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US 6,285,634 B1Granted
Bias voltage controlling apparatus, information reproducing apparatus and information recording apparatus
AssigneePioneer Corporation
InventorsShinichiro Abe, Takayuki Iijima, Minoru Yoshioka
Life of this patent
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Abstract
A bias voltage controlling apparatus controls a bias voltage for a focus servo control to control a position of a focal point of a light beam, which is irradiated onto an information record surface of an information record medium, in a direction perpendicular to the information record surface. The bias voltage controlling apparatus is provided with: a distinguishing device for distinguishing a type of the information record medium; and a controlling device for optimally controlling the bias voltage on the basis of the type of the information record medium distinguished by the distinguishing device.
Claims7
A bias voltage controlling apparatus for controlling a bias voltage for a focus servo control to control a position of a focal point of a light beam, which is irradiated onto an information record surface of an information record medium, in a direction perpendicular to the information record surface, said bias voltage controlling apparatus comprising:
- a distinguishing device for distinguishing a type of said information record medium;
- and
- a controlling device for optimally controlling the bias voltage on the basis of the type of said information record medium distinguished by said distinguishing device, wherein said controlling device controls the bias voltage so as to reduce a change of a reflection light signal, which is generated in correspondence with a reflection light of the light beam reflected from the information record surface, on a time axis on the basis of the type of said information record medium distinguished by said distinguishing device, and
- wherein said controlling device comprises:
- a first controlling device for controlling the bias voltage so as to maximize a level of the reflection light signal;
- and
- a second controlling device for controlling the bias voltage so as to reduce the change of the reflection light signal on the time axis, on the basis of the type of said information record medium distinguished by said distinguishing device, after the level of the reflection light signal is maximized by said first controlling device.
4 more elements
An information reproducing apparatus comprising:
- (i) a bias voltage controlling apparatus for controlling a bias voltage for a focus servo control to control a position of a focal point of a light beam, which is irradiated onto an information record surface of an information record medium, in a direction perpendicular to the information record surface, said bias voltage controlling apparatus comprising:
- a distinguishing device for distinguishing a type of said information record medium;
- and
- a controlling device for optimally controlling the bias voltage on the basis of the type of said information record medium distinguished by said distinguishing device,
- (ii) a light emitting device for emitting the light beam onto the information record surface in accordance with the controlled bias voltage, and
- (iii) a reproducing device for reproducing information recorded on said information record surface on the basis of the reflection light signal,
- wherein said controlling device controls the bias voltage so as to reduce a change of a reflection light signal, which is generated in correspondence with a reflection light of the light beam reflected from the information record surface, on a time axis on the basis of the type of said information record medium distinguished by said distinguishing device, and
- wherein said controlling device comprises:
- a first controlling device for controlling the bias voltage so as to maximize a level of the reflection light signal;
- and
- a second controlling device for controlling the bias voltage so as to reduce the change of the reflection light signal on the time axis, on the basis of the type of said information record medium distinguished by said distinguishing device, after the level of the reflection light signal is maximized by said first controlling device.
8 more elements
An information recording apparatus comprising:
- (i) a bias voltage controlling apparatus for controlling a bias voltage for a focus servo control to control a position of a focal point of a light beam, which is irradiated onto an information record surface of an information record medium, in a direction perpendicular to the information record surface, said bias voltage controlling apparatus comprising:
- a distinguishing device for distinguishing a type of said information record medium;
- and
- a controlling device for optimally controlling the bias voltage on the basis of the type of said information record medium distinguished by said distinguishing device, and
- (ii) a recording device for emitting the light beam, which corresponds to record information to be recorded, onto the information record surface in accordance with the controlled bias voltage, to thereby record the record information onto said information record surface,
- wherein said controlling device controls the bias voltage so as to reduce a change of a reflection light signal, which is generated in correspondence with a reflection light of the light beam reflected from the information record surface, on a time axis on the basis of the type of said information record medium distinguished by said distinguishing device, and
- wherein said controlling device comprises:
- a first controlling device for controlling the bias voltage so as to maximize a level of the reflection light signal;
- and
- a second controlling device for controlling the bias voltage so as to reduce the change of the reflection light signal on the time axis, on the basis of the type of said information record medium distinguished by said distinguishing device, after the level of the reflection light signal is maximized by said first controlling device.
7 more elements
Dependencies are inferred from the claim text.