Film optical code reader having clock and data sensors

A code reader comprising a first and a second data sensor and a first and a second clock sensor for reading the data track and clock track of a transmissive optical bar code formed on a portion of a surface that is moved past said code reader and illuminated by a light source, is characterized in that:

• said first and second data sensors are positioned adjacent to each other, in the same plane, in the direction of surface travel and the combined width of said first and second sensors is no larger than the minimum bar space width of the optical code;
• said first and second clock sensors are positioned adjacent to each other, in the same plane, in the direction of surface travel and the combined width of said first and second data sensors is no larger than the minimum bar space width of the optical code, wherein said first and second clock sensors are offset from said first and second data sensors in the downstream direction of surface travel;
• means coupled to said data sensors for detecting optical bar code transitions by determining the ratio of the signals sensed by said data sensors;
• means coupled to said clock sensors for detecting optical bar code transitions by determining the ratio of the signals sensed by said clock sensors;
• and
• means coupled to said data and clock transitions detecting means for processing the detected data and clock transition signals to determine the information contained in the data track and clock track of the optical code.