Provided a liquid crystal aligning agent capable of prevent liquid crystal molecules from polarization including a polyimide precursor, a cationic exchange resin and a solvent. The first hydraulic chamber is formed between a front cover and the piston, and the operating oil for actuating the piston is supplied thereto. In the electron-emitting device, a narrowest gap portion between the first carbon film and the second carbon film in the first gap is located above a surface of the substrate and the substrate has a depressed portion, at least, in the first gap. The tool uses frequency assignment techniques to perform the channel assignments in accordance with varying constraints and criteria. A lock holds the fanning tray in the pivoted up position.