JPH08234939A - Printer device and its data managing method - Google Patents

Abstract

PURPOSE: To provide the printer device and its data managing method which can efficiently compress data on a memory. CONSTITUTION: The printer device, which executes a printing process by switching applications according to a print command from an external equipment, stores plural application programs in a ROM 213 and arranges data used by corresponding applications in a RAM 213 successively according to the attributes of the data. Then it is decided whether or not the application indicated by the print command is currently executed; when the application is not being executed, the data in the work area corresponding to an application that is being executed at this time are compressed, and the process is moved to the application in instructed with the print command among the stored application programs to perform a printing process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus which receives a print command from an external device, analyzes the print command, switches to an application for execution, and prints, and a data management method in the apparatus.

[0002]

2. Description of the Related Art In recent years, there are various types of printer devices which are connected to computer equipment which has been rapidly spread and which receive print data from the computer equipment and print it. Among these printer devices, in the case of a printer device that receives a character code and prints only characters of a certain size, like the initial printer device, the main function of the printer device is to change the sent character code. It was enough to interpret and expand it into a character pattern. However, as in recent years, as the typeface and size of characters are changed and images are printed, the demands on the functions of the printer device are becoming more and more complicated and diversified. Along with this, the commands and print data sent from the computer equipment to the printer become complicated, and it becomes necessary for the printer to input print commands incorporating these various commands and interpret them. .

However, since the command system used in the printer device is originally developed for each maker and device, it is the current situation that they are not compatible with each other. Further, the software of the computer device (host) also supports such a plurality of print command sets, but not all print command sets. Therefore, it is necessary to incorporate a plurality of print command sets in the printer device so that any computer device can perform print output.

In general, a printer device is often supplied with print commands from a plurality of computer devices. Therefore, unless an application interpreting each print command can be started up without restarting the printer device, The operability will be extremely poor. This is because when the application is started, it takes a long time to expand the character information and the like in the work area, so that it takes a lot of time to switch the application. Thus, the printer device must be able to switch between a plurality of applications in an instant.

If the control unit of the printer apparatus can allocate resources such as independent memories to the respective applications, the applications can be easily and instantly switched without restarting the printer apparatus. Resources such as memories for a plurality of operating printer devices are required, which is not practical in terms of cost.

[0006]

Therefore, a technique for temporarily saving the work area of the application on the memory and sharing the memory between different applications is required. In computer equipment and the like, it is possible to switch applications at high speed by temporarily saving the work area on RAM to a secondary storage area such as a hard disk and then launching other applications. In the case of a printer device, it is difficult to provide such a secondary storage device in terms of cost.

The present invention has been made in view of the above-mentioned conventional example, and an object of the present invention is to provide a printing apparatus and a data management method in the apparatus which can efficiently compress data on a memory.

Another object of the present invention is to provide a printing apparatus and a data management method in the printing apparatus, which can perform printing by switching applications executed in the printing apparatus at high speed in response to a print command from an external device. Especially.

Another object of the present invention relates to a printing apparatus and a data management method in the apparatus, which are capable of efficiently compressing data and ensuring a sufficient work area for executing an application.

[0010]

In order to achieve the above object, the printing apparatus of the present invention has the following configuration. That is, a printing apparatus that executes a printing process by switching an application in accordance with a print command from an external device, and corresponds to each of the storage means for storing a plurality of application programs and each of the plurality of application programs. A work area for continuously arranging data according to the attribute of data used in a corresponding application and an application program stored in the storage means, which is designated by an application designated by the print command. It has a control means for migrating the processing and a compression means for compressing the data in the work area when the application is migrated by the control means.

In order to achieve the above object, the data management method in the printing apparatus of the present invention comprises the following steps. That is, it is a data management method in a printing apparatus that executes a printing process by switching an application according to a print command from an external device. Data used by an application being executed is continuously stored in a memory according to its attribute. And a compression step of compressing the data in the memory corresponding to the application being executed at the time of shifting to the application instructed by the print command.

[0012]

In the above structure, a plurality of application programs are stored in the storage means and provided corresponding to each of the plurality of application programs, according to the attribute of the data used by the corresponding application. Data is continuously stored in the work area. Among the plurality of application programs stored in the storage means, when the processing is transferred to the application instructed by the received print command, the data stored in the work area is compressed.

Further, according to the data management method of the present invention, when data used by an application being executed is continuously arranged in a memory according to its attribute, and is transferred to the application instructed by the print command. ,
Compress the data in memory that corresponds to the application that is currently running.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings, an outline of the processing of one embodiment of the present invention will be briefly described below.

In the case of compressing data, a method in which highly correlated data are continuously arranged can be expected to have high compression efficiency, as compared with the case where the data to be compressed are arranged at random. Generally, in the work area of the RAM, various data formats used by software are randomly mixed. This is separated into a character string format, an integer, address information, etc. for each data type, and data having the same data attribute is continuously arranged in the same area. For example, when the character string information is collected, if it is an English text, the character code thereof often takes a value less than "127" (07FH: H is a hexadecimal number), and the correlation of the character arrangement is also high. Similarly, in the case of the Japanese JIS code, the codes are not evenly distributed within the range of "0" to "255" for both the upper byte and the lower byte, and only a value within a certain range can be taken. A character code compression effect can be expected. Further, the address information is, for example, when the internal representation of the address is 32 bits long and the installed memory is 16 Mbytes (= 2 to the 24th power), the most significant byte is always a constant value if it is a continuous address. It can be expected that the same value will occur periodically. In such a case, a high compression effect can be expected.

FIG. 6 is a diagram showing the data appearance probability for each byte corresponding to the data attribute. The vertical axis shows the appearance probability and the horizontal axis shows the byte value. In addition, these FIG.
In (a) to (f), the vertical scales are not the same. Here, it is considered that the more efficient the appearance probability is, the less expected the compression efficiency is.

FIG. 6A is a diagram showing the appearance probability of the value of each byte of the JIS code. The lower byte of the JIS code is limited to the range of "21H" to "07EH" (H represents a hexadecimal number) in hexadecimal number, and the upper byte is also "2".
1H "to" 74H "and the value of the upper byte is" 5 "
Since 0H "or more corresponds to the second-level Chinese character, its appearance frequency is low. Also, since there is an empty area in which the corresponding JIS code does not exist, such a distribution is obtained.

FIG. 6B is a diagram showing the appearance probability of the value of each byte of 16-bit and 32-bit integers. Since it is a general integer, there is almost no difference in its appearance frequency. However, in reality, it is considered that the frequency of appearance varies depending on the nature of the program. Further, when 16-bit data is not stored in a top-justified manner and is arranged as a 32-bit word, the appearance frequency of the data stored in the empty area of the upper byte may change depending on the data.

FIG. 6C shows the appearance probability of the value of the most significant byte of the address information. However, the distribution is in the case of a memory map as shown in FIG.

FIG. 6D shows the appearance probability of the next byte of the address information.

FIG. 6E shows the appearance probability of the third byte value of the address information.

FIG. 6 (f) shows the appearance probability of the lowest byte value of the address information. In this least significant byte,
Since there are many 32-bit units of data, the numerical value fluctuates periodically every 4. In these figures, the period and the interval are not accurate because they cannot be shown accurately.

As described above, according to this embodiment, the numerical distribution (probability of occurrence) differs depending on the type of data.
The purpose of the present invention is to compress the data more efficiently by separating the data for each attribute and compressing the data using the appearance probability of the data.

An embodiment of the present invention will be described in detail below.

FIG. 2 is a block diagram showing the arrangement of the printer device 200 of this embodiment.

Reference numeral 201 denotes a host computer, which sends print commands and various data described in a page description language to the printer apparatus 200 of the embodiment to execute printing. An input / output unit 210 controls transmission / reception of data between the host computer 201 and the printer device 200. The input / output unit 210 may have an interface unit according to a print command such as Postscript or page description language transmitted from the host computer 201. Reference numeral 211 denotes a CPU, which controls the overall operation of the printer device 200 of the embodiment. Reference numeral 212 is a RAM portion of the main memory, and 213 is a ROM portion thereof, the data structure of which will be described later with reference to FIG. An engine unit 214 prints an image on a recording medium such as a recording sheet according to a print image sent from the CPU 211 by, for example, a laser beam printing method, an inkjet method, a thermal printing method, or a thermal transfer method.

In the above configuration, the ROM 213 portion stores each application program executed in response to the print command received from the host computer 201, font data, and various data. C
The PU 211 selects an application to be executed according to the print command received from the host computer 201, and uses the application to analyze the print command, develop the image into an image, and the like. Further, the RAM 212 is provided with a work area (work area) used according to the execution of each application, and the CPU 211 changes the work area used according to the switching of the application. By compressing the data in the work area of an unused application when switching the application, the memory space of the work area of the RAM 212 that can be used freely is increased, and the execution of the application is made easier.

FIG. 1 shows a printer device 200 which switches a plurality of applications and prints out data of different code systems received from a host computer 201.
3 is a diagram showing an example of a memory map of a RAM 212 and a ROM 213 in FIG.

This memory map shows the case where work areas of a plurality of applications are made resident in the memory without performing data compression of the RAM 212 at all. Of the work areas of each application, the page memory, the buffering of received data, the storage area of intermediate data during processing, and the like are commonly used, so that the RAM 21 is used.
The area for storing the internal settings of the application, etc. is provided separately.

In FIG. 1, 213 is a ROM area,
It has a memory space of 8 Mbytes. 100 is the code area (program area) of application A, 101
Is the code area of application B, and 102 is the code area of application C. Reference numeral 103 denotes a font data storage area. A common code area 104 does not depend on the application.

Explaining the structure of the RAM 212, 2 is an image development area of the page memory, and 3 is a free area used for buffering received data, storing intermediate data, and the like. The image development area 2 and the free area 3 are commonly used by each application,
It is initialized each time a different application is started. In general, the larger the memory space of the free area 3, the more data can be buffered. This allows
The host computer 201 can be released more quickly than the print data transfer process, and more font data can be cached to speed up print output.

Reference numeral 11 indicates a work area of the application A (work area), 12 indicates a work area of the application B, and 13 indicates a work area of the application C. In FIG. 1, the total area of the memory space of the work areas 11 to 13 of these applications is about 2.2 Mbytes (about 200,000 H) out of 6 Mbytes (address 600,000 H) of the entire RAM area. The memory area of the free area 3 is about 300 Kbytes.

In FIG. 3, for example, the application C is activated, and the work areas 11 and 12 of the other inactive applications (applications A and B).
It is a figure which shows the content of the memory map in the state which was compressed.

Here, only the application C is active, and each of 11-1 and 12-1 is
The work areas of the compressed applications A and B are shown, and they are in a non-compressed state (work areas 11 and 1 in FIG. 1).
It is compressed to about 30% of the memory space of 2).

As shown in FIG. 3, by compressing the work areas 11 and 12 of each application, a work area of at least about 1 MB is secured in the RAM 212 as compared with the case of FIG. If the final address of this memory (RAM212) is 80600000H
If the memory space of the RAM 212 is 6 MB at the address, an extra memory area of about 1.3 MB that can be used freely can be secured in the case shown in FIG. This allows
Since the work area that can be freely used increases, the area can be used for expanding the font cache area when the application C is executed, so that the workability can be improved and the printing speed can be improved.

In this embodiment, three applications are shown for simplification of the drawing, but the present invention is not limited to this. Also, in practice, the work area dedicated to each application is often smaller,
Instead, the number of applications is large and the work area as shown is required.

Next, a method of compressing such data based on the attribute of the data will be described.

FIG. 4 is a diagram for explaining a data structure created in C language or the like. FIG. 4A shows a bidirectional list, pointers to data, and some definition examples of integers and character strings. Is shown. Here, "data" is the character type, "count" is a 32-bit integer, and "left".
And "right" are defined in the address. Also, "flag" is defined as a 16-bit integer.

Although these depend on the processing system, for example, in a certain 32-bit processing system, they are stored in the memory as shown in FIG. 3B. With this arrangement, "lev
Since both "t" and "right" are addresses, there is data correlation, but between "data" and "count",
Between "count" and "flag", "flag" and "l"
There is no correlation between the data in “eft”. In addition, the variables before and after these, "data" and "r
It is unlikely that the attributes of “light” match.

As described above, when compressing data, if the data of the same structure are continuously arranged, the compression rate is increased, and a higher compression rate can be expected. In case of, higher compression effect cannot be expected.

Therefore, in the present embodiment, the compression effect is further enhanced in the subsequent compression process by storing the data of this leveler by dividing it into respective attributes.

That is, in FIG. 4B, "dat
"a", "left", and "right" are all treated as 32-bit address information. Further, as "count" is a 32-bit integer and "flag" is a 16-bit integer, data having the same attribute is continuously stored as shown in FIG. 4C.

In the case of the data structure on the memory as shown in FIGS. 1 and 3 of the present embodiment, when the address information is displayed in hexadecimal, the possible range of the address is 0000.
0000H-007f0000H, or 800,000
It is limited to the range of 00H to 805fffffH. Also, since it does not point to an address other than your own area,
The range of this address is further limited. In this case, the value of the most significant byte is “00” or “80”, and the value of the next most significant byte is “2” if the value of the most significant byte is “00”.
Possible values are 3 "to" 7f ", and if" 80 "," 00 "
It can take a value of "3c".

As described above, according to this embodiment, a high correlation is recognized in the address values that access this memory space. Further, since the least significant byte is always "0" (accessed in 4-byte units) except for the character string pointer, this address can also be expected to have a high compression effect.

For example, in LZW compression or the like, when address information and other information are randomly mixed and when the address information is separated, when the address is separated, a compression ratio of several percent is obtained. There is an improvement.

The processing in the printer apparatus 200 of the present embodiment based on the above configuration will be described with reference to the flowchart of FIG. The control program for executing this process is stored in the common code area 104 of the ROM 213.

The process shown in the flow chart of FIG. 5 is started when the power of the apparatus is turned on, and first, step S
In step 1, the entire initialization setting is performed to initialize each application, and in step S2, the application set by default is activated to wait for reception of print data from the host computer 201.

In step S3, the host computer 20
When the data of 1 is received, the process proceeds to step S4, and the application to be executed is selected according to the received data or the received interface. It is determined whether the selected application is the currently active application, and if so, the process proceeds to step S7, and the code 100 of the corresponding application is directly used.
Control is transferred to the program in any one of the areas 1 to 102, data is received from the host computer 201 (step S7), the print command is analyzed, developed into a print image and printed (step S8). In this way, when the predetermined amount of printing (one print job) received from the host computer 201 is completed in step S9, the process returns to step S3 and waits for the next print command.

On the other hand, if the application selected by the print command received from the host computer 201 is inactive at that time, the process proceeds from step S4 to step S5, and the work area of the application that is active at that time. Data in (work area) is compressed and saved. Then, the work area of the application requested by the print command is expanded, and control is transferred to the corresponding application. Next, in step S6, the image development area 2 and the free area 3
Initialize the shared data area of. When a new application is started in this way, the print data sent from the host computer is received and interpreted (step S
7) The printout is performed (step S8). Thus
When the print process corresponding to the print job corresponding to the application is completed, the process returns to step S3 and waits for the next print command.

Here, in step S5, the RAM 2
In the work areas 12 of the respective applications, for example, as shown in FIG. 4 described above, since the data having the same data attributes are continuously stored, the data compression efficiency can be further improved.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. The present invention can also be applied to the case where it is achieved by supplying a program for implementing the present invention to a system or an apparatus.

As described above, according to the present embodiment, when compressing the work area of an inactive application in a printer device that switches and uses a plurality of applications, it is possible to use By continuously storing in the memory for each data having the same attribute, the data compression efficiency can be improved and the memory can be used more efficiently.

[0053]

As described above, according to the present invention, the data on the memory can be efficiently compressed.

Further, according to the present invention, it is possible to perform printing by switching the applications executed in the printing device at high speed in response to a print command from an external device.

Further, according to the present invention, there is an effect that data can be efficiently compressed and a work area for executing an application can be sufficiently secured.

[0056]

[Brief description of drawings]

FIG. 1 is a diagram showing a memory map when data compression is not performed in the printer apparatus of the present embodiment.

FIG. 2 is a block diagram showing a schematic configuration of a printer device of the present embodiment.

FIG. 3 is a diagram showing a memory map when data relating to an inactive application is compressed in the printer device of the present embodiment.

FIG. 4 is a diagram for explaining an example of data defined by C language, (a) is a diagram showing an example of C language defining a data structure, and (b) is data defined by C language. FIG. 3C is a diagram showing how the structures are arranged, and FIG. 6C is a diagram showing a data array separated and arranged according to the attribute of the data according to the present embodiment.

FIG. 5 is a flowchart showing a process in the printer apparatus of this embodiment.

FIG. 6 is a diagram showing appearance probabilities according to data, FIG. 6A is a diagram showing distribution probabilities of values of each byte of JIS code,
(B) is a diagram showing a distribution probability of each byte value of 16-bit and 32-bit integers, (c) is a diagram showing a distribution probability of a value of the most significant byte of the address information of the present embodiment, and (d) is The figure which shows the distribution probability of the next byte of address information of a present Example,
(E) is a diagram showing the distribution probability of the third byte of the address information of this embodiment, and (f) is a diagram showing the distribution probability of the value of the least significant byte of the address information.

[Explanation of symbols]

 2 image development area 3 free area 11 work area of application A 12 work area of application B 11-1 work area of compressed application A 12-1 work area of compressed application B 13 work area of application C 20 application Common work area that does not depend on 100 Code area of application A 101 Code area of application B 102 Code area of application C 103 Font data storage area 104 Common code area 200 Printer device 201 Host computer 211 CPU 212 ROM 213 RAM

Claims (6)

[Claims] 1. A printing apparatus for executing a printing process by switching an application in accordance with a print command from an external device, the storage device storing a plurality of application programs, and each of the plurality of application programs. A work area, which is provided correspondingly and in which data is continuously arranged according to the attribute of the data used by the corresponding application, and an application program stored in the storage unit, which is instructed by the print command. Control means for migrating processing to the application, and when migrating the application by the control means,
And a compression unit that compresses data in the work area. 2. The application designated by the print command uses the usable area of the work area expanded by the data compression by the compression unit when the application is executed. The printing device described. 3. The compressing unit determines whether or not an application instructed by the print command is being executed at that time, and when the application is not being executed, corresponds to the application being executed at that time. The printing apparatus according to claim 1, wherein the data in the work area is compressed. 4. A data management method in a printing apparatus for executing a printing process by switching an application in accordance with a print command from an external device, wherein data used by the running application includes:
It has a step of continuously arranging in the memory according to the attribute, and a compression step of compressing the data in the memory corresponding to the application being executed at the time of shifting to the application instructed by the print command. A data management method in a printing apparatus, comprising: 5. The compressing step determines whether or not an application instructed by the print command is being executed at that time, and when the application is not being executed, the memory of the memory corresponding to the application that has been executed until then is determined. The data management method according to claim 4, wherein the data is compressed. 6. The method further comprises a step of migrating the processing to the application instructed by the print command among the stored application programs when the application instructed by the print command is not being executed at that time. A data management method in a printing apparatus according to claim 4, wherein: