JP2008292953A - Cooling structure of dlp system projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase cooling efficiency in a DLP system projector. <P>SOLUTION: On light L1 from a DMD device 41 enters a projection lens 31, to form an image on a screen, while, for instance, the top surface of a housing 21 in the figure is irradiated with off light L3. In the top surface, an opening 45 is provided in a width area W2 corresponding to the width W1 of the DMD device 41. In a wall surface in which the opening is formed, in an area out of the opening 45, a metallic housing plate and a heat insulating material plate 53 whose thermal conductivity is low, such as plastic are formed in order from the inside and a heat radiating member which is an off light radiating section 55 and provided with a fin, for instance, is formed outside the heat insulating material plate 53. On the other hand, the metallic housing plate is not provided in the opening 45, but the opening 45 is covered with the off light radiating section 55 being a metal different from a metallic housing. Further, a material 51 (heat-resistant black paint, etc.) whose thermal conductivity is not excellent is provided inside the opening, to absorb the heat of the off light. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooling structure for a DLP projector using a digital micromirror device (hereinafter referred to as “DMD element”), and in particular, can reduce the influence of heat on the DMD element due to off-light. The present invention relates to a cooling structure for a DLP projector.

  The DMD, which is a display element used in a DLP projector, reflects light in a direction not taken into the projection lens by tilting a mirror when light is not used, that is, when black is expressed. This light is hereinafter referred to as “off light”. In the conventional DLP projector, the off-light is applied to the wall surface of a metal casing (made of aluminum, magnesium, or the like) for mounting an optical component. The irradiated area is made of heat-resistant black paint so that it is not taken into the projection lens.

  For example, Patent Document 1 discloses a cooling structure as shown in FIG. FIG. 5 is a diagram illustrating a configuration example of a conventional general DLP projector. In the configuration shown in FIG. 5, in the substantially cubic metal casing 121, the light L from the lamp enters from the first surface, and the DMD is formed on one side surface with respect to the incident direction of the incident light L. An attachment position 141 is provided, and a DMD element is attached thereto.

  The on-light L1 of the DMD element is configured to travel toward the projection lens mounting portion 111 provided on the side surface facing the DMD mounting position 141, while the off-light L3 from the DMD element is the light of the lamp light L. Irradiation is performed on a housing inner surface 155 provided on a surface facing the incident surface. The heat dissipating part is provided with a heat transfer plate part and a heat dissipating fin standing on the surface side of the heat transfer plate part so that the off-light from the reflection mirror is irradiated on the back surface side of the heat transfer plate part. It has become. Cooling efficiency is improved by fins provided on the outer surface side of the housing and protruding outward. With the above configuration, even when off-light is generated without turning off the light source of the exposure head, the temperature of the member that affects the alignment of the digital micromirror device is prevented from rising due to off-light and expanding. Therefore, high-quality images with high resolution can be obtained stably.

JP 2004-301914 A

  However, since the technique described in Patent Document 1 is configured to irradiate off-light to a member that radiates the DMD from the back surface, the temperature of the heat sink (including the casing and fins) for cooling the DMD element Rises. As a result, the cooling efficiency of the DMD element is lowered.

  On the other hand, if there is a gap between the housing and the heat sink, dust enters the interior, and the quality of the image deteriorates. When there is no gap between the housing and the heat sink, there is a problem that the housing has heat conduction, and as a result, the temperature of the DMD element rises. The metal casing is heated by being irradiated with the off-light. Heating the metal casing has a detrimental effect that the temperature of the DMD attached to the metal casing increases (the lifetime of the DMD element varies depending on the temperature, so the temperature is preferably low).

  In the structure shown in FIG. 5, means for preventing the temperature rise of the metal casing to some extent has been taken by providing a heat-dissipating fin in the vicinity of the portion irradiated with the off-light.

  However, even if it is configured as shown in FIG. 5, the temperature rise of the metal casing due to the off-light is not reduced so much. The means for raising the voltage of the FAN to cool the DMD element and the means for cooling the DMD element. Although measures have been taken to enlarge the heat dissipating fins on the back side of the installed DMD, it has not been said that the sufficient effect has been achieved.

  An object of the present invention is to improve cooling efficiency in a DLP projector.

  According to one aspect of the present invention, there is provided an electronic apparatus having a metal housing and an element attached in the metal housing, wherein the unnecessary heat generation region in which unnecessary heat is generated from the element A first opening that opens a part of the metal housing is provided, a heat insulating material is disposed in a region that avoids the opening in the vicinity of the opening, and a heat sink is disposed in a region that includes the first opening. An electronic device cooling structure is provided.

  A DLP projector having a metal casing and a DMD element mounted in the metal casing, wherein the metal casing is disposed in an unnecessary heat generation region irradiated with off-light emitted from the DMD element. A first opening that opens a part of the first opening is provided, a heat insulating material is disposed in a region that avoids the first opening in the vicinity of the first opening, and heat is radiated to a region that includes the first opening. A cooling structure for a DLP projector is provided in which a plate is disposed apart from the metal casing.

In the above configuration, by disposing a heat sink in the region including the first opening apart from the metal casing, the metal casing is heated by unnecessary light and the influence on the characteristics of the DMD element is reduced. can do. It is preferable to provide an absorber for absorbing off-light in the first opening.
A DLP projector having a metal casing and a DMD element mounted in the metal casing, wherein the metal casing is disposed in an unnecessary heat generation region irradiated with off-light emitted from the DMD element. A first lid portion that is provided with a heat insulating material, and a first lid portion that is provided with a heat insulating material is provided in the vicinity of the first opening portion. There is provided a cooling structure for a DLP projector, comprising: a second lid portion made of metal, which is attached to one lid portion and provided in a region covering the first opening portion.

  The first opening is preferably provided in a recess formed in the first lid. Thereby, a 1st opening part can be made small. Moreover, it is preferable that the first opening and the second lid or the first opening and the heat radiating plate are in contact with each other. When a fan having an air passage is provided in the vicinity of the first opening, the cooling effect is improved.

  According to the cooling structure of the present invention, since it is configured not to conduct unnecessary heat to the element, there is an advantage that an increase in temperature of the element can be suppressed. In addition, since the size of the radiation fin for cooling the element can be reduced, the entire apparatus can be reduced in size. Furthermore, there is an advantage that a fan for cooling the main elements can be reduced in size, power consumption can be reduced, and silence can be achieved.

  In the structure as shown in FIG. 5, the inventor can provide one surface of the metal housing constituting the mounting portion of the DMD element and the off-light irradiating portion even if the off-light irradiating portion is provided with a heat dissipation mechanism such as a fin. As long as one surface of the metal casing is formed of the same integral metal material, it has been found that heat generated based on off-light travels through the casing plate and affects the DMD element. Therefore, it was considered that the influence of the off-light on the DMD element can be reduced by eliminating the connection of the off-light irradiating part and the mounting part of the DMD element by the same metal casing.

  The cooling structure in the DLP projector according to the first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of the overall configuration of a DLP projector according to this embodiment. As shown in FIG. 1, in the DLP projector A, an optical unit having a light source unit 1 and a lens unit 3 is roughly provided on the front side, and a power supply unit 5 is provided on the back side. It has been. The light source unit 1 is provided with a cooling fan 11.

  FIG. 2 is a principle diagram of a cooling structure in the DLP projector according to the present embodiment. As shown in FIG. 2, a projection lens 31 is provided on one surface (the left surface in the figure) of the housing 21, and a lens barrel 31a is fitted on one surface of the housing. On the other hand, an opening 32 is provided on the lower surface shown in FIG. 2, and the incident light enters the housing 21 from the opening 32. The incident light L is applied to the DMD element 41 attached to the surface (the right surface in the figure) facing the surface on which the projection lens 31 is provided. The on-light L1 from the DMD element 41 enters the projection lens 31 and forms an image on a screen. On the other hand, the off-light L3 is configured to be irradiated on the upper surface of the housing 21 in the figure, for example. On this upper surface, an opening 45 is provided in a width region W2 corresponding to the width W1 of the DMD element 41. On the wall surface where the opening 45 is formed, in the region outside the opening 45, the metal casing plate 21a, the heat insulating material plate 53 having a low thermal conductivity such as plastic, and the like are off from the inside. A light radiating member 55, for example, a heat radiating member provided with fins 55a is formed.

  On the other hand, the opening 45 is not provided with the metal casing plate 21a, and is covered with the off-light heat radiating portion 55, which is a metal different from the metal casing plate 21a, and the off-light inside the opening 45 is also covered. The heat dissipating part 55 is provided with (heat resistant black paint) 51 so as to absorb heat of off-light.

  Thereby, the heat from the metal housing plate 21a due to the off-light is not transmitted to the DMD element 41, and the temperature rise of the DMD element can be suppressed. Further, for example, heat-resistant black coating is applied to the region irradiated with the off-light, thereby forming a light absorber and improving heat absorption. The contrast of the projector can be improved and the temperature rise of the metal housing can be suppressed. Note that the outside of the opening 45 is covered with the heat radiating portion 55, thereby preventing entry of dust and the like into the inside.

  Next, a cooling structure in a DLP projector according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a diagram illustrating an external configuration example of an optical unit having the light source unit 1 and the lens unit 3 in the cooling structure of the DLP projector according to the present embodiment. In the structure shown in FIG. 3, a lens unit portion 3 including a projection lens 31 and an optical system 11 and a light source unit 1 provided adjacent thereto are arranged. A DMD element is disposed on the back surface of the optical system 11, and a heat sink 12 is provided on the back surface. Further, a fan 15 is provided on the back surface of the light source unit 1, and an air passage L5 directed to the front surface is formed.

  The on-light L1 emitted from the light source unit 1 through the DMD element is projected through a projection lens 31 onto a screen or the like. On the other hand, the off-light L3 is irradiated to an opening not shown in FIG. 3 formed in the metal casing 21, and the heat insulating material 23 also shown in FIG. And the metal plate 25 of the outer side is provided.

  4A and 4B are enlarged views of a lens unit portion of the optical unit portion shown in FIG. 4A and 4B, the region having the off-light irradiation region is referred to as an upper region for convenience. Inside the metal casing 21, a DMD element 41 is provided in a region facing the lens barrel 31 a of the projection lens 31, and a space is formed by the metal casing 21 therebetween.

  The upper part of this space part is opened, and the second opening part by the metal housing 21 is formed. The first lid portion 23 made of plastic, which is the first lid portion, is placed on the housing 21 by, for example, screwing so as to cover the second opening portion by placing it on the upper end of the second opening portion. It is provided so as to be detachable. The first lid 23 is provided with a first opening 23b in a region corresponding to the off-light irradiation region. The first opening 23b is formed in a recess 23a formed in the first lid. Furthermore, a second lid 25 covers the first lid 23 so as to cover an area including the concave portion 23a and the first opening 23b (also serving as a window through which off light passes). And detachable.

  More specifically, the 2nd cover part 25 has a screw hole for fixing with the 1st cover part and the screw | thread 25a. Furthermore, the 2nd cover part 25 has the bending part 25b bent toward the downward direction. The front end portion 25c of the bent portion is configured to come into contact with a region of the metal casing 21 that is out of the space portion. The second lid portion 25 is formed of a metal having good thermal conductivity, such as aluminum, and has a function as a heat sink when irradiated with off-light. The second lid portion 25 corresponds to the off-light radiating portion in FIG. 2 and its back side (inside space side) is preferably covered with black resin or the like.

  As shown in FIG. 4B, there is an advantage that the size of the window formed by the first opening 23b does not have to be increased by lowering the first opening. In addition, by providing the first lid portion 23 made of plastic and the second lid portion 25 made of metal as described above, the space portion holding the DMD 41 is hermetically sealed so that dust and the like can enter the interior. Can be prevented. Further, by forming the second lid portion 25 with a metal such as Al or Mg, it can function as a heat sink for off light.

Further, by arranging the second lid portion 25 and the metal casing 21 so as to be separated from each other by the plastic first lid section 23, even if heat is increased by the heat sink, the heat is directly applied to the metal casing. 21 is not transmitted to the DMD element 41 via 21, there is an advantage that the adverse effect on the DMD element due to the off-light can be reduced. Further, as shown in FIG. 3, by setting the air path L5 from the fan near the second lid portion 25, there is an advantage that the heat dissipation effect can be further enhanced.
Moreover, light absorption can be improved by performing heat-resistant black coating on the surface irradiated with off-light.

  Moreover, light absorption can be improved by performing heat-resistant black coating on the surface irradiated with off-light. Then, the reflection here can be suppressed as much as possible, and unnecessary reflection of the OFF light (= unnecessary light in terms of optical performance) inside the metal casing can be reduced. Temperature rise can be suppressed. Furthermore, the reduction of reflection of unnecessary light inside the metal casing means that unnecessary light is less likely to be taken into the projection lens, and thus has an advantage that the contrast value increases.

  By using a screw to fasten together to the metal casing, it is possible to eliminate metallic floating parts and to ground. Therefore, unnecessary radiation can be reduced. With regard to heat conduction according to the present embodiment, the amount of heat that moves through the screw to the metal housing is almost negligible. As shown in FIG. 1, the cooling efficiency may be improved by forming a metal plate into a fin shape. In this case, as shown in FIG. 4B, since the second lid portion 25a is formed in a step-down manner, there is an advantage in that even if fins are provided in this portion, there is no hindrance as a whole.

(Summary)
1) Since heat generated by the off-light is not transmitted to the DMD element, there is an advantage that the temperature rise of the DMD element can be suppressed.
2) Since the size of the radiating fin for cooling the DMD element can be reduced, the apparatus can be downsized.
3) Since the voltage of the fan for cooling the DMD element can be lowered, there is an advantage that the apparatus can be quieted.

  In this embodiment, the example applied to the DLP projector has been described, but it goes without saying that the present invention can be used for various electronic devices in which the temperature rise affects the main elements.

  The present invention is applicable to electronic devices such as DLP projectors.

1 is a diagram illustrating an example of the overall configuration of a DLP projector used in a first embodiment of the present invention. It is a principle diagram of a cooling structure in a DLP projector according to the present embodiment. It is a figure which shows the external appearance structural example of the optical unit part which has a light source unit part and a lens unit part among the cooling structures in the projector of the DLP system by the 2nd Embodiment of this invention. It is drawing which expanded the part of the lens unit among the optical unit parts shown in FIG. FIG. 4 is an enlarged view of a lens unit portion of the optical unit portion shown in FIG. 3, corresponding to FIG. 4A and showing a part of the inside. It is a figure which shows the example of the conventional general cooling structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... Housing | casing, 31 ... Projection lens, 31a ... Lens barrel, L ... Incident light, 41 ... DMD element, L3 ... Off light, 45 ... Opening part, 53 ... Thermal insulation material board, 55 ... Off light thermal radiation part.

Claims (7)

An electronic device having a metal casing and an element attached in the metal casing,
A first opening that opens a part of the metal housing is provided in an unnecessary heat generation region where unnecessary heat is generated from the element, and a heat insulating material is provided in a region that avoids the opening in the vicinity of the opening. A cooling structure for an electronic device, wherein the heat sink is disposed in a region including the first opening. A DLP projector having a metal casing and a DMD element mounted in the metal casing,
A first opening that opens a part of the metal casing is provided in an unnecessary heat generation region irradiated with off-light emitted from the DMD element, and the first opening in the vicinity of the first opening is provided. A cooling structure for a DLP projector, wherein a heat insulating material is disposed in a region avoiding the portion, and a heat radiating plate is disposed separately from the metal casing in a region including the first opening.   The cooling structure for a DLP projector according to claim 2, wherein an absorber for absorbing the off-light is provided in the first opening. A DLP projector having a metal casing and a DMD element mounted in the metal casing,
A first opening that opens a part of the metal casing is provided in an unnecessary heat generation region irradiated with off-light emitted from the DMD element, and the first opening near the first opening is provided. A first lid in which a region avoiding the opening is formed of a heat insulating material;
A cooling structure for a DLP projector, comprising: a metal second lid portion attached to the first lid portion and provided in a region covering the first opening portion.   The cooling structure for a DLP projector according to claim 4, wherein the first opening is provided in a recess formed in the first lid.   6. The device according to claim 2, wherein the first opening and the second lid or the first opening and the heat radiating plate are in contact with each other. 6. Cooling structure for DLP projectors.   The cooling structure for a DLP projector according to claim 2, further comprising a fan having an air passage in the vicinity of the first opening.

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