JPH02207439A - Inline type color picture tube - Google Patents

Abstract

PURPOSE:To prevent convergence error by making a quadruple-pole magnet of a static convergence device and a quardruple-pole agent for beam rotation adjustment of the permanent agents having the respective temperature demagnetizing coefficients while specifying a difference between the temperature demagnetizing coefficients of these magnets. CONSTITUTION:A quardruple-pole magnet 25a of a static convergence device to be mounted for converging a plurality of beams emitted from an electron gun 2 on one point on the screen central part and a quardruple-pole magnet 28 for beam rotation adjustment are made of permanent magnets having the temperature demagnetizing coefficients above 0.05% deg.C while making a difference between the temperature demagnetizing coefficients less than 0.02%. Thereby, demagnetization of each magnet accompanying temperature rise is suppressed while reducing a relative difference of demagnetization. Accordingly, convergence error due to temperature rise can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an in-line color picture tube, and more particularly to an in-line color picture tube equipped with a beam rotation adjustment magnet.

(Prior Art) In general, an in-line color picture tube, as shown in FIG. Electron gun (2) that emits three electron beams arranged in a row consisting of
is arranged, and the three electron beams emitted from this electron gun (2) are deflected in horizontal and vertical directions by a horizontal deflection magnetic field and a vertical deflection magnetic field formed by a deflection yoke (3) attached to the outside of the envelope. By scanning a phosphor screen (4) consisting of three color phosphor layers, a color image is displayed on the phosphor screen (4). In particular, in the self-convergence type in-line color picture tube that self-converges the three electron beams, the deflection yoke has a horizontal deflection magnetic field of a vinch type and a vertical deflection magnetic field of a barrel type.

In order to correctly display an image on the screen in such a color picture tube, it is necessary to concentrate the three electron beams emitted from the electron gun (2) onto one point at the center of the phosphor screen (4). It is.

For this purpose, the neck (1) where the electron gun (2) is installed is
) A set of two ring-shaped 4-pole magnets on the outside (6a)
Similarly, a static convergence device (7) consisting of a set of two six-pole magnets (6b) and a purity magnet (8) consisting of a set of two ring-shaped bipolar magnets are attached.

Normally, a color picture tube is equipped with a static convergence device (7) and a purity magnet (8).
The electron beam is adjusted to focus on one point on the center of the phosphor screen (5).

However, if the alignment axis of the three electron beams, which originally pass on a horizontal plane that includes the tube axis, is rotated around the tube axis due to assembly errors in the electron gun or color picture tube, the image on the screen may appear as shown in Figure 6. A pair of side beam patterns (IOB),
(IOR) becomes arcuate and does not match at both ends of the screen horizontal axis (X axis). For example, if three electron beams are incident on the deflection magnetic field of the deflection yoke with their array axes rotated clockwise around the tube axis, then when they are deflected to the left in the horizontal direction,
As shown in Fig. 7(a), the horizontal deflection magnetic field (11) of the deflection yoke causes the side beam (12B), which is located above the horizontal axis, of the pair of side beams (12B) and (12R) to ) receives a force in the direction of arrow (13a) and reaches the phosphor screen below the horizontal axis, and the side beam (12R) located below the horizontal axis moves as shown in arrow (14a) When it reaches the phosphor screen due to the force in the direction, it is above the horizontal axis, and when it is deflected to the right side in the horizontal direction, it is in the direction of the arrows (13b) and (14b), respectively, as shown in (b). This is because they receive the power of and become the same.

In order to correct the arcuate patterns (IOB) and (IOR) (misconvergence patterns) caused by the rotation of the electron beam array axis, as shown in Fig. 5, the rear deflection yoke (4) is Some have a set of two ring-shaped quadrupole magnets (15) for beam rotation adjustment attached to the ends.

When the 4-pole magnet (15) for beam rotation adjustment is attached in this way, in combination with the 4-pole magnet (6a) of the static convergence device (7), the 3 electron beams are concentrated on the horizontal axis of the screen and the arcuate shape Tubaturn (IOB)
), (IOR) can be corrected, and the 6-pole magnet (
6b) and the purity magnet (8), it is possible to concentrate on one point on the center of the screen. For example, as shown in FIG. 7, a pair of side beams (12B) and (12
R), static convergence device (7)
The quadrupole magnet (6a) lowers the left side beam (12B) and raises the right side beam (12R), making the alignment axis of the three electron beams incident on the deflection magnetic field horizontal, thereby creating an arcuate shape. pattern (IOB), (
IQR) is corrected. However, in this state, the patterns of the pair of side beams (12B) and (12R) are vertically shifted, so next, the left side beam (12B) is
) and lower the right side beam (12R), the three electron beams are concentrated in a straight line on the horizontal axis of the screen, resulting in a pair of side beams (12B) and (12R).
can be matched.

(Problem to be Solved by the Invention) As mentioned above, in order to concentrate the three electron beams passing on the horizontal plane including the tube axis, in addition to a static convergence device and a purity magnet, the rear end of the deflection yoke There is a color picture tube equipped with a quadrupole magnet for beam rotation adjustment.

However, conventional magnets are so-called plastic magnets made by hardening barium ferrite magnetic powder with resin, and have a large demagnetization coefficient with respect to temperature of 0.2%/℃.
Concentration errors due to temperature rise during color picture tube operation are large, and color shift occurs across the entire screen, especially in high-definition color picture tubes such as color display tubes.

This invention was made in order to solve the above-mentioned problems, and its purpose is to reduce the concentration deviation due to temperature rise during operation of the color picture tube, and to provide an in-line color picture tube that does not cause color shift. do.

[Structure of the Invention] (Means for Solving the Problems) A static convergence system having a quadrupole magnet for concentrating a plurality of beams emitted from an electron gun and arranged in a row and passing on the same plane onto one point on a phosphor screen. and a beam rotation adjustment device that is installed between the static convergence device and a deflection yoke that deflects the plurality of beams emitted from the electron gun, and that corrects rotational deviation of the alignment axis of the plurality of beams around the tube axis. In an in-line color picture tube equipped with a quadrupole magnet, the quadrupole magnet of the static convergence device and the quadrupole magnet for beam rotation adjustment are each permanent magnets with a temperature demagnetization coefficient of 0.05%/°C or less. , and the difference in temperature demagnetization coefficient of these magnets is 0.02%.
/℃ or less.

(Function) As mentioned above, the 4-pole magnet of the static convergence device and the 4-pole magnet for beam rotation adjustment are each permanent magnets with a temperature demagnetization coefficient of 0.05%/°C or less, and the pair of these magnets is The difference in temperature demagnetization coefficient is 0.
When the temperature is set to 02%/°C or less, the reduction in magnetic force of each magnet due to temperature rise can be suppressed, and the relative difference in magnetic force reduction is also small, and as a result, the concentration shift due to temperature rise can be reduced.

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 1 shows an in-line color picture tube which is an embodiment of the present invention. This color picture tube has an envelope consisting of a panel (20) and a funnel (21) joined to the body, and on the inner surface of the panel (20) is a three-color phosphor layer that emits blue, green, and red light. A panel (2) is provided opposite to the phosphor screen (4).
0) A shadow mask (22) in which a large number of electron beam passage holes are formed is attached inside. Further, an electron gun (2) that emits three electron beams arranged in a row consisting of a center beam and a pair of side beams passing on a horizontal plane including the tube axis is arranged in the neck (1) of the funnel (21). .

Also, the neck (1) and cone part (
A deflection yoke (3) is attached to the outside of the boundary between the deflection yoke (23) and the deflection yoke (3). This deflection yoke (3) includes a horizontal deflection coil that forms a binction type horizontal deflection magnetic field and a vertical deflection coil that forms a barrel type vertical deflection magnetic field.
It is configured to self-focus three electron beams emitted from the electron beam. Further, on the outside of the neck (1), a set of two ring-shaped quadrupole magnets (25a) and a six
A static convergence device (2B) consisting of a polar magnet (25b) and a set of two ring-shaped
A purity magnet (27) consisting of a polar magnet is furthermore attached to the rear end of the deflection yoke (3). ) is installed.

Moreover, in the color picture tube of this example, the hexapole magnet (25b) of the static convergence device (2B)
and brility magnet (27) are plastic magnets made of barium ferrite magnetic powder hardened with resin as in the past, but static convergence device (27)
The quadrupole magnet (25a) in B) is Fe-Cr-C with a temperature demagnetization coefficient of 0.03%/°C.

The beam rotation adjustment magnet (2
Regarding 8), 5I with a temperature demagnetization coefficient of 0.02%/°C
Consists of l-Co material permanent magnet.

The four-pole magnet (25a) of the static convergence device (26) generates magnetic flux shown by the broken line (30) in FIG. (12B), (12
exerts an opposite force on R). The magnetic force becomes maximum when the same poles of a set of two magnets (25a) overlap, and becomes zero when different poles overlap. Therefore, by rotating and adjusting these two quadrupole magnets (25a), the pair of side beams (12B), (1
2R) can be concentrated at one point on the phosphor screen. In addition, as shown in (b), the hexapole magnet (25b) of the static convergence device (2B)
generates the magnetic flux shown by the broken line (32), and the arrow (33a)
, (33b), a pair of side beams (1
2B) exerts a force in the same direction on (L2R). The direction of this magnetic force is reversed by rotating this magnet (25b) and reversing its polarity. Therefore, by adjusting the rotation of this set of two six-pole magnets (25b), the pair of side beams (12B), (12R) and center beam (12G) concentrated by the four-pole magnet (25a) can be adjusted. It can be concentrated at one point on the phosphor screen.

In addition, as shown in FIG. 2(e), the purity magnet (27) generates magnetic flux shown by the broken line (34), and the pair of side beams ( 12B), (12R) and center beam (12
G) exerts a force in the same direction. Therefore, by rotating and adjusting the set of two utility magnets (27), it is possible to adjust the landing of the three electron beams on the three-color phosphor layer, that is, the color purity.

Furthermore, as shown in FIG. 3, the beam rotation adjustment magnet (28) consisting of a quadrupole magnet
As shown in the above static convergence device (2
It generates the same magnetic flux as the quadrupole magnet (25a) in 6) and exerts a similar force on the pair of side beams (12B) and (12R).

Static convergence adjustment using each of these magnets is actually carried out by first focusing the pair of side beams (12B) and (12R) on the phosphor screen using the quadrupole magnet (25a) of the static convergence device (2B). Adjust to. In an optimally designed color picture tube, the pair of side beams match the center beam at this point, but if the side beams and the center beam do not match, the rotation of the hexapole magnet (25b) of the static convergence device (2B) Adjust them to match.

Normally, the three electron beams enter the deflection magnetic field through a horizontal plane that includes the tube axis, but due to assembly errors in the color picture tube, the alignment axis of the three electron beams enters the deflection magnetic field with rotational deviation around the tube axis. Assume that the arcuate misconvergence pattern shown in FIG. 6 occurs. For example, if the deviation of the pair of side beam patterns (IOB) and (IOR) in FIG. 6 is 0.3 degrees at both ends of the screen horizontal axis, in this case, the side beam (12B) upward and the side beam (12R) downward about three fins, then use the quadrupole magnet (25a) of the static convergence device (26) to
Side beam (12B) downward, side beam (12B)
R) is moved upward and the adjustment by the beam rotation adjustment magnet (28) and the quadrupole magnet (25a) is repeated to match the patterns of the pair of side beams (12B) and (12R).

Incidentally, color picture tubes generally experience a temperature rise during operation. When the temperature reaches about 50℃, even if the concentration of the three electron beams is adjusted as described above, because conventional color picture tubes use barium ferrite plastic magnets (temperature demagnetization coefficient 0 .2%/℃), the magnetic force decreased by about 10%, the pattern of a pair of side beams shifted by 0.2 to OJmm at both ends of the horizontal axis of the screen, and color shift occurred across the screen due to misconvergence. In this color picture tube, the quadrupole magnet (25a) of the static convergence device (26) is made of Pe-Cr-C.
On the other hand, the beam rotation adjustment magnet (28) is made of Sm-C.

Each material has a temperature demagnetization coefficient of 0.03%.
/°C, and as small as 0.02%/°C, it was possible to eliminate the pattern misalignment of the pair of side beams at both ends of the horizontal axis of the screen.

That is, even if a 0.3 mm deviation in the pattern of the pair of side beams at both ends of the horizontal axis of the screen is corrected by the 4-pole magnet of the static convergence device and the beam rotation adjustment magnet, the demagnetization coefficient with respect to temperature remains 0.
In a conventional color picture tube, which has a temperature of 2%/℃, the temperature is 50℃.
As shown in FIG. 4(a), a pair of side beams (12B).

(121?) is shifted by 0.3 degrees vertically at the center of the screen, as shown by the interval d. On the other hand, if the temperature demagnetization coefficient of the 4-pole magnet in the static convergence device is 0.02%/°C, and the temperature demagnetization coefficient of the beam rotation adjustment magnet is 0.2%/°C, then ), a pair of side beams (12B).

(12R) is shifted by 0.25 am left and right. In addition, the temperature demagnetization coefficients of the four-pole magnet of the static convergence device and the magnet for beam rotation adjustment are each 0.05%/°C or less, and the difference between them is 0°03%/°C.
Even if it is below ℃, as shown in (C), the -pair of side beams (12B) and (12R) are vertically 0.08
This will cause a discrepancy in performance. However, if the temperature demagnetization coefficients of the four-pole magnet of the static convergence device and the beam rotation adjustment magnet are each 0°05%/°C or less, and the difference between them is 0.02%/°C or less, the same (
As shown in d), it is possible to achieve a state without any deformation.

In the above embodiment, the four-pole magnet of the static convergence device is made of Fe-Cr-Co material, while the beam rotation adjustment magnet is made of 5i-C.

These materials have a temperature demagnetization coefficient of 0.05.
%/℃ or less, the difference in demagnetization coefficient with respect to temperature is 0.02%/℃
The following is sufficient, and both are Pe-Cr-Co material or 5
It may also be made of s-Co material.

Furthermore, in the above embodiment, the magnets other than the four-pole magnet of the static convergence device and the beam rotation adjustment magnet were barium ferrite plastic magnets, but each of these magnets was re-C
A permanent magnet made of r-Co material or Sm-Co material may also be used.

[Effects of the invention] Quadrupole magnet of a static convergence device installed to concentrate multiple beams emitted from an electron gun of an in-line color picture tube to a single point on the center of the screen and quadrupole for adjusting beam rotation. Each magnet is a permanent magnet with a demagnetization coefficient relative to temperature of 0.05%/°C or less, and the difference in the demagnetization coefficient relative to temperature of these magnets is 0.02%/°C.
By setting the following, it is possible to suppress the decrease in magnetic force of each magnet due to temperature rise, and also to reduce the relative difference in magnetic force decrease.As a result, the concentration shift due to temperature rise can be reduced and color shift can be prevented. be able to.

[Brief explanation of the drawing]

1 to 4 are detailed explanatory diagrams of the present invention, with FIG. 1 showing the configuration of an in-line color picture tube as an embodiment thereof, and FIG. 2(a) showing its static convergence device. (b) is a diagram for explaining the action of the 6-pole magnet of the static convergence device, (C) is a diagram explaining the action of the purity magnet, The figure is a diagram for explaining the action of the 4-pole magnet for beam rotation adjustment.
Figures (a) to (d) show the deviation of a pair of side beams at the center of the screen when the temperature demagnetization coefficients of the 4-pole magnet of the static convergence device and the 4-pole magnet for beam rotation adjustment are changed, respectively. Figure 5 is a diagram showing the main part configuration of a conventional in-line color picture tube, and Figure 6 is a pattern of a pair of side beams that occurs when the arrangement axes of the three electron beams are rotationally misaligned around the tube axis. Figures 7(a) and 7(b), which show the deviation, are the Vinctusion horizontal deflection magnetic field when deflecting a pair of side beams that are rotationally misaligned around the tube axis to the left and right in the horizontal direction, respectively. It is a figure for explaining the effect|action of this. 2...Electron gun 3...Deflection yoke 4...
- Phosphor screens 12B, 12R...a pair of side beams 12G...
Center beam 25a... 4-pole magnet 25b of static ζ convergence device... 6-pole magnet 26 of static convergence device... Static convergence device 27...
・Pullity magnet 28... 4-pole magnet for beam rotation adjustment Representative Patent attorney Norihiro Ogo Husband: Daf, Sufrin Diagram Diagram Diagram Atsushi

Claims (1)

[Claims] A static device having an electron gun that emits a plurality of beams arranged in a row passing on the same plane, and a quadrupole magnet for concentrating the plurality of beams emitted from the electron gun onto one point on a phosphor screen. - A beam rotation device installed between a convergence device and a deflection yoke that deflects the plurality of beams emitted from the electron gun and the static convergence device, and corrects rotational deviation of the alignment axis of the plurality of beams around the tube axis. a 4-pole magnet for adjustment, and each of the 4-pole magnet of the static convergence device and the 4-pole magnet for beam rotation adjustment is a permanent magnet with a demagnetization coefficient relative to temperature of 0.05%/°C or less, and The difference in the magnet's temperature demagnetization coefficient is 0.0.
An in-line color picture tube characterized by a temperature of 2%/℃ or less.