US1817098A - Colored facsimile system - Google Patents

Description

Aug. 4, 1931. R. H. RANGER ET AL 1,817,098

COLORED FACSIMILE sYsTEM Filed March l. 1929 .W/YE SHAFT ARS mgl/gian lvwwozs mman HowLANvRANaeR SAMUEL sMlTH Patented Aug. 4, 1931 UNITED STATES PATENT OFFICE` RICHARD HOWLAND RANGER, OF NEWARK, NEW JERSEY, AND SAMUEL B. SMITH, 0F

BROOKLYN, NEW YORK, ASSIGNORS T0 RADIO CORPORATION 0F AMERICA, A COR- PORATION 0F DELAWARE COLORED FACSIMILE SYSTEM Application led March 1,

The present invention relates to the transmission of facsiiniles and the like over wire, wired radio or radio communication lines and is particularly concerned with the transmission of these pictures so that they may be received in their natural colors without the need of resorting to manual coloring processes or receiving the same picture several times in order to color the same in a manucr closely approximating an original.

By the terni pictures we, of course, wish to include all printed mattei', such as, documents, checks, financial statements, newspaper sheets, fashion plates and the like and also all views in colors, colored etchiiigs and the like and the term picture as used throughout the following specification should be considered in a generic and not in a limiting sense. p

It has been known in the art to which .the present invention relates that it is possible to reproduce transmitted pictures in colors at the receiver by successively transmitting the picture several different times while using a different color screen at thetransnitter for each transmission, so as to mark a recording paper according to the particular color tone intensity on the original picture, but such systems are not without o blection in that the difficulties of synchronizing and exactly matching the various spots of the received picture with those of the transinitted picture are inherent and cannot be conveniently avoided.

According to the present invention we have provided a novel method and means whereby it is possible to produce at. the receiver pictures directly from incoming signal pulses in colors closely blending with and approximating the colors on the original transmitted picture, in a manner to be hereinafter described. l

Therefore, an object of our invention 1s to provide a novel method and apparatus for receiving by a single operation, pictures ytransmitted from a distant point by a single transmission operation, in colors closely approximatingI the original transmitted picture. l t

Another object of our invention is to pro- 1929. Serial N0. 843,768.

vide a colored picture at the receiver which is composed of all the various shades and tones of colors in the visual spectrum while using only a single channel of communication for all colors, although, where it is desired, we may use a multiplex system and a plurality of communication channels.

Still another object of our vinvention is to provide in connection with a picture receiving system a novel means for applying various color fluids or inksl to a recording surface for producing the received picture.

Still another 'object of our invention is to provide a novel method and Vapparatus whereby the various colors applied to the picture recording surface may be applied at spaced time intervals, if desired, or, at adjacent time intervals, if desired.

Still another object of our invention is to provide a method and apparatus for receiving pictures at a receiving point in such a manner that adjacent lines of the recording surface are colored with only a single color marking fluid but are so arranged that the sequence of coloring, by use of the various color recording fluids or inks, is such as to produce a color blended received picture that closely corresponds to the colors on the original picture beingftransmitted.

Still another object of our invention is to provide a system and arrangement for continually changing the transmission and reception of the picture from one to another of the various primary colors used to produce blended colors covering the entire visible spectrum.

Still other objects of our invention are to provide a method and apparatus for tra-nsmitting and reproducing a picture in its natural colors which is simple in its construction and arrangement, a system which is compact, convenient to install, elicient in its operation, substantially fool-proof, and capable of producing the desired results with the minimum of in-stallation expense.

Still other and ancillary objects of our invention will at once suggest themselves to Athose skilled in the art to which the invention relates by a consideration of the following specification and claims, when read in connection with the accompanying drawings forming a part of our disclosure, wherein:

Fig. 1 illustrates a preferred form of transmitting apparatus;

Fig. 2 a suitable form of receiving arrange-l ment for cooperating with the transmitter of Fig. 1,'

Fig. 3 is a view of the line 3 3 of Fig. 1 looking in the direction of the arrows and illustrates a suitable means for driving a plurality of color screens or filters;

Fig. 4 illustrates conventionally one form of recording apparatus suitable for use in connection with our invention;

Fig. 5 illustrates conventionally, on an enlarged scale, the sequence of recording the various colors in a three color time separated recording action, and the manner of building up the received picture;

Fig. G represents a color disk formed from three primary colors which may be substituted for the three disks shown by Fig. 3;

Fig. 7 represents a system using two primary colors, and is a moi'lification of the arrangement shown by Figs. 1 and 3; and,

Fig. 8 illustrates a further modification ef the arrangement shown by Fig. 7 wherein a single disk provided with two primary colors is used.

Now making reference to the accompanying drawings, a picture carrying drum 1 supports a picture 3 which is to be transmitted. The drum 1 may be rotated in any preferred manner (not shown) and by means of the threaded shaft 5, associated with the drive means for turning the drum, is advanced longitudinally in a spiral or helical path before a scanning means for analyzing the varying tone intensities of the elemental areas of the picture 3.

In accordance with the embodiment of the invention herein illusti'ated we have shown as an illumination means for analyzing purposes a plurality of individual light sources 7 of the annular type surrounding tubular members 9 which contain scanning lens systems, (not herein shown but described and claimed in copending application of Richard Howland Ranger. Serial No. 321.821, filed November 26, 1928)` and the light from this source 7 is projected as a point source upon the picturt` surface 3 at a point which corresponds to the focus point of the lenses contained within the light tube members 9. The light tube members 9 are herein shown as separated by a predetermined amount which is equal in each case to the width of three successive lines of scanning on the transmitted picture. However, for a two color transmission system only two scanning lenses would be provided if spaced recording is desired. Also for successive line recording in either case only a single scanning lens system is needed, as will hereinafter be described.

Light from the picture surface is reflected through the lens systems contained within the tubular members 9 and is then projected backwardly'through the tubular members 9 to a lens member 11 from which it is projected through an adjustable diaphragm 13 to photoelectric members 15. The diaphragms 13 are adjustable with respect to the amount of opening in two directions by means of the thumb screws 17 in a manner disclosed inthe above named copending a plication of Richard Howland Ranger. uri-ents produced in the photo cells 15 by light reaching the same are then appropriately amplified in any desired manner by means of an amplifying system 19 and transmitted from a transmitter 21 and associated antenna system.4 23 if the invention is to be used for radio communication and if for a wire system a wire line would be substituted for the transmitting antenna.

It will be noted that the photoelectric cell members 15 are connected in parallel and enclosed within a light opaque housing 25 so as to prevent external light other than that rcflected from the picture surface from effecting any of the photoelectric elements.

The light sources 7 are preferably continually illuminated to avoid switching arrangement and, therefore, the reflected light from the picture surface is continually directed backwardly through the tubular members 9 to the lenses 11 so as to effect the photo cells. However, in order to distinguish as to the varying colors on the transmitted picture we have provided a plurality of color screens A, B, and C which are mounted on spindles through the sides of the housing 25 so as to rotate in the space between the ends of the light tube members 9 and the lenses 11. These color screens are all driven from a single shaft 27 which is in turn rotated through a gear reduction mechanism 29 from the same prime mover that turns the picture drum 1 and in the case where three color screens are provided as in the present invention the shaft 27 will turn at 1/3 of the speed of shaft 5.

As shown more particularly by Fig. 3 of the drawings gt, the color screens A, B, and C are each composed of 2st()o of black and 120 of red, blue, and yellow, respectively. The color screens A, B, and C composed respectively of red, blue, and yellow (which form the primary colors for a three color system) in a 1/3 ratio with respect to the black are so positioned on the shaft 27 that at periods when light from one of the tubes 9 is projected backwardly and is able to pass through the red portion of the disk A, for example, the light which is rejected backwardly through the other tubu ar members 9 will be shut off from the photo cells associated with each of these tubes by means of the black portion on the disks B and C. At such a period of time when the disk B is turned so that its blue portion comes before the tube 9, the other disks is thus seen that the photo cells 15 are suc cessively energized by either light passing through the red, blue or yellow portlons of the disksl A, B, and C.

It will, of course, be recognized that in case adjacent lines of the picture surface are to be recorded that only one light tubular member 9 and one illumination source7 will be re,y

quired 'for the purpose ofprojecting light from the picture surface to the photo cell, since there might then be only a single panchromatic photo cell 15 and a color screen revolving between the end of the tubular member 9 at photo cell. In this case the color screen would be driven at the same speed as shown in connection with F 1 except that instead of each screen being composed of 1A, red, blue, or yellow, and 2/3 black, the single screen would be 1/3 red, 1A; blue, and 1A, yellow with no black portions as shown by Fig. 6.

For convenience in recording and, also, in order to avoid substantiallyv the detrimental eects of the fading out of signals in transmission, it has been found desirable to space the lines of recording and thus avoid complete obliteration of portions of the received picture, since the fading would vary from time to time and the detrimental effects thereof due to the time separation of recording successive picture lines will be avoided t'o a large extent.

As has been above described for consecutive transmission of adjacent lines in connection with the receiver, description will show that with very little changes the embodiment of the receiving apparatus may be made so as to record successive lines, although by Fig. 2 we have illustrated a system for recording spaced lines and by Fig. 5 have shown a record wherein the lines of recording have been spaced in accordance with a system following transmitting and receiving systems disclosed by Figs. 1 and 2.

Now referring more particularly to the re-l ceiving apparatus shown by Fig. 2, a receiving drum 41 is arranged for rotation on a threaded shaft 43 in a mannersimilar to -that of the transmitter shown by Fig 1 and synchronism between the rotation of the drums 1 and 41 may be maintained in a manner described in connection with copending application of R. H. Ranger, Serial No. 51,191, filed August 19, 1925, wherein a tuning fork is used at both the transmitter and receiver for obtaining a relatively fine aljustment of rotational speeds and this is vchecked by means of a seconds pendulum forming a secondary synchronizing means and checking the accuracy of the tuning fork. However, the particular synchronizing arrangement per se forms no part of the present invention and other well known synchronizing schemes may be substituted where de- ,sired.

Carried upon the drum 41 is a sheet 45 for recording the received pictures. In accordance with the preferred embodiment of the invention, since we propose to use for the recording action fiuids or inks projected against the recording paper, we prefer to use what is known as a quick drying paper, although it should be of tough construction and not readily torn.

Signals as transmitted from the transmitter and antenna 21 and 23, respectively, are picked up upon the receiving antenna system 47 and from there directed to a receiving arrangement 49 of any appropriate and well known typehaving its output connected with an amplifying system 51. The output of the amplifier is arranged so that one output connection 53 thereof is directed to one terminal of each of the signal recorders, generally designated A', B', and C, and the other connection 55 thereof is connected through an app-ropriate brush 57 to a slip ring 59 on the shaft 61 of a commutator, generally designated 63, for a purpose to be hereinafter described.

The commutator 63 is driven from the shaft 43 of the picture recording apparatus through an appropriate reducing gear system 65 of the same general type as disclosed by 29 at the transmitter so as to produce one complete revolution of the commutator for each three revolutions of the transmitter drum. The commutator is composed of three sections 67, 69, and 71, each of which is formed of 1% insulating material and 1/3 conducting material, in much thesame manner as the color disks shown by Fig. 3 are composed of 2/3 black, and l@ color portion, so that with the brush members 7 3, 75, and 77 contacting therewith current from the amplifier 51 will successively flow through each of these contacts and influence the respective recorders A, B, and C', wherein recorder C is connected through a connection 79 with the brush 73,v the recorder' B is connected by a connection 81 with the brush 75, and the recorder A is connected through a connection 83 with the brush 77. As herein illustrated output cur rent from the amplifier 51 will flow through the conductor 53 to the recorder A, through the connection 83, the brush 77, the commutating segment 71, the shaft-61, slip ring 59, brush 57, and connection 55, so that the recorder A is energized, if energy is being transmitted from the photo cell arranged behind the disk A at the transmitter. rlhe direction of rotation of the commutator 63 is indicated by the arrow and it will thus be seen that after the recorder A has been energized by energy output from the amplifier 51 that the recorder B will next be energized, and then the recorder C will follow in sequence, after which the recorder A will again be energized and the sequence will be repeated.

The recorders A', B', and C' may be of the general character shown by Fig. 4 of the accompanying drawings and which embody the basic principle of the invention as d1sclosed in copending application of C. W. Hansell in Serial No. 333,617, filed anuary 19, 1929. Although by the present lnventlon a somewhat modified form of recorder has been disclosed, ink or other marking fluld 1s supplied to the recorders A', B', and C' from tanks (not shown) under relatively high pressure through any appropnate supply means such as the tube 85 from which it is projected within the recorder between a pair of plate members 87 and 89. The plates 87 and 89 are connected, as above described, by the connections 53 and 83, (considering recorder A', for example) with amplifier 51 and commutator section 71. The fluid or ink is then projected between these plates 87 and 89 as avery fine stream and flows at high velocity through the nozzle portion of the recorder 91 and against the recording paper 45.

Upon application of signal potentials to the plates 87 and 89 the ink stream projected from the tube 25 along a line 93 through a nozzle 91 is deflected along a path indicated as 95 so as to strike a recessed portion 97 in the nozzle from which it may flow back to the ink supply by way of a trough 99 provided in each nozzle. The supply of ink for each nozzle (not shown) is continually under pressure and, since the colored inks should he projected upon the recording surface only at periods when signals are being received, hy an appropriate arrangement of electromagnetic valves controlled from commutator G3 or as shown) b v placing cams ilpon a shaft 109 driven through appro .iate drive gear mechanism from the re ucing gears 65, we have provided a means whereby each supply of ink may be turned off by the cams closing a valve in the ink supply line during periods when the particular recorder is not in use. These cams are all of similar design and arranged so as to sequentially open supply of ink or other appropriate marking fluid to the recorders A', B', and C', in a manner and time spaced relationship similar to the periods when the commutator 63 connects each successive recorders A', B' and C' with the amplifying arrangement 51. It will thus be seen that the ink or other fluid will not he supplied to any recorder unless the particular recorder is to be used for the purpose of recording the picture.

As has been above illustrated in connection with the transmitter the successive disks or color screen or filters A, B, and C, which correspond to the recorders A', B', and C', we have provided each individual recorder so that the recorder A' is supplied with red r ink, the recorder B' with blue ink, and the and close valves regulating the' deflect the ink stream no marks will be pro- A duced upon the paper. .Since there is practically no inertia in the recorder it is possible to work the transmission system at extremely high rates of speed and thereby increase the efliciency of transmission of pictures and the like, and by recording'on a 90 line screen, for example, it will be seen that there are 30 lines per inch of the picture in red, blue, and yellow so that a good definition of the various shades is obtainable.

As has been above expressed, in order to avoid the detrimental effects of fading and the like in signals, Fig. 5 shows conventionally and upon an enlarged scale the sequence of producing the various marks upon the record sheet 45.

It Will be noted that the first line has been designated as 1 R, the second as 3 B, and, for example, the 6th line as 9 Y, meaning that while the line 9 Y is the 6th line from left to right on the picture it is, nevertheless, the 9th recorded in the recording process since alternate red, blue, and yellow lines are recorded.

It is also possible to utilize in a scheme of the character herein disclosed a two color recording action and obtain satisfactory color definition thereby. Such a system might include, for example, the use of color screens and inks, or other appropriate recording fluids, having a reddish orange tint and the other having a blueish green tint in contrast to the disclosed system using the primary colors, red, blue, and yellow. In connection with this type of scheme the color disks at the transmitter should then be composed of one-half black and one-half either reddish orange or bluish green and two recorders projecting similarly colored recording fluids against the recording surface should work in conjunction therewith at the receiver. This has been shown schematically in Fig. 7, and in this connection it should be borne in mind that when this system is used in connection with a type of transmitter shown by Fig. l, there will be provided only two light sources 7 and two light tubes 9 operating in conjunction with only two photo cells 15, and, similarly, at the receiver there will be only two recorders operating in conjunction with a commutator having only a pair of segments. This has not been illustrated due to the fact that the modification seems obvious and naturally follows from what has been shown by Figs. 1 and 2. If spaced transmission and reception is not desired the color disks at the transmitter might be composed of one-half of' each of the chosen primary colors, as shown by Fig. 8,

i luencing the in the same manner as was sug ested for a disk composed of one-third re blue, and yellow.

In case of the two color system, therefore, if a 90 line screen were used there would be lines per linear inch of the received picture recorded in each color and this would produce substantially the same general effect as 30 lines' per linear inch of each of the colors red, blue and yellow.

By the above disclosure we have shown an arrangement by Which an additive type of colored picture has been produced, but 1t is obvious that by a superposition of the various colors one upon the other a substractive type of colored picture may be produced by the same apparatus for example by rotating the pick-ups and reproducers of Figs. 1 and 2 vrespectively through an angle of 90, or by causing them, in the same respective figures, to converge to the same operative point.

Further, it is also to be understood that the disclosure of our present invention'is applicable to multiplex communication by which all of the various colors may be simultaneously recorded when a multiplex system of the type disclosed by copending application of R. H. Ranger, Serial No. 269,099, filed April 11, 1928 is utilized, or by using a system for impressing the various signals produced in accordance With the light invarious photo cells as separate tone frequencies upon the transmitter and filtering the separate tones at the receiver, as has been disclosed by copending application of R. H. Ranger, Serial No. 309,273, filed September 29, 1928, and copending application of R. H. Rangerl and James N. Whitaker, Serial No. 309,137, filed September 29, 1928.

Other modifications and changes other than those herein suggested as concrete illustrations will at once suggest themselves to those skilled in the art and, therefore, we

desire to be limited in what modifications and' changes may be made only in so far as the scope of the hereinafter appended claims necessitates.

What We claim and desire to claim by Letters Patent is the following:

1. The method of recording pictures in colors closely approximating those of an original which includes receiving signals of varying strength corresponding t0 the several component color tone intensities onl elemental areas of a picture surface being transmitted, projecting a recording medium against a record surface for producing the received picture, controlling the path of the said recording medium in accordance with the strength of the received signals, and successively changing the recording from one to another of a series of recording mediums corresponding in color to the several component colors chosen.

ling the path of the recording mediums projected against said recording surface, and successively and alternately changin the recording action from one to another o said recording mediums for rebuilding the received picture in a line for line manner `in varying colors corresponding to the primary colors from which an original picture was formed.

3. The method of reproducing transmitted pictures in colors closely approximating the colors in an originally transmitted picture vvhich includes receiving signals corresponding in strength to the several component color tone intensities or elemental areas of a transmitted picture, projecting a series of colored recording fluids against a record surface for rebuilding the picture, controlling the path of the recording mediums projected against said recording surface, and successively changing the recording action from one to another 0f said recording mediums for yrebuilding the received picture in a line for line manner in varying colors corresponding to the component' colors from which an original picture Was formed.

4. The method of recording pictures in colors closely approximating those of `an original which includes receiving signals varied in strength in accordance with successive color intensities of severalcomponent colors forming the elemental areasl of a picture surface being transmitted, projecting a recording medium against a record surface for forming a received picture, controlling the path of the said recording medium in accordance with the strength of the received signals, and changing the recording in a predetermined sequence from one to another 'of a series/of component' colored recording mediums.

5. In an ap aratus for recording pictures in colors close y approximating those of an original picture, means for receiving signals corresponding to the predetermined component colors comprising an original picture, a recording surface for recording the said received picture, means for projecting colored recording fluids against said surface, and means for sequentially changing the recording action from one to another of said colored recording mediums.

6. In an apparatus for recording pictures in colors, means for receiving signals varying in strength in proportion to the several component color tone intensities on elemental areas of a' transmitted picture surface, a reico 'ist

- originally transmitted picture,

cording drum carrying a surface for recording the received pictures, means for projecting a plurality of different colored recording mediums against said record surface for producing a received picture, means for controlling the path of said recording mediums in accordance with the strength of said received signal pulses, and means for successively changing the recording 'action from one to another of said colored recording mcdiums for successively building up a received,I picture in a line for line manner inwhicll each successive line is produced in a different color.

7. In an apparatus for reproducing transmitted pictures in colors closely approximating those of an original picture, means for receiving signals varied in accordance with the elemental tones of an originally transmitted picture, a recording drum carrying a record surface upon which the received picture is to be produced, means for projecting a plurality of different colored recording fluids against said drum and record surface, means controlled by said received signals for controlling each of said recording fluids, and means for changing the recording action in sequence from one to another of said recording fluids for producing a picture having the successive lines thereo recorded in different colors.

8. In an apparatus for reproducing transmitted pictures in colors closely approximating those of an original picture, means for receiving signals varied in accordance with predetermined color tones on elemental areas of an originally transmitted picture, a recording drum carrying a record surface upon which the received picture is to be produced, means for projecting a plurality of different colored recording fluids against said drum and record surface, means controlled by said received signals for controlling each of said recording fluids, and means for changing the recording action sequentially and at predetermined time intervals from one to another of said recording fluids for producing a builtup picture.

9. In an apparatus for recording pictures in colors closely approximately those of an means for receiving signals corresponding to the several component tone intensities of elemental areas of the transmitted picture, a recording drum carrying a surface upon which the received signal is to be produced, means for projecting sequentially recording fluids of differing colors against said drum and means controlled by received signal pulses for controly ling each of said projected recording fluids to produce said picture.

In an apparatus for recording pictures in colors closely approximately those of an originally transmitted picture, means for receiving signals varied in accordance with the elemental tones on the transmitted picture, a

which the received signal is to be recorded, a

plurality of electrostatic recording means ad- ]acent said picture drum, means for projecting recording fluids of different colors through each of said recorders and against said drum, and means controlled by received signal pulses for varying the potentials applied to each of said electrostatic recorders for controlling the amount of recording fluid reaching said drum.

1l. In an apparatus for recording pictures in colors closely approximating those of an originally transmitted picture, which in` cludes, means for receiving signals, a recording drum carrying a surface upon which the received signal is to be recorded, a plurality of electrostatic recording means adjacent said picture drum, means for projecting recording fluids of different colors through each of said recorders, means controlled by received signal pulses for varying the potential applied to each of said electrostatic recorders, and controlling thereby therecording fluid reaching said record surface.

l2. In an apparatus for recording pictures in colors closely approximating those of an originally transmitted picture, means for receiving signals varied in accordance with the several component tone intensities of elemental areas on a transmitted picture surface, a recording drum carrying a surface upon which the received signal is to be recorded, a plurality of electrostatic recording means adjacent said picture drum, means for projecting recording fluids of different colors through each of said recorders, means controlled by received signal pulses for varying the potentials applied to each of said electrostatic reeorders, means controlled by the rotation of said recording drum for successively and alternately closing the supply of recording fluid to said recorders so as to supply fluid to only a single recorder at any predetermined time interval, and means also controlled by the rotation of said drum for altenately and successively connecting the said recorders with said signal receiving means so as to produce a recorded picture having successive lines thereof recorded in different component colors and a finished picture in Which the color blending closely approximates that in the said original picture.

13. The method of applying to a surface a plurality of materials of different primary colors for forming a colored record image on the surface which comprises projecting recording mediums, each of a selected primary color, toward a record surface, controlling each of the recording mediums in a manner such that they operate severally, limiting the recording action of each medium to predetermined periods, and independently controlling the amount of each of the recording mediums reaching the record surface.

ing fluids for forming a colored record image on the surface Which comprises projecting 14. The method of producing colored the marking fluids toward the record surface,

duplicates corresponding to originals' transmitted which comprises the steps of projecting a plurality of recording mediums, each of a separate primary color, toward a record surface, varying the time of operation of each of the recording mediums in a manner such that each medium is capable of acting separately upon the record surface for predetermined time periods, and varying the amount of recording medium reaching the record surface in accordance with the tone value of the original corresponding to the primary color projected 15. A system for producing an image from received signaling .impulses corresponding to the component colors of successive elements which comprises a receiving surface, means for projecting a plurality of color marking mediums toward said record, means for controlling the separate marking' mediums independently in accordance with the tone of the primary color of the original represented by the separate marking mediums, and means for limiting the marking action to a single recording medium during predetermined time intervals.

16. A system for producing color duplicates corresponding to transmitted records which comprises projecting a plurality of colored marking fluids, each of a selected primary color, toward a record surface, producing a relative movement between said marking fluids and said record surface so as to cause said marking fluids to trace said record surface in a line for line manner, sequentially changing the recording action from one to another of said marking mediums at each change in the line for line manner of tracing, and varying the intensity of marks of each of the independent marking fluids in accordance with the tone value of the selected primary colors.

17. A system for producing color duplicates corresponding to transmitted records which comprises projecting a plurality of complementarily colored marking fluids upon a record surface, rotating the said record surface relative to the source of said marking fluids so as to cause said marking fluids to trace said record surface in a series of adjacent lines, limiting the action of the marking fluids upon the record surface to a single color fluid at any instant, sequentially changing the recording action from one to another of said marking mediums at the completion of each rotation of the record surface, and varying the intensity of marking of each of the independent marking fluids in accordance with the tone value of the selected primary colors.

18. The method of applying to a surface a plurality of complementarily-colored markcontrolling each of the recording mediums in a manner such that they operate severally, limiting the recording actionof each marking fluid to predetermined time periods during the reproduction, and electrostatica-lly controlling the amount of each separate marking fluid reaching the record surface during the several operations thereof.

19. In an apparatus for recording picturesA in colors closely. approximating those of an original picture, the method which comprises receiving signals corresponding to the predetermined component colors comprising the original picture, projecting toward a recording surface colored recording fluids, and sequentially changing the recording action from one to another of the colored recording fluids.

RICHARD HOWLAND RANGER.

SAMUEL B. SMITH.

lOtl

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