We have developed 1200 dot-per-inch (dpi) light-emitting-diode (LED) array chips for very-high-speed electrophotographic printheads. The emitted light efficiencies of the 1200 dpi new LED array chips developed in this study were one order of magnitude higher than those of the 1200 dpi conventional GaAsP LED array chips. Temperature increases (ΔT) of the printhead using the 1200 dpi new LED array chips operated at 12 pages per minute (ppm) were very small, while those of the printhead using the 1200 dpi GaAsP LED array chips were 50°C operated at the same printing speed. ΔT of the new LED printhead at 120 ppm was estimated to be 30°C at most. Registering error caused by thermal expansion of the printhead substrate was also estimated, and is small enough for 1200 dpi printing due to small temperature increases when used with the new LED array chips. Performance tests show that the new LED array chips can be used for printhead applications requiring high resolution, high printing speed, and low power consumption. The new LED array chips can be applied for color electrophotographic printheads.
H. Hamano, M. Ogihara, M. Taninaka, H. Kikuchi, Y. Nakamura, "1200 DPI LED Printhead for Very High Speed Printing" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP14), 1998, pp 405 - 408, https://doi.org/10.2352/ISSN.2169-4451.1998.14.1.art00018_2