CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No. PCT/CN2017/110445, filed on Nov. 10, 2017, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

This application relates to the field of technologies for optical modules in camera apparatuses, and in particular, to a lens assembly.

BACKGROUND

In a lens assembly of a mobile terminal such as a digital camera, a camera device, and a mobile phone, interference is present between a lens barrel and a lens assembled within. However, excessive interference between the lens barrel and the lens may deform the lens, degrading a resolving power of the lens assembly and affecting the quality of photography. A direction of studies in the industry is how to design making the interference between the lens and the lens barrel within an expected range without causing deformation on the lens while ensuring the resolving power of the lens assembly and the quality of photography.

SUMMARY

Embodiments provide a lens assembly, a camera module, and a terminal to resolve problems of lens deformation and degraded imaging quality caused by large assembly interference between a lens barrel and a lens.

According to a first aspect, this application provides a lens assembly, including a lens barrel and a lens. The lens barrel is hollow and includes an interior surface. In an embodiment, the lens barrel has a tubular shape with openings at both ends. An accommodation space formed by the surrounding interior surface is used to install the lens. A central axis of the lens barrel is an optical axis of the lens assembly. The lens is disposed inside the lens barrel, and the lens includes a side surface in interference fit with the interior surface. For example, a central area of the lens is a light-transmitting area, an edge area of the lens surrounds the central area, and the edge area is used to assemble the lens into the lens barrel. The side surface is an exterior surface of the edge area that fits the lens barrel, and the side surface is in contact and interference fit with the interior surface of the lens barrel. The interior surface of the lens barrel has a hollow area. The hollow area may be a groove of any shape, such as a square groove, a curved groove, a semicircular groove, a triangular groove, or an irregular shape. The hollow area is a concave area formed in an inner wall of the lens barrel by removing materials. The hollow area may alternatively be an area formed by a plurality of fine-stripe channels or slits. The side surface includes a micro-convex structure, where the micro-convex structure in the side surface of the lens is an irregular surface protrusion structure that appears on the lens during processing. For example, the side surface of the lens should be theoretically designed as a cylindrical surface. However, during manufacturing, the micro-convex structure is inevitably formed on the side surface of the lens because of reasons such as mould structure and processing art. In the embodiments, a fit quantity between the micro-convex structure and the hollow area is changed through relative rotation of the lens and the lens barrel, to adjust assembly interference between the lens barrel and the lens. After the lens is installed into the lens barrel, the side surface is in interference fit with the interior surface. Relatively large interference may cause deformation of the lens and affect imaging quality. In this application, at least a portion of the micro-convex structure is moved into the hollow area by rotating the lens. That is, the hollow area absorbs some interference between the micro-convex structure and the interior surface. When the micro-convex structure is completely accommodated in the hollow area, interference between the lens and the lens barrel is minimum. In this application, an amount of deformation of the lens is controlled by reducing the interference between the lens and the lens barrel, thereby ensuring the imaging quality.

In an implementation, the hollow area is filled with a cushioning material, and the lens is in contact with the cushioning material in the hollow area, to absorb the assembly interference between the lens and the interior surface of the lens barrel. The cushioning material may be a material characterized by elastic cushioning, such as glue, foam, and silicone.

There are a plurality of hollow areas. The plurality of hollow areas are separated from each other, arranged along a periphery of the lens, and directly facing the side surface of the lens. The arranging of two or more than two hollow areas can improve efficiency of interference between the lens and a camera, so that the micro-convex structure can quickly fit a hollow area during rotation of the lens. Further, a quantity of micro-convex structures on the side surface of the lens is not limited to only one. There may be two or more micro-convex structures. In this way, two or more micro-convex structures fit two or more hollow areas, which can adjust the interference between the lens and the lens barrel to a greater extent.

In an implementation, the hollow area includes a first hollow area and a second hollow area, where the first hollow area is one or more first hollow structures, and the second hollow area is one or more second hollow structures. The lens includes a top lens, a bottom lens, and at least one middle lens stacking between the top lens and the bottom lens, where the top lens and the bottom lens are both in interference fit with the lens barrel, and the at least one middle lens is in clearance fit with the lens barrel. The at least one first hollow structure fits a micro-convex structure of the top lens, and the at least one second hollow structure fits a micro-convex structure of the bottom lens.

In this implementation, a multi-layer lens structure is determined. After positions of the top lens and the bottom lens are determined, a position of the middle lens is fixed. Therefore, clearance interference between the middle lens and the lens barrel can ensure that the middle lens is not deformed due to the assembly interference. The top lens may be a one-layer or two-layer lens structure. The bottom lens may be also a one-layer or two-layer lens structure.

In an implementation, a glue chute is arranged in the lens barrel, where the glue chute extends from an end face of the lens barrel to the hollow area, and the glue chute is configured to fill glue into the hollow area after the lens is assembled into the lens barrel. Filling glue in the glue chute can improve a strength and overall rigidity of the lens assembly, avoiding displacement or deformation of the lens.

In an implementation, the glue chute includes a first glue chute and a second glue chute, where the first glue chute extends from a top end face of the lens barrel to the hollow area that fits the top lens, and the second glue chute extends from a bottom end face of the lens barrel to the hollow area that fits the bottom lens. In this implementation, two glue chutes are provided to dispense glue for the top lens and the bottom lens so as to fill glue in the hollow area. This makes glue filling easy without affecting the middle lens.

In an implementation, a connection channel is further disposed on the inner wall of the lens barrel. The plurality of first hollow structures are connected to each other through the connection channel, and the second hollow structures are connected to each other through the connection channel.

The hollow area includes a groove or a plurality of slits that are adjacent to each other and arranged in parallel.

In an implementation, each of the plurality of slits are arranged in parallel in an axial direction of the lens barrel, and are correspondingly arranged along a peripheral of the top lens or the bottom lens.

In other words, a hollow area at one position may be a structure including a complete groove or a structure including a plurality of slits.

According to a second aspect, an embodiment further provides a camera module, including a circuit board, a chip, a light filter, and the lens assembly according to any one of the foregoing implementations, where the chip is disposed on a top surface of the circuit board, the light filter is fixed on the bottom surface of the lens barrel of the lens assembly, with the bottom surface of the lens barrel connected to the top surface of the circuit board, and the chip is disposed opposite to the lens.

According to a third aspect, an embodiment further provides a terminal, including the camera module.

