Character spacing system for phototypesetting

Claim 2

In a phototypesetting machine having a character projection system forming image bearing light beams, a photosensitive material on which the images are recorded to form lines of composition, and a spacer operative to locate the images on the photosensitive material forming words and interword spaces making up justified lines, the improvement comprising a position control system including a register for storing a unique code identifying the location of the next individual character image to be formed in a line, a servo motor incorporated in said spacer and connected to said position control system to cause variable spacing movement according to location codes in said control system, a position encoder driven by said servo motor and capable of generating unique codes within the entire line for a series of incremental servo motor positions in achieving designated locations within the limits of a line of composition, and a feedback control from said encoder to said position control system.

Claim 3

A spacer for phototypesetting as defined in claim 1, wherein said spacer includes a rotatable reflecting means driven by said servo motor, and said encoder produces an output identifying the angular position of said reflecting means.

Claim 4

A spacer for phototypesetting as defined in claim 1, including a memory for storing character identification codes for a line of characters, a selector operated from said identification codes and driving said projection system to form character images in the proper sequence, a character width memory, and means ooperative in conjunction with said selector to add an appropriate width value to said register whereby the servo motor advances to the correct position for locating the next character image.

Claim 5

In a phototypesetting machine having a character projection system forming image bearing light beams, a photosensitive material on which the images are recorded to form lines of composition, a spacer member operative to direct the images onto the photosensitive material to form words and interword spaces making up lines of composition, and means for generating digital codes representing the space occupied by each character image and the space allotted to interword spaces, the improvement comprising a position control system including a register receiving digital codes as the individual character images are forMed in the line, said register operating to sum the digital codes into a unique location code defining the position of each character with respect to one end of the line, a servo motor driving said spacer member to cause variable spacing movement according to location codes in said register, a position encoder driven by said servo motor and capable of generating unique digital position codes for a series of incremental spacer member positions in achieving designated positions within the limits of a line of composition, a subtractor circuit comparing the codes from said register and the codes generated by said encoder and functioning to produce a difference signal, a digital to analog converter receiving said difference signal and providing a corresponding analog output to drive said servo motor, and a detector circuit also responsive to said difference signal for indicating coincidence between the location codes and the position codes signifying completion of a spacing operation.

Claim 6

In a phototypesetting machine having a character projection system forming image bearing light beams, a photosensitive material on which the images are recorded to form lines of composition, a spacer member operative to direct the images onto the photosensitive material to form words and interword spaces making up lines of composition, and means for generating digital codes representing the space occupied by each character image and the space allotted to interword spaces, the improvement comprising a position control system including a register receiving digital codes as the individual character images are forMed in the line, said register operating to sum the digital codes into a unique location code defining the position of each character with respect to one end of the line, a servo motor driving said spacer member to cause variable spacing movement according to location codes in said register, a position encoder driven by said servo motor and capable of generating unique digital position codes for a series of incremental spacer member positions in achieving designated positions within the limits of a line of composition, a subtractor circuit comparing the codes from said register and the codes generated by said encoder and functioning to produce a difference signal, a digital to analog converter receiving said difference signal and providing a corresponding analog output to drive said servo motor, and a detector circuit also responsive to said difference signal for indicating coincidence between the location codes and the position codes signifying completion of a spacing operation.

Claim 7

A phototypesetting machine as defined in claim 4, said spacer member being a rotatable reflector member connected to assume unique angular positions under control of said servo motor, and an inhibiting control connection from said position control system to said character projection system to prevent projection of a character image while said reflecting member is moving to its next position.

Claim 8

A phototypesetting machine as defined in claim 5, said encoder being an optical shaft encoder rotatable in unison with said reflector member.

Claim 9

A phototypesetting machine as defined in claim 4, said means for generating space codes including a memory for storing relative width codes for each character, and a point size multiplier receiving width codes from said memory and sending actual image width codes to said register.

Claim 10

In a phototypesetting machine having a character projection system, a photosensitive material on which images are successively recorded to form lines of composition, an optical system between said projection system and said material including a scan lens operative to focus on said material across the entire width of a line, a spacer member incorporated in said optical system and operative to direct light through said scan lens to form words and interword spaces making up lines of composition, and means for generating digital codes representing the space occupied by each character image and the space allotted to interword spaces in the lines of composition; the improvement comprising a register receiving digital codes as the individual character images are formed in the line and operating to sum the digital codes into a unique location code defining the position of each character with respect to one end of the line, a servo motor driving said spacer member to cause variable spacing movement thereof according to location codes in said register, a position encoder driven by said servo motor and generating unique digital position codes for a series of incremental spacer member positions in achieving designated positions along a line of composition, a subtractor circuit comparing the codes from said register and the codes generated by said encoder and functioning to produce a difference signal, a digital to analog converter receiving said difference signal and providing a corresponding analog output to drive said servo motor, a detector circuit also responsive to said difference signal for indicating coincidence between the location codes and the position codes signifying completion of a spacing operation, and an inhibiting circuit responsive to said detector circuit and connected to inhibit operation of said character projection system until a spacing operation is complete.

Claim 11

In a phototypesetting machine having a character projection system, a photosensitive material on which images are successively recorded to form lines of composition, an optical system between said projection system and said material including a scan lens operative to focus on said material across the entire width of a line, a spacer member incorporated in said optical system and operative to direct light through said scan lens to form words and interword spaces making up lines of composition, and means for generating digital codes representing the space occupied by each character image and the space allotted to interword spaces in the lines of composition; the improvement comprising a register receiving digital codes as the individual character images are formed in the line and operating to sum the digital codes into a unique location code defining the position of each character with respect to one end of the line, a servo motor driving said spacer member to cause variable spacing movement thereof according to location codes in said register, a position encoder driven by said servo motor and generating unique digital position codes for a series of incremental spacer member positions in achieving designated positions along a line of composition, a subtractor circuit comparing the codes from said register and the codes generated by said encoder and functioning to produce a difference signal, a digital to analog converter receiving said difference signal and providing a corresponding analog output to drive said servo motor, a detector circuit also responsive to said difference signal for indicating coincidence between the location codes and the position codes signifying completion of a spacing operation, and an inhibiting circuit responsive to said detector circuit and connected to inhibit operation of said character projection system until a spacing operation is complete.