US2305855A - Television apparatus - Google Patents
Television apparatus Download PDFInfo
- Publication number
- US2305855A US2305855A US404826A US40482641A US2305855A US 2305855 A US2305855 A US 2305855A US 404826 A US404826 A US 404826A US 40482641 A US40482641 A US 40482641A US 2305855 A US2305855 A US 2305855A
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- US
- United States
- Prior art keywords
- screen
- tube
- section
- projection
- curvature
- 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
Links
- 239000002184 metal Substances 0.000 description 18
- 239000011521 glass Substances 0.000 description 16
- 239000000463 material Substances 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 7
- 238000000576 coating method Methods 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 6
- 230000004075 alteration Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000011324 bead Substances 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- 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
- H01J29/86—Vessels; Containers; Vacuum locks
- H01J29/89—Optical or photographic arrangements structurally combined or co-operating with the vessel
- H01J29/894—Arrangements combined with the vessel for the purpose of image projection on a screen
-
- 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
- H01J29/86—Vessels; Containers; Vacuum locks
- H01J29/861—Vessels or containers characterised by the form or the structure thereof
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/74—Projection arrangements for image reproduction, e.g. using eidophor
Definitions
- the cathode ray projection tube is best operated at a high voltage and the fluorescent screen may become too hot for maximum light output and, also, for
- An object of the present invention is to provide an improved television projection system having relatively high light output.
- a further object of the invention is to provide an improved television projection system in which the fluorescent screen of the projection tube will remain reasonably cool during operation.
- a further object of the invention is to provide an improved television projection system in which the projected light is obtained from the same side of the fluorescent screen thatis being scanned.
- a still further object of the invention is to provide an improved cathode ray projection tube.
- the envelope of a cathode ray projection tube comprises a metalv section which faces the electron gun of the tube and which is coated with a suitable luminescent or fluorescent material.
- the metal section will conduct heat away from the screen material much more rapidly than will the glass supporting area of the earlier tubes.
- Our improved tube is also so designed that it does not require keystone correction even though the projected light is coming from the same side of the screen that is being scanned, this being the side that emits the most light.
- Such a design is obtained by properly combining our projection tube with a suitable projection optical system.
- FIG. 1 shows one embodiment of the invention comprising our improved projection tube in combination with a reflective optical system
- Fig. 2 shows in cross section, and on a larger scale, the projection tube shown in Fig. 1, and
- Fig. 3 isa view illustrating another method of constructing a projection tube in accordancewith the invention.
- the projection system comprises a reflective optical system consisting of a spherical mirror It and a spherical aberration correcting plate II, this type of optical system being described in the above-identified Landis patent.
- the cathode ray tube comprises a highly evacuated envelope consisting of a glass section I: in which the electron gun is located, and a metal section l3 having a curvedsurface I 3' facing.
- the curved metal surface I3 is coated inside the tube with a suitable fluorescent material to form ascreen I6.
- a specifle structure is shown in Fig. 2, by way of example. It comprises an indirectly heated cathode 2
- the electrodes 23 and 24 are supported by means of glass beads 21.
- the electrode 26 is supported by means of a mica washer 23.
- This particular gun is designed to have no first anode current as described and claimed in application Serial I envelope by a conducting strip 33.
- may be supported on a re- I entrant portion added to the glass section of the envelope to prevent high voltage breakdown between the coating 3
- the glass face I2 preferably is substantially concentric with the spherical mirror, that is, its radius of curvature is R/2+d, where R is the radius of curvature of the mirror It and d is the radial distance between the screen It and the face l2.
- the tube end i3, and the screen I! thereon, have a spherical curvature with a radius of approximately R/2 where R is the radius of curvature of the spherical mirror III.
- This curvature of the screen II is required if the field of the projected image is to be flat, as it should be for projection on the usual projection screen.
- the screen I. can be cooled by blowing air against the tube end It or even by water cooling the end of the tube, if desired.
- Fig. 3 shows the screen end of a tube having an envelope which is made entirely of glass except for a comparatively small end section 36 of metal.
- a luminescent screen 31 On the inner surface of the curved area of section 36 there is a luminescent screen 31 corresponding to the screen It in Fig. 2.
- a cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there is a coating of luminescent material to form a screen, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, a portion of said glass section which surrounds said longitudinal axis forming a window through which light from said screen may leave the tube, said screen coated area of the metal section being convex as viewed from the inside of said tube.
- a cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there is a coating of luminescent material to form a screen on which a received picture may be reproduced, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, a
- a cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there is a coating of luminescent material to form a screen on which an image may be reproduced, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a a metal section, said metal section having an area on which there is a coating oi.
- luminescent material to form a screen on which a received picture may be reproduced
- an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, a portion of said glass section which surrounds said axis forming a window through which light from said screen may leave the tube, a spherical mirror positioned to project said reproduced picture upon a projection screen and a spherical aberration correcting plate positioned at least approximately at the center of curvature of said mirror to correct its spherical aberration, said screen coated area of the metal section being convex as viewed from the inside of said tube and having a radius of curvature which is at least approximately equal to one-half the radius of curvature of said mirror.
- a cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there-is a coating of luminescent material to form a screen on which a received picture may be reproduced, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, said glass section having a flange-like portion surrounding said axis and forming a window through which light from said screen may leave the tube, a spherical mirror positioned to project said reproduced picture upon a projection screen and a spherical aberration correcting plate positioned at least approximately at the center of curvature of said mirror to correct for its spherical aberration, said screen coated area of the I metal section being convex as viewed from the inside of said tube and having a radius of curvature which is at least approximately equal to one-half the radius of curvature of said mirror, and said flange-like portion being concave as viewed
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
- Transforming Electric Information Into Light Information (AREA)
Description
Dec. 22, 1942. p w EP$TE|N ETAL 2,305,855
TELEVISION APPARATUS Filed July 31, 1941 mmm Inventors David WEP'Si/ei/n/ loury G.MaLoff &- Hedericli HJVic LL r....'.'..d Dec. 22, 19 :2
'6 UNITED STATES PATENT. oer-ICE I j TELEVISION APPARATUS David W. Epstein, Merchantvlilc, Ioary G. Malofl, Slcklerville', and Frederick H. Nieoll, Merchantville, N. 1., assignors to Radio 00rporation of America, a corporation of Delaware Application July 31,1941, Serial No. mm
' Landis Patent No. 2,273,801. issued Feb. 17, 1942,
and entitled Television receiver. Even with an I optical system of this type, however, the cathode ray projection tube is best operated at a high voltage and the fluorescent screen may become too hot for maximum light output and, also, for
a reasonable life of the screen.
An object of the present invention is to provide an improved television projection system having relatively high light output.
A further object of the invention is to provide an improved television projection system in which the fluorescent screen of the projection tube will remain reasonably cool during operation. l
A further object of the invention is to provide an improved television projection system in which the projected light is obtained from the same side of the fluorescent screen thatis being scanned.
A still further object of the invention is to provide an improved cathode ray projection tube.
In practicing a preferred embodiment of the invention, the envelope of a cathode ray projection tube'comprises a metalv section which faces the electron gun of the tube and which is coated with a suitable luminescent or fluorescent material. The metal section will conduct heat away from the screen material much more rapidly than will the glass supporting area of the earlier tubes.
Our improved tube is also so designed that it does not require keystone correction even though the projected light is coming from the same side of the screen that is being scanned, this being the side that emits the most light. Such a design is obtained by properly combining our projection tube with a suitable projection optical system.
The invention will be better understood from with the accompanying drawing in which Fig. 1 shows one embodiment of the invention comprising our improved projection tube in combination with a reflective optical system,
the following description taken in connection Fig. 2 shows in cross section, and on a larger scale, the projection tube shown in Fig. 1, and
Fig. 3 isa view illustrating another method of constructing a projection tube in accordancewith the invention.
Referring to the embodiment shown-in Fig. 1, the projection system comprises a reflective optical system consisting of a spherical mirror It and a spherical aberration correcting plate II, this type of optical system being described in the above-identified Landis patent.
The cathode ray tube comprises a highly evacuated envelope consisting of a glass section I: in which the electron gun is located, and a metal section l3 having a curvedsurface I 3' facing.
the electron gun The glass and metal sections are sealed at the rim I.
As shown in Fig. 2, the curved metal surface I3 is coated inside the tube with a suitable fluorescent material to form ascreen I6.
While various electron gun structures may be utilized, a specifle structure is shown in Fig. 2, by way of example. It comprises an indirectly heated cathode 2|, a control grid 22, a screen grid 23, a first anode 24 and a second anode 26. The electrodes 23 and 24 are supported by means of glass beads 21. The electrode 26 is supported by means ofa mica washer 23. This particular gun is designed to have no first anode current as described and claimed in application Serial I envelope by a conducting strip 33.
If desired, the second anode 26 and the conductive coating 3| may be supported on a re- I entrant portion added to the glass section of the envelope to prevent high voltage breakdown between the coating 3| and the deflecting coils (not shown) as taught in application Serial No. 302,217, flled October 31, 1939, in the name of David W. pste It will be apparent that most of the light from a reproduced picture image on the screen l6 passes through the flange-like portion or face l2 of the glass section of the tube envelope (the narrow conducting strip 33 covering only a small area). Thus, theppath of the light rays is as indicated by the dotted line in Fig; 1. The glass face I2 preferably is substantially concentric with the spherical mirror, that is, its radius of curvature is R/2+d, where R is the radius of curvature of the mirror It and d is the radial distance between the screen It and the face l2.
The tube end i3, and the screen I! thereon, have a spherical curvature with a radius of approximately R/2 where R is the radius of curvature of the spherical mirror III. This curvature of the screen II is required if the field of the projected image is to be flat, as it should be for projection on the usual projection screen.
It will be apparent that the screen I. can be cooled by blowing air against the tube end It or even by water cooling the end of the tube, if desired.
Various modifications may be made in the construction of our improved cathode ray tube. For example, Fig. 3 shows the screen end of a tube having an envelope which is made entirely of glass except for a comparatively small end section 36 of metal. On the inner surface of the curved area of section 36 there is a luminescent screen 31 corresponding to the screen It in Fig. 2.
From the foregoing it will be understood that various other modifications may be made in our invention without departing from the spirit and scope thereof.
We claim as our invention:
1. A cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there is a coating of luminescent material to form a screen, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, a portion of said glass section which surrounds said longitudinal axis forming a window through which light from said screen may leave the tube, said screen coated area of the metal section being convex as viewed from the inside of said tube.
2. In combination, a cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there is a coating of luminescent material to form a screen on which a received picture may be reproduced, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, a
portion of said glass section which surrounds said longitudinal axis forming a window through which light from said screen may leave the tube, and an optical projection system positioned to project said reproduced picture upon a projection screen.
3. In combination, a cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there is a coating of luminescent material to form a screen on which an image may be reproduced, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a a metal section, said metal section having an area on which there is a coating oi. luminescent material to form a screen on which a received picture may be reproduced, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, a portion of said glass section which surrounds said axis forming a window through which light from said screen may leave the tube, a spherical mirror positioned to project said reproduced picture upon a projection screen and a spherical aberration correcting plate positioned at least approximately at the center of curvature of said mirror to correct its spherical aberration, said screen coated area of the metal section being convex as viewed from the inside of said tube and having a radius of curvature which is at least approximately equal to one-half the radius of curvature of said mirror.
5. In combination, a cathode ray tube having an envelope which comprises a glass section and a metal section, said metal section having an area on which there-is a coating of luminescent material to form a screen on which a received picture may be reproduced, an electron gun in said tube positioned on the longitudinal axis thereof and substantially normal to said screen to direct a scanning beam against said screen, said glass section having a flange-like portion surrounding said axis and forming a window through which light from said screen may leave the tube, a spherical mirror positioned to project said reproduced picture upon a projection screen and a spherical aberration correcting plate positioned at least approximately at the center of curvature of said mirror to correct for its spherical aberration, said screen coated area of the I metal section being convex as viewed from the inside of said tube and having a radius of curvature which is at least approximately equal to one-half the radius of curvature of said mirror, and said flange-like portion being concave as viewed from the inside of said tube and having a radius of curvature equal at least approximately to one-half the radius of curvature of said mirror plus the radial distance from said luminescent screen to said flange-like portion.
DAVID W. EPSTEIN. IOURY G. MALOFF. FREDERICK H. NICOLL.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US404826A US2305855A (en) | 1941-07-31 | 1941-07-31 | Television apparatus |
GB10640/42A GB559214A (en) | 1941-07-31 | 1942-07-30 | Improvements in television image projection systems and cathode ray tubes for use therein |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US404826A US2305855A (en) | 1941-07-31 | 1941-07-31 | Television apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
US2305855A true US2305855A (en) | 1942-12-22 |
Family
ID=23601216
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US404826A Expired - Lifetime US2305855A (en) | 1941-07-31 | 1941-07-31 | Television apparatus |
Country Status (2)
Country | Link |
---|---|
US (1) | US2305855A (en) |
GB (1) | GB559214A (en) |
Cited By (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2435316A (en) * | 1943-11-01 | 1948-02-03 | Farnsworth Res Corp | Optical focusing means for image translating devices |
US2440735A (en) * | 1943-06-05 | 1948-05-04 | Farnsworth Res Corp | Electrooptical device |
US2448476A (en) * | 1943-12-03 | 1948-08-31 | Rauland Corp | Cathode-ray projector tube |
US2449259A (en) * | 1941-07-01 | 1948-09-14 | Hartford Nat Bank & Trust Co | Schmidt type optical system with parallel plate refractive element |
US2453003A (en) * | 1946-03-07 | 1948-11-02 | Pye Ltd | Television projection tube |
US2458132A (en) * | 1945-06-19 | 1949-01-04 | Perkin Elmer Corp | Schmidt image former with spherical aberration corrector |
US2459637A (en) * | 1944-11-29 | 1949-01-18 | Motorola Inc | Cathode-ray image-translating device |
US2481615A (en) * | 1945-06-23 | 1949-09-13 | Philco Corp | Image projection optical system with cylindrical screen means |
US2482151A (en) * | 1944-08-18 | 1949-09-20 | Philips Lab Inc | Cathode-ray projection tube |
US2482566A (en) * | 1945-06-16 | 1949-09-20 | Philco Corp | Image-projection optical system with cylindrical screen and stop means |
US2491072A (en) * | 1945-06-19 | 1949-12-13 | Perkin Elmer Corp | Schmidt television projector with spherical aberration corrector |
US2495035A (en) * | 1942-05-13 | 1950-01-17 | Rauland Corp | Schmidt projector having cathoderay tube comprising spherical mirror |
US2529134A (en) * | 1947-10-02 | 1950-11-07 | Rauland Corp | Support for electron guns |
US2538852A (en) * | 1945-12-29 | 1951-01-23 | Rauland Corp | Kinescope projection by refractive optical system mounted on tube neck |
US2566713A (en) * | 1947-04-04 | 1951-09-04 | Rca Corp | Color television |
US2585009A (en) * | 1945-08-02 | 1952-02-12 | Farnsworth Res Corp | Concentric optical system |
US2673977A (en) * | 1949-01-03 | 1954-03-30 | Rca Corp | Schmidt television projector |
US3446916A (en) * | 1964-07-29 | 1969-05-27 | United Aircraft Corp | Collimated viewing system |
FR2416548A1 (en) * | 1978-02-06 | 1979-08-31 | Kloss Henry | PROJECTED TELEVISION TUBE ENVELOPE AND ITS MANUFACTURING PROCESS |
US4365183A (en) * | 1978-02-06 | 1982-12-21 | Kloss Henry E | Projection televison tube and process for forming same |
US4409515A (en) * | 1978-02-06 | 1983-10-11 | Kloss Henry E | Projection television tube and process for forming same |
-
1941
- 1941-07-31 US US404826A patent/US2305855A/en not_active Expired - Lifetime
-
1942
- 1942-07-30 GB GB10640/42A patent/GB559214A/en not_active Expired
Cited By (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2449259A (en) * | 1941-07-01 | 1948-09-14 | Hartford Nat Bank & Trust Co | Schmidt type optical system with parallel plate refractive element |
US2495035A (en) * | 1942-05-13 | 1950-01-17 | Rauland Corp | Schmidt projector having cathoderay tube comprising spherical mirror |
US2440735A (en) * | 1943-06-05 | 1948-05-04 | Farnsworth Res Corp | Electrooptical device |
US2435316A (en) * | 1943-11-01 | 1948-02-03 | Farnsworth Res Corp | Optical focusing means for image translating devices |
US2448476A (en) * | 1943-12-03 | 1948-08-31 | Rauland Corp | Cathode-ray projector tube |
US2482151A (en) * | 1944-08-18 | 1949-09-20 | Philips Lab Inc | Cathode-ray projection tube |
US2459637A (en) * | 1944-11-29 | 1949-01-18 | Motorola Inc | Cathode-ray image-translating device |
US2482566A (en) * | 1945-06-16 | 1949-09-20 | Philco Corp | Image-projection optical system with cylindrical screen and stop means |
US2491072A (en) * | 1945-06-19 | 1949-12-13 | Perkin Elmer Corp | Schmidt television projector with spherical aberration corrector |
US2458132A (en) * | 1945-06-19 | 1949-01-04 | Perkin Elmer Corp | Schmidt image former with spherical aberration corrector |
US2481615A (en) * | 1945-06-23 | 1949-09-13 | Philco Corp | Image projection optical system with cylindrical screen means |
US2585009A (en) * | 1945-08-02 | 1952-02-12 | Farnsworth Res Corp | Concentric optical system |
US2538852A (en) * | 1945-12-29 | 1951-01-23 | Rauland Corp | Kinescope projection by refractive optical system mounted on tube neck |
US2453003A (en) * | 1946-03-07 | 1948-11-02 | Pye Ltd | Television projection tube |
US2566713A (en) * | 1947-04-04 | 1951-09-04 | Rca Corp | Color television |
US2529134A (en) * | 1947-10-02 | 1950-11-07 | Rauland Corp | Support for electron guns |
US2673977A (en) * | 1949-01-03 | 1954-03-30 | Rca Corp | Schmidt television projector |
US3446916A (en) * | 1964-07-29 | 1969-05-27 | United Aircraft Corp | Collimated viewing system |
FR2416548A1 (en) * | 1978-02-06 | 1979-08-31 | Kloss Henry | PROJECTED TELEVISION TUBE ENVELOPE AND ITS MANUFACTURING PROCESS |
US4365183A (en) * | 1978-02-06 | 1982-12-21 | Kloss Henry E | Projection televison tube and process for forming same |
US4409515A (en) * | 1978-02-06 | 1983-10-11 | Kloss Henry E | Projection television tube and process for forming same |
Also Published As
Publication number | Publication date |
---|---|
GB559214A (en) | 1944-02-09 |
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