BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to tape-controlled printing systems in general, and more particularly, relates to a system for controlling the uniformity of the right-hand edge of output copy printed from an input tape under control of the setup entry made by the operator at the beginning of the printing operation.
2. Description of the Prior Art
The art of composing is a relatively old art and in its classic sense, includes the justification of printing, such that the uniformity of both the left-hand edge and right-hand edge are controlled. While in classic composing rigid control of the right-hand edge of the output copy is required, there are many applications in which a slightly ragged right-hand edge is acceptable. There have been many systems designed to print output from an input tape with a ragged right-hand edge such that there is less of a requirement for operator intervention in the form of hyphenation decisions during printout. This is the prime reason for utilizing a system in which the right-hand edge of the output copy is not in exact alignment. However, prior to the present invention, there have been no systems in which the operator had a choice as to the degree of raggedness permissible on the right-hand edge.
U.S. Pat. No. 3,339,470 to O'Brien, et al., provides normal justification in which the textual content of the input lines is identical line-for-line with the textual content of the output lines. The only difference between input and output is that the output line is justified to the right-hand margin and the spaces to fill up to the right-hand margin are equally distributed to interword spacing. The O'Brien patent is, of course, a typical justification system.
U.S. Pat. No. 3,386,552 to Lorber, et al., provides a system in which a carrier return will automatically occur at the first space on the far side of a right-hand point set into the system by the operator. There is no variable zone in the Lorber system. The Lorber system also provides a hyphenation mode in which the input tape has the words thereon hyphenated by the input operator at every syllable and a carrier return will occur on the first hyphen on the right of the right-hand line. Additional modes of sentence, paragraph, and character are also provided. As above noted, there is, however, no provision in the Lorber system of a variable zone which the operator may vary to control the raggedness of the right-hand edge. The operator can only control the earliest point at which a carrier return can occur.
U.S. Pat. No. 3,340,986 to Adams provides a right-hand zone. This zone, however, is not controlled by the machine, but is a visual zone used by the operator viewer. The viewer runs the input tape past a viewing station and makes decisions as to what the right-hand margin should look like and marks the tape with a machine readable code to end a line at a selected point which falls between two vertical lines which designate the zone. This is facilitated by having an input tape, having measured lengths on it which can be directly correlated to the length of a line of print on the output copy. There is in the Adams system no provision for the automatic setting of the zone by the operator with substantially unattended operation of the system during the printout as is provided in the subject invention. Instead, in the Adams system the operator must go completely through the input tape marking the line endings prior to beginning the printing operation.
U.S. Pat. No. 3,307,154 to Garth describes a typical "hot zone" system. Garth provides a zone which determines where the line-ending point is to occur. However, this zone is related to a multiple of the number of interword spaces in order to control the ultimate size of these interword spaces upon justification of the line and thus, this zone varies for each line. There is no provision for the operator to control the line-ending point within a zone that is constant for each line in order to control the raggedness of the right-hand edge.
SUMMARY OF THE INVENTION
Briefly, a system is provided which accepts input data from a tape and converts the input data to printed output. The degree of evenness of the right-hand edge of the printed output is controlled by the operator setting a zone during the setup operation. During setup the operator sets both the measure and the zone width. First and second Counters are provided which hold the running count from the left-hand margin and the count from the left-hand margin at the time of the last space, respectively. A subtract-hold unit is also utilized to hold an amount equal to the measure minus the zone width which is the left-hand side of the zone.
When a space code is read from the input tape, the contents of the first counter are compared against the measure. If the space is to the right of the measure, the contents of the subtract-hold unit are compared with the contents of the second counter to determine if the previous space was in the zone. If the previous space is in the zone which is the case when the contents of the second counter are greater than the count in the subtract-hold unit, the previous space is the point of an automatic carrier return. If less, the word is printed out for a hyphenation decision since the word completely spans the zone. Thus, reading of the input tape always continues until the measure is overrun and the system then drops back to the previous space location which assures that the space nearest the edge of the measure will, in the event of multiple spaces in the zone, be the space which ends the line.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of the subject novel system;
FIG. 2 illustrates the operation of the system when a word of the input line spans the right-hand side of the control zone;
FIG. 3 illustrates the operation of the system when two spaces occur in the zone and a word spans the right-hand side of the control zone;
FIG. 4 illustrates the operation of the system when a space is at the right-hand side of the control zone;
FIG. 5 illustrates the operation of the system when the zone is chosen to be relatively narrow such that no space occurs within the zone.
DETAILED DESCRIPTION OF THE INVENTION
Refer next to FIG. 1 which shows the overall system which comprises the subject invention. The system as shown in FIG. 1 is designed to facilitate its utilization in a system in which printing of text is to be under control of a previously prepared input tape. The printing of material may follow the complete reading of a line from the input tape with justification or other modifications being made to the line prior to the printing. In this case justification occurs automatically so long as the justification can be accomplished by appropriate interword spacing and in some cases, interletter spacing. These techniques are, of course, well known. In this type of operation, whenever justification cannot be accomplished through use of the maximum permissible interword spacing and interletter spacing the last word is printed out for a hyphenation decision and this decision is then made by the operator.
In FIG. 1 is shown a count line 1 to which counts from the input tape are applied. These counts will correspond in the event of proportional spacing, to the width of the characters read from the tape and spaces read. In the event that proportional spacing is not used, the counts will correspond to the characters read and spaces. These counts are input into a current units counter 2 which is set to zero at the beginning of each line by application of a carrier return signal on lines 31 and 30 or by a startup signal when the tape reader is turned on. The contents of the current units counter 2 are applied along line 4 to an AND-gate 5. The other input to the AND-gate 5 is along line 3 from a space line. The space line is brought up anytime a space code is read from the input tape. Thus, each time a space code is read, the contents of counter 2, which are equal to the number of counts from the left-hand margin, are applied along lines 6 and 7 to the AND-gate 9 and compare unit 8, respectively. The other input to the compare unit 8 is along line 25 from the measure register 22. The measure register 22 holds a number corresponding to the setting selected by the operator at the beginning of the printing operation. This will correspond to the desired measure. The operator also sets a zone width dial to control the width of the zone. The zone width is stored in register 23.
In compare unit 8 a comparison is made between the contents of the current units counter 2 and the measure set on the measure dial. In the event that the contents of the current units counter 2 are less than the measure, which implies that the measure has not been exceeded, line 10 is brought up and the contents of counter 2 which are applied along line 6 to the AND-gate 9 are gated along line 11 into a counter 12 and stored. This counter 12 thus stores the current contents of counter 2 which is the point of the last space. The point of last space is applied along line 13 to AND-gate 14 which receives its other input from compare unit 8.
Line 15 will be brought up in the event that the contents of counter 2 are greater than the measure. This implies that the measure has been overrun. In the event that the measure has been overrun, the contents of counter 12, which is the last stored current units count, are gated through gate 14 along line 16 into a compare unit 17. The compare unit 17 receives its other input along line 20 from a subtract-hold unit 21 which is loaded initially with a count corresponding to the measure minus the zone width. The measure minus the zone width corresponds to the left-hand side of the zone. The loading of counter 21 is accomplished upon a carrier return bringing line 29 up, or upon startup. When line 29 is up, the contents of the measure register 22 and zone width register 23 are applied along lines 24 and 27, respectively, through AND-gate 26 to the subtract and hold unit 21 over line 28. In the event that upon comparison in compare unit 17, the contents of counter 12, which corresponds to the point that the last space occurred, are equal to or greater than the contents of the subtract and hold unit 21 which corresponds to the left-hand side of the zone, a carrier return will occur at the point of last space. In the event that the contents of counter 12 are less than the contents of counter 21, a printout for hyphenation signal is applied to line 19. This will occur since, in this event, the last space occurred to the left of the left-hand side of the zone and the last word, therefore, completely spans the zone.
With respect to the automatic carrier return which occurs when the measure is exceeded, which is the case when line 15 from compare unit 8 is up, it should be noted that the point at which the carrier return occurs is at the space immediately preceding the word which overflowed the measure. Thus, in the event that multiple spaces occur in the zone either due to short words, a wide zone, or multiple spaces in tabular material, the space at which the carrier return occurs is the one nearest the end of the measure. This is accomplished by storing the current units count into the point of last space counter 12 each time a space occurs.
Additionally, a carrier return signal which appears on line 18 is also applied along line 36 to AND-gate 38 to gate the point of carrier return along line 37 back to the reader control such that a new line begin point is identified. The point of carrier return which is gated is also applied along line 35 which is the other input to AND-gate 38.
Logically, the above can be described as follows:
1. Take no action until the measure is exceeded.
2. Carrier return at the point of last space if the point of last space falls within the zone and printout for hyphenation if it does not.
For a more complete understanding of the system of FIG. 1, refer next to FIG. 2 wherein is shown an illustration of an input line and an output line which would occur through operation of the subject system. In FIG. 2 the input line is shown with a space occuring in the zone between words C and D and with word D overflowing the measure. Upon application of this input line to the subject system, a carrier return occurs at the space following word C and word D is then brought around onto the following line.
In FIG. 3 is illustrated the case where multiple spaces occur in the zone. As shown upon output the system does not automatically cause a carrier return following a space after word C, but instead causes a carrier return after word D, which is the space nearest the right-hand margin. Word E in FIG. 3 is then brought around to the following line. This illustrates that in the subject system that the first space is not acted upon. Instead, the space nearest to the right-hand side of the measure is the space which is chosen.
In FIG. 4 is illustrated the case where a relatively long word is input and the space following the long word is at the overflow point. In this case, as illustrated, word C is printed as input.
In FIG. 5 is shown the case where a long word completely spans the zone and thus, the word must be printed out for hyphenation. Again, as illustrated in FIG. 5, hyphenation may perhaps be rejected.
From a consideration of FIG. 1, it should now be obvious that the system of FIG. 1 implements the subject novel technique in which a variable width zone is set by the operator, the width of which will control the amount of unevenness on the right-hand side of the output. If a very tight right-hand side is required, the zone will be made relatively small such that the likelihood of spaces occurring in the zone, which would cause an automatic carrier return, is lessened. The trade off here is that more words will be found to span the zone, and therefore, a greater number of hyphenation decisions will be made. At the other extreme, the zone can be made quite wide such that the likelihood of a word completely spanning the zone, which would necessitate a hyphenation decision, is almost eliminated. In this case, as above described, the evenness of the right-hand margin will be made better through use of the subject invention since only the space nearest the end of the measure will cause a carrier return. However, it should be noted that as the zone width chosen by the operator gets wider, the results achieved through use of the subject system tend to approach those achieved in a system in which a carrier return is caused to occur upon the first space to the right-hand side of a right margin line.
While the invention has been particularly shown and described with reference to several embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention.