LENS ASSEMBLY FOR ELECTRONIC DEVICE

A lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are sequentially arranged from an object side to an image side. The lens assembly satisfies the following relationships:  |PVS1-S6|≤0.3;  |PVS7−PVS8|≤|PVS11−PVS12|≤1;  |PVS1/PVS12|≤3; PV is an error between an actual surface shape and a standard surface shape of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens. PVSn is an error of crests and troughs between an actual surface shape and a standard surface shape of the first surface to an nth surface, and n is a positive integer less than 13.

FIELD

The subject matter herein generally relates to lens assemblies, and more particularly to a lens assembly for an electronic device.

BACKGROUND

Injection-molded plastic lenses generally have the advantages of low manufacturing cost and rapid mass production and are widely used. The injection-molded plastic lens may have different mold processing or mold condition parameters, which may cause the actual surface shape of the molded lens to be different from the originally designed lens. Ideally, the face of the actual molded lens should be the same as the designed face. However, due to the limitation of processing and molding technology, it is not easy for the actual molded lens to be exactly the same as the designed face. The surface shape of the actual molded lens is likely to be different from the designed lens surface due to processing errors and unstable molding, which will affect the imaging quality of the lens assembly, reduce yield, and increase process costs.

DETAILED DESCRIPTION

FIG. 1shows an embodiment of a lens assembly100. In one embodiment, the lens assembly100includes a first lens10, a second lens20, a third lens30, a fourth lens40, a fifth lens50, a sixth lens60, a filter70, and an image surface80arranged in sequence from an object side to an image side.

The lens assembly100includes an optical axis110. The first lens10, the second lens20, the third lens30, the fourth lens40, the fifth lens50, and the sixth lens60are all symmetrically arranged about the optical axis110.

The first lens10has a negative refractive power and includes a first surface101and a second surface102. The first surface101protrudes toward the object side, and the second surface102is a flat surface.

The second lens20has a positive refractive power. The second lens20includes a third surface201and a fourth surface202. The third surface201is a flat surface facing the second surface102, and the fourth surface202is recessed toward the object side.

The third lens30has a positive refractive power. The third lens30includes a fifth surface301and a sixth surface302. The fifth surface301is recessed toward the image side, and the sixth surface302protrudes toward the image side.

The fourth lens40has a positive refractive power. The fourth lens40includes a seventh surface401and an eighth surface402. The seventh surface401faces the sixth surface302. Two ends of the seventh surface401are flat surfaces, and a middle portion of the seventh surface401is recessed toward the image side. The eighth surface402protrudes toward the image side.

The fifth lens50has a negative refractive power. The fifth lens50includes a ninth surface501and a tenth surface502. The ninth surface501faces the eighth surface402. Two ends of the ninth surface501are flat surfaces, and a middle portion of the ninth surface501is recessed toward the image side. The tenth surface502protrudes toward the image side. A thickness of a middle portion of the fifth lens50is greater than a thickness of the two ends.

The sixth lens60has a positive refractive power. The sixth lens60includes an eleventh surface601and a twelfth surface602. The eleventh surface601faces the tenth surface502. Two ends of the eleventh surface601are flat, and a middle portion of the eleventh surface601is recessed toward the image side. Two ends of the twelfth surface602protrude toward the image side, and a middle portion of the twelfth surface is recessed toward the object side. A thickness of the middle portion of the sixth lens60is smaller than a thickness of the two ends.

The first lens10, the second lens20, the third lens30, the fourth lens40, the fifth lens50, and the sixth lens60are aspherical lenses that satisfy the following formula:

wherein:
z is a concavity of an aspheric surface;
c is a reciprocal of a radius of curvature;
r is an off-axis radius;
k is a conic coefficient;
A4, A6, A8, A10, A12, A14, A16, A18, A20, A22 are order coefficients of the aspheric surface.

The filter70is used to filter infrared light in a light passing through the sixth lens60. The filter70includes a front surface71and a rear surface72opposite the front surface.

The image surface80is used for imaging.

The lens assembly100satisfies the following relationships:

wherein:
PV is an error between an actual surface shape and a standard surface shape of the first lens10, the second lens20, the third lens30, the fourth lens40, the fifth lens50, and the sixth lens60;
PVSnis an error of crests and troughs between an actual surface shape and a standard surface shape of the first surface to an nth surface, and n is a positive integer less than 13.

Referring toFIG. 2, taking the seventh surface401and the eighth surface402as an example, the first surface101and the second surface102, the third surface201and the fourth surface202, the fifth surface301and the sixth surface302, the seventh surface401and the eighth surface402, the ninth surface501and the tenth surface502, and the eleventh surface601and the twelfth surface602are u-n-type or n-u-type pairs.

Referring toFIG. 3, light rays L for each field of view pass through nearly an entire surface of the lens closest to the object side (the first lens10), and the light rays L for each field of view only pass through a portion of a surface of the lens closest to the image side (the sixth lens60). The lens closest to the object side is sensitive to all fields of view, which will easily affect an overall imaging quality of the lens. Therefore, the PV value of the lens closest to the object side is controlled in a smaller range. The lens closest to the image side is sensitive to peripheral fields of view. Therefore, the PV value of the lens closest to the image side is controlled in a larger range.

The lens assembly100will be described in detail below in specific embodiments.

Referring toFIG. 4, it can be seen that MTF peak values of the lens assembly100of Embodiment 1 and Embodiment 2 from a center field of view to a peripheral field of view of 0.8 do not differ far from standard design values (the MTF peak differences are less than 5%).

Referring toFIG. 5, it can be seen that MTF peak values of the lens assembly100of Embodiment 3 and Embodiment 4 from a center field of view to a peripheral field of view of 0.8 differ far from standard design values (the MTF peak differences are greater than 5%), such as if conditions are exceeded, the MTF peak values will decrease due to PV errors.

As shown inFIG. 6, the present application further provides an electronic device200including the lens assembly100. The electronic device200includes a body210, and the lens assembly100is arranged in the body210. The electronic device200may be a mobile phone, a notebook computer, a desktop computer, a game console, or the like.

In summary, the difference between the actual surface shape and the standard surface shape of each surface of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens is restricted to effectively improve the imaging effect of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens. The first surface and the second surface, the third surface and the fourth surface, the fifth surface and the sixth surface, the seventh surface and the eighth surface, the ninth surface and the tenth surface, and the eleventh surface and the twelfth surface are designed to be u-n-type or n-u-type pairs, so that the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens have complementary effects, thereby further improving imaging quality.