JPH0480140A - Feeding device for image forming apparatus - Google Patents

Abstract

NEW MATERIAL:To prevent a diagonal feed without providing a resist means by setting the transfer speed from close to an image forming part to close to a fixing means to be always constant, and setting the speed changeable close to a containing means. CONSTITUTION:A transfer means 53 feeds and transfers a recording medium 77 without producing diagonal feed or jam by changing its speed close to a containing means 52 for supplying the recording medium 77 to set the relative speed to the recording medium 77 which is put statically at almost zero. The transfer means 53 makes a transfer motion at a constant speed constantly close to an image information holding body 31 and a fizing means 38. Expansion/contraction of an image or disturbance of the image at the time of transfer, disturbance of the image at the time of fixing, etc., are thus prevented. The transfer means 53 achieves a secure resist function without providing any special resist means by sucking the recording medium with the relative speed zero.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording medium feeding device in an image forming apparatus such as a copying machine, a laser printer, or a facsimile machine.

[Prior art]

In image forming apparatuses such as copying machines, it is known that a sheet-like recording medium such as a transfer paper fed by the friction of a rubber roller is conveyed by a pair of rubber rollers or a belt to an image forming position such as a transfer value of 1 on a photoreceptor. It is being

In such conventional recording medium feeding and conveying devices, in order to prevent multiple sheets of recording media from being fed overlappingly, a friction pad is combined with the rubber feeding roller, and a rubber reverse is used to reverse the rotation. It is common practice to combine rollers, and to provide corner claws on the cassette that houses the recording medium.

However, the conventional recording system has problems such as jamming and skewing during conveyance, and in addition to double feeding, conventional apparatuses still have problems with the reliability of feeding and conveyance.

Furthermore, the structure becomes more complex and the control becomes more complicated.
It is also costly, and the problems of simplifying the device and reducing costs remain unsolved.

In order to solve these conventional problems, an insulating endless heald is placed over almost all the conveyance systems in the copying machine, and the heald is charged with a charging device, and the paper stored in the paper feed tray is charged by the heald. The paper is sent out by a paper feed roller installed coaxially with the support roll and electrostatically attracted to the rear belt, or the heald is brought into direct contact with the paper and electrostatically adsorbed and fed, and at the same time it contacts the photoreceptor. For example, Japanese Patent Laid-Open No. 59-212856 discloses that conveyance by a heddle to a transfer area to be transferred is carried out using a heald.
No., JP-A-59-224858, JP-A-59-229
This method has been proposed in Publication No. 585 and the like.

However, in these conventional technologies, when feeding the paper stored in the paper feed tray using a paper feed roller provided coaxially with the drive shaft of the insulated endless heddle, the roller feeds the paper through frictional contact, so the paper is not tilted. line occurred. Also, when double feeding occurs, the first sheet (upper side) is electrostatically attracted to the heddle and transported, but the second and subsequent sheets (lower side) that are double fed to the first sheet are It protrudes from the tip of the paper feed tray, causing a jam during the next feeding operation.

Furthermore, paper dust is generated due to frictional contact, resulting in poor paper feeding and poor image quality during image formation.

When paper stored in a paper feed tray is directly fed by an electrically charged insulating endless heddle, the heald comes into contact with the paper in the rotating state during normal image formation, so it is difficult to tension the heald or lower the knee. The status and paper loading status (loading status)
Unless uniformity is achieved with considerable precision, the state of contact between the heddle and the paper becomes unstable, and skewed feeding of the paper is likely to occur.

Here, in order to stabilize the contact state between the belt and the paper, it is necessary to arrange both the heald and the paper within the apparatus with high precision.

Also, there is a certain amount of friction between the first sheet of paper (upper side) and the second sheet of paper (lower side) because the heald and roller contact the first sheet of paper in a rotating state. There was a risk of force being generated and double feeding occurring.

Further, although the paper is not separated by friction, the rotating belt comes into contact with the paper, so a frictional force is generated and a considerable amount of paper dust is generated.

Note that even if rollers or healds are used as paper feeding means, the state of paper being ejected from the paper feed tray is not always constant and reliable as described above, so the leading edge of the paper and the leading edge of the image to be copied on the paper may differ. It is necessary to provide a registration means for adjusting the Ifffl position and correcting the skew of the paper.
Control was still complicated.

Also, the paper feed section, registration section, transfer section, fixing section, and paper ejection section of the copying machine are connected in this order with one endless heald, and the endless heald is first attached to the copy paper held in the copy paper feed section. For example, Japanese Patent Application Laid-Open No. 139846/1984 proposes that the copy paper be brought into pressure contact with the copy paper, and then carried out by frictional force from the copy paper feed section, and then conveyed to an image forming area after being renosted. However, with this conventional technology, when the heddle feeds out the paper stored in the copy paper feed section (paper feed tray), the roller separates and feeds the paper through frictional contact, resulting in skew or double feeding of the paper. Furthermore, paper dust is generated due to the frictional contact, resulting in poor paper feeding and poor image quality during image formation. Furthermore, since the state of paper feeding from the paper feed tray is not always constant and reliable, it is necessary to provide a registration means for adjusting the position W between the leading edge of the paper and the leading edge of the image to be copied on the paper and correcting the skew of the paper. However, the structure and control were still complex.

[Problem to be solved by the invention]

The present invention solves the above-mentioned conventional problems, enables feeding from a storage means without requiring a registration means, without causing skew feeding or double feeding, and prevents jams occurring during conveyance. Another object of the present invention is to provide a feeding device for an image forming apparatus that can transport images while preventing image disturbances in an image forming section and a fixing section.

[Means for Solving the Problems] The present invention solves the above problems in an image forming apparatus in which a recording medium fed from a storage means is transferred in an image forming section by an image information holding means and fixed in a fixing device. The means for suctioning and conveying the recording medium is an endless conveying means, and the endless conveying means is formed to be able to convey the recording medium from the storage means to the fixing device via the image forming section, and the endless conveying means is configured to convey the recording medium from the vicinity of the image forming section to the fixing device. The problem has been solved by a feeding device for an image forming apparatus, which is characterized in that the conveyance speed to the vicinity is always constant and the speed is variable in the vicinity of the storage means.

[Function] According to the present invention, the endless conveyance means carries out conveyance movement at a constant speed, and at this time, only a part of the endless conveyance means is additionally moved in the horizontal direction, in the vertical direction, or in the horizontal and vertical directions at the same time. , by selecting its speed of movement, the endless transport means locally slows down or stops relative to the stationary member, for example the recording medium, or moves in the opposite direction.

When the recording medium is brought into contact with the recording medium at a relative speed of zero, it becomes possible to feed the recording medium in its contained state. At this time, no relative deviation occurs between the endless conveyance means and the recording medium.

By forming an alternating electric field pattern on the conveyance means and configuring it to attract the recording medium, the conveyance means attracts only the topmost recording medium it comes into contact with, and does not attract the second and subsequent recording media. Double feeding was prevented because no adsorption force was applied.

When the moving conditions of the recording medium, such as the speed, change in the image forming area, the image formed on the recording medium expands and contracts, causing image disturbance. Further, if the conditions for moving the recording medium in the vicinity of the fixing area by the fixing device fluctuate, the conveyance of the recording medium in the fixing area becomes unstable, resulting in image disturbance during fixing, bending of the recording medium, jamming, etc.

According to the present invention, the conveying means changes the speed so that the relative speed with respect to the stationary recording medium becomes almost zero in the vicinity of the storage means for feeding the recording medium, thereby preventing skew or jamming. The conveying means always moves at a constant speed in the vicinity of the image information holding body and the fixing device. Therefore, image expansion/contraction and image disturbance during transfer, image disturbance during fixing, etc. are prevented. By suctioning the recording medium at a relative speed of zero, the conveying means achieved a reliable registration function without providing a special registration device.

〔Example] The details of the present invention will be explained based on embodiments shown in the drawings.

In FIG. 1, a copying machine 1 as an example of an image forming apparatus according to the present invention includes a scanner device W2 for reading an image of a document;
The copying main body 3 has a built-in image forming section that forms an image based on information from the scanner device, and a paper bank device 4 that stores a large number of recording media for recording images, such as recording paper. The scanner device 2 is placed on the bank device 3, and the scanner device 2 is placed on the copying main body 3.

The copying main body 3 has an image forming section 5 and a paper feeding device 6 in FIG.

The scanner shaft W2 placed on the copying body 3 may be configured as an integral structure, as opposed to the example in which it is formed as a side structure separate from the copying body 3, as shown in FIGS. You can also do it.

The scanner device 2 includes a contact glass 1 on which a document is placed.
1, a document holder 2 for pressing and fixing an original onto a contact glass 1, and an optical device. The optical device includes a lamp 13 that illuminates and scans an original on a contact glass; a first mirror 14 that scans together with the lamp 13 and reflects light reflected from the original; and a first mirror 14 that scans the original on a contact glass; It has a second mirror 15, a third mirror 16 that sequentially reflects light, and a lens 17 that images the reflected light from the third mirror 16 onto the CCD 18. The second mirror 15 and the third mirror 16 are scanned at half the reading scanning speed of the lamp 13 .

The image forming section 5 built into the copying body 3 includes a writing optical device 7 . In FIGS. 2 and 4, the writing optical device 7 includes a semiconductor laser 2J, a collimating lens 22 that converts the laser beam emitted by the semiconductor laser 21 into a parallel light beam, and an aperture 23 that shapes the light beam into a light beam of a certain shape. and a cylinder lens 24 which makes the shaped beam from the averte + 23 enter the polygon mirror 25 in a compressed form in the sub-scanning direction. A polygon mirror 25 having an accurate polygonal shape is rotated in a constant direction at a constant speed by a polygon motor 261, and the incident laser beam is deflected by the rotation of the polygon mirror 25, and the deflected laser beam is passed through fθ lenses 27a, 27b, 27c. The rotation speed of the polygon mirror 250 is determined by the speed of the image information holding stage 31 of the image forming section 5, for example, the photoreceptor 31, and the writing density of the number of two surfaces.

The fθ lenses 27a, 27b, and 27c convert the scanning light with a constant angular velocity so that it scans the photoconductor 3 at a constant speed, forms an image on the photoconductor 31 so that it becomes the minimum light spot, and further tilts the surface of the photoconductor 31. It has a correction function.

The light after passing through the fθ lens 27 (27a, 27b, 27c) is reflected by the mirror 2B, and the light outside the image area is guided by the synchronization detection mirror 29 to the synchronization detection sensor 3°, which outputs a cueing signal in the main scanning direction. Emit a synchronization signal. One line of image data is output based on the image information read by the scanner device 2 after a certain period of time after the synchronization signal is output from the synchronization detection sensor 3o. The light as image data is mirror 28
The light is reflected by the beam and forms an image on the photoreceptor 31 at the exposure position. By repeating this process, images are sequentially exposed onto the photoreceptor 31.

The photoreceptor 31 has a drum shape and has a photosensitive layer coated on its surface. Organic photoconductor (OPC), a-3, is used as a photoconductor sensitive to the wavelength of semiconductor laser 780 nm.
i, 5e-Te, etc. are known, but in this example an organic photoreceptor is used.

Generally, in the case of laser writing, the light is applied to the image area.
P (negative/positive) process and P that shines light on the skin
There is a /P (positive-positive) process, and in this example, N
, /P process.

The charger 32 uses a scorotron system having a grid on the photoreceptor side to uniformly (-) charge the surface of the photoreceptor 310.
A laser beam is applied to the photosensitive area to lower the potential. As a result, -750 to -800V is applied to the background part of the surface of the photoreceptor 31.
An electrostatic latent image of 50 Vlfff degree is formed in the image area b knee. The electrostatic latent image is transferred to the developing roller 33a by the developing device 33.
With a bias voltage of 00 to -600V applied, (
The toner charged to =) is developed and visualized.

The image visualized by the developing device 33 is transferred from the back side of the conveyance heald 53 onto a recording medium, such as a recording paper surface F such as transfer paper, which is sent in synchronization with the photoreceptor 31 by the conveyance heald 53 of the paper feed bag W6. Charge +34 (+n charge is applied and transferred.

Toner remaining on the photoreceptor without being transferred to the recording paper is scraped off from the photoreceptor 31 by the cleaning device 35 and collected in a tank within the cleaning device 35. Furthermore, the potential pattern remaining on the photoreceptor 3I is erased by applying light from the static elimination run 136.

The reflection density on the surface of the photoreceptor is measured by a photosensor 37 provided at a position immediately after the development is performed by the developer 33. The photosensor 37 consists of a combination of a light receiving element and a light emitting element. To measure the reflection density, write a certain pattern (for example, a pure black or halftone dot pattern) using the writing optical device 7 at a position corresponding to the photosensor reading position, and then develop the reflectance of the pattern area and the exposure of the area other than the pattern area. It determines the density of the image based on the ratio of body reflectance, and if it is too light, it issues a toner replenishment signal. Furthermore, it is also possible to detect an insufficient amount of toner remaining by utilizing the fact that the density does not increase even after replenishment.

The recording paper on which the image has been transferred is separated by curvature by a drive roller 54 wrapped around a conveyor belt 53, and sent to a fixing device on the third day. The fixing device 38 includes a heat roller 39 and a pressure roller 4o.
The toner on the surface of the recording paper is fixed by a pair of fixing rollers. After fixing, the recording paper is guided to a paper discharge path 42 by a claw 41 and discharged by a paper discharge roller 43 during normal image formation, for example, copying.

The paper feed device 6 has a conveyance device 51 and a storage means, such as a paper feed tray or a paper feed cassette.

The conveying device 51 has an endless conveying means, for example, an endless circulation running conveyor heald 53, and the conveyor heald 53 includes a driving roller 54, a first driven roller 55, and a second driven roller 5.
6 and adjustment roller 57 in sequence. The transport heald 53 is transported at a substantially constant speed by a drive roller 54. The conveyance heald 53 has a predetermined nip width between the drive roller 54 and the first driven roller 55, where the photoreceptor 3 contacts from the outside at an image forming position, for example, at a transfer position. A transfer charger 34 facing the photoreceptor 31 is arranged facing the inner surface of the transport heald 53.

Between the first driven roller 55 and the second driven roller 56,
An appropriate number of pick-up rollers 58, for example, two pickup rollers 58, are arranged at appropriate intervals inside the conveyance heald 53, and each pickup roller 58 is formed to be movable up and down. The interval between the pink up rollers 58 can be changed as needed by moving one or more pink up rollers.

The first driven roller 55 and the adjustment roller 57 are formed to be movable in a substantially horizontal direction, and the adjustment roller 57 is formed so as to receive the tension of a spring 59 so that a predetermined tension can always be applied to the conveyance heald 53.

As shown in FIGS. 5 and 6, the first driven roller 55 has shaft portions 55a at both ends rotatably supported by bearings 60, and the bearings 60 are slidable on a guide shaft 62 fixed to a side plate 61. It is formed as a supported slider. The shaft portion 55a may be fixed to a bearing 60, and the first driven roller 55 may be rotatably supported by the shaft portion 55a. The first driven roller 55, that is, the bearing 60, is reciprocated along the guide shaft 62 by a moving device 63. The moving device 63 additionally moves the conveying heald 53 in addition to the conveying movement by the drive roller 54, and is used as a feeding speed change device. The moving device 63 includes a drive shaft 64 rotatably supported by the side plate 61.
a drive pulley 65 fixed to the drive pulley 65 and a driven boot IJ67 fixed to the driven shaft 66 rotatably supported by the side plate 61.
The drive shaft 64 is rotationally driven by a movement motor 68. A drive heald 69 is wound around each drive pulley 65 and driven pulley 67, and the drive heald 69 is attached to the slider 6.
0 by a fixing plate 70. The drive heald 69 is moved forward and backward by the forward and reverse rotation of the moving motor 6B, and the slider 6
0 along the guide shaft 62, the first driven roller 55 is moved substantially horizontally.

When the first driven roller 55 is at the home position, which is the right end position of the rotation, it is detected by the home sensor 71. The adjusting roller 57 is also moved in accordance with the movement of the first driven roller 55, and is configured so that the conveying heald 53 can be maintained at a constant tension.

Therefore, the adjustment roller generally moves in the opposite direction to the first driven roller by a distance equal to the distance traveled by the first driven roller.

The moving speed V mm/s of the first driven roller 55 is the conveying speed of the conveying belt 53, that is, the circumferential speed v ym/s.
s is 172, that is, V = v/2, when the first driven roller 55 moves to the left side in the figure, the conveyance heald 53 traveling in the direction of the arrow moves from the adjustment roller 57 to the second driven roller 56 to the first driven roller. In the section leading to cola 55, that is, the speed fluctuation region, the circumferential velocity v wa / s
By the action of the moving speed V an /s, the upper conveyance heald 53 is apparently shifted to a stopped state and can be maintained in a stopped state. If the recording paper is sucked from the paper feed tray 52 during the stopped state in which the feeding speed indicated by the apparent speed above is zero, it becomes possible to feed the paper without using a registration device and without shifting the leading edge registration. In addition, the suction position is always the same, and there is no deviation due to belt conveyance, and there is no need for a registration stop operation by a specially provided registration device for image positioning. This means that it is only necessary to control the paper feeding timing and the image formation start timing.

In the speed fluctuation region that is a part of the conveyance heald 53 due to the movement of the first driven roller 55, a speed change operation is performed in which it appears to stop at the top and then returns to a predetermined speed. The driving roller 5 exits and passes through the transfer position.
4 to the adjustment roller 57, that is, in the constant speed region, the conveyor belt 53 does not appear to undergo any apparent speed fluctuations and moves at a constant speed. Therefore, the circumferential speed of the conveyor belt 53 remains unchanged while the recording paper is being transported to the transfer position and to the fixing position by the fixing device 38. This means that a part of the conveyance heald 53 appears to be in a stopped state with an upward speed change, and even while paper feeding is being performed, another recording paper is conveyed by the same conveyance belt 53, and transfer, separation, and fixing are performed. This can be done without stopping the effects of If the conveyance heald 53 is cleaned in a constant speed region in which it always travels at a constant speed, for example using a heald cleaner 72 provided below the drive roller 54, cleaning defects will not occur.

When the conveyance belt 53 attracts the recording paper from the paper feed tray 52, the first driven roller 55 is moved to the right side in the figure and returned to the home position. At this time, the adjustment roller 57 is also moved.

When the first driven roller 55 returns to the home position,
The apparent speed in the speed variation region of the conveyance heald 55 increases to the upper speed, that is, the feeding speed increases to twice the speed in the constant speed region.

An upper presser roller 73 is arranged above the first driven roller 55 in FIG. 2, a lower presser roller 74 is arranged on the lower right side of the first driven roller 55 in FIG. A guide plate 75 is provided between the lower pressing rollers 74 and assists the conveyance so that the recording paper conveyed from the paper feed tray 52 by the conveyance heald 53 can smoothly change direction along the first driven roller 55. do.

After the conveyor belt 53 is cleaned of dirt by a heald cleaner 72, a certain charge pattern is formed on the conveyor heald 53 by a charging roller 76 disposed near the heald cleaner 72. As in the case where the charging roller 76 is disposed in circumferential contact with the second driven roller, when a charge pattern is formed in the speed fluctuation range w4 of the conveyance belt 53, the change in the feeding speed of the conveyance heald 53 By performing control such as changing the frequency of the applied charges, a fixed charge pattern can be formed on the E of the transport heald 53.

The paper feed tray 52 is a front-loading type recording paper stacking device, and the paper feed tray 52 is pulled out from the front of the copying machine 1, recording paper 77 is set therein, and the paper supply tray 52 is pushed into the copying machine 1. Recording paper can be replenished.

The paper feed tray 52 has a size series of recording paper (for example, A series,
B series - letter size, etc.). Although the A series will be explained here, the same applies to other series.

A center fence 78 is provided at the center of the paper feed tray 52, and a right fence 79 is provided on the right side, and the center fence 78 is collapsible as shown in FIG.

When setting A4 size recording paper, use the center fence 7B.
Stand it up as shown in Figure 7, put it into the two tray chambers 80 and 81 formed on the left and right, respectively, and leave the space between 1 and 1 open.
The recording paper is placed inside the two tray chambers.

On the lower side of the paper feed tray 52, a rising tray 8 is provided in each of tray chambers 80 and 81 formed on the left and right sides of the central fence 7.
2 is provided.

When the central fence 78 is erected, the tray consisting of the tray chamber 80 and the rising tray 82 on the right side in FIG.
2 is called a second tray 52''.

As shown in FIGS. 7 to 9, the central fence 78 has an upper face guide 83 and a lower face guide 84, and corner guides 85 are provided at both ends of the upper face guide 83 and at both ends of the lower face guide 84, respectively. This prevents the recording paper 77 from shifting laterally.

The upper face guide 83 is vertically slidably inserted into the groove of the lower face guide 84, and the spring 86 is inserted into the groove of the lower face guide 84.
3 and the lower face guide 84. A groove is formed in the improved face guide 84 to improve the lower face guide 84.
can be inserted. Due to the action of the spring 86, the upper face guide 83 is maintained at a predetermined relative position with respect to the lower face guide 81 when no load is applied.

A notch 87 is provided at the center of the upper edge of the upper face guide 83.
is formed so that the operator's hand does not touch the recording paper 77 when it is inserted.

The lower face guide 84 is connected to the paper feed tray 52 by a support shaft 88.
It is rotatably supported by the frame. Lower face guide 84
It has an L-shaped finger portion 89 at its lower end. When the finger section 89 is engaged with a protruding engagement section 90 formed on the frame section 52a of the paper feed tray 52, the lower face guide 84 is stopped in a substantially vertical position when it is rotated and stands up. , and is prevented from rotating any further. Finger part 89
A claw 89a is formed on the lower face guide 84, and by engaging with a hook 91 formed on the frame portion 52a, the lower face guide 84 is prevented from rotating in the falling direction and is held in the upright position. nail 89
When the upper face guide 83 is pushed sideways with enough force to cause the hook part 91 to be disengaged from the elastic deformation G, the center fence 78
8 rotates clockwise at I and s in the figure and falls over, opening the space between the right tray chamber 80 and the left tray chamber 81 as shown in FIG. The face guide 83 and the lower face guide 84 are buried in the recess 92 formed in the frame 52a of the paper feed tray 52 so that they do not interfere with the recording paper placed on the tray 82. It is formed to The claw 8 of the fallen lower face guide 84 shows that the center fence 78 has fallen and the right tray chamber 80 and left tray chamber 81 are passing through.
9a detects the paper size by pressing a switch 93 as a paper size sensor.

A benomer end sensor 94 is mounted on the upper surface of the rising tray 82.
is provided to detect the presence or absence of recording paper.

The central fence 78 can also be of a removable type instead of the collapsible structure 03 shown in the figure. Size detection at this time can be performed by providing a sensor that detects the presence or absence of the central fence 78.

The right fence 79 can also be formed by the lower face guide 84 and the upper face guide 83 as shown in the ninth example. In this case, there is no need to overturn the right fence -7 (+).

The recording paper 77 in the paper feed tray 52 is transferred to the transport heald 53.
The big 7/-"low-758" that presses against 1 and 7
One of the above is the construction/chair guide 83 above the intermediate fence 78.
Similarly, another one is placed directly above the upper face guide 83 of the right fence 79.

As shown in FIG. 10, one pickup row +58 and the other one are placed directly above each face guide 83.
One or more Pinocqua tuberos → 58 are rotatably supported, for example, on a carrier plate 95 as a set. In the example shown, 2
The pick-up rollers 58 are supported as one piece on the carrier plate 95. Each set of pickup rows 7758 is supported at the same height.

The carrier plate 95 is always pulled up to a fixed position by a tension spring 96, and the conveyor belt 53 is pulled up by the upper face guide 83.
It is located away from the top surface of. The support plate 95 abuts against a push-down device 97, for example a cam device, by the force of a spring 96. From the time when paper is not fed as shown in FIG. 10, the holding plate 95 is pushed down by the rotation of the cam 99 by the operation of the push-down device 97, and the big unroller 58 is pushed down as shown in FIG.
one of them contacts the upper face guide 83 and pushes the upper face guide 83 down. The carrier i95 is pushed down until the transport heald 53 comes into contact with the recording paper 77 and sucks it.

As shown in FIG. 12, in the case of a cam device, the push-down device 97 has a paper feed cam 99 fixed to a shaft 98 at a predetermined interval and in the same posture. For example, as shown in FIG. 13, the paper feed cam 99 has an outer circumference of 144''.
It is formed as a circular arc surface B with a radius RI, for example, 10 mm from the center of the shaft 98, and the remaining range of 216a is divided into 108" portions, and the distribution is divided between the center point A and the radius R2, for example, 6 mm from the center of the shaft 98. Connect the arc surface B and the center point A with a smooth curved surface.

The shaft 98 is connected via a spring clutch 100 to a drive shaft 102 to which a pulley 101 is fixed. The pulley 101 is driven by a motor via a timing heald 103 and a reduction gear (not shown). A strike collar 104 is fixed to the shaft 98. As shown in FIG. 14, the stopper 104 has two stepped portions 105.1 on its outer periphery.
The stopper 104 is formed by a substantially spiral-shaped molded wheel having a diameter 06, and a claw portion of a locking bar 107 engages with one stepped portion 105 to prevent the stopper 104 from rotating. The lock 107 is rotatably supported by a support shaft 108, and is always held in the engagement position with the stepped portion 105 or 106 by a spring 109. A plunger of a paper feed solenoid 110 is connected to the locking nozzle \-107, and when the solenoid is energized, the locking nozzle \-107 rotates around the support shaft 108 against the force of the spring 109. 105 or 106 to release the lock from the stepped portion 105 or 106.

When the stopper 104 is rotated, the angle from the first step portion 105 to the second step portion 106 is set to 120°, and when the stopper 104 is locked at the first step portion 105, the locking bar 107
When the lock is released, the stopper 104 rotates 120 degrees, and the second step 106 locks the locking bar 1071, and the shaft 9
Stop rotation of B. The locking bar 10 is attached to the first stepped portion 105.
7 is locked, the paper feed cam 99 is at point A.
As shown in the figure, it is in contact with the support plate 95, and the support plate 95
is in the raised position.

The rotation of the pulley 101, which is driven by a motor (not shown) and is transmitted with rotation of 12 Orpm, is transmitted to the stopper 104 via a spring clutch 100, and when feeding paper, the paper feed solenoid 110 is energized and the stopper 104 is released. , the stopper 10 was constantly receiving rotational moment.
4 started rotating because the lock was released, and it took 0.25 seconds.
After ec, the paper feed solenoid 110 is deenergized and the locking bar 1
07 comes into contact with the outer peripheral surface of the stopper 104 again. At this time, the stopper 104 has already made a half turn (180°), so it has passed the second step 206, and when it has made one rotation, the claw of the locking bar 107 is closed.
05 to stop the stopper 104. This operation causes the cam 99 to rotate once every 0.5 seconds. The pink up roller 58 moves 4 times in 0.15 seconds together with the support plate 95.
It descends m and stops for 0.2 seconds. At this time, the 11th
As shown in the figure, the arcuate surface B of the cam 99 contacts the support plate 95 and pushes the support plate 95 down. After stopping for 0.2 seconds, it returns to its original position in 0.15 seconds. The pink-up roller 58 and a means for pushing down the pickup roller 58, such as a push-down device 97 and a support plate 95, act as a suction operating means for activating the suction of the conveyance heald 53.

The gap between the transport heald 53 and the recording paper 77 in the non-feeding state is about 4 mm, and the gap with the upper face guide 83 is about 2 mm.
It is m. Therefore, when the pick-up roller 58 moves downward, it descends by 2 m and comes into contact with the upper face guide 83, and then the upper face guide B3 is pushed down further and the 2ffi
IIl. At this lowered position, the conveyor belt 53 contacts the recording paper 77.

At this time, the recording paper 77 is attracted to the conveyance belt 53 by an unequal electric field caused by a charge pattern formed in advance on the outer peripheral surface of the conveyance heald 53 by the charging roller 76 . The rising tray 82 is formed and controlled so that immediately after the pickup roller 58 moves downward, the rising tray 82 rises until the contact pressure between the recording paper 77 and the conveyance heald 53 reaches a predetermined value, and then stops. . As a result, recording paper 7 due to paper feeding
It is possible to correct the change in the lowering of the upper surface position of 7, and the paper feeding position can always be maintained at the same height.

The conveyance belt 53 has a feeding function of feeding the recording paper from the paper feed tray 52, a conveyance function of conveying it to the transfer position, and a transfer function of contributing to the transfer to the recording paper at the transfer position.

Since the conveyor heald 53 attracts and feeds the recording paper using the attraction force generated by an unequal electric field instead of frictional force, there is no deviation of the recording paper, it has a registration function, there is no need to order paper powder during transportation, and there is no need to remove static electricity after transfer. There is no.

The second stepped portion 106 of the stopper 104 is used when the paper feed tray 52 is replenished with recording paper, as will be described later.

As shown in FIGS. 2 and 15, rising trays 82 are individually arranged in a right tray chamber 80 and a left tray chamber 81, which are divided by the central fence 78 of the paper feed tray 52. As shown in FIGS. 15 and 16, the lifting device 123 that moves each lifting tray 82 up and down moves the lifting tray 82 up and down at four locations.
The wires 111 are fixed to the wires 111, respectively. The first wire 1lla among the four wires 111 is connected to the first guide pulley 1
12, it is turned by the second guide pulley 113 and its end is wrapped around the first drive pulley 114.

The first drive pulley 114 is fixed to a shaft 115 rotatably supported by the frame 52a of the paper feed tray 52. Same first
One end of the second wire 111b is wound around the drive pulley 114, and the second wire 111b is turned and guided by the second guide pulley 113 along the way.

The third wire 111c and the fourth wire 111d, which are respectively fixed to the ascending tray 82 on the opposite side from the first wire 111a and the second wire 11lb, are attached to a second drive pulley 116 whose end portion is fixed to the shaft 115, respectively. It can be wrapped around. The third wire 111C, like the first wire 111a, is guided by the third guide pulley 117 and the fourth guide pulley 118 and is wound around the second drive pulley 116, and the fourth wire 111d, like the second wire 111b6, The second driving pulley 116 is guided only by the guide pulley 11B.
can be wrapped around.

One end of the shaft 115 is connected to the output side of the electromagnetic clutch 119, and an encoder 120 is fixed to the other end. The input side of the electromagnetic clutch 119 is connected to a tray motor 122 via a coupling 121. The coupling 121 is a drive half 1 connected to the tray motor 122 side.
21a and the driven half 1 connected to the electromagnetic clutch 119 side
21b.

The lifting tray 82 and the display device 123 are formed to have the same structure for both the right tray chamber 80 and the left tray chamber 81, but in the illustrated example, they are formed approximately symmetrically with respect to the center fence 78. Rising tray 82 for right tray chamber 80 and left tray chamber 8
The No. 1 lifting tray 82 can be driven by a separate tray motor 122. If it is necessary to distinguish between the right tray chamber 80 and the left tray chamber 81, the right tray chamber 80 and the left tray chamber 80 are distinguished by adding an A after the symbol and the left tray chamber by adding a B after the symbol.

The electromagnetic clutch 119 transmits drive only when the torque on the output side is less than a predetermined value in one direction of rotation, and slips and does not transmit drive when the torque on the output side is more than a predetermined value. There is.

As a result, the rising tray 82 on which the recording paper 77 is placed rises due to the rotation of the tray motor 122, but when the top surface of the recording paper 77 comes into contact with the conveyor belt 53 and receives pressure, the electromagnetic clutch 119 slips. As a result, the rising tray 82 no longer rises, and the tray motor 122 stops after a predetermined period of time, so that the uppermost surface of the recording paper 77 is always maintained at a constant height.

When replenishing the recording paper 77, the paper feed tray 52 is pulled out from the front of the copying machine 1. At this time, the driving half 121a of the coupling attached to the copying machine 1 side and the side of the paper feed tray 52 are pulled out. The driven half 121b of the coupling attached to the tray 82 comes off, and the rising tray 82 lowers to the lowest position under its own weight. At the same time, the tray open/close sensor 124 (Fig. 2)
detects that the paper feed tray 52 has been pulled out.

After replenishing the recording paper 77, when the paper feed tray 52 is pushed into the copying machine 1, the drive half 121a of the coupling attached to the copying machine side and the driven half of the coupling attached to the paper feed tray side The bodies 121b are engaged, and at the same time, the tray opening/closing sensor 124 detects that the paper feed tray 52 is set.

The paper feed solenoid 110 operates to move the locking bar 107 to the first position.
When rotated clockwise in FIG. 4, the claw portion of the locking bar 107 is removed from the first step portion 105 of the stopper 104. The stopper 104, which has always been subjected to clockwise (rightward) rotational moment by the spring clutch 100, starts to rotate clockwise (rightward) because the regulating member is no longer present.

After 0.1 sec, the paper feed solenoid 110 is released and the locking bar 107 is again subjected to a counterclockwise rotational moment and comes into contact with the outer peripheral surface of the stopper 104. At this time,
Since the stopper 104 has only rotated 115 times (72°), it comes into contact with the outer circumferential surface between the first stepped portion 105 and the second stepped portion 106.

When the stopper 104 rotates exactly 120 degrees, the locking bar 10
The claw portion 7 engages with the second stepped portion 106 of the stopper 104 and stops.

At this time, the B side of the cam 99 is in contact with the carrier plate 95 and is stopped, and the conveyance heald 53 is at the paper feeding position.

Next, the tray motor 122 is activated to raise the raising tray 82 together with the recording paper 77. When the top surface of the recording paper 77 comes into contact with the conveyance heald 53 and receives pressure, the electromagnetic brake 11
It is stopped by the action of 9.

After a predetermined time, the tray motor 122 stops. Then, the paper feed solenoid 110 is activated to rotate the locking bar 107 clockwise. Then, the claw portion of the locking bar 107 is removed from the second stepped portion 106 of the stopper 104. The stopper 104, which has always been subjected to clockwise (rightward) rotational moment by the spring clutch 100, starts rotating clockwise because the regulating member is no longer present.

After 0.1 sec, the paper feed solenoid 110 is released and the locking bar 107 rotates counterclockwise again.
7 hits the first stepped portion 105 of the stopper 104 again and stops. At this time, the conveyance heald 53 returns to its non-feeding position.

As described above, the first tray 52' and the second tray 52#
It is possible to replenish recording paper individually.

When the center fence 78 is folded down and A3 size recording paper is set in the paper feed tray 52 across the first tray 52' and the second tray 52#, the above-mentioned raising tray operation and cam operation are performed on the first tray 52' and the second tray 52'. , and the second Louis 52'' at the same time.

This widens the contact area of the conveyance heald 53 during paper feeding, thereby stabilizing paper feeding and conveyance.

As mentioned above, during normal image formation, the recording paper fixed by the fixing device 38 in FIG.
The paper is guided to the paper ejection path 42 by the paper I, and is ejected by the paper ejection roller 43. During double-sided copying, in which copies are made on both the front and back sides of the recording paper, the recording paper after fixing is reversed from front to back to the transfer position by the photoreceptor 31. It is necessary to feed paper to

For this reason, after the fixing device 38, the claw 41 allows the sheet discharge path 42 to be
A return guide path 44 is provided as a switchable branch path for guiding the recording paper to the paper feed tray 52.

The return guide path 44 includes a reversing path 45 as a branch path, and at the branching position, it connects directly to the paper feed tray 52 and the reversing path 45.
The first switching claw 46a can switch between the passage and the passage.

The recording paper sent to the return guide path 44 is sent to the first switching claw 46a by the feed roller 47, and the recording paper guided to the reversing path 45 is nipped and sent by the reversing roller 48, and the trailing edge of the recording paper is When the reversing sensor 125 detects this, the reversing roller 48 rotates in the reverse direction and the sheet is reversely fed. The recording paper that is fed backwards is the second one.
The feed roller 4 of the return guide path 44 is controlled by the switching claw 46b.
9 and is discharged onto the paper feed tray 52.

Like A3 copy, the first tray 52' and the second tray 5
2'' at the same time, the tray motor 122 is reversely rotated to lower the ascending tray 82 by a certain amount after the paper feeding operation for front side copying (the descending amount (movement amount) is memorized by an encoder (not shown)). After the recording paper 77 on which the front side has been copied is inserted into the paper feed tray 52, the ascending tray 82 is returned to its original position and the rear side copy feeding operation is performed.After the back side copy is completed, the recording paper 77 is ejected from the paper ejection path. Ru.

When using either the first tray 52' or the second tray 52'', such as A4 copying, if the front side copy is fed from the first tray 52', the tray motor 12 is
2, the ascending tray 82 of the second tray 52# is lowered by a certain amount (the descending amount (movement amount) is memorized by an encoder (not shown)), and the recording paper 77 whose front side has been copied is transferred to the second tray 52''. After the percentage is loaded, the ascending tray 82 is returned to its original position, and the feeding operation for back side copying is performed, and after the back side copying, the recording paper 77 is ejected from the paper ejection path.

On the other hand, when front side copies are fed from the second tray 52'', after the front side copy feeding operation, the tray motor 122 is reversely rotated to lower the ascending tray 82 of the second tray 52'' by a certain amount (using an encoder (not shown)). (memorize the lower r4 amount (movement amount)), recording paper 77 whose front side has been copied
After the second tray 52''+S is inserted, the ascending tray 82 is returned to its original position, and the feeding operation for backside copying is performed, and after the backside copying, the recording paper 77 is ejected from the paper ejection path.

A recording paper upper limit sensor 126 is provided above the second tray 52'', and when in double-sided image forming mode, even if you try to lower the ascending tray 82, when it is full of recording paper, the operation panel will not allow duplex copying. Display.

When you want to repeatedly form multiple images on the same side, such as composite copying instead of double-sided copying, the recording paper is moved to the reversing path 45.
The paper can be directly fed to the paper feed tray 52 by the first switching claw 46a without being guided by the paper feed tray 52.

In contrast to the automatic feeding of recording paper using the paper feed tray 52, there are cases where it is desired to manually feed the recording paper. For this purpose, a manual paper feeder 130 is provided.

The manual paper feed device includes a manual feed door (not shown) provided in the frame of the copying body 30, guide plates 131 and 132 that guide the recording paper inserted through the core feed door, and a manual paper feed roller 133.

When the manual feed door is opened, the manual feed mode is switched to, and the first driven roller 55 is returned to the manual feed home position.
When the manual feed sensor 134 detects that the recording paper is present in the manual paper feed device 130, a manual feed clutch (not shown) is activated, and the rotation of the manual paper feed roller 133 transports the recording paper onto the conveyor belt 53.

The copying machine 1 has a minimum unit composed of a scanner device 2 and a copying body 3, and can function as a normal copying machine. In case of
For example, it is possible to use a paper bank device 4 that can accommodate a paper feed tray or a paper feed power center, and includes a tray that can accommodate a large number of recording sheets. In this case, the copying body 3 is placed on the paper bank device 4 as shown in FIG. The casing of the copying body 3 has a paper feed path 136 that is open at the bottom and guides the recording paper fed from the paper bank device 4.
is provided. The paper feed path 136 is formed so as to be able to feed the recording paper to a home position, for example, to a two-tub position between the first driven roller 55 and the upper presser roller 74 located at the manual feed home position. A branch path 137 is provided in the paper feed path 136 so that the recording paper can be fed toward the first tray 52' of the paper feed tray 52, and a switching claw 138 is provided at the branch position to the branch path 137 to allow recording. It is possible to switch the paper feeding path. A paper bank paper feed sensor 139 is provided in the paper feed path 136 to detect that recording paper from the paper bank device 4 is fed. Paper banks are abbreviated as PB as necessary.

The paper bank device 4 has a 1st PB with a maximum loading capacity of 250 sheets.
A three-stage tray consisting of a ) ray 201, a second PB tray 202, and a third PB) ray 203, and a fourth PB) ray 204 with a maximum loading capacity of 2000 sheets are equipped. Paper is fed from each PB) ray 201 to 204 by one paper feeding conveyance device 20.
5.

The paper conveying device 205 has an endless conveying means, for example, one endless heald 218, as shown in FIGS. 2 and 17. The endless belt 218 includes a fixed driving roller 211, a movable tension roller 212, a fixed turning roller 213, a driven roller 214, a pickup roller 215, a pair of belt speed change rollers 216, and an auxiliary turning roller. It is wrapped around the entire roller 217.

17 to 19, guide rods 207 are provided almost vertically on the front side plate 205 and back side plate 206 of the paper bank device 4, and the paper feed unit 220 is vertically slidably guided by the guide rods 207. Ru. Paper feed unit 2
20 has a sheet feeding unit front side plate 222 and a sheet feeding unit back side plate 223 to which a bearing 221 that is slidably attached to a guide rod 207 is fixed. Paper feed unit front plate 2
22 and the pickup roller 2 so that both ends thereof are supported by the rear side plate 223 of the paper feed unit, respectively.
15 and an auxiliary turning roller 217 are arranged.

A pickup auxiliary roller 219 is disposed opposite to the driven roller 214 so as to press the conveyor belt, that is, the PB endless heald 218, and the paper feeding unit front plate 222
The sheet feeding unit is rotatably supported by the back side plate 223. The pickup auxiliary roller 219 uses PB when changing the conveyance direction.
It serves to prevent the recording paper from peeling off from the heald 218.

A shaft 21 that rotatably supports the pickup roller 215
Both ends of the paper feeding unit 5a are movably supported in an elongated hole 224 formed in the front side plate 222 of the paper feeding unit and an elongated hole 225 formed in the back side plate 223 of the paper feeding unit so as to be movable in a substantially horizontal direction. Further, both sides of the shaft 215a of the pink absorber 215 are fixed to timing healds 226 by fixing fittings 227, respectively. Timing belt 226 is wound around drive pulley 228 and driven pulley 229, respectively. The drive pulley 228 is fixed to a common drive shaft 231 driven by a motor 230, and the drive shaft 231 is rotatably supported by the paper feeding unit front plate 222 and the paper feeding unit rear side plate 223. The driven pulleys 229 are rotatably supported by shafts individually attached to the paper feeding unit front side plate 222 and the paper feeding unit rear side plate 223, respectively. The pick-up roller 215 is reciprocated along the long holes 224 and 225 by the forward and reverse rotation of the motor 230. Axis 21 of pickup roller 215
A home position feeler 232 and a bracket 234 for mounting an upper end detection sensor 233 for detecting the upper end of the recording paper are attached to 5a. When the home position feeler 232 activates the home position sensor 235 attached to the back side plate 223 of the paper feed unit, it is detected that the pick unroller 215 is at the home position. The upper end detection sensor 233 is the PB held 218
It is detected that the paper feeding surface of the recording paper is at a height of 5IIal from the top edge of the recording paper, and the paper feeding operation is performed from this position.

The display device 250 that moves the paper feed unit 220 up and down is powered by a motor 2 fixed to the back side plate 206 of the paper bank device.
51, and a drive shaft 25 rotatably supported by the back side plate 206 and the front side plate 205 and rotationally driven by the motor 251.
2, and two drive pulleys 2 fixed to the drive shaft 252.
53, a driven pulley 253 rotatably supported by the rear side Fi 206 and the front side plate 205, respectively, and a drive pulley 252.
and a driven boo 'J 253, respectively. timing held 2
54 are fixed to the front side plate 222 of the paper feeding unit and the back side plate 223 of the paper feeding unit, respectively, and when the timing heald 254 is moved by the forward/reverse drive of the motor 251, the paper feeding unit 220, that is, the front side plate 222 of the paper feeding unit and the back side plate 223 of the paper feeding unit The rear side plate 223 of the paper feeding unit is moved up and down.

Brackets 237 are fixed to the front shaft 236a, which is rotatably supported by the front side plate 222 of the paper feed unit, and the rear shaft 236b, which is rotatably supported by the rear side plate 223 of the paper feed unit, respectively. Both ends of the pair of heald speed change rollers 216 (216a, 216b) are supported. In other words, the first belt speed change roller 216a and the second heald speed change roller 216b are supported by the bracket 237, and the P that travels between the two heald speed change rollers 216a and 216b by the rotation of the shaft 236 (236a, 236b).
The relative position with respect to the B heald 218 is changed. coax 23
6 (front shaft 236a and rear shaft 236b) are rotationally driven by a motor 238 to which the rear shaft 236b is connected. rear axle 2
A feeler 239 is fixed to 36b, and the feeler 23
9 is a sensor 24 fixed to the back side plate 223 of the paper feed unit.
0, the home position of the belt speed change roller 216 is detected. By rotating the shaft 236, the belt speed change roller 216 wraps a part of the PB heald 218 around the first belt speed change roller 216a and the second heald speed change roller 216b before the paper feeding operation, and then wraps a part of the PB heald 218 around the first belt speed change roller 216a and the second heald speed change roller 216b before the paper feeding operation. The PB belt is returned to its original position by rotating the shaft 236 in the opposite direction to return the winding PB heald 218, and the feeding speed of the PB heald 218 is controlled.

P B Hell) 2180MIiM drive is 1uJ'
This is done by rotating the drive roller 211 by a transmission device having a gear 242 driven by a motor 241 attached to the +M2O6, and a gear 244 meshing with the gear 242 and fixed to the shaft 243 of the drive roller 211.

In order to attract and convey the recording paper, the PB heald 218 is provided with a charging roller to form a charge density pattern. In the illustrated example, the auxiliary turning roller 217 is used as the 11F electric roller, but it may be provided separately. Charging roller 21
7, an AC voltage is applied from the high-voltage power supply 245 at a position before contacting the recording paper, for example, ±2 KVP-P, 26 HZ.
is applied, thereby forming a stripe-like charge density pattern on the surface of the PB heald 218, in which charge densities -σ and +σ are arranged alternately at a period of, for example, five cabinets.

The paper feeding unit 220 feeds paper PB) rays 201 to 20.
The driven roller 2 is moved up and down according to the position of 4.
The adjustment roller 212 moves in accordance with the movement of the tension roller 14 so that the tension is always maintained constant. The end portion of the adjustment roller 212 supported by the front side plate 205 and the end portion supported by the back side plate 206 are each connected to a spring 247 via a wire 246, and are pulled in a direction that applies tension to the PB belt 218.

A first PB tray 20 is installed in the machine frame of the paper bank device 4.
1 to 4th PB) Opening/closing sensor 26 for each of the rays 204
1.262.263.264 are provided, and the opening and closing of each PB) ray 201 to 204 is detected.

For example, the 1st PB as a small tray with a maximum loading capacity of 250 sheets.
) As shown in FIG. 20, the tray 201 to the third PB tray 203 have a side fence 265 for determining the position of the recording sheets to be loaded (explaining the first PB tray 201).
and an end fence 266. The side fence 265 and end fence 266 guide the recording paper in three directions. A fence may be provided at the front end in the paper feeding direction as long as it does not interfere with paper feeding.

The side fence 265 and the end fence 266 are movable in the direction of the arrow according to the size of the paper. P.B.
) There is a handle 2 on the front wall of the Ray 201 for easy loading and unloading.
67 may also be provided.

In FIG. 21, for example, the fourth PB tray 204 as a large tray with a maximum loading capacity of 2,000 sheets is the same as the first PB tray in FIG.
Similar to the I-ray 201, a side fence 268, an end fence 269, and a handle 267 may be provided. Since the paper capacity is large in the fourth PB tray 204,
In order to prevent the paper from shifting, it is preferable that the side fence 268 is formed in an L shape and has a structure that guides the paper in the front, back, left and right directions. In this case, the cross-shaped side fence 268 is shaped so that it does not interfere with paper feeding.

The PB heald 53 in the copying body 3 attracts and conveys the recording paper with a charge density pattern formed by the charging roller 76.
In the paper bank device 4, a charge density pattern is formed on the PB belt 218 by an auxiliary turning roller 217 acting as a charging roller, and the recording paper is attracted and conveyed. For this reason, the conveyor belt 53 and the PB belt 218 are formed as endless belts having a dielectric layer 53a capable of retaining charges on the surface layer and a semiconductor layer 53b on the back surface. At least one of the rollers supporting the conveyor belt 53.218, for example roller 56.215, is grounded and arranged in contact with the back side of the belt.

For example, as shown in FIG. 22, an alternating electric field (A Hz) is applied to the charging rollers 76 and 217 (only the charging roller 76 is shown in the figure) from the high voltage power source 131 to the ground roller 5.
Applied as the opposite of 6. The transport heald 53 is moved at a constant speed LIW! in the direction of the arrow by the drive roller 54. The position of the pickup roller, which moves at a speed of A/s and contacts and attracts the recording paper, is downstream of the position of contact with the charging roller 76 in the moving direction of the conveyor belt 53. Therefore, an alternating voltage is applied to the conveyance heald 53 via the charging roller 76 from the high voltage power source 131 before the recording paper comes into contact with the surface thereof. As a result, a striped charge density pattern is formed on the surface of the transport heald 53, in which charge densities -σ and +σ are alternately arranged at a period of Ll/Aam. Charges of opposite polarity are induced in the semiconductor layer on the back surface of the transport heald 53 due to the charge density formed on the surface of the transport heald.

When the charge density pattern shown in FIG. 22 is formed, unequal charges 132 are formed near the surface of the conveyor belt 530 as shown in FIG. 23, and this electric field causes the dielectric material that is the recording paper 77 to The force acting on a unit volume can also be determined using Maxwell's dynamic force. The recording paper 77 is electrostatically attracted to the conveyor belt 53 by the force Fx in the direction perpendicular to the surface of the recording paper 77, that is, the surface of the sheet, and is held without shifting.
3, and the paper is fed and conveyed.

When the direction perpendicular to the sheet surface is x, the Wi feeding direction is y, and the direction perpendicular to the feeding direction within the sheet surface is 2, the x, y, and component forces of the force acting on the unit volume of the dielectric are FX, Fy, Fz Then, it becomes.

Maxwell stress tensor 5p, -Article (E, 9.) Mutual ρ.

From EY Inside EY - Go U・pノ E2'f' This attraction principle is different from the generally known force of attraction between charges of opposite signs, and the recording paper can be attracted using the above-described method without applying a valley charge to the recording paper. For this reason, even when used in a paper feed conveyance device of an electrostatic recording device, there is no effect on the transfer process.

Although the example of the charge density pattern is striped, it may be a checkerboard pattern, or any other suitable pattern may be used.

As shown in Fig. 24, A3 size plain paper is fed to the transport heald, and when the contact length reaches 100 m, a spring scale 133 is attached to the rear end of the paper, and the suction force is calculated as tensile strength. As a result of the measurement, the results shown in FIG. 25 were obtained. The adsorption area at this time is 300 crn2.

In Figure 25, the amplitude of the AC voltage is constant, for example 4KVF.
-P, and the results of measuring the adsorption force while changing the applied frequency are shown. From this, in the present invention, the period of the stripe shape is set to 2.
Sufficient adsorption force was obtained when it was within the range of 0++o or less, especially 1oIII11 or less. Further, as shown in FIG. 26, the adhesion force was measured by changing the applied voltage while keeping the applied frequency constant, for example, 26H2, and from the results, a good one-holding force was obtained at 2 KV□1 or more. Furthermore, it was found from measuring the surface potential that no charge density pattern was formed on the heald at the applied voltage at which no adsorption force was generated. For this reason, in order to generate adsorption force, at least an applied voltage higher than the charging start voltage is required.

Further, the applied voltage is the same when a DC component is superimposed on an AC voltage, or when a non-uniform alternating voltage is applied from a power source that outputs a non-uniform alternating voltage.

FIG. 22 shows the belt configuration used in the paper feeding and conveying device of the present invention. The transport heald 53 is a two-layer type, with the surface layer being a dielectric film (polyester resin 20 μm, volume resistance 101'Ωcm), and the lower layer being a semiconductor layer (carbon dispersed in polyester resin 801tm, body resistance [10''ΩC).
1) is configured as an endless heald, and is rotatably supported by a drive roller and a plurality of support rows.

The charging roller 76 has a high voltage 11i[j131 to +2K
An alternating voltage of V, 24H2 is applied. Further, the conveyor belt 53 is moved at a constant speed of 1 in the direction of the arrow by the driving row.
It moves at 20 mm/s, and the feeding position of the recording paper is downstream of the contact position of the electrode of the charging roller 76 with respect to the moving direction of the conveyor belt 53. Therefore, before the recording paper is fed to the surface of the conveyor belt 53, a charge density pattern is formed on the surface of the conveyor heald at a period of 5w.

Here, the volume resistance of the back surface of the conveyor belt 53 is 10@Ωα
The reason for this is that setting the transfer means on the back side requires 1
This is because it had to be at least 0.07Ω1.

In addition, the above resistance was chosen because the adsorption force was greater when there was a difference in resistance with the surface layer. However, if the volume resistivity of the back surface is practically in the range of 10<7 >[Omega]C11 to 10''0 cm, there will be no functional problem.

In FIG. 23, the PB heald 218 used in the paper feeding and conveying device of the paper bank device 4 of the present invention is constructed as an endless heald with a single layer type, the surface layer of which is a dielectric film (PET 50 μm), and the lower layer of which is vapor-deposited aluminum. It is supported freely by the supporting cola.

The volume resistance of this dielectric material was set to 10''Ω1.An alternating voltage of ±2KV, 26Hz is applied to the charging roller 217 from the high-voltage power source B.The PB heald 2]8 is moved in the direction of the arrow by the drive roller. It moves at a constant speed of 130 m+n/s, and the feeding position of the recording paper is downstream of the contact position of the electrode of the charging roller 217 with respect to the moving direction of the PB belt.Therefore, the recording paper is placed on the surface of the PB held. Prior to paper feeding, a charge density pattern is formed on the surface of the PB belt for five embryonic cycles.

The PB held 218 in the paper bank device 4 is the first
The recording paper is sucked and fed from the FBI-ray 201 to the fourth PBl-ray 204. For this purpose, the elevating device 250 is operated, and the paper feeding unit 220 moves from the first PB tray 201 to
It moves up and down in front of the third PB) ray 203 and is stopped at the sheet feeding home position of the first PB) ray 201 to the third PB tray 203. In FIG. 17, the fourth PBl-ray 204 is the first PB) ray 201 to the third PB tray 203.
The paper feeding unit 220 can be moved directly onto the recording paper in the fourth PB tray, but it is arranged in the same line as the first to third PB trays 203, and the paper feeding unit 220 can be moved directly onto the recording paper in the fourth PB tray. It can also be configured to move up and down in front of 204.

The paper feeding home position for any PB) ray is a certain distance above the top edge of the recording paper, for example, 5 mm above, and when the paper feeding unit 220 moves to the paper feeding home position of the selected PB) ray, PB Held 21
8 is located five images above the top edge of the recording paper.

When the PB heald 218 contacts the recording paper and feeds the recording paper by suction, the relative speed of a portion of the PB heald, that is, the contact portion with the recording paper, is changed to almost zero.

In order to change the feeding speed of a portion of the PB belt 218, that is, the relative speed with respect to the static recording paper, a feeding speed changing means;
For example, a pair of heald speed change rollers 216 (216a and 2
16 b) is used.

In FIG. 27, heald speed change rollers 216a, 216
For example, b is a roller with a diameter of 8 strokes, and the distance between the centers of the heald speed change rollers 216a and 216b is 12 m,
The motor 23 rotates the belt speed change roller 2 around the approximate center point between the axes of the belt speed change rollers 216a and 216b.
16a and 216b are rotated to wind the PB belt 218 around the belt speed change rollers 216a and 216b, and to unwind the belt. In the 27th turn, the PB belt is rotated around the center 01 by an angle θ from the release position where the PB belt shown by the solid line simply contacts the heald speed change rollers 216a and 216b.

When the PB heald 218 itself is not being conveyed, the PB belt moves by the amount l caused by the rotation of the belt speed change rollers 216a and 216b by θ (rad).
teeth, ! =2γθ+12(1−cosθ) Here, γ is the radius of the winding of the belt speed change rollers 216a and 216b.

From the relationship θ-ωt, the transition speed ■ can be expressed as a time derivative,
V=2γω+12ωsinωL. Here, ω is the rotational angular velocity.

When the PB belt 218 is moving at a constant speed of 130 man/sec and the paper feeding unit 220 is moving at a speed of 150 a/sec, the contact area of the PB belt 218 with the recording paper should move at a rate of 280 mm/sec. In order to become P
In order to stop the B heald 218 in the area of contact with the recording paper, it is necessary to cancel this speed. For this purpose, by setting the displacement speed (2) to 280 images/sec, the angular velocity ω, that is, the driving speed of the motor 238 that rotates the shaft 236 is obtained.

In other words, in the case of the 1st PB) tray 201 to the 3rd PB tray 203, the paper feeding unit 220 is landed at 150 brains/sec from the paper feeding home position shown in No. 2811JA to the position where it contacts the recording paper shown in FIG. 28B. At this time, the heald speed change roller 216 moves in the direction in which the PB belt 218 is unwound from the heald speed change rollers 216a, 216b as shown in FIG. 28A, for example, clockwise in the figure. 216a, 216b are rotated. The part of the PB belt 218 that contacts the recording paper is almost stationary, and the recording paper is moved to the PB belt 218.
Electrostatic adsorption due to the charge density pattern.

Thereafter, the paper feeding unit 220 is returned to the paper feeding home position shown in FIG. 28C.

4th PB) In the case of the ray 204, the recording paper 7 is
7 is fed by suction. In the case of the fourth PB tray 204, the leading edge of the recording paper 77 is sucked away from the contact area of the PB belt 21B, so if the recording paper is conveyed in this state, the recording paper will gradually separate from the PB belt starting from the leading edge. It turns out.

Therefore, the PB heald 218 descends from the paper feed home position shown in FIG. 29(A) to the position shown in FIG. 29(B), contacts the recording paper 77 in a stationary state, sucks it, and then
As shown in FIG. 9C, while the paper feeding unit 220 is raised and returned to the paper feeding home position, the leading edge of the recording paper is retreated by a certain amount to a position where it contacts the driven roller 214.

For example, if the paper feed unit 220 is moved backward by 20 holes, the time it takes for the paper feed unit 220 to return to the paper feed home position is 5 (+ae) /150 (arm/sec)
= 0.033 (sec), and the linear velocity of the PB heald 218 in the opposite direction is 20 (mm) 10.033 (sec).
)=600 (mm/5ec). PB Held 2
18 is uniformly conveyed and transported at 130 mm/sec, so when the paper feed unit 220 rises at 150 an/sec, the PB heald 218 returns at the contact surface with the recording paper at 600+130 150=580 mm/sec. In this way, the heald speed change rollers 2 and 6 are unwound and rotated. Therefore, the above transition speed ■ is set to 580 m/sec.
c to control the speed of motor 238.

PB held 218 in the paper feeding process for the next recording paper
In preparation for the deceleration of the recording paper contact area, the heald speed change roller 216 is rotated in the range between adjacent recording papers being conveyed.

In contrast to the structure in which two rollers are rotated as in the example shown in FIGS. 27 to 29, as shown in FIGS. 30 and 31,
A structure having two fixed rollers 216' and one variable speed roller 216# disposed therebetween can be used. FIG. 30 shows an example used for the 1st PB) Ray 2] 0 to 3rd PB tray 203 as shown in FIG.
FIG. 1 shows an example of use in the fourth PB tray 204 as shown in FIG. 29. In FIG. 30, the variable speed roller 216# moves to the paper feeding home position shown by the solid line, and while descending from that position to the position where it contacts the recording paper, it moves to the left in the figure and transfers to the PB position.
The speed of the recording paper contact area of the heald is reduced or stopped, and the displacement roller 216N is displaced to the leftmost position in the figure at the position where the heald returns to the paper feeding home position.

In FIG. 31, a process of retracting the recording paper contact area of the PB heald in the opposite direction is added to the example of FIG. 30.

Paper feed unit) 220 is paper feed unit (150)
The time it takes to contact the recording paper after reaching 5 mm in age at the anus/sec is: 5 (m) / 150 (mm/5ec) - 0.03
During this time, the PB belt 218 is driven at a constant speed of 130 mm/sec and the roller is displaced in the negative direction at a force of 280 rrrm/sec in order to cancel the downward displacement due to the landing speed of 150 m/see of the paper feed unit 22o. 216". This displacement is performed for 0.033 seconds, so the amount of displacement is 280 (nnn/5ec) x 0.033 (sec
) -9,3 (round). For this purpose, change position~2
16# is 280 (pictures/5ec)/2 = 140 (
It is sufficient to move at a constant velocity of 9.3 (Mm) /2 = 4.7 (+mn) to the left in the figure at a speed of mm/5ec).

In FIG. 31, since the leading edge of the recording paper is further transported backward to the position of the driven roller 214, the displacement roller 216# moves at a constant speed to the left in the figure at a speed of 290 k/sec and a displacement of 9.7 k/sec. do.

The speed change operation is performed until the axial center of the displacement roller 2 G# reaches the point where it moves to the left from the line connecting the axial centers of the fixed roller 216'.
In other words, a total displacement of 14.4 mm is performed by constant velocity control.

The electrical components of this copying machine will be explained.

In FIG. 32, the main control board 401 is an internal
! It may be a one-chip CPU including l<CPU, ROM, RAM, timer, and I10 functions. The main control board 401 performs overall sequence control.

The apparatus will be roughly divided into the copying main body side and the paper bank side.

First, the electrical system on the main body side will be explained. The main body side can be roughly divided by function: image creation related, 1st PB tray related,
2nd PB) Ray-related, duplex-related, transport-related, and other related matters.

First, other related matters will be explained. Reference numeral 402 denotes an operation display board, which is capable of serial communication with the main control board so that commands or data can be exchanged. 2 is a scanner unit, and a scanner control board 408 transfers read image data and commands;
Sending and receiving data. This scanner section is not directly related to the present invention, so a description thereof will be omitted.

Next, information related to image formation will be explained. 403 is a main motor, which drives the photoreceptor, fixing device, cleaner, and other driving rollers of the conveyance device, and 405 is a driver thereof. A fixing temperature controller 406 keeps the fixing temperature constant.

The image data read by the scanner is sent to a semiconductor laser 2, and its beam signal is transmitted in main scanning by a polygon motor 26 driven by a polygon motor driver 407. The synchronization detection sensor 30 is a sensor that determines the timing for writing image data.

The static elimination lamp 36 is a device that eliminates the potential of the photoreceptor. 41
0.409 is the developing motor and its driver. 37 is a photosensor that detects the standard pattern. 411 is a high-voltage power supply for the image forming system, and the charging corona, developing bias, transfer corona, and cleaning bias are individually set to 0N10FF.
It is now possible.

Next, electrical equipment related to the first tray 52' of the feeding tray 52 will be explained. ll0A is paper feed solenoid, l1
9A is a powder clutch, 122A, 415 is a PB) Ray motor and its driver, and a stepping motor is used as the motor. When a pulse signal is received from the drive L driver main control board, the number of pulses is used to control the amount of movement, and the frequency of the pulses is used to control the movement speed, so that the 7-pin motor is excited. Further, in this example, the self-starting frequency region is used, but if the load torque is large, slow-up or slow-down control may be performed.

The encoder 120A is used to detect the remaining amount of paper, that is, the amount of recording paper remaining. 94A is a paper end sensor, which is a sensor that detects the presence or absence of recording paper on the first tray.

110B, 119B, 122B, 416.94B, 12
0B is an electrical system that performs paper feeding related operations for the second tray 52'', and has the same configuration and function as the first tray.

Next, transport related matters will be explained. Manual clutch 13
6 is driven during manual paper feeding to convey the recording paper. The manual feed sensor 134 is a sensor that detects the paper position during paper feeding.

Reference numeral 125.412 denotes a heald drive motor and its driver, which rotates the conveyor belt 53 at a constant speed. In this example, a stepping motor is used to perform the rotation operation in accordance with pulse signals from the main control board.

The registration sensor 135 detects the leading edge of the recording paper fed and conveyed from each tray 52', 52'', and calculates the laser writing start timing from this, and also calculates the 0N10FF timing of the image forming system and double-sided conveyance system. It is made to decide.

Reference numeral 68 and 413 denote a roller moving drive motor and its driver, which, like the heald drive motor 125, rotates in response to pulse signals from the main control board. However, the pulse input to the driver in order to zero the feeding speed of the conveyance heald causes the heald to be stopped by giving a pulse signal with half the frequency of the pulse signal applied to the heald drive motor driver 412. I can do things.

Furthermore, the direction of roller movement can be controlled by a CW/CCW switching signal. In this case, it is the CW (clockwise) side or the direction when temporarily stopping the heald, and the CC
The W (counterclockwise) side is the direction when retracting the roller to the home position.

The home sensor 71 is designed to detect the home position of the roller.

A high-voltage power source (A) 414 generates an AC high-voltage power source, which applies high voltage to the heald as the transport heald 53 moves, thereby forming a positive and negative charge pattern on the heald. This charge pattern forms an unequal electric field, allowing the recording paper to be electrostatically attracted onto the belt. The adsorption force of this positive and negative charge pattern is influenced by the pitch and the applied voltage level. The maximum suction force is obtained at a certain appropriate pinch interval, and paper is fed and conveyed in the region of this maximum suction force. In other words, the applied frequency at which the maximum adsorption force can be obtained is determined based on the heald speed. Furthermore, as the pitch interval is narrowed, that is, as the applied frequency is increased, there is a pitch interval at which the attraction force becomes zero, and this has the same effect as eliminating static on the heald. This power supply is controlled by three signal lines, and performs attraction of the recording paper, neutralization on the belt, and switching of the high voltage level for the cardboard.

Paper upper limit sensor 12G Tray open/close sensor 124,
The paper size sensor 93 is related to the paper feed tray 52, the first tray 52', and the second tray 52#.

Next, a description will be given regarding double-sided image formation. 417.4
18.125.420.4] 9 is a double-sided noid 418 that switches between the first switching claw 46a and the second switching claw 46b. The reversal sensor 125 detects the presence or absence of recording paper during duplex operation, and activates the forward/reverse reversal motor 420 and its driver 419.
The timing of the forward and reverse signals given to the This forward/reverse reversal motor is formed by a motor that performs forward/reverse rotation at a linear speed faster than that of the image forming and transport system.

A replenishment solenoid 421 is a solenoid for switching the switching claw 138 for replenishing the first tray 52' with recording paper from the paper bank device 4. The paper bank paper feed sensor 139 detects the leading edge of the recording paper from the paper bank side, and thereby reduces the O of each load on the main body side.
N10 FF Adjust the F timing.

Next, the electrical system on the paper bank side will be explained.

241.425 is a PB heald drive motor and its driver, which has the function of conveying the recording paper to the main body side.

Here, a stepping motor is used.

Reference numerals 251 and 422 denote a paper feed unit drive motor and driver, which perform an elevating operation of the paper feed unit 220. 2
Reference numeral 56 denotes a paper feed unit position sensor, and position control is performed using this as a reference.

Reference numerals 230 and 423 denote a pickup drive motor and a driver, which use a stepping motor to pink up the recording paper. The pickup sensor (the home position sensor) 235 is a reference sensor for position control of the pickup roller.

238.424 is a PB belt variable speed motor and driver, which temporarily stops the heald in order to attract and hold the recording paper. 240 is a PB held variable speed reference sensor that detects the reference position.

Reference numeral 233 denotes a paper top edge detection sensor, which detects the position of the paper feed unit 220 with respect to the recording paper tk:&-.

A high voltage power source (B) 427 applies a high voltage to the PB heald similarly to the high voltage power source (A) to generate an adsorption force to the recording paper.

426 is a paper size sensor, No. 1.2.3.4PB
) Detect the paper size on the lay. 261.262.26
3.264 is a tray opening/closing sensor, which detects opening/closing of the PB) lay.

In the printer mode, this device is commanded by a control command from a host computer that sends print data. Meanwhile, equipped with a reading scanner,
When using it as a copying machine, use the input key to issue the command.
It requires an operation section with a mode indicator. The main input keys include the print and stop keys that support starting and stopping the copying machine, the 10 key that sets the number of copies, the auto density and density adjustment keys that adjust the copy density, and the magnification and zoom keys that specify the magnification. etc. Further, the operation section is constituted by an LCD panel that shows the input state thereof.

As shown in FIG. 33, the operation section 600 includes an operation panel 60.
1, and in addition to the above-mentioned various keys (not shown), there is a page continuous copy key 603 for continuously copying a double-page spread document such as a book onto two sheets of recording paper, and a double-sided key 6 for copying on both sides of the recording paper.
04, a continuous paper feed key 605 that feeds recording paper continuously without paper gaps, and a replenishment key 606 that transports paper from the lower PB tray to the upper stage. Further, when each mode is designated manually by the key, 611 lights up from the LCD 60B provided corresponding to each key.

Continuous page copying, double-sided printing, and continuous paper feeding mode are established independently, and 3
If both modes are specified, the continuous page quick copy double-sided mode is used, and high-speed copying of the book original is performed. The replenishment mode transports and replenishes recording paper to the upper tray with a short transport path during a pre-specified time when the device is not operational, such as at night.This mode can be set manually or automatically. good. Further, the cardboard display 607 is turned on by manual operation of the cardboard key 602, and the paper feeding conditions (for example, charge pattern intensity, charge pattern area, etc.) from the paper feed tray and paper bank are changed.

The multi-stage paper feed of this apparatus is displayed on the paper display section 613 of the LCD in the operation panel. The size of the recording paper stored in the paper feed tray of each stage is displayed on each size display 614 to 619.
The amount of paper remaining in each row is also displayed. In the figure, A4 size is selected for the 4th PB (Reiro 19). In addition, by manual operation of the paper selection key 621,
The trays to be fed paper are sequentially selected, and the selected trays are displayed on the paper display section 613. On the other hand, the manual paper feed section 13
By opening the manual feed door of 0, the manual feed display 620
lights up, the paper is fed preferentially from the manual paper feed section 130, and
The selected tray display on the paper display section 613 is turned off.

The operation of this device will be explained based on a flow chart and a time chart.

In FIG. 34, after the power is turned on, initial settings are made and the initial movement of the rollers is performed. This is an operation for retracting the first driven roller 55 to the home position. After that, the 35th
Perform initial paper feeding operations based on the diagram.

After the initial paper feeding operation, if there is a mode change, a new mode is set. Mode changes are entered into the main control board as coded serial data by manual keystrokes on the operation display board. This causes a reception interrupt and determines the serial data. A flowchart of the reception interrupt is shown in FIG.

After the mode is set, it is determined whether the paper feeding initial operation needs to be performed again. The first case is when the paper feed tray is pulled out and the user manually replenishes the recording paper and then resets it, the second case is after the replenishment operation is completed, and the third case is when the duplex mode is set. In either case, by setting and resetting the flag, it is determined whether to return to step (3) and perform the initial paper feeding operation.

After that, size detection, heater temperature control, remaining amount detection, paper feed priority, suction voltage setting, replenishment processing, detection of the number of sheets that can be printed on both sides, detection of the number of sheets that can be printed on both page continuous shooting devices, various sensor inputs, and cents and reset of flags accordingly. After executing the subroutine group for the non-pulse operation processing, a flag is used to determine whether the print switch has been pressed. If the print SW is not pressed, return to mode change processing and print)
Repeat the loop until SW is pressed. When the print switch is pressed, the pulse counter is reset and starts counting. The pulse counter here is a counter that counts up by a timer interrupt as shown in FIG.
An internal interrupt that occurs within the CPU at regular intervals.
The cutting time is set by default.

After the count starts, a pulse table corresponding to each mode is set and compared with the pulse count value. Here, the pulse table corresponding to each mode is a table of the number of pulses at the ○N10FF timing of each load divided for each mode. If the table value and the counter value do not match, the process branches and executes the above-mentioned non-pulse operation process, and if the final copying process has not been completed, the process returns to (2) and is repeated thereafter. When the table value and the counter value match, the subroutine on the pulse table is executed, the pulse table is incremented, and processing outside the pulse operation is executed, and when the final copying process is completed, the process returns to (2) and repeats the loop.

In the initial sheet feeding operation, as shown in FIG. 35, pulses are output from the main control board to the roller moving motor 6B, heald drive motor, and their respective drivers. In this case, the number of pulses corresponding to the amount of movement and the pulse frequency corresponding to the speed of movement are set in advance.

Next, after turning on the paper feed solenoid 110, the paper feed timer counter is reset and starts counting. The paper feed counter is a counter that is incremented by the timer interrupt, and it is determined whether 0.1 seconds have elapsed since the count value, and the paper feed solenoid 110 is turned off after the elapse of 0.1 seconds. After that, the encoder timer counter is set seven times and starts counting.

This encoder is a drive shaft 115 that is driven by the shaft of a tray motor 122 via a powder clutch 119.
This is the sensor 120 that is attached. after that,
After turning on the powder clutch, a pulse is output to the tray motor drive driver. The number of pulses at this time should be enough to make the ascending tray 82 on which no recording paper is loaded come into contact with the transport heald 53 at the landing position of the recording paper contacting part of the transport heald 53. The quotient frequency should be set to a level that does not occur. After that, when the encoder interrupt shown in FIG. 38 does not come in, it is determined that the count has ended, and the counter value is set to RA.
M Hess door. This counter value is inversely proportional to the amount of recording paper remaining on the tray, and the remaining amount of recording paper can be detected based on this value. After outputting pulses to the tray motor, set the paper feed solenoid 110 to 0N10FFL as above.
After outputting a pulse to the belt moving motor 68, the rotation direction of the heald moving motor is switched to, for example, CCW (counterclockwise), and the pulse is output again to retreat to the home position. After detection by the home sensor 71, the pulse output is stopped. and end the process.

A timing chart showing the above operation is shown in FIG.

Note that the initial paper feeding operation is performed by the first tray 52' and the second tray 5.
2'' are performed individually.

The transferred recording paper is transferred and fixed in a known manner.

Next, various operation modes will be explained.

[Continuous paper feeding mode]

In the continuous paper feeding mode, serial data indicating the continuous paper feeding mode is transmitted from the operation display board by inputting the continuous paper feeding key 605 on the operation unit shown in FIG. Upon receiving this, the main control board generates a reception interrupt (Fig. 36) and sets a continuous paper feed flag.

When the continuous paper feed flag is set, a new mode setting is performed in the main flowchart shown in Fig. 34, and when the print switch is pressed, the pulse table shown in the timing chart shown in Fig. 46 is used to set the ○N10 F F of each load. Execute sequence operations. Before explaining the timing chart, paper feed priority will be explained. This means that when recording paper of the same size, direction, and quality as the first tray 52' is selected, the first tray 52' is fed and transported with priority, and the flow is shown in the main flowchart. This is set in the pulse-operated valve processing subroutine group. The purpose of this is to shorten the first copy time and improve preparation efficiency. FIG. 39 shows a paper feed priority flowchart.

Next, the timing chart of the continuous copy mode shown in FIG. 45 will be explained.

When the print SW is pressed (step 1), the main, current a mode 9, charging corona, and cleaning high ass (CL bias) are turned on (step 2). At the same time, a pulse is output to the belt drive motor (step 3), the conveyor belt 53 is driven, and the high voltage electric current #(A) is turned on at the attraction frequency (step 4), and the charge density pattern is formed by the charging roller 26. will be held. After that, pulse output to the roller moving motor 68 (Step 6), forward and reverse clockwise (CW) and counterclockwise (CCW) (Step 7), detection of the home sensor 71 (Step 8), paper feed solenoid 110A is turned on (step 9), powder clutch 119A is turned on (step 10),
PB) Pulse output to Ray motor 122A (Step 11)
The paper feeding operation is performed by When using the first tray 52' and the second tray 52'' at the same time, such as with A3 size recording paper, turn on the paper feed solenoid ll0B (step 12).
, turn on the powder clutch 119B (step 13), and output pulses to the tray motor 122B (step 14) at the same time. A detailed timing chart of the paper feeding operation is shown in FIG.

In FIG. 46, pulses of rotation in the clockwise direction (CW force direction) are output to the roller moving motor 68. While this output is being performed, the belt is in a stopped state. The paper feed solenoid 110 is turned on in synchronization with the output, and the transport heald moves from the normal position to the lowered position in 0.15 seconds as shown in the landing movement diagram.

Thereafter, a pulse output is applied to the tray motor 122 to press the recording paper against the conveyance heald 53 to adsorb it. At this time, the number of pulses given to the tray motor 122A is limited to the number of pulses given to the recording paper 122A because the tray has already been raised due to the initial paper feeding operation.
It is sufficient to give a number of pulses that has enough margin for the thickness of the sheet plus the pressing force.

After paper feeding, the roller moving motor 68 is switched to the CCW direction to output pulses in order to retract the pickup roller to the home position, and the pickup roller returns to the home position detected by the home sensor 71.

In the case of continuous paper feeding, the paper feeding operation is started at the timing when the trailing edge of the fed recording paper passes the right fence 79 of the paper feeding tray, so that paper feeding and conveyance with substantially zero paper interval is performed.

Referring back to FIG. 46, after the sheet feeding operation is completed, the recording sheet is detected by the registration sensor (step 15). Based on this point, subsequent pulses are counted to determine the 0N10FF timing of each load. As a result, the ON/FF timing of the writing gate, developing bias, and transfer corona is set, and image formation is performed (steps 16, 17, and 18). This is an example in which three sheets of recording paper are fed and conveyed and image formation is performed.

The adsorption OFF timing of the high voltage power supply (A) is 0FFL at the timing when the charge pattern is formed up to the rear end of the scarlet recording paper.
The static elimination is turned on to eliminate the adsorbed charge pattern on the belt, thereby preventing the recording paper from being adsorbed outside the paper feeding operation, for example, during the initial paper feeding operation. For this reason, the machine is stopped either after the purest recording paper is discharged from the machine or after static electricity has been removed from the suction area, whichever is longer.

[Page continuous shooting mode] FIG. 47 shows a timing chart of page continuous shooting mode.

Page continuous shooting mode means that the first tray 52' and the second tray 52''
In this mode, two paper feeding operations are performed simultaneously, two sheets of recording paper are simultaneously adsorbed and transported onto the transport heald, and images are formed. The timing chart shows an example in which this simultaneous sheet feeding operation is performed twice to form images on a total of four sheets. Similarly to the continuous paper feeding operation mode, a reception interrupt is generated by inputting the page continuous copying key from the operation unit, and a new mode is set by setting the page continuous copying flag. In FIG. 47, image formation is basically the same as in the continuous paper feeding mode, and the only difference is that steps 9.10.11 regarding the first tray 52' and steps 9.10.11 regarding the second tray 52'
Similar steps 12, 13, and 14 regarding 2# are carried out in synchronized timing to perform the sheet feeding operation. That is, the paper feed solenoids 110A and 110B are operated in synchronization, and the recording paper contact area of the conveyor belt 53 is simultaneously lowered.
The rising tray 82A of the first tray 52' and the second tray 52
The # rising tray 82B rises synchronously and the first tray 5
The recording paper in the tray 2' and the recording paper in the second tray 52'' are simultaneously attracted and conveyed.

Further, the timing of the next paper feeding operation is such that the trailing edge of the recording paper fed by the second loop passes through the right fence 79 that contacts the leading edge of the recording paper in the first tray. For this reason, step 6
．． It becomes ○N10FF or detection timing like 7.8. In step 4.5, the timing is as shown in the figure because the recording paper area is attracted and static electricity is removed.

[Continuous paper feeding duplex mode]

In the continuous paper feeding duplex mode, after image formation on the front side, the recording paper is reversed by the reversing device and temporarily stored on the second tray 52'', only the number plate is stored on the second tray 52'', and then the recording paper is stored on the second tray 52''. 5
2'' is fed, and images are formed on the back side.The problem here is that unrecorded recording paper is stored on the second tray 52''. From this remaining amount, the number of double-sided sheets possible (second
Detection of the remaining amount is performed in the main flowchart described above.Here, detection of the number of sheets that can be double-sided copied will be explained with reference to the flowchart of FIG. 40.

In the main flowchart, when the duplex flag is set, the initial sheet feeding operation is performed as described above. Than this,
The encoder count value is stored in RAM. This value is set to a on the first tray side and b on the second tray side. Detection of the number of sheets that can be printed on both sides is set in the subroutine group of non-pulse operation processing in the main flowchart. When executed,
First, the state of the double-sided flag is determined, and if it is not set, the process ends. If it is set, the number C of double-sided sheets that can be printed is calculated from the remaining amount on the second tray side.

This process is performed sequentially by calculation, or the number of double-sided sheets that can be printed for a value set in advance in a table may be called. Next, a determination is made as to whether or not the number board is C. If YES, an error message is displayed on the operation display board, and a message is sent to display an instruction to move the number board below C. . Thereafter, after the print SW flag is invalidated (in this state, even if the print SW is pressed, it does not start), the process ends. When the number board is reset to below C by the user and detection of the number of double-sided sheets possible is performed again, the number board>C becomes No, an error display clear message is sent to the operation display board, and the print SW flag validation process is executed. and ends the process.

When the print SW is pressed in this state, the operation is executed as shown in the 48th timing chart. When the print SW is pressed, step 2.3.4 is performed in the same way as in the continuous paper feeding mode shown in FIG. The difference is that the powder clutch 119B in step 13 is turned off and the ascending tray 82B of the second tray 52# is lowered.

This ensures a space for storing the recording paper on which the front surface image has been formed. The timing chart shown in FIG. 48 shows an example of two-sided continuous paper feeding. The paper feeding operations in steps 6 to 11 and the image formation related operations in steps 15 to 18 are the same as in the continuous paper feeding mode, so a description thereof will be omitted. Thereafter, when the leading edge of the recording paper on which the front image has been formed leaves the fixing bag W38, the double-sided switching solenoid is turned on (step 19), and the two successively fed recording papers are guided to the return path 44.

Next, the paper is conveyed to the reversing path 45 by rollers 47 . When the first sheet of recording paper is guided to the reversing roller 48, the forward/reverse reversing motor is already rotating at high speed in the forward rotation side (feeding side to the reversing tray 45a) (step 21), and the first sheet of recording paper is quickly fed by the reversing roller 4B. It will be done. Next, when the leading edge of the second sheet of recording paper is detected by the reversal sensor 125 (step 20), the forward/reverse reversal motor is reversed at high speed (step 21). In synchronization with this, turn on the reversal switching solenoid (step 22)
. The reverse rotation operation is performed until the rear end of the first sheet of recording paper passes the reversal roller 48, and then the rotation operation is switched to the normal rotation operation.

In this way, the second recording paper is also guided onto the inverted PB) ray, and if this is the final recording paper, a reversal operation is performed by the timer count, and the recording paper is stored in the second tray 52''. .Here, (linear speed of reversing roller 48)>(
The relationship of (linear velocity of roller 47) and (linear velocity of reversing roller 48) - (linear velocity of roller 49) is ensured.

This time, a paper feeding operation is performed to form an image on the back side of the second loop 52#. The back paper feeding operation is basically the same as the front paper feeding operation, but the difference is that the powder clutch 119B is
At the same time as N (step 13), the pulse output (step 14) to the tray motor 122B is made equal to the number of pulses given in the initial paper feeding operation, so that the tray can rise from the landing position and perform the paper feeding operation. . The subsequent image formation on the back side is the same as in the continuous paper feeding mode.

[Continuous page continuous copy duplex mode] The continuous page continuous copy duplex mode is selected using the page continuous copy key and the duplex key in the operation section 600 shown in FIG. 33. Similar to book manuscripts, this is a mode in which images are formed so that the front and back sides are in the same relationship. Two sheets of recording paper are continuously fed and conveyed to copy pages 1 and 2 of the book manuscript, the first page is copied to the first recording paper, the second page is copied to the next recording paper, The first page is ejected as is, and the recording paper on which the second page was copied is reversed and then
It is stored in tray 52#.

The recording paper stored in this second tray 52'' is fed to the back side to copy the third page of the original, and then new recording paper is continuously fed to copy the fourth page of the original. The recording paper on which the third page has been copied is ejected as is, and the recording paper on which the fourth page has been copied is reversed and transferred to the second tray 52 in the same way as the second page.
This is then repeated. Therefore, in this mode, there is a limit to the number of sheets that can be stored.
From paper feed port to transfer belt, return path, reversal path, second tray 5
The distance is determined by the number of sheets of recording paper on the conveyance path up to 2". In this example, the distance is 4 sheets for A4 and 2 sheets for A3, and the number of sheets to be placed is determined by this. In other words, Depending on the recording paper size, the possibility of continuous page copying for both apparatuses is detected.This is carried out according to the flowchart shown in FIG.

First, it is determined whether the page continuous copy duplex mode is entered using the flag, and after comparing the set value for the number of sheets to be set depending on the recording paper size, if it is greater than the set value, an error message is displayed and the number of sheets to be set is set to be less than the set value. Display instructions.

If the set value is met, the display is canceled and the pudding switch is turned on. When the SW is turned on, the operation is performed according to the timing chart shown in FIG. 49. The 49th concave is when paper is fed and conveyed only from the second tray 52', and the first continuous recording paper is ejected, and the second
Steps 19.20.21. for loading into tray 52''.
The operations shown in 22 are performed. After that, the operation will be the same as in continuous duplex mode.

[Thick paper mode] When the cardboard key is pressed on the operation unit, a reception interrupt occurs on the main control side. Here, the cardboard flag is set. Attraction voltage setting is performed in the pulse operation blue routine group of the main flowchart. A flowchart for setting the attraction voltage is shown in FIG. First, determine whether the cardboard flag is set, and if it is set, turn on the signal line for switching the adsorption voltage of the voltage power supply (A).
The voltage level is set to a high voltage level suitable for absorbing cardboard. If the flag is not set, the signal line is OFF and has a high voltage level suitable for normal plain paper suction.

[Replenishment mode]

When the replenishment key is pressed from the operation unit, a reception interrupt is generated on the main control side. Here, a replenishment flag is set. Replenishment processing is performed in the blue routine group outside the pulse operation of the main flowchart. A flowchart of the replenishment process is shown in FIG. First, the number d of sheets to be replenished to the first tray 52' is calculated. After that, the replenishment solenoid is turned on and paper is fed from the paper bank side.

When the number of sheets actually fed exceeds d, the replenishment process is terminated.

[Receiving and passing the recording paper from the paper bank side] The receiving and passing of the recording paper from the paper bank to the main body side is carried out smoothly by making the conveyance speed of the conveyor belt and the PB belt equal, without any slack or tension. I can do it. For example, if the speed of Seido Held 53 on the main body side is 120 tyn/se
c, the linear velocity of the PB held 218 is set to 120 m/
This can be achieved by setting it to sec. However, in this example, in order to increase productivity on the paper bank side, the linear speed of the PB belt was increased by 1.
A case where the speed is 30 en/sec will be explained.

(PB belt linear speed)> (transport heddle linear speed), the first
When passing the recording paper from the PB heald 218 to the conveyor belt, the driven roller 55 is moved from left to right in FIG. 2, so that the conveyor belt and the recording paper come into contact with each other at an apparent upward position with zero relative speed. and is attracted by the charge pattern,
After being transported, the receiver completes the delivery. A timing chart showing this situation is shown in FIG. When recording paper is conveyed from the paper bank side, the paper bank paper feed sensor (PB paper feed sensor) I39 turns ONL, and the receiving and passing operations are performed based on this. Also, a pulse is output to the roller moving motor, and the roller moving motor is rotated forward and backward. This pulse frequency is based on the linear velocity difference between the conveyor belt and the PB held of 10/5ec (130m/sec -12Ora).
It is sufficient to give a pulse frequency of the speed at which the roller moves in m/sec). Further, the number of pulses at this time may be given as many as necessary to retreat to the home position detected by the home sensor. After retreating to the home position, a pulse is given on the CW side.

As a result, the recording paper and the conveyor heald come into contact with each other, and the paper is received and handed over. After that, the tip is detected by a registration sensor. This determines subsequent timing related to image formation.

In Figure 50, the two receivers show the timing of transfer. After the first transfer is completed, the moving roller is switched to CCW to return it to the initial position, and the number of pulses is the same as before. However, the carrier frequency is set to a somewhat higher frequency in order to increase productivity.

The first tray 52' and the second tray 52 in the copying main body 3
The paper feeding operation during various copying operations performed by feeding paper from the paper bank device 4 is as described above.On the other hand, when the copying machine operates by feeding recording paper from the paper bank device 4, the operation is as follows. be.

Paper bank 4 is 1st PB) Ray 201 to 4th PB
) The tray 204 is equipped with tray opening/closing sensors 261 to 634 that detect opening/closing of each tray. When the opening/closing operation of each PB tray is detected, it is assumed that the PB tray has been replenished with paper, and the following initial operation is performed.

In Paper Bank iW4, each PB) Ray 201-204
is fixed in position, and one movable paper feeding unit 7 feeds the paper from the corresponding PB) lay. Even if the remaining amount of paper on the PB) tray changes due to feeding, the paper position according to the remaining amount of paper is memorized so that the paper feeding position, that is, the position of the topmost paper does not change, and the paper position is set to the paper feeding position. A high speed PB) ray changing means is provided for matching.

1st PB) Ray 201 to 4th PBl - PB that was first selected to feed paper after detecting the opening/closing of each of Ray 204)
The paper feed unit 220 is moved vertically by the paper bank unit Jl device [t+ motor 251] to the uppermost point of the tray. Here, the highest point of each PB) ray is 1st FBI-ray 201 to 3rd PB) ray 203 with a maximum load of 250 sheets, or 4th PE) ray 204.
5 from the height when the maximum number of sheets loaded is 2000 sheets.
About TIMn above, the first to third PB) rays are located 30 m1 from the bottom plate, and the fourth PB tray is located 205 pixels from the bottom plate, and this position is taken as the home position of each PB) ray. The upper and lower home positions of the paper feed unit 220 are the first FB) lay 20 at the top.
The position is the same as the home position of No. 1, and the position is controlled downward from there by the stepping motor according to the number of pulses. At this time, the vertical movement speed of the paper feeding unit 220 is, for example, 150 tm/sec, and the sheet feeding unit 220 moves vertically by forward and reverse rotation of the stepping motor. From the home position of each PBI-ray, the paper feed unit 220 is the paper feed unit 2.
The PB belt lands until it is detected by the top edge detection sensor 233 provided in the paper 20, and the PB belt is
Stops at a position above Wm. Then, the paper feeding operation is repeated with this position as the home position for nine paper feeding operations.

Selection PB) Even if the lay is changed, the paper feed unit 22 is always
The paper feed position information of 0 is determined by the main control board 401 as the amount of pulses from the home position of the stepping motor.
The data is stored in non-volatile RAM within the memory. In addition, this makes it possible to determine the amount of paper remaining in each PB) ray. Then, this position is set as the initial position at which the paper feeding unit 220 starts feeding paper next time. If it is selected again, the paper feed unit 220
is the point 5 points above the top edge of the stacked sheets below the home position of the PB tray, and the paper feed unit 22
It moves directly to the position detected by the paper top end sensor attached to the top end of the paper, and repeats the paper feeding operation using that position as the home position of the paper feeding operation. As a result, even when the remaining amount of paper is small, the selection of the PB tray can be quickly changed.

Furthermore, when the paper is no longer detected by the paper top edge detection sensor 233 at the home position of the paper feeding operation during continuous paper feeding, the paper feed unit drive motor 251 feeds the paper until the paper is detected by the paper top edge detection sensor 233. Unisito 22
Move 0 downward and repeat paper feeding. As described above, as paper feeding progresses, the paper feeding unit 220 moves downward and repeats the process of feeding paper from a fixed PB) lay.

The operation of paper feed selection is shown in the flowchart of FIG. When a PB tray is selected based on paper selection, that PB
) Determine whether this is the first paper feeding after opening/closing the tray. If this is your first time, the remaining amount of paper is not known and the paper feeding position is not fixed, so the top position B of each PB tray is used, and from the second time onwards, the paper loading amount is already known, so the last paper feeding home position is set. The target position X of the paper feeding unit 220 is compared with the current position of the paper feeding unit 220, and the paper feeding unit 220 is moved up and down.

Here, the pickup roller 215 is already inside the paper feeding unit 220 in preparation for the vertical movement of the paper feeding unit 220.

When the paper feeding unit 220 reaches the target position, the pink up roller 215 is moved in the paper direction in preparation for paper feeding. Next, the paper upper end detection sensor 233 detects the upper end of the paper, and the paper feeding unit 220 moves to the paper feeding home position.
lower. From the second time onward, this operation is not performed since the paper feeding unit 220 has reached the last final paper feeding home position. At that time, the paper feeding home position is stored in the memory buffer D and used for the paper feeding operation. On the other hand, when the paper feed unit 7) 220 reaches the paper feeding home position, the print display is turned on and copying is started. Thereafter, the above-described second and subsequent operations are repeated during paper feeding, and the paper feeding unit 220 stores its position in the memory buffer D while descending.

The pink up roller 215 of the paper feed unit 220 pulls up the PB by a certain amount, e.g.
It is displaced together with the heald 218. On the other hand, when moving the paper feed unit 7) 220 in the vertical direction due to paper selection, the pickup roller 215 is moved to the right home position and retracted. The movement of the pink up roller 215 is from the home position detected by the PB pickup sensor 235 to the PB pickup attached to the paper feed unit 220.
This is done by the pickup drive motor 230. The PB pink-up drive motor 230 is a stepping motor, and its position is controlled according to the number of pulses.

Since the paper bank device 4 feeds paper from a fixed FB) ray with a paper feeding unit 220 that moves up and down, the paper feeding position differs depending on the separate installation of the PB) ray to be fed and the amount of paper loaded. The transport timing from the paper feeding timing to the main body is calculated as follows.

The PB heald 218 is conveyed at a constant speed of 130 m/sec by a PB belt drive motor 241, which is a stepping motor, and the paper after the operation of the PB heald variable speed motor 238 is conveyed at a speed of 130 m/sec. The conveyance distance changes depending on the vertical position of the paper feeding unit, and is determined by the number of steps N of the paper feeding unit 7 drive motor 251 from the home position. Since each step of the paper feeding unit drive motor 251 moves 0.2 strokes, the transport bus L of each PB) ray is expressed as L = N x 0.2 P. Here, P is a fixed distance depending on the PB tray, and from the 1st PB tray to the 3rd PB) lay, it is 200 km.
, 120 m+ for the fourth PB tray, and this difference is due to the horizontal transport distance. Therefore, the transport time T is expressed as T=L/130. The sum of the transport time T and the paper feeding time is the time required to feed the 1st sheet of paper, and continuous paper feeding from the 2nd sheet onwards is independent of the transport time. Furthermore, the paper feeding interval for continuous paper feeding is such that the paper feeding operation can be repeated at regular intervals, and printing of A4 size paper at 20 PPM can be performed repeatedly at 3 seconds/cycle.

The paper feeding operation will be explained based on the operation transition diagrams shown in FIGS. 28 and 29. Here, an example is shown in which the deceleration and stopping mechanism of the PB heald 218 uses two heald speed change rollers 216a and 216b. Also, in the 28th episode, the 1st PEF Ray 201~
3rd PB) In the case of paper feeding from the ray 203, FIG.
4th PB) This is the case of paper feeding from the ray 204.

The paper feed unit 220 is located at the upper part 5ffiI+ of the stacked paper below the home position of the PB tray, and the paper top edge sensor 2 attached to the paper feed unit 220
The paper feeding operation is repeated using the position detected at 23 as the home position of the paper feeding operation. At this time, pickup roller 2
15 and PB Held 218's Pink Unroller 215
The flat portion stretched between the roller 214 and the driven roller 214 is located 5 mm above the upper end of the paper stack. Next, the paper feed unit 22
The 0 pink unroller 215 is displaced along with the PB belt 218 by 100 degrees in the paper direction in order to attract the paper in the PB lay to the PB heald 218 during paper feeding.

PB) In order to attract the topmost sheet of paper to the PB heald 218, prior to feeding the paper, a charging roller 217 forms a charge pattern on the PB heald 218 in an amount corresponding to the paper size in synchronization with the paper feeding timing.

The paper feed unit 220 is lowered five degrees to bring the PB heald 21B into contact with the upper end of the paper. At this time, the aforementioned heald speed change roller 216 is used to operate so that the feeding speed of the PB heald 218 on the paper contacting surface is zero. This is done to improve the suction ability so that only the topmost recording paper of the stopped paper is attracted and transported.
It is also possible to reduce the conveyance speed of the belt 218 to a speed of 130 sec or less, bring it into contact, and carry it by suction.

When feeding paper from the 1st PB tray 201 to 3rd PB tray 203, the paper, that is, the recording paper, is attracted from the leading edge.
A belt speed change roller 21 is used to convey the paper in the horizontal direction.
6, the paper feeding unit 220 is raised to the home position of the paper feeding operation, which is 5 m above the paper, while keeping the feeding speed of the PB belt 218 on the paper contact surface at zero.

Thereafter, the curvature caused by the belt speed change roller 216 is released, and the P
The paper is conveyed by making the vertical conveyance movement portion of the B heddle 218 a straight line. At this time, the PB belt 218 moves at a constant speed of 130 m/sec by the PB heald drive motor 241.
The paper is transported at a constant speed.

The winding means of the belt speed change roller is operated between the continuously fed sheets where the conveyed paper has passed the belt speed change roller 216 to prepare for deceleration in the next sheet feeding process. At this time, the PB belt 218 on the paper feeding surface is accelerated, but it is not in contact with the paper and there is no problem.

On the other hand, when paper is fed from the 4th PB) lay 204, the paper is attracted from a position approximately 20 m from the leading edge, and the driven roller 2
In step 14, in order to convey the paper vertically, the heald variable speed roller 216 is used to first convey the paper horizontally to the left. That is, while the feeding speed of the paper contact area of the PB belt 218 is negative (moves in the opposite direction), the upper paper 5
The paper feeding unit 220 is raised to the home position of the paper feeding operation at the point IiI11. Based on the above, the 4th P.
In the case of the B tray 204, the PB held 218 extends to the leading edge of the paper.
Because the paper is attracted to the paper, feeding and transporting the paper can be performed stably.

The PB belt speed change motor 238 that rotates the belt speed change roller 216 is composed of a stepping motor, and main controls the timer value corresponding to the drive speed of the PB belt speed change motor 238 for each time in the heald speed change operation determined as described above. It is stored in the ROM in the board 401 in advance, and while recalling it, the speed control and forward/reverse control of the PB belt variable speed motor 238 are performed.

On the other hand, in preparation for deceleration in the next paper feeding process, the winding operation of the belt speed change mechanism between sheets of continuous feeding when the transported paper passes through the belt speed change roller 216 is normally performed with a paper distance of approximately 150++a for A4 size. Due to something, P
The B heel motor 238 may perform the winding operation at a constant speed.

Paper feeding operations in the 1st PB) ray 201 to 3rd PB) ray 203 are performed according to the timing chart shown in FIG. 52, for example, and paper feeding operations in the 4th PB) ray 204 are performed according to the timing chart shown in FIG. 53, for example. Figure 52 shows A3 size recording paper, and Figure 53 shows A3 size recording paper.
An example of paper feeding of recording paper of 4 horizontal size is shown.

In FIG. 52, the PB belt drive motor 241 is turned on.
Rotate at a constant speed. Next, the high-voltage power supply B that applies voltage to the charging roller 217 is operated in accordance with the paper feeding timing. This start timing is programmed in advance with a value calculated from the linear velocity as the position at which the charge pattern of the PB heald 218 is formed so that the charge pattern is formed upstream of the position at which the PB belt 218 is attracted.
In this example, this value is approximately 1.48 seconds before the suction operation, and this time differs only in the fourth PBL-ray 204.

Next, prior to the paper feeding operation, the PB heald variable speed motor 238 is rotated in the normal direction, and the heald variable speed roller 216 or the displacement roller 2
Move #16 and keep it on standby.

At the paper feeding timing, the paper feeding unit y H movement motor 25
1 in the forward direction, and at the same time, the PB heald variable speed motor 238 is rotated in the reverse direction at a high speed to bring the speed of the paper feed adsorption surface area of the PB heald 218 to zero, and the PB heald 218 is brought into contact with the upper surface of the paper. Moreover, the PB heald variable speed motor 238 is further reversed to retract the heald variable speed roller 216 or displacement roller 216'' to the left, and the PB heald 218 is vertically conveyed. PB provided
The paper feed sensor 139 detects this for approximately 3.2 seconds. Since the PB belt 218 accelerates and decelerates during the continuous operation period, the timing at which the operation of the high voltage power supply (B) 427 ends is the same as when it operates at a constant speed, which is 3.2 seconds.
Operates only during the ec period. Furthermore, when the linear velocity of the PB heald 218 at the charge pattern formation position changes, that is, when the
When the B heald variable speed motor 238 is operating, the PB heald 21
The high voltage power supply (B
) 427 to change the applied frequency. Since the last formed charge pattern becomes effective, when the linear velocity of the PB belt 218 at the charge pattern formation position is zero or less, the high voltage power supply (
B) The operation of 427 is optional and is turned off in this example.

In FIG. 53, the basic operation is the same as in FIG. 52. In the fourth PB tray 204, in order to cause the paper to be attracted to the leading edge of the paper by the PB health l-218, the suction surface of the PB belt 218 is displaced in the negative direction. 2
38 at higher speed, paper feeding surface linear speed -600m+
/sec. The operation timing of the high-voltage power supply (B) 427 is different from that of other PB) rays, so it is operated approximately 1.98 seconds before adsorption, and because it is A4 size, the PB belt 218 at the charge pattern formation position is operated.
stops operating while moving at high speed.

As a result of the above, the PB belt 21 has a length equal to the paper size.
The PB belt 218 can be attracted and conveyed to the charge pattern forming position No. 8 in a stopped state.

As the suction device, in addition to the method using the charge pattern described above, it is also possible to use an ordinary vacuum suction device depending on the case.

[Effects] According to the present invention, skewing during feeding and conveyance of a recording medium can be prevented without providing a registration means,
Furthermore, there is no need for double feeding, and a feeding and conveying device with extremely high conveyance reliability without occurrence of jams has been obtained.

According to the present invention, the recording medium can be fed in a constant and reliable state by changing the relative speed of the conveyance means near the storage means, without providing a separate registration device.
Skewing and jamming can be prevented, and the recording medium is transported at a constant speed near the image forming section and fixing section by the constant speed transport movement of the transport means, so that a constant and stable image is always formed. Image disturbances at the fixing section and fixing section were prevented.

According to the present invention, it is possible to reduce the frictional force exerted on the recording medium by the conveying means to zero or as much as possible, thereby suppressing the generation of paper dust, resulting in poor conveyance of the recording medium due to paper dust and poor image quality during image formation. A highly reliable feeding and conveying device was obtained.

According to the present invention, the feeding state of the recording medium from the storage means is always constant and reliable, and there is no need for a special recording medium conveyance state adjustment device or recording medium conveyance means in addition to the conveyance means, and the structure is simple. A low-cost feeding and conveying device was obtained.

According to the present invention, the entire endless conveyance movement speed from feeding from the storage means to the image forming section is not changed, and therefore, the copy production speed per unit time is not reduced, and the speed is always constant from the storage means. A feeding and conveying device capable of reliable feeding was obtained.

When a belt on which an alternating electric field is formed is used as the endless conveyance means, it becomes possible to stably and reliably attract the recording medium to the conveyance means, and there is no need to provide a special registration device.

By performing the return movement after the trailing end of the paper feed medium has passed through the additional movement device, it is possible to prevent external force from being applied to the recording medium during conveyance, and to reliably prevent all skew jams.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view of an example of an image forming apparatus according to the present invention, FIG. 2 is a schematic front view, FIG. 3 is a schematic explanatory view of a scanner device, and FIG. 4 is a plan view of a writing optical device. FIG. 5 is a plan view of the conveying means transmission, FIG. 6 is a perspective view of the B feeding means transmission, FIG. 7 is a front sectional view of a part of the storage means, and FIG.
7 is a front sectional view showing the partition means in a tilted state; FIG. 9 is a perspective view of the partition means; and FIG. 11 is a diagram corresponding to FIG. 10 showing the operating state of the conveying means pressing device, FIG. 12 is a perspective view showing the drive system of the conveying means pressing device, FIG. 13 is a front view of the cam, and FIG. The figure is an explanatory diagram of the stopper of the drive system of the conveying means pressing device, the first
5 is an overall perspective view of the storage means, FIG. 16 is a perspective view showing the drive system of the raising tray of the storage means, FIG. 17 is a schematic front view of the paper bank device, and FIG. 18 is a perspective view of the paper feed unit. , FIG. 19 is a plan view of the paper feeding unit, FIG. 20 is a perspective view of an example of the storage means, FIG. 21 is a perspective view of another example of the storage means, and 22M is an explanation of alternating electric field formation in the conveyance means. A perspective view, FIG. 23 is a front view explaining the formation of an alternating electric field, FIG. 24 is an explanatory diagram of a method of testing attraction force using an alternating electric field, and FIG. 25 shows the relationship between the pitch of the alternating electric field and the tensile force indicating the attraction force. 26 is a diagram showing the relationship between the applied voltage of the alternating electric field and the tensile force, and FIG. 27 is an explanatory diagram of another example of the conveying means transmission device.
Fig. 28 is an operation diagram showing the operating states of the conveying means transmission according to the 27th time sequentially by A, B, and C, and Fig. 29 is an example in which the relative positions of the conveying means and the storage means are different. FIG. 30 is an explanatory diagram of another example of the conveying means transmission, FIG. 31 is a diagram corresponding to FIG. 30 of an example in which the speed change step is modified from FIG. 30, and FIG. 32 is a diagram corresponding to FIG. Figure 33 is a partial diagram of the operation section, Figures 34-
Figure 43 is a diagram showing a flowchart, Figures 44-50.
The figure shows a time chart, FIG. 51 is a control flowchart of the paper bank device, and FIGS. 52 and 53 are time charts for the control shown in FIG. 51. 31... Image information holding means 34... Transfer charger (image forming section) 38... Fixing device 52... Accommodating means 53... Endless conveyance means 55... Followed roller 63... Additional Moving device 77
... Recording paper 3 Figure 4 Figure 7 Figure 20 Figure U4 Figure 24 Figure 25 Figure 26 kp U-1 [niVp P] 33

Claims (1)

[Claims] (1) In an image forming apparatus in which a recording medium fed from a storage means is transferred in an image forming section by an image information holding means and fixed in a fixing device, the means for attracting and conveying the recording medium is an endless conveying means, The endless conveyance means is configured to be able to convey the recording medium from the storage means to the fixing device via the image forming section, and the conveyance speed from the vicinity of the image forming section to the vicinity of the fixing device is always constant; 1. A feeding device for an image forming apparatus, characterized in that the speed is variable.