Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Tetsuya Akiyama

Kenichi Nishiuchi

Shigeaki Furukawa

Kenji Narumi

Naoyasu Miyagawa

Takeo Ohta

Hiroyuki Yamaguchi

Hidemi Isomura

Takashi Ishida

Atsushi Nakamura

Nobuo Akahira

Mamoru Shoji

Shunji Ohara

Yasuhiro Gotoh

Katsumi Kawahara

Kazumi Yoshioka

Noboru Yamada

Shinya Abe

Eiji Ohno

Masahiko Tsukuda

Takashi Nishihara

Ken'ichi Nagata

Hideki Kitaura

Tomoyasu Takaoka

Tomoyoshi Miyake

When the power of the write pulse is taken as the peak power and the power of the bottom pulse is taken as the bottom power, the power setting device () sets the power of each pulse in the recording pulse train such that the peak power PwN of the Nth information layer which is closest to the light entry surface of the optical recording medium (), the bottom power PbN of the Nth information layer, the peak power PwM of the Mth information layer (where M is an integer such that N&#x3e;M&#x2267;1), and the bottom power PbM of the Mth information layer satisfy the following formula:

Optical information recording device, optical information recording method and optical information recording medium

An optical recording medium that allows information to be recorded and played back properly, even when a type of recording medium in which information is recorded to grooves is used along with a type of recording medium in which information is recorded to lands, as well as a method for recording and playback with this medium. Recording track information is recorded in advance, indicating whether information is to be recorded in the grooves or the lands, whichever of the grooves and lands is best suited to the recording of information is selected on the basis of the recording track information that is read out, and the recording or playback of information is performed.

Optical recording medium, method for manufacturing the same, recording/playback method, and recording/playback apparatus

An optical information recording medium includes a plurality of recording layers, a reflectance of at least one of the plurality of the recording layers in a non-initialized state with respect to a light beam for initialization being smaller than a reflectance of the same in an initialized state with respect to the light beam for initialization. The recording layers are initialized by irradiating, among the plurality of recording layers, the recording layer positioned farther from a light beam irradiation side with the light beam prior to irradiating the recording layer positioned closer to the light beam irradiation side, so that the initialized recording layers have no initialization irregularities. In initialization, at a position at a same distance in a radial direction on the optical information recording medium, the recording layer positioned farther from a light beam irradiation side is irradiated with one light beam before the recording layer positioned closer to the light beam irradiation side is irradiated with another light beam so that the plurality of recording layers are initialized at the same time by a light beam projecting operation in which the light beams are focused at different positions. This ensures the initialization without irregularities within a short time.

Optical information recording medium, method for manufacturing the same, and initialization device

A multi pulse sectionis generated in the mark forming portion corresponding to a markhaving a length nTw (n&#x2267;=2), where Tw represents a reference clock cycle. The multi pulse sectionconsists of pulses of the number (n&#x2212;1) each having the power level a, and pulses of the number (n&#x2212;2) each having the power level b (b&#x3c;a), each of which is formed between the adjoining pulses having the power level a. Further, a heat blocking pulsehaving the power level c (c&#x3c;a) is generated immediately after the multi pulse section. A bias sectionhaving the power level d (c&#x3c;d&#x3c;a) is generated between the heat blocking pulseand a succeeding multi pulse section. The bias sectioncorresponds to a space. The time length tc of the heat blocking pulseis: tc&#x2267;Tw. With this arrangement, information can be precisely recorded in and reproduced from a WORM type information recording medium.

Apparatus for recording information in information recording medium, information recording medium, method for recording information in information recording medium, program for recording information in information recording medium, and program product

A substrate for an optical recording medium includes recording tracks formed in guide grooves on a disc and an address section having an address pit sequence formed between the recording tracks in the guide grooves along an information reading direction of the recording tracks. The recording tracks in the guide grooves are divided into a prescribed number of zones. In each of the zones, the center of the address section corresponding to a recording track in the radially outermost or radially innermost guide groove is disposed so as to shift in a radial direction of the disc in relative relationship to the center of the recording track in the guide groove.

Substrate for optical recording medium, optical recording medium, master disc, master disc recording apparatus, and signal generating apparatus

An optical recording medium of the present invention includes a substrate (), a protection plate (), and a plurality of information layers () sandwiched between the substrate and the protection plate. An information signal is recorded as a length of a mark and a length of a space between two marks. The mark is formed when the information layer is irradiated by light received through the substrate. The information layers have a management region () recording a leading edge recording condition and a trailing edge recording condition. The leading edge recording condition is used to change a recording start position for forming a leading edge of the mark. The trailing edge recording condition is used to change a recording end position for forming a trailing edge of the mark. Each of the leading and trailing edge recording condition is depending on which information layer is recorded.

Optical recording medium, method for recording on optical record medium, and apparatus for recording on optical record medium

A method and an apparatus are provided, which enable a user's standby time to be shortened or utilized effectively in the course of recording/reproduction of information with respect to an optical disk. Information recorded on a disk is reproduced preferentially, and after counting for a predetermined period of time, recording learning is conducted. Alternatively, management information is reproduced preferentially over recording learning, and recording learning is conducted while a user is confirming this information. Alternatively, the possibility of recording on a disk is identified, and reproduction preference or recording learning preference processing is conducted based the possibility. Alternatively, a rotation speed of a disk is controlled to be variable or constant, based on the possibility of recording.

Method and apparatus for recording/reproducing information with respect to optical recording medium

A plurality of optical heads each of which comprises an independent light source and optical system are provided on the same side with respect to a recording medium having a plurality of recording layers. Alternatively, with respect to at least one light source in an optical head having a single objective lens and a plurality of light sources, an optical path correction system is provided on an optical path unique to the light source, and while light emitted from one light source is focused on a specific recording layer by shifting of the objective lens, light irradiated from another light source is focused on another recording layer by the optical path correction system. Thus, information can be reproduced from or recorded in a plurality of recording layers simultaneously and an error in focusing of light onto the plurality of recording layers can be suppressed.

Recording/reproducing apparatus with optical path correction system

A method by which, in an optical disk recording and reproducing device, the time required for a test recording performed prior to an actual information recording can be reduced according to characteristics of an optical disk. A random pattern signal is transmitted from a random pattern signal generating circuitand recorded on a test track on an optical disk, and a bit error rate of a reproduction signal is measured. Only when a value of the bit error rate is not less than a fixed value, test pattern signals are transmitted from a test pattern signal generating circuitand recorded. An edge timing of a reproduction signal is measured by an edge timing detecting circuitBased on a result of the measurement, edge positions of a front-end pulse and a back-end pulse are corrected.

Method for optically recording information and device for optically recording information by the same

The width W of the address pit () of an optical recording medium of intermediate address type is determined by W=k Tp/(&#x3bb;/NA) where &#x3bb; is the laser wavelength of the optical head of the optical disk device use, NA is the numerical aperture of the objective, Tp is the track pitch of the record medium, and k is 0.40&#x2266;k&#x2266;0.68. Alternatively, an optical device comprises a first address demodulating circuit for demodulating address information by using a signal that is the sum of the electric signals outputted from a pair of photodetectors separated in the direction of the track and a second address demodulating circuit for demodulating address information by suing a signal that is the difference between the electric signals. The address is detected base on the information thus obtained. In such a way, the compatibility of the recording medium used and that of the optical device are improved, the reproduction margin in demodulating the address information is increased, realizing high accuracy address detection when reproducing data from an optical recorded medium of intermediate address type.

Optical recording medium with address information composed of pits

Recording/reproducing apparatus for optical information recording medium and optical head

The present invention relates to an optical information recording medium including a disk-shaped transparent substrate and a recording layer for recording, reproducing or erasing information by irradiation of laser light, the recording layer being formed over the substrate. The recording layer of the present invention includes information tracks including groove tracks and land tracks that are formed alternately in a radial direction of the disk. The information tracks comprise information recording regions and address regions interposed between the information recording regions, the information recording regions and the address regions being arranged along the tracking direction of the laser light. In the information recording regions, every second step in the radial direction of steps for dividing the groove tracks from the land tracks adjacent to the groove tracks is wobbled in the tracking direction, and in a range whose ends are defined by the address regions the every second step is wobbled at a constant frequency. Prepit addresses for providing information on a position on the recording medium are formed on the address regions. Moreover, the present invention provides an optical information recording medium including n recording layers (where n is an integer of at least 2), and in at least the first recording layer to the (n-1)th recording layer from the transparent substrate side, no pair of adjacent address regions in the radial direction of the disk are arranged so as to be aligned on a straight line passing through the center of the disk.

Optical information recording medium, and method and apparatus for recording/reproducing information thereon

A method by which, in an optical disk recording and reproducing device, the time required for a test recording performed prior to an actual information recording can be reduced according to characteristics of an optical disk. A random pattern signal is transmitted from a random pattern signal generating circuitand recorded on a test track on an optical disk, and a bit error rate of a reproduction signal is measured. Only when a value of the bit error rate is not less than a fixed value, test pattern signals are transmitted from a test pattern signal generating circuitand recorded. An edge timing of a reproduction signal is measured by an edge timing detecting circuit. Based on a result of the measurement, edge positions of a front-end pulse and a back-end pulse are corrected.

An optical information recording medium includes: a substantially disk-shaped substrate; and a recording layer formed on a surface of the substrate for recording, reproducing and erasing information by irradiation with a laser beam. A test recording region for test recording and an information recording region for recording the information at least are arranged on the surface of the substrate. In the test recording region and the information recording region arranged on the surface of the substrate, a test recording track and an information recording track respectively are formed in a spiral-shaped arrangement or in a concentric arrangement. A track pitch of the test recording track is wider than a track pitch of the information recording track.

Optical information recording medium, recording/reproducing apparatus and recording /reproducing method for the same, and method for manufacturing optical information recording medium

The present invention relates to an optical information recording medium including a disk-shaped transparent substrate and a recording layer for recording, reproducing or erasing information by irradiation of laser light, the recording layer being formed over the substrate. The recording layer of the present invention includes information tracks including groove tracks and land tracks that are formed alternately in a radial direction of the disk. The information tracks comprise information recording regions and address regions interposed between the information recording regions, the information recording regions and the address regions being arranged along the tracking direction of the laser light. In the information recording regions, every second step in the radial direction of steps for dividing the groove tracks from the land tracks adjacent to the groove tracks is wobbled in the tracking direction, and in a range whose ends are defined by the address regions the every second step is wobbled at a constant frequency. Prepit addresses for providing information on a position on the recording medium are formed on the address regions. Moreover, the present invention provides an optical information recording medium including n recording layers (where n is an integer of at least 2), and in at least the first recording layer to the (n&#x2212;1)th recording layer from the transparent substrate side, no pair of adjacent address regions in the radial direction of the disk are arranged so as to be aligned on a straight line passing through the center of the disk.

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Hirakata, Japan

Tetsuya Akiyama