Section I: Photographic platemaking process. Photographic platemaking process.
(1) Device original. The original to be produced is set to the center of the large document holder.
(2) Magnification settings. According to the copying requirement, the original zoom ratio is calculated and set on the camera.
(3) The light. Install frosted glass on the photographic plate, turn on the power, focus on the frosted glass with the maximum aperture, find the clearest image of the original, and make the original size correct and centered.
The adjustment of the focal length and the object distance in the light is performed according to the lens formula, that is, after the light is finished, the light is turned off, the aperture is adjusted, and the lens cap is closed. Thin line drawings and texts mostly use a 1:9 aperture.
(4) Exposure. Select high-contrast photosensitive film, the photosensitive film surface facing the lens into the photosensitive plate, open the light source, open the lens cover, exposure.
(5) The exposure time is proportional to the distance between the magnification of the original and the light distance, and inversely proportional to the size of the aperture and the angle of the light. In addition, it is necessary to master the characteristics of the original document.
(6) Development.
(7) Fixing.
The production of two monochrome linework positive figures. Photo negatives (negative images) must be remade or copied. Make it the same positive image as the original image (positive image) to meet the plate-making requirements. (1) Photocopying method. The photographed negative is used as a transmissive original, and the device is placed on the original holder of the camera. If the positive figure is used for printing, the photosensitive emulsion should be placed facing away from the lens. After exposure, development, and fixing, positive images for printing plates can be obtained. Figure (2) Copying method: Photographed original negative emulsion is placed on a copy glass plate (see figure) facing upwards. When copying, the emulsion of the photosensitive film is faced down to the negative emulsion surface, and the suction is sealed and exposed. After developing and fixing, a positive image for printing can be obtained.
Three Monochrome Continually Tuned Original Photographic Platemaking Process. For the continuous adjustment of the original to be screen processing, the continuous transfer image into a network of images, for monochrome manuscripts, can be screen plus screen (see figure), but also for copy screening. The photographic screening is to place the screen before the photosensitive film; the copy screening is to place the contact screen between the photosensitive material and the continuous tone chart for copying.
Section II: Photo separation process for color continuous-tone originals Photo-engraving for color continuous-tone originals has two processes, indirect color screening and direct screen color separation. An indirect screening color separation process. Indirect screening refers to separation and screening for platemaking processes, as shown in the figure. (1) Photographic plate making process of color separation plus positive image. First of all, add a color filter in front of the camera's lens, use a full-color photo film to separate color, make a color separation Yin picture. To make a color separation picture, use the following color filter:
Yellow Edition: Blue filter.
Magenta version: with a green filter.
Cyan version: Use red filters.
Black version: Yellow filter or segmented exposure with red, green and blue filters. Which method is used depends on the hue of the original.
The color separation shading film was modified and installed on the original document holder of the camera, and on the screen frame of the camera, the glass screen was installed, and the positive photosensitive film was used to make the positive image of the screen. FIG. Copy screening can also be performed.
The screen angles of the positive screens for various colors are generally:
Yellow Edition: 90°=0°
Magenta version (small blue version): 15°=105°
Qing plate (red version): 75°=165°
Black plate (gray plate): 45°=135° (2) Photographic plate making process of color separation and screen printing. The production of color separation and screen negatives adopts the same color filter and network line angle as the color separation plus network positive image. Only after the continuous tone chart is made of the original, it is first converted into a continuous positive adjustment chart. After the correction, the screen is screened again to obtain the color separation screen (see the figure). There are many opportunities for correcting the indirect screening color separation method, and the plate making effect is easy to control, but the operation is more complicated. Due to the large number of photographs or the number of copies, the definition of the image may be affected to varying degrees. (3) Manual revision. Photographic plates are often used to manually modify the method to enhance or reduce the density of negative and positive images, respectively, with black ink coating and corrosion method to complete. This is a remedial process in photolithography. Taking the revision of the color separation negative image as an example, the effect of coating the black ink is to increase the density of the opposite color portion on the color separation negative image, that is, the color amount of this portion is reduced in accordance with the original document in various degrees, and the converse is increased. The proportion of the basic color, in order to obtain the balance with the basic color system tone.
The erosion of the negative image is just the opposite of applying the black ink, that is, increasing the density of the basic color portion on the negative image, and objectively playing a role of relatively reducing the proportion of the opposite color. The main components of the etching solution used for correction of the film are red blood and soda, and the corrosion principle is:
Two direct screen color separation (hanging process). Direct Screening is a platemaking process in which screens are screened at the same time as color separation through contact screens or glass screens. as the picture shows. The direct screen color separation method reduces the number of photographs, shortens the plate making time, and improves the sharpness of the image. However, the level reproduction step is indirect and indirect, especially the dark tone adjustment. (1) Mask production. The masks used in direct color separation and screening are mostly colored masks, which can both correct the color and correct the level. After it is mounted on the camera, the color separation does not need to be replaced, and it is easy to register. The production of the mask is shown in the figure, and the color is used as an example. The main production process is shown in the figure. (2) The manuscript and the color cover are placed on the transmissive original holder of the camera, a color filter is installed in front of the light source, and a photosensitive film and a contact screen are arranged on the image forming surface. As shown in the figure, the image is developed and fixed by the exposure, that is, Score color plus net negative film. (3) Direct-screen color separation requires the use of a high-magnification, short-focus zoom lens such as EL-NIKKON. The number of screen lines depends on the printing conditions and the paper used, typically 150 lines/inch or 175/inch. For cable angles, the most prominent color version is generally set to 45°, and the Other two color versions are different from each other by 30°. The inconspicuous yellow plate angle can be inserted between these angles by 15°. For example: Black Edition: 15 °, Magenta version: 45°, Cyan version: 75°, Yellow version: 30° or 90°, Black version: 15°, Magenta version: 75°, Cyan version: 45°. Yellow Edition: 30° or 90°;
Kodak's color filters are often used for color filters. In addition, the laminated film and mask should be punched so as to register with the positioning pin. (4) Auxiliary exposure. In order to obtain all shaded halftone dot negatives, in addition to performing exposure through the screen to establish the basic reproduction of the original layer, auxiliary exposure is also required.
1 Flash exposure. Through the screen, but not through the lens, give a slight and even full-scale exposure. You can make up the minimum point in the dark tone to extend the dark tone of the halftone tone to the midtone tone.
2 High light exposure. After the main exposure and flash exposure are completed, the screen is removed, and as with the main exposure, the light is exposed through the lens to expose the original, and the exposure amount is only 2-6% of the main exposure to improve the highlight contrast of the original. (5) Back color removal in the direct color separation screening process. For a high-contrast natural color original, a special hard full-color film can be used to produce a base color removal mask using a contact exposure method. The density of the solid portion corresponding to the original on the under color removal mask is higher.
After the main exposure is completed by direct color separation screening, the natural color mask and the color correction mask are removed from the document holder, the mask is removed by the background color removal, and the trace exposure is performed through the mask to remove the mask pair with the background color. The dark part of the flash exposure, to control the dark part of the network. Section 2 Electronic Separation Process Electronic Separation is the process of decomposing colored originals into monochrome versions using electronic scanning.
Electronic color separation machine referred to as electric extension. It is a device that decomposes color originals into monochrome versions using electronic scanning separation. Is a combination of optical, mechanical, electronic technology and computer precision plate making equipment. The color separation of the manuscript is performed by using the original scanning drum and the film cylinder to make a circle rotation, and the scanning head and the recording head make a horizontal movement, and the principle of mechanical point by point scanning and exposure is realized. The color separation of the electronic color separation machine is different from that of the photoengraving process, but it is performed on a point-by-point basis. Therefore, to understand the principle of the electronic color separation machine, it is important to transfer the image information at a certain point on the original document to the photosensitive sheet. The process to understand the principle of electronic color separation machine. The image information of a certain point on the basic manuscript of the electronic color separation machine is transmitted to the photosensitive sheet to understand the principle of the electronic color separation machine. The basic structure of the electronic color separation machine is as shown in the figure. When an original attached to a scanning roller rotates along with the scanning roller, the light emitted from the light source hits the original, and then enters the optical system of the scanning head, and after the spectroscopic processing, The separated three beams of light are filtered by a color filter and then irradiated to the corresponding three photomultiplier tubes and converted into corresponding electronic signals, that is, yellow, magenta, and cyan main signals. A photomultiplier tube is a photoelectric conversion device that converts a very weak light signal it receives into an electrical signal that is amplified by millions of times. The three-way color separation main signal converted by the photomultiplier tube is amplified and then entered into a color computer to generate a color correction signal, and the color separation main signal is calibrated for each channel. After the color correction, the main signal is generated by the black version of the computer, and at the same time, the color separation main signal is subjected to background color removal and non-color structure calculation, and then enters the level correction circuit to perform level correction, and then the virtual optical signal is emphasized in detail. . Finally, the four color-coded versions of the electrical signals enter the proportional computer and the image is scaled up or down. The laser beam generated by the dot generator is recorded on the photosensitive film to complete the process of the entire color separation and screening process. The process flow of the second extension is as follows:
Color manuscript pixel scan color decomposition photoelectric conversion simulation computer calculation (including color correction, gradation correction, background color removal, fine gradation adjustment, film density calibration) Proportional computer calculation (enlargement, reduction) Electro-optic conversion (reduction of electrical signals into optical signals) The record exposure electronic color separation process can be divided into three major steps:
Image signal scan input computer processing electronic screening record output. 1 Image signal scan input. The commonly used electric extension is a typical mechanical scanning for document acquisition and input. The scanning input system is mainly composed of a scanning roller, a scanning light source and a scanning head.
In the high-speed rotation of the scanning drum, the scanning light source illuminates the original document point by point, and the light transmitted or reflected by the original document is collected by the scanning head, and after completing a one-week scanning, the scanning head is moved laterally by the stepping motor to start scanning the next week. After the collected light information enters the scanning head, the light separation, color separation, and photoelectric conversion are performed to obtain a color separation signal. 2 Computer processing. The heart of the electronic color separation machine is a color computer (referred to as a color machine). It consists of a variety of different circuits and can perform a variety of operations. Through these operating circuits, the optically-electrically converted electrical signals are compensated and corrected to meet the requirements of plate-making color separation. The special feature of color machine work is to separate colors, levels, sharpness, etc. and adjust them individually. These correction functions are controlled by knobs and buttons on the operation panel, as long as the correct operation process is very simple and easy, and it is conducive to data control. Its main functions are as follows: (1) Color correction. Correct color misalignment of the original or meet the special requirements of customers; correct errors caused by materials such as inks, color filters, and other processes and system colors. (2) Adjustment of tone levels. The relationship between the density range of the original and the dot area ratio of the dot dichroic sheet (original) can be changed. (3) Sharpness enhancement. Because the contrast is compressed in the original copy printing, the sharpness will be greatly reduced (the number of lines in the printed product is mostly between 60-80 lines/cm), so some fine contrast in the original may be lost. On the extensions, there are subtle levels of emphasis to enhance the clarity of prints. (4) Non-color structure. It is similar to photolithographic masking. But use the computer to process the signal. (5) Zoom the image. Using a proportional computer to process the input signal, an output signal that meets the scaling requirements can be obtained to complete the scaling task. 3 electronic screening record output. It differs from photo-making in the biggest difference in the way of dot generation. Electronic screening uses point-by-point exposure of one or more lasers on a film to obtain dot images. There are two types of recording heads: outer roller exposure (see figure) and inner roller exposure (see figure). Section 3 Color Desktop Publishing System Section 1 Color Revolution in the Printing Industry I. The Concept of a Color Desktop Publishing System
(1) Device original. The original to be produced is set to the center of the large document holder.
(2) Magnification settings. According to the copying requirement, the original zoom ratio is calculated and set on the camera.
(3) The light. Install frosted glass on the photographic plate, turn on the power, focus on the frosted glass with the maximum aperture, find the clearest image of the original, and make the original size correct and centered.
The adjustment of the focal length and the object distance in the light is performed according to the lens formula, that is, after the light is finished, the light is turned off, the aperture is adjusted, and the lens cap is closed. Thin line drawings and texts mostly use a 1:9 aperture.
(4) Exposure. Select high-contrast photosensitive film, the photosensitive film surface facing the lens into the photosensitive plate, open the light source, open the lens cover, exposure.
(5) The exposure time is proportional to the distance between the magnification of the original and the light distance, and inversely proportional to the size of the aperture and the angle of the light. In addition, it is necessary to master the characteristics of the original document.
(6) Development.
(7) Fixing.
The production of two monochrome linework positive figures. Photo negatives (negative images) must be remade or copied. Make it the same positive image as the original image (positive image) to meet the plate-making requirements. (1) Photocopying method. The photographed negative is used as a transmissive original, and the device is placed on the original holder of the camera. If the positive figure is used for printing, the photosensitive emulsion should be placed facing away from the lens. After exposure, development, and fixing, positive images for printing plates can be obtained. Figure (2) Copying method: Photographed original negative emulsion is placed on a copy glass plate (see figure) facing upwards. When copying, the emulsion of the photosensitive film is faced down to the negative emulsion surface, and the suction is sealed and exposed. After developing and fixing, a positive image for printing can be obtained.
Three Monochrome Continually Tuned Original Photographic Platemaking Process. For the continuous adjustment of the original to be screen processing, the continuous transfer image into a network of images, for monochrome manuscripts, can be screen plus screen (see figure), but also for copy screening. The photographic screening is to place the screen before the photosensitive film; the copy screening is to place the contact screen between the photosensitive material and the continuous tone chart for copying.
Section II: Photo separation process for color continuous-tone originals Photo-engraving for color continuous-tone originals has two processes, indirect color screening and direct screen color separation. An indirect screening color separation process. Indirect screening refers to separation and screening for platemaking processes, as shown in the figure. (1) Photographic plate making process of color separation plus positive image. First of all, add a color filter in front of the camera's lens, use a full-color photo film to separate color, make a color separation Yin picture. To make a color separation picture, use the following color filter:
Yellow Edition: Blue filter.
Magenta version: with a green filter.
Cyan version: Use red filters.
Black version: Yellow filter or segmented exposure with red, green and blue filters. Which method is used depends on the hue of the original.
The color separation shading film was modified and installed on the original document holder of the camera, and on the screen frame of the camera, the glass screen was installed, and the positive photosensitive film was used to make the positive image of the screen. FIG. Copy screening can also be performed.
The screen angles of the positive screens for various colors are generally:
Yellow Edition: 90°=0°
Magenta version (small blue version): 15°=105°
Qing plate (red version): 75°=165°
Black plate (gray plate): 45°=135° (2) Photographic plate making process of color separation and screen printing. The production of color separation and screen negatives adopts the same color filter and network line angle as the color separation plus network positive image. Only after the continuous tone chart is made of the original, it is first converted into a continuous positive adjustment chart. After the correction, the screen is screened again to obtain the color separation screen (see the figure). There are many opportunities for correcting the indirect screening color separation method, and the plate making effect is easy to control, but the operation is more complicated. Due to the large number of photographs or the number of copies, the definition of the image may be affected to varying degrees. (3) Manual revision. Photographic plates are often used to manually modify the method to enhance or reduce the density of negative and positive images, respectively, with black ink coating and corrosion method to complete. This is a remedial process in photolithography. Taking the revision of the color separation negative image as an example, the effect of coating the black ink is to increase the density of the opposite color portion on the color separation negative image, that is, the color amount of this portion is reduced in accordance with the original document in various degrees, and the converse is increased. The proportion of the basic color, in order to obtain the balance with the basic color system tone.
The erosion of the negative image is just the opposite of applying the black ink, that is, increasing the density of the basic color portion on the negative image, and objectively playing a role of relatively reducing the proportion of the opposite color. The main components of the etching solution used for correction of the film are red blood and soda, and the corrosion principle is:
Two direct screen color separation (hanging process). Direct Screening is a platemaking process in which screens are screened at the same time as color separation through contact screens or glass screens. as the picture shows. The direct screen color separation method reduces the number of photographs, shortens the plate making time, and improves the sharpness of the image. However, the level reproduction step is indirect and indirect, especially the dark tone adjustment. (1) Mask production. The masks used in direct color separation and screening are mostly colored masks, which can both correct the color and correct the level. After it is mounted on the camera, the color separation does not need to be replaced, and it is easy to register. The production of the mask is shown in the figure, and the color is used as an example. The main production process is shown in the figure. (2) The manuscript and the color cover are placed on the transmissive original holder of the camera, a color filter is installed in front of the light source, and a photosensitive film and a contact screen are arranged on the image forming surface. As shown in the figure, the image is developed and fixed by the exposure, that is, Score color plus net negative film. (3) Direct-screen color separation requires the use of a high-magnification, short-focus zoom lens such as EL-NIKKON. The number of screen lines depends on the printing conditions and the paper used, typically 150 lines/inch or 175/inch. For cable angles, the most prominent color version is generally set to 45°, and the Other two color versions are different from each other by 30°. The inconspicuous yellow plate angle can be inserted between these angles by 15°. For example: Black Edition: 15 °, Magenta version: 45°, Cyan version: 75°, Yellow version: 30° or 90°, Black version: 15°, Magenta version: 75°, Cyan version: 45°. Yellow Edition: 30° or 90°;
Kodak's color filters are often used for color filters. In addition, the laminated film and mask should be punched so as to register with the positioning pin. (4) Auxiliary exposure. In order to obtain all shaded halftone dot negatives, in addition to performing exposure through the screen to establish the basic reproduction of the original layer, auxiliary exposure is also required.
1 Flash exposure. Through the screen, but not through the lens, give a slight and even full-scale exposure. You can make up the minimum point in the dark tone to extend the dark tone of the halftone tone to the midtone tone.
2 High light exposure. After the main exposure and flash exposure are completed, the screen is removed, and as with the main exposure, the light is exposed through the lens to expose the original, and the exposure amount is only 2-6% of the main exposure to improve the highlight contrast of the original. (5) Back color removal in the direct color separation screening process. For a high-contrast natural color original, a special hard full-color film can be used to produce a base color removal mask using a contact exposure method. The density of the solid portion corresponding to the original on the under color removal mask is higher.
After the main exposure is completed by direct color separation screening, the natural color mask and the color correction mask are removed from the document holder, the mask is removed by the background color removal, and the trace exposure is performed through the mask to remove the mask pair with the background color. The dark part of the flash exposure, to control the dark part of the network. Section 2 Electronic Separation Process Electronic Separation is the process of decomposing colored originals into monochrome versions using electronic scanning.
Electronic color separation machine referred to as electric extension. It is a device that decomposes color originals into monochrome versions using electronic scanning separation. Is a combination of optical, mechanical, electronic technology and computer precision plate making equipment. The color separation of the manuscript is performed by using the original scanning drum and the film cylinder to make a circle rotation, and the scanning head and the recording head make a horizontal movement, and the principle of mechanical point by point scanning and exposure is realized. The color separation of the electronic color separation machine is different from that of the photoengraving process, but it is performed on a point-by-point basis. Therefore, to understand the principle of the electronic color separation machine, it is important to transfer the image information at a certain point on the original document to the photosensitive sheet. The process to understand the principle of electronic color separation machine. The image information of a certain point on the basic manuscript of the electronic color separation machine is transmitted to the photosensitive sheet to understand the principle of the electronic color separation machine. The basic structure of the electronic color separation machine is as shown in the figure. When an original attached to a scanning roller rotates along with the scanning roller, the light emitted from the light source hits the original, and then enters the optical system of the scanning head, and after the spectroscopic processing, The separated three beams of light are filtered by a color filter and then irradiated to the corresponding three photomultiplier tubes and converted into corresponding electronic signals, that is, yellow, magenta, and cyan main signals. A photomultiplier tube is a photoelectric conversion device that converts a very weak light signal it receives into an electrical signal that is amplified by millions of times. The three-way color separation main signal converted by the photomultiplier tube is amplified and then entered into a color computer to generate a color correction signal, and the color separation main signal is calibrated for each channel. After the color correction, the main signal is generated by the black version of the computer, and at the same time, the color separation main signal is subjected to background color removal and non-color structure calculation, and then enters the level correction circuit to perform level correction, and then the virtual optical signal is emphasized in detail. . Finally, the four color-coded versions of the electrical signals enter the proportional computer and the image is scaled up or down. The laser beam generated by the dot generator is recorded on the photosensitive film to complete the process of the entire color separation and screening process. The process flow of the second extension is as follows:
Color manuscript pixel scan color decomposition photoelectric conversion simulation computer calculation (including color correction, gradation correction, background color removal, fine gradation adjustment, film density calibration) Proportional computer calculation (enlargement, reduction) Electro-optic conversion (reduction of electrical signals into optical signals) The record exposure electronic color separation process can be divided into three major steps:
Image signal scan input computer processing electronic screening record output. 1 Image signal scan input. The commonly used electric extension is a typical mechanical scanning for document acquisition and input. The scanning input system is mainly composed of a scanning roller, a scanning light source and a scanning head.
In the high-speed rotation of the scanning drum, the scanning light source illuminates the original document point by point, and the light transmitted or reflected by the original document is collected by the scanning head, and after completing a one-week scanning, the scanning head is moved laterally by the stepping motor to start scanning the next week. After the collected light information enters the scanning head, the light separation, color separation, and photoelectric conversion are performed to obtain a color separation signal. 2 Computer processing. The heart of the electronic color separation machine is a color computer (referred to as a color machine). It consists of a variety of different circuits and can perform a variety of operations. Through these operating circuits, the optically-electrically converted electrical signals are compensated and corrected to meet the requirements of plate-making color separation. The special feature of color machine work is to separate colors, levels, sharpness, etc. and adjust them individually. These correction functions are controlled by knobs and buttons on the operation panel, as long as the correct operation process is very simple and easy, and it is conducive to data control. Its main functions are as follows: (1) Color correction. Correct color misalignment of the original or meet the special requirements of customers; correct errors caused by materials such as inks, color filters, and other processes and system colors. (2) Adjustment of tone levels. The relationship between the density range of the original and the dot area ratio of the dot dichroic sheet (original) can be changed. (3) Sharpness enhancement. Because the contrast is compressed in the original copy printing, the sharpness will be greatly reduced (the number of lines in the printed product is mostly between 60-80 lines/cm), so some fine contrast in the original may be lost. On the extensions, there are subtle levels of emphasis to enhance the clarity of prints. (4) Non-color structure. It is similar to photolithographic masking. But use the computer to process the signal. (5) Zoom the image. Using a proportional computer to process the input signal, an output signal that meets the scaling requirements can be obtained to complete the scaling task. 3 electronic screening record output. It differs from photo-making in the biggest difference in the way of dot generation. Electronic screening uses point-by-point exposure of one or more lasers on a film to obtain dot images. There are two types of recording heads: outer roller exposure (see figure) and inner roller exposure (see figure). Section 3 Color Desktop Publishing System Section 1 Color Revolution in the Printing Industry I. The Concept of a Color Desktop Publishing System
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