Heater for Thermoplastic Filament and Workpiece
A pair of physically-integrated two-stage heaters are disclosed for precisely heating a thermoplastic filament and a thermoplastic workpiece in preparation for depositing the filament onto the workpiece. The design in physically compact and capable of heating the filament and workpiece to within a very narrow temperature range. This is accomplished with four independently-generated light beams, of different frequencies, that are spatially combined and transmitted, via optical fiber or free-space optics, to the location where they are needed and where they are unpacked (i.e., spatially separated) and shone onto their respective targets.
1 . An apparatus comprising:
a length of a filament that is heated by a first light beam at a first time t 1 , wherein the filament comprises a fiber-reinforced thermoplastic material, and wherein the first light beam is characterized by a first wavelength λ 1 ;
an area on a workpiece that is heated by a second light beam at a second time t 2 , wherein the second light beam is characterized by a second wavelength λ 2 , and wherein λ 1 ≠λ 2 ;
a tamping tool for tamping the length of the filament onto the area of the workpiece at a tamping time t T , wherein t T is after t 1 and t T is after t 2 .
2 . The apparatus of claim 1 :
wherein the first light beam is characterized by a first power P 1 (t 1 ) at the first time t 1 ;
wherein the second light beam is characterized by a second power P 2 (t 2 ) at the second time t 2 ; and
wherein P 1 (t 1 )≠P 2 (t 2 ).
3 . The apparatus of claim 1 wherein the length of the filament is heated by a third light beam at a third time t 3 , wherein the third light beam is characterized by a third wavelength λ 3 , wherein t T is after t 3 ; and further comprising:
a first optical beam splitter for receiving a spatial combination of the first light beam and the second light beam and for spatially separating the first light beam and the second light beam; and
a second optical beam splitter for receiving a spatial combination of the first light beam and the third light beam and for spatially separating the first light beam and the third light beam.
4 . The apparatus of claim 3 :
wherein the first light beam is characterized by a first power P 1 (t 1 ) at the first time t 1 ;
wherein the second light beam is characterized by a second power P 2 (t 2 ) at the second time t 2 ;
wherein the third light beam is characterized by a third power P 3 (t 3 ) at the third time t 3 ; and
wherein P 1 (t 1 )≠P 2 (t 2 )≠P 3 (t 3 ).
5 . The apparatus of claim 3 wherein the area of the workpiece is heated by a fourth light beam at a fourth time t 4 , wherein the fourth light beam is characterized by a fourth wavelength λ 4 , wherein t T is after t 4 ; and further comprising:
a third optical beam splitter for receiving a spatial combination of the second light beam and the fourth light beam and for spatially separating the second light beam and the fourth light beam.
6 . The apparatus of claim 1 wherein the area of the workpiece is heated by a third light beam at a third time t 3 , wherein the third light beam is characterized by a third wavelength λ 3 , wherein t T is after t 3 ; and further comprising:
a second optical beam splitter for receiving a spatial combination of the second light beam and the third light beam and for spatially separating the second light beam and the third light beam.
7 . The apparatus of claim 6 :
wherein the first light beam is characterized by a first power P 1 (t 1 ) at the first time t 1 ;
wherein the second light beam is characterized by a second power P 2 (t 2 ) at the second time t 2 ;
wherein the third light beam is characterized by a third power P 3 (t 3 ) at the third time t 3 ; and
wherein P 1 (t 1 )≠P 2 (t 2 )≠P 3 (t 3 ).
8 . The apparatus of claim 1 further comprising:
a first laser for generating the first light beam;
a second laser for generating the second light beam; and
an optical beam combiner for receiving a spatially-separate first light beam and second light beam and for spatially combining the first light beam and the second light beam.
9 . An apparatus comprising:
a length of a filament that is heated by a first light beam at a first time t 1 and that is heated by a second light beam at a second time t 2 , wherein the filament comprises a fiber-reinforced thermoplastic material, wherein the first light beam is characterized by a first wavelength λ 1 , wherein the second light beam is characterized by a second wavelength λ 2 , wherein t 1 ≠t 2 , and wherein λ 1 ≠λ 2 ;
an area on a workpiece that is heated by a third light beam at a third time t 3 , wherein the third light beam is characterized by a third wavelength λ 3 , and wherein λ 1 ≠λ 2 ≠λ 3 ;
a tamping tool for tamping the length of the filament onto the area of the workpiece at a tamping time t T , wherein t T is after t 1 , t T is after t 2 , and t T is after t 3 .
10 . The apparatus of claim 9 further comprising:
an optical beam splitter for receiving a spatial combination of the first light beam and the second light beam and for spatially separating the first light beam and the second light beam.
11 . The apparatus of claim 9 further comprising:
an optical beam splitter for receiving a spatial combination of the first light beam and the third light beam and for spatially separating the first light beam and the third light beam.
12 . The apparatus of claim 9 :
wherein the first light beam is characterized by a first power P 1 (t 1 ) at the first time t 1 ;
wherein the second light beam is characterized by a second power P 2 (t 2 ) at the second time t 2 ; and
wherein P 1 (t 1 )≠P 2 (t 2 ).
13 . The apparatus of claim 9 further comprising:
a first laser for generating the first light beam;
a second laser for generating the second light beam; and
an optical beam combiner for receiving a spatially-separate first light beam and second light beam and for spatially combining the first light beam and the second light beam.
14 . An apparatus comprising:
a length of a filament that is heated by a first light beam at a first time t 1 , wherein the filament comprises a fiber-reinforced thermoplastic material, and wherein the first light beam is characterized by a first wavelength λ 1 ;
an area on a workpiece that is heated by a second light beam at a second time t 2 and that is heated by a third light beam at a third time t 3 , wherein the second light beam is characterized by a second wavelength λ 2 , wherein the third light beam is characterized by a third wavelength λ 3 , wherein t 2 ≠t 3 , and wherein λ 1 ≠λ 2 ≠λ 3 ;
a tamping tool for tamping the length of the filament onto the area of the workpiece at a tamping time t T , wherein t T is after t 1 , t T is after t 2 , and t T is after t 3 .
15 . The apparatus of claim 14 further comprising:
an optical beam splitter for receiving a spatial combination of the first light beam and the second light beam and for spatially separating the first light beam and the second light beam.
16 . The apparatus of claim 14 further comprising:
an optical beam splitter for receiving a spatial combination of the first light beam and the third light beam and for spatially separating the first light beam and the third light beam.
17 . The apparatus of claim 14 :
wherein the first light beam is characterized by a first power P 1 (t 1 ) at the first time t 1 ;
wherein the second light beam is characterized by a second power P 2 (t 2 ) at the second time t 2 ;
wherein the third light beam is characterized by a third power P 3 (t 3 ) at the third time t 3 ; and
wherein P 1 (t 1 )≠P 2 (t 2 )≠P 3 (t 3 ).
18 . The apparatus of claim 14 further comprising:
a first laser for generating the first light beam;
a second laser for generating the second light beam; and
an optical beam combiner for receiving a spatially-separate first light beam and second light beam and for spatially combining the first light beam and the second light beam.