JPH08130618A - Printer and print method - Google Patents

Abstract

PURPOSE: To switch to high quality processing keeping resolution or high speed print processing with reduced resolution flexibly by discriminating whether or not a memory storing bit map data generated from intermediate data is reserved and selecting a mode with a different resolution depending on the result of discrimination. CONSTITUTION: A CPU 203a receives data from a host computer 201, generates a display list(DL) and stores the list to a DL storage section of a RAM 207. The CPU 203a discriminates whether or not a band raster storage section 213 storing bit map(BM) data is to be reserved according to a program stored in a ROM 204. When it is discriminated that no BM memory is reserved and no extension memory is connected, the resolution is decreased from 600dpi into 300dpi or the like and intermediate data are stored in the BM memory reserved at present and BM data are generated.

Description

Detailed Description of the Invention

[0001]

The present invention relates to the first data to the second data.
And a printing method for generating and printing the above data.

[0002]

2. Description of the Related Art A printing apparatus such as a laser beam printer which forms pixels by a scan process needs to generate a full raster image of a print image in a bitmap memory prior to the print process. This is because the printing device scans and prints at a constant speed when printing a page. That is, when the page printing starts, the printing process is performed at a constant speed until the page printing ends. Therefore, the entire image to be printed is converted into a raster image in the bitmap memory prior to the printing process so that the print engine does not lack data to be printed (a situation called data underflow). When the image is actually printed, the CPU in the printer monitors the bitmap memory to check whether the raster image is being supplied to the printer engine at the speed at which the printer engine prints.

In such a printing system, for example, to print a simple black-and-white image on a standard paper sheet of 8.1 / 2.times.11 inches at a low resolution such as 300 dots / inch (dpi), it is necessary to print about 1 megabyte ( Mb) bitmap memory is required. At this time, since the price of the 1 Mb memory is low, it does not matter if most of the memory is not used for a long time. The same applies when the bitmap memory is a double buffer memory, that is, a 2 Mb memory. Double buffering has a preferable property that the CPU can print the image data of the current page from another buffer while generating the image data of the next page as a raster image in one buffer. That is, according to double buffering,
The raster image data string can be continuously transferred to the print engine, and the in-page throughput can be increased without increasing the cost.

On the other hand, for example, at a resolution of 600 dpi, 300 dpi is required to store a full raster image.
4 times as much memory is required. When targeting halftones or color images, more memory is required. For example, if there are 16 gradations for each pixel in a halftone image, 4 bits are required for each pixel. It can be seen that multiplying 4 bits per pixel by 4 Mb required to store a 600 dpi raster image requires 16 Mb to store a halftone raster image. When targeting a color image, more memory is required. For example, when encoding with 8 bits for each color and 4 colors for each pixel, each pixel requires 32 bits. Multiplying 32 bits by 4 Mb of a 600 dpi raster image gives 128 to store a full color 600 dpi raster image.
Mb memory is required. The price of such a large amount of memory is not acceptable for commercial products. Also, the problem is exacerbated when using double buffering to reduce intra-page delay.

Therefore, in order to process input data having a resolution of 600 dpi using a bit map memory having a limited capacity, a method of reducing the resolution from 600 dpi to 300 dpi and generating output data in the bit map memory can be considered. .

In order to process input data having a resolution of 600 dpi so as not to cause data underflow, a method of reducing the resolution from 600 dpi to 300 dpi and generating output data in a bit map memory can be considered.

[0007]

However, in such a printing apparatus, even if the printing process can be executed with certainty, there is a problem of image deterioration of the printing result due to the resolution of 600 dpi being lowered to 300 dpi, for example.

In order to solve the above problems, the present invention provides
An object of the present invention is to provide a printing apparatus and a printing method for automatically selecting whether to reduce the resolution to perform bitmap expansion or to maintain the resolution and perform bitmap expansion according to the memory capacity that can be secured.

[0009]

A printing apparatus according to the present invention is a printing apparatus for generating and printing second data from first data, and a memory for storing the second data can be secured. A first mode for generating the second data at a first resolution or a second mode lower than the first resolution according to a determination result of the determination means. Selecting means for selecting a second mode for generating the second data at a resolution.

A printing method according to the present invention is a printing method in a printing apparatus for generating and printing second data from first data, and whether or not a memory for storing the second data can be secured. And a second resolution lower than the first resolution for generating the second data at a first resolution according to a determination step for determining And a selecting step of selecting a second mode for generating the second data.

[0011]

It is determined whether or not the memory for storing the second data generated from the first data can be secured, and according to the result of the determination, the first data to the second data can be obtained at the first resolution. Or a second mode for generating second data from the first data at a second resolution lower than the first resolution.

[0012]

First, an example of an image output unit to which the present invention is applicable will be described before describing the configuration of the present invention.

FIG. 1 is a sectional view showing an example of an image output unit to which the present invention can be applied, for example, a case of a laser beam printer.

In the figure, 100 is the LBP body,
Character information (character code) supplied from an externally connected host computer 201, form information, macro commands, etc. are input and stored, and corresponding character patterns, form patterns, etc. are created in accordance with the information. An image is formed on a recording sheet which is a recording medium. Reference numeral 112 denotes an operation panel on which switches for operation and LED displays are arranged, and 101 is a printer control unit for controlling the entire main body 100 and analyzing character information and the like supplied from a host computer. The printer control unit 101 mainly converts character information into a video signal of a corresponding character pattern and outputs it to the laser driver 102.

The laser driver 102 is the semiconductor laser 1
03 is a circuit for driving the laser light source 03, and switches on / off the laser light 104 emitted from the semiconductor laser 103 according to the input video signal. The laser beam 104 is oscillated by the rotating polygon mirror 105 in the left and right directions, and the electrostatic drum 106 is rotated.
Scan over.

As a result, an electrostatic latent image of a character pattern is formed on the electrostatic drum 106. The latent image is developed by the developing unit 107 around the electrostatic drum 106 and then transferred to the recording paper. A cut sheet is used as the recording paper, and the cut sheet recording paper is stored in a paper cassette 108 mounted on the main body 100, and is taken into the apparatus by a paper feed roller 109, a conveyance roller 110, and a conveyance roller 111, and the electrostatic drum. 106.

FIG. 8 is a block diagram for explaining the arrangement of an image processing apparatus that reduces the resolution and reliably executes the printing process.

In the figure, 201 is a host computer, which is connected to the control unit 101 via an interface connector (not shown). Control unit 10
1 is configured to receive input data including a command and a character code from the host computer 201 and print out the data. Reference numeral 203 denotes a CPU, which performs calculation / control for performing overall control of an engine unit (not shown). Reference numeral 202 denotes a reception buffer, which temporarily stores the input data including the command and the character code from the host computer 201. 204 is a program ROM
In addition, a program and the like for realizing a series of controls according to a flowchart shown in FIG. 9 described later are stored. A font ROM 206 stores a font scaler program for generating a character font pattern and an outline font. A RAM 207 is a work area or intermediate data (display list) storage unit 2 when the CPU 203 executes each program.
12, output data (bitmap data) storage unit 213
Function as An image output unit 205 outputs output data to the printer engine unit. Further, power is supplied to the control unit 101 from a power supply device (not shown). In addition, the program ROM 204 includes
As a program, four types of processing are stored: a band drawing unit 208, a display list memory management unit 209, a drawing time management unit 210, and a display list reduction unit 211.

FIG. 9 is a flow chart showing an example of the drawing process for the RAM 207 shown in FIG. In addition,
(1) to (10) show each step.

When power is supplied to the main body, the display list storage section 212 and the band raster storage section 213 are initialized and the resolution of the display list created in step (4) is set (1). The configurations of the display list storage 212 and the band raster storage unit 213 at this time will be described later.

Next, the input data is received from the host computer 201 (2), the received data is stored in the reception buffer 202, and the received reception buffer 202 is stored.
Read the data for 1 unit code from. Then, the received data is interpreted as a command (3), and a 600 dpi display list (intermediate data) is generated based on the command (4). The display list memory management unit 209 determines whether the display list memory management unit 209 can acquire the memory from the display list area storage unit 212 (5). If the memory can be acquired, the acquired display list is acquired. The display list is stored in (6). Next, the drawing time management unit 210 predicts the time required to draw the created display list in the band raster storage unit 213 and adds it to the band management table. Then, the drawing time from the display list to the band raster is stored in the band raster storage unit 21.
It is determined whether the output time from 3 to the image output unit is shorter than (7). If YES, the process returns to step (2) to wait for the next data input.

On the other hand, the drawing time added in the judgment of step (7) is changed from the band raster storage unit 213 to the image output unit 20.
If it is determined that the output time is longer than the output time to 5, the display list reduction unit 211 proceeds to step (8), where 600 in the display list already created.
The resolution of the dpi object is converted to the 300 dpi object (8), the resolution of the display list generated in step (4) is set to 300 dpi (9), the process returns to step (2) and waits for the next data input. . On the other hand, if it is determined in step (5) that the memory cannot be acquired, the process proceeds to step (8) and thereafter.

When the resolution of the 600 dpi object in the display list is converted to the 300 dpi object in step (8), it is included in the 600 dpi display list (intermediate data). For example 600
Decimate the dot pattern of dpi size to 3
Convert to a character dot pattern of 00 dpi size.

If it is determined in step (3) that the command is a paper discharge command, the display list is drawn in the band raster storage area for each band (1
0). At this time, when the display list stored in the display list storage area is 600 dpi, drawing is performed with the band raster set to 600 dpi. When the display list stored in the display list storage area is 300 dpi, the band raster is set to 300 dpi.
Draw as i. Then, the band raster for which drawing has been completed is sent to the printer engine by the image output unit 205. Here, the band raster storage unit 213 has an area for two bands, and while one band is being sent to the printer engine, drawing can be performed on the other band.

Below, referring to FIGS. 10 and 11, FIG.
The configurations of the display list storage unit 212 and the band raster storage unit 213 shown in FIG.

FIGS. 10 and 11 are schematic diagrams for explaining the configurations of the display list storage section 212 and the band raster storage section 213 shown in FIG.

In FIG. 10, 401 is a normal memory state, and 600 is stored in the display list storage area 402.
A display list of dpi is generated. Further, at the time of page discharge, the display list stored in the display list storage area 402 is drawn in the band raster storage unit 403 for each band at 600 dpi.

Numeral 404 indicates that when the display list memory management unit 209 judges that the capacity of the display list is larger than a certain capacity, or the drawing time management unit 21.
A value of 0 corresponds to the memory state when it is determined that the time for drawing the display list on the band raster is longer than a certain time.

Normal display list storage unit 402
The 600 dpi object therein becomes the display list storage unit 405 whose resolution is converted into the object of 300 dpi by the display list reduction unit 211.
Further, the resolution of the band raster storage unit 403 at the normal time is also 6
It changes from 00 dpi to 300 dpi and becomes the band raster storage unit 406.

By such resolution conversion, an empty area is created in the display list storage section 405. Also, 30
Display list drawing time of 0 dpi is 600d
Since the display time is shorter than the drawing time of the pi display list, the display list stored in the display list storage area 405, the display list stored in the band raster storage unit 405, and the display list stored in the band raster storage unit 405 are discharged at the time of page discharge. 300 in the band raster storage unit 406
The band raster already drawn can be output to the image output unit 205 while the drawing is performed as dpi.

After the latter memory state is reached, the display list generated by the display list generation processing is 300 dpi.

In FIG. 11, reference numeral 501 denotes a memory structure in a normal state, and 6 is stored in the display list storage area 502.
A display list of 00 dpi is generated. Also,
At the time of band drawing (at the time of page output), the display list stored in the display list storage area 502 is drawn in the band raster storage unit 503 as 600 dpi.

Reference numeral 504 indicates that when the display list memory management unit 209 determines that the display list capacity is larger than a certain capacity, or the drawing time management unit 21.
It is a memory state when it is determined by 1 that the time for drawing the display list on the band raster is longer than the predetermined time.

Normal display list storage unit 502
The display list reduction unit 211 converts the resolution of the 600 dpi object in the display object into a 300 dpi object, and the band raster 506 displays 300 dpi.
Drawing is performed with pi.

In this way, the display list of 600 dpi in the display list memory storage unit 502 is converted into 300 dpi, and all of them are drawn on the band raster 506.

However, the initial band raster storage unit 506
If the raster area for one page cannot be secured, the empty area that can be secured by converting the display list storage area 502 to a low resolution or the display list in the display list storage unit 505 is a band raster 5.
The empty area that can be secured by completing the drawing in 06 is used.

After the latter memory configuration, the display list 300 dpi is generated by the display list generation processing, and the generated display list is stored in the display list storage area 505.

Also, after the latter memory configuration is achieved, the created 300 dpi display list may be directly drawn in the band raster storage unit 506.

The format of the display list and the raster expansion state based on the display list will be described below with reference to FIGS. 12 and 13.

FIG. 12 is a diagram showing an example of a display list in this type of image processing apparatus. The display list (intermediate data) is a data group in which input data (printer language including a character code and a control code) input from a host computer or the like is put into a format that can be easily converted into bitmap data by a printing device.

In the figure, a band table 1201 is used to divide a page into a plurality of bands and manage drawing objects for each band. A drawing unit (application) 1202 is for managing the actual print position of the drawing object. Reference numeral 1204 is a drawing object (bitmap, font). 1203
Is an object table for managing drawing objects. What is a display list?
It means a data list consisting of four.

The band table 1201 has an application link to the band, and the application 1
Reference numeral 202 denotes a pointer to the next application, print positions X and Y in the band, an object number of the drawing object, and a scan line offset from the head of the drawing object to the print start position in the band. Has a pointer to the drawing object, and the drawing object 1204 has the width, height and drawing bitmap of the drawing object.

FIG. 13 is a schematic diagram showing an example of rasterization development based on the display list shown in FIG.

As shown in this figure, an application is developed for each band and rasterized drawing is performed, thereby drawing in the raster memory and processing the output image.

FIG. 2 is a block diagram for explaining the arrangement of an image processing apparatus that reliably executes print processing without lowering the resolution. The same components as those in FIG. 8 are designated by the same reference numerals.

In the figure, 203a is a CPU, which controls drawing expansion in accordance with a procedure shown in FIG. 4 which will be described later. FIG.
2 is a flowchart showing an example of an image processing procedure in the image processing apparatus of FIG. 2 for surely executing print processing without lowering resolution, and (1) to (9) show respective steps.

When power is supplied to the main body, the display list storage section 212 and the band raster storage section 213 are initialized and the resolution of the display list created in step (4) is set (1). At this time, the configurations of the display list storage unit 212 and the band raster storage unit 213 will be described later.

Next, data is received from the host computer 201 (2), the received data is stored in the reception buffer 202, and one unit code of data is read from the stored reception buffer 202. Then, the received data is interpreted as a command (3), and a 600 dpi display list is generated based on the command (4). The display list memory management unit 209 determines whether the display list memory management unit 209 can acquire the memory from the display list storage unit 212 (5). The display list is stored (6). Next, the drawing time management unit 210 predicts the time required to draw the created display list in the band raster storage unit 213 and adds it to the band management table. Then, it is determined whether the drawing time from the display to the band raster is shorter than the output time from the band raster storage unit 213 to the image output unit (7). If YES, the process returns to step (2) to input the next data. To wait.

On the other hand, the drawing time added in the judgment of step (7) is changed from the band raster storage unit 213 to the image output unit 20.
If it is determined that the time is longer than the output time to 5, the process proceeds to step (8), and the band drawing unit 208 stores the 600 dpi object in the already created display list in the band raster storage memory at 600 dpi without lowering the resolution. Draw one page in 606 (8),
Return to step (2) to wait for the next data input. On the other hand, if it is determined in step (5) that the memory cannot be acquired, the process proceeds to step (8) and thereafter. A detailed description of step (8) will be given later with reference to FIG.

If it is determined in step (3) that the command is a paper discharge command, the display list is drawn for each band in the band raster storage area (9).

FIG. 3 shows the first part of the RAM 207 shown in FIG.
3 is a schematic diagram illustrating a memory map of FIG.

Reference numeral 601 denotes a normal memory state, and a display list of 600 dpi is generated in the display list storage area 602. Further, at the time of band drawing (at the time of page output), the display list stored in the display list storage area 602 is drawn at 600 dpi in the band raster storage unit 603.

Reference numeral 604 denotes a case where the display list memory management unit 209 determines that the capacity of the display list is larger than a certain capacity, or the drawing time management unit 2
This is a memory state when it is determined by 10 that the time for drawing the display list on the band raster is longer than a certain time.

Normal display list storage unit 602
The 600 dpi object inside is the band raster 6 in sequence.
The image is drawn at 06 at 600 dpi. In this way,
600 dp in display list memory storage unit 602
The display list of i is not converted to low resolution, and all (one page) band rasters 606 are drawn.

However, the initial band raster storage unit 606
If the raster area for one page cannot be secured, a free area that can be secured by drawing the display list in the display list storage unit 605 in the band raster storage memory 606 is used.

For example, in the band raster storage memory 606, a vacant area of the shaded area generated by converting the display list in the shaded area of the display list storage memory 602 into bitmap data and storing it in the band memory storage memory 603 in FIG. Allocate and secure the band raster storage memory 606 of the one-page pull memory. That is, the above process is repeated to always secure the band raster storage memory 606 of one page full memory.

Further, even after the latter memory state (in the memory saving mode), the display list generated by the display list generation processing is 600 dpi, and the generated display list is stored in the display list storage area 605. To be done.

Further, after the latter memory state is reached, the created 600 dpi display list may be directly drawn in the band raster storage unit 606.

Further, here, if the display list has a capacity larger than a certain capacity, or if the display list is drawn on the band raster for a longer time than a certain time, all display lists are drawn on the band raster. However, when the sum of the capacities of the display list storage unit is small, the display list memory management unit 209 determines that the display list capacity is larger than a certain capacity, or the drawing time management unit 2
When it is determined by 10 that the time for drawing the display list on the band raster is longer than a certain time,
The display list reduction unit 211 performs low resolution conversion from 600 dpi to 300 dpi, the low resolution display list stored in the display list storage area is drawn as 300 dpi in the band raster storage unit, and the capacity of the display list storage unit 212 is reduced. If the sum of the capacity of the band raster storage area and the capacity of the band raster storage is large, or if the capacity of the display list is larger than a certain capacity, or if the time to draw the display list on the band raster is longer than a certain time, all display lists are displayed. It is also possible to add an automatic switching function depending on the memory capacity of the bitmap memory, such as drawing on a band raster without lowering the resolution.

FIG. 15 is a flow chart showing the operation of this automatic switching function. The program shown in this flowchart is stored in the program ROM 204 and is executed by the CPU 203.

In step (1), the CPU 203 determines whether or not the bit map memory (band raster storage unit) required for the current RAM 207 can be secured. For example, it is determined whether or not a bitmap memory that can store bit map data for the designated paper size can be secured. When it is determined that the bit map memory can be secured in step (1), the bit map memory required in step (2) is secured, and the resolution is maintained as described with reference to FIGS. 4 and 14 in step (3). The intermediate data is drawn in the secured bitmap memory to generate bitmap data.

In step (1), the current RAM 20
If it is determined that the bitmap memory (band raster storage unit) required for 7 cannot be secured, in step (4),
Determine whether or not an additional memory (not shown) is connected,
When it is determined that the connection is established, the process of step (2) is executed. If it is determined in step (4) that the memory has not been added, as described with reference to FIG. 9,
The resolution is reduced from 600 dpi to 300 dpi, for example, and intermediate data is drawn in a bitmap memory that can be currently secured to generate bitmap data. After that, the generated bitmap data is output and printed via the image output unit 205.

Therefore, depending on whether or not the bitmap memory can be secured, the first mode for maintaining the resolution and generating the bitmap data and the second mode for reducing the resolution to generate the bitmap data are automatically switched. can do.

FIG. 5 shows the second RAM 207 shown in FIG.
3 is a schematic diagram illustrating a memory map of FIG.

Reference numeral 701 denotes a normal memory state, and a display list of 600 dpi is generated in the display list storage area 702. Further, at the time of band drawing (at the time of page output), the display list stored in the display list storage area 702 is drawn at 600 dpi in the band raster storage unit 703.

Reference numeral 704 indicates that when the display list memory management unit 209 determines that the display list capacity is larger than a certain capacity, or the drawing time management unit 21.
It is a memory state when it is determined that the time for drawing the display list on the band raster is longer than a certain time by 0.

Normal display list storage unit 702
The 600 dpi object inside is the band raster 7 in sequence.
Drawing is performed at 600 dpi without reducing the resolution to 06. In this way, the display list memory storage unit 7
The display list of 600 dpi in 02 is all (one page) band raster 706 without low resolution conversion.
Is drawn. Then, the band raster is compressed and then stored.

In this way, the CPU 203a draws the display list on the band raster when the capacity of the display list is larger than the fixed capacity or when the time for drawing the display list on the band raster is longer than the fixed time. However, since the drawn band raster is compressed and stored, the drawing control means uses the band raster even if the display list has a capacity larger than a certain capacity or if the time to draw the display list on the band raster is longer than a certain time. It is possible to reliably prevent the resolution of the rasterized output image from being converted to a low resolution.

However, the initial band raster storage unit 706
If the raster area for one page cannot be secured, a free area that can be secured by drawing the display list in the display list storage unit 705 on the band raster 706 is used.

Even after the latter memory state is reached, the display list generated by the display list generation processing is 600 dpi, and the generated display list is stored in the display list storage area 705. Further, after the latter memory state is reached, the created display list of 600 dpi may be directly drawn in the band raster storage unit 706.

FIG. 14 is a flow chart for explaining step (8) in the flow chart of FIG. 4 in detail.

At step 8-1, the CPU 203 determines whether or not the band area including the object to be drawn has already been drawn. For example, when the upper part of the character pattern B shown in FIG. 13 is drawn in the 0 band area, it is determined whether the 0 band area has been drawn. If it is determined in step 8-1 that the band area including the object to be drawn has been drawn, the compressed data of the band area is expanded in step 8-2, and the expanded band area of the band area is expanded in step 8-3. Draws an object for drawing on bitmap data (expands bitmap). For example, in order to draw the upper part of the character pattern B shown in FIG. 13 in the 0 band area, the upper part of the character pattern A is drawn and the compressed data of the 0 band area that has been compressed is expanded and obtained. The upper part of the character pattern B is drawn in the bitmap data of the 0 band area.

When the CPU 203 determines in step 8-1 that the band area including the object to be drawn has not been drawn, the object is drawn in step 8-3, compressed in step 8-4, and then step 8 At -5, it is stored in the band raster storage unit 213. And step 8
In step -6, it is determined whether or not all the objects in the display list have been drawn on the band raster for one page. If it is determined that one page has been drawn, the process returns to step (2), and if it is determined that one page has not been drawn, step 8 Return to -1 and repeat the above-mentioned processing.

FIG. 6 shows a third RAM 207 shown in FIG.
3 is a schematic diagram illustrating a memory map of FIG.

Reference numeral 801 indicates a normal memory state, and a display list of 600 dpi is generated in the display list storage area 802. Also, when drawing a band (when outputting a page), a display list storage area 802
The display list stored in (1) is drawn in the band raster storage unit 803 at 600 dpi.

Reference numeral 804 denotes a case where the display list memory management unit 209 determines that the display list capacity is larger than a certain capacity, or the drawing time management unit 21.
This is a memory configuration in the case where it is determined that the time for drawing the display list on the band raster is longer than a certain time by 0. Normal display list storage unit 802
Of the 600 dpi objects, the display list reducing unit 211 recreates 300 dpi objects, and the band raster 806 is rendered at 300 dpi. In this way, the display list of 600 dpi in the display list memory storage unit 802 is regenerated to 300 dpi, and all band rasters 80 are displayed.
Drawing is performed at 6.

In step (8) of FIG. 9, the 600 dpi object in the display list is changed to 300 d.
When converting the resolution to a pi object, 600 dp
For example, the character dot pattern of 600 dpi size included in the display list (intermediate data) of i is thinned and converted into the character dot pattern of 300 dpi size, so that the image deteriorates. The regeneration processing described above is to generate a character pattern of 300 dpi size, which is the same as the character pattern of 600 dpi object, for example, 600 dpi size, using a font scaler (program) in the font ROM 206.
This will increase the resolution from 600 dpi to 300 dpi.
Even if it is dropped to, the new character pattern of 300 dpi size is generated without thinning out the character pattern in the display list, and thus high-quality output data of 300 dpi can be generated and printed.

Therefore, the display list storage unit 802
Information such as a rescalable font ID and character code is stored in advance in the font object in the CPU.
203 is added. Then, the CPU 203 generates and prints high-quality 300 dpi output data (bitmap data) based on this information.

As described above, when the display list has a capacity larger than a certain capacity or when the time for drawing the display list on the band raster is longer than a certain time, the CPU 203a has a low resolution based on the information of the display list. Since the display list is regenerated and stored in the display list storage unit 212, it is possible to minimize image deterioration.

However, the initial band raster storage unit 806
When the raster area for one page cannot be secured, a free area that can be secured by regenerating the display list in the display list storage area 802 at a low resolution, or the display list in the display list storage unit 805 as the band raster 806. Use the free space that can be secured by finishing drawing.

After the latter memory state is reached, the display list generated by the display list generation processing is 300 dpi, and the generated display list is stored in the display list storage area 805.

Furthermore, after the latter memory state is reached,
The created display list of 300 dpi may be directly drawn in the band raster storage unit 806.

FIG. 7 shows a fourth block of the RAM 207 shown in FIG.
3 is a schematic diagram illustrating a memory map of FIG.

Reference numeral 901 denotes a memory state, and a display list of 600 dpi is generated in the display list storage area 902. If the band to which the display list belongs is band 1 or band 2, the band is drawn by the band drawing unit and stored in the band raster storage unit 903. If the band to which the display list belongs is other than band 1 or band 2, the band is stored in the display list storage area 902. Then, at the time of band drawing (at the time of page output), if the band 1 or the band 2, the image output unit 2 directly from the band raster storage unit 903.
The image is sent to 05. If band 1 or band 2
Otherwise, the display list stored in the display list storage area 902 is drawn in the band raster storage unit 903 as 600 dpi, and then the image is sent to the image output unit 205.

As described above, the CPU 203a draws and stores an arbitrary band in the display list on the band raster, and therefore it is possible to reduce the frequency of causing low resolution.

In the above embodiments, the laser beam printer is shown as an example of the image output unit 205 applicable to the present invention, but the present invention can be applied to a printer employing another printing method, for example, an ink jet printer. It goes without saying that it can be applied.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0088]

As described above, according to the present invention, the first
It is determined whether or not the memory for storing the second data generated from the above data can be secured, and according to the determination result,
A first mode for generating second data from first data at a first resolution or a second mode for generating second data from first data at a second resolution lower than the first resolution Since the automatic selection is performed, there is an excellent effect that it is possible to flexibly switch between high-quality printing processing in which resolution is maintained and high-speed printing processing in which resolution is reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a printing apparatus to which the present invention can be applied.

FIG. 2 is a block diagram illustrating a configuration of a printing apparatus according to an exemplary embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a first memory map of the RAM shown in FIG.

FIG. 4 is a flowchart showing an example of a drawing development processing procedure in the printing apparatus according to the present invention.

FIG. 5 is a schematic diagram illustrating a second memory map of the RAM shown in FIG.

FIG. 6 is a schematic diagram illustrating a third memory map of the RAM shown in FIG.

FIG. 7 is a schematic diagram illustrating a fourth memory map of the RAM shown in FIG.

FIG. 8 is a block diagram illustrating a configuration of a printing apparatus according to another embodiment.

9 is a flowchart showing an example of drawing processing for the RAM shown in FIG.

FIG. 10 is a schematic diagram illustrating a configuration of a display list and a band raster storage unit illustrated in FIG.

11 is a schematic diagram illustrating the configuration of the display list and band raster storage unit illustrated in FIG.

FIG. 12 is a diagram showing an example of a display list (intermediate data).

13 is a schematic diagram showing an example of rasterization development based on the display list shown in FIG.

14 is a step (8) of the flowchart shown in FIG.
2 is a flowchart showing in detail.

FIG. 15 is a flowchart showing an automatic switching function.

[Explanation of symbols]

201 host computer 202 consultation buffer 203a CPU 204 program ROM 205 image output unit 206 font ROM 207 RAM 208 band drawing unit 209 display list memory management unit 210 drawing time management unit 211 display list reduction unit 212 display list storage unit (intermediate data storage unit) ) 213 band raster storage unit (bitmap data storage unit)

Claims (18)

[Claims] 1. A printing device for generating and printing second data from first data, comprising: a judgment means for judging whether or not a memory for storing the second data can be secured; A first mode for generating the second data at a first resolution or a second mode for generating the second data at a second resolution lower than the first resolution according to the determination result of the means; And a selecting means for selecting the mode. 2. The print according to claim 1, wherein the first data is intermediate data obtained by processing data input from an information processing device so that the second data can be easily generated. apparatus. 3. The printing apparatus according to claim 1, wherein the second data is bitmap data. 4. The printing apparatus according to claim 1, wherein the memory is a bitmap memory. 5. The printing apparatus according to claim 1, wherein the determination unit determines whether or not a memory area for storing the second data can be secured in a memory in the printing apparatus. 6. The determination unit according to claim 1, wherein the determination unit determines whether or not a memory area for storing the second data can be secured by using a memory added to the printing apparatus. Printing device. 7. The printing apparatus according to claim 1, wherein the second data is compressed. 8. When the second data is generated at a second resolution lower than the first resolution, the first data is added to the first data so that the character information included in the first data can be regenerated. The printing apparatus according to claim 1, wherein additional information is added. 9. The printing apparatus according to claim 1, wherein the second data is generated from the first data of an arbitrary band area in the first data. 10. A printing method in a printing apparatus for generating and printing second data from the first data, the judgment step of judging whether or not a memory for storing the second data can be secured. And a second mode in which the second data is generated in a first mode in which the second data is generated in a first resolution or in a second resolution lower than the first resolution according to the determination result in the determination step. And a selection step of selecting the second mode to be generated. 11. The print according to claim 10, wherein the first data is intermediate data obtained by processing data input from an information processing device so that the second data can be easily generated. Method. 12. The printing method according to claim 10, wherein the second data is bitmap data. 13. The printing method according to claim 10, wherein the memory is a bitmap memory. 14. The printing method according to claim 10, wherein the determining step determines whether or not a memory area for storing the second data can be secured in a memory in the printing device. 15. The method according to claim 10, wherein the determining step determines whether or not a memory area for storing the second data can be secured by using a memory added to the printing device. Printing method. 16. The printing method according to claim 10, wherein the second data is compressed. 17. When the second data is generated at a second resolution lower than the first resolution, the first data is added to the first data so that the character information included in the first data can be regenerated. The additional information is added, wherein the additional information is added.
The printing method described in 0. 18. The printing method according to claim 10, wherein the second data is generated from the first data of an arbitrary band area in the first data.