JPH0430236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a television receiver suitable for application to a television receiver constituting a large-area video signal display device such as a projector.

BACKGROUND ART AND PROBLEMS The resolution of large-area video signal display devices such as projectors has increased significantly in recent years due to improvements in television receivers (cathode ray tubes, electric circuits) and lenses that constitute them. However, with this increase in resolution, scanning lines, which were not so noticeable in the past, become visible, which impedes improvement in image quality.

In other words, the screen display using the interlaced method is
When there are 525 scanning lines, 262.5 lines constitute one field, and by sending this at 60Hz, surface flicker is suppressed. Further, in order to obtain vertical resolution, as shown in FIG. 1, the next field after a certain field is scanned with a shift of 1/2 scanning line interval. In FIG. 1, lo and le indicate the scanning lines of the odd field and even field, respectively, and Bmo and Bme indicate the electron beams of the odd field and even field, respectively.

However, in this case, even though macroscopically the number of images is 60 per second, microscopically one scanning line lights up every 1/30 second, and the display cycle is 1/30 second. It is. Focusing on point P in Figure 1, this point P
The brightness increases every 1/30 second, as shown in Figure 2.

Therefore, the light emission of one scanning line is visually perceived as flicker.

As an effective means to eliminate this frizz,
Conventionally, as shown in Figure 3, the electron beam Bmo
(Bme) for example, the original odd field scanning line
It has been proposed to make it vertically long so that it spans both lo and scanning lines le of even fields. In this figure 3, the point P is the same as in figure 1.
, the brightness of this point P increases every 1/60 second as shown in FIG. Therefore, by making the shape of the electron beam Bmo (Bme) vertically elongated in this way, each scanning line lo and le is emitted every 1/60 second, and flicker is not perceived.

However, in this way the electron beam Bmo
It is impossible to scan the entire screen with the shape of (Bme) vertically elongated, and the four corners in particular are twisted and become diagonally long, as shown in Figure 5, and the signals overlap in the horizontal direction. This results in deterioration of resolution in the horizontal direction. Also, electron beam
If the shape of Bmo (Bme) is vertically elongated, the slope TR of this luminance cross section will no longer be steep as shown by the broken line in Figure 6, and for example, this will affect not only the N-th scanning line of the same field but also the N+1-th scanning line. This causes a decrease in vertical resolution. What is shown by a solid line in FIG. 6 is a brightness section of an electron beam having a normal shape.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, the present invention is designed to prevent flickering of scanning lines from being felt without deteriorating the resolution.

Summary of the Invention In order to achieve the above-mentioned object, the television receiver according to the present invention has the purpose of enabling electron beams from two cathodes driven by the same video signal to be approximately perpendicularly directed on a fluorescent surface by a correction magnetic field or a correction electric field. It is characterized in that the scanning lines are scanned simultaneously while maintaining positions separated by an interval of 1/2 of the scanning line interval.

The present invention is configured as described above, and the scanning lines of the next field that originally emit light in the next field are also emitted by scanning with the second electron beam, making it possible to cause all the scanning lines to emit light within one field. can. Therefore, the display period of each scanning line is, for example, 1/60 second, and the flicker of the scanning lines will not be felt in the displayed image. Moreover, in the case of the present invention, since the electron beam is not vertically elongated, there is no problem with deterioration of resolution.

Embodiment An example in which the present invention is applied to a television receiver constituting a projector will be described below with reference to FIG.

In the same figure, 1R, 1G and 1B are respectively red,
This is a projection type cathode ray tube for generating green and blue color images S _R , S _G and S _B . Although not shown, the red, green, and blue color images S _R ,
The image lights from S _G and S _B are supplied via a projection lens onto a screen in an overlapping manner, and a color image is displayed on this screen.

The cathode ray tubes 1R, 1G and 1B are each of a two-beam type. That is, the first and second cathodes related to the first and second electron beams Bm ₁ and Bm ₂
K ₁ and K ₂ are provided side by side, and the first and second
The first and second electron beams Bm ₁ and Bm ₂ from cathodes K ₁ and K ₂ are simultaneously scanned on the screen in the vertical direction with an interval of 1/2 of the scanning line interval. For example, as shown in Figure 8,
In the even field, as shown by solid circles in the same figure, the first and second electron beams Bm ₁ and Bm ₂
are the original even and odd field scan lines le, respectively.
and lo, and in odd fields, the first and second electron beams Bm ₁ and Bm ₂ scan the scanning lines lo and le, respectively, as indicated by the dotted circles in the figure. . For example, as shown in FIG. 9, in an even field, the first and second electron beams Bm ₁ and Bm ₂ scan the scanning lines lo and le, respectively, as indicated by solid circles in the figure. , in the odd field, the first and second electron beams are
Bm ₁ and Bm ₂ are arranged to scan scan lines le and lo, respectively.

The cathode ray tubes 1R, 1G and 1B are configured as a Trinitron (registered trademark) type as shown in FIG. 10, or as a two-electron gun type as shown in FIG. It has first and second cathodes K ₁ and K ₂ for two electron beams Bm ₁ and Bm ₂ . 1st
In Figure 0, _G1 to _G5 are grids, CONV is a convergence electrode (electrostatic deflection plate), and DY is a deflection yoke. Moreover, in FIG. 11, G ₁ ~
G ₄ is the grid and DY is the deflection yoke. Further, in FIGS. 10 and 11, 3 is a fluorescent surface.

In order to make the first and second electron beams Bm ₁ and Bm ₂ separated from each other in the vertical direction on the screen, that is, on the fluorescent surface 3 by an interval of approximately 1/2 of the scanning line interval, for example, the first and second electron beams Bm 1 and Bm 2 are electron beams Bm ₁ and Bm ₂
A predetermined magnetic field is applied from the outside to the passage.

Consider the case where the first and second cathodes K ₁ and K ₂ are arranged horizontally side by side. In this case,
On the cathode side of the deflection yoke DY, where the first and second electron beams Bm ₁ and Bm ₂ are separated (therefore, the center of grid G ₄ in Fig. 10 is not possible), in a plane, for example the 12th
As shown in the figure, a horizontal convergence yoke 4 is provided, and as shown in FIG. 13, a vertical convergence yoke 5 is provided. In FIGS. 12 and 13, 6 is a net, x is a horizontal direction, and y is a vertical direction. 1st
The horizontal convergence yoke 4 shown in FIG. 2 includes, for example, a core 4a disposed in the horizontal direction
and 4b, a coil 4c is wound in a predetermined direction, a direct current _SDH of a predetermined magnitude is passed through the coil 4c, and a predetermined magnetic pole is generated on the protruding pieces of the cores 4a and 4b. It is. If the magnetic poles generated on the protruding pieces of the cores 4a and 4b are as shown in the figure, a magnetic field as shown by the broken line will be generated, and the first and second electron beams Bm ₁ and Bm ₂ will be directed toward the paper surface. (), these first
Forces F _1H and F _2H which are opposite to each other in the horizontal direction are applied to the second electron beams Bm ₁ and Bm ₂ .
In this case, by controlling the magnitude of the magnetic field, that is, by controlling the magnitude of the direct current S _DH , the force F _1H
and F _2H vary. Note that if the magnetic poles generated on the protruding pieces of the cores 4a and 4b are opposite to those shown in the drawing, the directions of the forces F _1H and F _2H will be opposite to those shown in the drawing. Therefore, by changing the direct current S _DH , for example, the first and second electron beams Bm ₁ and Bm ₂ can be placed at the same position in the horizontal direction, for example at the center of the fluorescent surface 3.

Further, the vertical convergence yoke 5 shown in FIG. 13 has cores 5a, 5b, 5c and 5d arranged around the net 6 at an angular interval of 90 degrees between the horizontal direction x and the vertical direction y. coil 5
A coil 5e is wound in a predetermined direction, and a DC current _SDV of a predetermined magnitude is passed through the coil 5e, and the cores 5a and 5
Predetermined magnetic poles are generated on the projecting pieces b, 5c, and 5d. Cores 5a, 5b, 5c and 5
If the magnetic poles generated at d are as shown in the figure, a magnetic field as shown by the broken line will be generated, and if the first and second electron beams Bm ₁ and Bm ₂ are directed toward the paper (), then these Forces F _1V and F _2V directed in opposite directions are applied to the first and second electron beams Bm ₁ and Bm ₂ in the vertical direction y. In this case, by controlling the magnitude of the magnetic field, that is, direct current
The forces F _1V and F _2V change by controlling the magnitude of S _DV . Note that if the magnetic poles generated on the protrusions of the cores 5a, 5b, 5c, and 5d are opposite to those shown in the drawings, the directions of the forces F _1V and F _2V will be opposite to those shown in the drawings. Therefore, by changing the direct current S _DV , for example, the first and second electron beams Bm ₁ and Bm ₂ are set at approximately 1/2 of the scanning line interval in the vertical direction at the center of the fluorescent surface 3, for example. They can be separated by an interval of .

In addition, when the first and second cathodes _K1 and _K2 are arranged in parallel in the vertical direction, the convergence yoke 4 shown in FIG. 12 is rotated by 90 degrees and used for vertical use. The convergence yoke 5 shown may be used as is for horizontal purposes.

In addition, as shown in Fig. 14, a twist coil 7 is wound around the neck (not shown), and a DC current is applied to it.
By flowing S _D , a magnetic field in the tube axis direction can be generated. Therefore, as shown in FIG. 15, if the direction of the magnetic field from this coil 7 is A, the first electron beam Bm ₁ is given a (○·) force F ₁₁ directed from the plane of the paper, and the second The electron beam Bm ₂ is given a force F ₁₂ ( ) toward the paper surface. Therefore, this coil 7 has first and second cathodes.
In place of the vertical convergence yoke in the case where K ₁ and K ₂ are paralleled in the horizontal direction, and in place of the horizontal convergence yoke in the case where the first and second cathodes K ₁ and K ₂ are arranged in parallel in the vertical direction Can be used.

Note that due to the assembly precision of the deflection yoke DY and the electron gun, unique misconvergence usually occurs in each cathode ray tube. Therefore, in this example, as shown by broken lines in FIGS. 12 and 13, correction signals S _CH and S _CV are passed through the coils 4c and 5e together with the DC currents S _DH and S _DV , and the fluorescent surface 3
Throughout the above, the first and second electron beams
Bm ₁ and Bm ₂ are corrected so that they are at the same position in the horizontal direction x and separated by approximately 1/2 the scanning line interval in the vertical direction y.

The correction signals S _CH and S _CV are made to differ depending on the mode of misconvergence.

For example, when a horizontal misconvergence as shown in FIG. 16A occurs, a sawtooth wave current having a period of 1 V for one vertical period as shown in FIG. 17A is supplied as the correction signal S _CH . In FIG. 16, the "X" mark and the "O" mark indicate the first and second electron beams Bm ₁ and Bm ₂ , respectively. As described above, the first and second electron beams
Bm ₁ and Bm ₂ are placed at the same position on the fluorescent surface 3 in the horizontal direction x, and are spaced apart from each other by approximately 1/2 of the scanning line interval in the vertical direction y. However, in FIG. 16, for convenience, the first and second electron beams Bm ₁ and Bm ₂ are shown at the same position both in the horizontal and vertical directions. Further, when horizontal misconvergence as shown in FIG. 16B occurs, a parabolic wave current having a period of 1V as shown in FIG. 17B is supplied as the correction signal S _CH . In addition, when horizontal misconvergence as shown in Figure 16C occurs, the correction signal S _CH is
A sawtooth wave current having a period of one horizontal period 1H as shown in FIG. In addition, when horizontal misconvergence as shown in Fig. 16D occurs, the correction signal S _CH as shown in Fig. 17D is used.
A parabolic wave current having a period of 1H is supplied.
In addition, when horizontal misconvergence as shown in Fig. 16E occurs, a sawtooth wave with a period of _1V as shown in Fig. 17E and a 1H
A current with a waveform obtained by integrating sawtooth waves with a period of is supplied. Further, when horizontal misconvergence as shown in FIG. 16F occurs, a current having a waveform integrated with that shown in FIG. 17E is supplied as shown in FIG. 17F. Note that these are typical, and in reality, the current waveforms in each of the above cases are combined to form the correction signal S _CH .

Although the above has been described regarding the correction signal S _CH , the correction signal S _CV can also be considered in the same way.

Further, as shown in FIG. 18, for example, the correction signals S _{CH and} S _CV for each part of the fluorescent surface are written in the memory in advance, and the first and second electron beams Bm ₁ and _Bm It is also possible to sequentially read and supply data corresponding to _{the second} scanning position.

In Figure 18, 8 is nf _H (n is, for example, 5 to 50
represents a signal generator which generates a frequency signal with a frequency of nf _H (an integer of nf _{H, where f H} is a horizontal frequency), from which a signal with a frequency of nf H is supplied to a counter 9 which forms a read address signal. Further, 10 indicates a signal generator that generates a frequency signal of _fH , and the signal of frequency _fH from this is supplied to a counter 11 that forms a read address signal and is also supplied to a counter 9 as a reset signal. . Further, a vertical synchronizing signal V _syoc is supplied from the terminal 12 to the counter 11 as a reset signal. From counters 9 and 11,
Read address signals corresponding to the scanning positions of the first and second electron beams Bm ₁ and Bm ₂ are obtained,
This is supplied to memory 13. Correction signals S _CH and S _CV corresponding to the scanning positions of the first and second electron beams Bm ₁ and Bm ₂ are written in advance in the memory 13, and are sequentially read out based on the address signal. The read correction signals S _CH and S _CV are latched by the latch circuit 14, and then D-
It is converted into an analog signal by an A converter 15, and further passed through a low pass filter 16H, 16V and an amplifier 17.
For example, it is supplied to the horizontal convergence yoke 4 and the vertical convergence yoke 5 through H, 17V.

Furthermore, due to the design of the cathode ray tube, the above-mentioned direct current
S _DV and S _DH may not be necessary. For example, the first
and second cathodes K ₁ and K ₂ are arranged in parallel in the horizontal direction so that the first and second electron beams Bm ₁ and Bm ₂ are at the same position in the horizontal direction, for example at the center of the fluorescent surface 3. If it were, the direct current S _DH would not be necessary. Further, for example, the first and second cathodes K ₁ and K ₂ are arranged in parallel in the vertical direction, and the first and second electron beams Bm ₁ and Bm ₂ are the same in the horizontal direction at, for example, the center of the fluorescent surface 3. position,
If the spacing in the vertical direction is approximately 1/2 of the scanning line spacing, the direct currents S _DH and S _DV are unnecessary.

The cathode ray tubes 1R, 1G, and 1B are configured as described above, and the first and second electron beams Bm ₁ and Bm ₂ from the first and second cathodes K ₁ and K ₂ are scanned in the vertical direction on the screen. They are simultaneously scanned at an interval of 1/2 the line interval.

In this example, the same red primary color signal R, green primary color signal G, and blue primary color signal B are supplied to the first and second cathodes K ₁ and K ₂ of these cathode ray tubes 1R, 1G, and 1B, respectively. Driven.

That is, in FIG. 7, 18 is an antenna, 19 is a tuner, 20 is an intermediate frequency amplifier, and 21 is a video detection circuit. The video signal S _V obtained from this video detection circuit 21 is sent to the luminance signal/chrominance signal separation circuit 22.
is supplied to The luminance signal Y obtained from this separation circuit 22 is supplied to a matrix circuit 23. Furthermore, the color signal C obtained from the separation circuit 22
is supplied to the color demodulation circuit 24. For example, a red difference signal RY and a blue difference signal B-Y are obtained from the color demodulation circuit 24 and supplied to the matrix circuit 23, respectively. The matrix circuit 23 outputs a red primary color signal R, a green primary color signal G, and a blue primary color signal B.

The red primary color signal R is supplied to an adder _26R1 through a gain adjustment circuit _25R1 , a predetermined voltage E _R1 is applied to this adder _25R1 , and this is added, and is supplied to the first cathode _K1 of the cathode ray tube 1R. Ru. Further, _the red primary color signal R is supplied to the adder 26R ₂ through the gain adjustment circuit 25R ₂ .
A predetermined voltage E _R2 is applied to and supplied to the second cathode K ₂ of the cathode ray tube 1R.
In this case, by adjusting the gain with the gain adjustment circuits 25R ₁ and 25R ₂ and adjusting the cut-off by changing the values of the voltages E _R1 and E _R2 , the output from the first and second cathodes K ₁ and K ₂ is adjusted. The intensities of the first and second beams Bm ₁ and Bm ₂ are made to be the same.

Similarly, the green primary color signal G is transmitted through the gain adjustment circuit 25G ₁
A predetermined voltage E _G1 is applied to the adder 26G ₁ to be added thereto, and is then supplied to _the first cathode K ₁ of the cathode ray tube 1G. Further, the green primary color signal G is transmitted to the gain adjustment circuit 25.
It is supplied to an adder 26G ₂ through G ₂ , a predetermined voltage E _{G 2} is applied to this adder 26G ₂ , and the added voltage is supplied to the second cathode K ₂ of the cathode ray tube 1G. Also in this case, the gain adjustment circuit 25G ₁ , 2
By adjusting the gain with _5G2 and adjusting the cutoff by changing the values of voltages E _G1 and E _G2 , the first
and the first emitted from the second cathodes K ₁ and K ₂
and the second beams Bm ₁ and Bm ₂ have the same intensity.

Similarly, the blue primary color signal B is transmitted to the gain adjustment circuit 25.
It is supplied to an adder 26B ₁ through B ₁ , a predetermined voltage E _B1 is applied to this adder 26B ₁ , and the added voltage is supplied to the first cathode K ₁ of the cathode ray tube 1B. Further, the blue primary color signal B is transmitted to the gain adjustment circuit 25.
It is supplied to an adder 26B ₂ through B ₂ , a predetermined voltage E _B2 is applied to this adder 26B ₂ , and the added voltage is supplied to the second cathode K ₂ of the cathode ray tube 1B. Also in this case, the gain adjustment circuits 25B ₁ , 2
By adjusting the gain with _5B2 and adjusting the cutoff by changing the values of voltages E _B1 and E _B2 , the first and second electron beams Bm emitted from the first and second cathodes _K1 and _K2 are ₁ and Bm ₂ are made to have the same intensity.

In addition, in FIG. 7, the video detection circuit 21
The video signal S _V obtained from this is supplied to the synchronization separation circuit 27. The vertical synchronizing signal V _syoc and horizontal synchronizing signal H _syoc obtained from this separation circuit 27 are supplied to a vertical deflection circuit 28V and a horizontal deflection circuit 28H, respectively. And these deflection circuits 28V and 28H
The deflection signals S _VD and S _HD are supplied to the deflection coils 29 of each of the cathode ray tubes 1R, 1G and 1B.

In addition, the synchronization signal obtained from the separation circuit 27
V _syoc and H _syoc are supplied to a convergence circuit 30. In this convergence circuit 30, for example, as described above, a DC current _SDV and a correction signal _SCV are formed which are supplied to the coil 4c of the vertical convergence yoke 4, and a DC current which is supplied to the coil 5e of the horizontal convergence yoke 5 is generated. Currents S _DH and S _CH are formed. Different ones are formed corresponding to each of the cathode ray tubes 1R, 1G and 1B. These signals are transmitted to cathode ray tubes 1R, 1
G and 1B, for example, are supplied to coils 4c and 5e forming convergence yokes 4 and 5, respectively.

This example is configured as described above, and the same red primary color signal R is supplied to the first and second cathodes _K1 and K2 of the cathode ray tube _1R to drive them. The first from cathodes K ₁ and K ₂
The second electron beams Bm ₁ and Bm ₂ are simultaneously scanned on the screen in the vertical direction with an interval of 1/2 of the scanning line interval. Therefore, when there are 525 scanning lines and one beam method is used, within one field
Only 262.5 scanning lines are emitted, but in this example,
The remaining 262.5 scanning lines that would normally emit light in the next field also emit light, making 525 scanning lines in one field, thereby displaying the red image S _R on the screen as described above. .

Furthermore, green image S _G and blue image S _B are similarly displayed on the screens of cathode ray tubes 1G and 1B.

According to this example, the red image S _R , the green image S G and the blue image displayed on the cathode ray tubes 1R, _1G and 1B
Since S _B is displayed by emitting light from all scanning lines within one field, the display period of each scanning line is, for example, 1/60 seconds, and each of these images S _R , S _G and S _B You will no longer experience flickering in the scanning lines. Furthermore, since a vertically elongated beam is not used as in the conventional method, there is no possibility of deterioration in vertical resolution. Therefore, according to this example, a color image with good image quality can be obtained on a screen (not shown).

In the above embodiment, the magnetic vertical convergence yoke 5, horizontal convergence yoke 4, or twist coil 7 is used to control the scanning positions of the first and second electron beams _Bm1 and _Bm2 .
However, the present invention is not limited to this. For example, horizontal and vertical correction plates are provided orthogonally in a cathode ray tube, and a control voltage is applied to these plates to adjust the first and second electron beams Bm. ₁ and Bm ₂
The scanning position may be electrostatically controlled.

Effects of the Invention According to the present invention described above, the scanning line of the next field, which would normally emit light in the next field, is also emitted by scanning with the second electron beam, and all the scanning lines are emitted within one field. Therefore, the display period of each scanning line is, for example, 1/60 second, and the flicker of the scanning lines is not perceived in the displayed image. Moreover, according to the present invention, since the electron beam is not vertically elongated, there is no problem with deterioration of resolution.

[Brief explanation of drawings]

FIGS. 1 to 6 are diagrams for explaining the conventional example, FIG. 7 is a configuration diagram showing an embodiment of the present invention, and FIGS. 8 to 18 are diagrams of the cathode ray tube in the example shown in FIG. It is a line diagram provided for explanation. 1R, 1G and 1B are cathode ray tubes, 23 is a matrix circuit, 30 is a convergence circuit, K ₁
and K ₂ are the first and second cathodes, respectively.

Claims (1)

[Scope of Claims] 1. Electron beams from two cathodes driven by the same video signal are vertically spaced on a fluorescent surface by a correction magnetic field or a correction electric field at an interval of approximately 1/2 of the scanning line interval. A television receiver characterized in that the television receiver is configured to be scanned at the same time while maintaining separate positions.