Abstract: A rotating speed detecting apparatus has: a bearing sensor configured to detect rotation of a motor and output detection pulses whose frequency depending on a rotating speed of the motor; and a calculating unit configured to receive the detection pulses from the bearing sensor. The detection pulses include a first pulse and a second pulse output next to the first pulse. The calculating unit calculates a revolution of the motor from a pulse interval between the first pulse and the second pulse.

Abstract: There is provided an optical module for output light produced by diffracting incident light inputted from the outside, having an acoustooptic device for emitting the diffracted light produced by diffracting the incident light at a different outgoing angle corresponding to wavelength of the incident light and a first correcting prism for compensating first output light in which the difference of the outgoing angles corresponding to the wavelength in the diffraction efficiency is reduced.

Abstract: An optical coupler having a Y-branch operable to mix and output a first light and a second light from outside. The optical coupler includes: a first input optical wave guide operable to propagate the first light from outside; a second input optical wave guide operable to propagate the second light from outside; an optical coupler operable to output a mixed light, which is a mixture of the first light and the second light; and an output optical wave guide operable to propagate the mixed light and to output it from an end, wherein percentage per unit length of emitting light being propagated in the output optical wave guide to a periphery of the output optical wave guide is higher than that of the first input optical wave guide or the second input optical wave guide.

Abstract: A sampler module is disclosed for use in a sampling waveform measurement device that samples subject signals and measures the waveform of the signals. The module is constructed by accommodating within a metal container: a laser diode driver circuit that receives laser drive sampling pulse signals from the outside and supplies pulse drive signals by a gain switching method, a laser diode that receives the drive signals from the LD driver circuit and generates optical probe pulse light, a sampling photoconductor that performs switching in accordance with irradiated light pulses and samples the subject signals, a condenser that focuses optical probe pulse light from the laser diode upon the photoconductor, and cooling temperature control means that maintains the temperature of the laser diode at a fixed temperature.

Abstract: A short-width pulse generating apparatus for use in measurement of a reflection point, a sampling apparatus for use in measurement of a a reflection point, and a reflection point measuring apparatus each being able to specify a reflection position produced in an integrated high-frequency circuit or a reflection point produced in the inside of an optical element with high accuracy are provided. A short-width pulse generation apparatus comprises short-width optical pulse generating means for generating an optical probe pulse having a narrow pulse width and photoelectric conversion means for producing a short-width electric pulse on a signal transmission line when irradiated with an optical probe pulse, and a sampling apparatus comprises variable delay means for sequentially delaying an optical probe pulse and second photoelectric conversion means for sampling an electric potential on the signal transmission line by being irradiated with an optical probe pulse delayed by the variable delay means.

Abstract: Characteristics of a ferroelectric liquid crystal show that ionic impurities deteriorate its display quality to a great extent. The present invention provides a ferroelectric liquid crystal display device of good display quality without the deterioration of display characteristics, as a result of trapping the ionic impurities effectively by adding an organic material which traps ions and which lowers conductivity of a liquid crystal layer thereto.

Abstract: An optical pulse of a fixed width is applied to an optical fiber, back scattering light from the optical fiber is converted to an electric signal, which is converted to a digital signal by sampling with a fixed period. In a difference calculating section an average of digital signals at a first sample point and at W sample points preceding the first sample point is used as data at the first sample point, and an average of digital signals at a second sample point and at W sample points following the second sample point, which is after the first sample point by a number of sample points corresponding to the width of the optical pulse, is used as data at the second sample point. The difference between the data at the first sample point and the data at the second sample point is calculated for each of a series of sample points to obtain difference waveform data. Changing points of the difference waveform data are detected and a spliced point of the optical fiber is decided, based on the detected changing points.

Abstract: Polyphenyl-based liquid crystal compounds represented by the following general formula (1) and liquid crystal composition containing the same: ##STR1## wherein R.sup.1 represents a straight or branched C.sub.1-18 alkyl group, haloalkyl group, aralkyl group or haloaralkyl group with or without optically active carbon, R.sup.2 represents a straight or branched C.sub.1-6 alkyl group, haloalkyl group or aralkyl group with or without optically active carbon, W represents (1) --OCO-- or --COO--, in which case T represents a halogen atom or a methyl group, or (2) a single bond, --O-- or --OCOO--, in which case T represents a halogen atom, X represents --OCO--, --COO--, --C.dbd.C--, --CH.dbd.N--, --N.dbd.CH, Y represents single bond, --O--, --COO--, --OCO--, --CH.sub.2 --, --OCH.sub.2 --, --COOCH.sub.2 -- or --OCOCH.sub.2 --, Z.sub.1 and Z.sub.2 represents a hydrogen or halogen atom, a cyano group or nitro group, Z.sub.1 may be the same or different from Z.sub.

Abstract: An aligning agent for liquid crystals containing a polyamino acid having no optical activity.

Abstract: Polyphenyl-based liquid crystal compounds represented by the following general formula (1) and liquid crystal composition containing the same: ##STR1## wherein R.sup.1 represents a straight or branched C.sub.1-18 alkyl group, haloalkyl group, aralkyl group or haloaralkyl group with or without optically active carbon, R.sup.2 represents a straight or branched C.sub.1-6 alkyl group, haloalkyl group or aralkyl group with or without optically active carbon, W represents (1) --OCO-- or --COO--, in which case T represents a halogen atom or a methyl group, or (2) a single bond, --O-- or --OCOO--, in which case T represents a halogen atom, X represents --OCO--, --COO--, --C.dbd.C--, --CH.dbd.N--, --N.dbd.CH, Y represents single bond, --O--, --COO--, --OCO--, --CH.sub.2 --, --OCH.sub.2 --, --COOCH.sub.2 -- or --OCOCH.sub.2 --, Z.sub.1 and Z.sub.2 represent a hydrogen or halogen atom, a cyano group or nitro group, Z.sub.1 may be the same or different from Z.sub.

Abstract: A phenyl pyrimidine compound of this invention represented by the following formula (I) forms a smectic C phase and is useful for a constituent of a ferroelectric liquid crystal composition.R.sub.1 --Ph--Py--R.sub.2 (I)wherein Ph represents 1,4-phenylene group, Py represents 2,5-pyrimidine, R.sub.1 and R.sub.2 represent independently an acyloxy group or alkoxy group, either R.sub.1 or R.sub.2 represents a linear acyloxy group or a linear alkoxy group having more than seven carbon atoms. The compound of this invention has a properties of .circle.1 a low viscosity, .circle.2 of forming a smectic C phase (Sc), .circle.3 of being more than 70.degree. C. of an upper limit temperature of a Sc phase. By applying these properties it is able to give a good alignment effect of a composition comprising the compound using a conventional alignment effect of a TN type cell.

Abstract: Disclosed is an optically active cyclopropane compound represented by the formula (1): ##STR1## wherein R is an alkyl or cycloalkyl group, n is 0 or 1, Y.sup.4 is --CO.sub.2 CH.sub.2 --, --OCO-- or --OCH.sub.2 --, Y.sup.1, Y.sup.2 and Y.sup.3 independently represent --CO.sub.2 --, --OCO--, --O--, a direct bond or --CH.sub.2 O--, Z.sup.1, Z.sup.2, and Z.sup.3 independently represent ##STR2## A.sup.1, A.sup.2 and A.sup.3 independently represent fluorine, bromine, chlorine, a cyano group or hydrogen, and the mark ##STR3## indicates an asymmetric carbon atom. The optically active cyclopropane compound includes a compound which exhibits a ferroelectric liquid crystalline characteristic, and a compound which does not exhibit a ferroelectric liquid characteristic when used alone, but, can be used as a constituent of a ferroelectric liquid crystal composition.

Abstract: A phenyl-pyrimidine liquid crystal compound represented by the formula: ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and each represent an alkyl group having 1 to 18 carbon atoms, and X and Y each represent one of a single bond, --O--, --OCO--, --COO-- and --OCOO--, provided that one of X and Y is --OCOO--.

Abstract: A liquid crystal compound of the formula: ##STR1## wherein R.sup.1 and R.sup.2 represent C.sub.1-18 alkyl group, alkyl halide group or aralkyl halide, R.sup.1 may be the same as or different from R.sup.2, X is selected from --COOCH.sub.2 -- or --OCO--.

Abstract: A liquid crystal compound represented by the following general formula (1), which possess a large spontaneous polarization about room temperature and a liquid crystal composition containing a liquid crystal compound represented by the following general formula (1) ##STR1## wherein R.sup.1 represents C.sub.6-14 alkyl group, R.sup.2 represents straight or branched alkyl group with or without optically active carbon, X represents a group selected from --OCOO--, --O--, --COO--, --OCO-- or single bond, Y represents a group selected from --COOCH.sub.2 --, --OCO-- or --OCOO--, in which either X or Y is at least --OCOO-- group, m represents 0 or 1, Z represents a chlorine or bromine, a carbon atom marked with * represents optically active carbon atom.

Abstract: Polyphenyl-based liquid crystal compounds represented by the following general formula (1) and liquid crystal composition containing the same: ##STR1## wherein R.sup.1 represents a straight or branched C.sub.1-18 alkyl group, haloalkyl group, aralkyl group or haloaralkyl group with or without optically active carbon, R.sup.2 represents a straight or branched C.sub.1-6 alkyl group, haloalkyl group or aralkyl group with or without optically active carbon, W represents (1) --OCO-- or --COO--, in which case T represents a halogen atom or a methyl group, or (2) a single bond, --O-- or --OCOO--, in which case T represents a halogen atom, X represents --OCO--, --COO--, --C.tbd.C--, --CH.dbd.N--, --N.dbd.CH, Y represents single bond, --O--, --COO--, --OCO--, --CH.sub.2 --, --OCH.sub.2 --, --COOCH.sub.2 -- or --OCOCH.sub.2 --, Z.sub.1 and Z.sub.2 represent a hydrogen or halogen atom, a cyano group or nitro group, Z.sub.1 may be the same or different from Z.sub.

Abstract: A liquid crystal compound of the formula: ##STR1## wherein R.sup.1 and R.sup.2 represent C.sub.1-18 alkyl group, alkyl halide group or aralkyl halide, R.sup.1 may be the same as or different from R.sup.2, X is selected from --COOCH.sub.2 -- or --OCO--.

Abstract: A liquid crystal compound of the formula: ##STR1## wherein R.sup.1 is an alkyl group, X is chloro or bromo, and R.sup.2 is a branched-alkyl group; and the carbon atom marked with an * is an asymmetric carbon atom.