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

An information recording medium comprising:

• a substrate having a microscopic pattern, having a continuous shape of approximately parallel grooves formed with alternating groove and land sections;
• a recording layer formed on the microscopic pattern;
• a light transmission layer formed on the recording layer,
• wherein the microscopic pattern is formed so as to satisfy a relation of P<λ/NA and a thickness of the light transmission layer is within a range of 0.07 to 0.12 mm, wherein P is a pitch of the groove section or the land section, λ is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens;
• and
• wherein the land section is wobbled in the radial direction and having a wobbled shape corresponding to a signal to be recorded on the land section resulting from the modulation of a phase modulated wave that is further modulated by a single frequency wave, the single frequency wave having a frequency of integral multiples or one over integral multiples of a frequency of the phase modulated wave, and
• wherein the frequency of the single frequency wave is different from that of the phase modulated wave, and
• wherein information is recorded on the recording layer with controlling modulated amplitude to be more than 0.4.

A reproducing apparatus comprising:

• a recording medium having
• (a) a substrate having a microscopic pattern, having a continuous shape of approximately parallel grooves formed with alternating groove and land sections;
• (b) a recording layer formed on the microscopic pattern;
• (c) a light transmission layer formed on the recording layer;
• wherein the microscopic pattern is formed so as to satisfy a relation of P<λ/NA and a thickness of the light transmission layer is within a range of 0.07 to 0.12 mm, and
• wherein P is a pitch of the groove section or the land section, λ is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens;
• and
• wherein the land section is wobbled in the radial direction and having a wobbled shape corresponding to a signal to be recorded on the land section resulting from the modulation of a phase modulated wave that is further modulated by a single frequency wave, the single frequency wave having a frequency of integral multiples or one over integral multiples of a frequency of the phase modulated wave, and
• wherein the frequency of the single frequency wave is different from that of the phase modulated wave;
• and
• wherein information is recorded on the recording layer with controlling modulated amplitude to be more than 0.4,
• the reproducing apparatus further comprising:
• (d) a pickup composed of a light emitting element having a wavelength of λ within a range of 350 to 450 nm and an objective lens having a numerical aperture of NA within a range of 0.75 to 0.9 for reading out reflected light from the information recording medium;
• (e) a motor for rotating the information recording medium;
• (f) servo means for controlling the drive of the pickup and the motor;
• (g) a turntable for supporting the information recording medium while rotating;
• (h) demodulator means for demodulating an information signal read out by the pickup;
• (i) interface (I/F) means for transmitting a signal demodulated by the demodulator externally;
• (j) controlling means for controlling the entire reproducing apparatus;
• and
• (k) an auxiliary information demodulator for demodulating a differential signal outputted from the pickup.