Patent Application
20140204481
1. Field of the Invention
This invention relates to a lens module, and more particularly to a lens module used in mobile electronic products.
2. The Related Art
With the popularity of camera phones, the quality of photography has become one of the main considerations for consumers to purchase a new mobile phone having a lens module therein. In order to make photographic quality of the lens module better and the size and the weight of the mobile phone slimmer, the allowable error value of assembling optical lens of the lens module is also getting strict. Take a general two-megapixel camera lens for an example, the eccentric error while assembling the optical lenses must be less than 3 μm.
Referring to
In view of these disadvantages above, the structure of the conventional lens module needs to be improved.
An objective of this invention is to provide a lens module with high assembling accuracy and high production yield. An optical axis passes through the lens module from an object side to an image side. The lens module includes a lens housing, a first lens and a second lens which are disposed in the lens housing from the object side to the image side in sequence.
The first lens has a first refract portion through which the optical axis passes and a first positioning portion away from the optical axis and encircling the first refract portion. A first jointing structure is annularly formed on the image side surface of the first positioning portion and molded with the first refract portion as a single integral. The second lens has a second refract portion through which the optical axis passes and a second positioning portion away from the optical axis and encircling the second refract portion. A second jointing structure is annularly formed on the object side surface of the second positioning portion and molded with the second refract portion as a single integral. The first jointing structure and the second jointing structure are engaged with each other to align the first lens and the second lens along the optical axis, and the first refract portion of the first lens and the second refract portion of the second lens are coaxial with each other and have the axis as the optical axis.
As described above, each of the positioning portions and the jointing structures in this invention are molded with the refract portions as a single integral, so the positioning portion and the jointing structure have less manufacturing tolerance. Therefore, the lenses are capable to be assembled with high assembling accuracy together so that avoids relative positioning deviation of the lens caused by the manufacturing error of the lens housing, and improves the production yield of the lens module.
The present invention will be apparent to those skilled in the art by reading the following description, with reference to the attached drawings, in which:
With reference to
The first lens 20 has a first refract portion 21 through which the optical axis 13 passes and a first positioning portion 22 away from the optical axis 13 and encircling the first refract portion 21. The first lens 20 is arranged and fixed to the lens housing 10 by means of the first positioning portion 22. A first jointing structure 23 is annularly formed on the image side surface of the first positioning portion 22. The first jointing structure 23 is molded with the first refract portion 21 as a single integral, so the first jointing structure 23 has the same great manufacturing precision as producing optical-component, and has very low manufacturing error.
The second lens 30 has a second refract portion 31 through which the optical axis 13 passes and a second positioning portion 32 away from the optical axis 13 and encircling the second refract portion 31. A second jointing structure 33 is annularly formed on the object side surface of the second positioning portion 32, and also molded with the second refract portion 31 as a single integral, so the second jointing structure 33 also has the same great manufacturing precision as producing optical-component, and has very low manufacturing error. The first jointing structure 23 and the second jointing structure 33 are engaged with each other to align the first lens 20 and the second lens 30 along the optical axis 13. The first refract portion 21 of the first lens 20 and the second refract portion 31 of the second lens 30 are coaxial with each other and have the axis as the optical axis 13.
Since the first lens 20 and the second lens 30 are positioned by engaging the first jointing structure 23 with the second jointing structure 33, so the manufacturing error of the lens housing 10 will not affect the eccentric error between the first lens 20 and the second lens 30. Moreover, the jointing structures 23, 33 are respectively molded with the refract portions 21, 31 as a single integral by optical molds that are used for casting optical lenses, so the manufacturing error of the jointing structure 23, 33 is very small, and it effectively reduces the eccentric error between the first lens 20 and second lens 30.
In this embodiment, the total quantity of lenses are three. A third jointing structure 38 is formed on the image side surface of the second lens 30, and a fourth jointing structure 41 is formed on the object side surface of the third lens 40. The third lens 40 is fixed with the second lens 30 by jointing the fourth jointing structure 41 with the third jointing structure 38. The third jointing structure 38 and the fourth jointing structure 41 are also molded with optical mold that is used for casting optical lenses, so the manufacturing error can also be minimized. But in use, the quantity of lenses is adjustable according to the requirement, and should not be limited to three.
Referring to
When the second jointing structure 33 joints with the first jointing structure 23, the guiding slope 26 and the guiding face 36 cooperate with each other to guide the second lens 30 to align with the first lens 20 automatically along the optical axis 13. When the first jointing structure 23 is completely jointed with the second jointing structure 33, the first refract portion 21 of the first lens 20 and the second refract portion 31 of the second lens 30 are coaxial with each other and have the axis as the optical axis 13. The outer sidewall 25 abuts against the inner wall 35 to keep the first lens 20 and the second lens 30 coaxial, and the resisting face 24 resists against the stopping face 34 to keep the distance between the first lens 20 and the second lens 30 constant.
As described above, each of the positioning portions 22, 32 and the jointing structures 23, 33 are molded with the refract portions 21, 31 integrally, so the positioning portions 22, 32 and the jointing structures 23, 33 are manufactured in high manufacturing precision. Therefore, the lenses 20, 30 are capable to be assembled with high assembling accuracy together so that avoids relative positioning deviation of the lenses 20, 30 caused by the manufacturing error of the lens housing 10, and improves the production yield of the lens module.
