JP2937391B2 - Color cathode ray tube - Google Patents

Description

Description of the Invention [Object of the Invention] (Industrial application field) The present invention relates to a color cathode ray tube, and particularly when the focusing electric field of the electron beam changes, the degree of concentration of the three electron beams is excessive or insufficient. The present invention relates to a color cathode ray tube having an in-line type electron gun having a means for compensating for the color cathode ray tube.

(Prior Art) As shown in FIG. 11, an in-line type electron gun assembly in a conventional color cathode ray tube has a cathode (2) containing a heater (1), a first grid (3) integrally formed with each of them,
The main electron lens (L ₁ ) includes a second grid (4), a third grid (5), and a fourth grid (6). Jujiku (Z _G), the gun axis of each side electron gun _{(Z B), (Z R} ) openings drilled around the _{(5 G), (5 B} ), a third with a (5 _R)
A grid (5), an opening (6 _G ) drilled about the gun axis (Z _G ) of the central electron gun at the bottom of a bottomed cylindrical body also formed mechanically integrally, and a gun for both electron guns axis _{(Z B), (Z R} )
Opening is drilled off-center with respect to (6 _B), is formed between the (6 _R). In this case, as shown in Japanese Patent Publication No. 52-32714, the central electron gun has an opening (5 _G ).
And (6 _G) and is Jujiku (Z _G) so are bored around the central electron beam (9 _G) is straight in the phosphor screen direction is not shown as it is, the electric field on both sides electron gun sides electron beam passing through the electric field by the asymmetrical _{(9 B), (9 R} ) allowed bending the central electron beam (9 _G) direction, these three electron beams (9 _B), (9 _G ),
( _9R ) is designed to be concentrated on the phosphor screen.
As a means for making the electric field asymmetric, Japanese Patent Publication No. 53-38076
As disclosed in Japanese Patent Application Laid-Open Publication No. H11-260, there has been proposed a device using an inclined opening electrode.

The above-mentioned electron gun assembly is preferable in terms of cost and accuracy because the configuration of each electrode is mechanically simple and the relative positions of the electron lenses of the three electron guns are determined accurately. There is something to be done. That is, eccentric or inclined openings are used to concentrate the three electron beams at predetermined positions. The amount of deflection of the electron beam by the asymmetric electron lens formed by the eccentric or inclined opening is approximately proportional to the amount of eccentricity or inclination and the potential difference between the electrodes forming the electron lens. That is, the deflection angle (amount) by the asymmetric electron lens is approximately given by the following equation.

θ = k · p · q (1) where θ is the deflection angle, k is a constant, p is the amount of eccentricity that normalizes the electron lens diameter, and q is the voltage ratio of the electron lens.

Therefore, if the voltage applied between the electrodes forming the electron lens is incorrect, the deflection angle θ changes. As a result, when the deflection magnetic field is not applied to the color cathode ray tube, that is, the static concentration at the center of the screen shifts. Problems arise.

For example, a bipotential electron lens (Bi Potenti
al Focus: hereafter abbreviated as BPF).
A voltage of 25 kV to 32 kV is applied as an accelerating voltage to the grid, and a design voltage of 25% to 35% of the accelerating voltage is applied to the third grid, but is actually applied due to an assembly error of related parts. The voltage causes an error of about ± 1% with respect to the design voltage. This is a size that cannot be ignored with respect to the concentration of the electron beam.

In particular, a recent color cathode ray tube was mounted on the neck outer wall of the vacuum envelope of the cathode ray tube as shown in JP-B-51-45936, for example, as shown in Japanese Patent Publication No. 51-45936, for final adjustment as a cathode ray tube before being mounted on a receiver. In the case of the preset type, where adjustment is performed to match the three axes of the tube axis, electron gun axis, and deflection device axis by adjusting the magnetic field distribution of the permanent magnet, and no adjustment is made after mounting on the receiver, as described above. Especially when the potential difference between the electrodes forming the electron lens needs to be accurate, as in an electron gun structure having a structure, the electron gun operating conditions during adjustment of the cathode ray tube, particularly the voltage applied to the third grid (5). Is incorrect, it becomes necessary to readjust it after attaching it to the receiver, which leads to deterioration of work efficiency.

Some proposals have been made for such a problem caused by the change of the focusing electric field. For example, as shown in FIG. 12, in Japanese Patent Publication No.
A first electron lens (L ₁ ) is formed between the grids (8), and a second electron lens (L ₂ ) is formed between the third grid (5), the fourth grid (6), and the fifth grid (7). And the first
An example in which the two electron beams (L ₁ ) and the second electron lens (L ₂ ) are made to have two asymmetric electron lenses in which the openings facing each other are decentered, so that the electron beams on both sides are deflected and concentrated at a predetermined position. It is shown. However, exclusively in such a structure, the electron beam deflected by the _second electron lens (L ₂ ) passes through the tube axis side of the first electron lens (L ₁ ), and the first electron lens (L ₁ ) L ₁ ) causes coma. As a result, there is a problem that the electron beam on both sides produces a halo in the lateral direction.

Japanese Patent Application Laid-Open No. 55-37798 discloses that, in an electron gun composed of a first asymmetric electron lens and a second asymmetric electron lens, the two-sided electron beam deflected by the _second electron lens (L ₂ ) is incident is inclined approximately at the center portion of the first electron lens (L _1), and an opening portion of the counter electrode to form a first electron lens (L ₁₎ is also eccentric. This complicates the electrode structure and increases the types of electrodes. Therefore, it is extremely difficult to assemble each electrode of the electron gun with high precision, and the resolution may be degraded.

Further, in Japanese Patent Publication No. 1-4109 and JP-A-55-37798, both the first electron lens (L ₁ ) and the second electron line (L ₂ ) merely deflect the electron beam on both sides in the in-line direction. Instead, it has the function of focusing in the in-line direction and in the direction perpendicular to the in-line direction. FIG. 13 schematically shows the positional relationship between the electron lens system and the object point. If the second electron lens (L ₂ ) for compensating the degree of concentration is ignored, the electron beam emitted from the virtual object point VP on the axis is determined by the first electron lens (L ₁ ) for focusing. Has been established. However, in practice, the second electron lens (L ₂ ) also has a converging function, so that there is a drawback that the virtual object point VP is shifted. In particular, since the second electron lens (L ₂ ) is an asymmetric electron lens, the first electron lens (L ₁ )
Is distorted. Therefore, the first
Since the object point viewed from the electron lens (L ₁ ) deteriorates, there is a disadvantage that the spot diameter of the phosphor screen increases and the resolution decreases.

(Problem to be Solved by the Invention) The problem to be solved by the present invention is that the three electron beams caused by the change of the concentrated electric field of the electron beam in the main electron lens of the in-line type electron gun in the color cathode ray tube described above. It is an object of the present invention to provide a high-resolution electron gun that suppresses a substantial change in the degree of concentration and does not deteriorate the spot diameter at a predetermined position on the phosphor screen. For this reason, means for compensating for the excess or deficiency of the concentration of the three electron beams while maintaining the focusing characteristics in the main electron lens is provided, and a high-resolution color with no deterioration of the spot diameter at a predetermined position on the phosphor screen is provided. It is to provide a cathode ray tube.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an in-line type electron gun including a cathode for emitting three electron beams arranged in-line at the center and both sides, and In a color cathode-ray tube having a phosphor screen facing the in-line type electron gun, the electron lens system of the in-line type electron gun includes a high-voltage electrode to which a high voltage on the phosphor screen side is applied and the cathode side. A low-voltage electrode which is located on the cathode side of the high-voltage electrode and to which a low voltage lower than the high voltage is applied, and which focuses and concentrates the three electron beams at a predetermined position.
And an opening common to the three electron beams to which a low voltage having substantially the same potential as the voltage applied to the low voltage electrode on the cathode side of the first electron lens is applied. And a second electron lens portion comprising a counter electrode having a phosphor screen side electrode of the counter electrode constituting the second electron lens, which is substantially elongated in the in-line direction and has an opening in the in-line direction. Both ends have an opening having an opening diameter perpendicular to the in-line direction larger than the substantial beam passage area, and the cathode so as to sandwich the in-line surface from an opening side along the in-line direction forming the beam passage area. A pair of correction electrode members extending to the side, and extending the correction electrode member into the cathode side of the cathode side electrode of the counter electrode, the low voltage electrode of the first electron lens and the second electrode. Electronic The second electron lens deflects the electron beams on both sides in an in-line direction by making the low voltage applied to the electrode on the phosphor screen side of the lens variable, so that the three electrons of the first electron lens are deflected. A color cathode ray tube characterized in that the degree of concentration of a beam is compensated for.

(Function) As described above, in the present invention, the electron lens system of the in-line type electron gun in the color cathode ray tube is divided into the first electron lens portion and the second electron lens portion, so that the second electron lens is formed. The first electronic lens has a function of compensating for the excess or deficiency of the degree of concentration. That is, by using the second electron lens as an electron lens having a deflecting action in the in-line direction only when a potential difference is generated between the electrodes forming the electron lens, the electron beams on both sides of the three electron beams are shifted in the in-line direction. To compensate for excess or deficiency of the degree of concentration of the electron beam of the first electron lens. This makes it possible for the second electronic lens to perform the degree of concentration compensation while keeping the first electron lens with the focusing characteristic. In addition, by making the second electron lens large in diameter, the function of each electron beam for focusing and diverging is reduced, and the function of deflecting the electron beams on both sides in the in-line direction is maintained. Here, the compensation operation will be described as follows. That is, when the strength of the first electron lens matches the design value, there is no potential difference between the opposing electrodes forming the second electron lens. Only the three electron beams are appropriately focused and focused on the phosphor screen. However, when the electron beam is properly focused on a predetermined position while the strength of the first electron lens is higher than the design value, the first electron lens alone causes an over-concentration state. In this case, the second electron lens acts to deflect the electron beams on both sides in a direction away from the central electron beam, so that the three electron beams are properly concentrated on the phosphor screen. On the other hand, when the electron beam is properly focused at a predetermined position while the strength of the first electron lens is weaker than the design value, the three electron beams are under-concentrated. At this time, the second electron lens deflects the electron beams on both sides in a direction approaching the central electron beam, so that the electron beams are appropriately concentrated on the phosphor screen.

(Embodiment) An embodiment in which the present invention is applied to a color cathode ray tube which emits three electron beams arranged inline in the horizontal direction will be described below with reference to the drawings.

FIG. 1 illustrates the invention in a three-line arrangement in a horizontal direction.
FIG. 2 is a cross-sectional view of the in-line type electron gun taken along the XZ plane (horizontal plane) in an embodiment used for an electron gun of a color cathode ray tube for emitting electron beams, and FIG. 2 is an in-line type electron gun in FIG. It is sectional drawing in the YZ plane (vertical plane) of a gun. Hereinafter, horizontal means inline,
The vertical direction means a direction perpendicular to the in-line direction.

As shown in FIGS. 1 and 2, the in-line type electron gun of the color cathode ray tube according to the present invention comprises a cathode (2) containing a heater (1), a first grid (3) integrally formed with a cathode (2), and a first grid (3). 2 grid (4), 3rd grid (5),
The first electron lens (L ₁₀ ), which is composed of a fourth grid (6) and a fifth grid (7), and is a focusing lens, has a gun shaft of a central electron gun at the bottom of a mechanically integrally formed bottomed cylinder. (Z _G), the gun axis of each side electron gun _{(Z B), (Z R} ) openings drilled around the _{(6 G), (6 B} ), a fourth with a (6 _R)
Grid (6), also mechanically gun drilled opening and (7 _G) on either side electron gun around a central electronic gun gun axis at the bottom of the (Z _G) of the integrally formed bottomed tubular body axis _{(Z B), (Z R} )
Opening bored in eccentric (7 _B) with respect to, it is formed between the fifth grid having (7 _R) (7).

The second electron lens (L ₂₀ ) is formed between the third grid (5) and the fourth grid (6). FIGS. 3A and 3B show the shape of the opening of the electrode forming the second electron lens. FIG. 3 (a) shows a common opening (10) at the bottom of the third grid (5) on the phosphor screen side as a cathode electrode of the counter electrode, and FIG. 3 (b) shows a phosphor screen side of the counter electrode. The common opening (11) at the bottom of the fourth grid (6) on the cathode side is shown as an electrode. As shown in FIG. 3A, the horizontal opening diameter w common to the three electron beams (9 _B ), (9 _G ), and (9 _R ) is located at the bottom of the third grid (5) on the phosphor screen side. _5, there is an opening of the vertical opening diameter h ₅ (10). Further, the cathode-side bottom of the fourth grid (6) FIG. 3 (b) are shown as three electron beams (9 _B), (9 _G), a common horizontal aperture diameter (9 _R) substantially horizontally elongated opening of w ₅ has (11), the opening (11) is horizontal opening diameter w _6, 3 electron beams in the vertical opening diameter _{h 6 (9 B), (} 9 G ), (9 _R ) pass through a substantial beam passage area (12), and a vertical aperture diameter which is continuous with the substantial beam passage area (12) on both horizontal sides is h _5.
(13). Where each opening length is
h ₆ <have a relationship of _{h 5, w 6 <w 5} . A pair of correction electrode members (14) are provided extending from an opening side along the horizontal direction forming the beam passage area (12) to the cathode side so as to sandwich a horizontal plane, and the correction electrode member (14) is a cathode electrode. The third grid (5), which is a side electrode, extends from the opening (10) on the phosphor screen side to the inside of the cathode and is formed in a parallel plate shape.

In the above description, in the embodiment, the low-voltage electrode constituting the first electron lens and the phosphor screen side electrode of the counter electrode constituting the second electron lens are the same electrode, that is, the fourth grid (6). However, the present invention is not limited to this, and the low-voltage electrode and the phosphor screen electrode of the counter electrode may be different electrodes.

In the electron gun configured as described above, the anode acceleration voltage _Eb is applied to the fifth grid (7), and a voltage of about 25% to 35% of the anode acceleration voltage, the so-called focusing voltage V, is applied to the fourth grid (6). _{Apply f} . In this case, in the central electron gun, the openings (6 _G ) and (7 _G ) are drilled about the gun axis (Z _G ), so that the central electron beam (9 _G ) is not directly shown on the fluorescent screen (not shown). However, the electron beams (9 _B ) and (9 _R ) passing through the electric field are bent in the direction of the central electron beam (9 _G ). Book electron beam ( _9B ), ( _9G ), ( _9R )
Is designed to concentrate on a predetermined position on the phosphor screen. Here, the third grid (5) has the fourth grid (6).
When a voltage having substantially the same potential as that of the fourth grid (6) is supplied from a power source different from that of the fourth grid (6), there is no potential difference between the fourth grid (6) and the third grid (5). Not done. However, the focus voltage V _g which is shifted from the design value 4
When three beams are concentrated on the phosphor screen by applying to the grid (6), a potential difference occurs between the third grid (5) and the fourth grid (6). The potential difference and the opening shapes shown in FIGS. 3A and 3B form an asymmetric lens as a second electron lens (L ₂₀ ) having a concentration correction action.

The operation of this asymmetric lens will be described with reference to FIGS. 4 to 6 showing the potential distribution, and FIG. 7 showing the lens operation and the electron beam trajectory on the XZ plane. In the figure, the X axis is horizontal, Y
The axis is the vertical direction, and the Z direction is the tube axis, that is, the axis of the central electron beam when there is no deflection. As shown in FIGS. 4 and 5, an axially asymmetric lens is formed between the third grid (5) and the fourth grid (6). As shown in FIG. 4, in the Y-axis direction, the electron beam trajectory is substantially located near the center of the lens, and the potential difference between the third grid (5) and the fifth grid (6) is several Because it is 100 volts, Y
The axial lens action is small. Also, as shown in FIG. 5, in the X-axis direction, a weak lens as shown by equipotential lines is long and gently formed in the tube axis direction (Z direction),
Appropriate deflection action is given to the electron beams on both sides. Further, in the present invention, as shown in FIG. 6, the equipotential lines slightly penetrate into the correction electrode member (14). This is because the presence of the opening end (13) having a large vertical opening diameter shown in FIG. 3 (b) of the opening (11) provided on the cathode side bottom of the fourth grid (6) causes the correction electrode member (14). This is an effect due to the fact that the electric field concentrated at the end of () is reduced. Therefore, the individual electron beams can be deflected in the horizontal direction with as little distortion as possible. Next, the compensation operation will be described with reference to a schematic lens model. In FIG. 7, the trajectory is the case where the voltage of the fourth grid (6) is the same as the design value _{Vf of the} focusing voltage and there is no potential difference with the third grid (5). Therefore, the second electron lens is not shown because it does not work. In this case each side electron beam _{(9 B), (9 R} ) is focused simultaneously be focused on the fluorescent screen by the first focusing lens which is an electron lens (L _10). Next, when the focusing voltage of the fourth grid (6) is V _g1 higher than the design voltage V _{f, the} voltage of the third grid (5) is fixed at the focusing voltage V _f , so that the second electron The asymmetric lens (L ₂₀ ) as a lens acts as an electron lens (L ₂₁ ) having a converging property in the horizontal direction (X-axis direction), and the electron beams (9 _B ) and (9
_R) is deflected toward the central electron beam (9 _G). At this time, a focusing lens (L
_{Since the} degree of concentration in ₁₀ ) is lower than the design value, the degree of concentration as a whole is substantially the same as the design value. This corresponds to the state when the trajectory in FIG. On the other hand, when the focusing voltage of the fourth grid (6) is V _g2 lower than the design voltage V _f , the asymmetric lens (L ₂₀ ) as the second electron lens moves in the horizontal direction (X Acts as an electron lens (L ₂₂ ) that exhibits divergence in the axial direction), and electron beams (9 _B ), (9
_R) is deflected in a direction away from the central electron beam (9 _G). At this time, since the degree of concentration of the focusing lens (L ₁₀ ) increases contrary to the previous example, the degree of concentration becomes substantially the same as the design value as a whole. The trajectory in FIG. 7 shows the state at this time.

The distortion and deflection angle of the electron beam affect the length l of the portion where the correction electrode member (14) extends inside the grid (5) in FIG. FIG. 8 shows the relationship between the distortion of the electron beam on both sides and the length l of the portion where the correction electrode member (14) overlaps the third block grid (5). The experimental conditions in FIG. 8 are as follows: the interval between the three electron beams is 4.92 mm, the horizontal aperture diameter of the substantial beam passage area (12) of the fourth grid (6) is 15.0 mm, the vertical aperture diameter is 4.5 mm, and the vertical aperture is The horizontal opening diameter of the opening of the fourth grid (6) including the large-diameter portion is 20.0 mm,
The applied voltage V _f to the grid (5) is a fixed voltage of 9.0KV, the applied voltage V _g to the fourth grid (6) is 8,5kV to 9.5
Variable voltage of kV. The beam distortion is evaluated by measuring the horizontal dimension L _H and the vertical dimension L _v of the beam that has exited the second electron lens, and calculating the beam distortion (Beam Astigmatizm) k = (L _V / L _H ).
Perform by calculating × 100%. When k> 100, it becomes a vertically long beam spot, and when k <100, it becomes a horizontally long beam spot. Figure 8 from the fourth grid (6) the applied voltage V _g is to 95% of the beam distortion k at 8.8kV to 9.2KV 10 to
In order to obtain 5%, good characteristics can be obtained by setting l to 1.0 mm to 2.5 mm.

FIG. 9 shows the deflection angles of the electron beams on both sides and the correction electrode members (1).
4) is the length l of the portion overlapping the third grid (5)
The relationship is shown below. In FIG. 9, the deflection angle θ has a positive deflection angle when the two-sided electron beam is deflected away from the central electron beam. 8 and 9, a desired characteristic can be obtained by appropriately setting the length 1 of the correction electrode member (14).

Shows the shift amount [Delta] V _f and the degree of concentration deviation amount of relationship from the design value of the condenser voltage in FIG. 10. FIG. 10 shows characteristics in an embodiment of the present invention, and FIG. 10 shows characteristics in a conventional in-line type electron gun. Thus, in the embodiment, even if the focusing voltage of the main electron lens in the first electron lens, that is, the in-line type electron gun of the conventional color cathode ray tube, is changed,
It can be seen that the degree of concentration of the electron beam of the book hardly changes.

In addition, U.S. Pat.
Some are described in the specification of 4,851,741. That is, a plate-shaped correction electrode provided so as to sandwich the individual beam passage openings provided at the cathode-side bottom of the electrodes constituting the main electron lens from above and below in common, and a common opening including the plate-shaped correction electrode. The strength of the asymmetric lens formed by the provided counter electrode is changed by applying a dynamic voltage to the plate-shaped correction electrode. However, since this proposal relates to dynamic focus, the electron beam is distorted before the main electron lens. On the other hand, the present invention is to compensate for the degree of concentration without giving a distortion to each electron beam, so the proposal described in U.S. Pat.No. 4,851,741 differs from the present invention. Is clear.

Further, in the above embodiment, the BPF type electron lens is used as the focusing lens system of the main electron lens. However, the present invention relates to a unipotential type electron lens system.
cus: UPF) Needless to say, it can be applied to an electron gun or other compound electron gun. The first of the focusing lenses
Although the electrode structure of the electron lens described above is described as being decentered with respect to the electron beam on both sides, the structure of the first electron lens is not limited to this. In addition, the shape of the portion having a large vertical aperture of the substantially horizontally elongated opening portion provided on the phosphor screen side electrode of the counter electrode constituting the second electron lens is not limited to the above embodiment, and may be appropriately selected. It goes without saying that you get it.

Further, a voltage fixed to one of the converging voltages constituting the second electron lens having the concentration compensation function may be supplied by incorporating a resistor in the tube and dividing the anode voltage by a predetermined ratio.

[Effects of the Invention] As described above, according to the present invention, even if the focusing voltage deviates from the design value, the concentration of the three electron beams at a predetermined position on the phosphor screen is kept constant. It is possible to obtain an extremely practical high-resolution color cathode ray tube without deterioration of the beam spot due to the action of compensating the degree of concentration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an XZ plane (horizontal plane) of an in-line type electron gun according to an embodiment of the color cathode ray tube of the present invention, and FIG. 2 is a YZ plane (vertical plane) of the electron gun shown in FIG. 3 (a) and 3 (b) are plan views showing the shape of the opening of the first electron lens portion in FIG. 1, and FIG. 4 is the first view in FIG. 5 is a potential distribution diagram on the YZ plane (vertical plane) of the electron lens portion, FIG. 5 is a potential distribution diagram on the XZ plane (horizontal plane) of the first electron lens portion in FIG. 1, and FIG.
FIG. 7 is a diagram showing a potential distribution on the XY plane of the first electron lens portion in FIG. 1, FIG. 7 is a schematic plan view for explaining the function of the convergence correcting lens on the XZ plane of the present invention, and FIG. FIG. 9 is a characteristic diagram showing the relationship between the focused voltage of the electron gun and the beam distortion in the embodiment of the present invention. FIG. 9 is a characteristic diagram showing the relationship between the focused voltage of the electron gun and the deflection angle of the double-sided electron beam in the embodiment of the present invention. FIG. 10 is a characteristic diagram showing the relationship between the focusing voltage of the electron gun and the deviation of the degree of concentration in the embodiment of the present invention. FIG. 11 is a cross-sectional view taken along the XZ plane (horizontal plane) of the conventional in-line type electron gun. FIG. 12 is a sectional view showing an XZ plane (horizontal plane) of the conventional in-line type electron gun for concentration correction, and FIG.
FIG. 3 is a schematic plan view for explaining a relationship between an electron lens system and an object point position in the figure. (1) ... heater (2) ... cathode (3) ... first grid (4) ... second grid (5) ... third grid (6) ... fourth grid (7) ... second 5 grid (9) .... electron beam (10) ... opening (11) ... opening (14) .... correction electrode member (L ₁₀₎ ... first electron lens (L ₂₀₎ ...... second Electronic lens

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 29/48-29/68

Claims (1)

(57) [Claims] 1. A color cathode ray tube comprising at least a in-line type electron gun including a cathode for emitting three electron beams arranged in-line at the center and both sides, and a phosphor screen facing the in-line type electron gun. The electron lens system of the in-line type electron gun includes a high-voltage electrode to which a high voltage on the fluorescent screen side is applied, and a lower voltage that is lower than the high voltage and is located on the cathode side of the high-voltage electrode. A first electron lens portion, which is composed of a low-voltage electrode that focuses and concentrates the three electron beams at a predetermined position, and is applied to the low-voltage electrode on the cathode side of the first electron lens. And a second electron lens portion configured by a counter electrode having a low voltage substantially the same as the applied voltage and having an opening common to the three electron beams. Constituent oncoming electricity Of the phosphor screen side electrode, an opening which is substantially elongated in the in-line direction and has an opening diameter perpendicular to the in-line direction, and both ends of the opening in the in-line direction are larger than a substantial beam passage area; A pair of correction electrode members extending to the cathode side so as to sandwich the inline surface from the side of the opening along the inline direction forming the passage area; and the correction electrode member is a cathode of the cathode electrode of the counter electrode. The second electron lens by extending a low voltage applied to the low voltage electrode of the first electron lens and the fluorescent screen side electrode of the second electron lens to a variable voltage. A color cathode ray tube for deflecting the electron beams on both sides in an in-line direction to compensate for an excessive or insufficient degree of concentration of the three electron beams of the first electron lens.