Method and system for measuring a pressure distribution between a surface of an object and a pressure-sensitive surface during formation of the object
Described are methods and apparatus for the inspection of cured layers of an object during the fabrication of the object using a 3D printing system. A just-printed layer may be inspected by pressing the layer against a pressure-sensitive surface in order to collect information about the layer. For example, a tank may contain a photo-curing liquid polymer, and at its bottom are pressure sensitive elements (e.g., in a backing member or mask). An extraction plate to which the object is affixed may be adjusted so as to position a surface of the object adjacent to the pressure sensitive elements, which report a pressure distribution (e.g., by virtue of a force exerted by a localized region of the object on a localized region of the pressure sensitive elements).
1. An apparatus, comprising:
a tank configured to contain a photo-curing liquid polymer, the tank including a tank opening;
a mask disposed within the tank opening, the mask including pressure sensitive elements;
a height adjustor configured to control a position of an object; and
a controller configured to:
control the height adjustor so as to position a bottom surface of the object to be adjacent to a top surface of the mask facing into the tank;
control the mask to filter light from a light source to form an image on an image plane adjacent to the bottom surface of the object; and
receive, from the mask, a pressure distribution of pressure measurements, each of the pressure measurements indicating a localized pressure generated by a compressive force exerted from a localized region of the object on a localized region of the mask.
2. The apparatus of claim 1 , wherein the pressure distribution comprises a two-dimensional array of pressure measurements.
3. The apparatus of claim 1 , further comprising a seal disposed between the tank opening and the mask, the seal preventing the photo-curing liquid polymer from leaking out of the tank through the tank opening.
4. The apparatus of claim 1 , further comprising:
the light source configured to emit light, wherein the light emitted by the light source is filtered by the mask prior to entering into the tank.
5. A method, comprising:
controlling a light source and a mask so as to filter light from the light source using the mask and form a layer of photo-cured liquid polymer on an object, the object located within a tank containing a photo-curing liquid polymer, the tank including a tank opening, the tank opening surrounding the mask, and the mask including pressure sensitive elements;
controlling a height adjustor so as to position a bottom surface of the object to be adjacent to a top surface of the mask facing into the tank in preparation for measuring a pressure distribution of pressure measurements, each of the pressure measurements indicating a localized pressure generated by a compressive force exerted from a localized region of the object on a localized region of the mask;
receiving the pressure distribution from the mask; and
controlling the height adjustor so as to position the bottom surface of the object to be away from the top surface of the mask in preparation for a subsequent layer of photo-cured liquid polymer to be formed on the object.
6. The method of claim 5 , wherein the layer of photo-cured liquid polymer is formed by curing a portion of the photo-curing liquid polymer using light emitted by the light source, the light source disposed adjacent to the mask.
7. The method of claim 5 , wherein the pressure distribution comprises a two-dimensional array of pressure measurements.