A five-piece infrared single focus lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element, a third lens element with a positive refractive power, a fourth lens element, a fifth lens element, wherein a focal length of the first lens element is f1, a focal length of the third lens element is f3, a central thickness of the first lens element along an optical axis is CT1, a central thickness of the third lens element along the optical axis is CT3, a radius of curvature of an object-side surface of the first lens element is R1, a radius of curvature of an object-side surface of the third lens element is R5, satisfying the relation: −1.60<(f1×CT1×R1)/(f3×CT3×R5)<2.43. Such a system has a wide field of view, high resolution, short length and less distortion.

A five-piece infrared single focus lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element, a third lens element with a positive refractive power, a fourth lens element, a fifth lens element, wherein a focal length of the first lens element is f1, a focal length of the third lens element is f3, a central thickness of the first lens element along an optical axis is CT1, a central thickness of the third lens element along the optical axis is CT3, a radius of curvature of an object-side surface of the first lens element is R1, a radius of curvature of an object-side surface of the third lens element is R5, satisfying the relation: −1.60<(f1×CT1×R1)/(f3×CT3×R5)<2.43. Such a system has a wide field of view, high resolution, short length and less distortion.

An electronic device includes at least one optical lens assembly. The optical lens assembly includes four lens elements, and the four lens elements are, in order from an outside to an inside, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element has an outside surface being convex in a paraxial region thereof. The second lens element has an inside surface being convex in a paraxial region thereof. The fourth lens element has an inside surface being concave in a paraxial region thereof, wherein at least one of an outside surface and the inside surface of the fourth lens element includes at least one critical point in an off-axis region thereof.

This disclosure relates to the minimally invasive medical technical field, and specifically, to a device of anti-fogging endoscope system including a beam of a near-infrared light for anti-fogging, which is coupled into an endoscope imaging optical channel in combination coaxially and is transmitted to the front optical window sheet, the visible light passes through the front optical window sheet, and the near-infrared light is absorbed by the absorption characteristics of the front optical window sheet to raise the temperature of the front optical window sheet. The device is also provided with a cut filter for eliminating the impact on image quality caused by the near-infrared stray light, so that the illumination light source of the prior-art endoscope is not necessary to be changed. It is suitable to integrate the coaxial coupling module with a camera handle or adapter and is more convenient to operate the device.

This disclosure relates to the minimally invasive medical technical field, and specifically, to a device of anti-fogging endoscope system including a beam of a near-infrared light for anti-fogging, which is coupled into an endoscope imaging optical channel in combination coaxially and is transmitted to the front optical window sheet, the visible light passes through the front optical window sheet, and the near-infrared light is absorbed by the absorption characteristics of the front optical window sheet to raise the temperature of the front optical window sheet. The device is also provided with a cut filter for eliminating the impact on image quality caused by the near-infrared stray light, so that the illumination light source of the prior-art endoscope is not necessary to be changed. It is suitable to integrate the coaxial coupling module with a camera handle or adapter and is more convenient to operate the device.

An apparatus having an asymmetric adjustable lens with a deformable optical element. The apparatus may also include one or more actuators coupled to a deformable element of the asymmetric adjustable lens in a direct-drive configuration such that (1) mechanical action of the one or more actuators applies force to the deformable optical element and (2) the force applied by the mechanical action of the one or more actuators changes an optical property of the asymmetric adjustable lens by deforming the deformable optical element. Various other devices, systems, and methods are also disclosed.

An optical imaging lens system includes four lens elements arranged along an optical axis. The optical imaging lens system satisfies the relations 2.13°≤HFOV/Fno≤8.75°; 3.85≤TTL/T1≤7.00; and 0.8≤AC34/T3, where a half field of view of the optical imaging lens system is defined as HFOV, an F number of the optical imaging lens system is defined as Fno, a distance measured from the object-side surface of the first lens element to an image plane along the optical axis is defined as TTL, a thickness of the first lens element along the optical axis is defined as T1, an air gap between the third and fourth lens elements along the optical axis is defined as AC34, a thickness of the third lens element along the optical axis is defined as T3.

An optical imaging lens system includes four lens elements arranged along an optical axis. The optical imaging lens system satisfies the relations 2.13°≤HFOV/Fno≤8.75°; 3.85≤TTL/T1≤7.00; and 0.8≤AC34/T3, where a half field of view of the optical imaging lens system is defined as HFOV, an F number of the optical imaging lens system is defined as Fno, a distance measured from the object-side surface of the first lens element to an image plane along the optical axis is defined as TTL, a thickness of the first lens element along the optical axis is defined as T1, an air gap between the third and fourth lens elements along the optical axis is defined as AC34, a thickness of the third lens element along the optical axis is defined as T3.

The invention relates to a hybrid objective with fixed focal length, which has a total of four lenses. Two lenses consist of glass and two lenses consist of plastic. The objective is suitable for use in a LID AR measurement system.

A multilayer mirror for reflecting Extreme Ultraviolet (EUV) radiation and a method for producing the same are disclosed. In an embodiment a multilayer mirror includes a layer sequence having a plurality of alternating first layers and second layers, the first layers including lanthanum or a lanthanum compound and the second layers including boron, wherein the second layers are doped with carbon, and wherein a molar fraction of carbon in the second layers is 10% or less.