Abstract: An optical pickup for writing information to and/or for reading information from an optical disc having at least two recording layers (dual layer) provided with first and second recording layers can prevent layer crosstalk resulting from disturbing a signal reproduced from the first recording layer by a reflected light beam reflected from the second recording layer during a writing operation for writing information to the first recording layer or a reading operation for reading information from the fist recording layer. An orthogonal polarization region forming component forms an orthogonal polarization region, in which respective directions of polarization of a first light beam focused on and reflected by a first recording layer of an optical disc and a second light beam reflected by a second recording layer of the optical disc are perpendicular to each other, in a region, in which the first and the second light beam overlap each other, on a light-receiving surface of a detector.

Abstract: A high-density recording medium including a first surface and a second surface, the second surface being a light incident surface at a normal mounting condition, a clamping area, an information area including a recording layer provided adjacent to the second surface, a transition area extending between the clamping area and the information area, the transition area being defined from an end position of the clamping area to a beginning of the information area, and a slope being formed in the transition area on the first surface. Further, the slope is formed from the end position of the clamping area to a position placed at least a predetermined distance ahead of the start position of the information area, and a gap as a non-slanted area extends between the information area and a closer end of the slope thereto.

Abstract: An optical scanning device is adapted for scanning a record carrier having an outer face. The optical scanning device comprises a radiation source for generating a radiation beam, and an objective system having an exit face arranged for evanescent coupling of the radiation beam between the exit face and the outer face and for converging the radiation beam to a focus. A gap servo maintains a distance between the exit face and the outer face at a predetermined gap height. The optical scanning device includes a control unit for setting the predetermined gap height at at least two different values.

Abstract: A reading method and a reading device for an optical disk drive, which reads data on a track of an optical disk, receives a host command to read required data, checks cache data, reads cache required data to respond to the command, sets the required data to a target track of the optical disk if no required data exists, calculates moving time for which an optical head is moved from a current position to the target track by way of track jumping and track skipping, respectively, compares the moving time for the track skipping and the track jumping with each other, selects one of the track jumping and the track skipping corresponding to the shorter one of the moving time, moves the optical head to the target track to read the required data and responds to the host command to enhance the reading efficiency.

Abstract: A method and system for formatting of recording media.

Abstract: An objective lens actuator is provided which includes two objective lenses mounted on a movable body, and which is capable of preventing the movable body from coming into contact or collision with a disk and whose thickness becomes thinner. When a light beam is concentrated and focused on a high-density optical disk, D1 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; when a light beam is concentrated and focused on a CD, D2 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; when a light beam is concentrated and focused on a DVD, D3 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; and the following relational expression (1) is satisfied, D1<D2<D3??(1).

Abstract: An optical disc apparatus includes an objective lens that converges a light beam emitted from a light source and irradiates an optical disc having recording marks formed in a uniform recording layer with it, a detection signal generation section that receives a return light beam from the recording mark and generates a detection signal, a servo control signal generation section that generates a servo control signal representing relative displacement between the recording mark and a focus of the light beam from the detection signal and a servo signal correction section that generates a correction servo control signal by connecting peaks or neighborhoods of the peaks of servo control signals, the peaks being produced according to the recording marks.

Abstract: An optical disc apparatus controls a relative position of an optical pickup with respect to a surface of an optical disc medium according to an output signal output from the optical pickup according to information recorded on the optical disc medium to implement servo control for maintaining a state where the information is readable, acquires an evaluation value for information reading accuracy when the servo control is implemented, and calculates a set value of a parameter to be set for the implementation of the servo control based on evaluation values respectively acquired for at least three set values of the parameter while changing the set value of the parameter for the servo control. The optical disc apparatus determines the set value to be set for further acquiring the evaluation value according to the evaluation values acquired for at least two set values of the parameter.

Abstract: An optical pickup actuator, including a lens holder movably installed on a base, and mounted with an objective lens to transmit an incident light to an optical information recording medium, and a magnetic circuit to independently drive the lens holder in a focusing direction, a tilting direction and a tracking direction, respectively.

Abstract: The invention provides an optical disk drive. The optical disk drive comprises a pickup head, a seek control device, a lens vision characteristic decoder, and an anti lens shift device. The pickup head comprises a sled and a lens for projecting a beam on a disk. The seek control device moves the sled, and shifts the lens with a shift distance relative to an origin at a center of the sled. The equalizer derives a servo signal from a reflection of the beam. The lens vision characteristic decoder obtains a vision characteristic of the lens according to the servo signal and determines a track-on direction according to the vision characteristic. The anti lens shift device triggers the seek control device to perform a track-on process according to the track-on direction.

Abstract: A servo control device that is capable of optimizing gain that is used in servo control and stabilizing the servo control even when the gain changes due to change in the status of overrecording over the same radial position on an optical disc. When drawing a visible image on the label surface of an optical disc DK by an overrecording operation over the same radial position of that label surface, the servo control device comprises a CPU 8 that changes the gain used in the servo control to correspond with the number of times that overrecording is performed over the same position on that label surface.

Abstract: Disclosed is a method and apparatus for controlling the record and reproduction of optical record medium in which plural nonrecord regions having different phase are arranged between recordable data regions for the distinction in the shape of the data region. The method and apparatus performs the servo using focus error signal and tracking error signal averaged by the low pass filter at the header region of the optical disc. Especially, the tracking servo is performed by holding a fixed DC off-set value at the header region existing on the L/G switching or holding the tracking error value of the previous same track region. As a result, the exact header region is detected, the track sliding phenomenon is removed, and the tracking servo is stabilized, resulting in preventing the degeneration of the record and reproduction characteristics.

Abstract: The soldered connection of an end portion of a cable extending from each element with a main substrate is prevented from being broken. An end portion of a cable t1 extending from a light source element LD that is fixed to a standing frame 2A on a slide base 2 movable back-and-forth in the radial direction of a disk passes through an insertion opening 9 in the slide base 2 to be connected by soldering 8b to a main substrate 3, and an extended portion 15 extending from the peripheral edge of the insertion opening 9 close to the main substrate 3 is formed integrally with the slide base 2, the clearance “?” between the leading end face 15A of the extended portion 15 and the main substrate 3 being set slightly greater than the thickness “d” of the cable t1, so that the cable t1, if tensioned when positioning the light source element LD, is brought into contact with the edge 15a of the leading end face 15A.

Abstract: The present invention relates to a phase retardation plate including a thin organic film with a phase retardation function due to birefringence and a fixed substrate bonded to at least one surface of the thin organic film using an adhesive, and to an optical pickup device having the phase retardation plate. In the phase retardation plate and the optical pickup device using the same, a liner thermal expansion coefficient (L1) of the thin organic film, a liner thermal expansion coefficient (L2) of the adhesive and a liner thermal expansion coefficient (L3) of the fixed substrate satisfy a relationship of L1>L2>L3; and the thin organic film retards the phase of incident light with a wavelength in a range of 400 to 800 nm by ?/2 or ?, the thin organic film having a phase retardation value between 0 and ?.

Abstract: According to one embodiment, an optical disc apparatus includes track error signal generation module for generating, on the basis of a detection result by a light detection module, a second track error signal which is used for tracking control, wherein the track error signal generation module includes module for extracting low-frequency components of signals which are detected by light-receiving units of the light detection module and performing a subtraction between the low-frequency components, thereby generating a first track error signal, extraction module for extracting high-frequency components of the signals which are detected by the light-receiving units detection module for detecting envelope signals of the high-frequency components, module for generating a compensation signal by performing an addition of the envelope signals or a subtraction between the envelope signals, and compensation module for compensating the first track error signal by using the compensation signal thereby generating the seco

Abstract: The present invention discloses an apparatus for generating a tracking error signal in an optical disc drive. The disclosed apparatus includes: an analog-to-digital conversion module for receiving a plurality of analog signals generated by accessing an optical disc and for converting the plurality of analog signals into a plurality of digital signals with a sampling rate; a frequency control module coupled to the analog-to-digital conversion module for adjusting the sampling rate according to the plurality of digital signals; and a signal generation module coupled to the analog-to-digital conversion module for generating the tracking error signal according to the plurality of digital signals.

Abstract: An apparatus comprising a center error creation circuit, a center error offset injection circuit and a center error controller. The center error creation circuit may be configured to generate a center error signal in response to one or more photo-diode signals. The center error offset injection circuit may be configured to (i) offset the center error signal and (ii) generate an offset signal. The lens controller may be configured to adjust a lens in a sled housing at a mechanical center is response to the offset signal when the apparatus is in a rough seek mode.

Abstract: A system and method for printing a visible image onto an optical disc through tuning a driving signal of an optical pick-up unit are disclosed. The system includes a driving circuit, coupled to the optical pick-up unit, for providing a driving signal to drive the optical pick-up unit; and an adjusting circuit, coupled to the driving circuit, for controlling the driving circuit to adjust the driving signal according to a rotation source signal corresponding to a rotation of the optical disc.

Abstract: An optical pickup includes a first optical system for collecting first laser light emitted from a first laser light source onto a first disk, and guiding reflected light from the first disk to a photoreceptor; a second optical system for collecting second laser light emitted from a second laser light source onto a second disk, and guiding reflected light from the second disk to a photoreceptor; a second objective lens for collecting the second laser light onto the second disk and receiving the reflected light from the second disk, the second objective lens being movable in a radial direction passing through the center of the second disk, and a first objective lens for collecting the first laser light onto the first disk and receiving the reflected light from the first disk, the first objective lens being disposed offset from the radial direction and adjacently to the second objective lens.

Abstract: A servo controlling apparatus of a holographic information recording/reproducing system changes the foci of reference light and signal light in a depth direction of a holographic information storage medium to record information over a plurality of information layers. A servo control is changed from a normal servo operation to a between-movement servo operation while movement between information layers is made during a recording operation, and the servo control is changed back to the normal servo operation when the movement between information layers is completed. The between-movement servo operation maintains a servo control state that exists before the movement between information layers.

Abstract: A method for demodulating a focusing error signal in an optical disc system, comprising the steps of (A) generating a beam strength signal and the focusing error signal, (B) sampling the beam strength signal and the focusing error signal at an appropriate sampling rate, (C) removing a static offset from the beam strength signal and the focusing error signal, (D) calibrating a peak-to-peak value of the beam strength signal and the focusing error signal, and (E) determining an appropriate phase to (i) demodulate the focusing error signal and (ii) calculate a vertical position of a lens in relation to a disc.

Abstract: An optical pickup device includes a lens, a base plate, a supporting wall substantially perpendicular extending from the base plate, at least one cantilever beam, and at least one piezoelectric member. The lens is configured for converging a light beam onto an optical disc. The cantilever beam includes a fixing end and a free end. The fixing end is fixed in/attached to the supporting wall, and the free end suspends the lens thereat. The piezoelectric member is sandwiched between the free end and the base plate. The piezoelectric member is electrically polarizable along a polarization pivot thereof, and thus the length thereof along the pivot direction may be adjusted electrically. The polarization pivot is substantially perpendicular to the base plate and the cantilever beam.

Abstract: An optical pickup actuator includes a lens holder for holding an object lens and having a receiving area, coils in the receiving area of the lens holder, at least one magnet opposing the coils, a yoke plate having a first yoke for supporting the magnet, and a yoke structure having second yokes inserted into the yoke plate.

Abstract: According to an embodiment of the present invention, a semiconductor device used in an optical disk device driving an optical disk, includes: an optical pickup device detecting an optical signal irradiated to the optical disk and converting the detected optical signal into an electric signal to output the electric signal; and a light amount detecting circuit amplifying the electric signal output from the optical pickup device, the optical pickup device including a plurality of light receiving elements different in receiving sensitivity and the light amount detecting circuit including at least one amplifier or two or more amplifiers of the same amplifying characteristics.

Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.

Abstract: An apparatus for testing integrated circuits is disclosed. The apparatus for testing integrated circuits comprises an integrated circuit and a tester. The integrated circuit undergoing testing receives an input signal, and outputs an output signal from a first output terminal or a second output terminal according to a first pulse width of the input signal, and outputs an error signal according to a difference between the first pulse width and a second pulse width. The tester outputs the input signal according to the output signal and the error signal.

Abstract: The present invention provides an optical disk apparatus adapted to irradiate a predetermined track reliably with a laser beam in a seeking operation independently of the individual differences between tracking actuators and therefore optical pickups. A signal adjusting circuit 57 of a servo driver circuit 5 consists of a first amplifier 571 adapted to receive a period error signal that indicates the difference between a target period and a detection period and then output a reference drive signal having a prescribed amplitude in accordance with the difference, and a second amplifier 572 adapted to adjust the reference drive signal by being multiplied by the inverse number of a servo gain G which is different for each optical pickup 1. This allows the reference drive signal adjusted in accordance with the characteristics of a tracking actuator 12 of the optical pickup 1 to be input to a tracking drive signal generating circuit 58.

Abstract: An optical pickup is provided for preventing an objective lens from colliding with an optical recording medium at the stage of initial adjustments. The optical pickup device comprises a servo circuit, and a lens driver for driving an objective lens. In the servo circuit, a drive signal generator supplies the lens driver with one of a first focus drive signal for moving the objective lens in a direction closer to an information recording layer, and a second focus drive signal for moving the objective lens in a direction away from the information recording layer. A controller in a timing generator switches a signal supplied to the lens driver from the first focus drive signal to the second focus drive signal when the level changes by a predetermined range or more in a servo signal which is generated during a period in which the first focus drive signal is being supplied to the lens driver.

Abstract: A hybrid LDD includes a read channel to selectively output a read current, a plurality of write channels, each to selectively output a different write current, and an oscillator channel to selectively output an oscillator current. Additionally, the hybrid LDD includes programmable LDD controller that receives the plurality of enable signals from the external controller, and based on the enable signals, controls timing of the currents output by at least the write channels. The programmable LDD controller can also control timing of the currents output by the read and oscillator channels, based on the enable signals. Further and alternative embodiments are also provided.

Abstract: A servo control system and method is provided, comprising: a controller outputting a parameter control signal; a device having a parameter controlled based on the parameter control signal; a sensing circuit sensing the parameter of the device and generating a parameter error signal; a sinusoidal signal generator generating a sinusoidal signal; and a adder combining the parameter error signal and the sinusoidal signal, wherein the controller includes a servo equalizer that equalizes the added parameter error signal and the sinusoidal signal to output an equalized parameter control signal to adjust the parameter.

Abstract: An optical pickup apparatus for reading and writing information from and to optical data media in different formats and a method thereof are provided. The optical pickup apparatus comprises a twin laser diode (Twin LD), a diffraction element for dividing a laser beam incident on a data medium into five beams, and an optical detector for focusing a laser beam reflected from the data medium to detect an information signal and signals for carrying out servo controls. The divided beams are focused on a predetermined location in based on a data medium format, and the beam reflected from the data medium is received on and detected from the corresponding photodiodes of the optical detector so that a focus error signal and a tracking error signal are generated.

Abstract: There is provided a servo controller that can automatically set a filter intended for stabilizing a closed loop. The servo controller includes a repetitive controller. The repetitive controller implements repetitive control of a servo error signal (observation signal y(t)) by producing, by an adaptive line spectrum enhancer or adaptive linear prediction unit, a second error signal (including mainly a rotational sync signal) resulted from reduction of an irrotational sync component from a first error signal resulted from subtraction of the observation signal y(t) from a target signal r(t) and producing a third error signal obtained by sequentially updating the first error signal while making one-period delay of the second error signal.

Abstract: An optical recording apparatus for recording data to an optical storage medium. An optical pickup unit emits a light beam to a recording region of the optical storage medium, and receives the light beam reflected from the recording region. A sled mechanism moves the optical pickup unit in a predetermined direction. A processor obtains a boundary between a recorded region and an unrecorded region on the optical storage medium according to the reflected light beam, and obtains a recording address corresponding to the unrecorded region next to the boundary.

Abstract: This disclosure concerns an optical-disk reproduction apparatus comprising an amplifier which supplies information from an optical-disk as an information signal and a servo error signal; a servo controller controlling an optical-pickup read operation in response to the servo error signal; a rotation address producer producing a rotation address corresponding to a rotation angle of the optical disk; a memory in which the information signal, the servo error signal, and the rotation address are received and stored while correlated with one another; an error flag producer producing an error flag when determining that an error exists in the information signal; and a system controller determining a factor of production of the error flag using the servo error signal and rotation address stored in the memory, when the error flag producer produces the error flag, the system controller adjusting a servo parameter in the servo control circuit according to the determination result.

Abstract: An object lens driving device with reduced tilt even when focusing and tracking operations are performed simultaneously . The object lens driving device includes a movable unit with an object lens and an object lens holding member lens, elastic supporting rods arranged on two sides of the movable unit in a tangential direction and supporting the movable unit while allowing the movable unit to move relative to a fixed unit in a focusing direction and a tracking direction, and a driving unit that includes a focusing thrust force generation unit and a tracking thrust force generation unit. The force generation units generate a moment which acts to cancel out a tilt of the movable unit occurring in a supporting system when the movable unit moves in the focusing direction and the tracking direction.

Abstract: An optical pickup apparatus capable of compensating for a thickness deviation of a high-density optical recording medium is disclosed. The optical pickup apparatus has a light source, a collimator lens, a beamsplitter, and an objective lens system comprising a solid immersion lens which has a planar surface facing the substrate of the optical recording medium. The optical pickup apparatus has a position adjustment unit connected to the light source or the collimated lens, mating the light source or the collimated lens shift according to a focus control signal generated from the focus control unit. Further, a finite optical pickup apparatus in which a collimator lens is not used has a position adjustment unit connected to the light source, making the light source shift according to the focus control signal.

Abstract: Provided is a recording medium playback device intended to achieve a reduction in power consumption by stopping disk rotation during a period in which no content data is being read, while improving playability and responsiveness to external key inputs or the like. A system control section 106 instructs a servo control section 105 to stop rotating a spindle motor 102 after an optical pickup 103 completely reads the content data that is being reproduced, and to forcibly rotate the spindle motor 102 in order to start reading the next content data to be reproduced when the remaining amount of data accumulated in a buffer memory 113 falls to a threshold n or lower, the threshold n being calculated based on (a) a stabilization time of the spindle motor 102, (b) a moving time of the optical pickup 103, and (c) a speed at which data is read from the buffer memory 113.

Abstract: The apparatus comprises a pickup with a laser, a detector unit and an objective lens for reading data from or writing data to a Super-RENS optical storage medium having a track pitch below the optical resolution limit, the pickup generating a main beam for reading and/or writing of data and generating two satellite beams for providing a tracking error signal, the three beams being focused by the objective lens onto the optical storage medium, and the reflected light from the optical storage medium being guided onto the detector unit. The main beam and the two satellite beams have a light intensity on the optical storage medium being sufficient for providing a super-resolution effect for the main beam as well as for each satellite beam. The light intensity of the two satellite beams is each in the order of 50 to 100% of the intensity of the main beam, if the apparatus is used for reading of data.

Abstract: The present invention discloses an optical disc apparatus. The optical disc apparatus includes a rotation module for rotating a plurality of optical discs; a plurality of holding plates, which at least includes a first holding plate and a second holding plate, for loading the optical discs; a sled guide bar positioned between the first holding plate and second holding plate on a straight line; an optical pick-up unit for accessing the optical discs; and a sled motor, moveably positioned of sled on the sled guide bar, for loading the optical pick-up unit and driving the optical pick-up unit along the sled guide bar to access each of the optical discs loaded on the holding plates.

Abstract: This invention is a holographic recording medium including a track in which position information to specify a recording position and a reproducing position of page data is formed. The position information of the track is formed of position detection patterns. The position detection patterns each including a first detection mark row including center pits arranged at predetermined intervals; and a second detection mark row including side marks arranged at the same intervals as the intervals of the center pits, the side marks having lengths substantially corresponding to integral multiples of the intervals of the center pits. The second detection mark row is arranged adjacent to the first detection mark row such that both ends of the side marks are arranged so as to correspond to the center pits in a track width direction, and page data is recorded and reproduced on the basis of positions of the center pits or positions of the ends of the side marks.

Abstract: The invention provides an optical head device in which the influence of mechanical vibration generated at resonance frequencies of high orders (second and higher orders) can be eliminated and an optical recording/reproducing apparatus utilizing the same. Sidewalls are formed from both ends of a sidewall constituting the top side of a trapezoidal contour of a lens holder portion, the sidewalls extending in the form of a fan to define a predetermined angle between them. A damping system includes a weight in the form of a metal thin plate and a visco-elastic adhesive for bonding the weight to the sidewalls. The visco-elastic adhesive transfers vibration of the lens holder in the direction of an optical axis of an objective lens to the weight and has a viscous damping property which damps vibration of the weight in the direction of the optical axis.

Abstract: An optical data storage medium (1) comprising a dye-based recording layer is described. It has substantially parallel tracks for recording user information in a pattern of optically detectable marks, the tracks being provided with a guide groove, the groove being present in a user data area (3) and in an information area (2) and being trackable by a focused radiation beam (7) with the push pull method. The value of the normalized push pull signal (PPN) in the unrecorded information area is PPN-i and the value of PPN in the unrecorded user data area is PPN-u and PPN-i is lower than PPN-u. It is achieved that the information area of such an optical data storage may be read by a legacy optical data drive without causing damage to the drive. Further an apparatus for reading and a corresponding method are described.

Abstract: An optical disk drive is composed of comprising a tracking actuator, a sled motor, a sled filter developing an output corresponding to low frequency components of displacement of the tracking actuator, a pulse generating unit responsive to the output of the sled filter to develop drive pulses for driving the sled motor, and an pulse waveform adjusting unit designed to adjust waveforms of the drive pulses. The pulse waveform adjusting unit adjusts a waveform of relevant one of the drive pulses in response to the output of the sled filter and polarity of previous ones of the drive pulses.

Abstract: An actuator used with an optical pickup includes: a base on which a holder is fixed; a lens holder in which a plurality of installation holes are formed such that a plurality of objective lenses to record and/or reproduce optical discs having different recording densities are installed at different heights; a support member, which movably supports the lens holder, having one end coupled to the lens holder and the other end coupled to the holder; and a magnetic circuit which drives the lens holder in focusing and tracking directions. The plurality of installation holes include a first installation hole in which a first objective lens for at least one type of low density optical disc is installed, and a second installation hole in which a second objective lens for a higher density optical disc than the low density optical disc is installed.

Abstract: The present invention provides a read channel and a drive capable of suppressing deterioration in performance of a PLL and a Viterbi decoder by using a DC component eliminating means capable of higher-speed operation than hitherto. The location of an edge is determined by using differential of a read signal, and a DC component is detected from the midpoint level of the edge. Detection of a pseudo-edge due to a long mark or space signal is prevented by limiting the absolute value of a maximum or minimum of a differential coefficient when the location of the edge is determined from the differential coefficient of the read signal. Internal operation of a DC component detector is controlled according to the state of the PLL and the magnitude of the DC component.

Abstract: An optical information recording method of recording information three-dimensionally by irradiating a laser light beam onto a medium having a servo information plane on which address information and/or servo information is recorded, is disclosed. The method includes the steps of: dividing a laser light beam from one laser light source into laser light beams, the beam including a first light beam for reading the information, and a second light beam for recording information onto the recording medium; irradiating the first light beam onto the servo information plane to read the information from reflected light of the first light beam to read the information in which optical axes of the first light beam and second light beam are arranged coaxially; and irradiating the second light beam based on the read information to be focused onto a position in a depth direction perpendicular to a horizontal direction of the recording medium.

Abstract: Calibration methods are provided for determining servo parameters to enhance an optical drive in reading and writing a blank optical disc. First, test data is written on the blank disc with various writing parameters. Second, the written test data is read from the optical disc with various reading parameters. A plurality of quality measures are obtained, each corresponds to a specific combination of the writing parameter and the reading parameter. An optimal writing parameter and an optimal reading parameter are determined by comparing the quality measures with respect to both the reading and writing parameters respectively.

Abstract: An optical pickup device is adapted to read information signals from optical recording media of two different types such as a “DVD” and a “CD” for which two light beams with different wavelengths are used and comprises a photodetector having a single light receiving section that can be shared by optical recording media of two different types. Both the light beam reflected from the signal recording surface of the “DVD” 106a and the light beam reflected from the signal recording surface of the “CD” 106b are diffracted by the diffraction element 6 and focused to a same spot on the light receiving surface of the photodiode of a photodetector 7.

Abstract: Oral dosage formulations of the protease-resistant therapeutic polypeptides are provided. The dosage formulations for administration per dosage per day or per week are higher than the subcutaneous dosage. Included among the oral dosage formulations are tablets and capsules, including enteric-coated forms. Methods for treatment or prevention of diseases or conditions that are treatable or preventable by the administration of such oral dosage formulations of protease-resistant polypeptides are provided.

Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.