JP3450961B2 - Printing apparatus and control method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer and a control method thereof, and more particularly to a printer and a control method thereof which can reduce the memory capacity of intermediate data.

[0002]

2. Description of the Related Art In a host computer such as a personal computer, an operator directly draws a screen using a page description language, or a page description code corresponding to the screen is input (that is, a code defining the screen or data is input). Create drawing data by using the automatically created drawing application software. This page description language is
It is designed so that it is easy for the operator to recognize and the number of input data is small. According to the method in which the host computer side develops the code into a bitmap and sends the developed bitmap to the output device side to perform necessary output, the load on the host computer increases. Therefore, the process of expanding the code into a bitmap is performed on the output device side.

When the code is expanded into a bit map, a method of once converting it into intermediate data of a format suitable for printer control has become widespread. For example, when the code is "draw a circle", first, it is converted into data showing a regular polygon having many vertices and stored in memory, and the "circle" is drawn on the page. Data indicating the position is also stored. When converted into intermediate data of this format, when performing printing processing, it is possible to develop a bitmap into a bitmap at a higher speed than when the code "draw a circle" is directly expanded to the bitmap. Various formats have been proposed for this intermediate data, and as described above,
An example in which a curved figure is transformed into an approximate linear figure and the coordinates of its vertices are stored (hereinafter referred to as a vertex format. Polygon intermediate data described later also belongs to this format), pixel forming means (for example, in a laser printer). (Laser in this case) for each scanning line, it is converted into data indicating the print start position and print end position (for example, the start point and end point of the black pixel, or the continuous length of the start point and the black pixel). Examples (hereinafter referred to as run length format) exist. Further, a method called band processing has become widespread in order to develop a page description code for one page into a bitmap. In this method, one page is made up of a plurality of areas (each area is called a band), each area is developed into a bitmap, and sequentially printed.

In this case, as shown in FIG. 4, two band buffers 2 for temporarily storing the expanded bitmap are used.
3 and 24 are used to display or print one area based on the bitmap stored in one of the band buffers 23, and at the same time, develop the next band (area) into a bitmap. The processed bitmap is expanded and stored in the other band buffer 24. In this way, when the output for one area and the expansion of the bitmap for the next area are completed, then the output to the next area (band) is continued by the bitmap expanded in the other band buffer, At the same time, the process of expanding to a bitmap in another band (region) is continued. ~ Indicates the order of the above operations. In addition, and are processed in parallel, similarly and are processed in parallel, and further, are processed in parallel. According to this method, it suffices to use two band buffers having a storage capacity capable of covering a partial area in one page. Therefore, by dividing one page into three bands (areas) or more, development is performed. It is possible to reduce the total storage capacity of the band buffer that stores the stored bitmap.

[0005]

In most of the above-mentioned conventional examples, the capacity of polygon intermediate data is smaller than the capacity of bitmap intermediate data (intermediate data obtained by converting polygon intermediate data into bitmap). All image code data is converted into polygonal intermediate data and stored in the data memory. However, when the capacity of the bitmap intermediate data is smaller than the capacity of the polygon intermediate data, there is a disadvantage that the capacity of the intermediate data memory required to store the polygon intermediate data becomes large. Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the conventional example, and to reduce the capacity of the intermediate data memory even when the capacity of the polygonal intermediate data is larger than the capacity of the bitmap intermediate data, and the control thereof. Is to provide a method.

[0006]

In order to solve the above problems, the structure of the first invention of the present application is a page input from the outside.
A printing device that prints based on a description code and controls
Means, a plurality of intermediate data storage means, and at least two
Each band buffer is equipped with a band buffer of
The fa corresponds to one area obtained by dividing one page into a predetermined number.
It has a capacity and the control means is a page input from the outside.
The description code is analyzed and the first intermediate data is analyzed for each page description code.
Data capacity or second intermediate data format is small
Select which data format you want and convert it to intermediate data
The data is stored in the data storage means and the converted intermediate
On the page of the figure described by the page description code corresponding to the data
To obtain the instruction data indicating the position at
Serial to correspond to the intermediate data memorize, serial for each page description code
The stored intermediate data is stored in the finger corresponding to the intermediate data.
The bitmap data is expanded based on the position indicated by the indicated data.
Open it and store it in the band buffer.
Printing based on the bitmap data stored in the buffer
A printing device characterized by the following.

With the configuration of the first invention, the first intermediate data
It will be stored smaller capacity of over data format or the second intermediate data format can Reducing the capacity of the intermediate data storage unit.

Further, the structure of the second invention is described in claim 1.
The printing device on-board, which is converted in the first intermediate data format.
The intermediate data is a vertex format that represents the shape of the figure in coordinates.
This is rectangular intermediate data, which is converted in the second intermediate data format.
The intermediate data is a polygonal intermediate data that has been converted into a bitmap.
Printing device characterized by being bitmap intermediate data
It is a place.

According to the configuration of the second invention , the first
With the operation of the invention , the intermediate data in the first intermediate data format is
Data is polygonal intermediate data, and is in the second intermediate data format.
Since the intermediate data according to is the bitmap intermediate data,
Since the bitmap intermediate data can be converted into the bitmap data at a higher speed than the polygon intermediate data is expanded into the bitmap data, the printing speed of the printing apparatus can be increased.

Further, according to the third aspect of the invention , an external input is used.
1 page is divided into a predetermined number based on the page description code
A method for controlling a printing device that prints in each area
The page description code input from is analyzed and the page description code
For each, the first intermediate data format or the second intermediate data format
Select the data format with the smaller capacity
Data is stored in the converted intermediate data.
On the page of the figure described by the page description code corresponding to
Find the instruction data indicating the position, and
Stored in correspondence with the inter-data, and stored for each page description code
Instruction de wherein the intermediate data, corresponding to the intermediate data
Expanded to bitmap data based on the position indicated by the data
Then, correspond the developed bitmap data to each area.
Bitmap data that is stored and stored in association with each area
Control of a printing device characterized by printing based on
Is the way.

With the configuration of the third invention, as in the first invention, the first intermediate data format or the second intermediate data is formed.
Since the one with the smaller capacity is stored, the capacity of the intermediate data storage means can be reduced.

Further, the structure of the fourth invention is described in claim 3.
A method for controlling the printing device according to claim 1, wherein the first intermediate data format
The intermediate data converted by
It is the polygon intermediate data represented by, and is the second intermediate data format.
The intermediate data converted by
It is characterized by being bitmap intermediate data
And a method for controlling a printing device.

According to the structure of the above-mentioned fourth invention , the above-mentioned third invention is provided.
With the operation of the invention , the intermediate data in the first intermediate data format is
Data is polygonal intermediate data, and is in the second intermediate data format.
Since the intermediate data according to is the bitmap intermediate data,
As described above, since it is possible to convert bitmap intermediate data into bitmap data at a higher speed than to expand polygon intermediate data into bitmap data, printing
The printing speed of the device can be increased.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram for carrying out an embodiment of the present invention, and more specifically, shows a control system of a printing apparatus for executing both conversion processing into intermediate data and band processing. The printer 1 is used by being connected to a host computer 2 through a signal line 3 and uses a CPU 4
Built-in computer system centered around. That is, CPU 4, interface 5, ROM 6, RAM
7 are connected by a bus 8 to form a computer system, and the printing means 9 is controlled by this computer system. The interface 5 sends and receives data to and from the host computer 2.

A program for receiving the page description code 10 sent from the host computer 2 and storing it in the reception buffer 11 is analyzed in the ROM 6, and the page description code 10 stored in the reception buffer 11 is analyzed to appropriately generate intermediate data. A program for converting to, a program for creating bitmap data based on the converted intermediate data, a program for controlling the printing unit 9 based on the created bitmap data, and the like are stored, and these programs are appropriately stored by the CPU 4. Is executed. In addition, in case the page description code 10 is a character code, the font ROM 12 stores a shape for forming a character specified by the character code as bitmap data or outline data. In the RAM 7, the reception buffer 1
In addition to 1, an area for storing intermediate data corresponding to each band 13, 14, 15 on one page (hereinafter referred to as a block).
(16, 17), (18, 19), (20, 21),
Two band buffers 23 and 24 and work memory 22
have. The work memory 22 is used to temporarily store various data when the CPU 4 performs processing based on each of the above programs.

Blocks (16, 1) for storing intermediate data
7), (18, 19) and (20, 21) exist as many as the number of bands (areas) dividing one page, and intermediate data are stored for each band. The intermediate data is composed of a packet and shape intermediate data or character intermediate data. The shape intermediate data includes polygonal intermediate data that represents the shape of the figure in the vertex format, run length intermediate data that represents the shape of the figure in the run length format that indicates the presence or absence of pixels in the raster direction, and shape in the bitmap data format. There is bitmap intermediate data and the like to represent. These shape intermediate data are stored in the shape intermediate data group storage areas 17, 19, 21 of the RAM 7. The character intermediate data is data for specifying the type of font used and the character shape, and is used in the font ROM.
12 or the work memory 22 of the RAM 7 based on the data indicating the font data sent from the host computer 2 and stored in the work memory 22 or the font shape data (for example, outline data) of the font ROM 12.
It is shape intermediate data that can be easily expanded to the bitmap created in.

Each packet P _{1 to} P _n is provided for each figure or character indicated by the page description code 10 and has an identifier 2
5, color 26, position 27, pointer 28, etc.
The identifier 25 stores in what format the intermediate data indicated by the pointer 28 is stored, for example, the font ROM 1
Whether the address in 2 is specified, polygon intermediate data in the shape intermediate data group is specified, run length intermediate data is specified, or bitmap intermediate data is specified. This is the data for identifying. The color 26 is data designating a color. In the case of a color printer, the page description code 10 designating the colors of the figures and characters described by the page description code 10 is also sent. This color based on that color designation 26
To set. In the case of a mono-color printer, this area is not always necessary. Position 27 is page description code 10
The position on the page of the figure or character described by is indicated by the page description code 10 itself or is determined from the order in which the page description code 10 is sent. Pointer 28
Indicates the address of the memory in which the shape intermediate data of the figure or character indicated by this packet or the character intermediate data is stored.

In the case of this printing apparatus 1, the reception buffer 11
When the page description code 10 is stored in, the page description code 10 is sequentially analyzed and converted into intermediate data of a format suitable for the type, and the converted intermediate data corresponds to a region (band). Stored in the block. And
When the conversion for one page is completed, based on the intermediate data stored in each block, the two band buffers 23 and 24 are alternately used for each block to develop the bit map data, and the band buffers 23 and 24 are sequentially expanded. One page is output based on the bitmap data stored therein (see FIG. 4). Further, in FIG. 1, each packet memory 16, 18, 20 and each shape intermediate data group memory are stored for each block.
Although the areas 17, 19, and 21 are shown as being stored in a pair, they are not necessarily stored in such a pair. Each shape intermediate data group storage area 17, 1
9 and 21 may be allocated as one memory area in the RAM 7, and the stored shape intermediate data may be referred to by the packet of any block.
Here, what corresponds to the intermediate data storing means described in the claims is each shape intermediate data group storage area 17, 19, 2.
1, which corresponds to the second intermediate data storage means,
The packet memories 16, 18, and 20 corresponding to the bit map data storage means are the band buffers 2.
3 and 24. A packet corresponds to the instruction data.

FIG. 2 is a flow chart showing the processing procedure of the present embodiment, and shows the processing procedure for inputting the page description code 10 for one page from the host computer 2 and printing one page according to the code. . First, CPU4
In step S1, the work memory 22 of the RAM 7, the packet memories 16, 18, 20 and the shape intermediate data group storage areas 17, 19, 21 and the like are initialized. At this time,
If necessary, shape intermediate data group storage areas 17, 19,
The process of erasing the shape intermediate data stored in 21 to secure the memory area is also performed. Then, step S2
Then, the page description code 10 indicating the image information is input, and the process proceeds to step S3 to create intermediate data based on the input code data. Here, since the code data includes not only the graphic as described above but also the character and other control codes, an intermediate code suitable for those codes is created. Here, for the sake of simplicity, a case where code data representing a figure is input will be described. In this case, as the intermediate data, the graphic intermediate data representing the shape of the graphic and the packet representing the position on the page are created.

In step S4, if the intermediate data created in step S3 represents a figure, the capacity of the shape intermediate data in the created intermediate data is calculated (first calculating means), and thereafter, Go to step S5. Here, FIG. 3A illustrates a method of calculating the capacity of polygon intermediate data. Vertices 31, 32, 3 as polygons
In the case of a rectangle having 3, 34, each vertex 31, 32, 3
If the coordinates of 3 and 34 are represented by 4 bytes, then 4 points will be 4
16 bytes, which is four times the byte, is the capacity of the quadrangle intermediate data as a polygon. The characteristics of the polygonal intermediate data are as follows. That is, the data capacity does not depend on the size of the figure. Data capacity does not depend on output resolution.
The data capacity increases as the number of vertices of the figure increases.

In step S5, based on the polygon intermediate data created in step S3, the memory capacity required when this figure is converted into a bitmap and stored, that is, the capacity (B) of the bitmap intermediate data is calculated. (Second
(Calculation means), and the process proceeds to step S6. Here, FIG. 3 (b)
Describes a method of calculating the capacity of intermediate data obtained by bitmapping the quadrangle shown in FIG. In this case, a quadrangle is drawn by the output dots 41, 42, 43 of the first line, the output dots 44, 45, 46 of the second line and the output dots 47, 48, 49 of the third line. Since one output dot is 1 bit, 3 dots required for 1 line is 3 bits, but it is treated as the minimum 1 byte by the computer. Therefore, 3 lines have 3 bytes, which is 3 times 1 byte. Therefore, the capacity of the rectangular bitmap intermediate data is 3 bytes.

When the processing of step S5 is performed, if calculation is performed on the assumption that the polygonal intermediate data is expanded into the above-mentioned bitmap, the overall processing speed may be reduced. There is. Therefore, before performing the calculation based on the storage of the bitmap as described above,
First, the size of a figure (generally called a bounding box) estimated from each vertex coordinate data of polygonal intermediate data is calculated, and the above calculation is performed only for those that are smaller than a predetermined size. It is better to do so. Further, as can be seen from FIG. 3B, the data unit handled by the CPU 4 (here, the size of the figure when it is actually expanded into the band buffers 23 and 24 (9 bits shown by diagonal lines in the figure) Depending on the number of bytes, the capacity of the bitmap intermediate data becomes large. Therefore, it is necessary to change the calculation method depending on the data unit handled by the CPU 4. The characteristics of the bit-mapped intermediate data are as follows. That is, the larger the figure, the larger the data capacity. The data capacity increases as the output resolution of the printer increases. The data capacity does not depend on the number of vertices of the figure.

In step S6, the above-mentioned intermediate data capacities A and B are compared. If only the storage capacity is a problem, it may be simply determined whether or not A> B (the predetermined amount in the claims is 0). However, the processing speed may also be taken into consideration when making the determination. In that case, when the band buffers 23 and 24 are expanded as bitmap data,
The determination may be made with a difference of a predetermined amount (C) so that the bitmap intermediate data that can be processed at a higher speed than the polygonal intermediate data can be preferentially stored. That is, A> B +
C may be determined. Here, the determination result is NO, that is,
If A ≦ B, the process proceeds to step S8, YES, that is, A
If> B, the process proceeds to step S7. In step S7, the polygon intermediate data is replaced with the bitmap intermediate data, the polygon intermediate data is erased, and the process proceeds to step S8.

In step S8, the above-mentioned step S
3 or the packet corresponding to the shape intermediate data obtained in S8 is stored in at least one of the packet memories 16, 18 and 20. In this case, if the capacity (A) of the polygonal intermediate data is less than or equal to the capacity (B) of the bitmap intermediate data, this packet indicates the shape intermediate data group storage area 1
The addresses of the polygon intermediate data stored in 7, 19 and 21 are stored. When A is larger than B, the addresses are stored in the shape intermediate data group storage areas 17, 19 and 21 instead of the polygon intermediate data. The address of the intermediate bitmap data is stored. Then, it progresses to step S9.

In step S9, it is determined whether the conversion of the code data into the intermediate data has been completed for one page. If the determination result is YES, the process proceeds to step S10, and if the determination result is NO, the process returns to step S2 to repeat the process of the next code data. In step 10, the print engine is started. Then, step S11
Then, the process advances to step S21 to sequentially read the packets of the block to be printed, and based on the identifier 25 of the packet, it is determined whether the shape intermediate data indicated by this packet is polygon intermediate data. If the determination result is YES, the process proceeds to step S12, and if NO, the process proceeds to step S13.

In step S12, the polygonal intermediate data is developed into a bit map, and the band buffers 23 and 2 are output.
4 (stored in any one of 4) (first bitmap data forming means). Then, it progresses to step S14. Step S1
3, the intermediate bitmap data is copied to one of the band buffers 23 and 24 (actually, the logical sum is added to overwrite the already stored bitmap data) to represent a graphic image. It is stored as bitmap data (second bitmap forming means). Here, in this flowchart , the description of the processing of the intermediate data for the character and the control code is omitted, but the steps S11 to S13 described here are omitted.
Similarly to the above, the bitmap data is appropriately expanded or controlled based on the identifier 25 in the packet. Then, it progresses to step S14.

In step S14, it is determined whether or not all of the intermediate data in a predetermined block, to be precise, the packet has been processed. If the determination result is NO, the process returns to step S11 and is repeated. If YES, the process proceeds to step S15, and printing is performed based on the bit map data expanded in either of the band buffers 23 and 24. Here, the process of step S15 is performed as a time-divisional process such as a well-known interrupt process, and the expansion process (S11 to S13) of the next block is also performed while the process is performed. In step S16, it is determined whether or not the printing process of the block for one page is completed. If the determination result is YES, the printed paper is ejected in step S17, and then the process is ended. If the determination result is NO, the process is repeated until the intermediate data packets of all blocks are processed.

As described above, when the figure indicated by the page description code 10 is converted into intermediate data in a format that can be easily expanded into bit map data and temporarily stored, it corresponds to the figure represented by the code as appropriate. Calculate the size of the shape intermediate data,
By comparing with the capacity when it is replaced with the shape intermediate data of another format, not all are stored as the shape intermediate data representing the figure shape of the same format, but the size and shape complexity (of many Some vertices) can be stored as shape intermediate data in another format that can be stored with a smaller storage capacity. Therefore, the storage capacity for storing the intermediate data can be reduced, and if the storage capacity is the same, more intermediate data of figures can be stored. Further, a method of reducing the storage capacity of the intermediate data in this way is to expand one page on the memory virtually by the intermediate data without having a memory for expanding the bitmap data for one page at a time, and perform band processing. This is particularly effective for a printer of the type that performs printing while sequentially expanding the bitmap data in the band buffer for each block. Even if the memory has a memory for expanding the bitmap data for one page at a time, it is effective when printing a plurality of pages or converting the data into intermediate data in advance.

In the above embodiment, the packet memories 16 and 1 for storing the packet of the intermediate data in FIG.
Although 8 and 20 are shown as having a predetermined size, instead of allocating each packet memory to a separate memory area in this way, one memory area is allocated to the packet memory and Various methods are conceivable, such as inserting identifiable data between the packet and the packet of the next block. Furthermore, in the above-described embodiment, the conversion from polygonal intermediate data to bitmap intermediate data is shown, but the conversion from run length intermediate data to bitmap intermediate data can be performed in the same manner. In the case of run-length intermediate data, the capacity of the data tends to increase in the case of a figure in which printed pixels and non-printed pixels are arranged in a short cycle, and the capacity of the intermediate data can be reduced by storing it as bitmap data. . Further, conversion from run length intermediate data to polygonal intermediate data can be performed in the same manner. For example, in the case of a graphic having a long distance across the raster, the number of rasters increases, and the capacity of run-length intermediate data tends to increase. In that case, replacing with polygon intermediate data that does not depend on the number of rasters is effective in reducing the storage capacity.

[0030]

As described in detail above, the first aspect of the present invention
According to the printing apparatus of the present invention, the capacity of the intermediate data storage means of the printing apparatus can be reduced. Therefore, the cost of the printing apparatus can be reduced. Furthermore, according to the printing apparatus according to the second invention, the first
With the effect of the invention, this to increase the printing speed of the printing device
You can

Further, according to the control method of the printing apparatus according to the third invention , the storage capacity of the intermediate data can be reduced similarly to the first invention, so that the cost of the printing apparatus can be reduced. it can. Furthermore, it relates to the fourth invention .
According to the control method of the printing apparatus, together with the effects of the third invention, it is possible to increase the printing speed of the printing apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram for implementing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating the embodiment described above.

FIG. 3 is an explanatory diagram explaining an operation of the embodiment.

FIG. 4 is an explanatory diagram illustrating operations of a conventional example and the above-described embodiment.

[Explanation of symbols]

1 printing device 4 CPU 6 ROM 7 RAM 9 printing means 10 page description code 11 reception buffer 13, 14, 15 band 22 work memory 23, 24 band buffer P _{1 to} P _n packet 27 positions S 1 to S 17 steps 1 to step 17

Claims (4)

(57) [Claims] 1. Based on a page description code input from the outside
A printing device that prints with a control means and a plurality of
Data storage means and at least two band buffers
And a printing unit, and each band buffer has one area obtained by dividing one page into a predetermined number.
It has a capacity corresponding to the area, and the control means analyzes the page description code input from the outside and
First intermediate data format or second intermediate data format for each code
Select the data format with the smaller capacity in the formula and intermediate
Converted to data and stored in the intermediate data storage means
In the page description code corresponding to the converted intermediate data
Obtain instruction data that indicates the position on the page of the figure to be described.
Therefore, the instruction data is stored in association with the intermediate data.
The intermediate data stored for each page description code
Based on the position indicated by the instruction data corresponding to the data,
The bitmap data stored in the band buffer is used as the printing means.
Printing equipment characterized by printing based on data
Place 2. The printing apparatus according to claim 1, wherein the intermediate data converted in the first intermediate data format is a vertex format.
It is polygon intermediate data that represents the shape of the figure with coordinates,
Intermediate data converted in the second intermediate data format is a polygon
Bitmap intermediate data that is a bitmap of inter-data
A printing device characterized by: 3. Based on a page description code input from the outside
A printing device that prints each page by dividing it into a predetermined number of areas.
The page control code is analyzed by analyzing the page description code input from the outside.
First intermediate data format or second intermediate data format for each code
Select the data format with the smaller capacity in the formula and intermediate
Converted to data and stored, and the converted intermediate
On page figure described by the page description code that corresponds to the data
To obtain the instruction data indicating the position at
The intermediate data stored for each page description code is stored in association with the intermediate data.
Based on the position indicated by the instruction data corresponding to the data,
Bitmap data that has been expanded to map data and expanded
Is stored in association with each area and based on the bitmap data stored in association with each area.
A method for controlling a printing device, comprising: 4. A method for controlling a printing apparatus according to claim 3,
Then, the intermediate data converted by the first intermediate data format is the vertex format.
It is polygon intermediate data that represents the shape of the figure with coordinates,
Intermediate data converted in the second intermediate data format is a polygon
Bitmap intermediate data that is a bitmap of inter-data
A method for controlling a printing apparatus, comprising: