JP2004096253A - Iamge forming method and apparatus there of - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively process images and make an image forming process at a high speed by scheduling received process requests. <P>SOLUTION: A scheduler comprises a queue manager 51, a scheduling unit 52, an HW process setting/executing unit 53 and a scheduling table manager 54. The queue manager 51 receives a process request from a task requesting am HW turn process, and the scheduling unit 52 selects a scheduling table suited to printing conditions received from an operating unit, etc. among scheduling tables stored in the table manager 54. Based on the executing order of tasks prescribed in the selected scheduling table, it increments a parameter (k) showing the executing number of the task to select the tasks in the HW turn processing unit in the order starting from the first task, and the HW process setting/executing unit 53 sets the conditions of the HW turn process in the task and executes it. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming method and an image forming apparatus, and more particularly, to an image forming apparatus such as a printer, a copier, and a facsimile communication apparatus.
[0002]
[Prior art]
As disclosed in Japanese Patent Application Laid-Open No. 2001-334648, in recent years, in addition to the function as an image forming apparatus, a multifunction peripheral having a function as a copier and a facsimile communication apparatus by providing a scanner and a modem has been put into practical use. Has been Such a multi-function device has a rotation processing function of rotating image data to form an image when the image direction acquired by the scanner does not match the image forming direction of the recording sheet. A mirror processing function for forming an image by reversing the left-right direction of the image, a Nin1 processing function for forming a plurality of images on one recording sheet, and the like are provided. It is possible to automatically correct a rudimentary error such as an error in the sheet feeding direction at the time of formation, thereby realizing a convenient and gentle processing function for the user.
[0003]
[Problems to be solved by the invention]
However, since the above-described processing functions are realized by software (hereinafter, referred to as SW) processing, which is a general-purpose processing, using an image processing LSI provided in the multifunction peripheral, the image data amount increases. There is a problem that the number of processes increases and the load of the SW process increases.
[0004]
Further, even if the inkjet printer, which is an image forming unit, is configured so that the rotation processing function and the mirror processing function can be processed by hardware (hereinafter, referred to as HW), the image data read from the scanner is subjected to image processing (rotation processing and rotation processing). In the case of performing mirror processing or the like), image processing is performed by SW processing instead of the HW processing. Therefore, it is necessary to wait for image forming processing until the SW processing by the scanner is completed, and the processing time of the image forming processing is wastefully wasted. However, there is a problem that the processing efficiency is low.
[0005]
Furthermore, a method of reducing the load of the SW processing by the scanner and speeding up the image processing by executing a part of the image processing by the scanner by the HW processing provided in the ink jet printer can be considered. If only one process (single task) can be executed at a time and a plurality of tasks request HW processing, one task causes another task to wait, and the overall processing time may be lengthened. .
[0006]
The present invention has been made in view of such circumstances, and has been made in consideration of a high-speed processing received from an image data processing unit that performs image processing on image data and an image forming data generation processing unit that generates image forming data from the image data. Scheduling the processing request in the possible HW processing means to efficiently process the processing in the HW processing means, and to speed up the image forming processing by exhibiting the advantage of speeding up the processing by the HW processing. It is a main object of the present invention to provide an image forming method and an image forming apparatus capable of performing the above-described operations.
[0007]
Further, according to the present invention, since the processing request frequency in the HW processing unit received from the image data processing unit and the image formation data generation processing unit greatly varies depending on the image forming conditions, it is possible to perform optimal scheduling for each image forming condition. Accordingly, an object of the present invention is to provide an image forming method and an image forming apparatus which can efficiently process an image forming process and speed up the image forming process.
[0008]
Further, the present invention uses a scheduling table to determine the execution order of the processes in the HW processing unit received from the image data processing unit and the image formation data generation processing unit, thereby enabling efficient processing with respect to a condition assumed in advance. It is an object of the present invention to provide an image forming method and an image forming apparatus capable of defining a scheduling table so that the image forming process can be efficiently performed and speeding up the image forming process.
[0009]
[Means for Solving the Problems]
An image forming method according to the present invention receives an image forming process condition for image data, performs image processing on the image data by an image data processing unit based on the received condition, and outputs an image by an image forming data generation processing unit. In an image forming method of an image forming apparatus for generating image forming data from data and forming an image on a recording sheet based on the generated image forming data, the image forming apparatus may perform a specific process on the image data. The image data processing means for performing the specific processing in the image data processing means and the image forming data generation processing means so as to be processed by the hardware processing means. And receiving a processing request from the image forming data generation processing unit, managing the received processing request as a queue, and receiving the processing request. Determining which of the image data processing means or the image formation data generation processing means is to be executed by the hardware processing means in the managed queue based on the conditions of the image forming processing. It is characterized by.
[0010]
In such an image forming method of the present invention, specific processing is performed by image data processing means for performing image processing on image data and image forming data generation processing means for generating image forming data from image data. At this time, the processing is performed by the HW processing unit capable of performing the specific processing, and the processing request in the HW processing unit received from the image data processing unit and the image formation data generation processing unit is managed in two queues. By determining which processing should be executed based on the received image forming conditions, it is possible to efficiently process processing requests from the image data processing unit and the image forming data generation processing unit.
[0011]
Further, in the image forming method according to the present invention, a plurality of scheduling tables defining an execution order of the processing are stored in the image forming apparatus in advance, and one scheduling table is selected from the plurality of scheduling tables. , The execution order of the processes is determined.
[0012]
In such an image forming method of the present invention, the scheduling order is used to determine the execution order of the processing requests from the image data processing unit and the image forming data generation processing unit in the HW processing unit, thereby presuming the execution order. A scheduling table can be defined so that efficient processing can be performed. Further, by selecting one scheduling table from the plurality of scheduling tables based on the accepted conditions of the image forming process, executing a process based on a scheduling table optimized for the conditions of the image forming process, Processing with optimum processing efficiency can be performed.
[0013]
An image forming apparatus according to the present invention includes a processing condition receiving unit that receives a condition of an image forming process for image data, an image data processing unit that performs image processing on image data based on the received condition of the image forming process, An image forming data generating means for generating image forming data from the data, and forming an image on a recording sheet based on the generated image forming data. Hardware processing means for performing the above-mentioned processing, and when performing the specific processing by the image data processing means and the image forming data generation processing means, the image data processing means for performing the processing by the hardware processing means. Means and a processing request management means for receiving a processing request from the image forming data generation processing means and managing them as a queue, respectively. Any one of the image data processing means or the image formation data generation processing means in a queue managed by the processing request management means based on the image forming processing conditions received by the processing condition reception means. And a scheduling means for deciding whether or not to execute the above processing by the hardware processing means.
[0014]
In such an image forming apparatus of the present invention, specific processing is performed by image data processing means for performing image processing on image data and image forming data generation processing means for generating image forming data from the image data. At this time, the processing is performed by HW processing means capable of performing the specific processing, and the processing request management means receives processing requests from the image data processing means and the image formation data generation processing means, The processing request from the image data processing means and the image formation data generation processing means can be efficiently processed by determining which processing to be executed by the scheduling means based on the received image forming conditions. can do.
[0015]
Further, in the image forming apparatus according to the present invention, the scheduling unit includes: a unit that stores a plurality of scheduling tables defining an execution order of processing in advance; and a unit that selects one scheduling table from the plurality of scheduling tables. It is characterized by having.
[0016]
In such an image forming apparatus according to the present invention, the scheduling unit determines the execution order of the processing requests from the image data processing unit and the image formation data generation processing unit in the HW processing unit using the scheduling table. Accordingly, the scheduling table can be defined so that efficient processing assumed in advance can be performed. In addition, the scheduling unit selects one scheduling table from the plurality of scheduling tables based on the accepted conditions of the image forming process, thereby performing a process based on the scheduling table optimized for the conditions of the image forming process. And the processing with the optimum processing efficiency can be performed.
[0017]
Further, in the image forming apparatus according to the present invention, the processing condition receiving means includes a plurality of image forming modes classified according to image resolution as conditions of the image forming process.
[0018]
In such an image forming apparatus of the present invention, when performing the processing by the scheduling means, the image forming modes classified according to the image resolution that greatly affects the processing speed are set in advance for each image forming mode. By storing the optimum scheduling table and selecting the optimum scheduling table based on the conditions of the image forming processing, the processing with the optimum processing efficiency can be performed.
[0019]
Further, the image forming apparatus according to the present invention includes a reading unit that reads an image written on a document and converts the image into image data, and the processing condition receiving unit sets a reading condition of the reading unit as a condition of the image forming process. It is characterized by including.
[0020]
In such an image forming apparatus of the present invention, when performing a process of reading an image by the reading unit, the reading condition of the reading unit that greatly affects the processing speed is set in advance for each reading condition of the reading unit. The optimal scheduling table is stored in advance, and the optimal scheduling table is selected based on the conditions of the image forming processing, whereby the processing with the optimal processing efficiency can be performed.
[0021]
Further, in the image forming apparatus according to the present invention, the scheduling unit may execute an execution standby time based on a time of the processing and a time at which the processing request is received by the processing request management unit during the processing by the hardware processing unit. And a means for determining whether or not the detected execution standby time exceeds a preset upper limit. When the execution standby time exceeds the upper limit, A table switching unit that switches the scheduling table when the determination is made.
[0022]
In such an image forming apparatus of the present invention, the execution standby time of the processing by the HW processing unit from the image data processing unit and the image formation data generation processing unit is detected, and the detected execution standby time is set in advance. The image data processing means determines whether or not the upper limit value is exceeded, and switches the scheduling table when it is determined that the upper limit value is exceeded, so that the execution standby time in the HW process is equal to or less than a predetermined upper limit value. In addition, the execution order of the processing in the HW processing unit from the image formation data generation processing unit can be changed, and the execution standby time can be reduced.
[0023]
Further, in the image forming apparatus according to the present invention, the scheduling unit includes a unit that detects a registration number of a queue managed by the processing request management unit, and the detected registration number sets a predetermined upper limit value. Means for determining whether or not the number of registrations exceeds the upper limit, and table switching means for switching a scheduling table when it is determined that the number of registrations exceeds the upper limit. I do.
[0024]
In such an image forming apparatus of the present invention, the number of registered processes (the number of queues) by the HW processing unit from the image data processing unit and the image formation data generation processing unit is detected, and the detected registration number is determined in advance. It is determined whether or not the set upper limit value is exceeded, and if it is determined that the set upper limit value is exceeded, the scheduling table is switched so that the number of registered processes in the HW process becomes equal to or less than a preset upper limit value. The execution order of the processes in the HW processing unit from the image data processing unit and the image formation data generation processing unit can be changed, and the number of registered processes can be reduced.
[0025]
Further, in the image forming apparatus according to the present invention, the scheduling unit may determine a data amount of the image data processed by the hardware processing unit when the switchable scheduling table does not exist in the table switching unit. It is characterized by having a means for changing.
[0026]
In such an image forming apparatus of the present invention, when there is no switchable scheduling table in the table switching unit, the data amount of the image data processed by the HW processing unit is changed. The data amount of the processing in the HW processing means can be reduced, and the time required for one processing can be reduced.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments.
FIG. 1 is a perspective view showing the appearance of a composite ink jet printer which is an example of the image forming apparatus of the present invention. In the figure, reference numeral 1 denotes a composite type ink jet printer, in which a scanner 3 is arranged on a printer main body 2 which forms an image on a recording sheet by an ink jet method (hereinafter, referred to as printing).
[0028]
The printer body 2 takes out the recording sheets stored in the recording sheet storage unit 4 one by one as shown by an arrow 8 in FIG. The sheet is discharged from the discharge port 6 onto the discharge tray 7.
[0029]
The scanner 3 is provided with a document cover 32 and a platen glass 33 on the upper part, and shields external light with the document cover 32, and digitally converts images and characters written on the document set on the platen glass 33 into digital data. An image is captured by an optical unit, which will be described later, having a function of capturing as image data.
[0030]
2 is a cross-sectional view of the composite inkjet printer 1 of FIG. 1 as viewed from the right side, and FIG. 3 is a cross-sectional view of the printing unit 5 of FIG. 1 as viewed from the front. The recording sheets 12 stacked and stored on a sheet feeding cassette 11 provided at a lower portion in the recording sheet storing section 4 are taken out one by one by a pickup roller 13 which is in contact with the upper surface thereof, and a pair of upper and lower sheet feeding sheets is provided. The sheet is conveyed to the printing unit 5 via the rollers 14 and the U-shaped recording sheet conveying path 15. A pair of upper and lower PS rollers 16 are provided immediately before the printing unit 5, and the PS rollers 16 perform skew adjustment and timing adjustment of the recording sheet 12 with respect to the printing unit 5.
[0031]
The recording sheet 12 conveyed to the printing unit 5 is subjected to a printing process by a print head 17a mounted on a carriage 17 provided in the printing unit 5.
[0032]
The carriage 17 is supported by a pair of guide shafts 18 that can be extended and contracted in the depth direction of the printer main body 2 (the left-right direction in FIG. 2), and can be displaced in the main scanning direction (left-right direction in FIG. 2) 19 by the guide shafts 18. In addition, the carriage 17 is fixed to one point of the timing belt 22 wound between the pair of pulleys 20 and 21, and one of the pulleys 20 is driven by the motor 23. Is driven to a predetermined position in the main scanning direction 19.
[0033]
The printing unit 5 includes a platen 24 that supports the recording sheet 12 from the back. The recording sheet 12 is conveyed by the platen 24 so as to face the print head 17a displaced in the main scanning direction 19, and the print head 17a Prints a predetermined image.
[0034]
Immediately after the printing unit 5, a star roller 25 and a discharge roller 26 are provided. The printed recording sheet 12 is nipped by the star roller 25 and the discharge roller 26 and discharged onto the discharge tray 7. You.
[0035]
On the other hand, the scanner 3 includes an optical unit 31, a document cover 32, and a platen glass 33. The optical unit 31 is set on the platen glass 33 by being displaced in the sub-scanning direction (the horizontal direction in FIG. 2). The read original image is read in line order.
[0036]
The optical unit 31 includes a light source 35, a first mirror 36, a second mirror 37, a third mirror 38, an image forming lens 39, a charge coupled device (CCD) unit 40, and the like. , Are supported by a guide shaft (not shown) so as to be displaceable in the sub-scanning direction 34, and are driven by a timing belt or the like.
[0037]
FIG. 4 is a block diagram illustrating a configuration of the composite inkjet printer 1 as an example of the image forming apparatus of the present invention. In the figure, reference numeral 42 denotes a control unit provided with a CPU (Central Processing Unit) 42a. The control unit 42 has a function of controlling the scanner 3 and the image processing unit 46. When the instruction of (copy) is received, the control information is output to the scanner 3, the image reading process is commanded to the scanner 3, the control information is output to the image processing unit 46, and the predetermined information is output to the image processing unit 46. Image processing.
[0038]
The scanner 3 starts scanning of the optical unit 31 based on the received control information, reads an image by the CCD unit 40 included in the optical unit 31, and stores the image data obtained by reading in the memory 43.
[0039]
The image processing unit 46 includes an image data processing unit 46a that functions as an image data processing unit and a print data generation processing unit 46b that functions as an image formation data generation processing unit. The image data processing unit 46a includes an operation unit 45 and the like. The print data generation processing unit 46b converts the image data processed by the image data processing unit 46a into print data by accessing the memory 43 based on the print conditions received from the To memorize.
[0040]
The image data processing unit 46a and the print data generation processing unit 46b determine that the scanning direction of the document set on the scanner 3 matches the transport direction of the recording sheet 12 stored in the sheet feeding cassette 11 in the recording sheet storing unit 4. If image processing for rotating image data is necessary, the HW rotation processing unit 47 functioning as HW processing means performs rotation processing by HW processing (hereinafter referred to as HW rotation processing).
[0041]
When performing the HW rotation processing in the HW rotation processing unit 47, the image data processing unit 46a and the print data generation processing unit 46b first output a processing request of the HW rotation processing to the scheduler unit 48, and receive the processing request. The unit 48 manages the HW rotation processing based on the scheduling table described later, thereby efficiently operating the processing in the HW rotation processing unit 47 and reducing the print processing time.
[0042]
When the print data generated and processed by the image processing unit 46 accumulates data for one line, the print unit 5 outputs the control information and the print data to the print unit 5 and receives the print data. The scanning of the carriage 17 is started based on the control information.
[0043]
FIG. 5 is a block diagram illustrating a configuration of the scheduler unit 48 included in the image forming apparatus of the present invention. The scheduler unit 48 includes a queue management unit 51 functioning as a processing request management unit, a scheduling unit 52 functioning as a scheduling unit, an HW processing setting / execution unit 53, and a scheduling table management unit 54. The processing request (queue) is received (queued) from the task requesting the HW rotation processing by the HW rotation processing unit 47, and the scheduling unit 52 determines the operation unit from the plurality of scheduling tables stored in the scheduling table management unit 54 in advance. For example, a scheduling table suitable for printing conditions accepted by the user such as 45, for example, scanning resolution and printing mode, is selected.
[0044]
As shown in FIG. 6, the scheduling table has a configuration that defines the execution order of tasks (TABLEi (i = 1, 2,..., 11), i: table number), and task A is transmitted from the image data processing unit 46a. An image data processing task that has received a processing request, and task B indicates a print data generation processing task that has received a processing request from the print data generation processing unit 46b. For example, TABLE1 is a scheduling table that defines task A in execution order 1, task B in execution order 2, task B in execution order 3, task B in execution order 4, and task B in execution order 5. When the scheduling unit 52 selects TABLE1, task A, task B, task B, task B, and task B are executed in this order. The queue execution order of the task A and the task B is a FIFO (First In First Out) format in which the tasks are executed in the order of the time received by the queue management unit 51. For the task A, the queue A1, the queue A2,. Are executed in this order, and for task B, queue B1, queue B2,... Are executed in this order. Therefore, the queue management unit 51 executes the tasks in the order of the queue A1, the queue B1, the queue B2, the queue B3, and the queue B4.
[0045]
TABLE 6 is a scheduling table that alternately executes task A and task B, and is a mode in which image data processing and print data generation processing are executed equally. TABLE3 is a scheduling table in which one task is executed by the task A and two tasks are executed by the task B. In this mode, the print data generation processing is executed with higher priority than the image data processing. TABLE 9 is a scheduling table in which task B executes one task while task A executes two tasks, and is a mode in which image data processing is executed with priority over print data generation processing.
[0046]
Therefore, regarding the method of selecting the scheduling table, for example, in the case of the draft print mode in which the image resolution is low and the moving speed of the carriage 17 is high, the processing request of the HW rotation processing from the print data generation processing unit 46b frequently occurs. Therefore, it is more efficient to use a scheduling table that preferentially processes a processing request from task B, which is print data generation processing, and TABLE3 is selected as a default scheduling table.
[0047]
On the other hand, in the fine print mode in which the image resolution is high and the moving speed of the carriage 17 is slow, the processing load on the image data processing increases. Using a table allows more efficient processing, and TABLE9 is selected as a default scheduling table.
[0048]
Further, it is also possible to correct TABLE selection in accordance with the reading conditions of the scanner 3 in a state where TABLEi is selected. When reading conditions that increase the processing load of image data processing, for example, reading conditions such as increasing the resolution of the scanner 3 are set, the scheduling table is shifted in the direction of arrow b in FIG. That is, i of TABLEi is incremented, and the processing is switched to the scheduling table for processing the processing request from the image data processing unit 46a with priority. On the other hand, when reading conditions that reduce the processing load of image data processing, for example, reading conditions such as setting the resolution of the scanner 3 to low resolution, are set, the scheduling table is shifted in the direction of arrow a in FIG. In other words, i of TABLEi is decremented, and the processing is switched to the scheduling table that preferentially processes the processing request from the print data generation processing unit 46b.
[0049]
Furthermore, the execution waiting time of the actual image data processing task and the print data generation processing task is detected, and if it is determined that any of the tasks is delayed, the default scheduling table is used to determine the delayed task. By shifting the processing request to a scheduling table defined to process the processing request with priority, efficient processing can be performed.
[0050]
The scheduling unit 52 selects a task to be processed by incrementing the variable k indicating the execution number in order from the first task based on the execution order of the tasks defined by the scheduling table, and sets the HW processing setting / execution unit 53 , The HW rotation processing condition of the task is set, and the HW rotation processing unit 47 executes the HW rotation processing.
[0051]
When the variable k becomes the last number of the scheduling table (in the figure, "execution order 5"), the process returns to the start number of the scheduling table, that is, "execution order 1," and the task is selected again. This allows efficient operation even when the number of queued tasks is larger than the number of tasks specified in the scheduling table.
[0052]
If the execution right has been transferred to the task selected by the variable k in the scheduling table, but there is no processing request for HW rotation processing from the task, the task is not executed and the variable k is incremented. Then, by executing the task of the next execution number, efficient processing is possible.
[0053]
The significance of the present invention is that the scheduling of the HW rotation process under the accepted printing conditions is performed by selecting a scheduling table from the scheduling table management unit 54 based on the printing conditions received from the operation unit 45 or the like. .
[0054]
FIG. 7 is a flowchart illustrating a procedure of an image forming process performed by the image forming apparatus of the present invention. When the document to be copied is set on the platen glass 33 (S61) and the printing condition is selected by the operation unit 45 or the like (S62), the document is set on the scanner 3 based on the printing condition selected in S62. It is determined whether or not the scanning direction of the document does not match the transport direction of the recording sheet 12 and HW rotation processing is required at the time of printing (S63).
[0055]
If it is determined in S63 that the HW rotation processing is necessary (S63: YES), the HW rotation processing unit 47 does not perform the processing in the image data processing unit 46a and the print data generation processing unit 46b. Therefore, a scheduling table suitable for the printing condition selected in S62 is selected from the scheduling table management unit 54 and set as a scheduling table of the scheduling unit 52 (S64).
[0056]
When an instruction to start a printing operation is input from the operation unit 45 (S65), the image is read from the scanner 3 and converted into image data, and the printing operation is started (S66). Image processing such as mirror processing and Nin1 processing (special functions) when image processing such as gamma correction, shading, and filtering is set on the image data read from the scanner 3, and under the printing conditions selected in S62. If (processing) is set, image processing corresponding to the setting is executed by the image data processing unit 46a (S67). However, the image processing (rotation processing) of the image data requiring rotation is performed not by the image data processing unit 46a but by the HW rotation processing unit 47.
[0057]
Next, although the details will be described later, the scheduler 48 requests the queue manager 51 of the HW rotation process to perform a scheduler process (S68) for executing the HW rotation process of the image.
[0058]
Image processing such as color space conversion processing, error diffusion processing, and dither processing is performed from the image data on which image processing, special function processing, and HW rotation processing have been completed to generate print data (S69). The scheduler process (S70) is performed again to speed up the data arrangement to each print head nozzle. That is, a request for the HW rotation processing is made again to the queue management section 51 of the scheduler section 48, and the HW rotation processing of the image is executed.
[0059]
Then, it is determined whether or not the printing has been completed (S71). If it is determined that the printing has been completed (S71: YES), the process is terminated, and it is determined that the printing has not been completed (S71: NO). If so, the process returns to S67, and the processes from S67 to S70 are executed again.
[0060]
On the other hand, if it is determined in S63 that the HW rotation processing is not necessary (S63: NO), the task of the image data processing unit 46a does not need to use the HW rotation processing, and the operation unit 45 performs the printing operation. When the start instruction is input (S72), the image is read from the scanner 3 and converted into image data, and the printing operation is started (S73). When image processing such as gamma correction, shading, and filtering is set on the image data read from the scanner 3, and under the printing conditions selected in S62, image processing such as mirror processing and Nin1 processing (special functions) If (processing) is set, the image data processing unit 46a executes image processing corresponding to the setting (S74).
[0061]
Image processing such as color space conversion processing, error diffusion processing, and dither processing is performed from the image data on which image processing and special function processing have been completed to generate print data (S75). In order to speed up the data arrangement, HW rotation processing is performed by the HW rotation processing unit 47 (S76).
[0062]
Then, it is determined whether or not the printing is completed (S77). If it is determined that the printing is completed (S77: YES), the process is terminated, and it is determined that the printing is not completed (S77: NO). If so, the process returns to S74, and the processes from S74 to S76 are executed again.
[0063]
FIGS. 8, 9, and 10 are flowcharts illustrating the procedure of the scheduler process performed by the image forming apparatus of the present invention. The execution standby time of the task received from the image data processing unit 46a and the print data generation processing unit 46b is detected (S81), and it is determined whether the switching of the scheduling table is necessary so that the task can be executed efficiently. . For example, the execution standby time may be calculated by calculating the time difference between the time at which the task was received and the current time.
[0064]
To explain the switching condition of the scheduling table in detail, for example, in the present embodiment, the execution standby time exceeds the upper limit time (for example, the time required for moving the carriage 17 (scanning time) + α) which is the table switching threshold. It is determined whether or not it is performed (S82). Then, in S82, when it is determined that the execution standby time exceeds the upper limit time (S82: YES), the HW rotation processing for counting the number of executions of the HW rotation processing in the selected scheduling table is performed. It is determined whether or not the numerical value j of the counter exceeds a preset counter upper limit value (for example, numerical value “10”) (S83). Further, in S83, when it is determined that the numerical value j of the HW rotation processing counter exceeds the counter upper limit value (S83: YES), it is determined whether or not the table switching disable flag is set (S84). ). When it is determined in S84 that the table switching disable flag is not set (S84: NO), it is determined that the switching of the scheduling table is necessary.
[0065]
On the other hand, if it is determined in S82 that the execution standby time does not exceed the upper limit time (S82: NO), it is determined in S83 that the numerical value j of the HW rotation processing counter does not exceed the counter upper limit value (S83). : NO), or when it is determined in S84 that the table switching disable flag is set (S84: YES), it is determined that the switching of the scheduling table is not necessary.
[0066]
If it is determined in S82, S83, and S84 that the switching of the scheduling table is not necessary, it is determined whether there is a processing request for the HW rotation process from the image data processing unit 46a and the print data generation processing unit 46b (S85). ). If it is determined in S85 that there is a processing request for the HW rotation processing (S85: YES), it is determined whether there is an empty queue that can be registered (S86). When it is determined in S86 that there is an empty queue that can be registered (S86: YES), the queue is registered (S87), and it is determined whether the HW rotation processing unit 47 is in the HW rotation processing enabled state (S88). ). In S88, when it is determined that the HW rotation processing unit 47 is not in the HW rotation processing enabled state (S88: NO), the scheduler processing ends as it is.
[0067]
On the other hand, if it is determined in S86 that there is no empty queue that can be registered (S86: NO), the task that has issued the processing request is notified that queuing was not possible (S89), and S88. Move to
[0068]
On the other hand, if it is determined in S85 that there is no processing request for the HW rotation processing (S85: NO), it is determined whether there is a registration queue (S90). In S90, when it is determined that there is a registration queue (S90: YES), the process proceeds to S88, and when it is determined that there is no registration queue (S90: NO), the scheduler process ends as it is.
[0069]
If it is determined in S88 that the HW rotation process is in a processable state (S88: YES), the task (task A or task B) stored in association with the variable k indicating the execution number of the scheduling table Is set in the register for the HW rotation processing (S91), and the HW rotation processing unit 47 executes the HW rotation processing (S92).
[0070]
Next, when the execution is performed up to the last number of the scheduling table, it is necessary to return to the start number of the scheduling table. Therefore, it is determined whether or not the variable k is equal to or larger than the last number of the scheduling table (S93). If it is determined in S93 that the variable k is equal to or greater than the final number (S93: YES), the variable k is reset to 0 (S94), and the numerical value j and the variable k of the HW rotation processing counter are incremented (S95). I do. On the other hand, when it is determined in S93 that the variable k is smaller than the final number (S93: NO), the variable k is held and the process proceeds to S95. Then, the queue in which the register setting of the HW rotation process has been performed is released from the queue of the queue management unit 51 (S96), and the scheduler process ends.
[0071]
If it is determined in S82, S83, and S84 that the switching of the scheduling table is necessary, after the processing is started, the value l of the table switching counter indicating how many times the scheduling table has been switched is checked, and it has never been changed. It is determined whether the scheduling table has not been switched, that is, whether or not the numerical value 1 of the table switching counter is 0 (S97).
[0072]
If it is determined in S97 that the scheduling table has never been switched, that is, if it is determined that the numerical value 1 of the table switching counter is 0 (S97: YES), the processing request task detected in S81 determines the table number. Is stored as the best performance table (optimum table) in association with the execution standby time (S98). Then, the next table X is selected as a new scheduling table (S99), the numerical value l of the table switching counter is incremented (S100), the numerical value j of the HW rotation processing counter is reset to 0 (S101), and the scheduler processing is performed. finish.
[0073]
On the other hand, in S97, the switching of the scheduling table has been performed, that is, when it is determined that the numerical value l of the table switching counter is not 0 (S97: NO), whether the switchable scheduling table remains. It is determined whether or not there is (S102). In S102, when it is determined that the switchable scheduling table remains (S102: YES), it is determined whether or not the execution standby time of the currently selected scheduling table has been improved from the optimal table execution standby time. That is, it is determined whether the execution standby time detected in S81 is shorter than the execution standby time of the optimum table (S103).
[0074]
If it is determined in S103 that the execution standby time of the currently selected scheduling table is shorter (S103: YES), the process proceeds to S98.
[0075]
On the other hand, if it is determined in S103 that the execution waiting time of the currently selected scheduling table is longer (S103: NO), a table Y different from table X is selected as a new scheduling table (S104), and S100 is executed. Move to
[0076]
For example, if the table X is determined to increment the table number managed by the scheduling table management unit 54 and the table Y is determined to decrement the table number, the table Y is determined based on the determination result in S103. Thus, it is possible to reverse the increase / decrease in the ratio of the number of processes between the image data processing task A and the print data generation processing task B specified in the scheduling table, and it is possible to efficiently determine the optimum table.
[0077]
If it is determined in S102 that there are no switchable scheduling tables remaining (S102: NO), it means that the execution standby time has been detected for all the scheduling tables managed by the scheduling table management unit 54. Instead of selecting a new scheduling table, the optimum table is selected as the scheduling table (S105), and since the execution waiting time has been detected for all the scheduling tables, table switching indicating that there is no need to switch the scheduling tables is performed. The disabling flag is set (S106), and the routine goes to S100.
[0078]
If it is determined in S102 that no switchable scheduling table remains (S102: NO), the optimal table is selected as the scheduling table (S105), and a table switch disable flag is set (S106). Then, the data amount of the image data may be further changed, the data amount of the image processing may be reduced, and the scheduling table may operate more efficiently, and the process may shift to S100.
[0079]
FIG. 11 is a schematic diagram showing images before and after the HW rotation processing. If the scanning direction of the document and the conveyance direction of the recording sheet 12 are the same as shown in FIG. 7A, it is not necessary to perform the HW rotation processing on the image data, and as shown in FIG. When the scanning direction of the document and the transport direction of the recording sheet 12 are perpendicular to each other, the image data acquired by the scanner 3 is HW-rotated 90 ° counterclockwise to match the transport direction of the recording sheet 12. There is a need.
[0080]
FIG. 12 is a schematic diagram showing the arrangement of print head nozzles and print data. In FIG. 12, each cell indicates a print head nozzle, the upper row shows the nozzle number of the print head nozzle, and the lower row shows an example of print data. As shown in FIG. 12, the print head nozzles are arranged in the direction perpendicular to the moving direction of the carriage 17, that is, the main scanning direction.
[0081]
FIG. 13 is a schematic diagram showing a memory address and print data before performing the HW rotation process, and FIG. 14 is a schematic diagram showing a memory address and print data after performing the HW rotation process. . 13 and 14, each cell indicates a memory cell, and an upper row of each cell indicates a memory address (address), and a lower row indicates an example of print data. As shown in a portion surrounded by a thick frame in FIG. 12, the print data is arranged in the order of the print head nozzles, that is, the nozzle numbers (1, 2,..., 16, 17, 18,..., 32, 33, 34). ,..., 48), the print data is printed in the order of data A1, A2,..., A16, B1, B2,..., B16, C1, C2,. 17a.
[0082]
The printing data before rotation is arranged in the moving direction (main scanning direction) of the carriage, as shown in a portion surrounded by a thick frame in FIG. 13, and data A1, B1, C1,..., A2, B2 , C2,... Are stored in the memory 43 in this order. Therefore, since the print data to be transmitted in the transfer order is arranged at discontinuous memory addresses in the memory space, the data A1, A2, ..., A16, B1, B2, ..., B16, C1, C2, ..., If data is to be transferred in the order of C16, first, the memory address (“0x0000”) where the data A1 is stored is specified and the data A1 is transferred, and then the moving direction of the carriage from the memory address (“0x0000”) Since the data A2 is transferred by specifying the added memory address ("0x0100") for the number of nozzles (256) in the (main scanning direction), the print data must be transferred in nozzle units. There is a disadvantage that the processing load increases.
[0083]
On the other hand, by performing the HW rotation processing, the print data after rotation is transferred to the print data to be sent in the transfer order as shown in a portion surrounded by a thick frame in FIG. Are located in Therefore, when transferring the print data, the data A1, A2, and A2 are specified by specifying the memory address (“0x0ff0”) where the data A1 is stored and the number (16) of nozzles in the transport direction of the recording sheet 12. .., A16 can be transferred in line units. Since the data B1, B2,..., B16 and the data C1, C2,..., C16 can be transferred in the same manner, the processing load can be greatly reduced as compared with the method in which the HW rotation processing is not performed.
[0084]
In the description of the embodiment of the present invention, the rotation processing of the image data with respect to the scanning direction of the original set on the scanner has been described. However, the present invention is not limited to this, and it is not limited to the processing from a personal computer connected via an interface. The present invention is also applicable to a rotation process for requested image data.
[0085]
Further, the HW processing is not limited to the rotation processing, but is also applicable to HW mirror processing and the like, and the present embodiment is applicable to a plurality of HW processing.
[0086]
Further, the case has been described in which the execution waiting time of the task is detected and the scheduling table is selected so that the execution waiting time is minimized. However, the present invention is not limited to this. May be selected such that is minimized.
[0087]
【The invention's effect】
As described in detail above, according to the present invention, a request for processing in the HW processing unit received from the image data processing unit and the image formation data generation processing unit is managed in two queues, and either processing is executed. It is determined by the received image forming condition that the image data should be processed, and the processing request from the image data processing unit and the image forming data generation processing unit is efficiently processed. Part of the formation data generation processing can be executed, and the advantage of speeding up the processing by the HW processing can be exerted to speed up the image formation processing.
[0088]
Further, according to the present invention, since the processing request frequency in the HW processing unit from the image data processing unit and the image formation data generation processing unit greatly varies depending on the image forming conditions, it is possible to perform optimal scheduling for each image forming condition. Thus, the image forming process can be efficiently performed, and the image forming process can be speeded up.
[0089]
Further, according to the present invention, by using the scheduling table to determine the execution order of the processing in the HW processing unit from the image data processing unit and the image formation data generation processing unit, it is possible to efficiently perform the processing on the condition assumed in advance. The scheduling table can be defined so that processing can be performed, and excellent effects can be achieved, such as efficient image forming processing and high-speed image forming processing.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating the appearance of a composite inkjet printer as an example of an image forming apparatus of the present invention.
FIG. 2 is a cross-sectional view of the composite inkjet printer of FIG. 1 as viewed from a right side.
FIG. 3 is a sectional view of the printing unit of FIG. 1 as viewed from the front.
FIG. 4 is a block diagram illustrating a configuration of a composite inkjet printer as an example of the image forming apparatus of the present invention.
FIG. 5 is a block diagram illustrating a configuration of a scheduler unit included in the image forming apparatus of the present invention.
FIG. 6 is a table diagram illustrating an example of a scheduling table stored in the image forming apparatus of the present invention.
FIG. 7 is a flowchart illustrating a procedure of an image forming process performed by the image forming apparatus of the present invention.
FIG. 8 is a flowchart illustrating a procedure of a scheduler process performed by the image forming apparatus of the present invention.
FIG. 9 is a flowchart illustrating a procedure of a scheduler process performed by the image forming apparatus of the present invention.
FIG. 10 is a flowchart illustrating a procedure of a scheduler process performed by the image forming apparatus of the present invention.
FIG. 11 is a schematic diagram showing images before and after HW rotation processing.
FIG. 12 is a schematic diagram showing the arrangement of print head nozzles and print data.
FIG. 13 is a schematic diagram showing a memory address and print data before HW rotation processing is performed.
FIG. 14 is a schematic diagram showing a memory address and print data after performing HW rotation processing.
[Explanation of symbols]
1 Composite inkjet printer
2 Printer body
3 Scanner
4 Recording sheet storage
5 Printing department
6 Discharge sheet outlet
7 Discharge sheet tray
17 Carriage
17a print head
31 Optical unit
42 control unit
43 memory
45 Operation unit
46 Image processing unit
46a Image data processing unit
46b print data generation processing unit
47 HW rotation processing unit
48 Scheduler
51 Queue management unit
52 Scheduling unit
53 HW processing setting / executing unit
54 Scheduling Table Management Unit

Claims (9)

Image forming processing conditions are received for the image data, image processing is performed on the image data by the image data processing means based on the received conditions, and image forming data is generated from the image data by the image forming data generating processing means. And an image forming method of an image forming apparatus for forming an image on a recording sheet based on the image forming data subjected to the generation processing,
The image forming apparatus includes a hardware processing unit that performs a specific process on the image data,
When performing the specific processing by the image data processing means and the image formation data generation processing means, the image data processing means and the image formation data generation processing means perform processing by the hardware processing means. Receiving the processing requests, managing the received processing requests as a queue,
Based on the conditions of the received image forming process, it is determined which of the image data processing unit and the image forming data generation processing unit is to be executed by the hardware processing unit in the managed queue. An image forming method. In the image forming apparatus, a plurality of scheduling tables defining the execution order of processing are stored in advance,
2. The image forming method according to claim 1, wherein an execution order of the processes is determined by selecting one scheduling table from the plurality of scheduling tables. Processing condition receiving means for receiving image forming conditions for image data; image data processing means for performing image processing on the image data based on the received conditions for image forming processing; and processing for generating image forming data from the image data An image forming apparatus comprising: an image forming data generation processing unit configured to form an image on a recording sheet based on the generated image forming data.
Hardware processing means for performing specific processing on the image data,
When performing the specific processing by the image data processing means and the image formation data generation processing means, the image data processing means and the image formation data generation processing means perform processing by the hardware processing means. Processing request management means for receiving processing requests and managing each as a queue;
Any one of the image data processing means or the image formation data generation processing means in a queue managed by the processing request management means based on the image forming processing conditions received by the processing condition reception means. An image forming apparatus comprising: a scheduling unit that determines whether or not the above processing is performed by the hardware processing unit. Means for pre-storing a plurality of scheduling tables that define the order of execution of the processing,
4. The image forming apparatus according to claim 3, further comprising: means for selecting one scheduling table from the plurality of scheduling tables. 5. The image forming apparatus according to claim 3, wherein the processing condition receiving unit includes a plurality of image forming modes classified according to an image resolution as a condition of the image forming process. 6. Reading means for reading an image described in the document and converting it to image data,
The image forming apparatus according to claim 3, wherein the processing condition receiving unit includes a reading condition of the reading unit as a condition of the image forming process. Means for detecting, during processing by the hardware processing means, an execution standby time from a time of the processing and a time at which a processing request is received by the processing request management means;
Means for determining whether the detected execution standby time exceeds a preset upper limit value,
7. The apparatus according to claim 4, further comprising: a table switching unit that switches a scheduling table when it is determined that the execution standby time exceeds the upper limit. An image forming apparatus according to claim 1. Means for detecting the number of registered queues managed by the processing request management means,
Means for determining whether the detected number of registrations exceeds a preset upper limit,
7. The apparatus according to claim 4, further comprising: a table switching unit that switches a scheduling table when it is determined that the number of registrations exceeds the upper limit. The image forming apparatus as described in the above. The scheduling means includes means for changing a data amount of image data processed by the hardware processing means when there is no switchable scheduling table in the table switching means. An image forming apparatus according to claim 7 or claim 8.

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