Position detecting apparatus and library apparatus

A library apparatus comprising:

• a medium storage cabinet storing a medium;
• a recording-playing unit performing a recording-playing process on said medium;
• a carrying mechanism carrying said medium between said medium storage cabinet and said recording-playing unit;
• and
• a position detecting apparatus for detecting a relative position of a measuring member to a measured member, comprising:
• a flag provided in said measured member, the flag including a first area having first optical characteristics and a second area having second optical characteristics different from the first optical characteristics;
• a sensor detecting optically said first area and said second area of said flag and further detecting a relative position, wherein said first area is formed as a pair of triangles or trapezoids that are positioned symmetrically with respect to an axis of the flag, and said sensor is adapted to detect said flag linearly, and wherein said position detecting apparatus is adapted to detect said relative position of said measuring member to said measured member based on a coordinate of a boundary position between said first area and said second area in a linear track detected by said sensor,
• wherein said flag is provided either in said medium storage cabinet or said recording-playing unit, and said sensor is provided in said carrying mechanism.

A library apparatus comprising:

• a plurality of medium storage parts in which a medium is stored, inserted and ejected;
• a carrying mechanism carrying said medium among said medium storage parts;
• a mark part providing a mark at a fixed position of said medium storage parts for detecting alignment of said medium storage parts;
• a sensor provided in said carrying mechanism and detecting said mark by scanning linearly;
• and
• a control part detecting an amount of misalignment from a normal position of said mark,
• wherein said mark detected by said sensor is defined by two boundaries, said boundaries being positioned symmetrically with respect to an axis of the mark part in a direction orthogonal with respect to a scanning direction of said sensor so that distances regarding said two boundaries vary continuously so as to detect said distances at a position different from an orthogonal direction with said scanning direction of said sensor, and wherein said control part detects said amount of misalignment from said normal position of said mark based on said distances regarding said two boundaries.

A library apparatus comprising:

• a plurality of medium storage parts in which a medium is stored, inserted and ejected;
• a carrying mechanism carrying said medium among said medium storage parts;
• a mark part providing a mark at a fixed position of said medium storage parts for detecting alignment of said medium storage parts;
• a sensor provided in said carrying mechanism and detecting said mark by scanning linearly;
• and
• a control part detecting an amount of misalignment from a normal position of said mark and controlling a carrying position of said carrying mechanism,
• wherein said mark detected by said sensor is defined by two boundaries, said boundaries being positioned symmetrically with respect to an axis of the mark part in a direction orthogonal with respect to a scanning direction of said sensor so that distances regarding said two boundaries vary continuously so as to detect said distances at a position different from an orthogonal direction with said scanning direction of said sensor, and wherein said control part detects said amount of misalignment from said normal position of said mark and controls said carrying position of said carrying mechanism based on said distances regarding said two boundaries.