Abstract: A visible light communication system having a transmission apparatus for modulating a transmission signal to a multiple-value number and a reception apparatus for demodulating a multiple-value modulated transmission signal is provided. The transmission apparatus includes a plurality of light emitters for emitting light in different colors, a chromaticity coordinates calculator for mapping a digital value to a chromaticity coordinates value, and a light intensity controller for controlling a light intensity of each of the light emitters based on the chromaticity coordinates value corresponding to the digital value. The reception apparatus includes a plurality of light receivers having different spectral characteristics, a chromaticity coordinates calculator for calculating a chromaticity coordinates value according to a received light intensity detected by each of the light receivers, and a demodulator for demodulating the digital value from the chromaticity coordinates value.

Abstract: Provided are a lighting apparatus, and an optical inspection apparatus and an optical microscope using the lighting apparatus. The lighting apparatus includes a light source that emits light, an optical device that outputs light that is more uniformly intense over a predetermined ray angle distribution than light input thereto; a multi-reflection device that reflects light multiple times, the multi-reflection device having a light incident surface receiving light and a light emission surface that emits multiply reflected light, and a light diffusion device that diffuses the light emitted from the light emission surface of the multi-reflection device. The light source, the optical device, the multi-reflection device, and light diffusion device share an optical path.

Abstract: An apparatus for detecting a defect of an object may include a light emitter configured to emit straight polarized lights having different polarized directions, a spatial filter having openings through which the straight polarized lights selectively pass, an optical member configured to condense the straight polarized lights, which pass through the openings, on the object, and a light detector configured to detect lights reflected from the object. Thus, the defect may be accurately detected in a short time.

Abstract: A visible light communication system having a transmission apparatus for modulating a transmission signal to a multiple-value number and a reception apparatus for demodulating a multiple-value modulated transmission signal is provided. The transmission apparatus includes a plurality of light emitters for emitting light in different colors, a chromaticity coordinates calculator for mapping a digital value to a chromaticity coordinates value, and a light intensity controller for controlling a light intensity of each of the light emitters based on the chromaticity coordinates value corresponding to the digital value. The reception apparatus includes a plurality of light receivers having different spectral characteristics, a chromaticity coordinates calculator for calculating a chromaticity coordinates value according to a received light intensity detected by each of the light receivers, and a demodulator for demodulating the digital value from the chromaticity coordinates value.

Abstract: A focus control apparatus and method capable of generating a focus position signal according to focus position error even in proximity to an interface between regions having different thicknesses, to perform a high precision focus position control using the focus position signal, are provided. A focus control apparatus includes an error signal correction portion configured to process a focus error signal that indicates an error of a focus position of an optical system with respect to an object. Moreover, the focus control apparatus includes a region conversion detection portion configured to output a region signal that corresponds to a first region or a second region of the object. The first and second regions of the object have different respective heights.

Abstract: A visible light communication system having a transmission apparatus for modulating a transmission signal to a multiple-value number and a reception apparatus for demodulating a multiple-value modulated transmission signal is provided. The transmission apparatus includes a plurality of light emitters for emitting light in different colors, a chromaticity coordinates calculator for mapping a digital value to a chromaticity coordinates value, and a light intensity controller for controlling a light intensity of each of the light emitters based on the chromaticity coordinates value corresponding to the digital value. The reception apparatus includes a plurality of light receivers having different spectral characteristics, a chromaticity coordinates calculator for calculating a chromaticity coordinates value according to a received light intensity detected by each of the light receivers, and a demodulator for demodulating the digital value from the chromaticity coordinates value.

Abstract: An electron beam apparatus includes at least one electron beam column. The at least one beam column includes an electron beam optical system to irradiate an electron beam on a surface of a sample, and a detection system to detect electrons generated from the electron beam. The electron beam optical system includes an object lens to focus the electron beam on a surface of the sample. The object lens includes an electrostatic lens having a first electrode to which a first voltage is applied, a second electrode that is grounded, a third electrode to which a second voltage is applied, and a fourth electrode that is grounded. The first through fourth electrodes sequentially arranged relative to the sample.

Abstract: Provided are a lighting apparatus, and an optical inspection apparatus and an optical microscope using the lighting apparatus. The lighting apparatus includes a light source that emits light, an optical device that outputs light that is more uniformly intense over a predetermined ray angle distribution than light input thereto; a multi-reflection device that reflects light multiple times, the multi-reflection device having a light incident surface receiving light and a light emission surface that emits multiply reflected light, and a light diffusion device that diffuses the light emitted from the light emission surface of the multi-reflection device. The light source, the optical device, the multi-reflection device, and light diffusion device share an optical path.

Abstract: An electron beam apparatus includes at least one electron beam column. The at least one beam column includes an electron beam optical system to irradiate an electron beam on a surface of a sample, and a detection system to detect electrons generated from the electron beam. The electron beam optical system includes an object lens to focus the electron beam on a surface of the sample. The object lens includes an electrostatic lens having a first electrode to which a first voltage is applied, a second electrode that is grounded, a third electrode to which a second voltage is applied, and a fourth electrode that is grounded. The first through fourth electrodes sequentially arranged relative to the sample.

Abstract: An apparatus for detecting a defect of an object may include a light emitter configured to emit straight polarized lights having different polarized directions, a spatial filter having openings through which the straight polarized lights selectively pass, an optical member configured to condense the straight polarized lights, which pass through the openings, on the object, and a light detector configured to detect lights reflected from the object. Thus, the defect may be accurately detected in a short time.

Abstract: A focus control apparatus and method capable of generating a focus position signal according to a real focus position error even in proximity to the interference between regions having different thicknesses to perform a high precision focus position control using the focus position signal are provided.

Abstract: A polarization converting optical system and a liquid crystal projection apparatus including the polarization conversion optical system are provided. The polarization conversion optical system includes a light incident surface; a light exit surface having first and second light exit regions; a half-wave plate disposed on the first light exit region; and a plurality of polarization separating surfaces, between the light incident surface and the light exit surface, which divide light into first S-polarization and P-polarization components and second S-polarization and P-polarization components, deviating the second S-polarization component and the first P-polarization component in a direction inclined with respect to an optical axis, and emitting the S-polarization components through the first light exit region and emit the P-polarization components through the second light exit region.

Abstract: An optical system is provided. The system includes a lens having a negative refractive power to which light is incident from an imaging target object; a compound eye optical element; and an imaging device for receiving the light passing through the lens and the compound eye optical element, wherein the compound eye optical element includes a plurality of optical elements to which the light passing through the lens is incident.

Abstract: An imaging lens that focuses light from a subject on an imaging surface, a lens holder that holds the imaging lens, a holder that holds the lens holder so as to be capable of moving along the optical axis of the imaging lens and capable of rotating in a tilting direction with respect to the optical axis, magnets and coils that independently cause drive forces to act in the direction along the optical axis with respect to the lens holder at at least three locations of the periphery of the lens holder, a Hall element that detects the attitude of the lens holder with respect to the optical axis, and a control apparatus that controls the magnitude and direction of the drive force of each coil in accordance with the detection output of the Hall element. In accordance with the present invention, in the cladding lens unit, it is possible to perform a movement in an optical axis direction of the imaging lens and a tilt movement with respect to the optical axis with a simple constitution.

Abstract: A polarization converting optical system and a liquid crystal projection apparatus including the polarization conversion optical system are provided. The polarization conversion optical system includes a light incident surface; a light exit surface having first and second light exit regions; a half-wave plate disposed on the first light exit region; and a plurality of polarization separating surfaces, between the light incident surface and the light exit surface, which divide light into first S-polarization and P-polarization components and second S-polarization and P-polarization components, deviating the second S-polarization component and the first P-polarization component in a direction inclined with respect to an optical axis, and emitting the S-polarization components through the first light exit region and emit the P-polarization components through the second light exit region.

Abstract: A visible light communication system having a transmission apparatus for modulating a transmission signal to a multiple-value number and a reception apparatus for demodulating a multiple-value modulated transmission signal is provided. The transmission apparatus includes a plurality of light emitters for emitting light in different colors, a chromaticity coordinates calculator for mapping a digital value to a chromaticity coordinates value, and a light intensity controller for controlling a light intensity of each of the light emitters based on the chromaticity coordinates value corresponding to the digital value. The reception apparatus includes a plurality of light receivers having different spectral characteristics, a chromaticity coordinates calculator for calculating a chromaticity coordinates value according to a received light intensity detected by each of the light receivers, and a demodulator for demodulating the digital value from the chromaticity coordinates value.

Abstract: Provided is an image projecting apparatus, including: a polarization separator having a polarization separation surface which transmits or reflects illumination light and reflection light reflected from a reflective image display unit according to polarization directions of the illumination light and the reflection light; and a polarization direction rotating member, disposed between the polarization separator and the reflective image display unit, which rotates a polarization direction of light passing twice through the polarization direction rotating member by 90° about an optical axis of the polarization separator.

Abstract: An optical pickup includes a light emitting unit, an object lens, and a correction unit. The object lens focuses a beam of light onto a recording surface of an optical disc. The correction unit has a light transmitting surface. A plurality of electrodes are arranged on a plurality of divided areas of the light transmitting surface. The correction unit corrects an aberration caused by a tilt of an optical axis of the beam of light relative to the recording surface of the recording disc by applying voltages to the electrodes. The applied voltages correspond to the tilt of the optical axis of the beam of light. The correction unit also changes phases of the beam of light passing through the divided areas of the light transmitting surface.

Abstract: A servo device and an optical disc information recording and reproducing device using the same, which can improve the performance of a focus servo by correctly detecting a focus error when a main beam L1 and two sub-beams L2 and L3 are irradiated to an optical disc X, sizes of two sub-spots being irradiation ranges of the sub-beams L2 and L3 irradiated to the optical disc X are detected and compared after one sub-beam L2 is defocused on a positive position with respect to the optical disc X and another sub-beam L3 is defocused on a negative position with respect to the optical disc X, such that a focus of the main beam L1 on the optical disc X can be appropriately controlled.

Abstract: Disclosed herein is an optical pickup device and method of adjusting the same. The optical pickup device and method of adjusting the same of the present invention can correct aberrations due to variation of thickness of an optical disc and dispersion of the emission wavelength by a semiconductor laser, which are generated in manufacturing processes of the optical disc and the optical pickup device, correct aberrations generated in recording/reproducing of the optical disc, due to variation of the emission wavelength and secular changes in the environment of the semiconductor laser, simplify and miniaturize the construction of the optical pickup device, and easily reduce manufacturing cost thereof. The optical pickup device of the present invention has a semiconductor laser (1) and a photo diode (13) for narrowing light emitted from the semiconductor laser (1) to a predetermined diameter and for detecting light reflected and returned from an optical disc (14).