Light uniformizing rod and lighting system

Abstract

The invention relates to a dodging rod and a lighting system, the dodging rod is formed by processing based on a dodging base rod, the dodging rod is of a spiral structure and comprises a screw body and a spiral thread formed by cutting around the screw body, the spiral thread has a target thread pitch and a target depth, and the target depth is determined based on the difference value between the large diameter and the small diameter of the spiral thread. The number of times of reflection of the light beam in the dodging rod is determined based on the target pitch and / or the target depth. In the invention, the dodging rod can be formed by directly cutting based on the dodging base rod, the processing is convenient, and the setting of the required reflection times can be realized by only one dodging rod without adding other optical devices, so that the cost is saved; furthermore, the reflection times of the light beam by the light uniformizing rod can be adjusted based on the target screw pitch and the target depth of the spiral thread, so that the light uniformizing effect is conveniently adjusted, and the light uniformizing effect of the light uniformizing rod is improved.

Description

Technical Field

[0001] The invention relates to the field of optical technology, and in particular to a light homogenizing rod and an illumination system. Background Art

[0002] A light homogenizer, also called a light rod or light guide, is usually used to homogenize a light beam. In terms of structure, it can be divided into a solid light rod or a hollow light rod. A solid light rod uses the principle of total reflection to reflect the light entering the light rod multiple times before emitting it. A hollow light rod is usually formed by splicing four side walls with a high-reflection film on the inner wall. The high-reflection film on the inner wall is used to reflect the light beam entering the light rod multiple times. Since light beams with multiple divergent angles are reflected multiple times, the purpose of uniform light beam distribution can be achieved, thereby achieving the homogenization effect of the light homogenizer.

[0003] In applications such as projection illumination systems and microscopic imaging illumination systems, the light source usually uses a high-coherence, high-power laser light source. The light homogenizer is usually set at the junction of the illumination light source and the optical machine part to receive the incident light of a certain angle range emitted by the light source, and then homogenize the light beam and output it to the subsequent illumination components, enter the projection objective or microscope objective, and finally achieve uniform illumination or imaging.

[0004] In general, the traditional method uses a lens group to expand and collimate the laser beam, and then it is incident on the homogenizer. Since the divergence angle of the laser beam is very small compared to the LED light source, most of the beam directly penetrates the homogenizer, and only the beam close to the outer side of the divergence angle can be fully reflected in the homogenizer. Chinese patent announcement number CN112925104B uses an angle array homogenizer to increase the number of reflections of the beam in the homogenizer. Figure 1 As shown, this structure of the homogenizing rod is not easy to manufacture, and the sawtooth structure is only on the inner side of the homogenizing rod surface. If the light source is a laser beam, most of the beam still cannot be fully reflected and directly emits the homogenizing rod. Chinese patent announcement No. CN109946908A provides a diffraction layer containing a diffraction pattern inside or / and on the end surface of the homogenizing rod to enhance the homogenizing effect. Figure 2 As shown, although adding a diffraction layer between two homogenizing rods can diffract the laser beam to increase the divergence angle and reduce the laser beam from directly emitting the homogenizing rod without reflection, it is too costly because two homogenizing rods and an optical diffraction component are required. U.S. Patent No. 10162268B2 adopts the "Twisted kaleido" method to twist the rectangular cylindrical homogenizing rod so that the input surface and the output surface are twisted relative to each other, wherein the twist is between about 5 degrees and about 15 degrees. Figure 3As shown, although this patent increases the number of reflections of the light beam in the homogenizing rod by twisting, for a laser beam with a low divergence angle, most of the beam energy will still directly pass through the homogenizing rod without generating internal reflection. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the light homogenizing rod and the lighting system provided in the prior art are complicated to process, high in cost and have poor light homogenizing effect.

[0006] According to one aspect of the present application, a homogenizing rod is disclosed, which is formed based on a homogenizing base rod. The homogenizing rod is a spiral structure, including a screw body and a spiral thread formed by cutting around the screw body. The spiral thread has a target pitch and a target depth. The target depth is determined based on the difference between the major diameter and the minor diameter of the spiral thread. The number of reflections of the light beam in the homogenizing rod is determined based on the target pitch and / or the target depth.

[0007] In one embodiment, the light homogenizing base rod includes one of a rectangular column, a circular column, or a polyhedral column.

[0008] In one embodiment, the light homogenizing rod is a columnar structure.

[0009] In one embodiment, the light homogenizing rod is a cone structure, and includes a light incident end face and a light emitting end face, and the area of ​​the light incident end face is different from the area of ​​the light emitting end face.

[0010] According to another aspect of the present application, a lighting system is also disclosed, which includes a laser, a lens assembly, and a homogenizing rod as described in any one of the above items, wherein the laser is used to emit a laser beam, the homogenizing rod is arranged between the laser and the lens assembly, the homogenizing rod is used to reflect the laser beam to obtain a homogenized light beam and then transmit it to the lens assembly, and the lens is used to collimate and focus the homogenized light beam and then project it to a target position.

[0011] In some embodiments, the lens assembly includes a collimator and a focusing lens. The collimator is disposed between the homogenizing rod and the focusing lens. The collimator is used to collimate the homogenizing light beam to obtain a homogenizing collimated light beam. The focusing lens is used to focus the homogenizing collimated light beam to obtain a collimated focused light beam and then project the collimated focused light beam to the target position.

[0012] In some embodiments, the lighting system also includes a microlens assembly, which is disposed between the laser and the homogenizing rod. The microlens assembly is used to perform initial homogenizing focusing on the laser beam output by the laser to obtain an initial homogenizing focused beam, and then input the initial homogenizing focused beam into the homogenizing rod, so that the homogenizing rod performs further homogenizing on the initial homogenizing focused beam to obtain a target homogenizing beam.

[0013] In some embodiments, the microlens assembly includes a target layer lens array and a focusing lens, the target layer lens array is arranged between the laser and the focusing lens, the focusing lens is arranged between the target layer lens array and the homogenizing rod, the target layer lens array is used to initially homogenize the laser beam to obtain an initial homogenized beam, and the focusing lens is used to focus the initial homogenized beam to obtain the initial homogenized focused beam.

[0014] In some embodiments, the target layer lens array is a single-layer lens array or a double-layer lens array.

[0015] In some implementations, the focusing lens is a Fresnel lens.

[0016] The present invention includes but is not limited to the following beneficial effects: (1) The present invention can effectively disperse and homogenize the light beam by processing the light homogenizer into a spiral structure, so that the intensity distribution of the output light is more uniform, and hot spots and shadows are reduced; (2) Further, by controlling the target pitch size and the cutting depth (target depth) during processing, the number of reflections of the light beam in the light homogenizer can be controlled based on demand, effectively optimizing the light propagation path and improving the utilization rate of light; (3) The shape of the light homogenizer base rod (rectangle, cylinder or polyhedron) provides flexible design options, so that it can adapt to different optical requirements and installation environments; (4) The illumination system of the present invention can effectively reflect and homogenize the laser beam by placing the light homogenizer between the laser and the lens assembly, thereby ensuring the uniformity and stability of the output beam; (5) The addition of the microlens assembly allows the laser beam to undergo initial homogenization and focusing before entering the light homogenizer, thereby improving the quality of the light beam and ensuring better optical performance; (6) The design of the target layer lens array (single layer or double layer) provides flexible beam shaping capabilities, and can adjust the shape and characteristics of the light beam according to specific application requirements, further improving the uniformity and quality of the light. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0018] Figure 1It is a light homogenizing rod structure in the prior art;

[0019] Figure 2 It is another light homogenizing rod structure in the prior art;

[0020] Figure 3 It is another light homogenizing rod structure in the prior art;

[0021] Figure 4 is a structural schematic diagram of a light homogenizing rod according to an embodiment of the present invention;

[0022] Figure 5 is another structural schematic diagram of the light homogenizing rod according to an embodiment of the present invention;

[0023] Figure 6 is a structural schematic diagram of a lighting system according to an embodiment of the present invention;

[0024] Figure 7 is another structural schematic diagram of the lighting system according to an embodiment of the present invention;

[0025] Figure 8 is another structural schematic diagram of the lighting system according to an embodiment of the present invention;

[0026] Fig. 9 is a schematic diagram of the principle of a microlens assembly according to an embodiment of the present invention;

[0027] In the figure, 1-laser, 2-microlens assembly, 21-single-layer lens array, 22-double-layer lens array, 23-focusing lens, 3-light homogenizing rod, 31-light input end face, 32-light output end face, 4-lens assembly. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] The term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "inner", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0030] In order to solve the problems existing in the prior art, the present application provides a light homogenizing rod, specifically, the light homogenizing rod 3 is a spiral structure, and the light homogenizing rod 3 is formed by processing based on the light homogenizing base rod. In one example, the light homogenizing rod 3 can be formed by cutting a rectangular cylinder, or by cutting a cylinder, or by cutting a polyhedral column. It can be understood that the shape of the light homogenizing base rod processed into the light homogenizing rod 3 is not limited to the above shapes, and can also be other shapes such as irregular shapes, etc. As long as the light homogenizing rod 3 can be cut and processed, the shape of the light homogenizing base rod is not limited.

[0031] Specifically, after processing is completed, Figure 4 As shown, the light homogenizing rod 3 is a cylindrical structure, including a screw body and a spiral thread formed by cutting around the screw body, the spiral thread has a target pitch and a target depth, the target depth is determined based on the difference between the major diameter and the minor diameter of the spiral thread, and the number of reflections of the light beam in the light homogenizing rod 3 is determined based on the target pitch and / or the target depth. In one example, as Figure 4 Comparison between Figure a and Figure b in FIG. 1 shows that when the target depth remains unchanged, the number of reflections increases based on the decrease in the target pitch. Further, when the target pitch remains unchanged, the number of reflections increases based on the increase in the target depth. It is understandable that in the actual cutting process, the target pitch and the target depth can also be adjusted at the same time to meet the needs of different number of reflections.

[0032] Further, in another example, after the processing is completed, Figure 5As shown, the light homogenizing rod 3 is a cone structure, including a light incident end face 31 and a light emitting end face 32 , wherein the area of ​​the light incident end face 31 is different from the area of ​​the light emitting end face 32 . In this example, the area of ​​the light incident end face 31 is smaller than the area of ​​the light emitting end face 32 .

[0033] The present invention can effectively disperse and homogenize the light beam by processing the homogenizing rod 3 into a spiral structure, so that the intensity distribution of the output light is more uniform, and hot spots and shadows are reduced; further, by controlling the target pitch size and the cutting depth (target depth) during processing, the number of reflections of the light beam in the homogenizing rod 3 can be controlled based on demand, effectively optimizing the propagation path of the light and improving the utilization rate of the light; further, the shape of the homogenizing base rod (rectangle, cylinder or polyhedron column) provides flexible design options, so that it can adapt to different optical needs and installation environments.

[0034] Further, according to another aspect of the present application, a lighting system is also provided. In one embodiment, Figure 6 As shown, the lighting system includes a laser 1, a lens assembly 4, and a light homogenizing rod 3 of any of the above items, the laser is used to emit a laser beam, the light homogenizing rod 3 is arranged between the laser 1 and the lens assembly 4, the light homogenizing rod 3 is used to reflect the laser beam to obtain a homogenized light beam and then transmit it to the lens assembly 4, and the lens is used to collimate and focus the homogenized light beam and then project it to the target position. By placing the light homogenizing rod 3 between the laser 1 and the lens assembly 4, the laser beam can be effectively reflected and homogenized to ensure the uniformity and stability of the output beam; in one example, the lens assembly 4 includes a collimator and a focusing lens, the collimator is arranged between the light homogenizing rod 3 and the focusing lens, the collimator is used to collimate the homogenized light beam to obtain a homogenized collimated light beam, and the focusing lens is used to focus the homogenized collimated light beam to obtain a collimated focused light beam and then project the collimated focused light beam to the target position.

[0035] In some embodiments, Figure 7 and Figure 8 As shown, the lighting system also includes a microlens assembly 2, which is arranged between the laser 1 and the homogenizing rod 3. The microlens assembly 2 is used to perform initial homogenization and focusing on the laser beam output by the laser 1 to obtain an initial homogenized focused beam, and then input the initial homogenized focused beam into the homogenizing rod 3, so that the homogenizing rod 3 homogenizes the initial homogenized focused beam again to obtain a target homogenized beam. The addition of the microlens assembly 2 allows the laser beam to be initially homogenized and focused before entering the homogenizing rod 3, thereby improving the quality of the beam and ensuring better optical performance. Specifically, as Fig. 9 As shown, the microlens array combination of the microlens assembly 2 can achieve the function of light homogenization. The principle of light homogenization of the microlens array is as follows Fig. 9As shown, θ1 is the incident angle of the rear surface of the microlens array, θ2 is the exit angle, the output spot size is D, and the thickness of the microcylindrical mirror is d. The light beams are split and then superimposed on each other. The uniformity of the light field distribution depends on the number of sub-beams or the number of microlenses. Fig. 9 Only one-dimensional direction is taken as an example. The condenser is located behind the microlens array. It focuses the light beams divided by the microlens array to form the required uniform light field distribution.

[0036] In some embodiments, the microlens assembly 2 includes a target layer lens array and a focusing lens 23. The target layer lens array is arranged between the laser 1 and the focusing lens 23. The focusing lens 23 is arranged between the target layer lens array and the homogenizing rod 3. The target layer lens array is used to initially homogenize the laser beam to obtain an initial homogenized beam. The focusing lens 23 is used to focus the initial homogenized beam to obtain an initial homogenized focused beam.

[0037] In some embodiments, Figure 7 As shown, the target layer lens array can be a single layer lens array 21, such as Figure 8 As shown, the target layer lens array can be a double-layer lens array 22. The design of the target layer lens array (single layer or double layer) provides flexible beam shaping capabilities, and can adjust the shape and characteristics of the beam according to specific application requirements, further improving the uniformity and quality of light.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0039] The above shows and describes the basic principle, connection mode, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected.

Claims

1. A light homogenizing rod, characterized in that: The light homogenizing rod (3) is formed by processing a light homogenizing base rod. The light homogenizing rod (3) is a spiral structure, comprising a screw body and a spiral thread formed by cutting around the screw body. The spiral thread has a target pitch and a target depth. The target depth is determined based on the difference between the major diameter and the minor diameter of the spiral thread. The number of reflections of the light beam in the light homogenizing rod (3) is determined based on the target pitch and / or the target depth.

2. The light homogenizing rod according to claim 1, characterized in that: The light homogenizing base rod comprises one of a rectangular column, a cylindrical column or a polyhedral column.

3. The light homogenizing rod according to claim 1, characterized in that: The light homogenizing rod (3) is a columnar structure.

4. The light homogenizing rod according to claim 1, characterized in that: The light homogenizing rod (3) is a cone structure, and comprises a light incident end face (31) and a light emitting end face (32), and the area of ​​the light incident end face (31) is different from the area of ​​the light emitting end face (32).

5. A lighting system, characterized in that: The lighting system comprises a laser (1), a lens assembly (4) and a homogenizing rod according to any one of claims 1 to 4, wherein the laser is used to emit a laser beam, the homogenizing rod (3) is arranged between the laser (1) and the lens assembly (4), the homogenizing rod (3) is used to reflect the laser beam to obtain a homogenized light beam and then transmit it to the lens assembly (4), and the lens is used to collimate and focus the homogenized light beam and then project it to a target position.

6. The lighting system according to claim 5, characterized in that The lens assembly (4) comprises a collimator and a focusing lens, wherein the collimator is arranged between the light homogenizing rod (3) and the focusing lens, the collimator is used to collimate the light homogenizing beam to obtain a light homogenizing collimated beam, and the focusing lens is used to focus the light homogenizing collimated beam to obtain a collimated focused beam and then project the collimated focused beam to the target position.

7. The lighting system according to claim 6, characterized in that The lighting system further comprises a microlens assembly (2), wherein the microlens assembly (2) is arranged between the laser (1) and the light homogenizing rod (3), and the microlens assembly (2) is used for performing initial light homogenization and focusing on the laser beam output by the laser (1) to obtain an initial light homogenization and focusing beam, and then inputting the initial light homogenization beam into the light homogenizing rod (3), so that the light homogenization rod (3) performs a further light homogenization process on the initial light homogenization and focusing beam to obtain a target light homogenization beam.

8. The lighting system according to claim 7, characterized in that The microlens assembly (2) comprises a target layer lens array and a condenser lens (23); the target layer lens array is arranged between the laser (1) and the condenser lens (23); the condenser lens (23) is arranged between the target layer lens array and the light homogenizing rod (3); the target layer lens array is used to perform initial light homogenization on the laser beam to obtain an initial light homogenization beam; and the condenser lens (23) is used to focus the initial light homogenization beam to obtain the initial light homogenization focused beam.

9. The lighting system according to claim 7, characterized in that: The target layer lens array is a single-layer lens array (21) or a double-layer lens array (22).

10. The lighting system according to claim 8, characterized in that The condenser lens (23) is a Fresnel lens.

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