JPH01139266A - Bar code printing press - Google Patents

Abstract

PURPOSE:To enable the quantity of bar code on a corrugated cardboard sheet travelling at high speed to be checked on a printing press using a simple physical means by rotating a detector installed on a roll which is rotated at the same number of rotations as that of a plate cylinder, to be driven, synchronized to the travelling speed of the bar code. CONSTITUTION:A detector 8 is installed on the periphery of a detection roll 7 which is rotated at the same number of rotations as that of a plate cylinder 3 in close proximity to a printing part checks the printing quality of bar code, that is, the thickness of a bar and space, variable density of color, scar, dirt, arrangement, etc. The peripheral speed VB of the detection end of the detector 8 is driven by rotation with the detection roll 7, synchronized to the moving speed VB of the bar code 6B printed on a corrugated cardboard sheet being fed so that the peripheral speed VB of said detection end is timed to said moving speed VB of bar code. The time interval R.theta/VB is created for the detector 8 and printing bar code 6B in such a manner that their relative speed becomes almost zero. Consequently, the detector 8 and the printing bar code 6B can be detected almost in a standstill condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a barcode 9 printing device that prints a predetermined barcode on the outer surface of a corrugated cardboard sheet for box production.

(Prior Art) A barcode is a code consisting of a combination of vertical lines of different thickness and spacing, and is printed on the label, packaging, or storage box of an item, and is used to convey information necessary for logistics such as the content price of the item. This code is used to display the code and read it optically as needed to help streamline logistics, etc.
Currently, it is widely used in many industries and industries in many aspects of logistics systems.

By the way, the layout of the Noku-coat 9 is determined by the thickness and spacing of the lines, so if it is not printed accurately, it has no value as a code.For example, if there is a risk of misreading due to poor printing accuracy, Far from being streamlined, on the contrary, post-processing of misreadings takes up a lot of manpower, which not only does not produce the desired effect, but also can endanger human lives in the case of misreadings of medicines, etc.

Therefore, high precision and high reliability are required for printing of the code 1.

For general commercial printing on corrugated cardboard sheets, letterpress printing presses are often used, particularly flexographic printing presses that use rubber-lined printing plates and quick-drying liquid inks. Here, one example of its basic configuration will be explained based on FIG. 3.

A flexographic printing press is composed of four basic units: a fountain roll 1, an unlocking roll 2, a plate cylinder 3 and an impression cylinder 4. A 72-code letterpress printing plate 5 is attached to the plate cylinder 3, and an ink film is supplied from an unlocking roll 2. A corrugated cardboard sheet 6, which is a printing medium, is passed between the plate cylinder 3 and the impression cylinder 4, and is supported by the circumferential surface of the impression cylinder 4, while the other surface contacts the printing plate 5, and the sheet is passed through 8P, 8. Printing is performed while receiving a printing pressure of i or less.

(Problem to be solved by the invention) If the printing material is high-quality paper or a flat object, current printing machines and printing technology can print with high precision and high reliability without any problems. r printing is possible, but in the case of composite paper such as corrugated paperboard, in which 8 pieces of corrugated paper are interposed between two liners on the front and back sides, the liner on both sides of the sheet is 8 pieces.
The ridges of the paper are depressed in the thickness direction, creating a wavy surface and lacking flatness.

Moreover, the sheet has a structure in which there is a space in the inner layer and the front and back liners are supported by corrugated 8 paper, so the rigidity in the thickness direction is low, so when the printing pressure of the printing machine is applied, the corrugated cardboard sheet collapses irregularly. However, even if the sheet surface is not flat, as mentioned above, the printed code lines will tend to have uneven shading, or problems such as blurring, narrowing, and discontinuities. The problem is that it lacks reliability.

In order to eliminate the above-mentioned defects, various printing conditions (paper quality of the corrugated sheet, ink viscosity, hardness of the printing plate, thinning of the negative, etc.) of the corrugated sheet are determined by trial and error according to the conditions of the various coats 9, and corrugated sheet printing is performed. Do, 10 more
In order to achieve 0% reliability, all or a sample of the sheets printed by the box making machine must be printed offline, and manual checks must be performed using various barcode verification machines.Z
The cost involved is not negligible, and it is a major obstacle and problem in printing barcodes on corrugated cardboard sheets.

Therefore, one way to solve the above problem is to complete a system for determining defective products by installing a check mechanism for quality control on the printing device. However, in a cardboard printing machine, the sheet feeding speed is 3oOfn/lI.
At present, the bar code quality check or bar code reading device does not have a detection speed sufficient to cope with the above-mentioned traveling speed. for example,
When reading barcodes arranged parallel to the running direction,
- Cord width 2 (hw = running speed 300 m/
-, the ability to read in 0.004 seconds is required. However, in the current barcode league, the scanning speed is at most 200 times/sec, so 0.005sec71
times and does not meet the above required capabilities.

(Another means to solve the problem) A roll that is rotated at the same rotation speed as the plate cylinder is placed close to the barcode printing section, and a roll that rotates at the same rotation speed as the plate cylinder is placed on the circumference of the roll to determine the printing quality of the barcode or the code. The scanner is equipped with a detector that reads the bar code, and the detector is driven to rotate in synchronization with the moving speed of the printed bar code on the surface of the sheet being fed.

(Function) The detector installed on the roll that rotates at the same speed as the plate cylinder is rotated in synchronization with the moving speed of the barcode printed on the sheet surface, so the detector and the printing bar are Since a time interval is created in which the relative speed between the code and the code is approximately zero, it is possible to read the bar code quality in a so-called stationary state.

(Example) An embodiment of the present invention will be described below based on the drawings.

In Figure 1, 1 is a fountain roll, 2 is an unlocking roll, 3 is a plate cylinder, 4 is an impression cylinder, 5 is a barcode printing plate attached to the outer periphery of the plate cylinder 3, and 6 is a corrugated board sheet to be printed. . These have the same configuration as the conventional device described above.

Reference numeral 7 denotes a detection roll that is close to the printing section and rotates at the same rotation speed as the plate cylinder 3, and 8 is a detector installed on the circumference of the detection roll 7, which reads the barcode as a code. This is a well-known detector that checks the printing quality of barcodes, that is, the thickness of bars and spaces, color shading, scratches/stains, placement, etc.

The detector 8 moves in synchronization with the moving speed VB of the printed barcode 6B on the corrugated cardboard sheet 6 being fed.
They are rotated together with the detection roll 7 so that the circumferential speeds V of the detection ends of the rollers 7 and 7 are synchronized so that the circumferential speeds V of the detection ends of the rollers 7 and 7 are substantially the same.

With the above configuration, the detection roll 7 is rotated at the same rotation speed as the plate cylinder 3, and the moving speed VB of the barcode 6B printed on the sheet surface and the circumferential speed v8 of the detection end of the detector 8 are The detector 8 and the printed barcode 6B are rotated together with the detection roll 7 so that their speeds almost match and are synchronized. Therefore, the time interval R·θ/vB time during which the relative speeds of the detector 8 and the printed barcode 6B become approximately zero is set. Since [R is the detection end radius] is created, it is possible to detect the above time when both are stationary ◎In other words, in a corrugated board printing machine, the sheet feeding speed is high, so a stationary detector is used to detect the barcode. Detection requires instantaneous detection processing, and currently commercially available barcode detectors do not have sufficient ability to handle such processing speed.The physical means of the present invention solves the problem that That means it's resolved.

Next, an example will be described in which the above-described detection method according to the present invention is employed to identify barcode defective products and realize an on-machine quality control system. A schematic block diagram of the quality control system after the detector 8 is shown in FIG. As the detector 8, a barcode league was used which detects a barcode as a code among various possible detection functions as described above. Commercially available barcode leagues have a basic configuration in which light is emitted from a light source using a tungsten bulb, and the reflected light is received by a light receiving element via a lens, slit, filter, etc., and the emitted light is moved and scanned. method is adopted. The detector 8 is connected to a barcode identification device 9 that receives the signal of a break and identifies it as a code. The barcode identification device 9 receives the barcode signal from now on, compares it with a standard barcode that is separately input to the centralized control panel 10 for each order, and determines whether or not it is the same barcode. If it is determined that the barcode is a different type of barcode, that is, if it is determined that printing is not being performed properly, the information is sent to the determination and command device 11, which issues a command to the processing device 12.13, which will be described later. The marking device 12 exemplified here as an O processing device is a device that marks a mark for identifying defective products by means such as an inkjet or printing method on a cardboard sheet 6 that is defective for barcode printing. The discharge device 13 is a device that excludes defective products from the normal transport route for non-defective products.

(Effects of the Invention) Conventionally, when corrugated cardboard sheets were used as the substrate for printing barcodes, it was difficult to obtain printing accuracy and a great deal of labor was required for inspection work in the post-process, but according to the present invention, The quality of printing results is detected on the printing press, creating an online inspection system.

That is, barcodes on a cardboard sheet running at high speed can be inspected on a printing press using simple physical means.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an embodiment of the barcode printing device of the present invention, Fig. 2 is a block diagram of the quality control system in the device shown in Fig. 1, and Fig. 3 is a schematic diagram of a conventional barcode printing device. be.

Claims (1)

[Claims] In a barcode printing device that passes a corrugated sheet between a plate cylinder and an impression cylinder that constitute a printing section and prints a barcode on the surface of the corrugated sheet, a bar code printer that is located close to the printing section and rotates at the same number of rotations as the plate cylinder. A detector is installed on the periphery of the roll to read the barcode or its print quality, and the detector is synchronized with the moving speed of the printed barcode on the surface of the corrugated cardboard sheet being fed. A barcode printing device characterized in that it is configured to be rotationally driven.