JPH03232630A - Parer feed mechanism - Google Patents

Abstract

PURPOSE:To eliminate the necessity of a change-over magnetic clutch for the rotation of a pick-up roller and a standby roller and to provide a cheap sheet feed mechanism by providing a drive transmission mechanism for transmitting a drive power so as to rotate the pick-up roller during normal rotation of a drive source while rotating the standby roller during reverse rotation thereof. CONSTITUTION:When a motor 98 is rotated counterclockwise, a gear G7 is rotated clockwise, and accordingly, a friction lever 75 is rotated similarly clock wise about a shaft. Further, a planetary gear G8 is meshed with a gear G9 so that a torque is transmitted through a train of gears G9, G10, G11, G12 to the pick roller 34a which is therefore rotated counterclockwise. The rotation of the pick roller 34a causes a sheet 10 on a hopper 33a to be transferred to a standby roller. After the sheet 10 is held between the standby roller and a pinch roller 12a, the motor 98 is reversed to stop the rotation of the pick roller 34 while rotating the standby roller.

Description

[Detailed Description of the Invention] [Summary] Regarding the paper feeding mechanism of a printer device, the purpose of providing an inexpensive paper feeding mechanism is to provide a hopper in which a plurality of sheets of paper are stacked, and a pick for feeding out the paper from the hopper. a roller, a standby roller that holds the fed paper in a standby state by sandwiching it; a drive source that can rotate in forward and reverse directions; and a drive source that rotates the pink roller when the drive source rotates in the normal direction, and the standby roller that rotates when the drive source rotates in the reverse direction. and a power transmission mechanism that transmits power so as to rotate the motor.

[Industrial application field]

The present invention particularly relates to a paper feeding mechanism of a printer device.

[Conventional technology]

In recent years, automatic paper absorption has become popular in printers and there is a high demand for printing position accuracy on paper, so paper skew correction means for automatic paper absorption has been provided.

This correction means performs automatic paper absorption while rotating/stopping the paper feed roller (standby roller) that engages after automatic paper absorption, hits the paper against the standby roller, corrects the paper skew, and then waits A method is used to feed the paper by rotating rollers.

In the conventional paper feed mechanism, an intermediate gear with a magnetic clutch is provided between the paper feed drive gear and the gear on the paper feed roller shaft, and the intermediate gear is engaged/idled by turning on/off the excitation of the magnetic clutch. The rotation/stop of the standby roller was controlled by

[Problem to be solved by the invention]

However, using a magnetic clutch to rotate/stop the standby roller requires electrical continuity and the magnetic clutch itself is expensive, so there is a problem in that it increases the cost of the entire printer device.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, an object of the present invention is to provide a paper feeding mechanism with an inexpensive structure.

[Means to solve the problem]

The purpose of this is to provide a hopper in which a plurality of sheets of paper are stacked, a bin roller for feeding out the paper from the hopper, a standby roller for holding the fed out paper in a standby state, and rotating in forward and reverse directions. This is achieved by a paper feeding mechanism that is equipped with a power transmission mechanism that transmits power so as to rotate the big roller when the drive source rotates in the normal direction and drive the standby roller to rotate when the drive source rotates in the reverse direction. be done.

[For production]

That is, according to the present invention, by switching between forward and reverse rotation of the drive source, it is possible to switch between rotating and stopping the big roller and the standby roller, thereby providing an inexpensive paper feeding mechanism.

〔Example〕

Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings.

FIG. 2 is an explanatory diagram of the configuration of an electrophotographic printer to which the present invention is applied.

In the figure, the upper frame unit 31 includes a fuser unit 7) 36. Cooling fan 40. Entry sensor 41. Emission sensor 42. The transfer device 43 etc. are installed, and the first
A hopper 33a and a second hopper 33b are detachably attached. Pin rollers 34a and 34b are attached to the first hopper 33a and the second hopper 33b, respectively, and feed rollers 35a and 3 provided on the upper frame unit 31
5b corresponds to this. Different types of cut sheets 10 are stored in these hoppers, and one of the hoppers is selected by the action of a magnetic clutch during printing. The fixing unit 36 includes a heat roller 37°, a backup roller 38. A discharge roller 39 is integrated.

The lower unit 32 includes a toner storage section 70. Developing roller 7
2, a front charger 74, a cleaning blade, a cleaner 80 including a waste toner storage section, and a photosensitive drum 55.
0 is installed.

Further, an LED array 53 for exposing the photosensitive drum 55, a motor capable of reversible rotation, and the like are provided.

FIG. 1, FIG. 3, FIG. 4, and FIG. 5 are configuration explanatory diagrams of the power transmission system.

The photosensitive drum 55 has a gear G attached to its drive shaft.
, G3. One-way clutch 20c, gears G3', G2'
, G2. Rotation from the motor 19 is transmitted via Gl. Incidentally, a sleeve and an agitator (not shown) in the developing device 52 are branched from this gear train, particularly the gears G and G3, and are rotationally driven.

This one-way clutch 20c transmits rotation only when the motor 19 rotates counterclockwise as shown in FIG.
It is configured so that rotation is not transmitted during reverse rotation.

The heat roller 14 constituting the fixing device fixes the toner powder image by sandwiching the paper 10 between the heat roller 14 and a backup roller 14a disposed opposite to the heat roller 14, and a one-way clutch 20d.

Gear G14. G15. G16. G17. It is connected to gear G6'' via GlB.

Gear G6° is coaxially mounted gear G6. Gear G5.
G50. G4. It is connected to motor gear 19b via Gl.

The discharge roller 16 is for discharging the paper 10 after fixing to the outside of the system, and the one-way clutch 20e.

Gear G19. G20. It is connected to gear G16 via G21.

The entry sensor 41 is installed to detect that the paper 10 has arrived at the standby position immediately in front of the standby roller 35a, and the ejection sensor 42 is installed to detect that the paper 10 has been ejected from the system by the ejection roller 16. There is.

The one-way clutches 20d and 20g are configured to transmit rotation only when the motor 19 rotates clockwise, and not to transmit rotation when the motor 19 rotates in the opposite direction.

The pick roller 34a has a gear G12 attached to its drive shaft, and a gear train G11. G
IO and G9 are connected.

Gear G9 is a planetary gear 8. Motor gear G via gear G7
By being connected to the motor 60, the rotational force from the motor 98 is transmitted.

The standby roller 35a is arranged opposite to the pinch roller 12.
The paper 1 fed out from the pick roller 11 between the
The paper 10 is held in a standby state by holding the paper 10 between them, and is then rotated to feed the paper 10 into the image forming area. A gear 20b is attached to the shaft of this standby roller 35a, as shown in FIG. The gear 20b is an idle gear G55. By being connected to gear G50 via gear G65, gear train G50. G4. It is connected to motor gear 19b via Gl, and rotation from motor 19 is transmitted thereto.

The planet gear 8 and the idle gear G55 are rotatably supported by an L-shaped friction lever 75, as shown in FIG. This friction lever 75 is gear G7
It has an arm portion 75a that engages in a groove provided along the circumferential direction of the shaft 97. Therefore, the friction lever 75 swings in accordance with the forward and reverse rotation of the gear G7 due to the frictional force between the arm portion 75a and the shaft 97, and at the same time, the planetary gear 8. Idle gear G55 also swings.

As a result, when the motor 98 rotates counterclockwise, the gear G7 rotates clockwise, so the friction lever 7
5 similarly rotates clockwise around the shaft 97. and,
Since planetary gear G8 meshes with gear G9, gear train G9.
The rotational force is transmitted to the pick roller 34a via GIO, Gll, and G12, and the pick roller 34a can be rotated counterclockwise.

The rotation of the pick roller 34a transports the paper 10 on the hopper 33a toward the standby roller 35a. and,
Paper 10 is held between standby roller 35a and pinch roller 12a.

When the motor 98 is rotated clockwise in this state, the friction lever 75 is rotated counterclockwise around the shaft 97, so that the engagement between the planetary gear G8 and the gear G9 is released, and the rotation of the pick roller 34a is stopped. . Further, the idle gear G55 meshes with the gear G65 and the gear 20b,
In response to the power from the motor 19, the rotational force of the gear 065 is transmitted to the gear 20b, which is already rotationally driven, so that the standby roller 35a rotates.

Therefore, the paper 10 is conveyed toward the photosensitive drum 55.

As explained above, according to this embodiment, the pick roller 34a and the standby roller 35a are rotated by the forward and reverse rotation of the motor 98.
In the drawings in which the rotation of the rotor can be switched, the same parts as in FIGS. 1 to 4 are given the same numbers, and their explanations will be omitted.

The difference from FIG. 1 is that the motor 98 and motor gear G60 are omitted, and the rotational force from gear G65 is directly applied to gear G7.
The point is that it is configured to transmit information.

By adopting this configuration, the direction of power transmission can be switched between the paper feeding system having the pick roller 34a and the process system including the standby roller 35a and the photosensitive drum only by the forward and reverse rotation of the motor 19.

The operation will be explained with reference to the operation time chart shown in FIG.

First, when receiving a pick command for the paper 10 and rotating the motor 19 in one direction (clockwise), the one-way clutch 20c
Due to the action of , the photosensitive drum 55 is in a stopped state, and the gear G65 rotates counterclockwise and the gear G7 rotates clockwise via the gear G85, so that the planetary gear G8 rotates to the gear G9 as described above. meshing, pick roller 34a
rotates and the paper 10 is fed out.

It is fed out by the drive of the pink roller 11 and sent to the feed roller 34.
When the vehicle reaches point a, the entry sensor 41 detects this. Thereafter, after T1 has elapsed, the motor 19 is rotated in the slave direction (counterclockwise direction) by a command from a control section (not shown).

As a result, the process system including the photosensitive drum 55 starts rotating. At the same time, a control device (not shown) starts image exposure by the LED array 53 based on the debio data from the host.

Also, due to the counterclockwise rotation of the motor 19, the gear G6
5 rotates counterclockwise, and the gear G7 is rotated through the gear G65.
rotates clockwise, as described above, the engagement between the planetary gear G8 and the gear G9 is released, power is not transmitted to the pin roller 34a, and on the other hand, the idle gear G5
5 meshes with gear G65 and gear 20b, so gear 2
0b is gear G65. Rotationally driven via the idle gear G55, the standby roller 35a sends out the paper 10.

In this manner, the paper IO is introduced into the image forming area, and then is discharged onto the stacker 63 by the discharge roller 16.

When the ejection of the paper lO is detected by the ejection sensor 42, the motor 19 is stopped by a command from the control section after T2 has elapsed, and waits for the next printing command.

T1. T2 is the time for reliable operation.

In this manner, in this embodiment, the rotational drive of the paper feeding system and the process system can be switched only by rotating the motor 19 in the forward and reverse directions.

〔Effect of the invention〕

As described above, according to the present invention, an inexpensive configuration can be realized without using a magnetic clutch for switching the rotational drive of the pick roller and the standby roller.

[Brief explanation of drawings]

1, 3, 4, and 5 are explanatory diagrams of the structure of the power transmission system, and FIG. 2 is an electrophotographic printer to which the present invention is applied. ? -Ah. In the figure, 10 is paper, 19 is a motor, 33 is a hopper, 34a is a pick roller, 35a is a standby roller, G8 is a planetary gear, and G55 is an idle gear.

Claims (1)

[Scope of Claims] A hopper in which a plurality of sheets of paper are stacked, a pick roller for feeding out the paper from the hopper, a standby roller that holds the fed out paper in a waiting state by sandwiching it, and forward and reverse rotation. A paper feeding mechanism comprising: a rotatable drive source; and a power transmission mechanism that transmits power so as to rotationally drive the pick roller when the drive source rotates in the normal direction and to rotationally drive the standby roller when the drive source rotates in the reverse direction. .