CA1040474A - Copy film vacuum carrier with correct placement detector - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Disclosed is a method and apparatus for holding and detecting correct placement of a photosensitive film on a carrier in a photographic reproduction apparatus for imaging the film.
The carrier has an alignment surface against which the film is firmly held when imaged. Vacuum means are provided which are operably connected to the alignment surface for holding the film securely to the alignment surface. Air passageway means operably connected to the vacuum means are provided in the alignment surface, the air passageway means being of a size and in a posi-tion to form a closed vacuum system which permits a high vacuum level only when the film is correctly placed on the carrier.
Vacuum level detecting means operably connected to the vacuum means are provided for detecting the level of the vacuum, and therefore, correct placement of the film on the carrier. The carrier is preferably provided with reciprocating means for moving the carrier to and from a load position outside of the enclosure of the photographic reproduction apparatus and an imaging position within the enclosure. The vacuum detecting means is preferably operably connected to control means which prevent the carrier from moving into imaging position unless the film is correctly placed upon the carrier with the photo-sensitive surface the imaging means within the apparatus, and the control means is also preferably operably connected to the reciprocating means to return the carrier to the load position if the film moves its securely held position against the alignment surface.

Description

` 1040474 The pre~ent invention relates generally to systems for photographically reproducing data on p~otosensitive fiim, and more particularly, to an apparatus and method for holding the film on and determining correct placement of the film on the film carrier during imaging of the film.
Stimulated by the cost incurred in storing the ever-increasing volume of documentary material which is presently being generated, considerable effort has been expended in the aes$gn and development of various electrophotographic and other : io data storage and retrieval sy~tems. Particular emphasis has beon placed on the design of microphotographic systems which may be u~ed to docrease the physical bulk of ~uch stored material~ ¦
without s~criflcing file retrieval and/or copy reproduction capabilitie~. One type of commonly ~mployed apparatu~ for record-ing data on a film for data ~torage is tho indirect type of reproduction app~ratus wherein a document is placed ~ace down on a tran~par-nt platen and a light imago i- reflected from the document ana airected by mirrors through a lens system and onto the film. In th$s typo of system, the film, which i8 preferably a microfiche, must be securely-held on the imaging axis at the pro~er focal longth away from the lens system. Correct place-ment of tho ~ilm $8 a-sured through use of a carrier having an alignment surface which the film is firmly held when imagod.
` 8$nce the ¢arrier i8 usually positionea inside of the enclo~ure of the photographic reproduction apparatu~, it is not convenient-ly available for placement of a film, or microfiche, upon the carrier. This inconvenience i~ elimina~ed by reciprocating`the carrier from the enclosure to a load posit$on and then back into the imaging poqition within the apparatus enclosure after placement of a film upon the carrier.
It is quite important for the operator of the reproduc-__ ~

104~)474 tion apparatus to be able to ~uickly place the film upon the carrierand be assured that it is properly positioned on the carrier. This prob~em is further complicated by the fact that the film has a photosensitive layer only on one surface and that ~urface usually must be positioned on the carrier facing the directed light image.
This necessity is particularly true, where the film is developed within the reproduction apparatus, as is preferably the case with electrophotographic reproduction apparatus. Of course, the film must be in the proper position on the carrier in order for the light image to be directed to the correct location on the film, a problem which is particularly critical when the film is a micro-fiche having a number of small frames to be individually imaged and developed.
In addition to the problem of properly positioning the film on the carrierso that the light inage ispro~ected to the cor~ect location on the film and the photosensitive layer of the film i8 facing the light image, it is important that the film be securely held against the alignment ~urface to assure that the film is the proper distance from the lens. A number of clamping arrangements are available to securely hold the film against the alignment sur-- face, but they not only have ~he disadvantage of increased compli-cation in the carrier design and $nconvenienco to the operator, but as~uro only that the border portions of the film are held securely to the alignment surface, since the clamping arrangements can only be located in the border regions without interfering with imaging of the film.
Another system which can be used to securely hold the film against an alignment surface is use of a vacuum applied through the alignment surface to securely hold the entire film against the alignment surface. While use of the vacuum system solves some of the problems described, one problem which can occur with it is dislo~ation of the film on the carrier while the carrier is in the imaging position. Such a dislocation can occur through temper-

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104~)474 ary loss or reduction of the vacuum, or from some other interferingforce which moves the film on the carrier. It is quite important to the operator to be assured that the film is in the proper po8i-tion on the carrier while he i8 imaging the film. Additionally, it i8 desirable to return the carrier to the load po~ition outside of the apparatus enclosure in the event the film is dislocated from it~ correct placement in order to prevent the film from falling into the interior of the apparatuswhere extrication can be guite difficult.
It is, therefore, an object of the invention to provide an apparatus and method for securely holding a film agaln~t an align-ment ~urface on a carrier upon which the film is imaged in a photo-graphic reproduction apparatus. It i~ a further ob~ect of the inventlon to provide a method and apparatus for detecting whether the film is properly positioned at the correct location on the carrier and whether the photosensltivo layer of the film 18 faclng the lmaglng means. And, lt is a further ob~ect of the inventlon to provide an apparatus and method for preventing the carrier from enterlng or remaining within the apparatus enclosure if the film 1~ lncorrectly placed on the carrier or the film becomes dislocatoa on the carrier through lo~ of vacuum or other disturbing force.
These and other ob~ects are accompllshed by the apparatu~
and method of inv-ntion. The apparatus of the invention i8 comblna-tlon means for holding a photosensitive film on a film carrier ln a photographic reproduction apparatus and for detecting correct placem nt of the film on the carrier. The apparatu~ not only det-cts whether the film is placed at the correct locatlon on tho carrier, but in a preferred form of the invention, detects whether tho photosensitive layer of the film is facing the llght image within the reproduction apparatus. The carrier has an alignment surface against which the film is firmly held when imaged, and vacuum means are operably connected to the alignment surface for holding the film securely against the alignment surface. Air-

-3-" 104V474 passageway means are provided in the alignment surface and are oper-ably connected to the vacuum means for forming a closed vacuum ystem only when the film i5 correctly placed on the carrier.
Vacuum level detecting means are connected to the vacuum means for detecting the level of the vacuum within the ~ystem. If the fllm is corroctly placed on the carrier, the vacuum level detecting means detects a high level of vacuum, and if the film i8 incorroctly placed on the carrier, the vacuum level detecting means detect~ a low level of vacuum, occuring as a result of vaccum leakage throuqh t~e air-passageway means not covered by the film. In the preferrea embodiment of the apparatusJ reciprocating means are providod for ving th- carrier to and from a load position outside of the re-production apparatus enclosure and an imaging position wlthln the nclo~ure, and the vacuum level detecting means is operably con-nect-d to control means for proventing the carrier from enterlng the enclo~ure unless the film is properly placed on the carrier and for roturning the carrier to the load position out~ide of the enclo~ure if th- film becomes dislocated on the carrier.
The apparatus includes means for determining whether the fllm i8 positioned on the carrier with the photosensitive layer faclng the light image. The~e means consist of a pair of film po-itioning pins on the carrier designed for insertion into posi-tioning holes on the film to correctly position the film on the carrier. The positioning holes on the film are asymmetrically located 80 that the film iB placed against the alignment surface in one position when the photosensitive layer is facing the light image, and the film is placed against the alignment surface in another position offset from the first position if the photo-~onsitive layer is facing the alignment surface rather than the light image. The air-passageway means in the alignment surface i8 80 sized and positioned to be completely covered by the film when it is positioned in the correct location on the alignment surface and partially uncovered by the film when the film is positioned in the incorrect location on the carrier.
Fig. 1 is a perspective view of a photographic reproduc-tion apparatus in which the present invention is advantageously employed;
Fig. 2 is a diagrammatic sectional view showing the optical assembly of the apparatus of Fig. 1 and the apparatus of the invention;
Fig. 3 is a front elevational view of the carrier of the invention showing a microfiche inserted thereon;
Fig. 4 is a cross-sectional view of the carriage of Fig. 4 taken along line 4-4.
A photographic reproduction apparatus in which the present invention is employed,is illustrated in Fig. 1 and is ~elf-contained within a housing of generally rectangular con-figuration, indicated generally at 10. The top of the housing 10 is generally flat in construction and is designed to incorpo-rate an operator's console 13, a microfiche access slot 14, and a copyboard 11. The operator's console 13 contains all necessary controls for operating the apparatus to enable the system operator to control the reproduction sequence.
A carriage assembly having a microfiche carrier 12 i8 ; disposed within the enclosure 10 such that the carrier 12 may be tran~ported upwardly through slot 14, to a load position, illus-trated in Fig. 1. In the load position, a microfiche may be easily placed upon the carrier 12 for movement into the enclosure 10. After placement of a microfiche on the carrier 12, the carrier 12 may be transported back to the imaging position, illustrated in Fig. 2.
The pbox~raphic reprol/~icn apparatus is diagra~tically illu~-trated in Fig. 2, where a do~nent i8 p~d upon tran~ent o~board 11, and a light from ~m~ 17 and ref~K~Dr 18 is reflec~ off of the ~x~ment and d~n~ed by minx~ 19, 20, and 21 th~h lens 22 and onbo the desired lr~-ticn ofn~crofiche 15 pL~æd upon carrier 12. The means for reciprocat carrier 12 to and frcm the load po~itionand the imaging position _5_ 104~474 i9 provided by reversible electric motor 28 and screw 29 passing through threaded lug 40 on carrier 12.
Carrier 12, illustrated in Figs. 3 and 4, includes a flat, alignment surface facing the imaging means. The alignment surface has an air-impervious border region 41, provided by such material as plastic, and an inner, air-pervious surface 36, which can be provided by such material as porous ceramic material. On both sides of the carrier 12 are cylindrical sleeves 33 in which guide rods (not shown) are placed to guide the carrier to and from tho load position and the imaging position.
Vacuum means, illustrated as vacuum pump 24 in Fig. 2, communicates with the carrier 12 through conduit 23. Conduit 23 onters the back of the carrier 12 and communicates with the air-pervious surface 36 through cavity 42. The air-impervious border reglon 41 surrounding the air-pervious material 36 ccoperates with conduit 23 to provide a closed vacuum system about the air-pervious matorlsl 36, except for the exposed portion of the air-pervious material 36 forming the alignment ~urface of the carrier 12.
The carxier 12 includes film-positioning pins 34 and 35 for insertion in corresponding positioning holes in the microfiche 15. '~he positioning holes in the microfiche 15 are asymmetrical with respect to the vertical center line of the film 80 that p?acement of the film on the carrier 12 with the correct side of the film against the alignment surface will centrally position the film 15 on the carrier 12, but will place the film off center if the incorrect surface of the film 15 is placed against the alignment surface. The area of the alignment surface which is provided by the air-pervious material 36 issmaller in size than the area of the film lS and 80 positioned that it is entirely covered by the film 15 when the film 15 is placed on the carrier 12 with the proper side facing the alignment surface and the positioning holes over the ,ilm-positionpins 34 and 35. However, if the film is reversed in its placement on the carrier 12, a portion of the 104~)474 air-pervious material 36 is uncovered by the film, and a closed vacuum system is not formed.
Vacuum detecting means, illustrated as vacuum switch 25, which detects whether the vacuum level within the conduit 23 is above or below a predetermined level, is connected to the con-duit 23. Conventional electrical circuitry connects the vacuum switch to control means 26 for operation of the carrier-reciproca-tion motor 28. The electrical means and control means 26 can be provided by any conventional means, such as relays, which will perform the process function described subsequently.
The apparatus in its preferred form also includes a blower 32, which constantly blows air through conduit 31 against tho film 15 held on the carrier 12. The air blown through conduit 31 is helpful in holding the film 15 to the carrier 12 upon relea~e of the vacuum system, whether the release is deliberate for removal of a film 15 or inadvertent while the film is within the enclosure 10. Thi~ function is particularly useful to prevent dropping the film lS into the enclosure 10 where it is difficult to extricate.
The operation of the invention will now be described.
An operator places a microfiche 15 onto the carrier 12 in the load position (Fig. 1) by insertion of the film-positioning pins 34 and 35 through the positioning holes on the film. He then presses control ~utton 27 which activates the vacuum pump 24, applying a vacuum to the film through the air-pervious surface 35. The film 18 securely held against the alignment surface of the carrier 12, and the vacuum, operating as a closed system, reaches a predetermined level which activates vacuum switch 25, permitting actuation of motor 28 and movement of carrier 12 into the copy position (F$g. 2) within the enclosure. If the film is placed on the carrier 12 with the photosensitive layer incorrectly facing the alignment surface rather then the imaging means, the film 15 does not completely cover the air-pervious material 36, and the vacuum level never reaches the predetermined level. Therefore, the vacuum switch 25 is not 104~474 actuated to permit the control means 26 to energize motor 28, and tho carrier 12 remains in the load position outside of the enclo-sure. At the ~ame time, an electrical signal rom the vacuum switch 25 can illuminate a warning lamp which informs the operator that the film 15 is not correctly placed on the carrier 12.
If the film 15 is correctly placed on the carrier 12, and the carrier 12 has been moved into the imaqing position wlthin the enclosure 10, the operator may then proceed with placing document~ upon the copyboard 11, covering the documents with copyboard cover 16 and imaging the film. In the event the film 15 becomes displaced from its correct position on the carrier 12 for any roason, such as temporary 1088 of the vacuum which might re~ult ln the film 15 moving slightly away from the alignment ~urfaae, the vacuum switch 25 will detect the 1088 of vacuum level wlthin the condult 23, and will transmit an electrical signal to th~ control mean~ 26, which will in turn energize motor 28 to move the carrler 12 back to the load position outside of the enclosure 10. Thu~, the operator does not continue imaging the film when lt i- not correctly placed on the carrier or at the correct focal dlstance from the lens 22. ~he film i8 transported to the load po~ition as quickly as possible to avoid dropping the film into th- int~rior of the enclosure.
The air supplied by blower 32 through conduit 31 pushes the film 15 against the carrier 12 with sufficient force tc hold the film to the carrier while the carrier and film are being return-d to the load position. The air from the blower 32 18 al~o u-eful in holding the film 15 to the carrier 12 after deliberate release of the vacuum means when the carrier 12 is in the lo~d position and the operator desires to remove the film 15 from the carrier 12.
While the apparatus and method of the invention have be-n de~cribed in their preferred embodiments, a number of variation~
can be employed within the scope of the invention. For example, 10404~4 the air-pervious material 36 can be provided in some arrangements by a simple open conduit rather than a porous material, although the porous material is very advantageous in forming a flat sur-face against which the film can be held for proper alignment.
Also, forms of positioning means other than pins 34 and 35 and holes in the film can be used, examples being notches in the film and protuberances on the carrier, or vice versa.

Claims (6)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a photographic reproduction apparatus for imaging a photosensitive film positioned on a film carrier within the apparatus, combination means for holding the film on the carrier and detecting correct placement of the film on the carrier, the combination means comprising:
an alignment surface on the carrier against which the film is firmly held when imaged;
vacuum means operably connected to the alignment sur-face for holding the film securely to the alignment surface;
air-passageway means in the alignment surface and oper-ably connected to the vacuum means for forming a closed vacuum system, and permitting a high vacuum level, only when the film is correctly placed on the carrier; and vacuum level detecting means operably connected to the vacuum means for detecting the level of the vacuum, and therefore, correct placement of the film on the carrier.

2. A photographic reproduction apparatus for imaging a film having a photosensitive layer on one surface and first positioning means asymmetrically located on the film, the apparatus comprising A. an enclosure within which the film is imaged;
B. imaging means within the enclosure for exposing the film to a light image;
C. a carrier for holding the film in a predetermined position with respect to the imaging means while the film is being imaged, the carrier comprising, i. second positioning means for engaging the first positioning means on the film to position the film in a correct location on the carrier if the film is placed with the photosensitive layer towards the imaging means and to position the film in an incorrect location on the carrier if the film is placed with the photosensitive layer away from the imaging means, and ii. a flat alignment surface against which the film is firmly held, the alignment surface having an air-impervious border region and an air-pervious inner region, the inner region occupying an area which is completely covered by the film when the film is positioned in the correct location on the carrier and is partially uncovered by the film when the film is positioned in the incorrect loca-tion on the carrier;
D. reciprocating means for moving the carrier to and from a load position outside of the enclosure and an imaging position within the enclosure;
E. vacuum means operably connected to the air-pervious inner region for holding the film securely against the alignment surface, the vacuum means forming a sealed vacuum system when the film is held securely against the alignment surface in the correct loca-tion; and F. vacuum detecting means operably connected to the vacuum means for detecting the vacuum level and thereby detecting when the film is held securely against the alignment surface in the correct location.

3. Apparatus according to claim 2, including control means operably connected to the reciprocating means and the vacuum detect-ing means for moving the carrier to the load position if a drop in vacuum level is detected when the carrier is in the imaging position.

4. Apparatus according to claim 3, wherein the control means prevents movement of the carrier from the load position to the imaging position unless the film is placed at the correct loca-tion on the alignment surface.

5. Apparatus according to claim 4, including means to con-stantly blow air against the film on the carrier.

6. In a photographic reproduction apparatus for imaging a photosensitive film positioned on a film carrier within the apparatus, a method of holding the film on the carrier and detecting correct placement of the film on the carrier comprising the steps of:
applying a vacuum to the film through air-pervious passage-way means in an alignment surface on the carrier to hold the film firmly against the alignment surface, the air-pervious passage-way means being of a size and location to form a closed vacuum system and a high vacuum level only when the film is correctly placed on the carrier; and detecting the presence or absence of the high vacuum level, thereby detecting correct placement of the film on the carrier.