JP2001101923A - Light source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source unit which can realize downsizing and weight saving corresponding to miniaturization of mobile type of LCD projection device, prevent flying of fragments of a luminescent tube of the light source unit when the luminescent tube bursts during its lighting on, cool the luminescent tube and a reflecting membrane wall, be without devitrification of the luminescent tube and deterioration of the reflecting membrane, and has high optical coefficient of utilization, brightness, and long life. SOLUTION: A light source unit comprising a reflecting mirror having a reflecting surface which is a paraboloidal surface, an oval surface, a spherical surface, or a combination thereof, a light source device provided with a discharging lamp with shielded ends fixed such that the light axis thereof coincides with the reflecting mirror, and a housing frame for the light source device used when the light source device is built in a projecting equipment, is characterized in that a diameter portion of the front mirror surface of the reflecting mirror is cut, which does not reflect efficiently light radiated from the discharging lamp to an optical system, and the housing frame of the light source device is provided with a light transmittable material mounted in front thereof and a ventilation hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source unit used for a projection device such as a liquid crystal projection device.

[0002]

2. Description of the Related Art A discharge lamp such as a short arc type high pressure mercury lamp or a metal halide lamp is used as a light source in a light source unit used for a projection device such as a liquid crystal projection device. The light of this discharge lamp is reflected by a reflecting mirror having a paraboloid, ellipsoid, spherical surface or a combination thereof, and the irradiation surface is further reduced by a small, high-density active matrix liquid crystal device or optical component. Irradiate uniformly.

[0003] The short arc type discharge lamp used in a projection device such as a liquid crystal projection device or the like has an improved optical utilization factor by reducing the size of the arc tube and approaching a point light source. However, in a short arc type discharge lamp, the internal pressure of the arc tube during operation is very high, and thus the arc tube may burst during operation.

A light source device in which a glass plate is fixed to the front surface of a reflector so as to prevent fragments of the arc tube from scattering even if the arc tube ruptures during lighting is described in Japanese Patent Application Laid-Open No. H5-251054. . In addition, along with the miniaturization of mobile liquid crystal projection devices and the like, a light source device is required to be smaller, and as shown in FIG. 2, the discharge lamp 21 is not vertically reflected in the optical system in the vertical and horizontal directions. A rectangular small, short-focused reflecting mirror 22 without unnecessary parts is fixed so as to coincide with the optical axis of the reflecting mirror 22, and a glass plate 23 is disposed at the front opening of the reflecting mirror 22 to form a light source device. Some light source units are bonded to the light source device housing frame 24 to form a light source unit.

[0005]

However, in the above light source device, since the inside of the light source device is sealed by the glass plate on the front surface of the reflecting mirror, the temperature of the upper part of the arc tube tends to be high, and the material of the arc tube is made of a material. Devitrification phenomenon of certain quartz glass and oxidation of welding point between electrode and molybdenum foil are likely to occur,
The discharge lamp has a short life. Further, the cooling of the reflection film of the discharge lamp and the reflection mirror is insufficient, so that the devitrification phenomenon of the arc tube and the deterioration of the reflection film occur, and the optical utilization factor is deteriorated. Therefore, when downsizing the light source unit,
It is necessary to reduce the lamp power and suppress the temperature above the arc tube.

[0006] In addition, the structure of the above-mentioned square reflecting mirror is difficult because the structure of the cloth is more difficult than that of the conventional round reflecting mirror and the surface accuracy is deteriorated. There are problems with the properties of the mirror. Further, since the rectangular reflector requires a certain thickness in structure, it is difficult to further reduce the size and weight.

The present invention relates to a light source unit using a light source device in which a glass plate is fixed to the front surface of a conventional round reflector, and a light source device in which a glass plate is fixed to the front surface of a small and short focal length square reflector. In order to solve the above-mentioned problem of the light source unit using the light source unit, it is possible to further reduce the size and weight of the light source unit with the downsizing of the mobile liquid crystal projection device and the like, and to emit light during lighting. Even if the tube ruptures, the arc tube fragments do not scatter and the cooling of the arc tube and the reflection film can be improved, and there is no devitrification phenomenon of the arc tube or deterioration of the reflection film, and the optical utilization factor High, bright,
It is an object of the present invention to provide a light source unit having a long life.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a reflector having a paraboloid, an ellipse, a sphere or a combination thereof. In a light source unit having a light source device including a discharge lamp of both ends sealed type fixed to match the optical axis, and a light source device housing frame used when incorporating the light source device into projection equipment, A reflecting mirror having a front surface with a cut diameter that does not effectively reflect the light emitted from the discharge lamp to the optical system; and the reflecting mirror is substantially sealed by the light source device housing frame. An optical material is provided, and a ventilation hole is provided in the light source device housing frame.

According to the first aspect of the present invention, the size and weight of the light source device can be reduced, and even if the arc tube ruptures during lighting, pieces of the arc tube do not scatter, and the arc tube and the reflector are not scattered. It is possible to obtain a light source unit having a high optical utilization factor, a high brightness, and a long service life, in which the film can be cooled well, the devitrification phenomenon of the arc tube does not occur, and the reflection film does not deteriorate.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a top sectional view when a light source unit according to an embodiment of the present invention is incorporated in a device. A light source device is composed of a discharge lamp 1 sealed at both ends and a reflecting mirror 2 that reflects light emitted from the discharging lamp 1. The discharge lamp 1 is fixed with the optical axis of the reflecting lamp 2 coincident with the reflecting mirror 2. ing. The discharge lamp 1 is an arc tube made of quartz glass.
The light emitting section 3 has a substantially elliptical spherical shape with an inner diameter of 4.3 mm, an outer diameter of 9.4 mm, and an inner volume of 0.06 cc.

[0013] Sealing portions 4 are formed at both ends of the arc tube light emitting portion 3. A tungsten electrode 6 having a core rod diameter of 0.3 mm and a molybdenum wire 7 having a wire diameter of about 0.6 mm (one side not shown) are connected to the sealing portion 4 via a molybdenum foil 5 having a length of 20 mm. I have. The electrode 6
Are arranged so that the distance between the front ends of the two is 1.2 mm. This is the arc tube that is configured to, mercury 13mg as a buffer gas, argon gas of about 1.6 × 10 ⁴ Pa as a starting auxiliary gas, bromine as hydrogen bromide 1.6 × 10 ^-7 mol / cc is enclosed.

The reflecting mirror 2 has a reflecting surface composed of a paraboloid of revolution having a focal length of 6 mm, and the effective diameter of the reflecting surface is φ5.
0 mm, the diameter of the front surface, which does not effectively reflect the light emitted from the discharge lamp to the optical system, is 5 m in both vertical and horizontal directions.
Each m is a cut portion 8. Then, a base 10 of the discharge lamp 1 is provided with a cement 11 in a cylindrical portion 9 behind the reflecting mirror 2.
And is connected to the reflecting mirror 2 via the. The front opening of the reflecting mirror 2 is substantially closed by a light source device housing frame 12, and a glass 13 as a light transmitting material is provided in front of the light source device housing frame 12. The light source device housing frame 11 has holes 14 of 2 mm on the left and right sides thereof.
Are opened at four locations at intervals of 5 mm.

The light source unit configured as described above is
In comparison with the weight of the light source unit using the conventional square reflecting mirror, the weight was reduced by about 35 g. Furthermore, when compared with the thickness of the square reflecting mirror, the thickness in the vertical and horizontal directions is about 6 mm each.
It was thinner and smaller. Further, as compared with the square reflecting mirror, the fabric can be easily processed and the reflection surface accuracy is good, so that problems such as illuminance and color unevenness due to unevenness of the reflective film are less likely to occur.

[0014] The discharge lamp of the light source unit is 120 W
When the lamp was turned on with the electronic ballast for rated power and cooled using a DC 12 V fan to perform a life test, no problem occurred even if the lighting time passed 2,000 hours. In addition, when the light source unit of FIG. 1 was overloaded and a forced rupture test was performed to confirm that fragments were scattered when the arc tube ruptured, it was also confirmed that there was no damage to the actual liquid crystal projection device or the like. .

[0015]

As described above, according to the present invention,
Since the size and weight of the light source unit can be reduced, it is possible to cope with further downsizing of a mobile projection device and the like. In addition, even if the arc tube ruptures during lighting, the shards can be prevented from being scattered, preventing damage to optical components such as a liquid crystal projection device, and also allowing the lamp and the reflective film to be cooled. Suppressing the devitrification of the tube, preventing oxidation of the welding point between the electrode and the molybdenum foil, and reducing the deterioration of the reflection film
A long life light source unit can be obtained. Further, since the shape of the reflecting mirror does not require a special shape, it is possible to obtain a light source unit having good reflecting surface accuracy, non-uniformity of the reflecting film, and less illuminance and color unevenness.

[Brief description of the drawings]

FIG. 1 is a top sectional view showing a light source unit according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a light source unit using a conventional square reflecting mirror. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge lamp 2 Reflector 3 Light-emitting part 4 Sealing part 5 Molybdenum foil 6 Electrode 7 Molybdenum wire 8 Cut part of the diameter part of the front surface 9 Tube part 10 Base 11 Cement 12 Light source device housing frame 13 Glass 14 hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F21Y 101: 00 F term (Reference) 3K042 AA01 AB03 AC04 AC06 BA01 BB03 BB05 BB06 BC01 CC02 CC06

Claims (1)

[Claims] 1. A reflector having a paraboloid, an ellipsoid, a sphere or a combination thereof, and a discharge lamp sealed at both ends which is fixed with its optical axis coincident with the reflector. A light source unit having a light source device housing and a light source device housing frame used when assembling the light source device into a projection apparatus, wherein a front-side diameter portion that does not effectively reflect light emitted from the discharge lamp to an optical system is formed. The cut reflector and the reflector are substantially sealed by the light source device housing frame, a light-transmitting material is provided in front of the light source device housing frame, and a ventilation hole is provided in the light source device housing frame. A light source unit characterized by the above-mentioned.