Victor Company of Japan, Limited

Jvc Kenwood Corporation

Kenji Oishi

Tetsuya Kondo

Takashi Ohgo

Itsuro Nakamura

Takayuki Onizawa

Naoyuki Nakagawa

Koji Tsujita

Katsunori Ohshima

Mikiya Kuroda

Toshinori Kawanishi

Osamu Akutsu

Saturo Yamashita

An information recording mediumat least comprises a substratehaving a microscopic pattern, which is constituted by a shape of continuous substance of approximately parallel grooves formed with a groove section G and a land section L alternately, a recording layerformed on the microscopic patternand a light transmission layerformed on the recording layer. The microscopic patternis formed so as to satisfy a relation of P&#x3c;&#x3bb;&#x3c;NA and a thickness of the light transmission layeris within a range of 0.07 to 0.12 mm, wherein P is a pitch of the groove section G or the land section L, &#x3bb; is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens. Further, there provided an information recording medium, which is improved in cross erase and recorded in high density, and a reproducing apparatus and a recording apparatus for the information recording medium.

Recording medium having a substrate containing microscopic pattern of parallel groove and land sections and recording/reproducing equipment therefor

An information recording medium is at least composed of a substrate having a microscopic pattern constituted by a continuous substrate of grooves formed with a groove portion and a land portion alternately, a recording layer formed on the microscopic pattern for recording information, and a light transmitting layer formed on the recording layer. The microscopic pattern is formed with satisfying a relation of P&#x2266;&#x3bb;/NA, wherein P is a pitch of the land portion or the groove portion, &#x3bb; is a wavelength of reproducing light for reproducing the recording layer, and NA is a numerical aperture of an objective lens. The land portion is formed with wobbling so as to be parallel with each other for both sidewalls of the land portion. An auxiliary information based on data used supplementally when recording the information and a reference clock based on a clock used for controlling a recording speed when recording the information is recorded alternately. Information is recorded in the recording layer corresponding to only a land portion by at least either one change of reflectivity difference and refractive index difference in the recording layer so as to be more than 5% for reflectivity and so as to be more than 0.4 for modulated amplitude of signal recording.

Optical recording medium having auxiliary information and reference clock

An information recording medium comprises a substrate, a second recording layer, a second light transmitting layer, a first recording layer for recording different information from that to be recorded in the second recording layer, and a first light transmitting layer. The second recording layer is formed with a continuous second microscopic pattern of grooves. The first recording layer is formed with a continuous first microscopic pattern of grooves that is different from the second microscopic pattern. Both sidewalls of raised portions of the first and second microscopic patterns are formed with wobbling so as to be parallel with each other. Auxiliary information and a reference clock is recorded on these sidewalls alternately and continuously.

Information recording medium, and apparatuses for reproducing, recording, and recording and reproducing thereof, and methods for reproducing, recording, and recording and reproducing thereof

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Yokohama, Japan

Kenji Oishi