PT-EW640 is a LCD projector with 5800 lumens (lamp power: auto/normal, dynamic mode, standard lens) brightness. 10W built-in speaker. When vertical keystone correction is used, the image is corrected in the direction that reduces its projected size. Optical axis shift function allows to shift the position of a projected image. The signals that can be input to this projector are shown in the table below. Horizontal scanning frequencies of 15kHz to 100kHz, vertical scanning frequencies of 24Hz to 120Hz, and a dot clock of 162MHz maximum can be input. The serial connector complies with RS-232C. To control the projector from a personal computer, commands must be input through communication software, based on the format and satisfying the communication conditions. If the projector is to be operated continuously 12 hours or more, lamp replacement cycle duration becomes shorter. The lamp replacement cycle duration becomes shorter if the projector is operated repeatedly for short periods.