US3749015A

US3749015A - Apparatus and process for printing

Info

Publication number: US3749015A
Application number: US00067839A
Authority: US
Inventors: A Leatherman
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-11-09
Filing date: 1970-08-28
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31

Abstract

A printing method and apparatus employs a high frequency magnetic through-field of high strength for effecting permanent lodging of pulverized magnetic particles on ordinary paper in a simple one-step operation. The strength of the magnetic field is several times the value required for simple transfer deposit of magnetic particles. The field is concentrated by use of an edged field plate to facilitate providing the desired field strength. Numerous embodiments for practicing the invention are disclosed.

Description

United States Patent 1 1 3,749,015 Leatherman [4 1 July 31 1973 [54] APPARATUS AND PROCESS FOR PRINTING 2,716,826 9/1955 Huebner 118/625 46 74 MP [75] Inventor: Alfred F. Leatherman, Columbus, 23:11a a X Ohio 3,392,667 7/1968 Cassel et 31.. 101/010. 13 2,302,179 11/1942 Bronfman 101/288 X [73] Assignee: William C. Heller, Jr., Milwaukee, 2,495,389 1/1950 Sammann 101/288 Wis. 3,526,708 9 1970 Leatherrnan 101/DIG. 13

OTHER PUBLICATIONS [22] Flled' 1970 Houston et al., Magnetism, Elementary Elec- [21] Appl. No.: 67,839 I tro+Technical series, W. J. Johnston Co., New York, V 116161611 U.S.Application Data" 1 7 1 Dwsi of set N6 506 960 Nov 9 1965 P t N Bardell, Magnetic Materials 1n the Electrical Indus- 3 5 1 1 1 try, MacDonald & C0., London, 1960, p. 47, 48.

52 us. (:1. 101/426, 101/010. 13, 346/74 MP '7' Pulfrey Asszstant Exammer-R. T. Rader [51] Int. Cl B411 35/00 58 1 Field 61 Search 95/1, 7; 96/1; Ammey'fEugene 93.44; 118/620, 621, 623 625, 637, 640; 1 71 ABSTRACT, 346/74 MP; 426, 288v 227, A printing method and apparatus employs a high frel3 156/390 quency magnetic through-field of high strength for effecting permanent lodging of pulverized magnetic par- [5 6] .Rderences C'ted ticles on ordinary paper in'a simple one-step operation. UNITED STATES PATENTS The strength of the magnetic field is several times the 2,297,691 10/1942 Carlson 95/5 value q d for imple ransfer deposit of magnetic 3,279,367 10/ 1966 Brown 346/74 MP particles. The field is concentrated by use of an edged 3,161,544 12/1964 I Berry 118/637 field plate to facilitate providing the desired field 3,245,341 6 C ess et al- 1 15 X strength. Numerous embodiments for practicing the in- 6 Edwards et aL X vention are disclosed 2,661,289 12/1953 Mayo et a1 156/390 2,033,991 3/1936 Melton et a]. 118/623 14 Claims, 19 Drawing Figures 2,721,821 10/1955 Hoover 101/426 X 3,355,743 11/1967 Capps 346/74 MP 3,389,398 6/1968 Engstrom et a1 101/1 POWER Su P P 1. v 7

PATENTED 3 l POWER SUPPLY sum 1 OF 5 INVENTOR ALFRED LEATHERMAN BY $9M? ATTORNEYS PATENIEU JUL31 191a sum 3 or 5 .mw mm MHQM T R mm m F D? E R F L A m PATENIEflJuLal m 3.749.015

SHEET 0F 5 INVENTOR ALFRED F'. LEATHERMM 7 BY I ATTORNEYS PATENTEUJUL?" 3,149.01 5

SHEET 5 0F 5 INVENTOR v ALFRED FLEATHERMAN ATTORNEYS tion and so forth.

Technical progress of recent years has seen the development ofmany printing and "reproduction techniquesthat have considerably broadened the original work of Gutenberg. Methods finding modern favor offer processes that are dry, fast, and economical.

The formation of marks and written characters has received considerable attention in recent decades and some processes have been developed to relatively advanced points. Among the handicaps to any printing or impregnating process is that if the process is wet, a drying stage must be incorporated. If dry, a means must be found for melting by heat, hammering, softening by vapors, orotherwise causing the powders to become fixed to the papenplastic, etc. These treatments normally must be carried out after forming the mark, and therefore special care is required not to smudge or disturb the pattern. This requirement can call for appreciable consumed time and/or space in the process. Disadvantages of time and cost are also involved if it is necessary to apply heat to the otherwise finished material to accomplish fixing. f

It is apparent that wet or dry printing or impregnating processes of the past have met with considerable disadvantage. One process that has been used for certain printing or coating tasks to overcome some of the disadvantages of the prior art is the electrostatic process.

Several problems arise in the area of electrostatic processes. Large black areas are not always amenable to reproduction capable of distinguishing these black areas from the background. The electrical insulation characteristics of paper and plastics permits such things as latent images in electrostatics but also cause distortion of the electric field to produce distorted copy. Handling of the materials, or operation of the machinery, also can produce electric charges by friction at undesired places possibly resulting in background problems. Atmospheric humidity may have an adverse effect on the operation of electrostatic methods. Some electrostatic methods require sensitive image plates and other fragile devices that can become scratched and worn with direct adverse efiects on results. In addition, electrostatic equipment requires higher voltages than that available from ordinary transmission lines.

It is an object of this invention to providemethods for printing wherein printing is doneinstantly by application of a magnetic throughfield.

It is another object of this invention to provide methods for printing wherein printing is done upon a carrier that-is contacted with the copy .to transfer the pattern to the copy.

It is still another object of this invention to provide a process for reproduction of printed matter wherein the detail of the light and dark areas of the original is defined accurately on the copy.

It is yet another object of this invention to provide apparatus for printing or impregnating that are not dependent on electrostatic or magnetic image plates or other fragile elements.

These and other objects and advantages of the present invention will become more apparent to those skilled in the art from the following detailed description and claims taken in connection with the accompanying drawings, wherein like components in the several views are generally identified by like reference marks, in which: 7

FIG. 1 is a schematic diagram of a magnetic printing device using a carrier for transfer of the magnetic pattern formed;

jiFIG. 2 is a schematic diagram showing thecarrier of FIG. 1 being applied to print the surface of a bottle;

FIG. 3 is a schematic diagram showing the bottle to be printed moving to the carrier;

FIG. 4 is a schematic diagram in whicha film on the carrier contains the magnetic pattern and is then applied to the bottle;

FIG. 5 is a schematic diagram in which an induction heating element is disposed in the air gap adjacent the carrier;

FIG. 6 is a schematic diagram, top view, in which the carrier is of stainless steel and can be supported by conductors for heating the carrier and magnetic pattern;

7 FIG. 7 is atop plan schematic diagram using a rotary magnet and carrier to provide for separate steps of cleaning, forming the magnetic pattern, and printing;

FIG. 7A is an enlarged detailed view of a portion of the apparatus shown in FIG. 7 in the position generally indicated by III;

FIG. 8 is a vertical schematic diagram of another embodiment of this invention using an arrangement of apparatus for magnetic printing comprising a belt and a web of paper or other material on which it is desired to print; 0

FIG. 9 is a vertical schematic diagram of a further embodiment in which a drum is used to form and carry the magnetic pattern to print on receiving means such as a paper web;

FIG. 10 is a schematic view partly in cross section of an arrangement of apparatus for magnetic printing using a flexible and expansible carrier for the magnetic particle pattern;

FIG. 11 is a view similar to FIG. 10 showing application of the flexible carrier to an object having an irregular surface;

FIG. 12 is a view similar to FIG. 11 in which the carrier has a rigid or semirigid backing member;

FIG. 13 is a schematic view partly in cross section of another carrier for magnetic printing and involving the use of an elastomeric of flexible material having a rigid or semirigid backing member;

FIG. 14 is a view similar to FIG. 13 showing the application of the carrier to an object having an irregular surface;

FIG. 15 is a perspective schematic view of an arrangement of apparatus utilizing photo-sensitive devices for reading material to be reproduced and a plurality of magnetic cores for scanning a carrier to collect a magnetic pattern for deposition of the pattern on an object such as a bottle;

FIG. 16 is a partly perspective and partly top plan schematic view of an arrangement of apparatus similar to FIG. 15 but in which a plurality of objects such as bottles are magnetically printed at one time from asingle original;

FIG. 17 is a top plan schematic arrangement of apparatus for developing several different colors on a carrier and then applying the composite magnetic color to anobject such as a bottle;

FIG. 18 is a top plan schematic view of an arrangement of apparatus for magnetic color printing on an object where the object is printed with different magnetic colors in three different steps;

FIG. 19 is a top plan schematic view of an arrangement of apparatus for moving the object to be printed in FIG. 18.

In the method of the present invention the printing operation-can be accomplished from one side of the material. For example, printed information can be applied to closed packages, solid objects, containers with small necks, etc. Preferably, the apparatus is arranged to avoid contact between the magnetic character forming face and the magnetic particles to avoid the necessity for cleaning the magnet face and to insure the application of more uniform pressure to the body being printed.

As shown in FIGS. 1 to 3, the object or product 82, such as polyethylene milk bottle, to be printed upn is of a rigid or semi-rigid type or can be momentarily pressurized with air or filled to make it so, and is held in position by conventional apparatus. A thin strip of metal, plastic, or other suitable material 83 that can be called a carrier, is positioned vertically between object 82 and magnetic field source (magnet 84) and outfitted with mechanical equipment to hold it in the desired position. Carrier 83 is made of austenitic stainless steel, Teflon, rubber, plastic or other nonmagnetic material that will not disturb the magnetic flux lines. The carrier can be rigid or flexible, taut or slack, and flat or contoured to match 'a product surface. The magnetic field source 84 carries a letter, symbol or other indicia on its face adjacent carrier 83. The field source 84 is energized by means of a coil and power supply, providing a direct current, alternating, or; oscillatory current flow, in one of several manners as previously described.

Between carrier 83 and product 82, a cloud, shower, spray, or curtain of suitable dry magnetic powder 86 from supply container 87 is maintained either continuously or intermittently so as to supply the ink" (magnetic particles) to the system.

Upon energizing the power supply and establishing a magnetic field in field source 84, some of the powers of cloud 86 are attracted toward field source 84 and become collected in an organized manner against the surface of carrier 83. Next, carrier 83 is moved rapidly to cause it to press against object 82 as shown in FIG. 2. The amount of carrier motion required will depend on the dimensions of air gap 88 of FIG. 2 and can be quite small for rapid operation. The carrier can be moved by means of fluid (air or liquid) actuated cylinder 880 having piston rod 88b bearing arm 880 connected by lip 88d to carrier 83. The organized pattern of particles on the carrier can be held in place by natural adhesion or by maintaining the energization of field source 84 during the motion of carrier 83. Alternatively, object 82 can be moved rapidly against carrier 83 containing the organized pattern of particles to press the particles against the object as clearly shown in FIG. 3. Here, fluid actuated cylinder 88a containing piston rod 88b is connected to arm 88c which accordingly can move bottle holder 88c which can be part of a bottle conveyor system.

With members in the positions of either FIGS. 2 or 3, the organized pattern of particles is transferred onto the product by several possible techniques. For example, where the surface of the object 82 has been previously prepared with a tacky coating in the area to be printed upon, the organized pattern of particles will stick to object 82 upon return of

members

82, 83 and 84 to the open" position of'FIG. l, completing the cycle of a printing operation. In a modification of this approach as shown in FIG. 4, a visibly transparent or translucent film 89 contacts carrier 83 on the side opposite field source 84 prior to formation of the pattern of magnetic particles. The film is held and supplied by means known in the printing art. On energization of field source 84, magnetic particles 86 will form an organized pattern on film 89 held against carrier 83. Carrier 83 then moves to object 82 or vice versa'as shown in FIGS. 2 and 3. Film 89 having the organized pattern of magnetized particles then sticks to the tacky surface of object 82 upon being pressed against it by carrier 83, to result in a waterproof, smooth, protective cover for the final copy if desired. Such a film, desirably pre-cut, could instead be applied as a subsequent step if desired, and might be sprayed or applied by curtain coating as known in the packaging art, or the film could be cut at the time it is applied to the product. In a further alternative, a pre-gummed film is placed on carrier 83, the gummed side positioned to receive the organized pattern of magnetic particles. The pattern is then formed on the gummed surface which gummed surface then also serves to hold the film in place on object 82, which no longer would need to be pre-gummed itself. In the approaches just discussed, carrier 83 does not need to be made of any particular material so long as it does not disturb the magnetic flux lines. It could be metal, plastic, cloth, wood, ceramic, etc.

In using a pre-gummed film (89) or pre-gummed object (82), it is preferred to employ one or more shutters in the air gap to avoid formation of background on the film or object from the cloud of particles before the field source has formed and organized the particles into a pattern on the carrier or film. The shutters are supported in a manner to move in and out of the air gap so that they are placed in operating position during formation of the cloud and organized pattern and then are moved out of the air gap when the carrier 83 or object 82 are moved to transfer the pattern to the object 82. Alternatively, the particles 86 can be injected into the air gap parallel to but positioned away from the carrier 83 and film 89 as well as object 82 with the simultaneous energization of the field source. In this way premature adhesion of the particles to the pre-gummed film and/or object can be avoided.

With carrier 83 constructed of an electrical nonconductor which also does not disturb flux lines, having a smooth surface and capable of operation at elevated temperatures such as a polytetrafluoroethylene material marketed under the trademark TEFLON" by E. I. du Pont de Nemours and Company, a coating of such material, silicone rubber, or resin coated fiberglass, the organized pattern of magnetic particles may be pennanently printed as follows. With the previously discussed members in position, as in FIG. 2, an induction heating coil is introduced into air gap 88 to provide the arrangement shown in FIG. 5 in which induction heating coil 91 is shown in a representative position for use. Induction heating coil 91, of course, is connected to a suitable well known induction heating power source not shown. Fluid actuated cylinder 91a contains piston rod 91b connected to arm 91c supportingcoil 91- to move the coil in and out of the air gap for the purposes of heating. Using the desired combinations of magnetic particle types and frequency of induction 'heatingenergy, rapid controllable rates of heat generation can be provided directly in said particles. Thus, upon.energizing induction heating coil 91, heat is generated -in,.a'nd only in, the organized pattern of particles themselves which are pressed against object 82 by earrier'83. Further'pressure can be achieved, if desirable, by arrangrial such as polyethylene, polyvinyl chloride, or other suitable material, the generatedheat will soften'and/or partially melt the surface of object 82 selectively at the desired regions exactly at the areas of the pattern, causing the plastic to flow or soften and form a bond with the particles or permit the particles to become embed ded in the surface.. Then, induction coil 91 is deenergized permitting the printed surface of the product to return-to the'solidified state. If desirable, the induction coil 91 can be cold waterjcooled and when resting against the rear face of the .carrier can assist this cooling action. Alternatively, cool air blasts can be used, or the cooling can be done in a subsequent step if necessary. However, in some instances upon de-energizing the coil, cooling will occurvery rapidly by itself with, or without, the members remaining in place as shown in'the Figures. When carrier 83 is used for elevatedtemperature service, it is made of or coated with materials such as Teflon, silicones and otherswell known in the art which-avoid sticking of the carrier to object 82 when the step is undertaken to restore the various ing forcoil-91 topress against theback of the carrier I, 83. Where 3product82 is made of thermoplastic mateit, before, during, and/or after the particle pattern had been formed on it magnetically. It could also be heated by a gas flame or other source before moving into the magnetic field. Such an arrangement is shown in FIG. 6. The equipment of FIG. 6 is arranged in a manner corresponding somewhat to FIG. 2, but shown in a top view. One or more field sources'94 function to create the initial organized pattern(s) of magnetic particles 86 on the'working face of carrier 96 as before. Carrier 96, however,is outfitted with current-carrying members 97 that can also serve to support and move the carrier. During the process, current is passed through the current-earrying supports 97 and through carrier 96 so as to heat it by' self-resistaneeheating. The pattern-of par-'- ticles containing a hot-melt constituent or coating (colored if desirable) on carrier 96 becomes softened by heat conducted from carrier to particle pattern. The softened particle-pattern is then pressed against rigid or semi-rigid'surface of objects 99 (a bottle as shown) to which it would stick. Carrier 96 can be constructed with a'thin layer of a high temperature resisting nonmembers tothe.open position to complete the pro-- cess or for starting'anew printing operation as shown in FIG. 1. y

With object 82 of-glass, paper, wood, orthe like, a hot-melt or plastic coating preapplied to object 82, or mixed in or coated on particles 86, could be employed to achieve sticking. Hot melt materialmixed in the partieles, or preapplied to the product, also permits permanent marking of metal objects by using induction coil 91 to generate heat in the product as well as particles. In a modification of the method and apparatus shown in FIGS. 1 to 5, induction coil 91 could be eliminated by arranging the members as in FIG. 3 and modifying magnetizing field'source 84 by means of a coil 84a for magnetic flux and a coil 84b for high frequency current to use the source as a magnetic core to channel the generated high frequency flux into the magnetic particles to.heat them. Where the temperature of the field source may become too high due to the high frequencies required for directly heating particles 86 where object 82 is non-metallic, it will be desirable to make the field source of ferrites rather than iron or steel. However, when product 82is a metal, lower induction frequencies can be used'that would sufficiently heat product 82. Thus, use of lower induction frequencies would heat the particlest hot-metal mixture, or soften a hot-melt-precoating on product'82 without overheating field source 84 to require delay for cooling or the use of extra cooling means.

In another embodiment of the present invention, a carrier consisting, for example, of a strip of stainless steel,'-is heated bypassing an electric current through ened. Likewise, the composition of a hot-melt plastic or I resin and magnetic particles should remain on the carrier only sufficiently long to form the pattern which is almost instantaneous and to soften the plastic rather than cause it to meltand run to distort the pattern.

The particles need not contain a hot-melt constituent when printing on thermoplastic products or thermoplastic-coated products. The heat of the carrier can function to soften the outer surface area of object 99 against which it presses, orrests, to cause it to become tacky and to hold the particles .which then become firmlya part of the .object 99upon cooling.

An apparatus arrangement similar to that of FIGS. 1

and 2 was used and comprised a laminated magnetic core with coil windings connected toi a capacitordischarge power source having one pole in the form of a type-face or metal die bearing the number 6.

attached to the core. A non-magnetic polished stainless steel (l7-7PI-I) sheet (0.006 inch thick) was used as the carrier since a magnetic sheet would seriously disturb, .or prevent, the desired pattern since the flux lines of the type-face would tend to spread and flow lengthwise in the sheet. On charging the power supply to 2000 volts and discharging while the stainless steel carrier was adjacent the type-face in the presence of bar rium ferrite particles, the particles were formed in the pattern. of a 6 on the sheet. 0n slightly jarring the sheet excess power could be removed leaving a sharp opaque image. However, it was possible to hold the sheet in any position without affecting the pattern or image, and it appeared that adhesive forces and/or compaction effects among the magnetized or organized particles themselves were holding the pattern in place. The carrier with the pattern on the inside was then bent around a polyethylene bottle without disturbing the the carrier for a few seconds and removed, and the assembly allowed to cool. After cooling, the carrier was removed from the sheet and practically all of the pattern had been transferred to the surface of the bottle. A trace amount of patterned particles remained on the sheet and was removed easily by wiping. While some of the particles on the bottle were loose and could be washed away, a substantial portion remained indented and bonded in the outer surface of the bottle forming a gOOd print which could not be removed without defacing the surface of the bottle.

In another embodiment of this invention a metal or nonmetal carrier 83 could be used with a heated or hot thermoplastic surface of object 82 to cause the particles to stick to the object 82. It is desirable in this instance to assure that some force is established between field source 84, carrier 83 and object 82 to assure good transfer of heat from source to object.

With particles in a hot-melt mixture or with coated particles, the heat transmitted from field source 84 as used above to carrier 83 in FIG. 1 would cause carrier 83 to be warm, thus causing the deposited pattern to become warm and to soften before transferring the pattern. With a pre-softened pattern .such as this, the equipment need not always move into the position of FIG. 3, but can also function as in FIG. 2. The softened pattern does not depend on the product being thermoplastic, or coated with thermoplastic, to achieve sticking so that the method is applicable to marking or printing on board, paper, wood, metal, ceramic, etc.

In a further embodiment of this invention using a metal carrier such as one of stainless steel, carrier 83 is heated locally at the area of the pattern of magnetizable particles and facing the local region of object 82 to be printed upon, by use of induction heating of carrier 83. In one arrangement, field sources 84 would serve as cores of an induction heating coil as mentioned previously in connection with use of this technique for induction heating areas of a metal product. In this particular case, however, carrier 83 would be induction heated locally by virtue of its being present in the concentrated induction heating flux at the active end of field source 84. The induction heating flux can be superimposed on the flux required for collection of the magnetic particles or the induction heating flux can serve simultaneously to collect the magnetic particles in the organized pattern and to heat the carrier (which heats the particles). The induction flux and magnetic collection flux can be established at different, concurrent, or overlapping time intervalsto properly form the organized pattern of magnetic particles and heat them for transfer to and printing or securing them to object 82. 1

As before, locally-heated carrier 83 serves to heat the particles and thermoplastic object or product 82 to make the particles stick as in FIG. 3. For such products or for-products that are not thermoplastic, a hot-melt composite may be used to cause the pattern to become soft upon formation to permit the step of either FIG. 2 or 3 to be carried out. An advantage of this technique is the fact that heat is generated not only locally in the carrier and product but also is generated at all the areas involved in the printing operation.

Since the metal carrier is being heated, the frequency of the induction heating flux may be selected from a broad range because of the optimum (nearly perpendicular) direction of flux with respect to the carrier. Frequencies as low as 1,000 cycles and as high as 500,000 cycles are possible to use. The field sources in such case should preferably be made of a material suitable for high frequency use, such as of ferrite, bonded iron powder, laminations, etc. The field source units of this and previously discussed embodiments can be of sintered or bonded iron powder, obtained by casting or molding to shape. They, also, can be resilient such as magnetic rubber" to help provide uniform contact with slightly irregular surfaces.

A plurality of field sources 84 and accompanying equipment as shown in FIGS. 1-6 can be mounted along a conveyor to print a series of indicia on object 82 as it moves past the various field sources/Alternatively, the pole face of field source 84 facing the object can be smooth and a tape passed in front of it.

A further modification of the present invention to provide faster operation is shown in FIGS. 7 and 7A top views, in which the process is carried out in sequential steps to permit temperatures to rise or fall, to permit particles to deposit and to prevent particles or the cloud of particles from depositing on unwanted areas of the equipment. In the figure, the printing equipment is arranged to rotate counterclockwise in 90 steps. Four steps are indicated by the numerals l-IV.

In step I, type face or field source unit 100 bearing indicia on its pole face is secured by member l0l to rotary shaft 102. Field source 100 is energized by direct current and supply hopper 103 discharges cloud 104 of magnetic particles adjacent the outer face 105 of carrier 106. Due to the energization and resulting magnetic field, carrier 106 collects a pattern of the particles on its surface. The carrier is outfitted with supports 107 which may be current carrying. Natural adhesion forces or a direct current flux component in field source unit 100 now hold the particles in organized position while rotating and while stopped.

In step ll, field source 100 and carrier 106 have been rotated and to the direct current flux of field source (if used) a high frequency component is added to produce induction heating of carrier 106 which heats the particle pattern on the carrier.

In step III, the field source and carrier have been rotated another 90, with d-c and a-c still energized, and the carrier rapidly actuated to move it against the product or object 108 (which may be a polyethylene bottle, for example) to press the heated pattern and hot carrier against the product sufficiently to soften the outer surface layers of the plastic bottle and make the pattern stick. The carrier is then retracted and the fields are deenergized by cutting off the currents to field source 100.

As shown in FIGS. 7 and 7A the core and carrier are suitably mounted so that they rotate together around base plate or bed 108a containing circular groove l08b which is continuous around the bed except for a portion equal to the width of slide 108c which contains an arcuate groove continuous with and completing circular groove 108b. Pins 108d are connected to yoke 108e supporting carrier 106 and ride in groove 108b. The yoke is non-magnetic. In the position indicated by III actuation of cylinder 88a moves piston 88b to cause slide 1080 to radially move pin 108d out of the groove and yoke 108e to force the carrier against the bottle. Spring means are provided to return the slide to its former position after fluid is released from the actuated cylinder or mechanical linkage is provided to connect with the slide and return it on reversing the action of the cylinder sothat the carrier isretracted.

be used in conjunction with the apparatus and methods previously discussed especially with regard to FIGS. 1-6, above. As shown in FIGS. 10 and 11, carrier 182 containing supporting members 183 comprises a flexible or elastomeric rubber or plastic bag or envelope (natural, SBR, nitrile or neoprene rubber, or plasticized PVC) or other appropriate flexible material attached to supporting members 183. The walls 184 of the carrier can be fabric reinforced rubber for strength,

and where the carrier is to be operated at elevated temperatures, the rubber may be a 'heat resistant silicone,

. acrylate or fluorocarbon (Kel F) rubber. Inlet and out- In step 'IV,- fi,e ld source l00and carrier ;106-have been rotated another 90, and a blast of air 109 from nozzle 110 is directed against carrier 106 to cool it if necessary and to blow awayexcess or left-over magnetic particles from the surface of the carrier which might-cause background problems. If desirable, at the end of the air treatment, a silicone-type release fluid may be sprayed onto the face of the carrier to facilitate release of the particle pattern from the carrier and release of the carrier from the product. In place of using the air to clean the carrier, a rotary brush or a belt or other means may be used to clean the carrier.

In some instances such as in the use of tapes for computers or cash registers, etc. or in publishing operations, a continuous translational motion of the product, such as paper, to be printed, is maintained. The printing procedure of the present invention is adapted to this typeof work by incorporating a belt-type or rotarytype carrier.

A belt-type system of this nature is shown schematically in FIG. 8.in which the magnetic pattern from magnetic particle cloud 111 is very rapidly established by type-face or field source 112, held in place as the carrier belt moves along by d-c magnet 113, and then heated by heat source 114 (induction or resistance such as resistance heating bars). Cooling device 115 such as water cooled roller cools the belt and provides a backup for one of the pressure rolls 116 as the sheet 117, such as a thermoplastic sheet or wax coated paper, is printed with the heated pattern. Air nozzle 118 blows away excess powder. The carrier belt 119 is supported and carried by rollers 120. The magnetic particle cloud is supplied from supply source 121. Re-arrangements of the apparatus shown can be made to permit printing both sides of the-sheet 117 at once, and other arrangements will be evident to persons skilled in the art.

In FIG. 9, a rotating drum carrier 139, rotating, counterclockwise, has the magnetic pattern from magnetic particles established by type-face (including type plate, othershaped metal devices, etc.) or field source 141 on the surface of the carrier. The patternis held in place by d-c magnet 142. The metal carrier is heated'by induction heating coil 143 so that hot transfer'can be made at the rolls 146. Airnozzles 155 cool thecarrier, if necessary, and blow. away excess powder. The image is printed on paper or plastic sheet or web 156 as the carrier passes between roller'146. Rollers l57'serve to also support and drive the drum-type carrier. The cloud 1580f magnetic particles such-as barium ferrite or iron oxide. is supplied to thesurface of carrier l39'opposite type face141from-supply source 159 which can be one of those previously described'herein. I

In FIGS. 10 0 14, which are schematic, there are shown further embodiments of the present invention. Themethod and apparatus shown in these Figuresm'ay let tubes or pipes, and 186, respectively, are positioned in the rear wall of the carrier to provide means for pumping in and pumping out gas or liquid (air, N2, water, etc.).

Tubes

185 and 186 are connected to suitable supply containers, pumps, and valves for controlling the proper pressure, heat, and amount of air, etc. supplied. It willbe appreciated that if expansion and contraction only is desired, only one conduit or tube may be needed since after expansion, the pressure on the carrier can be released to atmospheric and walls 184 will return to their normal position as shown in FIG. 10. With type bar or field source 187 energized and the pattern 188 of magnetic particles on the surface of the carrier, the carrier 182 is moved to the object or product 189, or vice versa, the carrier being expanded by water or air forced through tube 185 before it contacts the face of object 189. The expanded carrier thus forces the pattern against and prints on the irregular surface of the object which may be a perfume, detergent, beverage bottle or other container having an uneven or irregular surface. Just before or after printing, the field source 187is de-energized. After printing, the air pressure on the carrier is released, the carrier contracts, and the carrier 182 and object 189 are separated to begin the cycleof printing anew. Where the object 189 is thermoplastic or has a thermoplastic surface, or where a thermoplastic sheet lies on the surface of the carrier onto which the magnetic particles are deposited in a pattern, the carrier can be heated by means of hot air or water or other fluids or by a hot roller to cause the thermoplastic to soften and hold the magnetized particle pattern. Following heating and printing, the hot water can be replaced with cold water or other coolants to cool the carrier before the next cycle of printing. On the other hand where a thermoplastic sheet is not used on the carrier, or even where the magnetic particles are not mixed with thermoplastic parti' cles, etc., the carrier can remain in a heated condition. Thesurface of the carrier, also, as pointed. out herein, can be treated with'a silicone release agent or with Teflon to prevent sticking to the bottle. Since during expansion of carrier 182 against object 189, the printing surface 190 of the carrier may tend to change dimensionally, appropriate changes can be built into the indicia 191 on the surface of field source 187 tocompensate for any such change or possible distortion which might occur in operation. In fact, the method shown provides a way to expand the magnetic'particle'pattern so that it is larger than the indicia 191 on the pole of field source 187. i I r FIG- 12 represents a modification of the device s'howninFIGS. 10-11 where the rear surface-192 of the carrierisrigid or semirigid and'comprises a sheet of stainless steel, acrylonitrile-butadiene-styrene co polymer, etc. or other suitable nonmagnetic or nonmagnetizable material. In this case the expansion only occurs on the flexible side of the carrier and thus conserves space.

In FIGS. 13 and 14, a further modification or embodiment of the present invention is shown in which a carrier 182, which is somewhat wider than the object 189, is used in order to partially encompass the object and provide for adequate pressure along the area to be printed. In this device the printing or carrying member 193 of the carrier comprises a flexible preferably elastomeric, foam 193 such as natural or butadiene-styrene copolymer rubber, nitrile rubber, neoprene rubber,

I plasticized polyvinyl chloride, polyether and/or esterurethane etc. Other flexible preferably elastomeric rubbers and resins can be used. While the foam may be open or closedcell, the surface adjacent the object 189 should be closed cell or should have a skin or coating which is abrasion resistant and which carries the pattern of magnetized particles. The surface or skin coating on the foam should be a flexible and/or elastomeric material of the same type as the foam, but it may be a different material in which case adhesives or cements may be necessary to secure the skin to the foam. In the case of the polyurethanes a chlorosulfonated polyethylene coating may be sprayed onto the surface of the foam prior to use. Still other flexible and/or elastomeric foams and coatings for the same may be used. The working surface of element 193 may also be treated with release materials as discussed above. Also, foam element 193 contains a rigid or semirigid backing member 194 which supports the foam and helps in applying pressure against the surface of bottle 189 to be printed. It can be any of the rigid and semirigid materials discussed supra which are nonmagnetic or nonmagnetizable. It will be appreciated that the flexible magnetic particle pattern carrying means of carrier 182 of FIGS. -l4 should be sufficiently strong to withstand the use to which they are put but nevertheless should not be too thick in unexpanded or expanded form to excessively take up too much space in the air gap or in effect to move the pattern into other magnetic lines of force to alter the pattern in which case further modification of indicia 191 on field source 187 will be required.

To achieve printing from one side of an object such as a package in which the narrow neck prohibits access to the interior, use can be made of portions of the apparatus of FIGS. 1-7 above. For example, type-face or field source unit 94 in FIG. 6 is replaced by a magnetizing scanning array. A carrier member similar to carrier 96 of FIG. 6 would be used and a pattern would be created on it by scanningof the magnetizing array. The carrier then serves to transfer the pattern to the product upon which a permanent mark is made. The transfer can be aided in a variety of ways such as discussed above, including the use of a pre-applied adhesive on the product, a clear film with adhesive located on the carrier prior to making a pattern, a dry pattern (pattern of magnetic particles free of resin) with induction heating of the carrier by means of a coil, a hot-melt pattern (a pattern formed of the magnetized particles mixed with heat softenable resin, thermoplastic etc.) that would be softened by the heated carrier, or a resistance-heated carrier with dry or hot-melt patterns thereon. Although possible, it is not desirable usually to attempt to use hot cores in the magnetizing array or to use the cores to produce induction heating of the carcooling equipment. An arrangement of equipment in rier due to power consumption and the need for extra which a resistance-heated carrier is used is shown in FIG. 15. Original format 241 contains the pattern to be reproduced on plastic milk container 242, for example. The pattern is located on the rear of original sheet 241 so as to be in the optical field of photocell scanning array 244 and lens 245 which scan as shown by the arrows. The original 241 may consist of any simple material such as a piece of paper upon which, for example, a pattern of india ink has been prepared. The sheet need not be flat as shown but can have other shapes such as cylindrical if desired, so long as the lens and photocell scanning equipment are rearranged correspondingly to maintain good optical focus and permit scanning. It should be clear here as well as in apparatus previously described that the-photocells 244 or other photosensitive means employed may have to be shielded or protected from extraneous light so that they pick up only the desired light rays reflected or transmitted from the image on paper or other original being copied, and a reflecting and/or focusing mirror may be used instead of lenses.

The output signals from the photocell scanning array are amplified by amplifier equipment 246 and used to energize individual magnetizing coils 247 and tips 248 in the magnetizing array 249 which scans simultaneously and in synchronism with the photocell array. The magnetizing tips of array 249 are located close to or in contact with the rear surface of carrier 250 which is made of a thin sheet of stainless steel or other suitable nonmagnetic electrical conductor. Since the carrier 250 is nonmagnetic, the selective pattern in which the tips are magnetized and de-energized acts to attract magnetic particles from particle cloud 252 to form a pattern of particles on the front surface of carrier 250. The particles need not be provided in the form of a cloud but can be a shower, cascade, spray, etc. Upon completion of scanning by-magnetizing array 249, the complete magnetic particle pattern has been formed on carrier 250. After this time, at this time, or prior to this time if preferable, carrier 250 is heated by means of self-resistance upon energizing it via current-carrying supports 253 by means of power equipment represented bytransformer 255. The proper use of heat may help to hold the particle pattern in place on the carrier. The carrier is moved mechanically to cause it to press the pattern of magnetic particles against the surface of product 242, for example, a polyethylene milk container. Upon continuation, if necessary, of the heating action of carrier 250, the dry pattern of magnetic particles becomes embedded in the surface of product 242 as the heat of the carrier causes said surface to soften, become partly fused, and capable of flowing so as to achieve bonding with the particles. As discussed previously, a release agent such as Teflon or silicone coating can be used on carrier 250. Also, the carrier can be cooled at this point, if desirable, to assist solidification of the bonded pattern by means of air blasts etc. The carrier then returns to its original position, the face of the carrier cleaned if necessary, and the scanning step is repeated in preparation to printing on another product item.

In FIG. 16, the basic components of a multiplestation arrangement are shown. The multiple equipment units that create the patterns on product 242 are shown in a top view. The equipment operates to prooutputs corresponding to each photocell signal.IIt is hold the particles in place without collecting additional particles in subsequent steps, or a hot carrier may hold the particles of the hot-melt variety in place. Similarly,

segments

305 and 306 then form color patterns from

color mixtures

315 and 316 at stations XI and XII. The

combined color copy 317 is then applied to product 3l9,'such as a bottle, at the last station (number XIII). Baffle's 321 serve to maintain separation between the individual clouds of colored particles.

Other equipment arrangements are possible in which rotation or step-wise movement of the package as well asstep-wise movement of the printing mechanisms perseen that a single". recording can be used'if composite maybe scanning is employed as-intelevision A recording or" spected, and thus a map is prepared of the defects in inspection equipment, and related applications of this 7 sort will be evident to those skilled in the art.

It is known in the art of electronics that an electronic signal representing video information can be processed by appropriate circuitry to cause a greater or lesser contrast or resolution in the resultant portrayal. Hence, the circuitry of the amplifier described is not restricted to simple amplification but can incorporate contrast and resolution modification, for example, and other known operations. As another example, by suitable readjustment of the scanning speeds and amounts of travel, the equipment shown herein can be arranged to produce either a magnification or a reduction in the size of the pattern formed on the product with respect to the original. Also, an electronic synchronizing signal can be combined into the equipment to aid in governing synchronism in the scanning action of the photocell and magnetizing arrays.

In FIG. 17 a rotary arrangement is shown in which the three positions shown by numbers X, XI, and XII perm-it three different colors to be collected in sequence by carrier 290 which can include supports 29] which can be current carrying. Three

segments

304, 305 and 3060f the general type-face unit or field source having indicia, design, pattem and the like on their operating ends are outfitted with separate magnetizing coils 307, 308 and309 to 'permit individual magnetization and'are connected by bar 310 and .arms31l to rotary shaft 312. Supply hopper 313 or other source of magnetizable cloud or particles delivers cloud 314 adjacent the type face. Type-face segment 304 is energized to form the pattern of color from a mixture 314 of magnetizable particles and pigment particles (preferably pigmented magnetizable particles or a composition of a resin or plastic containing .pigment'and magneti'zable particles) atstation X and then deenergized. Natural adhesion forces'or a weak d-c current may then mit multicolor copy to be made. As shown in FIG. 18,

package or bottle 322 to'be printed is centrally located and is printed in three positions marked by numbers XX, XXI and XXII. In the position shown by numeral XX, the type-face o'r-field source 325 is energized and carrier 326 collects magnetizable particles from cloud 327 of Color A from supply hopper 313 preparatory to printing on the next package, not shown. The type-face and carrier units are arranged to pivot as a body around pivots 328. The darkened area 330 of package 322 was printedby carrier 326 two steps priorto that shown. The package has since been rotated through two clockwise steps.

Carrier 331 is'shown being cleaned by rotary brush 333 as an example, or other cleaning methods can be used. This carrier has just completed printing Color B (in the general area shown by circled B) onto package 322 in area 330and has since beenpivoted to the position shown with itsfield source 334. Package 332 has since been pivoted 90 to the position shown the Figure.

Carrier 336 is shown ready to'imprintpattern 337 of Color C onto darkened area 330 'of package 322 formed by field source 340. Following the application of Color C, in the general area defined by the circled C in the Figure, package 322 will be removed from the equipment and a new package placed into position for imprinting. At that time, carrier 326 will be ready to pivot into position for imprinting Color A onto the package. Carrier 326 will then pivot and be cleaned by its rotary brush 333 or other cleaning apparatus, etc.

The arrangement just described avoids the possibility of attraction of differently colored particles to a carrier since a given carrier is used for only one color. Natural adhesion forces or a d-c magnetic holding field can be used to hold collected patterns in place until imprinting occurs, as has been described earlier.

In place of rotary brush 333, the carrier may be cleaned by means of a belt, air stream, wiper or solvent or by means of vibrators or magnets. The type-face 328 etc. may also be cleaned by the various means disclosed if it is desired.

As shown in FIG. 19 taken in conjunction with FIG.

18 package or bottle 322 is positioned on turntable 350. Slide 351 actuated by piston 352 connected toof slide 355. After each printing step is completed, the appropriate slide is retracted and the turntable is rotated to a new position.

In FIGS. 17-19, as well as in other embodiments previously shown herein, for certain purposes, the carrier may be eliminated and the magnetic powder cloud caused to deposit directly on the indicia on the pole piece or core of

type face

304, 305 etc. By mildly jarring or vibrating the type face, the excess magnetic powder can be removed. The type face and consequently, the powder, then can'be heated by a superimposed high frequency induction current or by hot air etc. to a temperature sufficient to soften the outer layers of the plastic bottle I and momentarily pressed against the bottle and removed to leave a magnetic print on the bottle, such as a polyethylene bottle, corresponding to the indicia on the type face. Only sufficient pressure should be used to press the magnetic particles into the softened plastic to cause adherence without spreading out or smearing the print and also to avoid appreciable distortion of the surface of the bottle.

Multicolor imprinting from one side also can be accomplished by moving the package, for example, through successive stations which apply the different desired colors, or more than one carrier might be used. In moving the package, stationssuch as shown in FIGS. 1 to 6 supra, are located at different portions of a package conveying or handling system. The color components can then be applied in sequence. Over-printing or otherwise combining the successive colors can produce complementary colors from primary ones.

In other embodiments of this invention as shown herein, in which magnetized type-face units may be used, magnetic bodies nominally of corresponding facing areas could be used to concentrate and adjust the configuration of the magnetic fields.

The accumulation of excess magnetic particles (aggregation) on the carrier or object to be printed and/or dragging of particles from the desired area to be printed caused by movement of the paper or object or movement of the magnet still having some residual magnetic force can be reduced or eliminated by proper timing and current pulse control in energizing and deenergizing the magnetizing elements so as to remove magnetization prior to the possible collection of excess particles. Air jets or turbulent air currents directed near the pattern being formed can be used to dislodge the excess, more loosely held particles. Vibration can be used to dislodge excess particles such as can be achieved by sonic or mechanical vibration, or by ultrasonic waves. Vacuum action can also be used to remove excess magnetic particles. Build-up of particles in an electrostatic process does not occur to a great extent since the charged particles neutralize the electrostatic image as they collect on it. However, with magnetic particles a charge neutralization effect does not occur in this manner since each magnetizable particlein a magnetic field tends to become a magnet itself and to transmit flux to its neighbor. In this manner, printing of greater opacity may be realized by magnetic methods.

Magnetic, materials for use in making the magnet or cores and the magnetizable or magnetic particles can be any magnetic material known to the art. Examples of some metals and alloysare iron, cobalt and nickel and their alloys such as a 35 Co 65 Fe alloy; silicon steel; low carbon (0.1-0.2 percent) cast steel; high carbon (above 3 percent) cast iron containing 3% Si and varying amounts of P, Mn and S; Ni and Fe alloys with small amounts of Mo and Cr; 50 Ni 50 Fe alloys which can contain a small amount of copper; 54.7 Fe 45 Ni 0.3Mn; 17 Fe 81 Ni 2 Mo; sintered MnFe O ZnFe O tungsten steel containing 5W, 0.3 Mn and 0.7 C; chromium steel containing 3.5 Cr, 0.9C, and 0.3 Mn; alloys of iron and various amounts of Al, Ni, Co and Cuetc. such as 12 Al 20 Ni 5 Co, 10 Al I7 Ni -2.5'Co 6 Cu, 8 AI I5Ni 24 Co,- 3 Cu I Ti; alloysof iron, 52 Co and I0 14 V; an alloy of 50 Cu, 21 Ni and 29 Co; an alloy of 86.8 Ag, 8.8 Mn and 4.4 Al; an alloy of 77 Pt and 23 Co; 77.8 Pt and 22.2 Fe; and the ferrites such as barium ferrite, manganese zinc ferrite, manganese magnesium ferrite and so forth. Many of these materials have to be suitably treated such as by annealing, cold working, forging, etc., and sometimes in an electrical field, to produce their best magnetic properties. Of these materials it is preferred to use the iron, cobalt and nickel alloys and the ferrites. It, also, is preferred that the magnetic material used for the core have little or no retentivity and be highly permeable or have maximum permeability, so that sufficient magnetic intensity is directed onto the particles and so that the particles and core after deenergization of the coil will not cause smearing or shifting of the pattern due to the presence of residual magnetism. The cores can be solid or be laminated; they also can be made by powdered metallurgical methods. The magnetic or magnetizable particles can be made by methods well known in the art such as by spraying, micropulverizing, etc., can be acicular in shape, irregular,

. or can have other shapes and can have an average parple, polishing cloth can be made by impregnating cloths with a substantial amount of magnetic particles. Also,

a disinfectant, deodorant, fertilizer, pesticide, developing chemical can be mixed with the magnetic particles, preferably with a binder, such as a readily decomposable, hydrolyzable or water soluble, etc. compound such as gelatin, polyvinyl alcohol, polyethylene glycol and the like (for later release of the disinfectant etc. on use) and employed to impregnate cloth or paper to make a paper product which contains a disinfectant. Since the magnetic particles can be driven into and throughout the fibers of paper or cloth, increased loading and extended service life and potency are thereby provided and which represents a distinct improvement over conventional wet impregnating processes. The present process can be used to provide decorative patterns on paper napkins, bathroom tissue, cleaning tissue and so forth.

By using one or more of the various binders discussed herein including polyethylene, polyvinyl chloride, polyvinyl chloride-vinyl acetate copolymers, polyacrylates, phenol or resorcinol-aldehyde resins, polyesters, acrylonitrile-butadiene-styrene copolymers, vinylidene chloride polymers, polypropylene, polystyrene, cellulosic polymers, polyurethane and other thermoplastic or thermosetting materials and a pigment, colored magnetic particles can be made. Still other thermoadhesive polymers or resins can be used as binders such as rosin, gum, copal, Vinsol, Egyptian asphalt, hydrocarbon resins and the like. The binder can be disolved in solvent, mixed with the pigment and magnetic particle and spray dried. In another method the ingredients are mixed, preferably hot, cooled and micropulverized. Where the binder, magnetic particles and pigment exhibit the triboelectric effect, simple mixing may be sufficient to properly coat the magnetic particles with pigment and binder particles. Conventional compounding ingredients can be mixed with the resins or during preparation of the colored particles as desired such as antidegradants, stabilizers, curing agents if necessary, and r so forth. Only sufficient binder is used to combine the pigment and magnetic particles; greater amounts can be used if desired. Generally the binder can be used in an amount of from about to 75 parts per 100 parts by weight total of pigment and magnetic particles. The completed pigment-binder-magnetic particle can have an average particle size of from about 0.01 to 100 microns or larger. The color pigment is used in amounts sufficient to obtain the desired color and mask the color of the magnetic particles if dark or black. Large excess should not be used as such may interfere with cloud and magnetic pattern formation. The pigment particles can be of the same size as the magnetic particles but preferably are smallerin order to coat or substantially coat the magnetic particles. Various color pigments can be used including carbon black, ultramarine blue, chrome oxide, cadmium orange, molybdate orange, cadmium reds, Cd-Hg sulfide reds, CoSi violets, calcium carbonate, titanium dioxide, zinc sulfide, phthalocyanine blues, phthalocyanine greens, Amaplast orange LP, the Monastral Reds, the Benzidine and Amaplast yellows and so forth. Still other pigments can be used as shown in Materials and Compounding Ingredients for Rubber and Plastics, I965, Rubber World, New York, N.Y.

The process of the present invention can be used to imprint a serial number of a label which has been printed by a different method. Thus, this process can be used to provide various indicia and decorations on different printed media. In the case where the magnetic particles do not stick too well to the object to be printed such as certain coated papers, cold plastic, glass, ceramic, etc., the magnetic pattern can be sprayed with lacquer or enamel, or it can be laminated or coated by using a doctor blade, or by extruding a coating material on it, covering with transparent or translucent film, glassine or other suitable coating and so forth.

In addition to some of the other advantages mentioned herein, the magnetic printing process of the present invention provides means for dry printing without special paper or plastics of any sort, holding to the apparent public preference for, and several technical advantages of, dry processing with ordinary paper. In the area of reproduction, the methods of this invention and in particular those of FIGS. 30-38 and 41-42 would not be bothered by the limitation inherent in some electrostatic processes. Magnetic fields are not distorted by the presence of paper or plastics and such fields cannot be generated by friction effects. Mag-- netic fields are not affected by humidity, and the need for sensitive image plates and other fragile devices is eliminated.

There would appear to be no need for any voltageshigher than ordinary line voltages 1 10 or 220) in magnetic printing equipment, and all-trarrsistor electronics can be used. In contrast to the need for high voltages in electrostatic equipment, this feature can reduce certain space requirements, improve safety considerations, and, maintenance. By suitably controlling fringing and aggregation, as disclosed herein, the tendency for magnetic particles to transfer or even intensify the magnetic field could promote collection of thicker particle patterns than realized with electrostatics, thereby contributing to opacity. A number of auxiliary arrangerments using induction heating of the particles used for magnetic printing have been disclosed herein. In some cases, the magnetizing elements can also serve as induction heating devices. Although iron oxide and other heatable particles can be used for electrostatic printing, separate coils or other elements would be needed to produce induction heating of those particles. Furthermore, the process and apparatus of the present invention can be used in any system in which the information can be converted to timesequential'individual signals (i.e., digital) and can be suitable for remote orfacsimile-type use, i.e., I telegraph or by broadcasting (facsimile). In other words, amplifier 246 of FIG. 15 can be part of a telegraph system or broadcast system to transmit the information to a distant station where the incoming signals are then used eventually after suitable amplification to operate a magnetic core or magnetic scanning array to cause printing, etc. The pro cesses and methods disclosed herein have applications in the fields of printing, publications, communication systems, computation and business machines, copying, impregnating, coating, packaging, textiles, special papers and so forth.

It will be understood that various changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

What is claimed is:

l. A method of printing a selected configuration having defining edges upon an object with finely divided toner particles, comprising the steps of registering a source of a magnetic force field with one side of a pattern receiving carrier sheet formed of a material that is non-polar in the presence of the force field, providing polar toner particles on the second side of said sheet in a random supply, said toner particles being magnetizable by the magnetic force field,

activating the magnetic force field source and thereby establishing a magnetic force field corresponding to said selected configuration, said force field passing through said sheet and acting upon said polar toner particles to simultaneously deposit and compact said toner particles upon said second side of the sheet in a pattern corresponding to said selected configuration,

said force field when activated releasably attaching said toner particles to said second side so that when said force field is deactivated said particles adhere to the second side with a force exceeding the force of gravity exerted upon the toner particles for subsequent transfer to the object,

deactivating said force field, and

placing the carrier against an object with the pattern of toner particles adjacent the surface of the object and transferring of said toner particles from said carrier to said object.

2. The method of claim 1 including the step of selective removal of toner particles from said second side including the edges to increase the sharpness of the residual pattern. 1

3. A method as defined in claim 1 wherein said toner particles are iron alloys.

4. A method as defined in claim 1 wherein said toner particles are cobalt alloys.

5. A method as defined in claim 1 wherein said toner particles are nickel alloys.

' 6. A method as defined in claim 1 wherein said toner particles are manganese zinc ferrite.

7. A method as defined in claim 1 wherein said toner particles are manganese magnesium ferrite.

8. A'method as defined in claim 2 and wherein the step of removing some of the toner particles is performed by jarring the sheet.

9. A method as defined in claim 1 and including the step of producing pressure contact between said second side of said sheet and an article for transferring the residual pattern from said sheet to said article.

10. The method as defined in claim 1 and including the step of transferring the residual pattern to the object which has a surface having a greater adherency character for the toner particle than the adherence between the residual pattern and the sheet created by said force field, the last-named step including producing pressure contact between said second face of said sheet and said surface of the article.

11. A method asdefined in claim 9 wherein the step of transferring the residual pattern to an object includes heating said sheet.

12. A method as defined in claim 1 wherein said sheet is a resiliently bandable carrier sheet and said method includes the step of transferring the residual pattern to a curved surface of an object by bending the carrier sheet about said curved surface.

13. A method as defined in claim 1 wherein said sheet is a resiliently bendable metallic carrier sheet and said method includes the step of transferring the residual pattern to a curved surface of an article by bending I the carrier sheet about said curved surface to produce pressure contact between said second face and said curved surface.

14. A method as defined in claim 1 wherein said particles are of ground barium ferrite.

Claims

1. A method of printing a selected configuration having defining edges upon an object with finely divided toner particles, comprising the steps of registering a source of a magnetic force field with one side of a pattern receiving carrier sheet formed of a material that is non-polar in the presence of the force field, providing polar toner particles on the second side of said sheet in a random supply, said toner particles being magnetizable by the magnetic force field, activating the magnetic force field source and thereby establishing a magnetic force field corresponding to said selected configuration, said force field passing through said sheet and acting upon said polar toner particles to simultaneously deposit and compact said toner particles upon said second side of the sheet in a pattern corresponding to said selected configuration, said force field when activated releasably attaching said toner particles to said second side so that when said force field is deactivated said particles adhere to the second side with a force exceeding the force of gravity exerted upon the toner particles for subsequent transfer to the object, deactivating said force field, and placing the carrier against an object with the pattern of toner particles adjacent the surface of the object and transferring of said toner particles from said carrier to said object.

2. The method of claim 1 including the step of selective removal of toner particles from said second side including the edges to increase the sharpness of the residual pattern.

3. A method as defined in claim 1 wherein said toner particles are iron alloys.

6. A method as defined in claim 1 wherein said toner particles are manganese zinc ferrite.

8. A method as defined in claim 2 and wherein the step of removing some of the toner particles is performed by jarring the sheet.

11. A method as defined in claim 9 wherein the step of transferring the residual pattern to an object includes heating said sheet.

13. A method as defined in claim 1 wherein said sheet is a resiliently bendable metallic carrier sheet and said method includes the step of transferring the residual pattern to a curved surface of an article by bending the carrier sheet about said curved surface to produce pressure contact between said second face and said curved surface.