Abstract: A fixed focal imaging lens includes two lens sets and an aperture stop. One of the two lens sets is disposed between a magnified side and the aperture stop. The other one of the two lens sets is disposed between the aperture stop and a minified side. The lens set disposed between the magnified side and the aperture stop includes an aspheric lens and a compound lens, wherein the aspheric lens is a lens closest to the magnified side in the lens set, and the compound lens includes a plurality of lenses combined together. The lens set disposed between the aperture stop and the minified side includes a compound lens and an aspheric lens, wherein the compound lens includes a plurality of lenses combined together, and the aspheric lens is a lens closest to the minified side in the lens set.

Abstract: A lens including a filter, an aperture stop, and a lens set sequentially arranged along a first direction is provided. The filter includes a central region and a peripheral region. The central region has a first light transmission band for a wavelength range of a visible light and a second light transmission band for a wavelength range of an infrared light. The peripheral region surrounds the central region. The peripheral region has a third light transmission band for the wavelength range of the infrared light and is substantially opaque to the visible light, and an area of one portion of the central region surrounded by the peripheral region is tapered toward the first direction.

Abstract: A fixed focal imaging lens includes two lens sets and an aperture stop. One of the two lens sets is disposed between a magnified side and the aperture stop. The other one of the two lens sets is disposed between the aperture stop and a minified side. The lens set disposed between the magnified side and the aperture stop includes an aspheric lens and a compound lens, wherein the aspheric lens is a lens closest to the magnified side in the lens set, and the compound lens includes a plurality of lenses combined together. The lens set disposed between the aperture stop and the minified side includes a compound lens and an aspheric lens, wherein the compound lens includes a plurality of lenses combined together, and the aspheric lens is a lens closest to the minified side in the lens set.

Abstract: A lens including a filter, an aperture stop, and a lens set sequentially arranged along a first direction is provided. The filter includes a central region and a peripheral region. The central region has a first light transmission band for a wavelength range of a visible light and a second light transmission band for a wavelength range of an infrared light. The peripheral region surrounds the central region. The peripheral region has a third light transmission band for the wavelength range of the infrared light and is substantially opaque to the visible light, and an area of one portion of the central region surrounded by the peripheral region is tapered toward the first direction.