Abstract: An MEMS sensor of the present invention includes a substrate, a lower thin film provided on a surface of the substrate, an upper thin film opposed to the lower thin film at an interval on the side opposite to the substrate, and a wall portion surrounding the lower thin film and the upper thin film and protruding on the side opposite to the lower thin film with respect to the upper thin film.

Abstract: The acceleration sensor according to the present invention includes a circuit chip having a prescribed circuit built into a front surface thereof; a sensor chip bonded to the front surface of the circuit chip; and a resin package for sealing the circuit chip and the sensor chip, while the sensor chip includes: a membrane arranged to oppose to the front surface of the circuit chip and having a plurality of openings; a piezoresistor formed on a surface of the membrane opposed to the circuit chip; a support section provided on a side opposite to the circuit chip with respect to the membrane and supporting a peripheral edge portion of the membrane; and a weight section provided on the side opposite to the circuit chip with respect to the membrane and integrally held on a central portion of the membrane.

Abstract: Disclosed is a method of electrophotographic image formation according to which images of high quality can be reproduced with always stable density. This method which includes the step of image formation which comprises forming a static latent image on a photoreceptor by carrying out charging and exposing and then developing is characterized in that maximum image density is maintained constant by measuring surface potential of maximum image density portion just before development and setting developing bias potential based on the above measured surface potential so that difference between the surface potential and developing bias potential becomes constant.

Abstract: In practicing multi-step reproduction of color image by electrophotography using an electrophotographic photosensitive material prepared by overlaying a photosensitive layer composed mainly of titanium dioxide and a binder on an electroconductive substrate, exposure to an optical image is first carried out, then positive corona charging is carried out to form a positive electrostatic latent image and subsequently developing is carried out. Further, prior to the exposure to an optical image, negative corona charging and/or AC corona charging are additionally carried out. By this electrophotographic process effectively utilizing the photomemory effect of titanium dioxide, multi-color images can be produced, and an image having good contrast can be reproduced easily and stably.