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.

Abstract: A polarizing beam splitter for separating an upstream beam from a downstream beam according to the polarization of an incident beam is provided between first and second light sources emitting laser beams at respective wavelength and an objective lens. A phase plate for providing a phase difference to a beam incident on the polarizing beam splitter is provided between the polarizing beam splitter and the light sources. A portion of the laser beam incident on the polarizing beam splitter is reflected by the polarizing beam splitter and caused to be incident on a photo-detecting unit, so as to prevent an unnecessary portion of the laser beam is incident on the photo-detecting unit. According to the invention, the laser beam is used efficiently and the cost of fabricating an optical disk apparatus is reduced by eliminating a need for a gain controlling circuit in the photo-detecting unit.

Abstract: An optical recording medium has a multi-layer structure recording layer portion including plural recording layers provided with tracks for guiding a recording light and being adapted to record data, where recording condition information and recording layer identification information for the recording layers are recorded on the tracks as information signals. Test writing is conducted on a recording layer that is subject to recording to derive a suitable recording condition based on recording condition information that is recorded on the recording layer, and direct recording is conducted according to a direct recording condition.

Abstract: The magnitude (Ga) of an impact applied to a lens holder is constantly monitored based on an output of an impact sensor. When it is determined that Ga exceeds Gth, focus servo is released, and the lens holder is provided with a force to make it move away from a disk. Upon recheck of Ga, when it is determined that Ga is now equal to or less than Gth, the force having been provided to the lens holder is cancelled, and the focus servo is resumed.

Abstract: An information playback apparatus is provided to obtain editing effects using an optical disc in the same sense as an analog record disc is manipulated. An audio editing apparatus for playing back an optical disc such as a CD is provided with a rotatable jog dial, detecting device for detecting the amount of rotation of the jog dial, and sensing device for sensing the presence or absence of a pressing force on the jog dial. When the jog dial is rotated while being depressed with a predetermined pressing force, processing for providing sound effects is performed on the playback data to be played back from the optical disc in response to the amount of rotation detected by the detecting device. It is thereby possible to provide the same feeling of operation as provided by rotating an analog record disc through hand operations to produce playback sounds.

Abstract: An optical pickup for reading information written on an optical disk is equipped with a vertical multi-mode converted laser diode which emits light, means for focusing the emitted light from the laser diode onto the optical disk, and means for receiving reflected light from the optical disk in order to read the information written on the optical disk, wherein the coherent distance of the emitted light from the laser diode is made shorter than the optical path length of the optical pickup.

Abstract: An information storage medium according to an aspect of this invention comprises a rewritable area, the rewritable area comprises a user area to store user data, and a defect management area to store defect management information used to manage defective areas on the rewritable area, the defect management area comprises first and second defect management reserved areas, the first defect management reserved area being used to store the defect management information in an initial state, and the second defect management reserved area being used to store the defect management information which is transited at a predetermined timing.

Abstract: An electron beam recorder includes an electron optical system for irradiating an electron beam on a master of an information recording medium and an electron beam irradiation position detecting unit for detecting an irradiation position of the electron beam in the electron optical system while the electron beam is being irradiated on the master by the electron optical system.

Abstract: First data representing user data and third data use the same error correction codes. The first data has a first error correction block structure and the third data has a second error correction block structure. That is to say, the first data and the third data have their respective error correction block structures proper for them. In particular, the recording density of the third data is made less dense than the recording density of the first data, and the number of correction codes in the first error-correction block is set at a multiple of m whereas the number of correction codes in the second error-correction block is set at n/m times the number of correction codes in the first error-correction block so that a data-piece count in the second error-correction block is also n/m times a data-piece count in the first error-correction block. As a result, it is possible to provide a good technique of recording shipping-time information onto a high-recording-density disc.

Abstract: A header of a nano storing apparatus is disclosed. If some cantilevers of the header are defective, an additional extra cantilever array is substitutively used. The header of a nano storing apparatus including: a cantilevery array including cantilevers each having a probe that is able to read and write information of the ‘n’ number of rows and the ‘m’ number of columns, an X-redundancy cantilever array to be used as a substitute when cantilever probes of a specific row in the cantilever array are defective; a Y-redundancy cantilever array to be used as a substitute when cantilever probes of a specific column in the cantilever array are defective; and a header controller for controlling each part.

Abstract: An optical disc and a method of making the same are provided in which the tracks on the disc are not numbered in strict numeric sequence. For example, a disc may contain only odd or only even numbered tracks, or tracks numbered 11 to 20. This is accomplished by providing invisible tracks in the positions of the tracks missing from the listing. Invisible tracks are of minimal length such that the invisible tracks are counted by a disc playing device, but will seem to a listener to be missing when the device plays the disc.

Abstract: The optical disc drive reads and/or writes data from/on an optical disc having an information storage layer. In an optical disc drive 100, light from a light source 3 is focused by a focusing section 1, and each of the peripheral and non-peripheral part of light reflected by the information storage layer is received by a photodetector 4. Then, for each part of light, the drive 100 generates a focus signal and a light quantity signal, and normalizes the focus signal based on the light quantity signal. As a result, it is possible to generate a spherical aberration signal according to a quantity of spherical aberration produced at the focusing position of the light. Hence, the signal is not affected by defocusing and thus it is possible to precisely detect a spherical aberration caused by an uneven thickness of the disc and to detect a spherical aberration with high accuracy.

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.

Abstract: A PLL clock generator generates an output signal with a frequency N times (where N?1) as high as that of an input signal. The clock generator includes: a frequency divider for dividing the frequency of a clock signal by N so as to output a frequency-divided clock signal; a phase comparator for detecting a phase difference between the input signal and the output signal of the frequency divider so as to output a phase difference signal including information representing the phase difference; a LPF for smoothing the phase difference signal; a VCO for generating the clock signal, of which the frequency is determined by the output of the LPF, and outputting the clock signal to the frequency divider; and a phase shifter for shifting the phase of the output signal of the frequency divider in accordance with the phase difference signal.

Abstract: An information storage medium includes: a plurality of unit audio information to be reproduced independently of each other; aggregate audio information each including one or more of the unit audio information; unit attribute information indicating attributes of the unit audio information included in the aggregate audio information; and aggregate attribute information including the unit attribute information corresponding to the aggregate audio information recorded on the storage medium. By referring to the aggregate attribute information, the attributes of all the unit audio information may be readily and quickly obtained.

Abstract: In an optical disk medium, land recording tracks (1) are coupled by first and second coupling portions (3 and 4) at a particular radial position to form a tilt detecting mark SM.

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.

Abstract: An error correction circuit for determining an error in rotational speed of a recordable disk of a disk drive includes a sinusoidal error calculation portion adapted to generate a true oscillation error signal, and a summation portion adapted to combine the true oscillation error with a spindle error signal to generate a total error signal. The sinusoidal error calculation portion is adapted to generate a new true oscillation error based on the total error signal.

Abstract: A method for formatting a phase-change optical disk, using an apparatus for formatting phase-change optical disk, which apparatus includes (a) a drive control substrate on which a CPU for controlling an optical disk drive, a ROM for storing data, and an interface are mounted, and (b) an optical disk drive, is provided, and the method is carried out conducting power calibration a plurality of times to obtain a plurality of recording powers corresponding to the number of the power calibrations conducted, calculating an average recording power from the plurality of recording powers, multiplying the average recording power by a predetermined coefficient to obtain a recording power for formatting, and formatting a phase-change optical disk in accordance with the recording power for formatting. The phase-change optical disk formatted by this method is also provided.