CA1195371A - Mask-frame assembly and method of manufacturing the same - Google Patents
Mask-frame assembly and method of manufacturing the sameInfo
- Publication number
- CA1195371A CA1195371A CA000401781A CA401781A CA1195371A CA 1195371 A CA1195371 A CA 1195371A CA 000401781 A CA000401781 A CA 000401781A CA 401781 A CA401781 A CA 401781A CA 1195371 A CA1195371 A CA 1195371A
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- CA
- Canada
- Prior art keywords
- mask
- frame
- frame assembly
- welded
- stress
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Abstract of the Disclosure The invention relates to a mask-frame assembly for use as a color-selecting-electrode system in a color-television tube. The structural features of the mask allow for a simplified method of manufacturing such an assembly. The mask and frame are subjected to a common surface treatment in accordance with a particular temperature program after joining them together at given points by spot welding.
Description
D Berner-R. Reidinger-R. Vollath 1-1-5 (Revision) 3S~7~
MASK-FRAME ASSEMBLY AND METHOD OF
MANUFACTURING THE SAME
Background of the Invention Field of the Invention The present invention relates to a mask-frame assembly for use in a color-selecting-electrode system in color-television tubes, and to a method of manufacturing the same.
Description of the Prior Ar_ In a color-television tube of conventional design, the three electron beams must strike exactly their assigned red, green, and blue phosphor areas on screen. The necessary angle-dependent assignment of the phosphor areas to the electron beams is achieved by means of the so-called mask. For every trio of phosphor areas on the screen, there is one aperture in the mask, which is just behind the screen and parallel to it.
The requirements placed on the positional and dimensional accuracy of such a mask are very stringent, for the proper mask-screen relationship mus~ be achieved over the entire area of the mask during pro-duction and then maintained over the whole life of the tube. In particular, there must be no change in position due to the temperature rise when the set is turned on. The resulting rPquirements can only be fulfilled by optimizing the design of the product and the manufacturing technology used, so that compara~
tively high costs are incurred.
D Berner et al 1-1-5 (Revision) In conventional methods, the mask and its frame are assembled after be.ing blackened separately, so that dimensional changes due to the temperature of about 600 C during blackening can be largely compensated for during assembly. After being assembled by spot welding, the mask-frame assembly is stabllized at about 450~ C to reduce internal stresses in the material which were caused by the welding process. The two thermal treatments of the mask and the frame in separate opera-tions and facilities involve high handling costs andre~uire two furnace installations. The separate stack-ing of masks and frames during the thermal treatments very easily results in distortion of the masks and frames under their dead weight, so that the masks and fra~les cannot be stacked to save factory space and re-duce the amount of equipment required. When the mask and the frame are welded together and the mounting springs are welded on, splashes of welding flux are unavoidable because the surfaces had become poor con-ductors during the blackening process. Another dis-advantage is that t'ne hitherto used maximum temperature during blackening results in a high subsequent deforma-tion ("collapsing"~ of the mask.
Summary of the Invention The aim of the invention is to make such a fabrica-tion process simpler and, thus, more economical. This is achieved by an improvement in design which allows for simplification of the fabrication process. '~he invention centers on the operations necessary to blacken the mask and the frame supporting it~ which may also be called "surface passivation" and serves primarily to prevent corrosion of the sheet iron used, make the sur-faces nonreflecting, and ensure good heat-radiating capacity.
Accordingly, the object of the invention is to provide a simplified manufacturing method which does not have the above disadvantages, and a design of the mask-frame assembly which is suitably improved, particu-larly with regard to the novel manufacturing method.
The inven-tion provides a mask-.Erame assembly for a screen of a color television tube, comprising: a mask in the form of a thin sheet of metal which contains a plurality of apertures;
a bent flange formed about the periphery of -the mask; a frame to which -the mask flange is welded; connecting merrlbers consisting oi bimetallic-spring holders and moun-ting springs welded -to said frarne, wherein said n,etallic-spring holders are welded to said frame to receive said mounting springs anci wherein the neares-t metallic-spring holder weld along the long side of the mask with reference to the cen-ter of the long side of the mask is a-t a distance A from -the center of the side where A is chosen so that 4D5~ A < 2D4 and on the short side of the mask, the dis-tance B
between a metallic-spring weld and the nearest corner of the mask is chosen so that 8D4~ B ~ 3Do that the wid-th C of the flange near an edge where the welds are located,is chosen to be C~ llo6D ~ where D is the length of the screen diagonal; welds also being disposed at the corners of the mask to weld said mask to said frame; and stress-relief means disposed on bo-th sides of -the corner welds for relief of mechanical stress.
The invention also provides a method of manufac-turing a mask and a frame assembly, -the parts of which are welded together~
surface-blackened, and thermally stabilized, comprising the steps of: spo-t welding the mask and the frame; a-ttaching to -the frame bimetalli.c-spring holders and moun-ting springs by welding; and surface-treating and simultaneously thermally stabilizing as a unit -the mask, frame, bimetallic-spring holders, and mounting springs, the thermal treatment being carried out until the mask and the frame have reached a common final temperature TE, and the hea-ting--2a-7~
up process being timed so that the maximum temperature difference between the frame and the mask is less than abou-t 1/3 of the common final temperature TE of 500 -to 600 C and that -the mask-frame assembly is blackened by the use of generator gas as the furnace atmosphere in the surface treatment effected simultaneously with the -thermal stabilization.
-2b-~53~
It was found that the main requirements determin-ing the sequence of operations in the conventional fabrication process are no longer imperative if, according to the invention, the following technical instructions are followed.
The positions of the welds must be chosen so that the internal stresses in the material cause~ during or remaining a~ter the thermal treatment are taken up by permissible deformations which remain within the elastic range. Notches, recesses, and creases must be formed to provide stress relief. If these require-ments are followed, the mask is allowed to optimally compensate for thermal expansion toward all sides without being curved too much, so that the maximum change in position remains sufficiently small when a joint thermal treatment of the mask-frame assembly is carried out.
Brief Description of the Drawings Fig. l shows schematically the operation of a shadow mask.
Fig. 2 shows the assembly of the shadow mask, frame and television tube faceplate.
Fig. 3 shows the distribution of the welds along the flange of the shadow mask.
Figs. 4a and 4b show how the welds are stress-relieved by indentations or cutouts.
Fig. 5 is a cross-sectional view of the mask and frame.
Fig. 6 shows a flowchart of the mask-frame manu-facture according to the invention. The individual process steps are shown by rectangles.
Description of the Invention Referring to Figure 1, there is show~ schema~ically the operation of a shadow mask 1 having apertures 2 through which electron beams 3 strike selected phosphor areas 4 formed on an inner surface 5 of a faceplate 8, Figure 2 shows the shadow mask 1 having a flange 13 mounted to a frame 6. Frame 6 is provided with connect-ing members 7 consisting of bimetallic spring holders 7a and mounting springs 7b. The connecting members 7 function ` :
D. Berner e~ al 1-1-5 ~ ~7 ~ (Revision) to moun~ the shadow mask frame assembly within the faceplate 8 of a televisi.on tube.
Referring to Figures 4a, 4b and 5, the shadow mask l is sho~l to have indentations 10 as shown particularly in Figure 4a or cutou~s 11 as shown particularly in 4b formed in the flange 13 for the purpose of stress rellef.
In addition, a crease 12 is formed about the periphery of the shad~w mask for the purpose of compensatin~ for thermal expansion. The location of welds 9 along the flange 13 of mask 1 for attaching the mask to the frame 6 are shown in Figure 3.
Re~erring specifically to Figure 3, the distance A
between the center of the long side of the mask and the nearest weld 9 is chosen so that 4D5 is less than or equal to A, which is less than or equal to 2.4 where D
is the diagonal dimenslon across the shadow mask. ~n the short side of the mask, the distanee B between the weld 9 and the nearest corner of the mask is chosen so ~ that ~ is equal to or less than B, which is equal to or less than 3Ø The width C of the flange 13 near ~he edge 14 on which the welds are located is chosen so that C is equal to or greater than ~
The welds 9 at the corners of the mask are relieved of mechanical stress by the stress release means 10 or ll formed on each side of said weld as shown in Figures 4a and 4b.
Turning now to the unique method of asse~bly of the mask frame and faceplate, Figure ~ shows that in Step 15, the frame is washed and degreased. According to the invention, blackening, Step 16, is performed together with the stabilizing of the welded parts 1, 6, and 7 in Step 23. In Step 17, three connecting members 7 are welded onto the frame. The mask 1 is first processed in the conventional manner by heating as shown in Step 18, rolling as shown in Step 19 and drawing as shown ln Step 20. After the mask is washed as shown in Step 21, the mask 1 is secured by spot welding in Step 22.
This is followed by the joint heat treatment for blacken-ing and simultaneous stabilization, Step 23.
, D. Berner et al 1-1-5 7~ (Revision~
The assembled mask 1, frame 6, bimetalllc spring holders 7a and mounting springs 7b are in Step 23 simultaneously surface-treated and thermally stabilized, with the treatment being carried out until the mask and the frarne have reached a common final temperature T~, and the heating up process being timed so that the maximum temperature difference between the frame and the mask is less than about 1/3 of the final temperature TE, which temperature is within the range of 5~0 to 600 C and preferably 570 to 580 C. The mask frame assembly is blackened by the use of a generator gas in the furnace atmosphere so that surface treatment is accomplished simultaneously with the thermal stabiliza-tion. The passivation step may also include passiva-tion in the presence of 2 to 3 percent oxygen. It is preferable that after the stabilization and surface treatment is accomplished, the cooling of the mask frame assembly be accelerated so that the temperature of the frame falls below TE within approximately four minutes so that the bimetal does not excessively change its properties. Step 24 designates the insertion into the glass faceplate 8 and the attachment of the fourth connecting member. The fabrication process then con-tinues with the coating of the screen, Step 25.
Each of the connecting members 7 consists of a bimetallic~spring holder 7a and a mounting spring 7b.
The fourth mounting spring is not welded on until after the simultaneous blackening and stabili~ing process.
All other welds can be made by spot welding prior to the blackening of the parts to be joined. This gi~es stronger welds and has the big advantage that there are hardly any splashes of welding flux which could settle in the apertures of the mask.
The process step hitherto required to stress-relieve the mask and the frame as well as the contirluous furnace necessary thereor can be dispensed with because, in accordance with the invention, the maxi~.um temperature during the black~ning of the welded mask-frame assembly is limited preferably to 5~0~ C, and :!
D Berner et al l-1-5 ~ ~3~ 3~ ~ (Revision) because this temperature acts on the mask only until the frame is at t~e same temperature. By narrowing down the process parameters, the deformations of the mask ("collapsing") and the frame distortion are kept so small (maximum dimensional variations: 0.3 mm) that they can be received by the mask-frame assembly in the elastic range within permissible limits. To compensate for the small amount of deformati.on referred to as "collapsing", i.e., to ensure the desired mask contour of the finished product, this remaining dimensional variation is allowed for in the design of the mask-stamping die. The stress relief caused during the blackening of the welded mask-frame assembly results in sufficient aging of the metal parts. Fig. 6 shows how the "blackening-stabilizing" step is integrated in the sequences of operations for manufacturing the mask-frame assembly. The rectangles 16 indicate where the blackening takes place in conventional fabrication - processes, and the arrows indicate where this process step, hitherto performed separately for the mas~ and the frame, is now carried out as a single operation.
The simplification of and improvement on the prior art method is thus made possible by the design shown in Figs. 1 to 5, particularly the design of the mask and the suitable choice of its dimensions and of the positions of the welds. The slightly curved mask 1 is designed to take strains in the elastic range which are caused during manufacture and opera-tion, while deformations and changes of position are kept to a minimum. This is achieved by suitable choice of ~, B, and C (see Figs. 3 and 4) and by pro-viding stress-relieving means in the form o~ indenta-tions 10, cutouts 11, the circumferential groove 12, and the flange 13 ("skirt"), which serve to take strains.
It is not always advantageous to make all welded joints;
particularly those near ~he edges may be omitted under certain circu~stances.
If the distances A, B, and C are chosen as claimed, and the-joints are not too close together ~ 3~ ~ D. Berner et al 1-1-5 and too close to corners and edges, sufficient elasticity is ensured. Thus, by suitable choice of the positions of joints and stress-relief points, the displacement of the mask during manufacture and opera-tion is kept so small that an improved and simplifiedsequence of operations is possible during the manufac-ture of the mask and the support frame.
PCV:jn March 9, 1982
MASK-FRAME ASSEMBLY AND METHOD OF
MANUFACTURING THE SAME
Background of the Invention Field of the Invention The present invention relates to a mask-frame assembly for use in a color-selecting-electrode system in color-television tubes, and to a method of manufacturing the same.
Description of the Prior Ar_ In a color-television tube of conventional design, the three electron beams must strike exactly their assigned red, green, and blue phosphor areas on screen. The necessary angle-dependent assignment of the phosphor areas to the electron beams is achieved by means of the so-called mask. For every trio of phosphor areas on the screen, there is one aperture in the mask, which is just behind the screen and parallel to it.
The requirements placed on the positional and dimensional accuracy of such a mask are very stringent, for the proper mask-screen relationship mus~ be achieved over the entire area of the mask during pro-duction and then maintained over the whole life of the tube. In particular, there must be no change in position due to the temperature rise when the set is turned on. The resulting rPquirements can only be fulfilled by optimizing the design of the product and the manufacturing technology used, so that compara~
tively high costs are incurred.
D Berner et al 1-1-5 (Revision) In conventional methods, the mask and its frame are assembled after be.ing blackened separately, so that dimensional changes due to the temperature of about 600 C during blackening can be largely compensated for during assembly. After being assembled by spot welding, the mask-frame assembly is stabllized at about 450~ C to reduce internal stresses in the material which were caused by the welding process. The two thermal treatments of the mask and the frame in separate opera-tions and facilities involve high handling costs andre~uire two furnace installations. The separate stack-ing of masks and frames during the thermal treatments very easily results in distortion of the masks and frames under their dead weight, so that the masks and fra~les cannot be stacked to save factory space and re-duce the amount of equipment required. When the mask and the frame are welded together and the mounting springs are welded on, splashes of welding flux are unavoidable because the surfaces had become poor con-ductors during the blackening process. Another dis-advantage is that t'ne hitherto used maximum temperature during blackening results in a high subsequent deforma-tion ("collapsing"~ of the mask.
Summary of the Invention The aim of the invention is to make such a fabrica-tion process simpler and, thus, more economical. This is achieved by an improvement in design which allows for simplification of the fabrication process. '~he invention centers on the operations necessary to blacken the mask and the frame supporting it~ which may also be called "surface passivation" and serves primarily to prevent corrosion of the sheet iron used, make the sur-faces nonreflecting, and ensure good heat-radiating capacity.
Accordingly, the object of the invention is to provide a simplified manufacturing method which does not have the above disadvantages, and a design of the mask-frame assembly which is suitably improved, particu-larly with regard to the novel manufacturing method.
The inven-tion provides a mask-.Erame assembly for a screen of a color television tube, comprising: a mask in the form of a thin sheet of metal which contains a plurality of apertures;
a bent flange formed about the periphery of -the mask; a frame to which -the mask flange is welded; connecting merrlbers consisting oi bimetallic-spring holders and moun-ting springs welded -to said frarne, wherein said n,etallic-spring holders are welded to said frame to receive said mounting springs anci wherein the neares-t metallic-spring holder weld along the long side of the mask with reference to the cen-ter of the long side of the mask is a-t a distance A from -the center of the side where A is chosen so that 4D5~ A < 2D4 and on the short side of the mask, the dis-tance B
between a metallic-spring weld and the nearest corner of the mask is chosen so that 8D4~ B ~ 3Do that the wid-th C of the flange near an edge where the welds are located,is chosen to be C~ llo6D ~ where D is the length of the screen diagonal; welds also being disposed at the corners of the mask to weld said mask to said frame; and stress-relief means disposed on bo-th sides of -the corner welds for relief of mechanical stress.
The invention also provides a method of manufac-turing a mask and a frame assembly, -the parts of which are welded together~
surface-blackened, and thermally stabilized, comprising the steps of: spo-t welding the mask and the frame; a-ttaching to -the frame bimetalli.c-spring holders and moun-ting springs by welding; and surface-treating and simultaneously thermally stabilizing as a unit -the mask, frame, bimetallic-spring holders, and mounting springs, the thermal treatment being carried out until the mask and the frame have reached a common final temperature TE, and the hea-ting--2a-7~
up process being timed so that the maximum temperature difference between the frame and the mask is less than abou-t 1/3 of the common final temperature TE of 500 -to 600 C and that -the mask-frame assembly is blackened by the use of generator gas as the furnace atmosphere in the surface treatment effected simultaneously with the -thermal stabilization.
-2b-~53~
It was found that the main requirements determin-ing the sequence of operations in the conventional fabrication process are no longer imperative if, according to the invention, the following technical instructions are followed.
The positions of the welds must be chosen so that the internal stresses in the material cause~ during or remaining a~ter the thermal treatment are taken up by permissible deformations which remain within the elastic range. Notches, recesses, and creases must be formed to provide stress relief. If these require-ments are followed, the mask is allowed to optimally compensate for thermal expansion toward all sides without being curved too much, so that the maximum change in position remains sufficiently small when a joint thermal treatment of the mask-frame assembly is carried out.
Brief Description of the Drawings Fig. l shows schematically the operation of a shadow mask.
Fig. 2 shows the assembly of the shadow mask, frame and television tube faceplate.
Fig. 3 shows the distribution of the welds along the flange of the shadow mask.
Figs. 4a and 4b show how the welds are stress-relieved by indentations or cutouts.
Fig. 5 is a cross-sectional view of the mask and frame.
Fig. 6 shows a flowchart of the mask-frame manu-facture according to the invention. The individual process steps are shown by rectangles.
Description of the Invention Referring to Figure 1, there is show~ schema~ically the operation of a shadow mask 1 having apertures 2 through which electron beams 3 strike selected phosphor areas 4 formed on an inner surface 5 of a faceplate 8, Figure 2 shows the shadow mask 1 having a flange 13 mounted to a frame 6. Frame 6 is provided with connect-ing members 7 consisting of bimetallic spring holders 7a and mounting springs 7b. The connecting members 7 function ` :
D. Berner e~ al 1-1-5 ~ ~7 ~ (Revision) to moun~ the shadow mask frame assembly within the faceplate 8 of a televisi.on tube.
Referring to Figures 4a, 4b and 5, the shadow mask l is sho~l to have indentations 10 as shown particularly in Figure 4a or cutou~s 11 as shown particularly in 4b formed in the flange 13 for the purpose of stress rellef.
In addition, a crease 12 is formed about the periphery of the shad~w mask for the purpose of compensatin~ for thermal expansion. The location of welds 9 along the flange 13 of mask 1 for attaching the mask to the frame 6 are shown in Figure 3.
Re~erring specifically to Figure 3, the distance A
between the center of the long side of the mask and the nearest weld 9 is chosen so that 4D5 is less than or equal to A, which is less than or equal to 2.4 where D
is the diagonal dimenslon across the shadow mask. ~n the short side of the mask, the distanee B between the weld 9 and the nearest corner of the mask is chosen so ~ that ~ is equal to or less than B, which is equal to or less than 3Ø The width C of the flange 13 near ~he edge 14 on which the welds are located is chosen so that C is equal to or greater than ~
The welds 9 at the corners of the mask are relieved of mechanical stress by the stress release means 10 or ll formed on each side of said weld as shown in Figures 4a and 4b.
Turning now to the unique method of asse~bly of the mask frame and faceplate, Figure ~ shows that in Step 15, the frame is washed and degreased. According to the invention, blackening, Step 16, is performed together with the stabilizing of the welded parts 1, 6, and 7 in Step 23. In Step 17, three connecting members 7 are welded onto the frame. The mask 1 is first processed in the conventional manner by heating as shown in Step 18, rolling as shown in Step 19 and drawing as shown ln Step 20. After the mask is washed as shown in Step 21, the mask 1 is secured by spot welding in Step 22.
This is followed by the joint heat treatment for blacken-ing and simultaneous stabilization, Step 23.
, D. Berner et al 1-1-5 7~ (Revision~
The assembled mask 1, frame 6, bimetalllc spring holders 7a and mounting springs 7b are in Step 23 simultaneously surface-treated and thermally stabilized, with the treatment being carried out until the mask and the frarne have reached a common final temperature T~, and the heating up process being timed so that the maximum temperature difference between the frame and the mask is less than about 1/3 of the final temperature TE, which temperature is within the range of 5~0 to 600 C and preferably 570 to 580 C. The mask frame assembly is blackened by the use of a generator gas in the furnace atmosphere so that surface treatment is accomplished simultaneously with the thermal stabiliza-tion. The passivation step may also include passiva-tion in the presence of 2 to 3 percent oxygen. It is preferable that after the stabilization and surface treatment is accomplished, the cooling of the mask frame assembly be accelerated so that the temperature of the frame falls below TE within approximately four minutes so that the bimetal does not excessively change its properties. Step 24 designates the insertion into the glass faceplate 8 and the attachment of the fourth connecting member. The fabrication process then con-tinues with the coating of the screen, Step 25.
Each of the connecting members 7 consists of a bimetallic~spring holder 7a and a mounting spring 7b.
The fourth mounting spring is not welded on until after the simultaneous blackening and stabili~ing process.
All other welds can be made by spot welding prior to the blackening of the parts to be joined. This gi~es stronger welds and has the big advantage that there are hardly any splashes of welding flux which could settle in the apertures of the mask.
The process step hitherto required to stress-relieve the mask and the frame as well as the contirluous furnace necessary thereor can be dispensed with because, in accordance with the invention, the maxi~.um temperature during the black~ning of the welded mask-frame assembly is limited preferably to 5~0~ C, and :!
D Berner et al l-1-5 ~ ~3~ 3~ ~ (Revision) because this temperature acts on the mask only until the frame is at t~e same temperature. By narrowing down the process parameters, the deformations of the mask ("collapsing") and the frame distortion are kept so small (maximum dimensional variations: 0.3 mm) that they can be received by the mask-frame assembly in the elastic range within permissible limits. To compensate for the small amount of deformati.on referred to as "collapsing", i.e., to ensure the desired mask contour of the finished product, this remaining dimensional variation is allowed for in the design of the mask-stamping die. The stress relief caused during the blackening of the welded mask-frame assembly results in sufficient aging of the metal parts. Fig. 6 shows how the "blackening-stabilizing" step is integrated in the sequences of operations for manufacturing the mask-frame assembly. The rectangles 16 indicate where the blackening takes place in conventional fabrication - processes, and the arrows indicate where this process step, hitherto performed separately for the mas~ and the frame, is now carried out as a single operation.
The simplification of and improvement on the prior art method is thus made possible by the design shown in Figs. 1 to 5, particularly the design of the mask and the suitable choice of its dimensions and of the positions of the welds. The slightly curved mask 1 is designed to take strains in the elastic range which are caused during manufacture and opera-tion, while deformations and changes of position are kept to a minimum. This is achieved by suitable choice of ~, B, and C (see Figs. 3 and 4) and by pro-viding stress-relieving means in the form o~ indenta-tions 10, cutouts 11, the circumferential groove 12, and the flange 13 ("skirt"), which serve to take strains.
It is not always advantageous to make all welded joints;
particularly those near ~he edges may be omitted under certain circu~stances.
If the distances A, B, and C are chosen as claimed, and the-joints are not too close together ~ 3~ ~ D. Berner et al 1-1-5 and too close to corners and edges, sufficient elasticity is ensured. Thus, by suitable choice of the positions of joints and stress-relief points, the displacement of the mask during manufacture and opera-tion is kept so small that an improved and simplifiedsequence of operations is possible during the manufac-ture of the mask and the support frame.
PCV:jn March 9, 1982
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A mask-frame assembly for a screen of a color television tube, comprising:
a mask in the form of a thin sheet of metal which con-tains a plurality of apertures;
a bent flange formed about the periphery of the mask;
a frame to which the mask flange is welded;
connecting members consisting of bimetallic-spring holders and mounting springs welded to said frame, wherein said metallic-spring holders are welded to said frame to receive said mounting springs and wherein the nearest metallic-spring holder weld along the long side of the mask with reference to the center of the long side of the mask is at a distance A from the center of the side where A is chosen so that and on the short side of the mask, the distance B between a metallic-spring weld and the nearest corner of the mask is chosen so that that the width C of the flange near an edge where the welds are located, is chosen to be , where D is the length of the screen diagonal;
welds also being disposed at the corners of the mask to weld said mask to said frame; and stress-relief means disposed on both sides of the corner welds for relief of mechanical stress.
a mask in the form of a thin sheet of metal which con-tains a plurality of apertures;
a bent flange formed about the periphery of the mask;
a frame to which the mask flange is welded;
connecting members consisting of bimetallic-spring holders and mounting springs welded to said frame, wherein said metallic-spring holders are welded to said frame to receive said mounting springs and wherein the nearest metallic-spring holder weld along the long side of the mask with reference to the center of the long side of the mask is at a distance A from the center of the side where A is chosen so that and on the short side of the mask, the distance B between a metallic-spring weld and the nearest corner of the mask is chosen so that that the width C of the flange near an edge where the welds are located, is chosen to be , where D is the length of the screen diagonal;
welds also being disposed at the corners of the mask to weld said mask to said frame; and stress-relief means disposed on both sides of the corner welds for relief of mechanical stress.
2. A mask-frame assembly as described in claim 1, wherein the stress-relief means are indentations.
3. A mask-frame assembly as described in claim 1, wherein 8.
the stress-relief means are cutouts.
the stress-relief means are cutouts.
4. A method of manufacturing a mask and a frame assembly the parts of which are welded together, surface-blackened, and thermally stabilized, comprising the steps of:
spot welding the mask and the frame;
attaching to the frame bimetallic-spring holders and mounting springs by welding; and surface-treating and simultaneously thermally stabilizing as a unit the mask, frame, bimetallic spring holders, and mounting springs, the thermal treatment being carried out until the mask and the frame have reached a common final temperature TE, and the heating-up process being timed so that the maximum temperature difference between the frame and the mask is less than about 1/3 of the common final temperature TE of 500 to 600° C and that the mask-frame assembly is blackened by the use of generator gas as the furnace atmosphere in the surface treatment effected simultaneously with the thermal stabilization.
spot welding the mask and the frame;
attaching to the frame bimetallic-spring holders and mounting springs by welding; and surface-treating and simultaneously thermally stabilizing as a unit the mask, frame, bimetallic spring holders, and mounting springs, the thermal treatment being carried out until the mask and the frame have reached a common final temperature TE, and the heating-up process being timed so that the maximum temperature difference between the frame and the mask is less than about 1/3 of the common final temperature TE of 500 to 600° C and that the mask-frame assembly is blackened by the use of generator gas as the furnace atmosphere in the surface treatment effected simultaneously with the thermal stabilization.
5. A method as described in claim 4, wherein the mask-frame assembly is additionally passivated in the presence of 2 to 3%
oxygen.
oxygen.
6. A method as described in one of claims 4 or 5, wherein after the stabilization and the surface treatment, the cooling of the mask-frame assembly is accelerated by suitable reduction of the heating power in the furnace and suitable choice of the time of removal from the furnace that the temperature of the frame falls below ? within about 4 minutes, so that the bimetal does not 9.
excessively change its properties.
excessively change its properties.
7. A method as described in claim 4, wherein temperature TE
is in the range of 570 to 580° C.
10.
is in the range of 570 to 580° C.
10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000401781A CA1195371A (en) | 1982-04-27 | 1982-04-27 | Mask-frame assembly and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000401781A CA1195371A (en) | 1982-04-27 | 1982-04-27 | Mask-frame assembly and method of manufacturing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1195371A true CA1195371A (en) | 1985-10-15 |
Family
ID=4122670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000401781A Expired CA1195371A (en) | 1982-04-27 | 1982-04-27 | Mask-frame assembly and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1195371A (en) |
-
1982
- 1982-04-27 CA CA000401781A patent/CA1195371A/en not_active Expired
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