Patent ID: 9327449
Filing Date: 2016-05-03
CPC Classification: B29C,B29L,B33Y

Claim Text:
1. A three-dimensional printing apparatus, comprising: a tank, filled with a liquid forming material and a separating liquid, wherein a specific density of the separating liquid is larger than a specific density of the liquid forming material, and the separating liquid and the liquid forming material are substantially immiscible with each other, so that the separating liquid sinks between the bottom of the tank and the liquid forming material; a moving platform, movably disposed above the tank; a light source, disposed below the tank so as to irradiate the liquid forming material; a detecting unit, comprising an optical element disposed at a side of the tank, and adapted to move along an axial direction and to emit a ray of light towards the separating liquid and the liquid forming material, the axial direction is perpendicular to the junction between the separating liquid and the liquid forming material, and the light is parallel to the junction, so as to detect a junction between the separating liquid and the liquid forming material through the reflection of the light; and a control unit, coupled to the light source, the detecting unit and the moving platform, wherein the control unit controls an initial depth at which the moving platform immerses into the liquid forming material, according to the junction detected by the detecting unit, the control unit controls the moving platform to move from the initial depth in the liquid forming material layer by layer towards a direction away from the light source, and controls the light source to irradiate the liquid forming material, so as to cure the irradiated liquid forming material layer by layer, thereby forming a three-dimensional object on the moving platform.