JPS5960851A - Color picture tube - Google Patents

Abstract

PURPOSE:To obtain a deflection yoke magnetic field giving a good convergence characteristic by placing the position of the maximum value of the vertical deflection magnetic field closer to the screen than the maximum value of the horizontal deflection magnetic field. CONSTITUTION:For making deviation to be zero in the formulas to express intensity of magnetic field: Hx=H10+H12.Y<2>+... (1), HY=HII0+ HII2.X<2>+... (2), HII2=0... (3) must be satisfied. Namely, the horizontal deflection magnetic field must be so-called uniform. For obtaining good convergence while becoming DELTAY=0, the magnetic field must be the so-called uniform magnetic field with regard to the horizontal deflection magnetic field while, with regard to vertical deflection magnetic field, it must be the pin-cushion magnetic field on the entrance side of the electron beam while being the barrel magnetic field on the exit side of the electron beam. Further, when the z-coordinate of the maximum value of the vertical deflection magnetic field is made to approach the screen side closer than the z-coordinate of the maximum value of the horizontal deflection magnetic field, the beam spot on the screen in case of deflection can be put in the good condition.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a color picture tube equipped with multiple electron guns, and particularly relates to:
A multi-electron gun relates to a deflection yoke of a color picture tube which is designed to emit two substantially parallel C electron beams in an undeflected state.

Technical background of the invention A conventional color picture tube will be explained using drawings.

The conventional so-called shadow mask or in-line color picture tube has a dot-shaped or strip-shaped phosphor layer that emits red, green, and blue colors when an electron beam strikes the inner surface I, as shown in Figure 1. A face plate (1) on which regularly arranged fluorescent surfaces (2) are adhered, and inner wall writing on the side walls (ii) of the face plate (1) = a plurality of panel bins installed (5) Kannispring (6).

A shadow mask (8) with a large number of openings (holes for electron beam passage) provided at predetermined intervals on the fluorescent surface (2) through a mask frame (4), and a shadow mask (8) with holes formed therein as required. Inner shield 04) arranged accordingly and side wall part (1
-1) through a funnel (Te) to a color picture tube body connected to a neck (9) housing an electron gun (1 (I);
It is fixed to the outer wall of the neck (9) by the support part (8-1), and there is a pattern (
8-2), and an adjusting magnet (11) attached to the outer wall of the neck (9). In such a color picture tube, the electron beam Og1 emitted from the electron gun OQ is focused, accelerated, and deflected while passing through the opening CIB) of the shadow mask (8) to the fluorescent surface (2). A predetermined phosphor layer is made to emit light.

The electron gun aO) normally has Ft, G, and
B Form three electron beams. In these color picture tubes, generally called 3-beam shadow mask tubes,
Currently, the mainstream electron gun is an in-line electron gun, in which three electron guns are arranged horizontally in a row.

In a color picture tube using such an in-line electron gun, R.

Each electron beam (hereinafter referred to as R, (), and B beam) that causes G and B color phosphors to emit light is transmitted through a deflection yoke (8).
When C2 is not operated and there is no deflection, the dimensions of the focusing electrode of the electron gun 00) are designed to concentrate at one point on the fluorescent surface (2). However, in reality, the electron gun (2) and shadow mask (8) are not accurately focused due to assembly errors, etc., so fine adjustment is performed using an adjustment magnet 01).

In addition, in an in-line electron gun, if the magnetic field of the deflection yoke (8) is appropriately designed,
It is possible to simultaneously pass the B3 beam through C2 at one point of the shadow mask (8). The color picture tube C2 with an in-line electron gun is capable of a so-called dynamic convergence-less magnetic field design, and compared to those with a delta-type electron gun, there is no need for a convergence yoke and complicated adjustment is possible. Most current color picture tubes use in-line electron guns because of the many advantages such as no need for an in-line electron gun. An example of a dynamic convergenceless magnetic field will be explained with reference to FIG.

The DYNAKITSU convergenceless magnetic field is shown by the solid line C2, the vertical deflection magnetic field is a so-called barrel magnetic field whose strength decreases as it moves away from the center, and the horizontal deflection magnetic field shown by the broken line (the acupuncture needle moves away from the center). This is a so-called bottle cushion magnetic field whose strength increases as the magnetic field increases.When the magnetic field is distorted from a so-called uniform magnetic field that is the same regardless of the distance from the center, a dynamic convergence magnetic field is realized by C2. Furthermore, a method in which pattern distortion, which was conventionally corrected by a circuit, is removed by a deflection magnetic field is becoming common, and such a magnetic field tends to further intensify the distortion of the deflection magnetic field.

Problems with the Background Art By the way, when the distortion of the two-polarization magnetic field becomes stronger, good convergence or pattern distortion characteristics can be obtained, but problems appear in other aspects.

That is, by distorting the deflection magnetic field f2, the spot of the electron beam becomes increasingly distorted. Therefore, when the electron beam is deflected, the electron beam spreads, and the so-called "one-shot blur" increases, which significantly reduces the resolution around the screen, which is the cause C2 of not being able to obtain a satisfactory screen.

Furthermore, when the electron beam spot around the screen expands, the electron gun design is forced to compromise between the center of the screen and the periphery of the screen, which is a major obstacle in terms of electron gun design.

Further, Japanese Patent Publication No. 57-4061 describes a dynamic convergence device using a color television receiver using a video signal delay device. According to the present invention, the color picture tube is designed so that the three electron beams are not concentrated at one point f2 on the shadow mask in a state where the deflection yoke is not operated, that is, in a non-deflected state l2, and in a state where so-called static convergence is insufficient. As a result, R,G
, B3 beams are not concentrated on the screen, resulting in color shift in the three-color pattern. In FIG. 3, if the R, G, and B3 beams are accurately focused, the correct screen will be reproduced. R9G,B
In the case of a three-beam static comperience deficiency, the pattern is as shown in Figure 31'' (31B),
(31G), (31R), (32B), (32(
)), (32R), resulting in an image with color shift. This color shift is delayed to some signals 1' of the RlG and B3 beams to reproduce the image correctly. Therefore, if a correct delay is given to the image signal port (31R).

(31G), (31B) and (a2R), (32G
) and (32B) match, and a correct image is reproduced. However, when the delay is performed using this method, R and G are displayed on the entire screen.

It is impossible to match the B3 beams, so methods such as distorting the deflection magnetic field and attaching permanent magnet pieces to the deflection yoke are also used. Therefore, as a result, the magnetic field is also distorted, and the beam spot distortion remains. In addition, since permanent magnet pieces are used, the deflection yoke has large variations and is far from practical.

The discontinued U.S. Pat. No. 2,764,628 shows a color television in which multiple electron guns are formed in parallel when not deflected, but nothing is mentioned about the two deflecting magnetic fields C. Therefore, it is clear that a good screen cannot be formed using this method.

OBJECTS OF THE INVENTION In view of the situation C, an object of the present invention is to provide a deflection yoke magnetic field that provides good convergence characteristics in a color television device using a delay circuit or the like.

Summary of the Invention The present invention is equipped with a multi-electron gun, in which the electron beams emitted from the multi-electron gun are formed into a substantially parallel 1' beam in an undeflected state, the horizontal deflection magnetic field is made uniform, and the electron gun side of the vertical deflection magnetic field is made into a bin. In a color picture tube ζ2 with a cushion magnetic field and a barrel magnetic field on the screen side, if the maximum value of the vertical deflection magnetic field is located closer to the screen than the maximum value of the horizontal deflection magnetic field, the beam spot on the screen will be The purpose is to have less spread and less distortion.

Embodiments of the Invention First, based on the drawings, a color television using a delay circuit (two explanations will be given).The numbers in FIG. do.

141) in FIG. 4 C2 is a signal source, generally Rl
Supplies signals to drive the G and B color electron guns.

(42G) and (42B) are delay circuits, and in Fig. 4, the signals that drive the G beam and B beam [although inserted in two pairs, there is a delay for all three color signals of R, G, and B. Alternatively, the delay may be delayed for one or two arbitrary colors C2. Printing is R, G, B3
A color electron beam is shown, and although tl is parallel in FIG. 4, it may be tilted to some extent.

Now, FIG. 4 shows the state of the electron beam in a state where the electron beam is not deflected. Here, it is most preferable for the delay circuit to provide a constant delay time, and if the deflection magnetic field is formed in this way, a suitable result can be obtained. That is, in order to make the delay time variable, the delay circuit itself must be complicated and an additional circuit for controlling the delay circuit is required, which is undesirable from both cost and technical standpoints. Therefore, in an in-line electron gun color picture tube, for example, when a white grid is displayed on the screen, when the delay circuit is not activated, the entire screen is R, ( ), it is necessary that the positional deviations △W of all 133 colors be the same.Here, assuming that the horizontal lines are the same,
It is expressed with a single line.

Tokoguchi, Philips Research Report by Johan Berntenis and Gerrit, Jan, Ruthven et al., Volume 12, Volume 4.
According to the 1957 paper (2), pp. 6-48, the convergence error appears as follows. This will be explained below with reference to the drawings.

In FIG. 6, among the coordinate axes forming an alternating CM angle, the z-axis indicates the axis of the picture tube, the two positive directions indicate the traveling direction of the electron beam, and the X-direction and Y-direction each indicate the deflection direction of the electron beam. In FIG. 6C, %RIGIB electron beams are generated from three electron guns each and strike two R+G+B color phosphors (assumed to be undeflected at Z=ZQ). , the incident position of the child beam z-2o is respectively at the X and Y coordinates: E B , y@, and the incident angle is 30@' in the X direction and g2 in the Y direction, respectively.
Assuming that y5' is the deviation from the so-called Gaussian deflection, the deflection error in the general sense ΔXCX direction) and Δy (X direction) are expressed as follows.

tx= Al-Xa8+(As"B8)Xa-Ys"+
(4%'B5Ys")ffis'++()v+b)・X
s'Ys"/s"A1'Xa"s"A8'Xa'9a"
""2 B8 ・Ys -Zti"3'a'+ (Ag
Xs 2+ BIOYs “%a” (Bll”
Al5) XaYaffa ”BB ”A18Xll”II ”A14Xsya”B15Y
a”sys”A, 16Xa”a”a”+Bl?°Y8°
'/B"B + A18°Xs "ya"/a +B
18Ya"s3'5----------------------
(1-d)△7 = Bly, 8+(BB +AB)
Xs"・Ya"(B4ya""A3X5Q3's'"
(A6"Ba)Xs'Ys"s"B?Ya3's'
""B8'Ys"s""2A8'Xs・xa"'/s
'+ (B9 ・Ys""A10Xa")ya +
(A11 +B111) ・x, ・Ya +r, +
1318 ・ya 1 y, l ++ B14Ya"s
""A15Xa 'Zs'9a" B16
'Ya "1m 'ffs'" AI? Xs or,・
'JB'++BIQYa"a"a -----------
An and Bn (n = 1..., 18) are respectively a function of magnetic field strength and a function of deflection + Xll is Z = Z
The magnitude of the deflection in the X direction on the s-plane is Z =
The size v in the Y direction on the plane Za. Symbols such as ZO+Za each indicate the coordinate values shown in FIG. Here, in the Cm of the present invention, mainly when the R, G, and B3 electron beams are almost parallel, it is handled even if there are two C, and Rt G t B3
Since the electron beams are arranged in a horizontal C knee straight line, xa'=0, 31. '= 0.3's = 0
The case is 1, and s (1-a), (1-b)
Substituting these values into formula C2:

△2=A1"Xs"(A20B8)Xa-Ys"" (
A9'Xs"B10'Ya2)"s"AIB'Xa・X
a”−−−−−−−−−−−−−−(2−a)Δ'/
= Bl-Ys8+(B2"Aa)・xs"・Ys+
+(All"B12)'Xa'Ya・y:a"B14'
Yg"'a"---1---------(2-
b) Here, (2-σ), (2-b) In both equations, the first
The second term is a term representing linearity distortion and graphical distortion, and is excluded because it is unrelated to the convergence term.
△'C= (AoXs"B]o°Ya2)・"a" A
15-Xs ・xs ” −−−−−−−−
------(3-a)△'/'' (A11 +Bl
s) ・xB ・Y, +! .

"B14'Ys" 5lI----------------------
(3-b). Therefore, in order to make the error zero, C2 is A9+ BI B+ A1 B+ Al l
``Bl 2+ B14 should be all zero 0 Here, the formula representing the magnetic field strength HIO + HIIa is in the plane where x = 0 (the formula representing the magnetic field strength HX in the X direction in 2)%
It shows the coefficient in the formula % (4) and is a function of HIO+HI8 times 2. Further, Z = ZQ indicates the deflection start point and zezl deflection end point. Also, K is a proportionality constant, Y and Y' are respectively ・J
(IY Y = y(z) and Y dZ indicates the degree of deflection and deflection change in the Y direction, and when z = z6, Y = Y' =
It is O.

In addition, HjO+ B12 represents the coefficient in the formula % formula % which indicates the magnetic field strength HY in the X direction in the plane Y=O, and X and X' are respectively X2X(
z) and x'= (LX/az, which indicates the degree of deflection and deflection change in the X direction, and when Z=ZQ, X = X'=
It is O.

Here, the condition for making the deflection error zero is expressed as follows.

−−−−−−−−−−−−−(γ) Therefore, (6L(When formula (1) is transformed using partial integration, −−−−−−−
−−−−−−−(12(11), since the Cm formula holds true regardless of the amount of deflection of X, mFi [I9 = 0
−−−−−−−−−−−−−−−−
− <18) must hold true. That is, the horizontal deflection magnetic field must be uniform. It has been experimentally confirmed that practically no error occurs if 4dlHtgl≦5.0Nilsted/cm2, so in the present invention, if this condition is satisfied, the horizontal deflection magnetic field is said to be uniform. Using the condition of equation (18), ----
--------------(1→What is important here is the direction of each electron beam in FIG. 5).

i'; In i and m, the three colors R, G, and B are drawn as if they are aligned in the horizontal direction, but in reality there is a considerable deflection error, and this deflection error can be expressed as a Δy error. It is represented above. If such a Δy error exists, the delay circuit must provide a delay time for several horizontal deflection scanning lines. Also, since the value of △y changes with the deflection -°, the delay time must be controlled variablely (two times), and even if it is possible, since the unit of variable time is controlled by the scanning line axis, Image quality deteriorates significantly. However,
Such control is not possible in practice. In other words, it is clear that this method is not suitable for practical use because it causes discontinuity in the scanning lines and the like, resulting in misalignment on the screen.

Therefore, it is an essential condition that the formula (Special C Part 2) holds true. Late C22 (Z-Zs) Hllll” H'IO= O---
−−−−−−−−−−αφ must hold true.

It is clear from the above explanation that in this case C2Δy=Q and good convergence can be obtained.

As shown in Figures 7 and 8, the magnetic field that satisfies the above conditions is a so-called uniform magnetic field for the horizontal deflection magnetic field, a so-called bottle cushion magnetic field for the vertical deflection magnetic field on the electron beam entrance side, and a so-called barrel magnetic field on the electron beam exit side. It's good to have. However, in FIG. 7, the horizontal deflection magnetic field is shown by a broken line. If the polarization direction of the vertical deflection magnetic field is positive, the vertical deflection magnetic field will be negative due to the way the coordinate axes are taken, but here it is easy to understand C: The direction of the magnetic field is assumed to be positive.

By the way, it is understood that with a deflection magnetic field having such a magnetic field distribution, it is possible to obtain good convergence and a relatively good electron beam spot shape on the screen surface of a so-called parallel beam type color picture tube. However, it turns out that it is still not possible to obtain a beam spot as small as C2 with this method alone.Therefore, consider the spread of the electron beam spot on the second screen surface by C2.The spread of the electron beam spot due to deflection is expressed in the form Since the treatment of the convergence error is the same as that of f2, it can be expressed as follows.In other words, since the spread of the electron beam spot on the screen surface is considered to be the dispersion of the beam's advancing angle, ΔJ' = (A4Xa'' + ]354s ")'
Xs'+(A6 +B6) ・Xa ・Ylya""
AV'Xa=a""A8'Xs'3's""2B8Ya
・:cs”ffs’ −−−−−−−−(ff)Δy=
cv-re "Ys""AsXs") ef
fs” (Aa ”Be) Clear Ya Medium gs'+
"B7"Yg'3'g"+Ell"Ya"a""2Ag
'Xs''a''ys'---08).

Also, consider separately the case of only horizontal deflection and the case of only vertical deflection. In case of horizontal deflection, Y8=0, so ""=A4'Xs""a"A7・Xs"s" A8-”
a・3's" -------1--9 groan Δy=g-x
a2・3'a"2・Be・-・xa'・ys'
-----------(21).

Here, in an actual color picture tube, the main error in ΔxH2 is astigmatism, so the main term of the error is expressed with a subscript - (the same applies hereinafter).

(6g) −= A+・xaL, gs' -----
−−−−−−−−−−−(2) becomes 1.

Also, the main term in Δy is astigmatism based on 1, (Δy) dwnL = A5・XB2・y, /
, −−−−−−−−−−−−1 (transformation))−−1−
−−−−−−−−−(goods).

Here, since the first term of the (goods) equation is always positive, the second term must also be positive. In addition, in an actual color picture tube,
・(Z-Z, )'' is known to have a distribution Cyu as shown in Figure 9 (provided that the deflection is to the horizontal end of the color picture tube). Therefore, the second term of the set The numerator of the integral function has a distribution (two) as shown in Figure 10C.Also, in order to make the set zero, the second term should be negative,
Therefore, for C, it is sufficient to attach HIO to two sides of C on the electron gun side.

In the case of only C-order vertical deflection, X8=0, and △−f
= B54g"!B' + 2BB・Ys・"s"
/a'------H△'/ = B4
°Ya', %' + B7°Y8°yB”' +B8°
"f8・x8'2------IJfn.

Next, the main term of △y is (Δy) damb = B7°'IB”/II”
−−−−−−−−−−−1271−](“,
°HIS = 0) −−−−−−−−−−
---μs).

Therefore, considering the next largest term (△y) jub, (△y) −1sdr = B4・y, 51・y8
' ~------------(291).

Here, if the second term of equation (2) is made negative, Δy becomes close to zero C. The integrand of the second term of equation (80) is shown in Figure 11 (
a) to (a) r is added. In other words, it is only necessary to make the integrand positive (secondly, it is clear that the vertical deflection magnetic field should be brought closer to the screen side, opposite to the horizontal deflection magnetic field. Also, Fig. 11(a) In (a) to (a), since the Y deflection direction is positive, HIQ is in the negative direction.

In the case of only vertical deflection, ΔX is almost zero, so there is no need to consider it in practice.

As described above, by bringing the magnetic field distribution of the vertical deflection magnetic field closer to the screen side than the magnetic field distribution of the horizontal deflection magnetic field, the beam spot on the screen when deflected can be made in a good condition.

It has been experimentally confirmed that in practice, it is possible to achieve the objective by placing the two coordinates of the maximum value of the vertical deflection magnetic field on two sides of the screen closer to the two coordinates of the maximum value of the horizontal deflection magnetic field.

By using a deflection magnetic field with such a magnetic field distribution, it is possible to create a color picture tube with less color shift and less spread of the beam spot on the two-screen during deflection, which reproduces high-quality images. did it.

However, the substantially parallel electron beam in the present invention refers to one having an inclination within the range of the conventional force 2 - the concentration angle of the picture tube.

Effects of the Invention As described above, according to the present invention, a color picture tube using substantially parallel electron beams can be realized with less distortion of the beam spot on the screen, and has great industrial value. big 0

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view to explain a conventional color picture tube, Figure 2 is a schematic diagram to explain the magnetic field distribution of a conventional color picture tube, and Figure 3 is a schematic diagram to explain convergence error. Figure 4 is a schematic cross-sectional view showing a color picture tube using a parallel electron beam, Figure 5 is a schematic diagram showing the screen of a color picture tube using a parallel electron beam, and Figure 6 is a deflection diagram of the color picture tube. A conceptual diagram to explain the error, Figure 7 is a qualitative diagram showing the distribution of the horizontal deflection magnetic field, and Figure 8 is a vertical (α) diagram.
C(1) is a qualitative diagram representing the integrand term representing the beam spot distortion of the horizontal and vertical deflection magnetic fields.
...Face spray) (2)...Fluorescent surface (8)
・・Shadow mask (4) ・・Mask frame (6
)...Panel bin (6)...Spring (7
)... Funnel (8)... Deflection yoke (9
)... Neck scream... Electron gun (11)...
・Adjustment magnet (2)...(21)...Screen periphery Warm...Horizontal deflection magnetic field -)...Vertical deflection magnetic field (81)...Image 921...Image
Song...Signal source sound...Delay circuit (9)1.
...Electron beam +511. (52), ■... Lattice image f61. (621, Warm, Housing O)...Mask periphery...Horizontal deflection axis ((6)...Vertical deflection axis -
...Horizontal deflection meridional concentration point■)...Horizontal deflection sphere defective concentration point~ Shin)...Heavy electric deflection sphere defective concentration point-)...Vertical deflection meridian concentration point 112 Figure 3 figure

Claims (1)

[Claims] It is equipped with a multi-electron gun, and the electron beam emitted from the multi-electron gun is formed into two substantially parallel beams in an undeflected state, the horizontal deflection magnetic field is uniform, the electron gun side of the vertical deflection magnetic field is a bottle cushion magnetic field, and the screen side is a bin cushion magnetic field. A color picture tube 62 having a barrel magnetic field, characterized in that the position of the maximum value of the vertical deflection magnetic field is located closer to the screen i2 than the position of the maximum value of the horizontal deflection magnetic field.