JPH03145657A - Drive control method for image forming part - Google Patents

Abstract

PURPOSE:To surely carry out the driving of a photosensitive drum by reversely rotating a joint driving the photosensitive drum for a prescribed time after an image is completely formed and a cleaning blade is estranged. CONSTITUTION:An image forming part has a projecting part 317 and a recessed part 313, which fit each other, and the joint 310 which is energized by a elastic member 318 so as to maintain a fitting condition. Moreover, the image forming part is provided with the photosensitive drum 31 rotated and driven via the joint 310 and the cleaning blade 361 abutting on the photosensitive drum 31 so as to be estranged. After the image is completely formed, the cleaning blade 361 is estranged from the photosensitive drum 31, and then the joint 310 is reversely rotated for a prescribed time. Thus, the fitting condition of the project ing and recessed parts of the joint is loosen, and is surely maintained by the energization of the elastic member.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a drive control method for an image forming section in which a cleaning blade is in contact with a photoreceptor drum (prior art). As an image forming section of an image forming section of a computer or printer, an electrostatic latent image is formed on a photoreceptor drum, this electrostatic latent image is visualized into a toner image by a developing roller, and after being transferred to paper, There is a device that uses a cleaning blade to remove toner remaining on the photoreceptor drum.

In such an image forming section, in order to simplify the drive system and control circuit, the rotational drive of the photoreceptor drum and developing roller and the contact operation of the cleaning blade against the photoreceptor drum are controlled so that they start at the same time. has been done.

Incidentally, the photoreceptor drum is rotationally driven via a separable joint portion so that the drive system can be easily attached to the undercoat when the photoreceptor drum is attached or detached.

This joint portion 91, for example, as shown in FIG.
It connects the support shaft attached to the photosensitive drum 9o and the drum drive shaft 93 driven by the drive system of the main body of the image forming apparatus, and has a fitting recess 94a at the end of the support shaft. A flange 94 is provided, and a fitting protrusion 93a is provided at the end of the drum drive shaft 93, and is fitted into the fitting recess 94a so as to be integrally rotatable. The fitting recess 94a has a groove 9/lb formed facing the end opening, and the protrusion 9 of the fitting convex 93a is inserted into the groove 94b.
3b is inserted.

Further, the drum drive shaft 93 is formed to be movable in the axial direction and is biased by a spring in the direction of the photoreceptor drum 90 to maintain the fitted state between the fitting recess 94a and the fitting protrusion 93a. It looks like this (patent application 1986-3018)
63 Publication).

Since the flange 94 is made by forging,
Due to the draft angle of the mold, the fitting recess 94a is shaped like the groove 94.
The whole part including b has a tapered shape with a narrow end. A developing roller 95 for supplying toner is in contact with the photosensitive drum 90, and a cleaning blade 97 disposed in a cleaning device 96 for removing residual toner is removably pressed against the photosensitive drum 90.

(Problem to be Solved by the Invention) However, in the image forming section described in Section 2, the photosensitive drum 90 is driven by the joint section 91, and the image forming section is driven and controlled as described in Section 2. Therefore, when the photoreceptor drum 90 is rotated, there is a problem that the fitting convex portion 93a comes out of the fitting concave portion 94a.

That is, since the fitting recess 94a is tapered, the driving force of the photosensitive drum 90 by the drum drive shaft 93 is applied to the protrusion 9 pushed into the groove 94b, as shown in FIG.
Acts as force y to push out 3b. Therefore, the force y does not push out the protrusion 93b but pushes the fitting convex portion 93a into the fitting recess 94.
It is gradually pushed out from a.

Furthermore, to explain in detail, the cleaning blade 97
The developing roller 95 is pressed against the photosensitive drum 90 at the same time as the photosensitive drum 90 rotates.
Since the cleaning blade 97 is in constant contact with the photoreceptor drum 90, even if the cleaning blade 97 is separated from the photoreceptor drum lh 90, resistance is always applied to the photoreceptor drum lh 90. Therefore, the photosensitive drum 90 is not allowed to reverse, and the groove 93b and the protrusion 94b remain in pressure contact with each other, so that the fitting protrusion 93a pushed out toward the opening side
If the photosensitive drum 90 is repeatedly driven without being able to return to the inner part of the tapered fitting recess 94a, it will come out from the opening. Therefore, the photoreceptor drum 90 stops rotating, making it impossible to perform image formation.

To deal with this, it is possible to take measures to strengthen the spring force that urges the tram drive shaft 93 toward the photoreceptor drum 90. It takes extra load.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method for controlling the drive of an image forming section that can reliably drive a photoreceptor drum.

(Means for Solving the Problems) In order to achieve the above object, the method for controlling the drive of the image forming section of the present invention includes a projection and a recess that are fitted together so as to be rotatable together, and the projection and the recess are provided. One of the joints is biased toward the other side by an elastic member so as to maintain the fitted state, and the photoreceptor drum is rotationally driven through this joint 1 to 1, and the photoreceptor drum is In the method for driving and controlling an image forming section including a cleaning blade that is in contact with the photoreceptor drum so as to be releasable, after the image forming section finishes forming an image, the cleaning blade is separated from the photosensitive drum, and then the cleaning blade is moved away from the photosensitive drum for a predetermined period of time. It is characterized by reversing join 1~.

(Function) According to the above-described image forming unit drive control method, after the image formation is completed and the cleaning blade is separated, the joint that drives the photosensitive drum is rotated in the reverse direction for a predetermined period of time. This reverse rotation of the joint 1- loosens the fitted state between the convex portion and the recessed portion of the joint, and the fitted state of both can be reliably maintained by the biasing force of the elastic member.

(Example) Hereinafter, an example of the present invention will be described below with reference to the drawings. Note that this invention is not limited to this.

Here, FIG. 1 is a partially cutaway plan view showing a photosensitive drum drive mechanism and its control device in a copying machine as an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view of the same. A perspective view of the main parts, FIG. 3 is a schematic diagram of the internal structure of the copying machine,
FIG. 4 is a flowchart showing the control procedure of the copying machine.

First, an outline of a copying machine having an image forming section to which the present invention is applied will be explained with reference to FIGS. 2 and 3.

Mainly referring to FIG. 3, an optical system 2 for exposing and scanning a document is provided in the upper part of the inside of the copying machine main body 1, and an image forming part 3 for forming a copy image on paper P is provided below it. At the same time, a paper transport section 6 is provided from below the image forming section 3 toward the front end side (right side in the figure), and a toner image formed on the paper P is provided in the middle of the front end side of the paper transport section 6. A fixing means 7 is provided for fixing.

The optical system 2 includes a light emitter 21, a reflector 22, and a lens 23.
The document conveying means 8 can expose and scan the document traveling on the glass t1 to the contactor 1.

The image forming section 3 includes a charging charger 32, a developing device 33, a transfer charger 34, a separation charger 35, and a cleaning device 36 arranged in this order around a photosensitive drum 31 that rotates in the direction indicated by arrow X in the figure. After forming an electrostatic latent image by forming an original image on the photosensitive drum 31 that has been uniformly charged by the charging charger 32, the toner image is visualized by the developing device 33, and then the toner image is visualized by the transfer charger 34. The toner image can be transferred onto the paper P, and the remaining toner can be collected by the cleaning device 36.

The developing device 33 is composed of a toner hopper 331 that supplies toner, a supply container 332 that conveys the supplied toner to a developing roller 333, a developing roller 333 that attaches a predetermined amount of this toner to the photoreceptor drum 31, and the like. There is. 2. The developing roller 333 is driven to rotate at a peripheral speed faster than the photosensitive drum 31.
Toner can be supplied to the photoreceptor drum 3 without interruption, and the toner is in contact with the photoreceptor drum 31 in a state where the toner is sandwiched.

Further, as shown in FIG. 2, the cleaning device 36 includes a cleaning blade 361 whose tip can be pressed against the photoreceptor drum 31, and the cleaning plate 3
It is constituted by a drive section 362 and the like that presses or separates 61. This drive section 362 is connected to a control device 4 which will be described later.
Its operation is controlled by.

Further, a drive system 5 for rotating the photoreceptor drum 31 and the developing roller 333 is provided on the side (in a direction perpendicular to the paper surface of FIG. 3), and drives the photoreceptor drum 31 and the developing roller 333 at the same time. can do. Further, the drive system 5 can perform a predetermined timing drive operation by a control device 4 that performs operation control based on human power information from an operation unit 15 having a copy start button and a copy number setting key.

This copying machine has substantially the same structure as a known copying machine, and its unique feature compared to conventional copying machines lies in its control system. That is, the copying machine according to this embodiment includes a drive section 362 that separates the cleaning blade 361 from the photoreceptor drum 31 during non-copying operations of the copying machine, and a drive section 362 that separates the cleaning blade 361 from the photoreceptor drum 31 during non-copying operations. The blade 361 is configured to include a control means for controlling the rotation of the drive system 5 after the blade 361 is separated.

Each of the above means is described in advance in an operation program stored in a memory in the control device 4 that controls the copying machine, and is realized by executing this operation program.

Furthermore, the paper conveyance section 6 is configured from the innermost part of the paper insertion section 12 to the paper ejection side, and includes a paper feed roller 61, a paper guide member 62, a registration roller 63, and a conveyance roller 6.
4. Equipped with ejection roller 65, etc., and paper feed force roller l-
The paper P supplied from B or the paper insertion section 12 is guided to the image forming section 3 to transfer the toner image, and after being heated to zero and fixed by the fixing means 7, the paper P is discharged onto the holder 13. be able to.

The fixing means 7 has a heating roller 71 and a pressure heald 72 disposed facing each other. P can be held and conveyed to the paper ejection side.

The heating roller 71 is constantly rotated while being heated to a predetermined temperature by a heating means such as a heater provided inside.

Next, with reference also to FIG.
As shown in the figure, a fitting recess 3 is formed in a flange 312 connected to a support shaft at the end of the photoreceptor drum 31.
13, and a fitting convex portion 317 provided at the end of the drum drive shaft 316. The above fitting recess 31
3 is formed with an opening at the end and includes a groove portion 313a formed facing this opening. The fitting protrusion 317 includes a protrusion 317a that is inserted into the groove 313a of the fitting recess 313 when the end of the drum drive shaft 316 is inserted into the fitting recess 313.

The flange 312 of the photoreceptor drum 31 is manufactured by forging, and the fitting recess 312 is formed by the draft angle of the mold.
13 and the groove portion 313a have a tapered shape that becomes narrower toward the back.

Further, the drum drive shaft 316 is formed to be movable in the axial direction, and is biased toward the photosensitive drum 31 by a spring 318 as an elastic member pushed through the drum drive shaft 316. The fitting protrusion 317 is configured to fit securely into the fitting recess 313.

To explain the drive system 5 in detail, the apparatus of this embodiment includes a dedicated drive means 50 for rotating the drum drive shaft 316 in the reverse direction, in addition to the main motor 56 that rotates the photoreceptor drum 31 during the copying operation. The drive system 5 is configured including these.

The driving means 50 is constructed by connecting the photosensitive drum 31 and a low-speed motor 53 via gears 52, 54, 55, and a flange 51. Then, the control device 4 controls the flanch 51 and the low-speed motor 53, thereby causing the drum drive shaft 316 to rotate in the reverse direction.

The control device 4 includes a photoreceptor 1 ram 31 and a developing roller 3.
33, and after separating the cleaning blade 361 from the photoreceptor drum 31, the driving means 50 reversely rotates the drum drive shaft 316 for a predetermined period of time (0.5 seconds in this embodiment). can be done.

The control device 4 can simultaneously stop the photoreceptor drums 1 and 31 and the developing roller 333, and can also separate the cleaning blade 361 at the same timing.

In the copying machine having the above configuration, the operation procedure of the image forming section 3 when controlling the copying machine according to the above-mentioned operation program will be explained based on FIG.

In addition, in Fig. 4, SL, S2... are each operation step 3. bu.

First, the operator operates the copy start button (SL), and when the image forming section 3 performs and finishes the image forming operation (S2, S3), the control device 4 controls the photosensitive drum 3.
1 and the rotational drive of the developing roller 333 is stopped (
S4), the cleaning blade 361 is separated from the photoreceptor drum 31 (S5), and the above-mentioned parts are kept in that state until the next copying starts.

When the control device 4 determines that the cleaning blade 361 is separated from the photosensitive drum 31, the timer A is set in S6.

In this embodiment, the timer A is the drum drive shaft 3.
This is to reduce the operating time when rotating the 16 in the reverse direction. By controlling the low speed motor 53 of the drive system 5, the drum drive shaft 316 is rotated in the opposite direction to that during image formation (S7), and in S8 it is determined that the count value of the timer A has become equal to the set value. In this case, the low speed motor 53 is stopped and the drum drive shaft 316 is also stopped (S9). In S7, when the drum drive shaft 316 is rotated in the opposite direction to that during image formation, in other words, when the joint section 310 that drives the photoreceptor tram 31 is rotated in the opposite direction, the cleaning blade 361 comes into contact with the photoreceptor drum 31. Therefore, even if the groove portion 313a is formed in a tapered shape, the groove portion 313a of the fitting recess 313 of the joint portion 310 and the protrusion 317a of the fitting convex portion 317
The fitting state with the drum drive shaft 316 becomes loose, and the drum drive shaft 316 urged by the spring 318 can push the fitting protrusion 317 inward. Therefore, it is possible to reliably maintain the fitted state between the fitting recess 313 and the fitting protrusion 317.

Then, when it is determined that the copy button is turned on again by the operator, the timer A is initialized, and the control device 4 controls the drive unit 362 to bring the cleaning plate F361 into contact with the photoreceptor drum 31. . Thereafter, in S2, the copying machine performs a copying operation. When the copying operation is completed in S3, the controls 84 to 39 are repeated again.

Therefore, according to the apparatus of this embodiment, the driver 1. Even if the driving shaft 316 is reversely rotated and the cleaning blade 36 comes into contact with the joint portion 3IO, thereby increasing the driving resistance against the joint portion 3IO, the joint portion 310 is securely fitted, so that the drive of the photoreceptor drum 31 is cut off. It won't happen.

The operations of the other parts of the copying machine are the same as those conventionally known, and their explanations will be omitted.

Furthermore, the present invention is not limited to the embodiment described in -J2, and in the present embodiment, the clutch 51 and the low-speed motor 53 are omitted, and the drum drive shaft 316 is reversely rotated by the main motor 56. You may also do so. In this case S
7 constitutes a control means for controlling the drum drive shaft to rotate in reverse during non-copying operation of the copying machine.

Furthermore, various design changes can be made without changing the gist of the invention, such as using a joint with a rectangular cross section for driving the photosensitive drum.

Furthermore, the joint can also be provided with a fitting recess on the drive side and a fitting convex on the driven side.

Furthermore, it goes without saying that the copying machine according to this embodiment can be applied to an apparatus equipped with a belt-shaped photoconductor drum instead of the cylindrical photoconductor drum 31 as shown in the second embodiment. .

(Effects) As explained above, according to the image forming unit drive control method of the present invention, the cleaning blade is separated from the photoreceptor drum during non-copying operation, and the direction in which the drum drive shaft is driven during copying operation is different. It can be rotated in the opposite direction. As a result, the joint portion that drives the photoreceptor drum can be loosely fitted, and the elastic member can push into the convex portion or the concave portion to reliably maintain the fitted state of the joint. Therefore, it is possible to effectively prevent a problem in which the drive of the photoreceptor l° ram is cut off, and one of the causes of the inability to copy can be reliably eliminated.

7

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention, and Figure 1 is a partially cutaway plan view showing a photosensitive drum drive mechanism and its control device in an image forming apparatus according to the present invention. , FIG. 2 is a schematic perspective view of an image forming section implementing the image forming section drive control method of the present invention, FIG. 3 is a schematic configuration diagram showing the internal structure of a copying machine having the above image forming section, and FIG. 4 FIG. 5 is a schematic perspective view of a conventional image forming section, and FIG. 6 is a sectional view of a main part of the conventional image forming section. 3... Image forming section, 4... Photosensitive drum, 310 13... Fitting recess, 3 7... Fitting protrusion, 31... Spring (elastic member) Ning blade... Control device, 31...Joint part, 3 13a...Groove part, 31 7a...Protrusion, 318. 36]...Crim;

Claims (1)

[Claims] (1) A joint that has a convex portion and a concave portion that fit together so as to rotate together, and one of the convex portion and the concave portion is urged toward the other side by an elastic member so as to maintain the fitted state. In a method for driving and controlling an image forming unit including a photoreceptor drum rotationally driven via the joint, and a cleaning blade that is in releasably abutted contact with the photoreceptor drum, an image in the image forming unit is provided. A method for controlling drive of an image forming section, comprising separating the cleaning blade from the photoreceptor drum after completion of formation, and then reversing the joint for a predetermined period of time.