JPH04169444A - Sheet conveyer - Google Patents

Abstract

PURPOSE:To surely perform sheet conveyance of the second conveying means without generating a diagonal feed condition by driving the second conveying means in a sheet conveying direction for a predetermined time while the first conveying means conveys a sheet brought into contact with the second conveying means for the predetermined time. CONSTITUTION:In a sheet 2 fed by a feed roller 5, a point end of the sheet collides against a contact part, formed between a conveying roller 10 and a read means 9, to correct an attitude of the sheet 2, and further the sheet is conveyed till a circular arc-shaped loop is formed by a detection signal of a sheet end detecting sensor. Thereafter, the conveying roller 10 absorbs a predetermined play angle, rotates for a predetermined time in a document conveying direction and holds the sheet 2 in cooperation with the read means 9. In this way, the sheet 2 is held before force in a direction of returning a document is generated in the sheet 2, so that giving and receiving of the document 2 from the first conveying means X to the second conveying means Y are surely performed to surely convey the sheet 2 to the downstream by the second conveying means Y without generating improper conveyance such as retracting the sheet 2 brought into contact with the conveying roller 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention is directed to image reading devices such as scanners and facsimiles
The present invention relates to a sheet conveying device provided.

(b) Conventional technology The sheet conveying system of an image reading device such as a scanner or facsimile is generally equipped with a sheet conveying device of the following type. That is, along the conveyance direction of the sheet,
A first conveying means for conveying the sheet is provided on the upstream side, a second conveying means for conveying the sheet is provided on the downstream side, and the first conveying means is driven to transfer the sheet to the second conveying means. After making contact and further conveying for a predetermined time, the second conveying means is driven to convey the sheet to the downstream side.

FIG. 7 shows an image reading device equipped with a conventional sheet conveying device of the above type.

In the figure, reference numeral 1 denotes an image reading device, and a sheet conveying section in the image reading device 1 includes a run-up roller 3, a feeding roller 5, A first conveying means X consisting of separating rollers 6 is also provided. Further, on the downstream side thereof, there is provided a second conveying means Y consisting of a reading means (contact type image sensor) 9 and a conveying roller 10 which is pressed against the reading means at a predetermined pressure in the reading line. The first conveying means X disposed on the upstream side and the second conveying means Y disposed on the downstream side constitute a sheet conveying device.

Note that reference numeral 11 is a sensor provided between the first conveyance means X and the second conveyance means Y for detecting a document.

In such a sheet conveying device, the feeding roller 5 is driven counterclockwise (in the direction of the arrow) to convey the sheet 2 downstream, and the leading edge of the sheet 2 is brought into contact with the reading means 9 and the conveying roller 10. After the sheet 2 is abutted against the contact portion a and the sheet 2 is further conveyed to correct the skew by forming a loop, the second conveyance means Y is driven clockwise and the sheet 2 is read by the reading means 9 while the sheet 2 is read by the arrow It is designed to be discharged to the outside like this. During this operation, the separation roller 6 is constantly driven counterclockwise (in the direction of the arrow) via a torque limiter (not shown) to prevent double feeding of the sheets 2.

(c) Problems to be solved by invention However, in the above conventional sheet conveying device,
Conveyance roller 10 of the second conveyance means Y to perform reading conveyance
is driven in the document conveying direction (clockwise) shown by the arrow, and when the conveying roller 10 and the reading means 9 are about to sandwich the sheet 2, the feeding roller 5 of the first conveying means As a result, the separation roller 6 or the sheet 2 is driven in the return direction, that is, in the clockwise direction, and the leading edge of the sheet 2 that has abutted against the abutting portion a retreats from that position, and the second conveying means Y
In some cases, the sheet 2 cannot be held between the conveyance roller 10 and the reading means 9, which is a problem (defect in conveyance).

In this case, it may be possible to consider a method of stopping the driving of the feeding roller when the sheet 2 is sandwiched between the reading means 9 and the conveying roller 10. With this method, the posture of the sheet 2 cannot be corrected, and the reading It is not practical because skew occurs due to the position.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a sheet conveying device that can reliably convey sheets by a second conveying means without causing a skewed state. This is the purpose.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention, for example, as shown with reference to FIGS.
, a first conveying means (X) for conveying the sheet (2) is provided on the upstream side, and a second conveying means (Y) for conveying the sheet (2) is provided on the downstream side thereof, The first conveying means (X) is driven to transport the sheet (2) to the second conveying means (X).
Y) and further conveyed for a predetermined time, the second
The present invention relates to a sheet conveying device that drives a conveying means (Y) to convey the sheet (2) to the downstream side.

Further, in the present invention, the power transmission means (8) for transmitting driving force to the second transport means (Y) is connected to the first transport means (X).
) or sheet (2) is brought into contact with the second conveyance means (Y), and while the sheet (2) is further conveyed for a predetermined time, the second conveyance means (Y)
is characterized in that it is configured to be driven in the sheet conveyance direction for a predetermined period of time.

Further, the power transmission means (Z) of the second conveyance means (Y) is configured to transmit the driving force from the single drive source (17) to the second conveyance means (Y). That is.

(E) Effect According to the above configuration, when the sheet (2) conveyed by the first conveying means (X) contacts the second conveying means (Y) and forms a loop, it is held between the second conveying means (Y). and then transported downstream by the second transport means (Y).

Thereby, the second conveying means (Y) can reliably convey the sheet (2) without causing it to skew.

Note that the above reference numerals in parentheses are only used to refer to the drawings, and do not limit the structure in any way.

(f) Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows the overall configuration of a sheet conveying device according to the present invention, FIG. 2 shows a first conveying means section in the same sheet conveying device, and FIG. 3 shows a second conveying means section in the same sheet conveying device. It is something.

Note that, like the conventional sheet conveying apparatus shown above, this sheet conveying apparatus has a first conveying means consisting of a run-up roller, a feeding roller, and a separation roller, and a reading line for a reading means (contact type image sensor). and a second conveying means consisting of a conveying roller that is pressed against the conveyor roller with a predetermined pressure. Here, the same members as those in the conventional example described above are given the same reference numerals and their explanations will be omitted.

On the body 12 of the image reading device, there are a rotating shaft 13 to which the feeding roller 5 of the first conveying means X is attached (see FIG. 2), a rotating shaft 15 to which the separating roller 6 of the first conveying means X is attached. (See Fig. 2), conveyance roller 1 as second conveyance means Y
A rotary shaft 16 (see FIG. 3) to which a rotor 0 is attached is disposed. The rotational power of a motor 17 serving as a single drive source is transmitted to each of the rotating shafts 13, 15, and 16 via power transmission means, which will be described later.

One end of the rotating shaft 13 to which the gear 19 is fixed is the gear 19
It is rotatably supported by the body 12 via a sleeve 19a. Further, the other end of the rotating shaft 13 is rotatably supported by the body 12 via a bearing 20 fixed to the body 12. A gear 21 is fixed to the other end (
(See Figure 2). The gear 19 includes a gear 23 fixed to the output shaft 17a of the motor 17 fixed to the side surface of the fuselage 12;
They mesh with each other through gears 25 and 27, so that rotational power from the motor 17 is transmitted to the rotating shaft 13. Note that the gears 25 and 26 are integrally formed coaxially.

A feeding roller 5 and a pair of left and right levers 29 are rotatably mounted on the rotating shaft 13.
A pulley 30 is fixed to 3. The rotating shaft 13 and the feeding roller 5 are connected via a one-way rotating clutch 31. As a result, the feeding roller 5 is equipped with a motor 17 that rotates clockwise when the document is transported (arrow A in FIG. 1).
Rotational power is transmitted from the rotor to rotate in the direction of the arrow in FIG. On the other hand, when the document is transported in the opposite direction (first
At arrow B) in the figure, the rotational drive from the motor 17 is cut off by the one-way rotation clutch 31. 1 pair of levers 2
9 , a rotating shaft 32 is rotatably supported in a state substantially parallel to the rotating shaft 13 . A run-up roller 3, a pulley 33, and left and right friction rollers 35 are fixed to the rotating shaft 32. Further, a compression spring 36 is interposed between the pulley 33 and the run-up roller 3 and each friction roller 35, so that the friction roller 35 is moved closer to the lever 29.
is pressed against the side of the

A timing belt 3 is installed between the pulley 33 and the pulley 30.
7 is stretched, and the rotational power from the rotating shaft 13 is transmitted to the run-up roller 3. In addition, the friction roller 35 and the pulley 33 on the left side in FIG. 2, and the run-up roller 3 and the friction roller 35 on the right side are engaged with each other at engaging portions (not shown) and rotate as one. ing. By the rotation of the rotating shaft 13 in the direction of the arrow shown in FIG.
The run-up roller 3 is brought into contact with the document by the rotational force around the rotating shaft 13 generated by the compression spring 36, and separated by rotation in the opposite direction.

There is a rotating shaft 1 on the fuselage 12 that is a predetermined distance away from the rotating shaft 13.
5 is rotatably supported via bearings 40, 40 (see FIG. 2). A gear 41 is attached to one end of the rotating shaft 15 via a spring clutch 42 (see FIG. 4).

As a result, a rotational driving force in the document returning direction (arrow B in FIG. 1) is transmitted from the motor 17 to the rotating shaft 15. In this case, gear 41 meshes with gear 26 via gear 43.

A drum 45 is fixed on the rotating shaft 15, and a pulley 46 and a pair of left and right support plates 47 are rotatably supported. The drum 45 and pulley 46 are connected by a spring clutch 49. A pair of left and right support plates 4
9 , a rotating shaft 50 is rotatably supported in a state substantially parallel to the rotating shaft 15 . A pair of left and right separation rollers 6.6 and a pulley 51 are fixed on the rotating shaft 50. A timing belt 52 is installed between the pulley 51 and the pulley 46.
is installed. As a result, the rotating shaft 50 is rotationally driven by the rotational force of the rotating shaft 15 with a predetermined tolerance (idling torque) in the document return direction B by the spring clutch 49 . A separation roller 6.6, which rotates integrally with the rotating shaft 50, is pressed against the feeding rollers 5, 5 with a predetermined pressure by a spring (not shown).

A gear 53 is connected to a spring clutch 55 on the other end side of the rotating shaft 15.
It is attached via. This gear 53 is gear 56
．． 57 and is engaged with the gear 21, and transmits the rotational drive of the rotary shaft 13 to the rotary shaft 15 in the document return direction (arrow B in FIG. 1). Therefore, when the separation roller 6.6 is rotated by the motor 17 in the forward rotation direction (in the direction of the arrow in FIG. 2), the gears 23, 25.26, 43.4
1 and a spring clutch 42, the rotational power of the motor 17 is transmitted. In addition, when the motor 17 is rotationally driven in the reverse direction, the gears 23, 25, 26, 27, 19
, the rotational power of the motor 17 is transmitted to the separation roller 6.6 via the rotating shaft 13, the gears 21°57, 56, 53, and the spring clutch 55. In this case, the separation roller 6.6 is
A predetermined tolerance value (spring clutch 49
It is driven with a idling torque of

In FIG. 3, the fuselage 1 downstream of the first conveyance means
2, a rotating shaft 16 to which a conveying roller 10 as a second conveying means Y is fixed is rotatably supported via bearings 59, 59. A gear 61 is attached to one end of the rotating shaft 16 via a one-way rotation clutch 62.
This gear 61 meshes with the gear 43. Further, a gear 63 or a one-way rotation clutch 6 is provided at the other end of the rotating shaft 16.
It is attached via 5. As shown in FIG. 5, the engagement portion of the gear 63 with the one-way rotation clutch 65 is configured such that the gear 63 transmits the rotational power of the motor 17 to the rotation shaft 16 with an idle angle θ of a predetermined rotation angle. It is an arcuate notch 66 formed within the range of angle θ. Gear 63 meshes with gear 21 via gears 66, 67. Therefore, when the motor 17 rotates in the normal rotation direction (in the direction of the arrow in FIG. 2), the transmission of rotational power is delayed, and the gear 63
After absorbing the play angle θ set in , rotational power in the document conveyance direction is transmitted to the conveyance roller 10. This gear 63, 66.6
A gear train Z consisting of 7.21 transports the sheet 2 as a document for a predetermined time while the first transport means X brings the sheet 2 as an original into contact with the second transport means Y and further transports the sheet for a predetermined time. It is a power transmission means for driving in the direction. The timing at which the conveyance roller 10, which is the second conveyance means Y, starts rotating is determined by the play angle θ. Further, when the rotational direction of the motor 17 is switched from normal rotation to reverse rotation, the rotational power of the motor 17 in the document conveyance direction is transmitted to the conveyance roller 10 without delay.

Note that the reading means (contact type image sensor) 9 is in pressure contact with the conveying roller 10 at a predetermined pressure at its reading line (FIG. 1). .

Next, the operation of this sheet conveying device will be explained with reference to FIGS. 6(a) to 6(g).

First, when a feeding command is issued from an operation section (not shown), the motor 17 starts rotating in the forward direction (in the direction of the arrow in FIG. 2). The rotation of the motor 17 rotates the run-up roller 3 and the feed roller 5 in the counterclockwise direction.
is descending. Further, the separation roller 6 is driven to rotate in the sheet return direction, or rotates clockwise following the feeding roller 5 while pulling the idling torque of the spring clutch 49 (
Figure 6(a)).

When the descending run-up roller 3 comes into contact with the uppermost sheet 2 on the document stacking table (not shown), the sheet 2 is sent downstream (FIG. 6(b)).

In this case, when two or more sheets 2 are sent out at the same time by the run-up roller 3, the separation roller 6 sends back only the upper sheet 2 due to the idling torque of the spring clutch 49 (FIG. 6(C)).

The leading end of the sheet 2 fed by the feeding roller 5 abuts against a contact portion 9 formed between the conveying roller 10 and the reading means 9, and the posture of the sheet 2 is corrected. The sheet 2 is further conveyed until an arc-shaped loop is formed by a detection signal from a sheet end detection sensor (not shown) provided between the feed roller 5 and the conveyance roller 10 (see FIG.
)) In this case, depending on the paper quality of the sheet 2, the environment, the feeding force of the feeding roller 5, etc., a loop may not be formed and the sheet may remain in contact (as indicated by the dotted line in the figure).

After that, the conveyance roller 10 absorbs the predetermined play angle θ, and
It rotates in the document conveyance direction for a predetermined period of time, and cooperates with the reading means 9 to nip the sheet 2 (FIG. 6(e)). As a result, the conveyance roller 1
0 and the reading means 9 sandwich the sheet 2.
The transfer of the sheet 2 from the first conveyance means 2 is transported downstream by transport means Y.

When the feeding of the sheet 2 is completed by the feeding roller 5, the motor 17 starts to rotate in reverse, thereby causing the conveying roller 10 to rotate clockwise and the reading means 9 to grip and convey the sheet 2. Start reading. Further, the feeding roller 5 follows the sheet 2 with its rotational drive cut off by the one-way rotation clutch 31. Further, the separation roller 6 also rotates following the sheet 2. The run-up roller 3 rotates clockwise around the rotating shaft 13 and retreats (raises) from the sheet 2 (FIG. 6(f)).

Then, the rear end of the sheet 2 is connected to the feed roller 5 and the separation roller 6.
, the separation roller 6 rotates in the direction of returning the document (counterclockwise), and the feeding roller 5 rotates following the separation roller 6. Further, when the trailing edge of the sheet 2 passes between the transport roller 10 and the reading means 9, the document reading operation is terminated by a detection signal from a document edge detection sensor (not shown).
Figure 6(g)).

Thereafter, when the motor 17 starts rotating in the forward direction, the state shown in FIG. 6(a) is restored and the sheet 2 is repeatedly fed.
Perform a read operation.

In addition, in this embodiment, the gear 63 and the spring clutch 65
A delay mechanism (
The notch 66) can also be constructed using an electromagnetic solenoid or the like.

Further, although this embodiment is an example of a configuration using a contact type image sensor 9, if the contact type image sensor 9 is configured as a conveyance roller, an automatic document feeding device in an image reading device can be easily configured. .

(g) As described in detail of the invention, in the sheet conveying device of the present invention, the power transmission means for transmitting driving force to the second conveying means is arranged such that the first conveying means brings the sheet into contact with the second conveying means. Since the second conveyance means is configured to drive the sheet in the sheet conveyance direction for a predetermined time while the sheet is further conveyed for a predetermined time, the second conveyance means can reliably convey the sheet without causing it to skew.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall configuration of a sheet conveying device according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional plan view showing the first conveying means section of the same sheet conveying device in an unfolded state, and FIG. 3 is the same. FIG. 4 is a cross-sectional plan view showing the second conveying means section of the sheet conveying device in an unfolded state; FIG. FIG. 5 is a perspective view showing a gear and a spring clutch that transmit the rotational power of the motor to the rotating shaft of the conveyance roller as the second conveyance means, and FIGS. 6(a) to (g) are explanations of the operation of the sheet conveyance device. 7 are longitudinal sectional side views showing a conventional sheet conveying device. 2... Seat, 17... Motor (single drive source),
X...first conveyance means, Y-...second conveyance means,
Z... Gear train (power transmission means for transmitting driving force to the second conveyance means). Figure 4 Figure 5 Figure 6 (a) (b) Figure 6 Figure 7

Claims (1)

[Claims] 1. Along the sheet conveying direction, a first conveying means for conveying the sheet is provided on the upstream side, and a second conveying means for conveying the sheet is provided on the downstream side thereof, In a sheet conveying device of a type in which the first conveying means is driven to bring the sheet into contact with the second conveying means, and after further conveying for a predetermined time, the second conveying means is driven to convey the sheet to the downstream side. , a power transmission means for transmitting driving force to the second conveyance means,
The sheet conveying device is characterized in that the second conveying means is driven in the sheet conveying direction for a predetermined time while the first conveying means brings the sheet into contact with the second conveying means and further conveys the sheet for a predetermined time. Device. 2. The sheet conveyance device according to claim 1, wherein the power transmission means of the second conveyance means is configured to transmit driving force from a single drive source to the second conveyance means.