Method and system for erase before write magneto-optic recording
First Claim
1. A method for over-writing data on a magneto-optic recording medium having a compensation temperature tens of degrees C. above room temperature, comprising the steps of:
- (a) erasing any previously recorded magnetic domain in the region on the recording medium to be recorded by temporarily heating the region being erased above the compensation temperature in the absence of any substantial externally provided magnetic bias field to thereby establish a known magnetic state in said recording medium;
(b) receiving data bits to be recorded;
(c) generating a write signal when a data bit and said known state are not the same; and
(d) writing a magnetic domain in said previously erased region only in response to said write signal by temporarily heating an area above the compensation temperature in the absence of any substantial externally provided magnetic bias field.
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Accused Products
Abstract
Method and system for overwriting binary data values in microscopic storage regions of a thin film ferrimagnetic layer without using external magnetic bias aiding the recording process. The ferrimagnetic layer is selected having a compensation temperature at least a few tens of degrees above room temperature. In recording data, any previously recorded data is erased to establish a known state and magnetic domains of reverse magnetic polarity are recorded when the known state differs from the binary data state by temporarily heating an area on the ferrimagnetic layer above the compensation temperature in the absence of any external aiding magnetic bias.
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Citations
13 Claims
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1. A method for over-writing data on a magneto-optic recording medium having a compensation temperature tens of degrees C. above room temperature, comprising the steps of:
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(a) erasing any previously recorded magnetic domain in the region on the recording medium to be recorded by temporarily heating the region being erased above the compensation temperature in the absence of any substantial externally provided magnetic bias field to thereby establish a known magnetic state in said recording medium; (b) receiving data bits to be recorded; (c) generating a write signal when a data bit and said known state are not the same; and (d) writing a magnetic domain in said previously erased region only in response to said write signal by temporarily heating an area above the compensation temperature in the absence of any substantial externally provided magnetic bias field. - View Dependent Claims (2, 3, 4, 5)
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6. A system for over-writing data on a magneto-optic recording medium comprising:
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(a) a thin film ferrimagnetic recording medium with uniaxial anistropy perpendicular to the surface thereof having a compensation temperature sufficiently above room temperature to permit erasure of previously recorded magnetic domains by temporary heating above said compensation temperature without the application of a substantial external magnetic bias field; (b) write means for temporarily heating selected regions of said recording medium above said compensation temperature to create magnetic domains therein using the self-demagnetizing field within said recording medium; (c) erase means for temporarily heating selected regions of said recording medium above said compensation temperature to erase previously created domains using the self-demagnetizing field within a domain being erased to establish a known state in said medium; (d) an erase controller for controlling said erase means to erase regions of said recording medium to be recorded; (e) data receiving means for receiving data bits to be recorded; (f) comparing means for comparing received data with said known state to provide a write signal where a received data bit is different than said known state; and (g) a write controller for controlling said write means to create a magnetic domain only in response to said write signal when said received data bit is different than said known state. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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Specification