Semiconductor integrated circuit device and imaging system
View Patent ↗An AD-converted digital video data is encoded by a difference encoding method before it is outputted and such encoded digital video data is then outputted, after it is converted to gray code or to a predetermined code in which a fixed value is added. Problems solved include noise that is generated when the AD conversion circuit outputs video data and that migrates into a CCD side via a power supply line on a printed circuit board, and noise that appears on a display image by migration into an input terminal side from an output circuit side via the power supply line and a semiconductor substrate within an AD conversion LSI.
1. A semiconductor integrated circuit comprising:
an amplifying circuit for amplifying an analog color video signal output from an imaging element;
an analog to digital conversion circuit for converting the analog color video signal output from the amplifying circuit to a digital signal comprising codes;
a differential circuit for obtaining a difference between codes of adjacent pixels in regards to same colors; and
a code conversion circuit for executing a conversion operation to output codes from the differential circuit;
wherein the codes are of adjacent pixels in regards to an order in which the analog, color video signal is outputted,
wherein change bits between a second output code from the code conversion circuit and a next to the second output code are less in number than change bits between a first output code and a next to the first output code by the conversion operation when the first output code changes from positive to negative,
wherein change bits between the second output code and the next to the second output code are less in number than change bits between the first output code and the next to the first output code by the conversion operation when the first output code changes from negative to positive.
2. A semiconductor integrated circuit according to claim 1 , wherein the conversion operation is a gray code conversion operation for converting an input binary code as the first output code to a gray code.
3. A semiconductor integrated circuit according to claim 1 , wherein the conversion operation is an operation for adding or subtracting a fixed value to or from the first output code.
4. A semiconductor integrated circuit according to claim 1 , wherein the codes depend on a color filter of the imaging element.
5. A semiconductor integrated circuit comprising:
an amplifying circuit for amplifying an analog color video signal output from an imaging element;
an analog to digital conversion circuit for converting the analog color video signal output from the amplifying circuit to a digital signal comprising codes;
a differential circuit for obtaining a difference between codes of adjacent pixels in regards to same colors; and
a code conversion circuit for executing a conversion operation to output codes from the differential circuit,
wherein the codes are of adjacent pixels in regard to an order in which the analog color video signal is outputted,
wherein change bits between a second output code from the code conversion circuit and a next to the second output code are less in number than change bits between a first output code and a next to the first output code by the conversion operation, if the first output code is inversed based on a complement representation when the difference is obtained by the differential circuit.