Abstract: A ceramic link element suitable for use as a component in the drive train of an internal combustion engine is provided. The link includes a central shaft portion with opposed spherical terminal ends that contact correspondingly configured elements in the drive train. The ceramic link element is formed, preferably by injection molding, to be substantially free from flaws and to have maximum pore diameters, preferably a maximum pore diameter of 150 um or less on the shaft and 40 um or less on the spherical terminal ends, to produce a link with optimum mechanical strength. When these pore dimensions are met and the degree of sphericity of the spherical terminal ends is 20 um or less, the ceramic link exhibits increased mechanical strength, durability and reliability. A method of forming a ceramic link having the aforementioned characteristics is also provided.

Abstract: An lighting apparatus including a housing having an opening, a light source received in the housing and a light transmitting-cover fixed at the opening of the housing and through which light rays are projected from the light source. The light transmitting-cover includes a plate made of light transmitting-material and having a first surface and a second surface. Segment lens elements of the same size are arranged on the first and second surface of the plate and formed integrally with the plate. The segment lens elements on the first surface are positioned in face-to-face relation with the segment lens elements arranged on the second surface, thus forming a segment lens. The segment lens elements have a common optical axis and convex surfaces, respectively. The focal lengths defined by these convex surfaces are equal.

Abstract: In a rear projection screen, a pair of light-refracting plates oppose each other. A plurality of first convex lens elements are arranged parallel to each other on one surface of the light-reacting plate, and a plurality of second convex lens elements are arranged parallel to each other on the other surface of the light-refracting plates. Similarly, a plurality of first convex lens elements are arranged parallel to each other on one surface of the light-refracting plate, and a plurality of second convex lens elements are arranged parallel to each other on the other surface of the light-refracting plate. Each pair of opposed first and second convex lens elements is located along a common optical axis thereof. A convex surface of each first convex lens element is located at a focal plane of the corresponding second convex lens element. A convex surface of each second convex lens element is located on a focal plane of the corresponding first convex lens element.

Abstract: A rear projection apparatus for producing an optical image on a surface of a rear transmitting screen in which a convex lens array is formed on both surfaces of the screen, each convex lens formed on one surface of the screen having a corresponding convex lens formed on the other surface of the screen with a common optical axis, the focal point of each convex lens formed on one surface of the screen being on the surface of the each convex lens formed on the to other surface of the screen.

Abstract: An optical refractor comprises a plate made of transparent material and having a first surface and a second surface. Segment lens elements of the same size are arranged on the first and second surface of the plate and formed integrally with the plate. The segment lens elements on the first surface are positioned in face-to-face relation with the segment lens elements arranged on the second surface, thus forming pairs of segment lens element. The segment lens elements have a common optical axis and convex surfaces, respectively. The focal lengths defined by these convex surfaces are equal. The focal point of one of the segment lens elements lies on the convex surface of the other segment lens element, and that of the other segment lens element lies on the convex surface of the first segment lens element.