JPH07159533A - Approach detecting device - Google Patents

Abstract

PURPOSE:To provide an approach detecting device which, according to the time from transmission of intermittent ultrasonic codes to reception of an individual identification code at a responding sub-station, detects that the corresponding individual approaches and then outputs the individual identification code. CONSTITUTION:A sub-station 16 transmits a particular individual identification code when receiving an ultrasonic signal intermittently emitting a fixed code and coming from a main station 15. At the main station 15, the time difference from transmission of the code to the reception of the individual identification code, the individual identification code, and the order of generation of codes responded by the sub-station 16 are stored in memory 13. If someone approaches and goes into the range below the threshold of approach distance or approaches at a speed greater than the threshold of approaching speed, an individual identification code extractor 14 outputs the corresponding individual identification code.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proximity detection device for informing an approaching object.

[0002]

2. Description of the Related Art In recent years, a system in which a personal computer terminal and a host computer are connected online has been widely used. In this case, since many people use it, it is necessary to input the user ID and password of the user. The user walks to the place where the terminal is, sits down and inputs these from the keyboard.

If the terminal user who is approaching can be identified,
A user-specific code can be supplied to the terminal before the user sits down, and the software can be started up earlier.

Conventionally, in order to measure the distance from the camera to the subject, there is known a method of measuring the time until the reflected wave of the ultrasonic wave arrives, or the position where the light reflects and returns.

[0005]

However, in the above-mentioned conventional configuration, when the subject is a human, it is not possible to identify who is the subject and whether the subject is approaching or separating.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an approach detection device which determines who is approaching and outputs a personal identification code.

[0007]

In order to achieve this object, the proximity detection device of the present invention depends on the time difference from the time when an ultrasonic code is intermittently transmitted from a master station to the time when a personal identification code is received from a slave station. It is composed of a master station that extracts and outputs the personal identification code of a slave station that is approaching, and a slave station that emits a unique personal identification code when an intermittent ultrasonic code is received from the master station.

[0008]

With the above-described structure, the present invention outputs the corresponding personal identification code according to the time difference count value from the intermittent ultrasonic wave transmission from the master station to the reception of the personal identification code from the slave station. This makes it possible to extract the personal identification code that is approaching.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

The structure of this embodiment is shown in FIG. 1 is a pulse generator, 2 is a code generator, 3 is a modulator, 4 is an ultrasonic wave output stage, 5 is an ultrasonic wave input stage, 6 is a demodulator, 7 is a personal identification code generator, 8 is a modulator, and 9 is a modulator. Is an optical output stage, 10 is an optical input stage, 11 is a demodulator, 12 is a time difference calculator, 13 is a memory, 14 is an approaching personal identification code extractor, 15 is a main station,
16 is a slave station. Next, these operations will be described. Note that FIG. 2 is shown for the purpose of temporal explanation.

The main station 15 is placed in contact with, for example, a computer terminal, and the sub station 16 is attached to, for example, a name tag attached to the chest of people who may use the terminal. The pulse generator 1 intermittently generates pulses. This is shown in Fig. 2g. This pulse is code generator 2, time difference calculator 1
2. Drive the memory 13 and the personal identification code extractor 14 in the process of approaching. The code generator 2 generates a certain code each time the pulse from the pulse generator 1 is input. This is shown in FIG. This code may be any code as long as it can be determined that it came from the master station 15 when demodulated by the slave station 16. This code is modulated by the modulator 3, and an ultrasonic signal is transmitted from the ultrasonic output stage 4 to the air.

On the other hand, the slave station 16 receives the ultrasonic wave signal, amplifies it in the ultrasonic wave input stage 5, and then demodulates it in the demodulator 6. This is shown in Fig. 2b. If this demodulated output is a code unique to the master station 15, the personal identification code generator 7 generates a personal identification code unique to the slave station 16. This is shown in Figure 2c. If the code is not unique to the master station 15, the personal identification code generator 7 does not output it. The personal identification code is modulated by the modulator 8 and transmitted as an optical signal from the optical output stage 9.

In the main station 15, the optical input stage 10 receives and amplifies this optical signal. The demodulator 11 demodulates and outputs a personal identification code. This is shown in Figure 2d. Time difference calculator 1
2, each time a pulse from the pulse generator 1 is input, the time difference between the output of the code generator 2 and the output of the demodulator 11 (this corresponds to the pulse width shown in e of FIG. 2) is a certain clock. The time difference count value counted in is output. This is shown in Figure 2f. In the memory 13, the pulse generation order from the pulse generator 1, the personal identification code from the demodulator 11,
The time difference count value from the time difference calculator 12 is input. These memory modes are shown in FIG. In accordance with the pulse generation order, the personal identification code is stored in order from the slave station responding at the time of pulse generation with the smallest time difference count value. However, when there are a plurality of slave stations having the same distance from the master station 15, the signals from the slave stations are overlapped with each other and a proper personal identification code cannot be obtained. This time it will be rejected. The approaching personal identification code extractor 14 takes data from the memory 13 and extracts the personal identification code of the person who is most likely to approach.

FIG. 4 shows the relationship between the time difference count value and the pulse generation sequence in the first embodiment of the approaching personal identification code extractor 14. Here, it is indicated that there are responses from two types of slave stations, which are the X mark and the ● mark. Of these, when the X mark falls within the approach distance threshold, the personal identification code of the slave station indicated by the X mark is output. The flow of this extraction method is shown in FIG. First, the data of the first row is input from the memory 13. If the time difference count value is less than or equal to the approach distance threshold value, the corresponding personal identification code is output. When the time difference count value is larger than the approach distance threshold value, the data of the next line is input and the above determination is performed again.

FIG. 6 shows the relationship between the time difference count value and the pulse generation sequence in the second embodiment of the approaching personal identification code extractor 14. Here, it is indicated that there are responses from two types of slave stations, which are the X mark and the ● mark. Of these, the personal identification code of the slave station marked with X, which is larger than the approach speed threshold value, is output. The flow of this extraction method is shown in FIG. Data is input from the memory 13 line by line. Then, the latest two rows are extracted for each individual identification code, and the difference in the time difference count value of the two rows (corresponding to the difference in distance) with respect to the difference in the pulse generation order of the two rows (corresponding to the difference in pulse generation time) is calculated. The ratio, that is, the approach speed is calculated. If the approaching speed is greater than the approaching speed threshold value, the corresponding personal identification code is output. If the approaching speed is less than or equal to the approaching speed threshold value, the data for each line is further input and the above determination is performed again.

The approaching personal identification code extractor 14 is CP
It can be easily implemented by a microcomputer with U, memory and bus.

By supplying the output of the personal identification code extractor 14 on the way to the RS232C input terminal of the computer terminal, for example, personal software can be activated without directly inputting the personal identification code from the keyboard.

Although light is used as the communication medium from the slave station to the master station in the above embodiment, it goes without saying that it may be ultrasonic waves or electromagnetic waves.

As described above, according to this embodiment, the personal identification code of the slave station approaching the master station can be obtained.

[0020]

As described above, the proximity detecting device of the present invention is
Since it is possible to identify a user approaching from a remote place, by supplying the output of this proximity detection device to a computer terminal, software that requires a personal identification code can be activated before the user sits down. The time can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an approach detection device according to an embodiment of the present invention.

FIG. 2 is a timing diagram showing a temporal relationship of signals inside the proximity detection device in the embodiment.

FIG. 3 is an explanatory diagram showing a storage mode of a memory 13 in FIG.

4 is an approaching personal identification code extractor 14 in FIG.
Explanatory diagram showing the relationship between the time difference count value and the pulse generation order in the first embodiment of FIG.

FIG. 5 is a flowchart showing the operation of the extraction method in the first embodiment.

FIG. 6 is an approaching personal identification code extractor 14 in FIG.
Explanatory diagram showing the relationship between the time difference count value and the pulse generation order in the second embodiment of FIG.

FIG. 7 is a flowchart showing the operation of the extraction method in the second embodiment.

[Explanation of symbols]

 1 pulse generator 2 code generator 3 modulator 4 ultrasonic output stage 5 ultrasonic input stage 6 demodulator 7 personal identification code generator 8 modulator 9 optical output stage 10 optical input stage 11 demodulator 12 time difference calculator 13 memory 14 approaching personal identification code extractor 15 master station 16 slave station

Claims (3)

[Claims] 1. A main station that transmits an intermittent ultrasonic code, and a slave station that transmits a personal identification code when the ultrasonic code is received, wherein the main station is the An approach detection device that extracts and outputs the personal identification code of the approaching slave station depending on the time difference until the reception of the personal identification code. 2. The personal station, which corresponds to the case where the time difference count value from the time when the ultrasonic wave is intermittently transmitted from the master station to the time when the personal identification code is received from the slave station is equal to or less than a certain value. The approach detection apparatus according to claim 1, further comprising an approaching individual identification code extractor that outputs an identification code. 3. The main station is provided with a memory 2 for each personal identification code.
Extract the pulse generation order and the time difference count value for each row, and
2. An approaching personal identification code extractor which outputs the corresponding personal identification code when the ratio of the difference in the time difference count values for two rows to the difference in the pulse generation order for the rows is greater than a certain value. The approach detection device described.