Projection device based on microlens array

Abstract

The utility model relates to the technical field of microlens arrays, in particular to a projection device based on a microlens array, which comprises a fixed bottom plate, a receiving screen surface is arranged at the right end of the top of the fixed bottom plate, and a lens support is arranged at the top of the fixed bottom plate and positioned on the left side of the receiving screen surface. A lens support is arranged on the left side of the top of the fixing bottom plate, a Fresnel lens is installed on the top of the lens support, a rotating motor is arranged on the left side of the top of the fixing bottom plate, and a gear is arranged on the top of the rotating motor. The distance between the first micro-lens array and the second micro-lens array can be adjusted, the problem of light path placement is solved, the convex surfaces of the first micro-lens array and the second micro-lens array are outward, the planes of the first micro-lens array and the second micro-lens array are opposite, and the distance between the first micro-lens array and the second micro-lens array is the length of focal length. After the light path is placed, the distance between the light paths is adjusted in this way, so that the size and the effect of shaping light spots of the flat-topped light are finely adjusted.

Description

Technical Field

[0001] The utility model relates to the technical field of microlens arrays, in particular to a projection device based on a microlens array. Background Art

[0002] In the field of laser processing, it is often required that the energy distribution of the emitted laser be flat and uniform, which is often called laser homogenization, and the light source is flat-topped. For different lasers, there are three common types of lenses on the market, namely microlens arrays, DOE elements, and aspherical mirrors. And this type of lens is subdivided into many different lenses. Among them, the microlens array is an ROE type element, which has the characteristics of wide applicable wavelength, low cost, and good homogenization effect. Common microlens array homogenization light paths include single-piece microlens arrays, that is, double-sided microlens arrays or double-sided compound eye lenses. The other is a microlens homogenization light path with two plano-convex compound eye lenses.

[0003] A Chinese patent (publication number: CN 218728568 U, publication date: 2023.03.24) discloses a projection based on a microlens array. The features provided in the above document include a light source, a collimator, and a microlens array. The collimator is arranged between the light source and the microlens array. The microlens array includes a field lens array and a projection lens array arranged in sequence along the propagation direction of the light. The collimator of the projection device is configured based on the structural parameters of the microlens array, and the divergence angle of the light beam behind it is controlled to be small enough, which can effectively generate stray light behind the microlens array and ensure the imaging quality of the projection device.

[0004] However, the above document cannot fine-tune the size and effect of the flat-top light shaping spot, which ultimately affects the imaging of the target light spot formed on the receiving screen.

[0005] Therefore, it is particularly important to design a projection device based on a microlens array to change the above technical defects and improve the overall practicality. Utility Model Content

[0006] The purpose of the utility model is to provide a projection device based on a microlens array to solve the problems raised in the above background technology.

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] A projection device based on a microlens array comprises a fixed bottom plate, a receiving screen is arranged at the right end of the top of the fixed bottom plate, and a lens holder is arranged at the top of the fixed bottom plate and on the left side of the receiving screen. A Fresnel lens is installed on the top of the lens holder, a rotating motor is arranged on the left side of the top of the fixed bottom plate, a gear is arranged on the top of the rotating motor, a slide rail is arranged on the left side of the top of the fixed bottom plate and on both the front and rear sides of the rotating motor, a sliding sleeve is sleeved on the outer side of the slide rail, a rack meshing with the gear is fixed on the inner side of the sliding sleeve, and a first microlens array and a second microlens array are installed on the tops of two groups of the racks, respectively.

[0009] As a preferred solution of the utility model, a controller is arranged on the outer side of the fixed base plate, wherein the controller and the rotating motor are connected via a wire, and the connection method is electrical connection.

[0010] As a preferred solution of the present invention, the connection between the slide rail and the slide sleeve is a sliding connection.

[0011] As a preferred solution of the utility model, the two groups of sliding sleeves are respectively located at the left and right ends of the slide rail.

[0012] As a preferred solution of the utility model, the first microlens array and the second microlens array are designed with convex surfaces facing outwards and planes facing each other.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] In the utility model, a projection device based on a microlens array is set up, and a rotating motor drives the rotation of a gear to drive two sets of racks to move in the same and opposite directions, so that the distance between the first microlens array and the second microlens array can be adjusted, thereby solving the problem of light path placement. The first microlens array and the second microlens array are convex surfaces facing outwards and planes facing each other. The distance between the two is the length of the focal length. After the light path is placed, the distance between them is adjusted in this way to fine-tune the size and effect of the flat-top light shaping spot. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the main view of the overall structure of the utility model;

[0016] Figure 2 It is a schematic diagram of the local structure of the utility model;

[0017] Figure 3 It is a partial structural top view of the utility model.

[0018] In the figure: 1, fixed base plate; 2, receiving screen; 3, lens bracket; 4, Fresnel lens; 5, rotating motor; 501, gear; 502, slide rail; 503, sleeve; 504, rack; 505, first microlens array; 506, second microlens array. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0020] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings, and several embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0021] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this article includes any and all combinations of one or more related listed items.

[0023] For examples, see Figure 1-3 , the utility model provides a technical solution:

[0024] A projection device based on a microlens array comprises a fixed bottom plate 1, a receiving screen 2 is arranged at the right end of the top of the fixed bottom plate 1, and a lens holder 3 is arranged at the top of the fixed bottom plate 1 and on the left side of the receiving screen 2. A Fresnel lens 4 is installed on the top of the lens holder 3, and a rotating motor 5 is arranged on the left side of the top of the fixed bottom plate 1;

[0025] A controller is disposed on the outer side of the fixed base plate 1 for controlling the rotating motor 5 , wherein the controller and the rotating motor 5 are connected via a wire, and the connection is electrical.

[0026] In this embodiment, please refer to Figure 1 and Figure 2 and Figure 3 A gear 501 is provided on the top of the rotating motor 5, and slide rails 502 are provided on the left side of the top of the fixed bottom plate 1 and on both the front and rear sides of the rotating motor 5. A sliding sleeve 503 is sleeved on the outer side of the sliding rail 502, and a rack 504 meshing with the gear 501 is fixed on the inner side of the sliding sleeve 503. The tops of the two groups of racks 504 are respectively installed with a first microlens array 505 and a second microlens array 506. The rotating motor 5 drives the gear 501 to rotate, thereby driving the two groups of racks 504 to move in the same and opposite directions, so that the distance between the first microlens array 505 and the second microlens array 506 can be adjusted;

[0027] The connection between the slide rail 502 and the slide sleeve 503 is a sliding connection. The two sets of slide sleeves 503 are respectively located at the left and right ends of the slide rail 502. The first microlens array 505 and the second microlens array 506 are convexly facing outwards, and the planes are designed to be opposite.

[0028] The working process of the utility model is as follows: after the laser light source is expanded and collimated, it is incident in parallel. The incident laser beam hits the first microlens array 505 and the second microlens array 506. After being focused by each sub-unit, the focus of the array arrangement is re-formed. The incident light beam can be approximately regarded as a beam cluster array corresponding to the lens array. The multiple small light beams after refocusing are superimposed on each other. After passing through the Fresnel lens 4, based on the symmetry of the array arrangement, that is, the symmetry of the emitted small light beams, the unevenness of the small light beams cancel each other out, and finally a uniform target light spot is formed on the receiving screen 2. The calculation formula of the final light spot is as follows: DFT= pLA•fFL / fLA2, during the process, the rotating motor 5 drives the gear 501 to rotate, thereby driving the two sets of racks 504 to move in the same and opposite directions, so that the distance between the first microlens array 505 and the second microlens array 506 can be adjusted to solve the problem of light path placement. The first microlens array 505 and the second microlens array 506 are convex surfaces facing outwards and the planes are opposite to each other. The distance between the two is the length of the focal length. After the light path is placed, the distance between them is adjusted in this way to fine-tune the size and effect of the flat-top light shaping spot.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A projection device based on a microlens array, comprising a fixed base plate (1), characterized in that: A receiving screen (2) is arranged at the right end of the top of the fixed base plate (1), a lens holder (3) is arranged at the top of the fixed base plate (1) and located on the left side of the receiving screen (2), and a Fresnel lens (4) is mounted on the top of the lens holder (3). A rotating motor (5) is arranged on the left side of the top of the fixed base plate (1), and a gear (501) is arranged on the top of the rotating motor (5). Slide rails (502) are arranged on the left side of the top of the fixed base plate (1) and located on both the front and rear sides of the rotating motor (5). A sliding sleeve (503) is sleeved on the outer side of the sliding rail (502), and a rack (504) meshing with the gear (501) is fixed on the inner side of the sliding sleeve (503). A first microlens array (505) and a second microlens array (506) are mounted on the tops of two groups of the racks (504), respectively.

2. A projection device based on a microlens array according to claim 1, characterized in that: A controller is arranged on the outer side of the fixed base plate (1), wherein the controller and the rotating motor (5) are connected via a wire, and the connection is in an electrical manner.

3. The projection device based on a microlens array according to claim 1, characterized in that: The connection between the slide rail (502) and the slide sleeve (503) is a sliding connection.

4. The projection device based on a microlens array according to claim 1, characterized in that: The two sets of sliding sleeves (503) are respectively located at the left and right ends of the sliding rail (502).

5. The projection device based on a microlens array according to claim 1, characterized in that: The first microlens array (505) and the second microlens array (506) are designed with convex surfaces facing outwards and planes facing each other.

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