JP2942376B2 - Recording paper retraction acceleration mechanism for printers using continuous recording paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording paper retraction accelerating mechanism for a printer, which forms an image on continuous recording paper by using an electrophotographic method, and in which a transfer charger is retracted from a transfer operation position during standby for printing. About.

[0002]

2. Description of the Related Art Conventionally, a latent image is formed by exposing a photoreceptor on the surface of a photosensitive drum which is driven to rotate, toner is adhered to the latent image to develop (toner image), and the toner image is conveyed. 2. Description of the Related Art An image forming apparatus using a so-called electrophotographic method is known in which a recording medium is transferred onto a recording sheet conveyed at the same speed as the rotation speed of a photosensitive drum by a driving unit, and is fixed by a fixing device and discharged. As one of them, there is an electrophotographic printer which forms an image on a foldable continuous paper having a perforated hole called so-called fan-hold paper which is the same as that used in a conventional line printer or the like. The fan hold paper is configured to be cuttable with perforations at each page, and is supplied in a stacked state alternately folded in the reverse direction at the perforations.

In a printer using continuous paper as recording paper, printing must be started from a fixed position from a perforation of continuous paper (that is, the upper end of a page). Exposure / development / transfer action parts are arranged around the photosensitive drum to perform various actions with the rotation of the photosensitive drum, and the exposure part of the photosensitive drum is transferred to the transfer position by the rotation of the photosensitive drum. Therefore, in order to make the exposure start portion coincide with a certain position from the perforation of the continuous paper at the start of printing (that is, to start printing from a certain position from the perforation), the sewing of the continuous paper must be performed. The printer waits for printing with the eye area near the transfer position (stops feeding of continuous paper), and moves (rotates) the photosensitive drum relative to the continuous paper before printing starts to adjust the printing start position. To (the so-called head to out) there is a need.

If the continuous paper is kept in contact with the photosensitive drum (transfer operation state) at the time of cueing, the photosensitive member on the surface of the photosensitive drum is damaged or worn to shorten the life of the photosensitive drum. In addition, there is a problem that the continuous paper is stained with residual toner on the surface of the photosensitive drum (toner adheres to a streak-like contact portion along the longitudinal direction of the photosensitive drum to form a so-called black streak). For this reason, the present applicant has previously proposed a configuration in which the transfer charger can be separated from the photosensitive drum, and the transfer charger is retracted from the transfer operation position (separated from the photosensitive drum) during printing standby. The retraction of the transfer charger is performed in synchronization with the stoppage of the continuous paper conveyance at the end of printing.

[0005]

However, as described above, even when the transfer charger is separated from the photosensitive drum at the end of printing (during standby for printing) and the conveyance of the continuous paper is stopped, the transfer of the continuous paper is stopped. Since the paper is usually conveyed by the conveyance means provided on the front side in the conveyance direction from the photosensitive drum, the continuous paper conveyed at a constant speed until immediately before the end of printing cannot be stopped instantaneously, However, even if the transfer charger retreats, the important continuous paper does not retreat and keeps in contact with the photoreceptor drum, and as a result, becomes dirty when printing is resumed (black). Streaks). This problem is particularly remarkable when the continuous paper positioned near the transfer position in the printing standby state (when the continuous paper is stopped) is in the direction of protruding toward the photosensitive drum (so-called mountain fold). or,
In particular, during the winter season when the humidity is low, the continuous paper may be attracted to the photosensitive drum by static electricity.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a recording paper retreat acceleration mechanism for a printer using continuous recording paper which can reliably retreat the continuous paper from a photosensitive drum during printing standby. And

[0007]

In order to achieve the above object, a recording paper retreat accelerating mechanism for a printer using continuous recording paper according to the present invention comprises a photosensitive drum on a conveying path of the continuous recording paper from a photosensitive drum to a transfer portion. On the side, a tension member having a predetermined weight is swingably supported by an arm member or the like, and is installed so as to be vertically movable, and the tension member is placed on the continuous recording paper conveyed by its own weight. The configuration is as follows. Further, the printer includes an opening / closing member, and the opening / closing member or a lock mechanism of the opening / closing member can be interlocked with a tension member via an interlocking mechanism, so that the tension member retracts upward with the opening of the opening / closing member. It is composed.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a laser beam printer apparatus using fan-hold paper, which is continuous paper, as recording paper, and prints and outputs character information input from a computer or the like to fan-hold paper 20 by electrophotography. Around the photosensitive drum 1, a toner cleaning unit 2, a static elimination unit 3, a charging unit 4, a scanning optical system 5 for guiding a laser beam onto the photosensitive drum 1, a developing unit 6, and a transfer unit 7, respectively, rotate the photosensitive drum 1. The fixing unit 8 is disposed in the conveying direction of the fan-hold paper 20 in the conveying direction of the fan-hold paper 20, and the fan-hold paper is arranged in the conveyance path of the fan-hold paper 20 from the photosensitive drum 1 to the fixing unit 8. The tractor 9 is a transport mechanism that transports and drives the paper 20. Then, while the photosensitive drum 1 is rotationally driven (sub-scanning), the surface thereof is main-scanned (exposed) by a laser beam from the scanning optical system 5 in the direction of rotation to form an electrostatic latent image, and the latent image is developed. The toner is adhered to a toner image in a section 6 (development), and the toner image is transferred to a fan-hold sheet 20 by a transfer section 7 and the toner image is fixed on the fan-hold sheet 20 by a fixing section 8. Output. The tractor 9 has a tractor belt 91 having a projection that fits into a feed hole at a side end of the fan hold paper 20.
Are arranged so that their orbits coincide with the transport path of the fan-hold paper 20, and a drive source (not shown) (not shown)
Thus, the photosensitive drum 1 can be driven to rotate at a rotational speed equal to the rotational peripheral speed thereof.

As shown in an enlarged view of FIG. 2, the transfer section 7 includes a corona charger 71 and brackets 3 provided at both ends thereof on the chassis 30 of the laser beam printer.
An arm 72 pivotally supported by a fulcrum 73 at a position 1 supports the photosensitive drum 1 in a parallel and retractable manner. The arm 72 is connected to the lower surface of the arm 72 and the chassis 3.
The corona charger 71 is urged to swing by a spring 75 interposed between the photosensitive drum 1 and a predetermined position where the corona charger 71 performs a transfer operation on the photosensitive drum 1.
A pressing member 76 having a semicircular cross section is mounted on the arm 72 on the tip side (the side on which the fan hold paper 20 is introduced) from the holding position of the corona charger 71, and when the corona charger 71 is at the transfer operation position. The pressing member 76 presses the fan-hold paper 20 against the photosensitive drum 1 so that the fan-hold paper 20 comes into close contact with the photosensitive drum 1. At the same fulcrum 73 where the arm 72 is pivotally supported,
A paper holder 74 having a lever portion 74A protruding from the lower surface is pivotally supported pivotally, and a slide plate 32 is mounted on the chassis 30 of the laser beam printer by a driving means (not shown). Is provided so as to be slidable in a direction parallel to the carrying direction of the camera. When the slide plate 32 is slid in the discharge direction of the fan-hold paper 20, the operating portion 32A vertically formed at the end of the fan-hold paper 20 introduction side is moved to the lever 74A of the paper presser 74. The paper presser 74 is pivotally driven clockwise in the figure by operating a pin 77 which is horizontally implanted in the arm, and the arm 72 swings against the urging force of the spring 75 by the swing of the paper presser 74. Dynamic drive,
As shown in FIG. 3, the corona charger 71 is retracted downward from the transfer operation position in the figure.

A paper slack lever 10 as a tension member is disposed on the side of the transfer unit 7 on the side of the fan hold paper 20 introduction side (right side in the figure). The paper slack lever 10 is a shaft 11 having a circular cross section and being longer than the width of the fan hold paper 20.
Are pivotally supported on a frame (not shown) of the laser beam printer device via arms 12 fixed to both ends thereof. And the fan hold paper 20
Is set, the shaft 11 is placed on the fan hold paper 20, and the tension is applied to the fan hold unit 20 by the weight of the paper slack lever 10. . The shaft 11
May be rotatably supported by the arm 12, so that the resistance applied to the conveyance of the fan hold paper 20 can be reduced.

As shown in FIG. 1, the upper portion of the laser beam printer is covered with a clam shell 40 as an opening / closing member. It is supposed to do it. The clamshell 40 is swingably mounted with its lower rear portion as a fulcrum 41, and its tip end side (front side of the apparatus) is pivotally supported by a frame on the main body side of the laser beam printer apparatus. The lock lever 13 (not shown in FIG. 1) is locked in a closed state.

The lock lever 13 has a substantially U-shape. A hook portion 13A is formed at one end, and an operation portion 13B for operating a lever 14, which will be described later, is formed at the other end. The hook 13A is pivotally supported by the frame on the main body side of the laser beam printer device in the vicinity of the bending portion with the portion 13A as the upper side.
The clam shell 40 is kept closed by engaging with an engaging pin (not shown). The lock of the clamshell by the lock lever 13 is released by swinging the lock lever 13 in a direction indicated by an arrow in FIG. 2 as indicated by an imaginary line. The lock lever 13 and the above-described paper slack lever 10 are operatively connected via a plurality of levers 14 and 15 as an interlocking mechanism, and the lock release swing of the lock lever 13 when the clam shell 40 is opened. , The paper slack lever 10 is pivoted.

Both levers 14 and 15 are connected to one lever 14
Corresponding to the end of the other lever 15 above one end of
The other end of the lever 14 is pivotally attached to the frame at a position near the center.
B corresponds to the lower side, and the end and the operating portion 13B are connected by a spring 16 so that both ends are in a contact state, and the other end is also connected to the end of the lever 15 by a spring 17 and abuts. It is linked. The other end of the lever 15 is located below the arm 12 of the paper slack lever 10. The end of the lever 15 and the arm 12 of the paper slack lever 10 are
When the clamshell 40 is locked by 3A and the fan-hold paper 20 is set, FIG.
3 or at the time of standby for printing shown in FIG. 3 (when the transfer unit 7 swings and retracts), the fan hold paper 20 of the shaft 11 of the paper slack lever 10 is provided with a predetermined interval.
When the levers 14 and 15 are swingably driven by swinging of the lock lever 13 at the time of releasing the lock of the clamshell, the end of the lever 15 becomes the arm of the paper slack lever 10. The shaft 11 is set in such a positional relationship that the shaft 11 is retracted upward from the state in which the shaft 11 is placed on the fan hold paper 20 by contacting the shaft 12 and pushing it upward.

According to the above configuration, when printing is performed with the corona charger 71 at the transfer operation position, the shaft 11 of the paper slack lever 10 is placed on the fan hold paper 20 introduced into the transfer unit 7. State, fan hold paper 2
0 is given a tension due to the weight of the paper slack lever 10. At the end of printing (at the time of printing standby), the conveyance of the fan hold paper 20 is stopped, and the slide plate 32 is stopped.
Are slid by the driving means (not shown) toward the discharge direction of the fan-hold paper 20, the arm 72 is oscillated, and the corona charger 71 is retracted from the transfer operation position. The fan hold paper 20 is loosened between the photosensitive drum 1 and the corona charger 71 due to the release of the pressing to the side and the inertia due to the sudden stop of the conveyance at a constant speed.
At this time, since the paper slack lever 10 is placed on the fan hold paper 20, it swings downward according to the looseness of the fan hold paper 20 due to its own weight, and the fan hold paper 2
The slack direction of 0 is downward (that is, the side away from the photosensitive drum 1).
And the tension is continuously applied to the fan hold paper 20. Therefore, it is possible to surely prevent the fan hold paper 20 from being in contact with the photosensitive drum 1 but the contact portion is stained (black streaks) when printing is resumed, although the corona charger 71 is retracted. When the end of the fan hold paper 20 passes below the paper slack lever 10 (that is, the set fan hold paper 20 ends), the paper slack lever 10 swings downward as much as possible. However, in this state, the setting of a new fan hold sheet 20 is obstructed. In this configuration, when the lock lever 13 is rocked to open the clamshell when the fan hold paper 20 is set and the lock is released, the rocking of the lock lever 13 causes the lever 14,
The paper slack lever 10 is swingably driven through the shaft 15 so that the shaft 11 is directed upward, so that the fan hold paper 20 can be easily set.

Next, another embodiment of the present invention shown in FIG. 4 will be described. This embodiment is different from the above embodiment in that the fan hold paper 2
While the tension member (paper slack lever 10) is configured to swing upward in conjunction with the release swing of the lock lever 13 that locks the clam shell 40 when set to 0, the swing of the clam shell 40 is changed. The tension member is configured to swing upward and retreat in conjunction with the movement itself. The figure shows the clamshell open,
Working parts such as a developing part are also omitted from the drawing. In the figure, portions having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

On the side of the photosensitive drum 1 where the fan hold paper 20 is introduced, two upper and lower guide slopes 51 and 52 are supported on both sides by a support portion 33 in which the side end of the chassis 30 is bent upright. Are set apart from each other for a predetermined period.
The fan hold paper 20 introduced from outside of the apparatus is regulated (guided) up and down by the guide plates 51 and 52 so as to reach the photosensitive drum 1. That is, the recording paper transport path is formed by the upper and lower guide plates 51 and 52. At the end of the upper guide plate 51 on the photosensitive drum 1 side, two lever support portions 51A, 51
A is bent upright.
A paper slack lever 10 'is swingably supported at 1A. The paper slack lever 10 'has two arms 12', 1
The end of 2 'is connected by a semi-cylindrical connecting part 11' having a semicircular lower surface, and an operating arm 18 of a predetermined length is parallel to the connecting rod from the base end of one arm 12 '. An operation plate 18A is formed integrally with synthetic resin so as to protrude parallel to the arm 12 'at the distal end of the operation arm 18 and extends toward the side of the device. On the flat upper surface, a metal weight 19 having a predetermined weight is fixed by caulking by hot stamping, and the opposing sides of the base ends of the arms 12 ', 12' are respectively lever supporting portions 51A, 51A. And is swingably mounted around the fitting portion.

An interlocking mechanism 60 is provided on the inner surface of the side panel 42 of the apparatus main body facing the operation arm 18 of the paper slack lever 10 '. The interlocking mechanism 60 supports the push rod 61 so as to be slidable up and down by two guide projections 43 and 44 projecting up and down from the inner surface of the side panel 42 at predetermined intervals. When the E-ring 62 engaged with the intermediate portion sandwiched between 43 and 44 and the lower guide protrusion 44 are interposed between the push rod 61 and the
And a pin 64 at the lower end of the push rod 61.
Is projected and mounted toward the inside of the apparatus. The pin 64 is located below the operation plate 18A protruding from the operation arm 18 of the paper slack lever 10 '.
As a result, the paper slack lever 10 'can be swung by contact with the lower surface of the operation plate 18A.

Here, when the clamshell (not shown) is opened and not present on the upper side as shown in FIG.
1 is moved upward by the urging force of the spring 63, and the pin 64 pushes the operation plate 18A upward to swing the paper slack lever 10 'to the side where the connecting portion 11' is located upward. 11 ′ floats from the upper surface of the fan hold paper 20, and the upper end of the push rod 61 projects a predetermined amount above the upper guide projection 43. On the other hand, when the clamshell is closed from the state in which the clamshell is opened, the operating portion of the clamshell (not shown) abuts on the upper end of the push rod 61 and the push rod 61
Is pressed downward, whereby the position of the pin 64 is lowered, and the paper slack lever 10 ′ swings to the side with the connecting portion 11 ′ downward, and when the clamshell is closed and locked, As shown by the line, the connecting portion of the paper slack lever 10 'is placed on the fan hold paper 20, and as a result, the paper slack lever 10' is attached to the fan hold paper 20.
The tension is applied by the weight of the weight 19 (that is, the weight 19). At this time, the pin 64 at the lower end of the push rod 61 is set below the lower surface of the operation plate 18A so as not to hinder the tension application to the fan hold paper 20 by the paper slack lever 10 '. Is what it is.

Thus, also in this configuration, the connection portion 11 'of the paper slack lever 10' is placed on the fan hold paper 20 which reaches the transfer position with the photosensitive drum 1, as in the above-described embodiment. In this state, the looseness of the fan-hold paper 20 caused by the retreat of the corona charger from the transfer operation position is regulated to the lower side by the paper slack lever 10 'to prevent black streaks from occurring on the fan-hold paper 20 when printing is resumed. When the clamshell is opened when setting the fan hold paper 20, the paper slack lever 1
0 'swings with the connecting portion 11' on the upper side so that the fan hold paper 20 can be set easily. In the above embodiment, the paper slack lever 10 'is constructed by integrally forming the arms 12', 12 'and the connecting portion 11' and attaching the weight 19 to the connecting portion 11 '. Arm 12 ', 1 as a column of weight
2 'may be rotatably supported, so that the resistance applied to the conveyance of the fan hold paper 20 can be reduced.

[0020]

As described above, according to the recording paper retreat accelerating mechanism of the printer using continuous recording paper according to the present invention,
When the transfer charger retracts from the transfer operation position, even if the continuous paper is loosened at the position corresponding to the transfer section, the loosening direction can be regulated in the direction away from the photosensitive drum, and the continuous paper can be securely removed from the photosensitive drum during printing standby. Evacuation and separation. Therefore, it is possible to prevent the loose continuous paper from being kept in contact with the photosensitive drum and becoming dirty when printing is resumed.

[Brief description of the drawings]

FIG. 1 is a side view showing a schematic configuration of a printer provided with an embodiment of a recording paper retreat accelerating mechanism of a printer using continuous recording paper according to the present invention.

FIG. 2 is a partially enlarged view of a transfer unit in FIG. 1;

FIG. 3 is a diagram showing a state in which a transfer charger is retracted from the state of FIG. 2;

FIG. 4 is a perspective view showing a schematic configuration of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum 10, 10 '... Paper slack lever 11 ... Shaft (tension member) 11' ... Connection part (tension member) 12, 12 '... Arm (arm member) 14, 15 ... Lever (interlocking mechanism) 20 ... Fan Hold paper (continuous recording paper) 40 ... Clam shell (opening / closing member) 60 ... Interlocking mechanism 71 ... Corona charger (transfer charger)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 15/16 B65H 23/16 B41J 15/04

Claims (4)

(57) [Claims] An image is formed on continuous recording paper by using an electrophotographic method, and a transfer charger is retracted from a transfer operation position in a printing standby state. A tension member having a predetermined weight is vertically movably installed on the photosensitive drum side of the continuous recording paper conveyance path, and the tension member is mounted on the continuous recording paper to be conveyed by its own weight. A recording paper evacuation promotion mechanism for a printer using continuous recording paper. 2. The tension member is swingably supported by an arm member and is vertically movable.
2. A recording paper retreat accelerating mechanism for a printer using continuous recording paper according to claim 1, wherein: 3. The printer has an opening / closing member, wherein the opening / closing member and the tension member can be interlocked via an interlocking mechanism, and the tension member is retracted upward with the opening of the opening / closing member. 3. A recording paper retreat accelerating mechanism for a printer using continuous recording paper according to claim 1 or 2, wherein 4. The printer has an opening / closing member, wherein a locking mechanism of the opening / closing member and the tension member can be interlocked via an interlocking mechanism, and the tension member is retracted upward by operating the locking mechanism. 3. The recording paper retreat accelerating mechanism of a printer using continuous recording paper according to claim 1, wherein