JPH0365552B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a copying machine, and more particularly to a photoconductor drum stop position control device for a copying machine that controls the stop position of a photoconductor drum having a non-image area such as a seam.

The photoreceptor drum of a copying machine is provided with non-image areas such as seams (uncoated areas).
The stopping position of the photosensitive drum must be within a predetermined range. The reasons for this are: (a) If the toner cleaning blade is constantly in contact with the photoconductor coated surface when the photoconductor drum is stopped, the quality of the photoconductor will change, and (b) it will overrun from a predetermined stop position and stop. Then, the next time you copy, you will have to play once,
This is because the ejection time for the first copy becomes longer.

As a countermeasure against (a) above, a method has been proposed in which the toner cleaning blade is moved away from the photoreceptor drum by, for example, activating a solenoid after the photoreceptor drum has stopped. Runs are out of control.

For (b) above, a device is used that applies a brake to the photoreceptor drum drive motor to control its stop position. Although this device can reduce the amount of overrun, it does not change the stop position. I can't control it.

The present invention has been made in view of the above, and it is possible to keep the stop position of the photosensitive drum of a copying machine within a predetermined range even if there are fluctuations in power supply voltage, changes in load, or changes in parts (motor, etc.). Therefore, a microcomputer is used to generate a stop timing signal for the photoreceptor drum during stop control by comparing the stop position of the photoreceptor drum at the end of each copy with the reference stop position of the photoreceptor drum for each copy. A photosensitive drum stop position control device is provided.

The photosensitive drum stop position control device for a copying machine according to the present invention will be described in detail below.

FIG. 1 shows an embodiment of the present invention, in which a photoconductor drum 10 having a photoconductor seam 11 provided inside a copying machine main body 1, and a photoconductor drum 10 fixed to the photoconductor drum 10 outputting a timing signal to be described later. A timing disk 12 having a notch 12a for
, a photosensor 13 made up of a light emitting diode and a phototransistor, which detects the rotation of the timing disk 12 and outputs a timing signal consisting of, for example, a reference pulse with a large pulse width and a plurality of clock pulses with a small pulse width; an input interface; A microcomputer 14 includes a ROM, RAM, CPU, output interface, etc., and inputs and processes timing signals and outputs them as stop signals for the motor 15. A microcomputer 14 inputs output signals from the microcomputer to drive and stop the photosensitive drum drive motor 15. The drive circuit 16 is shown.

In the above configuration, the operation will be explained with reference to the timing chart in FIG.
1, the photocoupler 13 outputs a timing signal (consisting of a reference pulse S and a clock pulse C, only a portion of which is shown) as shown in FIG. When the microcomputer 14 outputs a control signal to turn off the power to the drive circuit 16 at a time _ty (three examples of _ty1 , _ty2 , and _ty3 are shown) obtained by counting clock pulses C, the time t _z ( The photoreceptor drum 10 stops at t _z1 , t _z2 , and t _z3 , which correspond to t _y1 , t _y2 , and t _{y3 ,} respectively). Photosensitive drum 1
The reference stop position of 0 is predetermined as point P, and points P ₁ and P ₂ are given as allowable width (point P and points P ₁ and P ₂ have a time width of Δt). The stop time t _z1 is when the photoreceptor drum 10 stops before reaching the allowable point P ₁ , the stop time t _z2 is when it stops after entering the allowable range, and the stop time t _z3 is when the photoreceptor drum 10 stops before reaching the allowable point P 1 . This is the case when the vehicle stops after passing.
Next, when the photoreceptor drum 10 is driven, the microcomputer 14 determines the time T _z (corresponding to the above three examples, T _z1 ,
T _z2 , T _z3 ) is detected and stored (stored in RAM), and compared with the pre-stored time Tx from the reference stop position P until the reference pulse S is detected (the CPU stores it in the ROM). (calculated based on the program). This calculation is, for example, to find Tz-Tx=Tδ and find the difference (Tz-Δt) between this Tz and the time width Δt, and the following control is performed according to this difference.

(1) When Tz<Δt The power to the motor 15 is turned off at time t _y2 ,
When the photosensitive drum 10 stops at time t _z2 and is within the allowable widths P ₁ and P ₂ , control will be performed at this timing next time as well.

(2) When |Tδ| > Δt (2.1) When Tδ > 0 When the motor 15 is powered off at time t _y1 and the photosensitive drum 10 stops at time t _z1 , the permissible point P ₁ is reached. Therefore, the power to the motor 15 is turned off after a delay of time |Tδ| from time t _y1 .

(2.2) When Tδ<0 The power to the motor 15 is turned off at time t _y3 ,
In the case where the photosensitive drum 10 stops at time t _z3 , it will stop after passing the allowable point P ₂ , so the motor 15 is powered off after advancing by time |Tδ| from time t _y3 .

FIG. 3 shows a flowchart of the above operations.

As explained above, according to the photoconductor drum stop position control device for a copying machine of the present invention, the microcomputer compares the stop position of the photoconductor drum at the end of copying with the reference stop position of the photoconductor drum for each copy. Since a stop timing signal for the photoreceptor drum is generated during stop control, the stop position of the photoreceptor drum of the copier can be maintained at a predetermined position even if there are fluctuations in power supply voltage, changes in load, or changes in parts (motor, etc.). can be kept within the range of

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an automatic photosensitive drum stop position control device for a copying machine according to the present invention. FIG. 2 is a photosensitive drum stop timing chart showing one embodiment of the present invention. FIG. 3 is a flowchart showing one embodiment of the present invention. Explanation of symbols, 1... Copying machine main body, 10... Photoconductor drum, 11... Photoconductor joint, 12... Timing disk, 13... Photocoupler, 14
... Microcomputer, 15 ... Photoreceptor drum drive motor, 16 ... Motor drive circuit, 17 ... Start button.

Claims (1)

[Scope of Claims] 1. A photoreceptor drum, a driving means for driving the photoreceptor drum, a control means for controlling rotation of the photoreceptor drum, and a control means for controlling the rotation of the photoreceptor drum in synchronization with the rotation of the photoreceptor drum. The control means generates a plurality of clock pulses C indicating that a plurality of positions on the surface of the photoreceptor drum are passing through a predetermined position and a reference pulse S indicating that a reference position on the surface of the photosensitive drum is passing a predetermined position. a reference value representing the number of clock pulses C corresponding to the distance from the position where the reference position on the surface of the photosensitive drum should stop to the predetermined position corresponding to the reference pulse S; Tx, a first numerical value ty representing the number of clock pulses C that determines the timing at which the control means outputs a command to stop the rotation of the photoreceptor drum to the drive means, and an actual value of the reference position on the surface of the photoreceptor drum. A copying machine comprising: a storage means for storing a second numerical value Δt corresponding to an allowable error range in which an error between a stop position and the position to be stopped is allowable; The number of clock pulses C input during the period after the rotation start command is output until the reference pulse S is input is counted and stored in the storage means as a third numerical value Tz, and from this third numerical value Tz The absolute value |Tδ| of the difference Tδ obtained by subtracting the reference numerical value Tx is compared with the second numerical value Δt, and if the absolute value |Tδ| is larger than the second numerical value Δt, the The sum obtained by adding the difference Tδ to the first numerical value ty is
The clock pulse C is stored as a numerical value ty in the storage means, and after the reference pulse S is input, the clock pulse C is
The number of inputs is counted, and the counted value and the first numerical value ty
The copying machine is characterized in that when the two match, a command to stop the rotation of the photosensitive drum is output to the driving means.