Abstract: There is provided a plastics optical member having on its surface a light-diffusing layer composed of a layer of micro-joints formed by immersing a plastics material successively in a good solvent and a poor solvent, and a plastics light-quantity-controlling member having on its surface a white pattern composed of the micro-joints. The superiority in light diffuse reflection, transmission and light-quantity-controlling property permit their incorporation into various optical systems such as screens for projection, various displays, light-source-directly-under-an-illumination-surface type light boxes, edge light type light boxes, etc.

Abstract: A thin schaukasten which is composed of a diffusive transparent plate, a light homogenizing member, a fluorescent lamp and a reflection member and in which the light homogenizing member has a reflection pattern formed on a transparent support media to provide a distribution of transmission for preventing non-uniform luminous intensity on one surface of the diffusive transparent plate and the reflection member is disposed in such a manner as to reduce non-uniformity in luminous intensity on one surface of the light homogenizing member. A lighting circuit for the fluorescent lamp includes a frequency converter for preventing flicker when the fluorescent lamp is lit, and the lighting circuit is used in common to a plurality of fluorescent lamps.

Abstract: A contact exposure unit having a transparent contact surface and a liquid development unit having means for preventing leakage of a developer are, respectively, constructed as independent units. The exposure unit and the development unit are adapted to be releasably combined with each other thereby to form a portable copier. Outer housings of the exposure and the development units constitute in combination the housing of the portable copier.