Abstract: An injection molding process for producing an integrally molded box-shaped plastic housing of a resin material. The housing includes integral portions of a bottom wall of a first thickness and an upright wall of a second thickness, the first thickness being in the range of from one-third to two-thirds of the second thickness and the bottom wall portion including at least one integral rib structure. A cavity is formed in a mold having cavity portions, respectively corresponding to the bottom and upright wall portions and the rib structure, in fluid communication. Fluid resin is injected through respective injection gates directly communicating with the rib structure cavity portion and the upright wall cavity portion, which provide passageways for flow of the liquid resin therethrough, thereby completely filling all cavity portions.

Abstract: A backlight having a reflection plate, a diffusion plate, a transparent light guide plate held between the diffusion plate and the reflection plate and having a reflection and diffusion surface adjacent to the reflection plate and a recessed light emitting surface adjacent to the diffusion plate, so that a space is defined between the recessed light emitting surface and the bottom surface of the diffusion plate adjacent thereto, a holder connected to the diffusion plate to define accommodation spaces between the opposite ends of the transparent light guide plate and the holder, and line light sources located in the accommodation spaces.

Abstract: A flexible magnetic diskette used for magnetically storing various information which is recorded and read by a magnetic head. The diskette includes a flexible plastic disk sheet uniformly coated with magnetic material and having a mount hole at its center, and a holder for securing the disk sheet over the periphery of the mount hole. The holder is also made of a plastic material for holding the flexible disk sheet over the peripheral portion of the mount hole via a double-sided adhesive ring. A core member is made of a magnetic metal having a high abrasive resistance and rigidly attached to the holder over at least a part of a surface of the holder, with which a drive unit is engaged.