This application is based upon and claims priority to Chinese Patent Application No. 202221264280.3, filed on May 24, 2022, the entire contents of which are incorporated herein by reference.
The present disclosure relates to the technical field of 3D printing, and in particular to a 3D printer, and a light source of the 3D printer.
In a photo-curing 3D printer, a resin vat containing a resin is placed on a display screen of the 3D printer, a light source is located on the side of the display screen away from the resin vat, a light beam of the light source is projected into the display screen, projected light cover the whole display region of the display screen, and the light is then projected into the resin in the resin vat through a pattern on the display screen, so that the resin is cured layer by layer according to a pre-set pattern.
The uniformity of the projected light directly affects the curing of the resin. The uniform light make all resin uniformly cured, which is conductive to improving the printing precision and avoiding failed demolding. However, since the light propagate in the form of a light beam, light in different regions of the light beam have different densities, resulting in non-uniform projected light and thus affecting the effect of curing the resin.
In view of this, the present disclosure provides a light source of a 3D printer and a 3D printer, which adjust propagation angles of light mainly by configuring surface profiles of an incident surface and an emergent surface of a light adjusting element, so that the light can be uniformly projected into a display screen to facilitate uniform curing of a resin.
In order to achieve the above object, the present disclosure mainly provides the following technical solutions.
In an aspect, the present disclosure provides a light source of a 3D printer, including:
The second surface includes a first region and a second region that are adjacent to each other, where the first region is a planar surface, the second region circumferentially surrounds the first region, and the first region is closer to the vertex of the first surface than the second region;
The second region has a surface profile selected from one or a combination of a spherical surface, an aspherical surface and a conical surface.
The second region includes a first sub-region, a second sub-region and a third sub-region that are successively adjacent to one another, where the first sub-region circumferentially surrounds the first region, the second sub-region surrounds the first sub-region, and the third sub-region circumferentially surrounds the second sub-region; the second sub-region has a conical surface; and
The light adjusting element further includes a third surface, a fourth surface and a side vertical surface, where
A perpendicular distance e between the vertex of the first surface and the fourth surface is greater than or equal to 5 mm and less than or equal to 100 mm; and/or
The light source body comprises a fixing base plate and a light emitting element, the light emitting element being arranged on the fixing base plate, the fixing base plate and the second surface together defining an accommodating cavity, and the light emitting element being located in the accommodating cavity.
The light source body further includes a protective cover; and
A distance b between the vertex of the first surface and the vertex of the light source body is greater than or equal to 5 mm and less than or equal to 100 mm; and/or
At least one of the first surface and the second surface is an aspherical surface, and the aspherical surface meets the following formula:
cx represents a curvature of the vertex of the aspherical surface in an x direction, Rx represents a radius of curvature of the vertex of the aspherical surface in the x direction, cy represents a curvature of the vertex of the aspherical surface in a y direction, Ry represents a radius of curvature of the vertex of the aspherical surface in the y direction, kx represents an aspheric coefficient in the x direction, ky represents an aspheric coefficient in the y direction, A2n and B2n both represent higher-order coefficients of the aspherical surface or correction coefficients of the aspherical surface, and n represents a positive integer greater than 1.
The second surface is an arc-shaped surface, the second surface has a radius of curvature R0 greater than or equal to 5e, e representing a perpendicular distance between the vertex of the first surface and a plane where an edge of the second surface is located.
The light source body includes the fixing base plate and the light emitting element, where the light emitting element is arranged on the fixing base plate; and
The light emitting element is the surface light source, the surface light source including a plurality of light emitting chips, and the distance between two adjacent light emitting chips being less than or equal to 3 mm.
The light emitted by the light source body is uniformly projected after refracted by the light adjusting element.
In another aspect, the present disclosure further provides a 3D printer, including: a light source of a 3D printer of any one of the foregoing embodiments, and
The gate has an outer display diameter δ, and a perpendicular distance a between the vertex of the first surface and the gate is greater than or equal to 0.2δ and less than or equal to 5δ.
The light source of the 3D printer and the 3D printer provided by the present disclosure adjust the propagation angles of light mainly by configuring the surface profiles of the incident surface and the emergent surface of the light adjusting element, so that the light can be uniformly projected into the display screen to facilitate uniform curing of the resin. In the prior art, since light propagate in the form of a light beam, light in different regions of the light beam have different densities, resulting in non-uniform projected light and thus affecting the effect of curing the resin. Compared with the prior art, in the document of the present application, the incident surface of the light adjusting element is configured as the concave surface, the emergent surface of the light adjusting element is configured as the convex surface, and the light emitted by the light source body are refracted twice though the concave surface and the convex surface to change the propagation angles of the light rays, so as to provide the effect of converging the light in the sparse region, so that the refracted light is uniformly projected into the display screen.
In order to further illustrate the technical means adopted to achieve the intended purpose of the present disclosure and the technical effects of the present invention, the specific implementations, structure and features of a light source of a 3D printer disclosed in the present disclosure and the effects thereof are described in detail below in conjunction with the accompanying drawings and the preferred embodiments, as detailed below. For ease of description, light emitted by the light source will be described in the form of light rays.
In an aspect, as shown in
In an embodiment, the 3D printer includes a base box. The base box is of a cavity structure, a gate 300 is provided on the base box, the light source is located in the base box, and a resin vat is provided on the side of the gate 300 away from the light source. Slicing data of a printing model is transmitted to the gate 300 one by one by a master controller, the gate 300 allows light of a specific contour to pass through, and the light emitted by the light source is projected into the gate 300, pass through the gate 300, and are then projected into a resin in the resin vat in the form of the specific contour, so that the resin is cured according to the specific contour. For ease of description, as an example, the gate 300 is located at a top end of the base box, and the light from the light source are projected from bottom to top. In addition, it is also possible that the gate 300 is located at a bottom end of the base box body, and the light from the light source are projected from top to bottom. In some embodiments, the gate 300 can be a display screen. Light can be projected into the display screen and passed through the display screen.
The light source body 100 can be in various forms, such as a chip on board (COB) light source, an integrated light source, a laser light source or a mercury lamp. The light source body 100 includes a light emitting element 120 and a fixing base plate 110. The light emitting element 120 can be a point light source or a surface light source including a plurality of light emitting chips, where a distance between two adjacent light emitting chips is less than a threshold, such as a threshold of 3 mm, and the light emitting element 120 is an integrated light source or a COB light source with a maximum distance between the light emitting chips being less than or equal to 3 mm. In this embodiment, as an example, the light emitting element 120 is the point light source or the surface light source with a very small distance between the light emitting chips, for example, the light source body 100 emits light by means of a UV lamp bead or a plurality of light emitting chips with a very small distance therebetween. The light adjusting element 200 is arranged on a light-ray propagation side of the light source body 100, the point light source or a central light emitting chip of the surface light source is located on an optical axis of the light adjusting element 200, or a perpendicular distance between the point light source or the central light emitting chip of the surface light source and the optical axis is less than a distance threshold, and the distance threshold can be 10 mm, ensuring that the light is uniformly adjusted.
The light is refracted through the light adjusting element 200, so that propagation angles of the light is changed, and propagation directions of the light can be adjusted by changing surface profiles of the first surface 210 and the second surface 220 to change refraction angles of the light in different regions, so as to adjust the uniformity of the light projected into a display screen. The light from the light source body 100 propagate outwardly from a light emitting point in the form of a conical light beam. For ease of description below, the first surface 210 of the light adjusting element 200 is referred to as an emergent surface, the second surface 220 is referred to as an incident surface, the light projected into the incident surface are referred to as incident light rays, the light emerging from the emergent surface is referred to as refracted light rays, and the refracted light is projected light projected into the display screen.
The emergent surface is a convex surface, specifically an arc-shaped surface, the incident surface is a concave surface that is recessed towards the emergent surface, and there is a transparent light propagation medium with a light propagation speed different from the speed in the air between the incident surface and the emergent surface. When the light enters the light adjusting element 200 from the incident surface, a first refraction occurs, and the propagation directions of the light is changed for the first time, and when the light emerges from the light adjusting element, a second refraction occurs at the emergent surface, and the propagation directions of the light is changed for the second time. Since the incident surface is the concave surface and the emergent surface is the convex surface, the two refractions of the light are both offset in the same direction to provide the effect of converging the light rays. Thus, densification adjustment of the light in a sparse region is implemented, so that the light is uniform. For example, in an embodiment, the light emitted by the light emitting element 120 is gradually sparse from a central light ray towards an edge of a light beam, and in order to avoid the situation in which the light projected into the display screen gradually weakens from the center to the outside, the light adjusting element 200 is arranged on the light-ray propagation side of the light emitting element 120, and the specific surface profiles of the incident surface and the emergent surface are configured so as to enhance change in angle of the light ray close to the edge of the light beam. As shown in
It will be appreciated that the refracted light in this embodiment includes light propagating at multiple angles, for example, the refracted light still propagates in the form of an approximate light beam, the degrees of uniformity of the light at different positions in the light beam are different due to different propagation directions of the light rays, and a position where the light in the refracted light beam are the most uniform can be found by adjusting the distance between the light source body 100 and the gate 300, which will be described in detail below.
The light source of the 3D printer and the 3D printer provided by the embodiments of the present disclosure adjust the propagation angles of light mainly by configuring the surface profiles of the incident surface and the emergent surface of the light adjusting element, so that the light can be uniformly projected into the display screen to facilitate uniform curing of the resin. In the prior art, since light propagates in the form of a light beam, light in different regions of the light beam has different densities, resulting in non-uniform projected light and thus affecting the effect of curing the resin. Compared with the prior art, in the document of the present application, the incident surface of the light adjusting element is configured as the concave surface, the emergent surface of the light adjusting element is configured as the convex surface, and the light emitted by the light source body is refracted twice though the concave surface and the convex surface to change the propagation angles of the light rays, so as to provide the effect of converging the light in the sparse region, so that the refracted light is uniformly projected into the display screen.
The surface profiles of the first surface 210 and the second surface 220 can be in various forms, and incident angles of the light is adjusted by adjusting the surface profiles of the first surface 210 and the second surface 220, so as to adjust the propagation angles of the refracted light rays, so that the effect of uniformizing the light is achieved. The surface profiles of the first surface 210 and the second surface 220 are related to the arrangement position of the light source body, the type of the light emitting element and the distance between the light source and the display screen, for example, the first surface 210 can be a continuous arc-shaped surface, and the second surface 220 can be a continuous arc-shaped surface or multiple surface profiles connected to each other. In this embodiment, several specific surface profiles are provided.
In an embodiment, as shown in
The first region 221 is a planar surface, the second region 222 is an annular region with a uniform width, and the second region 222 extends from an edge of the first region 221 in a direction away from the optical axis of the light adjusting element 200 and away from the vertex of the first surface 210, so that the first region 221 and the second region 222 together define a groove having an opening contour that is the same as an outer contour of the first region 221 in shape, and having an opening area greater than the area of the first region 221. The second region 222 cooperate with the first surface 210 to provide a strong effect of converging the light rays, so that the light close to an edge region of the light beam is densified. The second region 222 is not limited to one surface profile, and flexible adjustment of the angles of the light incident from the second region 222 can be achieved by adjusting the surface profile of the second region 222 to adapt to light beams of different densities, for example, the second region 222 can have a surface profile selected from one or a combination of a spherical surface, an aspherical surface and a conical surface.
For example, the second region 222 includes a first sub-region 223, a second sub-region 224 and a third sub-region 225 that are successively adjacent to one another. The first sub-region 223 circumferentially surrounds the first region 221, the second sub-region 224 circumferentially surrounds the first sub-region 223, and the third sub-region 225 circumferentially surrounds the second sub-region 224.
In an embodiment, the first sub-region 223 and the third sub-region 225 each have an arc-shaped surface, and the second sub-region 224 has a conical surface. On the one hand, it is convenient to machine the first sub-region 223 and the third sub-region 225, and on the other hand, smooth transition is achieved at a connection position between the first region 221 and the second sub-region 224, and the part of the second sub-region 224 close to an opening of the recess, without an abrupt change in the density of the light rays, and the phenomenon of an annular dark region in a projection is thus avoided.
The first sub-region 223 and the third sub-region 225 can have spherical or aspherical surfaces, for example, ellipsoidal surfaces, and the angles of the light can also be flexibly adjusted by adjusting an aspheric coefficient.
In some other embodiments, as shown in
The aspherical surface refers to an arc-shaped surface with inconsistent curvatures at all parts. The curvature changes continuously from the vertex to an edge of the aspherical surface. The surface profile of the aspherical surface can be represented by a higher-order polynomial containing aspheric coefficients, and specifically, the aspherical surface can be of a rotationally symmetrical structure. In some embodiments, the surface profile of the aspherical surface is represented by a polynomial as follows:
cx represents a curvature of the vertex of the aspherical surface in an x direction, Rx represents a radius of curvature of the vertex of the aspherical surface in the x direction, cy represents a curvature of the vertex of the aspherical surface in a y direction, Ry represents a radius of curvature of the vertex of the aspherical surface in the y direction, kx represents an aspheric coefficient in the x direction, and ky represents an aspheric coefficient in the y direction. When kx=ky=0 and Rx=Ry, the arc-shaped surface is a spherical surface, A2n and B2n both represent higher-order coefficients of the aspherical surface or correction coefficients of the aspherical surface, the absolute values of A2n and B2n are in the ranges of 0≤A2n<1, 0≤B2n<1, n=2, 3, 4 . . . , and the accurate values of specific parameters are adjusted according to a corresponding scenario, which will not be described in detail herein.
The surface profile of the aspherical surface can be adjusted by adjusting the radius of curvature Rx in the x direction of the vertex of the aspherical surface, the radius of curvature Ry in the y direction of the vertex of the aspherical surface, the aspheric coefficient kx in the x direction and the aspheric coefficient ky in the y direction, and the effect of homogenizing the light is thus achieved. For example, the light do not abruptly change at the junctions of the surface profiles by adjusting the surface profiles of the first sub-region 223 and the third sub-region 225, and when the second surface 220 is an arc-shaped surface, at least one of the surface profiles of the first surface 210 and the second surface 220 is adjusted, so that the light is uniform.
The radius of curvature is used to describe the degree of curvature of a curved surface, and it can be approximatively understood that the greater the radius of curvature is, the smaller the degree of curvature of the curved surface is. The radius of curvature of the vertex of the aspherical surface is a main parameter determining the imaging of an aspherical optical system, and affects basic properties of the aspherical surface, such as a focal length of the aspherical surface, and the best optical effect of the aspherical surface can be achieved by adjusting the radius of curvature of the vertex of the aspherical surface. In an embodiment, as shown in
In an embodiment, as shown in
The protrusion is used for fixing the light adjusting element 200, and specifically, the light adjusting element 200 can be fixed by means of an annular fixing member pressing against the third surface 230, so as to avoid drilling in the protrusion for connection. The light from the light source 11 includes stray light with a large angle, which enters the protrusion via the second surface 220, and since the third surface 230 of the protrusion is covered with the annular fixing member, the stray light will be blocked to avoid the influence of the stray light on the projected light rays. In addition, in other embodiments, the third surface 230 can also be coated with a light absorption coating, such as a graphite coating for absorbing stray light.
In order to reduce light loss and enhance the universality of the light adjusting element 200, in some embodiments, as shown in
In an embodiment, the light source body 100 includes a fixing base plate 110 and a light emitting element 120. The light emitting element 120 is arranged on the fixing base plate 110, the fixing base plate 110 and the second surface 220 together define an accommodating cavity, and the light emitting element 120 is located in the accommodating cavity.
The light emitting element 120 is located in the accommodating cavity, so as to avoid the influence of the light from the light emitting element 120 on the projected light rays, and the light from the light emitting element 120 is all projected into the gate 300 through a lens assembly 200, so as to ensure the intensity of the projected light.
In an embodiment, the fixing base plate 110 is connected to the fourth surface 240, and the light emitting element 120 is located on the fixing base plate 110 such that the light source is approximately centered in the opening of the recess. In some embodiments, as shown in
In an embodiment, as shown in
In some embodiments, the protective cover 130 includes a cavity having a lower opening, and the protective cover 130 covers the light emitting element 120 from the lower opening and is fixed to the base plate 110 so that the light emitting element 120 is located in the cavity to provide the effect of protecting the light emitting element 120. The material of the protective cover 130 includes acrylic.
It will be appreciated that a tangent plane of the vertex of the light source body 100 is closer to the first surface 210 than the fourth surface 240 so that the light source body 100 is located inside the accommodating cavity. When the second surface 220 includes the planar first region 221, the vertex of the second surface 220 refers to the central point of the first region 221, and the central point of the first region 221 is located on the optical axis of the light adjusting element 200.
It will be appreciated that in the above description of the embodiments, the above-mentioned structural arrangements and distance ranges do not present separately, but mutually restrict to jointly enable the adjustment of the propagation angles of the light rays, so that the projected light shows good uniformity. As shown in
In another aspect, the embodiments of the present disclosure further provide a 3D printer. The 3D printer includes a light source of a 3D printer of any one of the foregoing embodiments, and a gate 300. The gate 300 is used for displaying a pattern of a specific contour. The light source of the 3D printer is arranged on a first side of the gate 300, and light emitted by the light source of the 3D printer is projected into the gate 300 and pass through the gate 300 to cure a resin.
In an embodiment, the gate 300 has an outer display diameter δ, and a perpendicular distance a between the vertex of the first surface 210 and the gate 300 is greater than or equal to 0.2×δ and less than or equal to 5×δ.
The outer display diameter δ is the diameter of a circumscribed circle of a display region of the gate 300. The specific value of the distance a is related to the size of the light adjusting element 200 and the position of the light source body 100 relative to the light adjusting element. The distance between the light source body 100 and the light adjusting element 200 and the gate 300 is adjusted to observe or evaluate the uniformity of the projected light by using a radiant illuminance measuring instrument, so as to find a position where the projection uniformity is the best. In this embodiment, on the basis of the above ranges of the distances, the perpendicular distance a between the vertex of the first surface 210 and the gate 300 is set to be greater than or equal to 0.2δ and less than or equal to 5δ in order to ensure that the projected light has a sufficient projection area to cover the display region and to avoid light loss caused by the light source body 100 being too far away from the gate 300.
In an aspect, the present disclosure provides the following embodiments.
Embodiment 1: A light source of a 3D printer, including:
Embodiment 2: The light source of the 3D printer according to term 1, where the second surface 220 includes a first region 221 and a second region 222, and where the first region 221 is a planar surface, the second region 222 circumferentially surrounds the first region 221, and the first region 221 is closer to the vertex of the first surface 210 than the second region 222;
Embodiment 3: The light source of the 3D printer according to term 2, where the second region 222 has a surface profile selected from one or a combination of a spherical surface, an aspherical surface and a conical surface.
Embodiment 4: The light source of the 3D printer according to term 2, where the second region 222 includes a first sub-region 223, a second sub-region 224 and a third sub-region 225, and where the first sub-region 223 circumferentially surrounds the first region 221, the second sub-region 224 circumferentially surrounds the first sub-region 223, and the third sub-region 225 circumferentially surrounds the second sub-region 224;
Embodiment 5: The light source of the 3D printer according to term 1, where the light adjusting element 200 further includes a third surface 230, a fourth surface 240 and a side vertical surface 250, and where
Embodiment 6: The light source of the 3D printer according to term 5, where a perpendicular distance e between the vertex of the first surface 210 and the fourth surface 240 is greater than or equal to 5 mm and less than or equal to 100 mm; and/or
Embodiment 7: The light source of the 3D printer according to term 5, where a perpendicular distance d between the vertex of the light source body 100 and the fourth surface 240 is greater than or equal to 0 and less than c, and a tangent plane of the vertex of the light source body 100 is closer to the first surface 210 than the fourth surface 240, c representing a distance between the vertex of the second surface 220 and the vertex of the light source body 100.
Embodiment 8: The light source of the 3D printer according to term 1, where the light source body 100 includes a fixing base plate 110 and a light emitting element 120, the light emitting element 120 being arranged on the fixing base plate 110, the fixing base plate 110 being connected to the fourth surface 240, the fixing base plate 110 and the second surface 220 together defining an accommodating cavity, and the light emitting element 120 being located in the accommodating cavity.
Embodiment 9: The light source of the 3D printer according to Embodiment 1, where the light source body 100 further includes a protective cover 130, and where the protective cover 130 is arranged outside the light emitting element 120 and is connected to the base plate 110, and the protective cover 130 is used for protecting the light emitting element 120.
Embodiment 10: The light source of the 3D printer according to embodiment 1, where a distance b between the vertex of the first surface 210 and the vertex of the light source body 100 is greater than or equal to 5 mm and less than or equal to 100 mm; and/or
Embodiment 11: The light source of the 3D printer according to embodiment 1, where at least one of the first surface 210 and the second surface 220 is an aspherical surface, and the aspherical surface meets the following formula:
cx represents a curvature of the vertex of the aspherical surface in an x direction, Rx represents a radius of curvature of the vertex of the aspherical surface in the x direction, cy represents a curvature of the vertex of the aspherical surface in a y direction, Ry represents a radius of curvature of the vertex of the aspherical surface in the y direction, kx represents an aspheric coefficient in the x direction, ky represents an aspheric coefficient in the y direction, A2n and B2n both represent higher-order coefficients of the aspherical surface or correction coefficients of the aspherical surface, and n represents a positive integer greater than 1.
Embodiment 12: The light source for the 3D printer according to embodiment 1, where the second surface 220 is an arc-shaped surface, the second surface 220 has a radius of curvature R0 greater than or equal to 5e, e representing a perpendicular distance between the vertex of the first surface 210 and a plane where an edge of the second surface 220 is located.
Embodiment 13: The light source of the 3D printer according to embodiment 1, where the light source body 100 includes a fixing base plate 110 and a light emitting element 120, and where the light emitting element 120 is arranged on the fixing base plate 110; and
Embodiment 14: The light source of the 3D printer according to embodiment 1, where the light emitting element 120 is a surface light source, the surface light source including a plurality of light emitting chips, and a distance between two adjacent light emitting chips being less than or equal to 3 mm.
Embodiment 15: The light source of the 3D printer according to embodiment 1, where the light emitted by the light source body 100 is uniformly projected after refracted by the light adjusting element 200.
In another aspect, the present disclosure provides the following embodiment 16.
Embodiment 16: A 3D printer, including a light source of a 3D printer of any one of embodiments 1-15, and
Embodiment 17: The 3D printer according to embodiment 16, where the gate 300 has a outer display diameter δ, and a perpendicular distance a between the vertex of the first surface 210 and the gate 300 is greater than or equal to 0.2δ and less than or equal to 5δ.
The foregoing description merely relates to specific embodiments of the present invention, but the scope of protection of the present disclosure is not limited thereto. Changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present disclosure shall fall within the scope of protection of the present invention. Therefore, the scope of protection of the present disclosure shall be subject to the scope of protection of the claims.
Number | Date | Country | Kind |
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202221264280.3 | May 2022 | CN | national |