Methods, systems, and computer program products are disclosed for classifying nodes into broadcast tiers to reduce traffic in decentralized networks. After AD conversion of an analog color video signal from an imaging element, a difference between codes of adjacent pixels is obtained in regard to the same color, and an output code of this difference is converted into a code with less change-over bits between the adjacent codes. Then, the control section allows a liquid crystal display device to display error information in which a first image of character information is combined with a second image of an error occurrence site in the drive mechanism. A response light received from the substrate and the feature is measured to obtain a response spectrum of the response light. The distance between the respective mounting portions of the two such contacts may be defined independently of the contact pitch. The liquid housing container recycling method includes forming a detour flow path in the liquid housing body such that the liquid inside the liquid housing unit flows to the supply port without passing through the filter in the detour flow path, and injecting the liquid inside the liquid housing unit.