JP2919420B2 - Automatic paper suction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic paper suction apparatus, and more particularly to an automatic paper suction apparatus for feeding a sheet material such as paper used in an image forming apparatus such as a printer.

[0002]

2. Description of the Related Art Conventionally, this type of automatic paper suction apparatus has an idle gear train including a planetary gear directly receiving power from a platen gear and a toothless gear as disclosed in Japanese Patent Application Laid-Open No. 62-15437. With this configuration, only a certain amount of the regular rotation of the platen is transmitted to the pick roller connected to the tip of the gear, and the paper is sucked, with the reverse rotation of the platen as a trigger.

Referring to FIG. 9, which is a perspective view showing the configuration of this conventional automatic paper suction apparatus, this conventional automatic paper suction apparatus has a first idle gear which engages with a gear 48 fixed to a platen shaft. 41 and the first idle gear 4
A second idle gear 42, which is a planetary gear connected by a link about the main shaft 1, a third idle gear 43 engaged with the first idle gear 41, and fixed coaxially with the third idle gear 43. A fourth idle gear 44, a fifth idle gear 45 engaged with the fourth idle gear 44, and a pick roller 51 engaged with the fifth idle gear 45 and feeding the sheet are provided coaxially. And the fourth idle gear 44 and the fifth idle gear 45 are disengaged from a part of the tooth surfaces of the third idle gear 43 and the fourth idle gear 44. Notched portions are provided so that the third idle gear 43 and the first idle gear 41 are later disengaged from each other.

[0004] With such a configuration, the gears are respectively engaged by giving a forward rotation in the direction of arrow a by the ejection command and then giving a reverse rotation in the direction of arrow b by the suction command, and then in the direction of arrow a. The paper is sent from the pick roller 51 to the rear of the platen 52 by returning to the normal rotation, and the paper is discharged from the suction device by further rotating the paper forward.

[0005]

A first problem with this conventional automatic paper suction device is that line feed accuracy is disturbed and the load on the paper feed motor is increased.
The reason is that since the paper is constantly pressed by the pick roller, the frictional load of the pick roller is applied to the paper even during printing.

A second problem is that the skew of the paper discharged from the paper suction device is not corrected. The reason is that there is no step of rotating the discharge roller in the reverse direction, and there is no step of abutting the leading end of the sheet against the stopped or reversed member.

An object of the present invention is to automatically press a sheet to a pick roller only when necessary, and to correct skew of a discharged sheet in order to prevent line feed accuracy disturbance and increase in load on a sheet feed motor. An object of the present invention is to provide a paper suction device.

[0008]

According to the present invention, there is provided an automatic sheet suction apparatus comprising: a sheet stacking member for stacking cut sheets; conveying means for conveying the uppermost stacked sheet; Pressing means for pressing or releasing the sheet via the sheet stacking member, and rotation for performing both operations of rotating the conveying means and pressurizing / releasing the pressing means by power from a sheet feeding motor which is a rotational power generation source. Intermittent means, wherein the pressing means includes a spring member that presses the paper stacking member, and a cam member that rotates through the rotation intermittent means that slides or rotates the paper stacking member against the spring member. A first cutout portion for connecting and disconnecting power using a planetary gear by rotation of the paper feed motor in a paper discharge direction;
A second gear portion for transmitting rotation continuously in a direction opposite to the sheet discharging direction via the planetary gear and the idle gear; and a third gear portion for transmitting power to the cam member. A gear unit and a fourth gear unit having a notch for controlling the rotation of the conveying unit are provided on the same axis.

[0009]

[0010]

[0011] The automatic sheet inhaler of the present invention, the continuous rotation of the sheet discharge direction of the paper feed motor, to cut the power to the conveying means and the pressing means, said paper to said conveyor means Release state, and then, by rotating the paper feed motor in a direction opposite to the paper discharge direction, the power to the transporting means and the pressing means is connected, and then the paper is rotated by the rotation interrupting means. The pressing means is pressed to the conveying means by the pressing means, the conveying means is rotated in the paper discharging direction, a paper suction operation is performed, and then the paper is transferred to the paper conveying roller rotating in the direction opposite to the paper discharging direction. After hitting, the power to the conveying means is cut off by the rotation interrupting means, and then the pressurized state of the transport means of the sheet is released by the rotation interrupting means,
Next, the paper feed motor is rotated in the sheet discharge direction, the paper by rotating the conveying means so Kuitsuka to the paper transport roller, and conveyed to indexing position of the paper,
The power of the paper feed motor is controlled by the rotation interrupting means.
One cycle of the sheet suction operation is completed by cutting off the rotation of the transport unit and the pressing of the pressing unit.

[0012]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention, and is a state diagram before a sheet is sucked. FIG. 2 is a diagram showing a state in which the pick roller according to the embodiment picks up the paper, FIG. 3 is a diagram showing a state in which the skew correction is performed by abutting the leading end of the paper against the paper transport roller after the pick-up in this embodiment, FIG. 5 is a diagram showing a state in which the paper is being conveyed after the paper skew correction in this embodiment, and FIG. 5 is a diagram showing a state in printing the paper in this embodiment. FIG. 6 is a detailed view showing the structure of the mechanism section in this embodiment, and FIG. 7A is a perspective view of a timing gear for taking the timing of the sheet suction operation in this embodiment. FIG. 4B is a diagram illustrating a meshing state between the timing gear and the pick roller gear. FIG. 8 is a time chart showing an example of the operation in this embodiment.

Referring to FIGS. 1 and 6, an automatic paper inhaler 6 according to this embodiment includes a paper loading member 5 for loading cut-sheet paper 4 and a pick for transporting the uppermost loaded paper 4. A roller 3, a pressure spring 7 and a cam 27 for pressing or releasing the paper 4 on the pick roller 3 via the paper loading member 5, and both a rotation of the pick roller 3 and a pressure / release to the pressure spring 7. And a timing gear 21 for performing an operation.

Further, as shown in FIGS. 6 and 7, the timing gear 21
00 to rotate the roller gear 30 and the sun gear 22
And a gear portion 21a having a notch for connection / disconnection using the planetary gear 23, and a direction 1 opposite to the sheet feeding.
A gear 21b for transmitting the rotation of the cam 27 for sliding or rotating the paper stacking member 5 via a cam gear 26; And a gear portion 21d having a notch for controlling the rotation of the pick roller 3 via a pick roller gear 28. The gear portion 21d is provided with the pick roller 3 just before the conveyance of the sheet
And a cutout 312 for cutting off the power to the pick roller 3 after skew correction by abutting the sheet 4 on the sheet conveying roller 1.

Next, the paper suction operation will be described with reference to the state diagrams of FIGS. 1 to 5, the detailed mechanism diagrams of FIGS. 6 and 7, and the time chart of FIG.

Referring to FIGS. 1 and 6, when the paper feed motor 29 continuously rotates the paper feed roller 1 in the paper feed direction 100 by a predetermined amount or more before the paper 4 is sucked, the planetary gear 23 moves to the position 23a. The power is cut off at the notch of the gear portion 21a of the timing gear 21. This position becomes the home position. At this time, as shown in FIG. 7, the pick roller 3 is idle due to the notch 311 of the gear 21 d of the timing gear 21 via the pick roller gear 28. This state time is the start time point 301 in FIG. That is, the pick roller 3 and the sheet 4 are stopped. Further, since the sheet stacking member 5 is pressed down by the cam 27 against the pressure spring 7, the sheet 4 is released without being pressed by the pick roller 3. Further, the paper transport roller 1 and the paper feed motor 29 are both stopped.

Next, referring to FIGS. 2 and 6, the paper feed motor 29 rotates the paper transport roller 1 in the direction 101 opposite to the paper feed direction, and the planetary gear 23 revolves to the position 23b, via the idle gear 25. As a result, the power is transmitted in the same manner as in the case where the rotation direction is 23a, so that the cam 27 performs the release → pressurizing operation of the sheet stacking member 5. This operation is the state 302 in FIG. That is, the pick roller 3 and the sheet 4 are stopped following the state 301. Further, both the sheet conveying roller 1 and the sheet feed motor 29 start to reversely rotate from the stop state to the reverse line feed state. Further, the paper loading member 5 starts pressing the paper 4 against the pick roller 3 by the force of the cam 27 and the pressure spring 7. At this time, as shown in FIG. 7, the pick roller 3 is provided with the notch 3 of the gear portion 21d of the timing gear 21.
11 still idle.

Next, referring to FIGS. 3 and 6, when the paper transport roller 1 is continuously rotated by the paper transport motor 29 in the direction 101 opposite to the paper transport direction, the pick roller 3 starts rotating in the paper transport direction, and the paper 4 is rotated. Is picked up by the pick roller 3. The picked up paper 4 is placed in a direction 10 opposite to the paper feed direction.
The skewed sheet 4 is formed by abutting the leading end of the sheet conveying roller 1 rotating on the sheet feeding roller 1 and slackening the sheet by a predetermined amount.
Is corrected. During this operation, the paper loading member 5 is
7, the pressurized state is still maintained. This operation is shown in FIG.
State 303. That is, the pick roller 3 and the paper 4 rotate or move in the forward / return direction after the pickup, and the paper stacking member 5, the paper transport roller 1 and the paper feed motor 29 are all in the final state 302.

Next, the paper feed roller 29 is rotated by the paper feed motor 29 in the direction 101 opposite to the paper feed direction to press and release the paper loading member 5. At this time,
The pick roller 3 is stopped by a notch 312 different from the notch 311 of the gear portion 21d of the timing gear 21 which engages with the pick roller gear 28. This is the state 304 in FIG. That is, the pick roller 3 and the sheet 4 are stopped, and the sheet stacking member 5 and the sheet transport roller 1 are stopped.
And the paper feed motor 29 maintains the state 303.

Here, as shown in FIG. 4, when the paper feed roller 1 is rotated in the paper feed direction 100 by the paper feed motor 29, the timing gear 2 shown in FIGS.
Power is transmitted to the pick roller 3 beyond the notch 312 of the first gear 21d. The pick roller 3 is rotated in the paper feed direction 100 by the planetary gear 23 revolved to the position 23a while the paper transport roller 1 is rotating in the paper feed direction 100, and the paper 4 is transported from the upstream direction to the paper transport roller 1 direction. As a result, the paper 4 is bitten by the pressure roller 2, and the paper 4 is fed to the specified cueing position. When the sheet feeding to the cueing position is completed, the timing gear 21 comes to the home position at the notch of the gear portion 21a. This state is indicated by 305 in FIG. Thereafter, as shown in FIG. 5, printing is executed by the print head mounted on the carriage 11 in accordance with the print command, as shown in FIG.
6 and later.

As described above, by using the timing gear 21 and the cam 27 opposed to the pressure spring 7, a positive rotation in the direction of the arrow 100 is given by a discharge command, and then a suction command is given by a suction command. By applying the reverse rotation in the direction of arrow 101 only to the paper transport roller 1, the skew of the paper 4 transported by the pick roller 3 is corrected,
The paper 4 can be discharged.

[0023]

As described above, the first effect of the present invention is that there is no disturbance in line feed accuracy and no increase in load on the paper feed motor. The reason is that the frictional load of the pick roller is not applied to the sheet during printing, and the pick roller is pressed against the sheet only when necessary.

The second effect is that the skew of the sheet discharged from the sheet suction device is corrected. This is because the leading edge of the sheet can be abutted by the reverse rotation step of the sheet conveying roller.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an embodiment of the present invention, and is a state diagram before a sheet is sucked.

FIG. 2 is a state diagram at the time of paper pickup by a pick roller in the embodiment.

FIG. 3 is a diagram illustrating a state in which skew correction is performed by abutting the leading end of a sheet against a sheet conveyance roller after sheet pickup in this embodiment.

FIG. 4 is a diagram illustrating a state in which a sheet after sheet skew correction is being conveyed in this embodiment.

FIG. 5 is a state diagram at the time of paper printing in this embodiment.

FIG. 6 is a detailed view showing a configuration of a mechanism section in the embodiment.

FIG. 7A is a perspective view of a timing gear for setting a timing of a sheet suction operation in this embodiment, and FIG. 7B is a diagram showing an engagement state between the timing gear and a pick roller gear. is there.

FIG. 8 is a time chart showing an example of the operation in the present embodiment.

FIG. 9 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper conveyance roller 2 Pressure roller 3 Pick roller 4 Paper 5 Paper loading member 6 Automatic paper suction device 7 Pressure spring 11 Carriage 21 Timing gear 22 Sun gear 23 Planet gear 25 Idle gear 26 Cam gear 27 Cam 28 Pick roller gear 29 Paper feed motor

Claims (2)

(57) [Claims] 1. A sheet stacking member for stacking cut sheets, a conveying unit for conveying the uppermost stacked sheet,
A pressing means for pressing or releasing the paper on the transport means via the paper stacking member; and a rotation of the transport means and a pressurization / release of the pressing means by power from a paper feed motor which is a rotational power generation source. Rotation intermittent means for performing both operations, wherein the pressing means includes a spring member for pressing the paper stacking member, and the rotation intermittent means for sliding or rotating the paper stack member against the spring member. A first gear having a notch for connecting / disconnecting power by using a planetary gear by rotation of the paper feed motor in a paper discharge direction; And how to discharge paper
A second gear portion for transmitting rotation in the opposite direction continuously through the planetary gear and the idle gear;
An automatic paper suction device comprising: a third gear portion for transmitting power to the cam member; and a fourth gear portion having a cutout portion for controlling rotation of the conveying means, on the same axis. . By wherein continuous rotation of the sheet discharge direction of the paper feed motor, to cut the power to the conveying means and the pressing means, the sheet is in the released state relative to the conveying means, then, the paper feed The rotation of the motor in the direction opposite to the paper discharging direction connects the power to the transporting means and the pressing means, and then presses the paper to the transporting means by the rotation interrupting means by the pressing means. State, the conveying means is rotated in the paper discharging direction to perform a paper suction operation. Next, the paper is abutted against a paper conveying roller rotating in a direction opposite to the paper discharging direction, and then the paper is transferred to the conveying means. the power was cut off by the rotating interrupter, then releasing the pressurized state of the conveying means of the sheet by the rotation interrupting means, then, times the paper feed motor to the sheet discharge direction Is allowed, the paper by rotating the conveying means so Kuitsuka to the paper transport roller, and conveyed to indexing position of the paper,
The power of the paper feed motor is controlled by the rotation interrupting means.
2. The automatic paper suction apparatus according to claim 1, wherein the rotation of the transport means and the pressing of the pressing means are cut to complete one cycle of the paper suction operation.