A method, system, and one or more computer-readable storage media for depth acquisition from density modulated binary patterns are provided herein. The intake compressor is arranged in the intake passage. 2<fg2fw \u2003\u200326<\u03bd1\u2212\u03bd2<30 \u2003\u2003D1fw<0. The container support frame has an opening sized to receive a feed dispenser of the feed container when the feed container is positioned on the container support frame. The generating unit generates positional relationship information indicating the positional relationship between the first image and second image, based on the acquired data. Each contact has a contact portion forwardly extending into the receiving space and a connecting portion backwardly extending out of the body portion.