A laser beam combining and collimating device, a light-curing 3D printing device and a projector

Abstract

The application discloses a laser beam combining and collimating device, which comprises a plurality of single-tube LD lasers, a plurality of collimating lenses, a plurality of reflecting mirrors and a fast-axis amplification collimating cylindrical lens group. The plurality of collimating lenses make each laser beam form an elliptical spot with a fast-axis direction as a long axis and a slow-axis direction as a short axis. Each reflecting mirror is arranged in a staggered manner so that each laser beam is arranged in a staggered manner along the slow-axis direction and the arrangement gap is smaller than that of each single-tube LD laser, and thus the spots of the laser beams together form a rectangular spot with a long side along the slow-axis direction and a short side along the fast-axis direction. The fast-axis amplification collimating cylindrical lens group reshapes the rectangular spot into a square-like or square spot with an unchanged long side along the slow-axis direction and an amplified short side along the fast-axis direction. In the field of light-curing 3D printing and projector illumination light sources, when a polarization type pattern modulation device is used to modulate a pattern, the device can provide a light source with large power, good polarization, good collimation and good spot shape.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of illumination light source technology of light-curing 3D (three-dimensional) printing and projector, in particular to a laser beam combining and collimating device, a light-curing 3D printing device and a projector. BACKGROUND

[0002] In the field of light-curing 3D printing and projector, if the polarization modulation method of projection pattern is used, the illumination light source needs to pass through a polarization beam splitter first to become polarized light before being modulated by a face modulation chip to form a pattern. The natural polarized light will be filtered out by half of the power by the polarization beam splitter, resulting in energy loss. For example, the LED light source commonly used in DLP (Digital Light Processing) projectors is a non-polarized light source. When the light emitted by the LED light source passes through a polarization beam splitter, half of the light power will be lost, thereby reducing the energy utilization rate of the light source. The light emitted by an LD (Laser Diode) laser is linearly polarized light. As long as the angle of the LD laser is adjusted, the light source energy can be close to 100% transmitted through the polarization beam splitter, and a modulating device for controlling the polarization direction is used for pattern modulation.

[0003] However, the power of a conventional ultraviolet LD laser is small, which is insufficient to meet the needs of light-curing 3D printing and other 3D printing methods for light power. Moreover, the collimation of the existing LD laser beam combining is poor, and the spot shape is not good. For a conventional fiber-coupled light source, the LD laser is coupled into an optical fiber after spatial beam combining. The polarization of the polarized light will be affected when the light propagates in the optical fiber. In addition, the beam of the LD laser becomes circular after passing through the optical fiber. For light-curing 3D printing and other applications, the non-ideal spot shape will affect the uniformity of the power distribution. SUMMARY

[0004] The present application aims to solve the technical problems of the existing LD laser, such as small power, poor polarization and collimation, and non-ideal spot shape, and proposes a laser beam combining and collimating device, a light-curing 3D printing device, and a projector.

[0005] The technical problem of the present application is solved by the following technical solution:

[0006] The laser beam combining and collimating device comprises a plurality of single-tube LD lasers, a plurality of collimating lenses, a plurality of mirrors and a fast-axis amplifying and collimating cylindrical lens group, the fast-axis and slow-axis directions of the plurality of single-tube LD lasers are consistent, the plurality of collimating lenses are arranged in one-to-one correspondence in front of the plurality of single-tube LD lasers and are respectively used for simultaneously collimating the laser beams emitted by each single-tube LD laser in the fast-axis direction and the slow-axis direction, so that each laser beam forms an elliptical spot with the fast-axis direction as the long axis and the slow-axis direction as the short axis, each collimated laser beam is reflected by each mirror, each mirror is arranged in a staggered manner so that each laser beam is arranged in a staggered manner along the slow-axis direction and the arrangement gap is smaller than the arrangement gap of each single-tube LD laser, so that the spots of each laser beam together form a rectangular spot with the slow-axis direction as the long side and the fast-axis direction as the short side, and the fast-axis amplifying and collimating cylindrical lens group is arranged to amplify and collimate each laser beam in the fast-axis direction, so as to reshape the rectangular spot formed by the spots of each laser beam into a square-like or square spot with the long side along the slow-axis direction unchanged and the short side along the fast-axis direction amplified.

[0007] In some embodiments, the following technical features are further included:

[0008] The fast-axis amplifying and collimating cylindrical lens group comprises a first cylindrical lens and a second cylindrical lens arranged in sequence along the direction of beam propagation, the first cylindrical lens is used for focusing and then diverging and amplifying each laser beam in the fast-axis direction, and the second cylindrical lens is used for collimating each laser beam in the fast-axis direction after the diverging and amplifying.

[0009] The first cylindrical lens and the second cylindrical lens are arranged in a distance-adjustable manner.

[0010] Each mirror is arranged in a staggered manner so that each laser beam is arranged at equal intervals along the slow-axis direction.

[0011] Each mirror is arranged so that each laser beam is turned at an angle of 90 degrees.

[0012] The plurality of single-tube LD lasers are fixed on a mounting block, the mounting block is fixed on a semiconductor refrigerator, or mounted on a water-cooled heat sink, or fixed on an air-cooled heat sink.

[0013] The plurality of collimating lenses are respectively mounted through six-degree-of-freedom adjusting frames.

[0014] The plurality of mirrors are respectively mounted through six-degree-of-freedom adjusting frames.

[0015] The application further provides the following technical solutions:

[0016] A light-curing 3D printing device has the laser beam combining and collimating device as described above.

[0017] A projector has the laser beam combining collimation device as described above.

[0018] The beneficial effects of the present application compared with the prior art include:

[0019] The laser beam combining collimation device combines and collimates multiple LD lasers, and multiple collimation lenses are correspondingly arranged in front of the multiple single-tube LD lasers, so that the light beams emitted by the LDs are collimated, the fast and slow axes are simultaneously collimated, each collimated laser beam is reflected by each reflector arranged in a staggered manner, the laser beams are arranged in a staggered manner along the slow axis direction with a smaller arrangement gap than the arrangement gap of each single-tube LD laser, and the light spots of the laser beams together form a rectangular light spot with a long side along the slow axis direction and a short side along the fast axis direction. Then, the fast axis amplification and collimation of each laser beam are performed by using a fast axis amplification collimation cylindrical lens group, so that the rectangular light spot formed by the light spots of the laser beams is reshaped into a square or nearly square light spot with an unchanged long side along the slow axis direction and an amplified short side along the fast axis direction. Thus, the present application solves the technical problems of small power, poor polarization and collimation, and poor light spot shape of the existing LD laser, meets the demand of light curing 3D printing for light power, and provides a light source with large power, good polarization, good collimation, and good light spot shape when a polarization type pattern modulation device is used to modulate a pattern in the field of illumination light source of light curing 3D printing and projector.

[0020] Compared with directly combining the powers of multiple LD lasers, the present application makes the light spot envelope after beam combining square or nearly square, and the power distribution is more uniform in the entire square area. Moreover, since the present application is a complete spatial light path without fiber coupling, and since the light emitted by each LD laser is polarized light without fiber transmission, the polarization direction of the light is not changed, so that the polarization characteristics of the overall light source are maintained.

[0021] Other beneficial effects of the embodiments of the present application will be further described below. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is an isometric view of the illumination light path of the laser beam combining collimation device in the embodiments of the present application;

[0023] Figure 2 is a top view of the illumination light path of the laser beam combining collimation device in the embodiments of the present application;

[0024] Figure 3 is a front view of the illumination light path of the laser beam combining collimation device in the embodiments of the present application;

[0025] Figure 4is a schematic diagram of spot shape change in the illumination light path of the laser beam combining and collimating device of the embodiment of the present application. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described in detail below. It should be emphasized that the following description is only exemplary and is not intended to limit the scope of the present application and its applications.

[0027] It should be noted that when an element is referred to as being "fixed" or "attached" to another element, it can be directly on the other element or indirectly on the other element, with one or more intervening elements. When an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or indirectly connected or coupled to the other element, with one or more intervening elements. Further, connections can be fixed or detachable.

[0028] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, specify relative positions or orientations based on the orientations or positions shown in the drawings, and are used only for convenience in describing the embodiments of the present application and simplifying the description, and thus cannot be construed as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus cannot be construed as limiting the present application.

[0029] In addition, the terms "first", "second", and the like, are used only for descriptive purposes, and cannot be construed as indicating or implying relative importance or an indicated number of the technical features. Thus, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0030] Reference Figures 1 to 4The embodiment of the present application provides a laser beam combining and collimating device, which comprises a plurality of single-tube LD lasers 1, a plurality of collimating lenses 4, a plurality of mirrors 5 and a fast-axis amplification and collimating cylindrical lens group (for example, shown by marks 6 and 7). The fast-axis and slow-axis directions of the plurality of single-tube LD lasers are consistent, the plurality of collimating lenses 4 are arranged in front of the plurality of single-tube LD lasers 1 one by one, and are respectively used for simultaneously collimating the laser beams emitted by each single-tube LD laser 1 in the fast-axis direction and the slow-axis direction, so that each laser beam forms an elliptical spot with the fast-axis direction as a long axis and the slow-axis direction as a short axis. Each collimated laser beam is reflected by each mirror 5, each mirror 5 is arranged in a staggered manner so that each laser beam is arranged in a staggered manner along the slow-axis direction and the arrangement gap is smaller than that of each single-tube LD laser 1, so that the spots of each laser beam together form a rectangular spot with a long side along the slow-axis direction and a short side along the fast-axis direction. The fast-axis amplification and collimating cylindrical lens group (for example, shown by marks 6 and 7) is arranged to amplify and collimate the fast-axis direction of each laser beam, so as to reshape the rectangular spot formed by the spots of each laser beam into a square-like or square spot with an unchanged long side along the slow-axis direction and an amplified short side along the fast-axis direction.

[0031] The laser divergence angles of the LD laser in the fast-axis and slow-axis directions are different, the fast-axis divergence angle is larger, usually between 20° and 40°, and the slow-axis divergence angle is smaller, usually between 8° and 15°. When the LD is combined in space, the fast-axis is collimated by a lens, and the slow-axis is also collimated to a certain extent because the original divergence angle is not large, and the divergence angle is smaller, but compared with the collimation effect of the fast-axis, the divergence angle of the slow-axis after collimation is larger than that of the fast-axis, but in the case of short-distance transmission, it can usually be regarded as parallel light and does not need special treatment.

[0032] The embodiment of the present application combines and collimates a plurality of LD lasers, and finally reshapes the direction of the flat spot to be long, realizes a square or nearly square spot, and the comprehensive effect is to obtain a lighting light source with large power, good polarization, good collimation and good spot shape. The embodiment of the present application completely combines and shapes the light emitted by a plurality of single-tube LD lasers through a spatial light path, without fiber coupling. Since the light emitted by each LD is polarized light, the LDs can be arranged at the same angle, so that the overall polarization direction is the same, and the polarization direction is not changed after fiber transmission. Therefore, the embodiment of the present application is beneficial to maintaining the polarization characteristics of the overall light source. Compared with directly combining the power of a plurality of LD lasers, the embodiment of the present application makes the spot envelope after beam combining close to a square, and the power distribution is more uniform in the entire square area.

[0033] Further, the fast-axis amplification collimating cylindrical lens group in the embodiment includes a first cylindrical lens 6 and a second cylindrical lens 7 arranged in sequence along the light beam propagation direction, the first cylindrical lens 6 is used for focusing and then diverging amplification of each laser beam in the fast-axis direction, and the second cylindrical lens 7 is used for collimation of each laser beam in the fast-axis direction after the diverging amplification. The first cylindrical lens 6 and the second cylindrical lens 7 are arranged in a distance-adjustable manner.

[0034] Preferably, the mirrors in the embodiment are arranged in a staggered manner so that the laser beams are arranged at equal intervals in the slow-axis direction. The mirrors are arranged so that the laser beams are turned at an angle of 90 degrees. The plurality of single-tube LD lasers are fixed on a mounting block, and the mounting block is fixed on a semiconductor refrigerator, or mounted on a water-cooled heat sink, or fixed on an air-cooled fin. The plurality of collimating lenses are respectively mounted through six-degree-of-freedom adjusting frames. The plurality of mirrors are respectively mounted through six-degree-of-freedom adjusting frames.

[0035] In some embodiments, the application also provides a light-cured 3D printing device with the laser beam combining and collimating device as described above.

[0036] In other embodiments, the application also provides a projector with the laser beam combining and collimating device as described above.

[0037] The embodiment of the application can provide a laser light source with high power, good polarization, good collimation, and good spot shape. The technical solution of the embodiment is to arrange a plurality of single-tube LD lasers at equal intervals and ensure that the outgoing optical axes of the single-tube LD lasers are parallel, and a collimating lens is placed in front of each single-tube LD laser to mainly collimate the fast axis and also collimate the slow axis to a certain extent. Then the collimated beams of the single-tube LD lasers enter the corresponding mirrors, the mirrors are staggered in the slow-axis direction, and the beams emitted by the single-tube LD lasers are collimated and then reflected by the mirrors, and the beams are still arranged at equal intervals in the slow-axis direction, and the arrangement gap is smaller than that of the single-tube LD lasers. However, because the number of single-tube LD lasers for beam combining is large, the final spot will form a rectangular spot with the slow axis as the long direction, the long side in the slow-axis direction, and the short side in the fast-axis direction. The rectangular spot is shaped by a group of cylindrical lenses for shaping the fast-axis direction, the short side (fast-axis direction) of the spot is enlarged, and a nearly square spot is formed, so that the beam is collimated and transmitted in a nearly square spot state.

[0038] The single-tube LD lasers in the embodiment of the application are fixed on a mounting block, the number of single-tube LD lasers is not limited, and the number is determined according to the power requirement. The mounting block is fixed on a TEC (semiconductor refrigerator), or mounted on a water-cooled heat sink, or fixed on an air-cooled heat sink, depending on the heat power of the LD laser and the application scenario.

[0039] The single tube LD laser of the embodiment of the present application has a collimating lens, which is installed and adjusted by a precise six-degree-of-freedom adjusting frame, so that the LD laser beam is collimated as required.

[0040] The mirror of the embodiment of the present application is installed and adjusted by a precise six-degree-of-freedom adjusting frame, so that the relative position of the combined beams is accurate and each beam is not blocked by the mirror.

[0041] In a preferred embodiment, the present application provides a group of single tube LD lasers, a TEC (Thermo Electric Cooler) heat sink, a group of collimating lenses, a group of mirrors, and a group of fast axis amplification cylindrical lenses, which includes two cylindrical lenses and together form the illumination light path of the LD laser beam combining and amplification.

[0042] The spot shape change in the illumination light path of the embodiment of the present application is shown in Figure 4 The emitted light of each independent single tube LD laser is collimated by its corresponding collimating lens, which mainly collimates the fast axis and also collimates the slow axis to some extent. At this time, the spot shape of the laser emitted by each single tube LD laser after collimation by the collimating lens is an approximately elliptical spot with the fast axis as the long direction and the slow axis as the short direction. Then the collimated beams of each single tube LD laser enter the corresponding mirror, and the mirrors are staggered in the slow axis direction. Because the number of single tube LD lasers for beam combining is large, the final multiple spot envelopes form a rectangular-like spot with the slow axis as the long side direction and the fast axis as the short side direction. The short side direction is amplified by a group of fast axis amplification cylindrical lenses to a length close to the length of the slow axis direction, so that the overall envelope forms a square-like spot, which is collimated and transmitted.

[0043] Embodiment 1

[0044] The embodiment of the present application provides a laser beam combining and collimating device, as shown in Figure 1 The structure includes:

[0045] The LD laser group (including a plurality of single tube LD lasers 1), the LD laser fixing block 2, the TEC semiconductor cooler 3, the collimating lens group (including a plurality of collimating lenses 4), the mirror group (including a plurality of mirrors 5), and the fast axis amplification shaping cylindrical lens group (including cylindrical lenses 6 and 7). The illumination light path of the embodiment of the present application is shown in Figure 2 and Figure 3 The specific description is as follows:

[0046] The top view of the illumination light path of the embodiment of the present application is shown in Figure 2As shown, the light beams emitted by each LD laser 1 are incident on the respective front collimating lens 4, which collimates the fast axis of the LD laser 1 and also collimates the slow axis to a certain extent. The collimated light beams are reflected by the mirror 5, which controls the direction of propagation of the light beams and makes the collimated light beams of the respective LD lasers 1 more compact in the slow axis direction, thereby obtaining an oblong light spot with the slow axis direction as the long side and the fast axis direction as the short side. The collimated light beams in the slow axis direction after reflection are not obviously changed after passing through the cylindrical lens 6 and the cylindrical lens 7.

[0047] The front view of the illumination light path of the device of the embodiment is shown in Figure 3 As shown, the light beams in the fast axis direction are first converged after passing through the cylindrical lens 6, then diverged and enlarged before reaching the cylindrical lens 7, and then collimated by the cylindrical lens 7. The cylindrical lens 6 and the cylindrical lens 7 form a fast axis enlarging and collimating cylindrical lens group, which further widens the light beams in the fast axis direction and further collimates the fast axis. The width of the light spot in the fast axis direction can be adjusted by adjusting the focal length of the two cylindrical lenses. When the length of the light spot in the fast axis direction is different from the length of the light spot arranged in the slow axis direction, a rectangular light spot envelope is formed. If the width of the light spot in the fast axis direction is the same as the width of the light spot in the slow axis direction, a square-like light spot is obtained.

[0048] The above is a further detailed description of the present application in combination with specific / preferred embodiments, and the specific implementation of the present application should not be limited to these descriptions. For those of ordinary skill in the art to which the present application belongs, without departing from the concept of the present application, they can make several substitutions or modifications to the described embodiments, and these substitutions or modifications should be regarded as falling within the protection scope of the present application. In the description of the present specification, the description of the terms "an embodiment", "some embodiments", "a preferred embodiment", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. Those skilled in the art can combine and combine the features of different embodiments or examples described in the present specification and different embodiments or examples without contradiction. Although embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of the patent application.

Claims

1. A laser beam combining collimation device, characterized in that, The laser beam combining and collimating device comprises a plurality of single-tube LD lasers, a plurality of collimating lenses, a plurality of mirrors and a fast-axis amplifying collimating cylindrical lens group, the fast-axis and slow-axis directions of the plurality of single-tube LD lasers are consistent, the plurality of collimating lenses are arranged in front of the plurality of single-tube LD lasers one by one and are respectively used for simultaneously collimating the laser beams emitted by each single-tube LD laser in the fast-axis direction and the slow-axis direction, so that each laser beam forms an elliptical spot with the fast-axis direction as the long axis and the slow-axis direction as the short axis, each collimated laser beam is reflected by each mirror, each mirror is arranged in a staggered manner so that each laser beam is arranged in a staggered manner along the slow-axis direction and the arrangement gap is smaller than the arrangement gap of each single-tube LD laser, so that the spots of each laser beam together form a rectangular spot with the slow-axis direction as the long side and the fast-axis direction as the short side, and the fast-axis amplifying collimating cylindrical lens group is arranged to amplify and collimate each laser beam in the fast-axis direction, so as to reshape the rectangular spot formed by the spots of each laser beam into a square-like or square spot with the long side along the slow-axis direction unchanged and the short side along the fast-axis direction amplified; the fast-axis amplifying collimating cylindrical lens group comprises a first cylindrical lens and a second cylindrical lens arranged in sequence along the direction of beam propagation, the first cylindrical lens is used for focusing and then diverging and amplifying each laser beam in the fast-axis direction, and the second cylindrical lens is used for collimating each laser beam after diverging and amplifying in the fast-axis direction.

2. The laser beam combining collimation device of claim 1, wherein, The first cylindrical lens and the second cylindrical lens are arranged in a distance-adjustable manner.

3. The laser beam combining collimation device of any of claims 1 to 2, wherein, Each mirror is arranged in a staggered manner so that each laser beam is arranged at equal intervals along the slow-axis direction.

4. The laser beam combining collimation device of any of claims 1 to 2, wherein, Each mirror is arranged so that each laser beam is turned at an angle of 90 degrees.

5. The laser beam combining collimation device of any of claims 1 to 2, wherein, The plurality of single-tube LD lasers are fixed on a mounting block, the mounting block is fixed on a semiconductor refrigerator, or mounted on a water-cooled heat sink, or fixed on an air-cooled heat sink.

6. The laser beam combining collimation device of any of claims 1 to 2, wherein, The plurality of collimating lenses are respectively mounted through six-degree-of-freedom adjusting frames.

7. The laser beam combining collimation device of any of claims 1 to 2, wherein, The plurality of mirrors are respectively mounted through six-degree-of-freedom adjusting frames.

8. A light-cured 3D printing device, characterized by The laser beam combining and collimating device has any one of claims 1 to 7.

9. A projector characterized by comprising: The laser beam combining and collimating device has any one of claims 1 to 7.

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