Abstract: An efficient brightness controller is disclosed, which can be applied to various discharge tubes different in length, diameters and/or the like. The controller includes a high frequency transformer 2 having a primary coil. First terminal (node N.sub.2) of the primary coil is connected to a power supply V.sub.DD1, and second terminal (node N.sub.1) is connected to an output element 3. The controller also includes an amplifying circuit 6 for amplifying the waveform of the voltage at the node N.sub.2. The controller further includes an ON-time/OFF-time control circuit 5 for setting the optimum ON time depending on the output voltage at the node N.sub.1 and the output from the amplifier 6, and then adjusting the OFF time on the basis of the set optimum ON time.

Abstract: A disk substrate molding die is provided in which the quantity of eccentricity of a stamper can be reduced to a small value. The molding die includes a member having mounted thereon a thin plate (19) carrying thereon a recorded transfer signal and an adjusting device consisting of a plurality of pairs of adjusting blocks, each formed of movable blocks (9a) and (9b) and blocks (10a) and (10b) having adjacent surfaces inclined in the moving direction of the movable blocks and common to one another.