JP5162515B2 - Image processing device - Google Patents

Description

  The present invention relates to an image processing apparatus that reads image data representing an image of a document and executes at least a copy process for forming an image represented by the read image data on a recording medium.

  In Japanese Patent Application Laid-Open No. 2004-228561, a full color copying machine is exemplified as an image processing apparatus. This type of full-color copying machine includes an image forming area for forming black, cyan, magenta, and yellow images on a conveyance belt. In each of these image forming areas, black, cyan, magenta, and yellow images are formed on the conveyance belt. As a result, a full color image is formed on the transport belt. The full-color image formed on the transport belt in this way is transferred and fixed on the transfer paper transported on the transport belt. Through such processing, a full color image is transferred onto the transfer paper.

  Such a full-color copying machine may be provided with a scanner that reads image data representing an image of a document. In this type of full-color copying machine, an image represented by image data read by a scanner is transferred to a transfer sheet. A process in which image data representing an image is read by the scanner and an image represented by the read image data is formed on the transfer paper is called a copy process.

  When such copy processing is executed, software processing as described below is performed in the image processing apparatus. When an operation for instructing execution of copy processing is performed, the control unit causes the kernel to generate a thread to which a function for driving the scanner and a thread to which a function for driving the printer are allocated. Then, each of these threads is being executed, and each of the scanner and the printer is driven. Copy processing is realized by the processing described above. The kernel is a program module that forms the core of the operating system.

JP 2004-178387 A

  Recently, there has been a demand for faster copy processing. The time required for platen color copying, which is an example of such copying processing, is preferably 6.3 s, for example. Here, the platen color copy is a process of reading color image data representing a color image of a document placed on a document table and forming a color image represented by the color image data on a recording medium.

  However, of the time required for platen color copying, the time during which the printer is actually driven by the image forming device driver for starting the printer and forming an image on a recording medium is fixed to some extent. As described above, it has been found by the inventors' experiment that the time during which the printer is actually driven is 6.15 s. For this reason, the time during which the printer is actually driven becomes a bottleneck for reducing the time required for platen color copying.

  Therefore, if the time during which the printer is actually driven is shortened, the time required for the copy process is shortened. However, it can be seen that it is difficult to reduce the actual driving time of the printer for the following reason. As a method for shortening the time during which the printer is actually driven, for example, the image forming speed of the printer can be improved. However, for this purpose, it is necessary to improve the hardware configurations of the scanner and the printer without deteriorating the image reading accuracy and the image forming accuracy.

  Also, as a pre-process until the image represented by the image data actually read by the scanner starts to be formed on the recording medium after the printer starts driving, the image data read by the scanner is stored in a file in the operating system. It must be stored in the system. At that time, a certain amount of time (for example, 200 ms) is required for communication between tasks performed by a task of reading image data by a scanner and a task of storing image data in a file system in the operating system.

  As described above, it is necessary to improve the hardware configuration of the scanner and the printer without deteriorating the image reading accuracy and the image forming accuracy, and the task of reading the image data by the scanner and the operating system A certain amount of time is required for communication between tasks performed by the task of storing image data in the internal file system. Therefore, it is difficult to shorten the time that the printer is actually driven.

  Therefore, in order to shorten the time required for the copy process, it is desirable to shorten the time from when the start key is operated until the printer is activated. Such a time is desirably a time within 150 ms, for example.

  By the way, it is known that the kernel has a function of dynamically changing the priority of a newly generated thread. Such a function is a function normally provided in a general-purpose operating system such as Linux (registered trademark). Therefore, even when the priority of the thread is set high by the user when the thread is generated, the priority of the thread may be lowered. In that case, a certain amount of time is required until the newly generated thread transitions to the running state.

  According to the experiment by the present inventor, it has been found that it takes 200 ms from the generation of the thread assigned the function for driving the scanner to the transition to the running state. As described above, the time required from the generation of the thread assigned the function for driving the scanner to the transition to the running state is the time from when the start key is operated until the printer is started. include. For this reason, it has been found that it is difficult for the conventional image processing apparatus to set the time from when the start key is operated to when the printer is activated to within 150 ms.

  The present invention has been made to solve the above-described problem, and shortens the timing at which image data representing an image is started to be read by a scanner after a copy process is requested. Therefore, an object of the present invention is to provide an image processing apparatus capable of reducing the time required for the copy process.

  An image processing apparatus according to an aspect of the present invention reads image data representing an image of a document and executes a copy process for forming an image represented by the read image data on a recording medium, and the control A process of generating a pause thread that is not executed by the unit, a process of increasing the priority of the pause thread as the time elapsed since the pause thread was generated and not being executed by the control unit, and the priority is An operating system that performs a process of assigning a process for assigning a process executed by the control unit to the high sleep thread, and the control unit performs in advance as a pre-process before executing the copy process. The copy processing is executed by causing the operating system to generate the pause thread. In doing so, the image data reading thread representing the process of reading the image data is assigned to the operating system, the process of reading the image data assigned to the sleep thread having the higher priority. And executing the image data reading thread (claim 1).

  According to this configuration, a sleep thread that is not executed by the control unit is generated in advance before the copy process is executed. The priority of such a sleep thread is increased by the operating system as the time that has passed without the execution of the control thread from the generation of the sleep thread becomes longer. In addition, a process executed by the control unit is preferentially assigned by the operating system to the sleep thread having a high priority.

  Therefore, when the copy process is executed, a process for reading image data by the operating system is assigned to a sleep thread having a high priority. Accordingly, the sleep thread assigned as the image data reading thread to which the process for reading the image data is assigned has a high priority, and therefore transitions to a preferentially executed state.

  Accordingly, the time from the start of the copy process to the state in which the control unit can execute the image data reading thread assigned with the process of reading the image data is shortened. For this reason, it is possible to shorten the timing at which reading of image data representing an image by a scanner is started after a copy process is requested by a simple method, thereby reducing the time required for the copy process. can do.

  In the above-described configuration, the control unit can execute the image data reading thread when the control unit performs processing for causing the sleep thread to be the image data reading thread with respect to the operating system. A delay time indicating a time until a state is reached, and the operating system controls the image data reading thread until the delay time elapses after the sleep thread is set as the image data reading thread. When the delay time elapses, the image data reading thread can be in a state in which the control unit can execute it.

  According to this configuration, the control unit can execute the image data reading thread when the delay time has elapsed since the sleep thread is set as the image data reading thread. Therefore, before the delay time elapses, it is possible to allocate a different process to a thread other than the sleep thread that is set as the image data reading thread and to enable the control unit to execute. Therefore, in the control unit, it is possible to prevent the process represented by the image data reading thread from competing with the process represented by another thread.

  In the above configuration, the control unit performs processing for generating a plurality of the sleep threads for the operating system in the preprocessing, and performs the copy processing during the delay time. , Assigning the operating system a process for forming the image on the recording medium to the sleep thread having the second highest priority after the sleep thread set as the image data reading thread. The image forming thread may be executed by performing a process for causing the image forming thread to represent the process for forming the image on the recording medium.

  According to this configuration, the priority is next to the sleep thread that is set as the image data reading thread until a delay time elapses when the control unit cannot execute the image data reading thread. A high pause thread is used as an image forming thread. The image forming thread is executed by the control unit until the delay time elapses.

  For this reason, after the execution of the copy process is started, an image forming thread is first executed in the control unit. Thereafter, an image data reading thread is executed in the control unit. Therefore, in the copy process, a smooth processing sequence is realized in which the printer is activated and then the scanner is activated.

  In the above configuration, the delay time is preferably within a range of 100 msec to 200 msec. When the delay time is within this range, a series of processing sequence of printer activation and scanner activation is particularly smooth in the image processing apparatus.

  In the above configuration, the image reading device driver for reading the image data drives the image reading unit for reading the image data, and the image forming device driver for forming the image on the recording medium. And an image forming unit that forms an image represented by the image data on the recording medium. According to this configuration, since the image reading unit that reads the image data and the image forming unit that forms the image on the recording medium are further provided, a copying machine that can achieve the effects of claims 1 to 4 is provided.

  According to the present invention, the time from when the copy process is started until the control unit can execute the image data reading thread to which the process of reading the image data is assigned is shortened. For this reason, it is possible to shorten the timing at which reading of image data representing an image by a scanner is started after a copy process is requested by a simple method, thereby reducing the time required for the copy process. can do.

1 is a schematic sectional view of a copying machine according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating an example of a functional module of a copier according to an embodiment of the present invention. It is the flowchart which showed roughly the process by the side of the control part at the time of a thread pool being produced | generated. 6 is a flowchart schematically showing processing on the kernel side when a thread pool is generated. It is the flowchart which showed roughly the process by the side of a control part at the time of a copy process being performed. It is the flowchart which showed roughly the process by the side of a kernel at the time of a copy process being performed.

  Hereinafter, an image processing apparatus according to an embodiment of the present invention will be described. The image processing apparatus according to the present embodiment is a copying machine. Note that the image processing apparatus according to the present invention may be a facsimile machine or a multifunction machine having a copying function.

  FIG. 1 is a schematic sectional view of a copying machine according to an embodiment of the present invention. In FIG. 1, a tandem type copying machine 1 is illustrated as an image processing apparatus according to an embodiment of the present invention. However, the image processing apparatus according to the present invention may be an intermediate transfer belt type copying machine.

  The copier 1 shown in FIG. 1 reads an original and generates image data representing an image of the original, and an image reading unit (image reading unit) 7, and an image represented by the image data read by the image reading unit 7. A main body unit 2 to be transferred to a recording paper (recording medium) P, and a recording paper discharge unit 6 from which the recording paper to which the image represented by the image data is transferred in the main body unit 2 are discharged.

  The image reading unit 7 includes a scanner 71 configured by a CCD (Charge Coupled Device) or the like. The image reading unit 7 reads the document placed on the document table 72 by the scanner 71 and generates image data of the document. Further, the image reading unit 7 sequentially sends out a plurality of documents stacked on the document placing unit 73 onto the reading window 74, and causes the scanner 71 to read the document at the position of the reading window 74 and image data of the document. Is generated.

  The main body 2 includes a paper feeding unit 10, an image forming unit 30, a transfer conveyance unit 40, a fixing unit 50, a recording paper conveyance unit 20, and a control unit 9. The paper feeding unit 10 has a stack of recording papers P stacked on a paper feeding cassette. The recording paper P stacked on the paper feeding cassettes is fed one by one from the uppermost recording paper P to the recording paper transport unit 20. Paper is fed to the most downstream part of the paper.

  The recording paper transport unit 20 passes the recording paper P fed from the paper feeding unit 10 to the most downstream portion through the image forming unit 30 and the transfer transport unit 40 and the fixing unit 50 in this order by various roller pairs. Then, the recording paper is conveyed to the recording paper discharge unit 6 provided in the vicinity of the most downstream portion of the recording paper conveyance unit 20.

  The image forming unit 30 multiplexly forms a plurality of toner images on the recording paper P passed by the recording paper transport unit 20. The image forming unit 30 includes a first image forming unit 30M that forms a magenta toner image, a second image forming unit 30C that forms a cyan toner image, and a third image forming unit 30Y that forms a yellow toner image. , And a fourth image forming unit 30K that forms a black toner image. The image forming units 30M, 30C, 30Y, and 30K are arranged in this order in the image forming unit 30 at predetermined intervals along the direction in which the recording paper P is conveyed.

  Each of the image forming units 30M, 30C, 30Y, and 30K includes a photosensitive drum 31, a charging unit 32, a developing unit 34, and a cleaning unit 35, respectively. The charging unit 32, the developing unit 34, and the cleaning unit 35 are all disposed so as to face the peripheral surface of the photosensitive drum 31. The charging unit 32 charges the photosensitive drum 31. The exposure unit 33 forms a latent image on the charged photosensitive drum 31. The developing unit 34 develops the toner by attaching toner to the formed latent image, and forms a toner image on the peripheral surface of the photosensitive drum 31. The toner image formed on the peripheral surface of the photosensitive drum 31 in this way is transferred to the recording paper P that is conveyed to the transfer conveying unit 40 and passed through the position of the photosensitive drum 31. The cleaning unit 35 removes the toner remaining on the peripheral surface of the photosensitive drum 31.

  The developing unit 34 includes a toner storage unit 341. The toner storage portions 341 of the image forming units 30M, 30C, 30Y, and 30K store toners of magenta, cyan, yellow, and black, respectively. The developing unit 34 of each of the image forming units 30M, 30C, 30Y, and 30K develops the latent image formed on the photosensitive drum 31 using the toner stored in its own toner storage unit 341. Accordingly, each developing unit 34 forms a toner image of each color of magenta, cyan, yellow, and black on each photoconductive drum 31. Thus, the toner image formed on each photoconductive drum 31 is transferred to the recording paper P when the recording paper P is conveyed by the transfer belt 41.

  The transfer conveyance unit 40 includes a driven roller 42, a driving roller 43, an endless transfer belt 41 disposed between the driven roller 42 and the driving roller 43, and four transfer rollers 44. In each of the image forming units 30M, 30C, 30Y, and 30K, each of the four transfer rollers 44 is provided in the vicinity of the photosensitive drum 31 and is provided to face the photosensitive drum 31.

  The transfer conveyance unit 40 conveys the recording paper P conveyed by the recording paper conveyance unit 20 along the image forming units 30M, 30C, 30Y, and 30K. When the recording paper P passes through the transfer nip formed between the photosensitive drum 41 and the transfer roller 44 in each of the image forming units 30M, 30C, 30Y, and 30K, the recording paper P is transferred to the photosensitive drum 41. The formed toner images of respective colors are transferred. The transfer conveyance unit 40 conveys the recording paper P onto which the toner images of the respective colors have been transferred in the image forming units 30M, 30C, 30Y, and 30K to the fixing unit 50.

  The fixing unit 50 heats the recording paper carried in by the transfer conveyance unit 40, whereby the toner images previously transferred onto the recording paper by the four image forming units 30M, 30C, 30Y, and 30K are recorded on the recording paper. To settle.

  The toner storage units 341 of the image forming units 30M, 30C, 30Y, and 30K respectively include sensors SM, SC, SY, and SK that detect the remaining amount of toner stored in the toner storage unit 341. The remaining amounts of magenta, cyan, yellow, and black toners stored in the toner storage units 341 of the image forming units 30M, 30C, 30Y, and 30K are detected. The control unit 9 is constituted by a CPU, a microprocessor, and the like, and comprehensively controls the copying machine 1.

  FIG. 2 is a block diagram showing an example of a functional module of the copying machine according to the embodiment of the present invention. In FIG. 2, the copying machine 1 includes a control unit 9, a scanner 71, an image forming unit 30, an operation unit 5, and a storage unit 67. In the following description, the same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

  In such a copying machine 1, the control unit 9 is based on a control program 100 stored in a ROM (not shown) or the storage unit 67 in accordance with various instruction signals input from the user to the operation unit 5. The processing is executed, and the copier 1 is controlled in an integrated manner by outputting an instruction signal to each functional unit, transferring data, and the like.

  The operation unit 5 is used for a user to perform operations related to a copy function, a printer function, a scanner function, and the like, and gives an operation command (command) or the like by the user to the control unit 9. The operation unit 5 also includes a start key 51 that is operated by the user to cause the copying machine 1 to perform a copy process.

  The storage unit 67 stores a storage unit that stores image data generated by the scanner 71, a destination name or a facsimile number for registration of a shortened button when performing facsimile communication, or a transmission destination when used as a network scanner. The storage unit stores the IP address and the like in advance.

  The storage unit 67 stores a control program 100 including at least the copy processing module 101. As described above, the control program 100 including the copy processing module 101 is a program positioned above the operating system 102. The control unit 9 executes a copy process using the copy process module 101. Then, the control unit 9 uses the copy processing module 101 to generate a thread pool 106 for storing the threads generated by the thread generation module 107.

  Here, in the copy process, the scanner 71 reads the document placed on the document table 72 and generates image data of the document (or the document that the scanner 71 sequentially sends out from the document placement unit 73 to the reading window 74. Is read at the position of the reading window 74 to generate image data), the image forming unit 30 forms the image represented by the image data on the recording paper P, and the image transferred to the recording paper P This is a series of processes consisting of processes fixed by the fixing unit 50.

  The storage unit 67 stores an operating system 102. An example of such an operating system 102 is Linux (registered trademark) which is a general-purpose operating system. The operating system 102 includes a scanner driver (image data reading device driver) 103, a printer driver (image forming device driver) 104, and a kernel 105.

  In the operating system 102, a scanner driver (image reading device driver) 103 is a program module for driving the image reading unit 7 (mainly the scanner 71) to read image data. The printer driver (image forming device driver) 104 activates the image forming unit 30 and the fixing unit 50 to transfer the image represented by the image data to the recording paper P, and the image transferred to the recording paper P is transferred to the recording paper P. It is a program module for fixing. The scanner driver 103 and the printer driver 104 are program modules positioned above the kernel 105.

  The kernel 105 is a program module that is a core part of the operating system 102. The kernel 105 includes a system call interface 106, a thread generation module 107, a scheduling module 108, and a thread management module 109. The system call interface 106 serves as a window for a system call output to the kernel 105, and provides a transition mechanism between the program module positioned above the kernel 105 and the kernel 105.

  The thread generation module 107 is a program module that generates various threads when the kernel 105 receives a thread generation request from the control unit 9 and stores them in a memory (not shown) managed by the kernel 105. . Here, the thread represents a process executed by the control unit 9, and includes, for example, an address of a memory storing a program module to be executed by the control unit 9 and a local variable. In the present embodiment, the thread generation module 107 generates a pause thread that is not executed by the control unit 10 and stores it in the memory.

  The scheduling module 108 causes each of the threads generated by the thread generation module 107 to transition to a state that can be executed by the control unit 9 in order from the thread with the highest priority to the thread with the lowest priority. In other words, the scheduling module 108 causes each of the threads to transition from the standby state to the executing state in the order of priority from the thread with the highest priority.

  The thread management module 109 monitors the time that has not been executed by the control unit 9 since the thread generation module 107 generated the thread. The priority of the corresponding thread is increased as the elapsed time becomes longer. Then, the priority of the thread is stored. Therefore, the priority of the thread can be different from the priority set in advance by the user.

  The storage unit 67 stores the thread pool 106. The thread pool 106 is configured to store thread identification information 106A of a thread and information 106B indicating a usage state. Here, the thread identification information 106A is stored when the thread pool 106 is generated. On the other hand, in the information 106B indicating the use state, information indicating “in use” is stored when the identification information of the thread that is in the execution state when the copy process is executed is received from the kernel 105. Information indicating “not in use” is stored when the thread is in a sleep state or an execution wait state.

  Such a thread pool 106 is generated by the following procedure. As an operating system 102 that can generate the thread pool 106 by the following procedure, Linux (registered trademark) (version 2.6), which is a general-purpose operating system, is known.

  FIG. 3 is a flowchart schematically showing processing on the control unit 9 side when the thread pool 106 is generated. FIG. 4 is a flowchart schematically showing processing on the kernel 105 side when the thread pool 106 is generated. As described above, it is desirable that the process for generating the thread pool 106 be performed when the power of the copying machine 1 is turned on, for example.

  As shown in FIG. 3, the control unit 9 requests the kernel 105 to generate a sleep thread to which a function for maintaining a sleep state is assigned (step S1). The processing shown in step S1 is realized by using, for example, the system call “clone ()” and the system call “sleep”. And the control part 9 memorize | stores the identification information of the said thread | sled in the thread pool 106 (step S2). The controller 9 repeats the processing shown in steps S1 and S2 until the number of sleep threads that have requested generation reaches a predetermined number (N) (step S3).

  On the other hand, as shown in FIG. 4, the kernel 105 is executed by the control unit 9 every time the control unit 9 requests generation of a sleep thread to which a function for maintaining the sleep state is assigned (YES in step S10). A sleep thread to which a function that is not performed is assigned is generated (step S11), and the generated sleep thread is stored in the memory (step S12).

  The thread pool generation process described above is performed from the viewpoint of enabling the sleep thread to be an image data reading thread (hereinafter referred to as a scanner driving thread) immediately after the copy process is executed. It is desirable to be executed when the power is turned on.

  As described above, the thread management module 109 increases the priority of the sleep thread prepared prior to the copy process, compared to a thread newly generated during the copy process. Therefore, the copying machine 1 can execute the copy process shown below. FIG. 5 is a flowchart schematically showing processing on the control unit 9 side when copy processing is executed. FIG. 6 is a flowchart schematically showing processing on the kernel 105 side when copy processing is performed. Here, Linux (registered trademark) (version 2.6), which is a general-purpose operating system, is known as an operating system 102 that can execute copy processing according to the following procedure.

  When the start key 51 is operated, the control unit 9 performs the following process (step S21) as shown in FIG. That is, as shown in step S <b> 21, the control unit 9 instructs the kernel 105 to set the sleep thread having the highest priority among the sleep threads managed by the kernel 105 as the scanner driving thread. At this time, the control unit 9 determines a delay time (for example, 100 ms) from when the pause thread is set as a scanner driving thread until the scanner driving thread can be executed by the control unit 9. Specify.

  The process shown in step S21 is realized by using, for example, a memory address in which a program module constituting the scanner driver 103 is stored and a system call “nanosleep ()”.

  After that, the control unit 9 instructs the kernel 105 to set a pause thread having the second highest priority among pause threads managed by the kernel 105 as an image forming thread (hereinafter referred to as a printer driving thread). This is performed (step S22). Such processing shown in step S22 is realized by using, for example, a memory address in which a program module constituting the printer driver 104 is stored.

  Then, the control unit 9 drives the printer by executing a printer driving thread that can be executed by the kernel 105. Next, the control unit 9 drives the scanner by executing a scanner driving thread that can be executed by the kernel 105. The processing of the control unit 9 shown above is performed by the copy processing module 101.

  On the other hand, as shown in FIG. 6, the kernel 105 receives an instruction from the control unit 9 to set the sleep thread with the highest priority as a scanner driving thread (YES in step S30). Then, the scheduling module 108 refers to the priority stored in the thread management module 109 to determine the sleep thread with the highest priority (step S31). Then, the scheduling module 108 sets the sleep thread with the highest priority as a scanner driving thread (step S32). The process shown in step S32 is realized, for example, by assigning a memory address notified by the control unit 9 and storing a program module constituting the scanner driver 103 to a sleep thread. Then, the scheduling module 108 sets the scanner driving thread in a standby state for a specified delay time (for example, 100 ms). As described above, the scanner driving thread is in a standby state for the delay time, and therefore, the controller 9 cannot execute the scanner driving thread until the delay time elapses.

  Next, the kernel 105 receives an instruction from the control unit 9 to set the sleep thread having the second highest priority as a printer driving thread (YES in step S33). Then, the scheduling module 108 refers to the priority stored in the thread management module 109 and determines a suspended thread having the second highest priority (step S34). Then, the scheduling module 108 sets the pause thread having the second highest priority as a printer driving thread (step S35). The process shown in step S35 is realized by, for example, allocating the memory address notified by the control unit 9 and storing the program module constituting the printer driver 104 to the sleep thread.

  The scheduling module 108 is in a state in which the image data reading thread consisting of the sleep thread with the highest priority is in the standby state, and is executing the printer driving thread consisting of the sleep thread with the next highest priority. (Step S36). At this time, the controller 9 can execute the printer driving thread.

  Then, when the delay time has elapsed since the thread having the highest priority is set as the scanner driving thread (YES in step S37), the scheduling module 108 sets the scanner driving thread to the executing state (step S38). ). At this time, the controller 9 can execute the scanner driving thread.

  As described above, in the copying machine 1, when the copying process is started, first, the scanner driving thread is in a waiting state while the printer driving thread is in an executable state. Then, when the delay time elapses after the scanner driving thread enters the execution waiting state, the scanner driving thread becomes executable. Therefore, when the copy process is executed, a series of processing sequences in which the printer is activated and then the scanner is activated become smooth. The delay time is preferably in the range of 100 ms to 200 ms. When the delay time is within this range, a series of processing sequences in which the printer is activated and then the scanner is activated when the copy process is executed are particularly smooth. In particular, when the delay time is 100 ms, the series of processing sequences becomes smoother.

DESCRIPTION OF SYMBOLS 1 Copy machine 7 Image reading part 9 Control part 30 Image formation part 102 Operating system 103 Scanner driver 104 Printer driver P Recording paper

Claims (5)

A control unit that reads image data representing an image of a document and executes a copy process for forming an image represented by the read image data on a recording medium;
A process for generating a sleep thread that is not executed by the control unit;
A process of increasing the priority of the paused thread as the time elapsed without being executed by the control unit since the paused thread is generated, and
An operating system that performs a process of allocating a process of allocating a process to be executed by the control unit to the suspended thread having a high priority;
With
The controller is
As pre-processing before executing the copy processing, processing for generating the sleep thread for the operating system is performed in advance.
When executing the copy process, the process of reading the image data is assigned to the sleep thread having a high priority to the operating system, and the sleep thread represents the process of reading the image data. An image processing apparatus that performs a process for setting an image data reading thread and executes the image data reading thread. The controller is
A delay that represents a time until the control unit can execute the image data reading thread when the operating system performs processing for setting the sleep thread as the image data reading thread. Set the time,
The operating system is
Until the delay time elapses after the sleep thread is set as the image data reading thread, the control unit cannot execute the image data reading thread, and when the delay time elapses, The image processing apparatus according to claim 1, wherein the control unit can execute the image data reading thread. The controller is
In the preprocessing, the operating system is caused to generate a plurality of the sleep threads,
When performing the copy process,
During the delay time, the operating system is assigned processing for forming the image on the recording medium to the sleep thread having the second highest priority after the sleep thread used as the image data reading thread. 3. The image processing according to claim 2, wherein the image processing thread is executed by performing a process of causing the pause thread to be an image forming thread representing a process of forming the image on the recording medium. apparatus.   The image processing apparatus according to claim 3, wherein the delay time is in a range of 100 msec to 200 msec. An image reading unit that is driven by an image reading device driver for reading the image data and reads the image data;
An image forming unit that drives the image forming device driver for forming the image on the recording medium and forms an image represented by the image data on the recording medium;
The image processing apparatus according to claim 1, further comprising:

Images