Abstract: A protected/security document is provided that foils counterfeiting even if a laser photocopy machine (such as a Canon 500 color copier) is utilized. The document has at least three discrete half-tone printed bands disposed on its surface, provided by dots or lines. Each printed band has a different screen density and within each bands the dots or lines comprise a warning word or symbol (e.g. “Void”), or a background. The dots or lines of either the “Void” or background drop out when photocopied, while the dots or lines of the other do not. The dots or lines that do not drop out may be dimensioned so that there are about 24-34 per centimeter, while for those that do drop out there are about 52-64 per centimeter. The bands are typically arranged either linearly or in concentric circles, and interband areas having density gradually transitioning between the densities of adjacent bands are provided.

Abstract: A protected/security document is provided that foils counterfeiting even if a laser photocopy machine (such as a Canon 500 color copier) is utilized. The document has at least three discrete half-tone printed bands disposed on its surface, provided by dots or lines. Each printed band has a different screen density and within each bands the dots or lines comprise a warning word or symbol (e.g. "Void"), or a background. The dots or lines of either the "Void" or background drop out when photocopied, while the dots or lines of the other do not. The dots or lines that do not drop out may be dimensioned so that there are about 24-34 per centimeter, while for those that do drop out there are about 52-64 per centimeter. The bands are typically arranged either linearly or in concentric circles, and interband areas having density gradually transitioning between the densities of adjacent bands are provided.

Abstract: An orifice installation for sealing a plate within a fitting is disclosed. The plate has a seal surrounding its outer circumference. The seal has a large base area of elastomeric material and an outer and inner periphery face. A central circumferential extension larger than the distance in the fitting for permitting entry of a plate carrying device is formed between the shoulders. Circumferential indentations formed in the base separate the shoulders from the extension.

Abstract: An orifice installation for centering the orifice aperture within a plate carrying device is disclosed. The orifice installation uses an orifice plate in cooperation with a seal that surrounds the outer edge of the orifice plate to seal the plate to a fitting. Reliefs are formed in the nonsealing portion of the surface of the seal through which the orifice plate outer circumference protrudes. The carrying device is provided to receive the plate and the seal. A mechanism is provided to have contact between the carrying device and the protrusions in order to use the manufacturing tolerances of the plate and the carrying device to center the plate in the carrying device.

Abstract: An orifice installation for centering the orifice aperture within a plate carrying device is disclosed. The orifice installation uses an orifice plate in cooperation with a seal that surrounds the outer edge of the orifice plate to seal the plate to a fitting. Reliefs are formed in the nonsealing portion of the surface of the seal through which the orifice plate outer circumference protrudes. The carrying device is provided to receive the plate and the seal. A mechanism including an intermediate interface is provided to have contact between the carrying device and the protrusions in order to use the manufacturing tolerances of the plate and the carrying device to center the plate in the carrying device.