摘要:
A hologram recording and reproducing device controls an optical beam output from an external cavity semiconductor laser to improve a diffraction efficiency. The hologram recording and reproducing device includes an external cavity laser, a photodiode, a laser drive circuit and a laser diode controller. The external cavity laser has a laser diode adapted to emit an optical beam that is used to generate data light and reference light with which a hologram recording medium is irradiated. The photodiode detects the amount of the optical beam output from the external cavity laser. The laser drive circuit supplies a current to the external cavity laser. The laser diode controller controls the laser drive circuit to ensure that a value obtained by integrating the detected intensity of the optical beam with respect to time over a predetermined period is equal to predetermined recording energy.
摘要:
A hologram recording and reproducing device controls an optical beam output from an external cavity semiconductor laser to improve a diffraction efficiency. The hologram recording and reproducing device includes an external cavity laser, a photodiode, a laser drive circuit and a laser diode controller. The external cavity laser has a laser diode adapted to emit an optical beam that is used to generate data light and reference light with which a hologram recording medium is irradiated. The photodiode detects the amount of the optical beam output from the external cavity laser. The laser drive circuit supplies a current to the external cavity laser. The laser diode controller controls the laser drive circuit to ensure that a value obtained by integrating the detected intensity of the optical beam with respect to time over a predetermined period is equal to predetermined recording energy.
摘要:
A hologram reproducing apparatus includes a first reference light path leading laser light from a laser light source so that a hologram recording medium is irradiated with first reference light; a diffracted light path leading diffracted light, generated from the hologram recording medium by irradiation with the first reference light, to a light receiving element having a plurality of pixels; and a second reference light path leading second reference light, having the same polarization direction as that of the diffracted light, from the laser light source to the light receiving element. The second reference light path is provided with a phase modulating element so that the phase difference between the diffracted light and the second reference light in a light receiving surface of the light receiving element is adjusted within a predetermined range.
摘要:
A hologram reproducing apparatus includes a first reference light path leading laser light from a laser light source so that a hologram recording medium is irradiated with first reference light; a diffracted light path leading diffracted light, generated from the hologram recording medium by irradiation with the first reference light, to a light receiving element having a plurality of pixels; and a second reference light path leading second reference light, having the same polarization direction as that of the diffracted light, from the laser light source to the light receiving element. The second reference light path is provided with a phase modulating element so that the phase difference between the diffracted light and the second reference light in a light receiving surface of the light receiving element is adjusted within a predetermined range.
摘要:
A drive apparatus includes a light irradiation section for applying light from a light source via an object lens on a hologram recording medium having a recording layer on which a hologram is formed and a track formation layer on which an address recording track composed of a pit string recording address information representing the hologram recording position on the recording layer and an auxiliary track composed of a continuous groove formed side by side with the address recording track are formed, a light spot displacement section for displacing a light spot formed by the light irradiation section in a radius direction of the hologram recording medium, and a control section for controlling the light spot displacement section following a light information signal upon the auxiliary track traverse of the light spot obtained in accordance with the light spot displacement to execute a jump operation between the address recording tracks.
摘要:
A hologram recording device can easily perform multiplex recording/reproduction on a hologram recording medium. The hologram recording device includes an optical system and a distance controlling mechanism. The optical system focuses on a substantially same location of a hologram recording medium a signal light modulated at a light modulating element and a reference light whose phase has been modulated at a phase modulating element. The distance controlling mechanism controls a distance between the phase modulating element and the hologram recording medium. By controlling the distance between the phase modulating element and the hologram recording medium, multiplex recording can be performed on the hologram recording medium. In an ordinary phase-correlation multiplexing method, multiplex recording is performed as a result of shifting a light-focusing location in the direction of a surface of the hologram recording medium, whereas, in the present invention, it is possible to perform the multiplex recording without shifting the light-focusing location in the direction of the surface of the hologram recording medium. It is possible to further increase recording capacity as a result of shifting the light-focusing location in the direction of the surface of the hologram recording medium. Here, compared to the ordinary phase-correlation multiplexing method, it is possible to perform shifting by a sufficient amount.
摘要:
A magnetic tape recording/reproducing apparatus having a loading assembly which comprises a rotatable member driven by a motor mounted on the tape deck, a rack member interlocking with a tape pack inserted within said tape deck so as to be slidable with respect to said tape deck so that said rack member is allowed to slide due to rotational force of said rotatable member.
摘要:
A clutch system in a tape player comprises a first rotor rotated by a motor and a second rotor capable of engaging with and disengaging from said first rotor, both rotors being formed with engage portions at their end faces which are adjacent to each other. The clutch system is further provided with a switching means for carrying out engagement and disengagement of said rotors, and the switching means is operated by an operating means for making said motor carry out automatic loading operation.
摘要:
A power loading/unloading mechanism for tape record/playback apparatus which comprises a gear driven by a motor, a rack member associated with a tape pack inserted; a partly cut-out gear independent of the rack member operation system and interlocked with a cam member for advancing and retreating a head plate; an engaging gear driven by the motor and disposed so as to engage with the partly cut-out gear; a means for keeping the engaging gear from engagement with teeth of the partly cut-out gear; and an engagement operating means for detecting completion of tape pack loading and for putting the engaging gear into mesh with the teeth of the partly cut-out gear.
摘要:
A cassette tape recording/reproducing apparatus which is so adapted that after a cassette is horizontally pushed deep into a pack guide, the pack guide is lowered in a vertical direction to set the cassette in a recording/reproducing position on a bottom plate of the apparatus, which apparatus is characterized in:that an ejecting plate and a slide plate are provided along the pack guide so as to slide in the forward and the backward direction of the apparatus, and a lock plate is provided for locking the ejecting plate and the slide plate in their retired positions, respectively, said lock plate being adapted to lock, at a time, either one of the ejecting plate and the slide plate, preventing the same from moving and allow the other to move forwardly or backwardly;that a power plate is provided also along the pack guide, which plate is movable in the forward and the backward direction of the apparatus, provided with a set spring for normally urging the power plate in the retreating direction, and engageable with the slide plate through a rack-pinion mechanism, and means for releasing the engagement between the slide plate and the power plate when the cassette is ejected is provided;that the slide plate has an ejecting spring for normally urging the slide plate in the advancing direction, the force of which is smaller than that of the set spring provided on the power plate; andthat the ejecting plate is interlocked with a mechanism for lowering or raising the pack guide so that the pack guide is lowered or raised according to the advance or retreat of the ejecting plate.