Abstract: Coil springs 96 and 97 are incorporated in a driving-side transmission mechanism 61 so as to absorb backlashes between a rack 55 and a drive gear 59a. Since the respective backlashes between the drive gear 59a and the rack 55 are absorbed by way of the coil springs 96 and 97, phase matching at the sole driving-side transmission mechanism 61 is required as phase matching work of toothed portions of gears during assembly, thereby simplifying the assembling task and shortening the amount of assembling hours. Additionally, since a coil spring is not included in the rack 55, the rack can be designed to be small-sized in its width direction, thereby minimizing the moment of a force about the meshed engagement point, acting on an optical head carriage 53, and reducing transfer loss in the head.

Abstract: Coil springs 96 and 97 are incorporated in a driving-side transmission mechanism 61 so as to absorb backlashes between a rack 55 and a drive gear 59a. Since the respective backlashes between the drive gear 59a and the rack 55 are absorbed by way of the coil springs 96 and 97, merely phase matching at the sole driving-side transmission mechanism 61 is required as phase matching work of toothed portions of gears during assembly, thereby simplifying the assembling task and shortening assembly time. Additionally, since a coil spring is not included in the rack 55, the rack can be designed to be small-sized in its width direction, thereby minimizing the moment of a force about the meshed engagement point, acting on an optical head carriage 53, and reducing transfer loss in the head.

Abstract: A high frequency oscillation type proximity switch, comprising: an oscillation circuit having a first resonant frequency; a tank circuit connected in a positive feedback path of the oscillation circuit and including an LC resonant circuit having a second resonant frequency slightly different from the first resonant frequency; and a comparator circuit which discriminates the amplitude of an oscillation output of the oscillating circuit at a predetermined threshold level; the comparator producing a detection output signal when a nonmagnetic metallic object is brought to a certain proximity of a coil included in the LC resonant circuit and a level of the oscillation has thereby changed by a certain amount as a result of a change in the susceptance of the coil.

Abstract: In a mode-change mechanism for a tape recorder, a driving bar is mounted for movement between a record/playback mode position and a stop mode position, a partially toothless gear has a cam thereon engageable by a cam follower on the driving bar for moving the latter between its mode selecting positions in response to turning of the partially toothless gear between immobile positions thereof in which opposed first and second toothless portions on the outer periphery respectively face a driving gear for intermittently rotating the partially toothless gear, a lock lever is selectively engageable with one of a pair of stop elements on the partially toothless gear for halting rotation of the latter in a respective one of the immobile positions thereof, and a spring urges the driving bar toward one of its mode selecting positions, with the cam, toothless portions and stop elements on the partially toothless gear being angularly positioned in respect to each other so that, when the lock lever is disengaged from one