An imaging device for measurement processing, the imaging device comprising: a housing; an imaging element for providing an image signal, the imaging element being fixed to the housing a lens for guiding incident light to the imaging element; and an adjustment mechanism for adjusting the distance between the lens and the imaging element by moving the lens along an optical axis of the lens, the optical axis extending in a first direction, the adjustment mechanism comprising: an adjustment screw comprising a first threaded portion having a longitudinal axis extending in a second direction that is different from the first direction; a lens slider including a second threaded portion engaging the first threaded portion such that rotation of the adjustment screw is converted into a movement of the lens slider in the second direction; a lens guide fixed to the housing and guiding the lens slider to be moveable in the second direction; a lens holder, the imaging lens being fixed to the lens holder, the lens holder being guided by the lens guide to be moveable in the first direction; and wherein the lens guide forms part of a conversion mechanism for converting the movement of the lens slider in the second direction into a movement of the lens holder in the first direction; characterized in that the adjustment screw being attached to the housing so as to be rotatable with respect to the housing around its longitudinal axis so that its movement in the second direction relative to the housing is restrained; and in that the lens slider has a frame structure constituted by two horizontal frame parts extending in a third direction different from the first and second directions, and two vertical frame parts extending in the second direction, the second threaded portion being arranged on an outer side of one of the vertical frame parts. a housing; an imaging element for providing an image signal, the imaging element being fixed to the housing a lens for guiding incident light to the imaging element; and an adjustment mechanism for adjusting the distance between the lens and the imaging element by moving the lens along an optical axis of the lens, the optical axis extending in a first direction, the adjustment mechanism comprising: an adjustment screw comprising a first threaded portion having a longitudinal axis extending in a second direction that is different from the first direction; a lens slider including a second threaded portion engaging the first threaded portion such that rotation of the adjustment screw is converted into a movement of the lens slider in the second direction; a lens guide fixed to the housing and guiding the lens slider to be moveable in the second direction; an adjustment screw comprising a first threaded portion having a longitudinal axis extending in a second direction that is different from the first direction; a lens slider including a second threaded portion engaging the first threaded portion such that rotation of the adjustment screw is converted into a movement of the lens slider in the second direction; a lens guide fixed to the housing and guiding the lens slider to be moveable in the second direction; a lens holder, the imaging lens being fixed to the lens holder, the lens holder being guided by the lens guide to be moveable in the first direction; and wherein the lens guide forms part of a conversion mechanism for converting the movement of the lens slider in the second direction into a movement of the lens holder in the first direction; the adjustment screw being attached to the housing so as to be rotatable with respect to the housing around its longitudinal axis so that its movement in the second direction relative to the housing is restrained; and in that the lens slider has a frame structure constituted by two horizontal frame parts extending in a third direction different from the first and second directions, and two vertical frame parts extending in the second direction, the second threaded portion being arranged on an outer side of one of the vertical frame parts.