Technology Used in Laser Printers/Laser Multifunction Printers
To meet the demands of the times, Canon continues to develop laser printer/laser multifunction printer (MFP) products while striving not only to improve such basic performance aspects as image quality, speed, and ease of use, but also providing network compatibility, extensibility, and eco-friendly performance.
The Electrophotographic Printing Process
Laser printers/laser multifunction printers (MFPs), office multifunction devices (MFDs), and digital production printing systems all employ the same printing principle.
- * Most color models use a transfer system in which the toner first transfers from the photosensitive drum to an intermediate transfer belt, then from the belt to the paper.
A System for Freely Combining Functions for Sundry Devices, from Single-Function to Multi-Function
Canon has developed a lightweight, compact architecture for product development. With this architecture, product developers can freely combine devices, operation panels, and capabilities into a full range of products, from single-function to multifunction printers, at low cost and in short development cycles.
The configuration-free architecture groups individual devices and functions into block structures that can be flexibly combined together into larger, more elaborate structures for the creation of various models. The blocks are also interchangeable and can be diverted from one structure to another to improve both development efficiency and product quality. This development environment also supports enhancements for mobile printing, authentication, and more advanced functions.
Canon's configuration-free architecture is equipped with a completely isolated language-dependent block capable of supporting product development in more than 30 languages.
Conceptual Diagram of Configuration-Free Architecture
Pad Transfer High-Image-Quality Technology
Electric Field Control Technology for Simple Architecture and Improved Image Quality
Color laser printer/MFP images are formed when the yellow, magenta, cyan, and black toner image on a photosensitive drum is initially transferred onto an intermediate transfer belt in succession and the four colors are layered on top of one another. In the past, a positive charge was applied to the transfer roller to cause the negatively charged toner to transfer onto the belt.
In Canon's newly developed Pad Transfer High-Image-Quality Technology, a pad and special electrical conductive sheet with low friction resistance convey toner onto the intermediate transfer belt for the primary transfer. With conventional rollers, it was necessary to add extra components or make the roller bigger to prevent toner from scattering due to such phenomena as delamination discharge.
Canon's Pad Transfer High-Image-Quality Technology uses an electrical conductive sheet to eliminate the need for additional components, achieving a small, simple configuration. Applying a positive charge to the sheet draws the negatively charged toner onto the intermediate transfer belt without scattering toner for the printing of text that is sharp and clear. Less electrical resistance in the sheet makes possible a 90% decrease in voltage needed for transfer, contributing to a smaller overall printer size and lower costs.
Pad Transfer High-Image-Quality Technology
Automatic Media Sensing Technology
Automatically Determining Media Type for Optimal Print Settings
Laser printers/MFPs are used not only for printing on paper, but also on a wide variety of media, including resin film. Because the optimal amount of heat used to fix toner to the media varies depending on the media type, users must select the type of media they are using via a computer or from the printer's control panel. If the right amount of heat isn't applied, the four colors of toner—cyan, magenta, yellow and black—will not fully fuse to the media, resulting in poor image quality or printout that peels easily.
Canon's newly developed automatic media sensing technology eliminates the inconvenience of changing printer settings manually, along with the risk of compromised print quality caused by configuration errors.
First, the surface of the media fed from the tray is illuminated by an LED and photographed by a CMOS sensor. Next, the reverse side of the media is illuminated by an LED, and its transparency is measured. The obtained data is compared to data stored inside the printer's library, and the printer automatically determines which of seven types of media*1 is being used, enabling printing with optimal settings based on the media type.
CMOS Sensor and Controller IC
Overview of Automatic Media Sensing Technology
Media Surface Images
Because there are many different types of print media, the data library used to automatically determine the media was made by analyzing the surface images of several thousand media types. Laser printers/MFPs with automatic media sensing technology offer stable, high-image-quality-print performance regardless of the media used, and without inconvenience to the user.
- *1 Seven types of media
Normal paper, bond paper (high-quality paper used for stamps, stock certificates and high-end office stationery), thin paper, thick paper, glossy paper (glossy paper used for photo prints), glossy film (glossy resin film), and OHT (clear resin film used in overhead projectors).
Ultra-Compact Design Technology
Reducing Height to Realize Slim Color Laser Printers/MFPs
Canon has engaged in a variety of technical overhauls in response to the need for compact-size laser printers/MFPs, which are often located on or near desktops in office environments. Canon's Ultra-Compact Design Technology, responsible for the realization of ultra-slim A4 color laser printers/MFPs measuring 262 mm in height, is a composite of different technologies that contribute to smaller, slimmer designs.
4-in-1 Ultra-Slim Laser Scanner
In conventional laser scanners, each of the four photosensitive drums requires a laser scanner. Canon's 4-in-1 Laser Scanner is a single scanner unit that projects four color laser beams onto a polygon mirror at oblique angles, splitting the light path into four directions to guide each beam towards its respective photosensitive drum. Positioning the polygon mirror at a low level in the center of the scanner unit and meticulously designing the paths of the beams made possible the 4-in-1 Ultra-Slim Laser Scanner's minimal overall height of 50 mm.
4-in-1 Ultra-Slim Laser Scanner
Slim High-Voltage Electrical Component Technology
In its pursuit to create a compact and slim laser printer/MFP, Canon developed a slender high-voltage power board that is recessed into the side of the printer. Although laser printers/MFPs require high voltage and tend to have large power boards, a slimmer design was achieved by replacing the traditional electromagnetic transformer*2 with a piezoelectric*3 transformer to reduce height by about 50% to 8.0 mm. Canon also adopted a new integrated circuit design, reducing the size of the transformer frequency control circuit by approximately one third.
High-Voltage Power Board with Ultra-Slim High-Voltage Electrical Component Technology
- *2 Electromagnetic transformer
A transformer that uses electromagnetic induction to change voltage. Previous electromagnetic transformers used electromagnetic coils for induction.
- *3 Piezoelectric transformer
A transformer that exploits the piezoelectric effect of a piezoelectric element (ceramic) to change voltage.
Slim Structural Design Technology
Canon also decreased the size of laser printers/MFPs by arranging toner cartridges horizontally instead of vertically and developing a draw-type operation. The design of the printer body features a new "fanless" design, which exploits natural convection to eliminate the need for a heat-dissipating fan, and a rigid, lightweight construction.