CA1107116A - High speed, low temperature and pressure diazo processing method and apparatus - Google Patents
High speed, low temperature and pressure diazo processing method and apparatusInfo
- Publication number
- CA1107116A CA1107116A CA318,073A CA318073A CA1107116A CA 1107116 A CA1107116 A CA 1107116A CA 318073 A CA318073 A CA 318073A CA 1107116 A CA1107116 A CA 1107116A
- Authority
- CA
- Canada
- Prior art keywords
- film
- chamber
- ammonia
- platens
- ammonia vapor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
- G03C5/18—Diazo-type processes, e.g. thermal development, or agents therefor
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03D—APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS; ACCESSORIES THEREFOR
- G03D7/00—Gas processing apparatus
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
Abstract
HIGH SPEED, LOW TEMPERATURE AND
PRESSURE DIAZO PROCESSING APPARATUS
Abstract of the Disclosure A processor for developing diazo film defined by a pair of flat platens disposed within a housing and spaced apart a distance only slightly greater than the thickness of the film. The housing includes intake and outlet openings aligned with the space between the platens and means for advancing an incoming film from intake opening, through the space between the platens and for discharging it through the outlet opening. The platen facing the emulsion side of the film is heated and includes at least one passage through which a metered amount of aqueous ammonia is passed for each film that is to be developed. The ammonia is vaporized in the passage and discharged against the emulsion side of the film. A transverse groove in the emulsion facing surface of the platen communicates with the passage to distribute the ammonia vapor over the full width of the film. The deve-loping temperature is between about 150-200°F, the ammonia vapor pressure does not substantially exceed atmospheric pressure and developing times axe no more than a few seconds.
PRESSURE DIAZO PROCESSING APPARATUS
Abstract of the Disclosure A processor for developing diazo film defined by a pair of flat platens disposed within a housing and spaced apart a distance only slightly greater than the thickness of the film. The housing includes intake and outlet openings aligned with the space between the platens and means for advancing an incoming film from intake opening, through the space between the platens and for discharging it through the outlet opening. The platen facing the emulsion side of the film is heated and includes at least one passage through which a metered amount of aqueous ammonia is passed for each film that is to be developed. The ammonia is vaporized in the passage and discharged against the emulsion side of the film. A transverse groove in the emulsion facing surface of the platen communicates with the passage to distribute the ammonia vapor over the full width of the film. The deve-loping temperature is between about 150-200°F, the ammonia vapor pressure does not substantially exceed atmospheric pressure and developing times axe no more than a few seconds.
Description
~ ~6 This invention relates to a method and apparatus for developing diazo film.
Dia20 sensitized papers have been used for a long time for making duplicate copies of originals, normally by contact printing, and the subsequent development of the exposed diazo paper in an aqueous ammonia vapor atmosphere.
In such an application, resolution requirements and deve-lopment times are not critical. More recently diazo sen-sitized films have received increasing attention as an ideal medium for making microfilm or microfiche masters and, perhaps more importantly, duplicates thereof because o the relatively low cost of such film, its high resolution capability, etc. For such applications, however, increasingly stringent demands are made on the film developing process, particularly as to the speed with which it can be accom-plished so as to enable an efficient, high volume production of diazo film copies from a master, for example.
In this~regard, problems have been encountered in the~past. Ir~ order to attain short development times for diazo film, it was heretofore thought necessary that the development t~ke place in a high pressure ammonia atmos-phere. In general, the pressures that were considered necessary~are substantially above, e.g. several times, the atmospheric pressure and they ranged up to as high as 1,000 psi or more. For example, U.S. Patent 3,411,906 issued to IBM November l9r 1968, speaks of ammonia pressures in the ;range of between S0 to 1,000 pSl. ~ittle attention was paid to the actual design~of the developing chamber into which - -:: ~ :
the ammonia is introduced other than to maintain the volume relatively small for the obvious expedient o l1miting the amount of ammonia that is expended in the developing process.
From a practical view, however, such high pressure requirements represent severe drawbacks, particularly in connection with a continuously operating diazo film deve-loper since the exposed film must be transported from theexterior into the high pre~sure atmosphere. For one, ammonia leakage is quite unacceptable because o its noxious odor and the potential health hazard it represents if present in appreciable concentrations. Further, it is notoriously difficult to seal a pressurized chamber if contLnuous access to its interior is required unless the ammonia in the chamber is evacuated each time a film is inserted therein or withdrawn therefrom. This, however, is not compatlble with a hlgh speed, high volume operation.
Although the above-referenced U.S. patent does not concern itself with the actual chamber construction and is not concerned with the above summarized difficulties of operating it, another U~S. Patent (No. 3,364,833, issued to IB~ January 23, 1968) proposes the construction of a diazo film deve]op1ng de~ice comprlsing a sealed chamber defined by a hase having a cavity dimensioned to receive the Eilm and a cover that is bolted and sealed against the base. The space of the cavity is kept as small as possib:Le and once it is sealed, the air therein is evacuated and replaced with high pressure ammonia to develop the film. ~lthough this device not doubt assures the ful1 and complete development of the film and, if operated alon~ the lines suggested in the earlier referenced U.S. patent yields short development ~ :
~ times, the insertion and remo~al of the film from the cavity :~ ~
~ 30 must be manually perform0d and sureLy exceeds the develop-:, :
:: : :
, -, ment time for the film by a very large factor. Thus, the device disclosed in U.S. patent 3,364,833 may be ideally suited for developing an individual diazo film from time-to-time; but it is unsuitable for continuous, large volume operations.
Thus, inspite of the advantages afforded by diazo film for high resolution, high volume applications such as for the duplication of microfiche masters, there is pre- -sently no technologically feasible device for economically mass developing such film.
~ .
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The present invention provides a diazo film developing method and apparatus which dramatically departs from prior art concepts for the construction and operation of diazo film developers to render them compact, efficient and easy to operate at even very high film output volumes.
This is accomplished by dispensing with the high ammonia pressures heretoore thought nacessary to achieve short developing times~ Instead, in accordance with the present ~ .
- invention, the film is developed in aqueous ammonia vapor at a pressure which does not substantially exceed atmospheric : pressure. For purposes of the present invention, this means : that the pressure is only slightly higher than atmospheric :
pressure, by an amount no more than that required to in~
troduce the vapor into the developing chamber. Thus, the pressure is typically in the area of no more than a Eew, say 1 to 2 inches of water column above atmospheric pressure and in any event, it is substantially less than the heretofore suggested ammonia pressure and, therefore, will always be less ~han one atmosphere ~about 14 psi) above atmospheric 20:~ preSsure~
Thus, in a first aspect the invention is a method for developing diazo film having a substrate and an emul.si.on carried on a side of the substrate, the method comprising the steps of: placing the ilm i.n a chamber having physical ~chamber dimensions only slightly larger than the physical ~: dimensions of the filmi introducing aqueous ammonia vapor into the chamber at a pressure not substantially greater::
than atmospheric pressure so that the ammonia vapor contacts the film emulsion:~and remo~ing the .ilm from the chamber : `: :
~ 5 ~:
': ::: :
,` : ' ~ . ' ' ' ' '. ~ ' ' ' ' : ': ' after a relatively shor-t time interval of no more than a few seconds.
This low pressure ammonia vapor is combined with a minimal developing chamber volume which is no greater than that required to conveniently pass a film to be developed through the chamber. The low pressure ammonia vapor and small developing chamber volume is further coupled with relatively low operating temperatures in a range of between about 150F to 200F and, preferably, between about 175F to 10 190F so that the emulsion layer on the film is not softened by heat. In this manner, moving contact between the film and in particular its emulsion and components of the chamber will not damage the emulsion. This facilitates the mini-mization of the developing chamber volume since an actual 15 contact between the moving film emulsion and chamber walls does not adversely affect the imayes on the film. In fact, applicants presentLy believe that such a moving contact between the emulsion and chamber walls, at least so long as it takes place intermittently, enhances the development of 20 the~film by more intimately subjecting the emulsi.on to the ammonia vapor and removing from the emulsion any expended ammonia.
In a second aspect, tha invantion is apparatus Eor developing diazo film comprising means defininy a developing 25 chamber~and including first and second, spaced apart, ~;
substantially parallel surfaces, a spacing between the surfaces exceeding a thickness o the film by no more than .
~ an~amount requlred to readily move the Eilm through the ~ ~ :
~ 6~
.
`7~
chamber; means defining an intake opening for introducing the film into the chamber and for removing it therefrom;
means for movlng the film through the opening and into and out of the chamber so -that an emulsion side of the film passes immediately adjacent one of the surfaces; and means for applying relatively low pressure aqueous ammonia vapor into a space between the film emulsion and the one surface;
whereby a rapid, low a~nonia pressure vapor developing of the emulsion is effected.
In a practlcal embodiment such a spacing is normally between about two to about eight times the film thickness, which a spacing of about 0.020" being presently preferred because of the ease with which the component making up the chamber can be manufactured, the ease with 15 which the ~ilm can be transported between the surfaces in actual use, and the relatively very low volume exhibited by a chamber having such dimensions.
Eurther, the pre.sent invention contemplates that the film~is advanced~in a downstream direction through the ~ 20~ :chamber at a speed~:so that the stay time for (any part of) : the film does not subst.antially exceed a ew seconds, say five seconds and, preerably, so that the stay time is no more than about one or two seconds. Aqueous ammonia is introduced into the chamber from the chamber surface which ~ 25 faces the emuls~ion slde oE the film. The ammonia vapor is ;;.
; : of substantially atmospheric pressure, that is it is only slightly, e.g. a few inches o:E water column above atmos-pheri~c pressure.
: The vaporization and (mlnimal) pressurization of ;~ 30 the ammonia is achleve~:by provid.ing a heating platen which :
~ 7 :: :
: , .
defines the surface that faces the emulsion side of the film and forming an open conduit therein which extends through the film facing surface of the platen. The platen is heated to the above-stated developing temperature and aqueous ammonia is flowed into the conduit where it is vaporized due to the ele~ated temperature~ This results in the above-discussed slight rise in the ammonia vapor pressure of a few inches of water column so that the vapor discharges from the conduit into the chamber. In a preferred embodiment of the invention~ a metered amount of aqueous ammonia is pumped into the conduit for each film to be developed. This can be done by using an appropriately designed pump or by sensing an approaching ~ilm and intermittently actuating a metered aqueous ammonia pump in response thereto.
In a preferred embodiment the apparatus of the present invention, generally speaking, comprises a housing that defines an upstream film intake opening and a down-stream film outlet opening~ E`irst and second platens are disposed within the housing and opposing, parallel first and second surfaces of the platens are positioned to receive incoming film from the intake opening and to discharge outgoing film to the outlet opening~ Means is further provided Eor maintaining the spacing between the platens in the above-outlirle~ range so as to permit the uninhibited passage of the film between the surfaces while minimizing the spacing between the surfaces and, therefore, the volume of the developing chamber defined by the space , ::
' ;
7a ~ .
: ~
:
~ .
~ 11~7116 1¦ between the platens. Pairs of c~operating rollers advance
Dia20 sensitized papers have been used for a long time for making duplicate copies of originals, normally by contact printing, and the subsequent development of the exposed diazo paper in an aqueous ammonia vapor atmosphere.
In such an application, resolution requirements and deve-lopment times are not critical. More recently diazo sen-sitized films have received increasing attention as an ideal medium for making microfilm or microfiche masters and, perhaps more importantly, duplicates thereof because o the relatively low cost of such film, its high resolution capability, etc. For such applications, however, increasingly stringent demands are made on the film developing process, particularly as to the speed with which it can be accom-plished so as to enable an efficient, high volume production of diazo film copies from a master, for example.
In this~regard, problems have been encountered in the~past. Ir~ order to attain short development times for diazo film, it was heretofore thought necessary that the development t~ke place in a high pressure ammonia atmos-phere. In general, the pressures that were considered necessary~are substantially above, e.g. several times, the atmospheric pressure and they ranged up to as high as 1,000 psi or more. For example, U.S. Patent 3,411,906 issued to IBM November l9r 1968, speaks of ammonia pressures in the ;range of between S0 to 1,000 pSl. ~ittle attention was paid to the actual design~of the developing chamber into which - -:: ~ :
the ammonia is introduced other than to maintain the volume relatively small for the obvious expedient o l1miting the amount of ammonia that is expended in the developing process.
From a practical view, however, such high pressure requirements represent severe drawbacks, particularly in connection with a continuously operating diazo film deve-loper since the exposed film must be transported from theexterior into the high pre~sure atmosphere. For one, ammonia leakage is quite unacceptable because o its noxious odor and the potential health hazard it represents if present in appreciable concentrations. Further, it is notoriously difficult to seal a pressurized chamber if contLnuous access to its interior is required unless the ammonia in the chamber is evacuated each time a film is inserted therein or withdrawn therefrom. This, however, is not compatlble with a hlgh speed, high volume operation.
Although the above-referenced U.S. patent does not concern itself with the actual chamber construction and is not concerned with the above summarized difficulties of operating it, another U~S. Patent (No. 3,364,833, issued to IB~ January 23, 1968) proposes the construction of a diazo film deve]op1ng de~ice comprlsing a sealed chamber defined by a hase having a cavity dimensioned to receive the Eilm and a cover that is bolted and sealed against the base. The space of the cavity is kept as small as possib:Le and once it is sealed, the air therein is evacuated and replaced with high pressure ammonia to develop the film. ~lthough this device not doubt assures the ful1 and complete development of the film and, if operated alon~ the lines suggested in the earlier referenced U.S. patent yields short development ~ :
~ times, the insertion and remo~al of the film from the cavity :~ ~
~ 30 must be manually perform0d and sureLy exceeds the develop-:, :
:: : :
, -, ment time for the film by a very large factor. Thus, the device disclosed in U.S. patent 3,364,833 may be ideally suited for developing an individual diazo film from time-to-time; but it is unsuitable for continuous, large volume operations.
Thus, inspite of the advantages afforded by diazo film for high resolution, high volume applications such as for the duplication of microfiche masters, there is pre- -sently no technologically feasible device for economically mass developing such film.
~ .
.
' .
: :
: ~ ' :
:: :
. ~ : :
The present invention provides a diazo film developing method and apparatus which dramatically departs from prior art concepts for the construction and operation of diazo film developers to render them compact, efficient and easy to operate at even very high film output volumes.
This is accomplished by dispensing with the high ammonia pressures heretoore thought nacessary to achieve short developing times~ Instead, in accordance with the present ~ .
- invention, the film is developed in aqueous ammonia vapor at a pressure which does not substantially exceed atmospheric : pressure. For purposes of the present invention, this means : that the pressure is only slightly higher than atmospheric :
pressure, by an amount no more than that required to in~
troduce the vapor into the developing chamber. Thus, the pressure is typically in the area of no more than a Eew, say 1 to 2 inches of water column above atmospheric pressure and in any event, it is substantially less than the heretofore suggested ammonia pressure and, therefore, will always be less ~han one atmosphere ~about 14 psi) above atmospheric 20:~ preSsure~
Thus, in a first aspect the invention is a method for developing diazo film having a substrate and an emul.si.on carried on a side of the substrate, the method comprising the steps of: placing the ilm i.n a chamber having physical ~chamber dimensions only slightly larger than the physical ~: dimensions of the filmi introducing aqueous ammonia vapor into the chamber at a pressure not substantially greater::
than atmospheric pressure so that the ammonia vapor contacts the film emulsion:~and remo~ing the .ilm from the chamber : `: :
~ 5 ~:
': ::: :
,` : ' ~ . ' ' ' ' '. ~ ' ' ' ' : ': ' after a relatively shor-t time interval of no more than a few seconds.
This low pressure ammonia vapor is combined with a minimal developing chamber volume which is no greater than that required to conveniently pass a film to be developed through the chamber. The low pressure ammonia vapor and small developing chamber volume is further coupled with relatively low operating temperatures in a range of between about 150F to 200F and, preferably, between about 175F to 10 190F so that the emulsion layer on the film is not softened by heat. In this manner, moving contact between the film and in particular its emulsion and components of the chamber will not damage the emulsion. This facilitates the mini-mization of the developing chamber volume since an actual 15 contact between the moving film emulsion and chamber walls does not adversely affect the imayes on the film. In fact, applicants presentLy believe that such a moving contact between the emulsion and chamber walls, at least so long as it takes place intermittently, enhances the development of 20 the~film by more intimately subjecting the emulsi.on to the ammonia vapor and removing from the emulsion any expended ammonia.
In a second aspect, tha invantion is apparatus Eor developing diazo film comprising means defininy a developing 25 chamber~and including first and second, spaced apart, ~;
substantially parallel surfaces, a spacing between the surfaces exceeding a thickness o the film by no more than .
~ an~amount requlred to readily move the Eilm through the ~ ~ :
~ 6~
.
`7~
chamber; means defining an intake opening for introducing the film into the chamber and for removing it therefrom;
means for movlng the film through the opening and into and out of the chamber so -that an emulsion side of the film passes immediately adjacent one of the surfaces; and means for applying relatively low pressure aqueous ammonia vapor into a space between the film emulsion and the one surface;
whereby a rapid, low a~nonia pressure vapor developing of the emulsion is effected.
In a practlcal embodiment such a spacing is normally between about two to about eight times the film thickness, which a spacing of about 0.020" being presently preferred because of the ease with which the component making up the chamber can be manufactured, the ease with 15 which the ~ilm can be transported between the surfaces in actual use, and the relatively very low volume exhibited by a chamber having such dimensions.
Eurther, the pre.sent invention contemplates that the film~is advanced~in a downstream direction through the ~ 20~ :chamber at a speed~:so that the stay time for (any part of) : the film does not subst.antially exceed a ew seconds, say five seconds and, preerably, so that the stay time is no more than about one or two seconds. Aqueous ammonia is introduced into the chamber from the chamber surface which ~ 25 faces the emuls~ion slde oE the film. The ammonia vapor is ;;.
; : of substantially atmospheric pressure, that is it is only slightly, e.g. a few inches o:E water column above atmos-pheri~c pressure.
: The vaporization and (mlnimal) pressurization of ;~ 30 the ammonia is achleve~:by provid.ing a heating platen which :
~ 7 :: :
: , .
defines the surface that faces the emulsion side of the film and forming an open conduit therein which extends through the film facing surface of the platen. The platen is heated to the above-stated developing temperature and aqueous ammonia is flowed into the conduit where it is vaporized due to the ele~ated temperature~ This results in the above-discussed slight rise in the ammonia vapor pressure of a few inches of water column so that the vapor discharges from the conduit into the chamber. In a preferred embodiment of the invention~ a metered amount of aqueous ammonia is pumped into the conduit for each film to be developed. This can be done by using an appropriately designed pump or by sensing an approaching ~ilm and intermittently actuating a metered aqueous ammonia pump in response thereto.
In a preferred embodiment the apparatus of the present invention, generally speaking, comprises a housing that defines an upstream film intake opening and a down-stream film outlet opening~ E`irst and second platens are disposed within the housing and opposing, parallel first and second surfaces of the platens are positioned to receive incoming film from the intake opening and to discharge outgoing film to the outlet opening~ Means is further provided Eor maintaining the spacing between the platens in the above-outlirle~ range so as to permit the uninhibited passage of the film between the surfaces while minimizing the spacing between the surfaces and, therefore, the volume of the developing chamber defined by the space , ::
' ;
7a ~ .
: ~
:
~ .
~ 11~7116 1¦ between the platens. Pairs of c~operating rollers advance
2 the film (with its emulsion side facing the first surface)
3 in a downstream direction from the~intake opening through
4 the chamber to the outlet opening.
5¦ The present invention further provides means for ¦ sealing the developing chamber from the intake and the 71 outlet openings. ~he sealing means comprise sets of cooperating, 8l elongate, opposite rollers disposed adjacent and parallel to 9 the openings for receiving and discharging the film. The rollers have resilient surfaces in mutual contact and low 11 ~riction, e.g. Teflon (a registered Trademark of the Dupont 12 de Nemours Company) strips are sealingly disposed in correspondin 13¦ grooves of the housing, are arranged parallel to the rollers, 14 ¦ and are resiliently biased thereagainst so as to form a seal 15l therewith and prevent the escape o ammonia vapors through 16 the openings to the exterior. Although such a seal would 17 not be sufficient to withstand the hiqh ammonia pressures 18 found in prior art diazo film developing systems, it is 19~ ~ suflicient to form a seal during the low pressure operation of the apparatus Oe the present invention so that no noxious 21 ammonia odors escape. Consequently, a device constructed in 22 accordance with the invention can be operated in closed 23 rooms with little or no separate ventilation without representing 241 a health ha~ard or creatlng an objec*ionable stench or odor.
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~7~16 1 Alternatively, the spring biased strips which 2 engage the resilient roller surfaces may be replaced with 3 relatively flexible Teflon sheets ~hich extend over the 4 length of each roller. One portion of the sheet is rigidly 3 secured, e.g. bolted against a platen while the other portion
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~2 31 ~ ~
32 ~ 8-, ;
. ~ ~ ~
.___~ ..
~7~16 1 Alternatively, the spring biased strips which 2 engage the resilient roller surfaces may be replaced with 3 relatively flexible Teflon sheets ~hich extend over the 4 length of each roller. One portion of the sheet is rigidly 3 secured, e.g. bolted against a platen while the other portion
6 of the sheet overlies the respective roller. A flexible
7 leaf-spring is similarly bolted against the platens, preferably together with the Teflon sheet, and it is arranged so as to 3 bias the associated sheet against the roller surface to thereby establish a seal between the developing chamber and 11 the exterior.
12 Further, the apparatus of the present invention 13¦ includes a heater for heating the first platen to a temperature 14 1 in the above-stated range and at least one conduit is formed 15¦ in the first platen, communicates with the ~irst surface and 161 is located pro~imate the upstream end thereof. Pump means 17¦ supplies to the conduit aqueous ammonia and means is provided 18¦ for evaporating the ammonia therein to effect a discharge of 1~¦ the ammonia vapor from the conduit at the above-discussed ZO I
~4 ::
30~ ;
32~
-8a-_ 11~7~16 ~¦ low pressure. Thus, as the diazo film advances through the 21 developing chamber, it is contacted by the ammonia vapor and 31 causes the formation of a turbulent ammonia vapor layer 4l between at least portions of the emulsion and the first ~ surface to effect the rapid developing of the emulsion at 6 low temperatures and pressures.
7 ¦ The first surface preferably includes a transverse
12 Further, the apparatus of the present invention 13¦ includes a heater for heating the first platen to a temperature 14 1 in the above-stated range and at least one conduit is formed 15¦ in the first platen, communicates with the ~irst surface and 161 is located pro~imate the upstream end thereof. Pump means 17¦ supplies to the conduit aqueous ammonia and means is provided 18¦ for evaporating the ammonia therein to effect a discharge of 1~¦ the ammonia vapor from the conduit at the above-discussed ZO I
~4 ::
30~ ;
32~
-8a-_ 11~7~16 ~¦ low pressure. Thus, as the diazo film advances through the 21 developing chamber, it is contacted by the ammonia vapor and 31 causes the formation of a turbulent ammonia vapor layer 4l between at least portions of the emulsion and the first ~ surface to effect the rapid developing of the emulsion at 6 low temperatures and pressures.
7 ¦ The first surface preferably includes a transverse
8 groove which fluidly communicates with the ammonia conduit
9¦ to effect the distribution of the vapor over the full film
10¦ width. Additional grooves downstream of the first mentioned
11 1 groove enhance the developing speed believed to be at least
12 ¦ in part caused by the increased turbulence in the ammonia
13 ¦ vapor which is caused by such grooves.
14 ¦ To further enhance the developing process the film
15 ¦ itself is preferably preheated before. it enters the developing
16 ¦ chamber. In a preferred e~bodiment of the invention, this
17 ¦ is accomplished by passing the film between two platens
18 ¦ heated to the same tempexature as the first platens, and
19 ¦ disposed upstream of the developing chamber.
20 ¦ From the foregoing summary, it is apparent that
21 ¦ the present invention achleves the high speed developins of
22 ¦ diazo-~ype fllm without having to xely on the high pressures
23 I required in prior art diazo developing systems. This,
24 coupled with the small chamber dimensions enables the very
25 ¦ rapid development of microfiche, ofte.n in less than one
26 ¦ second. It~conserves ammonia and, most importantly, it ~7 I ' , 29 1 ~
3~ 1~ ~ , 31 ~: ~
,:~ I
,. 1~ -9-I'~ ~
, .
l enables a very simple construction of the chamber and the film transport mechanism while assuring an effective seal to 3 prevent the escape of ammonia into ~the surrounding atmosphere.
4 Therefore, the present invention is ideally suited for g incorporatlon in microfiche duplicators and its wide acceptance 6 ¦ hroughout the industry is fully enticipated.
3~ 1~ ~ , 31 ~: ~
,:~ I
,. 1~ -9-I'~ ~
, .
l enables a very simple construction of the chamber and the film transport mechanism while assuring an effective seal to 3 prevent the escape of ammonia into ~the surrounding atmosphere.
4 Therefore, the present invention is ideally suited for g incorporatlon in microfiche duplicators and its wide acceptance 6 ¦ hroughout the industry is fully enticipated.
27
28 3~ :
32 ~ .
10- l Aspects of -the invention are illustrated, merely by way of example in the drawings.
In these drawings:-Figure 1 is an overall side elevational view, in section, oE a diazo film developer constructed in accordancewith the present invention for incorporation in a microfiche copier or the like;
Figure 2 is a front elevational view, in section, of the developer shown in Figure 1 and is taken on line 2-2 of Figure l;
Figure 3 is an enlarged~ schematic side eleva-tional view of the developing chamber shown in Figure l;
Figure 4 is a schematic plan view of the platen defining the side of the chamber shown in Figure 3 which faces the emulsion side of the film;
Figure 5 is a fragmentary, side elevational view, : similar to Figure l and shows another embodiment of the present invention; and ~ Figure 6 is a fragmentary front elevational view : ~ 20 illustratlng the manner in which the developing chamber formed between the platens is sealed in a longitudinal :: direction.
.
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3 Referring to the drawings, a diazo film developer 4 2 may comprise part of a mi~rofiche duplicator 4 (schematically ~ shown only) which includes suitable means for exposing such 6 film and for thereafter advancing it towards the developer. The 7 developer itself generally comprises a housin~ 6 which has upright 8 side walls 8 and spaced apart end walls 10 and which is 91 normally hori~ontally positioned. The end walls 10 dein~
~1 an upstream intake opening 12 through which a microfiche 14 11 ¦ may en~er the interior of the housing. The other, opposite 12 ¦ end wall of the housing defines an outlet opening 16 which 13 ¦ is aligned with the in~ake opening. A flat cover 18 is 14 ¦ placed over the housing an~ a gasket 20 seals the interior ~ ¦ space from the exterior. Suitable closure hinges 22 retain 16 ¦ the cover to the housing while they assure the formation of 17 ¦ a seal between the cover and the gasket.
18 ¦ In the presently preferred embodiment of ~he 19 I lnvention~the housing interior is divided into a pair of 20~ ¦ serlally arranged upstream and downstream cavities 24, 26 by 21 ~a first pair of cylindrical, parallel drive rollers 28 22l positioned at a~out the center of the housing interior. A
231 second and a third pair 30, 32 of like drive rollers is 24¦ disposed adjacent the intake and the oulet openings, respectively 251 The rollers are~in mutual contact along a line aligned with ~61 the center o~ the intake and the outlet openings, they are ~i¦ constructed of a resilient material and they are biased 28¦ against each other so that the rollers form an airtight seal 291 between them.
1 ~ ::
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1~
1 A groove 34 in the housing is adjacent and parallel Z to each roller of the second and third roller pairs. Each 3 such groove receives an elongated low friction, e.g. Teflon 4 strip 36 which is biased against the periphery of the adjacent 5 ¦ roller by a xesiliently compressible member 38 such as a 6 ¦ foam rubber pad. The sealing engagement of the rollers 7 themselves and their sealing engage~en~ of the low friction 8 strips 36, seals ~he housing interior from the intake and q ¦ outlet openings 12, 16. The rollers are further journaled 10¦ in bearings (not shown) carried by the housing side walls 8 11 ¦ which form a seal against the end faces of the rollers. A
121 drive, such as a chain-or sprocket drive (not shown) rotates 13 ¦ the rollers of each pair in opposite direction.s so that a 14 ¦ micrvfiche 14 placed between the upstream, second roller 15 ¦ pair 30 is grasped and advanced in a downstream direetion 16 ¦ into the first, upstream housing cavity 24. Roller pair 28, 17 ¦ which may~be sealed against the housing and the cover in the 18 ¦ above descrlbed manner with suitably placed seal strips 40, 19 ¦ thereafter grasps the downstream moving fiche and advances 20 ¦ it towards the third roller pair which discharges such film 21 ¦ through outlet opening 16 into a receptacle 4~. It will be 22 ¦ noted that during this transport of the film the housing 23 ¦ i~terlox remains fully sealed irrespective o~ ~he speed 24 ¦ and~or frequency ~ith which fiche is fed through the developer.
25 ¦ In the prese~tly preferred embodiment of the 26 ¦ ~lnvantion the upstream cavity 24 is utilized for the preheating 27 ¦ or microfiche 14 before it is developed in the d~wnstream 28 cavity 26.~;~For this purpose, a pair of parallel, opposing upper and lower heating platens 44, 46, respective}y are placed in the ups~ream ~avity. The lower platen rests in a 31 ~ rectangular~grOove 48 on ~a raised frame 53 projectins from a 3~1 bottom plate 50 of the housing and spaces the platen therefrom l ~13-1107il6 1 so that a plate heater 52 can be attached to the underside 2 I of the platen for heating it to the desired temperature as 3 ¦ is further discussed below. Edges 54 ~shown in Fig. 2 only) 4 of the platens overlap, are raised and provided with inter-engaging grooves to maintain the platen in mutual alignment 6 and at the desired spacing so that oppos;ng platen surfaces 71 56, 58 are spaced apart a sufficient distance to permit the 8 ¦ passage of a microfiche therebetween. In a typical embodiment, 9 ¦ the spacin~ is approximately 0.02". Grooves 60 may be I0 ¦ formed in the platen to pxevent the adherence of the film to 11 ¦ one or the other. Further, the edges are spaced apart so that 12 the effective width of the opposing platen surfaces 44, 46 is 13¦ just slightly larger than the width of the fiche 14.
14 ¦ A pair of generally Z-shaped leaf-springs is 15 ¦ mounted, e.g. welded or bolted to the underside of cover 18 16 ¦ and, when the cover is secured to the housing, exerts a 17 ¦ downward pressure against the upper platen 4~ so as to 18 ¦ maintain it in firm contact with the lower platen~
19 ¦ A second pair of developing platens G4, 66 is ~0 ¦ disposed in the downstream cavity 26. The construction of 21 ¦ the developing platens is generally similar to that of ~2 ¦ heating platens 44, 46. Thus, the lower platen rests in an 23 ¦ other rectangular groove 48 formed in a raised frame 53 so 24 I as to provide space for a heater 6~ attached to the underside 25 ¦ of the lower plate. The opposing surfaces 70, 7?. of the 26 I~developing plat~ens define between them a ~e~eloping chamber 85.
27 I Their spacing "T" is closely controlled and in the presently 28 preferred embodiment is 0.02" for accommodating microfiche
32 ~ .
10- l Aspects of -the invention are illustrated, merely by way of example in the drawings.
In these drawings:-Figure 1 is an overall side elevational view, in section, oE a diazo film developer constructed in accordancewith the present invention for incorporation in a microfiche copier or the like;
Figure 2 is a front elevational view, in section, of the developer shown in Figure 1 and is taken on line 2-2 of Figure l;
Figure 3 is an enlarged~ schematic side eleva-tional view of the developing chamber shown in Figure l;
Figure 4 is a schematic plan view of the platen defining the side of the chamber shown in Figure 3 which faces the emulsion side of the film;
Figure 5 is a fragmentary, side elevational view, : similar to Figure l and shows another embodiment of the present invention; and ~ Figure 6 is a fragmentary front elevational view : ~ 20 illustratlng the manner in which the developing chamber formed between the platens is sealed in a longitudinal :: direction.
.
:~:
3 Referring to the drawings, a diazo film developer 4 2 may comprise part of a mi~rofiche duplicator 4 (schematically ~ shown only) which includes suitable means for exposing such 6 film and for thereafter advancing it towards the developer. The 7 developer itself generally comprises a housin~ 6 which has upright 8 side walls 8 and spaced apart end walls 10 and which is 91 normally hori~ontally positioned. The end walls 10 dein~
~1 an upstream intake opening 12 through which a microfiche 14 11 ¦ may en~er the interior of the housing. The other, opposite 12 ¦ end wall of the housing defines an outlet opening 16 which 13 ¦ is aligned with the in~ake opening. A flat cover 18 is 14 ¦ placed over the housing an~ a gasket 20 seals the interior ~ ¦ space from the exterior. Suitable closure hinges 22 retain 16 ¦ the cover to the housing while they assure the formation of 17 ¦ a seal between the cover and the gasket.
18 ¦ In the presently preferred embodiment of ~he 19 I lnvention~the housing interior is divided into a pair of 20~ ¦ serlally arranged upstream and downstream cavities 24, 26 by 21 ~a first pair of cylindrical, parallel drive rollers 28 22l positioned at a~out the center of the housing interior. A
231 second and a third pair 30, 32 of like drive rollers is 24¦ disposed adjacent the intake and the oulet openings, respectively 251 The rollers are~in mutual contact along a line aligned with ~61 the center o~ the intake and the outlet openings, they are ~i¦ constructed of a resilient material and they are biased 28¦ against each other so that the rollers form an airtight seal 291 between them.
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1 A groove 34 in the housing is adjacent and parallel Z to each roller of the second and third roller pairs. Each 3 such groove receives an elongated low friction, e.g. Teflon 4 strip 36 which is biased against the periphery of the adjacent 5 ¦ roller by a xesiliently compressible member 38 such as a 6 ¦ foam rubber pad. The sealing engagement of the rollers 7 themselves and their sealing engage~en~ of the low friction 8 strips 36, seals ~he housing interior from the intake and q ¦ outlet openings 12, 16. The rollers are further journaled 10¦ in bearings (not shown) carried by the housing side walls 8 11 ¦ which form a seal against the end faces of the rollers. A
121 drive, such as a chain-or sprocket drive (not shown) rotates 13 ¦ the rollers of each pair in opposite direction.s so that a 14 ¦ micrvfiche 14 placed between the upstream, second roller 15 ¦ pair 30 is grasped and advanced in a downstream direetion 16 ¦ into the first, upstream housing cavity 24. Roller pair 28, 17 ¦ which may~be sealed against the housing and the cover in the 18 ¦ above descrlbed manner with suitably placed seal strips 40, 19 ¦ thereafter grasps the downstream moving fiche and advances 20 ¦ it towards the third roller pair which discharges such film 21 ¦ through outlet opening 16 into a receptacle 4~. It will be 22 ¦ noted that during this transport of the film the housing 23 ¦ i~terlox remains fully sealed irrespective o~ ~he speed 24 ¦ and~or frequency ~ith which fiche is fed through the developer.
25 ¦ In the prese~tly preferred embodiment of the 26 ¦ ~lnvantion the upstream cavity 24 is utilized for the preheating 27 ¦ or microfiche 14 before it is developed in the d~wnstream 28 cavity 26.~;~For this purpose, a pair of parallel, opposing upper and lower heating platens 44, 46, respective}y are placed in the ups~ream ~avity. The lower platen rests in a 31 ~ rectangular~grOove 48 on ~a raised frame 53 projectins from a 3~1 bottom plate 50 of the housing and spaces the platen therefrom l ~13-1107il6 1 so that a plate heater 52 can be attached to the underside 2 I of the platen for heating it to the desired temperature as 3 ¦ is further discussed below. Edges 54 ~shown in Fig. 2 only) 4 of the platens overlap, are raised and provided with inter-engaging grooves to maintain the platen in mutual alignment 6 and at the desired spacing so that oppos;ng platen surfaces 71 56, 58 are spaced apart a sufficient distance to permit the 8 ¦ passage of a microfiche therebetween. In a typical embodiment, 9 ¦ the spacin~ is approximately 0.02". Grooves 60 may be I0 ¦ formed in the platen to pxevent the adherence of the film to 11 ¦ one or the other. Further, the edges are spaced apart so that 12 the effective width of the opposing platen surfaces 44, 46 is 13¦ just slightly larger than the width of the fiche 14.
14 ¦ A pair of generally Z-shaped leaf-springs is 15 ¦ mounted, e.g. welded or bolted to the underside of cover 18 16 ¦ and, when the cover is secured to the housing, exerts a 17 ¦ downward pressure against the upper platen 4~ so as to 18 ¦ maintain it in firm contact with the lower platen~
19 ¦ A second pair of developing platens G4, 66 is ~0 ¦ disposed in the downstream cavity 26. The construction of 21 ¦ the developing platens is generally similar to that of ~2 ¦ heating platens 44, 46. Thus, the lower platen rests in an 23 ¦ other rectangular groove 48 formed in a raised frame 53 so 24 I as to provide space for a heater 6~ attached to the underside 25 ¦ of the lower plate. The opposing surfaces 70, 7?. of the 26 I~developing plat~ens define between them a ~e~eloping chamber 85.
27 I Their spacing "T" is closely controlled and in the presently 28 preferred embodiment is 0.02" for accommodating microfiche
29 ~ 14 having a thickness "t" o between 0.003 to about 0.007 At the indicated dimensions microfiche is readily transported in a downstream direction, to the left .. ~... . , . I
~ lS
1 as viewed in Figs. 1 and ~, without undesirable interference .
2 from the opposinq platen surfaces.
3 The lower platen includes a first groove 74 adjacen~
4 the upstream end of the platen which extends over the full effective width of the platen and which ls convexly curved 6 when viewed in a downstream direction, that is downwardly as 7 seen in Fig. 4. Additional, similarly shaped gxooves 76 are 8 disposed in the lower platen and arranged downstream of ~ groove 74. An open conduit 78 is formed in the lower platen 10¦ 66 and terminates at about the bottom center of groove 74.
11 ~ Thus, it is also located adjacent the upstream end of the 121 lower platen. The conduit is connected with an aqueous 13¦ aI~monia reservoir 80 via a metering pump 82 and a valve 84 ~4¦ 50 that upon the actuation of the pump aqueous ammonia i5 15¦ flowed into the conduit. The earlier mentioned Z-shaped 16¦ leaf-sprinqs 62 are employed to bias the upper developing 17 ¦ plate 64 downwardly against the lower plate when cover 18 is 18 ¦ closed.
19 ¦ Turning now to the operation of the developer 2, Z0 ¦ heater control 86 is initially actuated to energize heater 21 ¦ 52 of the lower preheating plate 46 and heater 68 o~ the 22 ¦ lower developing platen 66. In this connection, it should ~3 ¦ also be noted that a heater may also be applied to the upper 24 ¦ platen.s 44 and 64 although under normal operations of the developer that i5 not necessary. T~e heater control maintains 26 the platen temperature w.ithin the desired ranqe, e.g. between 2~ 150F to 200F andj preferably in the vicinity of 175F to 8 ¦ 190~F.
29 I ;~
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11071~6 ' ~
1 Metering pump 82 may be selected so that it pumps 2 a ~ery low volume of aqueous ~nonia which is selected to 3 provide just enought ammonia to deuelop the fiches at whatever 4 rate they pass through the developing chamber. Alternatively, ~I the met~ring pump may be an inte~mittently operating pump 61 which is selectively activated in response to an approachi~g 7 ¦ microfiche 14. For that purpose the microfiche duplicator 8 ¦ 4 includes a sensor 88 (such as an optical sensor, for example~ which is operatively coupled with the pump and 101 activates the pump each time a microfiche approaches housing 11 ¦ intake 12, for example, to flow a metered amount of aqueous 1~¦ ammonia to conduit 78. In an alternative operational mode 13j the sensor 88 may be coupled ~lth the valve 84 downstre~m of 14 ¦ pump 82 to temporarily open ~he valve to flow the desired 15 ¦ amount of ammonia to the conduit.
16 ¦ The conduit has a configuration so that ammonia is 17 ¦ heated to about the temperature of the platen while in the 18 ¦ conduit~ This results in the evaporation of the ammonia 19 ¦ therein and the above-discussed slight pressure build up so 20 ¦ that ammonia vapor escapes from the end of conduit 78 which ~1 ¦ terminates in the upstreammost groove 74. When the platen 22 ¦ is operated at the stated temperature range and the conduit 23~ has a diameter of 1/16ths inch, a conduit length within the 2~ platen of 2-1/2 to 3 inches is sufficient to effect the 25¦ desired evaporation of the ammonia.
26¦ The drive ~not separately shown) for roller pairs 27¦ 28, 30 and 32 may be continuously or intermittently operated, 28¦ in the latter case it i5 suitably coupled with sensor 88.
29 1 ~
~; I -16-1 A microfiche 14 ~o be developed which approaches 2 intake opening 12 triggers sensor 88 and causes a meterPd 3 amount of aqueous ammonia to be flowed to conduit 78 where 4 it evaporates and escapes into the developing chamber for 5 the film. Since there is a necessary lag between the introductio 6 of aqueous ammonia to the conduit and i~s evapora~ion the 71 pump is operated a short time period before the fiche arrives at the chamber.
9¦ Once the leading edge of the fiche is grasped by ~o¦ roller pair 30 the fiche is driven in a downstream direction 11 ¦ through the space between the heating platens with its 12l emulsion side 30 facing downwardly, that is oriented so that 13 ¦ it faces the lower, heated platen 46. $he fiche, and in t4 ~ particular, the emulsion carried thereon is heated to about 15 ¦ the temperature prevailing in the de~eloping chamber. After 16 ¦ its leadlng edge issues from the downstream end of the 17 ¦ heating platen roller pair 28- advances it into and through 1B ¦ developing chamber 85.
19 ¦ Since the developing chamber has a height which is 20 ¦ only slightly greater than the thickness o the fiche the 21 ¦ downstream movemenk of the latter causes a great deal of 2Z ¦ turhulence in the alNmonia vapor escaping from conduit 78 23 ¦~ against the emulsion side of the film. Frequently, the 24 ¦ emulsion side will either contact portions oE the opposing 25 ¦ platen surface 72 ox pass closely adjacent to them to 26 ¦ furthex increase the turbulence of the ammonia vapor.
27 Additionally, as it moves over the sur~ace and the grooves 2B therein, the ammonia vapor therebetween retains its turbulence.
~9 It is believ d that this ac~ion provides repeated access for fresh ammonia vapor to the film emulsion and significantly 31 ~
32 ~ 17-~: .. _ .
i.- .
1l contributes to its the high speed development. The fully 2 developed film is then discharged from the developer into 3 receptacle 42.
4 For the above-outlined developing parameters, it 5 has been found that developing times of as little as one 6 second, or in some instances, even less than that, can be 71 achieved so that the film can be moved through the developer 8! at relatively high speeds~
gl This is achieved with a very low pressure ammonia vapor which is readily sealed so that practically no am~onia 11 odors are noticeable even in close proximity to the developer.
12 To remove ammonia condensate from the housing 13 interior a drainage opening 94 is preferably provided beneath 14 developing plate 66 which is connected with a condensate receptacle 96 via a hose 98 or the like. It should further 16 be observed that by placing the Z-shaped leaL-springs 62 17 over the gap between the respecti~e ends of the developing 1~ plates and the adjacent roller pairs 28, 30 any ammonia condensation which may form on the underside of cover 18 is 201 guided along ~he spring onto the top developing plate, from 21 1 where its flow may be guided towards drain 94 via the sides 22¦ of the platens to pre~ent ammonia droplets from contacting 23 ¦ the film. F'urther, to evacuate all ammonia vapors from the 24 ¦ housiny interior preparatory to opening cover 18, an air 25 I blower lO0 is provided to force air into the interior and to 26 thereby correspondingly force the ammonla vapors through the 2-~¦ drainage opening 94 into condensate receptacle 96 where it 281 can be absorbed in a suitab1e liquid, e.g. water bath.
~"~':
~7~6 1 ¦ Referring to Figs. 5 and 6, in an alternative 21 ~mhodiment of the inventionl a developer 102 again comprises 31 a pair of opposite upper and lower platens 104, 106 which are spaced apart as above-described, e.g. 0.20" so as to ~¦ form a gap 108 through which the film passes as it is being 6 ¦ developed~ The lower platen includes one or more transv~rse 7 ¦ grooves 110 connected with an aqueous ammonia supply (not ~ ¦ shown in Figs. 5 and 6) in the ahove-described manner. A
9 ¦ pair of film advancing rollers 112 i~ positloned adjacent : 10 ¦ the downstream end and the upstream end (not shown in Fig.
11 ¦ 5) o~ the platen. The rollers are rotated in the above-12 ~ described manner to grasp the film and advance it in a 13 ¦ downstream direction.
14 ¦ ~he rollers are positioned as closely as possible 15 ¦ to the respective ends of the platens. Instead of the earlier 16 ¦ described seal strips, relatively thin and flexible sealiny 17 ¦ sheets 114 are provided. Each such sealing sheet has a 18 ¦ length equal to the length of the rollers and a width so 19 ¦ that a first portion 116 can be secured with bolts 122 to an ; 20 ¦ upper side 118 of the upper platen 104 or a lower side 120 21 ¦ of the lower platen 106~ A second portion 124 of the sealing 22 ¦ sheet extends over ~he xespective roller 112.
23 ¦ A generally Z-shaped leaf spring 126 has a horizontal 24 ¦ leg 128 secured to the platens with bolts 122, an upwardly 25 ¦ extending portion 130 and a generally horizontally disposed 2Ç ¦ spring arm 132 which overlies the sealing sheet portion 124 27 ¦ and which biases that portion into contact with and generally 28 ¦ conforms it to the perlphery of the respective roller so .~ I
: 31 3~ 1 :
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.
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1 that there is a substantial contact area between thP ~ealing 2 sheet and the roller. A seal is thereby established between 3 the developing chamber, that is between gap 108 and the 4 space between the ends of the plants and the rollers, and ~ the exteriox. The leaf-spring 126 assures a continuous 6 contact between the sealing sheet 114 and the roller and prevents the escape o~ aqueous ammonia vapors, particularly 8 in instances in which the developing chamber is operated at 1 9 the above discussed low pressures.
Further, a longitudinally extending gasket 134, 11 which may have a circular cross-section similar to the 12 cross-~ection of a standard O-ring, is placed between the 13 upper and lower platens 104 and 106 to positlvely prevent 1~ ¦ the escape of a~monia vapors from the developlng chamber. In 15¦ this manner, the developing chamber is completely sealed, 16¦ even from the surrounding housing 136 to minimize ammonia 17¦ consumption, to facilitate the ease with which spent ammonia 1~1 can be withd~awn from the developing chamber, and to prevent 191 the escape of ammonia vapors upon the opening of housing 1 201 cover 18 ~shown in Fig. 1) without requiring separate vapor ~ ¦ evacuation equipment such as ~an 100 shown in Fig. 2.
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32 I ~ -20-I
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1 as viewed in Figs. 1 and ~, without undesirable interference .
2 from the opposinq platen surfaces.
3 The lower platen includes a first groove 74 adjacen~
4 the upstream end of the platen which extends over the full effective width of the platen and which ls convexly curved 6 when viewed in a downstream direction, that is downwardly as 7 seen in Fig. 4. Additional, similarly shaped gxooves 76 are 8 disposed in the lower platen and arranged downstream of ~ groove 74. An open conduit 78 is formed in the lower platen 10¦ 66 and terminates at about the bottom center of groove 74.
11 ~ Thus, it is also located adjacent the upstream end of the 121 lower platen. The conduit is connected with an aqueous 13¦ aI~monia reservoir 80 via a metering pump 82 and a valve 84 ~4¦ 50 that upon the actuation of the pump aqueous ammonia i5 15¦ flowed into the conduit. The earlier mentioned Z-shaped 16¦ leaf-sprinqs 62 are employed to bias the upper developing 17 ¦ plate 64 downwardly against the lower plate when cover 18 is 18 ¦ closed.
19 ¦ Turning now to the operation of the developer 2, Z0 ¦ heater control 86 is initially actuated to energize heater 21 ¦ 52 of the lower preheating plate 46 and heater 68 o~ the 22 ¦ lower developing platen 66. In this connection, it should ~3 ¦ also be noted that a heater may also be applied to the upper 24 ¦ platen.s 44 and 64 although under normal operations of the developer that i5 not necessary. T~e heater control maintains 26 the platen temperature w.ithin the desired ranqe, e.g. between 2~ 150F to 200F andj preferably in the vicinity of 175F to 8 ¦ 190~F.
29 I ;~
1 : ~: ~` ' .
~ 15-~ . ~
11071~6 ' ~
1 Metering pump 82 may be selected so that it pumps 2 a ~ery low volume of aqueous ~nonia which is selected to 3 provide just enought ammonia to deuelop the fiches at whatever 4 rate they pass through the developing chamber. Alternatively, ~I the met~ring pump may be an inte~mittently operating pump 61 which is selectively activated in response to an approachi~g 7 ¦ microfiche 14. For that purpose the microfiche duplicator 8 ¦ 4 includes a sensor 88 (such as an optical sensor, for example~ which is operatively coupled with the pump and 101 activates the pump each time a microfiche approaches housing 11 ¦ intake 12, for example, to flow a metered amount of aqueous 1~¦ ammonia to conduit 78. In an alternative operational mode 13j the sensor 88 may be coupled ~lth the valve 84 downstre~m of 14 ¦ pump 82 to temporarily open ~he valve to flow the desired 15 ¦ amount of ammonia to the conduit.
16 ¦ The conduit has a configuration so that ammonia is 17 ¦ heated to about the temperature of the platen while in the 18 ¦ conduit~ This results in the evaporation of the ammonia 19 ¦ therein and the above-discussed slight pressure build up so 20 ¦ that ammonia vapor escapes from the end of conduit 78 which ~1 ¦ terminates in the upstreammost groove 74. When the platen 22 ¦ is operated at the stated temperature range and the conduit 23~ has a diameter of 1/16ths inch, a conduit length within the 2~ platen of 2-1/2 to 3 inches is sufficient to effect the 25¦ desired evaporation of the ammonia.
26¦ The drive ~not separately shown) for roller pairs 27¦ 28, 30 and 32 may be continuously or intermittently operated, 28¦ in the latter case it i5 suitably coupled with sensor 88.
29 1 ~
~; I -16-1 A microfiche 14 ~o be developed which approaches 2 intake opening 12 triggers sensor 88 and causes a meterPd 3 amount of aqueous ammonia to be flowed to conduit 78 where 4 it evaporates and escapes into the developing chamber for 5 the film. Since there is a necessary lag between the introductio 6 of aqueous ammonia to the conduit and i~s evapora~ion the 71 pump is operated a short time period before the fiche arrives at the chamber.
9¦ Once the leading edge of the fiche is grasped by ~o¦ roller pair 30 the fiche is driven in a downstream direction 11 ¦ through the space between the heating platens with its 12l emulsion side 30 facing downwardly, that is oriented so that 13 ¦ it faces the lower, heated platen 46. $he fiche, and in t4 ~ particular, the emulsion carried thereon is heated to about 15 ¦ the temperature prevailing in the de~eloping chamber. After 16 ¦ its leadlng edge issues from the downstream end of the 17 ¦ heating platen roller pair 28- advances it into and through 1B ¦ developing chamber 85.
19 ¦ Since the developing chamber has a height which is 20 ¦ only slightly greater than the thickness o the fiche the 21 ¦ downstream movemenk of the latter causes a great deal of 2Z ¦ turhulence in the alNmonia vapor escaping from conduit 78 23 ¦~ against the emulsion side of the film. Frequently, the 24 ¦ emulsion side will either contact portions oE the opposing 25 ¦ platen surface 72 ox pass closely adjacent to them to 26 ¦ furthex increase the turbulence of the ammonia vapor.
27 Additionally, as it moves over the sur~ace and the grooves 2B therein, the ammonia vapor therebetween retains its turbulence.
~9 It is believ d that this ac~ion provides repeated access for fresh ammonia vapor to the film emulsion and significantly 31 ~
32 ~ 17-~: .. _ .
i.- .
1l contributes to its the high speed development. The fully 2 developed film is then discharged from the developer into 3 receptacle 42.
4 For the above-outlined developing parameters, it 5 has been found that developing times of as little as one 6 second, or in some instances, even less than that, can be 71 achieved so that the film can be moved through the developer 8! at relatively high speeds~
gl This is achieved with a very low pressure ammonia vapor which is readily sealed so that practically no am~onia 11 odors are noticeable even in close proximity to the developer.
12 To remove ammonia condensate from the housing 13 interior a drainage opening 94 is preferably provided beneath 14 developing plate 66 which is connected with a condensate receptacle 96 via a hose 98 or the like. It should further 16 be observed that by placing the Z-shaped leaL-springs 62 17 over the gap between the respecti~e ends of the developing 1~ plates and the adjacent roller pairs 28, 30 any ammonia condensation which may form on the underside of cover 18 is 201 guided along ~he spring onto the top developing plate, from 21 1 where its flow may be guided towards drain 94 via the sides 22¦ of the platens to pre~ent ammonia droplets from contacting 23 ¦ the film. F'urther, to evacuate all ammonia vapors from the 24 ¦ housiny interior preparatory to opening cover 18, an air 25 I blower lO0 is provided to force air into the interior and to 26 thereby correspondingly force the ammonla vapors through the 2-~¦ drainage opening 94 into condensate receptacle 96 where it 281 can be absorbed in a suitab1e liquid, e.g. water bath.
~"~':
~7~6 1 ¦ Referring to Figs. 5 and 6, in an alternative 21 ~mhodiment of the inventionl a developer 102 again comprises 31 a pair of opposite upper and lower platens 104, 106 which are spaced apart as above-described, e.g. 0.20" so as to ~¦ form a gap 108 through which the film passes as it is being 6 ¦ developed~ The lower platen includes one or more transv~rse 7 ¦ grooves 110 connected with an aqueous ammonia supply (not ~ ¦ shown in Figs. 5 and 6) in the ahove-described manner. A
9 ¦ pair of film advancing rollers 112 i~ positloned adjacent : 10 ¦ the downstream end and the upstream end (not shown in Fig.
11 ¦ 5) o~ the platen. The rollers are rotated in the above-12 ~ described manner to grasp the film and advance it in a 13 ¦ downstream direction.
14 ¦ ~he rollers are positioned as closely as possible 15 ¦ to the respective ends of the platens. Instead of the earlier 16 ¦ described seal strips, relatively thin and flexible sealiny 17 ¦ sheets 114 are provided. Each such sealing sheet has a 18 ¦ length equal to the length of the rollers and a width so 19 ¦ that a first portion 116 can be secured with bolts 122 to an ; 20 ¦ upper side 118 of the upper platen 104 or a lower side 120 21 ¦ of the lower platen 106~ A second portion 124 of the sealing 22 ¦ sheet extends over ~he xespective roller 112.
23 ¦ A generally Z-shaped leaf spring 126 has a horizontal 24 ¦ leg 128 secured to the platens with bolts 122, an upwardly 25 ¦ extending portion 130 and a generally horizontally disposed 2Ç ¦ spring arm 132 which overlies the sealing sheet portion 124 27 ¦ and which biases that portion into contact with and generally 28 ¦ conforms it to the perlphery of the respective roller so .~ I
: 31 3~ 1 :
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.
, ~7~
1 that there is a substantial contact area between thP ~ealing 2 sheet and the roller. A seal is thereby established between 3 the developing chamber, that is between gap 108 and the 4 space between the ends of the plants and the rollers, and ~ the exteriox. The leaf-spring 126 assures a continuous 6 contact between the sealing sheet 114 and the roller and prevents the escape o~ aqueous ammonia vapors, particularly 8 in instances in which the developing chamber is operated at 1 9 the above discussed low pressures.
Further, a longitudinally extending gasket 134, 11 which may have a circular cross-section similar to the 12 cross-~ection of a standard O-ring, is placed between the 13 upper and lower platens 104 and 106 to positlvely prevent 1~ ¦ the escape of a~monia vapors from the developlng chamber. In 15¦ this manner, the developing chamber is completely sealed, 16¦ even from the surrounding housing 136 to minimize ammonia 17¦ consumption, to facilitate the ease with which spent ammonia 1~1 can be withd~awn from the developing chamber, and to prevent 191 the escape of ammonia vapors upon the opening of housing 1 201 cover 18 ~shown in Fig. 1) without requiring separate vapor ~ ¦ evacuation equipment such as ~an 100 shown in Fig. 2.
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Claims (30)
1. A method for developing diazo film having a sub-strate and an emulsion carried on a side of the substrate, the method comprising the steps of: placing the film in a chamber having physical chamber dimensions only slightly larger than the physical dimensions of the film; introducing aqueous ammonia vapor into the chamber at a pressure not substantially greater than atmospheric pressure so that the ammonia vapor contacts the film emulsion; and removing the film from the chamber after a relatively short time interval of no more than a few seconds.
2. A method according to claim 1 including the step of pressurizing the ammonia vapor to a pressure of no more than a few inches of water column above atmospheric pressure.
3. A method according to claim 2 wherein the step of pressurizing comprises the steps of providing a conduit which is open and terminates in the chamber proximate the film emulsion, feeding aqueous ammonia at substantially atmospheric pressure to the conduit, and heating the conduit sufficiently to evaporize the ammonia and thereby stimultaneously pressurize it suf-ficiently to discharge the vapor into the chamber.
4. A method according to claim 1 including the step of removing the film from the chamber after a stay time for film in the chamber of no more than about five seconds.
5. A method according to claim 1 including the step of providing plate means defining a substantially flat surface dimensioned to extend substantially fully across a transverse dimension of the film, placing the surface immediately adjacent and parallel to the emulsion, and moving the film and the plate means with respect to each other so as to sweep the surface over substantially the full area of the film emulsion.
6. A method according to claim 1 wherein the steps of placing the film in and removing it from the chamber comprises the steps of providing the chamber with an inlet slit at one end of the chamber and a substantially aligned outlet slit at an opposite end of the chamber, and continuously moving the film from the inlet slit through the chamber to the outlet slit.
7. A method according to claim 5 wherein the step of introducing ammonia vapor comprises the step of blowing the ammonia vapor over the emulsion side of the film as the film is moved through the chamber.
8. A method according to claim 1 wherein the intro-ducing step comprises the step of introducing the aqueous ammonia vapor at substantially atmospheric pressure and a temperature in the range of between about 150°F to about 200°F; and further including the steps of sealing the chamber from the exterior so as to prevent the escape of ammonia vapors; and removing the film from the chamber after a stay time for the film in the chamber of not substantially more than about five seconds.
9. A method according to claim 8 including the step of preheating the film to about the temperature range of the ammonia vapor before advancing the film through the chamber.
10. A method according to claim 8 wherein the step of introducing the ammonia vapor comprises the step of introducing a metered amount of ammonia vapor per microfiche passing through the chamber.
11. A method according to claim 10 including the step of sensing when a film approaches the chamber, introducing ammonia vapor into the chamber in response to sensing an approaching film, and thereafter terminating the step of intro-ducing ammonia vapor until the approach of the next film is sensed.
12. Apparatus for developing diazo film comprising means defining a developing chamber and including first and second, spaced apart, substantially parallel surfaces, a spacing between the surfaces exceeding a thickness of the film by no more than an amount required to readily move the film through the chamber; means defining an intake opening for introducing the film into the chamber and for removing it therefrom; means for moving the film through the opening and into and out of the chamber so that an emulsion side of the film passes immediately adjacent one of the surfaces; and means for applying relatively low pressure aqueous ammonia vapor into a space between the film emulsion and the one surface; whereby a rapid, low ammonia pres-sure vapor developing of the emulsion is effected.
13. Apparatus according to claim 12 wherein the open-ing defining means defines an inlet opening adjacent one end of the chamber and a separate, spaced apart outlet opening adjacent an other, opposite end of the chamber; and wherein the moving means comprises means for advancing the film through the inlet opening, the chamber and the outlet opening with the film emulsion passing in close proximity over the one surface.
14. Apparatus according to claim 13 wherein the ammonia vapor applying means comprises an ammonia vapor discharge opening in the one surface and located proximate the inlet opening.
15. Apparatus according to claim 14 including means in fluid communication with the discharge opening for distributing the ammonia vapor over a major portion of the width of the film passing through the chamber.
16. Apparatus according to claim 15 wherein the ammonia vapor distributing means comprises a groove in the sur-face fluidly communicating with the opening and extending trans-versely to the film movement direction.
17. Apparatus according to claim 16 including depres-sions in the one surface extending transversely to the film movement and located downstream of the groove.
18. Apparatus according to claim 12 including means for preheating the film before moving it into the developing chamber.
19. Apparatus according to claim 12 wherein the spacing between the surfaces is in the range of between about two to about eight times the thickness of the film.
20. Apparatus according to claim 19 wherein the spacing between the surfaces is no more than about 0.02".
21. Apparatus according to claim 12 wherein the ammonia vapor applying means includes means for pressurizing the ammonia vapor to no more than a few inches of water column above atmospheric pressure.
22. Apparatus according to claim 12 including means for applying a metered amount of the ammonia vapor to the chamber for each fiche passing the chamber.
23. Apparatus according to claim 12 wherein the chamber defining means comprises first and second, spaced apart, substantially parallel platens; a first roller pair adjacent the intake opening for the chamber and a second roller pair adjacent an outlet opening for the chamber, the roller pairs being dis-posed in close proximity to the platens; means establishing a seal between the platens and the rollers of the respective roller pairs, and gasket means between the platens sealing the developing chamber from the exterior and extending in the travel direction of the film through the chamber.
24. Apparatus according to claim 23 wherein the seal ing means comprises a relatively flexible sealing sheet for each roller, the sheet having a length substantially equal to the length of the rollers, and means intimately biasing the sheet against the platen and the roller.
25. Apparatus according to claim 24 wherein the biasing means comprises means securing the sheet to the proximate platen.
26. Apparatus according to claim 25 wherein the biasing means includes a leaf-spring arranged to bias a portion of the sealing sheet distal from the platen into engagement with a periphery of the roller.
27. Apparatus according to claim 23 including a housing surrounding the platens and having elongate apertures dimensioned to permit passage of the film substantially aligned with the intake and the outlet openings wherein the seal estab-lishing means comprises sets of cooperating, elongate, opposite rollers disposed adjacent and parallel to the apertures for receiving incoming film and discharging outgoing film, the rol-lers having resilient surfaces in mutual contact; low friction strip means sealingly disposed in corresponding grooves of the housing and arranged parallel to the rollers; and means resil-iently biasing the strip means against the rollers so as to form a seal therewith and prevent the escape of ammonia vapors through the apertures to the exterior.
28. Apparatus according to claim 27 including third and fourth platens defining a gap between them which is aligned with the chamber, the third and fourth platens being disposed between the first and second platens and the intake aperture of the housing; and means for heating at least one of the third and fourth platens to effect a preheating of the film before it enters the chamber.
29. Apparatus according to claim 23 wherein the housing includes side walls extending beyond the first and second platens; a cover placed over the side walls and the first and second platens to confine the latter to the housing; and spring means disposed between the cover and an adjacent platen for biasing the latter against the other platen.
30. Apparatus according to claim 29 wherein the spring means comprises a plurality of angularly inclined leaf-spring means having an end secured to the cover and extending over a major portion of the width of the housing to effect drainage of condensed ammonia from the cover onto the platen and to prevent such condensed ammonia from contacting film passing through the housing.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/862,720 US4150992A (en) | 1977-12-27 | 1977-12-27 | High speed, low temperature and pressure diazo processing method |
| US05/897,081 US4255037A (en) | 1978-04-17 | 1978-04-17 | High speed, low temperature and pressure diazo processing apparatus |
| US897,081 | 1978-04-17 | ||
| US862,720 | 1986-05-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1107116A true CA1107116A (en) | 1981-08-18 |
Family
ID=27127717
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA318,073A Expired CA1107116A (en) | 1977-12-27 | 1978-12-15 | High speed, low temperature and pressure diazo processing method and apparatus |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS54109841A (en) |
| CA (1) | CA1107116A (en) |
| FR (1) | FR2413692B1 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1543664A (en) * | 1966-11-03 | 1968-10-25 | Gen Aniline & Film Corp | Improvements to development devices |
| FR2114194A5 (en) * | 1970-11-19 | 1972-06-30 | Fontvielle Martine | |
| NL7400786A (en) * | 1973-02-19 | 1974-08-21 | ||
| HU168796B (en) * | 1973-04-25 | 1976-07-28 |
-
1978
- 1978-12-15 CA CA318,073A patent/CA1107116A/en not_active Expired
- 1978-12-27 JP JP16439378A patent/JPS54109841A/en active Pending
- 1978-12-27 FR FR7836505A patent/FR2413692B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54109841A (en) | 1979-08-28 |
| FR2413692B1 (en) | 1985-07-05 |
| FR2413692A1 (en) | 1979-07-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |