Abstract: A laser power control system and related method for reducing a settling time in a target laser power transition are disclosed. The laser power control system includes a state decision circuit, for generating a state decision signal according to a selected operational state of a target circuit; a plurality of buffers, for storing a plurality of control data corresponding to a plurality of candidate operational states of the target circuit respectively; and a multiplexer, coupled between the state decision circuit and the buffers, for coupling a selected buffer of the buffers and the target circuit according to the state decision signal for outputting a control datum stored in the selected buffer to the target circuit.

Abstract: In an optical scanning device (10) capable of scanning an information plane of an optical record carrier (5) of different types such as BD, DVD and CD, the diameter of the radiation spot on the detector (7) is dependent on the numerical aperture of the objective system (4) that is used for scanning the record carrier An optimal design of the optical detection system for scanning a BD, result in a small radiation spot for the other types such as DVD and CD.

Abstract: An optical pickup according to the present invention includes an integrated circuit element (LDD) 5 for driving first, second, and third semiconductor lasers 3, 4, and 5. The LDD 50 is shaped so as to have a rectangular principal face surrounded by one side, with a plurality of input/output pins being arranged along each side. The plurality of input/output pins include a first pin group connected to a blue-violet laser 5 whose oscillation wavelength is the shortest, a second pin group connected to a red laser 4, and a third pin group connected to an infrared laser 3. The wiring structure of the optical pickup includes a first transmission line 41 for connecting the first pin group to the blue-violet laser 5, a second transmission line 33 for connecting the second pin group to the red laser 4, and a third transmission line 31 for connecting the third pin group to the infrared laser 3, where the first transmission line 41 is shorter than both the second and third transmission lines 31 and 33.

Abstract: A method for designing an optical pickup is provided. The optical pick includes a monolithic laser diode that emits a laser light beam for DVD recording and a laser light beam for CD playback, two photodetective portions, and an objective lens, for each of the emitting portions of the monolithic laser diode for emitting the DVD recording and CD playback laser light beams respectively, the specification of the error of the emission direction thereof is determined according to the following formula: |(???1×??1×Dpd1/Dob1????2×??2×Dpd2/Dob2)×Kpd2|??, where, “1” corresponds to the DVD recording laser light beam and “2” corresponds to the CD playback laser light beam, ??? represents the emission angle; ?? represents the sensitivity; Dob represents the diameter of the light beam; Dpd represents the diameter of the spot formed by the light beam; Kpd represents the sensitivity; and ? represents the tolerable value.

Abstract: An optical disk apparatus includes an optical pickup and a disk-rotation driving unit configured to rotationally drive the optical disks. The optical pickup includes a first emission unit configured to emit a first wavelength beam; a second emission unit configured to emit a second wavelength beam; a third emission unit configured to emit a third wavelength beam; an objective lens configured to focus the first to third wavelength beams emitted from the first to third emission units, respectively, at a signal recording surface of an optical disk; a light-path combining unit configured to combine an optical path of the first wavelength beam emitted from the first emission unit and an optical path of the second and third wavelength beams emitted from the second and third emission units, respectively; and an aberration correcting unit provided on the optical path of the second and third wavelength beams.

Abstract: A small form factor optical disk drive is provided. An OPU is mounted on a sled such that an optical path length to the optical media falls substantially between coherence function maxima.

Abstract: A device for reading from or writing to optical recording media having an optical assembly and a laser diode coupled thereto is described. The laser diode is a twin laser diode which is coupled to the optical assembly by means of a translationally displaceable rotary joint.

Abstract: An optical head device may include a frame type of laser beam emitting element provided with a heat radiating fin on which a laser chip is mounted, a device frame on which the laser beam emitting element, a light receiving element and an optical system are mounted, and a heat radiation member formed of material having a superior heat conduction property. The upper face of the laser beam emitting element is fixed to the device frame, and an under face of the heat radiating fin which corresponds to a portion where the laser chip is mounted is exposed on an outer side to form an exposed part, and the heat radiation member is disposed to extend over the exposed part and the device frame.

Abstract: An apparatus for reading from an optical recording medium, and more specifically to an apparatus suitable for reading from an optical recording medium having a high data density is proposed. The apparatus has: a light source for generating a first light beam; means for generating a second light beam, which has a different wavelength than the first light beam; one or more focusing means for focusing the first light beam and the second light beam onto the optical recording medium to form a first light spot and a second light spot, wherein the second light spot is larger than the first light spot and physically and/or virtually encompasses the first light spot; one or more detectors for detecting a first light beam and a second light beam reflected by the optical recording medium; and means for generating a data signal from the difference between the detected first and second reflected light beams.

Abstract: An optical system and pick-up device having an optical magnification suitable for three different optical disc formats and a light emitting means for emitting a laser beam having a wavelength corresponding to each disc in the optical system of the optical pickup for recording and/or reproducing an information signal to the optical discs. The optical pickup device has a first light emitting unit for emitting a laser beam having a first wavelength or a second wavelength, a second light emitting unit for emitting a laser beam having a third wavelength, a first collimator lens for transmitting the laser beams having the first or second wavelengths, a second collimator lens for transmitting the laser beam having the third wavelength, a first objective lens for transmitting the laser beams having the first or third wavelengths, and a second objective lens for transmitting the laser beam having the second wavelength.

Abstract: An optical pickup apparatus and an optical disc apparatus are adapted to raise the efficiency of utilization of the lasers of the apparatus for accurately detecting tracking errors by raising the intensity ratio of the beam of the 0-th order to the beams of the ±1st orders produced by splitting of the laser beam of the wavelength to be subjected to division by three. The optical pickup apparatus includes a light emitting section for emitting a first laser beam having wavelength ?1 and a second laser beam having wavelength ?2 different from the wavelength ?1.

Abstract: An optical pickup unit comprising: a circuit connected to a light emitting device emitting light; and a counterpart circuit connected to the circuit, the circuit being soldered to the counterpart circuit.

Abstract: To provide an optical head to produce good servo and read signals by reducing the influence of interference by light reflected from a non-read layer of a multilayer optical disc. The head includes: a first optical system for converging light from a light source on a first or second storage layer; a second optical system for receiving and transmitting light reflected from the first layer and stray light reflected from the second layer when the light is converged on the first layer; a photodetector; and a calculator. The photosensitive areas of the photodetector output signals representing intensities of the light incident there through the second system. The reflected and stray light incident on the second system interfere with each other, and the first and second groups of areas are arranged so as to be equally affected by a variation in intensity caused by the interference.

Abstract: A laser driving circuit employing a recording compensation circuit configured to generate a light emission timing of a laser on the basis of recorded data and a recording clock signal which are supplied to the recording compensation circuit includes: a phase synchronization circuit; a skew determination circuit; and a data latching circuit.

Abstract: Disclosed is an optical recording method. The optical recording method includes irradiating an area where a recording mark is formed in a medium with a pulse train of laser light, and irradiating the area where the recording mark is formed with continuous-wave laser light that is continuously output.

Abstract: An operating current modifying device is provided for a power generating element. The power generating element generates an output power when the operating current is larger than a threshold current in the power generating element. A functional relationship is between the threshold current and the temperature of the electrical device. The operating current modifying device includes a threshold current modifying module, a power modifying module, a current compensating module, and a power control module. The threshold current modifying module receives a temperature signal from the power generating element to output a threshold current modifying signal according to the temperature signal and the functional relationship. The power modifying module receives a power feedback signal from the power generating element and a target power signal to output an operating current modifying signal.

Abstract: An optical-pickup apparatus comprising: a polarization beam splitter fixed to a base, which includes a first prism that laser light emitted from a laser diode enters, a second prism that return light of the laser light reflected from a signal recording layer of an optical disc enters, and a control film that is formed on either one of opposed surfaces of the first and second prisms so that the laser light and the return light are selectively passed through or reflected from the control film, the opposed surfaces being opposed to each other; and first and second positioning pins provided on the base to position the polarization beam splitter, the polarization beam splitter being fixed to the base in a state where the opposed surface of at least one of the first and second prisms is made in contact with at least one of the first and second positioning pins.

Abstract: Each of control powers of a first definition group that correspond to a pulse train used to form a recording mark, and a plurality of levels of a second definition group that includes each of the control powers of the first definition group in accordance with the conditions of a recording medium 3 are set. A plurality of control powers are selected from the first definition group included in the selected level of the second definition group. When the laser is driven with the corresponding drive values, a monitor 4 obtains an emission power detection value. The emission power detection value is stored for each level of the second definition group, and an occurrence is counted for each level of the second definition group in a period during which the emission power detection value is obtained.

Abstract: To provide an optical head and an optical disc device, in which a cover member for radiating and protecting the optical head and a laser light source are of a simple construction, manufacturing efficiency can be increased, and accuracy variation due to assembly of the laser light source such as an optical axis or the like of a laser beam can be suppressed. Therefore, a boss formed on a light source installation portion of a base is engaged with a boss hole formed on a laser light source supporting portion of the cover member, thereby positioning the cover member on the base. In doing so, an internal thread hole formed on the bottom surface of the base is overlapped with a thread hole formed on a cover portion of the cover member. In this state, a bolt is passed through the thread hole to screw in the internal thread hole.

Abstract: An information handling system optical medium disc is labeled by removing portions of disc's polycarbonate material from the non-storage side of the disc to form an image. Formed images define a label in various forms including letters, Braille, dot-matrix holes or bas-relief. Another material fills in the removed polycarbonate to reinforce the image with visual effects, such as raising the image or providing color to the image, and to maintain the balance of the disc for rotation in an optical disc drive.

Abstract: Provided is an optical pickup device capable to suppress an occurrence of an aberration on a recording medium and a decrease of power of laser beams while employing a diffraction grating as an optical axis correction element. The laser element emitting the laser beam for CD (780 nm in wavelength) is disposed between the laser element emitting the laser beam for next-generation DVD (405 nm in wavelength) and the laser element emitting the laser beam for DVD (650 nm in wavelength). Only the laser beam for DVD is aligned by a diffraction effect of the optical axis correction element (diffraction grating) with the optical axis of the laser beam for next generation DVD. It is possible that a decrease of laser power due to diffraction efficiency is suppressed as much as possible because only the optical axis of the laser beam for DVD is aligned with the optical axis of the laser beam for next-generation DVD.

Abstract: An indirect semiconductor laser having an indirect semiconductor used as the material of an active layer is used, instead of a conventional direct semiconductor laser so as to obtain a reproducing optical source, in order to reduce optical interference noise of the laser caused in the optical head in an optical disc apparatus, and to eliminate the necessity of high frequency wave convolution, thereby it is possible to reduce the cost.

Abstract: An electron beam recording apparatus provided with control means for forming a latent image in a resist layer on a disk substrate corresponding to a predetermined pattern by controlling the irradiation position of an electron beam irradiation unit on the surface of the resist layer in accordance with the rotation angle of the disk substrate by a rotational drive unit, the shift position by a shift drive unit and the recording data that represent the predetermined pattern, and beam-adjusting means for irradiating an electron beam so as to spread over a plurality of tracks in the direction of traversing the tracks in response to the irradiation position control due to the control means, and an electron beam recording method using the apparatus.

Abstract: Disclosed herewith is a data recording and reading equipment capable of reducing laser noise easily. At first, a laser beam source that can reduce the laser noise when reading data from a subject optical disk is obtained. A modulator capable of varying laser attenuation with a voltage is disposed so as to precede the laser, thereby the laser noise when reading data from the optical disk can be reduced without lowering the laser power when in writing.

Abstract: An optical disc drive includes a light source and an objective optical system for condensing a light from the light source onto a recording surface of an optical disc. A chassis which is movable radially of the optical disc supports both the light source and the objective optical system. The light source includes a red/infrared unit having a red/infrared LD and a blue LD. The red/infrared LD generates both a red beam and an infrared beam. The blue LD generates a blue beam. The objective optical system includes a first and a second object lenses whose focal distances are different. The first and the second object lenses are disposed on a circumferential line of the optical disc.

Abstract: Four types of optical systems, a polarization optical system including an objective lens having a high numerical aperture, a polarization optical system including an objective lens having a low numerical aperture, a non-polarization optical system including an objective lens having a high numerical aperture and a non-polarization optical system including an objective lens having a low numerical aperture, are selectively used at the time of irradiating light from a semiconductor laser on a target disk for measurement, and the in-plane birefringence characteristic and perpendicular birefringence characteristic of the target disk are separately acquired based on the amounts of received light obtained by measuring reflected light from the target disk by a photosensor.

Abstract: An optical disc drive apparatus includes a laser device for generating a light beam for optically reading data from a disc. The laser device is electrically incorporated in a resonant circuit which includes an inductance coupled to the laser device.

Abstract: An optical reading method which suppresses variations in the reading quality of a low-reflection optical recording medium. The optical reading method is to read information from an optical recording medium by irradiating the medium with read laser light having a wavelength ? of 400 to 410 nm. In this method, an information recording layer of the optical recording medium is irradiated with the read laser light with an average read power Pra in excess of 1.2 mW if the information recording layer has a reflectance of 4% or less.

Abstract: A semiconductor laser device has a cathode grounded and an anode connected to a collector of a transistor. The transistor has an emitter grounded and a base connected to a first external terminal via a first resistor. A digital transistor has a collector connected to the base of the transistor, an emitter grounded, and a base connected to a second external terminal via a resistor. When a voltage equal to or higher than the predetermined first voltage is applied to the base of the transistor, the transistor is put into a conducting state, and the semiconductor laser device is grounded via the transistor and thereby protected from static electricity and leak current.

Abstract: Provided is an optical pickup device in which the deterioration of optical characteristics of a laser light beam due to a deviation of an optical axis can be smoothly suppressed with a simple structure. An objective lens becomes a finite system for only a laser light beam for CD (780 nm in wavelength). A three-wavelength laser is disposed such that an optical axis of the laser light beam for CD is aligned with an optical axis of an optical system including a polarization BS to an optical axis correcting element. In this case, the large deterioration of the optical properties of the laser light beam for CD, which cannot be sufficiently compensated even if the objective lens is tilted, does not occur. A stable recording and reproducing operation using the laser light beam for CD can be performed.

Abstract: An operating current modifying device is provided for a power generating element. The power generating element generates an output power when the operating current is larger than a threshold current in the power generating element. A functional relationship exists between the threshold current and the temperature of the electrical device. The operating current modifying device may include a threshold current modifying module, a power modifying module, a current compensating module, and a power control module.

Abstract: Disclosed herewith is a data recording and reading equipment capable of reducing laser noise easily. At first, a laser beam source that can reduce the laser noise when reading data from a subject optical disk is obtained. A modulator capable of varying laser attenuation with a voltage is disposed so as to precede the laser, thereby the laser noise when reading data from the optical disk can be reduced without lowering the laser power when in writing.

Abstract: There is provided an objective optical system for an optical information recording/reproducing device. The objective optical system includes an optical element having an annular zone structure on at least one surface. The annular zone structure includes annular zones configured to have at least one step formed, at a boundary between adjacent ones of the annular zones, to extend in a direction of an optical axis. The at least one step is provided to cause a predetermined optical path length difference between a light beam passing through an outside of the boundary and a light beam passing through an inside of the boundary. The predetermined optical path length difference given to a first light beam by the at least one step is approximately equal to an odd multiple of a first wavelength ?a. Abbe number of material of the optical element satisfies a condition of 15<?d<35.

Abstract: An indirect semiconductor laser having an indirect semiconductor used as the material of an active layer is used, instead of a conventional direct semiconductor laser so as to obtain a reproducing optical source, in order to reduce optical interference noise of the laser caused in the optical head in an optical disc apparatus, and to eliminate the necessity of high frequency wave convolution, thereby it is possible to reduce the cost.

Abstract: A light source unit comprises a plurality of light sources emitting a plurality of light beams. A plurality of volume hologram elements are provided for the plurality of light sources respectively, each volume hologram element having a plane of incidence of an incoming light beam and a plane of outgoing radiation of a diffracted light beam which are perpendicular to each other, the plurality of volume hologram elements having mutually different Bragg conditions in which an optical intensity of a diffracted light beam is set to a maximum.

Abstract: An optical pickup device which can more improve heat radiation efficiency and an optical disk apparatus including the optical pickup device are provided. The optical pickup device having a base (110), a laser unit (141), an optical system (140) which propagates a laser beam, and an adjusting member (142) includes a heat radiation part (146) which is fixed to a heat radiation surface (141b) of the laser unit and which conducts heat from the heat radiation surface to the adjusting member. Therefore, heat generated by the laser unit is transmitted to the adjusting member and then the base through the heat radiation part to make it possible to efficiently perform heat removal for the laser unit.

Abstract: A hybrid objective lens has a refractive lens and a diffractive optical element constructed by plural coaxial ring-shaped zones on at least one optical surface thereof. When n1, n2 and n3 each is a diffraction order of a diffracted ray having a maximum light amount among diffracted rays of each of first, second and third light flux having wavelength ?1, ?2 and ?3 when respective light flux comes to be incident into the diffractive structure respectively, the following formulas are satisfied: |n1|>|n2|, and |n1>|n3 |, and the hybrid objective lens converges a n1-th, n2-th and N3-th order diffracted ray of the first, second and third light flux onto an information recording plane of each of the first, second ant third optical information recording medium respectively so as to form an appropriate wavefront within respective prescribed necessary image side numerical apertures.

Abstract: A recording medium (100) is provided with: an element layer including a semiconductor element (110) and an emission element (130), which emits light on the basis of an instruction from the semiconductor element; and a recording layer (120) in which readable predetermined data is recorded by irradiating a light beam.

Abstract: In fabricating a monochromic and highly coherent light source, no single crystalline bulk semiconductor is used, but two different kinds of transparent substances are alternately stacked over each other to constitute a periodic structure in ½ of the intended wavelength. At least one of the two kinds of transparent substances is controllable in electric conductivity, and the structure is such that inside a medium consisting of this kind of transparent substance light-emitting semiconductor particulates are embedded. Accordingly, a light-emitting device has this structure, which makes possible control of the center wavelength of light emission, the width of wavelength distribution and coherence by adjusting the geometrical parameters of the device without having to alter the kind of material use.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.

Abstract: According to one embodiment, an optical disc apparatus includes a laser diode configured to irradiate a laser beam onto an optical disc, a laser drive circuit configured to supply the laser diode with a laser drive current superposed with a high frequency electric current according to defined conditions of the high frequency electric current in order to turn the laser beam output from the laser diode to a multimode laser beam, a detecting section configured to detect a frequency condition of the high frequency electric current to reduce a quantity of interlayer crosstalk, and a setting section configured to set the detected condition in the laser drive circuit.

Abstract: A slim optical pickup in which a leaf spring is combined with an upper surface of a semiconductor substrate, which is a silicon optical bench (SiOB) monolithically manufactured with a photodetector. The slim optical pickup has a substrate including a light source for generating a light beam, an optical element to irradiate light to an optical disc, a photodetector for receiving a light beam reflected by the optical disc, and a plurality of first bonding pads; a heat sink attached to the surface of the substrate; and a supporting means having a plurality of second bonding pads formed on an inner side of an array of the plurality of the first bonding pads on the substrate.

Abstract: The hologram (20) for spherical aberration correction is formed in optical element (10). With respect to the first laser light which requires the largest effective diameter, the hologram does not have effect on wavefront. With respect to the second laser light which requires the second largest effective diameter, the spherical aberration is corrected by the holograms (21, 22) which are formed in a concentric and zonal pattern and construct the hologram, and the effective diameter is converged. With respect to the third laser light which requires the smallest effective diameter, only the hologram (22) has the effect of the correction for the spherical aberration.

Abstract: An optical pickup device includes a pickup base, an optical system, a light emitting element, and a heat transfer holder which transfers the heat of the light emitting element to the pickup base. The heat transfer holder includes a holder base and a holder main body overlapped to the holder base. The holder base is arranged around the light emitting element and has a first flat contact surface which comes into surface contact with an abutment surface of the pickup base, and a second spherical contact surface, which is positioned opposite to the first contact surface. The holder main body has a third spherical contact surface which comes into surface contact with the second contact surface of the holder base, and an engaging recess formed in the third contact surface and having an inner surface which contacts with the light emitting element.

Abstract: A heat source having a device emitting heat, a case protecting and supporting the device, and a thermoelectric element absorbing the heat emitted from the device and dissipating the heat to an outside.

Abstract: An optical pick-up and a disc apparatus having the same to overcome an inferiority of a tracking signal caused by an adjacent layer during the recording and/or reproducing of data an optical disc with multiple recording layers are provided, the optical pick-up including: a light source to emit a light with a predetermined wavelength corresponding to a type of the optical disc; a light collecting unit to focus the emitted light to form a light spot on a signal recording layer of the optical disc, wherein the signal recording layer reflects the light as a signal light and an adjacent layer of the optical disc reflects the light as a noise light; a photodetector to detect a signal by receiving the signal light; and an optical member to intercept the noise light in order to decrease an intensity of the noise light entering the photodetector.

Abstract: An optical pickup projects laser beams having the first to the third wavelengths, in response to the type of a recording medium which is an object to which recording or reproduction is to be performed, and reflecting light from the recording medium is received by a light-detecting element. In order to reduce the sizes of the optical pickup, light of the second and the third wavelengths is generated by a single dual-wavelength light source, and reflecting light of all the wavelengths is to be received by the single light-detecting element. A hologram element giving different optical effects to light of each wavelength is arranged between the light irradiating means and the light-detecting element. Thus, appropriate information recording and reproduction can be performed by using light of each wavelength.

Abstract: It is an object of the present invention to record to and reproduce different types of optical disks using light beams with different wavelengths. In an optical head device for recording to and reproducing high-density optical disks using an objective lens with a large NA, a sawtooth-shaped hologram is used for recording to and reproducing conventional optical disks such as DVDs. For blue light, a sawtooth height is the light path length 2?, and second-order diffraction light is used. Red light generates first-order diffraction. The hologram is blazed and has convex lens function, and corrects chromatic aberration of the refractive lens.

Abstract: The invention relates to the field of optical information recording. In order to prevent abusive or fraudulent use of storage media, the invention provides a process for intentional degradation of information by application of a laser power below the normal power for reading information recorded in super-resolution on the media. This process relies on the surprising observation that a laser power below the super-resolution read power produces an irreversible degradation of the information recorded. This observation has been made with regard to media composed of a three-layer structure comprising an InSb or GaSb layer between two ZnS/SiO2 layers. Application for protecting sensitive data.

Abstract: An optical pickup device 11 according to the present invention includes: a light source 1 that emits a light beam; a condensing element 5 for condensing the light beam toward an information storage medium 14; and a protruding member 101, which comes closer to the information storage medium 14 than the condensing element 5 does when the condensing element 5 faces the information storage medium 14. The protruding member 101 is shaped so as to gradually protrude toward the information storage medium 14 in a tangential direction 21 of the information storage medium 14 rotating.