US1778674A - Apparatus eor transmitting pictures - Google Patents

Description

Oct. 14, 1930. R. D. KELL 1,778,674

APPARATUS FOR TRANSMITTING PICTURES Filed May 29, 1928 "Fig.1.

42 ZsERIES MOTOR $1 Inventor: If, W Rag D. Ke LL,

9 H i s Attorney.

Patented Oct. 14, 1930 RAY I). KELL, on storm, NEW YORK, Assreivon TO A CORPORATION on NEW GENERAL ELECTRIC COMPANY, YORK APPARATUS FOR TRANSMITTING PICTURES Application filed May 29',

My invention relates to apparatus for transmitting pictures, and has for its principal object the provision of an improved apparatus and method of operation which may be readily utilized to establish synchronism between the picture receiving and transmit-. ting apparatus and to frame the picture at the receiving apparatus. A

In the transmission of pictures, it is essential that means be provided for successively scanning the elemental areas of the picture, for establishing and maintaining synchronism between the moving parts of the transmitting and receiving apparatus,

and for producing electrical impulses which are proportional to the intensity or color of the light emitted by the successive elemental areas of the picture.-

In order that the picture may be properly framed at the receiving apparatus, it is also essential not only that the synchronism be established between the moving parts of the transmitting and receiving apparatus but also that a certain definite mechanical or angular relation be established between these moving parts. Many of the means heretofore provided for establishing this relation have not been altogether satisfactory because they involve the making of diificult adjustments and are not readily operated.

In accordance with my invention, these difficulties are avoided by the provision of an electro-responsive element which may be readily operated to lock the moving parts of the receiving and transmitting apparatus into synchronism with one another and to thereafter adjust the mechanical relation between these moving parts.

My invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope will be pointed out in the appended claims.

Referring to the drawings, Fig. 1 illustrates a picture receiving apparatus wherein my in- 1928. Serial No. 281,486.

vention has been embodied; and Fig. 2il1ustrates a picture transmitting system including the apparatus illustrated by Fig. 1.

This apparatus includes a scanning disk 1 which is mechanically coupled to a driving motor 2 of the alternating current series type and is provided with spirally arranged openings 3. Modulated light impulses from a source shown as a lamp 4 are applied through the openings 3 to a lens 6 mounted in the wall of a casing 7 wherein the apparatus is mounted. The synchronizing and framing of the picture is effected by. means of an electro-responsive device which includes a magnetic member or synchronizing rotor 8 mounted on the scanning disk 1 and an electro-magnet 9 arranged to be rotated by a knob 10 to which it is connected through a bearing in the wall of the-casing 7. It will be observed that the member 8 is provided with a plu rality of projections or pole pieces 11, that the motor 2 is connected to suitable current supply means 12 through leads 13 and a switch 14, and that the electro-magnet 9 is connected to the current supply means 12 through leads 15 and a switch 16.

he lamp 4 is connected to a radio receiver 17 which is arranged to supply electrical impulses modulated in accordance with the light reflected from a picture 18. As will be apparent without detailed explanation, the apparatus for transmitting these impulses includes a scanning disk 19 arranged'to be driven by the'synchronous motor 20 and provided with spirally arranged openings. Light from a suitable source 21 is applied to the picture 18 through a lens 22 and the openings of the disk 19, and the light im pulses reflected from the picture and dependent on the shade of the picture are received by the light sensitive cells 23 through which they are converted into electrical impulses and applied to a radio transmitter 24. The operation of the synchronizing and framing device will be readily understood if it be assumed that'thel motor 20 is operating and the motors 2 and 20 are arranged to be energized from the same current supply line 5 or from current supply lines operating at the same frequency. In order to synchronize the disks 1 and 19, the motor 2 is connected to the line 12. When the picture appears undistorted at the lens 6, the electromagnet ing the picture in position. If the transmitting and receiving disks are not in the same phase position, however, the received picture will appear out of frame. This is corrected properly ramed.

In the practical utilization of the invention, it has been found that'six poles on the synchronizing rotor 8 are satisfactory for go the production of a 24 line picture repeated 9 is connected to the supply line 12, thus lockby turnin the knob 10 until the picture is connected with said circuit, and a synchroniz-' ing and framing device for the disk of the windin connected with said circuit.

In witness whereof, I have hereunto set my hand this 28th day of May, 1928.

. RAY D. KELL.

twenty times per second. A picture having a larger num er of lines may of course be run at a lower speed without excessive flicker.

25, The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent,

however, that the invention is susceptible of so being modified to meet the difl'erent conditions encountered in its use and I therefore aim to cover by the appended claims alh modifications within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. Picture receiving apparatus comprising a rotatable disk having a series of light openings therein, an alternating current power supply circuit, a driving motor for said disk connected with said circuit and a synchronizing and framing device for said disk comprising cooperating magnetic members, one of said members being rotatable with said disk and the other of said members being angularly adjustable and having a winding connected with said circuit.

2. Picturereceiving apparatus comprising a rotatable disk having a series of light openings therein, an alternating current power supply circuit, an alternating current series motor for driving the disk connected with said circuit, a synchronizing and framing device for the disk comprising a toothed magnetic member secured directly to said disk and a cooperating'adjustable magnet having a winding connected with said circuit, a casing enclosing said apparatus and an adjusting member for said magnet projecting through said casing.

3. The combination with an alternating current power circuit of picture transmitting and receiving apparatus, each apparatus including a rotatable scanning disk and an alternating current driving motor therefor

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