# US 7,411,885 B2 · Method of determining the time of adjusting writing strategy of an optical drive

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- Number: US 7,411,885 B2
- Document ID: US7411885B2
- Status: Granted
- Kind: B2
- Application number: 11/075,715
- Filed: 2005-03-10
- Published: 2005-09-29
- Granted: 2008-08-12
- Earliest claimed: 2004-03-26
- Assignees: Lite-On It Corporation
- Inventors: Chi-Yuan Liu
- Web page: https://patentgrep.com/patent/US7411885B2

## CPC

- G11B 7/1263: Power control during transducing, e.g. by monitoring
- G11B 7/0062: {Overwriting strategies, e.g. recording pulse sequences with erasing level used for phase-change media}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

A method of determining the time of adjusting writing strategy of an optical drive. Firstly, relation between an output signal value and an ambient temperature is recorded in a look up table stored in a memory. Then, the output signal value of a compensator can be obtained by looking up the look up table according to the ambient temperature of the optical drive. When the ambient temperature is higher than a predetermined temperature, the optical drive adjusts the writing strategy.

## Claims

### Claim 1

A method of determining time of adjusting writing strategy of an optical drive to control a closed-loop control circuit for controlling an output power of a laser diode, the method comprising the steps of:
receiving an output signal outputted from a compensator;
converting the output signal into an output signal value by way of analog-to-digital conversion;
converting the output signal value into an ambient temperature value according to a look up table; and
adjusting the writing strategy when the ambient temperature value is higher than a predetermined temperature.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the look up table records relation between the output signal value and the ambient temperature value.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the look up table is a ROM (Read Only Memory).

### Claim 4 (depends on 1)

The method according to claim 1, wherein the closed-loop control circuit comprises:
a DAC (Digital Analog Converter) for receiving a digital control signal and generating an analog control signal according to the digital control signal;
the compensator for receiving a difference between the analog control signal and a feedback signal and generating the output signal;
an amplifier for receiving the output signal and outputting a driving current;
the laser diode for receiving the driving current and generating a laser beam; and
a FMD (Front Monitor Diode) for receiving the laser beam and then generating the feedback signal.

### Claim 5

A method of determining time of adjusting writing strategy of an optical drive to control a closed-loop control circuit for controlling an output power of a laser diode, the method comprising the steps of:
receiving an output signal outputted from a compensator;
converting the output signal into an output signal value by way of analog-to-digital conversion; and
adjusting the writing strategy when the output signal value is greater than an output signal threshold value.

### Claim 6 (depends on 5)

The method according to claim 5, wherein the output signal threshold value is stored in a ROM (Read Only Memory).

### Claim 7 (depends on 5)

The method according to claim 5, wherein the closed-loop control circuit comprises:
a DAC (Digital Analog Converter) for receiving a digital control signal and generating an analog control signal according to the digital control signal;
the compensator for receiving a difference between the analog control signal and a feedback signal and generating the output signal;
an amplifier for receiving the output signal and outputting a driving current;
the laser diode for receiving the driving current and generating a laser beam; and
a FMD (Front Monitor Diode) for receiving the laser beam and then generating the feedback signal.