Abstract: Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.

Abstract: An allowable temperature range satisfying phase matching conditions of a wavelength conversion device is widened. A wavelength conversion light source includes a semiconductor laser diode device (1) applied with an antireflection film (3), a lens (4) arranged opposite to the semiconductor laser diode device (1), an optical fiber (5) having a Bragg grating (6) arranged in a core thereof, and a wavelength conversion device (8) formed of a nonlinear optical crystal on which light from the semiconductor laser diode device (1) is incident. In the wavelength conversion light source, the semiconductor laser diode device (1) oscillates in coherent collapse mode.

Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.

Abstract: Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.

Abstract: Provided are a speckle removing light source capable of removing speckle by using laser light whose wavelength is temporally changed and a lighting apparatus for producing an image from which the speckle is removed. Provided is a speckle removing light source, including: a light source for outputting laser light; and a light frequency modulator for changing a wavelength of the laser light, in which: the wavelength of the laser light outputted from the light source is temporally changed by the light frequency modulator; and the light frequency modulator has a predetermined period set for changing the wavelength of the laser light. Also, provided is a lighting apparatus, including: a spatial light modulator illuminated with the laser light outputted from the speckle removing light source to produce an image, in which the spatial light modulator has a period set for producing the image, and the period is longer than the period for changing the wavelength of the laser light by the light frequency modulator.

Abstract: An object of the present invention is to provide a position detecting device that allows simultaneous use by a plurality of users by recognizing positional information about a plurality of pointers and associating the pointers and the users. A position detecting device of the invention includes a rear projector (1) that projects an image, a projection screen (3) that displays the image projected from the rear projector (1), imaging means (4) that is located near the rear projector (1) and that takes an image of light rays emitted from pointers (10, 20), from the rear of the projection screen (3), and coordinate calculating means (5b) that analyzes the image taken by the imaging means (4) to detect the two-dimensional positions in the detection areas where the light rays from the pointers (10, 20) are detected.

Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.

Abstract: An object is to provide a position detecting device that is able to accurately detect an indicated position via an indicating unit or device even when a water droplet or the like is formed upon the position-detecting-device's surface.

Abstract: A position detecting apparatus includes an indicating unit 2 for projecting light onto the front surface of a display screen 11 on which imaging light is projected from the back thereof by a projector 12, an imaging unit 3 placed at the back of the display screen 11, for picking up from the back thereof the light projected by the indicating unit 2 and for converting the light into electric signals, and an image processing unit 4 for analyzing the electric signals obtained from the imaging unit 3 and for calculating a position on the display screen 11, of the indicating unit 2.

Abstract: An allowable temperature range satisfying phase matching conditions of a wavelength conversion device is widened. A wavelength conversion light source includes a semiconductor laser diode device (1) applied with an antireflection film (3), a lens (4) arranged opposite to the semiconductor laser diode device (1), an optical fiber (5) having a Bragg grating (6) arranged in a core thereof, and a wavelength conversion device (8) formed of a nonlinear optical crystal on which light from the semiconductor laser diode device (1) is incident. In the wavelength conversion light source, the semiconductor laser diode device (1) oscillates in coherent collapse mode.

Abstract: A reflection element 3 disposed in an optical waveguide element 2 returns a part of light to a semiconductor laser diode element 1 so that the semiconductor laser diode element 1 oscillates in a coherent collapse mode, and a semiconductor light amplifier 7 is optically coupled to the optical waveguide element 2, and amplifies an optical output from optical waveguide element 2, so as to provide a high-power fundamental-wave light source.

Abstract: A solid-state laser device includes: a first solid-state laser medium 1 that emits light at a first wavelength that produces fluorescence through excitation; a second solid-state laser medium 2 that is arranged coaxially, is excited by the light at the first wavelength emitted by the first solid-state laser medium 1, and emits light at a second wavelength; two reflection means 3 and 4, which are arranged coaxially with the solid-state laser media and on both outsides of the solid-state laser media, for resonating a light component generated in an axis direction among the fluorescence; and an excitation light source 5 that excites one of the solid-state laser media, wherein the reflection means 4 has a predetermined reflectance with respect to each of the two wavelengths and laser light at the two different kinds of wavelengths is outputted separately or simultaneously with one resonator and one excitation light source.

Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes; and a wavelength converter for converting the laser light into harmonic light.

Abstract: In a home VTR, a color signal processing circuit is capable of reproducing a color signal recorded as a lower converted color signal and preventing color unevenness which necessarily creates during visualizing. To avoid an adverse effect due to phase fluctuation created during reproducing, the color signal processing circuit is provided with a circuit for synchronizing a carrier with the phase fluctuation. In this circuit, an open loop circuit is connected to a closed loop circuit to achieve such synchronization. Specifically, the phase fluctuation in a low-frequency range is synchronized by a feedback feature of the closed loop circuit, while the phase fluctuation in a high-frequency range is synchronized by a detecting feature of the closed loop circuit.

Abstract: A playback color processing circuit for a video tape recorder includes an automatic phase control loop and has two comb filters. A first comb filter. A contains a single 1H delay line for canceling adjacent-track crosstalk in the automatic phase control loop. Further, a second comb filter contains two 1H delay lines for canceling adjacent-track crosstalk in the chrominance output signal. Due to the short H/2 group delay time of the first comb filter, the chrominance output of this circuit possesses excellent phase stability and is free of hue irregularities. Due to the superior spurious output characteristics of the second comb filter, the chrominance output has good vertical resolution and can create a color picture free of vertical color smear.