JP2007017677A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which is used without causing jam and curl or the like in such a state that a plurality of recording media are stored in a housing part regardless of the kind of the recording medium, which achieves space saving, and concurrently whose number of components is reduced. <P>SOLUTION: The image forming apparatus is equipped with a recording medium conveying means for conveying the recording medium P from a recording medium housing part 20 to an image forming part 10 and an ejection part 40. A conveying path TP from conveying the recording medium in a housed state in the recording medium housing part to the image forming part to ejecting it is arranged to be nearly linear and nearly in a vertical direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and a composite machine for forming an image on a recording medium such as paper or an OHP sheet. In particular, the invention can prevent jamming of the recording medium and reduce curling. The present invention relates to an image forming apparatus capable of reducing the size and cost of the apparatus.

  An image forming apparatus configured as a copying machine, a printer, a facsimile machine, or a multifunction machine having at least one of these functions generally includes a recording medium storage unit that stores a recording medium such as paper or an OHP sheet on which an image is formed. An image forming unit that forms an image on the recording medium, a discharging unit that discharges the recording medium on which the image is formed, and a recording medium transport that transports the recording medium from the recording medium storage unit to the image forming unit and the discharging unit. The means is a basic configuration. Usually, a power supply unit and a control unit that controls image data processing and processes are also provided. In addition, an apparatus having a copying function includes an image reading unit that reads a document.

  In a conventional general image forming apparatus, one or a plurality of paper feed cassettes are arranged at the lower part of the apparatus as a recording medium storage unit, and a plurality of recording media are horizontally stacked and stored. The recording media are separated one by one from above the recording media stored in the paper feed cassette by the recording medium conveying means, and conveyed to the image forming unit. The recording medium conveyed to the image forming unit forms a desired image, is conveyed by a recording medium conveying unit to a discharge unit disposed on the upper part of the apparatus, and stacked on the discharge tray in a horizontal or slightly inclined state. .

  Among such image forming apparatuses, when attention is paid to the transport path of the recording medium, there is an image forming apparatus that is transported from a paper feed cassette disposed at a lower portion of the apparatus to an image forming unit disposed in a horizontal direction. For example, in Patent Document 1, in an image forming apparatus having an intermediate transfer member, a transfer material conveyance path from a transfer material supply position to a discharge position is formed so as to linearly convey the transfer material in the horizontal direction.

  On the other hand, there are some which are conveyed from a paper feed cassette arranged at the lower part of the apparatus to an image forming unit arranged in the vertical direction. The image forming apparatus disclosed in Patent Document 2 includes a vertical conveyance device that conveys a sheet from the bottom to the top, and fixes the image to the sheet in the middle of the conveyance, and a post-processing device, and has a relay conveyance path. It has a discharge receiving surface whose height decreases toward the top, has a plurality of vent holes, and has a taper portion extending toward the lowermost portion in the vent hole. Further, in Patent Document 3, a sheet conveyance path from a paper feeding unit to a fixing unit is formed as a vertical conveyance path extending in a substantially vertical direction, and an opening / closing portion is provided at one end of the apparatus main body. A featured image forming apparatus is disclosed.

  An example of this type of image forming apparatus is shown in a side sectional view in FIG. The printer apparatus 100Z includes four process units 6Y, M, C, and BK, and four exposure apparatuses 7Y, M, C, and BK corresponding to the process units 6Y, M, C, and BK, respectively. Each belt unit includes four transfer rollers 15Y, 15M, 15C, and 15B. Also, two paper feed cassettes 26 and a roll paper supply device 70 that is disposed under these paper cassettes and supplies the roll paper RP are provided.

  The process units 6Y, 6M, 6C, and 6B are for forming Y (yellow), M (magenta), C (cyan), and BK (black) toner images, respectively, except that the colors of the toners used are different. Has almost the same configuration. The process unit 6Y for yellow will be described as an example. As shown in FIG. 9, a photosensitive drum 1Y, a drum cleaning device 2Y, a charge removal device 3Y, a charging device 4Y, a developing device 5Y, and the like are provided. The charging device 4Y uniformly charges the surface of the photosensitive drum 1Y that is rotated clockwise in the drawing by a driving unit (not shown). The surface of the photosensitive drum 1Y that is uniformly charged in this way is exposed by the exposure device 7Y and carries a Y electrostatic latent image. The Y electrostatic latent image is developed into a Y toner image by the developing device 5Y using Y toner. Then, intermediate transfer is performed on the intermediate transfer belt 18 of the intermediate transfer unit. On the other hand, the drum cleaning device 2Y removes the toner remaining on the photosensitive drum 1Y after the transfer of the Y toner image. Further, the charge removal device 3Y removes the residual charge on the photosensitive drum 1Y after cleaning. By this charge removal, the surface of the photosensitive drum 1Y is initialized and prepared for the next image formation. In other process units 6M, C, and BK, M, C, and K toner images are similarly formed on the photosensitive drum, and are sequentially superimposed on the intermediate transfer bell 18 and intermediate transferred.

  As described above, the intermediate transfer unit includes the four transfer rollers 7Y, M, C, and BK. These are for transferring toner images from the Y, M, C, and BK photosensitive drums to the intermediate transfer belt, respectively, and forming Y, M, C, and BK transfer nips with the photosensitive drums. is doing. At each transfer nip, a transfer electric field is formed by a transfer roller to which an intermediate transfer bias is applied from a power source (not shown) contacting the back surface of the belt. The intermediate transfer belt 18 is moved endlessly counterclockwise in the drawing. In each transfer nip, Y, M, C, and BK toner images are sequentially superimposed and transferred intermediately. By this superposition transfer, a toner image is formed on the intermediate transfer belt 18 by superimposing four colors. This toner image is secondarily transferred collectively onto the surface of the transfer paper P when passing through a position facing the transfer charger 17 as the belt moves endlessly. A full color image is formed by being transferred onto the white transfer paper P.

  Above the belt unit, there is a heat fixing device 30 comprising a fixing roller having a heat source such as a heater inside, a pressure roller that abuts against this with a predetermined pressure and elastically deforms to form a fixing nip. It is arranged. The transfer paper P peeled off from the intermediate transfer belt is sent into the heat fixing device 30. Then, the toner image on the transfer paper P is fixed by being sandwiched by the fixing nip and heated or pressurized, and then sent to the discharge path 33. The discharge path 33 receives the transfer paper P sent from the heat fixing device 30 in the vertical direction, changes the moving direction to a direction close to the horizontal direction, and then sends the transfer paper P toward the discharge device 34. The discharge device 34 discharges the transfer paper P received from the discharge path 33 toward the upper surface of the printer housing. On this upper surface, a stack portion 40 is formed so as to have an upward slope with respect to the discharge direction of the transfer paper P, and the transfer paper P discharged from the discharge device 34 is sequentially stacked on the stack portion 40.

  The exemplary apparatus 100Z having the above-described configuration can form a full-color image on the transfer paper P by a so-called tandem method. The tandem system is a system in which each monochrome toner image for superposition is formed by a dedicated image carrier (photosensitive drum or the like). In addition to the tandem method, there is a division method that forms a full-color image using only one image carrier. In the tandem device, each color toner image is processed in parallel by each process unit 6Y, M, C, BK. By forming, a full-color image can be formed only by rotating the intermediate transfer belt 18 once, and the formation speed of the full-color image can be greatly reduced as compared with the division type apparatus. In the exemplary apparatus, as shown in FIG. 8, the photosensitive drums 1Y, 1M, 1C, and 1B are arranged on a straight line. Further, the alignment direction of the photosensitive drums 1Y, 1M, 1C, and 1B is set to the vertical direction, and the color toner images are transferred to the transfer paper P while the transfer paper P is conveyed in the vertical direction. . Patent Document 4 discloses a printer device having a structure similar to that of the image forming apparatus described above (however, a toner image can be formed on both sides to enable simultaneous fixing).

  By the way, in the above-described conventional image forming apparatus, in any case, since the recording medium is transported from the horizontal state in the paper feed cassette to the image forming unit located in the upward direction, the transport path needs to be bent. The corner portion of the transport path causes jamming and curling of the recording medium. In particular, when the recording medium is thick, it is difficult to bend and cannot be transported, and conversely, when the recording medium is thin, it is likely to be caught at the corner and jammed. For this reason, in the case of thick paper and thin paper, the user has to make a response such as selecting a mode and using a manual feed tray, which is complicated and inefficient.

  Therefore, in the disclosed technique of Patent Document 5, a straight traveling path for transporting and discharging a sheet after image formation is provided so that a jam, a crease, or a wrinkle is generated when a thick sheet or a special sheet is passed through the apparatus. The generation is prevented. In the image forming apparatus disclosed in Patent Document 6, the first image forming unit (3) that forms the first toner image on one surface of the sheet material and the surface on which the first toner image is formed A first conveying means (4) for carrying and conveying the opposite surface of the sheet material, a first fixing device (5) for fixing the first toner image, and the other surface of the sheet material On the other hand, a second image forming section (6) for forming a second toner image, and a second conveying means (7) for sucking and conveying the surface of the sheet material on the side where the first toner image is formed. ) And a second fixing device (8) for fixing the second toner image, and these constituent elements are provided so that the sheet material conveyance path is substantially straight. As a result, since the sheet material is conveyed almost linearly in the image forming apparatus, it can be conveyed without forcing the sheet material to have an uncomfortable posture. It is said that an image forming apparatus that can be copied and printed on both sides and is easy to use can be provided.

  In addition to the above-mentioned paper jam and folding problems, there is a limitation on the area of the recording medium in the conventional apparatus for horizontally storing or discharging the recording medium, and there is a limit to reducing the installation area. . The demand for downsizing and space saving in image forming apparatuses is also increasing, and as a countermeasure, many apparatuses for storing recording media vertically have been proposed.

  For example, Patent Document 7 discloses that a vertical sheet feeding apparatus that feeds sheets one by one from a stack of recording sheets set in a vertical form is provided with a recording sheet separating unit and a buckling prevention unit. A paper device is disclosed.

Further, in Patent Document 8, a vertical paper feed unit that is disposed in a vertical direction with respect to the image forming unit, stores and feeds paper in an upright state, and is disposed in a vertical direction with respect to the image forming unit. An image forming apparatus including a paper storage unit for storing discharged paper is disclosed.

  However, even in these apparatuses for storing the recording medium vertically, jamming and curling of the recording medium are not particularly taken into consideration, and the conveyance path has a complicated corner portion. Such a complicated conveyance path causes jamming and curling of the recording medium, and also increases the number of parts such as a conveyance roller and a guide, thereby causing an increase in cost. In addition, in the apparatus disclosed in Patent Document 9, the recording medium P before image formation is supported in the vertical direction to reduce the occupation area of the apparatus main body.

Japanese Patent No. 3518864 Japanese Patent Laid-Open No. 2003-40508 JP 2003-186371 A JP 2002-341675 A JP-A-2-175556 JP-A-11-327218 JP-A-6-72563 JP 11-278742 A Japanese Patent Laid-Open No. 7-334065

  The present invention has been made in view of the above-described problems, and enables the space-saving of the apparatus by making a vertical type from the storage state of the recording medium to the paper discharge, and further stores the recording medium regardless of the type of recording medium. It is an object of the present invention to provide an image forming apparatus that can be used without being jammed or curled in a state where a plurality of sheets are stored in a part. In addition, the object is to further reduce the number of parts.

  In order to solve the problem, in the present invention, a recording medium storage unit that stores a recording medium, an image forming unit that forms an image on the recording medium, a discharge unit that discharges the recording medium on which an image is formed, and a recording medium that records the recording medium An image forming apparatus that includes a recording medium conveying unit that conveys from a medium storage unit to the image forming unit and the discharge unit, and forms an image on the recording medium. In the image forming apparatus, the recording medium stored in the recording medium storage unit forms an image. The conveyance path until it is conveyed to the section and discharged is arranged in a substantially straight line and in a substantially vertical direction. Accordingly, since the recording medium is conveyed in a substantially straight line, the recording medium on which the image is formed does not curl and jamming is less likely to occur. Since there is no complicated conveyance path, it is possible to reduce the number of rollers and guide parts involved in the conveyance, and the number of parts can be reduced. The installation area is also reduced by using the vertical type.

  Further, the invention is characterized in that the recording medium conveyance direction of the conveyance path is from top to bottom. Gravity can be used by moving the transport from top to bottom, the transport mechanism can be simplified, and the number of parts can be further reduced. Alternatively, the recording medium conveyance direction of the conveyance path is from bottom to top. Since the image-formed recording medium is discharged upward, the recording medium can be easily taken out and the usability is improved.

  The recording medium storage unit, the image forming unit, and the discharge unit can be separated for each unit, and the conveyance direction of the recording medium can be selected depending on the vertical direction and combination of the units. Various types of image forming devices that change the configuration of the device and the vertical direction (orientation) of the transport path, etc., can be designed with low man-hours by improving the flexibility of the device configuration and selecting and combining appropriate units. It can be supplied and the user can select it according to his / her preference.

  In the image forming apparatus according to the present invention, the installation area can be reduced by using the vertical type, and in particular, since the recording medium is conveyed in a substantially straight line, the recording medium on which the image is formed does not curl and jamming hardly occurs. Further, since there is no complicated conveyance path, it is possible to reduce rollers and guide parts related to conveyance.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram (side sectional view) showing a configuration of an electrophotographic color printer as a first embodiment of an image forming apparatus according to the present invention. As shown in FIG. 1, an image forming apparatus (color printer) 100A includes an image forming unit 10 that is positioned substantially in the center of the apparatus main body, a (recording medium) storage unit 20 that is positioned below the image forming unit, and an image. A paper discharge unit 40 is provided above the forming unit. A fixing unit 30 is provided on the downstream side (upper side in FIG. 1) of the image forming unit 10 in the transport direction. Reference sign BS indicates a desk or other base on which the apparatus is installed. The image forming unit 10, the (recording medium) storage unit 20, and the paper discharge unit 40 are configured to be separable as a unit. Hereinafter, the configuration and operation of the principal part of the printer apparatus will be described with reference to FIG. The details of the general components equivalent to the apparatus of FIG. 8 described above, which are not related to the invention, are not shown and described.

  The storage unit 20 feeds paper sheets 26A for storing paper, OHP sheets, and the like as recording media P, and feeds the recording media P in the paper feeding cassettes one by one from the top. The sheet roller 25 and a pair of conveying rollers 27 and 27 for conveying the fed recording medium P are sequentially sent out to the image forming unit 10. The paper feed cassette 26A is placed vertically and accommodates the recording medium P vertically or slightly inclined so that the surface of the recording medium P is positioned on a substantially straight line with respect to the conveying belt 13 of the image forming unit 10. Yes.

  The image forming unit 10 is provided with a conveyor belt 13 that adsorbs and conveys a recording medium extending in the vertical direction, and a configuration (process unit) 6Y, M for forming an image on the opposite surface of the conveyor belt 13. , C, BK are provided. That is, four photoconductors (7Y, M, C, BK) as image carriers capable of carrying images of four kinds of toners (yellow, magenta, cyan, black) that form images are provided along the conveyance belt 13. Are juxtaposed.

  Each photoconductor (drum) 1Y, M, C, BK (hereinafter collectively referred to as the photoconductor 1) is composed of a drum that can rotate in the same direction (counterclockwise direction). Similarly to the case shown in FIG. 14, if the yellow process unit 6Y is taken as an example, the drum cleaning device 2Y, the charge eliminating device 3Y, the charging device 4Y, the developing device 5Y, and the image forming process in the rotation process, A writing device as an optical writing unit, a transfer device 16 and the like are arranged. Each developing device 5Y, M, C, and BK contains respective toner. The conveying belt 13 is configured to be wound around the driving roller 11 and the supporting roller 12 and move in the same direction as the photosensitive member 1 at a position facing the photosensitive member.

  The surface of the photoconductor 1 is uniformly charged by the charging device 4 and an electrostatic latent image is formed on the photoconductor 1 by writing with a writing device such as an LD or an LED array (no indication) based on the image information. . The electrostatic latent image is visualized as a toner image by the developing device 5 containing toner.

  The recording medium P fed from the storage unit 20 is fed onto the conveying belt 13 by the registration roller pairs 28 and 28 at the timing when the position of the image coincides with a predetermined position of the recording medium, and is attracted by an electrostatic method or the like. Fixed. The toner image formed on the photosensitive member is transferred to the recording medium P adsorbed on the conveying belt 13 by a transfer device (transfer roller) 16 to which a predetermined bias is applied. A similar image is formed on the photoreceptor 1 of each color toner, and the respective toner images are sequentially transferred onto the recording medium and superimposed.

  The recording medium P to which the image has been transferred is composed of a pair of rollers (heat-fixing rollers 30a and 30b) forming a nip, and is conveyed to a fixing device 30 controlled to a set temperature, and the toner image on the recording medium is heated. Then, it is melted and fixed on the recording medium P.

  The toner remaining on the photoconductor after the transfer is removed by the cleaning device 2, and after the transfer, the electric potential of the photoconductor is initialized by a static elimination lamp (static elimination device) (not shown), and in the next image forming process. Provided.

  The process unit (image forming unit) 6 provided with each photoconductor is selected and used in accordance with a single color or a plurality of color image forming modes, and an image forming unit corresponding to the selected image forming mode is used. The unit performs the above-described image forming process.

  The recording medium on which the toner image is fixed in the image forming unit 10 is transported to the paper discharge unit 40 by the paper discharge roller 43, and is stacked and stored on the paper discharge tray 41 so that the paper surface is substantially linear with respect to the transport path direction. Is done. The paper discharge tray 41 is vertically or slightly inclined so that the tray surface faces upward. The holding roller presses the recording medium against the paper discharge tray so that the recording medium P does not fall down or fall apart. 42A is provided.

  Thus, in the apparatus of the present embodiment, the recording medium transport path TP is substantially linear throughout, and the recording medium P is transported without being bent during the image forming process, so that the recording medium P is not easily curled. In addition, the occurrence of jam can be reduced to almost none. Although not shown in the drawings, the appropriate conveyance guide members constituting the conveyance path TP are complicated and do not require any special shape, and the conveyance rollers can reduce the number of necessary points. Is extremely simple and the cost can be reduced. Furthermore, since the conveying direction is vertical and the storage of the recording medium is vertical, the installation area of the apparatus is not limited by the area of the recording medium, and a large space saving is possible.

[Second Embodiment]
FIG. 2 shows an image forming apparatus 100B according to the second embodiment. In this embodiment, a double-sided printing mechanism including a double-sided printing transport path RTP is further added to the configuration equivalent to that of the image forming apparatus of the first embodiment. In the case of single-sided printing, an image is formed on the first side of the recording medium P and discharged by exactly the same operation as in the first embodiment, and thus the description thereof is omitted.

  Even in duplex printing, the recording medium is fed from the storage unit to the image forming unit, the toner image is transferred to the first surface of the recording medium, the toner image is fixed on the recording medium through the fixing device, and is discharged. The operation until it is sent to the unit 40 is the same. Then, after the image is formed on the first surface, the recording medium P that has come to the discharge unit 40 is conveyed halfway by the discharge roller 43, and the traveling direction is detected before the trailing edge of the recording medium P is detected and passes through the discharge roller 43. Reversely, the path is switched to the duplex printing transport path RTP, and the center of the apparatus is sent from the top to the bottom. Then, the recording medium P changes its direction through the reversal guiding path portion at the lower end of the path, the printing surface is reversed and sent to the image forming unit 10 again, and the toner image is transferred and fixed on the second surface (back side surface). Then, it is sent out to the paper discharge tray 41. As described above, in the case of double-sided printing, the corner portion is inevitably required only for the reversal guide path portion of the recording medium, but in other cases, the conveyance path RTP for double-sided printing is also substantially linear, so jamming and curling occur. It is difficult to do.

[Third Embodiment]
The image forming apparatus 100C of the third embodiment shown in FIG. 3 uses an intermediate transfer system as the image forming unit 10A. Two storage cassettes (26A, 26B) are set in the storage section 20A, and can be selectively used depending on the type or size of the recording medium. The two paper feed cassettes 26A and 26B are installed so that the paper feed and take-out sides of the recording medium face each other, and the recording medium P at the take-out portion does not have a corner portion in the transport path TP when feeding from either paper feed cassette. However, it is arranged so as to be positioned substantially on a straight line with the conveyance path of each functional unit arranged along the conveyance path TP.

  As in the first to third embodiments described so far, in the image forming apparatus in which the transport direction (transport direction) of the transport path is from bottom to top, in addition to the above effects, the image forming unit is not sensitive. Since the image forming process of the body and the like is under the fixing process, there is an advantage that the photoconductor and the developing device are hardly affected by the heat of the fixing device. In addition, when installed on the floor, there is also a merit that it is easy to take out the recording medium on which the image is formed from the apparatus because the discharge portion is positioned at an appropriate height.

[Fourth Embodiment]
An image forming apparatus 100D of the fourth embodiment shown in FIG. 4 is obtained by inverting the image forming unit of the first embodiment upside down and assembling a downward discharge unit at the bottom and a downward storage unit at the top. . When the image forming apparatus is placed on a desk or shelf according to the user's usage, for example, it may be easier to take out the paper discharge unit at the bottom. good. Further, when the transport direction of the transport path is from the top to the bottom as in this embodiment, the paper discharge unit only needs to drop the recording medium from the image forming unit, so a mechanism such as transport is unnecessary and the configuration is simplified. There is also a merit that

[Fifth Embodiment]
The fifth embodiment shown in FIG. 5 is an image forming apparatus 100E that includes a double-sided printing mechanism and has a recording medium transport direction from top to bottom. In the process of transferring the toner image to the recording medium, since the conveyance path is vertical and from top to bottom, the recording medium can maintain straightness by its own weight even without a conveyance belt. This greatly simplifies the recording medium transport mechanism.

[Sixth Embodiment]
In the embodiments described so far, the color tandem electrophotographic image forming apparatus has been described. However, a single-color (monochrome) image forming apparatus has already been described by using a vertical and substantially linear conveyance path. As a result, the effect of preventing jamming and curling of the recording medium and the space saving effect by reducing the installation area can be obtained. An example of the configuration in this case is shown in FIG. The image forming apparatus 100F is different only in that the image forming unit has a known configuration corresponding to a single color. Note that the conveyance direction (direction) of the recording medium is from top to bottom.

[Seventh Embodiment]
Further, the present invention can be widely applied to image forming apparatuses (inkjet system, thermal printer system, etc.) other than the electrophotographic image forming apparatus described so far. An embodiment in this case is shown in FIG. In the image forming apparatus 100G of the present embodiment, the image forming unit 10B employs an ink jet method, and is configured around an ink jet type print head 19. In this embodiment as well, the conveyance path TP of the recording medium P is substantially linear throughout, and the recording medium P is less likely to curl and jamming is reduced correspondingly. The same effect is naturally obtained. A thermal printer using a thermal head can be similarly configured.

  As described above, according to the embodiment, in the present invention, since the recording medium is conveyed from the stored state to the image forming unit and discharged, the conveyance path is substantially linear and substantially vertical. It is possible to provide an image forming apparatus that can prevent jamming and curling regardless of the type of medium, can reduce the number of parts, and can save space by reducing the installation area.

  The image forming unit 10, the (recording medium) storage unit 20, and the paper discharge unit 40 according to the present invention are configured as separate units. Therefore, each unit can be connected by changing the order of the units so that the conveyance direction of the recording medium P can be either up or down (orientation), and if necessary, it can function in an upside down posture. It is possible to keep it. In this way, the recording medium conveyance direction can be selected depending on the vertical direction and combination of the units, and the degree of freedom of the apparatus configuration is improved. By selecting and combining appropriate units, various types of image forming apparatuses in which the configuration of the apparatus and the vertical direction (orientation) of the conveyance path are changed can be designed and supplied with low man-hours.

1 is a side sectional view of an image forming apparatus according to a first embodiment of the present invention. It is a sectional side view of the image forming apparatus in 2nd Embodiment of this invention. It is a sectional side view of the image forming apparatus in 3rd Embodiment of this invention. It is a sectional side view of the image forming apparatus in 4th Embodiment of this invention. It is a sectional side view of the image forming apparatus in 5th Embodiment of this invention. It is a sectional side view of the image forming apparatus in 6th Embodiment of this invention. It is a sectional side view of the image forming apparatus in 7th Embodiment of this invention. It is a sectional side view of the conventional image forming apparatus (printer). It is an enlarged block diagram which shows the process unit for yellow in the apparatus of FIG.

Explanation of symbols

1 (1Y,...) ... photosensitive drum (image carrier)
2 (2Y,...) ... Drum cleaning device 3 (3Y,...) Y ... Static elimination device 4 (4Y,...) Y ... Charging device 5 (5Y,...) Y ... Developing device 6 (6Y,. Imaging Department)
10: Image forming unit 11: Driving roller (stretching member)
12 ... Support roller (stretching member)
13 ... Conveyor belt 16 ... Transfer device (transfer roller)
18 ... Intermediate transfer belt 19 ... Print head 20 ... (Recording medium) storage unit 25 ... Paper feed rollers 26A, 26B ... Paper feed cassette (supply means)
27 ... Conveying roller (pair)
27: Paper feed roller 28: Registration roller (pair)
30... Fixing portions 30 a and 30 b... Heating and fixing roller 40... Paper discharge portion 41.
42A ... holding roller 42B ... holding member 43 ... paper discharge rollers 100A to 100G ... printer (image forming apparatus)
TP ... transport path RTP ... transport path P for double-sided printing ... transfer paper (recording medium)
RP ... Roll paper (non-standard size recording medium)

Claims (4)

A recording medium storage unit for storing the recording medium;
An image forming unit for forming an image on a recording medium;
A discharge unit for discharging the image-recorded recording medium;
A recording medium conveying means for conveying the recording medium from the recording medium storage unit to the image forming unit and the discharge unit;
In an image forming apparatus for forming an image on a recording medium,
An image forming apparatus, wherein the recording medium stored in the recording medium storage unit is transported to the image forming unit, and the transport path until the recording medium is discharged is substantially linear and arranged in a substantially vertical direction.   The image forming apparatus according to claim 1, wherein a recording medium conveyance direction of the conveyance path is from top to bottom.   The image forming apparatus according to claim 1, wherein a recording medium conveyance direction of the conveyance path is from bottom to top. 2. The recording medium storage unit, the image forming unit, and the discharge unit are separable for each unit, and the conveyance direction of the recording medium can be selected by the vertical direction and combination of each unit. The image forming apparatus described in 1.

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