BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a sheet treating apparatus for use in a recording apparatus or the like for recording images on sheet film. 
     2. Related Background Art 
     In a laser imager for recording on film an image signal obtained by the use of a diagnosing apparatus such as CT or MRI, the image signal inputted is first modulated into the intensity of a laser beam, and then this laser beam is applied to the film and the film is sensitized in conformity with the density of the image to thereby effect recording. Subsequently, the sensitized film is developed by a developing apparatus, whereby an image having light and shade conforming to the image signal is obtained on the film. High harmony is required of film for medical treatment images according to the prior art and therefore, film having silver salt emulsion applied thereto is sensitized with intensity conforming to an image to thereby effect recording, and the film is subjected to the so-called wet type developing process in which the film is immersed in developing liquid and fixating liquid for a predetermined time to thereby effect a developing process. 
     Such a wet type developing process, however, uses chemical liquids such as developing liquid and fixating liquid and is therefore cumbersome in treatment. Also, these chemical liquids become deteriorated and unusable when a predetermined process is carried out and therefore, it is necessary to interchange them suitably. The chemical liquids after used need be disused, and there is the inconvenience that the waste liquids produced at such time cause environmental problems. 
     So, there has been proposed a so-called dry type silver salt system which is similar to the wet type developing process in using film having silver salt emulsion applied thereto, but applies a laser beam to the film to effect recording, and thereafter carries out a heating process to thereby develop the film. An example of such dry type silver salt system is disclosed in Japanese Patent Application Laid-Open No. 53-34515. Also, various kinds of heat developing apparatuses for use in such dry type silver salt system have heretofore been proposed, and an example of them is one disclosed in Japanese Patent Publication No. 55-28927 or U.S. Pat. No. 5,411,825. It is possible to couple such a heat developing apparatus to a laser imager as described in U.S. Pat. No. 5,210,616 and effect recording and development by the use of film of the above-described dry type silver salt type instead of wet type film. 
     FIG. 10 of the accompanying drawings shows the construction of a laser image using such a dry type silver salt system. A supply magazine  2  and a receive magazine  3  are provided in parallel in a recording apparatus  1 , and an optical unit  4  for applying a laser beam L downwardly is provided above the receive magazine  3 . A heat developing apparatus  6  having a developing roller  5  is provided on the left side of the recording apparatus  1 , and this heat developing apparatus  6  is formed with an opening  6   a  for discharging film F therethrough. The solid line in FIG. 10 indicates the conveyance path of the film F. 
     The unrecorded film F in the supply magazine  2  passes along the conveyance path and recording by the laser beam L is effected on the film F below the optical unit  4 . Further, this film F is conveyed to the heat developing apparatus  6 , is developed by the developing roller  5  and is discharged from the opening  6   a  in the heat developing apparatus  6 . 
     However, when such a heat developing apparatus  6  is used in the laser imager, it is necessary to heat the recorded film F for a predetermined time, e.g. 10 seconds, and therefore, when the recorded film F is to be heated and developed while it is conveyed, if the throughput of recording, i.e., the number of sheets of film capable of being treated within a unit time, is taken into account, the speed of conveying the film cannot be made very low and the film must be heated over a very long distance. Therefore, the diameter of the rotatable developing roller  5  is made considerably large and thus, the dimensions of the entire apparatus becomes large. 
     Further, the film F is heated and developed while being twined around the developing roller  5 , and this also leads to the problem that the film F becomes curled. 
     There is also the problem that particularly the characteristic of the laser which is a recording light source is varied by the heat generated from the heat developing apparatus  6  or the temperature of the film F during recording rises and when recording is to be continuously effected, the recording characteristic changes between the film F recorded at first and the film F recorded later. 
     SUMMARY OF THE INVENTION 
     The present invention has as an object thereof to find out optimum disposition relationship between units to thereby provide a compact and highly accurate sheet treating apparatus and method. 
     One preferred form of the sheet treating apparatus according to the present invention has containing means containing a plurality of sheets therein, recording means for effecting recording on the sheets, a substantially straight path for conveying the recorded sheets, and heat developing means for heat-developing the sheets in the path, and is characterized in that the containing means and the recording means are disposed under the heat developing means. 
     Another preferred form of the sheet treating apparatus according to the present invention has containing means for containing a plurality of sheets therein, recording means for effecting recording on the sheets, a substantially straight path for conveying the recorded sheets, and heat developing means for heat-developing the sheets in the path, and is characterized in that the containing means and the straight path are disposed so that the straight path and the sheets in the containing means may be substantially parallel or substantially orthogonal to one another. 
     A preferred form of the film treating method of the present invention is characterized in that recording is effected on film at a recording position and the recorded film is heat-developed above the recording position without being curled. 
     Further objects and preferred forms of the present invention will become apparent from the following detailed description of some embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows the construction of a first embodiment of the present invention. 
     FIG. 2 is a plane view of an optical unit. 
     FIG. 3 is a cross-sectional view of the conveying roller of a developing portion. 
     FIG. 4 is a cross-sectional view of the guide plate of the developing portion. 
     FIG. 5 is a cross-sectional view of a portion around a fan. 
     FIG. 6 is a cross-sectional view of a portion around an opening. 
     FIG. 7 shows the construction of a second embodiment of the present invention. 
     FIG. 8 shows the construction of a third embodiment of the present invention. 
     FIG. 9 shows the construction of a fourth embodiment of the present invention. 
     FIG. 10 shows the construction of an example of the prior art. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will hereinafter be described in detail with respect to some embodiments thereof shown in FIGS. 1 to  9 . 
     Referring to FIG. 1 which shows the construction of a first embodiment of the present invention, an image recording apparatus  11  has its interior covered as a dark space with a cover  12 , and an opening  12   a  for film F to pass therethrough is formed in the upper portion of the cover  12 . The interior of the cover  12  is partitioned by partition walls  13  and  14  to thereby prevent a light beam having entered the opening  12   a  in the cover  12  from further entering the interior. The partition wall  14  is formed with two openings  14   a  and  14   b  for the air to flow therethrough. 
     A removably insertable supply magazine  15  containing piled unused films F therein is contained horizontally in the cover  12 . This supply magazine  15  is formed with an opening  15   a  for taking out the films F therethrough. Further, a lid portion  16  for opening and closing the opening  15   a  is attached to the supply magazine  15  so that when the lid portion  16  is closed, the supply magazine  15  may have its interior kept as a dark space. Each film F has only its underside formed into a silver salt emulsion surface, and a latent image may be recorded by a minute laser beam being applied to the silver salt emulsion surface, and by this latent image being developed, an image can be formed to thereby accomplish recording. 
     A plurality of suckers  17  capable of sucking the films F are provided above the opening  15   a  in the supply magazine  15  in the direction of depth, and these suckers  17  are movable to the positions a to d of FIG.  1 . At the left of the position c of the suckers  17 , there are provided a pair of conveying rollers comprising conveying rollers  18  and  19 , and bulged portions for sandwiching the film F are formed at a plurality of locations in the direction of depth of the conveying roller  18 , and the conveying roller  18  is retractable to the dot-and-dash line position of FIG. 1 by a mechanism, not shown. 
     Further, at the left of the conveying rollers  18  and  19 , there are provided in succession a conveying path comprising guide plates  20  and  21 , a pair of sub-scanning rollers comprising sub-scanning rollers  22  and  23 , and a pair of sub-scanning rollers comprising sub-scanning rollers  24  and  25 . The sub-scanning rollers  22  to  25  are adapted to have highly accurate servo applied thereto by a drive source and power transmitting means, not shown, and to be rotated at a uniform speed. 
     On the other hand, an optical unit  27  having its interior covered as a dark space with a cover  26  is provided below the supply magazine  15 , and this optical unit  27  is adapted to be capable of applying a laser beam L from an opening  26   a  formed in the left side of the cover  26  to between the sub-scanning roller  23  and the sub-scanning roller  25  to thereby effect main scanning. 
     Referring now to FIG. 2 which is a plane view of the optical unit  27 , lenses  29 ,  30  and a rotational polygon mirror  32  rotatable at a predetermined speed by a motor  31  are arranged in succession in the direction of emission of a laser source  28  emitting the laser beam L modulated in conformity with image data to be recorded. Further, the laser beam L reflected by the rotatable polygon mirror  32  may pass through lenses  33  and  34 , whereafter it may be sectorally scanned between the sub-scanning rollers  23  and  25  and be applied to the film F. 
     If the scanning angle α of the rotatable polygon mirror  32  is too great, the shape of the laser beam L will be varied by the influence of the aberrations or the like of the optical system or the deviation of the focus of the optical system will become great and therefore, it is preferable that the scanning angle α be of the order of 30 to 40 degrees or less. Accordingly, when for example, film F of 35×43 cm is mainly scanned in the direction of 35 cm and the effective width W of this film F is 33 cm, the distance A of the path along which the laser beam L reflected by the rotatable polygon mirror  32  passes until it arrives at the film F is about 45 to 50 cm, which is equal to or greater than the length of the film F in the direction of movement thereof. 
     Also, in FIG. 1, a conveying path comprising guide plates  35  and  36  and a pair of conveying rollers comprising conveying rollers  37  and  38  are provided in succession below the sub-scanning rollers  24  and  25 , and the conveying roller  37  is retractable to a dot-and-dash line position. Further, at the right of the conveying rollers  37  and  38 , there are provided in succession a conveying path comprising guide plates  39  and  40 , a pair of conveying rollers comprising conveying rollers  41  and  42 , a conveying path comprising guide plates  43  and  44 , a pair of conveying rollers comprising conveying rollers  45  and  46 , a conveying path comprising guide plates  47  and  48 , and a pair of conveying rollers comprising conveying rollers  49  and  50 . 
     At the left of the conveying rollers  49  and  50 , there is provided a heat developing portion  51 , which is covered with a partition wall  52  made of a material of good heat insulation, and in the right and left sides of this partition wall  52 , there are formed openings  52   a  and  52   b , respectively, for the film F to pass therethrough. At the left of the opening  52   a  in the partition wall  52 , there are provided in succession a pair of conveying rollers comprising conveying rollers  53  and  54 , a conveying path comprising guide plates  55  and  56 , a pair of conveying rollers comprising conveying rollers  57  and  58 , a conveying path comprising guide plates  59  and  60 , and a pair of conveying rollers comprising conveying rollers  61  and  62  so that the film F can be conveyed to the opening  52   b  in the partition wall  52  along the conveying paths by these pairs of conveying rollers. 
     Referring to FIG. 3 which is a cross-sectional view of the conveying roller  54 , the conveying roller  54  is rotatably supported by frames  66  and  67  through bearings  63 ,  64  and a bearing holder  65  having its central portion opened to form a circular ring shape. The left end portion  54   a  of the conveying roller  54  is reduced in diameter, and a gear  68  connected to drive means, not shown, is mounted on this left end portion  54   a . The interior of the conveying roller  54  is formed into a cavity  54   b , in which a heater  69  is inserted through the bearing holder  65  and the bearing  64 . 
     Further, as shown in FIG. 1, a temperature sensor  70  having its detecting portion adapted to contact with the surface of the conveying roller  54  is provided on the lower portion of the conveying roller  54 . The conveying rollers  58  and  62 , like the conveying roller  54 , are also rotatable by the drive means, and heaters are inserted in the internal cavities  58   a  and  62   a  thereof, and temperature sensors  71  and  72  are provided on the lower portions thereof so as to contact with the surfaces of the conveying rollers  58  and  62 , respectively. 
     Referring to FIG. 4 which is a cross-sectional view of the guide plate  55 , a heater  74  containing a resistance wire  73  therein is attached to the guide plate  55 , and temperature sensors  75  for detecting the temperature of the heater  74  are provided on the opposite sides of the guide plate  55 . Although not shown, the guide plates  56 ,  59  and  60 , like the guide plate  55 , are also provided with temperature sensors. 
     At the left of the opening  52   b  in the partition wall  52 , there are provided in succession a pair of conveying rollers comprising conveying rollers  76  and  77 , a conveying path comprising guide plates  78  and  79 , and a pair of conveying rollers comprising conveying rollers  80  and  81  so that the film F conveyed to the conveying rollers  80  and  81  may be discharged outwardly through the opening  12   a  in the cover  12 . 
     In FIG. 1, two fans  82  are provided on the front surface or the back surface of the cover  12 . FIG. 5 is a cross-sectional view of the fan  82  and a portion around it. The fan  82  is adapted to be capable of discharging the internal air through the opening  12   b  formed in the cover  12 . The fan  82  is covered with two partition walls  83  and  84  to thereby prevent any extraneous light beam from entering the interior. On the other hand, an opening  12   c  for introducing the air is formed in the lower portion of the cover  12 , and as shown in FIG. 6, the opening  12   c  is covered with two partition walls  85  and  86  so as to prevent any extraneous light beam from entering the interior through the opening  12   c . Further, the partition wall  14  is formed with two openings  14   a  and  14   b  so as not to hamper the flow of the air in the cover  12 . 
     When recording is to be effected, upon closing of a power source switch, not shown, the conveying rollers  54 ,  58 ,  62  and the guide plates  56 ,  60  are heated by the heaters  69  and  74  therein. The temperatures of the conveying rollers  54 ,  58 ,  62  and the guide plates  56 ,  60  are detected by the temperature sensors  70  to  72  and  75 , and the surface temperatures of the conveying rollers  54 ,  58 ,  62  and guide plates  56 ,  60  are controlled so as to be within a predetermined range by control means, not shown. When the temperatures of the conveying rollers  54 ,  58 ,  62  and guide plates  56 ,  60  reach a predetermined temperature, display means, not shown, displays that recording is possible. 
     Next, when instructions for effecting recording are given by instructing means, not shown, the suckers  17  are moved from the position a to the position b and such the uppermost one of the film F in the supply magazine  15 . At this time, the conveying roller  18  has already been moved to a solid-line position and further, the suckers  17  are moved to the position c and the leading end of the film F is nipped by and between the conveying rollers  18  and  19 , whereafter the suckers  17  releases their sucking of the film F and are retracted to the position d. Thereby, the film F is separated from the suckers  17 , and when the conveying rollers  18  and  19  are rotated, the film F is conveyed leftwardly downwardly along the guide plates  20  and  21  and is nipped by and between the sub-scanning rollers  22  and  23 . 
     When the film F is nipped by and between the sub-scanning rollers  22  and  23 , the conveying rollers  18  and  37  are moved to their dot-and-dash line positions, whereafter the sub-scanning rollers  22  to  25  begin to rotate at the same speed. When the leading end of the film F is nipped by and between the sub-scanning rollers  24  and  25 , the laser source  28  of the optical unit  27  emits the laser beam L modulated by an image signal, and this laser beam is deflected by the rotatable polygon mirror  32 , whereby main scanning is effected. At the same time, sub-scanning is effected by the sub-scanning rollers  22  to  25 , and the leading end of the film F is moved downwardly rightwardly along the guide plates  35  and  36 . As the recording further progresses, the trailing end of the film F moves along the guide plates  20  and  21 , but since the guide plates  20  and  21  are provided smoothly from the vicinity of the conveying rollers  18 ,  19  to the vicinity of the sub-scanning rollers  22 ,  23 , any shock which will affect the recording is not applied to the film F. 
     The laser source  28  completes the application of the laser beam L immediately before the trailing end of the film F leaves the sub-scanning rollers  22  and  23 , and thereafter the conveying roller  37  is moved to a solid-line position and is rotated, whereby the film F is conveyed rightwardly. Hereupon, the conveying rollers  41 ,  42 ,  45 ,  46 ,  49  and  50  begin to be rotated to thereby convey the film F upwardly along the guide plates  43 ,  44 ,  47  and  48 , and the film F is nipped by and between the conveying rollers  53  and  54  in the heat developing portion  51  through the opening  52   a  in the partition wall  52 . 
     Subsequently, the conveying rollers  53 ,  54 ,  57 ,  58 ,  61  and  62  are rotated to thereby convey the film F leftwardly along the guide plates  55 ,  56 ,  59  and  60 , and the film F is nipped by and between the conveying rollers  76  and  77 . At this time, the film F is heated and developed by the heaters  69  and  74  of the conveying rollers  54 ,  58 ,  62  and guide plates  56 ,  60 . The conveying rollers  76 ,  77 ,  80  and  81  are then rotated to thereby convey the developed film F along the guide plates  78  and  79 , and the film F is discharged through the opening  12   a  in the cover  12 . When recording is to be continuously effected, a similar operation can be repeated. Or if the suckers  17  are again moved to the position b to start the separation of the next film F when the trailing end of the film F leaves the sub-scanning rollers  24  and  25 , the throughput of the film F will be improved. 
     During recording, the fan  82  is rotated to introduce the air through the opening  12   c  in the cover  12  and discharge the air through the opening  12   b . Thus, the air warmed by the heat developing portion  51  does not flow downwardly from the partition wall  14  and the temperature around the scanning position can be kept substantially constant. 
     Also, when the temperatures of the conveying rollers  54 ,  58 ,  62  and guide plates  56 ,  60  detected by the temperature sensors  70  to  72  during development deviate from a predetermined range, if the film F is passing them, the next film F is stopped short of the conveying rollers  53  and  54  after that film F has passed the conveying rollers  61  and  62 , and the conveyance of the film F is resumed after the temperatures of the conveying rollers  54 ,  58 ,  62  and guide rollers  56 ,  60  again fall within the predetermined range. 
     While in the present embodiment, the heaters are attached to all of the guide plates  55 ,  56 ,  59  and  60 , the heaters may be attached to only some of the guide plates, or if a heater is mounted in at least one of the conveying rollers  54 ,  58  and  62 , the heaters of the guide plates  55 ,  56 ,  59  and  60  can be eliminated. 
     The heaters may be attached to some of the rollers  53 ,  57 ,  61  same as  54 ,  58 ,  62 . 
     According to the present embodiment, the film is heated and developed by the heat developing means having a straight path and therefore, the film is not curled by development. When the film is to be developed by such straight developing means, it is necessary to heat the film at a predetermined temperature, e.g. for 10 seconds, and when an attempt is made to convey film of 35 cm×43 cm common as film for medical treatment in parallelism to a side of 43 cm and develop a film within 20 seconds, the heating path of the heat developing means will become long, and if the heat developing means is disposed laterally of the recording apparatus as shown in FIG. 10, the installation area of the apparatus will become large. 
     So, in the present embodiment, the supply magazine, the optical unit and the heat developing means are disposed horizontally and so as to vertically overlap one another, whereby there is achieved an apparatus which is small in floor installation area. Also, the conveyance path of the film is made into a lateral U-shape, whereby further downsizing of the apparatus is achieved. Also, the film is conveyed in one direction from the first to the last and need not be reversed in direction on its way, the conveyance path and the conveyance structure are simple. 
     Also, according to the present embodiment, the conveyance path from the recording position to the heat developing means is made longer than the length of the film in the direction of conveyance, whereby the leading end of the film does not enter the heat developing means during the recording on the film and therefore, the quality of recorded image is not deteriorated by the shock when the film is nipped by and between the rollers of the heat developing means. 
     Further, since the heat developing device  11  is provided on the uppermost portion of the apparatus, the heat radiated therefrom does not adversely affect the supply magazine  15  and the optical unit  27 . In the present embodiment, the partition wall  14  is further provided to thereby further reduce the influence of heat. 
     In FIG. 7 which shows the construction of a second embodiment of the present invention, the same reference numerals as those in FIG. 1 designate the same members. This second embodiment differs only in arrangement from the first embodiment. In the first embodiment, the emulsion surface of the film F faces downwardly when the film F passes through the heat developing portion  51  and therefore, due to the influence of grarity, the emulsion contacts with the guide plates  56  and  60  and depending on the property of the emulsion, the emulsion surface of the film F may be damaged, but by arrangement being done as in the second embodiment, the upper surface of the film F is the emulsion surface in the heat developing portion  51  and thus, the film F is not damaged. 
     Referring to FIG. 8 which shows the construction of a third embodiment of the present invention, it shows only the conveyance path of the film F. In the second embodiment, the suckers  17  contact with the emulsion surface of the film F and effect sucking and therefore, depending on the kind of the emulsion and the material of the suckers  17 , fog may be created in those portions of the film F which are contacted by the suckers  17 , but in the present embodiment, the suckers contact with the back surface opposite to the emulsion surface of the film F and therefore, no fog is created in the film F. 
     Referring to FIG. 9 which shows the construction of a fourth embodiment of the present invention, the heat developing portion  51  is disposed substantially in a vertical direction. This leads to the advantage that as compared with the first embodiment, the conveyance path becomes simple and the height of the image recording apparatus  11  can be made small. 
     The heat developing means requires an adiabatic member or the like and therefore is considerably heavy, but in the present embodiment, this weight need not be supported by the recording portion, and this leads to the advantage that the weight resisting structure of the recording portion can be simplified. 
     In the present embodiment, it is difficult for the heat radiated from the heat developing means to affect the supply magazine and the optical unit and further, the influence of the heat is further reduced by the partition wall  14 . 
     In FIG. 9, the supply magazine and the optical unit are disposed horizontally and the heat developing means is disposed so as to be vertical, but alternatively, the supply magazine and the optical unit may be disposed substantially vertically and the heat developing means may be disposed substantially horizontally (so as to be upper or lower) while keeping these positional relations. 
     As a further alternative, the supply magazine, the optical unit and the heat developing means may all be disposed so as to be substantially vertical or slantly while keeping these relative relations of FIG. 1 or  7 , or  8 .
A sheet treating apparatus has a container containing a plurality of sheets therein, a recorder for effecting recording on the sheets, a substantially straight path for conveying the recorded sheets and a heat-developer for heat-developing the sheets in the path. The container and/or the recorder are disposed under the heat-developer, are vertically overlapped with one another, and may be vertically overlapped with the heat-developer. The container and the straight path are disposed so that the straight path and the sheets in the container may be substantially parallel or substantially orthogonal to one another.