US1731518A - Phototelegraphy - Google Patents

Description

' respondlng to the tone value of a group of Patented Oct. 15, 1929 UNITED STATES PATENT; OFFICE HARRY-GUY BARTHOLOMEW, or LoNno ENGLAND, AND'MAY ARD LESLIE DEEDES MCFARLANE, on NEW YonK, N. Y. a

PHOTOTELEGRAPHY Application filed October 80, 1926. Serial No.i145,1 83.

by a detailed non-pictorial record can be made.

of a picture with a minimum of expense.

* Another object of our invention is to provide a method for making a non-pictorial record of a picture, said record consisting of groups of markings, each said group corsmall areas of the picture to be recorded.

Another object of our invention relates to an improved method of utilizing a photoelectric cell for making a non-pictorial record of a picture which will show considerable detail which has heretofore been omitted because of the expense involved.

Another object of our invention relates generally to improvements in the Bartlane process upon which we have secured a number of patents, such as British Patent No. 195,577. 1

Other objects of our invention will be set forth in the following description and drawings which illustrate a preferred embodiment thereof, it being understood that the above-general statement of the objects of our invention is intended merely to generally explain the. same and not to limit 1t inany manner.

Fig. 1 is a diagrammatic view showing the mechanism for actuating the shutter utilized in connection with our method.

Fig. 2 is a diagrammatic view showing the electrical connections or w ring dlagram of I an apparatus which can be utilized for carrying out our method.

Fig. 3 illustrates the relationsh p of the group of areas of the picturewhlch is recorded by a corresponding group of perfora tions in a record tape.

Fig. l diagrammatically illustrates the picture range utilized.

Fig. 5 diagrammatically illustrates a record tape. y

.Fig. 6 diagrammatically illustrates how each of the areas illustrated in Fig; 3 is divided into five zones.

In the Bartlane process as heretofore utilized, a number of prints of varying intensity or tone effect were taken of the picture to be reproduced. One of these prints was taken my means of a relatively short exposure, the next was taken by a longer exposure, so that each of said prints recorded a predetermined range of the tone values of the picture. For example, the print which was taken with the shortest exposure recorded only the very bright tones of the picture, and the print which was taken with the longer exposure recorded all the tones of the picture:

In the method heretofore employed, these prints were mounted upon a shaft, and reader points were moved relatively to each of the said prints ,so that each of said reader points described a helical path with respect to the corresponding print. Since these prints had the images formed thereon by layers of'insulating material on metal plates, each of said reader points had its electrical contact with said plate. made and broken in accordance with the image-formed by means of the layer of insulating material. Each of these metal plates was connected to one terminal of a source of electric current whose other terminal was connected to the corresponding reader point, so that the circuit-of said source of current was made and broken as the reader point In the Bartlane method as heretofore utilized, the reader points simultaneously contacted at all times with corresponding,

small areas of the respective prints. Hence, the number of perforations in each group formed upon the record tape corresponded to the tone value of a single small area of the picture.

In order to secure sharp detail, it was necessary tomake the pitch of the helical path of each reader point very small, but this resulted in the punching of a tape which was so long that the expense of reproducin the same was prohibitive. Hence, in the artlane process as heretofore utilized, a great deal of detail was necessarily lost, because no record was taken of those zones or strips of the print which were intermediate the lines along which the reader points moved. Since each reader point had a very small diameter, the diameter of each small area of the picture which was recorded was much less than the pitch of the said helical path.

According to the present invention, reader means, which are preferably photo-electric,

, tape, because the tone value of each small area of the picture is recorded by means of a single perforation, instead of by a group of perforations. That is, according to our improved method, each group of perforations on the record tape corresponds to the tone value of a lateral group of small areas of the picture.

As diagrammatically shown in Fig. 1, the picture 1 is mounted upon a roller 2 which is given a suitable rotary and longitudinalmovement so that the/said picture 1 and the beam of light 3 have a relative helical movement. The beam of light 3 is projected upon the picture 1 from the lamp-house 4, which can be provided with suitable lenses. After having been reflected from the picture, the

beam of light passes through a lens 4 and then through the opening of a shutter 5 which is mounted in a suitable guide. The reflected beamof light then falls upon a' photoelectric cell 6 to affect the resistance of the same in the well known manner.

The width of the lateral zone of the film which is illuminated bythe beam of light 3, is diagrammatically shown in Fig. 3 and may be considered as being made up of five portions, namely, A, A A A and A each said lateral portion being equivalent to what i may be termed a small area of the picture,

that is, an area whose tone value was previously determined by any suitable reader meansfeither mechanical or photo-electric. The shutter 5 has a slot or opening 5' which is equivalent to one of the five zones of one of the small areas shown in Fig. 3, so that as the shutter is reciprocated, the light from se-" lected zones z'-e of the respective small .areas is allowed to successively fall upon the photo-electric cell.

The shutter his-connected to thelever 7 which is pivoted at 8 and which is connected to the rod 9. The rod 9 is actuated by the of the areas A''A to be recorded by means of the photo-electric cell. The shutter is then given quick return movement by tension spring7' to the position corresponding to the zone a of area A and no record is made of the picture during this quick return movement. The width or. lateral dimension of an area AA? may be equivalent to the pitch of the helical path defining the relative movement between the reader and the picture, so

that all the zones of substantially all the small areas of the picture are recorded, thus giving much sharper detail.

As shown in Fig. 2, the photo-electric cell 6 is provided with the usual battery 7 and r the connections between the electrodes of the photo-electric cell comprise a very high resistance 8. The cathode of the photo-electric cell is connected to the grid 9' of a triode 10. The filament 11' of the triode is provided with a battery 12 in the well known manner. Theplate 14 of the triode is connected to the positive terminal of the battery 16, which may have a high voltage, as high as 400 volts. The use of this-triode for amplifying the electrical effect due to the change in resistance of the photo-electric cell and the corresponding connections form no part of this application per se, as these are shown in a previously filed application for U. S. Letters Patent I The battery 16 is connected to the plate 14 through the spacing coil S of a polarized relay 17 which may be of any suitable type. A battery 15 has one terminal connected to the marking coil M of the relay 1'? and each electrical pulse produced by the change in resistance of the photo-electric cell 6 is utilized to form a record of each small area A- 5 in the following manner As shown in Fig. 4, the current output from the amplifier or triode 10 is depicted by a curve which has a straight line portion indicated as the picture range. In this picture range the current supplied-by the amplifier varies uniformly in proportion to the tone value of the light which affects the photo-electric cell.

Each of the electrical pulses produced by means of the photo-electric cell for each movement of the shutter 5 is caused to select one of the punches which form the perforations T in the record tape T. The punches are not actuated until the shutter has been given the five movements required to read the areas AA When the shutter-'5 has been given the'five intermittent movements necessary to read the five areasA-A the punch is then actuated to operate the punches which have been selected, so as to form a group or row of perforations T, each said perforation coresponding to the tone value of one of the zones of the areas A' A As the, punches are selected for forming each row of perforations, they are held in the selected position until the hammer is operated, and the punches are then released to their inoperative position after they have been operated by the hammer so as to leave the said pu nches free to be again selected for forming the next row of perforations.

' The five punches (which are not shown herein as they are sufficiently described and well known to the art) are selected by means of selector coils M, M M M and M Each of these coils MM is connected to on end of a battery 18 and the other terminal of said battery 18 is connected by means of the conductor 19 to the relay switches R, R R R and R It is clear that whenthe relay switches RR are moved into the closed position, that the corresponding selector coils are energized. The relay switches R'R are respectively associated with relay magnetic coils C C C and C and when these relay coils C'-Q are energized, they close not only the switches RR but they also close lock switches L, L L L and L The relay coils CC are energized by the battery 19 when the switch 20 is closed in the following manner The shaft 11 is surrounded by four stationary metal rings D, D D and D The inner and outerrings D and D are continuous and the two intermediate rings D and D are each divided into six corresponding segments by means of sheets of insulation 21. For convenience, each of the segments of the intermediate rings D and D at the right of the top insulation 21 may be designated as the first segments and the succeeding segments may be designated as the second, third, fourth, fifth and sixth segments respectively. A brush arm 22 is connected to the shaft 11 so as to turn therewith, and this brush arm is \provided with two forked brushes 23 and 23 re- .spectively. The outer brush 23 is adapted 'to continuously connect the outer ring 13* to one of the six segments of the outer intermediate ring D? and the inner brush 23 is adapted to correspondingly connect the continuous inner ring D to one of the six segments of the inner'intermediatering D Of course, said'contact is broken when the adjacent members of the brushes 23 and 23 pass over the strips of insulation 21 The first segments'of the rings D and D may be designated as the dead segments, so that each of said rings D and D has a dead segment and five live segments. 4

The relay 17 is of the well known type in which the. needle or relay arm 17 is held at either of the points 17 2 and 17 by the fixed tion of a punch by the coil M if the current output from the amplifier or thermionic tube is equal to or greater than 21 milliamperes. On the contrary, if the current output from the amplifier, which passes through the spacing coil S, is less than 21 milliamperes, which would correspond to a'very dark tone for the area A, then it is desirable that none of the coils MM should be energized to select any of the five punches. The coil 0 must be energized to close the relay switch R and thus energize the coil M. In order to energize the coil C, it is necessary for the relay armature or needle 17 to move to the position 17 because the position 17 is not utilized in this embodiment of our method. The strength of the current passing through the marking coil M from the battery 15 is determined by the position of the brush arm 22. If the brushes 23 and 23 are on the first or dead segments of the rings D and D then none of the relay coils CC can be energized. If the brushes are on the first live segments of the rings D and D as indicated in Fig. 2, then the circuit is as follows One of the terminals ofthe battery 15 is connected by the conductor 15 to the continuous and stationary outer ring D. The other terminal'of the battery 15 is connected by means of the marking coil M and the conductor 15 directly to thefifth live segment of the ring D The last mentioned terminal of the battery 15 is also connected to the fourth live segment of the ring D by means of the resistance W, it is also connected to the third live segment of the ring D through the resistances W and WW; it is also connected to the second live segment of the ring D through the resistances W, W and W and it is finally connected to the first live segment of the ring D through the resistances W ,-W W and W. When the parts are in the position shown in Fig. 2, the current which passesth'rough the marking coil M also passes through the resistances W, W WV and W to the first live segment of the ring D and from there it passes to the brush 23 to the continuous outer ring D, thus completing the circuit of the battery. 15. Thevmarking current is therefore relatively small because its circuit includes four resistances. Since the marking current is small, it only requires a relatively small current through the spacing coil S to move the armature 17 to the position 17 since this requires only a very slightcxcess of current in the spacing coil over that passing through the marking coil., \Vhen the armature 17 has moved to the position 17 current passes from-the battery 19 through the coil C, then" to the first live segment of the ring DLby means of conductor 30,.through the brush 23' to. the ring D, from there to the terminal 17 by means of the conductor 10 31, and from the terminal 17 through the needle 17' and then to the other terminal of battery 19' by means of conductor 32. The coil C is therefore energized so as to close switches R and L. As soon as switch L is in the closed position, the current from battery 19' continues to pass through the coil C as long as the switch 20 is in the closed position. None of the relay coils, save the coil C can be energized as long 20 as the brushes23 and 23 are in contact. with the first live segments of the rings D and D Hence, the magnet M will become and remain energized to select one of the punches ifthe tone value of the zone a of area A is lighter than a black tone. \Vhen the slot is in the position, to cause the light refiected from a zone of the second area A to fall upon the photo-electric cell, the brushes 23 and 23 contact with the second live segments of the rings D and D. In this position the. second relay coil C can be energized if the current delivered by the thermionic tube is equal to or above 24 milliam'peres. It is clear that when the 35 brushes 23 and 23 contact with the second live segments of the rings D and D that the resistance W has been cut out, because the resistance coil W is directly connected to the second live segment of the ring D by means of the conductor 33. It will also be noted that the relay coil C has one end thereof connected to the second live segment of the ring 2 by means of the conductor 34. Hence, when the selected zone of the area A is being read, the current passing throughtl erharking coil will be greater than when the selected zone of the area A is being read, and it requires a brighter tone tocause suificient current to pass through the coil S to actuate the relay armature 17 and thus cause the coil C to be energized. It will be noted that the armature 17 moves away from the contact 17* as the brushes passover the sheets of insulation 21..

Similarly, the coilC cannot be energized eo gized when the selected zone of area A is being read unless the current output from the arnnlifier is equal to or greater than- 35 milliamperes; and the relay coil C, cannot be energized when the selected zone. of area A is being read unless the current output when the. selected zone of thearea A is being from th amplifier is equal to or greater. than 39 milliamperes. I

Hence,'while the brushes 23 and 23 are in contact with the fifth live segments of the rings D and D the magnets MM will have been energized to select their respective punches or will have remained unenergized in accordance with the tone values of the selected zones of the areas A'A As diagrammatically shown in Fig. 2, the width of the slot 5' of the shutter 5 is less than the width of one of the areas A-A It ispre ferred that the width of the slot 5' should be one-fifth the width of one of the areas AA It is also preferred that the slot 5 should be located at the extreme left-hand portion of the area A 'when the area A is bein read of light 3 may be assumed as being equal to the width of an area A. Formerly, the nu1nber of perforations in each group of five corresponded generally to that portion of the area A which was passed over by the reader points, and of course, a great deal of detail was lost, because the diameter of the reader point was and necessarily is much smaller the present and improved method, the first setting of the fivepunches and the first record produced by the actuation thereof depends than the width of the area A. According to K upon the-tone values of the first or left-hand zone 2' of the area A, the second zone 2 of the area A the third zone 2 of the area A, the fourth zones of the area A, and the fifth zone a of, the area A". For convenience, the tone below the line designated as 21 in Fig. 4 may be designated asa pure black, the tone value corresponding to a value equalto or above 21 and below 24 can be designated as the firstgray tone, and the succeeding tones may be respectively designated as second gray, third gray, fourth gray, and finally, the pure white tone, The black tone will, of course, be represented by the total absence of perforations in a given row, and the pure white tone will be designated or reproduced by means of five or the maximum number of perforations in a given row. This analysis relates to the reproduction of a negative; Of course, when a positive or'printis produced the relations between the tone values should be reversed.

When the beam of light 3 makes its second movement overthe picture 1, the apparatus now reads the first zone of area A, the second I zone of area A, the third zone of areaA,

' respective areas.

and the fourth zone of area A. In order to causethe selection of punches, the zones which are read in the second movement of the reading means may have lower tone values than during the first reading of the zones of. the The various"zones of the respective areas are thus read until all the zones of the area A have been read at the fifth movement of the beam of light. Every small area of the picture .to the right of the area A will thus haveall the zones thereof read, which insures the recording and repro duction of the fine details of practically the entire picture. a

For example, in the second movement of the reading means, the shutter 5' will cause the reading of the zone 2 of the area A, the zone 2 of the area A the zone 2 of the area A, the zone 2* of the area A and the zone .2 of the area which is at the right of area A.

In the next movement of the reading means they will cause the reading of the zone 2 of the area A the-zone e of the area A the zone 2 of the area A In the next movement of the reading means they will cause the reading of the zone 2 of the area A and the zone .2 of the area'A The next movement will cause the reading of the zone 2 of the area A Hence, every area to the right of A and also including area A will have the five zones thereof consecutively read from right to'left.

Experience has shown that by reading the respective zones of each small area according to a different ratio or relationship between black and the lighter tones, that much more detail and abetter picture are secured.

While we do not wish to limit ourselves to the varying ratio of the readings of the respective zones of each small area shown in i Fig. 4, we prefer this relationship, as its value.

has been proved by. actual experience.

The switch 20 can be opened by any suitable member actuated by the shaft 11, during the period that the brushes 23 and 23 are passing over the first dead segment of the rings D and D. This wipes out the-settings of the various selectors and allows them to be selected anew for forming an additional row of perforations.

We do not wish to be limited to anyspecific pitch for the helical path of movement of the reading means, but the preferred embodiment of our method above explained secures the greatest amount of detail for a minimum length of tape.

It is also obvious that our method can be utilized for directly transmitting the electric pulses produced as above mentioned, in-

stead of utilizing said pulses for forming a record tape at the transmitting station.

According to the embodiment of our method lllustrated herein, we produce electric pulses in the relay coils (1-C and also in the selector coils M M and the consecutive pulses depend upon a varying sensitiveness of the reader means which include the relay 17. For example, in making the first reading of a lateral group of zones in area A and succeeding areas, the reader means operate with a minimum sensitiveness to produce an electric pulse corresponding to a light tone, and-the sensitiveness of the reader means is thereafter varied (increased, in this embodiment), so that succeeding electric pulses are produced by tone values of decreasing brightness to cause the selection of a punch. Wheneverwe specify that the sensitiveness of the reader means is varied, we wish to exclude devices having perforated discs which act as shutters to merely rapidly and intermittently expose the reader device to the source of light. I

While we have mentioned the reproduction of a picture, we desire that this term should include all black and white matter,

such as signatures or the like.

We have shown a preferred embodiment of our invention, butit is clear that numerous changes and omissions could be made without distance of each member of the group of zones from the preceding member 'of the same group I is equal to the pitch area, plus the area of a zone.

While we have specified that a non-pictorial record is made of the tone values ofa picture by means of groups of perforations, the use of perforations is merely illustrative of our invention, which covers the use of any markings or impressions made upon a member to change the properties of certain designated portions thereof.

In order ,-to reproduce a picture by means of a perforated tape, the perforations in the tape are caused to control the passage of lightthrough separate openings, each of these light openings having an independent shutter so that the amount'of light transmitted therethrough can be suitably regulated. Hence, each perforation in each group controls the passage of a light beam of varying intensity. The images of the openings which are H luminatedby the passage of light therethrough are focused upon a sensitive film by means of a suitable lens so that five images of light are fbcused upon the film in the same relationship as thefive zones which were read to form each group of perforations, as I .while producing electric pulses, and varying the sensitiveness of the reader means, the sensitiveness of said reader means belng varied independently of any color variations in said small areas and independently of the locations of the said small areas.

2. In the art of producing electric pulses corresponding to the tone values of a picture, that step in the art which consists in reading the areas of the said picture in a series of successive groups and varying the sensitiveness of the reading means while each group is being read,the sensitiveness of said reader means being varied independently of any color variations in said small areas and independently'of the locations of the said small areas.

3. In the art of producing electric pulses ,corresponding to the tone values of a picture,

that step in the art which consists in reading theareas of the said picture in a series of successive groups and increasing the sensitiveness of the reading means to light while each group is being read, the sensitiveness of said reader means being varied independently of I ,any color variations in said small areas and independently of the locations of the said smallareas.

4. Indie art of producing electric pulses corresponding to the tone values of a picture having a series of consecutive small areas each the markings of each said group corresponding to the tone value of a plurality of zones of said picture, I said zones being respectively located in a series of consecutive small areas, said zones occupying different relative positions in their respective small areas. s

'7. A non-pictorial record of the tone values of a picture comprising a plurality of groups of perforations, the perforations of said respective groups each corresponding to different relative tone values of a selected group of zones of the picture which is reproduced, the zones of each group being longitudinally disposed and the respective groups being helically disposed.

8. A non-pictojal record of the tone values of a picture comprising a plurality of groups of perforations, the perforations of each of said groups corresponding to different relative tone values of a selected group of zones of the picture which is reproduced, the light values of said zones corresponding to similarly positioned perforations in each said group being of substantially uniformly increasing value. v

In testimony whereof we aflix our signatures.

HARRY GUY'BARTHOLOMEW. MAYNARD LESLIE DEEDES McFARLANE.

of which may be considered as consisting of r a plurality of successive zones, those steps in the art which consists in producing a series of pulses corresponding to zones diiferently located in their respective areas, and reading the picture by producing a plurality of said series of pulses.

5. In the art of forming a non-pictorial record of the tone valuesof apicture, that step in the art which consists in reading a series of longitudinal groups of small areas of the said picture to produce electrical pulses corresponding to the tone values of the said zones, the respective groups being helically disposed causing each of said electrical pulses to selecta marking member and to retain the said marking member in the selected position,

actuating the said marking members after they have been selected, and releasing the 7 marking members.

6. A non-pictorial record of the tone value of a picture comprising groups of markings,

Images