Data converting apparatus having means for changing ornamental stroke end data of character outline

Claims

What is claimed is:

1. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which defines a profile of an ornamental end portion of an ornamented stroke of said character, said batch outline data further comprising ornament indicator data which indicates that said ornamental end data defines said profile of said ornamental end portion, said ornamental end data converting means being responsive to said ornament indicator data to convert said ornamental end data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke.

2. A data converting apparatus according to claim 1, wherein said outline data of said character comprising said ornamental end data is converted into one of a plurality of batches of dot data which corresponds to a selected one of a plurality of different sizes of said character, said apparatus further comprising means for activating said ornamental end data converting means only when said selected one size of said character is smaller than a predetermined reference value.

3. A data converting apparatus according to claim 1, wherein said ornamental end data converting means comprises:

ornamental pattern data memory means for storing ornamental pattern data representative of dots which correspond to said ornamental end portion of said ornamented stroke; and

ornamental dot data preparing means for converting said ornamental end data of said outline data into said predetermined block of dot data, according to said ornamental pattern data.

4. A data converting apparatus according to claim 3, wherein said ornamental end data of said outline data represents a semicircular profile of said ornamental end portion of said ornamented stroke.

5. A data converting apparatus according to claim 3, wherein said ornamental pattern data memory means stores a plurality of sets of ornamental pattern data which correspond to a plurality of widths of said ornamented stroke of the character.

6. A data converting apparatus according to claim 3, wherein said ornamental pattern data memory means stores a plurality of sets of ornamental pattern data which correspond to a right end, a left end, an upper end and a lower end of said ornamented stroke of the character, said ornamental end portion of said ornamented stroke having one of said right, left, upper and lower ends.

7. A data converting apparatus according to claim 3, wherein said ornamental pattern data comprises dot data solely representative of dots which define a profile of said ornamental end portion of said ornamented stroke.

8. A data converting apparatus according to claim 3, wherein said each set of segment data of said outline data includes coordinate data representative of a beginning of said corresponding segment of said outline of the character and coordinate data representative of an end of said corresponding segment, said outline data including two sets of segment data representative of two segments which are connected by a segment defining a profile of said ornamental end portion of said ornamented stroke defined by said ornamental end data, such that the end of one of said two segments is connected to said segment defining the profile of said ornamental end portion, said ornamental pattern data comprising coordinate data representing coordinates of the dots defining said profile of said ornamental end portion, with said end of said one of said two segments being used as an origin of said coordinates.

9. A data converting apparatus according to claim 1, wherein said ornamental end data converting means comprises:

data converting means for converting said ornamental end data of said outline data into straight line data representative of a straight line; and

ornamental dot data preparing means for preparing said predetermined block of dot data, according to said straight line data.

10. A data converting apparatus according to claim 9, wherein said ornamental end portion of said ornamented stroke has a profile defined by a segment which connects two segments which define a width of said ornamental end portion, said segment defining said profile connecting an end of one of said two segments and a beginning of other of said two segments, said straight line data prepared by said data converting means representing a straight line which connects said end of said one of said two segments and said beginning of said other of said two segments.

11. A data converting apparatus according to claim 9, wherein said ornamental end portion of said ornamented stroke has a profile defined by a segment which connects two segments which define a width of said ornamental end portion, said segment defining said profile connecting an end of one of said two segments and a beginning of other of said two segments, said straight line data prepared by said data converting means representing a straight line which is spaced a predetermined distance from said end and said beginning of said two segments, in a direction from a beginning of said one of said two segments toward said end of said one of said two segments.

12. A data converting apparatus according to claim 1, wherein said ornamental end portion of said ornamented stroke of the character consists of an end portion of a serif placed at one end of a main stroke of said character.

13. A data converting apparatus according to claim 1, wherein said ornamental end portion of said ornamented stroke of the character consists of a serif placed at one end of a main stroke of said character, said ornamental end data converting means converting said batch of outline data of the character, into a batch of outline data which includes converted segment data representative of an end portion of said main stroke without said serif as said ornamental end portion, said ornamental end data converting means converting said converted segment data into said predetermined block of dot data.

14. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at lest one of said multiple sets of segment data comprising at least one of said multiple sets of segment data of said outline which represents an ornamental end portion of an ornamented stroke of said character, said ornamental end data converting means converting said ornamental end data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, said outline data of said character comprising said ornamental end data being converted into one of a plurality of batches of dot data which corresponds to a selected one of a plurality of different sizes of said character; and

means for activating said ornamental end data converting means only when said selected one size of said character is smaller than a predetermined reference value.

15. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamental stroke of said character, said ornamental end data converting means converting said ornamental end data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, said ornamental end data of said outline data representing a semicircular profile of said ornamental end portion of said ornamented stroke; and

said ornamental end data converting means comprising ornamental pattern data memory means for storing ornamental pattern data representative of dots which correspond to said ornamental end portion of said ornamented stroke, and ornamental dot data preparing means for converting said ornamental end data of said outline data into said predetermined block of dot data, according to said ornamental pattern data.

16. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character; and

said ornamental end data converting means comprising ornamental pattern data memory means for storing ornamental pattern data representative of dots which correspond to said ornamental end portion of said ornamented stroke, said ornamental pattern data comprising a plurality of sets of ornamental pattern data which correspond to a plurality of widths of solely said ornamental end portion of the character, said ornamental end data converting means further comprising ornamental dot data preparing means for converting said ornamental end data of said outline data into a predetermined block of dot data associated with said ornamental pattern data.

17. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character; and

said ornamental end data converting means comprising ornamental pattern data memory means for storing ornamental pattern data representative of dots which correspond to said ornamental end portion of said ornamented stroke, said ornamental pattern data comprising a plurality of sets or ornamental pattern data which correspond to a right end, a left end, an upper end and a lower end of the character, said ornamental end portion of said ornamented stroke having one of said right, left, upper and lower ends, said ornamental end data converting means further comprising ornamental dot data preparing means for converting said ornamental end data of said outline data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, according to said ornamental pattern data.

18. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture element which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at lest one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character; and

said ornamental end data converting means comprising ornamental pattern data memory means for storing ornamental pattern data representative of dots which correspond to said ornamental end portion of said ornamented stroke, said ornamental pattern data comprising dot data solely representative of dots which define a profile of said ornamental end portion of said ornamented stroke, said ornamental end data converting means further comprising ornamental dot data preparing means for converting said ornamental end data of said outline date into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, according to said ornamental pattern data.

19. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character;

said ornamental end data converting means comprising ornamental pattern data memory means for storing ornamental pattern data representative of dots which correspond to said ornamental end portion of said ornamented stroke, and ornamental dot data preparing means for converting said ornamental end data of said outlined data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, according to said ornamental pattern data; and

said each set of segment data of said outline data including coordinate data representative of a beginning of said corresponding segment of said outline of said character and coordinate data representative of an end of said corresponding segment, said outline data including two sets of segment data representative of two segments which are connected by a segment defining a profile of said ornamental end portion of said ornamented stroke defined by said ornamental end data, such that the end of one of said two segments is connected to said segment defining the profile of said ornamental end portion, said ornamental pattern data comprising coordinate data representing coordinates of the dots defining said profile of said ornamental end portion, with said end of said one of said two segments being used as an origin of said coordinates.

20. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character, said ornamental end data converting means converting said ornamental end data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, said ornamental end portion of said ornamental stroke having a profile defined by a segment which connects two segments which define a width of said ornamental end portion, said segment defining said profile connecting an end of one of said two segments and a beginning of other of said two segments;

said ornamental end data converting means comprising data converting means for converting said ornamental end data of said outline data into straight line data representative of a straight line which connects said end of said one of said two segments and said beginning of said other of said two segments, said ornamental end data converting means further comprising ornamental dot data preparing means for preparing said predetermined block of dot data, according to said straight line data.

21. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character, said ornamental end data converting means converting said ornamental end data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, said ornamental end portion of said ornamental stroke having a profile defined by a segment which connects two segments which define a width of said ornamental end portion, said segment defining said profile connecting an end of one of said two segments and a beginning of other of said two segments;

said ornamental end data converting means comprising data converting means for converting said ornamental end data of said outline data into straight line data representative of a straight line which is spaced a predetermined distance from said end and said beginning of said two segments, in a direction from a beginning of said one of said two segments toward said end of said one of said two segments, said ornamental end data converting means further comprising ornamental dot data preparing means for preparing said predetermined block of dot data, according to said straight line data.

22. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character, said ornamental end portion consisting of an end portion of a serif placed at one end of a main stroke of said character, said ornamental end data converting means converting said ornamental end data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke.

23. A data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of said sets of segment data representing a corresponding segment of said outline of the character, said apparatus converting said outline data into said dot data according to a conversion rule that each stroke of said character is constituted by picture elements which lie in an outline of said stroke so as to satisfy a predetermined requirement, when said outline of said character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to said X-axis, wherein the improvement comprising:

ornamental end data converting means operable without following said conversion rule, for processing ornamental end data comprising at least one of said multiple sets of segment data of said outline data which represents an ornamental end portion of an ornamented stroke of said character, said ornamental end portion consisting of a serif placed at one end of a main stroke of said character, said ornamental end data converting means converting said ornamental end data into a predetermined block of dot data associated with said ornamental end portion of said ornamented stroke, said ornamental end data converting means converting said batch of outline data of the character, into a batch of outline data which includes converted segment data representative of an end portion of said main stroke without said serif as said ornamental end portion, said ornamental end data converting means converting said converted segment data into said predetermined block of dot data.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a data converting apparatus for converting outline data representative of an outline of a character such as a letter and a symbol, into corresponding dot data representative of the character, and more particularly to improvements in the processing of ornamental end data representative of an ornamental end portion of an ornamented stroke of the character.

2. Discussion of the Prior Art

Characters such as letters and symbols represented by character data are printed, displayed or otherwise reproduced according to the character data suitably processed by a computer. Commonly, the character data takes the form of dot data indicating whether a dot should be formed in each of picture elements which are the smallest part of picture image and determine the resolution of the reproduced image. If a batch of dot data representative of all the characters available for reproduction is prepared and stored in a character memory, the memory should have an extremely large capacity. It is therefore desirable to store a batch of outline data representative of the outlines of the characters, and convert the outline data into the corresponding dot data by suitable data converting means, when the characters are printed, displayed or otherwise reproduced, as disclosed in Japanese Patent Publication No. 53-41017.

In converting the character outline data into the corresponding dot data, a coordinated pixel screen is used. The pixel screen has an X-Y coordinate system in which the picture elements are defined by a plurality of pixel lines parallel to the X axis, and a plurality of pixel lines parallel to the Y axis perpendicular to the X axis. Each stroke of a character is constituted by the picture elements which lie in the outline of the stroke so as to meet a predetermined requirement, when the outline of the character is superimposed on the coordinated pixel screen. The dot data of the character corresponding to the outline data is prepared such that the logical values of the bits corresponding to the picture elements within the outline of the strokes of the character indicate the presence of dots which form the strokes. The outline data is prepared based on the outlines of the characters of a given typestyle, which are designed by a typeface designer. The characters are constituted by main strokes and ornamental strokes which are usually called serifs, or by main strokes only. Some strokes of the characters may be ornamented at one end or both ends of the stroke, by suitable ornaments having a semicircular, triangular or other shape, usually called serifs. Occasionally, the serifs themselves are regarded as ornaments.

Where characters are reproduced according to dot data to which the character outline data is converted by a data converting apparatus which uses a coordinated pixel screen as discussed above, the number and positions of the picture elements which lie within the outline of a stroke of a character so as to satisfy the predetermined requirement may vary, depending upon the position at which the character is printed. Further, the number and positions of the picture elements which lie in a given area within the outline of one stroke of a character may differ from those of the picture elements which lie in the similar area within the outline of another stroke of the same character, depending upon the positions of the strokes. When the number of the picture elements constituting a character is relatively small, the configuration of an ornament or an ornamental end portion of one stroke may differ from that of an ornamental end portion of another stroke, even if these two strokes have the same width. Further, the configurations of the end portions of the strokes tend to be unpleasant. The number of the picture elements constituting a character is relatively small when the character is reproduced in a relatively small size where the characters can be reproduced in different sizes. Where a stroke of a character is ornamented at its end or ends, the number of the picture elements which form the ornamental end portion of that ornamented stroke tends to be comparatively small, if the apparatus reproducing the characters has relatively low image reproduction resolution (relatively small number of picture elements per unit area). In this case, the configurations of the ornamental end portions of different strokes of the same character may remarkably differ from each other, depending upon the positions at which the strokes are reproduced, whereby the ornamental end portions of the strokes are irregularly shaped and look offensive.

The above problem is also encountered where the outline data suitable for use on an apparatus having relatively high image reproduction resolution is utilized by an apparatus which has relatively low image reproduction resolution. In this case, the ornamental end portions of the strokes cannot be reproduced as defined by the outline data.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a data converting apparatus which permits an ornamental end portion of an ornamented stroke of a character to be reproduced with improved appearance.

The above object may be attained according to the principle of the present invention, which provides a data converting apparatus for converting a batch of outline data comprising multiple sets of segment data representative of an outline of a character, into a batch of dot data representative of the character, each of the sets of segment data representing a corresponding segment of the outline of the character, the apparatus converting the outline data into the dot data according to a conversion rule that each stroke of the character is constituted by picture elements which lie in an outline of the stroke so as to satisfy a predetermined requirement, when the outline of the character is superimposed on a coordinated pixel screen wherein the picture elements are defined by a plurality of straight lines parallel to an X-axis and a plurality of straight lines parallel to a Y-axis perpendicular to the X-axis, wherein the improvement comprising ornamental end data converting means operable without following the conversion rule, for processing ornamental end data comprising at least one of the multiple sets of segment data of the outline data which represents an ornamental end portion of an ornamented stroke of the character. The ornamental end data converting means operates to convert or change the ornamental end data into a predetermined block of dot data associated with the ornamental end portion of the ornamented stroke.

In the data converting apparatus of the present invention constructed as described above, the ornamental end data representative of an ornamental end portion of an ornamented stroke of a character is converted into the predetermined dot data, which is prepared so that the dots according to the dot data form or constitute an end portion of a predetermined shape. Accordingly, the ornamental end portion of the same stroke of the same character is always reproduced in the same shape with the same number of picture elements. Thus, the quality of reproduction of the character is improved.

The data converting apparatus may be constructed such that the batch of outline data comprises the ornamental end data which defines a profile of the ornamental end portion of the ornamented stroke, and ornament indicator data which indicates that the ornamental end data defines the profile of the ornamental end portion. In this case, the ornamental end data converting means is operated in response to the ornament indicator data.

The outline data of the character comprising the ornamental data may be converted into one of a plurality of predetermined batches of dot data which corresponds to a selected one of a plurality of different sizes of the character. In this case, suitable means is provided for activating the ornamental end data converting means only when the selected one size of the character is smaller than a predetermined reference value.

The ornamental end data converting means may comprise ornamental pattern data memory means for storing ornamental pattern data representative of dots which correspond or approximates to the ornamental end portion of the ornamented stroke, and ornamental dot data preparing means for converting the ornamental end data of the outline data into the predetermined block of dot data, according to the ornamental pattern data. In this case, the ornamental pattern data is prepared so that it represents the ornamental end portion as defined by the ornamental end data of the outline data, even if the character is reproduced by a relatively small number of picture elements. Therefore, the dot data prepared based on the ornamental pattern data by the ornamental dot data preparing means permits the ornamental end portion of the relevant stroke with improved consistency in shape, even if the image reproduction resolution is relatively low.

The ornamental end data of the outline data may represent a semicircular or arcuate profile of the ornamental end portion of the ornamented stroke. The ornamental pattern data memory means may contain a plurality of sets of ornamental pattern data which correspond to a plurality of widths of the ornamented stroke of the character. Further, the ornamental pattern data memory means may store a plurality of sets of ornamental pattern data which correspond to a right end, a left end, an upper end and a lower end of the ornamented stroke of the character. The ornamental end portion may be provided at one of the right, left, upper and lower ends of the relevant stroke.

Where the ornamental pattern data memory means is provided, the ornamental pattern data may comprise dot data which represents only the dots which define a profile of the ornamental end portion of the ornamented stroke.

The data converting apparatus may be adapted such that each set of segment data of the outline data includes coordinate data representative of a beginning of the corresponding segment of the outline of the character and coordinate data representative of an end of the corresponding segment. In this case, the outline data includes two sets of segment data representative of two segments which are connected by a segment defining a profile of the ornamental end portion of the ornamented stroke defined by the ornamental end data, such that the end of one of the two segments is connected to the segment defining the profile of the ornamental end portion. The ornamental pattern data comprises coordinate data representing coordinates of the dots defining the profile of the ornamental end portion, with the end of the above-indicated one of the two segments being used as an origin of the coordinates.

The ornamental end data converting means comprises data converting means for converting the ornamental end data of the outline data into straight line data representative of a straight line, and ornamental dot data preparing means for preparing the predetermined block of dot data, according to the straight line data.

In the above form of the apparatus wherein the straight line data is used, the ornamental end portion of the ornamented stroke may have a profile defined by a segment which connects two segments which define a width of the ornamental end portion. In this instance, the segment defining the profile connects an end of one of the two segments and a beginning of other of the two segments, and the straight line data prepared by the data converting means represents a straight line which connects the end of the above-indicated one of the two segments and the beginning of the other of the two segments. According to this arrangement, the ornamental end portion defined by the ornamental end data of the outline data is removed when the outline data is prepared according to the straight line data. If the profile of the ornamental end portion is arcuate, the arcuate end of the ornamented stroke is made straight, whereby the arcuate ornamental end portion is removed. Accordingly, the relevant stroke is reproduced without an ornament at the end, and therefore the ends of the originally designed ornamented strokes of the reproduced character are made flat and appear consistent, even when the character is reproduced in a relatively small size where the characters can be reproduced in different sizes. Further, the consistent appearance of the ends of the strokes is assured even when the outline data prepared for high-resolution reproduction is used on a device which has relatively low image reproduction resolution. Thus, the present arrangement permits the batch of outline data (same memory storing the outline data) to be used for different image reproducing devices which have different levels of image reproduction resolution. This result in reduced cost of the image reproducing devices.

According to an alternative arrangement of the same form of the invention, the straight line data prepared by the data converting means represents a straight line which is spaced a predetermined distance from the end of the above-indicated one of the two segments, in a direction from a beginning of the above one segment toward the end of the same segment.

The ornamental end portion of the ornamented stroke of the character may be an end portion of a serif placed at one end of a main stroke of the character.

Alternatively, the ornamental end portion of the ornamented stroke of the character may be a serif placed at one end of a main stroke of the character. In this case, the ornamental end data converting means converts the batch of outline data of the character, into a batch of outline data which includes converted segment data representative of an end portion of the main stroke without the serif as the ornamental end portion, and the converted segment data is converted into the dot data which does not reproduce the serif.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and optional objects, features and advantages of the present invention will be better understood by reading the following detailed description of some presently preferred embodiments of the invention, when considered in connection with the accompanying drawings, in which:

FIG. 1 is a schematic block diagram showing a control circuit of a laser printer which incorporates one embodiment of a data converting apparatus of the present invention;

FIG. 2 is a schematic view of a central processing unit of the control circuit of FIG. 1;

FIG. 3 is a flow chart illustrating a data conversion routine as one of control programs stored in a PROGRAM ROM of the control circuit;

FIG. 4 is a view showing an outline of letter "F", whose outline data is converted into dot data by the data conversion apparatus according to the conversion routine of FIG. 3;

FIG. 5 is a view showing a part of a coordinated pixel screen on which the-character outline is superimposed;

FIGS. 6, 7, 8, 9, 10 and 11 are illustrations explaining different manners of determining intersections between x-axis pixel lines, and segments of the character outline which is converted into dot data by the data converting apparatus;

FIGS. 12(a)-(d), FIGS. 13(a)-(d) and FIGS. 14(a)-(d) are views indicating different patterns in a coordinate system, which are defined by respective sets of ornamental pattern data, and which correspond to arcuate end portions of ornamented character strokes of different widths;

FIG. 15 is a view showing the positions on the pixel screen, of some of the intersections obtained for the letter "F" of FIG. 4;

FIG. 16 is a view indicating the x-axis coordinate values of the intersections of FIG. 15 corresponding to the x-axis pixel lines;

FIG. 17 is a view explaining the manner of preparing dot data according to the x-axis coordinate values of the intersections as indicated in FIG. 16;

FIG. 18 is a view of letter "F" of 12-point size which is printed according to dot data which is prepared from the corresponding outline data, by a conventional data converting apparatus;

FIG. 19 is a view corresponding to FIG. 18, showing letter "F" printed according to dot data prepared from the corresponding outline data, by the present data converting apparatus of FIGS. 1-17;

FIG. 20 is a schematic view corresponding to FIG. 1, showing a control circuit of a laser printer incorporating a second embodiment of the data converting apparatus of the invention;

FIG. 21 is a view showing the central processing unit of the control circuit of FIG. 20;

FIG. 22 is a view corresponding to that of FIG. 4, showing the letter whose outline data is processed by the data converting apparatus of the second embodiment;

FIG. 23 is a pixel screen used in the second embodiment;

FIG. 24 is a flow chart showing an outline data processing routine executed in the data converting apparatus of the second embodiment;

FIG. 25 is an illustration showing a part of character outline data which has been changed according to the flow chart of FIG. 24;

FIG. 26 is a view showing letter "H" printed by a known laser printer;

FIG. 27 is a view showing letter "H" printed by the laser printer incorporating the data converting apparatus according to the second embodiment; and

FIGS. 28 through 30 are views corresponding to that of FIG. 25, showing further embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIGS. 1 and 2, there is shown a data converting apparatus constructed according to one embodiment of this invention, for converting outline data into dot data for printing on a laser printer.

The schematic block diagram of FIG. 1 shows a portion of a control circuit of the laser printer, which relates to data conversion according to the principle of the present invention