Abstract: An improvement of a photographic film roll composed of a spool which has a spool core having a slit therein and a flange at both ends of the spool core and a photographic 120-size film which is placed and fixed on a continuous light-shielding backing paper in which one end of the backing paper is inserted into the slit of the spool and other portion of the backing paper is wound on the spool to form multiple convolutions, resides in that the backing paper has at the center in its longitudinal direction a width less than the distance between the two flanges measured at the position of ½ of height of the flanges and has two wide areas of at least 10 cm long one of which is within 50 cm area measured from its one end and another of which is within 50 cm area measured from its another end, the width of each wide area being larger than the distance between the two flanges measured at the tops of the flanges.

Abstract: A resilient, durable reel-locking member is provided in a magnetic tape cassette including a cassette case, a pair of reels rotatable in the cassette case to wind a magnetic tape, each of the reels including a flange and a plurality of teeth formed on a peripheral portion of the flange. The resilient, durable reel-locking member includes a slide body slidable between the reels in a front-rear direction of the cassette case, a pushing member pushing the slide body in the front-rear direction of the cassette case, a pair of cantilevered, arcuate expansions formed on opposite sides of the slide body, each of the expansions facing a respective adjacent one of the reels and extending in a direction normal to the front-rear direction of the cassette case, and a pair of claws, each of the claws projecting from a respective one of the expansions and being engagable with the teeth of the respective adjacent one of the reels.

Abstract: A magnetic tape cassette comprises an approximately rectangular bottom wall provided with an opening, into which a spindle is to be inserted, a side wall extending along the periphery of the bottom wall, and a structural part formed integrally with the bottom wall at a corner of the bottom wall and in proximity to the side wall. The magnetic tape cassette is of a thin-walled type, constituted of a resin, and integrally molded by feeding the resin from a position corresponding to the vicinity of a center point of the bottom wall into a mold. The bottom wall is provided with a flow path-like, thick-walled portion extending along a direction heading from the position in the bottom wall corresponding to the position, from which the resin is fed into the mold, approximately towards the structural part.

Abstract: A cassette for magnetic tape includes a pair of cassette halves cooperating with each other to form a cassette body; a pair of reels disposed rotatably in one of the cassette halves to wind the magnetic tape around the reels, each of the reels including a flange having a plurality of teeth formed at a circumference of the flange; and a reel locking assembly engaging the flanges for preventing rotation of the reels, the reel locking assembly includes: a slide body slidably disposed between the reels for sliding movement in a front-rear direction of the cassette body; an urging member urging the slide body towards a front of the cassette body; a pair of support members each disposed on a respective side of the slide body; and a pair of lock-engagement members, each having a central portion which is supported rotatably by a respective one of the support members, the lock-engagement members being made of a resilient spring wire rod.

Abstract: In a magnetic tape cassette including a cassette case, a pair of reels rotatable in the cassette case to wind a magnetic tape, each of the reels including a flange and a plurality of teeth formed at a peripheral portion of the flange., and a lock member engaging the flange for preventing the reels from rotating, the lock member further includes a slide body slidable between the reels in a front-rear direction of the cassette case, a pushing member pushing the slide body in the front-rear direction of the cassette case, a pair of expansions formed on opposite sides of the slide body facing the reels, each of the expansions expanding in a direction normal to the front-rear direction of the cassette case, and a pair of claws projecting from the respective expansions and being engagable to the teeth.

Abstract: A magnetic tape cassette comprises an approximately rectangular bottom wall provided with an opening, into which a spindle is to be inserted, a side wall extending along the periphery of the bottom wall, and a structural part formed integrally with the bottom wall at a corner of the bottom wall and in proximity to the side wall. The magnetic tape cassette is of a thin-walled type, constituted of a resin, and integrally molded by feeding the resin from a position corresponding to the vicinity of a center point of the bottom wall into a mold. The bottom wall is provided with a flow path-like, thick-walled portion extending along a direction heading from the position in the bottom wall corresponding to the position, from which the resin is fed into the mold, approximately towards the structural part.