JP2006066096A - Infrared ray projection device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that it is difficult to surely weaken red-color light in a conventional infrared ray projection device for a vehicle. <P>SOLUTION: A filter 5 with an infrared ray transmitting property is arranged on a light-irradiating face of a projection lens 4, and a sub reflector 6 having a sub reflecting face 14 reflecting light from a halogen bulb 3 toward a filter 5 side is provided. As a result, red-color light LR in infrared rays LIR transmitting the filter 5 and white-color light LW reflected toward the filter 5 side by the sub reflecting face 14 and reflected by the filter 5 are mixed almost wholly at the filter 5, so that the red-color light can be surely weakened. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector-type infrared light projector for a vehicle that irradiates infrared light (infrared light) in front of the vehicle.

  Conventionally, a projector-type infrared light projector for a vehicle is known. This infrared light projector for a vehicle is used, for example, in a vehicle night vision device (near infrared light night vision camera device) that is mounted on the front of a vehicle and supports night driving. Is irradiated to the front of the vehicle to function as illumination for the night vision device for the vehicle. In such an infrared light projector for a vehicle, infrared light close to the visible light region is also irradiated, so that red light (red light emission) is visually recognized from the outside during the light projection. Such red light may be mistaken for lighting of a stop lamp or tail lamp, and is not preferable for safety.

  Therefore, an application for an infrared light projector for a vehicle (for example, Patent Document 1) in which red light is relatively thin has been filed. The vehicle infrared light projector will be described below. In addition, the code | symbol with a parenthesis respond | corresponds to patent document 1, respectively. The vehicle infrared light projector includes an ellipsoidal reflector (16B), a halogen bulb (18) disposed near the first focal point (f1) of the reflector (16B), and a projection lens (40). And an infrared light transmission film (22) directly formed on the back surface side of the projection lens (40), and an infrared light transmission film non-formation region (provided on the peripheral edge of the back surface of the projection lens (40)). 24F, 24G). In this vehicle infrared light projector, red light contained in infrared light transmitted through the infrared light transmission film (22) and white light transmitted through the infrared light transmission film non-formation regions (24F, 24G). Light is mixed and red light is relatively diluted.

JP 2003-19919 A

  However, in the above-described vehicle infrared light projector, the red light contained in the infrared light is transmitted through the infrared light transmission film (22) excluding the peripheral portion of the projection lens (40), and the projection lens Since white light is transmitted through the infrared light transmission film non-formation region (24F, 24G) in the peripheral portion of (40), the center of the irradiation light looks red and the surroundings appear white, so that a sufficient effect is obtained. It was not done. That is, it is difficult for the above-described vehicle infrared light projector to reliably dilute red light.

  The problem to be solved by the present invention is that it is difficult to reliably dilute red light in a conventional vehicle infrared light projector.

  The present invention is characterized in that a filter having infrared light transmission characteristics is disposed on the light exit surface of the projection lens, and a sub-reflector having a sub-reflection surface that reflects light from the light source to the filter side is provided. .

  In the infrared light projector for a vehicle according to the present invention, the red light contained in the infrared light transmitted through the filter on the light exit surface of the projection lens and the sub-reflecting surface are reflected to the filter side and reflected by the filter. The white light is mixed and red light is relatively diluted. As described above, the vehicle infrared light projector according to the present invention includes the red light in the infrared light transmitted through the filter and the white light reflected on the filter side by the sub-reflection surface and reflected by the filter. In the filter, since the color is mixed almost entirely, the red light can be surely diluted.

  Embodiments of an infrared light projector for a vehicle according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  Hereinafter, the configuration of the vehicle infrared light projector in this embodiment will be described. 1 and 2, reference numeral 1 denotes a vehicle infrared light projector (hereinafter simply referred to as a projector) in this embodiment. The light projecting device 1 is composed of a projector type unit. As shown in FIG. 1, the light projecting device 1 includes a main reflector 2, a light source 3, a projection lens 4 (condensing lens, convex lens), a filter 5, a sub reflector 6, and a frame 7 (holder). And an inner panel 8 (inner housing, extension).

  The light projecting device 1 is disposed in a lamp chamber (not shown) defined by a lamp housing and a lamp lens (not shown). Moreover, the said light projector 1 is each mounted in the right-and-left both sides of the front part of the motor vehicle C, for example, as shown in FIG. At least one of the right and left light projecting devices 1 is provided with a CCD camera (not shown) as an imaging means of a vehicle night vision device.

  The main reflector 2 has a shape in which one (front) side is opened and the other (rear) side is closed. A through hole 9 through which the light source 3 is inserted is provided at the center of the closed portion of the main reflector 2. The inner concave surface of the closed portion of the main reflector 2 is subjected to aluminum vapor deposition or silver coating, and is provided with a free-form main reflection surface 10 based on a spheroidal surface. The main reflecting surface 10 has a first focal point F1 and a second focal point F2. For example, a ring-shaped flange portion 11 is integrally provided at the edge of the opening of the main reflector 2. As shown in FIG. 1, the main reflecting surface 10 reflects a part of light emitted from the light source 3 as reflected light L on the flat aspheric surface (light incident surface) side of the projection lens 4. Is. The main reflection surface 10 is an uncolored reflection surface, and reflects the light from the light source 3 with the same chromaticity.

  In this example, the light source 3 uses a halogen bulb. The light emitted from the halogen bulb 3 has a peak with the largest amount of electromagnetic waves at a wavelength slightly longer than about 780 nm. Further, the amount of electromagnetic waves of the light decreases as the wavelength becomes shorter or longer than the value corresponding to this peak. Thus, the halogen bulb 3 emits a large amount of infrared light when it emits light. The halogen bulb 3 is detachably attached to the edge of the through hole 9 of the main reflector 2. The filament 12 of the halogen bulb 3 is located in the vicinity of the first focal point F1 of the main reflecting surface 10. In the present invention, a light source other than the halogen bulb 3 may be used as the light source. For example, a discharge lamp that emits light in the infrared region (a high-pressure metal vapor discharge lamp such as a so-called metal halide lamp, a high-intensity discharge lamp (HID), or the like) or an incandescent bulb may be used.

  The projection lens 4 is an aspherical lens. The light emitting surface on the front side of the lens 4 (surface on which light is emitted) has a convex aspheric surface, while the light incident surface on the rear side of the lens 4 (surface on which light is incident) is A flat aspheric surface.

  The filter 5 is made of an infrared light transmitting film, and is disposed over the entire surface on the convex aspheric surface side of the light emitting surface of the projection lens 4. That is, the filter 5 is made of, for example, a dielectric multilayer film, and is directly deposited on the convex aspheric surface of the projection lens 4. The filter 5 has optical characteristics indicated by a dotted curve in FIG. That is, the filter 5 reflects (absorbs or cuts) light in the visible region (visible light) having a wavelength of about 780 nm or less among the light components emitted from the halogen bulb 3, and the wavelength is about 780 nm or more. Infrared light (infrared light) is transmitted (infrared light transmission characteristics). The filter 5 leaks some red visible light (red light) as indicated by reference numeral 50 in FIG.

  The sub reflector 6 is disposed outside the projection lens 4. In this example, the sub-reflector 6 is provided on the inner panel 8 disposed outside the projection lens 4. That is, a window portion 13 is provided in the inner panel 8 where the projection lens 4 is located. An edge portion of the window portion 13 is bent so as to face the projection lens 4 and constitutes the sub reflector 6. A sub-reflecting surface 14 is provided on the bent edge, that is, on the surface of the sub-reflector 6 that faces the projection lens 4. The sub-reflection surface 14 reflects the direct light from the halogen bulb 3 toward the filter 5. The sub-reflecting surface 14 is a non-colored reflecting surface and reflects the direct light from the halogen bulb 3 with the same chromaticity. Alternatively, by coloring the sub-reflecting surface 14 in green or any other color, the chromaticity of light reflected by the sub-reflecting surface 14 and reflected on the filter 5 side is changed to green or any other color. It can be changed.

  The frame 7 includes, for example, a cylindrical tube portion 15 and a flange portion 16. The flange portion 16 of the frame 7 and the flange portion 11 of the main reflector 2 are fixed by a plurality of clips 18 with a packing 17 interposed therebetween. Further, the cylindrical portion 15 of the frame 7 and the projection lens 4 are fixed by, for example, a cylindrical clip 19. Thereby, the main reflector 2 and the halogen bulb 3, the projection lens 4 and the filter 5 form a unit structure via the frame 7. Further, the optical axis of the main reflecting surface 10 and the optical axis of the projection lens 4 are located on the same optical axis ZZ. The cylindrical portion 15 of the frame 7 is appropriately provided with an opening 20 through which direct light from the halogen bulb 3 passes through the sub-reflecting surface 14.

  The inner panel 8 is fixed to the lamp housing and covers the space between the light projecting device 1 having a unit structure and the lamp housing and the outer lens. That is, the inner panel 8 has an optical axis adjusting mechanism, a breathing mechanism, and a wiring mechanism arranged from the transparent lens or the substantially transparent outer lens to the inner structure, for example, the rear part of the light projecting device 1 of the unit structure in the lamp chamber. Etc. are hidden so that they cannot be seen. In addition, the light is prevented from leaking in directions other than the predetermined direction. A design surface such as aluminum vapor deposition or silver paint may be provided on at least the front side of the inner panel 8 (side facing the outer lens).

  The sensitivity characteristic of the CCD camera has a peak with the highest sensitivity at a wavelength slightly shorter than about 780 nm (in FIG. 3, the wavelength near the boundary of the visible region 52 on the infrared region 53 side). The sensitivity generally decreases as the wavelength becomes shorter or longer than the value corresponding to this peak. As described above, the CCD camera has the sensitivity in the infrared region 53 while the sensitivity becomes lower as the wavelength becomes longer than about 780 nm. The CCD camera is connected to a display device (not shown) such as a liquid crystal display provided in the driver's seat via a computer (not shown) installed in the automobile C. Accordingly, information captured by the CCD camera in the infrared region 53 that cannot be visually recognized by the human naked eye is displayed as image information that can be visually recognized by the human naked eye on the display device.

  FIG. 3 is an explanatory diagram showing the characteristics of the filter 5. The horizontal direction in FIG. 3 represents the wavelength of the electromagnetic wave, and the wavelength becomes longer toward the right. The vertical direction represents the relative amount of electromagnetic waves with respect to the wavelength in the horizontal direction, and the relative amount increases as going upward. As shown in FIG. 3, an electromagnetic wave having a wavelength in a range of about 380 nm to about 780 nm among the electromagnetic waves is a visible region 52 that can be visually recognized by the human eye. By sensing the electromagnetic wave in the visible region 52 with the naked eye, the electromagnetic wave in this region can be visually recognized. This electromagnetic wave having a wavelength in the visible region 52 is called so-called visible light.

  Among the electromagnetic waves, a region having a wavelength shorter than the visible region 52 and a range from about 200 nm to about 380 nm is an ultraviolet region 51, and the electromagnetic waves in this region are called so-called ultraviolet rays. Further, among the electromagnetic waves, a region having a wavelength longer than that of the visible region 52 and a range from about 780 nm to about 100,000 nm is an infrared region 53, and the electromagnetic waves in this region are called so-called infrared rays. Since these ultraviolet rays and infrared rays are electromagnetic waves outside the range of the visible region 52, they cannot be directly recognized with the naked eye.

  Hereinafter, the operation of the vehicle infrared light projector in this embodiment will be described. The filament 12 of the halogen bulb 3 is turned on. Then, as shown in FIG. 1, a part of the light L from the filament 12 of the halogen bulb 3 is reflected by the main reflecting surface 10 of the main reflector 2. The reflected light L reflected by the main reflection surface 10 enters the projection lens 4 from the plane aspheric surface side of the projection lens 4 through the second focal point F2 of the main reflection surface 10. The reflected light L incident on the projection lens 4 is reflected (absorbed or cut) by visible light (visible light) having a wavelength of about 780 nm or less in the filter 5 on the convex aspheric surface side of the projection lens 4. Is transmitted through the convex aspherical side of the projection lens 4 to the outside through light (infrared light) LIR (dotted arrow in FIGS. 1 and 2) in the infrared region of about 780 nm or more. The infrared light LIR includes some red visible light (red light) LR (two-dot chain line arrow in FIG. 1). That is, some red light LR is also emitted to the outside from the convex aspheric surface side of the projection lens 4.

  On the other hand, the direct light from the filament 12 of the halogen bulb 3 passes through the opening 20 of the frame 7 and reaches the sub-reflecting surface 14 of the sub-reflector 6, and the sub-reflecting surface 14 projects the convex aspherical filter 5 of the projection lens 4. Reflected to the side. The reflected light reflected by the sub-reflecting surface 14 transmits light in the infrared region (infrared light) having a wavelength of about 780 nm or more through the convex aspherical filter 5 of the projection lens 4 and has a wavelength of about Light (visible light) LW (solid arrow in FIG. 1) in the visible region of 780 nm or less is reflected (absorbed or cut) and emitted to the outside from the convex aspheric surface side of the projection lens 4.

  In this way, a small amount of red light LR transmitted through the filter 5 from the convex aspheric surface side of the projection lens 4 and emitted to the outside together with the infrared light LIR is reflected by the filter 5 from the convex aspheric surface side of the projection lens 4. A large amount of visible light (that is, white light) LW emitted to the outside is mixed. Due to this color mixture, a small amount of red light LR is blurred by a large amount of visible light (white light) LW and disappears. The mixed color light is irradiated in front of the automobile C with a predetermined light distribution pattern as infrared light LIR not having red light LR and visible light (white light) LW, and is used for illumination of the night vision device for the vehicle. used.

  Hereinafter, the effect of the vehicle infrared light projector in this embodiment will be described. The vehicle infrared light projector in this embodiment includes the red light LR in the infrared light LIR that has passed through the filter 5, and the white color reflected by the sub-reflection surface 14 toward the filter 5 and reflected by the filter 5. Since the light LW is mixed almost entirely in the filter 5, the red light LR can be reliably diluted.

  In particular, the vehicle infrared light projector in this embodiment is such that the sub-reflector 6 is disposed outside the light projector 1 having a unit structure and is opposed to the projection lens 4. Light can be reliably reflected on the sub-reflecting surface 14 of the sub-reflector 6 toward the filter 5 side of the projection lens 4. To this end, the vehicle infrared light projector in this embodiment transmits a small amount of red light LR that passes through the filter 5 of the projection lens 4 and exits together with the infrared light LIR to the filter 5 of the projection lens 4. With the large amount of visible light (white light) LW reflected at, the colors can be mixed and reliably erased.

  Further, in the vehicle infrared light projector in this embodiment, the sub-reflector 6 is arranged outside the projection lens 4, that is, the unit-structure projector 1, so that the light from the halogen bulb 3 is opened to the opening of the frame 7. The unit 20 is passed through the outside of the light projecting device 1 having a unit structure. As a result, the infrared light projector for a vehicle in this embodiment can release the heat inside the light projector 1 having a unit structure to the outside, and can suppress the thermal influence.

  Further, in the vehicle infrared light projector according to this embodiment, the filter 5 is disposed on the light exit surface of the projection lens 4, so that the filter 5 is separated from the halogen bulb 3, and the main reflector 2, the projection lens 4, and It is located outside the space defined by the frame 7. As a result, the vehicle infrared light projector in this embodiment can reliably protect the filter 5 from the thermal shock of the halogen bulb 3.

  Furthermore, the vehicle infrared light projector in this embodiment reflects light from the halogen bulb 3 to the filter 5 side of the projection lens 4 by the sub-reflecting surface 14 and reflects the light by the filter 5 to the outside. Therefore, it is not necessary to provide the filter 5 on the convex aspheric surface of the projection lens 4 simply by providing the filter 5 with high accuracy. For this reason, the infrared light projector for a vehicle in this embodiment has a projection lens (40) with an infrared light transmission film (22) and an infrared light transmission film non-formation region (24F, 24G) with high accuracy. Compared with a conventional vehicle infrared light projector that needs to be formed and provided, the manufacturing cost can be reduced.

  Hereinafter, examples other than the embodiment will be described. In the vehicle infrared light projector according to this embodiment, the example in which the projector 1 is mounted on both the left and right sides of the front portion of the automobile C has been described. In the present invention, the automobile C of the projector 1 is used. There are no particular restrictions on the mounting location or the number of mounting. What is necessary is just to irradiate the front of the vehicle C with the infrared light LIR.

It is sectional drawing which shows the Example of the infrared light projector for vehicles concerning this invention. Similarly, it is explanatory drawing which shows a use condition. Similarly, it is explanatory drawing which shows the characteristic of an infrared-light transmissive filter.

Explanation of symbols

1 Projector (Infrared projector for vehicle)
2 Main reflector 3 Halogen bulb (light source)
4 Projection Lens 5 Filter 6 Sub Reflector 7 Frame 8 Inner Panel 9 Through Hole 10 Main Reflecting Surface 11 Flange 12 Filament 13 Window 14 Sub Reflecting Surface 15 Tube 16 Flange 17 Packing 18 Clip 19 Clip 20 Opening C Automobile F1 First focus F2 Second focus LR Red light LW Visible light (white light)
LIR Infrared light L Reflected light ZZ Optical axis

Claims (3)

In the projector-type infrared light projector for a vehicle that is installed in a vehicle and emits infrared light,
A main reflector having a main reflecting surface based on a spheroid;
A light source disposed near the first focal point of the main reflecting surface;
A projection lens;
A filter having an infrared light transmission characteristic that is disposed on a light exit surface of the projection lens and transmits infrared light among the light from the light source and transmitted through the projection lens to irradiate the outside.
A sub-reflector having a sub-reflecting surface that reflects light from the light source toward the filter;
An infrared light projector for a vehicle, comprising:   The vehicle infrared light projector according to claim 1, wherein the sub reflector is disposed outside the projection lens. The main reflector and the light source, the projection lens and the filter form a unit structure via a frame,
The sub reflector is provided on a member disposed outside the unit structure, and is disposed to face the projection lens,
The frame is provided with an opening that allows light from the light source to pass through the sub-reflection surface.
The infrared light projector for vehicles according to claim 1 characterized by things.

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