Vari-focal Light Field Camera for extended depth of field

Abstract

In recent years, as interest and demand for the metaverse and self-driving cars such as AR/VR have grown rapidly, great efforts have been made around the world to practicalize 3D depth sensing cameras. The light field camera, one of the three-dimensional depth-sensing cameras, is a camera that can detect depth with only one image sensor and is the most popular technology in practical aspects such as volume, cost, and battery consumption. Light field cameras can extract depth information from images such as those measured by multiple cameras, as microlens arrays act as key optical components for conventional cameras. In the existing light field camera, research on increasing the measurement range, angle of view, and depth resolution in the depth extraction area in the image processing area has been actively conducted. However, research in the hardware area of light field cameras was insufficient. Therefore, in this paper, we propose a study on the hardware implementation and characteristics of light field cameras. First, we propose an efficient processing method for microlens arrays, which are key components of light field cameras. Second, we devised a method of applying a variable-focus lens to widen the measurement distance of the light field camera. Third, we present a method for optimizing the light alignment of the microlens array to broaden the angle of view of the light field camera. Finally, we present a miniaturization method to apply light field cameras to mobile applications. Successful experimental demonstrations represent significant advances in the field of light field camera technology.