JPH0557975A - Printer - Google Patents

Abstract

PURPOSE:To ensure that the rear end of a sheet after printing can be pushed out of a printing position to a sheet retaining part, and a sheet can be discharged without fouling its surface immediately after printing with the minimization of space for installing a device. CONSTITUTION:The subject printer consists of a means 47 for printing which is installed in opposition to a sheet transport path on a printer and prints the sheet being transported through the path, a sheet holding part 40 which is provided at the upward of a downstream part of a sheet transport direction and holds a printed sheet positioned obliquely with the tip lifted high in the sheet transport direction, means 36, 57 for feeding the sheet which transports the sheet set near the upstream part of a sheet transport direction of the means 47 for printing in the sheet transport path, to the means 47 for printing and a means 43 for discharging the sheet which moves forward in the sheet transport path behind the rear of the sheet after the passage of the rear end of the sheet near the means for transport, and at the same time, moves to a sheet discharge direction and pushes the rear end of the sheet to a sheet holding part side to discharge the sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire dot printer, an ink jet printer or the like, and more particularly to a sheet discharge for conveying and discharging ink without bleeding ink on a sheet after printing or contaminating a printing surface of the sheet after printing. Regarding the improvement of the mechanism.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9 to FIG. 12, a known mechanism for discharging a sheet after printing in a printer is known. That is, in FIG. 9, the print head 2 is provided so as to face the rotatable cylindrical platen 1. Also,
Pinch rollers 3 are provided at two locations around the platen 1 on the upstream side of the print head 2 in pressure contact with the platen 1. Further, around the downstream side of the print head 2 of the platen 1, a bail roller 4 formed of an ink absorber is provided in pressure contact with the platen 1.

Then, the unprinted paper 5 is sandwiched between the platen 1 and the pinch roller 3 and guided between the platen 1 and the print head 2 along the peripheral surface of the platen 1, and the print head 2 is moved to the platen 1 of the platen 1. Printing is performed while reciprocating in the axial direction. Then, the printed sheet 5 is conveyed to the sheet discharge position by the bail roller 4 and discharged into a sheet discharge tray (not shown).

In FIG. 10, a gear-shaped star ring 6 is used in place of the bail roller 4 formed of an ink absorber in FIG.

Next, as shown in FIGS. 11 and 12,
A feed roller 12 rotatable around a shaft 11 and a pinch roller 1 pressed against the peripheral surface of the feed roller 12.
3, a platen 14 rotatable around a shaft 11 between a printing position and a retracted position, and a printing unit 15 of the platen 14.
A print head 16 which is arranged to face each other and reciprocates along an axis 11, and a paper discharge tray 17 which horizontally receives the printed paper.
And have.

As shown in FIG. 11, the unprinted paper 18 is sandwiched between the feed roller 12 and the pinch roller 13, and the platen 14 and the print head 16 at the print position are arranged along the peripheral surface of the feed roller 12. The print head 16 guides the user to print. After the printing is completed, the platen 14 is rotated from the printing position to the retracted position as shown in FIG. 12, and the printed paper 18 is stored in the paper discharge tray 17 by its own weight.

[0007]

However, such a conventional paper discharge device for a printer has the following drawbacks. First, in FIGS. 9 and 10, the undried ink bleeds by pressure contact by the bail roller 4 or the Stirling 6 that rotates on the printing surface of the paper immediately after printing, or the undried ink is transferred to the printing surface of the paper. The bail roller 4 and the sterling 6 are formed in the shape of an ink absorber or a gear as described above in order to prevent stains on the printing surface of the paper, but when high density printing or continuous printing is performed, these The bail roller 4 and the Sterling 6 cannot sufficiently deal with the problem, and the print surface is contaminated due to the above-mentioned cause.

11 and 12, the surface of the paper after printing is not contaminated, but the inertial force and the self-weight of the paper are eliminated without using a mechanism for forcibly discharging the paper after printing. Since the paper is discharged by using the paper, the paper discharge tray 17 needs to be positioned in a horizontal plane including the print head 16 and provided in a substantially horizontal direction, resulting in a large installation area of the entire apparatus.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a printer is provided in a printer so as to face a paper transport path and prints on a paper transported in the paper transport path, and a printing means upstream and downstream of the print means. A paper holding section for holding printed sheets with the front end in the paper carrying direction inclined and a paper holding means provided in the vicinity of the upstream side of the printing means in the paper carrying direction in the paper carrying direction. And a paper feed unit that conveys the paper toward the rear end of the paper after the rear end of the paper has passed near the conveyance unit and advances into the paper conveyance path behind the rear end of the paper and moves in the paper conveyance direction. A paper ejecting unit that ejects the paper by pushing the rear end toward the paper holding unit is provided.

[0010]

According to the present invention thus constituted, the sheet discharging means is brought into contact with the trailing edge of the sheet and moved from the vicinity of the sheet feeding means to the sheet holding section to convey the trailing edge of the sheet after printing. Extrude along the path to the paper holding unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 8 using an ink jet printer as an embodiment. In FIG. 1, a frame 3 which is an outer case of the inkjet printer.
A sheet storage section 33 for stacking and holding a large number of unprinted sheets 32 together with a power source section and a control section (not shown)
It has a paper discharge mechanism 34 that feeds the paper 32 held by the paper holder 33 and discharges the printed paper 32.

As shown in FIG. 2, the paper discharge mechanism 34 includes three rollers 36 fixed to a rotary shaft 35 at equal intervals.
A feed roller 36 having a, 36b, 36c and rotating with the rotary shaft 35, and pieces 37a, 37b, 37c, 37 provided for the feed roller 36.
d and 37e have a platen 37 in which a predetermined gap 38 is provided. Each piece of the platen 37 has a printing surface 39 which is flat and flush with each other.
As shown in FIG. 1 and FIG. 3, it is formed integrally with a paper discharge stocker 40 (paper holding unit) which has a predetermined angle with the installation surface of the frame body 31 of the printer and is arranged above the print head 47 described later. ing. This platen 37 and the paper output stocker 4
At the boundary with 0, a paper discharge trailing edge holding unit 41 that holds the trailing edge of the printed paper 32 discharged into the paper discharge stocker 40.
Are provided by forming a step between the platen 37 and the stocker 40.

The paper discharge mechanism 34 is fixed to a shaft 42 parallel to the rotary shaft 35 and rotates 43a together with the shaft 42,
Four eject arms 43, 43b, 43c and 43d
The eject arm 43 has a (sheet discharging means), and reciprocally rotates in a gap 38 provided between the platens 37 between an initial position shown by a solid line and an pushing position shown by a broken line. ..

As shown in FIG. 4, two eject arms 43 are integrally formed, are press-fitted into the shaft 42, and have a substantially L-shaped bent portion 45 at the tip thereof. ..

Further, in FIG. 1, a print head 47 (printing means) is provided so as to reciprocate along the longitudinal direction of the platen 37 so as to face the print surface 39 of the platen 37. The print head 47 detachably holds an ink cartridge (not shown) containing ink, and reciprocates to respond to a predetermined print signal to eject ink drops onto the platen 37.
The characters are ejected toward the printing surface 39 to print characters and figures on the paper 32.

Next, in the paper storage portion 33, a movable portion 51 is rotatable around a fulcrum 50 in a direction toward and away from the feed roller 36, and a spring 52 fixed at one end always causes the feed roller 36 to move toward the feed roller 36. Is urged by. Further, the cam 53 is rotatably provided, and the movable portion 51
The movable portion 51 of the paper storage portion 33 can be separated from the feed roller 36 by pressing the action portion 54 provided on the sheet against the biasing force of the spring 52 by the rotation thereof. Then, when the cam 53 further rotates, it separates from the acting portion 54, and the leading end portion of the movable portion 51 of the paper storage portion 33 contacts the peripheral surface of the feed roller 36. Therefore, by rotating the cam 53 in response to the paper feed signal, the paper 32 in the paper storage unit 33 moves the leading end of the paper 32 to the feed roller 36.
Can be appropriately pressed against the peripheral surface of the.

A paper guide 56 is provided along a part of the peripheral surface of the feed roller 36, and between the peripheral end of the paper guide 56 and the print surface 39 of the platen 37 and upstream of the print head 47. A pinch roller 57 for feeding the paper between the print surface 39 and the print head 47 is provided on the side.
The feed rollers 36a, 36b, 36c, and 36d are provided so as to face each other. The paper guide 56
Part of this has a manual insertion guide 59 for guiding the manual insertion paper inserted from the manual insertion opening 58 formed in the frame 31 to the printing surface 39.

In such a structure, normally, the unprinted sheets 3 stacked in the sheet storage unit 33 as shown in FIG.
2 is separated from the peripheral surface of the feed roller 36. Then, when a print signal is input from an external host computer, a control unit (not shown) generates a paper feed signal at a predetermined timing. Then, the cam 53 rotates, and the urging force of the spring 52 causes the uppermost sheet 32 stacked in the sheet storage unit 33 to contact the peripheral surface of the feed roller 36. When the feed roller 36 rotates, the uppermost sheet 32
Is guided between the feed roller 36 and the paper guide 56, and is guided by the paper guide 56 from the pinch roller 57 to between the print surface 39 of the platen 37 and the print head 47 and stopped at a predetermined position. Then, at this timing, the cam 53 further rotates to push down the action portion 54 of the movable portion 51 provided in the paper storage portion 33 against the urging force of the spring 52, so that the movable portion 51 is lowered and the paper is stored. Part 3
The sheets 32 stacked in the sheet 3 are separated from the feed roller 36.

Next, based on the input print signal, the print head 47 reciprocates to eject ink droplets to adhere to the paper 32 for printing. Also, the paper 32 nipped by the feed roller 36 and the pinch roller 57 is conveyed by rotating the feed roller 36 by a predetermined amount each time the print head 47 reciprocates. Then, by rotating the feed roller 36, the printed paper is
The trailing edge of the sheet 32 is the feed roller 36 and the pinch roller 5.
The sheet is conveyed to a position where it is no longer held with the sheet 7 (see FIG. 3). At this time, the eject arm 43 is located at the initial position (see FIGS. 2 and 3; FIG. 3 shows a state perpendicular to the rotary shaft 35 between the platen 37b and the eject arm 43b in the state of FIG. 2). It is a sectional view).

Next, the eject arm 43 starts rotating from the initial position toward the push-out position and abuts on the trailing edge of the printed sheet 32, and pushes the trailing edge toward the sheet discharging stocker 40. Start (FIGS. 5 and 6 show the process of pushing up. FIG. 6 shows the platen 37b and the eject arm 4 in the state of FIG.
3b is a cross-sectional view taken along a plane perpendicular to the rotation axis 35 with respect to 3b).

When the eject arm 43 further rotates to reach the push-out position, the pushed-up paper 32 is ejected and drops into the paper ejection stocker 40, and then the paper is ejected to the paper ejection rear end holding portion 41. The edge is held (see FIGS. 7 and 8, FIG. 8 is a cross-sectional view taken in a plane perpendicular to the rotation axis 35 between the platen 37b and the eject arm 43b in the state of FIG. 7).

As described above, according to the present embodiment, the eject arm 43 is rotated to push up the rear end of the printed paper 32 to eject the paper into the paper ejection stocker 40. It is possible to discharge the paper without staining the printing surface of the paper immediately after printing without using such as. Further, even if the paper ejection stocker 40 is provided at a predetermined angle with respect to the installation surface of the frame body 31 of the printer, the printed paper 32 can be ejected into the paper ejection stocker 40, thus reducing the installation area of the entire apparatus. Can be kept to a minimum.

Further, since the platen 37 and the stocker 40 have a step due to the paper discharge rear end holding portion 41, the paper 3
It does not come into contact with the sheet previously discharged into the stocker 40 until the ejecting arm 43 pushes the sheet 2 a considerable distance. Therefore, since the ink on the previously ejected paper is dried during that time, even if the paper 32 ejected in the stocker 40 last time and the paper 32 ejected this time come into contact with each other in the middle, the ink of the previous paper may be bleeding, There is no risk of the paper getting dirty.

As described above, since the present invention is configured as described above, the paper discharging means can push the rear end of the paper after printing from the printing position to the paper holding portion side, and immediately after printing. It is possible to discharge the paper without contaminating the printing surface of the paper, and the installation area of the entire device can be minimized.

[Brief description of drawings]

FIG. 1 is a side view showing an internal structure of an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of an embodiment of the present invention.

FIG. 3 is a cross-sectional view in the state of FIG.

FIG. 4 is a diagram showing a coupled state of an eject arm 43 and a shaft 42.

FIG. 5 is a perspective view showing a main part of an embodiment of the present invention.

FIG. 6 is a sectional view in the state of FIG.

FIG. 7 is a perspective view showing a main part of an embodiment of the present invention.

FIG. 8 is a sectional view in the state of FIG.

FIG. 9 is a diagram showing a conventional example of the present invention.

FIG. 10 is a diagram showing another conventional example of the present invention.

FIG. 11 is a diagram showing still another conventional example of the present invention.

FIG. 12 is a diagram showing still another conventional example of the present invention.

[Explanation of symbols]

 33 Paper Storage Section 34 Paper Ejection Mechanism 36 Feed Roller 37 Platen 38 Gap 39 Printing Surface 40 Paper Ejection Stocker 41 Ejection Trailing Edge Holding Section 43 Eject Arm 47 Print Head 56 Paper Guide 57 Pinch Roller

Claims (1)

[Claims] 1. A printing unit which is provided so as to face a paper transport path and prints on a paper transported in the paper transport path,
A paper holding portion which is provided on the downstream side of the printing means in the paper carrying direction and holds the printed paper with the front end in the paper carrying direction being inclined and near the upstream side of the printing means in the paper carrying direction in the paper carrying path. A sheet feeding means for conveying the sheet toward the printing means, and a rear end of the sheet advancing into the sheet conveying path behind the rear end of the sheet after passing near the conveying means, and A printer comprising: a sheet discharging unit that moves in the transport direction and pushes the rear end of the sheet toward the sheet holding unit to discharge the sheet.