JPS6313186B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multicolor display device, such as a giant display device used particularly outdoors.

Traditionally, giant display devices used for electronic display boards at baseball stadiums, advertising images and messages on the roofs and walls of buildings, and information displays on highways are made by arranging a large number of light bulbs and selectively blinking them. An image is formed by doing this.

In this type of light bulb, the light is obtained from the red heat of the filament of the light bulb, so the light emitted is mainly orange or white-orange. For this reason, it has been quite difficult to generate a large amount of colored light, such as blue or green, from these light bulbs. Furthermore, in order to modulate the brightness of each pixel, it is necessary to turn the applied current to the filament on and off or to vary the applied current, but the frequency response of these light bulbs is usually extremely low, less than 10 Hz, There is a problem in that the emitted light color itself changes due to the electric current, making it unsuitable for displaying intermediate tones or color displays that combine light of arbitrary colors. Additionally, such large display devices typically require 20 to 40W.
In some cases, several thousand to tens of thousands or more light bulbs are required, which poses many problems in terms of power consumption and heat generation.

Therefore, the inventors have previously proposed using a cathode ray tube as a unit light source for the above-mentioned giant display device. This displays a desired image by arranging a large number of small cathode ray tubes with monochromatic fluorescent surfaces such as red, green, and blue.
This not only greatly improves the conversion efficiency of converting electrical energy into light energy compared to light bulbs, but also makes it possible to obtain a light source of any color by selecting the phosphor used. There are advantages. Therefore, it is advantageous when compared to conventional light bulb systems in terms of performance, reliability, maintenance costs, power consumption, etc.

FIG. 1 shows an example of the above-mentioned cathode ray tube used as a light source for a huge display device (Japanese Patent Laid-Open No. 56
-Refer to Publication No. 32661). In the figure, reference numeral 1 denotes a vacuum envelope having a cylindrical shape, for example, for maintaining a vacuum inside the tube. This vacuum envelope 1 has a face glass 3 with a fluorescent surface 2 adhered to the inner surface of one end thereof,
At the other end are an electron gun 4 and an electron gun 4 for irradiating the entire surface of the fluorescent surface 2 with an unfocused electron beam 10.
It has terminals for applying a required voltage to each part of the body, and is closed by a stem part 5. Reference numerals 6, 7 and 8 denote a heater, a cathode and a grid, respectively, constituting the electron gun 4.

To explain the operation of this cathode ray tube, first, a negative voltage is applied to the grid 8 with respect to the cathode 7, and a predetermined current is applied to the heater 6. As a result, the cathode 7 is heated, the voltage of the grid 8 approaches the potential of the cathode 7, and an electron beam 10 is emitted from the cathode 7 toward the fluorescent surface 2. This electron beam 10 is transmitted through a hole 9 provided in the center of the grid 8.
The entire surface of the fluorescent surface 2 is irradiated as an unfocused beam with a predetermined spread θ determined by various conditions such as the diameter of the grid, the distance between the grid 8 and the cathode 7, and the anode voltage. It emits light in a color that corresponds to the phosphor.

For example, as shown in FIG. 2, such cathode ray tubes are regularly arranged with the fluorescent surface facing toward you. Generally, this arrangement consists of 112 cathode ray tubes that emit green light, 12 cathode ray tubes that emit red light, and 13 cathode ray tubes that emit blue light.
are arranged in such a manner that there is one each.

However, for example, when arranging cathode ray tubes with a diameter of approximately 29 mm as shown in Figure 2, consideration must be given to the configuration and wiring of the sockets for supplying various voltages to the cathode ray tubes, as well as the waterproof structure for outdoor use. For example, the pitch of the array will be about 40 to 45 mm, and the optimal viewing distance will be about 70 m or more. Therefore, there is no problem in applications where long-distance visibility is the main focus, such as fan service displays at baseball stadiums, but in applications where close-range visibility is the main focus, such as outdoor advertising, it is necessary to reduce the above visibility distance by half or less. It turns out that there is.

Furthermore, the phosphors used in cathode ray tubes generally have a whitish body color, and for this reason, when used for outdoor displays, the screen becomes unclear under strong skylight in broad daylight. There are drawbacks.

Furthermore, as another conventional example, a color display device is known in which the fluorescent surface of one arc tube is divided into three parts: red, green, and blue (see, for example, Japanese Utility Model Publication No. 39-22214).

However, in the above color display device, red, green,
Since each blue color has the same emitting area,
Even when a large display is constructed by arranging a large number of the above-mentioned arc tubes, the numbers of red, green, and blue pixels are the same. For this reason, green pixels cannot be emphasized, and the effect of increasing the sharpness of the image as shown in FIG. 2 above cannot be obtained.

Furthermore, one arc tube requires phosphor surfaces of three colors and three electron guns for irradiating electron beams to each phosphor surface, resulting in an increase in the number of parts and a disadvantage that the structure becomes complicated.

This invention provides optimal visibility of the display by dividing the fluorescent surface of a cathode ray tube, which serves as the pixels of a giant display device, into a plurality of parts to create a multicolor display, and by forming the substrate glass of the fluorescent surface from a specific material. It is an object of the present invention to provide a multicolor display device that significantly shortens the distance and provides a clear screen even under strong sky light when used outdoors.

In order to achieve the above object, the multicolor display device of the present invention includes a plurality of electron guns that generate unfocused electron beams housed inside a vacuum envelope, and an anode that constitutes an anode electrode portion of the electron gun. A fluorescent surface is provided at each tip of the tube, and the fluorescent surface is
It is formed on a glass plate containing 3.0 to 15.0% by weight of Nd ₂ O ₃ (neodymium oxide), and is characterized in that the glass part of the envelope also contains 3.0 to 15.0% by weight of Nd ₂ O ₃ It is said that

An embodiment of the present invention will be described below with reference to the drawings.

First, the basic principle of this invention will be explained.

In FIG. 3, 21 is a vacuum envelope;
2r, 22g, 22b are electron guns housed inside the vacuum envelope 21, 22r is red, 22g
corresponds to green, and 22b corresponds to blue. 23
r, 23g, 23b are the above-mentioned electron guns 22r, 22
g, 22b is an anode cylinder that constitutes the anode electrode part, and the tip of each is coated with 3.0 to 15.0% by weight.
Glass plates 24r, 24g, 24 containing Nd ₂ O ₃
b is attached. These anode electrodes 12a, 12
The base end portions of the electron guns 4a and 4b are arranged opposite to the cathodes of the electron guns 4a and 4b, respectively. 25r, 25g, 25b
is a red color formed on the glass plates 24r, 24g, 24b by a silk screen method or the like;
Green and blue fluorescent surface, unfocused electron beam 26
It emits light when irradiated with r, 26g, and 26b.

As shown in the above basic principle, the multicolor display device of the present invention has fluorescent surfaces 25r, 25 as shown in FIG.
g, 25b and glass plates 24r, 24g, 24b
Since the electron guns 22r, 22g, and 22b are integrally formed, the cathode ray tube can be easily assembled by simply enclosing these integrally molded parts in the vacuum envelope 21, and productivity can be improved.

Further, the glass material of the vacuum envelope 21, and
As a substrate glass material for the fluorescent surface provided at the tip of the anode tube of the electron gun, that is, the fluorescent target,
Glass containing Nd ₂ O ₃ is used. This imparts wavelength selectivity to the spectral transmittance of the glass, and as a result, it is possible to maximize the absorption of external light and significantly suppress the loss of luminous energy of the phosphor, which is used in display devices. The contrast of the screen can be greatly enhanced. Moreover, the above Nd ₂ O ₃ is contained in the vacuum envelope 21
Since Nd 2 O 3 is contained in both the glass plates 24r, 24g, and 24b, even if the content per unit volume of Nd 2 O ₃ is reduced, the amount of Nd ₂ O 3 in the entire cathode ray tube is
As the content of Nd ₂ O ₃ increases, wavelength selectivity improves. Therefore, the transmittance of red, blue, and green is significantly increased, and the contrast is improved. Therefore, by using this cathode ray tube, the display quality of the display outdoors in broad daylight can be greatly improved.

This Nd ₂ O ₃ content is 3.0 to 15.0 as mentioned above
It is preferable that the amount is within the range of % by weight; if it is too small, a sufficient effect will not be obtained, and if it is too large, it will cause a decrease in the meltability of the glass and a change in the coefficient of thermal expansion, which is not preferable. Furthermore, the optimum content of Nd ₂ O ₃ mentioned above varies depending on the thickness of the glass plate, so productivity, quality,
It may be determined as appropriate depending on the thickness of the glass plate, which is determined from the viewpoint of economical efficiency and the like. For example, if the glass plate is around 2 mm, the Nd ₂ O ₃ content is 5 to 8% by weight.
is optimal. FIG. 4 shows the spectral transmittance when a glass plate with a Nd ₂ O ₃ content of 6.5% by weight and a thickness of 2 mm is used. In the multicolor display device of the present invention, the phosphor surface may be divided into, for example, a fan-shaped division starting from the center as shown in FIG. In other words, inline arrangement type 32 can be mentioned. As shown in FIG. 3, this type of division can be set in various ways depending on the arrangement of the three electron guns housed inside the vacuum envelope, that is, the arrangement of the fluorescent surfaces.

As is clear from FIGS. 5 and 6, in the multicolor display device of the present invention, each cathode ray tube is multicolor, so the size and arrangement pitch of the cathode ray tubes are the same as in FIG. Even if it is the same, the light emitting units that become pixels are small and close together,
As a result, the optimal viewing distance for large displays is significantly reduced. Therefore, the multicolor display device of the present invention is extremely suitable for use in a large display device that is viewed from a short distance.

Additionally, if glass containing Nd ₂ O ₃ is used as the glass material constituting the vacuum envelope itself, the above
The content of Nd ₂ O ₃ is 3.0 to 15.0 for the same reason as in the case of the glass plate of the fluorescent target mentioned above.
A range of % by weight is desirable.

The principle of this invention has been explained above, and based on this principle, in the embodiments of the invention, a glass plate is
3.0 to 15.0% by weight of Nd ₂ O ₃ and 3.0 to 15.0% by weight of Nd ₂ O ₃ are contained in the cathode ray tube.
It has a color-divided configuration, with a first cathode ray tube divided into red and green, and a second cathode ray tube divided into blue and green, arranged appropriately to form a huge display. This embodiment also provides the same effect as the basic principle of dividing into three colors.

As explained above, according to the present invention, the fluorescent surface, the glass plate, and the electron gun are integrally formed, so that a cathode ray tube can be easily manufactured by simply enclosing these integrally molded products in a vacuum envelope. can be assembled,
Productivity will be improved.

Furthermore, by dividing the inside of one cathode ray tube into two parts, red and green, or blue and green, green pixels, which dominate the resolution of the image, are emphasized. Therefore, the sharpness of the image is greatly increased, the optimum viewing distance of the giant display is significantly shortened, and an easily viewable image can be obtained.

Furthermore, both the vacuum envelope and the glass plate are
Since the cathode ray tube contains Nd ₂ O ₃ , the amount of Nd ₂ O ₃ contained in the cathode ray tube increases, and the contrast is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a light source cathode ray tube with a monochromatic fluorescent surface, and FIG. 2 is a schematic diagram showing a display arrangement of light source cathode ray tubes with a monochromatic fluorescent surface.
FIG. 3 is a schematic sectional view showing a cathode ray tube for a polychromatic light source according to an embodiment of the basic principle of the present invention, and FIG.
A characteristic diagram showing the spectral transmittance of a glass plate containing Nd ₂ O _3. FIG. 5 shows an arrangement for a display of a cathode ray tube for a tricolor light source according to the basic principle of the present invention, which has a divided phosphor surface in a delta arrangement. FIG. 6 is a schematic diagram showing a display arrangement of a cathode ray tube for a trichromatic light source according to the basic principle of the present invention, which has divided fluorescent surfaces arranged in-line. 21...Vacuum envelope, 22r, 22g, 22b
...electron gun, 23r, 23g, 23b...anode tube, 24r, 24g, 24b...glass plate, 25
r, 25g, 25b...fluorescent surface, 26r, 26
g, 26b... unfocused electron beam.

Claims (1)

[Scope of Claims] 1. An anode tube whose tip supports a fluorescent surface target in which a transparent glass plate is coated with a luminescent color phosphor;
Two assemblies are provided in the envelope, each consisting of an electron gun that is provided at the base end opposite to the tip of the anode tube and irradiates the fluorescent surface target with an electron beam, and includes the transparent glass plate and the electron gun. A cathode ray tube in which the glass portion of the envelope contains 3.0 to 15.0 weight percent of Nd ₂ O ₃ , wherein the assembly is coated with a red light emitting phosphor and a green light emitting phosphor is coated thereon. a first cathode ray tube comprising the above assembly; and a second cathode ray tube comprising the assembly coated with a blue-emitting phosphor and the assembly coated with a green-emitting phosphor. A multicolor display device comprising a plurality of pairs of the first and second cathode ray tubes arranged adjacent to each other.