3 results about "Secondary mirror" patented technology

The invention relates to a free-form surface off-axis three-mirror imaging system. The free-form surface off-axis three-mirror imaging system comprises a primary mirror, a secondary mirror, a third mirror and a detector. After being sequentially reflected by the primary mirror, the secondary mirror and the third mirror, light is received by the detector and imaged. An angle of field of view of thefree-form surface off-axis three-mirror imaging system is greater than or equal to 60 degrees * 1 degree, and the F number is smaller than or equal to 2.5.

The invention discloses a calibration optical system based on a geosynchronous orbit differential absorption spectrometer. The calibration optical system is composed of an oscillating mirror system, afront optical system, a solar diffuse reflection plate assembly and a solar light blocking door assembly. The oscillating mirror system is composed of a pointing mirror, a sweeping shaft system, a motor harmonic group and an oscillating mirror U-shaped bracket. The front optical system consists of a primary mirror, a secondary mirror, a third mirror, a plane mirror and a slit. The solar diffuse reflection plate assembly consists of a Teflon diffuse reflection plate and corresponding structural components. The solar light blocking door assembly includes a solar baffle and a motor assembly. Thecalibration optical system introduces a bidirectional reflection distribution function of external solar illuminance with known spectral irradiance at suitable on-board calibration time, thereby accurately measuring the diffuse reflection plate and establishing an approximate lambertian surface source with known spectral radiance to provide known radiation input for a remote sensor. The system has high measurement accuracy, compact volume, light weight and high reliability.

The invention discloses a compact large-relative-aperture long-focus high-definition optical system for target detection, and belongs to the technical field of optics. The compact large-relative-aperture long-focus high-definition optical system comprises a front lens correction group, a Cassegrain system, a rear lens correction group and an SCMOS sensor. A light beam sequentially passes through the front lens correction group, the Cassegrain system and the rear lens correction group and is finally imaged on the target surface of the SCMOS sensor. The front lens correction group corrects spherical aberration related to aperture. The rear lens correction group balances the aberration and expands the field of view of the optical system. According to the invention, the working wave band is 486.13 nm-656.27 nm, and the method can be used for an airborne rapid target search system. The characteristics of the opening of a Cassegrain type primary mirror and the blocking of a secondary mirror are fully utilized, the lens correction groups are respectively arranged on the two outer sides of the Cassegrain type system, the whole system is compact in structure, and the size of the optical system is greatly reduced. Meanwhile, the imaging quality of the optical system is good, and diffraction spots and a transfer function are close to diffraction limits.