Yamaha Corporation

Takashi Nagano

Morito Morishima

Katsuichi Osakabe

Koji Suzuki

Tamon Kondo

In an apparatus for recording a broadcast program on an optical disk, a broadcast reception section receives a broadcast signal containing various programs broadcasted from a broadcast station. A recording setup section specifies a program to be recorded on an optical disk among the various programs contained in the received broadcast signal. An information acquisition section acquires attribute information associative of content of the specified program from an electronic program guide of various programs. A recording/reproducing section is operated to record the content of the specified program by forming a pattern of marks and spaces on a data recording face of the optical disk with an optical process of irradiating an optical beam onto the data recording face, and is also operated to form a visible image of the attribute information of the recorded content with the optical process on other area of the data recording face than the area where the content is recorded or on a label face reverse to the data recording face of the optical disk.

Optical disk apparatus capable of recording broadcast program with visible symbol

A strategy process used for recording data on an optical disk is also used during DC erase is performed. Effects similar to those obtained in the case, in which a high frequency signal is superposed on a laser diode output current during the DC erase, can be obtained by performing the strategy process on the laser diode output current during the DC erase. This eliminates the necessity for generating high-level and high-frequency signals. Consequently, an apparatus can be constructed at low cost.

Laser driving apparatus

In an optical recording apparatus, a detecting section detects disk identification information of an optical disk for selecting a constant which relates to the detected disk identification information. A test OPC section performs test writing operation for OPC at a predetermined linear velocity prior to recording of data so as to obtain a test value. A formulating section formulates an equation expressing a target value in function of a recording linear velocity based on the constant, the predetermined linear velocity and the test value. A running OPC section performs running operation of OPC by monitoring an actual value while irradiating a laser beam for the recording of data at the recording linear velocity. A controlling section controls the power of the laser beam such that the monitored actual value coincides with the target value which is determined by the equation with respect to the recording linear velocity.

Optical disk apparatus of variable recording velocity with optimum power control

A method is designed for recording information on an optical disk in the form of a sequence of pits along a track of the optical disk. The method is carried out by the steps of generating a main optical beam and a sub optical beam while modulating a power of the main optical beam and the sub optical beam according to a recording signal representative of the information, the main optical beam having a power sufficient to form the pit, the sub optical beam having a power insufficient to form the pit, irradiating the main optical beam along the track to form the sequence of pits, irradiating the sub optical beam onto a vicinity area which is not irradiated by the main optical beam but which is adjacent to an area irradiated by the main optical beam, detecting a first return signal level of the sub optical beam reflected back from the vicinity area at a timing when the pit is formed by the main optical beam, detecting a second return signal level of the sub optical beam reflected back from the vicinity area at another timing when the pit is not formed, and controlling the power of the main optical beam in a real time basis during the recording of information based on both of the first return signal level and the second return signal level of the sub optical beam.

Method of controlling laser power of main beam by monitoring sub beam

An opical disc recording method, comprises the steps of: a) forming a record signal in accordance with input information; b) generating a recording laser beam modulated with the record signal; c) controlling a laser radiation time at a record power for a 16&#xd7; or higher write-speed to be (n+K)T for a pit length nT, where n=three to eleven, K is a constant (0&#x2266;K&#x2266;1.6), and T is a unit time corresponding to a pit length or a land length at a write-speed; and d) radiating the recording laser beam alternately at the recording power for the controlled radiating time to form pits and at a non-recording power to form lands toward a record surface of a recordable optical disc.

Optical disc recording method and apparatus

In an optical disk recording device for irradiating a recording light beam onto an optical disk to form pits having lengths ranging from 3Ts to 11Ts (where T represents a length of a unit time period in a longitudinal direction of a pit track), a sample and hold circuit samples and holds levels of a reflection signal, representative of a reflection of the recording light beam from the optical disk, for a predetermined time period between points of 1T and 3Ts after the start of a rising edge of the reflection signal. Comparator circuit makes a comparison between the sampled and held levels of the reflection signal and a predetermined reference level. Automatic laser power control circuit controls the power of the recording light beam on the basis of a result of the comparison by the comparator circuit. With such an arrangement, the recording power of the light beam can be controlled promptly with increased accuracy.

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Hamamatsu, Japan

Takashi Nagano