JPH0453067B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an index type color picture tube, and more particularly to its structure and its phosphor screen.

[Technical background and problems of the invention]

In recent years, there have been many demands and studies on color picture tubes for use in high-brightness, high-definition, large-sized color picture receivers for high-quality broadcasting, or large-sized ultra-high-resolution graphic display devices for computer terminals.

Higher resolution in color picture tubes can generally be achieved by reducing the diameter of the electron beam spot on the phosphor screen, and conventional methods include improving the electron gun electrode structure or increasing the size, diameter, and elongation of the electron gun itself. However, an electron beam with a sufficiently small diameter spot has not yet been put into practical use.

The main reason for this is that the distance between the electron gun and the phosphor screen becomes longer as the tube becomes larger, and the electron optical magnification of the electron gun becomes too large. That is, in order to achieve larger size and higher resolution, it is important to shorten the distance between the electron gun and the phosphor screen. Furthermore, in this case, the method of shortening the distance between the electron gun and the phosphor screen by wide-angle deflection is not a good idea because it increases the difference in electro-optical magnification of the electron lens between the center and the periphery of the screen.

Furthermore, in order to increase the brightness of color picture tubes, as the tube becomes larger, the electron beam density on the screen surface decreases, resulting in a significant decrease in brightness as the tube becomes larger. Therefore, attempts have been made to increase the anode accelerating voltage or cathode current in shadow mask type color picture tubes, but as a result, the resolution decreases due to distortion of the electron beam spot on the screen surface, and the color changes due to thermal deformation of the shadow mask. High brightness and large size have not yet been achieved at the same time due to various problems such as decreased purity and deterioration of cathode characteristics.

Furthermore, the difficulty in increasing the brightness of such a shadow mask type color picture tube is largely due to the shadow mask itself, and the biggest factor is that the electron beam transmittance of the shadow mask is about 20%.

In other words, about 80% of the total electron beam energy emitted from the electron gun to make the phosphor emit light is lost in the shadow mask, and in reality only a part of the total electron beam energy contributes to the excitation of the phosphor to emit light. This results in a significant decrease in the luminous efficiency of the phosphor relative to the total electron beam energy emitted from the phosphor.

In addition, the energy lost and absorbed by the shadow mask causes thermal deformation of the shadow mask, and the shadow mask, which is originally provided for the purpose of color selection, is not able to fully demonstrate its effect, resulting in a decrease in color purity. .

Therefore, in order to increase the luminous efficiency of the phosphor with respect to the total electron beam energy emitted from the electron gun, the shadow mask was removed, and a color selection was applied to the phosphor screen to create an index stripe and a photoelectric conversion system that received the light emitted from the index stripe. Beam index type color picture tubes have been proposed for a long time, which perform color switching by distinguishing between color picture tubes and other devices.

However, in this type of color picture tube, the diameter of the electron beam spot scanned on the video screen (or the horizontal width of the spot) is required to be less than the width of each color phosphor stripe over the entire screen.

In order to satisfy the conditions for the electron beam spot over the entire screen, a large tube, i.e.
The greater the distance from the screen to the electron gun, the more difficult it becomes.

In other words, in the beam index color picture tube, the luminous efficiency of the phosphor for all the electron beam energy emitted from the electron gun is much higher than in the shadow mask color picture tube, making it easier to realize a high-brightness color picture tube. However, it is clear that it is extremely difficult to extend this method to large pipes.

Here, in addition to the beam index type color picture tube, a small or medium-sized color picture tube is used vertically.
Japanese Patent Laid-Open No. 48-90428 discloses a method for displaying a large screen with high brightness and high resolution by arranging multiple units horizontally.
Utility Model Publication No. 47-9349, Japanese Patent Application Publication No. 48-64872,
This method has been proposed in Utility Model Publication No. 49-26029, etc. This type of method is effective for large screen displays with a large number of divisions, such as outdoors, but in the case of a medium-sized screen display with a display screen size of about 40 inches, the joints of the screen for each division area become noticeable and make the image difficult to see. It is clear that it will be regenerated. Especially for computer-aided design (CAD),
Needless to say, when used as a high-resolution graphic display terminal, the presence of joints in the display screen is a fatal flaw.

[Purpose of the invention]

The object of the present invention has been made in view of the above-mentioned conventional problems, and is to provide a color picture tube that is large in size, has high brightness, high resolution, and is easy to view.

[Summary of the invention]

In the present invention, a plurality of small beam index type color picture tubes are appropriately arranged and integrated into an integrated structure.
The above object is achieved by forming the phosphor of the video screen continuously, and by forming a plurality of types of index stripe phosphors so that they can be easily divided and scanned continuously even at the boundaries of each sub-divided screen. .

[Embodiments of the invention]

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic perspective view of a color picture tube embodying the present invention, and FIG. 2 is a sectional view taken along line XX in FIG.
FIG. 3 is a sectional view taken along YY line in FIG. 1. Figure 1,
2 and 3, the index type color picture tube 1 includes a face plate 3 having a screen portion 2 and a number of nets 5-1, . . . , connected through funnels 4 of the face plate 3.
5-12, a large number of small electron gun units 6-1, . 7-12 and funnel 4
It consists of a transparent light-receiving window 8 and a photoelectric conversion device 9 arranged outside the light-receiving window 8.

FIG. 4 is an enlarged view of the face plate 3 and screen portion 2 shown in FIG. Here, the dashed-dotted line in the center of FIG. 4 indicates the boundary line with the adjacent area when the entire screen section is divided and scanned by the small electron gun section, and the scanning direction is from left to right in FIG. 4.

The screen portion 2 formed on the inner surface of the face plate 3 is formed so as to fill the gap between a large number of phosphors 10 each having three phosphor stripes R, G, and B as one group and the phosphor stripes 10. It consists of a black stripe 11, an aluminum metal back 12 formed by vapor deposition or the like so as to surround both of the stripes, and an index stripe 13 formed at a constant pitch corresponding to the position of the black stripe 11.

The formation pitch of the index stripe 13 is formed at a different pitch from other screen parts near the end of the divided scan of each divided area by each small electron gun section.

In this example, the size of the entire effective screen area is 406.4 mm in width, 304.8 mm in height, and 508.0 mm in diagonal, which is what is called a 20-inch effective screen divided into four parts in the width direction and three parts in the height direction. The size of each divided area is a square with a width and height of 101.6 mm, which corresponds to the size of the effective screen area of a 5.7-inch color picture tube.

In addition, in FIG. 4, the repeating pitch P _S of each color of the phosphor stripe 10 is 0.675 mm, the width T _S of the phosphor stripe 10 is 0.155 mm, and the width T _B of the black stripe 11 and index stripe 13 is 0.675 mm.
0.07mm, index stripe 13 pitch P _A
is 0.45 mm, and the pitch _P of index stripe 13 near the end of divided scanning in each divided area is
The _pitch is 0.225mm, which is 1/2 the pitch of the other screen parts.

FIG. 5 shows the operating principle of this embodiment, and the operating principle will be explained in detail with reference to FIG.

In a conventional one-electron gun type color picture tube, at least one electron beam emitted from a single electron gun is horizontally scanned from position S1 to position S5 using a single deflection system. On the other hand, in the embodiment of the present invention, the position S1 to the position S5 is divided into four to form divided regions 1, 2, 3, and 4, and the electron beam sources G1, G2, G3, G4 and the small Using a deflection system, the entire image is scanned horizontally in four steps, and this horizontal scanning is repeated a plurality of times to reproduce the entire image.

As is clear from FIG. 4, the most important aspect of the present invention is the joining of images of each divided area.

In conventional index-type color picture tubes, the position of each color phosphor can be determined based on the information obtained from the index signal, and the video signal can be switched.The signal applied to the deflection yoke is NTSC.
It was sufficient to synchronize with the horizontal and vertical synchronizing signals in the signal, and the quality of the image, such as continuity and color reproducibility, was hardly affected by changes in the shape of the deflection area.

However, the method in this embodiment uses a deflection yoke,
Including aging of the deflection circuit color picture tube itself,
It is necessary to control the size (shape) of the deflection region with extremely high precision.

For the above-mentioned reason, in this method, in order to emit a light signal of a different pattern from the light signal from the normal index stripe phosphor in each divided picture boundary screen 1B, 2B, 3B, 4B, other screen parts 1A are used. , 2A, 3A, and 4A, the index stripes are formed at different pitches.

In this method, in the divided region 1, the electron beam from the electron beam source G1 is deflected to start deflection scanning from the position S1, and the section 1A is scanned in the same manner as in a normal beam index picture tube. When the electron beam enters section 1B, an index signal of a pattern different from that of section 1A is input, so in this embodiment, when the different pattern starts, the electron beam source G2 of divided area 2 and its deflection are controlled by the fourth index signal pulse. The system alternates scanning and continues with the next scan. Scanning of the following areas is also performed using the same procedure. Here, as a procedure unique to this method, it is necessary to match the time required for scanning each divided area with the reproduction time of the image sent while scanning that area. In a conventional index type picture tube, this corresponds to the amount of deflection deflected in a certain period of time, that is, the control of the raster size during image reproduction. In the conventional index method, in order to determine the point at which to start scanning, an index stripe with a pitch different from that of the screen part is formed outside the effective area of the video screen to determine the scanning start position. Although this method has been proposed, it does not control the end of the horizontal scan (usually the left end of the raster). In actual operation, it is necessary to control and fix either end of the raster (horizontal scanning start point or horizontal scanning end point), and to synchronize the horizontal synchronization signal and horizontal deflection signal of the NTSC signal (or PAL signal, etc.). By taking the image, you can play the entire image without any problems. Here, the point at which the horizontal deflection ends (or the size of the entire raster) only needs to be adjusted once at the beginning.
Even if there is a shift in the horizontal deflection end point (or the overall raster size) due to aging, etc., as long as there is no synchronization shift in the various signal systems, the overall quality of the reproduced image will hardly deteriorate.

However, in the split beam index method of this embodiment, the size of the entire reproduced image and the size of the sub-divided images are set in advance with high precision, so the time required for deflection scanning of each sub-division and the size of each sub-division are The time required to draw the video signal for each part needs to be highly accurate and consistent. In other words, this means that the deflection scanning must be performed by an amount equal to the size of each subdivision in the horizontal direction, coinciding with the time when the video signal of each subdivision is sent.

If the above-mentioned control is not applied to the color picture tube of this system, overlapping of divided pictures, generation of gaps, etc. will occur at the junction of sub-divided pictures, and the quality of the entire image will be significantly degraded.

Therefore, in addition to the conventional method of detecting the position of each color stripe, the index stripe phosphor of this method has a function of detecting the position of the electron beam at a plurality of points during deflection scanning.

Here, a description will be given of control when there is a difference between the time when the video signal of the sub-divided portion is sent and the end time of the deflection scan in the horizontal direction of the sub-divided portion.

In the method of this embodiment, the video signal for one horizontal scan is temporally accurately divided into four, and that time is divided into four parts.
Assuming t ₁ , t ₂ , t ₃ , t ₄ for each region 1 to 4 shown in the figure,
From time t=0 to time t= _t1 , a video signal is applied to the electron beam source G1 regardless of deflection scanning.

From time t= _t1 to time t= _t1 + _t2 , a video signal is applied to the electron beam source G2 regardless of deflection scanning. Similarly, video signals are sequentially applied to each electron source. In addition, the time required for one horizontal deflection scan for each effective image part of each divided area 1 to 4 in FIG. 5 is t _d1 ,
Let t _d2 , t _d3 , and t _d4 . The conditions for the entire video to be completely connected are t ₁ = t _d1 , t ₂ = t _d2 , t ₃ = t _d3 , and t ₄ = t _d4 .

If a time lag corresponding to t ₁ > t _d1 (or t ₁ = t _d1 + Δ ₁ ) occurs, the index of the pitch formed on the screen portion 1B will be changed earlier than when normal operation is performed in area 1. Optical signals from the stripes are detected. By feeding back this deviation from normal operation to the signal amplitude setting circuit of the deflection yoke drive system, the deviation can be corrected.

Another factor in determining the raster size of each divided area is the procedure for determining the scanning start point on the screen. In area 1 of FIG. 5, this can be done by forming an index stripe with a pitch different from that of the screen part outside the effective part of the video screen and determining the scanning start position, as in the conventional beam index method as described above. . In addition, the scanning start points for areas 2, 3, and 4 are determined by
This can be determined by overscanning each area in advance before actually scanning. That is, in the case of area 2, since index stripes of different pitches formed on the screen 1B are stimulated by overscanning position 2, position S2 can be determined by the timing at which the optical signal is output. Hereinafter, positions S3 and S4 can be determined for regions 3 and 4 using the same procedure.

By the above procedure, the deflection signal of the sub-division area can be completely corrected, and the times t ₁ = t _d1 , t ₂ = t _d2 ,
The conditions t ₃ = t _d3 and t ₄ = t _d4 are satisfied, and a high-quality overall image can be reproduced.

Next, the vertical joining of each dividing plane will be explained. FIG. 6 is a diagram showing the formation pattern of index stripes near the division boundary. A stripe is formed on the back surface of the aluminum metal bag 12 to correspond to the black stripe 11.

Since the widths of regions 1B, 2B, 3B, and 4B shown in FIG. 5 of the index stripe 13 are different in vertically adjacent divided regions, the width of the index stripe 1 in the vertically adjacent divided regions is different.
3, the patterns of the optical signals become different. Therefore, the size and position of the raster in the vertical direction can be easily corrected using the same procedure as the size and position of the raster in the horizontal direction.

The above-described correction of the deflection signal may be performed continuously during the actual drawing operation, or may be performed at certain regular time intervals.

In this embodiment, the index stripe phosphor shown in FIG. 4 is formed with completely different pitches in the vicinity of the subdivided image border and in other parts. No problem.

In addition, index stripes of two or more different pitches are formed on the entire video screen,
It may also be possible to make correction of the deflection signal at a plurality of locations simultaneously.

In addition, instead of position detection based on differences in the pitch of the index stripes, the pitch is the same in all screen areas, the phosphor material of the index stripes is changed, and the emission wavelength or emission intensity of the index stripes that emit light partially is changed. Good too.

Furthermore, by using a plurality of photoelectric conversion devices, it is possible to improve the light receiving sensitivity and simultaneously correct multiple divided regions.

This embodiment has been described for the case where real-time operation is performed for signals such as NTSC, but image information for one screen or one line is stored in a frame memory or line memory, and multiple divided planes are simultaneously drawn and scanned. It can also be easily realized.

Further, in this embodiment, the plurality of small electron guns are arranged substantially perpendicular to the screen part, but the small electron guns may be tilted in order to shorten the overall length of the picture tube.

〔Effect of the invention〕

As described above, according to the present invention, the dividing boundary part, which has been considered a disadvantage in conventional split display color picture tubes, is made into an integrated screen part, making it possible to reproduce an easy-to-see image. Adopting a beam index system, the image brightness is extremely high compared to color picture tubes of the same type.Furthermore, although the index system color picture tube of the present invention has a large screen, it has multiple small indexes. Since the color picture tubes are arranged, the depth can be shortened, and the electro-optical magnification of the electron flow is therefore reduced, making it possible to reproduce high-resolution, high-quality images. Furthermore, by creating a difference between the index stripes near the subdivision boundaries of each subdivision screen and the index stripes in other screen parts, it is possible to join and correct the subdivision images.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of the index type color picture tube of the present invention, and FIGS.
The figure is a schematic cross-sectional view taken along X-X' and Y-Y' in Figure 1, Figure 4 is a schematic partially enlarged view showing the face plate and screen part in Figure 1, and Figure 5 is an implementation of Figure 1. FIG. 6 is a schematic diagram for explaining the operating principle of the example, and is a schematic diagram showing index stripes in the vicinity of the division boundary. 1... Index type color picture tube, 2...
Screen part, 3...Face plate, 4...
Funnel, 5...Netsuku Department, 6...Small Electron Gun Department.

Claims (1)

[Scope of Claims] 1. A screen section having a striped phosphor and an index signal generating phosphor, an electron gun section that emits an electron beam that impacts the screen section, a deflection section that deflects and scans the electron beam, and the index. In an indexing color picture tube equipped with a photoelectric conversion device that receives an index signal from a signal-generating phosphor, the electron gun section and the deflection section are arranged separately into a plurality of small electron gun sections and a plurality of small deflection sections, The screen section is divided and scanned into a plurality of small regions by the electron beams in the small electron gun section and the small deflection section, and an index signal from the center of the small region and at least a part near the boundary of the small region are scanned. An index type color picture tube characterized in that it discriminates an index signal. 2. In the index-type color picture tube according to claim 1, the index signal generating phosphor is divided into a screen portion divided into a plurality of small regions by the plurality of small electron gun portions and small deflection portions. An index type color picture tube characterized in that at least a part of the vicinity of the boundary of the small area is formed continuously or discontinuously in a pattern different from that of the area other than the area of the boundary. 3. In the index-type color picture tube according to claim 1, the index signal generating phosphor is divided into a screen portion divided into a plurality of small regions by the plurality of small electron gun portions and small deflection portions. An index type color picture tube, characterized in that a phosphor having a different wavelength or a different emission intensity than areas other than the boundary area is formed in at least a part of the vicinity of the boundary of the small area.