JPH03186559A - Sheet transporting device - Google Patents

Abstract

PURPOSE:To eliminate the unreasonable curvature of a sheet and reduce the transport resistance of the sheet and the variation quantity to realize high precision by forming a curved surface which is curved in the gravity direction in the extension line direction in the sheet discharge direction of a sheet transport means, on a guide member. CONSTITUTION:As recording proceeds, the top edge of a sheet S is suspended by the own weight, and a certain part of the undersurface of the sheet is in contact with a guide plate 63. Since the curvature of the guide plate 63 is set smaller than the curvature in the vicinity of the top edge of the sheet S, the undersurface part in a certain length from the top edge of the sheet S does not contact the guide plate 63. Accordingly, even in the contact between the sheet S and the guide plate 63, the top edge of the sheet S contacts the guide plate 63 free from the collision with the guide plate 63, and the generation of impact can be suppressed to the min., and the variation of the sheet transport speed is reduced, and the uniform pitch of scanning line can be obtained, and the superior image quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sheet conveyance device used for conveying a sheet of photosensitive film or the like in, for example, a medical image recording device or an image reading device.

[Prior Art] In FIG. 1O, S denotes a stack of unused recording sheets, which are stored in a supply magazine 1 arranged approximately horizontally. A suction cup 2 supported by a mechanism (not shown) is provided near the right end of the sheet S. The suction cup 2 is movable into and out of the supply magazine 1 by a support mechanism, enters the supply magazine 1, suctions the uppermost stacked sheet S, moves to the upper right, and transfers the suctioned sheet S to the transport roller. Insert into pair 3. The transport roller pair 3 is rotationally driven by a drive source (not shown), and the sheet S
is transported into a transport path formed by guide plates 4a and 4b. A conveying roller pair 5 similar to the conveying roller pair 3 is provided on the exit side of the guide plates 4a, 4b, and the sheet S fed between the guide plates 4a, 4b is further transferred to the guide plates 6a, 6b.
It is conveyed to the conveyance path formed by. When the rear end of the sheet S separates from the pair of transport rollers 5, the sheet S falls due to its own weight, is guided by the guide plates 6a and 6b, and reaches the pair of transport rollers 7. After that, the pair of conveying rollers 7 rotates in the reverse direction to move the sheet S backward upward, corrects the position of the sheet S, and then rotates forward again to move the sheet S into the conveying path formed by the guide plates 8a and 8b. and sends the leading end of the sheet S to a pair of sub-scanning rollers 9.10. An optical unit 11 is arranged substantially horizontally below the supply magazine l, and a laser beam C emitted from a laser light source (not shown) in the optical unit 11 is directed to a sheet sandwiched between a pair of sub-scanning rollers 9 and 10. A predetermined image is formed on the sheet S by irradiating the sheet S and scanning the sheet S in a direction substantially perpendicular to the conveyance direction of the sheet S. The sheet S on which recording has been completed is transported by a transport roller pair 13.15 through a transport path formed by a guide plate 12, a transport roller pair 13, guide plates 14a and 14b, a transport roller pair 15, and guide plates 16a and 16b. , and sent to an automatic developing machine 17.

[Problems to be Solved by the Invention] However, the above-mentioned conventional example has the following three drawbacks. First, the leading edge of the sheet S discharged from the sub-scanning roller pair 01 during recording hits the guide plate 12, and the impact generated at that time disturbs the conveyance speed of the sheet S, causing the pitch of the scanning line to change. There is a risk that the image quality will deteriorate due to non-uniformity.

Second, even after the leading end of the sheet S contacts the guide plate 12, the leading end of the sheet S continues to be conveyed while constantly abutting against the guide 12ii12. For this reason, the leading edge of the sheet S may get caught in scratches or the like on the guide plate 12, and there is a risk that the image quality will deteriorate, similar to the first drawback described above. It is also conceivable that air is difficult to enter between the sheet S and the guide plate 12, and the two come into close contact with each other, increasing the conveyance resistance of the sheet S, and similarly deteriorating the image quality.

Thirdly, the shape of the sheet S during recording is such that it resists deformation due to its own weight, and there is a drawback that the conveyance resistance of the sheet S is large. For example, when the center portion of a horizontally placed sheet S is held between two rollers and lifted, the leading and trailing ends of the sheet S naturally sag due to their own weight. The posture at this time is considered to be a natural posture in which no strain is placed on the seat S. On the other hand, in the conventional example described above, the sheet S is conveyed in a posture contrary to its own weight acting on the sheet S and the elasticity of the sheet S. Therefore, it is expected that the conveyance resistance of the sheet S will be large and its fluctuations will also be large, and there is a great possibility that image quality will deteriorate due to disturbances in the conveyance speed.

An object of the present invention is to eliminate the above-mentioned drawbacks, and to reduce the conveyance resistance by supporting the posture of the sheet being conveyed in the sub-scanning direction while recording or reading by a guide member having a curved surface curved in the direction of gravity. do.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the sheet conveying device according to the present invention includes a sheet conveying means disposed near a position where recording or reading is performed, and a sheet conveying means disposed near a position where recording or reading is performed, and and a guide member for guiding a recorded or read sheet, wherein the guide member has a curved surface that curves in the direction of gravity in an extension line of the sheet discharge direction of the sheet transport means. It is something to do.

"Under Construction" The sheet conveyance device having the above-described configuration directs the posture of the sheet being conveyed using a guide member having a curved surface that curves in the direction of gravity, thereby reducing conveyance resistance.

[Example] Hereinafter, an example in which the present invention is applied to an image recording apparatus that records an image by scanning a photosensitive sheet with a light beam will be described in detail with reference to FIGS. 1 to 9.

FIG. 1 is a configuration diagram of an embodiment of the present invention. A laser optical unit 50 disposed above includes a laser light source, a light modulator, a polygon mirror, etc., and a laser beam modulated according to an image signal. The beam flood is deflected in the main scanning direction using the rotation of a polygon mirror, and the sheet S at the recording position is
Light scans the photosensitive surface of the Note that while the sheet S is being fed, a shutter (not shown) or the like is used to prevent the laser beam β from being irradiated onto the recording position. Laser optical unit 5
Is there one pair of sub-scanning rollers located below 0?
A pair of rollers is driven by the sieve transfer bar and the sieve roller, and the sheet S held between the two rollers is conveyed at a constant speed to perform sub-scanning for image recording. Note that the laser beam C from the laser optical unit 5o is designed to be main-scanned in the vicinity of the sub-scanning roller pair 2. Below the pair of sub-scanning rollers 51, a supply magazine 52 that stores unrecorded sheets S stacked from below and a receive magazine 53 that stores recorded sheets S are arranged vertically in parallel. Slide lids 52a and 53a that can be opened and closed for loading and unloading sheets S are provided on the upper surface of the magazines 52 and 53, respectively.
, 53a are closed, the interior of the magazine 52, 53 is shielded from light from the outside. Note that the film emulsion surfaces of the sheets S laminated inside the magazines 52 and 53 both face downward, further enhancing the light-shielding effect.

Further, in the opening of the supply magazine 52, a suction cup 54 that sucks the uppermost sheet S of the supply magazine 52 by a suction operation is located at a position E with respect to the supply magazine 52.
It is provided so that it can freely move forward and backward between F. In order to convey the taken out sheet S, three pairs of conveying rollers 55, 56, 57 are provided in the exit direction of the supply magazine 52.
Each of these rollers includes drive rollers 55a, 56a, and 57a, and driven rollers 55b, 56b, and 57b that do not have rotational driving force. These three drive rollers 55a, 56a,
57a is driven by one motor (not shown) via a chain, and drive rollers 55a, 56a, 57a
The number of teeth on each sprocket is determined so that all peripheral speeds are the same. Note that the first driven roller 55
b is movable between positions G and H, and in position H is urged and abuts against the first drive roller 55a. The second driven roller 56b similarly reciprocates between positions J, and at position J it contacts the second driving roller 56a and rotates as a result. Further, the third driven roller 57b is located at positions P, Q, R,
It can move between positions P, Q, and R in a planetary manner while contacting the third drive roller 57a, and at position S it retreats from the third drive roller 57a. Furthermore, a first conveyance roller pair 55 and a second conveyance roller pair 56
A pair of nipping rollers 58 consisting of two rollers without driving force is provided on the conveyance path between the two. This pinching roller pair 58 pinches the sheet S, and resists the force of the sheet S trying to come off from the pinching roller pair 58 due to its own weight, and holds the sheet S by a weak frictional force to prevent it from falling. ing.

In order to correct and align the inclination of the sheet S held between the nipping roller pair 58, a resist plate 59 is provided below the 21st!9th feed roller pair 56, and this resist plate 59 rotates around the rotating shaft 59a. As shown by the east line in FIG. 1 and the solid line in FIG. The resist surface 59b is pressed against the end of the held sheet S to perform a so-called resist operation in which the sheets S are aligned. The back surface of the resist plate 59 is a smoothly processed guide surface 59c, and when the resist plate 59 is in the position shown in FIG.
can slide with almost no friction.

In addition to the above, a sheet guide plate 6° is provided on the conveyance path between the second conveyance roller pair 56 and the third conveyance roller pair 57, and the sheet guide plate 6° is provided on the conveyance path from the third conveyance roller pair 57 to the sub-scanning roller pair 51. , a guide roller 61 is provided, and a movable guide plate 62 is attached so as to be movable up and down between positions (2) and (W), so that the sheet S placed thereon does not come into contact with the third drive roller 57a at position W. has been done. Further, a sheet guide plate 63 is provided behind the sub-scanning roller pair 51.

Note that the sheet S taken out from the supply magazine 52
Even when the leading end of the sheet S reaches the pair of sub-scanning rollers 51, the respective members are arranged at such distances that the trailing end of the sheet S is still held between the pair of first conveying rollers 55.

In the following description, the path along which the sheet S taken out from the supply magazine 52 is fed to the guide plate 63 will be referred to as the first conveyance path, and the guide surface 59c of the resist wafer 59 located at the position
The path from the lower end to the guide plate 611 will be referred to as a second conveyance path. In the first conveyance path, the sheet s is pulled out from the supply magazine 52 and directly goes to the sub-scanning roller χ51, and in the second conveyance path, the sheet S once ejected is transferred to the first conveyance path. A passage through which an internal force is applied to the sub-scanning roller 51 for recording again after passing through the reverse direction,
These conveyance paths share a path from the position J of the second driven roller 56b to the guide plate 63.

Next, to explain the operation of this image recording apparatus, the supply magazine 52 in which unrecorded sheets S are stacked and stored is installed at a predetermined position in the apparatus main body, and the inside of the apparatus is shielded from light with a sliding lid. 52a is opened. The suction cup 54 is operated to lift the topmost sheet S stacked in the supply magazine 52 to position F. Next, the first driven roller 55b, which is initially at position G, is moved to position H, and the leading edge of the sheet S is moved to the first conveying roller pair 55.
sandwiched between. Here, when the first drive roller 55a is rotated clockwise, the sheet S is moved in the direction A and inserted into the nipping roller pair 58. After insertion, when the leading edge of the sheet S moves to a predetermined position, the first driving roller 55
When the first driven roller 55b is stopped and the first driven roller 55b is retracted to position G, the sheet S becomes unrestrained, but is held by the weak frictional force of the pair of pinching rollers 58 and prevented from falling.

When the resist plate 59 is moved to this position in this state, the resist surface 59b presses against the leading edge of the sheet S, and pushes the sheet S back in the direction B against the weak frictional force of the nipping roller pair 58. At this time, the leading edge of the sheet S follows the resist surface 59b, and the inclination of the sheet S is corrected and the position is aligned. After the above resist operation is completed, the resist plate 59
is returned to the initial position M, the first driven roller 55b is moved to position H again, and the first driving roller 55a is driven until the sheet S passes over the second driven roller 56b initially located at position K. , feeds the sheet S in direction A. Here, when the second driven roller 56b is moved from position K to J, the leading edge of the sheet S is held between it and the second driving roller 56a, and the driving rollers 55a and 56a are rotated, the sheet S is moved to the first position.
is conveyed in the direction C along the conveyance path.

Next, when the leading edge of the sheet S reaches the third conveyance roller pair 57, the third driven roller 57b, which is initially at the position Q,
While holding the leading edge of the sheet S, the third driving roller 57a rotates, and the sheet S rotates clockwise planetarily around the third driving roller 57a, and moves to position R. Here, when the revolution of the third driven roller 57b is stopped at position R and the third drive roller 57a continues to rotate, the sheet S is conveyed to the right and inserted into the sub-scanning roller pair 51. Continue transporting as it is,
When the sheet S is conveyed until the rear end of the sheet S is removed from the nipping roller pair 58, the resist plate 5 is moved as shown in FIG.
9 to the position again, and further reverse the sub-scanning roller pair 51 and the drive rollers 55a, 56a, 57a counterclockwise, Z-1 + q 1;
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The rear end of the sheet S continues to move backward, descending in the direction along the guide surface 59c of the resist plate 59, and when the leading edge of the sheet S is removed from the sub-scanning roller pair 51, the second driven roller 56b is evacuated to position K. At this time, the sheet S is held between the third pair of conveyance rollers 57, so when the drive rollers 55a, 56a, and 57a are rotated normally again, the sheet S is conveyed in the direction C along the second conveyance path. Become.

When the sheet S continues to be conveyed in the direction C, the leading edge of the sheet S reaches the pair of sub-scanning rollers 51 rotating in the forward direction again, and at the point when the leading edge is sandwiched between the pair of rollers 51, the third driven roller 57b At the same time, the third drive roller 57a stops and the movable guide plate 62 moves to the position W. At this time, the sheet S is placed on the movable guide plate 62, and is moved by the sub-scanning roller pair 51 while the film emulsion surface is in contact with the guide roller 61, so that the sheet S is sub-scanned.

In this way, the shutter or the like is opened for sub-scanning of the sheet S, and main scanning of the laser beam 2 is started on the sheet S, and a latent image is recorded on the emulsion surface on the upper surface of the sheet S.

The sheet S that is sub-scanned along the second conveyance path is curved along the outer periphery of the movable guide plate 62, but the curve in this part is caused by the repulsive force of the bending of the flexible sheet s and the bending force of the sheet s. It is best to create a curve that approximates the natural state in which the forces that sag due to their own weight cancel each other out. Furthermore, if the sheet s is kept in a natural state without being curved in other parts of the second conveyance path, the frictional resistance between the sheet S and each roller and each guide plate can be reduced. In this way, if the second conveyance path with less frictional resistance is used during sub-scanning, the sheet S to be carried out and the other laminated sheets S left in the supply magazine 52, which occur in the first conveyance path, can be avoided. Frictional resistance caused by static electricity etc. can be prevented. Furthermore, if a straight, uncurved second transport path is selected compared to the first transport path, which has a small radius of curvature of the film transport path, the effect of reducing transport resistance will be further increased. In this way, in this embodiment, it is possible to perform sub-scanning at a stable feed speed with little variation, and it is possible to record a high-quality image on the sheet S without uneven feed.

Note that when image recording is completed as described above, the sub-scanning roller pair 51 is reversed to convey the recorded sheet S on the sheet guide plate 63 in a direction opposite to the sub-scanning direction during recording. When the rear end of the sheet S reaches the third driving roller 57a again, the movable guide plate 62 returns to position V, and the retracted third driven roller 57b returns to position R to nip the sheet S. Next, the third driven roller 57b moves the sheet S
As the third drive roller 57a rotates in reverse with the third drive roller 57a sandwiching the
It rotates around the drive roller 57a counterclockwise, passes through position Q, and moves to P.

Here, when the revolution of the third driven roller 57b is stopped at position P and the third drive roller 57a continues to rotate, the recorded sheet S is conveyed and fed into the receive magazine 53 according to the rotation. When the conveyance into the receive magazine 53 is completed, the third driven roller 57b returns to the initial position Q.

Note that here, the number of sheets S already stored in the receive magazine 53 is detected by means not shown,
If the height of the laminated sheet S in the receive magazine 53 is estimated based on the number of sheets, and the stopping position P of the third driven roller 57b is determined according to this height, it is possible to The recorded sheet S can be fed into the receive magazine 53 without malfunction. Also, sheet S
While feeding the sheet S into the receive magazine 53, the third driven roller 57b is gradually moved from the position P in the Q direction, and the angle at which the sheet S enters the receive magazine 53 is controlled to be gradually increased. is also possible.

Furthermore, by changing the stopping position of the third driven roller 57b and changing the conveyance direction of the recorded sheet S, the sheet S is not stored in the receive magazine 53, but is placed outside the image recording apparatus, for example. It may also be fed directly to an automatic developing device or the like. That is, after the recording on the sheet S is completed, the third driven roller 57b is fixed at the position R so that the conveyance direction of the sheet s moves straight to the left. By continuing to rotate the drive roller 57a counterclockwise, the recorded sheet S can advance along the guide plate and be fed from the discharge port to the automatic developing device directly connected to the side surface.

Next, as shown in FIGS. 3 to 6, the sub-scanning roller pair 5 during recording is
The movement of the sheet S discharged from the sheet S will be described in more detail. FIG. 3 shows a state in which the third driven roller 57b is at position S, the movable guide plate 62 is at position W, the sheet S is held between only the pair of sub-scanning rollers 51, and recording has just started. At this time, the guide plate 6 is placed downward from the tip of the sheet S.
3 exists, the tip of the sheet S is floating in the air.

FIG. 4 shows a state where recording has further progressed, and the contact point between the guide roller 61 and the sheet S is below the line connecting the contact point between the movable guide plate 62 and the sheet S and the contact point between the sub-scanning roller pair 51. Therefore, in this portion, the sheet S has a substantially S-shape due to the balance between its own weight and elastic force. Therefore, the sheet S is discharged slightly upward by the sub-scanning roller pair 51t, so that even when the sheet S is discharged to the extent shown in FIG. 4, the sheet S is still in contact with the guide plate 63. Peg.

FIG. 5 shows a state in which the recording further progresses, the sheet S hangs down due to its own weight, and the guide plate 63 is in contact with the lower surface of the sheet S. At this time, sheet S
Since the curvature near the tip of the guide plate 63 is set to be smaller than that of the guide plate 63, there is no contact with the kite plate 63 up to the length of the tip of the sheet S. Therefore, even when the sheet S and the guide plate 63 come into contact, the leading edge of the sheet S contacts the guide plate 63 without hitting the guide plate 63, the generated impact is minimized, there is little disturbance in the sheet volatilization speed, and the scanning The line pitch is also uniform and good image quality can be obtained.

FIG. 6 shows the state immediately before the end of recording, and from the state shown in FIG. 5 until the end of recording, the length of the sheet S up to the leading edge is always out of contact with the guide plate 63 as shown in FIG. Therefore, even if the guide plate 63 has scratches or the like, the leading edge of the sheet s will not get caught and a good image quality can be obtained.

Moreover, air easily enters between the sheet S and the guide plate 63, and there is no possibility that the conveyance resistance of the sheet S increases and the image quality deteriorates because the two come into close contact with each other as in the conventional example.

Furthermore, since recording can be performed while maintaining a natural shape with the leading and trailing ends of the sheet S hanging down, there is less conveyance resistance of the sheet S, and there is less variation in resistance, resulting in similarly good image quality. be able to. Note that the surface of the guide plate that comes into contact with the sheet S may be not only a smooth curved surface but also an embossed surface or a rail-like surface.

For example, as shown in FIGS. 7 and 8, an oval protrusion 6
As shown in FIG. 8, the embossed plate 64 having the embossed plate 4a on one side has a small area in contact with the sheet S and is effective because the conveyance resistance is significantly reduced.

FIG. 9 shows a second embodiment, in which the device is substantially similar to the device shown in FIG. 1, but without the guide roller 61.
Two actuating rollers 65 and 66 come into contact with the drive roller 51a of the sub-scanning roller pair 51 to sandwich the sheet S.
The leading and trailing ends of the guide plates 67 and 68 are supported by guide plates 67 and 68. Here too, since the curvature of the guide plate 68 is smaller than the curvature near the tip of the sheet S, the first
Almost the same effect as in the embodiment can be obtained.

In each of the above-mentioned embodiments, when using a film coated with a photosensitive emulsion on one side of the sheet S, rubber rollers, guide plates, etc. are arranged on the base side opposite to the emulsion coated side, and on the emulsion side. is a metal that is relatively difficult to damage sheet S,
The structure is such that harmful damage to the sheet S is unlikely to occur simply by contact with the driven roller made of synthetic resin or the like.

Furthermore, the above-described embodiments are applicable not only to image recording devices but also to devices that require precise conveyance speeds, such as reading devices for radiation image information stored and recorded on stimulable phosphor sheets and image capturing devices. It goes without saying that it can be done.

r D 11th n) 6h mark] As explained above, the sheet conveying device according to the present invention allows the leading edge of the sheet during recording to be out of contact with the guide member, and the sheet can be curved without strain. The conveyance resistance and its fluctuation amount are small, making it possible to convey the sheet with high precision.

[Brief explanation of drawings]

Drawings 1 to 9 show an embodiment of a sheet conveying device according to the present invention, FIG. 1 is a configuration diagram of the first embodiment, and FIGS.
Fig. 6 is an explanatory diagram of the operation, Fig. 7 is a perspective view of the embossing plate, Fig. 8 is a side view of the embossing plate, Fig. 9 is a main part configuration diagram of the second embodiment, and Fig. 10 is a conventional It is a block diagram of an example. Year code 50 is an optical unit, 51 is a pair of sub-scanning rollers,
52 is a supply magazine, 53 is a receive magazine, 5
4 is a suction cup, 55, 56, 57 is a pair of conveying rollers, 58 is a pair of pinching rollers, 59 is a resist plate, 61 is a guide roller,
62 is a movable guide plate, 63, 67, 68 is a guide plate, 6
4 is an embossing plate, and 65 and 66 are operating rollers. Figure 3 Figure 5 Figure 6gA Figure 7 Figure 8

Claims (1)

[Claims] 1. A sheet conveying device having a sheet conveying means disposed near a position where recording or reading is performed, and a guide member that guides the sheet discharged from the sheet conveying means and recorded or read, wherein the guide member is A sheet conveying device characterized by having a curved surface that curves in the direction of gravity in an extension line direction of a sheet discharging direction of a sheet conveying means.