JPH089084Y2 - Printer paper feed mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a paper feeding mechanism of a printer, and more particularly to a printer for feeding paper stored in a paper feed tray one by one to a predetermined printing position. Regarding the paper feeding mechanism.

[Conventional technology]

Conventionally, a paper feed mechanism for detachably mounting a paper feed tray in which a plurality of paper sheets are stored inside a printer and taking out the paper sheets from the paper feed tray one by one and conveying them to a predetermined printing position is provided. Provided printers are known.

In such a printer, a paper feed roller for taking out the papers in the paper feed tray one by one is provided, and the paper is supplied to a predetermined printing position on the downstream side of the paper feed roller in the paper conveyance direction. A paper feed roller and a pressure contact roller pressed against the paper feed roller are provided. Further, on the downstream side of the printing position, a paper discharge roller for discharging the paper after printing and a pressure contact roller that is in pressure contact with the paper discharge roller are provided, and the paper feed roller and the paper discharge roller are It is adapted to be rotationally driven while being synchronized by one paper feed drive motor.

In the above-described conventional paper feeding mechanism, the paper feeding roller is rotationally driven to take out the uppermost paper from the paper feeding tray, and the paper feeding drive motor is driven to drive the paper feeding. The roller is rotationally driven to convey the sheet to a predetermined printing position. The paper on which the desired printing is completed is discharged to the outside of the printer body by the paper discharge roller and the pressure contact roller.

[Problems to be solved by the device]

However, since the paper feeding mechanism of the conventional printer described above drives the paper feeding roller and the paper discharging roller in synchronization with the paper feeding motor, when the paper feeding roller and the paper discharging roller are out of synchronization with each other. , If the paper being conveyed is slackened or pulled,
There is a problem in that a conveyance abnormality occurs and proper paper cannot be conveyed, and as a result, proper printing cannot be performed on the paper.

The present invention has been made in view of the above points, and an object of the present invention is to provide a paper feed mechanism of a printer that can appropriately convey a paper and can perform appropriate printing.

[Means for solving the problem]

In order to achieve the above-mentioned object, the paper feeding mechanism of the printer according to the present invention has a paper feed roller for taking out predetermined papers one by one inside the printer body so as to be rotatably driven by a paper feed drive motor. A paper feed roller that conveys the paper conveyed by the paper roller to a predetermined printing position, and a pressure contact roller that is in pressure contact with the paper feed roller are provided.
In a paper feed mechanism of a printer having a paper discharge roller for discharging printed paper, a clutch mechanism for rotating the paper feed roller only in a predetermined paper feed direction is connected to the paper feed roller. A roller contact / separation mechanism is provided that presses the pressure contact roller against the paper feed roller by rotation of the paper feed drive motor in the paper feed direction, and separates from the paper feed roller by rotation of the paper feed drive motor in the opposite direction. It is characterized by that.

[Action]

According to the present invention having the above-described configuration, the paper feed drive motor is driven to rotationally drive the paper feed roller to take out the paper, and the roller contact / separation mechanism allows
It is possible to bring a pressure contact roller into pressure contact with the paper feed roller, and to sandwich the paper by the paper feed roller and the pressure contact roller to convey the paper to a predetermined printing position. When the leading edge of the paper after printing is conveyed to the vicinity of the paper discharge roller, the paper feed drive motor is driven to rotate in the opposite direction, and the pressure contact roller is separated from the paper feed roller by the roller contact / separation mechanism. Then, the paper can be discharged only by the paper discharge roller. At this time, the clutch mechanism prevents the paper feed roller from rotating in the reverse direction.

〔Example〕

Hereinafter, the present invention will be described with reference to the embodiments shown in the drawings. In FIGS. 3 to 5, gears and the like overlapping in the front-rear direction are shown by solid lines in order to make the drive transmission easy to understand.

1 and 2 show an embodiment of a printer to which the paper feeding mechanism according to the present invention is applied. A flat platen 3 is arranged on a frame 2 of the printer 1. A guide shaft 4 is disposed in the vicinity of 3 in parallel with the platen 3. A carriage 5 is movably attached to the guide shaft 4 along the guide shaft 4, and a print head 6 such as a thermal head is attached to the platen 3 on the carriage 5.
It is installed so as to face. Both sides of the carriage 5 are connected to both ends of a rotary roller 8 driven to rotate by a carriage drive motor 7 and a transfer belt 10 stretched around a plurality of guide rollers 9, 9 ,. By driving the motor 7 and the rotation roller 8 to rotate, the front transfer moving belt 10 is driven so that the carriage 5 can reciprocate along the guide shaft 4.

Behind the platen 3 is formed a paper insertion opening 11 for inserting the paper 1 by manual feeding or the like. The paper insertion opening 11 is provided between the platen 3 and the print head 6 for inserting the manual paper 1. A manual paper guide 12 for guiding to is formed. Further, below the carriage 5, a paper feed tray 14 for accommodating and stacking a plurality of sheets of paper 13, 13 ... Is detachably arranged. Near the tip of the paper feed tray 14, A paper guide 15 is arranged to guide the paper 13 in the paper feed tray 14 between the platen 3 and the print head 6.
Further, paper feed rollers 16 and 17 are rotatably arranged at intermediate portions of the manual paper guide 12 and the paper guide 15, respectively, and a paper discharge roller 18 is freely rotatable above the platen 3. It is installed in.

The paper feed rollers 16 and 17 and the paper discharge roller 18 are
Pressing rollers 19, 20 and 21 are pressed against each other, and the pressing roller 20 of the paper guide 15 can be brought into contact with and separated from the paper feeding roller 17. In addition, each of the paper feed rollers 16 and 1
A paper feed drive motor 22 is connected to the 7 and the paper discharge rollers 18 via a drive transmission mechanism (not shown). By driving the paper feed drive motor 22, the paper feed rollers 16 and 17 and the paper discharge rollers 18 are discharged. The roller 18 can be synchronously driven to rotate.

Further, as shown in FIG. 3 and FIG. 4, swing arms 23, 23 are attached to both sides of the frame 2 so as to be swingable around the right end portion in the figures. A rotary shaft 25 having a plurality of paper feed rollers 24 mounted on the outer periphery thereof is disposed between the swing arms 23. A paper feed drive motor 26 is disposed near one of the swing arms 23, and the rotary drive force of the output gear 26a of the paper feed drive motor 26 is applied to the one swing arm 23. A gear train 27 that transmits to the rotary shaft 25 is attached.

Then, by driving the paper feed drive motor 26, the rotation shaft 25 is rotated through the gear train 27, and the paper feed roller 24 is driven to rotate, and the paper feed roller 24 is a clutch. The mechanism 28 is rotatable in one direction (counterclockwise in the figure). Further, a contact bar 29 is attached between the tip end portions of the swing arms 23, and a spring 30 for biasing the swing arms 23 downward is connected to the swing arms 23. ing.

Inside the paper feed tray 14, a bottom plate 31 on which a plurality of sheets of paper 13 are stacked is placed so as to be capable of swinging upward, and the paper 13 is placed on both sides of the tip of the bottom plate 31. Separation claws 32 for separating the sheets one by one are provided.

An urging spring 33 for urging the bottom plate 31 upward is attached to the lower surface side of the bottom plate 31.
By the 33, the bottom plate 31 until the top of the paper 13 comes into contact with the stopper 34 formed inside the upper edge of the paper feed tray 14.
Is raised so that the uppermost sheet 13 is always positioned at a constant height.

Further, in the present embodiment, the contact bar of the swing arm 23 is provided on the upper surface side of both side portions on the leading end side of the paper feed tray 14.
There is formed a cam portion 35 against which the 29 comes into contact.
35 is the paper feed roller when the paper feed tray 14 is inserted
When the contact bar 29 is moved upward to a position where 24 does not contact the topmost sheet 13, and the paper feed tray 24 is mounted at the paper feeding position, the paper feed roller 24 moves to the topmost sheet.
The contact bar 29 is shaped so as to descend to a position where it comes into pressure contact with 13.

The output gear 26a of the paper feed drive motor 26 is connected to a selection gear 37 that constitutes a roller contact / separation mechanism via a gear train 36, and a cam plate 38 is provided near the selection gear 37.
A drive gear 39 integrally formed with is disposed. The selection gear 37 is meshed with a pressure contact side gear 40 and a separation side gear 41 which are held by an arm (not shown) and are selectively meshed with the drive gear 39 according to the rotation direction of the selection gear 37. A rotating plate 42 is provided on the selection gear 37.
The rotary shaft 37a is attached so as to be rotatable. A contact projection 43 is formed at one end of the rotating plate 42 for contacting the outer peripheral surface of the cam plate 38.
The pressure contact roller 20 of the paper guide 15 is attached to the other end of 42 via a spring 44.

Further, the rotating plate 42 is provided on the outer peripheral portion of the drive gear 39.
The notch 45 that releases the meshing of the pressure contact side gear 40 when the rotation plate 42 is rotated most clockwise, and the separation side gear 41 when the rotation plate 42 is rotated most counterclockwise. Another notch 46 for releasing the is formed. And the rotating plate
When 42 is rotated most clockwise by the cam plate 38, the pressing roller 20 is pressed against the paper feed roller 17, and when the rotating plate 42 is rotated most counterclockwise by the cam plate 38. The pressure contact roller 20 is separated from the paper feed roller 17.

Next, the operation of this embodiment having the above-described configuration will be described.

First, when the paper feed tray 14 containing the predetermined paper 13 is inserted into the printer 1, the tip of the cam portion 35 of the paper feed tray 14 contacts the contact bar 29 as shown in FIG. The contact bar 29 is pushed up by the cam portion 35. As a result, as shown in FIG. 4B, the swing arm 23 swings upward against the biasing force of the spring 30, and the paper feed roller 24
Is moved upwards. Then, when the paper feed tray 14 is further inserted, the contact bar 29 is lowered by the cam portion 35 and the swing arm 23 is swung downward, and as shown in FIG. When the sheet is mounted at a predetermined sheet feeding position, the sheet feeding roller 24 is pressed against the uppermost sheet 13 by the urging force of the spring 30.

Next, when performing a predetermined printing, by rotating the paper feed drive motor 26 in the clockwise direction in FIG. 4, the paper feed roller 24 is rotationally driven counterclockwise via the gear train 27, and the paper feed roller 24 is rotated. The topmost sheet 13 of the paper tray 14 can be taken out. On the other hand, when the paper feed drive motor 26 is driven to rotate in the clockwise direction, the selection gear 37 is rotated in the counterclockwise direction via the gear train 36 as shown in FIG. As a result, the pressure contact side gear 40 meshes with the drive gear 39. As a result, the drive gear 39 is rotated counterclockwise, and this rotation causes the cam plate 38 to rotate and
42 is rotated clockwise. Then, at the position where the rotating plate 42 is rotated most clockwise, the pressure contact side gear 40 is engaged with the notch 45 of the drive gear 39, the rotation of the drive gear 39 is stopped, and in this state, The pressure contact roller 20 is pressed against the paper feed roller 17.

The paper 13 taken out from the paper feed tray 14 is guided by the paper guide 15 and inserted between the paper feed roller 17 and the pressure contact roller 20, and the paper feed drive motor 22 is driven to drive the paper feed roller. 17 is rotationally driven to convey the paper 13 between the platen 3 and the print head 6. In this state, the carriage drive motor 7 is driven to reciprocate the carriage 5 along the guide shaft 4, and the print head 6 is driven based on a predetermined print signal, so that the desired amount of paper 13 can be obtained. It is possible to print.

Then, when it is detected by a sensor or the like that printing is performed and the leading end of the paper 13 is conveyed to the vicinity of the paper discharge roller 18 and the pressure contact roller 21, as shown in FIG. By rotating the paper feed drive motor 26 in the counterclockwise direction, the selection gear 37 is rotationally driven in the clockwise direction via the gear train 36, and this rotational force causes the separation side gear 41 to mesh with the drive gear 39. As a result, the drive gear 39 is rotated clockwise, and this rotation causes the cam plate 38 to rotate,
The rotating plate 42 is rotated counterclockwise. Then, at the position where the rotating plate 42 is rotated most in the counterclockwise direction, the separating side gear 41 is engaged with the notch 46 of the drive gear 39, and the rotation of the drive gear 39 is stopped. The press roller 20 is separated from the paper feed roller 17.

Then, the paper 13 after printing is conveyed only by the paper discharge roller 18 and the pressure contact roller 21, and is discharged to the outside of the printer 1.

As described above, according to the present embodiment, the paper 13 after printing is completed.
When the sheet is discharged, the pressure contact roller 20 of the paper feed roller 17 is separated and the sheet 13 is discharged only by the sheet discharge roller 18. Therefore, the sheet feed roller 17 and the sheet discharge roller 18 are
It is possible to reliably prevent the conveyance abnormality from occurring due to loosening or pulling of the sheet 13 due to the loss of synchronization with the sheet 13, and it is possible to properly convey the sheet 13. .

It should be noted that the present invention is not limited to the above-described embodiment, but various modifications can be made as necessary.

[Effect of device]

As described above, in the paper feeding mechanism of the printer according to the present invention, the roller contacting / separating mechanism separates the pressure contact roller from the paper feeding roller when ejecting the paper after printing, and only ejects the paper. Since the sheet is ejected, it is possible to reliably prevent the conveyance abnormality from occurring due to the sheet feeding roller and the sheet ejection roller being out of synchronization with each other and the sheet being loosened or pulled. You can
It is possible to properly convey the paper. As a result, it becomes possible to properly print on the paper sent to the print position.

[Brief description of drawings]

1 is a plan view showing an embodiment of a printer to which a paper feeding mechanism according to the present invention is applied, FIG. 2 is a schematic left side view of FIG. 1,
FIG. 3 is a right side view of FIG. 1, FIG. 4 (a) is a side view of an essential part showing a state of starting the insertion of the paper feed tray, and FIG. FIG. 4 (c) is a side view of a main part, FIG. 4 (c) is a partial side view showing a mounted state of a paper feed tray, and FIG. 5 (a) is a side view of the main part showing a pressure contact state of a pressure roller. FIG. 6B is a side view of a main part showing a separated state of the pressure contact roller. 1 ... Printer, 13 ... Paper, 14 ... Paper tray, 16,17 ... Paper feed roller, 18 ... Paper discharge roller, 19,20,21 ... Pressing roller,
23 ... Swing arm, 24 ... Paper feed roller, 26 ... Paper feed drive motor, 29 ... Abutment bar, 35 ... Cam part, 37 ... Selection gear, 38 ... Cam plate, 39 ... Drive gear, 40 ... Pressing side gear , 41 ... Separation side gear, 42 ... Rotating plate.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B65H 29/20

Claims (1)

[Scope of utility model registration request] 1. A paper feed roller for picking up predetermined paper sheets one by one is rotatably driven by a paper feed drive motor inside a printer body, and the paper conveyed by the paper feed roller is placed at a predetermined printing position. In a paper feeding mechanism of a printer, which is provided with a paper feeding roller for carrying and a pressure contact roller which is in pressure contact with the paper feeding roller, and a paper discharging roller for discharging the paper after printing, A clutch mechanism for rotating the paper feed roller only in a predetermined paper feed direction is connected to the roller, and the pressure contact roller is brought into pressure contact with the paper feed roller by rotation of the paper feed drive motor in the paper feed direction. A paper feed mechanism for a printer, characterized in that a roller contact / separation mechanism for separating the paper feed roller from the paper feed roller by disposing the paper drive motor in the opposite direction is provided.