Abstract: Disclosed is an imaging system capable of reducing the generation of interference patterns in a state in which a beam of highly coherent electromagnetic waves is enlarged to a prescribed illumination area and used for illumination by moving the prescribed illumination region within a range of motion that is smaller than the illumination region.

Abstract: An optical pickup apparatus capable of irradiating an optical recording medium having a plurality of recording layers on which a signal is recorded with laser light includes a light source emitting the laser light, a light-concentrating element concentrating the laser light emitted from the light source on the optical recording medium, a phase difference element having a region divided into at least two regions which the laser light reflected by the optical recording medium enters and producing a phase difference between first light and second light reflected by a non-target layer which is not a target of recording or reproduction of the signal out of the plurality of recording layers and entering the at least two regions such that the first and the second light weaken each other, and a photodetector receiving the laser light emitted from the phase difference element.

Abstract: An optical pickup apparatus capable of irradiating an optical recording medium having a plurality of recording layers on which a signal is recorded with laser light includes a light source emitting the laser light, a light-concentrating element concentrating the laser light emitted from the light source on the optical recording medium, a phase difference element having a region divided into at least two regions which the laser light reflected by the optical recording medium enters and producing a phase difference between first light and second light reflected by a non-target layer which is not a target of recording or reproduction of the signal out of the plurality of recording layers and entering the at least two regions such that the first and the second light weaken each other, and a photodetector receiving the laser light emitted from the phase difference element.

Abstract: In an optical head apparatus including a first light source for emitting a first light beam having a first wavelength, a second light source for emitting a second light beam having a second wavelength different from the first wavelength, an objective lens, a photodetector, and first and second optical combining/splitting elements, the first optical combining/splitting element receives the first light beam from the first light source to outgo most of the first light beam therefrom to the second optical combining/splitting element and receives the first and second light beams from the second optical combining/splitting element to outgo most of the first and second light beams therefrom to the photodetector.

Abstract: An objective lens drive unit in an optical head includes a lens holder mounting thereon an objective lens, a sheet coil unit including a focusing coil and a tracking coil, and a pair of liquid crystal devices (LCDs) correcting a coma aberration and astigmatism of the optical beam from the objective lens, and an LCD drive circuit for driving the LCDs. The lens holder is cantilevered by a plurality of suspension wires, which deliver therethrough coil drive signals and LCD drive signals superposed on the coil drive signals.

Abstract: In an optical head apparatus including a first light source for emitting a first light beam having a first wavelength, a second light source for emitting a second light beam having a second wavelength different from the first wavelength, an objective lens, a photodetector, and first and second optical combining/splitting elements, the first optical combining/splitting element receives the first light beam from the first light source to outgo most of the first light beam therefrom to the second optical combining/splitting element and receives the first and second light beams from the second optical combining/splitting element to outgo most of the first and second light beams therefrom to the photodetector.