Abstract: A double-layer type super-twisted nematic liquid crystal display system including a liquid crystal display device for displaying characters and/or graphic forms, a compensating liquid crystal device for compensating the optical phase of the liquid crystal display device, a temperature sensor for detecting the ambient temperature of those devices, a light sensor for calculation of the display contrast of the liquid crystal display device, drive voltage control circuits for controlling the drive voltages applied to the liquid crystal display device and the compensating liquid crystal device, and a displaying light source. In the display system, the drive voltages applied to the liquid crystal display device and compensating liquid crystal device are adjusted according to the calculation of contrast, whereby the display is high in contrast at all times independently of the ambient temperature.

Abstract: A developing apparatus for xerography including a developing roll, a regulator member for controlling developer thickness located proximate to the developing roll, and an elastic plate member arranged to elastically apply pressure to uniformly spread the developer on the developing roll.

Abstract: A device having a probe of the oxygen concentration cell type to be disposed in a combustion gas to detect actual air/fuel ratio values of an air-fuel mixture subjected to combustion. The probe has a gas impermeable layer of a solid electrolyte such as zirconia, a porous reference electrode layer made of a catalytic material such as platinum and formed on the solid electrolyte layer, a porous gas-diffusion layer covering the reference electrode layer and a porous and noncatalytic measurement electrode layer formed on the solid electrolyte layer so as to be spaced from the reference electrode layer. A DC power supply is connected to the probe to force a constant current of an adequate intensity to flow through the solid electrolyte layer between the two electrode layers. Depending on the direction of the current flow, an output voltage of this device becomes indicative of air/fuel ratio values above or below the stoichiometric air/fuel ratio.

Abstract: An air-fuel ratio detecting apparatus, comprises a first pair of electrodes, interposing a porous solid electrolyte therebetween, a second pair of electrodes, interposing a porous solid electrolyte therebetween, a dense solid electrolyte to which one of the first pair of electrodes and one of the second pair of electrodes contact, and a device for causing constant-currents to flow through the first and second pairs of electrodes, respectively, so as to detect voltage developed between the electrodes contacting with the dense solid electrolyte, thereby for obtaining air-fuel ratio detecting apparatus having uniform voltage output characteristics even by mass production.