JP2000318246A - Printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing apparatus with a delivery tray whereby papers of any kind and with any images printed can be registered well. SOLUTION: The printing apparatus has a delivery tray 6 where printed papers are piled. The delivery tray 6 is provided with a side fence 29 for regulating each side edge of the papers. An air flow generation device is set to the side fence 29 for sending the air to between papers piled on the delivery tray 6. After the papers are piled on the delivery tray 6, the air flow generation device sends the air to between the piled papers on the delivery tray 6 thereby registering the piled papers on the delivery tray 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus having a mechanism for aligning sheets on an output tray.

[0002]

2. Description of the Related Art Conventionally, various mechanisms have been proposed for aligning sheets in a discharge tray on which printed sheets are stacked. Japanese Unexamined Patent Application Publication No. 8-2 regarding earlier application by the present applicant
Japanese Patent Application Laid-Open No. 90859 discloses that the interval between the side fences provided on the paper discharge tray and regulating the respective side edges of the paper is set to be slightly smaller than the width of the paper, and the paper is brought into contact with the side fence. Japanese Patent Application Laid-Open No. 10-1254 discloses a technique for aligning sheets by lowering the printing surface of the sheet into a concave shape and dropping the sheet. On the other hand, there is described a technique of performing paper jogging by performing a jogger operation. In Japanese Patent Application No. 10-329439 filed by the present applicant, air feeding means is provided on a side fence to prevent the paper from being dropped. There has been proposed a technique in which air is blown upward toward the side edge of a sheet, and the printing surface of the sheet is dropped in a concave shape.

[0003]

Although the above three techniques are certainly effective in improving the paper alignment, it is difficult to print an image having many solid portions on a weak paper such as a new paper. In such a case, there is a problem that it is not possible to perform a sufficient discharge alignment. Specifically, when printing is performed on a sheet of paper having weak stiffness such as a paper change, the technique disclosed in Japanese Patent Application Laid-Open No. Hei 8-29059 and the technique proposed in Japanese Patent Application No. Hei 10-329439 will cause the paper to be solid. The ink side becomes heavier due to the ink, and the print surface of the paper expands due to the moisture of the ink in the portion with a large solid portion. Therefore, when the solid portion is offset to one side of the paper, the portion is convex. For example, the central portion of the paper does not have a uniform concave shape depending on the position of the solid portion, and the paper is dropped from the side having a large amount of the solid portion, thereby deteriorating the alignment of the paper. According to the technology described in JP-A-1254, when an image having a lot of solid portions is printed on a reprinted paper, the weight of the paper increases due to the ink and the stiffness is further reduced by the moisture of the ink. The effect of aligning the paper will be broken also pressed part by pressing the side edges of the paper there is a problem of a decrease by.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing apparatus provided with a paper discharge tray capable of performing good paper alignment even when printing any image on any paper.

[0005]

According to a first aspect of the present invention, there is provided a sheet discharging tray for loading printed sheets, and the sheet discharging tray is provided at each side edge of the sheet. In a printing apparatus having side fences for respectively controlling air flow, an air flow generating means for feeding air between the sheets stacked on the paper discharge tray is provided on the side fence, and the paper flow to the paper discharge tray is provided. After the stacking is completed, air is sent between the sheets stacked on the sheet discharge tray by the air flow generating means, and the sheets stacked on the sheet discharge tray are aligned.

According to a second aspect of the present invention, in the printing apparatus of the first aspect, there is provided a detecting means for detecting a size of the sheet, and the discharge tray is configured to detect at least one of the side fences by the sheet. Wherein the side fence displacement means displaces the distance between the fences in accordance with the width of the sheet detected by the detection means.

According to a third aspect of the present invention, in the printing apparatus of the second aspect, the side fence displacement means makes a width between the side fences substantially equal to a width of a sheet.

According to a fourth aspect of the present invention, in the printing apparatus according to the second aspect, the side fence displacement means adjusts the width between the side fences until the stacking of the sheets on the discharge tray is completed. The width of the sheet is smaller than the width of the sheet, and is substantially the same as the width of the sheet after the stacking of the sheets on the discharge tray.

According to a fifth aspect of the present invention, in the printing apparatus according to the fourth aspect, the side fence displacement means is configured such that each of the side fences smaller than the width of the sheet after the stacking of the sheet on the sheet discharge tray is completed. Before the width between the fences is made substantially the same as the width of the paper, the distance between the side fences is made at least once larger than the width of the paper.

The invention according to claim 6 is the invention according to claim 4 or 5.
In the printing apparatus described in the above, after the side fence displacement means makes the side fence substantially the same as the width of the sheet,
The air flow generating means is stopped.

[0011] The invention according to claim 7 is the invention according to claims 1 to 6.
The printing device according to any one of the above, wherein a rectifying member for rectifying the air flow generated by the air flow generating means is provided on the side fence.

[0012] The invention according to claim 8 is the invention according to claims 1 to 7.
The printing apparatus according to any one of the above, further comprising a detecting unit for detecting a size of the sheet, a plurality of the air flow generating units provided in a length direction of the sheet, and a length of the sheet detected by the detecting unit. The air flow generating means to be operated among the plurality of air flow generating means is determined accordingly.

[0013]

1 shows a stencil printing apparatus as a printing apparatus to which the present invention is applied. The stencil printing machine 1 is a stencil printing machine 1
Printing drum 2 as a plate cylinder arranged at the upper center of the main body
And a press roller 3 as a pressing means for pressing a printing sheet (hereinafter, referred to as “sheet”) between the printing drum 2 and the printing roller 2, and a plate making means for making a stencil sheet as a master. A master making device 107, a master transporting means (not shown) provided in the housing of the plate making device 107 and transporting a master made by the plate making toward the printing drum 2, and a sheet facing the printing drum 2 and the press roller 3 A paper feed tray 5 loaded with new paper to be supplied toward a printing position 4 where printing is to be performed, a paper discharge tray 6 serving as a paper discharge tray for loading paper printed at the printing position 4, A plate discharging device 8 serving as a plate discharging device for removing the stencil sheet that has been completed from the printing drum 2 and storing the image, and reading an image to be printed and sending the read image data to the plate making device 107. Mainly has a 9.

As the stencil paper, a laminated structure of a thin film made of PET and a base member made of Japanese paper is used. And so on.
A large number of sheets are placed on the sheet supply table 5, are separated and conveyed one by one, are printed on a surface facing upward during the conveyance, and are sent to the sheet discharge tray 6. Paper feed table 5
Some transporting means are involved before the paper is conveyed to the paper discharge tray 6 from among the paper feed rollers 10 and 10.
There are a feed roller 11 as a registration roller, a paper discharge suction unit 12, and the like. The paper feed roller 10 is swingably supported by a vertically movable drive shaft 10a. As the paper feed proceeds, the position of the paper feed roller 10 is lowered, and a predetermined amount is detected when a sensor (not shown) detects the position. The paper feed table 5 is raised only so that the top sheet is always controlled to a height suitable for paper feeding. The paper feed table 5 has side fences 26 and 26 and regulates both side edges of the paper placed on the paper feed table 5.

An upper guide plate 13 and a lower guide plate 14 are disposed facing each other at a position on the near side from the downstream side of the paper feed roller 10 to the printing position 4 via the feed roller 11 in the paper transport direction. ing. The feed roller 11 is
Feed roller (upper) 11 arranged to be in opposing contact
a, and a feed roller (lower) 11b. The sheet is separated by the sheet feed roller 10 and sent out, and is fed between the upper and lower guide plates 13 and 14 toward the printing position 4. . The sheet that has exited the printing position 4 is sent out to the paper discharge suction unit 12, and the paper discharge suction unit 12
The paper is further sent to the paper discharge tray 6. Discharge suction unit 1
2 has a transport belt 17 and a transport suction fan 18 spanned between a driving roller 15 and a driven roller 16, and while the transport suction fan 18 sucks printed paper on the transport belt 17, The paper is conveyed toward the paper discharge tray 6 by the conveyance belt 17.

The printing drum 2 has a stencil retaining device 19 as a clamper for clamping the leading end of the stencil sheet which is heat-sensitive on the peripheral surface. In the printing drum 2, although not shown, an ink supply pipe for supplying ink to the inner peripheral surface thereof, an ink supply roller, a doctor roller, and a wedge-shaped ink reservoir formed by the ink supply roller and the doctor roller. A well-known ink supply device composed of the above-described components is provided.

The press roller 3 is supported by a support arm 21 that supports a support shaft 20 so as to be able to freely move toward and away from the printing drum 2. One end of the support arm 21 is rotatably supported on a casing (not shown) of the stencil printing machine 1 by a shaft 22. A portion of the support arm 21 opposite to the shaft 22 with respect to the support shaft 20 is urged toward the printing drum 2 by a tension spring 23 whose one end is locked to a casing of the stencil printing machine 1. A cam 24 is engaged with the other end of the support arm 21 from above, and the press roller 3 is separated from the printing drum 2 by engaging the long diameter portion of the cam 24 with the support arm 21. .

Although not shown, the stencil discharging device 8 includes a stencil box for storing used stencil paper, an opening / closing plate for opening and closing the stencil box, and a standby position and an operating position in contact with the printing drum 2. A known method including a swingable peeling roller capable of swinging, a peeling roller disposed opposite to the swinging peeling roller, and a guide for forming a plate discharge path for guiding a used stencil sheet to a plate discharge box between the open / close plate and the open / close plate. It is a structure of. In the vicinity of the peripheral surface of the printing drum 2, an air knife 2 that peels off the leading end when the paper printed at the printing position 4 is wound around the printing drum 2 due to the viscosity of the ink.
5 are provided. The air knife 25 forcibly blows air between the leading edge of the sheet and the peripheral surface of the printing drum 2.

The image reading section 9 is located at the top of the stencil printing apparatus 1. Although not shown, the image reading unit 9 includes a document tray for placing documents, a document transport roller for separating and transporting the documents one by one, a document separating roller, a contact glass on which the document to be read is placed, and a contact for the document. It has a well-known configuration including an endless and wide transport belt for feeding over glass, a reading sensor device provided below the contact glass, and the like. The stencil printing apparatus 1 has storage means (not shown) for storing the image data read by the image reading section 9 and outputting the image data to the stencil making apparatus 7 in a timely manner.

Although not shown, the stencil making apparatus 107 has a support means for supporting a master roll in which a stencil sheet is formed into a roll, a thermal head provided on the film surface side of the stencil sheet, and a thermal head opposed to the thermal head. This is a known configuration including a platen roller disposed on the base member side of the stencil sheet, a cutter for cutting the stencil sheet that has been made, and the like.

An operation panel (not shown) for performing various operations is provided outside the stencil printing apparatus 1. The operation panel includes a plate making start button for instructing execution of plate making, a print start button for instructing execution of printing, and a stencil printing machine 1 provided on a normal operation panel.
And a numeric keypad for instructing the number of prints, the number of copies, and the like.

As shown in FIG. 1, FIG. 2, FIG. 3, or FIG. 4, the paper discharge tray 6 includes an end plate 27 for receiving the leading edge of the paper conveyed from the print position 4 through the paper discharge suction unit 12, Paper loading surface 3 for loading paper
3 and a side fence 29 for regulating each side edge of the sheet. The paper discharge tray 6 is detachable from the stencil printing apparatus 1 main body. The end plate 27 is in a direction parallel to the direction in which the sheet is discharged from the sheet stacking surface 33 and is displaceable in the A direction and the B direction which are the length directions of the sheet. 33, the end plate 2
7 is a direction perpendicular to the direction in which the sheet is displaced, and is displaceable in the direction C which is the width direction of the sheet.

A notch 42 extending in the AB direction is formed at the center in the C direction on the upper surface plate 28 'of the mounting table 28 having the sheet mounting surface 33. A guide shaft 43 is provided in the direction. The end plate 27 is slidable on the guide shaft 43 by a slider 106 shown only in FIG. 2 integrated with the end plate 27, and is displaced in the AB direction. A notch 4 extending in the C direction is provided at each end in the C direction, that is, at each end corresponding to the side edge in the width direction of the sheet, in the top plate 28 '.
4 and 44 are formed, and guide shafts 45 and 45 are disposed in the notches 44 and 44 in the C direction. Each of the side fences 29 is slidable on the guide shaft 45 by a slider 103 shown only in FIG. 2 that is integral with the side fence 29. The side fences 29 are displaced in a direction C so as to approach or separate from each other.

As shown in FIG. 5, an end plate displacing means for displacing the end plate 27 in the AB direction is provided on the inside of the mounting table 28, that is, on the bottom plate 28 "below the top plate 28 '. Side fence displacement means for displacing the sheet in the direction C. The end plate displacement means displaces the end plate 27 in the direction AB in accordance with the size of the sheets stacked on the sheet discharge tray 6. A motor 5 fixedly mounted on the bottom plate 28 "having a gear shaft 50 for driving the gear shaft 50 to rotate.
1, a gear 52 driven to rotate by a gear shaft 50, and a gear 54 driven to rotate by a gear 52 about a shaft 53.
A drive pulley 55 that rotates integrally with a gear 54 provided on a shaft 53; a driven pulley 56; and an endless belt 57 wound around the drive pulley 55 and the driven pulley 56. One end of the endless belt 57 is engaged with the slider 106, and the end plate 27 is displaced in the AB direction as the drive pulley 55 rotates.

The side fence displacement means includes a motor 59 fixed to the bottom plate 28 ″ having a gear shaft 58 for driving the gear shaft 58, and a gear 61 driven to rotate about the shaft 60 by the gear shaft 58. A drive pulley 62 provided on a shaft 60, a driven pulley 64 rotating about a shaft 63,
A pinion 65 provided on the shaft 63 and integrally rotating with the driven pulley 64; an endless belt 66 wound around the driving pulley 62 and the driven pulley 64; and a rack 67 provided on the side fence 29 and engaged with the pinion 65, respectively. have. When the motor 59 drives the drive pulley 55 to rotate, the side fences 29 are simultaneously displaced in the direction C, and the side fences 29 are moved toward and away from each other.

In FIG. 5, reference numeral 68 denotes a reflection type sensor for detecting the position of the end plate 27 in a state in which the sheet can be discharged from the stencil printing machine 1, and reference numeral 70 denotes a reflection type sensor for detecting the position of the side fence 29. 4 shows a sensor. The downstream side of the side fence 29 in the direction A, that is, the side for receiving the paper from the stencil printing apparatus 1 main body is expanded, so that the paper can be smoothly received.

On the outer wall of the side fence 29,
Two air flow generators 111, 111 are provided in the AB direction. The air flow generator 111 is a device for sending air between the sheets stacked on the sheet discharge tray 6 and all have substantially the same configuration. The air flow generation device 111 has an air flow generation unit 112 and an air rectification unit 113. As shown in FIG. 6 or FIG. 7, a fan 119 as an airflow generating means that is rotationally driven by a drive source (not shown) is provided in a casing 115 of the airflow generating unit 112. By driving, side fence 2
9 generates an air flow toward the inner wall side. A fin 114 as a rectifying member for rectifying the air flow generated by the fan 119 is provided in a casing 116 of the air rectifying unit 113.
When the airflow generated by 19 passes through the air rectification unit 113, the airflow is made uniform in the height direction as shown by the arrow D, and is blown out in a direction parallel to the paper mounting surface 33.

As shown in FIG. 8 or FIG. 9, a honeycomb plate 117 can be used as the rectifying member. If the honeycomb plate 117 is used, rectified air can be sent not only in the vertical direction but also in the horizontal direction. Can be. When the honeycomb plate 117 is used as the rectifying member, as shown by reference numeral 118, a rectifying plate as a second rectifying member for sending the airflow generated by the fan 119 to the honeycomb plate 117 to some extent evenly. It is desirable to arrange. Although not shown, the current plate 118 has a slit formed in the vertical direction, and the distribution of air blocked by the current plate 118 and wrapping around the current plate 118 to reach the honeycomb plate 117, And the distribution of air passing through the honeycomb plate 117 and reaching the honeycomb plate 117 is made substantially uniform. As long as this function is achieved, the slits may be formed not in the vertical direction but in the horizontal direction and the oblique direction to form a plate, and holes may be formed instead of the slits.

The stencil printing apparatus 1 has a detecting means for detecting the size of a sheet. In the present embodiment, the detecting means uses a well-known mechanism for detecting the size of the paper placed on the paper feed table 5. When the paper can be used, a key for designating the size of the paper to be used on the operation panel may be used as the detection unit.

The present embodiment is configured as described above. As one operation for starting printing, a required number of prints is designated by a ten key. On the other hand, when a predetermined original is set on the original receiving tray and the plate making start button is turned on, the processing of the used stencil sheet remaining on the printing drum 2 in the previous printing process is performed as follows. When the printing drum 2 rotates and the stencil catching device 19 reaches the stripping position near the plate discharging device 8, the printing drum 2 stops and is operated by an opening / closing mechanism (not shown) of the stencil catching device 19. Is released. The used stencil sheet released by the release of the clamp at the leading end is peeled from the leading end by the swinging peeling roller displaced to the operating position, and is opened and closed by the rotation of the peeling roller and the printing drum 2. The sheet is discharged into a plate discharge box via a plate discharge path formed between the plate and the guide.

The printing drum 2 rotates clockwise while the used stencil sheet is taken into the plate discharging device 8,
When the used stencil sheet is rotated to a predetermined position where the stencil sheet is completely discharged, a sensor (not shown) detects the rotation, the opening / closing plate closes the stencil discharge box, and the oscillating peeling roller returns to the standby position.
The printing drum 2 further rotates, and the base paper locking device 19
When the sensor is located at the stencil supply position indicated by a two-dot chain line, a sensor (not shown) detects this and the rotation of the printing drum 2 is stopped, and the plate making device 107 starts feeding the stencil sheet which has been made into the printing drum 2. You will have to wait until you do.

In parallel with the plate discharging process, a well-known document reading process starts at the same time, the image data of the document is read by the reading sensor device, and the electric signal photoelectrically converted in the reading sensor device is converted into a stencil printing device. The data is input to an A / D (analog / digital) conversion board (not shown) provided in the main body of the stencil printing machine, and is stored in a storage unit (not shown) provided in the main body of the stencil printing apparatus 1. Simultaneously with the storage, a stencil making process and a subsequent stencil feeding process are started.

In the plate making device 107, a platen roller pressing the stencil paper against the thermal head rotates,
The stencil sheet is transported. On the stencil sheet being transported, a plurality of heating elements arranged in a line on the thermal head
According to the digital image signal of the original document which is temporarily stored in the storage means (not shown) and subjected to various processes by the plate-making substrate, each selectively generates heat according to the digital image signal, and the thermoplastic resin film of the stencil sheet is melt-punched. . The perforated stencil paper is
When the stencil sheet is conveyed toward the printing drum 2 by the master conveying means and reaches the stencil locking device 19 whose end is expanded, the stencil locking device 19 is closed and the stencil sheet is clamped. The printing drum 2 rotates, and the stencil sheet is gradually wound around the outer peripheral surface of the printing drum 2. At this time, since the long diameter portion of the cam 24 is in contact with the support arm 21 and the press roller 3 is separated from the printing drum 2, the stencil locking device 19 does not hinder the rotation of the drum 2. . The stencil sheet after the stencil making is cut into a predetermined length by a cutter.

In the plate attaching step, at a predetermined timing, the top one of the sheets stacked on the sheet supply table 5 is sent toward the feed roller 11 by the sheet supply roller 10, At 11 a predetermined timing synchronized with the rotation of the printing drum 2 is sent between the printing drum 2 and the press roller 3. The paper is pressed simultaneously against the plate-making unused stencil sheet newly mounted on the outer peripheral surface of the printing drum 2 and the press roller 3, and the printing ink is applied from the perforated portion of the plate-making unused stencil sheet onto the upper surface of the paper. The transfer is performed and printing is performed.

When the paper thus printed passes the printing position 4, the printing drum 2 is moved by the air knife 25.
Is peeled off from the stencil sheet mounted on the outer peripheral surface of the stencil sheet, is conveyed by the sheet discharge suction unit 12, and falls onto the sheet discharge tray 6, thereby completing the plate attaching process. Next, in a process similar to the plate attaching process, a printing process including a paper feeding, printing, and paper discharging process is repeatedly performed for the number of prints set by the numeric keypad. In the trial printing and printing processes, when the base paper locking device 19 faces the press roller 3, the press roller 3
Is designed to face the printing drum 2,
The stencil retaining device 19 does not contact the press roller 3.

As shown in FIG. 10, the side fence displacement means in the sheet discharge tray 6 displaces the side fence 29 in accordance with the size of the sheet detected by the detection means. The distance between them is set to S smaller than the width W of the sheets until the stacking of the sheets on the sheet discharge tray 6 is completed. The end plate 27 is also provided in accordance with the size of the sheet detected by the detecting unit.
The end plate displacement means is displaced and occupies a position suitable for receiving the leading edge of the sheet by detection by the sensor 68.

Since the end of the paper discharge tray 6 on the side of the end plate 6 is located lower than the end of the double-sided tray 7,
The paper discharged from the stencil printing machine 1 has a paper loading surface 3
3 or the paper already stacked on the paper output tray 6, and
9, the paper is stacked on the paper output tray 6 to some extent. In this case, for example, when an image having a lot of solid portions is printed on a weak paper such as a paper break, The paper is heavier with ink on the side with more solid parts, and the printed part of the paper expands due to the moisture of the ink on the parts with more solid parts. The central part of the paper does not become evenly concave depending on the position of the solid part due to the fact that the part is warped convexly, etc., it falls from the side with many solid parts, and the paper alignment can be sufficiently ensured Not.

When the stacking of the sheets on the sheet discharge tray 6 is completed, as shown in FIG.
Assuming that the distance between the side fences 29 is L, which is larger than W, the paper is released from the restraint by the side fences 29 and thus slightly spreads in the width direction. In this state, the fan 119 is driven to send air between the sheets stacked on the sheet discharge tray 6 as shown in FIG. As a result, an air layer is formed between the respective sheets, the overlapping sheets are separated from each other, and each sheet is in a floating state. The blowing of air promotes drying of the ink.

As shown in FIG. 13, the distance between the side fences 29 is set to be substantially the same as the width W of the sheet (hereinafter, this width is also indicated by "W") while the fan 119 is driven. Since an air layer is formed between the sheets, there is no friction between the sheets. Smoothly aligned. As shown in FIG. 14, while keeping the position of the side fence 29 in this state, the fan 119 is stopped, and the paper alignment process ends.

Although the embodiment has been described above, the stencil printing apparatus 1
The configuration of each of the above-described devices and the like and the arrangement state thereof are as follows.
This is merely an example, and other known devices and various arrangements may be used. For example, the stencil printing apparatus 1 is not limited to the above-described thermosensitive digital stencil making integrated type stencil printing apparatus, and the master may be discharged by a plate discharging device provided separately from the apparatus main body. The device 8 does not necessarily have to be provided in the device main body. The data for plate making may be data read by the document reading device as described above, or data created by a computer or the like. In addition, multi-color printing including full-color printing can be performed as a double-cylinder type in which two or more plate cylinders are arranged in parallel,
As printing paper, in addition to ordinary paper, thick paper, envelopes, and the like can be used.

Further, in the above embodiment, the case where the printing apparatus is a stencil printing apparatus has been described, but another type of printing apparatus can be used as the printing apparatus. As an example of another type of printing apparatus, a single plate making apparatus that performs plate making such that a master having two sides is not penetrated by a thermal head is used, and the plate is mounted on two plate cylinders arranged opposite to each other. A printing device to be wrapped around a cylinder may be used. Note that a printing apparatus that performs plate making to the extent that it does not penetrate the master with the front and back by the thermal head is disclosed in Japanese Patent No.
No. 790963.

In the embodiment, the side fence displacing means sets the width of the side fence 29 between the side fences 29 at the interval S after the stacking of the sheets on the discharge tray 6 is completed. The distance between the side fences 29 is set to L instead of L once.
In addition, a so-called jogger operation may be performed in which the sheet is displaced a plurality of times between W and L or W and L. According to the jogger operation, the alignment of sheets can be further improved. Further, the side fence displacement means may set the width between the side fences 29, which are S until the stacking of the sheets is completed, to simply W instead of L, or the width between the side fences, Even if it is always W, the paper can be aligned to some extent by the airflow from the fan.

In the embodiment, the fan is operated after the width between the side fences 29 becomes L, but the operation timing is before the width between the side fences 29 is set to L or when the width is set to L. Then, it may be simultaneous. Also,
In the embodiment, both the fans in the AB direction are operated. However, when the size of the sheet is small, only the fan on the downstream side in the B direction may be operated. The number of fans is not limited to two in the AB direction, but may be one, three or more. When a plurality of fans are provided, the fan that operates according to the size of paper may be determined. it can. A post-processing device such as a collator or a sorter can be used as the printing device 1, and hastening the drying of the ink by sending air can reduce image contamination due to rubbing between sheets when using the post-processing device. To a high level. If a device such as a heater that raises the temperature of the air to be sent is provided, drying of the ink by sending the air can be further expedited, and in the case of using such a post-processing device, image stains due to rubbing between sheets are further reduced. High level can be prevented. The side fence displacement means is not limited to displacing both side fences 29, 29, and may displace at least one of them.

[0044]

According to the first aspect of the present invention, there is provided a paper discharge tray on which printed paper is stacked, and the paper discharge tray has a side fence for regulating each side edge of the paper. In the apparatus, the side fence is provided with an air flow generating means for sending air between the sheets stacked on the sheet discharge tray, and after the stacking of the sheets on the sheet discharge tray is completed, the air flow generation is performed. Means for feeding air between the sheets stacked on the sheet discharge tray and aligning the sheets stacked on the sheet discharge tray. If you print on
That is, it is possible to provide a printing apparatus capable of satisfactorily aligning the sheets on the sheet discharge tray even when printing that is not appropriate for alignment is performed on paper that is not appropriate for alignment.

According to a second aspect of the present invention, in the printing apparatus of the first aspect, there is provided a detecting means for detecting a size of the sheet, and the discharge tray is at least one of the side fences. Has side fence displacement means for displacing the paper in the width direction of the paper, and the side fence displacement means displaces the distance between the fences according to the width of the paper detected by the detection means. Regardless of the size, it is possible to provide a printing apparatus capable of satisfactorily aligning the sheets on the sheet discharge tray.

According to the third aspect of the present invention, in the printing apparatus according to the second aspect, the side fence displacement means makes the width between the side fences substantially the same as the width of the sheet. By stacking paper between the side fences that are almost the same width as the paper, a certain amount of paper can be aligned at the time of paper ejection, and then printing that can perform good paper alignment by blowing air An apparatus can be provided.

According to a fourth aspect of the present invention, in the printing apparatus according to the second aspect, the side fence displacement means determines the width between the side fences and terminates the stacking of sheets on the discharge tray. The width of the paper is set to be smaller than the width of the paper until the paper is loaded on the paper output tray, and the width of the paper is almost the same as the width of the paper. It is possible to provide a printing apparatus capable of performing good alignment, and performing good alignment of paper by blowing air thereafter and setting the width of the side fence to approximately the width of paper.

According to a fifth aspect of the present invention, in the printing apparatus according to the fourth aspect, the side fence displacement means is smaller than the width of the sheet after the stacking of the sheet on the sheet ejection tray is completed. Before making the width between the side fences approximately the same as the width of the paper,
At least once, the width of the paper is larger than the width of the paper. Therefore, when the distance between the side fences once larger than the width of the paper is substantially equal to the width of the paper, the paper is aligned by the side fences. It is possible to provide a printing apparatus capable of aligning sheets and performing a jogging operation so that the sheets can be aligned more favorably.

According to a sixth aspect of the present invention, in the printing apparatus according to the fourth or fifth aspect, after the side fence displacement unit makes the side fence approximately the same as the width of the sheet, the air flow generating unit is turned off. Since the stoppage is performed, it is possible to provide a printing apparatus that can always perform blowing of air when the side fence is displaced after the sheets are stacked, and the sheets can be aligned properly.

According to a seventh aspect of the present invention, in the printing apparatus according to any one of the first to sixth aspects, the rectifying member for rectifying the air flow generated by the air flow generating means is provided. Since the side fences are provided, it is possible to blow a uniform and stable flow of air between the sheets stacked on the sheet discharge tray, so that it is possible to provide a printing apparatus capable of performing good sheet alignment. .

According to an eighth aspect of the present invention, in the printing apparatus according to any one of the first to seventh aspects, there is provided a detecting means for detecting a size of a sheet, and the air flow generating means comprises: In the case where the size of the paper is small, a plurality of air flow generation means to be activated among the plurality of air flow generation means are determined in accordance with the length of the paper detected by the detection means. Thus, it is possible to provide a printing apparatus capable of suppressing unnecessary energy consumption by operating only the airflow generating means necessary for paper alignment.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a stencil printing apparatus to which the present invention is applied.

FIG. 2 is a schematic plan view of the paper discharge tray shown in FIG.

FIG. 3 is a schematic front view of the paper discharge tray shown in FIG.

FIG. 4 is a schematic side view of the paper discharge tray shown in FIG.

FIG. 5 is a plan view showing the internal configuration of the paper discharge tray shown in FIG.

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 2 showing a configuration of the airflow generating device.

FIG. 7 is a front view of the air flow generator shown in FIG.

FIG. 8 is a side sectional view showing another example of the airflow generating device.

FIG. 9 is a front view of the airflow generation device shown in FIG.

FIG. 10 is a schematic front view showing a state of side fences and sheets when sheets are stacked on a sheet discharge tray.

FIG. 11 is a schematic front view showing a state of side fences and sheets after sheets are stacked on a sheet discharge tray.

FIG. 12 is a schematic front view illustrating a state of a sheet when an air flow generating unit is operated.

FIG. 13 is a schematic front view illustrating a state of a sheet when a width between side fences is set to a sheet width.

FIG. 14 is a schematic front view showing a state in which the air flow generating means is stopped and the alignment of sheets is completed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Printing apparatus 6 Paper discharge tray 29 Side fence 58-67 Side fence displacement means 114, 117, 118 Rectifying member 119 Air flow generation means L Width between side fences larger than the width of paper S Each smaller than the width of paper Width between side fences W Width of paper, width between each side fence which is almost the same as paper width

Claims (8)

[Claims] 1. A printing apparatus having a paper discharge tray on which printed paper is stacked, wherein the paper discharge tray has side fences for regulating respective side edges of the paper. An airflow generating means for feeding air between the sheets stacked on the paper tray is provided, and after the sheets are stacked on the discharge tray, the airflow is generated on the discharge tray by the airflow generating means. A printing apparatus, wherein air is sent between the stacked sheets to align the sheets stacked on the sheet discharge tray. 2. The printing apparatus according to claim 1, further comprising a detecting unit configured to detect a size of the sheet, wherein the discharge tray includes:
Side fence displacement means for displacing at least one of the side fences in the width direction of the paper, wherein the side fence displacement means determines the distance between the fences according to the width of the paper detected by the detection means. A printing device characterized by being displaced. 3. The printing apparatus according to claim 2, wherein said side fence displacement means makes a width between said side fences substantially equal to a width of a sheet. 4. The printing apparatus according to claim 2, wherein the side fence displacement means makes the width between the side fences smaller than the width of the paper until the loading of the paper on the paper discharge tray is completed. A printing apparatus, wherein the width of the paper after the stacking of the paper on the paper discharge tray is substantially equal to the width of the paper. 5. The printing apparatus according to claim 4, wherein the side fence displacement means sets the width between the side fences smaller than the width of the sheet after the stacking of the sheets on the discharge tray. The printing apparatus according to claim 1, wherein the distance between the side fences is set to be larger than the width of the sheet at least once before the width is substantially equal to the width of the sheet. 6. A printing apparatus according to claim 4, wherein said side fence displacement means stops said air flow generation means after making said side fence substantially equal to the width of a sheet. apparatus. 7. A printing apparatus according to claim 1, wherein a rectifying member for rectifying an air flow generated by said air flow generating means is provided on said side fence. Printing device. 8. A printing apparatus according to claim 1, further comprising a detecting means for detecting a size of the sheet, and a plurality of said air flow generating means provided in a length direction of the sheet. , According to the length of the paper detected by the detection means,
A printing apparatus, wherein an air flow generating means to be operated among the plurality of air flow generating means is determined.