Laser phototypesetter

Claim 2

In a laser phototypesetting system for imaging selected characters from a moving character carrier onto a recording medium which is stationary during character imaging periods, the improvement comprising; a. An acousto-optical cell in the path of the laser beam; and b. electronic means for applying a frequency-modulated and amplitude-modulated drive signal to said cell to simultaneously periodically deflect the beam in accordance with the modulation frequency to scan portions of a selected character sequentially and intensity modulate the beam in accordance with the amplitude modulation to regulate the uniformity of the intensity of the beam.

Claim 3

the improved laser phototypesetting system as defined in claim 1 further comprising lens means in the path of the laser beam for forming the laser beam into a light slit which sequentially illuminates portions of characters on the carrier to form corresponding character images.

Claim 4

The improved laser phototypesetting system as defined in claim 1 further comprising photoelectric means in the path of the laser beam for sampling the intensity of the beam and for producing a corresponding feedback control signal for varying the amplitude modulation of the cell drive signal to regulate the intensity of the beam.

Claim 5

The improved laser phototypesetting system as defined in claim 1 wherein the character carrier is a rotating disc carrying characters at different radial distances from the axis of rotation of said disc, and further comprising means for varying the modulating frequency of the cell drive signal in accordance with the radial distance of each selected character, whereby the sizes of all character images are the same.

Claim 6

In a laser phototypesetting system for imaging selected characters from a moving character carrier onto a recording medium, the improvement comprising: a. means forming a pulsed laser beam; b. means in the path of the laser beam for forming the beam into a light slit having a width substantially narrower than the width of the character; c. means for supporting the recording medium relatively stationary during character imaging periods; d. electronic means having no mechanical inertia for sweeping the light slit across the width of a selected character to illuminate portions of the selected character sequentially to permit longer exposure of the character while producing a very bright character image with minimum blurring and to minimize interference fringes; and e. photoelectric means in the path of the laser beam for sampling the intensity of the beam and for producing a corresponding feedback control signal for varying the amplitude modulation of the cell drive signal to regulate the intensity of the beam.

Claim 7

In a laser phototypesetting system for imaging selected characters from a moving character carrier onto a recording medium, the improvement comprising: a. means forming a pulsed laser beam; b. means in the path of the laser beam for forming the beam into a light slit having a width substantially narrower than the width of the character; c. means for supporting the recording medium relatively stationary during character imaging periods; d. electronic means having no mechanical inertia for sweeping the light slit across the width of a selected character to illuminate portions of the selected character sequentially to permit longer exposure of the character while producing a very bright character image with minimum blurring and to minimize interference fringes; and e. photoelectric means in the path of the laser beam for sampling the intensity of the beam and for producing a corresponding feedback control signal for varying the amplitude modulation of the cell drive signal to regulate the intensity of the beam.

Claim 8

In a laser phototypesetting system for imaging selected characters from a moving character carrier onto a recording medium, the improvement comprising: a. means forming a pulsed laser beam; b. means in the path of the laser beam for forming the beam into a light slit having a width substantially narrower than the width of the character; c. means for supporting the recording medium relatively stationary during character imaging periods; d. electronic means having no mechanical inertia for sweeping the light slit across the width of a selected character to illuminate portions of the selected character sequentially to permit longer exposure of the charactEr while producing a very bright character image with minimum blurring and to minimize interference fringes; and e. said character carrier being a rotating disc carrying characters at different radial distances from the axis of rotation of said disc, and further comprising means for varying the modulating frequency of the cell drive signal in accordance with the radial distance of each selected character, whereby the sizes of all character images are the same.

Claim 9

In a laser phototypesetting system for imaging selected characters from a moving character carrier onto a recording medium, the improvement comprising: a. means forming a pulsed laser beam; b. means in the path of the laser beam for forming the beam into a light slit having a width substantially narrower than the width of the character; c. means for supporting the recording medium relatively stationary during character imaging periods; d. electronic means having no mechanical inertia for sweeping the light slit across the width of a selected character to illuminate portions of the selected character sequentially to permit longer exposure of the charactEr while producing a very bright character image with minimum blurring and to minimize interference fringes; and e. said character carrier being a rotating disc carrying characters at different radial distances from the axis of rotation of said disc, and further comprising means for varying the modulating frequency of the cell drive signal in accordance with the radial distance of each selected character, whereby the sizes of all character images are the same.