Ion generator

Abstract

Provided is an ion generator that has a potential sensor provided integrally inside the main body of the ion generator, and that can measure, with the potential sensor, an electric field that reaches the potential sensor from a member from which static charge is to be eliminated, without being affected by an electric field between a discharge electrode and an opposing electrode. This ion generator comprises a discharge electrode, an opposing electrode, and a main body part including these electrodes, the ion generator sending out, toward a member from which static charge is to be eliminated, air ions generated by applying a high voltage between the electrodes. A potential sensor that measures the potential of the member from which static charge is to be eliminated is provided integrally to the main body part, and a projecting electrostatic-shielding plate that projects from the main body part is provided between the potential sensor and a discharge part constituted by the discharge electrode and the opposing electrode.

The invention claimed is: 
     
       1. An ion generator that blows air ions generated by applying a high voltage to a discharge unit including discharge electrodes and counter electrodes, toward a charged member, the ion generator comprising:
 a main body comprising:
 a potential sensor housing portion; 
 a potential sensor accommodated in the potential sensor housing portion and structured to measure potential of the charged member; 
 a detection window communicating with the potential sensor housing portion; and 
 a blow-off opening to blow-off the air ions; and 
 
 a projecting electrostatic shield plate disposed between the discharge unit and the potential sensor to project from the main body unit; 
 wherein the discharge unit is attached to the main body. 
 
     
     
       2. The ion generator according to  claim 1 , wherein a projection length of the projecting electrostatic shield plate is in a range of 8 to 10 mm. 
     
     
       3. The ion generator according to  claim 1 , wherein
 an aperture window communicating with the detection window is formed in the potential sensor to take in an electric field from the charged member. 
 
     
     
       4. The ion generator according to  claim 3 , wherein
 a plurality of the discharge electrodes is disposed at intervals along the blow-off opening, and 
 the projecting electrostatic shield plate intervenes between any of the discharge electrodes and the aperture window. 
 
     
     
       5. The ion generator according to  claim 4 , wherein the blow-off opening and the aperture window are disposed on same plane in the main body. 
     
     
       6. The ion generator according to  claim 3 , wherein a distance from the projecting electrostatic shield plate to the aperture window in the potential sensor is 2 mm or less. 
     
     
       7. The ion generator according to  claim 1 , wherein the blow-off opening and the potential sensor are disposed to be opposed to the charged member.