Description of the Prior Art Typically, a number of traffic signaling devices are installed at a crossroad to regulate the passing of vehicles and pedestrians in different directions while achieving a safe and smooth flow of traffic. There may be a possibility of accidents when a vehicle passes through a crossroad in a desired direction while violating a traffic signal contrary to the running direction of the vehicle. However, drivers often violate traffic regulations, for example, when in haste to reach a destination. This is a main factor of frequent traffic accidents. Therefore, it is necessary to continuously monitor vehicles passing along a road, in particular, through a crossroad, to detect vehicles violating traffic regulations. However, great labor and a great deal of or expensive equipment

are required to achieve such a purpose. Furthermore, the detection of a violation of traffic regulations is made only based on the individual determination of a traffic regulator without any real evidence. For this reason, a dispute between the driver and traffic regulator may occur. In particular, such a dispute may frequently occur at night or under bad weather conditions in which it is difficult to accurately detect a violation of such traffic regulations.

SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above mentioned problems, and an object of the invention is to provide an automatic traffic monitoring method for picking up images of vehicles passing through a crossroad while violating traffic regulations, thereby accurately detecting those vehicles.

Another object of the invention is to provide an automatic traffic monitoring apparatus for effectively carrying out the automatic traffic monitoring method.

In accordance with one aspect, the present invention provides an automatic traffic monitoring method for detecting vehicles passing through a crossroad while violating traffic regulations comprising the step of: (a) determining whether or not a traffic signaling device is switched to generate a stop

signal; (b) returning to the step (a) when it is determined at the step (a) that the traffic signaling device is not switched to generate a stop signal, while emitting a laser beam toward a street of the crossroad in such a fashion that the emitted laser beam reaches a region of the street arranged beyond a stop line provided at the street and toward a direction opposite to the direction of the emitted laser beam while being spaced from the stop line by a desired distance when it is determined at the step (a) that the traffic signaling device is switched to generate a stop signal; (c) determining whether or not there is a vehicle sensing signal generated in response to a reflection of the laser beam by a vehicle passing the stop line in spite of the stop signal; (d) returning to the step (a) when it is determined at the step (c) that there is no vehicle sensing signal while, when it is determined at the step (c) that there is a vehicle sensing signal generated in response to a reflection of the laser beam by a vehicle passing the stop line in spite of the stop signal, picking up an image of the vehicle; and (e) storing the picked-up image.

In accordance with another aspect, the present invention provides an automatic traffic monitoring apparatus for detecting vehicles passing through a crossroad while violating traffic regulations comprising: a vehicle sensor for emitting an optical signal toward a street of the crossroad in such a fashion that the emitted optical signal reaches a region of

the street arranged beyond a stop line provided at the street and toward a direction opposite to the direction of the emitted optical signal while being spaced from the stop line by a desired distance, the vehicle sensor generating a vehicle sensing signal, indicative of the fact that there is a vehicle in the street region, upon receiving an optical signal resulting from a reflection of the emitted optical signal; a control unit for receiving the vehicle sensing signal generated from the vehicle sensor, thereby generating an image pick-up signal; a camera for receiving the image pick-up signal from the control signal, thereby picking up an image of a front part of the sensed vehicle; and a memory unit for storing the picked-up image.

BRIEF DESCRIPTION OF THE DRAWINGS The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description when taken in conjunction with the drawings, in which: Fig. 1 is a schematic view illustrating an automatic traffic monitoring apparatus of the present invention under the condition in which it is installed at a crossroad provided with pedestrian crossings; Fig. 2 is a schematic view illustrating the automatic

traffic monitoring apparatus of the present invention under the condition in which it is installed at a crossroad not provided with any pedestrian crossing; and Fig. 3 is a flow chart illustrating an automatic traffic monitoring method carried out using the automatic traffic monitoring apparatus in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, the present invention will be described in detail, in conjunction with the annexed drawings.

Fig. 1 schematically illustrates an automatic traffic monitoring apparatus of the present invention under the condition in which it is installed at a crossroad provided with pedestrian crossings. Fig. 2 schematically illustrates the automatic traffic monitoring apparatus of the present invention under the condition in which it is installed at a crossroad not provided with any pedestrian crossing. In addition, Fig. 3 illustrates sequential processing steps of an automatic traffic monitoring method carried out using the automatic traffic monitoring apparatus in accordance with the present invention.

The automatic traffic monitoring apparatus of the present invention will be described hereinafter, in conjunction with Figs. 1 and 2.

Typically, crossroads, have stop lines and pedestrian

crossings, or at least stop lines. When a stop signal is generated from a traffic signaling device installed at a crossroad, vehicles, which run at the crossroad, should stop in response to the stop signal without passing a pedestrian crossing provided at the crossroad or a stop line where no pedestrian crossing is provided. The automatic traffic monitoring apparatus is adapted to detect vehicles passing along a road, in particular, through a crossroad, while violating traffic regulations.

As shown in Figs. 1 and 2, the automatic traffic monitoring apparatus of the present invention includes a camera 22 mounted to a traffic signaling device 30 installed at a crossroad, and a vehicle sensor 26 mounted to the traffic signaling device in the vicinity of the camera 22. The camera 22 and vehicle sensor 26 are electrically connected to a control unit 20 so that they are controlled by the control unit 20. The control unit 20 is installed on in an area alongside the road in the vicinity of a support bar for supporting the traffic signaling device 30, so that it can be easily manipulated by a user such as a traffic regulator.

Typically, the traffic signaling device 30 is periodically switched to generate desired traffic signals for regulating the passing of vehicles and pedestrians in different directions while achieving a safe and smooth flow of traffic.

Accordingly, the control unit 20 should be configured to

rapidly sense the switching of traffic signals.

The control unit 20 serves to control the vehicle sensor 26 to emit laser beams simultaneously with the generation of a stop signal from the traffic signaling device 30. The vehicle sensor 26 has a light emitting element (not shown) for emitting laser beams toward a street in such a fashion that they reach a region 50 of the street arranged beyond a stop line 12 provided at the street and toward the vehicle sensor 26 while being spaced from the stop line 12 by a desired distance. Where a pedestrian crossing 10 is provided at the street beyond the stop line 12, as shown in Fig. 1, the light emitting element of the vehicle sensor 26 is configured to allow laser beams emitted therefrom to reach a region on the pedestrian crossing 10 corresponding to the street region 50.

On the other hand, where there is no pedestrian crossing, as shown in Fig. 2, the light emitting element of the vehicle sensor 26 is configured to allow laser beams emitted therefrom to reach the street region 50 beyond the stop line 12 while being spaced from the stop line 12 by a desired distance.

In either case of Fig. 1 or Fig. 2, the laser beams emitted from the light emitting element of the vehicle sensor 26 reach the street region 50 while passing a street region 40 (Fig. 1) or a street region 60 (Fig. 2) arranged beyond the pedestrian crossing 10 or the street region 50. If there is a vehicle in the street region 40 or 60 or the street region 50,

the emitted laser beams are reflected by the vehicle, so that a part of the reflected laser beams is sensed by a light receiving element (not shown) included in the vehicle sensor 26. Based on the laser beam sensing result of the light receiving element, the vehicle sensor 26 generates a vehicle sensing signal indicative of the fact that there is a vehicle in the street region 40 or 60 or the street region 50 while violating traffic regulations. The vehicle sensing signal from the vehicle sensor 26 is transmitted to the control unit 20 which, in turn, activates the camera 22 to pick up an image of the front part of the sensed vehicle. Thus, it is possible to accurately detect the vehicle violating traffic regulations, based on the picked-up image of that vehicle. In order to store the image picked up by the camera 22, the automatic traffic monitoring apparatus also includes a memory unit 24.

Now, an automatic traffic monitoring method, which is carried out using the above mentioned automatic traffic monitoring apparatus in accordance with the present invention, will be described in conjunction with Fig. 3.

In accordance with the automatic traffic monitoring method of the present invention, as shown in Fig. 3, it is first determined whether or not the traffic signaling device 30 is switched to generate a stop signal (Step S1). This determination is achieved by the control unit 20. When it is determined at step Sl that the traffic signaling device 30 is

not switched to generate a stop signal, step Sl is repeatedly executed. On the other hand, when the traffic signaling device 30 is switched to generate a stop signal, the control unit 20 controls the vehicle sensor 26 to emit laser beams (Step S2).

The laser beams, which are emitted from the vehicle sensor 26 in response to the generation of the stop signal, direct to the street region 50 beyond the stop line. If there is a vehicle in the street region 40 or 60 or the street region 50, the emitted laser beams are reflected by the vehicle, so that a part of the reflected laser beams is sensed by the vehicle sensor 26. Based on the sensed laser beam, the vehicle sensor 26 generates a vehicle sensing signal indicative of the fact that there is a vehicle in the street region 40 or 60 or the street region 50 while violating traffic regulations.

Accordingly, at step S3, it is determined whether or not the vehicle sensor 26 generates a vehicle sensing signal. When it is determined at step S3 that there is no vehicle sensing signal generated from the vehicle sensor 26, the control procedure returns to step Sl to execute again step Sl. That is, it is determined whether or not the traffic signaling device 30 is switched again to generate a stop signal. On the other hand, when the vehicle sensor 26 generates a vehicle sensing signal, the control unit 20 applies an enable signal to the camera 22 in response to the vehicle sensing signal applied thereto (Step S4). In response to the enable signal, the

camera 22 picks up the image of a front part of the sensed vehicle, and generates an image signal indicative of the picked-up image. The image signal from the camera 22 is sent to the memory unit 24 which, in turn, stores the image signal (Step S5). Accordingly, the user can identify the vehicle sensed as violating traffic regulations, based on the image signal stored in the memory unit 24.

As apparent from the above description, the present invention provides an automatic traffic monitoring method and apparatus for picking up images of vehicles passing through a crossroad while violating traffic regulations, thereby accurately detecting those vehicles.

Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.