Abstract: The polarization beam splitter of the present invention includes a polarized beam splitting layer having a structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, light having a chiefly polarized component parallel to the first direction is transmitted therethrough, and light having a chiefly polarized component parallel to the second direction is reflected.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure.

Abstract: In the conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. In a conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. The polarization beam splitter of the present invention is a polarization beam splitter having a polarized beam splitting layer having structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, chiefly light of a polarized component parallel to the first direction is transmitted therethrough, and chiefly light of a polarized component parallel to the second direction is reflected.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure. The first periodic structure and the second periodic structure transmit light having first polarization direction and reflect light having second polarization direction orthogonal to the first direction.

Abstract: In a conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. The polarization beam splitter of the present invention is a polarization beam splitter having a polarized beam splitting layer having structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, chiefly light of a polarized component parallel to the first direction is transmitted therethrough, and chiefly light of a polarized component parallel to the second direction is reflected.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure.

Abstract: A camera capable of automatically detecting a main object in a sensed image. A distance distribution generation unit discriminates a plurality of areas in the sensed image on the basis of a predetermined condition, and a main object area determination unit automatically determines the main object area out of the discriminated areas. If the determined main object area is different from the area where an operator intends to focus on and the operator wishes to change the main object area, a new main object area is selected in accordance with an instruction inputted from a main object area changing unit. Then, the camera focuses on the selected main object area.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure.

Abstract: In the conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. The polarization beam splitter of the present invention is a polarization beam splitter having a polarized beam splitting layer having structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, chiefly light of a polarized component parallel to the first direction is transmitted therethrough, and chiefly light of a polarized component parallel to the second direction is reflected.

Abstract: When light from a reflection image display element is incident on a polarization split surface at an angle other than 45°, leakage light that decreases the contrast of an image is produced.

Abstract: An image display apparatus includes a light source for supplying illumination light, a reflection type display element for modulating the illumination light into image light by reflecting the light, an illumination optical system for guiding the illumination light to the reflection type display element, and a projection optical system for guiding the image light to an observer. The image light is incident on the projection optical system via at least a portion of the illumination optical system. The illumination optical system has a part, in an area where both the illumination light and the image light pass, which changes an optical action depending on a state of incident light. The part acts to deflect the illumination light to decrease an incident angle with respect to the reflection type display element as compared with a case where the part does not exist.

Abstract: When light from a reflection image display element is incident on a polarization split surface at an angle other than 45°, leakage light that decreases the contrast of an image is produced.

Abstract: A focus state detection apparatus for detecting focus state on the basis of signals outputted from a pair of area sensors each of which is configured in two dimension in accordance with an image of an object passing through an optical system and formed on the pair of area sensors. Each of the pair of area sensors is divided into a plurality of areas each of which can be controlled independently, and charging pixels of the area sensors is controlled by each pair of corresponding divided areas of the area sensors.

Abstract: An anti-fog article is obtained by coating a substrate with an anti-fog coating material to form thereon an anti-fog coating film that is hydrophillic, moisture-absorptive, insoluble and excellent in surface hardness. The anti-fog coating material contains a polyacrylic acid compound, polyvinyl alcohol and acetylacetone, and optionally sodium silicate.

Abstract: An anti-fog article is obtained by coating a substrate with an anti-fog coating material to form thereon an anti-fog coating film that is hydrophillic, moisture-absorptive, insoluble and excellent in surface hardness. The anti-fog coating material contains a polyacrylic acid compound, polyvinyl alcohol and acetylacetone, and optionally sodium silicate.

Abstract: An image display apparatus includes a light source for supplying illumination light, a reflection type display element for modulating the illumination light into image light by reflecting the light, an illumination optical system for guiding the illumination light to the reflection type display element, and a projection optical system for guiding the image light to an observer. The image light is incident on the projection optical system via at least a portion of the illumination optical system. The illumination optical system has a part, in an area where both the illumination light and the image light pass, which changes an optical action depending on a state of incident light. The part acts to deflect the illumination light to decrease an incident angle with respect to the reflection type display element as compared with a case where the part does not exist.

Abstract: A focus state detection apparatus for detecting focus state on the basis of signals outputted from a pair of area sensors each of which is configured in two dimension in accordance with an image of an object passing through an optical system and formed on the pair of area sensors. Each of the pair of area sensors is divided into a plurality of areas each of which can be controlled independently, and charging pixels of the area sensors is controlled by each pair of corresponding divided areas of the area sensors.

Abstract: A camera, or an underwater camera in particular, includes a photo-taking optical unit for photo-taking an object, and a viewfinder optical unit for observing the object, wherein an antifogging film is applied to an inner side of an optical member which is disposed in an optical path of at least one of the photo-taking optical unit and the viewfinder optical unit and which comes into contact with an external medium relative to the camera.

Abstract: Disclosed herein is an anti-fogging coating material comprising at least one selected from the group consisting of an inorganic alkoxide, a hydrolysate of the inorganic alkoxide and a polycondensate of the hydrolysate of the inorganic alkoxide, a polyacrylic, and polyvinyl alcohol.

Abstract: A focus detecting device of the kind using an area sensor which has a plurality of focus detecting areas necessitates setting a correction value for every one of the focus detecting areas and storing all the correction values thus obtained, whereas, according to the invention, the correction value for each of the focus detecting areas of the area sensor is obtained by an arithmetic operation using, as variables, two parameters indicative of the position of the area, so that a focus detecting device can be arranged to obviate the necessity of storing all the correction values for the respective focus detecting areas.