JPH04308754A - Method and apparatus for detecting erroneous mounting of press-plate - Google Patents

Abstract

PURPOSE:To prevent that printing treatment once started is made invalid by preliminarily displaying inherent data on a press-plate at a predetermined posi tion and judging whether or not a printing plate is proper by reading said data at a predetermined time before the start of printing when the press-plate is mounted on a plate cylinder. CONSTITUTION:A plate cylinder 1 is supported on a printing apparatus centering around a rotary shaft 2 and a notch is formed to a part of the peripheral surface of the plate cylinder 1 in the longitudinal direction of said cylinder to be set to the mounting part 3 of a printing plate. A read sensor 6 is arranged at the position opposed to one end surface 4a of the plate cylinder 1 when said end surface 4a reaches a predetermined position and the inherent plate data 7 displayed on the second fold part 5b of a press-plate 5 is read by the read sensor 6. For example, the plate data 7 is composed of a bar code and constituted of data such as a date to be printed or the number of pages so as to make it possible to specify the image content possessed by the press plate concerned. It is judged whether or not the press-plate 5 is proper on the basis of the read plate data to prevent erroneous mounting.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to a printing method such as offset printing or letterpress printing in which a printing plate is attached to a plate cylinder and printing processing is carried out, and in particular a printing method that detects the suitability of a printing plate attached to a plate cylinder. Concerning a method for detecting incorrect mounting of a plate.

The present invention also relates to an erroneous mounting detection device to which the method for detecting erroneous printing plate mounting is applied.

0003

[Prior Art] In printing apparatuses such as offset printing and letterpress printing, in which a printing plate is attached to a plate cylinder and printing processing is carried out,
There was no device designed to detect the suitability of the printing plate mounted on the plate cylinder. For this reason, in printing methods using conventional printing devices, the operator visually inspects the printed paper surface during the printing process and determines whether the printing plate mounted on the plate cylinder is appropriate based on the printed content. I was trying to judge.

0004

[Problems to be Solved by the Invention] However, in the above-mentioned conventional printing method, errors in mounting the printing plate on the plate cylinder are discovered after the printing process has started, and if an operator discovers this, the operation cannot be carried out. It is necessary to temporarily stop the printing device inside the printer, reinstall the appropriate printing plate on the plate cylinder, and then restart the printing process, which causes time loss in the printing process.
There was a problem that led to longer work hours. In addition, since loading errors are discovered after the printing process, even if they are discovered, a large amount of wasted paper is generated, leading to an increase in printing costs, and if it is not discovered, the wrong paper is transported as is. A problem arises. For example, in printing processes such as newspaper printing, where several to ten or more systems are installed per factory, and a single system is loaded with hundreds of printing plates, this is especially true. It is easy to erroneously mount the plate, causing major problems such as the delay in working time and the occurrence of paper waste, and the possibility of overlooking mistakes increases.

An object of the present invention is to read data written on the printing plate in advance at a predetermined time after the printing plate is mounted on the plate cylinder and before starting printing, and to determine whether or not the mounted printing plate is suitable based on this data. An object of the present invention is to provide a method for detecting incorrect mounting of a printing plate, which can prevent delays in working time, occurrence of paper waste, and transportation of incorrect printed matter due to incorrect mounting of printing plates.

Another object of the present invention is to provide an erroneous mounting detection device to which this method for detecting erroneous printing plate mounting is applied.

[0007]

[Means for Solving the Problem] The method for detecting incorrect mounting of a printing plate according to claim 1 is such that unique data is written in advance at a predetermined position on the printing plate, and the printing plate is printed after the printing plate is mounted on the plate cylinder. It is characterized in that the data is read at a predetermined time before the start of the process, and based on this data, the suitability of the installed printing plate is determined.

[0008] In the method for detecting erroneous mounting of a printing plate, the predetermined time is a time when the plate cylinder rotates at a low speed before printing.

In the method for detecting erroneous mounting of a printing plate, the predetermined position is a second folded portion of the printing plate.

[0010] In the method for detecting incorrect mounting of a printing plate, the predetermined position is the back side of the printing plate.

[0011] The incorrect mounting detection device according to claim 5 is provided with a reading sensor facing the second folded portion of the printing plate mounted on the plate cylinder at a predetermined position on the plate cylinder, It is characterized by reading the written data and determining the suitability of the printing plate mounted on the plate cylinder based on this data.

[0012] The incorrect mounting detection device according to claim 6 is provided with a reading sensor exposed at a predetermined position on the circumferential surface of the plate cylinder, reads data written on the back side of the printing plate, and based on this data, the plate cylinder is It is characterized by determining the suitability of the printing plate mounted on the machine.

[0013]

[Operation] In the method for detecting incorrect mounting of a printing plate as set forth in claim 1, unique data written in advance on the printing plate mounted on the plate cylinder is read before printing starts, and based on this data, the printing plate is The suitability of the test will be determined. Therefore, the suitability of the printing plate is automatically determined before printing starts, the printing process once started is not invalidated, and the delay in printing process time and the occurrence of paper waste are prevented. .

[0014] In the method for detecting erroneous mounting of a printing plate, data written on the printing plate is read while the plate cylinder on which the printing plate is mounted rotates at a low speed. Therefore, the data specific to the printing plate can be read accurately.

[0015] In the method for detecting incorrect mounting of a printing plate, unique data is written on the second fold of the printing plate. Therefore, part of the image range of the printing plate is not used as the data notation range, and unnecessary images are not printed on the paper. Further, the data is not easily stained with ink or the like and becomes unreadable.

[0016] In the method for detecting erroneous mounting of a printing plate according to claim 4, unique data is written on the back side of the printing plate. Therefore, data is completely prevented from becoming unreadable due to staining with ink or the like.

In the incorrect attachment detection device according to claim 5,
A second folded portion of the printing plate mounted on the plate cylinder faces the reading sensor at a predetermined position on the plate cylinder. Therefore, when the plate cylinder is moved by a predetermined amount after the printing plate is attached, the data written on the second fold of the printing plate is read by the reading sensor.

[0018] In the incorrect attachment detection device according to claim 6,
The back side of the printing plate mounted on the plate cylinder faces a reading sensor exposed on the circumferential surface of the plate cylinder. Therefore, the data written on the back side of the printing plate mounted on the plate cylinder is read by a reading sensor provided exposed on the circumferential surface of the plate cylinder.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a schematic configuration of the main parts of a printing apparatus to which a method for detecting erroneous mounting of a printing plate according to an embodiment of the present invention is applied. A plate cylinder 1 is supported by a printing device around a rotating shaft 2. A notch is formed in a part of the circumferential surface of this plate cylinder 1 in the longitudinal direction, and this part is a mounting part 3 for the printing plate.
It is being done. That is, after attaching one end of the printing plate 5 to one end surface 4a formed on the mounting portion 3 as shown in FIG.
is rotated to wrap the printing plate 5 around the circumferential surface of the plate cylinder 1. After this, the other end of the printing plate 5 is fixed to the other end surface 4b.

As shown in FIG. 1, one end surface 4 of the plate cylinder 1
A reading sensor 6 is installed so as to face this end surface 4a when a reaches a predetermined position. This reading sensor 6 reads unique plate data 7 written on the printing plate 5. This plate data 7 is written on the second fold section 5b of the printing plate 5. This plate data 7 is, for example, barcode data, and is composed of data such as the date and number of pages to be printed, and allows the image content of the printing plate to be specified.

FIG. 3 is a diagram showing how the main parts of the printing plate are attached in the printing apparatus. The printing plate 5 is on the back side 4c of the plate cylinder 1
The first folded portion 5a of the printing plate 5 is placed opposite to the first folded portion 5a of the printing plate 5, the back side of the second folded portion 5b is placed opposite to one end surface 4a of the plate cylinder 1, and the back surface of the image portion 5c of the printing plate 5 is placed on the circumferential surface of the plate cylinder 1. to face each other. As a result, when one end surface 4a of the plate cylinder 1 is located at a predetermined position, the plate data 7 written on the second folded portion 5b of the printing plate 5 faces the reading sensor 6.

Note that by providing a shutter on the reading sensor 6 and opening this shutter at the timing of reading the plate data 7, the reading sensor 6 is prevented from being soiled with ink, etc., and the plate data 7 can be read accurately at all times. It may be possible to do so.

FIG. 4 is a block diagram of the main parts of the control section of the printing apparatus. A reading sensor 6, a motor driver 18, a key controller 19, and a display driver 20 are connected to the CPU 11 via interface circuits 14 to 17.
is connected. The motor driver 18 is the CPU 11
The motor 21 is driven based on drive data output from the motor. This motor 21 is connected to the plate cylinder 1 via a drive mechanism (not shown).
Rotate.

A key panel 22 provided at the operating section of the device is connected to the key controller 19. This key panel 22 includes, for example, a printing switch 24 for instructing the start of printing processing, a printing switch 24 for instructing the start of printing processing, and a printing switch 24 for instructing the printing plate 5 to be mounted on the printing cylinder 1.
Fine movement switch 2 that is operated when rotating the
5 etc. are provided. The key controller 19 inputs data to the CPU 11 via the interface 16 in accordance with the switches operated on the key panel 22.

A display 23 is connected to the display driver 20 . This display 23 is provided in the operation section of the printing apparatus together with the key panel 22, and displays messages to the operator. The display driver 20 is a CPU
The display device 23 is driven based on the display data output from the display device 11.

The CPU 11 centrally controls the input/output devices described above according to a program written in the ROM 12 in advance. Data input and output during this period is stored in a predetermined memory area of the RAM 13. For example, memory area M
Setting data to be compared with plate data written on the printing plate 5 is stored in A1. This setting data is key panel 2
The initial value is the value inputted in advance by the key operation in step 2, and the data is updated every time the printing plate is replaced.

FIG. 5 is a flowchart showing the processing procedure of the control section. The CPU 11 reads switch operations on the key panel 22 (n1) and performs processing according to the operated switch. When the print switch 24 is operated, the motor 21 is driven (n2, n3), and when one end surface 4a of the plate cylinder 1 reaches a predetermined reading position after driving the motor 21, the plate data is read using the reading sensor 6. Read (n
4, n5). The amount of rotation of the motor 21 is detected by a sensor not shown, and n is determined according to the detection result of this sensor.
The reading timing in step 5 is determined.

Next, the setting data stored in the memory area MA1 of the RAM 13 is read out (n6), and the version data and the setting data are compared. If both data match in this comparison, update the settings data and perform RA.
Store in memory area MA1 of M13 (n7, n8),
The paper is fed and a predetermined amount of printing is executed (n9). On the other hand, if the plate data and the setting data do not match, the motor 21 is stopped (n7→n10), and the display 23 indicates that the printing plate is incorrectly installed.

Through the above processing, the plate data written on the second fold portion 5b of the printing plate 5 mounted on the plate cylinder 1 is read and compared with the data stored in the control section. In this comparison, print processing is executed only if the two match, and if they do not match, print processing is not started.

[0030] Also, by processing n3 to n5, motor 2
The plate data is read when the plate cylinder 1 reaches the reading position for the first time after being driven. When the printing plate is attached, the plate cylinder rotates at a low speed because it is manually rotated, and after the plate is attached, the rotation gradually increases until printing starts. Therefore, when the plate cylinder 1 reaches the reading position for the first time after the motor 21 starts driving, it is still rotating at a sufficiently low speed, and the plate data can be easily read by the reading sensor 6. Also,
Since the plate data 7 is written on the second fold 5b of the printing plate 5, it is not easily stained by ink or the like.

FIG. 6 is a perspective view showing a plate cylinder of a printing apparatus according to another embodiment of the present invention. A window 52 is formed in a part of the plate cylinder 51, and a reading sensor 6 is installed in this window 52.
The reading surface of No. 1 is exposed. In this way, by forming a reading surface for reading plate data on the circumferential surface of the plate cylinder 51 and marking the plate data on the part opposite to this reading position on the back side of the printing plate, the plate data can be read by the reading sensor 61. be able to.

With this configuration, the relative positional relationship between the reading sensor 61 and the plate data does not change even when the plate cylinder 51 rotates, and the plate data can always be read accurately regardless of the rotation state of the plate cylinder 1. can be done. Furthermore, since the plate data is written on the back side of the printing plate, it is never stained by ink or the like, and it is possible to completely prevent poor reading of the plate data.

[0033] In the above embodiment, a printing apparatus equipped with a detection means for reading plate data was exemplified.
This detection means may be constructed separately as an erroneous attachment detection device so that it can be retrofitted to an existing printing device. In this case, the reading timing of the plate data can be set on the detection device side based on the rotation signal input from the motor drive section of the printing device.

[0034]

Effects of the Invention According to the method for detecting incorrect mounting of a printing plate as set forth in claim 1, it is possible to automatically determine the suitability of the printing plate mounted on the plate cylinder before starting the printing process, and once the printing process is started, The printing process that has been performed will not be invalidated, and it is possible to prevent the printing process from taking a long time, generating a large amount of waste paper, and transporting erroneous printed matter. Furthermore, there is no need for the operator to check the paper surface after the start of the printing process, which has the advantage of saving labor for the operator.

According to the method for detecting erroneous mounting of a printing plate, the data written on the printing plate can be accurately read, and erroneous mounting of a printing plate can be reliably detected.

[0036] According to the method for detecting incorrect mounting of a printing plate according to claim 3, since data is written on the second fold of the printing plate, which is less likely to be soiled by ink, etc., data reading errors may occur. This has the advantage of preventing the occurrence of

[0037] According to the method for detecting incorrect mounting of a printing plate as described in claim 4, since the data is written on the back side of the printing plate, it is possible to completely prevent poor reading due to contamination with ink, etc. The relative positional relationship with the data does not change,
Data can always be read accurately regardless of the rotational state of the plate cylinder.

According to the erroneous mounting detection device according to claim 5, the data written on the second fold of the printing plate is read by the reading sensor after the printing plate is mounted on the plate cylinder and before printing starts. Can be done.

[0039] According to the erroneous mounting detection device described in claim 6, the data written on the back side of the printing plate can be accurately read by the reading sensor provided exposed on the circumferential surface of the plate cylinder.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of a main part of a printing apparatus to which a method for detecting incorrect mounting of a printing plate according to an embodiment of the present invention is applied.

FIG. 2 is a perspective view showing a state in which a printing plate is attached to a plate cylinder in the printing apparatus.

FIG. 3 is an enlarged view of essential parts showing how a printing plate is attached to a plate cylinder in the printing apparatus.

FIG. 4 is a block diagram of a control section of the printing apparatus.

FIG. 5 is a flowchart showing a processing procedure of a control unit of the printing apparatus.

FIG. 6 is a perspective view showing a plate cylinder of the printing apparatus according to the invention set forth in claim 6.

[Explanation of symbols]

1-Print cylinder 5-Printing plate 5b-Second folding part 6-Reading sensor 7-edition data

Claims (6)

[Claims] Claim 1: Unique data is recorded in advance at a predetermined position on the printing plate, and the data is read at a predetermined time before printing starts after the printing plate is mounted on the plate cylinder, and the mounted printing plate is determined based on this data. A method for detecting incorrect mounting of a printing plate, characterized by determining suitability of the plate. 2. The method for detecting incorrect mounting of a printing plate according to claim 1, wherein the predetermined time is a time when the plate cylinder rotates at a low speed before printing. 3. The method for detecting incorrect mounting of a printing plate according to claim 1, wherein the predetermined position is a second folded portion of the printing plate. 4. Claim 1, wherein the predetermined position is the back side of the printing plate.
4. The method for detecting incorrect mounting of a printing plate according to any one of items 3 to 3. 5. A reading sensor is provided opposite to the second folding portion of the printing plate mounted on the printing plate at a predetermined rotational position of the printing plate, and
An erroneous mounting detection device characterized by reading data written on a folding part and determining whether or not a printing plate mounted on a plate cylinder is appropriate based on this data. 6. A reading sensor is provided exposed at a predetermined position on the circumferential surface of the printing plate to read data written on the back side of the printing plate,
An erroneous mounting detection device that determines the suitability of a printing plate mounted on a plate cylinder based on this data.