JPH11258868A - Document feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately read an image by preventing defect in straight advancing such as the obliquely advancing and the meandering of a document. SOLUTION: When an operator closes a document feeding mechanism part 20, an elastic member 43 arranged below a reading plate 5 displaces the plate 5 in an up-and-down direction so as to make the plate 5 abut on a roll 10 as the roll 10 on the lower part of the part 20 obliques with respect to the plate 5 in a shaft center direction X. Document feeding force by the roll 10 obtained when the part 20 is closed is uniformized in the shaft center direction X of the roll 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder attached to a document reading device such as an electrophotographic copying machine, and more particularly, to a document feeding device having a document feeding mechanism which can be opened and closed with respect to a reading plate. About.

[0002]

2. Description of the Related Art Conventionally, for example, an original reading apparatus in an electrophotographic copying machine reads an image while fixing an original (hereinafter referred to as an original fixed type), and reads an image while moving the original (hereinafter referred to as an original). (Called a mobile type).

An electrophotographic copying machine provided with both the former original fixed type and the latter original reading device has an original conveying device for conveying an original along a predetermined original conveying path. The original conveying device is disposed above an electrophotographic copying machine, and has a glass for reading a movable original and a glass for reading a fixed original arranged side by side on an upper surface of a main body of the copying machine, and a shape for covering both the glasses. The lower part has an axis parallel to the reading area of the moving original reading glass and faces the moving original reading glass and is driven to rotate so that the original is sandwiched between the moving original reading glass and the original conveying direction. It has a platen roll that is transported downstream, and has a predetermined document transport path and the like that transports the document on the document placement unit to the document discharge unit via the reading area of the moving document reading glass, A document transport mechanism that can be opened and closed with respect to the two glasses with a support portion at one end side (back side as viewed from the operator) as a fulcrum;
Consists of

According to this document feeder, in the fixed document type, for example, an operator places a document on a fixed document reading glass having a reading area larger than the size of the document and closes the document transfer mechanism. Then, while moving in the sub-scanning direction a light source for irradiating the original in the main scanning direction and an optical system including a reflecting mirror for reflecting the reflected light of the original illuminated by the light source, the light is reflected by the reflecting mirror. The reflected light thus received is received by a document reading unit including a one-dimensional image sensor such as a CCD (Charge Coupled Device) and the image of the document is read.

On the other hand, in the original moving type, the platen roll abuts on a moving original reading glass having a reading area having a size corresponding to a predetermined number of lines of the original in a state where the original transport mechanism is closed, and the platen roll is moved. By rotating the original, the original from the original placing portion is transported downstream in the original transport direction while being sandwiched between the original and the movable original reading glass, and is directed to the original discharge portion. When the document passes through at a predetermined speed, the light source and the optical system are fixed at the reading position in the reading area, and the image of the document is read by the document reading unit.

[0006]

However, in the document feeder having the above structure, a coil spring is arranged on the support so that the operator can open the document feed mechanism with a small force when opening the document feed mechanism. Since the forcible lifting force is applied, the forcibly lifting force in the opening direction causes the front side of the document transport mechanism, as viewed from the operator, to float with respect to the moving document reading glass and to be in front of the platen roll. The side part does not come into contact with the moving document reading glass, and a difference in transport force (nip pressure difference) due to the platen roll occurs between the back side and the near side of the apparatus. There is.

If the front side of the original transport mechanism is forcibly closed, the original transport mechanism is bowed, and the back and the center of the original are lifted.
Similarly, skew or meandering occurs in the document.

Japanese Patent Application Laid-Open No. 5-204209 discloses that a pair of bearings which are provided coaxially with the rotation axis of a platen roll, face the platen roll therebetween, and have a larger diameter than the platen roll. There has been proposed a document feeder in which the document supporting glass as the moving document reading glass described above is urged by a leaf spring and pressed. However, this configuration only has a predetermined gap between the platen roll and the document supporting glass. Is provided.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and equalizes the original conveying force of a roll facing a reading plate in a roll axis direction when an original conveying mechanism is closed, thereby obliquely moving the original. It is another object of the present invention to provide a document feeder capable of preventing a rectilinear failure such as meandering and reading an image accurately.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a document feeder according to the present invention comprises a document feeder for feeding a document along a predetermined document feed path. A reading plate made of a light-transmitting material having a reading area of a few minutes in size and a shape covering the reading plate, and having an axis parallel to the reading area at a lower portion, facing the reading plate and rotationally driven; A document transport mechanism that has a roll that transports the document downstream in the document transport direction while sandwiching the document between the document and the reading plate, and that can be opened and closed with respect to the reading plate with one end of the axis as a fulcrum; And an elastic member that displaces the reading plate vertically so that the reading plate abuts on the roll according to the inclination of the roll with respect to the reading plate when the document conveying mechanism is closed. It is characterized by.

According to the thus configured document feeder of the present invention, when the document feed mechanism is closed by the operator, the elastic member disposed below the reading plate causes the roll of the roll below the document feed mechanism to move. Since the reading plate is displaced in the vertical direction so as to abut against the roll in accordance with the inclination of the reading plate in the axial direction, the document conveying force of the roll when the document conveying mechanism is closed is equal in the roll axis direction. Be transformed into For this reason, the document is transported straight, and the rectilinear defects such as skew and meandering of the document are prevented.

The roll is located upstream and downstream of the reading area in the document transport direction when the document transport mechanism is closed, and the reading plate is made of a material having a smaller coefficient of friction than the reading plate. It is preferable that the reading area is at least opened and surrounded by a surrounding member that covers a position where the reading area comes into contact with the roll.

When such a configuration is adopted, the original is
Since the rolls located upstream and downstream in the document transport direction from the reading area of the reading plate are transported downstream in the document transport direction while being sandwiched between the reading plate by the rotation drive of the rolls, the document is transported upstream and downstream from the upstream roll in the document transport direction. The influence of, for example, a document collision or a change in the posture of the document that occurs downstream of the roller on the document transport direction is suppressed by the upstream and downstream rolls, and transmission to the reading area is suppressed. For this reason, speed fluctuation in the reading area is prevented. In addition, since the roll is disposed so as not to be located above the reading area of the reading plate, the reading area of the reading plate is not rubbed by the roll, and of course, is not stained. Also,
The friction coefficient of the surrounding member, which is the contact surface of the roll, is smaller than that of the reading plate (low friction coefficient), so that when the contact pressure (nip pressure) of the roll is increased, the bounding of the roll is prevented. Is done. Therefore, the contact pressure of the roll against the surrounding member can be increased, and the speed fluctuation of the document in the reading area can be further prevented. Further, since at least a portion corresponding to the reading area of the reading plate of the surrounding member is opened,
The optical path for image reading is not blocked by the surrounding member. In addition, since the reading plate is surrounded and integrated by the surrounding member, when a member having a smaller coefficient of friction than the reading plate is individually provided, for example, by sticking, corresponding to the position where the reading plate abuts on the roll, Compared with this, the work is facilitated and the reading plate is prevented from being damaged during carrying and assembling.

Further, it is preferable that a portion of the surrounding member that contacts the upstream roll is higher in height than a portion of the surrounding member that contacts the downstream roll.

When such a configuration is adopted, the original in the reading area floats with respect to the reading plate, so that unfixed material such as correction liquid or ink on the original is placed in the reading area on the reading plate. In addition to preventing the members from being attached, members having a smaller coefficient of friction than the reading plate can be easily made higher in height than when individually provided, for example, by sticking, corresponding to the position where the reading plate comes into contact with the roll. You.

Further, when the document transport mechanism is closed, the latch engages with the document transport mechanism and keeps the height of the reading plate in the reading area inclined in accordance with the inclination of the roll in the axial direction. It is preferred to have a part.

When such a configuration is adopted, the original image surface in the reading area on the reading plate is positioned at the focal point of the original reading section for reading the image information of the original, so that the degree of closing of the original transport mechanism is increased. Then, if the latch section is engaged, the image is always read out of focus.

Further, the elastic member is preferably a compression spring. When such a configuration is adopted, the reading plate is satisfactorily displaced in accordance with the inclination of the roll with respect to the reading plate in the axial direction, so that poor rectilinearity such as skew and meandering of the document can be prevented well.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a document feeder according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partially cutaway front view showing the document feeder according to the first embodiment, FIG. 2 is a partially cutaway right side view of the document feeder shown in FIG. 1, and FIG. FIG. 4 is a partially cut-away enlarged view showing the vicinity of a reading plate of the document feeder shown in FIG. 1, and FIG. 5 is a partial cutaway view showing the vicinity of a reading plate of the document feeder shown in FIG. It is a partially broken enlarged view.

The document feeder of the first embodiment is applied to, for example, an electrophotographic copying machine having both a document moving type and a document fixed type document reading device. As shown in FIGS. 1 and 2, the document feeder according to the present embodiment is provided on an upper portion of an electrophotographic copying machine 15 and has a moving document reading glass (reading plate) disposed on an upper surface of a copying machine main body 16. )
5, a fixed document reading glass 17 and a guide member 6 positioned between the glasses 5 and 17, and a document transport mechanism 20 having a shape covering the movable document reading glass 5, the guide member 6 and the fixed document reading glass 17. ing.

The reading area A for reading an original from below the moving original reading glass 5 is
And a substantially linear area extending in a direction (a direction perpendicular to the paper surface of FIG. 1) orthogonal to the document transport direction (the left-right direction in FIG. 1) on the glass 5. It has a size equivalent to the number of rows (lines). A reading area D for reading an original from below the fixed original reading glass 17 has an area equal to or larger than the original size, and is set on almost the entire surface of the fixed original reading glass 17.

The guide member 6 disposed between the movable original reading glass 5 and the fixed original reading glass 17 has an inclined guide surface 6b which is continuously inclined upward on the movable original reading glass 5. In addition, the movement of the moving document reading glass 5 from the reading area A (see FIGS. 1 and 4) upstream of the document transport direction (left side in the figure; the upstream in the document transport direction is simply referred to as upstream, and the downstream in the document transport direction is simply referred to as downstream). On the original reading glass 5, a step portion 11 that forms a step above the reading area A is provided. The step portion 11 is made of, for example, a resin and has a low coefficient of friction, which is lower than a glass material having a high coefficient of friction.

The document transport mechanism 20 includes a document discharge tray 21 having a shape covering the fixed document reading glass 17, and a document set tray 3 disposed above the document discharge tray 21.
A first roll 10 disposed at a lower portion, and a document placed on the document set tray 3 on a moving document reading glass 5 on a guide surface 6.
a, 6b, and a predetermined document transport path 7a, 7b, 7c leading to the document discharge tray 21, a nadja roll 13 disposed along the document transport paths 7a, 7c from the upstream to the downstream, and a pair of feed rolls 8 , A pair of takeaway rolls 2
2, a pair of resist rolls 14, a pair of first discharge rolls 9, and a pair of second discharge rolls 23.

As shown in FIGS. 1 to 3, the first roll 10 is located at the back and front sides (a direction perpendicular to the paper surface of FIG. 1) of the lower portion of the document transport mechanism section 20 as viewed from the operator; Are fixed to the first roll shaft 10a rotatably (split in parallel with the reading area A) over the X-direction (referred to as X direction). It is arranged in.

As shown in FIG. 3, a plurality of the first discharge rolls 9 are provided at positions corresponding to the first rolls 10, and are parallel to the first roll shaft 10a. Is fixed to the first discharge roll shaft 9a which is stretched over the first discharge roll shaft 9a. The first discharge roll shaft 9a is connected to a motor 4 installed on the back side (upper side in FIG. 3) of the document transport mechanism 20.
0 is rotated through the timing belt 41 and the first
Of the timing belt 4 stretched between the first discharge roll shaft 9a and the first roll shaft 10a.
2, the roller is rotated in the same direction at the same speed as the first discharge roll shaft 9a.

The original transport mechanism 20 is provided in the copying machine main body 1.
6 is supported by a support portion 19 disposed on the back side of the movable document reading glass 5 on the upper surface, that is, on one end side of the first roll shaft 10a (on the other side of the paper surface of FIG. 1). The guide member 6 and the fixed original reading glass 17 can be opened and closed, and a force for forcibly lifting in the opening direction is applied by a coil spring 37 (see FIG. 2) disposed on the support portion 19. When the document transport mechanism 20 is closed, the document discharge tray 21 is moved to the fixed document reading glass 17.
And the other portion of the document transport mechanism 20 covers the movable document reading glass 5 and the guide member 6.

An original conveying path 7a for guiding the original on the original set tray 3 onto the moving original reading glass 5 is connected to the original discharge tray 2
Since the document set tray 1 and the document set tray 3 are arranged side by side in the vertical direction, a U-turn path is provided so that the document set on the document set tray 3 is reversed and guided on the moving document reading glass 5. Also, an original transport path 7 on the movable original reading glass 5
“b” is formed by closing the document transport mechanism 20.

Below the reading glasses 5, 17 and the guide member 6, a light source for irradiating the reading area A in the main scanning direction is provided.
An optical system including a reflection mirror or the like that reflects the light reflected from the original in the reading area A illuminated by the light source, and C that reads the image of the original by receiving the light reflected by the reflection mirror.
And a document reading unit including a one-dimensional image sensor such as a CD.

In particular, in this embodiment, the position of the copying machine main body 16 facing the moving original reading glass 5 is slightly larger than the moving original reading glass 5 and the lower position facing the four corners of the moving original reading glass 5. As shown in FIGS. 4 and 5, a bracket 44 extends from the copying machine main body 16 side, and a cylindrical stud 46 is provided on the upper surface of the bracket 44 and is compressed so as to wind around the stud 46. A spring (elastic member) 43 is disposed,
The moving original reading glass 5 is placed on the compression spring 43.

That is, in the present embodiment, the moving original reading glass 5 is supported vertically in a state where it is placed on a compression spring 43 disposed below the four corners of the moving original reading glass 5. A guide member 45 mounted on a compression spring 43 for guiding the movable document reading glass 5 in a floating state is provided on the front side and the back side of the upper surface of the copying machine main body 16 with the moving document reading glass 5 interposed therebetween. Is installed. The guide member 45 regulates the movement of the movable document reading glass 5 in the X direction (a deviation during tilt described later is allowed) and a compression spring 43 when the document transport mechanism 20 is open. And a bent portion 45b that abuts on the upper surface of the movable document reading glass 5 urged upward by the above to hold the upper surface at a predetermined reference position. This reference position is set at a position higher than the upper surface of the moving document reading glass of the related art.

Further, as shown in FIGS. 1 and 2, the original transport mechanism 20 is closed on the near side of the original transport mechanism 20 and on the upper side of the fixed original reading glass 17 on the upper surface of the copying machine main body 16. Occasionally, hook-shaped latch portions 39a and 39b made of spring materials engaging with each other at a predetermined height position are provided. These latch portions 39a, 39b
Is released by operating the opening / closing lever 38 provided on the document transport mechanism 20 and connected to the latch 39a.

According to the thus configured original conveying apparatus, when reading an image while fixing the original, the operator places the original on the fixed original reading glass 17 and closes the original conveying mechanism 20. Thereafter, a predetermined start switch is turned on. Then, for example, the light source and the optical system move below the fixed document reading glass 17 in the sub-scanning direction, and the document image is read by the document reading unit.

On the other hand, when reading an image while moving the original, the original is transported with the original transport mechanism 20 closed. When the operator closes the original transport mechanism 20, the first roll 1 on the back side below the original transport mechanism 20 is moved.
Reference numeral 0 first contacts the moving original reading glass 5, and further, the first roll 10 on the back side and the first roll 10 on the near side sequentially contact the moving original reading glass 5. At this time, since the compression spring 43 contracts and the movable document reading glass 5 is inclined in accordance with the inclination of the document transport mechanism unit 20 (first roll 10), all the first rolls 10 extending from the back side to the front side are inclined. Abuts on the moving original reading glass 5 via the step 11 therebetween.

In this state, when the operator presses the original transport mechanism 20 slightly downward against the urging force of the compression spring 43, the latch 39a on the original transport mechanism 20 side and the latch section on the copier body 16 side. 39b engages. By this engagement, the vertical position of the moving original reading glass 5 is made constant, and the original image surface on the moving original reading glass 5 is positioned at the focal point of the above-described original reading section.

When a document is placed on the document set tray 3 by an operator and a predetermined start switch is turned on, the motor 40 and the like are operated to rotate the above-described series of rolls. Najarol 1
3, transported to the first roll 10 by the feed roll 8, the take away roll 22, and the registration roll 14,
The document is further conveyed by the first roll 10 through the reading area A of the moving document reading glass 5 with the document conveying direction changed upward on the inclined guide surface 6b of the guide member 6, and further, the first and second discharge rolls 9 and 23, the document discharge tray 21
Is discharged. When a document passes over the reading area A of the moving document reading glass 5 at a predetermined speed, the light source and the optical system are fixed at a position to be read in the reading area A of the moving document reading glass 5, and the document information is read by the document reading unit. Is read.

Here, in the process of transporting the document downstream while sandwiching the document by the rotation of the first roll 10, as described above, the moving document reading glass 5 is moved along the inclination of the first roll 10 by the compression spring 43. The first roll 10 tilted
, The original conveying force of the first roll 10 when the original conveying mechanism 20 is closed is equalized in the roll axis direction. For this reason, the original is transported while traveling straight, and it is possible to prevent straightness defects such as skew and meandering of the original.
As a result, accurate image reading can be performed.

When the latch portions 39a and 39b are engaged, the position of the movable document reading glass 5 in the vertical direction is fixed, and the document image surface on the movable document reading glass 5 is focused on the document reading portion. The document transport mechanism 20
When the latches 39a and 39b are engaged each time
It is possible to read images with focus. For this reason, more accurate image reading is possible.

When the trailing edge of the original in the reading process passes through the registration roll 14 upstream of the reading area A, the attitude of the original changes, and the attitude of the trailing edge of the original changes in the scanning area A. However, in this embodiment, even after the trailing edge of the original has passed through the registration roll 14, the first roll 1 near the upstream of the reading area A in the present embodiment.
The sheet is conveyed to the reading area A while being sandwiched between the step portion 11 by the rotation of 0. For this reason, the influence of the change in the posture of the document upstream of the first roll 10 is suppressed by the first roll 10, transmission to the reading area A is suppressed, and the reading caused by the change in the posture of the rear end of the document is suppressed. A change in the speed of the document in the area A is prevented.

Further, if the contact pressure of the first roll 10 is increased when the friction coefficient of the step portion 11 contacting the first roll 10 is high, there is a possibility that the first roll 10 may bound, and the reading may be performed. Although it is not possible to sufficiently prevent the speed fluctuation in the region A, in the present embodiment, the friction coefficient of the step portion 11 is reduced so as not to cause the bounding (the friction coefficient of the moving document reading glass 5 is made smaller). Therefore, the contact pressure (nip pressure) of the first roll 10 against the step portion 11 can be increased, and the speed fluctuation of the document in the reading area A is further prevented.

Further, since the first roll 10 is arranged not in the reading area A but in the upstream of the reading area A, the reading area A of the moving original reading glass 5 is rubbed and stained by the first roll 10. Never.

Since the original is conveyed to the reading area A via the step 11, the document is floating in the reading area A, and unfixed material such as correction liquid and ink on the original is transferred to the reading area A. It is prevented from sticking.

Further, since the movable original reading glass 5 is displaced by following the inclination of the first roll 10 by the compression spring 43, the displacement can be made good and the original can be skewed and meandered. It is possible to further prevent poor straightness.

As a result, accurate image reading becomes possible.

FIG. 6 is a partially cutaway front view showing the vicinity of a reading plate of the document feeder according to the second embodiment, and FIG.
FIG. 3 is a top view showing a unit section of the original transport device of FIG.

The difference between the original conveying apparatus of the second embodiment and that of the first embodiment is that
A second roll 12 facing the moving original reading glass 5 is provided, and the moving original reading glass 5 is surrounded by a surrounding member 50 to form an integrated unit 51, which is a moving unit having the step portion 11 of the first embodiment. This is the point that the original reading glass 5 is disposed instead.

Here, the second roll 12 is provided with a second roll shaft 12 arranged in parallel with the first roll shaft 10a.
a, and is driven by the above-described motor 40 so as to be rotated in the same direction at the same speed as the first roll 10.

The surrounding member 50 is made of, for example, resin and has a low coefficient of friction, which is lower than that of a glass material having a high coefficient of friction. As shown in FIG. 7, the surrounding member 50 has an opening 50 a at an upper portion corresponding to the reading area A.
However, openings 50b are respectively formed in the lower portion so as not to block the optical path for image reading.

The upstream roll contact portion 50c on the upstream side with the opening 50a in the upper portion of the surrounding member 50 interposed therebetween.
Is higher than the downstream roll contact portion 50d on the downstream side with the opening 50a interposed therebetween. This height relationship is
This is the same as the height relationship between the upper surface of the step portion 11 and the upper surface of the movable document reading glass 5 described in the first embodiment. And
The heights of the upper surface of the upstream roll contact portion 50c and the upper surface of the downstream roll contact portion 50d when the document transport mechanism 20 is open are the same as those in the first embodiment when the document transport mechanism 20 is open. The height of the upper surface of the step portion 11 and the height of the upper surface of the movable document reading glass 5 substantially match each other.

The unit 51 is integrated by, for example, inserting the movable document reading glass 5 into the surrounding member 50 and adhering the two 5, 50 with, for example, an adhesive.

Even when the unit 51 having such a configuration is used, the first and second rolls 10 and 12 contact the upstream and downstream roll contact portions 50c and 50d by closing the document conveying mechanism unit 20. Since the compression spring 43 contracts and the unit 51 inclines according to the inclination of the original transport mechanism 20, the original transport force by the first and second rolls 10 and 12 when the original transport mechanism 20 is closed is reduced by the roll axis. Equalized in the direction. For this reason, as in the first embodiment, it is possible to prevent straightness defects such as skew and meandering of a document, thereby enabling accurate image reading.

Further, according to the second embodiment, the first
The following effects can be obtained in addition to the embodiment.

That is, the original is conveyed downstream while being sandwiched between the downstream roll contact portion 50d by the rotation drive of the second roll 12 before colliding against the inclined guide surface 6b of the guide member 6. You. The original collides with the inclined guide surface 6b of the guide member 6 after traveling straight, but the influence of the collision is suppressed by the second roll 12 and transmission to the reading area A is suppressed. The speed fluctuation of the document in the area A is prevented.

Further, since the second roll 12 is arranged not in the reading area A of the moving original reading glass 5 but upstream of the reading area A, the reading area A of the moving original reading glass 5
The upper portion is not rubbed by the second roll 12 and becomes dirty.

Also, since the friction coefficient of the surrounding member 50, which is the contact surface of the second roll 12, is smaller than the moving original reading glass 5 (low friction coefficient), as in the first embodiment, The bounding of the second roll 12 that occurs when the contact pressure (nip pressure) of the second roll 12 is increased is prevented. Therefore, the contact pressure of the second roll 12 with respect to the upstream roll contact portion 50d can be increased, and the speed fluctuation of the document in the reading area A is further prevented.

Since the portion of the surrounding member 50 corresponding to the reading area A of the moving original reading glass 5 is opened, the optical path for image reading is not blocked by the surrounding member 50.

As a result, accurate image reading becomes possible.

Further, since the moving original reading glass 5 is integrally formed by being surrounded by the surrounding member 50, a member having a friction coefficient smaller than that of the moving original reading glass 5 can be replaced with the first and second moving original reading glasses 5. In comparison with the case where the reading plates are individually provided in correspondence with the positions contacting the rolls 10 and 12, for example, the work is facilitated, and the reading plate is prevented from being damaged at the time of carrying and assembling.

Also, since the upstream roll contact portion 50c on the upstream side of the reading area A of the surrounding member 50 is made higher with respect to the downstream roll contact portion 50d on the downstream side as a unit, the moving original reading glass The first and second rolls 1 of the moving original reading glass 5
The height is made easier to be set, as compared with the case where it is individually provided, for example, by sticking, corresponding to the positions contacting 0 and 12.

As a result, manufacturing costs can be reduced.

The elastic member is not limited to the compression spring 43. Further, the surrounding member 50 has at least openings in the upper portion and the lower portion corresponding to the reading area A, and covers the portion where the first and second rolls 10 and 12 abut. The shape is not limited as long as it can be surrounded and integrated.

[0061]

According to the document conveying apparatus of the present invention, when the operator closes the document conveying mechanism, the elastic member disposed below the reading plate causes the roll below the document conveying mechanism to move in the axial direction of the roll. Since the reading plate is displaced vertically so as to abut on the roll following the inclination, and the original conveyance force by the roll when the original conveyance mechanism is closed is equalized in the roll axis direction. The rotation of the document causes the document to go straight, thereby preventing a rectilinear defect such as skew and meandering of the document, and enables accurate image reading.

Further, the original is transported downstream in the original transporting direction while being sandwiched between the reading plate by the rotation of the rolls located upstream and downstream of the reading area of the reading plate in the original transporting direction. The effect of, for example, a collision of a document or a change in the orientation of the document, which occurs downstream of the rolls in the document transport direction from the rolls in the transport direction upstream and downstream, is suppressed by the upstream and downstream rolls so as to suppress transmission to the reading area. In addition, speed fluctuations in the reading area can be prevented. In addition, since the roll is arranged so as not to be over the reading area of the reading plate,
Needless to say, the reading area of the reading plate is rubbed by the roll and becomes dirty. Further, the friction coefficient of the surrounding member serving as the contact surface of the roll is set to a friction coefficient smaller than that of the reading plate to prevent the roll from bounding which occurs when the contact pressure of the roll is increased. The contact pressure against the surrounding member can be increased, and the speed fluctuation of the document in the reading area can be further prevented. Further, since at least a portion corresponding to the reading area of the reading plate of the surrounding member is opened, the optical path for image reading is not blocked by the surrounding member. As a result, more accurate image reading becomes possible. Further, since the reading plate is surrounded by the surrounding member and integrated, a member having a friction coefficient smaller than that of the reading plate is individually provided, for example, by sticking, corresponding to the position where the reading plate comes into contact with the roll. Work can be facilitated, and the reading plate can be prevented from being damaged at the time of carrying and assembling, and the manufacturing cost can be reduced.

Further, the portion of the surrounding member that contacts the upstream roll is made higher with respect to the portion that contacts the downstream roll, so that the document in the reading area floats on the reading plate. It is possible to prevent the unfixed material such as the correction liquid and the ink from adhering to the reading area on the reading plate, and to set a member having a friction coefficient smaller than that of the reading plate in a position where the member abuts on the reading plate roll. The height can be easily increased as compared with the case where the individual parts are provided by, for example, sticking, and more accurate image reading can be performed, and the manufacturing cost can be further reduced.

Further, the height of the reading plate in the reading area, which is inclined following the inclination of the roll in the axial direction, is kept constant by the latch which engages with the original conveying mechanism when the original conveying mechanism is closed. The original image surface in the reading area on the reading plate,
Since the document can be positioned at the focal point of the document reading unit that reads the image information of the document, if the latch unit is engaged each time the document transport mechanism is closed, the image will always be in focus and the image can be read more accurately. .

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a document feeder according to a first embodiment.

FIG. 2 is a partially cutaway right side view of the document feeder shown in FIG.

FIG. 3 is a top view illustrating a main part of the document conveying device in FIG. 1 in an extracted manner;

FIG. 4 is a partially cutaway enlarged view showing the vicinity of a reading plate of the document feeder of FIG. 1;

FIG. 5 is a partially cutaway enlarged view showing the vicinity of a reading plate of the document feeder shown in FIG. 2;

FIG. 6 is a partially cutaway front view showing the vicinity of a reading plate of a document feeder according to a second embodiment.

FIG. 7 is a top view showing a unit of the document feeder shown in FIG. 6;

[Explanation of symbols]

5. Moving original reading glass (reading plate), 7a, 7b, 7c
... Document feed path, 10 ... first roll (upstream roll), 10a ... first roll axis (upstream roll axis),
12: second roll (downstream roll), 12a: second
Roll shaft (roll shaft on the downstream side), 19 ... support portion, 20
... Document transport mechanism, 39a, 39b.
Compression spring (elastic member), 50 ... surrounding member, 50a, 50
b: opening, 50c: upstream roll contact part, 50d: downstream roll contact part, 51: unit, A: reading area.

Claims (4)

[Claims] 1. A document transport device for transporting a document along a predetermined document transport path, comprising: a reading plate made of a light-transmitting material having a reading area for a predetermined number of rows for reading a document to be transported; Has a central axis parallel to the reading area at the bottom, and is conveyed downstream in the document conveying direction while sandwiching the document between the reading plate by rotating and facing the reading plate. And a document transport mechanism that can be opened and closed with respect to the reading plate with one end of the shaft center as a fulcrum. When the document transport mechanism is closed, the document transport mechanism is disposed below the reading plate. An original conveying device, comprising: an elastic member that vertically displaces the reading plate so that the reading plate comes into contact with the roll according to the inclination of the roll with respect to the reading plate in the axial direction. 2. The roll is located upstream and downstream of the reading area in the document transport direction when the document transport mechanism is closed, and the reading plate is made of a material having a smaller coefficient of friction than the reading plate. 2. The document conveying device according to claim 1, wherein the document conveying device is surrounded by a surrounding member that opens at least a reading area of the reading plate and covers a position where the reading plate comes into contact with the roll. 3. The document feeder according to claim 2, wherein a portion of the surrounding member that contacts the upstream roll is higher in height than a portion that contacts the downstream roll. 4. When the document transport mechanism is closed, the document transport mechanism is engaged with the document transport mechanism, and the height of the reading plate in the reading area, which is inclined following the inclination of the roll in the axial direction, is kept constant. 4. A latch section comprising:
Document transport device according to any one of the above.