IP Library › Granted Patent US 8,325,772
Granted Patent B2
US 8,325,772 · App. 12/839,639 · Granted Dec 4, 2012

Optical disk apparatus and information recording method

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Quick Facts
Patent No.
US 8,325,772
App. No.
12/839,639
Granted
Dec 4, 2012
Kind
B2
Abstract

In an optical disk apparatus, by obtaining the temperature in the vicinity of a laser in the apparatus, the power source voltage of the laser driver is controlled such that power consumed by the headroom of the laser driver is reduced to the maximum extent without deteriorating the current drive characteristic of the headroom when the temperature becomes higher. The laser driving current of the laser driver is monitored to control the power source of the laser driver such that the power consumed by the headroom is possibly reduced while maintaining the current drive characteristic of the headroom for the monitored current.

Claims (19)

1. An optical disc apparatus comprising:

a laser for emitting a laser beam onto an optical disc;

a laser driver for supplying power to the laser;

a power source for supplying power to the laser driver;

a laser emission power monitoring element for monitoring laser emission power of the laser, and for outputting data based on an amount of the laser emission power monitored;

a detecting circuit for detecting the data outputted from the laser emission power monitoring element; and

a microcomputer for receiving the data from the detecting circuit, and for the controlling power source so as to change an amount of voltage to be supplied to the laser driver in accordance with an amount of the laser emission power indicated by the data, wherein the change in the amount of voltage causes an amount of power consumption of the power source to be reduced, and wherein the power consumption is reduced to the maximum extent possible without deteriorating laser driving characteristic.

2. The optical disc apparatus according to claim 1 , wherein the microcomputer is configured to increase an amount of voltage to be supplied to the laser driver if the amount of the laser emission power indicated by the data increases, and to decrease the amount of voltage to be supplied to the laser driver if the amount of the laser emission power indicated by the data decreases.

3. The optical disc apparatus according to claim 1 , wherein the microcomputer is configured to decrease an amount of voltage to be supplied to the laser driver if the laser emission power indicated by the data increases, and to increase the amount of voltage to be supplied to the laser driver if the laser emission power indicated by the data decreases.

4. The optical disc apparatus according to claim 1 , wherein the laser emission power monitoring element comprises a monitor diode.

5. An information recording method for use with an optical disc apparatus comprising the steps of:

emitting a laser beam onto an optical disc at a laser;

supplying power to a laser driver;

monitoring a laser emission power of the laser;

producing data indicative of an amount of the laser emission power of the laser;

receiving the data by a microcomputer; and

the microcomputer controlling a power source so as to change an amount of voltage supplied to the laser driver in accordance with the amount of the laser emission power indicated by the data, wherein the change in the amount of voltage causes an amount of power consumption of the power source to be reduced, and wherein the power consumption is reduced to the maximum extent possible without deteriorating laser driving characteristic.

6. The information recording method according to claim 5 , further comprising the microcomputer increasing an amount of voltage to be supplied to the laser driver if the amount of the laser emission power indicated by the data increases, and decreasing the amount of voltage to be supplied to the laser driver if the amount of the laser emission power indicated by the data decreases.

7. The information recording method according to claim 5 , further comprising the microcomputer decreasing an amount of voltage to be supplied to the laser driver if the amount of the laser emission power indicated by the data increase, and increasing the amount of voltage to be supplied to the laser driver if the amount of the laser emission power indicated by the data decreases.