Abstract: An Insulated Gate Bipolar Transistor (IGBT) having a new structure capable of performing a low on-voltage and a high-speed turn-off is provided. A P-type collector region 1 of IGBT is not formed on the entire reverse surface of an N-type base region 2, but formed only on its part, and a metal collector electrode 9 is electrically connected only with the surface to which the P-type collector region 1 exposes. An area of a diffusion window in a collector region is relatively reduced, whereby the impurity concentration of the entire collector region is set at a lower value and hole injection efficiency is decreased. At the same time it is possible to obtain high surface concentration with deep diffusion depth of the collector region required to form a favorable ohmic contact.

Abstract: A conductivity modulation type field effect transistor comprises an n.sup.- type low concentration impurity layer of high resistance formed on an n.sup.+ type silicon substrate, a first channel region of a given width formed on the low concentration impurity layer, a pair of p type gates oppositely formed with the first channel region therebetween, an n.sup.- type low concentration impurity layer formed on the first channel region including the p.sup.+ gate, a p channel layer including two channel regions formed on the n.sup.- type low concentration impurity layer, and a pair of n.sup.+ type sources formed on the second channel region with their center aligned with a center of the first gate means, in which, after the formation of the n.sup.

Abstract: A semiconductor device for accomplishing high speed switchings with a large current includes a radiation plate, a first conductor fixed on said radiation plate, a first insulating layer fixed on said first conductor, a second conductor fixed on said first insulating layer, at least one semiconductor element and a second insulating layer fixed on said second conductor, a third conductor fixed on said second insulating layer, a fourth conductor for electrically connecting the surface electrode of said semiconductor element with said third conductor, a first power terminal fixed on said second conductor, and a second power terminal fixed on said third conductor. To reduce the internal inductance, said first and second power terminals have a flat part whose width is larger in length than the height. Also, these terminals are adjacently arranged substantially parallel to each other.

Abstract: A porous water-treating material comprising cut porous strands each comprising a resinous matrix material which consists essentially of a thermoplastic polymer material or a mixture thereof with an inorganic particulate material. Each strand having a number of pores connected to each other and an irregularly rugged peripheral surface which has a ratio in diameter of a circumscribed circle to an inscribed circle in any cross-sectional profile from 1.10:1 to 5.00:1 and a ratio of the distance between circumscribed lines to that between inscribed lines in any side projection profile of from 1.10:1 to 3.00:1. The cut porous strands are prepared by melt-extruding a resinous mixture of the resinous matrix material with a blowing agent at a temperature higher than the melting point of the thermoplastic polymer material and the thermally decomposing point of the blowing material so as to cause the strands to have a number of pores and an irregularly rugged peripheral surface thereof.

Abstract: This invention provides an aerator comprising a jet stream generator for ejecting a gas and a liquid in a mixed state from a nozzle, and a tubular flow straightener for mixing the bubble-containing stream ejected from the nozzle with ambient water and discharging the resulting mixture from the discharge orifice thereof, characterized in that the flow straightener has a tubular form whose internal diameter is reduced from the inlet toward the discharge orifice through at least a part of its length.This aerator can produce a stream containing minute gas bubbles, even when a gas is supplied thereto in such a large amount as to give a gas-to-liquid volume ratio of 3/1.

Abstract: An apparatus for ejecting droplets of ink including: a passage for ink; an orifice disposed at one end of the passage; a pressure-applying device for applying a pressure wave to the ink within the passage; and a signal-supplying device for supplying an actuating signal to the pressure-applying device. The frequency of the signal is such that the displacement of the ink surface at the orifice due to the pressure wave is maximized.

Abstract: An ink jet printing head which includes a head body provided with an ink filling port (18), a plurality of rows of nozzles (32A.sub.1 through 32A.sub.5, 40B.sub.1 through 40B.sub.5) arrayed in a staggered formation, pressure chambers (21A.sub.1, 21A.sub.2, . . . , 21B.sub.1, 21B.sub.2, . . . ), one for each of the nozzles, and ink passages (28A.sub.1, . . . , 33A.sub.1, . . . , 38B.sub.1, . . . , 41B.sub.1, . . . ) connecting the ink filling port with the nozzles via corresponding pressure chambers. (19A.sub.1 through 19A.sub.5, 19B.sub.1 though 19B.sub.5). The pressure chambers are formed inside the head body and adjacent to the surface of at least one side of the head body. Piezoelectric elements are mounted on the outside of the head body at positions corresponding to the pressure chambers.

Abstract: A method for driving an ink jet printer which includes an electro-mechanical transducer which is operated by electrical pulses to eject ink from an ink nozzle connected to pressure chamber wherein two successive electrical pulses are supplied to the transducer before the ejected ink is separated from the remaining ink in the pressure chamber.

Abstract: A timing pulse generator for producing timing pulses the period of which is variable. In the timing pulse generator, a plurality of reference pulse trains are produced which have the same frequency as each other, but different phases from each other. Then, each of the pulses comprising the final timing pulses to be produced is created by suitably selecting one of the pulses from among the reference pulse trains, sequentially.

Abstract: First and second optical latent image forming devices form an electrostatic latent image directly on a homogeneously charged recording medium surface. Each of the first and second optical latent image forming devices has the capability of discharging almost half the initial charges of the recording medium. The discharging effect of the first and second optical latent image forming devices forms the combined electrostatic latent image.

Abstract: A non-impact printer comprising: a light source; a light modulator; a light modulation controller including a print timing control pulse generator; a light beam reflector made of a polygonal mirror; and a photoconductor drum upon which a modulated light beam scans an area used for scanning, wherein the print timing control pulse generator further includes a compensating means basically comprised of a means for measuring the respective scanning times required for scanning the respective lines to be scanned on the area used for scanning and a means for adjusting the periods of the print timing control pulses in accordance with each scanning time, thereby the same number of print timing control pulses can always be produced for every line to be scanned on the area used for scanning.

Abstract: An inexpensive laminated safety glass excelling in resistance to penetration as well as in its low temperature properties, which is hardly discolored with the passage of time, which comprises a laminated assembly of at least two sheets of glass between which is interposed a layer of a polyurethane elastomer, said sheets and said layer being firmly bonded together, said layer of polyurethane elastomer being obtained by curing, in the presence of curing agent, a polyurethane prepolymer having --NCO group at its both ends produced by reacting a diisocyanate with a polyester having --OH group at its both ends which has been obtained by reacting the dicarboxylic acids and their acid anhydrides with at least one kind of glycol, and the process for producing the same.

Abstract: A method of producing a non-combustible light-weight shaped article, which comprises shaping a mixture comprising (a) powders of silicon or a silicon alloy, (b) inorganic powders having a porous or hollow structure and (c) water glass, and maintaining the resulting shaped article at a temperature of 15.degree. to 120.degree.C. thereby to foam and cure it.