Abstract: An optical device and the prism module thereof are provided. The prism module includes a first prism, a second prism, and a third prism. The second prism is disposed beside the first prism. The third prism is adhered to the second prism. First light enters the first prism, is reflected plural times in the first prism, enters the second prism, and is emitted from the second prism. Second light enters the second prism, is reflected plural times in the second prism, and is emitted from the second prism. Third light sequentially passes through the third prism and the second prism, enters the first prism, is reflected plural times in the first prism, and is emitted from the first prism.

Abstract: An optical device and the prism module thereof are provided. The prism module includes a first prism, a second prism, a third prism and a fourth prism. The second prism is disposed beside the first prism. The second prism is attached to the third prism and the fourth prism. In operation, first visible light enters the first prism, is reflected plural times in the first prism, enters the second prism and then the fourth prism, is reflected at least one time in the fourth prism, returns to the second prism, is reflected at least one time in the second prism, enters the third prism and exits from the third prism. Also, second visible light enters the third prism, is reflected plural times in the third prism and exits from the third prism.

Abstract: An optical device and the prism module thereof are provided. The prism module includes a first prism, a second prism, a film and a light guide unit. The film is disposed between the first prism and the second prism. First visible light enters the first prism, passes through the film, enters the second prism, exits from the second prism, reaches the light guide unit, and is reflected to user's eyes by the light guide unit. Also, second visible light passes through the light guide and reaches user's eyes.

Abstract: An optical device includes an objective module, a prism module and an ocular module. The prism module includes a first prism, a second prism and a first coating. The prism module is disposed between the objective module and the ocular module. A first light beam emitted by an object sequentially passes through the objective module, the prism module and the ocular module. Central axes of the objective module and the ocular module are in parallel without overlapping.

Abstract: An optical system includes an objective lens module, an image inverting module, and an eyepiece module. The objective lens module includes a first lens group, a second lens group, a third lens group, a fourth lens group, and a fifth lens group. The optical system satisfies at least one of the following conditions: 0.45?LG4D/LG1D?0.8; 0.015 mm?1?1/fG3?0.045 mm?1; 0.045 mm?1?|1/fG4|?0.07 mm?1; 0.35?|fG4/fG3|?0.75; 0.15?fG1/f?1.6; wherein LG4D is an effective optical diameter of the fourth lens group, LG1D is an effective optical diameter of the first lens group, fG1 is an effective focal length of the first lens group, fG3 is an effective focal length of the third lens group, fG4 is an effective focal length of the fourth lens group, and f is an effective focal length of the objective lens module.

Abstract: A lens assembly for display includes a display, a lens assembly, and a prism assembly. The display emits a first light beam. The lens assembly includes a first, second, and third lenses. The prism assembly includes a first, second prisms, and an optical multilayer film, wherein the first prism includes a first, second, and third surfaces and the second prism includes a fourth, fifth, sixth, seventh, and eighth surfaces. The lens assembly for display satisfies at least one of following conditions: 0.60?Din/TTL?0.75; 0.28?Din/f123?0.35; 4.56 mm?Din?5.02 mm; wherein Din is an effective optical diameter of the light incident surface, TTL is an interval from the light incident surface to the light emitting surface along the optical axis, and f123 is an effective focal length of a combination of the first lens, the second lens, and the third lens.

Abstract: A lens assembly for display includes a display, a lens assembly, and a prism assembly. The display emits a first light beam. The prism assembly includes a first, second prisms, and an optical multilayer film, wherein the first prism includes a first, second, and third surfaces; the second prism includes a fourth, fifth, sixth, seventh, and eighth surfaces; and the optical multilayer film is disposed between the third and fifth surfaces. A second light beam enters the first prism through the first surface and exits by the second surface. The first light beam exits the lens assembly and enters the second prism through the eighth surface, and exits the first prism by the second surface. The lens assembly and the prism assembly satisfy: 0.80%?E1/E0?0.95%; wherein E0 is an energy of the first light beam emitted from the display and E1 is an energy of the first light beam passes through the lens assembly.

Abstract: An optical lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, all of which are arranged in order from an object side to an image side along an optical axis. The first lens is a meniscus lens with positive refractive power. The second lens is with positive refractive power. The third lens is with negative refractive power. The fourth lens is with positive refractive power and includes a convex surface facing the image side. The fifth lens is with negative refractive power and includes a concave surface facing the object side. The sixth lens is with positive refractive power and includes a convex surface facing the image side.

Abstract: A range finder includes a prism module and a prism adjusting mechanism. The prism module includes a fixing prism group and a movable prism group, wherein the fixing prism group is adjacent to the movable prism group. The prism adjusting mechanism includes a first adjusting group and a second adjusting group, wherein the first adjusting group includes a first adjusting member and a second adjusting member, and the second adjusting group includes a third adjusting member. The first adjusting member or the second adjusting member is rotated to axially move so that the movable prism group is rotated with respect to the fixing prism group about a first axis, the third adjusting member is rotated to axially move so that the movable prism group is rotated with respect to the fixing prism group about a second axis, and the first axis is perpendicular to the second axis.

Abstract: An optical device includes an objective module, a prism module and an ocular module. The prism module includes a first prism, a second prism and a first coating. The prism module is disposed between the objective module and the ocular module. A first light beam emitted by an object sequentially passes through the objective module, the prism module and the ocular module. Central axes of the objective module and the ocular module are in parallel without overlapping.

Abstract: An optical device includes an objective module, a prism module and an ocular module. The prism module includes a first prism, a second prism, a third prism and a first coating. The prism module is disposed between the objective module and the ocular module. A first light beam emitted by an object sequentially passes through the objective module, the prism module and the ocular module. Central axes of the objective module and the ocular module are in parallel without overlapping.

Abstract: A rotating shaft mechanism includes a first connecting portion, a second connecting portion, a central shaft rotatably connected to the first connecting portion and the second connecting portion, and an adjusting unit disposed on the central shaft. The adjusting unit includes an adjusting ring disposed around the central shaft, a first washer disposed around the central shaft and configured to generate a force to the first connecting portion or the second connecting portion. A position of the adjusting ring with respect to the central shaft is axially adjustable for adjusting the force so that the first connecting portion or the second connecting portion is rotatable or fixed relative to the central shaft.

Abstract: An optical lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, all of which are arranged in order from an object side to an image side along an optical axis. The first lens comprises a convex surface facing an image side. The second lens is with positive refractive power and comprises a convex surface facing an object side. The third lens is meniscus lens with refractive power. The fourth lens is meniscus lens with refractive power. The fifth lens is with negative refractive power and comprises a concave surface facing the object side. The sixth lens is meniscus lens with refractive power. The seventh lens is meniscus lens with positive refractive power.

Abstract: A lens assembly for display includes a display, a lens assembly, and a prism assembly. The display emits a first light beam. The prism assembly includes a first, second prisms, and an optical multilayer film, wherein the first prism includes a first, second, and third surfaces; the second prism includes a fourth, fifth, sixth, seventh, and eighth surfaces; and the optical multilayer film is disposed between the third and fifth surfaces. A second light beam enters the first prism through the first surface and exits by the second surface. The first light beam exits the lens assembly and enters the second prism through the eighth surface, and exits the first prism by the second surface. The lens assembly and the prism assembly satisfy: 0.80%?E1/E0?0.95%; wherein E0 is an energy of the first light beam emitted from the display and E1 is an energy of the first light beam passes through the lens assembly.

Abstract: A range finder includes a prism module and a prism adjusting mechanism. The prism module includes a fixing prism group and a movable prism group, wherein the fixing prism group is adjacent to the movable prism group. The prism adjusting mechanism includes a first adjusting group and a second adjusting group, wherein the first adjusting group includes a first adjusting member and a second adjusting member, and the second adjusting group includes a third adjusting member. The first adjusting member or the second adjusting member is rotated to axially move so that the movable prism group is rotated with respect to the fixing prism group about a first axis, the third adjusting member is rotated to axially move so that the movable prism group is rotated with respect to the fixing prism group about a second axis, and the first axis is perpendicular to the second axis.

Abstract: An optical lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, all of which are arranged in order from an object side to an image side along an optical axis. The first lens is a meniscus lens with positive refractive power. The second lens is with positive refractive power. The third lens is with negative refractive power. The fourth lens is with positive refractive power and includes a convex surface facing the image side. The fifth lens is with negative refractive power and includes a concave surface facing the object side. The sixth lens is with positive refractive power and includes a convex surface facing the image side.