Color Functioning Method
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FUNCTIONING METHOD
HalfToning, subtractive and additive color In the chart, notice the big difference between the resolution of black and white and color printed material. This is a side effect of the CMYK technology used to create color. Only eight colors can be printed as a single dot (see below). All other colors are produced by grouping several small dots to give the impression of another color. This is called halftoning. Halftoning is very similar to dithering.
A "dot" of a color picture is usually a 5 by 5 matrix of smaller dots. Thus if the single dot resolution of a printer is 1200 to 3000 dpi, it can print a color picture with a resolution of 150 to 200 dpi. The math seems wrong, but printers have been halftoning for a century; they can do magic. If you scan a printed color picture at high resolutions (e.g., over 200 dpi) you will see Moiré and doily patterns in the picture; 150 dpi is usually optimum. On a color display, on the other hand, colors are created by adding varying amounts of the primary red, green and blue shades. This is suggested in the right-hand part of the above diagram, but you must realize that video colors can vary: where you see a red patch in the diagram, imagine it varying from palest to deepest red. A color graphics engineer thinks in terms of continuously varying color addition. Often the term RBG refers to this type of color production. The point here is that when one scans a color picture, one shifts from a color created by CMYK to one generated by RGB. If one prints a digital picture, one shifts the other way. Since the two technologies are fundamentally different, the results one gets may be surprising
These compact, high-speed printers incorporate vertically aligned four-color toner cartridges.
Robust Color Plane Registration Achieved with Fixed Cartridge System The optimal color document environment in offices today requires color laser printers that counter color plane registration problems and provide excellent ease of use. One countermeasure against color plane mis-registration is to fix the position of the toner cartridges, but conventional horizontally structured printer engines force users to shift the toner cartridges in order to fix paper jams. In Canon's proprietary, world's first Four-Color Vertical In-Line Engine, however, the four color toner cartridges (one each for CMYK) are positioned vertically, achieving full-color printing along the shortest possible route within the printer. When the toner runs out, users need only change each of the four toner cartridges. Paper jams can also be easily fixed from the front of the engine simply by shifting down the transfer belt unit. With toner cartridges, the heart of image formation in the printer, fixed in place, the structure as a whole is highly robust for color plane registration. Another strong feature is a faster first-printout time, made possible by the shortest paper path.
Loop Control of the Paper Makes Possible a Vertical Paper Path without Sacrificing Image Quality The main technological difficulty Canon faced in developing the Four-Color Vertical In-Line Engine was the fact that the paper needed to travel upward against the force of gravity. In other words, the paper's own weight would not help the paper movement. Also present was the concern that, by vertically positioning the image-formation unit of the device, including the toner cartridges, overall printer height might have to be increased. To transfer the paper vertically, Canon applied speed-control technology in the areas of the unit where paper is fed from the paper-supply unit to the transfer belt, and where paper travels from the transfer belt to the fixing unit, and also worked with loop-control technologies to smoothly feed the paper through the engine. This is the area in which engineers sought to simultaneously ensure both smooth paper flow and optimal paper positioning for each of the four colors. To minimize the total height of the engine, Canon developed thin toner cartridges, made the fixing unit more compact using our Color IH Fixing Technology, and also created a multi-sheet supply tray inside the paper cassette to minimize the height of the paper-feeding cassette.
Outline of the Paper Loop Control System Paper loop control technology made vertical paper transfer possible. The loop detection sensor ensures smooth paper transfer between components, such as the fixing sleeve, drive roller and photosensitive drum.
Directly Heating the Fixing Material Canon has become the first company in the world to develop a next-generation color induction-heating (IH) fusing technology, which greatly reduces the warm-up time of color laser printers. The color IH Fusing method uses an IH sleeve consisting of a thin metallic film and a rubber layer, which covers the metallic film to ensure uniform color formation of the toners, and a coil installed in the sleeve. When high-frequency electric current runs through the coil, heat is generated in the thin metallic film. This sleeve, which is located close to the toner on the paper, gives off heat, which is rapidly relayed to the system, realizing one-tenth the warm-up time of conventional color laser printers (in-house comparison). The low heat capacity IH sleeve also reduces energy consumption during regular operation by about 70% (in-house comparison) compared with the existing color roller-fixing method. The Color IH Fusing technology significantly reduces the size of the fixing unit and energy consumption in standby mode, and also greatly accelerates the warm-up process
.
Comparison with the Roller Fixing Method With the roller fixing method (bottom illustration), the heater warms the fixing roller, but since the point of heat generation is separated from the point of heating, heat efficiency is low. With Canon's new IH Fusing method (top illustration), electricity is fed through the coil inside the rubber fixing sleeve, raising the temperature of the fixing sleeve itself. The heated rubber achieves an excellent fixing property and raises heat efficiency.
IH Sleeve Offers Excellent Durability During the development of the Color IH Fusing method, ensuring the durability of the metallic fixing sleeve became an issue in terms of its implementation to the fuser unit, but Canon applied its technological know-how to develop solutions and improvements to resolve this problem. The thin metallic sleeve generates heat internally with a highfrequency magnetic field, and this heat alters its property. During operation, the sleeve is rotated, and the part of it that comes into contact with the pressure roller becomes a flat surface. Because fixing takes place on the flattened surface of the originally curved sleeve, mechanical flexure fatigue accumulates on the metal. To gain the durability to withstand these numerous adverse conditions, Canon performed exhaustive metallic materials research, not only in the area of heating characteristics, but also related to mechanical characteristics for dispersing stress. While working on structural improvements in the fixing unit, including sleeve holding methods, Canon was able to develop an IH sleeve fully durable enough to last the 150,000-sheet output lifespan of the unit itself.
Newly Developed High-Power, High-Frequency Inverter With the color IH Fusing system, placing a coil that generates a high-frequency magnetic field inside a metallic sleeve results in an eddy current, heating the sleeve itself. The IH sleeve, with its thin metallic film, heats up very rapidly. Using conventional heat-control methods, this could lead to significant overshooting or undershooting of the target temperature. To resolve this problem, Canon developed a low-loss, high-frequency inverter that controls output in the wide range of 20 kilohertz (kHz) to 50 kHz. By adjusting the frequency, its output power is controlled around a full 1 kilowatt (kW) during ramp up, whereas it is kept minimum to keep the target temperature after warm up, achieving extremely stable temperature control with almost no temperature deviation, despite the low heat capacity of the IH sleeve.
Temperature deviation is relatively large using the roller fixing method (blue line), but with Canon's IH Fusing method (red line), the lowheat-capacity IH sleeve and an originally developed high-frequency inverter control system realize stable temperature control with almost no temperature deviation.
Surface Temperature Maintenance with the Color IH Fusing Method
The Elusive Oil-Free Solution Color printers and copying machines house an oiling unit that oils the fixing roller to protect it from toner stains and sticking paper. This does, however, introduce a number of problems: replenishing the unit can be troublesome, the oil can produce a glossiness on the paper surface that reduces the visibility of small letters and photographs-and thereby reduces the quality of copies and printouts-and oily copies/printouts can be difficult to write on. Canon's S Toner, coupled with our oilless color fusing system, solves these problems.
Canon's S Toner consists of a wax inner layer and polymer outer layer; the wax ingredient does away with the need for an oil-fixing roller. With S Toner, our fine chemical technology has created particles both very fine and homogeneous-unlike other toners that are mechanically pulverized into widely variant shapes. The result is smooth images that replicate reality.
The uniform size of the spherical grains in Canon's S Toner is devised from our unique polymerization technology. Using this technology, monomer is meticulously blended with wax and color materials, and then dispersed into
.
polymer particles
Four Colors in One Printer Pass In 1998, we introduced a printer engine that used an intermediate transfer body to affix four colors of toner (magenta, cyan, yellow and black) on one pass of sheet transport. This intermediate transfer system eliminates the need to fasten paper around the transfer drum and print each color separately. Color plane registration is also assured, giving color output of unprecedented beauty. A horizontal paper path mobile roller-and no paper fastening around the transfer drum-extends the application range of the system to encompass printing on thick paper, such as postcards, and on A3-sized paper (297 mm x 420 mm
Printer Engine Following color separation consistent with the original image, each of the four colors (magenta, cyan, yellow and black) is printed onto the intermediate transfer body. The full-color image is then transferred in one printer pass. The paper moves horizontally, and no paper fastening around the
.
transfer drum is required
).
S Toner Evolved from a Flexible Way of Thinking Why not make toner chemically instead of through conventional pulverization? This flexible way of thinking spurred the development of Canon's S Toner. Repeated trial and error was nonetheless required before we achieved a practical production process for this new-age toner. Among the numerous difficulties to overcome were finding the best way to uniformly disperse toner materials and achieve compatibility between the wax and polymer. This innovation necessitated the development of our first chemical plant. Such a scale-up of mass-production gives rise to difficulties in general, howeber, the inclusion of a polymerization process and the simultaneous development of three colors (yellow, cyan and magenta) magnified the complexity ,which we have overcome at least.
HalfToning, subtractive and additive color In the chart, notice the big difference between the resolution of black and white and color printed material. This is a side effect of the CMYK technology used to create color. Only eight colors can be printed as a single dot (see below). All other colors are produced by grouping several small dots to give the impression of another color. This is called halftoning. Halftoning is very similar to dithering.
A "dot" of a color picture is usually a 5 by 5 matrix of smaller dots. Thus if the single dot resolution of a printer is 1200 to 3000 dpi, it can print a color picture with a resolution of 150 to 200 dpi. The math seems wrong, but printers have been halftoning for a century; they can do magic. If you scan a printed color picture at high resolutions (e.g., over 200 dpi) you will see Moiré and doily patterns in the picture; 150 dpi is usually optimum. On a color display, on the other hand, colors are created by adding varying amounts of the primary red, green and blue shades. This is suggested in the right-hand part of the above diagram, but you must realize that video colors can vary: where you see a red patch in the diagram, imagine it varying from palest to deepest red. A color graphics engineer thinks in terms of continuously varying color addition. Often the term RBG refers to this type of color production. The point here is that when one scans a color picture, one shifts from a color created by CMYK to one generated by RGB. If one prints a digital picture, one shifts the other way. Since the two technologies are fundamentally different, the results one gets may be surprising
These compact, high-speed printers incorporate vertically aligned four-color toner cartridges.
Robust Color Plane Registration Achieved with Fixed Cartridge System The optimal color document environment in offices today requires color laser printers that counter color plane registration problems and provide excellent ease of use. One countermeasure against color plane mis-registration is to fix the position of the toner cartridges, but conventional horizontally structured printer engines force users to shift the toner cartridges in order to fix paper jams. In Canon's proprietary, world's first Four-Color Vertical In-Line Engine, however, the four color toner cartridges (one each for CMYK) are positioned vertically, achieving full-color printing along the shortest possible route within the printer. When the toner runs out, users need only change each of the four toner cartridges. Paper jams can also be easily fixed from the front of the engine simply by shifting down the transfer belt unit. With toner cartridges, the heart of image formation in the printer, fixed in place, the structure as a whole is highly robust for color plane registration. Another strong feature is a faster first-printout time, made possible by the shortest paper path.
Loop Control of the Paper Makes Possible a Vertical Paper Path without Sacrificing Image Quality The main technological difficulty Canon faced in developing the Four-Color Vertical In-Line Engine was the fact that the paper needed to travel upward against the force of gravity. In other words, the paper's own weight would not help the paper movement. Also present was the concern that, by vertically positioning the image-formation unit of the device, including the toner cartridges, overall printer height might have to be increased. To transfer the paper vertically, Canon applied speed-control technology in the areas of the unit where paper is fed from the paper-supply unit to the transfer belt, and where paper travels from the transfer belt to the fixing unit, and also worked with loop-control technologies to smoothly feed the paper through the engine. This is the area in which engineers sought to simultaneously ensure both smooth paper flow and optimal paper positioning for each of the four colors. To minimize the total height of the engine, Canon developed thin toner cartridges, made the fixing unit more compact using our Color IH Fixing Technology, and also created a multi-sheet supply tray inside the paper cassette to minimize the height of the paper-feeding cassette.
Outline of the Paper Loop Control System Paper loop control technology made vertical paper transfer possible. The loop detection sensor ensures smooth paper transfer between components, such as the fixing sleeve, drive roller and photosensitive drum.
Directly Heating the Fixing Material Canon has become the first company in the world to develop a next-generation color induction-heating (IH) fusing technology, which greatly reduces the warm-up time of color laser printers. The color IH Fusing method uses an IH sleeve consisting of a thin metallic film and a rubber layer, which covers the metallic film to ensure uniform color formation of the toners, and a coil installed in the sleeve. When high-frequency electric current runs through the coil, heat is generated in the thin metallic film. This sleeve, which is located close to the toner on the paper, gives off heat, which is rapidly relayed to the system, realizing one-tenth the warm-up time of conventional color laser printers (in-house comparison). The low heat capacity IH sleeve also reduces energy consumption during regular operation by about 70% (in-house comparison) compared with the existing color roller-fixing method. The Color IH Fusing technology significantly reduces the size of the fixing unit and energy consumption in standby mode, and also greatly accelerates the warm-up process
.
Comparison with the Roller Fixing Method With the roller fixing method (bottom illustration), the heater warms the fixing roller, but since the point of heat generation is separated from the point of heating, heat efficiency is low. With Canon's new IH Fusing method (top illustration), electricity is fed through the coil inside the rubber fixing sleeve, raising the temperature of the fixing sleeve itself. The heated rubber achieves an excellent fixing property and raises heat efficiency.
IH Sleeve Offers Excellent Durability During the development of the Color IH Fusing method, ensuring the durability of the metallic fixing sleeve became an issue in terms of its implementation to the fuser unit, but Canon applied its technological know-how to develop solutions and improvements to resolve this problem. The thin metallic sleeve generates heat internally with a highfrequency magnetic field, and this heat alters its property. During operation, the sleeve is rotated, and the part of it that comes into contact with the pressure roller becomes a flat surface. Because fixing takes place on the flattened surface of the originally curved sleeve, mechanical flexure fatigue accumulates on the metal. To gain the durability to withstand these numerous adverse conditions, Canon performed exhaustive metallic materials research, not only in the area of heating characteristics, but also related to mechanical characteristics for dispersing stress. While working on structural improvements in the fixing unit, including sleeve holding methods, Canon was able to develop an IH sleeve fully durable enough to last the 150,000-sheet output lifespan of the unit itself.
Newly Developed High-Power, High-Frequency Inverter With the color IH Fusing system, placing a coil that generates a high-frequency magnetic field inside a metallic sleeve results in an eddy current, heating the sleeve itself. The IH sleeve, with its thin metallic film, heats up very rapidly. Using conventional heat-control methods, this could lead to significant overshooting or undershooting of the target temperature. To resolve this problem, Canon developed a low-loss, high-frequency inverter that controls output in the wide range of 20 kilohertz (kHz) to 50 kHz. By adjusting the frequency, its output power is controlled around a full 1 kilowatt (kW) during ramp up, whereas it is kept minimum to keep the target temperature after warm up, achieving extremely stable temperature control with almost no temperature deviation, despite the low heat capacity of the IH sleeve.
Temperature deviation is relatively large using the roller fixing method (blue line), but with Canon's IH Fusing method (red line), the lowheat-capacity IH sleeve and an originally developed high-frequency inverter control system realize stable temperature control with almost no temperature deviation.
Surface Temperature Maintenance with the Color IH Fusing Method
The Elusive Oil-Free Solution Color printers and copying machines house an oiling unit that oils the fixing roller to protect it from toner stains and sticking paper. This does, however, introduce a number of problems: replenishing the unit can be troublesome, the oil can produce a glossiness on the paper surface that reduces the visibility of small letters and photographs-and thereby reduces the quality of copies and printouts-and oily copies/printouts can be difficult to write on. Canon's S Toner, coupled with our oilless color fusing system, solves these problems.
Canon's S Toner consists of a wax inner layer and polymer outer layer; the wax ingredient does away with the need for an oil-fixing roller. With S Toner, our fine chemical technology has created particles both very fine and homogeneous-unlike other toners that are mechanically pulverized into widely variant shapes. The result is smooth images that replicate reality.
The uniform size of the spherical grains in Canon's S Toner is devised from our unique polymerization technology. Using this technology, monomer is meticulously blended with wax and color materials, and then dispersed into
.
polymer particles
Four Colors in One Printer Pass In 1998, we introduced a printer engine that used an intermediate transfer body to affix four colors of toner (magenta, cyan, yellow and black) on one pass of sheet transport. This intermediate transfer system eliminates the need to fasten paper around the transfer drum and print each color separately. Color plane registration is also assured, giving color output of unprecedented beauty. A horizontal paper path mobile roller-and no paper fastening around the transfer drum-extends the application range of the system to encompass printing on thick paper, such as postcards, and on A3-sized paper (297 mm x 420 mm
Printer Engine Following color separation consistent with the original image, each of the four colors (magenta, cyan, yellow and black) is printed onto the intermediate transfer body. The full-color image is then transferred in one printer pass. The paper moves horizontally, and no paper fastening around the
.
transfer drum is required
).
S Toner Evolved from a Flexible Way of Thinking Why not make toner chemically instead of through conventional pulverization? This flexible way of thinking spurred the development of Canon's S Toner. Repeated trial and error was nonetheless required before we achieved a practical production process for this new-age toner. Among the numerous difficulties to overcome were finding the best way to uniformly disperse toner materials and achieve compatibility between the wax and polymer. This innovation necessitated the development of our first chemical plant. Such a scale-up of mass-production gives rise to difficulties in general, howeber, the inclusion of a polymerization process and the simultaneous development of three colors (yellow, cyan and magenta) magnified the complexity ,which we have overcome at least.
