Abstract: An optical element includes a mirror surface configured to transmit certain part of incident light and to reflect the other part of the incident light. The mirror surface has a first region and a second region. The first region includes a first polarization conversion layer configured to convert a polarization direction of incident light incident on the first region from one linear polarization into a different linear polarization. A region of the optical element from which light transmitted through the first region is emitted includes a second polarization conversion layer configured to convert a polarization direction of the light transmitted through the first region from the different linear polarization into the one linear polarization.

Abstract: An illumination apparatus includes multiple liquid crystal panels, a polarization-state adjusting element, and a cross dichroic prism. A green component light includes a central-wavelength component light, a short-wavelength component light, and a long-wavelength component light. The polarization-state adjusting element separately adjusts a polarization state of the central-wavelength component light and each of polarization states of the long-wavelength component light and the short-wavelength component light.

Abstract: The lighting unit includes the DMDs (80R), (80G), and (80B). The lighting unit also includes: the prisms (50) and (60) combining the light emitted from the DMDs (80R), (80G), and (80B); and the light modulating optical device (90G). The incident light including the green component light and the yellow component light enters the light modulating optical device (90G). The light modulating optical device (90G) transmits the green component light and changes a transmittance of the yellow component light depending on a change of a molecular state. Light having emitted from the light modulating optical device (90G) enters the DMD (80G), which corresponds to the incident light.

Abstract: An optical element includes: a first dichroic mirror; and a pair of second dichroic mirrors, wherein the first dichroic mirror includes a first mirror surface and a first main surface; the pair of second dichroic mirrors each includes a second mirror surface and a second main surface; one second dichroic mirror of the pair of second dichroic mirrors is disposed on the first mirror surface in such a way that the second mirror surface is perpendicular to the first mirror surface; the other second dichroic mirror of the pair of second dichroic mirrors is disposed on the first main surface in such a way that the second mirror surface is perpendicular to the first main surface; and a gradation process for adjusting a spectral characteristic within the first mirror surface is applied only for the first mirror surface.

Abstract: A projection display apparatus includes: an element controller that controls an imager to display a maximum light amount image and a minimum light amount image; a setting unit that sets a light amount threshold value used to detect pointing light emitted from a pointing device; and a specifying unit that specifies a light amount of the pointing light overlapping the minimum light amount image, based on a picked-up image, and to specify a light amount of the maximum light amount image, based on the picked-up image, wherein the setting unit sets the light amount threshold value, based on the specified light amount of the pointing light and the specified light amount of the maximum light amount image.

Abstract: An illumination apparatus includes multiple liquid crystal panels, a polarization-state adjusting element, and a cross dichroic prism. A green component light includes a central-wavelength component light, a short-wavelength component light, and a long-wavelength component light. The polarization-state adjusting element separately adjusts a polarization state of the central-wavelength component light and each of polarization states of the long-wavelength component light and the short-wavelength component light.

Abstract: A projection display apparatus includes: a red imager; a green imager; a blue imager; a polarization adjusting element; a color combining unit; and a controller. A superimposed component light enters the polarization adjusting element together with the fourth color component light. The polarization adjusting element transmits the superimposed component light, whereas transmitting the fourth color component light by adjusting the polarization of the fourth color component light in accordance with switching between a low voltage applied state and a high voltage applied state. The controller controls re-orienting operation of applying a high voltage to the polarization adjusting element.

Abstract: An illumination apparatus includes; a first solid-state light source, a second solid-state light source, a first arrangement member provided with a first arrangement surface, a second arrangement member provided with a second arrangement surface, an optical unit configured to reduce a dispersion angle of a light beam. The first solid-state light source emits a light beam having a first directivity. The second solid-state light source emits a light beam having a second directivity greater than the first directivity. A distance from the second arrangement surface to the second light-entering surface is longer than a distance from the first arrangement surface to the first light-entering surface.

Abstract: An image projecting unit of a projector includes a light source; a polarization control element which controls a polarization direction of light emitted from the light source; and a projecting unit which projects the image light that passed through the optical modulation element. The control unit detects a deterioration state of the polarization control element based on the projected image which is taken by an image-taking unit when a test image representing a single color throughout a screen is projected.

Abstract: A projection display apparatus is placed on an installation surface forming a horizontal plane and projects an image onto a projection plane provided on a horizontal plane. The projection display apparatus includes: an imager that modulates the light emitted from a light source; an projection unit that projects the light emitted from the imager onto the projection plane; and an acoustic device that outputs a sound in the vertical direction.

Abstract: A projection display apparatus includes a housing member that houses a light source, an imager that modulates light emitted from the light source, and a projection unit that projects light emitted from the imager onto a projection plane, wherein the projection unit has a concave mirror that reflects the light emitted from the imager to the projection plane side, and the housing member pivotally supports the concave mirror along a circumference of a virtual circle formed by a virtual extension line of the concave mirror.

Abstract: A projection display apparatus comprising: a housing member that accommodates an illumination optical unit; a projection optical unit; and a cooling unit, wherein the housing member includes a layout space in a virtually columnar shape having a bottom that is a circumscribed circle of the projection optical unit in a cross sectional view vertical to the projection optical unit; the layout space includes a first layout space in a substantially conical shape and a second layout space excluding the first layout space; the projection optical unit is provided in the first layout space; and at least a part of the illumination optical unit and the cooling unit is provided in the second layout space; and the illumination optical unit and the cooling unit are disposed in a symmetrical positional relationship with respect to the projection optical unit.

Abstract: An illumination apparatus includes: a red light valve configured to modulate red component light according to a red input signal; a green light valve configured to modulate green component light according to a green input signal; a blue light valve configured to modulate blue component light according to a blue input signal; a fourth color light valve configured to modulate a fourth color component light; and a color combiner configured to combine light emitted from the red light valve, the green light valve and the blue light valve. The fourth color component light emitted from the fourth color light valve enters a certain light valve, which is any one of the red light valve, the green light valve and the blue light valve.

Abstract: A projection display apparatus includes a housing member containing a light source, an imager that modulates light emitted from the light source, and a projection unit that projects the light emitted from the imager on a projection surface. The projection display apparatus includes: a movement mechanism that moves an optical unit configured by the light source, the imager, and the projection unit, in a direction perpendicular to the projection surface while maintaining a positional relationship among the light source, the imager, and the projection unit.

Abstract: A dielectric ceramic composition includes a compound having perovskite type crystal structure shown by a general formula ABO3, where A is at least one selected from Ba, Ca and Sr, and B is at least one selected from Ti and Zr. The dielectric ceramic composition includes, as subcomponents, an oxide of RA (Dy, Gd and Tb); an oxide of RB (Ho and Y); an oxide of RC (Yb and Lu); Mg oxide and an oxide including Si in terms of RA2O3, RB2O3, RC2O3, Mg and Si, respectively. Also, when contents of the oxide of RA, RB and RC with respect to 100 moles of the compound are defined as “?”, “?” and “?”, respectively, they satisfy relations of 1.2?(?/?)?5.0 and 0.5?(?/?)?10.0.

Abstract: The illumination apparatus includes a color separator configured to separate a white light beam, emitted from a white light source, into a plurality of color component light beams, a plurality of imagers each configured to modulate a corresponding one of the plurality of color component light beams separated by the color separator and a polarization modulator provided on a light incident side of one imager included in the plurality of imagers. The polarization modulator modulates a polarization direction of a modulation-object light beam which is part of a color component light beam guided to the one imager.

Abstract: A sand drift prevention method in which a plurality of columnar sandbags made of a tubular knit fabric are placed so as to cross over one another, and in such a pitch that 3 to 30 sandbags are disposed for every ten meters, and in which the cross-sectional area of each of the columnar sandbags is 10 to 400 cm2. A method of forming and improving the vegetation in sandy soil in which drift of sand is prevented by the sand drift prevention method, a plant desired to grow is grown in the sandy soil surface exposed as being surrounded by columnar sandbags placed so as to cross over one another. A tubular knit fabric for a columnar sandbag employed in these methods, and, in particular, the tubular knit fabric knitted by use of a polylactic-acid fiber.

Abstract: A projection display apparatus displays an image on a projection surface in cooperation with a second projection display apparatus. The projection display apparatus includes: a detection unit that detects the position of the second projection display apparatus; and a switching unit that performs switching between a stack display mode and a tile display mode on the basis of the position of the second projection display apparatus. In the stack display mode, an image projected by the projection display apparatus and an image projected by the second projection display apparatus are displayed on a projection surface in a stacked manner. In the tile display mode, an image projected by the projection display apparatus and an image projected by the second projection display apparatus are displayed on a projection surface in a side-by-side manner.

Abstract: A light source device includes: a reference light source that emits reference color component light of a plurality of colors; an excitation light source that emits excitation light for supplemental color component light; a luminous body member including a luminous body that emits the supplemental color component light in response to the excitation light; and a combining unit that combines the reference color component light of the plurality colors and the supplemental color component light in such a way as to superimpose the supplemental color component light on light paths of the reference color component light of the plurality of colors.

Abstract: A fluorine insolubilizer capable of sufficiently insolubilizing fluorine within a short time contains calcium hydrogen phosphate dihydrate in an amount of 95-40 mass % and apatite hydroxide in an amount of 5-60 mass % for a total of 100 mass %.