摘要:
The invention comprises an optical pickup apparatus including a photodetector which detects a laser beam reflected from information tracks of a disk and an amplifier circuit which amplifies the outputs of the photodetector. The photodetector and the amplifier circuit are integrally combined. A preamplifier circuit is also provided for positional adjustments. A switch is included within the amplifier for alternately inhibiting the path of the outputs of the photodetector to the amplifier circuit to allow for positional adjustment with the preamplifier and enabling the path of the outputs of the photodetector to the amplifier circuit for normal operation.
摘要:
Two gaseous raw glass materials containing dopants to provide different refractive indices and borne by an argon carrier are jetted from the central or inner and first concentric nozzles 11, 12 of a five tip burner 1; an argon shield is supplied through the second concentric nozzle 13, and hydrogen and oxygen are supplied through the third and fourth concentric nozzles 14, 15, respectively. Soot-like glass particles 4 are formed by flame hydrolysis and deposited on the lower end of a start rod 3 which is gradually rotated and withdrawn to thus grow a cylindrical preform 2. The intermixing of the particles formed from the two glass materials produces a preform having a substantially parabolic radial index of refraction distribution, which characteristic is retained in an optical communication fiber formed by sintering and drawing the preform.
摘要:
To realize a system which can efficiently use a satellite communications or broadcasting channel and simply realize modes suitable for applications such as shopping, wherein the system also has a large-scale subscription. A system was configured wherein for information sent from a satellite the header of a packet is deemed as an information identifier based on the content of the information, or alternatively information having a receiving terminal identifier provided beforehand to the receiving terminal is combined with information having an information identifier based on the content of the information.