摘要:
An information reproducing method for an optical recording medium in which grooves and lands are formed on a substrate, information recording areas are formed in association with both a groove and a land, and an address area is formed at the information recording area preceding the groove and the land. First and second address pits are disposed in the address area on an extension of a boundary between the groove and the land and the first and second address pits are disposed to satisfy predetermined requirements.
摘要:
An optical reproducing method for an optical medium including a disk-like substrate having a groove structure along tracks divided into a plurality of units. Each of the units includes a dropout portion of the groove structure along the track which is a non-groove portion. The groove structure is wobbled in a fixed cycle in a radial direction. When the wobble is formed in the circumferential direction of the track, the dropout portion is formed so that a phase of the wobble is continued with a phase of the wobble of the groove structure within another unit adjacent to the dropout portion. The method includes irradiating an optical spot on the optical medium, detecting a reflected beam from the optical medium, and reproducing information on the optical medium by using a signal obtained by the reflected beam.
摘要:
An optical reproducing method for an optical medium including a disk-like substrate, a spiral or concentric-shaped groove structure along a track formed on the disk-like substrate, the groove structure being wobbled in a radial direction of the optical medium, the track being divided into a plurality of units in the track direction by at least one radial boundary line, at least two adjacent units in the radial direction of the optical medium comprise one zone, and the groove structure included in the respective units within one zone having substantially a same number of wobbling. The method includes irradiating an optical spot on the optical medium, detecting a reflected beam from the optical medium, and reproducing information on the optical medium by sing a signal obtained by the reflected beam.
摘要:
An optical disk recording medium including a substrate in the form of a substantially circular disk. Grooves and lands are alternately formed on the substrate in a radial direction with the grooves and lands both serving as recording tracks. The recording tracks are divided into recording units in the circumferential direction with each recording unit having a prepit area in a non-groove portion of the substrate. Plural pairs of first and second prepit portions are provided in the prepit area of each recording unit with first prepit portion being represented as VFO information and the second prepit portion being represented as address information. Both of the VFO information and the address information are formed on one side of a center line of one track so as to be shared with an adjacent track adjacent the one side of the center line of the one track, and every information including both of the VFO information and the address information do not exist at opposing positions on both sides of the center line of the one track.
摘要:
An information recording medium having spiral or concentric tracks with a plurality of grooves and lands formed on a disk-like substrate. Each of the tracks is divided into a plurality of recording units and each of the recording units includes a blank portion in a circumferential direction of the track. The track is formed with a wobble in a radial direction and each of the recording units has a length which is an integer multiple of a cycle of the wobble.
摘要:
An optical recording/reproducing method and apparatus using an optical recording medium in which grooves and lands are formed on a substrate, information recording areas are formed in association with both the groove and land, and having a flat address area. First and second address pits are disposed in the address area and satisfy predetermined requirements. An optical spot is irradiated on the optical recording medium and a reflected beam from the optical recording medium is detected which includes detection of an address pit so as to form an address pit readout signal. An address is detected on the basis of the address pit readout signal, wherein an amplitude of a first readout signal obtained from the first address pit is sampled and held and compared with an amplitude of a second readout signal obtained from the second address pit, which is sampled and held. The irradiation position of the optical spot is controlled in accordance with a result of the comparison.
摘要:
Because a series of data is recorded continuously, the recording quality of data recorded in course of recording cannot be evaluated. Accordingly, the laser output cannot be controlled properly and there are a deterioration and dispersion of the recording quality. Further, when the recording lasts for a long time, the temperature in the vicinity of laser rises due to the heat from the inside of a disc drive and the recording quality is deteriorated.To solve this, a series of data to be recorded is split and recording is made intermittently in a split data unit. The recording quality is evaluated by reproducing the data recorded nearby before each split data is recorded using a duration and control is performed by reflecting the evaluation result in the laser output so that the recording quality can be maintained satisfactorily over a series of the whole data to be recorded. Further, control is performed so that good recording quality can be maintained even in the recording that lasts for a long time by stopping the function of each part that ought to be operated even at recording or reproduction inside the disc drive in the duration, thereby suppressing a temperature rise.
摘要:
An optical disk device having a light source for emitting light, focusing optics for radiating and focusing the light onto an optical recording medium, a photo-detection system for photoelectrically transforming reflected light from the optical recording medium, a reproduction circuit for reproducing information recorded on the optical recording medium by using an electric signal from the photo-detection system, phase control optics for changing the phase of the reflected light, a readout control circuit for controlling the quantity of the phase change of the phase control optics, and a learning control circuit for calculating the optimum value of the phase change quantity by monitoring the output signal of the reproduction circuit while changing the quantity of the phase change by the readout control circuit. Thus, information can be reproduced from a recording medium having high recording density without crosstalk.
摘要:
An information recording medium includes an information recording layer on which at least information is to be recorded by irradiating light, and a light transmission restricting layer which has a plurality of nonlinear transmission characteristics or nonlinear reflection characteristics for the intensity of the light irradiated and which has an optical material for restricting the transmission or reflection of the light according to the respective characteristics when the light is irradiated onto the information recording layer. An information recording and reproducing unit uses the information recording medium and includes an information recording position setting unit for deciding a position at which information is to be recorded on the information recording medium by detecting a direction of an easy magnetization axis. With the above arrangement, the spot diameter of the light can be distinguished between the one when information is reproduced and the one when information is recorded on the information recording medium respectively, to thereby ensure an accurate positioning of the head on the tracks of the recording medium.
摘要:
A method and apparatus are disclosed which place a glass blank on a lower mold arranged in an opposed relation to an upper mold, heat these molds and glass blank by an infrared lamp unit or high-frequency coil arranged around the molds and press-mold an optical glass element. In the method and apparatus, the infrared lamp unit or high-frequency coil is supported by a supporting mechanism such that it is movable along a direction in which the mold is moved. In cases where a relative position of the infrared lamp unit or high-frequency coil to the mold varies depending upon the shape and size of such molds or the shape and size of optical glass elements obtained, the infrared lamp or high-frequency coil is adjustably moved relative to the mold by a movable mechanism using a motor or air cylinder as an operation source. By using temperature sensors attached to both the molds, the temperatures of the upper and lower molds are controlled to a corresponding desired level.