JP3186828B2 - Printer paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having an automatic paper feeder , and more particularly to a printer for correcting skew of recording paper.
To a printer paper feeder.

[0002]

2. Description of the Related Art As a conventional paper feeding method of a printer, a method disclosed in Japanese Patent Publication No. 58-6633 is known. This will be described below with reference to FIGS.

[0003] A pinch roller 2 for pressing the recording paper 6 against the outer peripheral surface of the platen 1 is provided near the lower side of the platen 1 on the printer body side. Recording paper detecting means 4 for determining the presence or absence of paper is provided.

On the automatic paper feeder side, a paper feed roller 5 that separates and transports the recording paper one by one and is located between the printer main body and the automatic paper feeder, and relays the transport of the recording paper 6. The paper feed auxiliary roller 3 and the auxiliary driven roller 10 are provided.

Next, the operation of the paper feed system will be described. In the following description, the normal rotation is a rotation for carrying the operation of transporting the recording paper 6 from the automatic paper feeder toward the print head 8, and the reverse rotation is an operation in the opposite direction. The rotation to be performed. While the platen 1 is rotating in the reverse direction, the paper feed roller 5 rotates forward, separates the recording paper 6 and transports it to the paper feed auxiliary roller 3. The recording paper 6 is pressed between the paper feed auxiliary roller 3 and the auxiliary driven roller 10 and is conveyed to the printer body. The leading edge of the recording paper 6 is aligned by applying the leading end of the recording paper 6 to a pressure contact portion between the platen 1 and the pinch roller 2 in a state where the platen 1 is rotated in the reverse direction.
Then, the sheet feeding operation is completed by rotating the platen 1 forward to convey the recording paper 6 to the printing start position.

On the other hand, the paper feeding operation disclosed in Japanese Patent Application Laid-Open No. 57-189951 will be described with reference to FIGS. In these figures, parts common or corresponding to those in FIGS. 9 and 10 showing the above-described conventional example are denoted by the same reference numerals, and description of the common parts will be omitted.

First, the recording paper 6 conveyed from the automatic paper feeder
Is held between the platen 1 and the pinch roller 2 pressed by the platen 1 while the platen 1 is rotating forward. Then, after the recording paper 6 has passed the pinch roller 2, the leading end of the recording paper 6 is recognized by the recording paper detection means 4 located below the platen 1, and then the automatic paper feeder is stopped. Next, the platen 1 is reversed, and the leading edge of the recording paper 6 is extruded from the pinch roller 2 to the automatic paper feeder side to bend the recording paper 6 and align the leading edges. Then, there is a paper feeding method in which the platen 1 is rotated forward again to convey the recording paper 6 to the printing start position.

[0008]

[Problems to be solved by the invention]
In the conventional method of feeding paper from the automatic paper feeder to the printer main body disclosed in US Pat. No. 6,633, the tip of the recording paper 6 is applied to the pinch roller 2 while the pinch roller 2 is rotated in the reverse direction. Depending on the contact angle, there is a problem that the leading end of the recording paper 6 is rolled under the pinch roller 2 and the leading end is bent.

On the other hand, in the conventional method disclosed in Japanese Patent Application Laid-Open No. 57-189951, a paper feed roller is used as means for stopping the automatic paper feeder when the pinch roller 2 is rotated in the reverse direction to bend the recording paper 6. Since the one-way clutch was used for the drive unit of No. 5, it was very expensive. When bending the recording paper 6, the platen 1 and the pinch roller 2
Is performed only by the paper feed force at the time of reverse rotation of the paper.
However, there is a drawback that the recording paper slips during the reverse rotation, does not allow sufficient bending, and the leading ends of the recording paper are not aligned. Further, since a series of operations requires three steps of forward rotation, reverse rotation, and forward rotation of the platen 1, there is also a drawback that the paper feeding time becomes longer.

Further, if the recording paper detecting means is arranged as in the conventional Japanese Patent Application Laid-Open No. 57-189951, it is impossible to determine the presence or absence of the recording paper when the recording paper is manually inserted through the recording paper insertion opening of the printer main body. Therefore, the operability of the recording paper becomes very poor.

The present invention solves such a problem.
The purpose of this is to make
Can correct the skew of the recording paper very accurately.
To provide a new paper feeding device.

[0012]

Means for Solving the Problems That is, the present invention relates to
As a paper feeder for printers to achieve
Reverse rotation starts at the start of the paper, and the leading edge of the recording paper
Reached the paper feed auxiliary roller provided between the platen
At this point, it switches to forward rotation, and the recording paper is
When the pressure contact with the roller is reached,
After the recording paper is slightly advanced by the paper feed assist roller,
Drive gear that switches to reverse rotation and drive gear only during the last forward rotation
And the platen gear that meshes with the
And is pivotally supported at each end of a common trifurcated lever.
During forward rotation of the dynamic gear, it engages with the paper feed auxiliary gear to feed paper
A first planetary gear for transmitting rotation in the paper feed direction to the roller;
When the drive gear rotates in the reverse direction, the auxiliary gear feeds through the intermediate gear.
And transmits the rotation in the paper feed direction to the paper feed auxiliary roller.
Meshes with the second planetary gear and the paper feed gear to form a paper feed roller
Consists of a third planetary gear that transmits rotation in the paper feeding direction
It was done.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view of a main part of a printer main body and an automatic paper feeder according to an embodiment of the present invention. The automatic paper feeder as shown in FIG.
And a paper feed roller 5 for carrying out the recording paper 6 is provided at a lower end thereof. Further, a paper-supply auxiliary roller 3 is provided on the printer main body side with respect to the paper-supply roller 5, and the auxiliary driven roller 10 is pressed as an idle roller by the paper-supply auxiliary roller 3.

On the other hand, in the printer main body, a pinch roller 2 formed of an elastic member or plastic is pressed against a platen 1. Further, between the recording paper insertion slot 11 of the printer body and the pinch roller 2, a recording paper detecting means 4 for determining the presence or absence of recording paper is provided.

Next, a paper feeding operation based on the above components will be described. As shown in FIG. 2, first, the feed roller 5 is rotated forward (arrow b) by a driving device (described later) via a train of wheels (described later). Thereby, the recording paper 6 in the recording paper storage unit is separated one by one. The separated recording paper 6 is conveyed until the paper feed roller 5 rotates forward to bite the auxiliary paper feed roller 3 and the auxiliary driven roller 10. After a predetermined amount of the recording paper 6 has been fed, as shown in FIG. 3, when the paper feed auxiliary roller 3 is rotated forward, the recording paper detecting means 4 detects the leading end position of the recording paper 6. After detecting the leading edge of the recording sheet, the paper feed auxiliary roller 3 and the auxiliary driven roller 10 further rotate forward by a fixed amount to convey the recording sheet 6, and the platen 1 and the pinch roller 2 pressed by the platen 1 cut the leading end of the recording sheet 6. Let During the above operation, the platen 1 is always stopped.

Next, as shown in FIG.
Is further rotated forward by a fixed amount, the recording paper 6 is bent at the rear while the leading end of the recording paper is stopped at the point (d). Next, when a certain amount of deflection has occurred in the recording paper 6, the platen 1 is first rotated forward (arrow c) for the first time as shown in FIG. 5, and the recording paper 6 is conveyed to the printing start position.

The above-mentioned bending operation improves the biting of the leading end of the recording paper to the platen 1 when the recording paper 6 is conveyed to a predetermined printing position by finally rotating the platen 1 forward, and at the same time, This has the effect of aligning the inclination of the entire recording paper during separation. Since the above-described bending operation is performed, an appropriate minimum amount of bending on the recording paper 6 can be set irrespective of the thickness of the recording paper 6, and the forward rotation of the platen 1,
Since the three steps of reverse rotation and normal rotation are not required, the time required for bending can be greatly reduced.

Next, a wheel train for driving these rollers will be described with reference to FIGS.

A drive gear 14 driven by a drive motor (not shown) holds a platen gear 1g by a plunger or the like so as to be able to select between an engaged state and a retracted state. The first, second, and third planetary gears 1 integrally connected by a common lever 15 having a three-pronged shape.
6, 17 and 18 are engaged so as to roll on the circumference of the drive gear 14, and when the drive gear 14 rotates forward (rotation in the counterclockwise direction in the drawing), the rotation rotates in the counterclockwise direction. The forward rotation driving force is transmitted to the feed auxiliary gear 3g by the first planetary gear 16 that has turned (in the state of (b) and (d) in FIG. 6). The forward rotation driving force is transmitted to the sheet feeding gear 5g by the planetary gear 18 turned clockwise, while the forward rotation driving force is transmitted to the sheet feeding auxiliary gear 3g by the second planetary gear 17 via the idler 19. (States (a) and (c) of FIG. 6).

Therefore, at the time of starting paper feeding a (the state shown in FIG. 6A), the driving gear 14 is rotated in the reverse direction.
Second planetary gear 17 that has swung clockwise on the circumference of 4
Transmits the forward rotation driving force to the feed auxiliary gear 3g via the idler 19, and the third planetary gear 18 also feeds the feed gear 5g.
, And forwards the recording paper 6 by the paper feed roller 5.

When the leading edge of the recording paper 6 reaches the auxiliary paper feed roller 3 as the paper feeding operation proceeds, the drive motor switches to the normal rotation (the state shown in FIG. 6B). First planetary gear 1 that has turned on drive gear 14 in a counterclockwise direction in the figure.
Reference numeral 6 meshes with the feed auxiliary gear 3g to transmit the forward rotation driving force to the feed auxiliary roller 3. On the other hand, since the platen gear 1g is separated from the drive gear 1g, the platen 1 holds the stopped state. Then, at a time point c (a time point when the state shown in FIG. 6B is changed to the state shown in FIG. 6C), the recording paper 6 is conveyed to the base of the platen 1 and the leading end thereof is located at the pressing point between the platen 1 and the driven roller 2. After the collision, the drive motor rotates the drive gear 14 forward for a time t (FIG. 7). For this reason, as shown in FIG. 7, in the stage from the time point c to the time point d (the state of FIG. 6C), the second planetary gear 19 receives the normal rotation driving force via the idler 19. The paper feed auxiliary roller 3 further feeds out the recording paper 6 and forms a deflection L of the recording paper 6 between the platen 1 and the paper feed auxiliary roller 3, and the repelling force of the recording paper 6 itself causes the leading end of the recording paper 6 to become the platen 1. , The inclination of the recording paper 6 is removed.

When the time t has elapsed, the platen 1g is directly engaged with the driving gear 14 for the first time at the time point d, thereby rotating the platen 1 forward and pulling in the recording paper 6 (the state shown in FIG. 6D). At the same time, the recording paper 6 behind the leading end is made to follow by the paper feed auxiliary roller 3 that rotates forward at the same time.

As means for controlling the rotation of the platen 1, the paper feed auxiliary roller 3 and the paper feed roller 5, in addition to the present embodiment, a method of controlling engagement / disengagement of a train wheel using a plunger, A method using a plurality of independent driving motors can be applied.

With the above configuration and paper feeding method,
The flexing operation on the recording paper 6 can be performed at high speed and with high accuracy, and even when the leading end of the recording paper 6 comes into contact with the pinch roller 2 or the platen 1, the leading end of the recording paper 6 is stopped. There is an effect that the paper is not entangled and the accuracy of transporting the recording paper 6 to the printing start position is also improved.

Further, according to the present invention, by arranging the recording paper detecting means 4 in the above-described configuration, the recording paper detecting means 4 can be connected to the platen 1 of the paper path.
Since the recording paper is arranged further upstream, the presence or absence of the recording paper can be determined even when the recording paper is manually inserted, so that the operability of the recording paper is excellent.

[0027]

As described above , according to the present invention, the recording
When the leading edge of the paper reaches the pressure contact between the platen and the driven roller
To change from forward rotation to reverse rotation.
On the circumference of the drive gear, the planetary gear was rotated forward.
Is rotated forward by the second planetary gear that has revolved
And the leading edge of the recording paper falls between the platen and the driven roller.
After a short period of time has passed after stopping against the
By rotating the paper feed auxiliary roller, the leading edge of the recording paper
The recording paper from the back after correctly abutting the nip.
Nip at the leading edge of the recording paper.
Through secure contact and its correct deflection
Enables the paper to be oriented more correctly.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a main part of a printer main body and an automatic paper feeder according to an embodiment of the present invention.

FIG. 2 is a diagram showing a first stage of sheet feeding in the present invention.

FIG. 3 is a diagram showing a second stage of sheet feeding in the present invention.

FIG. 4 is a diagram showing a third stage of sheet feeding in the present invention.

FIG. 5 is a diagram showing a fourth stage of sheet feeding in the present invention.

FIG. 6 is a diagram showing a sheet feeding state and an operation of a train wheel in one embodiment of the present invention.

FIG. 7 is a diagram illustrating the position of a recording sheet and the operation of a sheet conveying unit according to an embodiment of the present invention.

FIG. 8 is a diagram illustrating a first-stage feeding state of recording paper in a conventional example.

FIG. 9 is a diagram illustrating a second-stage feeding state of recording paper in a conventional example.

FIG. 10 is a diagram illustrating a first-stage paper feeding state of recording paper in a conventional example.

FIG. 11 is a diagram showing a second-stage feeding state of recording paper in a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 platen 2 pinch roller 3 paper feed auxiliary roller 4 recording paper detecting means 5 paper feed roller 6 recording paper 7 automatic paper feeder 8 print head 9 recording paper storage unit 10 auxiliary driven roller 11 recording paper insertion slot

Claims (1)

(57) [Claims] A reverse rotation is started at the start of paper feeding, and the leading end of the recording paper is started.
An auxiliary paper feed roller whose end is provided between the paper feed roller and the platen
When the paper reaches
When the pressure contact between the platen and the driven roller is reached, reverse
And the paper feed auxiliary roller
A drive gear that switches to normal rotation after the recording paper is fed, and a platen gear that meshes with the drive gear only during the last normal rotation
And, in order to roll on the circumference of the driving gear, a common
Pivotally supported at each end of the lever, when the drive gear rotates forward
Is engaged with the paper feed auxiliary gear, and
A first planetary gear for transmitting rotation in a paper feed direction;
When the gear is rotated in reverse, the feed auxiliary gear is connected via the intermediate gear.
To transmit the rotation in the paper feed direction to the paper feed auxiliary roller.
A second planetary gear, and a paper feed gear.
From the third planetary gear that transmits rotation in the paper feed direction to the rollers
Become a printer paper feeder .