JPS6190172A - Developing device - Google Patents

Abstract

PURPOSE:To control a rotating body to steady rotation independently of the variation of the load of a rotating body by rotating the rotating body before the start of the image forming operation of a rotary developing device and varying the set value of a speed control table in accordance with a detection signal. CONSTITUTION:By an interrupt from a timer 109, a controller 106 compares the value in a position counter 110 for preceding rotation with the value in the speed control table and calculates the difference. The speed control table consisting of several position data corresponding to the value at a certain time of the position counter 110 and this difference are set in a ROM104. The difference between the speed at a prescribed time in the preceding rotation and the set speed of the speed control table is obtained, and a new set value is selected from the speed control table in accordance with the difference and is read into a RAM105. This operation is repeated for a prescribed time to generate a new speed control table in the RAM105, and the rotating body is controlled smoothly at the actual rotation time in accordance with values of this generated table.

Description

Detailed Description of the Invention (Scope of Industrial Application) The present invention relates to a developing device, and particularly to a developing device suitably used in a color copying machine or a color recording device that sequentially develops color-separated images. .

(Prior Art) Conventionally, as shown in Fig. 1, developing units filled with different color developers are provided at regular intervals in the circumferential direction of a rotating body, and the rotating body is intermittently exposed for each exposure. In a rotary developing device that is characterized by rotating and positioning a developing device corresponding to the surface of a member to be developed for each exposure, a rotary developing device using a rotation control method using a nervomotor as a method for driving the rotating body is known. ing.

(Problems to be Solved by the Invention) However, due to the nature of the rotary developing device, as it rotates sequentially, its load constantly fluctuates due to the consumption of each color toner.

Further, each toner does not decrease uniformly for each color, but decreases unevenly. Due to this load fluctuation, steady rotation may not be possible only by controlling the servo motor described above, which causes rotational positioning time, impact vibration, etc., and adversely affects images.

(Objective) The present invention aims to eliminate the drawbacks of the above-mentioned conventional example.

(Means for solving the problem) For this purpose, by rotating the rotating body before starting the image forming operation (hereinafter referred to as forward rotation), the load fluctuation is detected,
Correspondingly, the signal is sent within the servo control circuit to change the set value of the rotational speed and pulse of the servo motor, that is, the set value of the speed control table, thereby controlling the servo motor to steady rotation.

Due to these factors, during image forming operation (hereinafter referred to as main rotation), rotation is smooth, development positioning time,
Imaging, impact, etc. can be reduced.

(Example) Hereinafter, details of the present invention will be explained based on specific illustrated examples.

Figure 1 shows an example of applying the present invention to a color copying machine.
FIG. 2 is a perspective view of an embodiment based on the present invention, and FIG. 3 is a block diagram thereof. The rotary developing device rotating body (4) includes:
yellow.

Equipped with four color development units 4Y, 4M, 4C, and 4BK that have magenta, cyan, and black toner.
In the figure, the yellow developing device 4Y is set at the developing position. A latent image is formed on the photoreceptor 1 by the exposure E of the yellow image, which is developed by the yellow developer, and then transferred to the transfer paper held by the transfer drum 6 at the edge of the mesh screen. The image is transferred onto the transfer paper by corona discharge.

Next, after cleaning and charging the photosensitive drum 1, a similar process is performed for magenta, cyan, and black, and the transfer paper on which multiple transfers have been made is separated from the transfer drum 6 and conveyed.

The image passes through the fixing device 15 and a full color image is formed.

FIG. 2 shows a method for rotationally driving a rotary developing device according to the present invention. The rotating body 4 of the rotary developing device is rotationally driven by a servo motor 100, and the yellow, magenta, cyan, and black developing units 4Y, 4M, 4C, and 4BK are sequentially rotated and moved to developing positions in contact with the photoreceptor 1, thereby performing development. Do this.

Also, the detection of the developing device installed at this time was installed at the rear of the rotating body (not shown)! Cycloswitch 25Y,
25, and the developing device at the developing position is detected by photosensors 24Y and 24M provided on the main body side.

240, 248K and a reflecting plate 23 fixed to the rotating body shaft 4b.

FIG. 3 is a block diagram showing control of the servo motor 100. Control is performed according to a rotary encoder 113 connected to motor 100K. Here, the position is detected by using the speed as an integrated value based on the number of pulses output from the encoder 113 per unit time. That is, the speed counter 108 is counted by pulses from the encoder 113, cleared at regular intervals by the external timer 109, and at the same time, the value is latched and output.

The external timer 109 is also connected to an interrupt terminal of the controller 106, and interrupts the controller 106 at regular intervals. Position color/ri 110ti
It is counted by pulses from the encoder 113 and cleared at each start of movement. ) A speed control table composed of position data corresponding to a fixed unit time is set in the LOM 104. FIG. 4 shows this speed control table. The controller 106 controls the timer 1
Due to an interrupt from 09, the position counter 11 at the time of previous rotation
The value of 0 is compared with the value of the speed control table to calculate the deviation ΔSushi. FIG. 5 shows a graph showing the speed fluctuation during the previous rotation, and FIG. 6 shows an explanatory diagram in which the speed control table (a) and the speed fluctuation during the previous rotation (b) are superimposed.

Further, as shown in FIG. 7, the ROM 104 is stored in accordance with this deviation ΔNi and the value 1i of the position counter 110. A new set value nI' is prepared in advance. As a result, the setting value of the speed control table when the position counter is ti is corrected, and this new layer setting value nI' is
By loading it into MI 05, a new speed control table can be created.

To explain in more detail, for example, if the speed during the previous rotation at time t2 is N2, and the set speed of the speed control table at this time is 02, then the deviation ΔNz=nz Nz torque. Depending on the value of this ΔN2, the new setting value n2
' in the table of Figure 7 as ``!-1+n'+-z + nz
@n'z-3+ n'z-a Yo! + Selection L,
The new h value is read into the RAM (105).

In this way, a new speed control table can be created by persistently performing similar operations until time tl-ti.

In Fig. 7, the case classification based on the size of ΔN is
(-a, -a≦ΔN〈O, ΔN = 0.

0〈△N≦a, ΔN)a, divided into 5 types Ic, n
' is selected, but it is easy to understand that the rotation can be made even smoother by subdividing the cases.

The above operations are performed by performing in-rotation.

During the subsequent main rotation, the controller 106 operates the timer 1 according to the speed table consisting of the new setting values.
09, the values of the position counter 110 and speed counter 108 are read into the RAM 105. The value is compared with the value in the speed control table, a predetermined calculation is performed on the deviation, and the result is sent to the D/man converter 111, whereby the motor 100 is changed to 4. Speed control is performed by changing the number of laps: Then, when the value of the position counter 110 reaches the final target value, the motor 100
The torque is turned OFF' and the rotational movement is completed. FIG. 8 shows a 70-chart showing these controls.

(Effect of the invention) As described above, in the present invention, the pre-rotation is performed before the main rotation, and the speed characteristics are read.
By changing the setting value of the speed control f-7'# in the controller, rotation control is performed using the new setting value during the main rotation. This enables smooth control of the rotating body.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a color electrophotographic apparatus to which the present invention is applied. FIG. 2 is an explanatory diagram of the rotary developing device of the present invention. FIG. 3 is a block diagram of the control section of the present invention. FIG. 4 is an explanatory diagram of the relationship between rotation speed and time in an initial state. FIG. 5 is an explanatory diagram of the relationship between the rotation speed and time after load fluctuation. FIG. 6 is a comparison diagram of graphs showing the relationship between the initial state and the rotational speed per hour after load fluctuation. FIG. 7 is an explanatory diagram showing the contents of memory regarding new setting values. FIG. 8 is a flowchart showing the control of the present invention. In the figure, 1 is a photoreceptor, 4-piece developing device 23° 24Y, 2
4M, 24C, 248 are developing device position detection means, io
o indicates a motor.

Claims (3)

[Claims] (1) In the drive control of the rotary body in a rotary developing device in which a plurality of developing units are removably mounted on a rotary body and rotated to a predetermined development position for each development, load fluctuations on the rotary body are controlled. A developing device characterized in that the detection is performed by rotating a rotating body before starting an image forming operation, and varying a setting value of a speed control table based on the detection signal. (2) In the speed control of the rotating body, the speed during rotation before the start of the image forming operation is compared with a value in a speed control table, and the load fluctuation of the rotating body is detected based on the deviation. Developing device according to scope 1. (3) A patent for controlling the speed of the rotating body by modifying the set value of the speed control table based on the load fluctuation detection signal, creating a new speed control table, and performing rotation during image forming operation using the speed control table. A developing device according to claim 1 or 2.