US3909928A
Expired / Lapsed
US
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Method for manufacturing a shadow mask
Assignee: Hitachi Ltd
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Filing: 1974-02-21
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Granted: 1975-10-07
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Expires: 1994-02-21
Abstract
Abstract In this invention, a sheet steel is annealed and is subjected to skin-pass rolling of a reduction of 0.5-15% before forming a desired pattern of small holes therein with an etching (i.e. photoetching) method, thereby to provide a sheet steel having no elongation of the yield point and being slow in aging and to decrease the thermal deformation of the shadow mask by applying the residual stress occurring therein due to the skin-pass rolling.
Inventors
- 👤 Kazuo Sato
- 👤 Soji Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:40
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/14; H01J9/142; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/496; Y10T29/49995; Y10T29/49996
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
71 words
A METHOD FOR MANUFACTURING A SHADOW MASK. COMPRISING A FIRST STEP OF ANNEALING A MATERIAL OF LOW-CARBON SHEET STEEL, A SECOND STEP OF THEREAFTER SUBJECTING THE ANNEALED SHEET STEEL TO SKIN-PASS ROLLING FOR A REDUCTION OF 0.5 - 15% IN THICKNESS THEREBY PROVIDING A PREDETERMINED THICKNESS, A THIRD STEP OF THEREAFTER FORMING HOLES IN THE SHEET STEEL, AND A FOURTH STEP OF THEREAFTER PRESS-FORMING THE SHEET STEEL INTO A DESIRED PLANE
Claim 2
Independent Claim
71 words
A METHOD FOR MANUFACTURING A SHADOW MASK. COMPRISING A FIRST STEP OF ANNEALING A MATERIAL OF LOW-CARBON SHEET STEEL, A SECOND STEP OF THEREAFTER SUBJECTING THE ANNEALED SHEET STEEL TO SKIN-PASS ROLLING FOR A REDUCTION OF 0.5 - 15% IN THICKNESS THEREBY PROVIDING A PREDETERMINED THICKNESS, A THIRD STEP OF THEREAFTER FORMING HOLES IN THE SHEET STEEL, AND A FOURTH STEP OF THEREAFTER PRESS-FORMING THE SHEET STEEL INTO A DESIRED PLANE
Claim 3
Dependent Claim
28 words
The method of claim 1, wherein said first step comprises a step of annealing at a low temperature a material of low-carbon sheet steel subjected to cold rolling.
Claim 4
Dependent Claim
28 words
The method of claim 2, wherein the annealing is conducted from 550* - 650*C. for a period of from 10 minutes to 8 hours under an inert gas.
Claim 5
Dependent Claim
68 words
The method of claim 1, wherein said second step comprises a step of subjecting said sheet steel to the skin-pass rolling of the reduction of 0.5 - 15% to bring the sheet steel into the predetermined thickness and to give rise to a residual stress distribution which consists of compressions at both surface layer parts of said sheet steel and a tension at a central layer part thereof.
Claim 6
Dependent Claim
79 words
The method of claim 1, wherein said third step comprises a step of perforating said sheet steel by etching by which the holes are so formed as to be larger on one surface side than on the other surface side, thereby giving rise to a residual stress distribution which consists of a great compression on the smaller hole side and null stress and a tension over from the surface on the larger hole side to said central layer part.
Claim 7
Dependent Claim
28 words
The method of claim 1, wherein the sheet steel has a carbon content of not more than 0.1% and an initial thickness ranging from 0.1 to 0.3 mm.
Claim 8
Independent Claim
167 words
A method for manufacturing a shadow mask, comprising the step of annealing at a low temperature a material of low-carbon sheet steel subjected to cold rolling, the step of thereafter subjecting the sheet steel to skin-pass rolling of a reduction of 0.5 - 15% to thus bring it into a predetermined thickness and give rise to a residual stress distribution which consists of compressions at both surface layer parts of said sheet steel and a tension at a central layer part thereof, the step of thereafter forming holes in said sheet steel by etching wherein said holes are made larger on one surface side than on the other surface side of said sheet steel, thereby giving rise to a residual stress distribution which consists of a great compression on the smaller hole side and null stress and a tension over from the surface on the larger hole side to said central layer part, and the step of thereafter press-forming the sheet steel into a desired curved plane.
Claim 9
Independent Claim
167 words
A method for manufacturing a shadow mask, comprising the step of annealing at a low temperature a material of low-carbon sheet steel subjected to cold rolling, the step of thereafter subjecting the sheet steel to skin-pass rolling of a reduction of 0.5 - 15% to thus bring it into a predetermined thickness and give rise to a residual stress distribution which consists of compressions at both surface layer parts of said sheet steel and a tension at a central layer part thereof, the step of thereafter forming holes in said sheet steel by etching wherein said holes are made larger on one surface side than on the other surface side of said sheet steel, thereby giving rise to a residual stress distribution which consists of a great compression on the smaller hole side and null stress and a tension over from the surface on the larger hole side to said central layer part, and the step of thereafter press-forming the sheet steel into a desired curved plane.
Claim 10
Dependent Claim
28 words
The method of claim 7, wherein the sheet steel has a carbon content not more than 0.1% by weight and a thickness of from 0.1 to 0.3 mm.
Claim 11
Dependent Claim
27 words
The method of claim 8, wherein annealing is conducted at 550*C. to 650*C. for a period of from 10 minutes to 8 hours under an inert gas.
Claim 12
Dependent Claim
61 words
The method of claim 1, wherein the sheet steel has a carbon content of not more than 0.1% and an initial thickness ranging from 0.1 to 0.3 mm; the annealing is conducted from 550* - 650*C. for a period of from 10 minutes to 8 hours under an inert gas; and the holes are formed in the sheet steel by etching.
Claim 13
Dependent Claim
27 words
The method of claim 1, wHerein the desired plane formed by press-forming said sheet steel is a curved plane having bending moments exerted thereon which suppress expansion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |