Method and an apparatus for limited variable speed scanning

Claim 1

An apparatus for scanning a page of information at multiple vertical resolutions which comprises: line scanning means for scanning successive lines of information at a predetermined design velocity, V p .sbsb.d, a predetermined design resolution, R v .sbsb.d and a predetermined exposure time per line, t ; resolution selection means for selecting a desired scanning resolution, R v ; system processor means, being connected to the resolution selection means and configured for determining a data retention coefficient, K r , expressed in terms of a fraction and determining a new velocity for the line scanning means, the system processor means further being configured to determine the new velocity which is equal to the product of the data retention coefficient, K r , the inverse of the desired scanning resolution, R v , and the inverse of the exposure time, t ; scanning velocity control means, being connected to the line scanning means and the system processor means, for driving the line scanning means at the new velocity; and data rejection means being connected to the system processor means and the scanning means for rejecting lines of data according to the data retention coefficient, K r , where the numerator of the fraction represents the total number of lines retained out of the denominator, which represents a particular number of lines scanned.

Claim 2

An apparatus for scanning a page of information at multiple vertical resolutions which comprises: line scanning means for scanning successive lines of information at a predetermined design velocity, V p .sbsb.d, a predetermined design resolution, R v .sbsb.d and a predetermined exposure time per line, t ; resolution selection means for selecting a desired scanning resolution, R v ; system processor means, being connected to the resolution selection means and configured for determining a data retention coefficient, K r , expressed in terms of a fraction and determining a new velocity for the line scanning means, the system processor means further being configured to determine the new velocity which is equal to the product of the data retention coefficient, K r , the inverse of the desired scanning resolution, R v , and the inverse of the exposure time, t ; scanning velocity control means, being connected to the line scanning means and the system processor means, for driving the line scanning means at the new velocity; and data rejection means being connected to the system processor means and the scanning means for rejecting lines of data according to the data retention coefficient, K r , where the numerator of the fraction represents the total number of lines retained out of the denominator, which represents a particular number of lines scanned.

Claim 3

A method for scanning at multiple resolutions using a scanning apparatus having a scanner mechanism, means for generating relative motion between the scanner mechanism and a page containing information, to facilitate scanning successive lines of information at a predetermined design velocity, V p .sbsb.d, a predetermined design resolution, R v .sbsb.d and a predetermined exposure time per line, t, comprising the steps of: inputting a desired resolution, R v ; determining a data retention coefficient K r expressed in terms of a fraction, by comparing resulting values of V' p , obtained from the equation ##EQU7## where V' p =vertical scanner velocity relative to the paper in terms of inches per second; R v =vertical resolution in terms of lines per inch (lpi); t=exposure time per line in seconds; and K r =data retention coefficient. using various data retention coefficients between the values of 0 and 1, with the design velocity V p .sbsb.d and selecting the resulting V' p which is closest to V p .sbsb.d ; driving the means for generating relative motion at the resulting velocity V' p while scanning lines of data; and rejecting lines of data according to the data retention coefficient, K r , where the numerator of the fraction represents the total number of lines retained out the denominator which represents a particular number of lines scanned.

Claim 4

A method for scanning at multiple resolutions using a scanning apparatus having a scanner mechanism, means for generating relative motion between the scanner mechanism and a page containing information, to facilitate scanning successive lines of information at a predetermined design velocity, V p .sbsb.d, a predetermined design resolution, R v .sbsb.d and a predetermined exposure time per line, t, comprising the steps of: inputting a desired resolution, R v ; determining a data retention coefficient K r expressed in terms of a fraction, by comparing resulting values of V' p , obtained from the equation ##EQU7## where V' p =vertical scanner velocity relative to the paper in terms of inches per second; R v =vertical resolution in terms of lines per inch (lpi); t=exposure time per line in seconds; and K r =data retention coefficient. using various data retention coefficients between the values of 0 and 1, with the design velocity V p .sbsb.d and selecting the resulting V' p which is closest to V p .sbsb.d ; driving the means for generating relative motion at the resulting velocity V' p while scanning lines of data; and rejecting lines of data according to the data retention coefficient, K r , where the numerator of the fraction represents the total number of lines retained out the denominator which represents a particular number of lines scanned.

Claim 5

A method for scanning at multiple resolutions using a scanning apparatus having a scanner mechanism, means for generating relative motion between the scanner mechanism and a page containing information, to facilitate scanning successive lines of information at a predetermined design velocity, V p .sbsb.d, a predetermined design resolution, R v .sbsb.d and a predetermined exposure time per line, t, comprising the steps of: inputting a desired resolution, R v ; determining a data retention coefficient, K r , expressed in terms of a fraction, by comparing resulting values of V' p , obtained from the equation ##EQU8## where V' p =vertical scanner velocity relative to the paper in terms of inches per second; R v =vertical resolution in terms of lines per inch (lpi); t=exposure time per line in seconds; and K r =data retention coefficient. using various data retention coefficients between the values of 0 and 1 with the design velocity V p .sbsb.d and selecting the resulting V' p which is both within 60% of V p .sbsb.d and has a corresponding K r which is greatest of the group of data retention coefficients which satisfy these conditions; driving the means for generating relative motion at the resulting velocity V' p while scanning lines of data; and rejecting lines of data according to the data retention coefficient, K r , where the numerator of the fraction represents the total number of lines retained out the denominator which represents a particular number of lines scanned.

Claim 6

A method for scanning at multiple resolutions using a scanning apparatus having a scanner mechanism, means for generating relative motion between the scanner mechanism and a page containing information, to facilitate scanning successive lines of information at a predetermined design velocity, V p .sbsb.d, a predetermined design resolution, R v .sbsb.d and a predetermined exposure time per line, t, comprising the steps of: inputting a desired resolution, R v ; determining a data retention coefficient, K r , expressed in terms of a fraction, by comparing resulting values of V' p , obtained from the equation ##EQU8## where V' p =vertical scanner velocity relative to the paper in terms of inches per second; R v =vertical resolution in terms of lines per inch (lpi); t=exposure time per line in seconds; and K r =data retention coefficient. using various data retention coefficients between the values of 0 and 1 with the design velocity V p .sbsb.d and selecting the resulting V' p which is both within 60% of V p .sbsb.d and has a corresponding K r which is greatest of the group of data retention coefficients which satisfy these conditions; driving the means for generating relative motion at the resulting velocity V' p while scanning lines of data; and rejecting lines of data according to the data retention coefficient, K r , where the numerator of the fraction represents the total number of lines retained out the denominator which represents a particular number of lines scanned.