JPS5821767A - Original conveyor - Google Patents

Abstract

PURPOSE:To convey an original with sufficient conveying force and to position the trailing end of the original accurately during backward conveying by forming rugged parts on the top surface of a guiding member and the part of a conveying belt sliding on the guiding member in contacting therewith. CONSTITUTION:When an original passes on a guiding member 10, it is held surely in place by rugged parts 12, 13 and the ruggedness of a conveying belt 30 formed by pressing of a press roller 36 and receives effective conveying force accordingly. There is no need for so much strong pressing force of the roller 36. At the time when the trailing end of the original abuts on the stepped part 11 of the stopper during backward conveying, the trailing end of the original does not ride on the member 10 beyond the part 11 because the projecting parts of the belt 30 enter the recesses 12. Smaller thickness than for the prior art is required for the part 11, and thin originals are conveyed without creasing. Thick originals are surely conveyed as well and the fail-proof positioning of the originals during backward conveying is assured.

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.

Traditionally, a document conveyance device in an electronic copying machine has a paper feed section at one end and a paper ejection section at the other end, and the conveyor belt is placed over the document glass and between the edge of the document glass and the paper feed section. The document is stretched so as to be able to rotate forward and backward in sliding contact with a guide member provided in between, and the document sent from the paper feed section is conveyed from the guide member onto the document glass by rotating the conveyor belt in the forward 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 surface in sliding contact with the conveyor belt is flat, it has the following drawbacks.

■Stretching of the guide member (If the 1q of the stepped part is small, the trailing edge of the document will ride on the guide member when the document is reversely conveyed.
The document cannot be accurately positioned and stopped. This is especially noticeable in the case of thin paper.

0On the other hand, if the guide member's stop edge is thick, 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 be stuck to the stopper step when the document is conveyed in reverse. When it comes into contact with something, it bounces back (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).

Furthermore, in order to press the conveyor belt onto the guide member and onto the document glass, if a presser roller is installed on the back side of the conveyor belt at the exposure section, in other words, on the document glass,
The conveyor belt is squeezed by the stopper stepped portion of the guide member, which shortens the life of the conveyor belt and increases 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 original glass, and the conveyance force becomes unstable and small.

1. 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.

! In order to achieve the above object, 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, and a portion of the conveyor belt that slides on at least the guide member. It is formed with a concave and convex portion that fits into the concave and convex portion on the guide member, so that the pressure force of the conveyor belt can be appropriately set, and the trailing edge of the document can 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 the paper feed section (1) and the guide member 0 (
1, the document glass (a), the transport belt ■ζ paper ejection section (
4α, and a scanning exposure device φ and a photosensitive drum (60) are arranged below the document glass (2III).

In the paper feed section (1), a paper feed path (4) is formed by guide plates +21 and +3+, and this paper feed path (4) includes a document feed detection sensor (5), a stopper claw (6), and an opposing sensor. A 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 document passes, and is turned off when the trailing edge of the document passes. Stopper claw (
6) always enters the paper feed path (4) and locks the leading edge of the inserted document, but a release solenoid (not shown) operates with a certain time delay based on the leading edge detection signal of the sensor (5). ) to rotate clockwise in FIG. 1 and retreat 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). Then, the auxiliary roller (
8) is rotated clockwise in FIG. 1 by turning on a drive solenoid (not shown) after the pinch roller (7) is pressed.

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 based on the rear end detection signal of the sensor (5). .

The guide member +IG connects the edge of the original glass ■ and the paper feed section (11
), and the top surface is the paper feed path (4).
The tip is slightly inclined downward from the end of the stopper (
11). Further, as shown in FIG. 2, there is a recess (12,
A convex portion u3 is formed.

The conveyor belt ω is stretched between the drive roller (111) and the tension roller ■, and is pressed from the back side by the presser rollers
A drive roller (31
) is rotated in the direction of arrow (A) or in the direction of arrow (c) opposite to arrow (c). The tension roller (support) is shown in Figure 3.

As shown in Fig. 4, it is rotatably mounted on a bearing (to) provided in the guide hole @ of the frame so as to be movable laterally, and the disc (to) fixed to the bearing (to) and the frame ( 21)
The right side (
In FIG. 1, it is biased to the left). As shown in FIG. 2, the presser roller frame is fixed to the support shaft (material) so as to face the recess (121) of the guide member (II, and the support shaft is the frame C21). ) is rotatably and vertically movable in the guide hole of the frame.
It is biased downward by a torsion spring wound around □□,
With this biasing force, the presser roller (to) presses the back side of the conveyor belt (2), and the front side is pressed along the guide member (uneven portions 10i +12) and +13) by the belt's own elasticity. On the other hand, another presser roller (38) is also rotatably mounted so as to be vertically movable, and is biased downward by the same structure as the torsion/spring (a).
The front side of the document glass (2Q) is pressed so as to be in sliding contact with the document glass (2Q).

Note that this conveyor belt (to) is connected to the paper feed detection sensor (5).
) in combination with a timer and forward rotation, reverse rotation, and stop, and the operation will be explained in detail later.

The paper discharge section (40) has a paper discharge path (441) formed by guide plates (411, 12), and the end of the guide plate (421) extends from above the conveyor belt 2 to above the paper feed section (1), A discharge tray (431) is configured. Also, a paper discharge path (a document discharge detection sensor f451, a pair of discharge rollers f4)
61, [461 are installed. The paper discharge detection sensor (451 is turned on when the leading edge of the document passes, and is turned off when the trailing edge of the document passes).
(46) is rotationally driven by the front end detection signal of the sensor (451), and its rotation is stopped with a certain time delay by the rear end detection signal of the sensor (451).

On the other hand, the scanning exposure device ω has a well-known configuration consisting of an exposure lamp (511, mirror ◯~kasumi, lens zheng), and a photoreceptor drum that can be driven to rotate in the clockwise direction in FIG. Includes charging charger F611, developing device (support), transfer charger (01, cleaning device (foundation)
Equisensory imaging elements are arranged.

Next, the operation of the document conveying device having the above configuration will be explained with reference to the time chart shown in 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 period (T3) has elapsed since the tip detection signal, the auxiliary roller (8) is driven to rotate and the conveyor belt (to) is driven to rotate forward in the four directions of the arrows. The original is on the roller (7).

It is conveyed to the right during the rotation of (8), and is further clamped between the guide member and the conveyor belt (toward), and the conveyor belt ■
The document is conveyed by the normal rotation of the document glass, and is further conveyed while being clamped between the document glass (■) and the conveyor belt (toward). After the trailing edge of the document is detected by the sensor (5), the forward rotation of the conveyor belt (to) is stopped after a period of time (T4) has elapsed, and each solenoid of the paper feed section +11 is turned off, and the stopper claw ( 6)
enters the paper feed path (4), the pinch roller (7) separates from the auxiliary roller 2 (8), and the rotation of the auxiliary roller (8) is stopped. At this time, the document stops at a position where the trailing edge of the document has been conveyed by (Δt2) from the stopper step part flll of the guide member (II in FIG. Stepped portion (set to exceed 1υ).

Next, after the elapse of time (T5), the transport bell) CI is changed to the time (T5).
The document that is reversely reversed by 6) in the direction opposite to the arrow (A) and conveyed backward to the left in FIG. 1 is positioned at a stopping position with its trailing end coming into contact with the stopper step 01). This time (T6) is set to allow enough time for the trailing edge of the document to be reversely conveyed by (Δt2).1. After the trailing edge of the document comes into contact with the stopper step (11), the conveyor belt begins to slip over the document.

Here, when a copy start signal is input, the photosensitive drum +601 rotates clockwise to start a well-known copying operation, and the scanning exposure device ω moves to the right in FIG. (to) Scanning and exposing the image of the document stopped above onto the photoreceptor drum ω.

When the copying operation is completed, the conveyor belt rotates forward in response to the completion signal, and the document is discharged from the paper discharge path f441 onto the tray (43).At this time, the document leading edge detection signal from the paper discharge detection sensor Ejection roller; 7 (46)
), the drive is stopped. Further, the normal rotation of the conveyor belt (2) is stopped by the rear end detection signal of the sensor (45).

By the way, when two original documents are inserted into the paper feed section (1) while the first original is being copied, when the leading edge of the two original documents is detected by the paper feed 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 (■ detects the leading edge of the first document and is rotated with a time delay (Tx). This is because the document between the first and second sheets overlaps on the document glass ■, resulting in poor conveyance. This is to prevent paper jams from occurring.

However, this time (Tx) delay is set when the length of the two originals is shorter than the length of the first original; If it is shorter than or equal to, it becomes time (TX=O). 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 general feed 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 (Tx). . That is, first, when an attached sensor detects the leading edge of the document, the transport roller is rotated, and at the same time a microcomputer etc. starts counting time, and the count value up to the time when the trailing edge is detected is stored in memory, and the previous document is Compare with the stored value. In addition,
In this case, the document between the two sheets is transferred between the transport roller and the pinch roller (
7), forming a loop.

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

Set the conveyance and ejection speed to (V,), the length of the first document to 4,
The length of the original between two sheets is (I3), the distance from the stopper claw (6) to the stopper step (Illt) is (4), the distance from the stopper (step (11) to the paper discharge detection sensor T4511). (1-), the reverse conveyance distance (Δt2), and the distance from the paper discharge detection sensor to the discharge tray (4■) is (Δt□).

In this case, the time for the first document to be completely ejected after turning on the paper ejection detection sensor (4ω) is (A + Δt1)/■
The time it takes for the second document to move away (Δt2) from the stopper step 01) and stop on the original glass ■ is (B+ by ten Δ).
t )/V1.

Therefore, in the case of A)B, it is sufficient to set (Tx) that satisfies the formula (A+Δ11)/v1-Tx=(B+z+Δt2).

That is, the time (Tx) is Tx=((A+Δt,)-(B+t+Δt2))/v1
It is expressed by the following formula.

In the above first embodiment, the document is guided by the guide member tlO+
When passing over the guide member (101, the uneven portion α2
In addition to the presence of ゜ (13), the unevenness of the conveyor belt (to) formed by the pressure of the presser roller (to) ensures that the document is securely clamped between the conveyor belt (to) and the guide member 0α for effective conveyance. You can get the force from the presser roller (to)
It is not necessary to make the pressing force so strong. Moreover, when the trailing edge of the document comes into contact with the stopper stepped portion αJ during reverse conveyance, the convex portion of the conveyor belt There is no chance of it getting on top of the original glass.
From the concave part (height in 12 mm ←), the height of the convex part 031 h
Even if each is about 1-, the above-mentioned riding will not occur. Therefore, the thickness of the stopper stepped part (11) can be made smaller than that of the conventional one, and as mentioned above, the pressing force by the presser roller (to) can be reduced, and the stopper stepped part α1) has the effect of squeezing the document. Even thin originals 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 (1α), it is possible to reduce the coefficient of friction by coating the upper surface of the guide member (1) with Teflon or by forming it from polyacetal, ultra-high molecular weight polyethylene, etc. In addition, if the stopper step portion αl) 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 it during reverse conveyance.

FIG. 9 shows the main part of the second embodiment, and FIG. 10 shows the main part of the third embodiment. This reliably prevents the trailing edge of the document from bouncing back or running over when the trailing edge of the document comes into contact with the stopper step (11) during reverse conveyance.

FIG. 11 shows a fourth embodiment, in which the driving roller (31) of the conveyor belt circle is connected to the guide member (the uneven portion of 101+IZ,
+13 and a presser roller (to) is provided on the document glass ■.In this case, in order to form uneven portions corresponding to +12 and Q31 on the conveyor belt (to), the steps shown in Fig. 12 are as follows. As shown, a recess (3
0b), and the remaining part is a convex part (0b) corresponding to the concave part 0b).
aOa). Alternatively, as shown in FIG. 13, a convex portion corresponding to the concave portion l may be formed on the surface of the drive roller (31), and an uneven portion may be formed on the surface by the elasticity of the conveyor belt.

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.

As is clear from the above description, the present invention forms an uneven portion extending in the document conveying direction on the upper surface of the guide member, and at least a portion of the conveyor belt that slides on the guide member. Since the uneven portions are formed to fit into the uneven portions, the document can be reliably sandwiched between the conveyor belt and the guide member, and the document can be conveyed with sufficient conveyance force, and the document I can be accurately positioned during reverse conveyance. can do.

[Brief explanation of the drawing]

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 foot. FIG. 6 is a cross-sectional view of the roller, FIG. 6 is a cross-sectional view of the entire roller, 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. 10 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, (101... Guide member, (1
11... Straight step part, (121... Concave part, (1
3...Protrusion, ■...Original glass, (3LI)...
Conveyor belt, (30a)...Protrusion, (30b)...
Recessed portion, cill...drive roller, (to)...presser roller, +401...paper discharge section. Patent applicant Minolta Camera Co., Ltd. Agent
Patent attorney Aoyama Hajime and two others

Claims (1)

[Scope of Claims] l A paper feed section is provided at one end and a paper discharge section is provided at the other end, and a conveyor belt is slid over a document glass and a guide member provided between the edge of the document glass and the paper feed section. The conveyor belt is rotated in the forward direction to convey the document fed from the paper feed unit from above the guide member to the document glass, and then the conveyor belt is reversed to convey the document in the reverse direction. In the document conveying device that stops the document at a position where the trailing edge of the document comes into contact with a stopper stepped portion of the guide member, an uneven portion extending in the document conveyance direction is formed on the upper surface of the guide member, and What is claimed is: 1. A document conveying device characterized in that at least a portion of the guide member that slides thereon is formed with a concave and convex portion that enters into the concave and convex portion of the guide member. 2. The document conveyance device according to claim 1, wherein the upper surface of the guide member is inclined in the document conveyance direction over a leading end thereof. 3. The document conveying device according to claim 1, wherein a concave and convex portion corresponding to the concave and convex portion of the guide member is formed on the entire circumferential surface of the conveying belt.