JPH02282133A - Sheet conveyer - Google Patents

Abstract

PURPOSE:To always stably convey a sheet even in case of using the sheet of a different size by providing, in a sheet conveying route, paired conveying rollers which can be advance and retracted. CONSTITUTION:Even in the case of using a sheet S of the minimum size in the length of its conveying direction, a sheet point end is caught by paired subscanning rollers 28 before a sheet rear end is detached from the first paired conveying rollers 27. Immediately after the above, the first paired conveying rollers 27 are retracted from a sheet conveying route. After this retraction, recording or reading is started. Consequently, no sudden change of a load is received by the sheet by restricting the sheet, being subjected to recording or reading, only by the paired subscanning rollers 28.

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] A conventional device of this type, for example, one applied to an optical image reading device is disclosed in Japanese Patent Application Laid-Open No. 63-193762.
It is disclosed in the publication No. Figure 5 shows this conventional example,
A supply magazine 2 loaded into the image reading device 1 stores a plurality of storage phosphor sheets S on which radiation images of, for example, a human body are stored and recorded. Among these sheets S, the uppermost one is sucked by the suction cup 3 and conveyed by the conveyor belt 4 and the conveyor roller 5 toward the sub-scanning roller pair 6.7, and is then conveyed between the double-layer scanning roller pair 6.7. In the image reading section 8, the image is read. The reading unit 8 includes a laser light source, a galvano mirror 1 light guide,
A laser beam is scanned in the main scanning direction on the sheet S which is transported in the sub-scanning direction, and the photomultiplier etc. are built in, and the stimulated luminescence light emitted from the sheet S is photomultiplied through the light guide. The light is guided to the pliers and converted into an electrical signal. Then, the tip of the sheet S carried out from the pair of sub-scanning rollers 7 to the right in the drawing enters the curved path formed by the guide plate 9. At this time, the pair of transport rollers 10 and 11, which are installed so as to be able to move forward and backward into the transport path through the opening of the guide plate 9, move forward and backward after reading the six images that have been moved out of the transport path by a displacement means (not shown). conveying roller pair 1O21 by means of displacement means.
1 enters the conveyance path and clamps the sheet S. The conveyance roller pair 1O111 is rotated by a drive source (not shown) and conveys the sheet S to the upper right along the guide plate 9. The sheet S is further conveyed by the conveyance roller pair 12 and the conveyance belt 13, and then is transferred to the receiver. It is configured to be stored within the magazine 14.

[Problems to be Solved by the Invention] However, the above-mentioned conventional example has various problems as shown below. The first problem is that when a sheet S whose length in the conveyance direction is greater than or equal to the length of the sheet S is used, the conveyance speed of the sheet S becomes unstable. This occurs when the trailing end of the sheet S is held between the conveyance belt 4 and the conveyance roller 5 at the time reading is started. That is, at the moment when the reading progresses and the rear end of the sheet S is released from the restraints by the conveyance rollers 5 and the conveyance belt 4, an impact is applied to the sheet S, and this impact makes the conveyance speed of the sheet S unstable, making it difficult to accurately images cannot be read.

The second problem is that when a sheet S whose length in the conveyance direction is less than or equal to the dimension is used, there is a risk that the sheet S will be conveyed diagonally. This tends to occur when the rear end of the sheet S has finished passing between the transport roller 5 and the transport belt 4 before the leading end of the sheet S is inserted into the sub-scanning roller pair 6. The sheet S is simply placed on the conveyor belt 4 without being restrained in any way and is conveyed in the direction of the sub-scanning roller pair 6 . Therefore, the force for the leading edge of the sheet S to enter between the pair of sub-scanning rollers 6 is transmitted to the sheet S by the friction of the contact surface between the conveyor belt 4 and the sheet S. In some cases, the leading edge of the sheet S instantly engages with the pair of sub-scanning rollers 6, and in other cases, the leading edge of the sheet S does not engage with the pair of sub-scanning rollers 6 for a period of time, causing slippage between the sheet S and the conveyor belt 4. be. If these two phenomena occur at the same time at the right and left ends of one sheet S, the posture of the sheet S becomes oblique with respect to the conveyance direction, and the sheet S is conveyed as it is to the reading position. Reliability during storage decreases. Furthermore, in the case of a recording device, the image is recorded diagonally with respect to the outer shape of the sheet S, which causes trouble in image interpretation.

The third problem is that in the configuration shown in FIG. 5, it is necessary to precisely synchronize the conveying speed between the sub-scanning roller pair 6.7 and the conveying belt 4, which makes the control quite complicated. It means that it will become.

If the conveyance speeds of the two sheets are different, a slip may occur between the conveyor belt 4 and the sheet S when the rear end of the sheet S being read is placed on or clamped by the conveyor belt 4. , the sheet S is bent, the load fluctuates, and the conveyance speed is adversely affected.

As mentioned above, in the conventional example shown in FIG. 5, various problems arise when the sheet S is transferred from the conveying means located upstream of the belt section that mainly performs image reading to the sub-scanning roller. ing. - For sterilization, when comparing the conveying means upstream and downstream of the sub-scanning roller section, the conditions desired for the upstream conveying means are higher. That is, the condition that the conveying speed of the sheet S during recording or reading is not adversely affected is common to both the upstream and downstream conveying means;
The sheet S is placed on the upstream side so that the sheet S is not slanted.
On the other hand, as long as the sheet S can be stored in the receive magazine 14 on the downstream side, there is no problem even if the sheet S is slanted to some extent and advances. There is some leeway left.

An object of the present invention is to improve the conveying means upstream of the sub-scanning roller section, to solve the problems of the conventional method, and to enable stable sheet conveyance at all times, regardless of the size of the sheet used. An object of the present invention is to provide a sheet conveying device that achieves the following.

[Means for Solving the Problems] In order to achieve the above object, the sheet conveying device according to the present invention includes first and second sheet conveying means that contact the sheet surface from the upstream side in the sheet conveying direction. , in a sheet conveyance device that performs recording or reading near the second sheet conveyance means, the length of the sheet conveyance path between the first and second sheet conveyance means is determined by the length of the sheet conveyance path in the conveyance direction among the sheets to be used. The length is smaller than the length of the shortest sheet, and the first sheet conveying means is supported so as to be movable in the sheet conveying path, and is retracted to a position where the sheet is not pinched while recording or reading the effective area of the sheet. It is characterized by having a mechanism.

[Function] In the sheet conveying device having the above configuration, even when using a sheet having the shortest length in the conveying direction, the trailing edge of the sheet is
The leading edge of the sheet is pinched by the sub-scanning roller pair before it leaves the first pair of conveyance rollers, and immediately after that, the first pair of conveyance rollers is retracted from the sheet conveyance path, and recording or reading is started after the evacuation. Alternatively, the sheet being read is restrained only by the pair of sub-scanning rollers, and is not subject to sudden load fluctuations.

[Example] The present invention will be explained in detail based on the example illustrated in FIGS. 1 to 4.

FIG. 1 shows an embodiment in which the present invention is applied to a medical image recording apparatus. This type of image recording device records an image by main-scanning a laser beam on a recording sheet conveyed in the sub-scanning direction.
For example, the size of the recording sheet S, which is a photosensitive film, is cut in half (approximately 35 x 43 cm) or large square (approximately 35 x 3 cm).
5 cm), large mouth (approximately 28 x 35 cm), etc. In FIG. 1, reference numeral 21 indicates the main body of the image recording apparatus, and a supply magazine 22 loaded in an almost horizontal direction contains a large number of unused recording sheets S of the same size stacked together. 0 As is well known, when the supply magazine 22 is loaded into the apparatus main body l, it is loaded with the lid closed, and after loading, if the light-shielding property inside the apparatus main body l is ensured, the supply magazine 22 is loaded into the apparatus main body l. The lid is opened by a lid opening/closing mechanism, and the uppermost one of the sheets S inside can be taken out using a suction cup 23. Suction cup 23
The leading edge of the sheet S attracted by the three rollers 2
After that, the suction force of the suction cup 23 is released, and the sheet S is conveyed downward by the driving force of the conveyance roller 26. Note that a one-way clutch is installed between the conveyance roller 26 and its drive source, so that even if the drive source is stopped, the seat can be easily moved between the conveyance roller 26 and the belt 25 toward the left in the drawing. It can be inserted into.

The sheet SC±, which is sandwiched between the conveyance roller 26 and the belt 25 and whose orientation is changed in the vertical direction, ie, the sub-scanning direction, is taken over by the first conveyance roller pair 27 and the second conveyance roller pair, ie, the sub-scanning roller pair 28. They are conveyed one after another, and then stored in the receive magazine 29 by free fall. On the way, just before the pair of sub-scanning rollers 28, main scanning is performed by the laser beam B from the optical unit 30.

A guide plate 31 for regulating the position of the sheet S is provided between the transport roller 26 and the transport roller pair 27, and a similar guide plate 32 is provided between the transport roller pair 27 and the sub-scanning roller pair 28. The laser beam B
is now irradiated. Note that the guide plate 31.
The inner surface of 32 is finished smoothly to minimize friction with the sheet S. The first pair of conveyance rollers 27 is supported so as to be movable back and forth in the sheet conveyance path by an advance/retreat mechanism to be described later, and in the case of FIG. At this position, it does not come into contact with the sheet S.

As shown in FIG. 1, when the pair of conveyance rollers 27 enters the sheet conveyance path, the distance L1 of the conveyance path between the pair of conveyance rollers 27 and the pair of sub-scanning rollers 28 is determined by the distance L1 of the conveyance path of the sheets S of various sizes used. Among them, the length in the transport direction is smaller than the length of the shortest sheet S. Therefore, even when using the sheet S with the shortest length in the transport direction, the sheet S
Before the rear end leaves the pair of transport rollers 27, the leading edge of the sheet s is sandwiched between the pair of sub-scanning rollers 28.

Immediately after the leading end of the sheet S is sandwiched between the pair of sub-scanning rollers 28, the first pair of conveying rollers 27 is retracted from the sheet conveying path by the advancing/retracting mechanism, and after the retraction, recording is started.

Optical unit for recording /) 30 is from the laser light source (
7) Built-in polygon mirror etc. for scanning the L/-f beam B, and the emitted laser beam B passes through the mirror 3.
3 and main-scans the sheet S being conveyed in the sub-scanning direction to record an image. After the recorded sheet S leaves the sub-scanning roller pair 28, it falls due to its own weight and is stored in the receive magazine 29. The receive magazine 29 is installed at an angle of approximately 20 degrees with respect to the vertical line, and the lid 29a, which is opened and closed using its lower end as a fulcrum, is opened approximately vertically. When this receive magazine 29 is also installed in the equipment main body 1, the M
29a is set in an open state, and the knife to be taken out is pulled out after closing the lid using the same lid opening/closing mechanism so that the recorded sheet S stored inside is not exposed to light. In FIG. 1, reference numeral 34 indicates a controller unit including a control circuit, a power supply, etc. for controlling the entire apparatus.

With this configuration, the sheet S being conveyed does not fall freely until the recording is completed, and is always restrained by either roller pair 27 or 28. Therefore,
During this time, there is no possibility that the sheet S will be tilted due to free fall, and there is no risk of the main scanning being performed diagonally with respect to the outline of the sheet S. Also, the sheet S being recorded is restrained only by the sub-scanning roller pair 28. Therefore, the leading edge and trailing edge of the sheet S will not be inserted into or released from another pair of rollers during recording. Therefore, sudden load fluctuations will not occur on the sheet S during recording. The conveying speed of the sheet S becomes constant, and unevenness in the conveying speed that causes image quality deterioration does not occur, and even if the size of the sheet S used differs, stable conveyance is always possible. Furthermore, there is no need to synchronize the outer circumferential speed of the sub-scanning roller pair 28 during recording with other roller pairs, which greatly facilitates control.

Here, if sub-scanning unevenness is not a problem, it is possible to perform recording before the leading edge of the sheet S reaches the pair of sub-scanning rollers 28. For example, a high-intensity recording beam may be applied to the leading edge of the sheet S. It is also easy to paint the leading edge of the sheet S black after irradiation and development. This is because pitch irregularities caused by scanning lines are less noticeable in the blacked out areas, and even if there is pitch irregularity, the purpose of blocking unnecessary light during image interpretation can be fully achieved. .

Next, an example of the advancing/retracting mechanism for the first pair of conveying rollers 27 will be explained below.
3 and 3 will be explained. In FIGS. 2 and 3, 21a is a frame of the device, which is actually opposed to another frame 21b (not shown) having a symmetrical shape, and both frames 21a and 21b are separated by an appropriate distance. They are separated and connected by a connecting member. frame 21
A shows the shaft 24a of the three rollers 24 shown in FIG.

The shaft 28a of the conveyance roller 26 and the shaft 3 of the cam 35, which will be described later.
5a is rotatably supported, and the other ends of these shafts are held by the frame 12b. A driving-side roller 27a and a driven-side roller 27b forming the transport roller pair 27
are attached to one end of a lever 38 and a lever 39 via a shaft 36 and a shaft 37, respectively, the other end of the lever 38 is attached via a shaft 40, and the intermediate portion of the lever 39 is attached via a shaft 41. Each is rotatably attached to the frame 21a. The lever 38 is biased clockwise by a spring 42 attached to the 4° shaft, and a stopper 43 restricts the limit of its rotation in the clockwise direction.

On the other hand, the lever 39 is connected to a spring 44 attached to the shaft 41.
As a result, the roller 27b is always pressed toward the roller 27a. However, the elastic force of the spring 44 is set smaller than the elastic force of the spring 42, and when the sheet S is inserted between the rollers 27a and 27b, the lever 38 does not move and only the lever 39 moves. It is designed to move according to its thickness. Further, the lever 38 and the lever 39 are connected to the cam 35.
Each time the sheet S passes by, exactly, the leading edge of the sheet S is retracted to a position where it does not come into contact with the sheet S immediately after it is sandwiched between the next pair of sub-scanning rollers 28.

In the embodiment, the cam 35 connects the convex portion 38a that protrudes laterally from the intermediate portion of the lever 38 and the other end portion 39a of the lever 39.
By rotating the lever 38 by approximately 180 degrees, the lever 38 is simultaneously rotated counterclockwise and the lever 39 is rotated clockwise, thereby rotating the roller 27a and the roller 27b respectively to 27a.
It is designed to be evacuated to the position shown at 27b°. In addition, when the cam 35 rotates once, the spring 42
and the roller 27a and the roller 2 by the spring 44.
7b is returned to its original position, that is, the position where it contacts the sheet S. A sprocket 45 is attached to the shaft 39a of the cam 35, and is connected by a chain 48 to a sprocket 47 attached to the shaft 46a of a cam drive electric motor 46. Note that the cam drive electric motor 46 is attached to the frame 21a.
It is removably fixed to a long mounting hole 49 provided in the mounting hole 49 with a fixing screw 50, and can be moved slightly along the mounting hole 49 when the chain 48 is attached or removed. Of course, cam 35, lever 38
, lever 39. Spring 42, stopper 43. The spring 44 and the like are also symmetrically provided on the other side of the frame 21b, which is not shown in FIG. Conveyance roller 2
6 and a sprocket 52 attached to a shaft 51a of a conveyance roller driving electric motor 51 that drives the roller 27a;
A chain 55 is hung between a sprocket 53 attached to the shaft 26a of the conveyance roller 26 and a sprocket 54 attached to the shaft 40. Note that the sprocket 53 is attached to the shaft 26a via the one-way clutch 56, as described above.

As shown in FIG. 3, the sprocket 54 is an idler sprocket made by connecting two sprockets, and a chain 58 is hung between one of the sprockets and a sprocket 57 attached to the shaft 36. Therefore, the sprocket 5 is
4 is driven, the sprocket 57 and roller 27a are simultaneously rotated via the chain 58. Here, it goes without saying that each sprocket is selected so that the outer peripheral speeds of the conveying roller 26 and the roller 27a are equal. Further, since the fulcrum of the lever 38 and the rotation center of the sprocket 54 coincide, the rotation of the lever 38 is not hindered.

In addition, similarly to the cam drive electric motor 46, the conveyance roller driving electric motor 41151 is also fixed so that it can be removed by inserting a fixing screw 50 into a long mounting hole 49 provided in the frame 21a, and can be moved slightly in position. has been done.

Since the sub-scanning roller pair 28 shown in FIG. 1 is driven by a sub-scanning-only electric motor (not shown), the outer circumferential speeds of the conveyance roller pair 27 and the sub-scanning roller pair 28 driven by the conveyance roller driving electric motor 51 should be different. However, when at least one sheet S is sandwiched between the transport roller pair 27 and the sub-scanning roller pair 28 at the same time, the outer peripheral speeds of both roller pairs 27 and 28 are set to be approximately concave. has been done.

In the embodiment shown in FIG. 1, the sheet S after being separated from the sub-scanning roller pair 28 is allowed to fall freely due to its own weight and is stored in the receive magazine 29. It is also possible to store it. Also,
A first pair of conveying rollers 2 that can move forward and backward into the sheet conveying path
7 does not necessarily have to have the same diameter over the entire width of the sheet S. For example, only the left end, center, and right end of the sheet S are sandwiched between the roller pair 27, and the other parts are sandwiched between the roller pairs 27. In this case, the guide plate 31 and the guide plate 32 may be made continuous and integrated, and an opening may be provided only in the portion into which the roller pair 27 enters.

Next, FIG. 4 shows another embodiment, in which the supply magazine 22 is arranged below and recording is performed while conveying the sheet S upward, upstream from the recording section. The functions of each part are the same as in the case of FIG. 1, except that the direction of conveyance is different on both sides, so a description thereof will be omitted. Note that in FIG. 4, the same reference numerals as in FIG. 1 represent equivalent members.

In this embodiment, the sub-scanning roller pair consists of a sub-scanning roller 61 on the driving side and two nip rollers 62a, 62b, and the laser beam B from the optical unit 30 is irradiated between these nip rollers 62a, 62b to I'm trying to do a scan. Here, the distance fiL1 from the first conveying roller pair 27 to the contact point between the sub-scanning roller 61 and the nip roller 62a constituting the second conveying roller pair is determined in the same way as in the case of FIG. The length in the transport direction is equal to or less than the length of the shortest sheet S.

In this embodiment, since free falling cannot be used due to its own weight as a means for separating the sheet S after printing from the pair of sub-scanning rollers, a third conveyor that can move forward and backward into the sheet conveyance path is also provided on the downstream side of the pair of sub-scanning rollers. A roller pair 63 is arranged. A distance 111 from the contact point between the sub-scanning roller 61 and the roller 62b to the third conveyance roller pair 63
1L2 also has the same conditions as Ll. Further, like the first pair of conveyor rollers 27, the pair of conveyor rollers 63 is retracted during recording by an advance/retreat mechanism, and after recording is completed, it enters the sheet conveyance path and is rotated by a drive source (not shown) to move the sheet S upward. It is designed to be transported to The sheet S conveyed upward by the third pair of conveyance rollers 63 is sandwiched between the conveyance roller 64 and the belt 66 hooked on the third roller 65, and after changing its orientation in the horizontal direction, Bush lever 6 rotated by a predetermined angle around 67
8 and is housed in the receive magazine 29, and is completely pushed into the receive magazine 29 by a presser 69 that is driven in the vertical direction. In addition, 70.7
Reference numeral 1 indicates a guide plate that guides the sheet S.

Also in the configuration shown in FIG. 4, it is possible to carry out stable sheet conveyance regardless of the size of the sheet S used, as in the case of FIG. 1.

Note that the present invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the claims. For example, the conveying direction of the sheet during recording is not limited to the vertical direction, but may be horizontal or diagonal. Moreover, the conveying path of the sheet during recording is not limited to a straight line but may be a curved line. It goes without saying that the present invention is applicable not only to image recording apparatuses but also to image reading apparatuses and the like.

[Effects of the Invention] As explained above, the sheet conveyance device according to the present invention provides stable sheet conveyance at all times even when sheets of different sizes are used by providing a pair of conveyance rollers that can advance and retreat in the sheet conveyance path. It is possible.

[Brief explanation of drawings]

Drawings 1 to 4 show embodiments of the sheet conveying device according to the present invention, in which FIG. 1 is a configuration diagram of the first embodiment, 2m is a configuration diagram of a part of its internal mechanism, and 3. The figure is a side view thereof, FIG. 4 is a block diagram of the second embodiment, and FIG. 5 is a block diagram of a conventional example. Reference numeral 21 is an image recording device, 22 is a supply magazine, 2
5.66 is the belt, 26.64 is the conveyance roller, 27.6
3 is a transport roller pair, 28 is a sub-scanning roller pair, 29 is a receive magazine, 30 is an optical unit, 31.32.70
．． 71 is a guide plate, 35 is a cam, 38.39 is a lever,
42 and 44 are springs, 43 is a stopper, 46 is a cam drive motor, and 51 is a transport roller drive motor. 45.47.52, 53.54.57 are sprockets,
4g, 55.58 is a chain, 61 is a sub-scanning roller, 6
2a and 62b are nip rollers. Patent applicant: Canon Co., Ltd. Ii1 Figure 3 Figure M4 Figure 5

Claims (1)

[Claims] 1. The first contacting with the sheet surface from the upstream side in the sheet conveyance direction
, in a sheet conveying device that includes a second sheet conveying means and performs recording or reading near the second sheet conveying means, the length of the sheet conveying path between the first and second sheet conveying means is: Among the sheets used, the length in the conveying direction is smaller than the length of the shortest sheet, the first sheet conveying means is supported movably in the sheet conveying path, and the effective area of the sheet is recorded or read. A sheet conveying device characterized by being equipped with an advancing/retracting mechanism for retracting a sheet to a position where it is not pinched.