TWM510242U - Stereolithography machine with improved optical unit - Google Patents

Abstract

Stereolithography machine (1) comprising: a container (2) for a fluid substance (14); a source (3) of predefined radiation (3a) suited to solidify the fluid substance (14); an optical unit (4) suited to direct the radiation (3a) towards a reference surface (5) in the fluid substance (14); a logic control unit (6) configured to control the optical unit (4) and/or the source (3) so as to expose a predefined portion of the reference surface (5). The optical unit (4) comprises a micro-opto-electro-mechanical system (MOEMS) (7) provided with a mirror (8) associated with actuator means (7a) for the rotation around at least two rotation axes (X, Y) incident on and independent of each other, arranged so that it can direct the radiation (3a) towards each point of the reference surface (5) through a corresponding combination of the rotations around the two axes (X, Y).

Description

Photocuring machine with improved optical unit

The present invention relates to a photocuring molding machine for fabricating three-dimensional articles with an associated superimposed layer, each layer being formed by selectively curing a flowing substance in a region corresponding to the article of manufacture.

Known types of photocuring machines have a flow material container that houses a photosensitive resin, typically a liquid or paste.

This machine also contains a projection source, typically a type of illumination that emits light suitable for curing the flowing material.

The optical unit is configured to pass the radiation to a reference surface disposed in the container corresponding to the position of the layer of the article to be cured.

The formed three-dimensional object is supported by the module board and is vertically movable relative to the container for arranging the newly formed cured layer of the article adjacent to the reference surface.

Thus, once each layer is cured, the module board is moved to again lay the formed solidified layer adjacent the reference surface and the process is repeated for the finished layer.

This type of photocuring machine can be divided into two main examples. For example, the same applicant's Italian patent application number VI2010A000004.

According to a first example of the foregoing example, the datum is placed adjacent to the bottom of the container, which is transparent for projection.

In this example, the flowing material is irradiated from below, and the three-dimensional object is formed under the module board.

According to a second example, the reference plane is placed at the level of the free surface of the flowing material.

In the second example, the flowing material is irradiated from above, and the three-dimensional object is formed above the module board.

In both examples, various known optical units can be utilized to deliver different points of projection to the reference plane. The first type of optical unit includes a mirror array that can be individually controlled to project an image of the layer of the object to a predetermined surface.

In particular, each mirror can be set to two different positions, one is the active position, the projection is reflected to the corresponding position of the reference surface, and the other is the passive position, and the projection is reflected to the dispersion area.

The mirror array can simultaneously illuminate the entire reference plane, so that each layer can be formed in a single projection manner, which is a particularly fast manner. Of course The mirror array has its limitations, which is inconvenient when forming irregular edge objects.

A further disadvantage of the aforementioned system is that the image produced by it produces an uneven illumination intensity across the entire surface. Therefore, the defect of the system is that the light intensity cannot be adjusted in different areas of the reference plane.

In the second type of optical unit, the projection system is transmitted to a single point of the reference plane, and the single point is moved to gradually illuminate the entire portion of the reference plane of the corresponding object volume.

Compared with the optical unit of the front opening type, the optical unit of the present invention has the advantage that it can guide the light beam to any point of the reference surface so as to cover continuous projection, and can form an object and avoid the type of optical unit as described above. mistake.

Furthermore, such optical units have the advantage of being able to adjust the light intensity in different areas of the reference plane.

According to the optical unit of the second type, the laser projection source is moved along the two orthogonal axes by the mechanical element.

A disadvantage of this example, however, is that the beam moves slower and the mechanical components used to move the beam are at risk of failure and require considerable maintenance.

According to an example of a different optical unit, a galvanometer mirror with a fixed projection source and a pair of serially arranged mirrors is used to guide the light beam.

Each of the mirrors is mechanically controlled to rotate about a mutually orthogonal axis of rotation, and by means of a combination of the respective axes of rotation, the beam can be directed to any point of the reference plane.

Compared with the prior art system, the system of this example has the advantage that the galvanometer mirror can move the beam quickly due to the small inertia of the mirror, and the reliability is ensured by the use of fewer mechanical components.

Even with the advantages of the foregoing, when constructing the machine, the optical unit still needs to be aligned with the two mirrors in order to obtain the correct reflection of the beam.

In fact, in order to obtain the direction of the beam corresponding to the position of the mirror, it is necessary to have the beam incident on the two mirrors at the level of each axis of rotation.

A disadvantage of the front opening alignment operation is that it is very complicated and increases the cost of the photocuring machine.

In use, if one or two mirrors are damaged, the potential will need to be replaced and correctly aligned again, which also causes the aforementioned disadvantages.

Another disadvantage is that the galvanometer mirrors are quite expensive and significantly dictate the cost of the photocuring machine.

Another disadvantage of optical units using galvanic mirrors is that they are cumbersome. The high cost and size make it impossible to apply to the small series of products required for small process organizations.

Furthermore, galvanometer mirrors must be equipped with certain mechanical components, so there is no advantage over the aforementioned mechanical mobile machines.

And because of the inertia that the galvano mirror can't ignore, it also affects the beam's offset speed and overall manufacturing time.

This creation is intended to overcome all of the disadvantages mentioned in the aforementioned prior art types.

In particular, the purpose of this creation is to provide a photocuring molding machine having all the advantages of a photocuring molding machine of the type mainly composed of an ammeter mirror, but which is simpler to manufacture and use.

In particular, another object of the present invention is to provide a photocuring molding machine that does not require the alignment operation of the aforementioned mirrors, whether in manufacture or in use.

The above object can be achieved for a photocuring molding machine corresponding to the main request range. More detailed features of this creation are found in the scope of each of the affiliated patent applications.

Advantageously, there is no need to align the mirrors, ie, the footer items are of a more conventional type, which considerably simplifies the architecture of the present photocuring machine and achieves lower cost.

It will be appreciated that the replacement of the optical unit during use still exists, thereby reducing the maintenance cost of the machine.

Moreover, the photocuring machine of the present invention has a smaller overall size than the overall size of the machine type having the same capabilities.

The two advantages mentioned in the previous opening are more conducive to the solidification of the light of the creation. The machine is applied to small series of products that are not suitable for conventional types.

1‧‧‧Light Curing Machine

2‧‧‧ Container

2a‧‧‧ bottom

3‧‧‧Projection source

3a‧‧‧Predefined projection

4‧‧‧ Optical unit

5‧‧‧ datum

6‧‧‧Logical Control Unit

7‧‧‧Micro-optical electromechanical systems (MOEMS)

7a‧‧‧Actuating element

7b‧‧‧Connecting components

8‧‧‧Mirror

9‧‧‧Support structure

10‧‧‧ bracket

11‧‧‧First connection area

12‧‧‧Second connection area

13‧‧‧ lens

14‧‧‧Mobile substances

15‧‧‧Three-dimensional objects

16‧‧‧Modular board

X, Y‧‧‧ first and second axis of rotation

Z‧‧‧ vertical movement axis

These objects and advantages, as well as others which will be shown hereinafter, will be apparent from the following description of the embodiments of the non-limiting examples, and in the accompanying drawings.

Figure 1 shows a photocuring machine according to the present invention.

Fig. 2 is a view showing a detail of the photocuring molding machine in Fig. 1.

The photocuring machine of the present invention is designated as 1 in Figure 1, which is capable of fabricating a three-dimensional object 15 by a plurality of mutually superposed layers, the formation of which is formed by a predefined projection 3a. Substance 14 is exposed to cure.

Preferably, the flowing substance 14 is a photosensitive resin, and the predefined projection 3a is laser light having a frequency in the visible or ultraviolet range.

Obviously, in a variation of the present creation, the flow material 14 can be any liquid or paste suitable for curing when exposed to a predefined projection 3a.

Similarly, the projection source 3 of the projection 3a can also project a projection 3a different from the front opening type, and only the flowing substance 14 can be cured.

The photocuring molding machine 1 comprises a container 2 for accommodating the flowing substance 14 and the module board 16, and is adapted to support the object 15 formed by the vertical movement axis Z.

The machine 1 further comprises a projection source 3 adapted to project a predefined projection 3a, the optical unit 4 being adapted to guide the projection 3a to any point of the reference surface 5 disposed in the container 2 at the level of the volume of the flowing substance 14.

Preferably, the reference surface is a flat surface and is disposed adjacent to the bottom 2a of the container 2.

In this case, the optical unit 4 is used to guide the predefined projection 3a from the bottom up to be incident on the bottom 2a.

Also, the bottom portion 2a is transparent to the projection 3a so that the projection (3a) can hit the flowing substance 14 disposed near the bottom to solidify it.

According to this embodiment of the present creation, a three-dimensional object 15 can be formed under the module board 16 as shown in FIG.

According to this variation, which is disclosed herein, the optical unit is used to guide the projection 3a from the top to the bottom to the free surface of the flowing substance 14 in the container 2.

In this case, the object is formed on the module board 16.

In the two variants mentioned above, the photocuring machine 1 comprises a logic control unit 6 for controlling the optical unit 4 and/or the projection source 3 such that the projection 3a selectively pairs the flowing substance 14 with the reference surface. The level of the predefined portion is exposed.

Furthermore, in particular, the predefined portion of the corresponding partial volume corresponds to each layer of the three-dimensional object 15 at all times.

According to the present invention, the optical unit 4 comprises a micro-optical electromechanical system 7 using integrated circuit technology, abbreviated as MOEMS.

As is well known, MOEMS components are integrated circuits fabricated by the same techniques as in microelectromechanics, such as by solid phase deposition, lithography, etching, and the like.

One of the micro-optical electromechanical systems 7 may be an embodiment, but not limited to FIG. 2, comprising a miniaturized mirror 8 connected to the support structure 9 by a connecting element 7b for defining a relative structure for the mirror 8 The first and second axes of rotation X, Y, which are different from each other, are incident on each other and are preferably orthogonal to each other.

The micro-optical electromechanical system 7 can also comprise an actuating element 7a which is essentially known to be adapted to move the mirror 8 independently about the first and second axes of rotation X, Y, respectively.

The actuating element 7a can be of the electric, magnetic, thermomechanical or other known type that can be obtained by the MOEMS means.

The mirror 8 is disposed relative to the projection source 3 and the container 2, and is capable of reflecting the predefined projection 3a by guiding the predefined projection 3a to the reference by a corresponding combination of the first and second rotation axes X, Y. Any point of the face.

Therefore, the present invention can guide the projection 3a to any point of the reference plane by using a single mirror 8.

Therefore, it is not necessary to align the plurality of mirrors with each other as described in the prior art, so that the purpose of simplifying the manufacture of the photocuring machine 1 can be achieved, and the cost can be reduced.

Obviously, even if the whole or part of the micro-optical electromechanical system 7 is replaced in use, the advantages still exist, so that the maintenance cost of the machine 1 can be reduced.

It is still advantageous that the aforementioned micro-optical electromechanical system 7 does not require high precision angular positioning during assembly.

In fact, any slight angular change in the configuration of the micro-optical electromechanical system 7 involves only the movement of the reference surface relative to the container 2, but the shape of the exposed reference surface and the predefined portion does not undergo a substantial degree of deformation.

It is still advantageous that the micro-optical electromechanical system 7 has a lower cost than the galvano mirror-based system, and can further reduce the cost of the photo-curing molding machine 1.

Moreover, advantageously, the micro-optical electromechanical system 7 has a smaller inertia than a galvanometer mirror, enabling it to achieve a faster angular velocity, while producing the same shape as a conventional type of photocuring machine. When the object is used, the time required to manufacture the three-dimensional object 15 can be reduced.

It is still advantageous that the micro-optical electromechanical system 7 has a smaller overall size than the overall size of the optical unit of the galvanometer mirror having the same capability, and can reduce the overall size of the photo-curing machine 1.

Therefore, due to cost reduction and overall size reduction, the present invention can provide a photocuring molding machine 1 which is not applicable to a conventional type of photocuring molding machine.

More advantageously, the micro-optical electromechanical system 7 of the present invention absorbs less energy than a conventional type of photocuring machine having considerable capabilities.

Reducing the energy consumption plus considerable miniaturization enables the photocuring machine 1 to be battery powered and possibly carryable.

It will be further appreciated that the photocuring machine 1 as described above has all of the advantages of using an galvanometer mirror for the optical unit, particularly with the same accuracy and adjustable power of the projection 3a for different regions of the object 15.

Preferably, as shown in FIG. 2, the connecting member 7b includes a movable bracket 10 that rotatably supports the mirror 8 about the first axis of rotation X and is rotatably coupled to the support structure 9 about the second axis of rotation Y.

This connection allows the mirror 8 to be independently rotatable about the first and second axes of rotation X, Y mentioned above.

Moreover, preferably, the mirror 8, the bracket 10 and the supporting structure 9 are integrally formed, and the first connecting portion 11 and the second connecting portion 12 of the connecting member 7b are connected to each other, and are thin enough to respectively surround the first, The second axis of rotation X, Y is elastically flexed to rotate the mirror 8 relative to the bracket 10, and the bracket 10 is rotated relative to the support structure 9.

It is worth mentioning that the first connection area 11 and the second connection area 12 can respectively be deformed to a certain extent like a torsion spring according to the standard voltage of the device.

Obviously, in the variation example of the present creation, the micro-optical electromechanical system 7 can be of any shape, and only the mirror 8 can be rotated independently of each other and incident on both axes.

Regarding the actuating element 7a, the mirror 8 is moved, preferably for rotating the mirror 8 around the first and second axes of rotation X, Y according to the control signal set by the logic control unit 6 having a value representative of the angular position. .

It is worth mentioning that the logic control unit 6 is used to move the mirror 8 such that the projection 3a can fall within a predefined portion of the layer of the corresponding object 15 to produce at least one continuous projection as described below.

Preferably, but not necessarily, the movement is based on a single continuous projection covering the entire predefined portion.

According to a variation example of the present creation, the micro-optical electromechanical system 7 and the corresponding actuating element 7a are used to generate a ring motion of the mirror 8 so that the projection 3a can gradually stimulate the entire reference surface 5 in each cycle. .

For example, the ring motion may comprise oscillation of the mirror 8 in accordance with one of the first and second axes of rotation X, Y, or both directions of rotation. Preferably, it is obtained by using the resonance frequency of each connection zone 11 or 12 in combination with the rotation of another axis which is based on a single direction.

Thereby, the projection 3a is incident on the reference plane 5 and projected in a zigzag shape, each of which is traversed by the reference plane 5 in one dimension while moving according to another dimension.

In this last variation, the logic control unit 6 is adapted to vary the intensity of the projection source 3 during the ring motion of the mirror 8.

It is worth mentioning that when the incident point is within a predefined portion of the reference plane 5, the intensity of the projection source 3 increases to solidify the flow material 14 at that point, When the point of incidence is outside the predefined portion, the intensity is reduced to avoid solidifying the corresponding portion of the flowing material 14.

The micro-optical electromechanical system 7 as described above preferably belongs to an integrated circuit having an electrical connection pin for the machine 1, the machine 1 having a corresponding connector or base for arranging the pins for the mechanism The integrated circuit is fixed to the machine 1.

Preferably, the connector or base is of the type that requires only a limited force for its insertion.

In this variation of the creation, the micro-optical electromechanical system 7 can be soldered directly to the supporting electronic circuit to avoid the use of connectors or pedestals.

With regard to the optical unit 4, at least one lens 13 is preferably included for focusing the projection 3a on the reference plane 5.

Preferably, the lens 13 is a so-called flat field lens to focus the projection 3a on a flat reference plane.

From the operational point of view, the micro-optical electromechanical system 7 is disposed inside the photo-curing machine 1 to align the projection 3a produced by the projection source 3 with the mirror 8.

Preferably, the position of the projection source 3 and the micro-optical electromechanical system 7 is such that when the mirror 8 is in an unrotated state, that is, the connection regions 11, 12 are not twisted, the projection 3a is reflected to the center point of the reference surface 5.

However, as mentioned earlier, any slight angular misalignment of the micro-optical electromechanical system 7 does not affect the function of the machine 1.

Regarding the fabrication of the solid three-dimensional object 15, as is known in the art, the programming is similar to an optical unit having a galvanometer mirror.

As previously stated, it should be understood that the present photocuring machine achieves all of the foregoing objectives.

It is worth mentioning that the galvanometer mirror is replaced by a micro-optical electromechanical system (MOEMS), so that only a single mirror can be used to move on two independent axes instead of two mirrors moving on a single axis.

A single mirror avoids the need for complex mirror alignment for machines that use galvanometer mirrors.

Furthermore, compared to galvanometer systems, micro-optical electromechanical systems are economical, not bulky, and consume less energy. Therefore, it can be made more suitable for small series products, even portable types.

Other variations of the present invention, although not illustrated in the drawings and not shown in the drawings, are still considered to be protected by the present patent as long as they fall within the scope of the following patent application. In the case of the technical features mentioned in the patent application, if the reference numerals are attached, the purpose of adding the reference numerals is only for the readability of the patent application scope, and therefore the reference numerals should not be The protection of the elements indicated by these reference numerals imposes any limitation.

1‧‧‧Light Curing Machine

2‧‧‧ Container

2a‧‧‧ bottom

3‧‧‧Projection source

3a‧‧‧Predefined projection

4‧‧‧ Optical unit

5‧‧‧ datum

6‧‧‧Logical Control Unit

7‧‧‧Micro-optical electromechanical systems (MOEMS)

7a‧‧‧Actuating element

8‧‧‧Mirror

9‧‧‧Support structure

10‧‧‧ bracket

13‧‧‧ lens

14‧‧‧Mobile substances

15‧‧‧Three-dimensional objects

16‧‧‧Modular board

X, Y‧‧‧ rotating shaft

Z‧‧‧ vertical movement axis

Claims (10)

A photocuring molding machine (1) comprising: a container (2) for accommodating a flowing substance (14) suitable for curing by exposure to a predefined projection (3a); a projection source of a predefined projection (3a) (3) an optical unit (4) adapted to selectively guide the projection (3a) to any point of a reference plane (5) disposed in the container (2); a logic control unit (6) for Controlling the optical unit (4) and/or the projection source (3) such that the projection (3a) exposes a predefined portion of the reference plane (5), characterized in that the optical unit (4) comprises micro An electromechanical system (MOEMS) (7) having a mirror (8) connected to the support structure (9) by a connecting element (7b) for defining at least a first and a second axis of rotation for the mirror (8) (X, Y) are incident on each other; the actuating element (7a) is adapted to independently move the mirror (8) around the first and second axes of rotation (X, Y), the mirror (8) being relatively projected The source (3) and the container (2) are disposed to guide the projection (3a) to any one of the reference planes (5) by a corresponding combination of the first and second rotation axes (X, Y) . The photocuring molding machine (1) according to claim 1, wherein the first and second rotation axes (X, Y) are orthogonal to each other. The photocuring molding machine (1) according to claim 1, wherein the connecting member (7b) comprises a bracket (10) rotatably supporting the mirror about the first rotating shaft (X) (8) The bracket (10) is rotatably coupled to the support structure (9) about the second axis of rotation (Y) of the rotating shafts. The photocuring molding machine (1) according to claim 3, characterized in that the connecting element (7b) comprises a first connecting region (11) disposed on the mirror (8) and the bracket (10) Between the first rotation axis (X) elastically flexing, and the second connection region (12), disposed between the bracket (10) and the support structure (9), around the second rotation axis ( Y) elastically flexive. The photocuring molding machine (1) according to claim 1, wherein the actuating member (7a) is configured to independently move the mirror around the first and second rotating axes (X, Y) (8), so that the mirror (8) corresponds to the logic control unit (6), and the control signal having the value representing the angular position is at the angular position. The photocuring molding machine (1) according to claim 5, wherein the logic control unit (6) is configured to move the mirror (8) such that the projection (3a) is on the reference surface The continuous projection of the entry point definition of (5) covers the entire predefined portion of the reference plane (5). The photocuring molding machine (1) according to claim 1, wherein the actuating member (7a) is configured to generate a ring motion of the mirror (8) such that the projection (3a) is Each of the periods can be incident on the entire reference plane (5), and the logic control unit (6) is configured to selectively change the intensity of the projection source (3) so that when the projection (3a) falls on the In the predefined portion of the reference plane (5), the intensity is greater than the intensity when the projection (3a) falls outside the predefined portion of the reference plane (5). The photocuring molding machine (1) according to claim 1, wherein the micro-optical electromechanical system (7) belongs to a device for electrically connecting pins In an integrated circuit, the photocuring machine (1) includes corresponding connecting elements for arranging the pins to mechanically fix the integrated circuit. The photocuring molding machine (1) according to the first aspect of the invention is characterized in that the projection source (3) is a laser emitter. The photocuring machine (1) according to any one of the preceding claims, wherein the optical unit (4) comprises at least one lens (13) for focusing the projection ( 3a) on the reference plane (5).