Method for detecting origin point of position sensor

A method for detecting a point of origin of a position sensor in a system for determining a position of an object member which is displaceable within a displacement range, said system including a stop means in proximity to an end of said displacement range, said position sensor being operable to generate an output indicative of the position of said object member, said method comprising the steps of:

• displacing said object member into an abutting relationship with said stop means;
• detecting a point of origin of said position sensor based on the position of said object member when abutting said stop means;
• and
• setting the point of origin of said position sensor detected by the detecting step, wherein during the step of detecting, said position sensor detects the position of said object member by means of a plurality of repetitive periodic waveforms,
• wherein said repetitive periodic waveforms are composed of sine waves and cosine waves.

A method for detecting a point of origin of a linear position sensor in a system for determining a position of an object member which is displaceable within a displacement range, said system including a stop means in proximity to an end of said displacement range, said linear position sensor being operable to generate an output indicative of the position of said object member, said method comprising the steps of:

• displacing said object member into an abutting relationship with said stop means;
• detecting a point of origin of said linear position sensor based on the position of said object member when abutting said stop means;
• and
• setting the point of origin of said linear position sensor detected by the detecting step, wherein said object member is displaced by a drive means for an optical element of a video camera, and said linear position sensor is used in connection with said drive means.

A method for detecting a point of origin of a position sensor in a system for determining a position of an object member which is displaceable within a displacement range, a stop-means in proximity to an end of said displacement range, said position sensor being operable to detect the position of said object member by means of repetitive periodic waveforms resolvable into multiple phases, said method comprising the steps of:

• displacing said object member in a first direction into an abutting relationship with said stop means;
• detecting the point of origin of said position sensor in accordance with a change of position of said position sensor when said object member abuts said stop means;
• determining a first phase of the repetitive periodic waveforms by comparing magnitudes of said periodic waveforms to each other;
• storing said first phase of the repetitive periodic waveforms, as reference data in a storage medium, said first phase corresponding to said position sensor being positioned at the detected point of origin;
• determining a second phase of said repetitive periodic waveforms by comparing magnitudes of said periodic waveforms, said second phase corresponding to a subsequent detection of the point of origin of said position sensor;
• comparing the stored reference data with said second phase of the repetitive periodic waveforms;
• and
• correcting the data of the point of origin determined by said subsequent detection according to said comparison.

A method for detecting a point of origin of a position sensor in a system for determining a position of an object member which is displaceable within a displacement range, an end point sensor disposed in proximity to an end of said displacement range, said position sensor being operable to generate an output indicative of the position of said object member, said method comprising the steps of:

• displacing said object member in a first direction until it reaches the end of said displacement range;
• detecting an arrival of the object member at the end of said displacement range by said end point sensor and thereupon generating a signal;
• storing object member position data from said position sensor as point of origin reference data in a storage medium in response to said signal from said end point sensor;
• comparing, in response to each subsequent signal from said end point sensor indicative of a subsequent arrival of said object member at the end of said displacement range, object member position data from said position sensor with the reference data;
• and
• correcting the point of origin of said position sensor according to said comparing step.