JP2000181644A - Image processing apparatus, control method thereof, printing apparatus and recording medium - Google Patents

Abstract

(57) [Problem] To provide an image processing apparatus and a printer capable of processing a large amount of data without significantly increasing the capacity of a RAM and having a high processing speed. In an image processing apparatus of a printer, when a work area is insufficient, a memory management unit (20) operates in an SDRAM.
The program area P set to 10 is released, and the module D copied there changes the logical address conversion destination of the CPU so that the module D can be executed by the ROM 7. As a result, the work area increases, so even when the amount of data to be handled becomes enormous, such as when performing high-resolution full-color printing, the work area necessary for data storage is reliably secured by the SDRAM 10 having a relatively small capacity. it can. Therefore, a large amount of data can be processed without greatly increasing the capacity of the RAM. In addition, since the access speed to data can be increased, high-speed data processing can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus and a control method capable of generating and outputting drawing data based on input data.

[0002]

2. Description of the Related Art In an image processing apparatus mounted on a printing apparatus such as a page printer (laser printer) for printing data in units of a page at a time, a part of an execution program of a CPU stored in a ROM is accessed at an access speed. Copy to a fast RAM and execute the program on the RAM in many cases. According to such a method, the execution program is defined as R
Since the data can be executed by the RAM which is faster than the OM, the data processing speed is increased and the printing time can be reduced.

[0003]

As the resolution and the full color are advanced, the amount of data handled by the printer is increasing. At the same time, it is also required to improve the processing speed of the printer. To improve the processing speed of the CPU, there is a method of copying a program to the RAM and executing the program as described above. It is desirable to copy and execute as many programs as possible in the RAM.

On the other hand, when a high-resolution color image is to be printed, input data transmitted from a personal computer as a host computer, an intermediate code obtained by processing the input data,
Furthermore, the amount of drawing data to be output to the printing mechanism is extremely large. Considering that these data are compressed and stored in the RAM, a RAM having a large storage capacity is required.

Therefore, in order to realize a printer capable of handling such a huge amount of data and having a high execution speed, both a program area for copying a program and a work area for storing data are sufficiently provided. Requires a large-capacity RAM that can be secured. However, since such a large-capacity RAM is expensive, it causes an increase in the cost of the printer.

In recent years, SDRAMs with a high access speed have been used for printers, but the cost per storage capacity of SDRAMs is high. Therefore, large-capacity S
The adoption of DRAM increases the cost of the printer. In addition, the use of a CPU with a built-in DRAM in a printer is being studied.
Since it is built into the U, it is the best in terms of access speed, but it is difficult to increase the capacity of this DRAM with current technology, and the cost is high.

Furthermore, even a printer capable of high-resolution color printing does not always handle such a large amount of data, but may handle a small amount of data, such as low-resolution printing or monochrome printing. For this reason, even if a large-capacity RAM is prepared, when printing with a small amount of data, R
The use efficiency of AM is reduced.

Accordingly, in the present invention, by increasing the efficiency of use of the RAM, a large amount of data can be handled without using a huge amount of RAM, and an image processing apparatus having a high processing speed and its control. It is intended to provide a way. By incorporating the image processing apparatus of the present invention into a printing apparatus, it is an object to provide a low-cost printing apparatus capable of performing high-resolution full-color printing and performing high-speed printing. .

[0009]

Therefore, according to the present invention, a program area is set in addition to a work area in a high-speed second memory such as a RAM, and a program is copied and executed in this program area. Is faster. On the other hand, when the work area is insufficient, such as a high-resolution color image, a large amount of data can be obtained by reducing the program area to increase the work area and executing the program on the first memory of the copy source. Can be processed.

That is, an image processing apparatus according to the present invention is an image processing apparatus capable of generating and outputting drawing data based on input data, comprising: a CPU; a first memory capable of storing an execution program of the CPU; A second memory which is a work area of the CPU and is faster than the first memory capable of input / output; and a memory management means capable of converting a logical address of the CPU into a physical address including addresses of the first and second memories. The memory management means sets a program area in which at least a part of the execution program can be copied and a work area in which image data including drawing data can be stored in the second memory, and copies the program data to the program area. For the program, the logical address of the CPU is
And a setting function for converting to a memory address of the memory, and when the work area is insufficient, at least a part of the program area is released.
And a function of converting the logical address of the first memory into an address of the first memory.

Further, according to the control method of the image processing apparatus of the present invention, a program area capable of copying at least a part of an execution program and a work area capable of storing image data including drawing data are set in a second memory. For the program copied to the program area, a setting step of converting a logical address of the CPU into an address of the second memory, an image processing step of generating and outputting image data based on input data, When the area is insufficient, at least a part of the program area is released, and the program of the released part is executed by the CPU.
And converting the logical address to the address of the first memory.

In the image processing apparatus and its control method according to the present invention, a program area is set in a high-speed second memory such as a RAM, and the program is copied and executed in that area. Processing can be performed. On the other hand, when high-resolution image data is processed and the work area becomes insufficient, a part or all of the program area is released to increase the work area. Therefore, even when a large amount of data needs to be processed, it can sufficiently cope with it. Further, since the program is stored in the first memory even if the program area of the second memory is released, by converting the logical address of the CPU to the address of the first memory, the No problem.

Further, since a large amount of data is processed, the frequency of accessing the data is higher than the frequency of accessing the program. Therefore, by setting a sufficient work area in the high-speed second memory, a large amount of data can be accessed at a high speed even if the speed of accessing the program is slightly reduced. As a result, the data processing time is reduced. Can be shortened. Of course, there is also an effect that a large amount of data can be handled with a limited memory capacity.

When the data amount is not so large as in the case of low resolution or monochrome, the access speed to the program is a factor for shortening the processing time, and in the image processing apparatus and control method of the present invention, in such a situation, Since a sufficient program area can be set in the high-speed second memory, the processing speed can be increased. On the other hand, when the data amount is very large, such as a high-resolution or multi-tone color image, the access speed to the data is an important factor for reducing the processing time. In the image processing apparatus and the control method of the present invention, a sufficient work area can be set in the high-speed second memory, so that the processing speed is high even when processing a large amount of data. Since the above-mentioned state can be changed by the shortage of the work area, the utilization efficiency of the second memory can be increased. Therefore, since the capacity of the second memory does not need to be greatly increased, an image processing apparatus capable of processing a large amount of data at high speed can be provided at low cost. Further, by processing data for printing by the image processing apparatus of the present invention, it is possible to provide a printing apparatus capable of processing a color image having a large amount of data at high speed and without fail.

When the setting of the work area and the program area is changed due to the shortage of the work area, it is desirable to perform the conversion process of the data having the shortage of the work area again. By performing the conversion process again, troubles such as data loss can be reliably prevented.

As a combination of the first and second memories, a ROM and a RAM connected to the same or different bus as the CPU are generally used. Further, it is of course possible to use a higher-speed memory such as an SDRAM or a RAM built in a CPU as the second memory. In particular, such a high-speed RAM is expensive, but according to the image processing apparatus and the control method of the present invention, the memory capacity can be used very efficiently, so that the image processing apparatus capable of high-speed processing at low cost can be used. And a printing device.

The above-described control method uses a ROM or a floppy (registered trademark) which can be read by an image processing apparatus having an instruction capable of executing a process corresponding to each process.
It can be recorded on a recording medium such as a disk and provided. Further, it is of course possible to supply the program to the user via a computer network and record the program on a recording medium of a personal computer or an image processing apparatus on the user side for use.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic hardware configuration of a printer 1 according to the present invention. In the printer 1 of the present embodiment, a process of generating drawing data φ2 based on the input data φ1 received from the host computer by the image processing device 3 is executed, and the drawing data φ2 is sent to the printing mechanism 2 and printed.

The image processing apparatus 3 of the present embodiment includes a CPU 6, an SDRAM 10 serving as a work area of the CPU 6, and a memory controller 9.
Connected by Further, the memory controller 9
Is connected to an external bus 8. The external bus 8 has an input interface circuit 4 for receiving input data φ1 sent from a host computer, a ROM 5 storing an initial setting program (IPL) 5a, CPU6
The ROM 7 storing the execution program 7a is connected. In this example, the ROM 7 is a first memory. Further, the external bus 8 has a video interface circuit 13 for transferring the drawing data φ2 to the printing mechanism 2.
Is connected.

In this example, an execution program 7a of the CPU 6 is stored in a ROM 7 serving as a first memory.
This execution program 7a is composed of a plurality of modules. In this example, a module for converting the received input data φ1 into an intermediate code by processing the input data φ1, a module for converting the intermediate code into binarized drawing data φ2 printable by the printing mechanism 2, and the like Execute the four modules A, B, C, and D of the execution program 7a
The description is provided assuming that is provided.

Further, in the printer 1 of this embodiment, the ROM 7
A part or all of the execution program 7a stored in the SDRAM 10 is copied to the high-speed SDRAM 10 and executed. Therefore, in this example, the SDRAM
10 is a second memory.

For this reason, the CPU 6 converts the logical address into a physical address of the high-speed SDRAM 10 as the second memory, or converts the logical address into a physical address of the ROM 7 as the low-speed first memory. CPU6
And a memory management unit (MMU) 12 having a function of managing the conversion destination of the logical address.
The MMU 12 appropriately changes the destination of the logical address conversion of the CPU 6 so that the ROM 7 or the SDRA
The program can be executed in M10.

FIGS. 2 and 3 show schematic functions of the image processing apparatus 3 and control operations of the image processing apparatus 3. First, as shown in FIG. 2, at power-on or reset, the setting function 21 of the memory management unit 20 sets the work area W and the program area P in the SDRAM 10, and the copy function 24 sets the program area of the ROM 7
Modules C and D are copied to program area P. Then, according to the instruction of the setting function 21 of the memory management unit 20, the MMU 12
Logical addresses of modules A and B are ROM
7 and the logical addresses of the modules C and D are allocated to the physical addresses P1 and P2 of the modules C and D copied to the SDRAM 10.

The function of the memory management unit 20 is realized by using the function of the CPU 6. More specifically, the function of the memory management unit 20 is realized by the CPU 6 executing the IPL 5 a stored in the ROM 5.

In the work area W of the SDRAM 10, a work area W1 for storing drawing data and a work area W2 for storing intermediate codes are secured. The intermediate code is data obtained by interpreting the received input data φ1 by a language processing program describing the input data φ1. Then, binarized drawing data is generated by further processing the language-processed intermediate code. If the printer 1 of this example is a page printer such as a laser printer, one page of data is prepared for the intermediate code and the drawing data, so that the work area W also has a corresponding capacity. Then, when one page of data of the intermediate code and the drawing data is transferred to the printing mechanism 2 via the video interface circuit 13, the next data is generated.

In the state shown in FIG. 2, a frequently accessed program module such as a language processing module is copied to the SDRAM 10 at high speed.
A program can be executed by accessing the DRAM 10. Therefore, language processing, drawing processing, and the like can be executed at high speed.

FIG. 3 shows a state when print data of a multi-gradation, high-resolution color image is input as input data φ1. Since the amount of such print data is enormous, the amount of intermediate code and drawing data is also large. Therefore, even when the intermediate code can be stored in the work area W, the capacity of the work area may be insufficient to store the drawing data. At this time, first, in the memory management unit 20, the memory shortage detection unit 25 detects a memory shortage. According to a signal from the memory shortage detection unit 25,
The change unit 22 of the memory management unit 20 releases a part of the program area P and increases the capacity of the work area W. In FIG.
The area of the module D is opened to increase the capacity of the drawing data W1. Then, the address of the program module D in the logical address space 30 of the CPU is converted to the physical address of the ROM 7 by the MMU 12. Therefore, a memory capacity that is insufficient for the drawing data is secured, and the program module D is set to be executable in the ROM 7.

Further, when the memory shortage detecting unit 25 detects the memory shortage, the job management unit 26 managing the job in the CPU 6 converts the job in which the memory shortage occurs, in this example, from the intermediate code to the drawing data. Redo the conversion process from the beginning. Therefore, the printer 1 of the present embodiment can secure a sufficient memory capacity for storing data by opening the program area and increasing the work area even if the high-speed SDRAM 10 has a shortage of memory capacity. Therefore, it is possible to continue the process of converting the intermediate code into the drawing data using the SDRAM 10 as the data storage destination.

This will be described in more detail with reference to the flowcharts shown in FIGS. FIG. 4 is a flowchart showing the control operation of the image processing apparatus when the power is turned on.
9 is a flowchart showing a process for generating drawing data.

First, when the power is turned on, when the power is turned on in step ST1, the IPL 5a of the ROM 5 is loaded into the CPU 6, and the hardware such as the interface circuit 4 is initialized. Further, step ST
2, the program area P and the work area W
The setting is made in the DRAM 10, and the modules C and D are copied to the program area P in step ST3. Then, the modules A to D in the logical address space 30
Of the logical addresses of the modules A and B are set to the physical addresses of the ROM 7, and the logical addresses of the modules C and D are set to the physical addresses of the SDRAM 10.

With these settings, the modules C and D are executed by the SDRAM 10, so that the image processing is performed at a high speed and the printing speed is improved.

The printing process is performed as shown in FIG. First, in step ST11, input data φ
When the input data φ1 is received while waiting for the transmission of “1”, they are accumulated in the reception buffer set in the work area W of the SDRAM 10 or the like. Next, step S
At T12, the language processing module is executed in the CPU 6, and the input data φ1 is interpreted. The result is stored in the intermediate code area W2 of the work area W of the SDRAM 10 as an intermediate code. Next, in step ST13, the drawing module is executed by the CPU 6, the intermediate code is read from the work area W, and converted into drawing data. The converted drawing data is stored in the drawing data area W1 of the work area W in step ST14. Then, in step ST16, the conversion process is repeated until the drawing data for one page is accumulated.

On the other hand, if a shortage of memory in the work area occurs in step ST15 during the processing of step ST14 in which the data is converted into drawing data and output, the processing proceeds to step ST14.
Is stopped, and the routine goes to Step ST18.

In step ST18, as shown in FIG. 3, a part of the program area P of the SDRAM 10 is released, and the work area W is increased. And step ST
Regarding the program module D deleted from the SDRAM 10 at 19, the conversion destination of the logical address 30 of the CPU is changed to the ROM 7. Then, the process returns to step ST13, and the conversion process to the drawing data is executed again.

When the conversion process of step ST14 is re-executed, if the work area W has a sufficient capacity, step ST14 is executed until one page of drawing data is accumulated, and one page of data is accumulated. Then, in step ST17, the drawing data is sent to the printing mechanism and printed. If a memory shortage occurs again in step ST15 while step ST14 is being re-executed, the process proceeds to step ST18 again, where the program area P is released and the capacity of the work area W is further increased.

As described above, in the printer 1 of this embodiment, the SD
A work area W and a program area P are set in the RAM 10, and the program copied in the program area can be executed at a high speed by executing the program.
At the same time, when a large amount of data is handled, such as when it is necessary to process a high-resolution or multi-gradation color image, and a memory shortage occurs in the work area of the SDRAM 10, the program area P is released and the work area W is released. As a result, a large amount of data can be stored in the SDRAM 10. Therefore, SD for the amount of data to be processed
If there is room in the RAM 10, the program can be copied to that area to speed up the processing. On the other hand, if there is no room in the SDRAM 10 with such a setting, a large amount of data can be stored in the SDRAM 10 by releasing the program area.

For this reason, the SDRAM 10 can be used very efficiently according to the amount of data to be processed by the printer 1, and a printer capable of printing at a high speed and simultaneously printing a large amount of data can be performed smoothly. Can be provided. In addition, SDR due to lack of memory
Since the setting of the capacity of the AM 10 is automatically changed, it is not necessary to determine in advance whether there is a possibility that a memory shortage will occur. Therefore, it is possible to deal with unnecessary overhead that always considers whether or not a memory shortage occurs, and without complicating a program module for converting data.

In the image processing apparatus 3 of this embodiment, the ROM
7, an executable program is stored in an uncompressed and executable state, and can be executed by the ROM 7 when the capacity of the SDRAM 10 is insufficient. R
Since the access speed of the OM 7 is lower than that of the SDRAM 10, the execution speed of the program is lower. However, when handling a large amount of data such as a high-resolution or multi-gradation color image, the frequency of accessing the data is higher than the frequency of accessing the program.
For this reason, in such a situation, a higher-speed memory (SDR
AM) It is more effective to set a sufficient work area to increase the processing speed. Therefore, the printer 1 of this example is a printer having a high processing speed even when the data amount is large as well as when the data amount is small.

Further, the printer 1 according to the present embodiment has an SDRAM
10 can always keep the usage efficiency high, so that the amount of data that can be processed and the processing speed of the
May have a small capacity. Although the SDRAM is faster but more expensive than a conventional DRAM, the printer 1 of the present embodiment can provide a low-cost, high-performance printer by using the SDRAM efficiently.

In the printer 1 of this embodiment, when a memory shortage occurs, the process of converting the held intermediate code into drawing data is performed again. Intermediate code is 1
Since the conversion of pages is retained until the conversion is completed without error,
Such processing is possible. Of course, the conversion process may be re-executed from the data for which the memory shortage has occurred.However, there is a possibility that the data for which the memory shortage has occurred is lost, or the data may be redundantly converted. Processing time and programs may be expended to avoid On the other hand, such troubles can be prevented before starting the conversion process from the beginning, and the reliability is high because the programming is simple.

In this embodiment, the processing for converting the intermediate code into the drawing data is described as an example. However, the same processing can be performed even if a memory shortage occurs while receiving the input data. is there. However, the shortage of memory is most likely to occur in the process of converting to the drawing data immediately before sending the data to the printing mechanism and storing it. Therefore, it is desirable to ensure that the process described above is performed in this process.

The memory in which the program area and the work area are secured is not limited to the SDRAM 10, but may be any other type of input / output memory.
For example, in recent years, adoption of a CPU having a built-in RAM in a printer has been studied, and in such a printer, it is preferable to use the built-in RAM as the second memory. In the printer 1 of the present example, the second memory can be used very efficiently, so that a large amount of data can be processed using the small-capacity RAM built in the CPU, and a printer with a high processing speed can be provided.

Further, in the above description, the present invention has been described by using an example in which the ROM 7 is the first memory and the SDRAM 10 is the second memory. However, the combination of memories is not limited to this. DRAM and a printer equipped with a high-speed SDRAM, as well as ROM,
Needless to say, the present invention can be applied to a printer including a DRAM and an SDRAM.

Further, in the above description, an example in which two program modules are copied to the SDRAM 10 has been described, but it goes without saying that the number of program modules is not limited to the above.

The above-described control method can be realized by software having an instruction capable of executing processing corresponding to each step of FIGS. 4 and 5, and can be implemented by a ROM or the like readable by an image processing apparatus. Such software can be recorded and provided. Further, the program can be provided to the user via a computer network, and can be recorded on the ROM of the image processing device 3 of the printer 1 and used from the user's personal computer.

[0046]

As described above, in the present invention, a program area is set in addition to a work area in a high-speed second memory such as a RAM, and a program is copied and executed in this program area to achieve high-speed operation. Is becoming
On the other hand, when the work area is insufficient, such as a high-resolution color image, a large amount of data can be processed by reducing the program area to increase the work area and executing the program on the first memory. Like that. Therefore, when processing a large amount of data, it is possible to set a sufficient work area in the high-speed second memory and increase the access speed to the data. Therefore, even considering that the access speed to the program is slightly reduced. In addition, the processing time of the entire data processing can be reduced.

When the amount of data is not so large, such as in low resolution or monochrome, a sufficient program area can be set in the high-speed second memory to increase the speed of accessing the program. Can be shortened. Further, according to the present invention, the above-mentioned state can be changed due to the shortage of the work area, so that the use efficiency of the second memory can be increased. For this reason, it is possible to provide a low-cost printing apparatus that can process a color image having a large amount of data at high speed and reliably using the second memory having a limited memory capacity.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic hardware configuration of a printer according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining functions and operations in the printer shown in FIG.

FIG. 3 is a diagram for explaining a control operation when a work area is insufficient in the printer shown in FIG. 1;

FIG. 4 is a flowchart of a process when the power is turned on in the printer shown in FIG. 1;

FIG. 5 is a flowchart of a printing process in the printer shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 printer 2 printing mechanism 3 image processing device 4 input interface circuit 5 ROM 5a initialization program (IPL) 6 CPU 7 ROM (first memory) 7a execution program 9 memory controller 10 SDRAM (second memory) 12 memory management unit Reference Signs List 20 memory management unit 21 setting unit 22 change unit 24 copy unit 25 memory shortage detection unit 26 job management unit A, B, C, D module P program area W work area

Claims (9)

[Claims] An image processing apparatus capable of generating and outputting drawing data based on input data, comprising: a CPU; a first memory capable of storing an execution program of the CPU; a work area of the CPU; A second memory capable of being operated at a higher speed than the first memory; and a memory management means capable of converting a logical address of the CPU into a physical address including addresses of the first and second memories. The memory management means sets a program area in which at least a part of the execution program can be copied and a work area in which image data including the drawing data can be stored in the second memory, and the work area can be copied to the program area. For the program, a setting function for converting a logical address of the CPU into an address of the second memory; Then, at least a part of the program area is released, and the program of the released part is provided with a change function of converting a logical address of the CPU into an address of the first memory. Image processing device. 2. The memory management unit according to claim 1, further comprising: a job management unit capable of managing a process of generating and outputting drawing data based on the input data. An image processing apparatus characterized in that, when the function operates, the conversion process of the data for which the work area is insufficient is redone. 3. The method according to claim 1, wherein the first memory is a ROM, and the second memory is a RAM connected to the same or different bus as the CPU or a RAM built in the CPU. An image processing apparatus characterized by the following. 4. A printing apparatus comprising: the image processing apparatus according to claim 1; and a printing mechanism capable of printing based on the drawing data. 5. A CPU, a first memory capable of storing an execution program of the CPU, and a second memory serving as a work area of the CPU and capable of input / output and having a higher speed than the first memory.
And a memory management means capable of converting a logical address of the CPU into a physical address including an address of the first and second memories, and an image capable of generating drawing data based on input data and outputting the drawing data. A method for controlling a processing device, comprising: setting a program area in which at least a part of the execution program can be copied and a work area in which image data including the drawing data can be stored in the second memory; A setting step of converting the logical address of the CPU into an address of the second memory for the copied program; an image processing step of generating and outputting image data based on the input data; When the work area is insufficient, at least a part of the program area is released, and the Method of controlling an image processing apparatus characterized by comprising a changing step of converting the logical address of the CPU to the address of the first memory for programs. 6. The method according to claim 5, further comprising, in the image processing step, when the change step is performed, the conversion of data whose work area is insufficient is redone. 7. The CPU according to claim 5, wherein the first memory is a ROM, and the second memory is a RAM connected to the same or different bus as the CPU.
A method for controlling an image processing apparatus, characterized in that the control means is a RAM incorporated in the image processing apparatus. 8. A CPU, a first memory capable of storing an execution program of the CPU, and a second memory serving as a work area of the CPU, capable of inputting and outputting data, and having a higher speed than the first memory.
And a memory management means capable of converting a logical address of the CPU into a physical address including an address of the first and second memories, and an image capable of generating drawing data based on input data and outputting the drawing data. A control program for a processing device, wherein, in the second memory, a program area capable of copying at least a part of the execution program and a work area capable of storing image data including the drawing data are set;
A setting process of converting a logical address of the CPU into an address of the second memory for the program copied to the program area; an image generating process of generating and outputting image data based on the input data; When the work area is insufficient in the generation processing, at least a part of the program area is released, and a change processing of converting a logical address of the CPU into an address of the first memory is performed for the program of the released part. A computer-readable recording medium on which the control program having executable instructions is recorded. 9. The control program according to claim 8, wherein in the image generation process, when the change process is performed, the control program having an instruction capable of executing a process of re-converting the data whose work area is insufficient is recorded. A computer-readable recording medium characterized by the following.