JPH0741044Y2 - Multi-lamp headlight - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-lamp type headlamp having a structure in which headlamps are arranged side by side, and in particular, a headlamp using a discharge lamp as a light source and a headlamp using a tungsten filament as a light source. The present invention relates to a multi-lamp type headlight in which and are arranged side by side.

[0002]

2. Description of the Related Art An automobile headlamp must have a light distribution pattern that brightly illuminates the front of its own lane and does not dazzle an oncoming vehicle.

Therefore, an automobile headlight has both a sub beam for passing an oncoming vehicle and a main beam for traveling alone (when there is no oncoming vehicle), and can be switched by a driver's switch operation. Is configured as follows.

Has a light distribution characteristic that does not dazzle an oncoming vehicle,
As a headlamp having a simple lens configuration and capable of reducing the overall shape, for example, a projector headlamp for an automobile has been proposed. FIG. 3 is a plan view schematically illustrating an example of this type of projector headlight, FIG. 4 is a side view of the same, and FIG.
Is also a front view.

Reference numeral 1 is a concave mirror, and F is its focal point. The light source bulb 2 is provided so that the filament is located near the focal point F.

A convex lens 3 is provided so as to share the optical axis Z with the concave mirror 1.

Reference numeral ij shown in FIG. 3 denotes the meridional image plane of the convex lens 3, and the light emitted from the light source and reflected by the concave mirror 1 is incident on this meridional image plane.

The above-mentioned incident light is modulated by the convex lens 3 and projected forward (to the right in FIGS. 3 and 4).

A screen is provided in the vicinity of the meridional image plane, and the light distribution pattern is shown by isolux curves as shown in FIG. H-H is a horizontal line on the screen, and V-V is a vertical line.

As shown in FIGS. 3-5, a shade 4 having an edge along the meridional image plane is provided. For more information,
As indicated by 4a shown in FIG. 5, a cut line 4a is formed so as to recede downward from the horizontal section i-j of the meridional image plane. FIG. 6 shows how the above-described light distribution pattern and the shade 4 overlap. As shown in FIG. 6, the upper half of the light flux passes through. Most of the lower half is blocked, but light is allowed to pass through the portion corresponding to the cutting line 4a.

Since the luminous fluxes partially covered as described above are condensed on the meridional image planes i-j and intersect each other, the luminous flux projected in front of the headlight has a shape obtained by inverting FIG. Pattern is formed. FIG. 7 is an explanatory view showing a schematic shape of a projection pattern by an isolux curve on a screen provided in front of the headlight.

The above-mentioned light distribution pattern shown in FIG. 7 is suitable as a beam for passing each other. However, in the traveling beam without the oncoming vehicle, the cut line 4a '
There is no need to be cut off the light projection.

Therefore, if the shade 4 is omitted from the projector type headlight shown in FIGS. 3 to 5, the light flux in the portion shown by hatching in FIG. 6 is not cut, and as shown in FIG. A light distribution pattern can be obtained.

The light distribution pattern of FIG. 7 and that of FIG.
To switch between and use the light distribution pattern of shade 4
Is a movable structure and can be advanced or retracted into the optical path. A projector type headlight having a movable shade based on such a concept has also been proposed (for example, Japanese Utility Model Laid-Open No. 63-165703).

However, installing a movable member and its drive system in a headlamp which becomes hot during lighting involves various technical difficulties, and makes the headlamp large, heavy and expensive. In addition, durability and operational reliability are not without problems.

Therefore, a projector-type multi-lamp type (four-lamp type in this example) headlamp as shown in FIG. 9 is constructed.

Reference numeral 7 is a projector type headlight having a light distribution pattern having a cut line as shown in FIG. 7 (that is, provided with a shade 4) and is used when passing each other.

Reference numeral 8 denotes a projector type headlight having a light distribution pattern which is substantially symmetrical vertically and horizontally as shown in FIG. 8 (that is, the shade 4 is omitted), when there is no oncoming vehicle. Used in so-called running.

It is also possible to select and light only a desired headlight of the two types of headlights, ie, the passing headlight 7 and the traveling headlight 8. In order to configure the entire multi-lamp type headlamp device in a small size, light weight, and inexpensively, generally, only the passing headlamp 7 is turned on when there is an oncoming vehicle, and when there is no oncoming vehicle, the traveling headlight is used. The lights 8 are also turned on together (all four lights are turned on in this example) to brightly illuminate the front of the road.

Further, a discharge lamp is used as a light source for power saving.

However, even in the discharge lamp according to the latest technology, it is difficult to turn on, turn off, and turn on again immediately.
The traveling headlight 8 which is repeatedly turned on and off is constituted by a projector headlight having a tungsten filament as a light source.

The passing headlight 7 is composed of a projector type headlight using a discharge lamp as a light source, and as a general rule, it is always lit during night driving.

Although the above description has been given of the projector-type multi-lamp type headlamp as a conventional example, the light source of the traveling headlamp is not limited to the projector-type type, and the light source of the traveling headlamp is composed of a tungsten filament. The light source of the passing headlight is often composed of a discharge lamp.

[0024]

As described above, when different kinds of light sources are used together, a problem of color temperature difference occurs.

FIG. 10 is a spectrum distribution chart, in which the horizontal axis represents wavelength (nanometer) and the vertical axis represents luminous intensity.

Like the spectrum distribution curve 9 of an incandescent light bulb and the spectrum distribution curve 10 of a halogen light bulb, the spectrum distribution of light emitted from a tungsten filament has a substantially flat shape, but a short wavelength component is present in the visible light region. For example, the luminosity near 400 nm is almost zero.

On the other hand, the spectrum distribution curve 11 of the discharge lamp includes a large number of bright line spectra, but shows a substantially uniform distribution in the visible light region.

In FIG. 9, only one of the traveling headlight 8 using the tungsten filament as the light source and the traveling headlight 7 using the discharge lamp as the light source is turned on and visually observed with the naked eye. Looks like light. However, when both headlights 7 and 8 are turned on at the same time, the light of the headlight 8 for traveling, which uses the tungsten filament as a light source, feels reddish. The reason is that the color temperature of the discharge lamp is 4000 to 4500K, which is similar to the true white light, whereas the color temperature of the tungsten filament is 2700 to 3200K, which is a wavelength band near 400 nanometers. Is small.

While the passing headlamp 7 shown in FIG. 9 is turned on and the illumination of the light distribution pattern as shown in FIG. 7 is kept on, the traveling headlamp 8 is further turned on to illuminate the front of the road. , If you try to combine the two lights to provide suitable lighting for traveling (when there is no oncoming vehicle), lights with different color tones form the respective zones, which gives the driver a strange feeling. Cause

The present invention has been made in view of the above circumstances, and is a multi-lamp type headlamp including a headlamp using a discharge lamp as a light source and a headlamp using a tungsten filament as a light source. The purpose is to eliminate the discomfort caused by the difference in the color temperature of.

[0031]

The basic principle of the present invention created to achieve the above object is to correct a color difference between different light sources by filtering a light beam emitted from a light source.

However, if the conventional technique is simply diverted and filtered, there is a risk that undesired defects will appear as side effects. Therefore, the present invention is based on the premise that no adverse side effects occur. We tried to eliminate the discomfort caused by the difference.

For example, as a filtering mechanism in a projector type headlight, the technique disclosed in Japanese Utility Model Laid-Open No. 2-34002 is also known. According to this known technique, filtering at the time of lighting is possible, but at the time of non-lighting. Cause problems with the appearance of.

FIG. 11 is a sectional view showing an example of a projector type headlamp having a filtering mechanism to which the above-mentioned known technique is applied. A reflector 36 is arranged in a lamp housing 38, and a first reflector 36 is provided. A light source 37 made of a tungsten filament is installed near the focal point. 13 is a socket.

Reference numeral 14 is an aspherical convex lens, and 15 is a light shielding plate (shade).

A multilayer film coating 16 is applied to the back surface (the right surface in the figure) of the aspherical convex lens 14.

The above-mentioned multilayer film coating 16 is formed by laminating a plurality of transparent films having different light refraction indexes, and weakens or strengthens the lights by the interference of the lights to pass the light of a specific wavelength. It is a known optical constituent member that reflects light other than the specific wavelength (light of a complementary color of the specific wavelength).

FIG. 12 is a schematic optical path diagram in the vicinity of the aspherical convex lens (coated with a multilayer film).

When the light 17 emitted from the light source is incident on the multilayer coating 16 as indicated by the arrow a, yellow light 18 is emitted by the arrow b.
And the complementary color light 19 of yellow light is reflected as shown by arrow c. As a result, this multilayer coating 16
The projector type headlight (FIG. 11) having the aspherical lens 14 provided with the above as a constituent member can be used as, for example, a fug lamp.

However, when extraneous light 20 such as sunlight enters as shown by arrow d, yellow complementary color light 21 is emitted by arrow e.
The light is reflected and emitted. Therefore, the aspherical lens 1
4 emits pseudo light as complementary color light.

Since the present invention constitutes a multi-lamp type headlight that does not cause the above-mentioned colored pseudo light emission and does not give a strange feeling to the driver, the luminous flux emitted from the discharge lamp A color temperature conversion filter having a function of lowering the color temperature of the light source (specifically, lowering the color temperature of the radiant light emitted from the light source) is arranged in the optical path of the above.

In carrying out the present invention, it is preferable to use the color temperature conversion filters of Decami Red 2 to 15.

The above-mentioned Decami Red is a numerical value showing the conversion ability of color temperature, and is defined by JIS B7125. This Decami Red is determined as follows.

Now, it is assumed that the color temperature of the radiant light emitted from the light source is K ₁ .

The color temperature of the radiant light after passing through the color temperature conversion filter is K ₂ .

In this case, the decamillet is defined by the following equation in units of 1 billion times the reciprocal of the color temperature.

(10 ⁵ / K ₂ -10 ⁵ / K ₁ ) Decami Red

[0048]

As described above, the headlight using the discharge lamp as the light source,
In a multi-lamp headlight in which a headlamp using a tungsten filament as a light source is arranged side by side, a color temperature conversion filter having a function of lowering the color temperature of the light source is arranged in the optical path of the light flux emitted from the discharge lamp. Of the radiant light emitted from the discharge lamp, a wavelength band having a relatively short wavelength is cut, and a color tone similar to that of the tungsten filament is exhibited.

For this reason, as shown in FIG. 9, for example, a multi-lamp type headlamp including a passing headlamp 7 using a discharge lamp as a light source and a traveling headlamp 8 using a tungsten filament as a light source. Also, the driver does not feel discomfort due to the color tone difference of the light source.

[0050]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view showing an embodiment of a projector headlight using a discharge lamp as a light source among a plurality of projector headlights constituting a multi-lamp headlight according to the present invention. It is a figure.

The multi-lamp type headlamp of this embodiment is a four-lamp type, and its front external view is similar to the front external view of the conventional example shown in FIG. 9 above. The projector type headlight of the present embodiment shown in FIG. 1 is used as a passing headlight in FIG. 9, and the discharge lamp 22 constitutes a light source bulb.

The discharge lamp 22 is installed near the first focal point of the spheroidal reflector 23. 24 is a socket.

For the reflector 23, the frame 2
A convex lens 26 is supported via 5 and a shade 27 is fixed to the frame 25.

The rear surface of the convex lens 26 (the light source bulb 22
A color temperature conversion filter 28 is provided on the surface on which the light flux emitted from

FIG. 2 is a characteristic curve chart of five types of color temperature conversion filters, and each of these five types of color temperature conversion filters has a function of lowering the color temperature.

The horizontal axis of this chart represents wavelength (nanometers), and the vertical axis represents transmittance (percentage).

A curve 31 represents the transmittance characteristic of the color temperature conversion filter of Decami Red 2, a curve 32 represents the transmittance characteristic of the color temperature conversion filter of Decami Red 4, and a curve 33 represents the transmittance of the color temperature conversion filter of Decami Red 8. The curve 34 represents the transmittance characteristic of the color temperature conversion filter of the Decami Red 11, and the curve 35 represents the transmittance characteristic of the color temperature conversion filter of the Decami Red 13, both of which have a large red color tone transmittance. And,
The transmittance of reddish color is large.

Although the color temperature conversion filter (curve 33) of Decami Red 8 is used in this example, any one of the five types of color temperature conversion filters shown in FIG. 2 can be used when the present invention is carried out. It is possible to use a material having a transmittance characteristic similar to this.

(Refer to FIG. 1) The radiant light emitted from the discharge lamp 22 is bluish as compared with the light of the tungsten filament, as described with reference to the curve 10 in FIG.

However, after the bluish light flux is reflected by the reflector 23, it is passed through the color temperature conversion filter 28 immediately before entering the convex lens 26, and the color temperature is lowered (in order to be close to red). Filtered), convex lens 2
At 6, the light is refracted in the converging direction and becomes a substantially parallel light beam, which is projected to the right in the figure.

For this reason, the bluish component of the emitted light from the discharge lamp, which was bluish in comparison with the emitted light from the tungsten filament, is cut and becomes closer to red, which is similar to the emitted light from the tungsten filament.

Therefore, as shown in FIG. 9, for example, a multi-lamp type headlamp in which a passing headlamp 7 using a discharge lamp as a light source and a traveling headlamp 8 using a tungsten filament as a light source are arranged side by side. Even if configured, both headlights project light fluxes having similar color tones, and the driver does not feel discomfort.

Further, in FIG. 1, even if extraneous light in the direction of arrow g (for example, sunlight) is incident from the front of the convex lens 26, the colored light is reflected by the color temperature conversion filter 28 and forward of the lamp as indicated by arrow h. There is no danger of emission. Therefore, there is no possibility of colored pseudo light emission.

[0064]

As described above, the present invention is applied to a multi-lamp type headlight in which a headlight using a discharge lamp as a light source and a headlight using a tungsten filament as a light source are arranged side by side, If a color temperature conversion filter that has the function of lowering the color temperature of the light source is installed in the optical path of the light flux emitted from the electric lamp, there is no risk of colored pseudo light emission, and moreover, there is a difference in the color tone of the light source to the driver. There is no fear of giving a sense of discomfort.

[Brief description of drawings]

FIG. 1 is a sectional view of a projector type headlight which constitutes one embodiment of a multi-lamp type headlight according to the present invention.

FIG. 2 is a characteristic chart for explaining the functions and effects of the color temperature conversion filter in the above embodiment.

FIG. 3 is a schematic plan view for explaining a projector headlight.

FIG. 4 is a side view of the same.

[Figure 5] Similarly, a front view

FIG. 6 is a light distribution pattern chart in the vicinity of the shade.

[Figure 7] Similarly, a light distribution pattern chart on the screen

FIG. 8 is a light distribution pattern chart when the shade is omitted as well.

FIG. 9 is a front view for explaining a four-lamp headlight.

FIG. 10: Spectral spectrum chart of various light sources

FIG. 11 is a cross-sectional view showing an example of a fug lamp configured by a projector type headlamp provided with a multilayer coating.

FIG. 12 is a schematic diagram for explaining the action and effect of the multilayer coating in the above-mentioned fog lamp.

[Explanation of symbols]

1 concave mirror 2 light source bulb 3 convex lens 4 shade 4a cut line of shade 4a 'cut line of light distribution pattern 7 headlight for passing 8 headlight for traveling 9 characteristic curve of incandescent light bulb 10 characteristic curve of halogen light bulb 11 discharge lamp Characteristic curve 14 Aspherical convex lens 15 Light shield 16 Multi-layer coating 17 Light emitted from light source 18 Yellow light 19 Complementary light of yellow light 20 External light 21 Complementary color light 22 Discharge lamp 23 Reflector 24 Socket 25 Frame 26 Convex lens 27 Shade 28 color Temperature conversion filter 31 Transmittance characteristic curve of color temperature exchange filter of Decami Red 2 32 Transmittance characteristic curve of color temperature exchange filter of Decami Red 4 33 Transmittance characteristic curve of color temperature exchange filter of Decami Red 8 34 Color temperature exchange filter of Decami Red 11 of Transmittance characteristic curve of the color temperature exchange filters over-rate characteristic curve 35 Dekamireddo 13

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F21V 9/08 Z H05B 35/00

Claims (1)

[Scope of utility model registration request] 1. A multi-lamp type headlight in which a headlight using a discharge lamp as a light source and a headlight using a tungsten filament as a light source are arranged side by side, and a light source is provided in an optical path of a light beam emitted from the discharge lamp. A multi-lamp type headlamp having a color temperature conversion filter having a function of lowering the color temperature of the headlamp.