1. Technical Field
The present disclosure relates to lens modules and, particularly, to an apparatus for detecting stray light in a lens module.
2. Description of Related Art
With the development of optical imaging technology, image capturing devices are widely used in electronic devices, such as digital cameras, mobile phones, etc. Naturally, there is always a demand for better quality pictures.
A lens module is an important component in these image capturing devices, and the quality of the lens module usually determines the quality of images captured by these image capturing devices. Therefore, it is important to detect stray light in a lens module for evaluating the quality of the image capturing device. Prior apparatuses for detecting stray light in lens modules usually only detect the stray light corresponding to a certain angle, and the stray light in the lens module corresponding to other angles are not taken into account, which results in less accurately determining the quality of the lens module.
What is needed, therefore, is an apparatus for detecting stray light in lens module which can solve the above problems.
Embodiments will now be described in detail below with reference to the drawings.
Referring to
The protractor dial 20 includes an origin point 201 and a plurality of scale lines 202 extending radially from the origin point 201.
The supporting seat 30 is arranged on the top surface 101 at the origin point 201 of the protractor dial 20 for supporting the lens module 200. In the present embodiment, the supporting seat 30 is fixed on the top surface 101.
Referring also to
The worktable 10 also includes an opening 103 defined in a side surface 102 of the worktable 10. The side surface 102 is adjoining the top surface 101. The opening 103 communicates with the track 40, thereby allowing the supporting seat 50 to conveniently be installed into the track 40.
Preferably, the top surface 101 of the worktable 10 further defines a groove 104 parallel and communicating with the track 40. A first fixing member 105 (see
The supporting seat 50 is movable in the track 40. Referring to FIG. 3, the supporting seat 50 includes a bottom supporting portion 501, a top supporting portion 502 arranged on the bottom supporting portion 501 and movable relative the bottom supporting portion 501, and a second fixing member 503.
The bottom supporting portion 501 is moveable in the track 40. The bottom supporting portion 501 includes a bottom 5011, and a hollow receiving body 5013 arranged on the bottom 5011. A receiving cavity 5015 is defined in the receiving body 5013. The receiving cavity 5015 is configured for receiving the top supporting portion 502. A receiving hole 5017 communicating with the receiving cavity 5015 is defined in the side wall of the receiving cavity 5015. The receiving hole 5017 is configured for receiving the second fixing member 503.
In the present embodiment, the bottom 5011 is round in shape, and the hollow receiving body 5013 is a cylindrical body. The diameter of the bottom 5011 is slightly larger than the radial width of the bottom portion of the track 40. The outer diameter of the receiving body 5013 is slightly larger than the radial width of the top portion of the track 40.
The top supporting portion 502 includes a supporting stage 5021 for supporting the light source 60, and a supporting body 5023 arranged on the bottom surface of the supporting stage 5021 for supporting the supporting stage 5021. The supporting body 5023 is received in the receiving cavity 5015, and is movable relative to the receiving body 5013.
The second fixing member 503 is detachable from the bottom supporting portion 501, and is configured for fixing the supporting body 5023 at a certain height relative to the top surface 101. When the second fixing member 503 is tightly received in the receiving hole 5017, and contacts with the supporting body 5023, the supporting body 5023 will be fixed at a certain height relative to the top surface 101 by the second fixing member 503. In the present embodiment, the second fixing member 503 is a screw, and the receiving hole 5017 is a threaded hole. In alternative embodiments, the second fixing member 503 may be a cylindrical body with a slippery outer sidewall. In further alternative embodiments, the second fixing member 503 may be inserted into the receiving cavity 5015 along the direction parallel with the lengthwise direction of the receiving body 5013, and be tightly sandwiched between the outer sidewall of the supporting body 5023 and the inner wall of the receiving body 5013, thereby fixing the supporting body 5023 at a certain height relative to the top surface 101.
The light source 60 is movable along the track 40 and rotatable on the track 40, and configured for emitting light along a scale line 202 towards the lens module 200. In the present embodiment, the light source 60 is an incandescent lamp. In other embodiments, the light source 60 may be a light emitting diode, or another kind of light source.
The pick-up unit 70 is disposed at an image-side of the lens module 200 for capturing images of the light from the light source through the lens module 200 at respective different incident angles relative to the optical axis (not shown) of the lens module 200, and delivering the image to the process unit 80. The pick-up unit 70 can be a charge-coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The pick-up unit 70 can be selected from a group consisting of ceramic leaded chip carrier (CLCC) package type image pick-up units, plastic leaded chip carrier (PLCC) package type image pick-up units, and chip scale package (CSP) type image pick-up units.
The process unit 80 is electrically connected with the image pick-up unit 70. The process unit 80 receives the images from the image pick-up unit 70, analyzes the images, determines the incident angles where stray light occurs in the lens module 200, and measures an intensity of the stray light at the corresponding incident angle. In other embodiments, the process unit 80 may be omitted. In such case, images from the image pick-up unit 70 at respective different incident angles can be analyzed by a person to determine whether stray light occurs at the corresponding incident angles and how the corresponding stray light is formed.
The scale lines 202 can accurately indicate the incident angles between light from light source 60 and the optical axis of the lens module 200 when the stray light occurs. The reason of the occurrence of the stray light can thus be accurately analyzed. In addition, the height between the supporting stage 5021 and the bottom 5011 can be adjusted. The apparatus 100 can thus detect stray light in different kinds of lens modules (i.e. different heights of lens modules). Accordingly, the use rate of the apparatus 100 is improved.
A method for detecting stray light in the lens module 200 includes the following steps.
The apparatus 100 is provided, and the lens module 200 is positioned on the supporting seat 30.
The supporting seat 50 is positioned in the track 40 from the opening 103, and the light source 60 is positioned on the supporting seat 50.
It is then determined whether the light source 60 is substantially coplanar with the lens module 200. If the light source 60 is not substantially coplanar with the lens module 200, the second fixing member 503 can be detached from the receiving hole 5017, and the supporting body 5023 is moved along the lengthwise direction of receiving body 5013 until the light source 60 is substantially coplanar with the lens module 200. Then, the light source 60 is rotated, thereby making the light source 60 emit light along a scale line towards the lens module 200. Next, the second fixing member 503 is tightly received in the receiving hole 5017, and contacts with the supporting body 5023.
Then, the supporting seat 50 is moved in the track 40, and the pick-up unit 70 senses lights from the lens module 200 corresponding to many incident angles, forms images corresponding to many incident angles, and delivers the corresponding images to the process unit 60.
The process unit 80 receives the images, analyzes the images, determines the incident angles where stray light occurs in the lens module 200, and measures an intensity of the stray light at the corresponding incident angle.
While certain embodiments have been described and exemplified above, various other embodiments will be apparent to those skilled in the art from the foregoing disclosure. The disclosure is not limited to the particular embodiments described and exemplified but is capable of considerable variation and modification without departure from the scope and spirit of the appended claims.
Number | Date | Country | Kind |
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99113765 | Apr 2010 | TW | national |