CN103185286B - Even optical element and light-source system - Google Patents

Abstract

The invention discloses a kind of even optical element and light-source system, this even optical element is used for the incident ray shaping produced light source, even optical element comprises a free form surface, this free form surface by be positioned at light source central axis direction precalculated position one standard surf deform obtain, except central axis direction, along from this central shaft to the direction of the side direction of central shaft, the difference of the incident angle of incident ray on free form surface and the incident angle of this incident ray on standard curved surface keeps jack per line, the absolute value monotonic increase of the difference of the incident angle of incident ray on free form surface and the incident angle of this incident ray on standard curved surface, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface and the incident angle of this incident ray on standard curved surface successively decreases, with make the emergent ray of free form surface predetermined solid angle internal ratio incident ray have evenly light distribution.The problem that the light utilization efficiency that the present invention can avoid crosstalk etc. to cause reduces.

Description

Even optical element and light-source system

Technical field

The present invention relates to illumination and display field, particularly relate to a kind of even optical element and light-source system.

Background technology

The light source such as semiconductor laser, LED is widely used in the fields such as illumination, projection, optics phototypesetting, optical storage.In such applications, need by light source on objective plane as far as possible formation certain size, there is the Illumination Distribution of regular shape, as rectangular uniform distribution.

And the Light distribation of conventional light source is all not ideal enough, such as the Light distribation of semiconductor laser on cross section is generally oval Gauss, as shown in Figure 1, the Light distribation of light emitting diode on cross section is generally bell Light distribation on its major axis and minor axis, and the Light distribation on cross section as shown in Figure 2.

There is document proposition based on the method (paper Laser Beam Shaping Techniques) of fly's-eye lens.Be illustrated in fig. 3 shown below: be of a size of the parallel beam incident of D to the fly's-eye lens pair comprising two fly's-eye lenses, light beam is divided into several beamlets to the lenticule 11,12 utilized wherein by fly's-eye lens, each beamlet a pair lenticule 11,12 processes respectively, formation rectangular light distributes, and because beamlet area is very little, the Light distribation in this rectangle is close to even.Last again through the normal lens 13 that a focal length is F, beamlet superposes on objective plane, thus obtains uniform illumination in the rectangle being of a size of S.This method is very high to requirement on machining accuracy, and the light between lenticule 11,12 has certain crosstalk, cause on objective plane and occur secondary lobe hot spot, the convergence part branch between each lenticule in addition in each fly's-eye lens affects the outgoing of light, and these all cause the reduction of light utilization efficiency.

Summary of the invention

The technical problem that the present invention mainly solves is to provide a kind of even optical element and light-source system, the problem that the light utilization efficiency that above-mentioned crosstalk etc. can be avoided to cause reduces.

The invention provides a kind of even optical element, for the incident ray shaping produced light source, this incident ray forms the first hot spot in the plane of the central axis with this light source, the Illumination Distribution of the first hot spot weakens by outside mediad, it is characterized in that, even optical element comprises a free form surface, this free form surface by be positioned at light source central axis direction precalculated position one standard surf deform obtain, this standard curved surface is the curved surface that can be shaped as directional light to incident ray;

Except central axis direction, along from this central shaft to the direction of the side direction of central shaft, the difference of the incident angle of incident ray on free form surface and the incident angle of this incident ray on standard curved surface keeps jack per line, the absolute value monotonic increase of the difference of the incident angle of incident ray on free form surface and the incident angle of this incident ray on standard curved surface, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface and the incident angle of this incident ray on standard curved surface successively decreases, with make the emergent ray of free form surface predetermined solid angle internal ratio incident ray have evenly light distribution.

The present invention also provides a kind of even optical element, for the incident ray shaping produced light source, this incident ray forms the first hot spot in the plane of the central axis with this light source, the Illumination Distribution of the first hot spot weakens by outside mediad, it is characterized in that, even optical element comprises a free form surface, this free form surface by be positioned at light source central axis direction precalculated position one standard surf deform obtain, this standard curved surface is the curved surface that incident ray can be converged at the central point of presumptive area;

Except central axis direction, along from this central shaft to the direction of the side direction of central shaft, the difference of the incident angle of incident ray on free form surface and the incident angle of this incident ray on standard curved surface keeps jack per line, the absolute value monotonic increase of the difference of the incident angle of incident ray on free form surface and the incident angle of this incident ray on standard curved surface, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface and the incident angle of this incident ray on standard curved surface successively decreases, with make the emergent ray of free form surface presumptive area internal ratio incident ray have evenly Illumination Distribution.

The present invention also provides a kind of light-source system, and this light-source system comprises above-mentioned even optical element.

Compared with prior art, the present invention includes following beneficial effect:

In the present invention, free form surface is by the basis of standard curved surface, adopt the deformation rule in technique scheme to carry out distortion to obtain, this free form surface can by the Illumination Distribution of the first hot spot by the incident ray weakened outside mediad be shaped to have evenly light intensity or Illumination Distribution.Relative to prior art, free form surface of the present invention forms without the need to multiple lenticule, the problem that the light utilization efficiency that above-mentioned crosstalk etc. thus can be avoided to cause reduces, and has structure simple, the advantage that light utilization efficiency is high.

Accompanying drawing explanation

Fig. 1 is the major axis of semiconductor laser on objective plane and the Light distribation on minor axis;

Fig. 2 is the major axis of light emitting diode on objective plane and the Light distribation on minor axis;

Fig. 3 is the index path of the fly's-eye lens of prior art;

Fig. 4 is the index path of the non-spherical lens of prior art;

Fig. 5 is the index path of an embodiment of even optical element of the present invention;

Fig. 6 is the index path of another embodiment of even optical element of the present invention;

Fig. 7 is the index path of another embodiment of even optical element of the present invention;

Fig. 8 is the index path of another embodiment of even optical element of the present invention;

Fig. 9 is the index path of another embodiment of even optical element of the present invention;

Figure 10 is the index path of another embodiment of even optical element of the present invention;

Figure 11 is the index path of another embodiment of even optical element of the present invention;

Figure 12 is the index path of an embodiment of light-source system of the present invention;

Figure 13 is the index path of another embodiment of light-source system of the present invention;

Figure 14 is the index path of another embodiment of light-source system of the present invention;

Figure 15 is the index path of another embodiment of light-source system of the present invention;

Figure 16 is the index path of another embodiment of light-source system of the present invention;

Figure 17 is the index path of another embodiment of light-source system of the present invention;

Figure 18 is the index path of another embodiment of light-source system of the present invention;

Figure 19 is the index path of another embodiment of light-source system of the present invention;

Figure 20 is the index path of another embodiment of light-source system of the present invention;

Figure 21 is the index path of another embodiment of light-source system of the present invention;

Figure 22 is the index path of another embodiment of light-source system of the present invention;

Figure 23 is the index path of another embodiment of light-source system of the present invention;

Figure 24 is the index path of another embodiment of light-source system of the present invention;

Figure 25 is the index path of another embodiment of light-source system of the present invention;

Figure 26-27 is index paths of another embodiment of light-source system of the present invention;

Figure 28 is the index path of another embodiment of light-source system of the present invention;

Figure 29 is the index path of another embodiment of light-source system of the present invention;

Figure 30 is the index path of another embodiment of light-source system of the present invention.

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention is described in detail.

Technical term is explained:

Rectangle solid angle: as shown in figure 31, the vertical line of mistake rectangle ABCD central point has 1 O, and rectangle ABCD is a rectangle solid angle to the solid angle that an O opens;

The big angle of rectangle solid angle: as shown in figure 31, the angle that the line segment of the mid point and the mid point of wide CD that connect wide AB is opened an O;

The little angle of rectangle solid angle: as shown in figure 31, the angle that the line segment of the mid point and the mid point of long BC that connect long AD is opened an O;

Illumination: the luminous flux of unit are;

Light intensity: the luminous flux in unit solid angle.

Refer to the index path that Fig. 5 a and Fig. 5 b, Fig. 5 a is an even optical element of the present invention embodiment, Fig. 5 b is the principle analysis figure of free form surface 34 in Fig. 5 a illustrated embodiment.

As shown in Figure 5 a, in the present embodiment, even optical element comprises the free form surface 33 (or 34) of incident ray shaping for producing light source 31.Light source 31 can be spot light, and the incident ray namely inciding free form surface 33 (or 34) is directly produced by spot light.The incident ray that light source 31 produces forms the first hot spot in a plane of the central axis with this light source 31, and the Illumination Distribution of the first hot spot weakens by outside mediad.The Illumination Distribution of the first hot spot can be oval Gaussian Profile or lambertian distribution.

Free form surface 33 (or 34) is out of shape acquisition by the standard curved surface 32 in precalculated position of the central axis direction being positioned at light source 31, and this standard curved surface is the curved surface that the incident ray that can produce light source 31 be shaped as directional light.Precalculated position from light source more away from, the size of free form surface is larger, and cost of manufacture is higher; Precalculated position from light source more close to, the size of free form surface is less, and manufacture difficulty is higher, and thus precalculated position can be arranged according to the actual requirements.Free form surface 33 (or 34) and standard curved surface 32 are transmission curved surface.About standard curved surface, in the present embodiment, be specially the ellipsoid that the incident ray that can produce light source 31 is shaped as directional light.

For free form surface 33, the present embodiment limits as follows: except the central axis direction of light source 31, (direction from a to b is comprised along from this central shaft to the direction of the side direction of central shaft, or the direction from a to c), the incident angle of incident ray on free form surface 33 that light source 31 produces and the difference of the incident angle of this incident ray on standard curved surface 32 keep jack per line (be specially and all keep positive sign), the absolute value monotonic increase of the incident angle of incident ray on free form surface 33 that light source 31 produces and the difference of the incident angle of this incident ray on standard curved surface 32, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface 33 and the incident angle of this incident ray on standard curved surface 32 successively decreases, with make the emergent ray of free form surface 33 the incident ray that predetermined solid angle internal ratio light source 31 produces have evenly light distribution.Such as, along the direction from a to b and the direction from a to c, the incident angle of incident ray on free form surface 33 that light source 31 produces and the difference of the incident angle of this incident ray on standard curved surface 32 increase progressively to 10 degree continuously by 1 degree, and this speed increased progressively reduces gradually.

For free form surface 34, the present embodiment limits as follows: except the central axis direction of light source 31, (direction from d to e is comprised along from this central shaft to the direction of the side direction of central shaft, or the direction from d to f), the incident angle of incident ray on free form surface 34 that light source 31 produces and the difference of the incident angle of this incident ray on standard curved surface 32 keep jack per line (be specially and all keep negative sign), the absolute value monotonic increase of the incident angle of incident ray on free form surface 34 that light source 31 produces and the difference of the incident angle of this incident ray on standard curved surface 32, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface 34 and the incident angle of this incident ray on standard curved surface 32 successively decreases, with make the emergent ray of free form surface 34 the incident ray that predetermined solid angle internal ratio light source 31 produces have evenly light distribution.Such as, along the direction from d to e and the direction from d to f, the difference of the incident angle of incident ray on free form surface 34 that light source 31 produces and the incident angle of this incident ray on standard curved surface 32 is spent by-1 and extremely-10 is spent and successively decrease continuously, and this speed of successively decreasing reduces gradually.

Predetermined solid angle can be arranged according to different demand.Such as, the cone angle within predetermined solid angle can be 45 degree, also can cone angle within 30 degree.Predetermined solid angle can be the cone angle of the taper of rectangle for bottom surface, can be also the cone angle of orthohexagonal taper for bottom surface.

The emergent ray of free form surface 33 (or 34) the incident ray that predetermined solid angle internal ratio light source 31 produces have evenly light distribution, refer to the uniform intensity Du Genggao of incident ray in predetermined solid angle that the uniform intensity degree of the emergent ray of free form surface 33 (or 34) in predetermined solid angle produces than light source 31.Uniform intensity degree in predetermined solid angle can adopt various ways to represent, such as, can be the ratio of the light intensity minimum of a value in predetermined solid angle and the light intensity mean value in predetermined solid angle; Also can the ratio of the light intensity maximum in predetermined solid angle and the light intensity mean value in predetermined solid angle; Also can be the ratio of the difference of the light intensity mean value in predetermined solid angle and the light intensity maximum in predetermined solid angle and light intensity minimum of a value; Do not enumerate herein.

For ease of understanding, below the principle that free form surface in the present embodiment 34 realizes higher uniform intensity degree is analyzed; Meanwhile, for ease of describe, below by the side direction of central shaft referred to as side:

As shown in figure 5 a and 5b, the incident ray that light source 31 sends is shaped to directional light by standard curved surface 32, and the emergent ray that namely standard curved surface 32 is all is distributed in 0 degree of solid angle.Therefore, free form surface 34 changes the incidence angle of incident ray, and corresponding emergent ray will be made to depart from 0 degree; The knots modification (absolute value) of incidence angle increases progressively from the central shaft of light source to side, such as knots modification is followed successively by 20 degree and 30 degree, then from the central shaft of light source to side, departing from of the emergent ray of free form surface 34 and 0 degree also increases progressively, and the emergent ray of free form surface 34 thus can be made to be distributed in predetermined solid angle; When the light distribution of the incident ray that light source 31 produces is successively decreased from central shaft to side, can successively decrease by making the rate of change of free form surface 34 to the knots modification of this incident ray incidence angle, improving the uniformity of the light distribution of emergent ray in predetermined solid angle of free form surface 34.

Such as, describe for simplifying problem, make an explanation with two-dimensional case, now solid angle is reduced to angle, meanwhile, the Angulation changes amount of the emergent ray of free form surface 34 can be similar to the knots modification of the incident ray incidence angle being considered as free form surface 34.As shown in Figure 5 b, the incident ray that light source produces is distributed in 0-40 degree, and the predetermined angular of the emergent ray of free form surface 34 is in 0-30 degree.The incident ray produced due to light source is comparatively large in the light intensity of the central axis of light source, and such as, the luminous flux of this incident ray in 0-20 degree is 2 times of luminous flux in 20-40 degree.For making the emergent ray of free form surface 34 uniform intensity in 0-30 degree, so, the emergent ray that incident ray in 0-20 degree is corresponding should be distributed in 0-20 degree, namely the emergent ray that the incident ray of 20 degree is corresponding answers 20 degree, displaced central axis direction, and emergent ray corresponding to incident ray in 20-40 degree should be distributed in 20-30 degree, i.e. the emergent ray displaced central axis 30 degree of incident ray of 40 degree.Therefore, the incidence angle variable quantity of the incident ray of 20 degree is 20, and the incidence angle variable quantity because of the incident ray of 0 degree is 0, then in 0-20 degree, the average rate of change of the incidence angle converted quantity of incident ray is about (20-0)/(20-0)=1; The incidence angle variable quantity of the incident ray of 40 degree is 30, because the incidence angle variable quantity of the incident ray of 20 degree is 20, then the average rate of change of the incidence angle variable quantity of 20-40 degree incident ray is about (30-20)/(40-20)=0.5, is 1/2 of the average rate of change of the incidence angle converted quantity of incident ray in 0-20 degree.As can be seen here, can successively decrease by making the rate of change of free form surface 34 to the knots modification of this incident ray incidence angle, improving the uniformity of the light distribution of emergent ray in predetermined solid angle of free form surface 34.

It is easily understood that, above-mentioned rate of change successively decreases degree difference, the uniformity of the light distribution of emergent ray in predetermined solid angle of free form surface 34 is also different, and those skilled in the art according to the different requirements to uniformity, can determine the degree of successively decreasing of this rate of change by emulation experiment etc.What deserves to be explained is, when rate of change successively decrease degree excessive time, the emergent ray of free form surface 34 light intensity in polarizers of big angle scope can be caused large, in small angle range, light intensity is little, and cause the light distribution of the incident ray produced than light source more uneven, thus the degree of successively decreasing of above-mentioned rate of change need control within the specific limits, and certainly, these those skilled in the art also can pass easily through emulation experiment and determine.

Free form surface 33 realizes the principle of higher uniform intensity degree and the identical of free form surface 34, no longer analyzes herein.

In the present embodiment, free form surface is by the basis of standard curved surface, adopt the deformation rule in technique scheme to carry out distortion to obtain, this free form surface can by the Illumination Distribution of the first hot spot by the incident ray weakened outside mediad be shaped to have evenly light distribution.Relative to prior art, free form surface of the present invention forms without the need to multiple lenticule, the problem that the light utilization efficiency that above-mentioned crosstalk etc. thus can be avoided to cause reduces, and has structure simple, the advantage that light utilization efficiency is high.

Refer to Fig. 6, Fig. 6 is the index path of even another embodiment of optical element of the present invention.As shown in Figure 6, in the present embodiment, even optical element of the present invention comprises the free form surface 53 (or 54) of incident ray shaping for producing light source 51, this incident ray forms the first hot spot in a plane of the central axis with this light source 51, and the Illumination Distribution of the first hot spot weakens by outside mediad.Free form surface 53 (or 54) is out of shape acquisition by the standard curved surface 52 in precalculated position of the central axis direction being positioned at light source 51.

The difference part of the present embodiment and Fig. 5 a illustrated embodiment comprises following 2 points:

(1), in the present embodiment, standard curved surface 52 and free form surface 53 (or 54) are reflecting curved surface.Particularly, standard curved surface 52 is the parabola that the incident ray that can produce light source 51 is shaped as directional light.

(2) in Fig. 5 a illustrated embodiment, along from the central shaft of light source 31 to the direction of side, it is no matter the direction from a to b, or direction from a to c, the difference of the incident angle of the incident ray that light source 31 produces on free form surface 33 and the incident angle of this incident ray on standard curved surface 32 all keeps positive sign; Along from the central shaft of light source 31 to the direction of side, it is no matter the direction from d to e, or direction from d to f, the difference of the incident angle of the incident ray that light source 31 produces on free form surface 34 and the incident angle of this incident ray on standard curved surface 32 all keeps negative sign.And in the present embodiment, along from the central shaft of light source 51 to the direction of side, namely the direction from a to b and the direction from a to c, the incident angle of incident ray on free form surface 53 that light source 51 produces and the difference of the incident angle of this incident ray on standard curved surface 52 keep negative sign and positive sign respectively; Along from the central shaft of light source 51 to the direction of side, namely the direction from d to e and the direction from d to f, the incident angle of incident ray on free form surface 54 that light source 51 produces and the difference of the incident angle of this incident ray on standard curved surface 52 keep positive sign and negative sign respectively.

Such as, along the direction from a to b, the difference of the incident angle of incident ray on free form surface 53 that light source 51 produces and the incident angle of this incident ray on standard curved surface 52 is spent by-1 and extremely-10 is spent and successively decrease continuously, and this speed of successively decreasing reduces gradually; Along the direction from a to c, the incident angle of incident ray on free form surface 53 that light source 51 produces and the difference of the incident angle of this incident ray on standard curved surface 52 increase progressively to 10 degree continuously by 1 degree, and this speed increased progressively reduces gradually; Along the direction from d to e, the incident angle of incident ray on free form surface 54 that light source 51 produces and the difference of the incident angle of this incident ray on standard curved surface 52 increase progressively to 10 degree continuously by 1 degree, and this speed increased progressively reduces gradually; Along the direction from d to f, the difference of the incident angle of incident ray on free form surface 54 that light source 51 produces and the incident angle of this incident ray on standard curved surface 52 is spent by-1 and extremely-10 is spent and successively decrease continuously, and this speed of successively decreasing reduces gradually.

Refer to Fig. 7, Fig. 7 is the index path of another embodiment of even optical element of the present invention.As shown in Figure 7, in the present embodiment, even optical element of the present invention comprises the free form surface 72 (or 73) of incident ray shaping for producing light source (not shown), this incident ray forms the first hot spot in a plane of the central axis with this light source, and the Illumination Distribution of the first hot spot weakens by outside mediad.Free form surface 72 (or 73) is out of shape acquisition by the standard curved surface 71 in precalculated position of the central axis direction being positioned at light source.

The present embodiment and difference part embodiment illustrated in fig. 6 are: in the present embodiment, and the incident ray of free form surface 72 (or 73) is parallel rays; Standard curved surface 71 is the plane of reflection that can fold incident ray.

Refer to Fig. 8, Fig. 8 is the index path of even another embodiment of optical element of the present invention.The present embodiment comprises free form surface 91, and free form surface 91 is concrete manifestation forms of the free form surface in Fig. 5 a or Fig. 6 embodiment.

As shown in Figure 8, in the present embodiment, light-source system comprises spot light O, free form surface 91.The set of the emergent ray of free form surface 91 is 92.The distance of the point-to-point light source O on free form surface 91 solves acquisition by following formula by numerical approach:

$\left\{\begin{array}{c}\frac{|{\∂}_{1}T\left(m\right)\×{\∂}_{2}T\left(m\right)|}{\det \left(e_{\mathrm{ij}}\right)}=\frac{i\left(m\right)}{f\left(T\left(m\right)\right)}\\ \mathrm{\ρ}\left(m_0\right)={\mathrm{\ρ}}_0\end{array}\right.;$

$T\left(m\right)=\frac{n_1}{n_2}m+[-\frac{n_1}{n_2}\frac{\mathrm{\ρ}}{\sqrt{{\mathrm{\ρ}}^2+{|\▿\mathrm{\ρ}|}^2}}+\sqrt{1-{\left(\frac{n_1}{n_2}\right)}^2\frac{{|\▿\mathrm{\ρ}|}^2}{{\mathrm{\ρ}}^2+{|\▿\mathrm{\ρ}|}^2}}]\frac{(\▿\mathrm{\ρ}-\mathrm{\ρm})}{\sqrt{{\mathrm{\ρ}}^2+{|\▿\mathrm{\ρ}|}^2}},$

Wherein, the light distribution of the incident ray that i (m) produces for spot light O, m is the unit vector from spot light O to the point free form surface 91, ρ (m) be on m direction spot light O to the distance of the point on free form surface 91, can be used for freedom of expression curved surface 91, m ₀for a direction chosen, ρ ₀for at m ₀on direction, spot light is to the distance of the point on free form surface 91, the light distribution of emergent ray in predetermined solid angle that f (T (m)) is free form surface 91, n ₁for refractive index, the n of incident ray place medium ₂for the refractive index of the emergent ray place medium of free form surface 91, e=e _ijdt ⁱdt ^jrepresent the first fundamental form of curved surface, e ^ij=(e _ij) ^-1, t _iwith t _jbe respectively two parameters in the parametric equation of curved surface.When free form surface 91 is reflecting surface, n ₁=-n ₂.

Preferably, predetermined solid angle is predetermined rectangle solid angle, the even light distribution of the emergent ray that f (T (m)) is free form surface in this predetermined rectangle solid angle, to adapt to show at present widely used rectangular display screen curtain in field.Now, more preferably, the big angle of predetermined rectangle solid angle and little angle are all more than or equal to 0.01 degree and are less than or equal to 3 degree.Certainly, predetermined solid angle also can be the solid angle of other type, and such as bottom surface is the solid angle of the taper of equilateral triangle, regular hexagon or ellipse.

In addition, m ₀be preferably the central axis direction of spot light, so that calculate.Now, ρ ₀be preferably greater than or equal to 2mm and be less than or equal to 50mm.

The light distribution of the incident ray that spot light O produces can have multiple.In an alternative of the present invention, the light distribution of the incident ray that spot light O produces can be the light distribution of oval gaussian-shape, namely $i\left(m\right)=I_0\exp \left[(-\frac{{\mathrm{\θ}}^2}{2})(\frac{{\cos }^2\mathrm{\φ}}{{\mathrm{\σ}}_x^2}+\frac{{\sin }^2\mathrm{\φ}}{{\mathrm{\σ}}_y^2})\right],$ Wherein I ₀for the light intensity of the central axis direction of spot light O, (θ, φ) is with spot light O for initial point and with the coordinate of point corresponding to the unit vector m in the central axis direction of the spot light O spherical coordinates that is pole axis, σ _xfor in the major axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle, σ _yfor in the minor axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle.In another alternative of the present invention, the light distribution of the incident ray that spot light O produces is the light distribution of lambert, i.e. i (m)=I ₀cos (θ), wherein I ₀for the light intensity of the central axis direction of spot light O, θ is the angle of unit vector m and central axis direction.

Above-described embodiment is that the free form surface that can realize uniform intensity degree higher is described to even optical element, is that the free form surface that can realize uniformity of illuminance higher is described in detail below to even optical element.

Refer to Fig. 9, Fig. 9 is the index path of even another embodiment of optical element of the present invention.As shown in Figure 9, in the present embodiment, even optical element comprises the free form surface 43 of incident ray shaping for producing light source 41.Light source 41 can be spot light, and the incident ray namely inciding free form surface 43 is directly produced by spot light.The incident ray that light source 41 produces forms the first hot spot in a plane of the central axis with this light source 41, and the Illumination Distribution of the first hot spot weakens by outside mediad.The Illumination Distribution of the first hot spot can be oval Gaussian Profile or lambertian distribution.Free form surface 43 is out of shape acquisition by the standard curved surface 42 in precalculated position of the central axis direction being positioned at light source 41.

The present embodiment and difference part embodiment illustrated in fig. 5 comprise following 2 points:

(1) in the present embodiment, standard curved surface 42 is the curved surface that the incident ray that light source 41 produces can be converged at the central point of presumptive area, is specially Descartes's ellipsoid.Presumptive area can be arranged according to the actual requirements, can have multiple, the rectangular area of such as a specific dimensions and shape, elliptical region, delta-shaped region or regular hexagon region etc.

(2) except the central axis direction of light source 41, (direction from d to e is comprised along the direction from this central shaft to side, or the direction from d to f), the incident angle of incident ray on free form surface 43 that light source 41 produces and the difference of the incident angle of this incident ray on standard curved surface 42 keep jack per line (be specially and all keep negative sign), the absolute value monotonic increase of the incident angle of incident ray on free form surface 43 that light source 41 produces and the difference of the incident angle of this incident ray on standard curved surface 42, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface 43 and the incident angle of this incident ray on standard curved surface 42 successively decreases, with make the emergent ray of free form surface 43 the incident ray that presumptive area internal ratio light source 41 produces have evenly Illumination Distribution.Namely in the present embodiment, free form surface 43 be in order to realize evenly Illumination Distribution, but not light distribution.

The emergent ray of free form surface 43 the incident ray that presumptive area internal ratio light source 41 produces have evenly Illumination Distribution, refer to that the uniformity of illuminance of incident ray in presumptive area that the uniformity ratio of illuminance light source 41 of the emergent ray of free form surface 43 in presumptive area produces is higher.Uniformity of illuminance in presumptive area can adopt various ways to represent, such as, can be the ratio of the illumination minimum of a value in presumptive area and the illumination mean value in presumptive area; Also can the ratio of the illumination maximum in presumptive area and the illumination mean value in presumptive area; Also can be the ratio of the difference of the illumination mean value in presumptive area and the illumination maximum in presumptive area and illumination minimum of a value; Do not enumerate herein.Free form surface 43 realizes the principle of higher uniformity of illuminance and the identical of free form surface 34, no longer analyzes herein.

It is easily understood that, also can carry out distortion to standard curved surface 42 in the present embodiment and obtain another free form surface, the incident angle of incident ray on this free form surface that light source 41 produces and the difference of the incident angle of this incident ray on standard curved surface 42 keep jack per line (be specially and all keep positive sign), this free form surface be similar to embodiment illustrated in fig. 5 in free form surface 34.

In the present embodiment, free form surface is by the basis of standard curved surface, adopt the deformation rule in technique scheme to carry out distortion to obtain, this free form surface can by the Illumination Distribution of the first hot spot by the incident ray weakened outside mediad be shaped to have evenly Illumination Distribution.Relative to prior art, free form surface of the present invention forms without the need to multiple lenticule, the problem that the light utilization efficiency that above-mentioned crosstalk etc. thus can be avoided to cause reduces, and has structure simple, the advantage that light utilization efficiency is high.

Refer to Figure 10, Figure 10 is the index path of even another embodiment of optical element of the present invention.As shown in Figure 10, in the present embodiment, even optical element comprises the free form surface 63 (or 64) of incident ray shaping for producing light source 61, this incident ray forms the first hot spot in a plane of the central axis with this light source 61, and the Illumination Distribution of the first hot spot weakens by outside mediad.Free form surface 63 (or 64) is out of shape acquisition by the standard curved surface 62 in precalculated position of the central axis direction being positioned at light source 61.

The present embodiment and difference part embodiment illustrated in fig. 9 are: in the present embodiment, and free form surface 63 (or 64) and standard curved surface 52 are reflecting curved surface, and standard curved surface 52 is the ellipsoid that incident ray can be converged at the central point of presumptive area.

In the present embodiment, along the direction of central shaft to two side from light source 61, namely from central shaft to the direction of right edge and from central shaft to the direction on limit, left side, the incident angle of incident ray on free form surface 63 that light source 61 produces and the difference of the incident angle of this incident ray on standard curved surface 62 keep negative sign and positive sign respectively.Along the direction of central shaft to two side from light source 61, namely from central shaft to the direction of right edge and from central shaft to the direction on limit, left side, the incident angle of incident ray on free form surface 64 that light source 61 produces and the difference of the incident angle of this incident ray on standard curved surface 62 keep positive sign and negative sign respectively.

Refer to Figure 11, Figure 11 is the index path of even another embodiment of optical element of the present invention.As shown in figure 11, in the present embodiment, even optical element comprises the free form surface 82 (or 83) of incident ray shaping for producing light source (not shown), this incident ray forms the first hot spot in a plane of the central axis with this light source 81, and the Illumination Distribution of the first hot spot weakens by outside mediad.Free form surface 82 (or 83) is out of shape acquisition by the standard curved surface 81 in precalculated position of the central axis direction being positioned at light source.

The present embodiment and difference part embodiment illustrated in fig. 10 are: in the present embodiment, and the incident ray of free form surface 82 (or 83) is parallel rays, and standard curved surface 81 is the parabola that incident ray can be converged at the central point of presumptive area.

In the present embodiment, along the direction of central shaft to two side from light source, namely from central shaft to the direction of right edge and from central shaft to the direction on limit, left side, the incident angle of incident ray on free form surface 82 that light source produces and the difference of the incident angle of this incident ray on standard curved surface 81 keep negative sign and positive sign respectively.Along the direction of central shaft to two side from light source, namely from central shaft to the direction of right edge and from central shaft to the direction on limit, left side, the incident angle of incident ray on free form surface 83 that light source produces and the difference of the incident angle of this incident ray on standard curved surface 81 keep positive sign and negative sign respectively.

In addition, with Fig. 5 a, embodiment illustrated in fig. 6 identical, Fig. 9, embodiment illustrated in fig. 10 in free form surface also can adopt concrete manifestation form embodiment illustrated in fig. 8.As shown in Figure 8, when embodiment illustrated in fig. 8 be Fig. 9, concrete manifestation form embodiment illustrated in fig. 10 time, the distance of the point-to-point light source O on free form surface 91 solves acquisition by following formula by numerical approach:

$\left\{\begin{array}{c}\frac{|{\∂}_{1}T\left(m\right)\×{\∂}_{2}T\left(m\right)|}{\det \left(e_{\mathrm{ij}}\right)}=\frac{i\left(m\right)}{f\left(T\left(m\right)\right)}\\ \mathrm{\ρ}\left(m_0\right)={\mathrm{\ρ}}_0\end{array}\right.;$

$T\left(m\right)=\frac{n_1}{n_2}m+[-\frac{n_1}{n_2}\frac{\mathrm{\ρ}}{\sqrt{{\mathrm{\ρ}}^2+{|\▿\mathrm{\ρ}|}^2}}+\sqrt{1-{\left(\frac{n_1}{n_2}\right)}^2\frac{{|\▿\mathrm{\ρ}|}^2}{{\mathrm{\ρ}}^2+{|\▿\mathrm{\ρ}|}^2}}]\frac{(\▿\mathrm{\ρ}-\mathrm{\ρm})}{\sqrt{{\mathrm{\ρ}}^2+{|\▿\mathrm{\ρ}|}^2}},$

Wherein, the light distribution of the incident ray that i (m) produces for spot light O, m is the unit vector from spot light O to the point free form surface 91, ρ (m) be on m direction spot light O to the distance of the point on free form surface 91, can be used for freedom of expression curved surface 91, m ₀for a direction chosen, ρ ₀for at m ₀on direction, spot light is to the distance of the point on free form surface 91, the Illumination Distribution of emergent ray in presumptive area that f (T (m)) is free form surface 91, n ₁for refractive index, the n of incident ray place medium ₂for the refractive index of the emergent ray place medium of free form surface 91, e=e _ijdt ⁱdt ^jrepresent the first fundamental form of curved surface, e ^ij=(e _ij) ^-1, t _iwith t _jbe respectively two parameters in the parametric equation of curved surface.When free form surface 91 is reflecting surface, n ₁=-n ₂.

Mention in embodiment illustrated in fig. 9, presumptive area can be arranged according to the actual requirements, can have multiple.Preferably, presumptive area is predetermined rectangular area, the uniform illuminance of the emergent ray that f (T (m)) is free form surface in this predetermined rectangular area, to adapt to show at present widely used rectangular display screen curtain in field.Now, more preferably, the distance of predetermined rectangular area and light source O is greater than 10mm and is less than 500mm, the length of this predetermined rectangular area and be widely all more than or equal to 1mm and be less than or equal to 5mm.

In addition, m ₀be preferably the central axis direction of spot light, so that calculate.Now, ρ ₀be preferably greater than or equal to 2mm and be less than or equal to 50mm.

The light distribution of the incident ray that spot light O produces can have multiple.In an alternative of the present invention, the light distribution of the incident ray that spot light O produces can be the light distribution of oval gaussian-shape, namely $i\left(m\right)=I_0\exp \left[(-\frac{{\mathrm{\θ}}^2}{2})(\frac{{\cos }^2\mathrm{\φ}}{{\mathrm{\σ}}_x^2}+\frac{{\sin }^2\mathrm{\φ}}{{\mathrm{\σ}}_y^2})\right],$ Wherein I ₀for the light intensity of the central axis direction of spot light O, (θ, φ) is with spot light O for initial point and with the coordinate of point corresponding to the unit vector m in the central axis direction of the spot light O spherical coordinates that is pole axis, σ _xfor in the major axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle, σ _yfor in the minor axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle.In another alternative of the present invention, the light distribution of the incident ray that spot light O produces is the light distribution of lambert, i.e. i (m)=I ₀cos (θ), wherein I ₀for the light intensity of the central axis direction of spot light O, θ is the angle of unit vector m and central axis direction.

The various ways of realization of light-source system of the present invention will be enumerated below.

Refer to Figure 12, Figure 12 is the index path of an embodiment of light-source system of the present invention.As shown in figure 12, in the present embodiment, light-source system comprises a light source 121, comprises even optical element and the imaging len 123 of transmission curved surface 122 and transmission curved surface 124.

Light source 121 is specially a single point light source 121, and its light produced forms the first hot spot in the plane of the central axis with this light source 121, and the Illumination Distribution of the first hot spot weakens by outside mediad.Particularly, the light distribution of the light that light source 121 produces can be the light distribution of oval gaussian-shape, also can be the light distribution of lambert.

Even optical element is lens (signs), and transmission curved surface 122 and transmission curved surface 124 are two faces of these lens.Transmission curved surface 124 is set to vertical with incident light direction, not change incident light direction, and transmission curved surface 122 be embodiment illustrated in fig. 5 in free form surface, the emergent ray of transmission curved surface 122 predetermined solid angle internal ratio incident ray have evenly light distribution.

Preferably, light source 121 is radiated at light beam on transmission curved surface 122 through transmission curved surface 122 shaping, its light intensity is uniformly distributed in a rectangle solid angle, then through imaging len 123, light beam forms the second hot spot S of uniform illuminance in the predetermined rectangular area of the focal plane of imaging len 123.

Refer to Figure 13, Figure 13 is the index path of another embodiment of light-source system of the present invention.As shown in figure 13, the present embodiment is with difference part embodiment illustrated in fig. 12: the present embodiment comprises multiple spot light and the even optical element corresponding respectively with the plurality of spot light, the polishing of the spot light of correspondence is formed in optical power detection in predetermined rectangle solid angle and drops on the diverse location with an imaging len by each even optical element, and the emergent light of each even optical element forms the second hot spot of identical rectangular uniform Illumination Distribution in the same position of the focal plane of imaging len.

Particularly, the present embodiment comprises 3 spot lights 141,142,143, and 3 the even optical elements corresponding respectively with these 3 spot lights, 3 even optical elements comprise transmission curved surface 148 and 144, transmission curved surface 149 and 145, transmission curved surface 150 and 146 respectively.Wherein transmission curved surface 148,149,150 is set to vertical with incident light direction.The shape of the transmission curved surface 144,145,146 of diverse location is identical, and incident light is shaped to the light beam of optical power detection in predetermined rectangle solid angle by each transmission curved surface.The emergent light of the transmission curved surface 144,145,146 of diverse location, through imaging len 147, the same position of imaging len 147 focal plane forms the second hot spot of identical rectangular uniform Illumination Distribution.

Refer to Figure 14, Figure 14 is the index path of another embodiment of light-source system of the present invention.As shown in figure 14, the present embodiment comprises light source 131, even optical element 132 and imaging len 133.The present embodiment and difference part embodiment illustrated in fig. 12 are: the even optical element in the present embodiment is a reflecting curved surface 132, reflecting curved surface 132 be embodiment illustrated in fig. 6 in free form surface.

Refer to Figure 15, Figure 15 is the index path of another embodiment of light-source system of the present invention.The present embodiment is with difference part embodiment illustrated in fig. 14: the present embodiment comprises multiple spot light and the even optical element corresponding respectively with the plurality of spot light, the polishing of the spot light of correspondence is formed in optical power detection in predetermined rectangle solid angle and drops on the diverse location with an imaging len by each even optical element, and the emergent light of each even optical element forms the second hot spot of identical rectangular uniform Illumination Distribution in the same position of the focal plane of imaging len.

Particularly, the present embodiment comprises 3 spot lights 151,152,153, and 3 the even optical elements corresponding respectively with these 3 spot lights, 3 even optical elements comprise reflecting curved surface 154,155,156 respectively.The shape of the reflecting curved surface 154,155,156 of diverse location is identical, and towards identical, separately incident light is shaped to the light beam of optical power detection in predetermined rectangle solid angle.The emergent light of the reflecting curved surface 154,155,156 of diverse location, through imaging len 157, the same position of imaging len 157 focal plane forms the second hot spot of identical rectangular uniform Illumination Distribution.

Refer to Figure 16, Figure 16 is the index path of another embodiment of light-source system of the present invention.As shown in figure 16, in the present embodiment, light-source system comprise spot light 161,162, respectively with spot light 161,162 corresponding reflecting curved surfaces 163,166, the shape of the reflecting curved surface 163,166 of diverse location is identical.Light-source system comprises the plane of reflection 164,165 and imaging len 167 further.Reflecting curved surface 163 and 166 carries out shaping to the light that spot light 161,162 produces respectively, and the emergent light of the plane of reflection 164 and 165 reflecting curved surface 163 and 166 respectively carries out light path folding.The emergent light of the plane of reflection 164,165, through imaging len 167, the same position of the focal plane of imaging len 167 forms the second hot spot of identical rectangular uniform Illumination Distribution.Wherein, reflecting curved surface 163,166 be embodiment illustrated in fig. 6 in free form surface.

In the present embodiment, spot light 161,162 towards unanimously, thus there is the advantage of being convenient to install.And, two reflecting curved surfaces 163 and 166 are arranged in opposite directions, the plane of reflection is arranged in opposite directions with corresponding reflecting curved surface, two neighboring reflection planes 164,165 seamless spliced, make some overlap of the emergent light of the plane of reflection 164,165 or only have less interval, thus make light-source system compacter, and improve the utilization rate of imaging len 167.

In addition, also can arrange and overlap light source, reflecting curved surface and the plane of reflection more and make this many cover along arranging perpendicular to cross-wise direction as shown in figure 16, to improve the optical power density of light-source system.

Refer to Figure 17, Figure 17 is the index path of another embodiment of light-source system of the present invention.As shown in figure 17, in the present embodiment, light-source system comprise spot light 171,172, respectively with spot light 171,172 corresponding reflecting curved surfaces 173,174 and imaging len 175.The present embodiment and difference part embodiment illustrated in fig. 16 are: the spot light 171,172 in the present embodiment is arranged in opposite directions, the mutual setting dorsad of reflecting curved surface 173,174 is also seamless spliced, make some overlap of the emergent light of reflecting curved surface 173,174 or only have less interval, thus make light-source system compacter, and improve the utilization rate of imaging len 167.

In addition, also can arrange many cover light sources with reflecting curved surface makes this edge of overlapping arrange perpendicular to cross-wise direction as shown in figure 17, to improve the optical power density of light-source system more.

Refer to Figure 18, Figure 18 is the index path of another embodiment of light-source system of the present invention.As shown in figure 18, in the present embodiment, light-source system comprises multiple spot light 211,212,213, respectively with multiple spot light 211,212,213 corresponding multiple reflecting curved surfaces 214,215,216, and respectively with multiple reflecting curved surface 214,215, the 216 corresponding planes of reflection 217,218,219.Reflecting curved surface 214,215,216 be embodiment illustrated in fig. 6 in free form surface.Spot light 211,212,213, reflecting curved surface 214,215,216 and the plane of reflection 217,218,219 all towards unanimously, thus have the advantage of being convenient to install.The emergent ray of reflecting curved surface 214,215,216 changes radiation direction through the plane of reflection 217,218,219 respectively thus upwards propagates, the emergent light of each like this reflecting curved surface 214,215,216 is not shaded one another, and can be made into the array of two dimension easily.

Refer to Figure 19, Figure 19 is the index path of another embodiment of light-source system of the present invention.As shown in figure 19, the present embodiment, on basis embodiment illustrated in fig. 18, adds the plane of reflection 227,228 be arranged according to a certain gradient, with the size of the outgoing beam of squeezed light origin system.

Refer to the index path that Figure 20-21, Figure 20-21 is another embodiments of light-source system of the present invention.Wherein Figure 20 is side view, Figure 21 is top view, as shown in figures 20-21, multiple reflecting curved surface 237,238,238 ', 239,241,241 ', 242,243,243 ' identical, its emergent ray all has even light distribution in predetermined rectangle solid angle, and the emergent ray of each reflecting curved surface forms the second hot spot of identical rectangular uniform Illumination Distribution in the same position of the focal plane of imaging len 231.Reflecting curved surface 237,238,238 ', 239,241,241 ', 242,243,243 ' in side view and top view all by certain gradient or be staggered, thus in two dimensions the size of equal squeezed light origin system outgoing beam.Meanwhile, owing to being staggered, the distance between spot light increases, and is conducive to heat radiation.In side view, dotted line and solid line are illustrated respectively in reflecting curved surface in Different Plane and light source.Wherein, reflecting curved surface 237,238,238 ', 239,241,241 ', 242,243,243 ' is the free form surface in embodiment illustrated in fig. 6.

Refer to Figure 22, Figure 22 is the index path of another embodiment of light-source system of the present invention.

As shown in figure 22, in the present embodiment, light source (not shown) provides collimated light beam, multiple reflecting curved surface 201,202,203 be embodiment illustrated in fig. 7 in free form surface, and shape is identical.The emergent light of reflecting curved surface 201,202,203 through an imaging len 204, and forms the second hot spot of identical rectangular uniform Illumination Distribution in the same position of imaging len 204 focal plane.Preferably, reflecting curved surface 201,202,203 is arranged according to a certain gradient, and has less size to make the outgoing beam of light-source system.

Refer to Figure 23, Figure 23 is the index path of another embodiment of light-source system of the present invention.As shown in figure 23, in the present embodiment, light-source system comprises spot light 91, the even optical element be made up of transmission curved surface 92 and transmission curved surface 93, and the light that spot light 91 produces directly shines on transmission curved surface 93.Even optical element is lens (signs), transmission curved surface 92 and transmission curved surface 93 are two faces of these lens, transmission curved surface 93 is set to vertical with incident light direction, does not therefore change the direction of light, transmission curved surface 92 be embodiment illustrated in fig. 9 in free form surface.Light source 91 is radiated at light beam on even optical element through transmission curved surface 92 shaping, forms the second hot spot S of uniform illuminance in the predetermined rectangular area of objective plane.

Refer to Figure 24, Figure 24 is the index path of another embodiment of light-source system of the present invention.As shown in figure 24, the light-source system of the present embodiment comprises spot light 101 and reflecting curved surface 102, reflecting curved surface be embodiment illustrated in fig. 10 in free form surface.The present embodiment and difference part embodiment illustrated in fig. 23 are: the even optical element in the present embodiment is reflecting curved surface 102.

Refer to Figure 25, Figure 25 is the index path of another embodiment of light-source system of the present invention.As shown in figure 25, in the present embodiment, light-source system comprises multiple spot light 111,112,113 by arrayed, and respectively with spot light 111,112,113 corresponding multiple even optical elements.Multiple even optical element is lens, and each lens are made up of transmission curved surface 114 and 117, transmission curved surface 115 and 118, transmission curved surface 116 and 119 respectively.Transmission curved surface 117,118,119 receives the light that corresponding points light source produces respectively, and is set to vertical with incident light direction, does not thus change incident light direction.Transmission curved surface 114,115,116 be embodiment illustrated in fig. 9 in free form surface.The light beam of each point light source irradiation on the even optical element of correspondence is respectively through transmission curved surface 114,115,116 shaping, transmission curved surface 114,115,116 shape of diverse location is different, with the second hot spot making the emergent light of transmission curved surface 114,115,116 form identical rectangular uniform Illumination Distribution in the same position of objective plane.

Refer to Figure 26, Figure 26 is the index path of another embodiment of light-source system of the present invention.As shown in figure 26, in the present embodiment, light-source system comprises multiple spot light 181,182,183, and reflecting curved surface 184, this reflecting curved surface 184 be embodiment illustrated in fig. 11 in free form surface.Light-source system comprise further respectively with multiple spot light 181,182,183 corresponding multiple collimating elements 185,186,187.The light that multiple spot light 181,182,183 sends is respectively through after collimating element 185,186,187, and outgoing is multi beam directional light.Second hot spot of each bundle directional light common composition rectangular uniform Illumination Distribution through reflecting curved surface 184 shaping and on objective plane.

In the present embodiment, when the Light distribation of spot light is oval Gaussian Profile, the major axis of the ellipse that the light path after being reflected by reflecting curved surface 184 can be formed with spot light Light distribation or minor axis are in same plane.Preferably, the light path after reflecting curved surface 184 reflects and oval minor axis are in same plane, and now because the incident light angle of divergence of reflecting curved surface 184 in this plane is less, its emergent light and incident light are more easily separated.

Refer to Figure 27, Figure 27 is the index path of another embodiment of light-source system of the present invention.As shown in figure 27, light-source system comprises provides the light source of multi-beam collimation light beam and multiple different reflecting curved surface 191,192,193 corresponding from multi-beam collimation light beam respectively.Wherein, reflecting curved surface 191,192,193 be embodiment illustrated in fig. 11 in free form surface.Each reflecting curved surface forms the hot spot of identical rectangular uniform Illumination Distribution respectively on the same position of objective plane, and each hot spot superposes mutually.Reflecting curved surface 191,192,193 is arranged according to a certain gradient, thus makes the outgoing beam of light-source system have less size.

Refer to Figure 28, Figure 28 is the index path of another embodiment of light-source system of the present invention.As shown in figure 28, in the present embodiment, light-source system comprises spot light 251 and lens 252.Lens 252 are made up of curved surface 254 and curved surface 253, and the light that light source 251 produces is towards curved surface 253 outgoing.Curved surface 254 can be arbitrary face, curved surface 253 can for above-mentioned any one that have in the transmission curved surface of light shaping feature, such as Fig. 5 or embodiment illustrated in fig. 9 in free form surface.

Refer to Figure 29, Figure 29 is the index path of another embodiment of light-source system of the present invention.As shown in figure 29, in the present embodiment, light-source system comprises spot light 261 and lens 262.Lens 262 are made up of curved surface 263,264, curved surface 263 is set to vertical with incident light direction, thus do not change incident light direction, and curved surface 264 can for above-mentioned any one that have in the transmission curved surface of light shaping feature, such as Fig. 5 or embodiment illustrated in fig. 9 in free form surface.Spot light 261 is positioned at the outside of lens 262, the light that spot light produces towards curved surface 263 outgoing, then through curved surface 264 shaping.

Refer to Figure 30, Figure 30 is the index path of another embodiment of light-source system of the present invention.As shown in figure 30, in the present embodiment, light-source system comprises spot light 271 and lens 272.Lens 272 are made up of curved surface 273,274, curved surface 273 can for above-mentioned any one that have in the transmission curved surface of light shaping feature, such as Fig. 5 or embodiment illustrated in fig. 9 in free form surface, and curved surface 273 is set to vertical with incident light direction, does not thus change incident light direction.Spot light 271 is positioned at the outside of lens 272, and the light that spot light produces is towards curved surface 273 outgoing and by curved surface 273 shaping, the light be shaped is transmission curved surface 274 again.Like this, the output Light distribation of whole lens 272 is actually the output Light distribation of curved surface 273.

In sum, in the present invention, free form surface is by the basis of standard curved surface, adopt the deformation rule in technique scheme to carry out distortion to obtain, this free form surface can by the Illumination Distribution of the first hot spot by the incident ray weakened outside mediad be shaped to have evenly light intensity or Illumination Distribution.Relative to prior art, free form surface of the present invention forms without the need to multiple lenticule, the problem that the light utilization efficiency that above-mentioned crosstalk etc. thus can be avoided to cause reduces, and has structure simple, the advantage that light utilization efficiency is high.

These are only embodiments of the invention; not thereby the scope of the claims of the present invention is limited; every utilize description of the present invention and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present invention.

Claims (20)

1. an even optical element, for the incident ray shaping produced light source, this incident ray forms the first hot spot in the plane of the central axis with this light source, the Illumination Distribution of the first hot spot weakens by outside mediad, it is characterized in that, described even optical element comprises a free form surface, this free form surface by be positioned at described light source central axis direction precalculated position one standard surf deform obtain, this standard curved surface is the curved surface that can be shaped as directional light to described incident ray;

Except described central axis direction, along from this central shaft to the direction of the side direction of central shaft, the difference of the incident angle of described incident ray on free form surface and the incident angle of this incident ray on standard curved surface keeps jack per line, the absolute value monotonic increase of the difference of the incident angle of described incident ray on free form surface and the incident angle of this incident ray on standard curved surface, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface and the incident angle of this incident ray on standard curved surface successively decreases, have to make the emergent ray of free form surface incident ray described in predetermined solid angle internal ratio evenly light distribution.

2. even optical element according to claim 1, it is characterized in that, the incident ray of described free form surface is directly produced by spot light, and described free form surface and standard curved surface are transmission curved surface, and described standard curved surface is the ellipsoid that can be shaped as directional light to described incident ray.

3. even optical element according to claim 1, it is characterized in that, the incident ray of described free form surface is directly produced by spot light, and described free form surface and standard curved surface are reflecting curved surface, and described standard curved surface is the parabola that can be shaped as directional light to described incident ray.

4. even optical element according to claim 1, is characterized in that, the incident ray of described free form surface is parallel rays, and described free form surface is reflecting curved surface, and described standard curved surface is the plane of reflection.

5. the even optical element according to Claims 2 or 3, is characterized in that, the point on described free form surface solves acquisition by following formula by numerical approach to the distance of described spot light:

Wherein, the light distribution of the incident ray that i (m) produces for described spot light, m is the unit vector from described spot light to the point free form surface, ρ (m) be on m direction described spot light to the distance of the point on free form surface, m ₀for a direction chosen, ρ ₀for at m ₀on direction, described spot light is to the distance of the point on free form surface, the light distribution of the emergent ray that f (T (m)) is described free form surface in described predetermined solid angle, n ₁for refractive index, the n of described incident ray place medium ₂for the refractive index of the emergent ray place medium of described free form surface, e=e _ijdt ⁱdt ^jrepresent the first fundamental form of curved surface, e ^ij=(e _ij) ^-1, t _iwith t _jbe respectively two parameters in the parametric equation of curved surface.

6. even optical element according to claim 5, is characterized in that, described predetermined solid angle is predetermined rectangle solid angle.

7. even optical element according to claim 6, is characterized in that, big angle and the little angle of described predetermined rectangle solid angle are all more than or equal to 0.01 degree and are less than or equal to 3 degree.

8. even optical element according to claim 5, is characterized in that, m ₀for the central axis direction of described spot light, and ρ ₀be more than or equal to 2mm and be less than or equal to 50mm.

9. even optical element according to claim 5, is characterized in that, the light distribution of the incident ray that described spot light produces is the light distribution of oval gaussian-shape, namely wherein I ₀for the light intensity of the central axis direction of described spot light, (θ, φ) is with described spot light for initial point and with the coordinate of point corresponding to the described unit vector m in the central axis direction of the described spot light spherical coordinates that is pole axis, σ _xfor in the major axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle, σ _yfor in the minor axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle.

10. even optical element according to claim 5, is characterized in that, the light distribution of the incident ray that described spot light produces is the light distribution of lambert, i.e. i (m)=I ₀cos (θ), wherein I ₀for the light intensity of the central axis direction of described spot light, θ is the angle of described unit vector m and this central axis direction.

11. 1 kinds of even optical elements, for the incident ray shaping produced light source, this incident ray forms the first hot spot in the plane of the central axis with this light source, the Illumination Distribution of the first hot spot weakens by outside mediad, it is characterized in that, described even optical element comprises a free form surface, this free form surface by be positioned at described light source central axis direction precalculated position one standard surf deform obtain, this standard curved surface is the curved surface that incident ray can be converged at the central point of presumptive area;

Except described central axis direction, along from this central shaft to the direction of the side direction of central shaft, the difference of the incident angle of described incident ray on free form surface and the incident angle of this incident ray on standard curved surface keeps jack per line, the absolute value monotonic increase of the difference of the incident angle of described incident ray on free form surface and the incident angle of this incident ray on standard curved surface, and the rate of change of the absolute value of the difference of the incident angle of this incident ray on free form surface and the incident angle of this incident ray on standard curved surface successively decreases, have to make the emergent ray of free form surface incident ray described in presumptive area internal ratio evenly Illumination Distribution.

12. even optical elements according to claim 11, it is characterized in that, the incident ray of described free form surface is directly produced by spot light, described free form surface and standard curved surface are transmission curved surface or reflecting curved surface, and described standard curved surface is the ellipsoid that incident ray can be converged at the central point of presumptive area.

13. even optical elements according to claim 11, it is characterized in that, the incident ray of described free form surface is parallel rays, and described free form surface and standard curved surface are reflecting curved surface, and described standard curved surface is the parabola that incident ray can be converged at the central point of presumptive area.

14. even optical elements according to claim 12, is characterized in that, the point on described free form surface solves acquisition by following formula by numerical approach to the distance of described spot light:

Wherein, the light distribution of the incident ray that i (m) produces for described spot light, m is the unit vector from described spot light to the point free form surface, ρ (m) be on m direction described spot light to the distance of the point on free form surface, m ₀for a direction chosen, ρ ₀for at m ₀on direction, described spot light is to the distance of the point on free form surface, the Illumination Distribution of emergent ray in described presumptive area that f (T (m)) is described free form surface, n ₁for refractive index, the n of described incident ray place medium ₂for the refractive index of the emergent ray place medium of described free form surface, e=e _ijdt ⁱdt ^jrepresent the first fundamental form of curved surface, e ^ij=(e _ij) ^-1, t _iwith t _jbe respectively two parameters in the parametric equation of curved surface.

15. even optical elements according to claim 14, is characterized in that, described presumptive area is predetermined rectangular area.

16. even optical elements according to claim 15, is characterized in that, the distance of described predetermined rectangular area and described spot light is greater than 10mm and is less than 500mm, the length of described predetermined rectangular area and be widely all more than or equal to 1mm and be less than or equal to 5mm.

17. even optical elements according to claim 14, is characterized in that, the light distribution of the incident ray that described spot light produces is the light distribution of oval gaussian-shape, namely wherein I ₀for the light intensity of the central axis direction of described spot light, (θ, φ) is with described spot light for initial point and with the coordinate of point corresponding to the described unit vector m in the central axis direction of the described spot light spherical coordinates that is pole axis, σ _xfor in the major axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle, σ _yfor in the minor axis of oval Gauss and the plane at pole axis place, light intensity is reduced to I ₀'s time angle.

18. even optical elements according to claim 14, is characterized in that, the light distribution of the incident ray that described spot light produces is the light distribution of lambert, i.e. i (m)=I ₀cos (θ), wherein I ₀for the light intensity of the central axis direction of described spot light, θ is the angle of described unit vector m and this central axis direction.

19. even optical elements according to claim 14, is characterized in that, m ₀for the central axis direction of described spot light, and ρ ₀be more than or equal to 2mm and be less than or equal to 50mm.

20. 1 kinds of light-source systems, is characterized in that, described light-source system comprises the even optical element according to any one of claim 1 to 19.