Lighting for additive manufacturing

Abstract

In one example, a lighting device for an additive manufacturing machine includes first light sources each to emit monochromatic light within a first band of wavelengths that includes a peak light absorption of a liquid coalescing agent and second light sources each to emit monochromatic light within a second band of wavelengths different from the first band of wavelengths. Each of the first light sources or each of multiple groups of the first light sources is individually addressable to emit monochromatic light independent of any other of the first light sources or of any other group of the first light sources and each of the second light sources or each of multiple groups of the second light sources is individually addressable to emit monochromatic light independent of any other of the second light sources or of any other group of the second light sources.

What is claimed is: 
     
         1 . A lighting device for an additive manufacturing machine, comprising:
 first light sources each to emit monochromatic light within a first band of wavelengths that includes a peak light absorption of a liquid coalescing agent to be dispensed on to a build material;   second light sources each to emit monochromatic light within a second band of wavelengths different from the first band of wavelengths;   each of the first light sources or each of multiple groups of the first light sources individually addressable to emit monochromatic light independent of any other of the first light sources or of any other group of the first light sources; and   each of the second light sources or each of multiple groups of the second light sources individually addressable to emit monochromatic light independent of any other of the second light sources or of any other group of the second light sources.   
     
     
         2 . The device of  claim 1 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a colorless coalescing agent that absorbs at least 60% of light having a wavelength in the range of 800 nm to 1350 nm; and   the first band of wavelengths is 800 nm to 1350 nm.   
     
     
         3 . The device of  claim 1 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a yellow coalescing agent that absorbs at least 60% of light having a wavelength in the range of 380 nm to 500 nm; and   the first band of wavelengths is 380 nm to 500 nm.   
     
     
         4 . The device of  claim 1 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a magenta coalescing agent that absorbs at least 60% of light having a wavelength in the range of 420 nm to 600 nm; and   the first band of wavelengths is 420 nm to 600 nm.   
     
     
         5 . The device of  claim 1 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a cyan coalescing agent that absorbs at least 60% of light have a wavelength in the range of 520 nm to 700 nm; and   the first band of wavelengths is 520 nm to 700 nm.   
     
     
         6 . The device of  claim 1 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a black coalescing agent that absorbs at least 60% of light having a wavelength in the range of 380 nm to 700 nm; and   the first band of wavelengths is 380 nm to 700 nm.   
     
     
         7 . The device of  claim 1 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes one or more of a colorless coalescing agent that absorbs at least 60% of light having a wavelength in the range of 800 nm to 1350 nm, a yellow coalescing agent that absorbs at least 60% of light having a wavelength in the range of 380 nm to 500 nm, a magenta coalescing agent that absorbs at least 60% of light having a wavelength in the range of 420 nm to 600 nm, a cyan coalescing agent that absorbs at least 60% of light have a wavelength in the range of 520 nm to 700 nm, and a black coalescing agent that absorbs at least 60% of light having a wavelength in the range of 380 nm to 700 nm;   the first band of wavelengths is a first one or more of 800 nm to 1350 nm, 380 nm to 500 nm, 420 nm to 600 nm, 520 nm to 700 nm, and 380 nm to 700 nm; and   the second band of wavelengths is a second, different one or more of 800 nm to 1350 nm, 380 nm to 500 nm, 420 nm to 600 nm, 520 nm to 700 nm, and 380 nm to 700 nm.   
     
     
         8 . The device of  claim 1 , wherein each of the first and second light sources is a single light source to emit monochromatic light with a spectral intensity of at least 1×10 12  Wm −3 sr −1 . 
     
     
         9 . A system, comprising:
 an array of light sources each to emit monochromatic light within a band of wavelengths that includes a peak light absorption of a liquid coalescing agent to be dispensed on to a build material, each of the light sources or each of multiple groups of the light sources individually addressable in the array to emit light independent of any other light source in the array or of any other group of light sources in the array; and   a processor readable medium having lighting instructions thereon that when executed cause light sources in the array to illuminate patterned build material with monochromatic light within a band of wavelengths that includes a peak light absorption of the liquid coalescing agent.   
     
     
         10 . The system of  claim 9 , wherein each of the light sources is a single light source to emit monochromatic light with a spectral intensity of at least 1×10 12  Wm −3 sr −1 . 
     
     
         11 . The system of  claim 9 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a colorless coalescing agent that absorbs at least 60% of light having a wavelength in the range of 800 nm to 1350 nm; and   the band of wavelengths is 800 nm to 1350 nm.   
     
     
         12 . The system of  claim 9 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a yellow coalescing agent that absorbs at least 60% of light having a wavelength in the range of 380 nm to 500 nm; and   the band of wavelengths is 380 nm to 500 nm.   
     
     
         13 . The system of  claim 9 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a magenta coalescing agent that absorbs at least 60% of light having a wavelength in the range of 420 nm to 600 nm; and   the band of wavelengths is 420 nm to 600 nm.   
     
     
         14 . The system of  claim 9 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a cyan coalescing agent that absorbs at least 60% of light have a wavelength in the range of 520 nm to 700 nm; and   the band of wavelengths is 520 nm to 700 nm.   
     
     
         15 . The system of  claim 9 , wherein:
 the liquid coalescing agent to be dispensed on to the build material includes a black coalescing agent that absorbs at least 60% of light having a wavelength in the range of 380 nm to 700 nm; and   the band of wavelengths is 380 nm to 700 nm.   
     
     
         16 . The system of  claim 9 , wherein the processor readable medium is implemented in a CAD computer program product. 
     
     
         17 . The system of  claim 9 , wherein the processor readable medium is implemented in a controller for an additive manufacturing machine. 
     
     
         18 . An additive manufacturing machine, comprising:
 a first device to layer a powdered build material;   a second device to dispense a liquid coalescing agent;   a third device to dispense a liquid coalescing modifier agent;   light sources to illuminate build material, each of the light sources or each of multiple groups of the light sources individually addressable to emit monochromatic light independent of any other of the light sources or of any other group of the light sources; and   a controller to execute instructions to:   cause the first device to layer the powdered build material;   cause the second device to dispense the liquid coalescing agent on to a layer of the powdered build material in a pattern of a slice;   cause the third device to dispense the liquid coalescence modifier agent on to the layer of powdered build material bordering the patterned build material, on to the patterned build material, or on to the layer of powdered build material bordering the patterned build material and on to the patterned build material; and   cause some or all of the light sources to illuminate patterned build material with monochromatic light within a band of wavelengths that includes the peak light absorption of the liquid coalescing agent.   
     
     
         19 . The machine of  claim 18 , wherein the monochromatic light sources include:
 first light sources each to emit monochromatic light within a first band of wavelengths that includes the peak light absorption of the liquid coalescing agent; and   second light sources each to emit monochromatic light within a second band of wavelengths different from the first band of wavelengths;   each of the first light sources or each of multiple groups of the first light sources individually addressable to emit monochromatic light independent of any other of the first light sources or of any other group of the first light sources; and   each of the second light sources or each of multiple groups of the second light sources individually addressable to emit monochromatic light independent of any other of the second light sources or of any other group of the second light sources.   
     
     
         20 . The machine of  claim 19 , wherein each of the first light sources is to emit monochromatic light with a spectral intensity of at least 1×10 12  Wm −3 sr −1 .