JP4423923B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to a power supply device, and more particularly to a power supply device that supplies power to a contact-type transfer device.

  Conventionally, a transfer device used in an image forming apparatus such as an electrophotographic copying machine or a printer is sensitized by generating a corona discharge by applying a high voltage to a discharge wire stretched inside a metal shield. Corona discharge type (for example, see Patent Documents 1 to 5) that latent images a toner image on a photosensitive drum, or contact that contacts the surface of the photosensitive drum and transfers the toner image onto the transfer sheet from the surface of the photosensitive drum A mold (for example, see Patent Document 6) is employed.

  FIG. 1 shows a configuration of an image forming apparatus 100 to which a general corona discharge type transfer device is applied. As shown in FIG. 1, the image forming apparatus 100 includes a power transformer 101 that supplies a high voltage therein, a rectifying and smoothing circuit D101 that rectifies and smoothes a current input from the power transformer 101, a capacitor C101, and rectifying and smoothing. The wiring 102 through which the subsequent current flows and the corotron 103 that latently images the surface of the photosensitive drum 104 by performing corona discharge based on the input current.

  On the other hand, the contact-type transfer device does not generate discharge products, and it is easy to reduce the size of the device. Therefore, the contact-type transfer device is used particularly in a small-sized image forming apparatus. FIG. 2 shows a configuration example of an image forming apparatus 200 to which this contact type transfer device is applied.

  As shown in FIG. 2, the image forming apparatus 200 includes a high-voltage power supply 210 having a transfer high-voltage generation circuit 211 and a high-voltage generation circuit 212 for static elimination, and the power input from the high-voltage power supply 210 to the transfer apparatus 201 and static elimination. A high voltage supply device 220 for supplying to the device 202, a charging device 204 for latent image of the photosensitive drum 205, a developing device 203 for attaching toner to the latent imaged photosensitive drum 205, and transfer from the photosensitive drum 205. And a fixing device 207 for fixing the toner transferred onto the paper 206.

  As shown in FIG. 3, the transfer device 201 is a roll formed by covering a metal shaft 2011 with a conductive elastic layer 2012 to a predetermined thickness. The transfer device 201 injects electric charges from the conductive elastic layer 2012 to the back side of the transfer paper 206 based on the high voltage applied to the metal shaft 2011 from the transfer high voltage generation circuit 211, A toner image charged to a predetermined polarity is transferred from the body drum 205.

  Further, the static eliminator 202 opposes the transfer sheet 206 with a needle-like or saw-like electrode 2021 as shown in FIG. 4 in order to separate the transfer paper 206 onto which the toner image has been transferred from the surface of the photosensitive drum 205. Based on the high voltage applied from the high voltage generating circuit 212 for discharging, discharge from the needle-like or saw-like electrode 106 is performed.

  Here, the connection between the high voltage supply device 220 and the high voltage power supply 210 shown in FIG. 2 will be described. The high-voltage power supply 210 is generally disposed on a printed wiring board, and the printed wiring board is connected by a connection portion of the high voltage supply device 220. FIG. 22 shows a connection configuration between the high voltage supply device 220 and the high voltage power supply 210. As shown in FIG. 22, terminals corresponding to each other are provided on the end portion of the high-voltage power supply 210 formed of a printed wiring board and the terminal portion of the high-voltage supply device 220, and these are electrically connected. This structure requires guide rails on both sides of the printed circuit board (high voltage power supply 210) as the length increases.

As shown in FIG. 23, the guide rail of Patent Document 7 includes a long board guide member 301 that guides a printed board, and a fixing member 302 that is fixed to a storage case 310 and holds the board guide member 301 in a predetermined position. I have. The board guide member 301 includes a guide piece 303 that guides the printed board and establishes conduction with the conductive pattern of the printed board. The printed board is inserted into the board guide member 301 fixed to the storage case 310, and the printed board is set at a predetermined position of the storage case 310. In this state, the conductive pattern of the printed board comes into contact with the guide piece 303 of the board guide member 301, and the printed board and the storage case 310 are conducted.
Patent Document 8 also describes a similar technique.

JP 51-131635 A Japanese Patent Publication No.57-20630 Japanese Patent Application Laid-Open No. 64-40959 Japanese Utility Model Publication No. 2-55266 Japanese Utility Model Publication No. 5-43167 JP-A-8-160778 Utility Model Registration No. 2504512 JP-A-8-264773

  However, the contact type transfer device 200 combined with the discharging device for charge removal as described above is formed in a cylindrical shape by covering a metal shaft 2011 with a conductive elastic layer 2012 to a predetermined thickness. Therefore, the impedance of the transfer device 201 is about 100 times that the impedance is as low as several MΩ in a high temperature and low humidity environment, whereas the impedance is as high as several hundred MΩ in a low temperature and high humidity environment. There is a problem of changing. This means that under constant current control, the leakage current changes greatly due to changes in environmental conditions, which leads to difficulty in realizing stable operation.

Here, the characteristic of leakage current under constant current control is shown in FIG. As apparent from FIG. 5, the impedance of the transfer device 201 becomes small under conditions of high temperature and low humidity, for example. Therefore, under constant current control, the voltage applied to the transfer device 201 is reduced, and accordingly, the voltage applied to the wirings 213 and 221 is also reduced. For this reason, the current (leakage current I _L ) that leaks from the transfer device 201 to the charge removal device 202 is also reduced. On the other hand, for example, the impedance of the transfer device 201 increases under conditions of low temperature and high humidity. Therefore, under constant current control, the voltage applied to the transfer voltage 201 increases. For this reason, the current (leakage current I _L ) that leaks from the transfer device 201 to the static elimination device 202 also increases.

  Such a leakage current also occurs in the corona discharge transfer device 100, and similarly causes a problem that it is difficult to realize a stable operation.

  To deal with such a problem, for example, an electrostatic copying apparatus according to Patent Document 1 has an image forming surface having an electrically grounded substrate, a corona discharge electrode shielded by a conductive shield, and the image forming surface has And a plurality of corona generators operating to apply an output current composed of electric charges. Each corona generator is connected to a power supply means for supplying one selected input current and is configured such that a variable portion of this input current flows through the shield. The individual shields are electrically isolated from each other and from the imaging surface and ground. The shield is connected to a feedback circuit that is insulated from the image forming surface and the ground, and is configured such that the variable portion of the input current returns to the power supply means connected to the shield. In such a configuration, the electrostatic copying apparatus has current measurement control means connected between the power supply means and the ground substrate on the image forming surface. As a result, the output current flowing between the corona generator and the image forming surface can be controlled independently of the leakage current to the shield and the output current from the corona generator and other corona generators. It is possible. That is, the input current can be stably controlled without depending on the leakage current from the corona generator.

  Further, the corona discharge device according to Patent Document 2 has a configuration in which a stable plate for stabilizing corona discharge is combined with a discharge electrode that generates corona discharge on a rotating drum having a charging layer by a high voltage of a high-voltage power source. The high-voltage output terminal of the step-up transformer of the high-voltage power source is connected to the discharge electrode, the stabilization plate is connected to the low-voltage terminal of the step-up transformer, the low-voltage terminal is grounded via the current detection resistor, and the rotating drum is grounded Yes. In such a configuration, the corona discharge device has a configuration in which negative feedback is applied to the input side of the step-up transformer so that the voltage generated in the current detection resistor is constant. The current can be kept constant without depending on the leakage current that changes depending on the change.

  The high-voltage discharge current supply method disclosed in Patent Document 3 is a high-voltage discharge current supply method that performs constant current control and reduces control errors due to leakage current in a power supply line that supplies high-voltage discharge current. It is configured to be excluded from the detection signal of the detection circuit. Thereby, it is possible to realize a stable supply of a high-voltage power supply without depending on a leakage current that varies depending on environmental changes such as temperature and humidity.

  Further, the transfer device according to Patent Document 4 includes a corona discharge electrode that transfers a toner image formed on an image carrier onto a transfer paper, a high voltage generation circuit that applies a voltage to the corona discharge electrode, and the high voltage generation circuit. A structure comprising a constant current control circuit provided between the ground and a charge eliminating member for eliminating charges on the transfer material immediately after the transfer by the corona discharge electrode provided at a predetermined interval from the image carrier. In the configuration, the static eliminator is electrically connected to a connection portion between the high voltage generation circuit and the constant current control circuit, and a diode is provided between the connection portion and the ground. As a result, according to Patent Document 4, it is possible to prevent a leakage current that changes depending on environmental changes such as temperature and humidity from flowing into the constant current control circuit, whereby the output current does not depend on the leakage current. Can be stably supplied to the corona discharge electrode.

  Furthermore, the transfer separation device according to Patent Document 5 is provided with a corona discharge electrode for transferring a toner image formed on an image carrier to a transfer material, a high voltage output terminal for applying a voltage to the corona discharge electrode, and a ground. A high voltage generating means having a feedback terminal to which a current is fed back, a current detecting means interposed between the feedback terminal and the ground, and a predetermined distance with respect to the image carrier. And a separating unit that separates the transfer material immediately after the transfer is completed by applying a voltage having a polarity opposite to the applied voltage, and the separating unit includes the feedback terminal and the separation unit. It connects in the connection circuit with a current detection means, and the resistance element is interposed between this connection part and the said current detection means. As a result, in Patent Document 5, the power source is shared between the transfer and the separation, and the current for driving the transfer can be controlled at a constant current regardless of changes in environmental conditions and the like.

  For example, in Patent Document 6, in a contact type transfer device used in combination with a discharge device for charge removal, an electrical line for bypassing leakage current leaking from the transfer device to the discharge device for charge removal High-voltage generating means for discharging the conductive roll-shaped member from the low-voltage side of the high-voltage generating means for applying a constant DC current to the discharging device for static elimination, and detection for detecting the transfer current flowing through the conductive roll-shaped member It has the structure connected between the parts. Thus, in Patent Document 6, it is possible to obtain a transfer current having a predetermined value without depending on a leakage current that changes depending on environmental changes such as temperature and humidity.

  However, the leakage current does not occur only between the transfer device and the static eliminator or between the corona generator and the shield, as mentioned in the above-mentioned patent documents. It also occurs between the wirings that do. For this reason, in the configurations according to the above-mentioned Patent Documents 1 to 6, there is a problem that it is impossible to completely eliminate the influence of the leakage current.

  In particular, in a contact-type transfer device in which a static eliminator is disposed close to each other, wirings that connect these and the high-voltage power supply are often close to each other, so that leakage current between the wires greatly affects.

  In addition, the contact-type transfer device has a smaller transfer current than the corona discharge-type transfer device, so the influence of the leakage current is large, and the effect of the leakage current is sufficiently reduced to achieve stable operation. There is also a problem that must be done.

  Further, in the conventional method of connecting the high voltage supply device 220 and the high voltage power source 210 shown in FIG. 22, in order to fix the substrate separately from the terminal portion that makes electrical connection with the printed circuit board on which the high voltage power source 210 is formed. Therefore, there is a problem that the apparatus configuration is increased in size.

  In Patent Document 7 and Patent Document 8, the problem is how to ensure the stability of conduction between the guide rail and the storage case, and the problem of how to reduce the size of the power supply device is not considered.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a power supply device that can stably supply power without depending on changes in environmental conditions and that can reduce the size of the device. And

In order to achieve this object, the image forming apparatus according to claim 1 outputs a constant current to the first wiring connected to the contact type transfer unit in order to supply a constant current to the contact type transfer unit. 1. A high voltage circuit board on which a high voltage generating circuit 1 and a second high voltage generating circuit that outputs a constant current to a second wiring connected to a charge eliminating unit that neutralizes the transfer sheet charged by the contact type transfer unit are formed. Between the first wiring and the second wiring, and extending along the first wiring, one end of the first high-voltage generating circuit and the constant current source. For absorbing leakage current leaking from the first wiring toward the second wiring at the other end, and for feeding back the absorbed leakage current to the first high voltage generation circuit. Conductor patterns and the first wiring and the second wiring as bus bar wiring And an image forming unit that forms an image, the supply unit supplying a constant current output from the high-voltage circuit board to the transfer unit and the charge removal unit, and the contact type transfer unit and the charge removal unit. An apparatus body, and the supply device slides the high-voltage circuit board and guides it to a predetermined position of the supply device, and is arranged along the guide groove, and the first wiring A plurality of first terminals connected to one of the second wiring and the conductor pattern, and the high-voltage circuit board is inserted into the guide groove and guided to the predetermined position. , and a plurality of second terminals making electrical connection between the plurality of first individual in contact with respective first terminals pins.
In the present invention, the supply device is provided with a guide groove for guiding the high-voltage circuit board to a predetermined position and a first terminal arranged along the guide groove, and the high-voltage circuit board is guided to a predetermined position of the supply device. In this case, by providing the second terminal that is electrically connected to the first terminal, the constant current output from the high-voltage circuit board is supplied to the transfer unit and the neutralization unit of the main body of the image forming apparatus. Can do. By taking the electrical connection between the high-voltage circuit board and the supply device with such a configuration, it is not necessary to separately provide a member such as a harness, and the device can be miniaturized. In addition, by providing a conductor pattern that extends between the first wiring and the second wiring so as to extend along the first wiring, the first wiring is changed to the second wiring. The leaking leakage current can be fed back to the first high voltage generation circuit. For this reason, without considering the influence of leakage current, the distance between the first wiring and the second wiring (wiring interval) can be further shortened, and the device can be further miniaturized.

The image forming apparatus according to claim 2 is the image forming apparatus according to claim 1, wherein each of the plurality of first terminals has a contact surface in contact with the second terminal inserted into the guide groove. In the sliding direction in which the high-voltage circuit board is slid, it has a structure that is divided into two or more. With this configuration, even when the first terminal is inclined and the contact surface of the first terminal cannot be completely in contact with the circuit board, the contact location that contacts the second terminal of the circuit board by a structure that is broken into two or more. To increase the connectivity with the circuit board.

The image forming apparatus according to claim 3 is the image forming apparatus according to claim 1 or 2, wherein each of the plurality of first terminals has a tip portion further than a contact surface in contact with the second terminal. The high-voltage circuit board inserted into the guide groove is bent to the opposite side. With this configuration, it is possible to increase the strength of the contact terminal and to contact the terminal of the circuit board with a stable strength.

The image forming apparatus according to claim 4, said at an image forming apparatus according to any one of claims 1 to 3, the protrusion is provided in the guide groove, the first contact terminal and the projecting portion The circuit board is sandwiched from above and below. With this configuration, when the circuit board is slid into the guide groove, the projecting portion comes into contact with the circuit board to reduce the contact area, and the circuit board can be easily slid. Further, by sandwiching the circuit board between the first terminal and the protrusion from above and below, the connectivity of the circuit board can be improved and the circuit board can be fixed.

The image forming apparatus according to claim 5 is the image forming apparatus according to any one of claims 1 to 4, wherein the plurality of first terminals are provided in a housing of the supply device along the guide groove. A wall portion made of an insulating material is provided between the adjacent first terminals that are arranged . With this configuration, a creeping distance between the first terminals can be secured, so that the first terminals can be arranged close to each other, and the device configuration can be reduced in size.

According to the present invention, it is possible to provide an image forming apparatus in which stable power supply is possible without depending on changes in environmental conditions and the apparatus configuration is downsized.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  First, Embodiment 1 according to the present invention will be described in detail with reference to the drawings. In this embodiment, in the contact type transfer device, the leakage current between the wiring connecting the high-voltage power supply and the transfer device or the static eliminator is fed back to depend on the leakage current that changes depending on environmental conditions such as temperature and humidity. This is to realize a stable operation without any problems.

  FIG. 6 is a block diagram showing a schematic configuration of an image forming apparatus 1A having a contact-type transfer device according to this embodiment. As shown in FIG. 6, the image forming apparatus 1 </ b> A includes a high voltage power source 10 </ b> A having a transfer high voltage generation circuit 11 and a charge removal high voltage generation circuit 12, and a high voltage output from the transfer high voltage generation circuit 11. A high-voltage supply device 20A that supplies the transfer device 31 with the high voltage output from the high-voltage generating circuit 12 for charge removal to the charge removal device 32, and a charging device 34 that latently images the photosensitive drum 35 are latent images. A developing device 33 that attaches toner to the photosensitive drum 35, a transfer device 31 that transfers the toner image attached to the photosensitive drum 35 to the transfer paper 36, and a static eliminator that neutralizes the transfer paper 36 charged during the transfer. 32 and a fixing device 37 for fixing the toner image transferred onto the transfer paper 36.

  In this configuration, the transfer high voltage generation circuit 11 and the transfer device 31 are electrically connected via the wirings 13 and 21. Further, the high voltage generating circuit 12 for static elimination and the static eliminator 32 are electrically connected via wirings 14 and 22.

  Here, as shown in FIG. 3, the transfer device 31 has a configuration in which a metal shaft 2011 is covered with a conductive elastic body layer 2012 to a predetermined thickness and formed into a roll shape. Therefore, by applying a high voltage from the transfer high voltage generation circuit 11 to the metal shaft 2011, electric charges (also referred to as transfer current) are injected from the conductive elastic layer 2012 to the back side of the transfer paper 36. As a result, the toner image charged to a predetermined polarity is transferred onto the transfer paper 36 from the photosensitive drum 35.

  Further, the static eliminator 32 has a configuration in which needle-like or saw-like electrodes 2021 as shown in FIG. 4 are arranged so as to face the transfer paper 36. In this configuration, by applying a high voltage applied from the high-voltage generating circuit 12 for discharging to the electrode 2021, a discharge for discharging the charge charged from the electrode 2021 to the transfer paper 36 is performed, whereby a transfer is performed. The potential difference between the paper 36 and the photosensitive drum 35 is eliminated, and the transfer paper 36 can be separated from the surface of the photosensitive drum 35.

  The transfer high voltage generator 11 is grounded via a constant current source 15 that is a first constant current source, and is configured such that a constant current flows through the transfer high voltage generator circuit 11. Similarly, the high voltage generation circuit 12 for static elimination is grounded via a constant current source 16 that is a second constant current source, and is configured such that a constant current flows through the high voltage generation circuit 12 for static elimination. That is, the transfer high voltage generation circuit 11 and the static elimination high voltage generation circuit 12 are subjected to constant current control.

The current flowing in the transfer high voltage generation circuit 11 is a so-called transfer current I _T1 and is input to the shaft 2011 in the transfer device 31 via the wiring 13 in the high voltage power supply 10A and the wiring 21 in the high voltage supply device 20A. The A part of the transfer current that flows into the shaft 2011 (hereinafter referred to as I _T2 ) flows into the photosensitive drum 35 via the transfer paper 36 and then flows out to the ground.

  On the other hand, the current flowing in the high voltage generating circuit 12 for static elimination is a so-called static elimination current, and is input to the electrode 2021 in the static elimination device 32 via the wiring 14 in the high voltage power supply 10A and the wiring 22 in the high voltage supply device 20A. The The static elimination current that has flowed into the electrode 2021 flows into the transfer paper 36, thereby eliminating the charging of the transfer paper 36.

In this embodiment, as in the configuration found in a general image forming apparatus, when the transfer device 31 and the charge removal device 32 are arranged close to each other, the design element, that is, the viewpoint of downsizing the image forming apparatus 1A. Accordingly, the wirings 13 and / or 21 connecting the transfer high voltage generation circuit 11 and the transfer device 31 and the wirings 14 and / or 22 connecting the static elimination high voltage generation circuit 12 and the charge removal device 32 are arranged close to each other. Is done. More specifically, for example, the wirings 13 and 14 and the wirings 21 and 22 are configured by a line in which harnesses or the like are assembled, thereby saving space. However, in such a configuration, a leakage current I _L2 is generated from the wirings 13 and 21 to the wirings 14 and 22. The leakage current I _L2 changes depending on changes in environmental conditions such as temperature and humidity. This is because the impedance of the transfer device 31 changes depending on the environmental conditions.

For example, the impedance of the transfer device 31 becomes small under conditions of high temperature and low humidity. Therefore, under constant current control, the voltage generated by the transfer high voltage generation circuit 11, that is, the voltage applied to the transfer device 31, decreases, and the voltage applied to the wirings 13 and 21 decreases accordingly. . Therefore, the potential difference between the wiring 13 and the wiring 14 and the potential difference between the wiring 21 and the wiring 22 are reduced, and the leakage current from the wiring 13 to the wiring 14 and the leakage current from the wiring 21 to the wiring 22 are also reduced. On the other hand, for example, the impedance of the transfer device 31 increases under conditions of low temperature and high humidity. Therefore, under constant current control, the voltage generated by the transfer requirement voltage generation circuit 11, that is, the voltage applied to the transfer voltage 31, increases, and accordingly, the voltage applied to the wirings 13 and 21 also increases. Therefore, the potential difference between the wiring 13 and the wiring 14 and the potential difference between the wiring 21 and the wiring 22 are increased, and the leakage current from the wiring 13 to the wiring 14 and the leakage current from the wiring 21 to the wiring 22 are also increased. Note that the total value of the leakage current from the wiring 13 to the wiring 14 and the leakage current from the wiring 21 to the wiring 22 is I _L2 .

Further, as the leakage current, there is a current that leaks directly from the transfer device 31 to the static eliminator 32 (via an air gap) or via the transfer paper 36 as well as between the wirings. Let this leakage current be I _L1 . This leakage current I _L1 also changes depending on the change in environmental conditions, like the above-described leakage current I _L2 .

Accordingly, the transfer current I _T1 output from the transfer high voltage generation circuit 11 decreases to I _T2 (= I _T1 −I _L2 ) in the wirings 13 and 21 before being input to the transfer device 31. Further, in the transfer device 31, it is reduced to I _T3 (= I _T2 −I _L1 = I _T1 − (I _L1 + I _L2 )).

Most of the leakage current I _L2 is occupied by the leakage current from the wirings 13 and 21 to the wirings 14 and 22. Therefore, in the present embodiment, a conductor pattern that absorbs the leakage current I _L2 from the wiring 13 and the wiring 21 is formed between the wiring 13 and the wiring 14 and between the wiring 21 and the wiring 22. Then, the leakage current I _L2 is _{fed back} to the transfer high voltage generation circuit 11. In other words, the transfer current I _T1 , which is a constant current, is generated in the first wiring composed of the wirings 13 and 21 connected to the transfer device 31, which is the transfer means, and the transfer high voltage, which is the first high voltage generation means, is generated. In the configuration inputted from the circuit 11, a first conductor pattern for returning the leakage current I _L2 from the first wiring to the first high voltage generating means is provided. As a result, the loss of the transfer current I _T1 can be fed back, and the transfer current I _T2 can be more accurately controlled with constant current.

  In the present embodiment, jumper wires 2 and pattern wirings 3 formed on the printed board 10a as shown in FIG. 6 are used as the conductor patterns. However, the jumper line 2 may be formed with other conductor patterns such as pattern wiring, and the pattern wiring 3 may be formed with other conductor patterns such as jumper lines. Furthermore, the first conductor pattern is not limited to the two conductor patterns described above, and may be composed of one conductor pattern or a plurality of electrically connected conductor patterns.

One end of the jumper wire 2 and one end of the pattern wiring 3 are electrically connected at a coupling portion between the high voltage power source 10A and the high voltage supply device 20A. The other end of the pattern wiring 3 is connected to a wiring (for example, a point X in the drawing) between the transfer high voltage generation circuit 11 and the constant current source 15. The other end of the jumper wire 2 is short-circuited. The jumper line 2 is disposed so as to extend along the wiring 21 inside the high voltage supply device 20A. At this time, the jumper line 2 is disposed at a position closer to the wiring 21 than the wiring 22, for example, between the wiring 21 and the wiring 22. Similarly, the pattern wiring 3 is disposed so as to extend along the wiring 13 on the printed board 10a. At this time, the pattern wiring 3 is disposed closer to the wiring 13 than the wiring 14, for example, between the wiring 13 and the wiring 14. With such a configuration, the leakage current I _L2 from the wirings 13 and 21 can be absorbed by the jumper line 2 and the pattern wiring 3, and this leakage current I _L2 can be _{fed back} to the transfer high voltage generation circuit 11. Therefore, the transfer current I _T2 input to the transfer device 31 can be stably controlled at a constant current, and as a result, a decrease in the transfer current I _T3 flowing into the photosensitive drum 35 can be suppressed. FIG. 7 shows the relationship between the transfer current I _T2 and the leakage currents I _L1 and I _L2 according to this embodiment.

As shown in FIG. 7, although there is a leakage current I _L2 radiated from the wirings 13 and 21, this leakage current I _L2 is fed back to the transfer high voltage generation circuit 11 via the jumper line 2, so that an influence is exerted. As a result, only the attenuation due to the leakage current I _L1 appears in the transfer current I _T2 . That is, the loss of the transfer current I _T1 is greatly reduced, and a stable transfer current I _T2 can be obtained. In FIG. 7, the left graph shows leakage current characteristics with respect to temperature and humidity, and the right graph shows transfer current characteristics with respect to temperature and humidity.

  In the above description, the high-voltage power supply 10A, which is a power supply device, includes, for example, a high voltage generator 11 for transfer, a high voltage generator circuit 12 for static elimination, and a constant current source 15 on a printed board 10a on which wirings 13 and 14 and a ground pattern are formed. , 16 are mounted. Further, the high voltage supply device 20A is configured as a module, and wirings 21 and 22 each including, for example, a harness in which a plurality of lines are gathered are provided. FIG. 8 shows a coupling portion with the high voltage power supply 10A in the high voltage supply device 20A, and FIG. 9 shows a connection portion with the high voltage supply device 20A in the high voltage power supply 10A.

  FIG. 8 is an external view showing a configuration in which the printed circuit board 10a is mounted in the high voltage supply apparatus 20A. FIG. 9A is an external view showing a configuration of a part of an end mounted on the high voltage supply device 20A on the first surface of the printed circuit board 10a constituting the high voltage power source 10A. b) is an external view showing a configuration of a second surface opposite to the first surface shown in FIG.

  As shown in FIG. 8, the high voltage supply device 20A includes a slide rail 25 as a configuration for slidingly mounting the high voltage power source 10A formed of the printed circuit board 10a. The slide rail 25 is provided with various terminals protruding with an elastic shape on the side on which the printed circuit board 10a is mounted. Accordingly, the various terminals form an electrical connection with the corresponding terminals on the printed circuit board 10a side while elastically deforming when the printed circuit board 10a is mounted. As various terminals, in addition to the input / output terminals (CB, DAVE, BDR), a transfer terminal (BTR) 23 connected to the wiring 21, a static elimination terminal (DTS) 24 connected to the wiring 22, and a jumper wire 2 and a jumper line connecting terminal 2a connected to the terminal 2.

  Further, as shown in FIG. 9A, on the printed circuit board 10a, the first surface facing the terminals (for example, 2a, 23 and 24) when mounted on the high voltage supply device 20A Various terminals are provided at positions corresponding to the terminals. In the following description, the jumper line connection terminal 2a, the transfer terminal 23, and the terminal connected to the charge removal terminal 24 will be described. At a position corresponding to the transfer terminal 23, a transfer high voltage supply terminal 13a is formed for electrical connection therewith. Further, a high voltage supply terminal 14a for charge removal is provided at a position corresponding to the charge removal terminal 24 to form an electrical connection therewith. Further, a jumper line connection terminal 3a for forming an electrical connection with the jumper line connection terminal 2a is provided at a position corresponding to the jumper line connection terminal 2a. In these terminals, the jumper wire connection terminal 3a has an elastic shape, and is configured to be elastically deformed when the jumper wire connection terminal 2a is contacted. Further, the transfer high voltage supply terminal 13a and the charge removal high voltage supply terminal 14a may have an elastic shape like the jumper wire connection terminal 3a. However, the present invention is not limited to this, and the metal pattern or jumper wire is not limited thereto. It may be.

  In the printed board 10a, wirings 13 and 14 and a pattern wiring 3 are formed on the second surface opposite to the first surface, as shown in FIG. 9B. The transfer high voltage supply terminal 13a disposed on the first surface is electrically connected to the wiring 13 formed on the second surface via the via wiring 13b penetrating from the first surface to the second surface. Connected. Similarly, the high-voltage supply terminal 14a for static elimination disposed on the first surface is a wiring formed on the second surface through the via wiring 14b penetrating from the first surface to the second surface. 14 is electrically connected. Similarly, the jumper line connecting terminal 3a disposed on the first surface is a pattern wiring formed on the second surface through the via wiring 3b penetrating from the first surface to the second surface. 3 is electrically connected.

  9 is inserted from the direction of the arrow in FIG. 8 and mounted on the slide rail 25, the wiring 13, the wiring 21, the wiring 14, the wiring 22, and the pattern. The wiring 3 and the jumper line 2 are electrically connected to each other. At this time, similarly, various input / output terminals (for example, CB, DAVE, BDR) in the high voltage supply device 20A are also electrically connected to terminals (not shown) in the printed circuit board 10a.

With the configuration as described above, according to the present embodiment, the leakage current I _L2 from the wiring 13 and the wiring 21 can be _{fed back} to the transfer high voltage generation circuit 11, so that the transfer current I _T2 is It becomes possible to perform constant current control stably. As a result, it is possible to suppress the occurrence of transfer defects and fog.

  In addition, Example 1 demonstrated above is only one of the best forms for implementing this invention, and this invention can be implemented in various deformation | transformation, unless it deviates from the meaning. In the above configuration, the static elimination current, which is a constant current, is supplied from the static elimination device 32 as the static elimination means to the second wiring consisting of the wirings 14 and 22 from the high voltage generation circuit 12 for static elimination as the second high voltage generation means. The case of inputting has been described with reference to an example. However, the present embodiment is not limited to this, and the present invention is similarly applied to a case where a constant voltage is applied from the second high voltage generating means to the second wiring. It is possible.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings. In the first embodiment described above, the leakage current from the wirings 13 and 21 connected to the transfer high voltage generation circuit 11 is fed back to the transfer high voltage generation circuit 11, so that the transfer current I _T2 can be stably stabilized. Was configured to control. However, the leakage current I _L2 fed back from the jumper line 2 and the pattern wiring 3 to the transfer high voltage generation circuit 11 in the first embodiment includes the leakage current from the wiring 22 and the wiring 14 (this is I _L3 ). include. Therefore, in this embodiment, a configuration for feeding back the leakage current from the wirings 14 and 22 to the high voltage generating circuit 12 for static elimination is added to the configuration according to the first embodiment. Thereby, in this embodiment, more accurate constant current control becomes possible. Hereinafter, the configuration of the image forming apparatus 1B according to the present embodiment will be described in detail with reference to the drawings.

  FIG. 10 is a block diagram showing a schematic configuration of the image forming apparatus 1B according to the present embodiment. As shown in FIG. 10, in the image forming apparatus 1B, the high voltage power supply 10A and the high voltage supply apparatus 20A are replaced with the high voltage power supply 10B and the high voltage supply apparatus 20B in the same configuration as the image forming apparatus 1A shown in FIG. ing.

  The high-voltage power supply 10B has a configuration similar to that of the high-voltage power supply 10A, and the pattern wiring 5 parallel to the wiring 14 is disposed closer to the wiring 14 than the pattern wiring 3. One end of the pattern wiring 5 is connected to a wiring (for example, a point Y in the drawing) between the high voltage generating circuit 12 for static elimination and the constant current source 16. The other end of the pattern wiring 5 is connected to the jumper line 4 in the high voltage supply device 20B at a connection portion between the high voltage power supply 10B and the high voltage supply device 20B.

  The high voltage supply device 20B has a configuration similar to that of the high voltage supply device 20A, and a jumper wire 4 extending along the wiring 22 is disposed in the vicinity of the jumper wire 2 with respect to the wiring 22. One end of the jumper line 4 is connected to the pattern wiring 5 at a connection portion between the high voltage power supply 10B and the high voltage supply device 20B, and the other end is short-circuited.

With the above configuration, the leakage current I _L2 from the wiring 13 and the wiring 21 is input to the pattern wiring 3 and the jumper line 2 and fed back to the transfer high voltage generation circuit 11 as in the first embodiment. In addition to this action, in this embodiment, the leakage current I _L3 from the wiring 14 and the wiring 22 as the second leakage current is input to the pattern wiring 5 and the jumper line 4 as the second conductor pattern to eliminate static electricity. Return to the high voltage generation circuit 12. Accordingly, the leakage component of the charge eliminating current flowing through the wiring 14 and 22 (leakage current IL3) can be prevented from entering the high-voltage generating circuit 11 for transfer, more precisely the transfer current I _T2 can be constant current control It becomes. The second conductor pattern is not limited to the two conductor patterns described above, and may be composed of one conductor pattern or a plurality of electrically connected conductor patterns.

Next, the relationship between the transfer current I _T2 and the leakage currents I _L1 and I _L2 according to this embodiment will be described with reference to FIG. As is clear from FIG. 11, in this embodiment, the leakage current I _L1 is reduced as compared with the leakage current I _L1 (see FIG. 7) according to the first embodiment, whereby the transfer current I _T2 is reduced. It shows more stable characteristics. In FIG. 11, the left graph shows leakage current characteristics with respect to temperature and humidity, and the right graph shows transfer current characteristics with respect to temperature and humidity.

As described above, according to the present embodiment, the leakage current I _L2 from the wiring 13 and the wiring 21 is _{fed back} to the transfer high voltage generation circuit 11, and the leakage current I _L3 from the wiring 14 and the wiring 22 is used for static elimination. Since the feedback to the high voltage generation circuit 12 is possible, the transfer current I _T2 can be controlled with constant current more stably. As a result, it is possible to further suppress the occurrence of transfer defects and fog. Other configurations are the same as those in the first embodiment, and thus the description thereof is omitted here.

  In addition, Example 2 demonstrated above is only one of the best forms for implementing this invention, and this invention can be implemented in various deformation | transformation, unless it deviates from the meaning.

  Next, Example 3 of the present invention will be described in detail with reference to the drawings. FIG. 12 is a block diagram illustrating a schematic configuration of an image forming apparatus 1C according to the present embodiment. As shown in FIG. 12, in the image forming apparatus 1C according to the present embodiment, the high voltage power supply 10A is replaced with the high voltage power supply 10C in the image forming apparatus 1A according to the first embodiment.

The high voltage power supply 10C has a configuration in which a resistor R1 as a resistance element is connected in series on the wiring connecting the pattern wiring 3 and the point X in the same configuration as the high voltage power supply 10A. By connecting the pattern wiring 3 to the point X via the resistor R1 in this way, the potentials of the pattern wiring 3 and the jumper line 2 can be increased. That is, the potential difference between the wiring 13 and the wiring 21 and the pattern wiring 3 and the jumper line 2 can be reduced. As a result, the leakage current I _L2 from the wirings 13 and 21 to the pattern wiring 3 and the jumper line 2 can be reduced. For the same reason, the potential difference between the wiring 14 and the wiring 22 and the pattern wiring 3 and the jumper line 2 can be reduced. Therefore, the leakage current I _L3 from the wiring 14 and 22 to the pattern wiring 3 and the jumper line 2 can be reduced. Can also be reduced. For these reasons, the transfer current I _T2 can be controlled more stably and at a constant current.

  Here, the resistance value of the resistor R1 is preferably a sufficiently large value, for example, 10 MΩ or more, compared with the impedances of the transfer high voltage generation circuit 11 and the high voltage generation circuit 12 for static elimination. As a result, the potential of the pattern wiring 3 and the jumper line 2 can be kept at a sufficiently high value. Other configurations are the same as those in the first embodiment, and thus the description thereof is omitted here.

FIG. 13 shows the relationship between the transfer current I _T2 and the leakage currents I _L1 and I _L2 according to this embodiment. As apparent from FIG. 13, in this embodiment, the leakage current I _L1 is reduced as compared with the leakage current I _L1 (see FIG. 7) according to the first embodiment, so that the transfer current I _T2 is reduced. It shows more stable characteristics. In FIG. 12, the left graph shows leakage current characteristics with respect to temperature and humidity, and the right graph shows transfer current characteristics with respect to temperature and humidity.

As described above, according to this embodiment, the potential difference between the wirings 13 and 21 and the pattern wiring 3 and the jumper line 2 and the potential difference between the wirings 14 and 22 and the pattern wiring 3 and the jumper line 2 can be reduced. Therefore, the leakage current I _L2 from the wirings 13 and 21 and the leakage current I _L3 from the wirings 14 and 22 can be reduced, and as a result, the transfer current I _T2 can be more stably controlled at a constant current. It becomes. As a result, it is possible to further suppress the occurrence of transfer defects and fog.

The third embodiment described above is only one of the best modes for carrying out the present invention, and the present invention can be implemented with various modifications without departing from the gist thereof. For example, in the above configuration, the end of the resistor R1 connected to the point X is not limited to this configuration, and may be grounded, for example. Even with such a configuration, the transfer current I _T2 can be sufficiently constant-current controlled. Further, the resistance element is not limited to the wiring connecting the pattern wiring 3 and the point X, but may be provided on the wiring connecting the pattern wiring 5 and the point Y as in the second embodiment, for example. As a result, the potentials of the pattern wiring 5 and the jumper line 4 can be kept high, and the leakage current I _L3 from the wirings 14 and 22 can be reduced. At this time, the end of the resistance element opposite to the end connected to the pattern wiring 5 may be grounded.

  Next, other examples of the configuration for connecting the jumper line 2 (may include 4) and the pattern wiring 3 (may include 5) in each of the above-described embodiments will be described below with reference to the drawings. To do. In the following description, an example based on the configuration according to the second embodiment will be described.

  FIG. 14 is a diagram illustrating a configuration of pattern wirings 3 and 5 and connection terminals (jumper line connection terminals 3a and 5a) obtained by applying the configuration illustrated in the first embodiment to the second embodiment. 14A is an external view showing a configuration of a part of an end mounted on the high-voltage supply device 20B on the first surface of the printed circuit board 10a constituting the high-voltage power supply 10B. b) is an external view showing a configuration of a second surface opposite to the first surface shown in FIG.

  As shown in FIGS. 14A and 14B, the high-voltage power supply 10B in the second embodiment derived from the first embodiment is a printed circuit board corresponding to the jumper line connection terminal 2a (see FIG. 8) in the high-voltage supply device 20B. A jumper line connection terminal 3a is provided at a position on 10a, and this is connected to a pattern wiring 3 formed on the second surface via a via wiring 3b penetrating from the first surface to the second surface of the printed board 10a. Electrically connected. Further, in the high voltage supply device 20B, a jumper line connection terminal electrically connected to the jumper line 4 (referred to as 4a) is provided between the jumper line connection terminal 2a and the static elimination terminal 24. It has been. Therefore, the jumper line connection terminal 5a is provided on the first surface of the printed circuit board 10a at a position corresponding to the jumper line connection terminal 4a connected to the jumper line 4, and this is the first surface from the first surface of the printed circuit board 10a. 2 is electrically connected to the pattern wiring 5 formed on the second surface via the via wiring 5b penetrating to the second surface. These jumper wire connection terminals have an elastic shape, and are configured to form an electrical connection while being elastically deformed when they come into contact with the corresponding terminals.

  FIG. 15 shows a first variation having a configuration different from that of FIG. FIG. 15A is an external view showing a configuration of a part of an end mounted on the high voltage supply device 20B on the first surface of the printed board 10a constituting the high-voltage power supply 10B. b) is an external view showing a configuration of a second surface opposite to the first surface shown in FIG.

  In FIG. 14, the jumper line connection terminals (3a and 5a) on the printed circuit board 10a side and the jumper line connection terminals (2a and 4a) on the high voltage supply apparatus 20B side have an elastic shape. On the other hand, in the first variation, as shown in FIGS. 15A and 15B, only one of the jumper wire connection terminals on the printed circuit board 10a side or the high voltage supply device 20B side has an elastic shape. The other jumper wire connection terminal is formed in a protruding shape. FIG. 15 illustrates the case where the jumper line connection terminals 53a and 55a on the printed board 10a side are formed in a protruding shape.

  Even in such a configuration, when the printed circuit board 10a is inserted into the slide rail 25, the jumper line connection terminals 2a and 4a and the jumper line connection terminals 53a and 55a are in contact with each other, so that electrical connection is formed. Can do. At this time, the jumper wire connection terminals 2a and 4a are elastically deformed.

  FIGS. 16 and 17 show a second modification example having a configuration different from that of FIGS. 14 and 15. FIG. 16A is an external view showing a configuration of a part of an end mounted on the high voltage supply device 20B on the first surface of the printed circuit board 10a constituting the high-voltage power supply 10B. b) is an external view showing a configuration of a second surface opposite to the first surface shown in FIG. FIG. 17 is an external view showing a configuration in which the printed circuit board 10a is mounted in the high voltage supply device 20B.

  As shown in FIGS. 16 and 17, the second variation is that the jumper wire connection terminals 3a and 5a on the printed board 10a side are connected to the lead wires 63 and 65 and the tips of the lead wires 63 and 65, respectively. The terminals 63a and 65a are replaced, and the jumper wire connection terminals 2a and 4a on the high voltage supply device 20B side are replaced with screw receiving terminals 62a and 64a, respectively, and the screw terminal 63a and the screw receiving terminal 62a are fixed with screws 62, The screwing terminal 65 a and the screw receiving terminal 64 a are fixed with screws 64. Note that the ends of the lead wires 63 and 65 opposite to the ends provided with the screw terminals 63a and 65a are drawn out to the opposite surface (for example, the second surface) via vias provided in the printed circuit board 10a. After that, it is mechanically fixed to the printed circuit board 10a with a fixing material such as solder and is electrically connected to the pattern wirings 3 and 5.

  18 to 21 show a third modification example having another configuration. Also in this embodiment, as shown in FIG. 18, the high-voltage power supply 10 constituted by the printed circuit board 10 a is slide-mounted on the high-voltage supply device 20. In the high voltage supply device 20, as shown in FIG. 19, a groove portion 70 is formed between guide members 76 provided at the lower portion of the slide rail 25, and the printed circuit board 10 a is inserted and slid into the groove portion 70. As shown in FIG. 19, the groove part 70 is provided with a convex part 73. When the printed circuit board 10a is slid into the groove part 70, the convex part 73 comes into contact with the printed circuit board 10a to reduce the contact area. The substrate 10a is easily slid. Note that the high voltage power supply 10 constituted by the printed circuit board 10a is equipped with an AC transformer, a switch, and a bias circuit.

  A contact terminal 72 that protrudes with an elastic shape is disposed at a connection portion of the high voltage supply device 20 with the printed circuit board 10a. The contact terminal 72 is formed as a part of the bus bar 75 for sending the power supplied from the high voltage supply device 20 to the image forming apparatus side. The contact terminal 72 forms an electrical connection with a corresponding terminal on the printed board 10a side while elastically deforming when the printed board 10a is mounted. On the printed board 10a side, as shown in FIG. 20, a jumper wire 71 that contacts the contact terminal 72 is provided. In this embodiment, a nickel plated wire is used as the jumper wire 71. The jumper wire 71 is not particularly limited in shape and material as long as it has conductivity. In this embodiment, the bus bar 75 is used for wiring that is connected to the printed circuit board 10a and transmits power to the image forming apparatus. By using the bus bar 75, a configuration without a harness can be achieved, and the space for attaching and detaching the high-voltage power supply 10 and the high-voltage supply device 20 can be minimized, and attachment / detachment can be facilitated.

  As shown in FIG. 19, the contact terminal 72 is disposed so as to press the printed circuit board 10 a on the convex portion 73. That is, by sandwiching the printed circuit board 10a from above and below between the contact terminal 72 and the convex part 73 provided in the groove part 70, the electrical connection between the printed circuit board 10a and the high voltage supply device 20 can be ensured, The printed circuit board 10 a can be fixed to the high voltage supply device 20.

  As shown in FIG. 21, the contact terminal 72 is divided into two parts in contact with the jumper wire 73. Even when the contact terminal 72 is inclined and the contact surface of the contact terminal 72 cannot be completely in contact with the printed circuit board 10a, the printed circuit board 10a can be contacted with the terminals of the printed circuit board 10a by increasing the number of contact points. The connectivity with the substrate 10a can be improved. Further, the tip portion of the contact terminal 72 is bent so that the tip faces upward as shown in FIG. By setting it as such a bending shape, the intensity | strength of the contact terminal 72 can be maintained and a spring pressure can be stabilized.

  FIG. 21 also shows two adjacent bus bars 75. As shown in FIG. 21, a wall portion 74 is provided at a part of the edge of the bus bar 75. The wall portion 74 is made of an insulating material and is formed to be higher than the thickness of the bus bar 75. For this reason, the creepage distance between the adjacent bus bars 75 can be secured by the wall portion 74, and the insulation distance can be secured even when the bus bars 75 are arranged close to each other. The wall portion 74 also serves to fix the bus bar 75 disposed in the high voltage supply device 20.

  As described above, in this embodiment, the groove portion 70 in which the contact terminal 72 is disposed is provided, and the end portion of the printed circuit board 10a is sandwiched in the groove portion 70 to guide the substrate to a predetermined position. Therefore, there is no need to separately provide a terminal portion for electrical connection with the printed circuit board 10a and a guide rail for fixing the circuit board as in the prior art, and the apparatus can be miniaturized. Further, by providing the pattern wiring 3 and the jumper line 2 for feeding back the leakage current from the wiring to the transfer high voltage generation circuit 11, the leakage current may increase even if the distance between the contact terminals 72 is reduced. The apparatus can be further downsized.

  In the above description, the same reference numerals are given to the same components as those in any of the first to third embodiments, and the description thereof is omitted. The fourth embodiment described above is only one of the best modes for carrying out the present invention, and the present invention can be implemented with various modifications without departing from the spirit of the present invention.

It is a figure which shows schematic structure of the image forming apparatus 100 to which the corona discharge type transfer apparatus by a prior art is applied. It is a figure which shows schematic structure of the image forming apparatus 200 to which the contact-type transfer apparatus by a prior art is applied. FIG. 6 is a diagram showing a configuration of a conventional transfer device 201. It is a figure which shows the structure of the conventional static elimination apparatus. It is a graph which shows the characteristic of the leakage current under the constant current control in a prior art. 1 is a block diagram showing a schematic configuration of an image forming apparatus 1A according to Embodiment 1 of the present invention. 6 is a graph showing a relationship between a transfer current I _T2 and leakage currents I _L1 and I _L2 in Example 1 of the present invention. It is an external view which shows the structure by which the printed circuit board 10a in the high voltage supply apparatus 20A by Example 1 of this invention is mounted | worn. (A) is an external view showing a configuration of a part of an end mounted on the high-voltage supply device 20A on the first surface of the printed circuit board 10a constituting the high-voltage power supply 10A, and (b) is (a). It is an external view which shows the structure of the 2nd surface on the opposite side of the 1st surface shown in FIG. It is a block diagram which shows schematic structure of the image forming apparatus 1B by Example 2 of this invention. 6 is a graph showing a relationship between a transfer current I _T2 and leakage currents I _L1 and I _L2 in Example 2 of the present invention. It is a block diagram which shows schematic structure of 1 C of image forming apparatuses by Example 3 of this invention. It is a graph which shows the relationship between the transfer current I _T2 and the leakage currents I _L1 and I _L2 in Example 3 of the present invention. In Example 4 of this invention, it is a figure which shows the structure of the pattern wiring 3 and 5 obtained by applying the structure illustrated in Example 1 to Example 2, and a connection terminal (jumper line connection terminals 3a and 5a). (A) is an external view showing a configuration of a part of an end mounted on the high-voltage supply device 20B on the first surface of the printed circuit board 10a constituting the high-voltage power supply 10B. It is an external view which shows the structure of the 2nd surface on the opposite side of the 1st surface shown to a). It is a figure for demonstrating the 1st example of a change by Example 4 of this invention, (a) is the 1st surface in the printed circuit board 10a which comprises the high voltage power supply 10B, and is mounted | worn with the high voltage supply apparatus 20B. FIG. 2B is an external view showing a configuration of a second surface on the opposite side of the first surface shown in FIG. It is a figure for demonstrating the 2nd example of a change by Example 4 of this invention, (a) is the 1st surface in the printed circuit board 10a which comprises the high voltage power supply 10B, and is mounted | worn with the high voltage supply apparatus 20B. It is an external view which shows the structure of a part of end which is, and is an external view which shows the structure of the 2nd surface on the opposite side to the 1st surface shown to (a). It is a figure for demonstrating the 2nd example of a change by Example 4 of this invention, and is an external view which shows the structure by which the printed circuit board 10a in the high voltage supply apparatus 20B is mounted | worn. It is a figure which shows the connection method to the high voltage supply apparatus 20 of the high voltage power supply 10. FIG. It is the figure which expanded and displayed the coupling | bond part of the high voltage power supply 10 and the high voltage supply apparatus 20. FIG. It is a figure which shows the jumper line 71 formed on the printed circuit board 10a. It is a figure which shows two adjacent bus bars 75, and is a figure which shows the wall part 74 arrange | positioned between the bus bars 75. FIG. It is a figure which shows the connection method to the high voltage supply apparatus 20 of the conventional high voltage power supply 210. FIG. It is a figure which shows the structure of the guide rail disclosed by patent document 7. FIG.

Explanation of symbols

1A, 1B, 1C Image forming apparatus 2 Jumper wire 2a, 3a, 4a, 5a, 53a, 55a Jumper wire connection terminal 3b, 5b, 13b, 14b Via wiring 3, 5 Pattern wiring 10A, 10B, 10C High voltage power supply 10a Printed circuit board DESCRIPTION OF SYMBOLS 11 High voltage generator circuit for transfer 12 High voltage generator for static elimination 13, 14, 21, 22 Wiring 13a High voltage supply terminal for transfer 14a High voltage supply terminal for static elimination 15, 16 Constant current source 20A, 20B High voltage supply equipment 23 Transfer terminal 24 Static elimination terminal 25 Slide rail 31 Transfer device 32 Static elimination device 33 Developing device 34 Charging device 35 Photosensitive drum 36 Transfer paper 37 Fixing device 62, 64 Screw 62a, 64a Screw receiving terminal 63 Lead wire 63a, 65a Screw fixing Terminal 70 Groove 71 Jumper wire 72 Contact terminal 73 Convex 74 Wall part 75 Bus bar 76 Guide member I _L1 , I _L2 , I _L3 Leakage current I _T1 , I _T2 , I _T3 Transfer current R1 Resistance

Claims (5)

In order to supply a constant current to the contact-type transfer unit, a first high-voltage generating circuit that outputs a constant current to a first wiring connected to the contact-type transfer unit, and a transfer charged by the contact-type transfer unit A high-voltage circuit board formed with a second high-voltage generating circuit that outputs a constant current to a second wiring connected to a static elimination means for neutralizing paper;
Between the first wiring and the second wiring, and disposed so as to extend along the first wiring, one end of the first high-voltage generation circuit and the constant current source A conductor pattern connected to the other wiring, for absorbing a leakage current leaking from the first wiring to the second wiring at the other end, and returning the absorbed leakage current to the first high-voltage generating circuit And a supply device that supplies the constant current output from the high-voltage circuit board to the transfer means and the static elimination means, the first wiring and the second wiring as bus bar wiring,
An image forming apparatus main body for forming an image, including the contact-type transfer unit and the charge eliminating unit;
The supply device is arranged along a guide groove that slides the high-voltage circuit board to guide to a predetermined position of the supply device, and the first wiring, the second wiring, and the conductor. A plurality of first terminals connected to any of the patterns ,
The high-voltage circuit board is inserted into the guide groove, when it is guided to the predetermined position, in contact with each of the plurality of first terminals making electrical connection between the first terminal An image forming apparatus having a plurality of second terminals. Each of the plurality of first terminals has a structure in which a contact surface in contact with the second terminal is broken into two or more in a sliding direction in which the high-voltage circuit board is inserted into the guide groove and slides. The image forming apparatus according to claim 1, wherein: Each of the plurality of first terminals has a tip portion bent further to the opposite side of the high-voltage circuit board inserted into the guide groove than the contact surface that contacts the second terminal. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   4. The image forming apparatus according to claim 1, wherein a protrusion is provided in the guide groove, and the circuit board is sandwiched between the first contact terminal and the protrusion from above and below. 5. . The plurality of first terminals are arranged in the housing of the supply device along the guide groove,
5. The image forming apparatus according to claim 1, wherein a wall portion made of an insulating material is provided between the adjacent first terminals . 6.

Images