JPS60217154A - Flat-bed correction printing machine - Google Patents

Abstract

PURPOSE:To obtain data for managing printing in high accuracy by correcting print managing data from a print managing scale on a print sheet by data detecting means by calibration from a reference plate. CONSTITUTION:Print sheet is detected by detecting means 13 having a light source 16 and a photoreceptor 14 for pure white portion and reflected light amounts between white plate and black plate of reference plate 85 telescoped in an optical path, i.e., the density is detected, compared within stored reference plate reference density to obtain correction coefficient. Then, picture element and print managing scale 11 are printed on the print sheet 3, the correction coefficient is multiplied by the data form the scale 11 obtained by the means 13, corrected, compared with reference printing density data set in the memory, and data for indicating the printed state is displayed on an output device. Then, ink filling quantity is regulated and ink viscosity is also regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method in which printing paper is placed on a surface plate, and a frame to which a blanket roll is attached moves on the surface plate to print on the printing paper. It relates to a flatbed proofing printing machine, and in particular, a flatbed with a δ that allows the printed state of the proof print to be easily grasped by measuring the printed print management scale with a detection means and obtaining print management data. It concerns a proof printing machine.

2. Description of the Related Art Conventionally, it is customary for printed matter produced by a proof printing machine to have a pattern section and various management scales printed thereon.

In addition, the control method often relies on a method in which a proof printing machine operator looks at the pattern, or a method in which a proof printing machine operator measures the density using a printing control scale.

However, the former depends on the skill level of the proof printing machine operator who judges the density of the printed matter, and is also affected by illusions caused by the proof printing machine operator's visual proficiency, visual conditions, and image content. , it is impossible to make a fair evaluation. Also, post-process especially 2
．． 3. In the printing process for the fourth color, it is possible to print while maintaining the color balance using the first color as a reference, but the first color has no color printing to serve as a reference, and visual judgment is extremely difficult. Further, even if the color balance is maintained by visual inspection, the overall density may fluctuate depending on the lot of proof printing. In the printing process of this machine, proof prints are printed using printing plates with various layouts, but at this time, the density balance of each proof print is different and it is extremely difficult to make the density balance constant.

In the latter case, the concentration of the scale is measured. This method is usually carried out by the operator of the proofing press, and the interval between density measurements may vary depending on the individual of the operator of the proofing press.
Alternatively, it is undefined depending on the frequency of inking, etc.

FIG. 1 is an explanatory diagram of the work when measuring the density of a print management scale. Printing paper (3) and printing plates (4) are placed on the surface plate (2) of the flatbed proofing printer (1), and a dampening water roll (5) and ink mixing roll (6) are attached. In addition, a dampening roll, an ink depositing roll, and a plunket roll are attached to the pedestal (7).
As the pedestal (7) moves on the surface plate (2), the dampening roll, ink dressing roll, and plunket roll also move together. As a result, dampening water and ink adhere to the printing plate (4), and the ink is further transferred to the blanket roll, and then transferred from the blanket roll to the printing paper (3) for printing.

In the case of multicolor printing, the printing plates and inks are replaced, or multiple similar proofing machines are used to overprint on the same printing paper.

When printing is performed in this manner, a print management scale is printed on the margin of the printing paper for each color. In order to obtain print management data such as density from this printing tube 1 embedded scale i, remove the printing paper from the proof printing machine every time you print and move it to the stand (8) where the needle is installed. The densitometer (9) must be carried and manually operated to measure a degree. Therefore, obtaining print management data is a very time-consuming task.

Furthermore, since the number of #markers is generally much smaller than the number of proof printing machines, there is often a large distance between the proof printing machine and the densitometer. In this case, the task of obtaining print management data becomes increasingly troublesome. Also, if you spend a long time measuring the density of printed matter without continuous operation during proof printing, the dampening water on the printing plate (4) on the proof printing machine (1) may evaporate. In this case, the proof printing operator manually supplies dampening water using a sponge or the like, and printing conditions cannot be made constant due to differences in the amount of dampening water. Also, due to changes in the condition of the ink on the blanket roll ink mixing roll, etc.
It is undesirable to take unnecessary time between prints. For this reason, the frequency of operations for obtaining print management data using a densitometer or the like as described above must be reduced.

As mentioned above, ink viscosity adjustment, which is an appropriate means to keep the quality of printed matter constant in proof printing, is not enough to use a combination of visual inspection of the pattern and infrequent concentration measurement using a control scale over a long period of time. , it is not possible to effectively adjust the amount of ink applied to the left and right sides of the ink roller, adjust the amount of dampening water, etc.

On the other hand, several types of automatic concentration measuring devices are on the market. Among these devices, there is a device that uses a control scale to measure the density by placing a printed matter in a fixed position and a densitometer moves on its own, or a device that stores the area of the pattern of the printed material to be measured in vertical and horizontal coordinates.
There are devices that automatically measure the part you want to measure.
Compared to using a manual densitometer, there is almost no benefit in increasing the frequency of measurement, since it takes a certain amount of time to carry the printed matter from the proof printing machine to a separate table and perform the measurement.

In general, variations in the density of printed matter produced by a proof printing machine also appear in the direction perpendicular to the printing direction, at the mouth and bottom of the printed matter, and at the same position on consecutive printed matter. In particular, due to the fact that inking is done manually, the variation in the direction perpendicular to the printing direction is the widest. Moreover, the management of density variations in printed matter is currently mostly carried out based on the intuition of proofreading press operators due to the difficulty in measuring density as described above.

The present invention solves the above-mentioned conventional drawbacks.1. The object of the present invention is to provide a flatbed proofing printing machine which performs calibration using a standard plate for each measurement and has a detection means with high measurement accuracy.

Next, the present invention will be explained in more detail with reference to the drawings.

FIG. 2 is an explanatory diagram of the pedestal portion of the flatbed proofing printer of the present invention, and shows the printing paper (3) placed on the surface plate (2).
), the ink is transferred by a blanket roll that receives ink from the printing plate (4) installed on the pedestal (7), and printing is performed. In this case, it is assumed that printing is performed rightward from the pressure in the figure.

In this case, print management scales (1υ) are printed in two places on the printing paper (3) in addition to the picture area (10) and its margin area.

Print management scale (11) used in the present invention
An example of this is shown in FIG.

Three types of halftone dot patterns are printed on this print management scale, and in this example, a pattern with 30% halftone dots (71), a pattern with 70% halftone dots (72), and a pattern with 100% halftone dots.
% (solid) pattern (73) is printed. Note that (75) indicates each halftone dot pattern (71), (72) by a data detection means moving in the direction of arrow (7 (a), which will be described later).
, (73) is a timing mark provided so that the data of (73) can be detected. Note that the timing mark may be a solid batch provided parallel to the print management scale as shown in Figure 8 (90), and an arrow (91) is drawn above this mark (90) for timing purposes. The timing may be determined by passing through a dedicated sensor.The scale for print management is not limited to the one shown in FIG. 6, and three or more types of halftone dots may be used.

On the other hand, bars (12) are attached to the end of the pedestal (7) parallel to the axis of the plunket roll, and a data detection means (13) is attached to one of the bars. In the example shown, the print management scale (1υ) and the data detection means (13) are each located at two locations.
They have corresponding positional relationships.

The data detection means (13) extends over the bar (12) so that the mounting position can be adjusted, so that the data detection means (13) can be placed at a position where it passes over the printed print management scale (11). It can be fixed.

3 and 4 show one embodiment of the data detection means (13).

The light receiving element (14) has a printed management scale (
11) Photoelectric conversion is performed by receiving the reflected light of the light irradiated on the surface, and includes phototubes that utilize the photoelectron emission effect, photomultiplier tubes, photoconductive cells that utilize the photoconductive effect, and photovoltaic effects. Various types of elements such as photodiodes can be used, and their shapes may be single or composite. For example, when the output current or voltage is weak as in the case of a photodiode, an amplifier (15) is used to amplify the output current or voltage.

The eyep (15) needs to be close to the light receiving element (14). Data detection means (13) and printing paper (
3), external light may enter the light receiving element (14) and become a factor affecting measurement accuracy. Therefore, the distance (di) should be made as small as possible, and if there is a risk that external light may enter the light receiving element (14) as a non-ignorable amount of light compared to the amount of light from the light source (16) in terms of measurement accuracy, use a light shielding plate. (24) as much as possible, and by providing a light absorption layer such as black paint on the outside of the light shielding plate (24) and the bottom (25) of the data detection means (13), the influence of external light can be suppressed. By doing this, the external light that reaches the light-receiving element (14) becomes extremely weak, and it hardly affects the measurement accuracy. However, due to the structure of the proof printing machine, , distance (di) cannot be made small, or the light shielding plate (24
), more external light may be incident on the light receiving element (14) than when the above measures are taken, but if the amount of incident light is constant, a calibration curve etc. should be created in advance. This data may be stored in a storage device and the calibration curve may be called up as appropriate to correct the measured values.

The light source (16) can be a halogen lamp, a tungsten lamp, a high frequency lighting type fluorescent nail, or the like, but a halogen lamp is preferable from the viewpoint of light intensity and stability. The normal angle between the print management scale (11) and the chief ray from the light source (16) is preferably 30' to 60°, preferably 45°. In order to reduce the effect of the heat emitted by the light source (16) on the light receiving element (14), it may be necessary to move the light receiving element (14) as far away as possible, and also to provide ventilation with a fan or the like, or use heat insulating material. In some cases, it may be necessary to sufficiently cover the light-receiving element with an optical fiber.Transmit the light from a light source that is sufficiently far away from the light-receiving element using an optical fiber, and create a print management scale (1).
It is also possible to receive the light reflected by the print management scale (11) using an optical fiber and transmit it to a light receiving element that is sufficiently far away from the light source, making it possible to miniaturize the print management data detection means and reduce the distance from the light source. This may be effective in reducing fluctuations in the light receiving element due to heat.

A reflector (18) may be attached to the light source (16) to increase the amount of light. The light source (16) or light passed through the optical fiber from the light source illuminates the print management scale (1υ) through the small hole (19). This is to prevent reflected light from entering the light receiving element 0a.The light reflected from the print management scale (11) enters the light receiving element (14) through the tube (20).The tube (2 is the light source) (16) to prevent the light from directly entering the light receiving element (14).A spectral filter (21) is installed in front of the light receiving element (14).The spectral filter (21) is a gelatin filter. , any of the interference filters <-1(
, G, B or amber filters can be converted. There is also a light source (16) and print management scale (11).
), lenses (22) and (23) may be placed between the print management scale (11) and the spectral filter (21) to collect light and improve efficiency. Also, the lens (
By attaching 22) and (23), the light source (16)
It is also possible to prevent stray light from entering the light receiving element (14).

Further, a standard plate (85) for calipresicon is built into the data detection means. This calibration standard plate (85) is configured to take two positions: a position where the light receiving element (14) can receive the reflected light, and a position where it does not interfere with the reflected light from the printing paper.

In the example shown in Fig. 3, there is a light receiving element (14), an amplifier (15), a light source (16), a tube (17) (2), a reflector (18), a spectral filter (21), a lens (22).
(23) is attached to a moving plate (88), and the entire moving plate (88) moves up and down by the rotation of a stepping motor (86). The mechanism is such that the distances between the light source and the printing management scale and between the printing management scale and the light receiving element are made the same. That is, the rotation of the stepping motor (86) is transmitted to the shaft (91) by the bevel gear (89), and the rotation of the stepping motor (86) is transmitted to the shaft (91) by the bevel gear (89).
Two gears (90) are attached to the moving plate (c).
The above operation is performed by driving two racks (87) that are integrally provided in the.

Meanwhile, in parallel with the above operation, a stepping motor (80
) rotates, and the gear (92) attached to the rotating shaft of the motor moves the calibration standard plate (E) between the printing paper (3) and the light receiving element (14) via a rack provided on its side. The operation of sending the light into the optical path and the operation of returning it to the original position are performed.

As a result, when measuring the calibration standard plate (85), the stepping motor (86) is rotated to raise the movable plate, and the stepping motor (86) is rotated to raise the moving plate.
8. Rotate the calibration standard plate (85)
is sent to the position where the light from the light source is focused, and in this state data is captured from the light receiving element. On the other hand, printing paper (
3) When measuring the data on the print management scale (11) above, it is sufficient to return it to the standard plate (85) and the original position shown in FIG.

FIG. 4 shows another embodiment in which gears (97) and (98) are attached to the rotating shaft of the stepping motor (94), and the gear (97) connects the cylinder (21) through a rack.
The arm (95) to which is attached is moved back and forth, and the calibration standard plate (85) is moved back and forth via the rack using the gear (98). The amount of feed of the standard plate (85) by the gear (98) is larger than that of the gear (97).
The cylinder (21) can be moved back and forth between the solid line position where the print management scale is measured and the dotted line position where the standard plate (85) is measured. At this time, the difference in output current or voltage from the light receiving element caused by the difference in the distance between the light source (standard plate), the standard plate - the light receiving element, the light source - the scale for printing management, and the distance between the scale for printing management and the light receiving element is an electrical You can correct it accordingly.

This standard plate for calibration includes white only, white
Although it is possible to use only black or one with three or more different reflection densities, in this embodiment, white and black ones are installed. Materials that can be used include color tape, exposed photographic paper, printed matter, and objects coated with paint, but blackboards and blackboards coated with white paint are preferred for durability and stability.

Here, such a standard plate for calibration (8
The purpose of providing 5) is that the light source, light-receiving element, amplifier, etc. in the detection means may deteriorate over time due to characteristic deterioration, temperature drift, etc.
Amplifiers exhibit characteristic changes, and even when measuring the same object, the output fluctuates and is not constant.

In such a state, accurate data detection cannot be achieved, and for this reason, it is necessary to calibrate the data captured by the detection means, and it is necessary to perform calibration on the data captured by the detection means. This is the calibration standard plate.

The timing to drive the stepping motor is
In order to automatically perform this while moving the stand for printing,
A rimming switch is provided on the side of the surface plate (2), and when the mount that moves it touches it, the I'm running away from work (good).

Next, processing of measured data will be explained based on the block diagram of the data processing circuit shown in FIG.

The mount (7) moves on the surface plate from left to right in FIG.
85), an electric signal corresponding to the amount of reflected light is obtained. This electric signal is inverted by an inverting amplification circuit C11l, and further l
The logarithm of the og circuit is converted into density data, which is then converted into digital data by an analog-to-digital conversion circuit (c).

The switching circuit (foundation) is a standard plate for calibration (85)
Since the subsequent processing circuits are different between when measuring the scale (11) of the printing paper (3) and when measuring the scale (11) of the printing paper (3), the signal flow is switched. For example, this switching circuit detects the end of measurement of the calibration standard plate at the passing position of the mount, and automatically switches to the data processing side of the print management scale based on that signal. be able to.

The white and black density data of the standard plate (85) are stored in the standard plate reflection density storage circuit (to), and the white and black density data of the standard plate stored in the separately provided standard plate reference density storage circuit OD are stored.
A comparison calculation is made with the black reference density data in the correction coefficient calculation circuit (TO), thereby determining a coefficient for correction of the print management data, and storing it in the correction coefficient storage circuit (TO).

Next, the mount (7) moves further while printing the pattern (1) on the printing paper (3), and then the print management scale (11) is printed, and the print management scale (11)
is measured by the detection means (13). The timing of detection is performed based on the timing mark as described above.

In this example, the pattern σ°C has 30% halftone dots, and 70% halftone dots.
pattern (72), 100% halftone pattern positive circuit 0
sent to η. When the correction circuit has a zero value, these print management data are multiplied by the correction coefficient of the correction coefficient storage circuit (to), and the above-described purpose calibration is performed.

The calibrated print management data is used by the comparison calculation circuit (411K) to determine the standards for the 30% halftone pattern, 70% halftone pattern, and 100% halftone pattern stored in the standard print density data storage device. The difference in the density value of each halftone dot percentage or the state of dot gain is determined.

This calculation result is output to an output device such as a CRT7' display or a printer, and by looking at this output result, the proof printing machine operator can make appropriate adjustments such as adjusting the amount of ink and adjusting the ink viscosity to obtain proper printed matter. It becomes possible to take action.

Note that the processing circuit, CRT display, printer, etc. described above may be placed near the printing machine and set on a table.

Figure 6 shows CI (T display (61) as an output means.
) is an explanatory diagram showing an example of an output result.

The display (61) in FIG. 6 shows the density (62) and dot gain (64) of the print management scale described above, as well as the reproduction curve (63) based on the reference print data and the reproduction curve (64) obtained from the measurement results. ) and appropriate treatment methods (65) (ink viscosity adjustment, left/right fill balance, dampening water, etc.) as needed. In this example, density information from several sheets before is also shown.

Furthermore, in the case of a one-color flatbed proofing printer, four flatbed proofing printers can be centrally controlled, or the data stored in a data storage means for print management can be stored on a magnetic tape, magnetic card, floppy disk, etc. By transferring the data to the flatbed proofing printer for the next process, the second, third, and fourth color flatbed proofing printers can also output print management data for the previous process.

There are various types of print management scales, and they are often printed in multiple locations.In such cases, multiple data detection means can be installed to enable printing management data from multiple locations to be read. Obtainable.

In addition, the data detection means can be mounted on a bar (12) and its mounting position can be adjusted in parallel to the axis of the plunket roll according to the printing position of the print management scale.
It can be used for a variety of printed materials.

As described above, according to the flatbed proofing printer of the present invention, it is possible to obtain print management data on a print management scale immediately after printing.

Therefore, appropriate processing for the next print can be quickly taken, and by transmitting the print management data to the operator of the next color proof printing machine, the previous color and the proof print, machine work, etc.
This makes it possible to work while taking into account the balance with the colors that the person is in charge of. In addition, the output data can be used as reference material for proof printed matter as a sample for the machine when managing printed matter later or creating printing plates for this machine.

Since the number of proof prints is about 20 or less at most, it is also possible to obtain print management data for individual proof prints and use this data, which facilitates quality control.

Moreover, since the print management data is calibrated, accurate data measurement and management data output are always possible.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of how to obtain print management data using a conventional flatbed proofing printer, Figure 2 is a partial illustration of the flatbed proofing printer of the present invention, and Figures 3 and 4 are print management data. 5 is a block diagram of a processing circuit for print management data in the flatbed proofing press of the present invention; FIG. 6 is an explanatory diagram of an example of output from a CRT display; FIGS. 7 and 8 are Explanatory diagrams of print management schools are shown. (1) - Flatbed proof printing machine (2) - Surface plate (3)
・-Printing paper (4) ...Printing plate (5) ...
Dampening water roll (6) ... Ink mixing roll (7)
... Frame (8) ... Stand (9) ... Densitometer (10) - ... Image part (11) ... Scale for printing management (12 bars... Bar (13) ... Print management data detection means (14) --- Light receiving element (15).
...Amplifier (16) ...Light source (18) ...Reflector (19) ...Small hole (17), (20) ...Cylinder (2
1)...Spectral filter Ni ((2)...Lens C31...Correction circuit (4([1...Comparison calculation circuit (50)...Calculation means -...Output means (6υ11
．． Display (62) ---Density (6)), (6
4)...Reproduction curve υυ, σ21. αT... Halftone dot pattern (74) - Arrow (7 (G)... Timing mark (85)... Standard plate patent applicant Toppan Printing Co., Ltd. Representative Kazuo Suzuki Figure 2. Figure 7

Claims (1)

[Claims] 1) A flat platform on which a printing plate and printing paper l are placed on a surface plate, and a mount to which a blanket roll is attached moves on the surface plate to print a pattern and a print management scale on the printing paper. In the proof printing machine, a data detection means installed on the mount and including a light source and a light receiving element that receives the reflected light and converts it into an electric signal, and an optical path connecting the printing paper and the light receiving element in this data detection means. A calibration standard plate provided so as to be freely visible and retractable, and print management data from a print management scale on the printing paper obtained by the data detection means are corrected with calibration data from the calibration standard plate. A correction means, a calculation means for comparing the corrected print management data with separately input reference print data, and outputting data indicating a printing state, and an output means for outputting the calculation result. A flatbed proofing printing machine characterized by: