METHOD AND APPARATUS FOR MONITORING ELECTRO-MAGNETIC RADIATION POWER IN SOLID FREEFORM FABRICATION SYSTEMS

• US 20100173096A1
• Filed: 01/06/2009
• Published: 07/08/2010
• Est. Priority Date: 01/06/2009
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Kritchman, Eliahu M., Libinson, Alexander, Levi, Moshe, Menchik, Guy
• Granted Patent: US 9,242,411 B2
• Time in Patent Office: Days
• US Class Current: 427/553
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes

Abstract

Embodiments of the present invention are directed to a system and method for controlling fabrication of three-dimensional objects, layer by layer, the system comprising a printing assembly, including an irradiation unit and a printing head, the printing assembly is movable between a printing area and a service area. A light sensor positioned at the service area to measure output radiation power of the irradiation unit at a printing plane and a controller to receive information from the sensor and to automatically adjust electrical power supplied to the irradiation unit based on the information.

Claims

1. A dispensing system for forming three-dimensional objects, layer by layer, on a fabrication platform, the system comprising:

a printing assembly movable between a printing area and a service area, wherein the printing assembly includes an irradiation unit and a printing head;

a light sensor positioned at the service area to measure output radiation power of the irradiation unit at a printing plane; and

a controller to receive information from the sensor and to automatically adjust electrical power supplied to the irradiation unit based on the information.

2. The system of claim 1, wherein the printing plane includes the position of a top surface onto which each layer is deposited in the Z direction.

3. The system of claim 1, wherein the irradiation unit is to cure, during formation of a three-dimensional object, a building material having a first curing efficiency within a first range of wavelengths which is higher than a second curing efficiency within a second range of wavelengths.

4. The system of claim 3, wherein the light sensor is substantially responsive to radiation at the first range of wavelengths and non responsive to radiation at the second range of wavelengths.

5. The system of claim 3, wherein the wavelengths of the second range comprising wavelengths which are longer or shorter than the wavelengths of the first range.

6. The system of claim 1, wherein the irradiation unit comprises:

a housing having a transparent window;

a reflecting surface;

a radiation source; and

a second sensor located in proximity to the radiation source to measure directly output radiation power of the radiation source.

7. The system of claim 6, wherein the controller further receives information from the second sensor and adjusts the electrical power supplied to the irradiation unit based on the information from the light sensor and the second sensor.

8. The system of claim 6, wherein the controller further receives information from the second sensor and informs a system operator the status of the reflecting surface and the window upon comparison between information received from light sensor and the second sensor.

9. The system of claim 1, wherein the light sensor is an ultraviolet (UV) sensor responsive in at least part of the range between 280 nanometers and 320 nanometers.

10. The system of claim 1, wherein the light sensor is an ultraviolet (UV) sensor responsive in at least part of the range between 280 nanometers and 400 nanometers.

11. A method for forming three-dimensional objects, layer by layer, on a fabrication platform, the method comprising:

moving a printing assembly between a printing area and a service area, wherein the printing assembly includes an irradiation unit and a printing head;

measuring output radiation power of the irradiation unit at a printing plane by a light sensor positioned at the service area;

receiving information from the sensor; and

automatically adjusting electrical power supplied to the irradiation unit based on the information.

12. The method of claim 11, wherein the printing plane includes the position of a top surface onto which each layer is deposited in the Z direction.

13. The method of claim 11, further comprising:

during formation of a three-dimensional object, curing by the irradiation unit a building material having a first curing efficiency within a first range of wavelengths which is higher than a second curing efficiency within a second range of wavelengths.

14. The method of claim 13, wherein the light sensor is substantially responsive to radiation at the first range of wavelengths and non responsive to radiation at the second range of wavelengths.

15. The method of claim 13, wherein the wavelengths of the second range comprising wavelengths which are longer or shorter than the wavelengths of the first range.

16. The method of claim 11, further comprising:

directly measuring output radiation power of the radiation source by a second sensor located in proximity to the radiation source.

17. The method of claim 16, further comprising:

receiving information from the second sensor and adjusting the electrical power supplied to the irradiation unit based on the information from the light sensor and the second sensor.

18. The method of claim 16, further comprising:

receiving information from the second sensor;

comparing between information received from light sensor and information received from the second sensor; and

informing a system operator the status of the reflecting surface and the window upon comparison between information received from light sensor and the second sensor.

19. The method of claim 11, wherein the light sensor is an ultraviolet (UV) sensor responsive in at least part of the range between 280 nanometers and 320 nanometers.

20. The method of claim 11, wherein the light sensor is an ultraviolet (UV) sensor responsive in at least part of the range between 280 nanometers and 400 nanometers.