JPH0535390Y2 - - Google Patents

Description

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

[Conventional technology]

The light source device of a projector consists of a light source lamp and a reflector that reflects the light from the light source lamp and projects it forward.The light source lamp is generally a high voltage arc lamp such as a xenon lamp with high luminance. is used.

FIG. 5 shows a conventional light source device, in which numeral 10 is a high-voltage arc lamp, such as a xenon lamp, and 20 is a reflector that reflects the light from the xenon lamp 10 and projects it forward. The xenon lamp 10 emits light by arc discharge between electrodes, and the xenon lamp 10 has an anode electrode 13 and a cathode electrode 1 in a lamp body in which both ends of a glass tube 11 are sealed with tubular caps 12, 12.
4 with their tips facing each other in the glass tube 11, and both the electrodes 1
Terminals 13a and 14a of terminals 3 and 14 protrude from both ends of the lamp body (outer ends of bases 12 and 12). The xenon lamp 10 has its anode side facing the light projection direction, and its cathode side facing the reflector 2.
The cathode side base 12 of this lamp 10 is located at the center of the reflector 20 facing toward the rear of the reflector 20.
1 to the rear of the reflector 20.

This light source device is used, for example, in a liquid crystal projector as shown in FIG. 6, and terminals 13a and 14a at both ends of the lamp 10 are connected to a power source for lighting the lamp by lead wires (not shown). ing.

This liquid crystal projector displays an image using a transmissive liquid crystal display panel, and enlarges and projects the displayed image on the liquid crystal display panel onto a screen surface using a projection lens. In Fig. 6, 30 is the case of the projector. A projection lens 31 formed by combining a plurality of optical lenses is provided on the front surface of the case 30, and a transmissive dot matrix liquid crystal display panel 32 is disposed inside the case 30, facing the projection lens 31. is located. The light source device is installed horizontally at the rear of the case 30 so as to project light toward the liquid crystal display panel 32 from a substantially horizontal direction. The light incident and transmitted through the liquid crystal display panel 32, that is, the displayed image on the liquid crystal display panel 32, is transmitted through the liquid crystal display panel 32.
The light is focused onto a projection lens 31 by a condensing lens (Fresnel lens in the figure) disposed on the front side of the projector, and is enlarged and projected onto a screen 34 disposed in front of the projector.

Note that the light source device is used not only in liquid crystal projectors but also in general projectors that project images of films or the like onto a screen surface.

[Problem that the invention attempts to solve]

By the way, in a high-voltage arc lamp such as a xenon lamp used in the light source device of the projector, the anode electrode 13 generates heat due to collision of electrons, and the anode side of the lamp 10 has heat. must be released to the outside to prevent overheating on the anode side. However, in conventional light source devices, the lamp 10 is customarily arranged with its anode side facing the light projection direction and its cathode side facing the rear of the reflector 20. Yes, for that purpose, lamp 10
The radiant heat from the reflector 20 is stuck inside the reflector 20, and this heat cannot be efficiently radiated to the outside (particularly when the light source device is installed horizontally so that the lamp 10 is horizontal, the heat radiation efficiency becomes even worse). ), and since the anode side of the lamp 10 is in the light projection direction, this anode side is also heated by the heat reflected by the reflector 20, so the anode side of the lamp 10 becomes very hot, and the glass tube 1
There was a problem in that the sealing portion between the lamp 1 and the anode side cap 12 could peel off due to the difference in their coefficients of thermal expansion, causing the lamp 10 to burst. For this reason, conventionally,
A fan blows cooling air into the reflector 20 to forcibly cool the anode side of the lamp 10, but this also cools the arc discharge part of the lamp 10, reducing the luminance of the lamp 10. It was supposed to be done.

This idea was developed in view of the above-mentioned circumstances, and its purpose is to efficiently dissipate the heat generated on the lamp anode side and to cool the discharge part together with the lamp anode side more than necessary. To provide an efficient light source device that does not cause overheating and does not cause a decrease in luminous efficiency, and also does not cause the anode side of a lamp to be overheated by heat reflected by a reflector.

[Means to solve problems]

In this invention, the discharge lamp is arranged in such a direction that the anode terminal side thereof is closer to the reflector than the cathode terminal side, and at least a part of the anode terminal side of the discharge lamp is made to protrude behind the reflector. The device is characterized in that a heat dissipation section is provided.

[Effect]

In other words, this idea overturns conventional wisdom and arranges a high-voltage arc lamp with the cathode side facing the light projection direction and the anode side facing the rear of the reflector. According to this light source device, since the anode side of the lamp is made to protrude behind the reflector, the heat generated on the lamp anode side can be radiated outside the reflector. There is no need to cool the discharge part together with the lamp anode side more than necessary, reducing the luminous efficiency, and the lamp anode side is not overheated by the heat reflected by the reflector. Destruction is less likely to occur and luminous efficiency can be improved.

〔Example〕

An example of this invention is shown below in Figures 1 and 2.
This will be explained with reference to the figures. Components corresponding to the conventional light source device shown in FIG. 5 are designated by the same reference numerals in the figure, and their description will be omitted.

In this light source device, a high voltage arc lamp, for example, a xenon lamp 10 is arranged with its cathode side facing the light projection direction and its anode side facing the rear of the reflector 20. The lamp 10 has a large number of heat dissipating fins 15, 15 protruding from a hole 21 provided in the reflector 20 in the projecting part. The heat dissipation fins 15, 15 are provided so as to protrude rearwardly, and the heat dissipation fins 15, 15 are provided radially around the anode side cap 12.

However, in this light source device, the lamp 1
Since the anode side of the lamp 10 is made to protrude behind the reflector 20, the heat generated on the lamp anode side can be radiated outside the reflector 20, and the anode side of the lamp 10 can be radiated by the heat reflected by the reflector 20. Heat dissipation fin 1
The heat dissipation by 5 and 15 can prevent overheating of the lamp anode side, and therefore, the sealing part between the glass tube 11 and the anode side cap 12 will separate due to the difference in coefficient of thermal expansion, and the lamp 10 will burst. can be prevented. Note that the permissible temperature of a normal xenon lamp (temperature that does not cause the lamp to explode) is approximately 200°C, and the permissible temperature of a saphire xenon lamp in which the glass tube 11 is a saphire glass tube is approximately 350°C.
According to this light source device, the heat radiation fins 15, 1
The temperature of the lamp 10 can be suppressed to the above-mentioned allowable value or less only by heat dissipation by the lamp 5. In addition, in this light source device, since the cathode side of the lamp 10 faces the light projection direction, this cathode side is heated by the heat reflected by the reflector 20, but the heat generation temperature on this cathode side is relatively low. Therefore, even if the cathode side is heated by the heat reflected by the reflector, the temperature on the cathode side will not exceed the above-mentioned allowable value.

In the above embodiment, the heat dissipation fin 1 is provided on the anode side of the lamp 10 that protrudes behind the reflector.
Although the radiation fins 15 and 15 are provided radially, the radiation fins 15 and 15 may be provided parallel to the lamp axis direction as shown in FIGS. 3 and 4. Furthermore, although this light source device does not forcibly send cooling air into the reflector using a fan or the like, it may be possible to provide a fan or the like in some cases.

[Effect of idea]

According to the light source device of this invention, the discharge lamp is arranged in such a direction that its anode terminal side is closer to the reflector than its cathode terminal side, and at least a part of the anode terminal side of the discharge lamp projects behind the reflector. Since a heat dissipation part is provided on this protrusion, the heat generated on the lamp anode side can be efficiently dissipated, and the anode side of the lamp will not be overheated by the heat reflected by the reflector. There is no need to cool down the discharge part along with the side more than necessary, reducing luminous efficiency.
It is possible to provide an efficient light source device that is less likely to overheat.

[Brief explanation of the drawing]

1 and 2 are a longitudinal sectional side view of a light source device and a front view of a heat radiation fin portion showing an embodiment of the invention, and FIGS. 3 and 4 are a front view and a side view showing a modified example of the heat radiation fin. , FIG. 5 is a longitudinal sectional side view of a conventional light source device, and FIG. 6 is a diagram showing the principle configuration of a liquid crystal projector. 10...Lamp, 11...Glass tube, 12...
Base, 13... anode electrode, 13a... anode terminal,
14... cathode electrode, 14a... cathode terminal, 15...
...Radiation fin, 20...Reflector, 21...Hole.

Claims (1)

[Claims for Utility Model Registration] A light source device comprising a discharge lamp having terminals at both ends and a reflector that reflects light from the lamp and projects it forward, wherein the discharge lamp has an anode terminal side and a cathode terminal side. A light source characterized in that the discharge lamp is arranged in a direction closer to the reflector, at least a part of the anode terminal side of the discharge lamp projects behind the reflector, and a heat radiation part is provided in this projecting part. Device.