JPS5816448A - Deflection yoke for projection type television unit - Google Patents

Abstract

PURPOSE:To simplify a correction circuit and to reduce miss convergence on a screen by arranging one or a plurality of pairs of magnetic pieces at a specific position on the screen side of a deflection yoke and at a specific position on the electron gun side in the opposite direction to the left or the right in relation to that on the screen side. CONSTITUTION:Magnetic pieces 17 are arranged on or near a vertical deflection coil constituting a deflection yoke so that the center is placed on either the left or the right side relative to the vertical center line 20 of the deflection yoke and in the opposite direction to the left or the right on the screen side and on the electron gun side, and moreover, nearly symmetrically in the up and down direction relative to the center line 21 of the horizontal direction. Thereby, horizontal trapezoid distortions or vertical bow distortions causing miss convergence on a screen can be corrected, thus a correction circuit and an auxiliary deflection yoke are not required or are simplified, and a stable picture can be available.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deflection yoke used in a projection panel television set K.

In general, a projection source television display device using a projection tube (hereinafter referred to as CRT) has a projection CAr1.
It is composed of a lens 2, a screen 4, etc. In such a projection layer television 1 device, if the projection optical axis S consisting of the projection CRT 1 and lens 2 is perpendicular to the screen 4 as shown in FIG. The image is linearly enlarged and appears on the screen 4, and if the projection CRT 1 has a rectangular shape, the image on the screen 4 will also appear as an accurate rectangle as shown in FIG. 3K. However, as shown in Figure jI2, when the projection optical axis 5 consisting of the projection CRY 1 and the lens 2 is horizontally inclined by a certain angle θ with respect to the screen 4, the image on the projection CRT l is 'Even if it is a precise rectangle, one image on the screen 4a will be l11g1 with horizontal trapezoidal distortion as shown in FIG.

9. If the screen 4b is a part of a spherical surface, as shown by the broken line in Figure #12, a vertical bow distortion 7 is applied to the vertical raster screen at the center of the screen, as shown by the broken line in Figure 6. arise.

The conventional method for correcting horizontal keystone distortion and vertical bow distortion in the center of the screen is to first distort the image on the projection CRT using a dedicated electrical circuit, and then The horizontal trapezoidal distortion and the arcuate distortion of the vertical line raster are offset.

However, the electrical circuit for correcting this distortion is not only complicated, but also has the drawback of being unstable with respect to electrical changes. In particular, as shown in Figure JII4, red (
The five primary colors of R), green (G), and actual CB) are projected at different positions, and the S primary color is mixed on the screen to create color11.
When trying to obtain an i-image, the horizontal trapezoidal distortion 6R1 vertical thin bow distortion 7R of the red image on the screen surface and the horizontal trapezoidal distortion 6B and vertical line bow distortion 7B of blue 1jif& are in opposite directions, and the normal The green Iji! K11 with i-image 5G
This results in misconvergence (color shift) of R, G, and H as shown in i51KJK.

In this case, the electrical correction circuit for correcting the above-mentioned mold becomes more complicated, and the CRTK of each of
A sub-deflection yoke 9 as shown in FIG.

As described above, the conventional method is not economical, and its adjustment is extremely difficult. In this case, electrical fluctuations cause deterioration of the image spargence and image quality, so the correction circuit is required to have a high degree of stability.

It is an object of the present invention to eliminate the above-mentioned drawbacks of the prior art, and to provide a dedicated electrical system for any or all of the misconvergence on the screen caused by horizontal keystone distortion and M-line bow distortion in the center of the screen. Correction circuit function for projection CRTI/
From K, attach C to the deflection yoke to be used.
The present invention provides a means for sufficiently correcting or reducing the misconvergence on the screen and eliminating or simplifying the electrical correction circuit.

In the present invention, the magnetic material piece is placed such that on the screen side of the deflection yoke, the center of the magnetic material piece is on either the left or right side with respect to the vertical center # of the deflection yoke, and above and below with respect to the horizontal center line. One or more pairs are provided at positions that are substantially symmetrical in the direction, and on the electron gun side of the deflection yoke, the center of the magnetic piece is on either the left or right side with respect to the vertical center mK of the deflection yoke. A pair or a plurality of pairs are provided on the opposite side in the left-right direction to the magnetic material pieces arranged on the ri surface ill, and at positions that are approximately symmetrical in the vertical direction with respect to the horizontal center f@. .

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a deflection yoke for a projection type television set according to the present invention will be described below.

As mentioned above, the horizontal keystone distortion on the screen, and Ii
! In order to correct the bow distortion of the vertical line raster at the center of the ii surface, taking into account that the image will be reversed by the lens, in the case of the projection conditions shown in Figure 4, a screen is placed on the fluorescent surface of the CRT' in advance. It is necessary to form an image having a distortion in the opposite direction to the distortion that occurs in order to offset the projection distortion on the screen.

Therefore, as shown in Figure 4, a method for forming horizontal trapezoidal distortion and vertical line bow distortion in the center of the screen on the fluorescent surface of a projection CRT is as shown in Figure 4. A blue CRT 1B will be described as an apparatus for projecting a CRT IB from the left side.

In order to obtain a rectangular raster on the projection screen surface, the directions of the horizontal trapezoidal distortion 12 and the vertical arcuate distortion 1s at the center of the blue projection CRT IB, which must be formed on the fluorescent surface of the blue projection CRT IB, are shown in Figure II7. As shown. jI8 figure (
α) KThe external appearance of a conventional deflection yoke and the front view of the vertical deflection coil that constitutes it are shown in lsa diagram (A), and Fig. 9 (4
1) K The appearance of the deflection yoke according to the present invention is shown in FIG. 9(ch), which is a front view of the vertical deflection coil portion of the deflection yoke shown in FIG. 9(g) according to the present invention. Figure 7748 (Todoroki)
The shape of the vertical deflection magnetic field in the case of , when viewed in a cross section perpendicular to the central axis of the deflection yoke, is configured as shown in FIG. 10 (1) K, and the magnetic force produced by the vertical deflection coil! 118
The shape is symmetrical in the left-right direction with respect to the vertical center 920IC. Therefore, the raster shape formed on the CRT fluorescent surface is as shown in Figure N10 (A) K.
The screen is symmetrical in the horizontal direction with respect to the vertical center 1120 on the CRT fluorescent surface.

On the other hand, the deflection yoke according to the present invention is as follows.

A magnetic piece 17 is placed on or near the vertical deflection coil constituting this, and its center is the vertical center 9 of the deflection yoke.
Regarding 20, the left corner is either 1lKlii in the right direction.
The i-plane side and the electron gun side are arranged horizontally in opposite directions, and are arranged so as to be substantially symmetrical in the vertical direction with respect to the horizontal center 1121K.

Next, the raster shape on the CRT fluorescent surface when the magnetic pieces are arranged in this manner will be explained.

Regarding the deflection yoke shown in FIGS. 519(g) and (A)K, consider the shape of the magnetic force m18 at a cross section INK perpendicular to its central axis.

The shape of the magnetic field inside the deflection yoke shown in Figure ls9, when viewed in cross section from the screen side and the electron gun side, is the shape of the magnetic field shown in Figure 10(a) with the effect of the magnetic piece being added to the shape of the magnetic field shown in Figure 10(a).
g) The result will be as shown in (A). In addition, j1
Figure 11(g) shows the shape of the vertical deflection magnetic field on the ii1 side.
FIG. 1(j) shows the shape of the vertical deflection magnetic field on the electron gun side, and is a cross-sectional view in a direction perpendicular to the central axis of the deflection yoke, as seen from the # side. Furthermore, when a magnetic piece is placed in the magnetic field created by the vertical deflection coil, the strength of the magnetic field that contributes to deflection is weakened by the cough fiber piece.

Now, the electron beam reaching the corner of the i# plane of the raster formed on the CRT fluorescent surface is deflected both horizontally and vertically. Directional deflection magnet JIF of the deflection yoke related to the present invention K
From K, the strength of the vertical deflection of the electron beam reaching the left corner of the - plane and the electron beam reaching the right corner of the screen is determined by the vertical deflection strength of the cross section perpendicular to the center axis of the deflection yoke. Let's consider the deflection magnetic field.

In the vertical deflection magnetic field on the side closer to the electron gun, the position of the electron beam reaching the left coach part of the screen is also determined.

Since the position of the electron beam that reaches the right corner of the screen is also near the center axis of the deflection yoke, the strength of the vertical deflection of the electron beam that reaches the left corner of the However, the difference is very small.

Next, considering the strength of the vertical deflection magnetic field shown in Figure 811, the strength of the magnetic field contributing to vertical deflection is the strength on the left side and the strength on the right side with respect to the vertical center 920. As it passes toward the side of the screen, it reverses,
The strength on the left side will be stronger than the strength on the right side. and,
As the electron beam moves toward the screen, the position of the electron beam moves away from the central axis of the deflection coil.
In any vertical deflection magnetic field close to iirm, the strength of the vertical deflection applied to the electron beam reaching the left corner of the screen is greater than the strength of the vertical deflection applied to the electron beam reaching the right corner of the screen. As the value becomes larger, the difference also becomes larger, so that the effect of forming horizontal trapezoidal distortion on the CRT fluorescent surface can be obtained. On the other hand, among the rasters formed on the CRT fluorescent surface, the electron beam reaching the 11ii-center vertical part is deflected only in the vertical direction, so the vertical deflection magnetic field involved in the device @IIK deflects the electron beam. The direction 19 of this deflecting force is shown in Fig. 11 (g
) and (A), the effect of the deflection magnetic field shape in the electron gun side cross section and the effect of the deflection magnetic field shape in the one-plane noble cross section tend to cancel each other out.

Therefore, the raster shape appearing on the CRT fluorescent surface is U, j112CG'j KMii1m as shown in K.
l Regarding the vertical horizontal line twister, the left side has a horizontal trapezoidal distortion that is wider than the right side, resulting in 1iiillr. on the other hand,
Regarding the vertical line raster at the center of the screen, the center position of the magnetic piece placed on the electron gun side and the center position of the magnetic piece placed on the 1m plane 111 are the vertical center I! When the IK is approximately symmetrical in the left and right direction,
Since the effect of the direct deflection magnetic field shape and the effect of the straight deflection magnetic field shape in the #vfJllfr plane are in a relationship that almost cancels each other out, a # plane without vertical bow distortion can be obtained. In addition, the relationship between the center position of the magnetic material piece placed on the electron gun side and the center position of the magnetic material piece placed at tmm* was adjusted so that the overall strength of the vertical deflection magnetic field was biased to the right. As shown in 812611 (A) K, the horizontal trapezoidal distortion due to the K11gm upper and lower horizontal can raster is the same as in 1s12 (a), but the vertical line rask in the center of one screen has a vertical-arcuous distortion curved to the right 11. A raster with 15 can be obtained. In this way, by using the deflection yoke according to the present invention shown in FIG. 9, the image shown in FIG.
Both horizontal trapezoidal distortion and arcuate distortion shown in can be simultaneously created in a desired direction. Further, in this embodiment, one pair of magnetic pieces are used on each of the screen side and the electron gun side of the deflection yoke in the vertical direction with respect to the horizontal center 1121, but a plurality of pairs may be provided.

As a result, on the projection screen surface of a projection television device, horizontal trapezoidal distortion occurs due to the projection optical axis being tilted with respect to the screen, and horizontal trapezoidal distortion occurs when the screen is a part of one surface. Both vertical line bow distortions in the center are canceled simultaneously, and Fig. 5 and g5i
Since it is possible to obtain a rectangular raster 5 as shown in FIG. 1, the misconvergence on the screen caused by the above distortion can be sufficiently corrected or reduced.

As another ** example, as shown in Figure 31115 **
So that the center of gravity is reversed in the horizontal direction between the screen side and the electron gun side.
A deflection yoke for a 11f projection system is constructed by using a vertical deflection coil wound obliquely to the center axis 22 of the deflection yoke (the magnetic piece 17 is removed in Fig. 15). (Undecided) If the present invention is applied, greater effects can be obtained.

This is the reason for the vertical thickness unevenness shown in Figure 5 (@) and (A) (Figure 1 with magnetic piece 17 removed).

Figure 11 C@), (A) K is rounded with a vertical deflection magnetic field shown in advance, and furthermore, J111
If magnetic pieces are provided as shown in Figure 5 (α) and (A)K,
The magnetic piece has the effect of weakening the strength of the magnetic field that contributes to the deflection of this part, so it has the effect of essentially increasing the angle between the center ring of the deflection yoke and the winding direction of the wire wound around the core. can get.

Therefore, it is possible to increase the effect of reversing the shape of the vertical deflection magnetic field on the screen side and the electron gun side of the deflection yoke in the horizontal direction with respect to the center 1 mK of the deflection yoke in the -perpendicular direction. This is an effective method because it can further enhance the misconvergence correction ability.

Incidentally, an example of actual use of the deflection yoke related to the above device #4K is shown in FIG. 14(g). The first layer is placed on the CRT fluorescent surface.
By creating raster distortion as shown in Figure 4 (K) on the CRT phosphor surface, it becomes difficult to obtain a regular rectangular raster on the screen. The above misconvergence can be corrected and saved.

The present invention is configured as described above, and it is necessary to sufficiently correct all of the horizontal keystone distortion and vertical-bow distortion at the center of the screen, which are the causes of misconvergence on the screen, or It is possible to obtain an economical and stable wR image by eliminating or simplifying the correction path and sub-deflection yoke, rather than Jin and K, which reduce the amount of correction. It is.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams showing the relationship between the projection screen and the imager, and 5th WJ shows the horizontal trapezoidal distortion of the projection plane on the screen and the vertical line bow distortion in the center of the screen. , Recommendation 4 is a schematic diagram showing a color projection device, and s#iA is a male by the color projection device of FIG. 4;
@6#A is a block diagram showing the configuration of a conventional projection CRT, a deflection yoke, and a sub-deflection yoke. Figure 1s7 is a pattern diagram showing the configuration of a conventional projection CRT, a deflection yoke, and a sub-deflection yoke. Figure 8 is a pattern diagram showing the distortion required to be formed on the fluorescent surface of the true color projection CRT IB shown in Figure KJIEJ (81 is a perspective view of a conventional deflection yoke; 88@(J)a) , Figure (6) is a nine-dimensional rfJ diagram viewed from the first side of the vertical deflection coil constituting this, and Figure (6) is a flange diagram of the deflection yoke according to the present invention, and Figure 9 (b) is:
FIG. 10 is a front view of the vertical deflection coil portion showing the arrangement of the magnetic material pieces according to the present invention. This is a cross-sectional view showing the shape of the magnetic field lines at rEK.
01fi (j) is CR by a conventional vertical deflection magnetic field.
FIG. 11, a pattern diagram showing the rask shape formed on the fluorescent surface of I', shows the shape of the rask in the cross section perpendicular to the center of the deflection yoke for the vertical deflection magnetic field constructed by the invention. In the cross-sectional views shown, Figure 11 (6) shows the − side, and Figure 11 (h) shows the side of the electron gun.
Figure 12(g), C4) is a pattern 11J showing the raster distortion formed on the fluorescent surface with Cj < r by the vertical deflection magnetic field of the deflection yoke involved in one EAK device.
, 815114 are diagrams showing the main parts of another actual example related to the present invention. Figure 1I15 (1) is a front view of the superimposed deflection coil part, and Figure 1I115 (the illusion is the inside of the core of the vertical deflection coil part). This is a view of the trowel plane seen from the side.) Figure 1114 (a
)teeth. Due to the deflection yoke involved in zero-emission Ij11, the positive WJ diagram of each vertical deflection coil part when used in the color projection device shown in Figure 84, and Figure 14 (4) are for each CRT.
FIG. 2 is a pattern diagram showing a rask shape on a fluorescent surface. 10: Electron gun 11: Electron beam 17: A-type body yi15 Figure 4. Aimer 5th figure 6 figure $17 Broom 3 times (a)
(b) 5th 9th Ce1)
<B no. to figure (a an)
(b) Grass 14 @

Claims (1)

[Claims] t. In a deflection yoke attached to the projection tube of a projection type television set that projects the reproduced image on the fluorescent surface of the projection tube from an oblique direction to the projection screen surface, a magnetic piece is deflected. On the WI surface side of the mold, the center of the magnetic material piece is on either side of the left or right side with respect to the vertical center line of the deflection ring, and 11 is located on the horizontal center 41.
1, one or more pairs are provided at positions that are approximately symmetrical in the vertical direction, and on the electron gun side of the deflection yoke, the center of the magnetic material piece is aligned with the center of the deflection yoke in the straight direction 11iIK11
1 on either the left or right side of the screen
A projection type characterized by -rt or a plurality of pairs of magnetic material pieces disposed on sides opposite to each other in the left-right direction and at positions substantially symmetrical in the vertical direction with respect to the center fliKT/14 in the horizontal direction. Deflection wire for television equipment.