Optical card reproducing apparatus for reproducing information with a two-dimensional solid-state imaging device

An optical card reproducing method comprising the steps of:

• irradiating a light beam on an optical card having a plurality of tracks for recording information as a sequence of pits on a recording surface and of focusing the light beam on said recording surface of said optical card, said tracks being divided by track guides;
• forming an image of a recording surface of said optical card on a two-dimensional solid-state image sensing means including a plurality of photoelectric conversion elements distributed on a plane;
• obtaining an image signal from said plurality of photoelectric conversion elements by specifying a row address, that is, an address in a row-direction, and a column address, that is, an address in a column-direction;
• converting the image signal obtained from said plurality of photoelectric conversion elements into a binary value;
• detecting either said row address or said column address corresponding to the image of said track guide formed on said two-dimensional solid-state image sensing means, based on the binary valued signal obtained in said converting step;
• calculating either said row address or said column address corresponding to the image of said sequence of pits, based on said row address or said column address corresponding to the image of said track guide obtained in said detecting step;
• and
• detecting said sequence of pits from the image signal obtained from said plurality of photoelectric conversion elements by specifying said row address or said column address of the image of said sequence of pits obtained in said calculating step, and by sequentially changing over said row address or said column address which is not specified to an address increasing by one address, on the basis of a predetermined address.

In an apparatus for reproducing information on an optical card having a plurality of tracks on its recording surface for recording information as a sequence of pits and track guides for separating the tracks, wherein said pits are detected by means of irradiating light reflected from said tracks onto a two-dimensional solid-state image sensing means, the improvement comprising:

• a binary value conversion means for converting image signals from said two-dimensional solid-state image sensing means into binary value signals;
• a track guide detection means for detecting a first address of said track guide;
• a first calculation means for calculating a second address of said sequence of pits from said first address of said track guide;
• and
• a detection means for detecting said sequence of pits from said binary valued signals outputted from said binary value converting means wherein said binary valued signals are specified by said second address.

An optical card reproducing method in which an optical card has a plurality of tracks on its recording surface for recording information as a sequence of pits and track guides for separating the tracks, wherein the pits are detected by means of irradiated light reflected from the tracks onto a two-dimensional solid-state image sensor, comprising the steps of:

• converting image signals from the two-dimensional solid-state image sensor into binary values;
• detecting a first address of the track guide;
• calculating a second address of the sequence of pits from the first address of the track guide;
• and
• detecting a sequence of pits from the binary valued signals specified by the second address.