| 摘要 |
PURPOSE:To elevate the sensitivity while reducing the noise by alternately inserting plates varied in the thickness into an insulated support according to the width of a pluraity of grooves which are formed alternately in a large and small width ro receive the end of the plates. CONSTITUTION:Broad grooves 11b' and 11b and narrow grooves 11a' and 11a are formed alternately in plurality each facing a pair of insulated supports 11 mounted inside a cover 5 and a case 4, and a thick plate 9 and a thin plate 10 are inserted alternately into the support according to the width of the grooves. For example, when the plate 9 is made as a high voltage plate and the plate 10 as signal plate, a thinner signal plate 9 can increases the effective opening width per 1 cell thereby elevating the sensitivity. The high voltage plate 10 made thicken enables the cancelling of changes in the static capacitance due to the vibration of the thin plate 9 in the right and left spaces. Thus, microphonic noise can be checked. |
