US2089155A - Scanning device and method - Google Patents

Description

3, 1937 G. w. WALTON 2,089,155

SCANNING DEVICE AND METHOD I Filed Oct. 19, 1929 Patented Aug. 3, 1937 g nuns!) STATES PATENT OFFICE 2,089,155 some nvronann mimob. George wllliam walton, London, England, as

signor to Scophony Limited. London, England, a company of Great Britain Application October 19, 1929, Serial No. 400,883

In Great Brltaln October a, 1828 .17 Claims. (cans-is) This invention relates to apparatus for talevision, iacsimile telegraphy and for recording and reproducing pictures whereby the elements composing'the scene, image or picture are formed 5- or arranged in a novel and convenient manner. The human eye, because of its construction,

appreciates scenes or pictures as a two dimen-' slonal arrangement and hitherto all optical, tele vision, picture transmitting, recording and re- -l producing apparatus have been, constructed to formv two dimensional images and pictures. 'lhough an image or picture as presented to the,

4 mental areas, the detail within each of which is immaterial and the number of such elemental areas necmsary to give the desired effect being dependent upon the degree of definition required. 25 In a normal picture these elemental areas are, of course, arranged in two dimensions. The present invention may be regarded broadly as concerned with the productionfrom anormal two dimensional image or the like an image,

so referred to for convenience as a one dimensional image, which is representative of the two dimensional image but in which representations of all the elemental areas of the two dimensional image are simultaneously disposed so that they- 35 .do not overlap one another. Thus the nature of the one dimensional image is such that all the elemental areas representative of the two dimensional image can be scanned in succession by sweeping the one dimensional image once, 40 and in one diiection,.over a scanning aperture. The invention is also concerned with the reform ing of normal two dimensional images from such one dimensional images.

1/" The television and picture reproducing appathey are only given in order that the invention may be easily understood.

55 Fig. 1 shows diagrammatically a two dimennow more particularly sional image illustrating the me hod employed to transform it into a one dimensional image.

Fig. 2 is a diagrammatic representation of a one dimensional imageresultingfrom the transformation oi the two dimensional image shown 5 i 111 Fig- 1. w

Figs, 3 and} are views in side elevation and plan respectively of a reflecting echelon device for transforming a two dimensional image into a one dimensional image. or vice versa.

Figs. 51 and 8 are views in side elevation and plan respectively of a retracting echelon device.

Figs. 7 and 8 are similar views of a modified form of retracting echelon. device.

Figs. 9 and 10 are similar views of a modified 15. form of stepped refracting echelon device.

Figs. 11 and 12 are diagrammatic views showing the way in which records of animated scenes may be obtained Fig. 13 is a diagrammatic view oi a television apparatus using scanning, and i Fig. 14 is a view in side elevation thereof.

Referring particularly to Figs. 1 and 2, Fig. 1 shows a two dimensional image. picture, scene or representation, which is desired to transform into a one dimensional type. During the transformation, the picture is divided into any number of strips 0-2: to g-h the width and number ,of strips being decided by the degree of definition required. The number of strips into which the'image is divided in the drawingiis purposely made very small for the sake of clearness of illustration. In practice the width of the strips (the vertical dimension of the strips in the drawing) is made equal to the width of the elemental areas into which the picture can be assumed to be divided to give .the desired degree of definition. Each strip can therefore be regarded as a single row of elemental areas. After such sub-division all points lying on a line :c-a: across a width can 40 be represented by the-line x:|: having an intensity which may be uniform or not so long as it is the average of the intensities of all points ins, and therefore each strip only requires definition in its length (that is, horizontally in the drawing). If the strips 0-17 to g-h are deployed as in Fig. 2, then as long as there is definition within the length a to h the image of Fig. 2 is equivalent to Fig. l, for practical purposes, as it contains all the elements of Fig. 1. Fig. 2 can be regarded as a one dimensional arrange- .ment of Fig. l which is two dimensional, and in this arrangement :r-a: may be vanishingly short or infinitely long without affecting the efllcacy of Fig. 2 as a picture or image.

2 s,osc,1ss

Fig, 3 the vertical faces are mirrors. In Fig. 4 a

pencil of light p having a depth covering all the reflecting surfaces, is thrown on. to those surfaces at an angle, a section of the 'incident pencil being reflected by each surface. As each successive surface is further away than the preceding one, the sections of the pencil are reflected with lateral displacement, which by suitable size,

of steps, angle of incidence and width of pencil can be such that the reflected sections a", e, c,

do not overlap, so that if the cross section of the incident pencil is represented by Fig. 1, the cross section of the reflected light will be represented 2o by Fig. 2.

With the type of reflector shown in Figs. 3 and 4, the length of the light travel is diflerent for each step of the reflector, but this may be remedied by successive reflection from two or more 5 stepped surfaces so arranged that the lateral displacements of the successive surfaces are preferably additive.

j Fig. 5 shows a retracting echelon; being a side view and Fig. 6 a plan view, as in Figs. 3 and}.

Light passing through the steps is laterally displaced by amounts dependent on the thickness of material traversed, so that the issuing sections a, e", c, of the entering pencil p are deployed,

as in Fig. 2. Refraction may take place in one or more stages, with the displacement of the suc .v

cesive stages additive, and further the stages may be arranged so that the length of path through the system is constant at all points, thereby facilltating'the focussing of'an image;

40 Fig. '1 shows another form of echelon refractor,

in side elevation, and Fig. 8 a" view in plan there'- of. This consists .of prisms of increasing angles, each step giving a different angle of deviation.

7 which if arranged in increasing order arrange the issuing light sections. as in Fig. 2.

Fig. 9 shows another stepped refractor in front elevation and Fig. 10 a view in plan thereof.

The steps are lenticular in shape and staggered preferably in a direction at" right angles to the 60 optical axis of the system. An-object or image at o,- similar to Figure 1, is focused in a vertical direction (perpendicular to the paper in Figure I 10) at or near the entrant'surface of the echelon device I! by a cylindrical lens ll.- 'Ihuseach lens of the echelon receives light from only one horizontal strip of the obiectmnd deployed line images of horizontal strips of object o are formed at a, e, 0*. etc., these line images being focusedby the echelon lenses only in a horisontal dlrec-.

tion. It will be understood bythoseskllled in the art thatinthe caseofl 'lgures 3 to Balsa-suitable optical means are provided the one dimensional image is focused es parallel tothe plane of-thepaperinl'igur'esi and 8 and that animsge isfocused. at least-in a direction perpendicular to' that of deployment,

in or about the entrant surface of an echelon device, .so that each step or lamina deals only be dennite stepsinthe device-having linear or,

- fl angular displacement preferas a cinematograph ,fllm. If the pictures 04! to to insure that" p in the di-'- rectionof deployment. thatis to say. in planes ably, but not essentially. of "some regular order of displacement.

Ihe'line image of Fig. 2 is of great practical utility, as by its use very compact records can be made of scenes or pictures, and, further, it is 8 even. greater value in recording changing scenes.

"in that a truly continuous record may be made in contrast to the ordinary cinematograph record which is intermittent. The manner in-which v this is accomplished is shown-in Figs. 11 and 11' 10 In Fig. ,11 i is the record material. such as photographic fllm plate or paper. on which a line image is formed by an echelon device in combination with a suitable lens system. Any conven- ,ient system of reels, rollers and guides may be 15 provided to accommodate and traverse-the record material i over the line image. Thus, the record material can be moved in the plane of the line imaged, e, I, Figure 10 for example. in a direction perpendicular to the plane of the paper. If i moves upwards a number of line pictures 0-12 to 0-1:. may be impressed intermittently, in which casethe record would be much the same y-h are impressed successively without any movement of the scene or point in the scene, and the, position and aspect/of the apparatus relative to the scene is kept constant, then a point or elemental area It will appear in each picture in the 'same relative position, and as i moves upward the points It in each picture will lie in a line parallel to the direction of movement of i. The record material i need'not move intermittently not need the picture he exposed'intermittently, for i a can be given a movement preferably constant and along a straight line, and the point b will.

trace a line on the record, the intensity ofthe impression at any point of that line being proportional to the intensity -k at some particular a moment; Such a line is obviously a continuum true record of the point l: and of that point only. The same also applies to every point in the line image.

Fig. 12 shows such a record, the sections a, u c, e, and a being sections of the image, that is individual lines of the original two dimension image orsceneshownaso-btoc-hinl'ig. Land for. a'condition of no movement in scene or app'aratus the points'in each section will trace a so number-of parallel lines, ss-shown in section I. only. Should a point in the scene move, say horisontally in Fig. 1, then during such movement, that point combinedzwith the steady movementoftherecord.wllltracea linewhiehisno ll longer parallel to the direction of movement of the record.. Assumingrectilinear direction a constant speed of record, a point moving hori- -s-'-s, in Fig. 12,-end another horisontally in an-opposite direction at a decreasingspeed will trace a curves-sh Apoint moving vertically'downwardsinng. l at aconstant M will move from one line to-another in succession 05' d will, therefore, appear successively in ode iac'ent sections a, c; c. 9 of Fig. 12 as the short lines uncut, and it. which will lie in straightlineintherecordandbealiofthe same length. 4

Another point moving vertically upward at an ihcreasing speed will" appear-as the lines m'. 1t", t', and u, which lie in a curve, as longest and the others of successively shorter {lengtlm Any other direction-of movement of 7" a point in the scene will be recordedas a compound of vertical and horizontal movements.

Within the limit of definition imposed by the number of lines into which a scene may be divided, that is the number of sections, such as axe, e of Fig. 12, and that definition which the recording surface can satisfactorily accommodate, every point of the scene maybe moving individually in different "directions and paths,

rectilinearcurved or irregular, and at wholly different speeds increasing; decreasing, constant or irregular, and each point will simultaneously trace on the record a characteristic and individual pattern, and yet the different patterns" will inrno way interfere with .each other, for.

should a line cross another on the record for instance, H, and s's', Fig. 12, the point of crossing isa record at the moment when one point is obscured by the other in the scene being recorded.

A picture record as described may be said to record the position of a point in a scene in onedimension of the record and the other dimension corresponds to time, the whole recording change of position in time. It is preferable that the line image being recorded should be very narrow in the direction -:r-:c of Fig. 2 in order to improve the quality of the record and also to shorten it,

metres per second. In contrast with the ordi-.

nary cinematograph film using one foot per second, there isgreat advantage and also apparatus for intermittent movement and exposure is 1 not required.

In order thatthe record shall be of'aconvenient width. one dimension of the image may bereduced relative to the other and preferably the horizontal dimension of Fig. 1 which correspondingly reduces the length oi Fig. 2. The limit to this reduction will he the ability of the surface to record the definition required which E the size of the grain of the emulsion if a record is used. This reduction is of advantage in television apparatus.

a natural colour record that is one multiple record any three cofour, can be made, and would consist of records sideby side on the same.

surface. pting for the fact that the retwo dimensional image, the recording and re- 1' methods and apparatus may be the e as'in known natural colour recording and reu.

In reinga picture record of the kind ahown in Fig. 12 by projection, devices similar,

' to then described in connectionwith Figs. 3 to 10 may be used inversely, the record being traversed and suitably illuminated so that a re'constructed two dimensional picture will be thrown on a screen disto receive it. I

As described, the picture record is in the form ot a strip but this is by no means r'recessaryforv it may take the form of a disc similar to a gramophone record, again that of a. cylinder or any other forin which aiiords a surface on which a line image can be impressed whilst that surface is given a cuitable traversing motion as described image is a one dimensional instead of a j with reference-to Fig. 12.] The record may be transparent or opaque. and during reproduction may be illuminated by'light passing through the record and on to the optical system, or by light which is reflected by the record on to the optical 5 system.

The line image and the echelon devices may also be used in systems of television, facsimile telegraphy and the like, in which scanning is employed. The one dimensional image is preferably scanned, in which .case the scanriing device may be very simple and compact. Any of the known means of optical scanning may be employed, or a mechanically oscillated photo-electric cell.

Whichever are used, they are very much simplified as only one dimensional scanning is required. In facsimile telegraphy, it is preferred that a one dimensional picture be made, for instance, on strip photographic film, which is then traversed between a source of light and a light-sensitive-device. Since a one dimensional image .isboth transmitted and received, no iheans of synchronization are required for traverse may be at any rate at both transmitterand receiver and -independent This will be readily appreciated from the fact that a one dimensional picture is the same as an ordinary picture in that it can be enlarged or reduced without losing any of its value as a picture. vIn the receiving instrument,

a 'photographically sensitive tape is traversed at any convenient speed through a ray of light, the

intensity of which is electrically controlled by the transmitted impulses. The line picture so received may at any time-be readily converted into a two dimensional image by means of the echelon device, made. l

' A preferred arrangement of television apparatus using scanning consists of a mirror oscillated and a two dimensionalpicture by an electromagnet having a make and break 40 contact, similar to the type used in electric bells and buzzers.

The arrangement is shown in Fig. 13 in which 20 is a lenssystem, iii the echelon device which forms-a line image at 22, the light from the image being converged by lenses '23 and- 4 23'- on to the mirror 24, oscillated by electromagnet 26 which is supplied with interrupted electric current by a contact maker 28. Light reflected by mirror 24 is reflected on to a light sensitive'cell 21, Fig. 14, before which is placed a step 28 which has a slit of suitable width in it.

By means of-the oscillating mirror, points in the line image are reflected in regular succession onto the light sensitive cell. The receiver may be the same, except that the cell zl'is replaced by a source of, light and an electrical means of con-' .trolling the intensity of'light thrown on to the mirror, or a neon or arlamp may be used in thewell known in Thefrequency of the mirror oscillations maybe controlled by mechanical tuning of the vibrating mec,

- as varying the spring tension thereby forming a simple means of synchronization between transmitter and receiver.

.The expression "static displacement", or "static Bptical displacement in the claims, means such displacement or deployment as can be produced without motion of the optical device. Subject matter disclosed'but not claimed herein '0 is claimed in the following applications comprising divisions hereof: application Serial No. 37,584, filed August 23, 1935, Motion picture records, and application Serial No. 115,048, filed December 9, 1938, improvements in Picture representation and improvements in television and in the cording and reproducing of pictures.

. I declare that what I claim and desire .to secure by Letters Patent is:-

1. In a picture reproduction system, means for forming, from an object, an image composed of 4 line elements of the object deployed so that they do not overlap one another, for use in television, picture recording and reproduction and like pur-' poses, said apparatus includingan optical sys- 'tem comprising refractively acting transparent. laminae arranged in staggered formation, each of said laminae having a plane edge surface, said plane surfaces of all laminae lying in the same plane, with the opposite edge surface of each laminae so arranged as to effect deployment.

2. Apparatus adapted to deploy a picture into the form of non-overlapping line elements for use in television, picture recording and reproduction and like purposes having an optical system comprising refractively acting transparent I laminae, the planes of said laminae being parallel to the axis of said system, each of said laminae being in the form of a cylindrical lens having its axis .of curvature substantially perpendicular to.

the said planes and said laminae being staggered relatively to one another in a direction substanan optical system comprising a plurality of retially perpendicular tosaid axis. I 1 3. Apparatus for television, picture recording and reproduction andthe like purposes having fractively acting transparent laminae arranged contiguously and with one of their axes staggered in a single plane, said laminae being in the form of like cylindrical lenses arranged with their axes of curvature co-planar and displaced 5. In a picture reproduction system, optical means adapted to form from an object an image in which the representations of adjacent lines of said object are longitudinally displaced relatively to one-another, 'saidopticalmeans inclu'd- .ing a stationarytransparent ,solid refracting.

echelon device having a plurality of entrant type surfaces to which light from said object can enter said deviceand, associated with each of said entrant surfaces, an emergent type surface through which the lghtcan emerge'aiter refraction, one of said types of surfaces lying in diflerent planes, and the surfaces of the other of said type of surfaces being in by common lines. U

' 6. Ina picture reproduction system, opticalthe same plane and bounded vmeans'adapted to form from an obiectan image in which the representations said object are longitudinally of adjacent lines oi.

to one another, said optical means including astationary solid transparent retracting echelon device having a plurality of entrant surfaces at -'which light frcmsaid object can enter said de" vice and.associated faces,. an emergent surface through which said. light can emerge afterrefraction, each-of i placed relatively with each of said entran't'surv Y entrant and emergent surfaces lying in a dii1ierent plane, and said entrant surfaces being in the same plane and bounded by common lines.

7. In a picture reproduction system, including optical means for viewing an object, said optical means comprising a plurality of stationary optical elements positioned and constituted to view different parts of said object and to simultaneously ,produce contiguous parallel line images having detail only along the line of said parts'which are deployed to such an extent that they do not over? lap one anotherviewed at least in a direction normal .to the direction of said deployment, an

mission, and means for formingsaid deployed line-images in the neighborhood of said device.

8.-Apparatus for picture repr uction' including optical means for viewing,

optical means comprisi g a plurality of optical elements positioned and constituted toviewdiffere'nt parts of said object and to simultaneously produce contiguous parallel line images having definition only along the line of said parts which are deployed to such an extent that they do not overlap one another viewed at least in a direction normal to the direction of said deployment, an apertured photo-sensitive device, means additional to said optical means for producing relative motion between said deployed line images and said device and means for deriving from said device'electrical signal for transmission.

.9. In a picture repr of producing an image of a picture in which image allp'ictureelements composing the picture are arranged in a row, comprising forming images of lines of picture elements and producing static optical displacement of said images rela-' tive to one another in the direction of said lines, said images having definition only in the direction of said displacement.

10. In a picture reproduction system, means for 4 forming an image ofvan object, and means in-' cluding a plurality of stationary optical elements for distributing the light from-the object in such a manner as to deploy the image laterally in a series'of non-overlapping line areas having detail only along the line, and movable means for sweeping the lines successively across a predetermined ture are arrangedin a'ro'w and have definition at least in the direction of said lines, a second image in which ,the lines of picture elements are arranged one beneath the other as in the original.

picture, a plurality of cylindrical lenses positioned and constituted zto statically dgploy the image laterallyin a series of non-overla ping line areas.

Apparatus for forming, from an object. a image composed of non-overlapping deployed line elements for use in television, picture recordq n object, said uction system, the method 35 picture reproduction system for forming and reproduction and like purposes having an optical system 'comprisi'ng an optical device con-l. sisting of a plurality of optical laminae, the

planes of thelaminae being parallel to the axis of the system and the laminae being arranged .con-' tiguously and i staggered formation. eachyof 'said laminae ng in the form of a cylindrial lens having its axis of curvature substantially to the said planes and said p pe d a mosaics being staggered relatively to one another in a direction substantially perpendicular to said axis, and a lens means associated optically with'said device having optical power at least in a plane 5 perpendicular to the planes of said laminae.

13. A systegi of reproducing pictures comprising successiv y viewingdisplaced portions of a moving line of modulated light and statically optically displacing successive portions of differ 10 ent positions of the line to position such portions 'in the same line. f

14. In a'picture reproduction system,means for developing a line of light, means for moving said line at right angles to itself, and static optical 15 means for placing difierent portions of difierent lines of the light in a single line on a viewing screen. 15. A system'of reproducing pictures comprising successively viewing displaced portions oi.- a 20 moving line of modulated light having definition only in the direction'of displacement and statically optically displacing successive portions 01 different positions of the line to position such portions in the same line.

16. In a picture reproduction system, means for developing a line of light having definition only along its length, means for moving saidvline at right angles to itself, and static optical means for placing diflerent portions of difierent lines of the light in a single line on a. viewing screen.

17. The method of reproducing pictures comprising producing picture modulated light, arranging the lines of the picture in laterally displaced rows and refractively acting on the displaced rows to arrange the picture in a series of lines which are contiguous to each other and the ends of which are bounded by the same

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