Optical information recording and reproducing apparatus having reproducing light beams radiated onto regions situated behind and in front of a spot formed by a recording light beam

An optical information recording/reproducing apparatus, comprising:

• a first light source for generating a recording light beam that illuminates an optical recording medium, for recording information;
• a second light source for generating a reproducing light beam that illuminates said optical recording medium, and uses light reflected from the medium to reproduce recorded information;
• an optical means located on a light path of said reproducing light beam so as to radiate said reproducing light beam originating from said second light source to regions on said optical recording medium that include at least one track and at least one track guide on said optical recording medium, wherein said track contains a spot of a recording light beam originating from said first light source, said regions being situated behind and in front of said recording light beam spot relative to the direction of movement of said recording light beam;
• and
• a tracking error signal generating means that uses light of said reproducing light beam reflected from said optical recording medium to generate a tracking error signal which helps said recording light beam to track a recording track on said recording medium,
• wherein said tracking error signal generating means includes a plurality of photodetector means that form an image from said optical recording medium onto which said reproducing light beam is radiated at positions on respective sides of a spot formed by said recording light beam,
• wherein said plurality of photodetector means have a first photodetector means for detecting said reproducing light beam positioned in front of said spot formed by said recording light beam and a second photodetector means for detecting said reproducing light beam positioned at the rear of said spot formed by said recording light beam, said first photodetector means and said second photodetector means are arranged so as to receive a same image centered upon said guide track, and wherein said first photodetector means and said second photodetector means are arranged with said spot formed by said recording light beam being incident upon a plane including said first photodetector means and said second photodetector means as a center, located in parallel with respect to a direction of movement of said spot formed by said recording light beam and positioned at approximately equal distances from the direction of movement of said spot formed by said recording light beam;
• a tracking error signal calculating means that processes signals detected by said plurality of photodetector means and outputs a tracking error signal calculated in accordance therewith, wherein said tracking error signal calculating means includes means for calculating a first tracking error signal by calculating outputs from said first photodetector means, means for calculating a second tracking error signal by calculating outputs from said second photodetector means, and means for calculating a third tracking error signal by averaging said first tracking error signal and said second tracking error signal wherein said third tracking error signal represents an amount of skew of said recording track at a position of said recording light beam spot.