Image detection system

Abstract

In an image detection system having within one-chip IC an area sensor, an area sensor driver for driving the area sensor and an area sensor output processing circuit for processing an output of the area sensor, the charges accumulated in necessary pixel areas of the area sensor are transferred at a transfer clock of a speed at which A/D conversion may be performed by an A/D converter incorporated in a microcomputer and are read out in image blur detection, and the charges accumulated in unnecessary pixel areas are transferred at a high-speed transfer clock and dumped.

What is claimed is:  
     
         1 . An image detection system comprising: 
 a number n of area sensors;    a driving circuit for driving the area sensors;    an output circuit for outputting signals from the area sensors in synchronism with a transfer clock having a predetermined frequency and supplied to each of the area sensors;    a signal processing circuit for processing the signals outputted from the output circuit; and    a control circuit for performing switching at a frequency n times the frequency of the transfer clock in order to select a signal to be outputted from among those signals from the area sensors which are outputted in synchronism with the transfer clock.    
     
     
         2 . An image detection system as claimed in  claim 1 , 
 wherein the control circuit includes switching devices provided in output paths of the signals from the area sensors.    
     
     
         3 . An image detection system as claimed in  claim 1 , 
 wherein the area sensors, the driving circuit, and the signal processing circuit are formed in a single chip.    
     
     
         4 . An image detection system as claimed in  claim 1 , 
 wherein the signal processing circuit includes a variable-gain amplifier, a sample-and-hold circuit, and a clamping circuit.    
     
     
         5 . An image detection system as claimed in  claim 4 , 
 wherein the signal processing circuit samples and holds the signals from the area sensors with different timing from the timing with which the signals are switched.    
     
     
         6 . An image detection system as claimed in  claim 5 , 
 wherein whether an output of one area sensor is obtained or outputs of more than one area sensor are obtained is switched by changing the timing with which sampling is performed.    
     
     
         7 . An image detection system as claimed in  claim 1 , 
 wherein focus detection and image blur detection are performed based on an output of the signal processing circuit.    
     
     
         8 . An image detection system as claimed in  claim 7 , 
 wherein outputs of two area sensors are used for focus detection, and an output of one area sensor is used f or image blur detection.    
     
     
         9 . An image detection system as claimed in  claim 7 , 
 wherein the signal processing circuit includes a sample-and-hold circuit and switches between focus detection and image blur detection by changing the timing with which sampling is performed.    
     
     
         10 . A method for processing output signals from a number n of area sensors, comprising: 
 a transferring step for outputting signals from the area sensors in synchronism with a transfer clock having a predetermined frequency and supplied to each of the area sensors; and    an output control step for performing switching at a frequency n times the frequency of the transfer clock in order to select a signal to be outputted from among those signals from the area sensors which are outputted in synchronism with the transfer clock.    
     
     
         11 . An optical apparatus comprising: 
 a number n of area sensors;    a driving circuit for driving the area sensors;    an output circuit for outputting signals from the area sensors in synchronism with a transfer clock having a predetermined frequency and supplied to each of the area sensors;    a signal processing circuit for processing the signals outputted from the output circuit; and    a control circuit for performing switching at a frequency n times the frequency of the transfer clock in order to select a signal to be outputted from among those signals from the area sensors which are outputted in synchronism with the transfer clock.