Abstract: A pulse transformer includes a drum core having a winding core, a first flange provided at one end of the winding core in a first direction, and a second flange provided at the other end of the winding core in the first direction. First, second, third, and fourth terminal electrodes are provided in the first flange, and fifth, sixth, seventh, and eighth terminal electrodes are provided in the second flange. First, second, third, and fourth wires each have one end connected to a different one of the first to fourth terminal electrodes and the other end connected to a different one of the fifth to eighth terminal electrodes. A length of the drum core in the first direction and the second direction, perpendicular to the first direction, are substantially equal to one another, such that a planar shape of a mounting region of the pulse transformer is substantially square.

Abstract: An optical drive device generates a first push-pull signal and a first sum signal based on a light receiving amount in two light receiving areas of which each width in a signal light tangent direction is smaller than a diameter of a spot of signal light, generates a first normalized push-pull signal by normalizing the first push-pull signal by using the first sum signal, and generates a tracking error signal based on the first normalized push-pull signal.

Abstract: A method of producing a multilayer ceramic electronic device, having a firing step for firing a pre-firing element body wherein a plurality of dielectric layers and internal electrode layers containing a base metal are alternately arranged, characterized in that the firing step has a temperature raising step for raising a temperature to a firing temperature, and hydrogen is continued to be introduced from a point in time of the temperature raising step. According to the method, it is possible to provide a method of producing a multilayer ceramic electronic device, such as a multilayer ceramic capacitor, wherein shape anisotropy and other structural defaults are hard to occur and electric characteristics are improved while suppressing deterioration thereof even if dielectric layers becomes thinner and stacked more.