JPS622431A - Image display device - Google Patents

Abstract

PURPOSE:To prevent any image flicker or luminance nonuniformity by stretching all cathode rays in such a manner that the frequency of cathode-ray-driving pulses and the characteristic frequency of the cathode rays are located outside the resonance zone. CONSTITUTION:All cathode rays 11 are stretched in such a manner that the minimum 19a and the maximum 19b of characteristic frequencies of the cathode rays 11 during use are 18a+5Hz and 18b-5Hz respectively. Since the range of the above characteristic frequencies does not coincide with the resonance zone, the cathode rays 11 do not resonate with their characteristic frequeicies and cathode-ray-driving pulse frequencies 18 or their higher harmonics 18a and 18b. Consequently, it is possible to prevent any image flicker or luminance nonuniformity.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an image display device using thermionic emission.

Conventional technology Traditionally, cathode ray tubes have been mainly used as display elements for displaying color television images, but conventional cathode ray tubes have a much longer depth than the screen, making it difficult to manufacture thin television receivers. That was impossible.

In addition, although EL display elements, plasma display elements, liquid crystal display elements, etc. have recently been developed as flat display elements, all of them are insufficient in terms of performance such as brightness, contrast, and color reproducibility of color display. However, it will take time to put it into practical use.

Therefore, we aimed to achieve a device that can display color television images on a flat display device using electron beams, and we divided the screen vertically into multiple sections. The electron beam is vertically deflected for each section to display multiple lines, and
Divide into multiple sections horizontally and print R, G-B for each section.
The R-G-B
With reference to the drawings below, there is a device in which the amount of electron beam irradiation on a phosphor such as the like is controlled by a color video signal, and the entire device is used as a television image display device.
An example of the conventional image display device mentioned above will be explained below.
The conventional technology is shown in Japanese Patent Publication No. 57-33663, but here, FIGS. 4 and 6 show a conventional image display device, the cathode ray drive pulse frequency and cathode ray natural vibration of the image display device. Showing relationships between numbers. In Figure 4,
1 is a cathode ray as an electron beam source, 2 is a support for supporting and fixing both ends of the cathode ray, 3 is a mesh-like control electrode, 4 is a phosphor, 5 is a back electrode, ea and eb are containers, and 7 is a A spring that applies a load to the cathode ray and stretches it; in Fig. 3, 8 is the cathode ray driving pulse frequency, aa and sb are harmonics of the cathode ray driving pulse frequency, 9a is the minimum value of the cathode ray natural frequency, and 9b is the cathode ray natural frequency is the maximum value of

The operation of the image display device configured as described above will be described below.

First, a cathode ray 1 as an electron beam source is stretched horizontally by a plate spring 7 attached to a support base 2 so as to generate an electron beam distributed linearly in the horizontal direction.
A plurality of such cathode rays 1 are provided in the vertical direction at appropriate intervals. These cathode rays 1 are, for example, 10 to 20
An oxide cathode material is coated on the surface of a #mφ tungsten wire. Then, it is controlled at a cathode ray driving pulse frequency of 8 to sequentially emit an electron beam one hour at a time, and a heat current is applied to raise the temperature to generate thermoelectrons at times other than the fixed time. The cathode ray natural frequency corresponds to p9a and 9b depending on the load on the spring 7, heat current, etc. The back electrode 6 has the function of suppressing the generation of electron beams from cathode rays 1 other than the cathode rays 1 that are controlled to emit electron beams for a certain period of time, and pushing out the generated electron beams only in the forward direction. The back electrode 5 may be formed by a coating of conductive material applied to the inside of the rear wall of the container 6. In addition, instead of the back electrode 6 and the cathode ray 1, the mesh-like control electrode 3 is a conductive pair having a horizontally long slit (not shown) facing each of the cathode rays 1, and emits light from the cathode ray 1. The electron beam is passed through the slit and simultaneously deflected vertically or horizontally. Also, a round hole, a slit, or a round hole may be used in addition to the slit. The phosphor 4 is provided with a pair of phosphors in each of the three colors R, G-B for each electron beam that is divided into horizontal directions, and is coated in stripes in the vertical direction. has been done. After the above-mentioned components are inserted into the divided containers 6a and 6b, they are sealed together with adhesive 7 to maintain the internal vacuum.

Problems to be Solved by the Invention However, in the above configuration, as the size of the phosphor 4 increases, the cathode ray 1 becomes longer and becomes more likely to vibrate. For example, the distance between the support parts of the support base 2 of the cathode ray 1 is 10011II! becomes diameter 2
The cathode ray 1 of 0 to 30 μm has a cathode ray drive pulse frequency of 8
When the harmonics 8 & or 8b of the cathode ray 8b and the natural frequency of the cathode ray occur, an amplitude of about ±20 to 20011 m is generated in the cathode ray 1 for a long time. When the cathode ray 1 vibrates, its relative position with respect to the control electrode 3 changes, causing image fluctuations and brightness fluctuations, resulting in image defects fC.

The present invention has been made in view of the above-mentioned problems, and provides an image display device that can provide stable images without vibration of the cathode, has no brightness irregularities, and is of high quality and highly reliable.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention includes:
All the cathode rays are strung so that the cathode ray driving pulse frequency and the cathode ray natural frequency fall outside the resonance zone.

According to the above-described configuration, the present invention eliminates the vibration energy of the cathode rays, eliminates resonance between the cathode ray drive pulse frequency and the natural frequency of the cathode rays, and eliminates the generation of vibrations of the cathode rays.As a result, the image shakes, Luminance unevenness will no longer occur.

EXAMPLE Below, an image display device according to an embodiment of the present invention will be explained with reference to the drawings.0 Figures 1 and 2 show the cathode ray driving pulse frequency and cathode ray natural vibration of an image display device according to an embodiment of the present invention. In Figure 1, which shows the relationship between numbers and the image display device, 1
8 is the cathode ray driving pulse frequency, 1sa and 1sb are harmonics of the cathode ray driving pulse frequency, 19a is the minimum value of the cathode ray natural frequency, and 19b is the maximum value of the cathode ray natural frequency. Further, in FIG. 2, 11 is a conductive cathode wire coated with a substance having thermionic emission function such as barium oxide, 12 is a support base for supporting and fixing both terminals of this cathode wire, and 13 is a wire from the cathode wire 11. An electrode for controlling the emitted beam to form a predetermined image; 14 is the control electrode 1;
16 is a back electrode installed to facilitate the generation of thermoelectrons from the cathode rays 11, 16&, 16b is a container, and 17 is a material that applies a load to the cathode rays. It is a spring that is stretched.

The following is a first explanation of the image display device configured as described above.
The operation will be explained using FIGS. 2 and 3.

When a pulsed voltage is applied to the cathode ray 11 to cause it to emit thermionic electrons, a current flows through the cathode ray 11 during the very minute time when the thermionic electrons are emitted. The temperature of the cathode ray 11 increases by an amount corresponding to the amount of heat generated by the product of , and the cathode ray 11 thermally expands.

When the cathode ray 11 expands, 3C is generated between the support parts of the support base 12.
The tension in the tension of 1 to 45 t changes, and as a result, the cathode ray natural frequency 19 of the cathode ray 11 changes.

This cathode ray natural frequency 19 is the cathode ray driving pulse frequency 1
8 or a harmonic of the cathode ray driving pulse frequency 18a,
18b, resonance occurs, and in the case of the conventional example shown in FIG. 2, the cathode ray 1 generates significant vibration as shown at 20 in FIG. Because of this, there is no damping effect due to air, so vibrations with large amplitudes continue for a long time. In contrast, in the configuration according to the present invention, the cathode ray natural frequency 19 is changed to the cathode ray drive pulse frequency 18 or its harmonics 18a, 1
Since it is outside the resonance zone with 8b, it will not resonate. In this example, the minimum value 19a of the cathode ray natural frequency during use is the cathode ray driving pulse frequency 18a + 5 H
z, if all the cathode rays 11 are stretched so that the maximum value 19b falls within the range of 18b - 5Hz, the cathode rays 11 are shifted from the condition of 20 in Fig. 3, that is, the zone where resonance occurs, so the cathode rays 11 have a cathode ray natural vibration. No resonance occurs between Equation 19 and the cathode ray driving pulse frequency 18 or the harmonics 1ea and 1sb of the cathode ray driving pulse frequency, that is, it was possible to reduce the resonance to 10 μ or less as shown in 21 shown in FIG. In this way, image shake and brightness unevenness are eliminated, and the cathode ray 1
Since no large vibrational energy is applied to 1, reliability is improved and high-quality images can be obtained.

Effects of the Invention As described above, the present invention provides a structure in which the cathode rays are stretched in a zone where the natural frequency during use does not resonate with the cathode ray driving pulse frequency or its harmonics. It does not vibrate with a large amplitude, and it is possible to obtain a high quality image without image shaking or brightness unevenness, and its practical effects are great.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the cathode ray driving panless frequency and the cathode ray natural frequency in an embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view of an embodiment of the image display device according to the present invention.
Figure 3 is a diagram showing changes in amplitude due to resonance of cathode rays, Figure 4
The figure is a partially cutaway perspective view of a conventional image display device, and FIG. 6 is a diagram showing the relationship between cathode ray driving pulse frequency and cathode ray natural frequency in the conventional example. 11... Cathode ray, 12... Support stand, 1
3... Control electrode, 14... Fluorescent material, 1
5...Back electrode, 1ea, 1ab...
Container, 17... Spring, 18...- Cathode ray drive pulse frequency, 18a, 18b... Harmonic of cathode ray drive pulse frequency, 1s a, 19b...
... Minimum and maximum values of cathode ray natural frequency. Name of agent: Patent attorney Toshio Nakao and 1 other person1
1 Fig. 7y---Cathode latent paddy rice pa/shisu round cooking l ridge
qb--~Kyogoku Hodoshuncho 1 gong 1st suuue N Akira (Hz) 3rd rl! J Hz.

Claims (1)

[Claims] A cathode ray that emits thermionic electrons, a control electrode that controls the flow of thermionic electrons emitted from the cathode ray, a phosphor that can receive the thermoelectrons and emit light, and a phosphor that can easily emit the thermoelectrons from the cathode rays. 1. An image display device comprising: a back electrode disposed in a similar manner, and the natural frequency of the cathode ray is adjusted to a range outside a resonance zone between the driving pulse frequency of the cathode ray and the natural frequency of the cathode ray.