US20180029309A1

US20180029309A1 - Method for a 3-d projection printing system and system thereof

Info

Publication number: US20180029309A1
Application number: US15/224,507
Authority: US
Inventors: Chao-Shun Chen; Chang-Chun Chen; Ming-fu Hsu
Original assignee: Young Optics Inc
Current assignee: Young Optics Inc
Priority date: 2016-07-29
Filing date: 2016-07-29
Publication date: 2018-02-01
Also published as: US11196876B2; US20190387110A1

Abstract

The embodiment of the present invention provides a method for a 3-D projection printing system and a system thereof, more particularly to a system adopts both ways of look-up table and interpolation method to calibrate. The embodiment of the present invention provides a portable calibration fixture system and a flexible 3-D projection printing system in order to improve calibration precision, facilitate calibration and printing operations, increase printing effect and save cost.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a method for a 3-D projection printing system and a system thereof, more particularly to a system adopts both the ways of look-up table and interpolation method to calibrate.

2. Description of the Prior Art

In case the lens of the projector is malfunctioned or deformed by some reasons as hot environment, falling down, etc., and/or the whole system happens tolerances while in assembly, the precisions for the system may not exist. Such system is applied to the field of 3-D printing very often, and the printing quality cannot be assured if aforesaid conditions do occur. Hence, an advanced 3-D projection system with an advanced calibration method are deemed to be a developed issue to the people skilled in the art.

SUMMARY OF THE INVENTION

One embodiment of the method for a 3-D projection printing system comprises the steps of: the 3-D projection printing system capturing a light-uniform device with a projected single second sample pattern thereon to obtain a second practical pattern, the second practical pattern being calibrated by a second camera look-up table to gain a calibrated pattern, a comparison of the calibrated pattern and the second sample pattern being a first projection look-up table which is transformed to a second projection look-up table with a projection resolution as a resulted projection look-up table, and the resulted projection look-up table being stored in the 3-D projection printing system; and the 3-D projection printing system using the resulted projection look-up table to calibrate a plurality of sliced printing files, and then the plurality of calibrated sliced printing files being used to engaged in a projection printing work.
An embodiment of the present invention provides a method for a 3-D projection printing system and a system thereof, more particularly to a system adopts both ways of look-up table and interpolation method to calibrate. The embodiment of the present invention provide a portable calibration fixture system and a flexible 3-D projection printing system in order to improve calibration precision, facilitate calibration and printing operations, increase printing effect and save cost.
Other and further features, advantages, and benefits of the invention will become apparent in the following description taken in conjunction with the following drawings. It is to be understood that the foregoing general description and following detailed description are exemplary and explanatory but are not to be restrictive of the invention. The accompanying drawings are incorporated in and constitute a part of this application and, together with the description, serve to explain the principles of the invention in general terms. Like numerals refer to like parts throughout the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, spirits, and advantages of the preferred embodiments of the present invention will be readily understood by the accompanying drawings and detailed descriptions, wherein:

FIGS. 1A and 1B illustrate a flow chart of a first preferred embodiment of the present invention;

FIGS. 2-1˜4 illustrate a plurality of practical views of calibration fixture steps of the embodiment of the present invention;

FIGS. 3-1˜5 illustrate a plurality of practical views of calibration projection steps of the embodiment of the present invention;

FIG. 4 illustrates a schematic system block of the first preferred embodiment of the present invention;

FIGS. 5A and 5B illustrate a flow chart of a second preferred embodiment of the present invention;

FIG. 6 illustrates a schematic system block of the second preferred embodiment of the present invention; and

FIG. 7 illustrates a schematic view of a calibration projection system.

DETAILED DESCRIPTION OF THE INVENTION

Following preferred embodiments and figures will be described in detail so as to achieve aforesaid objects.
According to FIG. 7, which illustrates a schematic view of a calibration projection system. The system includes a projector 51, a diffuser 53, a reflection mirror 55, a camera 56, and a computer 57. The projector 51 projects a projected image 54 onto the diffuser 53. The projected image 54 goes through the diffuser 53, and then to the reflection mirror 55. The reflection mirror 55 reflects the projected image 54 to the camera 56. The camera 56 captures the reflected projected image 54. Continuously, the captured image in the camera 56 is digitized and sent to the computer 57 via WIFI, USB, Bluetooth, cable, or the other wireless/wired methods.
Please refer to FIGS. 1A˜1B, FIGS. 2-1˜4, FIGS. 3-1˜5, and FIG. 4, which illustrate a flow chart, plural practical views of calibration fixture steps, plural practical views of calibration projection steps, and a schematic system block of the first preferred embodiment of the present invention. As shown in FIGS. 1A and 1B, the method includes the steps of:
(S1) providing a single first sample pattern 23 to a calibration fixture system 2;
(S2) a distortion correction calculation unit 121 of a calculation control system 12, which can be a computer for the preferred embodiment, of a 3-D projection printing system 1 using a camera 22 of the calibration fixture system 2 to capture the single first sample pattern 23, as shown in FIG. 2-1;
(S3) obtaining a first practical pattern, as shown in FIG. 2-2;
(S4) the distortion correction calculation unit 121 determining a plurality of displacement amounts of the first practical pattern and the single first sample pattern 23 to gain a first camera look-up table, as shown in FIG. 2-3;
(S5) the distortion correction calculation unit 121 using an interpolation method to transform the first camera look-up table into a second camera look-up table with a camera resolution, as shown in FIG. 2-4, wherein the view in FIG. 2-4 is larger than the view in FIG. 2-3, since the view in FIG. 2-4 is with a higher resolution;
(S6) the distortion correction calculation unit 121 storing the second camera look-up table;
(S7) removing the single first sample pattern 23 from the calibration fixture system 2;
(S8) providing a light-uniform device, which is a diffuser 21 for the preferred embodiment, to the calibration fixture system 2;
(S9) the distortion correction calculation unit 121 using the projection system 1111 of the printing control system 111 to project a single second sample pattern 24 to the diffuser 21, as shown in FIG. 3-1;
(S10) the distortion correction calculation unit 121 using the camera 22 to capture the single second sample pattern 24;
(S11) the distortion correction calculation unit 121 using the second camera look-up table to calibrate a second practical pattern obtained by that of the camera 22 capturing the single second sample pattern 24, as shown in FIG. 3-2;
(S12) obtaining a calibrated pattern, as shown in FIG. 3-3;
(S13) the distortion correction calculation unit 121 determining a plurality of displacement amounts of the calibrated pattern and the single second sample pattern 24 to gain a first projection look-up table, as shown in FIG. 3-4;
(S14) the distortion correction calculation unit 121 using the interpolation method to transform the first projection look-up table into a second projection look-up table 1121 with a projection resolution, as shown in FIG. 3-5, wherein the view in FIG. 3-5 is larger than the view in FIG. 3-4, since the view in FIG. 3-5 is with a higher resolution;
(S15) the distortion correction calculation unit 121 storing the second projection look-up table 1121 into a storing unit 112 of a 3-D printing system 11 of the 3-D projection printing system 1;
(S16) the distortion correction calculation unit 121 copying the second projection look-up table 1121 to a calculation control system 12 for becoming a third projection look-up table 122 as a resulted projection look-up table;
(S17) the distortion correction calculation unit 121 using the third projection look-up table 122 to calibrate a plurality of sliced printing files 13;
(S18) the distortion correction calculation unit 121 transmitting the plurality of calibrated sliced printing files 13 to a printing control system 111 of the 3-D printing system 11 of the 3-D projection printing system 1; and
(S19) a projection system 1111 of the printing control system 111 engaging in a projection printing work.
Again, please refer to FIG. 4, the calibration fixture system 2 includes the single first sample pattern 23, the projected single second sample pattern 24, the light-uniform device as the diffuser 21, wherein the camera 22 is used to capture the single first sample pattern 23 and the diffuser 21 with the projected single second sample pattern 24 thereon, and the reflection mirror 25 is used to reflect images of the camera 22 capturing the single first sample pattern 23 and the diffuser 21 with the projected single second sample pattern 24 thereon; and the 3-D projection printing system 1 has the 3-D printing system 11 and the calculation control system 12, wherein the 3-D printing system 11 has the printing control system 111 with the projection system 1111 and the storing unit 112 with the second projection look-up table 1121, and a computer (no shown in the FIG. 4) engages that of using the camera 22 to capture the single first sample pattern 23 in order to obtain the first practical pattern, determining the plurality of displacement amounts of the first practical pattern and the single first sample pattern 23 to gain the first camera look-up table, using the interpolation method to transform the first camera look-up table into the second camera look-up table with the camera resolution, storing the second camera look-up table, using the projection system 1111 of the printing control system 111 to project the single second sample pattern 24 to the diffuser 21, using the camera 22 to capture the single second sample pattern 24, using the second camera look-up table to calibrate the second practical pattern obtained by that of the camera 22 capturing the single second sample pattern 24 so as to obtain the calibrated pattern, determining the plurality of displacement amounts of the calibrated pattern and the single second sample pattern 24 to gain the first projection look-up table, using the interpolation method to transform the first projection look-up table into the second projection look-up table 112 with the projection resolution, storing the second projection look-up table 1121 into the storing unit 112 of the 3-D printing system 11 of the 3-D projection printing system 11, copying the second projection look-up table 1121 to the calculation control system 12 for becoming the third projection look-up table 122 as the resulted projection look-up table, using the resulted projection look-up table to calibrate the plurality of sliced printing files 13, and transmitting the plurality of calibrated sliced printing files 13 to the printing control system 111, and the projection system 1111 engaging in a projection printing work.
Please refer to FIGS. 5A˜5B, FIGS. 2-1˜4, FIGS. 3-1˜5, and FIG. 6, which illustrate a flow chart of a second preferred embodiment, plural practical views of calibration fixture steps, plural practical views of calibration projection steps, and a schematic system block of the second preferred embodiment of the present invention. As shown in FIGS. 5A and 5B, the method includes the steps of:
(S1′)˜(S15′) is similar substantially as (S1)˜(S15), so it is not described repeatedly here.
(S16′) the distortion correction calculation unit 1131′ using the second projection look-up table 1121′ as a resulted projection look-up table to calibrate a plurality of sliced printing files 13′;
(S17′) the distortion correction calculation unit 1131′ transmitting the plurality of calibrated sliced printing files 13′ to a printing control system 111′ of the 3-D printing system 11′ of the 3-D projection printing system 1′; and
(S18′) a projection system 1111′ of the print control system 111 engaging in a projection printing work.
Again, please refer to FIG. 6, the calibration fixture system 2′ is similar substantially as the calibration fixture system 2, so it is not described repeatedly here.
The 3-D projection printing system 1′ includes the 3-D printing system 11′ which has the printing control system 111′ with the projection system 1111′, the storing unit 112′ and the calculation control system 113′ with the distortion correction calculation unit 1131′, wherein the a computer (not shown in the FIG. 6) engages that of using the camera 22′ to capture the single first sample pattern 23′ in order to obtain the first practical pattern, determining a plurality of displacement amounts of the first practical pattern and the first sample pattern 23′ to gain the first camera look-up table, using an interpolation method to transform the first camera look-up table into the second camera look-up table with the camera resolution, storing the second camera look-up table, using the projection system 1111′ of the printing control system 111′ to project the single second sample pattern 24′ to the light-uniform device 21′, using the camera 22′ to capture the second sample pattern 24′, using the second camera look-up table to calibrate the second practical pattern obtained by that of the camera 22′ capturing the second sample pattern 24′ so as to obtain the calibrated pattern, determining a plurality of displacement amounts of the calibrated pattern and the second sample pattern 24′ to gain the first projection look-up table, using the interpolation method to transform the first projection look-up table into the second projection look-up table 1121′ with the projection resolution, storing the second projection look-up table 1121′ into the storing unit 112′ of the 3-D printing system 11′ of the 3-D projection printing system, using the second projection look-up table 1121′ as a resulted projection look-up table to calibrate the plurality of sliced printing files 13′, and transmitting the plurality of calibrated sliced printing files 13′ to a projection system 1111′ of a printing control system 111′ of a 3D printing system 11′ of the 3-D projection printing system 1, and the projection system 1111′ engaging in a projection printing work.
As it can be seen, the reflection mirror 25 for the first preferred embodiment and the reflection mirror 25′ for the second preferred embodiment can be neglected, hence the whole calibration fixture system may be decreased and lightened in volume and weight, since the calibration fixture system is portable. The camera 22 and 22′ for the two preferred embodiments must be with the function of higher resolutions, and can also be replaced by scanner or related image-capturing device.
With reference to FIG. 4 and FIG. 6, two communication interface 3 and 3′ for the first and second preferred embodiments play the roles to be communication media for the 3-D projection printing system 1 and the calculation control system 12 of the first preferred embodiment and the 3-D projection printing system 1′ and the calculation control system 113′ of the second preferred embodiment by way of cable, WIFI, USB, Blue Tooth, etc., or the other wireless/wired methods
According to FIG. 4, the calculation control system 12 not designed in the 3-D printing system 11 is to lower cost and raise printing speed, since the calculation control system 12 could be in a cloud system. Correspondingly, FIG. 6 represents that the calculation control system 113′ in the 3-D printing system 11′ is to increase convenience of printing.
Each of the first sample patterns 23 and 23′ and the second sample patterns 24 and 24′ is a single and plane pattern, that is to say, the complex procedures of calibration is simplified, and the problem for depth of field may not be occurred, since only one single pattern is vertically faced to the camera. Further, the projected image/pattern is calibrated by means of the look-up table and the interpolation method, therefore time for calculation is saved and image jags phenomena may not happen. Practically, the 3-D printing system 11/11′ could be a 3-D printer; the printing control system 111/111′ could be a projector, a laser control system, a CPU, an FPGA, etc.; the projection system 1111′ could be a projector, etc.; the storing unit 112/112′ could be an SD card, an SDRAM, a flash memory, etc.; the calculation control system 12/113′ could be a computer, a station, a CPU, a software, a firmware, or a network system, etc.; the distortion correction calculation unit 121/1131′ could be hardware as FPGA (Field-Programmable Gate Array) accelerator, GPU (Graphic Processor Unit), etc., or software/firmware as C-code program, etc.; the calibration fixture system 2/2′ could be a jig; the light-uniform device 21/21′ could be a diffuser. In addition, the calibration fixture system 2/2′ as a jig could be portable.
There are two results to prove what the steps (S1) to (S6), the steps (S1′) to (S6′), the steps (S8) to (S14), and the steps (S8′) to (S14′) of the embodiments have done is better. That is, the RMS (Root Mean Square) results of before and after going through the steps (S1) to (S6) or the steps (S1′) to (S6′) are 80.3 and 2.2; comparatively, the RMS (Root Mean Square) results of before and after going through the steps (S8) to (S14) or the steps (S8′) to (S14′) are 31.5 and 2.0.
Although the invention has been disclosed and illustrated with reference to particular embodiments, the principles involved are susceptible for use in numerous other embodiments that will be apparent to persons skilled in the art. This invention is, therefore, to be limited only as indicated by the scope of the appended claims

Claims

What is claimed is:

1. A method for a 3-D projection printing system comprising

using a resulted projection look-up table to calibrate a plurality of sliced printing files, and then the plurality of calibrated sliced printing files being used to engage in a projection printing work, wherein the resulted projection look-up table is produced from a projected single second sample pattern.

2. The method for the 3-D projection printing system according to claim 1 further comprising the steps of:

providing a light-uniform device to a calibration fixture system;

projecting a single second sample pattern to the light-uniform device;

capturing the projected single second sample pattern;

using a second camera look-up table to calibrate a second practical pattern obtained by capturing the projected single second sample pattern;

obtaining a calibrated pattern;

determining a plurality of displacement amounts of the calibrated pattern and the single second sample pattern to gain a first projection look-up table; and

using the interpolation method to transform the first projection look-up table into a second projection look-up table, as the resulted projection look-up table.

3. The method for the 3-D projection printing system according to claim 2 further comprising the steps of:

providing a single first sample pattern to the calibration fixture system;

obtaining a first practical pattern by capturing the single first sample pattern;

determining a plurality of displacement amounts of the first practical pattern and the single first sample pattern to gain a first camera look-up table; and

using an interpolation method to transform the first camera look-up table into the second camera look-up table.

4. The method for the 3-D projection printing system according to claim 3 further comprising the steps of:

copying the second projection look-up table to a calculation control system for becoming the resulted projection look-up table;

using the resulted projection look-up table to calibrate the plurality of sliced printing files;

transmitting the plurality of calibrated sliced printing files to a printing control system of a 3-D printing system; and

engaging in the projection printing work.

5. The method for the 3-D projection printing system according to claim 3 further comprising the steps of:

using the second projection look-up table as the resulted projection look-up table to calibrate the plurality of sliced printing files;

transmitting the plurality of calibrated sliced printing files to a printing control system of the 3-D printing system; and

engaging in the projection printing work.

6. The method for the 3-D projection printing system according to claim 2, wherein the light-uniform device is a diffuser.

7. The method for the 3-D projection printing system according to claim 4, wherein the calculation control system is a computer, a station, a CPU, a software, a firmware, or a network system.

8. The method for the 3-D projection printing system according to claim 2, wherein the calibration fixture system is portable.

9. A 3-D projection printing system comprising:

a 3-D printing system being used to engage in a projection printing work; and

a calculation control system being used to calibrate a plurality of sliced printing files by a resulted projection look-up table, and the plurality of calibrated sliced printing files sent to the 3-D printing system, wherein the resulted projection look-up table is produced from a projected single second sample pattern.

10. The 3-D projection printing system according to claim 9 further comprising:

a camera, used to capturing a single first sample pattern or the light-uniform device with the projected single second sample pattern thereon.

11. The 3-D projection printing system according to claim 10 further comprising:

a reflection mirror, used to reflect images of the camera capturing the single first sample pattern or the light-uniform device with the projected single second sample pattern thereon.

12. The 3-D projection printing system according to claim 10 further comprising:

a 3-D printing system, having a printing control system and a storing unit, wherein the printing control system has a projection system; and

a calculation control system, having a distortion correction calculation unit, wherein a computer engages that of using the camera to capture the single first sample pattern in order to obtain a first practical pattern, determining a plurality of displacement amounts of the first practical pattern and the single first sample pattern to gain a first camera look-up table, using an interpolation method to transform the first camera look-up table into a second camera look-up table with the camera resolution, storing the second camera look-up table, using the projection system of the printing control system to project the single second sample pattern to the light-uniform device, using the camera to capture the projected single second sample pattern, using the second camera look-up table to calibrate the second practical pattern obtained by that of the camera capturing the projected single second sample pattern so as to obtain the calibrated pattern, determining a plurality of displacement amounts of the calibrated pattern and the single second sample pattern to gain the first projection look-up table, using the interpolation method to transform the first projection look-up table into the second projection look-up table with the projection resolution, wherein the calculation control system stores a second projection look-up table into the storing unit, copies the second projection look-up table to the calculation control system for becoming a third projection look-up table as the resulted projection look-up table, uses the third projection look-up table to calibrate the plurality of sliced printing files, and transmits the plurality of calibrated sliced printing files to the printing control system, and the projection system engages in the projection printing work.

13. The 3-D projection printing system according to claim 10 further comprising:

a 3-D printing system, having a printing control system with a projection system, a storing unit and a calculation control system with a distortion correction calculation unit;

wherein a computer engages that of using the camera to capture the single first sample pattern in order to obtain a first practical pattern, determining a plurality of displacement amounts of the first practical pattern and the single first sample pattern to gain a first camera look-up table, using an interpolation method to transform the first camera look-up table into a second camera look-up table with the camera resolution, storing the second camera look-up table, using the projection system of the printing control system to project the single second sample pattern to the light-uniform device, using the camera to capture the projected single second sample pattern, using the second camera look-up table to calibrate the second practical pattern obtained by that of the camera capturing the projected single second sample pattern so as to obtain the calibrated pattern, determining a plurality of displacement amounts of the calibrated pattern and the single second sample pattern to gain the first projection look-up table, using the interpolation method to transform the first projection look-up table into a second projection look-up table with the projection resolution, wherein a calculation control system stores the second projection look-up table into the storing unit, uses the second projection look-up table as a resulted projection look-up table to calibrate the plurality of sliced printing files, and transmits the plurality of calibrated sliced printing files to the projection system, and the projection system engages in the projection printing work.

14. The 3-D projection printing system according to claim 10, wherein the light-uniform device is a diffuser.

15. The 3-D projection printing system according to claim 12, wherein the calculation control system is a computer, a station, a CPU, a software, a firmware, or a network system.

16. A 3-D projection printing system comprising:

a 3-D printer being used to engage in a projection printing work; and

a first computer being used to calibrate a plurality of sliced printing files by a resulted projection look-up table, and the plurality of calibrated sliced printing files sent to the 3-D printer, wherein the resulted projection look-up table is produced from a projected single second sample pattern.

17. The 3-D projection printing system according to claim 16 further comprising:

a camera, used to capturing a single first sample pattern or the diffuser with the projected single second sample pattern thereon.

18. The 3-D projection printing system according to claim 17 further comprising:

a reflection mirror, used to reflect images of the camera capturing the single first sample pattern or the diffuser with the projected single second sample pattern thereon.

19. The 3-D projection printing system according to claim 17 further comprising:

a 3-D printer, having a CPU and a flash memory, wherein the 3-D printer has a projector; and

the first computer, having an FPGA (Field-Programmable Gate Array) accelerator, wherein a second computer engages that of using the camera to capture the single first sample pattern in order to obtain a first practical pattern, determining a plurality of displacement amounts of the first practical pattern and the single first sample pattern to gain a first camera look-up table, using an interpolation method to transform the first camera look-up table into a second camera look-up table with the camera resolution, storing the second camera look-up table, using the projector to project the single second sample pattern to the diffuser, using the camera to capture the second projected single sample pattern, using the second camera look-up table to calibrate the second practical pattern obtained by that of the camera capturing the projected single second sample pattern so as to obtain the calibrated pattern, determining a plurality of displacement amounts of the calibrated pattern and the single second sample pattern to gain the first projection look-up table, using the interpolation method to transform the first projection look-up table into the second projection look-up table with the projection resolution, wherein the first computer stores a second projection look-up table into the flash memory, copies the second projection look-up table to the first computer for becoming a third projection look-up table as the resulted projection look-up table, uses the third projection look-up table to calibrate the plurality of sliced printing files, and transmits the plurality of calibrated sliced printing files to the CPU, and the projector of the 3-D printer engaging in the projection printing work.

20. The 3-D projection printing system according to claim 17 further comprising:

a 3-D printer, having a CPU, a projector, a flash memory and an FPGA (Field-Programmable Gate Array) accelerator;

wherein a second computer engages that of using the camera to capture the single first sample pattern in order to obtain a first practical pattern, determining a plurality of displacement amounts of the first practical pattern and the single first sample pattern to gain a first camera look-up table, using an interpolation method to transform the first camera look-up table into a second camera look-up table with the camera resolution, storing the second camera look-up table, using the projector to project the single second sample pattern to the diffuser, using the camera to capture the projected single second sample pattern, using the second camera look-up table to calibrate the second practical pattern obtained by that of the camera capturing the projected single second sample pattern so as to obtain the calibrated pattern, determining a plurality of displacement amounts of the calibrated pattern and the single second sample pattern to gain the first projection look-up table, using the interpolation method to transform the first projection look-up table into a second projection look-up table with the projection resolution, storing the second projection look-up table into the flash memory, using the second projection look-up table as a resulted projection look-up table to calibrate the plurality of sliced printing files, and transmitting the plurality of calibrated sliced printing files to the CPU, and the projector of the 3-D printer engaging in the projection printing work.