Rewritable storage apparatus using first and second bias magnetic fields
AssigneeFujitsu Limited
InventorsMasaoki Ohtsuka, Teruji Yamakawa, Tetsuo Maruyama
Life of this patent
Estimating the term…
Abstract
The speed of a write operation in an optical magnetic disk unit is improved by effectively setting the bias magnetic field. When new data is written in an area on a medium, a bias control method for a rewritable storage apparatus which records data by applying a bias magnetic field for data recording and erases recorded data by applying a bias magnetic field for data erasing, applies the bias magnetic field for data erasing to the area to perform an erase operation; applies the bias magnetic field for writing to the area to perform a record operation to record the new data; and applies and maintains the bias magnetic field for data erasing to the medium directly after the record operation is finished.
Claims14
A rewritable storage apparatus which, when new data is recorded in an area on a medium, performs an erase operation to erase data recorded in said area by applying a second bias magnetic field for data erasing to said area then performs a record operation to record said new data by applying a first bias magnetic field for data recording to said area, comprising:
- a bias application unit for applying said bias magnetic field to said medium, said bias magnetic field being switchable between said first bias magnetic field and said second bias magnetic field;
- and
- a bias control means for controlling said bias application unit so that said second bias magnetic field for data erasing is applied to said medium directly after said record operation is finished and said second bias magnetic field for data erasing is maintained.
A rewritable storage apparatus which, when new data is recorded in an area on an optically recording medium, performs an erase operation to erase data recorded in said area by applying a second bias magnetic field for data erasing to said area then performs a record operation to record said new data by applying a first bias magnetic field for data recording to said area, comprising:
- an optical head mechanism for projecting a laser beam onto an area on said optically recording medium;
- a bias application unit for applying said bias magnetic field to said medium, said bias magnetic field being switchable between said first bias magnetic field and said second bias magnetic field;
- and
- a bias control means for controlling said bias application unit so that said second bias magnetic field for data erasing is applied to said medium directly after said record operation is finished and said second bias magnetic field for data erasing is maintained.
A bias control method for a rewritable storage apparatus which records data by applying a first bias magnetic field for data recording and which erases data by applying a second bias magnetic field for data erasing, comprising:
- when recording new data in an area on a medium in which data was already recorded,
- applying said second bias magnetic field to said area to perform an erase operation to erase data recorded in said area;
- applying said first bias magnetic field to said area to perform a record operation to record said new data;
- and
- applying said second bias magnetic field to said medium directly after said record operation is finished, and maintaining the application of said second bias magnetic field.
Dependencies are inferred from the claim text.