JP2000222935A - Light source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source unit having a simplified structure wherein a lens member susceptible to heat is directly cooled. SOLUTION: A light source unit U1 contains a lens member 20 installed in front of a reflector R for refracting arc light in a desired direction so as to form it into a desired light flux. The generation of the arc produces a high heat which tends to be stored in the lens member 20 serving as a light transmitting member rather than be stored in the reflector R having reflection surface. The heat causes expansion/contraction repetition of the lens member 20, resulting in impairing original functions of a lens as well as developing a crack therein. This result is caused by a lens of variations in thickness unlike a flat plate. Accordingly, a cooling member 22 made of metal (for example, aluminum with a good cooling efficiency, etc.), is attached on a peripheral side 20A of the lens member 20 for concentratedly cooling thereof.

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 having a discharge tube for generating light of a predetermined wavelength by the emission of an arc, and a reflector for reflecting light from the discharge tube and emitting light in a predetermined direction. It is about.

[0002]

2. Description of the Related Art Conventionally, there is Japanese Utility Model Publication No. 4-17965 as a technique in such a field. The light source unit described in this publication has a configuration in which an explosion-proof glass is attached to an explosion-proof cylinder fixed to a front portion of a reflector. The explosion-proof cylinder is provided with an intake port and an exhaust port, and the blower fan allows the outside air taken in from the intake port to flow through the explosion-proof cylinder while discharging it from the exhaust port. The heat is actively discharged to the outside so that it does not accumulate in the explosion-proof cylinder.

[0003]

However, the above-mentioned conventional light source unit has the following problems. In other words, the cooperation of a large number of intake ports and exhaust holes provided in the explosion-proof cylinder causes forced convection of heat in the explosion-proof cylinder so that heat generated from the light source lamp is efficiently discharged to the outside. Therefore, it is necessary to form an intake port and an exhaust port having a complicated shape in the explosion-proof cylinder, which causes a problem that the cost is increased. In addition, as a structure of the light source unit, there are JP-A-10-97802 and JP-T-8-511902.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in particular, has a light source unit capable of directly cooling a lens member which is easily affected by heat while simplifying the structure. The purpose is to provide.

[0005]

According to a first aspect of the present invention, there is provided a light source unit having a hollow light-emitting portion for accommodating a pair of discharge electrodes for generating an arc in a state where the discharge electrodes face each other. In a light source unit comprising an arc tube having a pair of front and rear sealing portions and a rear sealing portion provided, and a rear sealing portion fixed to a reflector, a lens member is provided at a front portion of the reflector, A cooling member made of metal is provided on the outer peripheral surface of the lens member.

In this light source unit, the arc light is refracted in a desired direction at the front of the reflector.
A lens member for producing a desired light beam is attached. Also, when an arc occurs, high heat is generated,
This high heat, rather than a reflector with a reflective surface,
It tends to be accumulated in a lens member having a function of transmitting light. If the lens member repeatedly expands / contracts under the influence of heat, not only does the original function of the lens deteriorate, but it also causes cracks. This is because the lens member does not have a uniform thickness like a flat plate. Therefore, in order to centrally cool the lens member, a cooling member made of metal (for example, aluminum having good cooling efficiency) is attached to the outer peripheral surface of the lens member.

In the light source unit according to the second aspect, it is preferable that a lens housing for receiving a peripheral portion of the lens member is provided at a front end of the reflector. When such a configuration is adopted, the lens member can be easily and reliably mounted on the reflector via the lens housing portion formed on the reflector.

In the light source unit according to the third aspect, it is preferable that the reflector and the lens member are connected via a cooling member. When such a configuration is adopted, reflectors having different sizes can be easily joined to the lens member by changing the shape of the cooling member.
It can be said that versatility is extremely high. Further, not only the lens member but also the reflector can be cooled by the cooling member, which enables extremely efficient unit cooling.

In the light source unit according to the fourth aspect, the cooling member preferably has a cooling fin projecting outward. When such a configuration is employed, the cooling fins can further improve the cooling efficiency.

In the light source unit according to the fifth aspect, it is preferable that a notch is provided at a position facing the front sealing portion at the front end of the reflector. When such a configuration is employed, the notch provided in the reflector allows outside air to be taken into the reflector, and the light source unit can be cooled from the inside.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a light source unit according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing a light source unit according to the present invention. The light source unit U1 shown in the figure has a reflector R having a reflection surface on the inner surface.
Is fixed to a mercury-xenon lamp 1 as an example of an arc tube. As shown in FIG. 2, the mercury xenon lamp 1 includes a bulb 2 made of glass (for example, quartz) or ceramics (for example, translucent ceramics). The bulb 2 has a hollow light emitting portion 3 having a substantially elliptical sphere at the center, and a gas such as mercury is sealed inside the light emitting portion 3.

Further, the bulb 2 has a pair of sealing portions 4 and 5 extending from both sides of the light emitting portion 3. When the bulb 2 is mounted on the reflector R, the sealing portion 4 is located on the rear side and the reflector R And the sealing portion 5 is placed in a free state in the reflector R with the front side thereof. In addition, each sealing part 4,5
Inside, thin metal foils 6 and 7 made of molybdenum are sealed, and one end side of the metal foil 6 is electrically connected to a discharge electrode 8 projecting from one direction into the light emitting portion 3. A first lead wire 9 exposed from the rear end of the sealing portion 4 is electrically connected to the other end of the foil 6.

Similarly, the discharge electrode 1 is provided at one end of the metal foil 7.
The second lead wire 11 exposed from the front end of the sealing portion 5 is electrically connected to the other end of the second lead wire 11. In addition, W (tungsten) or the like can be used as a material of the metal foils 4 and 5. A metal base 12 is fixed to the rear end of the rear sealing portion 4 of the bulb 2, and a first lead wire 9 is electrically connected to the base 12,
The base 12 is fixed to the reflector R. The male screw portion 13 of the base 12 and the second lead wire 11 are respectively connected to an external power supply circuit (not shown) so as to generate a predetermined arc discharge between the discharge electrodes 8 and 10.

Here, as shown in FIG. 1, a glass lens member 20 is fixed to the front portion of the glass reflector R via an adhesive, and the lens member 20 extends from the circular outer periphery toward the center. It is formed as a concave lens having a reduced thickness, and has a lens characteristic of emitting light reflected by the reflector R as parallel light. In addition, although borosilicate glass is generally used for the lens member 20, quartz glass having heat resistance and impact resistance may be used in some cases.

The lens member 20 and the reflector R
As a means for easily integrating the lens member 20 with an adhesive, a peripheral portion 2 of the lens member 20 is provided at the front end of the reflector R.
A lens receiving portion 21 for receiving Oa is formed. The lens accommodating portion 21 has an L-shaped cross section and is formed in a flange shape at the front end of the reflector R. Specifically, the lens accommodating portion 21 has a rising portion 21a projecting in the radial direction of the reflector R having a circular opening, and a lens member projecting forward from the outermost end of the rising portion 21a. And a frame portion 21b for facilitating the positioning operation in the radial direction. The lens accommodating portion 21 is provided with a substantially entire circumference at a front end portion of the reflector R or a notch portion 24 described later.
It is molded integrally with the entire circumference except for. Further, in consideration of expansion / contraction of the lens member 20 due to high heat, the frame portion 21b of the lens housing portion 21 is attached when the light source unit U1 is assembled.
It is preferable to be separated from the lens member 20.

Further, when an arc is generated, high heat is generated, and this high heat tends to be accumulated in the lens member 20 having a function of transmitting light, rather than the reflector R having the reflecting surface. It is in. When the lens member 20 repeatedly expands / contracts under the influence of high heat, not only the original function of the lens is impaired, but also the generation of cracks. This is because the lens member 20 does not have a uniform thickness like a flat plate.

Therefore, in order to centrally cool the lens member,
A metal cooling member 22 is fixed to an outer peripheral surface 20A of the lens member 20 via an adhesive.
It is formed in a ring shape, is fitted into the outer peripheral surface 20A, and is adhesively fixed. The cooling member 22 is preferably made of aluminum, copper, or the like having high thermal conductivity. The cooling member 22
Is disposed near the blower fan, the lens member 20
Is further improved.

At the front end of the reflector R, an arc-shaped notch 24 is provided at a position facing the front sealing portion 5.
Is provided. The cutouts 24 are provided in a pair on the left and right sides so as to sandwich the sealing portion 5. Therefore,
The outside air can be taken into the reflector R through the notch 24, and the light source unit U1 can be cooled from the inside. In particular, this notch 24
As a result of facing the sealing portion 5, the sealing portion 5 is intensively cooled. That is, the notch portion 24 is formed at this position so that the cooling air does not directly hit the light emitting portion 3. This is because a change in the temperature of the light emitting section 3 adversely affects the characteristics of arc light emission.

The light source unit of the present invention is not limited to the embodiment described above. For example, in the light source unit U2 shown in FIG. 3, the ring-shaped aluminum cooling member 30 may include a cooling fin 30a, and the cooling fin 30a is formed so as to protrude outward from the ring body 30b. , Enables further cooling of the lens member 20. Further, the ring body 30b is
Extends over the entire outer peripheral surface 20A. Then, the rear end of the ring body 30b is connected to the lens housing 21 of the reflector R.
And the cooling of the reflector R by the cooling member 30 is also enabled.

In the light source unit U3 of still another embodiment, as shown in FIG. 4, the reflector R1 and the lens member 20 are connected via the cooling member 40. The cooling member 40 has a lens housing 41 at a front end thereof and a reflector housing 42 at a rear end thereof. Specifically, the lens housing portion 41 is
3 and a stopper projecting piece 41b projecting radially from the main body 43. The reflector accommodating portion 42 is formed by projecting a flange portion 42a rearward from an outer end of the main body 43. When the reflector R1 and the lens member 20 are connected to each other by an adhesive with the cooling member 40 interposed therebetween, the reflector R1 and the lens member 20 having different sizes can be easily combined. Therefore, this structure makes it possible to freely combine the reflector R1 and the lens member 20, and it can be said that the versatility is extremely high. Furthermore, not only the lens member 20 but also the reflector R1 can be cooled by the cooling member 40 having a large cooling area, thereby enabling extremely efficient cooling.

The above-mentioned cooling members 22, 30, 40
Need not be provided on the entire circumference of the outer peripheral surface 20A of the lens member 20, and may be arranged so as to be divided into a plurality of parts.

[0023]

Since the light source unit according to the present invention is configured as described above, the following effects can be obtained. That is, it has a hollow light-emitting portion that accommodates a pair of discharge electrodes that generate an arc in a state of facing each other, and a pair of front and rear sealing portions provided on both sides of the light-emitting portion. In a light source unit having an arc tube and a rear sealing portion fixed to a reflector, a lens member is provided at a front portion of the reflector, and a metal cooling member is provided on an outer peripheral surface of the lens member. It is possible to directly cool a lens member that is easily affected by heat while simplifying the structure.

[Brief description of the drawings]

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

FIG. 2 is a front view showing an arc tube used for a light source unit.

FIG. 3 is a sectional view showing another embodiment of the light source unit according to the present invention.

FIG. 4 is a sectional view showing still another embodiment of the light source unit according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Arc tube, 3 ... Light emitting part, 4 ... Rear sealing part, 5 ... Front sealing part, 8, 10 ... Discharge electrode, 20 ... Lens member, 20A
... Outer peripheral surface, 21 ... Lens accommodation part, 22, 30, 40 ... Cooling member, 24 ... Notch part, 30a ... Cooling fin, U1,
U2, U3 ... light source unit, R, R1 ... reflector.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeki Ishihara 1126 Nomachi, Hamamatsu-shi, Shizuoka Prefecture F-term in Hamamatsu Photonics Co., Ltd. 3K014 AA01 LA01 LB04 MA02 MA04 MA08

Claims (5)

[Claims] 1. A hollow light emitting portion for accommodating a pair of discharge electrodes for generating an arc in a state of facing each other, and a pair of front and rear sealing portions provided on both sides of the light emitting portion. A light source unit comprising a light emitting tube having: a rear sealing portion fixed to a reflector; a lens member provided at a front portion of the reflector; and a metal cooling member provided at an outer peripheral surface of the lens member. A light source unit characterized in that: 2. The light source unit according to claim 1, wherein a lens housing for receiving a peripheral portion of the lens member is provided at a front end of the reflector. 3. The light source unit according to claim 1, wherein the reflector and the lens member are connected via the cooling member. 4. The light source unit according to claim 1, wherein the cooling member has a cooling fin protruding outward. 5. The light source unit according to claim 1, wherein a cutout portion is provided at a front end of the reflector at a position facing the front sealing portion.