Dynamic information storage or retrieval – Information location or remote operator actuated control – Selective addressing of storage medium
Reexamination Certificate
2000-02-08
2002-01-22
Dinh, Tan (Department: 2651)
Dynamic information storage or retrieval
Information location or remote operator actuated control
Selective addressing of storage medium
C369S215100
Reexamination Certificate
active
06341103
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical disk driving apparatus, an optical disk driving method, and an optical disk apparatus. The present invention can be applied to a slide-feed control that is performed when information is recorded, for example, in an optical disk (MO), a compact disk (CD), a direct read after write optical disk (CD-R), or a digital video disk (DVD) or reproduced from it.
2. Description of the Related Art
In the field of recent optical disks, in addition to conventional formats of disks, there are various formats of optical disks such as a direct read after write optical disk (CD-R) having a pigment film coated thereon of organic pigment system, a magnetic disk (MO), a change-of-phase optical disk (DVD-RAM), etc.
In recording and reproducing apparatuses for use on these optical disks, there has been performed a slide-feed (also called “sled”) control that controls the position of an optical spot radiated from an optical pick-up on each track in the radial direction of the rotation surface of the optical disk. With an increase in the recording density, there has been an increasing demand for ensuring the reliability by performing precise control of the radial position of the optical disk.
In conventional recording and reproducing apparatuses of an optical disk, there has been performed slide feed of the optical pick-up by using a DC motor. For this reason, in order to perform high-speed access, a speed sensor or a position detecting sensor was needed.
In the above-described conventional recording and reproducing apparatuses of an optical disk, control became complex due to the addition of the sensors and the use of a special motor driver for control and therefore the cost became high. Furthermore, there was the inconvenience that a relevant mechanism part became complex and large in size due to the use of gears for adding a relevant mechanism as well as the addition of the sensors.
Also, while it is considered more reasonable to use micro-step driving of the stepping motor, instead of a DC motor, this necessitates the use of a single-purpose driver IC. Therefore, the cost is increased. In addition, variations occur in the driven distance due to the rotation of the motor in units of a step. Therefore, there was the inconvenience that the linearity of the rotation deteriorated.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-described respects, and an object of the present invention is to propose an optical disk driving apparatus, an optical disk driving method, and an optical disk apparatus that can each enhance the linearity of the rotation of the motor with a simple construction.
To attain the above object, the present invention provides an optical disk driving apparatus having a slide-feed drive portion that, in order to record information into an optical disk and reproduce information therefrom by radiating an optical spot onto the optical disk by an optical pick-up, causes a change of the incident position of the optical spot radiated from the optical pick-up with respect to a rotation surface of the optical disk, the slide-feed drive portion using a stepping motor as drive means for changing the position of the optical pick-up with respect to the rotation surface of the optical disk, and comprising waveform correcting means for correcting drive current waveforms for driving the stepping motor.
Also, the present invention provides an optical disk driving method performing slide-feed driving that, in order to record information into an optical disk and reproduce information therefrom by radiating an optical spot onto the optical disk by an optical pick-up, causes a change of the incident position of the optical spot radiated from the optical pick-up with respect to a rotation surface of the optical disk, the slide-feed driving comprising correcting drive current waveforms for driving the stepping motor to thereby generate correction drive current waveforms, using the stepping motor when there is performed a drive for changing the position of the optical pick-up with respect to the rotation surface of the optical disk, and driving the stepping motor with the use of the correction drive current waveforms.
Also, the present invention provides an optical disk apparatus having a slide-feed drive portion that, in order to record information into an optical disk and reproduce information therefrom by radiating an optical spot onto the optical disk by an optical pick-up, causes a change of the incident position of the optical spot radiated from the optical pick-up with respect to a rotation surface of the optical disk, the slide-feed drive portion using a stepping motor as drive means for changing the position of the optical pick-up with respect to the rotation surface of the optical disk, and comprising waveform correcting means for correcting drive current waveforms for driving the stepping motor.
The optical disk driving apparatus, optical disk driving method, and optical disk apparatus of the present invention perform the following functions.
A laser beam is radiated from the optical pick-up of optical system onto the optical disk that is rotated by the spindle motor that is servo controlled by a spindle servo-system. After the focus servo that is controlled by the focus servo-system is turned to “on”, a drive signal from the tracking servo-system of the servo-circuit is amplified by the drive amplifier and this drive signal is applied to the tracking coil of the bi-axial actuator of the optical pick-up of optical system. When the actuator is resultantly being moved in the track-crossing direction, a detection signal is detected from the photo-detector of optical system in response to the light reflected from the optical disk. Also, a drive signal from the focus servo-system is amplified by the drive amplifier and this drive signal is applied to the focus of the bi-axial actuator of the optical pick-up of optical system. When the actuator is resultantly being moved in the focus direction, a detection signal is detected from the photo-detector of optical system in response to the light reflected from the optical disk.
The tracking error signal is amplified by the drive amplifier, and this signal is made to be a tracking actuator drive signal, which is applied to the tracking coil of the bi-axial actuator of the optical pick-up of optical system. Also, the focus error signal is amplified by the drive amplifier, and this signal is made to be a focus actuator drive signal, which is applied to the focus coil of the bi-axial actuator of the optical pick-up of optical system.
It is to be noted that, in the optical pick-up of optical system, the objective lens is independently moved in the focus direction or in the tracking direction through the operation of the bi-axial actuator using an electromagnetic force.
Especially, by correcting the motor driving waveforms by the waveform correcting means of the slide-feed motor controller of the slide-feed drive part, the optical pick-up is linearly moved with respect to the rotation of the slide-feed motor using the stepping motor. As a result of this, the optical pick-up of optical system is sequentially linearly moved toward the outer periphery of the optical disk in synchronism with the rotation of the optical disk. As a result of this, the radiation position of a laser beam is linearly displaced toward the outer periphery of the optical disk sequentially.
Also, in the waveform correcting means, the movement distance of the optical pick-up is divided into equal parts at prescribed intervals to thereby make the drive steps of the stepping motor further fine and thereby determine correction steps; armature angles are determined from these correction steps; excitation current waveforms based on the armature angles are determined; data of prescribed bits is determined from the use thereof to thereby determine correction tables; and correction drive current waveforms corresponding to the drive steps are determined based on these corre
Oishi Seiichiro
Shiomi Tetsuhiro
Takeda Ryuji
Dinh Tan
Frommer William S.
Frommer & Lawrence & Haug LLP
Savit Glenn F.
Sony Corporation
LandOfFree
Optical disk apparatus capable of correcting the drive... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical disk apparatus capable of correcting the drive..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical disk apparatus capable of correcting the drive... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2830424