JPH03170996A - Fluorescent light emitting device - Google Patents

Abstract

PURPOSE:To obtain a uniform light emitting display by providing resistors for color temp. compensation corresponding to the light emission characteristics of a fluorescent light emitting tube body for each of phosphor layers. CONSTITUTION:Electrons are taken out selectively for each of the respective phosphor layers 9R, 9G, 9B by control electrodes 15 and cathodes 14. The electrons are adequately dispersed by diffusing electrodes 16 and while the electrons are accelerated by accelerating electrodes 13, metal bag layers 12 and graphite 11, the electrons are bombarded against the desired phosphor layers 9R, 9G, 9B, by which the light emission display is executed. The resistors 19 for color temp. compensation are respectively connected to the conductors of the control electrodes 15. The resistors 19 discretely adjust the light emission luminance of the respective phosphor layers 9R, 9G, 9B by each of picture elements in such a manner that the color temps. of the respective picture elements enter a prescribed range. The color temps. of each of the respective picture elements are uniformized in this way.

Description

[Detailed Description of the Invention] [Field of Application in Industry E] The present invention relates to a fluorescent light emitting device equipped with pixels made of phosphor layers of different emitting colors, and in particular, the luminance of each emitting color is adjusted to improve the brightness of each pixel. This invention relates to a fluorescent light emitting device with a constant color temperature.

[Conventional technology]

Generally, it is extremely difficult to construct a display device with a large screen, for example, several meters in length and width, using a single display element due to manufacturing technology problems. Therefore, in such cases, the display screen of one display device can be made up of fluorescent light emitting tubes in which one or more pixels are regularly arranged, and by combining a large number of them. It is common to configure

An example of this type of fluorescent light emitting tube is disclosed in Japanese Patent Application Laid-open No. 1-1-0085.
It is disclosed in Publication No. 5. According to this fluorescent luminescent tube,
A display section is provided on one side of the inside of the vacuum container.
The display section is red (R), M (G) . It is equipped with multiple pixels in which three phosphor layers that emit light in the three colors of blue (B) are arranged side by side in a predetermined pattern, allowing for full-color display. Further, inside the vacuum container, a cathode for emitting electrons is provided on the opposite side of the display section, an accelerating electrode is provided near the display section, and a control fII! is provided between the accelerating electrode and the # pole. A pole group is provided.

Electrons emitted from the cathode are selectively made to impinge on each phosphor layer of each pixel, thereby displaying a desired luminescent color.

[Problem to be solved by the invention]

In such a fluorescent light-emitting device, even if each phosphor layer of each pixel is formed under the same conditions and driven to emit light under the same conditions, each color does not necessarily emit light uniformly, and the brightness generally varies. It won't be the same. Therefore, the color temperature of each pixel is not constant, and red (R). I1i (G), blue (B)
There is a problem in that the tone of white, which is displayed by lighting up the three colors simultaneously, is not constant for each pixel.

FIG. 3 is a CIE chromaticity diagram showing classification of JIS color names. As can be seen from the trajectory of blackbody radiation shown in the figure, the color tone changes as the color temperature changes, so if the color temperature of each pixel does not fall within a certain range, the white color will change. The color tone is not constant. Figure 4 shows the MPCD value, which indicates the measure of deviation from the trajectory of blackbody radiation, and the color temperature locus system superimposed on an enlarged view near the center of the CIE chromaticity diagram. According to the conventional fluorescent light emitting device, the chromaticity when each pixel emits white light is, for example, 7,300K to 14.5K in color temperature in the same figure. For example, the OOOK and MPCD values were scattered within a range of 10 fIO. and,
Such a difference in chromaticity is obvious to the human eye and has been observed as non-uniformity in color tone on the display surface.

In order to eliminate such problems, conventional methods have been used to make the white tone of each pixel uniform by adjusting the light emission time of each color in the drive circuit. However, in order to perform correction using such a cantering circuit, a special circuit configuration must be provided, which is costly, and furthermore, the amount of correction differs depending on the fluorescent light emitting device, making it difficult to make adjustments. There was also the problem that it was time-consuming.

(Means for Solving !!Jul) The fluorescent light emitting device of the present invention includes a display section in which pixels having phosphor layers of two or more different emission colors are disposed, a cathode that emits thermoelectrons, An illumination control electrode, which is divided and arranged for each phosphor layer of a different luminescent color corresponding to the pixel, and an acceleration electrode, which accelerates electrons and makes them impinge on the display section, are inside the airtight envelope. The provided fluorescent light emitting device is characterized in that a resistor for color temperature correction corresponding to the light emitting characteristics is connected to each of the control electrodes.

Further, according to the present invention, the airtight envelope and the resistor may be housed in a case to form a module in a state where the display section can be observed.

[For production]

A control electrode provided for each phosphor layer of each pixel is connected to a resistance having an appropriate value corresponding to the light emission characteristics, so that the color temperature of each pixel is uniform.

〔Example〕

This will be explained in detail below using the drawings.

As shown in FIGS. 1 and 2, the fluorescent light emitting device l of this embodiment includes a fluorescent light emitting tube 2, a heat sink 3 disposed on the display side of the fluorescent light emitting tube 2, and a fluorescent light emitting tube 2. It has a case 4 arranged so as to cover the side and rear portions of the vehicle.

First, the configuration of the fluorescent light emitting tube 2 will be explained. In the fluorescent light emitting tube 2, a back plate 5 made of a glass plate or the like, a corresponding front plate 6, and a side plate 7 forming a side part are integrally formed with a sealing material made of a low melting point frit glass or the like. It has a box-shaped airtight envelope 8. The inside of the airtight envelope 8 is evacuated through an exhaust pipe or the like to maintain a high vacuum state. Furthermore, a green light-emitting phosphor layer 9 is provided on the inner surface of the front panel 6 which serves as a display section.
A pixel 10 is formed by disposing a red light emitting phosphor layer 9R and a blue light emitting phosphor layer 9B. Eight pixels 10 are regularly arranged in this fluorescent light emitting tube 2.

Furthermore, around each phosphor layer 9R, 9G, 9B, graphite 11
are provided, and furthermore, on the inner surface thereof, phosphor layers 9R, 9G,
A metal back layer 12 made of AI1Nm or the like is formed to cover the graphite 9B and the graphite 11. An accelerating electrode l3 is provided on the inner surface of this metal back layer 12.

The accelerating electrode 13 is connected to each phosphor layer 9R. It is a grid-like electrode in which openings are formed to correspond to 9G and 9B, and an accelerating voltage of several κV to ten-odd KV is applied.

On the other hand, on the inner surface of the back plate 5, each phosphor layer 9R, 9G. #fi14 is arranged to correspond to 9B. Furthermore, each cathode 1
4, each phosphor N! has a different luminescent color. I9R,9G
, 9B is provided with a control T1 rod 15, each of which is independently driven 11J#. Furthermore, a diffusion electrode 16 is provided between this IIl04 electrode 15 and the acceleration electrode 13. The cathode l4 and the control electrode 15 are surrounded by a diffusion rod 16 to form one unit.

According to the above configuration, electrons are selectively extracted from each of the phosphor layers 9R, 9G, and 9B by the control electrode 8i15 and the cathode 14, and the electrons are appropriately diffused by the diffusion electrode 16, and the acceleration electrode 13 and the metal Back layer 12. Graphite 1! A light emitting display can be performed by causing electrons to strike desired phosphor layers 9R, 9G, and 9B while being accelerated.

Next, on the outside of the back plate 5 of the fluorescent light emitting tube 2, a printed circuit board 17 is provided for routing the lead wires drawn out from the inside of the airtight envelope 8 to a predetermined position. On this printed circuit board 17, conductive wires connected to the lead wires of each of the 11m electrodes 15 described above are also routed. Each of the conductive wires of these control electrodes 15 has a resistor l for color temperature correction.
9 are connected, and each control electrode 15 is connected to the printed circuit board 1.
It is possible to connect to an externally provided drive circuit via each resistor l9 on 7. That is, the fluorescent light emitting tube 2 and the printed circuit board 17 are housed in a box-shaped case 4 whose front side is open, and are modularized. On the back side of the case 4, there is provided a socket R18 in which a plurality of lead bins are arranged in a ring shape. It is connected to each lead wire of the fluorescent light emitting tube 2 via 7.

The resistor 19 individually adjusts the luminance of the phosphor layers 9R, 9G, and 9B for each pixel so that the color temperature of each pixel falls within a predetermined range. In this example, the color temperature of each pixel 10 is 2,500K with a center of 8.700K.
It falls within the range of , and is seen by the human eye as a uniform color tone.

When setting this resistor 19, first prepare several types of resistors, and select a resistor that should be connected to each of the control electrodes 15 of each phosphor layer 9 in accordance with the measured color temperature of the pixel. Decide on your body. Before installing the completed fluorescent tube 2 and printed circuit board 17 into the case 4, a test is conducted for each fluorescent tube 2 to measure the color temperature of each pixel 10.
Depending on the measurement results, an appropriate resistor is selected from among the resistors and connected to a predetermined position on the printed circuit board 17.

In this way, once the color temperature of all pixels 10 of each manufactured fluorescent light emitting tube 2 is kept within a predetermined range, and this is housed in the case 4 together with the printed circuit board 17 to form a module, all that is left is to drive the It is not necessary to add a circuit for adjusting color tone to the circuit, and a large display device can display light with uniform color tone.

In the embodiment described above, resistors prepared in advance were mounted on the printed circuit board 17, but a plurality of resistors were mounted on the printed circuit board 17 so as to be electrically connected to each control electrode 15.
They may also be provided in series via a bypass. Then, by cutting the wiring of the resistor according to the measured color temperature of the pixel, a desired resistance value can be obtained.

〔Effect of the invention〕

According to the present invention, a resistor for color temperature correction corresponding to the light emission characteristics of the fluorescent tube body is provided for each phosphor layer of a different luminescent color constituting each pixel, so that the color temperature of each pixel can be adjusted. Variations can be kept within a certain range narrower than in the past, and a uniform light emission display can thereby be obtained.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of one embodiment of the present invention, Figure 2 is a front view of the same, Figure 3 is a CIE chromaticity diagram showing classification of JIS color names,
FIG. 4 is an enlarged view of the vicinity of the center of FIG. 3. 1... Fluorescent light emitting device, 4... Case, 8-... Airtight envelope, 9.9R. 9G, 9B...phosphor layer, 10... pixel, 13=-acceleration electrode, 14... cathode,
tS-...Control electrode, 19...Resistor.

Claims (2)

[Claims] (1) Divided into a display section in which pixels each having a phosphor layer with two or more different emission colors are arranged, a cathode that emits thermoelectrons, and a phosphor layer with a different emission color corresponding to each of the pixels. In a fluorescent light emitting device, in which a control electrode disposed as a control electrode and an accelerating electrode that accelerates electrons and impinges on the display section are provided inside an airtight envelope, the color temperature correction corresponding to the emission characteristics is used. A fluorescent light emitting device characterized in that a resistor is connected to each of the control electrodes. (2) The fluorescent light emitting device according to claim 1, further comprising an airtight envelope and a case in which the resistor is housed so that the display portion can be observed.