JPS6328423Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field] This invention is based on the color information obtained by optically measuring a color sample, and uses C (cyan), M (magenta), and Y (yellow) for printing. ), BK (black), and how to calculate and display the halftone area ratio of each color separation.

[Technical background]

2. Description of the Related Art Conventionally, a small piece of paper called a color sample for specifying a color is sometimes attached to a printing layout sheet for the purpose of an orderer specifying in advance the color of a certain part of a printed matter.
For example, when it is desired to uniformly fill the background of a picture with a certain color, a small piece of paper having the color of the background is attached as a color sample and brought to a printing factory.

In printing factories, the most common multicolor printing method is C, M, Y color separation plates or C, M, Y,
To print a designated area in the same color as the color sample in a 3-color or 4-color printing method using BK color separations, use the C, M, Y separation plates or C, M,
The percentage of dot area for each of the Y and BK color separation plates is determined, and the color separation plates are prepared and printed under these conditions.

Conventionally, the above-mentioned work involves preparing a color chart, which is a collection of many printed matter, in which the dot area ratio of the C, M, Y, and BK color separation plates is changed at intervals of about 10%. , visually compare the color swatch with each color in this color chart, select the color closest to the color swatch from the color chart, and use the color chart to print the colors needed to print each color in the color chart. Using the fact that the halftone area ratio of each color separation plate is listed, find out the halftone area ratio of each color separation plate required to print the color selected above, and use the color separation with that halftone area ratio. A plate is made and printed to reproduce the colors specified in the color sample.

However, with this method, the work is done manually, and since there are a huge number of colors in the color chart, it takes time to compare them with color samples, and the colors selected from the color chart vary depending on the worker. However, the disadvantage is that the reproduced colors tend to vary.

On the other hand, reflection densitometers are currently available on the market that can measure the density of the object to be measured and calculate the dot area ratio, but there are limits to their applicability due to the influence of the turbidity component of the printing ink.

[Purpose of the invention]

This invention was made to solve the problems of the prior art as described above, and its purpose is to change the color specified in the color sample to Y, M, C or Y, M, C, Calculate the accurate halftone area ratio of each color separation plate when reproducing BK by overprinting,
The present invention provides a display device.

[Summary of the idea]

This device consists of a measuring device for obtaining color information, an arithmetic circuit that converts the color information from the measuring device into a combination of halftone area ratios for each printing plate, and a main body that includes a display section, an input section, etc. By measuring the color sample, the combination of halftone dot area ratios of Y, M, and C plates is displayed, and by inputting from the input section, the combination of halftone dot area ratios of Y, M, and C plates is displayed. This is to convert and display a combination of dot area ratios for C and BK versions.

[Detailed explanation of the idea]

Hereinafter, preferred embodiments of this invention will be described in detail with reference to the drawings. FIG. 1 is an overall view of the apparatus used to implement the invention, in which a measuring head 10 is connected to a main body 100 by a cable 50. The measurement head has at least a built-in light source, a filter, and a photoelectric conversion element, and is used to obtain color information from a color sample. The main body 100 also has a built-in arithmetic circuit that converts the color information input from the measuring head into a dot area ratio of each printing plate, a display section 101 that outputs the arithmetic results, and an input section 1 such as a keyboard.
02 is placed on the front. The switch 103 is a main switch that controls power ON/OFF.

FIG. 2 is a block diagram for explaining the electrical circuit of the device shown in FIG.

The reflected light of the color chart or color sample illuminated by the light source 25 passes through the optical filter 31, and only the light of a specific color component is received by the photoelectric conversion element 23, which generates electricity according to the amount of received light. converted into a signal. The photoelectric conversion element 23 has logamp105.
is connected, and this logamp 105 converts the electrical signal into color density.

A tungsten lamp or a halogen lamp can be used as the light source 25, and a photomultiplier or a photodiode can be used as the photoelectric conversion element 23.

The optical filter 31 is a vapor deposition filter or a gelatin filter, and has at least R, G,
The structure is such that the three color filters of B can be sequentially rotated manually or electrically.

The color density signal is sent to an analog-to-digital converter 106.
The data is converted into digital data and input to the CPU 110 via the data bus DB.

The CPU 110 includes a random access memory (RAM) 111, a read-only memory (ROM) 112, a display controller 103,
Keyboard controller 104 is data bus DB
It is connected at.

Further, the display unit 101 is connected to a display unit controller 10.
3, and displays the calculation results by the CPU 110. A keyboard 102 is provided for inputting data such as dot area ratio data of the color chart and for giving various commands to the CPU 110.

Various types of display devices can be used, including a liquid crystal display device, an LED display device, and a fluorescent display tube display device.

Also, the data sent to the CPU 110 or
The result calculated by the CPU 110 is sent to the address bus
The address to be stored in RAM 111 or ROM 112 is specified by CPU 110 via AB.
It is stored in RAM 111 or ROM 112.

The RAM 111 stores, for example, a combination of color densities of measured color samples, and the ROM 112 stores, for example, a program for operating the CPU 110 or a color density-dot area ratio conversion table.

Using the apparatus according to the present invention, the halftone area ratio of each color separation plate capable of reproducing the color of the object to be measured, for example, the halftone area ratio of each color separation plate of Y, M, and C, and the BK plate, can be determined. Y, M, C, BK when added
The method for determining the dot area ratio of each color separation plate can be found in Japanese Patent Application No. 58-249661 filed by the present applicant, and the details thereof will be omitted here.

The calculated dot area ratio of each color separation plate is displayed on the display unit 101, and the display method is Y,
The halftone dot area ratio of each color separation plate of M and C is displayed first, and then Y,
The halftone area ratio of each M, C, BK color separation plate is Y, M,
If each C color separation plate is displayed at the same time or only, it corresponds well to general three-color printing or four-color printing, and is very suitable for actual production plans.

[Effect of idea]

As mentioned above, the dot area ratio determination device of the present invention is extremely compact and easy to use, and it also has a display suitable for three-color printing or four-color printing, which is often performed in general printing. This is extremely practical.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the dot area ratio determination device of the present invention, and FIG. 2 is a block diagram thereof. 10...Measuring head, 100...Main body, 101
...Display section, 102... Keyboard (input section).

Claims (1)

[Scope of utility model registration request] It has a light source, a spectral filter, and a photoelectric conversion element,
It has a built-in measuring device for obtaining color information and an arithmetic circuit that calculates a combination of halftone area ratios corresponding to color separation plates of multiple colors from the color information, and a display section and an input section connected to the arithmetic circuit. The display section displays the combination of dot area ratios for each of the Y, M, and C versions calculated by the arithmetic circuit. The combination of the dot area ratios of the Y, M, and C versions is converted into the combination of the dot area ratios of the Y, M, C, and BK versions, and the dot area ratios of the Y, M, and C versions are The combination and the combination of Y, M, C, and BK versions are displayed at the same time, or the combination of Y, M, C, and BK versions is displayed after the combination of halftone area ratio of Y, M, and C versions is displayed. A dot area ratio determining device characterized by: