Magneto-optical disk device

Abstract

Abstract PURPOSE:To reduce a stray capacity by putting the photodetectors and preamplifiers of a photoelectric converting part into the same package of the photodetectors. CONSTITUTION:The preamplifiers 251-254, a differential amplifier 26 and a cumulative amplifier 27 are formed as an IC (an area enclosed by a broken line) and put into a package 31 of 2-split photodetectors. The package 31 uses a case of a standard TO-18 or TO-5 and 2-split photodetectors 241 and 242 are set at the center of the case. Then a chip 32 containing those preamplifiers turned into an IC is set beside the photodetectors 241 an 242. In this example the 2-split photodetectors and the IC of preamplifiers are assembled. Otherwise it is also possible to form those 2-split photodetectors and preamplifiers on an Si substrate in a monolithic structure. Thus a satisfactory S/N is secured for a magneto-optical signal.

Inventors

• 👤 Toshimitsu Kaku
• 👤 敏光 賀来
• 👤 Masahiro Oshima
• 👤 尾島　正啓
• 👤 Yasushi Suketa
• 👤 裕史 助田

Bibliographic Details