Abstract: A disc cartridge includes a first half, a second half, and a shutter member. The second half is connected to the first half. The second half is formed with a first aperture facing an optical head and a second aperture via which a disc rotational driving device is introduced. The shutter member is slidably mounted on the second half and has a first plate portion, at least one second plate portion and a connecting portion. The first plate portion opens or closes the first aperture and contacts the outer surface of the second half. At least one second plate portion extends parallel to the first plate portion for engaging with the inner surface of the second half. The connecting portion interconnects the first and second plate portions to complete the cross-sectional shape of a letter U of the shutter member. The length of the second plate portion is less than the length of the first plate portion.

Abstract: A case for a disc cartridge comprises a cover, and a case body having the cover rotatably attached thereto and having on its bottom wall integrally formed a plurality of resilient hold members for resiliently holding a disc cartridge.

Abstract: A hermetically sealed quartz crystal vibrator assembly having a flexible mounting plate for mounting a flexural mode quartz crystal vibrator adapted to vibrate in a first vibratory direction on a reference member. The mounting plate includes a first portion for supporting the vibrator and a second portion for coupling to the reference member. The mounting plate further includes a resilient portion between the first and second portions, the resilient portion being adapted to vibrate in the first vibratory direction and to further vibrate in a vibratory direction defining an angle of about 90.degree. with respect to the first vibratory direction. The resilient portion of the plate includes a stepwise bend to thereby define a gap between the vibrator and the resilient portion of the mounting plate overlapping the vibrator.

Abstract: An improved, compact, impact-resistant quartz crystal oscillator is provided for a timepiece. The oscillator comprises a substantially flat hermetically sealed envelope, a terminal tag provided with a contact pin fixedly mounted in the envelope, and a support therefor comprising a substantially annular support member provided with an annular rib on the periphery thereof defined between opposed elbows therein. One of the elbows provides a groove seat registered with the periphery of an aperture provided in the oscillator envelope. The other elbow provides a groove seat for a bifurcated crystal mounting plate support having elastic characteristics. The mounting plate is resilient in the vibrating direction of the crystal and perpendicularly thereto. Mounted in the oscillator envelope in substantial alignment with weighted tine ends of the crystal is a pair of opposed dampers which enhance the impact-resistance characteristics of the oscillator.