1. A character recognition device for use with a recording medium comprising a character string comprising characters, the character recognition device comprising: an image sensor configured to image the character string on the recording medium and read the character string as image data; and a data processor configured to segment a character string from said image data, and segment the characters from said character string to implement character recognition; wherein said data processor is further configured to detect positions to segment the characters; said data processor is further configured to: set an area to detect a position for segmenting said characters; create a first projection of pixel values of the pixels arranged in the character arrangement direction along which characters are arranged and a second projection of pixel values of the pixels arranged in an orthogonal to said character arrangement direction, at least within said setting area; calculate a synthetic threshold value of a first threshold, acquired by applying a discriminant analysis method on said first, X-axis projection, and a second threshold, acquired by applying said discriminant analysis method on said second, Y-axis projection, and take it as a binary threshold for said setting area; and acquire character segmenting positions based on said binary threshold.