DIFFUSION TRANSFER SHEET REGISTRATION

Abstract: A generally planar T-shaped separator (45) replaces the conventional separator in a diffusion transfer processor (10). The bar (46) of the T-shape projects forwardly in spaced parallel relation with respect to the forward side of a diffusion transfer processor with the stem (48) of the T-shape centrally projecting into the chemical bath of the processor. This permits register pin receiving end portions of a light sensitive negative sheet (60) and receiver sheet (62), disposed in superposed relation and respectively under and overlying the T-bar of the separator, to be registered together with pins (66) at their respective corner portions facing the processor. The two sheets, joined by the pins to maintain registration, are then moved through the processor while the stem of the separator maintains a spacing between the two sheets while in the chemical bath to allow the chemical bath to flow between the sheets for proper development.

Description: DIFFUSION TRANSFER SHEET REGISTRATION Technical Field The present invention relates to diffusion transfer processors and more particularly to a sheet separator per- mitting accurate registration of a light sensitive sheet of film or paper having an image exposed upon it (hereinafter called "negative sheet") and a non-sensitive image receiving sheet of film or paper (hereinafter called "receiver sheet") prior to, during, and after- being processed. ' A diffusion transfer processor transfers a graphic image from an exposed negative sheet to a receiver sheet by passing the superposed negative sheet and receiver sheet through a bath of chemical activator or developer in which the negative sheet and receiver sheet are temporarily sepa- rated one from the other as they move through a tray contain- ing the chemical bath and are rejoined in face to face con- tiguous contact by a pair of squeegee rollers retaining ex- cess activator within the tray. Conventional diffusion transfer processing units do not provide for pin registration of the negative sheet with the receiving sheet while the negative sheet and receiving sheet are being processed for the reason the negative sheet and re- ceiving sheet must be disposed on the respective upper and lower surfaces of a planar separator when entering the chemical bath to insure contiguous coating of the chemical activator on the emulsion fase..surface of the negative sheet and receiver sheet. It is desirable when preparing graphic images, to be later reproduced for printing, to register a plurality of supplemental images on a plurality of receiving ,A -_2^PΓ sheets from which printing plates can be exposed in regist for color printing in different colors, or the like. This invention provides a negative sheet and receiver sheet sep rator permitting such registration. Background Art Diffusion transfer processor units presently used co prise a table top unit including a tray containing a bath chemical activator into which one edge of a negative sheet. and receiver sheet are manually inserted on respective upp and lower surfaces of a planar separator. At least one pa of negative sheet and receiver sheet advancing rollers, driven by an electric motor, advances the negative sheet a receiver sheet through the activator bath. The planar sep rator, being at least coextensive with the negative and re ceiver sheet widths, prevents pin registration of the nega tive sheet with the receiver sheet while being processed b the apparatus. At least one conventional diffusion transf processor provides a negative sheet and receiver sheet hor zontal ' shelf adjacent the entrance opening, is supported b the shelf to permit alignment of one edge surface of the r spective negative sheet and receiver sheet but does not pe mit repeated accurate registration of the negative sheets and receiver sheets while passing through the processor. Disclosure Of The Invention The present invention permits accurate registration a negative sheet with a receiver sheet when processed by a diffusion transfer processing apparatus. This is accσmpli ed by providing a negative sheet and receiver sheet separa which replaces the generally rectangular planar separator conventional diffusion transfer processing apparatus. In preferred embodiment, the improved separator is generally planar T-shaped with the bar of the T-shape overlying a sh or platform adjacent the sheet entrance opening of the processor and parallel with the longitudinal axis of its rollers with the stem of the T-shape projecting into a che ical activator containing tray of the machine. This permit the negative sheet and receiver sheet to be manually dispos OM at one end portion in superposed relation over and below the bar portion of the separator. The respective corner portions of the negative sheet and receiver sheet, facing the appara- tus, after having been previously punched with registration pin holes, are joined together by low profile registration pins capable of passing through the processor rollers. The negative sheet and receiver sheet are then advanced into and through the processing apparatus in a conventional manner with the registration pins being removed after the predetermined development time. Other negative sheets and receiver sheets, having been similarly punched with registration pin holes, may be processed in a like manner for subsequent accurate reg- 'istration of one image bearing receiver sheet with respect to another. Images from two or more register pin punched negative sheets may be transferred onto a single register pin punched receiver sheet in accurate register for the purpose of build- ing composite graphic images on a single receiver sheet or for proofing prepared separations in color or black and white. Brief Description Of The Drawings Figure 1 is a perspective view of a conventional diffu- sion transfer processor with the cover removed and one front drive roller in lifted position exposing the negative sheet and receiver sheet separator; Figure 2 is a perspective view, to a larger scale, of the separator when removed from the processor of Fig. 1; Figure 3 is a perspective view of one embodiment of the improved separator, per se; Figure 4 is a perspective view of the separator of Fig. 3 illustrating the relative position of a negative sheet and receiver sheet when positioned on the separator and pin reg- gLstered-with each other? _. Figure 5 is a perspective view, to a larger scale, of one of the registration pins, per se; Figure 6 is a fragmentary perspective view, similar to Fig. 4, to a different scale, illustrating the relative posi- tion of the improved separator and registered negative and receiver sheets with respect to the diffusion transfer proc sor of Fig„ 1, the latter being shown by dotted lines; Figure 7 is a perspective view of the improved separa of Fig B 3 and a support therefore when used with another mo transfer processor, illustrated by dotted lines, lacking a sheet support shelf and front drive rollers; and, Figure 8 is a perspective view of another embodiment the improved separator illustrating the relative position o negative sheet and receiving sheet when positioned on the s rator and pin registered with each other. The Best Mode For Carrying Out The Invention I the ' rawings: Referring more particularly to Figs. 1 and 2, the ref ence numeral 10 indicates a conventional diffusion transfer processor apparatus model No. P1400, presently marketed by nuArc Company, Inc., 4100 West Grand Avenue, Chicago, 111. 60651 USA. The apparatus 10 comprises a horizontal table b 12 supporting a pair of upright walls 14 and 16 in turn sup porting a pair of drive rollers 18 at its forward side, hav longitudinally spaced diametrically enlarged " portions 19 in mediate their ends and a pair of squeegee rollers 20 adjace their rearward upper limit with each pair of rollers driven a motor surrounded by a housing 22. The end walls 14 and 1 support a guide 24 overlying a tray, not shown, containing bath of chemical activator or developer, not shown, with a separator 26 interposed between the tray and guide in sandw form. The forward or front side of the machine supports a horizontal platform or shelf 28 for supporting paper or she as hereinafter explained. The separator 26 is generally planar and substantiall coextensive with the spacing between the walls 14 and 16 wi its forward edge surface 30 projecting horizontally forward of the-apparatus in a plane between the drive rollers 18 wi its rearward edge portion 32 transversely turned downwardly from the plane of its forward edge for entering the fluid b in the spacing between the guide 24 and underlying tray. A jacent its forward edge, the separator 26 is provided with plurality, three in the example shown, of longitu inally aligned apertures 34 loosely surrounding the drive roller diametrically enlarged portions 19 gripping superposed sheets being moved through the apparatus. The apparatus 10 further includes an on/off switch 36 for starting the motor, a timer contained by a housing 38 and activated by a lever 40 and a time interval lamp 42. The above description forms no part of the invention other than to set forth the combination employed in which the conventional separator 26 is removed and not used. The reference numeral 45 (Fig. 3) illustrates one em- bodiment of the improved separator, per se, comprising a section of thin sheet-like material having a generally T-shap- ed configuration characterized by a bar portion 46 and a tongue or stem portion 48. The length of the bar portion 46 is substantially coextensive with the length of the drive • rollers 1& and overlies the shelf 28 with its longitudinal axis parallel with the longitudinal axis of the drive rollers 18. The width of the bar portion 46 is a matter of choice but is preferably relatively narrow when compared with its length. The transverse width of the tongue or stem portion 48 is relatively narrow when compared with the length of the bar portion 46 being slightly greater than the length of the centermost diametrically enlarged portion 19 of the drive rollers and is characterized by parallel side edges 50 and a transverse vertical aperture 52 therebetween which nests the centermost enlarged portion 19 of the drive rollers. The free end portion of the stem 48 is turned downwardly, as at 49, for entering the fluid bath below the tray guide 24. The stem side edges 50 diverge from the position of the aperture 52 toward the adjacent side edge of the bar portion, as at 53 and 54, with the spacing between these diverging edges 53 and 54, -at their juncture with the bar portion 46, being substan- tially less than the length of the bar portion and less than the transverse width of negatives or receiving sheets to be registered prior to processing, as presently explained. The spacing between the separator aperture 52 and for- ward edge 56 of the bar portion is a matter of choice and 51 OMPI preferably a distance at least greater than the transverse width of the stem ' 48 to allow ample space between the bar and forward side of the apparatus 10 for registering a neg tive sheet and receiver sheet, as presently explained. The respective end portions of the T-bar 46 overlie are secured to a pair of spacers 58 having a thickness at least greater than the thickness of a negative or receiver sheet for the purposes of maintaining the separator in a plane spaced above the level of the upper surface of a sup porting surface, such as the shelf 28. Referring more particularly to Figs. 4, 5 and 6, the separator 45 is disposed on the shelf 28, in the position illustrated by Fig. 6, wherein the respective end portions the T-bar 46 are adjacent respective side edges of the she and the separator aperture 52 nesting the central enlarged portion 19 of the driving rollers 18 with the down turned e portion 49 of the tongue disposed within the fluid bath of the tray below the guide 24. The separator 4 * 5 is secured t the shelf in this position, such as by the use of tape or screws, not shown, joining the respective end portions of t T-bar 46 to adjacent side surfaces of the shelf 28. A nega tive sheet 60, exposed to contain a negative image to be re produced, not shown, is placed emulsion side up, on the upp surface of the shelf 28 with one of its end portions underl ing and projecting beyond the T-bar 46 toward the front sid of the processor 10. An identical size receiver sheet 62, with its emulsion side down, is placed over the negative sh 60 and the T-bar 46 with one of its end edges coinciding wi the end of the negative sheet adjacent the apparatus. Prio to superposing the negative sheet 60 and receiver sheet 62, both sheets are provided, at the end portion facing the app ratus, with the register pin receiving holes 64. With the register pin holes 64 in substantial alignment, a low profi register pin 66 is placed within the aligned register pin holes 64. The register pin 66 ( Fig . 5) is conventiona l and is characterized by an annular flange 63 having a coaxia l upstanding relatively short cylindrical portion 70 diametri- cally closely received by the register pin holes in a fric- tion fit which secures the negative sheet 60 to the receiver sheet 62 at opposing corner portions of the two sheets ad- jacent the apparatus 10 and in the spacing between the T-bar 46 and front surface of the machine outwardly of the separa- tor diverging edges 53 and 54. Obviously, other conventional types of register pins, not shown, may be used, if desired. The register pin joined negative sheet 60 and receiver sheet 62 are then manually moved as a unit in a sliding action along the shelf 28 and separator 45 toward the drive rollers 18 until gripped thereby and advanced into the chemical bath. As the driving rollers 18 advance the sheets 60 and 62, the separator tongue 48 maintains a spacing or air gap between the two sheets, with the exception of the respective joined corner portions, as the sheets are advanced into and passed through the chemical bath thus insuring contiguous contact with the activator on all surfaces of the two sheets. The registered leading edges of the negative 60 and receiver 62 are guided by the tray guide 24 to the squeegee rollers 20 which, by gripping opposing surfaces of the superposed sheets, remove excess activator from the surfaces thereof and insures contiguous face to face contact of the emulsion surfaces. After the two sheets have passed through the squeegee rollers 20 the timer is activated by manual movement of the timer lever 40 for a predetermined development time, such as 30 seconds, indicated by the timer light 42, as is conven- tional. Thereafter, the two sheets are manually separated one from the other and the register pins 66 removed. Ad i- tional negative and receiver sheets, similarly punched for re- ceiving the register pins 66, may be processed in a like manner for forming registered artwork separations, or the like, -for multicolor printing. Referring now to Fig. 7, some diffusion transfer machines, such as illustrated by dotted lines 72, are not provided with a negative sheet and receiver sheet placement shelf and in this event a rack 74 is provided for supporting the separator 45o The rack 74 is substantially inverted U-shaped in general configuration comprising a horizontally disposed bight portion 76 abutting the machine 72 adjacent and spaced below its sheet entrance opening 78 and is suppo ed by parallel legs 80. Wings or tabs 82, only one being shown, on the respective leg 80, connect the rack to the ho ing of the machine. After removing the conventional separa tor, not shown, from the machine 72 the separator 45 is dis posed on the top surface of the rack 74 and secured thereto with its tongue portion 48 extending into the machine 72 in the manner described hereinabove for'the apparatus 10. Thereafter, the negative sheet 60 and receiver sheet may be processed by the machine in the manner described her inabove. Similarly, some diffusion processor machines are equipped with the front driving rollers and in this event t registration pin joined negative sheet and receiver sheet a manually inserted through the machine opening 78 and moved through the bath until gripped by the -squeegee rollers 84. Referring to Fig. 8, the numeral 145 indicates anoth embodiment of the improved separator in which the stem port of the separator is transversely widened and bifurcated by U-shaped slot 92 to form a pair of separator stem portions and 96. The width of the U-shaped slot 92 is at least equa to the length of the centermost diametrically enlarged port 19 of the drive rollers 18 with the bight portion 98 of the U-shaped slot terminating in spaced relation,with respect t the forward side edge 156 of the separator bar portion 146, a distance equal to the transverse dimension of the bar por tibn. The transverse width of the respective dual stems 94 and 96 is slightly less than the spacing between any two ad jacent drive roller enlarged portions 19 for the reasons pr sently explained. This permits the negative sheet 160 and ceiver. sheet 162 to be similarly punched with a plurality o registration pin holes 164, three in the example shown, and similarly disposed in respective over and underlying relati with respect to the separator bar portion 146 and adjacent end portions of the dual stems 94 and 96 for joining the leading edge portion of the two sheets by register pins 166. In use, the separator 145 is similarly disposed on the shelf 28, or rack 74, as disclosed hereinabove, with its dual stems 94 and 96 projecting into the processor 10 between the drive rollers 18 within the spacing defined by adjacent end portions of the drive roller diametrically enlarged portions 19.

Claims: 1 Cla ims 1 1. In combination with a diffusion transfer processo 2 having an elongated entrance opening for admitting a pair o 3 superposed sheets to be processed, a tray containing a chem 4 cal bath, a guide overlying the tray for guiding the sheets 5 into and out of the chemical bath and having at least one p 6 of elongated rollers for progressively advancing the sheets 7 through the processor, the improvement comprising: a genera 8 T-shaped sheet separator having at least one stem portion p 9 jecting, at one end, into the processor intermediate the le 10 of the entrance opening and interposed at its innermost end 11. portion in the chemical bath between the tray and guide, sa 12 separator having a bar portion at least coextensive with th 13 length of the entrance opening and disposed in spaced relat 14 outwardly of the entrance opening a distance permitting the 15 edge of the sheets adjacent the processor and respectively 16 over and underlying the bar portion to be joined together b 17 register pin means on opposing sides of the stem portion 18 before entering the entrance opening. 1 2. The combination according to claim 1 in which sai 2 processor is provided with a planar sheet support lying in 3 plane parallel with the longitudinal axis of the entrance 4 opening and in which said separator bar portion extends tra 5 versely of the support in parallel spaced relation. 1 3o The combination according to claim 1 or 2 in whic 2 said pair of rollers includes a pair of drive rollers dispo 3 ed adjacent the entrance opening, each roller of said pair 4 drive rollers having a cooperating diametrically enlarged 5 portion medially its ends, said separator stem portion bein *->•.,'_•>-.• ' further characterized by an aperture intermediate its width and length cooperatively receiving said drive roller diamet- rically enlarged portions. 4. The combination according to claim 3 and further including: a spacer interposed between each end portion of the separator bar portion and the adjacent surface of the support. 5. The combination according to claim 1 or 2 in which said pair of rollers includes a pair of drive rollers disposed adjacent the entrance opening, each roller of said pair of rollers having cooperating longitudinally spaced diametrically enlarged portions intermediate their ends, said separator stem portion being longitudinally divided to form at least two stem portions and define a slot therebetween, the trans- verse width of the slot being at least equal with the longi- tudinal dimension of the drive roller diametrically enlarged portions and the transverse width of the respective ste por- tions being less than the spacing between the drive roller diametrically enlarged portions. 6. The combination according to claim 5 and further including: a spacer interposed between each end portion of the separator bar portion and the adjacent surface of the support.

Inventors: BYERS T
Applicants: BYERS T
Application year: 1980
Main classification: G03D9
IPC codes: G03D9