JPH10157865A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer in which a paper feeding roller can convey a paper sheet stably. SOLUTION: A printer is provided with a paper supply roller 10, a paper feed roller 20, a single driving motor 9 driving the paper supply roller 10 and the paper feed roller 20, a transmission mechanism 11 used for transmitting the driving force of the driving motor 9 to the paper supply roller 10 and the paper feed roller 20, a contacting/separating means 19 moving the paper supply roller 20 to either of the contact position and the separation position selectively, and a control means 31 performing varied kind of control. The control means 31 is provided with a control unit, and by means of the control unit, the paper supply roller 20 is kept in the separation position after the tip of the paper sheet P is brought into contact with the paper feed roller 20 when the paper sheet P is fed with the paper feed roller 20 kept rotating reversely, and then, the paper supply roller 20 is rotated normally so as to convey the paper sheet P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer,
In particular, the present invention relates to a printer capable of performing stable paper feeding toward a recording position.

[0002]

2. Description of the Related Art In general, various types of printers such as a thermal transfer printer and a page printer used as output devices such as a computer, a word processor and a facsimile store a plurality of sheets when desired recording is performed. A paper cassette provided with a separation mechanism is mounted on the printer body, and the paper placed on the paper mounting table of the paper cassette is brought into contact with a rotating paper feed roller. Separately, feed the paper to the paper feed roller located before the recording position of the printer,
When the leading end of the paper in the transport direction reaches the paper feed roller, the transport of the paper is taken over by the paper feed roller. The paper feed roller and the paper feed roller are formed so as to be able to rotate the driving force of the drive motor with a transmission mechanism constituted by a group of gears.

[0003]

However, in the above-described conventional printer, when recording is performed, the paper is conveyed while both the paper feed roller and the paper feed roller are rotating in the direction in which the paper is conveyed. Since the paper feed roller is configured to carry over the paper, both the transport force of the paper feed roller and the transport force of the paper feed roller are applied to the paper. However, there is a problem that a load due to the paper feed roller may impede the conveyance of the paper by the paper feed roller and stable paper feed may not be performed.

Further, a paper feed roller and a paper feed roller are
In the case of driving each by a separate drive motor, two transmission mechanisms for driving the paper feed roller and the paper feed roller are required, which not only imposes a large economic burden but also reduces the size and weight in recent years. There is a problem that it becomes a hindrance factor for the development.

The present invention has been made in view of these points, and a single drive motor drives a paper feed roller and a paper feed roller, and can stably convey paper by the paper feed roller. It is intended to provide a printer.

[0006]

According to a first aspect of the present invention, there is provided a printer according to the present invention, which is capable of abutting a sheet mounting table via a sheet. A paper feed roller for separating the paper one by one from the mounting table and feeding the paper, a paper feed roller for conveying the paper fed by the paper feed roller, and a drive roller for driving the paper feed roller and the paper feed roller One drive motor, a transmission mechanism for transmitting the driving force of the drive motor to the paper feed roller and the paper feed roller, and a contact position where the paper feed roller abuts on the paper mounting table via paper. A contacting / separating means for moving the position of the paper feed roller so as to selectively take one of two positions, ie, a separation position where the paper feed roller is separated from the paper mounting table, and a control means for controlling various controls And having The control means feeds the paper by the paper feed roller in a state where the paper feed roller is reversely rotated in a direction opposite to the direction in which the paper is transported, and the leading end of the fed paper is fed to the paper feed roller. After the contact, the contact / separation means holds the paper feed roller at a separated position separated from the paper table, and moves the paper feed roller in a direction in which the paper is conveyed while holding the paper feed roller at the separated position. A control unit for driving the paper feed roller, the paper feed roller, the drive motor, the transmission mechanism, and the contact / separation means so that the paper is conveyed by the paper feed roller while being rotated forward. . By adopting such a configuration, the paper feed roller and the paper feed roller can be driven by one drive motor, and the load of the paper feed roller is applied to the paper when the paper is transported by the paper feed roller. Can be prevented from being transmitted.

According to a second aspect of the present invention, there is provided a printer according to the first aspect, wherein the contacting / separating means is provided on a sheet feeding roller driving shaft for rotating the sheet feeding roller. And a cam surface which is fixedly arranged so that the cam lever can come and go. By adopting such a configuration, one of two positions, a contact position where the paper feed roller abuts on the paper mounting table via the paper and a separation position where the paper feed roller is separated from the paper mounting table, is provided. The position of the paper feed roller can be reliably moved so as to selectively take one of them.

According to a third aspect of the present invention, there is provided a printer according to the first or second aspect of the present invention, wherein the paper feed roller is always at one position regardless of the rotation direction of the drive motor. And the paper feed roller is formed such that the rotation direction is controlled by the rotation direction of the drive motor. By adopting such a configuration, the paper feed roller can be stopped when the paper is conveyed by the paper feed roller.

According to a fourth aspect of the present invention, there is provided a printer according to any one of the first to third aspects, wherein the transmission mechanism is configured such that the paper feed roller includes The point is that the paper feed roller of the drive motor is formed so as not to transmit the rotation of the drive motor in the direction of transporting the paper to the paper feed roller when held at the separated position.
By adopting such a configuration, it is possible to prevent the driving force of the drive motor from being transmitted to the paper feed roller when the paper is conveyed by the paper feed roller.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

FIGS. 1 to 7 show an embodiment of a printer according to the present invention. FIG. 1 is a structural view showing a main part of the overall structure, and FIG. 2 is a perspective view showing a main part of a transmission mechanism. FIG. 3 is a plan view of a main part of the transmission mechanism, FIG. 4 is a side view of the main part of FIG. 3, FIG. 5 is a front view showing a main part near the rocking plate, and FIG. FIG. 7 is a plan view showing a main part of the swing plate, and FIG. 7 is a block diagram showing a main part of the control means.

As shown in FIG. 1, a printer 1 according to the present embodiment is configured to convey a sheet P substantially horizontally to perform recording, and a printer P disposed inside a printer case (not shown). It has a frame 2. On the printer frame 2, a platen 3 having a flat plate shape has a recording surface 3a.
Are arranged upward so as to be parallel to the paper feed direction, which is the transport direction of the paper P indicated by the arrow A in FIG. Above the platen 3, a recording head is arranged as a recording head in which a plurality of heating elements (not shown) that face the platen 3 and that can be freely moved toward and away from the platen 3 by a known driving mechanism (not shown). A thermal head 4 is provided. The contact position between the thermal head 4 and the platen 3 in the head-down state (not shown, FIG. 1 shows the head-up state) in contact with the platen 3 is the recording position PP. In addition, between the platen 3 and the thermal head 4, in order from the platen 3 side,
Paper P and an ink ribbon (not shown) are supplied.

The thermal head 4 is driven by a suitable carriage motor (not shown) such as a stepping motor so that the thermal head 4 is perpendicular to the paper feeding direction, which is the direction of transport of the paper P shown by the arrow A in FIG. The carriage 5 is mounted on a known carriage 5 which is reciprocally movable (in the direction perpendicular to the paper surface) along the recording surface 3a of the platen 3. The carriage 5 is coated with ink of a desired color on a base film. A known ribbon cassette (both not shown) having an ink ribbon inside can be mounted.

An obliquely lower right part of the carriage 5 is provided with an engaging portion (not shown) to which a known sheet cassette 6 (only a part is shown) is engaged via an opening (not shown). A cassette mounting section 7 is provided.

A paper feed roller 10 is provided above the cassette mounting section 7 so as to face a friction pad 8 provided on the paper feed cassette 6. As shown in FIG. 1, the paper feed roller 10 is configured to be rotationally driven by transmitting a driving force of a drive motor 9 via a transmission mechanism 11 described later. As shown in detail in FIG. 2, the paper feed roller 10 has a substantially D-shaped cross section.
A plurality of paper feed rollers 10 are fixed to the paper feed roller drive shaft 12 at appropriate intervals. This feed roller drive shaft 1
2 is urged toward the sheet cassette 6 by an appropriate urging member 13 such as a torsion coil spring. And
A cam lever 14 is attached to one end of the feed roller drive shaft 12, as shown in FIGS. The cam lever 14 is, as shown in FIG.
2 and a substantially cylindrical base 15 attached to the base 1
5 and a lever body 16 extending radially outward from the outer peripheral surface of the lever 5. Then, the lever body 16 of the cam lever 14
Is fixedly arranged below the cam lever 14, and in this embodiment, can be brought into contact with and separated from a substantially L-shaped cam surface 17 (FIG. 4) fixedly arranged on the printer frame 2.

That is, the paper feed roller 10 is driven by the rotation of the drive motor 9 to move the lever body 1 of the cam lever 14.
The leading end of the roller 6 rotates and comes into contact with or separates from the cam surface 17, and as a result, the paper feed roller 10 is formed so as to be able to move up and down so as to move toward and away from the paper feed cassette 6 as shown by a double-headed arrow B in FIG. Have been.

In addition, the tip of the lever body 16 of the cam lever 14 is always in contact with the cam surface 17,
As shown by a broken line in FIG. 1, the sheet P is located at a separated position upwardly separated from the sheet table 18 on which the sheet P of the sheet cassette 6 is placed, and is placed on the sheet table 18 of the sheet cassette 6 ( Only when the sheet P located at the uppermost position of the stored sheet P is sent toward the recording position PP, the tip of the lever body 16 of the cam lever 14 separates from the cam surface 17 as shown by a solid line in FIG. The sheet P is placed at a contact position where it descends so as to be in pressure contact with the upper surface of the sheet P located on the top of the sheet P placed in the sheet feeding cassette 6 and contacts the sheet placing table 18 via the sheet P. The sheet P is formed so that the sheet P can be sent out.

That is, the paper feed roller 10 is selectively positioned at one of two positions: a contact position where the paper P is in contact with the paper table 18 and a separated position that is separated from the paper table 18. It is formed so that.

A contact / separation means for moving the sheet supply roller 10 of this embodiment so as to selectively take one of two positions, a contact position and a separation position, by the cam lever 14 and the cam surface 17. 19 (FIG. 4). Further, the contact / separation means 19 is formed so as to be driven in conjunction with the transmission mechanism 11.

Returning to FIG. 1, the paper P sent from the paper feed cassette 6 by the paper feed roller 10 is received upstream of the recording position PP in the paper feed direction indicated by the arrow B, and is recorded at a predetermined speed. A paper feed roller 20 and a guide 21 for transporting to the position PP are provided. As shown in FIG. 3, the paper feed roller 20 has a substantially circular cross section, and a plurality of paper feed rollers 20 are fixed to the paper feed roller drive shaft 22 at appropriate intervals. The paper feed roller 20 is rotatably driven by a drive motor 9 for driving the paper feed roller 10, and the paper feed roller 2 is provided above each paper feed roller 20.
An auxiliary roller 23 that is in contact with the outer peripheral surface of the roller 0 is rotatably disposed. The auxiliary roller 23 is a paper feed roller 2
0.

That is, the sheet P separated from the sheet feeding cassette 6 and fed by the sheet feeding roller 10 is moved to the recording position P
The recording position PP is transferred to the paper feed roller 20 and the auxiliary roller 23 constituting the paper feed mechanism before P, and is sandwiched between the paper feed roller 20 and the auxiliary roller 23.
It is possible to travel toward.

When the traveling of the paper P is transferred from the paper feed roller 10 to the paper feed roller 20, the paper P descends so as to come into pressure contact with the upper surface of the paper P located at the uppermost position of the paper P, and moves to the contact position The feeding roller 10 that is operating is
8 so as to return to a separated position separated therefrom.

In the vicinity of the paper feed roller 20, a known sensor used for detecting the presence or absence and the position of the paper P is provided.

On the downstream side (left side in FIG. 1) of the paper feed direction indicated by arrow A from the recording position PP, a paper discharge roller 24 for discharging the paper P on which recording has been completed is disposed.
The paper discharge roller 24 is driven to rotate by the drive motor 9, and above the paper discharge roller 24,
A pressure roller (not shown) that is in contact with the outer peripheral surface of the paper discharge roller 24 is rotatably disposed, and the pressure roller is driven to rotate by the paper discharge roller 24.

That is, the paper P on which the recording has been performed is discharged to the outside so as to be sandwiched between the paper discharge roller 24 and the pressing roller.

The transmission mechanism 11 will be described in detail.

As shown in FIG. 2, the transmission mechanism 11 of the present embodiment has a main gear 25 to which the rotational driving force of the driving motor 9 such as a stepping motor is transmitted. The transmission path of the rotational driving force of the drive motor 9 to the main gear 25 in the present embodiment is, as shown in FIG. 2, a pinion 26 attached to an output shaft 9a of the drive motor 9 and a paper feed roller drive shaft. One end of 22 (left side in Fig. 1)
And a paper feed roller drive gear 27 attached to the gears via an idle gear 28 which is a two-stage gear.
An output gear 29 attached to the other end (right side in FIG. 1) of the paper feed roller drive shaft 22 and the main gear 25 are meshed via an idle gear 30.

That is, the drive motor 9 and the main gear 25
The paper feed roller 20 is formed so as to rotate in the same direction as the rotation direction of the drive motor 9.

The drive motor 9 is electrically connected to the control means 31, and the drive motor 9 is connected to the control means 31.
The rotation direction and the like are controlled based on a control command sent from the computer. As shown in FIGS. 2 to 5 which will be described in detail later, a small-diameter sub gear 32 which rotates integrally with the main gear 25 is formed coaxially on one surface of the main gear 25. As shown in detail in FIG. 5, a swinging plate 3 is mounted on a main gear support shaft 33 that rotatably supports the main gear 25.
4 is rotatably attached to face the sub gear 32. As shown in detail in FIG. 6, the swing plate 34 has a base portion 35 formed substantially in a link shape, and a surface of the base portion 35 opposite to the surface facing the sub gear 32 (the right side in FIG. 5). (The left side in FIG. 5). As shown in FIGS. 5 and 6, the abutting body 36 is wider than the base portion 35 and has a substantially sector shape in which the distal end outer surface shown in the upper part of FIG. 6 projects outside the outer peripheral surface of the base portion 35 shown in the upper part of FIG. Is formed. As shown in FIG. 5, a through hole 37 penetrating in the plate thickness direction is formed in the vicinity of the lower end portion shown in the lower part of FIG. Is inserted. Further, as shown in FIG.
In the vicinity of the upper end shown in the upper part of FIG.
A protruding end is provided so as to face the main gear 25, and a swinging gear that always meshes with the sub gear 32 is provided at the tip of the swinging gear support shaft 38, as shown in detail in FIG. 5. A gear 39 is rotatably supported.

That is, the swing plate 34 is connected to the main gear 25.
The swing gear 39 is formed so as to be rotatable around the main gear support shaft 33 with the rotation of the swing gear 34, and is rotatably attached to the tip end of the swing plate 34. The outer peripheral surface of the sub gear 32 is formed so as to revolve around the main gear support shaft 33.

As shown in FIGS. 2 to 4, on the revolving locus of the swing gear 39, the swing range (swing angle) of the swing gear 39 about the main gear support shaft 33 is regulated. As described above, the transmission gear 40 meshable with the swing gear 39 with the rotation of the swing plate 34 in the counterclockwise direction in FIG.
In FIG. 3, the swing gear 39 and the intermediate gear 41 that can be engaged with the swing gear 39 are rotatably disposed as the swing plate 34 rotates clockwise in FIG.

The transmission gear 40 is meshable with the swing gear 39 at a gear ratio of 1: 1 and has a small toothless portion 42a (FIG. 4) having no teeth formed in a part thereof. The gear section 42 is provided. The small gear portion 42 has a substantially cylindrical connecting body 44 formed coaxially with the small gear portion 42 and having a smooth outer peripheral surface 43 on one surface shown on the left side of FIG.
One end of the abutting member 36 is connected to the smooth portion 43. A left side surface of the contact body 36 of the swing plate 34 shown in FIG. Can be contacted.

That is, a smooth portion 43 is formed in a part of the transmission gear 40 so that a part of the swing plate 34 can abut.
By contacting the front end side of the left side of the contact body 36 of the swing plate 34 with the smooth portion 43, the swing gear 39 and the transmission gear 4
0, the distance between the axes of the swing gear 39 and the transmission gear 40 when the transmission gear 40 meshes with the swing gear 39 is appropriately controlled.
Can be reliably and appropriately maintained in the engaged state.

At the other end of the connecting member 44 of the transmission gear 40, a large gear portion 45 formed coaxially with the small gear portion 42 and integrally rotating with the small gear portion 42 is provided. In the present embodiment, the number of teeth of the large gear portion 45 is twice the number of teeth of the small gear portion 42, and
The paper feed roller driving gear 46 for transmitting a rotational driving force to the paper feed roller 10 is provided so as to always mesh with the paper feed roller 10.

That is, when the swinging plate 34 rotates counterclockwise in FIG. 4 and the swinging gear 39 meshes with the small gear portion 42 of the transmission gear 40, the transmission gear 40 It is formed so as to transmit the rotational driving force to the transmission gear 40.

The intermediate gear 41 has a first gear portion 47 which can mesh with the swing gear 39. This first gear portion 4
7, one end of a substantially cylindrical coupling body 49 formed coaxially with the first gear portion 47 and having an outer peripheral surface formed as a smooth portion 48 and having an outer dimension smaller than the root circle of the first gear portion 47. Is connected to the abutting member 36 of the swing plate 34 as the swing plate 34 rotates clockwise in FIG.
6 comes into contact with the right side surface shown on the right side of FIG.

That is, a smooth portion 48 is formed in a part of the intermediate gear 41 so that a part of the swing plate 34 can abut.
By contacting the front end of the right side of the contact body 36 of the swing plate 34 with the smooth portion 48, the swing gear 39 and the intermediate gear 4
1 is properly controlled so that the distance between the axes of the oscillating gear 39 and the intermediate gear 41 when the first gear meshes with the first oscillating gear 39 is adjusted.
Can be reliably and appropriately maintained in the engaged state.

The other end of the connecting member 49 has a first gear 4
7, a second gear portion 50 having the same shape and rotating integrally with the first gear portion 47 is provided. The second gear portion 50 is disposed so as to always mesh with the large gear portion 45 of the transmission gear 40.

That is, when the swing plate 34 rotates clockwise in FIG. 4 and the swing gear 39 meshes with the first gear portion 47 of the intermediate gear 41, the intermediate gear 41 It is formed so as to transmit the rotational driving force to the transmission gear 40.

The small gear portion 42 of the transmission gear 40 and the first gear portion 47 of the intermediate gear 41, with which the swing gear 39 selectively meshes, are arranged close to each other.

The control means 31 controls the operation of each part of the printer 1 and, as shown in FIG.
51, a memory 52 formed of ROM, RAM or the like having an appropriate capacity, a controller 53, and the like. The control unit 31 controls the paper feed roller 10 to rotate the paper P at least in a state where the paper feed roller 20 is reversely rotated in a direction opposite to the direction in which the paper P is transported as indicated by an arrow A in FIG. After the sheet P is fed, and the leading end of the fed sheet P comes into contact with the paper feed roller 20, the sheet feeding roller 10 is held at the separated position by the contacting / separating means 19, and the sheet feeding roller 10 is moved to the separated position. The paper feed roller 10 is configured to rotate the paper feed roller 10 forward in the forward direction for transporting the paper P indicated by an arrow A in FIG. 10, paper feed roller 20, drive motor 9, transmission mechanism 17, and contact / separation means 19
Has a control unit 54 in which a program for driving is stored.

That is, the control means 31 controls the drive motor 9
By controlling the rotation direction, the swing gear 39 can be controlled to selectively mesh with either the transmission gear 40 or the intermediate gear 41.

The drive motor 9, the main gear 25 and the paper feed roller drive gear 27 are arranged on the same side, and the pinion 26 attached to the output shaft 9a of the drive motor 9 directly meshes with the main gear 25. It may be. In this case, the paper feed roller drive gear 27 may be directly meshed with the main gear 25, or may be meshed with the main gear 25 via an idle gear (not shown).

Next, the operation of the present embodiment having the above-described configuration will be described with reference to FIG.

FIG. 8 is a flowchart showing an embodiment of the recording operation of the printer according to the present invention.

In the recording operation for recording on the paper P by the printer 1 according to the present embodiment, first, in step ST01, the control unit 31, specifically, the control unit 5 of the control unit 31
The process starts by driving the drive motor 9 based on the control command sent from the control unit 4. The rotational driving force of the drive motor 9 is transmitted to a paper feed roller drive gear 27 attached to one end of the paper feed roller drive shaft 22 via a pinion 26 and an idle gear 28, and the paper feed roller 20 is driven by the drive motor 9. Rotate in the same direction as the rotation direction. The rotational driving force of the drive motor 9 transmitted to the paper feed roller drive shaft 22 is output from an output gear 29 attached to the other end of the paper feed roller drive shaft 22, and is output via the idle gear 30 to the main gear. The main gear 25 is rotated in the same direction as the rotation direction of the drive motor 9.

That is, when the drive motor 9 is viewed clockwise as viewed from the side opposite to the output shaft 9a in the direction in which the sheet P is transported (FIG. 4).
Clockwise). Then, the paper feed roller 20
Rotates in the forward direction for transporting the paper P,
Rotates clockwise in FIG. The clockwise rotation of the main gear 25 rotates the small-diameter sub gear 32 that rotates integrally with the main gear 25 in the clockwise direction in FIG. 4, and moves the swing plate 34 about the main gear support shaft 33 in FIG. By rotating clockwise, the swing gear 39 and the first gear portion 47 of the intermediate gear 41 mesh with each other. Then, the intermediate gear 41 rotates clockwise, and the intermediate gear 41 rotates.
The large gear portion 45 of the transmission gear 40 meshing with the second gear portion 50 is rotated in the counterclockwise direction in FIG. 4, and the feed roller driving shaft 1 meshed with the large gear portion 45 of the transmission gear 40 is rotated.
The drive force of the drive motor 9 is transmitted to the drive gear 2 via the intermediate gear 41. As a result, the paper feed roller 10 attached to the paper feed roller drive shaft 12 rotates clockwise in FIG. It is set so as to be in contact with the surface 17 and to be located at a separated position indicated by a broken line in FIG. Thus, an initialization operation is performed.

Next, in step ST02, a sensor (not shown) detects the presence or absence of the paper P, and if YES (the paper is present near the paper feed roller 20: the paper P is inside the printer 1), the process proceeds to step ST02. The process proceeds to ST08 to discharge the sheet.

If the determination in step ST02 is NO (there is no paper P near the paper feed roller 20: there is no paper P inside the printer 1), the process proceeds to the next step ST03.

Next, in step ST03, the drive motor 9 is rotated in the reverse direction. That is, the drive motor 9 is rotated in the clockwise direction when viewed from the opposite side of the output shaft 9a opposite to the direction in which the sheet P is transported. Then, the paper feed roller 20
Rotates in the direction opposite to the direction in which the sheet P is transported, and the main gear 25 rotates counterclockwise in FIG. The rotation of the main gear 25 in the counterclockwise direction rotates the small-diameter sub gear 32 that rotates integrally with the main gear 25 in the counterclockwise direction in FIG. 4 and moves the swing plate 34 about the main gear support shaft 33. 4, the counterclockwise rotation is performed, and the swing gear 39 and the small gear portion 42 of the transmission gear 40 are rotated.
And mesh with each other. Then, the transmission gear 40 connected to the sub gear 32 via the swing gear 39 rotates counterclockwise,
The driving force of the driving motor 9 is transmitted to the sheet feeding roller driving shaft 12 meshing with the large gear portion 45 of the transmission gear 40. Thus, the paper feed roller 10 attached to the paper feed roller drive shaft 12 rotates clockwise in FIG. 4, that is, in a direction in which the paper P can be transported. Thereby, the paper feed roller 1
Reference numeral 0 denotes a position where the leading end of the lever body 16 of the cam lever 14 constituting the contact / separation means 19 which rotates together with the rotation is separated from the cam surface 17 and is located at the contact position shown by a solid line in FIG. Abuts on the sheet P, and the sheet P is fed.

That is, according to the transmission mechanism 11 of the present embodiment, regardless of the rotation direction of the drive motor 9, the paper P on which the paper feed roller 10 is always mounted on the paper mounting table 18 of the paper feed cassette 6 is always transferred. It can be rotated in a fixed direction, that is, in a paper feeding direction.

Next, in step ST04, when the leading end of the sheet P fed from the sheet placing table 18 reaches the contact portion between the sheet feed roller 20 and the auxiliary roller 23,
The paper P collides with the paper feed roller 20 that is rotating in the reverse direction to the paper feed direction in which the paper P is transported, and the leading end of the paper P located at the head of the paper feed direction is aligned parallel to the paper feed roller 20. Then, paper attitude control is performed.

Next, in step ST05, the leading end of the paper P fed to the paper feed roller 20 is abutted and the paper P is brought into contact with the paper feed roller 20 and the auxiliary roller 23.
At the timing when the tips of
The tip end of the lever body 16 of the cam lever 14 abuts against the cam surface 17 again to return the paper feed roller 20 to the separated position shown by the broken line in FIG. The driving force of the drive motor 9 is not transmitted to the paper feed roller 10, and the rotation of the paper feed roller 10 is stopped, being located at the toothless portion 42 a of the small gear portion 42 of the transmission gear 40.

Next, in step ST06, when the drive motor 9 is rotated forward again, only the paper feed roller 9 whose rotation direction is controlled by the rotation direction of the drive motor 9 rotates forward, and the leading ends are aligned in parallel. The sheet P thus conveyed is conveyed toward the recording position PP, and cueing of the sheet P is performed.

Next, in step ST07, only the paper feed roller 9 rotates forward to repeat the paper feed accompanying the line feed operation required for recording.

Next, in step ST08, the sheet is discharged, and when the end of the sheet P passes through a sensor (not shown) and the sensor detects the sheet P, the drive motor 9 stops.

Next, in step ST09, when the paper P is discharged, the drive motor 9 is rotated in the reverse direction, and then the drive motor 9 is rotated in the forward direction, so that the swing gear mounted on the swing plate 34 is rotated. 39 and the transmission mechanism 1
1 toothless portion 42 of the small gear portion 42 of the transmission gear 40
The swing gear 39 located at the position a is separated from the toothless portion 42a.

Next, in step ST10, it is determined whether or not recording is continuously performed on the sheet P. If YES (recording operation is continued), the process returns to step ST02, and NO
In the case of (no recording operation), the driving motor 9 is stopped and the processing ends.

Therefore, according to the printer 1 of the present embodiment, when the paper feed roller 20 conveys the paper, the paper P whose paper posture is controlled is conveyed without applying a load to the paper feed roller 10. Therefore, the paper P can be properly and stably conveyed by the paper feed roller 20.

According to the printer 1 of the present embodiment, one driving unit is controlled by a simple configuration in which the rotation direction of the driving motor 9 is controlled based on a control command sent from the control unit 54 of the control unit 31. The paper feed roller 10, the paper feed roller 20, and the paper discharge roller 24 can be easily driven by the driving force of the motor 9.

Further, according to the printer 1 of the present embodiment, the feed roller driving shaft 1 for driving the feed roller 10 to rotate.
The paper feed roller 10 is brought into contact with the paper table 18 via the paper P by a simple configuration in which the cam lever 14 disposed on the paper 2 is moved toward and away from the fixed cam surface 17. The position of the paper feed roller 10 can be easily and surely moved so as to selectively take any one of two positions, ie, the separation position where the roller 10 is separated from the paper mounting table 18.

Further, according to the printer 1 of the present embodiment, when the swing gear 39 meshes with the small gear portion 42 of the transmission gear 40, the tip of the left side surface of the contact body 36 of the swing plate 34 is moved. When the swing gear 39 meshes with the first gear portion 47 of the intermediate gear 41, the swing plate 3 is brought into contact with the smooth portion 43 of the transmission gear 40.
4 has a simple structure in which the front end side of the right side of the contact body 36 is brought into contact with the first gear portion 47 of the intermediate gear 41.
When the gear 9 and the transmission gear 40 mesh with each other, the distance between the axes of the swing gear 39 and the transmission gear 40, the meshing state between the swing gear 39 and the transmission gear 40, and the swing gear 39 and the intermediate gear 41 Since it is possible to easily and surely and properly maintain the distance between the axes of the swing gear 39 and the intermediate gear 41 at the time of engagement and the meshing state between the swing gear 39 and the intermediate gear 41, the swing gear 39 It is possible to prevent generation of abnormal noise and abnormal wear of the teeth when the transmission gear 40 or the intermediate gear 41 is meshed improperly, and to maintain a stable function for a long period of time.

Further, according to the printer 1 of the present embodiment, when the swing gear 39 swings between the transmission gear 40 and the intermediate gear 41, the swing gear 39 is moved between the transmission gear 40 and the intermediate gear 41. Do not mesh with any of the paper feed rollers 10
Since the paper feed roller 20 alone can be rotated without rotating the gear, the control means 31 controls the swing gear 39 at a predetermined timing while the swing gear 39 swings between the transmission gear 40 and the intermediate gear 41. By sending the command, the paper P
Of paper P that conveys the paper P in the direction opposite to the paper feed direction. By the back feed of the paper P, fine adjustment of the recording start position on the paper P can be performed according to the user's preference.

In the present embodiment, the small gear portion 42 of the transmission gear 40 that can mesh with the swing gear 39 and the first gear portion 47 of the intermediate gear 41 are arranged close to each other. The angle at which the dynamic gear 39 swings between the small gear portion 42 of the transmission gear 40 and the first gear portion 47 of the intermediate gear 41 is increased, so that the paper P of about 1 to 2 inches can be back-fed. can do.

That is, by increasing the angle at which the swing gear 39 swings between the small gear portion 42 of the transmission gear 40 and the first gear portion 47 of the intermediate gear 41, the back feed amount of the paper P is increased. You can also.

It should be noted that the present invention is applicable to the case where the paper feed cassette 6 is attached to the printer frame 2, that is, the paper P
Of course, the present invention can also be applied to a case where the storage part is integrated with the printer 1.

The present invention is not limited to the above embodiment, but can be modified as required.

[0068]

As described above, according to the printer of the present invention, with a simple structure, the paper feed roller and the paper feed roller are driven by the driving force of one drive motor, and the paper is transported by the paper feed roller. Can be performed stably.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a main part of an overall configuration of an embodiment of a printer according to the invention.

FIG. 2 is a perspective view showing a main part of a transmission mechanism.

FIG. 3 is a plan view showing a main part of the transmission mechanism.

FIG. 4 is a side view of a main part of FIG. 3;

FIG. 5 is a front view showing a main part near the rocking plate;

FIG. 6 is a plan view showing a main part of the rocking plate.

FIG. 7 is a block diagram showing a main part of a control unit.

FIG. 8 is a flowchart showing an embodiment of a recording operation of the printer according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 printer 9 drive motor 10 paper feed roller 11 transmission mechanism 12 paper feed roller drive shaft 14 cam lever 16 lever body 17 cam surface 18 paper mounting table 19 contacting / separating means 20 paper feed roller 31 control means 54 control unit A paper feed direction P paper PP recording position

Claims (4)

[Claims] A sheet feed roller which can be brought into contact with a sheet mounting table via a sheet and separates and feeds the sheets from the sheet mounting table one by one; and a sheet fed by the sheet feeding roller. A paper feed roller for conveying, one drive motor for driving the paper feed roller and the paper feed roller, and a transmission mechanism for transmitting the driving force of the drive motor to the paper feed roller and the paper feed roller; The paper feed roller selectively takes one of two positions, a contact position where the paper feed roller is in contact with the paper mounting table via paper, and a separation position where the paper feed roller is separated from the paper mounting table. A contact unit that moves the position of the paper feed roller, and a control unit that controls various controls, wherein the control unit reversely rotates the paper feed roller in a direction opposite to a direction in which the paper is conveyed. To the paper feed roller After the leading edge of the fed paper comes into contact with the paper feed roller, the contact / separation means holds the paper feed roller at a separated position separated from the paper mounting table. The paper feed roller, the paper feed roller, the drive motor, and the like, so that the paper feed roller is rotated forward in the direction in which the paper is transported while the paper roller is held at the separated position and the paper is transported by the paper feed roller. A printer comprising a control unit for driving a transmission mechanism and a contact / separation unit. 2. The contact / separation means includes a cam lever provided on a paper feed roller drive shaft for driving the paper feed roller to rotate, and a fixedly disposed cam surface to which the cam lever can come and go. The printer according to claim 1, wherein: 3. The paper feed roller is always rotated in one direction irrespective of the rotation direction of the drive motor, and the paper feed roller is formed such that the rotation direction is controlled by the rotation direction of the drive motor. The printer according to claim 1, wherein the printer is operated. 4. The transmission mechanism prevents the rotation of the drive motor in the direction in which the paper feed roller conveys the paper from being transmitted to the paper feed roller when the paper feed roller is held at the separated position. The printer according to any one of claims 1 to 3, wherein the printer is formed.