Patent Publication Number: US-6222608-B1

Title: Image forming device for forming image on roll of photosensitive/pressure-sensitive recording medium

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image forming device for forming an image on a roll of photosensitive/pressure-sensitive recording medium. 
     2. Description of the Related Art 
     There has been known an image forming device for forming an image on a roll of photosensitive/pressure-sensitive recording medium that includes microcapsules with dye precursor. In this kind of image forming device, the roll of recording medium is cut down to a predetermined output size by a cutter, which is located at a cutting position. Then, an exposure unit exposes the cut recording medium to a light of a certain wavelength. The microcapsules selectively harden by reacting to the light, and a latent image is formed in the recording medium accordingly. Then, a pair of pressing rollers of a developing unit apply pressure to the recording medium sandwiched therebetween. As a result, unhardened microcapsules are ruptured, and dye precursor exudes from the ruptured microcapsules, thereby developing an image corresponding to the latent image. Afterwards, the image is thermally fixed by a fixing unit. 
     However, when the recording medium is cut down to the output size, adhesive materials included in the recording medium exude from the cut surface and adhere onto the cutter. The adhesive materials will gradually accumulate on the cutter until eventually the cutter becomes unable to cut the recording medium. 
     Also, mechanical stress is applied to the recording medium during the cutting operation. This ruptures the microcapsules around the portion of the recording medium, so that the cutting portion of the cut recording medium may be developed in an undesirable color, thereby degrading quality of the developed image. 
     In order to overcome this problem, there has been proposed an image forming device including the cutting unit shown in FIG.  1 . In this image forming device, an exposure unit  850  exposes a cut portion of a recording medium  810  with white light from the above. Then the recording medium  810  is cut along the exposed cut portion by the cutter  840 . More specifically, as shown in FIG. 1, a linear light source  820  emits white light. The light source  820  extends to a greater length than the width of the recording medium  810 . The light emitted from the light source  820  reaches the recording medium  810  through a slit  830  having a predetermined width. Because the cutter  840  cannot be positioned directly below the light source  820 , the cutter  840  is located at a position remote from the exposure unit  840 . Therefore, the recording medium  810  is transported to a cutting position after the exposure operation. The recording medium  810  is placed between a pair of blades  840   a ,  840   b , and cut along the exposed cutting portion. Because the microcapsules at the exposed cutting portion of the recording medium  810  are all hardened, the microcapsules will not be undesirably ruptured at the cutting operation. Therefore, a high quality image can be provided. 
     However, the recording medium  810  may be inaccurately transported from the through hole to the cutting position because the feeding mechanism slips or for some other reason. If the cutting portion is exposed to only a narrow width, then when the recording medium  810  is inaccurately transported, it may be cut in front or behind the exposed cutting portion. Therefore, the exposed cutting portion must be formed to have a certain wide width. However, the an image cannot be formed on the exposed cutting portion, so the recording medium  810  is wasted when the cutting portion is formed wide. 
     Also, because the recording medium  810  is first exposed with a light, transported to the cutting position, and then cut by the cutter  840 , the overall operation takes a relatively long time. Also, because the exposure unit  850  and the cutter  840  are positioned separated from each other, the image forming device has a relatively large size. 
     Moreover, because a recording medium has a certain thickness, a large shock is applied to the developing unit when the recording medium is first inserted in between the pressing rollers and later discharged from between the pressing rollers. This large shock can produce a loud noise, and can also affect the developing unit, thereby reducing the life of the developing unit. 
     In order to overcome this problem, Japanese Patent-Application Publication No. HEI-1-300256 discloses a mechanism for cutting down a recording medium at a predetermined angle with respect to a feed direction of the recording medium. That is to say, the recording medium is cut perpendicular to a surface of the recording medium, but at a slant with respect to a widthwise direction of the recording medium. When the recording medium cut in this manner is inserted in between the pressing rollers, a leading edge of the recording medium is gradually inserted in between the pressing rollers, so that the shock is less than in the situation described above. The same is the case when the rear edge of the recording medium is discharged from between the pressing rollers. 
     However, in this case, when the recording medium is cut at a slant in this manner, the surface area of the portion sandwiched between the pressing rollers will change gradually when the edge portions enter or leave the pressing rollers. Therefore, the pressure per unit surface area on the leading and rear edge portions of the recording medium changes in association with distance that the recording medium is transported. Microcapsules are ruptured in varying amounts depending on pressure applied, so that the color of the developed image will be uneven. 
     Also, the amount of compression energy that accumulates on the rear edge of the recording medium is much greater than at positions where the width is wider. As a result, the recording medium can fly out of the developing unit with a popping or other an unusual sound. Therefore, pressing development can be sometimes insufficient. 
     SUMMARY OF THE INVENTION 
     It is an objective of the present invention to overcome the above-described problems and to provide a photosensitive/pressure-sensitive image forming device including a cleaning unit for cleaning that cutting unit. 
     It is another objective of the present invention to provide a photosensitive/pressure-sensitive image forming device capable of forming a high quality image without undesirable color developed therein or unevenness in color. 
     It is also another objective of the present invention to provide an economical and small-sized photosensitive/pressure-sensitive image forming device capable of quickly performing an image forming operation without wasting recording medium. 
     It is still another objective of the present invention to provide a photosensitive/pressure-sensitive image forming device wherein shock generated when a recording medium enters and leaves a developing unit is reduced, and wherein energy does not accumulate at rear edges of the recording medium, so the recording medium does not fly out of the developing unit. 
     In order to achieve the above and other objectives, there is provided an image forming device including a cutting unit that cuts a recording medium and a cleaning member that cleans the cutting unit when the cutting unit comes into contact with the cleaning member. 
     There is also provided an image forming device including a cutting unit that cuts a recording medium and a supply unit that supplies the cutting unit with one of an agent that prevents a foreign material from clinging to the cutting unit and an agent that dissolves an adhesive material contained in the recording medium. 
     Also, there is provided an image forming device including a transport unit that transports a photosensitive/pressure-sensitive recording medium in a first direction, a frame extending in a second direction perpendicular to the first direction, a cutting unit that is slidably supported on the frame and cuts down the photosensitive/pressure-sensitive recording medium by sliding along the frame, and an exposure unit that radiates white light onto a portion of the photosensitive/pressure-sensitive recording medium. The exposure unit is attached to the cutting unit such that when the cutting unit slides in the second direction, the exposure unit moves with and ahead of the cutting unit while radiating the white light onto the portion of the photosensitive/pressure-sensitive recording medium. 
     Further, there is provided an image forming device including an exposure unit, a cutting unit, and a transport unit. The exposure unit exposes an optical image having an exposure region onto a photosensitive/pressure-sensitive recording medium positioned at an exposure position to form a latent image corresponding to the optical image in the photosensitive/pressure-sensitive recording medium. The latent image has an image region. The photosensitive/pressure-sensitive recording medium having an elongated shape. The cutting unit cuts the photosensitive/pressure-sensitive recording medium at a portion within the image region down into a predetermined output size. The transport unit transports the photosensitive/pressure-sensitive recording medium from the exposure position toward the cutting unit. 
     Still further, there is provided an image forming device including a transporting unit that transports in a first direction a pressuresensitive recording medium having a thickness in a second direction perpendicular to the first direction and a cutting unit that cuts the pressure-sensitive recording medium in a third direction perpendicular to the first direction and at a slant with respect to the second direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The particular features and advantages of the invention as well as other objects will become more apparent from the following description taken in connection with the accompanying drawings, in which: 
     FIG. 1 is a plan view showing a cutting unit and an exposing unit of a conventional photosensitive/pressure-sensitive image forming device; 
     FIG. 2 is a plan view showing a configuration of a printer according to a first embodiment of the present invention; 
     FIG. 3 is a cross-sectional view of a photosensitive/pressure-sensitive recording medium used in the printer of FIG. 2; 
     FIG. 4 is a plan view of a cutting unit according to a first embodiment of the present invention; 
     FIG. 5 is a cross-sectional view of the cutting unit of FIG. 4; 
     FIG. 6 is a block diagram of a control unit of the printer of FIG. 2; 
     FIG. 7 is a perspective view schematically showing a cutting operation of the cutting unit of FIG. 4; 
     FIG. 8 is a plan view of a cutting unit according to a modification of the first embodiment; 
     FIG. 9 is a plan view showing a configuration of a printer according to a second embodiment of the present invention; 
     FIG. 10 is a plan view showing a cutting unit of the printer of FIG. 9; 
     FIG. 11 is a cross-sectional view of the cutting unit of FIG. 10; 
     FIG. 12 is a cross-sectional view of a cutting unit according to a first modification of the second embodiment; 
     FIG. 13 is a cross-sectional view of a cutting unit according to a second modification of the second embodiment; 
     FIG.  14 ( a ) is a cross-sectional view of an example of a slide cutter; 
     FIG.  14 ( b ) is a front view of the slide cutter of FIG.  14 ( a ); 
     FIG. 15 is a cross-sectional view of another example of a slide cutter; 
     FIG.  15 ( b ) is a front view of the slide cutter of FIG.  15 ( a ); 
     FIG. 16 is a plan view showing a configuration of a printer according to a third embodiment of the present invention; 
     FIG. 17 is a cross-sectional view of a cutting unit of the printer of FIG. 16; 
     FIG. 18 is a partial side view of a developing unit with a recording medium cut by the cutting unit of FIG. 17; 
     FIG.  19 ( a ) is a cross-sectional view of an example of cutting unit that can be used in the printer of FIG. 16; 
     FIG.  19 ( b ) is a front view of the cutting unit of FIG.  19 ( a ); 
     FIG.  20 ( a ) is a cross-sectional view of another example of cutting unit that can be used in the printer of FIG. 16; 
     FIG.  20 ( b ) is a front view of the cutting unit of FIG.  20 ( a ); 
     FIG.  21 ( a ) is a cross-sectional view of another example of cutting unit that can be used in the printer of FIG. 16; 
     FIG.  21 ( b ) is a front view of the cutting unit of FIG.  21 ( a ); 
     FIG.  22 ( a ) is a cross-sectional view of another example of cutting unit that can be used in the printer of FIG. 16; 
     FIG.  22 ( b ) is a front view of the cutting unit of FIG.  22 ( a ); 
     FIG. 23 is a plan view of a configuration of a printer according to a fourth embodiment of the present invention; 
     FIG. 24 is a block diagram of a control unit of the printer of FIG. 16; 
     FIG. 25 is a plan view indicating image exposure areas; 
     FIG. 26 is a plan view of a recording medium cut in the printer of FIG. 16; 
     FIG.  27 ( a ) is a plan view of a recording medium positioned at a through hole; 
     FIG.  27 ( b ) is an plan view of the recording medium positioned at a cutting position; 
     FIG.  27 ( c ) is an plan view of the recording medium cut at the cutting position; 
     FIG.  27 ( d ) is an plan view of the recording medium returned to the through hole; 
     FIG.  27 ( e ) is an plan view of the recording medium exposed with an optical image; 
     FIG.  28 ( a ) is an plan view of a recording medium positioned at an through hole; 
     FIG.  28 ( b ) is an plan view of the recording medium at a cutting position; 
     FIG.  28 ( c ) is an plan view of a wasted part of the recording medium being cut away; 
     FIG.  28 ( d ) is an plan view of the recording medium transported to a cutting position; 
     FIG.  28 ( e ) is an plan view of the recording medium cut at the cutting position; 
     FIG.  29 ( a ) is an plan view of the recording medium returned to the through hole; 
     FIG.  29 ( b ) is an plan view of the recording medium exposed with an optical image; 
     FIG.  29 ( c ) is an plan view of the recording medium transported to the cutting position; 
     FIG.  29 ( d ) is an plan view of the recording medium with a wasted portion cut off from the recording medium; 
     FIG.  29 ( e ) is an plan view of the recording medium transported to the cutting position; and 
     FIG.  29 ( f ) is an plan view of the recording medium cut down into an output size. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Image forming devices according to preferred embodiments of the present invention will be described while referring to the accompanying drawings. In the following description, the expressions “front”, “rear”, “left”, “right”, “upper”, “lower”, “horizontal, and “vertical” are used throughout the description to define the various parts when the printer is disposed in an orientation in which it is intended to be used. 
     First, a configuration of a photosensitive/pressure-sensitive printer  1  according to a first embodiment of the present invention will be described while referring to FIGS. 2 to  7 . As shown in FIG. 2, the photosensitive/pressure-sensitive printer (hereinafter referred to as “printer”)  1  includes a frame  2 , a cassette  3 , a feed unit  5 , a transfer belt  6 , a cutting unit  7 , a pressing glass  8 , a support  9 , an exposure unit  10 , a sheet edge detection sensor  16 , a developing unit  19 , a fixing unit  20 , and a discharge tray  22 . The frame  2  is formed with a discharge port  2   a . The cassette  3  is formed with an opening  3   a  and detachably mounted to a front side of the printer  1 . The cassette  3  houses an elongated photosensitive/pressure-sensitive recording medium (hereinafter referred to as “recording medium”)  4  wound in a rolled-up condition. 
     The cassette  3 , the feed unit  5 , the sheet edge detection sensor  16 , the support  9 , the developing unit  19 , and the fixing unit  20  are all provided in the frame  2  in this order in a feed direction indicated by an arrow F. A leading portion of the recording medium  4  is drawn out from the cassette  3  through the opening  3   a . The feed unit  5  includes a pair of feed rollers  5   a  and  5   b  for feeding the recording medium  4 . The cutting unit  7  cuts the recording medium  4  down into a predetermined output size. The cutting unit  7  detects a leading edge of the recording medium  4 . The support  9  supports the recording medium  4  thereon at an image exposure operation to be described later. 
     The pressing glass  8  is made in a plate shape from transparent glass that light can pass through. The support  9  is positioned below the pressing glass  8  and provided with a transport belt  6 . The transfer belt  6  is controlled to selectively press against and separate from an under surface of the pressing glass  8 . During a medium transport operation, the transfer belt  6  is separated from the under surface of the pressing glass  8 , and driven to rotate in order to transport the recording medium  4  interposed between the transfer belt  6  and the pressing glass  8 . On the other hand, during an image exposure operation, the transport belt  6  presses the recording medium  4  against the under surface of the pressing glass  8  in order to to keep the recording medium  4  flat. 
     The exposure unit  10  forms an optical image onto the recording medium  4 . The exposure unit  10  includes a light source  11 , such as a halogen lamp, a condenser lens  12 , a liquid crystal panel  13 , a filter member  14 , and a focus lens  15 . The light source  11  emits white light. The condenser lens  12  condenses the white light emitted from the light source  11 . The liquid crystal panel  13  displays an exposure image based on print data. Although not shown, the filter member  14  includes three color filters: red, blue, and green. The filter member  14  is rotatable and so can selectively move the color filters in between the panel  13  and the lens focus lens  15 . 
     White light from the light source  11  passes through the liquid crystal panel  13 , and is formed into an optical image corresponding to the exposure image of the liquid crystal panel  13 . Then, the optical image passes through one of the color filters, and is formed into an optical image having a wavelength that corresponds to a certain optical component, that is, a blue light component, a red light component, or a green light component. A light component of the optical image is determined by the color of the filter which the optical image has passed through. The filter member  14  is controlled to rotate so as to produce an optical component for a desired time duration. The focus lens  15  condenses the optical image to a predetermined focal point distance. When the condensed optical image reaches and irradiates the recording medium  4  through the pressing glass  8 , microcapsules in the recording medium  4  selectively react to the optical image and harden. As a result, a latent image corresponding to the optical image is formed in the recording medium  4 . 
     The developing unit  19  includes a pair of pressing rollers  19   a ,  19   b  for applying pressure to the recording medium  4  in order to develop an image corresponding to a latent image. The developing unit  19  includes an upper roller  19   a  and the lower roller  19   b . The lower roller  19   b  is supported by the frame  2  so as to be capable of selectively contacting and separating from the upper roller  19   a , and urged upwardly by a resilient member (not shown), such as a spring. The developing unit  19  applies pressure to the recording medium  4  by sandwiching between the upper roller  19   a  and the lower roller  19   b  to crush unhardened microcapsules contained in the microcapsules sheet  4 . 
     The fixing unit  20  includes a fixing heater  21  and a pressing roller  20   a . The fixing heater  21  generates heat to increase its temperature to a predetermined temperature. The pressing roller  20   a  urges the recording medium  4  against the fixing heater  21 . When the recording medium  4  formed with the developed image is transported through the fixing unit  20 , neat from the fixing heater  21  thermally fixes the developed image onto the recording medium  4 . In this way, a long lasting image can be formed on the recording medium  4 . 
     The discharge tray  22  is provided on an outer surface of the frame  2  at a position below the discharge port  2   a  for supporting the discharged recording medium  4 . 
     Next, the recording medium  4  will be described while referring to FIG.  3 . As shown in FIG. 3, the recording medium  4  includes a cover sheet  31 , a base sheet  35 , and a mixed layer  34  sandwiched between the cover sheet  31  and the base sheet  35 . The mixed layer  34  includes microcapsules  32 Y,  32 M,  32 C (collectively referred to as “microcapsule  32 ”), and developer  33 . The microcapsules  32 Y,  32 M,  32 C have a polymer wall and contain photosensitive resin and dye precursor. The photosensitive resin is reactive with a certain wavelength optical component, that is, a blue light component, a green light component, or a red light component. The type of dye precursor varies with the type of microcapsule  32 Y,  32 M,  32 C. That is, the microcapsules  32 Y,  32 M,  32 C contain yellow-color dye precursor, magenta-color dye precursor, and cyan-color dye precursor, respectively. The photosensitive resin changes its mechanical strength and hardens when exposed to a corresponding optical component. In this way, a latent image corresponding to an optical image is formed in the recording medium  4 . When, the recording medium  4  with the latent image formed therein is subject to pressure, unhardened microcapsules  32  ruptures, and the dye precursor exudes from the microcapsule  32 . The dye precursor reacts with the developer  33  into a corresponding primary color, that is, yellow, magenta, and cyan. In this way, an image corresponding to the latent image is developed in the recording medium  4 . 
     Specifically, when the recording medium  4  is exposed to a blue light component having a wavelength of about 470 nm, the photosensitive resin of the microcapsules  35 Y, which includes yellow-color dye precursor, hardens. Then, when the recording medium  4  is subject to pressure, the microcapsules  32 M,  32 C which include magenta-color dye precursor and cyan-color dye precursor, respectively, ruptures, but the microcapsules  32 Y do not. As a result, the magenta-color dye precursor and the cyan-color dye precursor exude from the microcapsules  32 M,  32 C, react with the developer  33 , and mix with each other to develop a blue color which is visible through the cover sheet  31 . 
     When the recording medium  4  is exposed to a green light component having a wavelength of about 525 nm, the photosensitive resin of microcapsule  32 M, which includes magenta-color dye precursor, hardens. When the recording medium  4  is subject to pressure, the microcapsules  32 Y,  32 C which include yellow-color dye precursor and cyan-color dye precursor, respectively, rupture, but the microcapsules  32 M do not. As a result, the yellow-color dye precursor and the cyan-color dye precursor exude from the microcapsules  32 Y,  32 C, react with the developer  33 , and mix with each other. As a result, green color is developed and becomes visible through the cover sheet  31 . 
     When the recording medium  4  is exposed to a red light component having a wavelength of about 650 nm exposes, the photosensitive resin of the microcapsule  32 C, which includes cyan-color dye precursor, hardens. When such recording medium  4  is subject to pressure, the microcapsules  32 Y,  32 C which include yellow-color dye precursor and magenta-color dye precursor, respectively, rupture, but the microcapsules  32 M do not. As a result, the yellow-color dye precursor and the magenta-color dye precursor exude from the microcapsules  32 Y,  32 M, react with the developer  33 , and mix with each other. As a result, red color is developed and becomes visible through the cover sheet  31 . 
     When the recording medium  4  is exposed to white light, all of the microcapsules  32  harden. Therefore, non of the microcapsules  32  rupture even when subject to pressure. Therefore, color developing will not take place, and a white-colored upper surface of the base sheet  35  stays visible from above. That is, an image is formed where the color developing takes place, and the upper surface of the base sheet  35  provides a white-color background of a developed image. It should be noted that such color developing is called self coloring, and the surface of the base sheet  35  is called a developed surface. 
     It should be noted that the wall of the microcapsule  32  can be formed gelatin, polyamide, polyvinyl alcohol, or polyisocianate resin. The dye precursor can be triphenylmethan dye precursor or spiropyran. The photosensitive resin can be organic compound including acriloil, such as trimethylolpropanetriachrylate. The polymerization agent may be benzophenon, benzoylalkylether. 
     The developer  33  may be well-known acid developer, such as organic acid, phenolnovolac resin, and inorganic acid including acid white clay, kaolin, acid zinc, and acid titanium. The material for forming the developer  33  may be selected in accordance with the material forming dye precursor. 
     The base sheet  35  can be made of transparent, semitransparent, or opaque sheet, for example, resin film, paper (cellulose), synthetic paper, polyester, and polycarbonate. 
     The recording medium  4  including the microcapsules  32  is easily affected by humidity. When the recording medium  4  is left in a humid place, the recording medium  4  absorbs moisture through the cover sheet  31  and the base sheet  35 . As a result, the photosensitivity of the recording medium  4  may increase as much as 10 times or greater. Therefore, the recording medium  4  needs to be protected from humidity for preventing the photosensitivity from changing. 
     In order to achieve this objective, it is preferable to form the cover sheet  31  and the base sheet  35  from a material having an anti-humidity property, or to apply anti-humidity material over inner or outer surfaces of the cover sheet  31  and the base sheet  35 . Such anti-humidity material may be, for example, optical lens material, such as, amorphous polyolefin. Alternatively, silicon dioxide can be deposited over the surfaces. 
     Also, when the recording medium  4  is exposed to ultraviolet light, the ultraviolet light reaches the microcapsules  32  through the cover sheet  31 , thereby turning the microcapsules  32  a yellowish color. As a result, whiteness and color density of the background of an image can be altered. Therefore, in order to overcome this problem, it is preferable to form the cover sheet  31  from a material having a low ultraviolet light transmittance. Alternatively, such low transmittance material can be applied onto an outer surface or inner surface of the cover sheet  31 . 
     The mixed layer  34  of the medium  4  can be formed by applying a mixture of microcapsules  32 , developer  33 , binder, filler, and viscosity adjuster onto the base sheet  35  using an application roller, a sprayer, a doctor knife, or other suitable tool. 
     As shown in FIG. 3, the recording medium  4  is attached to a cleaning tape  4   a . The cleaning tape  4   a  is formed consecutive with the recording medium  4  and serves as a leader tape of the recording medium  4 . Although not shown in the drawings, a reflection rate detection sensor is provided adjacent to the cutting unit  7 . Because the cleaning tape  4   a  has a different reflection rate than the recording medium  4 , the reflection rate detection sensor can distinguish between the cleaning tape  4   a  and the recording medium  4 . The cleaning tape  4   a  is formed from a PET film containing a number of microcapsules. Each microcapsule contains methyl ethyl ketone which is a solvent capable of dissolving adhesive materials contained in the mixed layer  34  of the recording medium  4 . When the cassette  3  is first mounted in the printer  1 , the printer  1  controls the cutting unit  7  to cut the cleaning tape  4   a  so that adhesive materials clinging to cutting unit  7  is dissolved and removed. 
     Next, the cutting unit  7  according to the first embodiment of the present invention will be described while referring to FIGS. 4 to  7 . As shown in FIG. 4, the cutting unit  7  includes a frame  51 , a holder  54 , a sliding blade  56 , a fixed blade  55 , a driving pulley  59 , a driven pulley  60 , a wire  61 , a gear  62 , a reversible motor  63 , a right sensor  64 , a left sensor  65 , and an optical fiber  40 . 
     The frame  51  extends in right and left directions, and is formed with a through hole  51   a  and a groove  51   b . The through hole  51   a  has a width and a height greater than a width W and a thickness of the recording medium  4 , respectively. The through hole  51   a  is positioned on a sheet feed path of the recording medium  4 , so that the recording medium  4  supplied from the feed unit  5  can pass therethrough. 
     As shown in FIG. 5, the groove  51   b  is defined by an upper surface  51   d  and a lower surface  51   e . Protrusions  51   c  are formed in upper and lower surfaces  51   d ,  51   e  so as to protrude vertically toward each other. The holder  54  is formed with engagement grooves  54   a  at its upper and lower surfaces for engaging the protrusions  51   c . In this way, the holder  54  is slidably supported by the frame  51 . 
     The sliding blade  56  is formed in a disk shape and is freely rotatably supported on a front surface of the holder  54  such that a lower portion of the sliding blade  56  is positioned below the through hole  51   a . On the other hand, the fixed blade  55  is positioned on a lower surface of the through hole  51   a  such that the fixed blade  55  is almost in contact with a blade edge of the sliding blade  56 . 
     The driving pulley  59  and the driven pulley  60  are provided at the right and left sides of the frame  51 , respectively. The driving pulley  59  is connected to the reversible motor  63  via the gear  62  so that a driving force of the reversible motor  63  can be transmitted to the driving pulley  59 . The wire  61  is wound around and extends between the pulleys  59 ,  60 , and ends of the wire  61  are attached to corresponding right and left side surfaces of the holder  54 . With this configuration, when the reversible motor  63  drives the driving pulley  59  to rotate, the holder  54  is moved between a predetermined slide start position and a predetermined slide end position either in a cutting direction indicated by an arrow L or a returning direction indicated by an arrow R depending on the rotation direction of the pulley motor  63 . When the holder  54  slides in the cutting direction L, the recording medium  4  is cut by the sliding blade  56  and the fixed blade  55 . 
     The left sensor  65  and the right sensor  64  are provided at positions adjacent to the driving pulley  59  and the driven pulley  60 , respectively. The left sensor  65  detects the holder  54  reaching the slide end position after the holder  54  slides in the sliding direction L, and outputs a detection signal. On the other hand, the right sensor  64  detects the holder  54  reaching the slide start position after the holder  54  slides in the returning direction R, and outputs a detection signal. 
     The optical fiber  40  has terminals  40   a ,  40   b . The terminal  40   a  is attached to the left side surface of the holder  54  which is facing in the cutting direction L such that a light beam is emitted from the terminal  40   a  in a downward direction perpendicular to the sheet surface of the recording medium  4 . With this configuration, when the holder  54  slides in the cutting direction L, the terminal  40   a  also moves ahead of the holder  54  while exposing the recording medium  4  with a light beam, thereby forming an exposed cutting portion on the recording medium  4 . It should be noted that a width of the exposed cutting portion should be as small as possible in order to minimize the waste amount of wasted recording medium  4 . However, the width has to be wide enough for preventing unexposed microcapsule  32  outside of the exposed cutting portion from being ruptured because of a mechanical stress applied by the fixed blade  55  and the sliding blade  56 . The optical fiber  40  has a length long enough for allowing the terminal  40   a  to move along with the holder  54 . The terminal  40   b  is connected to a light source  42  which is provided in a dead space defined in the casing  2 . 
     As shown in FIG. 6, the printer  1  further includes a central processing unit (CPU)  24  for controlling various processes. The CPU  24  includes an input/output portion, a data communication portion, a calculation portion, a memory portion, and the like. The input/output portion is connected to the sheet edge detection sensor  16 , the right sensor  64 , the left sensor  65 , the exposure unit  10 , the stepping motor  23  and the cutting unit  7 . The data communication portion is connected to an external information processing device  25 . The memory portion includes a recording region for storing a print control routine, control data, print data, such as image data and character data, and control calculation data. The calculation portion executes the print control routine for cutting the recording medium  4  into a predetermined output size, in a manner to be described later, and for forming an image on the recording medium  4 . 
     Next, operation of the printer  1  will be described while referring to FIGS. 2 and 4 to  7 . When the CPU  24  receives an image forming command from the information processing device  25 , the CPU  24  confirms that the holder  54  of the cutting unit  7  is located at the sliding start position based on a detection signal from the right sensor  64 . Then, the stepping motor  23  drives the pair of feed rollers  5   a ,  5   b  to rotate, thereby drawing the recording medium  4  out of the cassette  3  and transporting in the feed direction F. When the sheet edge detection sensor  16  detects a leading edge of the recording medium  4 , the stepping motor  23  controls to transport the recording medium  4  for a predetermined pulses&#39; amount so that the recording medium  4  has an output length between the leading edge and the cutting position of the cutting unit  7 . 
     Next, the light source  42  is turned ON for emitting a light beam through the one terminal portion  40   a  of the optical fiber  40 . The reversible motor  63  drives the driving pulley  59  to rotate. The driving force is transmitted via the wire  61  to slide the holder  54  in the cutting direction L. Accordingly, the one terminal portion  40   a  of the optical fiber  40  and the sliding blade  56 , which are attached to the holder  54 , are also moved in the cutting direction L. At this time, as shown in FIG. 7, the one terminal portion  40   a  of the optical fiber  40  moves ahead of the sliding blade  56  while exposing a light beam to a cutting portion of the recording medium  4 . As a result, the microcapsules  32  at the exposed cutting portion are all hardened. Then, as the cutting blade  56  slides along the exposed cutting portion, the sliding blade  56  and the fixed blade  55  apply a shear stress on the exposed cutting portion, thereby cutting the recording medium  4  at the exposed cutting portion. 
     In this way, even if mechanical stress is applied to the microcapsules  32  in the cutting position at the cutting operation, because the microcapsules  32  within the range of the mechanical stress have all hardened, the microcapsules  32  will not be ruptured. 
     When the left sensor  65  detects the holder  54  at the slide end position, the CPU  24  confirms that the recording medium  4  has been completely cut, and controls the holder  54  to stop sliding. In this way, the recording medium  4  is cut down into the predetermined output size. 
     Next, the CPU  24  controls the transport belt  6  to rotate so as to transport the recording medium  4 . When the recording medium  4  reaches the exposing position, the transport belt  6  stops transporting, and the transport belt  6  is moved toward the pressing glass  8 . As a result, the recording medium  4  is pressed against the pressing glass  8  and kept in a flat condition. It should be noted that the holder  54  is returned to the sliding start position by sliding in the returning direction R by the time the next cutting operation is performed. 
     Next, print data, such as image data and character data, received from the information processing device  25  is output to the liquid crystal panel  13 , and the liquid crystal panel  13  forms an exposure image based on the print data. Then, the exposure unit  10  is turned ON to radiate white light. The white light is condensed by the condenser lens  12 , formed into an optical image corresponding to the exposure image by the liquid crystal panel  13 , and then, formed into an optical image of, for example, a blue light component by penetrating through the blue color filter. Subsequently, the optical image of the blue light component reaches and exposes the recording medium  4  through the pressing glass  8 . Then, the microcapsules  32 Y are hardened, thereby forming a latent image corresponding to the optical image of the blue light component in the recording medium  4 . 
     Then, latent images corresponding to optical images of the red and green light components are formed in the recording medium  4  in the same manner. It should be noted that when the image includes an image region and a frame region, the information processing device  25  previously performs image data processing operation for adding white frame data for forming a white frame latent image around the image region, so that all of the microcapsules  32  in the frame region are hardened. In order to avoid unnecessarily waste of the recording medium  4 , the white frame region should include the exposed cutting portion which has been exposed by the optical fiber  40 . 
     Then, the transport belt  6  releases the recording medium  4  from pressing against the pressing glass  8 , and starts rotating to transport the recording medium  4  with the latent image formed thereon to the developing unit  19 . At the developing unit  19 , the recording medium  4  is transported while sandwiched between the pair of pressing rollers  19   a ,  19   b . Unhardened microcapsules  32  are ruptured and developed. Next, the fixing unit  20  thermally fixes the developed image in the recording medium  4 . Then, the recording medium  4  is discharged through the discharge port  2   a  onto the discharge tray  22 . 
     According to the first embodiment described above, when the recording medium  4  is cut by the sliding blade  54  of the cutting unit  7 , the optical fiber  40  moves ahead of the sliding blade  56  while exposing a cutting position of the recording medium  4  with a light beam. Therefore, a width of the exposing portion can be determined without taking a sheet feed accuracy into consideration. The width of the exposed cutting portion can be minimized, thereby minimizing waste of the recording medium  4 . 
     Further, because the exposure operation and the cutting operation are performed simultaneously, time required to perform overall operations can be reduced. Also, because the exposure and cutting operations are performed at the same location, the image forming device can be reduced in size. 
     Moreover, the light source  42  is provided in a dead space defined in the printer  1 . Therefore, the printer  1  can be formed even smaller. 
     Although, the above-described sliding blade  56  is controlled to slide in the directions L, R, which are perpendicular to the feed direction F, the sliding blade  56  can be controlled to slide any direction intersecting the feed direction F, for example, in a direction slanted with respect to the feed direction F. Also, the cutting unit  7  can be provided with a fixed blade, such as a laser blade, instead of the freely rotatable disk-shaped sliding blade  56 . 
     Further, in the above-described first embodiment, the recording medium  4  is cut only when the holder  54  slides in the cutting direction L. However, by providing a terminal  40   a  of the optical fiber  40  on both right and left surfaces of the holder  54 , the recording medium  4  can be cut when the holder  54  slides in the returning direction R also. 
     Next, a cutting unit  7 ′ according to a modification of the first embodiment will be described while referring to FIG.  8 . As shown in FIG. 8, the cutting unit  7 ′ is similar to the cutting unit  7 . However, a laser beam source  70  is attached on a left surface of the frame  51 , and a reflection mirror  72  is attached on the left side surface of the holder  54 . With this configuration, a laser beam  71  radiated from the laser beam source  70  is reflected by the reflection mirror  72  toward the recording medium  4 , and exposes the cutting portion of the recording medium  4 . 
     Next, a photosensitive/pressure-sensitive printer  101  according to the second embodiment of the present invention will be described while referring to FIGS. 9 to  11 . As shown in FIG. 9, the photosensitive/pressure-sensitive printer (hereinafter referred to as “printer”)  101  is similar to the above-described printer  1  of the first embodiment, except that the printer  101  includes a cutting unit  107 . Therefore, only the cutting unit  107  will be described to avoid a duplication of explanation. 
     As shown in FIG. 10, the cutting unit  107  includes a disk shaped rotary blade  156 , a rectangular fixed blade  155 , a holder  154  formed with grooves  156   a , and a frame  151  formed with a through hole  151   a , cleaning members  170 , a wire  161 , a pair of rollers  159 ,  160 , and a pair of stoppers  165 . 
     The frame  151  extends in right and left directions. The stoppers  165  are positioned at right and left portions of the frame  151 , thereby defining a moving region between the stoppers  165 . The holder  154  is slidably supported by the frame  151 . The pair of the rollers  159 ,  160  are rotatably positioned outside of the moving region. The wire  161  is wound around and extends between the pair of the rollers  159 ,  160 . Also, a portion of the wire  161  is fixed to a rear surface of the holder  154 . With this configuration, when the rollers  159 ,  160  rotate, the holder  154  is reciprocally moved within the moving region. 
     The rotary blade  156  is rotatably supported on the holder  154 . The fixed blade  155  is provided in a lower surface of the through hole  151   a  of the frame  151 , and extends throughout the entire moving region. An edge of the fixed blade  155  contacts a lower portion of the rotary blade  156 . Therefore, when the holder  154  moves along with the rotary blade  156 , the rotary blade  156  rotates because of the friction between the rotary blade  156  and the fixed blade  155 . With this configuration, the recording medium  4  is cut straight when the rotary blade  156  slides in the right and left directions within the moving region. 
     The cleaning members  170  are provided at outsides of and near the ends of the moving region between the fixed blade  155  and an upper surface of the through hole  151   a  of the frame  151 . The reason for positioning the cleaning members  170  outside of the moving region is for allowing the recording medium  4  to pass through the through hole  151   a  without being blocked by the cleaning members  170 . The cleaning member  170  is formed from foam polyurethane having a plurality open cells to have a thickness of about 1 mm, and capable of absorbing and holding liquid, such as water and oil. However, the cleaning member  170  can be formed from other materials, such as felt. When the rotary blade  156  contacts the cleaning member  170 , adhesive materials clinging to the rotary blade  156  can be removed by the cleaning member  170 . 
     Next, a cleaning operation according to the present embodiment will be described. 
     The cutting unit  107  cuts the recording medium  4  provided through the through hole  151   a  of the frame  151  by sliding the rotary blade  156  in the right and left directions. At this time, adhesive materials come out of the recording medium  4  and adhere onto the rotary blade  156 . However, when the rotary blade  156  reaches the end of the moving region, a lower portion of a rear surface of the rotary blade  156  contacts the cleaning member  170 . At this time, the adhesive material on the rotary blade  156  is wiped off by the cleaning member  170 . In this way, the rotary blade  156  can be regularly cleaned. 
     The cleaning member  170  can be provided at only one end of the moving region. However, it is preferable to provide the cleaning members  170  at both ends of the moving region so that the rotary blade  156  can be cleaned more often. 
     As described above, according to the second embodiment of the present invention, the cleaning member  170  cleans the rotary blade  156  by removing adhesive materials. Therefore, the rotary blade  156  can be prevented from being degraded because of the adhesive materials, thereby providing a durable rotary blade  156 . 
     The cleaning members  170  are merely inserted between the frame  151  and the fixed blade  155 . Therefore, the cleaning members  170  can be easily replaced when the rotary blade  156  is not in contact with the cleaning members  170 . 
     It should be noted that the cleaning member  170  can be provided with a function for preventing the adhesive materials from attaching onto the rotary blade  156 . For example, water may be applied to the cleaning member  170 . In this case, upon the rotary blade  156  contacting the cleaning member  170 , the water is supplied onto and forms a water film over the surface of the rotary blade  156 . The water film prevents the adhesive materials from attaching onto the rotary blade  156 . It should be noted that other liquid, such as oil, which is less volatile than water can form a longer lasting film on the rotary blade  156 . 
     When the cleaning member  170  is supplied with such function, the cutting unit  107  can be further provided with a liquid supply unit for supplementing the cleaning member  170  with the liquid. The liquid supply unit can be formed in any configuration. For example, liquid can be supplied from a tank through a tube to the cleaning member  170  at a regular interval, or a member holding the liquid can be merely placed behind the cleaning member  170 . 
     Alternatively, the cleaning member  170  can be provided with a function for applying an agent which dissolves the adhesive materials on the rotary blade  156 . The agent can be, for example, methyl ethyl ketone. With this configuration, the cleaning member  170  can further effectively remove the adhesive materials from the surface of the rotary blade  156 . In this case also, it is preferable to provide an agent supply unit for supplying such agent to the cleaning member  170 . The agent supply unit can be configured in the same manner as the above-described liquid supply unit. 
     Further, the rotary blade  156  can be controlled to reciprocate so as to only be cleaned up without performing any cutting operations. Such a cleaning operation can be performed based on data received from a sensor or from a counter. The sensor can be for detecting the amount of adhesive material accumulated on the rotary blade  156 . The counter can be for counting how may times an image forming operation has been performed or for measuring time elapsed since a previous cleaning operation. 
     Next, a cutting unit  107   a  according to a first modification of the second embodiment of the present invention will be described while referring to FIG.  13 . 
     The cutting unit  107   a  is similar to the cutting unit  107 . However, the cutting unit  107   a  includes a cleaning member  171  formed longer than the cleaning member  170  and protruding over the rear surface of the frame  151 . 
     With this configuration, the cleaning member  171  can be further easily replaced with a new one. Also, in case of providing the liquid supply member described above, the liquid supply member needs not to be configured to supply liquid through the narrow through hole  151   a . This simplifies the configuration of the cutting unit  107   a.    
     Next, a cutting unit  107   b  according to a second modification of the second embodiment will be described while referring to FIG.  13 . 
     The cutting unit  107   b  is similar to the cutting unit  107 . However, the cutting unit  107   b  includes a cleaning member  172  supported by the holder  154  so as to contact the upper portion of the rear surface of the rotary blade  156  all the time. The cleaning member  172  is capable of holding water, and the cutting unit  107   b  is further provided with a water supply member  173  above the cleaning member  172  for periodically supplying water to the cleaning member  172 . The cleaning member  172  can be replaced while the rotary blade  156  is dismounted from the holder  154 . 
     Because the cleaning member  172  is supported by the holder  154 , the cleaning member  172  reciprocally moves along with the holder  154  while contacting the rotary blade  156 . Therefore, the cleaning member  172  can smoothly and quickly remove adhesive materials from the rotary blade  156 . 
     It should be noted that the cleaning member  172  can hold, instead of water, an agent capable of dissolving the adhesive materials. In this case, instead of the water supply unit  173 , an agent supply unit should be provided. 
     It also should be noted that the cleaning member  172  can be omitted so that the water supply member  173  supplies water directly to the rotary blade  156 . In this case, although the rotary blade  156  cannot be cleaned by the cleaning member  173 , water supplied from the water supply member  173  forms a film over the surface of the rotary blade  156 . The water film can prevent adhesive materials from clinging to the rotary blade  156 . Also, instead of the water supply member  173 , the above-described agent supply unit can be provided for supplying the agent directly to the rotary blade  156 . 
     Although, in the above-described second embodiment, the cutting unit  107  includes the rotary blade  156 , the cutting unit  107  can include a slide cutter instead. Examples of the slide cutter will be described while referring to FIGS.  14 ( a ) to  15 ( b ). 
     As shown in FIGS.  14 ( a ) and  14 ( b ), a slide cutter  181  includes a sliding upper blade  182  and a fixed lower blade  183 . The lower blade  183  is provided with a cleaning member  184  formed from a polyurethane felt in a surface with which the upper blade  182  comes into contact. When the upper blade  182  comes into contact with the cleaning member  184 , adhesive material can be wiped off of the upper blade  182 . 
     On the other hand, as shown in FIGS.  15 ( a ) and  15 ( b ), a slide cutter  185  includes a sliding upper blade  186  and a fixed lower blade  187 . The upper blade  186  is formed in a substantial M shape, that is, with the central portion retracted back from the side portions. The lower blade  187  is provided with a cleaning member  189  in the same way as the lower blade  183  of the above-described slide cutter  181 . The lower blade  187  is further formed with a groove  188  for providing an escape portion into which adhesive is collected. 
     It should be noted that the cutting unit  107  can any kind of blade, and is not limited to those described above. 
     Although, in the above-describe second embodiment, the cutting unit  107  is positioned at the upstream side of the support  9  in the feed direction F, the cutting unit  107  can be positioned at the downstream side. 
     Next, a photosensitive/pressure-sensitive printer  201  according to a third embodiment of the present invention will be described while referring to FIGS. 16 to  18 . The photosensitive/pressure-sensitive printer (hereinafter abbreviated simply to “printer”)  201  is similar to the printer  1  of the first embodiment, except that the printer  201  includes a cutting unit  207 . Therefore, only the cutting unit  207  will be described in detail for avoid a duplication of explanation. 
     As shown in FIG. 16, the cutting unit  207  is disposed so as to be capable of cutting the recording medium  4  at a slant with respect to the thickness direction of the recording medium  4 . 
     Specifically, as shown in FIG. 17, the cutting unit  207  includes a disk-shaped rotary blade  256 , a rectangular fixed blade  255 , a holder  254  formed with grooves  256   a , and a frame  251  formed with a through hole  251   a , and a wire  261 . 
     The wire  261  is fixed to a rear surface of the holder  254 , and wound around a pair of rollers (not shown). When the rollers rotate, the holder  254  is reciprocally moved within a moving region defined by a pair of stoppers (not shown). 
     The rotary blade  256  is rotatably supported on the holder  254 . The fixed blade  255  is provided in a lower surface of the through hole  251   a  of the frame  251 , and extends throughout the moving region. An edge of the fixed blade  255  contacts a lower portion of the rotary blade  256 . When the rotary blade  256  moves along with the holder  254 , the rotary blade  256  rotates by friction generated by the rotary blade  256  abutting against the fixed blade  255 . 
     The fixed blade  255  is disposed in a horizontal posture. The surface of the fixed blade  255  that comes in contact with the rotary blade  256  is formed to 30 degree angle with respect to the vertical direction. On the other hand, the rotary blade  256  is supported in a slanting posture with an angle of about 30 degrees with respect to the vertical direction. With this configuration, when the rotary blade  256  is moved leftward and rightward while the recording medium  4  is positioned in the through hole  251   a  of the frame  251 , the recording medium  4  is cut at a 30 degree angle with respect to its thickness direction and perpendicular to the feed direction F. Accordingly, the front and rear edges of the cut recording medium  4  form an angle of about 60 degrees. As a result, the cut recording medium  4  has a thickness that gradually increases from the leading and rear edges toward its center portion. 
     As shown in FIG. 18, the recording medium  4  cut in this manner is inserted in between the pressing rollers  19   a ,  19   b  from its angled leading edge portion  4   b  and is discharged from between the pressing rollers  19   a ,  19   b  from its angled rear edge  4   c . Accordingly, when the recording medium  4  is inserted in between the pressing rollers  19   a ,  19   b , the recording medium  4  gradually pushes open the pressing rollers  19   a ,  19   b  while entering between the pressing rollers  19   a ,  19   b . As a result, the pressing rollers  19   a ,  19   b  are not rapidly pressed wide open by the movement of the recording medium  4 . Therefore, no large shock is applied to the pressing rollers  19   a ,  19   b . It should be noted that the distance between the pair of pressing rollers  19   a ,  19   b  is set to about half the thickness of the recording medium  4 . 
     The same is true when the recording medium  4  is discharged from between the pressing rollers  19   a ,  19   b . That is, when the rear edge portion  4   c  of the recording medium  4  is discharged from between the pressing rollers  19   a ,  19   b , the thickness of the rear edge portion  4   c  gradually decreases in the direction opposite the feed direction F. Therefore, the pressing rollers  19   a ,  19   b  gradually come closer to each other. Accordingly, the recording medium  4  is not rapidly discharged from between the pressing rollers  19   a ,  19   b , so that no large shock is applied to the pressing rollers  19   a ,  19   b.    
     The surface area of the recording medium  4  being pressed by the pressing rollers  19   a ,  19   b  is the same at the front and rear edges portion  4   b ,  4   c  as at all other portions of the recording medium  4 . Therefore, the surface area of the recording medium  4  between the pressing rollers  19   a ,  19   b  does not change as the recording medium  4  is transported. Accordingly, the pressure applied per unit of surface area on the recording medium  4  only fluctuates slightly with transport of the recording medium  4 . For this reason, the amount that the microcapsules  32  are ruptured is stable. Therefore, an image can be developed in the recording medium  4  without unevenness even at the front and rear edge portions  4   b ,  4   c.    
     Because the thickness at the front and rear edge portions  4   b ,  4   c  of the recording medium  4  is small, only a relatively small compression energy is accumulated at the front and rear edge portions  4   b ,  4   c . Accordingly, the recording medium  4  will not fly out from between the pressing rollers  19   a ,  19   b . Therefore, the recording medium  4  can always be properly developed by application of sufficient pressure. 
     It should be noted that according to the present embodiment, the front and rear edge portions  4   b ,  4   c  are cut to form an angle of 60 degrees. However, the angle formed between the rotary blade  256  and the fixed blade  255  of the cutting unit  207  can be changed in order to optionally change angle formed by the front and rear edge portions  4   b ,  4   c.    
     The angle formed at the front and rear edge portions  4   b ,  4   c  is desirably between 30 and 60 degrees for practical reason. When the angle is too large, a shock will not be sufficiently decreased. On the other hand, when the angle is too small, the front and rear edge portions  4   b ,  4   c  will be too thin at the end-most portion, so that image forming may not performed properly. 
     The above-described cutting unit  207  includes the rotary blade  256  so that the cutting unit  207  can easily and accurately cut the recording medium  4 . However, any other type of cutting unit can be used. FIGS.  19 ( a ) to  22 ( b ) show examples of cutting unit that can be used in the printer  201 . 
     As shown in FIGS.  19 ( a ) and  19 ( b ), a slide cutter  281  includes an upper movable blade  281   a  and a lower fixed blade  281   b . Felt  281   c  is fitted in an upper surface of the fixed blade  281   b . The felt  281   c  is formed from polyurethane for wiping off adhesive materials clinging to the movable blade  281   a . Both the movable blade  281   a  and the fixed blade  281   b  are disposed at an angle of about 30 degrees with respect to the vertical direction. Therefore, the recording medium  4  is cut at an angle of 60 degrees at its front and rear edges. 
     As shown in FIGS.  20 ( a ) and  20 ( b ), a slide cutter  282  includes an upper movable blade  282   a  and a lower fixed blade  282   b . The movable blade  282   a  is formed in a substantial M shape, that is, with the central portion retracted back from the side portions. The fixed blade  282   b  is formed with a groove  282   c  in its abutment surface that comes in abutment with the movable blade  282   a . A felt member  282   d  formed from polyurethane is fitted in the groove  282   c . The groove  282   c  serves as a drain for removing adhesive materials collected from the movable blade  282   a  and the fixed blade  282   b.    
     The movable blade  282   a  and the fixed blade  282   b  are disposed at a 30 degree angle with respect to the vertical direction. Therefore, the slide cutter  282  will cut the recording medium  4  at an angle of 60 degrees at front and rear edges. 
     As shown in FIGS.  21 ( a ) and  21 ( b ), a slide cutter  283  includes an upper movable blade  283   a  and a lower fixed blade  283   b . The fixed blade  283   b  has an abutment surface that is processed to form knurling for preventing the recording medium  4  from clinging to the fixed blade  283   b  by static electricity. In this example also, the movable blade  283   a  and the fixed blade  283   b  are disposed at a 30 degree angle with respect to the vertical direction. Therefore, the slide cutter  283  can cut the recording medium  4  at an angle of 60 degrees at front and rear edges. 
     As shown in FIGS.  22 ( a ) and  22 ( b ), a slide cutter  284  includes an upper movable blade  284   a  and a lower fixed blade  284   b . The movable blade  284   a  is formed in a substantial M shape. The fixed blade  284   b  is formed with a plurality of through holes  284   c  for preventing the recording medium  4  from clinging to the fixed blade  284   c  by static electricity. In this example also, the movable blade  284   a  and the fixed blade  284   b  are disposed to form a 30 degree angle with respect to the vertical direction. Therefore, the slide cutter  284  can cut the recording medium  4  at a 60 degree angle at its front and rear edges. 
     Next, a photosensitive/pressure-sensitive printer  301  according to a fourth embodiment of the present invention will be described while referring to FIGS. 23 to  29 ( f ). 
     As shown in FIG. 23, the photosensitive/pressure-sensitive printer (hereinafter abbreviated simply to printer”)  301  is similar to the above-described printer  1  of first embodiment shown in FIG. 2, and includes the cassette  3 , the pressing glass  8 , the transfer belt  6 , the support  9 , the developing unit  19 , the fixing unit  20 , the discharge tray  22 , and the exposure unit  10 . However, the printer  301  further includes a first feed unit  390 , a second feed unit  391 , a third feed unit  392 , a first sensor  393 , and a second sensor  394 . The first feed unit  390  and the first sensor  393  are provided between the cassette  3  and the support  9 . The second feed unit  391 , the second sensor  394 , the cutting unit  307 , and the third feed unit  392  are provided in this order between the support  9  and the developing unit  19  in the feed direction F. 
     The first, second, and third feed units  390 ,  391 ,  393  include driving rollers  390   a ,  391   a ,  392   a  and driven rollers  390   b ,  391   b ,  392   b , respectively. Each of the driving rollers  390   a ,  391   a ,  392   a  is connected to a reversible pulse motor  323  shown in FIG. 24 via a gear mechanism (not shown), and driven to rotate. The driven rollers  390   b ,  391   b ,  392   b  are pressing to the corresponding driving rollers  390   a ,  391   a ,  392   a . With this configuration, the feed units  390 ,  391 ,  392  feed the recording medium  4  both in a normal direction, that is, the feed direction F, and a reversing direction opposite from the feed direction F. 
     The first sensor  393  detects the leading edge of the recording medium  4 , and outputs a detection signal indicating the positional relationship between the recording medium  4  and a predetermined exposing position. 
     The cutting unit  307  is provided at a predetermined cutting position. The cutting unit  307  includes an upper cutting blade  307   a  and a lower cutting blade  307   b  for cutting the recording medium  4  placed between the upper and lower cutting blades  307   a ,  307   b . The second sensor  394  detects the leading edge of the recording medium  4 , and outputs a detection signal indicating a positional relationship between the recording medium  4  and the cutting position. 
     It should be noted that in the present embodiment, as shown in FIG. 25, the focus lens  15  is set so that an optical image passing through the focus lens  15  forms the optical image having an exposure region S 1  on an recording medium  4 . The exposure region S 1  should be larger than an output size S 2  of the recording medium  4 . That is, the exposure region S 1  is set to have an exposure length E greater than an output length A and an exposure width F greater than an output width B. 
     As shown in FIG. 24, the printer  301  further includes a central processing unit (CPU)  324  for controlling various processes. The CPU  324  includes an input/output portion, a data communication portion, a calculation portion, a memory portion, and the like. The input/output portion is connected to the first sensor  393 , the second sensor  394 , the reversible pulse motor  323 , the exposure unit  10 , and the cutting unit  307 . The data communication portion is connected to an external information processing device  25 . The memory portion includes a recording region for storing a print control routine, control data, print data, such as image data and character data, and control calculation data. The calculation portion executes the print control routine for cutting the recording medium  4  into the output size S 2  in a manner to be described later and forming an image on the recording medium  4 . 
     Next, an image forming operation of the printer  301  according to the fourth embodiment will be described. 
     The image forming operation is started when the CPU  324  receives an image forming command from the information processing device  25 . When the image forming operation is started, the CPU  324  confirms whether or not the first sensor  393  has detected the leading edge of the recording medium  4 . If not, then the CPU  324  controls the pulse motor  323  to rotate the driving roller  390   a  in the normal direction to draw the recording medium  4  from the cassette  3 . Then, the recording medium  4  is transported downstream toward the through hole. 
     Images can be outputted in the two different forms, with a white frame or without a white frame. The first type is referred to as an image with a white frame, and a second type is referred to as a total image. First, the situation for forming an image with a white frame will be explained while referring to a series of operations shown in FIGS.  27 ( a ) to  27 ( e ). 
     After the first sensor  393  detects the leading edge of the recording medium  4 , the CPU  324  drives the pulse motor  323  by a predetermined number of pulses. As a result, the leading edge of the recording medium  4  is aligned at a predetermined exposure side line S 2   a . Next, the transfer belt  6  shown in FIG. 23 is moved toward the pressing glass  8  so that the recording medium  4  is pressed flat. 
     Next, print data inputted from the information processing device  25  is outputted on the liquid crystal panel  13  to form an exposure image. Afterwards, the light source  11  is turned ON to radiate white light. The white light is condensed by the condenser lens  12 , and then formed by the liquid crystal panel  13  into an optical image corresponding to the exposure image. The optical image is then formed into an optical image of an optical component, such as, a blue light component, by the color filter of the filter member  14 . After the optical image is condensed to a predetermined focal point distance by the focus lens  15 , the optical image is irradiated onto the recording medium  4  through the pressing glass  8 . As a result, the recording medium  4  is exposed in the exposure region S 1 . The microcapsules  32  are selectively hardened by reacting to the blue light component, and a latent image corresponding to the optical image is formed in the recording medium  4 . 
     Afterwards, the filter member  14  is rotated and the color filter is changed in order to perform exposure for other optical components. As a result, latent images for each optical component are formed in order in the recording medium  4 . 
     It should be noted that, as shown in FIG. 25, when a white frame  27  is to be formed around an image  26 , the information process device  25  beforehand performs image data processes for overlapping white frame data for forming a white latent image around an image range S 3 . The image range S 3  has an image length C and an image width D. All microcapsules  32  in the latent image are hardened to form the white frame  27 . 
     Then, the transfer belt  6  is separated from the pressing glass  8  to release pressure against the recording medium  4 , and the recording medium  4  is transported in the feed direction F. When the second sensor  394  detects the leading edge of the recording medium  4 , the pulse motor  323  is driven by a predetermined number of pulses to align a cutting portion A 1  of the recording medium  4 , that is, a rear side line of the output region S 2 , with the cutting position as shown in FIG.  27 ( b ). 
     Next, as shown in FIG. 26, the cutting unit  307  is operated to cut the recording medium  4  at the cutting portion A 1  to cut the recording medium  4  down to the predetermined output size S 2 . At this time, mechanical stress generated by the cutting operation is applied to the microcapsules  32  in the cutting portion A 1 . However, all of the microcapsules  32  in the cutting portion A 1  had been hardened for producing the white frame  27 . Therefore, non of the microcapsules  32  in the cutting portion A 1  will be crushed. As a result, the cutting portion A 1  will be maintained in the same color as the white frame  7  when the recording medium  4  is cut. 
     Next, as shown in FIG.  27 ( c ), the third feed unit  392  transports the cut recording medium  4  to the developing unit  19 , where an image corresponding to the latent image is developed in the recording medium  4  by rupturing unhardened microcapsules  32 . Afterwards, the fixing unit  20  thermally fixes the developed image onto the recording medium  4 . The recording medium  4  is, then, discharged through the discharge port  2   a  onto the discharge tray  22 . 
     While the developing and fixing operations are being performed as described above, the third feed unit  392  is rotated to transport the recording medium in the reversing direction. When the second sensor  394  detects the leading edge of the recording medium  4 , the pulse motor  323  is driven by the predetermined number of pulses so that, as shown in FIG.  27 ( d ), the recording medium  4  is returned to the position where the leading edge of the recording medium  4  is aligned with the exposure side line S 2   a . Afterwards, as shown in FIG.  27 ( e ), the image forming operation is performed for subsequent print data. 
     It should be noted that when the leading edge of the recording medium  4  is aligned to the exposure side line S 2   a  as shown in FIG.  27 ( e ), an edge portion G of the exposure region S 1  by the previous image forming exposure overlaps the exposure region S 1  for the next image exposure. However, the white frame  27  is formed on the overlapping portion, that is, the edge portion G, in the next image exposure. Therefore, image quality will not suffer. Also, because the edge portion G will not be wasted, consumption of the recording medium  4  can be reduced. 
     Next, an explanation will be provided for the total image without a white frame. In this case, the series of operations shown from FIG.  28 ( a ) to  29 ( f ) are performed. 
     When the first sensor  393  detects the leading edge of the recording medium  4 , the CPU  324  controls the pulse motor  323  to drive the predetermined number of pulses. As a result, as shown in FIG.  28 ( a ), the recording medium  4  is positioned so that the leading edge is positioned outside of the exposure region S 1 . Then, image exposure is performed for exposing the recording medium  4  with an image having the exposure region S 1 . As a result, a latent image is formed in the recording medium  4 . 
     Afterwards, as shown in FIG.  28 ( b ), the recording medium  4  is transported so that a cutting portion A 2  is aligned with the cutting position. Then, as shown in FIG.  28 ( c ), a waste portion  4   a  of the recording medium  4   a  is cut away. Afterwards, as shown in FIG.  28 ( d ), the recording medium  4  is transported so that its cutting portion A 1  aligns with the cutting position. The recording medium  4  is cut at the cutting portion A 1  down into the output size S 2  as shown in FIG.  27 ( e ). 
     At this time, unhardened microcapsules  32  in the range of mechanical stress are ruptured. However, the crushed microcapsules  32  are those that are not hardened as a result of the image exposure. Therefore, the ranges of the cutting portions A 1 , A 2  will be developed in harmony with color shades of adjacent regions. 
     Next, as shown in FIG.  28 ( e ), the cut recording medium  4  is transported to the developing unit  19 . An image corresponding to a latent image is developed at the developing unit  19 , and thermally fixed in the fixing unit  20 . Then, the cut recording medium  4  is discharged through the discharge port  2   a  onto the discharge tray  22 . 
     While the developing and fixing processes are being performed as described above, the third feed unit  392  transports the recording medium  4  in the reversing direction. When the second sensor  394  detects the leading edge of the recording medium  4 , the pulse motor  323  is driven the predetermined number of pulses. As a result, the recording medium  4  is returned to the through hole where the leading edge is positioned outside of the exposure region S 1  as shown in FIG.  29 ( a ). Afterwards, image exposure is performed as shown in FIGS.  29 ( b ) to  29 ( f ) in the same manner as described in FIGS.  28 ( a ) to  28 ( e ) when a subsequent print data is inputted. 
     The image forming operations for forming images with frames and images without frames were explained separately. However, by performing operations for images without frames, it is possible to output images with frames and images without frames mixed together. 
     The cutting unit  307  described above includes the upper and lower cutting blades  307   a ,  307   b . However, the cutting unit  307  can include a rotating type cutter blade. 
     According to the above-described fourth embodiment, when an image without a frame is formed in the recording medium  4 , the image portion is cut during the cutting operation. However, because the color will be in a harmony with adjacent regions, image quality will not suffer. Also, because an additional exposure unit for exposing cutting portions of the recording medium  4  is unnecessary, the printer  301  can be produced in a small size and with reduced cost. Also, the exposure operation is performed only once, the overall operation takes less time. 
     Also, in the printer  301 , the cutting unit  307  is positioned downstream side of the exposure unit  10  in the feed direction F. Because the exposure unit  10  and the cutting unit  307  are arranged to perform the series of operations in this order, all processes are completed by transporting the recording medium  4  in a single direction, that is in the feed direction F. Accordingly process time can be reduced compared to if the recording medium  4  had to be transported backward to the cutting unit  307  after image exposure was performed by the exposure unit  10 . It should be noted that the cutting unit  307  can be disposed upstream from the exposure unit  10 . 
     According to the above-described fourth embodiment, as shown in FIG. 25, the exposure region S 1  is set to be broader than the output size S 2 . Therefore, a desired color condition can be made in the vicinity of the cutting portions of the recording medium  4  cut down into the output size S 2 . 
     While the invention has been described in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the attached claims. 
     For example, in the above described embodiments, photosensitive/pressure-sensitive printers are used as examples of a photosensitive/pressure-sensitive image forming device. However, other types of photosensitive/pressure-sensitive image forming device, such as a facsimile device and a copying machine, can be used instead. 
     The recording medium  4  of the embodiment is formed from a single sheet containing both coreactant and microcapsules  32  wherein the microcapsules  32  contain a dye precursor and which are ruptured by a pressure. However, this is not a limitation of the present invention. For example, the recording medium  4  can include microcapsule that has a strength reduced by exposure. Further, other well known photosensitive/pressure-sensitive recording media can be used. 
     Also, instead of the roll of the recording medium  4 , microcapsule sheets in a stacked condition can be used as long as they have an elongated length.