DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This action is in response to the applicant’s communication filed on 3/11/2024
Claims 1-20 are pending
Claim Objections
Claim 1 objected to because of the following informalities: “L-BPF” in line 2 is assumed to be misspelled and meant to be “L-PBF”. For the purposes of examination, “L-BPF” in claim 1 will be interpreted as “L-PBF”. If “L-BPF” is not actually misspelled, then an antecedent basis issue exists. Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 13 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 13 contains the trademark/trade name Arduino. Where a trademark or trade name is used in a claim as a limitation to identify or describe a particular material or product, the claim does not comply with the requirements of 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph. See Ex parte Simpson, 218 USPQ 1020 (Bd. App. 1982). The claim scope is uncertain since the trademark or trade name cannot be used properly to identify any particular material or product. A trademark or trade name is used to identify a source of goods, and not the goods themselves. Thus, a trademark or trade name does not identify or describe the goods associated with the trademark or trade name. In the present case, the trademark/trade name is used to identify/describe a controller and, accordingly, the identification/description is indefinite.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1, 3, 11-12, 14, 16, and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kruth et al. USPGPUB 2009/0206065 A1 (hereinafter Kruth) in view of Cheverton et al. USPGPUB 2016/0114431 A1 (hereinafter Cheverton).
Regarding claim 1, Kruth teaches a feedback control system (Fig. 3, Par. [0067], “schematic outline of a feedback control system”), comprising:
a laser powder bed fusion (L-PBF) platform comprising a laser, the L-PBF platform configured to print a target object with the laser (Par. [0087], “"Selective Laser Powder Processing" refers to a layer-wise manufacturing technique that allows generating complex 3D parts by selectively consolidating successive layers of powder material on top of each other using the thermal energy of a laser beam that is focused on a powder bed.” – 3D parts is interpreted as a target object);
a sensing system configured to measure an operative thermal emission index (TEI) emitted during print of the target object by the L-PBF platform (Par. [0094], “A coaxial optical system is used to capture the radiation that is emitted by the heated material in the melt zone around the laser spot. The spectral range of the emitted electromagnetic radiation depends on the temperature of the material in the melt zone”; Par. [0051], “detecting electromagnetic radiation emitted by or reflected from a moving observation zone on said powder surface, said moving observation zone comprising at least the incidence point of the laser beam on the powder surface”; Par. [0102], “A signal indicative for the area of the melt zone can also be recorded using an integrating detector like a photo diode with a large active area and an appropriate lens that focuses radiation emitted from the whole melt zone area around the laser spot on the active area of the integrating detector. The detector will thus measure variations in the melt zone temperature (according to Planck's law of spectral radiation) as well as variations in the melt zone area”- emitted radiation is interpreted as an operative thermal emission index); and
a controller communicatively coupled to the sensing system (Par. [0023] – [0024], “a control unit allowing to automatically adjust the process parameters using the signal provided by said detector. … The signal obtained by the detector is used by a control apparatus to control the processing parameters of the laser beam or the laser scanning device” – Control unit/control apparatus corresponds to the claimed controller because it receives the signal provided by the detector and uses the detector signal to control the processing parameters of the laser beam or laser scanning device, thereby teaching that the controller is communicatively coupled to the sensing system.) and configured to:
determine an error based on a comparison between a control setpoint and the operative TEI (Par. [0104], “The signals from either a spatially resolved sensor like a CMOS or CCD camera or from an integrating sensor like a planar photo-diode, are used to identity one or more measured process variables reflecting the area of the melt zone or some other geometric quantity of the melt zone. Such process variable is then compared with a desired value that can be experimentally determined, and the difference between the process variable and the desired value is used to adjust one or more adjustable process parameters.” – measured process variables corresponds to the operative TEI because it is derived from the detector signal measuring emitted radiation from the melt zone, desired value corresponds to the claimed control setpoint, and the difference between the measured process variable and the desired value corresponds to the claimed error.);
Kruth does not explicitly teach generate a control signal based on the error; and
adaptively adjust a power of the laser during the print of the target object based on the control signal to maintain the control setpoint.
However, Cheverton teaches generate a control signal based on the error (Par. [0025], “If the size and/or temperature of the melt pool are outside predetermined limits from the calibration model at a specific operating condition, a computing device generates control signals in response”); and
adaptively adjust a power of the laser during the print of the target object based on the control signal to maintain the control setpoint (Par. [0056], “After determining the size and/or temperature of melt pool area 50, computing device 46 generates control signals 56 that are transmitted to controller 20 to modify 406 build parameters 72 in real-time to achieve a desired physical property of component 48 … For example, without limitation, if computing device 46 determines that the size of melt pool area 50 is too large, or the temperature is too high, computing device 46 may generate control signals 56 that are used by controller 20 to reduce the power output of laser device 14 or increase the scanning speed of laser device 14 to reduce the size and/or temperature of melt pool area 50”).
Kruth and Cheverton are analogous art because they are from the same field of endeavor and contain functional similarities. They both relate to using laser powder bed additive manufacturing with real-time melt pool monitoring and feedback control.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control system for selective laser powder processing, as taught by Kruth, and incorporate control signal architecture, which generates control signals based on a difference value and transmits the control signals to a controller to modify build parameters in real time, as taught by Cheverton.
One of ordinary skill in the art would have been motivated to improve “the quality of the surface finish throughout the printed component as well as the shape accuracy of the part may be improved. In addition, small feature resolution, often lost because of varying thermal conductivity, may also be enhanced.” as suggested by Cheverton (Par. [0005]).
Regarding claim 3, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein the control setpoint corresponds to a target TEI to be maintained for the print of the target object (Par. [0014], “temperature at a certain detection point in the sintering zone is maintained at a constant level by the feedback control loop.”; Par. [0127], “To avoid the large fluctuation of the melt zone geometry and the resulting bad part geometry, feedback control, using the measured photodiode signal (itself correlating to the melt zone area), was used. The set point for the photo-diode output signal was 0.5V” – The photodiode output signal corresponds to an operative TEI because the photodiode receives radiation emitted from the melt zone, and the signal is a thermal emission derived process signal used for feedback control. Accordingly, Kruth’s 0.5V photodiode output setpoint corresponds to a target TEI to be maintained during printing.).
Regarding claim 11, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein:
the controller comprises a proportional-integral-derivative (PID) controller (Par. [0043], “the control apparatus comprises a control algorithm for determining the new process parameters of the laser beam or scanning means. This control algorithm can be for example a Proportional controller (P), Proportional-integrative controller (PI) or Proportional-Integrative-Differential (PID) controller.”); and
the controller is further configured to generate the control signal based on processing the error with a proportional (P) calculation, an integral (I) calculation, and a derivative (D) calculation (Par. [0104], “Such process variable is then compared with a desired value that can be experimentally determined, and the difference between the process variable and the desired value is used to adjust one or more adjustable process parameters … Within each control loop, a certain control algorithm is used to calculate the new value(s) of the adjustable process parameter(s) based on the current and/or previous values of the measured process variable. For example a PID controller can be used, but more advanced control strategies, like adaptive or model based controllers, are also possible and might lead to a better performance.”).
Regarding claim 12, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein the controller comprises a first controller, the first controller comprising the PID controller (Par. [0043], “the control apparatus comprises a control algorithm for determining the new process parameters of the laser beam or scanning means. This control algorithm can be for example a Proportional controller (P), Proportional-integrative controller (PI) or Proportional-Integrative-Differential (PID) controller.” – PID controller corresponds to the first controller).
Kruth does not explicitly teach a second controller, the second controller comprising a data acquisition controller.
However, Cheverton teaches a second controller, the second controller comprising a data acquisition controller (Par. [0042], “DMLM system 10 includes computing device 46 that operates at least partially as a data acquisition device and monitors the operation of DMLM system 10 during fabrication of component 48”; Par. [0044], “computing device 46 that may be used to perform data acquisition and monitoring of any piece of equipment, system, and process, such as, without limitation, acquiring data, and monitoring geometric conditions of component 48 during fabrication by DMLM system 10.” - computing device is interpreted as a data acquisition controller because the computing device operates at least partially as a data acquisition device, acquires and monitors process data during fabrication, compares measured melt-pool information to a calibration model, and generates control signals used to modify build parameters in real time.)
Regarding claim 14, Kruth teaches a method for controlling a system (Fig. 3, Par. [0067], “schematic outline of a feedback control system”), the system comprising a laser powder bed fusion (L-PBF) platform (Par. [0017], “a building platform designed to comprise a powder
bed”) and a sensing system (Par. [0094], “A coaxial optical system is used to capture the radiation that is emitted by the heated material in the melt zone around the laser spot. The spectral range of the emitted electromagnetic radiation depends on the temperature of the material in the melt zone”; Par. [0051], “detecting electromagnetic radiation emitted by or reflected from a moving observation zone on said powder surface, said moving observation zone comprising at least the incidence point of the laser beam on the powder surface”), the method comprising:
determining, by a controller, an error based on a comparison between a control setpoint and an operative thermal emission index (TEI) measured by the sensing system during print of a target object by a laser of the L-PBF platform (Par. [0104], “The signals from either a spatially resolved sensor like a CMOS or CCD camera or from an integrating sensor like a planar photo-diode, are used to identity one or more measured process variables reflecting the area of the melt zone or some other geometric quantity of the melt zone. Such process variable is then compared with a desired value that can be experimentally determined, and the difference between the process variable and the desired value is used to adjust one or more adjustable process parameters.” – the difference between the process variable and the desired value is interpreted as an error);
Kruth does not explicitly teach generating, by the controller, a control signal based on the error; and
adaptively adjusting, by the controller, a power of the laser during the print of the target object based on the control signal to maintain the control setpoint.
However, Cheverton teaches generating, by the controller, a control signal based on the error (Par. [0025], “If the size and/or temperature of the melt pool are outside predetermined limits from the calibration model at a specific operating condition, a computing device generates control signals in response”); and
adaptively adjusting, by the controller, a power of the laser during the print of the target object based on the control signal to maintain the control setpoint (Par. [0056], “After determining the size and/or temperature of melt pool area 50, computing device 46 generates control signals 56 that are transmitted to controller 20 to modify 406 build parameters 72 in real-time to achieve a desired physical property of component 48 … For example, without limitation, if computing device 46 determines that the size of melt pool area 50 is too large, or the temperature is too high, computing device 46 may generate control signals 56 that are used by controller 20 to reduce the power output of laser device 14 or increase the scanning speed of laser device 14 to reduce the size and/or temperature of melt pool area 50”).
Kruth and Cheverton are analogous art because they are from the same field of endeavor and contain functional similarities. They both relate to using laser powder bed additive manufacturing with real-time melt pool monitoring and feedback control.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control system for selective laser powder processing, as taught by Kruth, and incorporate control signal architecture, which generates control signals based on a difference value and transmits the control signals to a controller to modify build parameters in real time, as taught by Cheverton.
One of ordinary skill in the art would have been motivated to improve “the quality of the surface finish throughout the printed component as well as the shape accuracy of the part may be improved. In addition, small feature resolution, often lost because of varying thermal conductivity, may also be enhanced.” as suggested by Cheverton (Par. [0005]).
Regarding claim 16, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein the control setpoint corresponds to a target TEI to be maintained for the print of the target object (Par. [0014], “temperature at a certain detection point in the sintering zone is maintained at a constant level by the feedback control loop.”; Par. [0127], “To avoid the large fluctuation of the melt zone geometry and the resulting bad part geometry, feedback control, using the measured photodiode signal (itself correlating to the melt zone area), was used. The set point for the photo-diode output signal was 0.5V” – The photodiode output signal corresponds to an operative TEI because the photodiode receives radiation emitted from the melt zone, and the signal is a thermal emission derived process signal used for feedback control. Accordingly, Kruth’s 0.5V photodiode output setpoint corresponds to a target TEI to be maintained during printing).
Regarding claim 20, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein:
the controller comprises a proportional-integral-derivative (PID) controller (Par. [0043], “the control apparatus comprises a control algorithm for determining the new process parameters of the laser beam or scanning means. This control algorithm can be for example a Proportional controller (P), Proportional-integrative controller (PI) or Proportional-Integrative-Differential (PID) controller.”), and wherein generating the control signal is further based on processing the error with a proportional (P) calculation, an integral (I) calculation, and a derivative (D) calculation (Par. [0104], “Such process variable is then compared with a desired value that can be experimentally determined, and the difference between the process variable and the desired value is used to adjust one or more adjustable process parameters … Within each control loop, a certain control algorithm is used to calculate the new value(s) of the adjustable process parameter(s) based on the current and/or previous values of the measured process variable. For example a PID controller can be used, but more advanced control strategies, like adaptive or model based controllers, are also possible and might lead to a better performance.”).
Claim(s) 2, 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kruth et al. USPGPUB 2009/0206065 A1 (hereinafter Kruth) in view of Cheverton et al. USPGPUB 2016/0114431 A1 (hereinafter Cheverton), and further in view of Das et al. US 10,639,721 B2 (hereinafter Das).
Regarding claim 2, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth teaches wherein the controller is configured to determine the error based on a comparison of the control setpoint to an operative TEI (Par. [0104], “The signals from either a spatially resolved sensor like a CMOS or CCD camera or from an integrating sensor like a planar photo-diode, are used to identity one or more measured process variables reflecting the area of the melt zone or some other geometric quantity of the melt zone. Such process variable is then compared with a desired value that can be experimentally determined, and the difference between the process variable and the desired value is used to adjust one or more adjustable process parameters.” – measured process variables corresponds to the operative TEI because it is derived from the detector signal measuring emitted radiation from the melt zone, desired value corresponds to the claimed control setpoint, and the difference between the measured process variable and the desired value corresponds to the claimed error.), but
Kruth and Cheverton do not explicitly teach a moving average of the operative TEI.
However, Das teaches a moving average of the operative TEI (Claim 8, “filter the captured thermal image data through a short finite impulse response moving average filter; and
estimate a temperature distribution of the melt pool based on the filtered captured thermal image data”; Col. 48, lines 10-13, “To alleviate any issues with dropped frames and remove excess noise, a short finite impulse response (FIR) moving average filter can be implemented in the control schemes”).
Kruth, Cheverton, and Das are analogous art because they are from the same field of endeavor and contain functional similarities. They all relate to using laser powder bed additive manufacturing with real-time melt pool monitoring and feedback control.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control system for selective laser powder processing, as taught by Kruth and Cheverton, and incorporate using a moving average filter for thermal melt pool feedback data, as taught by Das.
One of ordinary skill in the art would have been motivated to “alleviate any issues with dropped frames and remove excess noise” as suggested by Das (Col. 48, lines 10-13).
Regarding claim 15, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth teaches comparing the control setpoint to an operative TEI (Par. [0104], “The signals from either a spatially resolved sensor like a CMOS or CCD camera or from an integrating sensor like a planar photo-diode, are used to identity one or more measured process variables reflecting the area of the melt zone or some other geometric quantity of the melt zone. Such process variable is then compared with a desired value that can be experimentally determined, and the difference between the process variable and the desired value is used to adjust one or more adjustable process parameters.” – the difference between the process variable and the desired value is interpreted as an error), but
Kruth and Cheverton do not explicitly teach a moving average of the operative TEI.
However, Das teaches a moving average of the operative TEI (Claim 8, “filter the captured thermal image data through a short finite impulse response moving average filter; and
estimate a temperature distribution of the melt pool based on the filtered captured thermal image data”; Col. 48, lines 10-13, “To alleviate any issues with dropped frames and remove excess noise, a short finite impulse response (FIR) moving average filter can be implemented in the control schemes”).
Kruth, Cheverton, and Das are analogous art because they are from the same field of endeavor and contain functional similarities. They all relate to using laser powder bed additive manufacturing with real-time melt pool monitoring and feedback control.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control system for selective laser powder processing, as taught by Kruth and Cheverton, and incorporate using a moving average filter for thermal melt pool feedback data, as taught by Das.
One of ordinary skill in the art would have been motivated to “alleviate any issues with dropped frames and remove excess noise” as suggested by Das (Col. 48, lines 10-13).
Claim(s) 4, 6-7, and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kruth et al. USPGPUB 2009/0206065 A1 (hereinafter Kruth) in view of Cheverton et al. USPGPUB 2016/0114431 A1 (hereinafter Cheverton), and further in view of Penny et al. USPGPUB 2019/0118300 A1 (hereinafter Penny).
Regarding claim 4, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth and Cheverton do not explicitly teach wherein the controller is further configured to determine the control setpoint based on a calculation of an average dimensional error and a calculation of an average TEI corresponding to a plurality of experimental lines printed with the laser.
However, Penny teaches wherein the controller is further configured to determine the control setpoint based on a calculation of an average dimensional error and a calculation of an average TEI corresponding to a plurality of experimental lines printed with the laser (Par. [0105], “measuring before the nominal build process, e.g., running a test pattern in the corner of the build area to determine a transformation necessary to the build parameters, and/or a test pattern across the build area to calibrate out machine errors”; Par. [0111], “The SLM process may be directly calibrated using a pattern of known, systematically varied laser parameters … Optical interrogation, as described herein, can be used to assess the resulting quality of the scanned regions. The optimal set of scan parameters can then be selected to print the component or part ... the relationships between the scan parameters in the test pattern and the temperature distribution on the build surface, melt pool geometry, etc., can be assessed and used to adjust the scan parameters and/or the scan pattern for the remainder of the build.”; Par. [0010], “By way of non-limiting example, such parameters can include one or more of a temperature distribution, emissivity, spectrally resolved radiance measurements, band ratios, radiation transport characteristics, and a melt pool shape … The controller can be configured to determine statistical moments of the parameter(s), such as averages or variances, along spatial, temporal, or spectral dimensions of the recorded data. For example, mean melt pool temperature may be used to adjust laser power … dimensional accuracy may be improved by maximizing the spatial thermal gradient, such that the edge of the part is sharply defined.”; Par. [0017], “Each tile can typically be between about 2 millimeters and about 10 millimeters square, scanned, for example, as a series of parallel lines” – test pattern/scanned regions correspond to the claimed experimental lines because Penny teaches forming scanned regions as a series of parallel lines. Scanned region quality and calibrating out machine errors corresponds to dimensional error information. Penny also teaches calculating averages of measured parameters. Therefore, Penny teaches or suggests calculating an average dimensional error. Penny further teaches calculating an average TEI by measuring thermal/emission related parameters and determining statistical moments, such as averages, of those parameters. The selected optimal scan parameters correspond to determining the claimed control setpoint based on the average dimensional error and average TEI.).
Kruth, Cheverton, and Penny are analogous art because they are from the same field of endeavor and contain functional similarities. They all relate to using laser powder bed additive manufacturing using melt pool or build process sensing to control laser or build parameters.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control system for selective laser powder processing, as taught by Kruth and Cheverton, and incorporate an SLM calibration approach in which test pattern/scanned region data is used to determine calibration information for the build, as taught by Penny.
One of ordinary skill in the art would have been motivated to improve accuracy and efficiency of printing parts as suggested by Penny (Par. [0005]).
Regarding claim 6, the combination of Kruth, Cheverton and Penny teaches all the limitations of the base claims as outlined above.
Penny further teaches wherein the control setpoint corresponds to a minimum dimensional error tolerated for printing the target object, the minimum dimensional error being determined based on a correlation between the average dimensional error and the average TEI (Par. [0105], “running a test pattern in the corner of the build area to determine a transformation necessary to the build parameters, and/or a test pattern across the build area to calibrate out machine errors”; Par. [0111], “The SLM process may be directly calibrated using
a pattern of known, systematically varied laser parameters … Optical interrogation, as described herein, can be used to assess the resulting quality of the scanned regions. The optimal set of scan parameters can then be selected to print the component or part … the relationships between the scan parameters in the test pattern and the temperature distribution on the build surface, melt pool geometry, etc., can be assessed and used to adjust the scan parameters and/or the scan pattern for the remainder of the build.” – relationships between test pattern scan parameters, temperature distribution, and melt pool geometry suggests the claimed correlation between dimensional error information and TEI information because Penny optically interrogates the printed test pattern, assesses the quality of the scanned regions, and determines thermal/emission related information such as temperature distribution and melt pool geometry, and uses those relationships to select optimal scan parameters for printing the component. Penny further teaches that the measured thermal/emission related parameters may be processed as statistical moments, such as averages, including mean melt pool temperature.; Par. [0010], “such parameters can include one or more of a temperature distribution, emissivity, spectrally resolved radiance measurements, band ratios, radiation transport characteristics, and a melt pool shape … The controller can be configured to determine statistical moments of the parameter(s), such as averages or variances, along spatial, temporal, or spectral dimensions of the recorded data. For example, mean melt pool temperature may be used to adjust laser power”- Measured temperature distribution, melt pool geometry, radiance/emissivity, band ratios, and radiation-transport characteristics correspond to TEI-type thermal emission information. Statistical moments, including averages correspond to calculating average TEI-type information.).
Regarding claim 7, the combination of Kruth, Cheverton and Penny teaches all the limitations of the base claims as outlined above.
Penny further teaches wherein the plurality of experimental lines are printed with a plurality of different powers of the laser (Par. [0111], “The SLM process may be directly calibrated using a pattern of known, systematically varied laser parameters”; Par. [0009], “the build plan by the controller includes at least one of adjusting the scan speed, the laser power, the toolpath, the spot size, or the rate of heating or cooling” – systematically varied laser parameters include laser power as a parameter that can be adjusted).
Regarding claim 17, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth and Cheverton do not explicitly teach wherein the control setpoint is determined based on a calculation of an average dimensional error and a calculation of an average TEI corresponding to a plurality of experimental lines printed with the laser.
However, Penny teaches wherein the control setpoint is determined based on a calculation of an average dimensional error and a calculation of an average TEI corresponding to a plurality of experimental lines printed with the laser (Par. [0105], “measuring before the nominal build process, e.g., running a test pattern in the corner of the build area to determine a transformation necessary to the build parameters, and/or a test pattern across the build area to calibrate out machine errors”; Par. [0111], “The SLM process may be directly calibrated using a pattern of known, systematically varied laser parameters … Optical interrogation, as described herein, can be used to assess the resulting quality of the scanned regions. The optimal set of scan parameters can then be selected to print the component or part ... the relationships between the scan parameters in the test pattern and the temperature distribution on the build surface, melt pool geometry, etc., can be assessed and used to adjust the scan parameters and/or the scan pattern for the remainder of the build.”; Par. [0010], “By way of non-limiting example, such parameters can include one or more of a temperature distribution, emissivity, spectrally resolved radiance measurements, band ratios, radiation transport characteristics, and a melt pool shape … The controller can be configured to determine statistical moments of the parameter(s), such as averages or variances, along spatial, temporal, or spectral dimensions of the recorded data. For example, mean melt pool temperature may be used to adjust laser power … dimensional accuracy may be improved by maximizing the spatial thermal gradient, such that the edge of the part is sharply defined.”; Par. [0017], “Each tile can typically be between about 2 millimeters and about 10 millimeters square, scanned, for example, as a series of parallel lines” – test pattern/scanned regions correspond to the claimed experimental lines because Penny teaches forming scanned regions as a series of parallel lines. Scanned region quality and calibrating out machine errors corresponds to dimensional error information. Penny also teaches calculating averages of measured parameters. Therefore, Penny teaches or suggests calculating an average dimensional error. Penny further teaches calculating an average TEI by measuring thermal/emission related parameters and determining statistical moments, such as averages, of those parameters. The selected optimal scan parameters correspond to determining the claimed control setpoint based on the average dimensional error and average TEI.).
Kruth, Cheverton, and Penny are analogous art because they are from the same field of endeavor and contain functional similarities. They all relate to using laser powder bed additive manufacturing using melt pool or build process sensing to control laser or build parameters.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control system for selective laser powder processing, as taught by Kruth and Cheverton, and incorporate an SLM calibration approach in which test pattern/scanned region data is used to determine calibration information for the build, as taught by Penny.
One of ordinary skill in the art would have been motivated to improve accuracy and efficiency of printing parts as suggested by Penny (Par. [0005]).
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kruth et al. USPGPUB 2009/0206065 A1 (hereinafter Kruth) in view of Cheverton et al. USPGPUB 2016/0114431 A1 (hereinafter Cheverton) and Penny et al. USPGPUB 2019/0118300 A1 (hereinafter Penny), and further in view of Bauza et al. USPGPUB 2021/0107215 A1 (hereinafter Bauza).
Regarding claim 5, the combination of Kruth, Cheverton and Penny teaches all the limitations of the base claims as outlined above.
Kruth, Cheverton, and Penny do not explicitly teach wherein the average dimensional error is calculated based on a comparison of the printed experimental lines to one or more computer aided design (CAD) models corresponding to the plurality of experimental lines.
However, Bauza teaches comparing to one or more computer aided design (CAD) models (Par. [0017], “obtaining a three-dimensional measurement of a prior layer deposited immediately prior to the selected layer; determining a deviation between the three-dimensional measurement of the prior layer and the definition of the prior layer” – definition of the prior layer corresponds to a CAD-derived model; Par. [0025], “determining at least one of geometrical and dimensional characteristics of the defined material layer. Preferably, at least one of thickness, flatness, roughness and compliance with predefined nominal lateral dimensions”; Par. [0035], “verify conformance of the workpiece with the CAD data set.”).
Kruth, Cheverton, Penny, and Bauza are analogous art because they are from the same field of endeavor. They all relate to additive manufacturing systems using processes to improve printed part quality.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control and calibration system, as taught by Kruth, Cheverton, and Penny, and incorporate CAD-based deviation determination, in which measured printed geometry is compared to corresponding CAD-derived layer definitions to determine dimensional deviation, as taught by Bauza.
One of ordinary skill in the art would have been motivated to improve quality and cost efficiency, as suggested by Bauza (Par. [0009]).
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kruth et al. USPGPUB 2009/0206065 A1 (hereinafter Kruth) in view of Cheverton et al. USPGPUB 2016/0114431 A1 (hereinafter Cheverton), and further in view of Ettaieb et al. (Offline laser power modulation in LPBF additive manufacturing including kinematic and technological constraints, 2022) (hereinafter Ettaieb).
Regarding claim 8, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth and Cheverton do not explicitly teach wherein the laser comprises a minimum printing power and a maximum printing power, the minimum printing power corresponding to approximately 100 W and the maximum printing power corresponding to approximately 500 W.
However, Ettaieb teaches wherein the laser comprises a minimum printing power and a maximum printing power, the minimum printing power corresponding to approximately 100 W and the maximum printing power corresponding to approximately 500 W (Page 15, Par. 1, “The target temperature is set to 2300 K allowing the melting of all the powder bed. In order to respect the power limits imposed by the process window of Ti6Al4V and the machine constraints, the admissible power range is set to [100 W; 500 W].”).
Kruth, Cheverton, and Ettaieb are analogous art because they are from the same field of endeavor. They all relate to laser powder bed additive manufacturing systems in which laser power is controlled to improve print quality.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control and calibration system, as taught by Kruth and Cheverton, and incorporate a laser printing power range having a minimum of approximately 100 W and a maximum of approximately 500 W, as taught by Ettaieb.
One of ordinary skill in the art would have been motivated to keep the laser power within the admissible LPBF process window and machine constraints while performing laser power control, as suggested by Ettaieb (Page 15, Par. 1).
Claim(s) 9-10, 18-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kruth et al. USPGPUB 2009/0206065 A1 (hereinafter Kruth) in view of Cheverton et al. USPGPUB 2016/0114431 A1 (hereinafter Cheverton), and further in view of Smith US 4,894,527 (hereinafter Smith).
Regarding claim 9, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein the sensing system comprises a photodetector (Par. [0102], “A signal indicative for the area of the melt zone can also be recorded using an integrating detector like a photodiode with a large active area and an appropriate lens that focuses radiation emitted from the whole melt zone area around the laser spot on the active area of the integrating detector.”).
Kruth and Cheverton do not explicitly teach a variable resistor electrically coupled to the photodetector.
However, Smith teaches a variable resistor electrically coupled to a photodetector (Col. 1, lines 55-65, “The present invention therefore senses the presence of ambient light and, although using an analog signal generating light dependent resistor, generates a digital signal … This is accomplished by using a clock synchronized sample pulse to charge a capacitor through the light dependent resistor in series with a user adjustable potentiometer” – potentiometer is interpreted as a variable resistor).
Kruth, Cheverton, and Smith are analogous art because they contain functional similarities. They all relate to using optical sensing circuitry to generate electrical signals for control or threshold-based decision making.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control and calibration system, as taught by Kruth and Cheverton, and incorporate a light dependent resistor and user adjustable potentiometer circuit arrangement, as taught by Smith.
One of ordinary skill in the art would have been motivated to improve the adjustability and sensitivity of an optical sensing circuit, as suggested by Smith (Col. 1, lines 41-42).
Regarding claim 10, the combination of Kruth, Cheverton, and Smith teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein the photodetector is configured to detect the operative TEI from a powder bed during the print of the target object (Par. [0051], “detecting electromagnetic radiation emitted by or reflected from a moving observation zone on said powder surface, said moving observation zone comprising at least the incidence point of the laser beam on the powder surface”; Par. [0102], “A signal indicative for the area of the melt zone can also be recorded using an integrating detector like a photodiode with a large active area and an appropriate lens that focuses radiation emitted from the whole melt zone area around the laser spot on the active area of the integrating detector. The detector will thus measure variations in the melt zone temperature (according to Planck's law of spectral radiation) as well as variations in the melt zone area.”).
Kruth does not explicitly teach wherein the photodetector is a light-dependent resistor (LDR); and
the variable resistor is a potentiometer configurable to adjust a sensitivity range of the LDR.
However, Smith further teaches wherein:
the photodetector is a light-dependent resistor (LDR) (Col. 1, lines 55-58, “The present invention therefore senses the presence of ambient light and, although using an analog signal generating light dependent resistor, generates a digital signal”); and
the variable resistor is a potentiometer configurable to adjust a sensitivity range of the LDR (Col. 1, lines 62-65, “This is accomplished by using a clock synchronized sample pulse to charge a capacitor through the light dependent resistor in series with a user adjustable potentiometer”; Col. 3, lines 20-25, “adjustable resistor 14 is adjusted by the user so that at a particular ambient light level the charge time of capacitor 16 is the same as the time delay between the sample pulse generator output and the reference pulse generator output”).
Regarding claim 18, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein the sensing system comprises a photodetector (Par. [0102], “A signal indicative for the area of the melt zone can also be recorded using an integrating detector like a photodiode with a large active area and an appropriate lens that focuses radiation emitted from the whole melt zone area around the laser spot on the active area of the integrating detector.”).
Kruth and Cheverton do not explicitly teach a variable resistor electrically coupled to the photodetector.
However, Smith teaches a variable resistor electrically coupled to a photodetector (Col. 1, lines 55-65, “The present invention therefore senses the presence of ambient light and, although using an analog signal generating light dependent resistor, generates a digital signal … This is accomplished by using a clock synchronized sample pulse to charge a capacitor through the light dependent resistor in series with a user adjustable potentiometer” – potentiometer is interpreted as a variable resistor).
Kruth, Cheverton, and Smith are analogous art because they contain functional similarities. They all relate to using optical sensing circuitry to generate electrical signals for control or threshold-based decision making.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control and calibration system, as taught by Kruth and Cheverton, and incorporate a light dependent resistor and user adjustable potentiometer circuit arrangement, as taught by Smith.
One of ordinary skill in the art would have been motivated to improve the adjustability and sensitivity of an optical sensing circuit, as suggested by Smith (Col. 1, lines 41-42).
Regarding claim 19, the combination of Kruth, Cheverton, and Smith teaches all the limitations of the base claims as outlined above.
Kruth further teaches wherein the photodetector is configured to detect the operative TEI from a powder bed during the print of the target object (Par. [0051], “detecting electromagnetic radiation emitted by or reflected from a moving observation zone on said powder surface, said moving observation zone comprising at least the incidence point of the laser beam on the powder surface”; Par. [0102], “A signal indicative for the area of the melt zone can also be recorded using an integrating detector like a photodiode with a large active area and an appropriate lens that focuses radiation emitted from the whole melt zone area around the laser spot on the active area of the integrating detector. The detector will thus measure variations in the melt zone temperature (according to Planck's law of spectral radiation) as well as variations in the melt zone area.”).
Kruth does not explicitly teach wherein the photodetector is a light-dependent resistor (LDR); and
the variable resistor is a potentiometer configurable to adjust a sensitivity range of the LDR.
However, Smith further teaches wherein:
the photodetector is a light-dependent resistor (LDR) (Col. 1, lines 55-58, “The present invention therefore senses the presence of ambient light and, although using an analog signal generating light dependent resistor, generates a digital signal” – In the proposed combination, Smith’s LDR is used as the photodetector in Kruth’s sensing system, which detects the operative TEI emitted radiation from the powder bed during printing.); and
the variable resistor is a potentiometer configurable to adjust a sensitivity range of the LDR (Col. 1, lines 62-65, “This is accomplished by using a clock synchronized sample pulse to charge a capacitor through the light dependent resistor in series with a user adjustable potentiometer”; Col. 3, lines 20-25, “adjustable resistor 14 is adjusted by the user so that at a particular ambient light level the charge time of capacitor 16 is the same as the time delay between the sample pulse generator output and the reference pulse generator output”).
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kruth et al. USPGPUB 2009/0206065 A1 (hereinafter Kruth) in view of Cheverton et al. USPGPUB 2016/0114431 A1 (hereinafter Cheverton), and further in view of Zhou et al. USPGPUB 2020/0047500 A1 (hereinafter Zhou).
Regarding claim 13, the combination of Kruth and Cheverton teaches all the limitations of the base claims as outlined above.
Kruth and Cheverton do not explicitly teach wherein the controller comprises an Arduino based controller.
However, Zhou teaches wherein the controller comprises an Arduino based controller (Par. [0072] – [0073], “the microheater temperature is controlled by a PID controller. A closed-loop control may also be used which is based on the temperature resistivity relation of the microheater which acts as the temperature sensor … All data is processed by a microcontroller 600 which may be n 8-bit microcontroller board Arduino Mega … Based on the temperature-resistance relation, the temperature of the microheater is calculated, and the control voltage output is updated to keep the microheater temperature around the target temperature”).
Kruth, Cheverton, Zhou are analogous art because they contain functional similarities. They all relate to sensor feedback and a controller to update an operating condition to maintain or achieve a target process condition.
Therefore, at the time of effective filing date, it would have been obvious to a person of ordinary skill in the art to modify the above feedback control system, as taught by Kruth and Cheverton, and incorporate using an Arduino Mega microcontroller board, as taught by Zhou.
One of ordinary skill in the art would have been motivated to use an Arduino Mega as a known alternative controller implementation for additive manufacturing feedback control, as suggested by Zhou (Par. [0073]).
Citation of Pertinent Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Eonta et al. [USPGPUB 2021/0008621 A1] teaches a laser powder bed fusion (LPBF) system having layer-by-layer powder bed monitoring with a negative feedback control loop.
Gold [USPGPUB 2017/0246810 A1] teaches laser-based additive manufacturing processes for fabricating objects. In particular, the invention relates to a method for monitoring the quality of a work piece by using multivariate statistical process controls in the fabrication of objects using additive manufacturing processes.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PETER XU whose telephone number is (571)272-0792. The examiner can normally be reached Monday-Friday 9am-5pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Mohammad Ali can be reached at (571) 272-4105. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/PETER XU/ Examiner, Art Unit 2119
/MOHAMMAD ALI/ Supervisory Patent Examiner, Art Unit 2119
Prosecution Insights