A printhead is disclosed, which can speed up transfer of image data and driving of printing elements without increasing the number of signal lines and connection terminals. Methods for making and using the gas sensor with a selective reference electrode comprising an inhibitor are also disclosed. The stacked capacitors are formed with the lower electrodes within the opening by depositing a capacitor dielectric and an upper electrode within the opening. The light reflected by the reflecting member is radiated into the optical waveguide and conducted thereby to the color separator. In this way rods can be fixed in the clamps and relative to the device.