JPH01256268A - Original reader - Google Patents

Abstract

PURPOSE:To enhance the reliability of original carrying by providing a power switching means delivering or interrupting a torque from a drive means driving the 1st and 2nd carrier means to or from the 1st carrier means. CONSTITUTION:A torque switching means 27 delivers a torque from a drive means 31 to the 1st carrier means 5 and carries an original M to the 2nd carrier means 17 by the 1st carrier means 5. Then the torque switching means 27 delivers the torque from the drive means 31 to the 2nd carrier means 17 and the original M is carried to an original read means 19 by the 2nd carrier means 5 to read a picture. Thus, the drive means 31 drives a carrier roller 5 and a platen roller 17 to enhance the reliability of original carrying.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a document reading device used in an image forming apparatus such as a facsimile machine, and more specifically, the present invention relates to a document reading device that reads an image of a document while conveying the document. Regarding a reading device.

(B) Prior Art Conventionally, there has been known a document reading device that reads an image of a document while conveying the document.
As shown in FIGS. 6 to 7, it has a document tray 2 on which a large number of documents M are stacked. A conveying roller 5 connected to a motor 3 via a gear 4 is rotatably supported on the downstream side of the tray 2, and one end of the roller 5 is in contact with the machine body 6 on the lower side. The separation pad 9 is pressed against the roller 5 by the screw 7 . Further, a support plate (not shown) is rotatably supported by the shaft lO of the conveyance roller 5, and a shaft 12 is supported by these support plates. Further, a pickup roller 13 is rotatably supported on the shaft 12, and the roller 13 is configured to be driven by a belt (not shown) from the conveyance roller 5. And, downstream of the separation pad 9,
A sheet edge sensor 15 is disposed to detect the edge of the document M, and downstream of the sensor 15, a gear 1 is connected to a motor 11.
A platen roller 17 connected via a roller 6 is also provided. Further, a direct reading sensor 19 for reading the image of the document M is disposed facing the roller 17, and a paper discharge tray 20 is disposed downstream of the sensor 19. Furthermore, a peeling plate 21 for peeling the document M from the platen roller 17 is disposed at the base end of the tray 20 .

Then, when a document M is loaded on the document tray 2 and a start key (not shown) is pressed, the motor 3 starts rotating, and the rotation of the motor 3 is transmitted to the conveying roller 5 via the gear 4. The rotation is transmitted to the pickup roller 13 by a belt (not shown). Then, the originals M on the original tray 2 are fed to the transport roller 5 by the pickup roller 13, separated one by one by the roller 5 and the separation bat 9, and only the uppermost original M is transported downstream. Furthermore, when the leading edge of the document M is detected by the sheet edge sensor 15, the motor 3 is activated for a predetermined time, that is, the document M
It rotates for a sufficient time to reach the platen roller 17 and then stops. Then, after a predetermined time, the motor 11 starts rotating, and the rotation of the motor 11 is transmitted to the platen roller 17 via the gear 16. Then, the manuscript M is
It is conveyed while being held between a platen roller 17 and a direct reading sensor 19, and the image is read by the sensor 19 at this time. Furthermore, when the trailing edge of the document M is detected by the sheet edge sensor 15, the motor 11 rotates for a predetermined period of time, that is, a time sufficient for the document M to be discharged onto the discharge tray 20, and then stops. Thereby, the document M is discharged onto the paper discharge tray 20 by the platen roller 17. Then, by the same operation as described above, the originals M on the original tray 2 are sequentially read with a certain interval between the originals M, and are ejected to the paper ejection tray 20.

(c) Problems to be Solved by the Invention By the way, in the above-mentioned original reading bag fl a, the receiving of the originals M from the conveyance roller 5 to the platen roller 17 is difficult due to the necessity of passing the originals and ensuring that there is a gap between the originals M. Conveyance roller 5
Since two motors 3 and 11 are required to separately drive the printer and platen roller 17, the cost increases, and the control of these motors 3 and 11 is complicated, which poses problems in the reliability of document conveyance. .

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a document reading device in which a transport roller and a platen roller are driven by one driving means, thereby solving the above-mentioned problems.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, as shown with reference to FIGS. A document reading device (1) comprising a means (5) and a second conveyance means (17) for conveying the document (M) conveyed by the first conveyance means (5) to the document reading means (19). , the first and second conveying means (5, 17
); a driving means (31) for driving the driving means (31);
The apparatus is characterized in that it includes a power switching means (27) for transmitting or cutting off power from at least the first conveying means (5).

(E) Function Based on the above-mentioned configuration, the power switching means (27) is configured as a drive means (
31) to the first conveyance means (5), and the first conveyance means (5) transfers the document (M) to the second conveyance means (1).
7). The power switching means (27) transmits the power from the driving means (31) to the second conveying means (17), and the second conveying means (5) transfers the document (M) to the document reading means (19). ) and read the image.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to one drawing.

Note that the same parts as those described above are given the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 1 to 3, the document reading device l has the following functions:
The body 6 has chassis 22.22 on the front side and the back side, and a shaft 23.25 is fixed to the chassis 22. A shaft 26 of the platen roller 17 serving as m-th feeding means is rotatably supported by the bearing 23.23, and one end of the shaft 26 has a gear 29 (a )(b) are fitted. Further, a shaft lO is rotatably supported by the bearings 25, 25,
A gear 30 incorporating a negative direction clutch 27 is fitted to one end of the shaft lO. Furthermore, these gears 29.30
A motor 31 is disposed near the motor 31.
The gear 32 fixed to the output shaft of the gear 29.
It meshes with 30. In the figure, the reference numeral 33 is a swinging arm that is supported by the shaft lO and supports the sleeve 12, and the reference numeral 35 is a belt that transmits power from the conveyance roller 5 to the pickup roller 13.

As shown in FIG. 5, the one-way clutch 27 is constructed by housing a steel ball 37 in a tapered groove 36 carved on the inner diameter side of the gear 29 or 30.
0 and has a ratchet structure.

In detail, Fig. 2 shows the gear 30°: 12 in Fig. 4,
cc at the line connecting the centers of 29(a) and 29(b)
It represents the Ityr surface view.

In the figure, 29(a) and 29(b) one-way clutch 2
The gear 29(a) has the same shape as the gear 8 built-in, and the gear 29(a) is directly connected to the gear 32 fixed on the shaft of the motor 31.

Figure 3 shows gear 32, 53.29 (a) in Figure 4.
, 29(b) represents a DD cross-sectional view taken along a line connecting the centers of FIG. In the figure, the gear 29(a) is connected to the gear 32 on the motor 31 via an idler gear 53 which is rotatably fixed on the boss of the chassis. When both of the one-way clutches built into the gears 29(a) and 29(b) rotate in the direction of the dashed line arrow shown in FIG. It is configured as follows.

The operation of the document reading device using this drive mode will be explained.

Since this embodiment has the above-described configuration, when a large number of originals M are placed on the original tray 2 and a start key (not shown) is pressed, the motor 31 is rotated in one direction, that is, gear 3.
2. Rotate in the direction of arrow B.

By rotating the gear 32 in the direction of the broken line arrow shown in the first figure, the second
The first conveyance means consisting of the rotating shaft 26 and the t51 conveyance roller 5 is driven in the document conveyance direction. On the other hand gear 3
Since the gear 29(a) directly connected to the gear 29 is driven in the direction opposite to the broken line arrow shown in FIG. Furthermore, since the gear 29(b) connected to the gear 32 via the idler gear 53 is driven in the direction of the broken line arrow shown in FIG.
This action drives the second rotating shaft 26 and the second conveying roller 17 in the direction of the broken line arrow in FIG.

The leading edge of the document separated and conveyed by the first conveyance roller 5 is detected by a sensor 15 and reaches a second conveyance means consisting of a second conveyance roller 17 and a driven roller 50, which rotate in the direction of the broken line arrow in FIG. The motor 31 is then rotated from the detection signal of the sensor 15 until it reaches a predetermined reading start position of the document or below the sensor 19a of the imaging type reading sensor 19, and then stops.

Next, by rotating the motor 31 in the reverse direction, the gear 32 is rotated in the direction of the dashed arrow shown in FIG.

The gear 30 idles on the first rotation fd+10 by the action of the built-in positional clutch 27, and the first conveyance roller 5 is not driven. On the other hand, since the gear 29(a) is driven by the gear 32 in the direction of the broken line arrow shown in FIG.
7 in the direction of the broken line arrow shown in FIG. Also, gear 2
9(b) is driven by the idler gear 53 in the opposite direction of the dashed line arrow in FIG.

During this time, the document transported by the second transport roller 17 is read, and the first transport roller 5 is idled. In this way, the original is transferred and received from the first conveyance means to the second conveyance means reliably. Then, the rear edge of the document is detected by sensor 15.
After rotating the motor 31 by a predetermined feed amount based on the detection signal, the motor 31 is stopped and reversely rotated again.

As a result, the drive is transmitted to the first @ feed roller 5 to separate and convey the next original, but at least the first
111 has a corresponding sag between the feed roller 5 and the sensor 15. During this time, the second conveyance roller 17 continues to convey the previous document.

As for the predetermined feed amount of the motor 31, the minimum value can be arbitrarily selected from zero (immediately after the sensor 15 detects the trailing edge of the original), and the interval between the originals can be arbitrarily selected. The time setting is controlled by a timer or the like via a control circuit (CPU).

In addition, as a method of connecting the gear 32 and the gears 29(a) and 29(b), in the case of the gear 29(a), an even number of gears including zero may be used between the gear 32 and the gear 32 (see FIG. 2). (equivalent to zero) does not matter. On the other hand, in the case of gear 29(b), gear 32
It does not matter if an odd number of gears are interposed between the two (FIG. 3 corresponds to one gear).

Regarding the one-way clutches 27 and 28 used as drive switching means, various types can be selected in addition to the structure shown in FIG. 4.

It is also possible to use a direct reading sensor as the reading means.

According to the above embodiment, the following effects can be achieved.

(1) By switching between forward and reverse rotations, a single drive source can reliably transfer documents between the first conveyance means and the second conveyance means, and it is possible to set a constant interval between documents.

(2) The interval in (1) above can be set arbitrarily to shorten the interval between documents.

(3) Wear of the 111th feeding means was reduced.

[Effects of the Invention] As explained above, when the single drive source rotates in one direction, the drive is transmitted to the first conveyance means and the second conveyance means in the document conveyance direction, and when the single drive source rotates in the other direction, the drive is transmitted to the second conveyance means in the document conveyance direction. A drive switching means is provided that transmits the drive and cuts off the drive of the first transport means, and uses a signal that detects the edge of the document to rotate the drive source in forward and reverse directions and stop it. A sheet with high reading accuracy that ensures reliable transfer of documents between a first conveyance means and a second conveyance means, allows setting of a fixed or arbitrary interval between documents, and reduces wear on the first conveyance means. It is possible to obtain a document conveyance/reading device.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the main parts of the document reading device according to the present invention, and FIG. 2 is a plan sectional view taken along the line C-C in FIG. 4, showing the document reading device according to the present invention. Figure 3 is the same <
It is a DD sectional view. FIG. 4 is a side sectional view showing the drive section. Moreover, FIG. 5 is a sectional view of the one-way clutch. 6 and 7 are side sectional views showing a conventional example. 1, la... Original reading device, 5... First conveyance means,
17.51...Second conveyance means, 19.19'...Document reading means, 27,39.40...Power switching means, 3
1... Drive means 1M... Original.

Claims (1)

[Claims] (1) A first conveyance means for conveying a plurality of stacked originals downstream and a second conveyance means for conveying the originals for reading are arranged in this order, and the reading means for reading and the A detection means for detecting the edge of the document is provided downstream of the first conveyance means, and when the single drive source rotates in one direction, the first and second conveyance means are driven in the direction in which the document is conveyed, and when the single drive source rotates in the other direction, The second conveyance means has a drive switching means that operates so that drive is transmitted in the direction in which the document is conveyed and the drive of the first conveyance means is cut off, and the document conveyed by the first conveyance means is When the detection means, the second conveyance means, and the reading means are reached, the drive source is sequentially stopped and reversely rotated at predetermined intervals based on the signal obtained by the detection means, and the document is read by the second conveyance means and the reading means. A document conveyance and reading device that performs conveyance and reading.