 13A extending from point a to point b, and a second image forming area 13B extending from point c to point d. After the exposure is completed, the rotating photoreceptor belt 13 is temporarily stopped when point a is located at point c and point b is located at point d. That is, the photoreceptor belt 13 has the distance between a and b and cd
The circumferential length l is determined so that the distances between the non-image forming areas are equal to each other, and the distances between a and d and between b and c of the non-image forming areas are also equal. Therefore, when the belt rotates after one exposure operation, the belt 13 will move by l/2.

When the photoreceptor belt 13 rotates by l/2, the electrostatic latent image formed in the first image forming area 13A at this time is visualized by the dry developing type developing device 21. This first visible image is held at the lower part of the belt.

On the other hand, the photoreceptor belt 13 rotates by l/2,
Once stopped, the charging/exposure unit 9 starts the second forward movement and moves to the second image forming area 13B.
forms an electrostatic latent image. When the unit 9 reaches the end position E, the photoreceptor belt 13 starts rotating again and moves by 1/2, during which time a second visible image is formed by the developing device 21.

When the photoreceptor belt 13 rotates again, the copy sheet sent out from the sheet cassette 5 is brought into contact with the first visible image that has been waiting until now, and transferred to the first visible image by the transfer charger 22. Visual images can be transferred. After this, the second visible image is placed on standby at the lower part of the belt. The copy sheet to which the first visible image has been transferred has the visible image fixed thereon by a fixing device 23, and is then discharged to the outside of the machine by a pair of paper discharge rollers 24.

Copy sheets (not shown) are stacked and stored in the sheet cassette 5, and the copy sheets are
Only the topmost sheet is sent out by the paper feed roller 25 and the separation claw 26, and the registration roller pair 27 controls the movement (rotation of the belt) of the visible image waiting at the lower part of the belt. Photoreceptor belt 1 in synchronization
3, and the visible image is transferred thereto.

After the transfer of the visible image, the photoreceptor belt 13 is cleaned by a cleaning device 28 disposed downstream of the transfer charger in these rotational directions.
The surface is cleaned and prepared for the next charging and exposure process.

As described above, while the photoreceptor belt 13 is stopped, the charging/exposure unit 9 is moved forward to form an electrostatic latent image, and then, while the belt is rotated by l/2, the latent image is formed. By repeating the process of making a visible image, waiting for a while, and transferring this visible image to the copy sheet the next time the belt rotates,
For example, multiple copies can be made from one original.

By the way, in this electrophotographic copying apparatus, an upper body 1A including a charging/exposure unit 9, a photoreceptor belt device 10, a cleaning device 28, etc. swings about a pivot 29 with respect to the copying device main body 1B. It can be opened and closed freely, and when the upper body 1A is opened, the movement path of the copy sheet from the pair of registration rollers 27 to the fixing device 23 is opened, and the lower part of the belt (lower hanging part) is moved against the apparatus body 1B. It feels liberating.

This configuration facilitates the removal of jammed copy sheets, the cleaning and maintenance of each device, and the replenishment of developer. On the other hand, when the upper body 1A is released, the lower part of the belt is exposed to the outside, and as a result, the photoconductor may suffer from photofatigue due to external light, fingerprints may occur if a finger touches the photoconductor belt carelessly, and foreign matter, dust, etc. may adhere to the belt surface. I do things. In particular, when a highly sensitive photoreceptor is used, the degree of photofatigue of the photoreceptor becomes significant.Furthermore, if fingerprints or the like form on the belt surface, oil from the hands may cause damage to the parts of the belt that are touched by fingers. Toner may get stuck to the surface.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic copying apparatus that eliminates the above-mentioned conventional drawbacks.

Hereinafter, the present invention will be explained with reference to FIG. 2 and subsequent figures.

In FIG. 2, the photoreceptor belt 13 includes a driving roller 17, a driven roller 18, and a tension roller 1.
9, and the drive system 31 shown in FIG.
It is adapted to be rotationally driven in the direction of arrow a. That is, the gear 32 of the drive system 31 meshes with a gear 33 fixedly mounted on the shaft 17a of the drive roller 17, and the belt 13 is rotationally driven by the rotation transmission function of each of these gears.

As shown in FIG. 3, the photoreceptor belt 13 is integrated with a gear 33 and a unit machine frame 34, and a guide portion 34a formed in the unit machine frame 34 is attached to the upper part of the belt. This gives flatness to the part. Tube shafts 34b and 34c are fixed to both sides of the side plate portion of the unit machine frame 34, and a handle 34d is formed between these by cutting and raising the side plate portion. Note that a tube shaft 34b and a pin 34c are also provided on the side plate portion on the opposite side of the unit machine frame 34.

In FIG. 2, the unitized photoreceptor belt 13 is detachably attached to a belt support cover 35, and the belt support cover 35 is constructed as follows. In FIG. 4, the belt support cover 35 includes guide side plates 36, 36,
It consists of a shielding member 38 to which it is fixed with screws, and a stay 41 to which earthing brushes 39, 39 are attached.

The belt support cover 35 is pivotally attached to the side plate 1A ₁ of the upper body 1A by a shaft 42.
It can swing freely around the center. The guide side plate 36 is formed with a recess 36a into which the tube shaft 34b of the belt unit device 30 (see FIG. 3) engages, and a recess 36b into which the pin 34c of the belt unit device 30 engages. Upper fuselage 1A side plate 1A ₁
A link mechanism 43 is provided between the belt support cover 35 and the belt support cover 35, and one end of an arm 44 of this mechanism is connected to the side plate _1A1 , and one end of the other arm 45 is connected to the belt support cover 35. There is.

For example, the side plate 1A ₁ is arranged above the overhang 36c of the guide side plate 36, and the side plate 1
A hook 47 is pivotally attached to A ₁ by a shaft 46, and a recess 47a formed in the hook 47
and the locking notch 47b engage with the pin 34c and the locked portion 36c ₁ at the end of the overhang 36c, respectively.

Here, in FIG. 2, the present electrophotographic copying apparatus is normally in a state where the upper body 1A is closed with respect to the copying apparatus main body 1B as shown in the figure, and during copying operation, as shown in FIG. The gear 3 of the belt unit device 30 is driven by the drive system 31 on the main body side of the copying machine.
3 is rotationally driven, and the photoreceptor belt 30 rotates in the direction of arrow a.

Here, in FIG. 2, the upper machine 1A is used to remove jammed copy sheets, maintain and clean each device, replenish developer, replace photoreceptors, etc.
, with the axis 29 as the center, as shown in FIG.
When the rotation is released, the upper body 1A stops at an arbitrary opening degree. In this state, it is extremely easy to replenish developer to the developing device 21, remove jammed copy sheets, maintain equipment, and replace the photoreceptor.

Next, let's talk about replacing the photoreceptor.
First, in FIG. 5, the belt unit device 30 mounted on the belt support cover 35 is taken out from the belt support cover. That is, as shown in FIGS. 5 and 6, the locking notch 47b of the hook 47 is connected to the locked portion 3 of the belt support cover
By engaging with 6c ₁ , the belt support cover 3
5 is rotated around the shaft 42 to prevent it from falling. In this position, the hook 47 is now manually pushed back against the elasticity of the spring 49 as shown in FIG. When rotated clockwise, the belt unit device 3
0 unit machine frame 34 and the cover 3
By releasing the locked portion 36c ₁ of the guide side plate ₃₆ of FIG. 5, the belt support cover 35 of FIG. , the belt supporting cover 35 slowly rotates clockwise around the shaft 42 and falls, and the bent link mechanism 43 opens, and as shown in FIG.
The motor is stopped at the position shown in the figure. in this case,
The cover 35 may not be rotated and dropped, but may be held by hand and rotated to the position shown in FIG. 8.

On the other hand, when you release your finger from the hook 47 that has been rotated to the position shown in FIG. 8).

Next, in FIG. 8, the belt unit device 3
0 (see FIG. 3), lift and rotate the right side portion of the belt unit device 30 about the tube shaft 34b, and pull out the pin 34c of the belt unit device 30 from the recess 36b of the cover 35. Next, the belt unit device 30 is moved to the right, and while the tube shaft 34b is pulled out from the recess 36a, the tube shaft 34b is slid along the inclined edge 36d ₁ of the guide side plate 36, and is slid onto the upper edge 36d ₂ . I'll ride it.

Next, as shown in FIG. 9, while sliding the tube shaft 34b using the upper edge _36d2 as a guide, the belt unit device 30 is moved to the right and completely extracted from the belt support cover 35. In this state, as shown in FIG. 3, the belt unit device 30 including the gear 33 is taken out and the OPC
The photoreceptor belt 13 made of a photoreceptor or the like can be replaced.

Next, when installing the belt unit device 30, first, as shown in FIG.
b along the upper edge _36d2 of the guide side plate 36, move the belt unit device 30 to the left, and as shown in FIG.
6a, the pin 34c is engaged with the other recess 36b, respectively. In this state, attaching the belt unit device 30 to the belt support cover 35 is as follows:
It means it's finished. Next, the belt support cover 35 is rotated counterclockwise about the shaft 42.

Then, the link mechanism 43 is gradually bent, and the pin 34c is attached to the free end inclined edge 4 of the hook 47.
It collides with 7c, pushes this part, and hooks 4
7 is rotated counterclockwise around the shaft 46 against the elasticity of the spring 49. Furthermore, as the belt support cover 35 is rotated, as shown in FIG.
The pin 34c engages with the recess 47a of the hook 47, and the locked portion _36c1 engages with the locking notch 47b.

In the above state, the upper fuselage 1A shown in FIG.
Rotate clockwise about the pivot 29 to close the upper body 1A as shown in FIG. At this time, the gear 3 of the belt unit device 30 shown in FIG.
3 is meshed with the gear 32 of the drive system 31. In this state, the copying apparatus is ready for operation.

In this way, in this copying apparatus, the belt unit device 30 is extremely easy to attach and detach.
In the conventional device, the belt unit device is attached to the upper body of the machine with screws or the like, and it is extremely troublesome to attach and detach the belt unit device.

Note that, as shown in FIG. 9, the guide side plate 36 of the belt support cover 35 is attached to the belt unit device 3.
It achieves a guiding function during attachment and detachment of the belt unit 0, and there is no need to lift the belt unit device itself when attaching and detaching, and the labor for attaching and detaching can be kept to a minimum. That is, the guide side plate 36 constitutes a kind of guide rail. In addition, as shown in FIG.
This serves to strengthen the longitudinal rigidity of the belt support cover 35. In addition, in FIG. 9, the handle 34d of the belt unit device 30 is a part that is held with fingers during attachment and detachment, but in addition, the handle 34d of the belt unit device 30 is a part that is held by the fingers during attachment and detachment. It also becomes a part that is received by the side plate 36.

When the belt unit device 30 shown in FIG. 3 is attached to the belt support cover 35 shown in FIG. This allows the photoconductor to be grounded. Note that the conductive layer is exposed to the outside on both side edges of the belt 13.

Incidentally, in this copying apparatus, not only the belt unit device can be easily attached and detached, but also the positional accuracy of the photoreceptor belt can be further improved. That is, in FIG. 2, the parallelism between the contact glass 2 and the photoreceptor belt 13 is maintained with high precision. The tube shaft 34b of the belt unit device 30 is attached to the belt support cover 3.
5, and the pin 34c of the belt unit device 30 fits into the recess 47 of the hook 47.
This is because it is correctly engaged with a without play. That is, the parallel accuracy of the photoreceptor belt 13 with respect to the contact glass 2 is determined by the parallelism between the tube axis 34b and the recess 36a.
, hook 47, and pin 34c. On the other hand, hook 47
The locking notch 47b locks the belt support cover 35 itself.

Conventionally, on the right end side of the belt unit device, the photoreceptor belt was positioned by bringing the projecting plate of the belt unit device into surface contact with the angle portion of the side plate of the upper body, but this method In this case, it has been difficult to set the position of the photoreceptor belt with high accuracy due to the influence of the mounting accuracy of the overhanging plate and the angle portion, their deformation, and the surface accuracy thereof.

On the other hand, in this copying apparatus, the hook 4
7 and the pin 34c, the position of the belt unit device is set by engagement with the pin 34c, so that the parallelism of the photoreceptor belt 13 with respect to the contact glass 2 can be easily maintained with high precision. Note that if the parallelism between the contact glass and the photoreceptor belt is not maintained with high precision, the imaging position by the imaging optical system and the surface of the photoreceptor will not match, resulting in blurred images.

Note that in FIG. 2, the gap formed between the developing sleeve 21a of the developing device 21 and the photoreceptor belt 13 must be maintained with high precision, but in this case, the tube shaft 34b must fit into the recess 36a with high precision. The shaft 42 is aligned with the shaft 42, and this part is the pivot joint.
Since the gap is close to , the gap can be maintained with high precision.

Here, the features of the present invention will be described.
As mentioned earlier, for the purpose of removing jammed copy sheets, maintaining and cleaning each device, replenishing developer, etc., the upper body 1A is installed as shown in Figure 5.
may be left open for a predetermined period of time. In this case, if the lower part of the photoreceptor belt 13 is exposed to the outside, the belt surface will be exposed to other external light that is not used for exposure, causing optical fatigue of the photoreceptor, or fingers touching the belt surface. Unnecessary touching may cause fingerprints, or dust or foreign matter may adhere to the belt surface, disturbing the image.

The present invention eliminates such problems, and includes:
Its characteristics, as shown in Figure 5, are:
A shielding member 38 is provided along the lower part of the belt so as to cover the surface of the lower part of the belt, and shields the lower part of the belt from the outside.

By the way, as shown in FIG. 1, the photoreceptor belt 13 has a first image forming area 13A and a second image forming area 13B, and has two photosensitive layer areas.
It has become a segment. Then, the shielding member 38 is arranged so as to substantially cover the segment from point d to point c.
is located. As shown in FIG. 4, both side portions 38a of the shielding member 38 also cover the side end portions of the photoreceptor belt 13. As shown in FIG.

With this configuration, it is possible to prevent light damage to the photoreceptor due to external light, contact with fingers on the belt surface, and adhesion of dust and foreign matter.

In addition, in FIG. 4, the belt support cover 35
A sheet guide member 48 made of a thin flexible material is attached to the end of the shielding member 38, and this member 48 guides the copy sheet coming out of the pair of registration rollers 27, as shown in FIG. The sheet is guided toward the photoreceptor belt 13 to perform transfer at the correct position.

In this way, the belt support cover 35 has a function of setting the belt unit device 30, a guide function when the belt unit device is attached and detached, a function of shielding the lower part of the photoreceptor belt, and a function of guiding the copy sheet. something that can be achieved simultaneously by a constituent body,
The configuration can be greatly simplified.

As described above, according to the electrophotographic copying apparatus of the present invention, a shielding member is provided at the lower part of the photoreceptor belt to cover the lower surface of the belt. When released from the outside, the belt surface is shielded from the outside by the above-mentioned shielding member, and that part is not exposed to the outside, so that the photoreceptor is protected from optical fatigue caused by external light and photoreceptor. It is possible to prevent fingers from touching the body part and from adhering foreign matter and dust to the body part.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram of an example of a conventional electrophotographic copying device, FIG. 2 is a cross-sectional configuration diagram of an electrophotographic copying device according to an embodiment of the present invention, and FIG. 3 is a belt provided in the same electrophotographic copying device. FIG. 4 is a perspective view of a belt support cover provided in the electrophotographic copying device; FIG. 5 is a perspective view of the electrophotographic copying device in which the upper body is opened; FIG. 6 is a perspective view of the unit device;
The figure is a configuration diagram of the locking mechanism of the belt unit device and the belt support cover, Figure 7 is an operational view from Figure 6 showing the state in which the locking mechanism is released by the same locking mechanism, and Figure 8 is the released upper fuselage. In contrast, Fig. 5 shows a state in which the belt support cover has exited from the upper body and the belt unit device can be taken out.
FIG. 9 is a diagram showing a state in which the belt unit device is taken out from the belt support cover. 1A... Upper body, 1B... Electrophotographic copying apparatus main body, 13... Photosensitive belt, 38... Shielding member.

Claims (1)

[Claims] 1. An electrophotographic copying device main body, an upper body that is provided to be openable and closable with respect to the electrophotographic copying device body, and an upper body that is installed on the upper body and when the upper body is opened to the electrophotographic copying device body. , a photoreceptor belt having a lower part of the belt facing the main body of the copying apparatus exposed to the outside, and a shielding member disposed along the lower part of the belt so as to cover the surface of the lower part of the belt and shielding the lower part of the belt from the outside. An electrophotographic copying apparatus comprising: