Patent EA-003068-B1 (EA)
Title: Method and apparatus foe recording and reproducing optical information (variants)
Inventor: HORIMAI HIDEYOSHI
IPC: G11B7/24
Filed: 1999-02-26
Abstract: 1. An optical information recording apparatus for recording information in an optical information recording medium having an information recording layer in which information is recorded utilizing holography, the apparatus comprising: information light generation means for generating information light carrying information; recording reference light generation means including phase modulation means for spatially modulating the phase of light, for generating reference light for recording having a phase spatially modulated by the phase modulation means; and a recording optical system for illuminating the information recording layer on the same side thereof with the information light generated by the information light generation means and the reference light for recording generated by the recording reference light generation means such that the information is recorded in the information recording layer in the form of an interference pattern as a result of interference between the information light and the reference light for recording, wherein the optical information recording medium has a positioning region for recording information for positioning the information light and the reference light for recording, the apparatus further comprising position control means for controlling the positions of the information light and the reference light for recording relative to the optical information recording medium using the information recorded in the positioning region. 2. An optical information recording apparatus according to claim 1, wherein the recording optical system projects the information light and the reference light for recording such that the optical axis of the information light and the optical axis of the reference light for recording are located on the same line. 3. An optical information recording method for recording information in an optical information recording medium having an information recording layer in which information is recorded utilizing holography, the method comprising the steps of: generating information light carrying information; spatially modulating the phase of light to generate reference light for recording having a spatially modulated phase; and illuminating the information recording layer on the same side thereof with the information light and the reference light for recording to record the information in the information recording layer in the form of an interference pattern as a result of interference between the information light and the reference light for recording,  wherein the optical information recording medium has a positioning region for recording information for positioning the information light and the reference light for recording, the method further comprising position control means for controlling the positions of the information light and the reference light for recording relative to the optical information recording medium using the information recorded in the positioning region. 4. An optical information reproducing apparatus for reproducing information utilizing holography from an optical information recording medium having an information recording layer in which the information is recorded in the form of an interference pattern as a result of interference between information light carrying the information and reference light for recording having a spatially modulated phase, the apparatus comprising: reproduction reference light generation means including phase modulation means for spatially modulating the phase of light, for generating reference light for reproduction having a phase spatially modulated by the phase modulation means; a reproducing optical system for illuminating the information recording layer with the reference light for reproduction generated by the reproduction reference light generation means and for collecting reproduction light generated at the information recording layer when illuminated with the reference light for reproduction on the same side of the information recording layer that is illuminated with the reference light for reproduction; and detection means for detecting the reproduction light collected by the reproducing optical system. 5. An optical information reproducing apparatus according to claim 4, wherein the optical information recording medium has a positioning region for recording information for positioning the reference light for reproduction, the apparatus further comprising position control means for controlling the position of the reference light for reproduction relative to the optical information recording medium using the information recorded in the positioning region. 6. An optical information reproducing apparatus according to claim 4, wherein the reproducing optical system projects the reference light for reproduction and collects the reproduction light such that the optical axis of the reference light for reproduction and the optical axis of the reproduction light are located on the same line. 7. An optical information reproducing apparatus according to claim 4, wherein the reproduction reference light generation means generates the reference light for reproduction in a plurality of wavelength bands, and the detection means detects the reproduction light in the same plurality of wavelength bands. 8. An optical information reproducing method for reproducing information utilizing holography from an optical information recording medium having an information recording layer in which the information is recorded in the form of an interference pattern as a result of interference between information light carrying the information and reference light for recording having a spatially modulated phase, the method comprising the steps of: spatially modulating the phase of light to generate reference light for reproduction having a spatially modulated phase; illuminating the information recording layer with the reference light for reproduction and collecting reproduction light generated at the information recording layer when illuminated with the reference light for reproduction on the same side of the information recording layer that is illuminated with the reference light for reproduction; and detecting the collected reproduction light. 9. An optical information recording apparatus for recording information in an optical information recording medium having an information recording layer in which a change in absorbance occurs in an absorption spectrum thereof in the position of a wavelength of incident light and in which information is recorded utilizing holography, the apparatus comprising: wavelength selection means for selecting a wavelength of light illuminating the information recording layer from among a plurality of wavelengths; information light generation means for generating information light having the wavelength selected by the wavelength selection means and carrying information; recording reference light generation means for generating reference light for recording having the wavelength selected by the wavelength selection means; and a recording optical system for illuminating the information recording layer on the same side thereof with the information light generated by the information light generation means and the reference light for recording generated by the recording reference light generation means such that the information is recorded in the information recording layer in the form of an interference pattern as a result of interference between the information light and the reference light for recording, wherein the optical information recording medium has a positioning region for recording information for positioning the information light and the reference light for recording, the apparatus further comprising position control means for controlling the positions of the information light and the reference light for recording relative to the optical information recording medium using the information recorded in the positioning region. 10. An optical information recording apparatus according to claim 9, wherein the recording optical system projects the information light and the reference light for recording such that the optical axis of the information light and the optical axis of the reference light for recording are located on the same line. 11. An optical information recording method for recording information in an optical information recording medium having an information recording layer in which a change in absorbance occurs in an absorption spectrum thereof in the position of a wavelength of incident light and in which information is recorded utilizing holography, the method comprising the steps of: selecting a wavelength of light illuminating the information recording layer from among a plurality of wavelengths; generating information light having the selected wavelength and carrying information; generating reference light for recording having the selected wavelength; and illuminating the information recording layer on the same side thereof with the information light and the reference light for recording to record the information in the information recording layer in the form of an interference pattern as a result of interference between the information light and the reference light for recording, wherein the optical information recording medium has a positioning region for recording information for positioning the information light and the reference light for recording, the method further comprising position control means for controlling the positions of the information light and the reference light for recording relative to the optical information recording medium using the information recorded in the positioning region. 12. An optical information reproducing apparatus for reproducing information utilizing holography from an optical information recording medium having an information recording layer in which the information is recorded in the form of an interference pattern as a result of interfere