Patent Application
20090134566
The present invention relates to photosensitive material conveying systems that feed out using a feeding out roller a plurality of photosensitive sheet films that have been stacked, and to image forming apparatuses.
Thermal development apparatuses are known that execute a thermal development process of forming latent images on a sheet film made of a thermal development photosensitive material and making the images visible by developing using an application of heat, and sheet films stored in a storage container inside a thermal development apparatus are picked up for conveying and supplying the sheet films to the downstream side. In order to pick up such sheet films, although conventionally the suction cup method is used for lifting up the sheet films while adhering to them by vacuum suction, in this suction cup method, the time taken for picking up becomes long, and hence cannot be selected from the point of view of speedy processing of the thermal development process.
Because of the above reason, the feed roller method is desirable in order to minimize the time required for picking up films. In the feed roller method, a roller is contacted with the topmost sheet film and rotated thereby feeding out the sheet film (see, for example, Patent Document 1).
However, at the time of feeding out several sheet films stacked in a storage container using a feed roller, there was a problem that scratches could occur easily because the sheet film being fed out moves almost in parallel with being in contact with and rubbing against the sheet film below it.
Patent Document 1: Specification of U.S. Pat. No. 5,660,384.
The present invention was made in view of the above problems in the conventional technology, and the purpose of the present invention is to provide a photosensitive material conveying system and image forming apparatus in which it is difficult for scratching of sheet films to occur while feeding out a plurality of stacked sheet films using a roller.
In order to achieve the above purpose, the following finding was obtained as a result of keen study and investigation made by an inventor of the present invention about the causes that make scratches easy to occur in the sheet film at the time of feeding out, using a roller, a plurality of stacked photosensitive sheet films.
In other words, as has been shown in the schematic diagram of
In view of this, as is shown in
In addition, since the contact pressure of the feeding out roller on the film is 0.49N/cm or less, the force acting locally between the contacting films becomes small, and the possibility of the matting agent scratching the surface EC of the film on the contacting side gets reduced.
The present invention was made based on the above findings. In other words, the photosensitive material conveying system according to the present invention is a photosensitive material conveying system with a construction so that a feed out roller is contacted on a stack of sheets having a plurality of stacked photosensitive sheet films that are provided with an emulsion layer and a first protective layer provided on one side of a supporting base and a second protective layer provided on the other side with a matting agent dispersed in the second protective layer, and the topmost sheet film in the stack of sheets is fed out by the rotation of the feeding out roller, with the feature of the system being that the matting agent has a spherical shape, has a hardness that is softer than the first protective layer, has particles diameters in the range of 8 to 12 μm, and that the contact pressure of the feeding out roller is 0.49N/cm or less.
According to this photosensitive material conveying system, when feeding out a sheet film by contacting the feeding out roller on the topmost sheet film in a stack of sheets, it becomes difficult for scratches to occur on the sheet film, because the matting agent dispersed on the second protective layer has a spherical shape, has a hardness that is softer than the first protective layer, and has particles diameters in the range of 8 to 12 μm, and because the contact pressure of the feeding out roller is 0.49N/cm or less, the force acting locally between the contacting films becomes small, and the possibility of the matting agent scratching the surface of the film gets reduced.
In the above photosensitive material conveying system, it is desirable that the feeding out roller contacts the sheet film on the second protective layer.
Further, it is desirable that the feeding out roller has a prescribed width along a direction at right angle to the direction of conveying, and has a centerline adjusting function in order to make the contact pressure uniform over the entire width of the sheet film. By making the contact pressure uniform over the entire width of the sheet film, since the feeding out roller will not contact the sheet film unevenly along the width direction, it becomes difficult for scratches to occur on the sheet film.
Further, it is desirable that the photosensitive sheet film is a thermal development type photosensitive film, and that the matting agent is PMMA (polymethyl methacrylate).
The image forming apparatus according to the present invention has the feature that it is provided with the photosensitive material conveying system described above, exposes and forms images onto the fed out sheet films. According to this image forming apparatus, since it becomes difficult for scratches to occur on the sheet films due to the photosensitive material conveying system described above, it is possible to form images with a high quality.
According to the photosensitive material conveying system and image forming apparatus according to the present invention, it becomes difficult for scratches to occur made on a plurality of stacked sheet films fed out using a roller, and it is possible to form images with a high quality.
Some preferred embodiments of the present invention are described in the following referring to the drawings.
As is shown in
The image forming apparatus 40 of
Further, the image forming apparatus 40 comprises, a curved surface guide 48 formed in the shape of a curved surface so that the film F from the conveying roller pair 47 is guided and is conveyed after almost reversing the direction of conveying; conveying roller pairs 49a and 49b for conveying the film F from the curved surface guide 48 in the auxiliary scanning direction; an optical scanning exposure section 55 for exposing the film F between the conveying roller pairs 49a and 49b by optically scanning it using a laser light beam L based on the image data thereby forming a latent image on the surface EC; and an optical reflection type or optical transmission type detection sensor 60 that is placed on the upstream side of the conveying roller pair 49a for detecting the film F conveyed from the curved surface guide 48.
The image forming apparatus 40, further, comprises, with a temperature raising section 50 that raises the temperature up to a prescribed thermal development temperature by heating from the side of the surface BC of the film F on which a latent image has been formed; a temperature maintaining section 53 that heats the heated film F and maintains it at the prescribed thermal development temperature; a cooling section 54 that cools the heated film F from the side of the surface BC; a density meter 56 placed on the outlet side of the cooling section 54 and that measures the density of the film F1; a pair of conveying rollers 57 that discharge the film F from the density meter 56; and a film stacking section 58 provided in an inclined position on the top surface of the equipment chassis 40a so that the film F discharged by the conveying roller pair 57 is placed on it.
As is shown in
In addition, the conveying path from the conveying roller pairs 49a and 49b of the auxiliary scanning direction to the temperature raising section 50 has been constituted to be relatively short, while the film F is being exposed by the optical scanning exposure section 55, the front edge side of the film F is subjected to thermal development heating by the temperature raising section 50 and the temperature maintaining section 53.
A heating section is constituted by the temperature raising section 50 and the temperature maintaining section 53, and heats the film F up to the thermal development temperature and maintains it at the thermal development temperature. The temperature raising section 50 has a first heating zone 51 that heats the film F on the upstream side and a second heating zone 52 that heats the film on the downstream side.
The first heating zone 51 has a fixed flat shaped heating guide 51b that is made of a metallic material such as aluminum, etc., a flat shaped heater 51c made of a silicone rubber heater, etc., that is in close contact with the bottom surface of the heating guide 51b, and a plurality of opposing rollers 51a that are placed so as to maintain a gap smaller than the thickness of the film F so that they can push the film F against the fixed guide 51d of the heating guide 51b and whose surfaces are made of silicone rubber, etc., that has thermal insulation characteristic compared to metal, etc.
The second heating zone 52 has a fixed flat shaped heating guide 52b that is made of a metallic material such as aluminum, etc., a flat shaped heater 52c made of a silicone rubber heater, etc., that is in close contact with the bottom surface of the heating guide 52b, and a plurality of opposing rollers 52a that are placed so as to maintain a gap smaller than the thickness of the film F so that they can push the film F against the fixed guide 52d of the heating guide 52b and whose surfaces are made of silicone rubber, etc., that has thermal insulation characteristic compared to metal, etc.
The temperature maintaining section 53 has a fixed flat shaped heating guide 53b that is made of a metallic material such as aluminum, etc., a flat shaped heater 53c made of a silicone rubber heater, etc., that is in close contact with the bottom surface of the heating guide 53b, and a guide section 53a made of a heat insulating material, etc., that is placed opposite the fixed guide surface 53d formed on the surface of the heating guide 53b so as to maintain a gap (slit) d between it. The temperature maintaining section 53 is constituted so as to be flat from the second heating zone 52 from the side of the temperature raising section 50, and is formed to have a curved shape with a prescribed radius of curvature from the middle towards the top part of the apparatus.
The film F is conveyed while being heated in the first heating zone 51 of the temperature raising section 50, because the film F conveyed from the upstream side of the temperature raising section 50 by the conveying roller pairs 49a and 49b, by being pressed against the fixed guide surface 51d by each of the opposing roller pairs 51a that are being rotationally driven, has its surface BC in close contact with the fixed guide surface 51d.
In a similar manner, even in the second heating zone 52, the film F conveyed from the first heating zone 51, by being pressed against the fixed guide surface 52d by each of the opposing roller pairs 52a that are being rotationally driven, has its surface BC in close contact with the fixed guide surface 51d and is conveyed while being heated.
Further, it is also possible to have a configuration in which a V-shaped groove section with its opening part facing up is provided between the second heating zone 52 of the temperature raising section 50 and the temperature maintaining section 53, and because any foreign matter from the temperature raising section 50 falls in the groove part, it is possible to prevent any foreign matter from entering the temperature maintaining section 53 from the temperature raising section 50.
In the temperature maintaining section 53, the film F conveyed from the second heating zone 52, in the gap dd between the fixed guide surface 53d of the heating guide 53b and the guide section 53a, is heated (temperature maintained) by the heat from the heating guide 53b, and passes through the gap dd due to the conveying force of the opposing rollers 52a on the side of the second heating zone 52. At this time, the film F is conveyed while having its orientation changed gradually from being almost horizontal in the gap dd to being almost vertical, and moves toward the cooling section 54.
In the cooling section 54, the film F conveyed almost vertically from the temperature maintenance section 53 is conveyed towards the film stacking section 58 while having its orientation changed gradually from being vertical to an inclined orientation while coming in contact with and being cooled by the cooling guide surface 54c of the cooling plate 54b made of metallic material, etc., due to the opposing roller 54a. Further, it is possible to increase the cooling effect of the cooling plate 54b by making it have a heat sink structure with cooling fins. It is also possible to make a part of the cooling plate 54b have a heat sink structure with cooling fins.
The cooled film F coming out the cooling section 54 has its density measured by a density meter 56, conveyed by the conveying roller pair 57 and is discharged to above the film stacking section 58. The film stacking section 58 can temporarily stack a plurality of films F.
As has been explained above, in the image forming apparatus 40 of
Further, the film F is conveyed by the opposing rollers 51a and 52a so that the time of its passing the temperature raising section 50 and the temperature maintaining section 53 is less than 10 seconds. Therefore, even the heating time from temperature raising to temperature maintaining becomes 10 seconds or less.
Next, explanations are given about the film F. The film F, as same as shown in
As has been explained above, the matting agent dispersed in the second protective layer, in contrast with the shape of the conventional matting agent in
Next, a film conveying apparatus suitable for an image forming apparatus 40 of
Although a film conveying apparatus 61 of
In other words, as is shown in
The lifting mechanism, in addition, comprises a drive motor 67, a contacting cam section 64 with an oval shape that contacts the bottom surface of the lifting plate 63, a cog wheel 65 that swings this contacting cam section 64 around the rotating shaft 64a, and a cog wheel 66 that swings due to the rotating shaft 67a of the driving motor 67 and mates with the cog wheel 65.
The driving motor 67 swings and changes the inclination of the contacting cam section 64 via the cog wheel 66 and the cog wheel 65 so that, even if the films F get reduced after being delivered out one by one, the topmost film is always contacting the conveying roller 46. In other words, when the number of sheets of the film F is large, the contacting cam section 64 makes the longer side direction of the contacting cam section 64 be inclined so that it is almost horizontal, and the longer side direction of the contacting cam section 64 is made to be inclined more and more towards the vertical direction as the conveying progresses and the number of sheets of the film F decreases.
The conveying roller 46 is made of a rotating roller that is driven by a motor (not shown in the figure), contacts with the topmost film F in the film storing tray section 45, and feeds out a film F in the feeding out direction k shown by a broken line in
The conveying roller pair 47 has a progressing roller 47a that applies a progressing force in the direction of conveying to the film F fed out from the conveying roller 46, and a dispensing roller 47b that moves in cooperation with the progressing roller 47a and dispenses the film one at a time. When the conveying roller 46 feeds out several sheets of the film F, while the progressing roller 47a applies a progressing force to the topmost film F, the dispensing roller 47b rotates in a direction opposite to that of the progressing roller 47a and feeds the films below the topmost film F in a direction opposite to the conveying direction and returns the films to inside the film storing tray section 45.
Next, the separating claws that separate the topmost film F at the time that a film is conveyed from the film storing tray section of
As is shown in
When the film F is lifted up from the initial position of
Further, the lifting plate 62 of the film conveying apparatus 61 of
Because of the above configuration, it is possible to control the linear pressure (film nipping pressure) on the film F to within a prescribed range of less than 0.49N/cm, and also, it becomes possible to contain film conveying track to within a prescribed range, and hence it becomes possible to carry out stable film separation and conveying without the generation of scratches.
As has been explained above, although the conveying roller 46 contacts the film F so that the linear pressure is 0.49N/cm or less, as is shown in
When image data is input from and external source to the image forming apparatus 40 of
The feeding out of the film F such as the above from the film storing tray section 45 due to the rotation of a conveying roller 46, makes it difficult for scratches to occur on the film F because the matting agent dispersed in the second protective layer of
In addition, because of the centerline adjustment link mechanism of
As has been explained above, since it becomes difficult for scratches to occur on the surface EC of the film F, it is possible to realize a high image quality in the visible images formed on the film F.
To begin with, the photosensitive film was prepared in the following manner. That is, the photosensitive film was prepared in a manner similar to that of the sample number 115 in the Implementation Example 1 described in lines [0480] to [0519] of the of the Unexamined Japanese Patent Application Publication No. 2005-107496 applied for by the present applicants. However, the matting agent “3-dimensionally cross-linked polymethyl methacrylate: PMMA, average particle diameter 10 μm, truly spherical shape, degree of monodispersion 10%” was employed in place of the matting agent (3-dimensionally cross-linked polymethyl methacrylate: PMMA, average particle diameter 5 μm) in the “BC layer protective layer coating liquid” described in line [0494].
After feeding out films using the above film as shown in
1. The roller linear pressure was 0.08N/cm using two rubber rollers of 60 mm width when the load of the conveying roller unit was made to be 0.49N.
2. The roller linear pressure was 0.16N/cm using two rubber rollers of 60 mm width when the load of the conveying roller unit was made to be 0.98N.
3. The roller linear pressure was 0.33N/cm using one rubber roller of 30 mm width when the load of the conveying roller was made to be 0.98N.
4. The roller linear pressure was 0.49N/cm using one rubber roller of 30 mm width when the load of the conveying roller unit was made to be 1.47N.
While the results of the above implementation examples 1 to 4 are shown schematically in
In addition, while we carried out similar experiments with the two types of thickness of the first protective layer of 3 to 4 μm and 7 to 8 μm, the generation of scratches when observed visually using an X-ray film viewer was smaller in the latter than in the former. This is considered to be because, even if sharp dents (scratches) are formed in the protective layer, the surrounding protective layer gets pressed during the process of conveying up to the exposure position thereby softening the shape of the dents, or gets pressed and flattened by the opposing rollers in the thermal development section after exposure, when the finished film is viewed in an X-ray film viewer, it is difficult for the light of the viewer (the transmitted light) to scatter or diffract around the area of the projections, thereby making the dents difficult to be observed, and hence they are not recognized as scratches.
Although a preferred embodiment of the present invention was described above, the present invention shall not be construed to be limited to this preferred embodiment, and various modifications can be made within the scope of the technical concepts of the present invention. For example, an image forming apparatus 40 as shown in
In addition, although the entire image forming apparatus 40 of
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-290227 | Oct 2005 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2006/318560 | 9/20/2006 | WO | 00 | 3/27/2008 |
