Patent ID: 7474324

Claim:
A printing apparatus using an order-separation type optical module, comprising: an illumination lens system for converting light, which is output from a light source, into linear light and outputting linear, parallel light; a diffraction type optical modulator for performing desired modulation on the linear, parallel light emitted from the illumination lens system and forming diffracted light having a plurality of diffraction order; a filter system for separating the diffracted light, which has a plurality of diffraction orders and is formed by the diffraction type optical modulator, according to order, and selectively allowing passage of the separated diffracted light therethrough; and a projection system having a drum surface divided into one or more photosensitive areas, so as to allocate the separated diffracted light to respective divided photosensitive areas, whereby the separated diffracted light separated by the filter system according to order is incident on the projection system and, thereby reproducing images from the plurality of diffraction orders incident on the projection system.