Abstract: A color cathode-ray tube 10 has an evacuated envelope 11 with an electron gun 26 therein for generating at least one electron beam 28. The envelope further includes a faceplate panel 12 having a luminescent screen 22 with phosphor lines on an interior surface thereof. A uniaxial tension focus mask 25, having a plurality of spaced-apart first metal strands 40, is located adjacent to an effective picture area of the screen 22. The spacing between the first metal strands 40 defines a plurality of slots 42 substantially parallel to the phosphor lines of the screen. Each of the first metal strands 40, across the effective picture area of the screen, has a substantially continuous first insulator layer 64 on a screen-facing side thereof. A second insulator layer 66 overlies the first insulator layer 64. A plurality of second metal strands 60 are oriented substantially perpendicular to the first metal strands 40 and are bonded thereto by the second insulator layer 66.

Abstract: The present invention provides a method of making a tensioned focus mask. Such a mask includes a set of parallel strands and a set of parallel wires that are perpendicular to the strands and separated from the strands by insulator means. The method includes attaching the strands to a mask frame and then coating the strands with a first insulator. The first insulator is then cured, and a second insulator is applied to the first insulator. Next, wires are wound over and in contact with the second insulator, by rotating the mask frame and by drawing a continuous wire from a source through a tensioner, while guiding the continuous wire into desired positions overlying the strands. Finally, the second insulator is heated until the wires attach to the second insulator.

Abstract: The present invention provides an improvement in a color picture tube having a tensioned mask and support frame assembly. Each of the mask and the support frame is rectangular and has two long sides that parallel a central major axis thereof and two short sides that parallel a central minor axis thereof. The mask has a substantially cylindrical contour, being curved along the major axis and straight along the minor axis. The improvement comprises the frame including two first members that parallel the major axis and two second members, attached to the ends of the first members, that parallel the minor axis. Each of the first members includes a rigid section and a compliant section cantilevered from the rigid section. The mask is attached to the distal ends of the cantilevered compliant sections.

Abstract: The present invention relates to a method for pre-stressing the CRT tension mask 24 to induce creep. The method includes the steps of applying a suitable force to the mask material to induce stress therein, heating the mask material to an ultimate temperature, for a sufficient time, while under stress, to induce creep, and cooling the material.

Abstract: The invention is an improved arrangement for illuminating a liquid crystal cell which provides a significant increase in the range of viewing angles in a plane orthogonal to the principal viewing plane which is defined as the plane containing the director at the midpoint of the liquid crystal and the normal to the light entry surface. The improvement comprises means for illuminating the cell having a substantially collimated beam in the orthogonal plane. Preferably, the thickness of the liquid crystal in the cell corresponds to the first Gooch-Tarry minimum. The invention is also a method for providing a wide angle for a liquid crystal display comprising the step of illuminating a liquid crystal cell with a beam of light which is substantially collimated in the principal viewing plane and which is substantially uncollimated in an orthogonal plane.

Abstract: A light box comprises a source of light, a reflector and a Fresnel lens. The lens provides nearly constant illumination of an object such as a liquid crystal cell by collimating light parallel to a normal to the cell. Thus the cell will exhibit a nearly uniform electro-optical response. The reflector preferably is parabolic, while the light source preferably is a line source such as a fluorescent tube.

Abstract: A display comprises means for changing the polarization of light, such as a liquid crystal cell, and has a means for analyzing light on one side thereof. A means for diffusing light is disposed between the cell and the analyzing means. This arrangement results in a higher contrast ratio for the display than for the prior art arrangement having the analyzing means disposed between the cell and the diffusing means.

Abstract: Accumulated foreign material on the signal pickup stylus of a video disc player tends to degrade the quality of the recovered information signal. The recovered information signal is detected and the nominal amplitude of the recovered signal is compared against a reference amplitude. The occurrence of a decrease in recovered signal amplitude below the level of the reference causes a comparator to generate a control or trigger pulse. The control pulse activates a pulse generator to produce a predetermined pulse sequence which is applied to a stylus deflection transducer to move the stylus fore and aft radially across the disc and thereby dislodge the foreign material from the pickup stylus.

Abstract: A video disc playback system includes a circuit for detecting degradation in signals recovered from a disc and generates a control pulse responsive to the detected degradation. The degradations are of a predetermined duration and represent a predetermined percentage decrease in amplitude. A peak detecting and following circuit is connected for receiving signals recovered from the disc record. The decay rate of the peak detecting circuit is arranged to be substantially equal to a certain minimum duration of amplitude degradations that should occur before it is desired to generate the control pulse. The output signal from the detector circuit is proportioned by a divider circuit and then integrated to produce a signal which is proportional to the average of the detected signal over a relatively long period of time. The proportioned signal is applied to the reference signal terminal of a comparator circuit and the detected signal is applied to the signal input terminal of the comparator.