Patent ID: 8885316
Filing Date: 2014-11-11
Classification: H01T

Abstract:
1. An ionizer comprising: at least one needle-shaped electrode arranged such that a distal end side thereof projects from within an ionizer main body; and a plate-shaped ground electrode arranged at a base end side of the needle-shaped electrode within the ionizer main body and distanced from a static charge eliminating space and the needle-shaped electrode, such that the ground electrode lies substantially perpendicular to the needle-shaped electrode, wherein an absolute value of a negative voltage applied to the needle-shaped electrode is set to be smaller than an absolute value of a positive voltage applied to the needle-shaped electrode, and a time period for which the negative voltage is applied to the needle-shaped electrode is set to be longer than a time period for which the positive voltage is applied to the needle-shaped electrode, wherein generation of positive ions at the distal end side of the needle-shaped electrode within the static charge eliminating space by application of the positive voltage to the needle-shaped electrode is carried out alternately with generation of negative ions at the distal end side of the needle-shaped electrode within the static charge eliminating space by application of the negative voltage to the needle-shaped electrode, wherein the ionizer further comprises: ion balance detecting means for detecting an ion balance of the positive ions and the negative ions in the static charge eliminating space, control means for controlling at least one of the positive voltage and the negative voltage; and warning means, wherein the ion balance detecting means includes a potential detecting means arranged inside the static charge eliminating space, for detecting a potential corresponding to an amount of the positive ions and an amount of the negative ions in the static charge eliminating space, wherein assuming that a sum of a time period during which the positive voltage is applied one time to the needle-shaped electrode and a time period during which the negative voltage is applied one time to the needle-shaped electrode equals one period, the control means calculates a time average of the potential corresponding to the ion balance of the positive ions and the negative ions over at least the one period, and increases only the absolute value of the negative voltage in a state in which the absolute value of the positive voltage is maintained constant corresponding to a difference between the amount of the positive ions and the amount of the negative ions in the case that the calculation result indicates that the amount of the positive ions is greater than the amount of the negative ions in the static charge eliminating space, and wherein, when the absolute value of the negative voltage is increased, the control means outputs a determination result to the warning means if it is determined that the absolute value of the negative voltage after being increased exceeds a predetermined threshold, and wherein the warning means provides a visual indication of the determination result, to an outside of the ionizer.