JP2001113764A - Printer and image processing system equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the shortening of a transmission time and the enhancement of processing efficiency and speed by employing a printing control system minimizing the data quantity of a printing command, and enabling the enhancement of the printing and drawing processing of a character. SOLUTION: A printer control part 103 performs the definition of a font, the selection or elimination of a font used in drawing and the processing to a character cash control list 104 according to the printing command sent from a printer driver 201 in the data form corresponding to the font kind and use frequency of the character in a printing document and the presence of font data used in drawing and performs processing according to the use of the device font on a printer side/the down-load font on a host side, the presence of font cell data, the presence of cash registration data and the indication of compressed/uncompressed data at a time of drawing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printer device, and more particularly, to efficiently draw characters and character strings by print command data transmitted from a host computer such as a personal computer while minimizing the data amount. The present invention relates to a printer having print control means and an image processing system including the printer as a component (including a digital copying machine having a printer function and an image data output device such as a facsimile).

[0002]

2. Description of the Related Art Conventionally, fonts have been used to print a document including characters. As a method of using fonts, a method using a device font stored in a font ROM or an optional cartridge in a printer device and a method using a host computer There is a method using a download font on the computer side. When using the device font on the printer device side, the host computer only needs to send the character data included in the print command as code data, so that less transfer data is required. However, if the character to be printed is an outline font, the printer needs to develop the bitmap data. Also, when using font data on the host computer side, the host computer side rasterizes the fonts and develops the bitmap data and sends it to the printer. More.

Therefore, bitmap data is compressed in order to reduce the transfer amount, or a cache process is performed in advance on the host computer side, and characters having a high appearance frequency (usage degree) are collected and transmitted to the printer side. In order to reduce the time required for reading from the font ROM and developing the data on the printer side, the developed font data is stored in the font cache memory. As an example of such a conventional system, a printer system intended to realize high-speed processing by changing the form of transmission data to a printer in consideration of the capabilities of a host computer and a printer has been proposed. Since the processing speed is affected by the amount of available memory, memory is saved to achieve high-speed processing. As one example, a method of creating character data by a banding method which saves memory by performing drawing in units of a plurality of bands is known. By caching,
The processing load at the time of band expansion is reduced, and the band memory expansion processing time can be shortened.

[0004]

With respect to the processing load on the printer device side, since the processing capability of the host computer has been improved in recent years, processing such as font rasterization conventionally performed by the printer has been performed by the host computer. But now that it can be done, it is in the direction of being reduced. However, since the conventional print control system has a print command system that assumes the capabilities of the conventional host computer, there is a load on the printer that should be reduced. On the other hand, as the resolution of the printer has been improved and the need for printing on larger paper has been increased, more and more memory areas have been required. For this reason, it is desired to efficiently use data registered in the cache. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems in the related art, and has as its object to minimize the data amount of print command data transmitted to a printer device and to perform printing of characters and character strings and drawing processing. A printer device capable of shortening transfer time and increasing processing efficiency by adopting a print control method capable of increasing efficiency, and thereby speeding up printing processing, and an image processing system including the printer device as a component (Including an image data output device such as a digital copying machine or a facsimile having a printer function).

[0005]

According to a first aspect of the present invention, there is provided a printer which takes a data form corresponding to the type and use of font data used for printing characters included in a document to be printed and the storage location of the font data. In a printer having printer control means for generating character drawing data according to a print command sent from a driver, the printer control means defines and selects a font used for drawing characters included in a document to be printed according to the print command. ,
The operation of deleting, the operation of registering the character data of the font selected for drawing in the character cache according to the font typeface and the drawing command to be used, and the operation of deleting the registered cache data when it is no longer needed An operation of deleting all or a specified part of cache data is performed.

According to a second aspect of the present invention, in the printer device according to the first aspect, when registering character data in a character cache, a font selected for use in drawing is a device font or a printer driver. If it is a downloaded font that has already been rasterized, or if it is a download font, whether it is uncompressed or compressed data, whether it contains font cell information, or uncompressed character data rasterized as cache data, Information indicating which data is to be stored as compressed data is notified by a print command, character data including code data is registered in the character cache in a data format according to the information, and the character data registered in the character cache is deleted To delete all registered data, or specified characters Information for instructing to delete data over de is notified by the print command, and is characterized in that for deleting in accordance with that information.

According to a third aspect of the present invention, in the printer device according to the first or second aspect, a font used when generating drawing data of a character or a character string for a font selected for use in drawing. Is a device font, a download font, and whether or not there is font cell information.If there is no font cell information, the drawing start point is used. Information indicating whether to use the data registered in the character cache, whether the data to be used is uncompressed or compressed data, and whether the drawing position is based on relative coordinates or absolute coordinates. It is notified by a print command, and performs drawing data generation processing in accordance with the information.

According to a fourth aspect of the present invention, in the printer device according to any one of the first to third aspects, the printer control means, when the memory used for the character cache or the drawing of the character becomes insufficient, the printer device. Releasing the memory that stores the device font bitmap image or its compressed data that has been rasterized and registered in the character cache until a memory of the required size is obtained,
Using the free space, registration in the character cache or character drawing processing is continued.

According to a fifth aspect of the present invention, in the printer device according to the fourth aspect, the release of the memory is performed by using a font developed over a plurality of bands when band processing is used to generate drawing data. Except for those for which rendering has not been completed, the font is used in order from the font used most recently.

According to a sixth aspect of the present invention, in the printer device according to the fourth or fifth aspect, even if all the bitmap image data of the device font generated on the printer device side or the compressed data thereof are deleted, a necessary free area is provided. Is not obtained, the bitmap image data of the download font registered in the character cache is compressed without being compressed.

According to a seventh aspect of the present invention, in the printer according to the first aspect, registration and deletion commands in a character cache included in the print command are issued only for characters to be rasterized by a printer driver. For a device font to be rasterized, only a drawing command is issued.

According to an eighth aspect of the present invention, in the printer device according to the seventh aspect, when the received print command includes a device font drawing command in the received print command, the printer control means converts the character data of the device font to the printer command. It is characterized in that it is determined whether or not registration is possible in the character cache, and if registration is possible, drawing is performed after registration.

According to a ninth aspect of the present invention, in the printer device according to the seventh or eighth aspect, when the memory used for the character cache or the drawing of characters is insufficient, the printer control means performs rasterization on the printer device side. The memory storing the character data and the character image data of the device font registered in the character cache or the compressed data thereof is released until a memory of a required size is obtained. It is characterized in that registration or character drawing processing is continued.

According to a tenth aspect of the present invention, there is provided an image processing system comprising the printer device according to any one of the first to ninth aspects as a system element.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described based on the following embodiments shown in the accompanying drawings. FIG. 1 shows a block diagram of a main part of an embodiment of a system according to the present invention. This system is configured by connecting a host computer (not shown) and the printer device 100 via a communication path. The host computer includes a document creation application that runs on the OS to create a document or the like to be subjected to print processing in the printer device 100 to be used, and a printer driver 201 that creates print data from data of the created document or the like. The printer driver 201 receives settings such as printing conditions by the user based on the document data, and
Then, print data expressed in a printer language suitable for 00 or a digitized image is generated and sent to the printer device 100 through a communication control unit (not shown). The printer device 100 that receives print data sent from the host computer through the interface unit 101 includes a command analysis unit 102 and a printer control unit 103. The printer control unit 103 controls access to the character cache memory 107 via the character cache management list 104 according to the print command analyzed by the command analysis unit 102, and controls the font cache memory 11 via the font cache management list 111.
2 and controls a rasterizer 105 that performs a rasterizing process based on data from a font ROM or a cartridge 106 or transferred data, and also controls a rasterizer 105 based on data from a font cache memory 107 or transferred data. It controls a development module 108 that performs a development process on drawing data, and further controls access to the frame memory 109 to develop the drawing data on a memory. The printing unit 110 performs printing output based on the drawing data developed on the frame memory 109.

In the present invention, in a system in which device fonts to be rasterized on the printer device 100 side and download fonts to be rasterized on the host computer side are mixed, the amount of transfer data is minimized by the printer driver 201 on the host computer. Then, print command data capable of increasing the efficiency of drawing characters and character strings is determined and transferred to the printer device 100. The printer 100 executes a series of printing processes including a cache operation for both the device font and the download font in accordance with the transferred print command data. FIG. 3 is a flowchart showing one embodiment of a series of print processing operations of the printer apparatus of the present invention operated by such print command data. The print processing operation will be described with reference to the flowchart of FIG. First, on the host computer side, the typeface, size,
A printer driver 201 that can obtain the appearance frequency of a character (the degree of use of each font data used for printing) and the storage location of the font data to be used based on the character code.
Thus, a print command considered to be optimal is created in consideration of the preset communication path and the performance and restrictions of the printer device 100, and the created print command is connected via the communication path. Printer device 100
Is forwarded to

In the printer device 100, the command analysis unit 102 reads the data of the print command sent via the interface unit 101 (S301), analyzes the read print command, and performs processing according to the print command. Commands related to characters include commands related to definition and selection of fonts, cache operations on fonts and character data, and drawing processing of characters and character strings. As a procedure, it is checked whether or not the command is a character-related command (S302). If the command is not a character-related command, data is sent to another command process (S303).
Here, only the processing of the character-related command will be described below.

At the beginning of the processing of the character-related command, it is checked whether or not to define a font (S304). When the definition is to be performed, the specified font definition is set as the current font of the printer control unit 103. (S30
5). Fonts are defined by the number of fonts having different attributes included in the print document, and are managed by font IDs. Processing such as selection, deletion, and all deletion of the font used for drawing is performed on the font ID. When defining fonts, fonts such as font type (device font or download font), feed direction (vertical font or horizontal font), rotation direction, style (bold, italic, bold italic) Information and a font ID uniquely assigned to each font are used as data. Here, in the case of a device font, the device font ID uniquely determined for the font name existing in the installed font ROM (or cartridge) 106 and the width and height of the font cell (see FIG. 2) are used. Added as data.

As the next procedure, it is checked whether or not to control the font (S306). When the font is to be controlled, the font to be used for drawing is selected by specifying the font ID, or the deletion of the current font is specified. Check if there is any (S307) and select the specified font ID.
The current font is updated (S308). In addition, it is checked whether the deletion of the current font is specified to delete all or the specified font (S309). If the deletion is specified, the font definition list is initialized (S310). If the specified font is to be deleted, only that font is deleted from the definition list (S311).

Next, it is checked whether or not to control the character (S312).
Control the character cache. The printer control unit 103 in the printer device performs registration and deletion processing on the character cache management list 104 according to the print command. The character cache management list 104 includes data according to an operation in addition to information such as a font type, a data compression method, a font ID, the presence or absence of cell information, and a cache data holding format. The specified font ID
When all characters are deleted, other data (data corresponding to the operation) is not transferred, but when a character is registered (S313), frequently used character data (character code, offset information, etc.) is drawn. The characters are transferred together in a format that matches the scheduled command. When deleting the character with the specified font ID, the character codes to be deleted are transferred together. As a procedure, it is checked whether the character of the designated font ID is registered or deleted in the character cache management list 104 (S313), and based on the result, registration is performed (S314) or deleted. When deleting, specify whether to delete all or the specified font.
It is checked whether the character of the ID is to be deleted (S315), and in the case of all deletion, the character cache management list 104 is initialized (S315).
316). In the case of deleting the character of the specified font ID, only the font is stored in the character cache management list 104.
(Step S317).

After the definition of the font, the selection and deletion of the font used for drawing, and the processing for the character cache management list 104 as described above, the character or character string is drawn for the selected font (S31).
8). At the time of drawing processing, from the host computer side,
Whether the font to be used is a device font or download font, whether there is font cell information, whether to use data registered in the cache, and whether to use compressed or uncompressed data Information on whether the drawing position is based on relative coordinates or absolute coordinates, and minimum data for drawing a character or a character string based on the information are sent.

FIG. 4 is a flowchart showing one embodiment of such a character or character string drawing processing operation. The drawing processing operation will be described with reference to the flowchart of FIG. First, it is determined whether it is a character or a character string (S401). If it is a character, a drawing process procedure (a procedure shown as drawing a character in the figure) is executed. In the procedure of the character drawing processing, first, it is checked whether the data is registered in the cache (S402). If the data is registered, the font cache management list 104 is referred to (S409). The bitmap data is expanded on the frame memory 109 and rendered based on the data (S408), but the expansion processing is performed depending on whether or not the referenced data is compressed data (S411). The expansion processing is performed by the module 108 (S412). If the data is not registered in the cache, it is checked whether the data is a download font (S403). If the data is a download font, the bitmap data is determined based on the transferred data in the same manner as in normal drawing processing. Is developed on the frame memory 109 to perform drawing (S408).
Depending on whether or not the data is compressed (S40
4) In the same manner as described above, expansion processing involving decompression processing is performed (S
405). Also, the drawing start position is changed depending on the presence or absence of the cell information. When there is no cell information, the drawing start point is used. When there is the cell information, the character or character string is drawn using the arrangement reference point ( S406).

If the device font is directly specified in step S403, it is checked whether or not there is cell information (S413). If not, the cell information is set (S41).
4), the rasterizer 105 performs a rasterizing process according to the cell information (S415). After that, the bitmap data is developed on the frame memory 109 to perform drawing (S
408). The cell information used in steps S406 and S414 is used as feed information when arranging characters as shown in an example of a cell configuration in FIG. This is necessary when drawing a proportional font in which cells are variable depending on characters in the font.
However, when drawing with only one character or when drawing a font with a fixed pitch as a character string, it is possible to draw without using cell information. In the cell information, since two values of the cell width and height are set for each character, it is not transferred as data when it is not necessary to use it.

In the case of the character string drawing processing, the drawing information and the number of characters constituting the character string are read (S41).
6) After that, the procedure of the drawing process (the procedure shown as drawing a character in the figure) is executed for each character (S417),
The number of characters for which the drawing has been completed is counted (S418), and the drawing processing procedure for the number of characters constituting the character string is repeated. When the drawing of all the characters is completed (S419), the process returns to the initial state of the print processing operation (FIG. 3).

In the present invention, when the memory to be used in the character cache memory 107 cannot be secured sufficiently, an operation is performed such that a part of the memory is released and the cache memory is effectively used. I do. In the present embodiment, the printer control unit 103 performs this operation. The printer control unit 103 releases the memory storing the bitmap image of the device font or the compressed data thereof which is rasterized by the printer device 100 and registered in the character cache memory 107, and is necessary for the continuation of the processing. Since a free area is created, processing can be continued even when a buffer memory used for drawing a font cache or characters is insufficient. At this time, the data released on the printer side is the memory storing the bitmap image of the device font or the compressed data which can be recreated when the memory has room. However, when performing band processing, device fonts that are expanded over multiple bands and that have not been rendered are likely to be referenced even if they are the most recently used. , Except for such fonts, remove them from the cache in the order that they were used most recently. Furthermore, even if the memory area is released by compressing the bitmap image data of the download font registered in the cache in an uncompressed state, even if all the bitmap image data of the device font generated on the printer side is deleted. Even when a necessary free area cannot be obtained, the processing can be continued.

In order to perform the above-described operation of releasing the memory area, as a procedure in the flow shown in FIG. 4, when the characters of the device font are used, the list linked in the use status is updated (S410). In the case where band processing is performed, a flag indicating information is set for a device font developed over a plurality of bands and determined to be developed on the next band. If the memory cannot be secured during the drawing processing operation in the above procedure, the data registered in the character cache management list 107 is stored in the bitmap image or compressed data of the device font. The memory storing the data is released until a memory of a required size is obtained. However, it is assumed that a flag with the flag set in the band processing is not deleted.

In the above memory release processing, if the required memory size cannot be secured, the character data registered in the uncompressed state among the character data registered in the character cache management list as the download font. , And compresses the bitmap image data by an arbitrary compression method implemented in the printer control device, and updates the data information in the character cache management list 104. Also in this case, as a procedure in the flow shown in FIG. 4, when bitmap image data is used, the list linked in the use status is updated (S407). In the case where band processing is performed, a flag indicating the information is set for a band determined to be developed over a plurality of bands.

FIG. 5 is a flowchart showing one embodiment of the memory release processing operation. The drawing processing operation will be described with reference to the flowchart of FIG. Printer control unit 103
First, the font cache management list 111 refers to the device font use list registered in the font cache memory 112 (S501). here,
The information of the data is referred to in the order of the earliest use of the use list (S503), and it is checked whether or not the band processing flag is set in the information of each device font (S504). Release the memory area used by the device font (S50
5). As a result, it is checked whether or not a necessary free area is created (S506). If the space is created, this processing is terminated. If not, the next unreferenced data in the next order in the list is further released in the same procedure as the first. Perform processing.

If this procedure is repeated for all of the device fonts registered in the list and the necessary free area is not created, the character cache management list 104
Refers to a font other than the device font (S50).
7) Check non-compressed data, that is, font data using bitmap image data, with the downloaded font (S509), and if the corresponding font data exists, perform data compression on the font data (S510) and use it. Free up the memory area of the reduced amount. Thereafter, in the character cache management list 104, the data is updated with respect to the font data to be subjected to the data compression processing (S511). It is checked whether the required free area is created by releasing the memory area (S
512) If this is completed, the process is terminated. If the process is not completed, data compression and release processing is further performed on the next unreferenced data in the list in the same procedure as the first, until no unreferenced data is left. Is repeated (S508).

As described above, according to the present invention, the memory in which the bitmap image of the device font registered in the font cache memory 112 or the compressed data thereof is stored is released, or the memory is stored in the cache in an uncompressed state. The memory area is released by compressing the bitmap image data of the downloaded font that has been created, creating an empty area necessary for continuing processing, and performing operations that make effective use of the cache memory. . However, in such an operation, the host computer must also be aware of the memory size that should be used for the device fonts that are to be rasterized on the printer side. In such a case, it is difficult for the host computer to determine the size. Also, even if the data is registered in the cache, if it is device font character data, if the memory is insufficient, the image data part will be deleted.
When the drawing request by the character code is received, there is a disadvantage that the rasterizing process, which requires more time, is performed again from the character information data for drawing in the character cache.

In order to solve this inconvenience, in the present invention, when only the device font is used, a procedure for simplifying the processing is prepared without performing the character cache operation on the host computer side. In the present embodiment, the printer control unit 103 performs this operation. In this operation, the condition that the device font characters can be cached is only when the drawing command is transmitted to the printer control unit 103 and when the device font can be registered in the character cache. Further, when the available memory area becomes insufficient, the printer apparatus 100 deletes the image data of the character of the device font registered in the cache and the character data used for the rasterization and continues the processing. In this case, a cache operation of device font characters is performed.

FIG. 3 is a flowchart showing one embodiment of a series of print processing operations of the printer apparatus of the present invention operated by the print command data. FIG. 6 is similar to FIG.
FIG. 13 is a flowchart showing an example of a character or character string drawing processing operation shown in step 318 of FIG. Although FIG. 3 is shown as relating to the previous embodiment, the basic flow of the print processing operation of the present embodiment is not different from that of the previous embodiment. The operation flow will be described based on FIG. However, here, since a series of printing processes up to processing of a command for drawing a character in a device font will be described, the control procedure of the character cache in steps S312 to S317 shown in FIG. This step is enabled when the download font is the current font.) Also, the processing flow of FIG. 6 is basically the same as the flow of the previous embodiment (FIG. 4).
The same steps are denoted by the same step symbols. Also, here, the drawing process using the device font will be described, so that steps S409 to S41 shown in FIG.
2 font cache control procedure and step S40
Procedures 4 to 406 relating to the download font are invalid (these steps are valid when the download font is the current font).

Prior to the execution of the flow of FIG. 3, on the host computer side, the printer driver 201 that generates a print command uses a font that must be rasterized on the host computer for characters included in the document to be printed. If it is a downloaded font that needs to be rasterized and determined,
The appearance frequency (usage) of the character is counted based on the font name, size, character code, decoration information, and the like of the character, and it is determined whether the character is to be registered in the cache. If the character is to be registered in the cache, the image data of the character is transmitted to the printer device 100 as a command for registering the cache. Otherwise, character data is transmitted as a normal drawing command.

In the printer device 100, the data of the print command sent via the interface unit 101 is read by the command analysis unit 102 (S301), and the print command created by the printer driver 201 is analyzed by the above-described method. Is performed according to. Commands for characters include defining and selecting fonts,
Examples include cache operations for fonts and character data, and processing for drawing characters and character strings. Less than,
A process according to a command required until a character of a device font is drawn will be described together with an operation of the printer control unit 103.

First, the processing of the font definition command (S304, S305) will be described. The data to be defined includes the font type (device font or download font) and the sending direction (vertical writing font or horizontal writing font). Font ID), rotation direction, and font ID uniquely assigned to manage such information. As for the device font, it also includes information indicating a font name and a modification style, and cell height information. Font data is in the font cache management list 1
11 and the font ID is used to operate the font cache table and select the current font used for drawing (S306 to 308). A character cache table used for character caching is created for each font. Therefore, deleting a font also means deleting all character data and character image data registered with the font. The font deletion processing is performed when a font deletion command is sent from the host computer or when the same font ID as the font ID already registered in the font cache table is used.
It is performed when ID data is transmitted (S309 to 311).

The font selection process is described below. When the above-described font definition command is transmitted (S306 to 308), the font selection process is performed for a font that is defined in advance and is different from the current font. Is performed by a font selection command issued before the character is drawn. The current font here refers to font data used for drawing. When a command for drawing a character or a character string is transmitted while the device font is selected as the current font, the command is registered in the character cache management list 104 as shown in the character drawing procedure of FIG. It is checked whether the data is present (S601), and if it is not registered, a process of expanding it into character data is performed. This process
It is checked whether or not there is cell information (S413). If there is no cell information, the cell information is set (S414), and a rasterizing process according to the cell information is performed (S415). Thereafter, it is checked whether or not registration is possible (S605). If registration is possible, rasterized data is registered (S606), and after that, it is developed on a frame memory and drawn (S408). If registration is not possible, rasterized character image data is downloaded onto a memory for drawing in the frame memory 109 and drawn in the same manner as in normal drawing processing (S
408). If the character cache management list 104 has already been registered, the character cache management list 104 is not newly rasterized.
(S602). Based on whether or not the referred data is compressed data (S603), decompression processing including decompression processing is performed (S60).
4) A character is downloaded to a memory for drawing characters and drawing processing is performed (S408).

As described above, according to the present invention, in the case of a character of a device font, information necessary for rasterization is always transmitted in a state included in a drawing command, and character image data can be registered in a character cache. After the rasterized image data is registered in the cache, the drawing process is performed. When registering in the cache, it is conceivable to perform compression in accordance with the installed compression method according to the available memory size. When the amount of memory that can be used by the printer control unit 103 is small, there may be a situation in which the memory becomes insufficient. In this case, however, the character image data and character data registered in the device font cache are used. Release the memory used and secure the amount of memory that can be used. The memory is released by using the font cache and the character cache. Since the release procedure itself is the same as that shown in the previous embodiment (see FIG. 5), the flowchart is omitted. The difference is that not only the character image data is deleted, but also the character information data for drawing that has been registered in the character cache in order to rasterize the character again later.

[0038]

(1) Effects corresponding to the first aspect of the invention Appearance frequency for each character type based on the typeface, size, and character code of the characters included in the document to be printed (the degree of use of each font data used for printing) ), A printer driver that can grasp the storage location of the font data to be used, etc., by taking into account the preset communication paths and the performance and restrictions of the printer device, and using the optimized print command created. It is possible to define the typeface used for drawing characters, select the typeface and register the character data of the selected typeface in the character cache, and delete specified or all registered cache data when it is no longer needed. As a result, the amount of data transferred can be reduced, the cache memory can be used efficiently, and processing in the printer device can be reduced. , It is possible to speed up the printing process. (2) Effect corresponding to the second aspect of the invention In addition to the effect of the above (1), since it is possible to change various data registered in the character cache with information specified by the print command, the drawing Only necessary and sufficient data corresponding to the character or character string to be used can be registered, and the character cache can be used effectively. (3) Effects corresponding to the third aspect of the invention In addition to the effects of the above (1) and (2), a drawing process is performed in accordance with information of a print command sent using character data held in a character cache. By doing so, the drawing data is efficiently generated. At this time, the drawing start position is determined based on the presence or absence of the cell information, and the drawing can be performed only in the necessary drawing area, so that the processing speed can be increased. Become.

(4) Effects corresponding to the fourth aspect of the invention In addition to the effects (1) to (3), a bitmap image of a device font rasterized by the printer device and registered in a cache or compressed data thereof. Is released to create a free area necessary for continuation of the processing, so that the processing can be continued even when the character cache or the buffer memory used for drawing characters is insufficient. Also, since the data to be released is the data created on the printer device side, when there is room in the memory,
It can be recreated. (5) Effect corresponding to the fifth aspect of the invention In addition to the effect of the above (4), device fonts that are developed over a plurality of bands and whose drawing is not completed are used even if they are used most recently. It is highly likely that even those that have been referred to will be referenced. Except for such fonts,
Since the fonts that have been used most recently are deleted from the cache in order, it is possible to delete data that is unlikely to be used in order, thereby preventing a decrease in the hit rate due to data deletion and processing. A decrease in speed can be suppressed. (6) Effects corresponding to the invention of claim 6 In addition to the effects of the above (4) and (5), since the bitmap image data of the download font registered in the cache is compressed without being compressed, the printer Even if all necessary bitmap image data of the device fonts generated on the device side cannot be deleted and the required free area cannot be obtained, the processing can be continued.

(7) Effects corresponding to the seventh aspect of the invention In addition to the effect of the above (1), the control unit of the printer device performs the cache operation of the characters of the device font. Only the downloaded fonts need to cache characters. Therefore, when only the device font is used, the character cache operation does not need to be performed on the host computer side, so that the processing can be simplified. (8) Effects Corresponding to the Claim 8 In addition to the effect of (7), caching of device font characters is performed when a drawing command is transmitted to the control unit of the printer device, and Since it is only when it can be registered in the character cache, even if the printer controller deletes the character data and character image data of the device font registered in the character cache,
There is no problem because the data necessary for drawing is sent as a command. (9) Effects corresponding to the ninth aspect of the invention In addition to the effects of the above (7) and (8), when the available memory area becomes insufficient, the device font rasterized by the printer device and registered in the cache Since the processing is continued by deleting the image data of the character and the character data used for rasterization, more memory area can be opened by the amount of the character information data for drawing than in the conventional method. It becomes possible. (10) Effects Corresponding to the Invention of Claim 10 The effects of (1) to (9) above can be obtained by using an image processing system (such as a digital copying machine or a (Including an image data output device) to improve the performance of the image processing system.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part of an embodiment of a printer device according to the present invention.

FIG. 2 shows an example of the configuration of a font cell.

FIG. 3 is a flowchart illustrating an example of a series of print processing operations performed by a print command.

FIG. 4 is a flowchart showing an example of a drawing process operation of a character and a character string shown in FIG. 3;

FIG. 5 is a flowchart illustrating an example of a memory release processing operation.

FIG. 6 is a flowchart showing another example of a character and character string drawing processing operation.

[Explanation of symbols]

Reference numeral 100: printer device 101: interface unit 102: command analysis unit 103
.., Printer control unit, 104, character cache management list, 105, rasterizer, 106, font ROM cartridge, 107, character cache memory, 108, expansion module, 109, frame memory, 110, printing unit, 201, printer driver.

Claims (10)

[Claims] 1. A method of printing character data according to a print command sent from a printer driver in a data format corresponding to the type and use of font data used for printing characters included in a document to be printed and the storage location of the font data. In a printer having printer control means for generating drawing data, the printer control means defines, selects, and deletes a font used for drawing a character included in a document to be printed according to a print command. The operation of registering the character data of the selected font in the character cache according to the font typeface and the drawing command to be used, and the cache data that is registered when it is no longer needed, either all or part of the specified cache data A printer device for performing an operation of deleting data. 2. A printer device according to claim 1, wherein, when registering the character data in the character cache, the font selected for use in drawing is a device font or is already rasterized by a printer driver. Download font, or if it is a download font, whether it is uncompressed or compressed data, contains font cell information, or uncompresses character data rasterized as cache data,
Information indicating which data is to be stored as compressed data is notified by a print command, character data including code data is registered in the character cache in a data format according to the information, and the character data registered in the character cache is deleted A printer command for notifying the user of the deletion of all registered data or deleting data of a specified character code by a print command, and deleting the data in accordance with the information. 3. The printer device according to claim 1, wherein a font used when generating drawing data of a character or a character string for a font selected for use in drawing is a device font. Whether or not it is a downloaded font, whether there is font cell information, if there is no font cell information, use the drawing start point, if there is information, use the placement reference point,
Further, information indicating whether to use data registered in the character cache, whether the data to be used is uncompressed or compressed data, and whether the drawing position is based on relative coordinates or absolute coordinates is a print command. And a drawing device for generating drawing data in accordance with the information. 4. The printer device according to claim 1, wherein the printer control means performs rasterization on the printer device side when a memory used for a character cache or character drawing is insufficient. Release the memory that stores the bitmap image of the device font registered in the character cache or its compressed data until a memory of the required size is obtained, and use the free space to register in the character cache or draw characters. A printer device which continues processing and the like. 5. The printer according to claim 4, wherein the release of the memory is performed with a font that is developed over a plurality of bands when band processing is used to generate drawing data, and the drawing is completed. A printer device, in which the fonts are used in order from the most recently used font, excluding those that do not exist. 6. A printer device according to claim 4, wherein a necessary free area is not obtained even if all bitmap image data of a device font generated by the printer device or its compressed data is deleted. A printer device for compressing bitmap image data of a download font registered in a character cache in an uncompressed state. 7. The printer according to claim 1, wherein
Registration in the character cache included in the print command,
A printer device wherein a delete command is issued only for a character to be rasterized by a printer driver, and only a drawing command is issued for a device font to be rasterized by the printer device. 8. The printer according to claim 7, wherein
The printer control means, when the received print command includes a device font drawing command,
A printer device which determines whether character data of a device font can be registered in a character cache, and if registered, registers and then performs drawing. 9. The printer device according to claim 7, wherein the printer control means performs rasterization on the printer device side and stores it in the character cache when a memory used for a character cache or for drawing characters is insufficient. Release the memory storing the registered device font character data and character image data or its compressed data until a memory of the required size is obtained, and use the free space to register in the character cache or draw characters. A printer device which continues processing and the like. 10. An image processing system comprising the printer device according to claim 1 as a system element.