Patent ID: 8368767

Claim:
A signal processing system comprising: an optical apparatus including a solid-state image pickup device configured to convert light incident thereon into an electrical signal and an optical element configured to allow light to be incident on the solid-state image pickup device; and a signal processing apparatus to which the optical apparatus is connected; wherein the solid-state image pickup device includes a pixel unit configured to convert light into an electrical signal, an A/D converter configured to convert a signal read from the pixel unit into a digital signal, a light modulation unit configured to modulate an externally input light beam using the signal digitized by the A/D converter and output a signal light beam based on the signal read from the pixel unit, and a timing generation unit configured to generate a synchronization signal used for synchronizing input and output of signals of the pixel unit, the A/D converter, and the light modulation unit, and a controller being configured to control readout of the signal, and wherein the signal processing apparatus includes a light emitting unit configured to output the light beam input to the light modulation unit of the solid-state image pickup device, a light receiving unit configured to receive the signal light output from the light modulation unit of the solid-state image pickup device, a readout control unit configured to control readout of the signal output from the pixel unit of the solid-state image pickup device, and a signal processing unit configured to process the signal read from the pixel unit and input from the solid-state image pickup device through optical communication, wherein, when the signal processing apparatus is turned on, power is supplied to the light receiving unit of the signal processing apparatus and, subsequently, power is supplied to the solid-state image pickup device, and wherein power is supplied to the light modulation unit of the solid-state image pickup device and, subsequently, is supplied to the pixel unit and, subsequently, is supplied to the light emitting unit of the signal processing apparatus, and wherein, when the signal processing apparatus is turned off, power supply to the light emitting unit of the signal processing apparatus is stopped and, subsequently, power supply to the pixel unit of the solid-state image pickup device is stopped and, subsequently, power supply to the light modulation unit is stopped, and wherein, after power supply to the solid-state image pickup device is stopped, power supply to the light receiving unit of the signal processing apparatus is stopped.