JPH1173152A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture display device of a field sequential system and capable of suppressing a density modulation and brightness modulation, which may occur when a white cathode-ray tube is used. SOLUTION: This picture display device has a white cathode-ray tube 1 scanning plural electron beams and displaying white picture so that the scanning lines are arranged at regular intervals in the direction perpendicular to the scanning lines on the picture display screen, and a vertical position setting part 2 for setting the vertical direction of the raster, and periodically changes the position of one or plural scanning line intervals and the raster position in the vertical direction so that a value, which is obtained by integrating brightness of each scanning line within a range of one or plural frames by the vertical position setting part 2, becomes uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device provided with a white cathode ray tube for displaying a white image by scanning a plurality of electron beams vertically arranged at regular intervals on an image display surface, and more particularly to each scanning device. The present invention relates to a scanning method for making the luminance of a line uniform.

[0002]

2. Description of the Related Art A white image displayed on a white cathode ray tube (CRT) is red (R), green (G),
An image display device that displays a color image by coloring in the order of blue (B) is disclosed in, for example, JP-A-6-161383. In this white cathode ray tube,
Since the field sequential scanning is performed at 3 × speed, the luminance becomes 1
/ 3.

[0003] For this reason, a field-sequential type parallel scanning white CRT has been proposed, in which three electron beams are simultaneously emitted from an electron gun portion and the three electron beams are simultaneously scanned while maintaining the same distance vertically. ing.

[0004]

However, when three electron beams are scanned, each electron beam is caused by a difference in the trajectory of the electron beam or a difference in the just focus voltage between the center beam and the side beam. Difference in beam profile (that is, difference in intensity distribution of each electron beam)
Due to this, density modulation and luminance modulation of scanning lines occur, horizontal stripes appear when displaying solid white signals, color bars, etc., and the problem that the thickness becomes inconsistent when displaying vertical lines, etc. Occurs.

Accordingly, an object of the present invention is to provide an image display apparatus capable of suppressing density modulation and luminance modulation which may occur when a white cathode ray tube of a field sequential system and a parallel scanning system is used. It is in.

[0006]

According to a first aspect of the present invention, there is provided an image display apparatus for displaying a white image by scanning a plurality of electron beams on an image display surface so as to be arranged at regular intervals in a direction perpendicular to a scanning line. An apparatus having a cathode ray tube, comprising vertical position setting means for setting a vertical position of a raster, wherein the vertical position setting means integrates the luminance of each scanning line in a range of one or a plurality of frames. Periodically, 1 to be uniform
Alternatively, it is characterized in that a plurality of scanning line intervals and a raster position are changed in the vertical direction.

According to a second aspect of the present invention, in the image display device according to the first aspect, the vertical position setting means overlaps the vertical deflection waveform with a vertical deflection waveform generating means for generating a constant vertical deflection waveform. A superimposed waveform generating means for generating a plurality of waveforms, an adding means for superimposing one of the waveforms generated by the superposed waveform generating means on the vertical deflection waveform, and the adding means from among the waveforms generated by the superposed waveform generating means. A switching means for periodically switching a waveform to be added to the vertical deflection waveform, and a vertical deflection coil for setting a vertical position of a raster based on an output of the adding means.

According to a third aspect of the present invention, in the image display apparatus according to the first aspect, the vertical position setting means generates a plurality of vertical deflection waveforms for generating different vertical deflection waveforms, and the plurality of vertical deflection waveforms. Selecting means for periodically selecting one of the vertical deflection waveforms generated by the generating means, and a vertical deflection coil for setting the vertical position of the raster based on the vertical deflection waveform selected by the selecting means. It is characterized by having.

According to a fourth aspect of the present invention, in the image display device according to any one of the first to third aspects, the plurality of electron beams include first to third electron beams, and (3h +
The (1) th (h = 0, 1, 2,...) Scanning line is scanned with the first electron beam, the (3h + 2) th scanning line is scanned with the second electron beam, and the (3h + 3) th scanning line is scanned. The line is scanned by the third electron beam, and the scanning lines by the first, second, and third electron beams in the (N + 1) th frame are scanned by the second, third, and first electron beams in the Nth frame, respectively. The vertical position setting means sets the raster position so as to be scanned at the position of the line, and the scanning lines by the first, second, and third electron beams in the (N + 2) th frame are respectively set in the Nth frame. The vertical position setting means sets the raster position so that scanning is performed at the position of the scanning line by the third, first, and second electron beams, and the first, second, and third electrons in the (N + 3) th frame are set. Each scanning line by the beam First in the frame, the second, third
To be scanned at the position of the scanning line by the electron beam of
The vertical position setting means sets a raster position, and repeats the processing from the (N + 1) th frame to the (N + 3) th frame in a cyclic manner.

According to a fifth aspect of the present invention, in the image display device according to any one of the first to third aspects, the plurality of electron beams include first to third electron beams, and (3h +
The (1) th (h = 0, 1, 2,...) Scanning line is scanned with the first electron beam, the (3h + 2) th scanning line is scanned with the second electron beam, and the (3h + 3) th scanning line is scanned. The line is scanned by the third electron beam, and the scanning lines by the first, second, and third electron beams in the (N + 1) th frame are respectively scanned by the third, first, and second electron beams in the Nth frame. The vertical position setting means sets the raster position so as to be scanned at the position of the line, and the scanning lines by the first, second, and third electron beams in the (N + 2) th frame are respectively set to the second line in the Nth frame. The vertical position setting means sets a raster position so that scanning is performed at scanning line positions by the third, first and third electron beams, and the first, second, and third electron beams in the (N + 3) th frame are scanned. Each scanning line by the beam First in the frame, the second, third
To be scanned at the position of the scanning line by the electron beam of
The vertical position setting means sets a raster position, and repeats the processing from the (N + 1) th frame to the (N + 3) th frame in a cyclic manner.

According to a sixth aspect of the present invention, in the image display device according to the first aspect, the plurality of electron beams include first to third electron beams, and (3h +
The (1) th (h = 0, 1, 2,...) Scanning line is scanned with the first electron beam, the (3h + 2) th scanning line is scanned with the second electron beam, and the (3h + 3) th scanning line is scanned. The line is scanned by the third electron beam, and the scanning lines by the first, second, and third electron beams in the (M + 1) th field are respectively scanned by the second, third, and first electron beams in the Mth field. The vertical position setting means sets the raster position so as to be scanned at the position of the line, and the scanning lines by the first, second, and third electron beams in the (M + 2) th field are respectively set in the Mth field. Third, the vertical position setting means sets the raster position so that scanning is performed at the positions of the scanning lines by the first and second electron beams, and the first, second, and third electrons in the (M + 3) field are set. The scanning line by the beam The vertical position setting means sets a raster position so that scanning is performed at positions of scanning lines by the first, second, and third electron beams in the M-th field, respectively. (M + 3)
It is characterized in that the processing up to the field is repeated in a cyclic manner.

According to a seventh aspect of the present invention, in the image display device according to any one of the first to third aspects, the plurality of electron beams include first to third electron beams, and (3h +
The (1) th (h = 0, 1, 2,...) Scanning line is scanned with the first electron beam, the (3h + 2) th scanning line is scanned with the second electron beam, and the (3h + 3) th scanning line is scanned. The line is scanned by the third electron beam, and the scanning lines by the first, second, and third electron beams in the (M + 1) th field are respectively scanned by the third, first, and second electron beams in the Mth field. The vertical position setting means sets the raster position so as to be scanned at the position of the line, and the scanning lines by the first, second, and third electron beams in the (M + 2) th field are respectively set to the second position in the Mth field. The vertical position setting means sets the raster position so that scanning is performed at the position of the scanning line by the third, first and third electron beams, and the first, second, and third electrons in the (M + 3) field are set. The scanning line by the beam The vertical position setting means sets a raster position so that scanning is performed at positions of scanning lines by the first, second, and third electron beams in the M-th field, respectively. (M + 3)
It is characterized in that the processing up to the field is repeated in a cyclic manner.

According to an eighth aspect of the present invention, in the image display device according to any one of the first to third aspects, the plurality of electron beams include first to third electron beams, and each frame includes three fields. The raster positions in each field include a first position, a second position one scan line interval below the first position, and a third position one scan line interval above the first position. Yes, the raster position is switched between the first position, the second position, and the third position in three fields in each frame, and in each of the first to third fields of three consecutive frames. The vertical position setting means changes the raster position for each field so that the position of the raster is switched to the first position, the second position, and the third position.

According to a ninth aspect of the present invention, there is provided the image display device according to any one of the first to eighth aspects, further comprising coloring means for coloring a white image in front of the image display surface of the cathode ray tube. I have.

According to a tenth aspect of the present invention, there is provided the image display device according to any one of the sixth and seventh aspects, wherein a white image is colored in first to third colors in front of the image display surface of the cathode ray tube. Means (M + 3i) -th field (i =
0, 1, 2,...) Are colored in a first color, and the (M +
The image of the (3i + 1) field is colored in a second color, and the image of the (M + 3i + 2) field is colored in a third color.

According to an eleventh aspect of the present invention, in the image display device according to the sixth or seventh aspect, a coloring means for coloring an image in first to third colors in front of the image display surface of the cathode ray tube. And the (M + 9i) th field (i = 0,
The images of (1, 2,...) Are colored in the first color, and the (M + 9i)
+1) The image of the field is colored in the second color, and the (M +
The image in the (9i + 2) field is colored in the third color, the image in the (M + 9i + 3) field is colored in the second color, the image in the (M + 9i + 4) field is colored in the third color, and the (M + 9i + 5) The image of the field is colored in the first color, the image of the (M + 9i + 6) field is colored in the third color, the image of the (M + 9i + 7) field is colored in the first color, and the image of the (M + 9i + 8) field is colored. It is characterized in that the image is colored in a second color.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a configuration diagram showing an image display device according to Embodiment 1 of the present invention. Embodiment 1 As shown in FIG.
Is a white cathode ray tube (CRT) 1 that displays a white image by scanning a plurality of electron beams so as to be arranged at regular intervals in a direction (Y direction) perpendicular to a scanning line on an image display surface.
And a vertical position setting unit 2 for setting a vertical position of the raster on the CRT 1. Vertical position setting unit 2
Changes the position of the raster in the vertical direction periodically at intervals of one or more scanning lines so that the value obtained by integrating the brightness of each scanning line within one or more frames is uniform.

The vertical position setting unit 2 includes a vertical deflection waveform generator 3 for generating a constant vertical deflection waveform VD ₁ in synchronization with the vertical synchronization signal VS, and a plurality of waveforms VD ₂ , which are superimposed on the vertical deflection waveform VD ₁ . A superimposed waveform generator ₄ for generating VD ₃ and VD ₄ . Further, the vertical position setting unit 2 applies the waveforms VD ₂ and VD from the superimposed waveform generation unit 4 to the vertical deflection waveform VD _1.
3 and VD ₄ , and a toggle switch for periodically switching the waveform input to the adder 5 from the waveforms VD ₂ , VD ₃ and VD ₄ generated by the superimposed waveform generator 4. 6, an amplification amplifier 7 for amplifying the vertical deflection waveform VD output from the adder 5, and a vertical deflection coil 8 for setting the vertical position of the raster based on the amplified vertical deflection waveform VD.

The waveform generator 4, a first waveform generator 10 for outputting a waveform VD _2, a second waveform generator 11 for outputting a waveform VD _4, grounding unit for outputting a waveform VD ₃ (GN
D) 12.

FIG. 2 is a longitudinal sectional view schematically showing a main structure of the CRT 1 of FIG. As shown in FIG.
RT1 is an image in which an electron gun unit 20 that emits three electron beams 21, 22, and 23, and a fluorescent substance is provided for the three electron beams 21, 22, and 23 emitted from the electron gun unit 20. A beam control unit 25 for generating magnetic fields arranged at equal intervals in the vertical direction (Y direction) on the display surface 1a, and a coloring unit 26 such as a liquid crystal shutter for coloring a white image displayed on the image display surface 1a. Have.

FIGS. 3 and 4 are explanatory diagrams showing an example of the magnetic field formed by the beam control unit 25. FIG. As shown in FIG. 3, from the electron gun unit 20,
The electron beams 21, 22, and 23 are emitted. When these electron beams 21, 22, 23 pass through a magnetic field 27 as shown in FIG. 3, inward forces 28, 29 act on the outer electron beams 21, 23, respectively. When these electron beams 21, 22, and 23 pass through a magnetic field 30 as shown in FIG.
An upward and downward force 31, 32 acts on each of the three. Accordingly, by the combination of the magnetic field 27 of FIG. 3 and the magnetic field 30 of FIG.
1, 2, 23 can be arranged in the vertical direction. However, the method of arranging the electron beams in the vertical direction is not limited to the above method.

FIG. 5 is an explanatory diagram showing parallel scanning of three electron beams 21, 22, 23 when the image display surface 24 of the CRT 1 is viewed from the front. As shown in FIG.
Three each electron beams 21, 22 of the first, second, third scanning lines L _1, L _2, scans L ₃ simultaneously, then the fourth, fifth, sixth scan Line L ₄ ,
L ₅ and L ₆ are simultaneously scanned, and the subsequent scanning lines are also simultaneously scanned three by three.

FIG. 6 is an explanatory diagram showing an example of processing for changing the raster position by the vertical position setting unit 2.

FIG. 6A shows that the toggle switch 6 selects the ground portion 12, the ground potential waveform VD ₃ and the sawtooth vertical deflection waveform VD ₁ are input to the adder 5, and are input to the amplifier 7. Vertical deflection waveform VD is VD ₁ + VD ₃ = VD
Indicates when it is ₁ . In this case (when the waveform is not superimposed on the vertical deflection waveform VD ₁ ), the position of the raster 40 with respect to the image display surface is at the reference position as shown in FIG.

FIG. 6B shows that the toggle switch 6 selects the waveform generator 10 and the adder 5 supplies a + V DC voltage waveform VD.
₂ and the sawtooth vertical deflection waveform VD ₁ are input, and the vertical deflection waveform VD input to the amplification amplifier 7 is VD ₁ + V
Shows the case where D _2. In this case, the position of the raster with respect to the image display surface moves upward by one scanning line interval D from the reference position in FIG.

FIG. 6C shows that the toggle switch 6 selects the waveform generator 11 and the adder 5 supplies the -V DC voltage waveform VD.
₄ and the sawtooth vertical deflection waveform VD ₁ are input, and the vertical deflection waveform VD input to the amplification amplifier 7 is VD ₁ + V
Shows the case where D _4. In this case, the position of the raster 40 with respect to the image display surface is shifted by one scanning line interval D from the reference position in FIG.

However, FIG. 6 is based on the assumption that the deflection sensitivity of the entire screen is the same and the vertical linearity is constant, so that the actual waveforms VD ₂ and VD ₄ are the DC voltage as shown in the figure. Sometimes it does not.

FIG. 7 is an explanatory diagram showing only three of the scanning lines constituting the raster moved by the vertical position setting unit 2. FIG. 7A corresponds to FIG. 6A, and FIG.
Corresponds to FIG. 6 (B), and FIG. 7 (C) corresponds to FIG. 6 (C). In FIG. 7, a is the electron beam 2
1, b indicates a scanning line by the electron beam 22, and c indicates a scanning line by the electron beam 23.

FIG. 8 shows an example of the beam profile of the electron beams 21, 22, and 23. The horizontal axis corresponds to the line S ₁ -S _{1 in} FIG. 5, and the vertical axis shows the intensity of the electron beam. .
The beam profile of the electron beam is preferably a normal distribution (Gaussian distribution) as shown in FIG. 8A, but each of the electron beams 21, 22, and 23 has a unique beam profile due to various factors. . For example, FIG.
As shown in FIG. 8B, the half width HW is widened, the balance is lost as shown in FIG. 8C, or the rising characteristic is poor as shown in FIG.

FIG. 9 shows, for example, by changing the raster position as shown in FIG.
That is, it is an explanatory diagram for explaining that the integrated value of the luminance of the scanning line becomes uniform. Here, FIG.
FIG. 9B corresponds to FIG. 7B, and FIG. 9C corresponds to FIG. 7C. Also, FIG.
This shows a case where the beam profiles of the electron beams a and c have a substantially Gaussian distribution, and the beam profile of the electron beam b has a distribution with a wide half-value width.

When the raster position is periodically changed as shown in FIGS. 7 and 9, the integral value of the beam profile of the electron beam scanning the same position on the screen is as shown in FIG.
This corresponds to the sum of the beam intensities of the electron beams shown in (A), (B), and (C). When the raster position is periodically changed in this manner, the integral value of the beam profile is the same value for each of the scanning lines 41, 42, 43, and 44 (the value obtained by adding the beam intensities of the electron beams 21, 22, and 23). ). That is, when focusing on a scanning line at a certain position on the image display surface 1a, the electron gun that draws the scanning line is switched every vertical cycle. Therefore, the difference in the integral value of the beam profile in each scanning line is not recognized by the viewer, and the density modulation and the luminance modulation of the scanning line can be reduced.

In the above description, the case where three electron beams are scanned in parallel has been described. However, the present invention is not limited to this. Two electron beams or four or more electron beams are used. The present invention can also be applied to the case where are scanned in parallel.

Second Embodiment FIG. 10 is a configuration diagram showing an image display device according to a second embodiment of the present invention. 10, the same reference numerals are given to the same or corresponding components as those in FIG. The image display device according to the second embodiment differs from the vertical position setting unit 2 according to the first embodiment only in the configuration of the vertical position setting unit 50.

[0035] As shown in FIG. 10, the vertical position setting unit 50, different vertical deflection waveform VD _11, VD _12, VD ₁₃ a plurality of vertical deflection waveform generator 51, 52 and 53 for generating a
And a selection switch 54 for periodically selecting one of the vertical deflection waveforms VD ₁₁ , VD ₁₂ and VD ₁₃ generated by the plurality of vertical deflection waveform generators 51, 52 and 53. Also,
The vertical position setting unit 50 sets the vertical position of the raster based on the amplifier 7 for amplifying the vertical deflection waveform VD selected by the selection switch 54 and the vertical deflection waveform VD amplified by the amplifier 7. And a vertical deflection coil 8.

In the second embodiment as well, the raster position can be switched as shown in FIG. 7, and for the same reason as in the first embodiment, luminance modulation and density modulation can be suppressed. In the second embodiment, the other points are the same as those in the first embodiment.

Third Embodiment FIG. 11 is a configuration diagram showing an image display device according to a third embodiment of the present invention. 11, the same or corresponding components as those in FIG. 1 are denoted by the same reference numerals. The image display device according to the third embodiment includes a frequency divider 55 for setting the frequency of the vertical synchronization signal VS to １ ／, and sets the toggle switch 6 to the vertical period signal V.
Switching in a cyclic manner at a frequency of 1/3 of S, and
The point that it has a coloring section 26 composed of a color filter or the like for coloring a white image into one of three colors of R, G, and B, and a color selection circuit 57 that switches the coloring section 26 in synchronization with the vertical synchronization signal VS. This is different from the image display device of the first embodiment.

FIG. 12 is an explanatory diagram showing the operation of the image display device according to the third embodiment. FIG. 12 shows that each of the Nth frame, the (N + 1) th frame, and the (N + 2) th frame is composed of three fields, the white image displayed in each field is colored R, G, B, Array of scanning lines a, b, c for displaying fields, and
This shows the position of the raster.

In FIG. 12, a is the first electron beam 2
1 shows the (3h + 1) -th (h = 0, 1, 2,...) Scan line, and b denotes (3h +
2) shows the 2nd scan line, and c shows the (3h + 3) th scan line by the third electron beam 23.

As shown in FIG. 12, the scanning lines a, b, and c by the first, second, and third electron beams in the (N + 1) th frame are respectively the second, and the third lines in the Nth frame.
The vertical position setting unit 2 controls the raster 4 so that the scanning is performed at the positions of the scanning lines b, c, a by the third and first electron beams.
The position of 0 is shifted by one scanning line interval D from the reference position. Also, the first in the (N + 2) th frame,
The scanning lines a, b, and c by the second and third electron beams are respectively scanned at the positions of the scanning lines c, a, and b by the third, first, and second electron beams in the N-th frame.
The vertical position setting unit 2 sets the position of the raster 40 as 1 from the reference position.
It is moved upward by the scanning line interval D. In addition, the (N +
3) The scanning lines a, b, and c by the first, second, and third electron beams in the frame are the scanning lines a, b, and c by the first, second, and third electron beams in the N-th frame, respectively.
The vertical position setting unit 2 sets the position of the raster 40 to a reference position indicated by a broken line so that scanning is performed at the position of. In the third embodiment, the processes from the (N + 1) th frame to the (N + 3) th frame are repeated in a cyclic manner.

In the third embodiment as well, the raster position is switched for each frame as in FIG. 7, so that the luminance modulation and density modulation can be suppressed for the same reason as in the first embodiment.

In the above description, the case where three electron beams are scanned in parallel has been described. However, the present invention is not limited to this. Two electron beams or four or more electron beams are used. The present invention can also be applied to the case where are scanned in parallel.

In the above description, the (N +
1) The case where the raster is moved downward by one scanning line interval in the frame and the raster is moved upward by one scanning line interval in the (N + 2) th frame has been described.
1) In the frame, the raster may be moved upward by one scanning line interval, and in the (N + 2) th frame, the raster may be moved downward by one scanning line interval.

The other points of the third embodiment are the same as those of the first embodiment.

Fourth Embodiment FIG. 13 is a configuration diagram showing an image display device according to a fourth embodiment of the present invention. In FIG. 13, the same or corresponding components as those in FIG. 1 are denoted by the same reference numerals. The image display device according to the fourth embodiment includes a coloring unit 26 including a color filter or the like for coloring a white image into one of three colors of R, G, and B, and a coloring unit 2.
6 is different from the image display device of the first embodiment in that a color selection circuit 57 for switching a color to be colored by the sixth in synchronization with the vertical synchronization signal VS is provided.

FIG. 14 is an explanatory diagram showing the operation of the image display device according to the fourth embodiment. FIG. 14 shows that each of the N-th frame, the (N + 1) -th frame, and the (N + 2) -th frame consists of three fields, the white image displayed in each field is colored R, G, and B. Array of scanning lines a, b, c for displaying fields, and
The position of the raster 40 is shown.

In FIG. 14, a is the first electron beam 2
1 shows the (3h + 1) -th (h = 0, 1, 2,...) Scan line, and b denotes (3h +
2) shows the 2nd scan line, and c shows the (3h + 3) th scan line by the third electron beam 23.

As shown in FIG. 14, the scanning lines a, b, and c by the first, second, and third electron beams in the (M + 1) th field are the second, third, and first lines in the Mth field, respectively. The vertical position setting unit 2 moves the position of the raster 40 below the reference position by one scanning line interval D so that the scanning lines b, c, and a are scanned by the electron beam. Also, scanning lines a, b, and c by the first, second, and third electron beams in the (M + 2) -th field
The vertical position setting unit 2 scans the position of the raster 40 from the reference position by one scan so that the scanning is performed at the positions of the scanning lines c, a, and b by the third, first, and second electron beams in the Mth field, respectively. It is moved upward by the line interval D. Note that the scanning lines a, b, and c of the first, second, and third electron beams in the (M + 3) field are respectively the scanning lines a, b of the first, second, and third electron beams in the M-th field. , C, the vertical position setting unit 2 sets the position of the raster 40 to a reference position indicated by a broken line. In the fourth embodiment, the (M +
1) The processing from the field to the (M + 3) th field is repeated in a cyclic format.

In the fourth embodiment as well, the raster position is switched for each field as in FIG. 7, so that the luminance modulation and the density modulation can be suppressed for the same reason as in the first embodiment.

In the above description, the case where three electron beams are scanned in parallel has been described. However, the present invention is not limited to this. Two electron beams or four or more electron beams are used. The present invention can also be applied to the case where are scanned in parallel.

In the above description, the (M +
In the case where the raster is moved downward by one scanning line interval in the 1) field and the raster is moved upward by one scanning line interval in the (M + 2) th field, the raster is shifted by 1 in the (M + 1) th field. The raster may be moved upward by one scanning line interval in the (M + 2) -th field by moving the raster line upward.

The other points of the third embodiment are the same as those of the first embodiment.

Embodiment 5 FIG. 15 is a configuration diagram showing an image display device according to Embodiment 5 of the present invention. In FIG. 15, the same or corresponding components as those in FIG. 1 are denoted by the same reference numerals. The image display device according to the fifth embodiment includes a frequency divider 55 that outputs a signal having a frequency that is 1/3 of the vertical synchronization signal VS.
Is switched in a cyclic manner at a cycle of 1/3 of the vertical synchronizing signal VS, a toggle switch 59 for changing the output of the waveform generator 4 inputted to the toggle switch 6 at a cycle of the vertical synchronizing signal VS, The image display of the first embodiment is characterized in that the image display of the first embodiment has a coloring section 26 for coloring any one of the three colors of R, G, and B, and a color selection circuit 57 for switching the coloring section 26 in synchronization with the vertical synchronization signal VS. It is different from the device.

FIG. 16 is an explanatory diagram showing the operation of the image display device according to the fifth embodiment. FIG. 16 shows that each of the Nth frame, the (N + 1) th frame, and the (N + 2) th frame is composed of three fields, the white image displayed in each field is colored R, G, and B. Array of scanning lines a, b, c for displaying fields, and
The position of the raster 40 is shown.

In FIG. 16, a is the first electron beam 2
1 shows the (3h + 1) -th (h = 0, 1, 2,...) Scan line, and b denotes (3h +
2) shows the 2nd scan line, and c shows the (3h + 3) th scan line by the third electron beam.

As shown in FIG. 16, in the first field of the N-th frame, the vertical, horizontal and vertical scanning lines a, b, and c are set by the vertical position setting unit 2 at the reference position ( In FIG. 16, scanning is performed at the positions indicated by two broken lines), and the first and second fields in the second field of the N-th frame are scanned.
The scanning lines a, b, and c by the second and third electron beams are scanned at the positions of the scanning lines b, c, and a by the second electron beam in the first field of the N-th frame, respectively. As described above, the vertical position setting unit 2 moves the raster position downward by one scanning line interval D from the reference position, and sets the scanning lines a by the first, second, and third electron beams in the third field of the Nth frame. , B, and c, respectively, are scanned at the positions of the scanning lines c, a, and b by the third, first, and second electron beams in the first field of the N-th frame. Is moved one scanning line interval D above the reference position.

As shown in FIG. 16, the (N +
1) The scanning lines a, b, and c of the first, second, and third electron beams in the first field of the frame are respectively Nth scanning lines.
The vertical position setting unit 2 moves the raster position from the reference position by one scanning line interval so that scanning is performed at the scanning lines b, c, and a by the second, third, and first electron beams in the first field of the frame. D, and the scanning lines a, b, and c by the first, second, and third electron beams in the second field of the (N + 1) th frame are respectively shifted to the third and fourth scanning lines in the first field of the Nth frame. The vertical position setting unit 2 moves the raster position up by one scanning line interval D from the reference position so that scanning is performed at the positions of the scanning lines c, a, and b by the first and second electron beams. ) The scanning lines a, b, and c by the first, second, and third electron beams in the third field of the frame are the scanning lines by the first, second, and third electron beams in the first field of the Nth frame, respectively. a, b, c As will be 査, vertical position setting portion 2 has set the raster position in the reference position.

As shown in FIG. 16, the (N +
2) The scanning lines a, b, and c by the first, second, and third electron beams in the first field of the frame are respectively Nth scanning lines.
The vertical position setting unit 2 moves the raster position from the reference position by one scanning line interval so that scanning is performed at the scanning lines c, a, and b by the third, first, and second electron beams in the first field of the frame. D, the scanning lines a, b, and c by the first, second, and third electron beams in the second field of the (N + 2) th frame are respectively the first and second scanning lines in the first field of the Nth frame. (2) The vertical position setting unit 2 sets the raster position to the reference position so that scanning is performed at the positions of the scanning lines a, b, and c by the third electron beam.
+2) The first, second, and third fields in the third field of the frame.
The scanning lines a, b, and c by the third electron beam are respectively the second, third, and first fields in the first field of the N-th frame.
The vertical position setting unit 2 moves the raster position down by one scanning line interval D from the reference position so that the scanning lines b, c, and a are scanned by the electron beam. Then, the processing from the Nth frame to the (N + 2) th frame is repeated in a cyclic manner.

Also in the fifth embodiment, since the raster position is switched for each field as in FIG. 7, luminance modulation and density modulation can be suppressed for the same reason as in the first embodiment. Further, in the fifth embodiment, even when only a red image, a green image, and a blue image are displayed, luminance modulation and density modulation can be suppressed.

In the above description, the case where three electron beams are scanned in parallel has been described. However, the present invention is not limited to this. Two electron beams or four or more electron beams are used. The present invention can also be applied to the case where are scanned in parallel.

The other points of the fifth embodiment are the same as those of the first embodiment.

Sixth Embodiment FIG. 17 is an explanatory diagram showing the operation of the image display device according to the sixth embodiment. FIG. 17 shows that each of the Nth frame, the (N + 1) th frame, and the (N + 2) th frame is composed of three fields, the white image displayed in each field is colored R, G, and B. The arrangement of scanning lines a, b, and c for displaying fields and the position of the raster 40 are shown.

In FIG. 17, a shows the (3h + 1) th (h = 0, 1, 2,...) Scanning line by the first electron beam, and b shows the (3h + 2) th scanning line by the second electron beam. And c represents (3h +
3) shows the third scan line.

The image display apparatus according to the sixth embodiment differs from the apparatus according to the fourth embodiment only in the control contents of the color selection circuit 57. Therefore, in describing Embodiment 6, FIG.
See also

In the fourth embodiment, when the three primary colors of the color filter are displayed in a single color, the three beam profiles are not integrated. However, as in the sixth embodiment, the color selection order of the coloring section 26 is changed. When three primary colors are displayed in a single color, the three beam profiles are integrated. Specifically, as shown in FIG. 17, the order of selecting the colors of the coloring unit 26 is synchronized with the vertical period, and the R, G, B, G, B,
The patterns R, B, R, G, R, G, B,... Are switched by the color selection circuit 57 in a cyclic manner.

Also in the sixth embodiment, since the raster position is switched for each field as in FIG. 7, luminance modulation and density modulation can be suppressed for the same reason as in the first embodiment. Further, in the sixth embodiment, even when a red-only image, a green-only image, or a blue-only image is displayed, luminance modulation and density modulation can be suppressed.

In the above description, the case where three electron beams are scanned in parallel has been described. However, the present invention is not limited to this. Two electron beams or four or more electron beams are used. The present invention can also be applied to the case where are scanned in parallel.

The color pattern by the coloring section 26 is as follows.
Other orders such as G, R, B, R, B, G, B, G, R.

The other points of the sixth embodiment are the same as those of the fourth embodiment.

Further, in the above embodiments,
In 5, 6, and 7, the method of moving the raster is described as being the same as that of the first embodiment, but another method such as that of the second embodiment may be used.

[0071]

As described above, according to the first aspect of the present invention, since the beam profile different for each electron beam is integrated by the integration effect of the eyes, it seems that there is no difference between the beam profiles. There is an effect that density modulation and luminance modulation of scanning lines caused by the difference can be reduced.

According to the second aspect of the present invention, the raster position is moved by superimposing the waveform of the superimposed waveform generating means for moving the raster position on the vertical deflection waveform. Since the different beam profiles are integrated by the integration effect of the eyes, it appears that there is no difference between the beam profiles, and there is an effect that the density modulation and the brightness modulation of the scanning lines caused by the difference in the beam profiles can be reduced.

According to the third aspect of the present invention, since the vertical main deflection waveform generator is constituted by three, different beam profiles for each electron beam are integrated by an eye integration effect. It is possible to reduce the density modulation and the luminance modulation of the scanning line caused by the difference in the beam profile, and to simplify the apparatus.

According to the fourth or fifth aspect of the present invention, since the raster position is switched in a cyclic manner for each frame, the beam profile is integrated at a cycle of three frames, and the scanning line caused by the difference in the beam profile is scanned. There is an effect that density modulation and luminance modulation can be reduced.

According to the sixth or seventh aspect of the present invention, since the raster position is switched in a cyclic manner for each field, the beam profile is integrated in a cycle of three fields, and the scanning line caused by the difference in the beam profile is scanned. There is an effect that density modulation and luminance modulation can be reduced. In addition, the frequency at which the three beam profiles are integrated is tripled, and there is an effect that flicker can be further reduced.

According to the eighth aspect of the present invention, since the raster position is switched in a cyclic manner for each field, the beam profile is integrated in a cycle of three fields, and the density modulation of the scanning line caused by the difference between the beam profiles. In addition, there is an effect that luminance modulation can be reduced. In addition, the frequency at which the three beam profiles are integrated is tripled, and there is an effect that flicker can be further reduced. In addition, even when a monochrome image is displayed, there is an effect that the density modulation and the luminance modulation of the scanning line can be reduced.

According to the ninth or tenth aspect of the present invention,
Since a coloring means for coloring a white image is provided in front of the image display surface of the cathode ray tube, a color image can be displayed.

According to the eleventh aspect of the present invention, since the order of coloring is changed for each frame, it is possible to reduce luminance modulation and density modulation even for a single-color image, and to reduce color flicker.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an image display device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view schematically showing a main configuration of the CRT in FIG.

FIG. 3 is an explanatory diagram illustrating an example of a magnetic field formed by a beam control unit.

FIG. 4 is an explanatory diagram illustrating an example of a magnetic field formed by a beam control unit.

FIG. 5 is a view of the image display surface of the CRT when viewed from the front.
FIG. 4 is an explanatory diagram illustrating parallel scanning of three electron beams.

FIG. 6 is an explanatory diagram illustrating an example of a process of changing a raster position by a vertical position setting unit.

FIG. 7 is an explanatory diagram showing only three scanning lines constituting a raster moved by a vertical position setting unit.

FIG. 8 is a diagram illustrating an example of a beam profile of an electron beam.

FIG. 9 is an explanatory diagram for explaining that an integral value of a beam profile, that is, an integral value of luminance of a scanning line becomes uniform for each scanning line by changing a raster position as shown in FIG. 7;

FIG. 10 is a configuration diagram illustrating an image display device according to a second embodiment of the present invention.

FIG. 11 is a configuration diagram illustrating an image display device according to a third embodiment of the present invention.

FIG. 12 is an explanatory diagram illustrating an operation of the image display device according to the third embodiment;

FIG. 13 is a configuration diagram illustrating an image display device according to a fourth embodiment of the present invention.

FIG. 14 is an explanatory diagram illustrating an operation of the image display device according to the fourth embodiment;

FIG. 15 is a configuration diagram illustrating an image display device according to a fifth embodiment of the present invention.

FIG. 16 is an explanatory diagram illustrating an operation of the image display device according to the fifth embodiment.

FIG. 17 is an explanatory diagram illustrating an operation of the image display device according to the sixth embodiment of the present invention.

[Explanation of symbols]

1 white cathode ray tube, 2 vertical position setting unit, 3 vertical polarized waveform generator, 4 superimposed waveform generator, 5 adder,
6,59 toggle switch, 7 amplifier, 8
Vertical deflection coil, 10, 11 Waveform generator, 12
Grounding section, 20 electron gun section, 21, 22, 23 electron beam, 24 image display surface, 25 beam control section,
26 colored parts, 40 rasters, 55 frequency divider,
57 color selection circuit.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 9/16 H04N 9/16 (72) Inventor Hideki Yoshii 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Shuji Iwata 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Naoki Shiramatsu 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation

Claims (11)

[Claims] 1. An image display device having a white cathode ray tube for displaying a white image by scanning a plurality of electron beams so as to be arranged at regular intervals in a direction perpendicular to a scanning line on an image display surface, wherein Vertical position setting means for setting the position of the scanning line, the vertical position setting means periodically, one or more such that the integrated value of the brightness of each scanning line in the range of one or more frames is uniform An image display device wherein a scanning line interval and a raster position are changed in a vertical direction. 2. The vertical position setting means, wherein: a vertical deflection waveform generating means for generating a constant vertical deflection waveform; a superimposed waveform generating means for generating a plurality of waveforms to be superimposed on the vertical deflection waveform; Adding means for superimposing one of the waveforms generated by the superimposed waveform generating means on the other, and periodically switching a waveform added to the vertical deflection waveform by the adding means from among the waveforms generated by the superimposed waveform generating means 2. The image display device according to claim 1, further comprising: a switching unit; and a vertical deflection coil for setting a vertical position of the raster based on an output of the adding unit. 3. The vertical position setting means comprises: a plurality of vertical deflection waveform generating means for generating different vertical deflection waveforms; and one of a plurality of vertical deflection waveforms generated by the plurality of vertical deflection waveform generating means is periodically switched. 2. The image display device according to claim 1, further comprising: a selection unit for selecting a position of the raster, and a vertical deflection coil for setting a vertical position of the raster based on the vertical deflection waveform selected by the selection unit. 4. The method according to claim 1, wherein the plurality of electron beams include first to third electron beams, and the (3h + 1) th (h = 0, 1, 2,...) Scanning line is scanned by the first electron beam. The (3h + 2) th scanning line is scanned with the second electron beam, the (3h + 3) th scanning line is scanned with the third electron beam, and the first, second, and third electrons in the (N + 1) th frame are scanned. The vertical position setting means sets the raster position so that the scanning lines by the beam are respectively scanned at the positions of the scanning lines by the second, third, and first electron beams in the N-th frame. The vertical position setting means so that the scanning lines of the first, second and third electron beams in the frame are respectively scanned at the positions of the scanning lines of the third, first and second electron beams in the Nth frame. Sets the raster position, The vertical lines are so arranged that the scanning lines of the first, second and third electron beams in the (N + 3) frame are respectively scanned at the positions of the scanning lines of the first, second and third electron beams in the Nth frame. 4. The image display device according to claim 1, wherein the position setting means sets a raster position, and repeats the processing from the (N + 1) th frame to the (N + 3) th frame in a cyclic manner. 5. The method according to claim 1, wherein the plurality of electron beams include first to third electron beams, and the (3h + 1) th (h = 0, 1, 2,...) Scanning line is scanned by the first electron beam. The (3h + 2) th scanning line is scanned with the second electron beam, the (3h + 3) th scanning line is scanned with the third electron beam, and the first, second, and third electrons in the (N + 1) th frame are scanned. The vertical position setting means sets the raster position so that the scanning lines by the beams are respectively scanned at the positions of the scanning lines by the third, first, and second electron beams in the Nth frame, and the (N + 2) th frame The vertical position setting means so that the scanning lines of the first, second, and third electron beams in (1) are scanned at the positions of the scanning lines of the second, third, and first electron beams in the N-th frame, respectively. Sets the raster position, The vertical lines are so arranged that the scanning lines of the first, second and third electron beams in the (N + 3) frame are respectively scanned at the positions of the scanning lines of the first, second and third electron beams in the Nth frame. 4. The image display device according to claim 1, wherein the position setting means sets a raster position, and repeats the processing from the (N + 1) th frame to the (N + 3) th frame in a cyclic manner. 6. The plurality of electron beams are composed of first to third electron beams, and the (3h + 1) th (h = 0, 1, 2,...) Scanning line is scanned by the first electron beam. The (3h + 2) th scanning line is scanned with the second electron beam, the (3h + 3) th scanning line is scanned with the third electron beam, and the first, second, and third electrons in the (M + 1) -th field are scanned. The vertical position setting means sets the raster position so that the scanning lines by the beam are respectively scanned at the positions of the scanning lines by the second, third, and first electron beams in the M-th field. The vertical position setting means so that the scanning lines of the first, second and third electron beams in the field are respectively scanned at the positions of the scanning lines of the third, first and second electron beams in the Mth field. Sets the raster position The scanning lines by the first, second, and third electron beams in the (M + 3) field are respectively scanned at the positions of the scanning lines by the first, second, and third electron beams in the M-th field. 4. The method according to claim 1, wherein the vertical position setting means sets a raster position, and repeats the processing from the (M + 1) th field to the (M + 3) th field in a cyclic manner. Image display device. 7. The plurality of electron beams include first to third electron beams, and (3h + 1) th (h = 0, 1, 2,...) Scanning lines are scanned by the first electron beam; The (3h + 2) th scanning line is scanned with the second electron beam, the (3h + 3) th scanning line is scanned with the third electron beam, and the first, second, and third electrons in the (M + 1) -th field are scanned. The vertical position setting means sets the raster position so that the scanning lines by the beam are respectively scanned at the positions of the scanning lines by the third, first, and second electron beams in the M-th field, and the (M + 2) -th field The vertical position setting means so that the scanning lines of the first, second, and third electron beams in (1) are scanned at the positions of the scanning lines of the second, third, and first electron beams in the M-th field, respectively. Sets the raster position The scanning lines by the first, second, and third electron beams in the (M + 3) field are respectively scanned at the positions of the scanning lines by the first, second, and third electron beams in the M-th field. 4. The method according to claim 1, wherein the vertical position setting means sets a raster position, and repeats the processing from the (M + 1) th field to the (M + 3) th field in a cyclic manner. Image display device. 8. The plurality of electron beams include first to third electron beams, each frame includes three fields, and a raster position in each field includes a first position and a first position. A second position below one scan line interval;
There is a third position one scanning line interval above the first position, and the raster position in three fields in each frame is
The position is switched to the first position, the second position, and the third position, and in each of the first to third fields of three consecutive frames, the raster position is the first position,
The image display according to any one of claims 1 to 3, wherein the vertical position setting means changes the position of the raster for each field so as to switch between the second position and the third position. apparatus. 9. The image display device according to claim 1, further comprising a coloring means for coloring a white image in front of an image display surface of said cathode ray tube. 10. A coloring means for coloring a white image into first to third colors in front of an image display surface of the cathode ray tube, wherein a (M + 3i) field (i = 0, 1, 2,...) 7. The image of the (M + 3i + 1) field is colored to a second color, and the image of the (M + 3i + 2) field is colored to a third color. Or the image display device according to any one of 7. 11. A coloring means for coloring an image in first to third colors in front of an image display surface of the cathode ray tube, wherein a (M + 9i) -th field (i = 0, 1, 2,...) The image is colored in the first color, the image in the (M + 9i + 1) field is colored in the second color, the image in the (M + 9i + 2) field is colored in the third color, and the image in the (M + 9i + 3) field is colored. Color the image in the (M + 9i + 4) field to the third color, color the image in the (M + 9i + 5) field to the first color, and color the image in the (M + 9i + 6) field to the third color. The image of the (M + 9i + 7) field is colored with a first color, and the image of the (M + 9i + 8) field is colored with a second color. An image display device according to claim 1.