Aisin Seiki Kabushiki Kaisha

Masahiro Hagimoto

Takehiro Tabata

Hisashi Inaba

Eiji Mushiake

Rikuo Hatano

Takaaki Koizumi

Takashi Hara

Masaki Kato

Kazuki Mizutani

Kazunori Sugimura

An antenna drive apparatus applying an antenna drive voltage to an antenna from an H-bridge circuit including four switching elements to drive the antenna, includes: a switching mechanism to switch between a full-bridge state in which a differential voltage between a pulse voltage and a reverse pulse voltage reversed from the pulse voltage is applied to the antenna as the antenna drive voltage, and a half-bridge state in which the pulse voltage or the reverse pulse voltage is applied to the antenna as the antenna drive voltage; and a control mechanism to control the switching mechanism so that the frequency of the full-bridge state per unit time during an initial period of driving of the antenna in a transmission period for transmitting a transmission signal by the antenna becomes higher than that during the subsequent period in the transmission period.

Antenna drive apparatus

An antenna drive apparatus having a drive control unit and an antenna connected to the drive control unit via first and second connecting lines, and driven by an AC signal at a first resonant frequency, includes: a first driven member connected to the drive control unit via the connecting lines and driven by the AC signal at a second resonant frequency; a sensing member connected to the drive control unit via the connecting lines and driven by a DC signal, capable of sensing approach or contact of a person and, outputting a sensing signal indicating the fact that the approach or the contact has been sensed to the drive control unit via the first connecting line; and a stop mechanism configured to stop a function of the sensing member when the AC signal supplied to the antenna or the first driven member is sensed.

A door opening/closing apparatus includes an opening/closing handle provided in a vehicle door, electrodes disposed in the door handle, a detection circuit configured to detect a change of electrostatic capacitance which occurs in the vicinity of the electrodes when a human body portion approaches or contacts the door handle and then to output a locking or unlocking operation signal and a device for executing locking or unlocking of the door based on the operation signal, and a transmission/reception antenna for effecting transmission/reception with a portable unit corresponding to the vehicle, wherein the door handle includes an insulating base body, and on a vehicle outer side surface of the base body, there is attached a metal layer comprised of a group of island shaped metal particles that extend along the surface of the base body and that are separated from each other.

Door opening/closing apparatus and coating film forming method

Provided is a capacitance detection apparatus capable of effectively discriminating between an external factor due to e.g. water drops and a human-induced operation and allowing detection of occurrence of the human-induced operation with a simple arrangement. The apparatus alternately executes a first switching control process and a second switching control process, the first and second switching control processes executing a second switch operation with different charging periods from each other. In each of the first and second switching control processes, the number of repetition times of the second switch operation is counted until the potential of a terminal of a reference capacitance changes to a set potential. Based on the number of repetition times in at least one of the two switching control processes, presence/absence of change in determined capacitance (i.e. capacitance to be determined) is determined and based on the numbers of repetition times in the two control processes, it is determined whether the change in the determined capacitance is due to an event of detection interest or not.

Capacitance detection apparatus

A transmitter portionincludes a control circuit, a driver circuit, and a wave detector circuit. The control circuitgenerates control signals Vp, Vn based on a pulsed transmission signal So. The driver circuit, which is supplied with a battery voltage Vb, generates an output signal Sa to be sent to an antennabased on the control signals Vp, Vn. The wave detector circuitoutputs a detection signal Sk having a voltage proportional to the level of the output signal Sa (transmission power level). The control circuitchanges the pulse widths of the control signals Vp, Vn based on the voltage level of the detection signal Sk. As a result, electric power consumption is reduced and enlargement of an apparatus is suppressed while maintaining the transmission power level constant.

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Anjo, Japan

Masahiro Hagimoto