CN103185286B - Homogenizing components and light source system - Google Patents

Abstract

The invention discloses a dodging element and a light source system, wherein the dodging element is used for shaping incident light generated by a light source and comprises a free-form surface which is obtained by deforming a standard curved surface at a preset position in the direction of a central axis of the light source; in addition to the direction of the central axis, along the direction from the central axis to the lateral direction of the central axis, the difference value between the incident angle of the incident light on the free-form surface and the incident angle of the incident light on the standard surface keeps the same sign, the absolute value of the difference value between the incident angle of the incident light on the free-form surface and the incident angle of the incident light on the standard surface increases monotonically, and the rate of change of the absolute value of the difference value between the incident angle of the incident light on the free-form surface and the incident angle of the incident light on the standard surface decreases, so that the emergent light of the free-form surface has more uniform light intensity distribution in a predetermined solid angle than the incident light. The invention can avoid the problem of light utilization rate reduction caused by crosstalk and the like.

Description

Homogenizing components and light source system

technical field

The invention relates to the field of illumination and display, in particular to a uniform light element and a light source system.

Background technique

Light sources such as semiconductor lasers and LEDs are widely used in lighting, projection, optical phototypesetting, optical storage and other fields. In these applications, it is necessary to form an illumination distribution with a certain size and a regular shape on the target plane as much as possible, such as a rectangular uniform distribution.

However, the light distribution of commonly used light sources is not ideal. For example, the light distribution of semiconductor lasers on the cross section is generally elliptical Gaussian. The light distribution on the long axis and short axis is shown in Figure 1. It is bell-shaped, and the light distribution on the cross-section is shown in Figure 2.

A method based on a fly-eye lens has been proposed in the literature (the paper Laser Beam ShapingTechniques). As shown in Figure 3 below: a parallel light beam with a size D is incident on a fly-eye lens pair including two fly-eye lenses. The lenses 11 and 12 are processed separately to form a rectangular light distribution, and because the area of the sub-beams is small, the light distribution in this rectangle is close to uniform. Finally, after passing through a normal lens 13 with a focal length of F, the sub-beams are superimposed on the target plane, so that a uniform illuminance is obtained in a rectangle with a size S. This method requires high machining accuracy, and the light between the microlenses 11 and 12 will have a certain amount of crosstalk, causing side lobe spots to appear on the target plane. It will affect the output of light, which will reduce the utilization rate of light.

Contents of the invention

The main technical problem to be solved by the present invention is to provide a uniform light element and a light source system, which can avoid the above-mentioned problem of lower light utilization rate caused by crosstalk and the like.

The invention provides a uniform light element, which is used to shape the incident light generated by the light source. The incident light forms a first light spot on a plane perpendicular to the central axis of the light source, and the illuminance distribution of the first light spot is weakened from the center to the outside. It is characterized in that the homogenizing element includes a free-form surface, which is obtained by deformation of a standard curved surface at a predetermined position in the direction of the central axis of the light source, and the standard curved surface is a curved surface that can reshape the incident light into parallel light;

In addition to the direction of the central axis, along the lateral direction from the central axis to the central axis, the difference between the incident angle of the incident ray on the free-form surface and the incident angle of the incident ray on the standard surface remains the same sign, and the incident ray The absolute value of the difference between the angle of incidence on the free-form surface and the angle of incidence of the incident ray on the standard surface increases monotonically, and the angle of incidence of the incident ray on the free-form surface is equal to the angle of incidence of the incident ray on the standard surface The rate of change of the absolute value of the difference decreases gradually, so that the outgoing light rays from the free-form surface have a more uniform light intensity distribution than the incoming light rays within a predetermined solid angle.

The present invention also provides a uniform light element, which is used to shape the incident light generated by the light source. The incident light forms a first light spot on a plane perpendicular to the central axis of the light source, and the illuminance distribution of the first light spot is weakened from the center to the outside. , characterized in that the homogenizing element includes a free-form surface, the free-form surface is obtained by deformation of a standard curved surface at a predetermined position in the direction of the central axis of the light source, and the standard curved surface is a curved surface that can converge incident light rays at a central point of a predetermined area ;

In addition to the direction of the central axis, along the lateral direction from the central axis to the central axis, the difference between the incident angle of the incident ray on the free-form surface and the incident angle of the incident ray on the standard surface remains the same sign, and the incident ray The absolute value of the difference between the angle of incidence on the free-form surface and the angle of incidence of the incident ray on the standard surface increases monotonically, and the angle of incidence of the incident ray on the free-form surface is equal to the angle of incidence of the incident ray on the standard surface The rate of change of the absolute value of the difference decreases gradually, so that the outgoing light of the free-form surface has a more uniform illuminance distribution than the incident light in the predetermined area.

The present invention also provides a light source system, which includes the above-mentioned uniform light element.

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

In the present invention, the free-form surface is obtained by deforming the standard curved surface by adopting the deformation law in the above-mentioned technical solution. The free-form surface can shape the illuminance distribution of the first spot from the center to the outside and weaken the incident light to have a more uniform light intensity or illuminance distribution. Compared with the prior art, the free-form surface of the present invention does not need to be composed of multiple microlenses, thus avoiding the above-mentioned problem of reduced light utilization rate caused by crosstalk and the like, and has the advantages of simple structure and high light utilization rate.

Description of drawings

Fig. 1 is the light distribution of semiconductor laser on the long axis and short axis on the target plane;

Fig. 2 is the light distribution of light-emitting diodes on the long axis and short axis on the target plane;

Fig. 3 is the light path diagram of the fly eye lens of prior art;

Fig. 4 is the light path figure of the aspheric lens of prior art;

Fig. 5 is an optical path diagram of an embodiment of the uniform light element of the present invention;

Fig. 6 is an optical path diagram of another embodiment of the uniform light element of the present invention;

Fig. 7 is an optical path diagram of another embodiment of the uniform light element of the present invention;

Fig. 8 is an optical path diagram of another embodiment of the uniform light element of the present invention;

Fig. 9 is an optical path diagram of another embodiment of the uniform light element of the present invention;

Fig. 10 is an optical path diagram of another embodiment of the uniform light element of the present invention;

Fig. 11 is an optical path diagram of another embodiment of the uniform light element of the present invention;

Fig. 12 is an optical path diagram of an embodiment of the light source system of the present invention;

Fig. 13 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 14 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 15 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 16 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 17 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 18 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 19 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 20 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 21 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 22 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 23 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 24 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 25 is an optical path diagram of another embodiment of the light source system of the present invention;

26-27 are light path diagrams of another embodiment of the light source system of the present invention;

Fig. 28 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 29 is an optical path diagram of another embodiment of the light source system of the present invention;

Fig. 30 is an optical path diagram of another embodiment of the light source system of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Explanation of technical terms:

Rectangular solid angle: as shown in Figure 31, there is a point O on the vertical line passing through the center point of rectangle ABCD, and the solid angle formed by rectangle ABCD with respect to point O is a rectangular solid angle;

The major angle of the solid angle of a rectangle: as shown in Figure 31, the angle formed by the line segment connecting the midpoint of the width AB and the midpoint of the width CD to the point O;

The small angle of the rectangular solid angle: as shown in Figure 31, the angle formed by the line segment connecting the midpoints of the length AD and the midpoint of the length BC to the point O;

Illuminance: luminous flux per unit area;

Luminous intensity: Luminous flux per unit solid angle.

Please refer to FIG. 5a and FIG. 5b. FIG. 5a is an optical path diagram of an embodiment of the light homogenizing element of the present invention, and FIG. 5b is a principle analysis diagram of the free-form surface 34 in the embodiment shown in FIG. 5a.

As shown in FIG. 5 a , in this embodiment, the uniform light element includes a free-form surface 33 (or 34 ) for shaping the incident light generated by the light source 31 . The light source 31 may be a point light source, that is, the incident light incident on the free-form surface 33 (or 34 ) is directly generated by the point light source. The incident light generated by the light source 31 forms a first light spot on a plane perpendicular to the central axis of the light source 31 , and the illuminance distribution of the first light spot weakens from the center to the outside. The illuminance distribution of the first light spot may be an elliptical Gaussian distribution or a Lambertian distribution.

The free-form surface 33 (or 34 ) is obtained by deforming a standard curved surface 32 located at a predetermined position in the direction of the central axis of the light source 31 . The standard curved surface is a curved surface capable of shaping the incident light generated by the light source 31 into parallel light. The farther the predetermined position is from the light source, the larger the size of the free-form surface is, and the higher the production cost; the closer the predetermined position is to the light source, the smaller the size of the free-form surface is, and the more difficult it is to manufacture. Therefore, the predetermined position can be set according to actual needs. Both the free-form surface 33 (or 34 ) and the standard curved surface 32 are transmission curved surfaces. Regarding the standard curved surface, in this embodiment, it is specifically an elliptical surface that can shape the incident light generated by the light source 31 into parallel light.

Regarding the free-form surface 33, this embodiment defines as follows: In addition to the direction of the central axis of the light source 31, the direction along the side from the central axis to the central axis (including the direction from a to b, or the direction from a to c direction), the difference between the angle of incidence of the incident light produced by the light source 31 on the free-form surface 33 and the angle of incidence of the incident light on the standard curved surface 32 maintains the same sign (specifically, both maintain a positive sign), and the incident light produced by the light source 31 The absolute value of the difference between the angle of incidence on the free-form surface 33 and the angle of incidence of the incident ray on the standard curved surface 32 increases monotonically, and the angle of incidence of the incident ray on the free-form surface 33 is the same as that of the incident ray on the standard curved surface 32 The rate of change of the absolute value of the difference of incident angles decreases gradually, so that the outgoing light rays from the free-form surface 33 have a more uniform light intensity distribution than the incident light rays generated by the light source 31 within a predetermined solid angle. For example, along the direction from a to b and the direction from a to c, the difference between the incident angle of the incident ray generated by the light source 31 on the free-form surface 33 and the incident angle of the incident ray on the standard curved surface 32 is equal to 1 degrees to 10 degrees, and the rate of increase gradually decreases.

Regarding the free-form surface 34, this embodiment defines as follows: In addition to the direction of the central axis of the light source 31, the direction along the side from the central axis to the central axis (including the direction from d to e, or the direction from d to f direction), the difference between the angle of incidence of the incident light produced by the light source 31 on the free-form surface 34 and the angle of incidence of the incident light on the standard curved surface 32 maintains the same sign (specifically, both maintain a negative sign), and the incident light produced by the light source 31 The absolute value of the difference between the angle of incidence on the free-form surface 34 and the angle of incidence of the incident ray on the standard curved surface 32 increases monotonically, and the angle of incidence of the incident ray on the free-form surface 34 is the same as that of the incident ray on the standard curved surface 32 The rate of change of the absolute value of the difference of incident angles decreases gradually, so that the outgoing light rays from the free-form surface 34 have a more uniform light intensity distribution than the incident light rays generated by the light source 31 within a predetermined solid angle. For example, along the direction from d to e and the direction from d to f, the difference between the incident angle of the incident ray generated by the light source 31 on the free-form surface 34 and the incident angle of the incident ray on the standard curved surface 32 is given by - Continuous decrement from 1 degree to -10 deg, and the rate of decrement gradually decreases.

The predetermined solid angle can be set according to different requirements. For example, the predetermined solid angle may be a cone angle within 45 degrees, or a cone angle within 30 degrees. The predetermined solid angle may be the cone angle of a cone whose base is rectangular, or may be the cone angle of a cone whose base is a regular hexagon.

The outgoing light of the free-form surface 33 (or 34) has a more uniform light intensity distribution than the incident light produced by the light source 31 in a predetermined solid angle, which refers to the light intensity of the outgoing light of the free-form surface 33 (or 34) in a predetermined solid angle The uniformity is higher than the light intensity uniformity of the incident light generated by the light source 31 within a predetermined solid angle. The uniformity of light intensity in a predetermined solid angle can be expressed in various ways, for example, it can be the ratio of the minimum value of light intensity in a predetermined solid angle to the average value of light intensity in a predetermined solid angle; The ratio of the intensity maximum value and the light intensity average value in the predetermined solid angle; it can also be the ratio of the difference between the light intensity average value in the predetermined solid angle and the light intensity maximum value and the light intensity minimum value in the predetermined solid angle; here Not to list them all.

For ease of understanding, the following is an analysis of the principle that the free-form surface 34 in this embodiment achieves higher light intensity uniformity; at the same time, for the convenience of description, the lateral direction of the central axis is referred to as the side for short below:

As shown in FIG. 5 a and FIG. 5 b , the standard curved surface 32 shapes the incident light emitted by the light source 31 into parallel light, that is, all outgoing rays of the standard curved surface 32 are distributed within a solid angle of 0 degrees. Therefore, if the free-form surface 34 changes the angle of incidence of the incident light, the corresponding outgoing light will deviate from 0 degrees; the amount of change (absolute value) of the angle of incidence increases from the central axis of the light source to the side, for example, the amount of change is 20 degrees and 30 degrees in turn , then from the central axial side of the light source, the deviation of the outgoing light from the free-form surface 34 from 0 degrees is also increasing, so that the outgoing light from the free-form surface 34 can be distributed within a predetermined solid angle; when the light of the incident light produced by the light source 31 When the intensity distribution decreases from the central axis to the side, the uniformity of the light intensity distribution of the outgoing light from the free-form surface 34 within a predetermined solid angle can be improved by decreasing the rate of change of the incident angle of the free-form surface 34 to the incident light. .

For example, in order to simplify the description of the problem, explain it in a two-dimensional case. At this time, the solid angle is simplified as an angle. At the same time, the angle change of the outgoing light of the free-form surface 34 can be approximately regarded as the change of the incident light angle of the free-form surface 34. . As shown in FIG. 5 b , the incident light generated by the light source is distributed within 0-40 degrees, and the predetermined angle of the outgoing light from the free-form surface 34 is within 0-30 degrees. Since the light intensity of the incident light generated by the light source is greater at the central axis of the light source, for example, the luminous flux of the incident light within 0-20 degrees is twice the luminous flux within 20-40 degrees. In order to make the light intensity of the outgoing light of the free-form surface 34 uniform within 0-30 degrees, then, the outgoing light corresponding to the incident light within 0-20 degrees should be distributed within 0-20 degrees, that is, the outgoing light corresponding to the incident light of 20 degrees The light should be 20 degrees away from the central axis, and the incident light within 20-40 degrees should be distributed within 20-30 degrees, that is, the incident light of 40 degrees should be 30 degrees away from the central axis. Therefore, the variation of the incident angle of the incident light of 20 degrees is 20, because the variation of the incident angle of the incident light of 0 degrees is 0, the average rate of change of the variation of the incident angle of the incident light within 0-20 degrees is about (20 -0)/(20-0)=1; the incident angle change of 40-degree incident light is 30, because the incident angle change of 20-degree incident light is 20, then the incident angle of 20-40-degree incident light changes The average change rate of the amount is about (30-20)/(40-20)=0.5, which is 1/2 of the average change rate of the incident angle transformation amount of the incident light within 0-20 degrees. It can be seen that the uniformity of light intensity distribution of the outgoing light from the free-form surface 34 within a predetermined solid angle can be improved by gradually decreasing the rate of change of the incident angle of the free-form surface 34 to the incident light.

It is easy to understand that the degree of decline of the above-mentioned rate of change is different, and the uniformity of the light intensity distribution of the outgoing light of the free-form surface 34 in the predetermined solid angle is also different. Those skilled in the art can according to the different requirements for uniformity, through simulation experiments, etc. Determines how much this rate of change decreases. It is worth noting that when the rate of change decreases too much, the outgoing light of the free-form surface 34 will be strong in a large angle range, and the light intensity will be small in a small angle range, which will cause the light intensity distribution of the incident light to be higher than that produced by the light source. It is more uneven, so the decreasing degree of the above-mentioned rate of change needs to be controlled within a certain range. Of course, this point can also be easily determined by simulation experiments by those skilled in the art.

The principle that the free-form surface 33 achieves higher light intensity uniformity is the same as that of the free-form surface 34 , and will not be analyzed here.

In this embodiment, the free-form surface is obtained by deforming the standard curved surface by using the deformation law in the above-mentioned technical solution. The free-form surface can shape the incident light distribution of the first light spot from the center to the outside to have a better Uniform light intensity distribution. Compared with the prior art, the free-form surface of the present invention does not need to be composed of multiple microlenses, thus avoiding the above-mentioned problem of reduced light utilization rate caused by crosstalk and the like, and has the advantages of simple structure and high light utilization rate.

Please refer to FIG. 6 . FIG. 6 is an optical path diagram of another embodiment of the light homogenizing element of the present invention. As shown in Figure 6, in the present embodiment, the homogenizing element of the present invention includes a free-form surface 53 (or 54) for shaping the incident light generated by the light source 51, and the incident light is aligned with the central axis of the light source 51. The first light spot is formed on a vertical plane, and the illuminance distribution of the first light spot is weakened from the center to the outside. The free curved surface 53 (or 54 ) is obtained by deforming a standard curved surface 52 at a predetermined position in the direction of the central axis of the light source 51 .

The difference between this embodiment and the embodiment shown in Figure 5a includes the following two points:

(1) In this embodiment, both the standard curved surface 52 and the free curved surface 53 (or 54 ) are reflective curved surfaces. Specifically, the standard curved surface 52 is a parabola capable of shaping the incident light generated by the light source 51 into parallel light.

(2) In the embodiment shown in Fig. 5a, along the direction from the central axis of the light source 31 to the side, whether it is the direction from a to b or the direction from a to c, the incident light generated by the light source 31 is free The difference between the angle of incidence on the curved surface 33 and the angle of incidence of the incident light on the standard curved surface 32 all maintains a positive sign; along the direction from the central axis of the light source 31 to the side, no matter the direction from d to e, or From the direction d to f, the difference between the incident angle of the incident ray generated by the light source 31 on the free-form surface 34 and the incident angle of the incident ray on the standard curved surface 32 maintains a negative sign. In this embodiment, along the direction from the central axis of the light source 51 to the side, that is, the direction from a to b and the direction from a to c, the incident angle of the incident light generated by the light source 51 on the free-form surface 53 is the same as The difference between the incident angles of the incident light on the standard curved surface 52 maintains a negative sign and a positive sign respectively; along the direction from the central axis of the light source 51 to the side, that is, the direction from d to e and the direction from d to f , the difference between the incident angle of the incident ray generated by the light source 51 on the free-form surface 54 and the incident angle of the incident ray on the standard curved surface 52 maintains a positive sign and a negative sign, respectively.

For example, along the direction from a to b, the difference between the incident angle of the incident light generated by the light source 51 on the free-form surface 53 and the incident angle of the incident light on the standard curved surface 52 decreases continuously from -1 degree to -10 degrees , and the decreasing rate gradually decreases; along the direction from a to c, the difference between the incident angle of the incident light generated by the light source 51 on the free-form surface 53 and the incident angle of the incident light on the standard curved surface 52 is 1 degrees to 10 degrees, and the rate of increase gradually decreases; along the direction from d to e, the incident angle of the incident light produced by the light source 51 on the free-form surface 54 is different from the incident angle of the incident light on the standard curved surface 52 The difference of the angle increases continuously from 1 degree to 10 degrees, and the rate of increase gradually decreases; along the direction from d to f, the incident light angle produced by the light source 51 on the free-form surface 54 is the same as that of the incident light on the free-form surface 54 The difference of the incident angle on the standard curved surface 52 decreases continuously from -1 degree to -10 degree, and the decreasing rate gradually decreases.

Please refer to FIG. 7 . FIG. 7 is an optical path diagram of another embodiment of the light homogenizing element of the present invention. As shown in Fig. 7, in this embodiment, the light homogenizing element of the present invention includes a free-form surface 72 (or 73) for shaping the incident light generated by the light source (not shown in the figure), and the incident light is in contact with the light source The first light spot is formed on a plane perpendicular to the central axis of the first light spot, and the illuminance distribution of the first light spot is weakened from the center to the outside. The free curved surface 72 (or 73) is obtained by deforming a standard curved surface 71 at a predetermined position in the direction of the central axis of the light source.

The difference between this embodiment and the embodiment shown in FIG. 6 is that: in this embodiment, the incident light on the free-form surface 72 (or 73) is a parallel light; the standard curved surface 71 is a reflection plane that can fold the incident light.

Please refer to FIG. 8 . FIG. 8 is an optical path diagram of another embodiment of the light homogenizing element of the present invention. This embodiment includes a free-form surface 91, and the free-form surface 91 is a specific form of the free-form surface in the embodiment shown in FIG. 5a or FIG. 6 .

As shown in FIG. 8 , in this embodiment, the light source system includes a point light source O and a free-form surface 91 . The set of outgoing rays from the free-form surface 91 is 92 . The distance from a point on the free-form surface 91 to the point light source O is obtained by numerically solving the following formula:

$\left\{\begin{array}{c}\frac{<span\; class="notranslate">\; |</span>{<span\; class="notranslate">\; \&PartialD;</span>}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>{<span\; class="notranslate">\; \&PartialD;</span>}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}{\mathrm{<span\; class="notranslate">\; det</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}\\ \mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\end{array}\right.<span\; class="notranslate">\; ;</span>$

$\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; [</span><span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}\frac{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}{\sqrt{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; +</span>\sqrt{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; ]</span>\frac{<span\; class="notranslate">\; (</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&rho;m</span>}<span\; class="notranslate">\; )</span>}{\sqrt{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; ,</span>$

Wherein, i(m) is the light intensity distribution of the incident light produced by the point light source O, m is the unit vector from the point light source O to the point on the free-form surface 91, and ρ(m) is the direction from the point light source O to the free-form surface 91 in the m direction. The distance of the point on the curved surface 91 can be used to express the free-form surface 91, m ₀ is a certain direction selected, ρ ₀ is the distance from the point light source to the point on the free-form surface 91 in the m ₀ direction, f(T(m) ) is the light intensity distribution of the outgoing light of the free-form surface 91 in a predetermined solid angle, n1 is the refractive index _of the medium where the incident light is located, and _n2 is the refractive index of the medium where the outgoing light of the free-form surface 91 is located, e=e _ij dt ⁱ dt ^j represents the first basic type of the surface, e ^ij =(e _ij ) ^-1 , t _i and t _j are two parameters in the parametric equation of the surface respectively. When the free-form surface 91 is a reflective surface, n ₁ =-n ₂ .

Preferably, the predetermined solid angle is a predetermined rectangular solid angle, and f(T(m)) is the uniform light intensity distribution of the outgoing light from the free-form surface within the predetermined rectangular solid angle, so as to adapt to the rectangular display screens widely used in the current display field . In this case, more preferably, both the major angle and the minor angle of the solid angle of the predetermined rectangle are greater than or equal to 0.01 degrees and less than or equal to 3 degrees. Certainly, the predetermined solid angle may also be other types of solid angles, for example, the solid angle of a cone whose base is a regular triangle, regular hexagon or ellipse.

In addition, m ₀ is preferably the direction of the central axis of the point light source for ease of calculation. At this time, ρ ₀ is preferably equal to or greater than 2 mm and equal to or less than 50 mm.

The light intensity distribution of the incident light generated by the point light source O can be various. In an alternative embodiment of the present invention, the light intensity distribution of the incident light generated by the point light source O may be an elliptical Gaussian light intensity distribution, namely $i\left(m\right)=I_0\exp \left[(-\frac{{\mathrm{\&theta;}}^2}{2})(\frac{{\cos }^2\mathrm{\&phi;}}{{\mathrm{\&sigma;}}_x^2}+\frac{{\sin }^2\mathrm{\&phi;}}{{\mathrm{\&sigma;}}_{\mathrm{the\; y}}^2})\right],$ Where I ₀ is the light intensity in the direction of the central axis of the point light source O, (θ, φ) is the point corresponding to the unit vector m in spherical coordinates with the point light source O as the origin and the central axis direction of the point light source O as the polar axis coordinates, σ _x is the light intensity in the plane where the major axis and polar axis of the ellipse Gaussian is reduced to I ₀ σ _y is the plane where the minor axis and polar axis of the elliptical Gaussian are located, and the light intensity is reduced to I ₀ time angle. In another alternative embodiment of the present invention, the light intensity distribution of the incident light generated by the point light source O is a Lambertian light intensity distribution, that is, i(m)=I ₀ cos(θ), where I ₀ is the point light source The light intensity in the direction of the central axis of O, θ is the angle between the unit vector m and the direction of the central axis.

The foregoing embodiments illustrate that the uniformity element is a free-form surface capable of achieving high uniformity of light intensity. The following describes in detail that the uniformity element is a free-form surface capable of achieving high uniformity of illuminance.

Please refer to FIG. 9 . FIG. 9 is an optical path diagram of another embodiment of the light homogenizing element of the present invention. As shown in FIG. 9 , in this embodiment, the uniform light element includes a free-form surface 43 for shaping the incident light generated by the light source 41 . The light source 41 may be a point light source, that is, the incident light incident on the free-form surface 43 is directly generated by the point light source. The incident light generated by the light source 41 forms a first light spot on a plane perpendicular to the central axis of the light source 41 , and the illuminance distribution of the first light spot weakens from the center to the outside. The illuminance distribution of the first light spot may be an elliptical Gaussian distribution or a Lambertian distribution. The free curved surface 43 is obtained by deforming a standard curved surface 42 at a predetermined position in the direction of the central axis of the light source 41 .

The difference between this embodiment and the embodiment shown in Figure 5 includes the following two points:

(1) In this embodiment, the standard curved surface 42 is a curved surface capable of converging the incident light generated by the light source 41 at the center point of a predetermined area, specifically a Cartesian ellipse. The predetermined area can be set according to actual needs, and can be of various types, for example, a rectangular area, an elliptical area, a triangular area, or a regular hexagonal area with a specific size and shape.

(2) In addition to the central axis direction of the light source 41, along the direction from the central axis to the side (including the direction from d to e, or the direction from d to f), the incident light generated by the light source 41 is on the free-form surface The difference between the angle of incidence on 43 and the angle of incidence of the incident ray on the standard curved surface 42 keeps the same sign (specifically, both keep a negative sign), and the angle of incidence of the incident ray produced by the light source 41 on the free-form surface 43 is the same as the angle of incidence of the incident ray on the standard curved surface 42. The absolute value of the difference of the angle of incidence on the standard curved surface 42 increases monotonically, and the rate of change of the absolute value of the difference between the angle of incidence of the incident light on the free-form surface 43 and the difference of the angle of incidence of the incident light on the standard curved surface 42 Decrease, so that the outgoing light from the free-form surface 43 has a more uniform illuminance distribution than the incident light generated by the light source 41 in the predetermined area. That is to say, in this embodiment, the free-form surface 43 is to achieve a more uniform illuminance distribution, not light intensity distribution.

The outgoing light of the free-form surface 43 has a more uniform illuminance distribution than the incident light produced by the light source 41 in the predetermined area, which means that the illuminance uniformity of the outgoing light of the free-form surface 43 in the predetermined area is higher than that of the incident light produced by the light source 41 in the predetermined area. The uniformity of illumination within is higher. The uniformity of illuminance in the predetermined area can be expressed in various ways, for example, it can be the ratio of the minimum value of illuminance in the predetermined area to the average value of illuminance in the predetermined area; The ratio of the average value of illuminance; it can also be the ratio of the average value of illuminance in the predetermined area to the difference between the maximum value of illuminance and the minimum value of illuminance in the predetermined area; it will not be listed here. The principle that the free-form surface 43 achieves higher illuminance uniformity is the same as that of the free-form surface 34 , and will not be analyzed here.

It is easy to understand that in this embodiment, the standard curved surface 42 can also be deformed to obtain another free curved surface, and the incident angle of the incident light generated by the light source 41 on the free curved surface is equal to the incident angle of the incident light on the standard curved surface 42. The differences keep the same sign (specifically, they all keep positive sign), and the free-form surface is similar to the free-form surface 34 in the embodiment shown in FIG. 5 .

In this embodiment, the free-form surface is obtained by deforming the standard curved surface by using the deformation law in the above-mentioned technical solution. The free-form surface can shape the incident light distribution of the first light spot from the center to the outside to have a better Uniform illuminance distribution. Compared with the prior art, the free-form surface of the present invention does not need to be composed of multiple microlenses, thus avoiding the above-mentioned problem of reduced light utilization rate caused by crosstalk and the like, and has the advantages of simple structure and high light utilization rate.

Please refer to FIG. 10 . FIG. 10 is an optical path diagram of another embodiment of the light homogenizing element of the present invention. As shown in FIG. 10, in this embodiment, the homogenizing element includes a free-form surface 63 (or 64) for shaping the incident light generated by the light source 61. The incident light is on a plane perpendicular to the central axis of the light source 61. The first light spot is formed on the upper surface, and the illuminance distribution of the first light spot is weakened from the center to the outside. The free curved surface 63 (or 64 ) is obtained by deforming a standard curved surface 62 at a predetermined position in the direction of the central axis of the light source 61 .

The difference between this embodiment and the embodiment shown in Fig. 9 is that in this embodiment, the free-form surface 63 (or 64) and the standard curved surface 52 are both reflective curved surfaces, and the standard curved surface 52 is a surface that can converge incident light rays in a predetermined area. The center point of the ellipsoid.

In this embodiment, along the direction from the central axis of the light source 61 to the two sides, that is, the direction from the central axis to the right side and the direction from the central axis to the left side, the incident light generated by the light source 61 is The difference between the incident angle on the free-form surface 63 and the incident angle on the standard curved surface 62 maintains a negative sign and a positive sign, respectively. Along the direction from the central axis of the light source 61 to the two sides, that is, the direction from the central axis to the right side and the direction from the central axis to the left side, the incident light generated by the light source 61 on the free-form surface 64 The difference between the incident angle and the incident angle of the incident ray on the standard curved surface 62 maintains a positive sign and a negative sign, respectively.

Please refer to FIG. 11 . FIG. 11 is a light path diagram of another embodiment of the light homogenizing element of the present invention. As shown in FIG. 11 , in this embodiment, the homogenizing element includes a free-form surface 82 (or 83 ) for shaping the incident light generated by the light source (not shown in the figure), and the incident light is aligned with the central axis of the light source 81 The first light spot is formed on a vertical plane, and the illuminance distribution of the first light spot is weakened from the center to the outside. The free curved surface 82 (or 83) is obtained by deforming a standard curved surface 81 at a predetermined position in the direction of the central axis of the light source.

The difference between this embodiment and the embodiment shown in FIG. 10 is: in this embodiment, the incident light rays on the free-form surface 82 (or 83) are parallel light rays, and the standard curved surface 81 is the central point that can converge the incident light rays in a predetermined area. of paraboloids.

In this embodiment, along the direction from the central axis of the light source to the two sides, that is, the direction from the central axis to the right side and the direction from the central axis to the left side, the incident light generated by the light source is on the free-form surface The difference between the angle of incidence on 82 and the angle of incidence of the incident ray on the standard curved surface 81 maintains a minus sign and a plus sign, respectively. Along the direction from the central axis of the light source to the two sides, that is, the direction from the central axis to the right side and the direction from the central axis to the left side, the incident angle of the incident light generated by the light source on the free-form surface 83 The difference from the incident angle of the incident ray on the standard curved surface 81 maintains a positive sign and a negative sign, respectively.

In addition, similar to the embodiment shown in Fig. 5a and Fig. 6, the free-form surface in the embodiment shown in Fig. 9 and Fig. 10 can also adopt the specific expression form of the embodiment shown in Fig. 8 . As shown in FIG. 8, when the embodiment shown in FIG. 8 is a specific form of expression of the embodiment shown in FIG. 9 and FIG. 10, the distance from the point on the free-form surface 91 to the point light source O is obtained by numerically solving the following formula:

$\left\{\begin{array}{c}\frac{<span\; class="notranslate">\; |</span>{<span\; class="notranslate">\; \&PartialD;</span>}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>{<span\; class="notranslate">\; \&PartialD;</span>}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}{\mathrm{<span\; class="notranslate">\; det</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}\\ \mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\end{array}\right.<span\; class="notranslate">\; ;</span>$

$\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; [</span><span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}\frac{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}{\sqrt{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; +</span>\sqrt{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; ]</span>\frac{<span\; class="notranslate">\; (</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&rho;m</span>}<span\; class="notranslate">\; )</span>}{\sqrt{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; ,</span>$

Wherein, i(m) is the light intensity distribution of the incident light produced by the point light source O, m is the unit vector from the point light source O to the point on the free-form surface 91, and ρ(m) is the direction from the point light source O to the free-form surface 91 in the m direction. The distance of the point on the curved surface 91 can be used to express the free-form surface 91, m ₀ is a certain direction selected, ρ ₀ is the distance from the point light source to the point on the free-form surface 91 in the m ₀ direction, f(T(m) ) is the illuminance distribution of the outgoing light of the free-form surface 91 in a predetermined area, n ₁ is the refractive index of the medium where the incident light is located, n ₂ is the refractive index of the medium where the outgoing light of the free-form surface 91 is located, e=e _ij dt ⁱ dt ^j represents the first basic type of surface, e ^ij ＝(e _ij ) ^-1 , t _i and t _j are two parameters in the parametric equation of the surface respectively. When the free-form surface 91 is a reflective surface, n ₁ =-n ₂ .

It has been mentioned in the embodiment shown in FIG. 9 that the predetermined area can be set according to actual needs, and there can be multiple types. Preferably, the predetermined area is a predetermined rectangular area, and f(T(m)) is the uniform illuminance distribution of the outgoing light from the free-form surface in the predetermined rectangular area, so as to adapt to rectangular display screens widely used in the current display field. At this time, more preferably, the distance between the predetermined rectangular area and the light source O is greater than 10 mm and less than 500 mm, and the length and width of the predetermined rectangular area are both greater than or equal to 1 mm and less than or equal to 5 mm.

In addition, m ₀ is preferably the direction of the central axis of the point light source for ease of calculation. At this time, ρ ₀ is preferably equal to or greater than 2 mm and equal to or less than 50 mm.

The light intensity distribution of the incident light generated by the point light source O can be various. In an alternative embodiment of the present invention, the light intensity distribution of the incident light generated by the point light source O may be an elliptical Gaussian light intensity distribution, namely $i\left(m\right)=I_0\exp \left[(-\frac{{\mathrm{\&theta;}}^2}{2})(\frac{{\cos }^2\mathrm{\&phi;}}{{\mathrm{\&sigma;}}_x^2}+\frac{{\sin }^2\mathrm{\&phi;}}{{\mathrm{\&sigma;}}_{\mathrm{the\; y}}^2})\right],$ Where I ₀ is the light intensity in the direction of the central axis of the point light source O, (θ, φ) is the point corresponding to the unit vector m in spherical coordinates with the point light source O as the origin and the central axis direction of the point light source O as the polar axis coordinates, σ _x is the light intensity in the plane where the major axis and polar axis of the ellipse Gaussian is reduced to I ₀ σ _y is the plane where the short axis and polar axis of the elliptical Gaussian are located, and the light intensity is reduced to I ₀ time angle. In another alternative embodiment of the present invention, the light intensity distribution of the incident light generated by the point light source O is a Lambertian light intensity distribution, that is, i(m)=I ₀ cos(θ), where I ₀ is the point light source The light intensity in the direction of the central axis of O, θ is the angle between the unit vector m and the direction of the central axis.

Various implementation forms of the light source system of the present invention will be listed below.

Please refer to FIG. 12 , which is an optical path diagram of an embodiment of the light source system of the present invention. As shown in FIG. 12 , in this embodiment, the light source system includes a light source 121 , a uniform light element including a transmission curved surface 122 and a transmission curved surface 124 , and an imaging lens 123 .

The light source 121 is specifically a single point light source 121, and the light generated by it forms a first light spot on a plane perpendicular to the central axis of the light source 121, and the illuminance distribution of the first light spot decreases from the center to the outside. Specifically, the light intensity distribution of the light generated by the light source 121 may be an elliptical Gaussian light intensity distribution, or a Lambertian light intensity distribution.

The homogenizing element is a lens (not shown), and the curved transmission surface 122 and the curved transmission surface 124 are two surfaces of the lens. The transmission curved surface 124 is set to be perpendicular to the direction of the incident light so as not to change the direction of the incident light, while the transmission curved surface 122 is a free-form surface in the embodiment shown in FIG. Uniform light intensity distribution.

Preferably, the light beam irradiated by the light source 121 on the transmission curved surface 122 is shaped by the transmission curved surface 122, and its light intensity is uniformly distributed within a rectangular solid angle, and then passes through the imaging lens 123, and the light beam is within a predetermined rectangular area of the focal plane of the imaging lens 123 A second light spot S with uniform illuminance distribution is formed.

Please refer to FIG. 13 , which is a light path diagram of another embodiment of the light source system of the present invention. As shown in Figure 13, the difference between this embodiment and the embodiment shown in Figure 12 is that this embodiment includes a plurality of point light sources and uniform light elements corresponding to the multiple point light sources, and each light uniform element The light of the corresponding point light source is uniformly distributed in the predetermined rectangular solid angle and falls on different positions of the same imaging lens, and the outgoing light of each uniform light element forms the same The second spot of rectangular uniform illumination distribution.

Specifically, this embodiment includes three point light sources 141, 142, and 143, and three uniform light elements respectively corresponding to the three point light sources. , the transmission curved surfaces 150 and 146 . Wherein the transmission curved surfaces 148, 149, 150 are set to be perpendicular to the direction of incident light. The shapes of the transmission curved surfaces 144 , 145 , and 146 at different positions are exactly the same, and each transmission curved surface shapes the incident light into a light beam with uniform distribution of light intensity within a predetermined rectangular solid angle. The outgoing light from the transmission curved surfaces 144 , 145 , 146 at different positions passes through the imaging lens 147 to form a second light spot with the same rectangular uniform illuminance distribution at the same position on the focal plane of the imaging lens 147 .

Please refer to FIG. 14 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 14 , this embodiment includes a light source 131 , a uniform light element 132 and an imaging lens 133 . The difference between this embodiment and the embodiment shown in FIG. 12 is that the dodging element in this embodiment is a reflective curved surface 132 , and the reflective curved surface 132 is the free curved surface in the embodiment shown in FIG. 6 .

Please refer to FIG. 15 , which is an optical path diagram of another embodiment of the light source system of the present invention. The difference between this embodiment and the embodiment shown in Figure 14 is that this embodiment includes a plurality of point light sources and dodging elements corresponding to the plurality of point light sources respectively, and each dodging element controls the corresponding point light source The light is formed to uniformly distribute the light intensity within the predetermined rectangular solid angle and fall on different positions of the same imaging lens, and the outgoing light of each uniform light element forms the same rectangular uniform illuminance distribution at the same position of the focal plane of the imaging lens. Second spot.

Specifically, this embodiment includes three point light sources 151 , 152 , and 153 , and three uniform light elements respectively corresponding to the three point light sources, and the three light uniform elements respectively include reflective curved surfaces 154 , 155 , and 156 . The reflective curved surfaces 154 , 155 , and 156 at different positions have the same shape and the same orientation, and each shape the incident light into a light beam with uniform distribution of light intensity within a predetermined rectangular solid angle. The outgoing light from the reflective curved surfaces 154 , 155 , 156 at different positions passes through the imaging lens 157 , and forms the same rectangular second light spot with uniform illuminance distribution at the same position on the focal plane of the imaging lens 157 .

Please refer to FIG. 16 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 16, in this embodiment, the light source system includes point light sources 161, 162, and reflective curved surfaces 163, 166 respectively corresponding to the point light sources 161, 162. The shapes of the reflective curved surfaces 163, 166 at different positions are exactly the same. The light source system further includes reflective planes 164 , 165 and an imaging lens 167 . The reflective curved surfaces 163 and 166 respectively shape the light generated by the point light sources 161 and 162 , and the reflective planes 164 and 165 respectively reflect the outgoing light of the curved surfaces 163 and 166 to perform optical path folding. The light emitted from the reflection planes 164 and 165 passes through the imaging lens 167 and forms a second light spot with the same rectangular uniform illumination distribution at the same position on the focal plane of the imaging lens 167 . Wherein, the reflective curved surfaces 163 and 166 are free curved surfaces in the embodiment shown in FIG. 6 .

In this embodiment, the orientations of the point light sources 161 and 162 are consistent, thus having the advantage of being easy to install. Moreover, the two reflective curved surfaces 163 and 166 are arranged opposite to each other, and the reflective planes are arranged opposite to the corresponding reflective curved surfaces. The smaller interval makes the light source system more compact and improves the utilization rate of the imaging lens 167 .

In addition, multiple sets of light sources, reflective curved surfaces, and reflective planes can be arranged and arranged along the direction perpendicular to the cross-section as shown in FIG. 16 , so as to increase the optical power density of the light source system.

Please refer to FIG. 17 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 17 , in this embodiment, the light source system includes point light sources 171 , 172 , reflective curved surfaces 173 , 174 respectively corresponding to the point light sources 171 , 172 , and an imaging lens 175 . The difference between this embodiment and the embodiment shown in Fig. 16 is that: the point light sources 171, 172 in this embodiment are arranged facing each other, and the reflective curved surfaces 173, 174 are arranged opposite to each other and seamlessly spliced, so that the reflective curved surfaces 173, 174 Part of the emitted light overlaps or only has a small interval, so that the light source system is more compact and the utilization rate of the imaging lens 167 is improved.

In addition, multiple sets of light sources and reflective curved surfaces can be arranged and arranged along the direction perpendicular to the cross-section as shown in FIG. 17 , so as to increase the optical power density of the light source system.

Please refer to FIG. 18 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in Figure 18, in this embodiment, the light source system includes multiple point light sources 211, 212, 213, multiple reflective curved surfaces 214, 215, 216 corresponding to the multiple point light sources 211, 212, 213 respectively, and Reflective planes 217 , 218 , 219 corresponding to the plurality of reflective curved surfaces 214 , 215 , 216 . The reflective curved surfaces 214, 215, and 216 are free curved surfaces in the embodiment shown in FIG. 6 . The point light sources 211 , 212 , 213 , the reflective curved surfaces 214 , 215 , 216 and the reflective planes 217 , 218 , 219 are all oriented in the same direction, thus having the advantage of being easy to install. The outgoing light rays from the reflective curved surfaces 214, 215, and 216 respectively change the direction of the light rays through the reflective planes 217, 218, and 219 to propagate upward, so that the outgoing light rays from each reflective curved surface 214, 215, and 216 are not blocked by each other, and can be conveniently made into two dimension array.

Please refer to FIG. 19 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 19 , on the basis of the embodiment shown in FIG. 18 , this embodiment adds reflective planes 227 and 228 arranged in a certain gradient to compress the size of the outgoing light beam of the light source system.

Please refer to Figs. 20-21, Figs. 20-21 are light path diagrams of another embodiment of the light source system of the present invention. 20 is a side view, and FIG. 21 is a top view. As shown in FIGS. There is a uniform light intensity distribution within a predetermined rectangular solid angle, and the outgoing light rays of each reflective curved surface form a second light spot with the same rectangular uniform illuminance distribution at the same position on the focal plane of the imaging lens 231 . The reflective curved surfaces 237, 238, 238', 239, 241, 241', 242, 243, 243' are arranged in a certain gradient or staggered in the side view and the top view, so as to compress the size of the light beam emitted by the light source system in two dimensions . At the same time, due to the staggered arrangement, the distance between the point light sources increases, which is beneficial to heat dissipation. In the side view, the dashed and solid lines represent the reflective surface and the light source in different planes, respectively. Wherein, the reflective curved surfaces 237, 238, 238', 239, 241, 241', 242, 243, 243' are free curved surfaces in the embodiment shown in Fig. 6 .

Please refer to FIG. 22 , which is an optical path diagram of another embodiment of the light source system of the present invention.

As shown in FIG. 22 , in this embodiment, a light source (not shown) provides collimated light beams, and multiple reflective curved surfaces 201 , 202 , 203 are free curved surfaces in the embodiment shown in FIG. 7 , and have the same shape. The light emitted from the reflective curved surfaces 201 , 202 , 203 passes through an imaging lens 204 and forms a second light spot with the same rectangular uniform illumination distribution at the same position on the focal plane of the imaging lens 204 . Preferably, the reflective curved surfaces 201, 202, 203 are arranged in a certain gradient, so that the outgoing light beam of the light source system has a smaller size.

Please refer to FIG. 23 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 23 , in this embodiment, the light source system includes a point light source 91 , a uniform light element composed of a transmission curved surface 92 and a transmission curved surface 93 , and the light generated by the point light source 91 is directly emitted to the transmission curved surface 93 . The uniform light element is a lens (not marked), and the transmission curved surface 92 and the transmission curved surface 93 are two surfaces of the lens, and the transmission curved surface 93 is set to be perpendicular to the direction of the incident light, so the direction of the light does not change. The transmission curved surface 92 is shown in Figure 9 Freeform surface in the illustrated embodiment. The light beam irradiated by the light source 91 on the uniform light element is shaped by the transmission curved surface 92 to form a second spot S with uniform illuminance distribution in a predetermined rectangular area of the target plane.

Please refer to FIG. 24 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 24 , the light source system of this embodiment includes a point light source 101 and a reflective curved surface 102 , and the reflective curved surface is the free curved surface in the embodiment shown in FIG. 10 . The difference between this embodiment and the embodiment shown in FIG. 23 is that: the uniform light element in this embodiment is a reflective curved surface 102 .

Please refer to FIG. 25 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 25 , in this embodiment, the light source system includes a plurality of point light sources 111 , 112 , 113 arranged in an array, and a plurality of dodging elements corresponding to the point light sources 111 , 112 , 113 respectively. The multiple uniform light elements are lenses, and each lens is composed of transmission curved surfaces 114 and 117 , transmission curved surfaces 115 and 118 , and transmission curved surfaces 116 and 119 . The transmission curved surfaces 117, 118, 119 respectively receive the light generated by the corresponding point light sources, and are arranged to be perpendicular to the direction of the incident light, so that the direction of the incident light does not change. The transmission curved surfaces 114 , 115 , and 116 are free curved surfaces in the embodiment shown in FIG. 9 . The light beams irradiated by each point light source on the corresponding uniform light element are respectively shaped by the transmission curved surfaces 114, 115, 116. A second light spot with the same rectangular uniform illuminance distribution is formed at the same position on the target plane.

Please refer to FIG. 26 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 26 , in this embodiment, the light source system includes a plurality of point light sources 181 , 182 , 183 and a reflective curved surface 184 , which is a free curved surface in the embodiment shown in FIG. 11 . The light source system further includes a plurality of collimating elements 185, 186, 187 corresponding to the plurality of point light sources 181, 182, 183, respectively. The light emitted by the multiple point light sources 181 , 182 , 183 passes through the collimating elements 185 , 186 , 187 respectively, and emerges as multiple beams of parallel light. Each beam of parallel light is shaped by the reflective curved surface 184 and together forms a rectangular second light spot with uniform illumination distribution on the target plane.

In this embodiment, when the light distribution of the point light source is an elliptical Gaussian distribution, the light path reflected by the reflective curved surface 184 may be in the same plane as the long axis or short axis of the ellipse formed by the light distribution of the point light source. Preferably, the light path reflected by the reflective curved surface 184 is in the same plane as the minor axis of the ellipse. At this time, since the incident light divergence angle of the reflective curved surface 184 in this plane is small, the outgoing light and the incident light are more easily separated.

Please refer to FIG. 27 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 27 , the light source system includes a light source providing multiple collimated light beams, and a plurality of different reflective curved surfaces 191 , 192 , 193 respectively corresponding to the multiple collimated light beams. Wherein, the reflective curved surfaces 191 , 192 , and 193 are free curved surfaces in the embodiment shown in FIG. 11 . Each reflective curved surface forms the same rectangular light spot with uniform illuminance distribution on the same position of the target plane, and each light spot is superimposed on each other. The reflective curved surfaces 191, 192, 193 are arranged in a certain gradient, so that the outgoing light beam of the light source system has a smaller size.

Please refer to FIG. 28 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 28 , in this embodiment, the light source system includes a point light source 251 and a lens 252 . The lens 252 is composed of a curved surface 254 and a curved surface 253 , and the light generated by the light source 251 is emitted toward the curved surface 253 . The curved surface 254 can be any surface, and the curved surface 253 can be any one of the above-mentioned transmission curved surfaces with light shaping function, such as the free curved surface in the embodiment shown in FIG. 5 or FIG. 9 .

Please refer to FIG. 29 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 29 , in this embodiment, the light source system includes a point light source 261 and a lens 262 . Lens 262 is made up of curved surface 263,264, and curved surface 263 is arranged to be perpendicular to incident light direction, thus does not change incident light direction, and curved surface 264 can be any one in the above-mentioned transmission curved surface with light shaping function, for example Fig. 5 or Fig. The freeform surface in the embodiment shown in 9. The point light source 261 is located outside the lens 262 , and the light generated by the point light source is emitted towards the curved surface 263 and then shaped by the curved surface 264 .

Please refer to FIG. 30 , which is an optical path diagram of another embodiment of the light source system of the present invention. As shown in FIG. 30 , in this embodiment, the light source system includes a point light source 271 and a lens 272 . The lens 272 is made up of curved surfaces 273 and 274. The curved surface 273 can be any one of the above-mentioned transmission curved surfaces with light shaping function, such as the free curved surface in the embodiment shown in FIG. 5 or FIG. The direction is vertical, so that the direction of the incident light is not changed. The point light source 271 is located outside the lens 272 , and the light generated by the point light source is emitted toward the curved surface 273 and is shaped by the curved surface 273 , and the shaped light is then transmitted through the curved surface 274 . In this way, the output light distribution of the entire lens 272 is actually the output light distribution of the curved surface 273 .

In summary, in the present invention, the free-form surface is obtained by deforming on the basis of the standard curved surface by adopting the deformation law in the above-mentioned technical solution. Shaping to have a more uniform light intensity or illuminance distribution. Compared with the prior art, the free-form surface of the present invention does not need to be composed of multiple microlenses, thus avoiding the above-mentioned problem of reduced light utilization rate caused by crosstalk and the like, and has the advantages of simple structure and high light utilization rate.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields, All are included in the scope of patent protection of the present invention in the same way.

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.