A reading apparatus for reading a target object includes a photosensor module having a plurality of photosensors arranged at least one plane, and a transparent conductive layer provided between the target object and the photosensor module.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Continuation-in-Part application of U.S. patent application Ser. No. 09/263,167, filed Mar. 5, 1999, now U.S. Pat. No. 6,414,297, the entire contents of which are incorporated herein by reference.
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 10-078575, filed Mar. 12, 1998, the entire contents of which are incorporated herein by reference.
A capacitance detecting circuit of a capacitive sensor having a plurality of column lines and a row line intersecting the column lines detects a change in capacitance at an intersection of a column line and a row line. The circuit includes a PN code generating unit for generating a code having orthogonality in time sequence to output the generated code as a column drive signal, a column line drive unit for driving a predetermined one of the column lines which are selected in response to the code, a capacitance detecting unit, connected to the row line, for detecting a voltage by converting a total sum of changes in capacitance at intersections of the selected column lines into the voltage to output the detected voltage, and a decode processing unit for performing a predetermined calculation on the detected voltage output from the capacitance detecting unit and the code to determine a voltage value responsive to the capacitance change at the intersection.
An image reading apparatus for reading an image pattern of a detecting object comprises a detecting surface on which a detecting object is placed, a sensor array having a plurality of sensors arranged to read an image pattern of the detecting object placed on the detecting surface, a first detection electrode, provided on at least an upper portion of the sensor array, having the detecting surface; a second detection electrode provided to be electrically insulated and spaced from the first detection electrode; a counter electrode provided to be opposite to the first detection electrode through an interlayer insulating film; signal voltage applying circuit which applies a signal voltage having a first signal waveform that varies periodically to the counter electrode to excite a second signal waveform to the first detection electrode through the interlayer insulating film, and contact detector which determines whether the detecting object brought into contact with the detecting surface is a specific detecting object based on a third signal waveform excited to the second detection electrode according to contact of the detecting object with both the first detection electrode and the second electrode wherein a reading operation of the image pattern of the detecting object is performed based on the determination result by the contact detector.
