CN113606989B - Fresnel type laser emission lens cone and laser emitter - Google Patents

Abstract

The invention discloses a Fresnel type laser emission lens barrel and a laser emitter, wherein the Fresnel type laser emission lens barrel comprises a lens barrel, a laser pressing ring and a lens, the laser is positioned in the lens barrel and close to one end of the lens barrel and is pressed by the laser pressing ring, the lens is a Fresnel type lens and is fixed at the port of the other end of the lens barrel, one side of the Fresnel type lens is a plane, and the other side of the Fresnel type lens is an optical refraction surface. The laser emission lens cone generates a series of sub-beams which are finally synthesized into a light beam with approximate cylindrical light spots with equal diameters, and the problems that the light spots of common light beams at a short distance are too small and the light spots at a long distance are too large are effectively solved. Therefore, the problem that the target is difficult to hit in a short distance in laser engagement is solved, and the fidelity of weapon performance simulation in training is improved.

Description

Fresnel type laser emission lens cone and laser emitter

Technical Field

The invention relates to the technical field of laser emission, in particular to a Fresnel type laser emission lens cone and a laser emitter, which are applied to relevant laser combat confrontation in shooting training and belong to the fields related to weapon training, weapon simulation and emulation.

Background

The laser shot is commonly used in army training to simulate actual combat, both sides of the battle training are provided with laser transmitters on guns and cannons, when the laser transmitters perform bullet shooting actions, laser is emitted, each person or vehicle participating in training is worn or provided with a laser receiver, and when the laser irradiates on the receiver and is sensed by the receiver, the person or vehicle is judged to be shot. The fight training is carried out in a laser fight mode, and the fight effect on the spot can be well simulated.

The weapons (guns or cannons) in the training are all provided with laser transmitters, and the laser transmitters comprise laser transmitting lens barrels. The laser beam is emitted from the emission lens cone, the light beam forms a light spot at the distance of the target, and the receiver can receive the laser signal within the range of the light spot. Outside the spot, laser radiation is still possible, but the receiver is unresponsive due to the small intensity. The light spot is thus defined as the area of the light beam that can be sensed by the receiver over a cross-section at a distance.

The conventional laser beam transmission characteristics must have a certain divergence. This results in that the spot will become larger as the shot distance increases. When the distance is larger, the beam section is also larger, the total energy of the laser is limited, so that the laser illumination (or the intensity of each point) under a large-area section is reduced, and the intensity of the center of a light spot is larger than that of the periphery of the edge. At a long distance, only the illumination (or intensity) of the area in the central part of the light beam can make the receiver react, namely, the light spot is represented as a small area in the center of the light beam, and with the further increase of the distance, when the illumination (or intensity) of the central point is smaller than the sensitivity of the receiver, the receiver does not react, namely, the light spot cannot be detected, namely, the limit distance irradiated by the light beam is reached.

The light spot of the laser beam is characterized by being small and large, and then small and small. In the laser fighting training, if the light spot is large, the target is easy to hit, and if the light spot is small, the target is difficult to hit. Therefore, a laser beam with a constant spot diameter is urgently needed to be emitted for battle confrontation training.

Disclosure of Invention

In order to solve the problem of the small and large laser beam spots, the invention designs a Fresnel type laser emission lens barrel and a laser emitter, wherein one light beam is decomposed into a plurality of light beams, the plurality of light beams respectively form corresponding spots, the corresponding spots act on each distance in a near-far continuous mode, and the sizes of the spots are the same, so that approximately columnar light beams with the equal-diameter spots are formed in a fitting mode.

The invention provides a Fresnel type laser emission lens cone which comprises a lens cone, a laser pressing ring and a lens, wherein the laser is positioned in the lens cone, one end of the laser is close to the lens cone and is pressed by the laser pressing ring, the lens is a Fresnel type lens and is fixed at the port of the other end of the lens cone, one side of the Fresnel type lens is a plane, and the other side of the Fresnel type lens is an optical refraction surface.

Furthermore, the Fresnel lens comprises at least 3 sub-lenses which are in concentric ring structures, and each sub-lens is provided with an independent optical refraction surface.

Further, the sub-lens is configured to: and adjusting the widths of the rings of other layers except the innermost ring to make the heights of the maximum light spots generated by the optical refraction surfaces of the sub-lenses tend to be consistent.

Further, the maximum spot diameter of each sub-lens is the same.

Further, the radius of curvature of the optical refractive surface of each partial lens is set so as to satisfy the following condition:

wherein A1 is the incident angle of the laser emitted by the laser at the plane side of the Fresnel lens, A2 is the refraction angle of the laser in the Fresnel lens, nL is the optical refraction index of the Fresnel lens material, A3 is the incident angle of the light at the optical refraction surface of the sub-lens, A4 is the emergent angle of the light at the optical refraction surface of the sub-lens, A5 is the included angle between the emergent light after passing through the Fresnel lens and the horizontal direction, A6 is an included angle between the normal line of the optical refraction surface of the sub-lens and the optical axis, PH is the height of the maximum light spot generated by the sub-lens higher than the refraction point of the sub-lens, FH is the distance from the refraction point of the sub-lens to the maximum light spot in the horizontal direction, FT is the projection distance from the refraction point of the sub-lens to the optical axis, and RF is the curvature radius of the optical refraction surface of the sub-lens.

In a second aspect of the present invention, a laser transmitter is provided, which includes the fresnel laser transmitting lens barrel according to any one of the above technical solutions.

The lens of the lens cone for emitting the laser beam is designed into a Fresnel lens, so that the optical system is simple in structure. The lens has a structure with a multi-ring optical refraction surface, and has good realizability according to the processing technology of the Fresnel lens; the multi-ring structure in the Fresnel mirror decomposes a conventional single light beam into a plurality of sub-beams, the sub-beams have different action distances and have the same light spot size, and the sub-beams are finally synthesized into a light beam with approximate cylindrical light spots with the same diameter, so that the problems that the light spots of the common light beam at a short distance are too small and the light spots at a long distance are too large are effectively solved. Therefore, the problem that the target is difficult to hit in a short distance in laser engagement is solved, and the fidelity of weapon performance simulation in training is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a prior art laser combat confrontation training;

FIG. 2 is a schematic view of a laser-emitting lens barrel of a prior art combat laser transmitter;

FIG. 3 is a diagram of a common emitted laser beam transmission pattern;

FIG. 4 is a schematic diagram of the Fresnel type laser emission lens barrel according to the embodiment of the present invention;

FIG. 5 is a schematic view of a laser-emitting lens barrel employing a Fresnel lens in the embodiment of FIG. 4;

FIG. 6 is a schematic diagram of a multi-ring beam profile using Fresnel mirrors;

FIG. 7 is a schematic diagram illustrating the multi-ring beam combining effect in the embodiment of FIG. 6;

FIG. 8 is a schematic diagram of an equal-diameter light spot beam;

FIG. 9 is a schematic diagram illustrating the calculation of the optical path for transmitting a light beam formed on one of the optical surfaces of the Fresnel lens;

FIG. 10 is a schematic view of a calculation for forming beam transmission by a ring optical surface in the embodiment of FIG. 9;

FIG. 11 is an enlarged partial schematic view of FIG. 10;

description of reference numerals:

1-laser transmitter, 2-laser receiver, 3-rifle, 4-transmitting lens, 5-lens cone, 6-laser instrument clamping ring, 7-laser instrument, 8-fresnel type camera lens.

Detailed Description

In order to make the technical solutions of the present application better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort shall fall within the protection scope of the present application.

As shown in fig. 1, in the laser battle and confrontation training, all the confronters have laser transmitters 1 mounted on their weapons, which can emit laser light to simulate the shooting of bullets. Meanwhile, each person also wears the armed belt provided with the laser receiver 2, and the helmet is also provided with the laser receiver 2. When shooting in battle, the laser transmitter 1 emits a laser beam to the opposite side. If the gun is operated accurately, the laser beam can be irradiated on the opposite side, and the laser receiver 2 on the armed belt worn by the opposite side can sense the laser beam to send out a hit signal to inform the hit person of being injured or quitting the battle.

In such a conventional laser transmitter, a main component is a laser-emitting barrel, as shown in fig. 2. The laser emission lens barrel comprises an emission lens 4, a lens barrel 5, a laser pressing ring 6 and a laser 7. The laser 7 is arranged in the center of the lens cone and is pressed by the laser pressing ring 6 through threads. The emission lens 4 is cemented in the cylindrical surface of the other end of the lens barrel 5. Divergent laser emitted by the laser is converged by the transmitting lens 4, and the laser beam is compressed into a laser beam with a small divergence angle, is transmitted forwards and is emitted to a target.

In the laser engagement system, after the laser beam is irradiated on the opposite party, if the intensity of the laser is greater than the sensitivity of the receiver 2, the receiver can sense. Therefore, a region irradiated with a laser beam having an intensity greater than the sensitivity of the receiver is referred to as a spot. Laser radiation is generally present in the vicinity outside the spot, but the energy is already weak and cannot be sensed by the receiver. The two parties in the battle can subjectively feel the light spots, if the light spots are large, the opposite party is easy to hit, and otherwise, the opposite party is difficult to hit.

Generally, any one emitted laser beam has a certain divergence angle, and the smaller the divergence angle is, the more complicated the optical system is required to realize, and the more expensive the corresponding cost is. In a typical optical system, any complex lens can eventually be equivalent to an ideal single lens with a fixed single focal length.

In a common laser beam, the transmission process is as shown in fig. 3, and the laser beam leaves the emission lens barrel, because the spread range is small, the energy density is high, and the light spot gradually increases with the increase of the distance. When a certain distance is reached, as shown at L4, the spot reaches a maximum. At a distance after L4, although the beam is still enlarged, the laser energy is limited due to the enlarged area, so that the laser irradiation energy density is reduced, and the detectable region of the receiver becomes smaller, that is, the spot becomes smaller. The energy of the light spot is generally distributed in a strong center and weak edge on the cross section of the light beam, as shown in the right diagram of fig. 3. When the distance is further increased, the energy illumination in the beam section is continuously reduced, and the corresponding light spot is also reduced.

In fig. 3, the laser energy irradiation region is between two broken lines s 0. And connecting the edges of the light spots at each distance into a curve to form an envelope curve s of the edges of the light spots in the light beam. At distance L4, there is a maximum spot d4. The value of the distance L4 is mainly related to the focal length of the emission lens 4, and the shorter the focal length is, the more divergent the light beam is, the closer the corresponding maximum spot distance L4 is, and vice versa. The whole pattern of the laser beam light spot is a mode of being small and large and then being small, and the light spot size on one distance is the largest. Such a club-shaped spot beam may be represented as a thick-short type or a slim type due to the difference in optical system parameters. The laser beam emitted through the single-focal-length lens system exhibits such a stick-shaped beam characteristic.

In the laser fight confrontation, the light spots with different sizes are not beneficial to normal confrontation training, and the problems that the target is not hit easily by a short-distance small light spot (especially when the size of the light spot is smaller than the distance between two receivers, the light spot is hit between the two receivers, no receiver can sense the laser, and the target is not hit by wrong judgment) and the target is hit easily by a long-distance large light spot are easily caused.

In order to solve the problem that the distances of the light spots are different, the embodiment designs a fresnel-type laser emission lens barrel, which mainly has the function of decomposing an independent lens into a plurality of lenses, wherein each sub-lens has an annular optical surface structure and is integrated on one lens, that is, the lens has a multi-ring optical structure, as shown in fig. 4. The laser beam emitted by the lens barrel can form light spots with the same size in the distance.

Including lens cone, laser instrument clamping ring and camera lens, the laser instrument is located inside the lens cone, be close to the one end of lens cone, by the laser instrument clamping ring compresses tightly, its characterized in that, the camera lens is fresnel type camera lens, fixes the port department of the lens cone other end, the camera lens is provided with the laser instrument clamping ring, the laser instrument is provided with the fresnel type camera lens, the laser instrument clamping ring is provided with the fresnel type camera lens, the fresnel type camera lens is provided with the laser instrument clamping ring, the laser instrument clamping ring is provided with the laser instrument clamping ring, the laser instrument is provided with the fresnel type camera lens.

As shown in fig. 5, the fresnel-type laser emission lens barrel includes a fresnel-type lens 8, a lens barrel 5, a laser pressing ring 6, and a laser 7. The laser 7 is placed inside the barrel close to one end of the barrel 5 and is pressed by a laser pressing ring 6, optionally by a screw thread. The Fresnel lens 8 is located at the port of the other end of the lens barrel 5, one side of the Fresnel lens 8 is a plane, and the other side is an optical refraction surface. Divergent laser emitted by the laser 7 is refracted and converged by the Fresnel lens 8, and the laser beam is decomposed into a plurality of laser beams with different divergence angles, is synthesized and spread forwards, and is emitted out of the lens cone.

The Fresnel lens comprises at least 3 sub-lenses which are of concentric ring structures, each sub-lens is provided with an independent optical refraction surface, and the curvature radiuses of the optical refraction surfaces are different. As shown in fig. 4, the fresnel lens 8 includes a plurality of concentric ring structures, each ring structure is equivalent to a sub-lens having unique parameter characteristics, and the beam parameters generated by each sub-lens are different. Each annular substructure has an independent optical refracting surface, and the optical surface curvature radius of the central portion of the lens is r0, and r1 and r2 are arranged outwards in sequence. . . rn. . . The outermost ring has a radius of curvature rm.

In fig. 5, the rings produce different angles of scattering, for example, the light beam produced by the outer ring optical surface forms a larger divergence angle, and the annular optical surface in the central portion forms a smaller divergence angle light beam.

The light beam with larger divergence angle can form a spot with large size at near, but because the divergence degree of the light beam is large, the illumination intensity of the light beam is rapidly reduced along with the increase of the transmission distance, so that the maximum spot of the light beam can be obtained at near, and the spot is rapidly reduced along with the increase of the distance. The shape of the optical element is equivalent to the axial shortening of the optical beam in fig. 3, and is equivalent to a thick and short club shape.

As shown in fig. 6, a combined beam of multiple beams is formed by controlling the direction of divergence of the beams by the respective annular structure portions. The maximum light spots P1, P2, P3 and P3 are generated on the optical surface of each ring in sequence. . . Pn is calculated. . . Pm-1 and Pm. The light spots on the left side of the figure make up the light spot vacancy (the light spot is small, and the peripheral energy is insufficient) of the light beam on the right side at a short distance. By the combined action of the series of light beams, light beams with large light spots can be obtained at a short distance, the light spots are supplemented in the middle distance interval, and the corresponding light spot reduction gap is made up.

The split lens is thus set to: and adjusting the widths of the rings of other layers except the innermost ring to make the heights of the maximum light spots generated by the optical refraction surfaces of the sub-lenses tend to be consistent.

Specifically, the intensity of the sub-beams generated by each optical ring is adjusted by designing the width of the optical ring, and increasing the width can increase the energy of the beams passing through the corresponding ring. Thereby making P1, P2, P3. . . Pn. . . The heights of Pm-1 and Pm both tend to be the same. The envelope of the spot size formed by the resulting composite beam is therefore shown as G in fig. 7.

As shown in fig. 8, the light beam formed by the envelope G finally obtained exhibits a spot characteristic having substantially the same size in a long-area space of a far distance and a near distance, and the spot diameter thereof is substantially Φ D. The characteristic greatly makes up the problem that the spot of the common light beam becomes small in a short distance as shown in fig. 3, and the light beam has approximately the same spot in the conventional engagement distance, so that a more reasonable hit effect can be achieved.

In order to achieve the above-mentioned effect of combining light beams, the present embodiment first splits the light beam into a plurality of sub-beams, and irradiates the sub-beams to the corresponding positions. The respective ring-shaped optical structures should therefore be designed such that the beam direction through the ring impinges on a defined distance, forming a corresponding spot. As shown in fig. 9, according to the requirement of splitting and distributing the whole light beam, on a certain ring of the fresnel type mirror, the projection direction of the corresponding generated light beam is point P, and the structure parameters conform to the corresponding optical principle.

As shown in fig. 6, in the present embodiment, the light beam is designed to be preceded by L1, L2, L3, and L3. . . And m sub-beams are decomposed in the Lm distance, and each sub-beam generates the maximum light spots P1, P2, P3 and the like in the corresponding distance. . . Pm, these maximum spot sizes are all approximately the same.

In fig. 9, the light beams refracted by a certain ring of the fresnel mirror of the present embodiment will be projected to the point P at the distance Lp according to the general layout requirement, so as to generate corresponding sub-beams. The ring is subjected to parametric design of the optical structure by the following method.

In fig. 9, O is a light source point of the laser light. One side of the Fresnel lens is a plane, and the other side of the Fresnel lens is a multi-ring optical refraction surface structure. C is the central point of the Fresnel lens, the inclined short line at F in the figure is the annular optical surface generating refraction, the midpoint of the inclined short line is F, and the light emitted from the laser light source point O is refracted by F and then is emitted out to reach the point P. Point E is the intersection of the light ray from the light source O reaching point F and the optical surface on the left side of the lens. The point H is a point which is at the same height as the point F at the distance Lp.

The angle A1 is an included angle between an initial light ray OE and a normal of an optical surface on the left side of the lens; the angle A2 is the angle between the first refracted ray EF and the normal of the optical surface on the left side of the lens. Assuming that the optical refractive index of the fresnel-type mirror material is nL, since the refractive index of air is 1, according to the principle of light refraction, there is the following relationship:

Sin(A1)＝nL*sin(A2)

in fig. 10, ray EF is refracted by the annular surface, and the refracted ray is FP. Similarly, according to the refraction principle, the refraction angle has the following relationship:

Sin(A4)＝nL*sin(A3)

meanwhile, according to the position data of the point P, that is, PH is the difference between the point P and the point F, and FH is the horizontal distance from the point P to the point F, it can be known that:

Tan(A5)＝PH/FH

A6＝A4+A5

the intersection point of the normal of the point F and the main optical axis is R, the nature of the normal shows that the RF line segment is the curvature radius of the optical surface of the ring, and the height from the point F to the main optical axis is FT. Then there are:

Sin(A6)＝FT/RF

in fig. 11, horizontal auxiliary lines are drawn at points E and F, and from the misangle relationship in parallel lines, it can be seen that:

Af＝A2

A6＝Ac＝Af+A3

thus:

A6＝A2+A3

summarizing the above formulas to obtain a relational expression group:

wherein, A1 is the incident angle of the laser emitted by the laser on the plane side of the Fresnel lens, A2 is the refraction angle of the laser in the Fresnel lens, nL is the optical refraction index of the Fresnel lens material, A3 is the incident angle of the light on the optical refraction surface of the sub-lens, A4 is the emergent angle of the light on the optical refraction surface of the sub-lens, A5 is the included angle between the emergent light after passing through the Fresnel lens and the horizontal direction, A6 is an included angle between the normal line of the optical refraction surface of the sub-lens and the optical axis, PH is the height of the maximum light spot generated by the sub-lens higher than the refraction point of the sub-lens, FH is the distance from the refraction point of the sub-lens to the maximum light spot in the horizontal direction, FT is the projection distance from the refraction point of the sub-lens to the optical axis, and RF is the curvature radius of the optical refraction surface of the sub-lens.

The optical structure data of the lens of the present embodiment can be obtained by solving the curvature radius RF of the optical surface at each height FT by substituting the above equation according to the requirements for the range of action of the light beam, the distance, and the like, and the parameters such as the size of the lens, the material, and the like. The lens is used for transmitting the laser beam, and the beam effect of the spot with the same diameter can be obtained.

In fig. 7, the spot profile envelope G of the composite beam has a certain waviness, which is not an ideal straight line. The number of waves and the degree of undulation of the envelope are improved as the number of partial beams increases. When the number of the sub-beams is increased, the synthesized beam has a more exquisite fitting effect, the envelope curve can be more straight, and the light spot effect of the output beam is better. Therefore, when the Fresnel mirror is designed, the number of the annular optical surfaces is increased, so that the annular structure is miniaturized and refined, and the optimized columnar facula light beam can be obtained.

The multi-ring structure in the Fresnel mirror decomposes a conventional single light beam into a plurality of sub-beams, and the sub-beams have different operating distances and have the same spot size.

The series of sub-beams generated by the embodiment are finally synthesized into a light beam with approximate cylindrical light spots with equal diameters, so that the problems that the light spot of a common light beam at a short distance is too small and the light spot at a long distance is too large are effectively solved. Therefore, the problem that the target is difficult to hit in a short distance in laser engagement is solved, and the fidelity of weapon performance simulation in training is improved.

The invention also provides an embodiment of a laser transmitter, which comprises the Fresnel type laser transmitting lens barrel in any one of the technical schemes.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (4)

1. A Fresnel type laser emission lens cone comprises a lens cone, a laser pressing ring and a lens, wherein the laser is positioned inside the lens cone, is close to one end of the lens cone and is pressed by the laser pressing ring; the Fresnel lens comprises at least 3 sub-lenses which are of concentric ring structures, and each sub-lens is provided with an independent optical refraction surface; the radius of curvature of the optical refractive surface of each partial lens is set to satisfy the following condition:

wherein, A1 is the incident angle of the laser emitted by the laser on the plane side of the Fresnel lens, A2 is the refraction angle of the laser in the Fresnel lens, nL is the optical refraction index of the Fresnel lens material, A3 is the incident angle of the light on the optical refraction surface of the sub-lens, A4 is the emergent angle of the light on the optical refraction surface of the sub-lens, A5 is the included angle between the emergent light after passing through the Fresnel lens and the horizontal direction, A6 is an included angle between the normal of an optical refraction surface of the sub-lens and an optical axis, PH is the height of the maximum light spot generated by the sub-lens higher than the refraction point of the sub-lens, FH is the distance from the refraction point of the sub-lens to the maximum light spot in the horizontal direction, FT is the projection distance from the refraction point of the sub-lens to the optical axis, and RF is the curvature radius of the optical refraction surface of the sub-lens.

2. The fresnel-type laser-emitting lens barrel according to claim 1, wherein the sub-lens is provided: and adjusting the widths of the rings of other layers except the innermost ring to ensure that the heights of the maximum light spots generated by the optical refraction surfaces of the sub-lenses tend to be consistent.

3. The fresnel-type laser-emitting lens barrel according to claim 2, wherein the maximum spot diameter of each sub-lens is the same.

4. A laser transmitter comprising the fresnel type laser transmission lens barrel according to any one of claims 1 to 3.

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