JPH0555415B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a sheet document skew feed correction device for correcting skew of a sheet document conveyed in a copying machine, and particularly to a correction device that can correct skew according to the amount of skew of a sheet document. Regarding equipment.

Prior Art In a copying machine that performs copying by slit exposure while conveying a sheet original, if the sheet original being conveyed is skewed, the copied image will be tilted, or in worse cases, the copied image will be chipped. A problem like the one mentioned above arises.

Conventionally, in document conveyance devices with a separation mechanism such as ADF conveyance, skew has been prevented by guiding on the side of the tray or cassette, but since sheet document conditions vary widely, skew cannot occur. This was likely to occur and could not be prevented. A method has also been adopted in which the leading edges are brought into alignment by abutting against each other, but this poses a problem in that the leading edge of the document is likely to be damaged by the impact caused by the abutment, and there are restrictions on the types of documents that can be transported.

Conventional correction devices for correcting skew in sheet documents include devices that correct skew in documents by tilting the roller shaft with respect to the conveying direction of the document, and devices shown in Figs. 1 and 2. A guide member 20 for reversing the course of the original on the transport path of the original, as shown in the "sheet skew feed correction device for copying machine" described in Japanese Patent Application Laid-Open No. 57-93848.
There has been a device for correcting skew by automatically tilting the guide member 201 according to a skew detection signal of a document.

However, the former method has the disadvantage that the amount of correction changes when the roller wears or slips occur on the roller surface, making it impossible to perform proper correction. In the latter case, since a reversing section must be placed in the middle of the document conveyance path, the conveyance path becomes long, resulting in severe layout constraints.

The amount of skew of a sheet document varies depending on various factors such as the initial paper feeding condition, the size and material of the sheet document, but adjusting the amount of correction according to the size of the skew amount is the same as the conventional skew Depending on the correction device, it is technically very difficult to perform satisfactory skew correction due to restrictions in arrangement and document conditions.

Purpose This invention was devised to solve the above-mentioned problems with the conventional sheet document skew feed correction device for copying machines. It is an object of the present invention to provide a sheet document skew feeding correction device that can perform appropriate skew correction depending on the magnitude of the skew amount of a sheet document by using a mechanism.

Configuration The present invention will be described below based on embodiments shown in the drawings.

First, the skew correction mechanism used in this invention, which is novel in itself, will be explained.
In the figure, a support rod 51 is installed approximately in the center of a beam-shaped support member 52 stretched between a pair of side plates 71 that is fixed to the main body of the copying machine, and a bearing 54 is attached to this support rod 51. Almost the center of the holding member 53 is rotatably supported through the holding member 53.
Arc-shaped inner and outer guide plates 56 and 57 are attached at a predetermined interval to form a conveyance path 59 by a bracket 58 on the document conveyance path side, and the holding member 53 is attached to the support rod 51. Te color 5
5 for positioning in the thrust direction.

Near both ends of the support member 52 and away from the back surface of the holding member 53, two sets of support members each consisting of a pair of front and rear brackets 62, 62' are attached at symmetrical positions on both sides of the support rod 51. is,
A pressing member 63 is slidably fitted into the through holes provided in the brackets 62, 62'.
A compression spring 65 is interposed between the flange 64 attached to the inner side of the bracket 62 and the inner surface of the bracket 62'.
The head of the holding member 53 is always pressed against the back surface of the holding member 53, and the holding member 53 is held at equal positions on the left and right sides with respect to the support rod 51 unless an external force is applied.

A pair of solenoids 67 and 68 are installed via brackets 72 at substantially symmetrical positions on both sides of the support rod 51 of the support member 52, and the operating rods of these solenoids are connected to arms 66 attached to the holding member 53. connected, each solenoid 6
As the operating rods 67' and 68' of 7 and 68 protrude,
The holding member 53 is rotated about the support rod 51.

Next, based on FIGS. 6 to 8, the guide plate 56
To explain the structure of the guide plates 56 and 57 in more detail, the curved conveyance path 59 formed between the guide plates 56 and 57 is connected to a guide plate 8 fixed within the copying machine main body.
Conveyance path 82 between 0 and 81 and guide plates 83 and 8
The sheet document A, which has been conveyed within the conveyance path 82 by a pair of conveyance rollers, is always fed to the conveyance path 85 through the conveyance path 59. ing.

The conveying path 59 is positioned slightly below the conveying paths 82 and 85 (FIG. 6) when it is in an equilibrium state (standby position) due to the pressing member 63. The fed sheet document A passes through the conveyance path 59 while curving downward. Next, when the holding member 53 is rotated around the support rod 51 by the operation of one of the solenoids 67 and 68, one side of the conveyance path 59 is raised from the standby position with respect to the support rod 51 (the seventh
(Fig. 8) and the other side is lowered (Fig. 8). At this time, the portion of the conveyance path 59 on the raised side is the seventh
As can be seen from the figure, the conveyance paths 82 and 85 are connected in a straight line, and as a result, the portion of the sheet document A that passes through this position passes through the conveyance path 59 in the shortest distance. . Furthermore, as can be seen from FIG. 8, the portion of the conveyance path 59 on the lowered side is
The sheet document A is further curved downward, and as a result, the portion of the sheet document A that passes through this position passes through the transport path 59 over a longer distance than when it is in the standby position (FIG. 6). Become. Therefore, either one of the solenoids 67, 68 is activated,
The sheet document A that passes through the conveyance path 59 with the holding member 53 rotated has a different conveyance distance on both sides thereof.

The skew correction device according to the present invention is constructed by arranging a plurality of the above-mentioned skew correction mechanisms (four in the drawing) in series in the middle of the conveyance path of the sheet document A, as shown in FIG. be.

In FIG. 9, each skew correction mechanism 23d, 2 is arranged in order along the conveyance direction of a sheet document.
3c, 23b, 23a are respective pairs of solenoids 67d, 68d, 67c, 68c, 67
b, 68b, 67a, and 68a are arranged so that the distance between the solenoids in each pair increases from the front side to the rear side in the sheet document conveyance direction. 53a, 53b, 53c, 53
The amount of inclination of d is the largest at the skew correction mechanism 23d, and becomes smaller toward the rear.

Next, each of the above-mentioned skew correction mechanisms 23a, 23b,
The skew detection section and the control section for selectively operating the skew correction mechanisms 23c and 23d will be explained. A pair of skew sensors 31, 3 are arranged in a direction perpendicular to the document conveyance direction, as shown in FIG. 10, at the front side in the conveyance direction.
2, the amount of skew of the document is detected. FIG. 11 shows an example of a control circuit for controlling the skew correction section 23, in which each skew sensor 31, 32 has a light emitting diode 31a, 32a and a phototransistor 31b, 3
2b, light emitting diodes 31a, 32
When the light emitted from a is reflected by the document, the phototransistors 31b and 32b are turned on, and H level signals are output from the comparators 161 and 162, which are sent to the microcomputer via the amplifiers 171 and 172. 180 input port.

The microcomputer 180 has a built-in clock pulse generator (not shown) and first and second counters. When the skew sensor 31 first detects a document, the first counter operates and the clock pulse generator outputs an output. The number of clock pulses is counted, and when the skew sensor 32 detects a document, the counting is stopped. Conversely, when the skew sensor 32 detects the document first, the second
A counter operates to count the number of clock pulses, and stops counting when the skew sensor 31 detects a document.

The microcomputer 180 is preset with first to fourth set numbers, which are divided into predetermined ranges, starting from the smallest number of clock pulses. When the skew sensor 31 detects the document for the first time, the count number of the first counter is compared with each of the preset numbers, and if the count number is within the range of the first set number, the output is A drive signal is output from port p-1a, and when it is within the range of the second set number, from p-1b, when it is within the range of the third set number, from p-1c, and when it is within the range of the fourth set number. At this time, the drive signal is output from p-1d.

On the other hand, when the skew sensor 32 detects a document for the first time, the count number of the second counter is compared with each of the preset numbers, and if the count number is within the range of the first set number, the output port p-2a is Outputs a drive signal from p-2b when it is within the range of the second set number, and from p when it is within the range of the third set number.
-2c, if within the range of the fourth setting number, p-2
A drive signal is output from d.

And each output port p-1a, p-2a, p-1b, p-2b of the microcomputer 180,
p-1c, p-2c, p-1d, p-2d are respective skew correction mechanisms 23a, 23b, 23
c, 23d solenoids 67a, 68a, 67
b, 68b, 67c, 68c, 67d, and 68d in order, and each output port p-1a to p-2
Each of the solenoids 67a to 68d is driven by a drive signal output from the solenoid 67a to 68d.

Next, the operation of the embodiment constructed as described above will be explained.

When the original A is skewed and conveyed as shown in FIG.
input to input port-2. Then, in the microcomputer 180, a built-in second counter counts the number of clock pulses output from a built-in clock pulse generator (not shown) (t ₁ in FIG. 12). When the skew sensor 31 detects the document A after being conveyed, the count stops (t ₂ in FIG. 12), and the count number of the second counter is compared with each of the preset numbers, and the count number is determined. If it is within the range of the first set number, a drive signal is output from the output port p-2a, the solenoid 68a is activated, and the skew correction mechanism 23a is moved clockwise with the support rod 51a as the fulcrum, as shown in FIG. angle α ₁
tilt only. Similarly, if the count is within the second set number, a drive signal is output from the output port p-2b, the solenoid 68b is activated, and the skew correction mechanism 23b is moved by the angle α ₂ (α ₁ <α ₂ ). When the skew correction mechanism 23c is within the range of the third set number, and the skew correction mechanism 23d is tilted within the range of the fourth set number, the angles α ₃ and α ₄ (α ₁
< α ₂ < α ₃ < α ₄ ).

Therefore, if the skew amount of the sheet document A corresponding to each set number of the second counter is set equal to the skew correction amount of each of the skew correction mechanisms 23a, 23b, 23c, and 23d, One of the skew correction mechanisms corresponding to the amount of skew is operated, so that appropriate skew correction can be performed.

When the document A is skewed and conveyed in the opposite direction as shown in the figure, the skew sensor 31 first detects the document (t ₃ in FIG. 12), and the comparator 161 outputs an H level signal, causing the microcomputer 180 to Input to input port-1. The built-in first counter of the microcomputer 180 then counts the number of clock pulses in the same manner as described above until the skew sensor 32 detects the original A (t ₄ in FIG. 12). If the counted number is within the range of the first set number, a drive signal is output from the output port p-1a, and the solenoid 6 is
7a, the skew correction mechanism 23a is moved counterclockwise in FIG _.
Similarly, when the number is within the second set number, the skew correction mechanism 23b is tilted, when the number is within the third set number, the skew correction mechanism 23c is tilted, and the fourth set number is tilted.
When the number is within the set number, the skew correction mechanism 23d
in the counterclockwise direction in Fig. 13 at angles α ₂ , α ₃ ,
Rotate by α ₄ (α ₁ < α ₂ < α ₃ < α ₄ ). Therefore, as described above, appropriate skew correction can be performed depending on the amount of skew of the document.

FIGS. 14 and 15 show an example in which the sheet document skew feed correcting device is installed in a circulating document conveyance unit. In a circulating document transport unit installed in such a copying machine that makes multiple copies of a single original, the same original is circulated through the same document transport path many times, so it may not be straight at first. The skew in the manuscript gradually increases. For this reason, it becomes necessary to install the skew feed correction device within the circulation conveyance path of the document.

First, the circulation type document transport unit 131 will be explained.
The originals sent into the paper feeder 3 collide with a barrier 134 installed perpendicularly to the rising conveyance unit 133, and the insertion of the originals is detected by a sensor 135, and the originals are brought into contact with each other by the operation of a solenoid 136. It is held between a pair of friction rollers 137 and 138 which are separable and held in a skew-free state.

Next, the delayed output from the solenoid 136 activates the solenoid 139 to remove the barrier 134 from the conveying path, and the roller 138 begins to rotate to begin conveying the document. At this time,
Various information such as the document size and feeding direction can be obtained from the time it takes the document to pass through the sensor 135, and based on this information, the transfer paper selected based on the copying magnification etc. is synchronized with the conveyance of the document. The paper is fed from a paper feed tray (not shown).

After the document is conveyed to the slit exposure section 141 by the conveyance roller 140 and exposed and read,
After the document is circulated in a conveyance loop formed by a curved guide plate 142 and a claw 143 and exposed repeatedly, and a predetermined number of copies are repeatedly copied, the document is released from the conveyance loop and discharged onto a paper output table 148. be done.

Skew correction mechanisms 23a, 23b, 23c, and 23d similar to those in the embodiment described above are arranged between the respective transport rollers 140, and a pair of skew sensors 149 installed in front of the slit exposure section 141 detect the skew of the original. The skew correction mechanisms 23a, 23b, 23c, 2
3d is selectively controlled to perform skew correction according to the amount of skew of the sheet original.

In a copying machine having a conveyance loop as described above, the skew gradually increases while circulation is repeated within the conveyance loop, but the skew correction mechanism is disposed within the conveyance loop as described above. Therefore, appropriate skew correction can be performed each time, and the occurrence of copy errors can be effectively prevented.

16 and 17 show that in the above and above embodiments, each skew correction mechanism is provided with a pair of solenoids 67 and 68, but in addition to this pair of solenoids 67 and 68, another pair of solenoids 69 is provided. , 70, and these two pairs of solenoids 67, 68, 69, and 70 are selectively activated, and the skew sensor is also configured to operate the solenoids 69, 70 in addition to the pair of sensors 31, 32. This shows another embodiment in which a pair of sensors 33, 34 for performing this purpose are arranged corresponding to solenoids 69, 70.

By arranging two pairs of solenoids for each skew correction mechanism in this way,
This can widen the range of selections for adjusting the amount of skew correction, and as shown in FIG. Detected with 34,
Solenoid 67, 68 or 6 corresponding to each
By selectively operating 9 and 70, fine skew correction can be performed according to the paper size.

Note that the number of solenoids disposed in the skew correction mechanism is not limited to one or two pairs, and it goes without saying that the solenoid may be disposed in accordance with the usage range of the copying machine.

Effects As described above, the sheet document skew feed correcting device according to the present invention (1) is configured without a structure that drives the sheet document conveyance, and therefore can be used in any straight portion of the conveyance path. They can be placed in any number of locations, greatly increasing the degree of freedom in layout. It is small and can correct the skew of a wide variety of sheet originals; (3) Since the skew is detected on the original supply side and the skew is corrected, the sheet original can be held in an appropriate state during copying; (4) Since skew correction is possible using the central reference transport method, there are very few restrictions on the range and types of sheet document sizes that can be corrected, and (5) the unit is configured without a transport drive unit. Because of this, it is easy to attach and detach from the copying machine, and it is very easy to change the design and control conditions.Furthermore, among the multiple skew correction mechanisms arranged in series on the conveyance path, it is easy to attach and detach from the copying machine. By selecting and operating a skew correction mechanism having a corresponding amount of skew correction, the present invention has an excellent effect in that skew correction can be performed in accordance with the amount of skew of a sheet document.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of conventional orthodontic devices;
Figures 6 to 5 are configuration diagrams showing one embodiment of the skew correction mechanism used in the present invention, Figures 6 to 8 are explanatory diagrams of correction using a guide plate, and Figure 9 is a layout diagram showing one embodiment of the present invention. , Fig. 10 is a layout diagram showing the detection member in the same embodiment, Fig. 11 is a control circuit diagram of the skew correction section, Fig. 12 is a time chart of the control circuit, and Fig. 13 is an explanation showing the tilting of the skew correction mechanism. 14 and 15 are schematic compositions showing other embodiments of the present invention, and FIGS. 16 and 17.
The figure is a configuration diagram showing still another embodiment of the present invention. 23a to 23d... Skew correction mechanism, 31, 3
2, 33, 34... Skew sensor, 53a to 53
d... Holding member, 56... Inner guide plate, 57... Outer guide plate, 59... Conveyance path, 67a to 67d, 68
a~68d, 69, 70...Solenoid, 180...
microcomputer.

Claims (1)

[Claims] 1. A plurality of sheet document skew correction mechanisms having different skew correction amounts are arranged in series along the conveyance direction of the sheet document conveyance path of a copying machine, and the sheet document skew correction mechanism is arranged in series along the conveyance direction of the sheet document conveyance path of the copying machine. A detection member is arranged to detect the amount of skew of an incoming sheet document, and a control member operates a skew correction mechanism in response to the detected amount of skew based on a detection signal from the detection member. A sheet document skew feed correction device for a copying machine, in which a skew correction mechanism is rotatable in a plane perpendicular to a sheet document conveyance path and orthogonal to a sheet document conveyance direction; a pair of curved guide plates fixed to the holding member to form a curved conveyance path constituting a part of the sheet document conveyance path; and a drive member connected to the holding member to swing the holding member. and when the holding member is in the neutral position, the passage distance of the sheet original is equal for the entire range in the width direction of the sheet original conveyance path between the curved guide plates, and the sheet original cannot be rotated in either direction from this neutral position. Then, the passage distance of the sheet document on the conveyance path is such that one side of the conveyance path is longer than the other side, and the detection member is located on both sides of the sheet document conveyance path in the conveyance direction. When the control member receives a detection signal from the skew detection sensor, it detects the skew amount of the sheet document and controls the skew correction mechanism. 1. A sheet document skew feed correcting device for a copying machine, characterized in that the holding member is oscillated by driving a driving member of the copying machine.