JPS61184479A - Proximity alarm apparatus - Google Patents

Abstract

PURPOSE:To make it possible to use high-pitched tone speakers in common without mutual interference, by separating a sound signal and an ultrasonic signal by a band-pass filter. CONSTITUTION:A first band-pass filter 8 is arranged between a tone burst generator 2 and a first high-pitched tone speaker 9 for transmission to prevent the envelope frequency component of the audible region of a tone burst signal from regenerating from the high-pitched tone speaker 9. Further, only the ultrasonic component reflected from matter is taken out from a second high-pitched tone speaker used as the high-pitched tone speaker of a television receiver in common by a second band-pass filter 11. By this method, two high-itched tone speakers for the stereoscope of the television receiver and the ultrasonic sensor of a proximity alarm can be used in common.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a proximity alarm device built into a television receiver.

2. Description of the Related Art Proximity alarm devices are generally used for automatic doors, rear visibility of automobiles, and the like. With the spread of television in recent years, the viewing time is becoming longer than that of listening to music. In particular, viewing for a long time near a television receiver is not preferable in terms of eye strain.The present invention relates to a proximity alarm built into a television receiver to prevent eye strain.

Generally, a proximity alarm device using ultrasonic waves includes a timing generation circuit 1 and a tone burst generator that generates a tone burst signal according to the period and width of the pulse generated by the timing generation circuit 1, as shown in FIG. 2, a first piezoelectric element 3 that converts the output into ultrasonic waves, and a second piezoelectric element 4 that detects the ultrasonic waves generated by the first piezoelectric element 30 that are reflected back to an object. , second piezoelectric element 4
an amplifier 5 for amplifying the detected voltage generated by the object to a sufficient amplitude; and a timing generation circuit 1 for measuring the distance to the object.
It consists of a comparator 6 that compares the pulse generated by the detector with the detected voltage amplified by the amplifier 5, and an alarm device 7 (for example, a buzzer) for inputting the recognition signal of the comparator 6 and notifying a person.

Next, the pulses generated by the timing generation circuit 1 will be described. The period of the tone burst is T1 as shown in FIG. 3(a), and the pulse width is T2. Therefore, as shown in FIG.
The desired tone burst signal can be obtained by gating the output of the original oscillator at the frequency of the ultrasonic wave with the pulse shown in ).

The comparator 6 checks whether there is an ultrasonic wave reflected during the "O" period of the pulse shown in FIG. 3(b) and sends a recognition signal to the alarm 7 if a reflected wave exists during that period.

It is possible to detect the presence or absence of an object and its distance in the manner described above.

Problems to be Solved by the Invention However, when trying to incorporate a proximity alarm device that uses ultrasonic waves into a television receiver, almost all parts of the proximity alarm device including the ultrasonic sensor are removed from the original television receiver. This will increase the number of parts and the price if they are added to the parts of the television receiver.

The present invention solves these conventional problems, and uses a simple configuration to measure the distance between the viewer of the television receiver and the television receiver, and to issue an alarm if the viewer is too close. The present invention provides a proximity alarm device that generates an alarm.

Means to solve the problem If you try to share the ultrasonic sensor of the proximity alarm with the high-frequency speaker of the television receiver, the envelope frequency component of the tone burst signal from the transmitting speaker that converts it into ultrasonic waves. I can hear it in the audible range. Furthermore, since the reception speaker is also used for high-pitched sounds in a television receiver, there is a drawback that the high-pitched sounds of the broadcast sound are input to the detector.

The proximity alarm device of the present invention includes a first bandpass filter for passing an ultrasonic component of a toneburst signal between a toneburst generator and a first high-frequency speaker for transmission, and a first bandpass filter for passing an ultrasonic component of a toneburst signal. A second band-pass filter is installed between the second high-frequency speaker and the amplifier that amplifies the detection signal.

Function: The proximity alarm device of the present invention has a first band-pass filter installed between the tone burst generator and the first high-frequency speaker for transmission, thereby reducing the audible envelope frequency of the tone burst signal. In addition to preventing the ultrasonic components from being reproduced from the high-frequency speakers, the system also extracts only the ultrasonic components reflected from objects from the second high-frequency speakers that are also used as the high-frequency speakers of the television receiver. This is accomplished by a second bandpass filter connected to a second treble speaker. As described above, the two high-pitched speakers for the stereo of the television receiver and the ultrasonic sensor for the proximity alarm are shared.

Embodiment Hereinafter, a proximity alarm according to an embodiment of the present invention will be explained with reference to the drawings. As shown in FIG. 1, the proximity alarm device of the present invention uses two high-frequency stereo speakers attached to a television receiver as an ultrasonic sensor, and a tone burst generator 2 and a tone burst generator 2. , a first bandpass filter 8 that passes only the ultrasonic frequency component of the toneburst wave generated by the toneburst generator 2.
, a first high-frequency speaker 9 that converts the ultrasonic frequency component that has passed through the first band-pass filter 8 into an ultrasonic wave, and a reflected sound of the ultrasonic wave emitted from the first high-frequency speaker reflecting off an object. Second treble speaker 1 that collects sound
0, a second bandpass filter 11 that passes only the ultrasonic components collected by the second high-frequency speaker, and a second
an amplifier 6 that sufficiently amplifies the detection signal that has passed through the bandpass filter; a timing generation circuit 1 that outputs a timing signal for determining the period and pulse of the tone burst signal; and a timing signal generated by the timing generation circuit 1 and the amplifier. Comparator 6 for comparing the detection signal amplified by 6
and an alarm device 7 which inputs the output of the comparator 6 and conveys the information to a human by, for example, sounding a buzzer or emitting a light. A first capacitor 1 connected to a first treble speaker 9 and a second treble speaker 10, respectively.
2 and the second capacitor 13 are cut-off capacitors that transmit only the treble part of the audio signal of the television receiver to the treble speaker, and the audio signal is added to the first input 14 and the second input 15. .

In this way, when the treble speaker is shared as an ultrasonic transmitter and a receiver, the audio signal and the ultrasonic signal will not be separated by the band pass filter, and the treble speaker can be shared without mutual interference. becomes possible.

Effects of the Invention As described above, the proximity sensor device of the present invention detects when a person is near the front of a television receiver,
It was designed to encourage people to move backwards,
In particular, by using a bandpass filter to separate the treble speaker into audio signals and ultrasonic signals,
By sharing the ultrasonic sensor with the treble speaker, the number of parts and costs can be reduced.

Please note that the alarm device must be one that makes a sound (e.g. a buzzer).
, a device that emits light (for example, a light emitting diode), etc., but it goes without saying that a cathode ray tube of a television receiver may be used to display an alarm signal thereon.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a proximity alarm device according to an embodiment of the present invention, FIG. 2 is a block diagram of a conventional proximity alarm device, and FIG. 3 is a timing diagram of tone burst generation. 1... Timing generation circuit, 2... Tone burst generator, 3, 4... Piezoelectric element, 5
...Amplifier, 6...Comparator, 7...
...Alarm, 8,11...Band pass filter, 9,10...Treble speaker, 12.1
3. Old... Capacitor, 14.15... Audio signal input terminal.

Claims (1)

[Claims] a tone burst generator; a first bandpass filter that passes an ultrasonic component of a toneburst signal generated by the toneburst generator; and an ultrasonic signal of the toneburst signal that has passed through the first bandpass filter. a first high-frequency speaker that converts the ultrasonic waves into ultrasonic waves; a second high-frequency speaker that collects the ultrasonic waves that hit an object and are reflected; and a second high-frequency speaker that passes the ultrasonic components from the signal collected by the second high-frequency speaker. a second bandpass filter, an amplifier for amplifying the ultrasound signal passed through the second bandpass filter to a sufficient amplitude, and a timing signal for setting the period and width of the toneburst signal to the toneburst generator; It consists of a timing generation circuit, a comparator that compares the timing signal of the timing generation circuit and the signal detected by the amplifier, and an alarm that inputs the recognition signal obtained by the comparator and conveys the information to a person. A proximity alarm device characterized in that a speaker, an ultrasonic transmitter, and an ultrasonic receiver are used in common.