Abstract: When data recording is performed on an optical disk provided with a data recording track wobbled by a wobble signal having predetermined frequency components, a recording clock generator circuit extracts the wobble signal, generates a divided clock signal obtained by dividing the frequency of a recording clock signal at a frequency dividing rate that is set through predetermined procedures and is different from a reference frequency dividing rate, generates a phase difference signal as a result of a comparison between the phase of the wobble signal and the phase of the divided clock signal, generates a frequency control signal obtained based on the phase difference signal, and then generates a recording clock signal having a frequency controlled in accordance with the frequency control signal.

Abstract: In an optical recording apparatus having an optical pickup, a rotating section is provided for rotating an optical disk which is formed thereon with a guide groove to define a spiral track having a plurality of rounds. The optical pickup has a light source for generating an optical beam and a diffractive grating for diffracting the optical beam to form a main beam and a pair of sub beams opposite with each other relative to the main beam. The optical pickup is operable for irradiating the main beam to the spiral track with accompanying the pair of the sub beams along apposite sides of the spiral track. A servo section operates the optical pickup to enable the main beam to trace the spiral track based on a tracking error signal derived from return lights of the sub beams reflected back from the optical disk. A recording section modulates the main beam for recording of information onto the spiral track while the optical dick is rotated.

Abstract: A method and apparatus for copying/moving data on an optical recording medium is disclosed, in which data moves or copies in one disc using a memory and data transmission to a host is omitted when the data moves or copies in one optical disc. To this end, identification information is assigned to a reserved area of read/write commands generated from the host, thereby displaying data movement status or data copying status. Thus, it is possible to reduce the data transmission time when the data moves or copies in one disc. Furthermore, even if the read/write commands in one file or the whole data to move or copy occur several times, the data transmission time such as the data movement time and the data copying time can be reduced by reducing the number of physical access times of the optical disc for the data reading/writing operation.

Abstract: When a light source of a first wavelength is used, side beams are allowed to occur, whereas side beams are prevented from occurring when a light source of a second wavelength is used, thereby raising the light use efficiency of the second light source. A semiconductor laser device comprises a first light source for emitting a light beam of a first wavelength and a second light source for emitting a light beam of a second wavelength different from the first wavelength. The grading groove of a diffraction grating is so formed that the first-order diffraction efficiency is almost zero for the light beam from the first light source and the first-order diffraction light is emitted for the light beam from the second light source.

Abstract: A method for verifying sectors on an optical disc is provided. The method includes writing user data to unverified sectors of the optical disc and verifying the sectors of the optical disc with the user data. The sectors of the optical disc are verified by reading the user data on the unverified sectors of the optical disc and comparing the user data read from the unverified sectors of the optical disc with user data stored on a system buffer. The sectors of the optical disc are verified to determine whether any one of the unverified sectors having user data is defective. Also, the verifying of the unverified sectors establishes verified sectors having user data. The sectors of the optical disc that have been verified are tracked with a bitmap that is continually updated as the sectors are verified.

Abstract: An information recording medium includes a data area for recording data; and a drive information area for recording at least one piece of drive information. The data area is divided into a plurality of segmented areas in a radial direction of the information recording medium. Each at least one piece of drive information includes a recording and reproduction condition corresponding to at least one of the plurality of segmented areas.

Abstract: A multivalued information recording method in which energy applied to information units on a recording medium is varied to record multivalued information. In accordance with a relationship between the multivalued information in a predetermined information unit and the multivalued information in information units adjacent to the predetermined information unit, the energy applied to the predetermined information unit is decided.

Abstract: In an optical information medium having an information bearing surface having projections and depressions and/or capable of forming recorded marks, a functional layer is added. The information borne on the information bearing surface can be read by using reading light of a wavelength longer than 4NA·PL wherein PL is the minimum size of the projections and depressions or the recorded marks and NA is the numerical aperture of a reading optical system, setting the power of the reading light within such a range that the functional layer does not change its complex index of refraction, and irradiating the reading light to the information bearing surface constructed by the functional layer or to the information bearing surface through the functional layer or to the functional layer through the information bearing surface. The medium enables reading at a high resolution beyond the diffraction limit.

Abstract: A method of mounting an optical device having a step on the surface opposing to a mounting substrate favorably by face-down bonding which enables a decrease in the number of components or integrate additional components on one identical substrate and, accordingly, is useful for reducing the size and the thickness of an optical head using a light source, the method includes the step of making the volume of a solder pattern to the area ratio of each electrode different for every wiring electrode portions upon mounting the electrodes on the substrate for mounting the optical device, in which the optical device having the step can be mounted favorably to the substrate by the control for the height of solder upon melting.

Abstract: The present invention relates to an information recording apparatus, an information recording method, an information recording medium, an information reproducing apparatus and an information reproducing method by which in the case in which the present invention is applied to an optical disk system by, for example, a compact disk or the like and data or the like related to copyright is recorded by partial change of a pit shape or the like, the data can be reproduced with certainty without repeatedly recording the data. According to the present invention, with regard to a defect having a size by which at least main data can be reproduced correctly, 1 bit of sub-data SB is allocated to a pit row or the like having a predetermined length or more such that the sub-data SB can be reproduced correctly.

Abstract: An information recording apparatus controls a recording power to be optimal without using a high-rate sampling circuit even when a recording condition changes. A laser diode emits a light at a first optical amount value and a second optical amount value greater than the first value. The light emitted by the laser diode is irradiated onto an optical disc. A signal level value of the reflected light is detected by a sample hold circuit or a low-pass filter, and one of the outputs of the low-pass filter and the signal hold circuit is selected in accordance with an instruction for selection. The sample hold circuit detects the signal level value of a sampled reflected light. The low-pass filter outputs an average value of the signal level value. A drive current driving the laser diode is adjusted by comparing the signal level values before recording information and after starting information recording.

Abstract: An optical information recording/reproducing device reproduces digital data recorded in a form of interference fringes produced by two coherent beams in a hologram disk, by projecting a coherent beam to the hologram disk and receiving a reproduction signal beam obtained by diffraction by means of a two-dimensional photodetector array. The holographic optical information recording/reproducing device includes a tunable coherent light source that emits the coherent beam, and a control section controls and optimizes a wavelength of the tunable coherent light source according to position information of the reproduction signal beam on the two-dimensional photodetector array.

Abstract: A method and apparatus for reproducing data from an optical disc in which a disc inducing vibration is detected and the speed of the disc is adjusted to an appropriate speed which does not cause vibration. The method includes obtaining the frequency of vibration by subtracting the count value of track traverse pulses at the lowest speed factor from the count value of track traverse pulses at the highest speed factor; and varying the speed factor of reproducing data from the disc based upon a comparison of the obtained frequency of vibration with a predetermined base value.

Abstract: A device for scanning a first and second type of optical record carriers (2; 40) generates a first and a second radiation beam for scanning the first and second type of record carriers, respectively, the first radiation beam having a first numerical aperture larger than the second numerical aperture of the second radiation beam. The device includes a non-periodic phase structure that does not affect the first radiation beam. The phase structure introduces an amount of spherical aberration in the second radiation beam for scanning the second type of record carriers for compensating the difference in spherical aberration required for scanning through the different thickness of the transparent layer (3; 41) of the first and second type of record carriers (2, 40).

Abstract: A bit-accurate optical drive determines an address of a data block stored on a disc (the address being determined from a wobble that is embossed in the disc), and synthesizes header information for the block. When the block is read from the disc, recovered (actual) header information is compared to the synthesized header information to determine a phase difference, if any. Recovered user data is phase-shifted by the phase difference.

Abstract: The invention relates to a record carrier of a disc-like optically inscribable type, having a preformed track in which an auxiliarily signal comprising a sequence of codes is recorded by means of a preformed track modulation. The codes comprise a sequence of address codes (AC) specifying the addresses of the track portions in which said address codes (AC) are recorded and special codes (SC). The special codes (SC) can be distinguished from said address codes (AC) and specify control data for controlling a recording by a recording device. The record carrier is provided with an extended area (XAA) proceeding a program calibration area (PCA), the extended area (XAA) comprising special codes (SC) representing additional control information for controlling a recording.

Abstract: A disc speed control device for use in a disc player and/or recorder having a pick-up for reading/recording data. The device comprises an inner loop which regulates a determined disc rotation speed value received at its input and an outer loop which delivers this speed value depending on a frequency at which data is read by the pick-up. The present invention is particularly useful in multistandard disc drives which need to adjust to different disc speed modes, for example, constant angular velocity, or constant linear velocity.

Abstract: A laser power control method according to the present invention is a method for controlling an output power of a laser 3 which is used for recording information on a recording medium 1. The method comprises steps of: detecting emitted light of the laser by a first detection section 4; obtaining a first driving current of the laser by a first control section 8 based on an output of the first detection section; detecting reflected light or transmitted light from the recording medium by a second detection section 5; and obtaining a second driving current of the laser by a second control section 12 based on an output of the second detection section. The laser is driven based on the first driving current or the second driving current while the first control section and the second control section are operated alternately such that the second control section does not operate when the first control section is operating, and the first control section does not operate when the second control section is operating.

Abstract: According to the method, the focusing servo is activated at the zero-crossing point of a focusing error signal FE immediately after the focusing error signal FE has exceeded the first threshold th1 or has dropped below the second threshold th2. The absolute value of the first threshold th1 and the second threshold th2 is reduced each time a predetermined time t is elapsed until the focusing servo is activated.

Abstract: An information recording/reproducing apparatus of the present invention includes: a light source for emitting a first light beam having a predetermined light power Ppre; a determination section for determining the number of recording layers included in the information recording medium; a light beam transmission adjustment section for adjusting the quantity of the first light beam transmitted therethrough; and a light condensing section for condensing the first light beam on the information recording medium. When the information recording medium has one recording layer, the adjustment section adjusts the predetermined light power Ppre so as to be a first light power P1. When the information recording medium has two recording layers, the adjustment section adjusts the predetermined light power Ppre so as to be a second light power P2. The predetermined light power Ppre, the first light power P1, and the second light power P2 satisfy the relationship of P1<P2?Ppre.