Mitsubishi Denki Kabushiki Kaisha

International Business Machines Corporation

Tetsuo Shiba

Yasuhiro Kitabatake

Norio Hayafuji

Hirotaka Kizuki

Hitoshi Tada

Nobuaki Kaneno

Daisuke Suzuki

Tatsuya Kimura

Masayoshi Takemi

Shogo Takahashi

Kenji Ikeda

Kazuhisa Takahashi

Kimitaka Shibata

Hideyo Higuchi

A system for generating an image of a seal impression. The system includes: means for acquiring N still images of a face of a seal corresponding respectively to N beams of light striking the face in succession, wherein N is at least 2; and means for combining the N still images to generate a composite image of pixels, wherein a common area of pixels in the composite image appears on the face of the seal in all still images of the N still images, and wherein the common area includes a character area pertaining to where an engraved character is located on the face of the seal.

Generation of an image of a seal impression

A method and apparatus for generating an image of a seal impression. N still images of a face of a seal are combined. N is at least 2. The N still images of the face correspond respectively to N beams of light that had previously irradiated the face in succession from N respective different directions respectively corresponding to N different angles of incidence of the light on the face. The combining of the N images include generating in the composite image a common area of pixels that commonly appears on the face of the seal in all still images of the N still images. The common area includes a character area pertaining to where an engraved character is located on the face of the seal.

Generating an image of a seal impression

A method and apparatus for generating an image of a seal impression. Irradiation of a face of a seal with N beams of light striking the face in succession from N respective different directions respectively corresponding to N different angles of incidence of the light on the face is caused, the face having a character thereon, N&#x2267;2. N still images of the face corresponding respectively to the N beams are acquired, each still image structured as pixels including a RGB color combination. The N still images are combined to generate a composite image of pixels that includes a common area of pixels that commonly appears on the face of the seal in all still images, the common area having a luminance value exceeding a specified luminance threshold, the common area including a character area pertaining to where the engraved character is located on the face of the seal.

A semiconductor device includes a p type InP substrate with a (001) surface; a mesa structure formed by dry etching, extending along a &lt;110&gt; direction, including semiconductor layers, having (110) side surfaces, and a height H.sub.m ; and mesa burying layers including a p type InP burying layer on the (110) side surfaces and the (001) surface, the p type InP burying layer having a thickness D.sub.p, and an n type InP burying layer on the p type InP burying layer. An angle between a (111)B surface and (001) surface is .theta..sub.111, the growth rates on the (110) side surfaces and on the (001) surface are respectively R.sub.g (110) and R.sub.g (001), an angle .theta. is tan .theta.=R.sub.g (110)/R.sub.g (001) and the critical thickness D.sub.n of the n type InP burying layer on the (001) surface when the n type InP burying layer is not grown on the (111)B surface is ##EQU1## The n type InP burying layer has a thickness D.ltoreq.D.sub.n. The leakage current path width is narrowed and contact of the n type InP burying layer and an uppermost layer of the semiconductor layers is avoided. Consequently, a semiconductor device having reduced leakage current and superior device characteristics is obtained.

Semiconductor laser

A semiconductor laser device including a semiconductor substrate; a plurality of semiconductor layers including an AlGaAs layer epitaxially grown on said semiconductor substrate; a ridge having a reverse mesa shape and opposed sides formed of said plurality of semiconductor layers; an Al.sub.x Ga.sub.1-x As low temperature buffer layer (0.ltoreq..times..ltoreq.1) disposed on said AlGaAs layer at opposite sides of said ridge; a first semiconductor layer epitaxially disposed on said low temperature buffer layer at opposite sides of said ridge; and a second semiconductor layer epitaxially disposed on said ridge and said first semiconductor layer.

Semiconductor laser including ridge confining buffer layer

Element production process in a method for producing an embedded type optoelectronic integrated circuit comprising an optical element part and a signal processing part, includes steps of producing a mask film on a surface of the substrate and removing a predetermined region of the film to produce a selective growth mask, producing a concave portion at a predetermined region on the surface of the substrate by etching using the selective growth mask, producing a crystal layer which is to be an optical element part in the concave part by crystal growth using the selective growth mask, flattening the surface of the crystal layer by grinding swelling crystal at the edges of the concave portion, and removing the selective growth mask and conducting mirror polishing by mechanochemical etching. Therefore, even when an optical device is embedded in the substrate using crystal growth method, a step due to swelling crystal does not arise on the substrate and .parts of wafer damaged by grinding is removed. Thus, the following process is eased.

Method for producing an embedded optoelectronic integrated circuit

In a method for producing a semiconductor device, a first semiconductor layer is epitaxially grown on a semiconductor substrate, an insulating film pattern is formed on the first semiconductor layer, and portions of the first semiconductor layer are removed by wet etching using the insulating film pattern as a mask to leave a ridge having a reverse mesa shape and a width. Ends of the insulating film pattern are removed by etching to approximately the width of the ridge, a second semiconductor layer is epitaxially grown on opposite sides of the ridge, and a third semiconductor layer is epitaxially grown on the ridge and the second semiconductor layer. The second semiconductor layer is evenly grown without concave portions at opposite sides of the ridge. In addition, the third semiconductor layer is evenly grown on the ridge and the second semiconductor layer, and an electrode reliably connects the surface of the third semiconductor layer. A semiconductor device with good performance and high reliability is reproducibly manufactured.

Method for producing semiconductor device

A semiconductor light detector for detecting multiple wavelengths of light includes a semiconductor substrate, a plurality of first conductivity type semiconductor layers successively disposed on the semiconductor substrate with increasing energy band gap from the substrate towards a light incident surface of the detector, a first second conductivity type semiconductor region extending from the light incident surface and reaching the first conductivity type layer closest to the surface, and one or more additional second semiconductor regions successively surrounding the first second semiconductor region, reaching the surface and respective first conductivity type semiconductor layers.

Semiconductor light receiving element

An MSM type semiconductor light responsive element includes a semiconductor substrate, a first semiconductor layer, a pair of electrodes disposed on the first semiconductor layer forming Schottky barriers, and a second semiconductor layer comprising a semiconductor having a larger energy band gap than that of the first semiconductor layer disposed between and contacting the electrodes.

MSM type semiconductor light responsive element

A semiconductor light receiving device, including; a photo diode having a polyimide film as a surface protection film, and a hermetically sealed package including the photo diode in an ambient gas including oxygen.

Growing community of inventors

Itami, Japan

Tetsuo Shiba