Laser beam speckle suppression structure

Abstract

The utility model relates to the technical field of laser projection, in particular to a laser beam speckle suppression structure, which comprises an outer frame, an X-axis homogenization structure and a Y-axis homogenization structure. The outer frame is annular, the X-axis homogenizing structure and the Y-axis homogenizing structure are vertically arranged on the annular inner side of the outer frame, the X-axis homogenizing structure is located below the Y-axis homogenizing structure, the X-axis homogenizing structure comprises an X-axis homogenizing sheet, an X-axis supporting plate and X-axis piezoelectric ceramic, the back face of the X-axis piezoelectric ceramic is fixed to the inner side of the outer frame, the X-axis supporting plate is connected with the X-axis piezoelectric ceramic, and the X-axis homogenizing sheet is connected with the X-axis piezoelectric ceramic. And the X-axis homogenizing sheet is arranged on the X-axis supporting plate. According to the utility model, the piezoelectric ceramics drive the corresponding supporting plates to perform high-frequency reciprocating motion, and the supporting plates drive the corresponding homogenizing sheets to perform reciprocating motion, so that the crossed reciprocating motion of the X-direction homogenizing sheets and the Y-direction homogenizing sheets is realized, and the effective homogenizing of laser beam speckles is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of laser projection, in particular to a laser beam speckle suppression structure. Background Art

[0002] Laser beam is a beam of light emitted by a laser and propagates in a specific direction. It has the characteristics of high directivity, high monochromaticity, high brightness and high coherence. However, the high coherence of laser will cause speckle in the laser, affecting the image quality.

[0003] In order to solve the problem of speckle, measures to reduce the coherence of the light source are often used to suppress speckle. However, when the homogenizer is stationary relative to the light beam, the utilization rate of its surface diffraction structure is low and the speckle suppression effect is poor. The motion homogenizer driven by a motor or electromagnetic electromechanical structure has problems such as large mechanical structure size and complex transmission structure. Utility Model Content

[0004] Aiming at the problem of low utilization rate of homogenizing plates, diffusion plates and space dimensions in the beam speckle homogenizer in the prior art, the utility model provides a laser beam speckle suppression structure.

[0005] The utility model is realized by the following technical solutions:

[0006] A laser beam speckle suppression structure comprises an outer frame, an X-axis homogenizing structure and a Y-axis homogenizing structure; the outer frame is annular, the X-axis homogenizing structure and the Y-axis homogenizing structure are arranged up and down on the inner side of the annular shape of the outer frame, and the X-axis homogenizing structure is located below the Y-axis homogenizing structure;

[0007] The X-axis homogenization structure includes an X-axis homogenization sheet, an X-axis support plate and an X-axis piezoelectric ceramic, the back of the X-axis piezoelectric ceramic is fixed to the inner side of the outer frame, the X-axis support plate is connected to the X-axis piezoelectric ceramic, and the X-axis homogenization sheet is installed on the X-axis support plate;

[0008] The Y-axis homogenization structure includes a Y-axis homogenization sheet, a Y-axis support plate and a Y-axis piezoelectric ceramic, the back of the Y-axis piezoelectric ceramic is fixed to the inner side of the outer frame, the Y-axis support plate is connected to the Y-axis piezoelectric ceramic, the Y-axis homogenization sheet is arranged on the Y-axis support plate, and the X-axis homogenization sheet and the Y-axis homogenization sheet have the same size and position, and the movement direction of the X-axis homogenization sheet is orthogonal to the movement direction of the Y-axis homogenization sheet;

[0009] Two X-axis piezoelectric ceramics and two Y-axis piezoelectric ceramics are provided, and the arrangement of the X-axis piezoelectric ceramics and the Y-axis piezoelectric ceramics is similar. Taking the arrangement of the X-axis piezoelectric ceramics as an example, the two X-axis piezoelectric ceramics are relatively arranged on both sides of the X-axis homogenizing plate, and the X-axis homogenizing plate is operated in a push-pull manner through the X-axis piezoelectric ceramics.

[0010] Preferably, the X-axis support plate and the Y-axis support plate are both made of resin material.

[0011] Preferably, a light-through hole is opened on the X-axis support plate, and the X-axis homogenizing plate is arranged at the light-through hole; the connection method between the Y-axis homogenizing plate and the Y-axis support plate is the same as the connection method between the X-axis support plate and the X-axis homogenizing plate.

[0012] Preferably, both the X-axis homogenizing plate and the Y-axis homogenizing plate are matched with the light-through hole by optical glue.

[0013] Preferably, the material, size and shape of the X-axis homogenizing piece and the Y-axis homogenizing piece are the same.

[0014] Preferably, the connection method between the X-axis piezoelectric ceramic and the outer frame is the same as the connection method between the Y-axis piezoelectric ceramic and the outer frame. Taking the connection between the X-axis piezoelectric ceramic and the outer frame as an example, an installation groove is provided on the inner side of the outer frame, and the piezoelectric ceramic is located in the installation groove.

[0015] Preferably, the length of the mounting groove is greater than the length of the X-axis piezoelectric ceramic.

[0016] Preferably, the X-axis piezoelectric ceramics and the Y-axis piezoelectric ceramics are arranged in a staggered manner.

[0017] Preferably, the connection method between the X-axis piezoelectric ceramic and the X-axis support plate is the same as the connection method between the Y-axis piezoelectric ceramic and the Y-axis support plate. Taking the connection method between the X-axis piezoelectric ceramic and the X-axis support plate as an example, a mating groove is provided on the side of the X-axis piezoelectric ceramic close to the X-axis support plate, the side edge of the X-axis support plate is located in the mating groove, and the side edge of the X-axis support plate and the mating groove are mated with a mortise and tenon structure.

[0018] Preferably, a plurality of support plates are also provided on the inner side of the outer frame, and the support plates are provided below the X-axis support plate or the Y-axis support plate.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] The utility model is a laser beam speckle suppression structure that drives the corresponding support plate to perform high-frequency reciprocating motion through piezoelectric ceramics, and the support plate drives the corresponding homogenizing sheet to perform reciprocating motion, and uses double-layer homogenization to eliminate speckles in orthogonal directions, and prevents periodic fluctuations caused by single-axis motion homogenization, thereby realizing the cross-reciprocating motion of the X-direction homogenizing sheet and the Y-direction homogenizing sheet, and realizing double-layer homogenization decoherence of laser beam speckle through two two-dimensional motion structures. At the same time, by reasonably arranging the positions of various functional structures, the space is fully utilized, the space occupied by the entire device is reduced, and the optical path design of the laser projection system is more flexible.

[0021] Furthermore, the inherent resonant frequency and amplitude of the piezoelectric ceramic are limited in order to avoid the sensing range of the human ear.

[0022] Furthermore, the support plate and the piezoelectric ceramics matched with the mortise and tenon structure can achieve a matching connection between the two to prevent the support plate from falling off during movement.

[0023] Furthermore, the two piezoelectric ceramics of the same homogenizing plate act in a push-pull manner, which can increase the driving ability and stability of the homogenizing support plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a laser beam speckle suppression structure of the utility model;

[0025] Figure 2 It is a schematic diagram of another viewing angle of a laser beam speckle suppression structure of the utility model;

[0026] Figure 3 It is a schematic diagram of the internal structure of a laser beam speckle suppression structure of the utility model;

[0027] Figure 4 The utility model is a schematic diagram of the movement of an X-axis homogenizer and a Y-axis homogenizer in a laser beam speckle suppression structure.

[0028] In the figure, 1. outer frame; 2. Y-axis support plate; 3. X-axis support plate; 4. X-axis piezoelectric ceramic; 4-1. first X-axis piezoelectric ceramic; 4-2. second X-axis piezoelectric ceramic; 5. Y-axis support plate; 6. Y-axis homogenizing plate; 7. X-axis homogenizing plate; 8. Y-axis piezoelectric ceramic; 8-1. first Y-axis piezoelectric ceramic; 8-2. second Y-axis piezoelectric ceramic; 9. X-axis support plate; 10. fixing bolts. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0030] The utility model discloses a laser beam speckle suppression structure, referring to Figure 1 , 2 , 3, comprising an outer frame 1, an X-axis homogenizing structure and a Y-axis homogenizing structure; the outer frame 1 is annular, the X-axis homogenizing structure and the Y-axis homogenizing structure are arranged up and down on the inner side of the ring of the outer frame 1, and the X-axis homogenizing structure is located below the Y-axis homogenizing structure; in this embodiment, the size of the outer frame is 15*15mm and the thickness is 1.5mm.

[0031] The X-axis homogenization structure includes an X-axis homogenization sheet 7, an X-axis support plate 9 and an X-axis piezoelectric ceramic 4. The back of the X-axis piezoelectric ceramic 4 is fixed to the inner side of the outer frame 1, the X-axis support plate 9 is connected to the X-axis piezoelectric ceramic 4, and the X-axis homogenization sheet 7 is installed on the X-axis support plate 9.

[0032] The Y-axis homogenization structure includes a Y-axis homogenization sheet 6, a Y-axis support plate 5 and a Y-axis piezoelectric ceramic 8. The back of the Y-axis piezoelectric ceramic 8 is fixed to the inner side of the outer frame 1. The Y-axis support plate 5 is connected to the Y-axis piezoelectric ceramic 8. The Y-axis homogenization sheet 6 is arranged on the Y-axis support plate 5, and the X-axis homogenization sheet 7 and the Y-axis homogenization sheet 6 have the same size and position, and the movement direction of the X-axis homogenization sheet 7 is orthogonal to the movement direction of the Y-axis homogenization sheet 6.

[0033] Among them, the X-axis support plate 9 and the Y-axis support plate 5 are both made of resin material, and a light-through hole is opened on the X-axis support plate 9, and the X-axis homogenizer 7 is arranged at the light-through hole; the connection method of the Y-axis homogenizer 6 and the Y-axis support plate 5 is the same as the connection method of the X-axis support plate 9 and the X-axis homogenizer 7; the material, size and shape of the X-axis homogenizer 7 and the Y-axis homogenizer 6 are the same. In this embodiment, the size of the light-through hole of the X-axis support plate is a rectangle of 8*8mm; the X-axis homogenizer 7 and the Y-axis homogenizer 6 are both matched with the light-through hole through optical glue. There is no requirement for the vertical distance between the X-axis homogenizer 7 and the Y-axis homogenizer 6, as long as the size of the two groups of piezoelectric ceramics is met, such as 5mm. The homogenizer uses the pit microstructure etched on the optical resin or optical glass flat lens as a scatterer. The smaller the size of the scatterer unit, the more obvious the diffraction effect is, and the more obvious the beam expansion and homogenization is. The size of the general scatterer unit is 1-10um.

[0034] There are two X-axis piezoelectric ceramics 4 and two Y-axis piezoelectric ceramics 8. The arrangement of the X-axis piezoelectric ceramics 4 and the Y-axis piezoelectric ceramics 8 is the same. Taking the arrangement of the X-axis piezoelectric ceramics 4 as an example, the two X-axis piezoelectric ceramics 4 are relatively arranged on both sides of the X-axis homogenizing sheet 7. Figure 4 The X-axis homogenizing plate 7 is operated in a push-pull manner through the X-axis piezoelectric ceramic 4, that is, when the thickness of one piezoelectric ceramic increases, the thickness of the other piezoelectric ceramic decreases. Piezoelectric ceramics generally have their own inherent resonant frequency, and the amplitude can reach the maximum when resonating, which is about hundreds to tens of kilohertz depending on the size. The amplitude and frequency of the X-axis piezoelectric ceramic 4 and the Y-axis piezoelectric ceramic 8 are the same. In this embodiment, the X-axis piezoelectric ceramic 4 and the Y-axis piezoelectric ceramic 8 both move at a frequency of 140Hz, and the maximum amplitude is ±100um.

[0035] The X-axis piezoelectric ceramics 4 and the Y-axis piezoelectric ceramics 8 are staggered, that is, the two X-axis piezoelectric ceramics 4 are located on two opposite sides of the outer frame 1 , and the two Y-axis piezoelectric ceramics 8 are located on the other two opposite sides of the outer frame 1 .

[0036] The connection method of the X-axis piezoelectric ceramic 4 and the outer frame 1 is the same as the connection method of the Y-axis piezoelectric ceramic 8 and the outer frame. Taking the connection of the X-axis piezoelectric ceramic 4 and the outer frame 1 as an example, a mounting groove is provided on the inner side of the outer frame 1, the piezoelectric ceramic is located in the mounting groove, and the back side of the X-axis piezoelectric ceramic 4 is fixedly connected by a fixing bolt 10 that passes through the outer side of the outer frame. In this embodiment, the length of the mounting groove is greater than the length of the X-axis piezoelectric ceramic 4.

[0037] The connection method between the X-axis piezoelectric ceramic 4 and the X-axis support plate 9 is the same as the connection method between the Y-axis piezoelectric ceramic 8 and the Y-axis support plate 5. Taking the connection method between the X-axis piezoelectric ceramic 4 and the X-axis support plate 9 as an example, a mating groove is opened on the side of the X-axis piezoelectric ceramic 4 close to the X-axis support plate 9, the side edge of the X-axis support plate 9 is located in the mating groove, and the side edge of the X-axis support plate 9 and the mating groove are matched with a mortise and tenon structure.

[0038] The inner side of the outer frame 1 is also connected to a plurality of support plates by fixing bolts 10, and the support plates are arranged below the X-axis support plate 9 or the Y-axis support plate 5. Figure 3 The support plates are recorded as X-axis support plate 3 and Y-axis support plate 2 according to their positions. The X-axis support plate 3 is located below the X-axis support plate 9, and the Y-axis support plate 2 is located below the Y-axis support plate 5.

[0039] The implementation principle of the laser beam speckle suppression structure of the utility model is:

[0040] When in use, a collimated light beam is incident perpendicularly to the surface of the homogenizer, and a homogenized light beam with a certain divergence is emitted from the surface of another homogenizer. The upper and lower homogenizers are completely identical and can be used as input or output at will.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and replacements, and these modifications and replacements are also within the scope of protection covered by the claims.

Claims

1. A laser beam speckle suppression structure, characterized in that: It comprises an outer frame (1), an X-axis homogenizing structure and a Y-axis homogenizing structure; the outer frame (1) is annular, the X-axis homogenizing structure and the Y-axis homogenizing structure are arranged up and down on the inner side of the annular shape of the outer frame (1), and the X-axis homogenizing structure is located below the Y-axis homogenizing structure; The X-axis homogenization structure comprises an X-axis homogenization sheet (7), an X-axis support plate (9) and an X-axis piezoelectric ceramic (4), the back side of the X-axis piezoelectric ceramic (4) is fixed to the inner side of the outer frame (1), the X-axis support plate (9) is connected to the X-axis piezoelectric ceramic (4), and the X-axis homogenization sheet (7) is mounted on the X-axis support plate (9); The Y-axis homogenization structure comprises a Y-axis homogenization sheet (6), a Y-axis support plate (5) and a Y-axis piezoelectric ceramic (8), wherein the back of the Y-axis piezoelectric ceramic (8) is fixed to the inner side of the outer frame (1), the Y-axis support plate (5) is connected to the Y-axis piezoelectric ceramic (8), the Y-axis homogenization sheet (6) is arranged on the Y-axis support plate (5), and the X-axis homogenization sheet (7) and the Y-axis homogenization sheet (6) have the same size and position, and the movement direction of the X-axis homogenization sheet (7) is orthogonal to the movement direction of the Y-axis homogenization sheet (6); Two X-axis piezoelectric ceramics (4) and two Y-axis piezoelectric ceramics (8) are provided, and the arrangement of the X-axis piezoelectric ceramics (4) and the Y-axis piezoelectric ceramics (8) is similar. Taking the arrangement of the X-axis piezoelectric ceramics (4) as an example, the two X-axis piezoelectric ceramics (4) are arranged on both sides of the X-axis homogenizing plate (7) in a relative manner, and the X-axis homogenizing plate (7) is operated in a push-pull manner through the X-axis piezoelectric ceramics (4).

2. The laser beam speckle suppression structure according to claim 1, characterized in that: The X-axis support plate (9) and the Y-axis support plate (5) are both made of resin material.

3. The laser beam speckle suppression structure according to claim 1, characterized in that: The X-axis support plate (9) is provided with a light-through hole, and the X-axis homogenizing plate (7) is arranged at the light-through hole; the connection mode of the Y-axis homogenizing plate (6) and the Y-axis support plate (5) is the same as the connection mode of the X-axis support plate (9) and the X-axis homogenizing plate (7).

4. The laser beam speckle suppression structure according to claim 3, characterized in that: The X-axis homogenizing plate (7) and the Y-axis homogenizing plate (6) are both matched with the light-through hole by optical glue.

5. The laser beam speckle suppression structure according to claim 1, characterized in that: The material, size and shape of the X-axis homogenizing piece (7) and the Y-axis homogenizing piece (6) are the same.

6. The laser beam speckle suppression structure according to claim 1, characterized in that: The connection method of the X-axis piezoelectric ceramic (4) and the outer frame (1) is the same as the connection method of the Y-axis piezoelectric ceramic (8) and the outer frame (1). Taking the connection of the X-axis piezoelectric ceramic (4) and the outer frame (1) as an example, a mounting groove is provided on the inner side of the outer frame (1), and the piezoelectric ceramic is located in the mounting groove.

7. The laser beam speckle suppression structure according to claim 6, characterized in that: The length of the mounting groove is greater than the length of the X-axis piezoelectric ceramic (4).

8. The laser beam speckle suppression structure according to claim 1, characterized in that: The X-axis piezoelectric ceramic (4) and the Y-axis piezoelectric ceramic (8) are arranged in a staggered manner.

9. The laser beam speckle suppression structure according to claim 1, characterized in that: The connection method between the X-axis piezoelectric ceramic (4) and the X-axis support plate (9) is the same as the connection method between the Y-axis piezoelectric ceramic (8) and the Y-axis support plate (5). Taking the connection method between the X-axis piezoelectric ceramic (4) and the X-axis support plate (9) as an example, a matching groove is provided on the side of the X-axis piezoelectric ceramic (4) close to the X-axis support plate (9), the side of the X-axis support plate (9) is located in the matching groove, and the side of the X-axis support plate (9) and the matching groove are matched with a mortise and tenon structure.

10. The laser beam speckle suppression structure according to claim 8, characterized in that: A plurality of support plates are also arranged on the inner side of the outer frame (1), and the support plates are arranged below the X-axis support plate (9) or the Y-axis support plate (5).

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