Abstract: A diode is constituted by a quantum-wave interference layer with plural periods of a pair of a first layer W and a second layer B, having at least one quantum-wave interference layer in a p-layer or an n-layer. The second layer B has wider band gap than the first layer W. Each thickness of the first layer W and the second layer B is determined by multiplying by an odd number one fourth of quantum-wave wavelength of carriers in each of the first layer W and the second layer B existing around the lowest energy level of the second layer B. A &dgr; layer, for sharply varying an energy band, is formed at an every interface between the first layer W and the second layer B and has a thickness substantially thinner than the first layer W and the second layer B. The quantum-wave interference layer functions as a reflecting layer of carriers for higher reflectivity.

Abstract: A semiconductor device is constituted by a quantum-wave interference layer with plural periods of a pair of a first layer W and a second layer B. The second layer B has wider band gap than the first layer W. Each thickness of the first layer W and the second layer B is determined by multiplying by an odd number one fourth of wavelength of quantum-wave of carriers in each of the first layer W and the second layer B existing around the lowest energy level of the second layer B. A &dgr; layer, for sharply varying energy band, is formed at an every interface between the first layer W and the second layer B and has a thickness substantially thinner than the first layer W and the second layer B. The quantum-wave interference layer functions as a reflecting layer of carriers for higher reflectivity.

Abstract: A fuel supply apparatus having a cross sectional area S.sub.0 of a first low pressure fuel passage which is connected to a high pressure pump and which has a pressure regulator, a cross sectional area S.sub.1 of an orifice formed between the first low pressure fuel passage and a second low pressure fuel passage, and a cross sectional area S.sub.2 of the second low pressure fuel passage for supplying the low pressure fuel to the first low pressure fuel passage. Those cross sectional areas are set to satisfy a relationship of S.sub.1 <S.sub.0 <S.sub.2 such that the pressure pulsation generated at the pressure regulator is reduced, and the noise produced by the fuel supply apparatus is reduced.

Abstract: A semiconductor device, which has an oxide laver with the thickness thereof being varied from portion to portion of the inner surface of a trench and can be easily produced, and a process of producing the same. An n.sup.+ type single crystal SiC substrate is formed of SiC of hexagonal system having a carbon face with a (0001) face orientation as a surface, and an n type epitaxial layer and a p type epitaxial layer are successively laminated onto the substrate. An n.sup.+ source region is provided within the p type epitaxial layer, and the trench extends through the source region and the epitaxial layer into the semiconductor substrate. The side face of the trench is almost perpendicular to the surface of the epitaxial layer with the bottom face of the trench having a plane parallel to the surface of the epitaxial layer. The thickness of a gate oxide layer, formed by thermal oxidation, on the bottom face of the trench is larger than the thickness of the gate oxide layer on the side face of the trench.

Abstract: In order to provide an electric power steering apparatus which can be made compact as well as reduced in cost and can be improved in reliability, a control circuit and a drive circuit are provided on a deformable flexible circuit substrate. The circuit substrate is provided on the housing of a reduction gear mechanism while being deformed so as to cover a portion of the outer surface of the housing along the shape of the outer surface.

Abstract: Using a writing implement model defined in the O-XYZ coordinate system a character or graphic form is generated on a writing plane model (O-XY plane) defined in the O-XYZ coordinate system. A control polygon for a character or graphical form to be generated is designed in advance in the O-XYZ coordinate system and a smooth writing motion model is generated using local basis functions that are weighted by the coordinate values of the respective vertices of that control polygon. The position component of the writing motion model represents variations in the position of a representative point of the writing implement model in the O-XYZ coordinate system with respect to time, and the posture component of the writing motion model represents time-variations of its inclination in the O-XYZ coordinate system with respect to the O-XYZ coordinate system. The writing implement model and the writing plane model intersect at a time, thereby forming a character segment.

Abstract: A semiconductor laser having a plurality of semiconductor laser chips laminated by solder layers which cause no interference with laser beams is provided. To this end, each of the semiconductor laser chips has a solder sump recess formed in the surface to be soldered at an end adjacent to a laser beam radiating surface and extending through portions of the chip except an active layer.

Abstract: A high pressure fuel supply pump comprises a cylinder, the upper part of which is exposed to the outside of a head cover that is a part of the engine housing, and is fixed to the head cover by means of bolts, not shown. The remaining portion of the high pressure fuel supply pump is received in an accommodation hole of the head cover. A pump cam 111 is mounted to a valve camshaft for driving a suction/exhaust valve and drives the high pressure fuel supply pump. The use of an exclusive shaft for pump driving only, a bearing member therefor, and the like is rendered unnecessary, which enables a reduction in the number of parts employed. Further, since the timing with which the pressurized fuel is discharged is controlled through the operation of a solenoid valve, the precision with which fuel injection is controlled is improved.

Abstract: An apparatus and method for applying constant pressure to a plurality of pressure demanding mechanisms is disclosed. The apparatus includes a common rail, a plurality of pressure demanding mechanisms, a pressure supply source, and a plurality of branching paths. The lengths of the pressure supply path Lp, the pressure propagation path in the common rail, Lc, and the pressure branching paths, Li, are chosen so as to satisfy the following formulae, which leads to reductions in pressure fluctuations:(2n+0.5)Lp.ltoreq.Lc.ltoreq.(2n+1.5)Lp(2n+1.5)Lp.ltoreq.Li.ltoreq.(2n+2.5)Lp, where (n=0, 1, 2, . . .).

Abstract: A load current detection circuit restrains the generation of noise spikes with a minimum of circuitry when changing between current detection sensitivity ranges by providing a plurality of sensitivity resistors between the output of a voltage source, such as a negative feedback voltage amplifier, and a load. Sensitivity range changing is performed via switches that increase or decrease the number of sensitivity resistors between the voltage source and the load. When a current detection sensitivity change is commanded, a voltage difference across the sensitivity resistors is measured, and a control processor generates a control voltage for changing voltage difference gradually until the voltage difference is zero without changing the voltage across the load. The sensitivity range switching then occurs when no current flows through the sensitivity resistors so that no noise spikes are produced.

Abstract: A field-effect transistor includes a semi-insulating substrate, a semiconductor layer consisting of successive layers of GaAs compound semiconductor formed on the substrate, a gate electrode forming a Schottky contact with the semiconductor layer, and source and drain electrodes each forming an ohmic contact to the semiconductor layer. A semiconductor layer includes a buffer layer, an active layer, and a contact layer, where the impurity concentration in the contact layer is substantially equal to that in the active layer at the interface therewith. The impurity concentration in the contact layer increases continuously from the interface toward the upper surface of the contact layer. The field-effect transistor achieves a reduction in the ON resistance and an increase in the gate breakdown voltage at the same time, and to reduce power loss and increase efficiency.

Abstract: A robot control system includes: an end effector for acting upon an object to be worked; a manipulator mechanically supporting the end effector to apply predetermined movements to the end effector; a plurality of sensors mounted on the end effector to detect a position (x) of the end effector and a force (f) between the end effector and the object and to obtain an acceleration speed (x"), a speed (x') and a work rate (-x'f) of the end effector; a pre-controller for controlling movement of the end effector and the manipulator; a plurality of selection function units connected in parallel to the pre-controller and at least one of the selection function units being selected in accordance with the acceleration speed (x"), the speed (x') and the work rate (-x'f); and a plurality of control units each connected to a corresponding selecting function unit for inputting a target trajectory (x.sub.

Abstract: A fuel injection valve of a diesel engine, comprising a valve body including a concave conical surface in the tip portion of the valve body, and fuel injection holes extending from the concave surface to the outside of the valve body, and a needle valve movable in the valve body and including a cylindrical shaft portion, a first conical surface adjacent to the shaft portion and having a conical angle smaller than that of the concave surface, the lower edge of the first conical surface defining a contact line separably contacting with the concave surface, a second conical surface adjacent to the first surface and having a conical angle substantially equal to that of the concave surface, a third conical surface adjacent to the second surface and having a conical angle greater than that of the concave surface.

Abstract: A variable discharge high pressure pump for pumping a fuel into a common rail of a common rail type fuel injection system has a plunger reciprocable in a cylinder bore and a pumping chamber defined between and end face of the plunger and the inner peripheral surface of the cylinder bore. A solenoid valve has a valve member movable into an open position in which the valve member is moved out of engagement with an associated value seat into the pumping chamber when the solenoid valve is deenergized. When the solenoid valve is energized, the valve member is moved into a closed position in which the fuel pressure in the pumping chamber acts on the valve member to urge the same into engagement with the valve seat. The plunger is of a simple cylindrical structure free from any lead formed therein.

Abstract: A compound semiconductor device comprises a substrate formed from a single crystal of silicon, a layer of an insulator formed on a portion of a surface of the substrate, at least one layer of a high resistance compound semiconductor formed on the insulator layer, and at least one layer of a single crystal of a compound semiconductor formed on a different portion of the substrate surface from the insulator layer. The device can be manufactured by forming an insulator layer on one portion of a surface of a single crystal silicon substrate, and growing a compound semiconductor by epitaxy on the insulator layer and on the different portion from the insulator layer. One of useful applications is a hybrid semiconductor device having a compound semiconductor formed from e.g. GaAs on a silicon substrate.

Abstract: There is disclosed an electromechanical semiconductor transducer which is composed of a substrate of a first compound semiconductor and layers of second to fifth compound semiconductors grown on the substrate. The compound semiconductor contains at least one element such as aluminum, gallium, and arsenic selected from Groups III and V of the periodic table. The transducer converts mechanical strain into electrical signals.

Abstract: A color image reproduction apparatus includes a light source, a filter, a sensor means, an ink ribbon, a printer including a printer head and a printer drive, a feeder and a controller. The light source illuminates spots on the color original and light reflected therefrom is filtered by one of three aligned segments of the filter which are connected end-to-end in an alignment direction which three segments respectively filter different first, second and third portions of the visual spectrum. The sensor is disposed behind the filter and senses the light filtered by one of the three different filter segments when the one of the segments is disposed in front of sensor. The sensor outputs an intensity signal indicating the intensity of the sensed light. The ink ribbon is fixed in relation to the filter and has three different color ink layers which are attached to each other end-to-end in the same alignment direction as are the light filter segments.

Abstract: A semiconductor device having a superlattice structure, which comprises at least one unit structure including first and third semiconductor layers as quantum well layers, and a second semiconductor layer as a barrier layer, which are arranged alternately on each other is described. The first semiconductor layer has a higher impurity concentration than the third semiconductor layer and has a quantum energy level determined by its thickness. The third semiconductor layer is of a thickness having quantum energy levels, one of which is lower than that of the first semiconductor layer and the second of which is equal to or higher than that of the first semiconductor layer. The second semiconductor layer is of a thickness which allows electrons existing at the second quantum energy level of the third semiconductor layer to transfer easily from the third to the first semiconductor layer.

Abstract: An electronic print board comprising: a recording medium formed by a flexible sheet for recording erasable recordings and/or drawings or for holding a data sheet thereon, a mechanism for moving said recording medium, a scanning system for scanning the writings and/or drawings or data carried on a data sheet secured on the recording medium and providing electric signals corresponding to the writings and/or drawings or the data, operating unit including sheet size selecting switches, an image memory for storing data corresponding to the writings and/or drawings or the data carried on a data sheet secured on the recording medium. A control circuit for controlling the scanning operation of the scanning system, reading data from the image memory and printing the data on a printing sheet, and a reading and printing unit for reading data from the image memory and printing the data read from the image memory under the control of the control circuit.

Abstract: A robot control system includes: an end effector for acting upon an object to be worked; a manipulator mechanically supporting the end effector to apply predetermined movements to the end effector; a plurality of sensors mounted on the end effector to detect a position (x) of the end effector and a force (f) between the end effector and the object and to obtain an acceleration speed (x"), a speed (x') and a work rate (-x'f) of the end effector; a pre-controller for controlling movement of the end effector and the manipulator; a plurality of selection function units connected in parallel to the pre-controller and at least one of the selection function units being selected in accordance with the acceleration speed (x"), the speed (x') and the work rate (-x'f); and a plurality of control units each connected to a corresponding selecting function unit for inputting a target trajectory (x.sub.