JPS61184480A - Proximity alarm apparatus - Google Patents

Abstract

PURPOSE:To emit an alarm when a person is present immediately in front of a television receiver, by arranging an ultrasonic sensor to the front surface of the television receiver. CONSTITUTION:A first piezoelectric element 3 for transmitting an ultrasonic wave and a second piezoelectric element 4 for receiving a reflected wave are arranged to the front surface of the cabinet of a television receiver. The torn burst signal driving the first piezoelectric element 3 is generated from a tone burst generator 2 and the detection signal detected by the second piezoelectric element 4 is amplified by an amplifier 5 so as to have sufficient amplitude to be applied to a comparator 6. The comparator 6 compares said detection signal with the period of the pulse '0' of a timing generation circuit 1 and, if there is detection voltage in this period, a confirmation signal is sent to an alarm 7. By this method, when a person is present in the vicinity of the front surface of a television, an alarm is issued to urge a person to step back.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is incorporated into a television receiver or the like. The present invention relates to a proximity alarm device.

2. Description of the Related Art Proximity alarm devices are generally used for automatic doors, rear confirmation of automobiles, and the like. These proximity alarm devices use an infrared sensor, an ultrasonic sensor, or the like as a detector. With the spread of television in recent years, viewing time is becoming longer than in the past. For this reason, eye fatigue may be a problem due to long hours of viewing. In particular, it is said that watching television closely increases eye strain. The present invention particularly relates to a proximity alarm device built into a television receiver to prevent eye strain.

The proximity alarm using ultrasonic waves is as shown in Figure 2.
A timing generation circuit 1, a tone burst generator 2 that generates a tone burst signal according to the cycle generated by the timing generation circuit 1, a first piezoelectric element that converts the output into an ultrasonic wave, and a first piezoelectric element 3. A second piezoelectric element 4 that detects the ultrasonic waves generated by the object and reflected back to the object.
and an amplifier 5 that amplifies the detection voltage generated by the second piezoelectric element to a sufficient amplitude, and compares the pulse generated by the timing generation circuit 10 to measure the distance to the object with the detection voltage amplified by the amplifier 5. and an alarm device 7 which inputs the output of the comparator 6 and transmits the information to a human by, for example, sounding a buzzer or emitting a light.

Next, the pulses generated by the timing generation circuit 10 will be described in detail. As shown in Figure 3 (→), the period of the tone burst is T1 and its pulse width is T2. Therefore, if the frequency of the ultrasonic wave is gated with the pulse shown in Figure 3 (11), the desired tone burst signal can be obtained. Figure 3 (
The pulse l is the pulse generated by the timing generation circuit 1. The detector 6 checks whether there is an ultrasonic wave reflected during the 0'' period of the pulse, and if a reflected wave is present during that period, it sends a recognition signal to the alarm 7.

As described above, it is possible to detect the presence or absence of an object and its distance.

Problems to be Solved by the Invention However, such a proximity alarm device has not yet been applied to a television receiver.

The present invention applies this proximity sensor to a television receiver to issue a warning to people watching the television receiver nearby, thereby preventing eye strain.

Means for Solving the Problems The proximity alarm device of the present invention has an ultrasonic sensor placed in front of a television receiver.

Function: The proximity alarm device of the present invention has an ultrasonic sensor placed in front of the television receiver, so that it can issue an alarm if a person is directly in front of the television receiver, prompting the person to move backwards. It encourages this.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. As shown in FIG. 1, a first piezoelectric element 3 for transmitting ultrasonic waves and a second piezoelectric element 4 for receiving reflected waves are arranged on the front surface of a cabinet 10 of a television receiver. The tone burst signal driving the first piezoelectric element 3 is generated by the tone burst generator 2 of FIG. The detection signal detected by the second piezoelectric element 4 is amplified to a sufficient amplitude by the amplifier 5 of FIG. 2, and is applied to the comparator. The comparator 6 compares it with the "0" period of the pulse generated by the timing generating circuit 1, and sends a recognition signal to the alarm 7 if there is a detected voltage during that period. Further, the pulse from the timing generating circuit 1 is applied to the tone burst generator 2 to control the period 9 width of the tone burst signal.

Effects of the Invention As described above, the present invention has an ultrasonic sensor for generating ultrasonic waves placed in front of the television receiver, so that if a person is near the front of the television, an alarm is issued and the person is instructed to move back. Enables you to encourage.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a television receiver showing an embodiment of the present invention, Fig. 2 is a block circuit diagram of a proximity alarm device using a piezoelectric sensor, and Fig. 3 is a timing diagram for generating a tone burst of a proximity alarm. It is a diagram. 1... Timing generation circuit, 2... Tone burst generator, 3, 4... Piezoelectric sensor, 6... Amplifier, 6...・Comparator, 7・
...Alarm.

Claims (1)

[Claims] A first piezoelectric element for transmitting ultrasonic waves placed on the front side of a television receiver, a second piezoelectric element for receiving reflected waves placed on the front side of the television receiver, and the first piezoelectric element. A tone burst generation circuit to drive, an amplifier to amplify the detection voltage of the second piezoelectric element, a timing generation circuit to control the period and width of the tone burst signal generated by the tone burst generation circuit, and a pulse generation circuit of the timing generation circuit. A proximity alarm device consisting of a comparator that compares detected voltages amplified by an amplifier, and an alarm that issues an alarm based on the recognition signal output from the comparator.