JPS5821762A - Original conveyor - Google Patents

Abstract

PURPOSE:To obtain a oringal conveyor which permits adequate setting of the press contacting force for a conveying belt, conveys originals with sufficient conveying force without creasing the originals and positions the originals accurately during backward conveying by forming rugged parts extending in the conveying direction of the originals on the top surface of a guiding member. CONSTITUTION:When an original is going to pass on a guiding member 10, effective conveying force is obtained by the rugged parts 12, 13 of the member 10 and the ruggedness of a conveying belt 30 formed when pressed with a press roller 36. Since there is no need for making the pressing force of the roller 36 so much high, the thin original can be conveyed without creasing, and the thick original is conveyed surely. During backward conveying, the original is surely positoned with a stepped part 11 of a stopper.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a document conveying device in an electronic copying machine or the like.

BACKGROUND TECHNOLOGY Conventionally, a document conveyance device in an electronic copying machine has a paper feed section at one end and a paper discharge section at the other end, and a conveyor belt is placed over the document glass and between the edge of the document glass and the paper feed section. The original is placed in sliding contact with a provided guide member so as to be rotatable in forward and reverse directions, and the original fed from the paper feed section is transported from above the guide member onto the original glass by rotating the transport pellet in the normal direction. The conveyor belt is reversed to convey the document in the reverse direction, and the document is stopped at the position where the trailing edge of the document contacts the stopper step of the guide member. After the document image is exposed on the photoreceptor, the conveyor belt is rotated forward again to convey the document. A so-called switchback method is available in which paper is ejected from a paper ejecting section.

However, in this case, since the upper surface of the guide member, that is, the sliding surface with the conveyor belt, is flat,
It has the following drawbacks.

■If the thickness of the stopper stepped portion of the guide member is small, the trailing edge of the document will ride up on the guide member when the document is conveyed in reverse, making it impossible to accurately position and stop the document. This is especially noticeable in the case of thin paper.

On the other hand, if the thickness of the stopper step of the guide member is large, the document may wrinkle when passing through the stopper step (especially in the case of thin paper), or the trailing edge of the document may touch the stopper step during reverse transport. It may bounce back when it comes into contact with the paper (especially if it is made of cardboard),
If the leading edge of the document is curled, the leading edge will rise on the guide member, causing poor copying in any case, including the defect (3).

In addition, in order to press the conveyor belt onto the guide member and the document glass, if the presser roller is installed on the back side of the conveyor pellet and is placed on the exposure area, in other words, on the document glass, the conveyor belt will be guided. The stopper step of the member tightens the belt, shortening the life of the conveyor belt and increasing the driving torque. On the other hand, if there is no press roller in the exposure section, a gap is likely to be formed between the conveyance belt and the document glass, and the conveyance force becomes unstable and small.

The present invention has been made in view of the above-mentioned drawbacks, and its purpose is to transport the original with sufficient transport force without causing wrinkles, and to accurately position the original during reverse transport. The purpose of the present invention is to provide a conveyance device.

SUMMARY In order to achieve the above objects, the document conveying device according to the present invention has an uneven portion extending in the document conveying direction on the upper surface of the guide member, thereby adjusting the pressing force of the conveying belt to an appropriate level. This allows the trailing edge of the document to be accurately positioned during reverse conveyance.

Embodiments FIGS. 1 to 8 show a first embodiment of a document conveying device according to the present invention.
An example is shown and schematically shows a paper feed section (1) and a guide member (
lO), original glass (20), and conveyor belt (8o)
and a paper ejecting section (40), and a document glass (20).
A scanning exposure device (50) and a photoreceptor drum (60) are installed at the bottom of the
) are installed.

In the paper feed section (1), a paper feed path (4) is formed by guide plates +2) and +8), and this paper feed path (4) includes a document feed detection sensor (5) and a stopper claw (6). , an opposing pinch roller (7), and an auxiliary roller (8) are installed.

The paper feed detection sensor (5) is turned on when the leading edge of the original passes, and turned off when the trailing edge of the original passes. The stopper claw (6) always enters the paper feed path (4) and locks the leading edge of the inserted document, but it is released after a certain time delay based on the leading edge detection signal of the sensor (5). Rotates clockwise in Figure 1 by a solenoid (not shown),
Evacuate from the paper feed path (4). Although the pinch roller (7) is always separated from the auxiliary roller (8) to open the paper feed path (4), a pressure solenoid (not shown) operates with a certain time delay based on the tip detection signal of the sensor (5). (1) is pressed against the auxiliary roller (8). After the auxiliary roller (8) is pressed against the pinch roller (7), a drive solenoid (not shown) is turned on, and the auxiliary roller (8) is driven to rotate in the clockwise direction in FIG.

The release solenoid for the stopper claw (6), the pressure solenoid for the pinch roller (7), and the drive solenoid for the auxiliary roller (8) are each turned off with a certain time delay in response to a signal detected from one end of the sensor (5).

The guide member (10) is installed between the end of the document glass (2o) and the paper feed section (11), and its upper surface is slightly inclined downward from the end of the paper feed path (4). The tip is a stopper step (11). In addition, at the tip of the top surface,
As shown in Fig. 2, a recess (
12), a convex portion (13) is formed.

The conveyor heald (30) is stretched between the drive roller (31) and the tension roller (32), and is attached to the presser roller (30).
86) and (88), the drive roller (31), which can be rotated forward and backward while in sliding contact with the front 1 guide member (lO) and the document glass (20), moves in the west direction of the arrow or Rotationally driven in the opposite direction of arrow (A). As shown in FIGS. 3 and 4, the tension roller (32) is rotatably mounted on a bearing (33) provided in the guide hole (22) of the frame (21) so as to be movable laterally. , bearing (33)
It is biased to the right (left in FIG. 1) by a tension coil spring (35) whose both ends are fixed to a disk (34) fixed to the frame (21). Presser roller (37)
is fixed to the support shaft (37) so as to face the recess (12) of the guide member (lO), as shown in FIG.
The support shaft (37) is attached to the backing plate (2) attached to the frame (21).
3) is installed in the guide hole (24) so that it can rotate and move up and down. Also, both ends of the support shaft (37) are attached to the frame (21).
) is wound around a pin (25) protruding from the torsion spring (
26), and this urging force causes the presser roller (36) to press the back side of the conveyor belt (80"l).
(80) Uses its own elasticity to press along the uneven portions (12), (13"l) of the guide member (10). On the other hand, the other presser roller (38) also rotates and moves up and down. The torsion spring (
26) with the same configuration as the conveyor bell)
The front side of (80) is pressed so as to be in sliding contact with the original glass (20).

Note that this conveyor belt (30) is connected to the paper feed detection sensor (
5) Normal rotation in combination with on/off and timer.

Reversing and stopping are controlled as appropriate, and the operations will be explained in detail later.

The paper ejection section (40) has a guide plate (41) (421 forms a paper ejection path (44), and the end of the guide plate (42) is a conveyor belt) (80) from above the paper feed section (1). ) and constitutes a discharge tray (43). Further, a document discharge detection sensor (45) and a pair of discharge rollers (46), (46) are installed in the paper discharge path (44). The discharge detection sensor (45) is turned on when the leading edge of the document passes, and is turned off when the trailing edge of the document passes. Ejection roller (46).

(46) is rotationally driven by the front end detection signal of the sensor (45), and its rotation is stopped with a certain time delay in response to the rear end detection signal of the sensor (45).

On the other hand, the scanning exposure device (50) includes an exposure lamp (51),
The photosensitive drum (60) has a well-known configuration consisting of mirrors (52) to (55) and a lens (56), and is rotatable in the clockwise direction in FIG. ), developing device (62), transfer charger (6:
11), a cleaning device (64), and other well-known image forming elements are arranged.

Next, the document conveying device having the above configuration will be explained with reference to the time chart of FIG.

First, when a document is inserted into the paper feed path (4), its leading edge is once stopped by the stopper claw (6), and after a period of time (T1) has elapsed since the leading edge of the document is detected by the sensor (5). The pinch roller (7) presses against the auxiliary roller (8) to pinch the document, and after a time (T2) has elapsed, the stopper claw (6) retreats from the paper feed path (4). Note that the pressure solenoid of the pinch roller (7) and the release solenoid of the stopper claw (6) both depend on the tip detection signal of the sensor (5), but (T2) -
The time delay (T1) is due to a mechanical delay.

After a time (T3) has elapsed since the tip detection signal, the auxiliary roller (8) is driven to rotate and the conveyor belt (3o) is driven to rotate normally in the direction of the arrow. The original is placed on the rollers (7), (
8), the document is conveyed to the right in FIG. It is sandwiched between the glass (20) and the conveyor belt (3o) and conveyed. After the trailing edge of the document is detected by the sensor (5), the forward rotation of the conveyor belt (30) is stopped after a period of time (T4) has elapsed, and each solenoid in the paper feed section (1) is turned off, and the stopper The claw (6) enters the paper feed path (4), the pinch roller (7) separates from the auxiliary roller (8), and the rotation of the auxiliary roller (8) is stopped. At this time, the document stops at a position where the trailing end thereof has been conveyed (toward Δ) from the stopper step (11) of the guide member (lO) in FIG. That is,
Time (T4) is set to ensure that the trailing edge of the document is securely placed at the stopper step (11
) is set until it is exceeded.

Next, after the time (T5) has elapsed, the conveyance bell (80) is reversed by the time (T6) in the opposite direction to the arrow (A+), and the document being conveyed reversely to the left in FIG. Part (11
) to determine the stopping position. This time (T
6) is set so that the trailing edge of the document is sufficiently reversely conveyed by (Δt2), and the trailing edge of the document is set at the stopper step (11).
After coming into contact with the document, the conveyor belt (3o) will slip on the document.

Here, when a copy start signal is input, the photosensitive drum (60) rotates clockwise to start a well-known copying operation, and the scanning exposure device (50) moves to the right in FIG. At the same time, the image of the document stopped on the document glass (20) is scanned and exposed onto the photoreceptor drum (60).

When the copying operation is completed, it is transported by the completion signal)
(30) rotates normally, and the document is discharged from the paper discharge path (44) onto the tray (43). At this time, the ejection roller (46)
(46) is rotationally driven, and with a certain time delay from the trailing edge detection signal, that is, the trailing edge of the document is moved to the discharge roller (46).
), (46), the drive is stopped. Also, the forward rotation of (80) should be carried out by the sensor (4)
5) It is stopped by the rear end detection signal.

By the way, when a second document is inserted into the paper feed section (1) while the first document is being copied, when the leading edge of the second document is detected by the distributed paper detection sensor (5), , time (T1),
(T2), the pinch roller (7) moves to the auxiliary roller (8).
), and the stopper claw (6) retracts from the paper feed path (4) in the same way as the first sheet, but the auxiliary roller (8) is not immediately driven to rotate, and the paper discharge detection The sensor (45) detects the leading edge of the first document [time (T) after 7
It is rotated with a delay of x). This is to prevent the first and second originals from overlapping on the original glass (20), resulting in poor conveyance and paper jams.

However, this time (Tx) delay is set when the length of the second document is shorter than the length of the first document, and the length of the first document is longer than the length of the second document. If the distance is shorter or equal, it becomes time (T!=0). In this case, the time (Tx) can be made variable depending on the relationship between the lengths of the first document and the second document. As a means for detecting the length of the document, for example, another conveyance roller and a sensor may be attached to the front side of the paper feed section (1) to detect the length of the document and control the time C''IX). .Suhiko, first of all,
When the attached sensor detects the leading edge of the document, the transport roller is rotated and at the same time a microcomputer etc. starts counting the time, and the count value until the trailing edge is detected is stored in memory, and is used as the stored value of the previous document. compare. In this case, the second document becomes a loop between the conveyance roller and the pinch roller (7).

Here, setting of time (Tx) will be explained.

Conveyance and discharge speed (vl), length of one sheet L1 document ^
, the length of the second document is CB), the distance from the stopper claw (6) to the stopper step (11) is (b), and the distance from the stopper step (11) to the discharge detection sensor C45 is ( L
), the reverse conveyance distance (Δt2), and the distance from the discharge detection sensor (45) to the discharge tray (43) as (Δt1).

In this case, the time required for the first document to be completely ejected after turning on the ejection detection sensor (45) is (A+ΔAs)
/ Vl When the second document is placed on the document glass (20), the stopper step (
The time it takes to move away from (Δt2) from (Δt2) and stop is (
B+z+Δt2)/V1.

Therefore, in the case of A)H, [A+Δz1)/v1- Tx= CB+t+Δt2)
What is necessary is to set (Tx) that satisfies the following expression.

In other words, time (Tx) is "x"((A+Δt1)-CB+t+ΔZ2))/
It is expressed by the formula Vl.

In the first embodiment described above, the document is attached to the guide member (10).
When passing over the guide member (lO), the uneven part (1
2) and (18), the presser roller (36
An effective conveying force can be obtained by the unevenness of the conveyor belt (:11O) formed by the compression of the conveyor belt (), and the pressing force of the presser roller (36) does not need to be so strong.

Moreover, when the trailing edge of the original comes into contact with the stopper stepped portion (11) during reverse conveyance, the convex portion of the conveyance bell (80) becomes concave % (11).
2), the trailing edge of the original does not climb over the stopper step (11) and land on the guide member (lO), and the trailing edge of the original does not move from the original glass (20) to the recess (lO).
Even if the height α) to 2) and the height A of the convex portion (13) are each about 111I+, the above-mentioned riding will not occur. Therefore, the stopper step (11)
The thickness of the document can be made smaller than that of the conventional one, and as mentioned above, the pressing force by the presser roller (36) can be reduced, and together with this, the stopper stepped portion (11) does not squeeze the document. Even thin documents can be transported without wrinkles. Even thick originals can be transported reliably, and the stopper stepped portion (11) can reliably position them during reverse transport.

In order to improve the sliding of the original on the guide member (10), the upper surface of the guide member (10) should be made of Teflon-coated material, polyarchital, ultra-high molecular weight polyethylene, etc. to reduce the coefficient of friction. Bye. Also,
If the stopper stepped portion (ll) is thinly covered with an elastic member, it is possible to absorb the impact when the trailing edge of the original comes into contact with a crab during reverse conveyance.

In particular, the guide member (10) has an uneven portion (12), (1B
), but also the conveyor belt) (convex and concave portions corresponding to the convex and concave portions (12) and (13) are formed on the conveyor belt 80'r so that the document can be sandwiched therein). (80''1) and the guide member (10) can reliably sandwich and convey the material.

In this respect, in the conventional apparatus, since this part had no irregularities and was simply flat, the problem of slipping of the original occurred and the pressing force of the conveyor belt was increased more than necessary, which can be overcome.

In addition, as mentioned above, it is possible to obtain sufficient conveying force; on the other hand, the tension roller (32) of the conveying belt (30)
By applying tension in the transport direction to make it movable, and by using the feed-side roller (31) as a drive roller, the drive roller (31) pulls the sheet facing the original glass surface during reverse transport. As a result, the conveying force between the glass and the belt becomes weak, and even if the belt continues to be driven slightly after the trailing edge of the document contacts the stopper step (11) during reverse conveyance, the trailing edge of the document may loop.
It never wrinkles. In this regard, in conventional systems, no consideration was given to creating a difference in the conveying force between conveyance and reverse conveyance, or in other words, to weaken the conveyance force during reverse conveyance. This eliminates the drawbacks of loops and wrinkles that adversely affect copied images. In particular, in the past, tension was applied to the conveyor belt in a direction perpendicular to the conveyor direction, but in this case, the tension only partially acts on the conveyor belt, causing the conveyor belt to meander or correct stretching of the conveyor belt. However, according to the first embodiment, these drawbacks can be overcome by applying tension in the conveying direction (horizontal direction) to the tension roller (32).

Moreover, since the presser rollers (86) and (88) are elastically pressed by the torsion springs (26), the conveyor belt (
The vibrations of 80) are absorbed by the presser rollers (86) and (88), and the conveying force can be stabilized, making it possible to handle thick originals satisfactorily.

Furthermore, as shown in the time chart of Fig. 8, even if the second original is inserted into the paper feed section (1) while the first original is being copied, the rotation of the auxiliary roller (8) will be delayed. That is, by delaying the feeding of the second document onto the document glass (20) by a time (Tx) after the leading edge of the first document is detected by the discharge detection sensor (45), It is possible to completely eject the second document sheet to prevent paper jams, prevent the second document sheet from receiving an excessive reverse conveyance force, and increase the copying speed as a whole. In this regard, in general, in the switchback method, the trailing edge of the document is stopped at a fixed position, so the time required for ejection is constant regardless of the document size, and the time required for insertion depends on the document size. Therefore, if the timing for feeding the second document is set according to the time required for ejection, as in the conventional switch pack method, the conveyance length of the second document will be longer (Δt2).
In other words, the time required for reverse transport varies depending on the document size, and the time required for reverse transport (T6) must be set to the maximum value according to the difference in document size. The paper was subjected to reverse conveyance force, which caused damage to the original. Additionally, if the rotation of the conveyor belt is controlled by a signal from the document feed side, if an A6 size document is fed next to an A3 size document, the A6 size document will be ejected before the A3 size document is ejected. There was a risk that the A3 size document would be conveyed onto the document glass, and that the A3 size document would become jammed at the paper ejection section when the document was conveyed in the opposite direction.

FIG. 9 shows the main part of the second embodiment, and FIG. 10 shows the main part of the third embodiment. It was formed,
This allows the trailing edge of the document to reach the stopper step (11) during reverse transport.
This reliably prevents the trailing edge of the document from bouncing back or riding up when it comes into contact with the document.

FIG. 11 shows a fourth embodiment, in which the drive roller (31) of the conveyor belt (80) is
2) and (13), and a presser roller (86) is provided on the document glass (20), in this case, the conveyor belt (80) corresponds to the uneven portions (12) and (18). As shown in Figure 12, in which the concave and convex portions are formed, a concave portion (80b) corresponding to the convex portion (13) is formed on the front side of the conveyor belt (80) by molding or polishing, and the remaining portion is removed. The portion may be a convex portion (80a) corresponding to the concave portion (12). Or the 13th
As shown in the figure, there is a recess (1) on the surface of the drive roller (31).
Convex portions corresponding to 3) may be formed, and uneven portions may be formed on the surface of the conveyor belt (80) by its own elasticity.

In each of the above embodiments, one conveyor belt (80) is used, but a plurality of conveyor belts (30) are used.
may be arranged in parallel at positions corresponding to the recesses (13).

Further, in each of the embodiments described above, a so-called manual insertion type was shown for inserting the original into the paper feeder (1), but an automatic paper feeder may also be used.

Effects As is clear from the above explanation, the present invention has a concavo-convex portion extending in the document conveyance direction on the upper surface of the guide member.
The original can be transported with sufficient transport force, and the trailing edge of the original can be accurately positioned during reverse transport.

[Brief explanation of drawings]

1 to 8 show a first document conveying device according to the present invention.
1 is a sectional view of the whole, FIG. 2 is a perspective view of the main parts, FIG. 3 is a sectional view of the tension roller, FIG. 4 is a front view thereof, and FIG. 5 is a presser roller. 6 is a sectional view of the entire system, FIG. 7 is a block diagram of the control means, and FIG. 8 is a time chart. FIG. 9 is a sectional view showing the main part of the second embodiment, and FIG. 1θ is a sectional view showing the main part of the third embodiment. FIG. 11 is a sectional view of the entirety of the fourth embodiment, and FIGS. 12 and 13 are perspective views showing modifications thereof. (1)... Paper feed section, (10)... Guide member, (1
1)...stopper step, (12)...recess, (13)
...Convex portion, (2o)...Manuscript glass x, (80)
...Conveyor belt, (86'J...Press, t:o-ra,
(40)...Paper discharge section.

Claims (1)

[Claims] 1. A paper feed section is provided at one end and a paper discharge section is provided at the other end, and the conveyor belt is placed on a document glass and on a guide member provided between the edge of the document glass and the paper feed section. The document is stretched so as to be able to rotate in forward and reverse directions in a sliding contact state, and the document fed from the paper feed section is rotated in the forward direction to convey the document from above the guide member to the document glass, and then the conveyor belt is reversely rotated. A document conveying device that conveys the document in reverse and stops the document at a position where the rear end of the document contacts a stopper stepped portion of a guide member, characterized in that an uneven portion extending in the document conveyance direction is formed on the upper surface of the guide member. Document transport device. 2. The document conveying apparatus according to claim 1, further comprising a suppressing member provided on the back side of the conveying belt to press the conveying plate along the uneven portion of the guide member. 3. The document conveying device according to claim 2, wherein the suppressing member is a pressing roller facing four parts of the guide member. 4. The document conveying device according to claim 2, wherein the suppressing member is a roller that supports one end of the conveying belt.