Abstract: A threshold determination/binarization circuit and a recording medium for an information reproduction system, wherein the diameter of a reference dot detected by a reference dot diameter detection section is compared with a predetermined dot diameter as a standard value, and the threshold is adjusted such that the difference between the reference dot diameter and the standard value equals a predetermined target value, thereby obtaining the same binarization effect with respect to image signals obtained with different transfer characteristics (different media, recording states, and optical systems). This circuit also includes a maximum/minimum value detection section that detects the maximum and minimum values of an image signal level corresponding to a dot code. A threshold is calculated by using an internal ratio representing the radio between the maximum and minimum values so as to stabilize a reading operation against illumination and recording irregularity, contamination of a dot code, and the like.

Abstract: An optical image reconstructing apparatus includes an optical image forming system. A focused surface controller moves the position of an object surface focused by the optical image forming system. An image pickup converts an image of an object formed by the optical image forming system into an electrical signal and outputs the electrical signal as an image signal. An adder adds a plurality of image signals output from the image pickup while the position of the object surface is moved by the focused surface controller. A frequency filtering device performs a frequency filtering operation on an image signal outputted from the adder to produce a filtered image signal. A rotation controller rotates the object or the optical image forming system at a predetermined angular interval around one point on an optical axis of the optical image forming system.

Abstract: A cavity insert device comprising an insert section capable of being inserted into tracts and cavities, a detection circuit for detecting conditions of components making up the device, such as an observation device formed at the distal end side of the insert section, and a fuzzy inference section for synthetically determining a plurality of information signals outputted from the detection circuit and producing control signals to control the components. The fuzzy inference section employs inference rules which are empirically considered to be desirable, and control is made by the control signals obtained with the fuzzy inference. The device is thus operated in a nearly optimum state.

Abstract: This three-dimensional measuring apparatus comprises an imaging apparatus imaging a plurality of images having parallaxes, a displaying apparatus displaying on a plurality of pictures the plurality of images obtained by the imaging apparatus, a first object point designating apparatus designating a first object point corresponding to the measuring object point in the space on the first image of the plurality of images displayed by the displaying apparatus, a second object point designating apparatus designating a second object point corresponding to the measuring object point in the space on the second image of the plurality of images displayed by the displaying apparatus, an object point designating auxiliary apparatus making an auxiliary process relating to the second object point designation by the second object point designating apparatus after the first object point designation by the first object point designating apparatus and an operating apparatus making a measuring operation relating to the three-di

Abstract: A ceramic fiber felt is obtained by mixing alumina crystalline ceramic fibers having at least about 60 weight percent of Al.sub.2 O.sub.3, the rest being SiO.sub.2 and impurities, and having a filament length ranging from 10 to 30 mm with aluminosilicate non-crystalline ceramic fiber having from about 40 to 70 weight percent of Al.sub.2 O.sub.3, the rest being primarily SiO.sub.2, impurities, and, optionally, including a small amount of metal oxides, and having a filament length ranging from 5 to 30 mm, the weight proportions of the alumina crystalline ceramic fibers to the aluminosilicate non-crystalline ceramic fiber being from about 4:6 to 7.5:2.5, and preferably from about 4:6 to 5:5, and binding the mixture of components with an organic binder.The ceramic fiber felt having a linear percentage shrinkage at 1400.degree. C. of only about 2% is very inexpensive compared to alumina ceramic fiber and is highly suited for use as or in furnace linings.