JP2000100343A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube that is not conspicuous in brightness change or color difference which is caused by swinging of an aperture grill strip piece without using a damper wire. SOLUTION: This color picture tube is provided with a scan means for horizontally and vertically scanning an electron beam emitted from an electron gun, and a color selecting electrode assembly 71 that has an aperture grill 10 for selecting color, so that the electron beam scanned by this scan means irradiates a phosphor with a given color of a phosphor screen and a frame 8 for developing and supporting this aperture grill and does not have any damper wire for restraining vibration of the aperture grill between the aperture grill and the frame. High contrast resonance frequency ωc where luminance change or color difference of an image which tends to be conspicuous, when the aperture grill resonates is determined relating to vertical scan frequency of the color picture tube, and resonance frequency of the aperture grill is set displaced from ω c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube using an aperture grill as a color selection electrode, and more particularly to a color picture tube using a damper wire for suppressing the vibration of the aperture grill strip due to an external impact or the like. The present invention relates to a color picture tube in which a change in luminance and a color shift due to a fluctuation of an aperture grille strip are made inconspicuous.

[0002]

2. Description of the Related Art FIG. 8 is a plan view showing a cross section of a part of a conventional color picture tube. In the drawing, reference numeral 1 denotes a panel constituting an envelope of a color picture tube, 2 denotes a funnel which constitutes an envelope of the color picture tube together with the panel 1, and 3 denotes a panel in which red, blue and green phosphors are arranged in order on the inner surface of the panel. The arranged phosphor screens, 4 are an electron gun, 5 is an electron beam emitted from the electron gun 4, and 6 is a deflection yoke for electromagnetically deflecting the electron beam 5. Reference numeral 7 denotes a color selection electrode assembly, which uses an aperture grill 10 having a large number of slit-shaped openings as color selection electrodes, and attaches the aperture grill 10 to a frame 8.
It was expanded and supported by. Since the color selection electrode assembly 7 uses the aperture grill 10 as a color selection electrode, it is referred to as a shadow grill to distinguish it from a general shadow mask. Reference numeral 21 denotes a pin provided on the panel 1, and reference numeral 15 denotes a leaf spring fixed to the frame 8. The shadow grill 7 is supported by the panel 1 by engaging holes of the leaf spring 15 with the pins 21.

FIGS. 9A and 9B are perspective views showing the structure of a conventional shadow grill 7, in which FIG. 9A shows the entire structure, and FIG. 9B shows only the frame 8. The frame 8 is made of a steel material such as SUS, for example, and includes an H member 8a and a V member 8b as shown in FIG. The aperture grill 10 has a number of slit-shaped openings 11 arranged in order on rimmed steel having a thickness of 0.1 mm. Accordingly, since the tape-shaped strips 9 are formed between the slit-shaped openings 11, the countless slit-shaped openings 11 and the tape-shaped strips 9 are alternately arranged. . The aperture grill 10 is fixed to the frame 8 by welding in an expanded state and held. Reference numeral 12 denotes a damper wire made of a tungsten wire having a diameter of 25 μm, which is in contact with the aperture grille 10 and suppresses the swinging of the aperture grille 10 due to external vibration or the like. The damper wire 12 has a structure in which the aperture grill 10 is pressed by a spring action of a damper spring 13 welded to the frame 8 and the swing of the aperture grill 10 is suppressed by using a frictional force. In addition, FIG.
The example which provided two damper wires 12 in the direction orthogonal to the longitudinal direction of the strip 9 of the aperture grill 10 is shown.

Next, the operation will be described. The inside of the color picture tube is maintained in a high vacuum by an envelope constituted by a panel 1 and a funnel 2, and an electron beam 5 emitted from an electron gun 4 is formed on the inner surface of the panel 1 to generate a high voltage. The phosphor screen 3 emits light by colliding with the applied phosphor screen 3. At the same time, the electron beam 5 is deflected right and left and up and down by a horizontal and vertical deflection magnetic field having a horizontal and vertical frequency of 30 KHz and 60 Hz generated by the deflection yoke 6, and an image called a raster is formed on the surface of the phosphor screen 3. Form a display area. The distribution of the red, blue, and green light emission intensities of the phosphor screen 3 according to the amount of the electron beam 5 in the image display area is recognized as an image by observing from the outer surface of the panel 1. The aperture grill 10 of the shadow grill 7 has an infinite number of slit-shaped openings 11 arranged in order, and the electron beam 5 passes through these holes to accurately select a color. The red, blue, and green phosphor stripes are projected at predetermined positions. As described above, since the color selection of the shadow grill type color picture tube is performed geometrically, it is necessary that the panel 1, the electron gun 4, and the shadow grill 7 always maintain a predetermined positional relationship accurately.

Since the aperture grill 10 has a large number of slit-shaped openings 11 arranged in order, the mechanical strength of the aperture grill 10 is large.
It will be maintained in. Therefore, although the frame 8 is in the extended state, its positional accuracy is unstable. In particular, they tend to be weak against vibration and impact. As a countermeasure, a damper wire 12 is provided. The damper wire 12 is attached by a damper spring 13 before or after the phosphor screen forming process. The attached state is a state in which the damper wire 12 presses the aperture grille strip 9 from above by the spring action of the damper spring 13 to provide contact resistance.

Here, the vibration characteristics in the shadow grill system will be described. Since the color picture tube is constructed using various parts, the shadow grill 7, the electron gun 4,
The deflection yoke 6 and the like resonate due to vibration energy from outside the color picture tube. This resonance phenomenon causes unsatisfactory images and reliability problems. The deflection yoke 6, which is an external component, can be excluded here because its countermeasure is relatively easy. Also, the electron gun 4 can be excluded here because it is a special case.

[0007] In the case of a picture tube, it is special to use it under vibration such as for an aircraft or a vehicle, and it is generally used in a state where the picture receiver is stationary. Therefore, in the past, the problem of vibration was mainly related to the transportation of products. Recently, TV receivers have become larger and vibration of speakers provided in the receiver has become a problem.
Similar problems have arisen because many monitors have speakers. In addition, it is inevitable to provide multimedia with a speaker.
Therefore, the specification of the vibration test is from extremely low to 20KH.
A sweep test up to about z is common. In addition, it is needless to say that vibration conditions for transportation, which have been conventionally considered, for example, 1000 rpm, amplitude 2 mm, and 30 minutes must be satisfied. Also, as a transport characteristic, for example, an impact resistance of 25 G is a general test condition. Furthermore, in a hammer test in which the panel is hit from the outside during the operation of the picture tube to test the influence of the vibration, the frequency component of the vibration is usually set to 400 Hz or less. This vibration condition is surprisingly severe.

Further, the vibration characteristics of the color picture tube will be described. The vibrations and shocks during transportation described above and the shocks during operation contribute as external vibration energy. This energy propagates as follows. Vibration source → Cabinet → Picture tube mounting ear → Panel 1 →
Panel pin 21 → Mask suspension spring 15 → Frame 8 → Aperture grille strip 9 As a result of the transmission of vibration along this path, the following is sensed by the human eye. That is, the brightness and chromaticity of the three primary colors of the image change due to the vibration of the aperture grille strip 9 and are perceived by human eyes as shaking of the image. In other words, shadow grill 7
Is perceived as a defect in the image by human eyes according to the vibration characteristics of the image.

[0009]

The conventional color picture tube is constructed as described above, and the biggest problem with the color selection electrode of the shadow grill type is that the aperture grill 10 has the following problems.
This is an aggregate of elongated metal strips extending from the upper side to the lower side of the rectangular screen structure. By design, this elongated metal strip 9 is fixed to a strong frame 8,
It is in an extended state. Therefore, there is no particular problem when the color picture tube is mechanically placed in a static state, but when vibration or impact is applied, the aperture grill 1 is not affected.
This causes the problem that 0 fluctuates. Even in this case, since a design is provided with a margin in order to absorb variations in assembling the panel 1, the electron gun 4, and the shadow grill 7, a problem occurs if the margin is sufficient. do not do. However, a problem of color misregistration occurs when the luminance changes or is extremely severe. In order to solve this, the aperture grill 10 is pressed by the damper wire 12 to suppress the vibration.

However, upon careful observation of the above-mentioned conventional countermeasures, it has been found that there are basically the following problems.
It is considered that the tension can be applied to the damper wire 12 by the spring action of the damper spring 13, and the amplitude can be finally suppressed by pressing the aperture grille strip 9 by the tensioned damper wire 12. Was. However, in fact, this damper wire 1
It was found that 2 had an adverse effect. That is,
It has been found that there is a problem that the damper wire 12 has an adverse effect by transmitting vibrations.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The vertical scanning of a color picture tube is performed by changing the resonance frequency at which a change in image brightness or color misregistration becomes noticeable when the aperture grill resonates. Determined in relation to the frequency, by setting the resonance frequency of the aperture grill to be shifted from the resonance frequency at which the luminance change and color misregistration become conspicuous, the damper wire used for vibration suppression of the aperture grille strip can be obtained. It is an object of the present invention to provide a color picture tube in which a luminance change and a color shift caused when an external impact is applied during operation or the like are made inconspicuous without being provided.

[0012]

A color picture tube according to the present invention comprises a scanning means for horizontally and vertically scanning an electron beam emitted from an electron gun, and an electron beam scanned by the scanning means for a phosphor screen. An aperture grill that performs color selection so as to irradiate a phosphor of a predetermined color, and a frame that extends and supports the aperture grill, and suppresses vibration of the aperture grill between the aperture grill and the frame. A color picture tube provided with a color selection electrode assembly without a damper wire,
Among the ω values satisfying the equation ω = ωv · n / N where the resonance frequency of the aperture grille is defined by the vertical scanning frequency ωv of the electron beam and arbitrary positive integers n and N, an index representing the contrast of an image The values of ω having a large value of 1 / n · N used as the 、 are successively arranged in two adjacent frequency trains.
It is set in a frequency band divided by two frequencies.

Further, the resonance frequency is distributed from the horizontal center portion to the peripheral portion of the aperture grille, and the distribution of the resonance frequency is set in a frequency band defined by two adjacent frequencies. . Furthermore, the distribution of the resonance frequency of the aperture grill is set in a frequency band defined by two adjacent frequencies in a high frequency region where the amplitude at the time of resonance falls within a predetermined range. . The high frequency region is set to 350 Hz or more, and the width of the resonance frequency distribution is set to 40 Hz.

Furthermore, scanning means for scanning the electron beam emitted from the electron gun horizontally and vertically, and a number of slit-shaped openings and strips formed between the openings are arranged in order and scanned by the scanning means. An aperture grill that performs color selection so that the electron beam irradiates the phosphor of a predetermined color on the phosphor screen, and a frame that extends and supports the aperture grill, and between the aperture grill and the frame. A color picture tube provided with a color selection electrode assembly not provided with a damper wire for suppressing vibration of the aperture grill, wherein a wide portion in which the width of the longitudinal end of the strip is widened toward the opening side is large. And the wide portion is formed only at one end. In addition, the wide part,
It is formed symmetrically with respect to the longitudinal center axis of the strip.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the detailed description, the horizontal and vertical scanning frequencies of a color picture tube will be described. In the present invention, only the vertical scanning frequency is directly related. It should be noted that what the person perceives as the luminance change based on the resonance of the aperture grille 10 is not the vibration of the aperture grille strip 9 itself. That is, the so-called shadow moves on the phosphor screen 3 corresponding to the opening 11 of the aperture grill 10. However, a raster scanning system actually forms a raster at horizontal and vertical scanning frequencies, and when the scanning method is 1: 1 progressive (sequential scanning), one image is formed in one period of vertical scanning. Making Thus, one can say that one is viewing the image with a filter at the frequency of the raster scan. This is the first point of interest of the present invention. A second point of interest is that only the vertical scanning frequency needs to be considered. This is because the horizontal scanning frequency is generally set to, for example, 15 KHz or more, and human eyes do not respond to a change in an image due to such a high frequency and can be ignored in practice.

Embodiment 1 FIG. 1 is an explanatory diagram illustrating the structure of the shadow grill used in the first embodiment and the resonance frequency distribution of the aperture grill. In FIG. 1A, the same parts as those in FIG. Reference numeral 71 denotes a shadow grill. The aperture grill 10 is supported by a frame 8 in an extended state, similarly to the shadow grill 7 shown in FIG. However, the damper wire 12 and the damper spring 13 are not provided. This is the most different point from the conventional example. This is because, as described above, it has been found that the damper wire 12 provided to suppress the vibration of the aperture grille 10 has a bad influence by transmitting the vibration. Although a detailed description will be described later, Embodiment 1
When the aperture grill 10 resonates, a resonance frequency at which a luminance change or a color shift of an image becomes conspicuous is determined in relation to a vertical scanning frequency of the color picture tube, and the resonance frequency of the aperture grill 10 is determined by the luminance change or color. By setting the shift from the resonance frequency at which the shift is conspicuous, deterioration of an image due to an external impact or the like is made less noticeable without providing the damper wire 12.

FIG. 1B is a diagram showing a resonance frequency distribution of the aperture grille used in the first embodiment, in which the aperture grille 10 has a tension distribution from a horizontal center portion to a horizontal peripheral portion. . That is, in the vicinity of the center, the resonance frequency exceeds 370 Hz, which exceeds 350 Hz.
(Ωm1) and 410 Hz (ωm2) in the peripheral portion, and the difference is 40 Hz. In addition, as described later,
ωm1 and ωm2 are set to values deviated from the resonance frequency (resonance frequency at which the luminance change and color shift of the image become conspicuous, that is, high contrast resonance frequency ωc) where the value of C in FIG. 2 is large.

Next, how to set the resonance frequency of the aperture grill 10 will be described. Table 1 is a matrix table showing n / N values for positive integers n and N for n = 1 to 6 and N = 1 to 6.

[0019]

[Table 1]

Further, Table 2 shows that, for n and N in Table 1, ω in the case where the vertical scanning frequency ωv is 60 Hz is expressed by the following equation (1).
(= Ωv · n / N) value. ω = ωv · n / N─ (1)

[0021]

[Table 2]

Next, when the resonance frequency of the aperture grille 10 is equal to the ω value shown in Table 2, how the deterioration of the screen depends on the relationship between the vibration of the aperture grille 10 and the vertical scanning of the screen will be considered. I do. For example, in Table 2, ω = 6
0 Hz has the following meaning. When the aperture grill 10 resonates, the aperture grill 10 provided corresponding to the entire surface of the phosphor screen 3 does not usually have the same resonance frequency on the entire surface, but has the resonance frequency depending on the location. Here, for the sake of simplicity, only resonance in a specific small area is considered. This corresponds to the case where the resonance frequency is 60 Hz. In this case, the fact that the aperture grill 10 swings at a period of 60 Hz means that when the raster is drawn by the vertical scanning of 60 Hz, the swing of the aperture grill 10 is completely synchronized, and thus the aperture grill 10 by the electron beam is used. The shadow appears to be stationary. That is, an image is formed in exactly the same manner as when the aperture grill 10 does not resonate.

In Table 1, n / N = 1/2 and in Table 2, ω = 30H
z, that is, the resonance frequency ω of the aperture grill 10
If m is 30 Hz, two images are formed during one vibration period. If one of these images is an image formed at a regular position, the remaining one image is an image formed at the position of the maximum amplitude when the aperture grill 10 resonates. The fact that the aperture grill 10 resonates means that the position of the opening 11 of the aperture grill 10 shifts with the vibration, so that the electron beam 5 is not a regular phosphor stripe but a phosphor that emits another adjacent color. A phenomenon of irradiating the stripe may occur. Therefore, the image formed as described above has a color shift. Of course, depending on the amount of displacement of the opening 11 at the time of resonance, various cases occur, such as a case where a normal color is not emitted while a normal color is emitted instead of another color. In any case, in most cases, the light is dimmed in this way. In this case, it is sensed as color unevenness.

Next, in Table 1, n / N = 5/6, and in Table 2, ω =
If the frequency is 50 Hz, that is, if the resonance frequency ωm of the aperture grill 10 is 50 Hz, the same phenomenon occurs as described above. But,
In this case, the same phenomenon occurs repeatedly for every six images. In other words, the dimming of each image due to the resonance of the aperture grille 10 is the same in that the image is deteriorated due to the resonance of the aperture grille 10, but the degree thereof is smaller than that in the case of n / N = １ ／. There is a difference in that it is smaller. Therefore, if resonance of the aperture grille 10 cannot be avoided, it can be said that the image deterioration is less likely to be noticeable to a viewer at 50 Hz.

Next, considering the relationship between the vibration energy and the frequency, for example, the force F acting on the mass m in a simple vibration is expressed by the following equation. F = md ² x / dt ² = −mΩ ² x where x: amplitude, T: period = 2π / Ω, f: frequency =
Ω / 2π, Ω: When angular frequency, because the F~Ω ² x~f ² x, F: Given a constant, a f ² x = constant, further constant displacement amount at a particular frequency Given x, 1
/ F ² . Table 3 below summarizes what has been described above.

[0026]

[Table 3]

Here, ωm: resonance frequency, n / N: the same as in Table 1, n · N: an index for easily recognizing a change in screen (contrast), C (= 1 / n · N): screen An index indicating the degree of noticeability (contrast) with respect to the change of the image; k: an index indicating the tendency of fluctuation at each frequency when external vibration energy and amplitude are constant; C · k: general raster scanning Is an index of how easily the screen changes for each frequency when the aperture grill has resonance.

Next, n · N (index for contrast) and C (= 1 / n · N) (index for contrast) will be described. Already, n / N is 1/2 and 5 /
The case of No. 6 was explained, and it was shown that 5/6 is more advantageous in making the resonance less noticeable in the present invention.
Here, the description has been given of the positive integer value n · N which is an index of the advantage. According to this index, as the n · N value is smaller, the contrast of the image is higher, and the resonance is conspicuous. Therefore, C (= 1 / n · N) is effective as one index indicating the contrast. FIG. 2 is a diagram showing the relationship between the resonance frequency ωm and the contrast C. In the graph of FIG. 2, the horizontal axis represents the resonance frequency ωm on a logarithmic scale, and the vertical axis represents the contrast C. FIG.
The graph of 60 shows that the vertical deflection frequency is commonly used 60
In the case of Hz, 10, 12, 15, 20, 30, 4
0,60,90,120,180,240,300,3
It means that it is better that there is no resonance point of the aperture grill system at 60 Hz or the like.

FIG. 3 shows the relationship between the resonance frequency ωm and the index C ·
FIG. 4 is a diagram showing a relationship with k. Here, k shown in Table 3
(Indicator indicating the tendency of fluctuation at each frequency when the external vibration energy and amplitude are constant), Ck (screen at each frequency when resonance occurs in aperture grille in general raster scanning) (A measure of the degree of noticeability of the change). The relationship between the frequency f and the displacement x in the case of constant energy has already been described. According to this, considering the case where the energy applied from the outside is constant, ωm ² · Δ = constant, that is, Δ (displacement) 〜1 / 1 /
Since ωm ² , k = (ωv / ωm) ² is an index of the tendency of fluctuation to occur in general frequency correspondence. Here, when ωv = 60 Hz and ωm = 30, k = 4.

As to the contrast, FIG. 2 shows the specific tendency when resonance occurs. The index C · k shown in FIG.
When it is equal to or less than z, the value becomes 1 or more. Therefore, if there is no peculiar tendency in the natural vibration characteristic in the aperture grill system, when the deflection frequency ωv is 60 Hz, this frequency 60H
It is necessary to reduce the width of the vibration (shake) due to the resonance frequency ωm in the range of z. This is because when the index C · k is 1 or more, the contrast is increased, and the color shift due to resonance is conspicuous. It is also effective to shift the resonance point from resonance at a low frequency such as 20, 15, 12, or 10 Hz.
The horizontal axis in FIG. 3 is a logarithmic scale.

Next, according to FIG. 2 described above, when the vertical deflection frequency ωv is 60 Hz, the resonance frequency ωm is 36
0, 300, 240, 180, 120, 90, 60, 4
If there are resonance points at 0, 30, 20, 15, 12, and 10,
It is disadvantageous because the contrast is increased. Note that these frequencies are referred to as a high contrast resonance frequency ωc. From the above, it can be seen that it is only necessary to bring the resonance point to a frequency shifted from these resonance frequencies.
Therefore, in a frequency band divided by two adjacent frequencies in the frequency train, for example, a frequency band exceeding 300 Hz and 3
If the resonance frequency of the aperture grill 10 is set within a band such as up to 60 Hz or between 240 Hz and 300 Hz, even if the aperture grill 10 resonates,
The deterioration of the screen due to the resonance is not conspicuous. The difference between two adjacent frequencies is 60, 60, 6 respectively.
0, 60, 30, 30, 20, 10, 5, 3, 2 Hz. That is, when the resonance frequency ωm exceeds 60 Hz, the shift amount may be set to 60/2 = ωv / 2.
In actual design, it may not always be possible to determine, so even if Δω ≦ 2 × 60/3, the effect can be deviated from ωc.

By the way, in the aperture grill type shadow grill 7, the tension of the aperture grill strip 9 can be almost freely adjusted so that the phosphor screen can be adjusted.
3 The distribution of tension is intentionally provided over the entire surface. The distribution at this time is, for example, the aperture grill 10
Assuming that 200 Hz is near the center and 320 Hz is near the center, the difference is 120 Hz and the width is large, and there are two high contrast frequencies ωc in this width, so resonance may occur at those two frequencies. Comes out. Therefore, in order to provide a distribution at the resonance points between the center and the periphery (a distribution of the tension of the aperture grille strip 9), the width of the distribution needs to be smaller than the difference between the two adjacent frequencies. In the first embodiment, 40 Hz is used between the center and the periphery.
And the high contrast resonance frequency ωc is not included in this width.

In the first embodiment, the thickness, tension and material of the aperture grille strip are determined so that the resonance frequency of each aperture grille strip 9 is 350 Hz or more. By increasing the resonance frequency in this way, as described above, the amplitude at the time of resonance can be kept within an allowable range with a certain amount of energy. For example, the amount can be determined as 5-10 μm. By doing so, it is possible to make the luminance change and color shift of the screen due to the resonance of the aperture grill 10 less noticeable without providing the damper wire 12 which has been conventionally used.

Next, the shape and arrangement of the strips of the aperture grill used in the first embodiment will be described with reference to FIG. In the first embodiment, the width of every other one of the strips 9 of the aperture grill 10 is changed so that the strip main body is less likely to swing. In FIG. 4, d1 indicates a width wider than the conventional width, and d2 indicates a conventional width. By arranging every other in this way, the deterioration in luminance due to the increase in width and the improvement in the strength of the strip can be matched. In other words, giving priority to strength and widening the width at all ends is advantageous in terms of strength,
It is disadvantageous in terms of brightness. Therefore, every other is used. In addition, in terms of luminance, only the extreme part is present, so that deterioration is not so noticeable. On the other hand, the strength is improved as compared with the prior art.

FIG. 4 shows the shape of the upper end of the aperture grille strip 9. The arrangement pitch P of the openings (slits) 11 is 210 μm and the slit width W is 48 μm. d
1, d2 is the width of the aperture grille strip 9, d2 is the conventional width, and d1 is the wide width measured at the boundary between the straight line portion and the semicircular portion. d1 = 186 μm, d2 = 162
μm. Further, the portion to be widened is such that the length L from the end of the slit 11 is 48 μm and the radius r1 is 12 μm.
It is formed by an arc portion of m and a straight line extending to the end of L following the arc portion. r2 = 24 μm is the radius of the conventional slit end. As described above, the portion where the width of the strip 9 is widened, that is, the wide portion between the dashed lines A and B is a very small portion equal to the width of the slit. Can hardly be perceived by your eyes. FIG. 4 shows only three slits and two strips, and omits the others. However, in the actual aperture grill, a large number of aperture grilles having a width of d1 and those having a width of d2 are alternately arranged. Is what is being done. FIG. 4 shows only the upper end in the vertical direction, but the lower end is also the same. That is, the upper d2 strip is d2, and the upper d1 strip is d1.
It has become.

Next, if the frame 8 resonates, it is transmitted to the aperture grille strip 9 as it is, which is disadvantageous because it promotes the vibration. Therefore, for example, it is better to shift the resonance frequency of the frame 8 and the resonance frequency of the aperture grille strip 9 to obtain better results. Therefore, as an example, in the first embodiment, as shown in FIGS.
The number of points for supporting the frame 8 with respect to the panel 1 is increased from 4 to 6
To the point. Alternatively, a leaf spring 151 as shown in FIG. 6 may be used.

Embodiment 2 FIG. 7 is an explanatory view illustrating Embodiment 2 which is another example of the shape and arrangement of the strips of the aperture grill. In the second embodiment, similarly to the first embodiment, the width of the aperture grille strip 9 is changed every other. The dimensions are also d1 = 186 μm, d2 = 1
62 μm. Also, r1, r2, L, W, and P are the same as in the first embodiment. However, the upper and lower sides of one strip are asymmetric. That is, as shown in FIG. 7, the shape of the upper end is wide d1, and the width of the lower end is d2. FIG. 7 shows one strip 9 and two openings 11, and other parts are not shown. However, the strip 9 next to FIG.
2. The lower end is d1. By doing so, it is possible to provide an aperture grill that balances the deterioration of luminance and the reinforcement of strength, as in the first embodiment. FIG. 7 is drawn in an easy-to-understand manner, and the ratio of the width to the length is large.

Embodiment 3 In the first and second embodiments, the portion where the width of the strip 9 is widened can be variously deformed by changing the shape or the size, but in the third embodiment, the width of the strip 9 is changed. The shape of the piece 9 is symmetrical with respect to the longitudinal axis, that is, the central axis in the Y-axis direction (Q in FIG. 7). By doing so, it is possible to prevent the strip 9 from being twisted when the strip 9 of the aperture grill 10 is extended in the Y-axis direction and in the heat treatment step in the subsequent step.

In the first to third embodiments, the case where the vertical scanning frequency ωv is 60 Hz is described.
Can be implemented in the same way by obtaining each value in Table 3 at that frequency.

[0040]

As described above, the present invention provides a scanning means for horizontally and vertically scanning an electron beam emitted from an electron gun, and an electron beam scanned by the scanning means for emitting a fluorescent light of a predetermined color on a phosphor screen. An aperture grille that performs color selection so as to irradiate the body, and a frame that extends and supports the aperture grille, and a damper wire that suppresses vibration of the aperture grille is provided between the aperture grille and the frame. A color picture tube with a color selection electrode assembly, wherein the resonance frequency of the aperture grille is defined by the equation ω = ωv defined by the electron beam vertical scanning frequency ωv and any positive integers n and N.・
Of the ω values satisfying n / N, the ω values having a large value of 1 / n · N used as an index indicating the contrast of the image are frequency bands partitioned by two adjacent frequencies in a frequency sequence formed in order. Therefore, it is possible to obtain a color picture tube in which a change in brightness and a color shift caused when an external impact is applied during operation or the like are made inconspicuous without providing a damper wire.

Further, scanning means for scanning the electron beam emitted from the electron gun horizontally and vertically, and a number of slit-shaped openings and strips formed between the openings are arranged in order and scanned by the scanning means. An aperture grill that performs color selection so that the electron beam irradiates a phosphor of a predetermined color on the phosphor screen, and a frame that extends and supports the aperture grill, wherein an aperture is provided between the aperture grill and the frame. A color picture tube provided with a color selection electrode assembly not provided with a damper wire for suppressing the vibration of the grill, wherein a wide portion in which the width of the longitudinal end of the strip is widened toward the opening side has a large number. Since it is formed on every other strip, an aperture grill which balances deterioration of luminance and reinforcement of strength can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a structure of a shadow grill used in a first embodiment and a resonance frequency distribution of an aperture grill.

FIG. 2 is a diagram showing a relationship between a resonance frequency ωm and a contrast C.

FIG. 3 is a diagram showing a relationship between a resonance frequency ωm and an index C · k.

FIG. 4 is an explanatory diagram illustrating shapes and arrangements of strips of an aperture grill used in the first embodiment.

FIG. 5 is an explanatory diagram illustrating a method of supporting a shadow grill.

FIG. 6 is a side view showing an example of a leaf spring.

FIG. 7 is an explanatory view illustrating Embodiment 2 which is another example of the shape and arrangement of the strips of the aperture grill.

FIG. 8 is a plan view showing a cross section of a part of a conventional color picture tube.

FIG. 9 is a perspective view showing the structure of a conventional shadow grill.

[Explanation of symbols]

7, 71 color selection electrode assembly (shadow grill), 8
Frame, 9 aperture grille strip, 10 aperture grille, 11 opening (slit), 15 leaf spring, ω
c High contrast resonance frequency.

Claims (7)

[Claims] 1. Scanning means for horizontally and vertically scanning an electron beam emitted from an electron gun, and color selection so that the electron beam scanned by the scanning means irradiates a phosphor of a predetermined color on a phosphor screen. And a frame for extending and supporting the aperture grill, wherein a color selection electrode assembly is not provided between the aperture grill and the frame, wherein a damper wire for suppressing vibration of the aperture grill is not provided. Wherein the resonance frequency of the aperture grill is defined by the equation ω = ωv · n / N defined by the vertical scanning frequency ωv of the electron beam and arbitrary positive integers n and N. Of the ω values to be satisfied, 1 / n used as an index indicating the contrast of the image
A color picture tube characterized in that ω values having a large value of N are set in a frequency band defined by two adjacent frequencies in a frequency train formed in order. 2. The method according to claim 1, wherein a resonance frequency is distributed from a central portion to a peripheral portion in the horizontal direction of the aperture grille, and the distribution of the resonance frequency is set in a frequency band defined by two adjacent frequencies. The color picture tube according to claim 1, wherein 3. The distribution of the resonance frequency of the aperture grille is set in a frequency band defined by two adjacent frequencies in a high frequency region where the amplitude at the time of resonance falls within a predetermined range. 3. The color picture tube according to claim 2, wherein: 4. The high frequency region is above 350 Hz,
4. The color picture tube according to claim 3, wherein the width of the resonance frequency distribution is set to 40 Hz. 5. A scanning means for horizontally and vertically scanning an electron beam emitted from an electron gun, and a large number of slit-shaped openings and strips formed between these openings are arranged in order, and are scanned by said scanning means. An aperture grille that performs color selection so that the electron beam irradiates the phosphor of a predetermined color on the phosphor screen, and a frame that extends and supports the aperture grille, between the aperture grille and the frame. A color picture tube provided with a color selection electrode assembly that is not provided with a damper wire that suppresses vibration of the aperture grille, wherein a wide portion in which the width of the longitudinal end of the strip is widened toward the opening side is provided. A color picture tube formed every other one of a number of strips. 6. The color picture tube according to claim 5, wherein the wide portion is formed only at one end. 7. The color picture tube according to claim 5, wherein the wide portion is formed symmetrically with respect to a longitudinal center axis of the strip.