Prime lens

Abstract

The embodiment of the invention discloses a prime lens. The prime lens comprises first lenses with negative focal power, which are sequentially arranged from an object side to an image side along an optical axis, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a diaphragm, a fifth lens with negative focal power, a sixth lenswith positive focal power, a seventh lens with positive focal power and an eighth lens with positive focal power or negative focal power. The first lens, the third lens, the fifth lens and the sixthlens are all spherical lenses, and the fifth lens and the sixth lens form a cemented lens. The second lens, the fourth lens, the seventh lens and the eighth lens are aspheric lenses. The prime lens provided by the embodiment of the invention has the characteristic of ultra-large light flux, is particularly suitable for monitoring requirements under complex conditions, can achieve a large apertureof F0.8-1.2, supports an image plane of 1 / 1.8 inch, and can achieve a field angle range of 90-130 degrees.

Description

technical field [0001] Embodiments of the present invention relate to lens technology, and in particular to a fixed-focus lens. Background technique [0002] With the improvement of people's safety awareness, there are higher-level requirements for security, and surveillance cameras are born. Compared with the zoom lens, the design and manufacture of the fixed-focus lens are simple, and the image of the moving object is clear and stable, and the picture is delicate, so that it occupies an important position in the security monitoring industry. [0003] At present, image sensor manufacturers have launched 1 / 1.8-inch large image area low-light image sensors, which have better light receiving ability. However, existing technology lenses that can meet this requirement have problems such as false aperture, excessive volume, low yield, and only support a maximum of 2 megapixels. Therefore, small size, high cost performance, and 1 / 1.8 of the large aperture range Inch ultra-low il...

AI Technical Summary

Problems solved by technology

However, existing technology lenses that can meet this requirement have problems such as false aperture, excessive volume, low yield, and only support a maximum of 2 megapixels. Therefore, small size, high cost performance, and 1 / 1.8 of the large aperture range inch ultra-low light lens is necessary

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