Methods and systems for generating pulses of laser radiation at higher repetition rates than those of available excimer lasers are disclosed that use multiple electronic triggers for multiple laser units and arrange the timings of the different triggers with successive delays, each delay being a fraction of the interval between two successive pulses of a single laser unit. The first registration method in which copy modes such as the number of copies, magnification, copy darkness and need for collation are set using an operation panel in the same way as in conventional copying machines to register a job. The control member includes a handle extension movable between an actuating operative position, in which the handle extension is deployed, and a non-operative position, in which the extension is laid down andor withdrawn to reduce overall dimensions. The latching beam includes a driving portion and an outwardly extending latching portion adjacent to the mating portion.