Abstract: There is a need for providing a projection optical system that is appropriate for maintaining high resolution with low distortion, miniaturizing a reflector, decreasing the number of reflectors, and decreasing the depth and the bottom (or top) of a display used for a rear projection television, for example. The projection optical system according to the invention enlarges and projects images from a primary image surface existing at a reducing side to a secondary image surface existing at an enlarging side. The projection optical system has a first optical system L11 and a second optical system L12. The first optical system L11 forms an intermediate image (position II) of the primary image surface. The second optical system L12 has a concave reflector AM1 that forms the secondary image surface resulting from the intermediate image. A light beam travels from the center of the primary image surface and to the center of the secondary image surface and crosses an optical axis.

Abstract: In one inventive aspect, a multilayer ceramic capacitor is provided. The capacitor comprises dielectric layers and internal electrode layers alternately stacked. Two of the internal electrode layers that are located outermost and/or at least one of the internal electrode layers that is located inside each outermost internal electrode layer are substantially oxidized and do not function as electrodes. The capacitance of the multilayer ceramic capacitor depends on the unoxidized internal electrode layers other than the oxidized ones. In another inventive aspect, a method for manufacturing a multilayer ceramic capacitor is provided. The method comprises forming green dielectric layers, forming green internal electrode layers, preparing a green ceramic chip, forming green external electrodes, and firing the green ceramic chip.

Abstract: In one inventive aspect, a multilayer ceramic capacitor is provided, in which occurrence of cracks can be prevented even when temperature of the capacitor itself is increased. Non-flat portions are formed in both sides in a width direction of each of inner electrode layers. In addition, the non-flat portions comprise regions substantially changed into oxide regions, therefore a thermal expansion coefficient of the non-flat portions can be decreased so that stress due to difference in thermal expansion coefficient to non-flat portions can be reduced, and the stress can be dispersed in accordance with curvature or inclination of the non-flat portions. That is, stress generated when temperature of the capacitor itself is increased is decreased and dispersed, thereby occurrence of cracks due to the stress can be prevented in side margins of the ceramic chip.

Abstract: A projection optical system and an image projection apparatus that are small in size and can achieve projection with a wide angle while a good image forming performance is assured includes a first lens group having a negative refracting power and a second lens group also having a negative refracting power. The first and second lens groups are arranged in order from the projection side. The first lens group includes a negative meniscus lens that has a concave surface directed to the projection side and formed as an aspherical reflecting surface.

Abstract: A projection optical system and an image projection apparatus that are small in size and can achieve projection with a wide angle while a good image forming performance is assured includes a first lens group having a negative refracting power and a second lens group also having a negative refracting power. The first and second lens groups are arranged in order from the projection side. The first lens group includes a negative meniscus lens that has a concave surface directed to the projection side and formed as an aspherical reflecting surface.

Abstract: A zoom lens system has, in order from an enlargement side, a first lens unit having negative optical power, a second lens unit having positive optical power, a third lens unit having positive optical power, a fourth lens unit having negative optical power, including an aperture stop, a fifth lens unit having positive or negative optical power, and a sixth lens unit having positive optical power. Zooming is achieved by varying the first to fifth variable distances between the lens units. The third and fifth lens units move from the enlargement side to the reduction side during zooming from the telephoto end to the wide-angle end. The zoom lens system is substantially telecentric toward the reduction side.

Abstract: A projection system that is capable of providing a high-performance projection system and producing a high contrast projection image by using an optical modulation element, which can be positioned a predetermined distance away from an illumination optical system and a projection optical system. The optical modulation element is capable of modulating light received from the illumination optical system and projecting the modulated light to a projection optical system in the direction of a projection surface.

Abstract: A zoom lens system has, from an enlargement side, a first lens unit having a negative optical power, a second lens unit having a positive optical power and disposed on the image side of the first lens unit with a first variable distance secured in between, a third lens unit having a positive optical power and disposed on the image side of the second lens unit with a second variable distance secured in between, a fourth lens unit having a negative optical power, disposed on the image side of the third lens unit with a third variable distance secured in between, and including an aperture stop, a fifth lens unit having a positive or negative optical power and disposed on the image side of the fourth lens unit with a fourth variable distance secured in between, and a sixth lens unit having a positive optical power and disposed on the image side of the fifth lens unit with a fifth variable distance secured in between. Zooming is achieved by varying the first to fifth variable distances.

Abstract: A projection optical apparatus has a light source for emitting light, an illumination optical system for emitting as illumination light the light radiated from the light source, a Digital Micromirror Device™, having a plurality of micromirrors, for separating the illumination light into signal light and unnecessary light by varying, in accordance with a signal, the angles at which the individual micromirrors reflect the illumination light shone thereon, a total internal reflection prism composed of a first prism for totally reflecting and thereby directing the illumination light exiting from the illumination optical system to the Digital Micromirror Device™ and a second prism for transmitting the signal light reflected from the Digital Micromirror Device™, and a projection optical system for projecting the signal light transmitted through the second prism onto a projection surface.

Abstract: A projection system that is capable of providing a high-performance projection system and producing a high contrast projection image by using an optical modulation element, which can be positioned a predetermined distance away from an illumination optical system and a projection optical system. The optical modulation element is capable of modulating light received from the illumination optical system and projecting the modulated light to a projection optical system in the direction of a projection surface.

Abstract: A projection optical system has, from the enlargement side to the reduction side, a first, a second, and a third lens unit, and an aperture diaphragm. The negatively-powered first lens unit includes only a negative lens element and has at least one aspherical surface. The positively-powered second lens unit includes at least one positive lens element. The positively-powered third lens unit includes a lens element. The aperture diaphragm is disposed at the front focal point of the third lens unit. The lens element of the third lens unit is made of a material of which anomalous partial dispersibility and Abbe number are defined.