Abstract: A method for modifying a phase change ink jet head by applying a non-wetting material to the discharge surface is provided such that an ink contact angle between about 80.degree. and about 90.degree. is maintained on the discharge surface after continued exposure to molten phase change inks. Furthermore, the method provided ensures that the layer of non-wetting coating material does not chip or wear off during the normal operation of the ink jet printer. In this way, the ink jet printer is capable of accurate placement of phase change ink drops without increased surface wetting and off-axis shooting that traditionally occurs after continued use.

Abstract: A liquid crystal cell (40) for an electron beam-addressed liquid crystal light valve has a rigid glass substrate (16) and target substrate (44) formed of thin flexible material. The cell (40) is constructed so that the spacing between the flexible substrate (44) and the rigid substrate (16) is precisely maintained. A fixture (72) is employed for attaching the target substrate (44) to the rim (102) of the light valve body (14) prior to assembly of the cell (40).

Abstract: The cathode-ray-tube beam deflection of an oscilloscope is automatically calibrated by photoelectrically detecting the intersection of the tube's electron beam with visible graticule lines on the tube's faceplate. An input signal is compared, at the time of intersection, with stored values representative of the graticule lines, and the deflection amplifier gain of the oscilloscope is adjusted until the graticule lines properly represent the measurement of the input signal.

Abstract: An improved method of forming a multicolor cathode-ray tube display screen to minimize phosphor contamination. A light-absorbing matrix is first formed on the inner surface of a CRT faceplate, preferably by photoetching of a substantially black metallic layer. Then, multiple color dot patterns are deposited in the matrix openings by (a) depositing a layer of positive photoresist on the matrix and any previously-deposited dot pattern; (b) exposing the resist through a shadow mask to light from a point source positioned to simulate an electron gun; (c) developing the resist to form an integral mask containing a pattern of holes aligned with the matrix openings for one color phosphor; (d) coating the developed resist layer with a photohardenable phosphor slurry; (e) exposing the slurry coating through the faceplate to light from a diffuse source; (f) developing the slurry to remove the unexposed portions, leaving a pattern of dots of one color; and (g) stripping away the photoresist masking layer.