The present invention relates to a photo-thermographic recording apparatus for forming an image onto a photo-thermographic film by developing and visualizing a latent image formed thereon by heating the film.
In conventional medical imagers or photo-thermographic recording apparatuses, the medical imager is structured so that each size of photo-thermographic films (film will be used hereinafter) of 17×14 inch size, 14×14 inch size and 11×14 inch size are processed in a single photo-thermographic recording apparatus by conveying the film in the direction being a right angle against 14 inch width direction of the film. And with regard to another size, for example, an 8×10 inch size film is processed by a dedicated photo-thermographic recording apparatus. There are no big differences between them, whichever the system is used, from the viewpoint of functions, performances and cost of the apparatus.
However, in recent years, needed is an imager capable of processing of 8×10 inch size film, etc., which has different sizes in a width direction and a longitudinal direction from that of the films described above, such as 17×14 inch size, 14×14 inch size and 11×14 inch, in a single apparatus.
In an imager employing a photo-thermographic process, there are problems specifically associated with photo-thermographic developing device which will be described below. Namely, in a photo-thermographic process, in case that a film is conveyed as the film is sandwiched by a heating drum and a plurality of opposed rollers as a means for heating and conveying the film, an elastic layer of silicon rubber, etc., is provided on the surface of a heating member to realize uniform contact between the film and the heating drum and the opposed rollers, and the uniform surface temperature of the heating drum, which is disclosed in Japanese Patent Application Open to Public Inspection No. H10-500497.
However, organic acid and/or higher fatty acid included in the photo-thermographic film volatilized by the heat drifts around the elastic layer, attacks the silicon layer and harms the cross-linking of silicon rubber as the photo-thermographic film is processed. Also, volatilized organic acid, etc., coheres and adheres onto the surface of the heating drum. Once these cohered substances form a film footmark on the surface of the heating drum, an image may be affected by these cohered substances.
Further, cutting dross from the leading edge, rear edge and side edges of the cutting surface of the film and emulsion flakes, etc., are adhered onto the heating drum and the opposed rollers. These substances harm the uniform contact or uniform thermal transmission and resulting density unevenness of the image.
Further more, a portion of the elastic layer where the film passes swells as the heating drum itself repeats heating and cooling. As a result, a crack starts to appear on the surface of the elastic layer and the crack is transferred onto the film. This phenomenon occurs since the contact condition between the heating drum and the film becomes uneven and the heat transmission across the heating drum becomes uneven. In case that a film conveyance pass in a thermal developing device is always unchanged, for example, 14 inch size, the image is formed without seriously affected and the heating drum properly operates until cracks occurs in the elastic layer even though 17×14 inch size film, 14×14 inch size film and 11×14 inch size film are processed.
However, in case that another size film which is different from 14 inch size film is processed in a single imager (a photo-thermographic recording apparatus), there has been problems that a swelling mark and/or a passing mark corresponding to the edge of the film occurs at a portion being different from 14 inch width-edge. Accordingly, when the maximum size film is processed, these marks described above appear in the image on the film.
In order to prevent those problems described above, cleaning was needed. However since a cleaning cycle becomes frequent and maintenance time and cost increase, it is not preferable to do so.
Japanese Patent Application Open to Public Inspection No. H11-65070 discloses an image recording apparatus which delays the conveyance of the new film being inputted into a thermal developing device, when the new film is a different size form a previous film, by holding the new size film for a predetermined time period. It discloses an image recording apparatus designed to unify the surface temperature of the heating drum by continuing rotation and heating of the heating drum by a heater while holding the new size film which will be inputted into the thermal developing device. However, it is not an image recording apparatus capable of removing the problems associated with the heating process of the photo-thermographic film.
It also discloses a photo-thermographic recording apparatus for removing dirt adhering onto a heating drum and preventing doted image defects by providing a dirt removing means having stickiness on the surface of the dirt removing means to be in contact with the heating drum, when visualizing an image formed on a photo-thermographic film by sandwiching the film between the heating drum and an endless belt in a heating device. However, it does not disclose the affection of foreign matter to the opposed roller and the cleaning of the opposed roller which is an auxiliary means operating together with the heating device.
An object of the present invention is to provide a photo-thermographic recording apparatus for securing uniform contact and heat transmission between an opposed roller and a heat drum and to prevent foreign matters, such as cohered and adhered fatty acid volatized from cutting dross and emulsion flakes from an adjacent portion of a film cutting surface, which are adhered and solidified on the opposed roller from growing, when conducting a thermal developing process of a plurality of sizes of photo-thermographic films to solve the problems of prior art described above.
(1) In accordance with one aspect of the present invention, a photo-thermographic recording apparatus comprises a film loading device capable, of loading a sheet type photo-thermographic film, a conveyance device for conveying the photo-thermographic film from the film loading device, an exposing, device for forming a latent image corresponding to an image signal onto the sheet type photo-thermographic film conveyed by the conveyance device and a thermal developing device for visualizing the latent image formed onto the sheet type photo-thermographic film while heating the sheet type photo-thermographic, the thermal developing device including a heating device therein and a plurality of opposed rollers arranged opposite to the heating device so as to press the sheet type photo-thermographic film onto the thermal developing device, the plurality of opposed roller being capable of contacting a predetermined portion of the thermal developing device, wherein the plurality of opposed rollers is structured not to contact the heating device in an area adjacent to both edges of the sheet type photo-thermographic film being in contact with the heating device.
(2) In accordance with another aspect of the present invention, the photo-thermographic recording apparatus of (1), wherein the plurality of opposed rollers is structured not to contact portions adjacent both sides of the heating device which the photo-thermographic film contacts and the exposing device corrects an exposing amount of an area where the sheet type photo-thermographic film is in contact with the heating device and not in contact with the plurality of opposed rollers.
According to the photo-thermographic recording apparatus, since each opposed roller does not contact the area adjacent to both edges of the sheet type photo-thermographic film which is in contact with the heating device, it becomes difficult for cutting dross and emulsion flakes originated from the film edges to adhere on the opposed rollers. Consequently, foreign matter growth based on adhesion of the cutting dross and emulsion flakes onto the opposed rollers is prevented. Accordingly uniform contact between opposed rollers and a heating drum can be obtained. Also, since foreign matter growth is prevented, the maintenance cycle of the apparatus can be prolonged. Further, since the area where the film is not in contact with the opposed rollers does not have heat transmission from the opposed rollers, it is anticipated that there is a possibility that optical density is lowered. However, heat deficit can be compensated by correction of an exposure amount and the optical density of film finishing can be kept constant.
(3) In accordance with another aspect of the present invention, the photo-thermographic recording apparatus described in (1), wherein a predetermined opposed roller of the plurality of opposed rollers is deposited by fluorine resin.
(4) In accordance with another aspect of the present invention, a photo-thermographic recording apparatus comprises a film loading device capable of loading a plurality of different sizes of sheet type photo-thermographic films having a rectangular shape, a conveyance device for conveying a sheet type photo-thermographic film from the film loading device, an exposing device for forming a latent image corresponding to an image signal onto the sheet type photo-thermographic film conveyed by the conveyance device and a thermal developing device for visualizing the latent image formed onto the sheet type photo-thermographic film while the thermal developing device heats the photo-thermographic film, the thermal developing device including a heating device and an opposed roller for pressing the sheet type photo-thermographic film on to the developing device wherein the plurality of opposed rollers includes a predetermined opposed roller deposited by fluorine resin and at least the predetermined opposed roller does not contact an edge portion in which a maximum size of the photo-thermographic film contacts the heading device.
According to the photo-thermographic recording apparatus, since the lubricity, the repellency and the non-adhesiveness of opposed roller are improved by plating fluorine resin onto the opposed rollers, it become difficult for foreign matters such as cohesion substance of organic acid and/or higher fatty acid being volatized from a photo-thermographic film when developed, cutting dregs and emulsion flakes to be adhered to the surface of the opposed rollers. Consequently, adhering and growth of foreign matters on the opposed rollers can be prevented and it becomes possible to lower the possibility of damage to the heating drum by grown foreign matters. As a result a cleaning cycle can be prolonged.
(5) In accordance with another aspect of the present invention the photo-thermographic recording apparatus described in (4), wherein the conveyance device conveys different sizes of sheet type photo-thermographic film with a plurality of different phases in a lateral direction, and conveys the sheet type photo-thermographic film on a slant to the opposed roller of the heating device, the sheet type photo-thermographic film being placed within a maximum phase width in the lateral direction.
According to the photo-thermographic recording apparatus, since a small sized sheet type photosensitive film is conveyed in a slant position to the opposed rollers, the entrance positions of the front edge and rear edge of the film to the opposed rollers are different. Consequently, film cutting dross and emulsion flakes are not concentrated but distributed. As a result, cores on which higher fatty acid volatized from the film is distributed when the apparatus operates and it becomes difficult for cohesion subject to grow into large solid subject when the apparatus is not operated. Consequently, uniform contact between the heating device and the film and the pressing device (opposed rollers) can be obtained. Further, foreign subject can be distributed when photo-thermographic film size is changed from a small size to a large size, and the maintenance cycle of the apparatus can be prolonged comparing with a conventional apparatus.
A preferred embodiment of the present invention will be described by using drawings below.
Photo-thermographic recording apparatus 100 shown in
First loader 11 and second loader 12 of feeder 110 are capable of loading different sizes of films respectively. A film conveyed from first loader 11 or second loader 12 is conveyed via conveyer 5 by paired conveyance rollers 139 and 141 (first conveyer) in the direction (1) indicated by an arrow as shown in
Paired conveyance rollers 139, 141, 142, 146, 145, 144 and 143 are driven by motors 151 and 156 being controlled by CPU (Central Processing Unit) in controller 152 as shown in
Exposing device 120 will be described below. Exposing device 120 forms a latent image onto film F by using laser beam L. As shown in
The configuration of exposing device 120 will be described below. As shown in
Laser beam L radiated from laser beam source 110a is arranged to be guided on polygon mirror 113 rotated in the direction A′ shown in arrow in
The cylindrical lens of fθ lens 114 is arranged to converge incident laser beam L only in the sub-scanning direction onto surface to be scanned 117 of film F. The distance from fθ lens 114 to surface to be scanned 117 is arranged to be the focal distance of fθ lens 114. As described above, in exposing device 120, since fθ lens 114 including a cylindrical lens and mirror 116 are provided and further laser beam L is once converges on the surface of polygon mirror 113 in the sub-scanning direction, the scanning position on surface to be scanned 117 of film F does not shift even though surface deflection and/or shaft deflection occur/occurs, and as a result, constant pitch scanning can be conducted. Polygon mirror 113 has advantage that it is superior to a galvanometer mirror and an optical deflector in scanning stability. As described above, a latent image based on image signal S is formed onto film F.
Thermal developing device 130 has heating drum 14 as a heating member which heats film F while holding film F being in contact with the outer surface of heating drum 14 in thermal developing device 130. Heating drum 14 changes a latent image formed on film F into a visible image by heating and keeping film F at temperature more than minimum thermal developing temperature for a predetermined thermal developing time. The minimum thermal temperature is temperature at which the latent image formed on film F starts to be developed. For example, it is more than 95° C. Thermal developing time is time for which film F should be kept at temperature more than the minimum thermal developing in order to develop a latent image into a visible image having needed developing characteristic. Still, it is preferable that film F should not be thermally developed at less than 40° C.
As shown in
Opposed roller 16 is structured by stainless steal. Opposed rollers 16a, 16b and 16c provide in the upper stream have a diameter of 12 mm being large diameter solid roller and the rest of opposed rollers, from 16d to 16e structured by a pipe having a diameter of 8 mm being a small diameter roller. It is preferable that the thermal capacity of opposed roller 16 is not less than 0.16 kJ/K and the thermal capacity of stainless steal being a material of opposed roller is about 0.18 kJ/K.
Opposed rollers 16a and 16b of the plurality opposed rollers 16 structured by a steel metal material have deposited-fluorine resin and nickel thereover. For example, electroless deposition of Ni—P is conducted by dipping the opposed rollers being a substance to be deposited into solution and depositing the minute particle of polytetrafluoroethylene (PTFE) being fluorine resin onto nickel coating. It gives the surface of the opposed rollers lubricating ability, repellency and non-stickiness. Accordingly, since opposed rollers 16a and 16b have superior lubricating ability, repellency and non-stickiness, it becomes difficult for foreign matters such as cohesion substance of organic acid and/or higher fatty acid being volatized from a photo-thermographic film when developing, cutting dregs and emulsion flakes to be adhered to the surface of the opposed rollers.
In both edges of heating drum 14, three guiding brackets 21 supported by flame 18 is provide in each side. Opposed “C” type shape is formed by combining guiding brackets 21 in the both ends of heating drum 14.
Guiding bracket 21 temporally holds a plurality of opposed rollers 16 at both ends of the opposed rollers 16. The holding position by brackets 21 is arranged to be adjustable. Namely, the relative position of a plurality of opposed rollers 16 against heating drum 16 can be adjusted by adjusting the position of guiding brackets 21. Accordingly, since the parallel accuracy between the axis direction of heating drum 14 and opposed rollers 16 can be adjusted, a film can uniformly contact the outer peripheral surface of heating drum 14. Particularly, as described later, when a smooth surface of fluorine resin is provided on the outer peripheral surface of heating drum 14, providing guiding bracket 21 capable of adjusting the parallel accuracy, even though the density unevenness is likely to occur, can prevent density unevenness.
Nine long holes 42 extended in a radial direction are provided each of guiding bracket 21. Shaft 40 provided in the end portion of opposed roller 16 is extended from long hole 40. One end of each coil spring 28 is attached to each shaft 40 and another end of each coil spring 28 is attached to the portion adjacent to the inner edge of guiding bracket 21. Accordingly, each opposed roller 16 is forced to the direction toward the outer peripheral of heating drum 16 based on the predetermined force of each coil spring 28. Film F is uniformly heated by being pressed toward the outer peripheral surface of heating drum 14 by the predetermined force when film F is inserted between heating drum 14 and opposed roller 16. As described above, opposed roller 16 forced toward heating drum 14 being rotated coveys a film while sandwiching the film with heating drum 14.
Shaft 22 coaxially connected to heating drum 14 extending toward the outer direction from end member 20 of flame 18 is freely supported by end member 20 via shaft bearing 24. A gear (not shown) is formed in rotary shaft 23 of micro-stepping motor (not shown) located under shaft 22 and attached to end member 20. Another gear is formed in shaft 22. Power of the micro-stepping motor is transmitted via timing belt 25 which connects both gears and rotates heating drum 14. It is also possible to transmit the power from rotary shaft 23 to shaft 22 via a chain and gear instead of timing belt 25.
As shown in
The thickness of elastic layer 38 and thermal conductivity are selected so that a continuous process of a plurality of films F can be efficiently conducted. It is preferable that the thermal conductivity of elastic layer 38 is not less than 0.5 W/k. It is preferable that the hardness of elastic layer 38 is from 20 to 70 degree in Japanese Industry Standard (JIS)-A hardness. Elastic layer 38 may be indirectly attached on to sleeve 36.
Elastic layer 38 can be structured by rubber or a rubber type member. As rubber or rubber type member, other than various rubber materials or thermoplastic elastomer, various materials having elasticity being the same as that of rubber member are widely available. For example, various rubber material, resin material and thermoplastic elastomer may be used as a single material or a mixed material. In this case, each rubber material is not limited and for example, other than solid rubber member, liquid type reaction hardening substance which can be obtained by hardening liquid type elastic substance may be used.
With regard to a solid rubber material, for example, ethylene-propylene-ternarycopllymer (EPDM), butyle rubber, polyisobutylene, ethylene-propylene rubber, chloroprene rubber, natural rubber, styrene-butadiene rubber, styrene-isoprene-styrene, styrene-butadiene-styrene or polyurethane rubber is singularly or compositely used with vulcanizing agent or combination agent such as cross linking agent, vulcanization accelerator, vulcanization accelerating auxiliary agent, tackifier, bulking agent, plasticizer, agent resistor or solvent being used in a general rubber industry is combined with a single and combination material of polymer.
Liquid type rubber material includes urethane, liquid state polybutadiene, degeneration silicon, silicon and polysulphide. It is preferable that these material described above is used after mixing a predetermined hardening agent and reaction-hardening. Elastic layer 38 may be formed into a solid state or a sponge state.
With regard to fluorine resin used for depositing for forming smooth-layer 39, for example, chemical compound of polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinyliden fluoride (PVDF), copolymer of oethylene and perfluoroalkoxyethylene (ETFE), copolymer of tetrafluoroethylene and hexafluoropropylene (FEP) is used.
When film F placed around heating drum 14 is heated due to heating phenomenon, for example, gas containing chemical ingredient such as organic acid is generated. However, since fluorine resin which structures smooth layer 39 provided on the surface of elastic layer 38 has non-chemical reactivity, it does not react to gas ingredient such as organic acid. Accordingly, fluorine resin is not be deteriorated. Also, since fluorine resin shuts off the gas ingredient so that the gas ingredient does not contact elastic layer 38 structured by silicon rubber, etc., elastic layer 38 is not be deteriorated or degenerated by the gas ingredient. Accordingly, since the secular change of the shape and characteristic of elastic layer 38 seldom happens, initial elasticity and thermal conductivity can be maintained.
It is preferable that the thickness of smooth layer 39 is not less than 10 μm from the view point of preventing elastic layer 38 from deterioration by gas ingredient of organic acid, and not more than 60 μm from the view point of preventing density unevenness.
It is necessary to pay attention to the selection of the forced power of coil spring 28, since the force power of coil spring 28 is determined so that film F securely contacts the outer peripheral surface of heating drum 14 and is steadily conveyed while receiving enough thermal transmission. Namely, when forced power of coil spring 28 is small, it is anticipated that heat does not uniformly transmit onto film L and resulting incomplete image development and unsteady conveyance of film F.
The relationship between a contacting area of opposed roller against the heating drum (a position of opposed roller) and a contacting area of film against the heating drum (a film passing width) will be described by using
As shown in
A film is conveyed between heating drum 14 and opposed roller 16 by the rotation of heating drum 14 while being heated in the circumferential direction of heating drum 14 shown in
As shown in
As shown in
Further it becomes possible to prolong the maintenance cycle of an apparatus since it is possible to prevent foreign matter based on a core of adherence from growing by the repetition of operation/stopping cycle of the apparatus.
As shown in
The configuration for correcting an exposure amount in a portion where a film contacts a heating drum but does not contact an opposed roller (corresponding to distance) shown in
As shown in
Further, the correction amount corresponding to distance B shown in
According to controller shown in
Since a film area corresponding to distance B which does not contact opposed roller 16 shown in
Further, small diameter portion 16h of opposed roller 16 is corresponding to the edge portion of film contacting width A and distance B is secured between boarder 16i of opposed roller and each edge of film contacting width A. Consequently, when a film is conveyed to the direction H as shown in
Further more, two opposed rollers 16a and 16b positioned in the upper stream have nickel and fluorine resin deposited onto the surface of opposed rollers 16a and 16b. Accordingly opposed rollers 16a and 16b have superior lubricating ability, repellency and non-stickiness. As a result it become difficult for foreign matters such as cohesion substance of organic acid and/or higher fatty acid being volatized from a photo-thermographic film when developing, cutting dregs and emulsion flakes to be adhered to the surface of the opposed rollers.
Further, as shown in
In case that photo-thermographic recording apparatus 100 shown in
The present invention will be described in detail by using an embodiment. As the embodiment of this invention, a photo-thermographic recording apparatus as shown in
After processing fifteen thousand photo-thermographic film of 14×17 inch films, the thickness of dirt adhesive adhered on each opposed roller in the photo-thermographic recording apparatus of the embodiment above was measured. The measurement result will be shown in
According to
The embodiments of the present invention has been described however, the resent invention is not limited to the embodiments. It is possible to modify and vary the present invention without departing from the scope of the present invention. For example, as shown in
As shown in
Further, it is preferable that when depositing fluorine resin and nickel, it should be apply not only onto large diameter portion 16g and 16g′ shown in
In this embodiment, fluorine resin and nickel are deposited onto two opposed rollers 16a and 16b positioned in most upstream side. However, it is preferable that when foreign matter adhesive described above become problems on other opposed rollers due to the relationship between the structure of thermal developing device 130 and a position of an exhauster, rollers deposited with fluorine resin and nickel are used.
Further, in
Cleaning device 13 provided in photo-thermographic recording apparatus shown in
Cleaning device 13 for cleaning the surface of heating drum 14 is provided under heating drum 14 in thermal developing device 130 of photo-thermographic recording apparatus 100. As shown in
Cleaning device 13 is moved in the direction indicted by arrow T from a solid line position shown in
As described above, since cleaning device 13 firmly presses cleaning web 13a against the surface of heating drum 14 in cleaning and keeps away from it in non-cleaning, cleaning web does not increase load for heating drum 14 when it rotates for heating film.
Cleaning web 13a is structured by a long sheet of nonwoven fabric absorber. Cleaning web 13a has thermal resistance for heat from heating drum 14 and chemical resistance for enduring organic acid and cohesion substance such as MEK and efficiently absorbs adhesion on the surface of heating drum 14 by contacting pressing roller.
When roll-up roller 13d is rotated in the rotation direction r as shown in
When cleaning heating drum 14, heating drum 14 rotates in the direction R so that the whole outer peripheral surface of heating drum 14 is cleaned. At that time, cleaning web 13a moves in the direction W as shown in
It may be also possible to contact stopped cleaning web 13a to smooth surface layer 39 of heating drum 14 while heating drum 14 rotates in the direction R. In this case, it is preferable that after finishing the cleaning and cleaning device 13 moves away from heating roller 14 in the direction T′ indicated by an arrow in
A control system for controlling cleaning device 13, paired conveyance rollers 144, conveyer 5 will be described by using
Controller 152 shown in
Also controller 152 controls motors 155 and 156 for driving paired conveyance rollers 143 and 144, and driving motor for conveyer 5 in order to select the different sizes of films from loading devices 11 and 12.
A guide for guiding film F moved away from heating drum 14 for the first time by using
As shown in
Next, an example for conveying a small size film being in a slant position with regard to a heating drum and opposed rollers in thermal developing device 130 will be described by using
As shown in
The plurality of rubber rollers 144c-144f conveys a large size film, for example, a film having width of fourteen inches, and inside rubber rollers 144d and 144e involve conveyance of small size film, for example, a film having width of eight inches.
Further, following rollers 144b is constructed so that following rollers 144b can be pressed or moved to/from driving roller 144a by a driving device such as a solenoid. When following rollers 144b presses driving roller 144a, each following rollers 144c-144f becomes ready for conveying film with predetermined nip pressure. When following rollers 144b moves away from driving roller 144a, film conveyance stops.
The diameter of either rubber rollers 144d or 144e being internal rollers of following rollers 144b, for example, following roller 144e is arranged smaller than that of other rubber rollers 144c, 144d and 144f. Since, when a film is conveyed into between driving roller 144a and following rollers 144b perpendicularly with regard to the surface of the drawing paper sheet, a film pressing timing of rubber roller 144e is slightly delayed, the film slightly slants the position in a film plane with regard to the film conveyance direction. It is possible to change the degree of slat of the film by adjusting the diameter of rubber roller 144e.
Next, the slant conveyance of the small size film with regard to a heating roller and opposed rollers, and the cleaning effect performed when a film is changed to a large size film will be described by referring to
The film sandwiched in a nip section formed by driving roller 144a and rubber rollers 144c-144f of following roller 144b is conveyed by driving roller 144a.
As shown in
In case that small sized film FA (for example, 8×10 inch sized film) is conveyed, since the diameter of rubber roller 144e is smaller than that of other rubber rollers, pressing timing of rubber roller 144e delays comparing with that of other rubber roller, for example, 144d. Consequently, the film conveyance of right front corner Fb of small sized film FA delays and as a result, left corner Fa is conveyed earlier which resulting a slant conveyance.
Then, small sized film FA enters between heating drum 14 and opposed roller 16a as shown in dashed line and right corner Fb enters following the entrance of let corner Fa with a small differences corresponding to the slant of the film. Film F is conveyed between following opposed roller 16b and heating drum 14 as the same position of film slant is kept, and sequentially conveyed by opposed rollers in the downstream side.
As described above, since small sized film FA gradually enters into each opposed roller 16 with the corner of the film first, the entrance resistance is decreased comparing with that of parallel conveyance. As a result, it becomes possible to depress the optical density unevenness due to the arrangement pitch of opposed roller 16.
As described above, since small sized film FA is conveyed into each opposed rollers 16a, 16b, etc., with a slant position, the entrance position of the film with regard to each opposed roller 16 is different in terms of front and rear edges. Consequently, film F is conveyed as the side edges F1 and F2 of film F is shifted relative to the each opposed roller 16. As a result, since film cutting dross and emulsion flakes are not concentrated into a line shape, but they are distributed. Namely, since cores on which cohesive substance (higher fatty acid volatized from the film in operation being solidified in non-operation as temperature coming down) are distributed, it becomes difficult for cohesive substance to grow into large size foreign matters. As a result, it becomes difficult for cohesive substance to be adhered. For this reason, since it becomes possible to secure uniform contact and heat transmission between heating drum 14 and film F and opposed rollers 16 when a film is heated and conveyed in thermal developing device 130, image deteriorations due to optical density unevenness can be prevented.
Further, when film size is changed from small sized film FA to large sized film FB, for example, to 17×14 inch sized film, as shown in
As described above, since passing footmarks on the surface of heating drum 14 are removed by cleaning web 13a by the cleaning before the processing a large sized film, it does not affect to the image of large sized film.
Further, according to the slant conveyance of small sized film, comparing with conventional cases, it becomes difficult for clumping subject to grow to large solid foreign matter and cleaning effects are improved. Since, cleaning is performed when a film is changed to a large sized film, the maintenance cycle of an apparatus can be prolonged and maintenance cost can be lowered.
The cleaning by cleaning device 13 may be conducted based on the number of times of small sized film process before changing to a large sized film. In this case, since the adhesion distribution of the emulsion flakes and cutting dross onto the surface of heating drum 14 is distributed due to the slant conveyance described above, a large number of processing for small sized films can be set and the number of times of cleaning can be lowered.
Further, in case that the maximum small sized film which can be process (with regard to width) is, for example, 8×10 inch sized film, the phase difference between the leading edge and rear edge of the film is 2-6 mm per 10 inches, the optical density unevenness due to rush entrance to opposed roller 16 is not recognized. The foreign matter originated from a film such as the emulsion flakes is distributed, and foreign matters on heating drum 14 and each opposed roller 16 are not concentrated into one point or one line.
In case that the most outside surface of elastic layer 38 of heating drum 14 is formed by fluorine resin, emulsion flakes of a film and cutting dross are easily adheres onto metal opposed roller 16 due to the good mold release characteristic, but not on heating drum 14. Since foreign matters and solid subjects which give damages to smooth surface layer is difficult to be occurred, long life smooth surface layer 38 can be realized.
If a film is conveyed in a slant position before a film exposing process, image data has to be arranged to correspond the slant position for the film exposure. In order to do this, the control sequence and the configuration of controller 152 become complicated. However, according to the embodiment of the present invention, since the slant conveyance begins after the exposure, the configuration of controller 152 does not become complicated.
The present invention is explained based on the embodiment described above. However the present invention is not limited to the embodiment. It may be changed and modified without departing from the scope of the present invention. Foe example, in
Further, in this embodiment, conveyance roller 144 provided in the upstream of paired conveyance rollers 143 arranged adjacent thermal developing device 130 is used for the slant conveyance of a film. However, it is not limited to this embodiment. One of the paired rollers from paired conveyance rollers 144 to paired conveyance rollers 146 may be used for the slant conveyance. As described above, once a latent image is formed by two pairs of conveyance rollers 142, it is possible to control the position of the small sized film by adjusting a left and right pressing timing and/or nipping pressure of small sized film as shown in
In case that paired conveyance rollers 146 positioned in just downstream side of paired conveyance roller 142 is used the slant conveyance, it is necessary to open opposed roller 146 by using a driving device such as a solenoid so that the exposed portion of the rear edge the film is not affected by the conveyance of the leading edge of the film, and to close rollers 146 after finishing the exposure of the rear edge of the film. Paired conveyance rollers 146 may be, for example, just like a structure shown in
Further, cleaning device as shown in
Number | Date | Country | Kind |
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JP2004-026634 | Feb 2004 | JP | national |
JP2004-042796 | Feb 2004 | JP | national |
JP2004-042797 | Feb 2004 | JP | national |
JP2004-155963 | May 2004 | JP | national |