JPH05120901A - Vehicular light fixture using metal halide lamp light source - Google Patents

Abstract

PURPOSE:To prevent the lowering of color rendering immediately after the starting and lowering of visibility and misunderstanding of traffic control sign or the like. CONSTITUTION:A metal halide lamp 2 is covered with a cap 3, and the cap 3 is provided with a filter 4 for selectively reducing the wave length near 547nm as one of peak wave length of the mercury light emitting. A light emitting spectrum by mercury is thereby reduced to improve the color rendering, and improve the visibility of a lighting fixture 1 for vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular lamp such as a headlight, and more particularly to a vehicular lamp that employs a metal halide lamp which is a discharge lamp as a light source.

[0002]

2. Description of the Related Art A conventional metal halide lamp used as a light source in a vehicle lamp of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-301953, which is a translucent material provided with a pair of electrodes. The container is filled with a starting gas containing mercury, metal halides, and xenon gas, and the starting time is shortened by passing a current several times that at the time of starting compared to when it is stable. It is intended to improve the color rendering property at the time of starting by utilizing the light emission by.

[0003]

However, in the metal halide lamp in which the starting gas containing the above-mentioned conventional xenon gas is enclosed, the curve K of FIG. 3 shows the emission of the above-mentioned xenon gas in the starting state. As described above, high color rendering can be obtained, but immediately after the start-up, discharge by mercury with a lower discharge voltage becomes mainstream, which makes the emission spectrum by mercury dominant and color rendering becomes extremely extreme. It will decrease and this state will continue until the light emission by metal halide starts, and there is a problem that there is a possibility that misidentification of traffic signs etc. will occur during the above period, and the solution to this point is a problem. It was supposed to be.

[0004]

As a concrete means for solving the above-mentioned conventional problems, the present invention provides a vehicular lamp having a metal halide lamp as a light source, which is emitted from the metal halide lamp of the vehicular lamp. A metal halide characterized in that a filter for selectively attenuating a wavelength in the vicinity of 547 nm, which is one of the peak wavelengths of mercury emission, is inserted in the optical path through the front lens to the outside of the lamp. By providing a vehicular lamp having a lamp light source, the conventional problems described above are solved.

[0005]

EXAMPLES The present invention will now be described in detail based on the examples shown in the drawings. FIG. 1 shows a first embodiment of the present invention, and a metal halide lamp 2 which is a light source of the vehicular lamp 1 is covered with a cap 3 formed of a transparent member such as glass, A multilayer interference filter 4 is formed on either the inside or outside of the cap 3 to selectively attenuate a wavelength around 547 nm, which is one of the peak wavelengths of light emitted by mercury.

[0006] By doing so, the vehicle lamp 1
As shown by a curve F in FIG. 3, the light emitted from the LED has a color rendering property immediately after the start of lighting until the light emission by the metal halide is started, and the peak wavelength of mercury light emission is suppressed by the multilayer interference filter 4. It will be improved.

As is clear from the curve K of FIG. 3, in the metal halide lamp 2, after a predetermined time has passed after the lighting, the light emission of the metal halide gives a light emission color with no problem in color rendering. The cap 3 may cover the metal halide lamp 2 only for a predetermined time after starting, for example, for one minute, and after that time, for example, may move forward and stop its operation. In this case, the multilayer The loss of the light amount due to the insertion of the membrane interference filter 4 can be avoided during most of the usage time of the vehicular lamp 1.

FIG. 2 shows the second embodiment of the present invention as well. In the previous embodiment, the cap 3 for covering the metal halide lamp 2 is provided, and the multilayer interference filter 4 is formed on the cap 3. On the other hand, in this embodiment, the front lens 5 that is originally used as a component of the vehicular lamp 1 is utilized, and the multilayer interference filter 4 is formed on either the front surface or the back surface of the front lens 5. However, the present invention can be carried out without providing new additional parts, and the same operation and effect as the previous embodiment can be obtained.

That is, in the present invention, if it is in the optical path from the metal halide lamp 2 to the front of the front lens 5 to the outside of the vehicular lamp 1.
The multilayer interference filter 4 may be provided at any position, and an optimum position can be selected depending on conditions such as heat resistance of the multilayer interference filter 4, for example.

[0010]

As described above, according to the present invention, one of the peak wavelengths of mercury emission, which is one of the peak wavelengths of mercury emission, is in the vicinity of 547 nm in the light path emitted from the metal halide lamp, transmitted through the front lens, and irradiated to the outside of the lamp. By using a vehicle lamp of a metal halide lamp light source in which a filter for selectively attenuating the wavelength of is inserted, mercury emission is predominant in the temporary period immediately after the start of the metal halide lamp, and the color rendering is deteriorated. This is to improve by selectively attenuating the emission spectrum due to mercury in the filter, thereby preventing misidentification of traffic signs and the like, and exerting an excellent effect in improving the performance of this type of vehicle lamp. It is a thing.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a first embodiment of a vehicular lamp of a metal halide lamp light source according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of a vehicular lamp of the metal halide lamp light source according to the present invention.

FIG. 3 is a graph showing a color rendering property of a vehicle lamp of a metal halide lamp light source immediately after starting.

[Explanation of symbols]

 1 ... Vehicle lamp 2 ... Metal halide lamp 3 ... Cap 4 ... Multilayer interference filter 5 ... Front lens

[Procedure amendment]

[Submission date] December 7, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006] By doing so, the vehicle lamp 1
As shown by the curve F in FIG. 3, the light emitted from the multi-layer interference filter 4 has one of the peak wavelengths of mercury emission, which is the color rendering property immediately after the start of lighting until the emission of light by the metal halide is started. It is improved by intensively suppressing the wavelength in the vicinity of a certain 547 nm.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

As described above, according to the present invention, the vicinity of 547 nm, which is one of the peak wavelengths of mercury emission, is in the optical path from the metal halide lamp to the light passing through the front lens and being irradiated to the outside of the lamp. By using a vehicle lamp of a metal halide lamp light source in which a filter for selectively attenuating the wavelength of the Out of light is improved by selectively attenuating the emission spectrum of mercury by the filter, thereby preventing misidentification of traffic signs, etc., and improving the performance of this type of vehicle lamp. It has an excellent effect.

Claims (2)

[Claims] 1. A vehicular lamp using a metal halide lamp as a light source, wherein a peak wavelength of mercury emission is present in an optical path emitted from the metal halide lamp of the vehicular lamp, transmitted through a front lens and irradiated to the outside of the lamp. A vehicular lamp of a metal halide lamp light source, wherein a filter for selectively attenuating a wavelength near 547 nm, which is one of the above, is inserted. 2. The vehicle lamp of a metal halide lamp light source according to claim 1, wherein the metal halide lamp is a metal halide lamp containing xenon in a filling gas.