JPH066382Y2 - Conveyor transfer device - Google Patents

Description

[Detailed Description of the Invention] Industrial field of application The present invention conveys an image to a transfer unit such as electrophotography and magnetography without using a grip for holding the paper and a roller group for suppressing the paper. The present invention relates to a transport transfer device capable of performing.

2. Description of the Related Art In a conventional transfer transfer device, as shown in FIG. 2, for example, an electrostatic latent image is formed on a surface of a photosensitive drum (image carrier) 1 uniformly charged by a charging corotron 14 by exposing an optical system 15. The electrostatic latent image is subjected to black-and-white development or color development by the developing device 16, and the developed image is transferred onto the sheet by the transfer corotron 3 at the transfer position.

This paper is wound around the surface of the transfer drum 2 while being sandwiched by the gripper 8, and in the case of black and white development, the peeling claw 1
After being separated by 1, the sheet is conveyed to a discharge tray (not shown) through the conveying path 12. If the paper has the color development image transferred, it is peeled off by the peeling claw 11 and conveyed to the conveyance path 12 after the completion of the entire transfer process. In the middle of the transfer process, the paper is brought into close contact with the transfer drum 12 by the paper pressing rollers 7c, 7d, 7e, 7a, and 7b, and the next color development image is transferred by the transfer corotron 3 in the next transfer process. After the transfer process of (1) is completed, it is peeled off by the peeling claw 11 and sent to the conveyance path 12.

A large number of sheets of a desired size are placed on the sheet feeding cassette 5 before transfer, and the uppermost sheet of these sheets is sent out by the sheet feeding roll 6 and is transferred to the transfer drum 2 by the sheet pressing roller 7a. It is wound and is fed to the transfer portion through the paper pressing roller 7b while being uniformly charged by the charging corotron 9. Then, as described above, in the case of the paper on which the black and white developed image has been transferred, the electric field on the paper is removed by the static elimination corotron 10, and then the paper is peeled off by the peeling claw 11, and the paper is sent to the transport path 12.

The case where a color development image is transferred will be described in detail. In the optical system, three types of filters are switched for each exposure, and a developing machine having a toner color corresponding to the type of the filter is selected for each exposure, and the exposure and development are performed. , The transfer process is performed, for example, three times.

Upon completion of the first exposure and development, the paper feed roll 6 rotates in pressure contact with the upper surface of the paper at a predetermined timing to feed the uppermost paper, and the front end of the paper is caught in the gripper 8. At the same time when the paper is caught, the gripper 8 is closed, the transfer drum 2 is rotated, the paper is wound around the transfer drum 2 by the paper pressing roll 7a, and the paper is sequentially charged by the charging corotron 9 and sent to the transfer position. The developed image on the photosensitive drum 1 arrives at the timing when the paper arrives at the transfer position, and this visible developed image is transferred to the paper by the transfer corotron 3, and the first transfer of the first color is completed.

Even after this transfer is completed, the sheet remains in a state of being wound around the transfer drum 2 until the second transfer starts. Second
After the second exposure and development, the sheet and the developed image again arrive at the transfer position at a predetermined timing, and the transfer is sequentially performed. After this transfer, the paper is still wound around the transfer drum 2 and stands by for the third transfer. The third exposure, development and transfer are performed at the same time as the above, and when the transfer of the third sentence is completed, the gripper 8 is opened and the paper is separated from the surface of the transfer drum 2 by the separation claw 11 and is sequentially sent to the transport path 12.

Problems to be Solved by the Invention In such a conventional transfer transfer device, the paper pressing rollers 7a to 7a for preventing the paper from dropping from the transfer drum 2.
d and the gripper 8 for sandwiching the paper are required, the image may be disturbed by the paper pressing rollers 7a to 7d, and the transfer drum 2 is designed according to the maximum size paper to be used. Moreover, since the paper is pinched by the gripper 8, the number of paper discharged per unit time is constant and inconvenient regardless of the size of the paper.

In order to solve such inconvenience, the present applicant previously made the following proposal. That is, a transfer support material such as a transfer drum is formed of a semiconductive resin film, and a plurality of electrodes of a predetermined length are axially arranged on the semiconductive resin film at regular intervals. A transfer voltage is applied to the electrode that has moved to the transfer position, and a suction voltage has been applied to the electrode that has moved to the transfer position.
It is shown in Japanese Patent Publication No. 56-14982, and more specifically embodies the paper suction and the image transfer. ).

However, in the above-mentioned transport transfer device, there is a problem when the paper is positioned under the action of the electrostatic attraction force by the electrodes to which the attraction voltage on the upstream side and the downstream side is applied across the transfer position. However, when the transfer voltage is applied while the transfer edge is not under the action of the electrostatic attraction force of the electrodes to which the transfer voltage or the suction voltage on the downstream side of the position is applied, the end of the paper is attracted to the photosensitive drum. As a result, there is a problem that a paper jam occurs due to this, and in the case of a color copy, a color shift occurs even if the paper is peeled off with a peeling claw.

The present invention has been made to solve such a problem, and an object of the present invention is to prevent a sheet from being adsorbed on a photosensitive drum and prevent a paper jam and a color shift.

Means for Solving the Problems In order to achieve the above object, the transfer / transport device of the present invention comprises:
A semi-conductive resin film that circulates while closely adhering the paper on which the toner image of the image carrier is transferred to the outer surface of the image carrier at the transfer position, and the side of the resin film opposite to the side in contact with the image carrier. , A plurality of electrodes arranged at regular intervals, a transfer brush which slides on the electrodes at the transfer position of the paper and is applied with a DC voltage having a polarity opposite to the toner polarity, and the transfer brush at the transfer position of the paper. In a transfer transfer device equipped with a suction brush that slides on an electrode and is applied with a DC voltage, the electrostatic attraction by the electrode to which the DC voltage is applied from the suction brush when the paper tip passes through the transfer position The application of the DC voltage to the transfer brush is started when the attraction force is reached.

According to the present invention, when the leading edge of the paper passes through the transfer position and is under the action of the electrostatic attraction force by the electrode to which the DC voltage is applied from the attraction brush, the DC voltage is applied to the transfer brush. Since the electric field does not act on the front end of the paper when the front end of the paper is at the transfer position, the paper moves along the resin film due to its rigidity.

The leading edge of the paper reaches under the action of electrostatic attraction by the electrode to which a DC voltage is applied from the attraction brush on the downstream side of the transfer position,
Since the DC voltage is applied to the transfer brush in a state where the sheet is securely attracted, the transfer can be performed without the sheet being attracted to the image carrier.

Embodiment An embodiment of the transfer device according to the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and the portions substantially the same as those in FIG. 2 are designated by the same reference numerals.

The transfer drum 20 is made of a semi-conductive resin and is formed into a cylindrical shape as shown in FIG. 3, an electrode portion 22 disposed inside the resin film 21 in the film width direction, and an electrode portion 22. The transfer brushes 23a and 23b slidably disposed inside the resin film 21 at the transfer position, and the resin film 21 except for the transfer position.
And suction brushes 24a, 24b, 25a, 25b slidably arranged on the electrode portion 22 inside.

A large number of electrode portions 22 are mounted at regular intervals, and transfer brushes 23a, 23b and suction brushes 24a, 24b, 25 are attached.
A predetermined DC voltage is applied to each of a and 25b.

4 and 5 show the structure of the electrode portion 22. A large number of strip-shaped electrodes 26 are provided on the back surface of the resin film 21 at regular intervals in the longitudinal direction, and each of the electrodes 26 is made of an insulating material. It is fixed to the resin film 21 by the support layer 27, each end of the electrode 26 is exposed on the surface of the support layer 27, and the sliding electrodes 28a and 28b are formed on the exposed portions.

Further, FIG. 6 shows the power supply connection of the electrodes. The transfer power supply 31 applies a high DC voltage to the transfer brushes 23a and 23b sliding on the sliding electrodes 28a and 28b, and the voltage of the power supply 31. Is applied to the brushes 23a and 23b at a predetermined time, a brush 24a that is grounded and slides on the sliding electrode 23a, and a suction power supply 33 that applies a high DC voltage (ground side is positive) to the brush 24b, and Power supply 3
Switch 3 for applying the voltage of 3 to the brush 24b at a predetermined time
4, an adsorption power supply 35 to which a DC high voltage (ground side is positive) is applied to the brushes 25a and 25b that are grounded and slide on the sliding electrode 28a, and the voltage of the power supply 35 is applied to the brush 25b at a predetermined time. And a switch 36 for applying the voltage.

The brushes 23a, 23b, 24a, 24b, 25
Each of a and 25b is one in which a conductive fiber having a specific resistance of 10 ² Ω · cm and a length of about 5 mm is implanted in a support and is fixedly installed.

With the above configuration, when feeding the paper to the transfer unit,
When the paper feed roll 6 is driven, the switches 34 and 36 are closed at the same time, the peeling claw 11 is released, and the brushes 24a and 24b are released.
A predetermined DC voltage is applied between the brushes and between the brushes 25a and 25b. As a result, the output voltage of the power supply 35 is applied between the adjacent electrodes via the sliding electrodes 28a and 28b, and an electrostatic attraction force is generated on the surface of the resin film 21. Adsorb in order. Such an adsorption method using a semiconductive resin film is characterized in that the electrostatic attraction force rises and falls very quickly. Transfer drum 2
The resin film 21 of 0 rotates while adsorbing the paper.

The switch 32 is closed at the timing when the leading edge of the sheet arrives at the position described above, and a high DC voltage of the opposite polarity (positive in the embodiment) to the toner to which the latent image is attached is applied to each of the brushes 23a and 23b. Apply. As a result, the toner image adhering to the surface of the photosensitive drum (image carrier) 1 is transferred onto the sheet by electrostatic attraction. The transferred sheet rotates while being attracted to the surface of the resin film 21 because a voltage is applied to the attraction brushes 24a and 24b.

Here, in the case of color copying, the paper is transferred to the transfer drum 2
Rotate together with 0 to perform the next transfer, and further rotate once to perform multiple transfer for three colors. When multiple transfer is completed,
The peeling claw 11 comes into contact with the surface of the resin film 21, peels the front end of the transfer paper after the transfer from the resin film surface, and the paper is conveyed to the conveyance path 1.
Send to 2.

In the case of a single color copy, turn off the switch 36,
When one transfer is completed, the peeling claw 11 is brought into contact with the surface of the resin film 21, the paper is peeled off, the paper is sent to the transport path 12, and the paper is supplied to a fixing unit (not shown).

The operation of the embodiment of the present invention will be described in detail with reference to FIG.
As shown in FIG. 8 (A), while the leading edge of the sheet 4 is passing near the contact between the photosensitive drum 1 and the resin film 21, the changeover switch 3
When the switch 2 is turned off, the transfer brush 23 is grounded. On the side (upstream side) where the sheet 4 approaches the photosensitive drum 1, the sheet 4 is strongly attracted to the resin film 21 by the electric field created by the suction brushes 24a and 24b. Since no electric field is applied to the leading edge of the sheet 4, the sheet 4 moves along the resin film 21 due to its rigidity.

As shown in FIG. 8B, even if a high voltage is applied to the transfer brush 23 after the leading edge of the sheet 4 is within the working range of the suction electrode on the downstream side, the resin film remains near the leading edge of the sheet 4. Since the sheet 21 is strongly attracted to the sheet 21, the sheet 4 can be transferred without being attracted to the photosensitive drum 1 side.

The leading edge of the sheet 4 cannot be completely transferred,
Since the paper 4 is in contact with the photosensitive drum 1 over the entire area, some contact transfer is performed even at the leading end portion where no transfer electric field is applied, and since the gap between the electrodes is about 2 mm, the paper 4 can be peeled off.

FIG. 7 shows another embodiment of the present invention, in which the same components as in FIG. 2 are designated by the same reference numerals.

This embodiment is characterized in that the transfer support material is formed into a belt shape, and is composed of a belt 40 in which a semiconductive resin is endlessly formed, and a pair of rolls 41a and 41b on which the belt 40 is mounted. Is arranged on the horizontal plane of the belt 40,
An image carrier 42a for cyan, which develops the same original image with cyan, magenta, and yellow toners, respectively.
Image carrier 42b for magenta color, image carrier 4 for yellow color
2c and the paper fed from the paper feed roll 6 to the belt 40
A suction brush 43 that is attracted by electrostatic attraction onto the sheet, a transfer brush 44 that transfers the cyan image formed on the image carrier 42a onto the sheet conveyed by the belt 40, and a sheet onto which the cyan image has been transferred. And a transfer brush 46 for transferring the magenta image formed on the image carrier 42b onto the sheet conveyed by the belt 40, and a sheet for transferring the magenta image on the belt surface. And a transfer brush 48 for transferring the yellow image formed on the image carrier 42c onto the sheet conveyed by the belt 40. As shown in FIGS. 4 and 5, the belt 40 has electrodes 26
Is sandwiched between the resin film 21 and the support layer 27, and the sliding electrode 2
8a and 28b are exposed on the back surface of the support layer 27.

In the above configuration, the paper feed roll 5 is moved to the paper feed roll 6
When the paper is supplied by the paper, the paper is detected by a paper feed sensor (not shown), and the image is detected by the detection.
The image forming timing for 42 c is determined. At the same time, a predetermined high DC voltage is applied to each of the suction brushes 43, 45, 47.

The sheet sucked by the suction brush 43 is the image carrier 42a.
The high voltage is applied to the transfer brush 44 at the timing when the leading edge of the sheet arrives at the position described above, and the cyan image is transferred onto the sheet. At this time, the sheet advances integrally with the belt 40 without being adsorbed by the image carrier 42a, and is conveyed immediately below the image carrier 42b by the adsorbing force of the adsorbing brush 45. Similarly, magenta and yellow images are sequentially transferred to the sheet by the image carriers 42b and 42c.

Since the developed images are formed on the image carriers 42a to 42c sequentially for the sheet transport time, the images of the three colors are controlled so as to overlap each other. The sheet for which the multiple transfer has been completed in this manner is sent to a fixing device (not shown) to be fixed.

Effects of the Invention According to the present invention as described above, it is possible to reliably prevent the sheet from being adsorbed to the photosensitive drum, and to prevent a paper jam or a color shift in the case of color copying.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a transfer / transfer device of the present invention, FIG. 2 is a schematic configuration diagram showing a conventional transfer / transfer device, and FIG. 3 is a perspective view showing a resin film in the embodiment of the present invention. FIG. 4 is a cross-sectional view showing the electrode and its periphery in the embodiment of the present invention, FIG. 5 is a plan view showing the electrode and its periphery in the embodiment of the present invention, and FIG. 6 shows the connection between the electrode and the power supply. FIG. 7 is a schematic diagram showing another embodiment of the present invention, and FIGS. 8A and 8B are schematic configuration diagrams showing the operation of the embodiment of the present invention. 1 ... Photosensitive drum (image carrier), 20 ... Transfer drum, 21 ... Resin film, 22 ... Electrode part, 23a, 23b ... Transfer brush, 24a, 24b, 25a, 25b ... Adsorption brush , 26 ... Electrodes, 27 ... Support layer, 28a, 28b ... Sliding electrodes.

Claims (1)

[Scope of utility model registration request] 1. A semi-conductive resin film which circulates while a sheet on which a toner image of an image carrier is transferred is closely attached to the outer surface of the image carrier at a transfer position, and a semiconductive film which is in contact with the image carrier of the resin film. A plurality of electrodes arranged at regular intervals on the side opposite to the side, a transfer brush that slides on the electrodes at the transfer position of the paper and is applied with a DC voltage having a polarity opposite to the toner polarity, and In a transport transfer device provided with a suction brush that slides on the electrodes at a transport position and a DC voltage is applied, the leading edge of the paper passes the transfer position, and a DC voltage is applied from the suction brush. A transfer transfer device, wherein the application of the DC voltage to the transfer brush is started when the electrostatic attraction force by the electrodes is reached.