Abstract

Conventional two dimensional scanning methods operate by a two axis variable mirror system to deflect one laser beam over the whole 0image field Hence there occur two different deflection frequencies, one of which is the critical horizontal deflection frequency in the kHz regime and the other one is the uncritical vertical frequency of about 100Hz. The horizontal deflection frequency is difficult to achieve with mecanical means because precisely manufactured polygon mirrors must be employed to achieve a pointing stability good enough for printing and display applications A number of devices have been developed recently to find alternatives to the conventional method The axial line scanner intends to resolve this problem by utilizing a different scanning method: always one complete line is imaged in one scanning step and to obtain a complete two dimensional image it is thus just necessary to shift the lines vertically The same concept could be applied in printing equipment where a rotating shaft is placed in front of the axial line scanner To realize this concept it is neccessary to generate simultaneously a discrete number of points with equal beam characteristics and a fixed pitch Furthermore these applications require an independant modulation of each channel's output power in order to generate intensity dependant effects

© 2000 IEEE