Endoscope system

Abstract

An endoscope 2 has a CCD 9 incorporated in the distal part of an insertion unit 6 thereof. The sensitivity of the CCD 9 can be varied by applying a plurality of pulsating driving signals so as to change an electron multiplication rate. The endoscope 2 is connected to a processor 3 so that it can be disconnected freely. Information representing a type of endoscope stored in advance in a ROM 48 is transmitted to a controller 21 incorporated in the processor 3. The control means 21 uses a CCD sensitivity control means 12 to control the sensitivity of the CCD 9 according to the type of connected endoscope 2. Consequently, a view image of proper brightness can be produced irrespective of the type of endoscope 2.

1 - 19 . (canceled)  
     
     
         20 . An endoscope system comprising 
 an endoscope having a solid-state imaging device comprising a charge multiplication mechanism for varying a sensitivity by varying a charge multiplication rate in accordance with the number of pulses or amplitude of the pulses provided to the solid-state imaging device;    a signal processing unit for processing an output signal from the solid-state imaging device;    a light source unit for selectively irradiating first light to perform ordinary light observation and second light to perform special light observation to an object;    an observation mode switching device for switching between the ordinary light observation by the first light and the special light observation by the second light; and    a light amount adjustment unit for adjusting an amount of light irradiated from the light source unit to the object based on the output signal from the solid-state imaging device,    wherein the light amount adjustment unit adjusts the amount of light irradiated from the light source unit to the object based on the output signal from the solid-state imaging device, while keeping constant the charge multiplication rate of the charge multiplication mechanism by varying the number of pulses or the amplitude of the pulses provided to the solid-state imaging device.    
     
     
         21 . An endoscope system according to  claim 20 , further comprising an irradiating light switching device for switching the light irradiated to the object between the first light and the second light in accordance with an output from the observation mode switching device.  
     
     
         22 . An endoscope system according to  claim 21 , wherein the charge multiplication mechanism is provided at a preceding stage of a detection amplifier.  
     
     
         23 . An endoscope system according to  claim 21 , wherein the solid-state imaging device detects an object image by the first light and an object image by the second light.  
     
     
         24 . An endoscope system according to  claim 23 , wherein the effective period during which charges are accumulated in the solid-state imaging device when the first light is irradiated to the object is different from that when the second light is irradiated to the object.  
     
     
         25 . An endoscope system according to  claim 21 , wherein the solid-state imaging device comprises a first solid-state imaging device for detecting the object image by the second light and a second solid-state imaging device for detecting the object image by the first light.  
     
     
         26 . An endoscope system according to  claim 21 , wherein the second light is of wavelength falling within a wavelength band of excitation light to perform observation under fluorescent light.  
     
     
         27 . An endoscope system according to  claim 26 , wherein the effective period during which charges are accumulated in the solid-state imaging device when the second light is irradiated to the object is longer than that when the first light is irradiated to the object.  
     
     
         28 . An endoscope system according to  claim 21 , further comprising a sensitivity control unit for controlling the number of pulses or the amplitude of the pulses provided to the solid-state imaging device in accordance with whether the first or second light is irradiated to the object so that the charge multiplication rate of the charge multiplication mechanism remains constant.  
     
     
         29 . An endoscope system according to  claim 21 , further comprising an input unit for setting the charge multiplication rate of the charge multiplication mechanism.  
     
     
         30 . An endoscope system according to  claim 21 , wherein 
 the light source unit includes a lamp and a filter unit provided in the optical path between the object and the lamp and comprises a first filter to transmit light from the lamp so as to irradiate the first light to the object and a second filter to transmit light from the lamp so as to irradiate the second light to the object, and    the irradiating light switching device comprises a filter switching device for switching the filter unit provided in the optical path between the first filter and the second filter.    
     
     
         31 . An endoscope system according to  claim 30 , wherein 
 the filter unit is provided with a rotary filter rotated by a motor, and    the time that the second light is irradiated to the object via the second filter is longer than the time that the first light is irradiated to the object via the first filter.    
     
     
         32 . An endoscope system according to  claim 31 , further comprising; 
 an iris diaphragm which adjusts light level of the light irradiated to the object; and    an iris diaphragm controller,    wherein the iris diaphragm controller controls the iris diaphragm such that the iris diaphragm is opened when the light irradiated to the object is switched by the filter switching device from the first light to the second light.    
     
     
         33 . An endoscope system according to  claim 31 , wherein the first filter is provided along the periphery of the rotary filter, and the second filter is provided along the periphery of the rotary filter substantially in parallel to the first filter.  
     
     
         34 . An endoscope system comprising: 
 an endoscope having a solid-state imaging device comprising a charge multiplication mechanism for varying a sensitivity by varying a charge multiplication rate in accordance with the number of pulses or amplitude of the pulses provided to the solid-state imaging device;    a signal processing unit for processing an output signal from the solid-state imaging device;    a light source unit for selectively irradiating first light to perform ordinary light observation and second light to perform special light observation to an object;    an observation mode switching device for switching between the ordinary light observation by the first light and the special light observation by the second light;    a sensitivity control device for controlling the charge multiplication rate by varying the number of pulses or the amplitude of the pulses provided to the solid-state imaging device;    an automatic-gain control circuit for amplifying the output signal from the solid state imaging device when the level of the output signal is less than a predetermined level;    an iris diaphragm for adjusting a level of the first or second light irradiated to the object; and    an iris diaphragm controller;    wherein the iris diaphragm controller controls the iris diaphragm based on an output signal from the solid-state imaging device.    
     
     
         35 . An endoscope system comprising: 
 an endoscope having a solid-state imaging device comprising a charge multiplication mechanism for varying a sensitivity by varying a charge multiplication rate in accordance with the number of pulses or amplitude of the pulses provided to the solid-state imaging device;    a signal processing unit for processing an output signal from the solid-state imaging device;    a light source unit for selectively irradiating first light to perform ordinary light observation and second light to perform special light observation to an object;    an observation mode switching device for switching between the ordinary light observation by the first light and the special light observation by the second light;    a sensitivity control device for controlling the charge multiplication rate by varying the number of pulses or the amplitude of the pulses provided to the solid-state imaging device to vary the multiplication rate, the sensitivity control device controlling the number of sensitivity control pulses or amplitude of the sensitivity control pulses so that a level of an output signal from the solid-state imaging device may be a predetermined level;    an automatic-gain control circuit for amplifying the output signal from the solid state imaging device when the level of the output signal is less than a predetermined level;    an iris diaphragm for adjusting a level of the first or second light irradiated to the object; and    an iris diaphragm controller;    wherein the iris diaphragm controller controls the iris diaphragm based on an output signal from the solid-state imaging device.