US Patent 9213312 Holographic 3D printing apparatus and method of driving the same

A holographic three-dimensional (3D) printing apparatus and a method of driving the same are provided. The holographic 3D printing apparatus includes a light source configured to emit a beam, a beam splitting and expanding unit configured to split the emitted beam into a reference beam and a signal beam and expand the signal beam, an illumination unit configured to extract the expanded signal beam and collimate the extracted signal beam, a spatial light modulator (SLM) configured to modulate the collimated signal beam, an objective lens unit configured to emit the modulated signal beam to a holographic recording medium, and a reference beam forming unit configured to emit the reference beam to the holographic recording medium.