JPS5852190B2 - Specific object detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a specific object detection device for detecting specific objects such as schoolchildren and other people, bicycles, and automobiles.

Pedestrians, bicycles, and even cars are difficult to see in fog or at dusk.

They are also extremely difficult to see at night.

Therefore, in hopes of early detection, retroreflectors are attached to the tails of bicycles and cars so that they shine brightly when illuminated by headlights.

However, the use of the retroreflector is not limited to the above.

It is also used on utility poles, road shoulder signs, and more.

Therefore, not only school children, other people, or specific objects such as bicycles are recognized separately.

However, if such objects are discovered separately from other objects, bicycle riders become nervous and drive cautiously as they drive by and pass them.
Improves safety.

The present invention was made in view of such conventional problems, and allows school children, bicycles, etc. to be equipped with reflective plates, and to distinguish only the person or other specific object to which the reflective plate is attached from other general objects. The purpose of the present invention is to provide a detection device for a specific object that can be detected by an automobile and has improved safety.

The present invention will now be described with reference to embodiments shown in the figures.

In FIG. 1, the part indicated by A indicates the device part of one embodiment of the present invention, and B is a reflecting plate used in pair with this embodiment device A.

Device A is composed of a light emitter 1 and a light receiver 2.

In this embodiment, the floodlight 1 is an automobile headlamp or a hob lamp.

The light receiver 2 includes a polarizing plate 2a rotated by a motor M, a condensing lens 2b, and a light receiving element 2c.

The reflector B is extremely small and can be attached to a school child's school bag or hat, or is slightly larger so that it can be attached to the tail of a bicycle.

This reflection plate B is composed of a retroreflection section 3 and a polarization section 4, which reflect incident light in the direction of incidence using a prism effect.

Therefore, when light is being projected from the projector 1 and there is a reflector B in front of it, only the light polarized in a certain direction is transmitted by the polarizer 4 of the reflector B and the retroreflector 3
Here, the incident light is reflected in substantially the same direction as the direction in which it came and returns to the light receiver 2.

This light is reflected light polarized in a certain direction, so the lens 2
When the light is focused at point b and passes through the rotating polarizing plate 2a, it becomes a light beam whose intensity is alternated due to periodic changes in the polarization direction of the polarizing plate 2a.

This light flux whose intensity alternates is received by the light receiving element 2c.

Therefore, the light receiving element 2c outputs a current that changes like an alternating current as shown in FIG.

The output from the light receiving element 2c is processed by the electric circuit shown in FIG.

That is, the output of the light-receiving element 2e is amplified by the AC amplifier circuit 5, and then, if the amplitude of the AC is greater than the value set by the level setting circuit 6, the AC is converted into a pulse.

Next, the discrimination circuit 7 detects that the output from the level setting circuit 6 is a pulse output, and outputs an operation signal to the alarm circuit 8 as an annunciator.

The alarm circuit 8 is activated by this signal and notifies the driver that a specific object has been detected by means such as an alarm or lighting of a caution light.

However, for the reflected light from utility poles and retroreflectors on the roadside, these reflected lights have uneven polarization directions, so the light receiving element 2c only outputs a constant DC current. Therefore, the alarm circuit 8 is not activated, and the object is distinguished from a specific object.

As described above, the present invention is equipped with a light emitter, a polarized light receiver, and a notification means that operates based on the light reception signal of the polarized light receiver. By attaching a polarized reflector, it is possible to detect specific objects by detecting the polarized reflected light from the polarized reflector, and for this reason, it is possible to detect specific objects such as school children or bicycles that require special attention from drivers in fog or other places. It can be easily spotted even at night, and has the advantage of ensuring safe driving.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram of an embodiment of the present invention, FIG. 2 is a waveform diagram of the received light output of the light receiving element in the embodiment, and FIG. 3 is an electric circuit diagram of the embodiment. 1... Emitter, 2... Receiver, 8...
...Alarm circuit as a means of notification.

Claims (1)

[Claims] 1. A floodlight, a retroreflector with a polarizing plate layered on its surface,
A specific object detection device comprising a light receiver that detects polarized light and a notification means that operates based on a polarized light reception signal of the light receiver.