US2026610A - Television apparatus - Google Patents

Description

Jamr?, 1936. A J, CAWLEY 2,026,610

TELEVISION APPARATUS @riginal Filed May 25, 1930 .I INVENTOR I 6 v BY 7' f ATTOR N EY FZ" .6a. i i l *I Patented Jan. 7, 1936 PATENT OFFICE TELEVISION APPARATUS Aloysius J. Cawley, Pittston, Pa.

Application May 23, 1930, Serial No. 455,127 Renewed May 24, 1935 3 Claims.

The invention relates generally to the electrical transmission of optical images. More particularly, it consists in forming a light image, and causing electrical fluctuations and modifications to be made in certain electrical apparatus hereinafter described. These electrical iiuctuations are transmitted by wire or other conductor, or by electric waves to the` receiving point where suitable modifications .are made Iin an electrical apparatus associated with optical means, whereby an image of the original objects` showing all oi their movements obtained.` At the transmitter an element carrying a plurality of photoelectric cells is revolved rapidly in an image area. At the receiving station a similar member is revolved which carries a plurality of light sources or glow lamps which are illuminated in accordance with the image current or image modulated electric waves which are transmitted thereto 'ii-f from the transmitting station. The result is that` the said light sources reproduce the original image.

A rotating contact member is provided which makes contact at the transmitting station with but one photoelectric cell at a time, while a simi' lar member is provided at the receiving station which makes contact with but one lamp on the rotating arm at a time. Both cells and lamps describe a series of interrupted, concentric circles. This contact member may berotated at the same speed as the arms, but in a direction opposite thereto, 4or at a speed which is a multiple of the speed of the arm, as desired. `The apparatus y has therefore, great exibility.

A very desirable modification is one which provides both photoelectric cells and light sources or glow lamps on the same rotating element at` both the transmitter and receiver cooperating with their corresponding contactmaking or commutating elements. Thus, one image may be transmitted .while another is reproduced in the same image eld, giving two-way television,v`

which differs `from present methods in that the transmitted and received Vimages are coextensive .and also that the photoelectriceells and lamps are actuated alternately,` sothat it is impossible for the light of the glow lamp tofbe reected from the face of the observer and retransmittea to the distant station. o y

This application is a. continuation-in-part of my .application Serial Number 380,202, led July 22, 1929, for Television apparatus. f

I attain the above objects by the apparatus 55 illustrated the accompanying drawing, in

which like reference characters have similar meanings, and in which, Y

Figure l is a plan View of a receiver. A fluorescent screen is also shown in this figure which may be used if desired to augment the action of the retina.

Figure 2 is an elevational view of a transmitter and illustrates the arms carrying the radially arranged photocells together with their contact means and revolving mechanism. A means for imparting any desired speed is also illustrated in this figure.

Figure 3 is an elevational end view of the appapatus for imparting variable speed to the transmitter or receiver illustrated in Figures 1 or 2.

Figure 4 shows an arrangement which combines the receiver and transmitter in a single unit l Figure 1 is a plan view of the receiver, and il` lustrates that portion of the apparatus upon which the picture is to be displayed. A iiuorescent screen in the form of an Octagon is shown at I1. It `may or may not be used, 'as it is not absolutely essential. It acts to retain a record of the flashes of the lamps which occur in the processof production of a visual image, and assists the eye in executing the function of persistence of vision. It retains the image from one revolutionV of the arm to another. In other words, it retains one of the complete pictures .until the next is traced upon it in the form of fluorescent light. The screen is shown placed upright for viewing the picture'. screen is an arm 3 carrying a row of neon lamps 4. Small incandescent lamps may be used, or

any ,other glow lamp besides theV neon; such asV helium, etc.` The arm corresponds to the diameter of the circle through which it rotates. This arm is pivoted and fixed in shaft `.2, and is rotated by it. The jneon lamps are shown disposed as one radius of the circle, that is, they occupy half of the arm. However, they may be placed all of the way across it, i. e., they may be placedralternately. Those 'shown are spaced and wherever there ls a space, 'a lamp may be placed on the opposite side of the arm to illuminate what Behind the However, in the figure they are shown as being located on one side of the arm. Wire J designates a plurality of wires each of which connects to a lamp, and thus connects the lamp to a series of brushes. Each lamp is connected to a brush l. This is done by means of short connecting wires. The lamps may consist of a single glass tubing containing a number of pairs of electrodes E, or they may consist of a number of separate tubes provided with either internal or external electrodes 6. The row of contact brushes is located under the upper portion of the arm 3. The latter arm is made in two sections, the lower section having the brushes l attached in a stepped relation which is clearly illustrated at the left extremity of arm 3. It will be noted that the brushes are stepped so that only one is shown making contact with conducting ridges z' at any one instant. The lower section of the arm has a stepped contour as shown for this purpose. The row of brushes is intended to be directly under the lamps as shown in the two other illustrations. Attention is particularly directed to the stepped arrangement of the brushes, as this Vis the'factor that causes but one lamp or photoelectric cell to be supplied with electric current at any instant, and is very important. The ridges etc., are simply raised on the surface of the metal contact disk 8, and may be stamped in, if desired. A disk may be cut and stamped in a fraction of a second in manufacture. 'Ihe thickness of disk 8 and the height of the ridges i need not'be that shown. A very thin plate is desirable, as it may be rotated at a greater speed than a thick one. However, if desired, a heavy rim may be given to the disk, to give it a speed governing, speed uniformity, fly Wheel effect. The

arm need not be rotated at a speed greater than fifteen revolutions per second, but the disk may be geared to move many times as fast as that. Each multiple of the speed of the arm that the disk attains means greater definition to the image.` For instance, if the disk moves three times as fast as the arm, there will be two eXtra sets of illuminated radii of the circle shown in Figure 1. This will be better understood later.

In the operation of the receiver, arm 3 is made to rotate at ar uniform speed, say fifteen revolutions per second and is in synchronism with a similar arm at the transmitting station. Obviously, as theY lamps i are illuminated, a series Vof luminous, interrupted, concentric circles will Ybe described. Each lamp traces a circle consistscribed by any particular lamp. 4The space between contact ridges i, etc., may or may not be covered with insulating material, such as bakelite, shellac, bitumen, pitch, mica composition, etc.; however, as the ridge isnraised, air insulation 'may be used entirely.

It is evident that many different types of contact configurations may be given to the surface may be used in various designs.

of the disk 8 besides that shown. Contact points It would be usearm and disk in opposite directions is described 2,026,610 Vwould be a dark circle, when the arm is rotated.

in connection with Figure 2. This and other means were described in connection with the above mentioned application.

Figure 2 shows a very compact arrangement for transmission. I is the motor, whose shaft 2a carries two long keys n. Upon the shaft is loosely mounted a disk V, having an opening therein to iit the keyed shaft. The hub Y of this disk is grooved to accommodate the handle h. It will thus be seen that the disk or wheel may be slid along the shaft by means of the handle h. 'Ihis disk is in contact with the face of the wheel 3', and gives motion thereto. It may be shifted to any point on the radius of the wheel 3 desired, and thus to impart any degree of speed thereto desired. This means is simpler than that usually employed wherein the motor is shifted or moved bodily.

Several methods of operating the apparatus were described in the above mentioned application. Another means is as follows. Wheel 3 rapidly rotates the smaller wheel 9 mounted upon shaft 2', and this in turn rotates the larger member lll of the pair of internal gears. The latter moves the internal wheel Ilia, which is directly attached to disk 8, but which moves freely on shaft 2. Shaft 2 moves arm 3 to which it is firmly attached. Arm 3 carries the photoelectric cells 2l. A cylindrical lens I6 may or may not be used to concentrate the light.

Current passes through wire a to the commutator c insulated from shaft 2V by insulation e, through wire d into the hole in the shaft to wire Il, which supplies the current consecutively to the different photoelectric cells 2l, according to which cell has its brush 'l' in contact with the ridge z'. Thus current can only pass through one photoelectrlc cell at any one instant. Current passes from the cell 2l to the connecting wire to brush l, to ridge z' or disk 8, to shaft 2, and thence to collector ring lc, to brush b, to Wire m, to external circuit. The receiver differs from the transmitter in that glow lamps or other light sources are used in place of the photoelectric cells.

If desired, in all of the apparatus illustrated, the connecting wire Il may be eliminated, especially in connection with the neon tubes 4 in Figure 4. Neon lamps may be lighted by connecting them with but one terminal of a high frequency current circuit.

. Figure 3 is an end view of the disk V and its hub Y, showing its manner of sliding on the shaft 2a.

Figure 4 illustrates a very compact system of two way television, which may be used in telephone booths, and the like. It consists of a transmitter and receiver similar to those described in Figures 1 and 2 and in the above mentioned application, with the distinction that the photocells and glow lamps are combined on the same rotating member at both the communicating stations. The two arms 3 and 3a move in synchronism, although it is to be understood that they may be many hundreds of miles apart. Means for rotating shaft .2 with its arm 3 and disk were clearly described and illustrated in my application Serial Number 380,202, filed July 22, 1929. Such means are also described in connection with Figure 2 of this application. Any rotating means desired is therefore indicated at M and Ma. Therefore arms 3 and 3c as well as disks 8 and 8a rotate in synchronism at both stations. The disks and arms rotate Vin opposite directions.

fIn Aonestation or telephone booth, ann `311 carries onone of its halves a series ofiphoto'f electric cells 2|, and on the other half 'a series .r of neon tubes 4. The lens elements 22 and '22a form Visual images at each station. Obviously,

the `photcelectric elements rotating on the arms act to both vconvert the visual image into` imageL varied current, and convert the incoming irn- .a'gevaried current into an optical image. vA

person facing the right side ofthe iigure hashis imageirnpressed on photcelectric cells 2I`, which are suppliedwith energy by power supplying means indicated by the square D. Thisenergy `passes through brush la to disk 8, through ridge tOr, while viewing the image of the first, has in turn his image impressed upon the photcelectric cells 2lb on arm 3 by lens elements 22 on his portion ofthe apparatus. Thisimage is illustrated as being transmitted by meansof wireless, in contrast to the wire transmission just described. t indicates the transmitting station, its energy being supplied bythe usual apparatus indicated by the square labelled Transmitting apparatus. The current from this passes to :the cells 2lb to wireto brush 1f, toridge i on disk 8 to peripheral brush K'lc making contact with diskv 8, and yback to the power Vsource atthe transmitter. The energy is sent by radio waves from one antennato the other, whence .it is received and amplined by the receiving station 1', supplied to disk 8 by its peripheral brush 'Id andthence to ridge i, to brush 1g, towire, to

neon tubes 4, to common wire lla and back to the receiving station amplifying circuit. The neon tubes 4 may be of a type which exists on the market today. They may be illuminated by simply pressing them against an electrode carrying a high frequency alternating current. `But one lconnection is necessary to light them. The photcelectric cells 2| are of the cylindrical type and are made very small. Head and shoulder picytures are now transmitted by television in practice, as a 48 line picture is capable of transmite ting nothing more satisfactorily on account of lack of detail. Head and 'shoulder pictures will be sufficient to carry on telephone conversation accompanied by television. The system herein illustrated also possesses the great advantage that the speaker is shown on the receiving portion as looking directly at the one spoken to and not away from him, as is necessary in other types of television.

Another feature of the apparatus is that it may be used to transmit colored pictures. Each alternate photcelectric cell 2l may be provided with a suitably colored glass, for instance, the first having blue-violet and the second having an orange-red. The corresponding neon tubes will be provided at the receiving station, i. e., the orange-red will be connected toa neon tube, while the blue-violet will be connected with a mercury or helium, or argon, etc., glow tube. Instead of connecting and equipping alternate tubes in the same row as described, a special row on a separate arm ordisk may-be provided. For instance, there will be a radial arm carrying only blue-violetV photcelectric cells, `another arm for orange-red, another arm carrying neon glow in contact. VIn other-words, there is an alternate making of contacts with the glow tubes and the photcelectric cells. There is not a simultaneous making oi contact. This is very important, as the system is positively two-way in character; 'Ihisprevents the photcelectric cells from receivinglthe light "of the glow lamps that may be refiected back from the faceof the operator. The glow lamps in an extremely small fraction of a second, flash a portion of the image and are then cutout of circuit. Then the photocell is cut in circuit and receives a part of its image, and so on. Of course, separate contact disks 8 and separate circuits may be provided if desired for each radial row of glow tubes and each row of photoelectric cells.

It will be seen in all ofthe above apparatus;

that disk 8 of the receiver is. charged at all times during which a photo cell is` connected at the transmitter to its disk, with the image varied current,man'd is fed to the lights one at in what may be termed radial strokes. On arm 3 there is a row of brushes 1 etc., which make contact with ridges i, etc., of disk 8. Those ridges are so designed, as shown at the left of Figure l, that but one `brush 1 makes contact at any one time br'instant'with ridge i, and only one photcelectric element such as 4 will produce a corresponding intensity of illumination lamp 4, in accordance with'the intensity of .illuminationiin that portion of the image that isin relation with the corresponding photcelectric Y cell at the transmitter.

"sudying the configurations of the disk 8, it

will be seen that as arm 3 is rotated at say fifteen times per second, and'rememb'eriii'g that but one brush 'l can be brought in contact` with ridges i, etc., at a time, and consequently but one light will be illuminated at a time, there will be a series of broken, concentric circles of luminosity, each them in their exact proportion, as the brushes are very small in comparison to the disk or arm. Disk 8 may be in the form of a sprocket wheel, or as a disk having wires placed radially in lieu of ridges i.

It will therefore, be seen that as arm 3 is rotated at say fifteen times per second, the image will appear 4as a diifused, illuminated electric image in which there is a radial building up of the diffused, interrupted, concentric circles. The radi-al illumination will slant somewhat away from a true radius, due to the stepping of the contact brushes as described above.

Disk 8 may be designed as stationary and attached to the frame of the apparatus, as in the form of the invention described and illustrated `a time t this means that c rre'sponding to the path of a neon lamp on,

in connection with sheet i of the drawing. It`

equal to the sum oi their speeds. In the more expensive iorms of the apparatus, disk 8 will be 10 .given a speed of rotation that is many times that ofl arm 3, if desired. If it revolves twentyone.

times as fast as arm 3, the relative speed is 315 rotations per second,A if the arm moves at 15 R. P. S. This would mean twenty one new sets 15 of radial lines added to the image, equalling if Ynot'exceeding the luminous streaks of the pinhole spiral disk. All of the illumination of all of the lamps is more constantly in use in contradistinction toV the innitesimally small fraction '20 used in other methods. A thin metal disk with stamped ridges on its surface is desired, as such are much cheaper than the more elaborate commutators. They can be stamped by the thousands at very small cost.

25 Instead of the glow lamps of any type, incandescent lamps may be used if desired. Attention is directed to the type of neon tube which is illuminated by being placed in contact with but one electrode carryingra high frequency current.

30 Their cost is Very small. TheV invention, of

course, includes any form of lamp or tube. Tubes with a single pair of internal electrodes, or a large/single tube with many pairs of electrodes may be used. v 35.? Y Having described my invention, I claim as new land desire to secure by Letters Patent:

1. A combined television transmitter and receiver consisting of a motor, optical means for forming an image, a rotatable element in the 40 plane of said image operatively connected to said motor to be rotated thereby,'a group of photoelectric cells and a group of glow lamps carried on said rotatable element and being rotatable in said image plane thereby, said image plane be- 45- ing ofthe order of magnitude of said rotatable element, a transmitting conductorfconnected to one terminal of each of said photoelectric cells,

a receiving conductor connected to one terminal of each of said lamps, a plurality of contact 0 brushes connected oneto each of said photoelectric cells and said lamps, a commutator capable of making contact with but one of said brushes at a time, a transmission circuit connected to said transmitting conductor and to said commutator and a receiving circuit connected to Said receiving conductor and to said commutator in order that said photoelectric cells shall be inter- 5 mittently connected to said transmission circuit and that said lamps shall be alternately connected to said receiving circuit that images may be transmitted and received in the same image area. V 2. A two-way television apparatus consisting oi optical means Yfor forming an image, a rotatable element within the plane of said image and substantially coextensive therewith, a group of photo electric cells and a group of light sources borne on said rotatable element and so arranged thereon as to describe a plurality of paths coextensive with said image plane, said image plane being of the same order of magnitude as said rotatable element, means for consecutively and independently collecting the image varied current produced in said photoelectric cells, means for consecutively and independently supplying a f second image varied current to said light sources in order that an image may be transmitted and received in the same image area. and means for rotating said rotatable element within said image plane.

3. A two-way colored television apparatus consisting of means for forming an image, a rotatable element within the plane of said image and substantially coextensive therewith, a group of photoelectric cells and a group of light sources borne on said rotatable element and so arranged thereon as to describe a plurality of paths coeX- tensive with said image plane, said image plane being of the same order of magnitude as said rotatable element, certain of said photoelectric cells being sensitive to light of a speciiic color and certain others of said -cells being sensitive to light of another color, certain of said light sources emitting light of a specific rcolor and certain others of said sources emitting light of another color, means for independently collecting the image varied light produced in said photoelectric cells, means for consecutively supplying a second image varied current to ,said light sources in `order that an image may be transmitted and received in the same image area and means for rotating said rotatable element Within the said image plane.

ALOYSIUS J. CAWLEY.

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