Optical system for photographic composing apparatus

Claim 2

A photocomposition machine having a collimating and decollimating lens system wherein said decollimating lens is driven in a composition path through escapement steps, characterized in that an aerial image is provided to said collimating lens by a variable focus lens positioned to project an illuminated character to an aerial image located along an optical path passing through the variable focus lens, collimating lens and decollimating lens, means for moving said variable focus lens parallel to the optical path relative to a character font for providing an aerial image of preselected size, processor means responsive to the preselected size for selecting the proper positions for the collimating lens and variable focus lens; and stepper means for moving in discrete steps the collimating lens and variable focus lens to the positions selected by the processor means in order to focus the aerial image onto the focal plane of said collimating lens.

Claim 3

A machine, as claimed in claim 1, wherein the processor means comprises memory means for enabling the proper lens positions to be selected, said memory means defining a lookup table accessed by the processor means in response to selection of the preselected size.

Claim 4

A machine, as claimed in claim 2, wherein the processor means generates position command data representative of the number of discrete steps required to move the variable focus lens and the collimating lens into the positions selected by the processor means.

Claim 5

A machine, as claimed in claim 3, wherein the stepper means comprises: stepper motor means for moving the variable focus lens and collimating lens in discrete steps; counter means for storing the position command data; and clock means for operating the counter means and enabling the stepper motor means to move the variable focus lens and collimating lens in discrete steps until the counter means attains a predetermined count.

Claim 6

In a photocomposition machine including font means for providing at least one font of a plurality of characters, projection light source means for successively illuminating preselected characters of said font means so that the characters are projected along an optical path to a print plane, a photosensitive receiving sheet located in the print plane, and input means for generating point size data representative of the point size of a character selected by an operator for photocomposition from a plurality of available point sizes, improved apparatus for accurately focusing characters at the selected point size onto the receiving sheet comprising: variator lens means for successively forming a plurality of aerial images representing a plurality of degrees of magnification of said preselected characters by movement of said variator lens means parallel to the optical path into a plurality of different composing positions; collimator lens means movable parallel to the optical path into a plurality of different composing positions in which the aerial image forms an object image for the collimator lens means, so that collimated light rays are formed; decollimator lens means responsive to the collimated light rays for focusing a print image corresponding to the aerial image on the receiving sheet and for moving parallel to the optical path to provide escapement for the preselected characters; processor means for selecting from the point size data the proper composing positions for the variator lens means and the collimator lens means in order to focus characters onto the receiving sheet at the selected point size; and stepper means for moving the variator lens means and the collimator lens means to the proper composing positions in discrete steps in response to the selecting of the processor means.

Claim 7

In a photocomposition machine including font means for providing at least one font of a plurality of characters, projection light source means for successively illuminating preselected characters of said font means so that the characters are projected along an optical path to a print plane, a photosensitive receiving sheet located in the print plane, and input means for generating point size data representative of the point size of a character selected by an operator for photocomposition from a plurality of available point sizes, improved apparatus for accurately focusing characters at the selected point size onto the receiving sheet comprising: variator lens means for successively forming a plurality of aerial images representing a plurality of degrees of magnification of said preselected characters by movement of said variator lens means parallel to the optical path into a plurality of different composing positions; collimator lens means movable parallel to the optical path into a plurality of different composing positions in which the aerial image forms an object image for the collimator lens means, so that collimated light rays are formed; decollimator lens means responsive to the collimated light rays for focusing a print image corresponding to the aerial image on the receiving sheet and for moving parallel to the optical path to provide escapement for the preselected characters; processor means for selecting from the point size data the proper composing positions for the variator lens means and the collimator lens means in order to focus characters onto the receiving sheet at the selected point size; and stepper means for moving the variator lens means and the collimator lens means to the proper composing positions in discrete steps in response to the selecting of the processor means.

Claim 8

Apparatus, as claimed in claim 5, wherein the processor means comprises memory means for enabling the proper composing positions to be selected, said memory means defining a lookup table accessed by the processor means in response to the point size data.

Claim 9

Apparatus, as claimed in claim 6, wherein the processor means generates position command data representative of the number of discrete steps required to move the variator lens means and collimator lens means into the composing positions.

Claim 10

Apparatus, as claimed in claim 7, wherein the stepper means comprises: stepper motor means for moving the variator lens means and collimator lens means in discrete steps; counter means for storing the position command data; and clock means for operating the counter means and enabling the stepper motor means to move the variator lens means and collimator lens means in discrete steps until the counter means attains a predetermined count.