Abstract: A process for producing a wide range of shades in images that are presented in successive frames on image fields on opto-electronic display means having at least one illumination element at each of a plurality of pixel locations. Each pixel location, for example, may have a red, a green and a blue illumination element. The display is divided into uniformly-sized display neighborhoods.

Abstract: An adaptive dithering apparatus analyzes an input video signal as a function of available primary shades and produces a select signal whose value is a function of the desired shade represented by the input video signal and of the available primary shades. A combiner combines the input video signal with a selected one of a plurality of dither signals to generate a dithered input video signal. The one dither signal is selected under the control of the select signal. Finally, an adjustor receives the dithered input video signal, the available shade signal, and the select signal and, under the control of the select signal, adjusts the dithered input video signal to have a value equal to one of the available primary shades. Thus, an input video signal may be dithered with a dither signal that is optimized for dithering an input signal that falls into a particular range of desired shades. That is, a different dither signal may be employed for each possible spacing of adjacent available primary shades.

Abstract: A portable electronic apparatus includes a box type housing made of synthetic resin and having a top wall in which an opening is formed. The housing houses a heat radiating circuit component therein which faces the opening of the top wall of the housing. A keyboard device is provided at the housing in such a manner as to close the opening of the top wall. The keyboard device has a bottom surface, covered by a metal plate, which faces the circuit component. A heat sink is provided between the circuit component and the metal plate. A metal shield is provided between the metal plate and the heat sink. The heat sink includes a bag formed of a flexible film and a liquid refrigerant with which the bag is filled. The bag is in contact with both the circuit component and the metal shield, and can thus absorb heat from the circuit component and transmit the heat to the metal plate.

Abstract: An optical head applies a laser beam to a region of the magnetooptical disc, and a magnetic head applies a magnetic field to the region of the magnetooptical disc while the laser beam is being applied thereto, thereby to record information in the region. The optical and magnetic heads are interconnected by a link mechanism so that they are movable in unison with each other radially with respect to the magnetooptical disc. An electromagnetic shield is disposed around the magnetic head for blocking magnetic and electric fields parallel to the magnetooptical disc.