This invention in one aspect relates to a pixel structure. The distribution panel has terminals and is connected in series between the ignition coil and the spark plugs. A leakage barrier layer is formed on the first semiconductor layer. In order to provide compensation, the actual slope value m is multiplied by a compensation value. The width of the opening is wider than that of the locating slot, and the opening broadens as it nears the rear edge of the tray, allowing the locating cylinder to be easily received and guided into the locating slot. The device includes a stack of plates provided with central openings ; each chamber is formed by a central opening located between two parallel membranes while the humidity absorbing material is provided against each membrane ; each plate is sandwiched between two plates including a housing for the humidity absorbing material; and a plurality of chambers are stacked and connected in series.