Image sensor and method for driving an image sensor for reducing fixed pattern noise

Abstract

There is provided a method of driving an image sensor which can remove FPN resulting from inter-chip variations without requiring any dark correction. A semiconductor photosensor chip has a plurality of sensor modules mounted on a mounting substrate, and a semiconductor device in which at least an N signal input buffer circuit for receiving N signals, an S signal input buffer circuit for receiving S signals, a differential circuit for calculating any difference between the outputs from the N and S signal input buffer circuits, and a voltage clamping circuit for clamping the output from the differential circuit are formed on a single semiconductor substrate, and the voltage clamping circuit clamps the reset state of S and N signal common output line.

1 - 32 . (canceled)  
   
   
       33 . An image sensor comprising: 
 a plurality of photo sensor chips mounted on a single mounting substrate, each photo sensor chip having a plurality of photo-electric conversion circuits, a common output line through which signals from said plurality of photo-electric conversion circuits are outputted, and a photo sensor chip output device which outputs signals from said common output line to outside of said photo sensor chip, wherein each said photo-electric conversion circuit has a photo-electric conversion part and an amplifier for amplifying an output signal from the photo-electric conversion part; and    a correction circuit output chip mounted on said single mounting substrate, said correction circuit output chip having a noise compensation circuit which receives a noise signal outputted from the amplifier and including an offset component of the amplifier, the noise signal being obtained by resetting an input portion of the amplifier and a photo-electric conversion signal generated in said photo-electric conversion part, wherein said noise compensation circuit corrects a noise component of the photo-electric conversion signal by using the noise signal outputted from the amplifier,    wherein said correction circuit output chip is arranged commonly to said plurality of photo sensor chips, and    wherein an output terminal for outputting a signal to outside of said correction circuit output chip and an output terminal for outputting a signal to outside of said single mounting substrate are connected to each other.    
   
   
       34 . The image sensor according to  claim 33 , wherein said noise compensation circuit has a differential circuit which calculates a difference between a first signal and a second signal and a clamp circuit connected to an output of said differential circuit.  
   
   
       35 . The image sensor according to  claim 34 , wherein said differential circuit calculates a difference between the noise signal and the photo-electric conversion signal read out from said photo sensor chip output device and said clamp circuit clamps a reset state of said common output line in said photo sensor chip.  
   
   
       36 . The image sensor according to  claim 33 , wherein said noise compensation circuit has a clamp circuit which clamps a reset state of said common output line in said photo sensor chip.  
   
   
       37 . The semiconductor device according to  claim 33 , wherein a power supply voltage of said correction circuit output chip is higher than a power supply voltage of said photo sensor chips.  
   
   
       38 . The semiconductor device according to  claim 33 , wherein GND wiring for said correction circuit output chip and GND wiring for said photo sensor chips are isolated from each other on said single mounting substrate.  
   
   
       39 . The semiconductor device according to  claim 37 , wherein GND wiring for said correction circuit output chip and GND wiring for said photo sensor chips are isolated from each other on said single mounting substrate.  
   
   
       40 . A method of driving an image sensor, said image sensor including: 
 (a) a plurality of photo sensor chips mounted on a single mounting substrate, each photo sensor chip having a plurality of photo-electric conversion circuits, a common output line through which signals from said plurality of photo-electric conversion circuits are outputted, and a photo sensor chip output device which outputs signals from said common output line to outside of said photo sensor chip, wherein each said photo-electric conversion circuit has a photo-electric conversion part and an amplifier for amplifying an output signal from the photo-electric conversion part; and    (b) a correction circuit output chip mounted on said single mounting substrate, said correction circuit output chip having a noise compensation circuit which receives a noise signal outputted from the amplifier and including an offset component of the amplifier, the noise signal being obtained by resetting an input portion of the amplifier and a photo-electric conversion signal generated in said photo-electric conversion part, wherein said noise compensation circuit corrects a noise component of the photo-electric conversion signal by using the noise signal outputted from the amplifier,    wherein said correction circuit output chip is arranged commonly to said plurality of photo sensor chips, and    wherein an output terminal for outputting a signal to outside of said correction circuit output chip and an output terminal for outputting a signal to outside of said single mounting substrate are connected to each other,    said method comprising the step of:    driving said compensation circuit to compensate for a noise component included in a photo-electric conversion signal read out from said photo sensor chip output device by using a noise signal read out from said photo sensor chip output device.