EP0600325B1 - Cathode ray tube with plurality of guns - Google Patents

Description

The invention is based on a picture tube according to the preamble of claim 1. It is known to create a large screen area with a screen diagonal of ≥ 40 "from EP 0 356 823 A1, in that several cannons are arranged so that a large screen area with In such solutions, shadow masks are used which considerably reduce the efficiency of the brightness and allow the field transitions to be recognized. The deviation of the electron beam and its brightness are not noticed and corrected.

The invention has for its object to provide a picture tube without a shadow mask with a variety of cannons, in which the field transitions are imperceptible. This object is achieved by the invention specified in claim 1. Advantageous further developments are specified in the subclaims.

In the invention, several cannons, depending on the size of the screen, are arranged side by side in the vertical and horizontal directions. The inside of the screen is coated with blue, green and red vertical phosphor stripes and these are separated by opaque stripes, preferably black matrix stripes. In the black matrix stripe areas there are index areas that are used for vertical and horizontal position finding of the beam. The cannons arranged in the vertical direction form a column, and each column has at least one optical sensor to determine the position and the brightness of the beam. In the event of deviations, readjustments are made in the horizontal and vertical directions and the brightness is adjusted so that the sub-picture transitions cannot be seen.

The individual columns are separated by optical walls that are on the inside of the screen, but each cannon writes its own drawing file on the screen. The sequence of the drawing files results on the screen the entire image, in which no partial image transition can be seen due to the brightness-continuous transitions.

No perforated mask is used in the picture tube, so that the efficiency can be increased by a factor of 4 compared to the "shadow masc principle".

Fig. 1

den Prinzipbildschirm der erfindungsgemäßen Bildröhre von hinten betrachtet;

Fig. 2

den Prinzipbildschirm der erfindungsgemäßen Bildröhre von oben betrachtet;

Fig. 3

die Beschichtung eines Bildschirmauschnittes von oben betrachtet und

Fig. 4

die Beschichtung eines Bildschirmausschnittes von hinten betrachtet.

In the following example, the invention is explained with reference to the drawing. The individual figures represent:

Fig. 1

the principle screen of the picture tube according to the invention viewed from behind;

Fig. 2

the principle screen of the picture tube according to the invention viewed from above;

Fig. 3

the coating of a screen section viewed from above and

Fig. 4

the coating of a screen section viewed from behind.

Fig. 1 shows a screen of the picture tube, which is equipped with fifteen mono-beam guns K. The arrangement of three vertical cannons K in a column and the alignment of five columns in the horizontal direction was chosen based on a 16: 9 format to be displayed. The image to be displayed is created by fifteen cannons K, which write the partial images 1.1 to 3.5. The phosphor stripes blue B, green G and red R are arranged vertically next to each other and separated by black matrix stripes BM. The vertical stripe-like arrangement of the phosphor stripes Ph has the advantage, on the one hand, that different line numbers can be projected, and, on the other hand, that it is possible to work with the mono-jet cannons K already mentioned. Since a television picture is usually written with horizontal lines, but here the picture is composed of vertically written lines, electronics with an image memory are to be provided which record the picture with the horizontal lines and output them in vertical lines.

An optical sensor Opt is arranged in the middle of each column in order to determine the position of the individual beams to be able to. The individual columns are separated by optical walls 2, the optical wall having a gap at the beginning and at the end of the column. This gap is used by the adjacent sensor and the sensor of the column concerned, so that the optical sensors Opt perceive the position and the brightness of the adjacent beams and so that an adaptation is made between the partial images. The beam path in a column is synchronous, so that the information about the beginning and end of the column is advantageously used to monitor and, if necessary, adapt the synchronization. The scanned area aB is larger than the visible area sB.

2 shows the picture tube viewed from above, whereby the optical sensor Opt for a column, the deflection yoke 3 of the picture tube and the cannons K can be seen. It can be seen that the angular range to be represented of a cannon is small, approx. 40 ° . For this reason, the picture tube can get by with a smaller depth T. The optical walls 2 separate the columns from each other.

3 shows the coating of a screen detail viewed from above. The vertical phosphor stripes Ph in blue B, green G, red R and the black matrix areas BM are arranged between the glass 4 on the front and the aluminum layer 5 on the back, on which the index areas I are located. The length of a pixel p extends from the center of an index area I to the center of the following index area I in the X direction, with the phosphor stripes blue B, green G and red R in between and a pixel p divided into four equal distances a becomes. It is also possible to integrate the index areas I into the black matrix areas BM.

FIG. 4 shows the coating of the screen detail according to FIG. 3 viewed from behind. In this illustration, the subdivision of the index areas I can be seen, the index areas I being offset by their width and lying on the same optical axis in the vertical direction. The distance between the index areas I is ri, the length yi of an index area I is more than four spot lengths. The light spot or spot S generated by the beam is elliptical, the length of the ellipse being extendable. However, the width of the spot must be adapted to the phosphor stripe Ph. The spot writes the vertical lines one after the other by first writing over the index areas I, then blue B, green G and red R. The index areas are arranged so that if the spot is too far to the left of the vertical direction, the indexes I1 and I3 project more light than index I2 and so that the deviation is measured by the difference in amplitude and readjusted by influencing the beam deflection by the deflection yokes 3. When the spot hits the area ri between two vertical indexes I, no more light is generated, so that the vertical spot position is detected. Since the image information to be written is located in a memory, if a readjustment based on the index areas has been detected, it is changed accordingly, so that the phosphor stripes blue B, green G and red R are controlled correctly. Less video memory volume is required to display an image, since the mono-jet cannon K writes the four stripes very quickly in the vertical direction, but the information required is less than if three cannons write the respective colors. In the case of a color, for example green, only this information is required and the other two phosphor strips blue B and red R are written in black. The very fast spelling of the individual strips is advantageously reduced, since each cannon K only writes one field.

Claims (10)

1. A picture tube having a plurality of guns, in which each gun represents a partial picture, so that an overall picture is formed without partial picture transitions, characterized in that, dispensing with a shadow mask, the interior side of the screen is coated with vertically disposed phosphor colour strips (Ph), which are separated from each other by optically opaque strips (BM) partly upon which are located index regions (I) for vertical and horizontal position finding, in which the guns are constructed as single-beam guns (K) and are arranged in the horizontal and vertical direction and at least one optical sensor (Opt) is associated with the guns (K) lying in the verticals.
2. A picture tube according to Claim 1, characterized in that, for the detection of the position and brightness of the sport, there is provided index regions (I) and optical sensors (Opt).
3. A picture tube according to Claim 1, characterized in that the screen is coated with blue (B), green (G) and red (R) vertical phosphor strips (Ph), and these are separated by optically opaque strips (BM), preferably black matrix strips (BM).
4. A picture tube according to Claim 1, characterized in that index regions (I) are located on or in the optically opaque strips (BM).
5. A picture tube according to Claim 1, characterized in that at least one optical sensor (Opt) is associated with the vertically disposed guns (column).
6. A picture tube according to Claim 1, characterized in that the vertically disposed guns (column) are separated from one another by optical walls (2).
7. A picture tube according to Claim 1, characterized in that the optical walls (2) have gaps.
8. A picture tube according to Claim 1, characterized in that the vertically disposed guns (column) are synchronously controlled.
9. A picture tube according to Claim 1, characterized in that the guns form the partial pictures by vertically deflected beams.
10. A circuit for a picture tube according to Claim 1, characterized in that a picture comprising of horizontal lines is stored in a memory and the memory is read out such that an outputting of vertical lines occurs.

Images