JPH06317675A - Presence detecting device - Google Patents

Abstract

PURPOSE:To provide a practical presence detecting means without malfunction being uninfluenced by electric noise. CONSTITUTION:An impedance converting part 11 is adjacently connected to the lead-out terminal part 6 of a body movement detecting means 1. Impedance conversion is performed in the body movement detecting means 1. Accordingly, even if electric noise is applied to a cable 9 for connecting the body movement detecting means 1 to a judging means 2, since a signal inputted to the judging means 2 is the signal after impedance conversion, noise components are not amplified. There is thereby no influence on presence judgment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupancy detection device for detecting the presence or absence of a human body in an occupancy.

[0002]

2. Description of the Related Art Conventionally, this type of presence detecting apparatus detects a body movement detecting means 1 for detecting a body movement characteristic based on a life activity of a human body, and whether or not a human body is present based on an output signal of the body movement detecting means 1. And the determination means 2 for determination. (For example,
FIG. 3 is an external perspective view of the device, and FIG. 4 is a block diagram of the device. Here, the body movement detecting means 1 is, for example, a polymeric piezoelectric material 3 such as polyvinylidene fluoride, electrodes 4 and 5 for deriving an output signal of the piezoelectric material 3, and a derivation terminal portion 6 for deriving an output signal of the electrodes 4,5. Consists of. The piezoelectric material 3 and the electrodes 4 and 5 are formed by laminating in a film shape and have flexibility. The lead-out terminal portion 6 includes the electrodes 5 and 6
The terminals 7 and 8 for outputting the output from the electrodes and the electrodes 5 and 6 are joined together and reinforced, and the joined portions are molded with resin. A cable 9 is connected to the terminals 7 and 8 and is connected to the terminal portion 10 of the determination means 2. The determination unit 2 includes an impedance conversion unit 11, a filter 12, an amplification unit 13, a smoothing unit 14, and a determination unit 15. The judging means 2 is built in the main unit 16. The body movement detecting means 1 is arranged, for example, under the seating surface of the seat or under the cover of the backrest.

With the above structure, the piezoelectric material 3 detects the body movement caused by the heartbeat activity and the respiratory activity of the human body, and the piezoelectric material 3 is detected.
Is a high impedance, it is converted into a low impedance by the impedance conversion unit 11, only the necessary frequency component is selected by the filter 12, amplified by the amplification unit 13, and the signal is smoothed by the smoothing unit 14. If the determination unit 15 has a signal of a certain level or higher based on the body movement caused by the heartbeat activity or respiratory activity of the human body, it is determined to be seated, and if the signal is less than that, it is determined to be absent.

[0004]

However, in the above configuration, when the cable 9 is subjected to electrical noise due to a commercial power source, electromagnetic waves, etc., the piezoelectric material 3 itself has a high impedance, so that even if the added noise level is very small. There is a problem that the level input to the determination unit 2 becomes high, and the presence of the human body is actually determined, but the presence of the human body causes a malfunction.

The present invention solves the above problems, and an object thereof is to provide a practical presence detecting means which is not affected by electrical noise and which does not malfunction.

[0006]

In order to solve the above-mentioned problems, an occupancy detection apparatus of the present invention is provided with a piezoelectric material, electrodes provided on both sides of the piezoelectric material, and the electrodes bonded to the electrodes. Body movement detection means having a lead-out terminal portion for leading out an output signal, an impedance converter connected adjacent to the lead-out terminal portion, and only a specific frequency component of the output signal of the impedance converter A filter that filters
An amplification unit that amplifies the output signal of the filter, a smoothing unit that smoothes the output signal of the amplification unit, and a determination unit that determines whether or not a human body is present based on the output signal of the smoothing unit. And a determination means having

Further, according to the present invention, the impedance conversion section is built in the lead-out terminal section.

[0008]

The present invention operates as follows with the above construction.

That is, since the impedance conversion section is connected adjacent to the lead-out terminal section of the body movement detecting means and the body movement detecting means performs the impedance conversion, the impedance connecting section is connected to the cable connecting the body movement detecting means and the judging means. Even if electrical noise is added, the signal input to the determination means does not affect the presence determination because it is a signal after impedance conversion.

Further, since the impedance conversion portion is built in the lead-out terminal portion, the lead-out terminal portion can serve not only to reinforce the joint between the terminal and the electrode but also to reinforce the impedance conversion portion.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an external perspective view of a seating detection apparatus according to an embodiment of the present invention. The difference of this embodiment from the above-mentioned conventional example is that the body movement detecting means 1 has an impedance conversion section 11 adjacent to the lead-out terminal section 6, and the determination means 2 does not have the impedance conversion section 11. is there. Since the configuration other than this is the same as that of the conventional example, the same reference numerals are given and detailed description thereof will be omitted.

With the above structure, the impedance conversion section 11 is connected to the lead-out terminal section 6 of the body movement detecting means 1 so as to be adjacent thereto, and the body movement detecting means 1 performs the impedance conversion. Judgment means 2 even if added
Since the signal input to is a signal after impedance conversion, there is an effect that the noise component is not amplified and the presence determination is not affected.

As another embodiment, as shown in FIG. 2, the impedance conversion portion 11 may be built in the lead-out terminal portion 6, which has the same effect as described above and the lead-out terminal portion 6 is provided with the terminal 7. , 8 and the electrodes 5, 6 are not only reinforced, but also the impedance conversion unit 11 is reinforced, so that the reliability is improved.

If the body movement detecting means 1 of the above-mentioned embodiment is covered with a flexible shield material and a shield cable is used as the cable 9, an occupancy detecting apparatus with less influence on electrical noise can be provided. It is also possible to provide.

[0015]

As described above, the presence detection device of the present invention has the following effects.

That is, since the impedance conversion section is connected adjacent to the lead-out terminal section of the body movement detecting means, and the body movement detecting means performs impedance conversion, the cable connecting the body movement detecting means and the judging means is connected. Even if electrical noise is added, the signal input to the determination means is a signal after impedance conversion, so the noise component is not amplified and does not affect the presence determination.

Further, since the impedance conversion portion is built in the lead-out terminal portion, not only reinforcement of the joining of the terminal and the electrode at the lead-out terminal portion but also reinforcement of the impedance conversion portion can be performed, so that the reliability is improved. .

[Brief description of drawings]

FIG. 1 is an external perspective view of an occupancy detection device according to an embodiment of the present invention.

FIG. 2 is an external perspective view of an occupancy detection device according to another embodiment of the present invention.

FIG. 3 is an external perspective view of a conventional presence detection device.

FIG. 4 is a block diagram of the device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body movement detection means 2 Judgment means 3 Piezoelectric material 4, 5 Electrode 6 Lead-out terminal part 9 Cable 11 Impedance conversion part 12 Filter 13 Amplification part 14 Smoothing part 15 Judgment part

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazunari Nishii 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masayoshi Miki, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Shunichi Nagamoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A piezoelectric material, an electrode provided on both surfaces of the piezoelectric material, a lead-out terminal portion for joining the electrode and leading out an output signal of the electrode, and an impedance converter connected adjacent to the lead-out terminal portion. A body movement detecting means having a section, a filter for filtering only a specific frequency component of the output signal of the impedance conversion section, and determining whether a human body is present based on the output signal of the filter An occupant detection apparatus comprising: a determination unit having a determination unit; and a connection unit that connects the body movement detection unit and the determination unit. 2. The seating detection apparatus according to claim 1, wherein the impedance conversion unit is built in the lead-out terminal unit.