Zoom lens, image pickup device and information carrying terminal device

Abstract

The invention provides a zoom lens which can realize high video quality, has a half-image angle of more than 42o, can make the F numerical value at the short focus end below 3.0 and is fully miniaturized, a photographing device and a terminal device for carrying intelligence. From the object side, a first lens group which has positive focal distance, a second lens group which has minus focal distance, a third lens group which has positive focal distance, and a fourth lens group which has positive focal distance are orderly arranged; the object side of the third lens group is provided with an aperture; when the aperture doubles from the short focus end to the long focus end, the space between the first lens group and the second lens group increases, while the space between the second and the third lens groups decreases and the space between the third and the fourth lens groups changes; the third lens group is orderly provided with a positive lens L31, a minus lens L32, a positive lens L33 and a minus lens L34 from the object side; the concave faces of the image side of the minus lens L32 and the image side of the minus lens L34 face towards the image side; the object sides of the positive lens L31 and the minus lens L32 are convex faces facing towards the object side.

Description

technical field [0001] The present invention relates to a zoom lens, a photographing device, and a portable information terminal device having an improved photographic optical system, which can be applied to digital cameras, mobile phones with camera functions, video cameras, and the like. Background technique [0002] In recent years, it is called a digital camera or an electronic camera, and the subject image is captured by a solid-state imaging element such as an imaging element composed of a CCD (charge-combined device) or a C-MOS image detector, to obtain an image of the subject. Still images (still images) or moving images (movie images), which are recorded in non-volatile semiconductor memory represented by flash memory, etc., digital recording cameras have become popular, while the previous ones used silver salt film The original camera (ie silver salt camera) is gradually being phased out. [0003] The market for such digital cameras is very large, and users' requi...

AI Technical Summary

Problems solved by technology

[0007] In the zoom lenses described in the above four patent documents, since the object side of the second lens set at the second position from the object side of the third lens group composed of four lenses is a concave surface, the It is not a convex surface, so the F number at the short focal point end cannot be lower than 3.0, and it cannot achieve a wide image angle with a half image angle of 42° or more

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