KR101022475B1 - High voltage power supply in color image forming apparatus - Google Patents

Abstract

A high voltage power supply of a color image forming apparatus is disclosed. The color image forming apparatus is a power supply of a non-contact single pass color image forming apparatus using a superimposed power source of direct current and alternating current, and direct current and alternating current to a plurality of developing rollers consisting of C, M, Y, and K. Developing a high voltage power supply; A charging high voltage power supply unit supplying charging power to a plurality of charging rollers including C, M, Y, and K; A transfer high voltage power supply unit supplying a transfer power to a plurality of transfer rollers each including C, M, Y, and K; And a control unit for controlling on / off timing of the power supply units, wherein the developing high voltage power supply branch supplies power from the overlapping power supply of the direct current and alternating current to the plurality of developing rollers, and the control unit prints. When is started, before the application of the overlapping power of the direct current and alternating current to the plurality of developing rollers is characterized in that the charging power is applied simultaneously or first to each charging roller. This can reduce the cost and size of the color imager.

Description

High voltage power supply in color image forming apparatus

1 is a diagram illustrating a conventional single pass non-contact developing electrophotographic developing apparatus having a separate power supply for each device.

FIG. 2 illustrates a single pass non-contact color image forming apparatus for supplying a common voltage to Y, M, C, and K developing rollers according to an embodiment of the present invention.

3 is a diagram illustrating a single pass non-contact color image forming apparatus supplying a common voltage to Y, M, C, and K transfer rollers according to an embodiment of the present invention.

4 is a diagram illustrating a power supply device of the single-pass non-contact color image forming apparatus of FIG. 2 according to one embodiment of the present invention.

FIG. 5 is a diagram illustrating a power supply device of the single-pass non-contact color image forming apparatus of FIG. 3 according to one embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100C, 100M, 100Y, 100K: Photosensitive Drum (OPC)

110C, 110M, 110Y, 110K: Developing Roller

120C, 120M, 120Y, 120K: Daejeon Roller                 

130C, 130M, 130Y, 130K: Transfer Roller

110C: Developing high voltage power (AC 110A and DC power 110B)

130A: high voltage power supply

130K2, 130C2, 130M2, 130Y2: Zener Diodes

210: developing high voltage power supply

220: high voltage power supply unit

230: high-voltage power supply unit

400, 500: High Voltage Power Supply (HVPS)

410, 510: high voltage power supply control unit (HVPS control unit)

C: cyan, M: magenta, Y: yellow, K: black

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply of a color image forming apparatus, and more particularly, to a power supply of a non-contact developing single pass color image forming apparatus using a DC and AC superimposed power source. The present invention relates to a power supply of a single-pass color image forming apparatus of a non-contact developing method for reducing the cost and size of a color image apparatus by providing one common power source (superposition power supply of direct current and alternating current) to each developing roller.

In general, an electrophotographic image forming apparatus exposes a photosensitive medium in accordance with image information obtained from an original or a predetermined source to form an electrostatic latent image which is not visible on the photosensitive medium. Next, a developer (toner) is attached to a portion where the electrostatic latent image is formed to visualize the electrostatic latent image. Then, the desired image is printed by transferring and fixing the image visualized by the development onto a medium such as paper.

On the other hand, the single pass type color image forming apparatus is configured such that a plurality of color image forming units for forming a color image are arranged in the traveling direction of the transfer belt in order to speed up image formation, and a tandem method. Also called a color image forming apparatus. The plurality of color imaging units include a transmission belt in which a color imaging unit that develops an image in each color of cyan, magenta, yellow, and black blocks. It is generally arranged in the direction of travel. The non-contact developing method is a method in which the developing roller and the photosensitive member are spaced apart at predetermined intervals and developed.

1 is a diagram illustrating a conventional single pass non-contact developing electrophotographic developing apparatus having a separate power supply for each device.

Referring to FIG. 1, each color image forming unit has electrostatic latent images formed on the photoconductors 100C, 100M, 100Y, and 100K, and the photoconductors 100C, 100M, 100Y, and 100K for transferring images to the transfer belt 102. Referring to FIG. Developing rollers 110C, 110M, 110Y, and 110K for developing the toner or ink, and charging rollers 120C, 120M, and 120Y for charging the surfaces of the photoconductors 100C, 100M, 100Y, and 100K. , 120K), and transfer rollers 130C, 130M, and 130Y 130K facing the photosensitive members 100C, 100M, 100Y, and 100K and the transfer belt 102 therebetween.                         

Meanwhile, predetermined high voltage powers are supplied to the rollers, and the developing high voltage powers 110C1 + 110C2 and 110M1 + 110M2 are supplied to the developing rollers 110C, 110M, 110Y, and 110K as shown in FIG. 1. , 110Y1 + 110Y2, 110K1 + 110K2), the charging high voltage power supplies 120C1, 120M1, 120Y1, 120K1 supplied to the charging rollers 120C, 120M, 120Y, 120K, and transfer rollers 130C, 130M, 130Y 130K. ) Are the transfer high voltage power supplies 130C1, 130M1, 130Y1, and 130K1.

In particular, the non-contact developing method as shown in Figure 1, unlike the contact developing method to implement a non-contact phenomenon, as shown, it is characterized by applying an AC power superimposed on the direct current as a developing high-voltage power supply.

However, according to the above prior arts, there are the following problems.

That is, in the contact developing method in which the developing roller contacts the photosensitive member and develops, the driving load is large. Therefore, in recent years, it has become common to adopt a noncontact phenomenon. In particular, in the case of a multi-pass color printer rather than a single pass, many color printers using a non-contact phenomenon have been introduced to the market.

However, in case of single pass color printer adopting non-contact developing method, it is necessary to apply overlapping power of direct current and alternating current to each of C, M, T, and K developing rollers. Is particularly large, and the cost increases.

The present invention has been created to solve the above problems, by supplying a single DC and AC overlapping power to the C, M, Y, K developing roller in common, while reducing the cost, the size of the high-voltage power supply The purpose is to reduce the

Another object of the present invention is to provide a control method for realizing a predetermined image without generating a side effect in an image in the case of supplying one DC and AC overlapping power to each developing roller in common. The purpose is to provide.

In order to achieve the above object, the power supply apparatus according to the present invention is a power supply apparatus of a non-contact single pass color image forming apparatus using a superimposed power source of DC and AC, comprising a plurality of C, M, Y, and K. Developing high voltage power supply for supplying superimposed power of direct current and alternating current to the developing rollers of the; A charging high voltage power supply unit supplying charging power to a plurality of charging rollers including C, M, Y, and K; A transfer high voltage power supply unit supplying a transfer power to a plurality of transfer rollers each including C, M, Y, and K; And a control unit for controlling on / off timing of the power supply units, wherein the developing high voltage power supply unit branches from one overlapping power supply of DC and AC to supply power to the plurality of developing rollers.

Preferably, when the printing is started, the control unit simultaneously or firstly applies the charging power to each charging roller before applying the overlapping power of the direct current and the alternating current to the plurality of developing rollers.

Preferably, the transfer high voltage power supply unit supplies transfer power to a plurality of transfer rollers consisting of the C, M, Y, and K branches from one charging power source, and the transfer voltage input to each of the transfer rollers is a constant voltage. The devices are limited to different voltages by the devices, and the constant voltage devices are zener diodes.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the power supply of the non-contact developing single-pass color image forming apparatus according to the present invention. In adding reference numerals to the components of the drawings, it should be noted that the same components are denoted by the same reference numerals as much as possible even if they are shown in different drawings. In addition, in the following description, many specific details are shown, such as components of a specific circuit, which are provided to help a more general understanding of the present invention, and the present invention may be practiced without these specific details. It is self-evident to those of ordinary knowledge in Esau. In describing the present invention, when it is determined that detailed descriptions of related known functions or configurations may obscure the gist of the present invention, the detailed description thereof will be omitted.

FIG. 2 is a diagram illustrating a single pass non-contact color image forming apparatus 200 for supplying one common voltage to Y, M, C, and K developing rollers according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a power supply of the single-pass non-contact color image forming apparatus of FIG. 2 according to one embodiment of the present invention.

Referring to FIGS. 2 and 4 with respect to the power supply device, the power supply device includes a high voltage power supply unit (HVPS) including a developing high voltage power supply unit 210, a charging high voltage power supply unit 220, and a transfer high voltage power supply unit 230. Supply 400 and the control unit 410 is made.

As shown, the transfer high pressure power supply (120C1, 120M1, 120Y1, 120K1), and the transfer roller 130C, 130M, 130Y 130K to the charging rollers (120C, 120M, 120Y, 120K) as in the prior art Power sources 130C1, 130M1, 130Y1, and 130K1 are applied as separate independent power sources.

However, unlike the related art, the developing rollers 110C, 110M, 110Y, and 110K have one overlapping power source 110C including the AC power source 110A and the AC power source 110B branched to each of the developing rollers 110C, 110M, and 110K. It can be seen that it is configured to be supplied to (110Y, 110K).

As an embodiment having the above configuration, when printing is started, the HVPS control unit 410 before applying the overlapping power source 110C of the direct current and alternating current to the plurality of developing rollers 110C, 110M, 110Y, and 110K. It is possible to control so that charging power is applied to each charging roller simultaneously or first.

In such a case, the HVPS control unit 410 may control the development by controlling the timing of exposure (in the drawings, the exposure unit is not shown). This is because development cannot occur unless the photoconductor is exposed.

On the other hand, Figure 3 is a view showing a single-pass non-contact color image forming apparatus 300 for supplying a common voltage to the Y, M, C, K transfer rollers according to an embodiment of the present invention, FIG. 5 is a diagram illustrating a power supply device of the single-pass non-contact color image forming apparatus of FIG. 3 according to one embodiment of the present invention.

Referring to FIGS. 3 and 5 in relation to the power supply device, the power supply device includes a high voltage power supply unit HVPS including a developing high voltage power supply unit 310, a charge high voltage power supply unit 320, and a transfer high voltage power supply unit 330. Power supply) 500 and the HVPS control unit 510.

As shown, the charging high voltage power supply (120C1, 120M1, 120Y1, 120K1) is applied to the charging rollers (120C, 120M, 120Y, 120K), AC power to the developing rollers (110C, 110M, 110Y, 110K). One overlapping power source 110C including the 110A and the AC power source 110B is branched and supplied to each of the developing rollers 110C, 110M, 110Y, and 110K.

However, unlike FIG. 2, it can be seen that the transfer rollers 130C, 130M, 130Y, and 130K are branched from one transfer high voltage power supply 130A to supply voltage. In addition, four zener diodes 130C2, 130M2, 130Y2 and 130K2).

The high voltages to be applied to the transfer rollers 130C, 130M, and 130Y 130K are different for each of C, M, Y, and K. This is to compensate for the change in the electric field condition to obtain an optimal transfer efficiency. Therefore, a high voltage is gradually applied according to the transfer direction of the transfer belt. As shown in FIG. 3, four zener diodes 130C, 130M, 130Y, and 130K are used as constant voltage elements. In the case of Figure 3, the transfer voltage should be increased in the order of 130Y> 130M> 130C> 130K.

In this manner, the developing high voltage power supply 310, the charging high voltage power supply 320, and the transfer high voltage power supply 330 are continuously applied until the printing is finished. Therefore, the HVPS controller 510 controls the phenomenon by controlling the exposure (not shown) timing.

As an embodiment having the above configuration, when printing is started, the HVPS control unit 510 applies the developing high voltage power supply 310 and the charging high voltage power supply 320 before applying the pre-accident voltage, and at the end of printing. The state of the power supplies 310 and 320 may be controlled to continue to supply power until such time. In this case, the HVPS control unit 510 controls the development by controlling the timing of exposure (in the drawings, the exposure unit is not shown). can do. This is because development cannot occur if the photosensitive member is not exposed.

Although the preferred embodiments of the present invention have been described in detail above, those of ordinary skill in the art to which the present invention pertains may make various changes without departing from the spirit and scope of the present invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Therefore, modifications of the embodiments of the present invention will not depart from the scope of the present invention.

As described above, in the single-pass non-contact developing image forming apparatus, by providing one common power supply (direct current and alternating current power supply) to each of the developing rollers of C, M, Y, and K, the cost and The effect is to reduce the size.

Claims (4)

In the power supply of a non-contact single pass color image forming apparatus using a superimposed power source of direct current and alternating current, A developing high voltage power supply unit supplying overlapping power of direct current and alternating current to a plurality of developing rollers including C, M, Y, and K; A charging high voltage power supply unit supplying charging power to a plurality of charging rollers including C, M, Y, and K; A transfer high voltage power supply for supplying a transfer power to a plurality of transfer rollers consisting of C, M, Y, K, wherein the transfer high voltage power supply branch is branched from one transfer power, and the plurality of transfers made of C, M, Y, K A transfer high voltage power supply for supplying transfer power to rollers, the voltage of the transfer power input to each of the transfer rollers being limited to voltages of different magnitudes by constant voltage elements; And And a control unit for controlling on and off of the power supply units, wherein the developing high voltage power supply unit is included. The power supply device characterized by branching from one of the overlapping power of the direct current and alternating current to supply power to the plurality of developing rollers. The method of claim 1, wherein the control unit When the printing is started, the power supply device characterized in that the charging power is applied simultaneously or first to each charging roller before applying the overlapping power of the direct current and alternating current to the plurality of developing rollers. delete The method of claim 1, wherein the constant voltage devices are Zener diodes, characterized in that the power supply.

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