Abstract: An inexpensive, high-performance, color vision correcting plastic eyeglass lens comprises a partial reflection film for partially reflecting light, or a coloring agent for partially absorbing light, or a combination thereof, so that an intended color vision rectifying spectral characteristic curve can be established in or imparted to the lens.

Abstract: A radio transceiver comprises an RF amplifier and a first frequency mixer which converts an amplified RF signal into a first IF signal and whose output may include intermodulation distortion. A second frequency mixer converts the output of first frequency mixer into a second IF signal. An interference detector detects the intermodulation distortion by seeing if a beat is included in the second IF signal. Upon detection of intermodulation distortion, a controller minimizes a gain of RF amplifier to decrease or eliminate the intermodulation distortion. Responsive to the end of conversation, the controller maximizes the gain of RF amplifier to increase the reception sensitivity. The controller may periodically maximize the RF amplifier gain after the detection of the intermodulation distortion. If no intermodulation distortion is detected during this gain-maximized period, the controller keeps the gain to be a maximized value.

Abstract: A battery charger for a portable wireless telephone set comprising a rapidly charging circuit for rapidly charging the battery by a first charging current of a high level at a start of the charging operation, a tricklingly charging circuit for tricklingly charging the battery by a second charging current of a considerably low level, and a charge controller for making the tricklingly charging circuit take over the rapidly charging circuit after a charge detecting circuit detects that the battery is rapidly charged to its normal voltage. In order to avoid that the battery is insufficiently charged by the tricklingly charging circuit when the telephone set is left in a power-on condition, the battery charger further comprises another charging circuit for supplying a third charging current which is lower thn the first charging current but higher than the second charging current.

Abstract: Electronic sunglasses of the transmittance-varying type including liquid crystal panels employing the electro-optical effect and a solar cell used as a power source. The electronic sunglasses include a voltage detecting circuit having such a hysteresis characteristic so as to output a signal for changing transmittance of the liquid crystal panel from a high mode to a low mode at at least high predetermined voltage or illumination, and changing transmittance from a low mode to a high mode at at least a low voltage or illumination. The sunglasses also include a first switch which operates at at least two switch positions, one switch position having a first stage of illumination at less than 20,000 Lux and a second stage of illumination at 20,000 Lux or greater at which transmittance is changed from a high mode and another switch position disabling the voltage detecting circuit.

Abstract: A distributed constant type delay line device comprises a first base body with a first cutout portion at a bottom corner thereof, a first delay path pattern provided on a first side of the first base body, a first ground conductor provided on a second side of the first base body, a second base body with a second cutout portion at a bottom corner thereof in correspondence to cutout portion of the first base body, a second delay path pattern provided on a first side of the second base body, a second ground conductor provided on a second side of the second base body, in which the second base body is combined with the first base body by contacting the second ground conductor to the first ground conductor such that the first cutout portion on the first base body exposes a part of the second ground conductor at another bottom corner of the second base body and that the second cutout portion exposes a part of the first ground conductor at another bottom corner of the first base body, a pair of input/output pins resp

Abstract: A battery-powered portable radio telephone for use in a mobile telephone network receives signals from the network and judges from the received signal whether the radio telephone is inside or outside of the service area of the network. A battery saver is provided to periodically interrupt the battery power of the telephone when the latter is judged as being outside of the service area.

Abstract: An intermediate frequency amplifier stage is disclosed, in which linearity of a signal strength detection output is improved. The intermediate frequency amplifier stage includes a plurality of intermediate frequency amplifiers, a plurality of double-wave rectifiers each coupled to the associated intermediate frequency amplifier and making full-wave rectification of the signal supplied from the associated intermediate frequency amplifier, and an adder circuit adding the rectification outputs of the respective double-wave rectifiers.

Abstract: A mechanical filter including at least two longitudinal mode vibrators, each of which is a piezoelectric ceramic member with constant modulus alloy members mounted separately on the top and bottom surfaces thereof. The two constant modulus alloy members have the same configuration, a frequency-temperature characteristic opposite to that of the piezoelectric ceramic member, and are aligned, at their individual centers, with the center of the piezoelectric ceramic member. The configurations of the two longitudinal mode vibrators can be predetermined to suppress higher order spurious vibration modes inside the mechanical filter itself.

Abstract: A ceramic resonator including an elongated piezoelectric ceramic platelet having an indentation formed in the center in the longitudinal direction, a polarization in the thickness direction where the polarization occurs at least in the indentation; first and second main surfaces; first and third metal thin film electrodes formed on said first main surface and second and fourth metal thin film electrodes formed on said second main surface, the third electrode being separated from the first electrode and the fourth electrode separated from the second electrode where the resonator has a constant vibration based on the dimensions of the region associated with the indentation the vibration being generated at the narrow part when an electrical signal is applied to the electrodes. Moreover, a ceramic filter consisting of plurality of the ceramic resonators connected in series can also be configured.

Abstract: A method for automatic frequency adjustment of mechanical resonators, in which plural target frequencies are specified spaced across the distribution curve of the initial resonance frequencies of the mechanical resonators; an output quota for finished resonators is specified at each target frequency; the initial resonance frequency of each resonator is measured, and the resonator is then transferred to an automatic trimming machine; and the adjusting frequency of the automatic trimming machine is reset, for that particular resonator, to the particular one of the target frequencies which is next higher than the initial resonance frequency of the mechanical resonator. However, if the output quota for that target frequency has already been filled, a still higher target frequency is specified instead. If the output quotas have been filled for all target frequencies within a permissible adjustment range, then the resonator is returned for coarse adjustment.

Abstract: A mechanical filter having at least a pair of mechanical vibrators which are arrayed approximately in parallel with each other in regard to their longitudinal axes, and two couplers which are coupled to the pair of mechanical vibrators. According to the mechanical filter one of the pair of mechanical vibrators undergoes the vibration of the order of an odd number and the other one undergoes the vibration of the order of an even number in the same vibration mode, or both of them undergo the vibration of the order of an odd number or even number in the same vibration mode. Furthermore, these mechanical vibrators have such a mechanical size that they will vibrate at their required order of vibration and at their respective resonance frequencies, and the two couplers are so constructed that they will be differentially coupled to the pair of mechanical vibrators approximately at right angles therewith.

Abstract: A flexural electromechanical transducer composed of a constant-modulus alloy material and a piezoelectric ceramic material having a high electromechanical coupling coefficient. In the transducer, the piezoelectric ceramic material is polarized in one direction and a specified frequency signal is applied to the piezoelectric ceramic material in a direction parallel to the residual polarization direction of the piezoelectric material for obtaining a thickness-shear vibration. The thickness-shear vibration of the piezoelectric material in turn causes the flexural vibration of the transducer. The transducer achieves a high quality factor Q, a low capacitance ratio r, good spurious characteristics, and low impedance.

Abstract: An electromechanical filter having minimum attenuation deviation in the pass band frequency range. The filter includes a plurality of mechanical resonators arranged substantially parallel to each other in one plane and mechanical couplers of longitudinal resonance characteristics which are disposed substantially transverse to the plurality of resonators for coupling the resonators together. The couplers have lengths which are between the first and second, and second and third oscillation modes of the longitudinal resonance characteristics. By virtue of the above structure, the couplers can be formed in a single mechanical coupling wire.

Abstract: A display device suitable for timepieces and the like includes a solid electrochromic material and a solid electrolyte. The device is free of liquid components and is substantially thinner than conventional display devices. The problem of leakage arising from the use of liquid electrochromic material or liquid electrolyte is avoided.