JP2002270008A - Vehicular infrared flood-light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular infrared flood-light capable of eliminating a visible light cutting filter to shield the visible light, which has been used in a conventional vehicular infrared flood-light adopting an incandescent lamp causing heating and emission of visible light, and which has been deteriorated by heating to lower its reliability. SOLUTION: This vehicular infrared flood-light 1 is formed by combining the plural of a flood-light unit 2 composed of a LED lamp 3 for infrared emission and a reflecting surface 4 having a free-formed curved surface, which is provided in front to intercept almost all quantity of light from the LED lamp 3 with the virtual focus point f0 of the LED lamp 3 as a focus point and the axis Y of which is almost perpendicular to its optical axis Z at the position of the virtual focus point f0. Thereby, a visible light cutting filter which has conventionally caused deterioration of characteristics due to overheating is dispensed with by using the LED lamp for infrared emission, which emits no visible light when radiating infrared rays, as a light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared night-vision apparatus used as a visual aid for visual recognition under poor visibility such as at night.
In the infrared night vision apparatus, the present invention relates to a configuration of an infrared projector for emitting infrared rays toward a detection range in order to detect an object by reflected light.

[0002]

2. Description of the Related Art A conventional infrared projector 90 of this kind for a vehicle is known.
FIG. 7 shows an example of the configuration of an infrared projector 90 (hereinafter simply referred to as an infrared projector 90).
It comprises a rotating paraboloid having the light source 91 as a focal point, or a reflecting surface 92 which is a free-form surface of a parabolic system, and a visible light cut filter 93 which covers the front of the reflecting surface 92.

[0003] With this configuration, the light source 91
Is radiated from the reflecting surface 9 having a free-form surface, for example.
According to 2, reflection is performed as a light distribution characteristic having an irradiation angle that is wide in the horizontal direction and narrow in the vertical direction. And
Since the visible light cut filter 93 is provided in the reflection direction, only infrared light is projected as the light distribution characteristics described above. Although not shown, the light source 9
In some cases, a substantially cylindrical visible light cut filter is attached to the first filter.

[0004]

However, in the infrared projector 90 having the above-mentioned conventional configuration, the light source 91 is not provided.
The visible light occupying a considerable part of the energy radiated from the filter is shielded by the visible light cut filter 93, so that the temperature of the visible light cut filter 93 rises remarkably and the deterioration is liable to occur. Has been problematic.

[0005] Further, since the above configuration is substantially the same as a vehicle lamp such as a headlight, for example, the size is also substantially the same, and it is difficult to reduce the size of the infrared projector 90. I have. Further, in the configuration in which the visible light cut filter is attached to the light source 91, the temperature of the visible light cut filter is further increased, and the reliability is further impaired.

[0006]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, an infrared-emitting LED lamp and a light amount from the LED lamp having a virtual focal point of the LED lamp as a focal point are provided. And a free-form reflective surface having a parabolic system whose axis is substantially orthogonal to the optical axis at the position of the virtual focal point. An object of the present invention is to solve the problem by providing a vehicle infrared projector that is configured by combining a plurality of infrared projectors.

[0007]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. In FIG. 1 and FIG. 2, reference numeral 2 denotes a light projecting unit constituting a vehicle infrared projector (hereinafter, abbreviated as infrared projector 1) according to the present invention.
The light emitting unit 2 is an LE emitting infrared light.
It comprises a D lamp 3 and a free-form surface reflecting surface 4 of a parabolic system.

Here, prior to the description of the light projecting unit 2, the structure of the LED lamp 3 will be described. As shown in FIG.
LE, the most widely supplied shape for lamp 3
A resin case 3 in which the top of the D chip 3a has a lens shape.
b may be sealed, and this type emits light in the form of a beam having an emission angle α of approximately ± 25 ° at a position where the illuminance is halved from the maximum value.

When the emission angle α of the LED lamp 3 is extended toward the LED chip 3a and the intersection with the optical axis Z is obtained, it does not coincide with the position where the LED chip 3a is arranged. Is also often behind. In the present invention, the intersection between the radiation angle α and the optical axis Z is set as the virtual focal point f0 of the LED lamp 3.

Referring again to FIGS. 1 and 2, the LED
The lamp 3 is arranged vertically with the optical axis Z attached to the vehicle. The free-form surface reflection surface 4 is a parabolic free-form surface in which a parabola P appears in a vertical cross section along the optical axis Z. At this time, the parabola P is located at the virtual focal point f0 or in the vicinity thereof. The focal point is used, and the axis Y is substantially orthogonal to the optical axis Z (see FIG. 2). Therefore, the axis Y is substantially horizontal when mounted on the vehicle.

By arranging the LED lamp 3 and the free-form surface reflection surface 4 in this manner, the free-form surface reflection surface 4 is provided.
Is located in front of the irradiation direction of the LED lamp 3, and the width W (see FIG. 1) of the free-form surface reflection surface 4 and the depth D (see FIG. 2) in the direction of the axis Y are made appropriate. L
The entire amount of the light emitted from the ED lamp 3 within the irradiation angle α reaches the free-form surface reflection surface 4.

Here, the free-form surface reflection surface 4 is formed by the L
Beam-like light from the ED lamp 3, that is, a virtual focus f0
The light is reflected at the vertex and spreads in a substantially conical shape in the irradiation direction, and is reflected in the detection direction, and the shape of the reflected light beam is converted into a shape corresponding to the detection range required as a night vision device. The configuration of the free-form surface reflection surface 4 will be described below.

First, considering the shape of a preferable detection range of a night vision device for a vehicle, since the vehicle moves freely on the ground surface, a detection range that is not so wide in the vertical direction is not required. In the horizontal direction, a considerably wide detection range is required in preparation for turning of the vehicle.

Therefore, the free-form surface reflection surface 4 is
After reflecting the light from the D lamp 3, it is required to form a flat light distribution shape that is narrow in the vertical direction and wide in the horizontal direction. The free-form reflecting surface 4 is
As described above, since a parabola P having a virtual focal point f0 as a substantially focal point appears on the vertical cross section along the optical axis Z, the light from the LED lamp 3 is reflected as substantially parallel rays and is narrow. It will illuminate the area.

On the other hand, the free-form reflecting surface 4 is
In this embodiment, as shown in FIG. 1, the LED lamp 3 is in a state viewed from the front, that is, in a cross section orthogonal to the axis Y, a straight line along the horizontal direction appears at any position in any position. The light is reflected without converging on light from the light source.

In the present invention, the shape of the free-form surface reflecting surface 4 is not limited to the parabolic surface described above.
For example, any shape such as a paraboloid of revolution with the axis Y as the center of rotation, the parabolic column described above, or a reflective surface shape that obtains a desired radiation angle as an intermediate shape. In short, it is only necessary that the light distribution characteristics finally required as the infrared light projector 1 can be formed by combining a plurality of light projection units 2 as described later.

FIG. 4 shows an infrared projector 1 according to the present invention constructed by combining a plurality of the above-mentioned light projecting units 2. As described above, each of the light projecting units 2 is provided.
Since the irradiation angle is set narrow in the vertical direction and wide in the horizontal direction, the plurality of light emitting units 2 are arranged in a row in the horizontal direction so as not to impair the characteristics. A combination has been made.

FIG. 5 shows the light distribution characteristics H of the infrared light projected by the infrared light projector 1. According to the results of the study by the inventor, the light distribution characteristics H have an irradiation angle of approximately 20 ° on each of the right and left sides. It has been confirmed that an irradiation angle of 3 ° on the upper and lower sides is sufficient for general vehicle traveling.

However, even at night, it is expected that the vehicle will travel at a relatively high speed when traveling straight ahead. For security, the left and right sides of the vehicle indicated by reference numeral Hc in FIG.
It is desirable to set the range of 3 と し て to a higher detection sensitivity than other parts, that is, it is desirable to distribute a large amount of infrared light so as to be able to reliably detect a distant obstacle. confirmed.

Therefore, the combination of the light projecting units 2 in the infrared light projector 1 is also performed based on the above description. The light emitting unit 2 is, for example, a parabolic surface, and secures a wide detection range in the horizontal direction.

Next, the operation and effects of the infrared projector 1 of the present invention having the above-described configuration will be described. First, by adopting the infrared-emitting LED lamp 3 as the light source, only the infrared light is emitted from the light source.
Unlike conventional incandescent lamps, they do not emit visible light that is unnecessary for the purpose of the present invention. Therefore, basically, a visible light cut filter is not required, and at the same time, luminous efficiency with respect to supplied power is improved.

Also, when a visible light cut filter is provided for design reasons or the like, the visible light cut filter does not absorb the energy of the visible light, so that the temperature does not rise, and therefore, the filter is not overheated. There is no change in the characteristics of the visible light cut filter, and the reliability of the infrared projector 1 is improved.

Furthermore, by adopting a configuration in which the beam-like light from the LED lamp 3 is received by the free-form surface reflection surface 4 installed in the front direction, almost all of the light from the LED lamp 3 is used as detection light. The light beam can be directed in the irradiation direction, and the luminous flux utilization rate is improved. In addition, since there is no problem of the above-mentioned overheating and the free-form surface reflection surface 4 may be partial, the whole infrared projector 1 can be reduced in size and weight.

FIG. 6 shows another embodiment of the infrared light projector 1 according to the present invention. The absolute light amount is smaller than that of an incandescent lamp or the like, no matter how high the luminous efficiency of the LED lamp 3 is. It is in. Therefore, in order to secure a sufficient amount of light, it is necessary to configure the infrared light projector 1 by combining a considerable number of light emitting units 2, but as in the previous embodiment, one row of the light emitting units 2 has an aspect ratio (vertical and horizontal). Ratio) becomes large, giving the user of the vehicle a sense of incompatibility with the design or making it difficult to select a place to be mounted on the vehicle.

In such a case, the light emitting units 2 may be arranged in two rows as shown in the figure, but also in this case, the irradiation width in the vertical direction is prevented from expanding more than necessary. Each row is lined up along a horizontal line, and
Preferably, the two rows are arranged close together.

Further, since a small amount of light is emitted from the LED lamp 3 in a direction other than the above-mentioned emission angle α, an auxiliary reflection surface indicated by reference numeral 5 in the drawing is provided.
The light emitted in a direction other than the radiation angle α may be reflected and collected toward the free-form reflecting surface 4.

[0027]

As described above, according to the present invention, an infrared-emitting LED lamp and an optical axis of the LED lamp having the virtual focal point of the LED lamp as a focal point and receiving almost all of the light amount from the LED lamp are provided. A vehicle infrared projector that is configured in combination with a plurality of light projection units each including a free-form surface reflection surface having a parabolic system whose axis is substantially orthogonal to the optical axis at the position of the virtual focus, First, the use of an LED lamp that emits infrared light without emitting visible light in the emission of infrared light makes it possible to eliminate the need for a visible light cut filter that has caused problems such as characteristic deterioration due to overheating. This is an extremely excellent effect for improving the reliability of this type of vehicle infrared projector.

Further, due to the characteristics of the LED lamp which emits light in a beam-like range together with the reduction of the above-mentioned heat generation, this L
The reflecting surface for giving desired light distribution characteristics to the light from the ED lamp can be small, and it is possible to reduce the size and weight of the infrared projector for a vehicle and to achieve an extremely excellent effect on cost reduction. It will be.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a vehicular infrared projector according to the present invention, which is a main part of a projector unit.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an explanatory diagram showing a virtual focus of an LED lamp.

FIG. 4 is a perspective view showing an embodiment of a vehicle infrared projector according to the present invention.

FIG. 5 is a graph showing light distribution characteristics of the vehicle infrared projector according to the present invention.

FIG. 6 is a perspective view showing another embodiment of a vehicle infrared projector according to the present invention.

FIG. 7 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Infrared light projector for vehicles 2 ... Light emitting unit 3 ... LED lamp 3a ... LED chip 3b ... Resin case 4 ... Reflection surface of free-form surface 5 ... Auxiliary reflection surface Z ... Optical axis of LED lamp Y … Axis of free-form reflective surface f0… virtual focus of LED lamp

Claims (4)

[Claims] 1. An infrared light emitting LED lamp, and
A parabolic surface which is provided in front of the optical axis of the LED lamp so as to receive substantially all of the light amount from the LED lamp with the virtual focal point of the D lamp as a focal point and whose axis is substantially orthogonal to the optical axis at the position of the virtual focal point An infrared projector for a vehicle, comprising a combination of a plurality of projection units each including a free-form reflecting surface. 2. The vehicle infrared projector according to claim 1, wherein the free-form reflecting surfaces are combined with each other to form a light distribution pattern required for the vehicle infrared projector. 3. The infrared projector according to claim 1, wherein a combination of the plurality of light emitting units is arranged in one row or two rows in a horizontal direction. 4. The infrared projector according to claim 1, wherein the light distribution pattern is ± 20 ° or less in a horizontal direction and ± 3 ° or less in a vertical direction. .