JPH05319666A - Paper discharge base for printing device - Google Patents

Abstract

PURPOSE:To provide a paper discharge base for printing device capable of preventing the rubbing soil of a printed image at discharge and the discharge jam at high speed print, and regularly surely and precisely stacking discharged sheets. CONSTITUTION:On a pair of side plates 123 raised on the bottom plate 120 of a paper discharge base 52 to be mutually opposed along the discharging direction of sheets, a number of air sucking holes 126 are formed. On the outside surface of each side plate 123, sucking means 127, 129 for sucking the air on the paper discharge base 52 through the air sucking holes 126 are arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge tray of a printing apparatus, and more particularly to a paper discharge tray on which a relatively large amount of sheet-shaped printing paper is discharged and stacked.

[0002]

2. Description of the Related Art As is well known, a paper discharge tray of a printing apparatus is generally peeled from a print drum by a paper discharge peeling claw after printing and hung on a suction paper discharge inlet roller and a suction paper discharge outlet roller. The printing paper discharged and dropped outside the machine is sequentially stacked and placed by the paper discharging and conveying device including the conveying belt and the suction fan. In other words, when the paper is conveyed from the print drum to the top of the paper ejection tray by the conveyor belt, the paper ejecting / conveying device of the printing device sucks the print paper by the suction fan, and the protruding member sucks the print paper on the paper. Eject the print paper with the mark attached. The printing paper thus discharged from the paper discharging and conveying device slides between a pair of side plates erected on the bottom plate of the paper discharging tray of the printing device, and is substantially orthogonal to the paper discharging path on the paper discharging tray. The leading edge of the paper collides against the front impingement wall plate that is erected like this, and when the stopped printing paper falls, the air at the bottom of the paper escapes from the air vent opening provided on the side plate. By doing so, it is loaded on the bottom plate.

Prior arts relating to the paper ejection tray of this type of printing apparatus include Japanese Utility Model Laid-Open No. 63-148670 "Paper guide guide stopper of printing machine" and Japanese Utility Model Publication No. 2-91747 "Paper ejection tray of printing apparatus" , Japanese Utility Model Laid-Open No. 2-124966, "Paper discharge tray of stencil printer", and the like are known.

[0004]

By the way, the paper discharge tray of the conventional printing apparatus generally has a pair of side plates and a pair of side plates erected on the bottom plate thereof so that a large amount of printing paper can be stacked at one time. The front wall is relatively high, and
It is installed so that the height difference between the paper discharge height of the paper discharge conveying device and the height of the paper stacking surface (top surface of the bottom plate) of the paper discharge tray is relatively large. Therefore, with this type of conventional output tray,
When the ejected printing paper falls freely, especially when the paper thickness is thin, the air will not escape at the bottom of the paper and the falling speed of the paper will be slow, so the leading edge of the paper ejected later , Slide while rubbing the surface of the paper that was ejected and dropped first. For this reason, in the discharge tray of the conventional printing apparatus, the printed images of the stacked sheets are rubbed and smeared, or the trailing edge of the discharged sheets cannot be dropped during high-speed printing. The leading edge of the succeeding sheet collides with the trailing edge of the sheet, which easily causes a sheet discharge jam.

The present invention has been made in view of the above-mentioned points, and an object thereof is to prevent rubbing and smearing of a printed image at the time of discharging a paper sheet and to prevent a paper discharge jam at the time of high-speed printing, and to always make sure. Another object of the present invention is to provide a paper discharge tray of a printing apparatus that can stack discharged paper accurately.

[0006]

In order to solve the above-mentioned problems, the present invention is a paper ejection tray that receives a printing paper ejected from a paper ejection port of a printing apparatus, and ejects the paper to a bottom plate of the paper ejection tray. It has a pair of side plates erected so as to be opposed to each other along the direction, and a large number of air suction holes are formed in the pair of side plates, and the air discharge holes are passed through the outer side surface of each side plate. Suction means for sucking air on the table is provided.

[0007]

According to the present invention, the sheet discharge tray is provided by the suction means through a large number of air suction holes of a pair of side plates which are vertically provided on the sheet discharge tray bottom plate so as to face each other along the sheet discharge direction. Since the upper air is sucked, the printing paper discharged onto the paper discharge tray is surely dropped by its own weight.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. However, with respect to the configuration, operation, and the like within the range that can be clearly recalled from the description of the present embodiment, their illustration and disclosure will be omitted or simplified in order to avoid complication of the description.

In FIG. 1, the printing drum 10 of the printing apparatus is shown.
1 is a state in which the master 61 is wound around the outer peripheral surface,
It is rotationally driven in the clockwise direction by a driving device (not shown). A press roller 103 that comes in contact with and separates from the print drum 101 is provided around the print drum 101, and at a timing synchronized with the rotation of the print drum,
When the paper 62 is fed, the press roller 103 moves toward the print drum 101. As a result, the press roller 103 presses the sheet 62 against the master 61, and the image of the master 61 is printed on the sheet 62.

Further, when viewed in the feeding direction of the paper 62 from the printing drum 101, a paper discharge peeling claw 113 is provided in front of it.
And a sheet discharging and conveying device 53. Paper ejection peeling claw 1
13 approaches the outer peripheral surface of the print drum 101 at a predetermined timing synchronized with the rotation of the print drum 101, and peels the paper 62 attached to the master 61 from the master 61. The sheet 62 separated from the master 61 is drawn by the suction fan 117 of the sheet discharging and conveying device 53 between the suction and sheet discharging inlet roller 114 and the suction and sheet discharging outlet roller 115, and is sucked onto the rotating conveyor belt 116. Meanwhile, it is transported along the transport belt 116. In addition, the raised member 118 is provided in the vicinity of the sheet discharge port of the discharged sheet conveying device 53.
Is provided, and when the paper 62 is discharged from the paper discharge port, the user sits down.

On the other hand, a sheet discharge tray 52 is provided in the sheet discharge direction of the sheet conveying device 53. This delivery table 53
It has a bottom plate 120, a front impact wall plate 121 erected on the bottom plate 120, and a pair of side plates 123. In addition, the bottom plate 120 includes a front impact wall plate 121 and a pair of side plates 123.
The guide grooves 122 and 124 for guiding and are provided along the guide grooves 122 and 124.
21 and each side plate 123 are configured to be movable according to the paper size of the discharged paper 62.

Further, each side plate 123 is provided with a large number of air suction holes 126 in the vertical direction at the center thereof and air vent openings 125 in the vertical directions at both ends thereof. here,
The holes of the air suction holes 126 are arranged regardless of the number of sheets stacked on the sheet discharge tray 52. Further, a suction part cover 127 is provided on the outer side surface of each side plate 123 so as to cover each air suction hole 126, and a suction fan 128 is attached below the inside of these suction part covers 127, respectively. Has been. In addition, each suction section cover 127
An exhaust port 129 is formed in each of the parts to which the suction fan 128 is attached. These suction section cover 127, suction fan 128, and exhaust port 129
When the paper 62 discharged from the paper discharge conveying device 53 slides between the side plates 123 of the paper discharge tray 52 and is received by the front impact wall plate 121 and falls freely, As shown in FIG. 4, the suction fans 128 function to discharge the air below the sheet 62 to the outside through the air suction holes 126 of the side plates 123.

That is, as shown in FIG. 5, the suction fan 128 has a plate making / printing start key 14 on the operation panel.
When 0 is pressed and a command is issued from the central control unit 150, it is controlled and operated by the paper ejection tray suction control unit 151, and stopped at the end of plate making / printing. Further, the suction device (suction fan 128) of the present embodiment is controlled so as to suck with a suction force according to the set printing speed designated by the printing speed key 141 on the operation panel. Further, the suction device (suction fan 128) of the present embodiment has one side plate 123.
The suction force is controlled in accordance with the stacking height of the paper 62 on the discharge tray 52 detected by the stacking height detecting means 130 provided in the. However, in this suction device (suction fan 128), the discharged paper 62 is
The suction force is controlled so that the suction force is within a range that does not cause the side plate 123 to stick. In addition, the stacking height detection unit 130 is configured, for example, by arranging several photosensors at a predetermined interval in the vertical direction of the side plate 123. Depending on the number, the paper 62 on the output tray 52
It is configured to detect the stacking height of the.

On the other hand, the air suction holes 126 of each side plate 123.
6 may be formed on the entire surface of the side plate 123, as shown in FIG.
3 is configured to have a constant suction force in the left-right direction.
As another suction means for sucking the air under the discharged and dropped paper 62, as shown in FIG. 7, a suction vacuum device 131 may be used. When the main body of the printing device is installed on the vacuum device 131, a suction hose 132 or the like is used.
The suction vacuum device 131 and each suction unit cover 127 are connected. In addition, in order to simplify the configuration of the suction unit, for example, the suction fan 117 of the sheet discharging and conveying device 53 may be used as the suction vacuum device 131.

Although the present invention has been described with reference to a specific embodiment, the configuration of the present invention is not limited to the above embodiment, and various embodiments can be configured within the scope of the present invention. it is obvious. For example, the suction means,
One end is connected to the suction part of one suction device, and the other end is branched and configured by the air ducts respectively arranged on the outer surfaces of the side plates, so that the space on the discharge tray can be widely utilized, In addition, there are cost advantages,
The suction force of each side plate is made uniform, and a more stable paper drop can be obtained.

[0016]

According to the present invention, since the discharged paper lower part is sucked through the air suction hole of the side plate regardless of the discharged paper stacking height, the falling of the paper is not delayed and the thin paper is not delayed. The rubbing stains on the printed image and the paper discharge jam are eliminated, a stable paper drop is obtained, and the discharged paper can always be stacked reliably and accurately.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a paper discharge table according to the present invention.

FIG. 2 is a schematic plan view of a paper discharge tray in the above embodiment of the present invention.

FIG. 3 is a perspective view of a paper discharge tray in the above embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of an essential part showing the flow of air on the sheet discharge tray in the above embodiment of the present invention.

FIG. 5 is a block diagram showing a suction control unit of the sheet discharge tray in the above embodiment of the present invention.

FIG. 6 is a perspective view showing another example of the side plate used for the paper discharge tray in the above embodiment of the present invention.

FIG. 7 is a schematic sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 52 Paper ejection table 120 Bottom plate 121 Front wall 122,124 Guide groove 123 Side plate 125 Air vent opening 126 Air suction hole 127 Suction section cover 128 Suction fan 129 Exhaust port 130 Stacking height detection means

Claims (5)

[Claims] 1. A paper discharge tray for receiving print paper discharged from a paper discharge port of a printing apparatus, wherein a pair of side plates are provided on a bottom plate of the paper discharge tray and are erected so as to face each other along a paper discharge direction. A plurality of air suction holes are formed in the pair of side plates, and suction means for sucking the air on the discharge tray through the air suction holes is arranged on the outer surface of each side plate. Output tray of the printing device. 2. The suction means comprises air ducts, one end of which is connected to a suction portion of one suction device, and the other end of which is branched and which are respectively arranged on the outer side surfaces of the side plates. The paper output tray of the printing apparatus according to claim 1. 3. The printing according to claim 1, wherein the suction means sucks the air on the paper ejection tray with a suction force according to a set printing speed designated by an operating section of the printing device. Output tray of the device. 4. The suction means is arranged on a side plate of the paper discharge table and is based on a detection output of a stacking height detection means for detecting a stacking height of print sheets discharged on the paper discharge table. 2. The discharge tray of the printing apparatus according to claim 1, wherein air on the discharge tray is sucked by a suction force according to a stacking height of the print sheets discharged on the discharge tray. 5. The suction means sucks the air on the paper discharge tray with a suction force corresponding to a set printing speed designated by the operation unit of the printing apparatus, and is further discharged onto the paper discharge tray. Based on the detection output of the stacking height detection means that detects the stacking height of the printing paper, the suction force is changed according to the stacking height of the printing paper discharged onto the paper discharge tray, and the above two conditions are satisfied. The discharge tray of the printing apparatus according to claim 1, wherein the air on the discharge tray is sucked by an optimum suction force that is a combination of the above.