US3484638A - Shadow mask mounted in glass envelope of color tv picture tube - Google Patents

Shadow mask mounted in glass envelope of color tv picture tube Download PDF

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Publication number
US3484638A
US3484638A US741362A US3484638DA US3484638A US 3484638 A US3484638 A US 3484638A US 741362 A US741362 A US 741362A US 3484638D A US3484638D A US 3484638DA US 3484638 A US3484638 A US 3484638A
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US
United States
Prior art keywords
shadow mask
picture tube
tube
mask
face 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
Application number
US741362A
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English (en)
Inventor
Norman B Mears
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.)
Buckbee Mears Co
Original Assignee
Buckbee Mears Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Buckbee Mears Co filed Critical Buckbee Mears Co
Application granted granted Critical
Publication of US3484638A publication Critical patent/US3484638A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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

Definitions

  • This invention is directed toward use specifically in the construction of colored TV picture tubes containing shadow masks.
  • Shadow masks are made out of flat sheets of thin metal, such as stainless steel, containing a translucent area defined by a multitude of tiny, closely spaced apertures surrounded or enclosed by an imperforate marginal area.
  • the translucent area is ordinarily bowed out or made somewhat concave to conform to the partial spherical shape of the front viewing face of the picture tube enevlope.
  • the mask was mounted on a fairly heavy mounting ring which, in turn, was fastened to the inside of the picture tube bulb by suitable spring-like attachments.
  • the shadow mask not only serves the normal operation function in the picture tube of ensuring that the electron beams strike the proper dots of phosphor inside the front face of the tube, but it is also used during the assembly of the picture when the phosphor dot pattern is being formed.
  • the shadow mask is mounted in place temporarily and removed three times while the three sets of colored phosphor dots are being formed.
  • the picture tube comprises the usual glass front piece 3,484,638 Patented Dec. 16, 1969 or face plate containing the viewing face, and a back piece which when attached to the face plate, closes up the tube and holds the electron guns, etc. These two pieces are joined together in the usual manner after the phosphor dots have been formed and after the shadow mask has been mounted to the face plate.
  • the shadow mask is constructed with the usual translucent area surrounded by an imperforate section and shaped to conform to the contour of the viewing face of the picture tube. However, the outer edge of the mask is bent forward to form a skirt which engages a groove in the rear edge of the front section of the glass envelope which holds the mask in place but makes it easy to remove while the phosphor dots are being formed.
  • the back section is welded to the edge of the face plate section and holds the mask is held securely completely around its outer edge so that any temperature change-s which might tend to expand or contract the metal mask will now only make it flex forward or rearward with respect to the face of the tube. This would have little or no effect on the quality, brightness or brilliance of the picture being presented on the front face of the picture tube.
  • FIG. 1 is a rear view of a shadow mask constructed according to the teachings of this invention.
  • FIG. 2 is a rear view of the glass face plate of a picture tube in which the shadow mask would be mounted.
  • FIG. 3 is a sectional view showing the shadow mask mounted in the pitcure tube face plate.
  • the shadow mask 10 sometimes referred to as an aper ture mask, for color TV picture tubes contains a conventional translucent area 11 formed by a myriad of tiny, dot-like apertures which are usually etched through a sheet of metal such as stainless steel. Ordinarily the shadow mask is circular or rectangular depending on the type of tube that it is used in. Electron beams pass through the openings in the translucent area when traveling toward the prosphor particles on the inside of the viewing face of the tube from electron guns usually located at the rear of the tube. The phosphor particles, not shown, are located on the inside surface of the face plate portion 12 of the picture tube. As illustrated most clearly in FIG.
  • the shadow mask 10 has an imperforate marginal area 13 surrounding the translucent area 11.
  • a portion of this imperforate section 13 may be a smooth continuity of the concavity of the translucent area but at a suitable dimension, compatible with the size of the glass face plate 12, it is bent outward and then forward to form a skirt or flange 14 extending completely around the periphery of the shadow mask.
  • the rear edge 15 of glass face plate 12 contains a continuous groove or slot 16 suitabley dimensioned so that the skirt 14 on the shadow mask 10 will set snugly in the groove.
  • the shadow mask 10 can be temporarily mounted on the glass face plate 12 in this manner so that a set of phosphor dots can be photoprinted or otherwise appropriately formed in some acceptable manner through the translucent area 11.
  • the mask can be slipped out of the essing is necessary to form the dots. These steps can be followed a number of times until all of the sets of dots are appropriately formed.
  • the ease with which the mask can be attached and removed and the corresponding savings in time than becomes quite apparent, Of substantial significance is that each time the mask 10 is removed and then replaced, it will be repositioned at virtually the identical location as before so that the phosphor dots are in exact alignment with their corresponding openings in the translucent area of the shadow mask.
  • the mask 10 is inserted in groove 16 and the funnel-shaped rearmost portion of the glass tube envelope 17 is then brough into contact with the rear edge of the face plate 12 and Welded thereto in the usual fashion. This closes up the tube envelope and holds the shadow mask 10 securely in position within the groove 16. With the shadow mask 10 held in this fashion, any temperature variations during normal use which might tend to cause the metal mask to expand or contact will only make the translucent area 11 move forward or backward slightly with respect to the face plate 12 and will not cause any of the apertures from being laterally displaced with respect to their corresponding phosphor dots on the face plate. This eliminates one of the reasons for changes in the picture appearing on the viewing face during normal use of the TV set which has been a considerable concern to the industry.
  • the back portion 17 of the glass tube envelope which extends rearward from edge 15 of the face plate 12 is ordinarily funnel-shaped and contains the electron guns, not shown, which provide the electron beams.
  • the manner or process by which the two glass sections are welded together is of no particular concern in the instant invention and is well known to those of ordinary skill in the tube fabrication field.
  • a shadow mask comprising: a thin metal sheet having a translucent area de fined by a myriad of closely spaced miniature apertures through which electron beams pass when traveling toward the viewing face of the tube, said translucent area being enclosed by an imperforate rim section and being formed concave to conform generally to the partial spherical contour of the inner face of the tube; said rim section being bent forward to terminate with a forward extending flange continuously around the mask for nestling snugly in a continuous groove in the back edge of the picture tube face plate.
  • a glass envelope comprising a frontmost face plate portion in partial spherical contour terminating in a rearward facing enclosing edge which contains a continuous groove, and a rearmost portion extending rearward from said edge of the face plate portion;
  • a shadow mask comprising a thin metal sheet having a translucent area defined by a myriad of closely spaced miniature apertures through which electron beams pass when traveling from electron guns located at the rear of the tube to the viewing face in the face plate of the tube, said translucent area being formed concave to conform to the contour of the face plate, and an imperforate rim section around the translucent area extending outward to the glass envelope and being bent forward to form a flange for nestling snugly in the groove in the rear edge of the face plate portion of the glass envelope;

Landscapes

  • Electrodes For Cathode-Ray Tubes (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
US741362A 1968-07-01 1968-07-01 Shadow mask mounted in glass envelope of color tv picture tube Expired - Lifetime US3484638A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US74136268A 1968-07-01 1968-07-01

Publications (1)

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US3484638A true US3484638A (en) 1969-12-16

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ID=24980411

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Application Number Title Priority Date Filing Date
US741362A Expired - Lifetime US3484638A (en) 1968-07-01 1968-07-01 Shadow mask mounted in glass envelope of color tv picture tube

Country Status (5)

Country Link
US (1) US3484638A (enrdf_load_stackoverflow)
DE (1) DE1906828A1 (enrdf_load_stackoverflow)
FR (1) FR2012037A1 (enrdf_load_stackoverflow)
GB (1) GB1232911A (enrdf_load_stackoverflow)
NL (1) NL6909393A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3622297A (en) * 1970-03-13 1971-11-23 Stromberg Datagraphix Inc Method of fusion sealing wire gird in tube
US3873874A (en) * 1974-02-20 1975-03-25 Gte Sylvania Inc Shield attached by sealing to panel sidewall of cathode ray tube

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3116499B1 (fr) 2020-11-24 2022-10-07 Psa Automobiles Sa Procede de securisation d’une batterie.

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2827584A (en) * 1953-07-09 1958-03-18 Owens Illinois Glass Co Television picture tubes

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2827584A (en) * 1953-07-09 1958-03-18 Owens Illinois Glass Co Television picture tubes

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3622297A (en) * 1970-03-13 1971-11-23 Stromberg Datagraphix Inc Method of fusion sealing wire gird in tube
US3873874A (en) * 1974-02-20 1975-03-25 Gte Sylvania Inc Shield attached by sealing to panel sidewall of cathode ray tube

Also Published As

Publication number Publication date
NL6909393A (enrdf_load_stackoverflow) 1970-01-05
GB1232911A (enrdf_load_stackoverflow) 1971-05-26
DE1906828A1 (de) 1970-04-16
FR2012037A1 (enrdf_load_stackoverflow) 1970-03-13

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