IP Library Granted Patent US 7,623,417
Granted Patent B2
US 7,623,417 · App. 11/569,517 · Granted Nov 24, 2009

Optical disk device

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Quick Facts
Patent No.
US 7,623,417
App. No.
11/569,517
Granted
Nov 24, 2009
Kind
B2
Abstract

In an optical pickup driving mechanism using a stepping motor, a feeding operation of an optical pickup can be stabilized even in a broad operating temperature environment. In executing an optical axis correction feeding operation in response to an amount of lens shift of an objective lens of an optical pickup, a stepping motor controlling portion drives a stepping motor in a microstep drive mode to move a base of the optical pickup in a radial direction of an optical disk. At this time, a temperature sensor senses an in-equipment temperature, and a driving current supply time deciding portion sets a supply time width of a pulse driving current whose envelope is like a sinusoidal wave to a supply time width as a fixed value, which is longer than that at an ordinary time, or a supply time width, which is multiplied by a coefficient corresponding to the in-equipment temperature, to increase a current supply time of the driving current when the sensed in-equipment temperature is equal to or lower than a predetermined temperature.

Claims (12)

1. An optical disk device, comprising:

an optical pickup that reads information recorded on an optical disk;

a stepping motor that moves the optical pickup in a radial direction of the optical disk;

a driving current supplying unit that supplies a driving current to drive the stepping motor, and executes selectively a full step drive and a microstep drive;

a full step drive deciding unit that decides whether or not an operation performed when the optical pickup is moved in the full step drive is normally ended;

a drive controlling unit that executes drive control of the stepping motor by changing the driving current applied in the microstep drive in response to a decision result;

an optical pickup position sensing unit that senses whether or not a movement of the optical pickup to a predetermined position of an inner circumference of the optical disk is completed; and

a moving time deciding unit that decides a moving time required until the optical pickup is moved to the predetermined position of the inner circumference in the full step drive,

wherein the driving current supplying unit supplies an intermittent driving current at a predetermined time width to the stepping motor in executing the microstep drive; and

wherein the drive controlling unit changes a supply time width of the driving current in response to the moving time of the optical pickup.

2. The optical disk device according to claim 1 , wherein the drive controlling unit changes the supply time width of the driving current into an increased value when the moving time is equal to or greater than a predetermined value.

3. An optical disk device according to claim 1 , wherein a decision regarding a drive of the optical pickup in the full step drive is performed during an inner circumferential feeding operation which is applied to initialize a position of the optical pickup immediately after the optical disk device is started.

Assignments (4)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 28, 2024
From: PANASONIC HOLDINGS CORPORATION
To: PANASONIC AUTOMOTIVE SYSTEMS CO., LTD.
Reel/Frame 066703/0278 →
CHANGE OF NAME Recorded Feb 21, 2024
From: PANASONIC CORPORATION
To: PANASONIC HOLDINGS CORPORATION
Reel/Frame 066644/0558 →
CHANGE OF NAME Recorded Nov 14, 2008
From: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
To: PANASONIC CORPORATION
Reel/Frame 021835/0446 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 2, 2007
From: SHIGETA, TAKAHARU
To: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Reel/Frame 019238/0618 →