Diffusion plate of micro array type

A microlens array in which lenses are arrayed longitudinally and laterally on an array surface, wherein

• when a longitudinal direction and a lateral direction of an array of the lenses are regarded as a longitudinal direction and a lateral direction of a lens among the lenses, the lens has a cross-cylindrical concave lens surface composed of a combination of a concave surface that is cylindrical along the lateral direction throughout sections that are parallel to the longitudinal direction of the lens and are orthogonal to the array surface and a concave surface that is cylindrical along the longitudinal direction throughout sections that are parallel to the lateral direction of the lens and are orthogonal to the array surface, and
• a sag amount is corrected so as to increase an inclination of a rim in each of meridians of the sections parallel to the longitudinal direction and meridians of the sections parallel to the lateral direction,
• wherein the meridians of the sections parallel to the longitudinal direction and of the sections parallel to the lateral direction are each composed of a conic curve of which the sag amount is corrected, and
• wherein
• in the following range of a horizontal coordinate x with its center on an axis of symmetry of the meridians,
• ❘
• "\[LeftBracketingBar]"
• x
• ❘
• "\[RightBracketingBar]"
• ≥
• L
• 2
• -
• Δ
• ⁢
• x
• a sag amount z is expressed as a conic curve corrected as indicated by the following equation,
• z
• =
• (
• (
• 1
• /
• r
• )
• ·
• x
• 2
• 1
• +
• 1
• -
• (
• 1
• +
• k
• )
• ·
• (
• 1
• /
• r
• )
• 2
• ·
• x
• 2
• +
• (
• x
• +
• Δ
• ⁢
• x
• -
• L
• /
• 2
• Δ
• ⁢
• x
• )
• y
• ⁢
• Δ
• ⁢
• z
• )
• wherein, Δx and Δz are expressed as follows,
• Δ
• ⁢
• x
• =
• 0
• .
• 1
• ⁢
• α
• ⁡
• (
• γ
• +
• 1.2
• )
• ⁢
• 0.75
• λr
• 𝔫
• -
• 1
• Δ
• ⁢
• z
• =
• β
• ⁢
• λ
• 2
• L is a width of the meridians, r is a radius of curvature of the conic curve, k is a conic constant, α is a real number no smaller than 0.5 nor greater than 2, β is a real number no smaller than 0.15 nor greater than 0.6, γ is a real number no smaller than 1 nor greater than 10, λ is a wavelength of a visible light ray, and n is an absolute refractive index of the lens.

A concave micromirror array in which concave mirrors are arrayed longitudinally and laterally on an array surface, wherein

• when a longitudinal direction and a lateral direction of the concave mirrors are regarded as a longitudinal direction and a lateral direction of a concave mirror among the concave mirrors, the concave mirror has a cross-cylindrical concave surface composed of a combination of a concave surface that is cylindrical along the lateral direction throughout sections that are parallel to the longitudinal direction of the concave mirror and are orthogonal to the array surface and a concave surface that is cylindrical along the longitudinal direction throughout sections that are parallel to the lateral direction of the concave mirror and are orthogonal to the array surface, and
• a sag amount is corrected so as to increase an inclination of a rim in each of meridians of the sections parallel to the longitudinal direction and meridians of the sections parallel to the lateral direction,
• wherein the meridians of the sections parallel to the longitudinal direction and the meridians of the sections parallel to the lateral direction are each composed of a conic curve of which the sag amount is corrected, and
• wherein
• in the following range of a horizontal coordinate x with its center on an axis of symmetry of the meridians,
• |x|≥L/2−Δx
• a sag amount z is expressed as a conic curve corrected as indicated by the following equation,
• z=((1/r)·x2/1+√{square root over (1−(1+k)·(1/r)2·x2)}+(x+Δx−L/2/Δx)γΔz)
• wherein, Δx and Δz are expressed as follows,
• Δx=0.1α(γ+1.2)√{square root over (0.375λr)}
• Δz=βλ/2
• L is a width of the meridians, α is a real number no smaller than 0.5 nor greater than 2, β is a real number no smaller than 0.15 nor greater than 0.6, γ is a real number no smaller than 1 nor greater than 10, r is a radius of curvature of the conic curve, and λ is a wavelength of a visible light ray.

A convex micromirror array in which convex mirrors are arrayed longitudinally and laterally on an array surface, wherein

• when a longitudinal direction and a lateral direction of the convex mirrors are regarded as a longitudinal direction and a lateral direction of a convex mirror among the convex mirrors, the convex mirror has a cross-cylindrical convex surface composed of a combination of a convex surface that is cylindrical along the lateral direction throughout sections that are parallel to the longitudinal direction of the convex mirror and are orthogonal to the array surface and a convex surface that is cylindrical along the longitudinal direction throughout sections that are parallel to the lateral direction of the convex mirror and are orthogonal to the array surface, and
• a sag amount is corrected so as to increase an inclination of a skirt in each of meridians of the sections parallel to the longitudinal direction and meridians of the sections parallel to the lateral direction,
• wherein the meridians of the sections parallel to the longitudinal direction and the meridians of the sections parallel to the lateral direction are each composed of a conic curve of which the sag amount is corrected, and
• wherein
• in the following range of a horizontal coordinate x with its center on an axis of symmetry of the meridians,
• |x|≥L/2−Δx
• a sag amount z is expressed as a conic curve corrected as indicated by the following equation,
• z=((1/r)·x2/1+√{square root over (1−(1+k)·(1/r)2·x2)}+(x+Δx−L/2/Δx)γΔz)
• wherein, Δx and Δz are expressed as follows,
• Δx=0.1α(γ+1.2)√{square root over (0.375λr)}
• Δz=βλ/2
• L is a width of the meridians, α is a real number no smaller than 0.5 nor greater than 2, β is a real number no smaller than 0.15 nor greater than 0.6, γ is a real number no smaller than 1 nor greater than 10, r is a radius of curvature of the conic curve, and λ is a wavelength of a visible light ray.