JP5986963B2 - Image reading apparatus and image forming apparatus having the same - Google Patents

Description

  The present invention relates to an image forming apparatus including a large-capacity magnetic storage device.

  A large-capacity magnetic storage device such as an HDD may be used for data storage. The magnetic storage device is provided with a magnetic disk (storage medium) for storing data and a magnetic head for reading and writing data on the magnetic disk. In such a magnetic storage device, when an impact is applied and vibration occurs, the magnetic head may hit the magnetic disk and damage the magnetic disk. The data of the damaged part is damaged, and an error occurs when reading / writing is performed on the damaged part. Therefore, when an impact or vibration is detected, the magnetic head may be retracted from the magnetic disk. Patent Document 1 discloses a technique for retracting such a magnetic head.

  Specifically, Patent Document 1 discloses a hard magnetic disk that moves and moves a magnetic head, a file system, a detector (acceleration sensor 570) that predicts the generation of external force such as vibration and impact, and the detector generates external force. Detecting the possibility of a head, the head evacuation means urgently stops access by evacuating the magnetic head from the recording area of the magnetic disk, and the magnetic head evacuation is detected to stop the file system operation and fail to evacuate the magnetic head The magnetic disk access holding means for controlling the execution of the stored magnetic disk access again (when the detector detects that the possibility of the occurrence of external force has been lost) A recording / reproducing apparatus provided with an HDD transfer control unit 140) is described. In this recording / reproducing apparatus, the HDD cache 121 is returned to the previous state in order to re-execute the access being executed at the time of emergency evacuation of the magnetic head, and waits until it returns to a safe accessible state (Patent Document 1). : Claim 1, paragraphs [0021], [0051] etc.).

Japanese Patent Laid-Open No. 2004-199743

  An image forming apparatus may also be equipped with a magnetic storage device. In an image forming apparatus, a magnetic storage device may be used as a temporary storage destination of image data used for printing. The image data temporarily stored (written) in the magnetic storage device is read from the magnetic storage device at the timing when the image data is necessary for printing.

  Here, in order to avoid problems such as failure and data corruption, it is preferable to retract the magnetic head even in the magnetic storage device mounted in the image forming apparatus when there is an impact or vibration. However, while the magnetic head is being retracted, the magnetic storage device is in a state where reading and writing cannot be performed. For this reason, there is a case where the image data cannot be read at the timing at which the image data should be read because a delay occurs in reading the image data when the magnetic head is retracted. In this case, there is a problem that the image data is not in time for printing, and printing may be interrupted.

  Here, in the technique described in Patent Document 1, when the occurrence of external force such as vibration or impact is predicted, the magnetic head is always retracted, and further, when detecting that the detector has determined that the possibility of external force generation has disappeared, The stored magnetic disk access is always re-executed. Therefore, when the technique of Patent Document 1 is applied to an image forming apparatus, image data cannot be read at all from the prediction of external force generation until the possibility of external force generation disappears, and printing is interrupted due to a delay in reading image data. Occurs whenever an external force is generated. Therefore, the technique described in Patent Document 1 has a great disadvantage when applied to an image forming apparatus, and the above problem cannot be solved.

  In view of the above-described problems of the prior art, the present invention reads image data without delay and does not interrupt printing even when an impact or vibration is applied to the image forming apparatus.

In order to achieve the above object, an image forming apparatus according to claim 1 is a data input unit for inputting data used for printing to the image forming apparatus, and an impact which is an operation for generating an impact on the image forming apparatus. An image based on data input from the data input unit, including a detection unit for detecting that an operation has been performed and a shock generation preliminary operation that is a preliminary operation of the impact operation, and a semiconductor element memory A semiconductor storage device that stores data in a nonvolatile manner, a magnetic disk, and a magnetic storage device that stores the image data in a nonvolatile manner, including a magnetic head for reading and writing data to and from the magnetic disk, and the magnetic storage Or a print engine unit that performs printing based on the image data read from the semiconductor memory device, the semiconductor memory device, and the magnetic memory. A control unit that controls reading and writing of the device, wherein the control unit includes a first time period that includes a period from when the shock generation preliminary operation is detected to when the shock operation is detected in the semiconductor memory device. Then, the image data to be transmitted to the print engine unit is stored, and then the image data is read, and in the second time zone that is a time zone excluding the first time zone, the magnetic storage device The image data is stored, and then the image data is read out. In addition, when the shock generation preliminary operation is detected, the control unit causes the semiconductor storage device to copy the image data stored in the magnetic storage device before the shock generation preliminary operation from the magnetic storage device. In the copying, the shortest time from the detection of the shock generation preliminary operation to the detection of the shock operation, starting from the page written in the magnetic storage device at the time of the shock generation preliminary operation in the semiconductor storage device The image data corresponding to the number of pages within a range that can be copied within a predetermined reference time is copied, and the image data copied by the semiconductor memory device instead of the magnetic memory device is read in the first time zone. When the second time zone is reached, the image data of the portion copied to the magnetic storage device is read out.

  Conventionally, magnetic storage for writing and reading of image data used for printing (temporary storage so that image data can be supplied to the print engine unit when necessary for printing and reading of image data in accordance with printing) When using an apparatus, if there is an impact or vibration, printing may be interrupted due to a magnetic head retraction or a read / write error. However, according to the present invention, a semiconductor memory device that is more resistant to shock and vibration than a magnetic memory device is mounted. Then, while it is predicted that an impact or vibration will be applied to the image forming apparatus, the semiconductor memory device is used for reading and writing image data. Thereby, the image data can be read without delay even if there is an impact or vibration. Therefore, it is possible to provide an image forming apparatus in which printing is not interrupted even when there is an impact or vibration.

1 is a diagram illustrating a multifunction machine. FIG. 2 is a block diagram illustrating a hardware configuration of a multifunction machine. It is a figure which shows a data input part. It is a figure for demonstrating temporary storage of image data. It is a figure for demonstrating reading of the compression image data temporarily saved. FIG. 10 is a timing chart for explaining a change in a temporary storage destination of image data accompanying an impact generation preliminary operation and an impact operation. FIG. It is a flowchart which shows the flow of change of the temporary preservation | save destination of the image data accompanying a shock generation preliminary operation and a shock operation. It is a timing chart for explaining reading of image data accompanying a shock generation preliminary operation and a shock operation. It is a flowchart which shows the flow of read-out according to impact generation preliminary operation and impact operation.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the following description, the multifunction peripheral 100 (corresponding to an image forming apparatus) will be described as an example. However, each element such as configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example.

(Configuration of MFP 100)
First, an outline of the multifunction peripheral 100 according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating the multifunction peripheral 100.

  As shown in FIG. 1, the multifunction peripheral 100 of the present embodiment is provided with a document reading unit 1 (corresponding to a data input unit) at the top. As shown in FIG. 1, the MFP 100 includes a paper feed unit 3 a, a conveyance unit 3 b, an image forming unit 4 a, and a fixing unit 4 b as the print engine unit 2. Further, an operation panel 3 for performing various settings related to the multifunction device 100 is provided in front of the multifunction device 100.

  The document reading unit 1 includes an image reading unit 1a and a document conveying unit 1b. The document conveying section 1b automatically and continuously conveys the documents placed on the document tray 12 one by one toward the conveyance reading contact glass 11a (reading position). The document conveying unit 1b is attached to the image reading unit 1a so that it can be opened and closed in the vertical direction with the back side of the paper in FIGS. 1 and 2 as a fulcrum, and functions as a plate for pressing each contact glass from above.

  The image reading unit 1a includes a conveyance reading contact glass 11a for reading a conveyed document and a placement reading contact glass 11b for reading a placed document. Further, the image reading unit 1a includes optical system members such as a lamp 13 (see FIG. 3), a mirror (not shown), a lens (not shown), and an image sensor 14 in a casing. The light emitted from the lamp 13 strikes the original on each contact glass, and the reflected light is reflected by each mirror and guided to a lens (not shown) i. A lens (not shown) collects the reflected light and enters the image sensor 14.

  The operation panel 3 accepts settings for a job to be executed. The MFP 100 according to the present embodiment includes a copy function (copy job) for printing based on data obtained by reading a document, and a transmission function (transmission job) for storing data obtained by reading a document in any location. ) And a box function that uses image data stored in the storage unit 7 (see FIG. 4) of the multi-function device 100. The operation panel 3 accepts various settings for these functions (jobs). The operation panel 3 is also provided with a key such as a start key 30 for instructing the start of a copy or original reading job.

  A paper feed unit 3 a that stores paper used for printing is provided below the multi-function device 100. A plurality of paper feeding units 3a can be provided by stacking in the vertical direction. FIG. 1 shows a mode in which the sheet feeding units 3a are stacked in three stages. Each paper feed unit 3a feeds paper one by one at the time of printing. A portion of each paper feed unit 3 a that accommodates paper can be removed as a cassette 31. Each paper feed unit 3a is provided with a paper feed roller 32 that is in contact with the uppermost paper and feeds the paper by feeding it.

  The transport unit 3b includes a guide plate for guiding the paper, a pair of transport rollers 33a and 33b that transports the paper by rotating, and a pair of registration rollers 34 that feeds the paper in accordance with the transfer timing of the formed toner image.

  The image forming unit 4a includes a photosensitive drum 4141, a charging device 42 for charging the photosensitive drum 41, an exposure device 43, a developing device 44 for developing an electrostatic latent image with toner, and a toner image formed on the photosensitive drum 41. It includes a transfer roller 45 that transfers to a sheet, a cleaning device 46 that scrapes off the surface of the photoreceptor drum 41, and the like. The exposure device 43 includes a semiconductor laser device 43a (see FIG. 5). The exposure device 43 outputs laser light while turning it on and off based on the image data, and scans and exposes each photosensitive drum 41. The registration roller pair 3444 causes the paper to enter the nip between the photosensitive drum 41 and the transfer roller 45 so that the toner image is transferred to an appropriate position in the paper at a timing. As a result, the toner image on the photosensitive drum 41 is transferred to the paper.

  The fixing unit 4b fixes the toner image transferred to the paper. The fixing unit 4b includes a heating roller 47 and a pressure roller 48 that incorporate a heating element. The pressure roller 48 is in pressure contact with the heating roller 47 to form a fixing nip. When the paper on which the toner image is transferred passes through the fixing nip, the toner is melted and heated, and the toner image is fixed on the paper. The sheet after toner fixing is discharged to the discharge tray 35.

(Hardware configuration of MFP 100)
Next, a hardware configuration of the multifunction peripheral 100 according to the embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating a hardware configuration of the multi-function device 100.

  The multifunction device 100 is provided with a main control unit 5. The main control unit 5 is connected to the operation panel 3, the document reading unit 1, the print engine unit 2, the storage unit 7, the communication unit 60 (corresponding to a data input unit), and the like, and controls the multifunction peripheral 100. The CPU 51 of the main control unit 5 performs processing such as computation for control. The image processing unit 6 responds to the setting made on the operation panel 3 or the setting data received by the communication unit 60 to the image data obtained by reading the document or the image data received by the communication unit 60. Image processing is performed to generate image data necessary for job execution.

  The storage unit 7 stores image data and the like in addition to programs and data for controlling the multifunction peripheral 100. The storage unit 7 includes volatile and nonvolatile storage devices such as a ROM 71, a RAM 72, an HDD 8 (corresponding to a hard disk drive and a magnetic storage device), and an SSD 9 (corresponding to a solid state drive and a semiconductor storage device). Based on the program and data stored in the storage unit 7, the CPU 51 controls the multifunction peripheral 100 by executing arithmetic processing and transmitting and receiving control signals.

  The communication unit 60 communicates with the computer 200 via a network, a communication line, or a cable based on an instruction from the main control unit 5. The communication unit 60 can transmit image data to the computer 200. Further, based on the image data received from the computer 200, the main control unit 5 causes the print engine unit 2 to perform printing based on the received image data.

  The main control unit 5 is connected to the document conveying unit 1b and the image reading unit 1a, and issues an operation instruction to read the document. The main control unit 5 is connected to an engine control unit 20 that controls the print engine unit 2. The engine control unit 20 includes an engine CPU 20 a that controls a part included in the print engine unit 2, and an engine storage unit 20 b that stores data and programs for controlling the print engine unit 2. The engine control unit 20 controls the operations of the paper feeding unit 3a, the conveyance unit 3b, the image forming unit 4a, and the fixing unit 4b based on an instruction from the main control unit 5, and causes the print engine unit 2 to perform printing.

  The main control unit 5 also recognizes the input made on the operation panel 3 and the content of the data received by the communication unit 60, and controls the multifunction peripheral 100 so that the job is performed according to the user settings and the received content. To do. For example, if the density change is set for the executed copy job on the operation panel 3, the main control unit 5 causes the document reading unit 1 to read the document, and the image processing unit 6 converts the density according to the setting. Processing is performed, and the print engine unit 2 performs printing.

(Data input part)
Next, a data input unit for inputting data used for printing will be described with reference to FIG. FIG. 3 is a diagram illustrating the data input unit.

  The multifunction device 100 is provided with a document reading unit 1 as a data input unit for inputting data (image data) used for printing to the multifunction device 100. As described above, the document reading unit 1 includes the document transport unit 1b and the image reading unit 1a.

  The document transport unit 1b is provided with a document transport control unit 10b. The document conveyance control unit 10b includes a CPU, a microcomputer, and a memory, and controls the operation of the document conveyance unit 1b based on an instruction from the main control unit 5. The document transport unit 1b is provided with a document detection sensor 15 for detecting whether or not a document is placed on the document tray 12. The output of the document detection sensor 15 is input to the document conveyance control unit 10b. The document conveyance control unit 10 b recognizes the presence or absence of a document placed on the document tray 12 based on the output of the document detection sensor 15.

  The document transport unit 1b is provided with a document transport motor that rotates a rotating body (such as the document feed roller 12a and the document transport roller 12b, see FIG. 1) that transports the document. When the start key 30 on the operation panel 3 is pressed to start reading a document, if a document is placed on the document tray 12, the document transport unit 1b rotates the document transport motor. Thereby, the originals are sent out from the original tray 12 one by one.

  The image reading unit 1a is provided with a reading control unit 10a that controls the operation of the image reading unit 1a and controls image data generation of a document. The reading control unit 10 a includes a CPU, a microcomputer, and a memory, and controls the operation of the image reading unit 1 a based on an instruction from the main control unit 5.

  The reading control unit 10a is communicably connected to the main control unit 5 and the document conveyance control unit 10b. The reading control unit 10a receives a document reading instruction (signal) from the main control unit 5 and controls the operation of each part in the image reading unit 1a. The reading control unit 10a includes a CPU, a microcomputer, and a memory. Then, when a document reading instruction is received from the main control unit 5 triggered by the start key 30 of the operation panel 3 being pressed, the reading control unit 10a is obtained by operation control of the image reading unit 1a or reading. The transmission control of the image data to the storage unit 7 (main control unit 5) is performed.

  A winding motor 17 is connected to the reading control unit 10a. Accordingly, the reading control unit 10a controls the rotation of the winding motor 17, rotates the winding drum (not shown), and moves the lamp 13 and the mirror. In reading a document when a document is placed on the document tray 12, the reading control unit 10a moves the lamp 13 and each moving frame of the mirror below the conveyance reading contact glass 11a. In reading a document when no document is placed on the document tray 12, the reading control unit 10a rotates the winding drum so that the lamp 13 and the mirror are directed from one end to the other end of the placement reading contact glass 11b. The document is moved at a constant speed, and the document on the placement reading contact glass 11b is read.

  The reading control unit 10 a is connected to the lamp 13 and controls the lamp 13 to be turned on and off. When it is necessary to turn on the lamp 13 such as when reading a document, the reading control unit 10 a turns on the lamp 13. On the other hand, the reading control unit 10a turns off the lamp 13 when it is not necessary to turn on the light, for example, when the reading of the document is completed.

  Further, the reading control unit 10a controls driving (operation) of the image sensor 14. When reading a document, the reading control unit 10 a operates the image sensor 14. For example, the image sensor 14 outputs analog electrical signals of three colors R, G, and B for each pixel. Thereby, electric charges are output from each pixel of the image sensor 14 as a voltage or a current according to the amount of received light. The output of the image sensor 14 is input to the read data processing unit 18.

  The read data processing unit 18 generates image data based on the output of the image sensor 14 and performs image processing on the generated image data. The read data processing unit 18 includes an A / D conversion unit 18a that converts an analog output from each pixel of the image sensor 14 into a digital value. The A / D conversion unit 18a performs quantization based on the analog output of each pixel of the image sensor 14, and quantizes to about 8 to 10 bits (24 to 30 bits in total) for each of R, G, and B for each pixel. To do. The read data processing unit 18 includes a correction unit 18b that corrects distortion in image data caused by each part of the image reading unit 1a, such as the characteristics of the lens, the lamp 13, and the image sensor 14. The correction unit 18b performs correction processing such as gamma correction and shading correction on the generated image data.

  The image data processed by the read data processing unit 18 is stored in the image memory 19. The image memory 19 sequentially transmits image data to the image processing unit 6 in units of a certain number of lines in the main scanning direction (page unit or band unit). The image processing unit 6 may receive the image data after storing the image data in the RAM 72 of the storage unit 7.

  Further, the multifunction device 100 is provided with a communication unit 60 as a data input unit for inputting data such as image data used for printing to the multifunction device 100.

  The communication unit 60 includes a communication control unit 60a as a controller that controls communication with the outside. Further, the communication unit 60 includes a communication memory 60b as a buffer for storing data to be transmitted and received data.

  The communication unit 60 receives print data for executing a print job (a job for printing using the multifunction peripheral 100 as a printer) from the computer 200. Driver software 201 for performing printing using the multifunction device 100 is installed in the computer 200. Then, the driver software 201 causes the computer 200 to generate print data including image data indicating the print contents and setting data indicating the setting contents of the print job set using the driver software 201. Then, the computer 200 transmits the generated printing data to the computer 200. The communication unit 60 receives print data transmitted from the computer 200.

  Then, the communication unit 60 transmits the received print data and image data to the image processing unit 6. Note that the image processing unit 6 may receive the image data after temporarily storing the image data in the RAM 72 of the storage unit 7.

(Temporarily save image data)
Next, temporary storage of image data will be described with reference to FIG. FIG. 4 is a diagram for explaining temporary storage of image data.

  As shown in FIG. 4, the image data generated by the document reading unit 1 and the image data received by the communication unit 60 are sent to the image processing unit 6.

  Here, in the present embodiment, in the case of a copy job or a print job, the exposure device 43 scans and exposes the photosensitive drum 41 based on the image data. Specifically, while rotating the photosensitive drum 41, the exposure device 43 turns on / off the laser based on the image data while shifting the irradiation position of the laser light in units of one pixel based on the image data. Then, when scanning and exposure are performed from the beginning to the end of one line, the exposure device 43 starts scanning and exposure to the next one line. As described above, the exposure device 43 repeats scanning and exposure in units of one line in the sub-scanning direction (the rotation direction of the photosensitive drum 41). As a result, an electrostatic latent image corresponding to the content to be printed is formed on the peripheral surface of the photosensitive drum 41. As described above, the image data is used for scanning and exposure by the exposure device 43.

  Here, the image data stored in the image processing unit 6 and the exposure device 43 is limited. Further, scanning and exposure are performed while rotating the photosensitive drum 41. Therefore, the image data after image processing needs to be transmitted to the exposure device 43 (print engine unit 2) in accordance with the exposure and exposure in the exposure device 43. However, the image data after the image processing is not immediately used for the exposure by the exposure device 43 when the image processing is performed on the image data input from the data input unit. Therefore, in the MFP 100 of the present embodiment, the main control unit 5 causes the HDD 8 or the SSD 9 to store (temporarily save) the image data after image processing used for printing.

  At the time of a copy job (when printing is performed based on image data read by the original reading unit 1) or at the time of a print job, the image processing unit 6 performs image processing according to the settings made on the operation panel 3 or printing. Image processing according to setting data included in the data or predetermined image processing is performed on the image data input to the multifunction peripheral 100. For example, the image processing unit 6 performs density conversion processing, data format conversion processing, and the like. The image processing unit 6 performs compression processing on the image data after the image processing. Image data compressed by the image processing unit 6 (hereinafter referred to as “compressed image data”) is temporarily stored in the HDD 8 or the SSD 9. Details of the storage in the HDD 8 or SSD 9 will be described later.

  The HDD 8 is a storage device that can store data in a nonvolatile manner. The HDD 8 includes a rotating magnetic disk 82, a magnetic head 83 for reading / writing data from / to the magnetic disk 82, a head moving unit 84 for moving the position of the head, and the like. The HDD controller 81 controls reading / writing with the magnetic head 83 and movement of the magnetic head 83 by the head moving unit 84. The storage capacity of the HDD 8 is at least several tens of gigabytes, and the multi-function device 100 according to the present embodiment has a capacity of several hundred gigabytes to several terabytes.

  The SSD 9 is also a storage device that can store data in a nonvolatile manner. The SSD 9 includes a semiconductor element memory 92 such as a flash ROM, and an SSD controller 91 that controls writing to and reading from the semiconductor element memory 92. The storage capacity of the HDD 8 is at least several gigabytes, and the multi-function device 100 according to the present embodiment is loaded with tens to hundreds of gigabytes.

  Note that the size of the compressed image data is, for example, about 1 to 2 megabytes. On the other hand, the HDD 8 and the SSD 9 have a transfer rate (speed for writing and reading) of at least about 8 to 10 megabytes / second.

(Reading compressed image data)
Next, reading of the temporarily stored compressed image data will be described with reference to FIG. FIG. 5 is a diagram for explaining reading of the temporarily stored compressed image data.

  The temporarily stored compressed image data is read from the HDD 8 or SSD 9 at a timing required for scanning and exposure by the exposure device 43. In other words, the temporarily stored compressed image data is prepared for scanning and exposure by the exposure device 43, and is sent to the print engine unit 2 (exposure device 43) before the scanning and exposure are started. Or read from SSD9.

  The compressed image data is once sent to the image processing unit 6. Then, the image processing unit 6 performs decompression processing on the compressed image data. The image processing unit 6 generates exposure image data to be supplied to the exposure device 43. The exposure image data is data indicating whether or not the semiconductor laser device 43a is turned on for each pixel. Then, the image processing unit 6 outputs (transmits) the exposure image data to the print engine unit 2 (exposure device 43) in time for scanning and exposure.

  Note that reading of image data from the HDD 8 or the SSD 9 is performed in a predetermined unit such as a page unit, a band unit, or a line unit.

(Preliminary operation for impact generation and temporary storage destination for impact operation)
Next, with reference to FIG. 1, FIG. 4, and FIG. 6, the impact generation preliminary operation and the change of the temporary storage destination of image data accompanying the impact operation will be described. FIG. 6 is a timing chart for explaining the impact generation preliminary operation and the change of the temporary storage destination of the image data accompanying the impact operation.

  An impact may be applied to the image forming apparatus and vibration may occur. For example, in the multifunction peripheral 100 of the present embodiment, the side covers 2a and 2b on the left side can be opened and closed for jam processing (processing for removing jammed paper) (see FIG. 1). When the side covers 2a and 2b are attached, an impact is applied to the multifunction device 100. The closer the side covers 2a and 2b are closed, the greater the impact applied to the multifunction device 100 and the greater the vibration.

  Open / close detection sensors S1 and S2 (for example, optical sensors and interlock switches) are provided for the side covers 2a and 2b, respectively. The engine control unit 20 and the main control unit 5 recognize the open / closed state of the side covers 2a and 2b based on the outputs of the open / close detection sensors S1 and S2.

  In addition, a toner container (not shown) that supplies toner to the developing device 44 is attached to the multifunction device 100. The toner cover (not shown) of the multifunction device 100 can be opened and closed so that the empty toner container can be replaced. The toner cover is provided on the front surface of the multifunction peripheral 100. When the toner cover is attached, an impact is applied to the multifunction device 100. The closer the toner cover is closed, the greater the impact applied to the multifunction device 100 and the greater the vibration. A toner cover sensor (not shown) is also provided for the toner cover. The engine control unit 20 and the main control unit 5 recognize the open / close state of the toner cover based on the output of the toner cover sensor.

  The cassette 31 of the paper feed unit 3a is used for paper supply, paper size change, jam processing, and the like. It can be attached or removed. When the removed (drawn) cassette 31 is closed, an impact is applied to the multifunction device 100. The closer the cassette 31 is closed, the greater the impact applied to the multifunction device 100 and the greater the vibration.

  Each paper feed unit 3a (cassette 31) has a cassette sensor S0 (see FIGS. 1 and 4) for detecting whether the cassette 31 has been removed or attached. In FIG. 4, only one is shown for convenience. .Corresponding to the detection unit). The engine control unit 20 and the main control unit 5 recognize whether the cassette 31 has been removed or attached based on the output of each cassette sensor S0.

  On the other hand, the multifunction peripheral 100 of this embodiment includes an HDD 8. A minute gap is provided between the magnetic head 83 of the HDD 8 and the magnetic disk 82. However, the magnetic head 83 may vibrate greatly due to impact and vibration. When the magnetic head 83 vibrates, the magnetic head 83 may collide with the magnetic disk 82, and the data stored in the collided portion may be damaged, or the surface of the magnetic disk 82 may be damaged. As described above, the hard disk drive is generally vulnerable to shock and vibration. On the other hand, since the SSD 9 does not have a mechanism like the HDD 8, it is more resistant to shock and vibration than the HDD 8, and can read and write data accurately even if there is some impact and vibration, causing damage like the HDD 8. Absent.

  Therefore, in the MFP 100 according to the present embodiment, when it is detected that a preliminary impact generation operation is performed before the impact operation, which is an operation that causes an impact during reading and writing on the HDD 8, the main control unit 5 Then, the temporary storage destination (write destination) of the compressed image data is switched from the HDD 8 to the SSD 9. Thus, the compressed image data can be temporarily stored accurately while protecting the HDD 8.

  Here, even if the cassette 31 that has not been fed is pulled out, there is no problem in feeding and printing from the cassette 31 (paper feed unit 3a) that is currently feeding paper. Therefore, the main control unit 5 does not cause the print engine unit 2 to stop printing when the cassette 31 that has not been fed is pulled out during printing. For this reason, it is necessary to read and write compressed image data even when a cassette 31 that has not been fed is pulled out. Therefore, in the multifunction peripheral 100 of the present embodiment, an operation of removing (drawing) the paper feeding unit 3a (cassette 31) that is not feeding paper among the plurality of paper feeding units 3a is handled as a shock generation preliminary operation. The main control unit 5 and the engine control unit 20 can recognize that the cassette 31 that has not been fed has been removed based on the output of the cassette sensor S0 corresponding to the cassette 31 being fed.

  On the other hand, when the cassette 31 being fed is removed (when it is pulled out), the main control unit 5 causes the engine control unit 20 to stop printing because the sheet cannot be fed. Therefore, it is not necessary to read out the compressed image data when the cassette 31 being fed is removed. Therefore, in the multifunction peripheral 100 of this embodiment, the removal of the cassette 31 that is feeding paper is not treated as an impact generation preliminary operation. Further, the operation of attaching the cassette 31 that has been fed is not treated as an impact operation. Note that the main control and engine control unit 20 can recognize that the cassette 31 that is being fed is removed during printing based on the output of the cassette sensor S0 corresponding to the cassette 31 that is being fed.

  Further, when the side covers 2a and 2b and the toner cover are closed, an impact is generated. However, the side covers 2a and 2b and the toner cover are opened and closed when the printing operation is stopped due to the occurrence of a jam or for maintenance. When the main control unit 5 recognizes that the side covers 2a and 2b and the toner cover have been opened, the main control unit 5 performs a printing operation (paper conveyance, scanning of the photosensitive drum 41, exposure and toner) until it is closed. Image forming operation) is stopped. Since printing is stopped, reading of compressed image data is not necessary. Therefore, in the MFP 100 of the present embodiment, the operation of opening the side covers 2a and 2b and the toner cover is not treated as a shock generation preliminary operation. Also, the operation of closing the side covers 2a and 2b and the toner cover is not treated as an impact operation. The main control unit 5 and the engine control unit 20 can recognize the opening / closing of various covers based on the outputs of the opening / closing detection sensor and the toner cover sensor.

  Next, the temporary storage destination of the compressed image data will be specifically described with reference to FIG. The horizontal axis in FIG. 6 shows the flow of time.

  When temporarily storing the compressed image data, the main control unit 5 stores (temporarily saves) the compressed image data in the HDD 8 before the engine control unit 20 detects the impact occurrence preliminary operation. Until the time).

  When the engine control unit 20 detects an impact generation preliminary operation (when the cassette 31 that has not been fed is pulled out, at time T1 in FIG. 6), the engine control unit 20 generates an impact on the main control unit 5. Notify that a preliminary operation has been made. As a result, the main control unit 5 recognizes that the shock generation preliminary operation has been performed. Subsequently, the main control unit 5 stores (temporarily saves) the compressed image data in the SSD 9.

  Then, the main control unit 5 performs the first time period U1 (from the time T1 to the time T3 in FIG. 6) including the time from the detection of the shock generation preliminary operation to the time when the shock operation is detected (time T2 in FIG. 6). ), The compressed image data is stored in the SSD 9 (temporarily saved). The engine control unit 20 detects that an impact operation has been performed by detecting that the opened cassette 31 is mounted based on the cassette sensor S0. Then, the engine control unit 20 notifies the main control unit 5 that the impact operation has been performed, so that the main control unit 5 recognizes (detects) that the impact operation has been performed.

  Here, the first time zone U1 may be a time point when the impact operation is performed from the time point when the impact generation preliminary operation is performed. The first time period U1 may be a time obtained by adding a predetermined convergence time to the time from the time when the impact generation preliminary operation is performed to the time when the impact operation is performed. The convergence time is a time in anticipation that the vibration caused by the impact operation is within a range that does not hinder the reading and writing of the HDD 8 (for example, 1 to several seconds).

  Then, with the end of the first time zone U1, the main control unit 5 stores the compressed image data in the HDD 8 (temporarily saves it after time T3 in FIG. 6). Although the number of times of writing is limited in the semiconductor element memory 91 of the SSD 9, only the first time zone U1 is written, so the life of the SSD 9 can be greatly extended.

  On the other hand, in the second time zone U2 that is not the first time zone U1, the compressed image data is stored in the HDD 8 (temporarily stored, up to the time T1 in FIG. 6 and after the time T3).

(Procedure for generating an impact and changing the temporary storage location associated with the impact operation)
Next, with reference to FIG. 7, the flow of preliminary operation for generating an impact and changing the temporary storage destination accompanying the impact operation will be described. FIG. 7 is a flowchart showing a flow of changing the temporary storage destination of the image data accompanying the impact generation preliminary operation and the impact operation.

  The start of FIG. 7 starts the input of image data to the multi-function device 100, such as when the document reading unit 1 starts reading the document or when the communication unit 60 receives print data from the computer 200. It is the time when

  Then, the main control unit 5 checks whether or not the current time is the first time zone U1 (step # 11). Specifically, the main control unit 5 confirms whether or not the current time is the first time zone U1 based on the notification of the shock generation preliminary operation and the detection of the shock operation from the engine control unit 20.

  If it is the first time zone U1 (Yes in step # 11), the main control unit 5 causes the compressed image data output from the image processing unit 6 to be written in the SSD 9 and temporarily stored in the SSD 9 (step # 12). On the other hand, if it is the second time zone U2 (No in step # 11), the main control unit 5 causes the compressed image data output from the image processing unit 6 to be written in the HDD 8 and temporarily stored in the HDD 8 (step # 13). ).

  If the temporary storage of the compressed image data for all pages in the job is completed after step # 12 and step # 13 (step # 14), this flow ends (end of step # 14). On the other hand, if the temporary storage of the compressed image data for all pages in the job has not been completed (No in step # 14), the flow returns to step # 11.

(Reading according to impact generation preliminary operation and impact operation)
Next, referring to FIG. 1, FIG. 4, and FIG. 8, the impact generation preliminary operation and reading of the image data according to the impact operation will be described. FIG. 8 is a timing chart for explaining the impact generation preliminary operation and the reading of the image data accompanying the impact operation.

  The image data temporarily stored in the HDD 8 or the SSD 9 may be read for scanning and exposure by the exposure device 43 even after the impact generation preliminary operation is performed until the impact operation is performed.

  As described with reference to FIG. 6, in the MFP 100 according to the present embodiment, when the second time zone U2 is reached due to the end of the first time zone U1 (at time T3 in FIGS. 6 and 8), the main control is performed. The unit 5 writes (stores) the compressed image data in the HDD 8. When an impact occurrence preliminary operation is detected (at time T1 in FIGS. 6 and 8) and the first time zone U1 is reached, the main control unit 5 causes the SSD 9 to write (store) the compressed image data.

  Since it is necessary to read from the writing location, in principle, the compressed image data written to the HDD 8 is read from the HDD 8. On the other hand, the compressed image data written to the SSD 9 is read from the SSD 9.

  However, if the principle is followed, the compressed image data temporarily stored in the HDD 8 before the first time zone U1 is read from the HDD 8 even after the impact occurrence preliminary operation is detected (even during the first time zone U1). There is a need. However, if the time from the impact generation preliminary operation to the impact operation is short, the impact operation may be performed while the compressed image data temporarily stored in the HDD 8 is being read. Then, the reading of the compressed image data from the HDD 8 may be delayed due to the impact or vibration caused by the impact operation. As a result, supply of image data (exposure image data) is not in time for scanning and exposure by the exposure device 43, and the engine control unit 20 stops all the operations of the print engine unit 2 to scan the photosensitive drum 41. Printing operations such as exposure and paper conveyance may be stopped.

  Therefore, when the shock generation preliminary operation is detected, the main control unit 5 is the compressed image data stored in the HDD 8 before the shock generation preliminary operation (compressed image data not stored in the SSD 9), and the shock generation occurs. The compressed image data for one or a plurality of pages is copied (stored) in the SSD 9 retroactively from the page written in the HDD 8 during the preliminary operation. In this copy, the main control unit 5 sets the SSD 9 in advance as the shortest time from the detection of the shock generation preliminary operation to the detection of the shock operation, starting from the page written in the HDD 8 during the shock generation preliminary operation. The image data for the number of pages within the range that can be copied within the reference time is copied. Note that compressed image data is read from the HDD 8 as necessary. In other words, the main control unit 5 causes the compressed image data to be copied to the SSD 9 between reading of the compressed image data from the HDD 8. Then, in the first time zone U1, the main control unit 5 causes the SSD 9 to read out the compressed image data copied in accordance with the scanning and exposure by the exposure device 43.

  For example, when the removal of the cassette 31 is detected at the time when reading of the third sheet is completed while reading five originals, the main control unit 5 causes the SSD 8 to the SSD 9 of the first to third sheets of compressed image data. In parallel with the copying, the SDD 9 stores compressed image data based on the reading of the fourth and fifth sheets. However, if the loading of the cassette is detected after the completion of the reading of the fourth sheet and before the generation of the fifth compressed image data, the fifth compressed image data is stored in the HDD 8. Subsequently, when reading, the main control unit 5 reads five pieces of compressed image data from the HDD 8 or the SSD 9.

  Here, the “reference time” is a predetermined time as the shortest time from the detection of the shock occurrence preliminary operation to the detection of the shock operation (the shortest time from when the cassette 31 is pulled out to when it returns), and is appropriately determined ( For example, about 1-2 seconds). For example, when compressed image data for 8 to 10 pages can be copied from the HDD 8 to the SSD 9 within the reference time, the number of pages of 8 to 10 pages or less is copied from the HDD 8 to the SSD 9 (from the shock generation preliminary operation to the reference time). The maximum number of pages that can be transferred before elapses). The main control unit 5 does not copy the compressed image data of the printed page (it is not necessary to copy).

  For example, when the MFP 100 according to the present embodiment can print 30 sheets per minute (printing 1 sheet every 2 seconds), if the reference time is about 2 seconds, the page written in the HDD 8 during the shock occurrence preliminary operation is displayed. Further, if the compressed image data is copied from the HDD 8 to the SSD 9 and read from the SSD 9 by going back about two pages, an impact operation is not performed during the reading of the compressed image data from the HDD 8.

  In this way, the main control unit 5 prevents the SSD 8 of the compressed image data from the HDD 8 within the reference time assumed as the shortest time from the impact preparatory operation to the impact operation so that the impact operation is not performed during reading from the HDD 8. This completes the copy process.

  When the copy from the HDD 8 to the SSD 9 is completed (time T4 in FIG. 8), the main control unit 5 retracts the magnetic head 83 of the HDD 8. The head moving unit 84 retracts the magnetic head 83 to a position where it does not contact the magnetic disk 82 even if the magnetic head 83 vibrates.

  8 indicates a time point when reading of all the compressed image data written in the SSD 9 during the first time period U1 is completed. The main control unit 5 continues writing compressed image data to the SSD 9 until the end of the first time period U1 (at time T3 in FIGS. 6 and 8). Further, if necessary for printing, the main control unit 5 causes the SSD 9 to read the compressed image data that has been written in parallel with the writing of the compressed image data (the main control unit 5 For the HDD 8 as well, the compressed image data is written and the compressed image data is read out when necessary (the HDD 8 performs parallel processing). Therefore, basically, reading of all compressed image data from the SSD 9 is after the end of the first time period U1.

  However, if the time until the cassette 31 is pulled out and returned is short, copying of the compressed image data from the HDD 8 to the SSD 9 within the reference time causes both the HDD 8 and the SSD 9 to store the compressed image data of the page being read. May be memorized. In this case, the main control unit 5 reads the compressed image data copied to the SSD 9 instead of the HDD 8 in the first time zone U1, and in the second time zone U2, the main control unit 5 reads the compressed image data of the copied portion into the HDD 8. Is read out. Even in the second time zone U2, the compressed image data copied from the HDD 8 may be read from the SSD 9.

(Pre-operation for impact generation and flow of reading according to the impact operation)
Next, the flow of reading according to the impact generation preliminary operation and the impact operation will be described with reference to FIG. FIG. 9 is a flowchart showing a flow of reading according to the impact generation preliminary operation and the impact operation.

  The start of FIG. 9 is a time when reading of compressed image data from the HDD 8 or SSD 9 is started by the start of printing in the print engine unit 2.

  First, the main control unit 5 causes the compressed image data to be read out from the HDD 8 and the SSD 9 in which the compressed image data to be read is temporarily stored in accordance with the scanning and exposure start timing of the exposure device 43 ( Step # 21). If the cassette 31 has been completely closed (attached) from the start of temporary storage, the compressed image data is read from the HDD 8. Based on the read image data, the exposure device 43 scans and exposes the photosensitive drum 41 for each line.

  Then, the main control unit 5 checks whether or not reading of all compressed image data has been completed for the job being printed (step # 22). In other words, the main control unit 5 checks whether or not the compressed image data for scanning and exposing the last line of the last page of the print job (copy job or print job) has been read.

  If reading of all compressed image data is completed for the job being printed (Yes in step # 22), this flow ends (end). On the other hand, when reading of all the compressed image data has not been completed (No in Step # 22), the main control unit 5 checks whether or not an impact occurrence preliminary operation has been detected (Step # 23). If no shock generation preliminary operation is detected (No in step # 23), the flow returns to step # 21. On the other hand, if a shock generation preliminary operation is detected (Yes in step # 23), the main control unit 5 stores compressed image data for one or a plurality of pages from the HDD 8 to the SSD 9 from the shock generation preliminary operation to the reference time. Are copied (step # 24).

  Upon completion of copying, the main control unit 5 retracts the magnetic head 83 of the HDD 8 (step # 25). Then, the flow returns to step # 21. When returning to the second time zone U2 (the cassette 31 is already closed) and writing the compressed image data to the HDD 8, the main controller 5 reads / writes the magnetic head 83 from / to the magnetic disk 82. The magnetic head 83 is moved to the head moving unit 84 so as to be in a position to perform.

  Since the semiconductor storage device (SSD 9) does not include a rotating or moving part (magnetic disk 82 or a mechanism for moving the head) like the magnetic storage device (HDD 8), it is structurally more than the magnetic storage device (HDD 8). Resistant to shock and vibration. Therefore, the semiconductor storage device (SSD 9) can read and write more accurately than the magnetic storage device (HDD 8) even when there is an impact or vibration. In view of this, the image forming apparatus (multifunction peripheral 100) according to the present embodiment has a data input unit (document reading unit 1, communication unit 60) for inputting data used for printing to the image forming apparatus, and an image forming apparatus. A detection unit (cassette sensor S0) for detecting that an impact operation, which is an operation that generates an impact, and an impact generation preliminary operation, which is a preliminary operation of the impact operation, are performed, and a semiconductor element memory 92. A semiconductor memory device (SSD9) that stores image data based on data input from the data input unit in a nonvolatile manner, a magnetic disk 82, and a magnetic head 83 for reading and writing data to and from the magnetic disk 82. , A magnetic storage device (HDD 8) for storing data in a nonvolatile manner, and image data (compressed) read from the magnetic storage device or the semiconductor storage device Includes a print engine unit 2 for performing printing based on the image data), the reading of the semiconductor memory device and a magnetic storage device, a control unit for controlling the writing of the (main controller 5). Then, the control unit causes the semiconductor storage device to store the image data to be transmitted to the print engine unit 2 in the first time period U1 including the time from when the impact occurrence preliminary operation is detected to when the impact operation is detected. The image data stored during the first time period U1 is read (in time for printing in the print engine unit 2). In addition, the control unit causes the magnetic storage device to store the image data to be transmitted to the print engine unit 2 in the second time zone U2 that is a time zone excluding the first time zone U1, and then, in the second time zone U2. The image data stored in the meantime is read (in time for printing in the print engine unit 2).

  As a result, when an impact generation preliminary operation is performed and the impact operation is eventually performed and it can be predicted that an impact or vibration will occur, a semiconductor memory device (SSD9) that is resistant to impact and vibration is used instead of the magnetic storage device (HDD 8) ) Is used. Even when an impact or vibration occurs, image data can be read and written accurately without delay. Therefore, the interruption of printing due to shock or vibration that occurs only in the case of the magnetic storage device does not occur. In addition, the number of times of rewriting the nonvolatile semiconductor element memory 92 may be limited (if the update is repeated, the life of the semiconductor element memory 92 itself may be exhausted). However, since the semiconductor memory device is used only in the first time zone U1, the life of the semiconductor memory device can be greatly extended. Further, in the case where only the semiconductor memory device is provided as the part for storing the image data, the life of the semiconductor memory device may be exhausted before the life of the other part of the image forming apparatus (multifunction device 100) is exhausted. However, since the magnetic storage device is used in combination, the life of the image forming apparatus can be greatly extended as a whole. In addition, since the magnetic memory device is mainly used and the semiconductor memory device is used only in the first time zone U1, the capacity of the semiconductor memory device does not need to be increased so much, and generally a nonvolatile semiconductor memory having a high unit price per bit. The equipment can be inexpensive. Therefore, an increase in manufacturing cost of the image forming apparatus can be suppressed.

  In the “first time zone U1”, the time from the detection of the impact occurrence preliminary operation to the detection of the impact operation, and the level of the impact or vibration caused by the impact operation from the time when the impact operation is detected are magnetically stored. It is possible to add the time to the point of time when it is predicted that the reading will be performed to the extent that there is no problem in reading and writing in the device (HDD 8) (the extent that the magnetic head 83 does not contact the magnetic disk 82). In other words, it is the time from the detection of the impact occurrence preliminary operation until the impact or vibration due to the impact operation is lowered to a certain level. The time until the impact or vibration generated by the impact operation is settled may be appropriately determined based on an experiment or the like.

  If the impact operation is performed within a short time after the impact generation preliminary operation, the image data may be read from the magnetic storage device (HDD 8) at the time of the impact operation. In other words, if the impact operation is performed within a short time after the impact generation preliminary operation, printing is performed using the image data written in the magnetic storage device (HDD 8) before the impact generation preliminary operation at the time of the impact operation. There may be. Therefore, when the impact generation preliminary operation is detected, the control unit (main control unit 5) stores the image data (compression) stored in the magnetic storage device (HDD 8) in the semiconductor storage device (SSD9) before the impact generation preliminary operation. Image data). In this copy, the control unit records in advance the semiconductor memory device in advance as the shortest time from the detection of the shock generation preliminary operation to the detection of the shock operation, starting from the page written in the magnetic storage device during the shock generation preliminary operation. Image data corresponding to the number of pages within a range that can be copied within a predetermined reference time is copied. Then, the control unit reads the image data copied by the semiconductor storage device instead of the magnetic storage device in the first time zone U1, and in the second time zone U2, the magnetic storage device reads the image data of the copied portion. It was decided to read.

  As a result, image data that has been written to the magnetic storage device (HDD 8) and that may be read during an impact operation can be read from the semiconductor storage device (SSD 9). Therefore, even if the impact operation is performed within a short time after the impact generation preliminary operation, printing is not interrupted by reading the image data from the semiconductor memory device. In addition, since the copy is completed within the reference time, the copy can be completed at the time when the impact operation is performed even in a short time from the impact generation preliminary operation to the impact operation. Further, since the copied image data is read from the magnetic storage device at the second time zone U2, the life of the SSD 9 can be extended.

  The image processing unit 6 includes an image processing unit 6 that performs image processing on data input from the data input unit (the document reading unit 1 and the communication unit 60) and compresses the image data after the image processing. 5) causes the magnetic storage device (HDD 8) and the semiconductor storage device (SSD 9) to read and write compressed image data. Since the compressed image data is read while being written to the magnetic storage device (HDD 8) or the semiconductor storage device (SSD 9), the time required for writing or reading the image data for one page can be shortened. Therefore, even when the number of printed sheets per unit time of the image forming apparatus (multifunction device 100) is large, image data can be written and read without delay.

  Further, the magnetic storage device (HDD 8) retracts the magnetic head 83 from the read / write position when reading / writing is no longer necessary (for example, when data copying is completed) in the first time period U1. Thereby, the magnetic head 83 can be separated from the magnetic disk 82 before the impact operation. Therefore, damage to the magnetic head 83 and the magnetic disk 82 due to impact and vibration can be prevented, and data stored in the magnetic disk 82 and the magnetic disk 82 can be protected.

  In the image forming apparatus (multifunction peripheral 100) according to the embodiment, the print engine unit 2 includes a paper feeding unit 3a that feeds paper, and the paper feeding unit 3a includes a cassette 31 that accommodates paper and is detachable. In addition, the detection unit (cassette sensor S0) detects that the cassette 31 has been pulled out as an impact generation preliminary operation, and detects that the cassette 31 has been mounted as an impact operation. Accordingly, it is possible to detect an operation for giving an impact during printing by a user and a preliminary operation for generating an impact without providing a complicated and expensive sensor such as an acceleration sensor.

  The magnetic storage device is a hard disk drive, and the semiconductor storage device is a solid state drive. As a result, a magnetic storage device (HDD 8) or a semiconductor storage device (SSD 9) having a sufficient speed and capacity for storing image data is used.

  Next, another embodiment will be described. In the above embodiment, the example in which the insertion / removal (withdrawal and return) of the cassette 31 is handled as the impact generation preliminary operation and the impact operation has been described. However, if the reading of a plurality of documents placed on the document tray 12 is continued even when the side covers 2a and 2b and the toner cover are opened, the main control unit 5 notifies the engine control unit 20 of the notification. The side cover 2a, 2b and the toner cover are attached by recognizing that the drawer 31 of the feeding cassette 31 and the side covers 2a and 2b and the toner cover are opened are recognized as a shock generation preliminary operation. This may be recognized as an impact operation.

  In the above embodiment, the SSD 9 is taken as an example of the semiconductor memory device. However, the semiconductor element memory 91 provided on the substrate such as the main control unit 5 or the semiconductor element memory 91 such as a portable memory is used instead of the SSD 9. But you can.

  The embodiment of the present invention has been described above, but the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used for an image reading apparatus and an image forming apparatus including the image reading apparatus.

100 MFP (image forming apparatus) 1 Document reading unit (data input unit)
2 Print engine section 3a Paper feed section 31 Cassette 5 Main control section (control section)
6 Image processing unit 60 Communication unit (data input unit)
8 HDD (Magnetic Storage Device) 82 Magnetic Disk 83 Magnetic Head 9 SSD (Semiconductor Storage Device)
92 Semiconductor element memory S0 Cassette sensor (detection unit)
U1 1st time zone U2 2nd time zone

Claims (5)

A data input unit for inputting data used for printing to the image forming apparatus;
A detection unit for detecting that an impact operation, which is an operation causing an impact on the image forming apparatus, has been performed, and an impact generation preliminary operation, which is a preliminary operation of the impact operation, is performed;
A semiconductor memory device including a semiconductor element memory and storing image data based on data input from the data input unit in a nonvolatile manner;
A magnetic storage device that includes a magnetic disk and a magnetic head for reading and writing data to and from the magnetic disk, and stores the image data in a nonvolatile manner;
A print engine unit that performs printing based on the image data read from the magnetic storage device or the semiconductor storage device;
A control unit for controlling reading and writing of the semiconductor storage device and the magnetic storage device,
The control unit causes the semiconductor storage device to store the image data to be transmitted to the print engine unit in a first time period including from when the shock generation preliminary operation is detected to when the shock operation is detected. Then, the image data is read out,
Further, in the second time zone that is a time zone excluding the first time zone, the image data is stored in the magnetic storage device, and then the image data is read out ,
When the shock generation preliminary operation is detected, the semiconductor storage device is caused to copy the image data stored in the magnetic storage device before the shock generation preliminary operation from the magnetic storage device,
In the copy, the shortest time from detection of the shock generation preliminary operation to detection of the shock operation is traced back to the semiconductor storage device in order from the page written in the magnetic storage device at the time of the shock generation preliminary operation. The image data for the number of pages within a range that can be copied within a predetermined reference time is copied,
In the first time zone, the image data copied by the semiconductor memory device instead of the magnetic memory device is read, and in the second time zone, the image data of the portion copied to the magnetic memory device is read. read allowed the image forming apparatus according to claim Rukoto. An image processing unit that performs image processing on the data input from the data input unit and compresses the image data after the image processing;
The image forming apparatus according to claim 1 , wherein the control unit causes the magnetic storage device and the semiconductor storage device to read and write the compressed image data. 3. The image forming apparatus according to claim 1, wherein the magnetic storage device retracts the magnetic head from the read / write position when reading / writing is no longer necessary in the first time period. 4. The print engine unit includes a paper feeding unit for feeding paper,
The paper feeding unit contains a paper cassette and includes a detachable cassette;
The detection unit detects that said cassette is drawn out as the impulse generator preliminary operation, any one of claims 1 to 3 wherein the cassette and detecting as the impact operation to be mounted The image forming apparatus described in the item. The magnetic storage device is a hard disk drive;
The semiconductor memory device, an image forming apparatus according to any one of claims 1 to 4, characterized in that a solid-state drive.

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