In an internal combustion engine, a fixed engine valve timing profile may be combined with a variable profile produced by a valve actuator coupled to one or more engine valves. A represents a divalent element, B represents a tetravalent element, \u03b3 satisfies 0. The contact plates have portions uncovered by the glue to provide extended areas for soldering to a motherboard. At least two openings partially overlapped and capable of communicating with each other are formed in the conductive layer, so that the conductive layer forms at least a pair of tip electrodes. The crystallite size of ITO in the transparent wiring layer 15 is 9 nm or less.