An optical sheet (100; 700), with a first surface (11; 711) and a second surface (13; 713), the optical sheet (100; 700), comprising: a light-condensing layer (30; 730) including a plurality of light-condensing portions (31; 731) with a first pitch, the light-condensing portions (31; 731) formed along a first direction of the second surface (13; 713); and a plurality of light-reflecting portions (70; 770) formed on the first surface (11; 711) and spaced apart from each other along the first direction, wherein a groove is formed between each pair of adjacent light-condensing portions (31; 731), wherein an interval distance between the center of each of the plurality of light-condensing portions (31; 731) and an edge of an adjacent light-reflecting portion (70; 770) in the first direction towards the edges of the optical sheet (100; 700) is increasing the more distant the light-reflecting portions (70; 770) are positioned from a center of the first surface (11; 711); wherein the optical sheet (100; 700) has a mirror symmetry in the first direction around the center of the first surface (11; 711), and the light-reflecting portions (70; 770) are separated by a uniform first line width formed in a second pitch that is greater than the first pitch along the first direction from the center of the first surface (11; 711); wherein the light-condensing portions (31; 731) are extended along a second direction perpendicular to the first direction to form a light-condensing stripe pattern, and when a cross-section of the light-condensing portions (31; 731), which is cut in parallel with the first direction, is viewed, portions corresponding to a surface of the light-condensing portions (31; 731) protrude in a normal direction of the second surface (13; 713); and wherein the light-reflecting portions (70; 770) are extended along the grooves that are formed in parallel with the second direction to form a light-reflecting stripe pattern characterized by the optical sheet (100; 700) further comprising: a base layer (10; 710) including the first surface (11; 711) and the second surface (13; 713), and a convex-concave pattern layer (50; 750) disposed between the first surface (11; 711) and the light-reflecting portion (70; 770) to have a protruding portion pattern having the light-reflecting portions (70; 770) formed thereon, wherein a width of the protruding portion pattern is equal to a width of the light-reflecting portion (70; 770), and wherein a refractive index of the convex-concave pattern layer (50; 750) is different from that of the base layer (10; 710) and/or the light-condensing layer (30; 730). a light-condensing layer (30; 730) including a plurality of light-condensing portions (31; 731) with a first pitch, the light-condensing portions (31; 731) formed along a first direction of the second surface (13; 713); and a plurality of light-reflecting portions (70; 770) formed on the first surface (11; 711) and spaced apart from each other along the first direction, wherein a groove is formed between each pair of adjacent light-condensing portions (31; 731), wherein an interval distance between the center of each of the plurality of light-condensing portions (31; 731) and an edge of an adjacent light-reflecting portion (70; 770) in the first direction towards the edges of the optical sheet (100; 700) is increasing the more distant the light-reflecting portions (70; 770) are positioned from a center of the first surface (11; 711); wherein the optical sheet (100; 700) has a mirror symmetry in the first direction around the center of the first surface (11; 711), and the light-reflecting portions (70; 770) are separated by a uniform first line width formed in a second pitch that is greater than the first pitch along the first direction from the center of the first surface (11; 711); wherein the light-condensing portions (31; 731) are extended along a second direction perpendicular to the first direction to form a light-condensing stripe pattern, and when a cross-section of the light-condensing portions (31; 731), which is cut in parallel with the first direction, is viewed, portions corresponding to a surface of the light-condensing portions (31; 731) protrude in a normal direction of the second surface (13; 713); and wherein the light-reflecting portions (70; 770) are extended along the grooves that are formed in parallel with the second direction to form a light-reflecting stripe pattern characterized by the optical sheet (100; 700) further comprising: a base layer (10; 710) including the first surface (11; 711) and the second surface (13; 713), and a convex-concave pattern layer (50; 750) disposed between the first surface (11; 711) and the light-reflecting portion (70; 770) to have a protruding portion pattern having the light-reflecting portions (70; 770) formed thereon, a base layer (10; 710) including the first surface (11; 711) and the second surface (13; 713), and a convex-concave pattern layer (50; 750) disposed between the first surface (11; 711) and the light-reflecting portion (70; 770) to have a protruding portion pattern having the light-reflecting portions (70; 770) formed thereon, wherein a width of the protruding portion pattern is equal to a width of the light-reflecting portion (70; 770), and wherein a refractive index of the convex-concave pattern layer (50; 750) is different from that of the base layer (10; 710) and/or the light-condensing layer (30; 730).