JPS6127852A - Paper end detector of printer - Google Patents

Abstract

PURPOSE:To improve the accuracy of paper end detection by detecting that paper is not supplied to a print drum from a paper feed portion in a regular timing during printing by operation of a latch circuit. CONSTITUTION:When a paper feed sensor 8 does not detect paper to be supplied from a paper feed portion 7 to a print drum, the count number of a counter 2 is added. When the count number comes to a value ''5'' set by a setting device 3, while paper is not supplied, a comparator 4 outputs a coincidence signal, which is latched by a latch circuit 5. The latch circuit 5 outputs a display signal to a paper end condition display device 6, and the paper end condition display device 6 displays that paper is out. Simultaneously, a paper feed stop sig nal is outputted to the paper feed portion 7 to stop the paper feed operation at the paper feed portion 7.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a paper-out detection device for a printing press, and more specifically, to a paper-out detection device for a printing press, and more particularly, to a paper-out detection device for a printing press, and more particularly, to a paper-out detection device for a printing press, and more specifically, a paper-out detection device for a printing press. The present invention relates to a paper-out detection device for a printing press that can accurately indicate that there is no paper in a paper feed section.

(Prior Art) A printing machine is provided with a paper-out detection device to detect and display a state in which there is no paper in a paper feed section. When it is detected that the paper feed section is out of paper, it is necessary to immediately stop the printing press and replenish paper.

Conventionally, a paper-out detection device for detecting a state in which there is no paper in a paper feed section has been performed by detecting the position of a paper feed table using a micro-sinch. For example, as shown in FIG. 2, in a mechanism that feeds paper 100 by suctioning and holding it with a sucker 101, the topmost paper 100 on the paper feed table 102 must be at a fixed position, and the paper 100 The paper feed table 102 is raised every time the paper is fed by one foot.

Therefore, the position of the paper feed tray 102 when the paper 100 runs out is detected by the microswitch 103, and it is determined that the paper 100 runs out.

(Problems to be Solved by the Invention) However, this apparatus has low detection accuracy, and it is difficult to adjust the microsinch to operate after the last sheet has been fed. For this reason, there is a problem in that it is determined that there is no paper even though it is present, or that there is paper when there is no paper.

The present invention improves the accuracy of out-of-paper detection by detecting that paper is not being fed from the paper feed section to the printing cylinder at the correct timing during printing, and determining whether the paper feed section is out of paper. The object of the present invention is to provide a paper-out detection device for a printing press.

(Means for Solving the Problems) In order to solve the above problems, a paper out detection device for a printing press according to the present invention includes a timing pulse generator that generates timing pulses synchronized with the rotation of the printing cylinder during printing. , a paper feed detector that detects passage of paper from the paper feed section to the printing cylinder and outputs a paper feed detection signal; and a paper feed detection signal of the paper feed detector that counts and outputs the timing pulses. a counter that is reset by the setting device; a setting device that sets a reference value for determining that there is no paper in the paper feed section; and a comparator that outputs an output when the output from the counter becomes equal to the output from the setting device. , a latch circuit that latches the output of the comparator to output a display signal and also outputs a paper feed stop signal to the paper feed section; and a display signal from the latch circuit that indicates that there is no paper in the paper feed section. It consists of a display device.

According to the above structure, the object of the present invention can be completely achieved.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a paper-out detection device for a printing press according to the present invention.

The timing pulse generator 1 is for generating timing pulses corresponding to the rotation of the printing cylinder, and generates timing pulses synchronized with the slits of a rotating disk provided on the printing cylinder. The timing pulse generated by the timing pulse generator 1 is sent to the clock terminal CL of the counter 2.
It is connected to the.

The paper feed sensor 8 is for detecting that paper is being fed and outputting a paper feed detection signal.

The paper feed sensor 8 is provided on the paper supply path from the paper feed section 7 to the printing cylinder. The output of the paper feed sensor 8 is an OR circuit 10. Counter 2 via one shot multi-bye break 11
is connected to the reset terminal R of. The output of the manual reset button 9 is connected to the other input terminal of the OR circuit 10. The counter 2 is reset by a paper feed detection signal from the paper feed sensor 8 or a reset signal from the one-motion reset button 9.

The counter 2 counts and outputs the timing pulses generated by the timing pulse generator 1 as a rotation signal of the printing cylinder. The counter 2 is reset by a paper feed detection signal from the paper feed sensor 3. The counter 2 counts the number of times the printing cylinder rotates without being fed paper.

The outputs of the counter 2 and the setting device 3 are connected to the comparator 4 . A comparator 4 compares the output of the counter 2 and the output of the setter 3, and outputs a match signal to the latch circuit 5 when they match.

The setting device 3 is used to set a reference value for determining that there is no paper in the paper feed section. The setting value of this setting device 3 is “
5", the comparator 4 outputs a coincidence signal when the paper feed sensor 8 does not detect any paper feed during the printing cylinder rotation 5 times. By setting the set value to "5", This prevents the comparator 4 from erroneously outputting a coincidence signal when an accident occurs in which paper cannot be fed properly although it is not a paper jam during paper feeding adjustment.

If this accident occurs five times in a row, it is considered that it is necessary to perform the paper feed adjustment again, so it is possible to stop the paper feed in the same way as when there is no paper, and restart it after readjusting the paper feed.

The output of the latch circuit 5 is branched, and one side is connected to the paper out status indicator 6 and the other side is connected to the paper feed section 7. The latch circuit 5 is a circuit that latches the output of the comparator 4 and outputs a display signal, and also outputs a paper feed stop signal to the paper feed section 7.

The paper out status indicator 6 is for displaying that there is no paper when the latch circuit 5 is outputting. for example,
The alarm may be displayed visually using an LED or the like, or may be audibly alarmed using a buzzer or the like. Of course, these means can also be used together.

The paper feeding section 7 stops the paper feeding operation in response to a paper feeding stop signal from the latch circuit 5.

The manual reset button 9 is connected to the reset node terminal R of the latch circuit 5.
and the OR circuit 10, and the counter 2. This is for resetting the latch circuit 4.

Next, the operation of this embodiment will be explained.

- The timing pulse generator 1 generates timing pulses synchronized with the rotation of the printing cylinder, and the counter 2 counts the number of pulses. If the paper feed sensor 8 detects that paper is being fed, the counter 2 is reset. If paper is not detected by the paper feed sensor 8 and the counter 2 is not reset, the count of the counter 2 continues to be incremented.

When the count reaches the value "5" set by the setter 3 without paper being fed, the comparator 4 outputs a coincidence signal, and the latch circuit 5 latches the output. The latch circuit 5 outputs a display signal to the paper out status indicator 6, and the paper out status indicator 6 displays that there is no paper. At the same time, a paper feeding stop signal is output to the paper feeding section 7 to stop the paper feeding operation in the paper feeding section 7. By pressing manual reset button 9, counter 2. The latch circuit 5 is reset, the display on the paper out status indicator 6 is stopped, and the printing operation can be started again.

In the above embodiment, there is no special restriction on the timing of the timing sensor, and if the timing sensor is used for another purpose, it can be used in common. In particular, such timing sensors are always used in automated printing presses that use microcomputers, so the counters and comparators used in this device can be replaced with additional components by using the same functions in the CPU. It is also possible to practice the invention without it.

(Effects of the Invention) As described in detail above, according to the present invention, it is detected that the paper is not being fed from the paper feed section to the printing cylinder at the regular timing during printing, so that the paper is not fed to the paper feed section at the proper timing. Absence can be accurately detected.

Another advantage is that an abnormality can be detected even when a paper jam occurs due to poor paper feeding.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a paper out detection device for a printing press according to the present invention. FIG. 2 is a diagram showing a conventional paper out detection device.

Claims (1)

[Claims] a timing pulse generator that generates a timing pulse synchronized with the rotation of the print cylinder during printing; a paper feed detector that detects passage of paper from a paper feed unit to the print cylinder and outputs a paper feed detection signal; counting and outputting the timing pulses;
a counter that is reset by a paper feed detection signal from the paper feed detector; a setting device that sets a reference value for determining that there is no paper in the paper feeding section; and an output from the counter that is output from the setting device. a comparator that outputs an output when it becomes equal to A paper out detection device for a printing press, comprising an indicator that indicates that there is no paper in the paper feed section.