JPH0749195B2 - Paper cutting device - Google Patents

Description

The present invention relates to a copying machine, a facsimile, a word processor,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet cutting device for cutting a long recording sheet wound in a roll into a fixed length in a computer terminal and similar devices.

(Prior Art) Conventionally, when cutting a long recording paper or the like wound in a roll into a certain length, it is often the case that the recording paper is temporarily stopped and then cut by a rotary cutter or the like. In order to shorten the processing time, the recording paper has been cut using a rotary cutter during continuous feeding without stopping. Such a rotary cutter type paper cutting device is composed of a pair of fixed blades and rotary blades, and a cutter that cuts an object by rotating the rotary blade once, an electromagnetic clutch that transmits a rotational force to the cutter, and the like. It is equipped with a transmission mechanism, a detector that detects the rotation of the cutter, a power source such as a motor that conveys and cuts the paper, a control circuit that controls these movements, and an electromagnetic brake that stops the rotary blade. Signal, the electromagnetic clutch operates, and the rotational force from the power source is transmitted to the rotary blade of the cutter to cut the sheet being conveyed. When the rotary blade reaches the stop position after cutting the paper, a signal is output from the rotation detector, the electromagnetic clutch is turned off, and the rotary blade is stopped by the electromagnetic brake.

FIG. 4 shows a conventional example, in which 10 'is a slit disk having a notch at one place, and 16 is an electromagnetic brake provided coaxially with the electromagnetic clutch 12. In this conventional example, when the rotary blade 1 operates, the electromagnetic brake 16 is turned off by a signal from the device control unit, and at the same time, the electromagnetic clutch 12 is turned on and the rotary blade starts to rotate. Then, when the rotary blade 1 comes to a stopped state, the signal of the detector 11 is turned on, and the signal from the device control section turns off the electromagnetic clutch 12 and simultaneously turns on the electromagnetic brake 16 to stop the rotary blade 1.

(Problems to be solved by the invention) However, in the above-mentioned conventional rotary cutter type sheet cutting device, since the stop position and the cutting position of the rotary blade are separated by an angle, the rotary blade is rotated by the cutting signal. There is a time delay between the start of cutting and the start of cutting.
Therefore, when cutting the paper at a fixed position, it is necessary to make the time from the start of rotation of the rotary blade to the start of cutting constant every time. That is, it is necessary to make the stop position of the rotary blade constant every time, and in the above-mentioned conventional sheet cutting device, in order to make the stop position of the rotary blade constant, another electromagnetic brake of the electromagnetic clutch is provided in the transmission mechanism. There is. Therefore, the structure is complicated, and the cutting length of the paper is not constant due to the difficulty of setting the timing lag when turning on the electromagnetic clutch after turning off the electromagnetic brake and the variation in the operating time of the electromagnetic clutch / brake. There was a problem.

The present invention is to solve such a conventional problem, and to provide a stable sheet cutting device having a simple structure that does not require a constant stop position of a rotary blade using an electromagnetic brake. The purpose is.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention detects rotation by outputting the number of pulses corresponding to the rotation angle of the rotary blade coaxially with the rotary blade of the cutter after completion of cutting the paper. A clutch is provided, the clutch is turned off by the first pulse signal, and the stop position of the rotary blade is detected by the number of pulses. And the operation timing of the next rotary blade is
By controlling according to the magnitude of the pulse number, the cutting length of the paper is made constant even if the stop position of the rotary blade is displaced.

That is, a rotary cutter that cuts by sandwiching a sheet between a fixed blade and a rotary blade, and a drive source that rotates the rotary blade,
In a paper cutting device that automatically cuts a long continuous paper consisting of a clutch that transmits the power of the drive source to the rotary blade to a constant length in a transport state, a signal for turning off the clutch and the rotary blade And a rotary blade drive start signal control circuit capable of changing the time according to the stop position obtained by the detector.

(Operation) The present invention has the following operations due to the above configuration. That is, the rotary blade operates and the paper is cut by the cutting signal. When the cutting of the paper is completed, a pulse signal is output from the rotation detector provided coaxially with the rotary blade, and the electromagnetic clutch that transmits power to the rotary blade by the first signal from this rotation detector is turned off. Then, the rotary blade stops after a little overrun.

Since the number of pulses from the rotation detector and the rotation angle of the rotary blade are in a proportional relationship, the stop position of the rotary blade can be detected by the number of pulses from the rotation detector.

When the cutter is operated in the next sequence, the number of pulses from the rotation detector and the reference pulse number in the previous sequence are calculated and used as the operation timing of the electromagnetic clutch for transmitting power to the rotary blade of the cutter. That is, when the number of pulses from the rotation detector is larger than the reference number of pulses,
The start of the rotary blade is delayed, and when it is small, it is controlled to be advanced. In this way, the timing of starting the cutting of the paper becomes constant regardless of the stop position of the rotary blade, so that the uniform paper length can be obtained with a simple structure.

(Embodiment) FIG. 1 shows the configuration of an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a rotary blade, which is rotatably supported by the cutter body 7. Fixed blade 2 has fulcrums 5,6
It is rotatably supported by. Fixed blade 2 is
The spring members 3 and 4 constantly press the rotary blade 1. The rotary blade 1 uses the fixed blade 2 only when cutting the paper 15.
It is designed to come into contact with. Shaft 8 at one end of rotary blade 1
Is attached to the shaft of the electromagnetic clutch 12 via a joint 9. A slit disk 10 is attached to the joint 9, and a detector 11 having a light emitting diode and a phototransistor as a pair is arranged at an opposing position. The input side of the electromagnetic clutch 12 is connected via a toothed belt 13 to a motor 14 which is a rotational power source.

Next, the operation of the present invention will be described with reference to FIGS. 2 and 3 showing the relative positional relationship among the rotary blade 1, the fixed blade 2, the slit disk 10 and the detector 11. FIG. 2 shows the stop position of the rotary blade before cutting the paper. Paper 15 is motor 14
Is continuously conveyed by a sheet conveying section (not shown). A disconnection signal is output from a control circuit (not shown), the electromagnetic clutch 12 is turned on, and the rotary blade 1 rotates in the arrow direction. The rotary blade 1 cuts the sheet 15 that is adhered to and intervenes with the fixed blade 2 and further rotates. Since the peripheral speed of the rotary blade 1 is set to be several times higher than the conveying speed of the paper 15,
It is possible to cut the sheet 15 while it is being conveyed.

FIG. 3 shows a state in which the sheet 15 is cut by the rotary blade 1 and the fixed blade 2 and the rotary blade 1 is slightly rotated. When the rotary blade 1 further rotates in the arrow direction from the state of FIG. 3, the detector 11 outputs a pulsed signal. The pulse signal from the detector 11 is
The signal is sent to the control circuit, and the control circuit receives the first pulse signal and issues a signal to turn off the electromagnetic clutch 12, and at the same time, starts counting the pulse signal. Electromagnetic clutch
When 12 is turned off, rotary blade 1 slightly overruns and stops. Counting of the pulse signal from the detector 11 is continued until the rotary blade 1 stops, and after the stop, the count number is recorded and held in the control circuit.

In the next sequence, the count number in the previous sequence is compared and calculated with the reference pulse number, and the timing to turn on the electromagnetic clutch is the plus pulse number when the calculation result is positive (when the count pulse number is larger than the reference pulse). Is controlled to be delayed by a time proportional to, and in the case of a minus, the control is controlled to be advanced by a time proportional to the number of minus pulses.

As described above, according to the above-described embodiment, the stop position of the rotary blade 1 is detected by the number of pulse signals from the detector 11, and the operation timing of the rotary blade in the next sequence is controlled by the detection result, Even if the stop position of the rotary blade 1 is not constant every time, the paper 15 has an advantage of being cut into a constant length every time. Further, in the above embodiment, when the rotary blade 1 and the fixed blade 2 are in contact with each other and the sheet 15 cannot be conveyed, the slit circle is shaped so that the signal from the detector 11 is always off. The plate 10 is formed. Therefore, while the signal from the detector 11 is always off, the rotary blade 1
Since it is possible to detect an abnormal state in which the paper is stopped, it is possible to prevent jamming of the paper 15 in advance.

In the above embodiment, the slit 11 of the slit disk 10 is a detector 11 having a pair of a light emitting diode and a phototransistor.
However, instead of the slit disc 10, a detection method using a magnetic drum and a reed switch or a Hall element can be used. Further, in the above-described embodiment, the control signal is obtained by only one detector 11, but two detectors, a detector for detecting the rotation of the rotary blade 1 and a detector for detecting the phase angle of the rotary blade 1, are provided. A method of obtaining a control signal by using it can also be considered. At this time, the slit disk for detecting the rotation of the rotary blade 1 can be provided with slits on the entire circumference of the disk. Further, instead of the slit disc method, a method of detecting the rotation of the rotary blade 1 using a frequency generator including a protrusion made of a magnetic material around the disc and a detection coil for detecting the movement of the protrusion is also considered. To be

(Effects of the Invention) As apparent from the above-described embodiment, the present invention detects the stop position of the rotary blade 1 and controls the operation timing of the next sequence, so that the rotary blade has a simple structure and is 1 has an advantage that the cut length of the paper can be made constant at all times even if the stop position varies.

Further, according to the present invention, since a signal for turning off the clutch and a rotary blade drive start signal capable of changing the time according to the stop position of the rotary blade can be obtained with one detector, an inexpensive sheet cutting device can be obtained. It has the advantage of being able to.

[Brief description of drawings]

FIG. 1 is a perspective view of a sheet cutting device according to an embodiment of the present invention, FIGS. 2 and 3 are schematic views showing relative positions of a rotary blade and a slit disk, and FIG. The blade is stopped, and FIG. 3 shows the state immediately after cutting the sheet. FIG. 4 is a perspective view of a conventional sheet cutting device. 1 ... Rotating blade, 2 ... Fixed blade, 3,4 ... Spring member, 5,6 ...
… Support point, 7 …… Cutter body, 9 …… Fitting, 10,10 ′ ……
Slit disk, 11 …… Detector, 12 …… Electromagnetic clutch, 13
…… Toothed belt, 14 …… Motor, 15 …… Paper, 16 …… Electromagnetic brake.

Claims (4)

[Claims] 1. A rotary cutter for sandwiching and cutting a sheet between a fixed blade and a rotary blade, a drive source for rotating the rotary blade, and a clutch for transmitting the power of the drive source to the rotary blade. In a paper cutting device that automatically cuts long continuous paper into a certain length while being conveyed,
Paper cutting comprising a detector that obtains a signal for setting F and a signal that detects the stop position of the rotary blade, and a rotary blade drive start signal control circuit that can change the time according to the stop position obtained by the detector apparatus. 2. The detector comprises a disc having a plurality of slits coaxial with a rotary blade and electricity, magnetism, light, or a combination thereof. (1) A paper cutting device described on page. 3. The paper according to claim 1, wherein the detector comprises a disc having a plurality of protrusions made of a magnetic material coaxial with the rotary blade and a detection coil. Cutting device. 4. The sheet cutting device according to claim 1, wherein the signal for turning off the clutch is the first signal from a disk coaxial with the rotary blade.