JPH0438349Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a light source device provided in a projector.

[Conventional technology]

A light source device installed in a projector such as a projector consists of a light source lamp and a reflector that reflects the illumination light from the light source lamp toward the front. In a liquid crystal projector, image light is incident on a liquid crystal display panel (liquid crystal display panel) or an original film, and transmitted through the display panel or original film, and is magnified by a projection lens and projected onto a screen surface or the like.

By the way, as the light source lamp of the light source device installed in the above-mentioned projector, a high voltage arc lamp such as a xenon lamp with high emission brightness is generally used, but this high voltage arc lamp has a high luminance due to arc discharge between the electrodes. Because it emits light, electromagnetic waves are emitted from the lamp due to arc discharge,
There is a problem in that it has an adverse effect on the electronic circuit within the projector (the display drive circuit of the liquid crystal display panel in a liquid crystal projector, etc.).

For this reason, it has been conventionally considered to house the light source lamp and the reflector in a metal housing and use the housing to shield electromagnetic waves from the light source arc lamp.

[Problem that the invention attempts to solve]

However, in the conventional light source device, the front surface of the housing is opened so as not to block the illumination light reflected by the reflector.
Electromagnetic waves were radiated into the projector from this opening, and the electronic circuits inside the projector were affected by the electromagnetic waves, causing malfunctions.

This idea was created in view of the above-mentioned circumstances, and its purpose is to shield the electromagnetic waves generated by the light source lamp on the illumination light output side of the front of the housing so that the electronic circuit inside the projector can be protected. It is an object of the present invention to provide a light source device that eliminates the fear of malfunction due to the influence of electromagnetic waves.

[Means to solve problems]

This idea uses a metal member to shield the rear of the reflector from electromagnetic waves, as well as a metal member on the front of the reflector.
The present invention is characterized in that a mesh-shaped electromagnetic shielding member is provided, which is made of conductive ultra-thin metal foil with a predetermined width, and the foil surface of the metal foil is parallel to the direction of the light reflected by the reflector.

[Effect]

That is, the light source device of this invention shields the rear of the reflector from electromagnetic waves with a housing made of a metal member, and the front side of the reflector is made of a conductive ultra-thin metal foil of a predetermined width, and the foil surface of the metal foil is covered with the reflector. Since the mesh-shaped electromagnetic wave shielding member is provided parallel to the direction of the reflected light, this light source device shields the electromagnetic waves generated by the light source lamp even on the illumination light output side in front of the reflector. , it is possible to eliminate the fear that the electronic circuit inside the projector will malfunction due to being affected by electromagnetic waves. Moreover, in this idea,
The electromagnetic wave shielding member is made of a mesh-like material made of conductive ultra-thin metal foil, and since the foil surface of this metal foil is parallel to the direction of the light reflected by the reflector, the electromagnetic wave shield is also provided in front of the reflector. Even though it is equipped with The electromagnetic wave shielding effect of the shielding member can be sufficiently enhanced.

〔Example〕

An embodiment of this invention will be described below with reference to the drawings, taking a light source device in a liquid crystal projector as an example.

First, let me explain the configuration of an LCD projector.
In FIGS. 1 and 2, 10 is a projector main body, and a projection lens 20 is provided on the front surface of this projector main body 10. As shown in FIG. The projection lens 20 is provided in a lens barrel 22 that is screwed onto a barrel 21 that is fixed to the front surface of the projector main body 10. By rotating the lens barrel 22, a projected image is formed on a screen (see FIG. The focus is adjusted according to the position of the camera (not shown). 3
Reference numeral 0 denotes a transmissive dot matrix liquid crystal display panel for displaying a television image, which is vertically provided on the front side of the projector main body 10 and facing the projection lens. It is attached to a display panel cooling body 31 which is vertically provided therein and has a configuration that will be described later. Further, 40 is a condensing Fresnel lens arranged between the liquid crystal display panel 30 and the projection lens 20. The condensing Fresnel lens 40 condenses the displayed image of the liquid crystal display panel 30 onto the projection lens 20. The condensing Fresnel lens 40 is a circular Fresnel lens in which the convex lens portion is formed concentrically.
It is held by a lens holding frame 11 provided inside.
Reference numeral 50 denotes a light source device provided on the rear side inside the projector main body 10, and the illumination light from this light source device 50 passes through the display panel cooling body 31 and enters the liquid crystal display panel 30 from the back surface side. Light transmitted through the panel 30, that is, the liquid crystal display panel 3
The display image of 0 is condensed onto a projection lens 20 by a condensing Fresnel lens 40, and is enlarged and projected onto a screen surface by this projection lens 20.

The display panel cooling body 31 is for cooling the liquid crystal display panel 30, which is heated by the temperature rising inside the projector body 10 due to radiant heat from the light source device 50.
Transparent plates 33 made of glass or the like are attached to both sides of a vertical frame 32 having a sufficiently larger outer shape than the liquid crystal display panel 30.
A transparent cooling medium 35 such as an ethylene glycol aqueous solution is filled in a cooling container with an airtight structure closed by a cooling container 34. and fixed by adhesive or other means.
Further, 36 is a cooling pipe provided on the display panel cooling body 31, avoiding a portion corresponding to the liquid crystal display panel 30, and this cooling pipe 36 is
It is inserted into the upper part of the cooling container with both ends protruding outward from both side surfaces of the cooling container. This cooling pipe 36 is for releasing heat absorbed by the cooling medium 35 in the display panel cooling body 31 to the outside, and the central part of this cooling pipe 36 inserted into the cooling container is used as a heat absorbing part. Both end side portions protruding outside the cooling container are used as heat radiating parts, and each heat radiating part is provided with a plurality of heat radiating fins 37, 37. The heat dissipation fins 37, 37 are large-area fins in the form of vertically long strips, and each of the heat dissipation fins 37, 37 efficiently directs the air flowing inside the projector main body 10 and cooling the liquid crystal display panel 30 in the exhaust direction. The plate surface is aligned in a direction perpendicular to the display surface of the liquid crystal display panel 30 so as to guide the liquid crystal display panel 30, and the plate surface is tilted inward from the lower end to the upper end (towards the center of the display panel cooling body 31). and are arranged parallel to each other. Although the structure of the cooling pipe 36 is not shown, it is similar to a general heat pipe, in which a minute amount of working fluid (heat transfer medium) is sealed inside a metal pipe with both ends closed and the inside evacuated. , this cooling pipe 3
Asbestos-like wicks are formed throughout the inner surface of the pipe 6 to guide the working fluid in the pipe from the heat radiating section to the heat absorbing section by capillary action. The working fluid transfers heat through a reversible two-phase change of evaporation and condensation, and a fluid with a high latent heat coefficient and excellent permeability, such as fluorocarbon, is used as the working fluid. This working fluid is supplied to the display panel cooling body 31 in the heat absorption part of the cooling pipe 36.
It heats up and evaporates due to heat exchange with the cooling medium 35 inside, becomes steam and rises inside the pipe 36, and condenses and changes due to heat radiation to the outside in the heat radiation section, and loses latent heat. The liquefied working fluid permeates through the wick and is led back to the heat absorbing section by capillary action. This cooling pipe 36
In order to guide the working fluid that has evaporated in the heat absorption part to the heat radiation parts at both ends of the pipe, and to guide the working fluid that has liquefied in the heat radiation part and permeated into the pipe to the heat absorption part again, the central part is the lowest and both ends are diagonally upward. It is bent in a shape that slopes towards the front. That is, the display panel cooling body 31 is cooled from the inside by the cooling medium 35 inside the display panel cooling body 31, and the liquid crystal display panel 30 fixed to the display panel cooling body 31 is
The heat absorbed by the cooling medium 35 is radiated to the outside by the heat radiation fins 37, 37 provided in the heat radiation part of the cooling pipe 36, so the temperature of the cooling medium 35 is always low. will be maintained.

In FIG. 1, reference numeral 38 is a main circuit board installed upright on one side of the projector main body 10, and this main circuit board 38 processes television radio waves received by an antenna (not shown). A linear circuit that outputs an image signal and a display drive circuit are configured, and the liquid crystal display panel 30 has a sheet-like flexible connector (not shown) connected to the display drive circuit section of the main circuit board 38.
connected by.

On the other hand, slit-shaped intake holes 12, 12 are provided on the lower edges of the front and rear surfaces and both sides of the projector main body 10, respectively, for taking in outside air into the projector main body 10, and on the upper surface of the projector main body 10, A plurality of slit-shaped exhaust holes 13 are provided in the center of the projector body 10, and a blower fan 1 is located at the upper part of the projector body 10 under the formation of the slit-shaped exhaust holes 13.
4 is installed. This ventilation fan 14 is connected to the projector main body 10 from each of the intake holes 12, 12.
The cooling air taken in from the outside is discharged from the exhaust hole 13, and the cooling air taken into the projector body 10 from the intake holes 12, 12 on the front and both sides of the projector body 10. As shown by arrows in FIG. 2, the water flows through the projector main body 10 to air-cool the condensing Fresnel lens 40, the liquid crystal display panel 30, the main circuit board 38, etc., and also cools the heat radiation fins 37, 37 of the display panel cooling body 31. It exchanges heat with the air and is discharged from the exhaust hole 13. Further, the cooling air taken into the projector main body 10 from the intake hole 12 on the rear surface of the projector main body 10 cools the light source device 50 from the back side thereof.
0 flows to the front of the light source device 50 from between the outer surface of the light source 0 and the partition wall 15 provided inside the projector body 10,
The cooling air is taken in from the intake holes 12 on both sides of the projector body 10 and is discharged from the exhaust hole 13 together with the cooling air that cools the light source device 50 from the front side.

Further, the light source device 50 and the display panel cooling body 3
1, a heat insulating wall 60 partitioning the space is provided vertically and biased toward the display panel cooling body 31 side. This heat insulating wall 60 is provided to suppress heating of the display panel cooler 31 and the liquid crystal display panel 30 due to radiant heat from the light source device 50. An opening 61 for transmitting light is provided, and a transparent plate 62 made of an infrared absorption filter or heat-resistant glass is attached to this opening 61.

Further, 70 is a stand body for supporting the projector body 10 diagonally upward when the liquid crystal projector is placed on a desk or the like, and this stand body 70 is provided on the front end side of the projector body 10. This stand body 70 can be moved up and down via a screw shaft 72 provided vertically inside the projector main body 10 by turning a stand height adjustment operation knob 71 provided on the outer surface of the projector main body 10. The screw shaft 72 is rotated via gears 73 and 74 by rotation of the operating knob 71. Reference numeral 75 denotes a moving member that is screwed onto the screw shaft 72 and is moved up and down by the rotation of the screw shaft 72.
5 is prevented from rotating by a guide plate 76 provided vertically within the projector main body 10, and is configured to move up and down while being guided by this guide plate 76. The stand body 70 also has a leg portion 70b that protrudes below the bottom surface of the projector main body 10 at the lower end of the vertical portion 70a that is parallel to the screw shaft 72.
The leg portion 70b extends horizontally in the width direction of the projector main body 10 so as to stably abut against the projector mounting surface a such as a desk top. . The stand body 70 is fixed to the movable member 75 at the upper end of its vertical portion 70a, and is moved up and down together with the movable member 75 while being guided by a stand body insertion hole 77 provided on the bottom surface of the projector body 10. It is becoming more and more common.

Next, the light source device 50 will be described. This light source device 50 includes a light source lamp 52 and a liquid crystal display for transmitting illumination light from the light source lamp 52 into a housing 51 made of a conductive metal plate with a circular opening formed in the front surface. A reflector 53 is provided to reflect the light toward the front of the housing 51 toward the display panel 30. The reflector 53 is a parabolic mirror that reflects the illumination light from the light source lamp 52 as parallel light parallel to the optical axis O. This reflector 53 is fixed to the light source box 51 by means such as screws. In addition, the light source lamp 52
A high-voltage arc lamp such as a xenon lamp with high luminance is used as the light source lamp 52.The base of the light source lamp 52 is inserted into the neck of the reflector 53, so that the light emitting part (arc generating part) is connected to the reflector 53. It is positioned and supported by the reflector 53 so as to match the focus position of the paraboloid.

Moreover, 54 is an electromagnetic wave shielding member provided on the front surface of the housing 51, and this electromagnetic wave shielding member 54 has a mesh shape with a large aperture ratio. That is, this electromagnetic wave shielding member 54 has a honeycomb core shape (a large number of hexagonal cylinders) as shown in FIG. are continuous vertically and horizontally),
This honeycomb core body 55 is held by an outer frame 56 made of conductive metal, and is attached to the housing 51 with electrical continuity by fixing the outer frame 56 to the front outer circumference of the housing 51. . The honeycomb core body 55 is made by laminating a large number of tape-shaped ultra-thin metal foils of a predetermined width (for example, about 5 mm to 10 mm) and stacking adjacent metal foils together over their entire length, in the same manner as in the well-known paper honeycomb core manufacturing method. The metal foils 55a, 55a are manufactured by adhering them at predetermined intervals over the entire length of the metal foils and stretching them in the direction to separate them. axis O)
is parallel to. Further, the light source lamp 52 is
The anode terminal 52a of the light source lamp 52 is provided with its anode side facing inside the reflector 53.
is inserted into the center of the honeycomb core body 55 and is electrically connected to the honeycomb core body 55 . The anode terminal insertion portion of the honeycomb core body 55 is formed in such a shape that one eye of the honeycomb core body 55 is tightly fitted with the anode terminal 52a. The honeycomb core body 55 is electrically connected to the honeycomb core body 55 by being tightly fitted into the honeycomb core body 55. In addition, the light source lamp 52
The anode terminal 52a of the light source lamp 52 has a high voltage cathode to prevent the inside of the housing 51 from becoming high pressure.
A power supply circuit board 57 for the light source is placed upright on the side of the
The lead wire 5 connects the earth line and the housing 51.
By connecting by 8a, the housing 5
1 and an electromagnetic wave shielding member 54 to the ground line of the power supply circuit board 57 . Note that the cathode terminal 52b protruding from the back side of the reflector 53 of the light source lamp 52 is connected to the power supply circuit board 57 by a lead wire 58b.

The liquid crystal projector has a liquid crystal display panel 30.
The television image displayed by the LCD panel is enlarged and projected onto an external screen surface, and when the light source lamp 52 of the light source device 50 is turned on and the television image is displayed on the liquid crystal display panel 30, the image is displayed on the liquid crystal display panel 30. The projected television image is enlarged and projected onto the screen surface by the projection lens 20.

However, in the above liquid crystal projector,
Since the light source device 50 has a structure in which an electromagnetic wave shielding member 54 is provided on the front surface of the housing 51, the electromagnetic waves generated by the light source lamp 52 are shielded by the housing 51, and the electromagnetic waves emitted from the opening on the front surface of the housing are also shielded from the electromagnetic waves. The light source lamp 52 can be shielded by the member 54, and therefore, according to this light source device, the light source lamp 52
The electromagnetic waves generated by
There is no need to worry about the device malfunctioning due to the influence of electromagnetic waves. Moreover, in the light source device 50, the electromagnetic wave shielding member 54 is made of a mesh-like member made of conductive ultra-thin metal foils 55a, 55a, and the foil surfaces of the metal foils 55a, 55a are reflected by the reflector 53. In order to make it parallel to the direction of light, an electromagnetic wave shielding member 54 is used.
has a very high aperture ratio of approximately 98% (when the thickness of the metal foils 55a, 55a is 25 μm to 75 μm), and therefore a shadow of the electromagnetic shielding member 54 is created in the illumination light reflected by the reflector 53. Therefore, even though the electromagnetic shielding member 54 is provided on the front surface of the housing 51, the light source lamp 52
It is possible to project illumination light with high efficiency into the liquid crystal display panel 43 to project a bright image with high brightness on the screen surface.
Since a has a width along the direction of the light reflected by the reflector 53, the electromagnetic wave shielding effect of the electromagnetic wave shielding member 54 can be made sufficiently high.

In addition, in the above embodiment, the electromagnetic wave shielding member 5
4 has a honeycomb core shape, and this electromagnetic wave shielding member 54 is formed of a conductive ultra-thin metal foil of a predetermined width, and the foil surface of the metal foil is connected to the reflector 5.
As long as it is parallel to the direction of the light reflected by 3, it may be in the form of a grid, for example, and this invention can be widely applied not only to light source devices for liquid crystal projectors but also to light source devices for various projectors. Of course.

[Effect of idea]

The light source device of this invention shields the rear part of the reflector from electromagnetic waves with a metal member, and the front side of the reflector is made of a conductive ultra-thin metal foil of a predetermined width, and the foil surface of the metal foil is used to shield the light reflected by the reflector. Since it is equipped with a mesh-shaped electromagnetic wave shielding member parallel to the direction, the electromagnetic waves generated by the light source lamp are also shielded on the illumination light output side in front of the reflector, so that the electronic circuit inside the projector is not affected by the electromagnetic waves. This eliminates the need to worry about malfunctions occurring. Moreover, according to this invention, the electromagnetic wave shielding member is made of a mesh-like member made of ultra-thin conductive metal foil, and the foil surface of this metal foil is made parallel to the direction of the light reflected by the reflector. Although the electromagnetic wave shield is also provided in front of the reflector, it is possible to maintain high lighting efficiency, and the metal foil forming the electromagnetic wave shield member has a width along the direction of the light reflected by the reflector. Therefore, the electromagnetic shielding effect of the electromagnetic shielding member can be sufficiently increased.

[Brief explanation of the drawing]

1 and 2 are an exploded perspective view and a longitudinal sectional side view of a liquid crystal projector equipped with a light source device showing one embodiment of this invention, and FIG. 3 is an enlarged perspective view of a honeycomb core body of an electromagnetic shielding member. 50...Light source device, 51...Housing, 52
...Light source lamp, 53...Reflector, 54...
Electromagnetic shielding member, 55...honeycomb core body,
55a...Metal foil.

Claims (1)

[Claims for Utility Model Registration] A light source device that houses a light source lamp and a reflector that reflects illumination light from the light source lamp toward the front, wherein the rear of the reflector is shielded from electromagnetic waves with a metal member, and the front of the reflector is shielded from electromagnetic waves by a metal member. A light source device comprising: a mesh-shaped electromagnetic shielding member made of conductive ultra-thin metal foil having a predetermined width, the foil surface of the metal foil being parallel to the direction of the light reflected by the reflector. .