JPH07101594A - Paper feeding device - Google Patents

Abstract

PURPOSE:To perform the excellent feed of a paper sheet by controlling variation of the generation of torque of a motor according to the thickness of a paper sheet. CONSTITUTION:A rotation feed means to feed a paper sheet is provided. A motor 8 to rotationally drive a rotation feed means is provided. A paper thickness detecting means 11 to detect the thickness of a paper sheet is arranged on the upper stream of a paper sheet feed route through a rotation feed means. When the paper sheet has a thin section, a current flowing to a motor 8 is reduced by a current control means 34 to effect slow up starting. When the paper sheet has a thick section, a current flowing to the motor 8 is increased by the current control means 34, the speed of a slow up starting is increased and torque is increased. This constitution increases a current flowing to the motor 8 even when the paper sheet has a thick section, and increases the speed of a slow up starting and increases torque to stabilize the feed of the paper sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a facsimile,
The present invention relates to a paper feeding device that is used for a paper feeding path of equipment such as a printer and a copying machine and that feeds paper.

[0002]

2. Description of the Related Art Conventionally, a sheet feeding device of this type has a structure in which, for example, a feed roller and a pinch roller for pressing the sheet against the feed roller are faced in a sheet feeding path, and the feed roller is rotationally driven by a motor. . Then, when the sheet sent from the upstream side of the sheet feeding path is detected by the sheet sensor or the like arranged on the upstream side of the feeding roller position, the motor is started to rotate the feeding roller, and the feeding roller and the pinch roller are connected. The paper is sandwiched between the paper and the paper is fed in the downstream direction of the paper feed path.

When a constant current is supplied to the motor at the time of starting the motor, the motor starts to slowly increase so that the rotational speed of the motor gradually increases and the torque gradually increases to a predetermined stable rotational speed. When it reaches, the torque of a predetermined magnitude is obtained and maintained.

[0004]

By the way, when the thickness of the paper is different, the stiffness of the paper is also different. Therefore, the feeding resistance of the paper in the curved portion in the paper feeding path is changed and the feeding is also changed. The rotation resistance of the feed roller and the pinch roller changes in accordance with the change in the moving amount of the feed roller and the pinch roller in the separating direction when the paper is nipped between the roller and the pinch roller, and the feed resistance also changes.

However, since the conventional sheet feeding device starts up by supplying a constant current to the motor at the time of starting the motor slow-up, regardless of the change in the sheet thickness of the sheet, the sheet feeding device changes the sheet feeding resistance. On the other hand, the torque generation of the motor cannot be coped with, and particularly when the paper thickness is thick, the feed resistance is large. Therefore, if the generation of the motor torque is delayed, the paper feed tends to become unstable.

However, since the conventional paper feeding device operates by supplying a constant current to the motor regardless of the change of the paper thickness of the paper, the torque of the motor cannot cope with the change of the paper feeding resistance. . That is, since the feed resistance is large when the paper thickness is large, the motor slows up and the generation of torque is delayed or insufficient torque occurs, and the paper feed tends to become unstable.

The present invention has been made in view of the above circumstances, and provides a sheet feeding device capable of variably controlling the generation of a torque of a motor in accordance with the sheet thickness of a sheet and effectively feeding the sheet. The purpose is to

[0008]

SUMMARY OF THE INVENTION According to the present invention, a rotary feed means for feeding a sheet, a motor for rotationally driving the rotary feed means, and a paper feed path upstream of the rotary feed means are provided. A paper thickness detecting means for detecting the thickness, a motor control means for controlling the operation of the motor, and a thicker the paper thickness of the paper detected by the paper thickness detecting means, the more the current flowing through the motor control means to the motor. And a current control means for increasing the electric current.

[0009]

According to the present invention, when the paper thickness detected by the paper thickness detecting means is thin, the current control means reduces the current flowing through the motor through the motor control means to perform slow-up start-up to reduce power consumption. .

On the other hand, when the paper thickness detected by the paper thickness detection means is thick, the current control means increases the current flowing to the motor through the motor control means to accelerate the slow-up start and increase the torque. , Even if the paper feed resistance is large, the paper can be fed stably.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an embodiment of the paper feeding apparatus of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a paper feed path, which is formed between upper and lower guide plates 2 and 3.

Window holes 2a and 3a are formed in the upper and lower guide plates 2 and 3, and a rotary feeding means 4 for feeding the paper in the paper feeding path 1 through the window holes 2a and 3a is arranged. The rotary feed means 4 is composed of a feed roller 5 and a pinch roller 6, the feed roller 5 is arranged so as to project from the lower window hole 3a into the paper feed path 1, and the pinch roller 6 feeds the paper through the upper window hole 2a. It is biased in a direction in which it projects into the path 1 and comes into pressure contact with the upper portion of the feed roller 5.

A timing pulley 7 is fixed to the rotary shaft of the feed roller 5, and a timing pulley 9 is fixed to the drive shaft of a stepping motor 8 arranged below the paper feed path 1. A timing belt 10 is stretched over. Then, by driving the stepping motor 8, the feed roller 5 is rotationally driven in the paper feed direction indicated by the arrow in the figure.

A paper thickness detecting means 11 is arranged upstream of the position of the feed roller 5 in the paper feed path 1. In this paper thickness detecting means 11, a reference guide member 12 is fixedly arranged below the paper feed path 1, and a sensor body 13 is arranged above the reference guide member 12 so as to face it.

As shown in FIG. 3, in the sensor body 13, a movable portion 15 is vertically movably fitted and housed in an inner lower portion of a cylindrical case 14, and a fixed portion 16 is fitted and fixed in an inner upper portion thereof so as to be movable. Part 15
A spring 17 that presses the movable portion 15 downward is arranged between the fixed portion 16 and the fixed portion 16. The movable portion 15 is provided with a hemispherical contactor 19 that comes into contact with the paper P on the lower surface of a boss 18 that projects downward from the lower surface of the case 14, and a magnet 20 is embedded on the upper surface. A magnetic force sensor 21 including a Hall element is embedded in the fixed portion 16 on the lower surface of the movable portion 15 facing the magnet 20.

Then, the amount of upward movement of the movable portion 15, that is, the distance L between the movable portion 15 and the fixed portion 16 changes according to the thickness of the paper P passing between the reference guide member 12 and the sensor body 13. Then, the magnetic force that the magnetic force sensor 21 receives from the magnet 20 changes, and the analog signal of the voltage corresponding to this magnetic force is output from the magnetic force sensor 21. For example, if the paper P is thick, an analog signal with a large voltage is output from the magnetic force sensor 21.

FIG. 1 shows a control circuit diagram of the stepping motor 8. The motor control means 31 inputs a motor phase signal pulse, sequentially supplies currents to the motor windings provided in the stator of the stepping motor 8 in multiple phases, and rotates the motor windings at a constant angle. Further, an operational amplifier 32 for amplifying a signal output from the magnetic force sensor 21 is connected to the output side of the magnetic force sensor 21 of the sensor body 13, and a base of a transistor 34 as a current control means is connected to the operational amplifier 32 via a resistor 33. It is connected. In the transistor 34, the current flowing between the collector and the emitter changes according to the magnitude of the current level of the signal applied to the base, and the stepping motor 8 from the current supply line connected via the resistor 35 through the motor control means 31. Control the current supplied to. That is, the higher the current level applied to the base of the transistor 34, the larger the current flowing between the collector and the emitter, and the stepping motor 8 through the motor control means 31.
The current flowing through it increases.

The paper thickness detecting means 11 is also used as a paper detecting means. The paper thickness detecting means 11 detects the paper P and a current flowing through the collector-emitter of the transistor 34 to the motor control means 31 is applied. In accordance with the change, the motor control unit 31 determines the sheet detection.

Next, the operation of this embodiment will be described.

The paper P is guided from the upstream side of the paper feed path 1, and the leading end of the paper P is the reference guide member 12 of the paper thickness detecting means 11.
The sensor body 13
The analog signal of the voltage output from the magnetic force sensor 21 becomes large, and this signal is amplified by the operational amplifier 32 and applied to the base of the transistor 34, and the operation of the transistor 34 causes a current to flow between the collector and the emitter, resulting in stepping. The motor 8 is started.

At this time, for example, when the paper P is thin, the analog signal of the voltage output from the magnetic force sensor 21 is small, so that the current flowing through the collector-emitter of the transistor 34 to the stepping motor 8 is small. As shown by the solid line in FIG. 4, the torque gradually increases as the stepping frequency rises after the start of activation, and a predetermined magnitude of torque is obtained when the predetermined stepping frequency m is reached. That is, the stepping motor 8 is started in slow up.

On the other hand, when the paper P is thick, the analog signal of the voltage output from the magnetic force sensor 21 is large, so that the current flowing through the collector-emitter of the transistor 34 to the stepping motor 8 is large, as shown in FIG. As indicated by the broken line, the torque increases rapidly as the stepping frequency rises after starting the operation, and a torque of a predetermined magnitude is obtained when the stepping frequency n lower than the stepping frequency m is reached. . That is, the slow-up start of the stepping motor 8 is accelerated and the torque is increased.

In this way, the stepping motor 8 is activated to rotationally drive the feed roller 5, and the feed roller 5
The paper P entering between the pinch roller 6 and the pinch roller 6 is nipped between the feed roller 5 and the pinch roller 6 and fed in the downstream direction of the paper feed path 1.

When the paper P is thin, the stepping motor 8 is started in slow-up.
Since the feeding resistance of the paper P is small, the feeding of the paper P is stable. When you start the slow-up like this,
Power consumption can be reduced.

On the other hand, when the paper P is thick, the slow-up start-up of the stepping motor 8 is accelerated and the torque is increased. Therefore, even if the feed resistance of the paper P is large, the feeding of the paper P is stable. There is.

As described above, by variably controlling the generation of the torque of the stepping motor 8 according to the paper thickness of the paper P, the paper P can be fed well.

The rotary feeding means 4 is not limited to the roller form, but may be a belt form in which a belt stretched between a plurality of pulleys faces the paper feed path 1.

[0029]

According to the present invention, the larger the paper thickness of the paper detected by the paper thickness detecting means, the larger the electric current flowing to the motor through the motor control means. Therefore, the paper thickness is thick and the feeding resistance is large. Even when it is large, the current flowing through the motor is increased to accelerate the slow-up start and increase the torque, so that the paper can be fed stably.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a paper feeding device of the present invention.

FIG. 2 is a sectional view of the above embodiment.

FIG. 3 is a side view for explaining the internal structure of the paper thickness detecting means of the above embodiment.

FIG. 4 is a motor characteristic diagram of the above embodiment.

[Explanation of symbols]

 4 rotation feed means 8 motor 11 paper thickness detection means 31 motor control means 34 transistor as current control means P paper

Claims (1)

[Claims] 1. A rotary feed means for feeding a sheet, a motor for rotationally driving the rotary feed means, and a paper thickness detection means provided upstream of the rotary feed means in a paper feed path for detecting the paper thickness of the paper. A motor control means for controlling the operation of the motor, and a current control means for increasing the current flowing through the motor through the motor control means as the paper thickness of the paper detected by the paper thickness detection means increases. A paper feeding device characterized in that