Liquid Lens Module with Wide Field-of-View and Variable Focal Length

Abstract

A novel wide angle and variable-focus imaging module based on a miniaturized liquid lens is presented for capsule endoscopy applications. For these applications, it is desirable to have features such as a wide field of view (FOV), variable focus, small size, and low power consumption, thereby taking full advantage of the miniaturized liquid lens. The proposed imaging module has three aspheric plastic lenses for a wide FOV, and one liquid lens that can change the focal length by as much as 24.5 cm with a bias voltage difference of 23 V-nns for variable focusing. The assembled lens module has an overall length of 8.4 mm and a FOV of 120.5 degrees. The realized imaging module including the proposed lenses is small enough to be inserted into a capsule endoscope, and it is expected to improve the diagnostic capability of capsule endoscopes.