Transmissive Ultra Long Focal Length HD Zoom Lens for 3ccd Video Camera

Abstract

The invention relates to a transmission type ultra-long-focal-length high-definition zoom lens applicable to 3CCD cameras, which includes a frame and an optical system in the frame. The optical system includes a front fixed group A, a zooming group B, a compensation group C, a variable diaphragm D and a rear fixed group E which are arranged in sequence along the incident direction of light. The front fixed group A includes a biconvex lens A1, a plane-convex lens A2, and a first cemented group composed of a negative meniscus lens A3 and a positive meniscus lens A4. The zooming group B includes a second cemented group composed of a biconcave lens B1, a plane-convex lens B2 and a plane-concave lens B3, and a negative meniscus lens B4. The compensation group C includes a biconvex lens C1, a third cemented group composed of a biconvex lens C2 and a negative meniscus lens C3, and a positive meniscus lens C4. The rear fixed group E includes a fourth cemented group composed of a biconcave lens E1 and a biconvex lens E2, a biconvex lens E3, a negative meniscus lens E4, and a positive meniscus lens E5. The resolution of the lens is improved significantly and reaches two million pixels, so the lens can adapt to a high-definition 3CCD camera.

Description

Technical field: [0001] The invention relates to a transmission type ultra-long focal length high-definition zoom lens suitable for a 3CCD camera. Background technique: [0002] For telephoto surveillance lenses, the reflective structure is generally used, which can achieve the overall length of the system and the purpose of compact structure. However, the reflective system has defects such as small field of view, central occlusion, reduced diffraction limit, and difficulty in eliminating stray light. In the case of the transmissive structure, there are problems such as difficulty in shortening the total length of the system, difficulty in selecting materials for large-sized glass, and difficulty in correcting aberrations, especially secondary spectral aberrations. The equivalent glass is thick and needs to be matched with the lens, and its impact should be considered in the lens design stage; as the pixel size of the image sensor continues to decrease, its characteristic fr...

AI Technical Summary

Problems solved by technology

[0002] For telephoto surveillance lenses, reflective structures are generally used, which can achieve the purpose of overall system length and compact structure, but reflective systems have defects such as small field of view, central occlusion, reduced diffraction limit, and difficulty in eliminating stray light; when using In the case of a transmissive structure, there are problems such as the difficulty in shortening the total length of the system, the difficulty in selecting materials for large-size glass, and the difficulty in correcting aberrations, especially secondary spectral aberrations. The equivalent glass is thicker and needs to be matched with the lens, and its influence should be considered in the lens design stage; as the pixel size of the image sensor continues to decrease, its characteristic frequency increases rapidly, and the photoelectric video surveillance also needs to increase the resolution level and improve the product quality. Competitiveness

Images