JP2009238787A - Electronic circuit module and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an another technique for controlling the drive of a cooling fan with high accuracy based on the temperatures of a heat-generating component in a power feeding apparatus using the cooling fan to forcibly radiate heat of the heat-generating components. <P>SOLUTION: The power feeding apparatus is provided with: a voltage step-down device for stepping down a predetermined primary side voltage to a predetermined secondary side voltage lower than the primary side voltage while insulating a primary side from a secondary side; a heat-generating component involving a large amount of heat generation and connecting to the primary side of the voltage step-down device; a hollow case accommodating the heat-generating component and the voltage step-down device in the inside and having a primary side region having the heat-generating component disposed therein; and an air blow guiding section of which at least a part thereof is disposed on the primary side region and which discharges an air flowing through the periphery of the heat-generating component to the outside. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic circuit module including a heat generating component.

  Conventionally, a power supply device such as a power supply unit or a ballast unit includes a heat generating component such as a power FET that generates a large amount of heat. Therefore, the operation may become unstable due to a temperature rise due to heat generation of the heat generating component. Therefore, a power supply device such as a power supply unit forcibly dissipates these heat generating components by a cooling fan.

  Since the temperature of heat-generating components varies depending on the operating conditions, conventionally, for example, the temperature of air in the vicinity of the power supply unit is detected by a temperature sensor such as a thermistor in order to optimize the fan voltage according to the temperature of the heat-generating components. Feedback control. Then, since the temperature of the heat generating component is not directly detected, there is a possibility that accurate feedback control cannot be performed.

  In general, a power supply unit includes a transformer for supplying electric power by stepping down a high-voltage commercial power supply, and main heat-generating components are connected to the primary side of the transformer. A control circuit that performs feedback control is connected to the secondary side. Therefore, in order to solve the above-described problems, Patent Document 1 proposes a technique in which a temperature sensor is disposed at a position close to a primary heat generating component in a power supply unit. In this case, since the temperature sensor is connected to the primary side, the temperature sensor is connected to the primary side via a photocoupler, an insulation transformer, or the like in order to maintain an insulation state between the primary side and the secondary side. Temperature information is transmitted from the temperature sensor to the control circuit connected to the secondary side.

JP 2006-145824 A

  However, in the above-described method, a photocoupler, an insulation transformer, or the like is used to transmit temperature information to the control circuit, so that the number of parts increases and the detected temperature is converted into an electrical signal such as a PWM signal. This circuit is also required, which increases the cost.

  Therefore, in view of the above-described problems of the conventional technology, the present invention accurately controls the driving of the cooling fan based on the temperature of the heat generating component in the power supply device that forcibly dissipates the heat generating component with the cooling fan. The purpose is to provide other technologies.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1] A power supply device,
A step-down circuit for stepping down a predetermined primary side voltage to a predetermined secondary side voltage lower than the primary side voltage while insulating the primary side and the secondary side;
A heat generating component with a large amount of heat connected to the primary side of the step-down device;
A hollow case in which the heat generating component and the step-down device are disposed, and having a primary side region in which the heat generating component is disposed;
At least a part of which is a wind guide portion disposed in the primary region, and the wind guide portion that discharges the wind flowing in the vicinity of the heat generating component to the outside of the case;
A power supply device comprising:

  In general, in an electric / electronic device including a power supply device, a heat generating component in the power supply device is cooled using a cooling fan. When the power supply device according to the application example 1 is used, the wind flowing in the vicinity of the heat generating component is discharged outside the power supply device. Therefore, if the temperature detection unit is arranged so that the temperature of the discharged wind can be detected, heat is generated. The temperature of the component can be detected with higher accuracy. Therefore, the driving of the cooling fan can be controlled with higher accuracy based on the temperature information detected by the temperature detection unit.

[Application Example 2] The power supply device according to Application Example 1,
The said air guide part is an electric power supply apparatus which consists of an insulator.

  In general, in an electric / electronic device including a power supply device, a cooling fan for cooling a heat generating component in the power supply device, a cooling fan drive circuit for controlling the driving of the cooling fan, and a detection unit for detecting the temperature of the heat generating component Is connected to the secondary side of the buck. When the air guide part is made of an insulator, the primary side is connected to the temperature detection part via the air guide part even if a part of the air guide part is disposed in the primary region in the case. The possibility that a voltage is applied is reduced. Therefore, it is possible to improve the safety of the electric / electronic device including the power supply device.

  Note that the present invention is not limited to the above-described aspect of the power supply apparatus, and can also be realized as an aspect of a projector or the like provided with the power supply apparatus.

Hereinafter, the best mode for carrying out the present invention will be described in the following order based on examples.
A. Example:
A-1. Example configuration:
A-1-1. Power supply unit configuration:
A-2. Wind flow in the case:
A-3. Effects of the embodiment Variations:

A. Example:
A-1. Configuration of Embodiment FIG. 1 is a block diagram showing a configuration of a projector 1000 of the present invention. As illustrated, the projector 1000 includes a power supply device 800, a cooling unit 300, a control unit 400, a light source lamp 500, a liquid crystal panel 600, and a projection lens 700.

  The power supply device 800 includes a power supply unit 100 and a ballast unit 200. The power supply unit 100 includes a rectifier circuit 102 that converts commercial power (for example, AC 100V) into direct current by full-wave rectification, a PFC (Power Factor Correction) circuit 104 that suppresses harmonic current and improves power factor, A DC-DC flyback converter 106 that converts an output (for example, DC 380 V) of the PFC circuit 104 into a predetermined voltage (for example, DC 5 to 18 V) by the transformer 112. The power supply unit 100 generates operating power for operating the control unit 400 and fan driving power for operating the cooling unit 300 from a commercial power source. The transformer 112 in this embodiment corresponds to the step-down device in the claims, and the power supply unit 100 in this embodiment corresponds to the power supply apparatus in the claims.

  The ballast unit 200 is connected to the PFC circuit 104 included in the power supply unit 100, and the light source lamp 500 is driven by stepping down the output voltage (for example, DC380V) from the PFC circuit 104 by a step-down chopper (not shown). The light source driving power for generating is generated.

  The cooling unit 300 includes a cooling fan 310, a cooling fan control unit 320, and a temperature detection unit 330. As illustrated, the cooling fan 310, the cooling fan control unit 320, and the temperature detection unit 330 are connected to the secondary side of the transformer 112. As will be described later, the cooling fan 310 is disposed in contact with the power supply unit 100, sends air into the power supply unit 100, and forcibly cools components included in the power supply unit 100. The cooling fan 310 is operated by fan driving power supplied from the power supply unit 100. In this embodiment, an axial fan is used as the cooling fan 310, but a sirocco fan or the like may also be used.

  The cooling fan control unit 320 controls the rotation speed of the cooling fan 310 based on the temperature detected by the temperature detection unit 330. The cooling fan controller 320 and the temperature detector 330 are arranged on a mother board (not shown). Then, the cooling fan control unit 320 controls the rotation speed of the cooling fan 310 by regarding the temperature of the cooling air detected by the temperature detection unit 330 as the temperature of the heat generating component. In this embodiment, a thermistor is used as the temperature detection unit 330, but another known temperature sensor may be used. The cooling fan 310 in this embodiment corresponds to the cooling fan in the claims, and the temperature detection unit 330 corresponds to the temperature detection unit in the claims.

  The control unit 400 mainly includes a CPU 410, an image processing unit 420, and a memory 430. The CPU 410 performs various processes and controls according to the computer program stored in the memory 430. The image processing unit 420 performs image processing on image data given from the outside, such as a PC, a DVD player, an external memory, or the like connected to an external connection connector (not shown), and processed image data. Is supplied to the liquid crystal panel 600. The control unit 400 is connected to the secondary side of the transformer 112 and operates with the operating power generated by the power supply unit 100. The control unit 400 in this embodiment corresponds to the control unit in the claims. The cooling fan 310, the cooling fan control unit 320, the temperature detection unit 330, and the control unit 400 may be directly connected to the secondary side of the transformer 112, or may be further connected via a transformer or the like. Good.

  The light source lamp 500 irradiates the liquid crystal panel 600 with light, and performs a lighting operation with the light source driving power generated by the ballast unit 200. The liquid crystal panel 600 is a transmissive liquid crystal panel, modulates light emitted from the light source lamp 500 using image data provided from the image processing unit 420, and emits light representing an image. The projection lens 700 projects light emitted from the liquid crystal panel 600 onto a screen (not shown), and as a result, an image is displayed on the screen. The light source lamp 500 in this embodiment corresponds to the light source in the claims.

A-1-1. Power supply unit configuration:
FIG. 2 is a plan view schematically showing the configuration of the power supply unit 100, and FIG. 3 is an elevation view schematically showing the configuration of the power supply unit. FIG. 2 shows the arrangement of components and the flow of wind when the power supply unit 100 is viewed from the upper surface side (the z-axis plus direction is upward in the drawing). As shown in FIGS. 2 and 3, the power supply unit 100 includes a printed circuit board 110, a case 190, and an air guide duct 340. As shown in FIGS. 2 and 3, a cooling fan 310 of a system for sending wind is arranged on the intake side of the power supply unit 100. The air guide duct 340 in this embodiment corresponds to the air guide portion in the claims.

  2 and 3, the printed circuit board 110 has a transformer 112, a coil 113, a capacitor 114, a coil 115, a MOSFET (Metal Oxide Field Field Transistor) 116, and a MOSFET 117 on one surface of the printed wiring board 111. Is arranged.

  In this embodiment, as shown in FIG. 2, a coil 113, a capacitor 114, a coil 115, and a MOSFET 116 (hereinafter collectively referred to as a primary side component) electrically connected to the primary side of the transformer 112 are A MOSFET 117 (hereinafter also referred to as a secondary side component) disposed on the left side in FIG. 2 and electrically connected to the secondary side of the transformer 112 is disposed on the right side in FIG. In this embodiment, in the space in the case 190, a region where the coil 113, the capacitor 114, the coil 115, and the MOSFET 116 are arranged is called a primary side region, and a region where the MOSFET 117 is arranged is called a secondary side region. . As shown in FIG. 2, the primary side component connected to the primary side of the transformer 112 and the secondary side component connected to the secondary side of the transformer 112 are arranged with a predetermined insulation distance maintained. ing. The coil 113, the capacitor 114, the coil 115, and the MOSFET 116 in this embodiment correspond to the primary part in the claims, and the MOSFET 117 in this embodiment corresponds to the secondary part in the claims. 1 to 3, the boundary between the primary side region and the secondary side region is indicated by a one-dotted line, and the primary side region is “primary side” and the secondary side region is “secondary side”. It is abbreviated and shown.

  In this embodiment, the coil 113 and the MOSFET 116 generate a larger amount of heat than other components. As shown in the figure, the MOSFET 116 is screwed to the heat radiating plate 116h, and part of the heat generated by the MOSFET 116 is radiated through the heat radiating plate 116h. The coil 113 and the MOSFET 116 in the present embodiment correspond to heat generating components in the claims.

  The heat sink 116h is a flat plate made of aluminum having high thermal conductivity. As described above, since the MOSFET 116 is screwed to the heat sink 116h, a part of the heat of the MOSFET 116 is transferred from the surface in contact with the heat sink 116h to the heat sink 116h by conduction. It is transmitted from the surface of 116h to the air by radiation (radiation) and convection (transmission). In the present embodiment, aluminum is used as the material of the heat sink 116h, but other materials having high thermal conductivity such as copper may be used.

  As described above, since the MOSFET 116 is efficiently radiated heat through the heat radiating plate 116h, the coil 113 can be the hottest among the components included in the power supply unit 100. Therefore, in this embodiment, it is preferable to control the rotation speed of the cooling fan 310 based on the temperature of the coil 113.

  As shown in FIGS. 2 and 3, the case 190 functions as an intake port with one opening of the case 190 having a substantially quadrangular cross-sectional shape as an exhaust port. In this embodiment, polystyrene-modified polyphenylene ether (PPE + PS) is used as the material of the case 190, but other heat-resistant resins may be used.

  The air duct 340 is a cylindrical duct made of an insulating resin material. As shown in FIGS. 2 and 3, it is disposed in the vicinity of the coil 113 and is not in contact with the coil 115 and the coil 113. As shown in FIG. 3, the wind flowing in the case 190 is caused to flow out of the case 190. In this embodiment, polystyrene-modified polyphenylene ether (PPE + PS) is used as the material of the air guide duct 340, as in the case 190, but other heat-resistant and insulating resins may be used.

A-2. Wind flow in the case:
In the present embodiment, as shown in FIG. 2, a cooling fan 310 is disposed on the intake side of the power supply unit 100, and air is sent into the case 190 to flow wind. When air is sent into the case 190 by the cooling fan 310, the air flows into the case 190 in a certain direction, as shown by arrows in FIG. 2, that is, from the secondary side region to the primary side region. Flows.

  Since the air guide duct 340 is disposed in the vicinity of the coil 113 and the air guide duct 340 opens toward the wind in the case 190, the air in the vicinity of the coil 113 is caused to flow by the wind flow. It is discharged out of the case 190 via 340. In this embodiment, the cooling fan 310 is arranged on the intake port side and the wind is sent, but the cooling fan 310 may be arranged on the exhaust port side to suck out the wind. . Further, the cooling fan 310 may be arranged on both the intake port side and the exhaust port side.

A-3. Effects of the embodiment:
As described above, in the projector 1000 according to the present embodiment, since the power supply unit 100 includes the air guide duct 340, the air in the primary side region under the high voltage atmosphere can be discharged out of the case 190. And since the temperature detection part 330 is arrange | positioned in the vicinity of the air discharge port of the baffle duct 340, the temperature detection part 330 provided outside the case 190 detects the temperature of the case 190 in the vicinity of the heat generating component. be able to. Since the cooling fan 310 is controlled based on the temperature information detected by the temperature detection unit 330, the temperature of the heat generating component is detected more accurately, and the cooling fan 310 is controlled by the cooling fan control unit 320. It becomes possible to control more accurately.

  In addition, as described above, the temperature detection unit 330 is connected to the secondary side of the transformer 112, and the heat generating component is connected to the primary side of the transformer 112. If the temperature detection unit 330 is disposed in the vicinity of the heat-generating component for the purpose of detection, the insulation distance cannot be maintained, and a discharge phenomenon may occur, and a high voltage may be applied to the temperature detection unit 330. However, in the present embodiment, the temperature detection unit 330 is disposed outside the case 190, maintains a sufficient insulation distance from the primary side component, and is isolated by the insulating case 190. Yes. Further, since the air duct 340 is also made of an insulating material, there is no possibility that a high voltage is applied to the temperature detection unit 330.

  Therefore, it is possible to accurately control the driving of the cooling fan based on the temperature of the heat generating component with a simple configuration in which the wind in the case 190 is discharged outside the case 190 using the air guide duct 340. it can. Further, since both the temperature detection unit 330 and the cooling fan control unit 320 are connected to the secondary side of the transformer 112, insulation is performed when temperature information is sent from the temperature detection unit 330 to the cooling fan control unit 320. Since there is no need and no parts required for insulation such as a photocoupler are required, an increase in cost can be suppressed.

B. Variations:
The present invention is not limited to the above-described embodiments, and can be carried out in various modes without departing from the gist thereof.

  (1) In the above-described embodiment, the projector 1000 modulates the light from the light source lamp 500 using the transmissive liquid crystal panel 600. However, the projector 1000 is not limited to the transmissive liquid crystal panel 600. -You may make it the structure which modulates the light from a light source lamp using a micromirror device (DMD: Digital Micro-Mirror Device), a reflective liquid crystal panel (LCOS: Liquid Crystal on Silicon), etc. FIG.

  (2) In the above-described embodiments, the power supply unit 100 has been described as an example of the power supply device. However, for example, a ballast unit may be used. When the heat generating component is connected to the primary side of the high voltage, applying the present invention generates heat while maintaining insulation from the temperature detection unit and the cooling fan control unit connected to the secondary side of the transformer. The cooling fan can be accurately controlled by detecting the temperature of the component almost accurately.

  (3) In the above-described embodiment, the configuration in which the wind flows in the case 190 from the secondary side region to the primary side region is illustrated, but the direction of the wind flowing in the case 190 has been described above. The present invention is not limited to the examples. For example, FIG. 4 is a plan view schematically showing a configuration of a power supply unit 100B of a modified example. The power supply unit 100B is different from 100 in the above-described embodiment in the arrangement of components on the printed circuit board 110B and the arrangement of the air guide duct 340B. As shown in the figure, in the power supply unit 100B, the primary side region where the primary side component connected to the primary side of the transformer 112B is arranged, and the secondary side component connected to the secondary side of the transformer 112B is arranged. The secondary side area formed by the cooling fan 310 is formed in parallel with the flow of wind generated in the case 190. In such a case, for example, if the coil 113 is a heat generating component that generates more heat than the other components, the wind guide duct 340B is placed downstream of the coil 113 in the case 190 as shown in FIG. What is necessary is just to arrange | position so that it may open toward. If it does in this way, the same effect as an above-mentioned example can be acquired.

  (4) In the above-described embodiment, the thermistor as the temperature detection unit 330 is mounted on the mother board. However, for example, the thermistor may be mounted on a small board other than the mother board. 190 can be arranged outside.

  (5) In the above-described embodiment, the air guide duct 340 is used as the air guide portion, but the shape of the air guide portion is not limited to the duct shape. For example, FIG. 5 is an elevation view schematically showing a configuration of a power supply unit 100C according to a modification. In the power supply unit 100C, instead of the air guide duct 340 in the above-described embodiment, a through hole 340h and a fin 340f for guiding the wind to the through hole are provided in the vicinity of the heat generating component on the upper surface of the case 190. Even in this case, the wind in the vicinity of the heat generating component can be discharged out of the case, so that the same effect as the above-described embodiment can be obtained.

It is a block diagram which shows the structure of the projector 1000 of this invention. 2 is a plan view schematically showing a configuration of a power supply unit 100. FIG. It is an elevation view which shows the structure of a power supply unit roughly. It is a top view which shows roughly the structure of the power supply unit 100B of a modification. It is an elevation view schematically showing a configuration of a power supply unit 100C of a modification.

Explanation of symbols

100, 100A, 100B, 100C ... power supply unit 102 ... rectifier circuit 104 ... PFC circuit 110, 110B ... printed circuit board 111 ... printed wiring board 112 ... transformer 113 ... coil 114 ... capacitor 115 ... coil 116 ... MOSFET
116h ... heat sink 117 ... MOSFET
DESCRIPTION OF SYMBOLS 190 ... Case 200 ... Ballast unit 300 ... Cooling part 310, 310A ... Cooling fan 320 ... Cooling fan control part 330 ... Temperature detection part 340, 340A, 340B ... Air guide duct 340f ... Fin 340h ... Through-hole 400 ... Control part 410 ... CPU
420 ... Image processing unit 430 ... Memory 500 ... Light source lamp 600 ... Liquid crystal panel 700 ... Projection lens 800 ... Power supply device 1000 ... Projector

Claims (3)

A power supply device,
A step-down circuit for stepping down a predetermined primary side voltage to a predetermined secondary side voltage lower than the primary side voltage while insulating the primary side and the secondary side;
A heat generating component with a large amount of heat connected to the primary side of the step-down device;
A hollow case in which the heat generating component and the step-down device are disposed, and having a primary side region in which the heat generating component is disposed;
At least a part of which is a wind guide portion disposed in the primary region, and the wind guide portion that discharges the wind flowing in the vicinity of the heat-generating component to the outside of the case;
A power supply device comprising: The power supply device according to claim 1,
The said air guide part is an electric power supply apparatus which consists of an insulator. A projector,
The power supply device according to claim 1 or 2,
A cooling fan connected to the secondary side of the step-down device and generating wind in the case;
A temperature detection unit that is disposed outside the case and connected to the secondary side of the step-down device and detects the temperature of the wind emitted through the air guide unit;
A cooling fan controller that is connected to the secondary side of the step-down device and controls the cooling fan based on the temperature detected by the temperature detector;
A light source to which power is supplied from the power supply device;
A control unit for modulating the light from the light source based on image data supplied with power from the power supply device;
A projector provided.

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