Abstract: A condenser microphone in which a back electrode, disposed oppositely to the rear surface of a diaphragm, and a circuit assembling plate disposed oppositely to the rear surface of the back electrode, are held in a holder.Electronic circuit elements are attached to only one surface of the circuit assembling plate, and the other surface thereof is faced toward the rear surface of the back electrode with a predetermined distance provided therebetween. A back chamber, defined by a space between the back electrode and the circuit assembling plate, and enclosed by the holder improves the characteristics of microphone frequency response.

Abstract: For regulating the vibration frequency of a tuning-fork vibrator to a desired frequency, the tuning-fork vibrator is regulated so that its vibration frequency may become a frequency lower than the desired frequency by a predetermined value, and then the tuning-fork vibrator is regulated so that a difference between proper vibration frequencies of both legs of the vibrator may become smaller than a predetermined value, and further, the vibrator is regulated so that the desired frequency may be reached, while maintaining the difference in the proper vibration frequency smaller than the predetermined value. In this way, the desired frequency can rapidly be attained.

Abstract: A normally-closed switch in which a movable contact member is normally held in contact with a fixed contact member by spring-load of a plate spring member. When an operating member is pressingly operated, the plate spring member is resiliently displaced into a position where the plate spring member comes in contact with a stopper member. The movable contact member is thus separated from the fixed contact member. When the operating member is pressed further, the plate spring member is not displaced, but a resilient member is compressingly deformed, thereby compensating for the over-stroke of the operating member.

Abstract: A segment holder is mounted in a casing for rotational movement therein, and a plurality of contact wires extend substantially perpendicularly to the axis of rotation of the segment holder and are spaced from each other along the said axis of rotation, the segment holder being biased to turn in a direction under the resiliency of the contact wires. When a driver connected to the segment holder is actuated from the exterior of the casing, the segment holder is rotated against the biasing force applied thereto to make break electrical contact between the contact wires via a conductive segment(s) mounted on the segment holder.

Abstract: First and second color liquid crystal display elements of the negative guest-host type are disposed in adjacent and opposing relation to each other and the color liquid crystal display elements provide display in different colors, at least one of electrodes of each color liquid crystal display element having formed therein a display pattern. By the control of a changeover switch, an alternating drive voltage is applied from a drive circuit to one of the first and second color liquid crystal display elements to change the color of a background of the display in accordance with the control of the changeover switch.

Abstract: First and second fixed terminals are mounted in a casing and have one ends projecting out of the casing. Inside the casing, a bimetal extends between the first and second fixed terminals, the bimetal having one end secured to the first fixed terminal. The other end of the bimetal is held in engagement with one end of a coil spring disposed around a pivotable lever pivotably supported on the casing, the other end of the coil spring engaging the pivotable lever. When a current flowing through the bimetal exceeds a predetermined amount, the bimetal is bent to cause a contact supported on a distal end thereof to move rapidly out of contact with a contact supported on the second fixed terminal under the resiliency of the coil spring acting on the bimetal.

Abstract: On one end face of a case, a heating unit, a burner and a firing portion are aligned in this order, and a tubular windshield is mounted on the end face of the case to surround substantially entirely the burner. The windshield has formed therein an opening on the side of the heating unit, through which a lighter flame emitted from the burner is directed to the heating unit to set it alight when the case is turned down so that the heating unit lies above the burner.

Abstract: By applying an operating current to an operating coil, a moving iron core disposed in the operating coil is attracted deeply thereinto to butt against a fixed receiver. By applying a return current to a return coil, the moving iron core is pulled away from the fixed receiver. At least one of the moving iron core and the fixed receiver is divided into two parts in the direction of travel of the permanent magnet and a permanent magnet is sandwiched between the two parts to couple them together. The permanent magnet is magnetized by an operating magnetic field set up by the operating current and demagnetized by the return current.

Abstract: A high molecular film for polarization is disposed on an electrode plate with an intermediate high molecular film sandwiched therebetween to form a laminated member, the intermediate high molecular film having a lower melting point than the high molecular film for polarization. The laminated member is heated at a temperature in the vicinity of the melting point of the intermediate high molecular film to fusion-weld the high molecular film for polarization to the electrode plate through the intermediate high molecular film, and then the high molecular film for polarization is polarized.

Abstract: An electret diaphragm is housed in a case, a back electrode is disposed opposite the back of the electret diaphragm, a damper cloth is disposed in contact with the back of the back electrode, and a terminal plate is placed behind the damper cloth and connected with the back electrode. The back electrode, the damper cloth and the terminal plate are held by a tubular back electrode holder. The back of the back electrode holder is closed by a printed circuit board to define a rear compartment in the back electrode holder, and an impedance converter is disposed in the rear compartment. A sound hole is made for intercommunication of the rear compartment with the outside to achieve unidirectional directivity.

Abstract: An electret microphone in which an electret diaphragm, a back electrode plate disposed opposite thereto and a tubular back electrode holder for holding the back electrode plate are housed in a capsule, an impedance conversion element is housed in a hole made in the peripheral wall of the back electrode holder, and an input terminal of the impedance conversion element is connected to the back electrode plate and an output terminal is led out of the capsule through a notch formed in its peripheral wall.

Abstract: In a cathode ray tube socket, contacts to be respectively connected with terminal pins of a cathode ray tube are housed in a body, which has formed therein a chamber for a pair of electrode holders, the electrode holders being removably and adjustably supported in position within the chamber by cooperating projections and depressions, each electrode holder having fitted therein an electrode plate, and semispherical electrode portions projecting from the electrode plates are disposed adjacent each other to define therebetween a spark gap, one of the electrode plates being electrically connected with a contact for high voltage use.

Abstract: The present invention discloses a display device for a push button assembly having, within a push button provided in the front surface thereof with a window, shutters and a display plate of which display surface is faced to said window.Inserted into said push button is a support axially movable in a manner relative with the push button. The shutters are not pivoted to the push button, but pivoted to the support. The push button is provided with guide grooves for guiding the pivotal movement of the shutters. While being guided by the guide grooves and responsive to the axial relative movement of the support with the push button, the shutters are rotated between two positions, namely a first position where the display surface is screened from the window and a second position where the display surface is exposed to the window.