JPS6018083A - Television receiver - Google Patents

Abstract

PURPOSE:To prevent the deterioration of vertical image resolution by detecting the vertical correlation from the present video signal and video signals preceding and following by a horizontal period to the present signal and performing the scan with coincidence obtained between two electron beams in case the non- correlation has the value higher than a prescribed level. CONSTITUTION:A video signal SV is separated into a luminance signal Y and a color signal C by a Y/C separating circuit 22. The signal Y is delivered to a correlation detecting circuit 100. The circuit 100 detects the non-correlation value between the present video signal and another video signal which is preceding or following by a horizontal period to the present signal and then set an output signal SC at ''0'' when the non-correlation value is lower than a prescribed level. Each of projection type CRT 1R-1B which produce red, green and blue pictures respectively has two electron beam generating sources K1 and K2 to perform the non-interlace scan on a fluorescent screen. In case the vertical correlation is weak and the signal SC is set at ''0'', the coincidence is obtained with control on a fluorescent screen between two beams to perform an interlace display. Thus it is possible to avoid the deterioration of vertical image resolution at the area where the vertical correlation is weak.

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 been significantly improved in recent years due to improvements in television receivers (cathode ray tubes, electric circuits) and lenses that constitute them. However, along with this improvement in resolution, scanning lines, which were not so noticeable in the past, become visible, which hinders the improvement of image quality.

In other words, if the screen display using the interlace method has 525 scanning lines, one field consists of 262.5 lines, which is 601! Screen flicker is suppressed by sending the image in z. Further, in order to obtain vertical resolution, the scanning is performed in the next field after a certain field with a shift of ten scanning line intervals.

However, in this case, even though macroscopically it is a function of 60 frames per second, microscopically one scanning line lights up every second, and the display cycle is a gauze.

Therefore, when the point of gaze moves following the movement of the image, there is a drawback that the structure of every other Cf line of field (2) stands out.

As an example of eliminating the roughness of this scanning line structure, for example, the conventional 2
An example of non-interlaced display using a beam type cathode ray tube has been proposed.

That is, in a two-beam type cathode ray tube, the J-th and second electron beams are simultaneously scanned in the vertical direction on the phosphor surface at an interval of L-, which is the scanning line interval in the interlaced type.

When there are 525 scanning lines, in this 2-beam system, 1
All 525 scanning lines can be emitted within the field, non-interlaced display can be performed, the roughness of the scanning line structure described above can be reduced, and an image with good texture can be obtained.

However, this 2-beam system that performs non-interlaced display has the disadvantage that the vertical resolution deteriorates in vertically uncorrelated parts of the image.

For example, in the interlace system, when the scanning lines of the first field and the second field are as shown in FIG. 1A and B, respectively, the luminance obtained by combining these two fields is as shown in FIG. 1C.

Here, the solid and broken lines indicate the first and second defects, respectively.
It shows the brightness according to the scanning line of the field. In this case, the rise to the own level and the fall from the own level are performed at the interval between adjacent scanning lines.

On the other hand, when the scanning lines in the interlace method are as shown in FIGS. 1A and B, in the 2-beam method, the first field and The scanning lines of the second field are as shown in FIGS. 2A and 2B, respectively.

The luminance obtained by combining these two fields is as shown in C in the figure. Here, the solid line and the broken line indicate the luminance by the scanning lines of the first and second fields, respectively. In this case, rising to the white level and falling from the white level are performed at intervals of one scanning line.

In this way, in the case of the 2-beam system, the brightness changes become slow in the vertical non-correlation portion, resulting in poor vertical resolution.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and is intended to prevent the above-mentioned deterioration of vertical resolution in the 2-beam system.

Summary of the Invention In order to achieve the above object, the present invention detects vertical correlation from the current video signal and the video signals before and after one horizontal period, and when the vertical decorrelation exceeds a predetermined value, the fluorescent surface The two electron beams are scanned in unison at the top.

The present invention is configured as described above, and since interlace scanning similar to the conventional technique is performed in the vertical decorrelation portion, deterioration in vertical resolution caused by non-interlace scanning in the vertical decorrelation portion is prevented.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG. This example is an example in which the present invention is applied to a television receiver constituting a three-tube projector.

In the figure, (II?), pages IG) and (IB) are projection type cathode ray tubes for generating red, green and blue color images SR, sG and sB, respectively. Although not shown, each color image sR,' of red, blue, and red generated on each screen is
The image lights from sG and SB are supplied to a screen 2 through a projection lens, and a color image is displayed on this screen.

The cathode ray tubes (IR), (IG), and (IB) are each of the two-beam type. That is, 1 and 2 are provided side by side on the first and second cathodes of the first and second electron beams Bm1 and 8m2, and the first and second electrodes from 1 and 2 are provided on the first and second cathodes. The second electron beams Bm1 and 8m2 are simultaneously scanned on the screen in the vertical direction with an interval of + of the scanning line interval. For example, as shown in FIG. 4, in an even field, the first and second electron beams I1mx
and BIT12 scan the scanning decorations pe and No of the original even and odd fields, respectively, and in the odd field, the first and second electron beams Bm1 and 8m2 each has 11 scanning lines
° and βC are scanned. For example, as shown in FIG. 5, in the even field, the first and second electron beams Bmx and 8m2 scan the scanning lines pO and βe, respectively, as shown by solid circles in the figure, and in the odd field, In the field, the first and second electron beams BI111 and 8m2 scan the scanning lines (le and β0, respectively) as indicated by the broken line circles in the figure.

This cathode ray tube (IR), (IG) and (IB)
It is configured as a Trinitron (registered trademark) type as shown in the figure, or as a 2'fAi subgun type as shown in Figure 7, but in any case, the first and second electron beams Bnu and 8m2 are 1 and K2 at the first and second cathodes. In Fig. 6, Gi~
G5 is the grid, C0NV is the convergence electrode (
(electrostatic deflection plate), DY is a deflection yoke. Also, the seventh
In the figure, 01 to G4 are grids, and DY is a deflection mark. In addition, in Fig. 6 and Fig. 7 1, (3
) is a fluorescent surface.

In order to make the first and second electron beams B1111 and BII+2 separated from each other in the vertical direction on the fluorescent surface (3), for example, the first and second electron beams B1111 and BII+2 are A predetermined magnetic field is applied from the outside to the paths of the electron beams Bm1 and 8m2.

Consider the case where the first and second cathodes Ki and 2 are arranged side by side in the horizontal direction. In this case, G is located on the cathode side of the deflection yoke DY, where the first and second electron beams Bm1 and l1m2 are separated (therefore, the center of the grid nod G4 in FIG. 6 is not possible). In a plane perpendicular to the axis, for example, as shown in Fig.
A convergence yoke (4) is provided, and a vertical convergence yoke (5) is also provided as shown in FIG.

In FIGS. 8 and 9, (6) is the neck, X indicates the horizontal direction, and y indicates the vertical direction. 8th
For example, the horizontal convergence yoke (4) shown in FJI is a core (4) arranged in the horizontal direction
4a) and (4b) A coil (4C) is wound in a predetermined direction, and a direct current SDH of a predetermined magnitude is passed through the coil (4C), and the core (4a) and (4b) are wound in a predetermined direction.
) has a predetermined magnetic pole generated on the protruding piece. Assuming that the magnetic poles generated on the protruding pieces of 21A (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 Binz and B
Assuming that IT12 is forcefully moving toward the paper surface (■), forces FiH and F2O in opposite directions in the horizontal direction of G are applied to the second and second electron beams Bmx and 8m2.

In this case, by controlling the magnitude of the magnetic field, that is, by controlling the magnitude of the DC current SDH, the forces FIH and F
2O varies. In addition, if the magnetic poles generated on the protrusions of the cores (4a) and (4b) are opposite to those shown in the figure, the force F
The directions of tH and F2O are opposite to those shown in the figure.

Therefore, by changing the direct current SDo, it is possible to make the first and second electron beams Bmr and OζBm2, for example, at the same position in the horizontal direction at, for example, the center of the fluorescent surface (3).

The vertical convergence yoke (5) shown in FIG.
5a), (5b), (5C) and (5d) A four-coil coil (5e) is wound in a predetermined direction, a DC current SDV of a predetermined magnitude is passed through this coil (5e), and the core (5a)
, (5b), (5C), and (5d) have a predetermined magnetic pole generated. Core (5a), (5b
), (5C) and (5d), , 4 If the generated and known magnetic poles are as shown in the figure, a magnetic field as shown in Hakfunen Izumi will be generated, and the first & vJ2 electron beams Bm , and 8 m2 are facing the plane of the paper (■), then these first and second electron beams B+y+s skin 8m2j are the forces F 1v and ' F 2 which are opposite to each other in the vertical direction y.
V is given forcefully. In this case, the magnitude force of the magnetic field (by being controlled, that is, the magnitude force of the DC current Spv <ili'
l? The forces F lv and F 2V change by being applied. surface, core (5a), (5b), (5C) and (
If the magnetic poles generated in 5d) are opposite to those shown in the figure, the directions of F 1v and F 2v will be opposite to those shown in the figure. By changing the direct current SDV,
nn and 8 m2 can be placed, for example, at the center of the phosphor surface (3) in the vertical direction G (1-1) so as to be separated by an interval approximately equal to the scanning line interval.

In addition, when the first and second cathodes are arranged vertically in parallel, the convergence yoke (4) is rotated 90 times! The convergence yoke (5) shown in Fig. 9 is used for vertical use.
can be used as is for horizontal use.

Furthermore, as shown in FIG. 10, a magnetic field in the tube axis direction can be generated by winding a twist coil (7) around the neck (not shown) and passing a direct current SO through it.

Therefore, as shown in FIG. 11, if the direction of the magnetic field from this coil (7) is A, a force Fcp directed toward the first electron beam Bmi from the plane of the paper ((E)) is applied,
The second electron beam 13m2 has a (■) force F directed toward the paper surface.
ce is given. Therefore, this coil (7)
And in the case where 1 and 2 are arranged horizontally in the second cathode, instead of the vertical convergence yoke,
In the case where the first and second cathodes 1 and 2 are arranged in parallel in the vertical direction, it can be used in place of a horizontal convergence yoke.

Due to the assembly precision of the surface, deflection yoke l)Y, and electron gun, it is common for each cathode ray tube to have its own misconvergence. Therefore, in this example, as shown by broken lines in FIGS. 8 and 9, DC current SDH and Snv
At the same time, the correction signals SCH and SCV are Koino! ;(4C)
and (5e), and the first and second electron beams Bmz and Bmz are at the same position in the horizontal direction X and at the same position in the vertical direction y over the entire surface of the fluorescent surface (3). The scanning lines are corrected so that they are spaced apart by approximately the scanning line spacing.

The correction signals SCH and Scv are made to differ depending on the mode of misconvergence.

For example, when horizontal misconvergence as shown in FIG. 12A occurs, the correction signal 5C)l is used as shown in FIG. 13A.
A sawtooth current having a period of one vertical period (1v) as shown in FIG. In FIG. 12, the [x] mark and the [o] mark indicate the first and second electron beams Bm1 and BIT12, respectively. As mentioned above, the first and second electron beams Bmx and 8m2 are connected to the fluorescent surface (3).
In the above, in the same position in the horizontal direction
However, in FIG. 12, for convenience, the first and second electron beams Bmi and 8m2 are shown at the same position both in the horizontal and vertical directions. Furthermore, when horizontal misconvergence as shown in FIG. 12B occurs, a parabolic wave current having a period of 1 V as shown in FIG. 13B is supplied as the correction signal SCH. Furthermore, when horizontal misconvergence as shown in FIG. 12C occurs, a sawtooth wave current having a period of one horizontal period (LH) as shown in FIG. 13C is supplied as the correction signal SCH. . In addition, when horizontal misconvergence as shown in Figure 12 occurs, a correction signal SCH of 111 as shown in Figure 13 is used.
A parabolic wave current having a period of is supplied. In addition, when horizontal misconvergence as shown in FIG. 12E occurs, a sawtooth wave with a period of 1V and a sawtooth wave with a period of il+ as shown in FIG. 13E are multiplied as the correction signal SCH. A current with a waveform is supplied. Further, when a horizontal misconvergence as shown in FIG. 12F occurs, a current having a waveform integrated with that shown in FIG. 13E is supplied as shown in FIG. 13F. Please note that these are typical
Actually, the current waveforms in each case described above are combined to form the correction signal SCH.

Although the above has been described regarding the correction signal ScH, the correction signal Scv can also be considered in the same way.

Further, the correction signals SCH and Scv are, for example, the 14th and 1st
As shown in FIG. 3, the complementary signals SCH and Scv for each part of the phosphor screen can be written in advance in the memory, and read out and supplied sequentially corresponding to the scanning positions of the first and second electron beams BIT11 and BIT12.

In FIG. 14, (8) is nfH (rt is G or 5
-50 integer, fH is horizontal frequency) indicates a signal generator that generates a frequency sequence/number of nfH, and the signal of j frequency of nfH from this is sent to a counter (9) which forms a read address signal. Supplied. In addition, 00) indicates a signal generator that generates the fH frequency (No. 1), and the signal of the fH frequency from this is read at, and the response (if No. -3 is generated).
is supplied to the counter (11) and the counter (9
) as a recent signal. In addition, the terminal (12
) is supplied to the counter (11) as a 1 noset signal to the vertical synchronization signal V5sync. Read address signals corresponding to the scanning positions of the first and second electron beams Bmt and 0ζBm2 are obtained from the counters (9) and (li), and are supplied to the memory (13). The memory (13) stores the first and second electron beams Bm1 and Bm8.
Correction signal 5C) I and SCV corresponding to the scanning position of m2
are written in advance, and are sequentially read out based on address signals. This read correction signal SCH
and SCV are launched by the latch circuit (14), and then I
) - A converter (15) converts it into an analog signal, and then passes it through a Nirohas filter (1611), (16V) and amplifier (17H):, (17V) to, for example, a horizontal convergence yoke (4) and a vertical convergence yoke (5). ).

Depending on the design of the cathode ray tube, the above-mentioned DC currents Sov and SpH may not be necessary. For example, the first and second
The electron beams 1 and 2 are arranged horizontally in parallel on the cathode of the fluorescent surface (3), so that the first and second electron beams Bnn and BI112 are at the same position in the horizontal direction, for example at the center of the fluorescent surface (3). If so, the direct current SDI is not required. Further, for example, the first and second cathodes 1 and 2 are arranged in parallel in the vertical direction, and the first and second electron beams Bmz and 8m2 are horizontally arranged at the middle 1 and the like of the fluorescent surface (3). On the other hand, if they are placed at the same position and at an interval of + approximately the scanning line interval in the vertical direction, the DC main current SD
H and Sov are unnecessary.

In addition, the above describes the first and second electron beams 11m1 and 8
The method using a magnetic vertical convergence yoke (5), horizontal convergence yoke (4), or twist coil (7) to control the scanning position of m2 was shown.
Without being limited thereto, for example, horizontal and vertical correction plates may be provided orthogonally within the cathode ray tube, and a control voltage may be applied to these plates to produce the first and second electron beams Bm+ and 8.
The scanning position of m2 may be electrostatically controlled.

The cathode ray tubes (IR), (IG) and (IB) are constructed as described above, and the first and second electron beams Bm1 and 8m2 from the first and second cathodes Ks and 2 are vertically aligned on the screen. The images are simultaneously scanned at intervals equal to the scanning line interval.

In FIG. 3, (18) is an antenna, (19) is a tuner, (20) is an intermediate frequency amplifier, and (21) is a video detection circuit. The video signal Sv obtained by 1η from the video detection circuit (21) is sent to the luminance signal/chrominance signal separation circuit (22).
supplied to The luminance signal Y obtained from this separation circuit (22) is supplied to the signal processing circuit (24) via a delay line (23) having a delay amount of one horizontal period (ill>). (22) is supplied to the color demodulation circuit (26) via the delay line (25) having the delay amount of the color signal Cbaill.
), for example, a red difference signal R-Y and a blue difference signal B-Y.
are obtained and supplied to the signal processing circuit (24), respectively. From this signal processing circuit (24), the first red, green and blue j
The Kyoto color signals R1, G+ and B1 are output, and the respective amplifiers (
2"7R1), (27at) and (27B1) to the first cup FK1 of the cathode ray tube (IR), (IG) and (IB). Also, from the signal processing circuit (24) , second red, green and blue primary color signals R2, G2 and B2
are output and supplied to the second cathodes of the cathode ray tubes (IR), (IG) and (IB) via amplifiers (27R2), (27G2) and (2782), respectively. In this example, the second primary color signals R2, G2 and B2 are the same signals as the first primary color signals R1, G1 and B1, respectively.

In addition, in FIG. 3, the video signal Sv leaked from the video detection circuit (21) is supplied to the synchronization separation circuit (2B). This separation episode b! 8 (28), one vertical synchronization signal Vs+sync and horizontal synchronization signal Hsync are obtained from vertical deflection times 11 (29ν) and horizontal deflection times 1(29ν).
11). And these deflection circuits (29V
) and (29H), the deflection signals Svo and SHD are supplied to the deflection coils (30) of the cathode ray tubes (IR), (IG), and (IB), respectively.

In addition, the synchronization signal V 5y obtained from the separation circuit (28)
nc and H3ync are supplied to the convergence circuit 1 (31). In this convergence circuit (31), for example, as described above, the horizontal convergence yoke (
The DC current SDR and correction signal SCH supplied to the coil (4C) of 4) are formed, and the DC current Sov and correction signal SCV supplied to the coil (5e) of the vertical convergence yoke (5) are formed. .

Different ones are formed corresponding to each of the cathode ray tubes (IR), (IG) and (IB). DC current SD
I and the correction signal Scs are supplied to a coil (4c) constituting, for example, a convergence yoke (4) of the cathode ray tubes (IR), (IG), and (IB). Also, the direct current So
v and Scv are connected to the coil (5e) constituting, for example, the Jimbarsens yoke (5) of the cathode ray tube (IR), (IG), and (IB) via adders (32R), (32G), and (32B), respectively. ).

In addition, in FIG. 3, the luminance signal from the separation circuit (22) and the luminance signal passed through the delay line (23) are supplied to a subtracter (33), and the subtracted output is output from the absolute value circuit (34).
) is supplied to the maximum value selection circuit (35). In this case, a correlation detection circuit is configured by the delay line (23), the subtracter (33), and the absolute value circuit (34), and the correlation between the current video signal and the video signal after one horizontal period is detected, and the non-correlation is detected. The stronger the signal, the larger the signal obtained as the output SCB of the absolute value circuit (34).

Further, the luminance signal passed through the delay line (23) and the signal further passed through the delay line (36) having a delay amount of ill are supplied to a subtracter (37), and the subtracted output is sent to the absolute value circuit. The maximum weight 1 is supplied to the selection circuit (35) via (38). In this case, the delay line (36), the reduction 'W, the device (
37) and the absolute value circuit (3B) constitute a correlation detection circuit, which detects the correlation between the current video signal and the video signal one horizontal period ago, and the stronger the non-correlation, the higher the output S of the absolute value circuit (38).
A large signal can be obtained as a CP.

The selection circuit (35) selects the larger output SCB or SCF, and the selected signal is supplied to the comparison amplifier (39). A reference signal 5REF is supplied to this comparison amplifier (39). This reference signal 5RE
For example, the level of P is such that the vehicle surface decorrelation is equal to or higher than a predetermined value,
The outputs SeB and S of the absolute value circuits (34) and (38) when the above-mentioned deterioration of vertical resolution cannot be overlooked.
The base level is adjusted to a level smaller than the level of ep.

A selection circuit (35) is connected to the output side of this comparison amplifier (39).
) output (the larger signal of SCB and SCF) becomes larger than the base signal ((to signal 5REP), S CM AX
Thus, a signal SC which is the opposite of this and becomes 0 is obtained. S
In CMAX, when this is supplied to the coil (5e) of the vertical convergence yoke (5), the first and second electron beams Bmz and 8m2 are separated by an interval equal to the scanning line interval in the vertical direction on the fluorescent surface. It is set to a value that changes the state from the state that was specified to the state that matches the state. The output signal SG of this comparison amplifier (39) is output from the adder (32R), (32G > and (
32B). And adder (32R) (
32G) and (32B), the direct current Snv from the convergence circuit (31) and the correction signal Sc
The signal So of each is added to v. The respective sum signals are applied to the coils (5e) constituting the vertical convergence yokes (5) of the cathode ray tubes (IR), (IG) and (IB).
supplied to

This example is configured as described above, and when the non-correlation value between the current video signal and the video signal before or after one horizontal period is less than a predetermined value, the output signal JF+So of the comparison amplifier (39) becomes 0, and the fluorescence First and second electron beams Bn+ on the surface
and 8 m2, and are left vertically spaced apart by a distance of 8 m2, resulting in non-interlaced display. Furthermore, when the non-correlation value between the current video signal and the video signal before or after one horizontal period is greater than or equal to a predetermined value, the output signal SC of the comparison amplifier (39) becomes 5CIIΔ×, and the first and second electron beam Bm1 and 8m
2 are made to match, so interlaced display is performed.

According to this example, if the vertical correlation is weak and non-interlaced display would result in a significant decrease in vertical resolution, interlane display is performed, so the areas with weak vertical correlation are Deterioration in vertical resolution can be prevented.

Here, when the scanning lines of the first field and the second field in the interlaced system are as shown in FIGS. 1A and B, the first and second electron beams Bm1.8m2 are The scanning lines of the first field and the second field are as shown in FIGS. 15A and 15B, respectively. The luminance of the composite of these two fields is C in the same figure.
It becomes as shown in . Here, solid lines and broken lines indicate the luminance of the scanning lines of the first field and the second field, respectively. In this case, rising to own level,
The fall from the self level is performed at one more scanning line interval, and the problem of the conventional method (see FIG. 2C) (inferior vertical resolution compared to the conventional method) is prevented.

Note that in cases where the correlation between the current video signal and the video signals before and after one horizontal period is not detected, as in the example in FIG. Vertical resolution deterioration is not well prevented at either of the falling edges. For example, in the case where only the correlation with the video signal of one horizontal period before is detected, the scanning lines of the first field and the second field are as shown in FIGS. 16A and 16B. Then, the luminance obtained by combining these two fields becomes as shown in FIG. In this case, the rise to the own level takes more than 10 scanning line intervals,
It can be seen that the vertical resolution is degraded.

In addition, in this example in FIG. 3, the second primary color signal R2,
Although G2 and B2 are the same signals as the first primary color signals R1, Gl, and B1, the second primary color signals R2, C10, and B2 are the same as the first primary color signals R1, Gl, and B1, respectively.
The same configuration can be applied to a signal obtained by averaging two scanning line segments of 1, Gl, and B1.

Next, FIG. 17 shows another embodiment of the present invention.

In FIG. 17, parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In the figure, a luminance signal passed through a delay line (23) is supplied to a signal processing circuit (40). This signal processing circuit (
40), the first and second luminance signals Y1 and Y2 are obtained. In this case, the second luminance signal Y2 may be the same signal as the first luminance signal Y1, or the second luminance signal Y2 may be the same signal as the first luminance signal Y1.
] may be a signal obtained by averaging two scanning line segments.

The first and second brightness new scents Y1 and Y2 are outputted by adders (41Ri), (41R2), (41G1) and (
41G2), (41p+t) and (4182).

Further, the color signal passed through the delay line (25) is transmitted to the color demodulation circuit (
42). And this color demodulation circuit (42)
A red difference signal R-y, a green difference signal G-Y, and a blue difference signal B-Y are obtained. The red difference signal R-Y is sent to the adder (4
1R1) and (41R2). First and second red primary color signals R1 and R2 are obtained from these adders (41R1) and (41R2), respectively, and are passed through amplifiers (27R1) and (27R2) to the cathode ray tube (
1 and 2 to the first and second cathodes of the IR). Further, the green difference signal G-Y is supplied to adders (41G1) and (41G2). And these adders (
The first and second green primary color signals G1 and G2 are obtained from the amplifiers (41G1) and (41a*), respectively.
Cathode ray tube (IG) via (7Gt) and (27G2)
is supplied to the first and second cathodes Kt and 2.

Further, the blue difference signal 113-Y is supplied to adders (41B1) and (41B2). And these adders (4
1pt) and (41B2), the first and second
Blue primary color signals B1 and B2 are obtained, and the amplifier (27
Bi) and (27B2) are supplied to the first and second cathodes K] and 2 of the cathode ray tube (IB).

The rest of the structure is the same as the example shown in FIG.

Also in the example of FIG. 17, if the vertical decorrelation is equal to or greater than a predetermined value, the first and second electron pulses 1T11 and 8m2 are made to coincide on the fluorescent surface, so the third The same effects as in the illustrated example can be obtained.

In the above embodiment, non-interlaced display,
Although the interlace display is not digitally controlled, for example, a limiter amplifier is used in place of the comparison amplifier (39), and when the decorrelation value is greater than a predetermined value, the first and second electron beams Bmz and 8+112 are The first and second electron beams Bi1 and 8m2 may be made to coincide with each other on the fluorescent surface, and when the electron beams Bi1 and 8m2 are brought closer to each other in an analog manner. With this configuration, even if the brightness changes exponentially in the vertical direction, for example, there will be no difference in level between non-interlaced display and interlaced display, which will not deteriorate the image quality.

In addition, in the above embodiment, 1i1f is a non-interlaced display, and when the vertical non-correlation is greater than a predetermined value, an interlaced display is used, but on the other hand, normally an interlaced display is used, and the vertical correlation is Similar effects can be obtained by configuring the display to be non-interlaced when the value exceeds a predetermined value.

Effects of the Invention According to the present invention described above, when the vertical decorrelation exceeds a predetermined value, the first and second electron beams are made to coincide on the fluorescent surface, so that non-interlaced scanning can be performed. It is possible to prevent the vertical resolution from deteriorating in the superposition decorrelation part due to this.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining the conventional example, respectively.
The figure is a block diagram showing one embodiment of the present invention, Figures 4 to 16 are diagrams for explaining the example in Figure 3, respectively, and Figure 17 is a block diagram showing another embodiment of the present invention. . (IR), (IG) and (IB) are cathode ray tubes, (2
3) and (36) are delay lines respectively, (31) is a convergence circuit, (32R), (32G) and (32B) are adders respectively, (33) and (37) are subtracters respectively, (3)
4) and (38) are absolute value circuits, (35) is a maximum value selection circuit, and (39) is a comparison amplifier. Fig. 11 B Fig. 21 B Z□ 1□ Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 2□

Claims (1)

[Claims] An interlaced video signal is supplied to first and second electron beam generation sources, and non-interlaced scanning is performed on the fluorescent surface by the first and second electron beams, in which the current video signal and one horizontal a first detection circuit that detects a correlation between a video signal before a period, a current video signal and a first detection circuit;
and a second detection circuit for detecting the correlation of the video signal after the horizontal period, and when the first or second detection circuit detects a non-correlation of a predetermined value or more, the first and second detection circuits A television receiver characterized in that an electron beam of the phosphor is made to coincide with the phosphorescent surface.