Abstract: This incudes means for forming tomographic images of multiple cross sections by subjecting a plurality of projection data items covering a three-dimensional area of an object to a re-construction process, means for converting the tomographic images of multiple cross sections into binary images of multiple cross sections by a threshold process, and means for forming a three-dimensional model by curing liquid resin based on an image area of the binary images of multiple cross sections. With the above construction, it is possible to form a three-dimensional model of a portion extracted by the threshold process from the plurality of projection data items covering the three-dimensional area of the object.

Abstract: An optical information signal record medium which comprises a substance of a desired form having information signals encoded on at least one side thereof, a reflection thin layer of a Cu alloy, and a protective layer formed on the substrate in this order. The reflection thin layer is made of an alloy such as a Cu-Ni alloy, a Cu-Al alloy or a Cu-Ni-Al alloy each having a defined composition.

Abstract: A mirror assembly capable of providing an image of high or low brightness is pivotally supported by a housing or other stationary support, for movement between two operating positions to provide the high and low brightness images. For automatic actuation of the mirror assembly, a light sensitive element is provided which on sensing a change in the intensity of incident light, energizes an electromagnet or electromagnets affixed to either of the mirror assembly and the stationary support. The energized electromagnet or electromagnets attract and/or repel a permanent magnet or magnets affixed to the other of the mirror assembly and the stationary support. Normally, the core of the electromagnet or of one of the electromagnets is held attracted by the permanent magnet or by one of the permanent magnets to retain the mirror assembly in a selected one of the operating positions.