Image forming apparatus

Abstract

The present invention relates to an image forming apparatus including an image forming unit and a power supply device. The power supply device includes a circuit board disposed to cross a horizontal plane. The power supply device includes an electrolytic capacitor that protrudes from a mounting surface of the circuit board in a first direction, an electrical element, and a plate-like member disposed between the electrolytic capacitor and the electrical element in a vertical direction and including a first surface extending in a second direction that crosses the vertical direction. The plate-like member includes a cutout or hole, and at least a portion of an area forming the cutout or hole is located further from the mounting surface of the circuit board in the first direction than a location of the electrical element.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus, the image forming apparatus including a power supply device, the power supply device including an electrolytic capacitor equipped with an explosion-proof valve. Background Technology

[0002] Power supply devices that convert commercial AC power into DC power by rectifying and smoothing it have been used in image forming equipment such as laser beam printers. Such power supply devices obtain the desired output power by inputting the rectified and smoothed DC power into a transformer and switching the input power, and include a rectifier circuit for rectifying the input AC power and a smoothing circuit for smoothing the rectified current.

[0003] Smoothing circuits require large-capacity capacitors, so electrolytic capacitors are sometimes used. Applying excessive voltage to an electrolytic capacitor can cause gas to be generated inside. To prevent pressure buildup due to gas, electrolytic capacitors include a cutout called a vent valve (also known as a "pressure valve"). When the vent valve is activated, gas containing electrolyte is ejected from the inside of the capacitor. The ejected electrolyte is a conductive liquid, so if it adheres to nearby circuitry, it can affect the circuit. Specifically, if electrolyte adheres to the primary circuitry, a short circuit may occur, potentially leading to a large current flow.

[0004] In view of this problem, Japanese Patent No. 6598511 discusses a deflection plate that is disposed opposite to the explosion-proof valve of an electrolytic capacitor, such that when the explosion-proof valve is open, the sprayed electrolyte is guided by the deflection plate to a circuit area that will not be affected by electrolyte adhesion. Specifically, the sprayed electrolyte is guided by the deflection plate to the secondary circuit without adhering to the primary circuit.

[0005] According to Japanese Patent No. 6598511, a circuit board is built into an image forming apparatus such that the mounting surface of the circuit board is approximately vertical. Furthermore, an electrolytic capacitor mounted on the circuit board extends approximately horizontally. In this aforementioned configuration, when the explosion-proof valve is open, the electrolyte ejected in a approximately horizontal direction is guided to the secondary circuit by a deflector plate facing the explosion-proof valve, but some electrolyte still flows to the area below the electrolytic capacitor in the vertical direction.

[0006] In the configuration discussed in Japanese Patent No. 6598511, the aforementioned short-circuit problem does not occur because a primary circuit is not provided below the electrolytic capacitor in the vertical direction. However, in order to achieve more flexible circuit layout, even in a configuration where electrical components are provided below the electrolytic capacitor in the vertical direction, it is desirable to reduce the impact of electrolyte ejected when the explosion-proof valve is opened. Summary of the Invention

[0007] The present invention relates to preventing electrolyte ejected from an electrolytic capacitor from adhering to electrical components disposed below the electrolytic capacitor in the vertical direction.

[0008] According to one aspect of the invention, an image forming apparatus includes an image forming unit configured to form an image on a recording material, and a power supply device configured to supply power to the image forming unit, the power supply device including a circuit board disposed intersecting a horizontal plane. The power supply device includes: an electrolytic capacitor including an explosion-proof valve configured to open and eject internal electrolyte upon application of a voltage higher than or equal to a predetermined value, the electrolytic capacitor protruding from a mounting surface of the circuit board in a first direction; an electrical component located vertically below the electrolytic capacitor, the electrical component being exposed from the mounting surface; and a plate-like member disposed vertically between the electrolytic capacitor and the electrical component, the plate-like member including a first surface extending in a second direction intersecting the vertical direction when viewed in a direction perpendicular to the mounting surface of the circuit board. The plate-like member includes a cut or hole, and at least a portion of the region forming the cut or hole is located further away from the mounting surface of the circuit board in the first direction than the location of the electrical component.

[0009] According to another aspect of the present invention, an image forming apparatus includes an image forming unit configured to form an image on a recording material, and a power supply device configured to supply power to the image forming unit, the power supply device including a circuit board disposed intersecting a horizontal plane. The power supply device includes: an electrolytic capacitor including an explosion-proof valve configured to open and eject internal electrolyte upon application of a voltage higher than or equal to a predetermined value, the electrolytic capacitor protruding from a mounting surface of the circuit board in a first direction; an electrical component located vertically below the electrolytic capacitor, the electrical component being exposed from the mounting surface; and a plate-like member disposed vertically between the electrolytic capacitor and the electrical component, the plate-like member including a first surface extending in a second direction intersecting the vertical direction when viewed in a direction perpendicular to the mounting surface of the circuit board. When viewed along the mounting surface of the circuit board, the plate-like member protrudes beyond the distal portion of the electrolytic capacitor in the first direction, and the plate-like member is inclined relative to the mounting surface such that, when viewed along the mounting surface of the circuit board, the position of the end portion of the plate-like member closest to the circuit board in the first direction is higher in the vertical direction than the position of the other end portion of the plate-like member on the side opposite to the circuit board.

[0010] Further features of the invention will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0011] Figure 1 This is a general schematic diagram showing a laser beam printer.

[0012] Figure 2 This is a circuit block diagram showing the power supply device.

[0013] Figure 3 This is a view showing the layout and configuration of the power supply unit in a laser beam printer.

[0014] Figure 4 This is a perspective view showing a power supply device including a heat sink with cutouts according to a first exemplary embodiment.

[0015] Figure 5 This is a cross-sectional view of the power supply device, in which electrolyte falls from point C.

[0016] Figure 6 This is a cross-sectional view of the power supply device, in which electrolyte falls from point B.

[0017] Figure 7 This is a front view of the power supply unit, with the heat sink tilted toward point B.

[0018] Figure 8 This is a front view of the power supply unit, with the heat sink tilted toward point A.

[0019] Figure 9 This is a perspective view showing a power supply device including a heat sink with a new cutout, according to a first exemplary embodiment.

[0020] Figure 10 This is a front view of the power supply unit, with the heat sink tilted toward point A.

[0021] Figure 11 This is a cross-sectional view of the power supply device, in which electrolyte falls from point E.

[0022] Figure 12 This is a perspective view showing a power supply device including a heat sink with holes according to a first exemplary embodiment.

[0023] Figure 13 This is a cross-sectional view of a power supply device including a guide plate according to a second exemplary embodiment. Detailed Implementation

[0024] A power supply device 100 applied to an image forming apparatus according to a first exemplary embodiment of the present invention will now be described. Figure 1This is an overall view showing a laser beam printer 700 (hereinafter referred to as "printer 700") as an example of an image forming apparatus. Printer 700 includes a photosensitive drum 701, a charging unit 702, and a developing unit 703. The photosensitive drum 701 is an image-carrying member on which an electrostatic latent image is to be formed. The charging unit 702 uniformly charges the photosensitive drum 701. The developing unit 703 develops the electrostatic latent image formed on the photosensitive drum 701 using toner. The toner image developed on the photosensitive drum 701 is transferred at a transfer section 705 to a sheet of recording material fed from a cartridge 704. The toner image transferred to the sheet is then fixed by a fixing unit 706 heated by a heater 117. The sheet with the fixed toner image is discharged into a sheet discharge tray 707. Printer 700 includes a power supply unit 100 that supplies power to a drive unit such as a motor and to a control unit 500. The control unit 500 controls, for example, the image forming operation, sheet transport, and the temperature of the heater 117, as described above.

[0025] Figure 2 This is a circuit block diagram illustrating a power supply device 100 according to a first exemplary embodiment. A flyback switching power supply is used as an example for description. An AC voltage Vac is supplied to the power supply device 100 from a commercial power supply 101. The AC voltage Vac supplied to the power supply device 100 is supplied to a diode bridge 104 via a fuse 102 and a filter circuit 103. With the AC voltage Vac rectified by the diode bridge 104, a pulsating current waveform with one side positive is obtained. Through the action of a primary electrolytic capacitor 105, the voltage with the pulsating current waveform is smoothed to approximately DC. The voltage applied across the primary electrolytic capacitor 105 is referred to as "voltage Vdc". The potential at the positive terminal of the primary electrolytic capacitor 105 is referred to as "potential DCH", and the potential at the negative terminal of the primary electrolytic capacitor 105 is referred to as "potential DCL".

[0026] The smoothed voltage Vdc is input to the primary winding Np of transformer 108 and fed back to the commercial power supply 101 via the negative terminal of primary electrolytic capacitor 105 and diode bridge 104 through field-effect transistor (FET) 107. The ON / OFF timing of FET 107 is controlled by switch control unit 106. Before switching operation begins, switch control unit 106 draws operating power from terminal ST, and after switching operation begins, switch control unit 106 draws operating power from the voltage between terminals VB and VS (generated from the auxiliary winding Nb of transformer 108). Terminal VS of switch control unit 106 is connected to potential DCL.

[0027] A rectifier unit 151 is connected to the secondary winding Ns of a transformer 108. The power converted to voltage by the transformer 108 is fed to the rectifier unit 151, and the rectifier unit 151 rectifies and smooths the fed voltage to obtain a DC voltage Vout. The DC voltage Vout is output to a load 152 external to the power supply unit 100. The load 152 includes, for example... Figure 1 The control unit 500 shown includes a central processing unit (CPU) (not shown) and a drive unit such as a motor. A DC voltage Vout is connected to a voltage feedback unit 150, and the voltage feedback unit 150 outputs information indicating whether the DC voltage Vout is a predetermined voltage. Specifically, the voltage feedback unit 150 outputs a voltage as an electrical signal between terminals FB and VS of the switch control unit 106. The voltage feedback unit 150 includes primary and secondary circuits that are insulated from each other, and elements such as optocouplers transmit the electrical signal from the secondary circuit to the primary circuit. The switch control unit 106 determines the ON / OFF timing of the FET 107 based on the voltage value between terminals FB and VS and controls the output voltage Vout to a predetermined voltage value.

[0028] Now refer to Figure 3 Describe the layout of the power supply unit 100 in printer 700. Figure 3 In this context, the height direction (opposite to the vertical direction) of the printer 700 placed on a horizontal surface is defined as the Z direction. The direction intersects the Z direction and is parallel to the photosensitive drum 701. Figure 1 The direction of the rotation axis (main scan direction) shown is defined as the X direction. The direction intersecting the X and Z directions is defined as the Y direction. Ideally, the X, Y, and Z directions intersect each other perpendicularly. The XYZ directions also apply to subsequent figures.

[0029] like Figure 3 As shown, printer 700 includes a power supply housing 200. The power supply housing 200 is a box-shaped member indicated by dashed lines and includes a power supply unit 100. The power supply unit 100 includes a circuit board 201 indicated by a single-dotted line and a primary electrolytic capacitor 105 mounted on the circuit board 201. As mentioned above, the power supply unit 100 also includes various other electrical components, but their illustration is incomplete. Figure 3 The middle part is omitted.

[0030] Circuit board 201 is positioned approximately perpendicular to the horizontal plane, and its surface extends approximately parallel to the XZ plane. Circuit board 201 is also secured to the inner wall of power supply housing 200 with screws 153. A primary electrolytic capacitor 105 is mounted on circuit board 201 such that it protrudes towards the negative side in the Y direction. In contrast, commercial power supply 101 ( Figure 2The power supply unit 100 is connected to the inlet 110 via a power cable (not shown), and the inlet 110 is connected to the power supply unit 100 via a cable 111.

[0031] Figure 4 This is a perspective view showing the configuration of the power supply device 100 according to this exemplary embodiment. Figure 4 Only the main components are shown. Circuit board 201, from top to bottom in the Z direction, includes a primary electrolytic capacitor 105, a diode bridge 104, a heat sink 109 (plate-like component), and jumpers 112 and 113 (electrical components). The surface on the negative Y-direction side of circuit board 201 where these components are mounted is called mounting surface 205. The diode bridge 104 between components on circuit board 201 is prone to heat generation; therefore, the diode bridge 104 is directly mounted on the heat sink 109 to make contact with it. Jumpers 112 and 113 are electrical components used for pattern wiring on circuit board 201. The potential of jumper 112 is equal to potential DCL, and the potential of jumper 113 is equal to potential DCH.

[0032] As described above, the primary electrolytic capacitor 105 protrudes towards the negative side in the Y direction, and an explosion-proof valve 120 (also referred to as a "pressure valve") is provided at the distal end of the primary electrolytic capacitor 105. In the event that the primary electrolytic capacitor 105 is abnormally subjected to a voltage higher than or equal to a predetermined value, the explosion-proof valve 120 opens and releases gas containing electrolyte, thereby preventing an increase in pressure within the primary electrolytic capacitor 105. Since the electrolyte is a conductive liquid, electrolyte adhering to the path between jumpers 112 and 113, which are two electrical components with different potentials, could cause a short circuit, potentially leading to excessive current flow. Therefore, it is necessary to prevent electrolyte from adhering to electronic components such as jumpers 112 and 113.

[0033] To prevent electrolyte from adhering to jumpers 112 and 113, in a configuration according to an exemplary embodiment, a heat sink 109, positioned vertically between the primary electrolytic capacitor 105 and jumpers 112 and 113, has a designed shape. For example... Figure 4 As shown, the heat sink 109 includes a cutout 130. The cutout 130 is formed on one side 133 (the negative side in the Y direction) near the circuit board 201, in the direction in which the primary electrolytic capacitor 105 protrudes. Furthermore, the heat sink 109 includes a curved portion and surfaces 131 and 132. A diode bridge 104 is mounted on surface 131 (a predetermined surface), and surface 132 intersects surface 131 in a manner substantially perpendicular to surface 131. The cutout 130 is formed at the curved portion 134 where the two surfaces 131 and 132 intersect.

[0034] The four corners of the surface 131 of the heat sink 109 are designated as points A, B, C, and D. Point A is located at the end portion of the surface 131 on the negative Y-direction and positive X-direction sides. Point B is located at the end portion of the surface 131 on the negative Y-direction and negative X-direction sides. Point C is located at the end portion of the cutout 130 on the negative Y-direction side. Point D is located at the end portion of the surface 131 on the positive Y-direction and positive X-direction sides.

[0035] The heat sink 109 is mounted substantially perpendicular to the mounting surface 205 of the circuit board 201. However, in practice, the heat sink 109 can be mounted at a slight angle relative to the circuit board 201 within a range of precision variations. Therefore, in Figure 4 In the configuration shown where jumpers 112 and 113 are positioned vertically below point C, regardless of the direction in which the heatsink 109 is tilted, it is necessary to prevent electrolyte from adhering to jumpers 112 and 113. Below... Figures 5 to 8 The installation states of the radiator 109 tilted in different directions are shown.

[0036] Figure 5 This is a view showing the power supply unit 100 and the power supply housing 200 as viewed along the mounting surface 205 of the circuit board 201. Specifically, Figure 5 This is a diagram showing the power supply unit 100 and the power supply housing 200 when viewed from the positive side to the negative side in the X direction. Figure 5 This illustration shows a state in which the explosion-proof valve 120 is open, and electrolyte 114 ejected from the primary electrolytic capacitor 105 scatters in different directions and adheres to the inner wall 220 of the power supply housing 200 facing the primary electrolytic capacitor 105 and the upper surface of the heat sink 109. The heat sink 109 is inclined relative to the mounting surface 205, and... Figure 5 In the middle, the position of the end portion of the heat sink 109 near the circuit board 201 (point C) is lower in the vertical direction than the position of the other end portion of the heat sink 109 on the side opposite to the circuit board 201 (point B).

[0037] exist Figure 5 In the middle, the radiator 109 is tilted such that the electrolyte 114 splashed onto the radiator 109 flows from point B to point C. Because the radiator 109 includes cutouts 130 (e.g., ... Figure 4 As shown), electrolyte 114 falls vertically from point C. Figure 5As shown, the position Y2 in the Y direction of point C is farther from the circuit board 201 than the position Y1 in the Y direction of jumpers 112 and 113 exposed from the mounting surface 205. Specifically, at least a portion of the area where the cutout 130 is formed is farther from the mounting surface 205 of the circuit board 201 in the Y direction than the positions of jumpers 112 and 113. Therefore, the electrolyte 114 falling from point C falls onto the bottom surface of the power supply housing 200 without adhering to jumpers 112 and 113.

[0038] Specifically, through the cut 130, the electrolyte 114, which would normally fall after being guided to a position close to the circuit board 201, will fall from a position away from the circuit board 201. This prevents the electrolyte 114 from adhering to the jumpers 112 and 113 located vertically below the primary electrolytic capacitor 105.

[0039] Figure 6 The heat sink 109 is shown in relation to Figure 5 The state shown is tilted in the opposite direction to the tilt shown. Figure 6 In this configuration, the position (point C) of the end portion of the heat sink 109 near the circuit board 201 is vertically higher than the position (point B) of the other end portion of the heat sink 109 on the side opposite to the circuit board 201. In this case, the electrolyte 114 that has splashed onto the heat sink 109 flows from point C to point B, causing the electrolyte 114 to... Figure 6 Point B in the middle falls vertically. For example... Figure 6 As shown, position Y4 in the Y direction of point B is farther from circuit board 201 than position Y1 in the Y direction of jumpers 112 and 113 exposed from mounting surface 205. Therefore, electrolyte 114 falling from point B falls onto the bottom surface of power supply housing 200 without adhering to jumpers 112 and 113.

[0040] The position Y4 of point B in the Y direction is farther from the circuit board 201 than the position Y3 of the distal portion of the primary electrolytic capacitor 105. In other words, the heat sink 109 protrudes from the circuit board 201 beyond the primary electrolytic capacitor 105. Therefore, the heat sink 109 acts as a protective shield for jumpers 112 and 113, preventing the electrolyte 114 ejected from the distal portion of the primary electrolytic capacitor 105 from being reflected by the inner wall 220 and adhering to jumpers 112 and 113. Figure 5 The same effect is achieved in the state shown.

[0041] Figure 7 This is a diagram showing the power supply device 100 as viewed from a direction perpendicular to the mounting surface 205 of the circuit board 201. Specifically, Figure 7 This is a diagram showing the power supply device 100 when viewed from the negative side to the positive side in the Y direction. Furthermore, as... Figure 7 As shown, the surface 131 of the heat sink 109 on which the diode bridge 104 is mounted extends in a direction intersecting the vertical direction, and the surface 131 is inclined relative to the horizontal direction, such that the position of point A is higher than the position of point B in the vertical direction.

[0042] In this case, the electrolyte 114 that splashes onto the radiator 109 flows downstream in the vertical direction, i.e., from point A to point B. Since the surface 131 of the radiator 109 is inclined relative to the horizontal direction, the electrolyte 114 is guided to the curved portion 134. The curved portion 134 is formed by bending the radiator 109, thereby accumulating the electrolyte 114 that has flowed to point B at the curved portion 134. Subsequently, as... Figure 5 or Figure 6 As shown, the electrolyte 114 accumulated at the bend 134 flows to point B or point C depending on the tilt direction of the heat sink 109. In both states, the electrolyte 114 does not adhere to jumpers 112 and 113, as referenced above. Figure 5 and Figure 6 As stated above.

[0043] Figure 8 The heat sink 109 is shown in relation to Figure 7 The state shown is tilted in the opposite direction to the tilt shown. Figure 8 In this configuration, the surface 131 of the heat sink 109 extends in a direction intersecting the vertical direction, and the surface 131 is inclined such that the position of point A is lower in the vertical direction than the position of point B. In this configuration, the electrolyte 114 that splashes onto the heat sink 109 flows from point B to point A and falls into an area along the X direction away from jumpers 112 and 113.

[0044] The above configuration prevents electrolyte 114 from adhering to jumpers 112 and 113.

[0045] As described above, the configuration of jumpers 112 and 113 arranged vertically below point C includes a cutout 130 to prevent electrolyte 114 from adhering to electrical components regardless of the direction in which the heat sink 109 is tilted.

[0046] although Figures 5 to 8 A heat sink 109 is shown that is inclined relative to the mounting surface 205 of the circuit board 201, but the heat sink 109 may not be inclined relative to the mounting surface 205 and may be approximately perpendicular to the mounting surface 205.

[0047] Although jumpers 112 and 113 are positioned vertically below point C in the above configuration, a cut can be formed near point D if jumpers 112 and 113 are positioned vertically below point D. This configuration will be described below.

[0048] Figure 9 This is a perspective view showing the power supply unit 100, with jumpers 112 and 113 positioned vertically below point D. The heat sink 109 includes not only cutout 130 but also cutout 135 near point D. Point E is located at the end portion of cutout 135 on the negative Y-direction side. Cutout 130 is optional.

[0049] Figure 10 This shows the view when viewed from a direction perpendicular to the mounting surface 205 of the circuit board 201. Figure 8 A view of the power supply device 100. Figure 10 The diagram shows the surface 131 of the heat sink 109 tilted relative to the horizontal direction due to variations in precision. Because the surface 131 is tilted such that point B is higher in the vertical direction than point A, the electrolyte 114 that splashes onto the heat sink 109 flows from point B to point A.

[0050] Figure 11 This shows the view along the mounting surface 205 of the circuit board 201. Figure 8 A view of the power supply unit 100 and the power supply housing 200. Figure 11 In the configuration shown, since point E is vertically lower than point A, electrolyte 114 flows from point A to point E. Therefore, electrolyte 114 falls vertically from point E. The Y-direction position Y6 of point E is farther from the circuit board 201 than the Y-direction position Y5 of jumpers 112 and 113 exposed from the mounting surface 205. Therefore, the electrolyte 114 that has fallen from point E falls onto the bottom surface of the power supply housing 200 without adhering to jumpers 112 and 113.

[0051] Radiator 109 in relation to Figure 10 and Figure 11 The tilting directions shown are different, and the installation states are similar to those in the reference above. Figures 5 to 8 The content being described is omitted, therefore repeated descriptions are omitted.

[0052] As described above, the configuration of jumpers 112 and 113 arranged vertically below point D includes a cut 135 to prevent electrolyte 114 from adhering to jumpers 112 and 113.

[0053] Although the cutout is formed at the end portion of the heat sink 109 in the above configuration according to the first exemplary embodiment, aspects of the present invention are not limited to the above configuration. Figure 12 As shown, the heat sink 109 may include holes 136. Electrolyte 114 that splashes onto the heat sink 109 falls vertically from the holes 136 located at a position away from the mounting surface 205 of the circuit board 201. This configuration similarly prevents electrolyte 114 from adhering to jumpers 112 and 113.

[0054] Furthermore, although the above-described configuration according to the first exemplary embodiment includes cutouts or holes at the curved portion 134 of the heat sink 109, aspects of the invention are not limited to these configurations. For example, although in Figure 7 The cutout 130 is located at the curved portion 134 (i.e., at the downstream end of the radiator 109 in the vertical direction, which is inclined relative to the horizontal direction), but the cutout 130 may also be formed at a position slightly offset from the curved portion 134 in the positive X direction.

[0055] As described above, according to this exemplary embodiment, the heat sink 109 includes cutouts or holes to prevent electrolyte 114 ejected from the primary electrolytic capacitor 105 from adhering to jumpers 112 and 113.

[0056] The configuration described above according to the first exemplary embodiment prevents electrolyte 114 from adhering to jumpers 112 and 113 by using a heat sink 109 mounted on the circuit board 201. However, there may be cases where the power supply device 100 does not include a heat sink 109.

[0057] According to the second exemplary embodiment, a dedicated component for preventing electrolyte 114 from adhering to jumpers 112 and 113 is intentionally tilted relative to the mounting surface 205 so that it is mounted on the mounting surface 205 in an tilted state. The basic device configuration of the second exemplary embodiment is similar to that described according to the first exemplary embodiment, and therefore its repeated description is omitted. A configuration different from the first exemplary embodiment will be described here.

[0058] Figure 13 The configuration of a power supply device 100 including a guide plate 202 (plate-like member) for guiding electrolyte 114 is shown. Figure 13 This is a diagram showing the power supply unit 100 as viewed along the mounting surface 205 of the circuit board 201. Figure 13 In the circuit, the guide plate 202 is located between the primary electrolytic capacitor 105 and the diode bridge 104 in the Z direction, and is mounted to tilt in the -Z direction as the distance from the circuit board 201 increases.

[0059] The guide plate 202 is a component used to guide the electrolyte 114 to a position away from jumpers 112 and 113. The guide plate 202 is, for example, a resin component. Furthermore, the guide plate 202 is mounted on the circuit board 201 with an intentional tilt relative to the mounting surface 205, rather than a tilt within a range of precision variations. Specifically, the tilt angle θ of the guide plate 202 relative to an extension line extending perpendicularly to the mounting surface 205 of the circuit board 201 is preferably 10 degrees or more.

[0060] In this configuration, the electrolyte 114, which has adhered to the guide plate 202, flows towards the negative side in the Y direction and falls from the distal portion 203 of the guide plate 202 in the negative Z direction. Therefore, the electrolyte 114 falls onto the bottom surface of the power supply housing 200 without adhering to the jumpers 112 and 113.

[0061] As described above, according to this exemplary embodiment, a guide plate 202 is provided for guiding the electrolyte 114 so that even without a plate-like member such as a heat sink 109, the electrolyte 114 ejected from the primary electrolytic capacitor 105 can be prevented from adhering to the jumpers 112 and 113.

[0062] <Variant Example>

[0063] Although the heat sink 109 includes cutouts or holes in the configuration according to the first exemplary embodiment, aspects of the invention are not limited to these configurations. A guide plate 202 according to the second exemplary embodiment may be provided instead of the heat sink 109, and cutouts or holes may be formed in the guide plate 202.

[0064] Furthermore, although the guide plate 202 is intentionally tilted and mounted on the mounting surface 205 in the configuration according to the second exemplary embodiment, aspects of the invention are not limited to this configuration. A heat sink 109 according to the first exemplary embodiment may be provided instead of the guide plate 202, and the heat sink 109 may be intentionally tilted and mounted on the mounting surface 205.

[0065] Furthermore, although the diode bridge 104 described in the first and second exemplary embodiments is mounted on the heat sink 109, aspects of the present invention are not limited to these configurations. Other components that are prone to heat generation include the FET 107 as a switching element and the rectifier diodes (not shown) of the rectifier unit 151 in the secondary circuit, and these components may be in contact with the heat sink 109.

[0066] Although jumpers 112 and 113 described according to the first and second exemplary embodiments are examples of electrical components disposed vertically below the primary electrolytic capacitor 105, it is not necessary to provide both electrical components. For example, only jumper 112 may be provided. In this case, electrolyte 114 adhering to the area near jumper 112 may cause a short circuit between jumper 112 and the bottom surface of the power supply housing 200 or ground. Furthermore, since the heat sink 109 has a predetermined potential, a short circuit may occur between jumper 112 and heat sink 109. In addition, the electrical component is not limited to jumper 112, but may also be other electrical components disposed for the primary circuit of transformer 108, such as resistors or diodes.

[0067] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such variations and equivalent structures and functions.

Claims

1. An image forming apparatus, comprising: An image forming unit configured to form an image on a recording material; as well as A power supply device configured to supply power to the image forming unit, the power supply device including a circuit board arranged perpendicular to the horizontal plane. The power supply device includes: An electrolytic capacitor, the electrolytic capacitor including an explosion-proof valve configured to open and eject internal electrolyte when a voltage higher than or equal to a predetermined value is applied, the electrolytic capacitor protruding from the mounting surface of the circuit board along a first direction; An electrical component located vertically below the electrolytic capacitor, the electrical component being exposed from the mounting surface; and A plate-shaped member is disposed vertically between the electrolytic capacitor and the electrical component, the plate-shaped member including a first surface extending in a second direction intersecting the vertical direction when viewed in a direction perpendicular to the mounting surface of the circuit board. The plate-like member includes a cut or hole, and at least a portion of the area forming the cut or hole is located further away from the mounting surface of the circuit board in the first direction than the location of the electrical component exposed from the mounting surface.

2. The image forming apparatus of claim 1, wherein the plate-like member includes a cut formed on the side closest to the circuit board in the first direction, and the end portion of the cut on the side opposite to the circuit board is located further away from the mounting surface of the circuit board in the first direction than the location of the electrical component.

3. The image forming apparatus of claim 1, wherein the plate-like member includes at least one curved portion and, in addition to the first surface, includes a second surface intersecting the first surface, the cut or hole being formed at the curved portion where the first surface and the second surface intersect.

4. The image forming apparatus of claim 1, wherein when viewed in a direction perpendicular to the mounting surface of the circuit board, the second direction is inclined relative to the horizontal direction, and the cut or hole is formed in the downstream end of the plate-like member in the vertical direction.

5. The image forming apparatus of claim 1, wherein the plate-shaped member is inclined relative to the mounting surface such that, when viewed along the mounting surface of the circuit board, the position of the end portion of the plate-shaped member closest to the circuit board in the first direction is lower in the vertical direction than the position of the other end portion of the plate-shaped member on the side opposite to the circuit board.

6. The image forming apparatus of claim 1, wherein, when viewed along the mounting surface of the circuit board, the plate-like member protrudes beyond the distal portion of the electrolytic capacitor in the first direction.

7. An image forming apparatus, comprising: An image forming unit configured to form an image on a recording material; as well as A power supply device configured to supply power to the image forming unit, the power supply device including a circuit board arranged perpendicular to the horizontal plane. The power supply device includes: An electrolytic capacitor, the electrolytic capacitor including an explosion-proof valve configured to open and eject internal electrolyte when a voltage higher than or equal to a predetermined value is applied, the electrolytic capacitor protruding from the mounting surface of the circuit board along a first direction; An electrical component located vertically below the electrolytic capacitor, the electrical component being exposed from the mounting surface; and A plate-shaped member is disposed vertically between the electrolytic capacitor and the electrical component, the plate-shaped member including a first surface extending in a second direction intersecting the vertical direction when viewed in a direction perpendicular to the mounting surface of the circuit board. When viewed along the mounting surface of the circuit board, the plate-like member protrudes beyond the distal portion of the electrolytic capacitor in the first direction, and the plate-like member is inclined relative to the mounting surface such that, when viewed along the mounting surface of the circuit board, the position of the end portion of the plate-like member closest to the circuit board in the first direction is higher in the vertical direction than the position of the other end portion of the plate-like member on the side opposite to the circuit board, and the position of the other end portion is further away from the circuit board in the first direction than the position of the electrical component exposed from the mounting surface.

8. The image forming apparatus of claim 7, wherein the plate-shaped member is inclined at more than 10 degrees relative to a direction perpendicular to the mounting surface of the circuit board.

9. The image forming apparatus according to any one of claims 1 to 8, wherein the plate-like member is a heat sink configured to dissipate heat from the power supply device.

10. The image forming apparatus of claim 9, further comprising a diode bridge configured to convert alternating current supplied from a commercial power source into direct current. The diode bridge is in contact with the heat sink.

11. The image forming apparatus according to any one of claims 1 to 8, wherein the plate-like member is a guide plate configured to guide the electrolyte in a predetermined direction.

12. The image forming apparatus according to any one of claims 1 to 8, further comprising a transformer having a primary winding and a secondary winding and configured to output a voltage to the secondary winding according to a voltage input to the primary winding. The electrical component mentioned above is a jumper wire installed on the primary circuit of the transformer.

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