A Cassegrain or quasi-Cassegrain structure objective lens is used in a polar MOKE metrology system. The quasi-Cassegrain reflective objective lens includes a primary concave mirror and a secondary mirror. The primary concave mirror has a wider diameter than the secondary mirror and defines an aperture through which the laser beam is configured to be transmitted toward the secondary mirror. The secondary mirror can be convex, concave, or have a flat surface.

The present disclosure relates to an imaging lens, a camera module and an electronic device including the same. The imaging lens according to an embodiment of the present disclosure includes a catadioptric lens on which light is incident from an object side, and through which light is reflected and emitted from the inside; and a lens group including a plurality of lenses for transmitting the light emitted from the catadioptric lens to an image surface, wherein the catadioptric lens includes: an incident surface on which light is incident from the object side; a second mirror surface which is formed concave toward the object side, and reflects the light incident on the incident surface to a first mirror surface in the object side; the first mirror surface which is formed, at a central portion of the incident surface, convex toward an image side, and reflects the light reflected from the second mirror surface toward the image side; and an exit surface through which the light reflected from the first mirror surface is emitted, wherein all of the lens group is disposed between the first mirror surface and the second mirror surface based on an optical axis. Accordingly, it is possible to increase the brightness of the lens, increase resolution, suppress an increase in thickness, and reduce tolerance due to mirror assembly.

The invention proposed the catadioptric system, which consists of two main components: the first component comprising the two reflective mirrors, in which surface distortion of mirror 1 is parabolic, surface distortion of mirror 2 is aspheric; the second component is a relay consisting of three lenses: lens 1, lens 2, and lens 3 arranged after the medial image plane correspondingly; the second component helps reduce aberration to ensure receiving good quality image at a plane of the sensor.

Provided is a camera lens of a catadioptric optical system consisting of two lens assemblies and one lens and having a small height, a narrow angle, and good optical properties. The camera lens includes: a first lens assembly including an object side surface having a first refractive surface and a second reflective surface in a peripheral region and a central region thereof, and an image side surface having a second refractive surface, a fifth refractive surface and a sixth refractive surface that are sequentially arranged from a peripheral region to a central region thereof; a second lens assembly including an object side surface having a third refractive surface and a fourth refractive surface that are sequentially arranged from a peripheral region to a central region, and an image side surface having a first reflective surface; and a third lens having a refractive power.

Provided are an imaging apparatus and a mobile imaging apparatus capable of reducing the size and weight of a structure relating to focus adjustment. The imaging apparatus 1 includes: a central optical system 12 that captures an image with pan focus; an annular optical system 14 that is disposed concentrically with the central optical system 12; and an image sensor 20 that simultaneously captures an image to be formed through the central optical system and an image to be formed through the annular optical system 14. In the imaging apparatus 1, the central optical system 12 and the image sensor 20 are moved integrally along the optical axis L so as to adjust a focal point of the annular optical system 14.

The system and method for combining two optical assemblies into the same volume, particularly when the field of view of the two assemblies are different, so that the overall volume and size, weight and power (SWaP) for the system is reduced. This also allows both subsystems (e.g., narrow field of view (NFOV) and wide field of view (WFOV) to use a single aperture and the same external protective window, reducing overall cost for a system of co-located dissimilar optical systems in a single aperture.

An imaging optical system comprises adjusters for adjusting a shape of each of at least two reflecting surfaces by applying a force to a rear surface of each of the reflecting surfaces. Points obtained by projecting force acting points of the adjusters in an optical axis direction defined with respect to the reflecting surface are defined as correction points, the acting points are set such that, when first and second rays in a light flux emitted from one point on the object plane are reflected by first and second reflecting surfaces, the first ray strikes the correction point of the first reflecting surface but does not strike the correction point of the second reflecting surface, and the second ray does not strike the correction point of the first reflecting surface but strikes the correction point of the second reflecting surface.

An imaging module includes a single-pupil head component with hyper-hemispherical entrance field with refractive entrance surface, concave exit face, a refractive central zone and reflective peripheral zone. The imaging module also includes a secondary mirror, an aberrations corrector having an aspherical lens, a focusing objective, and an aperture diaphragm between the aberrations corrector and the objective. The head component is quasi-afocal in the vicinity of the field of 90° angular radius, its entrance surface has a ½ vertex angle of smaller than 30°, the secondary mirror is aspherical with variable local focal length with a maximum local power for a zone used by a field of 90° angular radius and minimum smaller by at least a factor of 2 for a zone used by a field of angular radius smaller than 20°.

A variable magnification optical system consists of, in order from an object side, a first optical system remaining stationary during changing magnification and a second optical system including a plurality of lens groups moving during changing magnification. The first optical system includes a first mirror and a second mirror having reflective surfaces arranged to face each other. The first mirror is an optical element having a power at a position closest to the object side on an optical path and has a reflective surface concave toward the object side. The second mirror has a reflective surface convex toward the image side. An intermediate image is formed between the second mirror and the second optical system.

In one aspect, an apparatus includes a first aspheric refractive surface defined by a first polynomial and positioned to receive input light, and a first aspheric mirror surface comprising a first reflective coating, the first mirror surface defined by a second polynomial and positioned to receive light from the first aspheric refractive surface. The apparatus includes a second aspheric mirror surface comprising a second reflective coating, the second aspheric mirror surface defined by a third polynomial and positioned to receive light from the first aspheric mirror surface, and a second aspheric refractive surface defined by a fourth polynomial and positioned to receive light from the second aspheric mirror surface, wherein the first aspheric refractive surface, the first aspheric mirror surface, the second aspheric mirror surface, and the second aspheric refractive surface are arranged to have a fixed alignment with respect to each other as part of a monolithic structure.