Abstract: A light path folding element includes a first surface, a second surface, a first reflecting surface and a second reflecting surface. A light travels from the first surface into the light path folding element. The second surface is disposed relative to the first surface along a first direction and is parallel to the first surface, and the first direction is perpendicular to the first surface. The first reflecting surface connects the first surface and the second surface, an acute angle is formed between the first reflecting surface and the first surface, and the light forms an internal reflection via the first reflecting surface. The light forms another internal reflection via the second reflecting surface. The light path folding element further includes a light blocking structure, which extends from at least one of the first surface and the second surface into the light path folding element.

Abstract: An imaging lens includes a light blocking sheet that includes an inner ring surface, a plurality of tapered light blocking structures, and a nanostructure layer. The inner ring surface surrounds an optical axis and defines a light passage opening. The tapered light blocking structures are disposed on the inner ring surface, and each tapered light blocking structure protrudes from the inner ring surface and tapers off towards the optical axis. The tapered light blocking structures are periodically arranged to surround the optical axis. The contour of each tapered light blocking structure has a curved part in a view along the optical axis. The curved part forms a curved surface on the inner ring surface. The nanostructure layer is disposed on the curved surface and has a plurality of ridge-like protrusions that extend non-directionally, and the average structure height of the nanostructure layer ranges from 98 nanometers to 350 nanometers.

Abstract: A light blocking sheet includes a first surface, a second surface, an inner annular surface and an outer annular surface. The second surface is corresponding to the first surface. The inner annular surface connects the first surface and the second surface, and forms an inner opening. The outer annular surface connects an edge of the first surface and an edge of the second surface, and includes at least three notches disposed on the outer annular surface and at least three arc surfaces located on the outer annular surface, wherein the at least three notches and the at least three arc surfaces are alternately arranged on the outer annular surface, and the at least three arc surfaces are coaxial and have different arc lengths.

Abstract: A light blocking sheet includes a first surface, a second surface, an inner annular surface and an outer annular surface. The second surface is corresponding to the first surface. The inner annular surface connects the first surface and the second surface, and forms an inner opening. The outer annular surface connects an edge of the first surface and an edge of the second surface, and includes at least three notches disposed on the outer annular surface and at least three arc surfaces located on the outer annular surface, wherein the at least three notches and the at least three arc surfaces are alternately arranged on the outer annular surface, and the at least three arc surfaces are coaxial and have different arc lengths.

Abstract: A light blocking sheet includes a first surface, a second surface, an inner annular surface and an outer annular surface. The second surface is corresponding to the first surface. The inner annular surface connects the first surface and the second surface, and forms an inner opening. The outer annular surface connects an edge of the first surface and an edge of the second surface, and includes at least three notches disposed on the outer annular surface and at least three arc surfaces located on the outer annular surface, wherein the at least three notches and the at least three arc surfaces are alternately arranged on the outer annular surface, and the at least three arc surfaces are coaxial and have different arc lengths.

Abstract: An annular optical spacer includes a first side portion, a second side portion, an outer annular portion and an inner annular portion. The second side portion is disposed opposite to the first side portion. The outer annular portion connects the first side portion and the second side portion. The inner annular portion connects the first side portion and the second side portion, wherein the inner annular portion is closer to a central axis of the annular optical spacer than the outer annular portion. The inner annular portion includes a plurality of annular grooves, wherein the annular grooves are disposed coaxially to the central axis, and each of the annular grooves includes a plurality of stepped surfaces.

Abstract: An annular optical spacer includes a first side portion, a second side portion, an outer annular portion and an inner annular portion. The second side portion is disposed opposite to the first side portion. The outer annular portion connects the first side portion and the second side portion. The inner annular portion connects the first side portion and the second side portion, wherein the inner annular portion is closer to a central axis of the annular optical spacer than the outer annular portion. The inner annular portion includes a plurality of annular grooves, wherein the annular grooves are disposed coaxially to the central axis, and each of the annular grooves includes a plurality of stepped surfaces.

Abstract: An annular optical spacer includes a first side portion, a second side portion, an outer annular portion and an inner annular portion. The second side portion is disposed opposite to the first side portion. The outer annular portion connects the first side portion and the second side portion. The inner annular portion connects the first side portion and the second side portion, wherein the inner annular portion is closer to a central axis of the annular optical spacer than the outer annular portion. The inner annular portion includes a plurality of annular grooves, wherein the annular grooves are disposed coaxially to the central axis, and each of the annular grooves includes a plurality of stepped surfaces.

Abstract: A light blocking sheet includes a first surface, a second surface, an inner annular surface and an outer annular surface. The second surface is corresponding to the first surface. The inner annular surface connects the first surface and the second surface, and forms an inner opening. The outer annular surface connects an edge of the first surface and an edge of the second surface, and includes at least three notches disposed on the outer annular surface and at least three arc surfaces located on the outer annular surface, wherein the at least three notches and the at least three arc surfaces are alternately arranged on the outer annular surface, and the at least three arc surfaces are coaxial and have different arc lengths.

Abstract: An annular optical spacer includes a first side portion, a second side portion, an outer annular portion and an inner annular portion. The second side portion is disposed opposite to the first side portion. The outer annular portion connects the first side portion and the second side portion. The inner annular portion connects the first side portion and the second side portion, wherein the inner annular portion is closer to a central axis of the annular optical spacer than the outer annular portion. The inner annular portion includes a plurality of annular grooves, wherein the annular grooves are disposed coaxially to the central axis, and each of the annular grooves includes a plurality of stepped surfaces.