Wide-angle camera lens with aspherical cemented lens

Abstract

The invention provides a wide-angle camera lens with an aspherical cemented lens. The wide-angle camera lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens in sequence from an object space to an image space, wherein the first lens, the second lens and the fourth lens have negative focal power, the third lens and the fifth lens have positive focal power, the fourth lens and the fifth lens are adhered together to form a cemented lens with the positive focal power, an adjoining plane of the cemented lens is at least a quadratic or above aspherical surface, the condition that BFL (Back Focal Length) / EFL (Effective Focal Length) is not smaller than 3.0 is also satisfied, BFL is a distance from an outermost point at the image space of a fifth lens element ofthe wide angle camera lens to an imaging plane, and EFL is a focal length value of the wide angle camera lens. The wide-angle camera lens can be used for realizing characteristics of a wide angle, small distortion, a large relative aperture, an ultra-long TTL (Total Length of Lens) and BFL under the condition of lower cost, and ensuring a comparatively perfect imaging definition within a wider temperature range, and is particularly suitable for outdoor monitoring under a relatively hostile environment and a vehicle-mounted camera system.

Description

technical field

[0001] The invention relates to a wide-angle lens with an aspheric cemented lens, which is especially suitable for monitoring cameras and vehicle-mounted image systems that require longer total lens length TTL and working distance BFL and wider operating temperature conditions. Background technique

[0002] At present, the wide-angle lens is generally composed of 5 to 8 lenses. For example, the wide-angle lens with the Chinese patent number 200910099703 is composed of 4 glass and 2 plastic lenses. However, the price of this wide-angle lens is relatively high, and it cannot meet customer requirements for low price and high performance. requirements. For this reason, there are also wide-angle lenses developed by Japanese companies that use aspheric technology to reduce costs. For example, the wide-angle lens with Chinese Patent No. 200880106079 is composed of 1 glass lens and 4 plastic lenses, but its light transmission performance is weak. The total length TT...

Examples

Embodiment Construction

[0027] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0028] The structure schematic diagram of the embodiment of the present invention relates to the wide-angle lens with aspheric cemented lens is as follows figure 1 As shown, the lens is composed of the first lens element L1, the second lens element L2, the third lens element L3, the stop r7, the fourth lens element L4 and the fifth lens element L5 from the object side to the image side in sequence. Lens group, color filter GF, imaging surface IMA. It is particularly applicable to vehicle-mounted camera systems with a viewing angle of about ≥130°.

[0029] The first lens element L1, which has negative optical power, is a glass lens element with spherical surfaces on both sides; the second lens element L2, which has negative optical power, is a plastic lens element with aspherical surfaces on both sides; the third lens Element L3, having positive optical powe...

technical field

[0001] The invention relates to a wide-angle lens with an aspheric cemented lens, which is especially suitable for monitoring cameras and vehicle-mounted image systems that require longer total lens length TTL and working distance BFL and wider operating temperature conditions. Background technique

[0002] At present, the wide-angle lens is generally composed of 5 to 8 lenses. For example, the wide-angle lens with the Chinese patent number 200910099703 is composed of 4 glass and 2 plastic lenses. However, the price of this wide-angle lens is relatively high, and it cannot meet customer requirements for low price and high performance. requirements. For this reason, there are also wide-angle lenses developed by Japanese companies that use aspheric technology to reduce costs. For example, the wide-angle lens with Chinese Patent No. 200880106079 is composed of 1 glass lens and 4 plastic lenses, but its light transmission performance is weak. The total length TT...

Examples

Embodiment Construction

[0027] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0028] The structure schematic diagram of the embodiment of the present invention relates to the wide-angle lens with aspheric cemented lens is as follows figure 1 As shown, the lens is composed of the first lens element L1, the second lens element L2, the third lens element L3, the stop r7, the fourth lens element L4 and the fifth lens element L5 from the object side to the image side in sequence. Lens group, color filter GF, imaging surface IMA. It is particularly applicable to vehicle-mounted camera systems with a viewing angle of about ≥130°.

[0029] The first lens element L1, which has negative optical power, is a glass lens element with spherical surfaces on both sides; the second lens element L2, which has negative optical power, is a plastic lens element with aspherical surfaces on both sides; the third lens Element L3, having positive optical powe...

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