JP4190474B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to a vertical image forming apparatus, and more particularly to an image forming apparatus such as a copying machine or a printer in which a sheet on which an image is formed is conveyed substantially upright.

  2. Description of the Related Art In recent years, image forming apparatuses such as copying machines and printers are widely used by companies and individuals, and are installed in a wide variety of places. Depending on the installation location, it may be desirable that the installation area of the image forming apparatus is as small as possible. For example, when the image forming apparatus is placed on a desk, it is desirable that the installation area be as small as possible in order to use the desk widely. However, a general conventional image forming apparatus transports a sheet (for example, printing paper) on which an image is formed in a horizontal direction with respect to the installation surface to form an image. Therefore, at least the maximum usable sheet area is obtained. A correspondingly large installation area is required. Therefore, conventionally, there has been an image forming apparatus such as a copying machine or a printer (hereinafter referred to as “vertical image forming apparatus”) in which a sheet on which an image is formed is conveyed while standing upright in a substantially vertical direction with respect to the installation surface. It has been proposed (see, for example, Patent Document 1 and Patent Document 2).

JP-A-6-202390 JP-A-7-137379

  However, such a vertical image forming apparatus holds the discharged sheets in an upright state in a substantially vertical direction with respect to the installation surface, so that it is difficult to stack the discharged sheets one after another. Sheet jamming is also likely to occur. Also, if the sheets are discharged one after another onto the device installation surface (for example, on a desk) without being held in an upright state, there are many factors such as variations in the angle when the sheets are discharged and bending (buckling) of the sheets. The positions of the discharged sheets on the installation surface are indefinite and cannot be stacked in an orderly manner.

  Accordingly, an object of the present invention is to provide a vertical image forming apparatus that can stack discharged sheets in an orderly manner and that does not cause jamming of sheets.

A first aspect of the present invention is a vertical image forming apparatus that discharges the medium in a substantially upright state in which a predetermined sheet-shaped medium surface on which an image is formed is in a state along a substantially vertical direction,
Image forming means for forming an image on a predetermined surface of the medium;
Discharging means for discharging the medium in a substantially upright state;
Angle changing means for changing the angle of the medium discharged in a substantially upright state by the discharging means with respect to a horizontal plane ;
The angle changing means, the medium was supported at a substantially upright position until after being discharged by said discharging means so as not buckle, characterized that you change its angle to the horizontal plane of the medium.

According to a second invention, in the first invention,
The angle changing means includes guide means for supporting the medium in a substantially upright state so that the medium does not buckle when the medium is discharged at least by the discharging means.

According to a third invention, in the second invention,
The guide means supports the medium in a substantially upright state by detachably bonding the medium when the medium is discharged at least by the discharge means, and when the angle of the medium with respect to the horizontal plane is changed The adhesive state with the medium is released.

According to a fourth invention, in the third invention,
The guiding means includes
When the medium is being discharged by the discharging means, a belt that conveys the medium in a direction in which the medium should be discharged while adhering the medium;
The belt is stretched over, and includes a roller for driving the belt,
When the angle of the medium with respect to the horizontal plane is changed, the belt is released from the adhesive state with the medium.

According to a fifth invention, in the first invention,
The guide means includes a lower guide rail that supports the medium in a substantially upright state by supporting the lower end portion of the medium so that the medium does not buckle when the medium is discharged at least by the discharge means. It is characterized by.

According to a sixth invention, in the fifth invention,
The guide means further includes an upper guide rail that supports the upper end portion of the medium so as to prevent the medium from buckling so that the medium does not buckle.

A seventh invention is the fifth or sixth invention, wherein
The guide means is characterized by being curved along a substantially horizontal plane.

In an eighth aspect based on the first aspect ,
The guide means releases the support of the medium when an angle of the medium with respect to a horizontal plane is changed.

In a ninth aspect based on the eighth aspect ,
The guide means includes a lower guide rail that supports the medium in a substantially upright state so that the medium does not buckle by supporting the lower end portion of the medium when the medium is discharged at least by the discharge means.
The lower guide rail is configured to release the support of the medium by rotating a predetermined angle when the angle of the medium with respect to a horizontal plane is changed.

In a tenth aspect based on the first aspect,
When the medium is paper, it is further characterized by further comprising moisture reducing means for removing or reducing moisture contained in the medium.

According to the first aspect of the invention, the medium discharged in the substantially upright state is stacked in an orderly manner by changing the angle of the medium discharged in the substantially upright state by the discharge means with the angle changing means. In addition, it is possible to provide a vertical type image forming apparatus that does not cause jamming of media. Further, the angle changing means supports the medium in an upright state until the discharge is completed so that the medium does not buckle, and then changes the angle of the medium with respect to the horizontal plane, so that the medium to be discharged is placed in an almost identical position. be able to.

According to the second aspect of the invention, since the medium is supported by the guide means so as not to buckle when the medium is discharged at least by the discharge means, the medium is stacked in order without being buckled during discharge. And jamming of the medium can be prevented.

According to the third aspect of the invention, the medium is detachably bonded by the guide means so that the medium is supported in an upright state. When the angle of the medium with respect to the horizontal plane is changed, the bonded state with the medium is released. Even when the paper is weak, it is possible to completely prevent the sheet from being stuck due to buckling, and it is possible to prevent the medium from being jammed and stack the medium reliably in order.

According to the fourth aspect of the invention, when the angle of the belt that conveys the medium in the direction in which the medium is to be discharged while the medium is adhered is changed with respect to the horizontal plane of the medium, the adhesion state with the medium is released, for example, Even when the paper is weak, it is possible to completely prevent the stack from becoming impossible due to buckling, and the medium can be prevented from clogging and the media can be reliably stacked in order.

According to the fifth invention, the lower guide rail that supports the lower end portion of the medium so as to prevent the medium from buckling so that the medium does not buckle. Thus, stacking can be done in order, and jamming of the medium can be prevented.

According to the sixth invention, the upper guide rail that supports the upper end of the medium so as to prevent the medium from buckling is further provided, so that the medium can be more reliably discharged with a simple configuration. The media can be stacked in order without buckling the media, and jamming of the media can be prevented.

According to the seventh aspect of the present invention, the guide means that is curved substantially along the horizontal plane can reliably prevent the stack from becoming impossible due to buckling, for example, even when the medium is a low-waist sheet. It is possible to prevent clogging of the media and to reliably stack the media in order.

According to the eighth aspect of the invention, when the angle of the medium with respect to the horizontal plane is changed by the guide means, the support of the medium is released, so that the angle of the medium can be easily changed without buckling the medium during discharging. Therefore, the media can be stacked in an orderly manner, and jamming (jamming) of the media can be prevented.

According to the ninth aspect , when the medium is discharged, the lower end of the medium is supported so that the medium does not buckle so that the medium does not buckle. The lower guide rail that releases the support of the medium by rotating the angle can easily change the angle without buckling the medium at the time of ejection with a simple configuration, so that the medium can be stacked in order. And jamming of the medium can be prevented.

According to the tenth invention, the moisture contained in the medium, which is paper, is removed or reduced by the moisture reducing means for removing or reducing the moisture contained in the medium, thereby increasing the strength of the medium. Therefore, large bending (buckling) due to the weight of the medium can be prevented in advance.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<1. First Embodiment>
<1.1 Configuration and Operation of Entire Image Forming Apparatus>
FIG. 1 is a perspective view showing an appearance of a vertical image forming apparatus according to the first embodiment of the present invention, FIG. 2 is a plan view showing the structure of the image forming apparatus, and FIG. It is a side view which shows the structure of an image forming apparatus simply. In FIG. 1, these are shown by dotted lines in order to show the positional relationship between the paper transport path and the predetermined rollers, and in FIG. 3, they are shown by dotted lines in order to show the positional relationship between the predetermined rollers. Has been. The coordinate axes in the figure are set so that the width direction (horizontal direction) of the vertical image forming apparatus is the X axis, the depth direction is the Y axis, and the height direction (vertical direction) is the Z axis.

  As shown in FIG. 2, the image forming apparatus includes a photosensitive drum 17 that rotates in the direction of an arrow in the form of a drum as a mechanism for image formation, and develops around the photosensitive drum 17 along the direction of the arrow. A roller 18, a transfer roller 19, a cleaning device 20, a static eliminator (not shown), a main charging roller 21, and a laser scanning unit (hereinafter abbreviated as “LSU”) 22 are provided.

  Image data given from a computer (not shown) outside the apparatus is supplied to the LSU 22 after being subjected to predetermined image processing. The LSU 22 irradiates the surface of the photosensitive drum 17 with the image data as laser light to form an electrostatic latent image. The developing roller 18 develops the electrostatic latent image into a visible image with toner. The transfer roller 19 transfers the toner image formed on the surface of the photosensitive drum 17 by development to the paper P. The cleaning device 20 removes residual toner on the surface of the photosensitive drum 17. The static eliminator removes residual charges on the surface of the photosensitive drum 17. The main charging roller 21 charges the photosensitive drum 17 to a predetermined potential.

  In addition, the image forming apparatus includes a paper cassette 31 that stores a plurality of paper P, a drawing roller 32, and a paper separating roller 33 as a paper feeding mechanism that supplies the paper P to the image forming mechanism. The paper cassette 31 has a structure that can be taken out of the apparatus from a paper cassette outlet 30 provided in the front of the apparatus. After the paper P is built outside the apparatus, the paper cassette 31 enters the apparatus from the paper cassette outlet 30. Set. The paper cassette 31 holds the paper P supplied from the paper cassette outlet 30 so as to be aligned in the paper output direction and upright in a substantially vertical direction (vertical direction) by two pressing plates (not shown). Note that one or more of these pressing plates are biased by a biasing means such as a spring so that the upright state of the paper P is maintained even when the paper P is reduced. The incoming roller 32 and the paper separating roller 33 are provided at the leading end position of the paper cassette 31 in the paper output direction, and output the paper P. The paper separating roller 33 includes a roller that rotates in one direction and a roller that rotates in the reverse direction, and prevents double feeding of the paper P. In addition, it may replace with this structure and the well-known structure which consists of a roller and a friction sheet member may be sufficient.

  As a paper transport path, a cassette-side paper output path 34 is provided in the paper feed mechanism. Here, the side on which the paper P flows out (from the paper cassette 31) in the paper transport path is called the upstream side, and the side on which the paper P flows (to the guide rail 100 for paper discharge) is called the downstream side. A sheet separation roller 33 is provided at the upstream end of the cassette-side paper exit path 34, and a registration roller 43 is provided at the downstream end. In addition, a conveyance guide 35 for changing the conveyance direction of the paper P is provided in the middle of the cassette-side output path 34.

  Further, a main transport path 36 is provided in the image forming mechanism as a paper transport path. A registration roller 43 is provided at the upstream end of the main conveyance path 36, and a pre-registration detection switch (not shown) for detecting the passage of the paper is provided at a predetermined position upstream of the registration roller 43. Yes. In this image forming apparatus, the registration roller 43 aligns the toner image on the photosensitive drum 17 and the paper P based on the detection signal indicating that the pre-registration detection switch has detected the passage of the paper. Yes.

  At a predetermined position downstream of the transfer roller 19 in the main conveyance path 36, a fixing roller 44 is provided that is composed of a pair of rollers that heat and press the toner image on the paper P. The paper P is nipped and conveyed by the fixing roller 44 and is carried out from a paper discharge port 50 opened in the front of the apparatus to a guide rail 100 exposed to the outside of the apparatus.

  Here, the fixing roller 44 also has a function of removing or reducing moisture contained in the paper P by heating the paper P. With this function, the strength of the paper P can be increased, so that a large bending due to the weight of the paper P can be prevented in advance. In an image forming apparatus including an image forming mechanism that can fix an image without heating the paper P, a heater or a dehumidifying device for removing or reducing moisture contained in the paper P may be provided. In the present image forming apparatus, these may be provided together with the fixing roller 44.

  Further, various rollers such as the photosensitive drum 17 and the developing roller 18 are driven by a driving member (not shown) including a driving motor, a gear, and a belt that are provided in correspondence with each other, and a control device (not shown) that controls them. These are appropriately arranged at predetermined positions such as near the upper surface or near the lower surface inside the apparatus. Since these structures are well-known, detailed description is abbreviate | omitted.

  As shown in FIG. 3, the guide rail 100 includes an upper guide rail 100a and a lower guide rail 100b that are arranged in parallel at a predetermined interval in the vertical direction, and the lower guide rail 100b is a guide rail. The rail drive unit 110 is rotated in a predetermined direction. The guide rail drive unit 110 includes an electric motor including a reduction gear, and an arm and a rotating shaft, which will be described later, connected to the lower guide rail 100b. Hereinafter, the configuration and operation of the guide rail 100 and the guide rail driving unit 110 will be described in detail.

<1.2 Guide rail configuration and operation>
FIG. 4 is a front view showing the image forming apparatus when the paper P is discharged. 4 and 3, the upper guide rail 100a and the lower guide rail 100b are arranged in the depth direction (plus direction in the Y axis) with a predetermined interval in the vertical direction (plus direction in the Z axis). The predetermined interval is substantially equal to the length of the sheet P in the vertical direction (hereinafter referred to as “sheet width”). The lengths of the upper guide rail 100a and the lower guide rail 100b in the depth direction are substantially equal to the length of the paper P in the paper ejection direction (depth direction) (hereinafter referred to as “paper length”). The lengths of the upper guide rail 100a and the lower guide rail 100b in the depth direction may be longer than the paper length, or may be short enough to hold the paper so that it does not bend greatly due to its own weight. The upper guide rail 100a and the lower guide rail 100b are arranged so that the recesses face each other, and the cross-sectional shape seen from the front is a U-shape shown in FIG. Sides along the Y-axis direction of the paper P are supported by the upper guide rail 100a and the lower guide rail 100b as described above, and the paper P is bent largely by its own weight (also referred to as “buckling”) in the Z-axis direction. Are held in a substantially upright state (hereinafter referred to as “upright state”).

  When it is detected that the paper P has been completely discharged between the upper guide rail 100a and the lower guide rail 100b, the guide rail driving unit 110 performs a predetermined angle changing operation on the paper P. A paper discharge detection switch (not shown) for detecting the passage of paper is provided at a predetermined position downstream of the fixing roller 44 (that is, in the vicinity of the paper discharge port 50). Based on the detection of the passage of the paper by the paper discharge detection switch (a detection signal indicating this) and a predetermined elapsed time counted by a predetermined timer, it is detected that the paper P has been discharged. Hereinafter, the angle changing operation of the guide rail driving unit 110 will be described.

  FIG. 5 is a front view showing the image forming apparatus after the angle changing operation by the guide rail driving unit. As shown in FIG. 5, the lower guide rail 100b rotates 90 degrees counterclockwise from the position shown in FIG. 4 (this operation is hereinafter referred to as “rotation operation”) and moves to the left by a predetermined distance. (This operation is hereinafter referred to as “movement operation”). In this specification, the left direction means the minus direction on the X axis, and the right direction means the plus direction on the X axis. As the lower guide rail 100b rotates and moves in this manner, the sheet P held upright between the upper guide rail 100a and the lower guide rail 100b has its lower end portion leftward. While moving, the right side surface of the paper P is pushed by the lower guide rail 100b. As a result, the sheet P is released from the holding state by the upper guide rail 100a and the lower guide rail 100b, slips to the left side of the image forming apparatus while being bent slightly by its own weight, and is horizontally placed on the sheet bundle Pk. The By repeating such an angle changing operation, the sheet bundle Pk is stacked in the vertical direction (plus direction in the Z axis). The angle changing operation includes the rotation operation and the movement operation as described above for changing the sheet P from the upright state to the horizontally loaded state. Depending on the position, only the rotation operation or only the movement operation may be performed. Further, the rotation direction and the movement direction may be reversed.

  FIG. 6 is a front view showing a part of the image forming apparatus for explaining the angle changing operation by the guide rail driving unit. As shown in FIG. 6, the lower guide rail 100b includes a rectangular bottom surface portion 101b having a long side along the Z-axis, a right surface portion 102b, and a left surface portion 103b. It has a shape. Further, one end of the arm 111 is fixed at a predetermined angle to an end portion of the lower guide rail 100b near the paper discharge port 50, and the other end of the arm 111 is fixed to the rotating shaft 112. The rotating shaft 112 is rotated by a driving operation of an electric motor (a reduction gear thereof) included in the guide rail driving unit 110. This will be specifically described below.

  As shown in FIG. 6, the lower guide rail before the detection of the discharge of the paper P between the upper guide rail 100a and the lower guide rail 100b, that is, before the angle changing operation, The lower guide rail 100b ′ is indicated by a dotted line, and the arm at that time is also indicated by a dotted line as the arm 111 ′. Here, when the angle changing operation is started, the rotating shaft 112 provided along the Y-axis rotates counterclockwise by a predetermined angle θ (here, 90 degrees) when viewed from the front. The angle θ is not necessarily 90 degrees, and the angle is not limited as long as the sheet P rotates so as to slide down to the side of the apparatus, and may be, for example, 360 degrees. By the rotation of the rotating shaft 112, the lower guide rail 100b gently moves the lower end portion of the paper P within a space (hereinafter referred to as “holding space”) surrounded by the bottom surface portion 101b, the right surface portion 102b, and the left surface portion 103b. While holding and moving the lower end portion to the left, the right surface portion 102b pushes the right surface of the paper P to the left. When the rotation shaft 112 rotates by an angle θ, the lower guide rail 100b and the arm 111 move to the positions shown in FIG. By this time, the lower end portion of the sheet P has moved leftward from the holding space, and the right side surface of the sheet P is in contact with the upper end portion of the right surface portion 102b of the lower guide rail 100b. P is released from the holding state and slightly bent by its own weight, sliding down to the left while sliding on the upper end of the right surface portion 102b, and placed horizontally on the sheet bundle Pk. This operation is repeated as exactly the same operation after the paper P is discharged and once held by the guide rail 100. Therefore, as long as attributes such as the size, weight, and material of the paper P are substantially the same, The discharged paper P slides down to almost the same position, and as a result, it is placed neatly on the paper bundle Pk.

  As described above, the sheet bundle Pk is placed on the installation surface (for example, on a desk) of the apparatus, but a paper discharge tray or the like may be provided on the apparatus installation surface and placed thereon. In addition, the sheet bundle Pk does not necessarily have to be placed horizontally, and a sheet having a predetermined angle with respect to the horizontal plane (for example, a sheet having the predetermined angle with respect to the horizontal plane) to the extent that the sheets P can be stacked. It may be placed on a tray or the like.

  In this way, the lower guide rail 100b and the guide rail driving unit 110 functioning as an angle changing unit allow the discharged paper P to be placed horizontally from a state in which the discharged paper P stands substantially vertically with respect to the installation surface. Can be changed.

<1.3 Effects of First Embodiment>
As described above, the image forming apparatus once supports the paper P discharged by the guide rail 100 in an upright state in a substantially vertical direction with respect to the installation surface, and then the lower guide rail 100b and the guide rail driving unit 110. By changing the angle, the angle is changed so as to be placed horizontally. Since this operation is repeated every time one sheet P is discharged, the jamming of the sheet P does not occur in the guide rail 100, and this operation is once held after the sheet P is discharged. Since it is repeated as the same operation every time later, the sheets P to be discharged one after another can be easily and orderly stacked.

<2. Second Embodiment>
<2.1 Overall Configuration of Image Forming Apparatus>
FIG. 7 is a perspective view showing an appearance of a vertical image forming apparatus according to the second embodiment of the present invention. In the drawing, in order to show the positional relationship between the paper conveyance path and several rollers, they are indicated by dotted lines, and the coordinate axes in the drawing are the same as those in the first embodiment. As shown in FIG. 7, the present embodiment differs from the vertical image forming apparatus according to the first embodiment shown in FIG. 1 only in the shape of the guide rail, and other components of the image forming apparatus. Since this is the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

<2.2 Guide rail configuration and operation>
As shown in FIG. 7, the upper guide rail 200a and the lower guide rail 200b in the present embodiment are arranged in the vertical direction (the same as the upper guide rail 100a and the lower guide rail 100b in the first embodiment shown in FIG. The first embodiment is arranged in parallel with a predetermined interval in the direction along the Z-axis), but is curved so as to be convex on the right side of the apparatus (concave on the left side). Is different. The flexible paper P is discharged in a curved state along the upper guide rail 200a and the lower guide rail 200b.

  The curved paper P can be maintained in an upright state more easily than the non-curved paper P in the first embodiment. For example, paper that is easily bent (also called “paper with low stiffness”), such as when it is thin or soft, is prone to large bending (buckling) due to its own weight, making it difficult to maintain an upright state. There may be. However, by bending the paper P along the horizontal plane (in the X-axis direction), it is possible to make it difficult for buckling paper to be buckled.

  The degree of curvature (curvature) of the upper guide rail 200a and the lower guide rail 200b may not be uniform. For example, the upper guide rail 200a and the lower guide rail 200b may be linearly bent at one or more places, or may be S-shaped with respect to a horizontal plane. Further, as long as the paper P can be discharged without difficulty, there is no limitation on the degree of bending of the upper guide rail 200a and the lower guide rail 200b.

  Here, when it is detected that the paper P is discharged between the upper guide rail 200a and the lower guide rail 200b, the guide rail driving unit 110 performs a predetermined process on the paper P as in the case of the first embodiment. The angle change operation is performed. The length direction of the rotating shaft 112 included in the guide rail driving unit 110 may be the depth direction (the direction along the Y axis) as in the first embodiment, but here the lower side It is assumed that the direction is along a straight line connecting one end of the guide rail 200b on the paper discharge port 50 side and the vicinity of the other end on the opposite side. By doing so, the other end of the lower guide rail 200b does not hit the installation surface of the apparatus.

  When the angle changing operation is started, the rotating shaft 112 rotates counterclockwise by a predetermined angle θ (for example, 90 degrees). By the rotation of the rotating shaft 112, the lower guide rail 200b gently holds the lower end portion of the sheet P in the holding space and moves the lower end portion to the left while moving the right side surface of the sheet P to the left. Push. Thereafter, when the rotation shaft 112 is rotated by an angle θ, the lower end portion of the paper P is disengaged leftward from the holding space, and the right surface of the paper P is at the upper end portion near the center of the lower guide rail 100b. Since the sheet P is brought into contact with the sheet, the sheet P is released from the holding state, slightly bent by its own weight, slides down to the left side while sliding on the upper end, and is placed horizontally on the installation surface.

  In this way, the sheet P curved along the upper guide rail 200a and the lower guide rail 200b is placed in a substantially vertical direction with respect to the installation surface by the lower guide rail 200b and the guide rail driving unit 110 that function as angle changing means. The angle can be changed so as to be placed horizontally from an upright state.

<2.3 Effects of Second Embodiment>
As described above, in this image forming apparatus, similarly to the first embodiment, the paper P is not jammed (jammed) in the guide rail, and the paper P discharged one after another is easily and orderly. Can be stacked. Further, unlike the first embodiment, the paper P is curved along the upper guide rail 200a and the lower guide rail 200b, thereby preventing the paper from being stuck due to buckling even if the paper is weak. Therefore, the sheets P can be reliably stacked in order.

<3. Third Embodiment>
<3.1 Overall Configuration of Image Forming Apparatus>
FIG. 8 is a plan view showing the structure of a vertical image forming apparatus according to the third embodiment of the present invention, and FIG. 9 is a front view showing the image forming apparatus when the paper P is discharged. is there. The coordinate axes in the figure are the same as those in the first embodiment. As shown in FIG. 8, in place of the guide rail 100 and the guide rail driving unit 110 provided in the vertical image forming apparatus according to the first embodiment shown in FIG. The other components of the image forming apparatus are the same as those in the first embodiment except that the electrostatic chuck 300 is provided. Therefore, the same components are denoted by the same reference numerals and the description thereof is omitted. Hereinafter, the configuration and operation of the electrostatic attraction unit 300 will be described.

<3.2 Configuration and operation of electrostatic chuck>
The electrostatic adsorption unit 300 is configured to remove an electrostatic adsorption belt 305 that can adsorb the paper P by static electricity and a surface of the electrostatic adsorption belt 305 that adsorbs the paper P on the electrostatic adsorption belt 305. Rollers 306 and 307 driven in the paper direction, and a belt drive unit 310 that applies static electricity to the electrostatic adsorption belt 305 and applies rotational force to the rollers 306 and 307 are provided.

  The belt drive unit 310 includes an electric motor and a gear for applying a rotational force to the rollers 306 and 307, and an electrostatic adsorption (not shown) on a surface facing the electrostatic adsorption belt 305 for applying static electricity to the electrostatic adsorption belt 305. Includes a board. The electrostatic attraction plate includes an insulating layer, and a plurality of electrodes are provided inside the insulating layer at a predetermined interval. When a high voltage is applied to these electrodes so as to alternate between positive and negative, positive and negative charges are generated in the electrostatic adsorption belt 305 and the paper P, and the electrostatic adsorption belt 305 adsorbs the paper P. In addition, the said structure is an illustration, Comprising: The belt drive part 310 should just have the well-known structure which gives static electricity to the electrostatic adsorption belt 305. FIG.

  Here, when it is detected by the detection signal from the paper discharge detection switch that the paper P has started to be discharged from the image forming apparatus of the present embodiment, the belt driving unit 310 electrostatically attracts the paper P. Static electricity is applied to the suction belt 305 and the surface of the electrostatic suction belt 305 that has attracted the paper P by driving the rollers 306 and 307 is discharged at a speed substantially equal to (or slightly faster than) the discharge speed of the apparatus. Move in the direction. Here, the static electricity is given with such a strength that the paper P does not slide down due to its own weight. With this configuration, the paper P is guided in a substantially upright state so as not to buckle.

  Thereafter, when it is detected that the paper P has been discharged from the image forming apparatus based on the detection signal from the paper discharge detection switch and the elapsed time counted by the timer, the belt driving unit 310 drives the rollers 306 and 307. While stopping, a predetermined angle changing operation for the paper P is performed as in the first embodiment. This angle changing operation is performed by stopping the operation of applying static electricity to the electrostatic attraction belt 305 by the belt driving unit 310. As shown in FIG. 9, the electrostatic attraction unit 300 is installed in an inclined state with respect to the image forming apparatus so as to have a predetermined angle with respect to the horizontal plane with the paper P facing upward. Therefore, when the operation of applying static electricity to the electrostatic attraction belt 305 is stopped, the paper P is released from the state of being supported in a substantially upright state, and slides down to the left while sliding on the electrostatic attraction belt 305, and the apparatus installation surface Placed horizontally on top. Note that the electrostatic adsorption unit 300 may be installed in a tilted state with the paper P facing down, or may be installed vertically. Here, since the paper P is discharged in a state of being upright in the vertical direction, if the electrostatic attraction unit 300 is installed in a state of being largely inclined (for example, substantially horizontal) with respect to the image forming apparatus, the positional deviation of the paper or Prone to jamming. Therefore, it is preferable that the electrostatic attraction unit 300 be installed upright so as to have an angle of 45 degrees or more with respect to the horizontal plane (this state is substantially upright).

  As described above, the operation of the electrostatic attraction unit 300 functioning as the angle changing unit causes the paper P discharged along the electrostatic attraction belt 305 of the electrostatic attraction unit 300 to be in a substantially vertical direction or a predetermined direction with respect to the installation surface. The angle can be changed so as to be placed horizontally from a substantially upright state that is substantially upright at the angle.

<3.3 Effects of Third Embodiment>
As described above, in the image forming apparatus, the sheet P is attracted by the electrostatic attraction belt 305 of the electrostatic attraction unit 300 and is discharged in the sheet discharge direction at a speed substantially equal to (or slightly faster than) the sheet discharge speed of the apparatus. Since the paper P is moved, jamming of the paper P does not occur, and the paper P to be discharged one after another can be easily and orderly stacked. Furthermore, since the paper P is attracted to the electrostatic adsorption belt 305, it is possible to completely prevent the paper P from being stuck due to buckling, so that the paper P is reliably stacked in order. be able to.

<4. Modification>
In the first to third embodiments, the paper P is paper, but it may be a medium on which images made of various materials are formed. The image forming apparatus is a laser printer and employs an electrophotographic system using laser light. However, the image forming apparatus may be another apparatus as long as it is an image forming apparatus such as a copying machine or a FAX apparatus. In addition, a known image forming method such as a thermal transfer method or an ink jet method may be used. Further, the image forming apparatus may be an apparatus that forms an image on both sides of a sheet, such as a double-sided printer.

  In the first and second embodiments, the paper P to be discharged is guided by the upper guide rail 100a and the lower guide rail 100b, but can be supported in a substantially upright state so that the paper P does not buckle. In this case, the upper guide rail 100a may be omitted. Further, the guide rail is not limited to the guide rail as long as the sheet P is guided in a substantially upright state so as not to buckle, and a plate-shaped guide plate provided so as to be in contact with one or both surfaces of the sheet P. Or a bar-shaped guide bar.

  In the first and second embodiments, the sheet P is placed horizontally from a state in which the sheet P is vertically upright with respect to the installation surface by the angle changing operation of the lower guide rails 100b and 200b and the guide rail driving unit 110. The angle is changed so that various mechanisms can be considered for the mechanism for changing the angle.

  For example, the lower guide rails 100b and 200b are provided in parallel with each other at positions slightly shifted to the left from the corresponding lower guide rails 100a and 200a (in the vertical direction), and the discharged paper P is in the vertical direction. It may be held in a slightly tilted state. After that, when the paper P is completely discharged, the guide rail driving unit 110, specifically, the left surface portion thereof becomes substantially flush with the lower surface portion so as to open the holding space of the lower guide rails 100b and 200b. You may make it rotate like this. Then, the paper P slides down to the left and is placed horizontally on the installation surface.

  Further, for example, instead of the guide rail driving unit 110, a bar-shaped member that pushes the paper P in the horizontal direction so as to be detached from the guide rail and a driving unit that drives the bar-shaped member are provided, and the paper P is completely discharged. Then, an angle changing operation in which the bar-like member driven by the driving unit pushes the paper P in the horizontal direction may be performed. As a result, the paper P comes off the guide rail and slides down, so that the paper P is placed horizontally from a state in which it stands upright in a substantially vertical direction with respect to the installation surface.

  Further, for example, instead of the guide rail driving unit 110, the sheet P is attracted in a horizontal direction to a position separated by a predetermined distance so as to be separated from the guide rail (as shown in the third embodiment). And a static electricity generating unit that applies static electricity to the electrostatic chucking plate. When the paper P is completely discharged, the electrostatic chucking plate applied with static electricity by the static electricity generating unit causes the paper P to move horizontally. An operation of stopping the application of static electricity by the static electricity generation unit after the adsorption, that is, an angle changing operation may be performed. As a result, the paper P comes off the guide rail and slides down, so that the paper P is placed horizontally from a state in which it stands upright in a substantially vertical direction with respect to the installation surface.

  As described above, as long as the angle can be changed so that the sheet P is placed horizontally from a state in which the sheet P stands upright in a substantially vertical direction, the mechanism for changing the angle is particularly limited. There is no.

  In the third embodiment, the sheet P is moved while being electrostatically attracted by the electrostatic adsorption unit 300. When the sheet P is discharged, the sheet P is supported in a substantially upright state by being detachably bonded. However, the configuration is not limited as long as the bonding state can be canceled when the angle of the paper P is changed. For example, the paper P may be moved in a state where it is adsorbed (typically vacuum adsorbed) by a change in air pressure, or may be moved in a state where it is adhered by a magnetic force or a chemical bonding force (for example, adhesive force). However, it may be moved in a state of being bonded by a physical force by a method of sandwiching with a locking member such as a clip.

1 is a perspective view illustrating an appearance of a vertical image forming apparatus according to a first embodiment of the present invention. It is a top view which shows the structure of the image forming apparatus which concerns on the said embodiment. It is a side view which shows simply the structure of the image forming apparatus which concerns on the said embodiment. FIG. 2 is a front view illustrating the image forming apparatus when a sheet is discharged in the embodiment. It is a front view which shows the image forming apparatus after the angle change operation | movement by the guide rail drive part in the said embodiment. It is a front view which shows a part of image forming apparatus for demonstrating the angle change operation | movement by the guide rail drive part in the said embodiment. It is a perspective view which shows the external appearance of the vertical image forming apparatus which concerns on the 2nd Embodiment of this invention. It is a top view which shows the structure of the vertical type image forming apparatus which concerns on the 3rd Embodiment of this invention. FIG. 2 is a front view illustrating the image forming apparatus when a sheet is discharged in the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 17 ... Photosensitive drum 18 ... Developing roller 19 ... Transfer roller 20 ... Cleaning device 21 ... Main charging roller 30 ... Paper input port 31 ... Paper cassette 32 ... Inlet roller 33 ... Paper separation roller 34 ... Cassette side paper discharge path 35 ... Conveyance guide 36: Main transport path 43 ... Registration roller 44 ... Fixing roller 50 ... Discharge port 100a, 200a ... Upper guide rail 100b, 200b ... Lower guide rail 110 ... Guide rail drive unit 300 ... Electrostatic adsorption unit 305 ... Electrostatic adsorption Belt 310 ... Belt drive P ... Paper

Claims (10)

A vertical image forming apparatus that discharges the medium in a substantially upright state in which a sheet-like medium predetermined surface on which an image is formed is in a state along a substantially vertical direction,
Image forming means for forming an image on a predetermined surface of the medium;
Discharging means for discharging the medium in a substantially upright state;
Angle changing means for changing the angle of the medium discharged in a substantially upright state by the discharging means with respect to a horizontal plane ;
The angle changing means, after supporting a substantially upright position until after being discharged by said discharge means so that the medium does not buckle, the image forming apparatus characterized that you change the angle with respect to a horizontal plane of the medium. The angle changing means, when the medium is discharged by at least said discharge means, characterized in that it comprises a guiding means for the medium is supported in a substantially upright position so as not buckle, according to claim 1 Image forming apparatus. The guide means supports the medium in a substantially upright state by detachably bonding the medium when the medium is discharged at least by the discharge means, and when the angle of the medium with respect to the horizontal plane is changed The image forming apparatus according to claim 2 , wherein the adhesive state with the medium is released. The guiding means includes
When the medium is being discharged by the discharging means, a belt that conveys the medium in a direction in which the medium should be discharged while adhering the medium;
The belt is stretched over, and includes a roller for driving the belt,
The image forming apparatus according to claim 3 , wherein when the angle of the medium with respect to a horizontal plane is changed, the belt is released from the adhesive state with the medium. The guide means includes a lower guide rail that supports the medium in a substantially upright state by supporting the lower end portion of the medium so that the medium does not buckle when the medium is discharged at least by the discharge means. The image forming apparatus according to claim 1 , wherein: The image forming apparatus according to claim 5 , wherein the guide unit further includes an upper guide rail that supports the upper end portion of the medium so that the medium does not buckle so that the medium does not buckle. . The image forming apparatus according to claim 5 , wherein the guide unit is curved along a substantially horizontal plane. The image forming apparatus according to claim 1 , wherein the guide unit releases support of the medium when an angle of the medium with respect to a horizontal plane is changed. The guide means includes a lower guide rail that supports the medium in a substantially upright state so that the medium does not buckle by supporting the lower end of the medium when the medium is discharged at least by the discharge means.
The image forming apparatus according to claim 8 , wherein the lower guide rail releases the support of the medium by rotating a predetermined angle when the angle of the medium with respect to a horizontal plane is changed.   The image forming apparatus according to claim 1, further comprising a moisture reducing unit that removes or reduces moisture contained in the medium when the medium is paper.

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