JP2002003008A - Conveying method and device for sheet-like recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep constant the conveying velocity of recording materials regardless of the types of them. SOLUTION: Information of the types of a recording paper sheet 30 is input from a type input part 72. A controller 67 reads the pulse rate value corresponding to the input type information from a memory 71 for driving a feeding motor 64 (pulse motor). The pulse rate value is defined to be small when the recording paper sheet 30 is thick or short in the width direction so as to decrease the rotating velocity of the capstan rollers 60, 61. As a result, the conveying velocity involved with the shift of the nip pressure is restrained so that the recording paper sheet 30 is constantly conveyed at the defined velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for conveying a recording material in the form of a sheet, and more particularly to a method and an apparatus for conveying a recording material by suppressing a speed fluctuation due to deformation of a pair of rollers used for conveying the recording material. The present invention relates to a method and apparatus for precisely transporting.

[0002]

2. Description of the Related Art For example, in a photographic printer, an image is recorded on a recording material by carrying out scanning exposure in a main scanning direction perpendicular to the sheet while transporting the recording material in a sub-scanning direction. The sub-scanning conveyance means for conveying the recording material includes a pair of feed rollers for nipping and conveying the recording material to the exposure position, and a feed roller rotating at the same speed as the pair of feed rollers and conveying the recorded recording material. Consists of pairs.

[0003] The feed roller pair and the feed roller pair are designed so that they can be conveyed at a constant speed even when the type of recording paper sheet, especially the thickness or width of the sheet, is different.
A hard roller having good dimensional stability is used. The frictional force generated between the hard roller and the recording paper sheet is very small, and the hard roller easily slips with the recording paper sheet. If the nip pressure between the hard rollers is excessively increased in order to suppress such speed fluctuation due to slip, the recording paper sheet may be deformed.

Therefore, a rubber roller in which the surface of a hard roller is coated with an elastic material such as silicon rubber is used. Thereby, a constant frictional force is secured between the recording paper sheet and the elastic body, and the recording paper sheet does not slip.
Further, since it is not necessary to excessively increase the nip pressure between the rubber rollers, it is possible to prevent the recording paper sheet from being deformed.

[0005]

Here, as shown in FIG. 9A, when a capstan roller 101 and a nip roller 102 for sandwiching and conveying a recording paper sheet 100 are covered with an elastic material, the elastic force is generated by the nip pressure. The body deforms and a
The portion of the elastic body from the point b to the point abuts on the recording paper sheet 100. On the other hand, recording paper sheets 103 having different thicknesses and widths
, The nip pressure between the rollers fluctuates. Here, when the nip pressure increases, as shown in FIG.
The elastic body is further deformed, and the portion between the points a ′ and b ′ comes into contact with the recording sheet 103. The apparent roller diameter becomes larger, and the length L2 between the points a ′ and b ′ becomes longer than the length L1 between the points a and b.

On the other hand, the rotation angle θ between the arcs a and b is constant regardless of the amount of deformation of the roller. When the characteristics of the driving motor 104 are constant, the rotational angular velocity of the capstan roller 101 is also constant. Therefore, when the amount of deformation of the elastic body is large, the amount of feed per unit time increases. Therefore,
The quality of the printed photo varies depending on the amount of deformation of the elastic body covering the roller.

The present invention has been made in view of the above circumstances, and a method of conveying a sheet-shaped recording material capable of precisely conveying a recording material by effectively suppressing speed fluctuation due to deformation of a roller pair. And an apparatus.

[0008]

In order to solve the above-mentioned problems, a method of conveying a sheet-like recording material according to the present invention comprises coating a roller constituting a pair of conveying rollers for nipping and conveying the recording material with an elastic body. The rotational speed of the transport roller pair is reduced as the recording material becomes thicker. Further, the sheet-like recording material conveying method according to the present invention is characterized in that each of the rollers constituting a conveying roller pair for nipping and conveying the recording material is covered with an elastic body, and as the recording material becomes shorter in the width direction, the conveying roller The rotation speed of the pair is reduced. Thereby, even if the thickness and width of the recording material are different, the conveying speed can be kept constant.

The sheet-like recording material conveying apparatus of the present invention comprises:
At least one pair of transport rollers for nipping and transporting the recording material, an elastic body covering each roller constituting the transport roller pair, and the rotation speed of the transport roller pair decreases as the recording material becomes thicker. As described above. Further, the sheet-like recording material conveying apparatus of the present invention includes at least one pair of conveying rollers for nipping and conveying the recording material, an elastic body covering each roller constituting the pair of conveying rollers, and the recording material having a width. And a drive control unit that controls the operation so that the rotation speed of the pair of transport rollers decreases as the distance in the direction decreases.

Further, the drive control means includes a storage device in which rotational speed information determined according to the thickness and width of the recording material is stored, and the rotational speed information according to the type of the recording material to be conveyed is stored. It is preferable that the rotation speed of the transport roller pair is adjusted by reading from the storage device. Further, the transport roller pair may be configured by a feed roller pair that transports the recording material to an exposure position where the recording light is irradiated, and a feed roller pair that transports the exposed recording material to the developing device. Further, each roller constituting the transport roller may be a skewed roller.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a printer processor. A printer processor 10 includes a printer 11 and a processor 12 connected to each other. The printer 11 includes a paper loading unit 13 and a paper cutter 1.
4, a back printing device 15, an exposure unit 16, and a paper sorting unit 17. The processor 12 includes the developing device 2
0, squeeze roller 21, drying device 22, stacking device 23
Consists of

The paper loading section 13 is loaded with a paper magazine 24. In this paper magazine 24,
A recording paper roll 26 in which a sheet-like photosensitive recording paper 25 is wound into a roll shape is stored. This photosensitive recording paper 25
Is formed by coating a composition obtained by mixing and dispersing a white pigment in a resin containing, for example, a polyester, on at least the surface of the substrate formed of a base paper or the like on the emulsion application side (image recording side). Further, a paper feed roller pair 27 is provided in the paper magazine 24, and when the paper feed roller pair 27 is rotated clockwise in the drawing by a feed drive motor (not shown), the photosensitive recording paper 25 is pulled out from the recording paper roll 26, The paper is sent to the paper cutter 14.

The paper cutter 14 includes a fixed blade 14a and a movable blade 14b, and is disposed between the paper loading unit 13 and the back printing unit 15. When the leading end of the photosensitive recording paper 25 is sent out from the paper cutter 14 by a predetermined length,
A cutter driving mechanism (not shown) operates to move the movable blade 14b toward the fixed blade 14a, and cuts the photosensitive recording paper 25 into a cut sheet-like recording paper sheet 30. The recording paper sheet 30 is transported to the back printing device 15 and the exposure unit 16 along a plurality of transport roller pairs 31 and a guide plate (not shown).

In the back printing device 15, necessary information is printed on the back surface (the surface opposite to the emulsion layer) of the recording paper sheet 30. In the exposure unit 16, the recording paper sheet 30 is sequentially conveyed by a pair of transfer rollers 35 and 36, a pair of feed rollers 33, and a pair of feed rollers 34. The exposure unit 16 is provided with an exposure device 32 including a known laser printer and an image memory. The exposure device 32 irradiates the recording paper sheet 30 passing between the feed roller pair 33 and the feed roller pair 34 with a laser beam whose intensity is modulated based on the image data stored in the image memory. Do. The exposed recording paper sheet 30 is placed on the belt conveyor 3.
7 The recording paper sheet 30 is used for the belt conveyor 3.
When the paper is conveyed on the paper 7, the paper is sorted into a plurality of rows by the paper sorting unit 17 and sent to the developing device 20.

The developing apparatus 20 includes a developing tank 40, a fixing tank 41, and a first to fourth cleaning tanks 4 which are sequentially arranged adjacent to each other.
2, 43, 44, and 45, each of which is filled with a developing solution, a fixing solution, and a cleaning solution. Each tank 40-45
Is provided with a heater and a temperature sensor (not shown), and performs temperature control so that the liquid temperature becomes constant. The recording paper sheet 30 is placed in each tank 4 along a transport path 46 shown by a broken line in the figure.
Each process of color development, fixing, and washing is performed while passing through the inside of 0 to 45.

The squeezing device 21 is composed of a pair of nip rollers arranged so as to sandwich the transport path 46. When the recording paper sheet 30 is held between the nip rollers, the cleaning liquid attached to the surface is squeezed out. Then, the squeezed cleaning liquid is returned to the fourth cleaning tank 45.

The drying unit 22 is provided with a heater unit, a blower, and the like, and sends high-temperature drying air to the exposure surface of the recording sheet 30. Thereby, the recording paper sheet 30 that has passed through the squeezing device 21 is subjected to a drying process. The recording paper sheet 30 that has passed through the drying device 22 is collected at one location for each print command by the stacking device 23, distributed by a distribution device (not shown), and sent out of the processor.

FIG. 2 shows a transport mechanism related to the exposure unit 16. The transport mechanism includes a delivery roller pair 35,
36, a pair of feed rollers 33, and a pair of feed rollers 3
4 and a belt conveyor 37. Note that each of the rollers constituting the feed roller pair 33 and the feed roller pair 34 has a shape having a large number of roll bodies divided by a circumferential groove as shown in FIG. Are shown as one roll in order to avoid complication of the drawing.

The transfer roller pairs 35 and 36 are connected to the guide plate 4.
7, capstan rollers 50, 5 arranged vertically
1 and nip rollers 52 and 53. Driven gears 54 and 55 are attached to one ends of the capstan rollers 50 and 51, and rotate by receiving driving force from a motor (not shown). A well-known one-way clutch is mounted inside the driven gears 54 and 55. Recording paper sheet 3
When 0 is nipped by the feed roller pair 33, the one-way clutch is operated, and the capstan rollers 50, 51 are actuated.
Turns into a free roller. Therefore, the delivery roller pair 3
5 and 36 rotate at the same speed as the feed speed by the feed roller pair 33.

The feed roller pair 33 and the feed roller pair 34 are respectively composed of capstan rollers 60 and 61 arranged vertically above and below a guide plate 47 and nip rollers 62 and 63 which are driven rollers. The feed motor 64 is connected to the capstan roller 60 on the feed roller pair 33 side via a gear train (not shown). As the feed motor 64, for example, a five-phase pulse motor having 100 rotor teeth is used.

Although shown only in FIG. 5 to avoid complication of the drawing, a tensioner shaft 68 is disposed between the nip rollers 62 and 63, and the tensioner shaft 68 and the capstan rollers 60 and 61 , A steel belt 65 that is not stretched is stretched. Therefore, the two capstan rollers 60 and 61 rotate at a constant speed by the single feed motor 64.

When the recording paper sheet 30 is sandwiched between the capstan rollers 60, 61 and the nip rollers 62, 63, the silicone rubber (see FIG. 3) covering the outer peripheral portions of the rollers 60 to 63 is pressed and deformed. Here, when the thickness of the recording paper sheet 30 is larger than the reference value, the force for nipping the recording paper sheet 30 by the nip rollers 62 and 63 increases, so that the nip pressure increases and the deformation amount of the silicone rubber decreases. growing. If the length of the recording paper sheet 30 in the width direction is shorter than the reference value, the area where the nip rollers 62 and 63 come into contact with the recording paper sheet 30 becomes small, so that the nip pressure increases and the silicone rubber is deformed. The amount increases.
As described in FIG. 9, when the deformation amount of the silicone rubber increases, the conveyance speed of the recording paper sheet 30 by the capstan rollers 60 and 61 increases.

For this purpose, a controller 67 is connected to the feed motor 64 via a driver 66. The controller 67 includes capstan rollers 60 and 61
It is used as a means to adjust the rotation speed of
U70 and memory 71 are provided. The CPU 70 is connected to a type input unit 72 for inputting the type of the recording sheet 30. Further, the memory 71 stores the type of the recording paper sheet 30 and the value of the pulse rate according to the thickness and width of the recording paper sheet 30.

For a recording sheet thicker than a reference recording paper sheet, the pulse rate value is lower than the reference value. Further, when the paper width is wider than the reference recording paper sheet, the value of the pulse rate is higher than the reference value. By changing the pulse rate applied to the feed motor 64, the rotation speed of the capstan rollers 60, 61 fluctuates, so that a speed difference due to a difference in width or thickness of the recording sheet can be suppressed. Thereby, the recording paper sheet 30 can be conveyed at a constant speed regardless of the type.

Before performing the printing operation, the operator operates the type input section 72 to input the type information of the recording sheet 30. This type information is sent to the CPU 70 in the controller 67 at the time of printing. The CPU 70 stores the value of the pulse rate corresponding to the input type information in the memory 71.
Read from Then, the feeding motor 64 is driven based on the read pulse rate.

The width of the recording paper sheet is 89 mm,
2mm, 127mm, 152mm, 165mm, 203
mm, 210 mm, and the thickness is 170 μm, 24
When the recording paper sheet 30 is changed to 0 μm, the conveyance speed of the recording paper sheet 30 becomes the reference recording paper sheet (width 254 mm, thickness 20 mm).
For a transport speed of 5 μm), a difference of up to about 0.2% occurs. For this reason, it is preferable to change the pulse rate so that the difference in the conveyance speed of the recording paper sheet 30 is 0.1% or less.

When the feed motor 64 is driven to rotate the capstan rollers 60, 61, the nip rollers 62, 6
3 is conveyed at a constant speed in the direction of the arrow (sub-scanning direction) in the figure. Then, when the recording paper sheet 30 passes through the exposure position 73 (see FIG. 5), the exposure device 32 irradiates the laser light oscillated in the main scanning direction to perform exposure. Delivery roller pair 34
Is passed on the belt conveyor 37 and sent to the developing device 20.

FIG. 3 shows the appearance of the capstan rollers 60 and 61 and the recording paper guide 74. The capstan rollers 60 and 61 are made of metal shaft portions 60a and 61.
a, silicone rubber 60b covering the periphery of the shaft,
61b. Silicon rubber 60b, 61b
Of the peripheral grooves 60c, 6 spaced apart in the axial direction.
1c, the outer circumferential surface of the roller is formed by a number of roll bodies 60d, 61d by the circumferential grooves 60c, 61c.
Is divided into

A recording paper guide 74 is disposed between the capstan rollers 60 and 61. Recording paper guide 74
Has a T-shaped vertical section, an upper portion serving as a horizontal guide plate 74a, and a lower portion serving as a vertical mounting plate 74b. As shown in FIG. 4, the recording paper guide 74 is mounted such that the upper surface of the guide plate 74a is slightly lower than the tops of the capstan rollers 60 and 61. When the recording paper sheet 30 is nipped and conveyed, the capstan rollers 60 and 61 are deformed,
Since the recording paper sheet 30 has substantially the same height as the upper surface of the guide plate 74a, the recording paper sheet 30 can be transported smoothly.

A plurality of comb-shaped guide projections 74c and 74d are integrally formed on both sides of the guide plate 74a. The guide projections 74c and 74d enter the circumferential grooves 60c and 61c of the capstan rollers 60 and 61, respectively. Further, an inclined guide surface is formed along the bottom surface of the circumferential groove 60c, 61c at the tip of the guide protrusion 74c, 74d, so that the recording paper sheet 30 can be smoothly transferred to the capstan rollers 60, 61. Will be

In FIG. 2, nip rollers 62, 63
Are rotatably held by brackets 75 and 76 at both ends. The brackets 75 and 76 are guided by a guide plate (not shown) so as to be able to move up and down.
9 (see FIG. 5) is attached. This compression spring 88,
By the bias of 89, the nip rollers 62, 63 are pressed against the capstan rollers 60, 61. Engagement slots 75a, 76a are formed in the brackets 75, 76, and guide pins 77 are inserted through the engagement slots 75a, 76a.
Drive levers 77 and 78 are connected via a and 78a.

The driving levers 77 and 78 are attached to a mounting shaft 80.
Are attached so as to be rotatable so as to cross each other. Guide pins 77 are provided at one end sides of the drive levers 77 and 78.
a, 78a are provided, and cam followers 81, 82 attached to the other end side are in sliding contact with the curved surface of the eccentric cam 83.

As shown in FIGS. 5 to 8, the eccentric cam 83
Is rotated about a shaft 85 by a motor 84. When the eccentric cam 83 rotates, the other ends of the drive levers 77 and 78 are pushed out, and the drive levers 77 and 78 are attached to the mounting shaft 8.
It rotates around 0. Then, the nip rollers 62,
Numeral 63 moves to the release position where the holding of the recording paper sheet 30 is released, or moves from the release position to the holding position.
As a result, the feed roller pair 33 and the feed roller pair 34 are selectively brought into the nip release state. Position sensors 86 and 87 for detecting passage of the recording paper sheet 30 are disposed in front of the nip rollers 62 and 63.

As shown in FIG. 5, when the recording paper sheet 30 is not being conveyed, the eccentric cam 83 pushes out the other end of the drive levers 77 and 78, and the nip roller 6
2 and 63 are both held at the retracted position.

When the conveyance of the recording paper sheet 30 is started, the eccentric cam 83 rotates clockwise in the figure from the state shown in FIG. 5 to the state shown in FIG. As a result, the front drive lever 77 rotates counterclockwise in the drawing, and the front nip roller 6 rotates.
2 descends to the clamping position. In this state, the recording paper sheet 3
0 is sent to the recording position 73 by the sending roller pair.

When the leading end of the recording sheet 30 passes the position sensor 87 on the rear stage, the eccentric cam 83 rotates clockwise from the position shown in FIG. 6 to the position shown in FIG. Only 78 is rotated. The rear nip roller 63 moves to the nipping position while the front nip roller 62 is held at the nipping position. Then, after the leading end of the recording paper sheet 30 has passed through the feed roller pair 34, the nip roller 63 reaches the nipping position, and the recording paper sheet 30 is nipped by the feed roller pair 33 and the feed roller pair 34. Since the value of the pulse rate applied to the feed motor 64 is changed according to the type of the recording paper sheet 30, the transport speed is always constant even when recording paper sheets having different widths and thicknesses are transported.

When the rear end of the recording paper sheet 30 passes through the front position sensor 86, the eccentric cam 83 rotates from the position shown in FIG. 7 to the position shown in FIG.
Only rotate. While the nip roller 63 on the rear side is held at the holding position, the nip roller 62 on the front side starts moving to the retracted position. Thereby, the recording paper sheet 3
Before the rear end of 0 passes through the feed roller pair 33, the holding by the feed roller pair 33 is released.

When the trailing end of the recording paper sheet 30 passes between the feed roller pair 34 after the exposure is completed, the eccentric cam 8
3 rotates from the state shown in FIG. 8 to the state shown in FIG.
When the next recording paper sheet 30 is sent, the eccentric cam 83
Moves the nip rollers 62, 63 forward and backward by the same operation as described above, and conveys the recording paper sheet 30.

In the above-described embodiment, the speed control according to the change in the nip pressure is performed by reading the value of the pulse rate according to the type of the recording paper sheet 30. Memory 7 as the correction amount for
1, and speed control may be performed using this correction length. When the speed of the capstan rollers 60 and 61 can be finely adjusted, a DC servo motor may be used as the feed motor 64 in addition to the pulse motor.

In the above embodiment, an example in which the recording paper sheet 30 is exposed has been described. However, the present invention may be implemented in another recording method. For example, the exposure device 32
Instead of this, the present invention may be applied to a printer having an ink jet head, and in this case, accurate printing can be performed while suppressing fluctuations in the conveyance speed of the recording sheet. In the above-described embodiment, an example in which image recording is performed has been described. However, the present invention is not limited to this, and may be implemented as a sub-scanning conveyance unit in an image reading device.

[0041]

As described above, according to the present invention,
When the recording material is pinched and conveyed by a pair of conveying rollers coated with an elastic body, the rotation speed of the conveying roller pair is adjusted according to the thickness and width of the recording material. Can be suppressed. Thereby, regardless of the type of the recording material, the transport speed is always constant, so that the fluctuation of the recording density can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a printer processor.

FIG. 2 is a perspective view illustrating a recording paper sheet conveyance system according to an exposure unit.

FIG. 3 is a perspective view of a capstan roller and a recording paper guide.

FIG. 4 is a longitudinal sectional view of a capstan roller and a recording paper guide.

FIG. 5 is a side view of the recording paper sheet conveyance system showing a state before the conveyance of the recording paper sheet is performed.

FIG. 6 is a side view of the recording paper sheet conveying system showing a state after a leading end of the recording paper sheet has passed a rear position sensor.

FIG. 7 is a side view of the recording paper sheet conveying system showing a state where the leading end of the recording paper sheet has passed through a pair of feed rollers.

FIG. 8 is a side view of the recording paper sheet conveyance system showing a state after a rear end of the recording paper sheet has passed a front position sensor.

FIGS. 9A and 9B are schematic diagrams showing how a capstan roller is deformed when a recording sheet is nipped, wherein FIG. 9A shows a case where the amount of deformation is small, and FIG. 9B shows a case where the amount of deformation is large.

[Explanation of symbols]

 Reference Signs List 10 printer processor 16 exposure unit 30, 100, 103 recording paper sheet 33 feed roller pair 34 feed roller pair 50, 51, 60, 61, 101 capstan roller 52, 53, 62, 63, 102 nip roller 64 feed motor 67 controller 71 memory

Claims (7)

[Claims] 1. An image forming apparatus comprising: a roller that constitutes a pair of conveying rollers that sandwich and convey a sheet-like recording material; and an elastic body that covers the rollers, and reduces the rotation speed of the conveying roller pair as the recording material becomes thicker. A method of conveying a sheet-shaped recording material, which is a feature. 2. A roller constituting a pair of conveying rollers for sandwiching and conveying a sheet-like recording material is covered with an elastic body, and the rotation speed of the pair of conveying rollers is reduced as the recording material becomes shorter in the width direction. A method for conveying a sheet-shaped recording material. 3. A conveyance roller pair for nipping and conveying a sheet-like recording material, an elastic body covering each roller constituting the conveyance roller pair, and the conveyance as the recording material becomes thicker. And a drive control means for controlling the operation so that the rotation speed of the roller pair is reduced. 4. At least one pair of transport rollers for nipping and transporting a sheet-like recording material, an elastic body covering each of the rollers constituting the transport roller pair, and as the recording material becomes shorter in the width direction. And a drive control means for controlling the operation so that the rotation speed of the pair of conveying rollers is reduced. 5. The drive control means includes a storage device in which rotation speed information determined according to a thickness and a width of the recording material is stored, and a rotation device according to a type of the recording material being conveyed. 5. The sheet-shaped recording material conveying apparatus according to claim 3, wherein speed information is read from the storage device to adjust a rotation speed of the conveying roller pair. 6. The transport roller pair includes a feed roller pair that transports the recording material to an exposure position that irradiates recording light, and a feed roller pair that transports the exposed recording material to a developing device. The sheet conveying device according to any one of claims 3 to 5, wherein: 7. The apparatus according to claim 3, wherein each of the rollers constituting the pair of conveying rollers is a skewed roller.