Optical disc apparatus, information recording method, and optical disc
AssigneesHitachi Consumer Electronics Co., Ltd., Hitachi-LG Data Storage, Inc.
InventorTakakiyo YASUKAWA
Life of this patent
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Abstract
The invention prevents mark distortion during high-speed recording on an optical disc, thereby improving recording performance. A write pulse signal includes mark periods during which marks 201 are formed and space periods during which no marks are formed. Particular mark periods include a top pulse 101 having first write power Pw; a bias pulse 102 that follows the top pulse 101 and has bias power Pm lower than the first write power Pw; and a last pulse 103 that follows the bias pulse 102 and has second write power Pl lower than the first write power Pw.
Claims7
An optical disc apparatus for irradiating an optical disc with laser light to form a mark based on information, the apparatus comprising:
- an optical pickup mechanism having a laser light source to irradiate the optical disc with laser light;
- a pulse generating circuit for generating a write pulse signal based on the information;
- and
- a laser power control circuit for controlling the luminescent power of the laser light source based on the write pulse signal,
- wherein the write pulse signal includes a mark period during which the mark is formed and a space period during which the mark is not formed and
- wherein the mark period includes:
- a top pulse having first write power Pw;
- a bias pulse that follows the top pulse and has bias power Pm lower than the first write power Pw;
- and
- a last pulse that follows the bias pulse and has second write power Pl lower than the first write power Pw.
An information recording method for irradiating an optical disc with laser light to form a mark based on information, the method comprising the steps of:
- generating a write pulse signal based on the information;
- and
- driving a laser light source based on the write pulse signal to irradiate the optical disc with laser light,
- wherein the write pulse signal includes a mark period during which the mark is formed and a space period during which the mark is not formed and
- wherein the mark period include:
- a top pulse having first write power Pw;
- a bias pulse that follows the top pulse and has bias power Pm lower than the first write power Pw;
- and
- a last pulse that follows the bias pulse and has second write power Pl lower than the first write power Pw.
An optical disc onto which laser light is radiated for recording information, wherein when a write pulse signal used for forming marks based on the information includes a top pulse, a bias pulse, and a last pulse in this order, the optical disc stores, as disc management information, the values of:
- first write power Pw for the top pulse;
- bias power Pm for the bias pulse that is lower than the first write power Pw;
- and second write power Pl for the last pulse that is lower than the first write power Pw.
Dependencies are inferred from the claim text.