JPH10228221A - Recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording device capable of suppressing irregularities in rotating a photoreceptor drum as much as possible and recording an image of high image quality. SOLUTION: As for the recording device for rotary-driving the photoreceptor drum 18 so as to record the image, the device is provided with a male screw part 13 and a female screw part 16 (fastening means) for attaching/detaching the photoreceptor drum 18 by the rotating force of an ultrasonic motor (photoreceptor drum driving motor) 1 and tapered parts (centering means) 14 and 17 for making the center axis of the rotary shaft 12 of the ultrasonic motor 1 nearly align with the center axis of the photoreceptor drum 18. Thus, at the time of loading the photoreceptor drum 18, the connection of the photoreceptor drum 18 and the rotary shaft 12 of the ultrasonic motor 1 is accomplished without causing a backlash, and also, the rotary shaft 12 of the ultrasonic motor 1 is made to nearly align with the center axis of the photoreceptor dram 18 through the tapered parts 14 and 17, then, the rotational accuracy of the photoreceptor drum is enhanced, and the irregularities in rotating the photoreceptor drum are suppressed as little as possible, then, the image of high image quality is recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for performing recording by rotating a photosensitive drum.

[0002]

2. Description of the Related Art In a recording apparatus having a photosensitive drum, the photosensitive drum has conventionally been manually attached and detached. Therefore, in order to easily attach and detach the photosensitive drum, it is necessary to secure a large play between the photosensitive drum drive shaft and the photosensitive drum in the recording apparatus.

[0003]

However, if a large play is provided between the photosensitive drum drive shaft and the photosensitive drum as in the prior art, the photosensitive drum may have uneven rotation. There is a problem that hinders high image quality.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a recording apparatus capable of performing high-quality image recording while suppressing rotation unevenness of a photosensitive drum. .

[0005]

According to a first aspect of the present invention, there is provided a recording apparatus for performing recording by rotating a photosensitive drum, the photosensitive drum being driven by a rotating force of a photosensitive drum driving motor. And a centering means for making the center axis of the rotating shaft of the photosensitive drum drive motor substantially coincide with the center axis of the photosensitive drum.

According to a second aspect of the present invention, in the first aspect of the invention, the centering means includes a tapered portion provided on a rotating shaft of a photosensitive drum driving motor, and a photosensitive drum fitted to the tapered portion. And a tapered portion provided in the second portion.

According to a third aspect of the present invention, in the first or second aspect, when the photosensitive drum is mounted, the photosensitive drum driving motor rotates in the same direction as that during image recording.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, when the photosensitive drum is detached, the motor for driving the photosensitive drum rotates in a direction opposite to that in image recording.

According to a fifth aspect of the present invention, in the first to third or fourth aspects of the invention, the photosensitive drum driving motor is an ultrasonic motor.

According to a sixth aspect of the present invention, in the first to third or fourth aspects of the present invention, the photosensitive drum driving motor is a stepping motor.

According to a seventh aspect of the present invention, in the first to fifth or sixth aspects, the same number of photosensitive drums and photosensitive drum driving motors are provided.

According to an eighth aspect of the present invention, in the first to sixth or seventh aspects, a plurality of photosensitive drums are provided.

Therefore, according to the present invention, when the photosensitive drum is mounted, the rotation of the photosensitive drum driving motor allows the photosensitive drum and the rotating shaft of the photosensitive drum driving motor to be connected without looseness, and the photosensitive drum is aligned by the centering means. Since the rotation axis of the drive motor and the center axis of the photosensitive drum can be made substantially coincident with each other, the rotation accuracy of the photosensitive drum can be increased, the rotation unevenness can be suppressed, and high-quality image recording can be performed. .

[0014]

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

FIGS. 1 to 3 are sectional views showing the procedure of attaching the ultrasonic motor shaft and the photosensitive drum unit of the recording apparatus according to the present invention in the order of the steps. FIG. 1 shows a state before the photosensitive drum unit is attached to the ultrasonic motor. Diagram showing the state, FIG.
FIG. 3 is a view showing a state where the photosensitive drum unit is being attached to the ultrasonic motor, and FIG. 3 is a view showing a state where the photosensitive drum unit is attached and fixed to the ultrasonic motor.

The ultrasonic motor 1 includes a flange 11 and a side plate 2.
It is attached by fixing it with screws etc.
A part of the rotating shaft 12 of the ultrasonic motor 1 has a male screw 1
3 is formed, and a tapered portion 14 is formed at the tip of the rotating shaft 12.

On the other hand, the photosensitive drum unit 3 is constituted by fitting flanges 15 and 19 at both ends of a photosensitive drum 18 having a photosensitive layer formed on the outer peripheral surface of a relatively thin metal cylinder. The female shaft 16 to which the male screw 13 formed on the rotary shaft 12 of the ultrasonic motor 1 is screwed is mounted on the flange 15 on the side where the rotary shaft 1 is received.
A tapered portion 17 to which the tapered portion 14 formed at the tip of the second 2 is fitted is formed.

When mounting the photosensitive drum unit 3, the photosensitive drum unit 3 is inserted into the ultrasonic motor 1 in the direction of the arrow in FIG. The rotary shaft 12 of the ultrasonic motor 1 is rotationally driven in the same direction as the rotation direction at the time of recording, as shown in FIG. 2, in a state where is fitted into the male screw portion 13 of the rotary shaft 12 of the ultrasonic motor 1. Then, as shown in FIG. 3, the male screw portion 13 formed on the rotating shaft 12 of the ultrasonic motor 1 is screwed into the female screw portion 16 formed on the flange 15 of the photosensitive drum 18 and the ultrasonic motor 1 The tapered portion 14 of the rotating shaft 12 fits into the tapered portion 17 formed on the flange 15 of the photosensitive drum 18, and the photosensitive drum unit 3 is axially positioned with respect to the ultrasonic motor 1 and the rotation center axis is positioned.

The positioning by the tapered portions 14 and 17 allows the rotation center axes of the photosensitive drum unit 3 and the ultrasonic motor 1 to coincide with each other with high accuracy, and the reproducibility thereof is good. As a result, the photosensitive drum 18 can be accurately positioned. Can be rotated. Although the photosensitive drum unit 3 may be slightly displaced in the direction of the arrow due to a manufacturing error of the tapered portions 14 and 17, the width of the optical writing to the photosensitive drum 18 is generally equal to the width of the photosensitive layer of the photosensitive drum 18. This is not a problem because it is relatively small.

On the other hand, when the photosensitive drum unit 3 is detached, the rotating shaft 12 of the ultrasonic motor 1 is driven to rotate in the direction opposite to the recording direction, so that the male screw portion 13 of the rotating shaft 12 and the flange 15 of the photosensitive drum 18 are rotated. Of the photosensitive drum unit 3 by releasing the engagement between the tapered portion 14 of the rotating shaft 12 and the tapered portion 17 formed on the flange 15 of the photosensitive drum 18 while releasing the screw engagement with the female screw portion 16 of the photosensitive drum 18. It is disconnected from the motor 1.

Here, a multicolor recording apparatus as an example of the recording apparatus according to the present invention will be described with reference to FIGS.
FIG. 4 is a cross-sectional view of a main part of the multicolor recording apparatus, and FIG. 5 is a plan view of the main part of the multicolor recording apparatus.

As shown in FIG. 4, the transfer paper P is conveyed in the direction of the arrow, and the transfer belt 3 wound around rollers 31 and 32.
3 is guided by the roller 30 onto the transfer belt 3
3 is transported to a black transfer position set so as to be held between the photosensitive drum 103 and the transfer blade 127. At this time, a desired black toner image is formed on the photosensitive drum 103 through an electrophotographic process by the charging means 124, the exposure means 120, and the developing sleeve 123 of the developing means 122, which are arranged around the photosensitive drum 103. 127, the image is satisfactorily transferred to the transfer paper P.

The transfer paper P to which the black toner image has been transferred as described above is conveyed to a cyan transfer position set so as to be held between the photosensitive drum 203 and the transfer blade 227 as the next recording means. You. At this time, the photosensitive drum 20
3 includes charging means 224 and exposure means 22 disposed around
A desired cyan toner image is formed through an electrophotographic process using the developing sleeve 223 of the developing means 222 and the developing means 222, and the cyan toner image is satisfactorily transferred to the transfer paper P by the action of the transfer blade 227.

Thereafter, the transfer paper P is conveyed to a magenta transfer position set so as to be held between the photosensitive drum 303 and the transfer blade 327 as the next recording means. At this time, a desired magenta toner image is formed on the photosensitive drum 303 through an electrophotographic process by a charging unit 324, an exposing unit 320, and a developing sleeve 323 of a developing unit 322. The magenta image is formed by a transfer blade. By the action of 327, the image is satisfactorily transferred to the transfer paper P.

Further, the transfer paper P is conveyed to a yellow transfer position set so as to be held between the photosensitive drum 403 and the transfer blade 427 as the next recording means. At this time, the photosensitive drum 403 has charging means 4
24, a desired yellow toner image is formed through an electrophotographic process by the exposure means 420 and the developing sleeve 423 of the developing means 422, and this yellow toner image is satisfactorily transferred to the transfer paper P by the action of the transfer blade 427.

As shown in FIG. 5, the photosensitive drums 103, 203, 303, and 403 are attached to the side plate 2 by the same structure as described above, and these are rotated by the ultrasonic motors 101, 201, 301, and 401. Well installed on the shaft. In FIG. 5, 115, 215,
Reference numerals 315, 415, 119, 219, 319, and 419 denote flanges fitted to both ends of the photosensitive drums 101, 201, 301, and 401, respectively.

As described above, each photosensitive drum 10
3, 203, 303, 403 are ultrasonic motors 101,
The ultrasonic motors 101, 201, and 30 are centered with high precision with respect to the rotation axes of the motors 01, 301, and 401.
The photosensitive drums 103, 203, 303, and 403 are simply set by setting the mounting positions of the photosensitive drums 1 and 401 to the side plate 2 with high accuracy.
Is accurately positioned, and the registration of the image between the recording means is performed satisfactorily.

The ultrasonic motors 101, 201, 30
The relative positioning accuracy of the ultrasonic motors 101, 201, 301, and 401 is further improved by adjusting and assembling the photosensitive drums 1 and 401 on the side plate 2.
The registration accuracy can be improved by improving the relative positional accuracy of the rotation axes of 3, 203, 303, and 403.

The recording paper P on which multicolor recording has been performed through the above process is fed to fixing units 34 and 35 shown in FIG. Images can be obtained.

In a recording apparatus using a single photosensitive drum, the same effect can be obtained by using a single recording means.

Next, the rotation control of the ultrasonic motor in the recording apparatus according to the present invention will be described with reference to FIG. FIG. 6 is a block diagram showing the configuration of the rotation control system of the ultrasonic motor.

The ultrasonic motor 1 is driven by the driver 50 to rotate the photosensitive drum unit 3. The rotation axis of the ultrasonic motor 1 or the rotation amount of the photosensitive drum unit 3 is detected by detecting a signal on an encoder scale (not shown) provided in the encoder 52 by an encoder detection unit (not shown). It is counted by a counter (not shown) and taken into the controller 51. Then, the controller 51 controls the driver 50 so that the count value of the signal amount becomes equal to the set value, and the driver 50 drives the ultrasonic motor 1 to rotate the photosensitive drum unit 3 at the set speed.

Similarly, the absolute position of the photosensitive drum unit 3 during rotation is counted by the counter by detecting the signal on the encoder scale in the encoder 52 by the encoder detection unit, and the count value is taken into the controller 50.

The encoder scale is an ultrasonic motor 1
May be provided directly on the rotating shaft of the photosensitive drum unit 3, or may be provided on the photosensitive drum unit 3. Also, encoder 5
As 2, any type such as an optical type and a magnetic type can be used.

As described above, in this embodiment, when the photosensitive drum unit 3 is mounted, the rotation of the ultrasonic motor 1 allows the photosensitive drum 18 to be connected to the drive shaft 12 of the ultrasonic motor 1 without play. Drive shaft 12 of ultrasonic motor 1 and flange 1 of photosensitive drum unit 3
5, the photosensitive drum unit 3
Therefore, the cause of the deterioration of the rotation accuracy of the photosensitive drum 18 is removed, the rotation unevenness of the photosensitive drum 18 is reduced, and high-quality image recording can be performed.

In the above embodiment, an ultrasonic motor is used as the photosensitive drum driving motor. However, a stepping motor may be used, and other motors may be used as long as they can rotate in both forward and reverse directions. You may use it. or,
Although a screw is used at the joint between the photosensitive drum and the rotating shaft of the photosensitive drum drive motor, a member such as bayonet that can be favorably joined by using a rotating force may be used.

[0037]

As is apparent from the above description, according to the present invention, when the photosensitive drum is mounted, the rotation of the photosensitive drum driving motor prevents the coupling between the photosensitive drum and the rotating shaft of the photosensitive drum driving motor. In addition, the rotation axis of the photosensitive drum driving motor and the center axis of the photosensitive drum can be made to substantially coincide with each other by the centering means, so that the rotation accuracy of the photosensitive drum can be increased and the rotation unevenness can be suppressed to be small. The effect that high-quality image recording can be performed is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state before a photosensitive drum unit is attached to an ultrasonic motor in a recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which a photosensitive drum unit is being attached to an ultrasonic motor in the recording apparatus according to the present invention.

FIG. 3 is a cross-sectional view showing a state where a photosensitive drum unit is attached to and fixed to an ultrasonic motor in the recording apparatus according to the present invention.

FIG. 4 is a sectional view of a main part of the multicolor recording apparatus according to the present invention.

FIG. 5 is a plan view of a main part of the multicolor recording apparatus according to the present invention.

FIG. 6 is a block diagram showing a configuration of a rotation control system of an ultrasonic motor of the recording apparatus according to the present invention.

[Explanation of symbols]

1, 101, 201, 301, 401 Ultrasonic motor (motor for driving photosensitive drum) 3, 103, 203, 303, 403 Photosensitive drum unit (photosensitive drum) 12 Rotary shaft 13 Male screw part (fastening means) 14, 17 Tapered part ( Centering means) 16 Female thread (fastening means) 18 Photosensitive drum 50 Driver 51 Controller 52 Encoder

Claims (8)

[Claims] 1. A recording device for recording by rotating a photosensitive drum, comprising: fastening means for detachably attaching a photosensitive drum by a rotating force of a photosensitive drum driving motor; and a central axis of a rotating shaft of the photosensitive drum driving motor. And a centering means for making the center axis of the photosensitive drum substantially coincide with the center axis of the photosensitive drum. 2. The centering means comprises a tapered portion provided on a rotation shaft of a photosensitive drum drive motor, and a tapered portion provided on a photosensitive drum fitted to the tapered portion. 2. The recording apparatus according to claim 1, wherein: 3. The recording apparatus according to claim 1, wherein when the photosensitive drum is mounted, the photosensitive drum driving motor rotates in the same direction as when recording an image. 4. The recording apparatus according to claim 1, wherein when the photosensitive drum is removed, the photosensitive drum driving motor rotates in a direction opposite to the direction in which the image is recorded. 5. The recording apparatus according to claim 1, wherein the photosensitive drum driving motor is an ultrasonic motor. 6. The recording apparatus according to claim 1, wherein the photosensitive drum driving motor is a stepping motor. 7. The recording apparatus according to claim 1, wherein the same number of photosensitive drums and photosensitive drum driving motors are provided. 8. The recording apparatus according to claim 6, wherein a plurality of photosensitive drums are provided.