JPH0451451B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to an electronic copying machine, in which a transfer paper fed from a paper feeding device is conveyed between a photoreceptor and a transfer device, and the transfer paper on which a toner image has been transferred. The present invention relates to a transfer paper transport device that transports paper to a fixing device.

BACKGROUND ART As a transfer paper conveyance device, one is known in which a loop-shaped conveyance belt conveys the transfer paper, and a belt position correction means corrects the deviation in the position of the conveyance belt. However, in this transfer paper conveyance device, when the belt position correction means corrects the deviation in the position of the conveyance belt while the toner image on the photoreceptor is being transferred to the transfer paper, the correction direction may be switched. This has the disadvantage that it adversely affects the transfer of the toner image onto the transfer paper.

Purpose An object of the present invention is to provide a transfer paper conveyance device that does not adversely affect the transfer of a toner image onto a transfer paper when the belt position correction means corrects the deviation in the position of the conveyance belt.

Configuration The present invention will be described in detail based on the embodiments illustrated below.

In FIG. 1, numerals 1 and 2 indicate photoreceptors, respectively. Around these photoreceptors 1 and 2,
In addition to the paper feeding device A, the transfer paper conveyance device B, the transfer device C, and the fixing device D, a charging device, an exposure device, a developing device, a cleaning device, a static eliminating device, etc., which are not shown, are arranged. The toners for developing the electrostatic latent images on the photoreceptors 1 and 2 are of different colors.

The paper feeding device A includes a cassette 4 which is arranged at a predetermined distance from the photoreceptor 1 and accommodates a plurality of transfer sheets 3, and a cassette 4 which is rotatably arranged inside this cassette 4 and which holds a plurality of transfer sheets 3. 3, a spring 6 disposed between the rotating bottom plate 5 and the bottom plate 4a of the cassette 4 and pressing the rotating bottom plate 5 upward, and a spring 6 disposed between the rotating bottom plate 5 and the bottom plate 4a of the cassette 4; A paper feed roller 7 disposed above the front part of the paper feed roller 7 , a friction pad 8 elastically pressed against the lower part of the paper feed roller 7 , and a friction pad 8 between the paper feed roller 7 and the photoreceptor 1 . It consists of a pair of registration rollers 9 and a guide plate 10 placed between the paper feed roller 7 and the registration rollers 9.

The transfer paper 3 in the cassette 4 is pressed against a paper feed roller 7 by the pressing force of a spring 6.
When this paper feed roller 7 is rotated in the direction of the arrow during paper feeding, the transfer paper 3 is fed in the direction of the registration roller 9 due to rotational force and frictional force. The friction pad 8 prevents a plurality of transfer sheets 3 from being fed simultaneously by the sheet feed roller 7. The registration roller 9 temporarily waits for the transfer paper 3 sent by the paper feed roller 7, and then transfers the transfer paper 3 to the photoreceptor 1.
Transfer paper 3 is transferred to photoreceptors 1 and 2 in synchronization with toner image 2.
Send in the direction of.

The transfer paper conveyance device B includes a loop-shaped conveyance belt 11 made of a dielectric material, a driving roller 12 and a driven roller 13 for moving the conveyance belt 11 in the direction of arrow a, and a deviation in the position of the conveyance belt 11. Deviation correction roller 1 for correcting
4, a roller position adjustment means 15 that adjusts the position of the bias correction roller 14, and a charging device 16 that charges the transfer paper 3 sent from the registration roller 9 and brings it into close contact with the conveyor belt 11 by electrostatic force. a paper separation member 18 for separating the transferred transfer paper 3 from the conveyance belt 11 of a static eliminator 17 for removing static from the transferred transfer paper 3 in order to separate the transfer paper 3 from the conveyance belt 11; A cleaning member 19 that cleans the conveyor belt 11
, a static eliminator 20 that neutralizes the portion of the conveyor belt 11 that has been charged by the transfer device C, and a detection target piece 21 fixed to the conveyor belt 11 passes through it during a time when no toner image is transferred to the transfer paper 3. a sensor 22 that detects the
The sensor includes a deviation sensor 24 that detects deviation from the position of the conveyor belt 11 by detecting a detected piece 23 fixed to the position.

The transfer paper 3 sent from the registration roller 9 is charged by a charging device 16, brought into close contact with the conveyor belt 11 by electrostatic force, and moved in the direction of arrow a. Next, when the transfer paper 3 is moved in the direction of arrow a by the conveyor belt 11 and passes between the photoreceptors 1 and 2 and the transfer device C, the transfer device C is moved by the conveyor belt 11.
a photoreceptor 1 that is charged with electrostatic force;
2 toner image is transferred onto transfer paper 3. Next, the transfer paper 3 is electricity-eliminated by the electricity-eliminating device 17, separated from the conveyor belt 11 by the paper separation member 18, and sent to the fixing device D.

As shown in FIG. 2, the roller position adjustment means 15 includes a latch solenoid 15a, a drive circuit 15b that supplies current to drive the latch solenoid 15a, and one end that engages with the shaft of the deviation correction roller 14. It consists of a lever 15d whose intermediate portion is rotatably supported by 15c, and a connecting plate 15f that connects the other end of this lever 15d and the actuation rod 15e of the latch solenoid 15a. The above drive circuit 1
5b is a solenoid 15 that latches current in different directions.
When a current in a different direction is supplied to the latch solenoid 15a, the actuating rod 15e is moved in the direction of arrow b or in the opposite direction. The latch solenoid 15a keeps the actuating rod 15e stationary at a predetermined position when no current is supplied in the opposite direction to the previously supplied current.

The bias correction roller 14 and the roller position adjustment means 15 constitute belt position correction means.

The bias correction roller 14 and the roller position adjustment means 15 constitute belt position correction means. When the bias correction roller 14 is disposed at the position shown in FIG.
When the position of the bias correction roller 14 is moved in the direction, the correction direction of the conveyor belt 11 is switched to the direction opposite to the direction of the arrow c.

The sensor 22 includes a light emitting element, such as a light emitting diode 22a that emits infrared light, and a light receiving element, such as a phototransistor 22b. The bias sensor 24 also includes a light emitting element, such as a light emitting diode 24a that emits infrared light, and a light receiving element, such as a phototransistor 24b.
Consists of etc. The detection target pieces 21 and 23 are made of aluminum foil.

The positional relationship between the detected piece 21 and the sensor 22 is such that the toner image is not transferred to the transfer paper 3, that is, after the toner image has been transferred to the preceding transfer paper 3, the toner image is transferred to the following transfer paper 3. The detected piece 21 passes through a position that receives infrared rays from the light emitting diode 22a of the sensor 22 within the time until image transfer is started. When the detection target piece 21 is irradiated with infrared rays from the light emitting diode 22a of the sensor 22, the infrared rays reflected from the infrared rays are incident on the photodiode 22b. The positional relationship between the detected piece 23 and the bias sensor 24 is such that only when the conveyor belt 11 is biased to one side, the position where the detected piece 23 receives the infrared rays from the light emitting diode 22a of the sensor 22 is
The detected piece 23 passes through a position that receives infrared rays from the light emitting diode 24a of the bias sensor 24 in synchronization with the passing of the light emitting diode 24a. When the detection target piece 23 is irradiated with infrared rays from the light emitting diode 24a of the bias sensor 24, the infrared rays reflected from the infrared rays are incident on the photodiode 24b. Note that when the conveyor belt 11 is biased to the other side, the detection target piece 23 does not pass through the position where the infrared rays from the light emitting diode 24a of the bias sensor 24 are received.

Next, the sensor 22 and the bias sensor 24
A means for controlling the operation of the belt position correcting means consisting of the deviation correcting roller 14 and the roller position adjusting means 15 based on the output signal will be explained with reference to FIG.

In FIG. 3, reference numeral 25 indicates a terminal to which a predetermined positive voltage is applied by the power supply circuit.
Between this terminal 25 and the ground, a series connection body of a resistor 22c and a light emitting diode 22a, a connection body of a resistor 22d and a phototransistor 22b, and a resistor 2
A series connection body consisting of resistor 2e and resistor 22f is connected in parallel. The above resistor 22d and phototransistor 2
The connection point d of the resistor 2b and the connection point e of the resistor 22e and the resistor 22f are respectively connected to the input terminal of the comparison circuit 22g. . The light emitting diode 22a
The resistor 22d and the phototransistor 2 are connected only when the phototransistor 22b is electrically connected to the phototransistor 22b by being irradiated with infrared rays from the detected piece 21 and reflected from the phototransistor 22b.
The voltage at the connection point d of 2b is the voltage of the resistor 22e and the resistor 22f.
The comparison circuit 22g outputs a higher voltage than the voltage at the connection point e. The light emitting diode 22
a, phototransistor 22b, resistor 22c, 2
2d, 22e, 22f and the comparison circuit 22g constitute the sensor 22.

Further, a resistor 2 is connected between the terminal 25 and the ground.
A series connection body of 4c and the light emitting diode 24a, a series connection body of the resistor 24d and the phototransistor 24b, and a series connection body of the resistor 24e and the resistor 24f are connected in parallel. A connection point f between the resistor 24d and the phototransistor 24b and a connection point g between the resistor 24f and the resistor 24e are respectively connected to input terminals of a comparison circuit 24g. The voltage at the connection point f between the resistor 24d and the phototransistor 24b increases only when the phototransistor 24b becomes conductive by irradiating the detection target piece 23 with infrared rays from the light emitting diode 24a, which is reflected from the infrared rays and incident on the phototransistor 24b. The voltage becomes lower than the voltage at the connection point g between the resistor 24e and the resistor 24f, and the comparator circuit 2
4g outputs high voltage. The light emitting diode 24a, the phototransistor 24b, and the resistor 24
c, 24d, 24e, 24f and comparison circuit 24
g constitutes the bias sensor 24 mentioned above.

The output terminals of the comparison circuits 22g and 24g are connected to the input terminals of an AND circuit 26, and the output terminal of the AND circuit 26 is connected to the drive circuit 15b of the roller position adjustment means 15. The output terminal of the comparison circuit 22g is connected to the input terminal of an AND circuit 27, and the output terminal of the AND circuit 26 is connected to the input terminal of the AND circuit 27 via an inverter 28. The output terminal of this AND circuit 27 is connected to the drive circuit 15b.

When the output voltage from the comparison circuit 22g is high and the output voltage from the comparison circuit 24g is high, only the AND circuit 26 provides a high output voltage to the drive circuit 15b. When the output voltage from the comparison circuit 22g is high and the output voltage from the comparison circuit 24g is low, only the AND circuit 27 provides a high output voltage to the drive circuit 15b. The drive circuit 15b supplies current to the latch solenoid 15a when the output voltage of either the AND circuit 26 or 27 is high;
The direction of the current supplied to 5a differs depending on whether the output voltage of the AND circuit 26 is high or the output voltage of the AND circuit 27 is high.

Therefore, the sensor 22 detects the detected piece 21.
, and the bias sensor 24 detects the detected piece 2
The direction of correction of the deviation of the conveyor belt 11 when detecting
, and the bias sensor 24 detects the detected piece 2
The correction direction of the deviation of the conveyor belt 11 is opposite to the direction of correction of the deviation of the conveyor belt 11 in the case where the transfer belt 3 is not detected, and the direction of correction of the deviation of the conveyor belt 11 is switched at a time when no toner image is transferred to the transfer paper 3.

In addition, when the conveyance belt 11 has a connecting part, the detected piece 2 fixed to the conveyance belt 11
By adjusting the relative positional relationship between the connecting portion of the conveying belt 11 and the conveying belt 11, the transfer paper 3 can be prevented from being placed on the connecting portion of the conveying belt 11. If the transfer paper 3 is not placed on the connecting portion of the conveyor belt 11, the toner image will not be transferred to the transfer paper 3 at the connecting portion of the conveyor belt 11. It is possible to prevent an adverse effect on image transfer.

Effects The transfer paper conveyance device of the present invention has the following effects when the belt position correction means corrects the deviation in the position of the conveyance belt.
Since the correction direction of the conveyor belt position is switched during the time when the toner image is not transferred to the transfer paper, the transfer of the toner image to the transfer paper is not adversely affected.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a part of an electronic copying machine having a transfer paper conveyance device of the present invention, FIG. 2 is a partially cutaway perspective view showing the transfer paper conveyance device of the present invention, and FIG. FIG. 3 is an electric circuit diagram showing a means for controlling the operation of a belt position correcting means of the transfer paper conveying device. 11... Conveyor belt, 14... Deviation correction roller, 15... Roller position adjustment means, 21, 23
...Detected piece, 22... Sensor, 24... Bias sensor.

Claims (1)

[Claims] 1 A transfer process in which a loop-shaped conveyor belt conveys the transfer paper sent from the paper feeder between the photoconductor and the transfer device, and the transfer paper with the toner image on the photoconductor transferred to the fixing device. In the paper conveyance device,
The transfer paper conveying device detects that the position of the conveyor belt is deviated from the proper position during the time when the toner image is not transferred to the transfer paper, and switches the direction of correction of the deviation of the position of the conveyor belt. .