A displacement detecting device includes a light source, a beam splitting section, a diffraction grating, a reflecting section, a beam combining section, a light receiving section, and a relative position information output section. The VQ operates by quantizing channel state information by reference to both the current channel state information and a prior channel state quantization. The road navigation data may include information related to the form of the road and a reliability rate. The pyrimidopyrimidine derivatives may be spin-coated at room, or ambient, temperature when applied to the fabrication of an electronic device, for example, organic thin film transistors.