System for detecting an object passing through a gate

• US 6,255,946 B1
• Filed: 02/28/2000
• Issued: 07/03/2001
• Est. Priority Date: 03/22/1999
• Status: Expired due to Term

• Current Assignee: Jae Han Kim
• Original Assignee: Jae Han Kim
• Inventors: Kim, Jae Han
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US09/514,305
• Time in Patent Office: 491 Days
• Field of Search: 340/556, 340/557, 340/555, 250/221
• US Class Current: 340/556
• CPC Class Codes: G08B 13/184 using radiation reflectors

Abstract

A 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. The system 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 of 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 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.

Claims

1. A system for detecting an object passing through a gate supported laterally by a frame, said system comprising:

a reflector disposed at an edge of the frame;

signal generating and determining means, disposed at the other edge of the frame so as to face said reflector, for generating a first and a second infrared beams to emit to said reflector, receiving a mixed beam in which the first and the second beams reflected by said reflector are superimposed, and determining the presence and direction of the object passing through the gate based on the mixed beam; and

a user interface for notifying a user of the presence and direction of the object when the object passes through the gate and receiving an operation command from the user,

wherein said signal generating and determining means comprises a first and second infrared emitters for generating the first and the second infrared beams, respectively,

wherein said first and said second infrared emitters are mounted in a single housing.

2. The system of claim 1, wherein said signal generating and determining means generates a first and a second pulse trains having a same period to each other to modulate the first and the second infrared beams according to the first and the second pulse trains, respectively, generating a received pulse train according to the mixed beam, and determining the presence and direction of the object using the received pulse train,

wherein the first and the second pulse trains are out of phase by a half of the period.

3. The system of claim 2, wherein said signal generating and determining means further comprises:

a first determination and control unit;

a first and a second pulse generators for generating the first and the second pulse trains to provide to the first and the second infrared emitters, respectively; and

an infrared receiver for receiving the mixed beam to generate the received pulse train;

wherein said first determination and control unit determines the presence and direction of the object using the received pulse train and outputs a data frame including a detection data representing the presence and direction of the object to said user interface.

4. The system of claim 3, wherein said signal generating and determining means further comprises:

a memory for storing a program code for operating said first determination and control unit.

5. The system of claim 3, wherein said user interface comprises:

a second determination and control unit for generating a sound control signal and a counting control signal;

means for generating sound in response to the sound control signal; and

a display for displaying a predetermined count in response to the counting control signal.

6. The system of claim 5, wherein said signal generating and determining means further comprises a modulator for modulating the data frame to output a modulated data frame through a predetermined channel,

wherein said user interface further comprises a demodulator for receiving the modulated data frame through the predetermined channel and demodulating the modulated data frame to provide a demodulated data frame to said second determination and control unit.

7. The system of claim 6, wherein the data frame includes an identification number of said signal generating and determining means.

8. The system of claim 6, wherein the predetermined channel is a wireless channel.

9. The system of claim 1, wherein each of the first and the second infrared beams has a constant waveform,

wherein wavelengths the first and the second infrared beams are different from each other.

10. The system of claim 1, wherein a plurality of said reflectors and said signal generating and determining means are provided so as to monitor objects passing through the plurality of gates, each of the plurality of said reflectors and said signal generating and determining means being installed at respective one of the plurality of gates,

wherein the plurality of said signal generating and determining means are connected to said user interface.

11. The system of claim 1, said signal generating and determining means further comprises:

means for determining an alignment state of said signal generating and determining means with respect to said reflector.

12. A sensor assembly for use in a system for detecting an object passing through a gate, said sensor assembly comprising:

a reflector; and

an infrared transceiver, being disposed to face said reflector, for generating a first and a second infrared beams to emit to said reflector and receiving a mixed beam in which the first and the second beams reflected by said reflector are superimposed,

wherein said infrared transceiver comprises a first and second infrared emitters for generating the first and the second infrared beams, respectively,

wherein said first and said second infrared emitters are mounted in a single housing.