JP4516730B2 - Liquid crystal panel heat dissipation mechanism for liquid crystal projectors - Google Patents

Description

  The present invention relates to a liquid crystal projector, and more particularly to an improvement in a liquid crystal panel heat dissipation mechanism that prevents overheating of a liquid crystal panel.

  A liquid crystal projector is generally equipped with three liquid crystal panels (LCOS panel and DLP panel) for modulating each color light as light valves. The light emitted from the light source unit is separated into light of each color and then modulated by each liquid crystal panel according to the video signal. Each color light after modulation is combined as a projection light image through a light combining prism such as a dichroic prism, and this is projected on a screen by a projection lens.

  In the liquid crystal projector having this configuration, if the heat generated from the liquid crystal panel is not efficiently released to the outside of the housing, the liquid crystal panel falls into an overheated state, and its optical characteristics are deteriorated to deteriorate the quality of the projected image. appear. For this reason, a liquid crystal panel heat dissipation mechanism for releasing the heat generated there to the outside of the housing is attached to the liquid crystal panel.

  One of the applicants in the specification and drawing of Japanese Patent Application No. 2003-18917 previously formed a support member for supporting the liquid crystal panel from a heat transfer material, and the support member (panel heat transfer material) has a housing. A heat dissipating mechanism having a structure in which a heat dissipating member (panel heat sink) having a heat dissipating surface exposed to the outside is closely bonded is proposed. According to the heat dissipation mechanism of this configuration, heat generated in the liquid crystal panel is efficiently transmitted from the support member to the heat dissipation member, and further efficiently released from the heat dissipation member having a heat dissipation surface exposed outside the housing. Is done. Therefore, the liquid crystal panel can be reliably prevented from falling into an overheated state.

  Here, as the support member, a highly rigid heat conductive metal plate is used for attaching and fixing the liquid crystal panel, such as aluminum and copper. The heat dissipating member is also made of a heavy metal rigid body to ensure a sufficient heat capacity. Further, the support member is firmly fixed to the heat radiating member by screwing or the like in order to ensure heat transfer with the heat radiating member.

  As described above, when a highly rigid support member is firmly and firmly fixed to the highly rigid heat dissipation member by screwing or the like, the stress generated in the support member at the time of joining is a liquid crystal panel attached to the support member. The liquid crystal panel may be distorted. In addition, if unnecessary stress is generated in the support member due to the weight of the heat dissipation member that is closely fixed to the support member, this is transmitted to the liquid crystal panel, which also causes unnecessary distortion in the liquid crystal panel. In addition, if vibration or impact force is applied to the heat dissipation member during product transportation, the heat dissipation member moves, and the support member that is closely fixed to the heat dissipation member is also displaced. As a result, the heat dissipation member is attached to the support member. In some cases, the liquid crystal panel is displaced, for example, tilted.

  If the liquid crystal panel is distorted or misaligned, the convergence adjustment of the liquid crystal panel is shifted, which may adversely affect the projected image.

  SUMMARY OF THE INVENTION An object of the present invention is to propose a liquid crystal panel heat dissipation mechanism for a liquid crystal projector that does not cause distortion or displacement in the liquid crystal panel at the time of assembly or product transportation, and has excellent heat dissipation performance. .

A liquid crystal panel heat dissipation mechanism for a liquid crystal projector according to the present invention includes an opening formed in a bottom plate portion of a housing of the liquid crystal projector, and a panel heat sink that is fixed to the outside of the bottom plate portion of the housing and seals the opening. A panel heat transfer material provided with a vertical plate portion to which a liquid crystal panel is attached and a horizontal plate portion bent at a right angle from the lower end of the vertical plate portion, and the opening exposed to the inside of the housing A flexible heat transfer material is provided between the upper surface portion of the panel heat sink and the horizontal plate portion of the panel heat transfer material .

  Heat generated in the liquid crystal panel is transferred from the panel heat transfer material to the panel heat sink via the flexible heat transfer material, and is released from the panel heat sink to the outside of the casing. In addition, the panel heat transfer material to which the liquid crystal panel is attached is attached to the flexible heat transfer material. Unlike the case of fixing directly to the panel, unnecessary stress is not generated in the panel heat transfer material. Therefore, there is no adverse effect such as distortion caused by the stress acting on the liquid crystal panel attached to the panel heat transfer material. Further, since the heavy panel heat sink is fixed to the casing, the weight does not act on the liquid crystal panel side via the panel heat transfer material. Furthermore, since the panel heat sink attached to the housing and the panel heat transfer material are connected by a flexible heat transfer material, vibration and impact force acting on the panel heat sink side are absorbed by the flexible heat transfer material. It is not transmitted to the liquid crystal panel via the panel heat transfer material.

  Here, as the flexible heat transfer material, a carbon graphite sheet having a structure in which carbon sheets are laminated and bonded, or a copper foil can be used.

  The panel heat sink preferably includes a heat radiating surface exposed to the outside from the housing.

In the present invention, a concave portion having a predetermined depth is formed in the upper surface portion of the panel heat sink, and the horizontal plate portion of the panel heat transfer material is disposed in the concave portion so as to be at the same height position as the upper surface portion. The flexible heat transfer material can be horizontally bridged between the upper surface portion and the horizontal plate portion .

  Next, the present invention relates to a liquid crystal projector, and is characterized by having a liquid crystal panel heat dissipation mechanism having the above-described configuration.

  In the liquid crystal panel heat dissipation mechanism of the liquid crystal projector of the present invention, the panel heat transfer material to which the liquid crystal panel is attached is connected to the panel heat sink fixed to the housing via the flexible heat transfer material. Therefore, unlike the case where the rigid panel heat transfer material and the rigid and heavy panel heat sink are directly tightly joined, unnecessary stress is not applied to the panel heat transfer material during assembly. No vibration or impact force acts on the panel heat transfer material from the heat sink side. Therefore, undesired stress, vibration and impact force do not act on the liquid crystal panel attached to the panel heat transfer material. As a result, it is possible to avoid problems such as distortion and tilt in the liquid crystal panel itself, deviation in convergence adjustment, and deterioration in the image quality of the projected image.

  Embodiments of a liquid crystal projector to which the present invention is applied will be described below with reference to the drawings. FIG. 1 is a plan view showing the internal structure of the liquid crystal projector according to the present embodiment, and FIG. 2 is a schematic sectional view taken along the line II-II in FIG.

(overall structure)
As shown in these drawings, the liquid crystal projector 1 has a housing 2 made of aluminum. The housing 2 has a flat rectangular shape that is long and flat, including front and rear end plate portions 21 and 22, left and right side plate portions 23 and 24, a top plate portion 25, and a bottom plate portion 26. In addition, a ceramic material is applied to the surface of the housing 2 in order to improve heat dissipation from the housing 2.

  The interior of the housing 2 is divided into left and right by a vertical heat insulating wall 3 that extends perpendicularly from a middle position in the left-right direction of the front end plate portion 21 and reaches the rear end plate portion 22. The compartment 4 and the second compartment 5 are formed. The heat insulating wall 3 is a vertical wall extending from the bottom plate portion 26 of the housing 2 to the top plate portion 25. The first compartment 4 is partitioned by a heat insulating wall 6 into a light source side compartment 7 and a power source side compartment 8. The heat insulation wall 6 is bent at a right angle from the front end of the wall portion 61 to the rear side from a wall portion 61 extending in the longitudinal direction of the housing from the middle position in the front-rear direction of one side plate portion 24 of the housing 2. And a wall portion 62 extending to the rear end wall portion 22. The heat insulating wall 6 is also a vertical wall from the bottom plate portion 26 of the housing 2 to the top plate portion 25.

  The power supply side compartment 8 partitioned in an L shape by the heat insulating wall 6 includes a partition part 81 extending leftward and rightward on the front side, and a partition part 82 extending rearward from the rear side. A power supply unit 53 including a ballast circuit 51 and a power supply circuit 52 is disposed at 81. The rear compartment 82 functions as a heat insulating space interposed between the light source compartment 7 and the second compartment 5.

  A light source unit 10 is disposed in the light source side compartment 7 partitioned into a rectangle by the heat insulating wall 6. The light source unit 10 includes a light source lamp 13 including a discharge tube 11 and a reflector 12, and a lamp mounting frame 14 that supports the light source lamp 13. The optical axis 13a of the light source lamp 13 is directed in the width direction of the housing 2, and an opening 62a is formed in the wall portion 62 of the heat insulating wall 6 facing the emission side.

  A cylindrical optical chassis 15 is coaxially attached to the outer peripheral edge portion of the opening 62a. The optical chassis 15 is a plastic molded product, and has a large-diameter cylindrical portion 15a joined to the outer peripheral edge portion of the opening 62a, and a small-diameter cylindrical portion 15b that is coaxially continuous with the tip of the cylindrical portion 15a. It has. The tip edge of the small-diameter cylindrical portion 15 b is coaxially connected to a circular opening 3 a having the same inner diameter formed in the heat insulating wall 3. An optical chassis 16 made of a plastic molded product having one end connected to the circular opening 3a is also arranged on the second compartment 5 side.

  A heat sink mounting portion 27 for attaching a panel heat sink 45 constituting a panel heat radiating mechanism 50 described later is formed in a portion of the bottom plate portion 26 of the housing 2 below the optical chassis 16. The heat sink mounting portion 27 is a rectangular recess that is recessed from the bottom plate portion 26 of the housing 2 to the inside of the housing. It has a depth of about 2/3 of the height including 45c. The upper surface 27a of the heat sink mounting portion 27 has an opening 26d at the center portion, leaving a rectangular frame portion 26c with which the peripheral edge of the upper surface 45a of the panel heat sink 45 abuts when the panel heat sink 45 is mounted. The four corners of the upper surface 45a of the panel heat sink 45 are screwed and fixed to the rectangular frame portion 26c of the heat sink mounting portion 27 of the housing 2 formed in this way.

(Optical system)
Next, an optical system incorporated in the optical chassis 15 will be described. A uniform illumination optical system 17 for converting the light emitted from the light source lamp 13 into a parallel light flux having a uniform luminance distribution is disposed inside the optical chassis 15 disposed in the power supply side compartment 8. The uniform illumination optical system 17 includes an integrator lens 18 and a condenser lens 19 in which a plurality of microlenses are arranged in a matrix.

  On the other hand, inside the optical chassis 16 in the second compartment 5, there are a color separation optical system 30, three liquid crystal panels 31, 32, 33 that function as light valves, and a light combining optical system 34. Is arranged. In the color separation optical system 30, a blue light component is separated from a parallel light beam incident through the circular opening 3 a by a blue reflecting dichroic mirror 35, and is applied to a liquid crystal panel 31 through a total reflection mirror 36 and a condenser lens 37. Lead. The green light component that has passed through the blue reflecting dichroic mirror 35 is reflected by the green reflecting dichroic prism 38 and guided to the liquid crystal panel 32 through the condenser lens 39. Further, the red light component that has passed through the green reflecting dichroic prism 38 is guided to the liquid crystal panel 33 via a relay optical system including a pair of relay lenses 40 and 41 and total reflection mirrors 42 and 43 and a condenser lens 44. .

  Each color light component separated by the color separation optical system 30 is modulated by the liquid crystal panels 31, 32, and 33 in accordance with the video signal and guided to the light combining prism 34. The light combining prism 34 has a structure in which four dichroic prisms are bonded to each other, and the modulated color light components are combined through a reflecting surface made of an X-shaped dielectric multilayer film to form a projected light image. A single light beam is used. The projected light image is enlarged and projected on a screen (not shown) via a projection lens unit 49 disposed in the front opening 16a of the optical chassis 16. Here, the liquid crystal panels 31, 32, and 33 are attached to the light combining prism 34 in a state in which the convergence is adjusted by UV bonding or soldering.

(Heat dissipation mechanism for light source unit and power supply unit)
The heat dissipation mechanism of the light source unit 10 includes heat sinks 72 and 73 attached to side surfaces 70 and 71 of the lamp mounting frame 14 facing the end plate portion 22 on the rear side of the housing and the left side plate portion 24 of the lamp mounting frame 14. The top surface 74 and the bottom surface 75 of the lamp mounting frame 14 are opposed to each other. The top plate portion 25 and the bottom plate portion 26 of the housing 2 face each other. A large number of radiating fins 78 and 79 are formed on the back surface portions of the heat sinks 72 and 73, and the radiating fins 78 and 79 are opened to the outside of the housing from the openings 22a and 24a formed in the end plate portion 22 and the side plate portion 24. Protrusions are exposed. The heat radiation openings 76 and 77 have a structure in which a large number of openings are formed.

  On the other hand, the heat dissipation mechanism of the power supply unit 53 includes heat sinks 54 and 55 attached to the case of the ballast circuit 51 and the case of the power supply circuit 52, respectively.

(LCD panel heat dissipation mechanism)
The liquid crystal panel heat dissipation mechanism 50 for releasing the heat generated in the liquid crystal panels 31 to 33 to the outside of the housing includes a panel heat transfer material 46 made of a highly heat conductive material supporting the liquid crystal panels 31 to 33, and A flexible heat transfer material 47 having a rectangular plate shape whose one end is connected to the panel heat transfer material 46 and a panel heat sink 45 to which the other end of the flexible heat transfer material 47 is connected are provided. The panel heat sink 45 is attached from the outside of the housing 2 to the heat sink mounting portion 27 formed on the bottom plate portion 26 of the housing 2 as described above.

  The panel heat transfer material 46 is made of an aluminum plate bent into an L shape, and the vertical plate portion 46 a extends into the optical chassis 16 through an opening 16 b formed in the bottom surface of the optical chassis 16. Liquid crystal panels 31 to 33 are vertically attached to the respective vertical plate portions 46a. The horizontal plate portion 46 b of the panel heat transfer material 46 extends in the horizontal direction at a height position protruding downward from the opening 26 d of the heat sink mounting portion 27 by the thickness.

  The flexible heat transfer material 47 is made of a carbon graphite sheet having a thickness of about 0.2 mm in which thin carbon is bonded in a laminated state. The shape of the flexible heat transfer material 47 is substantially square, and one end of the flexible heat transfer material 47 covers and closely covers the entire upper surface 46c of the horizontal plate portion 46b of the panel heat transfer material 46, and is tightly fixed to the upper surface 46c with two screws. Has been. The opposite end of the flexible heat transfer material 47 is also closely fixed to the upper surface 45a of the panel heat sink 45 by two screws.

  A portion surrounded by a rectangular frame-shaped flat upper surface 45 a of the panel heat sink 45 is a recess 45 b where a horizontal plate portion 46 b protruding downward from the opening 26 d of the heat sink mounting portion 27 is located. The depth of the recess 45b is larger than the thickness of the horizontal plate portion 46b so that the lower surface 46e of the horizontal plate portion 46b does not contact the heat sink 45. The lower half of the panel heat sink 45 is a heat radiating surface on which many heat radiating fins 45c are formed.

  In a state where the panel heat sink 45 is attached to the heat sink attachment portion 27, the upper surface 46c of the horizontal plate portion 46b of the panel heat transfer material 46 is located in the recess 45b at a position that is flush with the upper surface 45a of the panel heat sink 45. . For this reason, the work of tightly fixing the flexible heat transfer material 47 extending horizontally from the end face 46d of the horizontal plate portion 46b to the upper surface 45a of the panel heat sink 45 with screws is simple.

  In the liquid crystal panel heat dissipation mechanism 50 configured as described above, the heat generated in the liquid crystal panels 31 to 33 is transmitted from the panel heat transfer material 46 to the outside of the housing 2 via the flexible heat transfer material 47. Is released from here. As a result, the liquid crystal panels 31 to 33 do not fall into an overheated state.

  Further, the panel heat transfer material 46 to which the liquid crystal panels 31 to 33 are attached is connected to the panel heat sink 45 via the flexible heat transfer material 47. Therefore, unlike the case where the highly rigid panel heat transfer material 46 is directly fixed to the same highly rigid panel heat sink 45, unnecessary stress is not generated in the panel heat transfer material 46 when the panel heat transfer material 46 is assembled. . Further, since the panel heat sink 45 is attached to the housing 2, the weight of the panel heat sink 45 does not act on the panel heat transfer material 46. Furthermore, even if vibration or impact is applied to the panel heat sink 45 side, they are absorbed or relaxed by the flexible heat transfer material 47 and are not transmitted to the panel heat transfer material 46 side. Therefore, undesired stress, vibration, and impact do not act on the liquid crystal panels 31 to 33 attached to the panel heat transfer material 46.

(Other embodiments)
The material of the panel heat transfer material 46 is aluminum, but copper can also be used. Also, the flexible heat transfer material 47 can be made of a copper foil having a thickness of about 0.1 mm, instead of the carbon graphite sheet. Of course, other materials can be used as long as the materials have a predetermined flexibility or flexibility and a necessary thermal conductivity.

2 is a plan configuration diagram showing an internal configuration of a liquid crystal projector according to the present embodiment. FIG. It is a schematic sectional drawing at the time of cut | disconnecting along the II-II line | wire of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal projector 2 Cases 3 and 6 Heat insulation wall 4 1st partition room 5 2nd partition room 7 Light source side compartment 8 Power source side compartment 10 Light source unit 11 Discharge tube 12 Reflector 13 Light source lamp 14 Lamp attachment frame 15, 16 Optical chassis 17 Uniform illumination optical system 27 Heat sink mounting part 30 Light separation optical system 31, 32, 33 Liquid crystal panel 34 Photosynthesis prism 49 Projection lens unit 45 Panel heat sink 45b Recess 46 Panel heat transfer material 47 Flexible heat transfer material 50 Liquid crystal panel Radiation mechanism 54, 55, 72, 73 Heat sink 78, 79 Radiation fin 76, 77 Opening

Claims (5)

An opening formed in the bottom plate portion of the housing of the liquid crystal projector;
A panel heat sink fixed to the outside of the bottom plate portion of the housing and sealing the opening;
A panel heat transfer material comprising a vertical plate portion to which a liquid crystal panel is attached and a horizontal plate portion bent at a right angle from the lower end of the vertical plate portion;
A liquid crystal having a flexible heat transfer material bridged between the upper surface portion of the panel heat sink exposed from the opening to the inside of the housing and the horizontal plate portion of the panel heat transfer material. Projector LCD panel heat dissipation mechanism. In claim 1,
The flexible heat transfer material is a liquid crystal panel heat dissipation mechanism of a liquid crystal projector, which is a carbon graphite sheet having a structure in which carbon sheets are laminated and bonded, or a copper foil. In claim 1 or 2,
The panel heat sink is a liquid crystal panel heat dissipation mechanism of a liquid crystal projector provided with a heat dissipation surface exposed to the outside from the housing. In any one of claims 1 to 3,
A concave portion having a predetermined depth is formed in the upper surface portion of the panel heat sink,
In the recess, the horizontal plate portion of the panel heat transfer material is arranged to be at the same height position as the upper surface portion,
A liquid crystal panel heat dissipation mechanism for a liquid crystal projector, wherein the flexible heat transfer material is stretched horizontally between the upper surface portion and the horizontal plate portion . A liquid crystal projector comprising the liquid crystal panel heat dissipation mechanism according to claim 1.

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