Natural light homogenization lighting device and method based on free-form surface and sawtooth grating

A natural light homogenization lighting device, comprising a front surface array and a rear surface array,

• wherein the front surface array is a free-form surface array, the rear surface array is a sawtooth surface array, and the free-form surface array is configured to collect outdoor natural light, and to transmit the outdoor natural light to the sawtooth surface array through an intermediate medium;
• and
• wherein the sawtooth surface array is configured to deflect the incident natural light to an indoor space after the outdoor natural light is refracted by an inclined surface;
• 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;
• for the convex free-form surface, an expression of the thickness d 1 at different positions x1 and y1 is
• d
• 1
• (
• x
• 1
• ,
• y
• 1
• )
• =
• 1
• n
• ⁢
• (
• x
• 1
• 2
• +
• y
• 1
• 2
• r
• +
• r
• 2
• +
• (
• x
• 1
• 2
• +
• y
• 1
• 2
• )
• +
• y
• ·
• sin
• ⁢
• ϑ
• 3
• )
• :
• wherein n represents the refractive index, r represents the radius of curvature at the vertex of the convex free-form surface, ϑ3 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 d2 at different positions x1 and y1 on the concave free-form surface array is
• d
• 1
• (
• x
• 1
• ,
• y
• 1
• )
• =
• 1
• n
• ⁢
• (
• x
• 1
• 2
• +
• y
• 1
• 2
• r
• +
• r
• 2
• -
• (
• x
• 1
• 2
• +
• y
• 1
• 2
• )
• +
• y
• 1
• ·
• sin
• ⁢
• ϑ
• 3
• )
• :
• where n represents the refractive index, r represents the radius of curvature at the vertex of the concave free-form surface, and ϑ3 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.