In mobile lens domain, the glass lens is often to be applied in high-resolution requirement situation; but the glass zoom
lens needs to be collocated with movable machinery and voice-coil motor, which usually arises some space limits in
minimum design. In high level molding component technology development, the appearance of liquid lens has become
the focus of mobile phone and digital camera companies. The liquid lens sets with solid optical lens and driving circuit
has replaced the original components. As a result, the volume requirement is decreased to merely 50% of the original
design. Besides, with the high focus adjusting speed, low energy requirement, high durability, and low-cost
manufacturing process, the liquid lens shows advantages in the competitive market. In the past, authors only need to
inspect the scrape defect made by external force for the glass lens. As to the liquid lens, authors need to inspect the state
of four different structural layers due to the different design and structure. In this paper, authors apply machine vision
and digital image processing technology to administer inspections in the particular layer according to the needs of users.
According to our experiment results, the algorithm proposed can automatically delete non-focus background, extract the
region of interest, find out and analyze the defects efficiently in the particular layer. In the future, authors will combine
the algorithm of the system with automatic-focus technology to implement the inside inspection based on the product inspective demands.