Abstract: There is provided a lens system composed, in order from an enlargement side, of a first lens group with positive refractive power and a second lens group with positive refractive power, wherein when zooming from a telephoto end to a wide-angle end, a distance between the first lens group and the second lens group decreases and a distance between the second lens group and a conjugate plane on a reduction side increases. The second lens group includes, closest to an enlargement side thereof, a lens with a second end surface that is concave on the enlargement side, and the first lens group includes a lens with an effective diameter of a first end surface closest to the reduction side that is larger than a maximum diameter in the second lens group.

Abstract: A lens system (10) for image pickup includes, in order from an object side (11), a first lens group (G1) that has negative refractive power and is fixed during focusing, a second lens group (G2) that has positive refractive power and moves during focusing, a third lens group (G3) that has positive refractive power and is fixed during focusing, and a fourth lens group (G4) that has a stop disposed on the object side, is disposed closest to an image plane side, has positive refractive power, and is fixed during focusing. The first lens group includes a first lens (L11) with positive refractive power that is disposed closest to the object side.

Abstract: An optical filter includes: a base material; and a plurality of light scattering particles mixed into the base material. The plurality of light scattering particles include a plurality of scattering elements which differ from each other in a manner of appearance of “scattered light intensity distribution for respective wavelengths”. With such a configuration, it is possible to provide the optical filter which is an optical filter can be manufactured without using a method which roughens the surface of the optical filter and is an optical filter for soft focusing which can suppress the occurrence of an iris phenomenon. It is also possible to provide a lens unit which can suppress the occurrence of an iris phenomenon.

Abstract: A lens system (10) for image pickup includes, in order from an object side (11): a first lens group (G1) that has negative refractive power and is fixed during focusing; a second lens group (G2) that has positive refractive power and moves during focusing; a third lens group (G3) that has positive refractive power and is fixed during focusing; and a fourth lens group (G4) that has a stop disposed on the object side, is fixed during focusing, has positive refractive power, and is disposed closest to an image plane side (12). The first lens group includes a first lens (L11) with positive refractive power that is disposed closest to the object side and a terminal lens (L13) with negative refractive power disposed closest to the image plane side.

Abstract: A lens system (10) for image pickup includes, in order from the object side (11), a first lens group (G1) that has negative refractive power and is fixed during focusing, a second lens group (G2) that has positive refractive power and moves during focusing, a third lens group (G3) that has positive refractive power and is fixed during focusing, and a fourth lens group (G4) that has a stop disposed on the object side, is disposed closest to the image plane, has positive refractive power, and is fixed during focusing. The second lens group may include a meniscus-type single lens (L21) or cemented lens with positive refractive power that is concave on the object side.

Abstract: A lens system (10) for image pickup includes, in order from an object side (11), a first lens group (G1) that has negative refractive power and is fixed during focusing, a second lens group (G2) that has positive refractive power and moves during focusing, a third lens group (G3) that has positive refractive power and is fixed during focusing, and a fourth lens group (G4) that has a stop disposed on the object side, is disposed closest to an image plane side, has positive refractive power, and is fixed during focusing. The first lens group includes a first lens (L11) with positive refractive power that is disposed closest to the object side.

Abstract: Provided is an illumination module capable of preventing a light exit surface from being darker along peripheral edge portions as though having borders. An illumination module (1) includes: a light guiding plate (20), which has an end surface (21) and a first principal surface (23); a light source (30) configured to emit light that enters the end surface (21); and a diffusion plate (50), which has alight incident surface (55) and a light exit surface (56). The diffusion plate (50) includes a protruding part (51), which protrudes toward the light guiding plate (20) side and the light source (30), which is positioned so as to face a peripheral edge portion (26) on the end surface (21) side of the light guiding plate (20), and which has a light incident surface (52) into which light exiting the peripheral edge portion (26) enters.

Abstract: Provided is an illumination module capable of preventing a light exit surface from being darker along peripheral edge portions as though having borders. An illumination module (1) includes: a light guiding plate (20), which has an end surface (21) and a first principal surface (23); a light source (30) configured to emit light that enters the end surface (21); and a diffusion plate (50), which has alight incident surface (55) and a light exit surface (56). The diffusion plate (50) includes a protruding part (51), which protrudes toward the light guiding plate (20) side and the light source (30), which is positioned so as to face a peripheral edge portion (26) on the end surface (21) side of the light guiding plate (20), and which has a light incident surface (52) into which light exiting the peripheral edge portion (26) enters.

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 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: 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: 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: 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: 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 method of producing soft porcelain wherein one raw material of the porcelain, .beta.-calcium pyrophosphate, is obtained by heating uniformly bone phosphate, which is a by-product of gelatin production from cattle bones, at a temperature of 1,000.degree. to 1,250.degree. C so as to completely convert it to .beta.-calcium pyrosphosphate, and a green body consisting of the thus obtained .beta.-calcium pyrophosphate, limestone, sericite, kaolin, feldspar and quartz is prepared and then is subjected to oxidation firing.