JPS6241332Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention includes an endless belt unit that includes an endless belt, a plurality of feed rollers that support and drive the endless belt, and a unit holding means that detachably holds the endless belt unit. The present invention relates to an endless belt support device.

The above-mentioned device is used in a recording device that performs recording work while driving a recording medium formed in the shape of an endless belt by a plurality of rollers. and electrophotographic methods.

Among these, in electrophotographic recording devices, an endless belt-shaped photoreceptor in which an organic or inorganic photoconductor is provided on a base film made of polyethylene terephthalate or the like is used as a recording medium.A conventional example of this device is presented below. At the same time, the drawbacks of the endless belt support device used there will be explained.

FIG. 1 is a cross-sectional view showing a schematic configuration of the entire electrophotographic recording apparatus. In the figure, the recording medium is configured as an endless belt-like photoreceptor 1 as described above. The photoreceptor 1 is supported by a plurality of (two in the figure) feed rollers 2 and 3, and is movable in the direction of arrow A by rotation of the rollers 2 and 3. The photoreceptor 1 is surrounded by the following devices: a charger 4 that charges the photoreceptor 1, and a charger 4 that appropriately exposes the charged photoreceptor 1 to form an electrostatic latent image on its surface. An exposure device 5 for exposing the latent image, a developing device 6 for making the latent image visible, a transfer device 7 for transferring the developed image onto recording paper, and a second exposure of the photoreceptor 1 after the transfer process. A static eliminator 8 for removing electric potential on the surface of the photoconductor 1 so that it can be used for
is located. Further, a paper storage box 11 having a recording paper 10 placed thereon is provided at the bottom of the recording apparatus. This recording paper 10 is sent to the transfer process by a paper feeding device 12 provided above the paper stacking box 11, following a path shown by a dotted line in the figure. still,
Reference numeral 13 indicates an auxiliary roller. The recording paper, which has been sent to the above-mentioned transfer process and has the image transferred thereto, then follows the path shown by the dashed-dotted line in the figure, and the image is fixed by the fixing device 14, after which the paper is transferred to the discharge roller 1.
5, it is discharged to the outside of the recording apparatus.

2 and 3 are diagrams showing how the photoreceptor 1 is installed in the above-mentioned recording apparatus. In particular, FIG. 2 shows an endless belt including the photoreceptor 1 (hereinafter referred to as photoreceptor 1). belt·
FIG. 3 shows unit holding means for holding the endless belt.

In the endless belt unit 16 shown in FIG. 2, feed rollers 2 and 3 for supporting and driving the photoreceptor 1 are supported at both ends of a support frame 17, respectively. In this case, the shaft end 3a of the feed roller 3 is inserted into a hole provided at one end of the support frame 17, so that the feed roller 3 is fixedly and rotatably supported by the support frame 17.
On the other hand, the other end of the support frame 17 is provided with an elongated hole 18 that is open on one side and extends toward the axis of the feed roller 3. It is supported by the support frame 17 by being inserted into the support frame 18 . The feed roller 2 is movable along the elongated hole 18 toward or away from other feed rollers 3, and a compression spring 19 is provided between the shaft end 2a of the roller 2 and the inner end of the elongated hole 18. As a result, the feed roller 2 applies appropriate tension to the photoreceptor 1. The photoreceptor 1 is driven in the direction of arrow A under this tension.

A unit holding means, designated by the reference numeral 20 in FIG. 3, is fixedly arranged within the recording device,
The tip of the holding means 20 forms a stepped portion 21, and a groove 22 having a width into which the shaft end 3a of the roller 3 can be inserted is provided at an inner position thereof. The distance between the step portion 21 and the groove 22 is approximately equal to the axial distance between the rollers 2 and 3 in the endless belt unit 16, and when the endless belt unit 16 is held by the unit holding means 20, the As shown, the shaft end 3a of the roller 3 is in the groove 22.
The shaft end 2a of the other roller 2 is inserted into the stepped portion 21.
will be placed on.

The conventional endless belt support device described above is configured so that the endless belt 16 can be removed from the unit holding means, that is, the main body of the recording device when the recording device is transported or stored in a warehouse. Since the photoreceptor 1 is always under tension even when the photoreceptor 1 is in the
This becomes more noticeable as the diameters of the rollers 2 and 3 become smaller. Furthermore, if the environmental conditions during transportation or storage are bad (for example, high temperature, low temperature, high humidity), elongation and deterioration phenomena occur in the photoreceptor 1 due to the above-mentioned tension.

In order to eliminate the above-mentioned drawbacks, it is conceivable to remove the photoreceptor 1 from the feed rollers 2 and 3 during transportation or storage, but in that case, a tension release mechanism should be provided in advance on the endless belt unit 16, or Alternatively, a special jig must be used to release the tension, and even if such means are used, the task of removing the photoreceptor 1 is extremely troublesome.

In this conventional device, as described above, it is difficult to remove the photoreceptor 1, and at the same time, it is also difficult to attach it, and therefore, replacing the photoreceptor 1 is also very troublesome.

The present invention aims to eliminate the above-mentioned drawbacks of conventional devices.

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

FIG. 4 is a side view showing the endless belt unit 26 according to the present invention. In the figure, the endless belt unit 26 has two support frames 27a and 27b, which support rollers 2 and 3, respectively, at one end thereof. In this case, the rollers 2 and 3 are mounted by inserting their shaft ends 2a and 3a into holes provided in the corresponding ends of the support frames 27a and 27b. In this case, at least the shaft end 3a protrudes toward the front of the support frame 27b. Two guide pins 2 are placed at appropriate intervals on the side surface of the support frame 27a.
8a and 28b are provided protrudingly, and one support frame 27
Elongated holes 29a, 29b having a width slightly wider than the diameter of the guide pins 28a, 28b are provided on the side surface of the guide pins 28a, 28b. The support frames 27a and 27b are
They are connected to each other by fitting the guide pin 28a into the elongated hole 29a and inserting the guide pin 28b into the elongated hole 29b.
They can mutually move linearly in the central axis direction of b.

In this embodiment, the long holes 29a and 29b are
The central axis B is set to coincide with a straight line connecting the axis 2c of the roller shaft 2a and the axis 3c of the roller shaft 3a. Therefore, as the support frames 27a and 27b move linearly, the rollers 2 and 3 can move linearly along the central axis B, and in this case, the axial distance between the rollers 2 and 3 is narrowed as a result. Or it can be expanded.

The figure shows a state when the axial distance between rollers 2 and 3 is the narrowest, and at this time no tension is applied to photoreceptor 1 stretched between rollers 2 and 3.

FIG. 5 is a side view showing the unit holding means 30 according to the present invention. This unit holding means 30 is fixedly disposed within the recording apparatus, and a groove 2 for fitting the roller shaft end 3a into the holding means 30 is provided.
2 is provided, which is the same as in the conventional example. The present unit holding means 30 differs from the conventional example in that a guide groove 3 is provided at an appropriate distance from the groove 22.
1 is provided. This guide groove 3
1 has an inclined part 31' on the open side, and the width of the closed part 31'' is slightly larger than the diameter of the guide pin 28a.
Regarding the distance between the upper end of the inclined part 31' and the groove 2
2 is smaller than the following distance, that is, the distance between the roller shaft end 3a and the guide pin 28a in the endless belt unit 26 in which the distance between the rollers 2 and 3 is at its narrowest as shown in FIG. It is set to be.

When a recording device in which the endless belt unit 26 and the unit holding means 30 are used is transported or stored in a warehouse, the unit 26 is separated from the holding means 30, so that the unit The axial distance between the rollers 2 and 3 at 26 is narrowed as shown in FIG. Therefore, the photoreceptor 1 is the roller 2
Since the photoreceptor 1 does not receive tension from the photoreceptor 1 and 3, the photoreceptor 1 does not curl, and does not elongate or deteriorate.

When the recording apparatus is operated, the endless belt unit 26 is first attached to the unit holding means 30.
The roller shaft end 3a and guide pin 28a of No. 6 are inserted into the groove 22 and guide groove 31 of the unit holding means 30, respectively. At this time, the guide pin 28a is pushed down along the inclined portion 31' of the guide groove 31, so that the pin 28a gradually moves to the left in FIG. 4. Since the guide pin 28a is fixed on the support frame 27a, when the pin 28a moves as described above, the support frame 27
Similarly, roller a moves to the left, and as a result, roller 2
The axial distance between the roller 3 and the roller 3 gradually increases. The distance between the roller shafts thus widened reaches its maximum when the guide pin 28a enters the closed part 31'' of the guide groove 31, and the installation is completed at this point.The state of the endless belt unit 26 at this time is shown in FIG. As shown by the broken line (the visible part is a solid line).

FIG. 6 shows the endless belt unit 26 in the state indicated by the broken line. In the figure, the guide pins 28a and 28b are in a state after they have moved to the left inside the elongated holes 29a and 29b, respectively, and the rollers 2 and 3, whose distance has been widened to the maximum by the movement, are able to move the photoreceptor 1 to the desired position. It gives tension.

Due to some reason during the operation of the recording device, the photoconductor 1
If it becomes necessary to replace guide pin 2,
8a and the roller shaft end 3a respectively into the guide groove 31.
Then, the endless belt unit 26 can be brought into the state shown in FIG. 4 by pulling it out from the groove 22. As described above, since no tension is generated in the photoreceptor 1 in this state, the photoreceptor 1 can be replaced very easily.

In the embodiment described above, the long holes 29a and 2
The center line B of 9b is configured to pass through the roller axes 2c and 3c, and therefore the rollers 2 and 3 move on a straight line connecting the axes 2c and 3c (hereinafter referred to as the inter-roller center line). It looks like this (Figure 4). However, as is clear from the above description, the purpose of the present invention is to narrow the distance between the roller axes when the endless belt unit is not installed, and therefore, the center lines of the elongated holes 29a and 29b are set as above. There is no requirement that it coincide with the center line between the rollers.

Further, guide pins 28a and 28b provided on the support frame 27a are connected to the support frame 27a.
a along the elongated holes 29a and 29b, but in particular, one guide pin 28a has the following function in addition to the above-mentioned function, that is, the attachment of the endless belt unit 26 to the unit holding means 30. It also functions as a guide member that expands the distance between the rollers by moving while being guided by the guide groove 31. Therefore, as a modified embodiment, there is no problem in sharing the functions by providing a guide member having the same shape as the guide pin 28a in addition to the guide pins 28a and 28b on the support frame 27a.

7 and 8 show other embodiments of the present invention. In FIG. 7, regarding support frames 37a and 37b that support rollers (not shown), a guide portion 38 is attached to the tip of one frame 37a.
A guide piece 39 is provided at the tip of the other frame 37b and has a width that allows it to be fitted into the guide part 38.
It is configured as. In addition, the support frame 37
As mentioned above, on the side surface of a, there is a guide member 4 guided by the guide groove 31 of the unit holding means 30.
0 is installed. FIG. 8 shows a plan view of FIG. 7, and the guide portion 38 is provided with a guide groove 38' having an appropriate width. Further, the thickness of the guide piece 39 of the support frame 37b is slightly thinner than the width of the guide groove 38'.
The guide member 40 projects from the inside of the support frame 37a to the outside through a hole provided in the frame 37a.

As the unit holding means for mounting the endless belt unit 36 having the above-mentioned structure, the unit holding means 30 in the previous embodiment can be applied as it is, and when it is mounted, the guide member 40
is inserted into the guide groove 31. The guide member 40 moves to the left in the figure by the inclined portion 31'' of the guide groove 31, and at the same time, the support frame 37a also moves linearly to the left along the guide piece 39, thereby increasing the distance between the roller axes. .

In the embodiments described above, the support frame of the endless belt unit carries the rollers in a stationary manner, but the following variations can also be used. FIG. 9 is a diagram showing a modification thereof, which is similar to the endless belt unit 2 shown in FIGS. 4 and 6.
6 is a modification of the support frame 27a in FIG. In this modification, the support frame 27'a
An elongated hole 41 having a width slightly larger than the diameter of the roller shaft 2a is provided on the roller 2 supporting end side, and the roller 2 can move along the elongated hole 41. Furthermore, a compression spring 42 is inserted into the elongated hole 41 between the roller shaft 2 a and the inner end of the elongated hole 41 . By adopting the above configuration, when the endless belt-shaped photoreceptor is stretched around the roller 2,
The photoreceptor can be subjected to precisely adjusted or suitably increased tension by the action of the compression spring 42. Incidentally, the reference numerals 28a and 28b are guide pins that have the same function as the guide pins 28a and 28b shown with the same reference numerals in FIG. 4 or 6.

In the above embodiment, the endless belt unit has two rollers, but the number of rollers is not limited to two, and more rollers can be used as needed. Can be attached. Similarly, the number of support frames within the unit is not limited to two.

As described above, according to the present invention, when an endless belt unit is removed from the main body of a recording device, etc., the distance between the axes of the rollers included in that unit is automatically narrowed, thereby releasing tension on the endless belt. be done. This release of tension prevents the endless belt from curling.
No elongation or deterioration occurs, and furthermore, the belt can be attached and detached from the unit very easily.

Furthermore, when the endless belt unit is attached to the main body of a recording device, etc., the unit moves according to the guide groove provided in the unit holding means, thereby automatically applying the necessary tension to the endless belt. It will be done.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an electrophotographic recording apparatus in which the present invention is implemented, Fig. 2 is a side view showing a conventional endless belt unit, Fig. 3 is a side view showing a conventional unit holding means, and Fig. 4 is a side view showing a conventional endless belt unit. 5 is a side view showing an embodiment of the endless belt unit according to the present invention, FIG. 5 is a side view showing an embodiment of the unit holding means according to the present invention, and FIG. 6 shows that the support frame 27a or 27b in FIG. FIG. 7 is a side view showing the main parts of another embodiment of the present invention; FIG. 8 is a plan view of FIG. 7;
FIG. 9 is a side view showing a modified embodiment of the support frame. 1... Endless belt (photoreceptor), 2, 3...
...Feed roller, 16, 26, 36... Endless belt unit, 20, 30... Unit holding means, 27a, 27b, 37a, 37b, 27'
a... Support frame, 28a, 28b... Guide pin, 29a, 29b... Long hole, 38... Guide portion, 39... Guide piece, 40... Guide member, 31
...Guide groove.

Claims (1)

[Scope of utility model registration request] An endless belt support device comprising an endless belt unit having an endless belt, a plurality of feed rollers for supporting and driving the endless belt, and a unit holding means for detachably holding the endless belt unit. The unit has a plurality of support frames carrying said feed rollers, guide means for guiding said support frames in linear movement relative to each other, and a guide member fixed on at least one support frame, while said The unit holding means has a guide groove for guiding the guide member, and when the endless belt unit is attached to the unit holding means, the feed roller moves according to the movement of the guide member guided by the guide groove. An endless belt support device characterized by widening the shaft spacing.