Color printing with an LBP requires toner in the four CMYK colors. This, in turn, requires that each color have its own toner cartridge, photosensitive drum and laser scanner, resulting in color LBPs that are large and, consequently, inconvenient for many users. Canon, by reexamining every aspect of the structure of LBPs until now, overcame the problem of size with the introduction of a four-color vertical in-line engine, a 4-in-1 laser scanner, and an ultra-short path. These efforts resulted in the birth of an unprecedented compact A3 color LBP.

The LBP5900, with photosensitive drums each measuring 30 mm in diameter aligned at a pitch of 70 mm, was designed to realize the smallest possible footprint, which is comparable to that for monochrome models. With conventional models, however, such a small drum pitch would not enable fast enough toner replenishment to support high-speed printing. To solve this problem, Canon developed a four-color vertical in-line engine incorporating four photosensitive drums arranged diagonally so that they overlap vertically, thereby achieving a balance of compact dimensions and high-speed printing. The diagonal layout of the drum cartridges ensures easier front-panel operations and improved operability.

To realize a space-saving printer design, Canon thoroughly reviewed every aspect of the paper path, which led to the creation of an ultrashort path. Providing a short paper path doesn't just reduce dimensions, it makes possible a variety of benefits, including faster printing speeds and fewer components. This streamlined paper transport route also allowed the company to easily incorporate an automatic duplex (doublesided) printing transport route as a standard feature.

Achieving high image quality and high-speed printing with the shortest paper path requires advanced control technologies. To this end, Canon developed advanced paper transport simulation software to enable the thorough verification and optimization of the distances and relative positions between the paper rollers, intermediate transfer belt, and fixing unit. As a result, Canon was able to achieve first-print speeds of just 9 seconds for color and 7.5 seconds for monochrome.

Paper Path of the LBP5900

In conventional color laser beam printers, each photosensitive drum for each of the four toner colors required its own laser scanner. Canon's LBP5900 successfully integrates these into a single laser scanner unit, directing four color laser beams to a polygon mirror at oblique angles (oblique incidence technology) to split the light path into four directions and guide each toward its respective photosensitive drum. The result is the 4-in-1 laser scanner, which realizes revolutionary space savings, and a significant reduction in parts for lower costs.

4-in-1 Laser Scanner