New! View global litigation for patent families

US2415311A - Cathode-ray tube projector - Google Patents

Cathode-ray tube projector Download PDF

Info

Publication number
US2415311A
US2415311A US56950144A US2415311A US 2415311 A US2415311 A US 2415311A US 56950144 A US56950144 A US 56950144A US 2415311 A US2415311 A US 2415311A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
layer
fluorescent
mirror
surface
tube
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
Inventor
Constantin S Szegho
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.)
Rauland Borg Corp
Original Assignee
Rauland Borg Corp
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
Grant date

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/74Projection arrangements for image reproduction, e.g. using eidophor

Description

Feb. 4, 1947. c. s. SZEGHO CATHODE R AY TUBE PROJECTOR Filed Dec. 23, 1944 w J mi F m & 7 M $0 Y M ATTORNEY Patented Feb. 4, 1947 'lf'A'lES PATENT OFFICE GATHODlE-RAY TUBE PROJECTOR Constantin S. Szcgho, Chicago, 111., assignor to The Rauland Corporation, Chicago, Ill., a corporation of Illinois 3 Claims.

This invention relates to new and useful improvements in cathode ray tube projectors of the kind employed in large screen television receivers. This is a division of my application Serial No. 442,835, filed May 13, 1942.

The object of the invention is to increase the light output of projectors using a mirror optic, such as the Schmidt camera. (James G. Baker: The solid-glass Schmidt camera and a family of flat-field cameras, equivalent in performance to the Schmidt camera. Proceedings of American Philosophical Society, vol. 82, No. 3, April 30, 1940.)

In the Schmidt camera type of projector a cathode ray tube having fluorescent material deposited on a transparent support, usually a wall of the cathode ray tube, is located between a large diameter spherical mirror and a correcting plate. The light is first produced at the cathode or back side of the surface of the fluorescent powder and then passes through the powder to emerge from the front surface contacting with the transparent support, usually the end Wall of the tube. The electrons impinge on the back side surface of the layer. The outside surface faces the spherical mirror. In such back surface projection much of the light is lost by absorption in the fluorescent layer.

In accordance with the present invention, the light output of the projector is increased by providing a front surface projection cathode ray tube between the mirror and the correcting plate of a Schmidt camera type of optical system.

In the drawing:

Fig. 1 is a diagrammatic illustration of one embodiment of this invention; and

Figs. 2 and 3 illustrate two methods for assembling the tube of Fig. 1.

An embodiment is illustrated in Fig. 1 in which 2! is an evacuated glass envelope having a neck 22. The neck encloses an electron gun 23 and vertical and horizontal deflecting plates 2 The bell-shaped main chamber of the envelope 21 contains a disc 25 of aluminum having a thickness of approximately 5 microns. The disc is curved and has its convex surface coated with a layer of fluorescent material 26. The curved end wall 21 of the envelope 2! is parallel with the adjacent coated aluminum disc 25 and faces a spherical mirror 28. The neck 22 of the tube projects through a central opening in a correcting plate 28. The mirror 28 and plate 29 constitute a Schmidt camera type of optic, the radius of curvature of the disc 25 being the focal length of the optic.

High voltage electrons produced by the gun 23 will pierce the aluminum member 25 and penetrate the fluorescent layer 26 to cause the eXcitation of its outside surface near the window 21 which will allow substantially all the light from the fluorescent screen to reach the mirror 28. At the customary anode voltage of approximately 50,000 volts, the energy loss of electrons going through such aluminum disc is only about 5%. No negative charge will be present to slow down the electrons which can, therefore, penetrate to a suflicient depth into the fluorescent layer 26 to produce the necessary light effects.

If the space between the spherical mirror and the correcting plate is filled with a liquid of high refraction index the light output of this arrangement can be further increased by a factor which is the square of the refraction index. Instead of filling the space with an immersion liquid this space can be filled with solid material such as glass or plastic. In this case the spherical mirror and the correcting surface will preferably constitute the end faces of the solid.

Figs. 2 and 3 show two arrangements for assembling the tube structure schematically illustrated in Fig. 1. In Fig. 2, the curved aluminum disc 25 is mounted on wires 30 connected with the anode structure 3! in the neck 32 of a glass envelope. The body of the envelope 33 is cylindrical, the end of which may be closed by a flat glass window 34 during which operation the anode structure with the fluorescent screen is withdrawn towards the cathode. In the structure shown in Fig. 3, the aluminum disc 25 is supported 0n wires 35 which are sealed into the wall of cylinder 36, one end of which is closed off by a flat window 31; the other open end may be joined to the neck portion 38 of the tube at such a distance from the aluminum member that it wil1 not be damaged. What I claim is:

1. In combination, a fluorescent layer, a layer of conducting material in contact therewith, an electron gun emitting electrons which penetrate through said conducting layer into said fluorescent layer, a mirror for reflecting 1ight emanating and emerging from the exposed surface of said fluorescent layer, and a correcting plate in the path of the light rays reflected by said mirror.

2. In combination, a fluorescent layer, a layer of conducting material therefor, an electron gun emitting electrons which penetrate through said conducting layer into said fluorescent layer, an evacuated envelope having a transparent end wall parallel with said conducting layer and through 3 which said fluorescent layer is visible and a neck enclosing said gun, a mirror for reflecting light emanating and emerging from the exposed surface of said fluorescent layer, and a correcting plate in the path of the light rays reflected by said mirror.

3. In combination, a fluorescent layer, a convex layer of conducting material therefor, an electron gun emitting electrons which penetrate through said conducting layer into said fluorescent layer, an evacuated envelope having a transparent end made parallel with said conducting layer and adjacent thereto and a neck opposite said conducting layer and symmetrically positioned with re spect thereto, said neck enclosing said gun, a Spherical mirror for reflecting light emanating and emerging from the exposed surface of said fluorescent layer, and a correcting plate in the path of the light rays reflected by said mirror, and having a central aperture through which said neck pro- J'ects.

CONSTANTIN S. SZEGHO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,336,134 Szegho Dec. 7, 1943 2,298,808 Ramberg Oct. 13, 1942 2,295,779 Epstein Sept. 15, 1942

US2415311A 1942-05-13 1944-12-23 Cathode-ray tube projector Expired - Lifetime US2415311A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US2495035A US2495035A (en) 1942-05-13 1942-05-13 Schmidt projector having cathoderay tube comprising spherical mirror
US2415311A US2415311A (en) 1942-05-13 1944-12-23 Cathode-ray tube projector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US2415311A US2415311A (en) 1942-05-13 1944-12-23 Cathode-ray tube projector

Publications (1)

Publication Number Publication Date
US2415311A true US2415311A (en) 1947-02-04

Family

ID=27033308

Family Applications (1)

Application Number Title Priority Date Filing Date
US2415311A Expired - Lifetime US2415311A (en) 1942-05-13 1944-12-23 Cathode-ray tube projector

Country Status (1)

Country Link
US (1) US2415311A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2473320A (en) * 1946-03-07 1949-06-14 Cossor Ltd A C Cathode-ray tube
US2520190A (en) * 1946-10-24 1950-08-29 Philips Lab Inc Cathode-ray tube
US2525832A (en) * 1946-02-20 1950-10-17 Sheldon Edward Emanuel Tube with composite photocathode for conversion and intensification of x-ray images
US2544690A (en) * 1946-12-26 1951-03-13 Du Mont Allen B Lab Inc Color television
US2553182A (en) * 1946-11-01 1951-05-15 Cage Projects Inc Color television
US2663012A (en) * 1952-01-30 1953-12-15 John R Beers Projection television tube

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2295779A (en) * 1940-08-17 1942-09-15 Rca Corp Projection apparatus
US2298808A (en) * 1941-04-26 1942-10-13 Rca Corp Television projection system
US2336134A (en) * 1942-05-13 1943-12-07 Rauland Corp Color television system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2295779A (en) * 1940-08-17 1942-09-15 Rca Corp Projection apparatus
US2298808A (en) * 1941-04-26 1942-10-13 Rca Corp Television projection system
US2336134A (en) * 1942-05-13 1943-12-07 Rauland Corp Color television system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2525832A (en) * 1946-02-20 1950-10-17 Sheldon Edward Emanuel Tube with composite photocathode for conversion and intensification of x-ray images
US2473320A (en) * 1946-03-07 1949-06-14 Cossor Ltd A C Cathode-ray tube
US2520190A (en) * 1946-10-24 1950-08-29 Philips Lab Inc Cathode-ray tube
US2553182A (en) * 1946-11-01 1951-05-15 Cage Projects Inc Color television
US2544690A (en) * 1946-12-26 1951-03-13 Du Mont Allen B Lab Inc Color television
US2663012A (en) * 1952-01-30 1953-12-15 John R Beers Projection television tube

Similar Documents

Publication Publication Date Title
US3284655A (en) Cathode ray tube mesh assembly supported between envelope sections
US3446916A (en) Collimated viewing system
US3225241A (en) Aperture fluorescent lamp
US3746911A (en) Electrostatically deflectable light valves for projection displays
US2523132A (en) Photosensitive apparatus
US3058021A (en) Optical coupling device between x-ray intensifier and vidicon camera tube or the like
US3712986A (en) Electron imaging device utilizing a fiber optic input window
US2739243A (en) Composite photosensitive screens
US3385927A (en) Display device utilizing a medium that alters the degree of refraction of light
US5994824A (en) Light weight/small image intensifier tube
US3603828A (en) X-ray image intensifier tube with secondary emission multiplier tunnels constructed to confine the x-rays to individual tunnels
US3115309A (en) Aperture fluorescent lamp
US2495697A (en) Method and apparatus for intensifying electronic images
McGee et al. The spectracon—an electronographic image recording tube
US2198479A (en) Image reproduction
US2569872A (en) Electron discharge tube
US2953684A (en) Self-luminous light sources
US2233786A (en) Fluorescent screen assembly and method of manufacture
US2172775A (en) Optical system
US4305099A (en) Light collection system
US2177360A (en) Optical image intensifier
US2219113A (en) Method of electron-microscopically investigating subjects
US2577038A (en) Television color picture tube
US4131818A (en) Night vision system
US3660668A (en) Image intensifier employing channel multiplier plate