Abstract:
The present invention provides an image recording apparatus having a path of travel of a recording material, said apparatus comprising: an exposure section subjecting the recording material to exposure processing so as to form a latent image on the recording material; a heat-developing section subjecting the recording material to heat processing so as to carry out development, which is disposed downstream of the exposure section; a cooling section for cooling the recording material, which is disposed downstream of the heat-developing section; and a storage section for storing the recording material, which is disposed downstream of the cooling section; wherein the heat-developing section includes an exit portion for the recording material, which is provided on the path and disposed at an upper portion of the heat-developing section such that hot air is able to escape from an inside of the heat-developing section.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image recording apparatus in which a sheet-shaped recording material is subjected to heat-developing processing. 
     2. Description of the Related Art 
     As shown in  FIG. 8 , a conventional image recording apparatus  100  is generally provided with a filter  106  and a discharge opening  110 , wherein air in a substantially closed space such as a heat-developing section  102  and a cooling section  104 , is filtered by the filter  106 , and then, discharged by the fan  108  to the outside of the image recording apparatus  100  via a discharge opening  110 . 
     However, the temperature of a sheet storage portion  112  is raised due to exhaust heat from the cooling section  104 . Thus, sheet-shaped recording materials  101 , which have been stored in the sheet storage portion, tend to be adversely affected. 
     Because of the need for gradual cooling of the sheet-shaped recording material  101 , which has been discharged from the heat-developing section  102 , a structure has been suggested in which the cooling rollers  120  are disposed in a zigzag manner at the cooling section  104 , each roller being formed by a pipe  116  that is made of aluminum and a felt  118  that is wound around the pipe  116 , as shown in FIG.  9 . 
     In such a case in which the felt  118  is spirally wound around the pipe, a seam or clearance  122  is inevitably formed between one felt edge and the other felt edge, small though it may be. This causes uneven cooling of the sheet-shaped recording material, resulting in development irregularities. 
     Referring again to  FIG. 8 , in the conventional image recording apparatus  100 , the heat-developing section  102  has an exit opening  114 , through which the sheet-shaped recording material  101  is discharged. The exit opening  114  is located at a position approximately in the middle of the heat-developing section  102 . 
     Thus, volatile components in the air, which are emitted from the heat-developed sheet-shaped recording material, inevitably and problematically are trapped in an upper area within the heat-developing section  102 . 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an image recording apparatus that can eliminate the aforementioned problems of the prior art. 
     In order to achieve the object described above, according to one aspect of the present invention, there is provided an image recording apparatus having a path of travel of a recording material, said apparatus comprising: (I) an exposure section subjecting the recording material to exposure processing so as to form a latent image on the recording material; (II) a heat-developing section subjecting the recording material to heat processing so as to carry out development, said heat-developing section being disposed downstream of the exposure section; (III) a cooling section for cooling the recording material, said cooling section being disposed downstream of the heat-developing section; and (IV) a storage section for storing the recording material, said storage section being disposed downstream of the cooling section; (V) wherein the heat-developing section includes an exit portion for the recording material, said exit portion being provided on the path and disposed at an upper portion of the heat-developing section such that hot air is able to escape from an inside of the heat-developing section. 
     According to another aspect of the present invention, there is provided an image recording apparatus having a path of travel of a recording material, said apparatus comprising: (I) an exposure section subjecting the recording material to exposure processing so as to form a latent image on the recording material; (II) a heat-developing section subjecting the recording material to heat processing so as to carry out development, said heat-developing section being disposed downstream of the exposure section; (III) a cooling section for cooling the recording material, said cooling section being disposed downstream of the heat-developing section; and (IV) a storage section for storing the recording material, said storage section being disposed downstream of the cooling section; (V) wherein the cooling section includes a plurality of cooling rollers, which are disposed along the path, at least part of said cooling rollers having had electrostatic implantation performed thereon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic general structural view of an image recording apparatus according to an embodiment of the present invention. 
         FIG. 2  is a perspective view of a cooling section of the image recording apparatus according to the embodiment. 
         FIG. 3  is a perspective view of a cooling roller with piles electrostatically implanted therein. 
         FIG. 4  is an explanatory diagram of electrostatic implanting processing. 
         FIG. 5  is a view of a filter having a honeycomb-shaped cross section. 
         FIG. 6  is a view of another filter having a grille-shaped cross section. 
         FIG. 7  is a view of yet another filter having a corrugated fiber-board shaped cross section. 
         FIG. 8  is a schematic general structural view of a conventional image recording apparatus. 
         FIG. 9  is a perspective view of a conventional cooling roller. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of an image recording apparatus according to the present invention will be described in detail below on the basis of the drawings. 
     As shown in  FIG. 1 , the image recording apparatus  10  is provided with an exposure section  11 , where a latent image is formed on a sheet-shaped recording material  12 . 
     A heat-developing section  14  is disposed downstream of the exposure section  11 . The heat-developing section  14  is a dry-developing type section, which carries out developing processing by heating the sheet-shaped recording material  12 . The entire heat-developing section  14  is covered by a casing  16 . The region between a first pair of rollers  13  of the heat-developing section  14  and the final stage of the exposure section  11  (the conveying direction downstream side end portion of a guide plate  11 A) has a small dimension, which is at least shorter than the conveying direction length of the sheet-shaped recording material  12 . 
     Thus, the leading end of the sheet-shaped material  12 , while being scan-exposed in the exposure section  11 , enters into the heat-developing section  14 . 
     The casing  16  of the heat-developing section  14  has an arc-shaped path for the sheet-shaped recording material. Three developing units  18  are disposed along this arc. Each developing unit  18  is formed by a heating plate  20  and a plurality of rollers  22 . One surface of the heating plate  20  (the surface facing the sheet-shaped recording material  12 ) is formed as an arc-shaped heating surface  20 A. The plurality of rollers  22 , together with the heating plate, nip the sheet-shaped recording material  12 . The heating plates  20  are heated to predetermined temperatures by respective heating sources (not illustrated). The heating plates  20  are provided with respective heat-insulating covers  26 . As needed, controlled temperatures of the heating plates  20  can be changed independently of one another. Further, the heat distribution within each developing unit  18  can be adjusted. Moreover, the rollers  22  receive driving force from respective driving means (not illustrated) and rotate at a constant velocity. 
     In this way, the sheet-shaped recording material  12 , which is inserted into the insertion portion of the developing unit  18 , is heated while being conveyed at a predetermined conveying speed. The sheet-shaped recording material  12  receives the amount of heat necessary for development and is heat-developed, until it is discharged. 
     An exit portion  25  is provided so as to correspond to the final roller  24  of the heat-developing section  14 . The exit portion  25  is for discharging the sheet-shaped material  12  from the heat-developing section  14  and is formed at an upper portion of the heat-developing section  14 . In this way, the exit portion  25  of the heat-developing section  14  is provided at the upper portion of the heat-developing section, but not at a middle portion thereof. Thus, volatile components can be prevented from being trapped in the heat-developing section  14 . As a result, it is difficult for the sheet-shaped recording material  12  to be contaminated and for electronic parts to corrode. 
     A cooling section  28  is disposed downstream of the heat-developing section  14 . 
     As show n in  FIG. 2 , the cooling section  28  is provided with a plurality of cooling rollers  30 , which support the sheet-shaped recording material  12 . Each cooling roller  30  is formed by a pipe  31 , which is made of a material such as aluminum, having the property of being easy to heat and easy to cool. The cooling rollers  30  function to take away heat from the sheet-shaped recording material  12  by contacting the sheet-shaped recording material  12 . 
     Thus, by passing the cooling section  28 , the sheet-shaped recording material  12  is cooled and then discharged. 
     Details of the cooling rollers  30  will be described later. 
     Here, as shown in  FIG. 1 , the cooling section  28  possesses a gradual cooling section  34 , which is at the earlier stage of the cooling section  28 , and a rapid cooling section  36 , which is at the latter stage thereof. The gradual cooling section  34  is a region in which the sheet-shaped recording material  12 , which has just been developed and has a relatively high temperature (120° C.), is cooled gradually. By passing through the gradual cooling section  34 , the temperature of the sheet-shaped recording material  12  is lowered to approximately 70° C. This is preferably a temperature which is lower than the glass transition point of the sheet-shaped recording material  12 . 
     As shown in  FIG. 3 , each of the cooling rollers  30  of the gradual cooling section  34  has piles  32 , which are electrostatically implanted in the pipe  31  to serve as a brush member. The length of each pile  32  is preferably within the range of about 0.1 mm˜about 4.0 mm, and more preferably, within the range of about 0.5 mm˜about 2.5 mm. The thickness of each pile is preferably within the range of about 1.5 denier˜about 30.0 denier, and more preferably, within the range of about 2.0 denier˜about 7.0 denier. Further, as a material for the piles  32 , it is possible to employ a rayon, a nylon, a 66-nylon, a polyester, Nomex and the like. Among these, the 66-nylon is most preferable. 
     A description will be given of the outline of electrostatic implantation of the piles  32 . 
     As shown in  FIG. 4 , when a pile  32  is provided in the electric field E, the pile  32  receives a rotational force F from polarization, so that the pile is oriented along electric field lines. Here, by providing a pipe  31  in the electric field E and by controlling a flight path of the pile  32  by an electrode to which voltage is applied, the pile  32  flies toward the pipe  31  due to an electrostatic force generated from the electric field E. Further, by applying an adhesive  33  on the pipe  31  in advance, when one end of the pile  32  abuts the pipe  31 , the pile  32  is fixed at its end by means of the adhesive. For example, a water-base acrylic adhesive, an oil-base acrylic adhesive, a water-base epoxy adhesive, an oil-base adhesive or the like is used as a material of the adhesive  33 . In every case, the piles are capable of being flocked or implanted perpendicular to the surface of the pipe  31 . Thus, if the lengths of the piles  32  are constant, the protruding lengths of the flocked piles should be constant as well. 
     Post-processing involves filling an appropriate material by utilizing brushing processing and adhesive spray. 
     In this way, with static electricity flock transplantation technology, the pipe  31  can be uniformly covered with the piles  32 . Consequently, gradual cooling processing for uniform cooling can be achieved. 
     The rapid cooling section  36  (see  FIG. 1 ) is a region in which the temperature of the discharged, sheet-shaped recording material  12  is lowered rapidly. By passing through the rapid cooling section  36 , the temperature of the sheet-shaped recording material  12  lowers to approximately 45° C. This is a temperature at which the sheet-shaped recording material can be safely handled by an operator. 
     Further, as shown in  FIGS. 1 and 2 , a cover  50 , which covers the entire apparatus, is disposed above the cooling section  28  and the heat-developing section  14 . A discharge opening  46  is formed at a right-hand side of the cover  50  in FIG.  1 . The sheet-shaped recording material  12 , which has been cooled in the cooling section  28 , is discharged and stored on a sheet storage portion  44  provided on the upper surface of the cover  50 . 
     A ventilation passage  48  is formed above the cooling section  28  and the heat-developing section  14  and below the cover  50 . A plurality of cooling fins  38  are provided in the ventilation passage  48 , each of which hangs down from an inside surface of the cover  50 . 
     Further, a filter  40  and a plurality of air-cooling fans  42  (serving as an air discharging means) is disposed downstream of the ventilation passage  48 . Duty ratio, i.e. ratio of active time to a predetermined time under on-off control, of the air-cooling fans  42  is raised during heat-developing processing of the sheet-shaped recording material  12 . 
     When the air-cooling fans  42  operate, an airflow is formed, flowing from the discharge opening  46  through the ventilation passage  48  and the filter  40  to the outside of the air-cooling fans  42 , as indicated by arrows A, B, C and D. Due to the airflow being formed underneath the sheet storage portion  44 , the temperature of the air, which is raised by heat emission, is prevented from being trapped underneath the sheet storage portion  44 . Thus, the rise in temperature of the sheet storage portion  44  can be controlled. As a result, adverse effects to the sheet-shaped recording material  12  can be prevented. 
     In this way, at the cooling rollers  30 , the heat dissipating effect is accelerated by the cooling fins  38 , and heat is forcibly dissipated by the air-cooling fans  42 . Accordingly, the cooling rollers  30  can be maintained substantially at their initial temperature when the sheet-shaped recording material  12  is not present thereat. Further, as described above, the stream of air can restrain temperature rise of the sheet storage portion  44 . 
     As shown in  FIG. 5 , the filter  40  disposed between the cooling fins  38  and the air-cooling fans  42  has a honeycomb-shaped cross section. The filter  40  filters the air to absorb odors of particles of benzene series, ammonium series and the like suspended in the air. Air thus filtered is then discharged by the air-cooling fans  42  to the outside (see FIG.  1 ). 
     Further, as shown in  FIGS. 1 and 2 , the gradual cooling section  34  has a cover  35  formed therein. Part of the gradual cooling section  34  is separated by the cover  35  such that air flowing in the ventilation passage  48  is prevented from directly contacting the upstream side (or the separated part) of the gradual cooling section  34  and the sheet-shaped recording material  12 , which has just been discharged from the heat-developing section. Namely, the sheet-shaped recording material  12 , which has been softened in the heat-developing section  14 , can be prevented from being rapidly cooled by the airflow. As a result, rapid cooling-induced image irregularities can thereby be prevented. 
     Operation of the above-described embodiment will be described hereinafter. 
     At the exposure section  11 , a latent image is formed on a sheet-shaped recording material  12 . During the continued formation of the latent image, the leading end of the sheet-shaped recording material  12  enters into the insertion portion of the heat-developing section  14 . 
     At the heat-developing section  14 , the sheet-shaped recording material  12  is conveyed in a substantial arc shape and is heat-developed by the heat of the plural developing units  18 . The sheet-shaped recording material  12 , which has been heat-developed, is discharged from the exit portion  25  disposed at the upper portion of the heat-developing section  14 . As described above, with this arrangement, volatile components can be prevented from staying in the heat-developing section  14 , and therefore, it is difficult for the sheet-shaped recording material  12  to be contaminated and for electronic parts to corrode. 
     At the cooling section  28 , the sheet-shaped recording material  12 , which has been fed-out from the heat-developing section  14 , is grippingly conveyed by the cooling rollers  30 . First, the sheet-shaped recording material  12 , which has been heated to 120° C., is cooled by the gradual cooling section  34  at a gradual rate to approximately 70° C. Thereafter, the sheet-shaped recording material is rapidly cooled to approximately 45° C. by the rapid cooling section  36 . Thus, the temperature of the sheet-shaped recording material  12  discharged from the cooling section  28  can be lowered to a temperature which does not cause problems for handling by an operator. 
     As described above, in the present embodiment, each cooling roller  30  includes the pipe  31  with at least a base layer (or adhesive layer) in which the piles  32  are electrostatically implanted. Unlike the prior art, the present invention does not possess an arrangement in which a cooling roller is formed by a pipe and a felt sheet, which felt sheet is spirally wound on the pipe with a seam formed by both edges thereof. On the contrary, the cooling rollers  30  of the present embodiment are formed by using static electricity flock transplantation technology such that the base layers have no seam. Accordingly, uneven cooling at the cooling rollers  30  can be prevented. As a result, the occurrence of development irregularities can be effectively prevented. 
     Further, particularly at the rapid cooling section  36 , if the heat taken away from the sheet-shaped recording material  12  remains thereat, the cooling effect deteriorates. However, by providing the cooling fins  38  and the air-cooling fans  42 , the cooling section  28  can always be maintained substantially at its initial temperature. 
     At the sheet storage portion  44 , the sheet-shaped recording material  12 , which has been discharged from the discharge opening  46  via the cooling section  28 , is stored on the upper surface of the cover. 
     The air-cooling fans  42  form an air stream which flows from the discharge opening  46  through the ventilation passage  48  to the outside of the apparatus. As described above, because of the airflow being formed underneath the sheet storage portion  44 , air, which is raised in temperature by heat emission, is prevented from staying at the underside of the sheet storage portion  44 . Thus, the rise in temperature of the sheet storage portion  44  can be controlled. As a result, deterioration of the sheet-shaped recording material  12  can be prevented. 
     The filter  40  filters an air flowing in the ventilation passage  48  to absorb odors of particles of benzene series, ammonium series and the like suspended in the air. Thus, discharging of a foul odor to the outside of the apparatus can be prevented. 
     The cover  35  prevents direct contacting of the air to the sheet-shaped recording material  12  which has just been discharged from the heat-developing section  14 . Namely, the very same sheet-shaped recording material  12 , which has been softened in the heat-developing section  14 , can be prevented from being rapidly cooled by the airflow. As a result, image irregularities, which may be caused by rapid cooling, can effectively be prevented. 
     In the above-described embodiment, when heat-developing the sheet-shaped recording material, the duty ratio for the air-cooling fans is raised. In this case, for example, a temperature sensor, such as a thermistor, may be provided in the cooling section in order to control the duty ratio of the cooling fans. 
     It should be noted that, in the above embodiment, a detailed description is given of a case in which the filter has a honeycomb-shaped cross section. However, the configuration of the filter is not limited to this structure. For example, a filter with a grille-shaped cross section, as shown in  FIG. 6 , and a filter with a corrugated fiber-board shaped cross section as shown in  FIG. 7  may also be utilized. 
     Further, in the above-described embodiment, all of the cooling rollers, which are disposed in the cooling section  28 , are of one type in which the piles are electrostatically implanted on the base layers of the cooling rollers. However, the present invention is not thus limited. For example, if necessary, only the rollers enclosed in the cover  35  may be flocked. Alternatively, only the rollers disposed in the gradual cooling section can be of this type, if necessary. 
     As is described above, an image recording apparatus according to the present invention has excellent effects in that the rise in temperature at the sheet storage portion can be controlled so as to prevent deterioration of the sheet-shaped recording material, in that the occurrence of development irregularities which may be caused by unevenness of cooling can be prevented, and in that the volatile components can be prevented from being trapped in the heat-developing section.