JPH04286560A - Sheet body feeding device - Google Patents

Abstract

PURPOSE:To record a desirable image by delivering a sheet body positively without unevenness in conveyance from an auxiliary scanning part provided at the sheet bode feeding device of an image recording device using laser beams. CONSTITUTION:A sheet body feeding device 2 is formed of an auxiliary scanning part 7 for feeding a sheet body (photosensitive material) 10 out to an exposure recording part 9 orthogonally to main scanning scanned by laser beams 8, plural pairs of carrier rollers 3 for conveying the photosensitive material to the auxiliary scanning part 7, upper and lower guide plates 4 and a detecting means 6, and its carrier path is curved in the carrier direction. At the time of being conveyed to the auxiliary scanning part 7, the photosensitive material 10 is conveyed being held by the respective carrier roller pairs 3. When the photosensitive material 10 is delivered out of the auxiliary scanning part 7, switching is performed so that the holding of the respective carrier roller pairs 3 is released to lift the lower guide plates 4b and the photosensitive material 10 is delivered out by the conveyor means of the auxiliary scanning part 7 and the guide faces of the guide plates 4b. The photosensitive material 10 is thereby sent out by the independent precision conveyor mechanism of the auxiliary scanning part 7, the smooth face of the guide plates 4 and the curved carrier path, so that unevenness in conveyance can be prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a feeding device for feeding a sheet to an exposure recording section of an image forming apparatus that records an image by irradiating the sheet with a light beam.

0002

2. Description of the Related Art In an image recording apparatus that exposes and records a sheet (photosensitive material) using a laser beam, a rotating polygon mirror is irradiated with a laser beam modulated based on image information from a diagnostic device, for example. A desired image is recorded on the surface of the photosensitive material by operating in synchronization with a main scan that scans the surface of the material and a sub-scan that is perpendicular to the scanning direction of the main scan and sends the photosensitive material to the exposure recording section. be done.

[0003]The photosensitive material is fed to the exposure recording section where the laser beam is irradiated by using a precision conveying mechanism with extremely little speed fluctuation in the entire feeding device so that a good image is always recorded. There is.

0004

[Problems to be Solved by the Invention] However, in order to record good images, if a precision transport mechanism is used for the entire transport means of the feed device, the cost will be extremely high and it is undesirable. It is generally applied only to

In such a case, since the conveying speeds of the conveying means of the sub-scanning section and the conveying means for conveying the photosensitive material to the sub-scanning section do not necessarily match, the photosensitive material is irregularly sent to the exposure recording section and is often not recorded. The disadvantage is that the resulting image is distorted.

In order to avoid such a phenomenon, it is preferable that the photosensitive material, which is conveyed to the sub-scanning section by, for example, the nipping and rotation of conveyance rollers or a conveyance belt, be inserted into the sub-scanning section. Even when the nip is released, the photosensitive material is inevitably conveyed while contacting the roller surface or the belt surface. In such a case, each conveyance surface of the conveyance roller and the conveyance belt is made of a material or has a surface shape with a large friction coefficient in order to obtain conveyance force, so a load is applied to the conveyance means of the sub-scanning section. Frequently, fluctuations occur in the delivery to the exposure section, causing disturbances in the recorded image as described above.

[0007]Furthermore, when the photosensitive material that has passed through the exposure recording section falls to a switching unit which is provided below and sends it to an automatic processor or the like, the photosensitive material falls while being curved with a certain curvature.

[0008] If the conveying path of the feeding device to the sub-scanning section is smaller than the curvature of the photosensitive material when it falls, or is flat, the moment the trailing edge of the photosensitive material leaves the sub-scanning section. The elastically deformed photosensitive material tries to return to its original state and bounces, causing uneven conveyance in the exposure recording section and causing disturbances in the recorded image.

The present invention solves these problems and stably feeds a sheet-like photosensitive material to the exposure recording section of an image recording device using a feeding device having an inexpensive structure, thereby recording good images at all times. The purpose of the present invention is to provide a sheet feeding device that can perform the following tasks.

0010

[Means for solving the problem] This purpose is as follows:
This can be achieved by any means.

(a) A sheet having a sub-scanning section that sends the sheet to an exposure recording section perpendicular to the main scanning in which the sheet is irradiated with a light beam, and a conveyance means that conveys the sheet to the sub-scanning section. In the body feeding device, the feeding device includes a conveying means that sandwiches the sheet body and changes its position so as to be able to come into contact with and separate from it, a guide member that can change the mutual distance or position, and a detection means that detects the position of the sheet body. and the sub-scanning section to form a conveying path, the sheet body reaching the sub-scanning section by the conveying means is detected by the detecting means to release the clamping of the conveying means, and the interval between the guide members is adjusted. Alternatively, the sheet feeding device is characterized in that the position is changed so that when the sub-scanning section feeds out the sheet, the sheet is fed out by the conveying means of the sub-scanning section alone and the guide surface of the guide member.

(b) The sheet conveying device according to item (a), wherein the guide surface of the guide member and the conveying path are curved in the conveying direction.

[0013]

[Embodiment] An embodiment of the present invention is shown in the side sectional view showing the structure of a sheet body feeding device in FIG. 1 and the state in which a sheet body is pinched and conveyed by the conveying means of the feeding device, and the same front sectional view in FIG. This will be explained with reference to a side sectional view showing the operating state of the sheet feeding device when the sheet shown in FIG. 3 is fed to the exposure recording section by the sub-scanning section. However, the present invention is not limited to this example.

In an image recording device that exposes and records a sheet (hereinafter referred to as a photosensitive material) using laser light, for example, a rotating polygon mirror is irradiated with a laser beam modulated based on image information from a diagnostic device. The main scan that scans the surface of the material and the sub-scan that is perpendicular to the scanning direction of the main scan and sends the photosensitive material to the exposure recording section operate in synchronization with each other, so that a desired image is formed on the surface of the photosensitive material. recorded. In order to solve the above-mentioned problems, the present invention has constructed a sheet body feeding device as follows.

That is, as shown in FIG. 1, a feeding device 2 that feeds a sheet-like photosensitive material 10 to an exposure recording section 9 of an image recording apparatus 1 includes a plurality of pairs of conveying rollers 3 that nip and convey the photosensitive material 10, and Between the transport roller pair 3 and the sub-scanning section 7, there is a pair of guide plates 4 facing upwardly and downwardly, a detection means 6 for detecting the position of the photosensitive material 10, and the photosensitive material 10 is sent to the exposure recording section 9. and the sub-scanning section 7, each of which forms a transport path for the photosensitive material 10.

As shown in FIG. 2, the conveying roller pair 3, which is composed of an upper conveying roller 3a and a lower conveying roller 3b, is rotated by both side plates 2a provided on the frame of the feeding device 2. Support shafts 5a, 5 that are freely supported
b, and are divided and arranged at approximately equal intervals (four rows in the illustrated example) at appropriate lengths across the width direction perpendicular to the transport direction of the photosensitive material 10. The length in the width direction of the pair of transport rollers 3 is the same as that of the existing sheet-shaped photosensitive material 10.
The length is sufficient to convey the maximum width of the

Furthermore, each of the conveying roller pairs 3 is shown in FIG.
As shown in , predetermined conveyance paths extending between the conveyance roller pair 3 provided at the entrance in the conveyance direction of the photosensitive material 10 and the sub-scanning section 7 are arranged at approximately equal intervals with appropriate intervals (in the figure, three The upper conveying rollers 3a are fixed to the both side plates 2a at a predetermined position and rotated, and the upper conveying rollers 3a are provided so as to be able to move toward and away from the lower conveying rollers 3b upward and downward. .

When each of the upper conveying rollers 3a moves upward, the lower surface of the roller is located above and away from the guide surface of an upper guide plate 4a, which will be described later.

The four rows of upper conveyance rollers 3a including the entrance are vertically shifted simultaneously at approximately equal intervals relative to the lower conveyance rollers 3b.

FIG. 1 shows the state in which the sheet-shaped photosensitive material 10 is conveyed to the sub-scanning section 7.
are held between the respective conveying roller pairs 3.

Although not shown, the feeding device 2
The drive transmission means transmits rotation by a drive source connected to the support shaft 5b of the lower conveyance roller 3b at the entrance located at the left end, and the rotation is transmitted between the lower conveyance roller 3b at the entrance and the side up to the sub-scanning section 7. The rotation is transmitted via a gear or a timing belt that connects each lower conveyance roller 3b.

Accordingly, the lower conveyance roller 3b is a driving roller, and the upper conveyance rollers 3a that are pressed against it are driven rollers.

Although not shown in the drawings, each of the upper rollers 3a has both ends of the respective support shafts 5b integrally connected by a connecting plate, and a cam or the like acting on the connecting plate allows the upper conveying rollers 3a to move upwardly, It is designed to operate at the same time. The sub-scanning section 7 is composed of a pair of conveyance rollers, and a dedicated motor is connected to the lower conveyance roller 7b, which forms a precision conveyance mechanism together with the upper conveyance roller 7a, and synchronizes with the main scanning of the laser beam 8. The photosensitive material 10 is rotated to send out the photosensitive material 10 to the exposure recording section 9.

As shown in FIG. 1, the guide plate 4 is arranged on the upper side facing between the conveying roller pairs 3 and the sub-scanning section 7 arranged in the conveying direction of the photosensitive material 10. It is composed of a guide plate 4a and a lower guide plate 4b, and together with each of the conveyance roller pairs 3 and the sub-scanning section 7, forms a conveyance path for the photosensitive material 10.

Furthermore, as shown in FIG. 2, the guide plate 4 is arranged with an appropriate width between each pair of conveying rollers 3 which are divided and arranged in the width direction in which the photosensitive material 10 is conveyed. has been done.

The upper and lower guide plates 4a and 4b are each formed of an integral member so as not to interfere with each of the upper and lower conveyance rollers 3a and 3b, and the lower guide plate 4b that operates in the vertical direction is connected to the upper and lower conveyance rollers. It is connected to the connecting plate that connects the upper conveying rollers 3a and operates integrally with the vertical movement of the upper conveying roller 3a. When the lower guide plate 4b is shifted upward, the distance between the lower guide plate 4b and the upper guide plate 4a, which is positioned above and fixed to each lower conveyance surface of each of the lower conveyance rollers 3b, is reduced.

The guide surfaces of the photosensitive material 10 of the upper and lower guide plates 4a and 4b are finished as smooth surfaces with extremely low coefficients of friction.

A detecting section 6 is provided adjacent to the left side of the sub-scanning section 7, and when the leading edge of the photosensitive material 10 conveyed by each of the conveying roller pairs 3 reaches the insertion position of the sub-scanning section 7. This detection information drives the aforementioned cams to raise each of the upper conveyance rollers 3a and the lower guide plate 4b to predetermined positions.

Then, as shown in FIG.
The guide plate 4 is formed so that the conveying path is curved at a predetermined curvature, and the conveying roller pairs 3 and the sub-scanning section 7
are also arranged following this curvature. The curvature of this curve is formed to approximately match the curvature drawn when the photosensitive material 10 is sent out from the sub-scanning section 7 and falls onto the switching unit 11 disposed below.

The operation of transporting the photosensitive material 10 by the transport device 2 constructed in this way will be explained next.

The sheet-like photosensitive material 10 housed in the magazine is taken out one by one by a suction cup or the like and inserted into the pair of conveying rollers 3 at the entrance located at the left end of the feeding device 2 in the direction of the arrow. 3, the paper is conveyed in the direction of the sub-scanning section 7 while being curved along a predetermined conveyance path via the respective guide plates 4 and the respective conveyance rollers 3 disposed successively. When the leading end of the photosensitive material 10 reaches the vicinity of the sub-scanning section 7 and is detected by the detection section 6 and embedded in the rotating sub-scanning section 7, the above-mentioned cam mechanism is driven by the detected information. The upper transport rollers 3a and the lower guide plate 4b, which are connected to each other, are simultaneously raised to a predetermined position in the direction of the arrow. Then, the upper conveying rollers 3a are released from being held between the lower conveying rollers 3b, and the conveying surfaces of the upper conveying rollers 3a are positioned above the guide surface of the upper guide plate 4a and stop rotating. At the same time, the guide surface of the lower guide plate 4b is connected to each of the lower conveyance rollers 3.
The distance between the upper guide plate 4a and the opposing upper guide plate 4a located above the conveyance surface b is reduced.

Note that the sub-scanning section 7 of the photosensitive material 10
Although it is desirable that the insertion into the substrate, the release of the nip of each pair of conveyance rollers 3, and the movement of the lower guide plate 4b be carried out simultaneously, in the present invention, feeding to the exposure recording section 9 by the sub-scanning section 7 is made more reliable. Therefore, after the leading end of the photosensitive material 10 is embedded in the sub-scanning section 7, the grip between the conveying roller pairs 3 is released at a predetermined time lag, and the lower guide plate 4 is released.
b is set to move. The photosensitive material 10 that has been released from the nip between the conveyance roller pairs 3 is sent to the exposure recording section 9 where the laser beam 8 scans by the precision conveyance mechanism of the sub-scanning section 7 alone. By scanning and the sub-main scanning section 7, desired images are recorded one after another on the surface of the photosensitive material 10. When the rear end of the photosensitive material 10 passes through the detection section 6, it is detected and drives the aforementioned cam mechanism to lower each of the upper conveyance rollers 3a and contact the conveyance rollers 3b;
While rotating again, the lower guide plate 4b is also lowered to return to a predetermined position and waits for conveying the next photosensitive material 10.

The photosensitive material 10, on which the image has been recorded by the exposure recording section 9, is bent while drawing a constant curvature in the direction of the arrow, and is dropped into the switching unit 11 located below, and then subjected to the next step. sent to.

In this way, when an image is exposed and recorded on the photosensitive material 10, the upper scanning section 7 is switched to the precision conveyance mechanism of the sub-scanning section 7 alone without receiving any frictional resistance from the conveyance roller pairs 3. Since the photosensitive material 10 is fed out following the guide surfaces of the lower guide plates 4a and 4b, it can be stably fed to the exposure recording section 9 without uneven conveyance, and since the conveyance path is curved, the photosensitive material 10 can be fed out in the sub-scanning direction. Since there is no splashing up when leaving the section 7, good images are always recorded.

Note that the photosensitive material 10 is transferred to the sub-scanning section 7.
It is perfectly acceptable to use a conveying belt in place of the respective conveying roller pairs 3 for conveying the paper up to the point.

[0036]

Effects of the Invention The sheet feeding device of the present invention allows the sheet (photosensitive material) to be accurately fed from the sub-scanning section to the exposure recording section without any unevenness in conveyance, and when the sheet moves away from the sub-scanning section, Since the image quality no longer increases, good images are always recorded.

Furthermore, the sheet conveyance device of the present invention has a precision conveyance mechanism applied only to the sub-scanning section, and ordinary conveyance mechanisms are used for the other conveyance means, so that it is constructed at an extremely low cost.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view showing the configuration of a sheet body feeding device according to an embodiment of the present invention and a state in which a sheet body is pinched and conveyed by the conveyance means of the feeding device. FIG. 2 is a front sectional view of the same. FIG. 3 is a side sectional view showing the operating state of the sheet feeding device when the sheet is fed to the exposure recording section by the sub-scanning section according to one embodiment of the present invention.

[Explanation of symbols]

1...Image recording device
2... Sheet body feeding device 3... Conveyance roller pair
3a...Upper conveyance roller 3b...Lower conveyance roller
4...Guide plate 4a...Upper guide plate
4b...lower guide plate 6...detection means
7...Sub-scanning section 8...Laser beam
9... Exposure recording section 10... Sheet body (photosensitive material)

Claims (2)

[Claims] 1. A sheet body comprising: a sub-scanning section that feeds the sheet body to an exposure recording section perpendicular to a main scanning scan that irradiates the sheet body with a light beam; and a conveyance means that conveys the sheet body to the sub-scanning section. In the feeding device, the feeding device includes a conveying means that sandwiches the sheet body and changes its position so as to be able to move toward and away from it, a guide member whose mutual distance or position can be changed, a detection means that detects the position of the sheet body, and the and a sub-scanning section to form a conveyance path, the sheet body reaching the sub-scanning section by the conveyance means is detected by the detection means to release the clamping of the conveyance means, and the interval between the guide members or A sheet feeding device characterized in that when the position is changed and the sub-scanning section feeds the sheet, the sheet is fed out by means of a conveying means of the sub-scanning section alone and a guide surface of the guide member. 2. The sheet conveying device according to claim 1, wherein the guide surface of the guide member and the conveying path are curved in the conveying direction.