Abstract: A method of reproducing data from a recording medium, each of the data including reference time information indicating a reference time and including packet data, the method including: reproducing the data from the recording medium; obtaining a difference between respective reference times indicated by the reference time information of the reproduced adjacent data; rearranging the data on a time axis such that a time interval between adjacent data is equal to the obtained reference time difference; and outputting the rearranged data.

Abstract: A device for processing a radio frequency (RF) signal of an optical disk drive includes a high-pass (HP) filter, an RF variable gain amplifier (VGA), an RF analog-digital converter (ADC), and a digital module. The HP filter filters the RF signal and is capable of selectively utilizing one of a first cut-off frequency and a second cut-off frequency. The RF VGA amplifies the filtered RF signal. The RF ADC converts the amplified RF signal into a digital code. The digital module is capable of executing a first function and a second function with the digital code. The HP filter utilizes the first cut-off frequency when the digital module desires to execute the first function, and the HP filter utilizes the second cut-off frequency when the digital module desires to execute the second function.

Abstract: On an optical disk medium according to the present invention, address information is recorded along a wobbling track groove 2. The track groove 2 is made up of a plurality of unit sections 22, 23. Each of these unit sections 22, 23 has side faces that are displaced periodically in a disk radial direction. This displacement oscillates at a single period in a tracking direction. However, the displacement pattern differs depending on “each bit of address information (subdivided information)” allocated to each of the unit sections 22, 23.

Abstract: The present invention provides a magnetooptic device, a magnetooptic head, and a magnetic disk drive each capable of performing optically assisted magnetic recording and each having a small size, improved recording density, and a higher transfer rate. In a magnetooptic device, a magnetic circuit including a magnetic gap and a thin film magnetic transducer having a coil portion are stacked on the surface of a semiconductor laser. By the arrangement, optically assisted magnetic recording can be performed, small size and light weight are achieved, and higher transfer rate can be implemented.

Abstract: A system which calibrates notch filters in a digital servo system is presented. A notch filter can be calibrated by obtaining a frequency response curve of the digital servo system in a range of frequencies, searching the frequency response curve for at least one peak frequency, and adjusting parameters of the notch filter to filter out signals at the at least one peak frequency. The digital servo system, for example, can be a tracking servo system or a focus servo system of an optical disk drive.

Abstract: An optical pickup head (100) for a high density recording and/or reproducing device compatible with first and second optical recording media. The pickup head includes a first light source (11) emitting first light beams with a first wavelength, a second light source (12) emitting second light beams with a second wavelength greater than the first wavelength, a prism unit (3), a collimating lens (4) located beside the prism unit for collimating incident first and second light beams, and an objective lens (7) for receiving the first and second light beams and transmitting the first and second laser beams to the first and second recording media respectively. The prism unit includes a first portion facing the first light source and receiving the first light beams, a second portion facing the second light source and receiving the second light beams, and an aspherical surface for the second light beams to pass therethrough.

Abstract: An optical reproducing device is provided with predetermined length mark signal measurement means which measures amplitude values of a 2T mark and an 8T mark, which are a short reproducing power control mark and a long reproducing power control marks, respectively, from information data recorded in an magneto-optical disk. Reproducing power of a light beam is controlled by a laser power control circuit, based on the amplitude values of the 2T mark and the 8T mark. The predetermined length mark signal measurement means detects a specific pattern including the 2T mark from a bit arrangement pattern of the information data, and measures the amplitude value of the 2T mark correponding only to the 2T mark included in the specific pattern. This structure can provide an optical reproducing device which can maintain the reproducing power at an optimum value and reduce the probability of reading errors, without reducing the utilization ratio of an optical recording medium.

Abstract: An optical pickup has a light source for emitting a plurality of laser beams with different wavelengths; and an objective lens for focusing the laser beams emitted from the light source on recording surfaces of plural types of information recording media. A diffractive lens structure is provided in a light path of the laser beam, the structure including ring zone areas divided by a plurality of phase steps for correcting a wavefront aberration of the laser beam, a diameter of an outermost phase step of the diffractive lens structure is smaller than a second largest effective diameter of effective diameters required for reproduction of the plural types of information recording media.

Abstract: Systems in accordance with the present invention can include a tip contactable with a media, the media including a substrate and a plurality of cells disposed over the substrate, one or more of the cells being electrically isolated from the other of the cells by a material having insulating properties. One or more of the plurality of cells can include a phase change material. The media is either grounded or electrically connected with a voltage source such that when the tip is placed in contact with the media and a voltage is applied to the tip, a current is drawn through the cell over which the tip is arranged. The current is drawn through the isolated cell at least a portion of the phase change material within the cell beneath the tip is heated to a sufficient temperature such that the material become amorphous in structure. The current is then removed from the phase change material, which is quickly cooled to form an amorphous domain having a resistance representing a “1” (or a “0”).

Abstract: A stopper 30 includes a projected portion 35 for restricting movement of a movable section in a focusing direction and a wall section 34 for restricting movement of the movable section in a tracking direction, the projected portion 35 and the wall section 34 being integrally formed from a synthetic resin. With the arrangement, a single stopper 30 can simultaneously restrict the movements of the movable section both in the focusing direction and the tracking direction and determine its movable ranges. Accordingly, unlike conventional arrangements, discrete stoppers for the focusing direction and the tracking direction do not have to be provided, thereby reducing the number of components and cost as well as facilitating mounting operation. In addition, even when a strong impact is applied, the stopper will not be deformed.

Abstract: An apparatus comprises a thin film metallic layer, a first dielectric layer arranged on a first side of said thin film metallic layer and having a first index of refraction, a second dielectric layer arranged on the opposite side of said thin film metallic layer from said first dielectric layer, a third dielectric layer arranged on the first side of the thin film metallic layer adjacent to the first dielectric layer and having a second index of refraction that is lower than the first index of refraction, and wherein the thin film metallic layer, the first dielectric layer and the third dielectric layer are arranged to focus plasmon waves induced at an interface between the thin film metallic layer and the third dielectric layer.

Abstract: In an optical recording method used when information is recorded in a phase-change recording layer of a large-capacity rewritable optical recording medium such as a DVD-RW, one block pulse is used as a recording pulse for forming one recording mark when a recording velocity is higher than a recording linear velocity at which the rewritable optical recording medium can be rewritten, whereas a pulse train comprised of a plurality of short pulses is used as the recording pulse for forming one recording pulse when the recording velocity is within recording linear velocities at which the rewritable optical recording medium can be rewritten, whereby high-velocity recording is realized.

Abstract: A detection signal S1 outputted from a light reception unit (11A) of detection elements (11) formed by four-division light reception element is added to a detection signal S4 outputted from a light reception unit (11D) so as to obtain an addition signal S14 and a phase difference signal P1 indicating the phase difference between the addition signal S14 and the detection signal S1. Furthermore, a phase difference signal P4 indicating the phase difference between the addition signal S14 and the detection signal S4 is obtained. The phase difference signal P4 is subtracted from the phase difference signal P1 so as to generate a tracking error signal TE1.

Abstract: A tilt detection system includes an optical disk having a series of data recorded therein, the series of data having a pulse width smaller than the minimum pulse width of data recorded in an ordinary optical disk; a reproducing part reproducing a signal from the optical disk by emitting a light beam onto the optical disk; and a tilt detecting part detecting a tilt of the light beam with respect to the optical disk based on a reproduced RF signal provided by the reproducing part when the series of data having the smaller pulse width is reproduced.

Abstract: A method of recording and/or reproducing data with respect to an information storage medium that includes a lead-in area, a user data area, and a lead-out area. Information about whether the information storage medium is compatible with a drive following an older version of standards is recorded in at least one of the lead-in and lead-out areas and is used during the recording and/or reproduction of data with respect to the information storage medium. Accordingly, the recording performance thereof is improved, and a drive following an older version of standards can record data on or reproduce data from a newer version of an information storage medium.

Abstract: An optical record carrier (1) is provided with tracks having a groove (4) wobbled in a transverse direction and predetermined positions (18) along the track. The wobble comprises a substantially monotonous undulation (15). Local excursions (16) of the groove superposed on the undulation at the predetermined positions represent position information, such as addresses. The spatial frequency of the undulation is lower than that of the excursions.

Abstract: A system and related methods for characterizing and improving optical drive read performance is presented. The system includes an innovative audio file stored on optical media (characterization file), and an optical drive characterization agent, implemented on a computing system. The optical drive characterization agent iteratively controls the optical drive to perform incremental reads of at least a subset of the characterization file, analyzes at least the subset of the characterization file read from the optical media, and generates one or more performance scores on an associated one or more performance attributes of the optical drive. In this regard, optical drive characterization agent quantifiably characterizes an optical drive's ability to accurately read individual sectors from optical media comprising audio content.

Abstract: The objective of this invention is to provide a type of data processing device and a type of data recording/reproduction device that can restart data write processing correctly from an interruption position after data write processing on a recording medium is interrupted. When write is interrupted, prescribed information that indicates the tail of the data written before said interruption is obtained from the written data. When write is restarted, first, data read processing is started. From the read data, the tail of the write data before said interruption is determined based on said obtained information. Then, data write processing is restarted and connected to said determined tail of the write data. In write clock signal generating part (45), write clock signal CK3 locked to the phase of read clock signal CK2 is generated. Consequently, it is possible to suppress discontinuity in the connection of write in company with switching from read processing to write processing.

Abstract: The multi-wavelength lens for condensing a plurality of kinds of monochromatic light by refraction is disclosed. The lens comprises a common use area for all monochromatic light on at least one lens surface, the area sectioned into a plurality of aspherical zones each of which having a different refractive power; and step portions, each of which formed between adjacent aspherical zones of the plurality of aspherical zones and having a step height Dj (j=1,2,3,4, and so on, in order of closeness to a lens optical axis) in a direction parallel to the lens optical axis. At least half of the step portions satisfy a following formula when a minimum value and a maximum value of Aij for each wavelength ?i are MIN(Aij) and MAX(Aij), respectively: MAX(Aij)/MIN(Aij)<3 where, Aij=absolute(Bij?mij), Bij=(absolute(Dj))*(ni?1)/?i?C, ni is a refractive index of a lens for a wavelength ?i, mij is an integral number closest to Bij, and C is a corrective term.

Abstract: In a rewritable compact disc having a wobble groove on a substrate, crystal and amorphous states of a phase-change recording layer are an unrecorded/erased state and a recorded state, respectively. When the recording layer is exposed to recording light, amorphous marks assuming the recorded state are formed. At any of 2-, 4- and 8-times velocities with respect to a reference velocity (1-times velocity) whose linear velocity is 1.2-1.4 m/s, modulation m11 of a recorded signal when the recording light of approximately 780 nm in wavelength irradiates the recording layer via an optical system with NA=0.5 or 0.55 is 60-80%. A topmost level Rtop of reflectivity of the eye pattern of the recorded signal during retrieving at the 1-times velocity is 15-25%, and a jitter of the individual length of marks and inter-mark spaces during retrieving at 1-times velocity is 35 ns or less.