Ricoh Company, Ltd.

Ricoh Research Institute of General Electronics Co., Ltd.

Takaaki Miyashita

Kazuhiro Fujita

Takashi Takahashi

Wasaburo Ohta

Keishi Kubo

Hirokazu Iwata

Ikuo Maeda

Haruo Iimura

Toshiyuki Inokuchi

Kenya Yokoi

Akihiko Kanemoto

Takamichi Enomoto

Fuyuhiko Matsumoto

Hiroyuki Iechi

Akiyoshi Yasumori

Toru Miyabori

Chizuru Yoshida, Legal Representative

Tomoaki Yoshida, Deceased

Shunichi Satoh

A light emitting diode chip includes a substrate carrying thereon a number of light emitting diodes aligned in a row to form an array for producing a number of optical beams parallel to each other in a first direction, and monitoring element provided monolithically on the substrate for detecting the power of the optical beams produced by the light emitting diodes, wherein the monitoring element includes: a reference light emitting diode having a structure identical to the light emitting diodes in the array for producing an optical beam in a second direction perpendicular to the first direction; and a photodiode having a structure identical to the light emitting diodes in the array and separated from the reference light emitting diode by an isolation groove for detecting the optical beam produced by the reference light emitting diode.

Optical line printhead and an LED chip used therefor

A picture reading apparatus with flaring light elimination capability, which includes a light source for emitting light, a contact glass with which a document to be scanned comes in contact, a lens array in which a plurality of lenses for converging the light from the light source are arranged at equal intervals therebetween, a roof mirror array in which a plurality of roof-like reflection surfaces are arranged corresponding to the plurality of lenses, a restricting plate for eliminating undesired light between adjacent lenses of the lens array, a housing in which the roof mirror array and the lens array are accommodated, a sensor, and a separation mirror. The apparatus further includes a light shield layer provided on the contact glass, at a portion other than a reading portion through which the light from the light source passes to scan the document, for eliminating undesired light, other than the converged light effective in supplying a picture signal.

Picture reading apparatus with flaring light elimination capability

An image forming device is improved in that crosstalk between adjacent lenses is decreased thereby to improve an imaging power. In the image forming device a lens array has a plurality of lenses continuously formed. A roof prism array is also provided therein with a plurality of roof prisms respectively having a rectangular reflection plane and arranged at the same pitch as that of the lenses in the lens array. The lens array and the roof prism array are integrally formed of a plastic. A space portion, which is a portion unfilled with a resin, is formed between respective two adjacent roof prism lens pairs to prevent the crosstalk therebetween. Alternatively, a light shielding member may be integrally formed in front of the lens array to prevent the crosstalk.

Image forming device and method for producing it

A projection device for irradiating a light to a display device and optically magnifying and projecting a reflection light therefrom includes a liquid crystal cell, a first polarization device and a reflection device disposed respectively on the opposite side from the irradiated side of the liquid crystal cell and a second polarization device and optical magnifying means disposed respectively on an optical path of the reflection light reflected by said reflection device and outgoing from said liquid crystal cell.

Projection device for irradiating a light to a display device and

A casing in the form of a slender hollow structure has a slit-shaped entrance aperture defined in an upper cover thereof and a slit-shaped exit aperture defined in a lower cover thereof. The casing houses a covex roof-shaped mirror having a convex reflecting surface, a lens array, a concave roof-shaped mirror array having an array of convex reflecting surfaces, and a spacer interposed between the concave roof-shaped mirror array and the lens array to keep them spaced apart. The upper and lower covers of the casing are integrally formed with or securely coupled to the spacer. A light shield plate lies between the corner of the convex roof-shaped mirror and the lens array, and a reflecting plate is mounted on the upper cover of the casing for reflecting light from a light source to an object to be imaged. A sensor for detecting the amount of light emitted from the light source is also mounted on the casing.

Optical imaging device

A confidential document reproduction prevention method of preventing confidential documents from being reproduced. This method is carried out by applying a particular material as a confidential mark at least to one portion of the surface of a confidential document, which material, when exposed to illumination light, is capable of emitting light with a wavelength different from the wavelength of the illumination light; detecting the light emitted from the material by a detector in a reproduction machine when the document is exposed to the illumination light; and making the reproduction machine inoperative, upon detection of the light emitted from the material.

Confidential document reproduction prevention method

Growing community of inventors

Yokohama, Japan

Takaaki Miyashita