Natural Light Homogenization Lighting Device and Method Based on Free-form Surface and Sawtooth Grating

Abstract

The present invention discloses a natural light homogenization lighting device and method based on free-form surface and sawtooth grating, and the device can be used as lighting curtains, indoor shutters, window glasses and the like. The device includes a front surface and a rear surface in an array form, the first surface is a free-form surface array, the second surface is a sawtooth surface array, and the free-form surface array is used for collecting outdoor natural light, and transmitting to the sawtooth surface array through the intermediate medium made of the same material between the two surfaces; and the sawtooth surface array is used for deflecting the incident natural light to the indoor space after being refracted by an inclined surface. The present invention can efficiently collect the natural light incident into the window, disperse the light evenly to all directions indoors, homogenize the indoor lighting, and effectively protect the indoor privacy. The device is thin and easy to mass produce, environmentally friendly and pollution-free.

Claims

1. A natural light homogenization lighting device based on free-form surface and sawtooth grating, comprising a front surface and a rear surface in an array form, the first surface is a free-form surface array, the second surface is a sawtooth surface array, and the free-form surface array is used for collecting outdoor natural light, and transmitting to the sawtooth surface array through the intermediate medium made of the same material between the two surfaces; and the sawtooth surface array is used for deflecting the incident natural light to the indoor space after being refracted by an inclined surface.

2. The natural light homogenization lighting device based on free-form surface and sawtooth grating according to claim 1, wherein the additional phase modulation φ.sub.1 of the free-form surface array to the incident light is expressed as ${\phi }_1=\pm \frac{\pi \left(x_1^2+y_1^2\right)}{\lambda f}-\frac{2\pi }{\lambda }{y}_1.Math.\sin {\theta }_1,$ wherein ϑ.sub.1 represents the incident angle of natural light on the free-form surface, λ represents the central wavelength of the incident light, f represents the equivalent focal length of the free-form surface, x.sub.1 and y.sub.1 are the positions of the incident wavefront of the free-form surface array, while the additional phase modulation φ.sub.2 of the sawtooth surface array to the incident natural light is expressed as ${\phi }_2=-\frac{2\pi }{\lambda }{y}_2.Math.\sin {\theta }_1,$ wherein y.sub.2 represents the position of the incident wavefront of the sawtooth surface array, and ϑ.sub.1 represents the incident angle of incident natural light on the sawtooth surface.

3. The natural light homogenization lighting device based on free-form surface and sawtooth grating according to claim 1, wherein the lens form of the free-form surface array is a convex free-form surface or a concave free-form surface, the convex free-form surface or concave free-form surface faces the incident direction of natural light, and the normal of the lens surface forms an acute angle to the incident angle of natural light.

4. The natural light homogenization lighting device based on free-form surface and sawtooth grating according to claim 3, For the convex free-form surface, an expression of the thickness d.sub.1 at different positions x.sub.1 and y.sub.1 is $d_1\left(x_1,y_1\right)=\frac{1}{n-1}\left(\frac{x_1^2+y_1^2}{r+\sqrt{r^2+\left(x_1^2+y_1^2\right)}}+y.Math.\sin {\theta }_2\right):$ wherein n represents the refractive index, r represents the radius of curvature at the vertex of the convex free-form surface, ϑ.sub.2 represents a surface-type inclination angle of the convex free-form surface, which makes the light propagate in the horizontal direction through refraction, and the radius of curvature is 1-5 times the minimum spacing between the free-form surface and the sawtooth grating; For the concave free-form surface, an expression of the thickness d.sub.2 at different positions x.sub.1 and y.sub.1 on the concave free-form surface array is $d_1\left(x_1,y_1\right)=\frac{1}{n-1}\left(-\frac{x_1^2+y_1^2}{r+\sqrt{r^2-\left(x_1^2+y_1^2\right)}}+y_1.Math.\sin {\theta }_2\right):$ where n represents the refractive index, r represents the radius of curvature at the vertex of the concave free-form surface, and ϑ.sub.2 represents a surface-type inclination angle of the concave free-form surface, which makes the light propagate in the horizontal direction through refraction, and the radius of curvature is 1-5 times the minimum spacing between the free-form surface and the sawtooth grating.

5. The natural light homogenization lighting device based on free-form surface and sawtooth grating according to claim 1, wherein the inclination angle of the sawtooth in the sawtooth surface array is θ, and the range of θ is 20°-70°.

6. The natural light homogenization lighting device based on free-form surface and sawtooth grating according to claim 1, wherein the free-form surface array corresponds to the sawtooth surface array one to one, and the center position of the sawtooth matches the optical axis of the free-form surface lens unit.

7. The natural light homogenization lighting device based on free-form surface and sawtooth grating according to claim 1, wherein the monolithic device material is the high-transmittance material with a transmittance above 85%, including but not limited to glass, resin and transparent plastic.

8. The natural light homogenization lighting device based on free-form surface and sawtooth grating according to claim 1, wherein both front and real surface arrays are in the form of square full-aperture arrays with a filling rate above 95%.

9. A natural light homogenization lighting method based on free-form surface and sawtooth grating, comprising: the outdoor natural light is collected by the free-form surface array, and transmitted to the sawtooth surface array through the intermediate medium made of the same material between the two surfaces; and the sawtooth surface array deflects the incident natural light to the indoor space after being refracted by an inclined surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a schematic structural diagram of an array-type natural light homogenization lighting method based on convex free-form surface and sawtooth grating provided in Embodiment 1 of the present invention.

[0019] In the figure, the natural light at a high angle outdoors disperses horizontally to the indoor space after passing through the device;

[0020] FIG. 2 is a simulation result diagram of an array-type natural light homogenization lighting method based on convex free-form surface and sawtooth grating provided in Embodiment 1 of the present invention.

[0021] In the figure, the first surface of the design device is a convex free-form surface, and the second surface is a sawtooth surface array; the incident natural light at a high angle is collected by the lens array surface, and transmitted to the rear surface through the intermediate medium made of the same material between the two surfaces, and then horizontally dispersed to the indoor space after being refracted by an inclined surface;

[0022] FIG. 3 is a three-dimensional view of a mechanical structure of an array-type natural light homogenization lighting method based on convex free-form surface and sawtooth grating of the present invention, FIG. 3(a) is a convex free-form surface, and FIG. 3(b) is a sawtooth surface array.

[0023] FIG. 4 is a schematic structural diagram of an array-type natural light homogenization lighting method based on concave free-form surface and sawtooth grating provided in Embodiment 3 of the present invention.

[0024] In the figure, the natural light at a high angle outdoors disperses horizontally to the indoor space after passing through the device;

[0025] FIG. 5 is a simulation result diagram of an array-type natural light homogenization lighting method based on concave free-form surface and sawtooth grating provided in Embodiment 3 of the present invention.

[0026] In the figure, the first surface of the design device is a concave free-form surface, and the second surface is a sawtooth surface array; the incident natural light at a high angle is collected by the lens array surface, and transmitted to the rear surface through the intermediate medium made of the same material between the two surfaces, and then horizontally dispersed to the indoor space after being refracted by an inclined surface; and

[0027] FIG. 6 is a three-dimensional view of a mechanical structure of an array-type natural light homogenization lighting method based on concave free-form surface and sawtooth grating of the present invention, FIG. 6(a) is a concave free-form surface, and FIG. 6(b) is a sawtooth surface array.

DETAILED DESCRIPTION

[0028] Exemplary embodiments of the present invention will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implement are described in the description. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such practical embodiment, so as to achieve specific objectives of the developers, such as meeting those restrictions associated with the system and the business, and those restrictions vary with the implementation. It should be also understood that although the development work is likely to be very complex and time-consuming, such development work is merely a routine task for those skilled in the art benefiting from the disclosure of the present invention.

[0029] It should be further noted that, in order to avoid obscuring the present invention due to unnecessary details, only the structure and/or processing steps closely related to the solution according to the present invention are shown in the accompanying drawings, while other details that have little to do with the present invention are omitted.

[0030] Embodiment 1: as shown in FIG. 1, the present embodiment provides an array-type natural light homogenization lighting device with a convex free-form surface and a sawtooth grating, the device includes a front surface and a rear surface in an array form, the first surface is a free-form surface array, and the lens form of the free-form surface array is a convex free-form surface, as shown in FIG. 3(a); while the second surface is a sawtooth surface array, as shown in FIG. (b); the outdoor natural light with a large angle is collected by the surface of the convex free-form surface array, and transmitted to the sawtooth surface array through the intermediate medium made of the same material between the two surfaces, and then deflected to the indoor space after being refracted by an inclined surface. Both the convex free-form surface array and the sawtooth surface array include n unit structures, which correspond to one to one, and n is a natural number greater than or equaling to 1.

[0031] More specifically, both the front surface and the rear surface in an array form realize the modulation of different phases of the incident light separately. Specifically, the additional phase modulation (pi of the first surface to the incident light can be expressed as

[00005]${\phi }_1=-\frac{\pi \left(x_1^2+y_1^2\right)}{\lambda f}-\frac{2\pi }{\lambda }{y}_1.Math.\sin {\theta }_1,$

where ϑ.sub.1 represents the incident angle of natural light on the convex free-form surface, λ represents the incident wavelength, for which the central wavelength is generally taken, f represents the equivalent focal length, and x.sub.1 and y.sub.1 are the positions of the incident wavefront of the convex free-form surface array. The additional phase modulation of the second surface to the incident light can be expressed as

[00006]${\phi }_2=-\frac{2\pi }{\lambda }{y}_2.Math.\sin {\theta }_1,$

where y.sub.2 represents the position of the incident wavefront of the sawtooth surface array, and ϑ.sub.1 represents the incident angle of incident light on the sawtooth surface.

[0032] More specifically, the first surface is a convex free-form surface, the surface form is a spherical surface, a paraboloid or the like, the lens surface faces the incident direction of natural light, the normal of the lens surface forms an acute angle to the incident angle of natural light, and the outdoor natural light incident at a high angle can be dispersed in parallel to all corners indoors through the designed device.

[0033] More specifically, for the convex free-form surface, an expression of the thickness d.sub.1 at different positions (x.sub.1 and y.sub.1) on the convex free-form surface array is

[00007]$d_1\left(x_1,y_1\right)=\frac{1}{n-1}\left(\frac{x_1^2+y_1^2}{r+\sqrt{r^2+\left(x_1^2+y_1^2\right)}}+y.Math.\sin {\theta }_2\right):$

[0034] where n represents the refractive index, r represents the radius of curvature at the vertex of the convex free-form surface, ϑ.sub.2 represents a surface-type inclination angle of the convex free-form surface, which makes the light propagate in the horizontal direction through refraction, and the radius of curvature is 1-5 times the minimum spacing between the free-form surface and the sawtooth grating.

[0035] More specifically, the sawtooth surface array refracts most of the light in the horizontal direction through refraction, and the inclination angle of the sawtooth is 20°-70°.

[0036] More specifically, the convex free-form surface array corresponds to the sawtooth surface array one to one, and the center position of the sawtooth matches the optical axis of the convex free-form surface unit.

[0037] More specifically, the monolithic device material shall be the high-transmittance material with a transmittance above 85%, including but not limited to glass, resin and transparent plastic.

[0038] More specifically, both front and real surface arrays are in the form of square full-aperture arrays with a high filling rate above 95%.

[0039] In order to verify the effect of the above device of the present invention, the radius of curvature of the convex free-form surface r=1 mm, the inclination angle of the convex free-form surface ϑ.sub.2=10°, and the inclination angle of grating on the sawtooth surface ϑ=35°, the free-form surface array corresponds to the sawtooth grating one to one, the spacing between the two planes is 1.5 mm, the size of the array is 1 mm*1 mm, a 5*5 array is selected, ZF6 glass is selected as the material, and the light divergence effect is simulated. The simulation results are shown in FIG. 2.

[0040] Embodiment 2: on the basis of the device in Embodiment 1, the present embodiment provides a natural light homogenization lighting method based on convex free-form surface and sawtooth grating, including: the outdoor natural light is collected by the free-form surface array, and transmitted to the sawtooth surface array through the intermediate medium made of the same material between the two surfaces, and the lens form of the free-form surface array is a convex free-form surface; and the sawtooth surface array deflects the incident natural light to the indoor space after being refracted by an inclined surface.

[0041] Embodiment 3: as shown in FIG. 4, the present embodiment provides an array-type natural light homogenization lighting device with a concave free-form surface and a sawtooth grating, the device includes a front surface and a rear surface in an array form, the first surface is a free-form surface array, and the lens form of the free-form surface array is a concave free-form surface, as shown in FIG. 6(a); while the second surface is a sawtooth surface array, as shown in FIG. 6(b); the outdoor natural light with a large angle is collected by the surface of the concave free-form surface array, and transmitted to the sawtooth surface array through the intermediate medium made of the same material between the two surfaces, and then deflected to the indoor space after being refracted by an inclined surface. Both the concave free-form surface array and the sawtooth surface array include n unit structures, which correspond to one to one, and n is a natural number greater than or equaling to 1.

[0042] More specifically, both the front surface and the rear surface in an array form realize the modulation of different phases of the incident light, separately. Specifically, the additional phase modulation φ.sub.1 of the first surface to the incident light can be expressed as

[00008]${\phi }_1=\frac{\pi \left(x_1^2+y_1^2\right)}{\lambda f}-\frac{2\pi }{\lambda }{y}_1.Math.\sin {\theta }_1,$

where ϑ.sub.1 represents the incident angle of natural light on the concave free-form surface, λ represents the incident wavelength, for which the central wavelength is generally taken, f represents the equivalent focal length, and x.sub.1 and y.sub.1 are the positions of the incident wavefront of the concave free-form surface array. The additional phase modulation φ.sub.2 of the second surface to the incident light can be expressed as

[00009]${\phi }_2=-\frac{2\pi }{\lambda }{y}_2.Math.\sin {\theta }_1,$

where y.sub.2 represents the position of the incident wavefront of the sawtooth surface array, and ϑ.sub.1 represents the incident angle of incident light on the sawtooth surface.

[0043] More specifically, the first surface is a concave free-form surface, the lens surface faces the incident direction of natural light, the normal of the lens surface forms an acute angle to the incident angle of natural light, and the outdoor natural light incident at a high angle can be dispersed in parallel to all corners indoors through the designed device.

[0044] More specifically, for the concave free-form surface, an expression of the thickness d.sub.1 at different positions (x.sub.1 and y.sub.1) on the concave free-form surface array is

[00010]$d_1\left(x_1,y_1\right)=\frac{1}{n-1}\left(-\frac{x_1^2+y_1^2}{r+\sqrt{r^2-\left(x_1^2+y_1^2\right)}}+y_1.Math.\sin {\theta }_2\right):$

where n represents the refractive index, r represents the radius of curvature at the vertex of the concave free-form surface, ϑ.sub.2 represents a surface-type inclination angle of the concave free-form surface, which makes the light propagate in the horizontal direction through refraction, and the radius of curvature is 1-5 times the minimum spacing between the free-form surface and the sawtooth grating.

[0045] More specifically, the sawtooth surface array refracts most of the light in the horizontal direction through refraction, and its inclination angle is 20°-70°.

[0046] More specifically, the concave free-form surface array corresponds to the sawtooth surface array one to one, and the center position of the sawtooth matches the optical axis of the concave free-form surface unit.

[0047] More specifically, the monolithic device material shall be the high-transmittance material with a transmittance above 85%, including but not limited to glass, resin and transparent plastic.

[0048] More specifically, both front and real surface arrays are arrays, and the array form is a square full-aperture array with a high filling rate above 95%.

[0049] In order to verify the effect of the above device of the present invention, the radius of curvature of the concave free-form surface r=−1 mm, the inclination angle of the concave free-form surface θ2=10°, and the inclination angle of grating on the sawtooth surface ϑ=35°, the free-form surface array corresponds to the sawtooth grating one to one, the spacing between the two planes is 1.5 mm, the size of the array is 1 mm*1 mm, a 5*5 array is selected, ZF6 glass is selected as the material, and the light divergence effect is simulated. The simulation results are shown in FIG. 5.

[0050] Embodiment 4: on the basis of the device in Embodiment 3, the present embodiment provides a natural light homogenization lighting method based on concave free-form surface and sawtooth grating, including: the outdoor natural light is collected by the free-form surface array, and transmitted to the sawtooth surface array through the intermediate medium made of the same material between the two surfaces, and the lens form of the free-form surface array is a concave free-form surface; and the sawtooth surface array deflects the incident natural light to the indoor space after being refracted by an inclined surface.

[0051] Although the implementation disclosed in the present invention is described as above, the contents thereof are only the implementation adopted to facilitate the understanding of the technical solutions of the present invention, and are not intended to limit the present invention. Those skilled in the art to which the present invention belongs may make any modifications and changes in the form and details of the implementation without departing from the core technical solution disclosed in the present invention, but the scope of protection limited by the present invention shall still be subject to the scope limited by the appended claims.