Lens assembly and lens module incorporating the same

A lens assembly comprises a first lens and a second lens. The first lens includes a first central round portion and a first peripheral stepped portion surrounding the first central round portion. The first peripheral stepped portion comprises a downward-facing surface, a first supporting surface, and a first inclined surface interconnected. The second lens includes a second central round portion and a second peripheral stepped portion surrounding the second central round portion. The second peripheral stepped portion includes an upward-facing surface, a second inclined surface, a third surface, and a second supporting surface. The second lens is engaged on the first lens in a manner that the first supporting surface contacts the second supporting surface, the downward-facing surface is facing toward the upward-facing surface, the first inclined surface contacts the second inclined surface but a gap is defined between the first inclined surface and the third surface.

BACKGROUND

1. Technical Field

The present disclosure relates to an optical system, and particularly, to a lens assembly and a lens module incorporating the lens assembly.

2. Description of Related Art

Currently, along with the development of electronic devices with multiple functions, image capturing apparatuses have become widely used in a variety of consumer electronic devices, such as notebook computers, personal digital assistants (PDAs), and cellular telephones. In the meantime, there is an increasingly demand for improved image quality, which essentially depends on the quality of a lens module of the image capturing apparatus.

A lens module generally includes a barrel, a plurality of lenses received in the barrel. In addition, the plurality of lenses is assembled along an axis direction of the barrel in order to perform optical function. In order to ensure that the lenses can be precisely and firmly mounted inside the barrel, the lenses must be precisely manufactured with the external diameter substantially equal to the inner diameter of the barrel. However, the equal diameters may cause friction between the lateral sides of the lenses and the inside wall of the barrel, which makes it difficult to assemble the lenses with the barrel. Accordingly, the lenses may be placed improperly in the barrel. As a result, the assembling efficiency is lowered and the image quality of the yielded lens module is unsatisfactory. What is needed, therefore, is a lens assembly and a lens module, which can overcome the above shortcomings.

DETAILED DESCRIPTION

Embodiments of the present lens assembly and lens module incorporating the same will now be described in detail below and with reference to the drawings.

Referring toFIG. 1andFIG. 2, a lens assembly100in accordance with a first embodiment, is shown. The lens assembly100includes a first lens10and a second lens20. The first lens10and the second lens20can be made of plastic, glass or any other suitable optical materials.

The first lens10includes a first central round portion11and a first peripheral stepped portion12surrounding the first central round portion11. The first central round portion11is configured for performing image capturing function. The first peripheral stepped portion12includes a first radially extending portion120surrounding the first central round portion11, and a first axially extending portion126extending substantially axially from the first radially extending portion120.

The first peripheral stepped portion12has a downward-facing surface121, a first supporting surface123, and a first inclined surface122obliquely interconnected between the downward-facing surface121and the first supporting surface123. The downward-facing surface121is near the first central round portion11. The downward-facing surface121and the first supporting surface123are substantially perpendicular to the principal axis of the first lens10.

The second lens20includes a second central round portion21and a second peripheral stepped portion22surrounding the second central round portion22. The second central round portion21has the same function as the first central round portion11. The second peripheral stepped portion22includes a second radially extending portion220surrounding the second central round portion21, and a second axially extending portion226extending substantially axially from the second radially extending portion220.

The second peripheral stepped portion22has an upward-facing surface221, a second inclined surface222, and a third surface223, and a second supporting surface224. The second inclined surface222is interconnected between the upward-facing surface221and the third surface223. The upward-facing surface221and the second supporting surface224are perpendicular to the principal axis of the second lens20. The size of the first inclined surface122is larger than that of the second inclined surface222.

In assembly, the second lens20is engaged in the first peripheral stepped portion12of the first lens10in a manner that the first supporting surface123of the first lens10contacts the second supporting surface224of the second lens20. The downward-facing surface121of the first lens10is facing toward the upward-facing surface221of the second lens20. The first inclined surface122of the first lens10contacts the second inclined surface222of the second lens20but a gap200is defined between the first inclined surface122and the third surface223. A spacer30is interposed between the downward-facing surface121of the first lens10and the upward-facing surface221of the second lens20.

Expressly, an angle between the second inclined surface222of the second lens20and the principal axis of the second lens20is larger than an angle between the third inclined surface223and the principal axis of the second lens20. The degrees of the angle between the second inclined surface222of the second lens20and the principal axis of the second lens20is larger than 0 degrees and smaller than 90 degrees. Expressly, the third surface223is substantially parallel with or inclined relative to the principal axis of the second lens20.

In the present embodiment, because the gap200can hold air during the assembly of the first lens10and the second lens20, the pressure of the first lens10and the second lens20is adjusted, the deformation of the first lens10and the second lens20that is influenced by the friction is greatly reduced.

It is noteworthy that the downward-facing surface121of the first lens10could contact the upward-facing surface221of the second lens20.

In the first embodiment, the lens assembly100can be installed into the electronic devices, such as notebook computers, personal digital assistants (PDAs), or cellular telephones.

Referring theFIG. 3, a lens module1in accordance with a second embodiment, is shown. The lens module1includes a barrel2and the lens assembly100, and includes a third lens40, a forth lens50, a sensor60, and a spacer70. The spacer70is interposed between the third lens40and the forth lens50. The sensor60is positioned on image side of the barrel2.

The barrel2is a cylindrical barrel and can be made of resin. The barrel2defines an inner space (not labeled) therein to accommodate the first lens10, the second lens20, the third lens40, the forth lens50and the spacer70.

The light passes through the first lens10, the second lens20, the third lens40, the forth lens50, and is captured on the sensor60.

It is understood that the above-described embodiments are intended to illustrate rather than limit the disclosure. Variations may be made to the embodiments and methods without departing from the spirit of the disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.