JPH0535559Y2 - - Google Patents

Description

[Detailed description of the invention] [Field to which the invention pertains] The present invention relates to an optical device incorporating a short arc type metal vapor discharge lamp.

[Conventional technology]

Short arc metal vapor discharge lamps are used in projectors and industrial exposure equipment. For example, mixed metal vapor discharge lamps with good color rendering properties are incorporated into projectors or used as backlights. Mercury discharge lamps are also used to expose semiconductor wafers.

As is already well known, these metal vapor discharge lamps have metals or metal compounds for discharge condensed in the low-temperature part of the discharge lamp even when the lamp is off or on. In order to exhibit good performance as a device, it is generally necessary to vaporize these condensates quickly or sufficiently.
Therefore, even if we look at past patent documents, there are many inventions and ideas for quick or sufficient vaporization.

[Purpose of this invention]

In the present invention, we focused on the exhaust chip (the remaining part of the exhaust pipe that remains when the exhaust pipe used in the discharge lamp manufacturing process is removed), which is well known as a condensation site for these metals or metal compounds, and incorporated it into the optical device. It is an object of the present invention to provide an optical device which, when used, can quickly and sufficiently vaporize condensate in an exhaust chip without adversely affecting the luminous flux extracted from the optical device.

[Means to achieve the purpose]

In this invention, in order to achieve the above purpose,
The optical device is constructed as follows.

That is, the metal vapor discharge lamp includes a short arc type metal vapor discharge lamp, a concave mirror arranged so that its optical axis coincides with the arc direction of the discharge lamp, and a lens system that takes in the light coming from the concave mirror. The exhaust chip provided in the bubble is provided in the bulb area outside the angle θ facing the concave mirror from the highest brightness point of the arc, and the entire area extending from the outer surface of the exhaust chip to the base. A heat-retaining membrane should be provided.

[Operation] In order not to disturb the light flux entering the lens system, if an exhaust chip is installed in the bulb area outside the angle at which the concave mirror is viewed from the point of highest brightness of the arc, the temperature inside the exhaust chip will rise. Therefore, by providing a heat insulating film over the entire area from the outer surface of the exhaust chip to the hem, the temperature of the exhaust chip can be easily raised.

〔Example〕

FIG. 1 is an explanatory diagram of the main parts of the optical device of the present invention. In the figure, reference numeral 1 denotes a short arc type mercury-xenon discharge lamp, in which a predetermined amount of mercury and xenon are filled so that the total pressure is about 2 atmospheres during lighting. 2 is an anode, 3 is a cathode, and a concave mirror 4 is arranged so that the direction of the arc coincides with the optical axis. In this case, the cathode 3 is generally located at the back of the concave mirror 4.

The position of the highest brightness of the arc is near the tip of the cathode and is commonly called the "cathode bright spot P." A concave mirror is placed in the range facing from this bright spot, and the light collected by the concave mirror 4 is passed through the lens. Send it to system 5. The exhaust chip 6 is located at the valve position within the angle θ of this facing range.
If this exists, the light flux incident on the lens system 5 will be disturbed and the performance of the optical device will be deteriorated. Therefore, the exhaust chip 6 is located in the bulb area outside the range of the angle θ, as shown in the figure. Instead, the intense light from the highest brightness location does not directly hit the inside of the exhaust chip, making it difficult for the inner wall of the exhaust chip to rise in temperature, thereby expanding the area where the heat insulating film is provided on the outer surface of the exhaust chip. This situation is shown in FIG.

FIG. 2 is an enlarged view of the exhaust chip, and 7 is a heat insulating film. This heat insulating film 7 is provided over the entire outer surface of the exhaust chip, including the curved surface portion R (hereinafter referred to as the base) on which the exhaust chip rises. By this,
The temperature of the exhaust chip and the inside will rise easily.

The above-mentioned discharge lamp is suitably used as a light source device for semiconductor exposure when it is turned on with a DC power supply of 29V, a current of 38A, and a power consumption of approximately 1100W. This is because the condensate in the exhaust chip evaporates quickly or sufficiently, but the light flux extracted from the device is not disturbed.

[Effect of idea]

As can be understood from the description of the above embodiments, the present invention is capable of quickly or sufficiently vaporizing the condensate condensed on the exhaust chip without disturbing the luminous flux extracted from the optical device. A good optical device with a built-in electric light can be provided. The technology disclosed herein can also be used for projectors and backlight light sources incorporating mixed metal vapor discharge lamps.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the main parts of the optical device of the present invention, and FIG. 2 is an explanatory diagram of a heat-retaining film. In the figure, 1 is a mercury-xenon discharge lamp, 2 is an anode, 3 is a cathode, 4 is a concave mirror, 5 is a lens system, 6 is an exhaust chip, 7 is a heat insulation film, P is a cathode bright spot, X is an optical axis, and R is a Indicates the hem.

Claims (1)

[Claims for Utility Model Registration] Includes a short arc metal vapor discharge lamp, a concave mirror arranged so that its optical axis coincides with the arc direction of the discharge lamp, and a lens system that captures light coming from the concave mirror. , an exhaust tip provided on the bulb of the metal vapor discharge lamp is provided in an area of the bulb outside the angle θ facing the concave mirror from the highest arc brightness position, and the outer surface of the exhaust tip is An optical device in which a heat-retaining film is provided over the entire area spanning the crow's hem.