US3473459A

US3473459A - Photographic processing apparatus

Info

Publication number: US3473459A
Application number: US568493A
Authority: US
Inventors: Richard J Chen; Nicholas Gold
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1966-07-28
Filing date: 1966-07-28
Publication date: 1969-10-21
Anticipated expiration: 1986-10-21

Description

R. J. CHEN ET M PHOTOGRAPHIC PROCESSING APPARATUS Oct. 2l, 1969 3 Sheets-Sheet Filed July 28, 1966 IfIl/l lll] FIG.|

BY @di and (80M 8. M-

ATTORNEYS R. J. CHEN ETAL PHOTOGRAPHIC PROCESSING APPARATUS Oef. 21, 196g 3 Sheets-Sheet 2 Filed July `2e, 1966` FIG. 2

ocnzl, 1969 Q 5, CHE mL 3,473,459

PPPP OGRAPHIC PROCESSING APPARATUS Filed July 28, 1966 3 Sheets-Sheet 5 Flc-3.7 Fla-8 A M ATTORNEYS United States Patent U.S. Cl. 95-89 10 Claims ABSTRACT F THE DISCLOSURE A liquid applicator including a reservoir for holding a supply of processing duid, a multiplicity of supply capillaries communicating with the fluid in the reservoir at one end and a capillary channel having one end communieating with the other end of the supply capillaries and its other end terminating at an exterior surface of the applicator. The -supply capillaries direct a flow of processing liquid from the reservoir to the capillary channel which in turn directs it to the exterior surface of the applicator for subsequent application to a sheet of material. The aggregate liquid ow capacity of the supply capillaries is at least twice that of the capillary channel thereby insuring an adequate supply of the liquid to the capillary channel despite the clogging of a number of the supply capillaries.

This invention relates to a novel photographic processing apparatus and particularly to apparatus for treating exposed photosensitive, image-recording sheet material with a nonviscous liquid reagent.

A number of photographic processes require the application of a nonviscous liquid reagent to a photographic sheet. In a typical process, the reagent may include a lightsensitive material, a sensitizer, a reagent for processing an exposed light-sensitive layer to produce a visible image or a composition for protectively coating and/or treating a visible image. The present invention is particularly concerned with the application of liquid reagents employed to produce a visible image in a layer of an exposed lightsensitive image-recording sheet material, in apparatus such as a camera, document duplicator or the like, in which the light-sensitive material is exposed. Liquid processing reagents employed for the latter purposes are generally highly alkaline and subject to deterioration due to evaporation and contact with the atmosphere, thus requiring that the liquid be confined in such a way as to protect the apparatus and the operator from the corrosive effects of the liquid and preserve the quality and stability of the reagent itself. The problems of storing and applying the liquid are further compounded by the necessity for applying accurately predetermined quantities of the liquid uniformly and at relatively high rates, and the necessity for so doing intermittently with constant reproducible results in apparatus (such as a camera) that may be operated manually and presents the problem of spillage.

A solution to these problems is proposed in U.S. Patent No. 3,194,138, issued luly 13, 1965, in the name of Edwin H. Land and involves a so-called dry process in which the liquid is confined to and contacts only a spillproof reservoir and applicator and the sheet or sheets to which the liquid is applied. Delivery of the liquid from the reservoir to a sheet and accurate metering as well as uniform distribution of the liquid on a surface of the sheet is achieved by a capillary through which the liquid flows by capillary action.

An object of the present invention is to provide novel and improved photographic apparatus and processes of the type described in which capillary action is utilized to deliver, distribute and apply accurately predetermined quantities of a nonviscous, liquid, photographic processing Mice reagent to successive areas of photosensitive sheet material uniformly and at more rapid application rates.

Another object of the invention is to provide photographic apparatus and processes as described in which a rst capillary is utilized to distribute and apply a liquid reagent to a surface, and a multiplicity of other capillaries are utilized to deliver the liquid from a reservoir to the first capillary.

Other objects of the invention will in part be obvious and'will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts and the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

:For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a sectional, elevational view of photographic apparatus embodying the invention and performing the process thereof;

FIGS. 2 and 3 are enlarged sectional views of a liquid applicator constructed in accordance with the invention for performing the method thereof;

FIG. 4 is an enlarged sectional view of another embodiment of the liquid applicator;

FIG. 5 is a sectional view taken substantially along the line 5-5 of FIG. 4;

FIG. 6 is an enlarged view of a portion of the applicator shown in FIG. 4;

FIG. 7 is a sectional view of a further embodiment of the applicator; and

FIG. 8 is an enlarged sectional view taken substantially along the line 8-8 of FIG. 7.

The liquid applicator of the invention is especially designed for incorporation in photographic apparatus in which light-sensitive image-recording sheet material is exposed and processed to produce visible images. The apparatus may take the formv of a camera such as described in the aforementioned patent, document duplication apparatus, a printer, or the like, for performing any of a variety of image-forming processes. For purposes of illustration, the invention is described and shown as incorporated in document-copying apparatus adapted `to be employed with an integral image-recording and imagereceiving sheet comprising a support such as paper, at least one layer containing a light-sensitive material such as a silver halide emulsion, and an outer layer comprising a translucent material such as finely divided titanium dioxide, dispersed in a suitable permeable colloidal carrier or matrix, such as gelatin, which is permeable to an aqueous processing liquid. The translucent pigment may be incorporated in a layer containing a light-sensitive material and/or may comprise a separate outer layer which may also contain silver precipitating nuclei and is sufficiently transparent to permit exposure of the light-sensitive layer therebeneath, while at the same time being sufficiently opaque to provide a requisite background for a positive silver image transfer thereto by diffusion and to mask a negative image formed thereunder. Processing of the exposed image-recording sheet is accomplished by applying an aqueous liquid including a silver halide developer and 'a silver halide complexing agent to the side of the sheet opposite the support so as to impregnate the light-sensitive layer with sufficient processing liquid to produce a positive silver transfer image on the surface of the translucent layer.

Combined image-recording and image-receiving sheet materials of the foregoing type and processing performed essing composition has approximately the viscosity of Y.

water and a typical composition useful in the method and apparatus of the invention for producing silver transfer images in an exposed area of an image-recording sheet of the type described comprises the following proportions of ingredients:

Water cc 8400 Sodium sulte g 675 Sodium hydroxide g-- 180 Potassium thiosulfate g 207 4-amino-2,6dimethylphenol g 180 Aqueous solution of sodium sulfide (0.0156 g.

NazS/cc.) cc..- 9 Aqueous solution of lead acetate and cadmium acetate (08.7 g. of lead acetate and 06.3 g. of cadmium acetate/ 300 cc.) cc-- 192.0

The liquid applicator of the invention is equally well adapted for applying nonviscous liquid reagents for performing other image-forming photographic processes involving one or more sheets. For example, a processing liquid may be applied to an image-recording sheet which is thereafter pressed into contact with a separate imagereceiving sheet to produce a transfer image in the latter. Materials and processes of this type may be used to produce both black-and-white and color prints, and as an example of the latter, reference is made to U.S. Patent No. 2,983,606, issued May 9, 1961, to Howard G. Rogers, which describes the production of multicolor photographic transfer prints utilizing an integral, multilayer, imagerecording sheet incorporating dye developers. Liquid processing compositions useful in processes of the last-mentioned type also comprise highly alkaline aqueous solutions subject to deterioration (c g., oxidation) upon exposure to the atmosphere and requiring special handling and storage procedures because of their reactive and corrosive properties.

All of the foregoing photographic processes have several common requirements. These include:

1) Rapid application of the liquid, e.g., high linear speeds;

(2) Application of an accurately predetermined quantity of the liquid;

(3) Uniform liquid application; and

(4) Application of relatively small quantities of the liquid.

For example, in document duplication processes utilizing the hereinbefore described integral image-recording and image-receiving sheet, the sheet material may be moved relative to the applicator at the rate of ten inches per second to apply 1.5 cc. of the processing liquid to an area of the sheet measuring 81/2 x l1 inches. In a color process of the -type described, approximately 0.25 cc. of processing liquid is applied to an area of the sheet measuring about 3 x 4 inches and moved at the rate of nine inches per second. The foregoing examples thus provide a good indication of the preciseness with which the `liquid must be applied and the problems that must be solved in order to produce high-quality results in a dependable manner.

Reference is now made to FIGURE 1 of the drawings wherein there is illustrated document copying apparatus embodying the invention. The document copier comprises means for exposing successive areas of a combined imagerecording and image-receiving sheet, severing successive sections of the sheet each containing an exposed area, from the remainder of the sheet and means for processing the successive sections of the sheet including means for applying a nonviscous (e.g., viscosity of water) liquid reagent to one side of each of the sections.

The apparatus comprises exposure means including a window in the upper wall of the housing of the apparatus for supporting an original, e.g., document, in position for exposure to light from lamps 12 mounted within an enclosed chamber separated from the remainder of the interior of the housing by a lower wall 14 and a side wall 16. Light reiiec-ted from an original positioned on window 10 is transmitted by a conventional objective lens, part of a lens and shutter assembly 18 toward a focal plane in the apparatus at which the lens forms an image of the original. The optical system includes, in addition to the lens of assembly 18, a mirror 20 positioned beneath the lens for reecting light toward one side of the housing and means for supporting a light-sensitive image-recording sheet at the focal plane of the lens.

A supply of light-sensitive, image-recording sheet-material, designated 22, is provided coiled on a spool 24 in the lower portion of the apparatus behind mirror 20. The means for positioning successive sections of the sheet in position for exposure include a support plate 26 and a juxtaposed transparent plate 28 located in a vertical plane with the surface of the transparent plate located substantially at the focal plane of the lens. Sheet 22 is withdrawn from spool 24 and moved upwardly between

plates

26 and 28 by a pair of juxtaposed feed rolls 30 located beneath and adjacent to the lower edges of the plates.

A rotary knife 32 and anvil 34 are mounted above and adjacent the upper edges of

plates

26 and 28 for severing successive exposed sections of the image-recording sheet as each section is advanced upwardly from `between the plates between the knife and anvil. In the operation of the apparatus, a section of the image-recording sheet positioned between

plates

26 and 28 is advanced, following exposure, upwardly past the knife into engagement with liquid applicator means and then through a sheet conveyor system designed to deliver the sheets from the applicator to an exit opening in the housing of the apparatus and to provide a delivery period of sufficient duration to permit completion of the processing of the image-recording sheet within a dark environment. The sheet delivery system includes two sets of

endless conveyor belts

36 and 38. The belts 36 are mounted on support rolls 40 and 42, and belts 38 extend from support rolls 44, juxtaposed with support roll 42, upwardly in juxtaposition with belts 36 and around an enlarged drum or discs 46 and thence back to support roll 44 by way of support rolls 48 spaced around the periphery of drum or discs 46. The conveyor belts 38 which contact the side of the sheets to which the liquid is applied are preferably quite narrow in order to limit the area of contact between the belts and the sheet, and in the preferred form, may comprise conventional O-rings.

The housing of the apparatus includes an opening 50 through which the processed sheets are delivered and a pair of guides 52 extending from the opening upwardly toward the points of tangency between belts 38 and discs 46 for guiding the sheets from between the belts and discs downwardly through opening 50.

The liquid applicator of the invention is designated 54 in FIGURE 1 and is shown in detail in FIGS. 2 and 3 as comprising an elongated container S6 including a chamber for holding a quantity of the processing liquid 58. Container 56 and the chamber containing a processing liquid are approximately equal in length to the width of the area of the photosensitive sheet material to be treated. Applicator 54 includes a section providing a generally planar support surface -60 at least equal in length to the width of the sheet material to be treated for guiding and supporting the sheet material during application of the processing liquid. Support surface 60 terminates at one side of a capillary channel or slot 62 at least equal in length to the width of the area of the sheet material to be treated and having a width of capillary dimensions such that an aqueous alkaline liquid having a viscosity substantially that of water will ow through channel 62 by capillary action. Applicator 54 includes a section on the opposite side of channel 62 from surface 60 providing a surface `64 set back from surface 60 by approximately the width of capillary channel 62. The applicator including the portions thereof providing the container for the processing liquid, surfaces 60 and 64 and capillary channel 62, may be formed of any material that is compatible with the processing liquid and preferably a material that is wet lby the processing liquid in order to encourage flow thereof by capillary action. Suitable materials include organic polymers such as the acrylics, glass, ceramics and metals.

Liquid 58 is conducted from the chamber or reservoir in which it is contained, to capillary channel 62 by a multiplicity of capillaries. -In the embodiment shown in FIGS. 2 and 3, this multiplicity of capillaries provided by a fibrous wick 66 formed, for example,.of a nonwoven fabric composed of bers of a material such as polypropylene, which is compatible with the processing liquid. Applicator 54 includes a section providing a channel 68 at least approximately equal in length to capillary channel -62 and communicating between capillary channel 62 and the lower portion of the reservoir of liquid. Wick 66 substantially lls channel 68 which, in the preferred form shown in FIG. 2, extends from the bottom of the reservoir upwardly and at an angle to a position above the level of capillary channel 62. By virtue of this construction, liquid 58 is raised within channel 68 to a level above channel 62 and provides a supply head in the capillary channel.

It has been discovered that a single capillary channel or slot provides the best means for accurately metering the quantity of the processing liquid applied to the sheet material and uniformly distributed processing liquid in contact with the sheet material. A multiplicity of capillaries for conducting the liquid from a reservoir to the metering and distributing capillary provides assurance of an adequate supply of the liquid to the capillary channel despite the clogging or plugging of a number of the supply capillaries. The invention comprehends a construction incorporating a suicient number of supply capillaries for conducting at least twice the amount of liquid that can be carried by the metering and distributing capillary channel. This feature will appear more clearly in the embodiments described hereafter.

In order to provide for ow and application of the liquid by capillary action and independently of hydrostatic pressure, provision should be made for maintaining the liquid within the container of the applicator substantially atv ambient pressure. This may be accomplished in several ways including, for example, providing an opening between the atmosphere and the reservoir and/o1' incorporating a iiexible diaphragm in the reservoir as proposed in the aforementioned Patent No. 3,194,138 or as shown in FIG. 2 of the drawings. The diaphragm, designated 86 in FIG. 2, is secured in the container to the walls thereof so as to protect liquid 58 from air admitted through an opening 88 in order to maintain ,the liquid substantially at ambient pressure despite changes in the ambient pressure and in the level of the liquid within the container. A similar diaphragm arrangement may also be provided in embodiments of the applicators described hereafter.

The processing liquid is applied to sheet 22 by moving the sheet upwardly against surface 60 across capillary channel 62 and surface 64 in a direction generally perpendicular to the length of the capillary channel. The liquid is conducted from the ,reservoir to the capillary channel `by wick 66 and the capillary channel performs the function of uniformly distributing a metered amount of the liquid in contact with the sheet as the sheet is moved past the channel. An applicator for applying a liquid coating to an 8'1/2 x l1 inch sheet moved past the applicator at the rate of ten inches per second according to the example given, has been constructed with a capillary channel 62 having a width of 0.005 inch and a depth of 0.05 inch with surface 64 set back from surface 60 by 0.005 inch to provide a space between the sheet material and surface 64 in which the liquid Vdrawn from capillary channel 62 may be coated as a layer on the surface of the paper prior to being absorbed therein.

1In connection with the specific dimensions and the operation of the applicator, it has been discovered that the quantity of liquid applied is directly related to the width of capillary channel 62 and the linear rate of movement of the sheet material past the capillary channel as well as relatively noncritical factors such as the depth of the liquid in the reservoir. The simplest formv of control over the quantity of liquid applied is achieved by varying the speed of movement of the sheet material past the capillary channel. The applicator including the container of liquid lends itself to fabrication from inexpensive materials so that the applicator may be initially supplied with sufficient liquid to process a predetermined quantity vof sheet material and may be thrown away when the liquid is expended. In apparatus such as a document copier, it may be desirable to provide a more permanent applicator structure, a separate reservoir for the processing liquid, together with means for feeding the processing liquid from the reservoir to a chamber in the applicator and controlling the level of the liquid within the chamber in the applicator.

A backing roll preferably having a surface with a high coefficient of friction, e.g., an elastomer such as polyurethane, is mounted with its surface tangent to surface 60 closely adjacent the edge of capillary channel 62. Means are provided for rotating roll 70 (in a counterclockwise direction) for supporting and moving a sheet against surface 60 across channel 62. In the operation of the document copier shown in FIGURE l, sheet 22 is advanced upwardly past knife 32 between surface 60 and' roll 70 and thence into engagement between

belts

36 and 38 at

rolls

42 and 44 and rotation of all of the sheetadvancing rolls and belts is coordinated to insure movement of the sheet material at a constant predetermined speed particularly during processing including liquid application and the subsequent processing period.

Following each liquid application operation, it may be desirable to seal capillary channel 62 to prevent evaporation of the liquid within the capillary channel. The capillary channel can be sealed simply by pressing roll 70 against

surface

60 and 64 so that the surface of the roll engages

surface

60 and 64 on opposite sides of and at the ends of the capillary channel as shown in FIG. 6. Suitable means, the construction of which is considered to be within the skill of the art, may be provided for displacing applicator 54 and roll 70 relative to one another so as to seal the capillary channel as shown.

An alternative embodiment of the applicator of the invention is shown in FIGS. 4 through 6 and designated 72. Applicator 72 is essentially the same as applicator 54 and includes

surface

60 and 64 on opposite sides of a capillary channel 62 and a container including a chamber or reservoir 74 for containing the processing liquid. The liquid in chamber 74 is conducted to capillary channel 62 by a multiplicity of capillaries comprising at least two rows of contiguous capillary channels 76 extending upwardly from the lower part of chamber 74 and communicating with capillary channel 62. Channels 76 are defined by a member 78 formed with grooves in its outer surface and secured in a mating recess in a section of applicator 72 with the grooves in the outer surface of member 78 cooperating with the walls of the recess to define capillary channel 76. The grooves defining the capillary channel may have any convenient crosssectional coniiguration including hemispherical as shown or other conigurations such as rectangular and V-shaped. Member 78 and the recess in which it is held is generally rectangular in shape with one side being cylindrical so that the grooves in the outer surface of member 78 may be continuous and communicate with channel 62 which opens at its inner side into the recess containing member 78.

Another embodiment of the applicator is shown at 80 in FIGS. 7 and 8 and differs from applicator 54 in the construction of the multiplicity of capillaries for conducting the liquid from a chamber or reservoir 74 to capillary channel 62. Applicator 80 includes a section having a channel 82 extending from the lower part of chamber 74 to the inner side of capillary channel 62. The walls of channels 82 are generally planar and parallel and are spaced from one another by slightly more than the walls of capillary channel 62 and the multiplicity of capillaries is provided by a thin corrugated membrane 84 engaged between walls of channel 82 and dividing the channel into a multiplicity of capillary channels for conducting the liquid from chamber 74 to capillary channel 62.

While the applicators have been shown and described as being oriented in particular positions during liquid application operations, liquid feeding is accomplished rby capillary action rather than by flow of the liquid due to hydrostatic pressure thereby enabling the applicators shown to function in positions other than shown and described. The only limitation on orientation of the applicators is that the ends of the capillaries in the reservoir be emersed in the processing liquid so that in a construction of the type shown in FIG. 2 incorporating a wick, the wick may extend into the reservoir so as to be emersed in a liquid regardless of the orientation of the applicator. This construction would permit the applicator to be employed in apparatus such as a camera which is held and operated by hand and may be oriented in any number of positions during liquid application operations.

In accordance with the enumerated objects of the invention, the applicant has described apparatus for applying accurately predetermined quantities of a nonviscous liquid photographic processing reagent, uniformly to successive areas of photographic sheet material. The liquid applicator is suitable for incorporation in a variety of types of photographic apparatus for performing a variety of processes and its operation is dependable while being independent of such variable factors as hydrostatic pressure of the reservoir of liquid, atmospheric pressure and orientation of the applicator during use.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Photographic processing apparatus for applying a predetermined quantity of a monviscous liquid reagent uniformly to each of a succession of areas of photographic sheet material comprising, in combination:

means providing a reservoir for holding a nonviscous liquid reagent;

an applicator member having at least an outer surface for supporting a photographic sheet;

said applicator member including an elongated capillary channel extending into said applicator member from said surface, said channel being relatively shallow and terminating at one side at said surface and at its other side within said applicator member; means within said applicator member defining a second channel larger than capillary size, at least equal in length to said capillary channel and extending from within said reservoir toward said capillary channel and terminating at said other side thereof; means contained in said second channel providing a multiplicity of capillaries extending from end to end thereof;

means for supporting a sheet against said surface; and

means for effecting the movement of said sheet relative to and across said channel transversely of the length thereof to transfer said liquid from said channel to said sheet.

2. Photographic apparatus as defined in claim 1 wherein said multiplicity of capillaries has an aggregate liquid flow capacity of the order of at least twice the liquid flow capacity of said capillary channel.

3. Photographic apparatus as defined in claim 2 wherein said means providing said multiplicity of capillaries comprise means defining a multiplicity of contiguous capillary tubes arranged in at least two rows extending from end to end of said capillary channel, said tubes having terminations at said other side of said capillary channel and Within said reservoir.

4. Photographic apparatus as defined in claim 2 wherein said multiplicity of capillaries substantially fll said second channel.

5. Photographic processing apparatus for applying a predetermined quantity of a nonviscous liquid reagent uniformly to each of a succession of areas of photographic sheet material comprising, in combination:

means providing a reservoir for holding a nonviscous liquid reagent;

said applicator member including an elongated capillary channel extending into said applicator member from said surface, said channel being relatively shallow and terminating at one side at said surface and.

at its other side within said applicator member;

means providing a multiplicity of capillaries within said applicator member communicating with said capillary channel at said other side thereof and with a lower portion of said reservoir;

means for supporting a4 sheet against said surface;

means for effecting the movement of said sheet relative to and lacross said channel transversely of the length thereof to transfer said liquid from said channel to said sheet; and

said surface includes a first section extending to and defining one edge of said capillary channel and a second section extending to and defining the opposite edge of said capillary channel, said second section being located in a plane set inwardly from the plane of said first section; and

the last-mentioned means including means for supporting and moving said sheet against said first section of said surface across said channel without contacting said second section of said surface.

6. Photographic apparatus as defined in claim 5 wherein said second section is inset from said first section by substantially the width of said channel.

7. Photographic processing apparatus for applying a predetermined quantity of a nonviscous liquid reagent uniformly to each of a succession of areas of photographic sheet material comprising, in combination:

means providing a reservoir for holding a nonviscous liquid reagent;

an applicator member having at least an outer surface for supporting a photographic sheet; said applicator member rincluding an elongated capillary channel extending into said applicator member from said surface, said channel being relatively shallow and terminating at one side at said surface and at its other side within said applicator member;

means defining a multiplicity of contiguous capillary tubes arranged in at least two rows extending from end to end of said channel and communicating with said capillary channel at said other side thereof and with a lower portion of said reservoir, said capillary tubes being defined by adjacent walls of adjacent members, one wall of each adjacent pair of walls having grooves therein extending from said reservoir to said capillary channel;

means for supporting a sheet against said surface; and

8. Photographic processing apparatus for applying a predetermined quantity of a nonviscous liquid reagent uniformly to each of a succession of areas of photographic sheet material comprising, in combination:

means providing a reservoir for holding a nonviscous liquid reagent;

an applicator member having at least an outer surface for supporting 'a photographic sheet;

said applicator member including an elongated capillary channel extending into said applicator member from said surface, said channel being relatively shallow land terminating at one side at said surface and at its other side within said applicator member;

means within said applicator member defining a second channel larger than capillary size, at least equal in length to said capillary channel and extending from said capillary channel to said reservoir, and a wick contained in said second channel, extending from end to end thereof and immersed in the liquid contained in said reservoir;

means for supporting a sheet against said surface; and

means for effecting the lmovement of said sheet relative to and across said channel transversely of the length thereof to transfer said liquid from said channel to said sheet.

9. Photographic apparatus as defined in claim 8 wherein said second channel extends within said applicator member to a position above said capillary channel.

10. Photographic processing apparatus for applying a predetermined quantity of a nonviscous liquid reagent uniformly to each of a succession of areas of photographic sheet material comprising, in combination:

means providing a reservoir for holding a nonviscous liquid reagent;

said applicator member including an elongated capillary channel extending into said applicator member from said surface, said channel being relatively shallow and terminating at one side at said surface and at its other side within said applicator member;

means providing a multiplicity of capillaries within said applicator member, said means include a second channel in said applicator member at least equal in length to said capillary channel and communicating with said capillary and said reservoir throughout its length; and a corrugated membrane Within said second channel cooperating with the walls thereof to form said capillaries;

means for supporting a sheet against said surface; and

means for effecting the movement of said sheet relative to and lacross said channel transversely of the length thereof to transfer said liquid from said channel to said sheet.

References Cited UNITED STATES PATENTS 8/1965 Herrick 118-401 X U.S. Cl. X.R.