KR100465324B1 - apparatus for supplying voltage to a development device in image forming apparatus - Google Patents

Abstract

The developing device voltage supply device of the image forming apparatus according to the present invention connects a high voltage source generating at high pressure, at least one or more developing devices, and a high voltage source and a component of the developing device requiring a voltage to control the supply of voltage from the high voltage source to the developing device. And a voltage switching unit having an intermediate switching terminal portion disposed on the wiring, and a power switching unit arranged between the developer and the developer driving source to interrupt power transmission from the developer driving source to the developing device. The voltage switching unit is disposed with respect to the power switching unit and includes a voltage switching unit for electrically connecting or disconnecting the intermediate switching terminal unit in accordance with the operation of the power switching unit. Therefore, the developing device voltage supply device of the present invention can supply or cut off the voltage to the developing device in accordance with the operation of the power switching unit that transmits or cuts power to each developing device for color printing or copying. It can be configured with a simple structure without using.

Description

Developer for supplying voltage to a development device in image forming apparatus}

The present invention relates to an electrophotographic color image forming apparatus, such as a color copying machine, a color printer, etc., having a plurality of developing apparatuses using an electrophotographic method, and more particularly, to transfer power to each developing unit for color printing or copying. The present invention relates to a developing device voltage supply device of an image forming apparatus capable of supplying or cutting off a high pressure to a developing device according to an operation of a shut-off power switching unit.

In general, the electrophotographic color image forming apparatus 10, such as a color copying machine, a color printer, or the like, has a drum-shaped photosensitive member which is continuously rotated in one direction by a photosensitive member driving source such as a motor (not shown). 11).

Near the outer circumference of the photosensitive member 11, four sliding developers each containing a developer of a charger 12, a laser scanning unit (hereinafter referred to as LSU) 20, yellow, magenta, cyan and black, respectively. (31, 32, 33, 34), the transfer carrier 60, the antistatic lamp 87, and the cleaning static eliminator 80 are arranged at predetermined positions along the rotational direction, respectively.

The charger 12 is a scorotron charger and serves to uniformly charge the photosensitive member 11, and the LSU 20 exposes the photosensitive member 11 in a line shape in the axial direction by a laser light source or the like.

Each of the developing devices 31, 32, 33, 34 is in contact with the photosensitive member 11 while forming a constant developing gap by the spacer 13b, the developing roller 13, the developer accommodating portion 16, and developing And a developer layer thickness regulating member or blade 51 for regulating the layer thickness of the developer attached on the developing roller 13, by a developer driving source (not shown) such as a motor. Each is driven to rotate.

As shown in FIG. 2, power from the developer drive source is transmitted to the drive gear 41 through a power transmission gear train (not shown), and the power transmitted to the drive gear 41 is operated by the power transmission electromagnetic clutch 43. Is transmitted to the driving developing roller gear 48 and the driven developing roller gear 49 through the first and second clutch gears 46 and 47, and the developer supply roller gear through other additional idle gears not shown. Delivered (not shown).

The developer is supplied to the developing roller 13 through the developer supply roller 15 of the developer accommodating portion 16 to which a predetermined high voltage is applied, and applies a predetermined charge injection voltage on the developing roller 13. It is regulated to a thin layer by the developer layer thickness regulating blade 51.

Each of the developing devices 31, 32, 33, 34 is a sliding developing device, which is supported to reciprocate in the developing guide member (not shown), and the cams 35, 36, 37 fixed to the rotating shaft 56, respectively. 38 is moved against the release spring 74 towards the photosensitive member 11. Rotation of the rotation shaft 56 is regulated by an electromagnetic clutch (not shown).

The developing bias voltage is applied to the developing roller 13 during development. This developing bias voltage is equal to the charging polarity of the photosensitive member 11 in the case of negative-positive inversion development.

The transfer carrier 60 electrostatically transfers the color image formed on the photosensitive member 11 to the recording paper P, and the cleaning static eliminator 80 removes the developer remaining on the photosensitive member 11.

Referring to the operation of the image forming apparatus 10 configured as described above, first, when a printing command is given, the photosensitive member 11 is continuously rotated by a photosensitive member driving source (not shown), whereby the photosensitive member 11 is The surface is uniformly charged by the charger 12. When the charged area reaches the color of the first formation, for example, the developing position d of the yellow developing device 31, the electromagnetic clutch of the yellow developing device 31 is energized, whereby the yellow developing device 31 is eccentric. The cam 35 moves in the direction of the photosensitive member 11 and is set in a developing state.

Then, the surface of the photosensitive member 11 is exposed by the LSU 20 to form a yellow electrostatic latent image, and the continuous yellow image from the leading end to the rear end of the image by the yellow developing device 31 at the developing position d. This is developed.

After the formation of the yellow image is completed and the rear end of the image passes the developing position d, the eccentric cam 35 is rotated, whereby the yellow developing device 31 is separated from the photosensitive member 11.

Thereafter, when the tip of the image reaches the color of the image formed second, for example, the shape position e of the magenta developer 32, the electromagnetic clutch of the magenta developer 32 is energized, whereby The magenta developer 32 is set in a developing state by the eccentric cam 36.

At this time, the yellow image formed on the photosensitive member 11 passes through the transfer carrier 60, the antistatic lamp 87, and the cleaner static eliminator 80 in an inoperative state, and is again positioned below the charger 12. In particular, the transfer carrier 60 and the cleaner static eliminator 80 are set in a non-contact state with the photosensitive member 11 except during operation so as not to obscure the image passing therethrough.

The photosensitive member 11 which formed the yellow image in the lower position of the charger 12 is again uniformly charged by the charger 12, and the image corresponding to magenta color is superimposed on the yellow image by the LSU 20, After exposure, it is developed by the magenta developer 32 at the developing position e of magenta. After the image formation of the magenta is completed and the rear end of the image passes through the developing position e of the magenta, the eccentric cam 36 is rotated, whereby the magenta developer 32 is separated from the photosensitive member 11.

Then, when the rear end of the image reaches the color of the image formed at the third time, for example, the developing position f of the cyan developer 33, the eccentric cam 37 is energized by energizing the electromagnetic clutch of the cyan developer 33. C) sets the cyan developing unit 33 to a developing state.

At this time, the composite image of yellow and magenta passing through the transfer carrier 60, the antistatic lamp 87 and the cleaner static eliminator 80 is again located under the charger 12, and the photosensitive member 11 is a charger ( 12) uniformly charged. Then, the composite image of yellow and magenta is exposed by overlapping with the image for the cyan by the LSU 20, and then developed by the cyan developing device 33 at the manifest position f of cyan. After the image shape of cyan is completed and the rear end of the image passes the developing position f of cyan, the eccentric cam 37 is rotated, and the cyan developing device 33 is separated from the photosensitive member 11.

Next, black images are overlapped and formed in the same manner, and the formation of all the images is finished. The color image formed on the photosensitive member 11 is transferred to the recording paper P conveyed synchronously by the recording paper supply section by the transfer transport section 60.

After the transfer, the photosensitive member 11 is discharged by the antistatic lamp 87, and the developer remaining on the surface of the photosensitive member 11 is removed by the rotating brush 81 of the cleaner static eliminator 80 to return to the initial state. do. At this time, the recording paper P on which the image has been transferred is transferred to the recording paper fixing unit, fixed, and discharged to the outside of the apparatus.

As described above, in the conventional image forming apparatus 10, the four-color developing devices 31, 32, 33, and 34 are in contact with the photoreceptor 11 by the eccentric cams 35, 36, 37, and 38 at a constant pressure. By having a sliding structure deviating from (11), the photoconductor 11 is respectively developed with the developing rollers 13 of the four-color developing devices 31, 32, 33, 34 during one rotation cycle, that is, when developing one page. You will be contacted four times at a time. At this time, as shown in FIGS. 3, 4A, and 4B, the developing roller 13, the developer supply roller 15, and the developer layer thickness regulating blades of the developing devices 31, 32, 33, and 34 respectively. Sliding contact terminals 13a, 15a, 51a for voltage supply connected to 51 are provided with a corresponding voltage part of a high voltage power supply (HVPS) 90, that is, a developing roller voltage part (supply, 90a). The supply roller voltage part (Deve, 90b) and the fixed layer contact point (90a ', 90b', 90c ') connected to the developer layer thickness regulating blade voltage part (Blade, 90c) by a wire harness. (FIG. 4A) or away (FIG. 4B).

However, the conventional image forming apparatus 10 has an eccentric cam 35, 36, 37, 38, and a cam driving motor (not shown) to replace the four-color developing devices 31, 32, 33, and 34 during development. ), The configuration is complicated.

In addition, whenever the four-color developing devices 31, 32, 33, and 34 are replaced, the contact shock generated by the photoconductor 11 in contact with the developing roller 13 of each developing device is developing. Directly transmitted to the photosensitive member 11, there is a problem in that the life of the photosensitive member 11 is reduced, causing jitter to reduce the image quality by causing a speed change in the photosensitive member 11.

In addition, a voltage supply device for supplying a high pressure to the developing devices 31, 32, 33, 34 of the image forming apparatus 10, as shown in Figs. 4A and 4B, each developing device is an eccentric cam (35, 36) The sliding contact terminals 13a, 15a, 51a are in sliding contact with the fixed contact terminals 90a ', 90b', and 90c 'when the photosensitive member 11 is contacted or spaced apart by the photosensitive member 11, 37, 38. There was a problem of low reliability.

In order to solve the problem of the conventional image forming apparatus 10 using such a sliding developer 31, 32, 33, 34, as shown in Figs. 5 and 6, the developing roller is in contact with the photosensitive member Another image forming apparatus (not shown) having fixed developing devices 31 ', 32', 33 ', 34' fixed to maintain a constant gap (0.2 mm) without being spaced apart is proposed and used.

The developing device voltage supplying device of this image forming apparatus comprises a high-pressure supply source 90 'having a developing roller voltage portion 90d, a developer supply roller voltage portion 90e, and a developer layer thickness regulating blade voltage portion 90f. Fixed contacts of the developing devices 31 ', 32', 33 ', 34' arranged with a predetermined gap with respect to the photosensitive member instead of the developers 31 ', 32', 33 ', 34' contacting or spaced apart from the photosensitive member. Terminal 13a ', 15a', 51a ', and voltage contacts 90d, 90e, 90f of the high-voltage source 90' and fixed contact terminals of the respective developing devices 31 ', 32', 33 ', 34'. And a connecting printing circuit board (PCB) 95 for connecting the 13a ', 15a', and 51a '.

The connecting PCB 95 has three PCB input terminals 95d, 95e, 95f connected to the voltage portions 90d, 90e, 90f of the high voltage source 90 'by a wire harness, each of the developer 31', 32 ', First and second terminals connected to the fixed contact terminals 13a ', 15a' and 51a 'of each developer through the first, second and third spring terminals 98d, 98e and 98f of 33' and 34 '. And third and third PCB output terminals 95d ', 95e', and 95f ', and first and second devices connected to the respective PCB input terminals 95d, 95e and 95f through patterned connection lines on the connection PCB 95, respectively. And first, second, and third outputs switchably connected to the third solenoid input terminals 91d, 91e, 91f and the first, second, and third PCB output terminals 95d ', 95e', 95f '. Four solenoids 91 with switching terminals 91d ', 91e', 91f 'are included.

In the image forming apparatus using the fixed developing devices 31 ′, 32 ′, 33 ′, 34 ′, the developing devices are not in contact with or spaced apart from the photoconductor, thereby reducing problems of image quality degradation and photoreceptor life due to contact shocks. Although the voltage supply device has an advantage of minimizing the high voltage section using a complicated wire harness by using the connection PCB 95, the high voltage is switched by using the connection PCB 95 operated by four solenoids 91. Since the configuration of the high-pressure switching contact is still complicated, there is a problem that high-pressure noise occurs when the developing apparatus is exchanged during development, and the reliability of the high-voltage contact switching is inferior.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a main object of the present invention is to operate according to the operation of a power switching unit installed in each developing unit to transmit or cut off power to each of the plurality of developing units for color printing or copying. The present invention provides a developer voltage supply device for an image forming apparatus which can supply or cut off a voltage to the developer.

It is another object of the present invention to provide a developer voltage supply device of an image forming apparatus having a simple structure without using complicated apparatus or connecting PCB.

1 is a schematic diagram of a conventional color image forming apparatus.

Fig. 2 is a plan schematic view of the power switching unit installed in the developing unit of the color image forming apparatus shown in Fig. 1;

3 is a schematic diagram of a developer voltage supply device of the color image forming apparatus shown in FIG.

4A and 4B are partial plan views illustrating the operation of the developer voltage supply device of FIG.

5 is a schematic diagram of a developer voltage supply device of another color image forming apparatus.

FIG. 6 is a side view illustrating a connection relationship between a high voltage supply source, a voltage switching unit, and respective developers of the developer voltage supply device shown in FIG. 5; FIG.

7 is a schematic plan view of a developer voltage supply device of a color image forming apparatus according to a preferred embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: image forming apparatus 11: photosensitive member

13, 113: developer roller 15: developer feed roller

31, 31 ', 32, 32', 33, 33 ', 34, 34', 131: Developer

41, 141: drive gear 43, 143: electromagnetic clutch

46, 47, 146, 147: clutch gear 48, 148: driving developing roller gear

49: driven developing roller gear 90, 90 ', 190: high pressure supply source

91: solenoid 95: connection printed circuit board

100: voltage switching unit 110: voltage switching

120: return unit 130: intermediate switching terminal connection / blocking member

132: fixed portion 140: intermediate switching terminal portion

142: power switching unit 148b: drive helical gear

111, 149: driven helical gear

In order to achieve the object of the present invention as described above, the present invention provides a high-pressure source for generating a high pressure, at least one or more developers, a component of a developer that requires a high-pressure source and a voltage to interrupt the voltage supply from the high-pressure source to the developer. A voltage switching unit having an intermediate switching terminal portion disposed on a connecting line, and a power switching unit disposed between the developer and the developer driving source to interrupt power transfer from the developer driving source to the developing device, wherein the voltage is supplied to the developing device. In the apparatus, the voltage switching unit is arranged with respect to the power switching unit to provide a developer voltage supply device of the image forming apparatus including a voltage switching unit for electrically connecting or disconnecting the intermediate switching terminal portion in accordance with the operation of the power switching unit.

In a preferred embodiment, the voltage switching unit comprises: a drive helical gear formed in the power switching unit, a first driven helical gear disposed in the chassis of the power switching unit to engage with the drive helical gear, and a first force generated by the rotational force of the drive helical gear. And an intermediate switching terminal connection / blocking member operative to electrically connect or disconnect the intermediate switching terminal portion in accordance with the axial thrust of the driven helical gear.

The drive helical gear is arranged to drive a second driven helical gear formed in one of the components of the developer. Optionally, the drive helical gear may be coaxially formed with the drive gear formed in the power switching unit to engage the driven gear formed in one of the components of the developer for driving one of the components of the developer.

The intermediate switching terminal connection / blocking member may include a conductive part electrically connecting the intermediate switching terminal part, and the conductive part may be connected to the shaft when the shaft of the first driven helical gear is axially moved by the axial thrust of the first driven helical gear. And a fixing part for fixing the conductor part to the shaft of the first driven helical gear so as to move to the connection position for electrically connecting the intermediate switching terminal part and to the blocking position for disconnecting the connection.

The intermediate switching terminal connection / blocking member may further include a return unit for returning the conducting unit to the blocking position when the driving helical gear is stopped and the first driven helical gear does not generate a thrust.

Preferably, the return portion is composed of an elastic spring supported at one end by the shaft of the first driven helical gear and at the other end by the chassis of the power switching unit.

Hereinafter, the developer voltage supply device of the image forming apparatus according to the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

7, an embodiment of the developer voltage supply device of the present invention is schematically illustrated.

In the image forming apparatus to which the developer voltage supply device of the present invention is applied, a drum-type photosensitive member (not shown) for forming an electrostatic latent image by using potential characteristics of a surface, and one developing roller 113 are fixed to the photosensitive member, respectively. There is a fixed developer 131 (only one shown) of four colors, yellow, magenta, cyan and black, which are fixed with a gap, for example, a gap of 0.2 mm.

Each developing unit 131 has a developing roller 113, a developer accommodating part (not shown), like the sliding developing devices 31, 32, 33, 34 of the image forming apparatus 10 shown in FIG. It consists of a developer supply roller (not shown), and a developer layer thickness regulating blade (not shown) for regulating the layer thickness of the developer installed on the developing roller 113, by a developer driving motor (not shown). Each is driven to rotate.

As shown in FIG. 7, power from the developer drive motor is transmitted to the power switching unit 142 of each developer 131 through a power transmission gear train (not shown).

The power switching unit 142 includes a drive gear 141 connected to a power transmission gear train, a drive developing roller gear 148 for transmitting power to the developing roller 113, and a drive gear 141 and a driving developing roller gear ( The power transmission electronic clutch 143 is disposed between the 148 and connects or disconnects the power transmission between the two gears 141 and 148 by a controller (not shown).

The power transmission electromagnetic clutch 143 is disposed to axially move to the clutch shaft 144a of the clutch portion 143 while being engaged with the clutch portion 144 and the driving gear 141 which have electromagnetic force when power is supplied. The first clutch gear 146 having a metal plate 145 attached to or spaced from the clutch portion 144 by the electromagnetic force of the clutch portion 144, and the driving developing roller gear 148 fixed to the end of the clutch shaft 144a. ) Is composed of a second clutch gear 147.

In the 'off' state, the clutch unit 144 engages the power of the first clutch gear 146 engaged with the drive gear 141 with the driving developing roller gear 148 via the clutch shaft 144a. As shown in FIG. 7, the metal plate 145 integrally formed with the first clutch gear 146 is spaced apart from each other, and the power of the first clutch gear 146 is applied to the clutch shaft 144a in the 'on' state. Attach the metal plate 145 to transmit to the second clutch gear 147 through.

The driving developing roller gear 148 has a first gear 148a that meshes with the second clutch gear 147, and a drive helical gear 148b coaxially formed with the first gear 148a. The driving helical gear 148b axially drives the driven helical gear 149 while engaging the driven helical gear 149 for driving the developing roller 113 formed at one end of the shaft 114 of the developing roller 113. Thrust to push in the direction of the arrow (B).

Accordingly, the power transmitted to the drive gear 141 is driven through the first and second clutch gears 146 and 147 according to the operation of the clutch unit 144 of the power transmission electromagnetic clutch 143 by the control unit. It is transmitted to the gear 148 and the driven helical gear 149 for the developing roller, and to the driven helical gear for the developer supply roller (not shown) through another additional helical idle gear not shown.

The developer voltage supply device according to the present invention includes a high pressure supply source 190 having a developer roller voltage section 190d, a developer supply roller voltage section 190e, and a developer layer thickness regulating blade voltage section 190f; Fixed contact terminals 113a, 115a, and 151a connected to the developing roller 113, the developer supplying roller, and the developer layer thickness regulating blades of each developer 131; And three wires 191a, which connect the voltage units 190d, 190e, and 190f of the high voltage source 190 and the fixed contact terminals 113a, 115a, and 151a, respectively, to control the voltage supply to each of the developing units 131. And a voltage switching unit 100 disposed on the power switching unit 142 on 191b and 191c.

The voltage switching unit 100 includes an intermediate switching terminal unit 140 having three pairs of intermediate switching terminals (not shown) disposed on three wirings 191a, 191b, and 191c, and a control unit developing four colors of color. In order to 'on' the power transmission electromagnetic clutch 143 of the power switching unit 142 to drive the developing roller 113 and the developer supplying roller of the corresponding developer 131, the power switching unit 142 And a voltage switching unit 110 arranged to cooperate with the driving developing roller gear 148.

The voltage switching unit 110 is coupled to the chassis 101 of the power switching unit 142 so as to be engaged with the driving helical gear 148b and the driving helical gear 148b of the driving developing roller gear 148 of the power switching unit 142. The axial direction of the driven helical gear 111 generated by the rotational force of the driven helical gear 111 for voltage switching with the shaft 112 arranged to be axially movable, and the driving helical gear 148b, that is, the arrow (B) is composed of an intermediate switching terminal connection / blocking member 130 that operates to electrically connect or cut off the intermediate switching terminal unit 140 according to the direction thrust.

Here, it should be noted that although the driving helical gear 148b and the driven helical gear 149 for the developing roller are shown to be configured in a helical gear shape, the driven helical gear 149 is slid as in the conventional image forming apparatus 10. In order to assist contact between the contact terminals 13a, 15a, 51a and the fixed contact terminals 90a ', 90b', 90c ', the direction of the fixed contact terminals 90a', 90b ', 90c', that is, the direction of the arrow B Since there is no need to generate thrust, the driving helical gear 148b of the driving developing roller gear 148 and the driven helical gear 149 for the developing roller are not formed in the form of a helical gear, but in the form of a spur gear. Can be formed. Therefore, in this case, the driving helical gear for voltage switching is a second gear for driving the driven gear for the developing roller coaxially formed in the form of a spur gear separately from the first gear 148a of the driving developing roller gear 148 (not shown). ) Can be composed of a helical gear (not shown) formed coaxially again.

The intermediate switching terminal connection / blocking member 130 is a conductive part (not shown) consisting of three connecting wires electrically connecting three pairs of intermediate switching terminals of the intermediate switching terminal part 140 to each other, and the driven part is driven helical. It is composed of a fixing part 132 fixed to the shaft 112 of the gear 111.

Intermediate switching terminal connection / blocking member 130 is the blocking position by moving the lead portion in the direction of the arrow (A) when the driving helical gear 148b stops operation and the voltage switching driven helical gear 111 does not generate a thrust. It may further include a return unit 120 to return to. The return part 120 is composed of an elastic spring supported at one end by a stopper 114 formed on the shaft 112 of the driven helical gear 111 and the other end supported by the chassis 101 of the power switching unit 142. It is preferable.

Therefore, when the intermediate switching terminal connection / blocking member 130 is moved in the direction of the arrow B by the shaft 112 of the driven helical gear 111 by the axial thrust of the voltage switching driven helical gear 111, The lead moves to the connecting position where the pair of intermediate switching terminals are electrically connected to each other together with the shaft 112 of the driven helical gear 111, while the driving helical gear 148b stops operation to operate the voltage-driven driven helical. When the gear 111 does not generate a thrust, the conductor part moves in the direction of the arrow A by the elastic spring to return to the blocking position that cuts off the electrical connection of the three pairs of intermediate switching terminals.

As described above, the voltage switching unit 100 of the developer voltage supply device of the present invention is simply according to the operation of the power switching unit 142 without the use of complicated equipment or a connection PCB using a solenoid. Voltage may be supplied or interrupted to 131.

The operation of the developer voltage supply device of the present invention configured as described above will be described with reference to FIG. 7.

First, after a printing command is issued, a latent electrostatic image is formed on the photoconductor, and a part of the photoconductor in which the first color is formed, for example, a yellow electrostatic latent image, is formed by the photoconductor drive source in which the photoconductor is rotated. When moving to the developing position of the 131, the control unit 'turns on' the clutch unit 144 of the power switching unit 142 of the developer 131 while driving the developer driving motor.

As the clutch unit 144 is 'on', power transmitted from the developer drive motor to the drive gear 141 through the gear train is transmitted to the first clutch gear 146, the clutch unit 144, and the second clutch gear ( 147 is transmitted to the first gear 148a of the driving developing roller gear 148 and then to the driven helical gear 149 for the developing roller through the driving helical gear 148b coaxially formed with the first gear 148a. And to a driven helical gear (not shown) for a developer supply roller through another additional helical idle gear not shown. As a result, the developer supplying roller and the developing roller 113 of the developing unit 131 start to rotate in opposite directions to supply the developer to the photosensitive member.

At this time, the voltage switching driven helical gear 111 connected to the driving helical gear 148b of the driving developing roller gear 148 generates thrust in the direction of the arrow B by the rotational force of the driving helical gear 148b. .

As such, when the voltage switching driven helical gear 111 generates thrust in the direction of the arrow B, the intermediate switching terminal connection / blocking member 130 fixed to the lower end of the shaft 112 of the driven helical gear 111 is fixed. The conducting portion of is moved to the connecting position for electrically connecting the three pairs of intermediate switching terminals of the intermediate switching terminal portion 140 with the shaft 112.

As a result, the developing roller voltage section 190d of the high pressure supply source 190, the developer supply roller voltage section 190e, and the developing roller 113 of the developer layer thickness regulating blade voltage section 190f and the developer 131, Three wires 191a, 191b, and 191c connecting the developer supply roller and the fixed contact terminals 113a, 115a, and 151a connected to the developer layer thickness regulating blades are electrically connected to each other in the intermediate switching terminal section 140 through the conductor. Accordingly, the pre-determined voltage from the high pressure source 190 is applied to the developing roller 113, the developer supply roller, and the developer layer thickness regulating blade of the developer 131.

As such, when a voltage is applied, the developer supplied to the developing roller 113 by the developer supply roller has a potential difference between the developer supply roller and the developing roller 113, that is, a developing roller 113 having a relatively low potential. The developer attached to the developing roller 113 is moved to and adsorbed to the surface of the substrate) and the thickness of the developer layer is regulated by the developer layer thickness regulating blade which injects a constant amount of charge into the developer through frictional charging.

Thereafter, the developer moves back to the electrostatic latent image formed on the photosensitive member by the electric field formed by the potential difference between the electrostatic latent image formed on the photosensitive member and the developing roller 113 in a 0.2 mm gap between the photosensitive member and the developing roller 113, thereby making it visible. It is developed as an image.

In this manner, after magenta, cyan, and black images are formed by overlapping in the same manner, the color images formed on the photosensitive member are transferred to recording paper which is synchronously transferred from the recording paper supply unit (not shown) by the transfer carrier (not shown). The recording paper, which is transferred and the image is transferred, is transferred to a recording paper fixing unit (not shown), is fixed, and then discharged to the outside.

As described above, the developing device voltage supply device of the image forming apparatus according to the present invention is connected to the developing device according to the operation of the power switching unit installed in each developing device so as to transmit or cut power to each developing device for color printing or copying. The voltage can be supplied or cut off, and thus can be constructed in a simple structure without the use of complicated instruments or connecting PCBs.

In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and any person having ordinary skill in the art to which the present invention pertains without departing from the spirit and spirit of the present invention as claimed in the claims may have various modifications and Modifications may be made.

Claims (7)

An intermediate switching terminal portion disposed on a wire connecting the high pressure source and at least one developing device, at least one developing device, and the high voltage supply and a component of the developing device requiring a voltage to interrupt a voltage supply from the high pressure source to the developing device A voltage switching unit having a; and a power switching unit arranged between the developing device and the developer driving source to interrupt power transfer from the developing device driving source to the developing device, the developing voltage supply device of the image forming apparatus comprising: The voltage switching unit electrically connects the intermediate switching terminal part when the power switching unit transfers power from the developer driving source to the developing device, and electrically disconnects the intermediate switching terminal part when cutting power transmission from the developer driving source to the developing device. The developing device voltage supply device of the image forming apparatus, further comprising a voltage switching unit. The method of claim 1, wherein the voltage switching unit, A drive helical gear formed on the power switching unit; A first driven helical gear disposed in a chassis of the power switching unit to engage the drive helical gear; And And an intermediate switching terminal connection / blocking member operable to electrically connect or disconnect the intermediate switching terminal portion in accordance with the axial thrust of the first driven helical gear generated by the rotational force of the driving helical gear. Developer voltage supply of forming device. 3. The developer voltage supply device of an image forming apparatus according to claim 2, wherein said driving helical gear is arranged to drive a second driven helical gear formed in one of the components of said developing device. 3. The drive helical gear according to claim 2, wherein the drive helical gear is formed coaxially with a drive gear formed in the power switching unit to engage a driven gear formed in one of the parts of the developing device to drive one of the parts of the developing device. A developer voltage supply device of an image forming apparatus. The method of claim 2, wherein the intermediate switching terminal connection / blocking member, A conductive part electrically connecting the intermediate switching terminal part; And When the shaft of the first driven helical gear is moved in the axial direction by the axial thrust of the first driven helical gear is disconnected the connection position and the connection position for electrically connecting the intermediate switching terminal portion with the shaft And a fixing portion for fixing the lead portion to the shaft of the first driven helical gear to move to the cutoff position. 6. The method of claim 5, wherein the intermediate switching terminal connection / blocking member further comprises a return unit for returning the lead portion to the disconnected position when the drive helical gear is stopped and the first driven helical gear does not generate a thrust. A developer voltage supply device of an image forming apparatus. 7. The developing device of an image forming apparatus according to claim 6, wherein said return portion includes an elastic spring supported at one end by said shaft of said first driven helical gear and at the other end by said chassis of said power switching unit. Voltage supply.