Document copying apparatus

In a document copying apparatus of the type including (1) reading means for generating a plurality of electrical signals which are serial measures of imagewise information of successive discrete areas of an original document to be reproduced, (2) image recording means responsive to applied electrical signals for forming discrete image portions on a receiver medium corresponding to the imagewise information contained in said applied electrical signals, and (3) control means associated with said reading means and said recording means for controlling the format of the recording of said discrete image portions so that the relative position of each such image portion on the receiver medium corresponds to the relative position of its respective counterpart area of the original document;

• the improvement comprising programmed computation means for (1) receiving said generated signals, (2) applying a compensating function to said generated signals to modify the imagewise information contained therein and (3) applying the compensated signals to said image recording means;
• said computation means including means for correcting for color saturation losses in the original document.

In a document copying apparatus of the type including (1) reading means for generating a plurality of electrical signals which are serial measures of imagewise information of successive discrete areas of an original document to be reproduced, (2) image recording means responsive to applied electrical signals for forming discrete image portions on a receiver medium corresponding to the imagewise information contained in said applied electrical signals, and (3) control means associated with said reading means and said recording means for controlling the format of the recording of said discrete image portions so that the relative position of each such image portion on the receiver medium corresponds to the relative position of its respective counterpart area of the original document;

• the improvement comprising programmed computation means for (1) receiving said generated signals, (2) applying a compensating function to said generated signals to modify the imagewise information contained therein and (3) applying the compensated signals to said image recording means;
• said computation means including means for correcting for characteristics of hue in the original document.

In a document copying apparatus of the type including (1) reading means for generating a plurality of electrical signals which are serial measures of imagewise information of successive discrete areas of an original document to be reproduced, (2) image recording means responsive to applied electrical signals for forming discrete image portions on a receiver medium corresponding to the imagewise information contained in said applied electrical signals, and (3) control means associated with said reading means and said recording means for controlling the format of the recording of said discrete image portions so that the relative position of each such image portion on the receiver medium corresponds to the relative position of its respective counterpart area of the original document;

• the improvement comprising programmed computation means for (1 ) receiving said generated signals, (2) applying a compensating function to said generated signals to modify the imagewise information contained therein and (3) applying the compensated signals to said image recording means;
• said computation means including means for correcting for characteristics of contrast in the original document.

In a document copying apparatus of the type including (1) reading means for generating a plurality of electrical signals which are serial measures of imagewise information of successive discrete areas of an original document to be reproduced, (2) image recording means responsive to applied electrical signals for forming discrete image portions on a receiver medium corresponding to the imagewise information contained in said applied electrical signals, and (3) control means associated with said reading means and said recording means for controlling the format of the recording of said discrete image portions so that the relative position of each such image portion on the receiver medium corresponds to the relative position of its respective counterpart area of the original document;

• the improvement comprising programmed computation means for (1) receiving said generated signals, (2) applying a compensating function to said generated signals to modify the imagewise information contained therein and (3) applying the compensated signals to said image recording means;
• said computation means comprising digital table look-up means for applying said compensating function to said generated signals.

Apparatus for processing a series of input electrical signals which are linear measures of a characteristic of imagewise information of successive discrete areas on an object to be imaged, said apparatus comprising:

• means for converting said input signals to forms which are more efficient for applying a corrective function thereto;
• and
• programmed computation means for applying a corrective function to said converted input signals to produce output signals in which the imagewise information is modified from that of said input signals.

Apparatus for processing a series of input electrical signals which are linear measures of a characteristic of imagewise information of successive discrete areas of an object to be imaged, said apparatus comprising:

• means for converting said input signals to forms which are substantially linear with respect to human visual color error tolerances, whereby said converted signals are more efficient than said input signals for application to a buffer memory;
• and
• a buffer memory adapted to receive said converted signals and to store said received signals for subsequent use.

In a document copying apparatus of the type including (1) reading means for generating a plurality of electrical signals which are serial measures of imagewise information of successive discrete areas of an original document to be reproduced, (2) image recording means responsive to applied electrical signals for forming discrete image portions on a received medium, and (3) control means associated with said reading means and said recording means for controlling the format of the recording of said discrete image portions so that the relative position of each such image portion on the receiver medium corresponds to the relative position of its respective counterpart area of the original document;

• the improvement comprising electronic unsharp masking means responsive to said generated signals for suppressing undesirable noise in said generated signals.

In a document copying apparatus of the type including (1) reading means for generating a plurality of electrical signals which are serial measures of imagewise information of successive discrete areas of an original document to be reproduced, (2) image recording means responsive to applied electrical signals for forming discrete image portions on a received medium, and (3) control means associated with said reading means and said recording means for controlling the format of the recording of said discrete image portions so that the relative position of each such image portion on the receiver medium corresponds to the relative position of its respective counterpart area of the original document;

• the improvement comprising electronic unsharp masking means responsive to said generated signals for enhancing edge sharpness in the image formed by said recording means.