JPH0643699Y2 - Flatbed proof press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a flatbed proof printing machine in which a print management data detection device has two light receiving elements for measuring different color components.

(Prior Art) According to the flatbed proof press proposed by the present applicant in Japanese Patent Application No. 59-6752, a print management data detection device mounted on a running frame is used for printing management along with a pattern. Measure the concentration of the application scale. Therefore, the print management scale is scanned and measured in the printing direction, but in order to know the printing state at multiple points of the pattern, a plurality of print management scales are distributed and arranged in the direction perpendicular to the printing direction, and The print management data detection device is adapted. If this becomes a two-color proof printing machine, please refer to Japanese Patent Application No. 59-162537 “Flatbed proof printing machine” relating to the same applicant for a method for efficiently measuring the number of scales and the number of detection devices. Have been proposed.

(Problems to be solved by the invention) However, this method has problems that the measurement accuracy is deteriorated as the concentration of ink used is increased and the concentration is increased. In addition, in offset printing, 2
It is also very important to measure the color density. That is, the printed matter reproduces all colors by overprinting a plurality of colors (standard four colors), and the colors reproduced differ depending on the balance of the densities of the respective colors. As an example, there is human skin, and since the skin color is reproduced by overprinting with yellow ink and magenta ink (printing at once with a two-color flatbed proofing machine), the tone of the skin color changes greatly depending on the balance. Therefore, it is extremely important to measure the densities of two colors at the same position in the traveling direction of the gantry in order to know whether this balance is proper. Furthermore,
It is also very important that the print management data detection device mounted on the frame of the flatbed proof press has a structure that is resistant to impact. That is, since the flatbed proof press is intended for high-mix low-volume printing, it is necessary to be able to easily exchange the plate and the paper. Therefore, the plate and the paper are placed on the surface plate and the blanket roller is placed on the surface plate. Printing is performed by running a gantry equipped with an inking roller and a dampening water supply roller, each roller descending on the surface plate, contacting with the plate or paper, and repeatedly rising. Therefore, the pedestal is constantly subjected to the impact of the roller descending, contacting, and ascending. Since the flatbed proof printing machine has a structure in which the gantry runs, there is only a structure above the surface plate, so it is necessary to install a data management device for print management that measures the print density of the paper on the surface plate on the pedestal. , The impact applied to the pedestal will be constantly applied to the data detection device for print management. Therefore, there is a problem that the measurement accuracy is reduced when the structure is not strong against impact, especially when it has a moving part.

(Problems to be solved by the invention) The present invention requires a scale control device for print management smaller than the number of scales for print management different in two colors in a two-color flatbed proof press, and has good measurement accuracy. An object of the present invention is to provide a flatbed proof press having a print management data detection device that satisfies the above requirements.

(Means for Solving the Problems) The present invention is a pattern on a printing paper by a plurality of print management data detection devices having a light source and a light receiving element provided at the rear edge of the gantry during the traveling process of the gantry. In the flatbed proof printing machine for two-color printing, which has a function of measuring the density of a plurality of print control scales printed together with the pattern and controlling the density of the pattern, a single-color scale composed of a plurality of dot percentages is provided in the frame running direction. Two arranged, each of which is a monochromatic scale pair printed in different colors of the two-color printing, and a print management scale formed by arranging a plurality of the monochromatic scale pairs in a direction orthogonal to the gantry traveling direction, With respect to the print management scale, a timing mark provided for each single color scale printed in the different color is provided at a lateral position in a direction orthogonal to the cradle running direction, and the cradle running A light source that sequentially irradiates each monochromatic scale of the print management scale according to the row, and a light receiving element that the reflected light sequentially enters,
By installing two light receiving elements on the pedestal, each light receiving element detects a plurality of print management data detecting devices for detecting the reflection density of color components having different monochromatic scales, and the plurality of print management data detecting apparatuses. An arithmetic circuit for calculating an output signal from the data detection device to calculate a density, a timing sensor for detecting a timing mark, and a signal from the timing sensor, and calculation from two light receiving elements of the print management data detection device. A flatbed proof press for two-color printing, comprising a gate for switching an output signal sent to a circuit.

(Embodiment) The present invention will be described in detail below based on an embodiment shown in the drawings.

Referring to FIG. 2, a flatbed proof press (11) according to the present invention
The two-color printing plate (not shown) is placed on the surface plate (12), and the frame (13) runs in the direction of the arrow to receive ink from the printing plate, and the pattern (15) is printed on the printing paper (14). At the same time, a plurality of print management scales (3) (three in this case) and timing marks (10) are printed. The print management scale (3) is measured by the print management data detection device (7) while the frame (13) is running.

In FIG. 2, the print management scale (3) is configured by arranging three monochromatic scale pairs (33) in a direction orthogonal to the printing direction. Each monochromatic scale pair (33) is shown in FIG. As shown, magenta 50%, magenta 100% magenta monochromatic scale (31) and cyan 50%, cyan 100%
It is configured by arranging a single-color scale for cyan (32).

FIG. 1 is an explanatory diagram showing the configuration of a print management data detection device (7) according to the present invention. Lens lamp (2)
The light emitted from is reflected by the print management scale (3),
Spectral filter (6) with about 45 ° reflected light collected by each condenser lens (4) (4) 'and having different transmission wavelength range
After passing through (6) ', each light receiving element (1) (1)' is reached. The output signals of the light receiving elements (1) and (1) 'are amplified by the circuit board (5), logarithmically converted, and converted into density data. FIG. 3 shows an example of the timing mark (10) having the same length as the print management scale and the print management scale when printing two colors of magenta and cyan on a two-color proof printing machine. In this example, from the left, magenta 50% and magenta 100
%, Cyan 50%, cyan 100%.

FIG. 4 shows the density output when the scale of FIG. 3 is measured by the detection device (7) shown in FIG. In this case, a green filter is used as the filter (6) and a red filter is used as the filter (6) '. FIG. 4 is a logarithmic representation of the amplified outputs from the two light receiving elements. FIG. 4 (a) shows the output from the light receiving element (1), and FIG. 4 (b) shows the light receiving. It is the output from the element (1) ', and the M portion of the output is adopted as the magenta printing management scale density and the C portion is adopted as the cyan printing management density. The magenta and cyan signals are captured by the print management scale at the interrupted point (16) while scanning the timing mark (10) with the timing sensor (9) shown in FIG. This is set as a change point in correspondence with the boundary line between the magenta part and the cyan part in (3).

FIG. 5 is a block diagram of the signal processing in this embodiment. The magenta light receiving element (1) and the cyan light receiving element (1) 'are respectively log amps (22) (22) via operational amplifiers (21) (21)'. ) 'And subjected to amplification and logarithmic conversion to obtain a signal as shown in FIG. on the other hand,
The timing sensor (9) scans the blank area as the gantry is running, and sends a signal to the mark detection circuit (23) according to the intensity of the reflected light.

When a mark is detected, a signal is sent to the gate (24) and the signal of the M part from the magenta light receiving element (1) is calculated by the arithmetic circuit (25).
Pass through. When the platform (13) further travels and reaches the break (16), the level of the signal from the sensor (9) changes, and the mark detection circuit (23) detects this and the gate (24) receives the cyan light. The output signal from the element (1) 'is switched so as to be sent to the arithmetic circuit (25).
The gate (24) closes when the sensor (9) comes off the timing mark (10).

(Effect of the Invention) According to the flatbed proof press having the print management data detection device of the present invention, the two-color proof press is used for printing control by connecting the monochromatic print control scales for two colors in the printing direction. The number of data detectors can be halved compared to disposing the two-color monochromatic print management scales at right angles to the printing direction, and the measurement accuracy does not deteriorate at all. Is.

Moreover, it is possible to measure a monochromatic scale printed in two different colors that are linked in the running direction of the gantry. Furthermore, by switching the output signal sent from the two light receiving elements to the arithmetic circuit by the gate, data detection for print management can be performed. This has the remarkable effect of reducing the number of operating parts of the apparatus, and even if the apparatus is installed in a place where a shock is constantly applied such as a stand of a proof printing machine, the measurement accuracy does not deteriorate at all.

[Brief description of drawings]

FIG. 1 is an explanatory view of a print management data detection device installed in a flatbed proof printing machine of the present invention, FIG. 2 is an explanatory view of main parts of the flatbed proof printing machine, and FIG. 3 is a print management scale. FIG. 4 is an explanatory diagram showing an example of contents and timing marks, FIG. 4 is an explanatory diagram showing density outputs of magenta and cyan, and FIG. 5 is a block diagram of signal processing. (1) (1) '... light receiving element, (2) ... lens lamp,
(3) ... Print management scale, (4) (4) '... Condensing lens, (5) ... Circuit board, (6) (6)' ... Spectral filter, (7) ... Print management data detection device, (9) ... timing sensor, (10) ... timing mark, (1
1)… Flatbed proof press, (12)… Surface plate, (13)… Stand,
(14), ... Printing paper, (15) ... Design, (16) ... Break,
(31)… Magenta monochromatic scale, (32)… Cyan monochromatic scale, (33)… Monochromatic scale pair

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-53-708 (JP, A) JP-A-55-55233 (JP, A) JP-A-50-133014 (JP, A) Actual development Sho-52- 171979 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A plurality of print managements printed on a printing paper together with a pattern by a plurality of print management data detection devices having a light source and a light receiving element provided at a rear end edge of the gantry during a traveling process of the gantry. In a flatbed proof press for two-color printing, which has a function of measuring the density of a scale for density control of the design, two single-color scales composed of a plurality of dot percentages are arranged in the gantry traveling direction, each of which is A pair of monochromatic scales printed in different colors of the two-color printing, a print management scale in which a plurality of the monochromatic scale pairs are arranged in a direction orthogonal to the gantry traveling direction, and a scale for the print management , A timing mark provided for each monochromatic scale printed in the different color at a lateral position in a direction orthogonal to the gantry traveling direction, and for the print management according to the gantry traveling. The scale comprises a light source for sequentially irradiating each monochromatic scale of the scale and a light receiving element to which the reflected light is sequentially incident. By installing two light receiving elements on the mount, each light receiving element has a different color component of the monochromatic scale. A plurality of print management data detection devices for detecting reflection densities, an arithmetic circuit for calculating output signals from the plurality of print management data detection devices to calculate densities, and a timing mark detection timing detection device A flat base for two-color printing, comprising: a sensor; and a gate for switching an output signal sent from two light receiving elements of the print management data detection device to an arithmetic circuit according to a signal from the timing sensor. Proof press.