Method and apparatus for cleaning photo film

Abstract: A method of, and an apparatus for, cleaning a web of photo film during the manufacture is disclosed wherein the web of photo film is transported in its lengthwise direction, and a cleaning tape made of felt is pressed onto an entire area or a side portion of a surface of the photo film or a side edge of the photo film, while the photo film and the cleaning tape are transported in opposite directions.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of, and an apparatus for, cleaning photo film, especially for photo film having a magnetic recording layer on a reverse surface to an emulsion surface. More particularly, the present invention relates to a method of, and an apparatus for, cleaning photo film during the manufacture. 2. Background Arts A new type photo film cartridge has been developped and disclosed, for example, in U.S.P. Nos. 4,834,306 and 4,832,275, and JPA 3-37645 (U.S.P. No. 5,271,577), wherein an entire length of photo filmstrip is wound into a cartridge shell before and after use, and a film leader is advanced out of the cartridge shell in response to unwinding rotation of a spool of the cartridge shell. This new type photo film cartridge is easy to load in the camera, easy to handle and thus improves work efficiency during the photographic processing. It is also known in the art to provide a transparent magnetic recording layer on the new type photo filmstrip so that photographic data or print data may be magnetically recorded on the photo filmstrip in association with respective frames. When manufacturing the photo filmstrip, an emulsion layer is applied on an obverse surface of a wider web of base film, and the magnetic layer is applied on a reverse surface of the wider web. Thereafter, the wider web is slit into narrower webs of a constant width. The narrower web is perforated and cut into individual filmstrips of predetermined lengths, each of which is then wound into the cartridge shell. As a result of the slitting, particles of film or swarf are produced from the cut edges of the narrower webs. The film swarf and dust floating in the factory can be put on the photo filmstrip. If the swarf and dust are put on the magnetic recording layer, the swarf and dust accumulate on a magnetic head, thereby deteriorating sensitivity of the head and the signal frequency characteristics. This may result in writing errors or reading errors. The swarf or dust on the emulsion surface results in black spots in the images exposed on the photo filmstrip. The swarf or dust on either surface can result black spots in the photo-prints since the printing light transmits through the photo filmstrip. US Patent No. 4,858,265 discloses an apparatus for cleaning the edges of a magnetic tape cut into final-product widths from a wide raw material web. The apparatus includes an air bearing guide for floating the magnetic tape as it is transported thereon, a cleaning device positioned at a side of the guide, and a magnet device for urging the edge of the tape into close contact with the cleaning device. Document GB 1453600 A shows a device for continuously cleaning a surface sensitive web by a ribbon of fibrous non-woven material which is pressed against the surface sensitive web for cleaning the surface thereof with both the web and the ribbon being transported in the longitudinal direction, while being contacted at a cleaning location. However, according to GB 1453600, two cleaning tapes are applied to clean both the front and back surfaces of the web. Since the particles are removed under suction according to GB 1453600, there is no fear of scratching the surface of the web, which implies that the web is cleaned in the image recording areas where the photosensitive emulsion layer is provided. Document US 3945079 relates to a laminated photographic film cleaning fabric which is applied to the film from both sides to clean substantially the entire film surface. Document US 4145231 relates to a film-driven film cleaner which cleans a film from both sides on substantially its entire surface. Document DE 4026616 A1 teaches a device for cleaning and removing humidity from a web material containing a blowing device. This document does not show the feature of cleaning the film by tapes. Document GB 1282375 relates to a method and apparatus for removing dust from the surface of a running web and contrives to clean the surface by blowing off particles rather than using tapes. Document JP 7212650 A teaches to use a brush in contact with a film to remove static on the film and to blow away dust from the film by use of air nozzles. The use of tapes to clean a film is not taught. SUMMARY OF THE INVENTION In view of the foregoing, an object of the present invention is to provide a method of cleaning photo film from dust or swarf produced during the manufacture, insuring protection against scratches on the frame-recording area, and an apparatus therefor. To achieve the above object, the present invention provides a method of cleaning a web of photo film as defined in claim 1. To achieve the above effects, the present invention further provides an apparatus for cleaning a web of photo film as defined in claim 5. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments when read in connection with the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, wherein like reference numerals designate like or corresponding parts throughout the several views, and wherein: Figure 1 is an explanatory sectional view of photo film having a magnetic recording layer; Figure 2 is an explanatory view of the first stage of a film manufacturing line; Figure 3 is an explanatory view of the last stage of the film manufacturing line including a film cleaning process according to the invention; Figure 4 is a perspective view of a first type cleaning device according to an embodiment of the invention, for cleaning side portions of a surface of the photo film; Figure 5 is a sectional view of a cleaning head of the first type cleaning device; Figure 6 is an explanatory top plan view of a second type cleaning device according to a further embodiment of the invention, for cleaning side edges of the photo film; Figure 7 is a sectional view of essential parts of the second type cleaning device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, the new type photo film 10 is constituted of a base film 11, a photosensitive emulsion layer 12 and a transparent magnetic layer 13. The emulsion layer 12 and the magnetic layer 13 are applied on the opposite surfaces of the base film 11. The magnetic layer 13 permits recording photographic data or print data thereon through a magnetic head provided in a camera, a film inspector, a printer or the like. The base film 11 is formed from a transparent synthetic resin material, e.g., cellulose triacetate (TAC), polyethylene terephthalate (PET) and annealed polyethylene naphthalate (A-PEN). Referring to FIG. 2, in a base film producer 14, the material is melded or solved to be formed into a highly transparent web 11 having a constant thickness and a larger width than photo filmstrips to be manufactured. While the web of base film 11 is transported in a lengthwise direction at a constant speed, a magnetic layer coating device 15 coats one surface of the base film 11 with the magnetic layer 13 of a constant thickness. After being coated with the magnetic layer 13 and dried through a drier 16, the web of base film 11 is coiled into a roll 11a. The roll 11a of base film 11 is sent to a photosensitive emulsion applying process 17 which is executed in a dark room. The base film 11 is withdrawn from the roll 11a, and transported at a constant speed through an emulsion coating device 18, which applies the emulsion layer 12 on the other surface of the base film 11 from the magnetic layer 13. As well known in the art, the emulsion layer 12 is constituted of many coats of different kinds emulsions which vary depending upon the film type such as the film speed, the discrimination between the negative and the positive or between color film or black-and-white film. After the emulsion layer 12 is dried through a drier 19, a wider web 10a of photo film is transported to a slitter 20. The slitter 20 slits the wider web 10a into a plurality of webs 10b of a predetermined width. The webs 10b of photo film are wound up around respective reels 21. The reel 21 with the photo film web 10b is send to a film cartridge manufacturing process 22, as shown in FIG. 3. A process controller 23 controls the film cartridge manufacturing process 22 such that the photo film web 10b is formed into individual photo filmstrips 10c in accordance with a film size which is entered through a size input device 24. The film size includes the number of available exposures in addition to the above mentioned film type, since the length of the individual filmstrip varies depending upon the available exposure number. The photo film web 10b is transported from the reel 21 to a perforator 25 through a not-shown accumulator or buffer, because the photo film web 10b intermittently pauses for a while the perforator 25 forms a series of perforations along a limited length of the photo film web 10b, so it is necessary to absorb the speed difference between the intermittent transportation through the perforator 25 and the supply from the reel 21. The length of making a series of perforations at one time is determined according to the film size. After being perforated, the photo film web 10b is transported by a suction drum 29 to a measuring feeder 26. The measuring feeder 26 transport the photo film web 10b by a length that is also determined according to the film size. Then a trimmer 27 cuts the photo film web 10b into the filmstrip 10c of a length defined by the film size. The measuring feeder 26 may be a suction drum. While the photo film web 10b is transported by the measuring feeder 26, a side printer 28 prints latent images of film size code, frame serial numbers, and ID code representative of a manufacture number or the like on one or both sides of the photo film web 10b. The trimmer 27 simultaneously shapes a trailing end of the filmstrip 10c made presently, and a leading end of a filmstrip to be made next, in the transporting direction of the photo film web 10b. In this embodiment, the leading end of each filmstrip 10c in the transporting direction is provided with holes to secure the filmstrip to a spool of each cartridge shell, though the holes are not shown in the drawings. In other words, the trailing end of each filmstrip 10c in the transporting direction will be a leader when the filmstrip 10c is coiled into a cartridge shell 34 in a film winding device 30. There are a plurality of film winding devices 30, and a film distributer 31 distributes the filmstrips 10c seriatim to the respective film winding devices 30 through passageways 37, to permit concurrently winding a plurality of filmstrips 10c. The cartridge shells 34 are supplied to the film winding device 30 from a cartridge supplier 32 through a cartridge distributer 33. Each cartridge shell 34 is provided with the same ID code as one of the filmstrips 10c has as the latent image. The film distributer 31 and the cartridge distributer 33 are controlled such that those filmstrip 10c and cartridge shell 34 having the same ID code are set in the same film winding device 30. The film winding device 30 collates the ID code of the filmstrip 10c with that of the cartridge shell 34 and, if the ID codes are identical, winds the filmstrip 10c into the cartridge shell 34. Subsequent photo film cartridges are aligned in a line at a junction 35, to be sent to a shipment process 36. As described above, the film winding device 30 secures the filmstrip 10c to the spool of the cartridge shell at the leading end in the transporting direction, and winds the filmstrip 10c into the cartridge shell 34 until the trailing end is entirely located inside the cartridge shell 34. The trailing end, i.e. the leader, of the filmstrip 10c is advanced to the outside of the cartridge shell 34 when the spool is rotated in an unwinding direction. In the embodiment shown in FIG. 3, a film cleaning apparatus 38 is disposed behind the perforator 25 before the suction drum 29. Thereby the swarf or chips produced by perforating are reliably put away from the photo film 10b. However, since the continuous web of photo film 10b is transported intermittently through the perforator 25, cleaning during the intermittent transportation can result unevenness. Therefore it is desirable to dispose an accumulator or a loop between the perforator 25 and the cleaning apparatus 38, so as to permit transporting the photo film 10b continuously at a constant speed through the cleaning apparatus 38. It is alternatively possible to locate the cleaning apparatus 38 behind the reel 21 before the not-shown accumulator, where the photo film 10b is supplied from the reel 21 at a constant speed. It is also possible to locate the cleaning step after the slitting step by the slitter 20 before winding the photo film 10b on the reels 21. The film cleaning apparatus 38 is constituted of three cleaning devices for cleaning the magnetic layer surface 13, the emulsion surface 12, and opposite side edges of the filmstrip 10c. Each cleaning device uses a cleaning tape or tapes to wipe off the dust and swarf. As the emulsion layer surface 12 is to record image frames, it is very important not to scratch the frame recording area of the emulsion surface 12. To ensure protection against the scratches on the frame recording area by the cleaning, a first type cleaning device 38b according to the invention as shown in FIG. 4 is preferable, which cleans side portions of the emulsion surface 12 outside the frame recording area. This cleaning device 38b uses a pair of cleaning tapes 40a and 40b having a width corresponding to the side portion of the emulsion surface. The cleaning tapes 40a and 40b are wound around reels 53a and 53b which are coaxially fit on a driven shaft 54, and are spaced in the axial direction. After passing a cleaning head 55, the cleaning tapes 40a and 40b are taken up by reels 56 and 57 which are fit on different drive shafts 58 and 59, respectively. The drive shafts 58 and 59 are rotated by a motor 47 through a speed reduction device 46. The filmstrip 10c is transported in a direction through guide rollers 49 and 50, while the cleaning tapes 40a and 40b are transported in the opposite direction. As shown in FIG 5 the cleaning head 55 has a convex face surface 55a which is formed with a stepped recession 55b whose length in a crosswise direction of the filmstrip 10c is slightly more than the width of the filmstrip 10c. The cleaning tapes 40a and 40b are guided along opposite stepped edges of the recession 55b, while the filmstrip 10c is guided such that the side portions of the filmstrip 10c slide on the cleaning tapes 40a and 40b. In this way, the cleaning tapes 40a and 40b do not contact the frame recording area of the filmstrip 10c. To suck up the dust into the cleaning tapes 40a and 40b, suction holes 55c are preferably formed through those zones of the recession 55b on which the cleaning tapes 40a and 40b slide, so that the frame recording area of the filmstrip 10c may not contact the cleaning head 55. FIG. 6 shows a second type cleaning device 38c that cleans the side edges of the filmstrip 10c, wherein a pair of cleaning tapes 40c and 40d are transported along the side edges of the filmstrip 10c from supply reels 60 and 61 to take-up reels 62 and 63, respectively. As shown in FIG.5 a pair of guide rails 64 and 65 are disposed along the opposite lateral sides of the filmstrip 10c, to guide the cleaning tapes 40c and 40d such that the tapes 40c and 40d are oriented vertically to the filmstrip 10c, and are pressed onto the side edges of the filmstrip 10c. The guide rails 64 and 65 have a channel 64a or 65a, and the cleaning tape 40c or 40d slides along the channel 64a or 65a of the guide rail 64 or 65, respectively. The filmstrip 10c can remove from either of the cleaning tapes 40c and 40d for some reasons such as curling. To ensure the contact between the cleaning tapes 40c and 40d and the side edges of the filmstrip 10c, one guide rail 64 is mounted to be movable in the crosswise direction of the filmstrip 10c, and is urged by a spring 66 toward the other guide rail 65, whereas the other guide rail 65 is mounted stationary. It is desirable to make the force of the spring 66 adjustable. The guide rails 64 and 65 may have suction holes. It is possible to replace either of the guide rails 64 and 65 by a pair of guide rollers spaced from each other along the side edge. It is possible to omit the suction holes 43b or 55c from the cleaning head 43 or 55. Although the present invention has been described with respect to photo film with transparent magnetic layer, the cleaning method and apparatus of the present invention are applicable to those photo film having no magnetic layer. Thus, the present invention should not be limited to the above described embodiments but, on the contrary, various modification may be possible to those skilled in the art without departing from the scope of claims attached hereto.

Claims: A method of cleaning a web of photo film comprising the steps of: transporting the web (10b, 10c) of photo film in a lengthwise direction thereof; transporting a pair of cleaning tapes (40a, 40b) in a direction parallel to the lengthwise direction of the photo film; and pressing the cleaning tapes onto the photographic film, characterized in that said pressing step is performed so as to simultaneously press said pair of cleaning tapes only outside a frame recording area of a photosensitive emulsion surface (12) of said photo film. A method as claimed in claim 1, wherein the cleaning tape is transported in the opposite direction to the photo film. A method as claimed in claim 1, further comprising the steps of guiding the cleaning tapes in a vertical orientation to the photo film. A method as claimed in claim 1, wherein said cleaning tapes are pressed face to face onto side portions of said film. An apparatus for cleaning a web of photo film comprising: a transporting device (49, 50) for transporting the web of photo film in a lengthwise direction thereof; a second transporting device (53a, 53b, 54, 56 to 59) for transporting a pair of cleaning tapes (40a, 40b) in a direction parallel to the lengthwise direction of the photo film; and a device for pressing the cleaning tapes onto the photographic film, characterized in that said pressing device is adapted to simultaneously press the tapes onto said film only outside frame recording areas of a photosensitive emulsion surface of the photo film. An apparatus as. claimed in claim 5, wherein the cleaning tapes are made of a porous material, preferably felt. An apparatus as claimed in claim 5, wherein the pressing device comprises a head member (55) having a face surface (55a) facing the cleaning tapes, and a plurality of suction holes formed through those zones of the face surface on which the cleaning tapes slide, to suck the side portions of the photo film through the cleaning tapes. An apparatus as claimed in claim 7, wherein the face surface is formed with a stepped recession (55c) whose length in a crosswise direction of the web of photo film is slightly more than a width of the web of photo film, and wherein the cleaning tapes (40a, 40b) are guided along opposite stepped edges of the recession that extend parallel to the lengthwise direction of the photo film. An apparatus as claimed in claim 5, wherein the second transporting device transports the cleaning tapes in the opposite direction to the photo film. An apparatus as claimed in claim 5, further comprising a device (64, 65) for pressing the cleaning tapes onto side edges of the photo film. An apparatus as claimed in claim 10, further comprising guide members (64a, 65a) for guiding the cleaning tapes in an orientation vertical to the photo film.

Inventors: KUBOTA MASAYUKI, TSUNEKAWA YUZO, KUBOTA, MASAYUKI, TSUNEKAWA, YUZO
Applicants: FUJI PHOTO FILM CO LTD, FUJI PHOTO FILM CO., LTD.
Application year: 1997
Main classification: G03C11
IPC codes: G03C1, G03C11