Abstract: An illumination apparatus is provided with an LED array including a plurality of LEDs and a second lens array including a plurality of lenses. The LEDs and the lenses are arranged in lengthwise and crosswise directions and aligned such that a relationship between a number of the LEDs and a number of the lenses are mutually prime with each other in both lengthwise and crosswise directions. Primary illumination light from the LED array is split into a plurality of pieces of secondary illumination light by the lenses and thereafter superposed to irradiate. All of pieces of the secondary illumination light are provided with different strength peak positions of the illumination light and therefore, light having a uniform intensity can be irradiated to an irradiated region.

Abstract: An illumination light source device having a light incident opening to which illumination light from a light emitting diode is incident and a light emission opening from which the illumination light incident from the light incident opening is emitted, and having a hollow light guide for guiding the illumination light to an illumination optical system for image projection, characterized in that the light emitting diode is disposed so that the illumination light is irradiated to the light emission opening and the light emission point of the illumination light is located to be shifted to the light emission opening side with respect to the light incident opening.

Abstract: A projector is equipped with: a light emitting diode for emitting light; an image display element to which the light emitted from the light emitting diode is incident and which modulates the incident light and emits the light as image light; and an ultraviolet light incidence preventing member disposed between the light emitting diode and the image display element for preventing ultraviolet light from being incident to the image display element.

Abstract: A light source device for illumination is equipped with plural light emitting arranged in a concave shape so that respective main illumination axes thereof cross one another substantially at one point, and a light guide which has a light incidence face disposed in the neighborhood of the cross point of the main illumination axes and guides illumination light emitted from the plural light emitting diodes and incident from the light incident face to an illumination optical system for image projection.

Abstract: A reflective optical system for projectors comprises a single integral piece of transparent optical molding having at least an incident surface, an exit surface, and two or more internal reflection surfaces between the incident surface and the exit surface, each reflection power having a power, positive or negative. The reflective optical system is provided with grooves, desirably blackened grooves, formed between the internal reflection surfaces so as to block out undesirable light proceeding therein. The internal reflection surfaces are formed by coating an aluminum film on an outer wall of the transparent optical molding. The reflective optical system reflects incoming image bearing light through the incident surface on the internal reflection surfaces in turn and projects the image bearing light through the exit surface so as thereby to project an image on a remote screen.

Abstract: An asymmetric aperture diaphragm placing structure for a projection lens is provided for securing an asymmetric aperture diaphragm to a lens holder. The asymmetric aperture diaphragm includes a positioning part formed asymmetrical about the optical axis. The lens holder has a mating part adapted to engage the positioning part only in a state where the asymmetric aperture diaphragm is in a predetermined direction with respect to the optical axis. The asymmetric aperture diaphragm is secured to the lens holder in a state where the positioning part and the mating part engage each other.

Abstract: In a reflective liquid crystal projector, illumination light is separated into blue, green and red illumination light bundles. The three color illumination light bundles are respectively modulated through three reflective liquid crystal elements into blue, green and red color optical images. A first polarizing beam splitter prism directs the blue optical image to a first incident surface of a recombination prism, whereas a second polarizing beam splitter prism directs the red and green optical images to a second incident surface of the recombination prism. The three color optical images are recombined through the recombination prism into a full-color image, and the full-color image is projected through a projection lens onto a screen. The first and the second polarizing beam splitter prisms and the recombination prim are fixed merely at their bottom surfaces to a prism base plate.

Abstract: A liquid crystal projector for full-color image projection has three LCD panels as light valve device, associated with respectively primary colors, for displaying an image in a color-separated manner. An ultra high pressure mercury lamp illuminates the LCD panels through three illuminating light paths associated with respectively the primary colors. A combining prism combines image light of the primary colors from the three LCD panels, to obtain full-color image light. A laser diode emanates auxiliary illuminating light of a red color among the primary colors according to laser emission, to compensate for shortage in light intensity in the red color. A ferroelectric shaking or vibrating device vibrates the laser diode, to keep visual noise inconspicuous in the auxiliary illuminating light.

Abstract: An optical unit comprises a light source, an illumination optical system, a color-separation optical system, liquid-crystal displays, a cross dichroic prism, and a projection optical system. The projection optical system includes a first projector-lens group, a reflex mirror for perpendicularly bending an optical path of projection light, and a second projector-lens group. Illumination light emitted from the light source is parallel with a screen surface and an optical axis of the first projector-lens group. When the optical unit is rotated around a parallel axis with an optical path of the illumination light, a posture of the light source is kept in a horizontal state.

Abstract: Green, red and blue S-polarized light beams are incident into respective green, red and blue liquid crystal light valves. In the green liquid crystal light valve, the green P-polarized light beams exit from pixels for performing the white dot display, and the green S-polarized light beam exits from pixels for performing the black dot display. In red and blue liquid crystal light valves, the red and blue S-polarized light beams exits from the pixels for performing the white dot display, and the red and blue P-polarized light beams exit from the pixels for performing the black dot display. The red and blue S-polarized light beams reflect on, and the green P-polarized light beam transmits through the cross-dichroic prism, to produce a full-color image. The full-color image is projected through a projecting lens on a screen.

Abstract: An asymmetric aperture diaphragm placing structure for a projection lens is provided for securing an asymmetric aperture diaphragm to a lens holder. The asymmetric aperture diaphragm includes a positioning part formed asymmetrical about the optical axis. The lens holder has a mating part adapted to engage the positioning part only in a state where the asymmetric aperture diaphragm is in a predetermined direction with respect to the optical axis. The asymmetric aperture diaphragm is secured to the lens holder in a state where the positioning part and the mating part engage each other.

Abstract: A rotary optical filter apparatus containing an optical filter is integrated with a sirocco type cooling fan having a plurality of fan blades. The cooling fan is supported by a rotary holder of the optical filter apparatus so as to be integrally rotatable with the optical filter. The cooling fan inhales an air from its center part and discharges thus inhaled air from its outer peripheral part due to an action of the fan blades upon rotating, so as to make an airflow along the filter face and cool the optical filter.

Abstract: A rotary optical filter apparatus containing an optical filter is integrated with a sirocco type cooling fan having a plurality of fan blades. The cooling fan is supported by a rotary holder of the optical filter apparatus so as to be integrally rotatable with the optical filter. The cooling fan inhales an air from its center part and discharges thus inhaled air from its outer peripheral part due to an action of the fan blades upon rotating, so as to make an airflow along the filter face and cool the optical filter.