US3782253A - Color television picture tube screening method - Google Patents

Color television picture tube screening method Download PDF

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Publication number
US3782253A
US3782253A US00356455A US3782253DA US3782253A US 3782253 A US3782253 A US 3782253A US 00356455 A US00356455 A US 00356455A US 3782253D A US3782253D A US 3782253DA US 3782253 A US3782253 A US 3782253A
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United States
Prior art keywords
lens
discontinuities
masked
masking
discontinuity
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Expired - Lifetime
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US00356455A
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English (en)
Inventor
Hekken F Van
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RCA Licensing Corp
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RCA Corp
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Assigned to RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE reassignment RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: RCA CORPORATION, A CORP. OF DE
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/20—Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel
    • H01J9/22—Applying luminescent coatings
    • H01J9/227—Applying luminescent coatings with luminescent material discontinuously arranged, e.g. in dots or lines
    • H01J9/2271—Applying luminescent coatings with luminescent material discontinuously arranged, e.g. in dots or lines by photographic processes
    • H01J9/2272—Devices for carrying out the processes, e.g. light houses
    • H01J9/2273—Auxiliary lenses and filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/02—Simple or compound lenses with non-spherical faces
    • G02B3/08—Simple or compound lenses with non-spherical faces with discontinuous faces, e.g. Fresnel lens
    • 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
    • H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
    • H01J29/18—Luminescent screens
    • H01J29/30—Luminescent screens with luminescent material discontinuously arranged, e.g. in dots, in lines
    • H01J29/32—Luminescent screens with luminescent material discontinuously arranged, e.g. in dots, in lines with adjacent dots or lines of different luminescent material, e.g. for colour television
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/20—Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel

Definitions

  • an ef- 95/1R y of elements are I G031, 27/00 masked.
  • the masked lens is displaced in a linear di- 95 rection diagonal to the directions of the discontinuities during exposure of a picture tube screen.
  • the diagonal corners of the mask pattern can be filled in to provide uniform exposure over the screen.
  • cathode-ray tubes have mosaic screens or targets of different light emitting or absorbing material.
  • certain types of color television picture tubes usually include a screen comprising arrays of red, green, and blue emitting phosphor lines or dots, electron gun means for exciting the screen, and a color selection electrode e.g., an apertured sheet metal mask or a wire grill, interposed between the gun means and the screen.
  • a color selection electrode e.g., an apertured sheet metal mask or a wire grill
  • the inner surface of the faceplate is coated with a mixture of phosphor particles adapted to emit light of one of the three colors (e.g., green), and a photosensitive binder.
  • the light source is sequentially placed in a fixed relationship with each center of deflection of each of the electron beams which later will excite the screen.
  • these deflection centers are not similarly fixed in position but rather vary in position during operation of the tube.
  • One such variation is a shift toward the screen as theangle of deflection increases. This shift of the deflection center'parallel to the tube axis causes a radial misregister of the electron impingement spots on the screen with respect to their corresponding phosphor dots established using a fixed light source.
  • correcting lenses located between the light source and the tube screen which provide appropriate deflection of the light rays so as to locate the position of the phosphor dots at the expected landing positions on the screen of the electron beams.
  • the design of correcting lenses for use in fabricating color television picture tubes has been described by Epstein et al in U. S. Pat. Nos. 2,817,276 and 2,885,935, by Ramberg in U. S. Pat. No. 3,279,340 and more recently by Yamazaki et al. in U. S. Pat. No.
  • the present invention provides an improvement in a method of screening a color television picture tube.
  • the basic method includes exposing a photosensitive material on a support with light emitted from a light source and passed through a lens having discontinuities on an effective surface thereof.
  • the improvement comprises masking the discontinuities and changing the relative position between the masked lens and the support in a linear direction diagonal to the directions of the discontinuities during exposure of the photosensitive material.
  • FIG. I is a partial plan view of a correcting lens having orthogonal discontinuities thereon;
  • FIG. 2 is a cross-sectional side view taken on line 2-2 of FIG. 1;
  • FIG. 3 is a partial plan view of a masked correcting lens
  • FIG. 4 is a cross-sectional side view taken on line 4-4 of FIG. 3;
  • FIG. 5 is a cross-sectional side view of another masked correcting lens
  • FIG. 6 is a partial plan view of yet another masked correcting lens
  • FIG. 7 is a partial plan view of a masked correcting lens having rectangular elements.
  • FIG. 8 is a partial plan view of a masked correcting lens having hexagonal elements.
  • FIGS. l and 2 depict a top plan view and a crosssectional side view, respectively, of a correction lens 10 for use in lighthouse screening of a color television picture tube.
  • the lens has one surface 12 divided into a plurality of square elements 14.
  • Each of these elements 14 provides a separate optical correction for screening a similarly shaped corresponding area of the tube screen. Because of this separate correction for each element, the slopes of adjacent elements may vary so that the interfaces between adjacent elements form discontinuities 16 and 18 in the lens surface 12. Since the elements 14 are square shaped and are aligned in rows in two directions, the discontinuities 16 and 18 are orthogonal to each other.
  • the lens 10 In using the lens 10 to screen a picture tube, the lens is placed between a light source and a tube faceplate that has been coated with a photosensitive material. Light is projected through the lens wherein its path is changed to the path an electron beam will take as it strikes the screen. However, a light striking the discontinuities l6 and 18 is deflected or scattered, thereby causing ambient defects on the screen.
  • the discontinuities l6 and 18 are masked, as shown in FIG. 3 by a pattern of opaque stripes 20.
  • Such masking can be accomplished in several ways, two of which are shown in FIGS. 4 and 5.
  • the first masking scheme is incorporated in a lens package 26 depicted in FIG. 4.
  • the package 26 includes the lens and a glass substrate 28 peripherally attached to the lens 10.
  • the pattern of opaque stripes is attached to a surface of the glass substrate 28 so that each stripe of the pattern is directly opposite a surface discontinuity 16 of the lens 12.
  • opaque strips 20 are applied directly to the lens 10 over each of the discontinuities 16.
  • other masking schemes may also be used for different lens constructions.
  • the velocity representation of such oscillation should approach a step function in contrast to the sinusoidal function of a free oscillator.
  • step function is necessary to provide minimum dwell at the reversal points of the oscillation to ensure that the screen is evenly exposed and that the mask pattern does not appear on the completed screen.
  • the difference in exposure between one and two stripe widths is essentially negligable.
  • stripe width becomes large enough so that a diagonally overexposed pattern becomes apparent
  • the diagonal corners in the direction of displacement can be filled in with fillets 30 as shown in FIG. 6, of the same opaque material as the stripes 20.
  • the diagonal distance across the mask between sides of the fillets should be equal to twice the diagonal width of a stripe so that the shadowing along each of the lines 22 and 24 are equivalent. Utilization of the fillets therefore permits even exposure over the entire screen when the masked lens is oscillated along line AA.
  • the present invention can also be applied to lenses with discontinuous surfaces other than square shaped elements.
  • the invention can also be applied to rectangularly shaped elements 38 and 40 as shown in the masked lens 32 in FIG. 7.
  • the discontinuities 34 are masked by aligned opaque stripes 36.
  • two corners of each lens element are masked by nonisosceles fillets 42 and-44 and the lens position is changed in a diagonal direction as indicated by lines 46 and 48 which are diagonals of elements 38 and 40, respectively.
  • FIG. 8 shows a masked lens 50 having hexagonal shaped elements 52 and 54.
  • the discontinuities e.g., 56, 58 and 60
  • the opaque stripes e.g., 62,64 and 66, respectively.
  • the opaque stripes 62 extending in one direction are made wider than the other stripes 64 and 66. Therefore, when the lens 50 is moved perpendicular to the wide stripes 62 a distance equal to the distance between element center points or between parallel discontinuities, all parts of the screen will receive uniform exposure.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
  • Microscoopes, Condenser (AREA)
US00356455A 1973-05-02 1973-05-02 Color television picture tube screening method Expired - Lifetime US3782253A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US35645573A 1973-05-02 1973-05-02

Publications (1)

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US3782253A true US3782253A (en) 1974-01-01

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ID=23401486

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Application Number Title Priority Date Filing Date
US00356455A Expired - Lifetime US3782253A (en) 1973-05-02 1973-05-02 Color television picture tube screening method

Country Status (9)

Country Link
US (1) US3782253A (enrdf_load_stackoverflow)
JP (1) JPS5339305B2 (enrdf_load_stackoverflow)
BE (1) BE814361A (enrdf_load_stackoverflow)
BR (1) BR7403503D0 (enrdf_load_stackoverflow)
CA (1) CA1031208A (enrdf_load_stackoverflow)
FR (1) FR2228291B1 (enrdf_load_stackoverflow)
GB (1) GB1473388A (enrdf_load_stackoverflow)
IT (1) IT1010900B (enrdf_load_stackoverflow)
NL (1) NL7405484A (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4521501A (en) * 1983-07-14 1985-06-04 Rca Corporation Method for reducing degradation of an optical image in an exposure lighthouse

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3279340A (en) * 1964-03-19 1966-10-18 Rca Corp Art of making color-phosphor mosaic screens
US3628850A (en) * 1970-02-24 1971-12-21 Hitachi Ltd Correcting lens
US3738234A (en) * 1971-05-08 1973-06-12 Philips Corp Exposure device for manufacturing a display screen of a color television picture tube

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4721552U (enrdf_load_stackoverflow) * 1971-03-05 1972-11-10

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3279340A (en) * 1964-03-19 1966-10-18 Rca Corp Art of making color-phosphor mosaic screens
US3628850A (en) * 1970-02-24 1971-12-21 Hitachi Ltd Correcting lens
US3738234A (en) * 1971-05-08 1973-06-12 Philips Corp Exposure device for manufacturing a display screen of a color television picture tube

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4521501A (en) * 1983-07-14 1985-06-04 Rca Corporation Method for reducing degradation of an optical image in an exposure lighthouse

Also Published As

Publication number Publication date
GB1473388A (en) 1977-05-11
BE814361A (fr) 1974-08-16
JPS5339305B2 (enrdf_load_stackoverflow) 1978-10-20
DE2421253A1 (de) 1974-11-14
DE2421253B2 (de) 1977-06-08
CA1031208A (en) 1978-05-16
BR7403503D0 (pt) 1974-11-19
JPS5017169A (enrdf_load_stackoverflow) 1975-02-22
FR2228291A1 (enrdf_load_stackoverflow) 1974-11-29
FR2228291B1 (enrdf_load_stackoverflow) 1976-12-17
NL7405484A (enrdf_load_stackoverflow) 1974-11-05
AU6845974A (en) 1975-11-06
IT1010900B (it) 1977-01-20

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AS Assignment

Owner name: RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, P

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:RCA CORPORATION, A CORP. OF DE;REEL/FRAME:004993/0131

Effective date: 19871208