Abstract: An optical modulation device side lens group has different powers in the longitudinal direction and the lateral direction of a liquid crystal panel. Therefore, as the entire system of the optical projection system, the optical modulation device side lens group has different magnification in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio. At this time, a distance p between each focus or a diaphragm and the screen SC side end surface of the optical modulation device side lens group satisfies the conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.

Abstract: An object-side lens group has different power factors between the vertical and horizontal directions of a liquid crystal panel, and a projection system as a whole therefore has different focal lengths between the vertical and horizontal directions and hence different magnification factors between the vertical and horizontal directions, whereby the aspect ratio of an image on the liquid crystal panel can be set at a value different from the aspect ratio of an image projected on a screen. That is, the projection system can convert the aspect ratio, which is the ratio of the width to the height of an image. When the distance between a diaphragm and an extreme end surface of the object-side lens group on the screen side satisfies a predetermined condition, at least a certain degree of telecentricity can be provided both in the vertical and horizontal directions.

Abstract: A light modulation device side lens group has different power in the longitudinal and lateral directions and different magnifications in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio which is a ratio of width to height using the optical projection system. At this time, a distance p and a distance p? between a diaphragm and the screen SC side end surface of the light modulation device side lens group satisfies predetermined conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.

Abstract: A light modulation device side lens group has different powers in the longitudinal direction and the lateral direction of a liquid crystal panel. Therefore, as the entire system of the optical projection system, the light modulation device side lens group has different magnification in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio. At this time, a distance p between each focus or a diaphragm and the screen SC side end surface of the light modulation device side lens group satisfies the conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.

Abstract: An optical modulation device side lens group has different powers in the longitudinal direction and the lateral direction of a liquid crystal panel. Therefore, as the entire system of the optical projection system, the optical modulation device side lens group has different magnification in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio. At this time, a distance p between each focus or a diaphragm and the screen SC side end surface of the optical modulation device side lens group satisfies the conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.

Abstract: An object-side lens group has different power factors between the vertical and horizontal directions of a liquid crystal panel, and a projection system as a whole therefore has different focal lengths between the vertical and horizontal directions and hence different magnification factors between the vertical and horizontal directions, whereby the aspect ratio of an image on the liquid crystal panel can be set at a value different from the aspect ratio of an image projected on a screen. That is, the projection system can convert the aspect ratio, which is the ratio of the width to the height of an image. When the distance between a diaphragm and an extreme end surface of the object-side lens group on the screen side satisfies a predetermined condition, at least a certain degree of telecentricity can be provided both in the vertical and horizontal directions.

Abstract: A projection optical system which, when projecting an image of an optical modulator onto a projection surface on an enlarged scale, differs the aspect ratio of the image of the optical modulator and the aspect ratio of the image projected onto the projection surface, and includes, in order from the projection surface, a first group which is an enlargement optical system; a second group includes an adjustment optical component with a surface rotationally asymmetrical to an optical axis, when defining at least one direction of the vertical direction and the horizontal direction of the optical modulator as an adjustment direction in which conversion adjustment using compression or extension is performed, the adjustment optical component having at least one optical system which differs in power between the adjustment direction and another direction; and a third group which has a correction optical component with a surface rotationally symmetrical to the optical axis.

Abstract: A projector includes: a light source which emits laser light; a first diffusing section which diffuses the laser light emitted from the light source to emit a first diffused light; and a light modulation device which modulates the first diffused light emitted from the first diffusing section. The light modulation device includes a second diffusing section which diffuses the first diffused light emitted from the first diffusing section to emit a second diffused light, and diffusion intensity distribution of the second diffused light emitted from the second diffusing section is distribution which is consecutive around a central axis of the second diffused light.

Abstract: A method and an apparatus for melting a metallic material in the form of a pile of elongate metal ingots, wherein the ingot pile are pre-heated in a horizontal pre-heating chamber while the pile is moved from its one end to the other end, and the pre-heated pile at the other end is pushed into a melting chamber which communicates with the pre-heating chamber and extends vertically downwardly from the other end of the pre-heating chamber, whereby the pile is turned sideways before falling down into the melting chamber, with a result of collapse of the pile into the individual metal ingots in the melting chamber.