Image pickup device, spatial information detecting apparatus using the same device and method for taking out received-light output from the same device

A spatial information detecting apparatus comprising:

• a light emission source configured to irradiate a light intensity-modulated by a modulation signal to a target space;
• an image pickup device for receiving light from said target space, generating electric charges corresponding to a received-light amount, and outputting the electric charges as a received-light output;
• and
• an analyzer configured to determine spatial information of the target space according to the received-light output of said image pickup device,
• wherein said image pickup device comprises a plurality of image pickup units formed on a semiconductor substrate, each of which comprising:
• a light receiving array of photoelectric conversion elements, each of which is configured to receive light, and generate electric charges corresponding to a received-light amount;
• a transfer array of charge transfer elements;
• an accumulation array of charge accumulation elements, which is configured to accumulate the electric charges transferred from said light receiving array through said transfer array;
• a plurality of control electrodes, which are formed at regions corresponding to said photoelectric conversion elements on said semiconductor substrate through an insulating layer, and used to transfer the electric charges from said light receiving array to said transfer array;
• and
• a charge-amount adjusting portion configured to determine an amount of undesired electric charges depending on an environmental light existing in the target space to be separated from the electric charges generated by each of said photoelectric conversion elements,
• said transfer array and said light receiving array being arranged in a line in a first direction,
• said accumulation array being disposed adjacent to said transfer array in a second direction substantially orthogonal to the first direction,
• said transfer array and said accumulation array being disposed in a light shielding region, and
• each of said charge accumulation elements having a charge storage capacity greater than a saturation charge amount of each of said photoelectric conversion elements, and
• said accumulation array and said charge-amount adjusting portion being arranged in a line in the first direction.