US1806638A

US1806638A - Television

Info

Publication number: US1806638A
Authority: US
Priority date: 1928-07-24
Publication date: 1931-05-26
Anticipated expiration: 1948-05-26
Also published as: GB316185A; USRE20239E

Description

May 26, 1931.. MERTZ 1,806,638

' TELEVISION Filed July 24, 1928 IN VENTOI? HERRE MEET;

I ATTORNEY I Patented May 26, 1931 UNITED STATES PATENT OFFICE PIERRE mm, 01 IBELLEBDSE MANOR, NEW YORK, ASSIGNOR TO AMERICAN TELE- PHONE AND TELEGRAPH COMPANY, A CORPORATION 01' NEW YORK TELEVISION Application 11101! July 84, 1928. Seriallfo. 895,098.

This invention relates to electro-optical systems and more particularly to television. The principal object of this invention is Y to improve the resolution in electro-optical 5 image producing s stems.

In accordance with the invention, this object is in general accomplished by moving the image elements from one scanning to the next to cause overlapping. The distor- 1 ning. Consequently, if the eye viewing the image averages the impression from several successive scannings, the distortion visible to it is in general less than if the elements should remain fixed from scanning to scanning.

2o In a'specific arrangement,.which is illustrative of the invention, the scanning discs at both the transmitter and the receiverof a television system such, for example, as the system disclosed in an ap lication of H. E.

Ives and Frank Gray, erial No. 181,511, filed April 6, 1927, are each provided with two sets of spirally arranged apertures, one set on each half of the disc. One set is adapted to scan an image field in a plurality of adjacent elemental'line traces. Theother set then scans the same field also in a plurality of line traces but each of these traces overlaps-ad'acent portions of two adjacent traces scanne b the first set. Thus, for each revolution o the scanning disc, two successive scannings are accomplished and the image elements are moved from one seaming to the next.

This invention is not limited to television systems but is usable wherever optical images are produced by multiple exposures of an image field by the exposure of elemental areas thereof.

The invention will now be described more in detail, having reference to the accompanyin drawings.

igure 1 shows schematically a television Fig. 2 is a scanning disc for use in the sys- 60 tom of Fig. 1, and Flg. 3 is a schematic diagram showing the relation of the lines scanned by the two sets of apertures shown in Fig. 2. Y

In the system of Fig. 1 the television transmitter T is associated with a cooperating receive'r R by a transmission channel such as the line L. Reference may be had to the aplication of Messrs. Ives and Gray supra, for

urther details of equipment suitable for use in the system of Fig. 1, with the exception of the scanning disc, details of which are shown in Fig. 2.

As the scanning discs rotate, elemental lines of the image field are scanned in succession. A complete scanning as herein used is one in which the scanning path pattern is complete.

In systems heretofore known, complete scannings have covered either identical elemental areas or non-overlapping elemental areas. In the present invention, as observa tion of Figs. 2 and 3 discloses, the paths of complete scannings partially overlap.

In the disc 5 of Fig. 2 only five apertures are shown to effect a complete scanmng. In actual practice, a larger number of apertures is in general used, the smaller number being shown herein for purpose of simplification. Apertures 6 to 10 produce one complete scanning during a half revolution of the disc 5 while apertures 11 to 15 roduce another scanning during the next hal revolution. As shown by the dotted lines, aperture 11 follows a path partially overlapping the paths followed by apertures 6 and 7. Overlapping of the paths likewise occurs for the other apertures. The relation of these overlapping paths is shown in Fig. 3. The

numbers

11, 12, 13, 14 and 15 represent paths which partially overlap the paths represented by the dotted lines and numbers directly opposite; for example, path 12 overlaps portions of paths 11, 8, and 7, represented by the three dotted lines opposite these numbers.

A further improvement in resolution of the produced image may be effected by providing more than'two sets of a ertures for the disc 5. It is then necessary t at the positionsof the paths for successive scannings 100 of two. lines of the trace of t be in some irregular order, as a regular order might cause an apparent motion of the picture elements in the viewing field which would be annoying. The extent to which improvement can be effected in thls manner will depend upon the number of successive scannings over which the average is taken by the eye in determinin its impression.

The invention is, 0 course, not limited to the articular arrangement described in detail ut is defined by the scope of the appended claims.

What is claimed is:

1. The method of scanning to produce image'currents which comprises repeatedly scanning the entire area of a field of view and causing each scanning line of the entire path of one complete scannin to partially overlap two scanning lines o a preceding one. I

2. The method of scanning to produce image currents which comprises repeatedly scanning the entire area of a field of view and cyclically shifting the scanning path between complete scannings so that each scanning line of a complete path partially overlaps two scanning lmes of a preceding one.

3. In an electro-optical system means to repeatedly scan the entire area oi a field of view along line series of elemental areas thereof, comprising means for causin each scanning to traverse a trace each hne of which overlaps simultaneously portions only e preceding scanning.

4. In an electro-optical system means to repeatedly scan the entire area of a field of view along line series of elemental areas thereof, comprising means for causing each scanning to traverse a trace each hne of which overlaps simultaneously .at least onehalf of each of two adjacent lines of the trace of the preceding scanning.

5. In an electro-optical system, means for repeatedly successively scanning contiguous line series of elemental areas of the entire area of a field of view, said means c o mprising a scanning member having a plurality of setsof scanning apertures so placed that each line scanned by one set overlaps substantially half of two lines scanned by another set.

6. In an image producing system, a scanning disc, a set of a of said disc arrange to scan the entire area of an ignage field in a plurality of elemental lines as the disc rotates, and a second set of apertures on-another portion of said disc arranged to scan the entire area of the same image field and radially displaced with respect to the first set of apertures by a substantial portion of the diameter of the aper- 7 one set of tures so that each line scanned by f f al 0 two apertures overlaps substantially lines scanned by the other set.

7. The method of scanning to produce of said disc arran e field, and causing each km of the entire rtures on one portion image currents which comprises scanning the entire area of a field of view, and a ain scanning substantially the entire area 0 said field of view in such a manner that each line traced by the second scanning overlaps porti 0ns of two lines traced by the first scanning.

' 8. The method of scanning to produce image currents which comprises repeatedly completely scanning with overlapping lines, the entire area of a field of view, and cyclicall shifting the scanning path after each comp ete scanning so that each line of a succeeding scanning overlaps portions of two lines overlapped in the previous scanning.

9. In an electro-optical system, means for repeatedly successively scanning contiguous line series of elemental areas of the entire area of a field of view, said means comprising a scanning member having a set of scanning a rtures so placed that the line scanned by eac aperture is artially overlapped by the line scanned by t e next succeeding aperture, and having an additional set of scanning apertures so placed that the line scanned by each of these apertures partially overlaps two of the overlapped lines scanned by the first mentioned set of scanning apertures.

10. In an image producing system, a scanning disc, aset of a ertures on one ortion to scan as the iso rotates an'image fiel in a plurality of elemental lines, each one of which partially overlaps thepreceding line, and a second set of apertures on another portion of said disc arranged'to scan the same image field and radially displaced with respect to the first set of apertures b a substantial portion of the diameter of t e apertures so that the line traced by each of these apertures overlaps portions of the overlapped lines of the first mentioned set of apertures. I

11. The method of scanning to produce image currents which comprises repeatedly completely scanning the entire area of a field of view, the traces produced by each complete scanning completely covering thls at of one complete scanning to only parti all overlap two lines of the path of the preced ing scannin j 12. The method of scanning'to produce image currents which comprises scanning the entire area of a field of view by causing each scanning line to partially overlap that of a preceding one, and again scanning substantially the entire area of said field of view by lines which overlap each other and also overlap portions of lines overlapped in the first scann ng.

In testimony whereof, I have signed my name to this specification this 6th day of July, 1928.

PIERRE MERTZ.