Solid image pickup apparatus

Abstract

A solid image pickup apparatus which is not easily susceptible to an influence of an emitted light caused by impact ionization. The solid image pickup apparatus of the present invention includes an output circuit for converting a signal charge outputted from a photoelectric converter into an analog signal and outputting the signal. The output circuit includes a charge-voltage converter for converting the charge transferred from the photoelectric converter into a voltage signal, a plurality of source follower circuits for performing impedance conversion, and a reverse amplification circuit. A gate length of a MOSFET constituting the final-stage source follower circuit in the output circuit is longer than the gate length of the MOSFET of another source follower circuit or the like. Therefore, impact ionization does not occur in a position in which the impact ionization most easily occurs, the emitted light caused by the impact ionization does not enter the photoelectric converter, and an image quality can be prevented from being deteriorated.

1 - 5 . (canceled)  
     
     
         6 . A solid image pickup apparatus comprising: 
 a photoelectric converter; and    an output circuit, configured by connecting in series a plurality of stages of circuit blocks of at least one of a source follower circuit and an inverter, configured to output an electric signal in accordance with a signal charge photoelectrically converted by said photoelectric converter,    wherein at least one MOSFET among two MOSFET constituting the circuit block at a final stage is selectively formed of a lightly doped drain (LDD) structure.    
     
     
         7 . The solid image pickup apparatus according to  claim 6  wherein only the MOSFET constituting a current source among two MOSFETs constituting said circuit block at the final stage in said output circuit is formed into the lightly doped drain (LDD) structure.  
     
     
         8 . The solid image pickup apparatus according to  claim 6 , further comprising a transfer section configured to successively transfer the signal charge photoelectrically converted by said photoelectric converter in a predetermined direction, 
 wherein said output circuit outputs the electric signal in accordance with the signal charge transferred from said transfer section.    
     
     
         9 . The solid image pickup apparatus according to  claim 6 , further comprising: 
 a plurality of voltage conversion circuits configured to convert the charge accumulated in said photoelectric converter into a voltage signal for each pixel;    a plurality of MOS transistors which are disposed for said plurality of voltage conversion circuits, respectively, and which can supply the voltage signal converted by said corresponding voltage conversion circuit to said output circuit; and    a shift register configured to control an on/off state of said plurality of MOS transistors.    
     
     
         10 - 16 . (canceled)