Patent Application
20060071421
1. Field of the Invention
The present invention relates to a conveying roller having plural projections on an outer peripheral surface thereof, a method for producing the conveying roller and a conveying apparatus using the conveying roller.
2. Background Arts
For example, a photographic printer performs processes of exposing, developing, drying and the like in this order to a photosensitive recording paper of a cut-sheet type while conveying in a sub-scanning direction. The photosensitive recording paper is nipped and conveyed by a plurality of conveying roller pairs disposed along a passage. Because of the restrictions such as a printer size and the like, the passage is curved in up-and-down directions in several sections in the printer, particularly in a processing tank in which a processing solution for developing is stored. For that reason, the plurality of conveying roller pairs are placed in the processing tank at narrow intervals.
When the conveying roller is constituted of flat rollers, the photosensitive recording paper is frequently squeezed by the flat rollers. As a result, the quality in edge portions of the photosensitive recording paper may be deteriorated. Further, when the photosensitive recording paper is nipped by one side of the conveying roller pair in a width direction, a roll alignment may be changed. Accordingly, a conveying force becomes unbalanced in the width direction so that the photosensitive recording paper may be skewed. In order to prevent such problems, the conveying roller pair disposed in the processing tank is usually constituted of a projection roller, which has plural projections on an outer peripheral surface thereof, and the flat roller (see page 4 of Japanese Patent Laid-Open Publication No. 2001-106376).
The projection roller is usually formed by inserting a cylindrical core, which is made of metal or resin, into a silicone rubber tube whose outer peripheral surface is formed with plural projections. An external diameter of the core is larger than an internal diameter of the silicone rubber tube. In that case, slipping of the silicone rubber tube against the core is prevented by a tightening force of the rubber tube alone. Further, there is a known method for producing the projection roller, in which a rubber roller is inserted into a tube, and the outer peripheral surface of the rubber roller and the tube are adhered with using a primer (see page 3 of Japanese Patent Laid-Open Publication No. 5-147125). Furthermore, instead of using the primer, there is a method in which the core and a rubber layer are directly adhered through chemical bonding between a vulcanized rubber and a thermoplastic resin by forming the rubber layer made of the vulcanized rubber on the outer peripheral surface of the core made of the thermoplastic resin.
When producing the projection roller using the above methods, a width of the rubber tube with the projection is usually formed longer than the width of the passage. However, in that case, an outer diameter of the projection tube tends to vary in the width direction. As a result, contact condition and contact pressure between the photosensitive recording paper and the projections of the projection roller vary in the width direction, which may generate the skew of the photosensitive recording paper. In order to prevent such problems, the projection roller is formed by attaching plural projection tubes to the core (see page 4 of Japanese Patent Laid-Open Publication No. 2001-106376). Thereby, phases of the projections formed in adjacent projection tubes are shifted so that arrangements of the projections become random. Accordingly, the variations in the outer diameter of the projection tube are virtually canceled.
When the projection roller, which prevents the slipping of the projection tube only by the tightening force thereof, is used, the tightening force of the projection tube is down by a slight swelling of the projection tube in the processing solution, or the stress relaxation of the projection tube itself. In particular, since the projection roller is soaked in the processing solution for a long time, the projection tube is swelled to a certain extent even if the projection tube is formed of a chemical-resistant material. Especially in the developing solution, the problems such as the slipping of the projection tube and failures in conveying the photosensitive recording paper tend to increase as the tightening force of the projection tube is down by the swelling. Further, since the projection roller nips and conveys the photosensitive recording paper with a high conveying force while deforming the projections formed on the outer peripheral surface thereof, the stress is concentrated at the projections. As a result, the stress applied to the projections during the conveyance accelerates the expansion of the projection tube which causes stress relaxation. Accordingly, the slipping occurs easily.
Inserting the core into the projection tube is troublesome since the core should be inserted while expanding the projection tube. Further, when inserting the core into the projection tube, there may be a gap between the core and the projection tube, or a distortion on the projection tube. As a result, the position of each projection may deviate from the designed position, or the outer diameter of each projection tube may vary. Furthermore, an edge of the core may tear the projection tube when inserting the core into the projection tube.
When plural projection tubes are attached to the outer peripheral surface of the core, the variations in the outer diameter of the projection tube are canceled as the phase of the projection arrangement is shifted in each projection tube (see page 4 of Japanese Patent Laid-Open Publication No. 2001-106376). However, in that case, a leading end of the photosensitive recording paper may be curled and damaged, and projection marks may be caused by the projections deforming the recording paper in the leading end, since a part of the leading end of the recording paper may enter between the rollers at a large entry angle with respect to the projections. Further, since the contact condition and the contact pressure between the photosensitive recording paper and the projection roller cannot be kept constant throughout the width direction, the skew of the photosensitive recording paper cannot be prevented.
To solve such problems, there is a method in which the projection tubes are attached to the core such that each projection is aligned in the same phase. However, it is difficult to manually set each projection in the same phase. Further, note that the page 4 of Japanese Patent Laid-Open Publication No. 2001-18328 does not disclose a method for performing phase alignment of each projection when forming the vulcanized rubber layer on the outer peripheral surface of the core made of the thermoplastic resin. Furthermore, the core made of the thermoplastic resin is usually formed by injection molding using a mold. At that time, gas generated during the injection molding may be deposited on the surface of the core depending on deterioration of the mold with time lapse and the type of the material used for the injection molding. As a result, the deposited gas may weaken the chemical bond between the resin and the vulcanized rubber when the vulcanized rubber layer is formed on the outer peripheral surface of the core made of thermoplastic resin. Accordingly, there is a possibility that required level of the adhesive strength is not obtained.
An object of the present invention is to provide a conveying roller, a production method thereof and a conveying apparatus which prevent failures in conveying by preventing slipping of an elastic layer around an outer peripheral surface of the core.
Another object of the present invention is to provide a conveying roller, a production method thereof and a conveying apparatus which prevent the failures in conveying by keeping contact condition and contact pressure constant between a sheet and the conveying roller.
In order to achieve the above and other object of the present invention, an elastic layer with plural projections of the same phase is formed by coating molding on an outer peripheral surface of a core. A conveying roller includes a roller shaft and plural cores fixed to the roller shaft such that the cores and the roller shaft integrally rotate about a rotation center line of the roller shaft. The elastic layer with plural projections is formed on the outer peripheral surface of each core after a primer layer is formed on the core. The core and the elastic layer are adhered through the primer layer. Before forming the primer layer, it is preferable to perform blasting to the surface of the core for increasing adhesive strength.
Further, the plural projections are aligned to form projection lines, which are parallel to the rotation center line, and the projection lines are arranged at a constant pitch in a circumferential direction. The adjacent projection lines in the circumferential direction are shifted in the direction of the rotation center line and arranged in a zigzag. Further, a fitting hole is formed through the core along the rotation center line, and the plural cores are attached to the roller shaft by inserting the roller shaft into the fitting hole. It is preferable to attach a fixing member to the roller shaft and form an engaging section in each core for fixing each core to the roller shaft by engaging the fixing member in the engaging section.
In a method for producing the conveying roller of the present invention, the elastic layer with plural projections is formed by coating molding on the outer peripheral surface of the core. The plural cores formed with the elastic layer are fixed to the roller shaft such that the plural cores and the roller shaft integrally rotate about the rotation center line of the roller shaft. The coating molding of the elastic layer is performed by setting the core as a core in the in a mold, and filling an elastic material in a cavity formed between the core and the mold. The core is set in the mold in a predetermined position in the circumferential direction.
The core is formed of a thermoplastic resin material, a thermosetting resin material or a metal material. The elastic layer is preferably formed of a vulcanized rubber or a thermoplastic elastomer. It is preferable that the hardness is approximately 50 degrees.
A conveying apparatus of the present invention includes a conveying roller pair. The conveying roller pair includes the conveying roller and a flat roller used in a pair with the conveying roller for nipping and conveying the sheet. Further, it is preferable that the projections in a nip area, where the sheet is nipped, are deformed so that the projections outside the nip area in a width direction of the conveying roller contact the flat roller when the conveying roller and the flat roller nip the sheet. Furthermore, it is preferable to use a photosensitive material as the sheet. The conveying roller pair is preferably disposed in a storage tank in which processing solution is stored. It is preferable that the elastic layer, the core and the primer layer are chemical-resistant to the processing solution.
The conveying roller, a production method thereof and a conveying apparatus using the conveying roller prevents the slipping of the elastic layer on the outer peripheral surface of the core while conveying the sheet, since the elastic layer with the plural projections is formed by coating molding on the core. As a result, the failures in conveying the sheet is prevented. Further, although the number of the processes for producing the conveying roller is increased by forming the elastic layer, the working efficiency is substantially improved as the processes for inserting the core into the projection tube become unnecessary. Furthermore, the core is no longer inserted into the projection tube by manual work. Accordingly, yields in manufacturing the projection roller and the quality stability are improved at the same time.
The entry angle of the sheet can be kept constant throughout the leading end of the sheet while the sheet enters between the conveying roller and the flat roller which form the conveying roller pair. As a result, it becomes possible to prevent the projection marks which are caused by the projections pressing the part of the sheet. Further, the contact condition and the contact pressure can be kept constant throughout the width section of the sheet. Accordingly, the skew of the sheet is prevented by preventing unbalance in the conveying force of the conveying roller and changes in the roll alignment.
Further, since the core and the elastic layer are adhered through the primer layer, the uniform adhesive strength is secured regardless of the surface profile in the core.
The above objects and advantages of the present invention will become apparent from the following detailed descriptions of the preferred embodiments when read in association with the accompanying drawings, which are given by way of illustration only and thus do not limit the present invention. In the drawings, the same reference numerals designate like or corresponding parts throughout the several views, and wherein:
As shown in
The image input device 11 generates image data by photoelectrically reading an image recorded on a photographic film by using an image capture device such as a CCD image sensor, or obtains the image data by reading the image data recorded in a recording medium such as a memory card, CDR, DVD-R and the like. The image data is sent to the image processing device 12, and image processing such as color balance correction and density correction are performed to the image data. After the image processing, the image data is sent to the printer 13.
The printer 13 records images on a photosensitive recording paper (a recording material), which is cut in a predetermined length, using recording light whose intensity is modified according to the image data, while conveying the photosensitive recording paper in a sub-scanning direction (a conveying direction). The printer 13 is provided with a supply section 17, a back-printing section 18, a skew-correcting section 19, an exposure section (image recording section) 20, a receiver section 21, a sorter section 22, a carrying section 23 and the like in this order from an upstream. In each of the above sections, plural conveying roller pairs, each of which is constituted of a drive roller and a nip roller, are disposed along a main passage 24 (indicated by an alternate long and short dash line in
In the supply section 17, magazines 27a and 27b are set. Each of the magazines 27a and 27b contains a recording-paper roll 26 which is a photosensitive recording paper 25 in a roll form. In the magazines 27a and 27b, paper roller pair 28a and 28b are disposed respectively for pulling out and conveying the photosensitive recording paper 25 toward the back-printing section 18. When the paper roller pair 28a and 28b are rotated by a paper feed motor (not shown), the photosensitive recording paper 25 is pulled out from the recording-paper roll 26 and conveyed toward cutters 30a and 30b. The cutters 30a and 30b cut the photosensitive recording paper 25, which is pulled out for a predetermined length in accordance with the print size, to form a paper sheet 35.
In the embodiment, since the paper sheet 35 is conveyed in a single line to the sorter section 22, which will be described later, timing of supplying the paper sheet 35 from each of the magazines 27a and 27b is automatically adjusted. Further, when the magazines 27a and 27b contain the same type of the photosensitive recording paper 25 (the recording-paper roll 26), the photosensitive recording paper 25 may be pulled out from one of the magazines (27a or 27b) first, and then from the other magazine after the photosensitive recording paper 25 is completely pulled out from the initially selected magazine. The plural conveying roller pairs disposed along the main passage 24 convey the paper sheet 35, which has been cut by the cutters 30a and 30b, through the back-printing section 18, the skew-correcting section 19, the exposure section 20, the receiver section 21, the sorter section 22 and the carrying section 23 in this order.
The back-printing section 18 has a back-printing head 37 which records print information, such as a photography date, a print date, a frame number, various IDs and the like, on the back (an opposite side of the recording surface) of the paper sheet 35.
The skew-correcting section 19 is constituted of a resist roller pair 39 and the plural conveying roller pairs disposed at the front and rear of the resist roller pair 39. The resist roller pair 39 corrects an inclination of the paper sheet 35 so as to prevent misalignments in an angle and an exposure position of the paper sheet 35 in the exposure section 20. Any known methods can be used for correcting the skew using the resist roller pair 39. For instance, the methods disclosed in Japanese Patent Laid-Open Publication Nos. 4,602,778 and No. 11-349191 can be applied.
The exposure unit 20 is constituted of an exposure unit 41, feed roller pairs 42 and 43, and the like. The exposure unit 41 includes a known laser printer and an image memory (not shown). In the image memory, image data sent from the image processing device 12 is stored. The laser printer exposes the image on the paper sheet 35 by scanning the recording light (the laser light), which is modulated according to the image to be recorded, in a main-scanning direction perpendicular to the sub-scanning direction. Nip rollers of the feed roller pairs 42 and 43 are switchable between a nip position, in which the paper sheet 35 is nipped, and a release position in which the paper sheet 35 is released. The nip position and the release position of each nip roller are switched when a position sensor (not shown) detects a leading end or a trailing end of the paper sheet 35. Thereby, it becomes possible to prevent velocity fluctuations in conveying the paper sheet 35 during the exposure.
The receiver section 21 has plural roller pairs for retaining a leading end of the paper sheet 35 which is conveyed from the exposure section 20 after the exposure, and conveys the paper sheet 35 toward the downstream in the conveying direction with the same velocity as that in the exposure section 20. Each roller pair in the receiver section 21 is constituted of a drive roller and a nip roller which is releasable. The nip roller releases the paper sheet 35 during the exposure. When the exposure of the trailing end of the paper sheet 35 is completed, the nip roller moves to the nip position, and nips and conveys the paper sheet 35 to the sorter section 22.
The sorter section 22 sorts the paper sheet 35, which has been conveyed in the single line, into plural lines according to the sheet size while conveying the paper sheet 35 at a predetermined first velocity. For instance, when the paper sheet 35 is of a normal or small size, the sorter section 22 sorts the paper sheet 35 into two lines. When the paper sheet 35 is of a large size, which cannot be conveyed in parallel, the sorter section 22 conveys the paper sheet 35 in the single line without sorting. The carrying section 23 conveys the paper sheet 35, which is conveyed from the sorter section 22, to the processor 14 at a second velocity corresponding to a processing speed of the processor 14.
The processor 14 is constituted of a processing section 46, a drying section 47, a passage changing section 48, a rearranging section 49, a sorter 50 and the like. The paper sheet 35 conveyed from the printer 13 is conveyed in parallel in the processor 14 along the main passage 24 indicated by the alternate long and short dash line in
In the processing section 46, a developing bath 52, a bleaching-fixing bath 53 and a washing bath 54 are disposed in this order from the upstream. Predetermined amounts of a developing solution 52a, a bleaching-fixing solution 53a and a washing solution 54a are stored in the developing bath 52, the bleaching-fixing bath 53 and the washing bath 54 respectively. In each bath 52, 53 and 54, a paper conveying rack 55 is loaded. In each paper conveying rack 55, plural conveying roller pairs 58 are disposed at predetermined intervals. The conveying roller pair 58 is constituted of a flat roller 56 and a projection roller 57 which will be described later. To make a photographic print, the paper sheet 35 is sequentially conveyed in parallel through each bath 52-54 by the conveying roller pair 58 for developing, fixing and washing. When there is a possibility that the projection roller 57 may cause unevenness in developing, the projection roller 57 can be replaced with a flat roller of the same size.
The drying section 47 is disposed in an upper section of each bath 52-54, and is constituted of a belt and a ventilation duct (not shown). The ventilation duct supplies dry air heated by a heater (not shown) to the paper sheet 35 conveyed on the belt. Thereby, wash water, which is deposited on the paper sheet 35 when washed in the washing bath 54, is removed. The dried paper sheet (the photographic print) 35 is conveyed to the passage changing section 48 which is disposed above the drying section 47 (see
The passage changing section 48 conveys the paper sheet 35 of the normal size, which is conveyed in parallel, to the rearranging section 49. When the paper sheet 35 of the large size is conveyed, the passage changing section 48 switches the passage to a tray 60 disposed in a downstream of a sub-passage 24a.
The rearranging section 49 rearranges the paper sheet 35 of the normal size conveyed in parallel to the single line. The rearranging section 49 is set in a replaceable manner according to the processing capacity of the photographic printing system 10. For instance, the rearranging section 49 is replaced with the one with faster rearranging speed, the one which does not perform rearranging or the like according to the photographic printing system 10. The sorter 50 outputs the plural paper sheet 35 conveyed from the rearranging section 49 in each print job.
As shown in
The flat roller 56 is constituted of a roller shaft 65 and a rubber roll 66 attached to the roller shaft 65. The roller shaft 65 is rotatably retained in the paper conveying rack 55 through the bearing section 63. The roller shaft 65 can be formed of any metal or resin material as long as the material is chemical-resistant (corrosion-resistant) to the developing solution 52a, the bleaching-fixing solution 53a and the washing solution 54a. Further, a width of the rubber roll 66 is longer than that of the passage along which the paper sheet 35 is conveyed in parallel. The rubber roll 66 can also be formed of any resin material as long as the material is chemical-resistant to the developing solution 52a, the bleaching-fixing solution 53a and the washing solution 54a. In the embodiment, the roller shaft 65 is formed of SUS 316, and the rubber roll 66 is formed of a silicone rubber, for instance.
The projection roller 57 has a skewer-like shape. The projection roller 57 is constituted of a roller shaft 68, roller pieces 70, pins 71 (see
In the embodiment, the projection roller 57 is formed in the skewer-like shape by fixing the roller pieces 70 to the roller shaft 68 at certain intervals. However, the projection roller 57 can be formed in other configurations. For instance, a length of the roller piece 70 is extended in the width direction so that the projection roller 57 may have a similar shape to the flat roller 56. However, in that case, an outer diameter (a length from a shaft center of the roller shaft 68 to an outer circumferential surface of an elastic layer 79 which will be described later) may vary in an axial direction of the roller shaft 68. For that reason, it is preferable to form a roller piece 70 with a short width and fix plural roller pieces 70 to the roller shaft 68. The number of the roller pieces 70 to be fixed to the roller shaft 68 is not particularly limited, and may be arbitrarily increased or decreased according to the width of the paper sheet 35 to be conveyed.
As with the roller shaft 65, the roller shaft 68 is formed of any metal or resin material with the chemical resistance to the developing solution 52a, the bleaching-fixing solution 53a and the washing solution 54a. In the embodiment, the roller shaft 68 is formed of SUS 316. The roller shaft 68 has pin holes 74 (see
As shown in
The core 78 is formed of a coating section 78a, on which the elastic layer 79 is coated and formed, and a spacer section 78b which restricts a movement of the roller piece 70 in an axial direction of the roller shaft 68 (in a direction of the rotation center line C) when attaching the roller piece 70 to the roller shaft 68. The core 78 is formed of a so-called injection molding in which heated and melted resin material (modified polyphenylene ether) is injected, cooled and solidified in a mold (not shown). At that time, gas generated by the injection molding may be deposited on the outer peripheral surface of the core 78. The deposited gas weakens the adhesive strength between the outer peripheral surface of the core 76 and the primer layer 80 which will be described later. Accordingly, the adhesive strength between the elastic layer 79 and the outer peripheral surface of the core 76 is reduced. To prevent the reduction of the adhesive strength, it is preferable to perform a blasting on the surface of the coating section 78a of the core 78 before forming the elastic layer 79 by coating molding. The blasting makes the outer peripheral surface of the core 78 rough and increases an adhesive area thereof. Accordingly, the adhesive strength is improved.
The resin material for forming the core 78 should have the chemical resistance to the developing solution 52a, the bleaching-fixing solution 53a and the washing solution 54a, and heat resistance for preventing deformations and a secondary shrinkage which may be caused by the heat which is generated when the elastic layer 79 is formed by coating molding. In the embodiment, VESTORAN (produced by Daicel Degussa, Ltd.) is used as the resin material.
Further, in the embodiment, when the core 78 is formed by the injection molding, a pin groove 82, in which the pin 71 is engaged, is formed in an opening 77a which is formed in a left edge portion of the fitting hole 77 (see
Since the projections 69 are formed on the outer peripheral surface of the elastic layer 79, it is preferable that the elastic layer 79 is formed of a vulcanized rubber or the like which is chemical-resistant to the developing solution 52a, the bleaching-fixing solution 53a and the washing solution 54a and whose hardness is not so high. In the embodiment, the elastic layer 79 is formed of the silicone rubber (produced by Dow Corning Toray Co., Ltd.) with the hardness of about 50 degrees. The projections 69 on the outer peripheral surface of the elastic layer 79 is also formed of the soft silicone rubber so that it becomes possible to prevent projection marks on the paper sheet 35 caused by deformation of the projections 69 when the paper sheet 35 is nipped between the flat roller 56 and the projection roller 57.
In the embodiment, each projection 69 is aligned in the direction of the rotation center line C to form a projection line. The projection line is arranged at a constant pitch in a circumferential direction of the elastic layer 79. Adjacent projection lines in the circumferential direction are staggered with respect to the rotation center line C to form a zigzag. Thereby, it becomes possible to prevent the projection marks on the leading end of the paper sheet 35 caused by the projections 69 partly pressing the paper sheet 35, which will be described later. Further, it becomes possible to keep the contact condition and the contact pressure of the paper sheet 35 constant. The arrangement pattern of the projections 69 is not limited to the examples shown in
Further, in the embodiment, the shape and the height of each projection 69 are adjusted in such a way that the projections 69, which are in the position for nipping the paper sheet 35, are deformed, and the projections 69, which are not in the position for nipping the paper sheet 35, contact the flat roller 56 (see
The elastic layer 79 is formed by coating molding on the outer peripheral surface of the coating section 78a of the core 78 as described above, and adhered to the outer peripheral surface of the coating section 78a through the primer layer 80. In the embodiment, the blasting is performed to the core 78 which is formed by the injection molding. Thereafter, the primer is coated to the coating section 78a to form the primer layer 80. The primer layer 80 is formed of a silicone-based primer (produced by Shin-Etsu Silicone, Ltd.) which is chemical-resistant. The core 78, which is formed with the primer layer 80, is set as a core in a mold 84 for forming the elastic layer as shown in
In
The positioning block 88 is formed in a shape to be fitted in the pin groove 82 formed in the opening 77a of the core 78. To set the core 78 coated with the primer layer 80 in the mold 84, the positioning block 88 is fit in the pin groove 82 first. Then, the positioning block 88 and the core 78 are set in the bottom mold 87. Thereafter, the top mold 86 and the bottom mold 87 are joined. Thus, the core 78 is set in the mold 84 in such a way that the pin groove 82 is set in the predetermined direction, that is, the core 78 is positioned in the same position in the circumferential direction. Thereby, the phase of the arrangement of the projections 69 formed on the outer peripheral surface of each roller piece 70 is automatically aligned when the roller pieces 70 are attached to the roller shaft 68, which will be described later.
After setting the core 78 in the mold 84, the heated and the melted silicone rubber is injected through the injection hole 91. Thereafter, the silicone rubber is cooled and solidified to form the elastic layer 79 on the coating section 78a of the core 78. Thus the roller piece 70 is formed. The outer peripheral surface of the coating section 78a and the elastic layer 79 are adhered through the primer layer 80 by the heat generated by forming of the elastic layer 79 by coating molding. When the silicone rubber is solidified, the top and the bottom molds 86 and 87 are separated, the roller piece 70 is taken out from the mold 84 and the flash and the like are removed. Even if there is PL flash on the tips of the projections 69 caused by the PL between the top and the bottom molds 86 and 87, such PL flash has little effect on the paper sheet 35, since the projections 69 are deformed while conveying the paper sheet 35. In the embodiment, the mold 84 is constituted of the top and the bottom molds 86 and 87. However, to facilitate the separation of the molds, the mold 84 may be configured with four or more molds by further dividing the top and the bottom molds 86 and 87.
Thus, when producing the roller piece 70, the primer layer 80, which is chemical-resistant, is formed on the coating section 78a on the core 78, and the elastic layer 79 is formed on the primer layer 80. Thereby, the core 78 and the elastic layer 79 are adhered and integrated through the primer layer 80. Accordingly, the tightening force of the elastic layer 79 is prevented from relaxing due to swelling and stretching caused by the stress at the conveyance unlike the projection tubes. As a result, the slipping of the elastic layer 79 is prevented when conveying the paper sheet 35. Further, since the core 78 and the elastic layer 79 are not directly adhered by the chemical bond, but through the primer layer 80, the uniform adhesive strength is secured regardless of the surface condition of the coating section 78a of the core 78.
Although processes to form the elastic layer 79 by coating molding on the core 78 are necessary in the embodiment, the conventional processes, in which the core 78 is inserted into the projection tube (not shown), are omitted. Accordingly, the working efficiency is significantly improved. Further, since each projection 69 is arranged in the designed position by integrally forming the elastic layer 79 and the core 78, it becomes possible to prevent the deviations of the projections 69 from the designed positions occurred in the above conventional processes.
After forming the predetermined number of roller pieces 70, each roller piece 70 is attached to the roller shaft 68 one by one. Hereinafter, referring to
Before attaching the first roller piece 70, a first pin 71 is engaged in the pin hole 74 formed on the left end side of the roller shaft 68 as shown in
When the slide movement of the first roller piece 70 is completed, the second pin 71 is engaged in the second pin hole 74, and the second roller piece 70 is attached to the right end of the roller shaft 68. Then, the second roller piece 70 is slid to the left along the roller shaft 68 until the second pin 71 is engaged in the second pin groove 82 in the same manner as the first roller piece 70. Thereby, the first pin 71 and the second roller piece 70 restrain the movement of the first roller piece 70 in the axial direction (the direction of the rotation center line C) of the roller shaft 68, and thus the first roller piece 70 is fixed to the roller shaft 68. Hereinafter, the roller piece 70 is fixed to the roller shaft 68 one by one in the same manner.
As shown in
In the embodiment, the core 78 is placed in the mold 84 in the predetermined position in the circumferential direction when the elastic layer 79 is formed by coating molding on the core 78. Therefore, the phase of the arrangement of the projections 69 on each roller piece 70 is automatically aligned only by engaging the pin 71 in the pin groove 82. Further, in the embodiment, the projections 69 on each roller piece 70 is formed in such a way that the projection lines, in which the projections 69 are aligned in the direction of the rotation center line C of the core 78, are arranged in the zigzag with the constant pitch in the circumferential direction of the elastic layer 79. Accordingly, it becomes possible to keep the entry angle constant throughout the leading end of the paper sheet 35 when the paper sheet 35 enters between the flat roller 56 and the projection roller 57. Further, the contact condition and the contact pressure between the paper sheet 35 and the projection roller 57 are kept constant throughout the paper sheet 35 in the width direction.
Next, the operation of the photographic print system 10 of the above configuration is described. As shown in
After the exposure, the paper sheet 35 is conveyed to the sorter section 22 through the receiver section 21. When the paper sheet 35 is of the normal or small size, the sorter section 22 sorts the paper sheet 35 into two lines. When the paper sheet 35 is of the large size, which cannot be conveyed in parallel, the sorter section 22 conveys the paper sheet 35 in the single line without sorting. In the embodiment, the paper sheet 35 of the normal size is used. After being sorted into two lines, the paper sheet 35 is conveyed to the processor 14 through the carrying section 23.
In the processor 14, the paper sheet 35 is subject to processing such as developing, fixing and washing in this order through baths 52-54 respectively, while being nipped and conveyed by the conveying roller pair 58, which is constituted of the flat roller 56 and the projection roller 57, disposed in each bath 52-54. In the embodiment, each roller piece 70, which is to be attached to the roller shaft 68 of the projection roller 57, is formed by coating the elastic layer 79 on the core 78 through the primer layer 80. As a result, the slipping of the roller piece 70, which is caused by the stress relaxation or slight swelling of the elastic layer 79 in the processing solution, are prevented when the paper sheet 35 is conveyed. Accordingly, the failures in conveying the paper sheet 35 are prevented. Further, the uniform adhesive strength is secured regardless of the surface condition of the coating section 78a of the core 78.
Further, the processes for producing the roller piece 70 are increased since the elastic layer 79 is formed by coating molding on the core 78. However, the working efficiency is substantially improved since the processes for inserting the core 78 into the projection tube (not shown) become unnecessary. Furthermore, since the core 78 is no longer inserted into the projection tube (not shown) by manual work, the tearing of the projection tube caused by inserting the core 78 into the projection tube, or the variations in the outer diameter of each roller piece 70 in the direction of rotation center line C are prevented. Thus, yields in manufacturing the projection roller 57 and the quality stability are improved at the same time.
In the embodiment, each projection 69 is aligned to form projection lines in the direction of the rotation center line C. The projection lines are arranged at the constant pitch in the zigzag. Further, the projections 69 of each roller piece 70 attached to the roller shaft 68 are phase-coherent. Accordingly, the entry angle of the leading end of the paper sheet 35 between the projection rollers 56 and 57 of the conveying roller pair 58 can be kept constant throughout the leading end of the paper sheet 35. Thereby, the projection marks, which are caused by partly pressing the leading end of the paper sheet 35 by the projections 69, are prevented. Further, since the contact condition and the contact pressure between the paper sheet 35 and the projection roller 57 are kept constant throughout the width direction of the paper sheet 35, the unbalance in the conveying force of the conveying roller 58 and the changes in the roll alignment are restricted. Accordingly, the skew of the paper sheet 35 is prevented.
After being developed, fixed and washed in the baths 52-54, the paper sheet 35 is conveyed to the drying section 47. In the drying section 47, the dried air heated by the heater is supplied to the paper sheet 35 to remove the wash water deposited on the paper sheet 35. The dried paper sheet 35 is conveyed to the passage changing section 48. Since the paper sheet 35, which is conveyed in parallel, is of the normal size, the passage changing section 48 conveys the paper sheet 35 to the rearranging section 49. The rearranging section 49 rearranges the parallel conveying line into the single line and conveys the paper sheet 35 to the sorter 50. The sorter 50 outputs the plural paper sheets 35 conveyed from the rearranging section 49 according to each print job.
In the embodiment, the core 78 is formed of the modified polyphenylene ether which is the thermoplastic resin. However, other material, which is chemical- and heat-resistant, can be used for forming the core 78. For instance, as shown in Table 1 below, the core 78 can be formed of one of polyamide, polyphenylene sulfide or polypropylene, or a copolymer copolymerized from at least two of the above materials. Further, the core 78 can be formed of thermosetting resin such as phenol, or metal material such as SUS316, titanium, hastelloy and inconel. When the metal material is used for forming the core 78, the roller shaft 68 and the core 78 can be formed integrally by forming steps in the roller shaft 68. When the core 78 and the roller shaft 68 are separately formed, it is preferable to form the core 78 by cutting processing, metal injection molding (MIM) or lost-wax molding.
In the embodiment, the elastic layer 79 is formed of the vulcanized rubber (the silicone rubber). However, it is possible to use other chemical-resistant material for forming the elastic layer 79, such as hydrogenated styrenic thermoplastic elastomer or olefinic thermoplastic elastomer with the hardness of approximately 50 degrees as shown in Table 1 below.
In the embodiment, the core 78 and the elastic layer 79 are adhered through the primer layer 80. However, the present invention is not limited to the embodiment. For instance, as shown in the Table 1 below, when the core 78 is formed of the modified polyphenylene ether, which is the thermoplastic resin, and the elastic layer 79 is formed of the silicone rubber, the core 78 and the elastic layer 79 are directly adhered through the chemical bond at an interface between the thermoplastic resin and the silicone rubber caused by coating the elastic layer 79 on the peripheral surface of the core 78 without the use of the primer layer 80.
Further, when the elastic layer 79 is formed by the thermoplastic elastomer, which has good adherence to the core 78 formed of the thermoplastic resin, it is also possible to directly adhere the core 78 and the elastic layer 79 through the chemical bond without the use of the primer layer 80. For instance, as shown in
In the embodiment, the circumferential rotation of the roller piece 70 is prevented by forming the pin groove 82 in each roller piece 70 (the core 78) and engaging the pin 71, which is attached to the roller shaft 68, in the pin groove 82. However, the present invention is not limited to the embodiment. It is also possible to prevent the circumferential rotation of the roller piece 96, for instance, by using a roller shaft 95 with a D-shaped section instead of the roller shaft 68 (see
To attach the roller piece 96 to the roller shaft 95, the first E-ring 72 is attached to the ring-groove 75 on the left end side of the roller shaft 95 as shown in
Further, for instance, as shown in
To attach the roller piece 101 to the roller shaft 100, as shown in
Further, as shown in
When the first roller piece 103 is completely slid and stopped, the second roller piece 103 and after are attached in the same manner to engage the convex section 104 in the concave section 105 of the previously attached roller piece 103. When the last roller piece 103 is attached, a stopper 109 formed with the convex section 104 is attached and fixed to the right end side of the roller piece 103. The slide movement of each roller piece 103 in the direction of the rotation center line C and the circumferential rotation of each roller piece 103 is restrained by the stoppers 107 and 109. Thus, all the roller pieces 103 are completely fixed to the roller shaft 106.
In the embodiment, the projection roller 57 (the conveying roller pair 58) are disposed in each bath 52-54. However, the present invention is not limited to the embodiment. The projection roller 57 can be disposed in arbitrary areas along the main passage 24 and the sub passage 24a, or in each section constituting the photographic printing system 10. Further, the present invention is not limited to the projection roller 57 used in the photographic printing system 10. It is also possible to use the projection roller in various conveying roller pairs for conveying various sheets such as thin metal sheet, paper, film and the like.
Although the present invention has been described with respect to the preferred embodiment, the present invention is not to be limited to the above embodiment but, on the contrary, various modifications will be possible to those skilled in the art without departing from the scope of claims appended hereto.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-265791 | Sep 2004 | JP | national |
