Compound-Eye Camera Module as Small as 8.5 $\times$ 8.5 $\times$ 6.0 mm for 26 k-Resolution Depth

To promote the widespread use of light-field computational cameras, downsizing of the system is essential. This paper presents an 8.5 mm × 8.5 mm × 6.0 mm tiny compound-eye camera module based on the light field. The camera module is composed of a single-lens unit of a 63° field-of-view (FOV) diagonal, a microlens array (MLA) glued on an 8-Mpix color CMOS sensor (1/3.2” format), and a read-out substrate. The captured raw MLA image is capable of constructing a 26 000-resolution depth image and refocused 2-Mpix 2D RGB images. We also demonstrated that our “image height calibration” and “optical scoring” improved the accuracy of the measured depth and revealed it to be effective for wide-angle FOV optics, such as the lens unit used in our tiny camera module that has the potential for widespread application. Analysis of the depth accuracy proved that the measured depth accuracy with our camera was higher than 90% in the depth range from 5 to 50 cm at the image center.