Discussion on digital quality control technology o

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Discussion on digital quality control technology of color printing

in some traditional printing methods, generally consistent printing plants have a roller scanner to make characteristic correction according to their back-end printing equipment, and then use some color control inverted tables as tools to correct their characteristic curves to complete a circular color monitoring program. (Mr. zouyukai on the left) when we are doing the color monitoring program, we can use some guide tables to cooperate with the visual judgment of the human eye as a reference index to correct some color deviations. However, because Taiwan still does not have a set of fairly standard quality control indicators, printing practitioners do not have a set of reference standards and are at a loss. From the perspective of the continuous growth of printing equipment in the United States since the 1990s, the total annual demand for printing equipment remained at more than US $400million around the year 2000, which represents the continuous growth of the demand for printing equipment. In addition, digital printing machines (printing more than 24 pages per minute) also showed a large growth trend. Most people believe that a color cannot be recognized without actually seeing it. Certain experimental machine testing technology can realize experiments that could not be completed by manual operation in the past. It is believed only by "seeing", but can human eyes really be believed? The human eye judges the color according to the three +r, G and B sensing cells in the eye. However, in a dark environment, these three cells cannot play their normal functions and often produce some unexpected color judgment errors. In printing houses, printers often rely on their own eyes to judge the formula of a special color, and think that the color is similar, so they can directly print on the machine. This method has many shortcomings: 1 Waste of time 2 The color matched in a dark environment is very different from the actual color. 3 The eyes of people who waste money often cause color judgment errors due to the influence of some surrounding environment. Therefore, we must use some quality control tools to help us judge colors and establish quality control standards. In terms of color communication, each country has a color system developed by them, such as Munsell eye color system in the United States, Ostwald in Germany, and color rendering system in Japan. Different national standards cause difficulties in color communication. Therefore, it is necessary to unify the naming of colors, pay attention to color matching, and have coordination and consistency. In person "In the past two years, in addition to the common densitometer and colorimeter, there is also a spectrophotometer that can measure the characteristics of luminous objects. It can calibrate the screen, or measure the standard color disk, etc. there is a laser ball inside it, which can measure the spectral curve of the color ticket, but because of its high price, it is less suitable for Taiwan printing plants. The use of digital cameras is becoming more and more popular, but due to There are individual differences in each digital camera. Therefore, in order to correct each digital camera, scientists use the "digital color disc" to create an exclusive profile for the digital camera to correct the difference between the RGB signal of the camera and the human eye. After the screen is calibrated and characterized, an ICC profile can also be generated, but there must be a prerequisite, that is, you must have a colorimeter as a quality control tool to assist the human eye. When we are doing screen color comparison, we must reduce the influence of the surrounding light sources, turn off all the light sources, and make adjustments in a completely dark environment to avoid affecting the accuracy of screen correction. The prevalence of international roads makes people have to watch the same color through different screens in different places. In order to achieve such a goal, we must correct the remote screen to the same state, Only in this way can we achieve the purpose of CMS color management. Printing reproduction theory is different from colorimetry. In color management, most people only pay attention to the theory of colorimetry, but density is the basic. Digital workflow is a new method for printing plants to improve production capacity. Only by working towards digital production processes can printing plants improve their competitiveness. The application of quality control tools is because the human eye is too subjective in judging color and lacks an objective measurement standard. Therefore, quality control tools are needed to assist the human eye as the basis for judging color. Use quality control tools more. Don't trust your eyes to cope with the prevalence of the international road. All printing production may become a process of viewing on the screen, so printing soft proofing becomes very important, Screen 1 villager said that the correction is relatively necessary

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