JP3926372B2 - Cathode ray tube - Google Patents

Description

  The present invention relates to a cathode ray tube equipped with a deflection yoke, and in particular, a cathode ray capable of effectively reducing the deflection power and securing the pressure resistance strength of the vacuum envelope while suppressing the collision of the electron beam with the funnel cone. Regarding the tube.

  An example of a conventional cathode ray tube will be described with reference to FIGS. FIG. 16 shows a perspective view of an example of a vacuum envelope used in a conventional cathode ray tube. FIG. 17 is a perspective view showing an example of the internal structure of a conventional cathode ray tube. The vacuum envelope 1 includes a glass panel 2 having a substantially rectangular display portion, a funnel-shaped glass funnel 3 having a large diameter connected to the panel 2, and a cone portion 4 of the funnel 3. A cylindrical glass neck 5 is provided.

  A phosphor screen 6 formed of a phosphor layer is provided on the inner surface of the panel 2. The phosphor layer is a three-color phosphor layer in the form of dots or stripes that emit blue, green, and red. A shadow mask 7 is disposed opposite to the phosphor screen 6. A large number of electron beam passage holes are formed in the shadow mask 7. An electron gun 8 that emits three electron beams is disposed in the neck 5.

  A deflection yoke 9 is mounted from the outside of the cone portion 4 of the funnel 3 to the outside of the neck 5. The three electron beams are deflected by horizontal and vertical deflection magnetic fields generated by the deflection yoke 9, and a color image is displayed by scanning the phosphor screen 6 horizontally and vertically via the shadow mask 7. Become.

  As the cathode ray tube, a self-convergence in-line type cathode ray tube has been widely put into practical use. In this cathode ray tube, the electron gun 8 is an in-line type that emits three electron beams arranged in a row passing through the same horizontal plane. The horizontal deflection magnetic field generated by the deflection yoke 9 is a pin cushion type, the vertical deflection magnetic field is a barrel type, and three electron beams arranged in a row are deflected by these horizontal and vertical deflection magnetic fields, thereby making a special correction. Without requiring any means, three electron beams arranged in a line are concentrated on the entire screen.

  In such a cathode ray tube, the deflection yoke 9 is a large power consumption source, and in reducing the power consumption of the cathode ray tube, it is important to reduce the power consumption of the deflection yoke 9. That is, in order to increase the brightness of the screen, it is necessary to increase the anode voltage for finally accelerating the electron beam. Further, in order to cope with OA equipment such as HD (High Definition) TV and personal computer, the deflection frequency must be increased, but both of these increase the deflection power.

  In general, in order to reduce the deflection power, the diameter of the neck 5 of the cathode ray tube is reduced and the outer diameter of the cone portion 4 to which the deflection yoke 9 is attached is reduced so that the deflection magnetic field acts efficiently on the electron beam. It is good to do. In this case, the electron beam passes close to the inner surface of the cone portion 4 on which the deflection yoke 9 is mounted. For this reason, when the diameter of the neck 5 and the outer diameter of the cone portion 4 are further reduced, the electron beam directed to the diagonal portion of the phosphor screen 6 having the maximum deflection angle collides with the inner wall of the cone portion 4 of the funnel 3 to cause fluorescence. On the body screen 6, there arises a problem that a phenomenon that the electron beam does not reach partially (hereinafter referred to as “beam neck shadow”) occurs due to the shadow of the inner wall of the funnel 3.

  As a means for solving such a problem, in Patent Document 1, when a rectangular raster is drawn on the phosphor screen 6, an electron beam passage region inside the cone portion 4 is also substantially rectangular, The cone part 4 to which the deflection yoke 9 is attached has been proposed in a shape that gradually changes from a circular shape to a substantially rectangular shape in the direction of the panel 2 from the neck 5 side.

  When the cone portion 4 to which the deflection yoke 9 is attached is formed in a pyramid shape, the cone portion 4 has a diagonal portion (near the diagonal axis: near the D axis) that is likely to collide with an electron beam. ) Can be increased to avoid collision of electron beams. Furthermore, by reducing the inner diameter in the horizontal axis (H axis) and vertical axis (V axis) directions, the horizontal and vertical deflection coils of the deflection yoke can be brought closer to the electron beam, so that the electron beam can be efficiently deflected, and the deflection power Can be reduced.

  FIG. 18 shows the state of the action of stress when the cone portion 4 is made close to a rectangle. As the cone portion 4 becomes closer to a rectangle, as shown in FIG. 18, a distortion that deforms as shown by the broken line 117 occurs in the cone portion 4 flattened by the atmospheric pressure load F. At this time, the compressive stresses σH and σV act on the outer surfaces near the horizontal axis 115 and the vertical axis 116, respectively, and the tensile stress σD acts on the outer surface near the diagonal axis 118. When such a stress acts, there is a problem that the pressure resistance strength of the vacuum envelope is lowered and reliability (safety) with respect to atmospheric pressure is impaired.

  In recent years, there have been strong demands for prevention of external light reflection and easy viewing of images, and flat paneling has become essential. When the panel is flattened, it becomes weak against atmospheric pressure load. Therefore, if it is attempted to reduce the deflection power by using a funnel in which a pyramid-shaped cone portion is provided on a flattened cathode ray tube of the panel, it is impossible to ensure the pressure resistance strength.

  As means for solving such a problem, there is one proposed in Patent Document 2. FIG. 19 shows a cross-sectional view of the cone portion in Patent Document 2 in the direction perpendicular to the tube axis. The cross-sectional shape shown in FIG. 19 forms a non-circular shape having an outer diameter with the maximum thickness on the horizontal and vertical axes.

  In this cross section, Pi (θ) is a point where a straight line passing through the tube axis at an angle θ with respect to the horizontal axis intersects the inner surface of the cone portion, and the distance from this point Pi (θ) to the horizontal axis is Piv (θ), vertical. Assuming that the distance to the axis is Pih (θ), Piv (θ) or Pih (θ) is in the tube axis direction represented by a non-monotonically increasing or decreasing function having at least one maximum value between the horizontal and vertical axes. It has a convex part. As a result, the shape of the inner surface of the cone portion in a cross section perpendicular to the tube axis is formed into a pin cushion shape that approximates the pin cushion-shaped electron beam passage region in the cone portion.

Further, Patent Document 3 proposes a configuration that can secure the pressure resistance strength and can effectively reduce the deflection power even if the cone portion is pyramidal. In this configuration, when the screen aspect ratio is M: N, the vertical axis direction outer diameter is SA, the horizontal axis direction outer diameter is LA, and the maximum cone portion (diagonal axis direction) outer diameter is DA, (M + N) / (2 X (M ² + N ² ) ^1/2 ) <(SA + LA) / (2 × DA) ≦ 0.86

  Further, in Patent Document 4, when the electron beam is substantially deflected by the deflection yoke, there is a relative deflection margin in the minor axis V direction rather than the major axis H and diagonal portion D directions of the panel. A configuration that takes into account is proposed. Specifically, in the cross-sectional shape perpendicular to the tube axis of the cone portion, when the thickness of the cone portion is Tv in the long axis direction of the panel, Th in the short axis direction of the panel, and Td in the diagonal direction of the panel, To satisfy the formula.

Tv (z)> Th (z)> Td (z)
Japanese Patent Publication No. 48-34349 (U.S. Pat. No. 3,731,129) Japanese Patent Laid-Open No. 10-154472 JP-A-10-149785 JP 2000-149828 A

  However, there is a problem that has been neglected in the cathode ray tube. This will be described with reference to FIGS. 20A is a sectional view of an example of a conventional cathode ray tube, and FIG. 20B is a plan view of a panel screen of the cathode ray tube shown in FIG. 20A. FIG. 21 is a view of a cross section perpendicular to the tube axis of the cone portion 4 as viewed from the screen 6 side. Reference numeral 20 denotes a connecting portion on the screen side of the cone portion 4, 21 denotes a reference line position of the cone portion 4, and 22 denotes each shape of the connecting portion on the neck side of the cone portion 4.

  In general, the standard range in which the electron beam is scanned by the NTSC method is expanded to a range of 108% with respect to the image range of the phosphor screen 6 shown in FIG. 20B (maximum screen diameters 6a and 6b in the diagonal direction). When an image is displayed, an electron beam collides with the diagonal axis vicinity 33 (FIG. 20A, FIG. 21) of the inner surface of the cone part 4.

  This colliding electron beam is reflected and causes a scattered beam 31 (FIG. 20A) in a trajectory different from the predetermined deflection trajectory of the electron beam. In this case, a phenomenon occurs in which the scattered beam 31 collides with the entire phosphor screen 6 and reaches the phosphor screen 6 without distinguishing between red, green, and blue on the phosphor screen 6, and emits a low-luminance white color on the entire screen. The contrast and color purity of black and white are lowered.

  For example, when the entire screen is displayed in green, the scattered beam 31 does not pass through a predetermined trajectory and reaches the phosphor screen without distinction of red, green, and blue, and the entire screen emits white with low luminance. . For this reason, the predetermined green display is green with reduced color purity.

  This phenomenon is called the halation phenomenon, and it is recognized most prominently when viewing images in a dark room, and is an important issue in providing high-definition images through digital hi-vision in recent years. Yes.

  In the above-mentioned cathode ray tube, in order to prevent halation, it is necessary to increase the distance to the inner wall of the cone portion, particularly in the vicinity of the diagonal axis, and to secure a sufficient margin for the electron beam more than the margin where the beam neck shadow does not occur. There is. For this reason, the thickness in the vicinity of the diagonal axis of the cross-sectional shape perpendicular to the tube axis of the cone portion is reduced, and the pressure resistance strength of the vacuum envelope is deteriorated. Further, if the outer wall in the vicinity of the diagonal axis is increased from the tube axis of the cone portion, the efficiency of the deflection magnetic field with respect to the electron beam is reduced, leading to an increase in deflection power.

  The present invention has been made to solve the conventional problems as described above, and can effectively reduce the deflection power while preventing halation and sufficiently ensure the pressure resistance strength of the vacuum envelope. An object is to provide a high-quality cathode ray tube.

In order to achieve the above object, a cathode ray tube according to the present invention is disposed on a vacuum envelope including a panel portion in which an electron gun is embedded and a phosphor screen is formed on an inner surface, and on the outer periphery of the vacuum envelope. A cathode ray tube comprising a deflection yoke for deflecting an electron beam emitted from the electron gun, wherein the vacuum envelope is provided at a position where the neck portion for housing the electron gun and the deflection yoke are disposed. Correspondingly, the cross-sectional shape in the direction perpendicular to the tube axis of the cathode ray tube includes a non-circular cone portion in substantially the entire region of the tube axis direction, and the panel portion has a major axis and a minor axis orthogonal to each other. Of the cross-sectional shape of the cone portion in the direction perpendicular to the tube axis, Th is the substantial thickness on the major axis and Th is the substantial thickness on the minor axis. the Tv, When Td minimum thickness in the diagonal position, and the reference deflection angle That from said reference line position in various positions on the tube axis in the range of up to an end portion of the panel portion side of the cone cross-sectional shape is, Th>Tv> satisfy the Td relationship, and in the range Has a maximum value of Th / Tv .

  According to the present invention, it is possible to provide a high-quality cathode ray tube capable of effectively reducing the deflection power while preventing halation and sufficiently ensuring the pressure resistance strength of the vacuum envelope.

In the present invention, the thickness Th on the major axis, the thickness Tv on the minor axis, and the minimum thickness Td at the diagonal position satisfy the relationship of Th>Tv> Td, thereby preventing halation. On the other hand, it is possible to provide a high-quality cathode ray tube capable of effectively reducing the deflection power and sufficiently ensuring the pressure resistance strength of the vacuum envelope.
Further, the cross-sectional shape at each position on the tube axis in the range from the reference line position serving as a reference for the deflection angle to the end of the cone portion on the panel portion side satisfies the relational expression of Th>Tv> Td. In addition, since there is a maximum value of Th / Tv within the above range, the effect of ensuring the pressure resistance strength of the vacuum envelope while preventing halation is further ensured.

In the cathode ray tube of the present invention, from the reference line position serving as a reference for the deflection angle, within a range of up to 85% of the distance between the reference line position and the end of the cone part on the panel part side , it is preferable to satisfy the T h / Tv ≧ 1.1. According to this configuration, it is more advantageous to ensure the pressure resistance strength.

In the cross-sectional shape satisfying the relational expression, the substantial thickness in the major axis direction on the axis obtained by translating the major axis by the distance L is Th ′, and the minor axis is the same as the distance L. The substantial thickness in the minor axis direction on the axis translated by the distance is Tv ′, and when the distance L is increased from 0, the above condition satisfying Th ′> Tv ′ is satisfied at any distance L. Preferably, there is a range of cross-sectional areas. According to this configuration, molding is easy and the stress distribution becomes smooth.

  Moreover, it is preferable that Th / Tv ≧ 1.2 is satisfied, and the range of the region is a range smaller than 17 mm from each axis.

  Moreover, it is preferable that Th / Tv> 1.1 is satisfied, and the range of the region is within a range of 10 mm or less from each axis.

  The maximum value is preferably 1.11 or more and 1.39 or less. According to this configuration, it is possible to prevent a decrease in pressure resistance strength due to Tv being too thin compared to Th.

  In addition, in the cross-sectional shape of the cone portion in the direction perpendicular to the tube axis, among the points on the inner surface in the vertical direction of the cone portion, the point farthest from the tube axis in the horizontal direction is rdh, and the horizontal of the cone portion is Among the points on the inner surface in the direction, the point farthest from the tube axis in the vertical direction is the vertical maximum from the vertical line passing through rdv and rdh, the horizontal maximum height on the inner surface in the vertical direction is ΔH, from the horizontal line passing through rdv When the vertical maximum height on the inner surface in the horizontal direction is ΔV, the cross-sectional shape at each position on the tube axis in the range from the reference line position to the end portion on the panel portion side of the cone portion is: It is preferable that the relationship of ΔH> ΔV is satisfied. According to this configuration, it is possible to prevent the electron beam from hitting the inner wall near the minor axis while preventing the electron beam from hitting the diagonal inner wall of the cone portion.

  Further, in a range from a substantially middle position in a range from the reference line position to the end of the cone portion on the panel portion side to an end portion of the cone portion on the panel portion side, a value of ΔH−ΔV is a value of the panel. It is preferable that it increases as it approaches the part side. In this configuration, the collision of the electron beam to the inner wall of the diagonal portion is more reliably prevented by increasing the value of ΔH−ΔV in the range where the trajectory of the electron beam is shifted toward the horizontal axis.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The basic configuration shown in FIGS. 16 and 17 is the same in this embodiment. That is, the cathode ray tube includes a rectangular panel 2 having a horizontal axis (H axis) as a major axis and a vertical axis (V axis) as a minor axis, a funnel-shaped funnel 3 connected to the panel 2, and a funnel 3 It is comprised by the vacuum envelope 1 containing the cylindrical neck part 5 provided in a row. A deflection yoke 9 is attached to the cone portion 4 that extends from the continuous portion with the neck portion 5 toward the panel 2 side in the outer peripheral portion of the funnel 3. A phosphor screen 6 is formed on the inner surface of the panel 2, and an electron gun 8 is inserted and installed inside the neck portion 5.

  FIG. 1 is a sectional view of a cathode ray tube according to an embodiment of the present invention. FIG. 2 is a plan view of the panel 2 of the cathode ray tube shown in FIG. A deflection yoke 9 is mounted on the outer periphery of the funnel 3, and a portion of the funnel 3 where the deflection yoke 9 is mounted is a cone portion 4. Lines 20 and 22 are lines indicating the positions of the end portions of the cone portion 4 in the tube axis 1a direction, and are connecting portions of the cone portion 4 and other portions. Hereinafter, the line 20 indicating the end portion on the panel 2 side of the cone portion 4 is referred to as a connecting portion 20, and the line 22 indicating the end portion of the cone portion 4 on the electron gun 8 side is referred to as a connecting portion 22.

  The panel 2 is symmetric with respect to a horizontal axis 2a (H axis) and a vertical axis 2b (V axis) which are orthogonal to each other. The three electron beams emitted from the electron gun 8 are deflected by the deflection yoke 9 in the horizontal axis 2a and vertical axis 2b directions of the panel 2. The electron beam passes through the electron beam passage hole of the shadow mask 7 installed inside the panel 2 and is landed on the phosphor screen 6 to realize a predetermined image.

  The cathode ray tube has a deflection angle φ corresponding to the model. The deflection angle is related to the reference line 21 (deflection reference position). The reference line is an angle formed by two straight lines connected to an arbitrary point on the tube axis 1a (Z axis) from the diagonal ends 6a and 6b (FIG. 2) of the phosphor screen 6 and the deflection angle of the cathode ray tube. It is a line that passes through a point 19 (deflection center) on the tube axis that is the same as φ and is orthogonal to the tube axis 1a.

  Normally, when designing the funnel 3, the reference line 21 is determined according to the screen size in consideration of the deflection angle φ. In this case, even if the deflection angle φ is the same, the position of the reference line 21 is different if the screen size is different. However, when the deflection angle φ is given, the screen size of one cathode ray tube is fixed, so that one reference line 21 is always obtained uniquely.

  The reference line is defined by the deflection angle of the cathode ray tube as described above, and the position of the reference line can be obtained by mounting a standardized reference line gauge on the neck portion 5. it can.

  Next, FIGS. 3A, 3B, and 3C are cross-sectional views in the direction perpendicular to the tube axis of the vacuum envelope 1 shown in FIG. 3A is a cross-sectional view in the vicinity of the continuous portion 22, FIG. 3B is a cross-sectional view in the position of the reference line 21, and FIG. 3C is a cross-sectional view in the vicinity of the continuous portion 20. As can be seen from these drawings, the cone portion 4 to which the deflection yoke 9 is attached is formed in a substantially pyramid shape. That is, the cross-sectional shape in the direction orthogonal to the tube axis 1a of the vacuum envelope 1 is a circular shape that is substantially the same shape as the neck portion 5 in the vicinity of the connecting portion 22, as shown in FIG. As shown in FIG. 3, the reference line 21 and the continuous portion 20 shown in FIG. 3C are formed in a substantially rectangular shape (non-circular shape). 3A, 3B, and 3C illustrate that the cross-sectional shape orthogonal to the tube axis is a shape close to a rectangle in the cone portion compared to a circle in the connecting portion 22 with the neck. It is only a simplified diagram. A more specific shape will be described later.

  Here, the background to the present invention will be described with reference to FIGS. FIG. 4 is a diagram assuming that the inner surface or the outer surface is the simplest shape when examining a specific cone portion shape. The cone part 4 includes a horizontal axis 2a of the phosphor screen, an arc 25 having a radius Rh centered on the horizontal axis 2a, and a vertical axis 2b and a vertical axis of the phosphor screen, except for the vicinity of the connecting part with the neck. An arc 26 having a radius Rv centered on 2b and an arc 27 having a radius Rd centered on the diagonal axis 2c (D-axis) and smoothly connected to the arcs 25, 26.

  When the distance from the tube axis in the horizontal axis 2a direction is LA, the distance in the vertical axis 2b direction is SA, and the distance that is the maximum diameter in the diagonal axis 2c direction is DA, LA and SA are smaller than DA. It is formed in a substantially rectangular shape.

  FIG. 5 is a diagram showing the trajectory path of the electron beam passing through the area of the cone portion 4. In FIG. 5, a line connecting the horizontal axis 2 a and the vertical axis 2 b represents the inner surface shape of the cross-sectional shape in the direction perpendicular to the tube axis in the cone portion 4 of the vacuum envelope 1. For example, the line 70 indicates the inner surface shape of the connecting portion 22 (FIG. 1), the line 71 indicates the inner surface shape of the reference line 21 (FIG. 1), and the line 72 indicates the inner surface shape of the connecting portion 20 (FIG. 1).

  A dotted line 30 indicates the trajectory path of the electron beam passing through the region of the cone portion 4 when the electron beam reaches the diagonal end 6a of the phosphor screen 2 as shown in FIG. More specifically, it is a trajectory obtained by projecting the trajectory of the electron beam onto a plane parallel to the phosphor screen 2. For example, the point 74 represents the position of the electron beam in the vicinity of the reference line 21, and the point 75 represents the position of the electron beam in the vicinity of the connecting portion 20. As shown in FIG. 5, it can be seen that the electron beam passes in the vicinity of each inner shape.

  Usually, the three electron beams in an in-line arrangement emitted from the electron gun 8 are deflected at an aspect ratio of the phosphor screen 2 of M: N (for example, 16: 9 or 4: 3), and at the same time, the deflection yoke 9 The deflection trajectory of the electron beam when is convergence-free draws a trajectory in which the angle θ from the horizontal axis 2a has a maximum value near the deflection center position, that is, the reference line position, as indicated by the dotted line 30. More specifically, among the lines connecting the tube axis and the electron beam position, the slope of the line 76 connecting the tube axis and the point 74 near the line 71 is the maximum.

  The inner surface shape of the cone part 4 is set in consideration of the substantial trajectory path of the electron beam emitted from the electron gun 8, and the inner surface shape near the diagonal of the cone part 4 has a beam neck shadow with respect to the trajectory of the electron beam. It is necessary to secure a margin that does not occur and to prevent halation, which is a more severe condition than the beam neck shadow. In other words, the beam neck shadow is inevitably avoided if the inner surface shape is designed to prevent halation. The beam neck shadow and the halation are as described above with reference to FIGS.

  FIG. 6 shows a shape in which the inner surfaces 42 and 48 are aligned with the substantial trajectory of the electron beam to prevent halation in the vicinity of the continuous portion 20 of the cone portion 4. The inner surfaces 41 and 47 show inner surface shapes in which no beam neck shadow occurs. The diagonal axis D1 is a line connecting a point on the tube axis and a point on the inner surface 41 where the distance from the point on the tube axis is maximum. The angle formed by the diagonal axis D1 and the horizontal axis 2a is θ1.

  The diagonal axis D2 is a line connecting a point on the tube axis and a point on the inner surface 42 where the distance from the point on the tube axis is maximum. The angle formed by the diagonal axis D2 and the horizontal axis 2a is θ2. The distance L2 between the tube axis on the diagonal axis D2 and the inner surface 42 is longer than the distance L1 between the tube axis on the diagonal axis D1 and the inner surface 41. Further, the angle θ2 is smaller than the angle θ1.

  Further, Th is the thickness on the horizontal axis 2a of the tube wall, and Tv is the thickness on the vertical axis 2b. In the illustration of FIG. 6, Tv indicates the thickness when the inner wall has an inner surface shape 48 as will be described in detail later.

  In the cathode ray tube, the vacuum pressure strength and the deflection power are important for setting the outer shape of the cone portion 4. That is, it is premised that the prevention of halation alone is not sufficient, and the standards regarding the vacuum pressure resistance and the deflection power are satisfied.

  The inner surface shape 42 of the cone part 4 shown in FIG. 6 is such that the distance on the diagonal axis is increased from L1 to L2 while maintaining the outer diameter dimension DB of the diagonal part. The minimum thickness Td in the vicinity is reduced. For this reason, it is disadvantageous for ensuring the vacuum pressure resistance. If the outer shape of the cone portion 4 is increased outward, the thickness Td can be increased. However, since the diameter of the deflection yoke 4 is increased, the efficiency of the deflection magnetic field action on the electron beam is reduced, and the deflection power is reduced. It will increase.

  In this case, the tensile stress σD (see FIG. 18) in the vicinity of the diagonal axis can be suppressed by forming the outer shape so as to increase the radius of curvature Rd centered on the point on the diagonal axis D2. In this configuration, the strength of the diagonal portion can be secured while maintaining the outer diameter DB of the diagonal portion.

  Further, by forming the curvature radius Rd to be large, the outer surface 45 becomes the outer surface 46, and the thickness of the wall extending in the vertical direction increases, so that the compressive stress σH (see FIG. 18) in the vertical axis 2b direction can be suppressed. it can. Similarly, the outer surface 43 becomes the outer surface 44, the thickness of the wall extending in the horizontal direction is increased, and the compressive stress σV (see FIG. 18) in the horizontal axis direction can be suppressed. That is, the strength is improved in each of the diagonal portion, the wall extending in the vertical direction, and the wall extending in the horizontal direction.

  However, as described above, the angle θ2 formed between the horizontal axis 2a and the diagonal axis D2 is smaller than the angle θ1 between the horizontal axis 2a and the diagonal axis D1, so that the horizontal axis 2a Since the dent amount in the direction is increased, the width W2 of the wall extending in the horizontal direction is larger in the vicinity of the diagonal portion than the width W1 of the wall extending in the vertical direction.

  For this reason, in the vicinity of the diagonal portion, W2 is relatively larger than Td and W1. That is, the value of the stress σV is relatively smaller than the stresses σH and σD, and the magnitude relation of the stress is generated. More specifically, the strength drop between the vicinity of the horizontal axis 2a of the wall extending in the vertical direction and the vicinity of the diagonal portion is the difference in strength between the vicinity of the vertical axis 2b of the wall extending in the horizontal direction and the vicinity of the diagonal portion. Become bigger. That is, a phenomenon occurs in which stress concentrates at a location where the strength drop at the diagonal portion is large, which causes a decrease in the strength of vacuum pressure resistance.

  Therefore, in order to prevent a decrease in the vacuum pressure resistance, the thickness Tv of the horizontal wall portion where the stress is relatively small is reduced, the stress applied to the wall extending in the horizontal direction is increased as a whole, and the diagonal axis We focused on alleviating the stress concentration phenomenon in the vicinity. This is to reverse the magnitude relationship between Tv and Th with respect to the conventional case where Tv> Th> Td in consideration of the deflection margin for preventing the beam neck shadow. In other words, the purpose of this attention is to realize a structure that prevents halation that is more restrictive in structure than the prevention of beam neck shadows and that does not impair the deflection power and the strength against vacuum pressure.

  FIG. 7 is a diagram showing the characteristics of the present invention made in consideration of the above points, and the tube axis in the vicinity of the continuous portion 20 of the cone portion 4 formed to satisfy Th> Tv> Td. It is a cross-sectional shape in the vertical direction. In the configuration of FIG. 7, the inner surface shape 47 is dared to be the inner surface shape 48 in the configuration of FIG. 6, and Tv is thinned, and the stress applied to the wall extending in the horizontal direction is increased as a whole. In order to confirm the effect of this configuration, various experiments were performed, which will be specifically described below.

  The experimental results shown in Table 1 below show that the evaluation objects are halation, deflection power, and atmospheric pressure strength (maximum vacuum stress) for an example that satisfies the relationship of Th> Tv> Td and a comparative example that does not satisfy this relationship. This is the experimental result. The values of the dimensions shown in Table 1 are measured values at a position of 20 mm on the screen side from the reference line 21.

The circles in Table 1 indicate that the standards are met, and the x marks indicate that the standards are not met. About 100% or less is suitable for the deflection power and the pressure resistance strength. An atmospheric pressure strength of 100% or less indicates that the maximum vacuum stress is a reference value or less. Further, Th, TV, Td, DA, θ, and Rd in Table 1 are as described with reference to FIGS. 6 and 7. Note that, in the TV set, the overscan of the image display usually has a screen image range. In contrast, the range of approximately 108% is the maximum range. In other words, as a condition that halation does not occur, the electron beam in the overscan range of 108% does not collide with the inner surface of the cone portion, or the collision range of the electron beam with the inner surface of the cone portion is the length in the tube axis direction along the inner surface of the cone. It is that it is 10 mm or less. If this condition is satisfied, it has been confirmed that there is no problem with the halation phenomenon of the cathode ray tube, and the evaluation of halation is based on whether this condition is satisfied.

  First, Group A (Comparative Example 1, Comparative Example 2, Example 1) having a screen size of 76 cm will be described. These are not shown in Table 1, but the beam neck shadow criteria are satisfied. In addition, since each sample has the same length of the diagonal axis from the tube axis to the outer surface (corresponding to the outer diameter DB in FIG. 6), all the conditions for the deflection power were satisfied. The same applies to groups B and C.

  In Comparative Example 1, halation occurred. The inner surface shape of Comparative Example 2 was set such that the distance DA was 50.2 mm, which was larger than 49.8 mm of Comparative Example 1. In addition, the angle θ was 34 degrees in Comparative Example 2, which was smaller than 34.5 degrees in Comparative Example 1. This is the same as the displacement of the inner surface 41 to the inner surface 42 in FIG.

  As a result, the occurrence of halation could be prevented. However, the pressure resistance strength that was satisfactory in Comparative Example 1 is no longer satisfactory. This is presumably because the thickness Td was 4.9 mm due to the increased distance DA, which was smaller than 5.3 mm in Comparative Example 1.

  In Example 1, the outer surface radius Rd was set to 16.7 mm while maintaining the distance DA, which was larger than 16.1 mm of Comparative Example 2. When the outer surface radius Rd is increased, both Th and Tv are increased. However, in Example 1, Tv is not increased intentionally, and the magnitude relationship between Th and Tv is reversed as compared with Comparative Example 1, and Th (7.8 mm)> Tv. The relationship was (6.5 mm). As a result, it was possible to satisfy the pressure resistance strength.

  Next, Group B (Comparative Example 3, Comparative Example 4, Example 2) is an 86 cm type whose screen size is larger than Group A. In Comparative Example 3, halation occurred. The inner surface shape of Comparative Example 4 was set such that the distance DA was 51.5 mm, which was larger than 51.2 mm of Comparative Example 3. In addition, the angle θ was 34 degrees in Comparative Example 4, which was smaller than 34.5 degrees in Comparative Example 3. As a result, as in Comparative Example 2, the occurrence of halation could be prevented, but the pressure resistance strength that was satisfied in Comparative Example 3 was not satisfied. This is probably because, as in Comparative Example 2, the thickness Td was 5.9 mm and was smaller than 6.2 mm in Comparative Example 3 by increasing the distance DA.

  In Example 2, while maintaining the distance DA, the outer surface radius Rd was 16.7 mm, which was larger than 16.1 mm of Comparative Example 4. As in Example 1, Tv was not increased, and the relationship between Th and Tv was reversed compared to Comparative Example 4 so that Th (8.1 mm)> Tv (6.7 mm). . As a result, it was possible to satisfy the pressure resistance strength.

  Next, Group C (Comparative Example 5, Comparative Example 6, Example 3) is a 66 cm type whose screen size is smaller than Group A. In Comparative Example 5, halation occurred. The inner surface shape of Comparative Example 6 was set to have a distance DA of 53 mm and larger than 52.5 mm of Comparative Example 5. In addition, the angle θ was set to 32 degrees in Comparative Example 6 and smaller than 34.5 degrees in Comparative Example 5. As a result, as in Comparative Examples 2 and 4, the occurrence of halation could be prevented, but the pressure resistance strength that was satisfied in Comparative Example 5 was not satisfied. This is probably because, as in Comparative Examples 2 and 4, the distance DA was increased to 4.7 mm as a result of increasing the distance DA, which was smaller than 5.2 mm in Comparative Example 5.

  In Example 3, while maintaining the distance DA, the outer surface radius Rd was 16.7 mm, which was larger than 16 mm of Comparative Example 6. As in Examples 1 and 2, Tv is not increased, but compared to Comparative Example 6, the relationship between Th and Tv is reversed so that a relationship of Th (7.1 m)> Tv (6.3 mm) is obtained. I made it. As a result, it was possible to satisfy the pressure resistance strength.

  From the experimental results shown in Table 1, the configuration that satisfies the relationship of Th> Tv> Td, regardless of the screen size, prevents halation without increasing the outer tube diameter (without increasing the deflection power). However, it can be seen that the structure is effective for satisfying the pressure resistance strength.

  Further, an experiment was further conducted in order to examine the relationship between Th and Tv and the pressure resistance strength in more detail. Table 2 below shows the relationship between Th / Tv and the maximum vacuum stress. The values of Th and Tv shown in Table 2 are measured values at a position of 20 mm on the screen side from the reference line 21, similarly to the values in Table 1.

  All the samples in Table 2 have a screen size of 76 cm, and the diagonal distance DA (50.2 mm) of the inner surface and the outer surface radius Rd (16.7 mm) are unified.

  FIG. 8 shows the experimental results in Table 2. In FIG. 8, the values of Examples 1-3 and Comparative Example 2 in Table 1 are also plotted. As can be seen from the graph of FIG. 8, as the Th / Tv increases from a value lower than 1, the pressure resistance strength decreases and is almost the minimum in Examples 1 and 2 (Th / Tv = 1.20-1.21). Indicates the value. After that, it started to rise, and in the sample 4 (Th / Tv = 1.35), the pressure resistance strength exceeded 100%. This is considered that when Tv becomes too small compared to Th, the strength of the wall in the horizontal direction is excessively lowered, and the pressure resistance strength does not satisfy the standard.

  FIG. 9 is a graph obtained by re-plotting the sample plotted in FIG. 8 by replacing the value of Th / Tv with the maximum value of Th / TV in the entire region of the cone portion of each sample. According to FIG. 9, it can be seen that when the maximum value of Th / Tv is in the range of 1.11 to 1.39, the pressure resistance strength can be suppressed to within 100%.

  From the experimental results of Table 2, if Tv becomes relatively small compared to Th, the pressure resistance strength decreases, so this point requires design attention. However, this does not result from the relationship of Th> Tv itself, and even when the relationship of Th <Tv is satisfied, the same is true when Th is too small compared to Tv.

  FIG. 10 is a diagram showing the relationship between the position of the cone portion in the tube axis direction and the cross-sectional thickness (Th, Tv, Td) in Example 1 of Table 1. The origin position is the reference line position, the positive direction is the screen side, and the negative direction is the neck side. The same applies to FIGS. 11, 12, 13, and 15 below.

  The values of Th, TV, and Td shown in Table 1 are values at a position of 20 mm on the screen side from the reference line 21, but FIG. 10 is a plot of the cross-sectional thickness in the entire area of the cone portion. As can be seen from FIG. 10, the relationship of Th> Tv> Td becomes clearer as it approaches the screen side, and is particularly prominent in the range on the phosphor screen side with respect to the reference line.

  On the other hand, FIG. 11 is a diagram showing the relationship between the position of the cone portion in the tube axis direction and the cross-sectional thickness (Th, Tv, Td) in Comparative Example 1 of Table 1. In the comparative example 1, it turns out that it is the relationship of Tv> = Th> Td over the whole cone part.

  FIG. 12 is a diagram showing the relationship between the position of the cone portion in the tube axis direction and Th / Tv in Example 1 of Table 1. As can be seen from FIG. 12, the relationship is Th / Tv> 1 except in the vicinity of the continuous position with the neck portion. Further, there is a local maximum value P1 of Th / Tv at a position away from the reference line by 10 mm on the screen side.

  Here, as shown in FIG. 5 described above, the angle formed with the horizontal axis 2 a of the deflection trajectory of the electron beam has a maximum value as indicated by a line 76. Further, in the vicinity of the screen side of the line 71 indicating the reference line position, there is a part that maintains a value close to the maximum value, that is, a part that substantially maintains the inclination of the line 76. That is, in order to prevent halation in this portion, it is necessary to increase the degree of the concave shape as shown by the inner surface shape 42 in FIG. Therefore, as shown in FIG. 12, there is a maximum value of Th / Tv in the vicinity of the screen side of the reference line, and the value of Th / Tv is set to be higher than other parts so as to enhance the effect of reducing the maximum vacuum stress. It is getting bigger.

  That is, it can be said that increasing the value of Th / Tv is more effective on the screen side than the reference line, and more effective in the vicinity of the reference line. Example 1-3 shown in Table 1 sets the value of Th / Tv based on this. Specifically, as shown in FIG. 12, on the screen side from the reference line position (0 mm), the relationship of Th / Tv ≧ 1.1 is satisfied, particularly from the reference line position (0 mm) to 20 mm. Within the range, the value of Th / Tv is increased.

  FIG. 12 is an example of Example 1, but in all of Examples 1-3, from the reference line position, the reference line position and the end of the cone portion on the screen side (position of 35 mm in Example 1) are shown. The relationship of Th / Tv ≧ 1.1 is satisfied within a range up to 85% of the distance between them (about 30 mm in Example 1).

  The relationship between Th on the horizontal axis 2a and Tv on the vertical axis 2b has been described above. The thicknesses of the horizontal axis 2a and the vertical axis 2b in the vicinity of each axis are similar to Th and Tv. Of course, you may be satisfied. Specifically, in a cross-sectional shape satisfying Th> Tv, the substantial thickness in the horizontal axis 2a direction in the region sandwiching the horizontal axis 2a is Th ′, and the substantial thickness in the vertical axis 2b direction in the region sandwiching the vertical axis 2b is. If the thickness is Tv ′ and the lengths of the respective regions are the same, there may be a region range that satisfies Th ′> Tv ′. According to this configuration, molding is easy and the stress distribution becomes smooth.

  Table 3 below shows the values of Th ′ and Tv ′ on the axis obtained by translating the horizontal axis 2a and the vertical axis 2b in Example 1. The values in Table 3 are measured values at a position of 20 mm on the screen side from the reference line 21.

  The position (mm) in the left column of Table 3 indicates the distance from the horizontal axis 2a or the vertical axis 2b. In the right column, Th ′ (min) indicates the minimum value of Th ′ in the range up to each position, and Tv ′ (max) indicates the maximum value of Tv ′ in the range up to each position.

  Therefore, Th ′ (min) / Tv ′ (max) indicates the minimum value of Th ′ / Tv ′ in the range up to each position. For example, as long as the distance from the axis in Table 3 is within a range of up to 17 mm, Th ′ / Tv ′ is 1 or more regardless of which position is measured.

  Table 4 below shows the values of Th ′ and Tv ′ on the axis obtained by translating the horizontal axis 2a and the vertical axis 2b in Example 3. The values in Table 4 are measured values at the reference line position. The description of each value in Table 4 is the same as in Table 3 above.

  According to the example in Table 3, if the value of Th ′ / Tv ′ on the axis, that is, the value of Th / Tv is 1.2 or more, if it is within a range smaller than 17 mm from the axis, Th ′> Tv ′ It can be said that this relationship can be satisfied. According to the example of Table 4, when the value of Th ′ / Tv ′ on the axis, that is, the value of Th / Tv is larger than 1.1, if it is within 10 mm from the axis, Th ′ It can be seen that the relationship> Tv ′ can be satisfied.

  FIG. 13 is a diagram illustrating the relationship between the position of the cone portion in the tube axis direction and Th / Tv in Comparative Example 1 of Table 1. As described with reference to FIG. 11, since Comparative Example 1 has a relationship of Tv ≧ Th, Th / Tv is a value of 1 or less. This is particularly clear in the range from the reference line to the screen side edge. This is in contrast to the increase in Th / Tv in the range from the reference line to the screen side end in FIG.

  FIG. 14 is a cross-sectional view in a direction perpendicular to the tube axis of the cone portion according to the embodiment of the present invention. rdh is a point farthest from the tube axis in the horizontal direction among points on the inner surface in the vertical direction, and in the example of FIG. 14, the horizontal distance between the tube axis and rdh is H1. rdv is the point farthest from the tube axis in the vertical direction among the points on the inner surface in the horizontal direction, and in the example of FIG. 14, the vertical distance between the tube axis and rdv is V1.

  ΔH represents the maximum horizontal height on the inner surface in the vertical direction from the vertical line passing through rdh, and ΔV represents the maximum vertical height on the inner surface in the horizontal direction from the horizontal line passing through rdv. That is, ΔV represents the maximum height of the convex shape on the inner surface in the horizontal direction, and ΔH represents the maximum height of the convex shape on the inner surface in the vertical direction.

  As described with reference to FIG. 6, in the present embodiment, the inner shape of the cone portion reverses the conventional relationship of Th <Tv, and Th> Tv. For this reason, the pincushion shape on the inner surface in the vertical direction is made larger than the pincushion shape (convex shape) on the inner surface in the horizontal direction.

  FIG. 15 shows the relationship between the position of the cone portion on the tube axis in Example 1 of Table 1 and ΔH−ΔV. In the entire region on the tube axis, the relationship ΔH> ΔV is established in all regions, and ΔH−ΔV> 1.

  P2 in FIG. 15 is a value of ΔH−ΔV in the vicinity of an intermediate position between the reference line position and the front end position of the deflection yoke. In Example 1, the position of P2 is a position away from the reference line position by 20 mm. The value of ΔH−ΔV increases rapidly from the position of P2 toward the screen side.

  Here, as shown in FIG. 5, in the electron beam trajectory, the angle θ from the horizontal axis 2a has a maximum value in the vicinity of the reference line position. Thereafter, the angle θ decreases as the screen approaches from the middle of the cone, and the electron beam trajectory shifts toward the horizontal axis 2a.

  Accordingly, if the shape of the diagonal portion from the middle of the cone portion to the end portion on the panel portion side is a shape that is deeply cut closer to the horizontal axis, it is possible to prevent the electron beam from hitting the inner wall of the diagonal portion. .

  As described above, this is why ΔH> ΔV and the value of ΔH−ΔV is rapidly increased from the position P2 toward the screen side. For example, in FIG. 14, even if the thickness of the cone portion on the horizontal axis is kept, if the position of rdh is moved to the horizontal direction so that the distance H1 becomes longer, the shape of the diagonal portion is It will be cut closer to the horizontal axis. In this case, ΔH increases and the value of ΔH−ΔV also increases.

  Moreover, since the cross-sectional shape of the cone portion is substantially rectangular, the electron beam tends to approach the inner wall near the short axis (vertical axis). For this reason, it is possible to prevent the electron beam from hitting by setting the relationship of ΔH> ΔV and bringing the inner wall shape near the short axis close to a flat shape.

  As described above, the relationship of ΔH> ΔV can prevent the electron beam from hitting the inner wall of the diagonal portion, and can also prevent the electron beam from hitting the inner wall near the short axis. It becomes advantageous for prevention, and it becomes more advantageous if the value of ΔH−ΔV is increased.

  In the above embodiment, Th is described as the thickness of the tube wall on the horizontal axis 2a, and Tv is described as the thickness of the tube wall on the vertical axis 2b. It means the substantial thickness that determines the overall shape. Specifically, in the cross-sectional shape satisfying Th> Tv as shown in FIG. 7, if the thickness only in the vicinity of the horizontal axis is partially reduced, the overall shape of the tube wall is maintained while Th ≦ Tv. Will be obtained.

  However, in the present invention, Th> Tv, as described above, forms a shape in which the stress applied to the wall extending in the horizontal direction is increased as a whole and the stress concentration phenomenon near the diagonal axis is relaxed. Because.

  That is, Th and Tv serve as a reference for determining the overall shape of the tube wall. Therefore, as described above, in the shape in which the thickness only in the vicinity of the horizontal axis is partially reduced, the thickness Th of the shape in which the recess is filled so that the shape in the vicinity of the horizontal axis naturally changes is substantially obtained. It may be thick.

  This also applies to Th ′ near the horizontal axis 2a and Tv ′ near the vertical axis 2b.

  According to the cathode ray tube of the present invention, it is possible to effectively reduce the deflection power while preventing halation, and to sufficiently secure the pressure resistance strength of the vacuum envelope. Therefore, the present invention can be applied to, for example, a television receiver and a computer display. It is useful for cathode ray tubes used in

Sectional drawing of the cathode ray tube of this invention. The top view of the panel of the cathode ray tube shown in FIG. Sectional drawing of a pipe-axis perpendicular direction in the neck side end of the cone part which concerns on one embodiment of this invention. Sectional drawing of the pipe-axis perpendicular direction in the vicinity of the reference line of the cone part which concerns on one embodiment of this invention. Sectional drawing of the pipe-axis perpendicular direction in the screen side end of the cone part which concerns on one embodiment of this invention. The figure which shows the process which leads to the inner surface shape of the cone part which concerns on one embodiment of this invention. The figure explaining an example of the electron beam orbital path of a cone part. FIG. 3 is a cross-sectional view in the direction perpendicular to the tube axis of the cathode ray tube showing the process leading to the cone portion according to the embodiment of the present invention. FIG. 3 is a cross-sectional view in the direction perpendicular to the tube axis of the cone portion of the cathode ray tube according to one embodiment of the present invention. The figure which shows the relationship between Th / Tv and the maximum vacuum stress of the cathode ray tube which concerns on one embodiment of this invention. The figure which shows the relationship between Th / Tv and the maximum vacuum stress of the cathode ray tube which concerns on a comparative example The figure which shows the relationship between the position of the cone part of each cathode ray tube which concerns on one embodiment of this invention, and each part cross-sectional thickness. The figure which shows the relationship between the position of the cone part of the cathode ray tube which concerns on a comparative example, and each part cross-sectional thickness. The figure which shows the relationship between the position of the cone part which concerns on one embodiment of this invention, and Th / Tv. The figure which shows the relationship between the position of the cone part which concerns on a comparative example, and Th / Tv. FIG. 3 is a cross-sectional view in the direction perpendicular to the tube axis of the cone portion of the cathode ray tube according to one embodiment of the present invention. The figure which shows the relationship between the position of the cone part of the cathode ray tube which concerns on one embodiment of this invention, and (DELTA) H- (DELTA) V> 1. The perspective view of an example of the conventional cathode ray tube. The perspective view which shows the internal structure of an example of the conventional cathode ray tube. The figure which shows the mode of the effect | action of the stress of the cone part in the conventional cathode ray tube. Sectional drawing of the tube axis | shaft perpendicular direction of the cone part which concerns on an example of the conventional cathode ray tube. The schematic block diagram of an example of the conventional cathode ray tube. The top view of the panel of the cathode ray tube shown to FIG. 18A. The figure explaining the halation which concerns on an example of the conventional cathode ray tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum envelope 2 Panel 3 Funnel 4 Cone part 5 Neck part 6 Phosphor screen 7 Shadow mask 8 Electron gun 9 Deflection yoke 21 Reference line position

Claims (8)

A vacuum envelope including a panel portion including an electron gun and a phosphor screen formed on an inner surface thereof; a deflection yoke disposed on an outer periphery of the vacuum envelope and deflecting an electron beam emitted from the electron gun; A cathode ray tube comprising:
The vacuum envelope has a cross-sectional shape in a direction perpendicular to the tube axis of the cathode-ray tube corresponding to a position where the neck portion in which the electron gun is housed and the deflection yoke are disposed, and substantially in the entire tube axis direction. Including a non-circular cone portion,
The panel portion is formed substantially symmetrically with respect to a major axis and a minor axis orthogonal to each other,
Of the cross-sectional shape of the cone portion in the direction perpendicular to the tube axis, the substantial thickness on the major axis is Th, the substantial thickness on the minor axis is Tv, and the minimum thickness at the diagonal position. When the the Td, the cross-sectional shape from a reference line position serving as a reference for the deflection angle at each position on the tube axis in the range of up to an end portion of the panel portion side of the cone portion,
Th>Tv> Td
A cathode ray tube satisfying the following relational expression and having a maximum value of Th / Tv within the above range . The cathode ray tube according to claim 1 , wherein the maximum value is 1.11 or more and 1.39 or less. Th / Tv ≧ 1.1 is satisfied within the range from the reference line position serving as a reference for the deflection angle to 85% of the distance between the reference line position and the end of the cone portion on the panel side. The cathode ray tube according to claim 1 or 2. In the cross-sectional shape satisfying the relational expression, the substantial thickness in the major axis direction on the axis obtained by translating the major axis by the distance L is Th ′, and the minor axis is the same distance as the distance L. The cross-sectional shape satisfying Th ′> Tv ′ at any distance L when the substantial thickness in the minor axis direction on the translated axis is Tv ′ and the distance L is increased from 0 2. The cathode ray tube according to claim 1, wherein there is a range of the following area.   5. The cathode ray tube according to claim 4, wherein Th / Tv ≧ 1.2 is satisfied, and the range of the region is a range smaller than 17 mm from each axis.   5. The cathode ray tube according to claim 4, wherein Th / Tv> 1.1 is satisfied, and the range of the region is within 10 mm from each axis. In the cross-sectional shape of the cone portion in the direction perpendicular to the tube axis, of the points on the inner surface in the vertical direction of the cone portion, the point furthest from the tube axis in the horizontal direction is rdh, and the horizontal direction of the cone portion is Of the points on the inner surface, the point farthest from the tube axis in the vertical direction is rdv, the horizontal maximum height on the inner surface in the vertical direction from the vertical line passing through rdh is ΔH, and the horizontal from the horizontal line passing through rdv If the vertical maximum height on the inner surface of the direction is ΔV,
2. The cathode ray according to claim 1, wherein the cross-sectional shape at each position on the tube axis in a range from the reference line position to an end portion on the panel portion side of the cone portion satisfies a relationship of ΔH> ΔV. tube. In a range from a substantially intermediate position in a range from the reference line position to an end portion on the panel portion side of the cone portion to an end portion on the panel portion side of the cone portion, a value of ΔH−ΔV is the panel portion side. The cathode ray tube according to claim 7 , which increases as it approaches.

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