JP2000344368A - Sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the rotating direction of a first conveying roller without using a solenoid by controlling the rotation in the loosening direction of a first spring clutch, and rotating the first conveying roller in the reverse direction. SOLUTION: An auxiliary conveying roller 33, a separation roller 16a, and a first conveying roller (conveying roller) are rotated through gears. When the driving force is transmitted to a transmission shaft 52 from the gears, a second spring clutch 29 is tightened, and the driving in the conveying direction (direction of arrow (f)) is transmitted to the separation roller 16a (a). The driving is transmitted from a gear 28 to a clutch shaft 34 through a first idler gear 37, but the driving is not transmitted through the first spring clutch 36 as the first spring clutch 36 is directed in the loosening direction. When the driving direction is reversed, the second spring clutch 29 is loosened, the transmission to the separation roller 16a is cut off, and the first spring clutch 36 is tightened, whereby the driving in the reverse direction (direction of arrow (g)) is transmitted to the auxiliary conveying roller 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for sequentially sending a plurality of originals, and an image forming apparatus having the same.

[0002]

2. Description of the Related Art A conventional image reading apparatus such as a copying machine or a facsimile will be described with reference to the drawings. FIG. 15 is an external view showing the overall configuration, FIG. 16 is a side sectional view of the image reading unit, and FIG.
FIG. 18 is a diagram for explaining the operation of the stopper, and FIG. 18 is a top view of the feeding device of the image reading unit.

[0005] An image reading apparatus 100 shown in FIG. 15 has an image reading section 101 at the top of the apparatus, and a feed tray 1 on both sides thereof.
02, and has a discharge tray 103. As shown in FIG. 16, a sheet guide following the feed tray 102 is provided inside the image reading unit 101.
104, a preliminary conveyance roller 105 for feeding the sheet, a weight 106 on the sheet, separation rollers 107 and 10 for separating and conveying the sheet
8. Convey rollers 109 and 110 for conveying the sheet to the reading unit 113
Is provided. The separation roller 107 and the conveyance roller 109 are rotatably attached to a lever 111, and are urged by a spring 112 toward the separation roller 108 and the conveyance roller 110, respectively.
The sheet whose image information has been read by the reading unit 113 is discharged to the discharge tray 103 by the discharge rollers 114 and 115.

In the sheet guide 104, if the user pushes the sheet bundle to the separation rollers 107 and 108 at a time when the preliminary conveyance roller 105 is stopped when reading the original, the sheets cannot be separated. So seat guide 10
In FIG. 4, a stopper 116 as shown in FIG. 16 is provided on the upstream side of the separation rollers 107 and 108 in order to stop and hold the document bundle stacked on the feeding tray 102, and the sheet bundle is separated from the separation rollers 107 and 108.
It is configured so that it cannot be pushed into 108.

As shown in FIG. 17, a stopper 116 is formed in an L-shape, and is configured to be rotatable so that a tip end 116a protrudes from a groove 104a provided in the sheet guide 104. A cam 117 abuts below the stopper 116, and the cam 116 is rotated to rotate the stopper 116.

The preliminary transport roller 105 has a semi-lunar shape having a cutout in a part thereof, and feeds the sheets on the sheet guide 104 one by one. The preliminary transport roller 105 is connected to a drive unit (preferably a pulse motor) (not shown) via a drive shaft 118, a gear train G1, and a spring clutch 119. A control ring 119a provided on the spring clutch 119
The locking claw member 120 engaging with the locking portion 119b of the
By operating by 1, the preliminary transport roller 105 controls one rotation. This configuration eliminates the need for a mechanism for moving the preliminary transport roller 105 up and down.
It stops reliably at the cutting position and does not get caught when placing the original.

When reading an original, the stop of the sheet is released by retracting the stopper 116, and the preliminary conveying roller 105
Is rotated to take out the sheets one by one from the sheet bundle and feed them to the separation rollers 107 and 108, and read the image information of the sheets by reading means 113 provided downstream while reliably separating the multi-fed sheets. The image is recorded on the recording sheet by an image forming means (not shown).

[0008]

However, in the above-mentioned conventional example, there are problems that the use of the solenoid increases the production cost and that it is necessary to secure a mounting space. In addition, since there are bundles coming out of the solenoid, assembly operation of the unit has been complicated. Further, the power consumption of the solenoid itself is large, and it is necessary to increase the capacity of the power supply, which has been a factor of increasing the cost of the power supply.

Further, since the pre-conveyance roller 105 performs one rotation control, if the roller and the sheet slide, the sheet does not reach the downstream separation rollers 107 and 108, resulting in a problem that the conveyance is poor. Was.

Accordingly, an object of the present invention is to provide a driving device and an image forming apparatus which control the rotation direction of a preliminary conveyance roller without using a solenoid, and which achieve cost reduction, downsizing, and improvement in assemblability. And

[0011]

In order to solve the above problems, a typical configuration of a driving device and an image forming apparatus according to the present invention includes a non-circular first conveying roller for conveying a sheet,
First drive transmission means for transmitting a rotational drive in the sheet transport direction to the first transport roller; second drive transmission means for transmitting a rotational drive in a direction opposite to the sheet transport direction to the first transport roller; A first spring clutch provided in the drive transmission means for interrupting the drive, and having one end of the first spring clutch projecting inward to be connected to the first transport roller and the first spring The other end of the clutch is projected outside at a predetermined phase with respect to the first transport roller,
Providing rotation restricting means for restricting rotation of the first spring clutch in a direction in which the first spring clutch is loosened in contact with the end protruding to the outside, and stopping the first transport roller at a predetermined phase by rotating in the reverse direction. It is characterized by.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a driving device and an image forming apparatus according to the present invention will be described with reference to the drawings. FIG.
FIG. 2 is a central cross-sectional view of the image forming apparatus, FIG. 3 is a view for explaining the overall configuration of the apparatus, FIG. 4 is a plan view of a cassette, FIG. 5 is a perspective view of image recording means, and FIG. FIG. 7 is a plan view of the lower document frame unit, FIG. 7 is a configuration diagram of the preliminary transport roller unit, FIG. 8 is a configuration diagram of the separation roller unit,
9 is a diagram illustrating the operation of the spring clutch, FIG. 10 is a plan view of the upper document frame unit, FIG. 12 is a diagram illustrating the operation of the sheet feeding device, and FIG.
FIG. 13 is a diagram illustrating the configuration of the stop spring, and FIG. 14 is a diagram illustrating the initialization operation of the stopper.

(Overall Description) In this embodiment, a description will be given using a facsimile apparatus having an ink jet recording means in an image forming apparatus. The facsimile apparatus shown in FIG. 1 includes a feeding system A for supplying a recording sheet, a recording system B as an image recording unit, a reading system C for reading an image described on a document, and an operation unit D. .

The recording sheet 2 may be a plain paper, a plastic sheet, or the like, or another material, to which ink can be transferred. In the present embodiment, plain paper cut into B4 size or A4 size is used as the recording sheet 2.

The operation unit D is for performing operations such as the mode switching operation, copy operation, transmission operation, printer operation, etc., and is provided with keys corresponding to various operations. The operation unit D is provided above the document transport mechanism in the reading system C, and is configured to be rotatable in the direction of arrow e shown in FIG. When a defect occurs, the jam is easily removed. One side of the operation unit D is equipped with a telephone handset (not shown) that performs transmission and reception.

(Feeding System) As shown in FIG. 2, a feeding system A separates a recording sheet 2 placed on a feeding cassette 1 from a feeding roller 3 and a claw 4 opposed thereto. Then, the recording sheet 2 is supplied to the recording system B by the feed roller pair 5. The feed roller 3 is a roller made of a material having a high coefficient of friction such as silicone rubber, and is rotated in a direction indicated by an arrow in FIG. 1 by a drive source (not shown) to convey a conveying force to the uppermost recording sheet 2 of the feed cassette 1. Is added.

As shown in FIG. 4, pawls 4 are provided at both ends of the feeding cassette 1 to prevent conveyance of the recording sheet 2 near the left and right ends, and the recording sheet 2 buckles and rises upward. When the sheet is further conveyed by the feed roller 3 in this state, the deformed portion pops out, and only the uppermost recording sheet can be reliably separated. Then record sheet 2
Is a recording system B which is a recording means by the feed roller pair 5.
Sent to.

In addition, near the recording system B, a leading end detecting sensor 6 such as a photo sensor for detecting the leading end position of the recording sheet 2 and a microswitch is provided. The feeding cassette 1 is provided detachably with respect to the apparatus main body 7, and is housed at a predetermined position of the apparatus main body 7 as shown in FIG. Further, the feed roller 3, the feed roller pair 5,
The tip detection sensor 6 and the like are provided on the main body.

(Recording system) The recording system B feeds an image signal transmitted from another device, an image signal transmitted from a reading system C described later, or data output from a computer or the like described later. The image is recorded on the recording sheet 2 supplied from the system A.

More specifically, the recording sheet 2 is conveyed by the platen roller 8 of the recording system B, and an image is formed by image recording means in accordance with the image signal or data. As the image recording means, a disposable type cartridge 9 in which an ink tank is integrated with a recording head of an ink jet recording system for discharging and recording ink is used, and ink droplets discharged from the recording head of the cartridge 9 are used as a recording sheet 2. An image is formed by adhering to the surface. That is, the recording head has a fine liquid discharge port (orifice), a liquid path, an energy action section provided in a part of the liquid path, and an energy generation section for generating droplet forming energy to act on the liquid in the action section. Means.

Means for generating such energy include a recording method using an electromechanical transducer such as a piezo element,
The liquid is heated by irradiating an electromagnetic wave such as a laser or the like to generate heat, and the liquid is heated by an electric converter such as a heating element having a heating resistor or a recording method using an energy generating means for discharging a droplet by the action of the heat. There is a recording method using an energy generating means for discharging ink. Among them, a recording head used in an ink jet recording method in which a liquid is discharged by thermal energy may have a high density of liquid discharge ports (orifices) for discharging a recording liquid droplet to form a discharge liquid droplet. Because it is possible, it is possible to record at high resolution. Furthermore, a recording head using an electrothermal transducer as an energy generating means can be easily made compact, and has sufficient advantages of IC technology and micro-machining technology, which have recently made remarkable progress in technology in the field of semiconductors and markedly improved reliability. This is advantageous because it can be easily used for high-density mounting, and the manufacturing cost is low.

As shown in FIG. 5, the cartridge 9 is mounted on the carriage 21, and the recording is performed by reciprocating scanning in the width direction of the recording sheet 2. An endless belt-like timing belt 23 wrapped around a pulley 22 driven by a motor 25 is connected to the carriage 21, and by driving the pulley 22 to rotate, the carriage 21 moves along a guide rail 24. It is reciprocated. At a position facing the cartridge 9, a platen 20 for supporting the recording sheet 2 is provided.

The transport amount of the recording sheet 2 is controlled by a platen roller 8. Here, if the recording sheet 2 sags in the vicinity of the cartridge 9 and rubs against the cartridge 9, the feed amount by the discharge roller 10a and the spur 10b is set to be several percent larger than the transport amount by the platen roller 8. In the present embodiment, the discharge roller 10a is designed to make one rotation when the platen roller 8 makes one rotation.
Therefore, the roller diameter of the discharge roller 10a is set to be several percent larger than that of the platen roller 8 so that the transport amount is increased. The conveying force of the platen roller 8 is larger than that of the discharge roller 10a and the spur 10b. Accordingly, in a state where the recording sheet 2 is held by the two types of roller pairs, the recording sheet 2 is conveyed while slightly sliding at the discharge roller 10a and the spur 10b.

The recording sheet 2 on which a predetermined image has been formed is further conveyed in the direction of arrow a by a discharge roller 10a and a spur 10b, and discharged and stacked outside the apparatus by a discharge roller pair 11.
The discharge roller 10a, the spur 10b, and the discharge roller pair 11 are provided on the apparatus main body 7, respectively. Also, as shown in FIG.
By releasing the recording cover 12 in the direction of arrow c, the cartridge 9 is configured to be detachable from the carriage 21 in the direction of arrow d.

(Reading System) The reading system C irradiates the original 13 with light, converts the reflected light into an electric signal, and transmits this signal to another apparatus through the operation mode, or transmits it to its own recording system B. Is what you do. In FIG. 1, a plurality of originals 13 are placed on an original tray 15 which is a sheet stacking means, and the originals 13 are separated and fed one by one by a separation roller 16a which is a second transport roller and a pressure contact piece 16b which is pressed against the original. And the manuscript 13
Is transported by transport rollers 17a, 17b and discharge rollers 18a, 18b, which are third transport rollers, and is discharged outside the apparatus. While the original 13 is being conveyed, an image signal is read by a reading unit including a photoelectric conversion element 19 such as a contact sensor, and the image signal is transmitted to its own recording system in a copy mode in the copy mode. In the case of the mode, the data is transmitted to the recording system of another device.

As shown in FIG. 6, in the lower original frame 26 of the apparatus main body 7, the original tray 15, the separation roller unit 27 including the separation roller 16a, the preliminary conveyance roller unit 32, the first idler gear 37, and the second idler gear 38. , Transport roller 17
a, a discharge roller 18a, and a photoelectric conversion element 19 are attached.

As shown in FIG. 7A, a separation roller unit
The mold part 31a is press-fitted into the separation roller shaft 31 of 27 and always rotates integrally with the separation roller shaft 31. A gear 28 is slidably fitted to one end of the separation roller shaft 31, and a separation roller 16a is slidably fitted to the opposite side of the gear 28 across the mold portion 31a. A gear 30 is fitted to the other end of the separation roller shaft 31, and the fitted portion is formed in a D-shape so as to rotate integrally with the separation roller shaft 31. Accordingly, in the combined state as shown in FIG. 7B, the second spring clutch 29 is applied to the gear 28, the mold portion 31a, and the separation roller 16a, and the driving force of the gear 28 is applied to the separation roller shaft.
It is configured such that it can be transmitted independently to the separation roller 31 and the separation roller 16a.

The second spring clutch 29 is engaged with the gear 28, the mold portion 31a, and the separation roller 16a. When the gear 28 is rotated in the direction indicated by the arrow f in FIG.
The winding direction is such that a is driven. Also gear 28
Is also rotated in the direction of arrow f, and the separation roller 16a is rotated at a higher speed.
Is loosened and the gear 30 is not driven. Further, when the gear 28 is rotated in the direction of arrow g, the separation roller 16a and the gear 30 are not driven because the second spring clutch 29 is loosened.

As shown in FIG. 8, the preliminary transport roller unit 32 has a preliminary transport roller 33 as a first transport roller inserted into a preliminary transport roller shaft 35 as a drive transmission side shaft, and one end at one end. And a gear 35c is provided at the other end. Preliminary transport roller shaft 35
The first spring clutch 36
Is inserted. As shown in FIG. 8 (b), the first spring clutch 36 bends and raises one end 36a to the inner peripheral side, and the other end 36a.
36b is bent and raised to the outer peripheral side. At a position corresponding to the end 36b, a pendulum 55, which is a rotation restricting means described later, is provided (see FIG. 14).

Here, a notch 35a is provided in the preliminary conveying roller shaft 35, and an end 36a on the inner peripheral side is inserted into the notch 35a. On the other hand, the end 36b on the outer peripheral side enters a groove 33a provided on the inner periphery of the preliminary transport roller 33, and is configured so that the phases in the rotating direction match. The winding direction of the first spring clutch 36 is
When the clutch shaft 34 is rotated in the direction of the arrow g shown in the figure, it is tightened and the preliminary transport roller shaft 35 also rotates, and when it is rotated in the direction of the arrow f, it is loosened and the drive is not transmitted to the preliminary transport roller 33. ing.

The pre-conveyance roller 33 has a cam shape as shown in FIG. 8 (c).
And a pre-transfer pressing plate 54 biased by the Therefore, when the preliminary transport roller 33 rotates, it is configured to transport according to its phase or to release the transport path. The pre-conveyance roller shaft 35 has a D-shape as shown in FIG. 8 (d), and is configured so that a stop spring 39 as a stopping means can be urged to stop at a predetermined phase as shown in FIG. Have been.

FIG. 9 is a view seen from the direction of the arrow j in FIG. 6, and shows a drive gear. The drive means (not shown) is a gear
49, drives the gear 50, and the gear 50 drives the gear 51. gear
49 is connected to a discharge roller 18a from a discharge roller shaft 57 (see FIG. 6) via a one-way clutch (not shown). No drive is transmitted when rotated in the (1 direction).

The shaft hole of the gear 50 is D-shaped, and drives the transport roller shaft 56 (see FIG. 6). Gear 50 is gear 51
The shaft hole of the gear 51 is also D-shaped, and drives the gear 53 via a transmission shaft 52 shown in FIG.

As shown in FIG. 10, the upper original frame 40 of the apparatus main body 7 has a press contact piece 16 which is paired with the separation roller 16a.
b, a separation spring 16c for pressing the pressure contact piece 16b against the separation roller 16a is attached. Also the upper manuscript frame 40
A DS actuator 41 for detecting that a document has been inserted and a DES actuator 42 for detecting the timing of starting reading are pivotally supported. The photo-interrupters interrupted by these actuators are mounted on the back surface of a substrate of an operation panel (not shown), and are configured to function when the operation panel is attached.

The upper original frame 40 includes a transport roller 17a.
Roller 17b, transport roller short 44, stopper roller
45 is supported by the transport roller shaft 43. Further, when the stopper roller 45 rotates, a stopper 46 rotatably attached is configured to come into contact with the stopper roller 45. Discharge roller 18
The discharge roller 18b facing a is supported by a discharge roller shaft 47. The transport roller shaft 43 and the discharge roller shaft 47 are shaft pressing springs.
48, and the shaft pressing spring 48 is
It is fixed so as to be sandwiched between the upper document stay 40a and the upper document stay 40a.

(Operation) Next, the operation of the reading-type sheet feeding apparatus will be described with reference to FIGS. FIG.
When a plurality of originals are inserted in the direction of arrow m in FIG.
After the actuator 41 is turned on, the leading edge of the document comes into contact with the stopper 46. Thereafter, when an instruction to start reading is issued on the operation panel, the drive is transmitted through the gears 49 to 51, and the preliminary transport roller 33, the separation roller 16a, and the transport roller 17a rotate in the direction of arrow f, and are attached to the transport roller 17a. The urged stopper roller 45 rotates in the direction of arrow g. As a result, the stopper 46 rotates to release the conveyance path while separating the stacked sheets.

As shown in FIG. 12A, the transmission shaft 52 is
Is transmitted, the second spring clutch 29 is tightened, and the drive in the transport direction (the direction of the arrow f) is transmitted to the separation roller 16a. At the same time, the drive is transmitted from the mold portion 31a to the separation roller shaft 31 by the second spring clutch 29, and the gear 30
The drive is transmitted to the gear 35c at the end of the preliminary transport roller shaft 35 via the second idler gear 38, and the preliminary transport roller 33 rotates in the transport direction (the direction of arrow f). That is, the first drive transmission means of the preliminary transport roller 33 includes the separation roller shaft 31, the second idler gear 38, and the gear 35c.

At this time, the drive is transmitted from the gear 28 to the clutch shaft 34 via the first idler gear 37, but the drive is not transmitted through the first spring clutch 36 because it is in the loosening direction. Further, since the first spring clutch 36 has the end portion 36a inserted into the notch 35a of the preliminary transport roller shaft 35, the first spring clutch 36 rotates together with the preliminary transport roller shaft 35. Therefore, as shown in FIG. At a position corresponding to the end 36b on the outer peripheral side of the clutch 36, a pendulum 55 serving as a rotation restricting means is arranged, and the end 36b contacts the pendulum 55. However, since the pendulum 55 has an inclined surface 55a at the tip and rotates and escapes as shown in FIG. 14 (b), the first spring clutch
36 can rotate.

Then, the conveyance of the sheet is started, and the sheet is separated one by one by the separation roller 16a and the pressure contact piece 16b (see FIG. 10) and sent to the conveyance roller 17a. At this time, FIG.
As shown in (b), the feed speed of the separation roller 16a is set lower than the feed speed of the transport roller 17a in order to prevent a jam, and the separation roller 16a follows the sheet and rotates faster than the gear 28. . Then, the second spring clutch 29 is loosened and the separation roller shaft 31 is released, and the separation roller 16a rotates at the same speed as the conveyance roller 17a without applying a load to the conveyed sheet.

In FIG. 12B, the second spring clutch 29
Although the driving force is hardly transmitted to the separation roller shaft 31 because it is in a loose state, a slight idling torque is generated, and the driving is transmitted to the preliminary conveyance roller 33 via the gear 30 and the second idler gear 38. I will. However, in the present embodiment, as shown in FIG. 13, the stop spring 39 enters the flat portion 35b of the preliminary transport roller shaft 35 and acts as a resistance in the rotation direction, and the concave portion of the preliminary transport roller 33 has a transport path (arrow p). Stop in the direction). With this, the transport roller
When the document is conveyed by 17a, the space between the preliminary conveyance roller 33 and the preliminary conveyance pressing plate 54 is always in an open state, the sheet can be conveyed without applying a load, and there is no possibility that the image is disturbed. .

On the other hand, when the trailing edge of the sheet passes through the separation roller 16a, the second spring clutch 29 is tightened again to separate the separation roller 16a.
Is rotated by the driving force transmitted from the gear 28. At the same time, the drive is also transmitted to the separation roller shaft 31 via the mold portion 31a, and the drive is again transmitted to the preliminary transport roller 33 as shown in FIG.

When the DES actuator 42 (see FIG. 10) detects a document, image information is read by the photoelectric conversion element 19 and discharged by the discharge roller 18a.
Thereafter, if the DS actuator 41 detects the document, the above operation is repeated, and the image reading is performed sequentially. Also D
The S actuator 41 has not detected the original and the DE
When the S actuator 42 loses the detection of the document, it determines that a series of image reading has been completed, and performs an initialization operation.

The initialization operation is performed by reversing the driving means. When the driving means is reversed as shown in FIG. 12 (c), the second spring clutch 29 is loosened and the drive transmission to the separation roller 16a is cut off, and the first spring clutch 36 is tightened and conveyed to the preliminary conveyance roller 33. The drive in the opposite direction (the direction of arrow g) is transmitted. That is, the second drive transmission means of the preliminary transport roller 33 is constituted by the first spring clutch 36 via the gear 28, the first idler gear 37, and the clutch shaft 34.

Here, as shown in FIG. 14 (c), a rib 55b as a rotation restricting means is provided at the lower end of the pendulum 55. Therefore, the preliminary transport roller 33 is moved in the direction opposite to the transport direction (direction of arrow g).
When the end 36b abuts on the pendulum 55, the pendulum 55 abuts on the rib 55b and cannot rotate.

Then, the first spring clutch 36 is loosened by the rotational force, and as shown in FIG. 12D, the drive between the clutch shaft 34 and the preliminary transport roller shaft 35 is cut off, and the preliminary transport roller 33 stops. At this time, the end 36a of the first spring clutch 36
Since the phase relationship with the preliminary transport roller 33 is constant as shown in FIG. 8, the preliminary transport roller 33 always stops when the dent portion is directed to the transport path (the direction of the arrow p in FIG. 14C). I do. At the same time, since the flat portion 35b of the preliminary transport roller shaft 35 and the stop spring 39 mesh with each other, the phase of the end portion 36b of the first spring clutch 36 and the concave portion of the preliminary transport roller 33 is slightly shifted due to manufacturing accuracy. Also, the preliminary transport roller 33 can be stopped in the direction of the arrow p.

As a result, the next time a document is inserted, the preliminary transport roller 33 and the preliminary transport pressing plate 54 are released, so that the document can easily and smoothly reach the stopper 46 without being caught. Can be done.

Further, as shown in FIG. 11 (b), when the driving means rotates in the reverse direction, the transport roller 17a rotates in the direction of the arrow g, so that the stopper roller 45 rotates in the direction of the arrow f. And stopper
Although the stopper 46 does not rotate in this direction, the stopper roller 45 also stops rotating and the transport roller 17
a and the stopper roller 45 slip. As a result, the stopper 46 is always in a state of being lowered, and is located at a position where the document is conveyed when the document is inserted, so that the document is not forced into the separation unit.

[0048]

As described above, in the driving device and the image forming apparatus according to the present application, one end of the spring clutch for transmitting the driving force between the shaft on the transmission side and the shaft on the transmission side is projected outward. Providing an abutting member that abuts on the end so that when the spring clutch rotates in the tightening direction, it abuts on the abutting member and loosens, and when the spring clutch rotates in the loosening direction, the abutting member escapes. As a result, the rotation direction of the first transport roller can be controlled without using a solenoid, so that the production cost can be reduced, the size of the apparatus can be reduced, and the assemblability can be improved.

Further, since a flat portion is provided on a part of the shaft on the transmission side and a stopping means is provided for urging the flat portion, a phase shift occurs between the position of the end of the spring clutch and the uneven surface of the first conveying roller. In this case, it can be reliably stopped at a predetermined phase.

Also, by providing a second spring clutch so that the drive of the first transport roller is not applied until the sheet reaches the roller on the downstream side, the first transport roller is moved to the downstream side when one rotation is controlled. Even when the sheet does not reach the arranged transport roller, it is possible to reliably transport the sheet without causing a transport failure.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an apparatus.

FIG. 2 is a central sectional view of the image forming apparatus.

FIG. 3 is a diagram illustrating an overall configuration of the apparatus.

FIG. 4 is a plan view of the cassette.

FIG. 5 is a perspective view of an image recording unit.

FIG. 6 is a plan view of a lower document frame unit.

FIG. 7 is a configuration diagram of a preliminary transport roller unit.

FIG. 8 is a configuration diagram of a separation roller unit.

FIG. 9 is a diagram illustrating the operation of a spring clutch.

FIG. 10 is a plan view of the upper document frame unit.

FIG. 11 is a diagram illustrating a reading drive gear.

FIG. 12 is a diagram illustrating the operation of the sheet feeding device.

FIG. 13 is a diagram illustrating a configuration of a stop spring.

FIG. 14 is a diagram illustrating an operation of initializing a stopper.

FIG. 15 is an external view showing the entire configuration.

FIG. 16 is a side sectional view of the image reading unit.

FIG. 17 is a diagram illustrating the operation of the stopper.

FIG. 18 is a top view of a feeding device of the image reading unit.

[Explanation of symbols]

 A: Feeding system B: Recording system C: Reading system D: Operation unit 1: Feeding cassette 2 ... Recording sheet 3 ... Feeding roller 4 ... Claw 5: Feed roller pair 6 ... Tip detection sensor 7 ... Device body 8 ... Platen roller 9 Cartridge 10a Discharge roller 10b Spur 11 Discharge roller pair 12 Recording cover 13 Document 15 Document tray 16a Separating roller 16b Pressing piece 16c Separating spring 17a Transport roller 17b Transport roller 18a Discharge roller 18b Discharge roller 19 Photoelectric conversion element 20 Platen 21 Carriage 22 Pulley 23 Timing belt 24 Guide rail 25 Motor 26 Lower document frame 27 Separation roller unit 28 Gear 29 Second spring clutch 30… Gear 31… Separation roller shaft 31a… Mold part 32… Preliminary transport roller unit 33… Preliminary transport roller 33a… Groove 34… Clutch shaft 3 5 Preliminary conveyance roller shaft 35a Notch 35b Flat surface 35c Gear 36 First spring clutch 36a End 36b End 37 First idler gear 38 Second idler gear 39 Stop spring 40 Upper document frame 40a … Top document stay 41… DS actuator 42… DES actuator 43… Transport roller shaft 44… Transport roller short 45… Stopper roller 46… Stopper 47… Discharge roller shaft 48… Axis pressing spring 49… Gear 50… Gear 50a… Shaft hole 51… Gear 51a… Shaft hole 52… Transmission shaft 53… Gear 54… Preliminary conveyance pressing plate 54a… Biasing means 55… Pendum 55a… Slope 55b… Rib 56… Transport roller shaft 57… Discharge roller shaft

Claims (4)

[Claims] 1. A non-circular first transport roller for transporting a sheet, first drive transmitting means for transmitting a rotational drive in a sheet transport direction to the first transport roller, and a first transport roller for transmitting a sheet in a sheet transport direction to the first transport roller. A second drive transmission means for transmitting a rotational drive in a reverse direction, and a first spring clutch provided on the second drive transmission means for intermittently driving, and one end of the first spring clutch is internally provided. And connected to the first transport roller, and the other end of the first spring clutch is projected outward at a predetermined phase with respect to the first transport roller. A sheet feeding device, comprising: rotation restricting means for restricting rotation of the first spring clutch in a loosening direction, and stopping at a predetermined phase by rotating the first transport roller in a reverse direction. 2. The sheet feeding device according to claim 1, wherein the predetermined phase is a phase in which a portion having a smallest diameter in a circumferential direction of the first conveying roller faces a sheet conveying surface. Feeder. 3. The apparatus according to claim 1, further comprising: a flat portion provided on a shaft of the first transport roller, and a stopping means for urging the flat portion to stop the first transport roller at the predetermined phase. The sheet feeding device as described in the above. 4. The first drive transmitting means simultaneously transmits a second transport roller disposed downstream of the first transport roller in the sheet transport direction, and both the second transport roller and the first drive transmitting means. And a second spring clutch that independently performs intermittent driving, wherein the third transport roller is driven to rotate at a higher speed than the second transport roller downstream of the second transport roller in the sheet transport direction. The second conveyance roller is driven by the sheet conveyed by the third conveyance roller, whereby the drive transmission from the second spring clutch to the first drive transmission means is substantially disconnected, and the stopping means 4. The sheet feeding device according to claim 3, wherein the first transport roller is stopped at a predetermined phase by the control.