Photographic processor having an adjustable drum

Abstract

A photographic processor having a circular processing drum is shown. The circular processing drum of the processor of the present invention includes a disk that is positioned inside the drum. In order to accommodate different types of film, the circular processing drum is adjustable to change the width and thereby, change a size of the film path within the circular processing drum.

Description

FIELD OF THE INVENTION

The present invention is directed to a photographic processor having a circular processing drum, and more particularly, to a photographic processor having a circular processing drum with an adjustable width to accommodate different types of film.

BACKGROUND OF THE INVENTION

Photographic processors come in a variety of shapes and sizes from large wholesale photographic processors to small micro-labs. As photographic processors become more and more technologically sophisticated, there is a continued need to make the photographic processor as user-friendly and as maintenance-free as possible.

Currently available photographic processors have one or more of the following shortcomings: (1) the film processing time is relatively high; (2) some photographic processors, because of their size, require a large amount of space, (3) some photographic processors may require an unacceptable amount of developing solution due to the design of the processing tank; and (4) some photographic processor generate an unacceptable amount of developing solution waste due to the design of the processing tank.

What is needed in the art is a portable photographic processor, which provides exceptional print quality while requiring a minimal number of tasks necessary for an operator to process a roll of film. What is also needed in the art is a portable photographic processor, which is designed to efficiently process a variety of films while minimizing the amount of waste generated during the photographic process.

SUMMARY OF THE INVENTION

The present invention addresses some of the difficulties and problems discussed above by the discovery of a novel, compact, and portable photographic processor having an internal drum design, which minimizes the chemicals required to process a roll of film and consequently minimizes the amount of waste generated per roll of film processing. The photographic processor is extremely user-friendly and low maintenance.

The present invention relates to a photographic processor which comprises an adjustable circular processing drum assembly having a first wall, a second wall, a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, with the circular drum assembly further comprising a circular film path for film to be processed therein. The perimeter wall member comprises a first portion attached to the first wall and a second portion which overlaps the first portion and is attached to the second wall. A distance between the first and second walls is adjustable by changing an amount of the overlap between the first and second portions of the perimeter wall member between a first overlap amount to accommodate a first type of film in the film path and a second overlap amount which is less that the first overlap amount to accommodate a second type of film in the film path. The processor further comprises a disk positioned inside the processing drum in a plane parallel to both the first wall and the second wall with the disk comprising one or more sets of disk teeth along an outer perimeter of the disk for interengaging with holes along an edge of the first or second type of film.

The present invention further relates to a photographic processor which comprises: an adjustable circular processing drum assembly including a first wall, a second wall, a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, with the circular drum assembly further comprising a circular film path for film to be processed therein. The perimeter wall member comprises an adjustable bellows which changes a distance between the first and second walls between a first distance to accommodate a first type of film in the film path and a second distance which is less that the first distance to accommodate a second type of film in the film path. The processor further comprises a disk positioned inside the processing drum in a plane parallel to both the first wall and the second wall. The disk comprises one or more sets of disk teeth along an outer perimeter of the disk for interengaging with holes along an edge of the first or second type of film.

The present invention relates to a photographic processor which comprises an adjustable circular processing drum assembly which includes a first wall, a second wall, a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, with the circular drum assembly further comprising a circular film path for film to be processed therein. The processor further comprises a mechanism for adjusting a distance between the first and second walls between a first distance for accommodating a first type of film in the film path and a second distance which is smaller than the first distance for accommodating a second type of film in the film path; and a disk positioned inside the processing drum in a plane parallel to both the first wall and the second wall. The disk comprises one or more sets of disk teeth along an outer perimeter of the disk for interengaging with holes along an edge of the first or second type of film.

The present invention further relates to a method of processing a photographic film which comprises the steps of: changing a width of an adjustable circular processing drum to a first width in accordance with a first type of film to be processed, to accommodate the first type of film; inserting the first type of film into the adjustable circular processing drum; and supplying and discharging processing solution into and from the adjustable processing drum to process the first type of film.

The present invention further relates to a method of processing a photographic film which comprises the steps of: adjusting a width of a circular processing drum between at least first and second widths in accordance with a film to be processed to accommodate the film in a film path in the circular processing drum; inserting the film into the circular processing drum, and supplying and discharging processing solution into and from the processing drum to process the film.

These and other features and advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiments and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described with reference to the appended figures, wherein:

FIG. 1 is a frontal view of an exemplary photographic processor of the present invention;

FIG. 2 is a rear view of an exemplary photographic processor of the present invention;

FIG. 3 depicts an exemplary circular processing drum used in the photographic processor of the present invention;

FIG. 4 depicts an exemplary disk located within the circular processing drum of the present invention;

FIG. 5 displays a close-up view of an exemplary disk having an outer perimeter and one or more sets of disk teeth;

FIG. 6 depicts an exemplary roller mechanism positioned within the circular processing drum,

FIG. 7 depicts a rear view of the exemplary roller mechanism of FIG. 6 ;

FIG. 8 depicts an exemplary drum and disk drive mechanism for rotating a circular processing drum, and a clutch mechanism for selectively engaging the drum and disk;

FIG. 9A displays a cross-sectional view of the drum and disk drive mechanism along line 9 A— 9 A in FIG. 8 ;

FIG. 9B schematically illustrates a driving and clutching arrangement of the invention;

FIG. 10 depicts a film cartridge in a film-loading position using one film-loading method of the present invention;

FIG. 11 depicts a film cartridge stabilizing step in one film-loading method of the present invention;

FIG. 12 depicts a film nipping step during a film-loading method of the present invention;

FIG. 13 depicts a cross-sectional view of film entering into a circular processing drum in one film-loading method of the present invention;

FIG. 14 depicts a sheet of film having a lead end and a tail end within the drum processing cavity of a circular processing drum;

FIGS. 15A and 15B depicts an exemplary film transfer arm, which transfers film from a circular processing drum to a dryer;

FIG. 16 depicts an exemplary film loading/unloading device used in a film-loading method of the present invention wherein film is separated from its corresponding film cartridge;

FIG. 17 depicts a cross-sectional view of the exemplary film loading/unloading device as seen along line 17 — 17 in FIG. 16 ;

FIG. 18 depicts an exemplary film-loading guide used to load a film roll into a circular processing drum;

FIG. 19 depicts a film transfer step, wherein a strip of film is transferred from a circular processing drum to a dryer by film sheet gripper rolls attached to a film transfer arm;

FIG. 20 depicts a film processing step, wherein a strip of film exits a dryer into a scanner festoon box;

FIG. 21 depicts a film processing step, wherein a strip of film exits a festoon box and proceeds to a scanner; and

FIGS. 22A-22C show a further embodiment of a processing drum in accordance with the present invention;

FIGS. 23A-23C show a processing drum in accordance with a still further embodiment of the present invention; and

FIGS. 24A-24C illustrate an example of an actuator for an adjustable width processing drum in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to photographic processors. An exemplary photographic processor of the present invention is shown in FIG. 1 . The photographic processor 10 comprises at least an outer housing, which includes a first side wall 11 , a base housing member 12 , and second side wall 13 . The photographic processor 10 includes a circular processing chamber 14 (also referred to herein as the “circular processing drum 14 ”), which may be used to expose a given strip or roll of film to one or more photoprocessing chemicals. Photographic processor 10 further includes a film-loading/unloading device 15 positioned above and cooperating with circular processing drum 14 . A chemical delivery system 16 is positioned for easy access by a user (i.e., for maintenance or replacement purposes) at a location near side wall 13 and base housing member 12 . Photographic processor 10 also includes a circular dryer 17 in the form of, for example, a cylinder, for drying the processed film. Dryer 17 is concentrically and co-axially positioned around processing drum 14 . Once a given strip or roll of film is dried in dryer 17 , the film proceeds to a scanner 18 ′, which may be positioned above chemical delivery system 16 in a space bordered by side wall 13 and left interior wall 18 or any other convenient location.

FIG. 2 depicts a rear view of photographic processor 10 . As shown in FIG. 2 , photographic processor 10 includes opening 19 in side wall 13 for accessing chemical delivery system 16 . Sliding track mechanism 20 allows an operator to pull at least a portion of chemical delivery system 16 through opening 19 to an exterior location outside of photographic processor 10 . Such an assembly allows for quick and easy maintenance and replacement of chemical delivery system 16 . Photographic processor 10 can include a waste collection reservoir 21 , which collects and stores used processing chemicals removed from circular processing drum 14 following development of a given strip or roll of film. As shown in FIG. 2 , dryer 17 includes dryer entrance 171 and dryer blower 172 . The various components of photographic processor 10 will be described in more detail below with reference to FIGS. 3-21 .

Circular processing drum 14 is further described in FIG. 3 . As shown in FIG. 3 , circular processing drum 14 includes a first wall 141 , a second wall 142 , a side wall 143 , and a central axis opening 144 . A portion of a drum and disk drive mechanism 25 (shown in FIGS. 2 , 8 and 9 ) passes through central access opening 144 . Circular processing drum 14 comprises two circular sections joined together at multiple locations around the perimeter of circular processing drum 14 via male clasping members 145 and female clasping members 146 . It should be noted that any means for attaching the two circular components of circular processing drum 14 may be used in place of male clasping members 145 and female clasping members 146 . Further, it should be noted that circular processing drum 14 may also consist of a single component as oppose to two circular components as shown in FIG. 3 , although such a design may add manufacturing cost to circular processing drum 14 . Circular processing drum 14 further comprises a film cartridge loading area 147 on an outer surface of side wall 143 for loading film directly from a film cartridge into circular processing drum 14 , such as with APS film. Circular processing drum 14 also comprises a film input slot 148 , which enables the entry and exit of film into circular processing drum 14 .

FIG. 4 depicts an exemplary disk 30 , which is positioned within circular processing drum 14 , and functions to convey film within circular processing drum 14 once the film enters through film input slot 148 . Disk 30 includes a first face 31 , a second face 32 , a central access opening 33 , an outer perimeter 34 , and one or more sets of disk teeth 35 located along outer perimeter 34 of disk 30 . As with circular processing drum 14 , a portion of drum and disk drive mechanism 25 may extend into central access opening 33 to engage with and cause rotation of disk 30 . FIG. 5 provides a close-up view of a portion of disk 30 , and in particular, outer perimeter 34 and a set of disk teeth 35 on the outer perimeter 34 of disk 30 . The outermost points of disk teeth 35 are in close proximity to an inner surface of side wall 143 of circular processing drum 14 . In a feature of the invention, disk teeth 35 could be spring loaded through the use of springs 35 a.

In one feature of the present invention, a roller arrangement 27 ( FIGS. 6 and 7 ) is positioned within circular processing drum 14 . Roller arrangement 27 includes a roller 270 having interengaging members 277 and 278 (FIG. 7 ). Roller arrangement 27 may be supported by a support member 28 , which is attached to a support member base 29 . Support member base 29 may be permanently or temporarily attached to base housing member 12 (shown in FIGS. 1 and 2 ). Roller arrangement 27 includes a motor 271 , which provides motion to pistons 272 through openings 273 in a fixed positioning member 274 . Pistons 272 proceed through stationary positioning support member 276 and are attached to movable positioning support member 275 . As pistons 272 move, movable positioning support member 275 which is coupled to member 277 separates from stationary positioning support member 276 which is coupled to member 278 . This permits roller 270 to be expandible between a first width when the members 277 and 278 overlap each other and a second width larger than the first width ( FIG. 7 ) when the members 277 and 278 move away from each other.

FIG. 7 provides a detailed view of roller arrangement 27 and its various components. As shown in FIG. 7 , movable positioning support member 275 and stationary positioning support member 276 connect to interengaging members 277 and 278 respectively as described above. During use, the film passes between roller 270 and an interior surface of drum 14 . Roller 270 is freely rotatable and maintains the film flat along the lower portion of drum 14 . As will be described later, roller 270 further provides an agitating feature within processing drum 14 during processing. Additionally, the width of roller 270 is adjustable as described above to accommodate a shorter width film (i.e. APS film) and a larger width film (i.e. 35 mm film). Further, roller arrangement 27 including roller 270 can be vertically adjustable to accommodate for film curl as the film passes between roller 270 and the interior surface of drum 14 . As a still further option, roller 270 can be spring loaded so as to accommodate any variation in the interior surface of drum 14 .

In a further embodiment of the present invention, circular processing drum 14 is connected to a drum and disk drive mechanism 25 , which selectively rotates disk 30 relative to drum 14 to position and convey the film along and within processing drum 14 , and rotates both disk 30 and drum 14 together during a processing cycle. Circular processing drum 14 rotates about an axis of symmetry. An exemplary drum and disk drive mechanism 25 is shown in FIG. 8 . Drum and disk drive mechanism 25 cooperates with a motor 22 , a belt 23 , and a pulley 24 as shown in FIGS. 8 and 9A . Drum and disk drive mechanism 25 includes a drive shaft 261 which is operationally connected to pulley 24 . Also shown in FIGS. 8 and 9A are flanges 251 and 252 . Flange 251 is connected to drum 14 while an end cap 300 holds disk 30 for rotation about drive shaft 261 (FIG. 9 A). Actuation of motor 22 drives belt 23 which in turn drives pulley 24 . This in turn causes a rotation of drive shaft 261 which rotates disk 30 . Clutch mechanism 250 enables the engagement and disengagement of flange 251 to provide selective rotation to circular processing drum 14 .

FIG. 9A displays a cross-sectional view of drum and disk drive mechanism 25 and clutch mechanism 250 along line 9 A— 9 A in FIG. 8 . With reference to FIG. 9 A and FIG. 9B which is a schematic representation of the driving and clutching feature of the present invention, an operation will now be described. When loading film which will be described with reference to FIGS. 10 and 11 , clutch 250 is deactivated as shown in FIG. 9 B. In this state, rotation of motor 22 will cause a rotation of drive shaft 261 and accordingly, a rotation of disk 30 relative to drum 14 . This is due to the fact that clutch 250 is deactivated and therefore, drum 14 is not rotated. This permits the conveyance of the film by rotation of disk 30 to a desired location within drum 14 . After the film reaches the desired location within drum 14 , clutch 250 is activated, (for example, clutch 250 is moved to the right in FIG. 9B ) by actuating clutch 250 with flange 251 which is attached to drum 14 . Therefore, a rotation of motor 22 will cause a rotation of both disk 30 and drum 14 . This occurs during the processing stages to process the film in a manner which will be described later.

In a further feature of the invention, drive shaft 261 can be moved perpendicularly and through flange 251 and flange 252 to move disk 30 attached thereto. As shown in FIG. 9A , drive shaft 261 is attached to a fitting 264 in a manner which permits drive shaft 261 to rotate relative to fitting 264 . Fitting 264 is in turn rotatably attached to a pivotable arm 262 and a movable member 263 . Movable member 263 can be operationally connected to a motor for rotation of member 263 . This causes arm 262 to pivot about point 262 ′ to move drive shaft 261 to the left or right when viewing FIG. 9A from above the page. Movement of drive shaft 261 as noted above, moves disk 30 in a direction parallel to an axis of disk 30 . This facilitates the accommodation of, for example, 35 mm and APS film on disk 30 , since the disk 30 can be moved based on the type of film being processed.

Within the context of the present invention, a film may be loaded into circular processing drum 14 by a number of methods. One method of loading film, such as APS film, into circular processing drum 14 is shown in FIGS. 10-13 . As shown in FIG. 10 , film cartridge 40 comprising a film cartridge spool 41 and film cartridge door opening mechanism 52 is positioned in a film cartridge loading area 147 located on side wall 143 of circular processing drum 14 . Film (not shown) exiting film cartridge 40 enters circular processing drum 14 at light tight film input slot 148 ( FIG. 3 ) in side wall 143 of circular processing drum 14 .

Once film cartridge 40 is positioned in film cartridge loading area 147 , the photographic processor 10 of the present invention initiates a number of film-loading and conveying steps, the results of which are shown in FIG. 11 . It is noted that the film loading and conveying steps as well as other processing steps can be controlled by a computer or central processing unit 2000 ( FIG. 1 ) operationally associated with processor 10 . In a first step, a film cartridge stabilizing member 50 applies an amount of pressure onto an upper surface of film cartridge 40 to prevent film cartridge 40 from moving while positioned in film cartridge loading area 147 . Spool engaging member 51 and cartridge door opening mechanism engaging member 52 move toward film cartridge 40 and engage with film cartridge spool 41 and film cartridge door 42 , respectively. Door opening mechanism engaging member 52 opens film cartridge mechanism 42 and spool engaging member 51 begins to rotate film cartridge spool 41 , forcing film (not shown) out of film cartridge 40 .

FIG. 12 shows a strip of film 43 exiting film cartridge 40 and entering film input slot 148 of circular processing drum 14 . Driven nip rollers 150 grasp a leading edge of the strip of film 43 at drum roller nip point 151 and advance film 43 further into circular processing drum 14 . As shown in FIG. 13 , the strip of film 43 exits drum cavity slot 152 and enters into the drum processing cavity 1521 of circular processing drum 14 , wherein one or more sets of disk teeth 35 on disk 30 interengage with holes or perforations along an edge of the strip of film 43 . As previously described, disk teeth 35 could be spring loaded so as to spring up at the appropriate time and interengage with the holes or perforations along film 43 . With clutch 250 disengaged, disk 30 and rollers 150 are rotated while circular processing drum 14 remains stationary. This causes film 43 to advance into the processing cavity 1521 of circular processing drum 14 a desired distance equal to the length of the strip or roll of film 43 . As shown in FIGS. 10-13 , in this film-loading method of the present invention, the film 43 remains intact with film cartridge 40 .

A number of commercially available films may be loaded according to the film-loading method described above, namely, wherein the film remains intact with its corresponding film cartridge during processing. A suitable film, which may be used in this particular film-loading method, includes, but is not limited to, APS film. Desirably, APS film is loaded into the photographic processor of the present invention according to this method.

FIG. 14 depicts circular processing drum 14 fully loaded with film 43 having a forward end 431 and a rearward end 432 within the drum processing cavity 1521 of circular processing drum 14 . The back end of film 43 is maintained in cartridge 40 . Film 43 is now positioned within circular processing drum 14 for chemical processing, wherein one or more processing fluids are deposited into circular processing drum 14 and placed in contact with film 43 for a desired period of time.

It is noted that the circumference of the drum will be longer than the length of the film to be processed. Therefore, when the film is loaded in drum 14 , a section of drum 14 will not have film therein. This is referred to as a film-free zone 431 ′ (FIG. 14 ). Prior to delivering chemistry by way of chemical supply 16 and a chemical delivery mechanism 16 ′ (FIG. 14 ), clutch 250 is activated or engaged and drum 14 is controllably rotated with disk 30 so that film-free zone 431 ′ is at a lower end or below chemical delivery mechanism 16 ′. Chemical delivery mechanism 16 ′ is preferably of the type which drops or delivers chemistry into drum 14 in the direction of arrow 1600 (FIG. 14 ). The movement of film-free zone to an area below chemical delivery mechanism 16 ′ prior to the delivery of chemicals prevents the chemicals from being dropped directly on the film which could cause uneven processing. Thereafter, processing occurs by continuously rotating the drum 14 and disk 30 . Further, as shown in FIG. 14 , in the lower portion of drum 14 , film 43 passes between wheel 270 and an inner surface of drum 14 . Rotation of drum 14 and disk 30 relative to wheel 270 helps to agitate the processing fluid in the vicinity of wheel 270 to promote processing. Following the chemical processing steps, the film 43 is removed from circular processing drum 14 and exposed to a drying operation. One method of removing film 43 from circular processing drum 14 is shown in FIGS. 15A and 15B .

As shown in FIG. 15A , film transfer arm assembly 60 is positioned to move or pivot between circular processing drum 14 and dryer 17 . Film transfer arm assembly 60 includes a lower arm member 61 , which is rotatable around an axis of symmetry 153 of circular processing drum 14 . Film transfer arm assembly 60 also includes an upper arm member 62 , which is pivotally attached to lower arm member 61 . At upper arm member end 63 , film transfer arm assembly 60 includes a film cartridge gripper 64 and film strip gripper rolls 65 . As shown in FIG. 15B , which is a front view of the entrance of dryer 17 , a side wall of dryer 17 includes a slot 1700 with a rubber seal that extends along the length of the dryer. Upper arm member 62 includes a shaft 620 which extends from upper arm member 62 , through slot 1700 and is connected to gripper 64 . This permits transfer arm assembly 60 to pull gripper 64 and thus the film to be dried though the dryer.

In embodiments wherein the film 43 remains intact with film cartridge 40 (as described above), film cartridge gripper 64 of film transfer arm assembly 60 engages with film cartridge 40 , pulls film cartridge 40 from loading area 147 and the strip of film 43 from circular processing drum 14 in direction 600 a, and proceeds through dryer 17 in direction 600 b. Therefore, cartridge 40 with processed film 43 attached and trailing therefrom is conveyed through dryer 17 to dry film 43 by, for example, the blowing of air into dryer 17 . In other embodiments where the film 43 is detached from film cartridge 40 (described below), film sheet gripper rolls 65 grip an edge of film 43 as film 43 exits film input slot 148 of circular processing drum 14 . Film sheet gripper rolls 65 of film transfer arm assembly 60 pull film 43 from circular processing drum 14 and proceeds through dryer 17 . Once dried, film 43 is re-wound back into its cartridge 40 prior to proceeding to scanner 18 ′.

In a further film-loading method of the present invention, the film is separated from its film cartridge prior to processing within circular processing drum 14 (for example, 35 mm film). In this method, a film loading/unloading device, such as exemplary film loading/unloading device 15 as shown in FIG. 16 , may be used. Film loading/unloading device 15 includes a film cartridge loading area 154 , which can be enclosed by closing a door 158 . In film loading area 154 , an operator extracts the tongue of film 43 ′ from cartridge 40 ′ and engages the perforations on film 43 ′ with sprockets on a driven roller 1570 . Thereafter door 158 is closed and film 43 ′ proceeds into festoon box 155 through festoon box nip rollers 156 . Once a desired length of film is removed from film cartridge 40 ′, a cutter 157 slices film 43 ′ to separate film 43 ′ from film cartridge 40 ′. Any counter device (not shown) may be used to measure the length of the strip of film 43 ′ passing through festoon box nip rollers 156 . The length measurement is used in further processing steps as described below.

FIG. 17 depicts a cross-sectional view of film loading/unloading device 15 as seen along line 17 — 17 in FIG. 16 . As shown in FIG. 17 , film cartridge 40 ′ is positioned in film cartridge loading area 154 while a strip of film 43 ′ is removed from film cartridge 40 ′ and transported to festoon box 155 where it is turned. In this film-loading operation, a reverse roll of film 431 is formed from the film 43 ′ in festoon box 155 . A lead end of film 432 becomes the innermost portion of the reverse roll 431 while a tail end of film 433 becomes the outermost portion of reversed roll 431 . When the film 43 ′ is subsequently fed into circular processing drum 14 (as previously described), tail end 433 , which contains the last exposures on the strip of film 43 ′, is fed into circular processing drum 14 first.

A film-loading guide 159 is used to load reverse roll 431 into circular processing drum 14 as shown in FIG. 18 . Festoon box 155 rotates from an initial position (as shown in FIGS. 16 and 17 ) to a film-loading position as shown in FIG. 18 . Festoon box nip rollers 156 turn to advance tail end 433 of reverse roll 431 into film-loading guide 159 at guide entrance slot 1591 . The film 43 ′ exits the film-loading guide 159 at guide exit slot 1592 positioned adjacent to film input slot 148 of circular processing drum 14 . Once the tail end 433 of the strip of film 43 ′ enters into circular processing drum 14 , driven nip rollers 150 grab the film 43 ′ and advance the film 43 ′ into circular processing drum 14 as described above. It should be noted that in this film-loading method, nip rollers 150 are programmed to advance the film 43 ′ into circular processing drum 14 a specific length, which corresponds to the length of film inputted into festoon box 155 and measured via festoon box nip rollers 156 as described above. In other words, nip rollers 150 advance the strip of film 43 ′ into circular processing drum 14 so that lead end 432 of film 43 ′ remains nipped between nip rollers 150 during chemical processing (i.e., lead end 432 of the strip of film 43 ′ does not enter into drum processing cavity 1521 ). This permits all of the exposed areas of the film 43 ′ to be in the processing area in the drum.

Following the chemical processing steps, film 43 ′ is transferred to dryer 17 by film transfer arm assembly 60 as described above. As shown in FIG. 19 , the strip of film 43 ′ is pulled from circular processing drum 14 through film input slot 148 by film sheet gripper rolls 65 attached to upper transfer arm member 62 . Nip rollers 150 provide a first end (corresponding to lead end 432 ) to film sheet gripper rolls 65 . In FIG. 19 , film sheet gripper rolls 65 are shown positioned at dryer entrance 171 . From this position, film sheet gripper rolls 65 proceed through dryer 17 pulling the film 43 ′ through dryer 17 . As shown in FIG. 20 , upper film transfer arm member 62 exits dryer 17 at dryer exit 173 and comes into contact with a conduit 70 . Film sheet gripper rolls 65 turn to advance the film 43 ′ through conduit 70 and into scanner festoon box 71 . Scanner festoon box nip rollers 72 grasp a leading edge of film 43 ′ and force film 43 ′ into scanner festoon box 71 forming scanner film roll 435 . Scanner festoon box nip rollers 72 advance film 43 ′ into scanner festoon box 71 a specific distance equal to the pre-determined length of film 43 ′ so that the tail end of film 43 ′ remains nipped between scanner festoon box nip rollers 72 to go to the scanner.

In one embodiment of the present invention, film 43 ′ may be further processed by transporting the film 43 ′ to scanner 18 ′. As shown in FIG. 21 , scanner festoon box 71 rotates from an initial position (as shown in FIG. 20 ) to a secondary position so that the film 43 ′ may be fed to scanner 18 ′. Scanner 18 ′ may supply image data to computer 2000 or a remote computer (not shown) for further image processing. Following scanning, the film 43 ′ may be packaged as a film roll or as strips of film and returned to the customer along with scanned photographs in electronic format on an electronic disc if desired.

A number of commercially available films may be loaded according to the film-loading method described above, namely, wherein the film is separated from its corresponding film cartridge during processing. Suitable films, which may be used in this particular film-loading method, include, but are not limited to, 135 mm film. Desirably, 135 mm film is loaded into the photographic processor of the present invention according to this method.

The photographic processor of the present invention may be used to process one or more types of film. Suitable films include, but are not limited to, APS film, 135 mm film, etc. Desirably, the photographic processor of the present invention is designed to process APS film, 135 mm film, or both APS and 135 mm film. The photographic processor of the present invention may be categorized as a “single-roll” processing unit given that the circular processing drum only processes one roll of film at a time. However, it should be noted that the photographic processor of the present invention is capable of processing multiple rolls of film at a given time. For example, one roll of film may be in the circular processing drum, while a second roll of film is in the dryer and a third roll of film is in the scanner.

The photographic processor of the present invention may include other components other than those described in FIGS. 1-21 . For example, the photographic processor of the present invention may include an operator interface control panel operationally associated with computer 2000 (FIG. 1 ); a display screen; a control unit, wherein the control unit accepts input from a processor user, provides machine settings to one or more components of the processor based on the input of the user, and controls and executes a processing operation of the processor; and multiple film loading doors on an outer surface of the photographic processor housing. In one desired embodiment of the present invention, the photographic processor is used to process APS film and 135 mm film. In this embodiment, the photographic processor has two separate film loading doors on an outer surface of the photographic processor housing, one for an APS film cartridge and the other for a 135 mm film cartridge.

The photographic processor of the present invention may come in a variety of sizes depending on a number of factors including, but not limited to, the desired size of the circular processing drum, the desired storage capacity of the chemical delivery system, and the desired storage capacity of the waste collection reservoir. One of the benefits of the photographic processor of the present invention is the ability to place the photographic processor in a given room without occupying a large amount of space.

Another benefit of the photographic processor of the present invention is that the only requirement necessary to operate the photographic processor in a given room is a source of electricity. Since the photographic processor of the present invention can operate with working strength chemistry, the processor does not require a water source or drain for processing chemicals. A minimum amount of processing chemicals is needed to operate the photographic processor of the present invention due to the unique design of the circular processing drum. Further, a minimum amount of chemical waste is generated due to the design of the circular processing drum.

The circular processing drum of the photographic processor may vary in size depending on a number of factors including, but not limited to, the type of film processed, the length of the film processed, the width of the film processed, and the desired overall dimensions of the photographic processor. In one embodiment of the present invention, the length of the drum (i.e., the dimension perpendicular to the diameter of the drum) is substantially equal to the sum of (1) a thickness of the front wall of the drum, (2) a thickness of the back wall of the drum, and (3) a width of the strip of processible film. In a further embodiment of the present invention, the drum has a circumference, which is slightly greater than largest length of the roll film.

In one embodiment of the present invention, the photographic processor comprises (1) a circular processing drum having a front wall, a back wall, a side wall connecting the front wall to the back wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, wherein the diameter of the drum is greater than a length of the drum, which is measured along the axis of symmetry; (2) a disk positioned inside the drum in a plane parallel to both the front wall and the back wall, wherein the disk comprises one or more sets of disk teeth along an outer perimeter of the disk capable of interengaging with holes along a first edge of a sheet of processible film; and (3) a mechanism for rotating the disk while the drum is stationary. The mechanism for rotating the disk may be capable of rotating the disk and the drum simultaneously, or selectively rotating only the disk. The mechanism for rotating the disk may comprise a number of components including, but not limited to, a motor, a clutch, and a drive axis, wherein the drive axis is positioned along the axis of symmetry of the drum.

The circular processing drum and/or the disk may be rotated at a speed depending on a number of factors including, but not limited to, the type of film, the size of the circular processing drum, the desired amount of contact time between each of the one or more processing solutions and the roll of film, and the desired speed at which film is introduced into the circular processing drum.

In a further embodiment of the present invention, the photographic processor comprises a circular processing drum, wherein the circular processing drum comprises a disk having one or more sets of teeth. The one or more sets of teeth interengage with holes along the film to pull the film into the circular processing drum.

The photographic processor of the present invention may use any conventional chemical delivery system known in the art as long as the chemical delivery system is capable of inputting one or more processing fluids into the circular processing drum. Suitable chemical delivery systems deliver one or more processing fluids including, but not limited to, a developing solution, a bleach solution, a fix solution, a wash solution, or a combination thereof Desirably, the chemical delivery system comprises one or more separate containers for each of the processing fluids. For example, the chemical delivery system may comprise one or more separate containers containing a developing solution, one or more separate containers containing a bleach solution, one or more separate containers containing a fix solution, and one or more separate containers containing a wash solution. In one embodiment of the present invention, the chemical delivery system used in the photographic processor comprises one container of developing solution, one container of bleach solution, one container of fix solution, and at least one container of wash solution.

Desirably, the photographic processor of the present invention utilizes a chemical delivery system comprising “working strength” chemical solutions. As used herein, the term “working strength” is used to describe chemical solutions, which are prepackaged in separate containers at concentrations that do not require dilution with other solutions (i.e., a source of water), and can be used as is. Further, the photographic processor of the present invention may use any conventional chemical removal system to remove one or more processing fluids from the circular processing drum. Suitable chemical removal systems include, but are not limited to, a suction device or a drain 3000 ( FIG. 14 ) in the side wall of the circular processing drum. Typically, the chemical removal system further comprises a chemical waste reservoir 3002 ( FIG. 14 ) for storing one or more processing fluids removed from the drum. Desirably, the chemical waste reservoir is designed to contain all of the waste resulting from the use of all of the processing fluids contained in the chemical delivery system.

As discussed above, the photographic processor of the present invention uses a minimum amount of photoprocessing chemicals, and consequently generates a minimum amount of chemical waste.

The dryer of the invention should be capable of drying the processed film. The dryer may use air and/or radiant heat to dry the processed film. Desirably, the dryer has a capacity, which minimizes the amount of dwell time within the dryer. Also, it is preferable that the dryer be compact and positioned next to the circular processing drum as shown in FIGS. 1-2 above.

The photographic processor of the present invention may include a film-loading device, wherein the film loading device comprises one or more of the following components: (a) a film cartridge stabilizing bar for fixing a position of a film cartridge in a film cartridge loading area on an outer surface of the side wall; (b) a film cartridge door opening device; (c) a film cartridge spool turning device; (d) a festoon box for storing film removed from a film cartridge; (e) a cutting device for cutting film to separate the film from a film cartridge; and (f) a festoon box nip rollers for gripping film. Desirably, the film-loading device comprises all of the above components.

In a further desired embodiment of the present invention, the photographic processor comprises (1) a circular processing drum having a front wall, a back wall, a side wall connecting the front wall to the back wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, wherein the diameter of the drum is greater than a length of the drum, which is measured along the axis of symmetry of the drum; (2) a disk positioned inside the drum in a plane parallel to both the front wall and the back wall, wherein the disk comprises one or more sets of disk teeth along an outer perimeter of the disk capable of interengaging with holes along a an edge of a strip of processible film; and (3) a disk positioning device, wherein the disk positioning device moves the disk within the drum to change a distance between the disk and the front wall of the drum. The photographic processor may further comprise a mechanism (a) for rotating the disk and the drum simultaneously, and (b) for rotating the disk while the drum is stationary.

The present invention is further directed to a photographic process, wherein the process comprises the steps of: (1) loading a sheet of processible film into a circular processing drum, wherein the circular processing drum comprises (a) a front wall, (b) a back wall, (c) a side wall connecting the front wall to the back wall and extending around a perimeter of the drum, and (d) a horizontally extending axis of symmetry, wherein the drum has a diameter greater than a length of the drum, the length of the drum being measured along the axis of symmetry of the drum, and wherein the drum contains a disk positioned inside the drum in a plane parallel to both the front wall and the back wall, wherein the disk comprises one or more sets of disk teeth along an outer perimeter of the disk capable of interengaging with holes along a first edge of the sheet of processible film; (2) contacting the sheet of processible film with one or more processing fluids in the circular processing drum; (3) rotating the circular processing drum along the axis of symmetry for a period of time; (4) removing the one or more processing fluids from the circular processing drum; and (5) drying the film. In the above method, the loading step may comprise one or more of the following steps: (i) feeding the sheet of processible film into the circular processing drum through a film-loading slot in the side wall of the drum; (ii) nipping the sheet of processible film to move the sheet of processible film into contact with the one or more sets of disk teeth along the disk; and (iii) rotating the disk while the drum remains stationary to advance the sheet of processible film into the circular processing drum.

The photographic process of the present invention may comprise contacting a strip of film with one or more processing fluids selected from a developing solution, a bleach solution, a fix solution, a wash solution, or a combination thereof. In one embodiment, the photographic process comprises a contacting step, which comprises (i) inputting a developing solution into the circular processing drum; (ii) inputting a bleach solution into the circular processing drum; (iii) inputting a fix solution into the circular processing drum; and (iv) inputting at least one wash solution into the circular processing drum. The contacting step of the process may further comprise separate removal steps following a washing solution input step. As an alternative, the process may comprise inputting a developing solution into the drum; inputting a fix solution into the drum; inputting a bleach solution into the drum; and inputting at least one wash solution into the drum.

The photographic process of the present invention may further comprise a rotating step, wherein the rotating step comprises rotating the drum and the disk simultaneously. The drum and the disk may be simultaneously rotated after each processing solution input step for a period of time in order to insure a desired amount of contact between each processing solution and the film.

The photographic process of the present invention may comprise a series of processing steps, wherein the film remains intact with its corresponding film cartridge (for example, APS film). In other embodiments, the photographic process of the present invention comprises removing the processible film from a film cartridge (i.e. 35 mm film), and cutting the processible film to separate the processible film from the film cartridge. When the film is to remain intact with its film cartridge (i.e. APS film), the photographic process of the present invention may comprise one or more of the following film loading steps: (a) positioning a film cartridge containing the strip of processible film in a film cartridge loading area on an outer surface of the side wall; (b) applying a film cartridge stabilizing bar to an upper surface of the film cartridge to secure the film cartridge; (c) opening a door of the film cartridge; and (d) turning a spool within the film cartridge. When the film is to be separated from its film cartridge (i.e. 35 mm film), the photographic process of the present invention may comprise one or more of the following film loading steps: (a) positioning a film cartridge containing the strip of processible film in a film cartridge loading area adjacent to a festoon box; (b) pulling a tongue on the film from the film cartridge using, for example, a film extraction tool; (c) engaging perforations on the film on a sprocket wheel; (d) transferring the film from the film cartridge to the festoon box to form a roll of film; wherein a last exposure on the film is on an outer portion of the roll of film; and (e) cutting the film to separate the film from the film cartridge.

In a further embodiment, the present invention is directed to a photographic process which comprises moving a disk within a circular processing drum along an axis of symmetry of the drum to change a distance between the disk and a wall, such as the front wall, of the drum. In this embodiment, the photographic process is capable of processing different types of film using the same circular processing drum by adjusting the position of the disk within the circular processing drum.

The circular processing drum up to now has be described as having a disk which is movable along its rotational axis so as to accommodate different types of photographic film. However, the present invention is not limited to such an arrangement. In a further embodiment of the present invention, the processor can include a circular processing drum which is adjustable in width.

FIGS. 22A-22C illustrate a first embodiment of a circular processing drum with an adjustable width. With reference to FIG. 22A , a circular processing drum 14 a is shown. Circular processing drum 14 a is similar to circular processing drum 14 illustrated in FIG. 1 , with respect to including an inlet for processing photographic film, and having a rotatable disk 30 therein, for conveying photographic film through the circular processing drum. As shown in FIGS. 22A-22C , circular processing drum 14 a includes a first wall 14 a ′, a second wall 14 a ″ and a perimeter wall member 14 a ′″ that essentially connects the first wall to the second wall and extends around a perimeter of drum 14 a. Processing drum 14 a further includes a circular film path 6007 , a portion of which is shown in FIG. 22C , and which is similar to the circular film path described with respect to the embodiments of FIGS. 1-21 . As shown in FIG. 22C , perimeter wall member 14 a ′″ includes a first portion 6000 which extends from first wall member 14 a ′ and a second portion 6001 which extends from second wall member 14 a ″. Each of portions 6000 and 6001 overlap each other such that a distance between the first and second walls 14 a ′ and 14 a ″ can be adjustable by changing an amount of the overlap between first and second portions 6000 and 6001 of perimeter wall member 14 a ′″. In order to seal drum 14 a, a seal and preferably first and second known ring seals 6010 a and 6010 b are placed between first and second portions 6000 and 6001 .

Therefore, in order to accommodate, for example, a film of a first format or width within film path 6007 , overlap portions 6000 , 6001 can be adjusted to minimize the amount of overlap between them, and therefore, widen or increase the width of processing drum 14 a. More specifically, by minimizing the amount of overlap between portions 6000 and 6001 , the distance between first wall member 14 a ′ and second wall member 14 a ″ is increased from the position illustrated in FIG. 22B to the position illustrated in FIG. 22 C. As shown in FIG. 22C , disk 30 which includes teeth 35 for engaging perforations in the film, is adjacent to second wall 14 a ″. In a preferred embodiment, second wall 14 a ″ is a fixed wall, such that first wall 14 a ′ is movable towards and away from fixed second wall 14 a ″ by changing the amount of overlap between portions 6000 and 6001 .

With this arrangement, when it is desired to process film of a first type or width, for example, 35 mm film, the distance between the first and second walls 14 a ′ and 14 a ″ is adjusted to accommodate the first type of film within film path 6007 . Thereafter, the film is inserted into the processing drum in a similar manner as described with respect to the embodiment of FIGS. 1-21 and processed accordingly.

When it is desired to process a second type of film such as APS film which is smaller in width than 35 mm film, the amount of overlap between portions 6000 and 6001 is increased, so as to decrease the distance between first wall member 14 a ′ and second wall member 14 a ″. With this arrangement, the width of film path 6007 is decreased, in accordance with the width of APS film. Thereafter, the APS film is inserted and processed in a similar manner as described with reference to FIGS. 1-21 .

The advantage of such an embodiment is that the processing drum and specifically, the width of the processing drum is optimized to match the width of the film which is to be processed. Additionally, the volume of the processing drum is also adjusted to match the type of film. For example, when APS film is processed within processing drum 14 a, the distance between first and second walls 14 a ′ and 14 a ″ is decreased. This decreases the volume within the processing drum 14 a and thus, requires less solution than would be required when a drum having a fixed width to accommodate larger width film is used. By optimizing the amount of solution used for each type of film, unnecessary waste of solution is prevented.

FIGS. 23A-23C illustrate a further embodiment of a photographic circular processing drum having an adjustable width in accordance with the present invention. Circular processing drum 14 b as illustrated in FIGS. 23A-23C is similar to the embodiment illustrated in FIGS. 22A-22C , however, rather than having overlapping portions, circular processing drum 14 b of FIGS. 23A-23C has movable bellows. More specifically, as illustrated in FIGS. 23A-23C , processing drum 14 b includes a first wall 14 b ′, a second wall 14 b ″, and a perimeter wall 14 b ′″ which extends around the perimeter of the drum. Circular processing drum 14 b further comprises a circular film path 6007 similar to the embodiment of FIGS. 22A-22C . As illustrated in FIG. 23C , perimeter wall member 14 b ′″ of circular processing drum 14 b comprises an adjustable bellows 6003 which is basically adjusted to change a distance between first wall 14 b ′ and the second wall 14 b ″ and thus, accommodate different types of film within processing drum 14 b. Like the embodiment of FIGS. 22A-22C , disk 30 is positioned within circular processing drum 14 b adjacent to second wall 14 b ″. In a preferred embodiment of the present invention, second wall member 14 b ″ is fixed while the first wall member 14 b ′ is movable.

With the embodiment of FIGS. 23A-23C , when it is desired to process a first type of film of a first width such as for example, 35 mm film, adjustable bellows 6003 is manipulated to adjust the distance between first wall 14 b ′ and second wall 14 b ″, so as to adjust film path 6007 to accommodate 35 mm film as shown in FIG. 23 C. When it is desired to, for example, process a second type of film of a different or smaller width than 35 mm film, such APS film, bellows 6003 is manipulated to shorten the distance between first wall 14 b ′ and second wall 14 b ″ as illustrated in FIG. 23 B. This adjusts film path 6007 to accommodate APS film within film path 6007 . Like the first embodiment, in the embodiment FIGS. 23A-23C , the volume of drum 14 b is optimized, so as to permit the use of less solution when the width of processing drum 14 b is minimized to, for example, process APS film.

FIGS. 24A-24C illustrate a mechanism 7000 for adjusting the width of the drum using the bellows embodiment as an example. Mechanism 7000 can include a rod or shaft 7002 attached to, for example, movable wall 14 b ′ of the embodiment of FIGS. 23A-23C or movable wall 14 a ′ of the embodiment of FIGS. 22A-22C . A known solenoid can be used to actuate mechanism 7000 . Using the bellows embodiment as an example, mechanism 7000 can be actuated by the solenoid to move wall 14 b ′ away ( FIG. 24C ) or towards ( FIG. 24B ) fixed wall member 14 b ″ in accordance with the type of film to be processed. It is noted that actuator 7000 and its relationship to processing drum 14 a or 14 b can be similar to the arrangement illustrated in FIG. 9A for moving the disk 30 . More specifically, the movable wall 14 a ′ or 14 b ′ can be moved by shaft 7002 in a similar manner that disk 30 is moved by shaft 261 shown in FIG. 9A , by using, for example, pivotable arm 262 also shown in FIG. 9A or a solenoid. In this arrangement, shaft 7002 is linearly movable and would extend through a bore in wall 14 b ″ and corresponding bore in disk 31 . Shaft 7002 would then be connected to movable wall 14 b ′ to move wall 14 b ′ when shaft 7002 is moved.

While the specification has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. Accordingly, the scope of the present invention should be assessed as that of the appended claims and any equivalents thereto.

Claims

1. A photographic processor comprising:an adjustable circular processing drum assembly comprising a first wall, a second wall, a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, said circular processing drum assembly further comprising a circular film path for film to be processed therein, said perimeter wall member comprising a first portion attached to said first wall and a second portion which overlaps said first portion and is attached to said second wall, wherein a distance between said first and second walls is adjustable by changing an amount of overlap between said first and second portions of said perimeter wall member between a first overlap amount to accommodate a first type of film in said film path and a second overlap amount which is less that the first overlap amount to accommodate a second type of film in said film path; and a disk positioned inside said processing drum in a plane parallel to both the first wall and the second wall, said disk comprising one or more set of disk teeth along an outer perimeter of the disk for interengaging with holes along an edge of the first or second type of film.

2. A photographic processor according to claim 1, further comprising:a mechanism for moving one of said first and second walls with respect to the other of said first and second walls to change the distance between the first and second walls.

3. A photographic processor according to claim 1, wherein one of said first and second walls is fixed and the other of said first and second walls is movable, said disk being positioned adjacent to said fixed wall.

4. A photographic processor according to claim 1, wherein said first type of film is 35 mm film and said second type of film is APS film.

5. A photographic processor comprising:an adjustable circular processing drum assembly comprising a first wall, a second wall, a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, said circular processing drum assembly further comprising a circular film path for film to be processed therein, said perimeter wall member comprising an adjustable bellows which changes a distance between said first and second walls between a first distance to accommodate a first type of film in said film path and a second distance which is less that the first distance to accommodate a second type of film in said film path; and a disk positioned inside said processing drum in a plane parallel to both the first wall and the second wall, said disk comprising one or more set of disk teeth along an outer perimeter of the disk for interengaging with holes along an edge of the first or second type of film.

6. A photographic processor according to claim 5, further comprising:a mechanism for moving one of said first and second walls with respect to the other of said first and second walls to change the distance between the first and second walls.

7. A photographic processor according to claim 5, wherein one of said first and second walls is fixed and the other of said first and second walls is movable, said disk being positioned adjacent to said fixed wall.

8. A photographic processor according to claim 5, wherein said first type of film is 35 mm film and said second type of film is APS film.

9. A photographic processor comprising:an adjustable circular processing drum assembly comprising a first wall, a second wall, a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, said circular drum assembly further comprising a circular film path for film to be processed therein; a mechanism for adjusting a distance between said first and second walls between a first distance for accommodating a first type of film in said film path and a second distance which is smaller than said first distance for accommodating a second type of film in said film path; and a disk positioned inside said processing drum in a plane parallel to both the first wall and the second wall, said disk comprising one or more set of disk teeth along an outer perimeter of the disk for interengaging with holes along an edge of the first or second type of film.

10. A photographic processor according to claim 9, wherein said first type of film is 35 mm film and said second type of film is APS film.

11. A method of processing a photographic film, the method comprising the steps of:changing a width of an adjustable circular processing drum to a first width in accordance with a first type of film to be processed to accommodate the first type of film; inserting the first type of film into the adjustable circular processing drum; and supplying and discharging processing solution into and from the adjustable processing drum to process the first type of film.

12. A method according to claim 11, comprising the further step of:removing the processed first type of film from the adjustable processing drum.

13. A method according to claim 12, comprising the further steps of:changing a width of said adjustable circular processing drum to a second width when a second type of film which is different from said first type of film is to be processed; inserting the second type of film into the adjustable circular processing drum; and supplying and discharging processing solution into and from the adjustable processing drum to process the second type of film.

14. A method according to claim 13, comprising the further step of:removing the processed second type of film from the adjustable processing drum.

15. A method of processing a photographic film, the method comprising the steps of:adjusting a width of a circular processing drum between at least first and second widths in accordance with a film to be processed to accommodate the film in a film path in said circular processing drum; inserting the film into the circular processing drum; and supplying and discharging processing solution into and from the processing drum to process the film.

16. A method according to claim 15, comprising the further step of:removing the processed film from the circular processing drum.

17. A method according to claim 15, wherein said circular processing drum comprises a first wall, a second wall, a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the drum, and a horizontally extending axis of symmetry, said perimeter wall member comprising an adjustable bellows, such that said adjusting step comprises changing a distance between said first and second walls through said bellows.

18. A method according to claim 15, wherein said circular processing drum comprises a first wall, a second wall, and a perimeter wall member connecting the first wall to the second wall and extending around a perimeter of the circular processing drum, said perimeter wall member comprising a first portion attached to said first wall and a second portion which overlaps said first portion and is attached to said second wall, wherein said adjusting step comprises changing an amount of overlap between said first and second walls.