Abstract: There is provided a projection optical system (1) that projects from a first image plane on a reducing side to a second image plane on an enlargement side, including a first refractive optical system (11) that includes eight lenses (L1) to (L8) and forms a first intermediate image (31) on the enlargement side using light that is incident from the reducing side, a second refractive optical system (12) that includes six lenses (L9) to (L14) and forms the first intermediate image (31) on the reducing side into a second intermediate image (32) on the enlargement side, and a first reflective optical system (20) that includes a first reflective surface (21a) with positive refractive power that is positioned closer to the enlargement side than the second intermediate image (32).

Abstract: An optical system (1) includes: a first lens system (10) that emits light (51a) of a visible light band incident from a light modulating device (60) side toward a projection side; and an optical device (30) that separates proximate light (52b), which is adjacent to the visible light band and is light of a non-visible light band that is incident on the first lens system (10) from the projection side, from an optical path (41) of the first lens system (10) and outputs toward an image pickup device (70) side.

Abstract: A projection optical system (2) projects from a DMD (7) on a reducing side onto a screen (9) on an enlargement side, and includes: a first refractive optical system (10) that forms a first intermediate image (51) on the enlargement side using light incident from the reducing side; a second refractive optical system (20) that forms the first intermediate image (51) on the reducing side into a second intermediate image (52) on the enlargement side; and a first reflective optical system (30) including a first reflective surface (31a) with positive refractive power that is positioned on the enlargement side of the second intermediate image (52), wherein the second refractive optical system (20) includes a first focus lens group (61) that moves when focusing is carried out, and the first focus lens group (61) includes at least one lens (L13) included in the second refractive optical system (20).

Abstract: Disclosed are a white LED lighting device and an optical lens used in it. The white LED lighting device comprises a white LED and an optical lens. The white LED includes: a LED chip which emits blue light; and a fluorescent material which is excited by emission light of the LED chip and converts a wavelength into fluorescence of a complementary color of blue. The optical lens is formed with a scattering light guide which is given uniform scattering power in terms of a volume. The scattering light guide includes scattering particles for the scattering efficiency in a short wavelength range of light to be higher than that in a long wavelength range of light.

Abstract: A lens barrel of the present invention comprises: first and second guide shafts arranged parallel to an optical axis X and provided in one of adjacent lens holding frames; first and second guide receiving holes formed in another of the adjacent lens holding frames for allowing the first and second guide shafts to be inserted therethrough and guided by the first and second guide shafts respectively; a first urging means of urging the one and the another of the adjacent lens holding frames along the direction of the optical axis; and a second urging means to rotate another of the adjacent lens holding frames in a circumferential direction of the first guide shaft. The first guide receiving hole is guided by the first guide shaft at two positions that are spaced apart from each other in the direction of the optical axis.

Abstract: Provided is an optical element which suppresses generation of glare and a dark section and is applicable to planar light emission having improved light efficiency. A light emitting device is also provided. A light emitting device is provided with: a light transmitting member having a light inputting section having light inputted thereto, a first light guide section which guides light inputted to the inputting section to a reflecting surface, the reflecting surface which is arranged on the first light guide section on the side opposite to the light inputting side and totally reflects light which forms one linear path among inputted light, and a second light guide section which guides reflected light; and a light emitting member which inputs light to the inputting section.

Abstract: Disclosed are a light emitting device and a light emitting element that can decrease fabrication difficulties, while improving lighting efficiency and controlling the distribution of intensity that occurs in the emitted light. A light emitting device comprises a rod-shaped light guide, an LED that inputs light to the light guide, and a prism that changes the direction of light input from the lengthwise end of the light guide, and emits redirected light from a light exit surface that is disposed opposite the prism. The light emitting device is constituted so that an input lens is formed at the lengthwise end of the light guide as a parallel light forming body to make light exiting from the LED toward the light guide nearly parallel light, and the LED is shifted from the center axis of the light guide toward the side closer to the prism, or toward the side away from the prism, and thus said nearly parallel light is directed to the exit surface of the light guide or to the prism.

Abstract: A lens barrel of the present invention comprises: first and second guide shafts arranged parallel to an optical axis X and provided in one of adjacent lens holding frames; first and second guide receiving holes formed in another of the adjacent lens holding frames for allowing the first and second guide shafts to be inserted therethrough and guided by the first and second guide shafts respectively; a first urging means of urging the one and the another of the adjacent lens holding frames along the direction of the optical axis; and a second urging means to rotate another of the adjacent lens holding frames in a circumferential direction of the first guide shaft. The first guide receiving hole is guided by the first guide shaft at two positions that are spaced apart from each other in the direction of the optical axis.

Abstract: A zoom lens system has a combined focal length fw at the wide angle end and includes, in order from an object side, a first lens group with positive refractive power and combined focal length f1; a second lens group with negative refractive power; a third lens group with positive refractive power; a fourth lens group with positive refractive power; and a fifth lens group with positive refractive power and including, in order from the object side, a negative biconcave lens with focal length f51 and a positive biconvex lens with focal length f52, the negative biconcave lens and the positive biconvex lens disposed with an air space shorter than a center thickness of the negative biconcave lens in between and both surfaces of the positive biconvex lens being aspherical. The system satisfies the following conditions: 13.5<f1/fw<17.5, and 1.0<|f51/f52|<1.5.

Abstract: A projector lens system is provided. The projector lens system comprising, in order from a screen side thereof: a first negative lens that is made of resin and is convex on the screen side; a first positive lens that is made of glass and is biconvex; a stop; a cemented lens that has negative refractive power and is composed, in order from the screen side, of a second negative lens that is made of glass and a second positive lens that is made of glass; and a third positive lens that is made of resin, wherein a refractive index n1 of the first negative lens, a refractive index n2 of the first positive lens, a refractive index n32 of the second positive lens, and a refractive index n4 of the third positive lens satisfy the following conditions: 1.45?n1?1.60; 1.45?n4?1.60; 0.16?n2?n1?0.31; 0.16?n32?n4?0.31; 0.95?n1/n4?1.05; and 0.95?n2/n32?1.05.

Abstract: A light guiding body of this invention comprises a light incident surface arranged on one end side of a light guide member, a light reflecting surface arranged on another end side of the light guide member opposite to the light incident surface across the light guide member, and a light emitting surface, arranged on a side surface of the light guide member between the light incident surface and the light reflecting surface, through which light input from the light incident surface into the light guide member passes to outside, in which the light guide member is formed as a solid body and at least a part of the light guide member is made from light scattering guide material which contains light scattering particles.

Abstract: Provided are an optical element and a light-emitting device with which the illuminated area can be expanded in spite of a small light-emitting area, and that also enable the device to be downsize. The light-emitting device is equipped with sheet-like light-guide sections (a first light-guide section and a second light-guiding section) for guiding light, and a light-emitting member for emitting light. The second light-guide section has a prism section with a saw tooth-like cross-section for changing the direction of the light guided to one of its surfaces. In the prism section, the angle of incidence at which parallel light guided to the second light guide section enters reflective surface of saw teeth at positions away from the LED is set to be greater than the angle of incidence (?) at which the light enters the reflective surface of the saw teeth at the side toward the LED.

Abstract: To provide a light emitting device that realizes a similar light distribution state to that of a conventional incandescent light bulb even though the light emitting device has a structure with a light emitting element such as an LED placed on a substrate. In the light emitting device in which the LED is placed on the substrate, the light emitting device includes the light guiding member, into which light emitted from the LED enters, while the light guiding member having the launching surface (i.e., the facing-substrate launching surface and the side launching surface) from which the entered light is launched. Meanwhile, the launching surface has the facing-substrate launching surface including a total reflection surface for totally reflecting light incident in the launching surface at a critical angle, in a direction tilted toward a side of the substrate than a direction perpendicular to the optical axis of the light emitting device.

Abstract: Provided is a light emitting device which can uniformly diffuse and radiate light from all the regions of the globe of an LED bulb without deteriorating light transmission efficiency. A light emitting device is provided with a light scattering/guiding globe and an LED which is disposed on one end of the light scattering/guiding globe. The light scattering/guiding globe is a body with no air released from the inside and is composed of a light scattering/guiding material having light scattering particles contained therein. The globe has the bottom surface on the side of the LED, and is provided with a first light incoming surface as a first hollow section, which is formed in a circular cone shape in the light outputting direction from the bottom surface.

Abstract: The present invention provides an illumination lens which suppresses a change of an illuminance distribution following a change of an arrangement position of a light source with respect to the illumination lens. A reflection surface and emission surface of the illumination lens are configured to refract and emit, in the emission surface, second illumination light and third illumination light with refracting power of different signs. By changing an illuminance distribution of third illumination light to cancel the change of an illuminance distribution of the second illumination light when a light source is moved, it is possible to suppress the change of the illuminance distribution small even when the light source is moved back and forth.

Abstract: A projection lens system has first, second and third lens groups. The first lens group with combined focal length f1 has, in order from a screen side, a first negative meniscus lens, a second negative meniscus lens with focal length f12, refractive index n12 and screen side surface radius of curvature R12a, and a negative biconcave lens with focal length f13. A second lens group consists of a positive biconvex lens with a radius of curvature R21b of a surface on a light modulator side of the positive biconvex lens. The system satisfies the following conditions: 1.0<|f12/f1|<4.0; 5.0<|f13/f1|<9.0; 1.75<n12<2.0; and 0.1<|R21b/R12a|<0.8.

Abstract: There is provided a lens system (10) that projects projected light onto a screen (6) and includes, in order from the screen (6) side thereof, a first lens (L11) that is a meniscus-type lens with negative refractive power and is convex on the screen (6) side; a second lens (L12), a third lens (L13) and a fourth lens (L14) that are meniscus-type lenses with positive refractive power and are concave on the screen (6) side. In addition, the effective diameter of a concave surface (S6) of the third lens (L13) is larger than the effective diameter of the concave surface (S3) of the second lens (L12), the effective diameter of the concave surface (S8) of the fourth lens (L14) is larger than the effective diameter of the concave surface (S6) of the third lens (L13), and part of the convex surface (S7) of the third lens (L13) and part of the concave surface (S8) of the fourth lens (L14) are located in a shared space along the optical axis.

Abstract: Disclosed are a white LED lighting device and an optical lens used in it. The white LED lighting device comprises a white LED and an optical lens. The white LED includes: a LED chip which emits blue light: and a fluorescent material which is excited by emission light of the LED chip and converts a wavelength into fluorescence of a complementary color of blue. The optical lens is formed with a scattering light guide which is given uniform scattering power in terms of a volume. The scattering light guide includes scattering particles for the scattering efficiency in a short wavelength range of light to be higher than that in a long wavelength range of light.