JP3911116B2 - Document reader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a document reading apparatus which is applied to a document information reading unit such as a facsimile machine and has a configuration in which documents are separated and fed one by one and document information is read by the reading unit.
[0002]
[Prior art]
FIG. 3 is a configuration diagram showing a schematic configuration of an example of a conventional document reading apparatus. Reference numeral 1 denotes a pickup roller that feeds a document set on the document setting unit 2 in a conveyance direction (arrow A direction). 1, a separation sheet feeding unit 6 comprising a feed roller 4 and a separation roller 5 for separating and feeding the documents fed one by one one by one is installed below the separation sheet feeding unit 3 so that the document information is optically transmitted. A reading sensor 7 for reading, a reading conveying roller for sending a document sent from the separation sheet feeding unit 3 to the reading sensor 6 at a predetermined speed, and a discharge roller 8 for discharging the document after reading to an external document receiving unit 9. It is a paper roller.
[0003]
The document is conveyed from the document setting unit 2 to the document receiving unit 9 through a substantially U-shaped document conveyance path 10. That is, as shown in the drawing, the document conveyance path 10 is formed so that the conveyance direction is reversed from the right direction to the left direction after passing through the separation sheet feeding unit 3.
[0004]
In the document reading apparatus configured as described above, the document set in the document setting unit 2 is fed in the direction of the separation sheet feeding unit 3 by the pickup roller 1 that descends to the upper surface of the document. In the separation sheet feeding unit 3, a known separation sheet feeding operation is performed by a difference in friction coefficient among the feed roller 4, the separation roller 5, and the documents, and the document is separated one by one and is downstream in the conveyance direction. Sent to.
[0005]
Thereafter, when the leading edge of the document passes through the arc portion 10 a of the document conveyance path 10 and reaches the reading conveyance roller 7, the document is sent to the reading sensor 6 by the reading conveyance roller 7 at a predetermined speed. Information will be read. The read original is discharged to the original receiving portion 9 by the paper discharge roller 8.
[0006]
[Problems to be solved by the invention]
In such a conventional document reading apparatus, in which the document is transported from the separation sheet feeding unit 3 to the reading sensor 6, the document in the reading sensor 6 generated when the trailing edge of the document passes through the separation sheet feeding unit 3. Image fluctuation is an important solution. In particular, as shown in FIG. 3, in a configuration in which a substantially U-shaped document conveyance path 10 is used and the document conveyance direction is reversed between the separation sheet feeding unit 3 and the reading sensor 6, the document stability is improved. Transport becomes more problematic.
[0007]
For this reason, conventionally, the drive system of the separation sheet feeding unit 3 and the drive system of the reading transport roller 7 are made independent, and further, an independent drive motor is installed in each drive system to stabilize the transport of the document. I was trying to prevent fluctuations.
[0008]
However, as described above, installing independent drive motors in a plurality of drive systems complicates the structure and increases costs.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems, and to provide a document reading apparatus in which a document that has passed through a separation sheet feeding unit is stably conveyed in a reading unit and can be driven in a document reading part by a single drive motor. It is to provide.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, in the middle of conveying a document from a separation sheet feeding unit that separates and feeds documents one by one to a reading unit that reads document information, the document conveyance direction is reversed and conveyed. In the document reading apparatus configured as described above, a reading conveyance roller that conveys the document at a predetermined speed with respect to the reading unit is installed upstream of the document conveying direction in the reading unit, and the document conveying direction in the reading unit A paper discharge roller for discharging the document to the outside is installed on the downstream side of the sheet, and a load is applied to the document in the separation sheet feeding unit between the separation sheet feeding unit and the reading conveyance roller, and there is no conveyance load. An original reading apparatus provided with a load removal conveying roller for sending an original to the reading conveying roller, wherein two driving systems receiving rotational driving force from one driving motor are arranged, Drive By driving the conveyor roller the load is removed and the separation sheet feeding portion, the sheet discharge roller and the conveying roller reading the driven by the other drive system, the one of the driving system and gear train structure, of the other The drive system has a belt structure in which a belt is laid in a triangular shape, the gear group structure is disposed in the vicinity of one oblique side of the belt structure, and the conveying force for the document in the separation sheet feeding unit by the load removing conveyance roller And the linear velocity of the load removal conveying roller and the reading conveying roller is set so that the reading conveying roller conveys the document to the reading unit at the predetermined speed. With this configuration, the conveyance load on the document in the separation paper feeding unit is removed by the load removing conveyance roller before the document reaches the reading conveyance roller. Transmission is performed in a stable manner. In addition, by using one drive motor and separating the two drive systems from the drive motor, it is possible to prevent the acting force in the separation sheet feeding unit from being directly transmitted to the reading conveyance roller via the document. Good reading is possible without affecting the linear velocity of the reading conveyance roller. Furthermore, it is possible to set different conditions for both drive systems, and to arrange both drive systems close to each other, making this type of drive system compact without complicating the structure. The cost is not increased.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings.
[0016]
FIG. 1 is a schematic configuration diagram of a document reading apparatus for explaining an embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member corresponding to the member demonstrated in FIG. 3, and detailed description is abbreviate | omitted.
[0017]
The difference between the apparatus shown in FIG. 1 and the apparatus shown in FIG. 3 is that a load removing conveyance roller 11 is installed in the document conveyance path 10 between the separation sheet feeding unit 3 and the reading conveyance roller 7. By differentiating the linear velocity between the reading conveyance roller 7 and the load removal conveying roller 11, the load removal conveying roller 11 absorbs the conveyance load applied to the document applied in the separation paper feeding unit 3, and the reading is performed. This prevents the acting force such as the tension from the separation sheet feeding unit 3 from being directly transmitted to the conveying roller 7.
[0018]
FIG. 2 is a configuration diagram of a drive system in the present embodiment, in which 20 is a drive motor, 21 is a drive pulley provided on the output shaft 22 of the drive motor 20, and 23 is provided coaxially with the reading transport roller 7. 1 is a driven pulley, 24 is a second driven pulley provided coaxially with the paper discharge roller 8, and 25 is a belt provided on the driving pulley 21, the first driven pulley 23, and the second driven pulley 24. Thus, a reading drive system is configured.
[0019]
Reference numeral 26 denotes a drive gear provided on the output shaft 22 of the drive motor 20, 27 denotes a gear group including a plurality of intermediate gears that receive rotational driving force from the drive gear 26, and 28 denotes a coaxial with the load removal conveying roller 11. A driven gear that is provided and receives a rotational driving force from the gear group 27, and further, a rotational driving force is transmitted from the driven gear 28 to the separation sheet feeding unit 3 via a gear group (not shown). Thus, a separating and conveying drive system is configured.
[0020]
As described above, in this embodiment, two drive systems, that is, the read drive system and the separation transport drive system are arranged from one drive motor 20, and torque fluctuations are transferred from the load removal transport roller 11 to the read transport roller 7. Since direct conveyance is prevented so that the conveyance load in the separation sheet feeding unit 3 is not transmitted to the reading conveyance roller 7, the linear velocity in the reading conveyance roller 7 does not change, and the reading sensor 6 has a good condition. Reading is possible.
[0021]
Further, torque fluctuation transmitted through the output shaft 22 of the drive motor 20 is unavoidable, but it can be said that there are few problems because this fluctuation is extremely small. However, in this embodiment, in order to suppress the influence of the fluctuation as much as possible, belt driving is adopted in the reading drive system. That is, by driving the belt, the torque fluctuation is absorbed by the back tension, the bending of the belt, and the like so that the fluctuation is not transmitted to the reading conveyance roller 7, thereby affecting the linear velocity of the reading conveyance roller 7. Can not be. For this reason, coupled with making the reading drive system a drive system independent of the separation transport driving system, it is possible to read with very little jitter in the reading sensor 6.
[0022]
【The invention's effect】
As described above, according to the present invention, in a document reading apparatus configured to transport a document by reversing the transport direction of the document while transporting the document from the separation paper feeding unit to the reading unit that reads document information, Since the conveyance load for the document in the paper portion is removed by the load removal conveyance roller, the conveyance of the document to the reading unit by the reading conveyance roller is stably performed , and the driving is performed using one drive motor. By separating the motor from the two drive systems, it is possible to prevent the acting force in the separation paper feeding unit from being directly transmitted to the reading conveyance roller via the original, thereby affecting the linear velocity of the reading conveyance roller. Therefore, good reading is possible. Furthermore, it is possible to set different conditions for both drive systems, and to arrange both drive systems close to each other, making this type of drive system compact without complicating the structure . The cost is not increased.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a document reading apparatus for explaining an embodiment of the present invention. FIG. 2 is a configuration diagram of a drive system in the embodiment of the present invention. FIG. 3 is a schematic configuration of an example of a conventional document reading apparatus. Configuration diagram showing [Description of symbols]
3 Separation Paper Feeding Unit 6 Reading Sensor 7 Reading Conveyance Roller 10 Document Conveyance Path 11 Load Relief Conveyance Roller 20 Drive Motors 21, 23, 24 Pulley 25 Belt 26 Drive Gear 27 Gear Group 28 Driven Gear

Claims (1)

In a document reading device configured to reverse and transport a document in the middle of conveyance from a separation feeding unit that separates and feeds documents one by one to a reading unit that reads document information,
A reading conveyance roller that conveys the document at a predetermined speed with respect to the reading unit is installed on the upstream side in the document conveying direction in the reading unit , and the document is externally provided on the downstream side in the document conveying direction in the reading unit. A paper discharge roller is installed, and receives a conveyance load for the document in the separation sheet feeding unit between the separation sheet feeding unit and the reading conveyance roller, and the document is transferred to the reading conveyance roller without a conveyance load. A document reading apparatus provided with a load removing conveyance roller for sending,
Two systems of driving systems that receive a rotational driving force from one driving motor are arranged, one of the driving systems drives the separation sheet feeding unit and the load-removing transport roller, and the other driving system transports the reading transport. Driving the roller and the paper discharge roller ,
The one drive system has a gear group structure, the other drive system has a belt structure in which a belt is installed in a triangular shape, and the gear group structure is disposed in the vicinity of one oblique side of the belt structure,
The load removal conveyance roller absorbs the conveyance force for the document in the separation sheet feeding unit by the load removal conveyance roller, and conveys the document to the reading unit by the reading conveyance roller at the predetermined speed. A document reading apparatus characterized in that a linear velocity between the scanning roller and the reading conveying roller is set.

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