JP4082016B2 - Printer controller, data transfer method, data transfer program, and recording medium recording the program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printer controller, a data transfer method, a data transfer program, and a recording medium on which the program is recorded, and in particular, a printer controller that can perform efficient image data transfer, a data transfer method, a data transfer program, and the The present invention relates to a recording medium on which a program is recorded.
[0002]
[Prior art]
In recent years, printers and other MFPs (Multi Function Peripherals) controllers have enhanced various application functions such as online maintenance accompanying enhanced network functions, and advanced functions for high-speed processing of complex functions. Real-time control is required.
[0003]
In such a situation, when the network function and the application function are enhanced as the OS (Operating System) of the controller, there are abundant available applications, and a general-purpose OS such as Linux having a rich network function is available. Is suitable. However, the general-purpose OS is not suitable for high-speed processing because it does not have a real-time control function.
[0004]
In addition, when emphasizing advanced real-time control, it has a function to predict the required processing time and a mechanism to complete processing within the target time even when multiple processing requests occur simultaneously. Real-time OS such as ITRON (Industrial The Real-time Operating System Nucleus) is suitable. However, since the current real-time OS does not have many applications, the application functions cannot be enhanced unless a new application is developed.
[0005]
In order to solve these problems, a method of adding a real-time function to Linux, which is a general-purpose OS, and simultaneously satisfying the functions required in both cases described above (hereinafter referred to as RT-Linux) has been proposed. Specifically, it is realized by adding a real-time kernel having a real-time function to the Linux kernel.
[0006]
[Problems to be solved by the invention]
However, when the above-described RT-Linux is used as an OS for a controller that transfers image data, there are the following problems.
[0007]
That is, in RT-Linux, it is guaranteed that the data is transferred to the printer at a predetermined cycle by the function of the real-time kernel, but the cycle does not match the cycle of the horizontal synchronization signal for writing to the photoconductor in the laser printer, for example. There is a case. Even in the same printer, the period of the horizontal synchronization signal varies depending on the resolution of the print job.
[0008]
In a system using RT-Linux, the controller checks whether there is a data transfer request from the printer by a periodic activation task of a predetermined period, and operates to send data if there is a data transfer request. . However, if the data transfer cycle and the horizontal sync signal cycle of the printer do not match, the data is requested until the next data transfer request confirmation, such as when there is a data transfer request from the printer immediately after the data transfer request confirmation by the periodic start task. There was a problem that the transfer was delayed and the efficient data transfer could not be executed.
[0009]
Therefore, an object of the present invention is to provide a printer controller, a data transfer method, a data transfer program, and a recording medium on which the program is recorded, which realizes efficient data transfer.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to one aspect of the present invention, the printer controller is a printer controller for transferring image data to a printer, and a control means for executing a general-purpose OS ( Operating System ) to which a real-time function is added. When, a task that is controlled by the real-time capabilities of the general-purpose OS executed by the control means acquires a data output means for outputting the image data of a predetermined amount to the printer, the printer, the period data about the print processing cycle A data output cycle that is a task controlled by the real-time function of the general-purpose OS executed by the data acquisition means and the control means, and sets the start cycle of the data output means based on the cycle data acquired by the periodic data acquisition means Setting means.
[0011]
The printer controller further includes image data resolution recognition means for recognizing the resolution of the image data, and the periodic data acquisition means acquires periodic data relating to print processing according to the image data resolution recognized by the image data resolution recognition means. It is desirable to do.
[0012]
The printer is a laser beam type printer, and it is desirable that the period data acquired by the above-mentioned period data acquisition unit is a period of a horizontal synchronizing signal in writing of the laser beam of the laser beam type printer.
Preferably, the periodic data acquisition means is a task that is controlled in real time by a real-time function of a general-purpose OS executed by the control means, and acquires periodic data from the printer.
[0013]
According to another aspect of the present invention, a data transfer method is a transfer method performed by a printer controller that transfers image data to a printer, and the printer controller includes a control unit that executes a general-purpose OS to which a real-time function is added. The periodic data acquisition step of acquiring periodic data related to the print processing of the printer and the period of outputting image data controlled by the real-time function of the general-purpose OS executed by the control means are acquired in the periodic data acquisition step. A data output cycle setting step that is set based on the data, and a data output step that is controlled by the real-time function of the general-purpose OS executed by the control means and outputs the image data to the printer at the cycle set in the data output cycle setting step With .
[0014]
According to another aspect of the present invention, the data transfer program is a program of a general-purpose OS to which a real-time function is added, and is a program that causes a computer to function as a printer controller that transfers image data to a printer . a task that is controlled by the real-time capabilities of the general-purpose OS, and a data output step of outputting the image data of a predetermined amount to the printer, the printer, the period data acquiring step of acquiring periodic data about the print processing, the general-purpose OS a task that is controlled by the real-time capabilities of an activation period of the data output step, to perform the data output period setting step of setting, based on period data acquired by the periodic data acquiring step.
[0015]
According to another aspect of the present invention, a computer-readable recording medium records the above-described data transfer program.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
[0017]
FIG. 1 is a block diagram illustrating a configuration of a print system 1 according to the present embodiment.
[0018]
With reference to FIG. 1, a print system 1 according to the present embodiment includes a printer controller 10 and a printer 20.
[0019]
The printer controller 10 generates image data (bitmap data) based on a print job received from an external host computer or the like.
[0020]
The printer controller 10 includes a central processing unit (CPU) 11 that controls the entire printer controller 10, a ROM 12 that stores various programs and parameters, and a RAM 13 that temporarily stores programs and data as work areas. A communication I / F (interface) 14 for transmitting / receiving print data to / from an external host computer, a HDD 15 which is a large-capacity storage device, display of the status of the print system 1, input of print instructions, etc. And an image output unit 17 for transmitting image data and the like to and from the printer 20 via the IEEE 1394 serial bus.
[0021]
The HDD 15 has a program for interpreting print control data such as PDL (Page Description Language) in a print job received from an external host computer, etc., and converting it into an intermediate record that is data in a format that can be internally processed. A program for generating image data based on the generated intermediate record is recorded. By executing these programs, image data is generated from the print job.
[0022]
The printer 20 prints out the image data generated by the printer controller 10 based on an instruction from the printer controller 10.
[0023]
The printer 20 performs printing by a laser beam method, a CPU 21 that controls the entire printer 20, a ROM 22 that stores various programs and parameters, a RAM 23 that temporarily stores programs and data as a work area, and the like. The engine unit 25 includes an IEEE 1394 serial bus interface and its control unit, and includes an image input unit 24 that receives image data and the like from the printer controller 10 via the IEEE 1394 serial bus. The engine unit 25 includes a scanner control unit 26 that controls rotation of the polygon mirror, and a high-voltage control unit 27 that performs high-voltage control such as charging of the photosensitive drum, development bias, and transfer bias voltage application to the transfer roller. A laser control unit 28 that performs modulation control of the laser beam, and a conveyance control unit 29 that performs conveyance control of a recording medium such as paper.
[0024]
In the print system 1 having such a configuration, the printer controller 10 and the printer 20 are connected using an IEEE 1394 serial bus, and an isochronous transfer mode that guarantees a certain band is applied.
[0025]
Next, print processing in the print system 1 will be described.
FIG. 2 is a flowchart showing print processing in the printer controller 10. The processing program shown in the flowchart of FIG. 2 is stored in a storage device such as the HDD 15 and is executed by the CPU 11.
[0026]
Referring to FIG. 2, it is first determined whether or not a print job has been received from an external host computer or the like via communication I / F 14 (S101). When a print job is received (Yes in S101), print control information described in PDL is acquired from the print job (S102).
[0027]
Next, the interpreter is used to interpret the PDL (S103), and an intermediate record is created (S104). In steps S103 and S104, it is determined whether or not the generation of the intermediate record for one page is completed (S105).
[0028]
When the generation of the intermediate record for one page is completed (Yes in step S105), the generated intermediate record is registered in the page queue (S106).
[0029]
Next, an intermediate record for one page is extracted from the page queue, and the extraction pointer is incremented by one (S107).
[0030]
The intermediate record extracted in step S107 is converted into image data that can be output to the printer 20 (S108).
[0031]
The image data obtained by the conversion in step S108 is transmitted from the image output unit 17 to the printer 20 via the IEEE 1394 serial bus (S109).
[0032]
Until the print job is completed (Yes in step S110), the series of processing shown in steps S102 to S109 is repeated, and the image data of all the print jobs received in step S101 is transmitted to the printer 20.
[0033]
The above is the flow of processing in the printer controller 10.
On the other hand, when the printer 20 receives the print request signal from the printer controller 10 at the image input unit 24, it outputs a paper feed instruction signal to the transport control unit 29 to instruct the start of paper feed. At the same time, the scanner control unit 26 is instructed to prepare for scanning. Further, charging to the photosensitive drum, development bias, and the like are set via the high voltage control unit 27 to prepare for printing. Next, the laser control unit 28 modulates the laser beam based on the image data input from the printer controller 10 via the image input unit 24 in synchronization with a vertical synchronization signal described later. As a result, an electrostatic latent image is formed on the photosensitive drum.
[0034]
Next, the timing of various signals when printing is performed by the printing system 1 will be described. FIG. 3 is a diagram showing various signal timings related to the operation of the printer 20 when printing one page.
[0035]
Referring to FIG. 3, L6 and L7 indicate vertical and horizontal paper widths for one page, and areas excluding L3, L4, and L1 and L2 from these paper widths are printable areas. The / VSYNC signal is a synchronizing signal in the vertical scanning direction (sub-scanning direction) for starting printing for one page, and the / VSREQ signal is a signal requesting the / VSYNC signal. The / HSYNC signal is a synchronizing signal in the horizontal scanning direction (main scanning direction) for starting printing for each line, and the / VIDEO signal indicates whether or not the printer 20 actually performs printing. It is data. For example, in the case of a monochrome printer, black is displayed when the / VIDEO signal is valid and white when the / VIDEO signal is invalid.
[0036]
When printing based on image data, the printer 20 starts paper feeding if it can be fed immediately, and validates the / VSREQ signal for requesting the / VSYNC signal after a predetermined time. The printer controller 10 validates the / VSYNC signal when the / VSREQ signal is valid, and outputs image data line by line in synchronization with the / HSYNC signal after a predetermined time.
[0037]
The period (t10) of the / HSYNC signal corresponds to the process speed of the printer 20, and is defined by the performance of each printer. The image data is supplied to the printer 20 at a constant speed according to this cycle (t10). The cycle (t10) of the / HSYNC signal becomes shorter as the output speed of the engine is higher and the resolution (image recording density) is higher.
[0038]
Normally, the cycle of the / HSYNC signal (t10) does not coincide with the IEEE 1394 isochronous transfer cycle (125 μsec), but by providing the printer 20 with a buffer memory, the difference in this cycle can be buffered.
[0039]
FIG. 4 shows a specific example of the firmware configuration of the printer controller 10 in the present embodiment. In the present embodiment, RT-Linux in which a real-time processing function is added to Linux, which is a general-purpose OS, is employed as the OS of the printer controller 10.
[0040]
With reference to FIG. 4, the firmware of the printer controller 10 includes a Linux kernel 110 and a real-time kernel 120 as kernels.
[0041]
The Linux kernel 110 is a kernel for controlling execution of a normal Linux application that does not require real-time performance, and is executed as a task with the lowest priority of the real-time kernel 120. Here, a non-real-time control unit in the Linux kernel 110 is a process.
[0042]
The real-time kernel 120 is a kernel for performing control that requires real-time performance, such as synchronization control of external hardware. Here, a real-time control unit in the real-time kernel 120 is a task.
[0043]
Referring to FIG. 4, the PDL analysis control process 111, job control process 112, operation unit control process 113, data flow control process 114, and HTTP server control are the processes in which the Linux kernel 110 performs non-real time control. There are a process 115, an ftp server control process 116, a telnet server control process 117, and a non-real-time overall control process 118.
[0044]
An outline of each of these processes will be described.
The PDL analysis control process 111 analyzes the PDL and creates an intermediate record.
[0045]
The job control process 112 controls jobs of various applications including print jobs.
[0046]
The operation unit control process 113 controls various data input from the operation unit 16 of the printer controller 10.
[0047]
The data flow control process 114 passes the intermediate record created in the PDL analysis control process 111 to the real-time kernel 120.
[0048]
The HTTP server control process 115, the ftp server control process 116, and the telnet server control process 117 control the Internet function.
[0049]
The non-real-time overall control process 118 performs management and control related to the entire non-real-time control.
[0050]
The processes 111 to 117 described above are application processes that do not require real-time processing, and are therefore performed equally.
[0051]
Still referring to FIG. 4, the real-time kernel 120 performs a real-time control as a real-time timer control task 121, a data flow control task 122, a paper feed control task 123, an image generation control task 124, and an image output. There are a control task 125, an engine communication control task 126, and a real-time overall control task 127.
[0052]
An outline of each of these tasks will be described.
The real-time timer control task 121 controls processing executed at a constant cycle in the millisecond range. Further, when the necessity of periodic processing occurs in other tasks, the real-time timer control task 121 is requested to perform the processing.
[0053]
The data flow control task 122 performs data transmission / reception control with a non-real time process.
[0054]
The paper feed control task 123 controls the paper feed process of the recording paper.
The image generation control task 124 performs control for converting the intermediate record into image data.
[0055]
The image output control task 125 performs control for transferring image data as a synchronization packet line by line in synchronization with the / HSYNC signal of the printer 20.
[0056]
The engine communication control task 126 controls the asynchronous communication mode for acquiring the / HSYNC signal cycle of the printer 20.
[0057]
The real-time overall control task 127 performs management related to the entire real-time control and synchronous control between real-time tasks. That is, the execution timing of each of the above-described tasks 121 to 126 is determined by the real-time overall control task 127.
[0058]
Next, the outline of the relationship between the process and task shown in FIG. 4 and the flowchart shown in FIG. 2 will be described.
[0059]
The print job received in step S101 in FIG. 2 is subjected to steps S103 and S104 by the PDL analysis control process 111 to interpret the PDL and create an intermediate record.
[0060]
The created intermediate record is transferred from the data flow control process 114 to the data flow control task 122 and is subject to real-time control.
[0061]
Next, steps S108 and S109 are executed for the intermediate record by the image generation control task 124 and the image output control task 125, and development into image data and output to the printer 20 are performed in parallel.
[0062]
FIG. 5 is a flowchart showing processing performed in the real-time overall control task 127.
[0063]
The real-time overall control task 127 is a process executed in step S109 in FIG. 2 before starting transmission of image data from the image output unit 17 to the printer 20.
[0064]
Referring to FIG. 5, first, the PDL analysis control process 111 acquires print control information of the print job that has been analyzed as a non-real time process (S201).
[0065]
The resolution specified for the print job is read from the print control information acquired in step S201 (S202).
[0066]
The designated resolution of the print job read in step S202 is compared with the resolution currently set in the printer 20 (S203).
[0067]
As a result of the comparison in step S203, if the specified resolution of the print job matches the resolution of the printer 20 currently set (Yes in S203), the / SYNC signal currently set in the printer 20 Period data is acquired (S204).
[0068]
As a result of the comparison in step S203, when the designated resolution of the print job does not match the currently set resolution of the printer 20 (No in S203), it corresponds to the resolution designated for the print job. Period data of the / HSYNC signal of the printer 20 is acquired (S205). The period data of the / HSYNC signal of the printer 20 is acquired by performing the IEEE1394 asynchronous transfer control by the engine communication control task 126.
[0069]
Based on the period data of the / HSYNC signal of the printer 20 acquired in step S204 or S205, the activation period parameter of the image output control task 125 is set (S206).
[0070]
The image output control task 125 is activated based on the activation cycle parameter set in step S206 (S207), and the image data is transferred to the printer 20 in accordance with the cycle of the / HSYNC signal.
[0071]
In the present embodiment, image data is isochronously transferred from the printer controller 10 to the printer 20 via the IEEE 1394 serial bus.
[0072]
In the real-time overall control task 127 described above, by setting a cycle parameter based on the cycle of the / HSYNC signal of the printer 20 corresponding to the resolution specified in the print job in step S206, the image output control task 125 of the printer controller 10 is set. Can be optimally set for the print job. As a result, the activation cycle of the image output control task 125 of the printer controller 10 based on the cycle of the / HSYNC signal of each printer 20 is determined. By transferring the image data based on the determined activation cycle, it is possible to realize an optimal print process. That is, the overhead in the print system 1 can be eliminated and efficient data transfer can be realized.
[0073]
In addition, although the case where RT-Linux which added real-time property to Linux of general-purpose OS was used as the OS of the printer controller 10 of the printing system 1 described above, the general-purpose OS is not limited to Linux. Absent.
[0074]
The communication between the printer controller 10 and the printer 20 is performed in the isochronous transfer mode using the IEEE1394 serial bus. However, the communication may be performed using a serial bus that performs other isochronous transfer.
[0075]
Furthermore, the data transfer method performed by the printer controller 10 of the print system 1 described above can be provided as a program. Such a program is a computer-readable program.
[0076]
The program may be recorded on a recording medium such as a flexible disk attached to the computer, a CD-ROM, a ROM, a RAM, and a memory card, and provided as a program product. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network.
[0077]
The provided program product is installed in a program storage unit such as a hard disk and executed.
[0078]
The program product includes the program itself and a recording medium on which the program is recorded.
[0079]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a print system 1 according to an embodiment.
FIG. 2 is a flowchart illustrating print processing in the printer controller.
FIG. 3 is a diagram illustrating timings of various signals related to the operation of the printer 20 when printing for one page.
FIG. 4 is a diagram illustrating a specific example of the firmware configuration of the printer controller 10 in the present embodiment.
FIG. 5 is a flowchart showing processing performed in a real-time overall control task 127;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Print system, 10 Printer controller, 11 Printer controller CPU, 12 Printer controller ROM, 13 Printer controller RAM, 14 Communication I / F, 15 HDD, 16 Operation unit, 17 Image output unit, 20 Printer, 21 Printer CPU, 22 Printer ROM, 23 Printer RAM, 24 Image input unit, 25 Engine unit, 26 Scanner control unit, 27 High pressure control unit, 28 Laser control unit, 29 Transport control unit, 110 Linux kernel, 111 PDL analysis control process, 112 job control process, 113 operation unit control process, 114 data flow control process, 115 HTTP server control process, 116 ftp server control process, 117 telnet server control process, 118 non-real time Overall control process, 120 real-time kernel, 121 real-time timer control tasks, 122 data flow control tasks, 123 feed control tasks, 124 image generation control task, 125 an image output control task, 126 engine communication control task, 127 real-time overall control tasks.

Claims (7)

A printer controller for transferring image data to a printer,
Control means for executing a general-purpose OS ( Operating System ) with a real-time function ;
A task that is controlled by the real-time capabilities of the general purpose OS executed by the control unit, and data output means for outputting the image data of a predetermined amount to the previous SL printer,
Periodic data acquisition means for acquiring periodic data relating to print processing of the printer;
A data output cycle , which is a task controlled by the real-time function of the general-purpose OS executed by the control means, and sets a start cycle of the data output means based on the periodic data acquired by the periodic data acquisition means A printer controller comprising setting means. Image data resolution recognition means for recognizing the resolution of the image data,
The printer controller according to claim 1, wherein the periodic data acquisition unit acquires periodic data related to print processing according to the image data resolution recognized by the image data resolution recognition unit.   The said printer is a laser beam type printer, The period data acquired by the said period data acquisition means is the period of the horizontal synchronizing signal in the writing of the laser beam of the said laser beam type printer. Printer controller. The periodic data acquisition unit is a task that is controlled in real time by a real-time function of the general-purpose OS executed by the control unit, and acquires the periodic data from the printer. Printer controller. A transfer method performed by a printer controller for transferring image data to a printer,
The printer controller includes a control unit that executes a general-purpose OS to which a real-time function is added.
A periodic data acquisition step of acquiring periodic data related to print processing of the printer;
A data output period setting step that is controlled by the real-time function of the general-purpose OS executed by the control means and sets the period of outputting the image data based on the period data acquired in the period data acquisition step ;
A data transfer method comprising: a data output step that is controlled by the real-time function of the general-purpose OS executed by the control means and outputs the image data to the printer at a cycle set in the data output cycle setting step. . A general-purpose OS program to which a real-time function is added, which causes a computer to function as a printer controller that transfers image data to a printer ,
The program is stored in the printer controller.
A task that is controlled by the real-time capabilities of the general purpose OS, and a data output step of outputting the image data of a predetermined amount to the previous SL printer,
A periodic data acquisition step of acquiring periodic data related to print processing of the printer;
A task that is controlled by the real-time capabilities of the general purpose OS, the startup period of the data output step, to perform the data output period setting step of setting, based on period data acquired by the periodic data acquiring step , Data transfer program. A computer-readable recording medium on which the data transfer program according to claim 6 is recorded.

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