JPS63169669A - Rotation control method for photosensitive body and transfer body - Google Patents

Abstract

PURPOSE:To prevent a photosensitive body and a transfer body from being recessed and flawed by preventing the seam parts of the photosensitive body and transfer body from stopping at their abutting parts by controlling the rotations of the photosensitive body and transfer parts which have the seam part according to a seam detection result. CONSTITUTION:A CPU 5 judges the rotation state of the photosensitive body 1 and transfer body 2 from the contents of a ROM 51 according to the output signals of sensors 12 and 22 which detect the seams 11 and 21, and outputs on-off signals to drivers 55 and 56 for motors 13 and 23. When the seam 11 passes the position of the sensor 12, a timer starts and the motor 13 turns off in response to the time-up state of the timer, so that the photosensitive body 1 stops rotating. Further, the timer clocks the off timing of the motor 13 and this clocking time is set to the time when the seam 11 does not abut on a contact part 13. Therefore, the seam 11 never stops as the contact part 3 at the time of the rotation stop of the photosensitive body 1. Similarly, the seam 21 is never positioned at the contact part 3 at the time of the rotation stop of the transfer body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION +a) Industrial Application Field The present invention relates to a method for controlling the rotation of a photoreceptor and a transfer member in an image forming apparatus that transfers toner on the surface of the photoreceptor to a transfer member that is in contact with the photoreceptor.

(b) Prior Art Some image forming apparatuses using electrophotography transfer toner on the surface of a photoreceptor to a transfer member, and then transfer the toner from the transfer member to paper. A photoreceptor like this.

The transfer body is generally formed in the shape of a drum or belt, and some of them have seams.

The joining of the photoreceptor and transfer member is shown in Figure 5 <A) and (B).
), this is done by tape adhesion and fusing. When tape adhesion is used as shown in FIG. 5 (A>), the thickness of the tape B adhered to the surface of the photoreceptor and transfer member A varies depending on the thickness of the photoreceptor.

A step is formed on the surface of the transfer body A. In addition, as shown in FIG. 5(B), in the case of fusion bonding, the photoreceptor, the transfer body A
The surface becomes uneven due to the fused portion C. The area including the tape B and the fused part C, which is approximately several inches long in front and back (with respect to the rotational direction of the photoconductor and transfer body), is a non-image forming area.
Images are formed only outside this area.

(C1 Problem to be Solved by the Invention As mentioned above, when a drum-shaped or belt-shaped photoconductor or transfer body has a seam, when the rotation of the photoconductor or transfer body stops, one seam is connected to the other. There were cases where the 6th part stopped and was left in contact with a part other than the seam.
As shown in the figure, if the joint 21 of the transfer body 2 is left in contact with the image forming area a of the photoreceptor 1, the image forming area a will be affected by the unevenness of the tape at the seam 21 or the fused part. It could cause dents or scratches. It is undesirable for the photoreceptor 1 to be dented or damaged, as this will lead to deterioration in the quality of the image formed. Conversely, if the joint of the photoreceptor is left in contact with the image forming area of the transfer member, the image forming area of the transfer member will be dented and scratched, causing deterioration of image quality. .

In view of the above, the present invention provides a photoreceptor that prevents dents and scratches on the photoreceptor and transfer member by preventing the joint between the photoreceptor and the transfer member from stopping at the abutment area between the photoreceptor and the transfer member. The object of the present invention is to provide a method for controlling the rotation of a transfer body.

(d) Means for Solving the Problems The present invention provides a method for controlling the rotation of a photoreceptor or a transfer body that is independently rotationally controlled and has a seam on at least one of them, the seam being detected by a seam detection means. At the same time, based on the detection result by the seam detection means, the rotation of the photoreceptor and/or transfer body with a seam is controlled so that the seam is not located in the mutual contact area when the rotation of the photoreceptor and transfer body is stopped. It is characterized by control.

(G) Function In the method for controlling the rotation of a photoconductor and transfer body of this invention,
The rotation of the photoreceptor and the transfer member is independently controlled, and during the rotation, the position of the seam formed on the photoreceptor and/or the transfer member is detected by a seam detection means. Depending on the detection result, that is, the joint position, the timing of when the photoreceptor and/or transfer member stops rotating is controlled, and the rotation is stopped so that the joint is not located at the abutting portion between the photoreceptor and the transfer member.

ff) Embodiment FIG. 3 is a side view showing the structure of a photoreceptor and a transfer body of an image forming apparatus according to an embodiment of the present invention. In the figure, parts that are the same as those of the apparatus in FIG. 6 are designated by the same numbers.

The photoreceptor 1 has a bell shape stretched between a pair of rollers, and a seam 11 is formed by tape or fusion. The transfer body 2 is also in the form of a belt stretched between rollers.
A seam 21 is formed.

The photoreceptor 1 and the transfer member 2 are in contact with each other in a substantially rolled T-shape.
At the contact portion 3, the toner on the surface of the photoreceptor 1 is transferred to the transfer member 2 by a transfer charger 4. The photoreceptor 1 and the transfer member 2 have separate motors 13 and 23, respectively, and are rotatable in the directions of arrows A and B in the figure. The motors 13 and 23 are driven and stopped by drive signals from the CPU, which will be described later.

During the image forming process, the photoreceptor 1 and the transfer member 2 rotate synchronously at the same circumferential speed. Note that, at the start of the image forming process, the photoreceptor 1. Notches (not shown) are formed at the ends of the seams 11 and 21 to be synchronized after increasing and decreasing the rotational speed of the transfer body 2, and the photoconductor 1 and the transfer body are arranged so as to face these notches. 2 is a transmission type optical sensor 1
2 and 22 are arranged. The optical sensors 12 and 22 respectively detect the joints (notches) and turn on when the joints 11 and 21 face the optical sensors 12 and 22 due to rotation of the photoreceptor 1 and the transfer body 2, respectively.

FIG. 2 is a block diagram of a control section for the photoreceptor and transfer member.

The entire control is performed by the CPU 5, and its program is stored in the ROM 51 in advance. When executing a program, the RAM 52 is used as a working area. An optical sensor 12 that detects the seam 11 of the photoreceptor. An on signal from the optical sensor 22 that detects the seam 21 of the transfer body is input to the CPU 5 via the l1053. Based on this ON signal, the CPU 5 can know the rotational states of the photoreceptor 1 and the transfer member 2 by a program stored in the ROM 51.

The CPU 5 also controls the photoreceptor motor 1 via l1054.
3. Turn on the driver 55 and 56 of the transfer body motor 23,
Outputs an off signal. CPU5 has drivers 55 and 5
6, an on signal is outputted at the start of the image forming process, and an off signal is outputted based on the input signals from the optical sensors 12 and 13 at the end of the process.

FIGS. 1A and 1B are flowcharts showing the operation of the motor during image formation. As mentioned above, the photoreceptor 1. The motors 13 and 23 of the transfer body 2 are driven individually. Therefore, FIG. 1A shows the operation of the photoreceptor motor 13, and FIG. 1B shows the operation of the transfer member motor 23.

First, in step nl (hereinafter referred to as "step ni"), which describes the operation of the key 13 of the photoreceptor, when an image forming start switch (not shown) is turned on, the image forming process starts, and n2 At step n3, the photoreceptor motor 13 is turned on and the photoreceptor 1 rotates in the direction of arrow A in FIG. 1, and an image forming process is performed at step n3. That is, a toner image is formed on the surface of the photoreceptor 1, and the toner image is transferred to the transfer member 2 and further to paper to form an image. When the image forming process ends at n4, n5
Then, the on/off state of the optical sensor 12 of the photoreceptor is determined. When the joint 11 of the photoreceptor passes through the location of the optical sensor 12, the optical sensor 12 is turned on and its signal is input.
Proceeding to n6, timer Tl is started. And nl
When the timer Tl times up, the process advances to n8, the motor 13 is turned off and the rotation of the photoreceptor 1 is stopped, and the process returns to n1 to wait for the start of the image forming process.

The timer Tl measures the off timing of the motor 13, and the time measured by the timer T1 is the time taken for the seam 11 to reach the contact portion 3 after passing through the location where the optical sensor 12 is disposed, or , the time from passing through the contact portion to reaching the installation position of the optical sensor 12, that is, the time during which the seam 11 does not come into contact with the contact portion 3 is set.

Therefore, when the photoconductor l stops rotating, the joint 1 of the photoconductor
1 is no longer located at the contact portion 3.

Further, the motor 23 of the transfer body in FIG. 2B operates in the same manner, and when image formation starts at nl, the motor 23 is turned on at n9 and the transfer body 2 rotates in the direction of arrow B, and n3
-"When the image forming process is completed at n4, the on/off state of the photosensor 22 of the transfer body is determined at nlO. When the seam 21 of the transfer body passes through the placement position of the photosensor 22, the photosensor 22 is turned on. The signal is input, advances to nil, and starts timer T2. Then, when timer T2 times up at n12, advances to n13, the motor 23 is turned off, rotation of the transfer body 2 is stopped, and returns to nl to form an image. Wait for the process to start.

The timer T2 is for measuring the off timing of the motor 23, and the time measured by the timer T2 is such that the seam 21, which has passed through the position where the optical sensor 22 is disposed, reaches the contact portion 3.
The time required for the seam 21 to reach the contact portion 3 or the time required for the seam 21 to pass through the contact portion and reach the installation position of the optical sensor 22 is set, that is, the time for the seam 21 to not contact the contact portion 3 .

Therefore, when the transfer body 2 stops rotating, the seam 2 of the transfer body
1 is no longer located at the contact portion 3.

FIG. 4 shows another embodiment in which the transfer body 2 is formed into a belt shape having a seam 21 as in the above embodiment, and the photoreceptor 6 is formed into a seamless drum shape. As shown in the figure, in the transfer body 1 in this case, the motor 23 that rotates the transfer body 2 may be turned off after a predetermined period of time has passed after the optical sensor 22 detects the seam 21, as in the above embodiment. .

In this embodiment, the motor is turned off when the rotation of the photoreceptor and transfer body is stopped, but a clutch may be provided to switch the motor.

(Effects of the Invention According to the method for controlling the rotation of a photoconductor or transfer body of the present invention, when the rotation of the photoconductor or transfer body is stopped, the seam of the photoconductor or transfer body is determined based on the detection result of the seam detection means. Since the photoconductor and transfer body are stopped in such a way that they are not in contact with each other, even if left in that state, the seams will not cause dents or scratches on the photoconductor or transfer body, and the quality of the formed image will deteriorate. It is possible to prevent this from happening.

[Brief explanation of the drawing]

1A and 1B are flowcharts showing the operation of the motors of the photoconductor and transfer body of an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram thereof, and FIG. FIG. 4 is a side view showing the structure of a photosensitive member and a transfer member according to another embodiment. Further, FIGS. 5A and 5B are perspective views showing a joint portion of a photoreceptor and a transfer member, and FIG. 6 is a side view showing the structure of a conventional photoreceptor and transfer member. 1.6-photoconductor, 2-transfer body, 3-contact portion, 11-joint (of photoconductor), 12-(same) optical sensor,
13-(same) motor, 21-(transfer body) joint, 22-(same) optical sensor,
23-(same) motor,

Claims (1)

[Claims] (1) A method for controlling the rotation of a photoreceptor or a transfer body that is independently controlled in rotation and has a seam on at least one side, the seam being detected by a seam detection means, and based on the detection result of the seam detection means. The photoreceptor and/or transfer member are characterized in that the rotation of the photoreceptor and/or the transfer member with a seam is controlled so that the seam is not located at the mutual contact portion when the rotation of the photoreceptor and the transfer member is stopped. rotation control method.