The finder includes, in order from an object side to an eye point side, a negative objective lens group, and a positive eyepiece lens group. The eyepiece lens group consists of, in order from the object side to the eye point side, a negative first lens, a positive second lens, and a negative third lens. During diopter adjustment, only the second lens moves. The finder satisfies a conditional expression determined in advance.

A vehicle projection lens includes a plastic aspheric first lens, an aperture stop, a cemented lens consisting of a glass second lens and a glass third lens, and a glass fourth lens arranged in order from a magnified side to a minified side. An F-number of the vehicle projection lens is smaller than or equal to 0.8, and the vehicle projection lens consists essentially of four lenses respectively with positive, positive, negative and positive refractive powers.

A fixed focal length imaging optical system includes a first lens group having positive power, a second lens group having positive power, and a third lens group having negative power in order from an object side toward an image side. Upon focusing, the second lens group moves along an optical axis, and the first lens group and the third lens group do not move. The present disclosure provides the fixed focal length imaging optical system capable of favorably correcting various aberrations such as spherical aberration, astigmatism, and distortion, and an imaging device and a camera system each of which includes the fixed focal length imaging optical system.

A fixed focal length imaging optical system includes a first lens group having positive power, a second lens group having positive power, and a third lens group having negative power in order from an object side toward an image side. Upon focusing, the second lens group moves along an optical axis, and the first lens group and the third lens group do not move. The present disclosure provides the fixed focal length imaging optical system capable of favorably correcting various aberrations such as spherical aberration, astigmatism, and distortion, and an imaging device and a camera system each of which includes the fixed focal length imaging optical system.

A lens assembly is configured to be disposed under a cover glass, in a gap region and outside a display region, including a plurality of lenses, a reflector and an image sensor. The lenses, the reflector and the image sensor are sequentially arranged from an object side to an image side along an optical axis. One of the lenses is adjacent to the object side, has a minimum diameter of clear aperture, and has an outer circumferential portion which is non-circular. The lens assembly satisfies at least one of following conditions: BFL≥VL and BFL≥0.6×DL where BFL is a back focal length of the lens assembly, VL is a minimum side length of the image sensor, and DL is a diagonal length of the image sensor. A lens device includes a cover glass, a case, a display panel and the lens assembly.

A lens assembly is configured to be disposed under a cover glass, in a gap region and outside a display region, including a plurality of lenses, a reflector and an image sensor. The lenses, the reflector and the image sensor are sequentially arranged from an object side to an image side along an optical axis. One of the lenses is adjacent to the object side, has a minimum diameter of clear aperture, and has an outer circumferential portion which is non-circular. The lens assembly satisfies at least one of following conditions: BFL≥VL and BFL≥0.6×DL where BFL is a back focal length of the lens assembly, VL is a minimum side length of the image sensor, and DL is a diagonal length of the image sensor. A lens device includes a cover glass, a case, a display panel and the lens assembly.

A lens module including a lens barrel and a plurality of lenses having refractive power is provided. The lenses are arranged in the lens barrel from an object side to an image side. The lens barrel has an inner-wall surface and an outer-wall surface opposite to each other, and has an air outlet communicating with outside. The air outlet is located between the inner-wall surface and the outer-wall surface. A first lens of these lenses is a lens closest to the object side. The first lens has an object-side optical surface facing the object side. At least over 95% of the surface area of the object-side optical surface of the first lens is exposed to outside, and a material of the first lens is glass. Furthermore, another lens module is also provided.

An internal-reflective telecentric lens system includes a first lens assembly, a reflector, and a second lens assembly. The first lens assembly includes a first lens. The second lens assembly includes a second lens, a third lens, and a fourth lens, that are disposed in sequence along a light path. The first lens assembly is configured to receive and output one or more light beams towards the reflector. The reflector is configured to reflect the light beams towards the second lens assembly. The second lens assembly is configured to receive and converge the light beams reflected by the reflector at a diaphragm between the second lens and the third lens, and transmit the light beams past the diaphragm through the third and the fourth lenses for imaging.

The imaging lens consists of, in order from the object side, a first positive lens group, a stop, a second positive lens group, and a third negative lens group. The first lens group includes a negative lens which has a concave surface on the image side, and two positive lenses which are disposed to be closer to the image side than the negative lens and which have respective convex surfaces on the object side, convex surfaces on the object side. The second lens group includes an aspheric lens, and two sets of cemented lenses disposed to be closer to the image side than the aspheric lens. The third lens group consists of one lens component.

The imaging lens consists of, in order from the object side, a first positive lens group, a stop, a second positive lens group, and a third negative lens group. The first lens group includes a negative lens which has a concave surface on the image side, and two positive lenses which are disposed to be closer to the image side than the negative lens and which have respective convex surfaces on the object side, convex surfaces on the object side. The second lens group includes an aspheric lens, and two sets of cemented lenses disposed to be closer to the image side than the aspheric lens. The third lens group consists of one lens component.