CN111497241B

CN111497241B - DLP type 3D printing system

Info

Publication number: CN111497241B
Application number: CN202010608133.2A
Authority: CN
Inventors: 王文斌; 周志永
Original assignee: Suzhou Boli New Material Technology Co ltd
Current assignee: Yichun Boli Intelligent Manufacturing Research Institute Co.,Ltd.
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2020-09-18
Anticipated expiration: 2040-06-30
Also published as: CN111497241A

Abstract

The invention relates to a DLP type 3D printing system, comprising: the control device is set to produce the slice image for transmitting to the DLP projection optical machine by a method of cutting the three-dimensional printing model into at least a first printing section and a second printing section, and decomposing slices corresponding to thin layers in the first and second printing sections into a first sub-slice image and a second sub-slice image which are different in size. The 3D printing system disclosed by the invention is wide in breadth and high in printing speed.

Description

DLP type 3D printing system

Technical Field

The invention relates to the technical field of 3D printing, in particular to a DLP type 3D printing system.

Background

In the dental field, a dental restoration model mainly uses a DLP type 3D printer with surface exposure at present, such as an optical machine or a projector, to project a layer image of one layer at a time at the bottom, a printing platform pulls and peels a molded article on a release film, and the printing precision requirement of the restoration model is higher.

Although the 3D printing process is widely used for rapid forming, the requirement on forming accuracy of a dental restoration model is high, the forming accuracy is limited by the resolution of an optical machine or a projector in the existing DLP type 3D printing system, and the forming breadth is small; meanwhile, because the release film is stripped and drawn each time, the forming breadth is smaller due to the overlarge material elasticity and drawing force of the release film; thus, there remains a challenge to improve the formation web of the printer.

While DLP type 3D printing systems have advanced in various ways, there is still a desire by consumers for DLP type 3D printers in the marketplace that enable rapid and minimal cost production of dental restoration models or other similar workpieces.

Disclosure of Invention

The invention aims to provide a DLP type 3D printing system which can realize rapid workpiece printing on the basis of meeting the precision requirement.

In order to achieve the purpose, the invention adopts the following technical scheme: a DLP-type 3D printing system comprising: a resin supply device comprising a resin tank for storing a liquid photosensitive resin material, a molding carriage disposed in the resin tank and movable in a printing direction, the molding carriage configured to hold a workpiece printed by the printing system on the carriage; a DLP light projector arranged to project a light image toward the shaping stage to effect curing of the photosensitive resin material on the shaping stage, the DLP light projector being configured to be movable in at least one XY plane perpendicular to a printing direction; control means for transferring a slice image corresponding to an optical image to the DLP projector engine and for controlling the DLP projector engine to move within the XY plane based on the transferred slice image, the control means being configured to create the slice image for transfer to the DLP projector engine by performing the steps of:

s1, determining a three-dimensional printing model of the shape of the workpiece to be printed based on imaging data of the workpiece to be printed, cutting the three-dimensional printing model into at least a first printing section and a second printing section by using a plurality of cutting surfaces parallel to the XY plane, and respectively cutting the first printing section and the second printing section into a plurality of slices parallel to the XY plane by using a plurality of cutting surfaces parallel to the XY plane and combining with the single-time printing thickness of the printing system, wherein each slice represents a thin layer on the three-dimensional computer model;

and S2, cutting each slice in the first printing section by using a plurality of cutting planes intersected with the XY plane to decompose the corresponding slice into a plurality of first sub-slice images with a first size, and cutting each slice in the second printing section by using a plurality of cutting planes intersected with the XY plane to decompose the corresponding slice into a plurality of second sub-slice images with a second size, wherein the first size is larger than the second size, the first sub-slice image and the second sub-slice image are both smaller than or equal to the resolution of the DLP projection optical machine, and the first sub-slice image and the second sub-slice image are slice images for transmitting to the DLP projection optical machine.

In the above technical solution, preferably, the forming carrier includes a porous mesh plate extending along the XY plane.

In the above technical solution, preferably, the resin supply device further includes a scraper located above the forming carrier; the squeegee is configured to be movable in the XY plane to squeegee the liquid photosensitive resin material on the molding stage.

In the foregoing technical solution, preferably, the DLP type 3D printing system includes a moving device, the DLP projector is mounted on the moving device by a bracket, the moving device is configured to drive the DLP projector to move along a first moving direction and a second moving direction, and the first moving direction and the second moving direction are perpendicular to each other.

In the above technical solution, preferably, the moving device includes a first lead screw transmission mechanism and a second lead screw transmission mechanism; the first lead screw transmission mechanism comprises a first lead screw which is rotatably arranged and a first nut which is connected with the first lead screw and can move in a translation way along the first lead screw, and the first nut is configured to drive the bracket to move in a first moving direction; the second lead screw drive includes a rotatably mounted second lead screw and a second nut engaged with the second lead screw for translational movement along the second lead screw, the second nut being configured to move the carriage in the second direction of movement.

In the above technical solution, preferably, the moving device includes a third screw transmission mechanism; the third lead screw drive includes a rotatably mounted third lead screw and a third nut coupled to the third lead screw for translational movement along the third lead screw, the third nut being configured to move the carriage in the printing direction.

The 3D printing system of the invention has wide breadth and high printing speed, and the detailed content will be described in the specific implementation mode by combining with the embodiment.

Drawings

Fig. 1 is a schematic structural diagram of a DLP type 3D printing system according to an embodiment of the present invention;

fig. 2 is a schematic flow chart of a control device according to an embodiment of the present invention when forming a slice image;

FIG. 3 is a schematic illustration of a three-dimensional printed composite model assembled from 9 dental restoration models to be printed;

FIG. 4 is a schematic diagram of the control apparatus provided in accordance with an embodiment of the present invention to cut the three-dimensional printing combined model of FIG. 3 with several cutting planes parallel to the XY plane and in combination with a single printing thickness of the printing system to form a cut sheet;

fig. 5 is a schematic diagram illustrating that the control device segments a first slice in the gum printing interval section into a plurality of first sub-slice images according to the embodiment of the present invention;

fig. 6 is a schematic diagram of the control device segmenting a second slice in the dental printing interval section to obtain a plurality of second sub-slice images according to the embodiment of the invention.

Wherein: 100. a printing system; 10. a resin supply device; 11. a resin tank; 12. forming a bearing table; 121. a porous mesh plate; 122. a squeegee; 123. a lifting mechanism; 124. a translation mechanism; 20. DLP projection light machine; 30. a control device; 31. a controller; 32. a control screen; 40. a mobile device; 41. an X-axis lead screw transmission mechanism; 42. a Y-axis lead screw transmission mechanism; 43. a Z-axis lead screw transmission mechanism; 411. an X-axis motor; 412. an X-axis lead screw; 421. a Y-axis motor; 422. a Y-axis lead screw; 431. a Z-axis motor; 432. a Z-axis lead screw; 1001. a first XY plane; 1002. a second XY plane; 1003. a third XY plane; 501. three-dimensional printing the model; 50. printing the combined model in three dimensions; 60. a gap; 51. a gum printing block section; 52. a dental printing block section; 511. a first slice; 521. second slicing; 5111. a first sub-slice image; 5211. a second sub-slice image; 701. a first cutting surface; 702. a second cut surface; 801. a third cut surface; 802. and a fourth cut surface.

Detailed Description

The present invention is further illustrated by the following specific embodiments, which are specific embodiments of the present invention.

The DLP type 3D printing system 100 shown in fig. 1 includes a resin supply device 10, a DLP projector engine 20 with a light source, and a control device 30.

The resin supply device 10 includes a resin tank 11 for storing a liquid photosensitive resin material, and a molding stage 12 disposed in the resin tank 11 and movable in a printing direction (i.e., a Z-axis direction). The forming carriage 12 includes a perforated web 121 extending along a first XY plane 1001 (i.e., a plane perpendicular to the printing direction). The porous screen 121 has a first area S1, by which the porous screen 121 can simultaneously hold a plurality of workpieces printed by the printing system 100 on the porous screen 121, via the first area S1. A squeegee 122 is disposed above the porous screen plate 121, the squeegee 122 is configured to be movable in the third XY plane 1003 by the translation mechanism 124, and the movable squeegee 122 is used to squeegee the liquid photosensitive resin material on the porous screen plate 121. The shaping carriage 12 in this example is mounted on a lifting mechanism 123 that can be raised and lowered along the Z-axis, the lifting mechanism 123 in this example being a lead screw drive. The multi-hole screen 121 can be lifted up and down along with the position of the printing layer by the lifting mechanism 123, that is, after the projection of each layer of the DLP projector 20 is completed, a signal is output to the control device 30, a motion signal is output to the lifting mechanism 123 through the control device 30, the multi-hole screen 121 is lowered by a height corresponding to the printing layer, and the resin material is replenished with resin upwards from the peripheral edge and the holes of the multi-hole screen 121. Then the scraper 122 is driven by the translation mechanism 124 to move a width-size distance of the porous screen 121, so as to realize the replenishment and the spreading of the liquid photosensitive resin material in the next printing layer, and then a feedback signal is sent to the control device 30 to instruct the optical DLP projection light machine 20 to perform the movement and the projection operation related to the next layer thickness.

The DLP projection light 20 is arranged to be able to project a light image towards the molding stage 12 to effect curing of the photosensitive resin material located on the molding stage 12.

In this embodiment, the DLP projector 20 is mounted on the moving device 40 by a bracket (not shown), and the moving device 40 is configured to drive the DLP projector 20 to move along the X-axis direction, the Y-axis direction and the Z-axis direction, respectively. The DLP light projector 20 is driven by the moving device 40 to be able to translate in a second XY plane 1002 with a second area S2, where the second area S2 is greater than or equal to the first area S1 of the multi-aperture screen 121, that is, the area of the moving area of the DLP light projector 20 is greater than the area of the multi-aperture screen 121; this enables a wider workpiece or a plurality of smaller size workpieces to be printed simultaneously even with a low resolution DLP projector.

The moving device 40 includes an X-axis screw transmission mechanism 41, a Y-axis screw transmission mechanism 42, and a Z-axis screw transmission mechanism 43. The X-axis screw transmission mechanism 41 includes an X-axis motor 411, an X-axis screw 412 rotatably mounted by the X-axis motor 411, and a first nut (not shown) engaged with the X-axis screw 412 and movable in translation along the X-axis screw 412, the first nut being configured to move the DLP projector 20 in the X-axis direction. The Y-axis screw transmission mechanism 42 includes a Y-axis motor 421, a Y-axis screw 422 driven by the Y-axis motor 421 to be rotatably mounted, and a second nut (not shown in the figure) engaged with the Y-axis screw 422 and translationally movable along the Y-axis screw 422, the second nut being configured to drive the DLP projector engine 20 to move in the Y-axis direction. The Z-axis screw transmission mechanism 43 includes a Z-axis motor 431, a Z-axis screw 432 rotatably mounted by the Z-axis motor 431, and a third nut (not shown) engaged with the Z-axis screw 432 and movable in translation along the Z-axis screw 432, the third nut being configured to move the DLP projector engine 20 in the Z-axis direction. The DLP projection light machine 20 moves in three dimensions in XYZ directions, so that the increase of the forming breadth is realized, the precision is adjustable, the operation is simple, the precision is high, and the application range is wide.

In other embodiments, the moving device may be replaced by a non-lead screw transmission mechanism, such as a gear moving mechanism, a belt moving mechanism, etc., which can drive the DLP projector to move precisely in the X-axis, Y-axis and Z-axis directions.

The control device 30 is composed of a controller 31 and a control screen 32, and the controller 31 is respectively connected with the lifting mechanism 123, the translation mechanism 124, the motors on the moving device 40 and the DLP projector 20 in signal communication and controls the operation of the components. In this example, the control device 30, in addition to controlling the operation of the above components, also needs to create a slice image for transmission to the DLP projector 20, and is configured to form a slice pattern by performing the following steps, as shown in fig. 2:

the method comprises the following steps: determining a three-dimensional printing model of the shape of the workpiece to be printed based on imaging data of the workpiece to be printed, and cutting the three-dimensional printing model into a first printing section and a second printing section by using a cutting surface parallel to the XY plane (in the example, the printing system prints along the Z-axis direction vertical to the XY plane); in other embodiments, the three-dimensional printing model can also be cut into printing sections with the number of which is greater than or equal to 3 by utilizing a plurality of cutting surfaces parallel to the XY plane so as to meet the printing precision requirement;

step two: cutting the first printing interval and the second printing interval into a plurality of first slices and a plurality of second slices respectively by using a plurality of cutting surfaces parallel to the XY plane and combining the single-time printing thickness of the printing system 100, wherein each first slice and each second slice are parallel to the XY plane and represent a thin layer on the three-dimensional computer model;

step three: cutting each first slice corresponding to the first printing block section by using a plurality of cutting surfaces intersected with the XY plane to decompose each first slice into a plurality of first sub-slice images with a first size, and dividing each second slice corresponding to the second printing block section by using a plurality of cutting surfaces intersected with the XY plane to decompose each second slice into a plurality of second sub-slice images with a second size, wherein the first size is larger than the second size, and the first sub-slice image and the second sub-slice image are both smaller than or equal to the resolution of the DLP projection optical machine 20; the first sub-slice image and the second sub-slice image are slice images transmitted to the DLP projection optical machine; wherein, several cutting surfaces mentioned in the third step may be surfaces perpendicular to the XY plane, or surfaces intersecting the XY plane at an angle different from 90 °.

After all the first sub-slice images and the second sub-slice images are manufactured, the control device 30 sequentially transmits each sub-slice image to the DLP projector 20 to print the layer corresponding to the corresponding sub-picture until all the layers are printed.

The following describes the whole operation process of the 3D printing system in detail by taking the simultaneous batch printing of 9 dental restoration models as an example.

First, the slice image transmitted to the DLP projector 20 is prepared by the control device 30:

s1, as shown in fig. 3, inputting a batch of three-dimensional printing models 501 determined based on each imaging data of 9 dental restoration models to be printed to the control device 30, the control device 30 arranging the batch of three-dimensional printing models 501 in the same three-dimensional space to construct a new three-dimensional printing combination model 50 with a larger width, wherein a gap 60 is left between two adjacent three-dimensional printing models during arrangement, and the three-dimensional printing models 501 corresponding to all the 9 dental restoration models printed in batch are arranged in the same direction.

S2, cutting the three-dimensional printing combined model 50 into a lower gum printing block section 51 and an upper tooth printing block section 52 by using a cutting surface parallel to the XY plane, wherein the cutting method of the step can be cutting according to different printing precision requirements of different heights of the dental restoration model, and the lower part of the dental restoration model corresponds to the gum of the patient, so that the precision requirement is low, and the dental restoration model can be printed quickly; the precision requirement of the upper part of the dental restoration model corresponding to the occlusal surface of the teeth of the patient is high, and careful printing is needed.

S3, cutting the gum-printing block section 51 and the tooth-printing block section 52 into a plurality of first slices 511 and a plurality of second slices 521 respectively by using a plurality of cutting planes parallel to the XY plane in combination with the single-time printing thickness of the printing system 100, as shown in fig. 4, each first slice 511 is parallel to the XY plane and represents a thin layer of the three-dimensional printing combined model 50 corresponding to the gum-printing block section 51, and each second slice 521 is also parallel to the XY plane and represents a thin layer of the three-dimensional printing combined model 50 corresponding to the tooth-printing block section 52. Cutting each first cut piece 511 corresponding to the gum-printed section 51 with a plurality of cutting planes intersecting the XY plane to decompose each first cut piece 511 into a first sub-cut piece image 5111 having a first size, cutting each second cut piece 521 cut by the tooth-printed section 52 with a plurality of cutting planes intersecting the XY plane to divide each second cut piece 521 into a second sub-cut piece image 5211 having a second size; wherein the first size is greater than the second size; as shown in fig. 5, taking a first slice 511 parallel to the XY plane as an example in this example, the slice is divided into 9 first sub-slice images 5111 by 2 first cut planes 701 perpendicular to the XY plane and extending along the XZ plane and 2 second cut planes 702 perpendicular to the XY plane and extending along the YZ plane; as shown in fig. 6, taking as an example a second slice 521 parallel to the XY plane in this example, the second slice 521 is divided into 16 second sub-slice images 5211 by 3 third cut surfaces 801 perpendicular to the XY plane and extending along the XZ plane and 3 fourth cut surfaces 802 perpendicular to the XY plane and extending along the YZ plane. The first sub-slice image 5111 and the second sub-slice image 5211 are each less than or equal to the resolution of the DLP projection light 20; the first sub-slice image 5111 and the second sub-slice image 5211 are slice images transmitted to the DLP projector engine 20, and the position coordinates of the sub-pictures should be marked when the first sub-slice image 5111 and the second sub-slice image 5211 are output.

Again, the control device 30 edits the printing order of the first sub-slice images 5111 corresponding to each printing layer in each printing layer according to the position coordinates with respect to the first sub-slice images 5111 corresponding to each printing layer in the gum printing interval section 51, and edits the printing order of the second sub-slice images 5211 corresponding to each printing layer in the tooth printing interval section 52 according to the position coordinates with respect to the second sub-slice images 5211 corresponding to each printing layer.

Thirdly, the control device 30 controls the moving device 40 and the DLP projector 20 to perform the printing sequence as follows: the control device 30 outputs all the first sub-slice images 5111 corresponding to the start layer of the gum printing interval section 51 to the DLP projector 20, and the control device 30 controls the DLP projector 20 to move to the corresponding position according to the edited printing sequence and perform projection after reaching the corresponding position; when the DLP projection optical machine 20 finishes projecting all the first sub-slice images 5111 of the current slice layer, the lifting mechanism 123 drives the forming bearing table 12 to move downward, that is, each layer of printing finished porous screen 121 descends by the height corresponding to a single slice layer, resin materials are supplemented with resin from the peripheral edge and the meshes upward, and meanwhile, the scraper 122 moves by a breadth size, so that the resin supplementation and the leveling of the next printing rhythm are realized together; the printing of the second layer of the gum printing block 51 is then continued until all layers of the gum printing block 51 are printed.

Fourth, the control device 30 completes the printing of the tooth printing block 52 according to the same method as the gum printing block 51 described above.

Finally, the printing of a plurality of dental restoration models can be completed simultaneously by demolding from the forming bearing table 12.

In the printing process, when the DLP light projector 20 projects each sub-slice image, the control device 30 needs to adjust or move the light projector 20 to meet the requirement of the resolution of the projection of the corresponding sub-slice image.

According to the 3D printing system, the slices of different layers are decomposed into the sub-slice images with different sizes, so that different printing accuracies of different layers are realized.

While the disclosure has been described with reference to what are presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, it should be understood that the foregoing embodiments are exemplary and are not intended to limit the disclosure in any way.

Claims

1. A DLP type 3D printing system, comprising:

a resin supply device comprising a resin tank for storing a liquid photosensitive resin material, a molding carriage disposed in the resin tank and movable in a printing direction, the molding carriage configured to hold a workpiece printed by the printing system on the carriage;

a DLP light projector arranged to project a light image toward the shaping stage to effect curing of the photosensitive resin material on the shaping stage, the DLP light projector being configured to be movable in at least one XY plane perpendicular to a printing direction;

control means for transferring a slice image corresponding to an optical image to the DLP projector engine and for controlling the DLP projector engine to move within the XY plane based on the transferred slice image, the control means being configured to create the slice image for transfer to the DLP projector engine by performing the steps of:

and S2, cutting each slice in the first printing section by a plurality of cutting planes intersected with the XY plane to decompose the corresponding slice into a plurality of first sub-slice images with a first size, and cutting each slice in the second printing section by a plurality of cutting planes intersected with the XY plane to decompose the corresponding slice into a plurality of second sub-slice images with a second size, wherein the first size is larger than the second size, the first sub-slice image and the second sub-slice image are both smaller than or equal to the resolution of the DLP projection optical machine, and the first sub-slice image and the second sub-slice image are slice images for transmitting to the DLP projection optical machine.

2. The DLP-type 3D printing system according to claim 1, wherein said shaping carriage comprises a perforated screen extending along said XY plane.

3. The DLP type 3D printing system according to claim 1, wherein said resin supply means further comprises a squeegee located above said molding carriage; the squeegee is configured to be movable in the XY plane to squeegee the liquid photosensitive resin material on the molding stage.

4. The DLP type 3D printing system according to claim 1, wherein said DLP type 3D printing system comprises a moving device, said DLP projector being mounted on said moving device by a bracket, said moving device being configured to move said DLP projector in a first moving direction and in a second moving direction, said first moving direction and said second moving direction being perpendicular to each other.

5. The DLP-type 3D printing system according to claim 4, wherein said moving means comprises a first screw drive and a second screw drive; the first lead screw transmission mechanism comprises a first lead screw which is rotatably arranged and a first nut which is connected with the first lead screw and can move in a translation way along the first lead screw, and the first nut is configured to drive the bracket to move in a first moving direction; the second lead screw drive includes a rotatably mounted second lead screw and a second nut engaged with the second lead screw for translational movement along the second lead screw, the second nut being configured to move the carriage in the second direction of movement.

6. The DLP-type 3D printing system according to claim 5, wherein said moving means comprises a third screw drive; the third lead screw drive includes a rotatably mounted third lead screw and a third nut coupled to the third lead screw for translational movement along the third lead screw, the third nut being configured to move the carriage in the printing direction.