System for making a light beam scan a flat carrier with autofocusing
Реферат: ABSTRACT OF THE DISCLOSURE A light beam scanning system in which a light beam is provided with the automatic focus correction, which comprises a flat carrier having a reflective front surface and a antireflective or reflective rear surface sub-stantially parallel to the front surface, first and second lens assemblies positioned against the rear and front surfaces, respectively, an optical assembly provided for making a light beam path between the first and second lens as-semblies and a light source. A light beam emitted from the light source is guided to the rear surface of the carrier through the first lens assembly and reflected on the front surface after passing through the inside of the carrier or on the rear surface, then guided to the front surface from the outside through the first lens assembly, the path made between the first and second lens assemblies and the second lens assembly. The first and second lens assemblies are arranged so that their respective image magnifications satisfy a specific interrelation, thereby to establish the autofocusing of the light beam. BACKGROUND OF THE INVENTION Field of the Invention This invention relates generally to a system which makes n light beam scan a flat carrier for reading signals recorded thereon or recording signals thereon, and more particularly to such a system in which the scanning light beam keeps a predetermined focus condition on the carrier in spite of the deviation of the carrier from a predetermined position. Description of the Prior Art It has been proposed to record optically signals, for example, a video signal on a flat record carrier and/or read optically signals recorded on the flat record carrier with a light beam scanning the surface of the flat record carrier. In a system for such an optical recording and/or reading as
Catadioptric optical system, for optical reproducing head and optical-disk memory; optical disk
Номер патента: RU2169400C2. Автор: Йонг Хоон ЛИ,Чул Воо ЛИ,Чонг Сам ЧУНГ,Чеол Сунг ЙЕОН,Джоонг Еон СЕО,Йоунг Мин ЧЕОНГ,Донг-Хо СИН,Кун Хо ЧО,Пионг Йонг СЕОНГ,Джанг Хоон ЙОО. Владелец: САМСУНГ ЭЛЕКТРОНИКС КО., ЛТД.. Дата публикации: 2001-06-20.