Shoji Shirai

Saturation of Zn2SiO4 : Mn luminescence under intense vuv excitation

Output luminescence of Zn2SiO4 : Mn phosphor saturates under intense vacuum ultraviolet radiation having a relatively high excitation duty ratio. The saturation is attributed to the depletion of activators at the ground level. This depletion originates from the long decay time constant of the phosphor. The saturation mechanism is explained analytically using a simple model, and the conditions for efficient phosphor excitation are derived.

An intense and efficient source of vacuum ultraviolet radiation: Low‐ pressure Xe Townsend discharge

An intense vacuum ultraviolet spike 0.2 μs in width is observed at the initial stage of low‐pressure Xe discharge, i.e., Xe Townsend discharge, in submillimeter tubes. The intensity of the 147 nm resonance line reaches 1.3 W/cm2, about 200 times stronger than that obtained from the steady‐state Xe positive column. Efficiency of the vacuum ultraviolet radiation exceeds 24%, or 32 lm/ W when green phosphor is excited, four times higher than that of the positive column, or more than an order of magnitude higher than that of the negative glow. This high intensity and efficiency originate from the optimized electron energy which can be adjusted externally by changing the electric field and pressure, contrary to that in the positive column or negative glow. Another important feature of the Townsend discharge is its wide dynamic range of operation, which is advantageous when driving a panel having a large number of cells with scattered discharge characteristics. Consequently, a gas discharge display panel utiliz...

P‐16: Simulation and Analysis of Overall Raster Moire Patterns on Color CRTs

Generation mechanisms of various moire patterns are clarified, and a simulation technique of overall raster moire patterns appearing on the color CRT screen is developed. The moire patterns are found to be sensitive to the slope and curvature of the scan lines. The technique allows to determine various CRT design parameters.

A 100 lm/W efficacy low‐pressure Xe discharge tube

The luminous efficacy of a Zn2SiO4:Mn‐coated, low‐pressure Xe‐positive‐column fluorescent tube is found to be as high as 100 l/W which corresponds to an electric to 147‐nm radiation energy conversion factor of 66%. This high efficacy can be attained under conditions (pressure)×(column diameter)≃1 Torr cm and (current density)?3 mA/cm2.

CRT electron-optical system

CRT is the most successful electron optical system, commercially. Over a hundred million systems are produced each year, and distributed to the whole world as television sets or personal computers. Therefore, the system has to be extremely cost and power effective, and ergonomics is the important issue at its design. Also, CRT has to be bright enough to be watched in the luminous living or office room. Therefore, electron beam current and anode voltage (CRT screen voltage) are as high as 0.5 to 7 mA and 20 to 33 kV, respectively. These unique restrictions cause unique electron lens design such as in-line rotationally asymmetrical lens or dynamic quadrupole lens and deflection yoke design such as self converging deflection yoke which produces barrel shaped vertical and pin-cushion shaped horizontal magnetic fields. In this paper the recent technical advancement and future trends of the CRT electron optical system will be discussed. The discussion will be restricted only to the picture tube, and other devices such as camera tube, oscilloscope tube will be excluded.

28.4: Electron-Gun Simulator including Work Function and Cathode Potential Barrier

Axi-asymmetric CRT electron gun simulator which includes the effects of cathode temperature, work function of cathode material and potential barrier near the cathode surface created by an electron beam has been developed. With the simulator, difference of cathode emitter materials, effects of cathode temperature on emission characteristics and transitional phenomena during cathode heating can be evaluated.

Dysplay-Special Contribution from IWD'02-A 16-cm Dual Neck Diameter, Integrated Component, Projection CRT

A 16cm, ∅29.1mm compatible projection CRT, integrated component system has been developed utilizing an LD-Hi-UPF electron gun with an effective focusing lens of 21mm. This was achieved with a dual diameter neck (∅29.1-36.5mm) integrated component design. The current ∅29.1mm projection CRT deflection power was maintained while reducing the 5% center beam spot profile size by 20% (2mA optimum focus). The integrated components were optimized to provide the system with improved corner focus. This CRT delivers superior image quality and is compatible with current ∅29.1mm neck CRTs in rear projection systems.

Generation mechanism and evaluation of overall raster moiré patterns on color CRTs

— An evaluation technique of overall raster moire patterns on color CRTs is developed. The technique can simulate any of the moire modes. Generation mechanisms of various moire patterns are clarified using the technique. It is found that the moire patterns, no matter how complicated, consist of four basic types: barrel, pincushion, elliptical, and hyperbolic types. The patterns are found to be sensitive to the scan line distribution. When the scan lines are curved, the pattern appearing on the upper screen is different from that on the lower screen. When the scan lines are tilted, the patterns have horizontal shifts. By observing the moire patterns, the scan line distribution can be estimated precisely.

36.3: High Sensitivity and Low Cross-Talk Deflection Yoke for Projection Displays

The deflection yoke (DY) with high sensitivity and low cross-talk convergence yoke (CY) for Projection display has been developed. Compared to a conventional convergence yoke, the improved ones have one more convergence yoke toroidal coils on the deflection yoke core. As the result, the convergence yoke sensitivity have been improved about 16%, and the cross-talk voltage in the convergence yoke affected by the deflection yoke has been reduced about 50% at the same time.

Asia Display '95. Development of a 56cm Wide-Screen Color Data Display Tube.

We have developed a 56 cm wide color data display tube. The tube has a resolution of 2 M pixels and a display area 11% larger than the convetional 4 : 3 format 51 cm color data display tube.