JP3374909B2 - Glass panel for cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to a glass for a cathode ray tube.
Regarding panels, in particular, physical strengthening and thermal stress
Glass panels for cathode ray tubes with improved strength against
You. [0002] 2. Description of the Related Art In recent years, display images of televisions and monitor devices have been developed.
With the flattening of the surface, a compressive stress layer is formed on the surface to strengthen it
Glass panel for cathode ray tube
Is used. FIG. 3 shows a conventional glass panel for a cathode ray tube.
FIG. As shown in FIG.
The panel 1 is substantially perpendicular to the face 2 and its periphery.
The face portion 2 and the side wall portion 3
It has a structure consisting of a blend R part 4 connected by a curved surface.
To manufacture a cathode ray tube using the glass panel 1 for a cathode ray tube.
Caused by a vacuum inside
Maximum tensile stress at the periphery of the face portion 2, especially at the center of the long side.
It occurs in the area 2b on the outer surface. Therefore, glass for cathode ray tubes
Panel 1 has a ferrule to maintain the required compressive strength.
The compressive stress value of the base portion 2, especially in the peripheral region 2 b thereof, is maximum.
The compression stress layer is formed so that A glass for a cathode ray tube reinforced as described above
The panel 1 is made of a molten metal filled in a female mold and a side frame mold.
Press the molten glass with a male mold to remove the male mold.
Remove to expose the inner surface of the cathode ray tube glass panel 1
When the portion 3 is substantially solidified, the side frame contacting the side wall portion 3
The mold is removed to expose the side wall 3, and then the cathode ray tube
After removing the lath panel 1 from the mold, the glass for the cathode ray tube is removed.
Spanel 1 at a predetermined temperature above the annealing point of glass
From the inside to the outside surface of the glass panel 1 for a cathode ray tube.
Quenching to a temperature lower than the strain point of the glass
Manufactured. The glass for a cathode ray tube manufactured as described above.
In the panel 1, the diagonal axis end of the effective screen 2a
Near the seal edge portion 3a of the side wall portion 3 extending from the portion 2c
It is found that a tensile stress T is generated on the outer surface 3b of
Was. This tensile stress T produces the glass panel 1 for a cathode ray tube.
During production, the surface of the glass is rapidly cooled to form a compressive stress layer.
In the process, the thickness distribution of the glass panel 1 and the three-dimensional
Temperature distribution due to the complex structure,
It occurs based on the degree distribution. That is, the glass panel 1 for a cathode ray tube is cooled.
When the temperature falls below the strain point,
The temperature distribution at which the temperature of the metal part 2 is higher than that of the side wall part 3 is shown.
Then, the thin side wall 3 is located at a strain point before the face 2.
Drop to a lower temperature. Therefore, the pair of the effective screen section 2a
Seal edge of the side wall portion 3 extending from the angular end 2c
A tensile stress T is generated on the outer surface 3b near the portion 3a. Special
Glass with a strong compressive stress layer formed on the surface
In the case of reinforced panels, the difference in stress distributed to each part
3 (B) and 3 (C) as indicated by hollow arrows.
Thus, in the three-dimensional structure of the glass panel 1 for a cathode ray tube,
As a result, the stress and the
Near the end 2c of the effective screen portion 2a of the base portion 2 in the diagonal axis direction.
A stress acts in the direction in which the warpage deformation S occurs, and the stress
Direction where the corners are bent as shown by the dotted line
Is considered to cause a tensile stress T on the outer surface 3b.
available. [0007] SUMMARY OF THE INVENTION A compressive stress layer is formed on the surface.
The reinforced and strengthened glass panel 1 for a cathode ray tube described above
The side wall where tensile stress T is generated by handling etc.
If deep scratches enter the outer surface 3b at the corner of 3,
Cracks occur in the thickness direction starting from the scratches on the panel
Have a problem in that they will self-destruct. In addition, the outer surface 3b
Even if the scratches are slight, the glass
Heating work for frit sealing between flannel 1 and funnel
And the thermal stress in the exhaust process during cathode ray tube manufacturing
In the process, starting from a slight scratch on the outer surface 3b
Cracks extend in the thickness direction, and glass panel 1 for cathode ray tube
There is a problem in that it is destroyed. Furthermore, these things
Is a constraint when improving the breakdown voltage by the compressive stress layer
There is a problem in that. [0008] The present invention has the above-mentioned problems of the prior art.
To increase the pressure resistance and
Gas for cathode ray tube that can prevent destruction by force
It is intended to provide a lath panel. [0009] SUMMARY OF THE INVENTION A cathode ray tube according to the present invention is provided.
The glass panel has an effective screen on which the image is projected
A substantially rectangular face portion, and substantially perpendicular from the periphery of the face portion.
Seal edge extending in the vertical direction and sealed to other members
Side wall with
Glass panel for cathode ray tube with power layer formed
And extending from a diagonal axis end of the effective screen portion.
Tensile stress generated on the outer surface near the seal edge of the side wall
The value σ_T0In the area of the periphery of the face portion.
The maximum compressive stress value of the measured compressive stress layer is σ_CMTo be
Then σ_To≤ (1/2) σ_CMHave a relationship
It is characterized by. In order to increase the pressure resistance of the cathode ray tube, a surface
Maximum compressive stress value σ of the compressive stress layer of_{C M}Over the specified value
Conventional CRT glass panel, the maximum compressive stress
Value σ _CMTension generated on the outer surface 3b of the corner portion
Tensile stress value of stress σ_ToIs the maximum compressive stress value σ_CM1 /
2 and the tensile stress caused by this tensile stress
The flannel is destroyed. The glass panel for a cathode ray tube of the present invention
Is the tensile stress value σ_ToIs the maximum compressive stress value σ_CM1/2 of
The required maximum compressive stress value σ_{C M}With
When producing a cathode ray tube having the desired pressure resistance.
Therefore, the cathode ray caused by the tensile stress on the outer surface of the corner
Prevents breakage of the glass panel for tubes and the resistance of cathode ray tubes
Maximize pressure strength. The glass panel for a cathode ray tube according to the present invention comprises:
σ_To≤ (1/2) σ_CMAnd σ_To≦ 7MPa
Characteristic. The tensile stress value σ
_ToIs set to 7 MPa or less, so that the
Enhance the effect of preventing the destruction of the spanel Further, the glass panel for a cathode ray tube according to the present invention.
Is 14MPa ≦ σ_CMHave the relationship Maximum compression
Stress value σ_CMTo 14 MPa or more, the cathode
The tensile stress σ of the glass panel for a wire tube_ToLimited by
It is possible to increase the upper limit of the compressive stress value. (Function) The present invention relates to a sealing edge portion of a side wall portion.
Tensile stress value σ generated on the outer surface of the corner in the vicinity_ToRequired
Part maximum compressive stress value σ_CMCathode ray tube smaller for
Glass panel. Check the pressure resistance of the cathode ray tube
While holding the bell
Prevents destruction from the outer surface of the toner part. Destruction can be prevented
Required tensile stress value σ_To, The maximum compressive stress value σ
_CMFor cathode ray tube with higher pressure resistance
Construct a lath panel. [0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a glass tube for a cathode ray tube according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of an embodiment of a panel, in which 1 is a shadow.
A glass panel for an arc tube, 2 is a substantially rectangular face portion,
2a is an effective image area on which an image is projected, and 2b is an effective image area.
The area of the outer surface at the center of the long side of the periphery of the surface portion 2a, 2c is effective
Reference numeral 3 denotes a diagonal end of the screen portion 2 a in the diagonal axis direction.
The side wall portion extending from the edge and forming the side wall is a seal 3a.
3b is a seal edge at a corner of the side wall 3.
FIG. 4 shows the outer surface in the vicinity of the joint 3a.
The same reference numerals are given to the same parts as. A glass panel for a cathode ray tube according to the present embodiment.
Is a substantially rectangular shape provided with an effective screen portion 2a on which an image is projected.
Face portion 2 and a substantially perpendicular direction from the periphery of face portion 2
And a side wall portion 3 extending in the direction
To maintain the required compressive strength when a wire tube is manufactured
In particular, in the area 2b of the face portion 2, particularly in the peripheral edge thereof,
The face portion 2 and the side wall are so arranged that the compressive stress value is maximized.
A compressive stress layer is formed on at least the outer surface of
Further, the diagonal axial end 2c of the effective screen 2a
Outer surface of the side wall portion extending from the vicinity of the seal edge portion 3a
Tensile stress value σ generated on surface 3b_ToBut glass for cathode ray tube
Maximum compressive stress value of compressive stress layer formed on panel surface
σ_CMHas a stress relationship of 1/2 or less. Also other real
As the glass panel for a cathode ray tube according to the embodiment,
Force value σ_ToIs 7 MPa or less, and the compressive stress
The layer has the maximum compressive stress value σ_CMFormed above 14MPa
Have been. Further, the glass panel for a cathode ray tube of the present invention is
When manufacturing, molten glass is added to the female mold and side frame mold.
And press-molding using a male mold
Step 1 and removing the male mold and glass panel for cathode ray tube
When the inner surface of the side wall is exposed and the side wall portion 3 is substantially solidified,
Remove the side frame mold in contact with the side wall 3 to expose the side wall 3
The second step is to remove the glass panel for the cathode ray tube from the mold.
The glass panel 1 for a cathode ray tube is at or below the annealing point of the glass.
The face part 2 and the side wall part 3
To keep the temperature drop almost the same as
While managing, the inner and outer surfaces of the glass panel 1 for cathode ray tubes
Rapid cooling to a temperature lower than the glass strain point by applying cooling air
And a third process. In particular, in the third step, first,
Place a heater or the like near the seal edge 3a of the side wall 3.
Then, the temperature is kept at the temperature of the annealing point, and the thin side wall 3 is
Prevents the temperature from dropping below the strain point prior to ace 2
The temperature difference between the face portion 2 and the side wall portion 3
And then blow cooling air to
The base part 2 and the side wall part 3 are almost similarly heated from a temperature above the annealing point.
A step including a step of lowering the temperature to a temperature lower than the strain point.
Can be Further, in the third step, the heater
-Keeping the temperature at about the slow cooling point by blowing air, etc.
Quenching by adding
Can be In the third step, the thin side wall portion 3 is formed.
Before the face 2 cools down from the strain point
Heat insulation means such as a heater to prevent
The vicinity of the seal edge 3a of No. 3 is maintained at a temperature of about the annealing point.
For example, the sealing edge 3a of the side wall 3 is attached.
Approach the hot air or burner flames
It is possible to adopt a heat retaining method of heating the heat. Ma
In addition, the location of heat insulation by such heat insulation means is the side wall
The entire portion 3, the entire vicinity of the seal edge portion 3a of the side wall portion 3,
The side wall extending from a diagonal end of the effective screen portion
Only on the outer surface near the seal edge
Edge or the inner and outer surfaces near the seal edge
Target. A reinforced cathode having a compressive stress layer formed on the surface.
For the glass panel for cathode ray tube,
Maximum compressive stress value σ of the compressive stress layer formed on the surface_CMIncrease
When enlarged, it extends from the diagonal end of the effective screen section
Outer surface 3b near the seal edge 3a of the side wall 3
The tensile stress T generated at the time increases, especially the maximum compressive stress value σ
_CMIs larger than a predetermined value, the tensile stress value σ_Toof
The increase is even more pronounced. Manufactured by conventional manufacturing methods
Maximum compressive stress value σ of compressive stress layer_CMIs greater than a predetermined value
The glass panel for a cathode ray tube has a maximum compression of the compressive stress layer.
Stress value σ_CMThe tensile stress greater than 1/2 of
Occurs on the outer surface 3b near the edge 3a, and may cause
Mean time to failure significantly reduces thermal stress failure
Cheap. In other words, the cathode wire strengthened by the conventional compressive stress
The glass panel for a pipe has the tensile stress value σ_ToIs the compressive stress
Maximum compressive stress value of layer σ_CMIndicates a value greater than 1/2 of
And frit the glass panel for the cathode ray tube and the funnel
Breakage during the sealing process and the exhaust process during cathode ray tube manufacturing
Breaking frequency increases. On the other hand, the cathode ray tube gun of the present embodiment
The lath panel is located near the seal edge 3a of the side wall 3.
Since it is manufactured by controlling the temperature as described above, the face
The difference in the compressive stress value between the portion 2 and the side wall portion 3 is reduced so that the side wall portion
Stress in the direction in which 3 falls down and effectiveness of face 2
Warp deformation S occurs near the diagonal axis end 2c of the screen 2a.
Reduces tensile stress based on the stress in the turning direction, for cathode ray tubes
Regardless of the size and face shape of the glass panel,
Tensile stress value σ at the location_ToIs suppressed, the tension
Stress value σ_ToIs the maximum compressive stress value σ_CMLess than 1/2 of
The frit sheet when manufacturing a cathode ray tube.
In the exhaust process during cathode ray tube manufacturing
Is prevented. In order to prevent the fracture, the tensile stress value
σ_ToIs preferably 7 MPa or less.
In this case, the breakage due to the thermal stress in the above step is substantially avoided.
It is possible. Furthermore, the resistance of the glass panel for cathode ray tubes
To increase the pressure, the maximum compressive stress value σ_CMHigh enough
It is important to prevent damage due to thermal stress
Maximum compressive stress value σ_CMRange of 14MPa or more
It becomes possible. The tensile stress of the glass panel for a cathode ray tube
Value σ_ToThe following method was adopted as the measuring method of
That is, the same glass material as the glass panel 1 for a cathode ray tube is used in advance.
A large number of test specimens that have been strain-reduced in
Scratches 300μm deep and 10mm long with a glass cutter
The strain gauge on the surface on which the flaw was engraved.
Water under a bending load of 6 to 12 MPa.
It was immersed in water to measure the breaking time t, and as shown in FIG.
The relationship between the value of the tensile stress applied to the surface and the fracture time t
Ask for it. Next, the tension response of the glass panel 1 for a cathode ray tube is performed.
Force value σ_ToIndicates that a glass cup is
Cut a scratch of 300 μm depth and 10 mm length with a water
It was immersed in water and measured the destruction time t required for self-destruction.
By applying the fracture time t to the relationship shown, the tensile stress
Value σ_ToIs a measurement method for obtaining [0022] DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a shadow produced by the production method of the present invention will be described.
Examples 1 to 4 of a glass panel for an arc tube and Comparative Examples 1 and 2
Hereinafter, the present invention will be described with reference to FIGS. Table 1 shows the shade of the present invention.
Examples of cathode ray tube glass panels and cathode ray tubes for comparative examples
It shows various data of the glass panel. Embodiment of the glass panel for a cathode ray tube according to the present invention
The panel A, which is a sample of No. 1, is a diagonal dimension of the face 2.
Method is 21 inches and the aspect ratio is 4: 3.
Of the compressive stress layer at the peripheral edge 2b of the outer surface of the
Compressive stress value σ_CMIs 14.0 MPa on average and the sidewall
Outer surface 3 near seal edge 3a at corner of section 3
tensile stress value σ of tensile stress T generated in b_ToIs 6 on average.
7 MPa, tensile stress T and tensile stress value σ_ToAnd the ratio
Rate σ_To/ Σ_CMIs 0.479. The panel B of the second embodiment has a pair
The angular dimension is 28 inches and the aspect ratio is 16: 9
The time required for self-destruction was 2,719-10,665 minutes
And self-destruct after an average of 5,031 minutes. Pa
Tensile stress value σ of flannel B_ToIs 6.8 MPa on average
The ratio σ_To/ Σ_CMIs 0.483. The panel C of the third embodiment has a pair
Angular dimension is 32 inches and aspect ratio is 16: 9
The time required for self-destruction was 1,715 to 6,159 minutes
Yes, it ruptures after an average of 3,225 minutes. Panel
Tensile stress value σ_ToIs 6.9 MPa on average
The ratio σ_To/ Σ_CMIs 0.485. The panel D of Example 4 has a pair
Angular dimension is 32 inches and aspect ratio is 16: 9
It took 1,063 minutes to 1,711 minutes
And self-destruct after an average of 1,315 minutes. Pa
Tensile stress value σ of flannel C_ToIs 7.2 MPa on average
The ratio σ_To/ Σ_CMIs 0.493. Panel E of Comparative Example 1 was similar to Panel C.
It has the same dimensions and is taken out of the mold after molding
Of the sealing edge 3a of the side wall 3 of the panel to be compared with the embodiment.
All were produced by keeping the temperature for an extremely short time. 5 pieces
Tensile stress value σ of panel E_{T o}Was measured. Panel E
Breaking time is 121-552 minutes. Panel E tension
Stress value σ_ToIs an average of 7.6 MPa and the ratio σ_To
/ Σ_CMIs 0.517. Panel F of Comparative Example 2 has the same dimensions as panel C.
Panel that has been molded and removed from the mold.
The conventional method that does not keep the seal edge 3a of the side wall 3
It was produced by the process. Tensile of panel F
Stress value σ_ToWas measured. The destruction time of panel F is 12
~ 133 seconds, and all five of the panels
Has broken. Tensile stress value σ of panel F_ToIs 1 on average
1.0 MPa and the ratio σ_To/ Σ_CMIs 0.570
It is. The maximum compressive stress value σ shown in Table 1
_CMIs the region of the outer surface at the center of the long side of the periphery of the face portion 2
A sample piece is cut out from the portion containing 2b, and a photoelastic strain meter is used.
Senarmon specified in JIS-S2305 by using
Of the data measured by the
You. [0030] [Table 1]Next, the glass panel for a cathode ray tube according to the present invention.
The frit seal between the panel and the funnel.
Assessment by testing the possibility of destruction
Was. In the same manner as in Examples 1 to 4,
# 8 on the outer surface 3b near the seal edge 3a
0 Scratch with sandpaper to scratch about 70μm deep
Samples of 10 panels A ', B', C ', D'
Produced. As Comparative Examples 1 'and 2', the comparative examples
Prepare 10 panels each similar to panels 1 and 2, and
Prepare samples of panel E 'and panel F' by injury
did. The panels A ', B' of Examples 1 'to 4',
C ', D', panels E ', F' of Comparative Examples 1 ', 2'
When placing each sample in a heating furnace and frit sealing
Heat up to 440 ° C at 9 ° C / min similar to the process
And hold at 440 ° C for 50 minutes, then cool at 5 ° C / min.
Evaluation was performed based on the number of broken samples. Table 2 shows the evaluation results under the above conditions.
Data. [0035] [Table 2] As shown in Table 2, the panels A 'according to the present invention,
B 'and C' are the tensile stress values?_ToAre each on average
6.7 MPa, 6.8 MPa and 6.9 MPa;
Ratio σ between tensile stress value and maximum compressive stress value_To/ Σ
_CMAre 0.479, 0.483 and 0.48, respectively.
5 No destruction cases exist. Panel D '
Is the tensile stress value σ_ToIs 7.2 MPa on average, and the ratio is
Rate σ_To/ Σ_CMIs 0.493. 10% destruction example
Exists. On the other hand, the ratio produced by the conventional production method
Panel F 'of Comparative Example 2' has a tensile stress value?_TRIs 1 on average
1.0 MPa and the ratio σ_To/ Σ_CMIs 0.570
It is. Panel F 'is evaluated before destruction before evaluation test
A total of 90% of the samples were destroyed by heating in the test. Further, in the conventional manufacturing method, the side wall 3
Comparison in which the area around the seal edge 3a was kept warm for a short time
The panel E 'of Example 1' has a tensile stress value?_ToIs 7 on average.
6MPa, ratio σ_To/ Σ_CMIs 0.517,
60% is protected from destruction even if thermal stress is applied in the value test,
The effect of heat retention has come out. From the above, it is clear that the cathode ray has been physically strengthened.
For glass panels for pipes, the tensile stress and maximum compression
Force value ratio σ_To/ Σ_CMIs less than 1/2,
Irrespective of the size and face shape of the
High average fracture time and high probability of thermal stress fracture
Even if the maximum compressive stress value is 14MPa or more
It is possible to sufficiently prevent breakage due to thermal stress, and the ratio σ
_To/ Σ_CMIs less than 1/2 and tensile stress T is less than 7MPa
In the case of, the average destruction time due to injury becomes sufficiently large,
It can be seen that breakage due to thermal stress is extremely reduced. [0040] According to the glass panel for a cathode ray tube of the present invention.
If a strong compressive stress layer is formed
Occurs on the outer surface near the seal edge at the corner of the part
Since the tensile stress is kept below the required level,
When manufacturing a pole tube, it is necessary to maintain the required pressure resistance.
If the outer surface of the corner of the side wall is scratched
In addition, the glass panel for the cathode ray tube does not
Shadow when frit sealing the lath panel and funnel
Destruction of the glass panel for the arc tube can be prevented.
It has an excellent effect in practical use. Further, the glass panel for a cathode ray tube according to the present invention.
Is required on the outer surface near the seal edge.
Compressive stress stronger than tensile stress of glass
It is formed on the main part of the panel,
Upper limit of compressive stress value limited by tensile stress
Of the glass panel for the cathode ray tube
It has a remarkable effect of contributing to thinner, lighter and flatter
I do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a glass panel for a cathode ray tube according to the present invention, wherein (A) is a perspective view and (B) is a cross-sectional view of a main part of (A). FIG. 2 is a diagram showing a relationship between a tensile stress and a breaking time of a glass panel for a cathode ray tube. 3A and 3B are explanatory views of a conventional glass panel for a cathode ray tube, wherein FIG. 3A is a perspective view, FIG. 3B is a cutaway view of a main part, FIG. Is an enlarged view of a main part. [Description of Signs] 1 Glass panel for cathode ray tube 2 Face portion 2a Effective screen portion 2b Peripheral edge region 2c Diagonal axial end portion 3 Side wall portion 3a Seal edge portion 3b Outer surface 4 Blend R portion T Tensile stress t Destruction Time σ _To Tensile stress value σ _CM Maximum compressive stress

Claims (1)

(57) [Claim 1] A substantially rectangular face portion provided with an effective screen portion on which an image is projected, and extends in a substantially vertical direction from a peripheral edge of the face portion, and is sealed by another member. A glass panel for a cathode ray tube comprising a side wall having a seal edge portion to be attached, and a compression stress layer formed on at least an outer surface thereof.
The compressive stress value in the peripheral region of the face portion becomes maximum
A compressive stress layer is formed as described above, and a tensile stress value generated on an outer surface near a seal edge portion of the side wall portion extending from a diagonal axis end of the effective screen portion is σ _To ,
Assuming that the maximum compressive stress value of the compressive stress layer measured in the peripheral region of the face portion is σ _CM , the maximum compressive stress value σ _CM and the tensile stress value σ _To satisfy σ _To ≦
A glass panel for a cathode ray tube, having a relationship of 7 MPa, 14 MPa ≦ σ _CM .