JPH0343061Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention uses a light shutter that operates at high speed to intermittently block the light from an oncoming light, for example, the headlight of an oncoming vehicle. The present invention relates to an anti-dazzling device that prevents dazzling caused by light from a headlamp.

[Technology background] When cars pass each other at night, if the oncoming car does not switch the optical axis of its headlights downward, the driver may be dazzled by the light from the oncoming car's headlights. There is a problem. Conventionally, as a device for preventing such dazzling, for example,
As seen in Japanese Patent Publication No. 101526, a polarizing plate is used to block light from the headlights of an oncoming vehicle, or Japanese Patent Application Laid-Open No. 49-72830,
As seen in Japanese Patent No. 50-138526, there is a known structure in which a liquid crystal panel is used to block light from the headlights of oncoming vehicles. However, such conventional anti-dazzle devices have the disadvantage that, for example, those using polarizing plates cannot be effective unless all cars are equipped with polarizing plates. In the case of vehicles, when the light from the headlights of an oncoming vehicle is blocked, the overall visibility in front of the vehicle becomes dark, making it difficult to see road irregularities and obstacles (pedestrians, etc.) that should normally be visible. There is a risk of misunderstanding.

Therefore, the inventors of this application first applied for patent application No. 59-1718.
In this issue, an on-vehicle floodlight emits visible light to a predetermined area in front of the vehicle while intermittent or changing intensity at a high speed that appears as continuous light to the human eye;
an on-vehicle light shutter plate that is arranged to face a predetermined area in front of the vehicle and that is controlled to a high transmittance state in synchronization with an irradiation period or a strong illuminance period of light projected from the on-vehicle floodlight; by
A new anti-dazzling device is presented that utilizes Talbot's law to reliably prevent dazzling from the headlights of oncoming vehicles without impairing the driver's forward visibility.

As mentioned above, the anti-dazzling device proposed by the present inventors uses an on-vehicle floodlight that intermittents or changes the intensity of visible light at such high speed that it appears to the human eye as continuous light. In other words, conventional vehicle lighting configurations include those in which a rotating slit plate is placed in front of a single light source such as a halogen lamp that emits continuous light, and those in which a single discharge type light source such as a xenon tube is used to emit intermittent light. We are thinking of things that will make it happen.

[Problems to be solved by the invention] However, in the above-mentioned vehicle lights,
Based on Talbot's law, in order to ensure sufficient illuminance for a given irradiation area, the luminous intensity of the lamp itself must be made sufficiently large, so it is necessary to In the case of lamps that use a part of the light from the light source, which is arranged with a rotating slit position, the light usage efficiency is poor (if the slits are used to project and block light at a duty ratio of 50%, The light usage efficiency is also 50%), and the amount of wasted light increases.

In addition, in this type of lamp, the blinking cycle of the light source or the intensity cycle of the irradiation intensity is very short (for example, about 1/100 seconds), so a large voltage is applied instantaneously to emit light as described above. In the case of a discharge type light source that emits light intermittently, problems such as heat generation in the discharge tube and thermal deterioration of the electrodes become significant.

[Means for Solving the Problems] The present invention has been made in view of the above problems, and is a vehicle lamp that can be applied to the above-mentioned anti-dazzle device, has good light usage efficiency, and has excellent durability. In order to achieve this purpose, the present invention aims to provide a vehicle lighting device that can provide a vehicle light with a predetermined amount of light directed toward a predetermined monitoring area using an anti-dazzling device. Irradiation by multiple light sources is performed sequentially, and between each irradiation there is a stop period in which no irradiation is performed from any of the light sources, and the interval between each irradiation is set at a certain level to the human eye. an irradiation control means that repeats at a period visible to the amount of light; and an irradiation control means disposed between a supervisor who monitors the monitoring area and the monitoring area, and a predetermined transmittance during a period in which irradiation is performed by one of the light sources, and the stoppage. During the period, the light shutter has a transmittance lower than the predetermined transmittance.

[Embodiments of the invention] Hereinafter, embodiments of the invention will be described based on the drawings.

FIG. 1 is a diagram showing an example of the conceptual structure of a vehicle lamp as a light source in the anti-dazzle device of the present invention. In the figure, a plurality of xenon tubes B1, B2, ..., Bn (discharge tubes) serving as light sources are provided, and each xenon tube B1 to Bn has a reflector R1 to Rn.
is installed. Then, the xenon tubes B1 to Bn reflected by the respective reflectors R1 to Rn
The lights from F1 to Ln are focused by the lenses L1 to Ln, respectively, and each of the focused lights is further transmitted to the optical fiber F1.
It is now guided by Fn. Further, 10 indicates each optical fiber F1 to F1 as described above.
A lens 11 is for condensing each light beam guided by Fn, and an optical fiber 11 is for further guiding the light condensed by this lens 10. It is processed so that the guided light is diffusely emitted (for example, a ball lens is provided). The tip 11a of the optical fiber 11 is disposed, for example, at the front of the vehicle, and the light emitted from this is reflected by the reflector 12 and directed to a predetermined area in front of the vehicle by the lens 13. The light is now irradiated with the following light distribution characteristics.

FIG. 2 is a block diagram showing an example of the case where the lamp shown in FIG. 1 is applied to a vehicle equipped with an anti-dazzling device that intermittently cuts off dazzling light at high speed using a light shutter. In this example, 10 xenon tubes (n=10) are used as light sources.

In the figure, 21 is a predetermined period, for example 100
An oscillation circuit 22 that outputs trigger pulses at a period corresponding to Hz is reset every time the count value reaches 10 by counting the trigger pulses from the oscillation circuit 21, and each output port P is reset every time the count value reaches 10.
Decimal counters, 23a, 23b, . . ., which sequentially output switching pulse signals from 1 to P10.
..., 23j are each output port P of the decimal counter 22
1 to P10 are monostable multivibrators (hereinafter simply referred to as monomultis), and each monostable multivibrator 23a to 23j generates a pulse signal of a predetermined width each time the output pulse from the decimal counter 22 is input. is now output. In addition, 24a, 24b, ..., 24j are xenon tubes B1 to B that serve as the light source of the lamp shown in FIG.
10, and each drive circuit 24a to 24j is a drive circuit for making the monomulti 23a to 2 emit light.
Each time a pulse signal of a predetermined width is input from 3j, the potential charged so far is transferred to each xenon tube B1 to B.
10.

On the other hand, 25 is a monostable multivibrator (hereinafter simply referred to as mono-multi) that outputs a pulse signal of a predetermined width each time a trigger pulse from the oscillation circuit 21 is input, and 26 is a monostable multivibrator (hereinafter simply referred to as mono-multi) that outputs a pulse signal of a predetermined width each time a trigger pulse from the oscillation circuit 21 is input. A light shutter 30 as described below
The light shutter 30 is controlled to have a high transmittance state when any of the xenon tubes B1 to B10 is lit.

Here, the optical shutter 30 is installed inside the vehicle so as to cover the limited field of view of the driver of the vehicle, and its specific structure is, for example, as shown in FIG. 3. That is,
The PLZT ceramic plate 33 is sandwiched between two polarizing plates 34a and 34b whose polarization planes are perpendicular to each other, and this state is further sandwiched between protective glass plates 35a and 35b and stored in the casing 31, as shown in FIG. An optical shutter 30 as shown in Fig. 3 has been completed. still,
Electrode lead wire 36a of PLZT ceramic plate 33,
36b passes through a flexible tube 32 provided in the housing 31 and is drawn out to the outside (see FIG. 4).

Next, the operation of the apparatus shown in FIG. 2 will be explained.

When a trigger pulse with a frequency of, for example, 100Hz is output from the oscillation circuit 21, the monomulti 25 and drive circuit 2 operate in synchronization with this trigger pulse.
6, the optical shutter 30 is controlled to have a high transmittance for a time determined by the output pulse width from the monomulti 25 every time the trigger pulse is output. The duty ratio of the on/off (high transmittance/low transmittance) operation of the optical shutter 30 is, for example, about 1/30. When the light from the headlight of an oncoming vehicle is viewed through the optical shutter 30, which alternately repeats a high transmittance state and a low transmittance state, the light from the headlight of an oncoming vehicle is darker than the actual brightness of the headlight according to Talbot's law. This will prevent you from being dazzled by the headlights of the oncoming vehicle as much as possible.

On the other hand, every time the trigger pulse from the oscillation circuit 21 is input to the decimal counter 22, the decimal counter 2
Pulse signals are sequentially switched and output from each of the two output ports P1 to P10. That is, the signal output cycle from each output port P1 to P10 of the decimal counter 22 is ten times the output cycle of the trigger pulse from the oscillation circuit 21. Then, the xenon tubes B1 to B10 repeat blinking in sequence by the monomultis 23a to 23j and drive circuits 24a to 24j, which operate in synchronization with the pulse signals from the respective output ports P1 to P10 of the decimal counter 21. At this time, the light emission period of each xenon tube B1 to B10 is determined by each output port P1 of the decimal counter 22.
Similar to the signal output period from P10 to P10, it is 10 times the output period of the trigger pulse from the oscillation circuit 21, and each of the xenon tubes B1 to B10 repeats blinking at 10 Hz. The light from the xenon tubes B1 to B10, which repeat blinking in sequence in this way, passes through the lenses L1 to L10, the optical fibers F1 to F10, and is further transmitted to the lens 10 and the optical fiber 1.
1 from the tip 11a of the optical fiber 11. At this time, each xenon tube B1 to B
10 is guided in parallel to the tip portions 11a of the optical fibers 11.
From a, 100Hz (10Hz×10), that is, oscillation circuit 2
Light will be emitted in synchronization with the trigger pulse from 1. Therefore, when the optical shutter 30 is in a high transmittance state, light is emitted from the tip 11a of the optical fiber 11, while when the optical shutter 30 is in a low transmittance state, no light is emitted from the tip 11a during the stop period. Therefore, this optical fiber 11
When the light from the tip 11a is reflected by the reflector 12 and illuminates a predetermined area in front of the vehicle through the lens 13, the irradiated light reflected by an object in the area passes through the light shutter 30. This will be directly visible to the driver. Therefore, the driver can see objects within the area under normal brightness. In this case, the luminous intensity of each xenon tube B1 to B10 is 100Hz according to Talbot's law.
The brightness is set to be felt to be the same as that of a normal headlamp when illuminated by a light source.

As mentioned above, according to this embodiment, when focusing on one xenon tube, the light emission period is 10 times that of a conventional lamp using a single xenon tube, so the charging time after light emission is The xenon tube becomes longer, enabling more efficient light emitting operation, and the cooling time after the light emission becomes longer, reducing the amount of heat generated by the xenon tube and reducing the deterioration of the electrodes due to heat. be able to.

Furthermore, even when using the anti-dazzle device as a headlamp, the xenon tubes, lenses, and optical fibers that serve as the light source can be placed rearward from the front of the vehicle, making it possible to place them behind the front of the vehicle. There is no need to make any particular changes to the design of the headlights.

In addition, PLZT, which constitutes the main part of the optical shutter 30,
A similar optical shutter can be constructed by replacing the ceramic plate 33 with a liquid crystal plate.

[Effects of the invention] As explained above, according to the invention, a plurality of light sources are sequentially turned on after a stop period in which no light source emits light between each irradiation, and the interval between each irradiation is is performed at a period that appears to be a constant amount of light to the human eye, and the light shutter has a predetermined transmittance during the period when irradiation is being performed by one of the light sources, and the transmittance is lower than the predetermined transmittance during the stop period. I did it like that.

Therefore, while ensuring the brightness of the monitoring area monitored by the person concerned, it is possible to prevent dazzling from oncoming lights, such as the headlights of oncoming cars, and to reduce the usage rate of light emitted from the light source. Furthermore, the durability of the light source can be improved.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the conceptual structure of a vehicle lamp according to the present invention, and Fig. 2 is a diagram showing an example of a conceptual structure of a vehicle lamp according to the present invention. A block diagram showing an example of the case where the lamp shown in FIG. 1 is applied, and FIGS. 3 and 4 are perspective views showing an example of a specific structure of the light shutter shown in FIG. 2. B1 to Bn...Xenon tube, R1 to Rn...
Reflector, L1 to Ln... Lens, F1 to
Fn...Optical fiber, 10...Lens, 11...
Optical fiber, 12... Reflector, 13... Lens, 21... Oscillation circuit, 22... Decimal counter,
23a to 23j...monostable multivibrator (mono multi), 24a to 24j...drive circuit,
25... Monostable multivibrator (mono multi), 26... Drive circuit, 30... Optical shutter,
31... Housing, 33... PLZT ceramic board, 3
4a, 34b...polarizing plate, 35a, 35b...protective glass plate.

Claims (1)

[Scope of Utility Model Registration Claim] A plurality of light sources that intermittently irradiate a predetermined amount of light toward a predetermined monitoring area, and a plurality of light sources that irradiate a predetermined monitoring area sequentially and do not use any of the light sources between each irradiation. an irradiation control means that has a stop period during which no irradiation is performed and repeats the interval between each irradiation at a cycle that appears to be a constant amount of light to the human eye; and between a monitor who monitors the monitoring area and the monitoring area. a light shutter that has a predetermined transmittance during a period in which the light source is arranged and is illuminated by one of the light sources and has a transmittance lower than the predetermined transmittance during the stop period; Device.