A photoelectric conversion device comprising: a plurality of light receiving elements that are arrayed in one direction and each convert a light signal into an electrical signal V_sig; a plurality of A/D conversion units that perform A/D conversion on the electrical signals V_sig output from the light receiving elements; and an offset giving unit configured to give an offset voltage Vpga to the electrical signals V_sig output from the light receiving elements before the electrical signals V_sig are input into the A/D conversion units, characterized in that: the A/D conversion units are arrayed in the one direction along the light receiving elements, and applied with a reference voltage Vrefn through first wiring extending in the one direction from a reference voltage source disposed on one end side of the array, and the offset giving unit further comprises: a plurality of offset generators that each generates the offset voltage Vpga which is shifted by an amount α in voltage with respect to the reference voltage Vrefn applied to the A/D conversion units and to the plurality of generators through the first wiring, wherein the amount α is a value which prevents the image signal from being below the reference voltage Vrefn, and a plurality of amplifiers that each receives through its respective non-inverting input terminal, the offset voltage Vpga generated by the respective offset generator, receives through its respective inverting input terminal, the electrical signal V_sig output from the light receiving elements, and outputs the electrical signal to the respective A/D conversion unit. a plurality of light receiving elements that are arrayed in one direction and each convert a light signal into an electrical signal V_sig; a plurality of A/D conversion units that perform A/D conversion on the electrical signals V_sig output from the light receiving elements; and an offset giving unit configured to give an offset voltage Vpga to the electrical signals V_sig output from the light receiving elements before the electrical signals V_sig are input into the A/D conversion units, characterized in that: the A/D conversion units are arrayed in the one direction along the light receiving elements, and applied with a reference voltage Vrefn through first wiring extending in the one direction from a reference voltage source disposed on one end side of the array, and the offset giving unit further comprises: a plurality of offset generators that each generates the offset voltage Vpga which is shifted by an amount α in voltage with respect to the reference voltage Vrefn applied to the A/D conversion units and to the plurality of generators through the first wiring, wherein the amount α is a value which prevents the image signal from being below the reference voltage Vrefn, and a plurality of amplifiers that each receives through its respective non-inverting input terminal, the offset voltage Vpga generated by the respective offset generator, receives through its respective inverting input terminal, the electrical signal V_sig output from the light receiving elements, and outputs the electrical signal to the respective A/D conversion unit. the A/D conversion units are arrayed in the one direction along the light receiving elements, and applied with a reference voltage Vrefn through first wiring extending in the one direction from a reference voltage source disposed on one end side of the array, and the offset giving unit further comprises: a plurality of offset generators that each generates the offset voltage Vpga which is shifted by an amount α in voltage with respect to the reference voltage Vrefn applied to the A/D conversion units and to the plurality of generators through the first wiring, wherein the amount α is a value which prevents the image signal from being below the reference voltage Vrefn, and a plurality of amplifiers that each receives through its respective non-inverting input terminal, the offset voltage Vpga generated by the respective offset generator, receives through its respective inverting input terminal, the electrical signal V_sig output from the light receiving elements, and outputs the electrical signal to the respective A/D conversion unit. a plurality of offset generators that each generates the offset voltage Vpga which is shifted by an amount α in voltage with respect to the reference voltage Vrefn applied to the A/D conversion units and to the plurality of generators through the first wiring, wherein the amount α is a value which prevents the image signal from being below the reference voltage Vrefn, and a plurality of amplifiers that each receives through its respective non-inverting input terminal, the offset voltage Vpga generated by the respective offset generator, receives through its respective inverting input terminal, the electrical signal V_sig output from the light receiving elements, and outputs the electrical signal to the respective A/D conversion unit. receives through its respective non-inverting input terminal, the offset voltage Vpga generated by the respective offset generator, receives through its respective inverting input terminal, the electrical signal V_sig output from the light receiving elements, and outputs the electrical signal to the respective A/D conversion unit.