Method for reading magnetic super resolution type magneto-optical recording medium

• US 6,188,649 B1
• Filed: 10/19/1999
• Issued: 02/13/2001
• Est. Priority Date: 06/28/1996
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Birukawa, Masahiro, Hino, Yasumori, Miyatake, Norio
• Primary Examiner(s): Neyzari, Ali
• Application Number:
  US09/420,686
• Time in Patent Office: 483 Days
• Field of Search: 369/13, 369/116, 369/275.2, 369/275.3, 369/110, 369/288, 369/283, 369/14, 429/694.EC, 429/694.ML, 429/694.MM
• US Class Current: 369/13.05
• CPC Class Codes: G11B 11/10508 by modulating only the magnetic field at the transducer
• CPC Class Codes: G11B 11/10513 one of the light beam or the magnetic field being modulated by data and the other by a clock or frequency generator
• CPC Class Codes: G11B 11/10515 Reproducing compensating pit shift G11B11/1053
• CPC Class Codes: G11B 11/10523 Initialising
• CPC Class Codes: G11B 11/10573 Control of relative positioning of the magnetic and optical transducers, e.g. to move simultaneously
• CPC Class Codes: G11B 11/10595 Control of operating function
• CPC Class Codes: G11B 5/59677 with optical servo tracking

Abstract

A reading method for a magneto-optical recording medium is provided, irradiating laser light as a reading beam and using a magnetic head. High density and high transmission rate are possible and a correct reading can be performed according to the length of recording marks by reading the magneto-optical recording medium while impressing a magnetic field with an orientation promoting the translation of magnetic domain walls. In the magnetic super resolution type magneto-optical recording medium, which attains a signal only from one portion of the irradiation domain of the reading beam and has at least a recording layer and a reading layer on a substrate, the focused laser light is irradiated as a reading beam and the magnetic field is modulated, using the magnetic head, which is equipped with a slider and glides or floats on the recording medium. The magneto-optical recording medium is read, while impressing a magnetic field 161 that accelerates at least the transcription of the magnetization of the recording layer into the reading layer.

Claims

1. A reading method for a magnetic super resolution type magneto-optical recording medium, comprising performing reading by a reading light beam while impressing a magnetic field with an electromagnet type magnetic head that is equipped with a slider and glides or floats on a magneto-optical recording medium that attains a signal only from one portion of the irradiation domain of the reading beam, wherein the same conditions as for a reading mode are maintained in a stand-by state for reading, but the driving current for the magnetic head is made smaller than in the reading state, and a fixed reading magnetic field is impressed when switching from the stand-by state to the reading state.

2. The reading method for a magneto-optical recording medium according to claim 1, wherein the laser power in the stand-by state for reading is smaller than the reading power and the laser power is increased when the state of stand-by is shifted to the state of reading.