Abstract: According to this invention, level shift diodes and are connected between input nodes and output nodes through source follower MESFETs, and the output nodes are connected to a power supply through current source MESFETs and current supply resistors, thereby forming first and second level shift circuit units. A DC bias is applied to the gates of the current source MESFETs through resistors. At the same time, signals having phases opposite to input signals of the current source MESFETs are supplied to the current source MESFETs through capacitors, respectively. A current supply circuit has a gain in a high-frequency range.

Abstract: A high-speed semiconductor integrated circuit device has a main circuit section formed on a substrate, and a capacitance section formed on the substrate to surround the main circuit section. The capacitance section is made up of two conductive layers, an upper layer being insulatively disposed above a lower layer. These layers are applied with a power source voltage and a ground voltage, respectively. High-speed signal lines insulatively traverse the capacitance section and are connected to the main circuit section. The capacitance section is disconnected in the region where each signal transmission line passes, and defines a micro-strip type signal transmission line path structure. A "ladder"-shaped connection pattern is provided at each disconnected portion of the capacitance section, for electrically connecting a conductive layer arranged on one side of the disconnected portion to the corresponding layer arranged on the other side of the disconnected portion.

Abstract: A power source device including a lower voltage inverter transformer having plural secondary windings and a higher voltage inverter transformer having a primary winding connected directly to one of the secondary windings of the lower voltage inverter transformer without any rectifying circuit or inverter circuit interposed therebetween. The lower voltage and higher voltage transformers are contained in the same casing, the internal space of which is filled with an electrically insulative material to provide a unit device.

Abstract: There is disclosed a digital integrated circuit device which has high-speed transistors of a selected type. A timing controller is incorporated in this device and performs timing control for an internal digital circuit. The timing controller includes a series-circuit of two flip-flop circuits serving as a frequency-dividing circuit for frequency-dividing a reference clock signal and generating an internal timing signal, and a switch circuit connected to a signal feedback line of these flip-flop circuits. In a normal mode, the switch circuit supplies the internal timing signal output from the flip-flop circuits to the digital integrated circuit. At a desired timing, the switch circuit performs a switching operation in response to a control signal, electrically disconnects the signal feedback line of the flip-flop circuits, and alternatively supplies an external timing signal externally supplied thereto to the digital integrated circuit.

Abstract: There is disclosed a high-voltage power supply device capable of high precise control with a simplified circuitry and with a reduced energy loss in which a high-voltage transformer is controlled by switching means which is driven by a power source including a negative power supply and operated in response to pulse signals.

Abstract: A circuit board comprises a substrate made of a semi-insulating or insulating material, an insulating layer formed on the substrate and having a lower dielectric constant than the dielectric constant of the substrate, and a plurality of wiring conductors formed at predetermined intervals on the insulating layer. The insulating layer has a thickness determined according to the distance between adjacent wiring conductors and equal to 0.5 to 2.5 times the distance noted above, for the purpose of reducing cross-talk noise.

Abstract: The invention provides a novel pitch material useful as a base material of carbon fibers having excellent mechanical properties and characterized by a unique combination of several property parameters including the content of the optically anisotropic phase of at least 80%, a content of the pyridine-insoluble matter in the range from 30 to 70% by weight, a number average molecular weight in the range from 1000 to 1400 and a softening point in the range from 330.degree. to 380.degree. C. Such a pitch material is obtained from a starting pitch of a petroleum-based residual oil freed from light oily matter through a two-step heat treatment, of which the first step is performed at 400.degree. to 460.degree. C. under a pressure of 5 to 50 mmHg and the second step is performed at 450.degree. to 550.degree. C. for 0.2 to 30 minutes under a pressure of 0.1 to 5 mmHg. The advantages obtained by use of a film evaporator in the above mentioned heat treatment are described.

Abstract: A power supply device has improved power efficiency and stability for use in a copier or the like. The primary power supply to the device being switched with a constant turned-off period to achieve variable power supply control.

Abstract: There is disclosed an electrophotographic image forming apparatus in which toner loss by deposition to non-image area is prevented by detecting the surface status of photosensitive member and applying thus detected state to the image developing device.