JP3116401B2 - Transfer device and electrophotographic recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the removal of paper when a paper jam occurs.
The present invention relates to a transfer device and an electrophotographic recording device which facilitate work .

[0002]

2. Description of the Related Art Conventionally, charging, exposure, and development are repeated a plurality of times to form a plurality of toner images of different colors in advance on an electrostatic image carrier (hereinafter referred to as a photoconductor). Various color electrophotographic recording devices that collectively transfer color images on a sheet) have been proposed.

FIG. 6 shows a conventional example of such a color electrophotographic recording apparatus. In the figure, 101 is a photoreceptor that rotates in the direction of the arrow, 102 is a corona charger that uniformly positively charges the surface of the photoreceptor 101, 103 is a laser beam, 104
Reference numerals 107 denote developing units in which yellow, magenta, cyan, and black toners are separately stored. Reference numeral 108 denotes a transfer device. The transfer device 108 includes a state in which a semiconductive belt 111 suspended by a roller 110 by a separation / contact driving mechanism 109 is partially pressed against the photoconductor 101 and a state in which the semiconductive belt 111 is separated from the photoconductor 101. It can be in two states and can move in the direction of the arrow at the same speed as the photoconductor. Reference numeral 112 denotes a transfer charger for transferring a negative high potential to the back surface of the sheet fed between the belt and the photosensitive member via the belt 111 to transfer the toner image on the photosensitive member to the sheet. Reference numeral 113 denotes a release lever for separating the transfer device from the photoconductor.

The operation of the thus configured color electrophotographic recording apparatus will be described below.

[0005] First, a photoreceptor 101 is charged by a corona charger 102.
Is positively charged, a yellow image signal is exposed by the laser beam light 103 to form an electrostatic latent image. Then, the electrostatic latent image is developed by the developing device 104 containing the yellow toner to form a yellow toner image on the photoconductor 101. At this time, the developing units 105 to 107 other than the yellow
1 are kept apart from each other. On the other hand, in the transfer device 108, the belt 111 is kept separated from the photoconductor 101 by the separation / contact driving mechanism 109, and the yellow toner image on the photoconductor is not disturbed.

Next, the charging, exposing, and developing steps are repeated for each of the colors magenta, cyan, and black in the same manner as when the yellow toner image is formed, and development with all the toner on the photosensitive member is completed. . During this time, the transfer device keeps the belt separated from the photoconductor.

When the development with all the toners is completed, the paper is fed out from a registration roller (not shown), and the transfer device 108 is operated by the separation / contact drive mechanism 109, and the roller 1
The belt rises with the axis of 10 as a fulcrum, and the belt is in light contact with and pressed against the photoconductor, and moves at the same speed as the photoconductor. Further, the transfer charger 112 applies a negative high potential to the back surface of the sheet fed between the belt and the photosensitive member via the belt, and transfers the toner image on the photosensitive member 101 to the sheet. The transferred sheet passes through a fixing device (not shown), and the toner is fixed by a heat roller and a pressure roller, and is discharged outside the apparatus.

FIG. 7 shows an example when the release lever 113 is operated. If a paper jam occurs, the release lever 113 is rotated in the direction of the arrow to separate the transfer device 108 from the photoconductor 101 with the support shaft 114 as a fulcrum, and a space is formed below the photoconductor to form a photoconductor. It is possible to remove the paper remaining in the lower body.

[0009]

However, in the above arrangement, the separation drive mechanism 109 for enabling the transfer device to be separated from and connected to the photosensitive member, and a release lever for releasing the transfer device during paper jam processing. The transfer mechanism 113 has a separate structure, and the frame structure for providing the separation / contact driving mechanism 109 in the frame of the transfer apparatus is complicated and large. For this reason, even when the transfer device is released when a paper jam occurs, a sufficiently large space cannot be obtained below the photosensitive member.
Removing the paper was difficult.

[0010] In addition, the cost of the entire transfer apparatus has been increased due to the complicated structure.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a transfer device and an electronic device which have a simple structure, can be miniaturized, and have a sufficiently large space below the photoreceptor when the transfer device is released during paper jam processing. It is intended to provide a photographic recording device .

[0012]

According to a first aspect of the present invention, there is provided a transfer device for transferring a toner image on an electrostatic image holding member onto transfer paper. In the step of performing the transfer, the separation / contact drive mechanism for maintaining the distance to the electrostatic image holding member at a transferable value, and increasing the distance to the electrostatic image holding member to a non-transferable distance in the step not contributing to the transfer. And a release lever for releasing a position of the transfer device with respect to the electrostatic image holding member from a predetermined position as necessary, and the separation / contact driving mechanism is provided in the release lever. . Further, according to the invention relating to an electrophotographic recording apparatus, in the developing step, the transfer means is separated from the electrostatic image holding member, and in the transferring step, the transferring means is pressed against the electrostatic image holding member. And a release lever that separates the transfer unit from the electrostatic image holding member more than the separation driving mechanism separates the transfer unit from the electrostatic image holding member. A drive mechanism is provided in the release lever .

[0013]

According to the present invention, since there is no need to provide a separation / contact drive mechanism in the frame of the transfer device with the above-described structure, and the size can be reduced by a simple structure, the lower portion of the photoreceptor can be removed when the transfer device is released during paper jam processing. It is possible to obtain a sufficient area.

[0014]

FIG. 1 is a front view showing the entire structure of a digital color copying machine to which the present invention is applied. The configuration and operation will be described below. Reference numeral 1 denotes a reading section of a digital color copying machine, which is mainly composed of a document table 2, a document illumination lamp 3, a lens 4,
It comprises a color line sensor 5, a drive system 6 for moving these for scanning in the sub-scanning direction, and an image processing circuit (not shown in this figure).

Reference numeral 10 denotes a writing unit of the digital color copying machine. Reference numeral 11 denotes a Se-based photosensitive member that is rotatably supported in the direction of arrow A. Reference numeral 12 denotes a corona charger for charging the surface of the photoconductor 11 to a predetermined positive potential, and reference numeral 26 denotes a laser beam. Reference numeral 20 denotes a laser optical unit, which is configured so that a laser beam 26 is emitted from a laser oscillation block 21 and scans the photoconductor 11 via a polygon scanner 22, a lens system 23, mirrors 24 and 25. A part of the scanning light of the laser beam system 26 is reflected by the mirror 27 and is irradiated on the start detection sensor 28. On the right side of the photoconductor 11, a developing device having a plurality of developing units and having a storage unit 30 for guiding the movement of each developing unit is arranged. The storage means 30 is detachable in the direction of the rotation axis of the photoconductor 11, and from the top along the circumference of the photoconductor 11, a Y developing unit 31 for developing yellow, an M developing unit 32 for developing magenta, a cyan developing unit, A C developing device 33 for development and a K developing device 34 for black development are mounted side by side in the vertical direction. Each developing device can take two positions, a position close to the photosensitive member 11 and a position away from the photosensitive member 11. The rotation of the eccentric cams 35-38 causes the rear portions of the developing devices 31-34 to rotate. When pressed, it moves in a substantially horizontal direction and comes close to the photoreceptor so that development is possible.

Reference numeral 50 denotes a paper feeding unit which can feed paper one by one from each of the cassettes 51 and 52 and the manual paper feeding unit 53. In this figure, when paper 56 is fed from the cassette 51, Is shown. The paper 56 is a registration roller 54
And is fed to the lower surface of the photoconductor 11. Reference numeral 60 denotes a transfer device, in which the belt 63 suspended by the rollers 61 and 62 is partially pressed against the photoconductor 11,
Arrow B
In the same direction as the outer peripheral surface of the photoconductor 11. This figure shows a state in which the transfer device is separated from the photoconductor 11. Reference numeral 68 denotes a release lever that can be rotated in the direction of arrow C to largely separate the transfer device from the photoconductor. Reference numeral 69 denotes a separation / contact driving mechanism, which is formed in the release lever 68 and includes a clutch, a gear, a cam, and the like. On the other hand, reference numeral 64 denotes a belt charger for transfer
To a negative high potential. A cleaning blade 65 for cleaning the toner remaining on the belt is provided with a collecting screw and a collecting box below the cleaning blade (not shown).

Reference numeral 67 denotes a separation charger for spraying a negative corona when the sheet 56 is separated from the belt 63. Reference numeral 70 denotes a fixing paper discharge unit, in which a heat roller 72 heated by a fixing lamp 71 and a pressure roller 73 are rotatable while being pressed against each other.
75 and a paper discharge tray 76 are provided.

Reference numeral 80 denotes a cleaner section which can take two states, a state in which it is lightly in contact with the photosensitive member 11 and a state in which it is separated from the photosensitive member 11.

The above is the outline of the overall configuration of the digital color copying machine to which the present invention is applied. Next, the operation will be described.

When a document is set on the document table 2 and the copy button is pressed, first, the document illumination lamp 3 is turned on to project an image of the document on a line on the color line sensor 5, and the color line sensor 5 scans the main line. A high-speed scan is repeatedly performed electrically in the direction (the depth direction on the paper), and the drive system 6 is moved in the sub-scanning direction (the right direction on the paper). In color copying, the sub-scanning of the original by the reading unit 1 is performed four times in one copy. First, in the first sub-scanning, the yellow signal output from the image processing circuit is input to the laser oscillation block 21 and Is irradiated with laser beam light 26 modulated according to a yellow signal. The main scanning of the laser beam light 26 on the photoconductor 11 is performed by the polygon scanner 22, and the sub-scanning is performed by the arrow A of the photoconductor 11.
The main scanning repetition timing and the main scanning repetition timing of the color line sensor 5 correspond to each other, and the peripheral speed of the photoconductor 11 and the moving speed of the color line sensor 5 in the sub scanning direction correspond to each other. Therefore, while reading the document, the laser beam light 26 corresponding to the yellow signal corresponding to each point of the document is simultaneously irradiated on the photoconductor 11 to form a latent image of the document.

At the time of the first sub-scan of the reading section 1, the developing section is set to the yellow developing state, and only the Y developing unit 31 approaches the photosensitive member 11 by the operation of the eccentric cam 35, and the other developing units Are in a separated state. Therefore, the latent image corresponding to the yellow signal formed by the laser beam light 26 is developed by the Y developing unit 31 with the yellow toner, and passes without being affected by other developing units. The image developed with the yellow toner reaches the transfer / conveyance unit as the photoreceptor 11 rotates.
9, the belt 63 is separated from the surface of the photoconductor 11, and the image passes without being disturbed. Further, the cleaner section 80 is also separated from the photoreceptor 11, and the yellow toner image passes without being disturbed and passes under the corona charger 12 again. The portion of the photoconductor 11 where the yellow toner image is formed is again charged from the toner by the corona charger 12.

When the leading end of the yellow toner image is recharged and comes again to the irradiation position of the laser beam light 26, the driving system 6 is controlled in the reading section 1 so that the color line sensor 5 starts scanning again from the starting end of the original. ing. In the second scanning of the reading unit 1, a magenta signal is input from the image processing circuit to the laser oscillation block 21, and the laser beam 26 is modulated according to the magenta signal and is exposed from above the yellow toner image on the photoconductor 11. . Since the leading edge of the image is aligned and the scanning speed is constant, the yellow toner image and the latent image based on the magenta signal are formed in position. The latent image formed by the magenta signal is developed only by the magenta toner and becomes a yellow toner image because only the M developing device 32 in the developing section is close to the photoconductor 11 and the other developing devices are separated. The images are superimposed.

Thereafter, similarly, recharging, latent image formation by cyan signal, cyan development, recharging, latent image formation by black signal, and black development are repeated. After the final black toner image is formed, the transfer / conveyance unit is lightly pressed against the photoconductor 11 by the separation / contact drive mechanism 69 immediately before the front end of the toner image reaches the transfer / conveyance unit, and the front end of the toner image is Paper 56
The sheet 56 is fed by the registration roller 54 so as to enter between the photoconductor 11 and the belt 63 at the timing when the leading edge of the sheet 56 coincides. While the toner image is transferred to the sheet 56 by the electric field generated by the belt charger 64, the sheet 5
6 is conveyed while adhering to the belt 63,
Since the curvature is large in the portion, the sheet is separated from the belt 63 and enters the fixing and discharging section 70. At this time, in order to prevent the toner image on the paper 56 from being disturbed by the peeling charge generated on the paper 56 for separating from the belt, the separation charger 67 is provided from above.
Sprinkle with a negative corona. The toner image on the sheet 56 passes through the fixing sheet discharging section 70 and is fixed on the sheet discharging tray 76 after being fixed.

On the other hand, the untransferred toner remaining on the photoreceptor 11 is positively charged by the pre-cleaner charger 81 which starts operation immediately before the leading end thereof approaches, and moves to a state of contacting the photoreceptor 11 almost simultaneously. Cleaner part 80
And is stored in the collection box 82 via a collection screw (not shown). The surface of the photoreceptor 11 is thereby cleaned, and at the same time, the charge is removed by the charge removing lamp 86, and the photosensitive member 11 is returned to the initial state, and the preparation for the next copy is completed. On the other hand, the toner slightly accumulated on the belt of the transfer device is the cleaning blade 6
5 is cleaned.

The above is the outline of the overall configuration and operation of the digital color copying machine to which the present invention is applied.

Next, the configuration and operation of the transfer device of the digital color copying machine will be described in detail. 2 is a front view of the transfer device 60 with the belt 63 separated from the surface of the photoconductor 11, FIG. 3 is a front view of the transfer device 60 with the belt 63 lightly pressed against the surface of the photoconductor 11, and FIG. Release lever 6
FIG. 5 is a view showing a main part of the transfer device 60 in a state where the shutter 8 is operated, and FIG.

When the copy start button is pressed while the belt 63 is lightly pressed against the surface of the photoreceptor 11 (the state shown in FIG. 3), the separation / drive gear (not shown) is rotated and the input gear 91 of the spring clutch 90 is rotated. Rotate. The control ring 92 of the spring clutch 90 has two projections 92a, 9 having a diagonal position, that is, a phase of 180 degrees, and shifted in the axial direction.
2b is formed, and a stopper 95 driven by a solenoid (not shown) abuts one of the protrusions 92a, 92b to prevent the output gear 96 from rotating. Output gear 9
A cam gear 97 is engaged with 6 via a gear train, and a cam 98 is fixed to the cam gear 97. Photoconductor 11
In the process in which each toner is developing, the stopper 95 contacts the projection 92a, and the bottom dead center of the cam 98 contacts the frame of the transfer device. As a result, the belt 63 is kept separated from the photoconductor 11. Next, a solenoid (not shown) is operated immediately before the end of the developing process and the leading end of the toner image reaches the transfer / conveying section, and the stopper 95 is moved.
Moves away from the protrusion 92a to the position of the protrusion 94 in the axial direction. The outer periphery of the boss 91a of the input gear 91 and the boss 96a of the output gear 96 are provided over the coil spring 9 over both.
3 are fitted, and the elastic force of the coil spring 93 is
The bosses 91a and 96a constantly act to tighten, and the tightening force causes the coil spring 93 to rotate integrally with the input gear 91. As a result, the torque of the input gear is transmitted to the output gear 96. However, since the one end 93a of the coil spring 93 is locked to the control ring 92, when the control ring 92 is fixed, the coil spring 93 stops rotating and the coil spring 9
Since the frictional force between the gear 3 and the boss 91a of the input gear acts in a direction to warm the tightening force of the coil spring 93, the torque of the input gear 91 is not transmitted to the output gear 96. On the other hand, since the other end 93b of the coil spring 93 is locked by the locking portion provided on the output gear 96, the output gear 96 stops while maintaining the same phase as the control ring 92.
That is, when the stopper 95 is in contact with the projections 92a and 92b, the control ring 92 is fixed, so that the rotational force of the input gear 91 is not transmitted to the output gear 96. However, while the stopper 95 moves away from the protrusion 92a in the axial direction toward the protrusion 92b, the control ring 92 is free, the spring clutch 90 rotates while transmitting the driving force to the output gear 96, and the protrusion 94 is Rotate 180 degrees until it touches 95. As a result, the output gear 96 stops at the position rotated by 180 degrees. Since the output gear 96 and the cam gear 97 have the same number of teeth, the cam 98 rotates 180 degrees and stops at the position where the top dead center is in contact with the frame of the transfer device. That is, the frame of the transfer device is pushed up by the stroke of the cam 98, and the belt 63 is lightly pressed against the photoconductor 11, so that the transfer is effectively performed. After the transfer is performed, the stopper 95 is again moved to the position of the protrusion 93 by the operation of the solenoid, the spring clutch 90 is rotated by 180 degrees, the cam 98 contacts the transfer frame at the bottom dead center, and the belt 63 is moved from the photoconductor 11. Separate.

During the operation of the copying machine, a paper jam occurs and the photoconductor 11
When it is necessary to remove the sheet remaining at the lower portion, the release lever 68 is rotated about the support shaft 99 in the direction of arrow C. The cam leaves the transfer device and the transfer device
With the shaft as a fulcrum, it descends by its own weight and reaches a position where it comes into contact with a stopper (not shown), and a sufficient space for removing paper jammed at the lower portion of the photoconductor 11 is obtained.

As described above, in this embodiment, the separation / contact drive mechanism 69 is provided in the release lever 68, and the output gear 96 of the spring clutch 90 and the cam gear 97 have the same number of teeth. There is no need to provide a drive,
The structure can be simplified, and a sufficient space can be obtained below the photoconductor 11 during paper jam processing.

[0030]

As described above, according to the present invention, it is possible to reduce the size with a simple structure, and to obtain a sufficiently large space below the photosensitive member when the transfer device is released during paper jam processing. It is possible to easily perform a paper jam processing operation. Further, since the transfer device can be configured with a simple structure, a low-cost transfer device can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing the overall configuration of a digital color copying machine to which the present invention is applied.

FIG. 2 is a front view of the transfer device with a belt separated from a photoconductor;

FIG. 3 is a front view of the transfer device in a lightly pressed state;

FIG. 4 is a front view of the transfer device in a state where a release lever is operated.

FIG. 5 is a cross-sectional view of the detachment drive mechanism.

FIG. 6 is a front view of a main part of a conventional color electrophotographic recording apparatus.

FIG. 7 is a diagram showing an operation state of a release lever in a conventional electrophotographic recording apparatus.

[Explanation of symbols]

 Reference Signs List 11 photoreceptor 60 transfer device 63 belt 68 release lever 69 detachment drive mechanism 90 spring clutch 96 output gear 97 cam gear 98 cam

Continuation of front page (56) References JP-A-2-73385 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/16 G03G 15/01 114 G03G 21/16

Claims (2)

(57) [Claims] 1. A transfer device for transferring a toner image on an electrostatic image holding member to transfer paper, wherein in the transferring step, the distance from the electrostatic image holding member is maintained at a transferable value, and the transfer is performed. In the step which does not contribute, while having a separation / contact drive mechanism for expanding the distance to the electrostatic image holding body to a distance where transfer is not possible, the position of the transfer device with respect to the electrostatic image holding body is shifted from a predetermined position as necessary. A transfer device having a release lever for releasing, and the separation / contact drive mechanism provided in the release lever. 2. A separation and drive mechanism in which the transfer means is separated from the electrostatic image holding member in the developing step and the transfer means is in pressure contact with the electrostatic image holding member in the transfer step. A release lever that separates the transfer unit from the electrostatic image holding member more than the mechanism separates the transfer unit from the electrostatic image holding member, and the separation / contact driving mechanism is provided in the release lever . An electrophotographic recording device characterized by the above-mentioned.