Hitachi-Lg Data Storage, Inc.

Hitachi, Ltd.

Hitachi Consumer Electronics Co., Ltd.

Hitachi Video Engineering, Incorporated

Kouichi Ihara

Tatemi Ido

Akira Kitayama

Hiroharu Sakai

Nobuaki Sato

Kazuo Ikeda

Kenji Takahashi

Yuichi Yamada

There is provided an optical disc drive comprises an optical pick-up including a laser diode (LD) and a laser diode driver (LDD) for driving the laser diode, a digital signal processor (DSP) including a write strategy circuit and low voltage differential signaling (LVDS) drivers for transmitting a produced write strategy signal, a circuit board having the DSP mounted thereon and including a line for transmitting the write strategy signal, a transmission line connecting the circuit board and the LDD and transmitting a write strategy signal, and differential resistors connected between differential lines of outputs of the LVDS drivers. Especially, a resistor having a resistance value in a range of 80 to 500&#x3a9; is inserted between the differential lines of outputs of the LVDS driver inside the DSP.

Optical disc drive

An electronic device including a mechanism for changing the relative positions of two circuit boards such as in an optical disc drive is provided. A flexible printed circuit electrically connected between the two circuit boards changes shape to suppress fluctuations in the transmission characteristics occurring due to contact with metal such as a case, and provides stable signal transmission. The flexible printed circuit includes at least one or more differential lines, a fixed unit affixed to a case at least at one location, and a movable unit that changes shape according to the relative positions of two cases. The lines adjacent to the differential line are a grounded surface, and the flexible printed circuit is formed to narrow the distance between the movable unit lines more than the distance between the fixed unit lines.

Flexible printed circuit and electric apparatus and optical disc drive having flexible printed circuit

In a dust removing system, the level of influence of dust sticking to an objective lens of an optical head is detected from either an amount of light emitted from the optical head and reflected from an optical head or from an access time. Three stages of levels with regard to the degree of influence of the dust are set in accordance with such detection value, and a different message for the removal of dust is indicated on a display unit in response to the level of the influence. When the influence is low, a dust removing mechanism is automatically rendered operative to remove the dust. At the first level at which the influence of dust is low, the optical disk in the optical disk device is discharged and cleaning of the objective lens is performed, and an indication is provided on the display unit representing that cleaning is proceeding. When the second stage is detected, the optical disk in the optical disk device is discharged, and a message is indicated on the display unit representing that cleaning of the objective lens should be performed using a cleaning disk. When the third stage is detected, a message is indicated on the display unit representing that cleaning of the objective lens should be performed by manual operation.

Dust removing system for optical disk device

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Yokohama, Japan

Kouichi Ihara