JPS6293153A - Paper feed control device for copying machine - Google Patents

Abstract

PURPOSE:To enable precise positioning of a paper sheet, by cutting an electromagnetic clutch to disable the rotation of register rollers during resting of the drive of the register rollers so that skew correction may be made during the resting of the rotation without the paper sheet entering into between the register rollers. CONSTITUTION:A solenoid clutch 1 is disengaged to stop the transmission of the drive force of a motor 9 to register rollers 7, and a CPU 15 energizes an electromagnetic brake 13 to completely stop the register rollers 7. In this condition a paper sheet is made into contact with the register rollers 7 to perform skew correction. Then, the CPU 15 releases the brake 13 and engages the electromagnetic clutch 11 to rotate the register rollers 7 by means of the motor 9 for conveying the paper sheet. Accordingly, it is possible to perform skew correction during the resting of rotation of the register roller 7 without the paper sheet entering into between the register rollers 7 so that precise positioning of the paper sheet may be made. Further, the register rollers 7 may be rapidly stopped to allow the waiting time of the paper sheet may be shortened, thereby it is possible to make the speed of the paper feed higher.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feed control device for a copying machine, and more particularly to a paper feed control device in which a registration roller is provided with a brake mechanism.

[Conventional technology]

Conventionally, there is a paper feeding mechanism for a copying machine as shown in FIG. 4, for example.

The paper stored in the paper tray 1 is conveyed by the feed roller 3 in the six directions indicated by the arrows in the figure, and then transferred to the copying drum 5.
The image is transferred to this paper using the following steps. The registration roller 7 conveys the paper while its rotation is controlled by an electromagnetic clutch mechanism (not shown) in order to adjust the position of the copy image on the copying drum and the paper. That is, the electromagnetic clutch mechanism is turned on and off to intermittently drive the registration roller rough so that the copy image on the copy drum 5 and the paper are aligned.

[Problem that the invention seeks to solve]

However, in such a conventional paper feeding mechanism, the registration roller 7
There is a problem in that paper skew cannot be corrected because the paper is kept on standby with the paper being nipped.

Further, when the load on the registration rollers 7 is small, even if the electromagnetic clutch is disengaged to stop the registration rollers 7, the paper may get stuck in the registration rollers 7ffi, and accurate positioning may not be possible.

The present invention has been made to solve the above-mentioned problems.
The purpose of this is to provide a paper feed control device for a copying machine that can perform skew correction, and that can perform accurate positioning without allowing the paper to get between the registration rollers 7. .

(Summary of the Invention) To achieve this object, the present invention provides a copying machine for copying onto paper using a copying drum, which comprises at least two rollers facing each other, and the paper is sandwiched between the opposing rollers so that the copying drum a registration roller that is conveyed in a direction, a motor that drives the registration roller, an electromagnetic clutch that connects and disconnects the transmission of the driving force of the motor to the registration roller, a brake that stops rotation of the registration roller, and the motor/electromagnetic clutch and The present invention is characterized by comprising a control means for controlling the brake.

(Operation) After disengaging the electromagnetic clutch to prevent the driving force of the motor from being transmitted to the registration rollers, the control means operates the brake to completely stop the registration rollers. In this state, the paper is brought into contact with the registration rollers and skew correction is performed. Next, after releasing the brake, the control means connects the electromagnetic clutch and transmits the driving force of the motor to the registration roller to rotate the registration roller and convey the paper.

〔Example〕

An embodiment of the present invention will be described in detail below based on the drawings.

FIG. 1 shows the paper feed of the copying machine according to this embodiment.
FIG. 1 is a configuration block diagram of a device. As shown in the figure, an electromagnetic clutch 11 is provided between the registration roller 57 and the main motor 9 that rotationally drives the registration roller 7, and the rotational driving force from the main motor 9 to the registration roller 7 is changed by connecting and disconnecting the electromagnetic clutch 11. Transmission is interrupted. Further, an electromagnetic brake 13 is attached to the registration roller 7 to completely stop the rotation of the registration roller 7.

A central processing unit (CPU) 15 operates a main motor drive circuit 21 . N magnetic latch drive circuit 23. The main motor 9 via the electromagnetic brake drive circuit 25. Controls the clutch 11 and brake 13.

FIG. 2 is a detailed circuit diagram of the electromagnetic clutch drive circuit 23 and the electromagnetic brake drive circuit 25.

An electromagnetic clutch 11, which controls the rotation of registration rollers (not shown), is connected to the collector of a first switching transistor 29 via a connector 27.

The emitter of the first switching transistor 29 is connected to a power source 31, and when the first switching transistor 29 is conductive, a voltage is supplied from the power source 31 to the electromagnetic clutch 11.

An electromagnetic brake 13 for stopping rotation of the registration roller is connected to a collector of a second switching transistor 35 via a connector 33. The emitter of the second switching transistor 35 is connected to the power supply 37, and when the second switching transistor 35 is conductive, the current I! Voltage is supplied from 37 to the electromagnetic brake 13? ! The magnetic brake 131I18 is activated to stop the rotation of the registration roller.

The CPU 15 generates a first control signal S1 and a second control signal S2 for turning the first switching transistor 29 and the second switching transistor 35 on and off. 1st
The control signal S1 is applied to the AND gate 39. Inverter 41. The second control signal S2 is input to the base of the first switching transistor 29 through the resistor 43, and the second control signal S2 is input to the AND gate 45.
．． Inverter 47. It is input to the base of the second switching transistor 35 via the resistor 49. Further, the first control signal S1 is inputted to the other input terminal of the AND gate 45 via the inverter 51, and the second control signal $2 is inputted to the other input terminal of the AND gate 39 via the inverter 53. This inverter 51, 53 and AND gate 39
．． 45 is a circuit for preventing the electromagnetic clutch 11 and the electromagnetic brake 13 from operating simultaneously even if the first control signal S1 and the second control signal S2 become 1' at the same time due to a failure or the like. It is.

Next, the operation will be explained based on FIG.

Figure 3(a) is a waveform diagram of the voltage applied to the electromagnetic clutch 11, Figure 3(b) is a waveform diagram of the voltage applied to the electromagnetic brake 13, and Figure 3(C) is a waveform diagram of the voltage applied to the electromagnetic brake 13. It is an explanatory diagram.

In the initial state, it is assumed that the electromagnetic clutch 11 is engaged, the electromagnetic brake 13 is disengaged, and the registration roller 7 is rotating at a constant angular velocity.

Time t. When the CPL 115 receives the input signal S3 from the sensor 19 or the signal S4 sent from the feed motor or the like, it sets the first control signal S1 to 0'.

At this time, since the second control signal S2 is also 0', the outputs of the AND gates 39.45 are both O', and both the first and second switching transistors 29.35 are not conductive, and the electromagnetic clutch 11 is disconnected, causing the register low. The rotation of 57 becomes slower. At time t1, when time T has elapsed from time t0, C
In the PLJ 15, by setting the second control signal S2 to 1', the second transistor 35 becomes conductive, voltage is supplied from the power supply 37 to the electromagnetic brake 13, the electromagnetic brake 13 is operated, and the registration roller 7 is completely stopped. And Rejiro 57
While the paper is stopped, the paper is conveyed and is brought into contact with this registration roller 7 to perform skew correction.

At time t2, the CPU 15 sets the second control signal S2 to 0'.
After stopping the operation of the electromagnetic brake 13, at time t3, the first control signal S1 is set to 1', the first switching transistor 29 is made conductive, and the electromagnetic clutch 11 is connected, thereby rotating the registration roller 7.
Transports paper.

At times t4 and t5, the same operation as at times t□ and tl is performed, and thereafter this operation is repeated to carry out skew correction while conveying the paper.

Note that even if the first and second control signals 81, 82 both become 1', the AND gate 29.
Since the outputs of the transistors 35 are both 0' and the first and second switching transistors 17 and 21 are both turned off, the electromagnetic clutch 11 and the electromagnetic brake 13 are not operated at the same time.

〔Effect of the invention〕

As explained in detail above, according to the present invention, when the electromagnetic clutch is disengaged and the registration roller is not driven to rotate, the brake makes the registration roller completely unrotatable, so skew correction is performed while the registration roller is stopped rotating. Moreover, the paper does not get stuck between the registration rollers during skew correction, and accurate positioning can be performed.

Furthermore, since the registration rollers can be stopped quickly, the time during which paper is kept on standby can be shortened, and copying can be performed at high speed.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram of a paper feed control device for a copying machine according to an embodiment of the present invention, FIG. 2 is a detailed circuit diagram of an electromagnetic clutch drive circuit 23 and an electromagnetic brake drive circuit 25, and FIG. 3(a) is a waveform diagram of the voltage applied to the electromagnetic clutch 11, FIG. 3(b) is a waveform diagram of the voltage applied to the electromagnetic brake 13, FIG. 3(C) is an explanatory diagram of the rotation speed of the registration roller, and FIG. 1 is a schematic configuration diagram of a paper feeding mechanism of a copying machine. 7... Registration roller, 9... Main motor, 11...
・Electromagnetic clutch, 13...Electromagnetic brake, 15...
cpu. Figure 1 Figure 4

Claims (1)

[Scope of Claims] A copying machine that copies onto paper using a copying drum, comprising at least two rollers facing each other, a registration roller that sandwiches the paper between the opposing rollers and transports the paper toward the copying drum; a motor that drives a registration roller; an electromagnetic clutch that connects and disconnects transmission of the driving force of the motor to the registration roller; a brake that stops rotation of the registration roller; and a control means that controls the motor, electromagnetic clutch, and brake. A paper feed control device for a copying machine, comprising: