Key words: optical modulator digital printing data processing Abstract: The seeay lays emphasis on expiunding significant application of the laser modulation scanning technoligy.And inlroducesit from both computer to plate and computer to print respectively.Thereby making further understanding of computer to print. Keyword:light modulator,computer to print;data processing
Laser is an emerging discipline based on optics, atomic physics, and electronics. Since the world’s first laser was born in the 1960s, laser and laser technology have developed into important high technologies. Its theory and application have revolutionized many technology fields. The printing industry has entered the era of "light" and "electricity." This article only discusses the impact of laser on the development of printing modernization and discusses the important position and application of laser technology in modern printing technology.
First, the laser modulation laser can be used as a tool for transmitting information. The process of loading the information (digitalized image and text) to be transmitted to the laser radiation is called laser modulation. Because the laser plays a role of “carrying” information, it is called Carrier.
Modulators used in printing mainly include electro-optic modulators and acousto-optic modulators. Actual applications are mostly acousto-optic modulators. The acousto-optic modulator consists of an acousto-optic medium, an electro-acoustic transducer, a sound-absorbing device, and a driving power source.
The acousto-optic medium used for acousto-optic modulators in printing equipment is the lead molybdate (PbMoO4) crystal. The piezoelectric crystal of an electroacoustic transducer is lithium niobate (LiNbO3), which uses a reverse piezoelectric effect to generate an ultrasonic field by applying mechanical vibration under the action of an external electric field, thereby converting the modulated electrical signal into an acoustic signal. The role of and driven by the modulation power supply. When the laser passes through the acousto-optic medium, Bragg diffraction occurs due to the interaction of the light and the ultrasonic field, and the first-order diffracted light is output. When the amplitude of the acoustic wave changes with the modulation signal, the intensity of the diffracted light will change accordingly. The output light is periodically modulated light. Here, the modulator also serves as an electro-optical conversion device in the optical path system, that is, converts the graphic information electric signal output by the computer into an optical signal.
2. Modulators in computer-to-plate (CTP) technology Modulators have become indispensable for the transmission of graphic information in printing. Early applications and laser engraving machines, electronic scanning color separation machines, laser photosetters, and laser printers And other equipment. With the development of printing technology, the newly emerged computer-to-plate (CTP) technology, also known as non-film-making, is a high-tech that has been rapidly developed in the 1990s. It is a digitized graphic message processed by the computer and recorded directly on the plate by laser beam modulation scanning. Therefore, the plate making equipment is composed of a computer prepress processing system and a laser plate making machine. Dozens of models have been introduced, and their principles are roughly the same. All of them are computer-controlled laser beam modulation and scanning plate imaging technologies.
Figure 2 shows a Lasertie 100 FLUV laser direct plate making system consisting of an electronic computer, an argon ion (Ar+) laser, an acousto-optic modulator, a multi-faceted rotating mirror, and an Fθ objective lens. The electronic computer delivers an electro-acoustic transducer that processes the digitized graphic information to the acousto-optic modulator. At this point, the laser beam is modulated by the acousto-optic modulator, and its first-order diffracted light is directed to the multi-faceted rotating mirror, and then scanned and exposed by the Fθ objective lens on the printing plate to be directly made into an offset printing plate. The plates produced have the advantages of good quality and high speed.
The commonly used lasers in the CTPlate computer-to-plate technique are argon ion lasers (488 nm) and (514.5 nm), ytterbium-doped yttrium aluminum garnet lasers (1,06 μm), and HeNe lasers (632.8 μm) where an air-cooled argon ion laser is used. Mostly. It can be seen that the computer-to-platemaking technique can omit the intermediate process from the original plate in the traditional printing. Suitable for light and newspaper printing in fast, low-volume production. Further use in formal printing becomes its future development direction. It plays an important role in promoting the modernization of printing.
3. The digital printing of modulators in digital printing technology is based on a relatively sophisticated computer data processing technology. It combines organic technologies such as laser modulation, scanning and imaging with high-tech photosensitive materials and new printing inks, enabling the entire printing process to be realized by computers. Digital integration of control. It is a modern printing system with a completely different concept and process than traditional printing.
The digital printing process flow is shown in Figure 3, in which the laser modulation and scanning imaging technology is mainly applied in the mechanism version. The color separation data signal (monochrome pixel digital signal) is input to the laser controller during the plate making, so that the emission synchronous monochrome laser beam is converted into a screen data signal through RIP. The laser is modulated and scanned on the plate cylinder. After the photosensitive material on the cylinder is sensitized to form a pattern that can absorb ink or toner, it can be printed. With the principle of different plates of photosensitive materials can be roughly divided into two categories: one is the laser electrostatic imaging type. Such as Indigo EPrint1000 and Omuius digital presses. The other type is a silicon-based rubber type offset type. Such as Heidelberg's Quickmaster DIC Kuba and KBA and Sailing Angel's 74 Karat digital presses. The digital printing equipments all have substantially the same laser modulation and scanning imaging system. The system lasers commonly use argon ion lasers and semiconductor lasers, and the acousto-optic modulators of the acousto-optic modulators are lead molybdates (PbMo04) whose electroacoustic transducers are pressed. The transistor is lithium niobate (LiNb03). The modulator is still an important and indispensable core device for transferring graphic information.
IV. Conclusion Digital printing is an important symbol of modern printing. Personalize on-demand printing. That is, the realization of dynamic or variable image printing will have a major impact on the traditional printing process. Another revolution in traditional printing. It involves a variety of high technology such as computer information processing technology, laser technology, materials science and so on. They are a whole organic combination. Therefore, laser technology should also be one of the indispensable high technologies for promoting modern printing.