JPH04107259U - Image forming device - Google Patents

Abstract

(57) [Summary] [Purpose] For an image forming apparatus equipped with a process cartridge that houses an image forming means including an image carrier drum, it is possible to improve the workability of installation without causing problems in image quality. To provide an image forming apparatus equipped with a good connection means between a process cartridge and a drive shaft. [Structure] A pair of engaging and disengaging clutches is provided between a shaft 4 inside a photosensitive drum 1 of an image carrier and a drive shaft. That is, a coupling cylinder 6 that is axially slidable and biased by a spring is provided on a coupling shaft 5 that is integral with the photosensitive drum 1, and a pin 8 fixed across the diameter of the coupling cylinder 6 is provided. A groove 3a of a flange 3 integral with the photosensitive drum 1 is fitted into the groove 3a, and a slot 8 into which the pin 8 fits is provided in the drive shaft on the main body side of the image forming apparatus.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to image forming apparatuses that use an electrostatic transfer process, such as electrostatic copying machines and printers. It's about location.

0002

[Conventional technology]

Conventionally, in image forming apparatuses such as copying machines, the image carrier is driven in a circular manner. In the case of a cylindrical drum, one side of the drum is called a flange made of resin, etc. A gear is formed by forming a tooth surface on the outer periphery of a member that is fixed by press-fitting, gluing, etc. A common method is to configure a gear train through the gears of the flange to transmit the drive to the drum. It is. However, in this method of driving the drum by gear meshing, the gear tooth surface Constant velocity conduction cannot be obtained due to tooth surface wear due to slip components and gear accuracy. This caused the problem of uneven drum speed, which in turn resulted in blurred images. .

0003 In particular, as the period of use increases, this phenomenon increases, resulting in damage to the gear. This type of drum drive was the cause of attempts to prevent development into high-durability machines. or, A digital machine that reads the original image and raster scans it onto a drum using a laser beam. Compared to analog machines using slit exposure, the uneven speed of the drum affects the image. The sound was loud and had become a serious problem.

0004 To avoid the above problem, fix the drum on an axis passing through the center of the drum. There is a method of driving the shaft by directly transmitting power from the drive source using a belt. In other words In FIGS. 4 and 5, the drum 30 of the image carrier is so-called a cleaning device 31. It is made into a process cartridge.

[0005] In the figure, the drum 30 is attached to the front plate 11 and rear plate 12 of the process cartridge. It is rotatably supported by supports 37 and 38. With this configuration, the drum 30 and a magnet roller (not shown) for toner collection of the cleaning device 31. The cleaning function is improved by ensuring the parallelism between the two shafts and the respective axes. stop Then, the drive is transmitted to the drum 30 housed in the cartridge in the above-described manner. Therefore, conventionally, the driving force from the driving source was transmitted by the belt 32 and the pulley 33. A ram shaft 34 is provided on the main body side of the image forming apparatus, and the shaft 34 is extended in front of the front plate 11. A shaft flange fitted into one end of the drum 30 is mounted on this extended and protruding shaft 34. 35 through the machine screw 36 and screwed into the drum shaft 34 to fix the drive transmission. He was doing the same thing.

[0006]

[Problem that the idea aims to solve]

However, such a configuration has the following problems. In other words, machine screw 3 6, connect the female thread of the drum shaft 34 and the hole of the shaft flange 35 of the drum 30. It was necessary to manually rotate the drum 30 for alignment. And this hole When aligning, move the drum 30 in the forward and reverse directions and fix it in alignment with the hole position. Therefore, in order to rotate the drum 30 by this operation, the clip that is in contact with the drum 30 rotates. Contact traces of the urethane rubber blade of the cleaning device 31 remain on the drum 30. , there was a risk that this would be transferred to the transfer paper and lead to image defects.

[0007] Furthermore, it is difficult to rotate the drum 30 while manually moving it and fixing it to the drive shaft 34. It is time consuming and the workability is not good.

[0008] The present invention is based on a process cartridge containing an image forming means including an image bearing drum. In an image forming apparatus equipped with a An image showing a means of connecting the process cartridge and drive shaft for easy installation. The purpose is to provide a forming device.

[0009]

[Means to solve the problem]

The first idea of the present invention is to house an apparatus for performing an image forming process including a drum of an image bearing member. The process cartridge is installed in the image forming apparatus. The image forming apparatus main body includes a drive shaft that is connected to the drum of the image carrier when the image carrier is attached to the image forming apparatus. In the image forming apparatus, there is a removable mechanism between the internal shaft of the image bearing drum and the drive shaft. This image forming apparatus is characterized by being provided with a pair of interlocking clutches.

0010 The second idea of this invention is that the clutch pair is such that one clutch faces the other clutch. The image forming device according to the first invention, characterized in that it is elastically biased and can move in the axial direction. It is a place.

[0011]

【Example】

Hereinafter, an embodiment of the image forming apparatus according to the present invention will be described in detail based on FIGS. 1 to 3. Ru. Figure 1 shows the main cross section of the photosensitive drum as the drum of the image carrier according to the present invention, including its axis. In this figure, flanges 2 and 3 are fitted to both ends of the photosensitive drum 1. By connecting these flanges 2 and 3 with the hollow stay 4, the photosensitive The drum 1 and flanges 2 and 3 form an integral structure. The middle stay 4 has a plate-like A bracket 24 is fixed with machine screws 25. Bracket 24 has a cup A ring shaft 5 is fixed to the center of the photosensitive drum 1 by a machine screw 26. cup The diameter of the ring shaft 5 increases toward the right in the figure with a stepped portion 5a. Cuplin A coupling cylinder 6 is fitted to the coupling shaft 5 so as to be slidable in the axial direction, and The coupling shaft 5 has a coupling tube between the bracket 24 and the coupling tube 6 that urges the coupling tube. A compression spring 7 is inserted. The coupling cylinder 6 is moved to the right side in the figure by this spring 7. The coupling cylinder 6 is urged in the direction, and the coupling cylinder 6 is at a position where its step 6a abuts against the stepped portion 5a. Regulated. A pin 8 is press-fitted into the other end of the coupling cylinder 6. is always slidably fitted into the radial groove 3a of the flange 3. (Figure 2) A bearing 9 is press-fitted into the flange 3, and a support shaft 10 is attached to the flange 2. It is fixed coaxially with the center stay 4 in the center of the drum 1, and the process cartridge The photosensitive drum 1 housed in the frame has its support shaft 10 connected to the front plate 11 via a bearing 22. The flange 3 is rotatably supported by the bearing 9 fitting into the hole in the rear plate 12. It is configured to be supported.

0012 With the above configuration, the photosensitive drum 1 supported within the process cartridge frame is The process cartridge is held in a predetermined position by being attached to the main unit.

[0013] On the other hand, as shown in Figure 3, on the rear side of the device body, the rotational force from the drive source is transmitted by a belt. A drum drive shaft 13 to which a transmission pulley 20 is fixed is fixed to the rear side plate 14 of the main body. It is supported by support plates 15 and 16 via bearings 18 and 19 so as not to move in the axial direction. There is. A slot 13a is provided at the tip of the drum drive shaft 13. The width of 13a is large enough to fit into the pin 8 press-fitted into the coupling cylinder. ing. The inner diameter of the drum drive shaft 13 is a cup at the part where the slot 13a is provided. A circle that is larger than the ring cylinder 6 and has an outer diameter smaller than the inner diameter of the hollow shaft neck 3b of the flange 3. It has a cylindrical shape.

[0014] With the above configuration, when the process cartridge is installed in the main body of the apparatus, the photosensitive drum 1 When the side pin 8 does not fit into the slot 13a of the drum drive shaft 13, the cup The ring tube 6 resists the biasing force of the spring 7 and retreats to the left in FIG. . Thereafter, when the drum drive shaft 13 starts rotating with the start of the copying operation, the photosensitive drum When the slot 13a of the drum drive shaft 13 faces the pin 8 on the side of the drum 1, the spring 7 Due to the biasing force, the pin 8 fits into the slot 13a of the drum drive shaft 13, and this As a result, the rotation of the drum drive shaft 13 is sensed through the pin 8 and the flange 3 that fits into the pin 8. The drive is transmitted to the optical drum 1.

[0015] In the above configuration, the shape of the slot 13a of the photosensitive drum drive shaft 13 is, for example, as shown in the figure. As shown in 3, the pin 8 can be inserted more easily by adding a taper 21 to the inlet side. They may be fitted together.

[0016]

[Effect of the idea]

As explained above, one side is axially connected between the drum of the image carrier and the drum drive shaft. A pair of clutches that are movable and biased in the coupling direction are provided, so the drum of the image carrier can be Simply set the provided process cartridge in the designated position of the image forming device, and start operation. This eliminates the work required to connect the drum of the image carrier and its drive device. image By installing a clutch inside the drum of the carrier, you can save money by effectively utilizing space. This is a great advantage in reducing the size of the device by making it possible to change the pace of It is easy to drive the photosensitive drum without leaving any traces of the cleaning blade. This enables dynamic transmission and improves maintainability. Also, follow the drum shaft. There is no need to extend it to the front side of the drum as in the previous model, and it is possible to shorten it. It also has great advantages in terms of cost.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a photosensitive drum embodying the present invention.

FIG. 2 is a view of the flange of the photosensitive drum viewed from direction A in FIG. 1;

FIG. 3 is a longitudinal cross-sectional view showing a drive shaft that transmits drive to the photosensitive drum.

FIG. 4 is a perspective view of a process cartridge in which a cleaning device and a photosensitive drum are integrated, showing a part of the image forming apparatus.

FIG. 5 is a longitudinal sectional view showing a method of driving a photosensitive drum in a conventional device.

[Explanation of symbols]

3 Flange 3a Groove 5 Coupling shaft 6 Coupling tube 7 Compression spring 8 pin 13 Drum drive shaft 13a Suriwari

Claims (2)

[Scope of utility model registration request] 1. A process cartridge that houses a device for performing an image forming process, including a drum of an image bearing member, and a drive shaft that is connected to the drum of the image bearing member when the process cartridge is installed in the image forming apparatus. What is claimed is: 1. An image forming apparatus comprising: an image forming apparatus main body equipped with a pair of meshing clutches that can be engaged and disengaged between a shaft inside a drum of the image bearing member and a drive shaft. 2. The image forming apparatus according to claim 1, wherein the pair of clutches is movable in an axial direction, with one clutch resiliently biased toward the other clutch.