Abstract: An isothermal block has a multi-layer thermal conductor interleaves with different layers of a printed circuit board to provide improved thermal coupling of input terminals and a local temperature sensor mounted on the isothermal block. Each of the layers of the thermal conductor is substantially thinner than substrate layers of the printed circuit board. The layers of the thermal conductor are spaced apart from the terminals so as to be electrically isolated from the terminals. Embedded layers of the thermal conductor are spaced closer to the terminals than are external layers of the thermal conductor.

Abstract: A touch sensitive data input device is provided for use with the screen of a cathode ray tube. The device has an annular bezel that loosely supports a firm clear backing plate. A rear transparent sheet element that has a coefficient of thermal expansion different from that of the backing plate is loosely retained against the backing plate to avoid deformation induced by differential thermal expansions. A closely spaced apart front transparent element is placed adjacent the rear transparent sheet, their respective adjacent surfaces having mutually orthogonal electrically conductive strips that make local electrical contact when a force is applied to the front element. An annular frame over the front element is secured to the bezel. In one aspect of the invention, a gasket with both sides coated with a resilient bonding material seals the frame to the bezel to protect the zone between the transparent front and rear elements from contamination by environmental pollutants.