US3558955A - Self supporting shadow mask with reinforcing ribs and gusset plates for colored television picture tubes - Google Patents

Self supporting shadow mask with reinforcing ribs and gusset plates for colored television picture tubes Download PDF

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Publication number
US3558955A
US3558955A US821056A US3558955DA US3558955A US 3558955 A US3558955 A US 3558955A US 821056 A US821056 A US 821056A US 3558955D A US3558955D A US 3558955DA US 3558955 A US3558955 A US 3558955A
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US
United States
Prior art keywords
plate members
section
mask
flange
gusset plate
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.)
Expired - Lifetime
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US821056A
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English (en)
Inventor
Myron C Kirchner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NORTHERN METAL PRODUCTS Inc
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NORTHERN METAL PRODUCTS Inc
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/06—Screens for shielding; Masks interposed in the electron stream
    • H01J29/07—Shadow masks for colour television tubes
    • H01J29/073—Mounting arrangements associated with shadow masks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/07—Shadow masks
    • H01J2229/0722—Frame
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/07—Shadow masks
    • H01J2229/0727—Aperture plate
    • H01J2229/0766—Details of skirt or border
    • H01J2229/0772—Apertures, cut-outs, depressions, or the like

Definitions

  • Lafranchi Attorney-Stryker and Jacobson ABSTRACT A shadow mask for colored TV picture tubes foraminous or translucent area formed by a multitude of miniature through which electron beams [54] SELF SUPPORTING SHADOW MASK WITH has a front section, containing the conventional REINFORCING RIBS AND GUSSET PLATES FOR COLORED TELEVISION PICTURE TUBES Figs apertures pass from the electron guns at the rear of the tube to the viewing face at the front of the tube;
  • the flange contains a plurali [50] Field of Search.
  • the present invention is somewhat of a variation or modification of the aperture mask described in the aforementioned copending application.
  • the mask contains the conventional translucent area surrounded by an imperforate marginal area, has a rearward extending imperforate wall and an inward extending flange at the rear edge of the wall. Numerous strengthening ribs are in the various imperforate sections to assist in providing enough strength to make the mask self supporting. Fragmentary gusset plate members are welded at strategic locations on the flange to provide additional strengthening while keeping the weight and mass of the mask at a minimum.
  • a mask of this nature not only warms up to uniform operating temperature quickly but also is rigid enough to withstand normal handling without any significant shift in the location of the tiny apertures.
  • Masks of this nature can be attached to the glass bulb by springlike mounting tabs located on the wall section and containing openings for mating with mounting studs in the glass bulb.
  • FIG. 1 is a rear view of a shadow mask for a colored TV picture tube constructed according to the teachings of this invention
  • FIG. 2 is a side view of the shadow mask
  • FIG. 3 is a sectional view taken along viewing line 3-3 of FIG. 1.
  • the aperture or shadow mask contains the conventional foraminous or translucent area formed by a myriad of apertures which are usually chemically milled through a thin sheet of metal, such as stainless steel.
  • the translucent section 10 of the shadow mask is located near and facing the front viewing face to of the picture tube and is between the viewing face and electron guns at the rear of the tube.
  • the electron beams are directed through the translucent area 10 to impinge upon colored phosphor dots on the inside of the face of the picture tube.
  • the shadow mask is also used during the process of laying down the colored phosphor dots in conventional triad patterns.
  • the mask ordinarily is removed and repositioned with respect to the face of the picture tube a number of times so it is important that the mask be stable enough so that the tiny apertures return virtually to their same previous location each time the mask it is temporarily removed and reinserted. It should also be apparent that the mask should be temperature stable so that the miniature apertures in the translucent area do not shift with respect to the phosphor dots on the industry face plate to interfere with the passage of the electron beams directed toward the face plate.
  • the translucent area 10 is partially domed or curved, usually aspherically, to conform to the shape of the inner face of the picture tube.
  • Various methods, procedures and equipments have been developed and are used today throughout the industry for etching out the translucent areas and for doming or curving the mask face as desired. These methods, procedures and equipments are not considered part of the present invention.
  • a marginal imperforate area 11 Surrounding the translucent area 10 is a marginal imperforate area 11 which is merely an extension of the same sheet of metal from which the translucent area is formed.
  • marginal area 11 near the outer edge of the translucent area 10, there is formed a continuous, inwardprojecting shallow groove 12 which serves as a strengthening rib for the front portion of the aperture mask. Ordinarily, this rib is formed in a press using standard well-known techniques.
  • the metal sheet bends rearward to form an imperforated wall section 13 which extends completely around the front portion of the mask. The depth of the wall section 13, Le.
  • the mask may vary from mask to mask depending upon a number of factors ineluding, but not limited to, the size an and the type of the picture tube for which the mask is being made.
  • the mask is referred to as being deep-drawn as differentiated from a shallow-drawn mask which has a very short wall section.
  • the wall may be in the order of l inches deep for an aperture mask used in a 21 or 24 inch picture tube.
  • a shallow, inwardly directed groove 14 which extends continuously around wall 13 provides a strengthening rib for the wall section. The location and size of strengthening rib 14 depends on a number of factors including the size of the mask, the dimension of the wall, the metal thickness, etc.
  • flange 16 At the rear edge of wall l3 the metal sheet bends inward to form flange 16 in a plane which is substantially at to the central axis of the aperture mask.
  • the dimension of flange I6 also depends on a number of different factors but suffice is to point out that it should not extend inward so far as to interfere with the passage of the electron beams from the electron guns to the viewing face of the tube.
  • the inner edge of flange 16 may be flared angularly as illustrated at 18, to provide some degree of shielding.
  • flange I6 is in a rectangular geometric form corresponding in general with the geometric form of the aperture mask for use with a rectangular picture tube. Attached securely to the four corners of flange 16 are reinforcing gusset plate members 19.
  • the gusset plate members are attached by welding them to the flange.
  • the gusset plates 19 are made out of the same type of metal as the rest of the mask and dimensionally may be the same thickness as the metal sheet from which the mask is formed. However, it has been found preferable that the gusset plate members 19 be in the order of twice the thickness of the flange material. Although it has been found that in most instances the corner-located gusset plate members 19 provide sufficient strengthening for the desired results, in some instances it may be necessary or desirable to enhance the strength of the mask by welding additional girsset plate members at suitable locations between corner gusset members.
  • fragments of metal similar to gusset plate members 19 may be welded to flange 16 at the center of each of the sides of the flange.
  • the sizes of these additional gusset plate members may be selected according to the degree of additional strength desired while keeping in mind the necessity of keeping the mass and the weight of the mask structure at a minimum.
  • wall 13 may be provided with additional strengthening and supporting ribs 23 which run across the continuous rib 14.
  • the number. dimensions and the spacing of these cross ribs 23 again is a matter of choice depending on a number of factors and can be selected by the artisan familiar with construction of masks of this nature.
  • Attached to the outside of wall 13 are springlike mounting tabs 20 which contains openings 21 on tongue portions 22 for mating with pins (not shown) extending out from the glass bulb of the picture tube.
  • the mask Because of the inherent strength of the mask brought about by the supporting ribs in conjunction with the suitably located gusset plate members, it can be used in the phosphor dot forming process and be mounted as part of the final assembly of a the picture tube and remain secure in this virtually self-supporting manner without the need of the usual heavy, rigid supporting rings and mounts which had been commonplace heretofore.
  • a self-supporting shadow mask for a colored television picture tube comprising: a thin metal sheet having a front section containing a translucent area defined by a myriad of miniature apertures through the metal sheet and an imperforate margin area surrounding the translucent area with a continuous strengthening rib formed in said margin area, an imperforate wall section extending rearward from the edge of said from section, said wall section containing strengthening ribs formed therein, a flange section directed inwardly from the back edge of said wall section, said flange section being generally rectangular in shape; and fragmentary gusset plate members rigidly attached to said flange section at its four corners.
  • gusset plate members are made from metal having the same characteristics as the mask metal and range up to three times its thickness, said gusset plate members being welded to the flange section.

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US821056A 1969-05-01 1969-05-01 Self supporting shadow mask with reinforcing ribs and gusset plates for colored television picture tubes Expired - Lifetime US3558955A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US82105669A 1969-05-01 1969-05-01

Publications (1)

Publication Number Publication Date
US3558955A true US3558955A (en) 1971-01-26

Family

ID=25232383

Family Applications (1)

Application Number Title Priority Date Filing Date
US821056A Expired - Lifetime US3558955A (en) 1969-05-01 1969-05-01 Self supporting shadow mask with reinforcing ribs and gusset plates for colored television picture tubes

Country Status (6)

Country Link
US (1) US3558955A (fr)
BE (1) BE749492A (fr)
DE (1) DE1947432A1 (fr)
FR (1) FR2046087A5 (fr)
GB (1) GB1227894A (fr)
NL (1) NL7006115A (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3700949A (en) * 1971-01-21 1972-10-24 Nippon Electric Co Color television picture tube
US3912963A (en) * 1973-09-07 1975-10-14 Zenith Radio Corp Color crt having shadow mask with forwardly directed, outwardly flared skirt
US20070221591A1 (en) * 2006-03-24 2007-09-27 Yang-Yuan Hsu Wedged sliding trough structure

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2897392A (en) * 1956-02-09 1959-07-28 Zenith Radio Corp Color television tube mask and frame assembly
US3351996A (en) * 1965-03-29 1967-11-14 Rauland Corp Method of making a rectangular-mask assembly for a shadow-mask type of color tube
US3479546A (en) * 1968-06-11 1969-11-18 Buckbee Mears Co Self-supporting shadow mask for colored tv picture tubes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2897392A (en) * 1956-02-09 1959-07-28 Zenith Radio Corp Color television tube mask and frame assembly
US3351996A (en) * 1965-03-29 1967-11-14 Rauland Corp Method of making a rectangular-mask assembly for a shadow-mask type of color tube
US3479546A (en) * 1968-06-11 1969-11-18 Buckbee Mears Co Self-supporting shadow mask for colored tv picture tubes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3700949A (en) * 1971-01-21 1972-10-24 Nippon Electric Co Color television picture tube
US3912963A (en) * 1973-09-07 1975-10-14 Zenith Radio Corp Color crt having shadow mask with forwardly directed, outwardly flared skirt
US20070221591A1 (en) * 2006-03-24 2007-09-27 Yang-Yuan Hsu Wedged sliding trough structure

Also Published As

Publication number Publication date
BE749492A (fr) 1970-10-01
DE1947432A1 (de) 1970-11-05
FR2046087A5 (fr) 1971-03-05
NL7006115A (fr) 1970-11-03
GB1227894A (fr) 1971-04-07

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KR900005932B1 (ko) 개선된 새도우 마스크를 가진 칼라 수상관