Abstract: An optical pickup apparatus, which reads signals recorded on first and second signal recording layers of an optical disc, includes: a laser diode; an objective lens to condense a laser beam to the first and second signal recording layers; and a collimating lens disposed in a light path of the laser beam between the laser diode and the objective lens and configured to correct a spherical aberration by moving in a light axis direction of the laser beam, and the objective lens includes a bifocal lens and is configured such that a second focal point does not coincide in position with the second signal recording layer when a first focal point coincides in position with the first signal recording layer, and the first focal point does not coincide in position with the first signal recording layer when the second focal point coincides in position with the second signal recording layer.

Abstract: An optical recording medium includes recording layers and intermediate layers. The recording layers include a diffraction grating that has a predetermined grating pitch and is obtained by alternately laminating first layers and second layers being transparent and having slightly different refractive indexes. The intermediate layers are transparent and have a larger thickness than that of the recording layers. In the optical recording medium, the recording layers and the intermediate layers are alternately laminated.

Abstract: An apparatus for compensating for a defect of a storage medium of an optical driving includes a memory to store sample values of a servo driving signal during at least one track sampled by a first signal and cycle information about the first signal; a servo driving signal estimator to estimate a servo driving signal during at least one next track using the sample values, the cycle information about the first signal, and cycle information based on a second signal; and a transmitter to transmit the servo driving signal estimated by the servo driving signal estimator to a servo driver of the optical driving device during a defect section of the storage medium; wherein the first signal is synchronized with a radial direction of the storage medium; and the second signal has a frequency higher than the first signal.

Abstract: A server device without a means for accessing an IC memory included in a data storage medium can check whether or not a data storage medium includes an IC memory. A portable optical disc medium (100) includes an IC memory (106) accessible through proximity wireless communication and a computer-readable recording part (101). The recording part (101) includes a user-data area (104) in which content data is recorded and a disc management information area (103) in which information for management of recording and reproducing the content data. In the disc management information area (103), medium identification information identifying the optical disc medium (100) and presence indication information indicating that the optical disc medium (100) includes presence of the IC memory (106) in a manner such that the presence indication information does not allow changing.

Abstract: An optical disc apparatus including means for calculating a spherical aberration correction quantity of an object lens, reproduced information signal generation means and spherical aberration correction means conducts spherical aberration correction, finds a spherical aberration correction quantity suitable for another layer by calculation on the basis of the obtained spherical aberration correction quantity, and sets the correction quantity as an initial correction quantity of spherical aberration correction. An optical disc apparatus including tilt correction quantity calculation means, reproduced information signal generation means and tilt adjustment means conducts tilt adjustment, finds a tilt correction quantity suitable for another layer by calculation on the basis of the obtained tilt correction quantity, and sets the correction quantity as an initial correction quantity of tilt adjustment.

Abstract: A reproducing system reproduces data recorded on an optical record carrier. The system includes a light source driver unit that modulates and controls a light output by a light source, such as a laser, in order to read data from an optical record carrier. The system is configured to operate in two modes: a reading mode and a light source lifetime extension mode. During the reading mode, the light source generates a continuous light output while data is read from the optical record carrier. During the light source lifetime extension mode, the light source generates a pulsed light output which may provide continued tracking and focus of the light on the optical record carrier, even when no data is being read from it.

Abstract: A micro-holographic data storage system and method. Micro-holograms are written to a data storage medium with two counter-propagating beams via objective recording lenses which have a first numerical aperture (NA) to make the micro-holograms larger. Alternatively, elongated micro-holograms can be produced using counter-propagating beams with different focus points. The micro-holograms are retrieved from the data storage medium using a single beam via an objective reading lens which has a second NA that is higher than the first NA. The data storage medium has a substrate with a plurality of tracks separated by a track pitch. The plurality of micro-holograms are each contained in each of the plurality of tracks, wherein, at least one of the plurality of micro-holograms has a width which is nearly equal to a width of the track pitch.

Abstract: A method of generating a memory disc in an optical disc drive is provided. A request for a change of an optical disc inserted in the optical disc drive into a memory disc is confirmed by detecting if a button included in the optical disc drive is operated. When the request is confirmed, the format of the optical disc may be changed. When an eject button is pushed in a predetermined pattern, for example, when the eject button is pushed for longer than a first reference time or pushed more than twice within a second reference time, the optical disc is initialized into a blank disc, file system data corresponding to the memory disc is recorded in a specific region of the blank disc according to ISO image generating program stored in a non-volatile memory included in the optical disc drive, and the blank disc is formatted.

Abstract: An information recording medium is provided that includes a recording portion (3), which is irradiated with a recording light or a reproducing light so that information is recorded or reproduced thereto or therefrom. The recording portion (3) contains a first phosphor and a photon-mode photosensitive material. The first phosphor has a property of absorbing a first light having a wavelength of ?1/n and then emitting a second light having a wavelength longer than that of the first light, where ?1 is a wavelength of the recording light. The photosensitive material absorbs the second light and then exhibits a change in an optical constant thereof. A n-photon absorption sensitivity of the first phosphor with respect to the recording light is greater than a n-photon absorption sensitivity of the photosensitive material with respect to the recording light, where n is an integer not less than 2.

Abstract: An optical reproducing apparatus connectable to optical pickups and a method of controlling an optical pickup thereof are provided. The optical reproducing apparatus measures resistance of an optical pickup on a port of a connection unit to which the optical pickup is connected, and determines the type of the optical pickup according to the measured resistance. Accordingly, optical reproducing apparatuses may be controlled according to the type of optical pickups, and manufactured using various optical pickups without checking the type of optical pickups, which allows convenient manufacturing of optical reproducing apparatuses.

Abstract: An optical head device includes a light source configured to emit a light beam, a light collecting optical system configured to converge the light beam onto an information recording medium, a hologram element configured to diffract the light beam reflected from the information recording medium, and a photodetector having a plurality of detection regions configured to receive the light beam diffracted by the hologram element. The hologram element has a plurality of diffraction regions separated from each other by a straight line extending in a track direction of the information recording medium. At least one of the plurality of diffraction regions has a pattern which introduces coma aberration in the track direction to the diffracted light.

Abstract: This invention relates to holographic film for recording multicolor volume holograms, especially full color volume reflection holograms, and to manufacturing techniques for such film, and to corresponding methods of recording multicolor and full-color volume, in particular volume reflection holograms. We describe a holographic film for recording a multicolor volume hologram, the film comprising: a carrier; a first photosensitive recording layer sensitive to one or both of red and green laser light; and a second photosensitive recording layer sensitive to blue laser light. Both the first and second photosensitive recording layers comprise silver halide and have a grain size of less than 30 nm, and at least one of the photosensitive recording layers has a thickness of greater than 3 ?m and less than 5 ?m.

Abstract: An optical drive apparatus includes: a phase-difference detection-signal generating unit that generates PEDr based on PEROd and PEFOd obtained by delaying a phase-lead output signal indicating a phase lead amount of DA with respect to DB and X that is changed to high at a timing at which NAND of the DA and the DB is changed from high to low and changed to low at a timing at which OR of the DA and the DB is changed from high to low, and generates PADr based on PAROd and PAFOd obtained by delaying a phase-lag output signal indicating a phase lag amount of the DA with respect to the DB by a predetermined time and the X; and a DPD signal generating unit that generates a phase difference signal indicating a phase difference between the DA and the DB based on the PEDr and the PADr, and generates a DPD signal based on the phase difference signal.

Abstract: Provided are an optical pickup apparatus and an objective lens which can record and/or reproduce information for discs with different recording densities and can realize simplification of the structure of themselves and reducing cost. When the expression (1) is satisfied, step differences of a step structure can be further reduced than those in the case that d1=?1(n?1) holds, and fine grooves corresponding to a steps structure, formed on an optical-surface transfer surface of a mold for molding the objective lens become shallow, to be easily processed. In addition, the moldability is enhanced because the material of the objective lens easily enters the inner portion of the grooves. Further, a fluctuation of a diffraction efficiency caused when wavelength of a light flux changes or temperature changes is reduced so that information can be recorded and/or reduced stably.

Abstract: A focus position control apparatus includes a memory unit configured to sequentially store a control signal for controlling a focus position of an optical beam to a desired position in synchronization with a clock signal at an associated one of clock addresses whose one round is completed as an optical disc rotates once, a memory data output unit configured to sequentially read the memory data stored in the memory unit in synchronization with the clock signal, a phase correction unit configured to correct, when the memory data output unit reads the memory data from the memory unit, a phase shift between a clock address for reading and a clock address for storing, and an adding unit configured to add an output signal of the memory data output unit to the control signal.

Abstract: An optical disc drive having an optical pickup head emitting a light beam to an optical storage medium, detecting the light beam reflected from the optical storage medium, and outputting a signal based on the received reflected light, having a jitter measuring unit measuring jitter in signals output from the optical pickup head and having an evaluation unit determining from the measured jitter if the optical storage medium is good or defective. The jitter measuring unit measures jitter in a train of 3T or longer marks or spaces from an optical storage medium to which digital information is recorded as a train of marks or spaces of length kT based on a period T and an integer k of two or more.

Abstract: According to one embodiment, single-sided dual-layer recordable disc 100 may be used. Information recording is performed by forming mark and space portions on data area DA using modulated laser power. Pp denotes the maximum laser power or peak power for forming the mark portion, and Pb denotes the bias power for forming the space portion. Power ratio Pb/Pp is calculated for each of recording layers L0 and L1. Information is recorded on any of the recording layers L0 and L1 based on the result of calculation. Here, the calculated power ratio Pb/Pp changes among the recording layers L0 and L1, thereby optimizing the recording condition for a multi-layer recordable optical disc within relatively short time.

Abstract: When a multilayered optical disc is used, the signal-to-noise ratio of a read signal is decreased as effective reflectance is extremely low due to the influence of reflection and absorption by front recording layers. Further, when a high-frequency modulation technology is used to suppress returned light noise of a laser, the erasure of recorded information is likely to occur on certain types of discs, making it difficult to simultaneously achieve the suppression of returned light noise of a laser and the prevention of the erasure of recorded information. To address the above problems, the present invention includes a section that performs a read by executing a multi-tone demodulation. The present invention also includes a section that controls the position and shape of a read light pulse to be radiated on a recording layer.

Abstract: An optical pickup compatible with different types of optically recorded media and an optical recording and/or reproducing system employing the compatible optical pickup, the compatible optical pickup including: a short wavelength light source emitting a short wavelength light; a low-density optical system emitting a long wavelength light; an objective lens focusing lights incident from the long wavelength light source and the low-density optical system onto an information storage medium; a single photodetector (PD) receiving the short and long wavelength lights reflected from the information storage medium; a detection lens focusing the short and long wavelength lights reflected from the information storage medium as a light spot onto the single PD; a first collimating lens positioned on an optical path of a light reflected, wherein the optical path is positioned between the objective lens and the single PD; and a driving unit adjusting a position of the first collimating lens.

Abstract: An optical disc apparatus for shortening time necessary for adjustment while maintaining an accuracy of a result of adjustment, determines “A” pieces (A?1, A<N, and “A” is an integer) of recording layers, upon arrangement of the recording layers of an optical disc having “N” pieces (N?3, “N” is an integer) of recording layers. With remaining “B” pieces (B?1, B<N, B=N?A, and “B” is an integer) of recording layers, the “B” pieces of correction values corresponding to the respective recording layers are calculated, upon basis of the correction values of a result of adjustment of other recording layers, on which the adjustment is executed, and thickness of substrate of the recording layers. On each recording layer, it is determined on whether the correction value is obtained with the adjustment process or the correction value is obtained with calculation, depending on an arrangement of the recording layers on the optical disc.

Abstract: An optical pickup includes: a first emitting unit to emit an optical beam of a first wavelength; a second emitting unit to emit an optical beam of a second wavelength; a third emitting unit to emit an optical beam of a third wavelength; an object lens to condense optical beams emitted from the first through third emitting units onto a signal recording face of an optical disc; and a diffraction unit provided on one face of an optical element or the object lens positioned on the optical path of the optical beams of the first through third wavelengths; wherein the diffraction unit includes a generally circular first diffraction region provided on the innermost perimeter, a ring zone shaped second diffraction region provided on the outer side of the first diffraction region, and a ring zone shaped third diffraction region provided on the outer side of the second diffraction region.

Abstract: An optical disc apparatus has: a spherical aberration correction unit (7) which corrects the spherical aberration generated in a light spot on a recording layer; a control unit (52) which focuses a light beam on a predetermined recording layer, and shifts the focal point position of the light beam from the current recording layer to another recording layer; and a focus jump control unit (60) which controls correction of spherical aberration and shift of the focal point position based on the interlayer distance between the current recording layer and a recording layer which adjoins in a direction opposite to a direction of shifting the focal point position of the light beam. By this configuration, focus jump is stably executed.

Abstract: A method of recording content comprising the steps of: providing a content storage medium comprising a pre-recorded grating or hologram; and illuminating a pre-recorded grating or hologram with a single recording beam to record content in the grating or hologram. The recording beam may increase the diffraction efficiency of the pre-recorded grating or hologram. Alternatively, the recording beam may form a new grating or hologram in close proximity to a pre-recorded grating or hologram.

Abstract: An optical information recording and/or reproducing apparatus comprises: a focusing unit (11) which collects generated near-field light on an optical disc (1); a first detector (17) which receives light reflected by the optical disc (1) and outputs an electric signal according to the quantity of the received light; and a distance control circuit (22) which controls the distance between the focusing unit (11) and a light entrance surface of the optical disc (1), using the electric signal that is output from the first detector (17), and the optical disc (1) has at least N (N is an integer of 2 or greater) number of information layers, and a distance d0 from the light entrance surface to a first information layer which is most distant from the light entrance surface and a distance dn from the light entrance surface to an Nth information layer which is closest to the light entrance surface satisfy the relationship of dn?d0×(1/25).

Abstract: An optical head apparatus including a holographic optical device which diffracts a light beam and includes a first diffraction region and a second diffraction region facing each other across a region dividing line passing through an optical axis of a light-collection optical system and extending in a radial direction of an optical disc, the first diffraction region having a grating pattern for generating diffracted light having a first wavefront and entering a first photoreception region and a second photoreception region, the second diffraction region having a grating pattern for generating diffracted light having a second wavefront and entering a third photoreception region and a fourth photoreception region, the first and second wavefronts having first and second coma aberrations in the radial direction of the optical disc, respectively, and the first and second coma aberrations having axes located off the optical axis.

Abstract: To provide a dye to be used for an optical recording medium excellent in both high speed recording characteristics and reproduction durability. A dye having an azo compound represented by the following formula coordinated to a metal ion: wherein the ring A represents a nitrogen-containing heteroaromatic ring containing a carbon atom and a nitrogen atom; X represents C—R1R2, an oxygen atom, a sulfur atom or N—R3, wherein each of R1, R2 and R3 which are independent of one another, represents a hydrogen atom, a linear or branched alkyl group, an aralkyl group, a cycloalkyl group, a linear or branched alkenyl group, an aryl group or an acyl group represented by —COR4, wherein R4 is a hydrocarbon group or a heterocyclic group which may be substituted; and the benzene ring B represents a benzene ring which may have a substituent(s), provided that adjacent substituents in the benzene ring B may be mutually bonded to form a ring.

Abstract: An environmental load information of an information recording medium is recorded on the information recording medium so as to recycle or dispose properly an information recording medium, which is not necessary any more. The information recording medium comprises a main information area (102) for recording or reproducing information and a recording area (101) for environmental load information, which is recorded with an environmental load information of the information recording medium.

Abstract: A servo processor for an optical disk drive is provided that includes: an analog-to-digital converter for converting versions of photodetector output signals into digital signals; and a digital signal processor configured to receive the digital signals, the digital signal processor being further configured to determine a focus error signal (FES) and a tracking error signal (TES) from the digital signals, the digital signal processor being further configured to process TES and FES through servo algorithms to produce tracking and focus control signals.

Abstract: A compound having a good durability against light and capable of producing desired liquid crystallinity after polymerization, and a polymerizable liquid crystal composition containing such a compound, are provided. Further, an optical element having a good durability against light, and an optical information writing/reading device employing such an element, are provided. A compound represented by CH2?CR1—COO—R2-Cy-Ph-R3—OCO—CR4?CH2. R1 and R4 are each preferably a hydrogen atom. R3 is preferably a C1-6 alkylene group wherein an oxygen atom is present or not present at an end of the group to be bonded to a cyclic group, and wherein some or all of hydrogen atoms bonded to carbon atoms in the group may be substituted by fluorine atoms; or an alkylene group wherein an oxygen atom is present at an end of the group to be bonded to a cyclic group.

Abstract: A mounting structure for an optical member comprising: an optical member; a holding member having the optical member mounted thereon; and a position adjustment member disposed between the optical member and the holding member, the position adjustment member configured to adjust a mounting position of the optical member.

Abstract: An optical pickup device includes a polarization diffraction grating to diverge an optical beam reflected from an optical disc and an optical detector to receive the optical beam diverged by the polarization diffraction grating, a polarization of 0 order diffracted light diffracted through the polarization diffraction grating is substantially perpendicular to that of a +1 order diffracted light diffracted therethrough, and a polarization filter having a plurality of domains is mounted between the polarization diffraction grating and the optical detector.

Abstract: The core of the present invention is a method and an apparatus for transformation of matter parameters through optical way. In course of said method, a multilateral pattern inside a sample matter is created by means of a specific imaging beam emitted by a light emitting device. The most significant application of the suggested method is for writing on optic data storage media. Further application concerns the analysis of the above-mentioned optical parameters, i.e. reading data from the storage media.

Abstract: An optical information recording medium (100) of the present invention includes an information layer (011) that allows information to be recorded thereon and reproduced therefrom by irradiation with a laser beam (040). The information layer (011) includes a reflective layer (002), a first dielectric layer (003), a recording layer (005) capable of undergoing a phase change by the irradiation with the laser beam (040) and a second dielectric layer (007) formed in this order from a side opposite to a laser beam incident side. The recording layer (005) contains Ge, Sb and Te. When Ge, Sb and Te contained in the recording layer (005) are represented by GexSbyTez in atomic number ratio, x, y, and z satisfy 0.39?x?0.48, 0.02?y<0.11, 0.40?z<0.56, and x+y+z=1. The recording layer (005) has a thickness of at least 10 nm but not more than 15 nm.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

Abstract: A tilt control method of a recording medium comprises fixing the recording medium to a recording reproducing apparatus; performing first tilt compensation in a state that the recording medium is stopped; and performing second tilt compensation in a state that the recording medium in which the first tilt compensation has been performed is rotated.

Abstract: An optical disc identifying device includes an optical pickup head, a digital signal processor and a radio frequency amplifier. The optical pickup head has a plurality of laser diodes and a lens. During a start-up procedure, a non-blue laser diode of the optical pickup head is turned on to irradiate a loaded optical disc, thereby generating an electronic signal. The digital signal processor outputs a driving signal, thereby controlling a motor driver to move the lens in a focusing direction. The radio frequency amplifier receives the electronic signal during the movement of the lens, thereby generating a first signal. The digital signal processor includes a detecting unit for comparing the first signal with a slicing signal to generate a pulse signal, and determining whether the optical disc is a blue-ray disc or a non-blue-ray disc according to a pulse number of the pulse signal.

Abstract: An object of the invention is to improve the quality of a servo signal and a reproduction signal. Shape-wise thicknesses tr1, tr2, . . . , and trN of a cover layer and first through (N?1)-th intermediate layers of an optical recording medium having refractive indexes nr1, nr2, . . . , and nrN are converted into thicknesses t1, t2, . . . , and tN of the respective layers having a predetermined refractive index “no” which makes a divergent amount equal to a divergent amount of a light beam resulting from the thicknesses tr1, tr2, . . . , and trN, a difference DFF between the sum of a thickness “ti” through a thickness “tj”, and the sum of a thickness “tk” through a thickness “tm” is set to 1 ?m or more (where i, j, k, and m are each any positive integer satisfying i?j<k?m?N), and the thicknesses t1, t2, . . . , and tN are calculated by products of a function f(n) expressed by the following formula (1), and the thicknesses tr1, tr2, . . . , and trN: f(n)=?1.088n3+6.1027n2?12.042n+9.

Abstract: Of the beams reflected by an optical disk, only peripheral beams excluding the push-pull region are used to generate a DPD signal in order to optimize internal wire connections among the light receiving areas of the optical detector and thereby reduce the amplification factor of the lens error signal, required for generating the tracking error signal of the DPP method. A beam reflected from a multilayered optical disk is divided into some beam diffraction areas. The divided beam diffraction areas and the light receiving areas are so arranged that the divided beams focus at different positions on the optical detector and that, when a beam is focused on a target recording layer of the disk, stray light from other than the target recording layer being reproduced does not enter into the servo signal light receiving area of the optical detector.

Abstract: The invention provides a method for testing an optical disk drive. The method comprises: resetting a successful number of a test and setting an upper limit for the successful number of the test; proceeding with a virtual writing by a laser beam with predetermined power; checking whether the output power is different from the predetermined power; if the output power is different from the predetermined power, determine the test fails, and if the output power is not different from the predetermined power, plus one to the successful number, wherein the optical disk drive passes the test when the number of successful test reaches the upper limit. The invention can reduce the time of testing the optical disk drive.

Abstract: Where a hybrid disc has different types of media, the light spot moves among recording layers of the different media, after loading the disc into an optical disc apparatus, there is a problem that information on a media type of each recording layer should be recorded in DI etc. of the optical disc. Detailed information on the hybrid disc is stored in DI, by changing a disc layer type identifier or a disc structure in DI such as BCA or PIC on the optical disc.

Abstract: An equalization filter device includes: an equalization filtering section which has a digital filter and which performs equalization processing on an input signal and updates tap coefficients, which are set for multipliers provided in the digital filter, according to an error between an equalization signal generated by the equalization processing and a target signal; and a tap coefficient holding section which holds the tap coefficients, which are set for the multipliers, in a sequential manner at a necessary timing, wherein the equalization filtering section starts tap coefficient updating calculation processing using the tap coefficients, which are held in the tap coefficient holding section, at an end timing of an abnormal section of the input signal specified on the basis of an abnormal detection result regarding the input signal.

Abstract: An optical pickup head is provided, including a laser diode set, an optical element set and an optical signal detector. The laser diode set is a laser light source capable of emitting single wavelength, two wavelengths or three wavelengths laser lights. Optical element set includes a low reflectivity beam-splitter and an objective lens. The low reflectivity beam-splitter has an average reflectivity ranging from 10% to 30%. After reflected twice by low reflectivity beam-splitter, the light fed back from recording medium to the laser diode set is reduced to avoid laser noise problem. Moreover, with the optical signal detector having a tilt ? ranging from 3° to 15° to optical axis, the optical signal detector can directly reflect the incident laser light into a different direction so that the reflected light will reduce the feedback light to the laser diode set.

Abstract: Optical recording mediums, and methods and systems for manufacturing optical recording mediums are provided. The optical recording medium includes a substrate on which a recordable layer and a reflective layer are formed. The reflective layer includes a predefined proportion of at least copper and zinc, wherein the predefined proportion is 50-75% copper and 15-45% zinc by mass. The recordable layer can either be formed over the substrate or the reflective layer, and is configured to record data. A protective layer is also formed over the reflective layer or recordable layer.

Abstract: There are provided optical data storage media and methods of optical data storage using the same. The optical data storage media comprises a non-linear sensitizer capable of absorbing actinic radiation to cause upper triplet energy transfer to a reactant that undergoes change upon triplet excitation. The refractive index change (?n) of the medium is at least about 0.005, or even at least about 0.05.

Abstract: An optical disc apparatus includes a multilayer optical disc having a reproduction-only recording layer and a recording layer of the recordable area, on the disc, to record and reproduce the disc by the same wavelength laser light, so that a seek operation is performed rapidly, and a generation method tracking error signal (TE) is switched over by using a DPD method and push-pull method in response to a target layer to which a focus jump is applied, for a time period during which a tracking servo loop is opened in association with a focus jump.

Abstract: The present invention provides an optical pickup device including: a light source for emitting light in a first wavelength range including a wavelength of 405 nm; an optical element for transmitting the light emitted from the light source and guiding the emitted light to an optical disc, and for transmitting light reflected from the optical disc and guiding the reflected light to a detector unit; a supporting member for supporting the optical element through an adhesive; a first light blocking member for blocking the light emitted from the light source from entering the adhesive when the optical element guides the emitted light to the optical disc; and a second light blocking member for blocking the light reflected from the optical disc from entering the adhesive when the optical element guides the reflected light to the detector unit.

Abstract: An objective lens is described, which is switchable between a far-field mode and a near-field mode.

Abstract: An electronic device that performs at least reading or regeneration of data in or from a hologram disc is characterized by including an objective lens 11 disposed opposite a hologram disc (MH) 1; a laser light source 5 that emits a beam toward the objective lens 11; and a light receiving element 17 that receives a beam reflected from the hologram disc (MH) 1 by way of the objective lens 11, wherein a corner cube array 8 that reflects a portion of a beam traveling from the laser light source 5 toward the objective lens 11 is interposed between the laser light source 5 and the objective lens 11.

Abstract: An optical pickup device corresponding to a plurality of media is provided. The optical pickup device includes a light emitting system and a light receiving system including a plurality of light sources and a light transmission system shared by the light emitting system and the light receiving system, configured to irradiate light on a medium, and receive light reflected from the medium. The light transmission system irradiates light from the light emitting system to be appropriately focused on the medium, receives light reflected from the medium, and transports light to the light receiving system. The light transmission system includes one beam splitter corresponding to the light emitting system and the light receiving system and a position-changing collimating lens shared to correspond to a plurality of media. The position-changing collimating lens is disposed between the beam splitter and the medium, the position being controlled according to optical characteristics of the media.

Abstract: An optical data recording medium, in which irradiation of a light beam is used for recording and/or reproducing data includes (i) a substrate having an a rise and/or a recess which are a light-incident surface, (ii) a reflective layer, provided on the light-incident surface of the substrate, for reflecting the light beam, (iii) a light absorption layer for converting, to heat, a light of the light beam to heat on the surface of the reflective layer, (iv) a reproducing layer, provided on the surface of the heat-light converting layer, having a transmittance that changes in accordance with a light intensity distribution of the light beam. The optical data recording medium is excellent in super-resolution property, and enables reproduction of a shorter mark length.