US2109109A

US2109109A - Continuous sheet facsimile recorder

Info

Publication number: US2109109A
Application number: US132690A
Authority: US
Inventors: William G H Finch
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-03-24
Filing date: 1937-03-24
Publication date: 1938-02-22
Anticipated expiration: 1955-02-22

Description

Peli. 22, 1938.

w. G. H. FlNcH CONTINUOUS SHEET FACSIMILE RECORDER 3 Sheets-Sheet 1 Original Filed Feb. 3, 1937 l I @3 l Hi Irv m. ,Iii Q. NIT@ mw mm E NN. uw l um. E- QE ww EN \1\\\\\\ `mvENrOR. )Cfnch Willmrl Feb. 22, 1938. w. G. H. FlNcH 2,109,109

CONTINUOUS SHEET FACSIMILE RECORDER original Filed Feb. s, 1957 5 sheets-sheet 2 ATTORNEY.

Feb. 22, 1938. w. G. H. FlNcH i 2,109,109

CONTINUOUS SHEET FACSIMILE RECORDER Original Filed Feb. 5, 193'? 3 Sheets-Sheet 5 n 1N VENT OR, will; am'gj'nch ATTORNEY.

lso

Figure 6 is a top view Patented' Feb. 22, 1938 PATENT OFFICE 2,109,109 CONTINUOUS SHEET FACSIMILE accomuna William G. H. Finch, Spily'ten Duyvil, N. Y". Continuation of application Serial No. 123,770,

February 3, 1937. 1937, Serial No. 132,690

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 copending application Serial No. 123,779, illed February 3, 1937, entitled Continuous sheet 4facsimile system." In this co-pending application I have disclosed novel and simplified mechanism particularly useful for rugged, compact and mobile facsimile units, and have particularly de-l scribed 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 simplied 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.

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 electromagnetically 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 present invention. y

Figure 2 is an elevational view of the receiver unit.

Figure 3 is a top view of the receiver unit.

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

Figure 5 is a cross-sectional view taken along l-I o! Figure 1 through the electromechanical recording unit.

of the recording unit This application March 24,

corresponding to the view taken along 6-6 in Figure 1.

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

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

vligr9 is a perspective view of the assembled receiver unit. e

`Referring to the figures, and more particularly 10 to'Figures'l, 2, and 3, I illustrate the facsimile receiver mounted on a cast iron base I0. A motor II supplies the continuous drive for the operation of the scanning unit. Motor II .is preferably a constant speed direct current motor for l5 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 oper/ation is assured. 20

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 motor II close to the predetermined value over a relatively 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 I3 extending from the 30 motor. By adjusting the position of the friction pad Il against the disk I5 by means of thumb screw I6, the governor may be set for the prede'- termined speed, which speed will be satisfactorily maintained over many days or even weeks of use. The disk I1, having alternate dark and light markings, is employed to adjust the governor I2 setting to the required speed with the aid of a tuning fork in the manner describedl in my copending application Serial No. 128,920, led 40 March 4, 1937.

I prefer to employ the synchronizing circuits and arrangements disclosed in my Reissue Patent No. 19,575, led May 21, i935 entitled Image broadcasting system and also disclosed in my Patent No. 2,047,863. This synchronizing system employs a synchronizing magnet I8 shown mounted upon motor il by bracket 20; an armature 2| for magnet I8 having a projection 22;

and a single revolution positive clutch 23 co- 50 operatingwith the amature projection 22.

A synchronizing impulse is transmitted cyclically 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 23 to permit the execution of a single scanning line in a manner to-be described in more detail. I have omitted the electrical circuit connections for receiving and producing the rectified impulse at magnet I8 since these circuits are clearly disclosed in my patents above referred to and are not part of my present invention. employ such synchronizing system whereby the accurate phase positioning of each line is accurately determined by means of cyclic synchronizing signals at the transmitter since the continuous sheet recording is more satisfactorily per-` formed by such regular phasing operations. Accordingly, the motor II 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.

Motor II 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 23 thereof. 'I'he sleeve 26 is rotatably supported in the casing 23 of the motor` Il. The driven or interior portion l3l) of the positive clutch 23 is secured to the vertical shaft 21 by a pin 3|. When the clutch 23 is in engaged 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 synchronizingmagnet I8 is energized by the cyclic synchronizing impulse. I prefer to drive the motor I I at a slightly greater speed than the predetermined speed for example, in the ratio of 10*1:100 to insure the disengagement of the clutch before the advent of the synchronizing impulse.

Cams

34, 35 are secured to the top of vvertical shaft 21 and cooperate with the synchronizing cam switch 36 which switch is connected to the synchronizing electrical circuitv (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-.40 which carries the stylus. In the illustrated arrangement, one oscillation comprising a single forward and return movement of the scanner arm 40 is performed during one revolution of the rod 21. A preferable scanning speed for this system is sixty lines per minute correspondingl to cnerevolution per second of the vertically driven shaft 21. A cam 4I is used to execute the desired movement of the scanner arm 40. Cam 4| is connected to gear 42 which meshes with and is driven by gear 38. Cam 4I is rotatably supported on rod 43 which is aiiixed to the base I0 in bushing 44. A cam follower 45 is actuated by the cam 4I. The follower 45 is connected to the vertical rod 46 which in turn is directly connected to the electromechanical recording unit 41. 'I'he cam and oscillatory motion mechanism 4I 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.

The base 43 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

I prefer to scanner arm 40 is secured to the magnetic casing structure of the recording unit 41. Arm 45ex tends from the magnetic unit 41 to the record sheet 5I 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 5I in a manner to be described. 'I'he stylus is oscillated against the record sheet 5I in accordance with facsimile signals. By maintaining synchronous movement of the scanner arm 40 and by proper advancing or feeding of the record sheet 5I, line by line past the scanning position, accurate reproductions are readily made thereon. 'I'he stylus point 53 is preferably made of steel to resist wear. A heater coil 54 is wound at the stylus tip. 'Ihe 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 the recording operation. The record sheet 5I in my preferred mobile facsimile unit is a colored sheet having a wax coating. 'I'he wax coating is melted along the portions at which the heated stylus 53 operatesagainst the waxed surface. For black-white reproductions I employ a black paper coated on the recording surface 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 5I to reproduce the picture. The continuous record sheet 5I 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.

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 5l which rotates the -presser roller 60 to a degree sufficient to/advance the record sheet 5I 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 40. I prefer to employ sixty lines per inch whereby one inch of the final picture is recorded in one minute.

The record sheet may be independently advanced Ey means of the handlel which operates the rollers 62. The operator may thus advance va recorded portion from the region of the stylus is a perspective illustration of the facsimile rev#` corder unit with the record sheet 5I containing pictures made thereon. The handle 6I is used tb 2,109,109 pivoted on rod ss. Rod ss is supported in bushtified in a conventional manner and introduced to the connection leads 18 of the coils 1|. The coils 1| are arranged concentric with and at opposite ends of the pivoted armature 53 to variably magnetize the larmature and cause it to vibrate between the pole faces 12-12. The pole faces 12 are formed in Atwo C-shaped opposing portions inwardly tapered toward the armature 63. Permanent magnets 13-13 are placed adjacent opposite sides of the pole pieces 12--12 to create a permanent magnetic field across the air gaps including the pivoted armature 53. A1- though my preferred illustration shows permanent magnets 13, it is evident that electromagnets may be substituted therefor to produce the uniform direct current eld across the pole faces 'I'he coils 1|-/-1| are preferably connected in series and the leads 10 for the coils 1| are directly connected to the output of an electronic amplifier for the received facsimile signals.1 The coil 1| may be connected in push-pull relation with a push-pull amplifier output stage or connected to a single tube amplifier output as desired. The single currents flowing through the coils 1|-1I superimpose a variable magnetic iield on the armature 63 and across the air gaps 14 to correspondingly oscillate the armature 53 about its pivotal support 65. The stylus arm 52, pivotally connected at 64 tothe armature 53 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 circuitsto send current through the coil 1| during the dark picture portions, the styllw point 53 will be pressed against the record sheet during such dark portions to melt the wax coating thereon 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 18 on Figure 3 define the end portions of. the scanner arm 4l! 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 mark the record sheet. Accordingly, a black-white 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 amature 53 which controls the movement of the stylus'rod 52 at the end of which is secured the stylus point 53. 'I'he stylus section 53 which is heated by the coil 54 electrically connected to the battery 18, is preferably made of steel toresist wear. The stylus rod 52 is preferably made of very iight material such as aluminum and is also hollow to reduce its mass and inertial reaction.

'I'he scanner rod 52 is slidably supported in bushing at the end of the arm 48 and secured the spring 83. The normal distance of the stylus point 53 from the record 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 relation of the barrel 8| with respect to the pin 64 intake, as determined by the adjustment of screw 84. In 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 41 to' protects the stylus 53 from digging into the sheetl 5| for an especially intense signal.

Figure 9 is a perspective view of the exterior of a facsimile receiver unit. The cable con-- tains the electrical connections for the motor stylus heater coil 54, and the rectied facsimile signals for the recording magnet structure 41.

y The positive reproductions of the transmitted picture are seen on the extended portion of the record sheet 5|. 'I'he case 81'for the unit may have a streamlined and pleasing appearance 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 width requirements are had, the arrangements of the motor and governor may be varied from the illustrated positions without departing from the spirit or scope of the present invention.

Although I have illustrated a preferred embodiment of my present invention, modifications will become evident to those skilled in the-art and accordingly I do not intend to be Hunted except as set forth in the-following claims.

I claim:

1. In a facsimile recording unit the combination of a stylus arm having a. stylus at one end. with means for reciprocating said stylus against a record sheet including a rod armature, pivotally connected to said stylus arm and electromagnetic means for actuating said armature in accordance with received facsimile signals comprising a magnetic pole structure having a substantially uniform eld magnet portion and having an air gap individually cooperating with each end of said rod armature, coilmeans, responsive to said signals for variably controlling said magnetic field to correspondingly actuate said amature, said rod armature being pivotally and centrally supported within said pole structure and between said air gaps; means for moving said stylus in synchronism with the transmitter scanning operations comprising a member secured to said .reciprocating means, and mechanism for oscillating said member; and means for controlling the maximum excursion of said stylus comprising two opposed screw members positioned adjacent the free end ofA said armature, adjustably positionable with respect to said free armature end whereby said screw members abut said armature when said armature vibrates a predetermined degree.

2. In afacsimile recording unit the combination of a stylus arm having a stylus at one end, with means for reciprocating said stylus against aI record sheet including an armature connected to said stylus arm, and electromagnetic means a for actuating said armature in accordance with received facsimile signals comprising a magnetic pole structure having a substantially uniform magnetic field; means for translating the motion of said armature to said stylus arm comprising a hollow tube and a pivot connecting said hollow tube to an end of said armature, the free end of said stylus arm being secured to one end of said tube and positined to hold said stylus adjacent said record sheet; and means enclosed in said hollow tube for adjusting the distance betlween said stylus and said pivoted armature en 3. In a facsimile recording unit, the combination of a stylus with means for reciprocating said stylus against a record sheet including a rod armature connected to saidvstylus, and electromagnetic means for actuating said armature in accordance with received facsimile signals comprising a magnetic pole structure having a substantially uniform magnetic field, and having an air gap individually cooperating with each end of said rod armature, said rod armature being plvotally and centrally supported within said pole structure and between said air gaps and a first and second solenoid surrounding portions of said rod armature and being responsive to said signals for variably controlling said magnetic field to correspondingly actuate said armature; means for translating the motion of said arma.- ture to said stylus comprising a tube and a pivot connecting said tube to an end of said armature to maintain said stylus in a spaced relation-with respect to said armature and adjacent said record sheet; and means for adjusting the distance between said stylus and said armature comprising Aa barrel supporting said tube pivotconnection and secured to the end of said tube remote from said stylus, a spring enclosed in said barrel for mechanically biasing said barrel and tube away from said pivot towards the record sheet and means for counteracting said spring bias and maintaining said barrel in a predetermined relation with respect to said pivot. i

4. In a .facsimile recording unit, the combination of a stylus with means for reciprocating said stylus against a record sheet including a rod armature connected to said stylus, and electromagnetic means for actuating said armature in accordance with received facsimile' signals comprising a magnetic pole structure having a substantially uniform magnetic field, and having an air gap individually cooperating with each end of said rod armature, said rod armature being pivotally and centrally supported within said pole structure and between said air gaps and a ilrst and second solenoid surrounding portions of said rod amature and being responsive to said signals for variably controlling said magnetic field to correspondingly actuate said armature; means for translating the motion of said armature to said stylus comprising a tube and a pivot connecting said tube to an end of said armature A to maintain said stylus in a spaced relation with respect to said armature and adjacent said record sheet; a bracket secured to said structure containing means for slidably supporting said tube; means for moving said stylus in synchronism with the transmitter scanning operations comprising a member secured to said reciprocating means, and mechanism for oscillating said member; and means for adjusting the distance between `said stylus and said armature comprising a'barrel slidably supporting said tube pivot connection and secured to the end ofsaid tube re- Imote frm said stylus, a spring enclosed in said barrel for mechanically biasiiigsaid. barrel and tube away from said pivot towards the second sheet, and screw means for counteracting said spring bias and maintaining said barrel in a predetermined relation with respect to said pivot.

5. In a facsimile recording unit, the combination of a stylus with means for reciprocating said stylus against a record sheet including a rod armature connected to said stylusland electromagnetic means for actuating said armature in accordance with received facsimile signals comprising a magnetic pole structure having a substantially uniform field magnet portion and having an air gap individually cooperating with each end of said rod armature, a pin passing through the central region of said armature for pivotally supporting said armature within said pole structure, and a iirst and second solenoid surrounding opposite end portions of said rod armature and being responsive to said signals, for variably controlling said magnetic fleld to correspondingly actuate said armature; means for translating the motion of said armature to said stylus at substantially right angles with respect tothe armature movements comprising a tube anda `pivot connecting said tube to an end of said armature projecting from said structure, to maintain said stylus in a spaced relation with respect to said armature and adjacent said record sheet; a bracket secured to said structure containing means for slidably supporting said tube; means for moving said stylus in synchronism with the transmitter scanning operations comprising a shaft secured to said reciprocating means, and mechanism for oscillating said shaft including a cam; vmeans for adjusting the distance between said stylus and said armature; and meansfor controlling the maximum excursion of said stylus.

` WILLIAM G. H. FINCH.