US3472590A - Photocopy apparatus - Google Patents

Description

Oct. 14., N FMRBANKS ET AL 3,472,590

PHOTOCOPY APPARATUS Filed Oct. 17, 1966 5 Sheets-Sheet L col IN VENTORS HENRY N.FA!RBANKS DANJEL H ROBBINS ATTORNEY H.IN. FAIRBANKS ET AL 3,472,590

Oct. 14, 1969 PHOTOCOPY APPARATUS 5 Sheets-Sheet Filed Oct. 17. 1966 0.0.5 @952 u mo 0 ll mOFO 2 m2 mo mwJ om INVENTORS HENRY N. FAlRBANKS DANIEL H. ROBBINS ATTORNEY Oct. 14, 1969 Filed Oct. 1'7, 1966 H. N. FAIRBANKS ET AL PHOTOCOPY APPARATUS 5 Sheets-Sheet 3 FIGS INVENTORS. HENRY N. FAIRBANKS BY DANIEL H.ROBB!NS ATTORNEY Oct. 14, 1969 H FMRBANKS ET AL 3,472,590

PHOTOCOPY APPARATUS Filed Oct. 17, 1966 5 Sheets-Sheet INVENTORS. HENRY N. FAIRBANKS DANIEL H. ROBBINS ATTORNEY Oct. 14, 1969 F N ET AL 3,472,590

mvsmoxs. HENRY N. FAIRBANKS BY DANIEL H.ROBBINS ATTORNEY United States Patent 0 U.S. Cl. 35528 8 Claims ABSTRACT OF THE DISCLOSURE A photocopy apparatus having a sheet feeding mech anism, a leading edge detector, and a pivoting copy holder. The sheet feeding mechanism consists of a flattened roller used to deliver an exposed sheet to a developer. The flattened portion of the roller obviates the necessity of matching drive speeds between rollers in the developer and the sheet feeding roller. The edge detector consists of a pair of movable photocells. The photocells are coupled to a logic bridge circuit so that, when the leading edge of the copy paper covers the first photocell, the delivery roller is stopped. The edge detector is movable to allow adjustment in the amount of copy paper to be fed to the exposure station.

The present invention relates to new and improved photocopy apparatus.

Photolithographic ofl'set reproduction systems are known in the prior art wherein a photo-sensitive plate is positioned over an imaging platen. Graphic indicia to be copied is positioned upon an illuminated copy board and the photo-sensitive plate is exposed by opening a shutter or turning on illumination devices for predetermined time periods. The plate is thereafter developed and inked to form a master which in turn allows copies to be produced in an oifset developing machine.

It is the principal object of the present invention to provide a new and improved photocopying machine.

It is a further object of the present invention to provide a new and improved photocopy machine that accurately feeds various predetermined lengths of photosensitive media upon an imaging platen to accommodate varying sizes of images to be reproduced without waste of the photo-sensitive media.

It is a further object of the present inventionto provide special roller drive means for selectively feeding various lengths of exposed photo-sensitive media into a developing processor, which special roller means operates on a fixed number of revolution basis, and need not 0 operate at the same drive speed relative to the drive speed of the rollers associated with the developing processor and furthermore which need not be raised relative to the platen when the unexposed media is first fed to the imaging platen and lowered after the media has been positioned upon the platen.

It is a further object of the present invention to provide photocopy apparatus having cutting means which automatically cuts the exposed media just as it is being driven off of the platen onto the developing processor to obtain a clean cut and to prevent undesirable shifting of kicking of the media owing to the cutting action.

It is a further object of the present invention to provide a photocopy machine having a pivotable copy board which protects the relatively fragile illumination devices associated therewith when the copy board is exposed in its load position, requires little strength to manipulate and does not extend appreciably from the machine when in its opened position.

It is yet a further object of the present invention to provide highly sensitive devices for detecting the presence of the leading edge of the photo-sensitive media in order 3,472,590 Patented Oct. 14, 1969 to halt the feeding of the media after a predetermined length has been fed to the imaging platen.

It is yet a further object of the present invention to provide a liquid processing bath for developing the exposed media where the quantity of developer liquid supplied to the processor is extremely low relative to the surface area of the developed media thereby to preserve developer and reduce developer waste.

Other objects and advantages will become apparent as the following description taken in conjunction with the drawings proceeds.

FIGURE 1 discloses a side view of the photolithographic platemaking machine.

FIGURE 2 illustrates various features associated with the platemaking machine.

FIGURE 3 illustrates a second embodiment of the leading edge detector illustrated in FIGURE 2.

FIGURE 4 illustrates a film processing bath.

FIGURE 5 illustrates a front view of the platemaking machine.

FIGURE 6 illustrates a top view of the platemaking machine.

FIGURE 7 illustrates various features of the pivotable copy board.

FIGURE 8 illustrates a novel roller configuration.

Referring now to FIGURE 1, cabinet 1 is disclosed having a glass imaging platen 2, a mirror 3, lens system 4, and a pivotable door 6 having a copy board portion 7 thereon. Illumination means 10 are positioned below copy board 7 so as to illuminate the indicia thereon. Lens system 4 focuses images of the illuminated indicia on the imaging plane of glass imaging platen 2. A shutter device 8 is positioned along optical path 9 for controlling the exposure of the photosensitive media 11 positioned upon the upper surface of glass platen 2. Door 6 is pivoted about pivot point 12 so that the indicia upon the copy board is changed or loaded therein by pivoting door 6 until the door assumes the horizontally oriented position illustrated at 13. Glass cover plate 14 is spring biased over foam rubber pad 16 to maintain the indicia accurately Within the imaging plane. By squeezing latch members 17 and 18 toward one another, glass cover 14 is released and swung upwardly to facilitate manipulation of the indicia upon foam rubber plate 16. Pivoted door 6 is counterbalanced, since it is not pivoted at its bottom, to facilitate the manipulation of the door. This arrangement is such that the lower door portion 19 extends inwardly with respect to the machine so that less of the door protrudes into the working area so as to conserve space and reduce the risk of bumping into the door. It is also to be noted that the lower portion of door 19 in the open position covers the fragile illumination lights to eliminate the risk of breakage when the door is opened. After'the PY board is loaded, latch members 17 and 18 are squeezed together so as to again spring bias glass cover plate 14 against the foam rubber pad 16. This may be accomplished in one motion while pivoting the door into its closed position. The particular arrangement of the copy board with respect to the aforementioned optical elements result in a compact photocopy machine having a short optical path.

As shown in FIGURE 2, a metallic plate 21 is positioned above imaging platen 2 so as to roughly define the imaging plane. Cassette 22 having a roll of photo-sensitive media therein is positioned adjacent cutting means 23 which is in turn positioned adjacent platen 2. Drive roller 24 pulls the photo-sensitive media out of the cassette and into the imaging platen upon being rotated by drive motor 26. A sequence timer 27 is schematically disclosed for controlling the timing of the various operational elements of the system. Timer 27 could consist of a plurality of commonly rotatable cams which coact with associated switches for sequentially marking various leads emerging from the timer. When timer 27 is in its home or reset state, conductor 28 is marked or energized. The cycle is commenced by energizing conductor 29, by actuating pushbutton 31, which in turn causes drive motor 26 to drive the media from cassette 22 into the imaging plane. The leading edge of the driven media passes under the flat portion of roller 32 and is thereafter detected by leading edge detector 33. As shown in FIGURE 2, detector 33 is positioned adjacent slot 34 formed within platen '21 and includes arm 36 pivoted about pivot point 37. The angular position of arm 36 is adjusted by knob 38 depending upon the desired length of media which is to be exposed. Photosensitive transducers B and A are mounted upon the pivotable arm and are connected to a comparator or logic bridge 42 as shown. Illumination means 40, shown positioned below platen 2, illuminates the aforesaid transducer or photo cells. The leading edge of the photosensitive media as it arrives at detector 33 will sharply attenuate the light detected by photocell A relative to the light detected by photocell B. The resulting unbalanced voltage applied to logic bridge 42 causes a stop signal to be forwarded to drive motor 26 over conductor 44 so that feeding of film is halted upon the detection of the leading edge by detector 33. An alternate detector which is highly sensitive and yet rugged and reliable is illustrated in FIGURE 3 and comprises a cylinder 46 which is pivoted about pivot point 47 and which is mechanically coupled to microswitch 48. A feeler element 49 which could take the form of a thin screw, rests upon the surface of imaging platen 2 as shown. Since the mass of feeler 49 is small relative to the mass of cylinder 46, it is apparent that the leading edge of the media will readily cause cylinder 46 to be rotated to in turn cause microswitch 48 to be closed thereby to stop drive motor 26. When the exposed media is thereafter driven off of imaging platen 2, gravity will cause member 46 to rotate back to its initial angular position. With photo-sensitive media which has considerable thickness such as photolithographic plate material, the angular rotation will be sufficient to close microswitch 48.

Timer 27 now actuates shutter relay 52 to expose the photo-sensitive media and thereafter cause conductor 53 to be marked to energize windout motor 54 and roller 32 coupled thereto. Knife motor 56 is also energized at this time and the exposed media is cut by virtue of knife 23. Circular portion 57 of roller 32 contacts the media and commences to pull it out of the imaging plane during cutting so as to prevent undesirable shifting or kicking of the media which would otherwise occur due to the impact of knife 23 upon the media. Drive motor 58 which drives developer rollers'59 and 61 may be continuously rotating or may be energized for an appropriate interval by lead 59 of timer 27. In any event, rollers 59 and 60 will be rotating when the leading edge of the media arrives in developer processor 62. The control circuitry of windout motor 54 will cause this motor to make a fixed number of revolutions which will be sufficient to drive the shortest length of fed media into the bite of rollers 59. In the prefered embodiment, flattened roller 32 drives the media at 4 or inches a second whereas the developer rollers drive the media at /2 inch a second. This disparity between driving speeds is made possible by the flattened portion of roller 32. Since the drive speed of roller 32 may be greater than the drive speed of roller 59, an increase in the loop length of the media at the throat of processor 62 will result. However, near the end of each Whole revolution of roller 32 its flattened portion will allow the media to snap backward under the roller to thereby reduce the loop length and accordingly no matching of the drive speeds of these rollers is required. Additionally, by virtue of this snap-back action roller 32 need only be rotated a fixed number of revolutions regardless of the length of media fed out of the cassette so as to greatly simplify the drive circuit controlling motor 54. For a oneinch diameter roller 32, the flattened portion is cut to shave A3" off of the diameter as shown. Lead 64 is thereafter energized to reset sequence timer 27 and thereby set the stage for the next cycle. It should be observed that since cassette 22, knife 23, and platen 2 are positioned adjacent one another, there is little exposed media which is wasted should cassette 22 be removed at the end of a particular cycle. In other words, in contrast with prior art machines, fresh unexposed media is not delivered to the platen as exposed media is removed therefrom and processed, but is removed from the cassette only upon the initiation of a new cycle.

Processor 62 comprises a bulky bulbous guide member 63 which is bulky enough so that its submerged volume is at least as great as the volume of developer fluid contained Within processor 62. The entire surface of guide means 63 which is preferably smoothly continuous but may have indentations therein, is impervious to processing fluid so that it displaces an amount of fluid so that it displaces an amount of fluid equal to its submerged overall volume. Guide means 64 cause the media to closely follow the outline of guide member 63 so that the volume of developer fluid present is extremely small relative to the surface area of the media processed in processor 62. As a result, much smaller quantities of contaminated fluid are drained from the processor than would otherwise be the case.

The above described embodiments being exemplary only, it will be understood that additions thereto, omissions therefrom and modifications thereof can be made without departing from the spirit of the invention, and that the invention hereof comprehends embodiments differing in form and/ or detail from those which have been specifically disclosed. Accordingly, the invention is not to be considered as limited save as is consonant with the recitals of the following claims.

What is claimed is:

1. Photocopy apparatus comprising:

(a) a copy board for supporting items to be reproduced;

(b) means for illuminating said copy board;

(c) an imaging platen having an imaging plane associated therewith;

(d) means for focusing images of said items upon said imaging platen;

(e) first feed means for selectively feeding predetermined lengths of photo-sensitive media upon said imaging platen;

(f) detector means positioned along said platen for detecting the presence of the leading edge of said photosensitive media and for halting the operation of said first feed means upon the detection of the leading edge of said photo-sensitive media;

(g) means for exposing said photo-sensitive media to an image of said copy board items;

(h) a processor for developing said photo-sensitive media;

(i) second feed means for feeding the exposed photosensitive media from said platen into said procesor after the actuation of said means for exposing;

said detector means further comprising a first and second light detector positioned on one side of said imaging plane, means positioned on the other side of said imaging plane for illuminating said first and second light detector, and logic means coupled to said light detectors for initiating the halting of the operation of said first feed means when the amount of light detected by said first detector is sharply attenuated with respect to the light detected by said second detector.

2. The combination as set forth in claim 1 wherein said first and second light detectors are mounted upon a movable element which may be selectively moved with respect to said imaging platen thereby to change the length of photo-sensitive media fed by said first feed means.

3. The combination as set forth in claim 2 wherein said movable element is a pivotable arm which pivots aiaciut an axis perpendicular to the surface of said imaging p a en.

4. Photocopy apparatus comprising:

(a) a copy board for supporting items to be reproduced;

(b) means for illuminating said copy board;

(c) an imaging platen having an imaging plane associated therewith;

(d) means for focusing images of said items upon said imaging platen;

(f) detector means positioned along said platen for detecting the presence of the leading edge of said photosensitive media and for halting the operation of said first feed means upon the detection of the leading edge of said photo-sensitive media;

(g) means for exposing said photo-sensitive media to an image of said copy board items;

(h) a processor for developing said photo-sensitive media;

(i) second feed means for feeding the exposed photosensitive media from said platen into said processor after the actuation of said means for exposing;

said second feed means including a flattened roller together with positioning means for maintaining the surface of the flattened portion of said roller adjacent to the surface of said imaging platen without touching said platen when said second feed means is deactivated and drive means for rotating said roller a predetermined whole number of revolutions upon the activation of said second feed means.

5. The combination as set forth in claim 4 wherein said positioning means maintains the flattened surface of said roller substantially parallel to the surface of said imaging platen.

6. The combination as set forth in claim 4 wherein the ratio of the length of the line extending perpendicular to the flattened surface of said roller and through the center of said roller to the circumference of said roller over the diameter of said roller is between .7 and .9.

7. The combination as set forth in claim 6 wherein said ratio is 7:8.

8. A photocopy machine comprising:

(a) an imaging platen, a pivotable door having a copy board thereon for supporting items to be copied; (b) means for imaging said copy board upon said imaging platen when said door is in a closed position with respect to said machine;

(0) means for pivotably supporting said door at a lower portion of said door but not at the end thereof to partially counterbalance said door about said pivot means and to cause the lower portion of said door to extend inwardly of said machine when said door is substantially horizontally oriented in its open position;

(d) illumination means for illuminating said copy board; and

(e) means for positioning said illumination means under the lower portion of said door when said door is horizontally oriented in said open position to thereby protect said illumination means and prevent said door from extending a considerable distance from said machine.

References Cited 2,735,335 2/1956 Shaw 9514 3,357,337 12/1967 E. H. Land et a1 9594 NORTON ANSHER, Primary Examiner W. A. SIVERTSON, Assistant Examiner US. Cl. X.R.

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