Abstract: A three-dimensional shape measuring apparatus includes a projection device having a projecting plane witha grating pattern formed therein and a light source for illuminating, through the projection plane, an object of interest located at an arbitrary position in the same three-dimensional coordinate system as that of the projection device, an observation device located in the same three-dimensional coordinate sysem as that of the object and having an observation plane and a specific point located between the observation plane and the object. In the apparatus, the grating pattern in the projection plane is projected on a surface of the object to form a projected grating pattern thereon when the light source is turned on, the grating pattern projected on the object is observed in the observation plane.

Abstract: A shape measuring apparatus includes a first light source for illuminating a solid object in a proper place through a first slide, a second light source for illuminating the object through a second slide and an observation plane permitting the surface of the object to be observed through a focal point. Each of the first and second slides, contains slit lines. When the first and second light sources are lighted, the slit lines of the first and second slide are projected, in an intersecting pattern, on the surface of the object. A projection grating is formed on the surface of the object and is observed, as a projection grating, in the observation plane.

Abstract: A phosphor having formed on its surface generally spherical or semi-spherical surface treating substance composed of silicon dioxide, an aluminum compound and a zinc compound, at least 70% by weight of the surface treating substance being in the form of particles having an average particle size within a range of from 60 to 300 m.mu.m.

Abstract: Nematic liquid crystal compositions having positive dielectric anisotropy are obtained by mixing at least one of p-n-alkylphenyl-p'-cyanobenzoates represented by the formula, ##STR1## wherein R.sub.2 is n-alkyl group of 3 to 8 carbon atoms with at least one of p-cyanophenyl-p'-n-alkylbenzoates represented by the formula, ##STR2## wherein R.sub.1 is n-alkyl group of 4 to 8 carbon atoms. Said compositions exhibit nematic liquid crystal phase over a broad temperature range and therefore, are useful for the torsion effect-type display device.