Abstract: An optical lens device for a head-mounted display includes a transparent support substrate and a Fresnel lens disposed thereon. The Fresnel lens includes a central lens element and a plurality of prismatic elements arranged relative to the central lens element in a proximal-to-distal manner. Each of the prismatic elements has a base facing toward the support substrate, and a draft facet and a sloped facet extending from the base away from the support substrate to intersect with each other to form an apex. Each of the prismatic elements has a height measured from the base to the apex and not greater than 75 ?m. The base has a width not greater than 250 ?m. A method and a mold for producing the optical lens device are also disclosed.

Abstract: An optical lens device for a head-mounted display includes a transparent support substrate and a Fresnel lens disposed thereon. The Fresnel lens includes a central lens element and a plurality of prismatic elements arranged relative to the central lens element in a proximal-to-distal manner. Each of the prismatic elements has a base facing toward the support substrate, and a draft facet and a sloped facet extending from the base away from the support substrate to intersect with each other to form an apex. Each of the prismatic elements has a height measured from the base to the apex and not greater than 75 ?m. The base has a width not greater than 250 ?m. A method and a mold for producing the optical lens device are also disclosed.

Abstract: A light guide substrate includes first and second triangular prisms juxtaposed to each other on a light exit face thereof. Each of the first and second triangular prisms has a rounded vertex. The number of the first triangular prisms is smaller than the number of the second triangular prisms. Each first triangular prism has a first height from the light exit face. Each second triangular prisms has a second height from the light exit face. The second height is between 20 and 90 percent of the first height. A backlight module includes the aforesaid light guide substrate, a reverse prism sheet disposed on the light guide substrate, and a light emitting unit to emit light rays into the light substrate.