公开(公告)号：EP0936603A3

公开(公告)日：1999-10-06

申请号：EP99301040.4

申请日：1999-02-12

申请人： Hitachi, Ltd.

发明人： Shimano, Takeshi ,  Nakamura, Shigeru ,  Ohnishi, Kunikazu ,  Inoue, Masayuki ,  Fukui, Yukio

IPC分类号： G11B7/12

CPC分类号： G11B7/1353 ,  G11B7/00718 ,  G11B7/0903 ,  G11B7/0909 ,  G11B7/094 ,  G11B7/0941 ,  G11B7/0943 ,  G11B7/131 ,  G11B7/1367 ,  G11B7/1381 ,  G11B2007/0006

摘要： An optical head eliminates an disturbance which occurs in a focus error signal in association with the decentering of an optical disk (107) when an optical spot crosses a track on a storage film surface, and in addition the optical head cancels an off-set which occurs in a tracking error signal in association with the movement of an objective lens (106). In the constitution of the optical head, phases of wave surfaces of ±1st order diffracted lights are shifted by an amount of λ/2 with a common period by using a phase-inverted diffraction grating (701) the phase of which is inverted with a period of Dλ/(2P · NA) in a radial direction of the optical disk (107), thus causing, on the optical disk (107), sub-spots (109, 110) to be located on the same track as a main-spot (108). Taking advantage of this location, focal point shift error signals of the main-spot 108 and the sub-spots (109, 110) are added to each other with an appropriate gain ratio, thereby making it possible to cancel the disturbance which occurs in the focus error signal. Meanwhile, tracking error signals of the main-spot (108) and the sub-spots (109, 110) according to a push-pull method are subtracted from each other with an appropriate gain ratio, thereby making it possible to cancel the off-set.

公开(公告)号：EP0820043A2

公开(公告)日：1998-01-21

申请号：EP97305379.6

申请日：1997-07-18

申请人： HITACHI, LTD. ,  Hitachi Video & Information System, Inc.

发明人： Takami, Yutaka ,  Matsumoto, Kenji ,  Itoh, Shigeyuki ,  Inoue, Masayuki

IPC分类号： G07F7/08 ,  G06F17/60 ,  G07F19/00

CPC分类号： G07F7/0866 ,  G06Q20/06 ,  G06Q20/10 ,  G06Q20/363 ,  G06Q40/02

摘要： A processor 29 automatically sets a direction of transferring electronic money information depending on the existence of IC cards 1a, 1b connected to IC card connecting portions 11a, 11b, and the existence of an external device connected to an external device connecting terminal 8, thus making instructing operations for transferring electronic money information easier.

摘要翻译： 处理器29根据连接到IC卡连接部分11a，11b的IC卡1a，1b的存在以及连接到外部设备连接端子8的外部设备的存在自动设置传送电子货币信息的方向，从而使 指示操作更容易转移电子货币信息。

公开(公告)号：EP0233984A1

公开(公告)日：1987-09-02

申请号：EP86109515.6

申请日：1986-07-11

申请人： HITACHI, LTD.

发明人： Ishigaki, Masaji ,  Onuki, Hideo ,  Fukui, Yukio ,  Inoue, Masayuki ,  Ohnishi, Kunikazu

IPC分类号： G11B7/013 ,  G11B7/007 ,  G11B7/00

CPC分类号： G11B7/24085 ,  G11B7/004

摘要： A digital information recording and reproducing method for significantly improving the transfer rate of digital information, comprises the steps of: forming a plurality of light beam guide trucks on a recording medium (3) capable of multiple light-wavelength recording, the trucks being spaced apart by a predetermined pitch (P) and each of the trucks comprising a series of pre-pits (1) disposed in a scan direction (A) and spaced apart by a pitch (W) longer than the diameter of a spot (2) of a light beam (14) for use in recording and reproducing; and recording and reproducing an information bit (21) by changing the light beam (14) to have a different wavelength predetermined n times in a predetermined order while the light beam (14) is scanned by one pitch (W) between the pre-pits (1).