Apparatus and method for generating halftones for image reproduction

Claim 2

Apparatus for generating halftone images for reproducing an image in halftone copy and comprising means for controlling an energy beam for forming parallel rows of halftone dot characters parallel to a reference axis and spaced from each other so as to define a pattern of dot characters, said pattern of dot characters being spaced apart to define parallel screen lines oriented at a predetermined angle relative to said axis and means for adjusting the spacing between said dot characters for correspondingly varying the said predetermined screen line angle.

Claim 3

Apparatus as set forth in claim 1, including means for varying the size of each said dot character in dependence upon an associated tone level of a portion of a said image to be reproduced.

Claim 4

Apparatus as set forth in claim 1, wherein said image to be reproduced is a continuous tone color image having a plurality of color components each of which is to be reproduced in halftone copy with screen line angles respectively associated therewith and wherein said adjusting means includes means responsive to command signals for varying the said screen line angle of said pattern of dot characters to correspond with an associated one of said color components.

Claim 5

Apparatus as set forth in claim 3, wherein said spacing means includes first spacing means for varying the spacing between the dot characters in a direction parallel to said axis and second spacing means for varying the spacing between said rows.

Claim 6

Apparatus for generating halftone images for different color components of an image to be reproduced by deflecting an energy beam as it moves along a scan line across an energy responsive surface parallel to an axis comprising means for generating halftone dot characters at predetermined spaced apart positions along said scan line with the size of said characters being dependent upon the tone level of the image to be reproduced, and means for controlling the spacing between adjacent said positions such that the spacing between said dot characters of each pattern is associated with the color component of the halftone image being reproduced.

Claim 7

Apparatus for generating halftone images for different color components of an image to be reproduced by deflecting an energy beam as it moves along a scan line across an energy responsive surface parallel to an axis comprising means for generating halftone dot characters at predetermined spaced apart positions along said scan line with the size of said characters being dependent upon the tone level of the image to be reproduced, and means for controlling the spacing between adjacent said positions such that the spacing between said dot characters of each pattern is associated with the color component of the halftone image being reproduced.

Claim 8

Apparatus as defined in claim 5, wherein said means for generating halftone characters comprises storage means for storing a plurality of sets of coded instructions, each set of coded instructions including instructions for deflecting said beam to form a respective dot character, and means for selecting sets of coded instructions and effecting deflection of said beam in accordance therewith in response to tone level signals to form dot characters at said positions along a scan line.

Claim 11

Apparatus for generating halftone images for different color components of an image to be reproduced in halftone copy by deflecting an energy beam relative to an energy responsive surface and comprising means for generating a pattern of spaced apart halftone dot characters to be recorded on said energy responsive surface with the size of said characters being dependent upon the tone level of the image to be reproduced, and means for controlling the spacing between said halftone dot characters such that the spacing is in accordance with the particular color component of the image to be reproduced in halftone copy.

Claim 12

Apparatus for generating halftone images for different color components of an image to be reproduced in halftone copy by deflecting an energy beam relative to an energy responsive surface and comprising means for generating a pattern of spaced apart halftone dot characters to be recorded on said energy responsive surface with the size of said characters being dependent upon the tone level of the image to be reproduced, and means for controlling the spacing between said halftone dot characters such that the spacing is in accordance with the particular color component of the image to be reproduced in halftone copy.

Claim 13

Apparatus as set forth in claim 8, wherein said generating means includes means for deflecting said beam to incrementally spaced dot character positions extending along dot character lines parallel to an axis with the spacing between dot character positions in a said row and the spacing between said rows being dependent upon a said color component.

Claim 14

Apparatus as set forth in claim 9, including storage means for storing a plurality of said coded instructions for deflecting said beam to form a respective dot character and means for interrogating said storage means to obtain therefrom selected sets of coded instructions for forming dot characters in dependence upon tone level signals.

Claim 15

Apparatus as set forth in claim 10, including means for effecting the deflection of said beam along a direction parallel to said axis to a first dot position for each row of dot characters wherein the said first position is dependent on a said color component.

Claim 16

Apparatus as set forth in claim 10, wherein said storage means includes means for storing coded instructions for the said incremental spacing of said dot characters in each said row of dot characters.

Claim 17

Apparatus as set forth in claim 12, including means for incrementally effecting relative positioning of said beam and said record member in a direction perpendicular to that of said axis after each row of dot characters has been formed.

Claim 18

Apparatus for reproducing continuous tone color images in halftone copy for each of a plurality of color components of a said image and comprising: means for providing a plurality of tone level signals each having a characteristic that varies with the tone level of a said color image; means for forming parallel rows of halftone dot characters on a record member in accordance with said tone level signals with said rows being spaced by a first distance and the said dot characters in each row being spaced by a second distance and said first and second distances being fixed for and dependent on the particular color component to be reproduced in halftone copy on said record member.

Claim 19

Apparatus for reproducing continuous tone color images in halftone copy for each of a plurality of color components of a said image and comprising: means for providing a plurality of tone level signals each having a characteristic that varies with the tone level of a said color image; means for forming parallel rows of halftone dot characters on a record member in accordance with said tone level signals with said rows being spaced by a first distance and the said dot characters in each row being spaced by a second distance and said first and second distances being fixed for and dependent on the particular color component to be reproduced in halftone copy on said record member.

Claim 20

Apparatus as set forth in claim 14, wherein said forming means includes means for forming said halftone characters as light images to be recorded on a light sensitive record member.

Claim 21

Apparatus as set forth in claim 15, wherein said forming means includes a cathode ray tube and beam deflection means for deflecting the cathode ray beam to form light images on the display surface of said tube which are to be recorded on a said light sensitive record member.

Claim 24

A system as set forth in claim 17, wherein said generating means includes a cathode ray tube and beam deflection means for deflecting the cathode ray beam to form said dot characters on the face of said tube to be recorded on said record member.

Claim 25

Apparatus for reproducing a continuous tone color image in halftone copy for each of the subtractive primaries: black, magenta, cyan and yellow and comprising: means for providing for each of said primary colors a pattern of tone level signals representative of relative tone levels of a said image to be reproduced; character memory means for storing instructions for forming different dot characters of varying size representative of different tone levels; means for interrogating said memory means in accordance with said tone level signals to obtain corresponding ones of said forming instructions; and means for forming said dot characters on a record member in dependence upon said corresponding forming instructions with said dot characters being sequentially formed along a line parallel to one of two mutually perpendicular coordinate axes and spaced apart along said line by a distance associated with a selected one of said colors.

Claim 26

Apparatus for reproducing a continuous tone color image in halftone copy for each of the subtractive primaries: black, magenta, cyan and yellow and comprising: means for providing for each of said primary colors a pattern of tone level signals representative of relative tone levels of a said image to be reproduced; character memory means for storing instructions for forming different dot characters of varying size representative of different tone levels; means for interrogating said memory means in accordance with said tone level signals to obtain corresponding ones of said forming instructions; and means for forming said dot characters on a record member in dependence upon said corresponding forming instructions with said dot characters being sequentially formed along a line parallel to one of two mutually perpendicular coordinate axes and spaced apart along said line by a distance associated with a selected one of said colors.

Claim 27

Apparatus as set forth in claim 19, wherein said dot characters are formed along lines parallel to said first line with the first character in each line being offset from a common reference location by a distance dependent upon the selected one of said colors and means for effecting said offset in response to offset commands.

Claim 28

Apparatus as set forth in claim 19, wherein said forming means includes means for projecting an energy beam onto a said record member which is responsive thereto to define said dot characters, and deflecting means for deflecting said beam parallel to each of said coordinate axis in response to beam deflection signals.

Claim 29

Apparatus as set forth in claim 19, wherein additional said dot characters are formed along lines parallel to said first line with adjacent lines being spaced apart by a distance associated with the selected one of said colors and means for effecting said spacing in response to line spacing commands.

Claim 30

Apparatus as set forth in claim 22, wherein said spacing means includes means for displacing said record member perpendicularly relative to said parallel lines.

Claim 31

In a phototypesetting apparatus for forming a halftone exhibiting a pattern of dot characters defining screen lines extending parallel to each other with said screen lines being uniformly spaced apart by a predetermined distance and extending along a predetermined angle relative to one of two mutually perpendicular axes and comprising: dot character memory means for storing dot character forming instructions for forming dot characters on an energy responsive record member of varying sizes corresponding to varying tone levels; means for interrogating said memory means to obtain therefrom dot forming instructions corresponding to desired tone levels in response to dot character command signals; an energy responsive record member; means for projecting an energy beam onto said record member which is responsive to said beam, when unblanked, to form images thereon; means for deflecting said beam parallel to each of said perpendicular axes in accordance with deflection signals; dot character generating means for applying character generating deflection signals to said deflecting means for forming dot characters on said record member in dependence upon said dot forming instructioNs; means for applying dot character positioning deflection signals to said deflection means for sequentially positioning said dot characters along a line parallel to one of said axes and spaced apart along said line in dependence upon said predetermined angle; means for advancing said record member perpendicular to said one axis by a distance dependent upon said predetermined angle; and means for applying an offsetting dot character positioning deflection signal to said deflection means for offsetting the position of the first dot character in a second said line of dot characters from that of the first dot character in said first line of dot characters in dependence upon offset command signals.

Claim 32

In a phototypesetting apparatus for forming a halftone exhibiting a pattern of dot characters defining screen lines extending parallel to each other with said screen lines being uniformly spaced apart by a predetermined distance and extending along a predetermined angle relative to one of two mutually perpendicular axes and comprising: dot character memory means for storing dot character forming instructions for forming dot characters on an energy responsive record member of varying sizes corresponding to varying tone levels; means for interrogating said memory means to obtain therefrom dot forming instructions corresponding to desired tone levels in response to dot character command signals; an energy responsive record member; means for projecting an energy beam onto said record member which is responsive to said beam, when unblanked, to form images thereon; means for deflecting said beam parallel to each of said perpendicular axes in accordance with deflection signals; dot character generating means for applying character generating deflection signals to said deflecting means for forming dot characters on said record member in dependence upon said dot forming instructioNs; means for applying dot character positioning deflection signals to said deflection means for sequentially positioning said dot characters along a line parallel to one of said axes and spaced apart along said line in dependence upon said predetermined angle; means for advancing said record member perpendicular to said one axis by a distance dependent upon said predetermined angle; and means for applying an offsetting dot character positioning deflection signal to said deflection means for offsetting the position of the first dot character in a second said line of dot characters from that of the first dot character in said first line of dot characters in dependence upon offset command signals.