JP2016220420A - Power supply device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device arranged to prevent electrolyte from adhering to a peripheral circuit even when an explosion-proof valve is activated in a simple manner at a small cost.SOLUTION: The power supply device includes: a circuit board E; an electrolytic capacitor 120 mounted onto the circuit board E; and a guide J disposed adjacent to the electrolytic capacitor 120. The electrolytic capacitor 120 has an explosion-proof valve 121 that opens for spouting inner electrolyte H to the outside in a predetermined case. The guide J is disposed facing the explosion-proof valve 121 being separated away therefrom at least a predetermined distance without being directly attached to the electrolytic capacitor 120 to prevent the spouted electrolyte H from adhering to the circuit board E.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power supply device and an image forming apparatus, and more particularly to a power supply device having an electrolytic capacitor provided with an explosion-proof valve.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a laser printer has used a power supply device that rectifies and smoothes commercial AC power and converts it into DC power. In a switching power supply device as a type of DC power supply device, a rectified and smoothed DC power supply is input to a transformer and switched to obtain a desired output. As a switching power supply system, there are a flyback system, a forward system, a current resonance system, and the like. These switching power supply devices have a rectifier circuit that rectifies the input AC power supply and a smoothing circuit that smoothes the rectified current.

  The smoothing circuit may use an electrolytic capacitor in order to obtain a large capacitance. When an excessive voltage is applied to the electrolytic capacitor, gas is generated from the inside of the capacitor. In order to prevent an increase in pressure inside the capacitor due to gas, the electrolytic capacitor is formed with a notch called an explosion-proof valve. When this explosion-proof valve is activated, a conductive electrolyte is ejected from the inside of the capacitor. If the sprayed electrolyte adheres to the surrounding circuit, the circuit may be affected.

  In order to prevent the sprayed electrolyte from adhering to the peripheral circuit, for example, a configuration in which a nonflammable cap member is disposed around the explosion-proof valve of the electrolytic capacitor is disclosed (for example, see Patent Documents 1 and 2). According to this, even if it is ignited at the time of operation of the explosion-proof valve, the cap member can suffocate the suffocation by making the vicinity of the explosion-proof valve lack of oxygen. Further, a configuration is disclosed in which an overcurrent blocking means is provided between the power input unit and the rectifying element so that the explosion-proof valve does not operate when an overvoltage is applied to the electrolytic capacitor (see, for example, Patent Document 3). .

JP 2002-345247 A JP 2002-345262 A JP 2006-288155 A

  However, in the ones disclosed in Patent Documents 1 and 2, the cap member needs to cover the periphery of the explosion-proof valve while maintaining the operation state of the explosion-proof valve, and it is necessary to attach a relatively large cap member to the electrolytic capacitor. There is. There is a possibility that the space occupied on the circuit board of the electrolytic capacitor including the cap member becomes large, and the degree of freedom in circuit arrangement may be impaired. Moreover, in the thing disclosed by patent document 3, it is necessary to provide an overcurrent interruption | blocking means separately between a power supply input part and a rectifier. According to this configuration, the circuit configuration becomes complicated, which may increase the cost.

  The present invention has been made under such circumstances, and an object of the present invention is to easily and inexpensively realize a configuration in which an electrolyte does not adhere to a peripheral circuit when an explosion-proof valve is operated.

  In order to solve the above problems, the present invention has the following configuration.

  (1) An electrolytic capacitor mounted on a circuit board and an explosion-proof valve that is mounted on the circuit board and opens the valve when a voltage of a predetermined value or more is applied, and ejects an internal electrolyte solution to the outside; An adhesion preventing member that is disposed in the vicinity of the electrolytic capacitor and prevents the ejected electrolyte from adhering to a predetermined position of the circuit board when the electrolyte is ejected from the explosion-proof valve; The adhesion preventing member is not directly attached to the electrolytic capacitor, but is disposed at least a predetermined distance away from the explosion-proof valve.

  (2) An image forming apparatus comprising: an image forming unit that forms an image on a recording material; and the power supply device according to (1).

  According to the present invention, a configuration in which the electrolytic solution does not adhere to the peripheral circuit when the explosion-proof valve is operated can be realized easily and inexpensively.

1 is an overall configuration diagram of a printer according to a first embodiment, and a circuit configuration diagram of a power supply device according to the first embodiment. Partial enlarged view of the smoothing circuit of Example 1, arrangement state diagram near the electrolytic capacitor FIG. 3 is a state diagram in which the power supply device according to the first embodiment is incorporated into the printer, and FIG. Arrangement state diagram in the vicinity of the electrolytic capacitor of Modification 3, State diagram in which the power supply device of Modification 4 is incorporated in the printer Arrangement state diagram of the vicinity of the electrolytic capacitor of the second embodiment, state diagram in which the power supply device of the second embodiment and the fifth modification is incorporated in the printer Arrangement state diagram near the electrolytic capacitor of Example 3, state diagram in which the power supply device is incorporated in the printer Arrangement state diagram in the vicinity of the electrolytic capacitor of Modification 6, State diagram in which the power supply device of Modification 7 is incorporated in the printer

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail by way of examples with reference to the drawings.

[Printer 201]
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1A is an overall configuration diagram of a laser printer 201 as an image forming apparatus according to the first embodiment. Examples of the image forming apparatus include a laser printer, a copying machine, and a facsimile using an electrophotographic system. In the first embodiment, a color type laser printer (hereinafter simply referred to as a printer) capable of executing density correction control for correcting the print density during printing (image formation) and print position correction control for correcting the print position (image formation position). 201). The printer 201 generally includes a paper feeding unit 10, an exposure unit 210, an image forming unit 30, a transfer unit 40, a fixing unit 224, a paper discharge unit 50, a control unit 60, and a power supply device A.

  The paper supply unit 10 is for storing recording paper (recording material) 221 and sending it to the transfer unit 40. The paper feed unit 10 includes a cassette 220 that stores recording paper 221 in a stacked manner, and a paper feed roller 222 that feeds the recording paper 221 one by one from the cassette 220 and conveys the recording paper 221 to the transfer unit 40.

  The exposure unit 210 is for exposing the charged photosensitive drum (image carrier) 215 to form an electrostatic latent image on the surface of the photosensitive drum 215. The exposure unit 210 includes a laser light source 211 as an exposure light source and a rotating polygon mirror 207 for scanning light from the laser light source 211. The light scanned by the rotary polygon mirror 207 forms an image on the surfaces of the plurality of photosensitive drums 215 corresponding to the respective colors via lenses, mirrors, and the like.

  The image forming unit 30 is for forming a toner image on the surface of the photosensitive drum 215 by developing the electrostatic latent image on the surface of the photosensitive drum 215 with toner. In addition to the exposure unit 210 and the photosensitive drum 215, the image forming unit 30 includes a charging unit 216 that charges the photosensitive drum 215 and a developing unit 217 that attaches toner to the surface of the photosensitive drum 215.

  The transfer unit 40 is for transferring the toner image on the surface of the photosensitive drum 215 onto the recording paper 221 via the intermediate transfer belt 202 that is rotationally driven by the driving roller 226. The transfer unit 40 includes an endless belt-like intermediate transfer belt 202, a transfer roller 218, and a secondary transfer unit 223. A toner image for each color is transferred (primary transfer) onto the intermediate transfer belt 202 by the photosensitive drum 215 and the transfer roller 218. The toner image primarily transferred onto the intermediate transfer belt 202 is transferred (secondary transfer) onto the recording paper 221 by the secondary transfer unit 223 and the driven roller 227.

  The fixing unit 224 fixes the toner image on the recording paper 221 by heating and pressurizing the toner image secondarily transferred onto the recording paper 221. The fixing unit 224 includes a fixing roller for pressing the recording paper 221 sent from the secondary transfer unit 223 and a heater for heating the recording paper 221.

  The paper discharge unit 50 is for discharging the fixed recording paper 221 from the inside of the printer 201 to the outside. The paper discharge unit 50 includes a paper discharge roller 51 disposed on the downstream side of the fixing unit 224 in the conveyance direction of the recording paper 221 and a placement unit 52 on which the discharged recording paper 221 is stacked and placed.

  The control unit 60 controls the operation of the image forming unit 30 of the printer 201, and includes an image generation unit 204 and an image control unit 206. The image control unit 206 has a CPU 209 inside and is connected to the image generation unit 204. The CPU 209 controls the operation of the image forming unit 30 while using the RAM 209b as a work area according to various programs stored in the ROM 209a. The image generation unit 204 generates a video signal 205 for image formation based on the image data 203 from the external device, and transmits it to the image control unit 206. The image control unit 206 is connected to the image forming unit 30 and causes the image forming unit 30 to perform image formation based on the video signal 205.

  The power supply device A is for supplying power to each unit including the control unit 60 and the image forming unit 30 in the printer 201. The power supply device A is provided in the printer 201 and is directly or indirectly connected to each unit including the control unit 60 and the image forming unit 30. Hereinafter, details of the power supply device A will be described.

[Power supply device A]
Example 1
FIG. 1B is a circuit configuration diagram of the power supply device A according to the first embodiment. The power supply device A includes a circuit unit (primary side circuit unit) C and a circuit unit (secondary side circuit unit) D. The circuit unit C and the circuit unit D are arranged on a circuit board E (see FIG. 2 and the like). The circuit board E is usually constituted by a single printed board, but may be constituted by a plurality of printed boards whose mounting surfaces are parallel.

  The circuit unit C includes an inlet 101, a fuse 102, a filter circuit 103, a rectifier circuit (primary side rectifier circuit) 104, a smoothing circuit 105, an FET (switching FET) 107, and a control circuit 108. The circuit unit D includes a rectifier circuit (secondary rectifier circuit) 109 and a detection circuit 111. The power supply device A also has a transformer 106. The primary coil 106a of the transformer 106 belongs to the circuit unit C, and the secondary coil 106b belongs to the circuit unit D. However, the transformer 106 is included in the circuit unit C as a whole.

  A commercial AC power supply B is connected to the power supply device A, and power is supplied via the inlet 101. The electric power supplied to the power supply device A reaches the rectifier circuit 104 via the fuse 102 and the filter circuit 103. The rectifier circuit 104 is a diode bridge circuit including four diodes, for example. The AC input current, which is a sine waveform of the commercial AC power supply B, is rectified by the rectifier circuit 104 and becomes a pulsating waveform. An input current that exhibits a pulsating waveform is smoothed by the smoothing circuit 105.

  The smoothed current value of the input current is close to the peak current value in the sinusoidal waveform of the AC input current. The smoothed input current is input to the transformer 106 from the plus terminal 104a and is fed back to the minus terminal 104b via the FET 107. The on / off timing of the FET 107 is controlled by the control circuit 108. The power supply power of the control circuit 108 is generated by the transformer 106.

  A rectifier circuit 109 is connected to the secondary side coil 106 b of the transformer 106. The power converted by the transformer 106 reaches the rectifier circuit 109, rectified and smoothed to a predetermined current value by the rectifier circuit 109, and output to the load 110 outside the power supply device A. The output side terminal of the rectifier circuit 109 is connected to the detection circuit 111, and the output current value of the rectifier circuit 109 is also input to the detection circuit 111. The value detected by the detection circuit 111 (the output current value of the rectifier circuit 109) is input to the control circuit 108. In order to ensure insulation between the detection circuit 111 side (secondary side circuit part D side) and the control circuit 108 side (primary side circuit part C side), for example, the detection circuit 111 and The control circuit 108 is connected. Based on the detection value in the detection circuit 111 input to the control circuit 108, the control circuit 108 determines the on / off timing of the FET 107.

[Configuration around electrolytic capacitor 120]
FIG. 2A is a partially enlarged view of the smoothing circuit 105 and is a view seen from the side of the circuit board E. FIG. In the smoothing circuit 105, electronic components including the electrolytic capacitor 120 are mounted on the circuit board E. An explosion-proof valve 121 is provided on the upper surface (surface opposite to the circuit board E) of the electrolytic capacitor 120. The explosion-proof valve 121 is opened when an excessive voltage is applied to the electrolytic capacitor 120 (when a voltage higher than a predetermined value is applied), and the electrolytic solution H inside the electrolytic capacitor 120 is ejected to the outside. It is. FIG. 2A shows a state in which the explosion-proof valve 121 is opened and the electrolytic solution H is ejected.

  As shown in FIG. 2B, the smoothing circuit 105 has a guide (deflection member) J. The guide J is used to change the ejection direction of the ejected electrolyte H when the electrolyte H is ejected from the explosion-proof valve 121 and prevent the electrolyte H from adhering to a predetermined position of the circuit board E. It is. The predetermined position may typically be the circuit unit C in particular, but is not limited to the circuit unit C, and depending on the design convenience, mounting positions and wiring patterns of various electronic components on the circuit board E The location of The guide J may be directly mounted on the circuit board E, or may be arranged via components attached on the circuit board E. Further, instead of the circuit board E, it may be attached to a member around the circuit board E (for example, a board case (not shown)). The guide J is not directly attached to the electrolytic capacitor 120. In the first embodiment, the guide J is a flat plate member as shown in FIG. The material of the guide J may be a metal material or a resin material such as plastic.

  The guide J has a surface with the explosion-proof valve 121 so that the electrolyte H ejected from the explosion-proof valve 121 of the electrolytic capacitor 120 reflects in a direction parallel to the circuit board E or in a direction away from the circuit board E ( The upper surface is opposed to the upper surface. The angle at which the electrolyte H is ejected from the explosion-proof valve 121 is α (see FIG. 2A). The ejection angle α is a diffusion angle when the electrolytic solution H is ejected while diffusing from the upper surface of the electrolytic capacitor 120 (the surface where the explosion-proof valve 121 is disposed), and the upper surface and the diffusion direction of the electrolytic solution H form. Is an angle. As shown in FIG. 2A, when the electrolytic capacitor 120 is mounted upright on the circuit board E, the ejection angle α is an angle formed by the mounting surface of the circuit board E and the diffusion direction of the electrolyte H. It almost agrees.

  An installation angle of the guide J is β (see FIG. 2B). The installation angle (tilt angle) β is an angle formed by the upper surface of the electrolytic capacitor 120 and the extending direction of the surface of the guide J. In the first embodiment, since the electrolytic capacitor 120 is mounted upright on the circuit board E, the installation angle β is substantially the same as the angle formed by the mounting surface of the circuit board E and the extending direction of the surface of the guide J. To do. In order to reflect the sprayed electrolyte H in a direction parallel to the mounting surface of the circuit board E, or to reflect it in a direction away from the mounting surface of the circuit board E, the electrolyte H is regularly reflected at the position Z on the guide J. The guides J are arranged so that the reflection direction of is parallel to the mounting surface of the circuit board E. In the first embodiment, the electrolytic capacitor 120 is mounted in the vicinity of the boundary between the circuit part C and the circuit part D, and the guide J opens at an installation angle β that opens from the circuit part C side to the circuit part D side. Has been placed.

FIG. 2B shows a state in which the reflection direction of the electrolytic solution H that is regularly reflected at the position Z on the guide J is parallel to the mounting surface of the circuit board E. The position Z is a position on the guide J where the ejected electrolyte H reaches the position closest to the guide J. In other words, it is a position where the ejected electrolyte H enters the guide J at the smallest incident angle. In Example 1, the relationship of the following formula | equation is materialized between the ejection angle (alpha) and the installation angle (beta).
β = (180 ° −α) / 2

  In the case of the ejection angle α, the guide J is arranged at an angle equal to or larger than the installation angle β, so that the reflection direction when the electrolyte H is reflected by the guide J is a direction parallel to the surface of the circuit board E, or The direction can be away from the surface of the circuit board E.

  When the explosion angle α when the explosion-proof valve 121 of the electrolytic capacitor 120 was operated under the predetermined condition, the ejection angle α was measured to be 70 ° to 75 °. For example, when the ejection angle α = 70 °, the guide J installation angle β = 55 ° from the above equation, and when the ejection angle α = 75 °, the guide J installation angle β = 52.5 °. By setting the installation angle β of the guide J according to the ejection angle α of the electrolytic solution H from the explosion-proof valve 121, it is possible to prevent the electrolytic solution H from adhering to the circuit board E, particularly to the circuit portion C. it can. As shown in FIG. 2B, a predetermined distance d is secured between the lower end J1 of the guide J and the upper surface of the electrolytic capacitor 120 (the surface on which the explosion-proof valve 121 is disposed). The distance d is a distance ensured so that the guide J does not affect the operation of the explosion-proof valve 121, and is about 3 mm, for example.

  FIG. 2C is a diagram illustrating an arrangement state in the vicinity of the electrolytic capacitor 120 on the circuit board E. FIG. 2C shows a side view of the circuit board E as seen from the side. The rectifier circuit 104 and the FET 107 are arranged on the circuit part C side, and the transformer 106 is arranged so as to straddle the circuit parts C and D. The electrolytic capacitor 120 is disposed on the circuit unit C side and at a position close to the boundary between the circuit unit C and the circuit unit D. A guide J is disposed opposite to the upper surface of the electrolytic capacitor 120.

  When an overvoltage is applied to the electrolytic capacitor 120 and the pressure inside the electrolytic capacitor 120 increases and the explosion-proof valve 121 is activated, the electrolyte H is ejected from the explosion-proof valve 121. Without the guide J, the sprayed electrolyte H is scattered around and adheres to the electronic component on the circuit part C side. However, in the first embodiment, the ejected electrolyte H is reflected by the guide J and deflected toward the circuit part D side. The reflection direction is a direction parallel to the circuit board E or a direction away from the circuit board E. Furthermore, the arrangement position of the electrolytic capacitor 120 is near the boundary between the circuit part C and the circuit part D. Therefore, the sprayed electrolyte H is prevented from adhering to the electronic component on the circuit part C side.

[Arrangement of the power supply device A in the printer 201]
FIG. 3A is a diagram illustrating a state in which the power supply device A is incorporated in the printer 201. In the first embodiment, the mounting surface of the circuit board E is arranged in a substantially vertical direction when the printer 201 is installed. The extension direction of the electrolytic capacitor 120 mounted on the circuit board E is a substantially horizontal direction, and the upper surface (the surface on which the explosion-proof valve 121 is disposed) is a substantially vertical direction. Therefore, the central axis in the direction of ejection of the electrolyte H ejected from the explosion-proof valve 121 is substantially horizontal. FIG. 3A shows the three-axis directions of the printer 201 in the installed state by XYZ. Also in other drawings, the respective axial directions of the power supply device A arranged in the printer 201 are shown corresponding to the XYZ axes in FIG.

  3B is a cross-sectional view of the power supply device A shown in FIG. 3A cut along a plane parallel to the side surface 201a and passing through the approximate center of the electrolytic capacitor 120. FIG. The cut surface P is indicated by a thick two-dot chain line in FIG. The circuit board E on which the electrolytic capacitor 120 is mounted is attached to the chassis F with screws K and is grounded to the chassis F. The chassis F is fixed directly to the casing of the printer 201 or via the case of the power supply device A (shown by a broken line in FIG. 3B), and is grounded to the casing of the printer 201.

  By arranging the mounting surface of the circuit board E so as to be substantially vertical in this way, even if the sprayed electrolyte H remains attached to the guide J, the electrolyte H is more toward the circuit board E. It is possible to prevent the flow (in particular toward the circuit part C). When the electrolyte H attached to the guide J flows, it flows to the vertically lower side without the circuit board E. As described above, according to the first embodiment, when the explosion-proof valve 121 is operated, a configuration in which the electrolytic solution does not adhere to the peripheral circuit, particularly the circuit part C side, can be realized easily and inexpensively.

(Modification 1)
In the first embodiment, the direction in which the installation angle β of the guide J opens is the circuit portion D side. However, it is also effective to set the direction in which the installation angle β is opened downward (that is, the side without the circuit board E or the electronic component) as shown in FIG. The electrolytic solution H ejected from the explosion-proof valve 121 and reflected by the guide J can be deflected in a direction where there is no circuit board E or electronic component. FIG. 3C is a cross-sectional view of the power supply device A according to the modified example 1, and is a view taken along the same cutting plane P as in FIG. According to the first modification, the electrolyte H ejected from the explosion-proof valve 121 can be changed in a direction where there is no circuit board E or electronic component.

(Modification 2)
In the first embodiment, the configuration in which the mounting surface of the circuit board E is in a substantially vertical direction when the printer 201 is installed has been described. However, the mounting surface of the circuit board E is in a substantially horizontal direction when the printer 201 is installed. There may be. In this case, the extending direction of the electrolytic capacitor 120 is a substantially vertical direction, and the upper surface of the electrolytic capacitor 120 on which the explosion-proof valve 121 is disposed is a substantially horizontal direction. If the guide J is disposed with respect to the electrolytic capacitor 120 in the same positional relationship as in the first embodiment, the electrolytic solution H ejected from the explosion-proof valve 121 is reflected by the guide J and deflected toward the circuit portion D side. The The electrolytic solution H is prevented from adhering to the electronic component on the circuit part C side. According to the modified example 2, even when the mounting surface of the circuit board E is in a substantially horizontal direction, it is possible to prevent the electrolyte H from adhering to the circuit portion C.

(Modification 3)
In the first embodiment, the case where the guide J is a flat member has been described. However, as illustrated in FIG. 4A, a guide J2 having a curved surface that gradually changes the ejection direction of the electrolyte H may be used. . As in the first embodiment, the circuit board E according to the third modification has a mounting surface in a substantially vertical direction when the printer 201 is installed. The material of the guide J2 and the attachment method to the circuit board E etc. may be the same as the guide J of the first embodiment. For example, as shown in FIG. 4A, the guide J2 has an arcuate section, and its radius of curvature is R. Further, the lower end portion J1 of the guide J2 is arranged at a distance d from the upper surface of the electrolytic capacitor 120, as in the first embodiment.

  The arcuate section of the guide J2 is disposed such that the center of the arc is closer to the circuit part C side than the electrolytic capacitor 120, and the electrolytic solution H ejected from the explosion-proof valve 121 and reflected by the guide J2 is on the circuit part D side. To be deflected. The reflection direction is preferably parallel to the circuit board E or away from the circuit board E. However, if the electrolytic solution H does not adhere to the circuit part C, the reflection direction is the direction toward the circuit part D. May be. The arrangement relationship of the guide J2 with respect to the electrolytic capacitor 120, the numerical value of the radius of curvature R of the arcuate section, and the numerical value of the distance d are the mounting position of the electrolytic capacitor 120 on the circuit board E, and the ejection of the electrolytic solution H from the explosion-proof valve 121. It is set as appropriate according to the angle α and the like. In addition, the curved surface which the guide J2 has is not restricted to the case where it is circular arc cross-section, A cross-sectional elliptic arc shape, a cross-sectional parabola shape, and another curved surface are selected suitably. According to the modification 3, it can prevent that the electrolyte solution H ejected from the explosion-proof valve 121 adheres to the circuit part C side.

(Modification 4)
In the third modification, the arc center of the guide J2 is arranged so as to be closer to the circuit part C than the electrolytic capacitor 120. In the modified example 4, it is also effective that the center of the arc of the guide J2 is downward (that is, the side without the circuit board E or the electronic component) as shown in FIG. 4B. The electrolytic solution H ejected from the explosion-proof valve 121 and reflected by the guide J2 can be deflected in a direction where there is no circuit board E or electronic component. 4B is a cross-sectional view of the power supply device A in the case where the power supply device A according to the modified example 3 is arranged inside the printer 201, and is cut along a cutting plane P similar to that in FIG. FIG. According to the fourth modification, the electrolyte H ejected from the explosion-proof valve 121 can be changed in a direction where there is no circuit board E or electronic component.

(Example 2)
FIG. 5A is a diagram illustrating an arrangement state in the vicinity of the electrolytic capacitor 120 on the circuit board E in the power supply device A according to the second embodiment. Fig.5 (a) has shown the side view which looked at the circuit board E from the side surface similarly to FIG.2 (c) and FIG.4 (a). In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment, a guide J3 as a deflection member is disposed near the upper surface of the electrolytic capacitor 120. The guide J3 is a passage-like member in which the inlet end portion J4 and the outlet end portion J5 are communicated by a hollow passage whose periphery is covered. The inlet end J4 of the guide J3 faces the upper surface where the explosion-proof valve 121 of the electrolytic capacitor 120 is disposed, and is spaced apart by a predetermined distance d. The distance d and the size of the inlet end J4 are set in consideration of the ejection angle α so that most of the electrolyte H ejected when the explosion-proof valve 121 is operated enters the hollow passage from the inlet end J4. Is done. About the material of the guide J3 and the attachment method to the circuit board E etc., you may be the same as that of the guide J of Example 1. FIG.

  The exit end J5 of the guide J3 is directed to the circuit part D side. The position of the outlet end portion J5 is preferably near the boundary between the circuit portion C and the circuit portion D, and more preferably penetrates the circuit portion D side beyond the boundary. The hollow passage that connects the inlet end portion J4 and the outlet end portion J5 is covered with the periphery, so that the electrolyte H in the hollow passage does not leak to the outside in the middle of the passage. The direction in which the outlet end portion J5 faces, that is, the extending direction of the hollow passage in the vicinity of the outlet end portion J5 is preferably parallel to the circuit board E and more preferably away from the circuit board E.

  FIG. 5B shows a state where the power supply device A according to the second embodiment is incorporated in the printer 201. FIG. 5B is a cross-sectional view partially cut along a cutting plane P passing through the approximate center of the electrolytic capacitor 120, as in FIG. As shown in FIG. 5B, the power supply device A according to the second embodiment is arranged inside the printer 201 so that the mounting surface of the circuit board E is in a substantially vertical direction. The dimension of the inlet end J4 of the guide J3 is set larger than the dimension of the upper surface of the electrolytic capacitor 120 (the surface on which the explosion-proof valve 121 is disposed). Almost all of the electrolyte H ejected from the explosion-proof valve 121 is introduced into the hollow passage of the guide J3 through the inlet end J4. As described above, according to the second embodiment, when the explosion-proof valve 121 is operated, a configuration in which the electrolytic solution does not adhere to the peripheral circuit, particularly the circuit unit C side, can be realized easily and inexpensively.

(Modification 5)
In the second embodiment, the example in which the outlet end portion J5 of the guide J3 is directed to the circuit portion D side has been described. However, as shown in FIG. 5C, it is also effective to dispose the outlet end portion J5 downward (that is, the side without the circuit board E or the electronic component). The electrolyte H ejected from the explosion-proof valve 121 and introduced into the hollow passage from the inlet end J4 can be deflected in a direction where there is no circuit board E or electronic component. FIG. 5C is a cross-sectional view of the power supply device A according to the modified example 5, and is a view obtained by partially cutting along the same cutting plane P as in FIG. According to the modified example 5, the electrolyte H ejected from the explosion-proof valve 121 can be changed in a direction where there is no circuit board E or electronic components.

Example 3
FIG. 6A is a diagram illustrating an arrangement state in the vicinity of the electrolytic capacitor 120 on the circuit board E in the power supply device A according to the third embodiment. FIG. 6A shows a side view of the circuit board E viewed from the side, as in FIGS. 2C and 4A. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the third embodiment, a cover (shielding member) M is disposed so as to cover the circuit unit C. The cover M is for preventing the electrolytic solution H from adhering to a predetermined position of the circuit board E when the electrolytic solution H is ejected from the explosion-proof valve 121. The cover M is disposed on the mounting surface side of the circuit board E, and an opening M1 that exposes the upper surface of the electrolytic capacitor 120 having the explosion-proof valve 121 is formed. When the circuit board E is viewed from the mounting surface side, the electronic components arranged on the circuit part C side are covered with the cover M except for the electrolytic capacitor 120. Only the upper surface of the electrolytic capacitor 120 is exposed from the opening M1. As a result, the cover M and the explosion-proof valve 121 are separated by a predetermined distance, and the cover M does not affect the operation of the explosion-proof valve 121. About the material of the cover M, the attachment method to the circuit board E etc., you may be the same as that of the guide J of Example 1. FIG.

  By covering the electronic component on the circuit unit C side with the cover M, the electrolytic solution H adheres to the electronic component on the circuit unit C side even when the explosion-proof valve 121 is activated and the electrolytic solution H is ejected. Can be prevented. Even when the sprayed electrolyte H collides with other parts or cases in the power supply device A and bounces back toward the circuit board E side, the cover M prevents the electrolyte H from adhering to the circuit part C side. The Further, when the cover M covers the entire circuit board E on the circuit part C side, even when the electrolyte H attached to the cover M flows down, the electrolyte H adheres to the circuit board E on the circuit part C side. Is prevented. As shown in FIG. 6B, the power supply device A is arranged in the printer 201 so that the mounting surface of the circuit board E is in a substantially vertical direction. As a result, even when the electrolytic solution H ejected and collided with other components and bounced adheres to the cover M, the electrolytic solution H can flow down in the direction without the circuit board E or electronic components. it can. As described above, according to the third embodiment, when the explosion-proof valve 121 is operated, a configuration in which the electrolytic solution does not adhere to the peripheral circuit, particularly the circuit part C side, can be realized easily and inexpensively.

(Modification 6)
In the sixth modification, the cover M described in the third embodiment and the guide J described in the first embodiment are used in combination. FIG. 7A is a diagram illustrating an arrangement state in the vicinity of the electrolytic capacitor 120 on the circuit board E in the power supply device A of the sixth modification. Fig.7 (a) has shown the side view which looked at the circuit board E from the side surface similarly to FIG.2 (c) and FIG.4 (a). The cover M prevents the electrolytic solution H ejected from the explosion-proof valve 121 from adhering to the electronic component or the like on the circuit part C side. Furthermore, since the guide J is disposed, the sprayed electrolyte H is prevented from splashing from other parts in the power supply device A and adhering to the electrolytic capacitor 120. In the guide J of Modification 6, the direction in which the installation angle β opens is the circuit part D side.

  The material of the guide J and the attachment method to the circuit board E etc. may be the same as in the first embodiment. About the material of the cover M, the attachment method to the circuit board E etc., you may be the same as that of Example 3. FIG. In the modified example 6, since the circuit part C side is covered with the cover M, the reflection direction of the electrolytic solution H reflected by the guide J has a higher degree of freedom than in the case of the first embodiment. That is, in Modification 6, even if the guide J is arranged at an installation angle β such that the electrolytic solution H reflected by the guide J is reflected in a direction close to the mounting surface of the circuit board E, the electrolytic solution is applied by the cover M. H is prevented from adhering to an electronic component or the like on the circuit part C side. According to the modification 6, it can prevent that the electrolyte solution H which ejected from the explosion-proof valve 121 adheres to the circuit part C side. In addition, it is possible to prevent the electrolytic solution H ejected from the explosion-proof valve 121 from adhering to the electrolytic capacitor 120.

(Modification 7)
In the modified example 6, the direction in which the installation angle β of the guide J opens is the circuit part D side. However, it is also effective to set the direction in which the installation angle β is opened downward as shown in FIG. 7B (that is, the side without the circuit board E or electronic components). FIG. 7B shows a state in which the power supply device A according to the modified example 7 is incorporated in the printer 201. FIG. 7B shows a state in which the power supply device A of the modified example 7 is arranged in the printer 201 so that the mounting surface of the circuit board E is in a substantially vertical direction, as in FIG. FIG. 12 is a partial cross-sectional view partially cut by a cutting plane P passing through the approximate center of 120. In this modified example 7, since the installation angle β of the guide J is opened downward, the electrolyte H that is ejected from the explosion-proof valve 121 and reflected by the guide J is directed in the direction in which there is no circuit board E or electronic component (downward ).

  According to the modified example 7, it can prevent that the electrolyte solution H which ejected from the explosion-proof valve 121 adheres to the circuit part C side. In addition, the electrolyte H ejected from the explosion-proof valve 121 can be changed in a direction where there is no circuit board E or electronic component. The guides J, J2, and J3 that function as deflection members and the cover M that functions as a shielding member are collectively referred to as an adhesion preventing member for preventing the electrolyte H from adhering to the circuit board E, particularly the circuit portion C. Can be a concept.

d Distance E Circuit board H Electrolyte J, J2, J3 Guide (deflection member, adhesion prevention member)
M cover (shielding member, adhesion prevention member)
120 Electrolytic capacitor 121 Explosion-proof valve

Claims (10)

A circuit board;
An electrolytic capacitor that is mounted on the circuit board and has an explosion-proof valve that opens when a voltage of a predetermined value or more is applied, and ejects the internal electrolyte to the outside,
An adhesion preventing member that is disposed in the vicinity of the electrolytic capacitor and prevents the ejected electrolyte from adhering to a predetermined position of the circuit board when the electrolyte is ejected from the explosion-proof valve;
The power supply apparatus according to claim 1, wherein the adhesion preventing member is not directly attached to the electrolytic capacitor, but is disposed at least a predetermined distance away from the explosion-proof valve. A primary side circuit part and a secondary side circuit part are formed on the circuit board,
The primary side circuit unit includes at least a primary side rectifier circuit that rectifies current from a commercial AC power supply, and a smoothing circuit that includes the electrolytic capacitor and smoothes the current after rectified by the primary side rectifier circuit. And
The secondary side circuit unit smoothes the current after being smoothed by the smoothing circuit and voltage-converted by the transformer, and the current value after being rectified by the secondary side rectification circuit. A detection circuit for detecting at least,
The power supply apparatus according to claim 1, wherein the adhesion preventing member prevents the sprayed electrolyte from adhering to at least the primary circuit section.   The power supply apparatus according to claim 2, wherein the adhesion preventing member is a deflecting member that deflects the ejected electrolytic solution in a direction away from the primary circuit section.   The power supply apparatus according to claim 3, wherein the deflecting member is a flat plate member that is inclined with respect to a surface of the electrolytic capacitor on which the explosion-proof valve is disposed.   The inclination angle of the deflection member is (180−α) when the angle formed by the most diffusing electrolyte out of the explosion-proof valve and the surface on which the explosion-proof valve is disposed is defined as the ejection angle α. The power supply device according to claim 4, wherein the power supply device has a value of / 2 or more.   5. The deflecting member, wherein the deflecting member and the surface on which the explosion-proof valve is disposed are disposed so as to be inclined toward the secondary circuit unit. 5. The power supply device according to 5.   The power supply apparatus according to claim 3, wherein the deflecting member has a curved surface that gradually changes a direction of the ejected electrolyte.   The power supply apparatus according to claim 2, wherein the adhesion preventing member is a shielding member that covers the primary side circuit portion formed on the circuit board except for the electrolytic capacitor. An image forming unit for forming an image on a recording material;
The power supply device according to any one of claims 1 to 8,
An image forming apparatus comprising: In the installed state,
The mounting surface of the circuit board is substantially vertical,
The extension direction of the electrolytic capacitor mounted on the circuit board is a substantially horizontal direction,
The upper surface of the electrolytic capacitor is substantially vertical, and
The image forming apparatus according to claim 9, wherein the explosion-proof valve is disposed on the upper surface.

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