JPS61140438A - Motor control method - Google Patents

Abstract

PURPOSE:To prevent vibration and noise of a motor by increasing the output torque of the motor when the forward end of a recording paper reaches just in front of pressure fixing rollers and decreasing the output torque when the recording paper passes through the rollers when controlling the motor for a copy machine and the like. CONSTITUTION:A motor 10 is driven after an input current to a pulse motor 9 is set at a normal current Ii. Then, whether the forward end of a recording paper 1 passes through a sensor 6 is discriminated. When it passes through the sensor 6, whether the forward end of the recording paper 1 travels a distance l is discriminated. When it travels the distance l, an output current to the pulse motor 9 is set at the maximum current Ih, thereby driving a fixing unit 8 at the maximum output torque so that the rollers of the fixing unit 8 hold the forward end of the recording paper 1. Then the motor 9 is drived. Next, whether the forward end of the recording paper 1 travels a distance n is discriminated. After it travels the distance n, the input current to the pulse motor 9 is returned to the normal current Ii and the recording paper 1 is discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of controlling a motor used in a copying machine, a facsimile machine, etc.

BACKGROUND ART Conventionally, when driving a conveyance roller or a fixing roller in a copying machine, facsimile machine, etc., the output torque of the motor was set in accordance with the maximum load.

Problems to be Solved by the Invention However, in the operating state of the device, the maximum load is not always applied to the motor, and in certain limited cases, for example, when the leading edge of the recording paper is held between the fixing rollers, the motor is Maximum load is applied. Therefore, under normal operating conditions, the motor outputs extra power, which, combined with the motor's damping characteristics, causes vibration and noise.

The present invention solves the above conventional problems, and aims to provide a motor control method that can reduce noise and vibration regardless of load fluctuations.

A means to solve a problem.

In order to achieve the above object, the present invention increases the output torque of the motor that drives the pressure fixing roller when the leading edge of the recording paper reaches just in front of the pressure fixing roller, so that the leading edge of the recording paper reaches just in front of the pressure fixing roller. It is characterized by reducing the output torque of the motor after passing through.

Since the output of the motor is increased or decreased in accordance with changes in the load due to the state of conveyance of the recording paper, the generation of noise and vibration can be effectively reduced.

Example The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram of a facsimile apparatus according to an embodiment of the present invention, and FIG. 2 is a flowchart for explaining the motor control in FIG. 1.

In FIG. 1, 1 is a recording paper wound into a roll, 2 is a feeding roller for feeding the recording paper 1 toward the left in the drawing, and 3
1 is a recording head that forms an electrostatic latent image on the recording paper 1, 4 is a platen roller, 6 is a cutter that cuts the recording paper 1 to a predetermined length, 6 is a sensor that detects the leading edge of the recording paper 1, and 7 is on the recording paper 1 A developing unit 8 is a pressure fixing unit that fixes the image on the recording paper 1 . Reference numeral 9 denotes a pulse motor, which connects a feed roller 2.degree., a platen roller 4. The pressure roller of the pressure fixing unit 8 and other recording paper transport rollers (not shown) are driven.

In facsimile machines, copying machines, and the like, the largest load on the motor 9 is due to the rollers of the pressure fixing unit 8. Figure 3 shows four types (A, B, C, D).
) is a graph of the load torque on the unit drive shaft when recording paper of different paper quality and the same thickness (75 μm) passes through the pressure fixing unit, and when the recording paper enters, that is, the roller of the unit clamps the leading edge of the recording paper. The torque at this time is approximately twice the torque during feeding of the recording paper.

On the other hand, as shown in FIG. 4, the output of the pulse motor is proportional to the input current value regardless of the amount of rotation. Therefore, in this embodiment, the maximum current value is inputted to the pulse motor by setting the maximum load when the recording paper enters the pressure fixing unit, and the corresponding normal current value I is set as the normal load while the recording paper is passing. input.

Returning to FIG. 1, e is the distance from when the leading edge of the recording paper 1 passes the sensor 6 until just before it enters the roller of the pressure fixing unit 8, and n is the distance after the leading edge of the recording paper 1 enters the pressure fixing unit 8. This is the distance that includes the security required to pass.

The operation of the above embodiment will be explained below with reference to the flowchart of FIG.

First, in step (hereinafter referred to as ST) 21, the input current to the pulse motor 9 is set to the normal current value I, and then the motor 10 is driven (ST22).

Next, at 5T23, it is determined whether the leading edge of the recording paper 1 has passed the sensor 6, and if it has not passed yet, the 5T
Return to 22. If the leading edge of the recording paper 1 has passed the sensor 6, the process advances to BT24, where it is determined whether the leading edge of the recording paper 1 has traveled a distance l. If the distance e has not been traveled yet, the process returns to 5T22.

At 5T24, if the leading edge of the recording paper 1 has traveled a distance e, the process advances to 5T25, where the input current value to the pulse motor 9 is set to the maximum current value, and the fixing unit 8 is driven with the maximum output torque. The roller of the fixing unit 8 is connected to the recording paper 1.
(ST26). Then, the motor 9 is driven (ST26).

Next, at 5T27, it is determined whether the leading edge of the recording paper 1 has traveled a distance n (distance 6+n from the sensor 6), and if it has not traveled yet, the process returns to 5T26. After traveling the distance n, the process advances to 5T28, where the input current value to the pulse motor 9 is returned to the normal current value I, and the recording paper 1 is ejected.

In the embodiment described above, the input current value is controlled as a method of changing the output torque of the pulse motor, but the input voltage value may be controlled instead.

Furthermore, as shown in Figure 5, in a pulse motor, the number of pulses and the output torque are inversely proportional, so the number of pulses is low (f1 in the figure) at maximum load, and the number of pulses is high (f1 in the figure) at normal load.
It is preferable to drive it at f2) shown in the figure.

In the above embodiment, the time when the recording paper passes through the pressure fixing unit is defined as the normal load because, in facsimile machines and the like, the time when the pressure fixing unit is idling is compared to the time when the paper is passing. This is because it is very short. Alternatively, a plurality (n) of sensors may be provided to detect the recording paper, and the output torque of the motor may be controlled in n stages.

Effects of the Invention As explained above, since the output torque of the motor is maximized only at the maximum load, it is possible to prevent motor vibration and noise, and furthermore, heat generation from the motor is reduced. I can do it.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a facsimile machine according to an embodiment of the present invention, Fig. 2 is a flow chart for explaining the motor control in Fig. 1, and Fig. 3 shows the load torque of the drive shaft of the pressure fixing unit. 4 is a graph showing the output torque of the pulse motor when the input current value is changed, and FIG. 5 is a graph showing the relationship between the number of input pulses and the output torque of the pulse motor. 1...Recording paper, 6...Sensor, 8...
...Pressure fixing unit, 9...Pulse motor, a...Distance from the sensor force to just before the roller of the pressure fixing unit, n...The leading edge of the recording paper Distance from entering the pressure fixing unit until it passes, Ih...
...Motor maximum input current value, Ii ...Motor normal input current value. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure Tomi Otsu Story & Sleeping Night C No. 1 Go 4 Door JPM No. 41!

Claims (1)

[Claims] When the leading edge of the recording paper reaches just before the pressure fixing roller,
A motor control method comprising increasing the output torque of a motor that drives the pressure fixing roller, and reducing the output torque of the motor after the leading edge of the recording paper passes the pressure fixing roller.