Abstract: A positive-type display device improved in response time and in uniformity of display images is provided. This display device has a cell structure containing a mixture consisting of at least one of nematic liquid crystals having a nematic dielectric anisotropy and at least one of pleochroic dyes in a closed thin space formed by two substrates which are parallel to each other and a spacer which is provided between ends of said two substrates. Each of said two substrates has an electrode film adherently attached to its surface within said closed space, and an alignment film is formed on at least one of said electrode films. The surfaces of said films which are brought into contact with said mixture are subjected to a treatment for orientation of the molecules of said liquid crystals and said dyes in a direction substantially normal to the plane of the substrate when a voltage is not applied.

Abstract: An electronic engraving system is provided wherein an object, e.g., a person, for a picture to be engraved on a card is picked up by a television camera and converted into corresponding electric signals; the electric signals are stored first and then read out at a lower scanning speed that suits a mechanical scanning system through scanning conversion means, and the picture of the object is engraved on the material in accordance with the read out signals, whereby the picture corresponding to the object can be easily engraved on the material, e.g., a plastic card without using any photographic original picture of the object.