US3774520A

US3774520A - Developing mechanism for microfilm

Info

Publication number: US3774520A
Application number: US00265556A
Authority: US
Inventors: A Smith; I Irwin
Original assignee: A Smith; I Irwin
Current assignee: Canrad Hanovia Inc
Priority date: 1972-06-23
Filing date: 1972-06-23
Publication date: 1973-11-27
Anticipated expiration: 1990-11-27

Abstract

The disclosure of the invention is directed to an improvement in the developing mechanism for duplicating sheets of heat sensitive latent image bearing microfilm. The microfilm sheets are copied by exposing film from a roll through a master microfilm sheet, cutting the exposed film from the roll and developing the film in a heating chamber. The heating chamber contains thermostatically controlled heating elements to maintain the temperature at substantially 285*-290* Fahrenheit for a dwell time of 5 - 7 seconds. The film is continuously moved through the heating chamber by a roller conveyor providing a continuously moving and changing contact area with the film on an emulsionless surface. The film is transferred to a belt conveyor having end rollers no larger in diameter than the rollers in the roller conveyor but having a flat surface to provide cooling for the developed sheets before being delivered to a collection point in the mechanism.

Description

Smith et a];

[56] References Cited-v [54] DEVELOPING MECHANISM FOR MICROFILM [75] Inventors: Alan Smith/New Brighton, Irwin Y L. Irwin, Coon Rapids, both of Minn.

[73] Assignee: Calight,Inc.,Minneapolis h'linn [22] Filed: June 23, 1972 [21] App]. No.: 265,556

[52] US. Cl 95/8 9 R, 95/89 A, 219/216,

. 219/388, 355/100, 355/106 51 "161. CI. ..G03d 3/00 [58] Field ofSearch....- ..95/89 11, 9 11,14;

SSS/100,103,106,-107, 27, 28; 219/216,

v UNITED STATES'PATENTS v 3,557,675 1 1971 86116161.. 355/27 x 3,282,183 11 1966 T111116 e161. 95 14x 3,449,547 6 1969 06661 1666161. ...'219' 388x 3,458,314 7 1969 1.111661112166161... 95/89RX Doyle 219/469 1451 Nov, 27, 1973 Primary Examiner-Richard L. Moses Attorney-Everett J. Schroeder et al. I

[57] ABSTRACT The disclosure of the invention is directed man im- 1 provement in the developing mechanism for duplicating sheets of heat sensitive latent image bearing microfilm. The microfilm sheets are copied by exposing film from a roll through a master microfilm sheet, cutting the exposed film from the roll and developing the film 4 in a heating chamber. The heating chamber contains thermostatically controlled heating elements to maintain the temperature at substantially 285290 Fahrenheit for a dwell time 6'15 7 seconds. Thefilm is continuously moved through the heating chamber by a roller conveyor providing a continuously moving and changing contact area with the film on an-emulsionless surface. The film is transferred to'a belt conveyor having end rollers no larger in diameter than the rollers in I the roller conveyor but having a flat surface to provide cooling.for the developed sheets before being delivvfirecl'to a collection point in the mechanism.

12 Claims, 3 Drawing Figures V l n :DEVELOPING MECHANISM FOR MICROFILM .This invention is directed to a microfilm duplicating mechanism and moreparticularly to the means for developing the exposed microfilm which isheat sensitive and includes a latent image.

' In the duplication process of duplicating microfilm which hasa heat sensitive latent image it has been found that some of these films require a developing time of approximately Sto 7'secondsin a heating chamber forming the developer which renders the plastic ma te rial forming the film substrate to become very soft andpliable'preventing any form of pressure con- By reference to the Figures, and particularly FIG. 1 where a roll of film 10 is suspended upon a spindle 11, it is drawn between an alignment spool12to pass over a film holder 13. Film holder-l3 carries a masterfilm' 14 which is tobe copied A .cover plate 15 is hingedly supported at its rear throughsuitable means so that it may be drawn down tightly upon holder member l3 tact with theemulsion side of the film. Some films are made with a rapid developing time so that heatmay be applied to the film and the filmvpassed through pinch rollers to conduct the film through the developer without having the emulsion separate from the film suband thus hold film 10 in contact with the master 14. A mask 16 below film holder 13 works in conjunction with a shutter mechanism 17 which hasan elongated slot' 20 formed in the center of a'half section of a cylindrical member which has a lamp 21 in the form of an ultraviolet light that causes its rays to be emitted upwardly through the master film to be copied to expose film 10. Shutter member 17 rotates through 180 to -block the light. from being transmitted-through mask 16 permitting light to pass through slot 20 and again strate. However, for the film first described above, any

attempt to pass the film continuously through pinch rollers causes the emulsion to be transferred to the pinch rollers and thus ruin the new film sheet.

Because the film does become 'very pliable, it is necessary to move the film in sucha manner that there is little contact with the conveying mechanism'in. orderto prevent hot or burned spots on the film such as maybe encountered where a flat belt type conveyor may be used to convey'the film through theheat chamber. It is also necessary'toremove the-film from the developer and cause it to cool'on a-flatsurface so that the film sheet remains flat-and' do'es' not incur a P I aflent set? to the film from any sag which may be .imparted through the use of a continuously-'' moving contact member with the film.

, It is therefore a general objec'tof this invention to provide an improved developer of heat sensitive latent image bearing microfilm.

It is'still a further object of this invention to provide adeveloper of heat sensitive latent image bearing microfilm in which the exposed film is moved through the developer having continuously moving and a changing contact'areas engaging the film. f t It is still a further object of this invention to provide means for moving film through a developer by engaging the emulsionless surfaces of the film 'to be cured by heat. 1

It is yet another object of this invention to provide a roller conveyor means to transport the heat sensitive latent image bearing microfilm through the developer. Itis still another object of this invention to provide means for'developing heat sensitive latent imageb'earing' microfilm at a temperature range of 285290,"

'veloper with a dwell time of 5 j- 7 seconds.

These and other objects and; advantages of the invention will more fully appear from the following description, made in connection with the accompanying drawblock the light from passing mask 16. The rate at which shutter member 17 is oscillated provides'an adjustment for the developing time. The shield 17 is pivoted about an axis 22 which permits the 180 movement of the shutter member 17.

After the film has been exposed, the pressure is re leased from cover 15 and film 10 is advanced by a pair of rollers 23 and 24'which are driven by amotor mechanism to causean advancement of film 10 one length of the master-film 14. The film is then stopped and a knife mechanism 25 is energized which cuts the film the'p'roper length." Film 10 is then advanced through a pair of curved guide members 26and 27 until it reaches anotherpair of rollers 30and 31, one of which is driven I by a motor-and the other which. maybe av pinch roller to further guide-and movefilm member 10 through an intermediate pair of

guide members

32 and 33 which causes the film sheet 10 to be moved vertically between

guides

32 and 33. 1 v v I Another pair of

rollers

34 and 35, one of which is a pinch roller and the otherof which is driven through a chain drive connected to the .drivingmotor, causes film 10-to be engaged and propelled downwardly between another. pair of curved guide members 36 and37.

I Guidemernbers 36 and 37 cooperate to change the course ,offilm sheet 10 from a verticaldownward movement to one which is substantially horizontal. Film sheet 10 is then engaged by another pair of rollers .40 and 41 where roller 40 is in the form of a pinch rol- Fahrenheit while conveyingthe same through the deings, wherein like reference charactersrefer to the same or similar parts throughout. the several views, and

inwhich: t

FIG. 1 is a diagrammatic view of the invention showing the mechanism for exposing and developing heat sensitive latent image bearing microfilm;

FIG. 2 is an elevational side view of the heat chamber and conveyor mechanism from the developermecha nism; and I FIG. 3 is an electrical schematic showing the electrical circuit controlling the duplicating mechanism.

.-v eyor and conduct film sheet10 across ler and roller 41 is a driven roller, the driving mecha} nism being a constant speedmotor. A plurality of rolis rotated, roller 71 being disposed adjacent roller of the roller conveyor and having a diameter no larger than roller 50to cause a minimum amount of droop" of the film in transferring from the roller conveyor to the belt conveyor. Another roller 72 rotatably secures the belt in place at theend of the conveyor and film sheet 10 is then-retained by acollector box 80 at the end of conveyor.70 A cover plate 81 is formed about I conveyor to direct any of the aircurrents used generally'to cool lamp 21 from reaching the film sheets 10 the rollers on i and disturbingthem during their cooling period in moving from the developer to the collector box 80.

For a .more complete disclosure of the exposure mechanism and that portion of the duplicatingdevice before reaching the developer in the form of the heating chamber 60 and conveyor 70, reference may be had to a co-pending application entitled Microfilm Duplieating Device? and assigned to the same Assignee.

Developer 60 is in the form of a metal enclosure. 65 which has an inlet opening 66 and an outlet opening 67 through which'film enters and is. discharged. A' i metal barrier68 is secured between the floor of the box 65 and below roller members 41 through 50. Heating elements 61 through 64 are contained with a cavity v69 formed between barrier 68 and the sides and bottom of box 65. A thermostat 73 is disposed on the upper outside portion of heating chamber 60 and is used to control the electrical connections to

heating elements

61 and 62 as shown schematically in FIG. 3.

A drive sprocket 51 is rotatably, secured to case 65" and has seven idler sprockets 52 53, 54, 55 56, 57, and 58 rotatablysecured to housing in cooperation witha chain 59 which engages sprocket teeth found on each of rollers 41 through 50. Sprocket 51 is rotated in such a manner as to cause rollers41 through 50 to pro- 1 10 volts 60 cyclesis applied'to lines 90 and 91 through a master switch 92 which applies current through a fuse 93 and energizes a lamp 94 indicating that theequipment is ready to start developing. it will of course be understood that a lamp switch 95 will also be closed applying current to ultraviolet lamp 21 which is shown diagrammatically in FIG. 1. After an appropriate warmup period, and with a master 14 in film carrier. 13, a print switch 96 is momentarily closed which causes a control relay CR2 in line 2 to beenergized and which in turn closes relay contacts CR2 in line 2 thus forming a holding circuit. Connected in parallel with control relay CR2, is a timed relay TR3 which closes its contacts-up to 1 secondlater, closing eontactsTR3 in line 4. A shutter drive cam. 100 in its at rest position, closes a switch 101 in line 4 thus applying current to timed relay TR4 which applies a pulse for a fraction of a second to a cam solenoid 102. The duplicating mechanism uses a number of motors, several of which are connected to the mechanical drive through the means of a mechanically engaged clutch. The clutches are spring loaded and have a cam or collar control member held duce a movement of film sheet 10 from opening 66 through opening I 67 in the heating chamber 60. Sprocket 51 is connected to a motor 74 through suitable means such as a shaft 75. It may also be desirable to paint the inside of cavity 69-so that a more uniform radiator is formed by barrier 68. Additionally, a conveyor motor 76 is connected to driving roller 71 through suitable means such as a shaft 77.

Motors

74 and 76 are generally constant speed motors and operconveyor .70-without appreciable distortion and upon cooling on conveyor 70, the film will remain in'a flat condition.

Plate 81 may be eliminated if cooling currents of air are not admitted to the area in which the film is conveyed on conveyor 70, it being understoodthat the film must lie flat on the conveyor in order to produce a'flat sheet before reaching the collection point 80 at the end of conveyor 70. I

It has also been found that cavity 69 is heated to the correct temperature of 285 to 290 Fahrenheit by ap-' plying current to

heaters

63 and 64 continuously, the heaters being approximately 200 Watts each; The incremental control needed to keep the temperature variation within the limits just described is achieved with

heaters

61 and 62 which are connected in series with each other through the use of a thermostat 73,

heaters

61 and 62 being of 50 Watt ratings.

OPERATION The control circuit is shown in FIG. 3 in simplified form showing the mechanical structure as controlled by the electrical circuit. To better understand the circuit, the lines appearing between a pair of power lines 90 against rotation through a detentactuated by a solenoid. Upon release for'rotation the clutch may rotate the cam 180 or 360 depending on the number of detents. A clutch 103 is actuatedby solenoid 102, and a motor 104 provides a rotational drive for the clutch. Clutch 103 drives a cam 105 to cause cover 15 to be secured against film carrier .13 and also drives a cam 106 which is used to actuate aswitch,l07 and cause switch 107: to engage the contact on line 10.

Current is also applied to timed relayTRS in line 5, and contacts TRS areclosed applying current through switch 107'to a shutter solenoid 110. A clutch 111 is mechanically connected to solenoid 1 10 and is also mechanically connectedto a variable speed motor 112 which causes a rotation of shutter17and switch cam 100. After cam 100 rotates, the contacts of switch 101 are broken and the circuit is broken to relays TR4 and TR5 which opens the circuit to the shutter solenoid 110. After the shutter has contained its 180 movement through an eccentric arm, it-comes to restlwith the light from lamp 20 being blocked from entry to the film'carrier and'master film14. However, when cam 100 rotates 180, switch 101 is again actuated momentarily which again energizes relays TR4' and TR5 to film 10and allow it to be drawn through between the cover 15 and holder 13.

Switch 107 now engages its contact in line 9, apply-' ing current to a metering roll solenoid 113. A clutch 114 is engaged by solenoid 113 and mechanically connects a drive motor 115 through an output shaft which and 91 are labeled at the left, line numbers designating the particular electrical circuits which will be used to identify the components therein. Alternating current of through the guide members. As film 10 is advanced by motor and metering roll 24, cam 116 permits a switch 117 in line 9 to engage another set of contacts,

connecting it directly to a control relayCR6 in line 6. A holding circuit is created in line 6 through a pair of normally open contacts CR6. I

connected with the line, energizing timed relay TR7 through control relay contact CR6 in line8. Timed relay TR7 has two forms of delay, one of which occurs while the relay coils are energized and the other delay follows de-energization of the coils for a period of time before returning the circuit to the condition shown in FIG. 3. Line 7 forms the holding circuit during the on delay and at the endof the off delay, relay TR7 is returned to the condition shown in; the drawing. Upon energizing timed relay TR7, the normallyclosed contacts'in line '1 are open, thus breaking the circuit to CR2, TR3, TR4, TRS, and CR6. In other words, the

film has been advanced alength of themaster film and the sequence is ready to berepeated. Through the use of a cut switch 120, in line 12, a solenoid 121 is actuated which is directly connected to knife 25 to sever I the filmat thatpoint.

. It may be desirable'to adjust the speed of the shutter motor and this may be accomplished through the use of a mechanism such as the Dayton Triac Control,1No.

I 4x796 which is an'SCR control for use with motor 112 and is designated as a speed control 122.

As explained briefly before, heat is maintained in the Iheatingchamber through the

useof heaters

63 and 64 and the heat variation is maintained and controlled through the use of

series heaters

61 and 62 controlled by thermostat 73. I

The developer motor 74 drives the roller conveyor within the developer causing the sheet film to be delivered to conveyor 70 which is driven by motor 76.-

It will of course be. understood that mechanism-may be operated in an automatic'mode and that numerous copies may be made by the use of a counter. The disclosure of such a mechanism is found in the co-pending application mentioned previously.

vIt will, of course, be understood that various changes may be made in the form, details, arrangement and pro-' portions of the without departing fromthe scope of the invention which consists of the matter shown and described herein and set forth What is claimed is: y 1

1. An improvement in a' duplicating mechanism for heat sensitive latent image bearingrnicrofilm having a film holder for holding such microfilmto be duplicated I with a film exposure device disposed inoperable position in spaced and confronting relationship therewith,

' said film exposure device cooperating with means for supplying film to be exposedto the film exposure'device and havinga cutter operably disposed and controlled to deliver selected lengths of exposed microfilm outlet openings and having continuously moving and changing contact areas engaginga substantially emulsionless surface of such selected lengths of microfilm, said transport means operating at a I speed permitting the latent image in such film to be fully developed; 3

in'the appended claims.

, '6 c. and a conveyor mechanismcomm'unicating with said film transporting means and said outlet opening of said heating chamber having a flat support thereunder conveying such developed film to a collection point, said conveyor mechanism conveying such film in a flat condition until the film emulsion is set and the latent image is fixed therein. I 2. The structure set forth in claiml wherein said heating chamber includes: i I I a I thermostatic control means connected to less than I the total of said plurality of heating elements providing incremental changes in] heat variations within saidheatirrg chamber. I r I 3. The structure set forth in claim 1 wherein said inlet and outlet openings in said heating chamber are sub stantially in horizontal opposition to each other. I

4. The structure set forth in claim 1 wherein said film transporting means includes roller conveyor means constructed and arranged to convey such selected '5. The structure set forth in claim 4 wherein said con- I veyor mechanism includes an endless belt conveyor having at least a pair of rollers at each end thereof, the end communicating with said film transporting means having a roller no larger in diameter than the rollers in said roller conveyor means. I 6. The structure set forth in claim 1 whereinsaid heating chamber maintains a temperature range be.- tween 285 and 290 Fahrenheit 1. The structure set forth in claim6 wherein said film transporting means moves such selected lengths of microfilm through said heating chamber in'substantially I 5 7 seconds.

8. The structure set forth in claim 2- wherein said heatingchamber includes: Y a cavity containing said plurality of heating elements,

said cavity being disposed beneath said film transporting means. v I 1 i 9. The structure set forth in claim 4'wherein said film 40 transporting means includes: t

lected lengths" of exposed. microfilm are engaged I being exposed to the heat from said heating cham ber.

' image-bearing microfilm comprising:

fonned therein admitting and discharging respectively selected lengths of exposed and developed microfilm, said chamber including a'plurality of heating elements disposed generally opposite the emulsionsurface ofv such selected lengths of ex-' posed microfilm;

. film transporting means constructed and arranged within said heating chamber between said inlet and I outlet openings and having continuously moving I and changing contact areas engaging a substantially emulsionless surface of such selected lengths of microfilm, said transporting means operating at a speed permitting the latent image in such film to be fully developed;

. and a conveyor mechanism communicating with said film transporting means and said outlet opening of said heating chamber having a flat support thereunder conveying such developed-film to a collengths of film in'substantially a horizontal manner.' I

and moved onto said roller'conveyor means before ,a. a heating chamber 'havinginlet and outlet openings ner.

'12. The structure set forth in claim 10 wherein said heating chamber maintains a temperature range between 285 and 290 degrees Fahrenheit and said film transporting means moves such selected lengths ofmicrofilm through said heating chamber in substantially 5. 7 seconds.

Claims

1. An improvement in a duplicating mechanism for heat sensitive latent image bearing microfilm having a film holder for holding such microfilm to be duplicated with a film exposure device disposed in operable position in spaced and confronting relationship therewith, said film exposure device cooperating with means for supplying film to be exposed to the film exposure device and having a cutter operably disposed and controlled to deliver selected lengths of exposed microfilm from said film exposure device, said improvement comprising: a. a heating chamber having inlet and outlet openings formed therein admitting and discharging said selected lengths of microfilm, said chamber including a plurality of heating elements disposed generally opposite the emulsion surface of such selected lengths of exposed microfilm; b. film transporting means constructed and arranged within said heating chamber between said inlet and outlet openings and having continuously moving and changing contact areas engaging a substantially emulsionless surface of such selected lengths of microfilm, said transport means operating at a speed permitting the latent image in such film to be fully developed; c. and a conveyor mechanism communicating with said film transporting means and said outlet opening of said heating chamber having a flat support thereunder conveying such developed film to a collection point, said conveyor mechanism conveying such film in a flat condition until the film emulsion is set and the latent image is fixed therein.

2. The structure set forth in claim 1 wherein said heating chamber includes: thermostatic control means connected to less than the total of said plurality of heating elements providing incremental changes in heat variations within said heating chamber.

3. The structure set forth in claim 1 wherein said inlet and outlet openings in said heating chamber are substantially in horizontal opposition to each other.

4. The structure set forth in claim 1 wherein said film transporting means includes roller conveyor means constructed and arranged to convey such selected lengths of film in substantially a horizontal manner.

5. The structure set forth in claim 4 wheRein said conveyor mechanism includes an endless belt conveyor having at least a pair of rollers at each end thereof, the end communicating with said film transporting means having a roller no larger in diameter than the rollers in said roller conveyor means.

6. The structure set forth in claim 1 wherein said heating chamber maintains a temperature range between 285* and 290* Fahrenheit.

7. The structure set forth in claim 6 wherein said film transporting means moves such selected lengths of microfilm through said heating chamber in substantially 5 - 7 seconds.

8. The structure set forth in claim 2 wherein said heating chamber includes: a cavity containing said plurality of heating elements, said cavity being disposed beneath said film transporting means.

9. The structure set forth in claim 4 wherein said film transporting means includes: a pair of rollers including a pinch roller disposed adjacent said inlet opening between which such selected lengths of exposed microfilm are engaged and moved onto said roller conveyor means before being exposed to the heat from said heating chamber.

10. An improvement in a developer of heat sensitive image bearing microfilm comprising: a. a heating chamber having inlet and outlet openings formed therein admitting and discharging respectively selected lengths of exposed and developed microfilm, said chamber including a plurality of heating elements disposed generally opposite the emulsion surface of such selected lengths of exposed microfilm; b. film transporting means constructed and arranged within said heating chamber between said inlet and outlet openings and having continuously moving and changing contact areas engaging a substantially emulsionless surface of such selected lengths of microfilm, said transporting means operating at a speed permitting the latent image in such film to be fully developed; c. and a conveyor mechanism communicating with said film transporting means and said outlet opening of said heating chamber having a flat support thereunder conveying such developed film to a collection point, said conveyor mechanism conveying such film in a flat condition until the film emulsion is set and the latent image is fixed therein.

11. The structure set forth in claim 10 wherein said inlet and outlet openings in said heating chamber are substantially in horizontal opposition to each other and said film transporting means includes roller conveyor means constructed and arranged to convey such selected lengths of film in substantially a horizontal manner.

12. The structure set forth in claim 10 wherein said heating chamber maintains a temperature range between 285 and 290 degrees Fahrenheit and said film transporting means moves such selected lengths of microfilm through said heating chamber in substantially 5 - 7 seconds.