JPH02107550U

JPH02107550U -

Info

Publication number: JPH02107550U
Application number: JP1674689U
Authority: JP
Priority date: 1989-02-14
Filing date: 1989-02-14
Publication date: 1990-08-27

Description

[Brief explanation of drawings]

第１図は本考案の一実施例を自動車に適用した
場合における平面図、第２図は第１図に示す実施
例の回路構成を示すブロツク図、第３図は該実施
例の作動を示すタイミングチヤート、第４図はス
レツシヨルドレベルの変動を説明するタイミング
チヤートである。２，４，６，８…送波部、１３，１４…受波部
、９，１０，１１，１２…窓ガラス、２０，２１
，２２，２３…判定回路、２４…警報回路。 Fig. 1 is a plan view of an embodiment of the present invention applied to an automobile, Fig. 2 is a block diagram showing the circuit configuration of the embodiment shown in Fig. 1, and Fig. 3 shows the operation of the embodiment. Timing Chart FIG. 4 is a timing chart illustrating fluctuations in the threshold level. 2, 4, 6, 8... Wave transmitting section, 13, 14... Wave receiving section, 9, 10, 11, 12... Window glass, 20, 21
, 22, 23...determination circuit, 24...alarm circuit.

Claims

[Scope of Claim for Utility Model Registration] 1. A transmitter that is installed at a predetermined location inside the vehicle and transmits ultrasonic waves toward one of the multiple window panes arranged on the vehicle body, and It is characterized by being provided with a wave receiving unit that is attached to a location and receives the ultrasonic waves reflected by the first window glass, and an alarm circuit that is activated when the wave receiving unit detects a change in the state of the ultrasonic waves. anti-theft device for vehicles. 2. The wave transmitting section is attached to correspond to each of the plurality of window glasses and transmits ultrasonic waves at predetermined intervals, and the wave receiving section transmits the ultrasonic waves received from each of the window glasses. 2. The vehicle anti-theft device according to claim 1, further comprising a determination circuit for separately determining the vehicle. 3. The vehicle anti-theft device according to claim 1 or claim 2, wherein the determination circuit has a threshold level that varies depending on a signal input level of the ultrasonic wave to the wave receiving section. 4. Claim 2 or 4, wherein the wave receiving unit is divided into a part that receives ultrasonic waves from window glasses arranged on the right side of the vehicle body and a part that receives ultrasound waves from window glasses arranged on the left side of the vehicle body. The vehicle anti-theft device according to claim 3.