JPH05197222A - Process cartridge - Google Patents

Abstract

PURPOSE:To suppress the size of a process cartridge to the minimum by incorporating a gear train inside an electrostatic latent image carrier. CONSTITUTION:This process cartridge is a process cartridge of an electrophotographic copying device such as a copying machine or a laser printer obtained by arranging an electrostatic charger, a developer carrier, a cleaning member or the like around the electrostatic latent image carrier 2. When the gear trains 18, 20 and 24 are incorporated in the carrier 2 and the carrier 2 is driven by the electrophotographic copying device, the driving is accelerated or decelerated by the gear trains 18, 20 and 24. Then, a developing device is rotated by the accelerated or the decelerated driving. Besides, when the gear trains 18, 20 and 24 are incorporated in the carrier 2 and the developing device is driven by the electrophotographic copying device, the driving is accelerated or decelerated by the gear trains 18, 20 and 24 and the carrier 2 can be also rotated by the accelerated or the decelerated driving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge used in an electrophotographic apparatus such as a copying machine or a laser printer.

[0002]

2. Description of the Related Art Conventionally, as a developing method used in an electrophotographic apparatus, there is a developing method called a pseudo two-component method. A process cartridge using this method will be described with reference to FIG.

A charger 50, a developing sleeve 36, and a cleaning blade 52 are arranged along the rotation direction of the photosensitive drum 2 indicated by an arrow z, and a magnet roller 38 is included in the developing sleeve 36. Further, a layer thickness regulating blade 54 is provided on the developing sleeve 36. Development sleeve 36
The developer 58 filled in the toner case 56 containing the magnetic toner and the carrier is approximately 10 to 40 wt%, 60
The mixture is used in a weight ratio of ˜90 wt%.

In the process cartridge 32 having the above structure, the developing sleeve 36 is rotated in the direction of arrow x, and the magnet roller 38 therein is rotated in the direction of arrow y. Then, the toner and the carrier in the toner case 56 firstly come into contact with the developing sleeve 36 and the layer thickness regulating blade 5.
The thickness of the layer is regulated by passing through the gaps between Nos. 4 and 4, and as the developing sleeve 36 rotates, the layer goes toward the developing point facing the photosensitive drum 2. At this time, the magnet roller 38 in the developing sleeve 36 is rotating in the direction opposite to the developing sleeve 36. Therefore, focusing on a group of the developers 58 on the developing sleeve 36, the magnet roller 38 passes under the developer 58. The S pole and N pole of the magnet roller 38 have a considerable speed. The direction of the magnetic lines of force applied to the developer 58 is changed by the passage of the S pole and the N pole, and as a result, the spikes of the developer 58 move toward the developing point while rolling the surface of the developing sleeve 36 as shown in FIG.

As described above, the developer 58 passes between the layer thickness regulating blade 54 and the developing sleeve 36, and the developing sleeve 3
6 Roll to charge the surface. The charge obtained in the charging process increases as the rolling speed of the brush of the developer 58 increases, and thus increases as the relative speed between the developing sleeve 36 and the magnet roller 38 increases. Here, the rotation speed of the developing sleeve 36 is at most about three times the rotation speed of the photosensitive drum 2 in terms of the peripheral speed ratio, so the magnet roller 38 is rotated at a high speed.

In the developing sleeve and magnet roller both-rotation type process cartridge, the gear mounted on the flange of the photoconductor drum is first driven by the drive gear on the main body side of the electrophotographic apparatus to rotate the photoconductor drum. Further, the drive is transmitted from the gear of the photosensitive drum flange to the speed increasing gear train provided on the side plate in the process cartridge, and the gear train drives the developing sleeve to rotate the developing sleeve at a higher speed than the photosensitive drum. Let Further, this drive is transmitted to the magnet roller, and the magnet roller is rotated by the drive from the developing sleeve.

For example, in an electrophotographic apparatus of 12 ppm, the diameter of the photosensitive drum is 30 mm, the peripheral speed is 70 mm / sec (rotation speed 44.6 rpm), the diameter of the developing sleeve is 18 mm,
When the developing sleeve is rotated 3 times at the peripheral speed with respect to the photosensitive drum, the rotating speed of the developing sleeve is 222.8 rpm.
Therefore, a rotation speed about 5 times the rotation speed of the photosensitive drum is required, and a gear train of 2 to 3 stages is required. Furthermore, the magnet roller is rotated three times faster than the developing sleeve (about 660 rp).
Rotation in m) requires an additional 2-3 times the gear train.

Further, even when the magnet roller that rotates the fastest in the developing device is rotated by the drive on the main body side so that the developing sleeve and the photosensitive drum rotate sequentially at a low speed, the same number of gear trains as when increasing the speed is required. If these gear trains are provided on the side plate of the process cartridge, the gears are overlapped with each other and the process cartridge housing becomes large.

In order to avoid the use of the gear train, a process cartridge has been devised in which a motor is built in the process cartridge, the photosensitive drum is driven from the main body side, and the developing sleeve and the magnet roller are driven from the motor. There is.

[0010]

However, when the motor is built in the process cartridge, a space for the motor is required, and the outer shape of the process cartridge becomes large, or the toner storage space becomes small. there were. In addition, the surface of the developing sleeve is generally sandblasted to enhance the developer transporting ability, but if it is used for a long time, it may be stressed when the developer passes between the developing sleeve and the layer thickness regulating blade. There is a problem that the sandblasted surface is smoothed and the developer transporting power is lowered.

Since the smoothing of the blast surface (that is, the life of the developing device) occurs before the motor reaches the end of its life, the developing device is replaced by the smoothing of the blast surface so that even a motor that has not reached the end of its life is replaced. This is one of the causes of the high cost.

The present invention has been made to solve the above-mentioned problems, and does not make the process cartridge housing unnecessarily large by using a large number of gear trains and motors dedicated to driving the developing devices. The purpose is to avoid the high cost of using a motor.

[0013]

In order to achieve this object, a process cartridge of the present invention comprises a copying machine and a laser in which a charging device, a developer carrying member, a cleaning member and the like are arranged around an electrostatic latent image carrying member. A process cartridge for an electrophotographic apparatus such as a printer, wherein a gear train is built in the electrostatic latent image carrier, and when the electrophotographic device drives the electrostatic latent image carrier, driving is accelerated by the gear train. Alternatively, the developing device is rotated at a reduced speed, and the driving speed is increased or decreased.

A gear train is built in the electrostatic latent image carrier, and when the electrophotographic apparatus drives a developing device, the gear train speeds up or slows down the drive. The electrostatic latent image carrier can also be rotated.

[0015]

In the process cartridge of the present invention having the above structure, the gear on the main body side of the electrophotographic apparatus drives the electrostatic latent image carrier, and this drive is transmitted to the gear train in the electrostatic latent image carrier, The gear train speeds up or slows down the drive and transmits it to the developing device, and rotates the developer carrier or the magnet roller of the developing device. Alternatively, the gear on the main body side of the electrophotographic apparatus rotates, for example, a magnet roller in the developing device, and this drive is transmitted to the gear train in the electrostatic latent image carrier, and the gear train accelerates or decelerates the drive to cause electrostatic discharge. The latent image carrier is driven.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The structure of the gear train of this embodiment will be described with reference to FIG. 2 which is a sectional view of the photosensitive drum of FIG. 1 and a sectional view taken along the line AA in FIG.

A fixed gear 4 is attached to the left end surface and a rotary gear 6 is attached to the right end surface of the photosensitive drum 2 of FIG. 1 whose surface is coated with a photosensitive layer, and the fixed gear 4 is press-fitted into the photosensitive drum 2.
The rotary gear 6 is rotatably provided with respect to the photosensitive drum 2. A grounding metal 8 for fixing an electrical ground from the inner surface of the photosensitive drum 2 is fixed to the fixed gear 4 on the side where the photosensitive drum 2 is inserted. By pressing the fixed gear 4 into the photosensitive drum 2, A part of the grounding metal 8 is always in contact with the inner surface of the photosensitive drum 2 to obtain electrical continuity. A gear train for speeding up is incorporated inside the photosensitive drum 2 on the rotary gear 6 side, which will be described later.

Both the fixed gear 4 and the rotary gear 6 have convex portions 4a, 6
a, and by inserting the convex portions 4a and 6a into the holes provided in the casing 10 of the process cartridge,
The photosensitive drum 2 is rotatably supported with respect to the housing 10. Further, in order to rotate the photoconductor drum without eccentricity, the rotary shafts 12 and 14 are inserted into the center holes of the left and right gears 4 and 6 from the outside of the housing 10 and fixed integrally with the rotary shafts 12 and 14. The plate portions 12a and 14a are fixed to the housing 10 with bolts (not shown). Rotating shaft 1 on the fixed gear 4 side
Since it is necessary to ground the photosensitive drum 2 from 2,
A contact point 8a, which is partly a leaf spring, of the grounding metal 8 is in contact with the tip of the rotary shaft 12.

Next, the speed increasing gear train on the rotary gear 6 side will be described. A flange 16 is pressed into the end of the photosensitive drum 2 on the side of the rotary gear 6 in a tight fit. Therefore, the flange 16 is fixed to the photoconductor drum 2, and the relative movement of the two is not performed. A first gear 18 is provided inside the flange 16. This flange 16
A third gear 20 provided integrally with the rotary gear 6 reaches the inside of the photoconductor drum 2 through a hole provided in one end surface of the. A second gear 24 is provided between the third gear 20 and the first gear 18 so as to mesh with them, and a rotation shaft 26 of the second gear 24 is provided.
Is fixed to the plate 28. This plate 28
Since it is fixed to the rotating shaft 14 whose end is D-cut,
The plate 28 does not move relative to the housing 10 of the process cartridge, but is always stationary.

The operation of each component when the process cartridge 32 having the photosensitive drum 2 having the above-mentioned structure is used will be described.

As shown in FIG. 3, a process cartridge 32 including the above-mentioned photosensitive drum 2 is set in an electrophotographic apparatus 30 such as a known laser printer. FIGS. 4 and 5 show the state after setting, and FIG. 6 shows the relationship between the photosensitive drum 2 and the developing sleeve 36.

The photoconductor drum drive gear 34 in the electrophotographic apparatus 30 meshes with the fixed gear 4 to move the photoconductor drum 2 to the position shown in FIG.
2 and the direction of arrow a in FIG. 5, that is, the direction of arrow b in FIG. At this time, since the plate 28 does not move relative to the cartridge 32, when the photosensitive drum 2 rotates in the direction of arrow b, the first gear 18, the second gear 24, and the third gear 20 respectively move in the directions of arrow c, It rotates in the directions of d and e. When the third gear 20 rotates in the direction of arrow e, the rotary gear 6 formed integrally with the third gear rotates in the direction of arrow f. Since this rotation is accelerated by the gear train, it is faster than the rotation of the photosensitive drum 2. By driving the rotating gear 6, the developing sleeve 3
The magnet roller in 6 is rotated at high speed in the direction of arrow g in FIG.

As shown in FIG. 6, the developing sleeve drive gear 40 and the fixed gear 4 supported by the photosensitive drum 2 mesh with each other so that the photosensitive drum 2 is driven by the developing sleeve 36.
Is transmitted to the developing sleeve 36, the developing sleeve 36 rotates in the direction of arrow h in FIG. Therefore, the pseudo two-component development described in the conventional example (FIG. 7) is similarly performed by the developing device having the above-described configuration.

Since the speed-increasing gear train is built in the photosensitive drum 2 as described above, the process cartridge 32 can be made to have the minimum necessary size and the required number of rotations can be obtained.

In the above embodiment, the gear train has three stages from the first gear to the third gear, but if a further gear is arranged between the second and third gears, the finally obtained rotation direction is as described above. The opposite of. Therefore, when it is desired to reverse the rotation direction of the developing sleeve of the developing device to be driven or the magnet roller to that in the above example, this is preferable.

In the above embodiment, the electrophotographic apparatus 3 is used.
The photoconductor drum 2 was driven from 0 to increase the speed by the gear train in the photoconductor drum 2, but conversely, the magnet roller 3
8, or rotate the developing sleeve 36 by driving the main body,
The photoconductor drum 2 may be rotated by decelerating the rotation by the gear train.

[0028]

As is apparent from the above description, the process cartridge of the present invention has the gear train built in the electrostatic latent image carrier, so that the size of the process cartridge can be minimized. Can be suppressed.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a photosensitive drum.

FIG. 2 is a sectional view of the photosensitive drum taken along the line AA in FIG.

FIG. 3 is a diagram showing an operation of setting a process cartridge in an electrophotographic apparatus.

FIG. 4 is a diagram showing a state in which a process cartridge is set in the electrophotographic apparatus.

5 is a cross-sectional view showing details of the process cartridge in FIG.

FIG. 6 is a diagram showing a relationship between a photosensitive drum and a developing sleeve.

FIG. 7 is a cross-sectional view showing a conventional process cartridge.

FIG. 8 is a diagram showing the movement of the developer on the surface of the developing sleeve.

[Explanation of symbols]

 2 Photoreceptor Drum 18 1st Gear 20 3rd Gear 24 2nd Gear 30 Electrophotographic Device 32 Process Cartridge 36 Developing Sleeve 50 Charger 52 Cleaning Blade

Claims (2)

[Claims] 1. A process cartridge of an electrophotographic apparatus such as a copying machine or a laser printer in which a charging device, a developer carrying member, a cleaning member and the like are arranged around the electrostatic latent image bearing member. A gear train is built in, and when the electrophotographic apparatus drives the electrostatic latent image carrier, the drive is accelerated or decelerated by the gear train, and the developer is rotated by the accelerated or decelerated drive. A process cartridge characterized by being configured. 2. A process cartridge of an electrophotographic apparatus such as a copying machine or a laser printer in which a charging device, a developer carrying member, a cleaning member and the like are arranged around the electrostatic latent image bearing member. When the electrophotographic apparatus drives a developing device, the gear train is accelerated or decelerated by the gear train, and the electrostatic latent image carrier is rotated by the accelerated or decelerated drive. A process cartridge characterized by being configured.