JPS5929944B2 - cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube, and more particularly to a cathode ray tube suitable for a large-screen image display device constructed outdoors or the like.

In recent years, large image display devices have been installed on bank screens in baseball stadiums, and, for example, video images praising batters who hit home runs have been displayed (see examples here).

This image display device requires a high-brightness light source as a pixel element so that it can be viewed from a long distance, and usually high-power, high-brightness incandescent light bulbs are often used, with thousands to tens of thousands of light bulbs. It is arranged so that it is arranged on a plane and is turned on and off using a relay switch or the like to project an image.

However, such an image display device has the following drawbacks.

That is, in order to make a high-power light bulb blink, it is necessary to turn it on and off with a switch, and this operation requires a considerable amount of power.

It is extremely difficult to turn on and off such a large amount of power using an electronic circuit, and it takes a large amount of money to create the device circuit.

Furthermore, due to the time delay in the temperature rise of the filament of the light bulb, it is not possible to display television images by switching at high speed.

Furthermore, because incandescent light bulbs require a large amount of power and there is a time delay in changing the temperature of the filament, it is extremely difficult to perform brightness modulation as quickly as in television images.

In order to construct a multicolor image such as that used in commercial color television broadcasting, it is found that it is extremely difficult to use incandescent light bulbs for the three primary colors with a blue-red edge and to modulate their brightness.

Furthermore, incandescent light bulbs have a short lifespan, usually about 1000 to 3000 hours, which is inferior to the long lifespan of cathode ray tubes, which can last more than 10000 hours, so maintenance and replacement requires a great deal of effort and expense.

The present invention was made in order to eliminate such drawbacks, and an object of the present invention is to provide a cathode ray tube that can be advantageously used in place of conventional incandescent light bulbs for constructing image display devices. This cathode ray tube has a configuration that can effectively utilize the light emitted by the camera.By using this cathode ray tube, it is possible to perform high-speed switching and high-speed brightness modulation with a small amount of power using an electronic circuit, and it also produces images with a long life and reduced maintenance costs. It is possible to construct a display device.

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

FIG. 1 is a schematic diagram showing a schematic structure for explaining the overall structure of an embodiment of the present invention.

Referring to FIG. 1, a tube body 1 is composed of a top body 2 and a top body 3, both of which are joined by a flint seal 4.

Although the upper surface body 2 is made of glass in order to pass light emitted from a fluorescent surface, which will be described later, the upper surface body 3 may be made of glass, ceramic, or metal.

It should be noted that the entire upper body 2 does not need to be made of glass, and it goes without saying that the parts other than the portion through which the fluorescent light emitted may be made of ceramic or metal.

The cathode 6 and the control electrode 1 are visible through the window 5 of the top body 3.

The cathode 6 is placed approximately in the center of the window 5.

A plurality of terminals 8 are installed around the upper surface body 2 for applying an operating voltage to a cathode 6, a control electrode 1 (described later), an accelerating electrode, and the like.

An anode button 9 for applying a high voltage to the fluorescent surface is embedded in the periphery of the upper body 3.

The detailed structure of the above configuration can be understood from FIG. 2, which shows a schematic partial cross-sectional structure.

A cathode 6 is arranged below the window 5 of the upper body 2.

The cathode 6 consists of a heater 10 and an electron emissive material layer 11 coated around the periphery.

Although a directly heated cathode is shown in the figure, it goes without saying that an indirectly heated cathode may also be used.

When viewing a cathode ray tube from a close distance, the cathode 6 is visible;
If constructed as an imaging device, the cathode 6 will not be visible since it will be viewed from a long distance, and the entire cathode ray tube will be regarded as one bright spot, so it will not interfere with the field of view.

A control electrode 1 made of a mesh-like plane electrode is arranged in front of the cathode 6 at a predetermined interval, and an acceleration electrode 12 made of a mesh-like plane electrode is arranged in parallel with a predetermined interval in front of the control electrode 1. is installed.

The accelerating electrode may be composed of a plurality of electrodes. these,
The control electrode γ and the acceleration electrode 12 are held by a support frame 13.

A metal bank 15 is provided on the bottom surface 14 of the upper body 3, and a phosphor layer 16 is applied thereon to form a phosphor surface 1γ.

The fluorescent surface 11 is arranged substantially parallel to the accelerating electrode 12.

The metal back 15 is a film that is connected to the anode button 9 and serves as an electrode for applying a phosphor surface voltage and a function of reflecting light emitted by the phosphor layer 16.

A reflecting plate 19 having a reflecting surface 18 is provided on the side surface inside the tube.

The reflecting plate 19 may be made of metal or other insulating material.

Alternatively, it may be constructed by a method such as applying aluminum vapor deposition to the inner surface of the tube body 1.

The key point is to provide the reflective surface 18 so that the light emitted from the fluorescent surface 11 is prevented from dissipating from the side surface of the tube 1 and efficiently emitted forward through the window 5 of the tube 1.

With the above configuration, a negative voltage is applied to the control electrode γ, a positive voltage is applied to the accelerating electrode 12, and a high voltage higher than the accelerating electrode voltage is applied to the fluorescent surface of the cathode 6.

These voltages are applied to the cathode 6 as shown in FIG.
The emitted electron stream 20 (indicated by a dotted line in the figure) is adjusted so as to form a Fland beam that irradiates the entire fluorescent surface 1γ.

Light emission 21 (indicated by arrows in the figure) from the entire surface of the fluorescent surface 11 passes through the mesh of the accelerating electrode 12 and the control electrode γ, and is emitted to the outside of the tube body 1 through the window 5 of the upper body 2.

Furthermore, the light emitted 22 emitted in a direction that diverges from the fluorescent surface 1γ is reflected by the reflective surface 18, passes through the mensch of the accelerating electrode 12 and the control electrode γ, and is emitted forward from the window 5 of the tube body 2. , the light emitted from the fluorescent surface can be used efficiently.

An image display device is constructed by arranging such cathode ray tubes in a plane.

Images are projected by sequentially modulating the brightness of each cathode ray tube as a pixel component.

The cathode ray tube constructed in this manner has the following features.

In other words, unlike incandescent light bulbs, the brightness can be modulated by changing the potential of the control electrode 1 in the same way as with conventional cathode ray tubes, so pixels can be switched quickly using small amounts of power using electronic circuits, which is useful for television broadcasting. can be projected.

The cathode 6 is strip-shaped and has a large area for emitting electrons, and since the mensch electrode controls acceleration, a large current can be extracted and a bright image can be obtained.

Since the fluorescent surface 1γ can be formed into any shape, the light emitting area efficiency of the image display device can be increased and a bright image can be obtained.

This high luminous area efficiency allows for a more detailed and easier-to-see image than with conventional image display devices using incandescent light bulbs.

Since the bottom surface 14 of the top body 3 can be made smooth, the metal back 1
5 can be mirror-like to improve the reflection performance, and the emitted light 21 of the phosphor layer 16 is efficiently reflected by the metal back 15, resulting in a bright cathode ray tube.

Furthermore, as described above, the light 22 emitted in a diverging manner from the fluorescent surface 11 is also emitted to the front surface of the tube body 2 by the reflective surface 18, so that the pixel can become a bright pixel.

Furthermore, since the phosphor layer 16 of this cathode ray tube is directly irradiated with electrons by the Fland beam, there is no energy loss of the electron beam due to the metal bank, such as the threshold loss caused by the metal bank of a normal cathode ray tube, and the voltage between the fluorescein is eliminated. can be lowered by the threshold value.

Since the fluorescent surface 1γ is arranged at the back of the cathode ray tube, it is easy to cool and is suitable for a large screen image display device constructed outdoors.

Since brightness modulation is possible, by regularly arranging three color cathode ray tubes each coated with red, green and blue 3 CL phosphors, and making a set of three colors into one pixel, the brightness of each tube can be modulated and the color can be changed. It is possible to combine and project a color image.

As described above, the cathode ray tube according to the present invention can efficiently utilize the light emitted from the fluorescent surface, produce bright pixels, can perform brightness modulation, can increase the light emitting area efficiency, can lower the voltage between fluorescent lights, etc. It has many advantages, and if an image display device is constructed using it, it has excellent functions such as being able to display television broadcasts.

It goes without saying that the shapes of the tube, the mesh reflection surface of the electrode, etc. are not limited to those shown in the drawings.

[Brief explanation of drawings]

FIG. 1 is an external view showing a schematic structure for explaining the overall structure of an embodiment of the present invention. FIG. 2 is a schematic structural cross-sectional partial view for explaining the internal structure of the cathode ray tube shown in FIG. FIG. 3 is a schematic structural sectional view for explaining the operating functions of the cathode ray tube shown in FIG. 1. In the figure, 1 is a tube body, 6 is a cathode, γ is a control electrode, 12
1 is an accelerating electrode, 15 is a metal bank, 16 is a phosphor layer, 1
γ is a fluorescent surface, 18 is a reflective surface, and 19 is a reflective plate. In addition, in the figures, corresponding parts are indicated by the same reference numerals.

Claims (1)

[Claims] 1 a cathode, a control electrode disposed in front of the cathode,
an accelerating electrode disposed in front of the control electrode and opposite to the cathode; a fluorescent surface disposed opposite the accelerating electrode; a tube body housing each of the functional elements; a reflector provided within the tube so as to surround the surface;
The cathode has a band-like shape, the control electrode and the acceleration electrode are formed in a mesh shape, and the fluorescent surface has a metal bank formed on the inner surface of the tube and a fluorescent surface coated on the metal bank. The phosphor layer faces the accelerating electrode, and the light emitted from the phosphor surface passes through the mensch-shaped control electrode and accelerating electrode and is emitted to the outside of the tube body. A cathode ray tube characterized in that the cathode ray tube is reflected by a reflective surface of a reflector and emitted outside the tube body.