Image pickup apparatus for controlling the discharge of information charges in the image pickup apparatus

An image pickup apparatus for capturing an image of an object and supplying computer equipment with information of the image on a screen-by-screen basis, comprising:

• a solid state image pickup device having a plurality of pixels disposed in the form of a matrix with information charges corresponding to the object image produced and accumulated, a plurality of vertical shift registers disposed parallel to one another for temporarily storing a plurality of information charge packets read from the pixels respectively, a horizontal shift register for receiving sequentially the information charge packets from the respective vertical shift registers and outputting to transfer horizontally the plurality of information charge packets, and a drain for discharging the information charges accumulated in the pixels;
• a vertical timing control circuit for producing a vertical scanning timing signal at vertical scanning periods defined by a prescribed clock number of a reference clock with a fixed cycle;
• a horizontal timing control circuit for generating a horizontal scanning timing signal and a horizontal transfer flag which designates a transferring period of information charges for one line, in response to a transfer trigger which is output from said computer equipment;
• a drive circuit for transferring the information charge packets from the pixels to the vertical shift register according to the vertical scanning timing signal and, according to the horizontal scanning timing signal, transferring vertically the information charge packets from the vertical shift register to the horizontal shift register and driving the horizontal shift register to obtain an image signal;
• and
• an exposure control circuit for determining timing to discharge the information charges of said solid state image pickup device so that an exposure time, being a period between the discharge of the information charges from the pixels to the drain and the transfer of the information charges from the pixels to the vertical shift register, becomes of a period corresponding to a level of the image signal;
• wherein:
• said horizontal timing control circuit rises and clears said horizontal transfer flag corresponding to shift of a horizontal transferring timing of information charges for one line;
• and
• the drive circuit discharges the information charges at a timing defined by the exposure control circuit;
• and said exposure control circuit receives said horizontal transfer flag from said horizontal timing control circuit and delays the discharge timing from rising until the horizontal transfer flag is cleared and completes the discharge of said information charges within a blanking period, except for the transferring period, determined by the horizontal transfer flag during the vertical scanning period.

An image pickup apparatus for capturing an image of an object and supplying computer equipment with information of the image on a screen-by-screen basis, comprising:

• a solid state image pickup device on which a plurality of pixels are arranged in the form of a matrix, for accumulating information charges corresponding to the object image on the respective pixels;
• a vertical timing control circuit for determining repeatedly a vertical scanning period of said solid state image pickup device in a given period according to a reference clock with a given cycle;
• a horizontal timing control circuit for determining horizontal scanning timing of said solid state image pickup device, and generating a horizontal transfer flag which designates a transferring period of information charges for one line, in response to a transfer trigger supplied from said computer equipment synchronized with the reference clock;
• a drive circuit for discharging said information charges accumulated on the respective pixels of said solid state image pickup device and outputting an image signal to transfer sequentially on a line-by-line basis information charges newly stored after a lapse of a desired period upon being controlled by said vertical timing control circuit and said horizontal timing control circuit;
• and
• an exposure control circuit for determining a timing for discharging said information charges of said solid state image pickup device according to a level of said image signal;
• wherein:
• said horizontal timing control circuit rises and clears said horizontal transfer flag corresponding to shift of a horizontal transferring timing of information charges for one line;
• and
• said exposure control circuit receives said horizontal transfer flag from said horizontal timing control circuit and completes the discharge of said information charges of said solid state image pickup device within a blanking period, except for the transferring period, determined by the horizontal transfer flag during the vertical scanning period.

An image pickup apparatus for capturing an image of an object and supplying computer equipment with information of the image on a screen-by-screen basis, comprising:

• a solid state image pickup device having a plurality of pixels disposed in the form of a matrix with information charges corresponding to the object image produced and accumulated, a plurality of vertical shift registers disposed parallel to one another for temporarily storing a plurality of information charge packets read from the pixels respectively, a horizontal shift register for receiving sequentially the information charge packets from the respective vertical shift registers and outputting to transfer horizontally the plurality of information charge packets, and a drain for discharging the-information charges accumulated in the pixels;
• a vertical timing control circuit for producing a vertical scanning timing signal at vertical scanning periods defined by a prescribed clock number of a reference clock with a fixed cycle;
• a horizontal timing control circuit for generating a horizontal scanning timing signal and a horizontal transfer flag which designates a transferring period of information charges for one line, in response to a transfer trigger which is output from said computer equipment;
• a drive circuit for transferring the information charge packets from the pixels to the vertical shift register according to the vertical scanning timing signal and, according to the horizontal scanning timing signal, transferring vertically the information charge packets from the vertical shift register to the horizontal shift register and driving the horizontal shift register to obtain an image signal;
• and
• an exposure control circuit for determining timing to discharge the information charges of said solid state image pickup device so that an exposure time, being a period between the discharge of the information charges from the pixels to the drain and the transfer of the information charges from the pixels to the vertical shift register, becomes of a period corresponding to a level of the image signal;
• wherein:
• said horizontal timing control circuit rises and clears said horizontal transfer flag corresponding to shift of a horizontal transferring timing of information charges for one line;
• and
• the drive circuit discharges the information charges at a timing defined by the exposure control circuit;
• and said exposure control circuit receives said horizontal control flag from said horizontal timing control circuit and completes the discharge of said information charges within a blanking period, except for the transferring period, determined by the horizontal transfer flag during the vertical scanning period.