Yamaha Corporation

Masaki Dojun

Katsuichi Osakabe

Akira Usui

Yusuke Konagai

Tatsuo Fushiki

Takuya Tamaru

Kazuhiko Honda

Shinji Aoshima

Kentaro Nomoto

Hiromitsu Shibata

An optical disk recording apparatus operates on an optical disk having circular tracks which are provisionally written with an index signal used for securing a constant linear velocity of the optical disk from an innermost circular track to an outermost circular track, and records data along the circular tracks at different linear densities on different annular zones of the optical disk. In the apparatus, a disk drive section rotates the optical disk while synchronizing the index signal successively read from the rotated optical disk with a predetermined reference clock signal to thereby maintain the constant linear velocity of the circular tracks. A clock generating section multiples or divides the reference clock signal by different rates to generate different writing clock signals in correspondence to the different annular zones of the optical disk. A data recording section operates in synchronization to the different writing clock signals for recording data along the circular tracks at the different linear densities on the different annular zones.

Optical disk recorder for writing data with variable density

In an optical recording apparatus having an optical pickup, a rotating section is provided for rotating an optical disk which is formed thereon with a guide groove to define a spiral track having a plurality of rounds. The optical pickup has a light source for generating an optical beam and a diffractive grating for diffracting the optical beam to form a main beam and a pair of sub beams opposite with each other relative to the main beam. The optical pickup is operable for irradiating the main beam to the spiral track with accompanying the pair of the sub beams along apposite sides of the spiral track. A servo section operates the optical pickup to enable the main beam to trace the spiral track based on a tracking error signal derived from return lights of the sub beams reflected back from the optical disk. A recording section modulates the main beam for recording of information onto the spiral track while the optical dick is rotated. A control section controls recording of information each cycle the optical disk is rotated such that the recording of information is enabled to fill one round of the spiral track and disabled to blank another round of the spiral track so as to alternate the filled rounds and the blanked rounds.

Optical recording apparatus with interleaving blank rounds into spiral track

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Hamamatsu, Japan

Masaki Dojun