US2489691A - Engraving facsimile system - Google Patents

Description

C5 Sheets-Sheet l G. WASHINGTON, JR

ENGRAVING FACSIMILE SYSTEM ATTORNE Nov. 291949 Filed Feb. 8, 1947 G. WASHINGTON, JR

ENGRAVING FACSIMILE SYSTEMl Nov. 29, 1949 3 Sheets-shewl 2 y Filed Feb. 8. 1947 INVENTOR. @50H65 WASH/N@ iTo/vJ/.

ATTORNEY Nov. 29, 1949 G. WASHINGTON, JR

ENGRAVING FACSIMILE SYSTEM Filed Feb. 8, 1947 5 Sheets-Sheet 3 .l n n INVENToR.

` 50H66 MASH/www Jh; 13%,( M ATTORNEY Patented Nov. 29,

George Washington, r., Morristown,

Application February-s, 194i; serial Noz-7275407? This;` invention". relates to machine for," making printing.. plates'. and`l mats.:

printing :press matrices,

repr

for

ai method and .oduction's, such as use 1 in... forming-1v directly` from a picture,

form'letter, map, drawing, etc'., anfordinaryfblack and; white o Such aimachine is dis.-

graph-'aor transparency; closed-2'y inmy. Patent November?, 1939..

VAsfset forth insaid pat decomposing tool for ma The. decomposing. tool. forms ai printing. plate..

ent, thereis provided a kingl impressions inv a y as wellr as from. r' colored photo# 179,002, granted large'inumber. of impressions at high'. speed in the; printing. plate,

picture.l

These Varying; light'. and.'A shadowiA counterpar It will; be readily f understood.

methodof ,f repro integrity.'r upon .the pressions so that ducing alpicture: depends for its` uniform spacing of the im'- the only variable introduced..

the. 'depth` of the. impression being a function of the opacity of the original depths thus form.. the ts ofthe' picture.

that` the 1 above'.v

is the depth rof impression.. If,.in addition, .the

points ofimpression wereunequal spacingA would introduce asecOnd Variablelwhiclrwould seriou tion-,..because the unequal spaci a shader. wai/e pattern picture.y

sly;v affect: the` reproducng;;would'. provide throughout the reproducedpicture whichis not .part .of the original Such unequal. spacing would i obscure placesf that shouldbe-- clear. andi would. provide clear spaces forfportions that shouldbezobscure. Thexequal spacing of thev vpoints1of .impression is thus.. ai' highly?. desir able, .fundamental..object in any'freproduction systemrof this type...

Ita isc. therefore i thev pr invention'. to provide a.

insuring equal spacing. o sion throughout the area o Itfisistill another obj impression regar incipal 1 object' y ofi this method-J and..Y means? for ect of f'. the points of. impresi picture reproduction.. 'this invention tov provide means forfequally. spacing thepoints of.

dless of; the; relative speed of..

operation of .the impressingutool. ori of the i. care riagesfuponwhich the' original reproduction are vvmounted.'A

Still other objects and.'v

invention'` will: becomesapparent detailed.descriptionrthereo Infath'e'. accompanyingt-V with .ipa

Fig. V.1 .is a plan view,A disclosingv an assembly o fthem advantages of'. this pictureiand @the "in the following.-

drawings.'

rts broken Law-ay, echanism consti'- tuting'fone form of my invention.

Eig: .2 .is .awiring diagramof a 'mixerramplier employed. in vthe aFig. 1 device..`

VFigxA ris; an'end view offthe;impressionv spacing control member, only a few of 2 shown. andai they remainder: off the A teethL being? indicated diagramm'atically?.`

' rlfisiaiside.elevation, partly.' sectioned Vertically,zof1thefFig; 3.. device..

Rigs.. 5F and@ 5Ai are theteeth .1inbthe two-limiting position.- l

'Ehemechanism'. which@l is'. illustrated inthe drawingsrandlwhich constitutes one embodiment '.oilv my. invention,..consists. primarily of two f fundamental parts;..nainelyfaifxed 'base-:platef I 0fandlainovabl'e carriage guideslor runners: i Upon i ilithere isimountedffthe :driving mechanism icon-f SSiiffgw'a motori-M1 which-1 rotates .two cylinders-*.5 2 fiandszo. in 11: lirelationshipthrough reduction gearingasuchiias that'containedr in .reduction gear boXiiZ'l i and. driving: .apair.

andi Z-EBL, shaitss.' 24, `251" ported.' onlbaselplfate'. i021 additionally supported'l ati bracket` 125| also .flxedtonthe.base-'platey l ll;

The pictureapri'ted m'atteri-'or' other-1 transf lucent 'representation cylinder 20 and heldclamping means (not shown) andi theprinting plate@ arev journalled 'inl bracket 26 i supshow'nn. Th'e reproduction upon the iprinltplate or matrix case.I isablack fand .whitetransparency,- vis per# formed asiollow'sz For: this1purpose thecylin:v

.der-r "iii-Sis". at hollowI 'transparent cylinder;` preier- .aS-beam o lightisl designedflto.: bei reflectedvlthrougli the. wallfof the. to the' surfacefoi theutransparency: 30.' so'thatfthefamount oi Slightlvvhioh..passesthroughH theiftransparency"willtvary in I'v accor the op'acityfv oi that'.point;-V For. thisA purpose,V` thereiis..mountedluponthecarriage H a .source offlliglitLl. provided with.y an voptical-.'system- 31 a i.beam-!oi` lighty to Lbe thrown ablyfofglass, as shown; and.

cylinder."

designed Lto `cai'ise uponf condenser lens 3 2,. which@ converges fthe beam -uponlfa mirrorlxedfiin a'sleeve 34 slidiable'I within theC hollow f cylinder! 2.0. sleeve 311 is provide'dthroughliwh-ichwthe. reflected:beaml of light'.may.l

fpassf. The optical. system' is :suchthatv the ".beam'.

of light is focused:.ati35'uponfitheff:transparency. 391B transparency? depends upomtransparency fat that point. and ftherzquantityn of light.sordeterminedvis fcausedixto :bei: transmittedl .two. enlarged .views of a# portion of the? .controll member; of l Figi-3 showings Ii. mounted'. to' slide fon '1 vthe fixed .b ase-plate The lshaft 25.. may be. its@- opposite endinl- 30.2 is .wrapped around the thereon-1 by." any suitable.

is-wrappedlaroundeylinder 2U!- andr iiiied` thereonby any: suitable :clampingv means-A (n'ot' of. thepicture 3315 3'0",y .whichliinlthis Thefamount of.Y light"v passing: l through the.. the opacity; of ther.'

into a lens system 31 where, by a suitable optical system, the light is focused upon a light-sensitive cell 38 to vary the amount of current which passes through the cell. This current after passing through a mixer amplifier (to be described more in detail hereinafter) is suitably amplied by any standard ampliiier and may be caused to operate a dynamic unit 29 as shown in Fig. 1 to cause the armature 39 thereof to be repelled to a greater or less extent to cause an engraving tool in the form of a needle or tip normally lying closely adjacent to the surface of the print plate or matrix 3U' to be pressed into said print plate to a greater or less degree depending upon the quantity of light that has passed through the corresponding point of the transparency 30. The position of tool 40 may be controlled by adjusting the dynamic unit which is mounted on the carriage on guide rods 29' for movement toward or away from roller 2D'. The dynamic unit may be fixed in position by any suitable clamping means (not shown).

Tool 4e may be a cutting tool or a compressing tool, but I prefer to provide means whereby the tip 40 actually destroys the material of the print plate to a greater or less degree, depending upon the degree of movement of tool 4U into the print plate. Such destruction is preferably accomplished by heating the tool 4D in conjunction with the proper selection of material comprising the print plate 36 so that said material will be destroyed by heat. Thus I have provided a heating coil 4| supplied with current from any suitable source of current, to cause the said tool 4l! to be maintained at a temperature cf at least 600 or 700 degrees. The material comprising the plate 30 may be any kind that will be decomposed by heat, and for this purpose a nitro-Celluloid matrix hasbeen found satisfactory. The point 43 of tool 40 is conical, tapering toward the print plate, so that the degree to which the said point enters the matrix will control the amount of material which is decomposed and removed. There is thus formed in the plate a depression whose depth and surface area are functions of the amount of light which has passed through the corresponding point of the transparency 3B.

It will now be apparent that if the light from light source L can be caused to scan the surface of transparency 30, and the cone tip 43 can be caused to remove material at corresponding points on print plate 30 in proportion to the light passing through transparency 30, there will be obtained upon the printing plate 30 a reproduction of the picture or image on the transparency 3U. It will, of course, be appreciated that the greater the number of points and the closer they are located the better will be the reproduction on the print plate 30. For accomplishing this result, I provide means for causing the spot of light 36 to traverse a spiral path of very ne pitch completely covering the surface of transparency 3|). The spiral path of light-spot 36 is effected by causing the carriage upon which the source of light L, optical system 3| and sleeve S4 with its optical systems 32 and 33 are mounted, to be moved in translation while the sleeve 34 is rotated. The translatory movement of carriage upon baseplate Hl may be effected from reduction gearing 2| driving through gears 22, 23 to further reduction gearing 44, 45 to rotate shaft 46 journalled within the standards 26 and 2'|, to rotate a Worm 41.. The said worm is threaded through a bearing 48 fixed to the carriage so that as the worm rotates the carriage is moved in translation. The carriage thus carries sleeve 34 in a linear direction within the hollow cylinder 2t. The dynamic unit and the tip 4t being supported on carriage il are moved correspondingly in translation.

At the same time that the sleeve 34 is being moved in translation, the cylinder 20 is being rotated, as hereinbefore described. Therefore the point of light 35 traverses a spiral path on the surface of transparency 30.v At the same time the tool 4t moving in translation and the cylinder 20' rotating, causes the tool to traverse a spiral path relative to the print plate 3S' in synchronism with the spiral path traversed by point of light 36.

The light which issues from light cell '38 is thus continuous, varying only in intensity. If this light were received uninterruptedly by dynamic unit 29, the decomposing tool 49 would trace a continuous helical line and thus provide nothing more than streaks. In order that the picture may be reproduced it is necessary to interrupt the varying current delivered to dynamic unit 29. Such interruption must occur at a frequency which is high relative to the frequency of rotation of the cylinder 2t', for example, of the order of 600 cycles per second and, furthermore, such interruptions must be so controlled that the impressions made by tool 40 will be equally spaced around the circumference of the printing plate St for the reasons noted in the introduction hereto. Such equal spacing-of impressions becomes a serious problem in the face of variations in speed of the cylinders 2i! and 28. Therefore, I have provided the following solution for this problem:

Upon one end of shaft 25 of the cylinder 20' which carries the printing plate 3D', I provide a metallic disc 5B whose periphery is notched to form a large number of teeth 5|. All of the notches (and, hence, also the teeth) are of exactly the same length and depth and are spaced apart exactly equal increments of linear distance along the periphery of the disc, and, hence, are spaced apart equal angular distances relative to the center of the disc. The disc 50 is concentrically positioned with respect to a fixed, metallic annuius 52 whose inner periphery is similarly notched at equal angular distances with respect to the center of disc 5o to provide the same number of teeth 53 as there are teeth 5|. Furthermore, I form disc 5S and annuius 52 as the two plates of an electric condenser so that the capacity of said condenser will vary from maximum when the teeth are in alignment as shown in Fig. 5, to minimum when the teeth are completely out of alignment, as shown in Fig. 5A. By providing an electrical system whereby current will be delivered from light cell 38 to the dynamic unit 29 only when the teeth 5l and 53 are in alignment to yield the maximum capacity, I provide a system whereby the decomposing tool 4@ is actuated each time disc 5i) has rotated an angular distance equal to the distance between adjacent teeth. Thus, it will be seen that tool 40 will make as many impressions in the printing plate Bil per revolution of cylinder 2li as there are teeth on the periphery of disc 56, and on the internal surface of annuius 52. Thus the number of actuations of tool 4G per revolution of cylinder 20 is constant and the spacing between adjacent impressions is necessarily constant regardless of the speed of cylinder 2t or variation in such speed since the actuation of tool 46 depends only upon the angular displacement of disc 50 and not upon rate of motion.

For Vaccomplish-img theaborenfesulh;:reference may `be :had to Figa wherein Yit,-vszill)ber/seenthat ylight cell 38 is ,continuously-fl applying `*its vlvoltage to .the second Ygrid lill of ari-electron tube' lwhich has an anode 6.2, et-.cathode 53 andra.' suppressor gridv t4. The variations in voltage. .zappliedfto the second gridwll do notresult in anfoutput-rom the plate 62 because .ofetheY-.biasnormally placed upon the rst -grdv 65 which is ,in electriccommunication with the condenser "f5.0, ,152. However, when Vthe `.teetlilfofdisc511 are in alignment with the teeth of annulus 52 the first grid 65 is biased sufficiently :in the `proper direction to permit .an output from the plate 62. Therefore current of an intensity determined by .thel current output of light cell 38 at that'part'icular instant will pass out :of the 'mixeramplifier and after being amplied by theY power amplifier will be applied to the dynamic -unit 29 and decomposing tool 4,0. As soon as theteeth moveout of full alignment, tube 6I again becomes nonconductive yand the currentisfshut oi until .disc 55 has moved through an angular distance sufcient to bring its teeth again in alignment with the teeth of the annulus 52.

Thus absolutely equal spacing between impressions on printing plate 30 must result since they are controlled only by the angular displacement of disc 50 relative to annulus 52 and this angular displacement is independent of any variations in speed.

As shown in the sectional part of Fig. 4, the elements 50 and 52 forming the condenser plates are metallic. The annulus 52 may be supported on bracket 10 from which it is insulated by suitable insulation 1|. The bracket 10 is xed to the base plate l and may also support an additional bearing for the shaft 25.

The foregoing description of the invention is merely illustrative and changes may be made within the scope of the appended claims.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. A device for making printing plates directly from a subject to be reproduced comprising; means for scanning the subject with a beam or" light, a light-sensitive cell in the path of the beam of light, a rotatable cylinder, a printing plate carried by said cylinder, an image-forming tool normally disposed in inoperative position with respect to the printing plate, means for relatively moving the printing plate and the tool to scan said printing plate in synchronism with the subject scanning means, a variable condenser, means for cyclically varying the capacity of the condenser throughout a plurality of cycles for each revolution of the said cylinder, pulsing means controlled by the condenser for rendering the said tool operative with respect to said plate only during preselected values of the cyclically varying capacity, and means for causing the tool to make an impression in the printing plate in response to the quantity of light striking the light-sensitive cell when the pulsing means renders the said tool operative with respect to the said plate.

2. The invention as recited in claim 1, wherein the condenser comprises, a metallic annulus having a plurality of spaced teeth, a metallic disc concentric with said annulus and having a pluraltiy of similar teeth corresponding to and spaced from the teeth on said annulus, and means electrically insulating the said disc from said annulus.

3. The invention as recited in claim 2, wherein s to block conduction the-saddisc and the :plate-.carrying cylinder are secured #to a common shaft.

A vdevice for making printing plates directly from afsubject to be reproducedcomp-rising; ya rotatable cylinder carrying the subject; a light beamcooperatingwith the said subject; means for causing said llight beam to traverse a helical path to scan the subject; a light-sensitive cell in the path of the light beam; a second cylinder and a metallic disc affixed to a common rotatable shaft, said disc having a plurality of spaced teeth; a printing plate carried by the second cylinder; a metallic annulus concentric with the said disc and rhaving a plurality of teeth corresponding to and spaced from the teeth on the said disc; means electrical-ly insulating the disc from the annulus; an image-producing tool; means for relatively moving the printing plate and the toolto scan the said plate in synchronism with the light yscanning means; means for causing the tool to penetrate the printing plate in response to the quantity 'of `rlight falling .on the light-sensitive cell; and means effective to prevent the tool from penetrating the printing plate when the teeth on the said disc and annulus are out of alinement.

5. A device for making reproductions on printing plates directly from a subject to be reproduced comprising, means for scanning the subject with a light beam, a light-sensitive cell producing electrical variations in accordance with variations in the light beam, a rotatable cylinder, a printing plate carried by said cylinder, an imageforming tool, means for relatively moving the plate and the tool in synchronism with the light beam scanning the subject, an electron tube having an anode and a plurality of grids cooperating with a cathode, an output circuit connected to the said anode, a first control grid normally biased between the cathode and the anode, a disc rotatable with said rotatable cylinder said disc having a plurality of teeth, an annulus having a plurality of teeth corresponding to and spaced from the teeth on the disc, means electrically insulating the disc from the annulus, circuit elements connecting the disc and annulus between a voltage source and the first control grid of the electron tube to produce a pulsating flow of current in the said output circuit as the teeth on the disc and annulus move into and out of alinement, circuit elements for impressing the electrical variations produced by the light-sensitive cell upon a second control grid to thereby modulate the amplitude of the current which flows in the said output circuit, and means for causing the tool to penetrate the plate in accordance with the modulated current liowing in the said output circuit.

6. A device for making printing plates directly from a subject to be reproduced comprising, means for scanning the subject with a light beam, a light-sensitive cell in the path of the light beam, a rotatable shaft, a cylinder secured to the rotatable shaft a printing plate carried by the cylinder, an image-forming tool normally spaced from the printing plate, means for relatively moving the printing plate and the tool to scan the said plate in synchronism with the subject scanning means, a metallic disc secured to the said rotatable shaft and having a plurality of circumferentially-spaced teeth, a metallic annulus concentric with the disc and having a plurality of teeth corresponding to and spaced from the teeth on the disc, means electrically insulating the annulus from the disc, tool-operating means, means for causing the tool-operating means to impart an oscillatory movement to the tool toward and away from the printing plate as the teeth on the said disc and annulus move into and out of alinement, and means for modulating the amplitude of the said oscillatory movement of the tool to cause the tool to penetrate the printing plate in response to the variations of the light striking the light-sensitive cell.

7. In a picture reproducing device of the character wherein an image-forming tool is adapted to penetrate a printing plate in accordance with variations in a beam of light scanning the subject to be reproduced, the combination of a rotatable shaft, a cylinder secured to the shaft, a printing plate carried by the cylinder, an image-forming tool normally disposed in inoperative position with respect to the printing plate, tool-operating means for moving the tool toward the printing plate to render the tool operative with respect to the said plate, a disc secured to the rotatable shaft and having a plurality of spaced teeth,

an' annulus concentricwith the disc and having a. plurality of teeth corresponding to and spaced from the teeth on the disc, means electrically insulating the disc from the annulus, and means controlled by the said disc and annulus for periodically actuating the tool-operating means to render the tool alternately operative and inoperative With respect to the printing plate as the teeth on the disc and annulus move into and out of alinement.

GEORGE WASHINGTON, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,063,614 McFarlane et al. Dec. 8, 1936 2,079,970 Speed May 11, 1937 2,175,388 Gurley Oct. 10, 1939 2,180,397 Carlisle Nov. 21, 1939

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