An optical lens assembly includes four lens elements which are, in order from an object side to an image side along an imaging optical path: a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element has positive refractive power. The second lens element has an image-side surface being concave in a paraxial region thereof. The third lens element has an object-side surface being concave in a paraxial region thereof. The fourth lens element with negative refractive power has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, and at least one of the object-side surface and the image-side surface of the fourth lens element has at least one inflection point in an off-axis region thereof.

A process is provided for imaging a surface of a specimen with an imaging system that employs a BD objective having a darkfield channel and a bright field channel, the BD objective having a circumference. The specimen is obliquely illuminated through the darkfield channel with a first arced illuminating light that obliquely illuminates the specimen through a first arc of the circumference. The first arced illuminating light reflecting off of the surface of the specimen is recorded as a first image of the specimen from the first arced illuminating light reflecting off the surface of the specimen, and a processor generates a 3D topography of the specimen by processing the first image through a topographical imaging technique. Imaging apparatus is also provided as are further process steps for other embodiments.

An optical member driving mechanism is provided. The optical member driving mechanism includes a first movable portion, a fixed portion, a first driving assembly, and a plurality of second guiding members. The first movable portion is configured to connect an optical member. The optical member is used for adjusting a direction of a light from an incident direction to an outgoing direction. The first movable portion can move relative to the fixed portion. The first driving assembly is configured to drive the first movable portion to move relative to the fixed portion. The second guiding members include a first ball, a second ball, and a third ball. The first ball, the second ball, and the third ball are disposed in a plane that is perpendicular to the incident direction.

A camera module includes a lens module having a plurality of lenses and disposed to be movable along an optical axis, an image sensor module receiving light passing through the lens module, and a light shielding member disposed in a space between the lens module and the image sensor module, wherein the light shielding member includes a frame having a window through which the light passes, and a damping member disposed on one surface of the frame facing the lens module to limit movement of the lens module.

A telecentric optical apparatus that is capable of suppressing an increase in the number of components as well as achieving high precision optical axis alignment, is provided. The telecentric optical apparatus of the present invention is characterized in that it is provided with: a first telecentric lens surface that is provided on an object side; a second telecentric lens surface that is provided on an image side and that shares a focus position with the first telecentric lens surface; and an optical path trimming part that is provided, between the first telecentric lens surface and the second telecentric lens surface, in an outside region, which is located on a side further out than a light passing region having a center thereof located at the focus position, and that changes an optical path such that a light beam incident on the outside region is prevented from contributing to image formation.

A pattern projector is disclosed. The pattern projector comprises a light source, a projection lens, a mask and configured to enable the at least one projection lens to illuminate a target while projecting the pre-defined pattern thereat, and at least one holder, and wherein the pattern projector is characterized in that the at least one light source is a wide area light source, and wherein the area of the at least one mask or the at least one mask active area, is smaller than the area of the at least one light source, enabling to refrain from applying condenser optics or focusing optics between the at least one light source and the at least one mask.

The present invention relates to the technical field of optical lens and discloses a camera optical lens satisfying the following conditions: −1.00≤(f1+f2)/f≤−0.10, 12.00≤d3/d4≤20.00, 5.00≤R5/d5≤11.00, 8.00≤d7/d8≤14.00; where f1 and f2 respectively denote a focal length of a first and second lenses, d3, d5 and d7 respectively denote an on-axis thickness of the second, third and fourth lenses, d4 denotes an on-axis distance from an image-side surface of the second lens to an object-side surface of the third lens, d8 denotes an on-axis distance from an image-side surface of the fourth lens to an object-side surface of the fifth lens, and R5 denotes a curvature radius of the object-side surface of the third lens. The camera optical lens has good optical functions and satisfies a design requirement of wide angle and ultra-thinness.

The present invention provides a camera optical lens including, from an object side to an image side, a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens, a fourth lens having a positive refractive power, a fifth lens having a negative refractive power, a sixth lens having a negative refractive power, a seventh lens having a positive refractive power and a eighth lens having a negative refractive power. The camera optical lens satisfies the following conditions: 0.65≤f1/f≤0.85, 2.00≤f4/f≤5.00, and −5.50≤f5/f≤−2.50; where f, f1, f4 and f5 respectively denote a focal length of the camera optical lens, the first lens, the fourth lens and the fifth lens. The camera optical lens in the present disclosure has characteristics of large aperture, wide angle and ultra-thinness while having good optical functions.

An optical system for collecting distance information within a field is provided. The optical system may include lenses for collecting photons from a field and may include lenses for distributing photons to a field. The optical system may include lens tubes that collimate collected photons, optical filters that reject normally incident light outside of the operating wavelength, and pixels that detect incident photons. The optical system may further include illumination sources that output photons at an operating wavelength.

A lens assembly includes a front lens group and a rear lens group. The front lens group includes a first lens having positive refractive power and a second lens having negative refractive power. The rear lens group includes a third lens having positive refractive power and a fourth lens having negative refractive power, wherein the third lens includes a convex surface facing an object side and another convex surface facing an image side and the fourth lens includes a concave surface facing the image side. The first lens, the second lens, the third lens, and the fourth lens are arranged in order from the object side to the image side along an optical axis. The lens assembly satisfies: 13.5 mm<f+f.sub.1<20 mm; wherein f is an effective focal length of the lens assembly and f.sub.1 is an effective focal length of the first lens.