JPH04194898A - Character data control system for character output device - Google Patents

Abstract

PURPOSE:To improve utilization efficiency of fontcash so as to obtain a high speed output by deleting an unnecessary character at process waiting time while continuously using a region for temporarily storing a character data by an outputting data form. CONSTITUTION:In the case of outputting a character, a font control part 14 checks whether a dot form data of that character is stored or not in a font cache 21 by using a cash controlling table 28 and a character control table region 23. The data, when it is stored, is transferred to a frame memory part 12. In the case of the data not stored, the control part 14 searches the concerned data from inside a font data region 18 by a proper name of that character further controls a dot character generation part 19 and creates a dot form data. A size of each segment of the cache 21 is undefined, and the next to the last segment is set to an empty region. Deletion of the dot form character is executed when the control part 14 judges the empty region small at process waiting time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a character data management system for a character output device used when outputting high-quality characters to a rask-type printing device or a rask-type display device.

[Prior Art] Conventionally, a character data management system for this type of character output device is known as described in Japanese Patent Laid-Open No. 1-115647. As shown in FIG.
lb, lc, 1. d.

. . , dot characters of the same type are stored in the same area, and the font management tables 3a and 3b in the cache control table 2 and management area 3.

3c, . . . to manage each character type, and when deleting dot characters in font cache 1, each area was deleted as a unit.

[Problems to be Solved by the Invention] In this type of character output device, in order to output characters at high speed, it is necessary to store as many dot-type characters as possible in the font cache. However, high-speed storage devices used as font caches are expensive and have a limited usable capacity. Therefore, it is required to use the capacity of the font cache as efficiently as possible to store as many dot-type characters as possible.

However, in the conventional character data management method mentioned above,
The font cache is divided into areas of a certain size, and dot-format characters of different character types are stored in different divided areas, so it is possible to determine whether each divided area is used or unused free space. There was a problem with the overall font cache usage efficiency.

Therefore, the present invention makes it possible to improve utilization efficiency by continuously using the area of a storage means for temporarily storing character data in an output data format, and as a result, high-quality characters can be output faster. This paper aims to provide a character data management method for character output devices that enables the use of character output devices.

Furthermore, the present invention provides a character output device that erases unnecessary characters during the processing waiting time when character data is not created, thereby reducing the time required to erase characters during processing. It attempts to provide a character data management method.

[Means and operations for solving the problem] The invention corresponding to claim (1) is a holding means for holding geometric data of characters, and a conversion for converting geometric data of characters into a data format for output. In a character output device including a storage means for temporarily storing character data in an output data format, and an output means for outputting character data in an output data format, the character data is retained in the retention means when outputting characters. Obtain character data converted into a data format for output by a conversion means based on the geometric data of the character being displayed, output the character data by the output means, and convert the character data to a storage means into a character type. If the same character is to be output again by storing it in a continuous area regardless of the character, the character data of that character is read from the storage means and outputted to the output means, and when the character data is deleted from the storage means, the character data of the selected character is The purpose is to erase all the corresponding character data.

The invention corresponding to claim (2) is, in the character data management method described in claim (1), new character data in the output data format generated by character output is stored in the free space of the storage means generated by character data deletion. 2 and 1 to remember
There it is.

The invention corresponding to claim (3) is a holding means for holding geometric data of characters, a conversion means for converting geometric data of characters into a data format for output, and a data format for outputting character data. In a character output device equipped with a storage means for temporarily storing character data and an output means for outputting character data in an output data format, when outputting characters, the character data is output based on the geometric data of the character held in the storage means. obtain character data converted into a data format for output by the conversion means, output the character data by the output means, and store the character data in a continuous area in the storage means regardless of the character type. When outputting a character again, the character data of that character is read from the storage means and outputted to the output means, and when character data is deleted from the storage means, all character data corresponding to the selected character type is deleted and deleted. The goal is to fill up the free space created by this process and increase the free space that was available up to that point.

The invention corresponding to claim (4) is, in the character data management method described in claim (1), (2) or (3), furthermore, the invention corresponds to An order relationship is defined between each character type based on the length of time from when it was first used to the present, and when character data is deleted from the storage means, the character type that has not been used for the longest time is selected based on this order relationship. The purpose is to erase from character data.

The invention corresponding to claim (5) is claimed (1) and (2).
In the character data management method described in (3) or (4), character data is deleted from the storage means during the processing waiting time during which character data is not created when the free space of the storage means becomes smaller than a preset size. The goal is to do the following.

The invention corresponding to claim (6) includes claims (1), (2), (
3).

In the character data management method described in (4) or (5),
The conversion means secures an area in the storage means to be used when converting the geometric data of the character into a data format for output, and the conversion means uses this area to convert the geometric data of the character into the data format for output. The purpose is to create character data in data format.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In this embodiment, the present invention is applied to a character output device of a printer.

In FIG. 1, 11 is a central processing unit that controls the entire printer, 12 is a frame storage unit that holds bitmap data for one page to be printed, and 13 is a printout based on the data stored in this frame storage unit 12. 14 is a font control section that performs control related to character output; and 15 is a communication control section that performs communication control with the host computer.

The central processing unit 11, frame storage section 12, font control section 14, and communication control section 15- are electrically connected via a path line 16.

Reference numeral 17 denotes a font registration table, in which all fonts used by the printer are registered. 18 is a font data area that stores font data built into the printer, and this font data area 1
The font data No. 8 is in the form of a stroke font or an outline font. Reference numeral 19 denotes a dot character generation section that creates dot-format characters based on the contents of the font data in the font data area 18. Reference numeral 20 denotes a working memo 11 used by this dot character generating section 19 when creating dot format characters.

The font registration table 17, dot character generation section] 9
is controlled by the font control section 14.

Reference numeral 21 denotes a font cache as a storage means for storing dot format characters. 22 is a segment link area, and 23 is a character management table area.

The font cache 21, segment link area 2
2. The character management table area 23 is dynamically allocated in the cache memory so that it occupies a necessary size area at each point in time. These are controlled by the font control section 14.

Segment link structures 22a, 22b, 122C1, . . . are formed in the segment link area 22 as necessary.

These segment link structures 22a, 22b.

22C2... holds four pointers pz pb+ p, , pd, as shown in FIG. 2, where pointer p is a pointer to the beginning of the corresponding segment in the font cache 21;

is a pointer to the segment link structure of the immediately previous segment, pointer po is a pointer to the segment link structure of the immediately following segment, and pointer p is a pointer to the segment link structure of the next segment that belongs to the same character management table. is a pointer.

In the character management table area 23, character management tables 23a, 23b, etc. are formed as necessary. The second character management table exists corresponding to each dot font type in the cache management table, which will be described later.

These character management tables 23a, 23b, are the third
As shown in the figure, it is composed of a part 23□ that holds attribute information and management information of the corresponding dot font type, and a part 23□ that stores pointers and offsets to segment link structures in the order of character codes. . If the dot format data corresponding to the character code is not stored in the font cache 21, the pointer to the segment link structure is set to a special value rnilJ. The management information includes a pointer p0 to the first segment link structure, a pointer p3 to the last segment link structure, and a pointer q to the segment link structure of the first reused segment, which correspond to the character management table. is stored. X l + X2.

X3 indicates a pointer to the corresponding segment link structure.

24 is a free segment pointer, 25 is a reused segment pointer, 26 is a free area pointer, and 27 is a final segment pointer.

28 is a cache management table, 2 are oldest font pointers, and 30 are current font pointers.

The cache management table 28 and each pointer 24~
27, 29, and 30 are controlled by the font control section 14.

As shown in FIG. 4, the cache management table 28 has one item for each dot font type to which the dot format characters stored in the font cache 21 belong, and the corresponding character management table A pointer t to the previous font, a pointer V to the predecessor font, a pointer U to the successor font, and a value representing the dot font type are stored. Note that for a certain dot font type, the dot font type of the character used immediately after the last use of that dot font type is defined as the successor font, and for a certain dot font type, the dot font type of the character used immediately after the last time it was used is defined as the successor font. The dot font type of the character of the font type or the character used immediately before the last time it was used is defined as the predecessor font.

By using this predecessor font pointer and successor font pointer, an LRU (least-reason-nearest) bidirectional link can be realized.

When printing is performed based on instructions from the host computer, the communication control section 15 receives a series of instructions from the host computer. As a result, the central processing unit 11 causes the frame storage unit 12 to store bitmap data such as figures to be printed in accordance with the instruction, or, if there is an instruction to output a character, the unique name of the font of the character to be output. , the size, italic angle, rotation angle, and aspect ratio are determined, and the dot format data of the character is requested from the font control section 14.

As a result, the font control unit 14 uses the cache management table 28 and the character management tables 23a, 23b, . Find out whether or not. If stored, the cache management table 28 and character management table 23
a, 23b.

..., segment link structures 22a, 22b.

22C1... is used to obtain the address of the dot-format character in the font cache 21, and the frame storage unit 2
The corresponding dot-format character is transferred using that address.

Further, if the dot format data of the corresponding character is not stored in the font cache 21, the font control unit 14 searches the font data area 18 for the corresponding font data using the unique name of the font of the character. , further controls the dot character generation section 19 to create dot format data for the character by referring to the character size, italic angle, rotation angle, and aspect ratio. Then, the dot format data is stored in the font cache 21 and transferred to the frame storage section 12.

When all the characters to be printed have been transferred to the frame storage section 12, the central processing unit 1 instructs the print control section 13 to print out the data in the frame storage section 12.

The stroke font and outline font of the font data stored in the font data area 18 are registered in the font registration table 17 from the beginning.

The dot character generation section 19 is connected to the font control section 14.
Create dot format characters from font data in outline font or stroke font format under the control of .

The font cache 21 holds created dot-format characters. When a character is stored in this font cache 21, information such as the width and height of the character is also stored in addition to the dot data.

The inside of the font cache 21 is logically divided into a plurality of segments, or the size of each segment is undefined. After the last segment is an empty area where no data is stored.

Each segment stores dot-format characters of the same type of dot font. Note that dot font type is used to classify dot format characters.
1 in outline font or stroke font format
Dot-format characters created from two font data with the same size, italic angle, rotation angle, and aspect ratio belong to the same dot font type.

The dot format characters stored in the font cache 21 are managed for each dot font type.

For example, in the case of FIG. 5, first to sixth, . . . , final segments are formed in the font cache 21, and the area following the final segment is an empty area.

Since the first, third, and fifth segments belong to the same character management table, the segment link structure 22a
22b and 220 are linked by pointer p6, and the beginning of the first segment is indicated by pointer pa of segment link structure 22B. Also, since the second and fourth segments belong to different same character management tables, the segment link structures 22d and 22e are linked using the pointer pd, and the second segment is linked using the pointer pa of the segment link structure 22d. The beginning of the text is indicated. Further, the beginning of the sixth segment is specified by the segment link structure 22f. Furthermore, the segment link structure 22
g indicates the beginning of the final segment.

Further, the free area pointer 26 indicates the beginning of the free area, and the final segment pointer 27 indicates the segment link structure 22g corresponding to the final segment.

If we consider the case where a certain character of a certain dot font type is to be output, the font control unit 14 checks whether a certain dot font type exists in the cache management table 28.

If it does not exist, it is determined that the dot format data of a certain character is not stored in the font cache 2].

If a certain dot font type exists in the cache management table 28, the corresponding character management table is referred to using the pointer t, and the character code of the certain character is used to select the dot format data of the certain character or the segment in which it is stored. Examine the pointer to the segment link structure.

If it is a pointer or the special value rn i l J, it is determined that the dot format data of a certain character is not stored in the font cache 21. If the pointer does not have the special value rnilJ, it is determined that the dot format data of a certain character is stored in the font cache 21, and the segment link structure is referenced using the pointer.

and the referenced segment link structure pointer p,
, and the corresponding offset value of the corresponding character management table to obtain the address where the dot format data of the specified character is stored.

As a result, the central processing unit 1 transfers the dot format data at the corresponding address to the frame storage section 12.

If the dot format data of the character to be output is not stored in the font cache 21, the font control unit]
4 is a dot character generation unit] 9 is used to create a new dot format character and stored in the font cache 2]. The second storing procedure differs depending on whether or not a dot-format character of the same dot font type as a certain character has already been stored in the font cache 21.

First, let's talk about a case where a dot-format character of the same dot font type is already stored in the font cache 21. In this case, that dot font type already exists in the cache management table 28, so the corresponding character is You can refer to the character management table. The pointer to the segment link structure corresponding to the character code of a certain character in the corresponding character management table has a special value rnilJ. Then, the segment in which the new dot-format character is to be stored is determined. The pointer p1 to the last applicable segment link structure in the applicable character management table is compared with the final segment pointer 27. If they are the same, the final segment stores characters of the same dot font type, so when creating a new segment, store the new dot format characters in the free space following the final segment, and extend the final segment to the used area. shall be. If the final segment corresponding to the relevant character management table is different from the final segment in the font cache 21, a new segment is provided for the dot font type of the relevant character management table.

That is, a new segment link structure is prepared and the contents of the free area pointer 26 are transferred to pointer p.

, the pointer p points to the segment link structure of the final segment up to now, and the special value ``n1lJ'' is assigned to the pointer pc and pointer p.

Subsequently, the address of the new segment link structure is assigned to the pointer p of the segment link structure indicated by the pointer p1 of the corresponding character management table, and the address is also assigned to the pointer p1. The address is also assigned to the final segment pointer 27.

In this way, the beginning of the previously free area becomes the beginning of the new segment. A dot-like character will be created and stored in this new segment.

In addition, a pointer to the corresponding segment link structure and an offset from the beginning of the segment to the data position of the character are written in the part of the character management table corresponding to the character code of the character.

Next, a case will be described in which a character of the same dot font type as a dot-format character to be stored is not stored in the font cache 21.

In this case, the corresponding dot font type does not exist in the cache management table 28. Therefore, an item for the corresponding dot font type is prepared in the cache management table 28. Then, a new character management table is prepared in the character management table area 23, and the address of the corresponding character management table is written as a pointer t to the character management table of the corresponding item in the cache management table 28.

Thereafter, a new segment is provided to store the dot-form characters in the same way as in the case where all the dot-form characters of the same dot font type are already stored in the font cache 21.

By storing dot format characters in the font cache 21 as described above, characters of the same dot font type will exist in multiple segments, but the character management table contains information about each character in the segment link structure. Since it holds a pointer, there is no problem when referencing it.

When printing regular text, characters of the same dot font type are often consecutive, and each segment is not very detailed.

The reason why a segment link structure is used when referencing a segment is to facilitate and speed up processing in the case of deletion and movement, which will be described later.

When creating dot-format characters using the dot character generator 19, you can secure an area to store them in the font cache 21 before creating them, and use that area as a temporary work area to directly access the font cache 21. It is possible to create dot-form characters on the top of the screen, making the working memory 20 unnecessary.

In other words, the memory capacity required for processing can be saved.

It also saves time in transferring Tosoto format data.

Next, the case of deleting dot-format characters stored in font cache 2 will be described.

If the free space in Font Cache 2 becomes insufficient and it is no longer possible to store new dot-format characters, deletion is performed. In other words, during the processing wait time when dot-format characters are not created, the size of the free space in the font control unit]4 or the predetermined value and the font cache2] are compared, and if the free space is determined to be small, deletion is executed. do.

This deletion is performed using a set of characters belonging to the same dot font type as one unit. Further, dot font types stored in the font cache 21 that have not been used for the longest time are deleted in order. That is, the item in the cache management table 28 indicated by the oldest font pointer 29 is always the item of the dot font type that has not been used for the longest period of time. A pointer p to the first corresponding segment link structure by referring to the corresponding character management table from this item. get.

The deletion procedure will be explained below based on FIG. 6.

(a) in Figure 6 shows the state before deletion, with pointer 1)
Assume that Ll points to, for example, the segment link structure 22□.

First, let's talk about the case where deletion is performed during processing waiting time.
As shown in FIG. 6(b), the pointer p.

After holding the value of , that is, the address of the segment link structure 222, the corresponding character management table is released, and the corresponding item in the cache management table 28 is deleted. The segment link structures 22 and 223 are referenced by the pointers p, , p of the segment link structure 222. Segment link structure 22. The address of the segment link structure 223 is assigned to the pointer p of the segment link structure 22., and the address of the segment link structure 22. Assign the address of . Then, the content of the segment indicated by pointer p of segment link structure 223 is copied and moved to the position indicated by pointer p of segment link structure 222. Then, the pointer p of the segment link structure 223 is changed to a new value.

As a result, the corresponding segment of the segment j link structure 222 disappears. and segment link structure 22
Segments corresponding to segment link structures 3 and onwards are sequentially copied and moved in the same manner. This movement is performed to the front of the segment link structure indicated by the pointer p6 of the segment link horizontal corpse 222.

Pointer p of segment link structure 22□.

Since the segment link structure indicated by is to be deleted, the corresponding segment is similarly deleted.

In this way, segment movement is repeated until the final segment. Finally, all unnecessary segment link structures are released.

If the deletion is performed as described above, the dot font type is selected and deleted, and the free areas of the font cache 21 are consolidated into one location, so dot format characters can be stored with high efficiency. Furthermore, when moving a segment, it is only necessary to copy and move the contents of the segment and then change the pointer p of the segment link structure, and this can be done without regard to the character management table, etc., so it can be done easily and quickly.

Next, we will discuss the deletion that is normally performed when a new dot-format character cannot be stored.

In this case, no segment movement is performed. (C
, ) as shown in the pointer p. The contents of are assigned to the free segment pointer 24. The corresponding character management table is opened and the corresponding item in the cache management table 28 is deleted. The segments indicated by the pointer p of the segment link structure 222 are segments that are no longer needed, and these are referred to as empty segments.

Pointer p to segment link structure of free segment
By chaining 6, a chain of free segments can be created. If further deletion is performed, the chain of empty segments is extended by connecting the segment link structure of the unnecessary segment.

Thus, there will be some free segments.

To store a new dot-format character in this state, check the size of the free segment beyond the free segment pointer 24, and if a free segment of sufficient size is found, store the new dot-format character in that segment.
A reusable segment is created as shown in FIG. 3(d).

The address of the corresponding segment link structure 22□ is assigned to the reusable segment pointer 25 and the pointer q of the corresponding character management table. Segment link structure 22
2 is removed from the chain of free segments.

The segment pointed to by the pointer pd of the segment link structure 22□ is a free segment, so it is connected to a chain of free segments (a pointer indicating how far that segment has been used is stored at the beginning of the reused segment. .

Characters belonging to the same character management table can be stored in the remaining area of the same reusable segment.

In this way, dot format characters are stored in free segments and reused segments.

When the processing wait time is reached, the empty segment is erased in the same manner as described in FIG. 6(b). You can also turn it into a regular segment by filling it with reusable segments.

To delete characters of the dot font type in the character management table that use reused segments, pointer p
. In addition to the segment pointed to by pointer q, the segment pointed to by pointer q is also subject to deletion.

When a dot-format character is stored in a reusable segment, the utilization efficiency of the font cache 21 decreases until processing is performed to convert it into a normal segment. In order to avoid this as much as possible, if the size of the free area falls below a certain value during the processing waiting time, delete the free area by filling it up to secure a certain size of free area.

Next, a method will be described in which the cache management table 28 maintains the order relationship of dot font types using LRL+bidirectional links and determines the dot font type number to be deleted.

The cache management table 28 maintains the order relationship based on the length of time from the last time each dot font type was used to the present, using a pointer U to the successor font and a pointer V to the predecessor font for each dot font type item. do.

The dot font type you are currently using is "Gothic A2".
0", and the order used before that is "Gothic BI
Assuming that they are OJ, "Gothic A10", and "Gothic B30", the cache management table 28 holds the order of 2 as shown in FIG. 7(a).

The current font pointer 30 indicates "Gothic A20" currently in use, and the two oldest font pointers indicate "Gothic B30" which has not been used for the longest time.

If the characters "Gothic A10" are used here, the seventh
As shown in (b) of the figure, the item "10 to Kosic" is removed from the chain of pointers U and V.

Next is "Gothic A20", which has not had a successor font until now.
The pointers u and v and the current font pointer 30 are set as shown in FIG. 7(C). In this way, the order relationship is maintained.

Also, when a new type of dot font is used, the state shown in FIG. 7(b) may be changed to the state shown in FIG. 7(C).

In the case of (C) in FIG. 7, the dot font type to be deleted is "Gothic B3" indicated by the oldest font pointer 29.
0". After deleting this, the result is (d) in Figure 7.
The oldest font pointer 29 now points to "Gothic B]0" as shown in FIG.

If you do the above, the chain of pointers U and V will always lead to L.
To maintain RU bidirectional links, it is possible to accurately search for the dot font type that has not been used for the longest period of time.

In addition, as a method of maintaining the order, a method may be considered in which a numerical value representing the order in which each Tosotophone/type is assigned is attached instead of using a chain of pointers. In this case, it may be necessary to examine all dot font types in order to check the relationship between numerical values. Therefore, the method using a chain of pointers is simpler and allows faster processing.

In the above embodiment, the case where characters are managed in dot format has been described, but it is needless to say that the present invention is not limited to this.

It should be noted that although the above-mentioned embodiments have been described in which the present invention is applied to a printer, the present invention is not necessarily limited to this, but can also be applied to, for example, a display device.

[Effects of the Invention] As detailed above, according to the present invention, utilization efficiency can be improved by continuously using the area of a storage means for temporarily storing character data in an output data format. As a result, it is possible to provide a character data management method for a character output device that can output high-quality characters at a higher speed.

In addition, by erasing unnecessary characters during the processing wait time when character data is not created, the time for erasing characters during processing is shortened, and in this respect as well, this is a character data management method for character output devices that enables faster output. It is possible to provide

[Brief explanation of the drawing]

1 to 7 show an embodiment of the present invention. FIG. 1 is a block diagram, FIG. 2 is a diagram showing the configuration of a segment link structure, and FIG. 3 is a diagram showing the configuration of a character management table. 4 is a diagram showing the configuration of the cache management table,
Figure 5 is a diagram to explain segment management of font cache, Figure 6 is a diagram to explain segment deletion of font cache, Figure 7 is a diagram to explain management by cache management table, Figure 6 is a diagram to explain segment deletion of font cache, FIG. 8 is a diagram for explaining conventional character data management. 14... Font control section, 18... Font data area, 1... Dot character generation section, 2 font cache, 22... Segment link chain acid, 23... Character management table area. Applicant's representative Patent attorney Takehiko Suzue No. 31/1 No. 51:5 (a) (c) No. 6 (b) (d): (a) (c) No. (b) (d)

Claims (6)

[Claims] (1) A holding means for holding the geometric data of characters, a conversion means for converting the geometric data of characters into a data format for output, and a memory for temporarily storing character data in a data format for output. and an output means for outputting character data in an output data format, wherein when outputting characters, the converting means outputs characters based on the geometric data of the character held in the holding means. Obtain character data converted into a data format for When the character data is to be outputted, the character data of the character is read from the storage means and outputted to the output means, and when the character data is deleted from the storage means, all character data corresponding to the selected character type is deleted. Character data management method for character output devices. (2) In the character data management method of the character output device according to claim (1), new character data in the output data format generated by character output is stored in the free space of the storage means generated by character data deletion. A character data management method for a character output device characterized by: (3) A holding means for holding the geometric data of characters, a conversion means for converting the geometric data of characters into a data format for output, and a memory for temporarily storing character data in a data format for output. and an output means for outputting character data in an output data format, wherein when outputting characters, the converting means outputs characters based on the geometric data of the character held in the holding means. Obtain character data converted into a data format for When outputting the character data, the character data of the character is read from the storage means and outputted to the output means, and when the character data is deleted from the storage means, all the character data corresponding to the selected character type is deleted and deleted. A character data management method for a character output device, which is characterized in that the free space generated by the process is filled up to increase the free space up to that point. (4) In the character data management method of the character output device according to claim (1), (2) or (3), when the character data is last used for the character type of the character data stored in the storage means. An order relationship is defined between each character type based on the length of time from then to the present, and when character data is deleted from the storage means, character data corresponding to the character type that has not been used for the longest time is defined based on this order relationship. A character data management method for a character output device characterized by erasing data from a character output device. (5) In the character data management method of the character output device according to claim (1), (2), (3) or (4), when the size of the free space of the storage means becomes less than or equal to a preset size, the A character data management method for a character output device, characterized in that character data is deleted from the storage means during a processing waiting time when data is not created. (6) Claims (1), (2), (3), (4) or (5)
) In the character data management method of the character output device described in
The conversion means secures an area in the storage means to be used when converting the geometric data of the character into a data format for output, and the conversion means uses this area to output data based on the geometric data of the character. A character data management method for a character output device, which is characterized in that character data is created in a standard data format.