JPS59128580A - Large color image display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention consists of three discharge tubes having red, blue, and green light emitting colors, and a large number of these picture elements are arranged side by side. ．． The present invention relates to a large color image display device that displays images by changing the luminance of discharge tubes constituting each picture element, and particularly relates to a configuration for obtaining white balance.

[Technical background of the invention and its problems]

Generally, in a large color image display device, the state where the picture elements emit white light, that is, the state of white balance, is the maximum brightness of each discharge tube in the display device.

Conventionally, various methods have been adopted to obtain white balance. First, there is a method in which the light emitting area of the discharge tube is different for each color, but in this case, the structure of the discharge tube is different, which causes problems in manufacturing and pixel filling, as well as poor color mixing. There was a problem in that the visibility of the display also deteriorated.

There are also devices in which the power supply voltage is changed, but in this case there is a drawback that it becomes difficult to start the discharge tube due to a drop in the power supply voltage.

Furthermore, there are also known devices that control the pulse width and change the rest period of one cycle, but in this case, the pulse width becomes narrower, so the division ratio when dividing the pulse width and dimming becomes worse. There was a drawback.

[Purpose of the invention]

The present invention was developed in view of the above-mentioned drawbacks, and it is easy to manufacture and place the filling inside the picture purple, it does not deteriorate visibility, it can be started reliably, and it also prevents a decrease in the division ratio of dimming. The present invention provides a large color image display device.

[Summary of the invention]

The large color image display device of the present invention uses discharge tubes of the same shape and size and only changes the fluorescent material to display red, red, and red images.
I want to create a blue and green light source, but in this case, color mixing differences occur due to the difference in luminous efficiency of each phosphor and the color difference in visual perception. Therefore, in order to obtain a white balance, the light amount of each color must be adjusted. This was done from this perspective.

For this reason, each picture element is composed of three discharge tubes with the same shape, the same filled gas, and the same gas pressure, but each having different phosphors of red, blue, and green. If the impedance values of the discharge tubes are different such that the brightness ratio of each discharge tube is red: 34.3% to 22.5%, blue: 4.9% to 16.3%, and green: 60.8% to 61.2%. This structure improves the productivity of the discharge tube and the workability of filling and arranging the pixels, and does not adversely affect visibility. .

In addition, since there is no need to reduce the voltage supplied to the discharge tube, problems with starting the discharge tube can be avoided.Furthermore, since the power supply pulse to the discharge tube can obtain white balance in a fully conductive state, the pulse It is possible to avoid inconveniences such as a decrease in the number of gradations unless the accuracy of the width controller is improved, and the cost is 7.
It is an effective dice that can also improve your appearance.

[Embodiments of the invention]

Next, one embodiment of the present invention will be described based on the drawings.

Figure 1 is a diagram showing the display part of a large color video display snowmaking machine.
The display surface (1) has picture elements formed by three fluorescent lamps (3R), (3B), and (3G) as discharge tubes coated with a luminescent material that emits different colors of red, blue, and green. (2) are arranged in large numbers. These light lamps (3R) (
3E) (3G) are all formed to have the same size and shape. As shown in Figures 2 and 3, the shape of all of these lamps (3) is such that the center part of the tube body (4) is bent into a substantially U-shape, and the bases (5) at both ends are placed at the display surface +11. These caps (5) are inserted into and supported by sockets (6) located at the back.

Figure 4 is a block diagram showing the configuration of the display device.

αB is a video tape recorder which receives television signals via receiving antenna A21 and tuner, and also receives TV signals from camera A4.
It directly inputs and records video signals, and then outputs them.

α9 is an image processing device that samples each analog signal corresponding to red, blue, and green output from the video tape recorder αD based on a sampling signal, converts it into a digital image signal, and outputs the digital image signal.

AE is a display control device that controls the image signal from the image processing device α9 so that it can be applied to a predetermined lamp (3) of a predetermined picture element (2).

This lighting device performs dimming control by pulse width modulating the voltage supplied from the DC power supply (18) based on the image signal, and (3R) in each picture element (2).
(3B) (3G) The three fluorescent lamps M-, red, blue, and green, have different values in the current limiting circuit a9, which is a current limiting element.

The configuration of this lighting device (17) will be explained based on Fig. 5.

f211 is the main power supply for 0 seconds of the DC power supply, and outside this main power supply, it is connected to a push-pull type inverter circuit via a dimmer, and the output terminal of this inverter circuit O has a limiter made of inductance. A light lamp (3) is connected via the flow circuit α1. Further, the filament Q41 of this light lamp (3) is connected to a filament power source field of a DC power supply device q8.

The dimmer has a switching transistor and a terminal (
The pulse width changes based on the image signal input from α)! Ii1': A pulse width controller which outputs a signal S and controls the conduction time of the transistor (A).

Further, the inverter circuit includes a constant current reactor, a switching transistor, a feedback resistor C3), a capacitor 01, and an inverter transformer (2).

The configuration of this lighting device a7) includes all picture elements (2).
is the same for all fluorescent lamps (3), but
The inductance of the current limiting circuit 4 is different for the light lamps (3R), (3B), and (3G) that emit light of different colors, and changes the lamp current (IL) supplied from the inverter circuit.

Next, the operation of this embodiment will be explained.

For example, fluorescent lamps of each color (3R) (3B) (3G
), red is y, o, : E, blue is Y2”
Os: Cm, TJ, green is 3 (SrJJ 06P2
05C (IC), B 20 , then change the inductance of the current limiting circuit a9 and change each lamp current (IL) corresponding to each color of dim light lamp (3R) (3B) (3G). The brightness ratio and color temperature at the time of mixing are shown in the table below.
) (3B) (3G) has a tube diameter of 14.5φ■, a lamp effective length of 70u, and the filled gas is mercury and an inert gas such as argon.

In this way, by adjusting each lamp current (crL) and changing the brightness ratio, it is possible to realize a white color that corresponds to various color temperatures. At 4,000°, it is a little reddish, but it is as white as can be obtained with an incandescent light bulb, and at 15,000', it is a little pale, but it is at the limit of what can be called white. Therefore, 4000' to ~15000°
The brightness ratio was set so that K could be obtained.

In addition, the shape and dimensions of all lamps (3) are luminescent color K.
Since they can be made to be the same regardless of the case, manufacturing is easy, and the filling and arrangement of the picture elements (2) can be easily performed, and visibility is not adversely affected. Furthermore, since the power supply voltage can be kept constant and does not vary depending on the lamp (3), there is no problem in starting the lamp (3).

Since the pulse width of the power supply to the lamps (3) can be fully conductive and white balance can be achieved for all lamps (3), even if the minimum pulse width output by the pulse width controller is the same, dimming is possible. The division ratio of can be increased to a real point.

In the lighting device aη of the above embodiment, an inductance is provided independently as the current limiting circuit α9, but the present invention is not limited to this. For example, the inverter transformer may be configured with a leakage transformer, and this transformer c34 )
It is also possible to change the current limiting element by changing the coupling of .

In addition, the inverter circuit power may be any type that can light the fluorescent lamp (3) at high frequency and does not need to be of the push-pull type.

In addition, there are three lamps (3 lamps) in the part before the current limiting circuit σ
R) (rJT8) (3G), and may have a configuration in which one picture element (21K 1 ”) is intersected. However,
In this case, the dimmer @ must be placed after the current limiting circuit α9, but it can be reduced to an inverter circuit, making manufacturing and management easier.

〔Effect of the invention〕

According to the present invention, in order to balance the white color of discharge tubes that emit different colors of red, blue, and green, the shape, filled gas, and gas pressure of each discharge tube are made the same, and the impedance values of the current limiting elements are made different. As a result, the spreadability of the discharge tube and the workability of filling and arranging picture elements can be improved, and visibility is not adversely affected.

In addition, since there is no need to reduce the voltage supplied to the discharge tube, problems with starting the discharge tube can be avoided.Furthermore, since the power supply pulse to the discharge tube can obtain white balance in a fully conductive state, the pulse Inconveniences such as a reduction in the number of dimming divisions unless the precision of the width controller is improved can be avoided, and cost efficiency can also be improved.

[Brief explanation of the drawing]

Figure 1 is a front view showing an embodiment of the large color image display device of the present invention, Figure 2 is a front view showing one picture element, Figure 3 is a side view of a fluorescent lamp, and Figure 4 is a front view showing one embodiment of the large color image display device of the present invention. In the block diagram of the large color video display device, Figure 5 is a circuit diagram of the lighting device. (2)・-Picture element, (3)・・Fluorescent lamp as a discharge tube, (I9＠・Current limiting circuit as a current limiting element.

Claims (1)

[Claims] (1) Each picture element is composed of three discharge tubes having the same shape, the same gas filling, and the same gas pressure, but each having different red, blue, and green phosphors, and the current limiting element for each discharge tube is The impedance values were varied so that the brightness ratio of each discharge tube was red: 34.3-22.5 cm, blue: 4.9%-16.3 cm, green: 60.8%-61.2 cm. A large color image display device characterized by: