JPH032853A - Printing fluorescent screen - Google Patents

Abstract

PURPOSE:To obtain a high-brightness fluorescent screen whose visual angle dependency is small even in a simple method such as printing by dispersedly arranging fluorescent island-like parts on an opaque substrate. CONSTITUTION:The screen is constituted of the opaque substrate 10 and the fluorescent island-like part 11 printed on the substrate 10. The fluorescent island- like part 11 is obtained by uniformly printing ink consisting of high-viscosity filler containing phosphor in scattered dots pattern on the substrate 10. Since the fluorescent island-like part 11 holds the phosphor which sufficiently protrudes hemispherically from the substrate 10 in virtue of high viscosity of its own, the fluorescence is uniformly emitted ahead when the surface of the part 11 is irradiated with exciting light and the visual filed dependency of the fluorescence is eliminated. As to the screen, an image is formed by radiating the stimulating light from a visual observation side, that is, from above a drawing as a spot corresponding to the fluorescent island-like part and the brightness of the display panel in reference to the identical exciting light quantity is improved by increasing the emitted light quantity of the visual observation side.

Description

TECHNICAL FIELD The present invention relates to a phosphor screen containing phosphors that emit light in response to excitation light.

Background Art Phosphor screens are made of substances (so-called phosphors) that emit fluorescence or phosphorescence in response to excitation light such as ultraviolet light, visible light, or near-infrared light, such as piperidium tetra(benzoyltrifluoroacetone) europium complex. It is known as a flat plate body made by dispersing and molding a transparent synthetic resin.

In such a phosphor screen, an excitation light beam is projected onto the phosphor screen in the form of a circular spot, causing the phosphor within the spot to emit light, which is used as a pixel to display an image. Therefore, the phosphor screen is used, for example, as a display member of a rear projection type or front projection type image display device. In the rear projection type, an excitation light beam is projected from one side (display back surface) of the phosphor screen and emitted to the other side (display surface) for viewing by an observer. In the front projection type, an excitation light beam is projected from one side (display surface) of a phosphor screen, and light is emitted to the same side so that the viewer can see it visually.

However, because of the flat plate shape of the phosphor screen of a rear projection type image display device, for example, as shown in FIG. The particles are scattered equally in the direction of both sides of the body screen 20 and in the direction of propagation inside the flat plate. Therefore, the utilization efficiency of the projected excitation light becomes low, and the amount of light emitted to the display surface 2Oa side, which is the viewing side, decreases, resulting in a dark screen.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the conventional screen, and provides a phosphor screen that increases the amount of light emitted to the display surface side and improves the brightness of the display surface for the same amount of excitation light. The purpose is to provide

The printed phosphor screen according to the present invention is characterized by comprising an opaque substrate and a plurality of phosphor islands distributed and printed on the substrate.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a partially enlarged sectional view of the printed phosphor screen of this embodiment. This screen is for a front projection type image display device and consists of an opaque substrate 10 and phosphor islands 11 printed thereon.

The substrate 10 is a plate made of paper, metal, wood, etc., and it is preferable that the surface of the plate is not a smooth or glossy surface, but is sufficiently coated with printing ink during printing.

The surface of the plate is preferably painted or impregnated with a dye to give it a dark color, for example black.

The phosphor island portions 11 are obtained by uniformly printing ink made of a high viscosity filler containing the above-mentioned phosphor on the substrate 10 in a dotted pattern. Such printing inks contain phosphors as pigments in a highly viscous filler, i.e. a polymer or oligomeric vehicle. Because of its high viscosity, the phosphor islands 11 have a hemispherical base 11i.
Since it bulges out from 210 and holds sufficient phosphor, when the surface is irradiated with excitation light, fluorescence is emitted uniformly in the front, making it possible to eliminate field-of-view dependence of fluorescence.

The plurality of phosphor islands 11 printed on the substrate 10 may be arranged vertically and horizontally in a scattered dot pattern as shown in FIG. 2, or in a hairline pattern as shown in FIG. They may also be arranged in a pattern.

In this way, in a printed phosphor screen, an image is formed by irradiating excitation light from the viewing side, that is, from above the drawing, as spots corresponding to the phosphor islands, and the amount of light emitted from the viewing side is increased to generate the same excitation light. The brightness of the display surface has been improved relative to the amount of light.

Effects of the Invention As described above, according to the present invention, since the phosphor islands are dispersedly arranged on an opaque substrate, high-intensity light with low viewing angle dependence can be obtained even by the simple method of printing. A phosphor screen is obtained.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention, FIGS. 2 and 3 are partial perspective views of this embodiment, and FIG. 4 is a partial sectional view showing a conventional example. Explanation of symbols of main parts 10... Opaque substrate 11... Phosphor island portion Figure 1 Excitation light Figure 2 Applicant: Pioneer Corporation

Claims (1)

[Claims] A phosphor screen comprising an opaque substrate and a plurality of phosphor islands distributed and printed on the substrate.