JPH06191346A - Automotive headlamp system - Google Patents

Abstract

PURPOSE:To provide beam intensity according to the presence of a vehicle running in the opposite direction and running speed with the basic axis direction of a beam kept constant regardless of uneven loading, and change the orientation of the beam according to the advance direction. CONSTITUTION:Leveling of the basic axis of a prescribed beam, beam distribution and beam intensity are computed according to the elevation angle, running speed and traveling direction of own vehicle, and the presence of a vehicle running in the opposite direction by a light distribution control circuit 9 which receives signals detected by a detection sensor 7 for vehicle running in the opposite direction, a detection sensor 10 for posture change, a speed sensor 11 and a detection sensor 12 for steering rotational angle. Using computed results, a light shutter driving circuit 8 outputs a matrix signal for forming a desired optical image to a light shutter 5, and an optical image for irradiating a prescribed distributed beam to a forward road based on the position of the basic axis of the prescribed beam is formed at the light shutter 5 to be irradiated to the forward road through a collimator lens 4 by a light source 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention corrects a beam deviation of a headlight due to load imbalance, and adjusts the beam intensity and the beam azimuth according to a change in traveling speed and a course to illuminate a road ahead. Regarding the lighting system.

[0002]

2. Description of the Related Art A conventional automobile headlight system comprises a two-beam system including a traveling beam and a passing beam system. A lever switch provided in the vicinity of a steering wheel is used when traveling on a road with a large amount of traffic or at a low speed. The passing beam was turned on in the case of, and the running beam was turned on when traveling on a road with low traffic or when traveling at high speed. Therefore, there are many drivers who forget to switch to the passing beam after turning on the traveling beam once, which causes a problem of giving a strong glare to an oncoming vehicle.

Further, even when the vehicle is running with the passing beam turned on, the beam is directed upward from a predetermined direction due to load imbalance, giving a driver of an oncoming vehicle a strong glare. When traveling with the traveling beam, there is also a problem that the beam direction is directed downward from a predetermined direction due to load imbalance and the distant area is not sufficiently illuminated. For this,
Some leveling devices have been developed that adjust the beam axis according to the load deviation (for example, Automotive Technology, Vol. 4).
5, No. 10, 1991, P31), this method is a mechanical one that adjusts the beam axis by displacing the reflecting mirror, the structure is complicated, the followability is not sufficient, and it corresponds to only the passing beam. It was a thing.

A system for directing the light distribution shape to the left and right according to the rotation angle (traveling direction) of the steerer ring has been put into practical use in some parts (for example, Automotive Technology, Vol. 45, No. 10, 1).
991, P31), which concerns fog lights,
Moreover, the rotary drive is mechanically transmitted to the fog lamp to mechanically swing the lamp to the left and right, and it has no leveling function.

There are two types of headlights, a headlight called a two-light type and a headlight called a four-light type. As an example, in the two-light type, an automotive light bulb called H4 provided with two filaments is used. When the traveling beam is used, both filaments are turned on, and when the beam is a passing beam, only one is turned on. . Further, a light-shielding plate is provided in the vicinity of the filament that is turned on during the passing beam so that light directed upward is cut off and the glare is limited. For this reason, the glare is properly limited when the load is normal, but only half of the luminous flux of the lamp is used because the light shielding plate is used.
It was a system with low efficiency.

The four-lamp type is composed of a lamp for exclusive use of a passing beam and a lamp for exclusive use of a traveling beam. Among them, the lamp for a passing beam is an automotive light bulb having a single filament called H3C and an elliptical reflector. And a collimator lens are combined, but this also has a light shielding plate between the collimator lens and the reflecting mirror to reduce glare,
It was inefficient. Further, since the light blocking plate cuts the light in the upward direction, the cut-off line of the light becomes too clear, which makes it difficult to see the road signs in the upper front.

[0007]

As described above, in the conventional headlight system, it is necessary to further limit the glare to the elderly people who are expected to increase in the future, even though the load is reduced. There was a problem that it was dazzling due to uneven weight. In addition, it is necessary to use energy saving bulbs, but in terms of glare, high efficiency and high brightness discharge lamps cannot be used, so there is no choice but to use low efficiency bulbs. Moreover, there is a problem that half of the luminous flux of the lamp is not used at all for the light shielding plate. Furthermore, there was a problem that the lighting could not be adequately coped with for the change of course. Although some means for solving these problems have been developed, all of them are intended to solve one problem, and their configurations are mechanical and complicated.

In view of such conventional problems, the present invention provides a beam intensity according to the presence or absence of an oncoming vehicle and the traveling speed while keeping the basic axis direction of the beam constant regardless of the uneven load, and the path of travel. An object of the present invention is to provide an automobile headlamp system capable of displacing a beam azimuth according to a direction.

[0009]

In order to solve the above problems, an automobile headlamp system according to the present invention includes a light source, an optical shutter composed of a variable light transmittance element, and an optical shutter for forming an optical image. A drive circuit unit and a projection unit for projecting an optical image formed on the optical shutter by the drive circuit unit onto the front road in order to irradiate the front road with a beam having a predetermined light distribution, are provided with light from a light source. The beam is converted into a beam having a predetermined light distribution, and the road ahead is illuminated.

Further, as a sensor, a sensor A for detecting a posture change of elevation / depression due to load bias of the vehicle, a traveling speed detection sensor B, a sensor C for detecting a steering rotation angle, and an approaching vehicle are detected. A sensor D is provided, and the detection signals of the sensors A, B, C, and D are received, and a predetermined light distribution corresponding to the elevation displacement of the own vehicle, the traveling speed, the displacement in the traveling direction, and the presence or absence of an oncoming vehicle. Equipped with a light distribution control circuit that calculates the leveling of the beam and the basic axis of the beam, the output signal from the light distribution control circuit is received by the drive circuit section of the optical shutter, and the specified light distribution is based on the position of the basic axis of the beam. The optical image for obtaining the beam is formed on the optical shutter, and this optical image is projected on the road ahead by the projection unit.

The light source is a high-intensity discharge lamp, the optical shutter is a liquid crystal or PLZT, and the optical shutter is provided with an ultraviolet cut filter for cutting ultraviolet rays from the high-intensity discharge lamp. is there.

[0012]

With the above construction, a predetermined optical image is formed on the optical shutter by the light source, the optical shutter and the drive circuit section thereof, and the formed optical image is projected onto the road ahead as a beam of predetermined light distribution by the projection section. Is irradiated. In addition, since the basic axis of the beam can be kept constant by equipping the sensor and the light distribution control circuit that detect the posture change of the elevation due to the load deviation, the deviation of the vertical direction of the beam due to the load deviation is eliminated, and No more giving glare.
Further, by providing the sensor for detecting the presence / absence of the oncoming vehicle and the speed sensor, the reaching distance of the beam can be controlled according to the presence / absence of the oncoming vehicle and the traveling speed. Further, by providing the rotation angle sensor of the steering, the azimuth of the beam can be controlled to be displaced according to the traveling direction.

Further, by using a high-intensity discharge lamp as the light source, the system efficiency is increased, and the reach distance of the beam can be extended to more than twice that of the conventional automobile bulb. Also, by configuring the optical shutter with liquid crystal or PLZT,
It is possible to suppress light loss with a small amount and form an arbitrary optical image. Further, by providing the optical shutter with an ultraviolet ray cut filter, it is possible to remove ultraviolet rays harmful to the human body emitted from the high-intensity discharge lamp.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an automobile headlight system of the present invention, and FIGS. 2 and 3 are diagrams showing examples of optical images formed on the optical shutter of FIG.

In FIG. 1, 1 is a light source, 2 is a projection unit, and 3
Is a reflecting mirror that constitutes the projection unit 2, 4 is a collimator lens that constitutes the same projection unit 2, 5 is an optical shutter that forms an optical image, 6 is an ultraviolet cut filter, 7 is an oncoming vehicle detection sensor, and 8 is an optical shutter drive A circuit portion, 9 is a light distribution control circuit, 10 is a posture change detection sensor, 11 is a speed sensor, and 12 is a steering rotation angle detection sensor. In this embodiment, liquid crystal is used as a light transmittance variable element for forming an optical image, which is provided in the optical shutter 5.

In the vehicle headlight system including the above components, the relationship between these components and the operation thereof will be described. The light emitted from the light source 1 becomes substantially parallel light by the reflecting mirror 3, illuminates the optical shutter 5, and projects the optical image formed on the optical shutter 5 through the collimator lens 4 onto the road ahead.

The light distribution control circuit 9 which receives the detection signals from the oncoming vehicle detection sensor 7, the attitude change detection sensor 10, the speed sensor 11, and the steering rotation angle detection sensor 12 causes the vehicle's depression / elevation angle, traveling speed and traveling direction. Further, the leveling of the basic axis of the desired beam, the beam distribution, and the beam intensity are calculated corresponding to the presence or absence of the oncoming vehicle. The calculated result is used as an output signal for the drive circuit unit 8 of the optical shutter.
Is input to the optical shutter drive circuit unit 8 and converted into a matrix signal for forming a desired optical image on the optical shutter 5 and output. As a result, the optical shutter 5 forms an optical image for irradiating the front road with a beam having a predetermined light distribution based on the position of the basic axis of the predetermined beam, and this optical image formed on the optical shutter 5 is collimator lens. 4 is projected on the road ahead.

In this embodiment, the projection unit 2 is replaced by the reflecting mirror 3.
However, another means such as irradiating the light from the light source 1 with the optical shutter 5 by using an optical fiber instead of the reflecting mirror may be used. Further, although the liquid crystal is used as the light transmittance variable element forming the optical shutter 5, PLZT may be used.

FIG. 2 shows, from the position of the optical shutter 5, an optical image formed in a mosaic shape on the optical shutter as a passing lighting beam and a state in which the optical image is projected in front of a flat straight road. It is the figure represented as a perspective view at the time. In FIG. 2, 5 is an optical shutter, and 13 is a basic axis of the beam axis, which corresponds to the positions of V = 0 ° and H = 0 °. 14a is a lane mark on the shoulder side of the own lane, 14b is a center line of the lane, and 14c is a lane mark on the shoulder side of the overtaking lane. 15a, 15b, 15c, 15d, 1
5e is a partial optical image forming an optical image, and the partial optical image 15a is set to have a light transmittance of 40%.
A luminous intensity of 2500 cd is obtained. 15b has a light transmittance of 26%, and 15c has a light transmittance of 13%.
15d is set to 7%, 15e is set to 3%, and others are set to 0%.

FIG. 3 shows that there is no oncoming vehicle and the traveling speed is 80 km / h.
6 is an optical image of a traveling beam lighting mode state when the value exceeds the threshold value. In this case, the light transmittance of 16a is set to 80%, and the luminous intensity of 25000 cd is obtained at that time. 16b has a transmittance of 65%,
The transmittance is set to 33% for c, 17% for 16d, 8% for 16e, and 0% for others.

2 and 3 show examples of optical images of the passing beam and the traveling beam formed on the optical shutter 5.
In addition to this, another optical image such as an optical image of a town beam may be formed.

The optical images formed as shown in FIGS. 2 and 3 are
Even if the basic axis of the beam axis is raised due to the load bias, the basic axis of the beam axis is always V = 0 by the posture change detection sensor 10.
The optical image is displaced downward so as to be in the azimuth of .degree., H = 0.degree., And when the course is taken to the left, for example, the steering rotation angle sensor 12 displaces the optical image to the left.

[0023]

As described above, according to the present invention, an optical image is formed by an optical shutter, and the formed optical image is projected to a road ahead, so that the oncoming vehicle can be driven without causing glare. Accordingly, since it is possible to illuminate the road range such as distant, near, left side and right side with light of sufficient intensity, the effect of the headlight can be fully utilized. Furthermore, energy can be saved by using a highly efficient high-intensity discharge lamp.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a vehicle headlight system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an optical image formed on an optical shutter in a low beam mode in the vehicle headlight system.

FIG. 3 is a diagram showing an example of an optical image formed on an optical shutter in a traveling beam mode in the vehicle headlight system.

[Explanation of symbols]

 1 Light Source 2 Projection Unit 3 Reflector 4 Collimator Lens 5 Optical Shutter 6 UV Cut Filter 7 Oncoming Vehicle Detection Sensor 8 Optical Shutter Drive Circuit Section 9 Light Distribution Control Circuit 10 Attitude Change Detection Sensor 11 Speed Sensor 12 Steering Rotation Angle Detection Sensor

Claims (6)

[Claims] 1. A light source, an optical shutter composed of a variable light transmittance element to form an optical image, a drive circuit portion of the optical shutter, and an optical image formed on the optical shutter by the drive circuit portion on a front road. A vehicle headlight system having a projection unit for projecting. 2. A sensor A for detecting a posture change of elevation and depression due to load deviation of the vehicle, a traveling speed detection sensor B, a sensor C for detecting a rotation angle of the steering wheel, and a sensor D for detecting approach of an oncoming vehicle. Receiving the detection signals of the sensors A, B, C, D, and the beam distribution corresponding to the elevation angle of the vehicle, the traveling speed, the direction of travel, and the presence or absence of an oncoming vehicle, It has a light distribution control circuit that calculates the intensity of the beam and the leveling of the basic axis of the beam axis, and the drive circuit unit of the optical shutter receives the output signal of the light distribution control circuit,
An optical image is formed on the optical shutter for irradiating the front road with a beam of a predetermined light distribution based on the position of the basic axis of the predetermined beam, and the optical image is projected onto the front road by the projection unit. Item 3. The vehicle headlight system according to item 1. 3. The vehicle headlamp system according to claim 1, wherein the light source is a high-intensity discharge lamp. 4. The vehicle headlight system according to claim 1, wherein the optical shutter is composed of a liquid crystal element. 5. The vehicle headlight system according to claim 1, wherein the optical shutter is composed of PLZT. 6. The vehicle headlight system according to claim 1, wherein the optical shutter has an ultraviolet ray cut filter characteristic.