JPH0825651B2 - Seat feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding mechanism of a printer, and more particularly to a sheet feeder having a sheet feeding section of two systems.

[Prior Art] In a conventional sheet feeder of this type, as shown in FIG. 4, the platen 69 is rotated by an idler gear 45 through a platen gear 41, an idler gear 42 and a feed gear 43.
Conveyed to. The cam 57 is swung by the solenoid 60 and the tension coil spring 58 to engage the idler gear 46 of the first sheet supply section 61 or the idler gear 53 and the idler gear 45 of the second sheet supply section 62. Idler gear
The rotations of 46 and 53 are transmitted to the pick roller gears 47 and 52 and the one-way clutches 48 and 71 in this order, and only the reverse rotation of the platen 69 is transmitted to the respective pick rollers 65 and 66 through the one-way clutches 48 and 71. Pull out the paper. Here, the one-way clutches 48, 71 prevent the pick rollers 65, 66 from rotating in reverse to apply a reverse load to the paper when the paper is kicked out and the paper starts to be fed by the forward rotation of the platen 69. It is preventing.

[Problems to be Solved] The above-described conventional sheet feeder has a drawback that it is not cheap because it has an expensive part called a one-way clutch for each system. Also, since the position of the cam is set by the solenoid and coil spring, there is a drawback that the solenoid will overheat when the system on the side selected by the suction of the solenoid is used continuously, and it is necessary to use a large capacity. It was

[Means for Solving Problems] In order to solve the conventional problems, the present invention provides a sheet feeder that further feeds, by the forward rotation of the platen, the paper that is ejected from the paper supply unit by the reverse rotation of the platen. The paper supply unit includes a first paper supply unit and a second paper supply unit, and the first paper supply unit includes a first paper ejection mechanism,
The second sheet supply unit includes a second sheet ejection mechanism, and a gear transmission system that transmits the normal rotation and the reverse rotation of the platen to the sheet ejection mechanism. And a selection mechanism including a solenoid or the like that selectively connects either one of the paper ejection mechanisms to the gear transmission system, and the first paper ejection mechanism is coupled to the gear transmission system. When the second paper ejection mechanism is connected to the gear transmission system, the second paper ejection mechanism can transmit either the normal or reverse rotation of the platen. And does not include a one-way clutch such as the first paper ejection mechanism, and the selection mechanism is such that when the second paper ejection mechanism is connected to the gear transmission system, the platen rotates forward. A second sheet kick out mechanism, characterized in that it is controlled so that uncoupling from the gear train before starting.

[Examples] Next, a sheet feeder of the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a perspective view of an embodiment of the sheet feeder of the present invention. 2 and 3 are explanatory diagrams of the same operation.

The rotation of the platen gear 1 is transmitted to the idler gear 5 via the idler gear 2 and the feed gear 3. A feed roller 27 is connected to the feed gear 3 via a one-way clutch 4 and serves to discharge the printed paper. The one-way clutch 4 is used to prevent the reverse rotation of the platen 29 during sheet suction from being transmitted to the feed roller 27. A solenoid 20 and a tension coil spring 18 are connected to an arm 19 engaged with the cam 17, and the cam 17 takes two positions depending on whether the solenoid 20 is on or off. The idler gears 6 and 13 are rotatably supported by gear arms 10 and 15, respectively, and are biased toward the idler gear 4 by torsion springs 9 and 14. Collars 11 and 16 are locked to one ends of the gear arms 10 and 15 and come into contact with the cam 17.
As shown, only one of the idler gears 6 and 13 can engage with the idler gear 5 at two positions of the cam 17. That is, when the solenoid 20 is off, the idler gear 6 is engaged with the idler gear 5 as shown in FIG. 2, and when the solenoid 20 is on, the idler gear 13 is engaged with the idler gear 5 as shown in FIG. The idler gear 6 is engaged with the pick roller gear 7. The pick roller 25 is installed on the pick roller shaft 23 so as to rotate in the same manner as the pick roller shaft 23. The pick roller shaft 23 and the pick roller gear 7 are connected via a one-way clutch, and the one-way clutch 8 is used in a direction for transmitting only the reverse rotation of the platen 29. The idler gear 13 is engaged with the pick roller gear 12. The pick roller 26 is installed on the pick roller shaft 24 so as to rotate in the same manner as the pick roller shaft 24. Pick roller shaft
24 is integrated with the pick roller gear 12.

The operation of this embodiment is performed as follows. First, when sucking a sheet from the first sheet cassette 21, the platen 29 may be rotated in the reverse direction by a certain amount while the solenoid 20 is off. This allows the pick roller to go through the gear system.
25 is rotated, and as is known in the art, a sheet is taken out from the paper feeding cassette unit 21 (for example, in cooperation with a claw portion), and its tip is placed between the platen 29 and the pressure roller 30. Be engrossed. At this point, the platen 29 is rotated in the forward direction and the paper is taken into the printer. After that, the paper is discharged by the feed roller 27 and the pressure roller 28. Here, due to the action of the one-way clutch 8, the pressure roller 25 is free in the direction in which the paper is fed, and does not interfere with the feeding of the paper.

When sucking a sheet from the second sheet cassette 22, the following procedure is performed.

First, the solenoid 20 is turned on and brought into the state shown in FIG. 3, and the platen 29 is rotated in the reverse direction. As a result, the pick roller 26 is rotated via the gear system, one sheet of paper is taken out from the paper feeding cassette portion 22, and the tip end portion is stuck between the platen 29 and the pressure roller 30. If the solenoid 20 is turned off here, the state shown in FIG. 2 is restored. Next, the platen 29 is rotated in the forward direction. At this time, since the idler gear 16 and the idler gear 5 are disengaged from each other, the pick roller 26 is free. The one-way clutch 8 also makes the pick roller 25 free in the direction in which the paper is fed.

[Effects of the Invention] As is apparent from the above, the present invention uses the one-way clutch only for one of the two paper supply systems, and connects the other paper supply system only when the platen is rotated in the reverse direction. The result is that the number of sheets used can be reduced and an inexpensive sheet feeder can be constructed. Further, the present invention has an effect that the energization time of the solenoid can be reduced and a small solenoid can be used.

[Brief description of drawings]

1 is a perspective view of an embodiment of the present invention, FIG. 2 and FIG.
FIG. 4 is an explanatory view of the same operation, and FIG. 4 is a perspective view of a conventional example. 1: Platen gear 2, 5, 6, 13: Idler gear 3: Feed gear 4, 8: One-way clutch 7, 12: Pick roller gear 17: Cam 20: Solenoid 21, 22: Paper feed cassette section 25, 26: Pick roller 27 : Feed roller 28, 30: Pressure roller 29: Platen

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-54-138714 (JP, A) JP-A-48-104545 (JP, A) JP-A-58-90972 (JP, A)

Claims (1)

[Claims] 1. A sheet feeder having the following requirements. (A) A sheet feeder that further feeds the paper ejected from the paper supply unit by the reverse rotation of the platen by the normal rotation of the platen. (B) The paper supply unit is composed of a first paper supply unit and a second paper supply unit. (C) The first sheet supply section has a first sheet ejection mechanism, and the second sheet supply section has a second sheet ejection mechanism. (D) A gear transmission system for transmitting the normal rotation and the reverse rotation of the platen to the sheet ejection mechanism is provided. (E) A selection mechanism including a solenoid or the like for selectively connecting either one of the first and second sheet ejection mechanisms to the gear transmission system. (C) The first sheet ejection mechanism includes a one-way clutch that transmits only the reverse rotation of the platen when coupled to the gear transmission system, and the second sheet ejection mechanism includes the one-way clutch. When connected to a gear transmission system, it can transmit both the forward and reverse rotations of the platen, and does not include a one-way clutch such as the first paper ejection mechanism. (G) When the second paper ejection mechanism is connected to the gear transmission system, the selection mechanism disconnects the second paper ejection mechanism from the gear transmission system before the platen starts to rotate normally. Be controlled.