Kanji Murano

A Small-Size Ultrasonic Linear Motor

A new structure for an ultrasonic linear motor using piezoelectric actuators has been developed. The ultrasonic vibrator consists of a metal bar with two legs. The direction of the sliders movement is controlled by changing the polarity of the drive voltage of the multilayered piezoelectric actuator. Typical performance characteristics of the linear motor are a velocity of 1 m/s and a static thrust of 100 gf.

Dielectric Properties of PbO–ZrO2–REOx Ceramics at Microwave Frequencies

The dielectric properties at microwave frequencies of PbO–ZrO2–REOx caramics prepared by hot-press sintering were investigated. The PbZrO3 ceramics modified by rare-earth oxides especially CeO2, Gd2O3 and Tb4O7 showed a high dielectric constant, a high Q value and a negative temperature coefficient of the resonant frequencies. To combine this with a conventional ceramic having a positive τf, we made a dielectric resonator which exhibited er=170, Q=1200 and τf=80 ppm/°C at 3 GHz. Furthermore, the application of this resonator enabled the development of a miniturized high characteristic band-pass filter.

A Video Projector Using a PLZT Light Shutter Array

A new light-valve video projector using a PLZT light shutter linear array has been developed. A beam from a Xenon light source passes through the PLZT linear array and the resulting modulated beam is scanned vertically by a movable mirror and projected on the screen. PLZT shutters in the array are modulated with analog signals sampled from the video signal. Each shutter maintains its light intensity for the horizontal scanning period of 63.5 microseconds. The floating driving method can be used to maintain the driving voltage at the specified level because the PLZT light shutters have a memory effect similar to a capacitor. The PLZT shutters are separated from each other to eliminate crosstalk caused by stray capacity. The shutter array is made using the cutting method, which is described in detail.

SrTiO3 Base BL Capacitors Prepared by Vapor Phase Diffusion

When a PbO–Bi2O3–Cu2O system vapor phase diffusion was applied to an SrTiO3–base semiconductive ceramic, a BL capacitor with a high apparent permittivity of 28500, a low dissipation factor of 0.3%, and a high resistivity of 2.6×1011 Ω cm was obtained.

Dielectric Characteristics of Modified SrTiO3 Ceramics and Their Application to a High-Voltage Capacitor

Dielectric characteristics of the ceramics in the (100-x) (Sr0.50Pb0.25Ca0.25)TiO3x(Bi2O33TiO2) system were investigated for x=0~8.25. The maximum dielectric constant at Curie temperature increased markedly under a DC biasing field. 100% increase, for example, was observed at -22°C under a 3 kV/mm DC biasing field for x=1.56. The increase of the dielectric constant under a high DC biasing field was also found in ceramic capacitors for high-voltage use which were fabricated with the use of the present material with x=4.3.

A Color Viewfinder Using PLZT Light Shutters and a B/W CRT

A new line-sequential color viewfinder has been developed, which is expected to facilitate greatly the viewing and operating of portable color video cameras. Tri-color separation PLZT light shutters are used to convert the black and white image of a 1.5 inch CRT to a color image providing a resolution of 250 TV lines/inch. The shutters, which have a low-power consumption, are switched at high speed by the line-sequential video signals. A high-brightness and fast-decay luminescence phosphor suitable for this application was investigated.

A PLZT Light Shutter with Low Power Consumption

To reduce the power consumption of a PLZT light shutter and the driving voltage change of it with the environmental temperature, we investigated the relation between halfwave voltage and temperature in various PLZT compositions. Compositions which showed a memory effect at room temperature showed large transverse quadratic electro-optic coefficients at temperatures higher than room temperature. We found these compositions required less power when the PLZT was kept at the higher temperature. A shutter consisting ofa PLZT with the composition 7.3/65/35 and an ITO heater showed low power consumption and a stable driving voltage when the PLZT was held at 100°C by the heater.