Ricoh Company, Ltd.

Atsushi Takaura

Kazuhiro Fujita

Kazuya Miyagaki

Nobuo Sakuma

Takanobu Osaka

Issei Abe

Yasuyuki Takiguchi

Toshiaki Tokita

Hiroyuki Sugimoto

Toshiharu Murai

Kenji Namie

Koji Masuda

Koichi Kudo

Masahiro Itoh

Yasuhiro Nihei

Yasunobu Youda

Kenji Kameyama

Takeshi Ueda

Yasuo Sakurai

Nobuaki Ono

Yumi Matsuki

Ikuo Katoh

Osamu Nagase

Yoshitsugu Kohno

Akihiro Yamakage

Masanori Kobayashi

Hiroyoshi Funato

Taku Amada

Kenichi Shimizu

Asato Tamura

Toshimichi Hagiya

Yukiko Hirano

In a projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source, the projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.

Projection optical system, magnification projection optical system, magnification projection apparatus, and image projection apparatus

A moving-member detecting device includes an image acquiring unit and a speed calculating unit. The image acquiring unit includes a light source configured to emit a light beam to a detecting position of a moving member; an area sensor configured to acquire image data of a one- or two-dimensional image; and an area-sensor control unit configured to acquire the image data. The image acquiring unit is configured to acquire pieces of image data of the moving member at first and second positions, respectively, in a moving direction of the moving member so as to acquire the piece of position image data for the second position when the moving member is at the second position after acquiring the piece of image data for the first position. The speed calculating unit is configured to calculate a moving speed of the moving member from the pieces of image data.

Moving-member detecting device and image forming apparatus

A projection optical system is disclosed. The projection optical system includes a first optical system configured to form a first image conjugated with an object and a second optical system configured to project a second image conjugated with the first image toward a projection surface. At least one of the first optical system and second optical system includes at least one optical element(s) movable relative to the object is provided. An image distance of the projection optical system is changed and a size of the second image is changed, by moving at least one of the optical element(s) relative to the object.

Projection optical system and image projecting apparatus

An objective is to achieve a positional change measurement device which measures positional change of a dynamic measured surface by using speckle patterns while easily reducing influence of fluctuations in a measurement environment temperature. Provided is a positional change measurement device including: a light source; an illuminating optical system configured to guide light from the light source to a measured surface; an imaging optical system; an image pickup device configured to acquire a speckle pattern by receiving reflection light from the measured surface via the imaging optical system; and detected-length compensation means for compensating for fluctuations in a detected length caused by temperature fluctuations. Positional change of the measured surface is measured based on a result of cross-correlation computation performed on multiple speckle patterns acquired at predetermined time intervals.

Positional change measurement device, positional change measurement method, and image forming apparatus

A projection optical system includes first and second optical systems. The first optical system includes a transmissive-refractive element and the second optical system includes a reflective-refractive element. An image formed by a spatial light modulator is projected by the projection optical system on a projection surface. A light beam that travels along an optical path that leads from the second optical system to the projection surface in an optical path between a center of the image formed by the spatial light modulator and the projection surface is projected at an angle with respect to a normal to the projection surface. An optical axis of the first optical system is folded to a folded position by an optical path deflecting unit in an area of the first optical system where the light beam entering the optical path deflecting unit is a converging light beam or a substantially parallel light beam.

Projection optical system

A document illuminating system includes a plurality of light emitting elements arranged in an array, a reflective element which guides light emitted from the light emitting elements to a document read area of a certain width and length. The reflective element includes first to third reflective portions. The second reflective portion includes one or more planar reflective faces and is disposed so that the reflective faces reflect light from the light emitting elements to one or both of the first and third reflective portions without other reflective elements. The first and third reflective portions each include one or more planar reflective faces and are disposed so that their reflective faces oppositely illuminate the document read area together by reflecting light from one or both of the light emitting elements and the second reflective portion to the document read area without other reflective elements.

Document illuminating system and image reader including the same

A projection optical apparatus capable of providing high image quality and having a reduced size is disclosed. The projection optical apparatus includes a light valve and a projection optical system including a first optical system having a transmissive-refractive element and a second optical system having a reflective-refractive element. An image formed on the light valve is projected by the projection optical system on a projection surface. The optical axis in the first optical system is folded both vertically and horizontally. The first group of the first optical system is contained in a space (dead space) whose lower limit is defined by a lower edge of the second optical system, thereby reducing the depth of the apparatus.

Projection optical apparatus

An image projection device performing pixel shift in synchronization with sequential updating of image data is disclosed that is able to start and stop pixel shift operations within a period of updating the image frames while maintaining brightness of the image. The image projection device has an intermediate image formation optical system including a light valve able to update an image frame in a line-sequential manner, a pixel shift unit to shift the light path of a light beam from the light valve so as to shift a position of an image formed on the light valve, and an intermediate image formation unit arranged on the light path between the light valve and the pixel shift unit for forming an intermediate image of the image on the light valve at a position of the pixel shift unit.

Intermediate image formation optical system, image formation device, and methods thereof

Disclosed is a projection optical system including a projection surface configured such that an image conjugate to an object is projected, plural optical elements having a refractive power, and a deflecting element having no refractive power configured to deflect an optical path of a light beam and to pass the light beam having a deflected optical path between the plural optical elements, wherein a normal line of the projection surface at a center of the projection surface does not pass through the plural optical elements or between the plural optical elements.

Projection optical system and image displaying apparatus

A projection optical system including a first optical system configured to form a second image conjugate to a first image and a second optical system configured to include a reflective optical element which reflects light from the second image and to project a third image conjugate to the second image onto a projection surface is provided, wherein the first optical system includes a stop and at least one optical element with a positive refractive power and at least one optical element with a negative refractive power which are provided between the stop and the second image, and an optical element with a strongest positive refractive power in the at least one optical element with a positive refractive power is provided between the stop and an optical element with a strongest negative refractive power in the at least one optical element with a negative refractive power.

A projection optical system including a first optical system configured to form a second image conjugate to a first image and a second optical system configured to include a reflective optical element which reflects light from the second image and to project a third image conjugate to the second image onto a projection surface is provided, wherein the first optical system has a Petzval sum with a sign opposite to a sign of a Petzval sum of the second optical system.

A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.

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Tokyo, Japan

Atsushi Takaura