4772 results about "Optical pickup" patented technology

Disclosed is an optical disk barcode forming method wherein, as information to be barcoded, position information for piracy prevention, which is a form of ID, is coded as a barcode and is recoded by laser trimming on a reflective film in a PCA area of an optical disk. When playing back the thus manufactured optical disk on a reproduction apparatus, the barcode data can be played back using the same optical pickup.

An objective optical system for focusing light from a light source onto optical recording media includes an aperture control filter with a diffractive optical function formed as a glass plate with an aperture control structure on one side and a diffractive optical structure, such as a plastic diffractive optical element adhered to the glass plate on the other side, and an objective lens. The objective optical system focuses three light beams of three different wavelengths at three different numerical apertures onto desired positions of three different recording media with substrates of different thicknesses, such as a BD (or an AOD), a DVD, and a CD, that introduce different amounts of spherical aberration in the focused beams. The objective optical system provides compensating spherical aberration to the three light beams while keeping constant the distance between the aperture control filter with a diffractive optical function and the objective lens.

A LADAR apparatus and a method for use in receiving a LADAR signal are disclosed. The apparatus includes an optical pickup capable of picking up a plurality of optical signals; a timing synchronization reference; a time domain multiplexer capable of multiplexing the optical signals into a multiplexed optical signal relative to the timing synchronization reference; and an optical detector capable of detecting the multiplexed optical signal. The method include time domain multiplexing a plurality of LADAR signals into multiplexed LADAR signal; detecting the multiplexed LADAR signal; and demultiplexing the detected LADAR signal.

An optical recording and reproduction method, optical pickup device, and optical recording and reproduction device are provided, in which an optical recording medium is irradiated with near-field light to perform recording and/or reproduction, and wherein two or more recording and reproduction beam spots are positioned in a recording and reproduction area between guide tracks on the optical recording medium to perform recording and/or reproduction, as a consequence of which application to near-field optical recording and reproduction is ideally performed, and high transfer rates become possible.

An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted ray of the second light flux, where n stands for an integer other than zero.

On one side of a liquid crystal layer, a first electrode is provided, and, on the other side of the liquid crystal layer, a second electrode, composed of a plurality of individual electrodes, and a third electrode are provided. The second and third electrodes have holes that are increasingly small away from the liquid crystal layer. When the potential at the third electrode is set equal to or lower than the potential at the second electrode, the liquid crystal layer acts as a convex lens; when the potential at the third electrode is set higher than the potential at the second electrode, the liquid crystal layer acts as a concave lens. The range in which the focal length can be varied depends on the diameters of the holes, and giving the holes of the different electrodes varying diameters helps widen the range. Moreover, conductors can be laid to reach the electrodes at the outer edges thereof so as not to directly face the liquid crystal layer. This helps eliminate the influence of the conductors on the electric field distribution in the liquid crystal layer.

An objective optical system for use in an optical pickup apparatus which reproduces and/or records information on an information recording surface of first-third optical disks, the objective optical system includes a first optical element, a first part comprising a material A, a second part comprising a material b, wherein the first part and the second part are laminated on the first optical element in an optical axis of the objective optical system, and the material A and the material B have different Abbe constants for d-line each other and a first phase structure formed on a boundary between the first part and the second part.

A photodetector used in, for example, an optical pickup device includes: a photodetection unit including a plurality of photodetection elements and provided on a semiconductor chip; a light transmitting unit formed on the upper surface of the photodetection unit; and a light shielding layer having an optical aperture and disposed on the upper surface of the light transmitting unit, with these components being formed integrally. The light transmitting unit is configured such that the distance between the optical aperture and the photodetection unit is maintained constant, and the optical aperture is formed such that the inner portion of an incident light beam passes therethrough. The positioning of the photodetector and the positioning of the optical aperture such as a pinhole or a slit for adjusting the light beam entering the photodetection elements of the photodetector can be made at the same time.

A three-dimensional imaging system uses a single primary optical lens along with various configurations of apertures, refocusing facilities, and the like to obtain three offset optical channels each of which can be separately captured with an optical sensor.

The present invention provides an optical disk identification device for use in an optical disk reproduction apparatus for reproducing a plurality of types of optical disks based on information recorded on the optical disks. Recorded information is reproduced from an optical disk 1 while an optical pickup 3 is fixed at a focal position Pf. A focal position detector 32 generates a focal position detection signal Sg that is either at a high level or at a low level at the focal position Pf based on reproduced signals Sa, Sb, Sc, Sd. An RF signal detector 20 detects an RF signal Srf from the reproduced signal based on the focal position detection signal Sg. A recording density identifier 31, S14, S20 identifies the recording density of the optical disk based on the RF signal. A format identifier S16 to S24 identifies the type of the optical disk based on the detected recording density.

An optical pickup apparatus for conducting recording and/or reproducing information of an optical information recording medium, comprises a light source; a converging optical system having an objective lens; and a photo-detector. The converging optical system comprises a plastic lens and a spherical aberration deviation correcting element to correct deviation of a spherical aberration of the converging optical system. A numerical aperture of the objective lens at an image-side is 0.65 or more.

The present invention provides a photodetector-amplifier circuit capable of eliminating an influence of noise due to stray light entering a non-selected photodetector to stably select and switch a photodetector. The photodetector-amplifier circuit of the present invention comprises photodetectors 12 and 13. The photodetector 12 is connected via a switch 16 between an inverting input terminal of an operational amplifier 11 and GND, and is also connected via a switch 18 to a voltage source Vcc. The photodetector 13 is connected via a switch 17 to the inverting input terminal of the operational amplifier 11 and GND, and is also connected via a switch 19 to the voltage source Vcc.

Methods and apparatus are disclosed for buffering and reordering data blocks read simultaneously from multiple tracks of an optical disk, so that they may be delivered in sequential order to a host computer. The methods involve the use of numerous processes to receive read commands, position an optical pickup, handle memory management tasks, process data blocks as they arrive, and send data blocks to the host computer in sequential order as they become available. The reordering of data blocks is achieved by checking each data block as it arrives in a "read process" to see if it may be linked in a sequential chain with a data block that arrived from the next track. Additionally, methods for determining if a requested data block is in the range of blocks that are currently being read, and methods for determining when the optical pickup may be moved to read the next set of tracks are described.

An optical pickup apparatus includes a first light source to emit a first light beam having a predetermined wavelength, a first optical path changer to change a proceeding path of the first light beam, an objective lens to focus the first light beam on a recording medium, a diffraction member to divide the first light beam reflected by the recording medium into five light regions, the diffraction member having a first diffraction region having a wide width in a direction corresponding to a tangential direction of the recording medium and second through fifth diffraction regions sequentially arranged around the outside of the first diffraction region in a direction corresponding to a radial direction of the recording medium, and a first photodetector having first through fifth light receiving portions to receive the first light beam reflected by the recording medium.

The gallium nitride group semiconductor laser device of this invention includes an active layer made of a nitride semiconductor formed between cladding layers and/or guide layers made of a nitride semiconductor on a substrate, wherein a light absorption layer is formed between the substrate and one of the cladding layers located closer to the substrate, the light absorption layer being made of a semiconductor having an energy gap substantially equal to or smaller than an energy gap of the active layer.

An optical device having a sub-wavelength grating formed in a specified region is disclosed that is able to prevent wave front degradation accompanying a phase difference of a polarized light beam passing through the optical device. The optical device includes a circular-belt-like region where the sub-wavelength diffraction grating is formed, and a center portion where the sub-wavelength diffraction grating is not formed. A vertically polarized light beam used for operations on a blue-light optical recording medium A has a phase difference in the sub-wavelength diffraction grating to be an integral multiple of 2π and hence is transmitted through the sub-wavelength diffraction grating. A horizontally polarized light beam used for operations on a blue-light optical recording medium is diffracted by the sub-wavelength diffraction grating. The light path length L1 of the light beam passing through the circular-belt-like region is the same as that of the light beam passing through the center portion without the sub-wavelength grating.

An improved optical recording medium is provided, and includes a surface of the optical recording medium having at least pits and grooves formed therein, a recording layer formed adjacent the surface of said optical recording medium, and a light transmissive layer formed adjacent the recording layer. Information is recorded and/or reproduced by irradiation of light from an optical pickup employing an objective lens having a numerical aperture of 0.7 or larger through the light transmission layer. At least a surface layer of said light transmissive layer is formed of a material having a Young's modulus of 70 GPa or larger thereby greatly reducing or eliminating scratches from the surface of the optical recording medium while allowing for an increase in the storage capacity of the optical storage medium.

An optical pickup and an optical recording and/or reproducing apparatus adopting the same are provided. The optical pickup includes an optical unit, first and second objective lenses, and an optical path switching unit. The optical unit illuminates light onto an information storage medium and receives light reflected from the information storage medium to detect an information signal and/or an error signal. The first and the second objective lenses focus incident light to form a light spot on an information storage surface of the information storage medium. The optical path switching unit selectively directs the light incident from the optical unit to one of the first and second objective lenses. In the optical pickup, since the light quantity directed to a plurality of objective lenses may be maximized, optical efficiency is increased and thus high-speed operation may be attained.