Provided is an imaging lens, including, in an ordered way from an object side, a first lens having positive refractive power, a second lens having negative refractive power and having a meniscus shape concavely formed at an object side surface, and a third lens having positive refractive power and having an aspheric shape. In some embodiments, a first integrated circuit provides a clock signal and a data signal to a second IC, wherein the data bits of the data signal are timed according to the clock signal, and wherein the frequency of the clock signal is capable of being changed even when the data signal is valid. Each of the electrodes comprises a current collector and a layer of active material mixture disposed on both surfaces of the current collector, and the polymer is capable of absorbing and retaining nonaqueous electrolyte.