Note: Simple hysteresis parameter inspector for camera module with liquid lens.
A method to inspect hysteresis parameter is presented in this article. The hysteresis of whole camera module with liquid lens can be measured rather than a single lens merely. Because the variation in focal length influences image quality, we propose utilizing the sharpness of images which is captured from camera module for hysteresis evaluation. Experiments reveal that the profile of sharpness hysteresis corresponds to the characteristic of contact angle of liquid lens. Therefore, it can infer that the hysteresis of camera module is induced by the contact angle of liquid lens. An inspection process takes only 20 s to complete. Thus comparing with other instruments, this inspection method is more suitable to integrate into the mass production lines for online quality assurance.
Instrument Technology Research Center, National Applied Research Laboratories, 20, R&D Rd. VI, Hsinchu Science Park, Hsinchu 300, Taiwan. proray@itrc.org.tw
Po-Jui
PJ
Chen
Tai-Shan
TS
Liao
Chi-Hung
CH
Hwang