JP2006040811A - Glass funnel for cathode-ray tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass funnel for a cathode-ray tube in which the bevel side of a sealing end face, especially periphery, can be easily stained neither with damage nor dirt, and a glass funnel for the cathode-ray tube which can form a frit glass of suitable shape. <P>SOLUTION: The bevel side 10 along with the periphery of the sealing end face 2 of the funnel 1 is formed in a specific rough surface in which the surface ten-point average of roughness Rz and the average interval Sm of a surface unevenness fulfill the relation of 0.014≤[Rz/Sm]≤0.075. Desirably, the partial region or the entire region of the outside face 12 from the bevel side 10 along with the outer periphery of the sealing end face 2 to the maximum profile line 8 is set as the specific rough surface, and all the periphery of the outer peripheral side of the sealing end face 2 is set as the specific rough surface. Further, the partial region or the entire region of the bevel surface 11 along the inner periphery of the sealing end face 2 and the inside face 13 to the part corresponding to the maximum profile line 8 from this bevel surface 11 is set as the specific rough surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a glass funnel for a cathode ray tube, and more particularly to a technique for improving the surface condition around the sealing end face of the funnel.

  As is well known, a cathode ray tube used in a display device such as a color television receiver has, as main glass parts, a glass panel for a cathode ray tube (hereinafter, also simply referred to as a panel) on which an image is projected, and a substantially funnel-shaped glass for a cathode ray tube. A funnel (hereinafter, also simply referred to as a funnel). In this case, the panel has a substantially rectangular face portion having an effective screen for displaying an image, and four sides connected to the face portion via a blend R portion, and the skirt portion extends from these sides. In addition, a sealing end surface used for sealing with the funnel is formed at the opening end of the skirt portion.

  On the other hand, as shown in FIG. 5, the funnel 1 has a large opening end having a substantially rectangular sealing end surface 2 used for sealing with the panel at one end and the other end in the direction along the tube axis Z. 3 and a substantially circular small opening end 4 used for welding to the neck are formed, and the side wall portion 5 of the funnel 1 having the tube axis Z as a central axis line has a substantially funnel shape. More specifically, the side wall portion 5 of the funnel 1 has a body portion 6 extending from the large opening end 3 to a predetermined position on the small opening end 4 side, and a yoke portion 7 connected to the small opening end 4 side. The sealing end surface 2 at the large opening end 3 of the portion 6 is sealed and joined to the sealing end surface at the opening end of the panel via a frit glass.

  This funnel 1 supplies a molten glass block called gob into a receiving mold (female mold) composed of a bottom mold (bottom mold) and a side mold (shell mold) in a press molding process. And this is shape | molded by pressing with a pressing die (plunger metal mold | die). Therefore, a maximum outer shape line (mold match line) 8 that is a mold-matching line between the bottom mold and the shell mold is formed on the outer surface of the side wall 5 (body 6) of the funnel 1 and sealed. A wall portion extending from the end face 2 to the maximum outline 8 is a skirt portion 9 of the funnel 1. In addition, convex positioning reference portions 15a, 15b, and 15c are formed at predetermined positions on the outer surface of the side wall portion 5 of the funnel 1 in order to perform sealing with a panel and a neck with high accuracy.

By the way, according to the following Patent Document 1, the sealing end face 2 of the funnel 1 has an average size of 5 to 25 μm, an average depth of 10 to 25 μm, and an average number of 150,000 to 4 million pieces / cm ² . It is disclosed that a rough surface is formed of a large number of minute small-hole-shaped concave portions. According to this, the shape of the frit glass at the time of sealing the funnel 1 and the panel becomes good, and it can be expected to avoid a situation in which the cathode ray tube is destroyed in the manufacturing process.

  Further, according to the following Patent Document 2, the surface of the bottom mold for funnel molding is nitrided, and the surface roughness (Rz) is set to 15 to 35 μm. A structure that can be transferred from the mold to the body portion 6 of the funnel 1 is disclosed. According to this, improvement of glass releasability, press molding workability, and mold life can be expected.

  Further, according to the following Patent Document 3, a rough surface is formed on the upper surface portion adjacent to the sealing end surface 2 and the lower surface adjacent to the neck portion, of the inner surface of the side wall portion 5 of the funnel 1, and the surface roughness. It is disclosed that (Rz) is 15 to 40 μm. According to this, it can be expected that the friction between the mold and the glass is reduced, and the life of the plunger mold is extended (about twice).

Japanese Patent Publication No. 7-95431 Japanese Patent Laid-Open No. 9-255349 JP-A-4-294036

  By the way, the above Patent Documents 1 to 3 only disclose that the sealing end surface 2 of the funnel 1 is roughened and that the inner and outer surfaces of the side wall portion 5 of the funnel 1 are roughened. However, chamfering, that is, formation of a beveled surface, may be performed on the inner peripheral side or outer peripheral side of the sealing end surface 2 in this type of funnel 1. In spite of this, the fact is that the description of the properties of such a bevel surface is not made in any of the above patent documents 1 to 3 as well as other patent documents and non-patent documents.

  Therefore, as the properties of the above bevel surface, it is conceivable to make it a mirror surface or a substantially mirror surface close to the mirror surface, or on the contrary, a rough surface, but as a clear fact in the present situation, the removal of dirt In view of the importance of ease and the like, the bevel surface is usually a mirror surface or a substantially mirror surface. In other words, at present, no clear advantage has been found by making the beveled surface rough, and this is one of the causes, and the beveled surface is a mirror surface or a substantially mirror surface.

  Thus, when the bevel surface is a mirror surface or a substantially mirror surface, a large number of scratches are likely to be caused on the bevel surface on the outer peripheral side, particularly during various operations on the funnel after the formation of the bevel surface, during transportation, and handling. When such scratches are attached, there may be a case where a crack such as a crack is generated due to a strong tensile stress in the temperature lowering process at the time of sealing with the panel.

  Similarly, if a large number of scratches are made on the outer surface of the mirror surface or a substantially mirror surface when handling the funnel, the inside of the scratches will not be completely filled with the frit glass, and the frit glass will be on the bevel surface. There is a possibility that a portion that does not contact remains, and the adhesion strength between the bevel surface and the frit glass, and hence the sealing strength between the panel and the funnel, may be lowered.

  In addition, when the chamfered portion is a mirror surface or a substantially mirror surface as described above, the following problems are also caused. That is, in the sealing process between the panel and the funnel 1, in the initial stage, a panel with the sealing end face facing down is placed on the sealing end face 2 of the funnel 1 with the frit glass interposed. The frit glass is pressed by the sealing end face of the panel. As a result, the frit glass protrudes on both the inner and outer sides, and tends to flow along the inner and outer bevel surfaces of the sealing end surface 2 of the funnel 1.

  In this case, if the bevel surface is a mirror surface or a substantially mirror surface, since the flow resistance is small, the amount of frit glass flowing along the bevel surface increases, and until the frit glass becomes low temperature and solidifies. During this time, the frit glass is unreasonably hanging down. If the shape of the frit glass is inappropriate as described above, there is a problem that stress is concentrated on the inappropriate portion due to thermal deformation or the like at the time of temperature rise or temperature fall and breakage occurs.

  In addition, as described above, when a large number of scratches are formed on the outer peripheral side bevel surface, the flow state of the frit glass is different between the inner peripheral side and the outer peripheral side of the sealing end surface 2, As a result, the frit shape is different between the inner peripheral side and the outer peripheral side, and this also causes a problem of partial stress concentration and breakage due to this. In addition, since stress is generated twice on the outer peripheral side of the frit glass, if the frit shape on the outer peripheral side is inappropriate, the problem of breakage becomes significant.

  Although it is conceivable to make the beveled surface rough, it is not possible to solve the above-mentioned problem simply by simply making the beveled surface rough, and it has adhered to the beveled surface in the funnel manufacturing process. In order to attract new problems such as dirt becoming difficult to remove, the problem remains as to what measures are optimally taken.

  The present invention has been made in view of the above circumstances, and it is difficult for the bevel surface on the outer peripheral side of the sealing end surface to be scratched or stained, and it is possible to form a frit glass having an appropriate shape. Providing a funnel is a technical issue.

  The present invention made to solve the above technical problem comprises a large opening end having a substantially rectangular sealing end surface used for sealing with a glass panel for a cathode ray tube, and a substantially circular small opening end, In the glass funnel for a cathode ray tube having a substantially funnel shape, the ten-point average roughness Rz of the surface and the average interval Sm of the irregularities on the surface of the bevel surface along the outer periphery of the sealing end surface are 0.014 ≦ [Rz /Sm]≦0.075. The specific rough surface satisfies the relationship. In addition, the measurement of said Rz and Sm is based on JISB0601: 1982.

  According to such a configuration, the bevel surface formed on the outer peripheral side of the sealing end surface of the funnel is a specific rough surface that is not a mirror surface or a substantially mirror surface, and the specific rough surface is within the above numerical range. Therefore, the bevel surface on the outer peripheral side is less likely to be scratched, and the probability of occurrence of cracks during sealing heat treatment with the panel is reduced, and inappropriate dripping of the frit glass is suppressed. Residual adhesion hardly occurs.

  That is, if [Rz / Sm] <0.014, since the depth of the unevenness is relatively small in relation to the average interval of the unevenness, the surface is relatively close to the mirror surface. When handling the funnel, the bevel surface on the outer peripheral side is more likely to be scratched, and cracks may occur when the temperature is lowered during the sealing process with the panel. In addition, when the outer peripheral bevel surface is scratched in this way, the inside of the scratch is not completely filled with the frit glass, and the adhesion strength between the bevel surface and the frit glass, and thus the panel and the funnel are sealed. There is also a risk that the strength may decrease. Further, when the bevel surface is relatively close to the mirror surface, the flow resistance is reduced, and thus the frit glass is unduly drooping downward. Considering these matters, it is significant that [Rz / Sm] ≧ 0.014.

  On the other hand, if [Rz / Sm]> 0.075, since the depth of the unevenness is relatively large in relation to the average interval of the unevenness, the panel and the funnel are sealed. When the temperature rises during the process, the temperature distribution between the concave and convex portions varies. Due to this, the speed of the softening flow of the frit glass in contact with the bevel surface on the outer peripheral side is greatly different between the concave portion and the convex portion, so that the frit glass penetrates the bevel surface under uniform conditions. It becomes difficult to react and it becomes difficult to obtain a good frit shape. In addition, since the concave portion is relatively narrow, it is difficult to fill the frit glass into the concave portion due to the fact that the frit glass is in the form of a viscous slurry, and thus air remains in the concave portion. As a result, the adhesion strength between the bevel surface and the frit glass, and hence the welding strength, is reduced. Furthermore, if the recess is relatively narrow in this manner, dirt attached to the bevel surface in the funnel manufacturing process will be difficult to remove, and thus the glass bulb will be manufactured with the dirt remaining in the recess. Invite the situation. Considering these matters, it is significant to set [Rz / Sm] ≦ 0.075. The sealing end surface may be a mirror surface or a substantially mirror surface, but is preferably a specific rough surface similar to the above.

  In the above configuration, it is preferable that a part or all of the outer surface from the bevel surface along the outer periphery of the sealing end surface to the maximum outer shape line is a specific rough surface similar to the above.

  In this way, not only the outer peripheral bevel surface but also the outer surface extending from the outer peripheral bevel surface to the maximum outline (mold match line) can enjoy the same advantages as those already described. . That is, for example, when focusing on the frit shape, when the frit glass that has been appropriately prevented from flowing down by the outer bevel surface as described above further flows down the outer surface, its outer surface is 0. When .014 ≦ [Rz / Sm] ≦ 0.075, the frit glass can be prevented from flowing at an appropriate position and solidified more reliably. And, considering that it is optimal that the frit glass is solidified by preventing flow at a midway position from the bevel surface to the maximum outline, the significance of making this outer surface the above-mentioned specific rough surface is It will be extremely large. In addition, the area | region which makes this outer side surface said specific rough surface may be the whole area | region from a bevel surface of an outer peripheral side to the largest outline, and may be a partial area | region to the middle position. .

  Said structure WHEREIN: It is preferable to set it as said specific rough surface over the perimeter of the outer peripheral side of a sealing end surface.

  In other words, the bevel surface is preferably a specific rough surface over the entire circumference on the outer peripheral side of the sealing end surface, and the outer surface extending from the bevel surface to the maximum outer shape line also extends over the entire circumference. A specific rough surface is preferred. In this way, a uniform frit shape can be obtained over the entire circumference on the outer peripheral side of the sealing end face. In particular, if attention is paid to dealing with scratches at locations where stress concentration is likely to occur during the temperature lowering process during sealing with the panel, the center of each side and its periphery (for example, 50 mm or more and 150 mm or less from the major axis or minor axis) Or only the range on the outer peripheral side of the sealing end surface corresponding to the formation region of the positioning reference portion can be the specific rough surface. The bevel surface on the outer peripheral side itself is preferably formed over the entire circumference of the sealing end surface, but the center of each side and the periphery thereof (for example, a region of 50 mm or more and 150 mm or less from the major axis or minor axis) Alternatively, the bevel surface may be formed only in a range on the outer peripheral side of the sealing end surface corresponding to the formation region of the positioning reference portion.

  In the above configuration, the bevel surface along the inner periphery of the sealing end surface is preferably a specific rough surface similar to the above.

  If it does in this way, the advantage similar to the matter about the bevel surface of the outer periphery side mentioned above can be enjoyed also about the bevel surface of the inner periphery side of a sealing end face. Moreover, the frit shape can be the same or substantially the same on the inner peripheral side and the outer peripheral side, and can be made symmetrical with respect to the center in the thickness direction, so that a suitable frit shape can be obtained. In order to obtain such an advantage, both the inner peripheral bevel surface and the outer peripheral bevel surface have the same or substantially the same numerical value in the numerical range of the specific rough surface. A rough surface is preferred.

  In the above configuration, it is preferable that a part or all of the inner side surface extending from the bevel surface along the inner periphery of the sealing end surface to the portion corresponding to the maximum outline is the same specific rough surface as described above.

  In this way, not only the inner peripheral bevel surface but also the portion corresponding to the maximum outer contour line from the inner peripheral bevel surface (the same or substantially the same position as the tube axis direction where the largest outer contour line exists). The same advantages as those already described can be enjoyed with respect to the inner surface leading to (position). That is, as in the case described above, for example, if attention is paid to the frit shape, the frit glass that has been appropriately prevented from flowing down by the inner peripheral bevel surface as described above further flows down the outer surface. In this case, the frit glass can be prevented from flowing down at an appropriate position and solidified more reliably. In addition, the area | region which makes this inner side surface said specific rough surface may be the whole area | region from the inner peripheral side bevel surface to the site | part corresponding to the largest external shape line, and a partial area | region to the middle position It may be.

  Said structure WHEREIN: It is preferable to set it as said specific rough surface over the perimeter of the inner peripheral side of a sealing end surface.

  In other words, the bevel surface is preferably a specific rough surface over the entire circumference on the inner peripheral side of the sealing end surface, and the inner side surface extending from the bevel surface to the portion corresponding to the maximum outline is also A specific rough surface is preferred over the entire circumference. In this way, it is possible to obtain a uniform frit shape over the entire inner circumference side of the sealing end face, and particularly in locations where stress concentration is likely to occur during the cooling process during sealing with the panel. Focusing on the handling of scratches, the center of each side and its periphery (for example, an area of 50 mm or more and 150 mm or less from the major axis or minor axis), or the inner peripheral side of the sealing end face corresponding to the formation area of the positioning reference part It is also possible to make only the above-mentioned range into the specific rough surface. In addition, although it is preferable to form the bevel surface itself on the inner peripheral side over the entire circumference of the sealing end surface, the center of each side and its periphery (for example, 50 mm or more and 150 mm or less from the major axis or minor axis). The bevel surface may be formed only in the region on the inner peripheral side of the sealing end surface corresponding to the region) or the region where the positioning reference portion is formed.

  In the above configuration, the ten-point average roughness Rz of the specific rough surface preferably satisfies the relationship of 5 μm <Rz <15 μm.

  That is, if Rz ≦ 5 μm, the depth of the unevenness is absolutely too small. Therefore, when sealing the panel and the funnel with the frit glass interposed, the inner and outer bevel surfaces and the inner and outer side surfaces are transmitted. As a result, it becomes impossible to sufficiently suppress the frit glass from dripping more than necessary, and the frit glass droops inappropriately after solidification, making it difficult to obtain a good sealing shape. On the other hand, if Rz ≧ 15 μm, since the depth of the unevenness is absolutely too large, the temperature distribution between the recesses and the protrusions during the temperature rise in the sealing process between the panel and the funnel. As the softening flow speed of the frit glass differs greatly between the concave and convex portions, it is difficult to penetrate and react the frit glass on the inner and outer bevel surfaces and the inner and outer side surfaces under uniform conditions. In this case, it is difficult to obtain a good sealing shape. Therefore, in order to avoid these problems, it is advantageous that Rz is within the above numerical range.

  In this case, it is preferable that the average interval Sm of the surface irregularities on the specific rough surface is 100 to 400 μm. That is, if Sm <100 μm, the recess is too narrow, and therefore the frit glass is in a slurry form having viscosity, making it difficult to fill the recess with the frit glass. Adhesion strength and thus welding strength is reduced. Moreover, if the recesses are too narrow in this way, dirt and the like attached to the specific rough surface in the funnel manufacturing process will be difficult to remove, so that the glass bulb is manufactured with dirt remaining in the recesses. Invite. On the other hand, if Sm> 400 μm, since the concave portion is too wide, it becomes a smooth surface as a whole, and it becomes impossible to accurately suppress scratches, and when sealing the funnel and the panel. It is difficult to sufficiently suppress the frit glass from sagging along the specific rough surface, and it becomes difficult to obtain a good sealing shape. In addition, when the surface is smooth as a whole, the contact area between the specific rough surface and the frit glass is reduced, and the sealing strength may be reduced. Therefore, in order to avoid these problems, it is advantageous that Sm is within the above numerical range. Considering the above matters, the average interval Sm of the surface irregularities on the specific rough surface is more preferably 220 to 320 μm.

  As described above, according to the glass funnel for a cathode ray tube according to the present invention, the bevel surface formed on the outer peripheral side of the sealing end surface is a specific rough surface that is not a mirror surface or a substantially mirror surface, and the specific rough surface is Since the relationship of 0.014 ≦ [Rz / Sm] ≦ 0.075 is satisfied, the bevel surface on the outer peripheral side is less likely to be scratched, and the probability of occurrence of cracks during sealing heat treatment with the panel is reduced. In addition, an inappropriate sagging of the frit glass can be suppressed, and a suitable frit shape can be obtained, and furthermore, it is possible to prevent the occurrence of harmful effects due to residual adhesion of dirt and the like.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a glass funnel for a cathode ray tube according to an embodiment of the present invention. The basic components are the same as those of the conventional funnel shown in FIG. Constituent elements are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 1, the funnel 1 according to the embodiment of the present invention has a bevel surface 10 along the outer periphery of the sealing end surface 2 and a bevel surface 11 along the inner periphery. Both bevel surfaces 10 and 11 are formed over the entire circumference of the sealing end surface 2. In the entire area of both the bevel surfaces 10 and 11, the ten-point average roughness Rz of the surface and the average interval Sm of the surface irregularities satisfy the relationship of 0.014 ≦ [Rz / Sm] ≦ 0.075. Specific rough surface.

  Further, the entire outer surface 12 extending from the outer bevel surface 10 to the maximum outer shape line (mold match line) 8 and the entire inner surface 13 extending from the inner peripheral bevel surface 11 to the portion corresponding to the maximum outer shape line 8. Is a specific rough surface that satisfies the same relationship of 0.014 ≦ [Rz / Sm] ≦ 0.075 as described above. In this embodiment, the entire sealing end surface 2 is also a specific rough surface that satisfies the same relationship of 0.014 ≦ [Rz / Sm] ≦ 0.075 as described above.

  Further, the ten-point average roughness Rz of the specific rough surface is set to 5 μm <Rz <15 μm. Further, the average interval Sm between the surface irregularities on the specific rough surface is set to 100 to 400 μm (preferably 220 to 320 μm).

  The bevel surface 10 on the outer peripheral side of the funnel 1 having the specific rough surface as described above and the outer side surface 12 (including the sealing end surface 2 in this embodiment) are equivalent to the molding surface of the shell mold as described above. And the molding surface of the shell mold is transferred to the funnel 1 by press molding. Similarly, the bevel surface 11 on the inner peripheral side of the funnel 1 and the inner side surface 13 connected to the inner surface 13 of the funnel 1 having the specific rough surface as described above specify the corresponding portion of the molding surface of the plunger mold as described above. A rough surface is formed, and the molding surface of the plunger mold is transferred to the funnel 1 by press molding. The specific rough surface of the funnel 1 is an unpolished surface. The molding method is not limited to this, and the specific rough surface may be formed on the funnel 1 by polishing.

  In this case, when the specific rough surface of the funnel 1 is [Rz / Sm] <0.014, for example, Rz ≦ 5 μm, as shown in FIG. The frit glass 14 is easy to flow at the time of sealing 20 and the funnel 1, the angle of the contact end portion of the frit glass 14 with respect to the outer side surface 12 and the inner side surface 13 of the funnel 1 is reduced, or the maximum outline 8 of the funnel 1. There is a high possibility that the frit glass 14 is accumulated around the periphery of the glass tube, and stress concentrates when the temperature of the cathode ray tube is lowered, leading to destruction of the cathode ray tube.

  On the contrary, when [Rz / Sm]> 0.075, for example, when Rz ≧ 15 μm, as an example, the sealing between the panel 20 and the funnel 1 is performed as shown in FIG. Since the flow of the frit glass 14 is unduly hindered during wearing and the angle of the contact end portion of the frit glass 14 with respect to the outer side surface 12 and the inner side surface 13 of the funnel 1 becomes excessively large. Increased chance of destruction.

  On the other hand, when the specific rough surface is 0.014 ≦ [Rz / Sm] ≦ 0.075, the frit glass 14 is sealed when the panel 20 and the funnel 1 are sealed as shown in FIG. Is not excessively flown and the flow is not unduly hindered, and the cross-sectional shape is close to a partial circle. Therefore, the angle of the contact end of the frit glass 14 with respect to the outer surface 12 and the inner surface 13 of the funnel 1 Is less likely to cause destruction of the cathode ray tube when the temperature is lowered.

  As Examples 1 to 5 of the present invention, Rz / Sm of the bevel surface 10 on the outer peripheral side and the outer surface 12 extending from the bevel surface 10 to the maximum outline 8 is set to 0.014, 0.019, 0.040, 0. Funnel 1 with 0.065 and 0.075 was prepared, and funnel 1 with Rz / Sm of 0.010 and 0.080 was prepared as a comparative example. The Rz / Sm of the bevel surface 11 on the inner peripheral side of the funnel 1 and the inner side surface 13 extending from the bevel surface 11 to the portion corresponding to the maximum outline 8 and the sealing end surface 2 are all 0.060. . The frit shape when the funnel 1 and the panel 20 are sealed with the frit glass 14 interposed therebetween is measured by visualizing the frit shape divided into an outer surface side and an inner surface side, and the cathode ray tube is damaged when the temperature is lowered. Inspected whether or not. The results are shown in Table 1 below. In Table 1 below, “OO” means that it is very good, “O” means that it is good, and “X” means that it is bad.

  According to Table 1 above, in Examples 1 to 5, Rz / Sm of all the outer peripheral side and inner peripheral side and the sealing end face are within the numerical range of the specific rough surface. It was confirmed that the frit shape on the side was all good, and that the cathode ray tube was not damaged at the time of temperature drop due to the frit glass. On the other hand, in Comparative Example 1, since the outer peripheral side is smaller than the numerical value range of Rz / Sm on the specific rough surface, the frit shape on the outer surface side is poor, and the temperature at the time of temperature decrease caused by the frit glass is low. The cathode ray tube was damaged, and in Comparative Example 2, since the outer peripheral side was larger than the numerical value range of Rz / Sm on the specific rough surface, the frit shape on the outer surface side was defective and the frit glass was caused. The cathode ray tube was damaged when the temperature was lowered.

  Next, as Examples 6 to 10 of the present invention, Rz / Sm of the outer peripheral side bevel surface 10 and the outer surface 12 extending from the bevel surface 10 to the maximum outline 8, the inner peripheral bevel surface 11 and the bevel The inner surface 13 extending from the surface 11 to the portion corresponding to the maximum outline 8 and the Rz / Sm of the sealing end surface 2 are all 0.014, 0.019, 0.040, 0.065, and 0.075. The funnel 1 having the same Rz / Sm of 0.010 and 0.080 was prepared as a comparative example. The frit shape when the funnel 1 and the panel 20 are sealed with the frit glass 14 interposed therebetween is measured by visualizing the frit shape divided into an outer surface side and an inner surface side, and the cathode ray tube is damaged when the temperature is lowered. Inspected whether or not. The results are shown in Table 2 below. In Table 2 below, “OO”, “O”, and “X” mean the same items as described above.

  According to Table 2 above, in Examples 6 to 10, since the Rz / Sm of all the outer peripheral side and inner peripheral side and the sealing end surface are within the numerical range of the specific rough surface, the outer surface side and the inner surface It was confirmed that the frit shape on the side was all good, and that the cathode ray tube was not damaged at the time of temperature drop due to the frit glass. On the other hand, in Comparative Example 3, since the Rz / Sm of the outer peripheral side and the inner peripheral side and the sealing end surface is smaller than the numerical range of the specific rough surface, the frit shapes on both the outer surface side and the inner surface side are poor. In addition, the cathode ray tube is damaged when the temperature is lowered due to the frit glass. In Comparative Example 4, the Rz / Sm of the outer peripheral side, the inner peripheral side, and the sealing end surface is larger than the numerical range of the specific rough surface. Therefore, the frit shape on both the outer surface side and the inner surface side is poor, and the cathode ray tube is damaged when the temperature is lowered due to the frit glass.

  Furthermore, as Examples 11 to 17 of the present invention, after setting Rz / Sm of all outer peripheral sides and inner peripheral sides and sealing end faces to 0.020 to 0.060, these Rz were set to 3 μm, 5 μm, Funnels 1 having a size of 8 μm, 10 μm, 12 μm, 15 μm, and 17 μm were produced. The frit shape when the funnel 1 and the panel 20 are sealed with the frit glass 14 interposed therebetween is measured by visualizing the frit shape divided into an outer surface side and an inner surface side, and the cathode ray tube is damaged when the temperature is lowered. Inspected whether or not. The results are shown in Table 3 below. In Table 3 below, “OO” means the best condition, and “OO”, “O”, and “X” mean the same items as above.

  According to Table 3 above, in addition to obtaining good results for all of Examples 11 to 17, better results are obtained when Rz is 5 to 15 μm, and Rz is 8 to In the case of 12 micrometers, it came to confirm that the further favorable result was obtained.

It is a perspective view which shows the glass funnel for cathode ray tubes which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the glass bulb for cathode ray tubes which seals the glass funnel for cathode ray tubes and the glass panel for cathode ray tubes which concerns on embodiment of this invention through frit glass. It is a longitudinal cross-sectional view which shows the problem of the glass bulb for cathode ray tubes produced using the conventional glass funnel for cathode ray tubes. It is a longitudinal cross-sectional view which shows the problem of the glass bulb for cathode ray tubes produced using the conventional glass funnel for cathode ray tubes. It is a perspective view which shows the conventional glass funnel for cathode ray tubes.

Explanation of symbols

1 Funnel (glass funnel for cathode ray tube)
2 Sealing end face 3 Large opening end 4 Small opening end 5 Side wall 8 Maximum outline (mold match line)
9 Skirt portion 10 Inner peripheral bevel surface 11 Outer peripheral bevel surface 12 Outer side surface 13 Inner side surface 14 Frit glass 20 Panel (glass panel for cathode ray tube)

Claims (7)

In a glass funnel for a cathode ray tube having a large opening end having a substantially rectangular sealing end surface used for sealing with a glass panel for a cathode ray tube, and a substantially circular small opening end, and having a substantially funnel shape,
The bevel surface along the outer periphery of the sealing end surface is specified so that the ten-point average roughness Rz of the surface and the average interval Sm of the irregularities on the surface satisfy a relationship of 0.014 ≦ [Rz / Sm] ≦ 0.075. A glass funnel for a cathode ray tube characterized by having a rough surface.   2. The glass funnel for a cathode ray tube according to claim 1, wherein a part or all of an outer surface extending from a bevel surface along the outer periphery of the sealing end surface to a maximum outline is the specific rough surface.   The glass funnel for a cathode ray tube according to claim 1 or 2, wherein the specific rough surface is formed over the entire circumference on the outer peripheral side of the sealing end surface.   The glass funnel for a cathode ray tube according to any one of claims 1 to 3, wherein a bevel surface along the inner periphery of the sealing end surface is the specific rough surface.   5. The glass for a cathode ray tube according to claim 4, wherein a part or all of an inner side surface extending from a bevel surface along an inner circumference of the sealing end surface to a portion corresponding to a maximum outer shape line is the specific rough surface. Funnel.   6. The glass funnel for a cathode ray tube according to claim 4, wherein the specific rough surface is formed over the entire inner circumference side of the sealing end surface.   The glass funnel for a cathode ray tube according to any one of claims 1 to 6, wherein a ten-point average roughness Rz of the surface of the specific rough surface satisfies a relationship of 5 µm <Rz <15 µm.