JPH0627826A - High voltage controller for separation - Google Patents

Abstract

PURPOSE:To perform discharge within a real use range by simple circuit constitution by constituting a separation electrode of a discharge wire and a grid wire, and connecting an AC high voltage power source to the discharge wire and a DC high voltage power source for controlling grid potential to the grid wire. CONSTITUTION:The separation electrode 12 is constituted of the discharge wire 120 and the grid wire 121, and the AC high voltage power source 520 without the correction of DC component for performing corona discharge and the DC high voltage power source 521 for controlling the grid potential are connected to the discharge wire 120 and the grid wire 121, respectively. A high voltage power source for separation 52 is constituted of the AC high voltage power source 520 and the DC high voltage power source 521 which are respectively independent. A high voltage power source for electrostatic charge 50, a high voltage power source for transfer 51, and a high voltage power source for separation 52 are driven according to a command from a control part 53. An electrostatic charge current value command and a transfer current value command are outputted to the power source 50 and the power source 51, respectively. Then, an AC component separation current command and a DC component separation current command are outputted to the AC high voltage power source 520 of the power source 52 and the DC high voltage power source 521, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separating high-voltage controller used in an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, an image exposed on a photoconductor is developed by an optical system to form a toner image, and the toner image on the photoconductor is transferred to a transfer electrode and a separation electrode. In some cases, the toner image is transferred onto the transfer paper, and then heated and pressed to fix the toner image on the transfer paper. As a separating electrode for separating the transfer paper from the photoconductor, for example, an AC high voltage is applied when the drum of the photoconductor has a large curvature, and a DC high voltage is applied when the drum of the photoconductor has a small curvature.

[0003]

By the way, in the case of applying an AC high voltage to the separation electrode for separating the transfer paper from the photosensitive member, when an AC voltage as shown by the broken line in FIG. 5 is applied, it is shown by the solid line. Such a discharge current can be obtained. Even if the applied voltage V is the same voltage on the plus side and the minus side,
Since the negative side of the discharge current I is easily discharged, the negative side tends to be larger than the positive side. This discharge current I
Is the AC component current I (ac) and the DC component current I (d
This is represented by the sum of c), and this high voltage output characteristic is shown in FIG.
In FIG. 6, since the discharge current I tends to be larger on the minus side than on the plus side, the high-voltage output characteristic due to the discharge current I deviates from the actual use range A to the minus side, and the actual use range A cannot be supported. .

Therefore, for example, there is a fixed correction as shown in FIG. That is, the AC output transformer 100 is used, the power source E1 and the current control circuit 101 are connected to the primary side, and the fixed correction circuit 102 and the current detection circuit 1 are connected to the secondary side.
03 is connected, and the current detection circuit 103 detects the secondary side current detection and sends it to the current control circuit 101. The current control circuit 101 controls the primary side, controls the secondary side AC voltage, and corrects this AC voltage by the fixed correction circuit 102. The fixed correction circuit 102 can be configured by, for example, a parallel circuit of a diode D1 and a resistor R1 as shown in FIG. 8 or a constant voltage diode ZD as shown in FIG. By correcting the applied voltage in this way, FIG.
It is possible to obtain a high voltage output characteristic as shown in. By the way, the AC component current I (ac) can correspond to the actual use range A, but the DC component current I (dc) cannot be varied, which is not sufficient.

Further, for example, there is one that variably corrects as shown in FIG. That is, the AC output transformer 110,
Using the DC output transformer 111, the AC output transformer 11
The power source E2 and the AC current control circuit 112 are connected to the primary side of 0, the AC component separation capacitor C1 and the AC current detection circuit 113 are connected to the secondary side, and the AC current detection circuit 113 detects the secondary side current. Detect and AC current control circuit 112
Send to. This AC current control circuit 112 controls the primary side and controls the AC voltage on the secondary side. In addition, the power source E3 and the DC current control circuit 1 are provided on the primary side of the DC output transformer 111.
14 is connected, and the DC correction direction switching diode D2 and the DC current detection circuit 115 are connected to the secondary side. The DC current detection circuit 115 detects the secondary side current and sends it to the DC current control circuit 114. This DC current control circuit 114
Controls the primary side and controls the DC voltage on the secondary side.

By correcting the applied voltage in this manner, a high voltage output characteristic as shown in FIG. 12 can be obtained. By the way, the AC component current I (ac) can correspond to the actual use range A, and the DC component current I (dc) can be changed, but since it is corrected on the negative side by the arrangement of the DC correction direction switching diode D2, This is not sufficient because it cannot cover the entire actual use range A.

Further, for example, there is one that variably corrects as shown in FIG. That is, the AC output transformer 110,
The configuration is similar to that of FIG. 11 using the DC output transformer 111, but the DC correction direction switching diode D3 is arranged in the opposite direction, and the positive side is corrected to be variable, so that FIG.
It is possible to obtain high voltage output characteristics as shown in FIG. By the way, the AC component current I (ac) can correspond to the actual use range A, and the DC component current I (dc) can be changed, but since it is corrected on the plus side, it corresponds to the entire actual use range A. Not enough because you can't.

As described above, any correction of the applied voltage is insufficient because neither the AC component current I (ac) nor the DC component current (dc) of the discharge current can correspond to the actual use range A. The circuit configuration for correction is complicated.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a separation high-voltage control device capable of discharging in an actual use range with a simple circuit configuration.

[0010]

In order to solve the above-mentioned problems, the present invention comprises a separating electrode for separating the transfer paper from the photosensitive member, and a high voltage power source for applying a high voltage to the separating electrode. In the separation high-voltage control device, the separation electrode is constituted by a discharge wire and a grit wire, an AC high-voltage power supply is connected to the discharge wire, and a DC high-voltage power supply for controlling the grid potential is connected to the grit wire. Is characterized by.

[0011]

According to the present invention, the separation electrode is composed of the discharge wire and the grit wire, the discharge wire is connected to the AC high voltage power source, and the grit wire is connected to the DC high voltage power source for controlling the grid potential. By separating the application and the application of the DC high-voltage power supply, independent control becomes possible and discharge in the actual use range can be performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the separation high pressure control device of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus including a separation high-voltage control device.

A photoconductor 2 is provided in a main body 1 of the image forming apparatus so as to be rotatable in an arrow direction, and a document glass 3 is attached to an upper portion of the main body 1. An optical system including a light source 4, mirrors 5, 6, 7 and a lens 8 is arranged below the original glass 3, and an image of an original set on the original glass 3 is sensed by this optical system as a photoconductor. 2 is exposed. The light source 4 and the mirror 5 of this optical system move back and forth in conjunction with each other during exposure, and the lens 8 and the mirror 6 move in conjunction with each other during zooming.

Around the photosensitive member 2, a charging electrode 9, a developing unit 10, a transfer electrode 11, a separating electrode 12 and a cleaning unit 13 are arranged, and an image exposed on the photosensitive member 2 by an optical system is displayed. The image is developed, transferred to the transfer paper 14 and recorded. The transfer paper 14 is accommodated in a plurality of paper feed stages, that is, a first paper feed stage 15, a second paper feed stage 16, a third paper feed stage 17, and a fourth paper feed stage 18 from the top. Each paper feed stage 15-
On the upper surface of the transfer paper 14 of 18, the paper feed rollers 19
22 to 22 are arranged, and the transfer paper 14 is intermittently sent out by rotation of a paper feed drive motor (not shown) connected to each other. Each of the paper feed rollers 19 to 22 has a double feed prevention roller 23 to
26 is provided side by side, and the transfer paper 14 is sent to the next process one by one.

The transfer paper 14 delivered from each stage is inserted into each of the transport rollers 27-30. These transport rollers 27 to 30 are arranged in series and send the transfer paper 14 to the next transport roller. The transfer paper 14 delivered from the uppermost transport roller 27 is inserted into the registration roller 31 arranged immediately before the transfer processing section. The registration roller 31 abuts and stops the transfer paper 14, aligns the front end of the transfer paper 14 in a direction perpendicular to the traveling direction, and stops the transfer of the transfer paper 14 at the rear end by the registration sensor 32 to align the transfer paper 14. The transferred transfer paper 14 is sent out to the transfer area of the transfer processing unit after a lapse of a certain time. The transfer paper 14 includes a photoconductor 2, a transfer electrode 11, and a separation electrode 12 which constitute a transfer processing section.
Then, the toner image is carried on the carrier unit 34 through the separation claw 33 and is sent to the fixing unit 35. A winding detection sensor 36 is provided at the subsequent stage of the separation claw 33, and the winding detection sensor 36 monitors the winding of the transfer paper 14. The transfer paper 14 is heated and pressed in the fixing unit 35 to fix the toner image on the transfer paper 14, and the toner image is sent to a discharge tray (not shown).

FIG. 2 is a block diagram of the separation high-voltage controller,
FIG. 3 is a configuration diagram of the high voltage power supply for separation, and FIG. 4 is a diagram showing high voltage output characteristics. A charging high voltage power supply 50 is connected to the charging electrode 9 arranged above the photoconductor 2, and a transfer high voltage power supply 51 is connected to the transfer electrode 11 arranged below the photoconductor 2.
Are connected.

Further, the separation electrode 12 arranged in the vicinity of the transfer electrode 11 is composed of a discharge wire 120 and a grit wire 121, and the discharge wire 120 is subjected to a corona discharge and an alternating current having no direct current component correction. High-voltage power supply 5
20 is connected to the grid wire 121, a DC high-voltage power supply 521 for controlling the grid potential is connected, and the separation high-voltage power supply 52 is an independent AC high-voltage power supply 520.
It is composed of a DC high voltage power supply 521.

Each of the charging high-voltage power supply 50, the transfer high-voltage power supply 51, and the separation high-voltage power supply 52 is driven by a command from the controller 53, and the charging high-voltage power supply 50 sends a charging current value command to the transfer high-voltage power supply. A transfer current value command is sent to the power source 51.
An AC component separation current command is output to the AC high voltage power supply 520 of the separation high voltage power supply 52, and a DC component separation current command is output to the DC high voltage power supply 521.

AC high-voltage power source 5 of this separating high-voltage power source 52
20 and the DC high-voltage power supply 521 are configured as shown in FIG. The AC high voltage power supply 520 is the AC output transformer 1
An AC current control circuit 123 is connected to the primary side of 22 and an AC current detection circuit 124 is connected to the secondary side thereof. The AC current detection circuit 124 detects the secondary side current and sends it to the AC current control circuit 123. The AC current control circuit 123 controls the primary side and controls the AC applied voltage on the secondary side.

In the DC high voltage power supply 521, the DC current control circuit 126 is connected to the primary side of the DC output transformer 125, and the DC correction direction switching diode D and the DC current detection circuit 127 are connected to the secondary side. The DC current detection circuit 127 detects the secondary side current to detect the DC current control circuit 126.
The direct current detection circuit 127 controls the primary side to control the DC applied voltage on the secondary side.

As described above, the application of the AC high-voltage power supply 520 and the application of the DC high-voltage power supply 521 are independently performed,
By controlling each independently, the high voltage output characteristic as shown in FIG. 4 can be obtained. Since both the alternating current component current I (ac) and the direct current component current I (dc) of this discharge current can be varied, it can correspond to the actual use range A, and the circuit configuration for correction is simple.

[0022]

As described above, according to the present invention, the separation electrode is composed of the discharge wire and the grit wire,
Connect the AC high-voltage power supply to the discharge wire, and connect the DC high-voltage power supply that controls the grid potential to the grit wire.
By separating the AC high-voltage power supply and the DC high-voltage power supply, independent control is possible, discharge in the actual use range can be performed, and the correction circuit configuration is simple.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus including a separation high-voltage control device.

FIG. 2 is a block diagram of a separation high-voltage control device.

FIG. 3 is a configuration diagram of a high voltage power supply for separation.

FIG. 4 is a diagram showing high voltage output characteristics.

FIG. 5 is a diagram showing the relationship between discharge current and applied voltage.

FIG. 6 is a diagram showing a relationship between a use range of a separation current and a discharge current characteristic.

FIG. 7 is a circuit diagram of a separating high-voltage power supply for fixed correction of applied voltage.

FIG. 8 is a fixed correction circuit diagram of an applied voltage.

FIG. 9 is a fixed correction circuit diagram of an applied voltage.

10 is a diagram showing the relationship between the use range of the separation current and the discharge current characteristic corrected by the circuit of the high voltage power supply for separation of FIG. 7.

FIG. 11 is a circuit diagram of a separating high-voltage power supply for variable correction of an applied voltage.

12 is a diagram showing the relationship between the range of use of the separation current and the discharge current characteristic corrected by the circuit of the high voltage power supply for separation of FIG.

FIG. 13 is a circuit diagram of a separation high-voltage power supply for variable correction of applied voltage.

14 is a diagram showing the relationship between the use range of the separation current and the discharge current characteristic corrected by the circuit of the high voltage power supply for separation of FIG.

[Explanation of symbols]

 2 Photoreceptor 12 Separation Electrode 14 Transfer Paper 52 Separation High Voltage Power Supply 120 Discharge Wire 121 Grit Wire 520 AC High Voltage Power Supply 521 DC High Voltage Power Supply

Claims (1)

[Claims] 1. A separation high voltage control device comprising a separation electrode for separating a transfer paper from a photoconductor and a high voltage power source for applying a high voltage to the separation electrode, wherein the separation electrode is a discharge wire and a grit. A high voltage control device for separation, comprising a wire, an AC high voltage power source is connected to the discharge wire, and a DC high voltage power source for controlling a grid potential is connected to the grit wire.