Temperature control of star sensor baffle using 3D printing and PCM thermal energy storage technology

The invention relates to the field of the optical lens, and discloses a pick-up optical lens. The pick-up optical lens comprises a first lens with positive refraction power, a second lens with negative refraction power, a third lens with positive refraction power, a fourth lens with negative refraction power and a fifth lens from an object side to an image side; the curvature radius of the first lens image side is R2, the curvature radius of the first lens object side is R1, the focal length of the third lens is f3, the entire focal length of the pick-up optical lens is f, the on-axis range tothe object side of the third lens from the image side of the second lens is d4, the on-axis thickness of the second lens is d3, the refractive index of the fourth lens is n4, and the following relation formulas are satisfied: R1/R1 is not less than -20.00 and not more than -2.00, f3/f is not less than 0.50 and not less than 3.50, d4/d3 is not less than 1.50 and not more than 5.00, and n4 is not less than 1.69 and not more than 2.10. The pick-up optical lens provided by the invention can satisfy the design requirements of large aperture and long focal length when the good optical performance is provided.

Pick-up optical lens

A system for remotely detecting gas concentration is provided. The system includes a plurality of light sources. At least a first one of the light sources generates light having a first wavelength and a first polarization, and at least a second one of the light sources generates light having a second, different wavelength and a second polarization that is orthogonal to the first polarization. The light from the light sources is placed on a common transmission path, and is directed to a target area by a steering mirror. Light reflected from the target area is received and directed to a detector. The detector provides information regarding the time of arrival and amplitude of the received light, allowing range and gas concentration information to be obtained. In some embodiments the detector is an imaging detector, allowing three-dimensional range information to be obtained from the target area from a single light pulse.

Differential absorption lidar

The invention discloses a correction method for local distortion The method comprises the following steps: acquiring an image shot by a large-viewing-angle lens of a mobile terminal; acquiring an image region to be corrected in the image, wherein the distortion degree parameter of the image region to be corrected is greater than or equal to a preset distortion degree parameter; acquiring a central pixel grid of the image according to a preset size; partitioning the image region to be corrected into N pixel grids of which the sizes are the same as the size of the central pixel grid, wherein N is an integer greater than or equal to 2; and correcting the N pixel grids by taking the central pixel grid as a distortion correction reference to obtain a corrected image The embodiment of the invention also provides the mobile terminal Through adoption of the embodiment of the invention, the distortion of the image shot by the large-viewing-angle lens can be corrected at a certain degree

Correction method for local distortion and mobile terminal

The invention provides a high-accuracy automatic image plane adjustment device, aiming at solving the technical problems such as low operation efficiency, low accuracy and the like, of the prior art. The device comprises a lens bracket, a substrate, a moving platform and a feedback control system, wherein the lens bracket is used for fixing an optics lens; the substrate is used for fixing a CCD (Charge-coupled Device) imaging device; the moving platform is used for dragging the lens bracket to make axial linear displacement relative to the substrate; the moving platform comprises a base, a linear motor, guide rails and a slide block which is installed on the guide rails; the guide rails are fixedly arranged on the base; the lens bracket is fixedly connected with the slide block; the substrate and the base are fixedly oppositely arranged; a fixed part of the linear motor is fixedly arranged on the base; a moving part of the linear motor is fixedly connected with the slide block along the direction of the guide rails. The high-accuracy automatic image plane adjustment device is simple in structure, easy to operate, simple to control and high positioning accuracy, and can be widely applied in the engineering practice of image plane adjustment on the optics lens.

High-accuracy automatic image plane adjustment device and adjustment method thereof

The invention discloses a correction method for fisheye image distortion. The method includes the following steps that firstly, a fisheye image of a standardized test grid plate and an actual image of the fisheye image are obtained; secondly, distortion measurement is conducted on the obtained fisheye image, and distortion coefficients are calibrated according to a polar coordinate model; thirdly, correction is conducted according to a correction model, and in order to guarantee correction precision, sectioned correction is conducted according to a central view field, a middle view field and an edge view field during correction; fourthly, pixels obtained after spatial alternation are endowed with corresponding gray values through a bilinear interpolation method so that the gray value of an original position can be restored. Reverse operation is simple, measurement precision is high, and the correction method is easily achieved in hardware systems such as an EPGA and a DSP. The correction method has high practical value.

Correction method for fisheye image distortion

This paper designs a compact apochromatic lens with long focal length, which operates over very-broad spectrum from 400nm to 900nm for high resolution image application. The focal length is 290mm, and F-number is 4.5.In order to match CCD sensor, lens resolution must be higher than 100lp/mm. It is a significant challenge to correct secondary spectrum over very-broad spectrum for this application. The paper firstly pays much attention on dispersion characteristic of optical materials over this very-broad spectrum, and dispersion characteristic of glasses is analyzed. After properly glasses combinations and optimal lens structure selected, this compact apochromatic lens is designed. The lens described in this paper comprises fewer lenses, most of them are ordinary optical materials, and only one special flint type TF3 with anomalous dispersion properties is used for secondary spectrum correction. Finally, the paper shows MTF and aberration curve for performance evaluation. It can be seen that MTF of the designed lens nearly reach diffraction limit at Nyquist frequency 100lp/mm, and residual secondary spectrum is greatly reduced to less than 0.03mm (in the lines 550nm and 787.5nm). The overall length of this compact apochromatic lens is just 0.76 times its focal length, and because of fewer lenses and ordinary optical materials widely used, production cost is also greatly reduced.

Design of compact apochromatic lens with very-broad spectrum and high resolution

The invention provides a combined adjusting and jointing method and a combined adjusting and jointing mechanism for a visible light imaging system and an imaging focal plane. The problem that the accuracy of perpendicularity between an optical axis of an optical imaging system and the imaging focal plane, the accuracy of an overlap ratio between the optical axis of the optical imaging system and the central normal of the target surface of the imaging focal plane and the accuracy of an overlap ratio between the image plane of the optical imaging system and the imaging focal plane in the conventional image plane jointing process cannot be ensured is mainly solved. By once clamping of a high-accuracy double-shaft lathe, a set regulation aim is fulfilled, the set regulation accuracy is achieved, and meanwhile, the jointing reference surface of a focal plane component and the end face of an optical lens mounting flange are turned, so that the parallelism between two planes is ensured, and an assembly error, which is caused by a previous assembly link, of the focal plane component and an optical lens is completely eliminated.

Combined adjusting and jointing method and mechanism for high-accuracy visible light imaging system

The utility model provides a large-view-field high-resolution optical system of a three-linear-array stereo aerial survey camera. The optical system comprises a first negative lens, a first correcting lens, a first positive lens, a second negative lens, a doublet lens, a third positive lens, a diaphragm, a fourth positive lens, a triplet lens, a third negative lens, a fifth positive lens and a sixth positive lens which are successively arranged along the same optical axis, wherein the first correcting lens is of a meniscus type, and the bending direction of the first correcting lens is deviated from the diaphragm; the gluing surface of the doublet lens is deviated from the diaphragm; and the triplet lens employs a structure which successively includes a negative lens, a positive lens and a negative lens. The optical system of the utility model is characterized by large view field, high resolution, ultralow distortion, quasi image telecentricity, and the like.

Zhang Kaisheng

Papers

Correction method for fisheye image distortion

High-accuracy automatic image plane adjustment device and adjustment method thereof

Design of compact apochromatic lens with very-broad spectrum and high resolution

Combined adjusting and jointing method and mechanism for high-accuracy visible light imaging system

Large-view-field high-resolution optical system of three-linear-array stereo aerial survey camera