US3736848A - Method of preparing the screen of a colour television picture tube and device performing the method - Google Patents

Method of preparing the screen of a colour television picture tube and device performing the method Download PDF

Info

Publication number
US3736848A
US3736848A US00189723A US3736848DA US3736848A US 3736848 A US3736848 A US 3736848A US 00189723 A US00189723 A US 00189723A US 3736848D A US3736848D A US 3736848DA US 3736848 A US3736848 A US 3736848A
Authority
US
United States
Prior art keywords
light
shadow mask
prism
screen
hole
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
US00189723A
Other languages
English (en)
Inventor
A Tsuneta
M Ikegaki
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.)
Toshiba Corp
Original Assignee
Tokyo Shibaura Electric Co Ltd
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 Tokyo Shibaura Electric Co Ltd filed Critical Tokyo Shibaura Electric Co Ltd
Application granted granted Critical
Publication of US3736848A publication Critical patent/US3736848A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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

Definitions

  • the screen of such type of picture tube consists of a black lightabsorbing layer such as that of graphite, a matrix layer perforated with matrix holes corresponding to red, blue and green colours and fluorescent dots embedded in said holes so as to produce red, blue and green lights.
  • a shadow mask About mm apart from the screen is disposed a shadow mask. It is considered necessary for the shadow mask holes to have a larger diameter than the fluorescent dots in order effectively to expose said dots to light.
  • the matrix holes should be formed with a smaller diameter than the shadow mask holes.
  • the shadow mask holes are first formed with substantially the same diameter as the matrix holes which should be finally obtained. After light is projected on the screen through the shadow mask holes, the shadow mask is etched again to broaden its holes.
  • the shadow mask holes are so formed from the outset as to have a larger diameter than the matrix holes which should be finally obtained. Under such condition, there are baked to the screen a large number of minute areas corresponding to the matrix holes.
  • the method of (1) there has to be additionally applied a complicated step of etching the shadow mask a second time, said etching causing the shadow mask to be reduced in thickness and consequently in mechanical strength.
  • the latter method of (2) is preferable, the conventional procedure associated therewith had serious drawbacks as described later. Eventually, therefore, the method of (1) has generally been adapted.
  • FIG. 1 is a schematic diagram of a device for projecting light on the screen, illustrating the method of(2) as conventionally practised;
  • FIGS. 2A and 2B are curve diagrams showing the dis tribution of light quantity on the screen
  • F10. 3 is a schematic diagram of a device for projecting tight on the screen according to an embodiment of this invention.
  • HG. 4A is a plan view of a prism-revolving mechanisrn to be used in FIG. 3;
  • FIG. 4B is a sectional view on line lV-IV of FIG. 4A as viewed in the direction of the arrows;
  • FIG. 5 is a sectional view of a modified prism device of this invention.
  • Said device includes an extremely minute source of light 11 about l.O to 0.3 mm in diameter. While said source oflight I1 is rotated with a rotation diameter of about I to 3 mm along a locus 12, there is projected light through the holes of a shadow mask 13 on a layer 15 made of photosensitive polyvinyl alcohol resin (PVA) coated on a panelld constituting a screen.
  • PVA photosensitive polyvinyl alcohol resin
  • the region where the integrated quantity of light becomes uniform is always a smaller area than the holes of the shadow mask. Projection of light, therefore, on said region enables screen holes to be formed with a smaller diameter than shadow mask holes.
  • the curve 20 of FIG. 2B denotes the integrated quantity of light where, the light source 11 is fixed on a central line C (FIG. 1) of a hole of the shadow mask instead of being rotated.
  • a source of power Accordingly, a light source system of the aforementioned arrangement unavoidably becomes bulky, so that the conventional method of preparing a screen by rotating such a bulky light source system presents extreme difficulties in elevating the precision more than one-tenth with which the rotation diameter should be controlled. Since the tolerance to errors in the rotation diameter is of the order of one-handredth, the prior art method of preparing a screen based on the rotation of a light source failed to be put to practical application.
  • a method of preparing the screen ofcolour television picture tube by photographic printing which consists in providing an optical system between a screen being prepared and a light source so fixed as to face said screen, causing the optical system to be rotated in order to form on said screen light-baked portions hav ing a smaller area than the light-permeable shadow mask holes and a device for performing the method.
  • the beam of electrons has a larger diameter than the fluorescent dots, and the area occupied by the matrix section normally accounts for 40 to 50 per cent of the effective area of the screen. Accordingly, this type of picture tube prevents the intrusion of light reflected from the outside, suppresses the appearance of scattered light and reproduces colour television images in distinct contrast, thus attracting great attention in recent years.
  • a layer of PVA is coated on a screen panel.
  • the lighbexposed screen panel is developed to wash away the PVA coated on the other regions of said panel than those which were exposed to light through the shadow mask holes.
  • This invention is intended to provide a method of preparing a screen by improving a device for projecting light thereon.
  • FlG. 3 The same parts ofFlG. 3 as those of FlG. l are denoted by the same numerals and description thereof is omitted.
  • a device with a round periphery for causing a prism 22 to revolve horizontally in a prescribed direction with said spot light source 21 fixed.
  • the prism 22 tapered at an angle 8 is so disposed as to cause the axis thereof to be aligned with the center line C ofthe shadow mask hole.
  • the af rementioned correction lens is not indicated.
  • Light projected from point 0 of the spot light source 21 is deflected by the prism 22 and brought to the PVA layer 15 deposited on the screen panel 14 through such a route as would appear if it was emitted straight from point 0'.
  • point 0' is revolved along a locus 24 to provide light-exposed portions having a smaller diameter than the shadow mask holes by the same principle as that by which there is revolved the light source of FIG. 1, thus enabling PVA dots smaller than the shadow mask holes to be baked to the screen.
  • the diameter of a circular locus along which point 0' rotates may be defined as desired by selecting the angle 0 at which the prism used is tapered.
  • the angle of incidence of light to the plane of the prism 22 and in consequence the smoothness of its surface have a great bearing. How ever, said smoothness can be easily attained with high precision.
  • the angle of incidence of light to the plane of the prism 22 does not vary with the displacement of said prism 22 in a direction perpendicular to the axis of the picture tube, namely, the center line C (the direction indicated by A-A in H6. 3). Therefore, the displacement of the image 0' of the light source caused by such lateral shift of the prism 22 is so extremely small that it can be considered negligible.
  • FIGS. 4A and 4B One embodiment of a device 23 for causing the prism 22 to rotate consists of the type illustrated in FIGS. 4A and 4B.
  • the prism 22 is supported on an annular metal frame 25 which is made to rotate by rollers 26 abutting against its periphery 250, thus leading to the rotation of the prism 22.
  • that side 25b of the prism-supporting metal frame 25 which faces the light source 21 is machined to attain the highest possible precision of smoothness and the base plate 28 of said supporting metal frame 25 is fitted with bearing 27 in at least three places. That side of the base plate 28 which faces the prism 22 is hollowed out in the annular form to conduct light to the prism 22.
  • the prism 22 may be caused to be revolved by using a fluid pressure.
  • the device 23 of this invention arranged as described above for revolution ofthe prism 22 has only to be designed for said revolution, promincntly simplifying the arrangement. Accordingly, the method of this invention enabes errors in the diameter of a circular locus along which the image of the light source is shifted to be reduced to below one hundredth. Therefore, this invention has rendered the prior art screen-manufacturing method based on the rotation of a light source fully available for practical application simply by causing the image of a light source to be rotated with the light source itself fixed.
  • FIG. 5 illustrating a device according to another embodiment of this invention for causing a prism to revolve itself
  • two prism means 30 and 31 each consisting of a prism 22 and the corresponding annular metal frame 25.
  • Variation of the angle at which both prisms are combined enables the displacement of the image 0 of a light source from said source 0, that is, the radius of a circular locus along which said image 0' is rotated to be easily changed.
  • the prior art screen-preparing method based on the rotation of a light source, it was difficult to design a rotation device so as to cause the light source to travel along a circular locus whose diameter could be made variable.
  • the embodiment of H6. 5 enables the radius of a circular locus along which the image of a light source travels to be easily changed by varying the angle at which there are combined two prism means 3% and 31.
  • the method of this invention consists in using a spot light source and optical system, for example, a prism to produce an image of said light source at a point displaced a prescribed distance therefrom, causing the optical system to revolve, and projecting light on a screen while rotating said image, thereby baking to the screen fluorescent dots having a smaller diameter than the shadow mask holes.
  • a spot light source and optical system for example, a prism to produce an image of said light source at a point displaced a prescribed distance therefrom, causing the optical system to revolve, and projecting light on a screen while rotating said image, thereby baking to the screen fluorescent dots having a smaller diameter than the shadow mask holes.
  • a device for preparing the screen of a color television picture tube provided with fluorescent dots hav ing a smaller area than the area of holes of the shadow mask of the tube provided with an optical system for projecting light from a spot light source onto a panel bearing a photosensitive layer in such manner that an integrated quantity of light projected on the photosensitive layer produces a developable image of a dot having an area smaller than the hole of the shadow mask, the improvement which comprises:
  • a stationary spot light source for projecting light through a hole of the shadow mask onto the panel on which there is to be formed the screen of the picture tube
  • optical system comprises a second tapered prism adjacent said tapered prism and means to adjust the angle between said prisms.
  • said means to rotate said tapered prism comprises a metal frame for sup porting at least one prism, a plurality of rollers abutting against the perifery of said frame to impart rotating motion to the prism, a base plate upon which said rollers are fitted, said plate having an opening therethrough at the portion of the plate that faces said prism and bearings carried by said base plate upon which the prism is supported for rotation.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
US00189723A 1970-10-20 1971-10-15 Method of preparing the screen of a colour television picture tube and device performing the method Expired - Lifetime US3736848A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9162370 1970-10-20

Publications (1)

Publication Number Publication Date
US3736848A true US3736848A (en) 1973-06-05

Family

ID=14031678

Family Applications (1)

Application Number Title Priority Date Filing Date
US00189723A Expired - Lifetime US3736848A (en) 1970-10-20 1971-10-15 Method of preparing the screen of a colour television picture tube and device performing the method

Country Status (4)

Country Link
US (1) US3736848A (OSRAM)
DE (1) DE2152304A1 (OSRAM)
FR (1) FR2110028A5 (OSRAM)
GB (1) GB1372530A (OSRAM)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3810196A (en) * 1971-05-14 1974-05-07 Philips Corp Exposure device for manufacturing a display screen of a colour television picture tube, comprising a rotating lens
US3883880A (en) * 1972-12-25 1975-05-13 Hitachi Ltd Exposure apparatus for manufacturing fluorescent screens of colour picture tubes
US3888673A (en) * 1972-08-21 1975-06-10 Tokyo Shibaura Electric Co Method and apparatus for making electroluminescent screens for color cathode ray tubes
US3890151A (en) * 1972-08-07 1975-06-17 Tokyo Shibaura Electric Co Method for making electroluminescent screens for color cathode-ray tubes of continuous phosphor stripes
US3971043A (en) * 1972-08-21 1976-07-20 Tokyo Shibaura Electric Co., Ltd. Apparatus for making electroluminescent screens for color cathode ray tubes
US3993487A (en) * 1969-01-03 1976-11-23 Matsushita Electronics Corporation Method for manufacture of color television picture tubes using rotating light source
US4013467A (en) * 1971-06-18 1977-03-22 Matsushita Electronics Corporation Method of manufacturing color picture tubes using rotating light attenuator
US4059834A (en) * 1974-03-13 1977-11-22 Matsushita Electronics Corporation Light exposing apparatus for forming a phosphor screen of a cathode ray tube
US4118109A (en) * 1976-01-31 1978-10-03 Ferranti Limited Optical apparatus for controlling the direction of a beam of optical radiation
US4515447A (en) * 1982-04-17 1985-05-07 Carl-Zeiss-Stiftung Optical adjustment device
US4953150A (en) * 1981-11-09 1990-08-28 Canon Kabushiki Kaisha Optical recording apparatus having improved erasing capability
US5202868A (en) * 1989-05-24 1993-04-13 Kyocera Corporation Method of displacing a beam converging position and apparatus thereof
US5671460A (en) * 1994-03-31 1997-09-23 Kabushiki Kaisha Toshiba Exposing apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3358175A (en) * 1962-07-06 1967-12-12 Rca Corp Cathode ray tube with mosaic type phosphor screen

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3358175A (en) * 1962-07-06 1967-12-12 Rca Corp Cathode ray tube with mosaic type phosphor screen

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993487A (en) * 1969-01-03 1976-11-23 Matsushita Electronics Corporation Method for manufacture of color television picture tubes using rotating light source
US3810196A (en) * 1971-05-14 1974-05-07 Philips Corp Exposure device for manufacturing a display screen of a colour television picture tube, comprising a rotating lens
US4013467A (en) * 1971-06-18 1977-03-22 Matsushita Electronics Corporation Method of manufacturing color picture tubes using rotating light attenuator
US3890151A (en) * 1972-08-07 1975-06-17 Tokyo Shibaura Electric Co Method for making electroluminescent screens for color cathode-ray tubes of continuous phosphor stripes
US3971043A (en) * 1972-08-21 1976-07-20 Tokyo Shibaura Electric Co., Ltd. Apparatus for making electroluminescent screens for color cathode ray tubes
US3888673A (en) * 1972-08-21 1975-06-10 Tokyo Shibaura Electric Co Method and apparatus for making electroluminescent screens for color cathode ray tubes
US3883880A (en) * 1972-12-25 1975-05-13 Hitachi Ltd Exposure apparatus for manufacturing fluorescent screens of colour picture tubes
US4059834A (en) * 1974-03-13 1977-11-22 Matsushita Electronics Corporation Light exposing apparatus for forming a phosphor screen of a cathode ray tube
US4118109A (en) * 1976-01-31 1978-10-03 Ferranti Limited Optical apparatus for controlling the direction of a beam of optical radiation
US4953150A (en) * 1981-11-09 1990-08-28 Canon Kabushiki Kaisha Optical recording apparatus having improved erasing capability
US4515447A (en) * 1982-04-17 1985-05-07 Carl-Zeiss-Stiftung Optical adjustment device
US5202868A (en) * 1989-05-24 1993-04-13 Kyocera Corporation Method of displacing a beam converging position and apparatus thereof
US5671460A (en) * 1994-03-31 1997-09-23 Kabushiki Kaisha Toshiba Exposing apparatus

Also Published As

Publication number Publication date
GB1372530A (en) 1974-10-30
FR2110028A5 (OSRAM) 1972-05-26
DE2152304A1 (de) 1972-07-06

Similar Documents

Publication Publication Date Title
US3736848A (en) Method of preparing the screen of a colour television picture tube and device performing the method
US2947899A (en) Color image reproducers
US3906515A (en) Apparatus and method of manufacturing color picture tubes
US3211067A (en) Method of exposing a multi-color target structure
US3993487A (en) Method for manufacture of color television picture tubes using rotating light source
KR0137900B1 (ko) 칼라 수상관의 형광면의 형성방법 및 노광장치
US4013467A (en) Method of manufacturing color picture tubes using rotating light attenuator
US3767395A (en) Multiple exposure color tube screening
US3043975A (en) Image display device
US3971043A (en) Apparatus for making electroluminescent screens for color cathode ray tubes
KR0150393B1 (ko) 노광장치
US2989398A (en) Method of manufacturing electrical apparatus
US4111694A (en) Method for manufacturing the picture display screen of a color television tube using a cylinder lens
US4050080A (en) CRT screen exposure device utilizing improved light means
US3738233A (en) Camera process for color tube screen printing
US3579335A (en) Method for manufacturing color television receiver tubes
US3922689A (en) Optical system for a lighthouse enclosure
US4020494A (en) CRT screen exposure device having improved optical alignment
US3504599A (en) Optical system for use in making color-phosphor mosaic screens
JPS6135652B2 (OSRAM)
JPS63279538A (ja) カラ−陰極線管の蛍光面作成用露光装置
US4034382A (en) Apparatus for forming a color television picture tube screen
KR200155319Y1 (ko) 칼라 음극선관 제작용 노광장치
JPS6217925A (ja) 露光方法
JPS6041819B2 (ja) カラ−受像管螢光面の製造方法