LENS MODULE

• US 20130063831A1
• Filed: 04/25/2012
• Published: 03/14/2013
• Est. Priority Date: 09/08/2011
• Status: Active Grant

• Current Assignee: Wcube Co., Ltd. (Foxconn Technology Co., Ltd.)
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: LIN, TSUNG-YU
• Granted Patent: US 8,749,902 B2
• Time in Patent Office: Days
• US Class Current: 359/823
• CPC Class Codes: G02B 13/0035 having three lenses
• CPC Class Codes: G02B 3/00 Simple or compound lenses
• CPC Class Codes: G02B 3/0081 having one or more elements with analytic function to create variable power variable magnification in general G02B15/00
• CPC Class Codes: G02B 7/021 for more than one lens
• CPC Class Codes: G02B 9/12 having three components only

Abstract

A lens module comprises a barrel, a first lens, a first spacer ring, a second lens having an effective aperture A, a second spacer ring having an inner diameter B, and a third lens having an effective aperture C. The first lens, the first spacer ring, the second lens, the second spacer ring, the third lens and the infrared cut-off filter are coaxially assembled within the barrel, along an axial direction of the barrel in that order. The first spacer ring is sandwiched between the first lens and the second lens, the second spacer ring is sandwiched and located between the second lens and the third lens. The inner diameter B of the second spacer ring is smaller than the effective aperture C of the third lens and larger than the effective aperture A of the second lens, so as to satisfy the condition of C>B>A.

Claims

1. A lens module, comprising:

a barrel;

a first lens;

a first spacer ring;

a second lens having an effective aperture A;

a second spacer ring having an inner diameter B; and

a third lens having an effective aperture C;

wherein, the first lens, the first spacer ring, the second lens, the second spacer ring, the third lens and the infrared cut-off filter are coaxially assembled within the barrel, along an axial direction of the barrel in that order;

the first spacer ring is sandwiched between the first lens and the second lens, the second spacer ring is sandwiched and located between the second lens and the third lens;

the inner diameter B of the second spacer ring is smaller than the effective aperture C of the third lens and greater than the effective aperture A of the second lens.

2. The lens module of claim 1, wherein the effective aperture C of the third lens, the inner diameter B of the second spacer ring, and the effective aperture A of the second lens

meet the relationships presented in the following equations:

3. The lens module of claim 1, wherein the effective aperture C of the third lens is 0.876 mm, the effective aperture A of the second lens 14 is0.607 mm;

the inner diameter B of the second spacer ring is 0.78 mm, 0.774 mm or 0.764 mm.

4. The lens module of claim 1, further comprising an infrared cut-off filter, wherein the infrared cut-off filter is assembled within a distal end of the barrel, away from the first lens, and resists against the corresponding third lens, coaxially.

5. The lens module of claim 4, further comprising an image sensor and a lens base adjustably assembled to the barrel, wherein the image sensor is assembled within the lens base and coaxially positioned in front of the corresponding infrared cut-off filter.

6. The lens module of claim 5, wherein one end of the barrel is received into and rotatably engaging with a top end of the lens base, such that, the barrel is rotatable relative to the lens base and is capable of being axially adjusted relative to the lens base thereby changing a length of the whole lens module.

7. The lens module of claim 6, wherein the barrel is adjustably assembled to the lens base via screw thread engagement.

8. A lens module, comprising:

a barrel;

a lens base coaxially and rotatably assembled to one end of the barrel;

a first lens;

a first spacer ring;

a second lens having an effective aperture A;

a second spacer ring having an inner diameter B; and

a third lens having an effective aperture C;

wherein, the first lens, the first spacer ring, the second lens, the second spacer ring, the third lens and the infrared cut-off filter are coaxially assembled within the barrel, along an axial direction of the barrel toward the lens base in that order;

the first spacer ring is sandwiched between the first lens and the second lens, the second spacer ring is sandwiched and located between the second lens and the third lens;

wherein, the inner diameter B of the second spacer ring is smaller than the effective aperture C of the third lens and greater than the effective aperture A of the second lens.

9. The lens module of claim 8, further comprising an infrared cut-off filter and an image sensor, wherein the infrared cut-off filter is assembled within the barrel, away from the first lens, and resists against the corresponding third lens, coaxially;

the image sensor is assembled within the lens base and coaxially positioned in front of the corresponding infrared cut-off filter.

10. The lens module of claim 9, wherein one end of the barrel is rotatably engaging into a top end of the lens base, the barrel is capable of being axially adjusted relative to the lens base thereby changing a distance between the image sensor and the barrel, and adjusting a whole length of the lens module.

11. The lens module of claim 10, wherein the barrel is adjustably assembled to the lens base via screw thread engagement.

12. The lens module of claim 10, wherein the effective aperture C of the third lens, the inner diameter B of the second spacer ring, and the effective aperture A of the second lens meet the relationships presented in the following equations: