Three dimensional printing system with vertically translating build plane

1 . A three-dimensional (3D) printing system configured to print a 3D article comprising:

a build vessel configured to contain fluid above a transparent plate, the build vessel including first and second fluid ports, the second fluid port is above the first fluid port;

a build platen having a lower surface in facing relation with the transparent plate;

a transparent fluid contained within the build vessel and vertically bounded between the transparent plate and a build plane, the transparent fluid having a first specific gravity;

a photocurable fluid contained within the build vessel and vertically bounded between the build plane and an upper fluid surface which is above the lower surface of the build platen, the photocurable fluid having a second specific gravity that is less than the first specific gravity;

a first fluid source coupled to the first fluid port and configured to control a vertical position of the build plane by extracting or injecting the transparent fluid through the first fluid port;

a light engine configured to transmit pixelated radiation to the build plane; and

a controller configured to:

operate the first fluid source to lower the build plane with an average velocity V by extraction of the transparent fluid from the build vessel;

concurrent with operating the first fluid source, operate the light engine to lower a focal plane of the light engine at the average velocity V; and

concurrent with operating the first fluid source, operate the light engine to selectively irradiate the build plane and to accrete the 3D article in a downward direction by the average velocity V.

2 . The 3D printing system of claim 1 further comprising a second fluid source coupled to the second fluid port, the controller is configured to operate the second fluid source concurrently with operating the first fluid source the photocurable fluid above the build plane.

3 . The 3D printing system of claim 1 , wherein the first fluid source includes a first fluid tank containing the transparent fluid and a pump that operates between the first fluid tank and the first fluid port.

4 . The 3D printing system of claim 1 , wherein the controller operates the first fluid source to lower the build plane in a series of vertical steps individually having an average vertical step height of h and with the steps spaced temporally with an average time duration of T, the velocity V equals h/T.

5 . The 3D printing system of claim 1 , wherein the controller operates the first fluid source to lower the build plane continuously with the velocity V.

6 . The 3D printing system of claim 1 , wherein the light engine includes a projection unit coupled to a vertical movement mechanism, the controller lowers the focal plane by operating the vertical movement mechanism to lower the projection unit.

7 . A method of manufacturing a three-dimensional (3D) article comprising:

providing a build vessel configured to contain fluid above a transparent plate, the build vessel including first and second fluid ports, the second fluid port is above the first fluid port;

providing a build platen having a lower surface in facing relation with the transparent plate;

providing a transparent fluid contained within the build vessel and vertically bounded between the transparent plate and a build plane, the transparent fluid having a first specific gravity;

providing a photocurable fluid contained within the build vessel and vertically bounded between the build plane and an upper fluid surface which is above the lower surface of the build platen, the photocurable fluid having a second specific gravity that is lesser than the first specific gravity;

providing a first fluid source coupled to the first fluid port and configured to control a vertical position of the build plane by extracting or injecting the transparent fluid through the first fluid port;

providing a light engine configured to transmit pixelated radiation to the build plane;

operating the first fluid source to lower the build plane with an average velocity V by extraction of the transparent fluid from the build vessel;

concurrent with operating the first fluid source, operating the light engine to lower a focal plane of the light engine at the average velocity V; and

concurrent with operating the first fluid source, operating the light engine to selectively irradiate the build plane and to accrete the 3D article in a downward direction by the average velocity V.

8 . The method of claim 7 further including:

providing a second fluid source coupled to the second fluid port; and

operating the second fluid source concurrently with operating the first fluid source to inject the photocurable fluid above the build plane.

9 . The method of claim 7 , wherein the first fluid source includes a first fluid tank containing the transparent fluid and a pump that operates between the first fluid tank and the first fluid port, operating the first fluid source includes operating the pump.

10 . The method of claim 7 , wherein the build plane is lowered in a series of vertical steps individually having an average vertical step height of h and with the steps spaced temporally with an average time duration of T, the velocity V equals h/T.

11 . The method of claim 7 , wherein the build plane is lowered continuously with the velocity V.

12 . The method of claim 7 , wherein the light engine includes a projection unit coupled to a vertical movement mechanism, lowering the focal plane includes operating the vertical movement mechanism to lower the projection unit.