Image device and method for driving optical system

A method for driving an optical system in an imaging device for picking up an image of an object via the optical system and recording image information in a recording medium, a driving system for the optical system being controlled according to a position of an operating unit, the method comprising the steps of:

• detecting a relatively-low-resolution absolute position of the operating unit;
• detecting a relatively-high-resolution relative position of the operating unit;
• generating a position output corresponding to a position in a restricted range of movement of the operating unit using a combination of the absolute position detected in the step of detecting the absolute position and the relative position detected in the step of detecting the relative position;
• initializing a value in a storage region storing the generated position output based on the absolute position detected in the step of detecting the absolute position;
• increasing or decreasing the value in the storage region based on a signal from the relative position detecting means after the initialization;
• setting the value in the storage region as the operating unit position as outputted from the absolute detecting means value if it is determined that the value in the storage region is not defined;
• controlling a motor via a driver to drive an object to be controlled by the driving system according to the generated position output of the operating unit;
• and
• driving the object to be controlled by the driving system using the motor.

An imaging device for picking up an image of an object via an optical system and recording image information in a recording medium, a driving system for the optical system being controlled according to a position of an operating unit, the imaging device comprising:

• a motor driving an object to be controlled by the driving system;
• a driver driving the motor;
• an absolute position detecting unit detecting a relatively-low-resolution absolute position of the operating unit;
• a relative position detecting unit detecting a relatively-high-resolution relative position of the operating unit;
• a position generating unit generating a position output corresponding to a position in a restricted range of movement of the operating unit using a combination of the absolute position detected by the absolute position detecting unit and the relative position detected by the relative position detecting unit;
• wherein the position generating means first initializes a value in a storage region storing the generated position output based on the absolute position detected by the absolute position detecting means;
• wherein the position generating means, after the initialization, increases or decreases the value in the storage region based on a signal from the relative position detecting means;
• wherein, if it is determined that the value in the storage region is not defined, the value in the storage region is set as the operating unit position as outputted from the absolute detecting means;
• and
• a control unit controlling the motor via the driver to drive the object to be controlled according to the generated position output of the operating unit.