JP2000011913A - Color picture tube and stretching method of its shadow grill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce luminescence variations, even if a shadow grill resonates when an impact is impressed. SOLUTION: Each pair of pins 21a, 21b and 23a, 23b are installed side by side on each side inside a glass panel 1 corresponding to the respective upper and lower edges of a rectangular phosphor screen by separating them from each other by a predetermined distance generally at its central position, in order to suspend and support a shadow mask 7 embedded in the glass panel 1 used in a color picture tube. The shadow mask 7 is fixed firmly in the panel 1 and can thereby shift its resonant frequency to the higher side with respect to the vibrations transmitted from the outside.

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 for forming a color image on a phosphor surface of three colors by scanning while deflecting an electron beam in horizontal and vertical directions, and a shadow grill extending method thereof. More particularly, the present invention relates to a shadow mask as a color selection mechanism with improved vibration resistance.

[0002]

2. Description of the Related Art Some color picture tubes for television reception or computer terminals have a shadow grill extended as a color selection mechanism.

FIG. 12 is a top view showing a partial cross section of an example of a conventional color picture tube. In the drawing, reference numeral 1 denotes a glass 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 fluorescent light of each color of red, blue and green on the inner surface of the panel. A fluorescent screen in which the bodies are arranged in a band-like order,
The electron gun 5 has a (trajectory) of an electron beam emitted from the electron gun 4, and a deflection yoke 6 electromagnetically deflects the electron beam 5.

[0004] Reference numeral 7 denotes an expansion-type shadow grill that is expanded on the fluorescent screen 3. This shadow grill 7
Is an aperture grill type having a plurality of slit-shaped openings in the vertical direction with respect to the fluorescent screen 3.
The frame 8 of the grill is fixed by fitting a pin 9 formed on the inner surface of the panel 1 with a hole of a leaf spring 10 provided on the frame 8. And is supported in a state of being extended at a predetermined position inside. Reference numeral 11 denotes a mounting ear piece provided on the panel 1 for fixing the color picture tube to a cabinet or the like.

The shadow grill 7 of such a color picture tube functions as a color selection electrode like a so-called round hole or slot type shadow mask type. Below,
Those having the functions of these various color selection electrodes are called shadow masks. However, when the color picture tube is specifically described as a slit hole type, it is particularly called a shadow grill.

FIG. 13 (A) is a perspective view showing the structure of a conventionally used stretch type shadow grill, and FIG. 13 (B).
FIG. 2 is a perspective view showing a frame of a shadow grill including a pair of horizontal members and a vertical member holding the horizontal members.

The frame 8 includes two horizontal members 8a serving as horizontal members and two V members 8b serving as vertical members. These members are made of a lightweight steel material such as SUS. The members 8a of the frame 8
0. A large number of tape-shaped strips made of rimmed steel having a thickness of 1 mm are welded in a stretched state, and slit-shaped openings 12 are formed by these tape-shaped strips.

The aperture grill 7 is provided with two damper wires 13 made of a tungsten wire having a diameter of 25 μm so as to come into contact with the tape-shaped strip in a direction perpendicular to the longitudinal direction thereof. . These damper wires 13 are for suppressing the swinging of the aperture grille 7 when the color picture tube vibrates and falls, and is formed by a spring action of a damper spring 14 welded to the V member 8b of the frame 8. Each strip is held down.

Next, the operation of the color picture tube will be described.

The inside of an envelope constituted by the panel 1 and the funnel 2 is kept in a high vacuum, and the electron beam 5 emitted from the electron gun 4 is formed on the inner surface of the panel 1 and a high voltage is applied. And hits the fluorescent screen 3. At this time, a horizontal and vertical deflection magnetic field having, for example, a horizontal cycle and a vertical cycle of 30 KHz and 60 Hz, respectively, is applied to the electron beam 5 from the deflection yoke 6, and the electron beam 5 is simultaneously deflected in the horizontal direction and the vertical direction. To form an image display area referred to as the image display area. In the image display area of the fluorescent screen 3, the red, blue and green phosphors emit light in accordance with the amount of impact of the electron beam 5, and the distribution of their emission intensities is observed from the outer surface of the panel 1. It can be recognized as an image of a picture tube.

A large number of slit-shaped openings 12 are arranged in the shadow grill 7 in order, and when the electron beam 5 passes through the openings 12, the red, blue and green phosphors are geometrically arranged. The light strikes a predetermined position on the fluorescent screen 3 on which the stripe is formed, and color selection is performed accurately. In a shadow grill type color picture tube, since such color selection 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. . On the other hand, color picture tubes
When assembling the panel 1, the electron gun 4, and the shadow grill 7, there is a design margin in order to absorb variations in the dimensions of each part. In addition, since the shadow grill 7 is configured such that the tape-like strip is extended by the frame 8, the positional accuracy is unstable, and the shadow grill 7 is particularly susceptible to vibration and impact. As one of the measures, the two damper wires 13 are provided.

[0012]

As described above, the color selection electrode of the shadow grill type is designed such that each strip is firmly fixed to the frame 8 and each of them is in an extended state. There is no particular problem if is in a static state. However, since the shadow grill 7 is formed of an elongated tape-shaped strip in the vertical direction from one side to one side of the rectangular screen structure, the position of the opening 12 is not stable. In particular, when mechanical vibration or impact is applied from the outside, the problem that the shadow grill 7 shakes occurs.

Such a fluctuation is not a problem as long as it can be absorbed by the above margin, but if the fluctuation exceeds a certain limit, it becomes a problem not only for the shadow grill type but also for the shadow mask in general. In addition, there is a problem that when the light emission luminance of each color of the fluorescent screen 3 changes to a considerable extent and the degree of fluctuation is severe, a color shift of an image occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a color picture tube capable of reducing a change in luminance even when a shadow grill resonates when an impact is applied, and a shadow tube thereof. The purpose is to provide a method for extending the grill.

[0015]

According to a first aspect of the present invention, there is provided a color picture tube for forming a color image on a phosphor surface of three colors by scanning by deflecting an electron beam in horizontal and vertical directions. The picture tube includes a shadow mask forming a color selection electrode with respect to the phosphor surface, and a scanning frequency ωv for vertically scanning the electron beam, and 1 ≦
ω = ωv · n / N (1) The resonance frequency ωm of the shadow mask is predetermined for an ω value satisfying the expression (1) defined by arbitrary integers n and N satisfying n and N ≦ 6. Are shifted by the value Δω.

In the color picture tube according to a second aspect of the present invention, when the ω value satisfying the expression (1) is a frequency of 400 Hz or less, the resonance frequency ωm of the shadow mask is changed to the expression (2) 0 <Δω .Ltoreq.2.omega.v / 3 (2) It is shifted within a range of a value .DELTA..omega.

In the color picture tube according to a third aspect of the present invention, the resonance frequency .omega.m of the shadow mask shifted within the range of the value .DELTA..omega. Satisfying the above expressions (1) and (2) is set to a value not exceeding the scanning frequency .omega.v. It is what you are doing.

In a color picture tube according to a fourth aspect of the present invention, the shadow masks corresponding to the center position and the peripheral position of the phosphor surface have different resonance frequencies ωm from each other.
1, constituted by a shadow grill having ωm2,
The difference Δωm between the resonance frequencies ωm1 and ωm2 is set to a value smaller than the scanning frequency ωv.

A color picture tube according to a fifth aspect of the present invention is a color picture tube which forms a color image on a phosphor surface of three colors by scanning by deflecting an electron beam in horizontal and vertical directions. And a pair of horizontal members to which the shadow grill is fixed, and a vertical member holding the horizontal members, and each of the vertical members has at least two suspension elastic members. The frame includes a frame to which the members are fixed, and a glass panel having pins for holding the frame by a suspension elastic member, and the horizontal and vertical members of the frame are made of different materials.

A color picture tube according to a sixth aspect of the present invention is a color picture tube which forms a color image on a phosphor surface of three colors by scanning by deflecting an electron beam in horizontal and vertical directions. A shadow grill that forms a color selection electrode, a pair of horizontal members to which the shadow grill is fixed, and a vertical member that holds these horizontal members. Each of the vertical members and the horizontal members has a suspension elasticity. The frame includes a frame to which members are fixed, and a glass panel having pins for holding the frame by a suspension elastic member, and the glass panel is provided with six or more pins.

In a color picture tube according to a seventh aspect of the present invention, at least two kinds of different materials or different shapes are used for the suspension elastic member fixed to the frame.

In a color picture tube according to an eighth aspect of the present invention, a pin is provided on each long side of the glass panel near the corner of the phosphor surface.

In the color picture tube according to the ninth aspect of the present invention, the scanning frequency ωv is 50 Hz or more.

According to a tenth aspect of the present invention, there is provided a shadow grill extending method for a color picture tube according to any one of the fifth to eighth aspects, wherein a scanning frequency ωv for vertically scanning an electron beam and a scanning frequency ωv are provided. , 1 ≦ n, N
The shadow grill is extended so that the resonance frequency ωm of the shadow grill is shifted by a predetermined value Δω with respect to the ω value satisfying the expression (1) defined by arbitrary integers n and N satisfying ≦ 6. is there.

According to the eleventh aspect of the present invention, when the ω value satisfying the expression (1) is a frequency of 400 Hz or less, the resonance frequency ωm of the shadow grill satisfies the expression (2). Is shifted within the range of the value Δω.

In a shadow grill extending method according to a twelfth aspect of the present invention, the resonance frequency ωm of the shadow grill is set to a value not exceeding the scanning frequency ωv.

In the shadow grill extending method according to a thirteenth aspect of the present invention, the difference Δωm between the resonance frequencies of the shadow grill corresponding to the center position and the peripheral position of the phosphor surface is set to a value smaller than the scanning frequency ωv. Things.

[0028]

First, a vibration test of a shadow mask in a shadow mask system will be described.

A color picture tube is constructed using various parts. The glass bulb as an envelope is provided not only with a shadow mask, but also with an electron gun and a deflection yoke. When vibration energy is applied to these components from outside the color picture tube, each of them causes resonance, which is unsatisfactory. Image and reliability issues arise. The deflection yoke 6, which is an external component, is excluded here because it is relatively easy to take measures against vibration. In addition, a special case of the electron gun is also a problem, and is excluded here.

In general, a cathode ray tube type color picture receiver is used in a stationary state, and a color picture tube for an aircraft or a vehicle used under vibration is special. Therefore, conventionally, measures against vibrations have been limited to problems that occur with the transportation of products. However, recently, as TV receivers have become larger, many monitors have built-in speakers. In addition, it is inevitable for multimedia to have a built-in speaker.

Therefore, at present, it is built in the receiver,
Alternatively, vibration transmitted from a speaker provided in close proximity is also a problem. For this speaker vibration, a sweep test from an extremely low tone to about 20 KHz is generally performed. In the vibration test of the shadow mask, the conventional vibration conditions at the time of transportation, for example, 1000 rpm, amplitude 2
It is also necessary to consider test conditions such as mm and 30 minutes. In the impact test during transportation, for example, an impact resistance of 25 G is required. Furthermore, the hammer test, in which the panel is hit from the outside during the operation of the picture tube and the vibration generated at that time is tested, is performed under severe vibration conditions when the usage of an aircraft monitor is considered. You. In such a hammer test, the frequency component of the vibration is usually 400
Hz or less.

As described above, in the vibration test of the shadow mask of the color picture tube, not only the vibration and shock during transportation but also the fact that a shock is applied from the outside as vibration energy during operation is considered. The energy supplied from the outside is transmitted to the grill piece through the following route.

Vibration source → cabinet → picture tube mounting ear → panel → pin → mask suspension spring → frame → grill piece When vibration is transmitted to the grill piece on this route, the brightness and chromaticity of the three primary colors of the image will be It changes and is perceived by the human eyes as shaking of the image. That is, a human eye perceives the image as a defect according to the vibration characteristics of the shadow mask.

Here, it is not always necessary to eliminate the vibration itself, taking into account that it is not the vibration of the grille itself that is sensed by the person as the luminance change. That is, since the image is formed by the electron beam passing through the aperture of the aperture grille, the shaking of the image moves as a shadow of the aperture projected on the phosphor screen. In addition, in an image receiving system by raster scanning, a raster is constituted by horizontal and vertical scanning frequencies, and the image scanning method is as follows:
In the case of 1 progressive (non-interlaced system), one image is created in one cycle of vertical scanning, or in the case of 1: 2 interlaced system, half of each image is created in one cycle of vertical scanning. Thus, they are synthesized in two vertical scanning periods.

Therefore, the image perceived by the human eye is
This is equivalent to a filtered image proportional to the frequency of raster scanning. This point is a first point of interest in the color picture tube of the present invention described below.

The second point of interest is that, of the scanning conditions of the horizontal and vertical scanning frequencies, only the vertical scanning frequency is directly related to the color picture tube of the present invention. This is because the horizontal scanning frequency is generally set to, for example, 15 KHz or more, and human eyes do not respond to such a change in the image that changes at such a high frequency, and can be ignored in practice. Therefore, in the following description, only the vertical scanning frequency ωv (for example, 60 Hz) is assumed.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a diagram illustrating a pin arrangement of a glass panel used in the first embodiment.
The external configuration of the color picture tube is the same as that of the conventional example (FIG. 12), and a description thereof will be omitted.

In the first embodiment, the arrangement of pins for suspending and supporting a shadow mask 7 embedded in a glass panel 1 used in a color picture tube is different from the conventional arrangement. That is, each of the two sides of the inner side of the panel 1 corresponding to the upper and lower edges of the rectangular fluorescent screen is spaced apart from each other by a predetermined distance at a substantially central position thereof.
a, 21b, 23a and 23b are provided side by side.
The pins 22 and 24 of the panel 1 corresponding to the left and right edges of the fluorescent screen are provided one by one as in the conventional case.

Corresponding to the pin arrangement of the panel 1, the same number of leaf springs 10 for holding the mask are welded to the frame 8 of the shadow mask 7. Pins 21a, 21b, 22, 23a, 23b, 2
A hole of a corresponding size is formed at a position corresponding to 4,
They fit together to hold the frame 8.

FIG. 2 is a diagram illustrating the pin arrangement of a conventional glass panel. In the conventional pin arrangement, the panel 1 is provided with only four pins 9 in a plane parallel to the shadow mask 7.

On the other hand, in the case of Embodiment 1,
Since six pins are arranged in a plane parallel to the mask surface of the shadow mask 7, the shadow mask 7
In this case, the resonance frequency is more firmly fixed than the conventional one, so that the resonance frequency of the vibration transmitted from the outside can be shifted higher.

FIG. 3 is a diagram showing a distribution state of the resonance frequency of the shadow grill. The shadow mask 7 used here is assumed to be a shadow grill type shown in FIG. As shown in FIG. 3, the vibration characteristics of the tape-shaped strip of the shadow grill 7 corresponding to the center (center position) in the left-right direction of the fluorescent screen have a resonance point ωm1 of 300 Hz, for example, and The vibration characteristic of the corresponding strip is, for example, the resonance point ωm of 350 ° z.
2 That is, the tension of the tape-shaped strip is set such that the resonance frequency difference Δωm becomes 50 Hz at the maximum according to the position of the shadow grill.

FIG. 4 is a diagram showing a distribution state of a resonance frequency of a conventional shadow grill. The vibration characteristic is, for example, 20
It is distributed as 0 Hz-320Ηz, and the resonance frequency difference is 120 Hz.

Comparing the distribution states shown in FIGS.
The vibration characteristics of the shadow grill of the first embodiment shown in FIG. 3 can increase the resonance frequency in all distributions as compared with the conventional one shown in FIG. Moreover, in the first embodiment, the resonance frequency corresponding to the peripheral portion is set to 30H from the central portion.
By increasing the resonance frequency difference Δω by about z
The distribution of the resonance frequency ωm is set such that m is equal to or lower than the scanning frequency ωv (= 60 Hz). It is known that the tension of the tape-shaped strip has a distribution (JP-A-62-253031, JP-A-61-24).
0531).

Next, the resonance frequency ωm of the shadow mask
Will be described with respect to the scanning frequency ωv.

Table 1 shown below is a matrix table showing n / N values for arbitrary integers n and N satisfying 1 ≦ n and N ≦ 6.

[0048]

[Table 1] Table 2 shows a part of the ω (= ωv · n / N) value corresponding to the case where the vertical scanning frequency ωv is 60 Hz in the following equation (1) for N = 1 to 4 in Table 1. I have.

Ω = ωv · n / N (1) The ω value in the equation (1) finally corresponds to the resonance frequency ωm of the shadow mask.

[0050]

[Table 2] For example, in Table 2, ω = 60 Hz has the following meaning.

In general, when the shadow mask resonates,
The shadow mask provided on the entire surface of the fluorescent screen 3 has a different resonance frequency depending on the location. Here, for the sake of simplicity, only the resonance of the shadow mask in a specific small area is considered. The resonance frequency here is 60Hz
Corresponds to the case of

The fact that the shadow mask oscillates at a cycle of 60 ° z means that when an image is drawn on a 60 Hz vertical scanning raster, the shadow mask shakes in synchronization, so that the shadow of the shadow mask does not move. Looks like. Therefore, an image is formed exactly as in the case where the shadow mask is not vibrating.

When n / N = 1/2 in Table 1, that is, when the resonance frequency ωm (= ωv · n / N) in Table 2 is 30 Hz, two images are formed during one vibration period. . If one of the images is an image formed at a regular position, the other image is an image formed at the position of the maximum amplitude when the shadow mask resonates. Therefore, in a color image that is color-selected by the vibrating shadow mask, the electron beam 5 is generated from the phosphor that physically forms the shadow mask and the fluorescent screen 3.
For example, in order to land at a position shifted from the regular stripe, the shadow mask in such a state causes the phosphor stripe that emits another color instead of the regular phosphor stripe to emit light instead of the regular phosphor stripe. Become. Of course, depending on the amount of displacement of the shadow mask at the time of resonance, a case may be considered in which a regular color is emitted instead of another color and the regular emission amount is not reached. In any case, the formed color image is dimmed, and it is inevitable that the luminance is reduced.

In Table 1, when n / N = 5/6, that is, when the resonance frequency ωm (= ωv · n / N) is 50 Hz, the same phenomenon occurs based on the same principle as described above. However, in this case, the same phenomenon repeatedly occurs for every six images. That is, the dimming of each image due to the resonance of the shadow mask is the same in that the image is deteriorated (contrast is reduced) due to the resonance of the shadow mask, but is compared with the case where n / N =＝. There is a difference in that it becomes smaller. Therefore, if the resonance of the shadow mask cannot be avoided, the deterioration of the image is less noticeable to a viewer at 50 Hz.

Next, the relationship between the vibration energy supplied to the shadow mask and the frequency of the vibration will be described.

Generally, the force F acting on the mass m during a simple vibration
Is represented by the following equation (3).

F = md ² x / dt ² = −mΩ ² x (3) where x: amplitude, T: period = 2π / Ω, f: frequency =
Ω / 2π, Ω: angular frequency. Since the above equation (3) is expressed as FΩΩ ² x〜f ² x (4), if F is constant, f ² x = constant, and the displacement x at a specific frequency is 1 / proportional to f ^2.

Next, a landing error caused by a resonating shadow mask will be described.

FIG. 5 is a schematic diagram for explaining the deflection of an electron beam in a color picture tube. In the figure, assuming that the electron beam is deflected from the deflection center P of the deflection yoke 6 at a deflection angle α, the distance from the fluorescent screen 3 is l, the distance from the shadow mask to the inner surface of the panel 1 is q, the shadow due to resonance. The displacement of the mask in the direction of the tube axis (Z axis) is defined as Δ. Then, a landing error (displacement) d on the fluorescent screen 3 is expressed by the following equation (5).

D = Δtanα · l / (1−q) (5) Here, the direction of shaking of the shadow mask at the time of resonance is only the Z-axis direction, but actually, the axial direction orthogonal to the Z-axis is Shaking also occurs. However, especially in the shadow grill type shadow mask, since the masks are formed of independent tape-shaped strips, the other axial directions can be ignored compared to the Z-axis directions. .

Now, let us consider only a certain displacement d. The displacement Δ of the shadow mask in the tube axis (Z-axis) direction due to resonance is as follows: Δ〜1 / tanα (6).

FIG. 6 is a diagram showing the deflection angle of the color picture tube and the allowable displacement of the mask. In the figure, the vertical axis represents the swing amplitude Δ (mm), and the horizontal axis represents the deflection angle α (degree). FIG. 6 shows that the margin for the vibration near the center (α = 0) of the fluorescent screen is larger than the margin.

Table 3 below summarizes what has been described above.

[0064]

[Table 3] Here, ωm: resonance frequency, n / N: same as in Table 1, n · N: index for screen visibility (contrast), C (= 1 / n · N): screen visibility ( An index indicating contrast), k: an index indicating the likelihood of occurrence of fluctuation at each frequency when external vibration energy and amplitude are constant, and C · k: when a grill has resonance in a general raster scan. Of the screen for each frequency.

Next, n · N (index for contrast) and C (= 1 / n · N: index for contrast) in Table 3 will be described.

The case where n / N is 1/2 and 5/6 has already been described, and it has been shown in the present invention that 5/6 is more advantageous for making resonance less noticeable. here,
The positive integer value n · N serving as an index of the advantage has been described. According to this index, as the n · N value is smaller, the contrast of the image is higher, and the resonance is conspicuous.
Therefore, in the following description, C (= 1 / n · N) is used as an index indicating the contrast.

FIG. 7 is a diagram showing the relationship between the resonance frequency and the contrast. The graph of FIG. 7 shows the frequency ω on the logarithmic axis of the horizontal axis, and illustrates the relationship between this frequency ω and the index C (= 1 / n · N) on the vertical axis.
According to this graph, when the vertical deflection frequency ωv is 60 Hz, 10, 12, 15, 20, 30, 40, 6
0, 90, 120, 180, 240, 300, 360H
There is a peak value of the index C in z or the like, and it is understood that the shadow mask system should be configured so that the resonance frequency ωm is not selected for those values. That is, according to FIG. 7, the resonance frequencies are 360, 300, 240, 180, 120, 90,
60,40,30,20.15.12,10,
It is disadvantageous because the contrast is increased.

The frequency difference between adjacent peak values is 60, 60, 60, 60, 30, 30, 20, 1
0, 5, 3, 2 Hz. Therefore, in the shadow mask of the shadow grill type, by freely adjusting the tension of the tape-shaped strip, a distribution is designed to be provided over the entire surface of the fluorescent screen. The distribution at this time is, for example, 200 ° near the center of the shadow mask.
z, the difference is 120Hz, such as 320Hz around
It is wide like. However, resonance of one shadow grill is likely to occur for two types of vibration,
Make the measures difficult. Therefore, even when a difference is made in the resonance point (the difference in the tension of the tape-shaped strip) between the center and the periphery, it is necessary to make the resonance frequency difference Δω smaller than ωv.

Therefore, the resonance frequency ωm of the shadow mask is defined by the above equation (1) defined by the vertical deflection frequency ωv and arbitrary integers n and N satisfying 1 ≦ n and N ≦ 6.
Is set to be shifted by a predetermined value Δω from the ω value that satisfies In this case, the amount Δ that shifts the resonance frequency ωm
ω may be set to 60/2 = ωv / 2. The amount of shift Δω in actual design is not always easily determined. Therefore, there is a certain effect by shifting in the range of Δω ≦ 2ωv / 3.

As described above, in the first embodiment, the frequency of the resonance point of the shadow mask system is increased by changing the number of pins for suspending and holding the shadow mask from four to six. It becomes possible.

Further, by setting the resonance frequency ωm of the shadow mask so as to be shifted from the specific ω value as described above by a predetermined value Δω, the brightness change can be reduced even when the shadow grill resonates when an impact is applied. .

Any number of pins may be used as long as the number of pins is 6 or more.
For example, in the case of holding with seven pins, although the form of supporting the frame is different from that of the first embodiment, for example, the peak frequency can be moved from 190 Hz to 330 ° z.

Embodiment 2 FIG. 8 is a diagram illustrating a relationship between the resonance frequency ωm and the index C · k.

Here, k (indicator of frequency when vibration energy and amplitude are constant) shown in Table 3 and C · k (frequency when resonance occurs during general raster scanning and screen visibility) ) Will be described.

The relationship between the frequency f and the displacement x in the case of constant energy has already been described in equation (4). According to this, considering the case where the energy applied from the outside is constant, ωm ² · Δ = constant, that is, Δ〜1 / ωm ² , so that k = (ωv / ωm) ² corresponds to a general frequency. It is an index of the tendency of the fluctuation to occur. Here, for example, when ωv = 60 Hz and ωm = 30 Hz, k = 4.

Regarding the contrast, the first embodiment is directed to the specific tendency when resonance occurs.
(FIG. 7). The index C · k shown in FIG. 8 has a value of 1 or more when the resonance frequency ωm shifted within the range of the value Δω that satisfies the expressions (1) and (2) is 60 Hz or less. Therefore, if there is no peculiar tendency in the natural vibration characteristics in the shadow mask system, when the deflection frequency ωv is 60 Hz, it is necessary to reduce the width of the vibration (fluctuation) at the resonance frequency ωm in the range of 60 Hz. . Index C · k
Is greater than 1, the contrast is increased, and color shift due to resonance is conspicuous.

At low frequencies such as 20, 15, 12, 10 ° z, it is also effective to shift the resonance point therefrom.

FIG. 9 is a diagram illustrating the pin arrangement used in the second embodiment of the present invention. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In the description of the first embodiment, the resonance frequency ωm is shifted in the direction of increasing the resonance frequency ωm as shown in FIG. However, as can be understood from FIG. 8 described above, the same effect can be obtained even at a resonance frequency ωm equal to or lower than ωv by reducing the amplitude.

In the second embodiment, as shown in FIG. 9B, pins 21a, 21a
9b are arranged side by side in the tube axis direction of the panel 1 and a leaf spring 10 'suspending the shadow mask 7 is provided with the structure shown in FIG.
As shown in FIG. 3 (C), 2 corresponding to the pins 21a and 21b
Two holes 10a and 10b are formed. 10c is a cut separating the leaf spring 10 ', and 10d is a bent portion.

In the color receiver according to the second embodiment, similarly to the first embodiment, the panel 1 is provided with six pins, and has different natural resonance characteristics from each other like the leaf springs 10 and 10 ′. The shadow mask is supported by the held spring, and the magnitude of the fluctuation at the resonance frequency can be reduced.

The resonance distribution of the shadow grill 7 according to the second embodiment is as shown in FIG. 3, as in the case of the first embodiment. Thereby, the resonance point can be shifted from the frequency defined by the above equation (1), and defects such as color shift of an image can be reduced.

As described above, in the second embodiment, when external vibrations are transmitted via the springs, the fluctuation of the absolute value can be reduced by shifting the resonance frequencies of the plurality of springs.

Embodiment 3 FIG. 10 is a diagram showing an arrangement of pins used in the third embodiment.

On each long side of the panel 1, two pins 21a, 21b and 23a, 23b are provided, and on the short side of the panel 1, pins 22 and 24 are provided at the same position as the conventional one. . Here, the long-side pins 21 and 23 are embedded as close to the corners of the panel 1 as possible.

By doing so, the leaf spring 10 of the shadow grill 7 bends on the plane formed by the pins 21 to 24 or on a plane parallel thereto, and the design of the spring system and the attachment and detachment of the spring Conventional devices can be used for the device.

As the weight of the shadow mask system is reduced, a phenomenon in which the frame 8 itself bends due to the vibration of the shadow mask appears. In this case, when the rectangular panel 1 is used, a pin located at or near the corner of the panel 1 rather than a so-called "on-axis" pin disposed substantially at the center of the frame, By holding the mask, it is possible to increase the resonance frequency as in the first embodiment.

Note that the spring may be provided on the diagonal of the panel like a normal corner pin. However, in this case, the spring system for holding the shadow grill is different from the spring having the conventional structure. It is located near the corner.

FIG. 11 is a perspective view showing a shadow grill 7 used in the third embodiment. In the frame 8 of the shadow grill 7, three leaf springs 10 are arranged on the V member 8b, respectively, and are not provided on the H member 8a.

If the panel 1 has such a pin arrangement,
All the springs arranged on the shadow grill 1 are V members 8
b. In the shadow mask of the conventional configuration shown in FIG. 12, the spring 10 is welded to both the H member 8a and the V member 8b. On the contrary,
In the color picture tube according to the third embodiment, the vibration energy transmitted from the outside to the shadow grill 1 through the pins 9 of the panel 1 is transmitted to the V member 8b → H member 8a → tape strip and series.

Therefore, the material of the frame 8 can be selected as an adjusting means for shifting the resonance frequency ωm. For example, @member 8a has SUS410S, V member 8
b may be a chromium molybdenum steel SCM445 material. Also in the third embodiment, the resonance distribution of the shadow grill 7 can be set as shown in FIG.

As described above, in the shadow mask of the shadow grill type, since the frame 8 is constituted by the H member 8a and the V member 8b, the design for shifting the resonance frequency can be performed relatively easily. In this case, frame 8
It is preferable that the material and shape of the H member be different between the H member and the V member.

In the color picture tube of the third embodiment configured as described above, the resonance point of the shadow mask can be shifted and set in the same manner as described in the first embodiment. Can be reduced.

In the above-described embodiment, the vibration resistance characteristics of the shadow grill 7 having the slit type hole are described. However, there is no distinction in the vibration phenomenon of the shadow mask. The present invention can be applied to a shadow mask. Further, it is said that the vertical scanning frequency ωv of the color picture tube is preferably used at 50 Hz or more. This is because, when an image is formed at a frequency lower than this, an afterimage remains in the eyes and becomes unsuitable as a display device.

[0095]

Since the present invention is constructed as described above, it is possible to reduce the luminance change and color shift caused by the fluctuation in the resonance frequency with respect to the vertical deflection scanning frequency when using a color picture tube. By shifting to a frequency that is difficult to see, the deterioration of the image can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a pin arrangement used in a first embodiment of the present invention.

FIG. 2 is a diagram showing a conventional pin arrangement.

FIG. 3 is a diagram showing a distribution state of a resonance frequency of a shadow grill used in the present invention.

FIG. 4 is a diagram showing a distribution state of a resonance frequency of a conventional shadow grill.

FIG. 5 is a schematic diagram for explaining deflection of a color picture tube.

FIG. 6 is a diagram showing a relationship between a deflection angle of a color picture tube and an allowable displacement of a mask.

FIG. 7 is a diagram illustrating a relationship between a resonance frequency and contrast.

FIG. 8 is a diagram showing a relationship between a resonance frequency and an index C · k.

FIG. 9 is a diagram illustrating a pin arrangement used in the second embodiment of the present invention.

FIG. 10 is a layout diagram of pins used in a third embodiment of the present invention.

FIG. 11 is a perspective view showing a shadow grill used in Embodiment 3 of the present invention.

FIG. 12 is a top view including a partly broken section showing a structure of a conventional color picture tube.

FIG. 13 is a perspective view schematically showing a structure of a shadow grill used in a conventional color picture tube.

[Explanation of symbols]

1 panel, 2 funnel, 3 phosphor screen, 4
Electron gun, 5 electron beam, 6 deflection yoke, 7
Expandable shadow grill, 8 frames, 9 pins,
10 leaf spring, 11 ear piece for attachment, 12
Damper wire, 13 Damper spring, 21
~ 24 pins.

Claims (13)

[Claims] 1. A color picture tube which forms a color image on a phosphor surface of three colors by scanning while deflecting an electron beam in horizontal and vertical directions, wherein a shadow constituting a color selection electrode with respect to the phosphor surface. A scanning frequency ωv for vertically scanning the electron beam.
The resonance frequency ωm of the shadow mask is shifted by a predetermined value Δω with respect to an ω value satisfying the expression (1) defined by an arbitrary integer n and N satisfying 1 ≦ n and N ≦ 6. A color picture tube. ω = ωv · n / N (1) 2. An ω value satisfying the above equation (1) is 400H.
The color picture tube according to claim 1, wherein when the frequency is equal to or lower than z, the resonance frequency ωm of the shadow mask is shifted within a range of a value Δω that satisfies Expression (2). 0 <Δω ≦ 2ωv / 3 (2) 3. The resonance frequency ωm of the shadow mask
The color picture tube according to claim 1 or 2, wherein the value of the color picture tube does not exceed the scanning frequency ωv. 4. A shadow mask corresponding to a center position and a peripheral position of the phosphor surface is constituted by a shadow grill having resonance frequencies ωm1 and ωm2 different from each other, and a difference Δωm between the resonance frequencies ωm1 and ωm2 is: 4. The color picture tube according to claim 1, wherein the color picture tube is set to a value smaller than the scanning frequency ωv. 5. A color picture tube for forming a color image on a phosphor surface of three colors by scanning by deflecting an electron beam in horizontal and vertical directions, wherein a shadow constituting a color selection electrode with respect to the phosphor surface. A grill, and a pair of horizontal members to which the shadow grill is fixed,
And a vertical member holding these horizontal members,
A frame in which at least two suspension elastic members are fixed to each of the vertical members; and a glass panel having pins for holding the frame by the suspension elastic members. A color picture tube comprising a material different from a member. 6. A color picture tube for forming a color image on a phosphor surface of three colors by deflecting and scanning an electron beam in horizontal and vertical directions, wherein a shadow constituting a color selection electrode with respect to the phosphor surface is provided. A grill, and a pair of horizontal members to which the shadow grill is fixed,
And a vertical member holding these horizontal members,
A frame in which a suspension elastic member is fixed to each of the vertical member and the horizontal member; and a glass panel having a pin for holding the frame by the suspension elastic member, wherein the glass panel has a pin. A color picture tube comprising six or more color picture tubes. 7. The suspension elastic member fixed to the frame, wherein at least two kinds of different materials or different shapes are used. Color picture tube. 8. The color picture tube according to claim 5, wherein a pin is provided on each long side of the glass panel near the corner of the phosphor surface. 9. The color picture tube according to claim 1, wherein the scanning frequency ωv is 50 Hz or more. 10. The shadow grill extending method for a color picture tube according to claim 5, wherein a scanning frequency ωv for vertically scanning an electron beam;
The shadow grill is shifted such that the resonance frequency ωm of the shadow grill is shifted by a predetermined value Δω with respect to the ω value that satisfies Expression (1) defined by arbitrary integers n and N satisfying ≦ n and N ≦ 6. A shadow grill extension method characterized by being extended. ω = ωv · n / N (1) 11. An ω value satisfying the expression (1) is 400.
11. The shadow grill extending method according to claim 10, wherein when the frequency is equal to or lower than Hz, the resonance frequency ωm of the shadow grill is shifted within a range of a value Δω that satisfies Expression (2). 0 <Δω ≦ 2ωv / 3 (2) 12. The resonance frequency ωm of the shadow grill
The shadow grill extension method according to claim 10 or 11, wherein a value of the scanning frequency does not exceed the scanning frequency ωv. 13. A difference Δωm between resonance frequencies of a shadow grill corresponding to a center position and a peripheral position of the phosphor surface.
13 is set to a value smaller than the scanning frequency ωv.