Abstract: The present invention aims to provide an electronic document viewing system meeting the convenience of users, while ensuring the security of electronic documents. A viewing apparatus has an acquiring unit for receiving a first layer and a second layer from a creating apparatus. The first layer contains a document laid out therein, and the second layer is defined to cover at least part of the first layer. The viewing apparatus also has a control unit for setting a display mode of the second layer, and a display unit for displaying the electronic document file in accordance with the display mode set by the control unit.

Abstract: A vibration/acceleration sensor is provided which includes a basic sensor unit fixed to a casing adapted to be mounted on a body the vibrations of which are to be detected. The sensor unit is surrounded by a resinous material having a low heat transfer coefficient. The sensor unit includes a vibration detecting unit including a piezoelectric bending vibrator, thin plates each formed of, for example, a resinous material having a low heat transfer coefficient, provided respectively on the upper and lower surfaces of the vibration detecting unit, and a signal processing circuit formed on the upper thin plate.

Abstract: A method of driving an ultrasonic motor having a rotation body (6) which is rotated by travelling waves generated in a vibrator body (3), whereby the drive frequency of the motor is controlled in accordance with the value of an operating parameter such as phase difference between drive current and voltage, such as to maintain the drive frequency at a value which is lower than the antiresonance frequency of the vibrator body (3) and higher than a highest resonance frequency of the vibrator body (3) in a hysteresis loop exhibited by a resonance frequency characteristic of the vibrator body (3). Continuous stable operation is attained, irrespective of the effects of temperature and load changes upon the motor operating characteristics.

Abstract: A fine adjustment apparatus for an optical system lens includes an annular laminated piezoelectric vibrator. The lens is attached to the inner peripheral portion of the piezoelectric vibrator. The piezoelectric vibrator is firmly supported at its outer peripheral portion by a proper member. The piezoelectric vibrator is deflected by the application of a voltage, whereby the lens is finely displaced in the optical axis direction thereof. The piezoelectric vibrator may be formed by laminating two annular piezoelectric elements with an annular metal plate sandwiched therebetween. Each of the piezoelectric elements has the axis of polarization extending in the thicknesswise direction thereof. The metal plate has a thickness which does not exceed at least 25% of the total thickness of the two piezoelectric elements.

Abstract: A rotary magnetic head apparatus having a bending mode vibrator or vibrators mounted on a rotary cylinder, the vibrator comprising either ring shape piezoelectric vibrators bonded together with their polarization axes aligned in the direction of the thickness or the bonded piezoelectric vibrators bisected along a diameter of the ring, the bending vibrator mounting thereon a magnetic head or heads.