Tilt detection apparatus, hologram apparatus, tilt correction method for medium, and tilt correction method for hologram medium
AssigneeSanyo Electric Co., Ltd.
InventorKazuya Kogure
Life of this patent
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Abstract
A tilt detection apparatus for a medium comprises a tilt detection beam generator that makes a tilt detection beam incident ion a medium to detect whether the medium is tilted with respect to a reference position; a light reception unit that receives the tilt detection beam that after striking the medium, has come from the medium; and a correction output unit that outputs a signal to correct a tilt of the medium, based on a difference in light reception position on the light reception unit between a position at which the light reception unit receives the tilt detection beam and a position at which the light reception unit is to receive the tilt detection beam when the medium is in the reference position.
Claims13
A tilt detection apparatus comprising:
- a tilt detection beam generator that makes a tilt detection beam incident in a medium to detect whether the medium is tilted with respect to a reference position;
- a light reception unit that receives the tilt detection beam that after striking the medium, has come from the medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- a reference voltage generating unit that outputs a predetermined reference signal having a level corresponding to a level of the position signal output when the medium is in a reference position;
- and
- a calculation unit that calculates a difference between the level of the predetermined reference signal and a level of the position signal output during a process of detecting a tilt of the medium and outputs a difference signal to correct a tilt of the medium based on the difference.
A hologram apparatus which causes a coherent data beam corresponding to data to be recorded and a coherent recording reference beam to strike a hologram medium so as to record the data in the form of a hologram in the hologram medium, the hologram apparatus comprising:
- a tilt detection beam generator that causes a tilt detection beam, incoherent to the data beam and the recording reference beam and to detect whether the hologram medium is tilted with respect to a reference position, to strike the hologram medium;
- a light reception unit that receives the tilt detection beam that after striking the medium, has come from the hologram medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- a reference voltage generating unit that outputs a predetermined reference signal having a level corresponding to a level of the position signal output when the medium is in a reference position;
- a calculation unit that calculates a difference between the level of the predetermined reference signal and a level of the position signal output during a process of detecting a tilt of the medium and outputs a difference signal to correct a tilt of the medium based on the difference;
- and
- a correction driver that corrects position of the hologram medium on the basis of the difference signal from the calculation unit.
A hologram apparatus which causes a coherent reproducing reference beam to strike a hologram medium in which data to be reproduced is recorded as a hologram and reproduces the data based on the reproducing reference beam that has been diffracted by the hologram, the hologram apparatus comprising:
- a tilt detection beam generator that causes a tilt detection beam, incoherent to the reproducing reference beam and to detect whether the hologram medium is tilted with respect to a reference position, to strike the hologram medium;
- a light reception unit that receives the tilt detection beam that after striking the medium, has come from the hologram medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- a reference voltage generating unit that outputs a predetermined reference signal having a level corresponding to a level of the position signal output when the medium is in a reference position;
- and
- a calculation unit that calculates a difference between the level of the predetermined reference signal and a level of the position signal output during a process of detecting a tilt of the medium and outputs a difference signal to correct a tilt of the medium based on the difference;
- and
- a correction driver that corrects position of the hologram medium on the basis of the difference signal from the calculation unit.
A hologram apparatus which causes a coherent data beam corresponding to data to be recorded and a coherent recording reference beam to strike a hologram medium so as to record the data in the form of a hologram in the hologram medium, the hologram apparatus comprising:
- a tilt detection beam generator that causes a tilt detection beam, incoherent to the data beam and the recording reference beam and to detect whether the hologram medium is tilted with respect to a reference position, to strike the hologram medium;
- a light reception unit that receives the tilt detection beam that after striking the medium, has come from the hologram medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- a correction output unit that outputs a difference signal to correct a tilt of the hologram medium, based on a difference between a level of the position signal output from the light reception unit when the medium is in the reference position and a level of the position signal output from the light reception unit during a process in which the data is recorded in the hologram medium;
- a correction driver that corrects position of the hologram medium on the basis of the difference signal from the correction output unit;
- a vibration calculation unit that calculates a vibration amount of at least one of the hologram medium and the tilt detection beam generator based on the difference in light reception position on the light reception unit between a position at which the light reception unit receives the tilt detection beam and a position at which the light reception unit is to receive the tilt detection beam when the hologram medium is in the reference position;
- a vibration determination unit that determines whether the vibration amount calculated by the vibration calculation unit is less than a given vibration amount;
- and
- an interruption unit that cuts off irradiation of at least one of the data beam and the recording reference beam into the hologram medium on the basis of the determination result of the vibration determination unit indicating that the vibration amount calculated by the vibration calculation unit is at the given or greater vibration amount.
A hologram apparatus which causes a coherent reproducing reference beam to strike a hologram medium in which data to be reproduced is recorded as a hologram and reproduces the data based on the reproducing reference beam that has been diffracted by the hologram, the hologram apparatus comprising:
- a tilt detection beam generator that causes a tilt detection beam, incoherent to the reproducing reference beam and to detect whether the hologram medium is tilted with respect to a reference position, to strike the hologram medium;
- a light reception unit that receives the tilt detection beam that after striking the medium, has come from the hologram medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- a correction output unit that outputs a difference signal to correct a tilt of the hologram medium, based on a difference between a level of the position signal output from the light reception unit when the medium is in the reference position and a level of the position signal output from the light reception unit during a process in which the data is reproduced;
- a correction driver that corrects position of the hologram medium on the basis of the difference signal from the correction output unit;
- a vibration calculation unit that calculates a vibration amount of at least one of the hologram medium and the tilt detection beam generator based on the difference in light reception position on the light reception unit between a position at which the light reception unit receives the tilt detection beam and a position at which the light reception unit is to receive the tilt detection beam when the hologram medium is in the reference position;
- a vibration determination unit that determines whether the vibration amount calculated by the vibration calculation unit is less than a given vibration amount;
- and
- an interruption unit that cuts off irradiation of the reproducing reference beam into the hologram medium on the basis of the determination result of the vibration determination unit indicating that the vibration amount calculated by the vibration calculation unit is at the given or greater vibration amount.
A tilt correction method for a medium comprising:
- making a tilt detection beam incident in a medium to detect whether the medium is tilted with respect to a reference position;
- receiving the tilt detection beam that, after striking the medium, has come from the medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- outputting a predetermined reference signal having a level corresponding to a level of the position signal output when the medium is in a reference position;
- calculating a difference between the level of the predetermined reference signal and a level of the position signal output during a process of detecting a tilt of the medium;
- and
- outputting a difference signal to correct a tilt of the medium based on the difference.
A tilt correction method for a hologram medium by a hologram apparatus which causes a coherent data beam corresponding to data to be recorded and a coherent recording reference beam to strike a hologram medium so as to record the data in the form of a hologram in the hologram medium, the method comprising:
- causing a tilt detection beam, incoherent to the data beam and the recording reference beam and to detect whether the hologram medium is tilted with respect to a reference position, to strike the hologram medium;
- receiving the tilt detection beam that, after striking the medium, has come from the hologram medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- outputting a predetermined reference signal having a level corresponding to a level of the position signal output when the medium is in a reference position;
- calculating a difference between the level of the predetermined reference signal and a level of the position signal output during a process of detecting a tilt of the medium;
- outputting a difference signal to correct a tilt of the medium based on the difference;
- and
- correcting position of the hologram medium on the basis of the difference signal.
A tilt correction method for a hologram medium by a hologram apparatus which causes a coherent reproducing reference beam to strike a hologram medium in which data to be reproduced is recorded as a hologram and reproduces the data based on the reproducing reference beam that has been diffracted by the hologram, the method comprising:
- causing a tilt detection beam, incoherent to the reproducing reference beam and to detect whether the hologram medium is tilted with respect to a reference position, to strike the hologram medium;
- receiving the tilt detection beam that after striking the medium, has come from the hologram medium to output a position signal having a level corresponding to a position at which the tilt detection beam is received;
- outputting a predetermined reference signal having a level corresponding to a level of the position signal output when the medium is in a reference position;
- calculating a difference between the level of the predetermined reference signal and a level of the position signal output during a process of detecting a tilt of the medium;
- outputting a difference signal to correct a tilt of the medium based on the difference;
- and
- correcting position of the hologram medium on the basis of the difference signal.
Dependencies are inferred from the claim text.