Small reliable image input apparatus incorporated in finger-print collation system of personal identification

An image input device for producing a piece of data information representative of a fingerprint of a finger of a living body, comprising:

• a transparent optical guide plate including a first surface having an detecting area where said living body presses said finger, and radiating a reflection representative of an image of said fingerprint from a second surface to the outside thereof;
• a light source radiating light into said transparent optical guide so as to illuminate said detecting area;
• an image pickup device provided in the vicinity of said second surface, and having an incident surface so as to detect said reflection;
• a gradient index lens array provided between said second surface and said image pickup device so as to form said image on said incident surface;
• and
• a case for accommodating said transparent optical plate, said light source, said image pickup device and said image forming mean.

An image input device for producing a piece of data information representative of a fingerprint of a finger of a living body, comprising:

• a transparent optical guide plate including a first surface having an detecting area where said living body presses said finger, and radiating a reflection representative of an image of said fingerprint from a second surface to the outside thereof;
• a light source radiating light into said transparent optical guide so as to illuminate said detecting area;
• an image pickup device provided in the vicinity of said second surface, and having an incident surface so as to detect said reflection;
• an image forming means provided between said second surface and said image pickup device so as to form said image on said incident surface;
• a case for accommodating said transparent optical plate, said light source, said image pickup device and said image forming mean;
• and
• an eliminating means for eliminating a sub-piece of data information representative of a sub-image of valley lines of said fingerprint from said piece of data information representative of said fingerprint.

An image input device for producing a piece of data information representative of a fingerprint of a finger, comprising:

• a transparent optical guide plate including a first surface having an detecting area where said finger is pressed, and radiating a reflection representative of an image of said fingerprint from a second surface to the outside thereof;
• a light source radiating light into said transparent optical guide so as to illuminate said detecting area;
• an image pickup device provided in the vicinity of said second surface, and having an incident surface so as to detect said reflection;
• a gradient index lens array provided between said second surface and said image pickup device so as to form said image on said incident surface;
• a case for accommodating said transparent optical plate, said light source, said image pickup device and said image forming mean;
• and
• a biological information discriminating means checking said reflection to see whether or not said finger changes the reflective index with time so as to produce another piece of data information representative of a living body or non-living body.