Abstract: In a cold cathode electron beam device, groups of electron emission cones emit electrons which are extracted from the cones by respective extraction electrodes. The emitted electrons are focussed into a beam by an electron lens so as to strike a fluorescent screen. In order to minimize the size of the beam spot where the beam strikes the screen, a structure is included which compensates for a spherical aberration property which is inherent to the electron lens. The spherical aberration is compensated for by placing a focus electrode for each group of electron emission cones on a common substrate along with the extraction electrode, such that the focus electrode surrounds the extraction electrode.

Abstract: A drive circuit for a strain sensor includes a Wheatstone bridge having semiconductor strain gauges. A temperature-dependent voltage generator generates a voltage having a predetermined ambient temperature dependency characteristic, a constant voltage generator generates a predetermined constant voltage, and a proportional voltage generator generates a voltage proportional to an externally supplied power source voltage. A voltage processor receives and arithmetically processes output voltages of the temperature-dependent voltage generator, the constant voltage generator and the proportional voltage generator to generate a bridge drive voltage which changes from a mid value to a predetermined voltage depending on a temperature proportional to the power source voltage. In an amplifier circuit for amplifying a strain output signal from the Wheatstone bridge, both the potentials across an AC coupling capacitor are kept to be equal at a steady-state operation.

Abstract: Provided is a novel semiconductor accelerometer possessing an acceleration sensing feature including gage resistors on beams and a detecting feature for abnormality of the acceleration sensing feature in which the novel structure is manifested. The detection of abnormality of the acceleration sensing feature is accomplished by comparing a voltage applied to a bridge circuit comprising the gage resistors with a predetermined reference voltage. The detecting feature essentially comprises a comparator and a generator. The comparator compares the voltage applied to the bridge circuit with a predetermined reference voltage supplied from the voltage generator. When the gage resistors has abnormality in the sensing performance, the applied voltage takes a higher voltage than that in the normal state. Therefore, the comparison of the above both voltages permits recognizing the gage resistors to have abnormality.