JP5742010B2 - Sheet placing apparatus, image forming apparatus, and image reading apparatus - Google Patents

Description

  The present invention relates to a sheet placing apparatus including a sheet positioning unit that aligns a sheet member placed on a placement surface at a predetermined position, and an image forming apparatus and an image reading apparatus including the sheet placing apparatus. is there.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine or a printer, an image reading apparatus such as a scanner, an automatic document feeder (hereinafter referred to as ADF), or the like, which uses a sheet-like sheet member, is provided with a sheet positioning unit equipped with a sheet alignment means. A device equipped with a device is known. In this type of sheet placing apparatus, a sheet aligning unit allows a sheet member such as a recording sheet or an OHP film or a sheet member such as an original sheet to be placed in a predetermined conveyance orthogonal direction perpendicular to the sheet conveyance direction on the placement surface. Can be aligned to the position. As an image forming apparatus, a sheet placement apparatus such as a paper feed cassette or a manual paper feed tray that employs such a configuration is known. Further, as scanners and ADFs, there are known ones that employ such a configuration for a sheet placement device such as a document placement table on which a document sheet is placed.

  In a conventional sheet placement device, the sheet member is generally aligned by restricting the position of the sheet member placed on the placement surface with a restriction member. For example, the image forming apparatus described in Patent Document 1 includes a sheet aligning device as a sheet placing device including a sheet positioning unit. The sheet aligning apparatus has two side fences arranged as a regulating member so as to slide in the conveyance orthogonal direction on the placement surface. Each of these two side fences has a home position at a position largely separated from each other. When a recording sheet as a sheet member is set on the placement surface of the sheet placement device, first, the two side fences are respectively moved to the home position by the drive motor. In this state, when a bundle of a plurality of recording sheets is set on the placement surface, the drive motor is rotationally driven in the opposite direction, and the two side fences start to move toward each other. Then, the sheet comes into contact with a recording sheet at a position shifted to the end side in the conveyance orthogonal direction in the sheet bundle, and the recording sheet is pushed toward the center. In this way, while pressing the recording sheet at the position where the two side fences are offset from each other toward the center of the sheet placement surface, the distance between them becomes closer to the same value as the width dimension of the recording sheet. A plurality of recording sheets placed on the sheet placement surface can be aligned with the center of the sheet placement surface.

  However, in this sheet aligning apparatus, it is necessary to provide a size detecting means for detecting the size of the recording sheet. Specifically, the sheet aligning apparatus conveys a recording sheet to be aligned by a conveying unit with respect to a placement surface on which the recording sheet is aligned. Then, in the process until the recording sheet is conveyed to the placement surface, the size of the recording sheet is detected by the size detecting means. When the recording sheet is conveyed to the placement surface, the two side fences positioned at the home position are moved toward the center of the placement surface by driving the motor for a time corresponding to the size of the recording sheet. Accordingly, the recording sheets placed between the fences are aligned with the center of the placement surface by bringing the two side fences closer to the same distance as the size of the recording sheet. In such a configuration, it is impossible to know how long the side fence should be driven unless the size of the recording sheet is detected in advance by the size detecting means. For this reason, it is necessary to provide a size detecting means, which causes a reduction in the degree of freedom in layout.

  Therefore, the present inventors are developing the following new sheet placing apparatus. That is, when a load exceeding a predetermined threshold occurs in the drive system from the drive motor to the side fence, or when a pressure exceeding the predetermined threshold is applied to the side fence, the movement of the side fence is automatically performed. It is a sheet alignment apparatus provided with a movement stop means for stopping. Examples of the movement stop means include a torque limiter that cuts off the transmission of the drive by the clutch when the torque applied to the clutch in the drive transmission system exceeds a predetermined threshold. Further, the drive motor may be stopped when the detection result by the pressure sensor that detects the pressure applied to the side fence exceeds a predetermined threshold value. When the two moving side fences approach each other to the same size as the size of the recording sheet, the recording sheet strikes between them, so the torque applied to the torque limiter and the pressure applied to the side fences have thresholds. Exceed. At this time, by stopping the movement of the two side fences, the side fences can be stopped at an appropriate position even if the size of the recording sheet is not known in advance. In such a configuration, it is possible to automatically stop the two side fences at positions corresponding to the dimensions of the recording sheet without knowing the size of the recording sheet in advance, so that the size detecting means can be omitted. .

  However, in this sheet placing apparatus, there is a possibility that the recording sheet may be severely wrinkled or torn. Specifically, if the recording sheet is slightly warped, the recording sheet sandwiched between the two side fences may gradually bend instead of pushing back the side fence with sufficient force. Then, as shown in FIG. 1, the movement of the side fence is continued until the recording sheet 6 is largely bent and the side fences (611, 612) are pushed back with a sufficient force. When the recording sheet 6 in such a greatly bent state is sent out from the placement surface, the recording sheet 6 may be caught on a guide member or the like, and the recording sheet 6 may be severely wrinkled or torn.

  Up to now, the problems in the sheet placing apparatus mounted on the image forming apparatus have been described. However, even in the sheet placing apparatus mounted on an ADF, a scanner, a post-processing apparatus (such as an alignment processing apparatus or a staple processing apparatus), Similar problems can arise.

  The present invention has been made in view of the above background, and an object thereof is to provide the following sheet placing apparatus, and an image forming apparatus and an image reading apparatus using the sheet placing apparatus. . That is, the sheet mounting that can align the sheet member without using the sheet size detecting means and avoid the occurrence of severe wrinkles and tears caused by feeding the sheet member out of the mounting surface in a greatly bent state. Device.

In order to achieve the above object, the invention according to claim 1 is a seating surface for placing a sheet-like sheet member, and a sheet along the placement surface and on the placement surface. By being disposed on the placement surface so as to move in the transport orthogonal direction, which is a direction orthogonal to the transport direction, and contacting one end of the sheet member placed on the placement surface in the transport orthogonal direction A first regulating member that regulates the position of the one end, a second regulating member that regulates the position of the other end by contacting the other end of the sheet member in the conveyance orthogonal direction, and a drive that is exerted by a drive source Drive transmission means for transmitting a force to at least the first restriction member of the first restriction member and the second restriction member to move the first restriction member in the conveyance orthogonal direction; The sheet member placed on the sheet is sent out from the placement surface. A sheet placed on the placement surface by regulating the position of the other end by the second regulating member while regulating the position of the one end by the first regulating member. In the sheet placing apparatus for aligning the position of the member in the conveyance orthogonal direction to a predetermined position, the member is disposed between the first restriction member and the second restriction member, and is described above by swinging about a swing shaft. The sheet member is freely reciprocated between a position contacting the placement surface and a position away from the placement surface, and the sheet member is moved forward by its own weight while being placed on the sheet member placed on the placement surface. It is arrange | positioned in the opposing part of the pressing member pressed toward the mounting surface, and the said mounting surface in the said pressing member, and approaches toward the said 1st control member from the center in the said conveyance orthogonal direction of the said mounting surface. As described above Beyond the al away tapered surface, a force attempting to prevent its movement relative to the first regulating member moving toward the seat member on the mounting surface by the driving force of the driving source is a predetermined threshold value The movement stop means for stopping the movement of the first restricting member based on the fact that it has been applied, and the surface of the surface due to the deflection of the sheet member placed on the placement surface by the displacement in the swinging direction of the pressing member . a surface position displacement detection means for detecting the position displacement, on the basis of the detection result by the surface position displacement detection means, setting the judging means for judging whether the deflection for the placed sheet member on the mounting surface The feeding means is configured to perform the process of starting the feeding of the sheet member from the placement surface only when the judgment means determines that there is no bending , and the drive source is driven. As the taper surface is rubbed against the upper edge of a bundle of a plurality of sheet members approaching the pressing member while being pressed by the first regulating member that is moved by movement, the swinging shaft is centered. Then, the pressing member is moved in a direction away from the placement surface to ride on the bundle .
Also, the invention of claim 2, in the seat mounting apparatus of claim 1, wherein the second regulating member disposed slidably on the mounting surface, and the driving force of the driving source, the second The drive transmission mechanism is configured to transmit forces in opposite directions along the conveyance orthogonal direction to the first regulating member and the second regulating member, and the first regulating member and the second regulating member The movement stopping means is configured to stop at the same timing, and in addition to the first tapered surface as the tapered surface, the center of the placement surface in the conveyance orthogonal direction is directed to the second regulating member. A plurality of sheets that are provided with a second tapered surface that moves away from the placement surface as approaching, and approach the pressing member while being pressed by the second regulating member that is moved by driving of the driving source. Part As the second tapered surface is rubbed against the upper edge of the bundle, the pressing member is moved away from the placement surface about the swing shaft to ride on the bundle. It is characterized by doing so.
According to a third aspect of the present invention, in the sheet placing apparatus according to the first or second aspect , there is provided drive stop means for stopping the drive of the drive source when the determination means determines that there is bending. It is what.
According to a fourth aspect of the present invention, in the sheet placing apparatus according to the third aspect , a process of determining whether or not the sheet member is bent based on a comparison between a detection result by the surface position displacement detection means and a predetermined threshold value. The determination means is configured to execute the above.
According to a fifth aspect of the present invention, in the sheet placing apparatus according to the fourth aspect , a minimum size sheet in which a separation distance in the conveyance orthogonal direction between the first restriction member and the second restriction member is determined as a design standard. The feeding means is configured to perform a process of not starting the feeding of the sheet member from the mounting surface when approaching a predetermined limit approach distance smaller than the short side dimension of To do.
The invention according to claim 6 is the sheet placing apparatus according to any one of claims 1 to 5 , for placing the rear end side in the transport direction of the sheet member in the entire area of the placing surface. The rear end side mounting surface is provided so as to be refracted with a predetermined refraction angle with respect to the front end side mounting surface for mounting the front end side of the sheet member. In the position where the member and the second regulating member can contact at least a refracting portion that is refracted along the refraction angle in the entire area of the sheet member placed on the placement surface, the conveyance orthogonality The presser member is disposed so as to be movable along the direction, and at least the refracting portion of the entire area of the sheet member placed on the placement surface is disposed on the placement surface. It is characterized by being pressed down.
According to a seventh aspect of the present invention, there is provided an image recording means for recording an image on the surface of a recording sheet as a sheet member, a recording sheet for sending out toward the image recording means, or after passing through the image recording means in the recording sheet an image forming apparatus and a sheet mounting device to align the recording sheet in a predetermined position on the mounting surface for placing the, as the sheet mounting apparatus, any one of claims 1 to 6 The sheet mounting apparatus is used.
According to an eighth aspect of the present invention, there is provided reading means for reading an image recorded on a document sheet, a recording sheet for sending out to the reading means, or a recording sheet after passing through the reading means. in the image reading apparatus and a sheet mounting device to align the recording sheet in the mounting surface for location in a predetermined position, as the seat mounting device, one of the sheet mounting apparatus of claims 1 to 6 It is characterized by being used.

In these inventions, when the first restricting member is moved in the conveyance orthogonal direction, the force to prevent the movement of the first restricting member exceeds a predetermined threshold value. The movement stopping means automatically stops the movement of the first restricting member, thereby stopping the first restricting member at a position corresponding to the size of the sheet member. Thereby, the sheet member can be aligned without using the sheet size detecting means.
Further, in these inventions, when the bending of the sheet member on the mounting surface is detected, the feeding of the sheet member by the feeding means is not performed, so that the seriousness caused by feeding the sheet member in a greatly bent state is prevented. Occurrence of wrinkles and tears can be avoided.

The side view which shows the manual feed tray in development and the recording sheet of the state bent largely. 1 is a schematic configuration diagram showing a copier according to an embodiment. FIG. 2 is an enlarged perspective view showing a scanner and an ADF of the copier. The enlarged block diagram which shows the same ADF and a scanner. FIG. 3 is an enlarged perspective view showing a manual feed tray of the copier. The disassembled perspective view which shows the 1st mounting part of the manual feed tray. The disassembled perspective view which shows the drive transmission mechanism of the 1st mounting part with two side fences. The expanded block diagram which expands and shows the drive restriction | limiting mechanism of the 1st mounting part. The wave form diagram which shows the waveform of the pulse signal output from the rotation detection sensor of the said 1st mounting part. The side view which shows the same manual feed tray from the side. FIG. 2 is a block diagram showing a part of an electric circuit of the copier. 6 is a flowchart showing processing steps of sheet alignment processing performed by a control unit of the copying machine. The partial front view which shows a part of the manual feed tray from the front. The partial front view which shows the same manual feed tray of the state which mounted the sheet | seat bundle. The partial front view which shows the same manual feed tray of the state which moved the sheet bundle to the rubbing position with a pressing member. The partial front view which shows the same manual feed tray of the state which made the press member ride on a sheet | seat bundle. The partial front view which shows the same manual feed tray of the state which complete | finished position alignment of a sheet bundle. The partial front view which shows the same manual feed tray of the state in which the sheet | seat bundle is mounted in the center vicinity of a baseplate. The partial front view which shows the same manual feed tray of the state which aligned the sheet bundle. The graph which shows the time-dependent change of the sheet displacement counter value Cm from the state shown in FIG. 18 to the state shown in FIG. FIG. 6 is a partial front view showing the manual feed tray 60 in a state where only one recording sheet is placed near the center of the bottom plate. The partial front view which shows the same manual feed tray of the state which aligned the recording sheet. The graph which shows the time-dependent change of the sheet displacement counter value Cm from the state shown in FIG. 21 to the state shown in FIG. The partial front view which shows the same manual feed tray of the state in which the sheet | seat bundle of the maximum stacking number is mounted in the area | region near the 2nd side fence in a bottom plate. The partial front view which shows the same manual feed tray of the state which made the pressing member ride on the same sheet bundle. FIG. 26 is a graph showing a change with time of the sheet displacement counter value Cm from the state shown in FIG. 24 to the state shown in FIG. 25; FIG. 7 is a partial front view showing one recording sheet that has been greatly bent in a state of being largely bent by the sheet alignment process together with the manual feed tray. 28 is a graph showing a change with time of the sheet displacement counter value Cm from immediately after the start of the sheet alignment process to the state shown in FIG. The flowchart which shows each process process in the alignment and pulse count process implemented by the control part. The partial front view which shows the same manual feed tray of the state which bent the recording sheet of the minimum size by the comparatively slight amount of bending. FIG. 3 is an enlarged perspective view showing a paper feed cassette of the copier. The top view which shows the 1st side fence and 2nd side fence in the manual feed tray which concern on a modification, and a recording sheet.

  Hereinafter, an embodiment of a copying machine including an image forming apparatus and an image reading apparatus to which the present invention is applied will be described. Note that the copying machine according to the embodiment is merely an example to which the present invention is applied, and the scope of application of the present invention is not limited to this copying machine.

  First, a characteristic configuration of the copying machine according to the embodiment will be described. FIG. 2 is a schematic configuration diagram illustrating the copying machine 1 according to the embodiment. The copying machine 1 includes an image forming apparatus including an image forming unit 4 and a paper feeding unit 5, and an image reading apparatus including an automatic document feeder (ADF) 2 and a scanner 3.

  The paper feed unit 5 of the image forming apparatus includes a paper feed cassette 41 that stores a recording sheet 6 as a sheet member on which an image is formed. The image forming unit 4 of the image forming apparatus includes four process cartridges 20Y, 20M, 20C, and 20K that form yellow (Y), magenta (M), cyan (C), and black (K) toner images. The image forming unit 4 as an image forming apparatus including the transfer device 30 is provided. The image reading apparatus also includes a scanner 3 that reads an image on a document sheet and an ADF 2 that automatically conveys the document sheet to a document reading position of the scanner 3. In the drawing, the copying machine according to the embodiment is shown from the front side, and the front side in the direction orthogonal to the drawing sheet corresponds to the front side of the copying machine and the back side corresponds to the rear side of the copying machine. If the copying machine is a main component, the left direction in the figure corresponds to the right direction of the copying machine, and the right direction in the figure corresponds to the left direction of the copying machine.

  The image forming unit 4 includes a transfer device 30 at a substantially central portion in the vertical direction. The transfer device 30 includes an endless intermediate transfer belt 32 as an intermediate transfer member, and a plurality of rollers disposed inside the loop, and the intermediate transfer belt 32 is formed into an inverted triangle shape by these rollers. It is stretched in shape. At the three apex positions in the inverted triangular shape, the support roller winds the intermediate transfer belt 32 around the roller circumferential surface with a large winding angle. Any one of the three support rollers causes the intermediate transfer belt 32 to move endlessly in the clockwise direction in the drawing by its own rotational drive.

  Of the three support rollers, the belt cleaning device is in contact with the support roller disposed on the leftmost side in the drawing from the outside of the loop. This belt cleaning device removes transfer residual toner adhering to the surface of the intermediate transfer belt 32 after passing through a secondary transfer nip described later from the belt surface.

  The belt region after passing through the contact position with the leftmost support roller in the figure and before entering the contact position with the rightmost support roller in the figure is substantially horizontal. It is a horizontal progression area that goes straight along. Above the horizontal traveling region, four process cartridges 20Y, 20M, 20C, and 20K for Y, M, C, and K are arranged in order along the belt moving direction. The process cartridges 20Y, 20M, 20C, and 20K are for forming Y, M, C, and K toner images for superimposing and transferring on the intermediate transfer belt 32. The copying machine according to the embodiment has a so-called tandem type configuration in which Y, M, C, and K toner images are formed in parallel by process cartridges 20Y, 20M, 20C, and 20K, respectively. In the copying machine according to the embodiment, the color arrangement order of Y, M, C, and K is adopted, but the color arrangement order is not limited to this order.

  In the image forming unit 4, the process cartridges 20Y, 20M, 20C, and 20K include drum-shaped photosensitive members 21Y, 21M, 21C, and 21K as image carriers. Around the photoconductor, a charging device including a charging roller (22Y, 22M, 22C, 22K), a developing device (24Y, 24M, 24C, 24K), a photoconductor cleaning device (23Y, 23M, 23C, 23K), A static elimination device (not shown) is disposed. In the charging device, a primary transfer bias is applied to charging rollers 22Y, 22M, 22C, and 22K, which are charging members disposed opposite to the photoreceptors 21Y, 21M, 21C, and 21K, by a power source (not shown). As a result, discharge occurs between the charging rollers 22Y, 22M, 22C, and 22K and the photoconductors 21Y, 21M, 21C, and 21K, so that the surfaces of the photoconductors 21Y, 21M, 21C, and 21K are uniformly charged. I'm damned. In the copying machine according to the embodiment, the charging rollers 22Y, 22M, 22C, and 22K are used to uniformly charge the surfaces of the photoreceptors 21Y, 21M, 21C, and 21K to a negative polarity that is the same polarity as the normal charging polarity of the toner. It has become.

  In addition, as a charging device for Y, M, C, and K, a corona charging method using a wire such as tungsten or a brush charging method using a conductive brush is adopted instead of a method using a charging roller. May be. Further, the charging member such as a charging roller may be arranged by a contact method in which the photosensitive members 21Y, 21M, 21C, and 21K are brought into contact with each other, or by a non-contact method in which they are brought into a non-contact state. May be. The non-contact method has a demerit that the gap between the charging member such as a charging roller and the photosensitive member is fluctuated due to the eccentricity of the photosensitive member. There is an advantage that the uneven charging due to the toner adhesion hardly occurs. As a primary transfer bias applied to a charging member such as a charging roller, it is preferable to employ a superimposed bias in which an AC voltage is superimposed on a DC voltage. This makes it possible to uniformly charge the surface of the photoconductor as compared with the case where only a DC voltage is applied.

  An exposure apparatus 10 is disposed above the four process cartridges 20Y, 20M, 20C, and 20K. The exposure device 10 and the charging devices for Y, M, C, and K constitute a latent image forming unit that forms an electrostatic latent image on the photoreceptors 21Y, 21M, 21C, and 21K. The exposure apparatus 10 uses Y, M, C, and K writing light generated based on image information obtained by reading an image by the scanner 3 or image information sent from an external personal computer or the like. In the figure, the uniformly charged surfaces of the photoconductors 21Y, 21M, 21C, and 21K that are rotationally driven in the counterclockwise direction are optically scanned. Of the entire surface of the photoconductors 21Y, 21M, 21C, and 21K, the exposed portion that has undergone optical scanning attenuates the potential compared to the background portion that has not undergone optical scanning. As a result, an electrostatic latent image is carried on the exposure unit. Examples of the exposure apparatus 10 include those that generate writing light with a laser diode and those that generate writing light with an LED array.

  The Y, M, C, and K electrostatic latent images carried on the surfaces of the photoreceptors 21Y, 21M, 21C, and 21K are attached with Y, M, C, and K toners by the developing devices 24Y, 24M, 24C, and 24K. As a result, the toner images are visualized as Y, M, C, and K toner images. The photoreceptors 21Y, 21M, 21C, and 21K are in contact with the intermediate transfer belt 32 to form a primary transfer nip. On the back side of the primary transfer nip for Y, M, C, and K, primary transfer rollers for Y, M, C, and K disposed inside the loop of the intermediate transfer belt 32 are photoreceptors 21Y, An intermediate transfer belt 32 is sandwiched between 21M, 21C, and 21K. The primary transfer rollers for Y, M, C, and K are each applied with a positive primary transfer bias having a polarity opposite to the normal charging polarity of the toner. In the Y primary transfer nip, the Y toner image formed on the photoreceptor 21 </ b> Y is primarily transferred onto the front surface of the intermediate transfer belt 32. The belt surface on which the Y toner image is primarily transferred in this way then passes through the primary transfer nips for M, C, and K in order. In this process, the M, C, and K toner images on the photoreceptors 21M, 21C, and 21K are sequentially superimposed and primarily transferred to form a color toner image on the belt surface.

  The surface of the photoconductors 21Y, 21M, 21C, and 21K after passing through the primary transfer nips for Y, M, C, and K is cleaned with transfer residual toner by photoconductor cleaning devices 23Y, 23M, 23C, and 23K. The Thereafter, it is neutralized by a neutralization device (not shown) to prepare for another image formation.

  Of the three support rollers disposed in the loop of the intermediate transfer belt 32, a secondary transfer roller 33 as a secondary transfer unit is provided from the outside of the loop at a belt winding portion around the support roller disposed at the lowermost position. A secondary transfer nip is formed by contact. A secondary transfer bias is applied to the secondary transfer roller 33 or the support roller by a power source (not shown). As a result, a secondary transfer electric field is formed between the support roller and the secondary transfer roller 33 to electrostatically move the color toner image on the intermediate transfer belt 32 toward the secondary transfer roller 33.

  On the right side of the secondary transfer nip in the drawing, there is provided a registration roller pair 45 composed of a pair of rollers that are in contact with each other to form a registration nip and rotate in the forward direction. A recording sheet 6 sent out from a sheet feeding unit 5 to be described later is sandwiched between registration nips of a registration roller pair 45. The registration roller pair 45 then feeds the toner image toward the secondary transfer nip at a timing synchronized with the color toner image on the intermediate transfer belt 32. The color toner image on the intermediate transfer belt 32 is secondarily transferred to the recording sheet 6 sandwiched between the secondary transfer nips by the action of a secondary transfer electric field or nip pressure. The recording sheet 6 on which the color toner image is secondarily transferred in this way passes through the conveying belt 34 that moves endlessly from the secondary transfer nip, and then is fed into the fixing device 50. The fixing device 50 performs a toner image fixing process by heating or pressing the recording sheet 6 sandwiched in a fixing nip formed by contact between a fixing roller 51 as a fixing member and a pressure roller 52. Apply.

  The recording sheet 6 sent out from the fixing device 50 approaches the conveyance path branch point where the conveyance path repeating claw 47 is disposed. The conveyance path switching claw 47 switches the sheet conveyance path on the downstream side of itself between the discharge path and the reverse conveyance path 87. When the single-sided printing mode is selected as the printing operation mode, the conveyance path switching claw 47 selects the discharge path as the sheet conveyance path. Also, when the duplex printing mode is selected and the recording sheet 6 sent out from the secondary transfer nip carries toner images on both sides, the conveyance path switching claw 47 uses the discharge path as the sheet conveyance path. select. The recording sheet 6 that has entered the discharge path passes through the discharge nip of the discharge roller pair 46 and is then discharged outside the apparatus. Then, they are stacked on the paper discharge tray 80 fixed to the outer surface of the housing.

  On the other hand, when the double-sided printing mode is selected and the recording sheet 6 fed from the secondary transfer nip carries a toner image only on the first side of the both sides, the conveyance path switching claw 47 carries the sheet. The reverse conveyance path 87 is selected as the path. Therefore, in the double-sided print mode, the recording sheet 6 carrying the toner image only on the first side is sent out from the fixing device 50 and then enters the reverse conveyance path 87. A reverse transport device 89 is disposed in the reverse transport path 87. The reversing / conveying device 89 temporarily stacks in the relay tray 88 while reversing the recording sheet 6 sent from the fixing device 50, or re-conveys it to the registration nip of the registration roller pair 45 described above. It is something to do. The recording sheet 6 returned to the paper feed path 46 by the reverse conveying device 89 passes through the secondary transfer nip again from the registration roller pair 45, so that the toner image is also secondarily transferred to the second surface. Then, after sequentially passing through the fixing device 50, the conveyance path switching claw 47, the paper discharge path, and the paper discharge roller pair 46, they are stacked on the paper discharge tray 80.

  In the double-sided print mode and the continuous print mode, double-sided printing is performed on each of the plurality of recording sheets 6. In this copying machine, printing on the first side of the recording sheet 6 and printing on the second side are performed together. For example, when performing double-sided printing on each of the 12 recording sheets 6, first, the first recording sheet 6 with the toner image fixed on the first surface is turned upside down and stacked in the relay tray 88. Next, the second recording sheet 6 having the toner image fixed on the first surface is turned upside down and stacked on the first recording sheet 6 in the relay tray 88. The same operation is repeated up to the 12th recording sheet 6. As a result, a bundle of the first, second, third,. Next, after the twelfth recording sheet 6 is sent out from the relay tray 88 to the paper feed path 46, a toner image is also formed on the second surface of the recording sheet 6. Then, the recording sheet 6 is discharged onto the discharge tray 80. Similarly, the printing of the toner image on the second surface and the paper discharge process are sequentially performed on the 11, 10, 9... First recording sheet 6.

  The paper feeding unit 5 disposed immediately below the image forming unit 4 includes two paper feeding cassettes 41, a paper feeding path 48, a plurality of conveying roller pairs 44, and the like that are arranged in multiple stages. A sheet feeding cassette 41 as a sheet placing device is attached to and detached from the casing of the sheet feeding unit 4 by sliding movement in the front-rear direction (a direction perpendicular to the drawing sheet). A sheet feeding roller 42 supported by supporting means in the housing is pressed against the recording sheet bundle in the paper feeding cassette 41 set in the housing of the paper feeding unit 4. When the paper feed roller 42 is driven to rotate in this state, the uppermost recording sheet 6 of the recording sheet bundle is sent out toward the paper feed path 48. The sent recording sheet 6 enters the conveyance separation nip due to the contact between the conveyance roller and the separation roller 43 before reaching the paper feed path 48. Of these two rollers, the conveyance roller is rotationally driven in a direction in which the recording sheet 6 is fed from the paper feed cassette 41 side toward the paper feed path 48 side. On the other hand, the separation roller 43 is rotationally driven in a direction to feed the recording sheet 6 from the paper feed path 48 side to the paper feed cassette 41 side. However, the drive transmission system that transmits the rotational driving force to the separation roller 43 is provided with a torque limiter. When the separation roller 43 is in direct contact with the conveying roller, torque exceeding the upper limit is applied to the torque limiter. work. As a result, the rotation driving force is not connected to the separation roller 43, and the separation roller 43 rotates around the transport roller. On the other hand, when the recording sheet 6 enters the conveyance separation nip in a state where the recording sheets 6 are overlapped, a slip is generated between the sheets, so that the torque acting on the torque limiter is lower than the upper limit. As a result, the separation roller 43 is driven to rotate, and among the plurality of recording sheets 6, the recording sheet 6 that is in direct contact with the recording sheet 6 is reversely conveyed toward the paper feed cassette 41. This reverse conveyance continues until the recording sheet 6 in the conveyance separation nip becomes one sheet and no slip occurs between the sheets. As a result, the recording sheet 6 is sent to the paper feed path 48 in a state of being finally separated into one sheet. Then, after passing through a conveyance nip in each of the plurality of conveyance roller pairs 44, the registration roller nip of the registration roller pair 45 of the image forming unit 4 is reached.

  The right side surface of the housing of the image forming unit 4 in the figure supports a manual feed tray 60 as a sheet placing device. The manual feed tray 60 presses the manual feed roller 601 against the uppermost recording sheet 6 in the bundle of recording sheets 6 placed on the sheet placement surface. Then, the uppermost recording sheet 6 is sent out toward the registration roller pair 45 by the rotation driving of the manual paper feed roller 601. The sent recording sheet 6 passes through a conveyance separation nip due to contact between the conveyance roller 603 and the separation roller 602 before reaching the registration roller pair 45. At this time, the recording sheet P is separated into only one sheet based on the same principle as the conveyance separation nip disposed on the side of the paper feed tray 41.

  FIG. 3 is an enlarged perspective view showing the scanner 3 and the ADF 2 of the copying machine according to the embodiment. As shown in the figure, the scanner 3 and the ADF 2 mounted thereon are connected by a hinge 399, and the ADF 2 is supported by the scanner 3 so as to be swingable in the direction of the arrow in the figure. Yes. Due to the swing, the ADF 2 moves to the position where the first contact glass 300 and the second contact glass 301 forming the upper surface of the scanner 3 are exposed (open state), or rides directly above the contact glass. Move to a position (closed state). In the copying machine according to the embodiment, when making a copy of a document that is difficult to set on the ADF 2 to be described later, such as a thick paper document or a single-stitched document, the ADF 2 is opened to expose the upper surface of the scanner 3 as illustrated. . Then, after setting the document on the first contact glass 300, the ADF 2 is closed and the document is pressed by the ADF 2. Then, when the copy start button 900 of the operation display unit 9 fixed to the scanner 3 is pressed, the copying machine is caused to start a copying operation.

  FIG. 4 is an enlarged configuration diagram showing the ADF 2 and the scanner 3. When making a copy of the original sheet P that can be automatically conveyed by the ADF 2, as shown in the drawing, with the ADF 2 closed with respect to the scanner 3, a single original sheet P or a bundle of original sheets is transferred to the ADF 2. On the original document tray 200. Then, the copy start button 900 described above is pressed to start the copy operation. The copy operation mainly includes a document reading operation by the scanner 3 and an image forming operation by the image forming unit (4). The document reading operation is started immediately after the copy start button is pressed. .

  The scanner 3 includes a traveling body 302, an imaging lens 310, an image reading sensor 320, and the like under the first contact glass 300 and the second contact glass 301. The second traveling body 302 includes a scanning lamp 303 and a plurality of reflecting mirrors, and can travel in the left-right direction in the drawing by a driving mechanism (not shown). The light emitted from the scanning lamp 303 is reflected on the image surface of the original set on the first contact glass 300 or the original being conveyed on the second contact glass 301 to read the image. It becomes light. The image reading light is reflected by a plurality of reflecting mirrors mounted on the traveling body 302, and then reaches an image reading sensor 320 formed of a CCD or the like via an imaging lens 310 fixed to the scanner body, and the focal point in the sensor. Tie a statue at a position. Thereby, the image of the document is read.

  When reading an image of a document set on the first contact glass 300, the scanner 3 scans the document while moving the traveling body 302 from the illustrated position toward the right in the drawing. As a result, the image of the document is sequentially read from the left area to the right area in the drawing. On the other hand, when reading the image of the original sheet P set on the ADF 2, the scanning lamp 303 is turned on while the traveling body 302 is stopped at the position shown in the figure, and the light from the scanning lamp 303 is sent to the second contact glass. Irradiate toward 301. At this time, the ADF 2 starts conveying the document sheet P set on the document tray 200 and passes the document sheet P directly above the second contact glass 301 of the scanner 3. As a result, the image of the original sheet P is sequentially read from the front end side to the rear end side in the conveyance direction while the traveling body 302 is stopped.

  A document sheet P is set on the document tray 200 of the ADF 2 in a posture with the document reading surface facing upward. Above the bundle of document sheets set on the document tray 200, a paper feed roller 202 supported by a cam mechanism (not shown) so as to be movable in the vertical direction is disposed. The document sheet P is sent out from the document tray 200 by rotating the sheet feeding roller 202 while being in contact with the uppermost document sheet P of the document sheet bundle by the downward movement. The fed document sheet P enters the conveyance separation nip due to contact between the endless conveyance belt 203a and the reverse roller 203b. The conveying belt 203a is endlessly moved in the clockwise direction in the drawing by forward rotation of the driving roller accompanying forward rotation of a paper feeding motor (not shown) while being stretched by a driven roller and a driving roller that is rotationally driven. A reverse roller 203b that is driven to rotate clockwise in accordance with the forward rotation of the paper feed motor is in contact with the stretched surface of the transport belt 203a to form a transport separation nip. In the transport separation nip, the surface of the transport belt 203a moves in the paper feeding direction. When the reverse roller 203b is in direct contact with the conveyance belt 203a or when only one original sheet P is sandwiched in the conveyance separation nip, it is arranged in the drive transmission path from the paper feed motor to the reverse roller 203b. The provided torque limiter works to cut off the driving force from the paper feed motor to the reverse roller 203b. As a result, the reverse roller 203b follows the conveyance belt 203a and conveys the original sheet P in the paper feeding direction. On the other hand, when a plurality of document sheets P enter the conveyance separation nip, a slip occurs between the sheets, so that the torque acting on the torque limiter becomes lower than the threshold value. Thereby, the driving force from the paper feeding motor is connected to the reverse roller 203b, and the reverse roller 203b is rotationally driven in the clockwise direction in the drawing. Then, among the plurality of document sheets P, the document sheet P that is in direct contact with the document sheet P is conveyed toward the document tray 200. This reverse conveyance continues until there is only one recording sheet P in the conveyance separation nip. Thus, the recording sheet P is finally separated into only one sheet and passes through the conveyance separation nip.

  On the downstream side of the conveyance separation nip in the sheet conveyance direction, a curved conveyance path that is largely curved in an alphabetic U shape is disposed. The document sheet P that has passed through the conveyance separation nip is conveyed while being largely curved along the curved conveyance path while being sandwiched between the conveyance nips of the conveyance roller pair 204 disposed in the curved conveyance path. As a result, the upper and lower sides are inverted, and the original reading surface that has been directed upward in the vertical direction is directed downward. The original is read by passing directly above the second contact glass 301 while pressing the original reading surface against the second contact glass 301 of the scanner 3. The original sheet P that has passed right above the second contact glass 301 sequentially passes the first conveyance roller pair 205 after reading and the second conveyance roller pair 206 after reading.

  When the single-sided reading mode is selected as the reading operation mode, the switching claw 207 that can swing around the swinging shaft stops swinging in a posture as shown in the figure. In this posture, the original sheet P that has passed through the second conveying roller pair 206 after reading moves onto the paper discharge tray 209a and is stacked there without contacting the switching claw 207. On the other hand, when the double-sided reading mode is selected and the original sheet P sent out from the second conveying roller pair 206 after reading is one in which only one of the two sides is read, the switching claw 207 is illustrated. Take a posture with the free end facing downward rather than the state of. Then, the original sheet P that has passed through the conveying roller pair 206 after reading passes over the switching claw 207 and is sandwiched between the rollers of the relay roller pair 210. At this time, the two rollers of the relay roller pair 210 are each driven to rotate in a direction in which the original sheet P is conveyed toward the relay tray 209b existing on the right side in the drawing. For this reason, the original sheet P moves onto the relay tray 209b, but the rotational driving of the relay roller pair 210 is stopped immediately before the trailing edge of the sheet passes through the relay roller pair 210. Then, the two rollers of the relay roller pair 210 start to rotate in the opposite direction. At substantially the same time, the switching claw 207 moves again to the position shown in the figure. In this way, the document sheet P is switched back, and the document sheet P is conveyed from the relay roller pair 210 toward the retransmission roller pair 208 disposed almost directly above the post-reading conveyance roller pair 206. Is done.

  The original sheet P sandwiched between the rollers of the re-sending roller pair 208 is in a state in which the surface of the both sides where the image has not been read is directed upward in the vertical direction. In this state, when the re-sending roller pair 208 is rotationally driven and sent to the curved conveyance path described above, the surface on which the image has not yet been read is directed downward and passes directly above the second contact glass 301. Then, the image of the surface is read. When the original sheet P on which the image on the other side has been read in this way passes through the second conveying roller pair 206 after reading, the switching claw 207 takes the posture shown in the drawing. As a result, the original sheet P is stacked on the paper discharge tray 209a.

Next, a characteristic configuration of the copier according to the embodiment will be described.
FIG. 5 is an enlarged perspective view showing the manual feed tray 60 of the copying machine according to the embodiment. In the drawing, the manual feed tray 60 has a first placement portion 61, a second placement portion 62, and a pressing member 604. An arrow C in the drawing indicates a direction in which a recording sheet (not shown) placed on the manual feed tray 60 is sent out from the manual feed tray 60, that is, a sheet delivery direction. The first placement unit 61 receives a region on the leading end side of the entire region in the feeding direction of the recording sheet placed on the manual feed tray 60. Further, the second placement portion 62 receives the rear end side region of the entire region of the recording sheet in the sheet feeding direction, and swings within a predetermined range about the swing shaft. It is supported by the first placement unit 61. In the manual feed tray 60, the sheet receiving surface by the bottom plate 610 of the first loading unit 61 and the sheet receiving surface 621 by the thick plate-like second loading unit 62 are used to mount a recording sheet. Is configured. The former sheet receiving surface constituted by the bottom plate 610 functions as a leading end side mounting surface for mounting the leading end side of the recording sheet in the entire area of the mounting surface. In addition, the sheet receiving surface 621 of the second placement unit 62 functions as a rear end side placement surface on which the rear end side of the recording sheet is placed in the entire region of the placement surface.

  In the same figure, an arrow B indicates the conveyance orthogonal direction on the placement surface of the manual feed tray 60. A one-dot chain line L <b> 1 indicates a center line in the conveyance direction of the manual feed tray 60. The bottom plate 610 of the first placement unit 61 is provided with a slit extending in the conveyance orthogonal direction indicated by the arrow B. A first side fence 611 and a second side fence 612 that are slidable along the slits are disposed on the bottom plate 610. Each of these side fences includes a foot portion that extends to the bottom of the bottom plate 610 through a slit in the bottom plate 610, and this foot portion is supported by a drive transmission mechanism.

  The first side fence 611 as a first restricting member is for restricting the position of one end in the conveyance orthogonal direction of a recording sheet (not shown) placed on the placing surface. Further, the second side fence 612 as the second regulating member is for regulating the position of the other end in the conveyance orthogonal direction of the recording sheet (not shown) placed on the placement surface. While these two side fences keep the posture extending in the feeding direction indicated by the arrow C, they slide to move closer to the center line L1 or slide to move away from the center line L1. To do. In the state shown in the figure, the two side fences both stop at the position farthest from the center line L1 in the movable range. That position is the home position for each side fence.

  A guide accommodating portion for accommodating the extension guide 63 in a removable manner is formed at the rear end portion of the second placement portion 62. In the drawing, the state in which the extension guide 63 is accommodated in the second placement portion 62 is shown. From this state, the extension guide 63 is pulled out in the direction of the arrow A in the figure, thereby extending the extension guide 63. Can be extended toward the rear of the second placement portion 62. When placing a long recording sheet, the extension guide 63 is extended in this manner.

  FIG. 6 is an exploded perspective view showing the first placement portion 61 of the manual feed tray 60. In the same figure, the 1st mounting part 61 of the state which removed the bottom plate 610 shown in FIG. 5 is shown. The first placement unit 61 is provided with a drive transmission mechanism including a first rack gear 613, a second rack gear 614, a connection pinion gear 615, a drive limiting mechanism 616, and the like below the bottom plate. The rotational driving force is transmitted to the first side fence 611 and the second side fence 612 via this drive transmission mechanism, so that the side fences slide along the conveyance orthogonal direction on the bottom plate.

  FIG. 7 is an exploded perspective view showing the drive transmission mechanism of the first placement unit 61 together with two side fences. In the drawing, the first rack gear 613 is formed integrally with the foot portion of the first side fence 611, and from the foot portion, the center of the bottom plate (610 in FIG. 5) in the conveyance orthogonal direction (arrow B direction). The leg portion is cantilevered so as to extend straight along the conveyance orthogonal direction toward the line L1. Further, the second rack gear 614 is integrally formed with the foot portion of the second side fence 612, and the foot portion extends straight from the foot portion toward the center line L1 along the conveyance orthogonal direction. Cantilevered.

  The disc-shaped connection pinion gear 615 rotates around the rotation axis while being supported by the rotation axis extending along the vertical direction at the position of the center line L1. A plate-like first rack gear 613 is engaged with the connection pinion gear 615. In addition, a plate-like second rack gear 614 is meshed with a region of the entire circumference of the connection pinion gear 615 that is in a point symmetrical position of 180 ° with respect to a region meshed with the first rack gear 613. .

  One of the two long sides of the plate-like first rack gear 613 is formed with a tooth portion for meshing with the connection pinion gear 615. On the other long side, a tooth portion for meshing with a gear portion of a driven drive transmission member of a drive limiting mechanism 616 described later is formed. In the first rack gear 613, the latter tooth portion is a driving tooth portion, whereas the former tooth portion is a driven tooth portion.

  A drive motor 617 is disposed on the side of the drive limiting mechanism 616, and an endless timing belt 618 is wound around the motor gear of the drive motor 617. The timing belt 618 is stretched around a timing pulley (described later) of the drive limiting mechanism 616 to be stretched with a predetermined tension. When the drive motor 617 is rotationally driven in the forward rotation direction, the rotational driving force is transmitted to the timing belt 618 and the drive limiting mechanism 616, and then the gear portion of the driven drive transmission member of the drive limiting mechanism 616 and the first rack gear. The force in the rotational direction is converted into the force in the direction perpendicular to the conveyance at the meshing portion with 613. Then, the first side fence 611 integrally formed with the first rack gear 613 slides from the illustrated position toward the center line L1. At the same time, the force in the conveyance orthogonal direction of the first side fence 611 is converted into a force in the rotational direction at the meshing portion between the first side fence 611 and the connection pinion gear 615, and the connection pinion gear 615 rotates in the forward rotation direction. This rotational force is converted into a force in the conveyance orthogonal direction at the meshing portion of the connection pinion gear 615 and the second rack gear 614, and the second side fence 612 integrally formed with the second rack gear 614 is centerlined from the illustrated position. Slide to L1.

  On the other hand, when the drive motor 617 is rotationally driven in the reverse direction, the rotational driving force is sequentially transmitted to the timing belt 618 and the drive limiting mechanism 616, and then the first side fence 611 is extended from the center line L1 side to one end in the conveyance orthogonal direction. It slides toward the side (the side where the first side fence 611 is located in the figure). At the same time, the first rack gear 613 integrally formed with the first side fence 611 slides while reversing the connecting pinion gear 615. Then, the rotational force in the reverse rotation direction of the connection pinion gear 615 is transmitted to the second rack gear 614, and the second side fence 612 is moved from the center line L1 side to the other end side in the conveyance orthogonal direction (the second side fence 612 is positioned in the figure). Slide toward (the side that is).

  As described above, when the drive motor 617 is rotationally driven in the forward rotation direction, the two side fences slide to move toward each other from the end side in the conveyance orthogonal direction toward the center line L1. As a result, the distance between the two side fences gradually decreases. On the other hand, when the drive motor 617 is rotationally driven in the reverse direction, the two side fences slide to move away from the center line L1 side in the conveyance orthogonal direction (arrow B direction) toward the end side. As a result, the distance between the two side fences gradually increases. Regardless of the movement position of the two side fences, the distance from the center line L1 to the first side fence 611 and the distance from the second side fence 612 to the center line L1 are equal to each other. Therefore, regardless of the movement position of the two side fences, the center between the fences is the position of the center line L1.

  On the side of the drive motor 617, a home position sensor 650 composed of a transmission type photo sensor is disposed. In the same figure, the 1st side fence 611 and the 2nd side fence 612 have shown the state located in a home position, respectively. In this state, as shown in the figure, the first side fence 611 has a test portion protruding downward from its own foot between the light emitting element and the light receiving element of the home position sensor 650. . Thereby, the home position sensor 650 detects that the first side fence 611 is located at the home position. In addition, as in the home position sensor 650, in place of the one that optically detects that the first side fence 611 is located at the home position, one that performs detection by other methods such as magnetic detection. May be adopted.

  When an operator places only one recording sheet or a sheet bundle on the manual feed tray 60 shown in FIG. 5, the operation display unit of the copying machine is first prior to placing the sheet. Press a manual feed execution button (not shown) provided in. Then, a control unit serving as a drive control unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like provided in the image forming unit (4) is controlled by the home position sensor 650. The drive motor 617 is driven in the reverse direction until the movement of the one side fence 611 to the home position is detected. Thereby, the 1st side fence 611 and the 2nd side fence 612 each stop in the position of a home position. The first placement unit 61 includes a paper detection sensor (not shown) under an opening (not shown) provided in the bottom plate 610. This paper detection sensor is composed of a reflective photosensor or the like, and when a recording sheet is placed on the bottom plate 610, the recording sheet is detected through an opening (not shown).

  FIG. 8 is an enlarged configuration diagram showing the drive limiting mechanism 616 of the first placement portion (61) in an enlarged manner. The drive limiting mechanism 616 includes a driving side drive transmission member 616a and a driven side drive transmission member 616d. The driven drive transmission member 616d includes a gear portion 616e that meshes with a first rack gear (613 in FIG. 7) that exists on the driven side of itself, and a plurality of slits (not shown) that are arranged at a predetermined pitch in the rotational direction. The slit disk 616f is integrally formed. Further, the driving side drive transmission member 616a includes a timing pulley 616b around which a timing belt (618 in FIG. 7) that exists on the driving side of itself is wound. Both the driving side drive transmission member 616a and the driven side drive transmission member 616d are rotatably supported by a support shaft 616h penetrating therethrough. The driving side drive transmission member 616a is urged toward the driven side drive transmission member 616d by an urging means (not shown). Thereby, the driving side drive transmission member 616a is in pressure contact with the driven side drive transmission member 616d.

  When the driving side drive transmission member 616a is rotated by the endless movement of the timing belt (618 in FIG. 7), the driven side drive transmission member 616d is rotated around the driving side drive transmission member 616a. Then, the gear portion 616e of the driven drive transmission member 616d slides the first rack gear (613 in FIG. 7) not shown. However, when a load exceeding a predetermined threshold is applied to the driven side drive transmission member 616d, a force that prevents rotation of the driven side drive transmission member 616d by the load is applied to the driven side drive transmission member 616d and the driven side drive transmission member. It exceeds the frictional force between the two at the pressure contact portion with 616a. Then, in the pressure contact portion, the driving side drive transmission member 616a slips on the surface of the driven side drive transmission member 616a, so that the rotational driving force of the driving side drive transmission member 616a is transmitted to the driven side drive transmission member 616d. Disappear. As a result, the sliding movement of the first side fence (611 in FIG. 7) and the second side fence (612 in FIG. 7) that have been slid until then stops. As described above, when the load applied to the driven drive transmission member 616d exceeds a predetermined threshold, the drive limiting mechanism 616 cuts off transmission of the driving force from the drive drive transmission member 616a to the driven drive transmission member 616d. Thus, it functions as a movement stopping means for stopping the movement of the moving first side fence.

  In FIG. 5 described above, an operator who sets a recording sheet (not shown) on the placement surface composed of the bottom plate 610 of the first placement unit 61 and the sheet receiving surface 621 of the second placement unit 62 operates as follows. Press the alignment button on the display (9 in FIG. 3). Then, a control part starts the drive of the normal rotation direction of a drive motor (617 of FIG. 7). Thereby, the 1st side fence 611 and the 2nd side fence 612 which were located in the home position each begin to slide toward the center line L1. At this time, the distance between the first side fence 611 and the second side fence 612 is larger than the dimension in the conveyance orthogonal direction (arrow B direction) of a recording sheet (not shown) placed therebetween. In this state, a recording sheet (not shown) can freely move between the two side fences in the conveyance orthogonal direction. For this reason, even if the first side fence 611 and the second side fence 612 that have started sliding movement come into contact with the recording sheet, the recording sheet smoothly slides while being pushed toward the center line L1. Thereafter, the first side fence 611 and the second side fence 612 move to a position where the recording sheet is sandwiched between them, that is, a position where the distance between the two is equal to the dimension in the direction perpendicular to the conveyance direction of the recording sheet. At this time, since the side fences are pressed against each other via the recording sheet, the pressure applied to the side fences rapidly increases and exceeds a predetermined threshold value. At the same time, a load exceeding a predetermined threshold is applied to the driven drive transmission member (616d) of the drive limiting mechanism (616) described above, and the drive drive transmission member (616a) is driven by the driven drive transmission member ( Slip on the surface of 616d). Thereby, the sliding movement toward the center line L1 of the first side fence 611 and the second side fence 612 is stopped. Then, the recording sheet randomly placed on the manual feed tray 60 is aligned with the position of the center line L1 and is corrected to a posture along the conveyance direction (arrow C direction).

  In this configuration, the position in the recording sheet conveyance orthogonal direction on the sheet placement surface of the manual feed tray 60 is a predetermined position by the first side fence 611, the second side fence 612, the drive motor 617, the drive transmission mechanism, and the like. A sheet aligning device for aligning with the position of the center line L1 is configured. Then, the sliding movement of the side fences is stopped at a position where the distance between the first side fence 611 and the second side fence 612 is substantially the same as the dimension in the conveyance orthogonal direction of the recording sheet set therebetween. Thereby, the recording sheet can be surely corrected to a straight posture along the conveyance direction (arrow C direction) on the placement surface. Therefore, the occurrence of jam and skew of the recording sheet can be suppressed as compared with the conventional case. Even when an irregular-size recording sheet is used, the recording sheet can be automatically aligned with the position of the center line L1 without inputting the dimensions of the recording sheet to the operation display unit.

  Note that the driving side drive transmission member 616a is used as the driven side drive transmission member with a load applied to the driven side drive transmission member 616d as a threshold at the moment when the recording sheet is sandwiched between the first side fence 611 and the second side fence 612. To slip on 616d, the following may be done. That is, the driving drive member 616a has a slightly weaker frictional force than the force exerted on the driven drive transmission member 616d to stop the rotation of the driven drive transmission member 616d. And the driven drive transmission member 616d. The frictional force is adjusted to an arbitrary value by appropriately setting the surface friction resistance in the pressure contact area of the driving side drive transmission member 616a and the surface friction resistance in the pressure contact area of the driven side drive transmission portion 616d. It is possible. As the drive limiting mechanism 616, a torque limiter on the general market may be used.

  In this copying machine, a toner image is formed on each color photoconductor (21Y, M, C, K) by the center reference method. The center reference method is a method in which an image is formed with reference to the center in the rotation axis direction of the photoreceptor regardless of the size of the recording sheet used. In such a center reference method, it is necessary to transport the recording sheet at the center position in the axial direction of the photoreceptor in the image forming unit 4 regardless of the size of the recording sheet. Therefore, in FIG. 5, the recording sheet is aligned with the position of the center line L1 on the manual feed tray 60. In order to enable the recording sheet to be aligned with the position of the center line L1 regardless of the size of the recording sheet, the following configuration is employed. That is, not only the first side fence 611 but also the second side fence 612 is arranged so as to be slidable on the placement surface, and the first side fence 611 and the second side fence 612 are perpendicular to the conveyance direction. The drive transmission mechanism is configured to transmit the forces in the opposite directions along. Further, a drive transmission mechanism that is a movement stop means including a drive restriction mechanism 616 is configured so that the first side fence 611 and the second side fence 612 are stopped at the same timing.

  As a method for determining the reference position of the image, there is a side reference method in addition to the center reference method. The side reference method is a method for forming an image based on the position of one end of the photosensitive member in the rotation axis direction regardless of the size of the recording sheet used. In such a side reference method, it is necessary to transport the recording sheet at one end position in the axial direction of the photoreceptor in the image forming unit 4 regardless of the size of the recording sheet. For this reason, when the side reference method is adopted, it is desirable to adopt the following configuration instead of the configuration in which the two side fences are slid. That is, in the conveyance orthogonal direction, the second side fence 612 is fixedly disposed on an extension line at one end position in the rotation axis direction of the photosensitive member. Then, only the first side fence 611 is slid to align the recording sheet set on the placement surface with the position of the second side fence 612. In the side reference system, only one side fence that can slide is provided, and the role of the other side fence may be assigned to the tray side wall.

  In the case of stopping the sliding movement of the first side fence 611 and the second side fence 612 by cutting off the transmission of the driving force from the driving side to the driven side as in the copying machine according to the embodiment, the driving motor 617 is stopped. These side fences can be stopped in a state where the is driven. For this reason, it is not essential to stop driving the drive motor 617 when stopping the side fence, but continuing to drive the drive motor 617 as usual will result in wasteful energy consumption and reduced life due to equipment consumption. Etc., which is not preferable. Therefore, it is desirable to stop the drive motor 617 without taking much time after the side fence stops. Therefore, in the copying machine according to the embodiment, an operation detecting unit that detects whether or not the driven drive transmission member 616d is operating is provided. Then, the control unit as the drive control unit is configured to perform the process of stopping the drive motor 617 in the forward rotation direction based on the fact that the operation detection unit no longer detects the operation of the driven drive transmission member 616d. It is composed. As the motion detection means, a rotation detection sensor 619 that detects the rotation of the slit disk 616f of the driven drive transmission member 616d is used. As shown in FIG. 7, the rotation detection sensor 619 includes a light emitting element arranged to face the upper surface of the slit disk 616f, and a light receiving element arranged to face the lower surface of the slit disk 616f. A slit disk 616f is sandwiched between them. Each time a plurality of slits provided in the slit disk 616f so as to be arranged at a predetermined pitch in the rotation direction pass through a position facing the light emitting element as the slit disk 616f rotates, the light receiving element is moved to the light emitting element. Receives light from. Thus, when the driven drive transmission member 616d rotates at a constant angular velocity, a pulse signal as shown in FIG. 9 is repeatedly output from the rotation detection sensor 619 at a constant cycle (Δt). On the other hand, when the rotation of the driven drive transmission member 616d stops, the pulse signal is not output from the rotation detection sensor 619 at a constant period (Δt). The output at this time varies depending on the rotation stop posture of the slit disk 616f. Specifically, when the rotation of the slit disk 616f is stopped in such a position that the portion between the slits is positioned in a region facing the light emitting element of the rotation detection sensor 619, the slit disk 616f is in response to the light receiving element of the rotation detection sensor 619. Light from the light emitting element is not incident. For this reason, the output of the rotation detection sensor 619 continues to be OFF. On the other hand, when the rotation of the slit disk 616f is stopped in a posture in which the slit is positioned in a region facing the light emitting element of the rotation detection sensor 619, the light from the light emitting element is applied to the light receiving element of the rotation detection sensor 619. Continues to enter. For this reason, the output of the rotation detection sensor 619 continues to be ON. In any case, the OFF or ON state continues beyond the pulse signal generation cycle (Δt). Therefore, the control unit has changed from a state in which the pulse signal from the rotation detection sensor 619 is output at a constant cycle to a state in which the output OFF state or ON state continues beyond “cycle Δt + constant α”. Sometimes, it is determined that the rotation of the driven drive transmission member 616d has stopped. Then, as soon as this determination is made, the drive of the drive motor 617 in the forward direction is stopped.

  The drive amount from the drive start to the drive stop of the two side fences correlates with the total movement amount from the home position to the stop position in the side fences. Further, the total correlates with a dimension (hereinafter, referred to as a sheet width dimension) in the conveyance orthogonal direction of the recording sheet set between the fences. For this reason, it is possible to construct a functional expression or a data table for obtaining the sheet width dimension based on the driving amount. Therefore, as shown in FIG. 13, the control unit of the copying machine performs a process of counting the pulse number integrated value from the start of driving to the stop of driving as the driving amount. In addition, a functional expression or data table for obtaining the sheet width dimension based on the pulse number integrated value is stored in the ROM as the data storage means. Then, the process of obtaining the sheet width dimension by substituting the counting result of the pulse number integrated value into the function formula or the process of specifying the sheet width dimension corresponding to the counting result from the data table is performed. Thereby, the sheet width dimension of the recording sheet set on the placement surface of the manual feed tray 60 is specified. In such a configuration, the sheet width dimension of the recording sheet set on the placement surface of the manual feed tray 60 can be automatically specified by the control unit without being input to the operation display unit.

When the drive motor 617 is driven at a constant driving speed to slide the fences regardless of the positions of the two side fences, the pulse number integrated value is used as the drive amount from the start of driving to the stop of driving. Instead of this, a driving time which is a time required from the start of driving to the stop of driving may be employed. In this case, the sheet width dimension L _x is obtained by a functional expression “L _x = L ₀ −t _f × 2V _f ”. In this functional equation, L ₀ represents the initial distance between the fences [cm] when the two side fences are at the home positions. Also, _{t f} represents a fence travel time [s]. V _f represents the moving speed [cm / s] in each side fence, and is positive or negative for indicating the moving direction toward one end side or the other end side along the conveyance orthogonal direction. The value without the sign of.

  As described above, in FIG. 8, the drive limiting mechanism 616 serving as the movement stopping means is driven from the driving side drive transmission member 616a to the driven side drive when the load applied to the driven side drive transmission member 616d exceeds a predetermined threshold. By stopping the transmission of the driving force to the transmission member 616d, the moving first side fence is stopped. In this copying machine, as a method for realizing that the transmission of the driving force from the driving side drive transmission member 616a to the driven side drive transmission member 616d is cut off when the load exceeds a predetermined threshold value, the rotating driving side drive A method is employed in which the driven drive transmission member 616d is rotated by pressure contact with the transmission member 616a. Instead of this method, a method may be employed in which the driven drive transmission member is linearly moved in the same direction by pressure contact with the driving drive transmission member that moves linearly.

  The threshold value of the load applied to the driven drive transmission member 616d is based on the load generated when one sheet of thin paper is sandwiched between the two side fences that are slidingly moved (hereinafter referred to as the load when the thin paper is sandwiched). It is desirable to make it smaller. By doing this, even when a thin sheet of paper is set, the drive transmission to the two side fences can be cut off at the moment when it is sandwiched between the two side fences. is there. On the other hand, as a threshold value, when a recording sheet bundle having a maximum stacking capacity that can be placed on the manual feed tray 60 is placed, a load generated when the recording sheet bundle is slid (hereinafter referred to as the maximum stacking capacity). It is desirable to make it larger than the load during bundle movement. If this is not done, the recording sheet bundle having the maximum stacking capacity cannot be slid by the side fence and cannot be aligned. Therefore, it is desirable to satisfy the relationship of “maximum load when moving stack bundle <threshold <load when sandwiching thin paper”. For this purpose, the load when the thin paper is sandwiched must be larger than the load when moving the maximum stack, but generally the opposite is true.

  Therefore, the copying machine according to the embodiment employs the following configuration. That is, as shown in FIG. 5, in the manual feed tray 60, the sheet receiving surface 621 that functions as the rear end side mounting surface is opposed to the bottom plate 610 that functions as the front end side mounting surface. It is provided so as to take a refracted posture with a refraction angle θ. The refraction angle θ is an angle formed by an extension line in the sheet conveyance direction (arrow C direction) of the front-side placement surface and an extension line in the sheet conveyance direction of the rear-end placement surface. The value is less than [°]. As described above, when the front-end-side placement surface (bottom plate 610) and the rear-end-side placement surface (sheet receiving surface 621) are refracted, the recording sheet placed on the placement surface is refracted. The posture is refracted along the angle θ. As shown in FIG. 10, the second side fence 612 is disposed so as to slide and move at a position where the second side fence 612 can come into contact with the refracting portion of the recording sheet 6. Similarly, the first side fence 611 is disposed so as to slide at a position where the first side fence 611 can come into contact with the refracting portion of the recording sheet 6. Therefore, these side fences extend in a region from the rear end portion of the first placement portion 61 to the front end portion of the second placement portion 62, and the first placement portion 61 and the second placement portion. It is configured to be refracted according to the refraction angle θ at the boundary with 62. In the recording sheet 6, the refracted portion refracted on the boundary between the first placement portion 61 and the second placement portion 62 is compared with a sheet portion that is not refracted when sandwiched between two side fences. A large load is applied to the driven drive transmission member 616d. This makes it possible to set a threshold value that realizes the relationship of “maximum load bundle movement load <threshold <load during thin paper pinching” by making the load during thin paper pinching greater than the load during maximum stack movement. became. The adjustment of the threshold value is performed by adjusting the surface friction resistance of the pressure contact portion of the driven side drive transmission member 616d and the surface friction resistance of the pressure contact portion of the driving side drive transmission member 616a so that the above-described relationship is realized. ing. In this way, even when only one sheet of thin paper is set on the loading surface of the manual feed tray 60, the plain paper can be removed without stopping the side fence during sliding movement. It is possible to satisfactorily align with the position of the center line L1. In addition, at the moment when a piece of plain paper is sandwiched between the fences, a load exceeding the threshold is surely applied to the driven drive transmission member 616d. Thereby, the sliding movement of the side fence can be stopped at an appropriate timing not to make the distance between the fences smaller than the sheet width dimension.

  FIG. 11 is a block diagram illustrating a part of an electric circuit of the copying machine according to the embodiment. In the figure, a control unit 400 as drive control means controls the drive of various devices mounted on the copying machine. Various devices are connected to the control unit 400, but only the devices related to the alignment of the recording sheet on the manual feed tray (60) are shown in FIG. The control unit 400 is connected to the drive motor 617, home position sensor 650, rotation detection sensor 619, paper detection sensor 66, slit sensor 68 operation display unit 900 and the like already described. A paper feed lifting motor 67 is also connected. The paper detection sensor 66 detects a recording sheet on the bottom plate 610 through an opening (not shown) of the bottom plate 610 shown in FIG. The paper feed lifting motor 67 is a motor for lifting the paper feed roller 601 shown in FIG. The role of the slit sensor 68 will be described later.

  FIG. 12 is a flowchart showing each processing step of the sheet alignment processing performed by the control unit 400. When the manual operation execution button of the operation display unit (900) is pressed by the operator (Y in step 1; hereinafter, “step” will be referred to as “S”), the control unit (400), The fence home alignment process (S3) is executed in order. In the paper feed roller raising process (S3), the paper feed lift motor (68) is reversely driven until a predetermined timing to raise the paper feed roller (601) to a position where it does not contact the sheet bundle on the placement surface. It is a process to make. The fence home alignment process (S3) is a process of driving the drive motor (617) in reverse until the first position fence (611) is detected by the home position sensor (610). Accordingly, the first side fence (611) and the second side fence (612) slide to the home position, respectively.

  After finishing the fence home alignment process (S3), the control unit (400) waits until the operator presses the alignment button on the operation display unit (900). When the alignment button is pressed (Y in S4), it is determined whether the recording sheet on the placement surface is detected by the paper detection sensor (66) (S5). If not detected (N in S5), an error message indicating that the recording sheet is not set is displayed on the liquid crystal screen of the operation display unit (900) (S6), and the processing flow is changed to S4. Loop. Thereby, it waits again until the alignment button is pressed. On the other hand, if the recording sheet on the placement surface is detected by the paper detection sensor (Y in S5), alignment and pulse count processing (S7) is executed. In the alignment and pulse count process (S7), the recording sheet is aligned with the position of the stop line L1 by the sliding movement of the two side fences, and the number of rotation pulse signals output from the rotation detection sensor (619) is calculated. This is a process of counting. Thereafter, based on the obtained rotation pulse count value, a size specifying process (S9) for specifying the sheet width dimension of the recording sheet placed on the manual feed tray (60) is executed.

  The control unit (400) that specified the sheet width dimension of the recording sheet by the size specifying process (S9) stores the value in the RAM (400b) (S10), and then executes the paper feed roller lowering process (S11). In this paper feed roller lowering process (S11), the paper feed lift motor (68) is driven to rotate forward until a predetermined timing, so that the paper feed roller (601) is placed at the top of the sheet bundle on the placement surface. This is a process of lowering to a position where it contacts the recording sheet. Thereafter, the control unit starts waiting for a print command issued from the user. Thereafter, when a print command is issued, the recording sheet is sent out from the manual feed tray (60) at an appropriate timing. Note that steps S8, S13, S14, and S15 in FIG. 12 will be described in detail later.

  As shown in FIG. 5, the manual feed tray 60 has a pressing member 604 disposed between the first side fence 611 and the second side fence 612. The pressing member 604 includes an arm portion 604a that is swingably supported by the swing shaft 697, a first tapered portion 604b and a second tapered portion 604c that are connected to the free end side of the arm portion 604a. . Then, it freely reciprocates between a position contacting the bottom plate 610 as a mounting surface and a position spaced apart from the bottom plate 610 by swinging about the swing shaft 617. When the recording sheet is placed on the bottom plate 610, the recording sheet is pressed against the bottom plate 610 by its own weight while being placed on the recording sheet. Thereby, the recording sheet 6 is reliably refracted at the refraction angle θ at the boundary between the first placement portion 61 and the second placement portion 62.

  FIG. 13 is a partial front view showing a part of the manual feed tray 60 from the front. In the same figure, the first taper portion 604b of the pressing member 604 has a tapered surface that moves away from the bottom plate 610 as it approaches the first side fence 611 from the center line (L1 in FIG. 5) at the portion facing the bottom plate 610. doing. Further, the second taper portion 604c has a taper surface that moves away from the bottom plate 610 as it approaches the second side fence 612 from the center line (L1 in FIG. 5) at a portion facing the bottom plate 610. In the state shown in the figure, the first side fence 611 and the second side fence 612 are each located at the home position. In this state, as shown in FIG. 14, it is assumed that the sheet bundle composed of a plurality of recording sheets 6 is placed on the first side fence 611 side from the center of the tray, and the driving of the side fence is started. Then, as shown in FIG. 15, the upper edge of the sheet bundle pushed toward the center of the tray by the first side fence 611 comes to slide on the tapered surface of the first tapered portion 604 b of the pressing member 604. . In the rubbing portion, a force in a direction away from the bottom plate 610 is applied to the pressing member 604 by the sheet bundle, so that the pressing member 604 is moved away from the bottom plate 610 while pushing the sheet bundle toward the center of the tray. To push up. With this push-up, the sheet bundle is moved onto the sheet bundle as shown in FIG. 16 without hooking the sheet bundle on the holding member 604, and the sheet bundle is moved to the center of the tray as shown in FIG. . In this way, the sheet bundle can be aligned without being caught on the pressing member 604.

  The example of aligning the sheet bundle placed on the first side fence 611 side from the tray center has been described, but the same applies to the sheet bundle placed on the second side fence 612 side from the tray center. The sheet bundle can be aligned without being caught on the pressing member 604.

  In FIG. 5 shown above, one end portion of the tension coil spring 691 is fixed to the arm portion 604 a of the pressing member 604. The other end of the tension coil spring 691 is fixed to the case of the first placement unit 61. As a result, a slight force is applied to the pressing member 604 in the direction away from the bottom plate 610 around the swing shaft 617, so that the pressing member 604 is pressed against the bottom plate 604 with a force weaker than the load. Yes.

  A slit plate 692 having a plurality of slits extending radially about the swing shaft 617 is fixed to the arm portion 604a. In addition, a slit sensor 693 composed of a transmissive photosensor that detects the slit of the slit plate 692 is fixed to the case of the first placement unit 61. When the pressing member 604 swings about the swing shaft 617, the slit of the slit plate 692 passes through the slit detection unit of the slit sensor 693. Each time the slit sensor 693 detects a slit, the slit sensor 693 outputs a detection signal corresponding to the moving direction of the slit. Specifically, when the pressing member 604 moves in a direction away from the bottom plate 610 and the slit moves downward from above, the slit sensor 693 that detects the slit outputs a rising pulse. Further, when the pressing member 604 moves in a direction approaching the bottom plate 610, when the slit moves from the lower side to the upper side, the slit sensor 693 that detects the slit outputs a falling pulse.

  The first placement unit 61 is provided with a paper detection sensor (66 in FIG. 11) (not shown). When a recording sheet is placed on the bottom plate 610, the recording sheet is detected by the paper detection sensor. . When the pressing member 604 is pushed up by the recording sheet placed on the bottom plate 610, the slit sensor 68 outputs a number of rising pulses corresponding to the pushed-up amount. The control unit (400 in FIG. 11) resets the sheet displacement counter value Cm, which is a control parameter, to zero when the state in which the recording sheet is not detected by the paper detection sensor 66 continues for a predetermined time. Thereafter, when a rising pulse is output from the slit sensor 693, the sheet displacement counter value Cm is incremented by one. When a falling pulse is output from the slit sensor 693, the sheet displacement counter value Cm is counted down by one. The sheet displacement counter value Cm that is increased or decreased in this way reflects the push-up amount from the initial state of the pressing member 604 (the state in contact with the bottom plate 610), and the push-up amount indicates the surface position of the recording sheet. Reflects. When the recording sheet is greatly bent as shown in FIG. 1, the surface position of the recording sheet is greatly increased, and the pressing member 604 is pushed up by the increase amount. Then, the sheet displacement counter value Cm is counted up by the number corresponding to the pushed-up amount. That is, in this copying machine, the combination of the slit plate 692, the slit sensor 693, and the control unit (400) detects the displacement of the surface due to the deflection of the recording sheet placed on the surface of the bottom plate 610 as the placement surface. It functions as surface position displacement detection means.

  The pressing member 604 includes a rear end tapered portion 604d as a tapered portion in addition to the first tapered portion 604b and the second tapered portion 604c. The rear end tapered portion 604d has a tapered surface that moves away from the sheet receiving surface 621 from the first placement portion 61 side (tray leading end side) toward the second placement portion 62 side (tray rear end side). Yes. When placing a sheet bundle on the manual feed tray 60, the user first places the leading end of the sheet bundle on the sheet receiving surface 621 of the second placement unit 62 while gripping the rear end of the sheet bundle. Then, the sheet bundle is pushed toward the first placement portion 61 from the second placement portion 62 side, and after the sheet bundle is abutted against the front end wall of the first placement portion 61, from the rear end portion of the sheet bundle Release the hand. In the process of pushing the sheet bundle to a position where it abuts against the front end wall, the sheet bundle is caused to ride on the pressing member 604 while sliding the front end of the sheet bundle against the rear end tapered portion 604d of the pressing member 604.

FIG. 18 is a partial front view showing the manual feed tray 60 in a state where a sheet bundle is placed near the center of the bottom plate 610. The illustrated sheet bundle includes a maximum number of stacked recording sheets 6 defined by the design standard. According to the instruction manual of the apparatus, attention is given to the user so as not to place a sheet bundle exceeding the maximum number of stacked sheets. When the sheet bundle is placed near the center of the bottom plate 610, the pressing member 604 is placed on the sheet bundle as illustrated. At this time, the sheet displacement counter value Cm described above changes from zero to a value corresponding to the thickness of the maximum number of stacked sheet bundles, h ₁ (h ₁ > 0). Thereafter, when the sheet alignment process is performed, as shown in FIG. 19, the sheet bundle is aligned with the center of the tray, but the height position of the surface of the sheet bundle is the same as before the alignment. For this reason, as shown in FIG. 20, the sheet displacement counter value Cm is kept constant at h ₁ from the start time t ₀ of the sheet alignment process to the end time t ₁ .

FIG. 21 is a partial front view showing the manual feed tray 60 in a state where only one recording sheet 6 is placed near the center of the bottom plate 610. When only one recording sheet 6 is placed near the center of the bottom plate 610, the pressing member 604 is hardly pushed up by the recording sheet 6. For this reason, the sheet displacement counter value Cm remains zero. Thereafter, when the sheet alignment process is performed and the recording sheet 6 is aligned at the center of the tray without bending as shown in FIG. 22, the height position of the pressing member 604 is the same as that before the sheet alignment. The same. Therefore, as shown in FIG. 23, from the start t ₀ of the sheet registration process, until reaching the end t _1, the sheet displacement counter value Cm is kept constant at zero.

FIG. 24 is a partial front view showing the manual feed tray 60 in a state in which the maximum number of stacked sheet bundles are placed in an area near the second side fence 612 in the bottom plate 610. In this state, the pressing member 604 does not ride on the sheet bundle. For this reason, the sheet displacement counter value Cm remains zero. Thereafter, when the sheet alignment process is started, as shown in FIG. 25, the pressing member 604 eventually rides on the sheet bundle. In the process of climbing in this manner, as shown in FIG. 26, the sheet displacement counter value Cm gradually increases, and eventually, according to the thickness of the maximum stack number of sheet bundles h ₁ (h ₁ > 0). Settle to the value.

FIG. 27 is a partial front view showing one recording sheet 6 that has been aligned in a state of being largely bent by the sheet alignment process, together with the manual feed tray 60. Thus when the recording sheet 6 is aligned in a state of being largely deflected, as shown in FIG. 28, after a while from the processing start time t _0, the sheet displacement counter value Cm begins to increase. This is because the recording sheet 6 sandwiched between the two side fences bends and starts to push up the pressing member 604. Increase in sheet displacement counter value Cm is continued until the time point t ₂ when the driving motor is stopped. The value of the pulse counter at this time is h ₂ (h ₂ > 0). Since the drive limiting mechanism (616) does not operate when the recording sheet 6 is bent, the two side fences (611, 612) continue to move toward the center line until the drive motor is stopped. . Therefore, it is the sheet displacement counter value Cm continues to increase until time t _2.

The graph shown in FIG. 28 and the graph shown in FIG. 26 are similar in behavior, but the sheet displacement counter value Cm is different from each other. The value h ₂ corresponding to the deflection amount of the recording sheet 6 in FIG. 28 is larger than the value h ₁ corresponding to the thickness of the maximum number of stacked sheets in FIG. 26 (h ₂ > h ₁ ). In a stage before the sheet displacement counter value Cm is a value of h _2, for an increase of the sheet displacement counter value Cm, seemingly due to the pressing member 604 is about to Noriageyo the sheet bundle, sandwiched between the side fences It cannot be distinguished whether the recording sheet 6 is caused by a large deflection. However, in the former case, the sheet displacement counter value Cm increases only to h ₁ at the maximum, so that it can be determined that the latter is the stage when it becomes h ₂ larger than that. That is, when the sheet displacement counter value Cm during the sheet registration process has reached h ₂ was increased, no problem it is determined that a large deflection of the recording sheet 6 is occurring.

FIG. 29 is a flowchart showing each processing step in the alignment and pulse count processing (S7) shown in FIG. Control unit (400), when starting positioning and pulse count processing (S7), first, the sheet displacement counter value Cm, determines whether or not _{h 1} less (S7a). Here, when the sheet displacement counter value Cm is not h ₁ less it will have been placed a sheet bundle of recording sheets exceeds (N in S7a), the maximum number of stackable sheets. In such a case, after executing error processing (S7b) such as displaying that the number of sheets exceeds the maximum number of stacked sheets, the control unit loops the control flow to the end of FIG. On the other hand, when the sheet displacement counter value Cm is equal to or less than h ₁ (Y in S7a), the control unit starts the forward drive of the drive motor (617) (S7c), and sets the two side fences respectively. Start sliding from the home position toward the center line L1. Immediately after this, counting of the rotation pulse signal output from the rotation detection sensor (619 in FIG. 7) is started (S7d).

Thereafter, the control unit determines whether or not the sheet displacement counter value Cm is equal to or greater than h ₂ (S7e). Here, when the sheet displacement counter value Cm is h ₂ or more will be reached in h ₂ was increased (Y in S7e), seat displacement counter value Cm during the sheet registration process. This means that the recording sheet sandwiched between the two side fences is greatly bent, and the height position of the surface is moved above the surface height position in the maximum stack number of sheet bundles. . Therefore, after setting the sheet deflection flag (S7k), the control unit loops the control flow to S7i and stops the drive motor. Thereafter, the process proceeds to S8 in the flow shown in FIG. 12 through the step S7j, and it is determined that the flag is being set (Y in S8). The subsequent flow will be described in detail later.

On the other hand, the control unit, when the sheet displacement counter value Cm is determined that not h ₂ or more S7e process (N in S7e), the rotation pulse count Mk, determines whether exceeds a predetermined threshold value ( S7f). Here, when the rotation pulse count value Mk exceeds the threshold value, the two side fences have approached the critical approach distance smaller than the short side dimension of the minimum size recording sheet defined in the design standard. As shown in FIG. 30, the reason why the two side fences approach in this way is that the recording sheet of the minimum size is bent by an amount that does not allow the sheet displacement counter value Cm to reach h ₂ ( Hereinafter, case 1). Further, there may be a case where a recording sheet smaller than the minimum size defined in the design standard is set (hereinafter referred to as case 2). In case 1, if the recording sheet is sent out from the tray after that, there is a risk of causing severe wrinkles or tears. Further, in case 2, there is a possibility that an image portion that protrudes outside the size of the recording sheet at the secondary transfer nip is reversely transferred to the secondary transfer roller (33 in FIG. 2). Therefore, it is not desirable to perform a print job in any case. Therefore, if the control unit determines that the rotation pulse count value Mk exceeds the threshold (Y in S7f), after setting the fence approach error flag (S7k), the control flow is looped to S7i and the drive motor is turned on. Stop. Thereafter, the process proceeds to S8 in the flow shown in FIG. 12 through the step S7j, and it is determined that the flag is being set (Y in S8). The subsequent flow will be described in detail later. Note that the minimum size sheet specified as a design standard is specified as the minimum size sheet that can be used in the instruction manual of this copier, for example, “Please use paper of size XX or larger”. It is a sheet that has been.

  If the rotation pulse count value Mk does not exceed the threshold value in step S7f (N in S7f), alignment is being performed normally. Therefore, the control unit determines whether or not the output ON time (time during which the rising pulse continues in the rotation detection sensor (619)) exceeds “pulse period Δt + constant α” (S7g), or the output is OFF. It is determined whether or not the time (time when no rising pulse is generated) exceeds “pulse period Δt + constant α” (S7h). If either the output ON time or the output OFF time does not exceed “pulse period Δt + constant α” (N in S7g or S7h), the driven drive transmission member (616d) of the drive limiting mechanism (616) The drive transmission to the side fence continues due to the rotation. Therefore, the control unit loops the control flow to S7e described above and re-executes various determination processes. On the other hand, if either the output ON time or the output OFF time exceeds “pulse period Δt + constant α” (Y in S7g or S7h), the driven drive transmission member (616d) of the drive limiting mechanism (616) ) Stops and the side fence stops moving. Therefore, the control unit stops driving the drive motor (S7i), stores the pulse number integrated value in the RAM (400b), and ends the alignment and pulse count processing.

  As described above, if the recording sheet sandwiched between the two side fences is greatly bent during the alignment and pulse count processing, the alignment and pulse count processing is performed after the sheet deflection flag is set (S7k). Ends. In addition, when the two side fences are closer than the short side dimension of the minimum size recording sheet during the alignment and pulse count processing, the alignment and pulses are set after the fence approach error flag is set (S7m). The count process ends. When the sheet deflection flag and the fence approach error flag are set, it is determined that the flag is being set in the process of S8 shown in FIG. 12 (Y in S8). When the controller makes such a determination, “Please remove the bent recording sheet.”, “The recording sheet size may be too small or the recording sheet may be bent. After an error message such as “Check the size and state of the sheet” is displayed on the liquid crystal screen (S13), the process waits until the recording sheet is removed from the tray (S14). When the recording sheet is removed from the tray (N in S14), the sheet deflection flag or the fence approach error flag is canceled (S15), and the control flow is looped to S1.

  In the above control flow, the series of control flow of FIG. 12 is normally completed only when the control unit as the determination unit determines that the recording sheet on the tray is not bent (N in S7e), and the print job is completed. Recording sheet delivery based on the command is started. In such a configuration, it is possible to avoid the occurrence of severe wrinkles and tears caused by feeding the recording sheet on the tray in a largely bent state.

  2, the copying machine according to the embodiment includes not only the manual feed tray 60 but also the paper feed tray 41 of the image forming unit 4, the paper discharge tray 80 of the image forming unit 4, the document tray 200 of the scanner 3, Each of the relay trays 209b of the scanner 3 is also equipped with the sheet placing device according to the present invention. The configuration of these sheet placing apparatuses is the same as that of the manual feed tray 60.

  FIG. 31 is an enlarged perspective view showing the paper feed cassette 41. A sheet feeding cassette 41 as a sheet placing device has a bottom plate 413 that functions as a leading-end placement surface among the entire placement surface on which a recording sheet (not shown) is placed. Also, a first side fence 411 and a second side fence 412 which are arranged so as to slide on the surface of the bottom plate 413 in the direction perpendicular to the conveyance direction (the direction of arrow B in the figure), inside the sheet cassette 41 for recording sheets (not shown). It also has an end fence 414 for restricting the tip position. A one-dot chain line labeled L2 in the drawing indicates a center line in the conveyance orthogonal direction of the paper feed cassette 41, which is the center line (L1) of the manual feed tray or the photoconductor in the conveyance orthogonal direction. It extends to the same position as the center line in the rotation axis direction.

  Although not shown in the figure, below the bottom plate 413, similarly to the sheet alignment device of the manual feed tray (60), a drive limiting mechanism, a first rack gear, a second rack gear, a connection pinion gear, a drive motor, a timing belt A home position sensor, a rotation detection sensor, a paper detection sensor, and the like are provided. The first side fence 411 and the second side fence 412 adjust the position of the recording sheet placed between the fences to the position of the center line L2 on the same principle as the sheet alignment apparatus for the manual feed tray (60). Move to slide. Note that the drive motor and various sensors mounted on the paper feed cassette 41 have electrical contacts with the control unit in the housing of the image forming unit when the paper feed cassette 41 is set at a predetermined position of the image forming unit. It is supposed to be connected.

  As shown in FIG. 2, the paper feed roller 42 is in contact with the bundle of recording sheets stored in the paper feed cassette 41. The paper feed roller 42 is supported not in the paper feed cassette 41 but in the housing of the image forming unit 4. When the operator presses the paper replenishment button on the operation display unit in a state where the paper feed cassette 41 is set in the housing of the image forming unit 4, the control unit (400) controls the paper feed roller lifting motor in the housing. Drive in reverse until Thereby, in each of the two paper feed cassettes 41, the paper feed roller 42 is largely separated from the cassette. In addition, the control unit drives the drive motors individually mounted on the two paper feed cassettes 41 in reverse to move the side fences in the paper feed cassettes 41 to the home positions. The operator who has pulled out the paper cassette 41 in this state from the housing of the image forming unit 4 sets a bundle of recording sheets on the bottom plate (413) of the paper cassette 41, and then puts the paper cassette 41 into the housing. return. Then, the in-cassette sheet alignment button in the operation display unit is pressed. Then, the control unit (400) starts normal rotation driving of the drive motor of the paper feed cassette 41, and performs processing similar to the alignment and counting processing in the manual feed tray (60). As a result, the bundle of recording sheets set in the paper feed cassette 41 is aligned with the position of the center line L2.

  Instead of automatically slidably moving the two side fences in the conveyance orthogonal direction by driving the drive motor to align the recording sheet in the conveyance orthogonal direction, the following alignment is performed. Also good. In other words, the end fence 414 in which the end fence 414 is slidable in the recording sheet conveyance direction (the direction of arrow E and the opposite direction) is configured similarly to the side fence of the paper feed cassette 41 of the copier according to the embodiment. It is driven by. While the end fence 414 brought into contact with the rear end of the recording sheet placed on the cassette is slid toward the front end side, the recording sheet is slid toward the front end side of the cassette. Then, the drive transmission to the end fence 414 is turned off at the moment when the leading edge of the recording sheet abuts against the leading edge side wall of the cassette, thereby aligning the recording sheet with the abutting position with the leading edge side wall. In this case, the bottom plate of the paper feed cassette 41 is refracted so that a refracting portion is formed in the central region of the entire area in the direction perpendicular to the conveyance direction of the recording sheet, and the end fence 414 is brought into contact with the refracting portion of the recording sheet. It is desirable to do so.

  In FIG. 4 described above, the document tray 200 as a sheet placing device of the ADF 2 includes a sheet alignment device having the same configuration as the manual feed tray (60). The sheet alignment apparatus includes a first side fence 211 and a second side fence 212 that are slidable in a conveyance orthogonal direction (a direction orthogonal to the drawing surface) on a tray upper surface 200a as a sheet placement surface. Have. Further, similarly to the manual feed tray (60), a first rack gear 213, a second rack gear 214, a connection pinion gear 215, a drive limiting mechanism 216, a drive motor 217, and the like are provided for sliding the side fences. Then, the first side fence 211 and the second side fence 212 are slid toward the center line in the conveyance orthogonal direction on the tray upper surface 200a by the same principle as that of the sheet alignment apparatus for the manual feed tray (60). The placed original sheet P is aligned with the center line.

  In the AFD 2, the paper feed roller 202 for feeding the original sheet P from the upper surface 200a of the tray is largely separated from the upper surface 200a of the tray, and the two side fences on the upper surface 200a of the tray are respectively positioned at the home positions. Waiting for instructions from the worker. When the copy start button is pressed by an operator who has set the document sheet P on the tray upper surface 200a, first, the two side fences are slid to align the document sheet P with the center line. Then, the feeding roller 202 is lowered and brought into contact with the document sheet P, and then the feeding of the document sheet P is started.

  In the copying machine according to the embodiment, a sheet alignment device similar to the manual feed tray (60) is also mounted on the relay tray 209b as a sheet placing device in the ADF2. The ADF 2 normally retracts a relay first side fence and a relay second side fence (not shown) that are slidably movable in the conveyance orthogonal direction on the relay tray 209b to the home position. Then, when the original sheet P that has passed the second contact glass 301 and the image on one side is read is turned upside down and passed through the second contact glass 301 again, the following processing is performed. That is, first, the posture of the switching claw is changed so that the free end side of the switching claw is lowered from the illustrated state, and then the two rollers of the relay roller pair 210 are rotated forward for a predetermined time. As a result, after reading, the document sheet P after passing through the conveyance nip of the second conveyance roller pair 206 is fed onto the relay tray 209b. Next, with the rotational driving of the relay roller pair 210 stopped, the upper roller of the two rollers of the relay roller pair 210 is moved upward and separated from the lower roller. As a result, the original sheet P that has been sandwiched between the conveyance nips of the relay roller pair 210 is made free. In this state, the slide movement toward the center line of the relay first side fence and the relay second side fence (not shown) on the relay tray 209b is started, and the document sheet P on the relay tray 209b is brought to the position of the center line. Align. Thereafter, the upper roller of the relay roller pair 210 is moved down to the position where the conveyance nip is formed, and then the reverse rotation of the relay roller pair 210 is started, so that the original sheet P is retransmitted.

  In the copier according to the embodiment, a sheet alignment device similar to the manual feed tray 60 is also mounted on the relay tray 88 as a sheet placing device of the reversing conveyance device 89. The relay tray 88 normally retracts a relay first side fence and a relay second side fence (not shown) disposed so as to be slidable in the conveyance orthogonal direction on its sheet placement surface to the home position. Yes. Further, the paper feed roller 42 is retracted to a position that is largely separated from the sheet placement surface of the relay tray 88. In the duplex printing mode, when all the recording sheets 6 that have been printed on one side are stored in the relay tray 88, the relay tray 88 points the relay first side fence and the relay second side fence toward the center line in the conveyance orthogonal direction. The recording sheet 6 stored in the relay tray 88 is aligned with the center line. Thereafter, the sheet feeding roller 42 is moved downward to come into contact with the recording sheet 6 in the relay tray 88, and then the sheet feeding roller 42 is driven to rotate to record the recording sheet from the relay tray 88 toward the registration roller pair 45. By re-sending the recording sheet 6 in the relay tray 88 that starts resending 6 after the positioning, the occurrence of jamming and skew conveyance can be suppressed.

  In the copier according to the embodiment, a sheet alignment device similar to the manual feed tray 60 is also mounted on the paper discharge tray 80 as a sheet placing device in the image forming unit 4. The sheet discharge tray 80 normally has a sheet discharge first side fence and a sheet discharge second side fence (not shown) arranged so as to be slidable in the conveyance orthogonal direction on the sheet placement surface of the sheet discharge tray 80 at their home positions. I'm evacuating. When the continuous print job by the image forming unit 4 is completed and all the recording sheets 6 in the continuous print are stacked on the discharge tray 80, the discharge first side fence and the discharge second side fence are moved in the conveyance orthogonal direction. The recording sheet 6 stacked on the paper discharge tray 80 is aligned with the position of the center line by sliding it toward the center line.

  Note that a post-processing device can be connected to the paper discharge tray 80. The post-processing device performs at least one of the processes listed below. That is, a stapling process for binding the recording sheet P on which the image is formed by the image forming unit 4, a sorting process for sorting the recording sheet P on which the image is formed for each destination, aligning the sheet leading edge, and correcting the skew of the sheet Alignment processing, sorting processing for rearranging a plurality of document sheets P in page order, and the like. It is possible to mount the sheet alignment apparatus according to the present invention on a post-processing apparatus that performs such processing. In the stapling process, a plurality of recording sheets 6 before binding may be aligned, or a plurality of binding bundles after binding a plurality of recording sheets 6 may be overlapped, and then the binding positions may be aligned. You may make it perform. In the former case, a plurality of recording sheets 6 are bound after being aligned so that they are not misaligned, so that a binding bundle without sheet misalignment can be obtained. In the latter case, a plurality of binding bundles can be stacked without deviation.

  As the manual feed tray 60, the following modified example in which the embodiment is modified may be used. The manual feed tray 60 includes a drive transmission mechanism in which a driven drive transmission member 616d and a drive drive transmission member 616a are integrally formed in a non-slidable manner instead of the drive restriction mechanism 616 shown in FIG. In such a configuration, even when the load applied to the driven drive transmission member 616d exceeds a predetermined threshold, the transmission of the driving force from the driving drive transmission member 616a to the driven drive transmission member 616d cannot be cut off. FIG. 32 is a plan view showing the first side fence 611 and the second side fence 612 and the recording sheet 6 in the manual feed tray (60) according to the modification. The first side fence 611 has a two-sheet structure including a base fence 611b and a floating fence 611a arranged in the direction perpendicular to the conveyance. The floating fence 611a is positioned closer to the center line (L1) than the base fence 611b, and is held by the base fence 611b so as to move within a certain range in the conveyance orthogonal direction. Between the floating fence 611a and the base fence 611b, the 1st pressure detection sensor 68 which detects the pressure added to the surface of the floating fence 611a from the centerline (L1) side is arrange | positioned. By making the first pressure detection sensor 68 detect the pressure applied to the surface of the floating fence 611a on the back side through the floating fence 611a, not the pressure applied to the local position on the surface of the floating fence 611a, The pressure applied to the entire surface can be detected. The second side fence 612 also detects the pressure applied to the entire surface of the floating fence 612a by the second pressure detection sensor 69 on the back side of the floating fence 612a.

  When the alignment and pulse counting process (S7 in FIG. 12) is started by the control unit (400), the first side fence 611 and the second side fence 612 are slid from the home position toward the center line (L1), respectively. To start. At this time, the distance between the first side fence 611 and the second side fence 612 is larger than the dimension in the conveyance orthogonal direction of the recording sheet 6 placed therebetween. In this state, the recording sheet 6 can freely move in the space between the fences in the conveyance orthogonal direction. For this reason, even if the two side fences both come into contact with the recording sheet 6, they smoothly slide while pressing the recording sheet 6 toward the center line (L1). In the process, when the recording sheet 6 comes into contact with the floating fence 611a of the first side fence 611, the pressure detected by the first pressure detection sensor 68 slightly increases, but does not increase significantly. The same applies to the case where the recording sheet 6 comes into contact with the floating fence 612a of the second side fence 612, and the pressure increase detected by the second pressure detection sensor 69 by the contact is slight.

  Thereafter, the two side fences move to a position where the recording sheet 6 is sandwiched between them. At this time, since the two side fences are pressed against each other via the recording sheet 6, the pressure detected by the first pressure detection sensor 68 and the pressure detected by the second pressure detection sensor 69 are Both exceed a predetermined threshold. When the pressure detected by the first pressure detection sensor 68 exceeds the threshold value and the pressure detected by the second pressure detection sensor 69 also exceeds the threshold value, the control unit (400) immediately drives the drive motor 617 to rotate forward. Stop. Thereby, the sliding movement of the side fences is stopped at a position where the distance between the first side fence 611 and the second side fence 612 is substantially the same as the dimension of the recording sheet 6 in the conveyance orthogonal direction. Thus, by stopping the side fence at an appropriate position, the recording sheet 6 can be reliably corrected to a straight posture along the conveyance direction. In addition, the recording sheet 6 is hardly bent due to the distance between the fences being narrower than the sheet width dimension. Therefore, the occurrence of jam and skew of the recording sheet 6 can be suppressed as compared with the conventional case.

  In addition, as the pressure detection sensors 68 and 69, it is preferable to use a sensor that changes the input value for pressure conversion according to the degree of deformation of the pressure detection unit.

  As described above, in the copying machine according to the embodiment, the position of the bottom plate and the position that is disposed between the first side fence 611 and the second side fence 612 and contacts the surface of the bottom plate 610 by swinging about the swing shaft 617. The recording sheet 6 is freely reciprocated between a position away from the surface of the substrate 610 and placed on the recording sheet 6 placed on the surface of the bottom plate 610. The recording sheet 6 is pressed against the surface of the bottom plate 610 by its own weight. A holding member 604 is provided. Then, the surface position displacement detecting means including the slit plate 692, the slit sensor 693, the control unit 400, and the like is configured so that the surface position displacement due to the bending of the recording sheet 6 is detected by the displacement of the pressing member 604 in the swinging direction. doing. In such a configuration, the positional displacement of the surface due to the deflection of the recording sheet 6 on the surface of the bottom plate 610 can be detected without providing a sensor at a position opposed to the surface of the bottom plate 610, so that the degree of freedom in layout is improved. be able to.

  In the copier according to the embodiment, the recording member 604 is provided with a taper surface at a portion facing the surface of the bottom plate 610 that is tapered away from the surface of the bottom plate 610 as it approaches the first side fence 611 from the center line L1. One taper portion 604b is provided. As the taper surface is rubbed against the upper edge of the sheet bundle approaching the pressing member 604 while being pushed by the first side fence 611 that is moved by the drive of the drive motor 617, the swing shaft 617 is centered. Thus, the pressing member 604 is moved away from the surface of the bottom plate 610 to ride on the sheet bundle. In such a configuration, the sheet bundle pressed toward the center line L1 by the first side fence 611 can be moved to the center line L1 and aligned without being caught by the pressing member 604.

  In the copying machine according to the embodiment, the driving force of the drive motor 617 is transmitted to the first side fence 611 and the second side fence 612 in opposite directions along the conveyance orthogonal direction. A drive transmission mechanism is configured. Moreover, the movement stop means which comprises the drive restriction mechanism 616 etc. is comprised so that the 1st side fence 611 and the 2nd side fence 612 may be stopped at the same timing mutually. In addition to the first taper surface formed by the first taper portion 604b, a second taper portion 604c is provided that moves away from the bottom plate 610 as the second side fence 612 is approached. Further, as the second tapered surface is rubbed against the upper edge of the sheet bundle that approaches the pressing member 604 while being pressed by the second side fence 612 that is moved by the driving force of the driving motor 617, the second taper surface swings. The pressing member 604 is moved in a direction away from the bottom plate 610 around the shaft 697 so as to ride on the sheet bundle. In this configuration, as described above, the recording sheets on the tray can be aligned based on the center. Further, the sheet bundle can be aligned without being caught on the pressing member 604.

  In the copying machine according to the embodiment, the control unit 400 is caused to function as a drive stop unit that stops the driving of the drive motor 617 when the control unit 400 serving as the determination unit determines that the recording sheet 6 is bent. ing. In such a configuration, when the bending of the recording sheet 6 is detected, the drive motor 617 is quickly stopped, so that wasteful energy consumption can be suppressed.

Further, in the copying machine according to the embodiment, based on the comparison of the detection result by the surface position displacement detecting means comprising a slit sensor 693, etc., and serving a predetermined threshold h _2, it determines the presence or absence of deflection of the recording sheet 6 The control unit 400 serving as a determination unit is configured to execute the process. In such a configuration, it is possible to avoid erroneously detecting the phenomenon in which the pressing member 604 is mounted on the sheet bundle being aligned as shown in FIG.

  In the copying machine according to the embodiment, the distance between the first side fence 611 and the second side fence 612 in the conveyance orthogonal direction is smaller than the short side dimension of the minimum size sheet defined as a design standard. When a distance closer than the limit approach distance is reached, a feeding unit composed of a combination of the manual sheet feeding roller 601 and the control unit 400 is configured so as to perform processing that does not start feeding the recording sheet 6 from the tray. . In such a configuration, as shown in FIG. 30, the occurrence of severe wrinkles and tears caused by feeding out the recording sheet 6 that is bent with a relatively small amount of bending is suppressed, or the recording sheet protrudes outside the recording sheet smaller than the minimum size. It is possible to prevent reverse transfer of the image portion to the secondary transfer roller 33.

  In the copying machine according to the embodiment, the sheet receiving surface which is the rear end side mounting surface for mounting the rear end side in the conveyance direction of the recording sheet 6 out of the entire mounting surface of the manual feed tray 60. 621 is configured as follows. In other words, the recording sheet 6 is configured to refract at a predetermined refraction angle θ with respect to the bottom plate 610 surface, which is a front end side mounting surface for mounting the front end side of the recording sheet 6. Moreover, the 1st side fence 611 and the 2nd side fence 612 are comprised as follows. That is, the recording sheet 6 placed on the placement surface is moved along the conveyance orthogonal direction at a position where it can contact at least a refracting portion refracted along the refraction angle θ. ing. Further, the pressing member 604 is configured as follows. That is, at least the refracting portion of the entire recording sheet 6 placed on the placement surface is pressed toward the placement surface. With such a configuration, the recording sheet 6 can be reliably refracted by pressing with the pressing member 604, and the recording sheet 6 can be given a waist.

2: ADF (part of image reading device)
3: Scanner (part of the image reader)
4: Image forming unit (part of image forming apparatus)
5: Paper feed unit (part of image forming apparatus)
6: Recording sheet (sheet member)
60: Manual feed tray (sheet placing device)
66: Paper detection sensor (sheet detection means)
80: Paper discharge tray (sheet placement device)
88: Relay tray (sheet placement device)
200: Document tray (sheet placing device)
209b: Relay tray (sheet placing device)
400: Control unit (determination means, drive stop means, part of surface position displacement detection means, part of delivery means)
601: Manual paper feed roller (part of feeding means)
604: Holding member 604a: Arm part (main body part)
604b: 1st taper part 604c: 2nd taper part 610: Bottom plate (mounting surface, tip side mounting surface)
611: First side fence (first regulating member)
612: Second side fence (second regulating member)
613: First rack gear (a part of drive transmission means and movement stop means)
614: Second rack gear (part of drive transmission means and movement stop means)
615: Connection pinion gear (part of drive transmission means and movement stop means)
616: Drive restriction mechanism (part of drive transmission means and movement stop means)
617: Drive motor (drive source)
618: Timing belt (part of drive transmission means and movement stop means)
619: Rotation detection sensor (motion detection means)
621: Sheet receiving surface (placement surface, rear end side placement surface)
650: Home position sensor 692: Slit plate (part of surface position displacement detection means)
693: Slit sensor (part of surface position displacement detection means)
B: Transport orthogonal direction C: Transport direction θ: Refraction angle P: Document sheet (sheet member)

JP-A-7-267474

Claims (8)

A mounting surface for mounting a sheet-like sheet member;
A direction along the placement surface and arranged on the placement surface so as to move in a conveyance orthogonal direction which is a direction perpendicular to the sheet conveyance direction on the placement surface. A first regulating member that regulates the position of the one end by abutting against one end of the sheet member placed on the conveyance orthogonal direction;
A second regulating member that regulates the position of the other end by contacting the other end of the sheet member in the conveyance orthogonal direction;
Drive transmission for transmitting a driving force exerted by a driving source to at least the first regulating member of the first regulating member and the second regulating member and moving the first regulating member in the conveyance orthogonal direction. Means,
A delivery means for delivering the sheet member placed on the placement surface from the placement surface, and
While restricting the position of the one end by the first restricting member and restricting the position of the other end by the second restricting member, the sheet member placed on the placement surface in the conveyance orthogonal direction In the sheet placing device for adjusting the position to a predetermined position,
Between the position which is arrange | positioned between the said 1st control member and the said 2nd control member, and contacts the said mounting surface by the rocking | fluctuation centering on the rocking | fluctuation axis, and the position spaced apart from the said mounting surface. A pressing member that freely reciprocates and presses the sheet member toward the mounting surface by its own weight in a state of being placed on the sheet member mounted on the mounting surface;
A tapered surface that is disposed at a portion of the pressing member facing the mounting surface, and that moves away from the mounting surface as approaching the first regulating member from a center of the mounting surface in the direction perpendicular to the conveyance direction;
Based on the fact that a force to prevent the movement of the first regulating member that is moving toward the sheet member on the placement surface by a driving force of the driving source exceeds a predetermined threshold. Movement stop means for stopping the movement of the first regulating member;
A surface position displacement detecting means for detecting a position displacement of the surface due to the deflection of the sheet member placed on the placing surface by the displacement in the swinging direction of the pressing member ;
On the basis of the detection result by the surface position displacement detection means, setting the judging means for judging whether the deflection for the placed sheet member on the mounting surface,
Only when it is determined by the determination means that there is no deflection, the feed means is configured to perform the process of starting the feeding of the sheet member from the placement surface ,
And as the taper surface is rubbed against the upper edge of a bundle of a plurality of sheet members approaching the pressing member while being pressed by the first regulating member that is moved by driving of the driving source, A sheet placing apparatus characterized in that the pressing member is moved in a direction away from the placement surface about the swinging shaft so as to ride on the bundle . In the sheet placing apparatus according to claim 1 ,
The second restricting member is slidably arranged on the mounting surface, and
Configuring the drive transmission mechanism to transmit the driving force of the driving source to the first restricting member and the second restricting member in opposite directions along the conveyance orthogonal direction;
Configuring the movement stop means to stop the first restricting member and the second restricting member at the same timing;
In addition to the first tapered surface as the tapered surface, a second tapered surface that moves away from the mounting surface as it approaches the second regulating member from the center of the mounting surface in the direction perpendicular to the conveying direction to the pressing member. Provided,
As the second tapered surface is rubbed against the upper edge of a bundle of a plurality of sheet members approaching the pressing member while being pressed by the second regulating member that is moved by driving of the driving source. The sheet placing device according to claim 1, wherein the pressing member is moved in a direction away from the placement surface about the swinging shaft so as to ride on the bundle. In the sheet placing apparatus according to claim 1 or 2 ,
A sheet placement device comprising drive stop means for stopping drive of the drive source when the determination means determines that there is bending. In the sheet placing apparatus according to claim 3 ,
The sheet mounting characterized in that the determination unit is configured to execute a process of determining whether or not the sheet member is bent based on a comparison between a detection result by the surface position displacement detection unit and a predetermined threshold value. Device. The sheet placing apparatus according to claim 4 , wherein
When the separation distance in the conveyance orthogonal direction between the first restriction member and the second restriction member is closer than a predetermined limit approach distance smaller than the short side dimension of the minimum size sheet defined as a design standard The sheet placing device is characterized in that the feeding means is configured to perform a process that does not start feeding the sheet member from the placement surface. The sheet placing apparatus according to any one of claims 1 to 5 ,
The rear end side mounting surface for mounting the rear end side in the conveying direction of the sheet member out of the entire mounting surface is the front end side mounting surface for mounting the front end side of the sheet member. Is provided to take a posture of refracting with a predetermined refraction angle,
At a position where the first restricting member and the second restricting member can come into contact with at least a refracting portion that is refracted along the refraction angle in the entire region of the sheet member placed on the placement surface. , Arranged to be movable along the conveyance orthogonal direction,
In addition, the sheet placement is characterized in that the pressing member presses at least the refracting portion toward the placement surface among the entire area of the sheet member placed on the placement surface. apparatus. Image recording means for recording an image on the surface of a recording sheet as a sheet member;
A sheet placement device for adjusting a position of a recording sheet on a placement surface on which a recording sheet to be sent out toward the image recording means or a recording sheet after passing through the image recording means to a predetermined position In an image forming apparatus comprising:
Examples sheet mounting apparatus, the image forming apparatus characterized by using any of the sheet mounting apparatus of claims 1 to 6. Reading means for reading an image recorded on a document sheet;
A sheet placement device that adjusts the position of the recording sheet on the placement surface on which the recording sheet to be sent out toward the reading means or the recording sheet after passing through the reading means to a predetermined position; In the image reading apparatus provided,
Examples sheet mounting apparatus, an image reading apparatus characterized by using one of the sheet mounting apparatus of claims 1 to 6.

Images