Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
2000-02-28
2001-07-03
Mullen, Thomas (Department: 2632)
Communications: electrical
Condition responsive indicating system
Specific condition
C250S221000
Reexamination Certificate
active
06255946
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an object detection apparatus, and more particularly, an object detection apparatus using an infrared signal. This application for the object detection apparatus is based on Korean patent application No. 1999-9593, which is incorporated by reference herein for all purposes.
2. Description of the Related Art
An object detection apparatus for detecting persons in a room typically employs passive sensors. The passive sensors detect thermal radiation from a person located in a certain detection angle range. The sensitivity of such an detection apparatus may be varied by an adjustment of the detection angle range of each passive sensor, which usually is set to be wide enough. The passive sensor, however, may operate erroneously according to the change of the room temperature and be influenced by an external interference. Accordingly, the object detection apparatus employing passive sensors can be used only in a room, but not out of a building. Further, the passive sensor cannot detect an object when the object is distant from the sensor, and thus is inadequate in an application where a precise detection is required.
In order to overcome such drawbacks, another conventional object detection apparatus uses an infrared beam to detect the presence of an object. The object detection apparatus comprises an infrared emitter constantly emitting the infrared beam and an infrared sensor disposed to face the infrared emitter and receiving the infrared beam from the emitter. When an object crosses a beam path between the infrared emitter and the infrared sensor, a blank period is introduced in the beam received by the infrared sensor. The apparatus detects the presence of the object by determining such a blank period. The apparatus, however, cannot determine the direction of the object, that is, whether the object enters or exits the room, when the object is detected.
As an approach for detecting the presence as well as the direction of the object passing through a gate, it can be contemplated to dispose a pair of the detection apparatuses in parallel and combine the detection data from the apparatuses. It is difficult to carry out arranging two detection apparatuses at a gate, however, because construction work has to be performed for four positions near the gate in addition to installing a separate module for combining detection data from the apparatuses.
On the other hand, the object detection apparatus is installed for each gate. In this regard, there has not been proposed a low cost system having a console for aggregating data from a plurality of object detection apparatuses, displaying synthetically the data or ringing a chime upon receiving a detection signal from one of the gates, and managing the apparatuses. Security providing companies operate a system for displaying data from multiple object detection apparatuses in a single display panel. Since being relatively expensive, however, it is inappropriate to install such a system in a small building having plural gates or independently in a single floor of a building.
SUMMARY OF THE INVENTION
To solve the problems above, one object of the present invention is to provide a sensor assembly which is simple and compact and capable of detecting the presence and direction of an object passing through a gate precisely.
Another object of the present invention is to provide a low cost system for detecting the presence and direction of an object passing through a gate, for example, a door of a building or a room, and announcing the detection result to the operator or persons in the building or the room.
A sensor assembly for achieving one of the above objects is suitable for use in a system for detecting an object passing through a gate and includes a reflector and an infrared transceiver. The infrared transceiver may be disposed to face the reflector. The infrared transceiver generates a first and a second infrared beams to emit to the reflector and receives a mixed beam in which the first and the second beams reflected by the reflector are superimposed. According to the present invention, the infrared transceiver comprises a first and second infrared emitters for generating the first and the second infrared beams, respectively. The first and the second infrared emitters are mounted in a single housing.
A system for achieving another one of the above objects detects an object passing through a gate supported laterally by a frame. The system comprises a reflector, signal generating and determining means, and a user interface. The reflector is disposed at an edge of the frame. The signal generating and determining means is disposed at the other edge of the frame so as to face the reflector. The signal generating and determining means generates a first and a second infrared beams to emit to the reflector, receives a mixed beam in which the first and the second beams reflected by the reflector are superimposed, and determines the presence and direction of the object passing through the gate based on the mixed beam. The user interface notifies a user the presence and direction of the object when the object passes through the gate and receives an operation command from the user.
The signal generating and determining means comprises a first and second infrared emitters for generating the first and the second infrared beams, respectively. The first and the second infrared emitters are mounted in a single housing.
The sensor assembly of the present invention is compact because it comprises a single reflector and a single infrared receiver, and can simply be installed near a gate. Also, according to the present invention, it is possible to detect the presence as well as the direction of an object passing through a gate by use of a single sensor assembly at the gate. Particularly, because a single user interface can be interfaced with plural reflectors and signal generation and detection units, the system according to the present invention facilitates the monitoring of objects passing gates, at a glance, in a building or a room having a plurality of gates.
REFERENCES:
patent: 3787693 (1974-01-01), Stone
patent: 4009389 (1977-02-01), Lindholm
patent: 4272762 (1981-06-01), Geller et al.
patent: 4277727 (1981-07-01), Levert
patent: 4410884 (1983-10-01), Heiland
patent: 4507654 (1985-03-01), Stolarczyk et al.
patent: 4516115 (1985-05-01), Frigon et al.
patent: 4719363 (1988-01-01), Gallacher
patent: 4736097 (1988-04-01), Philipp
patent: 4816667 (1989-03-01), Meinert
patent: 5353149 (1994-10-01), Urakami et al.
patent: 5656900 (1997-08-01), Michel et al.
Mullen Thomas
Shanks & Herbert
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