JP2008293774A - Discharge lamp with reflecting mirror - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp with a reflecting mirror in which not only thermal deterioration is suppressed by reflecting emitting light leaking from the glass end of a rear sealing part of the arc tube and its surrounding and suppressing temperature increase of a component in the projector installed at the back of the lamp, but also the amount of emitting light to the front is increased by adding the reflection light as emitting light to the front. <P>SOLUTION: The discharge lamp 1 with the reflecting mirror has an arc tube 2 housed inside the reflecting mirror 3 and the glass end 4 of the rear sealing part of the arc tube 2 is exposed to the rear of the reflecting mirror 3. At least the glass end of the rear sealing part of the arc tube 2 is made a mirror finish reflection processing part 7 in which a mirror finish reflection processing is applied. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a discharge lamp with a reflector used for a light source for a projector.

  The light emitting portion of the arc tube of the discharge lamp with a reflecting mirror is located at the focal point of a bowl-shaped reflecting mirror such as a spherical surface, an elliptical surface, or a parabolic surface. The light emitted from the arc tube is reflected by the reflecting film applied to the inner surface of the reflecting mirror and emitted in front of the lamp. The emitted light is incident on an optical system provided in front of the lamp.

  On the other hand, as shown in FIG. 5, the light is emitted backward from the glass end portion 104 of the rear sealing portion of the arc tube 102 protruding from the rear portion of the reflecting mirror 103 of the discharge lamp 101 with a reflecting mirror.

  As shown in FIG. 6, the radiated light leaking from the glass end portion 104 of the rear sealing portion of the arc tube 102 includes heat energy and is emitted with a sharp directivity. For this reason, there has been a problem that the components in the projector installed behind the lamp cause thermal deterioration. Further, there is a problem that the effective light emitted to the front part of the lamp is reduced by the amount emitted to the rear part of the lamp.

In order to suppress thermal deterioration of the components in the projector installed behind the lamp, the arc tube is housed inside the reflector, and the glass end of the rear seal part of the arc tube is located at the rear of the reflector. In an exposed discharge lamp with a reflector, a discharge lamp with a reflector has been proposed in which the glass end portion of the rear sealing portion of the arc tube is a frosted portion (see, for example, Patent Document 1).
JP 2006-253048 A

  However, according to Patent Document 1, even if the glass end portion of the rear sealing portion of the arc tube is used as a frosted portion, the temperature of the part where the diffused radiation is irradiated rises by 95 ° C., and the effect is It was not enough.

  The present invention has been made to solve the above-described problems, and is disposed at the rear part of the lamp by reflecting the radiated light leaking from the glass end part and the peripheral part of the rear sealing part of the arc tube. Providing a discharge lamp with a reflector that not only suppresses the thermal deterioration by suppressing the temperature rise of the components in the projector, but also increases the amount of light emitted forward by adding the reflected light as the forward radiation. The purpose is to do.

  The discharge lamp with a reflecting mirror according to the present invention is the discharge lamp with a reflecting mirror in which the arc tube is housed inside the reflecting mirror, and the glass end of the rear sealing portion of the arc tube is exposed at the rear of the reflecting mirror. The glass end portion of the rear sealing portion of the arc tube is a specular reflection processed portion subjected to specular reflection processing.

  Moreover, the discharge lamp with a reflecting mirror according to the present invention is characterized in that the glass outer wall surface around the end of the rear sealing portion is also a specular reflection processing portion.

  Moreover, the discharge lamp with a reflector according to the present invention is characterized in that the specular reflection processing portion is formed by forming a metal thin film on the glass surface by vapor deposition or sputtering.

  Moreover, the discharge lamp with a reflector according to the present invention uses a heat-resistant adhesive with a specular reflection processing portion, a metal film having a shape that covers at least the glass end portion of the rear sealing portion, or a metal housing. It is characterized by bonding.

  The discharge lamp with a reflector according to the present invention is configured to reflect the sharp directional radiated light leaking from the glass end portion of the rear sealing portion of the arc tube and the peripheral glass outer wall surface by the specular reflection processing portion according to the above configuration, In addition to suppressing the thermal deterioration by suppressing the temperature rise of the components in the projector installed at the rear part of the lamp, there is an effect that the intensity of the forward radiated light is increased.

Embodiment 1 FIG.
FIG. 1 to FIG. 4 are diagrams showing Embodiment 1, FIG. 1 is a side view in which a part of a discharge lamp 1 with a reflecting mirror is broken, and FIG. 2 is a side view of a main part of the discharge lamp 1 with a reflecting mirror (a). 3 is a front view of the main part (b), FIG. 3 is a diagram showing a state in which the radiated light from the rear part of the discharge lamp 1 with a reflecting mirror is suppressed by the reflection shielding of the specular reflection processing part 7, and FIG. It is a figure which shows the test result which compared the temperature rise of the components in the 1 back projector with the conventional method.

  As shown in FIG. 1, a discharge lamp 1 with a reflecting mirror (hereinafter also referred to as a lamp) has an arc tube 2 housed inside a reflecting mirror 3. The light emitting portion of the arc tube 2 is located at the focal point of a bowl-shaped reflecting mirror 3 such as a spherical surface, an elliptical surface, or a parabolic surface. The emitted light is reflected by the reflecting film applied to the inner surface of the reflecting mirror 3 and is emitted in front of the lamp. The emitted light is provided in front of the lamp and enters the optical system.

  The arc tube 2 is sealed at both ends, and is fixed to the reflecting mirror 3 with an inorganic adhesive in the vicinity of the rear sealing portion. And the glass edge part 4 of a rear part sealing part protrudes behind the reflective mirror 3, and is exposed outside.

  As shown in FIG. 2, the glass end portion 4 of the rear sealing portion and the exposed glass outer wall surface 9 are mirror-reflected to form a specular reflection processing portion 7.

  Note that the specular reflection processing portion 7 that performs the specular reflection processing may be only the glass end portion 4 of the rear sealing portion from which most of the leakage radiation light is emitted.

  The specular reflection processing of the specular reflection processing portion 7 is generally a method in which a metal thin film is formed on a glass surface by a method such as vapor deposition or sputtering. The metal used may be a single metal element such as aluminum, silver, gold, copper, nickel, platinum or rhodium, an alloy thereof, or an alloy such as iron, nickel or chromium.

  As another method of forming the specular reflection processing portion 7, a metal film having a shape covering the glass end portion 4 of the rear sealing portion and the peripheral glass outer wall surface 9 or a metal casing is coated with a heat resistant adhesive. May be used for bonding. You may adhere | attach a metal film or a metal housing | casing only on the glass edge part 4 of a rear part sealing part using a heat resistant adhesive.

  The metal film or the metal housing may be in contact with the conductive wire 10 of the one-side electrode at the rear of the discharge lamp 1 with a reflector. However, it is necessary to carefully arrange the conductive wire 11 that is in conduction with the other opposite electrode of the discharge lamp 1 with a reflecting mirror so as to be electrically insulated.

  FIG. 3 shows the glass end 4 of the rear sealing portion and the peripheral portion of the discharge lamp 1 with a reflecting mirror, which has been subjected to such specular reflection processing on the glass end portion 4 of the rear sealing portion and the peripheral glass outer wall surface 9. The state of the radiated light leaking from the glass outer wall surface 9 is shown. Radiation light leaking from the glass end 4 of the rear sealing part and the surrounding glass outer wall surface 9 is almost blocked by the reflection of the specular reflection processing part 7, and is a component in the projector installed behind the discharge lamp 1 with a reflecting mirror. It is considered that the temperature rise of 8 can be suppressed. Further, it is considered that the light deterioration of the component 8 in the projector mainly caused by ultraviolet light can be suppressed.

  Next, in order to verify the effect of the specular reflection processing portion 7 applied to the glass end portion 4 of the rear sealing portion and the peripheral glass outer wall surface 9, the directivity of sharp radiated light without applying the conventional specular reflection processing is provided. The temperature rise of the component 8 in the projector installed behind the discharge lamp 1 with the reflecting mirror was compared between the lamp radiated at 1 and the lamp of the present embodiment.

  The test results are shown in FIG. In the test, an aluminum film having a thickness of 0.05 mm was brought into close contact with the glass end 4 of the rear sealing portion and the glass outer wall surface 9 in the vicinity of the power 300 W, and the components in the projector from the glass end 4 of the rear sealing portion. The temperature rise of the component 8 in the projector was measured when the distance L was 15 mm.

  As is apparent from FIG. 4, when the glass end portion 4 of the rear sealing portion is subjected to specular reflection processing, the temperature rise of the component 8 in the projector is greatly reduced. The conventional method (Patent Document 1) in which the glass end portion 4 of the rear sealing portion is not mirror-finished or frosted has a temperature increase of 47 ° C., whereas the present embodiment has 7 ° C. The reason why the absolute value of the temperature rise is different from that of Patent Document 1 is that the amount of cooling air from the cooling fan, the types of components in the lamp and the projector, the arrangement of components, heat dissipation, conduction heat conditions, etc. do not always match.

  In addition, the rear part of the discharge lamp 1 with a reflecting mirror becomes high temperature while the lamp is lit. In the case of the present embodiment, as a result of temperature measurement, the temperature is 200 ° C. or less, and even when an aluminum metal having a relatively low melting point of 660 ° C. is used as the reflective film, the temperature is kept sufficiently low, and the aluminum melts. It is understood that there is no problem in temperature even when aluminum or other metal heat resistant tape is used, and the effect of the present embodiment can be obtained.

  As described above, specular reflection processing is performed on the glass end 4 of the rear sealing portion of the arc tube 2 and the peripheral glass outer wall surface 9 (at least the glass end 4 of the rear sealing portion) of the discharge lamp 1 with a reflecting mirror. Thus, it is possible not only to significantly reduce the temperature rise of the component 8 in the projector by reflecting the sharp directional radiated light, but also by reflecting the radiated light toward the rear of the lamp, Strength can be increased.

The side view which fractured | ruptured a part of discharge lamp 1 with a reflecting mirror in the figure which shows Embodiment 1. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1, The principal part side view (a) and principal part front view (b) of the discharge lamp 1 with a reflecting mirror. FIG. 5 shows the first embodiment, and shows a state in which radiated light from the rear part of the discharge lamp 1 with a reflecting mirror is suppressed by the reflection shielding of the specular reflection processing unit 7. FIG. 5 shows the first embodiment, and shows the test results comparing the temperature rise of the components in the projector behind the discharge lamp 1 with a reflecting mirror with the conventional method. The principal part side view (a) and principal part front view (b) of the conventional discharge lamp 101 with a reflecting mirror. The figure which shows the radiated light which leaks from the rear part of the conventional discharge lamp 101 with a reflecting mirror.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Discharge lamp with a reflecting mirror, 2 luminous tube, 3 reflecting mirror, 4 glass edge part of a rear sealing part, 7 specular reflection processing part, 8 parts in a projector, 9 glass outer wall surface, 10 conducting wire, 11 conducting wire, 101 reflection Discharge lamp with mirror, 102 arc tube, 103 reflector, 104 glass edge of the rear sealing part.

Claims (4)

In the discharge lamp with a reflector, the arc tube is housed inside the reflector, and the glass end of the rear sealing portion of the arc tube is exposed at the rear of the reflector.
A discharge lamp with a reflecting mirror, characterized in that at least a glass end portion of a rear sealing portion of the arc tube is a specular reflection processing portion subjected to a specular reflection processing.   The discharge lamp with a reflecting mirror according to claim 1, wherein a glass outer wall surface around an end of the rear sealing portion is also a specular reflection processing portion.   The discharge lamp with a reflecting mirror according to claim 1 or 2, wherein the specular reflection processing part is a metal thin film formed on a glass surface by vapor deposition or sputtering.   The said specular reflection process part adhere | attaches the metal film of a shape which covers at least the glass edge part of the said rear part sealing part, or a metal housing | casing using a heat resistant adhesive. The discharge lamp with a reflecting mirror according to claim 2.

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