US2469992A - Television cabinet with remov able screen controlling focusing system - Google Patents

Description

May 10, 1949. A. H. ROSENTHAL 2,

TELEVISION CABINET WITH REMOVABLE SCREEN CONTROLLING FOCUSING SYSTEM I Filed June 20, 1944 INVENTOR. /50 ADOLPH H. ROSENZ'HAL A TTOQ/QEY Patented May 10, 1949 TELEVISION CABINET VVKTH REMOVABLE SCREEN CONTROLLING FOCUSING SYS- TIEM Adolph H. Rosenthal, New York, N. Y., assignor to Scophcny Corporation of America, New

York, N. Y., a corporation of Delaware Application June 20, 1944, Serial No. 541,154

3 Claims. 1

This invention relates to an apparatus for rebeiving and visibly reproducing signals, in particular television signals, for use in homes, offices, schools, lecture halls and other auditoriums, etc, and which may be combined, if so desired, with a sound receiver and reproducer.

In particular, but not exclusively, the invention relates to a portable type of apparatus for receiving and visibly reproducing signals, in particular television signals, such as for instance of the box or cabinet type.

It is an object of the invention to use the same apparatus for forming a visible reproduction of signals indicative of intelligence of any type, in particular television signals, on a smaller and larger area, and on a smaller or larger scale.

It is another object of the invention to use the same apparatus for forming a visible reproduction of signals, in particular television signals, representative of intelligence of any kind, on a smaller scale on a smaller screen and, alternatively, on a larger scale on another larger screen.

It is a further object of the invention to use the same receiving and reproducing apparatus for forming a visible reproduction of signals, such as television signals, representative of intelligence of any kind, on a smaller scale and on a smaller screen which forms an integral part of the television reproducing equipment, and alternatively on a larger scale on another larger screen which is separated and distant from that equipment.

It is a more specific object of the invention to use a television reproducing apparatus arranged in an essentially light-proof confined space enclosed for instance by a housing or cabinet, for forming an image indicative of intelligence of any type on a screen which is part of said housing, and for projecting from that confined space such image upon another and preferably larger screen on a corresponding scale.

While these and other objects of the invention will be more clearly understood when the specification proceeds with reference to the drawings, it should be understood that the invention is not limited to any particular type of apparatus for visibly reproducin signals, particularly television signals. For instance, apparatus can be used operating on the principles of controlling the optical qualities of a screen, such as a screen the reflecting power or refractive index of which is varied in its magnitudes by an impinging modulated cathode ray beam, or a screen the transparency (or opacity) of which is locally and temporarily varied in similar manner; the invention also includes apparatus using a screen the light reflecting or emitting qualities of which are affected by certain radiant energies impinging upon it, such as fluorescent material type screens. Apparatus operating on supersonic light-modulating principles can also be used. Whatever may be the type of the apparatus for visibly reproducing signals, particularly television signals, used in the unit concerned by the invention, the latter primarily consists in the combination of such apparatus with certain optical devices in specific settings which permit the above exemplified alternative or diversified uses of the same apparatus i or visibly reproducing signals.

Referring to the drawings, Fig. 1 shows rather schematically, partly in vertical cross section and partly in elevation, an embodiment of the invention exemplifying a television reproducing apparatus in a light-proof housing or confined space with a viewing screen forming part of that housing, and another viewing screen at a distance therefrom, Fig. 2 in similar manner a modification of the optical design for projecting a visible reproduction or an image of the received signals, particularly television signals, and Fig. 3 still another modification of that optical design.

Referring to Fig. 1, housing 10 of any suitable material, such as light-weight metal, wood, or plastic material, confines in a light-proof manner a space I I for instance of a portable cabinet. Within housing it a cathode ray controlled light valve, such as a cathode ray tube I2, is arranged which is for example of the design as described more in detail in my Patent No. 2,330,171. It comprises a neck E3 in which the cathode ray gun, including its accelerating electrode or electrodes, deflecting and modulating electrodes is arranged, a transparent front wall [4 on which a transparency-controlled screen I5 of certain ionic crystal material is formed, and an optically perfect front wall it on the opposite side. The housing of the cathode ray tube l2 consists conveniently of glass. As it is described more in detail in my aforesaid patent, the cathode ray stream ll developed by the cathode ray gun is for instance swept over screen I5 by the deflecting electrodes so as to scan screen I5 at desired lineand frame-scanning frequencies, and its intensity is modulated or controlled according to received signals representative of the intelligence to visibly reproduced. The electrical circuits and arrangements for deflecting as well as modulating, etc, the cathode ray beam, and the electrical circuits, connections and means for operating the cathode ray tube are well known in the art and need no detailed description or showing in the drawing.

The circuits for receiving the signals preferably modulated upon carrier waves, and demodulating them may be arranged within or outside confined space H, and in the latter case in an attachment to the cabinet or in a separate unit connected with the reproducing apparatus by cable or the like.

The reproduction of the successively received signals is effected in screen l5 by changing locally and temporarily its optical qualities in the manner described more in detail in my aforesaid patent. The light rays of a proper and preferably concentrated source of visible light l8, such as an incandescent lamp, are directed by a reflector I9 and optical condenser lens system 20 through wall I4, screen l5, wall l6 and objective or imaging lens system 2| upon the light deflector IT, preferably a 45 mirror, and hence focussed upon a Viewing screen 22 of suitable material such as ground glass, forming on screen 22 an image of screen l5.

While the source of light l8, reflector I9, condenser 20 and signal reproducing apparatus or tube l2 are in pre-determined and fixed positions relative to one another as Well as to deflector or mirror ll within the confined space I l, the imag ing lens system 2! is arranged to occupy different positions; in one of them shown in full lines in Fig. 1 the visible light projected through screen I5 is focussed upon screen 22 so as to image thereon the screen I5 on a desired scale.

Screen 22 covers an opening 23 of housing through which it can be viewed by an observer. Screen 22 is brought into position for instance through slit 24- in the top of casing Ill and engages lateral recesses in frame 26 enclosing aperture 23. The lower end of screen 22, or a part 29 connected therewith projects downwardly through a slit 25 in frame 26 so as to rest upon block 2'! which is hingedly connected with one end of a lever 28; the portion of lever 28 extending beyond its fulcrum forms a fork 3| the prongs of which are slit at 32. Vertical rails 34 engage slideably recesses on the outside of mount 33 of the objective lens system 2! so that the latter can be displaced from the position shown in full lines to any other one, for instance the position indicated in dotted lines below. Pins 84 project outwardly on opposite ides of mount 33 and engage a slit 32 each.

If screen 22 is lowered into the position shown in Fig. 1, its projection 29 pushes block 2'? downwardly and turns lever 28 counter-clockwise until it rests upon the adjustable stop 35 formed by the end of screw 36 passing a fixed support 31. In this position of screen 22 and lever 28 lens system 2| occupies its upper position shown in full lines, in which it projects and focusses an image of screen l through deflector or mirror upon the viewing screen 22.

If screen 22 is lifted so as to uncover aperture 23, lever 28 is turned clockwise, for instance by a tension spring 38 fastened at 39 on a projection of frame 26, until lever 28 hits the adjustable stop 40 formed by the free end of screw 4| passing a fixed support '12. In this position of lever 28, lens system 2| has been lowered into the position shown in dotted lines in which it projects and focusses an image of screen l5 over mirror I! upon the other viewing screen 43.

From the above it will be appreciated that the same signal, particularly television signal reproducing apparatus or light valve 12 and optical systems 20, 2|, as well as source of illuminating light l8 and reflector 19 are used for forming an image of the signal reproducing screen l5 either on the viewing screen 22 when it forms a part of the housing it! or of the portable cabinet, or on the other viewing screen 33 when screen 22 is removed.

The following modifications of this embodiment of the invention can be understood by any man skilled in the art without further showing in the drawing.

Although screen l5 can be imaged on the same scale on screens 22 and :33, it will be the rule that the image on screen is on a larger scale. The intensity of the light to be emitted by source [8 will be larger if a larger image is projected upon screen 43 and if the same brightness is required. For this purpose an incandescent lamp of Well known type with two or more filaments can be used; when an image on a smaller scale is to be formed on screen 22, only one or a part of those filaments will be connected with the source of current, such as the mains, whereas upon removal of screen 22, a larger number of or all the filaments provided in the lamp will be switched in. This can be accomplished by manual operation of a switch arranged outside housing If], or automatically in a similar manner as the displacement of lens system 2i, in that for instance lever 28 in its different positions also switches in a difierent number of filaments in the source of light It. Instead of positively changing the intensity of the source of illuminating light dependin upon the presence or absence of screen 22 in frame 26, blocking means can be provided which prevent the shifting of a manually operable switch from its proper position. Instead of a multifilament lamp. two or more lamps of same or different intensities can be used and switched in or out in a similar manner as diiTerent filaments of a lamp. The multifilament lamp is preferred, however, because it permits better focusing of the source of light within reflector IS.

A dial for a manually operated switch can indicate the light intensities produced in the different positions of the switch.

The position of lens system 2| indicated in dotted lines is operative only for a certain distance of the larger viewing screen 33 from mirror ll.

If it be intended to project an image of the tube screen [5 on viewing screens at different distances from mirror IT, and on different scales. then also a corresponding variety of positions of lens system 2| must be provided. To this end lever 28 can be fixedly connected with the axle or shaft 30, the latter project outside a lateral wall of housing l0 and a handle fixed to the projecting end of shaft 30. The handle moves over a dial, marked in distances of screen 43 for instance from the front wall of easing ill, so that lens system 2| is moved into proper position (where maximum sharpness of the picture is obtained) by turning the handle for shaft 32. In this case, of course, spring 38 is omitted and means, such as friction means, are provided which hold shaft 30 in any position in which it is turned. The stops 35, All may still be retained in order to limit the outermost positions of the lens system. The automatic restoration of lens system 2| from any position it may have been moved into in order to project an image upon an outside viewing screen, to the position shown in full lines in Fig. 1 by means of projection 29 of screen 22, can also be retained in such case. However,

if shaft 31! is used for displacing lens system 2!, screen 22 can be hingedly connected with one side, 6. g. the top of frame it, and swung into and out of its operative position, or any other manner of removably connecting it with frame can be used.

There may also be required an adjustment of front surface mirror ll relative to the other elements of the apparatus, and to this end any proper adjusting means can be provided, such as for instance pins M, ib, which are screw-threaded on their free ends, project through lugs dd, 'll and are adjusted by means of nuts 58, 58.

Signal reproducer l2 and all or part of the optical devices and actuating mechanisms shown can be mounted in a frame in which they are properly adjusted relative to one another and the unit comprising the frame and these elements can be inserted into and removed from cabinet ill for instance upon removal of rear wall 5i If imaging or objective lens 26 forms a complex lens system, its focal length and thereby magnification can be made variable, as is well known in the art, by changing the position for instance of a middle lens relative to the outer lenses. Mount and mechanisms for adjusting the magnification of such lens systems are also well known; by connecting for instance a flexible shaft with a lens system ll of variable magnification and of a handle outside a side wall of the cabinet with said. shaft, the magnification or size f the image of any intelligence formed on the tube screen can be controlled by turning that shaft. Thereby the observer or operator is enabled to select the portion of the image on the tube screen to be projected upon either screen or screen ts at a given distance of the latter from the cabinet, in that by adjusting a smaller magnification a larger portion of or the entire image formed on the tube screen is focused and. projected on a smaller scale either of the viewing screens 22 or whereas by adjusting a larger magnification by lens system if only a central portion of the tube screen and i e formed therein is projected and imaged on a larger scale on either viewing screen.

The front wall of cabinet ill can be provided with an opening 55 inside of which a loudspeaker 52 is fixedly or removably mounted.

A proper dial board can be arranged for instance on a side wall of the cabinet, with switches and handles to the following effect.

One switch or handle for controlling the brightness of the projected. image, i. e. for adjusting the light intensity of illuminating source E8 as hereinbefore ribed; another handle for displacing lens system if this is not acted automatically by changing the position of screen 22; another handle for selecting the carrier wave frequency on which tr signals to be reproduced are received; another handle for turning mirror ll in an arrangement illustrated in Fig. 2; another handle for selecting sound to be reproduced by loudspeaker in synchronism with received c ture, etc, which can be combined. ever, with the other handle for selecting the to vised signals; and another handle for adjus- -J the magnification by lens system 2 i. If the electrical circuits for receiving the vised signals and sound are separated from cabinet ill, the cor responding controls or will be preferably provided on a dial board for those circuits,

Referring to Fig. 2 there is illustrated a signal, particularly television signal reproducing apparatus comprising a cathode ray tube it with neck [3 the same in principle as hereinbefore described with reference to Fig. 1. The tube screen 53 is, however, in this case of a light reflecting type, i. e. its light reflecting qualities are affected by an impinging or scanning cathode ray beam. Coaxially with tube screen 53 is arranged a source of light it with reflector-mirror I9 so that the light emerging from source it and also that reflected by mirror is is projected by condenser lens system 541 upon the reflecting screen 53, hence upon the spherical mirror 55 and by the latter through a Schmidt correction aspherical lens 56 upon light deflector or mirror ll arranged at an angle of 45 with respect to axis 51'. By adjusting the position of lens 5% (which can be made of plastic material) and/or mirror 55 the image of reflecting tube screen 53 can be focused either upon the smaller viewing screen 22 in its position shown in Fig. 2, or upon an outside screen the same as screen in Fig. l, or as assumed in this exemplification of the invention, arranged on the opposite side with respect to housing iii. In order to project the image to the opposite side upon screen as, mirror ill can be turned by about in the direction of arrow Ell into the position shown in dotted lines by means of shaft 63 projecting through a side wall of housing If) and provided with a handle at its outside end. In this case screen 22 can be fixed in frame 28 and need not be removed when the image of tube screen 53 is to be projected upon the outside viewing screen so (not shown). The light rays reflected by mirror H in its position shown in dotted lines pass an opening Ila; in casing ill; a cover 35 may be provided for this opening which closes it when mirror ll is in the position shown in full lines and is opened automatically, if desired, upon turning mirror il in the position shown in dotted lines; cover es is shown only in its opened position and in dotted lines. Automatic closing and opening of cover 65 can be effected for instance by coupling its axle so by a suitable transmission with shaft '53 for turning mirror ll. Similarly, if no separately operable means are provided for changing the position of lens system 56 and/or mirror ior imaging tube screen 53 upon either viewing screen 22 or it, such change can be effected automatical y by a mechanism interposed between shaft 63 and the mount of lens system 56 or support of mirror 55.

It is understood that a rotatable mirror H can also be used with the embodiment of the invention exemplified in Fig. 1, and in such case for instance shaft 3t for adjusting the position of lens system M can be coupled by a suitable transmission with shaft 63 (and axle 66).

It is assumed in Fig. 2 that the loudspeaker is removed that opening iii in the front wall of cabinet ll? is light-proofed by removable cover 58. However, the arrangement of a loud speaker is in any case arbitrary and not essential to th invention.

The embodiment of the invention exemplified in Fig. 3 also applies to a signal, particularly picture signal reproducing apparatus of the refiecting tube screen type and differs from the one shown in Fig. 2 in that the light emitted from illuminating source l8 and reflected by mirror It is projected through lens as and a l5 reflecting prism be combined with field lens iii! through an aperture ill in lens 55 upon the reflecting tube screen 53 and hence through imaging lens 56 upon the i5-mirror l'l.- Thereby an image of tube screen 53 is formed on translucent viewing screen 22. Upon removal of screen 22 and proper adjustment of the position of imaging lens 56, an image of tube screen 53 can be formed on any desired scale of magnification on an outside screen the same as screen 43 in Fig. 1. In this embodiment of the invention a part of or the entire circuit arrangement for receiving the television signals is arranged inside cabinet at 82. Rear wall 50 can be removed and serve as support for a frame in which all the optical elements and the cathode ray tube of the signals visibly reproducing apparatus are mounted.

It should be understood that all the details described and indicated with reference to Fig. 1 for adjusting lens system 2| either automatically or manually or for blocking it, depending upon the position of viewing screen 22, are analogously applicable to the embodiments exemplified in Figs. 2 and 3, for adjusting the position of mirror 55 or lens system 55 and the intensity of the source of illuminating light l8.

It should be further clear that by turning the signals, particularly television signals reproducing apparatus and optical elements cooperating with it, by an angle of 90, so that axis 57 in Figs. 2 and 3 is horizontal, the 45-mirror IT can be omitted and an image of tube screen 53 formed directly by lens 56 upon screen 22 or, upon the latters removal, through aperture 23 upon an extraneous viewing screen similar to screen 43 in Fig. 1. If it is desired in such case to project the picture either upon a fixed screen 22 or in opposite direction upon an outside screen 43, the unit comprised of the light valve and optical devices can be arranged rotatable about 180. Furthermore, in such case screen 22 can be omitted and tube screen 53 (or 15) viewed directly by the observer through aperture 23 in housing I0.

It should be further understood that the invention is not limited to any exemplification hereinbefore described or shown but is to be derived in its broadest aspects from the appended claims. In these claims the term intelligence comprises any information capable of being visibly reproduced, including, but not by way of limitation, living or inanimate objects and settings, physical phenomena, pictures, images, writings and printed matter. The term radiant energy controlled light valve includes any apparatus including a screen the self-luminescent, or light reflecting or transmitting optical qualities of which are locally and temporarily changed by suitable radiant energy (such as cathode rays, X-rays, and radium rays) which in turn is controlled by electric signal impulses representative of intelligence. It should be clear that if a selfluminescent screen be used, the illuminating and optical means for projecting the formers light upon the screen are to be omitted, while the optical means for focusing light rays emerging from a self-luminescent screen upon the outside viewing screen, and alternatively upon the cabinet screen, if provided, are of course retained. The term optical means used in the claims includes any lens system, complex or comprising a single lens only or mirror system with or without correction plate, which is capable of projecting and focusing light emerging from, i. e. generated or reflected by or transmitted through the screen of a radiant energy controlled light valve, on a viewing screen so as to visibly reproduce thereon the signal impulses impressed upon the valve. The term light rays includes rays of light within the visible, invisible and nearly visible spectral regions of light, including the visible light spectrum and the short and long wave light ray ranges near the end of that spectrum, such as ultra-violet and infra-red rays, which are capable of being visibly reproduced on a suitable viewing screen,

What I claim is:

1. An apparatus for visibly reproducing electric signal impulses representative of intelligence, essentially comprising, in combination, within enclosed space a device including a screen layer controlled by cathode rays for visibly reproducing said signals, a viewing screen associated with the enclosure of said space which can be observed from the outside, adjustable means for directing light rays in variable intensity upon said screen layer, adjustable optical means within said space for focusing in one of its adjustments light rays emerging from said screen layer on said viewing screen, an aperture in said enclosure through which said optical means in another one of its adjustments can focus light rays emerging from said screen layer on another viewing screen outside said enclosure, and controlling means between said light ray directing means and said optical means for securing a smaller intensity of light rays when said optical means are focused on said viewing screen associated with the enclosure and a larger intensity when said optical means are focused on said outside viewing screen.

2. An apparatus for visibly reproducing electric signal impulses representative of intelligence on a viewing screen by means of light rays emerging from a cathode ray controlled light valve upon which said impulses are impressed, essentially comprising, in combination, within enclosed space a radiant energy controlled light valve, means for directing light rays upon said valve, light ray deflecting means exemplified by an oblique front surface mirror in the path of light rays emerging from said valve, an aperture in the enclosure of said space, a viewing screen removably associated with said enclosure and arranged so that it can be observed from the outside through said aperture, adjustable optical means arranged in said path for directing light rays emerging from said valve upon said deflecting means whence they are projected upon said viewing screen, said optical means in one of its adjustments capable of focusing said light rays on said viewing screen when it is in observation position relative to said aperture, said optical means in another one of its adjustments capable of focusing light rays emerging from said valve and projected by said deflecting means through said aperture, when said viewing screen is removed, on another viewing screen outside said space, and automatic means for controlling the adjustment of said optical means dependent on the position of said removable viewing screen, so that said optical means are adjusted to focus light rays emerging from said valve upon said viewing screen when it is in observation position and to focus said light rays on said other viewing screen at given distance from said space when said viewing screen is removed.

3. An apparatus for visibly reproducing electric signal impulses representative of intelligence selectively on at least two viewing screens differently located with respect to a cathode ray-controlled light valve upon which said impulses are impressed, including, in combination, within a cabinet housing a radiant energy controlled light valve, optical means in the path of light rays emerging from said valve, said optical means and valve adjustable relative to one another so that said light rays can be directed and focused onto 9 a selected one or at least two screen areas differently located with respect to said optical means and valve, an aperture in' said housing in the path of light emerging from said valve and directed by said optical means, a viewing screen removably associated with said housing so as to essentially cover said aperture and arranged so that it can be observed from the outside, said optical means in one of their relative adjustments capable of focusing said light rays on said screen when it is in observation position, said optical means in another one of their relative adjustments adapted to focus said light rays through said aperture, when said viewing screen is removed, onto another viewing screen outside said housing, and automatic means for adjusting said optical means in said positions and actuated by said viewing screen when it is brought into its observation position and removed therefrom, respectively.

ADOLPH H. ROSENTHAL.

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

UNITED STATES PATENTS Number Name Date 1,738,445 Oehmichen Dec. 3, 1929 2,022,903 Thomas Dec. 3, 1935 2,070,226 Erwood Feb. 9, 1937 2,163,918 Schwartz June 27, 1939 2,231,395 Schlegel -1 Feb. 11, 1941 2,273,801 Landis Feb. 17, 1942 2,283,268 Kreinin May 19, 1942 2,287,307 Herbst June 23, 1942 2,330,171 Rosenthal Sept. 21, 1943 FOREIGN PATENTS Number Country Date 103,816 Australia Apr. 26, 1938 496,835 Great Britain Dec. 7, 1938

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