US2827826A

US2827826A - Photographic printing apparatus

Info

Publication number: US2827826A
Application number: US428236A
Authority: US
Inventors: Paul D Dale; Warren S Ferris
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1954-05-07
Filing date: 1954-05-07
Publication date: 1958-03-25
Anticipated expiration: 1975-03-25

Description

March-25, 1958 P. D. DALE ET AL 2,

PHO TOGRAPHIC PRINTING APPARATUS Filed May '7, 1954 5 Sheets-Sheet l PAUL D. DALE MERE/V 5: E RR/S N VEN TORS BYM'Y zzr/ ATTORNEYS March 25, 1958 P. D. DALE ET AL 2,827,826

PHOTOGRAPHIC PRINTING APPARATUS Filed May 7, 1954 v 5 Sheets-Sheet 2 A 7' TORIVEYS P. D. DALE ET AL 2,827,826

PHOTOGRAPHIC PRINTING APPARATUS March 25, 1958 5 Sheets-Sheet 5 File d May 7, 1954 Fig.6A

5 5 mm H MmN M 3 9 /N m MR March 25, 1958 Filed May 7, 1954 PHOTOGRAPHIC PRINTING APPARATUS 5 Sheets$heet 4 F ig. l0

F kg. 9

\l JUN 54 3 o 8/ 85 94 PAUL 0. DALE WARREN s FERR/S INVENTORS BY 2k 7 ATTORNEYS March 25, 1958 P. D. DALE ET AL 2,827,826 Y PHOTOGRAPHIC PRINTING APPARATUS Filed May 7. 1954 5 Sheets-Sheet 5 END 0F- PUSH BUTTON FOR Fly. /2 ORDER LAMP END-OF- OROER MAR/r flow OPEN 7 iii?! N NORM OPEN sw/rOREs CLOSED WHEN YEAR 7 EVE/Z7f7i5PECT/VE ExPOsuRE- LAMP v m g; NORM sELE N6 sw/rOR 0F 2 SWITCH ON /3O A 4| A LAMP PLATBV sR Pr r 9/ my W NORM.

OPEN MONT/1' 1/? MAC. L

99 "OZ- N NO- Burr? LAMP NORM OPEN 9/ Pus RurrON POR 525 R 5MP H r I E END-OF- OROER MARK 9/ A NORM OPEN IO/ //2 NO+ BUTTON LAMP 9/ NC+/LNORM. OPEN JSWITCHES OLOsEO wHENEvER YEAR LAMP SPECT/VE ExPOsL/RE SELECT/N6 s ITCH 0F OONrROL u /r IS OEPREssEO 8 OAM OPERAT O R sw/rOR ON I03 NC BUTTON LAMP PLArEN SHAFT NC #4: NORM OPEN NORM. OPEN v 3 c /04 MONrM LAMP //5 MAC ,5 I s/fl I 99 /05 NO- BUTTON LAMP Nc- 9/ NORM. PEN N06 /OO PAUL O. OALE WARREN 5. FER/W8 I INVENTORS United States Patent PHOTOGRAPHIC PRINTING APPARATUS Paulf'D. DalewandWarremSrFerris, Rochester, N. Y., as-

signol's to .Eastman Kodak; Company, Rochester, N. -,Y,., a corporation of N ew Jersey Application May 7,"1954,"S erial No. 428336 :3 Claims. (Cl. 8.8.24)

The; present invention relates to photograplii ptint ns pp Capable ofpm u n di er n expc re ond "tions, and particularly tovthe combination with such a printing apparatus of a code ident fying vprinter which by which relatively unskilled ,operatorsare ,able 1110711311 out photqgraphic printsat a relatively ,rapid .Iate. ,LIn order to make satis'factoryprints fromallkinds .of negatives, these ,printers .are. provided with mean's fornselectively varying the exposure and ,by means of which the operator can adjustthe-exposureafter having inspected the negative andjjudgedwhat exposure correction-might be necessary to produce: a .satisfactory print fromeQarticular negative. At :therend. of, the .day, .or.,after. a quantity .of prints have been mafde on the vprinter,,the

. printsarerthenrprocessed totdevelop out-the latent images.

Upon inspection .of the ,finished prints, there eme generally; found. many which are-not satisfactory. and ,which requireareprinting. If the prints, havenozidentification code-on them toindicate what.exposurewas given them .inthe printingoperation, .thezinspectorahas no-.- way;;of v judging what correction is required and mayneven order a reprint of the-negative .at the same-exposure which was originally, given.

The-primary object of a the ;present ,invention isato pro- -vide a photographic printer which-is capable of ggiving different exposures throughoperationof aselector means with a .code identifyingmeans WhiChFWiIlX eCQIdZQ the final print a code from which the exposure given;:during printing canbe readilyidentified.

..A further object is to provide a; photographic printing apparatus with .a print coding device which operates automaticallyand requires no separate operation ,or thought on the part of the person operating the printer.

Another object is to provideoa print coding device which isso designed that it can be supplied .as an accessory and can be readilycombined with existing printing apparatus.

, And still another object is to provide a print coder which is in effect-a miniature multi-compartrnent printer positioned in the'printing apparatus to expose identifying data on the margin of "the print, each' cornpartment constituting-a miniature printerincludingits own lamp and a transparency bearing an identification code corlamp is illuminated.

And yet another objectof the invention is-toprovide each lamp circuit of the code printer with a normally open switch and to .combinezthese switches with the exposure selector of the main. printer in such a way'that a certain'one of the lamps of the code printer Mill -be ready for. illumination foreach setting .ofi the exposure selector. The actual illumination of the -:appr0priate invention;

asz'zzsze Batente d AMar. 25, 1&58

"ice

'2 lamps of the .code printer is then effected by closure of a switch in the power supply for the individual lamp circuits uponthe operation of the printing apparatus to 'rnake the primary exposure.

A still further object is to combine the code printer with the rnainprinter'in such a way that the switch controlling the. energization of the lamps of the code printer is operated by a moving partof themain printer whereby the code exposure is effected automatically by norrnaloperation. ofthe main printer and requires no separate thoughtoractonthe part of the operator.

A further object is towprovidea code printer by means of which a distinctive mark can he placed on one of the end prints of each roll of negatives for reference when .the strips-are cutinto individual, prints, and/ or by ,means of Whihthemonthand year when thepn'nt was made ;can1be,reeOIded,ontheprint;as aservice to the'customer and also ,as a .nieans vfor orienting .and disguising the .lidentifyinacode.marks- [The novel featnres that .we consider characteristic of .ouramlt t iiqn are set forth with particularity in the ap- -,pend.ed ,.claims. Ihe inventionitself, however, both as to .itsnorganization andits methods of operation, together w thadditional .obiects andadvantages thereof, will best ,be understood from the -following description-when read .invconnectionwith; t e ac mpanying drawings, in which:

fig. 1 'is..a sche at perspe t v tv e r no .tiqn :of .a conventional projection type photographic pr nteruncorporating Ta code printer combined therewith in accordance with a preferred embodiment of the present Fig. :2 is ;a diagrammatic.- view, on ;a reduced scale,

.showit ggthe entire optical path of a projection :-printer ,of which.only ;the top portion is shown-in Fig. 1;

Iiig. ,3 is an enlarged perspective view of :the top por- .tionoflthe .printerfrom;the ;rear and showing thev motor drivempartof the printer which ,operates :the printer platen and ins tigates -the exposure;

Fig. 3A is a schematic-wiring ;.diagram. showing 1 how the motor-fordriving the printer platenbetween. its two positions isautomatically stopped when the platen reaches reach-of its twopositions andis manually started from each position;

Fig. =4;is aside elevationalview showing the platen moving mechanism of the printer, and with the platen -;in its raised posi tion abovetheprinting plane;

Fig. 5 corresponds toFig. 4 but.shows the-platen in r a lowered position;

Fig. 6 is 'an enlarged perspective view showing the push buttons for selecting the printing exposure and the combination thereof with the lamp switches of the coding printer;

Fig. 6A isan enlarged longitudinal section taken substantially on line 6A6A of Fig. l, and showing the code printerfin relation to the exposure plane;

Fig.'7;is an enlarged detail, partly in-section, showing how the operating arm of the normally open switch in the powersupply of the code printer lamps is constructed so that-.theswitch is not closed during the movement'of the oscillating. shaft ofthe main printer in the direction -.comme.nsurateto a lifting of the platen;

exposure-control of the printer;

Fig; 11.is a schematic wiring diagram .of-the code printer when used with a primary printer having three push buttons for controlling the exposure; and

Fig. 12 is a schematic wiring diagram of a code printer which might be used with aprimary printer having five push buttons capable of producing five difierent exposure conditions. t

Generally speaking, the present invention has to do with providing a conventional photographic printing apparatus which has means allowing the operator to selectively vary the exposure with a print coder for recording code marks on the finished photographic prints to indicate which exposure theoperator selected in making the print. This print coder is made in the form of an accessory so that it can be readily combined with any existing printer. When combined with a printing apparatus, it functions automatically in response to the normal printing operation and requires no additional thought or operation on the part of the operator.

While this print coder can be' readily combined with' any type of conventional printer (projection or contact) and having any type of selective exposure control (electronic or manual), for purposes of disclosure we have shown it combined with a well-known type of projection printer having an electronic exposure'control including a photoelectric cell. As schematically shown in Fig. 2, such a printer comprises a printing lamp 10 positioned to illuminate a record 11 to be printed, which record is imaged by a projection lens 12 on a light-sensitive photographic material 13 supported in the exposure plane. The duration of the exposure is controlled by an electronic exposure control circuit, to be later described, which includes a light-sensitive cell 14 onto which light from the projected record 11 is directed by a beam splitter 15.

The upper part of the printing apparatus includes a housing 16 having a top wall 17 provided with a light opening and is adapted to support different sized paper or printing masks 18 having a printing aperture 19. These printing masks are adapted to support the lightsensitive paper in the exposure plane, and paper guides 20 may be provided at the margins of the printing mask to help in locating a sheet or web of paper in proper relation to the printing aperture. In a printer adapted for handling cut sheet paper, as the one disclosed happens to be, a paper platen assembly is provided which is adapted to be moved between a raised, or loading, position and a lowered, or printing, position. This platen assembly, see Figs. 4 and 5, comprises two pairs of substantially L-shaped

platen supporting arms

22 and 23, there being one pair of these arms at opposite sides of the platen. The rearmost arm 22 of each pair is fixed at its intermediate point to an oscillatable drive shaft 24 which extends across the back of the housing adjacent the rear top corner thereof and is journalled in

opposite side walls

25 and 26 of the housing. The front arm 23 of each pair is journalled at 27 in the side wall of the housing. Pivotally mounted at the upper end of each of the

arms

22 and 23 is a platen supporting bracket 28 which moves between the raised position shown in Fig. 4 and the lowered position shown in Fig. 5 when the shaft 24 is oscillated substantially through 90. The platen pad 30 is mounted on this platen bracket 28 by four screw studs 31 located at the four corners, said platen pad being slidable on said studs and urged downwardly by coiled compression springs 32 surrounding the studs 31. This spring mounting of the platen allows the platen to hold the paper down fiat in the exposure plane with only spring pressure even though the platen moving mechanism is adjusted so as to force the platen too hard against the printing mask. Pivotally'mounted on the other ends of L-shaped

arms

22 and 23 is supporting plate 33 which moves out of the projection beam when the platen is lowered, see Fig. 5, and moves up to cover -.the aperture 19 inthe, printing mask when'the platen is is moved to its raised position.

raised, see Fig. 4. The primary purpose of this supporting plate is to prevent the operator from pushing the sheet of paper through the aperture in the printing mask when loading or unloading the printer, although it will serve to some extent as a shutter to prevent any light from striking a new sheet of paper during the negative judging operation.

While this platen could be manually operated, it is. common practice to drive it between its two positions by means of a motor. To this end, as shown in Fig. 3, a small motor M is mounted on the outside of one side: wall of the housing 16 and drives a crank 35 which is: connected by a link 36 to an arm 37 on the end of shaft 24. Through this drive connection a complete rotation of the motor shaft, or motor crank 35, will only oscillate shaft 24 through substantially 90, and cause movement of the platen between its two positions. After the negative and sheet of paper are placed in the printing plane, a switch is operated to make the exposure. This involves moving the platen to its paper holding position, turning on the printing lamp for a selected time after which the printing lamp is extinguished and the platen While ordinarily the motor driving the'platen is automatically started at the completion of the exposure to raise the platen, since such a system is rather complicated and is outside the present invention, we have chosen to show this function as being more or less manually accomplished by a simple struc- 'Fig. 3A, these two switches are connected in series in one branch of the supply circuit to the motor M and are selectively shunted by a manually operated single-pole "double-throw switch 41 also connected in the motor supply circuit. When the switches are in the condition shown in Figs. 3 and 3A, the motor has stopped with the platen in a lowered position. After the exposure is completed, all the operator has to do is throw the switch 41 I to its other position and the motor will start and raise the platen. When the platen reaches its full raised position, the cam disk will have rotated 180 and the high point 38 thereon will engage and open switch 39 whereupon the motor will again stop. To start the next exposure, the switch 41 will then be thrown back to the position shown in Fig. 3A at which time the motor will start, lower the platen, and will be stopped with the platen in the lowered position upon the opening of switch 40.

In order that the exposure will be automatically started when the platen reaches its lowered position without any other operation being required on the part of the operator, the switch 42, which is a single-pole double-throw switch, and is used forinstigating energization of the printer lamp 10, as will be fully hereinafter described, is mounted on the side wall 25 of the housing. This switch is adapted to be engaged and moved from its normal position byan adjustable screw 43 fixed to arm 44 pivoted at one end on a stud 45 extending from the side shaft 24 of the platen.

when the shaft 24 moves to a position to raise the platen,

through a link 46 pivoted at one end 47 to the arm 44 and at the other end on an adjustable screw 48 movable in a slot 49 in a cam 50 fixed to the end of the drive By virtue of this connection,

arm 44 is pivoted upwardly about its pivot point and away from' switch 42 whereupon it is allowed to open and shut off the printing lamp. Conversely, when the shaft oscillates in its other direction to a position where ,it lowers the platen, the arm 44 pivots downwardly to .theposition shown in Fig. 3 and wherein the screw 43 thereon engages and closes switch 42 to turn on the printing lamp. 'By adjusting screw. 43 and/or screw 48 invslot- 49, theiswitcht fli can be'z'made tot'open justms :elhgi platen reaches its lowered position. This. driveclinkeagetisealsoeused to perform two otheroperations-which are *wellrlcnown 1in commercial printing 4 apparatus I although not particularly pertinent --to the;present .invention. First of-all,-arod '51 pivotedto the link 46 at 52 extends downwardlyand-is connected to a swinginglight ..shield, not shown, and which is swung into the projected beam-when the, platenwis' raised and: is swungoutv of the "beam when the platenqislowered. Secondly a' bar 53.

The positive :direction; of. the

,rcurrent-flowtist.fromanode to cathode, as indicatedon .sshieldiand' thepivoted member of the, negativecarrieriattemptingto move into their-normal positions.

.The. printing apparatus. can be; provided with; any one of; several known exposure control systems which canbe oselectively; adjusted to give different exposureszarld which can be'selected by the'operator after judginggthe charv acteraofgv the negative to be printed. For;purpose.:of;illustration Wehave. shown; the; printer-equipped -withi a ,photoelectric control unit having a .timingpcondenser which controls the cut-oft of the printing lamp. .srAschernaticcwiring diagram of such a controlunit is.;shown in -Eig. :lOaandits function will be clear'from the.;descripvtioniof the operat-ing cyclewhich will now 'be;g-iven.

Prior.-to the: time an.exposuresisrstarted, .the .switch r42 -is in the normally closed: position, and a ivoltagexjs -..-developed:across the :three potentiometers:P ,:P .and P which renders .the slidingtap. positive with respect .to-xthe :cathodeof the 6P5 tube. The switch-.42. is 'the' one .tmounted on :theaside ofitheprinterihousing to be; operated 'byrtheish'aft 24. The 'three' potentiometerstare .used to :provide threedifierent.exposureswhich are designated N,.

"N;;and N+. :.The. particular exposure chosen-depends cupon which" ofJthe three switches: designated N, N -and N+1 is:closed by the operator. Since the grid- 60 of the 6F5 tubeis connected to'one'of the taps of the potentiomxetersnwhen. one; of the switches N, N+ or N- is closed, itheggrid' is also positive-With respect to the cathode-and 1, thergridi current :flows-inthe tubethe positive direction :of current flow is from the grid to the cathode-.and"the gridris' acting likea plate. This current continues tollow mntiLFthe' -timingcondenser I 61 becomes charged to a ivpotentialapproximately equal to the potential difference -betweernthezca'thode 62 of the6F5 tube and the tap on tithe potentiometer connected into the circuit, with the'grid ;side;ot the condenser negative with respect tothe tap on iztheitpotentiometer. lThis charging-process takes place very rapidly, and under normal operating conditions the ecircuit-istin astate of equilibrium long beforean exposure isstarted.

when'the switch 42 'isdepressed upon lowering or the platemto makean exposure, the voltage is removed from the selectedpotentiometer whose -tap assumes the po- -.-tentialof thecathode 62 of the 6P5 tube. Since the grid sideof the timing condenser was negative with respect to the tap, it is -'now negative with respect to the iS'dire'cted tolthe phototube 14 bythe beam splitter .15 and timing condenser.

the diagram by arrow 2. This current discharges the When the potential dilference across the timing condenser has dropped to less than cut-ofifor the 6P5 tube, this tube conducts and produces a voltage .drop'across its plate resistor 66 which renders the grid 65 OfIhC' L6tube sufiiciently negative to stop its plate current andthe relay 64 drops out, turning out the printing light. The phototube current is proportional to the amount of light incident upon its cathode so that the tirningwcondenser is discharged more quickly for the thinner negatives. The potentiometers control the amount of. charge. in the condenserand are adjusted togive three different'exposure levels, one for normal negatives (N), one, for negatives requiring less than normal exposure ,(N,), and'.the other for negatives requiring more than :normalexposure (N+). -When the exposure has been .terminated, ,the'switch'42 is released by movement of the wplatenuto its raised position, and the cycle begins again With the;charging of the timing condenser 61 by the grid Current of the 6P5 tube.

TheQthreeswitches N, N- and N+ may take the form ofa commercially available selector switch of the type showngenerally at 67in Fig. 6.

el-As shown, this selector switch comprises three separate slides-68 which are guided to move vertically'in slots in ,spacedtop and bottom rails 69 and 70 respectively.

.Eachelide.is'normally moved in an upward'direction by: ac oil spring'71 located between the slide and-the An intermediate rail 72 is mounted inislots in. end plates 34 to move horizontally, andthis rail-nisi-normally movedto' the left, :lookingat Fig.- 6, by

. aleaf spring 73 fixed at one end to one of the end plates 34 and having its free end engaging the end of the rail. Each ofthegslides 68 extends through an aperture 74 in .thetaintermediaterail 72, said aperture having astraight xedge which is adapted to, snap into a notch 75in the edge ;of:each slide-as it is. depressed and thereby hold the slide in a depressed position. The edge of eachslide adjacent .thenotch therein is provided with a cam surface which cams-the slidable rail 72 against its spring 73 just and allows it to rise as another slide is depressed and latched in a depressed position. Each slide 68 hasiiixed theretoa wall 76 made of an insulating material, i.'. e. phenolic, and this wall serves to separate twoswitchcontacts, not shown, which would be mounted on the rear phenolic wall 77 and to which the leads of the circuit theyare to control would be connected. Aconductor strip 78 is fastened to and extends through each wall 76 in such position that when the slide is depressed the conductor strip will engage and short the switchcontacts on opposite sides of the wall and thus complete thecircuit. The push buttons 79 fastened to the top of the respective slides 68 are marked with designations N,.N and N+ to indicate the different exposure, selecting switches of Fig. 10 which they are adapted to control.

Coming now to the present invention, the print coder according to the present invention comprises a multi-compartrnent contact printer, indicated generally at 80 in Figs. 1 and 6A, which is mounted directly beneath the printing masks of the printer and adjacent the aperture 19 therein soas to print on the margin of the photographic print a .latentimage ofa code by which the selected exposure can be identified upon development of the print. Such a coded print is illustrated in Fig. 9 where the first inconspicuous small dot 81 might indicate an exposure of N,

.used primarily to-disguise the code dots 8182 from the purchasers standpoint and to separate the three dots so that they can be readily identified despite the'fact that they are each the same. The last and final mark 84, shown as a circle with a dot in the center, may be used to indicate the first or last print of a roll of film, or of a customers order, in order to aid the processor to keep track of different orders.

Referring now to Figs. 1 and 6A, a code printer for making a code as shown in Fig. 9 consists of a block 85 having six holes 86 drilled therethrough. This block is supported on a metal plate 87 and properly located thereon with its holes aligned with the threaded lamp sockets 88 in the plate by pins 89 extending upwardly from the plate and slidably engaging corresponding bores 90 in the block. A small three-volt lamp 91, of the type used on airplane instrument panels, is threaded into each of the lamp sockets in plate 87 and extends up into the holes in the block. Fixed to the bottom of plate 87 is a plastic plate 92 having bores adapted to frictionally receive the six jacks 93 having spring-pressed contacts for engaging the center contact of the lamps. The entire assembly is mounted on the underside of the top wall of the printer or printing frame 18 by means of flat headed screws 94 threaded into tapped ends of spacer sleeves 95 fixed to the metal plate 87. The printing platen 18 has holes 96 aligned with the holes 86 in the block and it will be noted that these holes are much smaller than the holes in the block so that in effect the illumination at each hole in the printing frame, by virtue of the spacing of the lamps therefrom, will in eifect be the same as illumination from a point source of light. These point sources of light are then transmitted through a transparency or negative 97 which carries the identifying data heretofore described and which data is properly superposed above the several printing compartments of the code printer. Any suitable means can be provided for locating the code-bearing negative above the coding printer, or the several compartments thereof, so that the separate data areas will register with the different ones of the six holes of the block, or the six different stations of the coding printer.

The different lights of this coding printer are hooked into a source of energy in such a way that the two lamps for printing the month and year of the code will be illuminated every time an exposure is made, the lamps for printing the N, the N|, and the N designations will be illuminated only when the corresponding switches N+, N, and N are closed, and the mark indicating the end or beginning of a customers order will be lit only upon aseparate choice of the operator. All of the lamps are so connected to their source of energy that they will be lit only when the platen is being lowered to make an exposure, and then, since the illumination for this code printer reaching the printing plane is so bright in comparison to that reaching the printing plane from the regular printing lamp as to require a shorter exposure time than the regular negative, the lamps of the code printer are only turned on for a portion of the time of the regular exposure of the negative being printed.

To this end, one terminal of each of the six code printer lamps 91 is connected to one side of a threevolt source of power which, in this instance, is the secondary 98 of a transformer whose primary 99 is connected to a 115-volt A. C. supply. Looking at Figs. 11 and 6A, this connection may include lead wire 1G6 and metal plate 87 into the sockets of which the lamps 91 are threaded. The second terminal ofeach lamp, or the center contact thereof, is connected to the other side of the transformer secondary by

leads

101, 102, 103, 104, 1% and 1116, respectively. Leads 163 and 105 which connect the lamps 91 for printing the year and month, respectively, are unbroken. The leads 102, 104 and 106 leading to the lamps 91 for printing the exposure code include normally open switches N+,'NC and NC- these respective switches are closed. In order that these last-mentioned three switches will be closed when the different exposures are selected, switches NC+, NC and NC take the form, and are mounted, as best shown in Fig, 6. These three switches comprise three pairs of spring contacts mounted on a block 110 and which block is so fixed in a switch housing 111 on the side of the printer housing as to cause the upper and longer of each pair of the switch contacts to lie under the phenolic wall 76 extending from the respective slides 68 of the selector switch 67. When each of the slides 68 is depressed to choose a given exposure time for the printer, the phenolic wall 76 thereof engages and closes the code lamp switch corresponding thereto. For example, in Fig. 6 the push button marked N- is shown depressed, indicating that an N exposure has been chosen, and the phenolic wall 76 associated with this push button has engaged and depressed to a closed position the switch NC- in the circuit of the lamp in the code printer which will print the code on the final print corresponding to this exposure.

The lamp 91 of the code printer for printing the end-oforder code on the film is illuminated only when the operator selectively closes a normally open switch 112 in the circuit thereof. This switch may be operated from a push button 113 mounted in the top of the switch housing on the side of the printer, see Fig. 1, and this button must be held down by the operator while an exposure is being made.

So that none of the code lamps are turned on until the platen is being lowered and before the primary exposure has begun, the volt circuit feeding the primary 99 of the transformer is provided with a normally open snap switch 114 of the type best shown in Figs. 7 and 8. This switch is of the well-known type which is closed by depressing a spring plunger 115 and which plunger can be depressed by applying pressure to the end of a spring loaded pivoted arm 116 to close the switch, see Fig. 8. In order to cause the lamps of the code printer to be automatically turned on at the time a primary exposure is to begin, we mount the switch 114 on the side wall of the printer housing in a position to be engaged and operated by a cam 117 fixed to and moved by the oscillatable platen shaft 24. So that the switch will be closed only when the shaft is moved in a direction to lower the platen, the end of the switch arm 116 is provided with a lug 118 pivoted at 119 to the arm and including an extension 120 which positively engages the arm when engaged by the cam while moving clockwise, thus casuing the arm as a whole to be depressed to close the switch. This construction also permits the lug to pivot independently of the arm when engaged by the cam when moving in a counterclockwise direction, see Figs. 7 and 8, with the result that the switch 114 is not closed at this time. A roller 121 is rotatably mounted on the end of lug 118 to be engaged by the cam 117.

Since the light from the lamps 91 is relatively much brighter than the light used for making the primary exposure, it follows that the exposure time required in the code printer is less than that required in making the main print. Furthermore, since the printing conditions in the code printer are constant from one exposure to the next, whereas the exposure in the primary printer may be selectively varied, the exposure time in the code printer should remain constant. The switch 114 and the cam 117 should be relatively adjusted so that the cam in moving in a clockwise direction will engage and close the switch and then pass by the roller 121 to allow the switch to reopen. To provide for this adjustment the cam is adjustably mounted on shaft 24 by means of a yoke 122 and a clamping screw 123, see Fig. 8. The duration of exposure in the code printer will depend upon the contour of the earn 117 or how long the cam holds the switch 114 closed before passing beyond the, roller 121. We have xposure. Ihe--necessaryovertravel of shaft 24 toallow cam 117 to pass-beyondroller-120 and #thus allow switch 5 114 to reopen willbe obtained by virtue of the four compression springs 32 acting onthe platen. In the event the photog'raphiopaper isbeing fed across *the'printer top in the form of a long web from a supply roll to a take-up roll, as is well known, then the strip of paper can be held onto the printer top under sufficient tension to keep the paper in good enough contact with the code negative to insure a good contact print even though the platen is not holding the paper down on the code negative during the exposure of the printing code. In fact, the present invention could be combined with a projection printer having a roll paper head of the type shown in U. S. Patent 2,541,013 in which the web of paper is merely fed across the printing plane under tension and held in contact therewith by a floating platen rather than by the use of an oscillatable platen of the type here disclosed. In such a case the oscillatable shaft 24 would not need to raise and lower the platen but would then be used only to operate switch 42 to start the exposure, to open and close the negative carrier, and to move the light shield from the light beam, as is well known.

When using the three button exposure control shown in Figs. 1 and 11, it is common practice to depress two adjacent push buttons simultaneously in order to obtain an intermediate exposure step. This will light the corresponding two lights 91 on the code printer. To avoid the necessity of having to push two buttons to obtain an intermediate exposure a five button exposure switch arrangement might be provided to obtain these five steps by merely pushing a single button for each step. In Fig. 12 we have shown how a five bush button switch might be connected into the same code printer having only six lamps and giving the proper code for the added two intermediate exposures.

In this embodiment the switches marked NC+, NC and NC are directly connected in the respective circuits of the NC+ button lamp 91, the NC button lamp 91 and the NC button lamp 91. The (NC+) switch, which in this instance corresponds to the intermediate exposure which would have been made by closing both of switches NC+ and NC of the three button switch embodiment of Fig. 11, operates a double contact switch 130 which connects both the NC+ button lamp 91 and the NC button lamp into the circuit. Likewise the (NC') switch operates a double contact switch 131 which connects both the NC button lamp and the NC' button lamp into the circuit. In other words, with the five switch arrangement of Fig. 12, the same code will be printed by individually pushing buttons (NC+) or (NC) as would be printed with pushing both the NC+ and NC buttons, or the NC and NC buttons, respectively, of the three button switch arrangement of Fig. 11.

The operation of this printer may be briefiy summarized as follows: With a negative in the printing gate, not shown, of the printer, the operator judges it for subject matter and depresses one of the push buttons N, N or N+. If the depressed button happens to be the N button, as shown in Fig. 6, this action also closes the switch NC of the code printer circuit, see Fig. 6. Now when the switch 41 is actuated to initiate an exposure cycle, the oscillatable shaft 24 is rotated clockwise by a motor M. The cam 117 on shaft 24 actuates the snap switch 114 through its roller arm to supply line voltage to the primary 99 of the transformer housed in the switch housing. The secondary of the transformer thus provides a three volt potential to the lamps in the date compartments of the code printer and to the lamp controlled by the NC switch to print the code corresponding to this compartment on the film. Power may ated-switch @112 .through push-button 113..in orderto provide .Ithe end-of-order .code. mark 84. The primary ,exposureofthe printing apparatusv is started when switch '42.is actuatedlby. arm 44 drivenfrom the oscillatable shaft 24. Afterthe exposure is completed by the photoelectric control unit having'shut on the printing lamp, the switch 41 is thrown in the opposite direction to cause the motor M to drive the shaft 24 through another to reset the parts for the next printing operation. If more than one selector switch button is depressed to obtain an intermediate exposure, as is common practice, a combination of code marks will result. With the five button switch selector arrangement shown in Fig. 12, these intermediate exposures, or combinations of code marks, can be obtained by depressing a single button rather than a combination of two buttons as is necessary in the three button selector arrangement.

Although we have shown and described certain specific embodiments of our invention, We are aware that many modifications thereof are possible. Our invention, therefore, is not intended to be restricted to the precise details of construction shown and described, but is intended to cover all modifications coming within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. In a photographic printing apparatus including a printing mask for supporting a sheet of sensitized paper in an exposure plane, means for exposing a sheet of paper in said exposure plane to light passing through a negative to produce a primary exposure on said paper; means for selectively varying the exposure to which the paper is submitted and including a plurality of push buttons which may be selectively depressed to alter the exposure; and means for starting said exposure including an oscillatable shaft; the combination of means for printing on said paper, along with the primary exposure, code data for identifying the type of exposure given said paper by reason of the push button depressed, and comprising a miniature multi-compartment code printer mounted directly beneath the printing mask adjacent the printing aperture therein, said code printer comprising a plurality of compartments corresponding in number to the number of said push buttons and the wall of each compartment facing said exposure plane capable of transmitting light; a code bearing transparency covering the light transmitting wall of each compartment and bearing identifying data corresponding to different primary exposures; a lamp in each of said compartments; each of said lamps connected in parallel circuit relation to a power supply circuit; a normally open switch in each of said lamp circuits; means for combining said lamp switches with said push buttons whereby depression of said push buttons will close the switch to the lamp of the code compartment corresponding thereto; a second normally open switch in the power supply circuit; and means actuated by said oscillatable shaft for closing said second switch when the shaft moves to start an exposure.

2. A photographic printing apparatus according to claim 1 in which the means actuated by said shaft for closing said second switch comprises a cam carried by said shaft adapted to engage and close said switch, and means for adjustably mounting said cam on said shaft whereby the time at which said switch is closed relative to the primary exposure can be varied.

3. A photographic printing apparatus according to claim 1 in which the means actuated by said shaft for closing said second switch comprises a cam carried by said shaft adapted during movement of said shaft in one of its directions to engage and close said switch, keep it closed for a given interval depending upon the configuration of the 11 w 12 cam, and allow the switch to reopen; means for adiust- References Cited in the file of this patent ably mounting said cam on said shaft whereby the time UNITED STATES PATENTS at which it closes the switch relative to the starting of V v the primary exposure can be varied; and means for pre- Ig/Iann 1939 5 ryce June 16, 1953 venting said cam from cioslng said switch durlng return I V of said shaft to its starting position. FOREIGN PATENTS 672,033 Germany Feb. 20, 1939