JPH03279140A - Image reader - Google Patents

Abstract

PURPOSE:To restrain a script from unnecessarily shifting so as to precisely read an image by arranging a reading roller, movably in the vertical direction, relative to a contact glass pane, which roller has a frictional coefficient larger than that of the contact glass pane and which is adapted to transfer the script while pressing the same against the contact glass pane. CONSTITUTION:A reading roller 19 is provided movably in the vertical direction, relative to a contact glass pane 12, the roller 19 having a frictional coefficient which is greater than that of the contact glass pane 12 and being adapted to transfer a script S while pressing the same against the contact glass pane 12. Further, a script reading position P for an optic system 13 is set on the paper discharge side in the vicinity of the reading roller 19. as a result, the reading roller 19 transfers the script S while pressing the same against the contact glass 12 in the vicinity of the reading position P on the paper discharge side. Thereby, it is possible to restrain the script S from unexpectably shifting, relative to the reading position P, so as to allow the optic system 13 to precisely read the image.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image reading device that can be applied to copying machines, printers, facsimile machines, and the like.

(Prior Art) FIG. 3 is a configuration diagram of a conventional image reading device, in which numeral 30 is a pick-up roller that is in contact with the topmost one of the stacked originals S, 31 is a feed roller that is in contact with a paper feed roller 32, 33, 34 is a pair of conveying rollers, 35 is a contact glass, 36 is a paper ejection guide having an inclined portion fixed on the contact glass 35, 37 is a pair of paper ejection rollers, 38
Reference numeral 39 denotes a guide plate, numeral 39 is a known optical system for reading an image on the transported original S, and P represents the reading position of the optical system 39 relative to the original.

In the figure, a document S is conveyed by a pick-up roller 30 to a separation roller 31 and a paper feed roller 32.

When a plurality of documents S are conveyed, the document separation action by the reverse rotation of the separation roller 31 is performed, and - number of documents are conveyed. Further, the document S is conveyed onto a contact glass 35 by a pair of conveying rollers 33 and 34, and the image is read at a reading position P by an optical system 39. Reading of the original S is performed sequentially, and when the leading edge of the original S is guided by the paper ejection guide 36 and reaches a position where it is held between the paper ejection roller pair 37, the original S is ejected by the paper ejection roller pair 37. It will be discharged onto a tray, etc.

(Problems to be Solved by the Invention) In the above-mentioned conventional apparatus, when the document S is conveyed,
The leading edge contacts the paper ejection guide 36 and is slightly layered, and also contacts the paper ejection roller pair 37 and is slightly layered, so that
That is, it may move in the sub-scanning direction of reading by the optical system 39. This movement in the sub-scanning direction also occurs when the rear end of the document S comes off the conveyance roller pair 34.

The above-mentioned movement of the original S in the sub-scanning direction causes unnecessary movement of the original S with respect to the reading position flP of the optical system 39, which causes abnormalities in the read image data (image elongation,
There was a problem in that it caused shrinkage.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading apparatus that can suppress unnecessary movement of a document at a reading position and perform accurate reading.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an image reading device that can read an image of a document conveyed onto a contact glass by fixing the position of an optical system. A reading roller, which has a coefficient of friction larger than the contact glass and which conveys the original while pressing it against the contact glass, is provided so as to be movable up and down with respect to the contact glass, and the optical system is provided on the paper ejection side near the reading roller to read the original. It is characterized by having a location.

(Function) Because the above method is adopted, when reading image information, the reading roller conveys the document while pressing it against the contact glass near the reading position on the paper ejection side, which prevents the document from moving inadvertently relative to the reading position. is suppressed, and reading by the optical system is performed accurately.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a configuration diagram of an embodiment of the present invention, and FIG. 2 is a configuration diagram showing the state of the embodiment of FIG. Motor, 3 is motor 2
4 is a paper feed roller; 5 is a paper feed pulley that is provided on the shaft 4a of the paper feed roller 4 and receives the rotational force of the motor pulley 3 via a first belt 6; 7; 8 is a calling roller provided on the lower side of the document receiving plate 1; 8 is a calling pulley that is provided on the shaft 7a of the calling roller 7 and receives rotation of the paper feed pulley 5 via the second belt 9; 10 is a calling pulley; A stopper spring 1 that engages with a part of the calling roller 7 to restrict rotation of the calling roller rough;
Reference numeral 1 denotes a leading edge detection sensor that is installed on an extended portion of the document receiving plate 1 and detects the leading edge of the document S; 12 is a contact glass;
a is a paper discharge guide provided on the contact glass 12; 13 is a known optical system for reading the image of the original S; P;
is the reading position of the optical system 13 with respect to the document S, 14 is a separation roller installed opposite to the paper feed roller 4, 15 is provided on the shaft 14a of the separation roller I4, and A separation pulley 17 receives the rotation of the paper pulley 5; a movable guide plate 17 has one end extending below the separation roller 14 and the other end provided in the center of the operating lever 18; and 19 a movable guide plate for reading the movable guide plate 17. A reading roller 20 is provided above the position P and has a larger friction coefficient than the contact glass 12; 20 is a reading pulley that is provided on the shaft 19a of the reading roller 19 and receives rotation of the paper feed pulley 5 via a fourth belt 21; , 22 is a paper discharge roller provided at one end of the operating lever 18 so as to be retractable relative to the discharge side guide plate 23, and 24 is a support shaft inserted into a long hole 25 formed at the other end of the operating lever 18. , 26 is a spring pulling the other end of the operating lever 18 upward;
7 is a stopper that restricts the rotation of the operating lever 18; 2;
Reference numeral 8 denotes a paper ejection pulley that is provided on the shaft 22a of the paper ejection roller 22 and receives the rotation of the reading pulley 20 via the fifth belt 29.

In FIG. 1, when the motor 2 is rotated counterclockwise in the direction of arrow A, the motor pulley 3 is rotated counterclockwise via the one-rotation shaft 2a. As the motor pulley 3 rotates, the paper feed pulley 5 rotates via the first belt 6, rotating the paper feed roller 4 counterclockwise, and the calling pulley 8 rotates via the second belt 9. Then, rotate the calling roller 7 counterclockwise. By the rotation of this pick-up roller rough, the lower part of the document S is conveyed in the direction of the paper feed roller 4. At this time, when a plurality of documents S are sent to the paper feed roller 4, the separation roller 14 receives the rotational force of the paper feed pulley 5 via the third belt 16 and the separation pulley 15, and rotates counterclockwise. Therefore, out of the plurality of originals S, feeding of the upper one is stopped, and only the lowest original S is conveyed toward the contact glass 12. Further, the leading edge of the original S transported one by one by the paper feed roller 4 is detected by the leading edge detection sensor 11, and the original S is transported to the reading position P. In this case, the outer peripheral surface of the pick-up roller rough needs to have a length that can transport the document S to the reading position IfP.

FIG. 2 is a configuration diagram showing the operating state during reading in the above embodiment. When the document S is conveyed to the reading position P, the rotation restriction of the operating lever 18 by the stopper 27 is released by a driving means (not shown). The operating lever 18 receives the force of the spring 26 and rotates counterclockwise about the support shaft 24. This rotation of the operating lever 18 causes the reading roller 19 to descend together with the movable guide plate 17, and the reading reroller 19 presses the original S against the contact glass 12. At this time, the reading position P is the reading reroller 1
It is configured to be located near 9 and on the paper ejection side.

In this state, the motor 2 is rotated clockwise.

Then, the rotational force of motor 2 is applied to motor pulley 3. First belt 6, paper feed pulley 5. It is transmitted to the reading IJ 20 via the fourth belt 21, and rotates the reading roller 19 clockwise. Since the friction coefficient of the reading roller 19 is larger than that of the contact glass 12, the document S is
The paper is conveyed in the paper ejection direction by the rotation of 9, and the reading position IMF
A known image is read by the optical system 13. At this time, the paper feed roller 4, separation roller 14, and calling roller 7
By providing a one-way clutch (not shown) that can rotate in one direction, the paper feed roller 4 and the separation roller 1 can be
4 rotates under the force of moving the original S by the reading roller 19, and the calling roller 7 is stopped under the control of the stopper spring 10.

In this way, in this embodiment, the reading position I! By providing P on the paper ejecting side of the contact point between the reading roller 19 and the contact glass 12, the reading operation can be performed while suppressing unnecessary movement of the original S by the reading roller 19, and image information can be read reliably. Ru.

Further, during the above-described reading operation, the paper ejection roller 22 is rotated.

By rotating the operating lever 18 in the counterclockwise direction, it enters a position lower than the paper discharge side guide plate 23 and does not come into contact with the document S. Therefore, unnecessary movement at the reading position of the document S [P] Even less.

Reading accuracy is improved.

After the reading of the original S is completed, the operating lever 18 is rotated clockwise about the support shaft 24 by a suitable driving means, and each part returns to the state shown in FIG. 1. In this state, a portion of the paper ejection roller 22 protrudes from the paper ejection side guide plate 23, and as the motor 2 rotates counterclockwise, the motor pulley 3, the first belt 6, the paper feed pulley 5.
Fourth belt 21. Reading pulley 20. Fifth belt 29. It rotates counterclockwise via the paper ejection pulley 28, and the document S is ejected to a paper ejection tray (not shown) or the like.

(Effects of the Invention) According to the present invention, unnecessary movement of the document at the reading position is suppressed by the reading roller that conveys the document while pressing it against the contact glass, making it possible to read images accurately and improve image quality. An image reading device can be provided.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of an image reading device of the present invention, FIG. 2 is a configuration diagram showing the state of the embodiment of FIG. 1 during a reading operation, and FIG. 3 is a configuration diagram of a conventional image reading device. It is a diagram. 2...Motor, 4...Paper feed roller, 7...
・Call roller, 12...contact glass, I3・
...Optical system, 14... Separation roller, 17... Movable guide plate, 18... Operating lever 19... Reading re-roller, 22... Paper discharge roller, P... Reading position,
S...Manuscript.

Claims (1)

[Claims] In an image reading device capable of reading an image of a document conveyed onto a contact glass by fixing the position of an optical system, a reading roller has a coefficient of friction larger than that of the contact glass and conveys the document while pressing the document against the contact glass. is provided so that it can move up and down relative to the contact glass,
An image reading apparatus further comprising: a reading position of the optical system for the original document provided on the paper discharge side near the reading roller.