阅读说明：本技术 基于微机电光调制器的光路系统、全息瞄准装置及应用 (Light path system based on micro-electromechanical light modulator, holographic aiming device and application ) 是由 朱兵兵 董英琴 于 2021-08-26 设计创作，主要内容包括：本发明涉及一种基于微机电光调制器的光路系统,光路系统上沿着光传播的方向依次设有光源、第一准直装置、微机电光调制器、第二准直装置、全息透镜和全息片；光源为可见光波段的半导体激光器。本发明还涉及一种基于微机电光调制器的光路系统在全息瞄准装置上的应用以及一种全息瞄准装置。本发明利用微机电光调制器完成光源扩束,可以很好地解决全息枪瞄中的系统体积大,视窗受限,亮度调节范围有限及热能大的问题。(The invention relates to an optical path system based on a micro-electromechanical light modulator, wherein a light source, a first collimating device, the micro-electromechanical light modulator, a second collimating device, a holographic lens and a holographic sheet are sequentially arranged on the optical path system along the light propagation direction; the light source is a semiconductor laser with visible light wave band. The invention also relates to an application of the light path system based on the micro-electromechanical light modulator in the holographic aiming device and the holographic aiming device. The invention uses the micro-electromechanical light modulator to complete light source beam expansion, and can well solve the problems of large system volume, limited window, limited brightness adjusting range and large heat energy in the holographic gun aiming.)

1. The micro-electro-mechanical light modulator-based light path system is characterized in that a light source, a first collimating device, a micro-electro-mechanical light modulator, a second collimating device, a holographic lens and a holographic sheet are sequentially arranged on the light path system along the light propagation direction; the light source is a semiconductor laser with a visible light waveband; the first collimating device is an aspheric collimating lens or a graded index lens; the second collimating device is a collimating lens or a curved reflector with the function of collimating light beams.

2. The mems light modulator-based optical path system of claim 1, wherein the light source, the first collimating device, the mems light modulator, the second collimating device, and the holographic lens are distributed on an upper portion and a lower portion of a same side of the holographic plate.

3. The mems light modulator-based optical path system of claim 1, wherein the light source, the first collimating device, the mems light modulator, the second collimating device, and the holographic lens are distributed on a lower portion of a same side of the holographic plate.

4. The micro-electromechanical light modulator-based optical path system according to any one of claims 1 to 3, wherein the micro-electromechanical light modulator is a biaxial micro-electromechanical scanning galvanometer.

5. The micro-electromechanical light modulator-based light path system according to any one of claims 1 to 3, wherein the distance d between the first collimating device and the light emitting point of the light source is less than 3 mm.

6. The light path system based on the micro electro mechanical light modulator as claimed in any one of claims 1 to 3, wherein a focal position of the second collimating device coincides with a center point of the micro electro mechanical light modulator.

7. The micro-electromechanical light modulator-based optical path system according to any one of claims 1 to 3, wherein the holographic lens is a Bragg reflection grating.

8. The micro-electromechanical light modulator-based optical path system according to any one of claims 1 to 3, wherein the hologram is a holographic dry plate, a holographic volume grating or a holographic medium sheet on which a divisional holographic image is recorded.

9. An application of an optical path system based on a Micro Electro Mechanical System (MEMS) light modulator in a holographic aiming device is characterized in that the optical path system is the optical path system based on the MEMS light modulator as claimed in claims 1-8, and a light beam emitted by a light source sequentially passes through a first collimating device, the MEMS light modulator, a second collimating device and a holographic lens, then is obliquely incident to the front surface of a holographic sheet and is emitted in parallel perpendicular to the back surface of the holographic sheet.

10. A holographic aiming device, characterized in that it comprises the micro-electromechanical light modulator-based optical path system as claimed in claims 1 to 8.

Technical Field

The invention relates to an optical path system, in particular to an optical path system based on a micro-electromechanical light modulator, a holographic aiming device and application.

Background

The holographic technique is essentially a light field reconstruction, which is largely divided into two steps, namely the recording of the optical information (amplitude and phase) emitted by the object and the reconstruction of the object image. The holographic dry plate recorded with the holographic image has the following characteristics: the system can store all information of object light waves, can reproduce a three-dimensional image of an object under a characteristic condition, and can present the image at a distance (from several meters to several hundred meters); in addition, all the information of the object appearance is recorded at each part of the holographic dry plate, so the holographic dry plate has the characteristic that the same image can still be presented at the same position after being broken. In view of the characteristics, the holographic sighting telescope based on the holographic technology can be used for light weapons, and has the characteristics of quick and accurate sighting under severe conditions and difficulty in being detected by enemies.

The design of the optical system of the holographic sighting telescope has been the focus of research until now. At present, the optical path system of a general holographic sight mainly includes a light source, a holographic dry plate, and some optical elements for collimation, beam expansion, filtering, reflection, etc. The working principle is as follows: light emitted by the light source is expanded by the lens (or expanded after passing through a certain optical path based on the divergence angle of the light source), is collimated by the optical collimating element and then is incident to the holographic dry plate recorded with the differentiation holographic information, and then a differentiation image is reproduced. According to the holographic theory, the change of the wavelength of the illuminating light during the hologram imaging process will cause the shift of the reconstructed divided image, and in order to correct the position shift, a holographic lens (transmission or reflection grating) is usually added in front of the holographic dry plate for aberration compensation, so that the image position shift caused by the wavelength change can be effectively inhibited. In order to cover the whole holographic plate by illumination, the whole system must use beam expanding device or prolong optical path to enlarge light spot size, so that it can obtain good illumination effect

The method for adjusting the brightness in the current aiming system aiming at different use scenes comprises the following steps: light intensity adjustment of the light source, frequency modulation of the light source, and adjustment of light transmittance using a light modulator, an aperture, or the like. However, the light energy density of the light energy of the light source after being expanded is very limited, and the requirement of increasing the contrast can be met only by selecting a laser with higher power in the use environment with strong illumination, so that the problems of power consumption and heat dissipation of the light source are caused.

Patent CN101275818A discloses a holographic gun aiming optical path system, which comprises a laser diode, a plane mirror, a holographic lens and a holographic dry plate. The laser diode provides light source for the system, the plane reflector is used for changing the direction of the light beam, and the holographic lens is used for collimating, turning and filtering the light passing through the reflector. The beam expanding system is not used in the optical path system, and the beam expansion is realized depending on the length of the optical path, so the system has larger volume; in addition, the system uses the holographic lens to finish the collimation of the light beam, and because the light source is a diffusion light source, the light beam collimation realized by the filtering action of the holographic lens can cause a large amount of light energy loss, so that the holographic display brightness is weakened, and the environmental contrast is reduced.

The U.S. Pat. No. 4, 5483362B discloses a holographic sighting telescope optical system comprising only 3 components, including a semiconductor laser light source, a reflective focusing diffraction grating and a holographic differentiation plate, wherein the system has a simple design structure but also faces the problems of large volume and difficulty in manufacturing the reflective focusing diffraction grating; on the basis, EOTech company has invented a new kind of holographic aiming optical system, this system includes semiconductor laser device, level mirror, collimation reflector, reflective holographic lens and holographic reticle (US6490060B), use the reflective collimator to realize the collimation of the light beam in this invention, in addition its light path design ingenious point lies in utilize rotatable level mirror and top collimation reflector placed step by step to change the propagation direction of the illumination light from horizontal to vertical, have realized the folding of the light path in the vertical direction, have greatly reduced the volume of the sighting telescope in the horizontal direction, have reduced the size of the whole sighting telescope. However, the size of this type of window depends on the length of the optical path, and the beam must be expanded to obtain a larger window. In addition, the two methods for adjusting the image brightness are realized by adjusting the output power of the laser by a pulse width modulation method, the whole holographic plate is irradiated by laser after beam expansion, the brightness uniformity problem exists, the image brightness is influenced by enlarging a window, only the laser with higher power can be selected for balancing the brightness, and other power consumption and heat energy problems are caused.

Disclosure of Invention

The invention aims to provide a light path system based on a micro-electromechanical light modulator, which can well solve the problems of large system volume, limited window, limited brightness adjusting range and large heat energy in holographic aiming by using the micro-electromechanical light modulator to finish light source beam expansion.

In order to achieve the above purpose, the light path system based on the micro electro mechanical system light modulator of the present invention is provided with a light source, a first collimating device, the micro electro mechanical system light modulator, a second collimating device, a holographic lens and a holographic sheet in sequence along the light propagation direction; the light source is a semiconductor laser with a visible light waveband (400 nm-700 nm); the first collimating device is an aspheric collimating lens or a graded index lens; the second collimating device is a collimating lens or a curved reflector with the function of collimating light beams.

The light beam emitted by the light source sequentially passes through the first collimating device, the micro electro mechanical light modulator, the second collimating device and the holographic lens, then is incident to the front surface of the holographic plate at an inclined angle and is emitted in parallel in a manner of being vertical to the back surface of the holographic plate, so that human eyes can see the restored image of the hologram recorded in the holographic plate through the second surface of the holographic plate

Optionally, the light source, the first collimating device, the micro-electromechanical light modulator, the second collimating device, and the holographic lens are distributed on the upper portion and the lower portion of the same side of the holographic plate.

Optionally, the light source, the first collimating device, the micro-electromechanical light modulator, the second collimating device, and the holographic lens are distributed at a lower portion of the same side of the holographic plate.

Preferably, the micro-electromechanical light modulator is a double-shaft micro-electromechanical scanning galvanometer, and the double-shaft micro-electromechanical scanning galvanometer is actually a tiny reflecting mirror which can be electrically driven and can be movably turned over, so that scanning in two directions of an axis and a slow axis can be realized.

Preferably, the distance D between the first collimating device and the light emitting point of the light source is less than 3mm to ensure that the diameter D of the collimated thin light beam is small, and if the divergence angle of the light source is the full angle

Specifically, the focal position of the second collimating device coincides with the central point of the micro-electromechanical light modulator, so that the light reflected from the micro-electromechanical light modulator is emitted in parallel through the collimating lens.

In particular, the holographic lens is a bragg reflection grating, which has excellent angular selectivity and can offset a holographic image position change of a light source due to temperature drift.

Specifically, the holographic plate is a holographic dry plate, a holographic volume grating or a holographic medium plate on which a divisional holographic image is recorded.

The working principle is as follows: the laser beamlets passing through the first collimating device irradiate the central point of the reflecting mirror surface of the micro electro mechanical system light modulator, are projected onto the subsequent second collimating device through a fast two-dimensional scanning speed, then are incident to the holographic lens in the same direction, and finally are incident to the holographic sheet at an oblique angle.

Another object of the present invention is to provide an application of the optical path system based on the micro-electromechanical light modulator in the holographic aiming device.

The light source emits light beams which sequentially pass through the first collimating device, the micro-electromechanical light modulator, the second collimating device and the holographic lens, then the light beams are obliquely incident to the front surface of the holographic sheet and are emitted in parallel in a direction perpendicular to the back surface of the holographic sheet.

The invention also provides a holographic aiming device, which comprises the light path system based on the micro-electromechanical light modulator.

Compared with the prior art, the invention also has the following advantages:

(1) the whole holographic plate is illuminated by adopting the micro-electromechanical light modulator through a laser scanning method without expanding beams, so that the area of a visible window can be greatly expanded without increasing laser power;

(2) in the micro-electro-mechanical light modulator, the uniformity problem does not exist in the whole window of laser scanning, and the uniformity is enhanced;

(3) the window can be enlarged without increasing the volume of the optical path.

Drawings

FIG. 1: the schematic diagram of the optical path system based on the micro-electromechanical light modulator in the embodiment 1;

FIG. 2: a schematic modulation diagram of the biaxial micro-electromechanical scanning galvanometer in the embodiment 1 on the light path;

FIG. 3: the laser input drive signals in embodiment 1 are of different duty cycles.

FIG. 4: the schematic diagram of the optical path system based on the micro-electromechanical light modulator in the embodiment 2;

FIG. 5: comparative light path system of example 1 and example 2;

FIG. 6: schematic diagram of the optical path system based on the micro-electromechanical light modulator in embodiment 3.

Detailed Description

The invention is further described below with reference to the following figures and specific examples.

Example 1

As shown in fig. 1, an optical path system based on a micro-electromechanical light modulator is sequentially provided with a semiconductor laser 1, an aspheric collimating lens 2, a biaxial micro-electromechanical scanning galvanometer 3, a curved reflecting mirror 4, a holographic lens 5 and a holographic sheet 6 along the direction of optical path propagation. The laser comprises a semiconductor laser 1, an aspheric collimating lens 2, a biaxial micro-electromechanical scanning galvanometer 3, a curved reflector 4 and a holographic lens 5, wherein the curved reflector and the holographic lens are distributed on the upper part and the lower part of the same side of a holographic sheet 6.

Wherein the wavelength of the semiconductor laser 1 is 637nm, and the divergence angle thereof is

The focal length d of the aspheric collimating lens 2 is 1mm, and the diameter of the collimated thin beam

In this embodiment, the dual-axis micro-electromechanical scanning galvanometer is a reflective spatial light modulator, which is actually a micro-mirror that can be electrically driven and can be moved and flipped, and can realize scanning in both the fast axis and the slow axis, and the scanning angles (2 θ shown in fig. 2) of the fast axis and the slow axis are 45 ° and 20 °, respectively.

In this embodiment, the curved surface reflector 4 has a function of collimating light beams, and the focal point position of the curved surface reflector coincides with the central point of the dual-axis micro-electromechanical scanning galvanometer 3.

In this embodiment, the holographic lens 5 is a bragg reflection grating, which has excellent angular selectivity for laser with a 637nm wavelength.

In this embodiment, the hologram 6 is a volume hologram grating made of a photothermal conversion glass material and recording a divisional hologram image.

As shown in fig. 3, the light brightness of the optical path system based on the micro-electromechanical light modulator in this embodiment can be adjusted by adjusting the output power of the laser (duty cycle adjustment) or adjusting the scanning period of the dual-axis micro-electromechanical scanning galvanometer. The duty cycle of graph a is smaller than graph B, so the output power in graph a is lower than the output power in graph B.

The working principle is as follows: the laser beamlets passing through the aspheric collimating lens 2 irradiate the central point of the reflecting mirror surface of the biaxial micro-electromechanical scanning galvanometer 3, are projected onto the subsequent curved reflecting mirror 4 at a fast two-dimensional scanning speed, then are incident to the holographic lens in the same direction for reflection, and finally are incident to the holographic plate at an oblique angle.

Example 2

As shown in fig. 4, an optical path system for a holographic aiming device based on a micro-electromechanical light modulator includes a semiconductor laser light source 1, an aspheric collimating lens 2, a biaxial micro-electromechanical scanning galvanometer 3, a collimating and reflecting concave mirror 4, a holographic lens 5 and a holographic sheet 6.

The difference between this embodiment and embodiment 1 is that the semiconductor laser 1, the aspheric collimating lens 2, the biaxial micro-electromechanical scanning galvanometer 3, the collimating and reflecting concave mirror 4, the holographic lens 5 and other optical elements are disposed at the lower part of the same side of the holographic plate, so that the lateral distance in the height of the holographic plate 6 can be reduced, and a wider field of view can be obtained, as shown in fig. 5, b is less than a.

In this embodiment, the wavelength of the semiconductor laser 1 is 637nm, and the divergence angle thereof is full

The focal length d of the aspheric collimating lens 2 is 1mm, and the diameter of the collimated thin beam

In this embodiment, the scanning angles of the fast axis and the slow axis of the dual-axis micro-electromechanical scanning galvanometer 3 are 45 ° and 30 °, respectively.

Example 3:

as shown in the figure, the light path system for the holographic aiming device based on the micro-electromechanical light modulator comprises a semiconductor laser light source 1, an aspheric collimating lens 2, a biaxial micro-electromechanical scanning galvanometer 3, a collimating lens 7, a holographic lens 5 and a holographic sheet 6.

The difference between this embodiment and embodiment 2 is that the collimating lens 7 is used instead of the collimating and reflecting concave mirror, which reduces the difficulty of the process.

The lithium battery with the same capacity is given to Etch EXPS3^TMThe sighting device can keep continuously lighting for 40-50H, but by adopting the three schemes, the sighting device can keep continuously lighting for 70-80H.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.