Ricoh Company, Ltd.

Sanyo Electric Co., Ltd.

Ricoh Optical Industries Co., Ltd.

Yoshitsugu Kohno

Osamu Nagase

Kazuhiro Fujita

Takashi Ikeda

Atsushi Takaura

Ryuhei Amano

Issei Abe

Akihiro Yamakage

Kiichiro Nishina

Taira Kouchiwa

Yuichiro Kanoshima

Shinichi Okuno

Kohji Ichimiya

Kazuhisa Takahashi

Naomi Harada

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

Disclosed are a projection display apparatus and a projection optics provided in the projection display apparatus. The projection optics has a refractive optics and a reflective optics. In the refractive optics, a lens (non-circular lens) provided on a reflective optics side has a non-circular shape forming part of an imaginary circular region whose center is an optical axis center of the refractive optics. In other words, the non-circular lens has a shape of a cut-out portion of an imaginary circular lens having an optical axis center coinciding with the optical axis center of the refractive optics.

Refractive optics and projection display apparatus

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

A projection optical system includes a first refracting optical system having a plurality of lenses, a first reflecting optical system, and a second reflecting optical system. The first reflecting optical system is disposed on a side of a projection port with respect to an optical axis of the first refracting optical system, and has a positive optical power to reflect light incident through the first refracting optical system in a direction opposite to the side of the projection port. The second reflecting optical system is operable to reflect the light reflected on the first reflecting optical system toward the projection port.

Projection optical system and projection display device

A reading lens for a scanner to read an original in a reduced magnification, the lens comprising six lenses, i.e., from a first lens to a sixth lens in order on an optical axis. The first lens is a positive lens having a first lens-surface and a second lens-surface. The second lens is a negative lens disposed in contact with the first lens and has the second lens-surface in common with the first lens and a third lens-surface. The third lens is a meniscus lens and has a fourth lens-surface and a fifth lens-surface. The fourth lens is a meniscus lens and has a sixth lens-surface and a seventh lens-surface. The fifth lens is a negative lens and has a eighth lens-surface and a ninth lens-surface. The sixth lens is a positive lens disposed in contact with the fifth lens and has the ninth lens-surface in common with the fifth lens and a tenth lens-surface. At least one of the ten lens-surfaces is formed as an aspherical surface.

Reading lens for scanner

Growing community of inventors

Iwate, Japan

Yoshitsugu Kohno