JP2007140232A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high-quality image while achieving the miniaturization of an image forming apparatus A, which forms an image on the emulsion surface of paper P while conveying the paper P. <P>SOLUTION: The image forming apparatus is constituted so that the conveying unit 6 of an upstream side conveying part 17 conveys the paper P nearly in a horizontal direction at a height position equal to or under the center in the up-and-down direction of a supply part 1. An upstream side loop part Pa loosened upward is formed at the part of the paper P between the supply part 1 and an exposure engine 7 (image forming part), and a loop part housing space W for housing the upstream side loop part Pa is provided above the upstream side conveying part 17. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to a technical field related to an image forming apparatus that forms an image on an image forming surface of an image forming medium while conveying the image forming medium.

2. Description of the Related Art Conventionally, as an image forming apparatus used for photographic development or the like, image exposure is performed on a paper made of a photosensitive material (for example, an image forming medium such as photographic paper) with a laser beam as disclosed in, for example, Patent Document 1. The device is known. This device reads image data of frame images formed on developed negative film and image data stored in various storage media, and based on these image data, it is used on the emulsion surface (image forming surface) of paper. The image is configured to be printed and exposed. That is, this apparatus includes a supply unit for supplying paper (usually provided with a magazine loading unit in which a container (magazine) for storing paper is loaded), and upstream conveyance for conveying the paper supplied from this supply unit. An image forming unit that forms an image on the emulsion surface of the paper conveyed from the upstream conveying unit, and paper that is disposed downstream of the image forming unit and is fed from the image forming unit. And a downstream side transport unit for transporting. The image forming unit is provided with a transport unit and a laser unit for transporting paper at a constant speed. In this laser unit, for example, as shown in Patent Document 2, a laser that emits laser light is provided. A light source, a polygon mirror for scanning the laser beam with respect to the emulsion surface of the paper in the paper width direction, and the like are provided. Then, the laser beam is irradiated onto the emulsion surface of the paper conveyed by the conveyance mechanism while scanning in a direction (paper width direction) perpendicular to the conveyance direction. An image is formed. The paper on which the latent image is formed is transported to the development processing section and subjected to development processing, whereby a desired image such as a photographic image is formed on the emulsion surface of the paper.
Japanese Patent No. 3597342 JP-A-5-134199

  By the way, in order to obtain a high-quality image without unevenness in the image forming apparatus as described above, it is necessary to carry the paper with high accuracy during the image formation by the laser beam. It is necessary to prevent the load fluctuation from being transmitted to the image forming portion (exposed portion) of the paper during image formation in the forming portion. In particular, when a cutting device that cuts the paper into a predetermined length is provided between the supply unit and the upstream conveyance unit, load fluctuation is transmitted to the image forming portion when the cutting device is operated, and the image quality is improved. Adversely affect. Therefore, in Patent Document 1, a buffer for preventing load fluctuation from being transmitted to the image forming portion of the paper is secured on the upstream side and downstream side of the image forming position by the paper transport path. Has been proposed.

  However, in the method of securing the buffer by the paper conveyance path, the longer the length of the paper to be processed, the longer the conveyance path. As a result, the apparatus can be downsized and the cost can be reduced. Becomes difficult.

  The present invention has been made in view of such points, and an object of the present invention is to obtain a high-quality image while reducing the size of the image forming apparatus as described above. There is.

  In order to achieve the above object, according to the present invention, the transport mechanism of the upstream transport unit is configured to transport the image forming medium in a substantially horizontal direction at a height position below the center in the vertical direction of the supply unit. A loop portion for forming an upstream loop portion slacking upward in a portion between the supply portion and the image forming portion in the image forming medium and accommodating the upstream loop portion on the upper side of the upstream transport portion An accommodation space was provided.

  Specifically, according to the first aspect of the present invention, as the image forming apparatus, a supply unit that supplies an image forming medium and an image forming medium that is supplied from the supply unit have a height equal to or lower than the center in the vertical direction of the supply unit. While conveying the image forming medium conveyed by the conveying mechanism of the upstream conveying unit including the conveying mechanism that conveys in a substantially horizontal direction at the position and the conveying mechanism of the upstream conveying unit in the extension direction of the conveying direction by the conveying mechanism, An image forming unit that forms an image on the image forming surface of the image forming medium, and an image forming unit that is disposed so as to extend in the vertical direction on the conveyance downstream side of the image forming unit and is sent out from the image forming unit A cutting device for cutting the image forming medium into a predetermined length is provided between the supply unit and the upstream conveying unit, and the image forming medium includes: a downstream conveying unit configured to convey a medium; Without being cut by the cutting device When an image is formed on the image forming surface of the image forming medium while being connected between the supplying unit and the image forming unit, a portion between the supplying unit and the image forming unit in the image forming medium In addition, an upstream loop portion that sags upward is formed, and a loop portion accommodation space for accommodating the upstream loop portion is provided above the upstream transport portion. .

  With the above configuration, the upstream loop portion is formed in the portion of the image forming medium between the supply portion and the image forming portion. Therefore, when the image forming medium is cut by the cutting device, image formation from the supply portion is performed. Even if the supply of the medium is stopped, the load fluctuation due to the stop is not transmitted to the image forming portion of the image forming medium during image formation in the image forming unit, and the load fluctuation due to the cutting itself is not transmitted. Absent. By forming the upstream loop portion, the distance between the supply portion and the image forming portion can be shortened. In addition, since the downstream transport unit extends in the vertical direction, the length in the left-right direction of the apparatus can be shortened in combination with shortening the distance between the supply unit and the image forming unit. it can. In addition, since the transport mechanism of the upstream transport unit transports the image forming medium in a substantially horizontal direction at a height position equal to or lower than the center in the vertical direction of the supply unit, the upper side of the upstream transport unit is above the supply unit. There will be a corresponding space, and the loop portion accommodation space can be easily formed in the space. Further, if the upper end position of the downstream side transport unit is made substantially the same as the upper end position of the supply unit or the loop unit accommodation space, the apparatus can be downsized in the vertical direction. Therefore, high-quality images can be obtained while reducing the size of the apparatus.

  According to a second aspect of the invention, in the first aspect of the invention, the supply unit includes a plurality of loading units into which containers accommodated in a state where the image forming medium is wound in a roll shape are loaded. The image forming medium is selectively supplied from any one of the containers respectively loaded in the plurality of loading units, and the plurality of loading units are arranged in the vertical direction in the supply unit. It shall be installed.

  As a result, a plurality of types of image forming media having different widths and the like can be set in the apparatus in advance, thereby eliminating the trouble of replacing the image forming media one by one and improving workability. On the other hand, the volume of the supply unit increases corresponding to the number of loading units. However, since the plurality of loading units are arranged in the vertical direction, the supply unit becomes vertically long, and the length of the apparatus in the horizontal direction. Will not be long. Thus, if the supply unit is vertically long, the space of the loop portion accommodation space can be increased in the vertical direction, thereby reliably preventing load fluctuations from being transmitted to the image forming portion of the image forming medium. Will be able to. Further, if the downstream side conveyance unit is also enlarged in the vertical direction corresponding to the supply unit, the downstream side conveyance unit also has a buffer for preventing the load fluctuation from being transmitted to the image forming part of the image forming medium. It becomes easy to form. Furthermore, from the viewpoint of reducing the vertical space, a light source unit having a light source that emits light for forming an image on the image forming surface of the image forming medium is disposed above the loop housing space. In this arrangement, the image forming medium is conveyed with the image forming surface facing upward in the upstream conveying unit. The outer surface of the upstream loop portion formed on the image forming medium is an image forming surface, and the outer surface of the roll accommodated in the container is also usually an image forming surface. The upstream loop portion can be easily formed by the winding kite.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the downstream-side transport unit includes a turn unit that turns the image forming medium fed from the image forming unit upward.

  That is, when the length of the image forming medium after being cut by the cutting device is longer than the conveyance length between the image forming unit and the next processing unit such as the developing process, the image forming medium is being formed on the image forming medium. The leading edge of the image forming medium enters the next processing unit, and vibrations and load fluctuations generated by the processing in the next processing unit are transmitted to the image forming portion of the image forming medium. However, in the present invention, since the downstream transport unit is provided with a turn mechanism that turns the image forming medium fed from the image forming unit upward, vibrations and load fluctuations in the next processing unit are turned by the turn mechanism. It is absorbed by the turn portion of the formed image forming medium and is difficult to be transmitted to the image forming portion. Therefore, it is not necessary to provide a large space or a long conveyance path as a buffer on the downstream side of the image forming unit, and the space of the downstream conveyance unit can be reduced.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, a downstream loop portion is formed in the turn portion of the image forming medium turned by the turning means.

  By doing so, it is possible to more reliably prevent vibrations and load fluctuations generated by processing in the next processing unit from being transmitted to the image forming portion of the image forming medium. Further, since the vibration and load fluctuation can be prevented simply by providing a turn portion on the image forming medium, a relatively small downstream loop portion may be formed, thereby reducing the space of the downstream conveyance portion. Can be maintained.

  As described above, according to the image forming apparatus of the present invention, the transport mechanism of the upstream transport unit is configured to transport the image forming medium in a substantially horizontal direction at a height position below the center in the vertical direction of the supply unit. In addition, an upstream loop portion that is slacked upward is formed in a portion between the supply portion and the image forming portion in the image forming medium, and the upstream loop portion is accommodated on the upper side of the upstream transport portion. By providing the space for accommodating the loop portion, the apparatus can be reduced in size in the left and right and up and down directions, and the size can be reduced, and the load on the image forming portion of the image forming medium during image formation in the image forming portion A high-quality image can be obtained without the fluctuation being transmitted.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

  FIG. 1 is a partial cross-sectional view illustrating a configuration of a photographic processing system including an image forming apparatus A according to an embodiment of the present invention. The photographic processing system shown in FIG. 1 acquires image data, and based on this image data, an emulsion surface (corresponding to an image forming surface) of a paper P (corresponding to an image forming medium) such as photographic paper made of a photosensitive material. It has a function to print images and print them to create photo prints. This photographic processing system scans frame images formed on developed photographic film and uses it for film scanners (not shown) for acquiring image data, storage media for digital cameras, and other recording media. A media reading unit (not shown) for reading stored image data is provided.

  In FIG. 1, a supply unit 1 that supplies paper P is disposed at one end portion (right end portion in FIG. 1) in the left-right direction of the image forming apparatus A. The supply unit 1 includes two magazine loading units 1a and 1a in which paper magazines 3 and 3 as containers are loaded, respectively. The two magazine loading units 1a and 1a are arranged in the vertical direction in the supply unit 1. It is arranged. Thereby, the supply part 1 is formed in the vertically long shape. Each of the paper magazines 3 and 3 contains a long paper P as a roll R wound in a roll shape with the emulsion surface facing outward. The paper magazines 3 and 3 containing the roll R are respectively Removably loaded in the magazine loading portions 1a and 1a, respectively. One of the two paper magazines 3, 3 loaded in the magazine loading section 1a, 1a is selected according to the print size or the like, and the paper P from the selected paper magazine 3 is selected. The paper P is transported along a predetermined transport path in an upstream transport unit 17 and the like described later. That is, the paper P drawn from one of the paper magazines 3 and 3 is changed in direction by the advance roller unit 4 and the like, and is sent out from the supply unit 1 in a substantially horizontal state with the emulsion surface facing upward.

  The paper P sent out from the supply unit 1 is exposed to an exposure engine 7 (corresponding to an image forming unit) located on the downstream side by a transport unit 6 (corresponding to a transport mechanism of the upstream transport unit) provided in the upstream transport unit 17. ). The transport unit 6 is configured to reciprocate substantially horizontally in the horizontal direction at a height position below the center in the vertical direction of the supply unit 1 (in this embodiment, a lower position than the lower magazine loading unit 1a). At the upstream end (the right end in FIG. 1) of the upstream transport unit 17, the leading end of the paper P sent out from the supply unit 1 is sandwiched and received by the pair of rollers 6a and 6a. By moving the paper P to the downstream side (left side in FIG. 1) with the tip of the paper P sandwiched between the pair of rollers 6 a, 6 a, the paper P is moved at a height position below the center in the vertical direction of the supply unit 1. Transport in a substantially horizontal direction. When the transport unit 6 reaches the downstream end of the upstream transport unit 17, an upstream loop portion Pa (see FIG. 5) is formed in a portion between the paper P supply unit 1 and the exposure engine 7 as described later. Thereafter, the rollers 6 a and 6 a are operated to feed the paper P to the exposure engine 7.

  The exposure engine 7 is provided with an upstream exposure conveyance roller 9a and a downstream exposure conveyance roller 9b (also simply referred to as an exposure conveyance roller 9 when they are not distinguished from each other). These upstream side and downstream side exposure transport rollers 9a and 9b transport the paper P transported by the transport unit 6 as it is in the extension direction of the transport direction by the transport unit 6 (the direction of arrow D in FIG. 1). As a result, the paper P is also transported in the exposure engine 7 in a substantially horizontal direction with the emulsion surface facing upward as in the upstream transport section 17.

  Between the upstream and downstream exposure transport rollers 9a and 9b, an exposure position for exposing the paper P transported in the substantially horizontal direction by the both exposure transport rollers 9a and 9b with a laser beam is set. Yes. A paper detection sensor 10 is provided on the upstream side of the upstream exposure / conveying roller 9a, and when the paper P is fed in, the front end (front end) portion is detected and a signal is output. . The paper detection sensor 10 includes a light emitting element that outputs infrared light and a light receiving element that receives the light. By detecting the position of the paper P by the paper detection sensor 10, the exposure start timing at the exposure position can be determined.

  In the exposure engine 7, three laser light sources 72R, 72G, and 72B (see FIG. 4) that emit laser beams for forming a latent image on the emulsion surface of the paper P are positioned above the exposure transport roller 9 respectively. ) Having a substantially rectangular box shape (corresponding to a light source unit). The laser unit 71 extends in a substantially horizontal direction so as to cover the upper side of the upstream transport unit. Then, as will be described in detail later, the laser unit 71 optically modulates the laser beams output from the laser light sources 72R, 72G, and 72B based on the image data, and the light-modulated laser beams are converted into paper. Image exposure is performed by irradiating the emulsion surface of P. When performing image exposure in this way, the paper P is transported at a predetermined speed (constant speed) while being sandwiched between the upstream and downstream exposure transport rollers 9a and 9b. Since the laser beam is scanned in the main scanning direction (paper width direction: arrow B direction in FIG. 4) perpendicular to the paper P transport direction (sub-scanning direction: arrow D direction in FIG. 1), the emulsion of the paper P An image (latent image) is printed on the surface for each line.

  A paper cutter 5 serving as a cutting device for cutting the paper P into a predetermined length corresponding to a preset print size is disposed between the supply unit 1 and the upstream transport unit 17. The length of the paper P after being cut by the paper cutter 5 is usually much longer than the linear distance between the exposure position and the paper cutter 5. For this reason, after performing image exposure to some extent, the paper cutter 5 is operated and the paper P is cut. At the time of cutting, the supply of the paper P from the supply unit 1 is stopped. Due to this stop, it is necessary to prevent the load fluctuation from being transmitted to the exposure position which is the image forming portion of the paper P during image formation in the exposure engine 7. As a countermeasure, in this embodiment, when the transport unit 6 reaches the downstream end of the upstream transport section, an upstream loop section Pa (see FIG. 5) is provided in a portion between the paper P supply section 1 and the exposure engine 7. After that, the rollers 6a and 6a are operated to feed the paper P to the exposure engine 7. As a result, as shown in FIG. 5, an image is formed on the emulsion surface of the paper P with the paper P being connected between the supply unit 1 and the exposure engine 7 without being cut by the paper cutter 5. In this state, an upstream loop portion Pa that is loosened upward is formed in a portion of the paper P between the supply unit 1 and the exposure engine 7. Even when the supply of the paper P from the supply unit 1 is stopped when the paper P is transported by the exposure transport roller 9 to form a latent image, the upstream loop portion Pa is formed. The load fluctuation due to the stop is not transmitted to the exposure position of the paper P, and the load fluctuation due to the cutting itself is not transmitted. The upstream loop portion Pa can be easily obtained by continuing the supply of the paper P from the supply unit 1 while the transport unit 6 is stopped when the transport unit 6 reaches the downstream end of the upstream transport path. Can be formed.

  In the present embodiment, a loop portion accommodation space W for accommodating the upstream side loop portion Pa is provided above the upstream side conveyance portion 17. Such a loop part accommodation space W can be easily formed on the side of the upper part of the supply part 1 because the upstream transport part 17 is at a height position below the center of the supply part 1 in the vertical direction.

  While the image exposure as described above is performed, the paper P is sent out to the downstream side (left side in FIG. 1) from the exposure position by the downstream exposure transport roller 9b. A downstream transport unit 18 that transports the paper P sent out from the exposure engine 7 to the development processing unit is disposed on the transport downstream side of the exposure engine 7. The downstream side conveyance unit 18 is arranged vertically so as to extend in the vertical direction at an end portion (left end portion in FIG. 1) opposite to the supply unit 1 of the image forming apparatus A. The upper end position of the downstream transport unit 18 is substantially at the same height as the upper end positions of the supply unit 1 and the exposure engine 7 (laser unit 71).

  As shown in an enlarged view in FIG. 2, a guide member 16 serving as a turning means for turning the paper P fed from the exposure engine 7 upward is disposed in the vicinity of the exposure position in the downstream transport unit 18. Has been. The guide member 16 is formed in a circular arc shape so as to smoothly guide the front end of the paper P upward, and is composed of a pair of guide plates 16a and 16b that face each other in proximity to both sides in the thickness direction of the paper P. .

  The paper P turned by the guide member 16 is fed into the transport unit 12. The transport unit 12 includes a plurality of sandwiched transport roller pairs 12a arranged along the transport path, and a guide plate 12b for forming the transport path. The transport roller pair 12a is a roller drive described later. It is configured to be driven by means 36 (see FIG. 3). By this transport unit 12, the paper P is transported to the development processing section.

  Of the pair of guide plates 16a and 16b, the guide plate 16a located on the outer peripheral side is configured to be rotatable around a rotation axis at one end thereof, and the other end as shown by a solid line in FIG. It is possible to switch between a guide position that guides the paper P fed out from the exposure engine 7 and a non-guide position indicated by a two-dot chain line. In this embodiment, a guide plate drive mechanism 19 is provided for switching the guide plate 16a by a motor 19a through a belt 19b.

  Then, after the leading end of the paper P is sent to the transport unit 12 via the guide plate 16 at the guide position, the leading end of the paper P is sent to the development processing unit (for example, the leading end of the paper P is developed). And the guide plate 16a is switched to the non-guide position as the rotation of the transport roller pair 12a of the transport unit 12 is stopped. Then, as shown by a two-dot chain line in FIG. 2, the downstream loop portion Pb is formed in the turn portion of the paper P sent out by the downstream exposure transport roller 9b of the exposure engine 7 thereafter. After the downstream loop portion Pb having a predetermined size (a size in which vibration and load fluctuations in the development processing portion are not transmitted to the exposure position) is formed, the transport roller pair 12a is driven to rotate again, and the paper P is developed. It is sent to the processing unit.

  Here, the control block configuration of the image forming apparatus A will be described with reference to FIG. In FIG. 3, the paper leading edge detection means 30 detects the leading edge (front edge) of the paper P by the output signal from the paper detection sensor 10 and detects that the paper P has arrived. Further, it is also possible to recognize at which position the paper P is present on the downstream side based on the timing at which the leading edge of the paper P is detected. The roller driving unit 31 is configured by a driving mechanism, a driving circuit, and the like for driving the exposure conveyance roller 9. Further, the transport amount detection unit 32 is configured to detect the transport amount of the paper P by detecting the rotation amount of the exposure transport roller 9. That is, since the exposure transport roller 9 is controlled to rotate at a constant speed, the transport amount can be monitored by an encoder or the like.

  The paper position detection unit 33 is configured to detect various positions of the paper P based on the front end position of the paper P detected by the paper front end detection unit 30 and the transport amount of the paper P detected by the transport amount detection unit 32. It has the function which calculates | requires and calculates | requires. Specifically, the paper position detection unit 33 includes an exposure start timing detection unit 33a and a paper rear end escape detection unit 33b.

  The exposure start timing detection means 33a is configured to detect the exposure start timing by the laser beam based on the leading edge position of the paper P detected by the paper leading edge detection means 30. That is, since the position of the paper detection sensor 10 and the exposure position by the laser beam are determined by design, if the leading end position of the paper P is known, the exposure start timing detection means 33a calculates the exposure start timing at the exposure position. Can do. The paper rear end escape detecting means 33b is for detecting that the rear end of the paper P for which image printing exposure has been completed has escaped from the exposure position.

  The exposure control unit 34 is configured to start image exposure with laser light based on the calculation result of the exposure timing by the exposure start timing detection unit 33a. Thus, the latent image can be formed by scanning the emulsion surface of the paper P with the laser light light-modulated by the image data.

  The roller driving unit 36 rotates the conveyance roller pair 12 a of the conveyance unit 12 and is controlled by the conveyance unit drive control unit 37.

  The transport unit drive control means 37 performs drive control of the transport unit 12 (roller drive means 36) based on information from the paper position detection unit 33 and drives the guide plate via the guide plate control means 46. Drive control of the motor 19a of the mechanism 19 is performed.

  Note that the control block shown in FIG. 3 can be constructed by the function of computer software or hardware. Which function is realized by software and which function is realized by hardware can be appropriately determined according to the paper processing capability and the like.

  Next, the configuration of the laser unit 71 will be described with reference to FIG. The laser light source 72R disposed in the laser unit 71 is configured by a semiconductor laser (LD) that emits red laser light having a wavelength of 680 nm, for example. The laser light source 72G includes a semiconductor laser and a second harmonic generator (SHG) that converts laser light emitted from the semiconductor laser into green laser light of 532 nm, for example. The laser light source 72B includes a semiconductor laser and a second harmonic generator (SHG) that converts laser light emitted from the semiconductor laser into blue laser light having a wavelength of 473 nm, for example.

  In the laser unit 71, acousto-optic modulation elements (hereinafter referred to as AOMs) 73R, 73G, and 73B that modulate the intensity of the laser light are respectively disposed on the output sides of the laser light sources 72R, 72G, and 72B. In addition, the mirrors 74R, 74G, and 74B, the reflection mirror 75 that reflects the laser light from the mirrors 74R, 74G, and 74B, and the laser light from the reflection mirror 75 are scanned in the arrow B direction within a predetermined range. Polygon mirrors 76 are arranged in order.

  The AOMs 73R, 73G, and 73B adjust the laser beams having a certain intensity supplied from the laser light sources 72R, 72G, and 72B in the range of 0 to 100%, respectively.

  The mirror 74R is a total reflection mirror, and the mirrors 74G and 74B are half mirrors. Then, the laser beam from the AOM 73R is totally reflected by the mirror 74R, combined with the laser beam from the AOM 73G by the mirror 74G, and then combined with the laser beam from the AOM 73B by the mirror 74B. Color laser beams are combined. The combined laser light is reflected by the reflection mirror 75 and enters the polygon mirror 76.

  The polygon mirror 76 is rotated in the direction of arrow C at a constant angular velocity, so that the incident laser light is conveyed in the direction of arrow D (see FIG. 1: the direction in front of the page in FIG. 2) by the exposure conveyance roller 9. The emulsion surface of the paper P is scanned from one end to the other end in the paper width direction in the arrow B direction.

  Further, the moving speed (scanning speed) of the laser beam scanned on the emulsion surface of the paper P by the rotation of the polygon mirror 76 is constant in the portion between the polygon mirror 76 and the paper P in the laser unit 71. An fθ lens 77 is provided to keep the lens. The laser light that has passed through the fθ lens 77 is emitted to the outside of the laser unit 71 from a light emission port 71 a provided on the lower surface of the laser unit 71.

  A light guide unit 63 is provided on the lower surface of the laser unit 71 so as to protrude downward. The light guide unit 63 is formed of a cylindrical member having a substantially rectangular cross section, is connected to the light exit port 71a, and is connected to the lower surface of the laser unit 71 from the lower side of the exposure transport roller 9. It extends to a nearby position. Thus, the light guide unit 63 plays a role of guiding the laser light emitted from the light emission port 71a onto the emulsion surface of the paper P being conveyed by the upstream and downstream exposure conveying rollers 9a and 9b. . The lower surface (light emitting surface) of the light guide unit 63 is made of glass, and prevents dust and dirt from entering the light guide unit 63. Thus, since the laser unit 71 is located above the exposure position and the upstream side conveyance unit 17, the light exit surface of the light guide unit 63 can be directed downward, whereby dust or dust is deposited on the light exit surface. It becomes difficult to adhere.

  A cooling unit 65 for cooling the laser unit 71 is disposed at a position adjacent to the laser unit 71 on the lower side. The cooling unit 65 is a part through which cool air blown by a fan (not shown) passes, and the lower surface of the laser unit 71 is cooled by the cool air, thereby suppressing a temperature rise in the laser unit 71, and The characteristic change (mode hopping etc.) of the laser light sources 72R, 72G, 72B is prevented from occurring. The cooling part 65 may be part of the loop part accommodation space W or between the loop part accommodation space W and the laser unit 71.

  As described above, according to the present embodiment, an image is formed on the emulsion surface of the paper P in a state in which the paper P is connected between the supply unit 1 and the exposure engine 7 without being cut by the paper cutter 5. Since the upstream loop portion Pa slacking upward is formed in the portion of the paper P between the supply unit 1 and the exposure engine 7, the paper P is transported by the exposure transport roller 9. Even if the supply of the paper P from the supply unit 1 is stopped for cutting the paper P during the exposure (that is, during the exposure), the load fluctuation due to the stop is transmitted to the exposure position of the paper P. In addition, the load fluctuation due to the cutting of the paper P itself is not transmitted. Therefore, a long conveyance path is not required as a pre-exposure buffer (upstream buffer of the exposure position), and the length of the upstream conveyance unit 17, that is, the distance between the supply unit 1 and the exposure position can be shortened. . Further, since the supply unit 1 and the downstream transport unit 18 are formed vertically long, the length of the image forming apparatus A in the left-right direction is shortened in combination with the shortening of the length of the upstream transport unit 17. can do. Thereby, the installation space of the image forming apparatus A can be reduced. In addition, the upstream transport unit 17 is at a height below the center in the vertical direction of the supply unit 1, and a gap corresponding to the scanning amount of the laser light is required between the upstream transport unit 17 and the laser unit 71. Therefore, a certain amount of space exists above the upstream transport unit 17, and the loop portion accommodation space W can be easily formed in the space. Therefore, the image forming apparatus A can be downsized in the vertical direction. Therefore, it is possible to obtain a high-quality image while reducing the size of the image forming apparatus A.

  Further, since the outer side surface of the upstream loop portion Pa and the outer side surface of the roll R accommodated in the paper magazine 3 are both image forming surfaces, the upstream side is caused by the curl generated when being accommodated in the paper magazine 3. The loop portion Pa can be easily formed.

  Further, since the downstream side loop portion Pb is formed in the turn portion of the paper P turned by the guide member 16 in the downstream side conveyance portion 18, vibrations and load fluctuations in the development processing portion are caused at the exposure position. It is possible to prevent transmission. That is, if the length of the paper P is longer than the distance from the exposure position to the development processing unit, the paper P enters the development processing unit during exposure, and the vibration generated by the processing in the development processing unit Although it is transmitted to the P exposure position and causes uneven exposure, the formation of the downstream loop portion Pb as in this embodiment can reliably prevent such exposure unevenness from occurring. The size of the downstream loop portion Pb may be considerably small. In some cases, the downstream loop portion Pb may not be formed. However, even in this case, the guide plate 16a needs to be in the non-guide position after the leading end of the paper P has passed. That is, the turn portion plays the same role as the loop portion, and vibrations and load fluctuations in the development processing portion are absorbed by the turn portion. By forming the downstream loop portion Pb in such a turn portion, the absorption can be ensured. Therefore, it is possible to secure a post-exposure buffer (a buffer on the downstream side of the exposure position) that can sufficiently prevent occurrence of uneven exposure without lengthening the transport path in the downstream side transport unit 18.

  Furthermore, since the laser unit 71 is located above the loop portion accommodation space W, the distance between the fθ lens 77 and the paper P at the exposure position is increased by the height of the loop portion accommodation space W. be able to. Thereby, the focal length of the fθ lens 77 can be made relatively long, and even the paper P having a considerably large width (for example, about 600 mm) can be handled by the inexpensive fθ lens 77. That is, if the focal length of the fθ lens 77 is small when the width size is considerably large, it is necessary to increase the deflection angle of the laser beam by the polygon mirror 76, and the region that is largely deviated from the optical axis in the fθ lens 77 accordingly. Will have to use. In the region deviated from the optical axis of the fθ lens 77, shading is likely to occur due to chromatic aberration, curvature of field, reflection on the image forming surface of the image forming medium, and the like. High accuracy is required, which increases manufacturing costs. On the other hand, if the focal length is increased, the deflection angle can be reduced even when the width size is considerably large, and it is not necessary to use a region that is largely deviated from the optical axis in the fθ lens 77. Therefore, in the present embodiment, the manufacturing cost of the fθ lens 77 can be reduced while dealing with the paper P having a considerably large width size.

(Other embodiments)
The configuration of the present invention is not limited to the above embodiment, and includes various other configurations. For example, in the embodiment, the supply unit 1 is provided with the two magazine loading units 1a and 1a. However, one or more magazine loading units may be provided.

  Further, the image forming apparatus of the present invention is not limited to the photographic image forming apparatus (photographic processing apparatus) used in the photographic processing system as in the above-described embodiment, and is supplied from the supply unit that supplies the image forming medium and the supply unit. An upstream conveying unit that conveys the image forming medium formed, an image forming unit that forms an image on the image forming surface of the image forming medium conveyed from the upstream conveying unit, and a conveyance downstream side of the image forming unit The present invention can be applied to any image forming apparatus as long as the image forming apparatus is provided with a downstream transport unit that transports the image forming medium fed from the image forming unit. .

  INDUSTRIAL APPLICABILITY The present invention is useful for an image forming apparatus that forms an image on an image forming surface of an image forming medium while conveying the image forming medium, and in particular, an image forming made of a photosensitive material by irradiation with light such as laser light. It is useful for a photographic image forming apparatus (photographic processing apparatus) that forms a latent image on the image forming surface of a medium.

1 is a partial cross-sectional view illustrating a configuration of a photographic processing system including an image forming apparatus according to an embodiment of the present invention. It is a principal part enlarged view which shows the structure of a downstream conveyance part. FIG. 3 is a diagram illustrating a control block configuration of the image forming apparatus. It is the schematic which shows the structure of a laser unit. FIG. 2 is a view corresponding to FIG. 1 illustrating a state in which an upstream loop portion that is slacked upward is formed in a portion of the paper between the supply portion and the exposure engine.

Explanation of symbols

A Image forming apparatus P Paper (image forming medium)
Pa Upstream loop part Pb Downstream loop part W Loop part accommodation space 1 Supply part 1a Magazine loading part 3 Paper magazine (container)
5 Paper cutter (cutting device)
6 Transport unit (Upstream transport section transport mechanism)
7 Exposure engine (image forming unit)
17 Upstream transport section 18 Downstream transport section

Claims (4)

A supply unit for supplying an image forming medium;
An upstream conveyance unit including a conveyance mechanism that conveys the image forming medium supplied from the supply unit in a substantially horizontal direction at a height position equal to or lower than the center in the vertical direction of the supply unit;
An image forming unit that forms an image on an image forming surface of the image forming medium while conveying the image forming medium conveyed by the conveying mechanism of the upstream conveying unit in an extension direction of the conveying direction by the conveying mechanism; ,
A downstream conveyance unit that is arranged to extend in the vertical direction on the conveyance downstream side of the image forming unit, and conveys the image forming medium fed from the image formation unit,
A cutting device for cutting the image forming medium into a predetermined length is disposed between the supply unit and the upstream transport unit,
When an image is formed on the image forming surface of the image forming medium in a state where the image forming medium is connected between the supply unit and the image forming unit without being cut by the cutting device. In the part of the forming medium between the supply part and the image forming part, an upstream loop part that sags upward is formed,
An image forming apparatus, wherein a loop portion accommodation space for accommodating the upstream loop portion is provided above the upstream conveyance portion. The image forming apparatus according to claim 1.
The supply unit includes a plurality of loading units in which containers accommodated in a state where the image forming medium is wound in a roll shape are loaded, and the plurality of loading units are respectively loaded in the plurality of loading units. Configured to selectively supply an image forming medium from any one of the above,
The image forming apparatus, wherein the plurality of loading units are arranged in the vertical direction in the supply unit. The image forming apparatus according to claim 1 or 2,
The image forming apparatus according to claim 1, wherein the downstream transport unit includes a turn unit that turns the image forming medium fed from the image forming unit upward. The image forming apparatus according to claim 3.
An image forming apparatus, wherein a downstream loop portion is formed in the turn portion of the image forming medium turned by the turning means.

Images