阅读说明：本技术 一种适用于坡路面照明的led光学系统及其设计方法 (LED optical system suitable for slope illumination and design method thereof ) 是由 张云翠 潘妲 张鑫鹏 谢蓄芬 陈宇昂 樊敏菊 严舒涵 于 2020-12-10 设计创作，主要内容包括：本发明公开了一种适用于坡路面照明的LED光学系统,包括中心倾斜透镜(4)、矩形抛物面反射器(5),以及LED光源(6)；其中：所述矩形抛物面反射器5为上部开口且内表面(3)均为抛物面的中空方体结构,所述中心倾斜透镜(4)可拆卸的安装在所述矩形抛物面反射器(5)的上部开口处；所述中心倾斜透镜(4)为相对水平面倾斜角度为α且外形呈矩形的倾斜透镜。本发明基于倾斜透镜的原理,使LED面光源在坡路面上成像,使LED面光源在目标坡路面内形成均匀的矩形光斑,提高了坡路面的照度均匀性。实现LED光源发出的朗伯分布的光通过LED坡路面照明光学系统在目标坡路面的均匀照明。(The invention discloses an LED optical system suitable for slope illumination, which comprises a central inclined lens (4), a rectangular paraboloid reflector (5) and an LED light source (6); wherein: the rectangular paraboloid reflector (5) is of a hollow cube structure with an opening at the upper part and paraboloidal inner surfaces (3), and the central inclined lens (4) is detachably arranged at the opening at the upper part of the rectangular paraboloid reflector (5); the central inclined lens (4) is an inclined lens which has an inclination angle alpha relative to a horizontal plane and is rectangular in shape. Based on the principle of the inclined lens, the LED surface light source images on the slope surface, so that the LED surface light source forms uniform rectangular light spots in the target slope surface, and the illumination uniformity of the slope surface is improved. The uniform illumination of the Lambertian distributed light emitted by the LED light source on the target slope surface is realized through the LED slope surface illumination optical system.)

1. An LED optical system suitable for slope lighting, comprising a central tilted lens (4), a rectangular parabolic reflector (5), and an LED light source (6); wherein:

the rectangular paraboloid reflector (5) is a hollow square structure with an opening at the upper part and paraboloidal inner surfaces (3), and the central inclined lens (4) with the square outer contour is detachably arranged at the opening at the upper part of the rectangular paraboloid reflector (5) in a covering manner;

the LED light source (6) is positioned on the inner bottom surface of the rectangular paraboloid reflector (5) and is matched with the central inclined lens (4) and the rectangular paraboloid reflector (5) to form an image on a slope road surface.

2. The LED optical system suitable for slope illumination according to claim 1, wherein the central tilted lens (4) is connected with the upper port of the rectangular paraboloid reflector (5) through a lens barrel.

3. A design method of an LED optical system suitable for slope illumination is characterized by comprising the following steps:

step 1, designing the central inclined lens (4); carrying out optimization design by adopting a synchronous multi-curved surface design method suitable for the slope surface;

step 1.1, determining the entity of the central inclined lens (4);

step 1.11, defining any emergent light on the LED light source (6)Line is E₁E₂The light received by the light receiving surface of the slope corresponding to the light receiving surface is R₁R₂Center axis oo' and E₁E₂Is bisected vertically and E₁The marginal light rays emitted by the points are converged to an endpoint R of the light receiving surface of the slope road correspondingly₂A process of E₂The marginal light rays emitted by the points are converged to an endpoint R of the light receiving surface of the slope road correspondingly₁At least one of (1) and (b);

step 1.12, selecting said E₁A ray r emitted from the point₁Point P of refraction on the central axis oo₀As a starting point of a first chain of points on the upper surface (2) of the central tilted lens (4);

step 1.13, the ray r₁At the P₀Arbitrarily selecting a point P on the refracted ray of the point₁As a starting point of a second chain of points on the lower surface (1) of the central tilted lens (4);

step 1.14, assume the ray r₁At the P₁Refracted at point and directed to said end point R₂Determining the light ray r₁At the P₁Normal vector n at point₁The direction of (a);

step 1.15, according to the ray r₁Is obtained by the formula (15) of the propagation path calculation₁Point to the end point R₂Optical path Γ between₁；

Γ₁＝[E₁,P₀]+n₁[P₀,P₁]+[P₁,R₂] (15)

Step 1.16, E₂A ray r is emitted₂Passing point P₁Refracted light ray P₁R₁Has been determined, according to the vector form of the law of refraction:

wherein: n is the refractive index of the central tilted lens, N is the normal vector of the ray at point P:

then according to the formula:

x_i+1＝y_i+1tan(A_i+1) (18)

wherein: p_iHas a point coordinate of (x)_i,y_i),P_i+1Has a point coordinate of (x)_i+1,y_i+1) K is P_iThe slope of the tangent line of (a); a. the_i+1Is a point P_i+1The angle of inclination of (d);

the simultaneous formulas (17) and (18) obtain the iterative relationship between adjacent sampling points, and then the next point P of the upper surface (2) of the central inclined lens (4) can be determined₂And the normal n at that point₂(ii) a From the formula (19) ray r₂Can find a propagation path represented by E₂To R₁Optical path Γ between₂；

Γ₂＝[E₂,P₂]+n₂[P₂,P₁]+[P₁,R₁] (19)

Step 1.17, according to the principle that all light ray optical paths of the same image point corresponding to the same light source are the same, alternately applying the step 1.16 to respectively determine a point of a first point chain of the central inclined lens (4) and a point of a second point chain of the central inclined lens (4) until the first point chain is intersected with the second point chain;

step 1.18, the lens at the lower part of the central axis oo' in step 1.11 is still determined through step 1.11 to step 1.17; taking a connecting line of two intersection points of the upper surface (2) and the lower surface (1) of the central inclined lens (4) as a diagonal line with a rectangular diameter, and obtaining an entity of the central inclined lens (4) by using a grid construction mode;

step 1.2, calculating the focal length of the central inclined lens (4);

based on the imaging principle of the inclined lens, determining the focal length of the central inclined lens (4) according to the object distance and the image distance of the central inclined lens (4) and the target slope surface in the step 1.1;

step 2, designing the rectangular paraboloid reflector (5);

step 2.1, constructing a model of the rectangular paraboloid reflector (5);

step 2.11, taking the design of any two opposite inner surfaces of the rectangular paraboloid reflector (5) as an example, assuming that a parabola A is the contour line of the first inner surface and a parabola B is the contour line of the second inner surface;

parabola A around its focus F₁Rotate by theta in the counterclockwise direction_maxObtaining a first inner surface thereof; parabolic curve B around its focus F₂Also rotates by theta in the clockwise direction_maxObtaining a second inner surface; wherein, theta_maxIs the maximum emergence angle;

so that the focus F of the parabola A₁At the lower end of the parabola B, the focus F of the parabola B₂Falls at the lower endpoint of the parabola A;

the focal lengths in the x-axis direction and the y-axis direction are respectively expressed as:

f_2x＝a_x(1+sinθ_xmax) (20)

f_y＝a_2y(1+sinθ_ymax) (21)

wherein: a is_xIs the half width of the focal plane in the x-axis direction;

a_yis half-width in the y-axis direction;

f_x、f_yfocal lengths in the x and y directions, respectively;

θ_xmax、θ_ymaxthe maximum emergence angles in the directions of the x axis and the y axis respectively;

step 2.12, the parabolic segment F₁C and the parabolic segment F₂D, respectively translating along the direction vertical to the xoy plane to form two paraboloids which are symmetrical about the y axis; will be parabolic section F₁C and F₂D rotates 90 degrees anticlockwise around the y axis, and similarly, the D translates along the x axis to form two paraboloids which are symmetrical around the x axis, and the two groups of paraboloids are combined together to obtain a three-dimensional rectangular paraboloid reflector;

wherein, the axis a 'and the axis a are symmetric axes before and after the rotation of the parabola A in the step 1.31, respectively, and the axis B' and the axis B are the rotation of the parabola B in the step 1.31, respectivelyFront and rear symmetry axes, parabolic section F₂C and parabolic segment F₁D are parallel to the axes a and b respectively;

2.2, determining the caliber of the rectangular paraboloid reflector (5);

through the parabolic segment F in step 2.11₁C and the parabolic segment F₂D is the diameter of the light exit opening of the rectangular paraboloid reflector (5) after translation in the direction perpendicular to the xoy plane, respectively, and F₁F₂Is the width of the focal plane of the rectangular parabolic reflector (5);

according to the reversibility of light, the LED light source (6) is arranged on the focal plane of the rectangular paraboloid reflector (5), and the included angle theta between the emergent ray and the y axis is_iDefined as the angle of departure, when theta_i＜θ_maxWhen the light source is used, the light rays are reflected by the reflector and are emitted from the light outlet;

the exit half-width r can be expressed as:

wherein: r is half width of the emergent port;

l is the length of the rectangular paraboloid reflector (5) in the y-axis direction;

a is half width of an incident port;

f₂is the focal length;

as can be seen from the equation (22), the half width r of the entrance port increases as the length l of the rectangular parabolic reflector (5) in the y-axis direction increases;

step 2.3, determining the height of the rectangular paraboloid reflector (5);

the maximum height of the rectangular paraboloid reflector (5) ensures that the light rays irradiated by the LED light source (6) onto the reflecting surface of the rectangular paraboloid reflector (5) are larger than an epsilon angle;

and 2.4, cutting the exit port of the rectangular paraboloid reflector (5) along the inclined direction of the central inclined lens (4) to obtain the non-axisymmetric rectangular paraboloid reflector.

4. The design method of the LED optical system suitable for the slope illumination according to claim 3, wherein the inclination angle of the central inclined lens (4) ranges from 0 ° to 45 °.

5. A method of designing an LED optical system suitable for lighting a slope according to claim 3, wherein the inner surface (3) of the rectangular paraboloid reflector (5) is a light reflecting material suitable for the LED light source (6).

6. The design method of the LED optical system suitable for the slope illumination according to claim 3, wherein the LED light source (6) is a surface light source.

Technical Field

The invention relates to the technical field of LED illumination imaging optical system design, in particular to an LED optical system suitable for slope illumination and a design method thereof.

Background

Because the LED has the characteristics of small volume, long service life, high lighting effect, strong controllability and the like, the LED is widely applied to the field of illumination. With the maturity of high-power LED light source technology, the use requirements of LED light sources in road lighting are gradually increasing. Aiming at the traditional plane road, the technology of realizing rectangular light spot illumination by adopting an LED light source is mature. For special road surfaces, the traditional LED optical system cannot achieve good lighting effect.

As shown in fig. 6 to 8, the light intensity distribution of most of the LED light sources conforms to lambertian distribution, and if the light is not distributed, a circular light spot with uneven illumination is irradiated on the target surface, which cannot meet the requirements of road illumination, especially special road illumination. At present, most of the existing design methods are free-form surface lens design methods, and also have catadioptric hybrid lens or total reflection lens design methods. The existing optical system design aiming at special road illumination adopts the special-shaped groove lens to design the optical system on the basis of the existing free-form surface collimating lens, can meet the requirements of different curves, and solves the problem that the traditional street lamp cannot effectively illuminate the curves. But the design of an optical system aiming at the slope surface is not reported. The slope road surface is a common road condition in urban and rural roads. Especially in mountain cities, some slope roads have a slope of at least 15 ° or even higher, which is a dangerous section of a road, especially a motor vehicle driven road. In slope road surface illumination, the traditional illumination lamp has the phenomena of uneven illumination of an illuminated road, glare caused by too much light received by a driver in an uphill process and the like, and becomes a hidden danger of road traffic safety. How to design a slope road surface illumination optical system applicable to urban and rural roads is a problem which needs to be solved urgently in the field.

Disclosure of Invention

The invention provides an LED optical system suitable for slope illumination, aiming at the phenomena that the illumination of an existing street lamp on a slope is uneven, a driver receives excessive light rays to cause glare and the like in the process of ascending, and the like, of an existing street lamp on the slope, wherein the LED optical system comprises a central inclined lens, a rectangular paraboloid reflector and an LED light source; wherein:

the rectangular paraboloid reflector is a hollow square structure with an opening at the upper part and paraboloidal inner surfaces, and the central inclined lens with the square outer contour is detachably arranged at the opening at the upper part of the rectangular paraboloid reflector in a covering mode. The LED light source is positioned on the inner bottom surface of the rectangular paraboloid reflector and is matched with the central inclined lens and the rectangular paraboloid reflector to form an image on a slope road surface.

Preferably, the central inclined lens is connected with the upper port of the rectangular paraboloid reflector through a lens barrel.

A design method of an LED optical system suitable for slope illumination comprises the following steps:

step 1, designing the central inclined lens; carrying out optimization design by adopting a synchronous multi-curved surface design method suitable for the slope surface;

step 1.1, determining the entity of the central inclined lens;

step 1.11, defining any emergent ray on the LED light source as E₁E₂The light received by the light receiving surface of the slope corresponding to the light receiving surface is R₁R₂Center axis oo' and E₁E₂Is bisected vertically and E₁The marginal light rays emitted by the points are converged to an endpoint R of the light receiving surface of the slope road correspondingly₂A process of E₂The marginal light rays emitted by the points are converged to an endpoint R of the light receiving surface of the slope road correspondingly₁At least one of (1) and (b);

step 1.12, selecting said E₁A ray r emitted from the point₁Point P of refraction on the central axis oo₀As a starting point of a first chain of points on the upper surface of the central tilted lens;

step 1.13, the ray r₁At the P₀Arbitrarily selecting a point P on the refracted ray of the point₁As a starting point of a second chain of points on the lower surface of the central tilted lens;

step 1.14, assume the ray r₁At the P₁Refracted at point and directed to said end point R₂Determining the light ray r₁At the P₁Normal vector n at point₁The direction of (a);

step 1.15, according to the ray r₁Is calculated by the propagation path calculation formula of₁Point to the end point R₂Optical path Γ between₁；

Γ₁＝[E₁,P₀]+n₁[P₀,P₁]+[P₁,R₂] (15)

Step 1.16, E₂A ray r is emitted₂Passing point P₁Refracted light ray P₁R₁Has been determined, according to the vector form of the law of refraction:

wherein: n is the refractive index of the central tilted lens, N is the normal vector of the ray at point P:

then according to the formula:

x_i+1＝y_i+1 tan(A_i+1) (18)

wherein: p_iHas a point coordinate of (x)_i,y_i),P_i+1Has a point coordinate of (x)_i+1,y_i+1) K is P_iThe slope of the tangent line of (a); a. the_i+1Is a point P_i+1The angle of inclination of (d);

obtaining the iterative relationship between adjacent sampling points by the simultaneous formulas (17) and (18), namely determining the next point P of the upper surface of the central inclined lens₂And the normal n at that point₂(ii) a From the formula (19) ray r₂Can find a propagation path represented by E₂To R₁Optical path Γ between₂；

Γ₂＝[E₂,P₂]+n₂[P₂,P₁]+[P₁,R₁] (19)

Step 1.17, according to the principle that all light ray optical paths of the same image point corresponding to the same light source are the same, alternately applying the step 1.16 to respectively determine a point of a first point chain of the center inclined lens and a point of a second point chain of the center inclined lens until the first point chain is intersected with the second point chain;

step 1.18, the lens at the lower part of the central axis oo' in step 1.11 is still determined through step 1.11 to step 1.17; taking a connection line of two intersection points of the upper surface and the lower surface of the central inclined lens as a diagonal line with a rectangular diameter, and obtaining an entity of the central inclined lens by using a form of constructing a grid;

step 1.2, calculating the focal length of the central inclined lens;

based on the imaging principle of the inclined lens, determining the focal length of the central inclined lens according to the object distance and the image distance of the central inclined lens and the target slope surface in the step 1.1;

step 2, designing the rectangular paraboloid reflector;

step 2.1, constructing the rectangular paraboloid reflector model;

step 2.11, taking the design of any two opposite inner surfaces of the rectangular paraboloid reflector as an example, assuming that a parabola A is the contour line of the first inner surface and a parabola B is the contour line of the second inner surface;

parabola A around its focus F₁Rotate by theta in the counterclockwise direction_maxObtaining a first inner surface thereof; parabolic curve B around its focus F₂Also rotates by theta in the clockwise direction_maxObtaining a second inner surface; wherein, theta_maxIs the maximum emergence angle;

so that the focus F of the parabola A₁At the lower end of the parabola B, the focus F of the parabola B₂Falls at the lower endpoint of the parabola A;

the focal lengths in the x-axis direction and the y-axis direction are respectively expressed as:

f_2x＝a_x(1+sinθ_xmax) (20)

f_y＝a_2y(1+sinθ_ymax) (21)

wherein: a is_xIs the half width of the focal plane in the x-axis direction;

a_yis half-width in the y-axis direction;

f_x、f_yfocal lengths in the x and y directions, respectively;

θ_xmax、θ_ymaxthe maximum emergence angles in the directions of the x axis and the y axis respectively;

step 2.12, the parabolic segment F₁C and the parabolic segment F₂D, respectively translating along the direction vertical to the xoy plane to form two paraboloids which are symmetrical about the y axis; will be parabolic section F₁C and F₂D rotates 90 degrees anticlockwise around the y axis, and similarly, the D translates along the x axis to form two paraboloids which are symmetrical around the x axis, and the two groups of paraboloids are combined together to obtain a three-dimensional rectangular paraboloid reflector;

wherein the axis a' and the axis a are respectively the throws described in step 1.31The axis of symmetry before and after the rotation of the object line A, the axis B' and the axis B are the axis of symmetry before and after the rotation of the parabola line B in the step 1.31, respectively, and the parabola section F₂C and parabolic segment F₁D are parallel to the axes a and b respectively;

2.2, determining the caliber of the rectangular paraboloid reflector;

through the parabolic segment F in step 2.11₁C and the parabolic segment F₂D is the diameter of the light exit opening of the rectangular paraboloid reflector after being respectively translated in the direction perpendicular to the xoy plane, and F₁F₂Is the width of the focal plane of the rectangular parabolic reflector;

according to the reversibility of light, the LED light source is arranged on the focal plane of the rectangular paraboloid reflector, and the included angle theta between the emergent ray and the y axis is_iDefined as the angle of departure, when theta_i＜θ_maxWhen the light source is used, the light rays are reflected by the reflector and are emitted from the light outlet;

the exit half-width r can be expressed as:

wherein: r is half width of the emergent port;

l is the length of the rectangular paraboloid reflector in the y-axis direction;

a is half width of an incident port;

f₂is the focal length;

as can be seen from equation (22), the half width r of the entrance port increases as the length l of the rectangular parabolic reflector in the y-axis direction increases;

step 2.3, determining the height of the rectangular paraboloid reflector;

the maximum height of the rectangular paraboloid reflector ensures that the light rays irradiated by the LED light source on the reflecting surface of the rectangular paraboloid reflector are larger than an epsilon angle;

and 2.4, cutting the emergent port of the rectangular paraboloid reflector along the inclined direction of the central inclined lens to obtain the non-axisymmetric rectangular paraboloid reflector.

Preferably, the central inclined lens has an inclination angle ranging from 0 ° to 45 °.

Preferably, the inner surface (3) of the rectangular parabolic reflector (5) is of a light reflective material suitable for the LED light source (6).

Preferably, the LED light source (6) is a surface light source.

The invention has the following beneficial effects: based on the principle of an inclined lens, an LED surface light source forms an inclined image on a slope surface, the LED slope surface lighting optical system is composed of a central inclined lens and a rectangular paraboloid reflector, the central inclined lens is designed by adopting a synchronous free multi-curved surface method suitable for the slope surface, the rectangular paraboloid reflector is designed by adopting an edge light principle, and therefore the obtained LED slope surface lighting optical system can enable the LED surface light source to form uniform rectangular light spots in a target slope surface, and the illumination uniformity of the slope surface is improved. The uniform illumination of the Lambertian distributed light emitted by the LED light source on the target slope surface is realized through the LED slope surface illumination optical system.

Drawings

Fig. 1 is a perspective schematic view of a three-dimensional structure of an LED optical system suitable for illumination of a slope.

Fig. 2 is a schematic top view of the LED optical system for illumination of a slope road according to the present invention.

Fig. 3 is a schematic side view of an LED optical system suitable for illumination of a slope.

Fig. 4 is a schematic front view of an LED optical system suitable for illumination on a slope.

Fig. 5 is a schematic cross-sectional structural diagram of an LED optical system suitable for illumination on a slope road according to the present invention.

Fig. 6 is a graph of illuminance of a conventional lens in the prior art on a horizontal road surface.

Fig. 7 is a graph of illuminance of a conventional lens on a slope road surface in the prior art.

Fig. 8 is a graph of illuminance formed on a slope road surface by the inclined lens of the LED optical system suitable for slope road illumination according to the present invention.

Fig. 9 is a light distribution curve along a road direction of the LED optical system suitable for illumination of a slope road according to the present invention.

Fig. 10 is a light distribution curve of the LED optical system suitable for illumination on a slope road in a direction perpendicular to a road according to the present invention.

Fig. 11 is a schematic diagram of a conventional lens in the prior art.

FIG. 12 is a schematic diagram of a tilted lens of an LED optical system for illumination of a slope according to the present invention.

Fig. 13 is a schematic front view of a rectangular paraboloid reflector of an LED optical system suitable for illumination of a slope according to the present invention.

FIG. 14 is a schematic side view of a rectangular parabolic reflector of an LED optical system for hill lighting according to the present invention.

FIG. 15 is a schematic diagram of a solid-synchronous multi-curved-surface design of a tilted lens of an LED optical system suitable for illumination on a slope road.

Fig. 16 is a schematic diagram of the design of the longitudinal section structure of the rectangular parabolic reflector of the LED optical system for illumination on a slope road according to the present invention.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

Example (b):

as shown in fig. 1 to 5, an LED optical system suitable for illumination of a slope road includes a central tilted lens 4, a rectangular paraboloid reflector 5, and an LED light source 6; wherein:

the rectangular paraboloid reflector 5 is a hollow cube structure with an opening at the upper part and parabolic inner surfaces 3, and the central inclined lens 4 is detachably arranged at the opening at the upper part of the rectangular paraboloid reflector 5; the inner surface 3 of the rectangular paraboloid reflector 5 is a reflecting surface. The outer contour of the central inclined lens 4 is rectangular, so that the inclined angle of the LED light source imaging can be the same as the inclined angle of the slope surface. Due to the limitation of the inclination angle of the lens, the invention is suitable for the inclined slope road surface of 0-45 degrees.

The LED light source 6 is located on the inner bottom surface of the rectangular parabolic reflector 5. The central inclined lens 4 is connected with the upper port of the rectangular paraboloid reflector 5 through a lens barrel. As shown in fig. 8 to 10, the rectangular paraboloid reflector 5 of the present invention is used for imaging the light of the LED light source 6 on the target slope, so that the light emitting angle of the LED light source is smaller than the critical angle θ_bThe central light of the light source realizes uniform rectangular light spots on a target slope road surface; the lower port of the rectangular paraboloid reflector 5 is a rectangular opening parallel to the horizontal plane, and the upper port is an inclined rectangular opening with the same inclination angle as the central inclined lens 4 and the same outer contour size. The LED light source is used for converging the light rays with the light-emitting angle larger than theta of the LED light source into a target slope.

A design method of an LED optical system suitable for slope illumination comprises the following steps:

step 1, designing the central inclined lens 4; carrying out optimization design by adopting a synchronous multi-curved surface design method suitable for the slope surface;

the central inclined lens is used for ensuring that the light-emitting angle of the LED light source is less than the critical angle theta_bThe central light is subjected to light distribution design, so that uniform rectangular illumination light spots are formed in a target slope; the rectangular paraboloid reflector is used for leading the emergent light angle of the LED light source to be larger than the critical angle theta_bThe light rays with the angle less than 90 degrees are subjected to light distribution design, so that the light emitting angle of the LED light source is larger than the critical angle theta_bThe light rays smaller than 90 degrees are converged on the target slope road surface.

As shown in FIGS. 13-14, which are schematic diagrams of LED slope illumination optical system design, first a critical angle θ is defined_bThe LED light source selected in the design is a single-sided light emitting diode area light source. In order to divide whether the LED light source passes through the inner surface of the rectangular paraboloid reflector or not, according to the light intensity distribution principle of the Lambert light source, the following light intensity distribution formula is satisfied:

I＝I₀·cosθ (14)

as can be seen from equation (14), followingThe light intensity is decreased progressively as the light emitting angle of the LED light source is increased, and the decreasing rule meets the cosine law. Therefore, when the angle θ is larger than 60 °, the light intensity decreases rapidly, and the influence on the uniformity of the illuminance on the target inclined surface is very small. Therefore, the critical angle θ_bMost suitably equal to 60 deg.. As shown in FIGS. 13 to 14, [ theta ] is_bIs the angle of demarcation of the refracted and reflected rays of a rectangular parabolic reflector.

When the light-emitting angle of the LED light source is between 0 DEG and epsilon_bWhen the light beam is within the range, the light beam directly irradiates the lower surface of the central inclined lens to generate primary refraction, the emergent light beam irradiates the upper surface of the central inclined lens to generate secondary refraction, and finally irradiates the range of a target area to form uniform rectangular light spots; when the light-emitting angle of the LED light source is in epsilon_bWhen the light beam is within the range of 90 degrees, the light beam obliquely irradiates the rectangular paraboloid reflector, the light beam is reflected on the inner surface of the rectangular paraboloid reflector, the reflected light beam irradiates the central inclined lens, and the reflected light beam is refracted twice on the lower upper surface of the central inclined lens and finally irradiates the target area range. Therefore, the light rays directly irradiating the target area range through the central inclined lens are superposed with the light rays irradiating the target area range through the rectangular paraboloid reflector and the central inclined lens respectively, and uniform rectangular light spots can be formed on the target slope surface.

As shown in fig. 15, the steps of designing the center tilt lens 4 are:

step 1.1, determining the entity of the central inclined lens 4;

step 1.11, defining any emergent ray on the LED light source 6 as E₁E₂The light received by the light receiving surface of the slope corresponding to the light receiving surface is R₁R₂Center axis oo' and E₁E₂Is bisected vertically and E₁The marginal light rays emitted by the points are converged to an endpoint R of the light receiving surface of the slope road correspondingly₂A process of E₂The marginal light rays emitted by the points are converged to an endpoint R of the light receiving surface of the slope road correspondingly₁At least one of (1) and (b);

step 1.12, selecting said E₁A ray r emitted from the point₁Point P of refraction on the central axis oo₀As the center tilt lens 4The upper surface 2 of (2) is the starting point of the first chain of points;

step 1.13, the ray r₁At the P₀Arbitrarily selecting a point P on the refracted ray of the point₁As a starting point of a second chain of points on the lower surface 1 of the central tilted lens 4;

step 1.14, assume the ray r₁At the P₁Refracted at point and directed to said end point R₂Determining the light ray r₁At the P₁Normal vector n at point₁The direction of (a);

step 1.15, according to the ray r₁Is obtained by the formula (15) of the propagation path calculation₁Point to the end point R₂Optical path Γ between₁；

Γ₁＝[E₁,P₀]+n₁[P₀,P₁]+[P₁,R₂] (15)

Step 1.16, E₂A ray r is emitted₂Passing point P₁Refracted light ray P₁R₁Has been determined, according to the vector form of the law of refraction, where n is the index of refraction of the central tilted lens,is the normal vector of the ray at point P:

then according to the formula:

x_i+1＝y_i+1 tan(A_i+1) (18)

wherein P is_iHas a point coordinate of (x)_i,y_i),P_i+1Has a point coordinate of (x)_i+1,y_i+1) K is P_iThe slope of the tangent of (a). Wherein A is_i+1Is a point P_i+1The angle of inclination of (a).

The simultaneous formulas (17) and (18) obtain the iterative relationship between adjacent sampling points, namely the next point P of the upper surface (2) of the central inclined lens 4 can be determined₂And the normal n at that point₂(ii) a From the formula (19) ray r₂Can find a propagation path represented by E₂To R₁Optical path Γ between₂；

Γ₂＝[E₂,P₂]+n[P₂,P₁]+[P₁,R₁] (19)

Step 1.17, according to the principle that all light ray optical paths of the same image point corresponding to the same light source are the same, alternately applying the step 1.16 to respectively determine a point of a first point chain of the central inclined lens 4 and a point of a second point chain of the central inclined lens 4 until the first point chain and the second point chain are intersected;

step 1.18, the lens at the lower part of the central axis oo' in step 1.11 is still determined through step 1.11 to step 1.17; taking a connection line of two intersection points of the upper surface 2 and the lower surface 1 of the central inclined lens 4 as a diagonal line with a diameter of a rectangle, and obtaining an entity of the central inclined lens 4 by using a form of constructing a grid;

step 1.2, calculating the focal length of the central inclined lens 4;

based on the imaging principle of the inclined lens, determining the focal length of the central inclined lens according to the object distance and the image distance between the central inclined lens 4 and the target slope surface in the step 1.1;

as shown in figure 16 of the drawings,

step 2, designing the rectangular paraboloid reflector 5;

step 2.1, constructing a model of the rectangular paraboloid reflector 5;

step 2.11, taking the design of any two opposite inner surfaces of the rectangular paraboloid reflector 5 as an example, assuming that a parabola a is the contour line of the first inner surface and a parabola B is the contour line of the second inner surface;

parabola A around its focus F₁Rotate by theta in the counterclockwise direction_maxObtaining a first inner surface thereof; parabolic curve BAround its focal point F₂Also rotates by theta in the clockwise direction_maxObtaining a second inner surface; wherein, theta_maxIs the maximum emergence angle;

so that the focus F of the parabola A₁At the lower end of the parabola B, the focus F of the parabola B₂Falls at the lower endpoint of the parabola A;

the focal lengths in the x-axis direction and the y-axis direction are respectively expressed as:

f_2x＝a_x(1+sinθ_xmax) (20)

f_y＝a_2y(1+sinθ_ymax) (21)

wherein: a is_xIs the half width of the focal plane in the x-axis direction;

a_yis half-width in the y-axis direction;

f_x、f_yfocal lengths in the x and y directions, respectively;

θ_xmax、θ_ymaxthe maximum emergence angles in the directions of the x axis and the y axis respectively;

step 2.12, the parabolic segment F₁C and the parabolic segment F₂D, respectively translating along the direction vertical to the xoy plane to form two paraboloids which are symmetrical about the y axis; will be parabolic section F₁C and F₂D rotates 90 degrees anticlockwise around the y axis, and similarly, the D translates along the x axis to form two paraboloids which are symmetrical around the x axis, and the two groups of paraboloids are combined together to obtain a three-dimensional rectangular paraboloid reflector;

wherein, the axis a 'and the axis a are respectively the symmetry axes before and after the rotation of the parabola A in the step 1.31, the axis B' and the axis B are respectively the symmetry axes before and after the rotation of the parabola B in the step 1.31, and the parabola section F₂C and parabolic segment F₁D are parallel to the axes a and b respectively;

2.2, determining the caliber of the rectangular paraboloid reflector 5;

through the parabolic segment F in step 2.11₁C and the parabolic segment F₂D is the diameter of the light exit opening of the rectangular paraboloid of said rectangular paraboloid reflector 5, F after translation respectively in the direction perpendicular to the xoy plane₁F₂Is the width of the focal plane of the rectangular parabolic reflector 5;

according to the reversibility of light, the LED light source 6 is arranged on the focal plane of the rectangular paraboloid reflector 5, and the included angle theta between the emergent ray and the y axis_iDefined as the angle of departure, when theta_i＜θ_maxWhen the light source is used, the light rays are reflected by the reflector and are emitted from the light outlet;

the exit half-width r can be expressed as:

wherein: r is half width of the emergent port;

l is the length of the rectangular parabolic reflector 5 in the y-axis direction;

a is half width of an incident port;

f₂is the focal length;

as can be seen from equation (22), the half-width r of the entrance port increases as the length l of the rectangular parabolic reflector 5 in the y-axis direction increases;

step 2.3, determining the height of the rectangular paraboloid reflector 5;

the maximum height of the rectangular paraboloid reflector 5 ensures that the light rays irradiated by the LED light source 6 onto the reflecting surface of the rectangular paraboloid reflector 5 are greater than an angle alpha;

and 2.4, cutting the emergent port of the rectangular paraboloid reflector 5 along the inclined direction of the central inclined lens to obtain the non-axisymmetric rectangular paraboloid reflector.

Wherein: the central tilted lens 4 is a light transmissive material suitable for the LED light source 6. The rectangular parabolic reflector 5 is a light reflecting material suitable for the LED light source 6. The LED light source 6 is a surface light source.

The principle of tilting the lens is as follows:

as shown in fig. 11, a main optical axis of a conventional lens is vertically and equally divided by an object AB, a lens MN and an image a ' B ', the object and the image are divided at two sides of the lens and are parallel to the lens, and a light ray emitted from a point a on the object is refracted by the lens MN and converged to an image point a '; the light emitted from the point B on the object is refracted by the lens MN and is converged to the image point B', and the optical paths of all the light are the same.

In FIG. 11, AB denotes the LED light source 6, MN denotes the lens, A ' B ' denotes the object plane, L denotes the object distance, L ' denotes the image distance, f₁Indicating the focal length of the lens. The imaging formula of the lens in the figure satisfies:

as shown in fig. 12, in order to enable the LED light source 6 to form uniform light spots on a slope with an inclination angle β, on the basis of the conventional lens light path diagram, the lens is rotated by an angle α, so that the main optical axis is also rotated by an angle α, the emergent light of the light source point a is refracted by the central inclined lens MN, and the emergent light converges to a point a' on the target plane, and all light optical paths are the same; emergent rays at the point B of the light source are refracted through the inclined lens MN, all the emergent rays are converged to a point B ' on the target plane, all the ray paths are the same, but the ray paths from A to A ' are different from the ray paths from B to B '. For finite objects, the imaging relationship of the tilted lens still satisfies equation (1).

In fig. 12, AB denotes a light source, MN denotes a tilt lens, a 'B' denotes a target plane, xoy denotes a coordinate axis of the lens before rotation, x 'oy' denotes a coordinate axis of the tilt lens, α denotes a rotation angle of the coordinate axis from xoy to x 'oy', and β denotes a tilt angle of the target plane; l is_ARepresents the object distance from point a to the tilt lens MN; l is_A'represents an image distance from the point a' to the tilt lens MN; l is_BRepresents the object distance from point B to the tilt lens MN; l is_B'represents an image distance from the point B' to the tilt lens MN; f. of₁Indicating the focal length of the tilted lens.

Before the lens is rotated, let the coordinate of the point A of the light source be (x) with respect to the coordinate axis xoy_A,y_A) The coordinate of the point B of the light source is (x)_B,y_B) The coordinate of the point A' of the target plane is (x)_A',y_A') and the coordinates of the point B' of the target plane are (x)_B',y_B'). The relationship among the object distance, the image distance and the focal distance of the point A and the point B of the light source are respectivelyComprises the following steps:

the lens and the coordinate axis xoy are rotated anticlockwise by an angle alpha to obtain a new coordinate axis x 'oy' and the focal length f of the lens₁And is not changed. The coordinates of the points A and B of the light source relative to the coordinate axis x 'oy' areThe expression is as follows:

the coordinates of the points A 'and B' of the target plane with respect to the coordinate axis x 'oy' areThe expression is as follows:

after the lens and the coordinate axis xoy rotate counterclockwise by an angle alpha, the coordinates of the light source point A, the point B, the target plane point A 'and the target plane point B' with respect to the coordinate axis xoy are respectivelyWatch with watchThe expression is as follows:

at this time, the following formula (2) - (11) can be obtained:

wherein the content of the first and second substances,the relationship between α and β can be obtained by substituting the equations (10) and (11) into the equation (12). Due to the limitation of the inclination angle of the lens, the method is suitable for the inclined slope road surface of 0-45 degrees.

The principle of the traditional lens is broken through, the lens is rotated into a central inclined lens forming an alpha angle with the horizontal plane, and then uniform rectangular light spots can be formed on the inclined slope surface. As shown in fig. 8.

The installation mode of the invention is as follows:

an LED optical system suitable for slope road illumination comprises a central inclined lens 4, a rectangular paraboloid reflector 5 and an LED light source 6; wherein:

the rectangular paraboloid reflector 5 is a hollow cube structure with an opening at the upper part and parabolic inner surfaces 3, and the central inclined lens 4 is detachably arranged on the lens barrel at the opening at the upper part of the rectangular paraboloid reflector 5; the inner surface 3 of the rectangular paraboloid reflector 5 is a reflecting surface.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.