US2293812A - Portable facsimile synchronizing system - Google Patents

Description

Aug. 25, 1942.

w. e. H. FINQH PORTABLE FACSIMILE SYNCHRONIZING SYSTEM Original Filed March 24, 19:57

3 Sheets-Sheet .1

lhwentor x (Ittomegs Aug 25, 1942. w, Fmc 2,293,812

PORTABLE FACSIMILE SYNCHRONIZING SYSTEM Original Filed March 24, 1937 4 5 Sheets-Shet 2 3 v i I Z'mventor W,%VM

we (Ittomegs a 1942. w. e. H..F|NCH PORTABLE FACSIMILE SYNCHRONIZING SYSTEM Original Filed March 24. 1937 5 Sheets-Sheet 3 u attorney Patented Aug. 25, 1942 sysrEM William G. H. Finch, New York, N. Y.

Original application March 24, 1937, Serial No.

132,690, new Patent No. 2,109,109, dated February 22, 1938.

Divided and this application February 22, 1938, Serial No. 192,194

3 Claims.

This invention relates to facsimile systems and more particularly relates to improvements in facsimile receivers for recording pictures or messages on a continuously fed record sheet.

This invention is a continuation of my pending application Serial No. 123,770, filed February 3, 1935, now Patent No. 2,203,461, issued June 4, 1940, entitled Continuous sheet facsimile system and a division of my application Serial No. 132,690, filed March 24, 1937, now Patent No. 2,109,109, issued Feb. 22,- 1938,

entitled Continuous sheet facsimile recorder.

In this co-pending application I have disclosed novel and simplified mechanism particularly useful for rugged, compact and mobile facsimile units, and have particularly described their application to a transmitter unit. The present application relates to a receiver unit embodying the scanning and sheet feeding arrangements disclosed therein together with novel methods of and means for actuating the recording stylus and maintaining synchronous movement between the transmitter and receiver.

The mobile facsimile receiver of my present invention operates from a .roll of treated paper and directly records the messages or pictures thereon, without intermediate photography processes. The simplified mechanism results in a mobile receiver which is particularly-useful for aircraft, ship, and automobile, as well as for home reception and other instances where a compact and relatively inexpensive unit is required.

Figure 2 is an elevational view of the receiver unit. 5

Fi ure 3 is a top view of the receiver unit.

Figure 4 is a perspective view of the electro mechanical recorder with its elements detached.

Figure 5 is a cross-sectional view taken alon 5-5 of Figure 1 through the electromechanical recording unit.

Figure 6 is a top view of the recording unit corresponding to the view taken along 66 in. Figure 1.

Figure 7 is an enlarged cross-sectional view of a preferred arrangement for the stylus mech-' anism.

Figure 8 is a cross-sectional view taken alon 8-8 of Figure 7. I

Figure 9 is a perspective view of the assembled receiver unit.

Referring to the figures, and more particularly to- Figures 1, 1A, 2, and 3, I illustrate the a facsimile receiver mounted on a cast iron base The objects of my present invention reside in providing a novel electromechanical stylus for direct quality recording upon a record sheet; to provide a novel translating unit which is electromagnetlcally balanced and substantially uniformly responsive to the frequency range necessary for quality black-white recording; and to provide improved methods of and means for maintaining the receiver unit at synchronous speed.

These and further objects of my present invention will become apparent in the following description taken in connection with the drawings, in which:

Figure 1 is a l elevational view, partly in crosssection, of a preferred embodiment of a mobile facsimile receiver employing the features of my present invention.

Figure 1A is a view, partly in cross-section, taken on line lalu. of Figure 7,looking in the direction of the arrows.

ID. A motor ll supplies the continuous drive for the operation of the scanning unit. Motor H is preferably a constant speed direct current motor for operation at a substantially constant speed. I prefer to employ a motor operable at 1800 revolutions per minute. By using a battery source for driving the motor aboard an aircraft or other vehicle, a uniform speed of operation is assured. It is to be understood that a motor at the associated transmitter is operated at the predetermined speed which corresponds to the scanning speed of the system.

To facilitate maintaining the speed of motorclose to the predetermined value over arelatively long period of operation, I prefer to use a speed governing device appended thereto. In Figure 1 I illustrate a mechanical speed governor I2 attached to the shaft l3 extending from the motor. By adjusting the position of the friction. pad l4 against the disk l5 by means of thumb screw 16, the governor may be set for the predetermined speed, which speed will be satisfactorily maintained over many days or even weeks of use. The disk I'I, having alternate dark and light markings, is employed to adjust the governor l2 setting to the required speed with the aid of a tuning fork in the manner described in my co-pending application Serial No. 128,920, filed March 4, 1937.

I prefer to employ the synchronizing circuits and arrangements disclosed in my Reissue Patent No. 19,575, filed May 2 1935, entitled "Image broadcasting system and also disclosed in my Patent No. 2,047,863. This synchronizing systern employs a synchronizing magnet l8 shown mounted upon motor I by bracket 28; an armature 2| for magnet l8 having a projection 22; and a single revolution positive clutch. 23 cooperating with the armature projection 22.

A synchronizing impulse is transmitted cycli cally between the intervals of the line by line recording, which impulses are impressed upon the synchronizing magnet through connection leads 24 to attract the armature 2| and projection 22 away from the single revolution clutch satisfactorily performed by such regular phasing operations. Accordingly, the motor H speed need not be precisely synchronous with the corresponding transmitter motor speed but be substantially close to the predetermined speed as will be evident. The constant speed motor in combination with the mechanical or an equivalent electrical governor performs excellent picture synchronizing and phasing for long periods of operation; I Motor continuously drives the pinion 25 which is keyed to a sleeve 26 surrounding the vertical shaft 21. The housing .or driven member of clutch 23 is integral with the sleeve 26 at the extended or shoulder portion 28 thereof. The sleeve 26 is rotatably supported in the easing 29 of the motor The driven or interior portion 38 of the positive clutch 23 is secured to the vertical shaft 21 by a pin3l. When the clutch 23 is in ngaged condition, the continuously driven pinion 25 drives the vertical rod 21 through the clutch 23. A spring 32 biases the armature projection 22 against the periphery 33 of the clutch 23 to disengage the clutch at the end of a single revolution and maintains such disengagement until the synchronizing magnet I8 is energized by the cyclic synchronizing impulse. I prefer to drive the motor I at a slightly greater speed than the predetermined speed for example, in the ratio of 1012100 to insure the disengagement of the clutch before the advent of the synchronizing impulse. Cams 34, 35 are secured to the top of vertical shaft 21 and co-' operate with the synchronizing cam switch 38 which switch is connected to the cynchronizing electrical circuit (not shown) by leads 31.

A gear 38 is attached to the bottom of the vertical rod 21. The gear 38 operates the oscillating scanner arm 48 which carries'the stylus. In the illustrated arrangement, one oscillation comprising a single forward and return movement of the scanner arm 48 is performed during one revolution of the rod 21. A preferable scanning speed for this system is sixty lines per minute corresponding to one revolution per second of the vertically driven shaft 21. A cam 4| is .used to execute the desired movement of the scanner arm 48.

Cam 4| is connected to gear 42 which meshes with and is driven by gear 38. Cam 4| is rotatably supported on rod 43 which is aflixed to the base I38 in bushing 44. A cam follower 45 is actuated by the cam 4|. The follower 45 is connected to the vertical rod 46 which in turn is directly connected to the electromechanical recording unit 41. The cam and oscillatory motion mechanism 4| to 45 is similar to the corresponding mechanism of the transmitter described in more detail in my co-pending application Serial No. 123,770 hereinabove referred to. I

The base 48 of the recording unit 41 is keyed to the top of vertical rod 46 and is accordingly oscillated therewith as will now be evident. The scanner arm 48 is secured to the magnetic casing structure 58 of the recording unit 41. Arm 48 extends from the magnetic unit 41 to the record sheet 5| and supports the stylus rod 52. A steel point 53 is carried at the end of rod 52 for direct recording on the record sheet 5| in a manner to be described. The stylus is oscillated against the record sheet 5| in accordance with facsimile signals. By maintaining synchronous movement of the scanner arm 48 and by proper advancing or feeding of the record sheet 5|, line by line past the scanning position, accurate reproductions are readily made thereon.

The styluspoint 53 is preferably made of steel to resist wear. A heater coil-54 is wound at the stylus tip. The heater coil 54 is connected to a heating current supply by leads 55. A direct current'of six to twelve volts is a suitable supply to maintain the stylus point 53 continuously heated for therecording operation. The record sheet 5| 1 in my preferred mobile facsimile unit is a colored sheet having a wax coating. The wax coating is melted along the portions at which the heated stylus 53 operates against the waxed surface. For black-white reproductions I em- I ploy a black paper coated on the recording sur- .face with a layer of white colored waxy substance. The wax coating exists on the surface under all weather conditions and is melted at the portions at which the heated stylus point 53 makes contact. The picture signals represent the black and white markings and actuate the stylus rod 52 in a manner to be described, to and fro against the sheet 5| to reproduce the picture. The continuous record sheet 5| is arranged in a large roll 56, and is fed past the stylus 53 in a positive manner, a predetermined amount between each scanning line. Y

The line by line sheet feeding mechanism is similar to the corresponding feeding mechanism disclosed in my co-pending application Serial No. 123,770 and comprises a rocker arm 51 actuated by a cam 58. The cam 58 is secured to the vertical driven rod 21 which is rotated in accordance with the scanning movements. The rocker arm 51 actuates a pawl and ratchet arrangement 59 which rotates the presser roller 58 to a degree suflicient to advance the record sheet 5| by the distance between successive scanning lines. The advancing movement is executed once per revolution of the rod 21 and corresponds to one scanning oscillation of the scanner arm 48. I prefer to employ sixty lines per inch whereby one inch of the final picture is recorded in one minute.

The recordv sheet may be independently advanced by means of the handle 6| which operates the rollers-82. The operator may thus advance a recorded portion from the region of the stylus 53 beyond the interior of'the machine. Figure 9 is a perspective illustration of the facsimile recorder unit with the recordsheet 5| containing pictures made thereon. The-handle 5| is used to move the sheet 6| out of the machine for viewing of the recordings thereon.

An important feature of my present invention resides in the novel electromagnetic arrangement 41 for operating the stylus 52-53 against the record sheet 6|. Figure 4 is a perspective illustration of the unit 41 blown-up to more clearly illustrate the construction thereof. The

electromagnetic unit 41 provides a balanced torque action on the armature 63. The stylus rod 52 is mechanically pivoted at 64 to the top of armature 63. The armature 63 is independently pivoted on rod 65. Rod 65 is supported in bushings 66 set into angle brackets 61.

The electromagnetic mechanism 41 is arranged to oscillate armature 63 about its pivotal support 65 in response to the electric signal impulses corresponding to the shade or black-white characteristics of the transmitted picture. The facsimile signals are received and preferably rectified in a conventional manner and introduced to the connection leads 10 of the coils 1|. The'coils 1| are arranged concentric with and at opposite ends of the pivoted armature 63 to variable magnetize the armature and cause it to vibrate between the pole faces 12-12. The pole faces 12 are formed in 'two C-shaped opposing portions inwardly tapered toward the armature 63. 13-13 are placed adjacent opposite sides of the pole pieces 12-12 to create a permanent magnetic field across the airgap's including the pivoted armature 63. Although my preferred illustration shows permanent magnets 13, it is evident that Permanent magnets mark the record sheet. Accordingly. a blackwhite reproduction will result from the marking impulses of the stylus 53 moving in synchronism with the transmitter scanner.

The reciprocating stylus mechanism is designed to have a small moment of inertia and proportioned according to well known dynamic principles to be substantially equi-responsive to the whole frequency band necessary to translate the picture signals. Figure 7 is an enlarged detail cross-sectional view of the reciprocating stylus mechanism actuated by the armature 63 which controls the movement of the stylus rod 52 at the end of which is secured the stylus point 53. The

electrically connected to the battery 18 is preferably made of steel to resist wear. The stylus rod electromagnets may be substituted therefor to produce the uniform direct current field across single currents flowing through the coils 1|1|,

superimpose a variable magnetic field on the armature 63 and across the air gaps 14 to correspondingly oscillate the armature 63 about its pivotal support 65. The stylus arm 52, pivotally connected at 64 to the armature 63 is correspondingly oscillated in accordance with the signals received. The stylus point 53 is impinged against the record sheet 5| preferably during the black portions of the picture shading. By arranging the circuits to send current through the coil -1| during the dark picture portions, the stylus point 53 will be pressed against the record sheet during such dark portions to melt the wax coatingthereon and represent a corresponding black or colored line on the reproduction.

A block 15 (Figure 1) is placed against the record sheet 5| opposite'the scanning region to rigidly hold the sheet 5| in position during the excursions of the stylus point 53 against the sheet. The block 15 is arcuate to correspond to the path of the oscillating scanning point. The radial lines 16 on Figure 3 define the end portions of the scanner arm 40 in its oscillation path. By holding the record sheet 5| in the arcuate path 11 defined by the radius of the stylus, the sheet will be equidistant with respect to the stylus 53 at any point in its excursion. By adjusting the stylus point 53 to clear the record sheet 5|, signals impressed upon the electromagnetic system 41 will cause the stylus point to advance toward the sheet held in the arcuate path 11 and correspondingly armature 63 and bring the stylus 52 is preferably made of very light material such as aluminum and is also hollow to reduce its mass and inertial reaction.

The scanner rod 52 is slidably supported in bushing 88 at the end of the arm 46 and secured to the barrel 8| by set screw 82. Barrel 8| is pivotally supported by pins 64 at the top of armature 63. A spring 83 is contained within barrel 8|. A plug or pin 13 is interposed between the spring and the pivot 64. The spring is compressed so that the barrel is mechanically biased toward the stylus or record sheet with respect to the slidably contained pivot pin 64. A screw 84 is threaded into the barrel 8| and is operated against the pivot pin 64 at the side opposite to the spring 83. The normal distance of the stylus point 53 from therecord sheet 5| is adjusted by means of the screw 84. This adjustment is made by suitably positioning the barrel with respect to the pivot 64 on armature 63. The barrel 8| is slotted at its midportion to permit such variable positioning. The spring 83 maintains the pivoted relationof the barrel 8| with respect to the pin 64 intake, as determined by the adjustment of screw 84. vIn a practical unit, I use a distance of .006 inch for the stylus point 53 away from sheet 5| corresponding to signal-off position. The signals corresponding to black energize the coils 1| of the electromagnetic structure 41tomove the point 53 against the sheet 5|.

I provide means to control the maximum movement or excursion of the stylus by the thumb screws 98 threaded in the base portion 48 of the recording unit 41. the unit 41 near the free end 9| of the armature 63. The end 9| is restrained from vibrating beyond the ends of the screws 9|] and accordingly protects the stylus 53 .from digging into the sheet 5| for an especially intense signal.

Figure 9 is a perspective view of the exterior'of a facsimile receiver unit. The cable 86 contains the electrical connections for the motor stylus heater coil 54, and the rectified facsimile signals for the recording magnet structure 41. The positive-reproductions of the transmitted picture are seen on the extended portion of the record sheet 5|. The case 81 for the unit may have a streamlined and pleasing appea ance as shown, particularly for home use where the unit should have a pleasing appearance and harmonize with the surrounding furniture. For aircraft installations and other applications where definite length or The screws project into I bodiment of my present invention, modifications will become evident to those skilled in the art and accordingly I do not intend to be limited except as set forth in the following claims.

a speed governing device coupled to said motor and responsive to the speed thereof for maintaining the motor speed at a substantially predetermined value, a'driving connection between said motor and scanner containing a clutch and means for cyclically engaging and disengaging said clutch in response to cyclically received synchronizing signals to maintain said scanner in proper phase relation for each line of facsimile scanning and an electromagnetically balanced translating unit responsive uniformly to the necessary frequency range for quality blackwhite recording driven by said scanner.

2. A facsimile receiver comprising a scanner, means for driving said scanner in synchronism with the transmitter scanner including a motor operable at approximate synchronous speed, a synchronous speed governing device coupled to said motor and responsive to the speed thereof for maintaining the motor speed at a substantially predetermined value, a driving connection between said motor and scanner containing a clutch and means including an electromagnet having an armature normally biased against said clutch for cyclically engaging and disensaging said clutch in response to cyclically received synchronizing signals to maintain said scanner in proper phase relation for each line of facsimile scanning and an electromagnetically balmotor for maintaining the motor speed at a substantially predetermined constant value, a driving connection between said motor and scanner containing a clutch and means for cyclically engaging and disengaging said clutch in response to cyclically received synchronizing signals to maintain said scanner in proper phase relation for each line of facsimile scanning and an electromagnetic unit comprising a pivoted armature,

a stylus rod mechanically pivoted to the arma ture and coils arranged concentric with and at opposite ends of said pivoted armature to variably magnetize said armature and cause it to vibrate, said electromagnetic unit being mounted on said scanner.

WILLIAM G. H. FINCH.

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