JP2007073294A - Color picture tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent color shift due to deformation of a shadow mask when an external force is added. <P>SOLUTION: The shadow mask 50 has a generally rectangular aperture region 51 where a plurality of apertures 60 through which electron beams pass are formed. A plurality of apertures are provided side by side in a short side direction of the aperture region to form an aperture column, and a plurality of aperture columns are provided in a long side direction of the aperture region. If a pitch of the long side direction of the aperture is Ph, an aperture width in the long side direction of the aperture on a surface of the shadow mask on the side opposite a phosphor screen is W1, and a width in the long side direction of a non-formation region of the apertures obtained by Ph-W1 is K, a ratio α=K/Ph becomes larger gradually from the center of the aperture region to the periphery. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a color picture tube.

  In general, a color picture tube has an envelope including a face panel 31 and a funnel 32 integrally joined to the face panel 31, as shown in FIG. On the inner surface of the substantially rectangular face panel 31, a phosphor screen 33 made of a three-color phosphor layer in the form of stripes or dots emitting blue, green, and red is formed, facing this phosphor screen 33, A substantially rectangular shadow mask 50 having a perforated region in which a large number of apertures are formed is disposed. The shadow mask 50 is integrated and held on the mask frame 39 by a skirt 53 around the shadow mask 50. A shadow mask structure 34 including a shadow mask 50 and a mask frame 39 includes an elastic support (not shown) attached to the mask frame 39 and a stud pin (not shown) provided on the inner wall surface of the face panel 31. Is supported by the face panel 31. On the other hand, an electron gun 37 that emits three electron beams 36R, 36G, and 36B is disposed in the neck 35 of the funnel 32. The three electron beams 36R, 36G, and 36B emitted from the electron gun 37 are deflected by horizontal and vertical deflection magnetic fields generated by a deflection yoke 38 mounted outside the funnel 32, and pass through the aperture of the shadow mask 50 to fluoresce. A color image is displayed by scanning the body screen 33 horizontally and vertically. For convenience of the following description, as shown in the figure, the tube axis of the color picture tube is the Z axis, and the direction from the electron gun 37 toward the phosphor screen 33 (the direction of the arrow in FIG. 9) is a positive Z axis. Orient.

  The shadow mask 50 of such a color picture tube generally has a convex curved surface on the phosphor screen 33 side as shown in FIG. When the force for holding the curved surface shape (hereinafter referred to as “curved surface holding force”) is weak, the curved surface shape is deformed by an external force (for example, impact force, vibration, etc.) applied during manufacturing or transportation. . As a result, since the relative position of the aperture of the shadow mask 50 and the phosphor of the phosphor screen 33 changes, the electron beam that has passed through the aperture cannot enter the desired position of the phosphor screen 33. Causes a so-called color shift.

  The deformation of the curved shape of the shadow mask 50 by an external force is generally applied to the shadow mask 50 by a force toward the electron gun 37 in parallel with the tube axis direction of the color picture tube (that is, a force in the negative direction of the Z axis). Most likely to occur.

  Deformation and color shift of the shadow mask 50 when such a force acts on the shadow mask 50 will be described with reference to FIGS. In these drawings, the two-dot chain line indicates the shape of the shadow mask 50 before deformation.

  When the force F1 in the negative direction of the Z axis acts on the shadow mask 50, the shadow mask 50 is displaced as shown in FIG. At this time, as shown in FIG. 10B, a curved surface holding force F2 is applied to the shadow mask 50 in a direction opposite to the force F1 to return to the original state. If the magnitude of the curved surface holding force F2 is sufficient, the shadow mask 50 can return to the original state, and the curved shape of the shadow mask 50 is not deformed. However, when the curved surface holding force F2 is not sufficient, the shadow mask 50 cannot return to its original state as shown in FIG. Is deformed, resulting in a color shift.

  In order to prevent the deformation of the curved shape of the shadow mask 50, it is effective to generate a large curved surface holding force F2. For this purpose, it is preferable that the shadow mask 50 has a round dome shape with a small radius of curvature. However, with the recent flattening of the outer surface of the face panel 31, the inner surface of the face panel 31 is also flattened, and the curved shape of the shadow mask 50 needs to be flattened due to the characteristics of the color picture tube. In addition, when a tint glass material is used as the material of the face panel 31 in order to improve the tube surface color, since the transmittance is low, luminance uniformity is remarkably present when there is a difference in thickness between the center and the periphery of the screen. It will decline. Accordingly, it is necessary to reduce the thickness of the periphery of the screen, and thereby the inner surface of the face panel 31 is flattened, and as a result, the curved shape of the shadow mask 50 needs to be flattened as described above. Due to these circumstances, it is becoming difficult to prevent the deformation of the curved shape of the shadow mask 50 by rounding the curved shape of the shadow mask 50 and generating a large curved surface holding force F2.

  As another method for preventing the deformation of the curved shape of the shadow mask 50, it is conceivable to make the shadow mask 50 thick. This increases the rigidity of the shadow mask 50 and reduces the amount of displacement of the shadow mask 50 when the force F1 is applied. As a result, the curved shape of the shadow mask 50 is hardly deformed. However, increasing the thickness of the shadow mask 50 involves problems such as an increase in cost, a decrease in formability and shape accuracy, and difficulty in achieving high definition.

  Patent Document 1 discloses a color picture tube in which a plurality of non-through holes are formed in a perforated region of a shadow mask separately from the aperture, and the capacity of the hollow per unit area is maximized at the center of the shadow mask. Are listed. Thereby, since the weight per unit area of the shadow mask can be gradually reduced from the periphery toward the center, deformation of the curved shape of the shadow mask when an external force is applied can be suppressed. However, in this method, it is necessary to form a hollow hole separately from the aperture, which causes an increase in cost, and it is necessary to form the hollow hole at a position where it does not interfere with the aperture, which hinders high definition. .

Rather than providing a hollow hole separately from the aperture, the aperture width of the aperture is changed so as to become the maximum at the center of the shadow mask, and the weight per unit area of the shadow mask is changed from the periphery to the center as in the above-mentioned Patent Document 1. Even if it is gradually reduced toward, deformation of the curved shape of the shadow mask can be suppressed. However, with this method, the size of the electron beam spot formed on the phosphor screen becomes non-uniform, which causes problems such as deterioration in luminance uniformity.
JP 2003-16958 A

  As described above, if the curved shape of the shadow mask must be flattened by flattening the outer surface of the face panel and using tint glass as the face panel material, round the curved shape of the shadow mask. Thus, the method of increasing the curved surface holding force cannot be used. Other methods of color picture tubes include thickening the shadow mask and increasing the aperture aperture width at the center and decreasing it at the periphery to gradually reduce the weight per unit area of the shadow mask from the periphery to the center. The negative effect of worsening occurs. Furthermore, the method of providing a hollow hole separately from the aperture described in Patent Document 1 requires a work for forming a new hollow hole, and has a problem that it becomes an obstacle to high definition. Yes.

  The present invention solves the above problems of the conventional methods, and when an external force is applied, color misregistration due to deformation of the shadow mask is unlikely to occur, and as a result, a color image receiving device having good screen quality. The purpose is to provide a tube.

  The color picture tube of the present invention comprises a phosphor screen, an electron gun that emits an electron beam toward the phosphor screen, and a shadow mask disposed between the phosphor screen and the electron gun. The shadow mask has a substantially rectangular perforated region in which a plurality of apertures through which the electron beam passes are formed. The aperture shape of the aperture is a rectangular shape or a long hole shape in which the short side direction of the perforated region is the long axis direction, and a plurality of the apertures are arranged in the short side direction to form an aperture row, and the aperture A plurality of rows are arranged in the long side direction of the perforated region.

  The pitch of the aperture in the long side direction is Ph, and the aperture width in the long side direction of the aperture on the surface of the shadow mask facing the phosphor screen is determined by W1 and Ph-W1. Let K be the width of the formation region in the long side direction.

  The first color picture tube of the present invention is characterized in that the ratio α = K / Ph is gradually increased from the center to the periphery of the perforated region.

In the second color picture tube of the present invention, the ratio α = K / Ph
0.7 × (Phe− (t × tan (θ / 2) + W2e)) / Phe <α
<(Phe− (t × tan (θ / 2) + W2e)) / Phe
It is characterized by satisfying. However, Phe [mm] is the pitch of the aperture in the long side direction at the short side of the perforated region, and W2e [mm] is opposed to the electron gun of the shadow mask at the short side of the perforated region. The aperture width in the long side direction of the aperture on the side surface, t [mm] is the thickness of the shadow mask, and θ [°] is the deflection angle.

  According to the present invention, even if the curved shape of the shadow mask is flattened, deformation of the curved surface of the shadow mask due to external force applied in the manufacturing process and transportation process is unlikely to occur, and as a result, color shift due to deformation of the shadow mask is suppressed, Good screen quality can be obtained.

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

  The color picture tube of the present invention is not particularly limited except for the configuration of the shadow mask described below, and may have the same configuration as the color picture tube shown in FIG. 9, for example.

  FIG. 1 is a perspective view showing a state before a shadow mask 50 mounted on a color picture tube according to an embodiment of the present invention is held by a mask frame 39 (see FIG. 9). The shadow mask 50 includes a substantially rectangular main surface portion 57 formed on a predetermined curved surface, and a skirt portion 53 bent and provided on the negative side of the Z axis with respect to the main surface portion 57. The main surface portion 57 and the skirt portion 53 are connected via a bent portion 54. The main surface portion 57 includes a substantially rectangular perforated region 51 in which a large number of apertures through which electron beams pass are formed, and a non-perforated region 52 around the perforated region 51 where no aperture is formed. For convenience of the following description, an axis (long axis) orthogonal to the Z axis and parallel to the long side of the perforated region 51 is orthogonal to the X axis, X axis, and Z axis, and parallel to the short side of the perforated region 51. The short axis is the Y axis.

  FIG. 2 is a plan view of the state where the shadow mask 50 shown in FIG. 1 is developed on a plane, as viewed from the side facing the phosphor screen 33 (see FIG. 9). 3A is an enlarged plan view of the portion 3A of FIG. 2, FIG. 3B is an enlarged plan view of the portion 3B of FIG. 2, and FIG. 3C is a line 3C-3C of FIG. It is arrow sectional drawing. The portion 3A and the portion 3B are located at the center and the diagonal axis end of the perforated region 51, respectively.

  As shown in FIGS. 3A and 3B, when viewed from the normal direction of the shadow mask 50, the aperture shape of the aperture 60, which is a through-hole through which the electron beam passes, has a long axis in the Y-axis direction. The direction is a rectangular shape or a long hole shape. A plurality of apertures 60 are arranged side by side in the Y-axis direction to form an aperture row. A plurality of aperture rows are arranged in the X-axis direction. A region in which the apertures 60 are distributed in the X-axis direction and the Y-axis direction as described above is the perforated region 51.

  As shown in FIGS. 3 (A) and 3 (C), each aperture 60 has a small hole (portion forming the minimum hole diameter) 62 that can be seen through the opposite side when viewed from the normal direction of the shadow mask 50. From this, it consists of a large hole 61 on the phosphor screen 33 side. The opening widths of the small holes 62 in the X-axis direction and the Y-axis direction are W2 and H2. The opening widths in the X-axis direction and the Y-axis direction of the large hole 61 on the surface of the shadow mask 50 facing the phosphor screen 33 are W1 and H1 (W1> W2, H1> H2). When viewed from the normal direction of the shadow mask 50, the center of the large hole 61 is deviated in the X-axis direction and / or the Y-axis direction with respect to the center of the small hole 62 depending on the position of the aperture 60 in the perforated region 51. You may be mindful. Such an aperture 60 can be formed mainly by etching from the surface of the shadow mask 50 on the side facing the phosphor screen 33.

  In the present invention, as shown in FIG. 3 (A), the pitch in the X-axis direction of the aperture is Ph, and the aperture width in the X-axis direction of the aperture 60 on the surface of the shadow mask 50 facing the phosphor screen 33 (that is, , The opening width in the X-axis direction of the large hole 61) is W1, and the width in the X-axis direction of the non-formation region of the aperture 60 between the aperture rows adjacent in the X-axis direction (hereinafter referred to as “non-aperture region”) is K (K = When Ph−W1), it is preferable that the ratio α = K / Ph gradually increases from the center of the perforated region 51 toward the periphery.

  Accordingly, the weight per unit area of the shadow mask 50 is obtained without forming a hollow hole different from the aperture 60 described in the above-mentioned Patent Document 1 or impairing other characteristics of the color picture tube. Can be gradually reduced from the periphery of the perforated region 51 toward the center. As a result, it is possible to suppress deformation of the curved shape of the shadow mask when an external force is applied. This will be described below.

  In order to gradually reduce the weight per unit area of the shadow mask 50 from the periphery of the perforated region 51 toward the center without forming a hollow hole separate from the aperture 60, the X axis of the large hole 61 is used. The opening widths W1 and H1 in the direction and the Y-axis direction and the opening widths W2 and H2 in the X-axis direction and the Y-axis direction of the small hole 62 are gradually increased from the periphery of the perforated region 51 toward the center. I think it should be done.

  Consider a case where the opening widths H1 and H2 of the large hole 61 and the small hole 62 in the Y-axis direction are gradually increased from the periphery of the perforated region 51 toward the center. In general, a color picture tube has a lower brightness in the periphery than in the center of the screen. Therefore, when the opening widths H1 and H2 are gradually increased from the periphery of the perforated region 51 toward the center, the luminance difference between the center and the periphery of the screen is further increased. Therefore, in this case, the luminance characteristics of the color picture tube are remarkably deteriorated.

  Consider a case where the opening width W2 of the small hole 62 in the X-axis direction is gradually increased from the periphery of the perforated region 51 toward the center. In this case, the X-axis direction dimension of the electron beam spot formed on the phosphor screen changes. At the center of the screen, the electron beam passes through the small hole 62 having a relatively large opening width W2 and irradiates the phosphor screen, so that the electron beam spot 43 exceeds the black stripe 41 as shown in FIG. Irradiation of the adjacent phosphor stripe also causes other color strikes. Further, in the periphery of the screen, the electron beam passes through the small hole 62 having a relatively small opening width W2 and irradiates the phosphor screen, so that the dimension of the electron beam spot 43 in the X-axis direction is shown in FIG. Is narrower than the widths of the phosphor stripes 42R, 42G, and 42B that emit light in red, green, and blue colors, resulting in a lack of self-color. Thus, the desired screen characteristics of the color picture tube cannot be obtained.

  As described above, when the opening width H1 of the large hole 61 and the opening widths H2 and W2 of the small hole 62 are changed, various characteristics of the color picture tube are impaired. On the other hand, even if the opening width W1 of the large hole 61 in the X-axis direction is changed, as long as the electron beam 36 that has passed through the small hole 62 does not collide with the phosphor screen side end 61a of the large hole 61 as shown in FIG. The characteristics of the color picture tube are not impaired. In other words, even if the width K (= Ph−W1) of the non-aperture region in the X-axis direction gradually increases from the center to the periphery of the perforated region 51, the characteristics of the color picture tube are impaired. There is no.

  Therefore, the ratio α (= K / Ph), which is an indicator of the weight per unit area of the shadow mask 50, is gradually increased from the center of the perforated region 51 to the periphery, thereby reducing the weight of the shadow mask at the center. Thus, it is possible to realize a shadow mask whose curved surface shape is not easily deformed by a dynamic external force without impairing various characteristics of the color picture tube.

  Since the X-axis direction dimension of the main surface portion 57 (see FIG. 1) of the shadow mask 50 is longer than the Y-axis direction size, the curved surface holding force of the main surface portion 57 held by the mask frame 39 is X-axis direction. Is smaller than the Y-axis direction. Therefore, changing the ratio α relating to the dimension in the X-axis direction as described above has a great effect on suppressing the deformation of the curved shape of the shadow mask 50. Further, since the change in the ratio α is gentle, it is possible to prevent stress from being concentrated locally and to further suppress deformation.

  In short, the ratio α of the non-aperture region width K to the pitch Ph in the X-axis direction of the aperture is gradually increased from the center to the periphery of the perforated region 51 without impairing various characteristics of the color picture tube. The deformation of the curved shape of the shadow mask 50 can be suppressed. In the present invention, the opening width H1 of the large hole 61 and the opening widths H2 and W2 of the small hole 62 have almost no difference between the center and the periphery of the perforated region 51 in order to ensure various characteristics of the color picture tube. Therefore, the weight per unit area of the shadow mask 50 can be accurately controlled by changing the ratio α as described above.

  In the present invention, the ratio α is preferably substantially uniform at the periphery of the perforated region 51. For example, if the ratio α at the X-axis end 51H and the Y-axis end 51V (see FIG. 2) of the perforated region 51 is significantly different from each other, the amount of displacement of the shadow mask when an external force is applied is different from the X-axis end 51H. This is because the stress differs from the Y-axis end 51V, and local stress acts. In other words, since the ratio α is substantially uniform at the periphery of the perforated region 51, the displacement amount at any position on the periphery is substantially the same, so that the curved surface holding force acts substantially uniformly on the entire shadow mask 50. Thus, the deformation of the curved surface shape can be further suppressed. Here, the “periphery” means the entire circumference including a pair of long sides and a pair of short sides of the substantially rectangular perforated region 51. The fact that the ratio α is “substantially uniform” at the periphery of the perforated region 51 includes a dimensional error that occurs due to manufacturing variation and the like. Specifically, the ratio α has a minimum value and a maximum value. The difference is preferably within 0.03.

  The deformation of the curved shape of the shadow mask can also be suppressed by defining the range of the ratio α.

  First, consider the maximum value αmax of the ratio α. αmax can be determined by considering the minimum value W1min of the opening width W1 of the large hole 61 so that the electron beam 36 that has passed through the small hole 62 of the aperture 60 does not collide with the phosphor screen side end 61a of the large hole 61. When the opening width W1 is smaller than the minimum value W1min, the electron beam 36 that has passed through the small hole 62 collides with the phosphor screen side end 61a of the large hole 61, and an appropriate electron beam spot can be formed on the phosphor screen. As a result, the characteristics of the color picture tube deteriorate. The collision of the electron beam 36 with the phosphor screen side end 61a of the large hole 61 is caused by the short side of the perforated region 51 having a large incident angle to the shadow mask 50 (particularly the diagonal axis where the short side and the long side intersect). It tends to occur at the edge).

  6 is a cross-sectional view showing the electron beam 36 incident on the aperture 60 at the diagonal axis end 51D (see FIG. 2) of the perforated region 51. As shown in FIG. In this figure, the minimum value W1min of the opening width W1 of the large hole 61 so that the electron beam 36 does not collide with the phosphor screen side end 61a of the large hole 61 is obtained.

  The distance Δ1 [mm] that the electron beam 36 moves in the X-axis direction after the electron beam 36 enters the small hole 62 and passes through the shadow mask 50 having a thickness t [mm] is the distance of the electron beam 36. When the deflection angle is θ [°], Δ1 = t × tan (θ / 2) [mm]. The sum of Δ1 [mm] and the opening width W2e [mm] of the small hole 62 is the minimum value W1min [mm] of the opening width W1 of the large hole 61. Therefore, the minimum value W1min [mm] of the opening width W1 of the large hole 61 so that the electron beam 36 does not collide with the phosphor screen side end 61a of the large hole 61 is W1min = Δ1 + W2e = t × tan (θ / 2) + W2e [mm]. ].

When the opening width W1 of the large hole 61 is the minimum, the X-axis direction width K of the non-aperture region is the maximum value Kmax, and the ratio α is also the maximum. Therefore, the maximum value αmax of the ratio α for preventing the characteristics of the color picture tube from deteriorating is given by assuming that the pitch in the X-axis direction of the aperture at the diagonal axis end of the perforated region 51 is Phe [mm].
αmax = (Phe−W1min) / Phe
= (Phe− (t × tan (θ / 2) + W2e)) / Phe
It becomes. That is, if the ratio α is less than αmax, the electron beam 36 that has passed through the small hole 62 will not collide with the phosphor screen side end 61a of the large hole 61, and therefore the characteristics of the color picture tube will not be impaired. .

  Next, consider the minimum value αmin of the ratio α. αmin can be determined by considering the value of the ratio α necessary to withstand a static external force. As described in the Background section, the method of gradually reducing the weight per unit area of the shadow mask 50 from the periphery toward the center is generated when a dynamic external force such as an impact force or vibration is applied. Since the inertial force to be reduced can be reduced, there is an effect of reducing the amount of displacement of the shadow mask. In general, a dynamic external force is applied to the shadow mask of a color picture tube. However, in the manufacturing process, a static external force such as pressure may be applied, such as when the shadow mask passes through a gas atmosphere. is there. In such a case, when the weight per unit area of the shadow mask 50 is suddenly reduced at the center with respect to the periphery of the perforated region 51, a curved surface holding force is sufficiently generated against a static external force acting slowly. However, the center of the perforated region 51 may remain deformed. Therefore, by defining the minimum value αmin of the ratio α in relation to αmax, the weight per unit area of the shadow mask 50 is limited so as not to change abruptly in the perforated region 51, and the gas in the manufacturing process is limited. A shadow mask that is not deformed by the atmosphere or the like can be realized.

  FIG. 7 is a diagram showing the relationship between the strength of the shadow mask and the defect rate with respect to static pressure, measured using several types of color picture tubes. The “defective rate” on the vertical axis in FIG. 7 is the defective rate of a shadow mask that has been deformed due to an impact or gas pressure during transportation in the shadow mask assembly process. The “mask strength” means a limit strength with which the shadow mask can maintain a curved surface against a static pressure. FIG. 7 shows that the defect rate is stabilized at a low level when the strength of the shadow mask with respect to static pressure is about 70 Pa or more.

  Therefore, for the 76cm and 86cm color picture tubes, which are very large tubes that are generally sensitive to static pressure, the ratio of α to αmax α / αmax is changed to measure the strength of the shadow mask against static pressure. did. The results are shown in FIG. FIG. 8 shows that the ratio α / αmax> 0.7 must be satisfied in order that the strength of the shadow mask with respect to static pressure is 70 Pa or more. That is, by setting the minimum value αmin of α to 0.7 × αmax, a shadow mask that is resistant to static external force can be realized.

From the above, the ratio α is
0.7 × (Phe− (t × tan (θ / 2) + W2e)) / Phe <α
<(Phe− (t × tan (θ / 2) + W2e)) / Phe
Is preferably satisfied.

  As described above, according to the present invention, the curved shape of the shadow mask must be flattened by flattening the outer surface of the face panel or by using a tint glass material as the face panel material. Even so, it is possible to ensure the curved-surface holding force of the shadow mask without rounding the curved shape of the shadow mask or providing a hollow hole separately from the aperture. As a result, color shift due to deformation of the shadow mask is unlikely to occur, and stable and good screen quality can be obtained.

  An example in which the present invention is applied to a 76 cm color picture tube will be described. Since the material of the face panel of the color picture tube is a tint glass material and the outer surface of the face panel is almost flat, the shadow mask must be flat. Therefore, it is difficult to secure the curved-surface holding force of the shadow mask with the conventional method.

  As a comparative example, a color picture tube using a shadow mask having a ratio α in the center of the perforated region of 0.34 and no distribution in the ratio α in the perforated region was prepared. This color picture tube was subjected to a drop test with the face panel side facing up and the height gradually increased. As a result, the shadow mask was deformed at a drop height of 20 cm.

  As an embodiment according to the present invention, a color picture tube using a shadow mask in which the ratio α at the center of the perforated region is 0.34 and the ratio α gradually increases from the center to the periphery of the perforated region. It was created. This shadow mask will be described in detail. In the perforated region, the maximum value of the ratio α was 0.39 at the minor axis end. The value of the ratio α at the periphery of the effective area was 0.38 to 0.39 and was almost uniform. The thickness t of the shadow mask is 0.25 mm, the deflection angle θ is 102 °, the pitch Phe in the X-axis direction of the aperture is 0.83 [mm] at the diagonal axis end of the perforated region, and the aperture hole 62 is opened. The width W2e was 0.19 [mm]. Therefore, (phe− (t × tan (θ / 2) + W2e)) / phe = 0.40, and 0.7 × 0.4 = 0.28 <α <0.40 was satisfied. Therefore, it is strong against static external force, and the electron beam does not collide with the phosphor screen side end 61a (see FIG. 5) of the large hole. The color picture tube according to this example was subjected to a drop test similar to that of the comparative example. As a result, the shadow mask was not deformed even when the drop height was 20 cm. In other words, in the example, a shadow mask resistant to external force could be realized without impairing various characteristics of the color picture tube.

  The position where the ratio α is maximum is the short axis end in the above-described embodiment, but the present invention is not limited to this. The position where the ratio α is maximum may be other than the short axis end, and is preferably on the periphery of the perforated region.

Moreover, in said Example, although the ratio (alpha) had the distribution which becomes large gradually as it goes to the periphery from the center of a perforated area | region, this invention is not limited to this. Even if the ratio α does not have the distribution,
0.7 × (Phe− (t × tan (θ / 2) + W2e)) / Phe <α
<(Phe− (t × tan (θ / 2) + W2e)) / Phe
If the above condition is satisfied, it is possible to realize a shadow mask that does not impair various characteristics of the color picture tube and is strong against static external force. That is, color shift due to deformation of the shadow mask hardly occurs, and as a result, a color picture tube having good screen quality can be realized.

  The field of application of the present invention is not particularly limited, but the present invention is particularly useful for a color picture tube having a face panel having a substantially flat outer surface with a radius of curvature of 10,000 mm or more and a face panel using a tint glass material. large. Further, since it is not necessary to form a hollow hole separately from the aperture in the shadow mask, it can be used for a color picture tube corresponding to high definition.

  Here, the “tint color glass material” refers to a glass material having a spectral transmittance of 60% or less of light having a wavelength of 546 nm at a thickness of 10.16 mm.

It is a perspective view of the shadow mask mounted in the color picture tube which concerns on one Embodiment of this invention. FIG. 2 is a plan development view of the shadow mask shown in FIG. 1. 3A is an enlarged plan view of the portion 3A of FIG. 2, FIG. 3B is an enlarged plan view of the portion 3B of FIG. 2, and FIG. 3C is a line 3C-3C of FIG. It is arrow sectional drawing. FIG. 4A is a diagram showing a relationship between a phosphor stripe formed on a phosphor screen and an electron beam spot. FIG. 4A shows a case where the X-axis direction width of the electron beam spot is relatively large, and FIG. B) shows a case where the X-axis direction width of the electron beam spot is relatively small. It is sectional drawing which showed the collision of the electron beam to the phosphor screen side end of the large hole of an aperture. It is sectional drawing which showed the electron beam which injects into an aperture in the diagonal axis | shaft end of a perforated area | region. It is the figure which showed the relationship between the strength of a shadow mask with respect to static pressure, and a defect rate. It is the figure which showed the relationship between (alpha) / (alpha) max and the strength of the shadow mask with respect to a static pressure. It is sectional drawing which showed the whole structure of the general color picture tube. FIGS. 10A to 10B are diagrams illustrating the behavior of the shadow mask when an external force is applied to the shadow mask.

Explanation of symbols

31 Face panel 32 Funnel 33 Phosphor screen 34 Shadow mask structure 35 Neck 36R, 36G, 36B Electron beam 37 Electron gun 38 Deflection yoke 39 Mask frame 50 Shadow mask 51 Perforated region 52 Non-perforated region 53 Skirt portion 54 Bending portion 57 Main Face part 60 Aperture 61 Large hole 62 Small hole

Claims (9)

A color picture tube comprising: a phosphor screen; an electron gun that emits an electron beam toward the phosphor screen; and a shadow mask disposed between the phosphor screen and the electron gun;
The shadow mask has a substantially rectangular perforated region in which a plurality of apertures through which the electron beam passes are formed;
The aperture shape of the aperture is a rectangular shape or a long hole shape in which the short side direction of the perforated region is the long axis direction, and a plurality of the apertures are arranged in the short side direction to form an aperture row, and the aperture A plurality of rows are arranged in the long side direction of the perforated region,
The pitch of the aperture in the long side direction is Ph, and the aperture width in the long side direction of the aperture on the surface of the shadow mask facing the phosphor screen is determined by W1 and Ph-W1. A color picture tube, wherein the ratio α = K / Ph gradually increases from the center to the periphery of the perforated region, where K is the width in the long side direction of the formation region.   The color picture tube according to claim 1, wherein the ratio α is substantially uniform at the periphery of the perforated region. The ratio α is
0.7 × (Phe− (t × tan (θ / 2) + W2e)) / Phe <α
<(Phe− (t × tan (θ / 2) + W2e)) / Phe
The color picture tube according to claim 1, which satisfies the following conditions.
However, Phe [mm] is the pitch of the aperture in the long side direction at the short side of the perforated region, and W2e [mm] is opposed to the electron gun of the shadow mask at the short side of the perforated region. The aperture width in the long side direction of the aperture on the side surface, t [mm] is the thickness of the shadow mask, and θ [°] is the deflection angle.   The color picture tube according to claim 1, wherein a material of the face panel includes a tint glass material.   2. The color picture tube according to claim 1, wherein a radius of curvature of an outer surface of the face panel is 10,000 mm or more. A color picture tube comprising a phosphor screen, an electron gun that emits an electron beam toward the phosphor screen, and a shadow mask disposed between the phosphor screen and the electron gun,
The shadow mask has a substantially rectangular perforated region in which a plurality of apertures through which the electron beam passes are formed;
The aperture shape of the aperture is a rectangular shape or a long hole shape in which the short side direction of the perforated region is the long axis direction, and a plurality of the apertures are arranged in the short side direction to form an aperture row, and the aperture A plurality of rows are arranged in the long side direction of the perforated region,
The pitch of the aperture in the long side direction is Ph, and the aperture width in the long side direction of the aperture on the surface of the shadow mask facing the phosphor screen is determined by W1 and Ph-W1. When the width in the long side direction of the formation region is K, the ratio α = K / Ph is
0.7 × (Phe− (t × tan (θ / 2) + W2e)) / Phe <α
<(Phe− (t × tan (θ / 2) + W2e)) / Phe
A color picture tube characterized by satisfying
However, Phe [mm] is the pitch of the aperture in the long side direction at the short side of the perforated region, and W2e [mm] is opposed to the electron gun of the shadow mask at the short side of the perforated region. The aperture width in the long side direction of the aperture on the side surface, t [mm] is the thickness of the shadow mask, and θ [°] is the deflection angle.   The color picture tube according to claim 6, wherein the ratio α is substantially uniform at the periphery of the perforated region.   The color picture tube according to claim 6, wherein the material of the face panel includes a tint glass material.   The color picture tube according to claim 6, wherein a radius of curvature of an outer surface of the face panel is 10,000 mm or more.

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