JPH0522934Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a light source device for obtaining parallel light for illumination.

[Prior art and its problems] Light source devices such as liquid crystal projectors that project light from a light source onto a liquid crystal display panel to enlarge and project an image displayed on the liquid crystal display panel onto a screen are designed to Since a function for illuminating with illuminance is required, the configuration is such that parallel light for illumination can be obtained. Generally, as shown in FIG. 3, it is comprised of a light emitting body 100 such as a xenon lamp or a halogen lamp with high luminance, and a reflector 102 forming a cold mirror on a paraboloid 101. The reflector 102 is disposed behind the light emitter 100, and reflects the light a emitted by the light emitter 100 on the paraboloid 101 to obtain parallel light b heading forward.

However, in such a conventional light source device, the point light source P of the light emitting part 103 of the light emitter 100
The light a that is emitted from the light source and diffused from the light emitting glass 104 does not necessarily reflect the entire area of the light emitting glass 104 on the paraboloid 101 of the reflector 102 as shown in FIG. 3, and cannot become parallel light b. As shown in the figure, this parallel light b can only be the light a that is diffused from the light emitting glass 104 toward the paraboloid 101 of the reflector 102, and as shown in FIG. The light a′ that diffuses radially forward from the paraboloid 1 of the reflector 102
Instead of being reflected by 01, it was just being diffused. For this reason, the light a' emitted from the front part of the light emitting glass 104 is not effectively used as illumination light. Therefore, the efficiency of using the light from the light emitting body 100 as illumination light is low, and this is also the reason why the amount of light (illuminance) for illuminating the liquid crystal display panel is insufficient in the case of the light source device of the liquid crystal projector. I was getting used to it. Also, reflector 1
The light that is not reflected by the paraboloid 101 of 02 and is diffused as it is is irradiated into the inside of the main body of the liquid crystal projector. However, since light source devices generate a considerable amount of heat, liquid crystal projectors have a parabolic opening in the main body of the device, which causes a problem in that light leaks into the surrounding area.

[Purpose of the invention] This invention was made in view of the above-mentioned circumstances, and its purpose is to make it possible to use the light emitted from the luminous body efficiently as illumination light without wasting it, and to To provide a light source device which reduces unnecessary light emission from a light emitting body and prevents problems from occurring.

[Summary of the invention] In order to achieve the above object, this invention is more sufficient than the above-mentioned light-emitting body, which is placed behind the light-emitting body and reflects the light emitted by the light-emitting body to produce parallel illumination light directed forward. further comprising a deep reflector in the light-emitting part of the light-emitting body, a part of the light-emitting part glass of the light-emitting body in which the emitted light transmitted through the light-emitting part glass does not directly enter the reflector is spherical, and a mirror surface that reflects the incident light to the reflector. The light source device is characterized in that it has a second reflector that prevents unnecessary light from exiting the light source device.

[Embodiment] An embodiment in which this invention is applied to a light source device for a liquid crystal projector will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows a light source device according to this invention, and FIG. 2 shows a liquid crystal projector equipped with this light source device.

A light source device 1 includes a discharge lamp 2 as a light emitter.
The discharge lamp 2 consists of a reflector 4 having a paraboloid 3 that reflects emitted light forward as parallel illumination light. The discharge lamp 2 used here is a short arc type xenon lamp that utilizes discharge in xenon gas, and is attached to the reflector 4 by inserting its base 5 into a support tube 6 at the center of the reflector 4 placed at the rear. It is being The counter electrode of the xenon lamp (anode 7
and cathode 8) sealed quartz bulb (light emitting glass)
Numeral 9 has a spherical shape, and a mirror surface 10 formed by mirror coating is provided at the front center of the inner surface of the spherical quartz bulb 9 (around the cathode 8). Mirror surface 10
The light diffused from the quartz bulb 9 is radially diffused forward from the front of the quartz bulb 9 and is not reflected by the paraboloid 3 of the reflector 4, but is reflected toward the paraboloid 3. For this reason, the mirror surface 10
has an area that faces all the light that is radially diffused forward from the front part of the quartz bulb 9.

In the light source device 1 having such a configuration, the light a' which is trying to be diffused radially forward from the front part of the quartz bulb 9 of the discharge lamp 2 is reflected by the mirror surface 10 toward the paraboloid surface 3 of the reflector 4. Because it is done,
Similar to the light (not shown) diffused from other parts of the quartz bulb 9, it is reflected by the paraboloid 3 of the reflector 4 (light a' reflected by the mirror surface 10 passes through the point light source P' again). (towards the paraboloid 3) and becomes forward parallel illumination light b'. Therefore, in this light source device 1, most of the light emitted from the discharge lamp 2 is used as illumination light, so the light utilization efficiency is extremely high.

Next, an outline of a liquid crystal projector equipped with the light source device 1 will be explained.

This liquid crystal projector has a projection lens 12 on the front of a box-shaped projector main body 11.
Inside, a condensing Fresnel lens 13, a liquid crystal display panel 14, a liquid crystal cooler 15, a transparent plate 16, and a light source device 1 are provided in order from the front, and a blower fan 17 is provided in the center of the upper part.

The projection lens 12 is for projecting the display image of the liquid crystal display panel 14 onto a screen surface (not shown), and is provided in a lens barrel 19 that is screwed into a barrel 18 that is fixed through the front surface of the projector main body 11. By turning the lens barrel 19, the focus can be adjusted according to the position of the screen on which the projected image is formed.

The condensing Fresnel lens 13 is connected to the liquid crystal display panel 14
This is a circular Fresnel lens in which a large number of annular convex lens parts are formed concentrically on one side of a transparent plate made of acrylic resin or the like over the entire surface of the transparent plate. , is held in a plate-shaped holding frame 20 vertically provided within the projector main body 11.

The liquid crystal display panel 14 is, for example, a transmissive dot matrix liquid crystal display panel for displaying television images, and is attached to the front surface of the liquid crystal cooler 15 to face the projection lens 12.

The liquid crystal cooler 15 is used to cool the liquid crystal display panel 14, which is heated due to temperature rise in the projector main body 11, so that the liquid crystal material in the liquid crystal display panel 14 is not affected by heat. A liquid refrigerant 24 such as an aqueous ethylene glycol solution is stored inside a closed container 23 whose front and rear walls are made of transparent plates 21 and 22 made of glass or the like. It is constructed by attaching a heat pipe 25 that exchanges heat with A, and a transparent plate 21 on the front side.
The liquid crystal display panel 14 is superimposed on the outer surface of the display panel and fixed by adhesive. Such a liquid crystal cooler 15
is the liquid crystal display panel 1 heated by the liquid refrigerant 24.
The heat pipe 25 absorbs and radiates heat from the liquid refrigerant 24, which is heated by the liquid refrigerant 24.

The transparent plate 16 is for absorbing infrared components contained in the illumination light from the light source device 1, and is made of an infrared absorption filter or heat-resistant glass, and is installed vertically within the projector body 11. It is fixed to an opening 27 formed in the center of a holding frame 26 having a shape such that the opening 27 is closed.

In the light source device 1, the reflector 4 is fitted and supported by a cylindrical holding frame 28 installed in the projector main body 11.

The blower fan 17 is for circulating outside air A into the projector body 11, and is connected to the shroud 2 provided at the upper center of the projector body 11.
The outside air A is taken in from the slit-shaped intake holes 30 and 31 formed on the front and rear surfaces of the projector main body 11 by its rotational drive, and flows inside the projector main body 11 in the direction of the arrow. The air flows like this and is discharged to the outside through a slit-shaped exhaust hole 32 formed at the upper center of the projector body 11. In this way, while the outside air A flows through the projector main body 11, the outside air A cools each component such as the light source device 1 inside the projector main body 11, and also exchanges heat with the heat pipe 25 of the liquid crystal cooler 15. LCD display panel 1
Cool 4.

In the liquid crystal projector configured in this way, when the discharge lamp 2 of the light source device 1 is turned on and a television image or the like is displayed on the liquid crystal display panel 14, the image is reflected by the paraboloid 3 of the reflector 4 as shown in the figure. The illumination light from the discharge lamp 2 thus directed toward the liquid crystal display panel 14 is parallel to an optical axis O connecting the center of the liquid crystal display panel 14 and the center of a screen (not shown).
The illumination light from the discharge lamp 2 reflected by the paraboloid 3 of the reflector 4 first passes through the transparent plate 16 and has its infrared component absorbed, and then passes through the liquid crystal cooler 15 and displays the liquid crystal. Display panel 14
illuminate from the back side. The light passing through this liquid crystal display panel 14, that is, the liquid crystal display panel 14
The light image corresponding to the displayed image is the condensing Fresnel lens 1
3, the light is focused on the projection lens 12, magnified by the projection lens 12, and projected onto the screen surface. In this case, the light source device 1 for illuminating the liquid crystal display panel 14 has a light intensity that appropriately illuminates the liquid crystal display panel 14 because the light emitted from the discharge lamp 2 is used as illumination light without waste as described above. There is.

The light source device of this invention is not limited to the light source device for illuminating the liquid crystal display panel of the liquid crystal projector shown in the embodiment, but can be widely applied to other light source devices for illumination.

Further, in the embodiment, a xenon lamp, which is a discharge lamp, is used as the light emitting body, but it is also possible to change this to a halogen lamp or the like.

[Effects of the invention] As explained above, the light source device of an electronic device having a heat dissipation port, which uses the light from the light source according to this invention to illuminate a predetermined illuminated part to display a display, has the following effects:
a reflector that is sufficiently deep compared to the light emitting body, the reflector being disposed behind the light emitting body to reflect the light emitted by the light emitting body to produce parallel illumination light directed forward; , the part where the emitted light that has passed through the light emitting glass does not directly enter the reflector is made spherical, and a second reflector having a mirror surface that reflects the incident light to the reflector is used to direct unnecessary light to the outside of the light source device. Therefore, the light from the light source can be irradiated onto the illuminated part without waste, and at the same time, it is possible to provide a compact light source device that is less likely to cause problems due to light leaking from the heat dissipation port of the device body.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a light source device according to an embodiment of this invention, FIG. 2 is a sectional view of a liquid crystal projector equipped with the light source device of this invention, and FIGS. 3 and 4 respectively show conventional light source devices. FIG. 1...Light source device, 2...Discharge lamp (light emitter),
3... Paraboloid, 4... Reflector, 9... Quartz bulb (light emitting part glass), 10... Mirror surface.

Claims (1)

[Scope of Claim for Utility Model Registration] A light source device for an electronic device having a heat dissipation port that illuminates a predetermined illuminated part using light from a light source to display a display, comprising: a light emitting body; and the light emitting body. a reflector that is sufficiently deep relative to the light emitting body to reflect the light emitted by the light emitting body to produce parallel illumination light directed forward; A second part having a spherical shape in which the emitted light transmitted through the light emitting part glass does not directly enter the reflector, and having a mirror surface that reflects the incident light to the reflector.
What is claimed is: 1. A light source device characterized in that a reflector is used to prevent unnecessary light from exiting the light source device.