JPS63169670A - Rotation control method for photosensitive body and transfer body - Google Patents

Abstract

PURPOSE:To prevent a formed image from deteriorating in quality by abutting a photosensitive body and a transfer body each other in a no-image formation area at the time of the rotation stop of the photosensitive body and transfer body. CONSTITUTION:No-image formation areas 11 and 21 of the photosensitive body 1 and transfer body 2 are detected by photosensors 12 and 22, whose detection signals are inputted to a CPU 5, which controls the rotating states of both rotary bodies to form an image. When the area 11 passes the position of the sensor 12, a timer operate to clock the off timing of a motor 13. This clocking time is set to the time when the area 11 reaches an abutting part 3. The area 11 is therefore positioned at the abutting part 3 at the rotation stop of the photosensitive body 11. Similarly, the area 21 is positioned at the abutting part 3 at the time of the rotation stop of the transfer body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION 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 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 body is shown in Figure 4 (A) and (B).
), this is done by tape adhesion and fusing. As shown in FIG. 4(A), when tape adhesion is used, 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. 4(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 car stopped and was left in contact with a part other than the seam.For example, the 5th
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. Ta.

In view of the above, the present invention provides a photoconductor that can prevent deterioration in the quality of formed images by bringing the photoconductor and transfer body into contact in a non-image forming area when the rotation of the photoconductor and transfer body is stopped. An 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 member that is independently rotationally controlled and has a non-image forming area along the direction of each rotation axis, the method comprising: The image forming area is detected by a detection means, and based on the detection result of the detection means, the photoreceptor, It is characterized by controlling the rotation of the transfer body.

(e1 effect In the method for controlling the rotation of the photoreceptor and transfer member of the present invention,
The rotation of the photoreceptor and the transfer member is independently controlled, and during the rotation, non-image forming areas of the photoreceptor and the transfer member are detected by a detection means. Depending on the detection result, that is, the position of the non-image forming area, the timing of when the photoreceptor and transfer member stop rotating is controlled, and the non-image forming area of the photoreceptor and the non-image forming area of the transfer member are in contact with each other. The photoreceptor and transfer body stop.

Tf) 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 FIG.

The photoreceptor 1 is in the form of a belt stretched between a pair of rollers.
A non-direct imaging area 11 including a seam 14 is formed by tape or fusing. The transfer body 2 is also in the form of a belt stretched between rollers, and has a non-image forming area 21 including a seam 24 . The circumferential length of the photoreceptor l in this embodiment is exactly twice the circumferential length of the transfer body 2. Therefore, when the photoconductor 1 and the transfer body 2 rotate synchronously, the transfer body 2 rotates twice while the photoconductor 1 rotates once, and the joint 24 of the transfer body is the same as the joint 14 of the photoconductor. 14 in the opposite position twice. Therefore, the position opposite to the seam 14 also serves as a non-image forming area 11.

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 a CPU, which will be described later.During an image forming process, the photoreceptor 1 and the transfer member 2 rotate in synchronization at the same circumferential speed. Note that, at the start of the image forming process, the photoreceptor 1. After adjusting the rotation speed of the transfer body 2 by increasing or decreasing it, the rotation speed is synchronized.

A notch (not shown) is formed at the end of the non-image forming area 11.21, and transmissive optical sensors 12 and 2 are mounted on the photoreceptor 1 and the transfer body 2 so as to face the notch.
2 are arranged. The optical sensors 12.22 are each
As the photoreceptor 1 and the transfer body 2 rotate, when the non-image forming areas 11 and 21 face the optical sensors 12 and 22, the non-image forming area (notch) is detected and turned on.

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. A photosensor 12 that detects the non-image forming area 11 of the photoreceptor. An ON signal from the optical sensor 22 that detects the non-image forming area 21 of the transfer member is input to the CPU 5 via the l1053. Based on this ON signal, the CPU 5
The rotation status of the photoconductor 1 and transfer body 2 can be known by the program stored in the M51.
5 is connected to the photoreceptor motor 13.5 via l1054. On/off signals are output to the drivers 55 and 56 of the transfer body motor 23. The CPU 5 outputs an on signal to the drivers 55 and 56 at the start of the image forming process, and outputs an off signal 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. 3A shows the operation of the photoreceptor motor 13, and FIG. 1B shows the operation of the transfer member motor 23. First, the operation of the photoreceptor motor 13 will be explained.

Ste Nobu nl (hereinafter, “step ni” will simply be “ni”)
When the image forming start switch (not shown) is turned on at step n2, the image forming process starts, and at step n2, the photoreceptor motor 13 is turned on and the photoreceptor 1 moves in the direction of arrow A in FIG.
The image forming process is performed at 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 is completed at n4, the process proceeds to n5, where it is determined whether the optical sensor 12 of the photoreceptor is on or off. When the non-image forming area 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, and the process proceeds to n6, where timer T1 is started. When the timer TI times up at nl, 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 nl to wait for the start of the image forming process.

The timer T1 measures the off timing of the motor 13, and the time measured by the timer T1 is equal to the time when the non-image forming area 11, which has passed through the location where the optical sensor 12 is disposed, reaches the contact portion 3. It is set. Therefore, when the photoreceptor 1 stops rotating, the non-direct image forming area 11 of the photoreceptor is 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 ends at -=n4, the on/off state of the photosensor 22 of the transfer body is determined at nlo. When the non-image forming area 21 of the transfer body passes through the location of the optical sensor 22, the optical sensor 22 is turned on and its signal is inputted.
Proceeding to ll, timer T2 is started. And n1
When the timer T2 times up in step 2, the process advances to n13, the motor 23 is turned off and the rotation of the transfer body 2 is stopped, and the process returns to n1 to wait for the start of the image forming process.

The timer T2 is used to time the off timing of the motor 23, and the time measured by the timer T2 is the time taken for the non-image forming area 21 to reach the contact portion 3 after passing through the location where the optical sensor 22 is disposed. is set to . Therefore, when the transfer body 2 stops rotating, the non-image forming area 2 of the transfer body
1 is now located at the contact portion 3.

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.

(g) 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 detection means detects a non-image forming area of the photoconductor or transfer body. Based on the results, it was determined that the non-image forming areas of both the photoconductor and transfer body should be stopped so that they are located at the contact area between the photoconductor and the transfer body, and that even if the photoconductor or transfer body is left in that state and dents or scratches occur. Since no image is formed in that area, the quality of the formed image will not be degraded.

[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. 3 is a side view showing the configuration of a transfer body. 4(A) and 4(B) are perspective views showing a joint portion of a photoreceptor and a transfer member, and FIG. 5 is a side view showing the structure of a conventional photoreceptor and transfer member. 1-;&-photoreceptor, 2-transfer body, 3-contact part,

Claims (1)

[Claims] (1) A method for controlling the rotation of a photoconductor or a transfer body that is independently rotationally controlled and has a non-image forming area along the direction of each rotation axis, the method comprising: detecting the non-image forming area with a detection means; Based on the detection result of the detection means, the rotation of the photoconductor and the transfer body is controlled so that the non-image forming area is located at the contact portion of the photoconductor and the transfer body when the rotation of the photoconductor and the transfer body is stopped. A method for controlling the rotation of a photoconductor and transfer body.