IMAGE FORMATION DEVICE

PURPOSE:To reduce the quantity of variation due to thermal influence and to prevent a focus function from deteriorating by fitting a 1st screw mount to a lens mount and fitting a CCD block, a CCD, a CCD pressure plate, an insulator, and a 2nd screw mount with the screw mount. CONSTITUTION:The lens mount 3 is fitted to a chassis 5 and the screw mount 4 is fitted to the lens mount 3; and a screw mount 10 is fitted to the left end of the 1st screw mount 4 as a fulcrum and the CCD block 1 and CCD 2 are fitted to the 2nd screw mount 10 through the insulator 7 and CCD pressure plate 6. Therefore, constituent parts 3 and 4 shift in a minus direction from the optical axis about the chassis 5 under thermal influence, but the CCD block 1, CCD 2, CCD pressure plate 6, insulator 7, and screw mount 10 shift in a pulse direction along the optical axis and the quantity of variation becomes equal or minimum by subtraction. Consequently, defocusing is minimized.