JPH09164729A - Page printer and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attempt the reduction of a required capacity of a memory and prevent occurrence of an error of a memory-full condition by a method wherein a bit map block memory is provided corresponding to each of plural regions that form a page and a signal indicative of whether a bit map of the corresponding region is stored or not is stored in each bit map block memory. SOLUTION: Each of bit map block memories 32, 34... is provided corresponding to each of plural regions 42, 44... that form one print page 40. A control memory 26 that stores a signal indicative of whether the bit map of the corresponding region 42, 44... is stored or not is provided to each of the bit map block memories 32, 34.... A page description code in a receiving buffer 22 is developed by a CPU 14 in accordance with a procedure in a ROM 16 to be stored in the bit map block memory 32, 34 corresponding to the region. The signal of the using condition is stored in the control memory 26. When a work memory 24 is in a memory-full condition, the bit map block memory 32, 34... of which managing memory dose not store the signal is used as a work memory.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for reducing a required memory capacity in a page printer, or a technique for reducing the frequency of occurrence of a memory full error without increasing the memory capacity.

[0002]

2. Description of the Related Art An ordinary page printer has a bit map memory for one page, and controls printing means based on a bit map stored in the bit map memory to execute desired printing of one page. Here, the bit map has a 1-bit signal for each pixel in the page, and is an array of data indicating the presence or absence of printing for that pixel. In recent years, the number of pixels has increased due to the demand for higher image quality, and the required capacity of the bitmap memory has also increased.

In order for the page printer to function, a bit map memory is secured in its storage means, and a page description code sent from a host computer (which is a computer that generates data to be printed by the printer) is stored. It is necessary to secure a storage area and a work memory used for processing the page description code into a bitmap. If the required capacity of the bitmap memory increases, the storage capacity for other processing will increase. Is reduced, and a memory full error is likely to occur. In particular, the data length of the page description code including graphics changes depending on how complicated the operator who uses the host computer creates a screen, and the capacity of the work area required for that also changes. For this reason, at the printer production stage, the required capacity is estimated by assuming the standard screen complexity and a slight margin is added to it, but there are screens that require more capacity than expected at the time of design. Once created, a memory full error will occur. In order to avoid this, there is no choice but to use a large-capacity storage means.
This increases the production cost of the printer.

[0004]

Therefore, in the present invention, a memory having a limited capacity is effectively used to reduce the required memory capacity, or a memory full error is less likely to occur even though the memory capacity is the same. Realize the technology to do.

[0005]

According to one means of the present invention, in a page printer having a bit map memory for one page, a bit map block corresponding to each of a plurality of areas forming one page. A memory is provided, and a management memory for storing a signal indicating whether or not the bitmap of the corresponding area is stored is provided for each bitmap block memory.

When a bitmap block memory is provided for each of a plurality of areas forming one page, the total storage capacity of the plurality of bitmap block memories is equal to the required capacity of the bitmap memory for one page. . However, depending on the screen, there is a screen that does not require print processing for one or more of the areas, and in such a case, the bitmap block memory for that area is not used. In the case of this means, since the management memory stores whether or not a bitmap is stored for each bitmap block memory,
By this management memory, an unnecessary block memory is specified as a bitmap memory, and this block memory can be used for other processing. Thus, according to this means, the frequency of occurrence of memory full error is reduced. As a result, the need for using an expensive large-capacity storage means to prevent the occurrence of a memory full error is reduced, and an inexpensive printer in which a memory full error does not easily occur can be obtained.

According to another aspect of the present invention, in a method of controlling a page printer having a bit map memory for one page, a bit map for a partial area in a page is stored in a bit map block memory corresponding to the area. Then, the signal indicating the usage status of the bitmap block memory is stored in the corresponding management memory, and at the time of printing, the bitmap indicating the usage status signal is stored in the management memory is stored in the bitmap stored in the bitmap memory. It is characterized by printing based on. According to this method, even if the bitmap block memory corresponding to the area where the printing process is not required is used for other processing, it is based on the data stored in the bitmap block memory for other processing. The desired printing is performed without performing the desired printing. According to this method, it is possible to reduce the occurrence of a memory full error in a limited storage capacity and reduce the need for an expensive storage means with a large storage capacity.

Yet another means of the present invention is a method of controlling a page printer having a work memory used for expanding a page description code into a bitmap and a bitmap memory for storing the expanded bitmap. In, a plurality of areas constituting one page are expanded into bitmaps for each area, the expanded bitmaps are stored in the bitmap block memory corresponding to the area, and the usage status of the bitmap block memory Is stored in the corresponding management memory, and when the work memory is full, the bit map block memory in which the signal indicating the usage state is not stored in the management memory is used as the work memory.

According to this method, the bit map expansion processing can be executed by using the bit map block memory corresponding to the area where the print processing is not required, and if the bit map memory is used without dividing into blocks, a memory full error occurs. Even when the error occurs, the expansion processing to the bitmap can be continued while preventing the occurrence of the memory full error. According to this method, it is possible to reduce the occurrence of a memory full error in a limited storage capacity. In other words, it is possible to reduce the need to use a large-capacity storage means in order to reduce the frequency of occurrence of a memory full error.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred embodiment of the present invention, as illustrated in FIG. 1, a reception buffer 22 for storing a page description code and a processing procedure for expanding the page description code into a bit map are stored. ROM 16 stored therein, CPU 14 that executes processing based on the procedure, work memory 24 that is used to temporarily store data when executing processing based on the procedure, and expanded bitmap In the page printer 10 having the bit map memory 28 for storing the bit map memory 28, the bit map block memories 32, 34 ... Are provided for each of the plurality of areas 42, 44. ..., corresponding areas 42, 44 ...
A management memory 26 for storing a signal indicating whether or not the bitmap of is stored is provided, the CPU 14 expands the page description code in the reception buffer 22 into the bitmap according to the procedure of the ROM 16, and the expanded bitmap is stored. When storing in the bitmap block memories 32, 34, ... Corresponding to the area, a signal indicating the use state is stored in the management memory 26 corresponding to the bitmap block memory, and when the work memory 24 is full, the management is performed. Memory 2
A bit map block memory (one or more of 32, 34 ...) In which a signal indicating a use state is not stored in 6 is used as an extended work memory, and the use state is indicated in the management memory 26 at the time of printing. The printing unit 18 is controlled based on the bitmap stored in the bitmap block memory in which the signal is stored.

The printing means 18 mentioned here is a general term for means which directly comprises a print head, a mechanism for moving the print head left and right, a paper feed mechanism, etc., and which directly contributes to the printing process.
This is controlled by the CPU 14 during the printing process based on the procedure stored in the ROM 16 and the bitmap stored in the bitmap memory 28. The RAM 20 does not have to be composed of one element, but may be physically composed of a plurality of elements. The present invention can be embodied not only in a monochrome printer but also in a color printer. In particular, the present invention can be applied to each color in a color printer having a bitmap memory for each color.

[0012]

Next, an embodiment of the present invention will be illustrated. In the following embodiments, the case of printing the page 40 shown in FIG. 2 will be described as an example. Further, as shown in FIG. 2, one page is divided into four areas 42, 44, 46 and 48, and bit map block memories 32, 34, 36 and 38 are provided for the respective areas 42, 44, 46 and 48. Indicates. The number of pages to be divided may be two or more.

Each bitmap block memory 32, 3
4, 36 and 38 have the same number of bits as the number of pixels in each of the areas 42, 44, 46 and 48. In this example,
An example in which one page is composed of 2481 × 3508 pixels is shown. Since the areas of the regions 42, 44, 46, 48 are equal, the bitmap block memories 32, 34, 36,
38 has a capacity of 2481 × 3508/4 bits. The specific address in the bitmap memory is page 4
Corresponding to a specific pixel within 0, the presence or absence of printing for that specific pixel is controlled by the data of the address. FIG.
In the case of, the case where two circles 52 and 54 are printed in the page 40 is illustrated.

FIG. 3 schematically shows the contents of the page description code sent from the host computer 8 and stored in the reception buffer 22, and is used to define the print screen such as the position and shape of each figure. It contains necessary information with a small storage capacity. This page description code is a code that is easy to describe for an operator who uses the host computer 8, and has a small data capacity, but it is difficult to control the printing means 18 as it is. A bitmap is needed to finally control the printing means 18. The page description code sent from the host computer 8 is temporarily stored in the reception buffer 22 via the interface 12.

When a predetermined amount of page description code is input to the reception buffer 22, the CPU 14 calculates the bit map corresponding to the drawing described by the page description code based on the program (procedure) of the ROM 16. After that, this will be expanded into a bitmap. In this expansion processing, in the case of the example, a radius of 25 with the center coordinate at (2000, 2250)
In order to draw a circle of 0, a geometric operation such as which pixel to print is performed. If a part of the page description code is a character code, a bitmap in a font ROM (provided in the ROM 16) corresponding to the character code prepared in advance is searched and the bitmap is stored in the bitmap memory 28. The process of copying to.

In FIG. 4A, the central coordinates are (2000, 22)
FIG. 50 schematically shows how the page description code for drawing a circle having a radius of 250 in FIG. 50) is expanded in the bitmap memory 28. The bitmap memory 28 shows the data of the corresponding address in accordance with the spatial position of the corresponding pixel,
Black is shown as corresponding to the data that achieves printing for that pixel, and white is shown as corresponding to the data that does not perform printing for that pixel. Before being expanded into a bitmap, the management area 26 stores information indicating an unused state or no bitmap stored as an initial value. In the case of FIG. 4 (A), as a result of expanding into the bitmap, the bitmap is expanded and stored in the bitmap block memory 36 corresponding to the area 46, and corresponding to the area 46 or the block memory 36. This indicates that the management area 26-3 has been rewritten into information indicating the state of use or bitmap storage. FIG. 4B shows a state in which two graphic codes are further expanded into a bitmap.

In FIG. 5, after the printing process for one page is completed,
While the next page is being printed, the CPU 14 shows the processing contents to be processed using the RAM 20 by the program in the ROM 16, and first initializes all the contents of the management areas 26-1 to 26-4 to an unused state, Next, the page description code is stored in the reception buffer 22 from the host computer 8 via the interface 12 (104). After a predetermined amount of code is input, it is developed into a bitmap and the bitmap is stored in the bitmap memory 28 (10
6). At this time, information indicating that the used or bitmap has been stored is added to the management memory corresponding to the block memory in which the bitmap has been stored (108).
This is repeated for all page description codes until one page is completed (110).

The work memory 24 is used in the process of expanding the page description data into a bit map. The work memory 24 is used in such a manner that the data used for the expansion process is accumulated and stored in preparation for printing a similar figure on the next page, for example. As a result, as the expansion process progresses, the unused work area decreases and the memory becomes full.

For example, in FIG. 4B, the center coordinate is (100
0, 1875) has a code of a circle with a radius of 500 and is expanded into a bitmap. There is a possibility that the work memory 24 becomes full during the execution of this processing and the expansion processing to the bitmap becomes inexecutable.

FIG. 6 shows a procedure executed when the work memory 24 stored in the ROM 16 is full. Process 2 when the work memory 24 becomes full
02 is executed, the information of the first management memory, in this case, the management memory 26-1 is read, and it is determined whether this is used or unused (204). If it is not used, the corresponding bitmap block memory 32 is set as an expanded work memory (206), and it is determined whether or not the capacity of the expanded work memory can secure the capacity necessary for the expansion processing (208). ). If sufficient work memory is secured, the process proceeds from the block memory 32 to an expanded work memory thereafter (216). This achieves the memory full measure. When it is not enough to expand one block memory (when N in 208), it is searched whether the next block (212) is available until the last block (210) (204),
The bitmap block memory is diverted to the expanded work memory until the required capacity is secured (206).
If the required capacity cannot be secured even after searching to the last block memory, or if there is no block memory that can be used as a work memory because the bitmap is expanded in all block memories, the processing to generate a memory full error is performed. Perform (214). In this case, even if all the storage capacity is used without waste, the memory is still full, which cannot be overcome by the present invention.

FIG. 4B shows a bit map block memory which is not used even though the work memory 24 becomes full during the process of expanding the second page description code into the bit map. As an example, as a result of developing into a bitmap using 32, the example in which the development into the bitmap corresponding to the second circle is successful is illustrated. Since the bitmap is also stored in the block memory 34 by this processing, the corresponding management memory 26-3 is also rewritten into the used state.

After the process 300 shown in FIG. 5, the procedure for executing the printing process by controlling the printing means 18 after expanding one page into the bitmap will be described. First, the area to be printed first (in this case, Is 42, but when printing from the bottom, it is judged whether or not the information indicating being in use is stored in the management memory 26-1 related to the bitmap block memory 32 corresponding to 48). The engine (printing unit 18 in this case) is instructed to feed the paper by the amount corresponding to the area 42 (302), and the printing for the area 42 is skipped (304). In this case, instead of sending the paper feed signal, the data instructing not to print (so-called NULL data) may be output to the engine by the amount corresponding to the area 42. On the other hand, if it is in use, the bitmap in the block memory is sent to the engine (printing unit 18) to execute printing in the area 42 (308). In this case, the engine 18 is controlled based on the bit map, and since the bit map is expanded from the page description code, the printing for the page description code is executed. The above process is repeated up to the last block memory or area (312) to print one page.

In the above embodiment, the bitmap memory 2
A bit map memory for storing a bit map for one page is constituted by 8, and the bit map memory 28 is divided into bit map block memories 32, 34, 36, 38 corresponding to the areas 42, 44, 46, 48. To be done. Management memories 26-1, 26-2, 26-3, and 26-4 are provided corresponding to the bit map block memories. Further, as typically illustrated in FIG. 4A, the bitmap corresponding to a partial area (46 in this case) in the page is stored in the bitmap block memory 36 corresponding to the area, and at that time, In addition, a signal indicating the use state is stored in the management memory 26-3 corresponding to the block memory (106 and 108 in FIG. 5), and at the time of printing, stored in the bitmap block memory in which the signal indicating the use state is stored. Print based on the bitmap
6, 308), and printing based on the data in the unused block memory is not performed (302, 304).

Further, when the work memory 24 is full, a search is made for a block in the management memories 26-1 to 26-4 in which a signal indicating the use state is not stored (see 20 in FIG. 6).
4) The process of using the searched block as a work memory is executed (206). In this embodiment, the regions are divided into horizontal stripes, but can be divided into vertical stripes or can be divided into lattices, and there is no particular limitation on the mode of division.

[0025]

As a result, according to the prior art, the result is that, most typically, some areas have very complex features while other areas do not need to be printed. ,
Even if the print job cannot be executed because the work memory becomes full due to the processing for the complicated image existing in a part of the area, the occurrence of the situation where the work memory becomes full is avoided, and it is limited. It is possible to effectively use the storage capacity and suppress the occurrence frequency of the memory full error.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a preferred embodiment of the present invention.

FIG. 2 is a diagram showing an example of a page to be printed.

3 is a diagram schematically showing the contents of a page description code for the page of FIG.

FIG. 4 is a diagram schematically showing a state in which a first circle is developed on a bitmap and a diagram schematically showing a state in which a second circle is developed on a bitmap.

FIG. 5 is a diagram showing an overall flow of a processing procedure executed in processing of one page.

FIG. 6 is a diagram showing a processing procedure executed when the memory is full.

[Explanation of symbols]

 18 printing means (engine) 22 receiving buffer 24 work memory 26 management memory 28 bit map memory 32, 34, 36, 38 bit map block memory

Claims (3)

[Claims] 1. A page printer having a bit map memory for one page, wherein a bit map block memory corresponding to each of a plurality of areas forming one page is provided, and each bit map block memory is provided. , A page printer provided with a management memory for storing a signal indicating whether or not a bitmap of a corresponding area is stored. 2. A method of controlling a page printer having a bitmap memory for one page, wherein a bitmap for a partial area in a page is stored in a bitmap block memory corresponding to the area, and the bitmap block memory A feature is that a signal indicating a usage state is stored in a corresponding management memory, and at the time of printing, printing is performed based on a bitmap stored in a bitmap block memory in which the signal indicating the usage state is stored in the management memory. How to control the page printer. 3. A page printer control method having a work memory used for processing a page description code into a bitmap and a bitmap memory for storing the expanded bitmap, wherein a plurality of pages compose one page. Each area is expanded into a bitmap for each area, the expanded bitmap is stored in the bitmap block memory corresponding to that area, and the signal indicating the usage status of the bitmap block memory is stored in the corresponding management memory. A method of controlling a page printer, wherein a bitmap block memory, which is stored and in which a signal indicating a use state is not stored in the management memory, is used as a work memory when the work memory is full.