Camera lens group of three pieces type

Abstract

The invention relates to a three-sheet type video lens group to capture high quality image. The three sheet type video lens group is made up of the first lens that is positive refraction power bend moon type lens, the second lens setting at the back of the first lens and is the positive refraction power bend moon type lens and the third lens setting at the back of the second lens is the positive refraction power bend moon type lens toward object side. The compound focus is f, and the compound focus of the first and the second lens is f12, thus, it satisfies the conditional expression of 1.0 G02B 9 / 12 G02B 1 / 04 14 10 1 2005 / 5 / 30 1873459 2006 / 12 / 6 100498410 2009 / 6 / 10 2009 / 6 / 10 2009 / 6 / 10 Dali Photoelectric Co., Ltd. Taiwan Yetian Xiaobaihe wang mengxia yu changhua 11223

Description

technical field [0001] The invention relates to a photographic lens group used in a small image-taking device, which is related to the single-focus lens group of a general small-sized image-taking device, and in particular refers to a combination composed of three plastic lenses. Background technique [0002] The photographic lens group composed of three lenses has the following eight configurations of refractive power; (A) positive. negative. positive (B) positive. positive. negative (C) positive. positive. positive (D) positive. negative .Negative (E) Negative. Positive. Positive (F) Negative. Positive. Negative (G) Negative. Negative. Positive (H) Negative. Negative. G and H), the rear focal length is too long to meet the demands of compactness and lightness, and cannot be used because it does not meet the needs of small and light portable devices, so in fact, the four refractive power configurations (A) to (D) are the best. The design is mainstream and meets the needs o...

AI Technical Summary

Problems solved by technology

[0011] As mentioned above, the combination of three lenses is the same as A) and is often used, but the telephoto ratio T / F is above 1.4, which is not suitable for shortening the total optical length. The telephoto mode of sample B) and D) is more favorable, and the number of lenses in the telephoto mode is less (2 or 3), and it is developed on the photographic lens group for silver salt cameras, because the rear group It is difficult to achieve wide-angle with negative refraction power, so it is not suitable for the optical system that requires wide-angle in the later group, and the incident angle part, the above-mentioned photography lens group is not suitable for CCD solid-state camera.

[0012] The negative refractive power lens is the reverse telephoto lens module of (E) to (H) in the first lens form. The VGA formed by these two lenses is only used in digital cameras and portable terminals with 300,000 to 400,000 pixels. The photographic lens module used, and the reverse focus mode, and the shortening of the optical total length are not feasible, so the composition of more than three lenses has not been used in simple digital cameras

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