JP2012070028A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of allowing a user to select whether or not the performance deterioration of the image forming apparatus is permitted to continuously use an external memory by his/her intension, when the external memory with a low transfer speed is connected.SOLUTION: A multi function printer (MFP) 1 includes: an external memory controller 7 for removably connecting an external memory 71; a CPU 4 for determining whether or not a new external memory 71 is connected to the external memory controller 7 based on device specific information, calculating a data transfer speed of the external memory 71 when the external memory 71 is the newly connected one, comparing the data transfer speed of the external memory 71 with a data processing speed of the MFP 1, and determining whether the deterioration of data processing performance in the MFP 1 is expected or not based on the comparison result; and a display part 11 for notifying a user of an effect that the deterioration of the data processing performance in the MFP 1 is expected when the deterioration is expected, and also allowing the user to select whether or not the deterioration of the data processing performance in the MFP 1 is permitted to use the external memory 71.

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus to which an external storage device is detachably connected.

  As with other digital devices, MFPs (Multi Function Printers) with multiple image forming functions such as print and copy functions have various demands for cost reduction, high performance, and multi-functionality, and technological advances・ Evolution continues every day with the efforts of engineers. For products with relatively low production volume, such as MFPs, one of the ways to reduce costs is to penetrate the world, such as personal computers and digital cameras, and select parts that are common to devices already in use. Can be mentioned. These devices benefit from mass production and can be used at low cost.

  The same can be said for external storage devices used in MFPs. For example, HDDs (Hard Disk Drives) and SSDs (Solid State Drives) similar to personal computers as well as SD cards and compact flashes (such as digital cameras) All devices, such as registered trademarks, are subject to selection. On the other hand, if you use general-purpose devices that are generally used in this way, you can easily replace and connect devices because users already accustomed already have a lot of knowledge and information. The external storage device can be exchanged.

  Since these connected devices can be used if the physical I / F and the protocol used for transfer match, devices of various specifications may be connected. Particularly important specifications include data transfer performance to devices and storable capacity. It is also true that some external storage devices of the same model number do not have sufficient performance due to defective products or failures.

  Here, when the transfer performance of the external storage device is not at a sufficient level, this becomes a bottleneck, and there is a problem that the performance of the MFP is lowered. For example, in the MFP, when data in the external storage device is read and printed, if the data reading speed of the external storage device is 30 pages / minute and the data printing speed of the MFP is 40 pages / minute, the external storage device Since the data reading speed is slower than the data printing speed of the MFP, the data printing performance of the MFP is limited to the data reading speed (30 pages / minute) of the external storage device.

  To deal with such a problem, for example, Patent Document 1 discloses an MFP to which a technique called RAID (Redundant Arrays of Inexpensive Disks) that manages a plurality of hard disks as one hard disk is applied. According to this, when a plurality of hard disks are replaced in an MFP capable of connecting a plurality of hard disks, any one of the replaced hard disks is connected, and the transfer speed is measured for the connected hard disks. To do. The MFP prompts the user to connect another hard disk if the hard disk transfer speed is lower than the lower limit value, and satisfies the transfer performance by adding the hard disk.

JP 2006-121438 A

  In the technique described in Patent Document 1 above, when the transfer speed of the hard disk connected to the MFP is equal to or lower than the lower limit value, another hard disk is added and connected, and a plurality of hard disks are combined to satisfy the transfer speed. Like to do. In other words, when a hard disk with a slow transfer speed is connected, another hard disk must be added and connected, so that a hard disk with a slow transfer speed cannot be used alone.

  However, some users may want to use this hard disk as it is, allowing a decrease in the processing performance of the MFP due to the use of a hard disk with a slow transfer speed. Therefore, when a hard disk with a low transfer speed is connected, it is desirable to let the user select whether to use this hard disk. However, the technique described in Patent Document 1 cannot solve such a problem. .

  The present invention has been made in view of the above circumstances, and when an external storage device having a low transfer rate is connected, the external storage device can be used by allowing the user to reduce the performance of the image forming apparatus according to the intention of the user. It is an object of the present invention to provide an image forming apparatus that can select whether or not to continue.

  In order to solve the above-described problem, a first technical means of the present invention is an image forming apparatus provided with an external storage device interface for detachably connecting an external storage device, which is new to the external storage device interface. A connection determination unit that determines whether or not an external storage device is connected from device-specific information of the external storage device, and if it is determined that the external storage device is newly connected, A data transfer speed calculation unit that calculates a data transfer speed, and compares the calculated data transfer speed of the external storage device with the data processing speed of the image forming apparatus, and based on the comparison result, the image forming apparatus A performance determination unit that determines whether or not a decrease in data processing performance is expected, and when it is determined that a decrease in data processing performance of the image forming apparatus is expected, And a notification unit that allows the user to select whether or not to use the external storage device while allowing a decrease in data processing performance of the image forming apparatus. It is.

  In the second technical means, in the first technical means, when the performance determination unit determines that the data processing performance of the image forming apparatus is expected to be reduced, the notification unit performs data transfer to the external storage device. The data processing speed of the image forming apparatus limited by the speed is notified to the user.

  According to a third technical means, in the first or second technical means, the data processing speed of the image forming apparatus is the number of pages processed per unit time, and the data transfer speed calculation unit Measure the data transfer amount per unit time by the device, and calculate the number of pages transferred per unit time as the data transfer rate of the external storage device based on the measured data transfer amount per unit time It is characterized by.

  According to a fourth technical means, in the first or second technical means, the data transfer speed of the external storage device is a data writing speed when data is written to the external storage device, and the data of the image forming apparatus The processing speed is a data reading speed of a scanner unit included in the image forming apparatus, and the performance determination unit compares the data writing speed of the external storage device with the data reading speed of the image forming apparatus, and When the data writing speed of the storage device is slower than the data reading speed of the image forming apparatus, it is determined that a decrease in the data reading performance of the image forming apparatus is expected.

  According to a fifth technical means, in the first or second technical means, the data transfer speed of the external storage device is a data read speed when reading data from the external storage device, and the data processing of the image forming apparatus The speed is a data printing speed of a printing unit included in the image forming apparatus, and the performance determination unit compares a data reading speed of the external storage device with a data printing speed of the image forming device, and the external storage device When the data reading speed is slower than the data printing speed of the image forming apparatus, it is determined that the data printing performance of the image forming apparatus is expected to deteriorate.

  According to a sixth technical means, in any one of the first to fifth technical means, a capacity for determining whether or not a storage capacity of the external storage device satisfies a minimum capacity necessary for the operation of the image forming apparatus. A determination unit, and when the capacity determination unit determines that the storage capacity of the external storage device does not satisfy the minimum capacity, the notification unit notifies the user to that effect.

  According to a seventh technical means, in the sixth technical means, it is determined by the performance determining unit that a decrease in data processing performance of the image forming apparatus is not expected, and the capacity determining unit stores the data in the external storage device. When it is determined that the capacity satisfies the minimum capacity, the storage area used for data storage of the external storage device can be adjusted.

  According to an eighth technical means, in the sixth technical means, the user selects to use the external storage device while allowing a decrease in data processing performance of the image forming apparatus in response to the notification of the notification unit. In addition, when the capacity determination unit determines that the storage capacity of the external storage device satisfies the minimum capacity, the storage area used for data storage of the external storage device can be adjusted. It is.

  According to a ninth technical means, in the seventh or eighth technical means, adjustment of a storage area used for storing data in the external storage device is performed according to a user operation.

  According to a tenth technical means, in the seventh or eighth technical means, adjustment of a storage area used for storing data in the external storage device is performed according to a mode preset by a user. .

  According to the present invention, when an external storage device having a low transfer rate is connected, it is notified that the processing performance of the image forming apparatus is expected to deteriorate, and whether or not the user uses the external storage device. Therefore, depending on the user's intention, it is possible to select whether to continue to use the external storage device while allowing the performance of the image forming apparatus to decline, or to prepare a new external storage device according to the response of a service person, etc. It becomes.

1 is a block diagram illustrating a configuration example of an image forming apparatus according to an embodiment of the present invention. FIG. 6 is a diagram for explaining an example of scanner processing by an MFP. FIG. 6 is a diagram for explaining an example of a printing process by an MFP. FIG. 10 is a flowchart for explaining an operation example by the MFP according to the embodiment of the present invention. 6 is a diagram showing an example of a screen for notifying that a decrease in the data processing performance of the MFP is expected and for selecting whether to use the external storage device while permitting a decrease in the data processing performance of the MFP. FIG. FIG. 10 is a flowchart for explaining an operation example by the MFP according to another embodiment of the present invention. It is a figure for demonstrating the example of adjustment of the storage area utilized for the data preservation | save of an external storage device.

  Hereinafter, preferred embodiments according to an image forming apparatus of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a configuration example of an image forming apparatus according to an embodiment of the present invention. In the figure, 1 denotes the image forming apparatus. Hereinafter, the image forming apparatus 1 will be described as an example of an MFP (hereinafter referred to as MFP 1) that includes at least the scanner unit 21 and the printing unit 31. The MFP 1 performs image processing with a scanner I / F 2 that is an interface that communicates with the scanner unit 21, a print engine I / F 3 that is an interface that communicates with the printing unit 31, a CPU 4 that controls the MFP 1, and the like. An image processing unit 5, a compression unit 6 for compressing image data, an external storage device controller 7 corresponding to an external storage device interface for detachably connecting the external storage device 71, a RAM 8 as a volatile memory, A ROM 9 that is a non-volatile memory, a decompression unit 10 that decompresses compressed image data, and a display unit 11 that is an example of a notification unit that displays various messages and notifies the user.

  The CPU 4 controls the operation of the MFP 1 by reading and executing the control program (firmware) expanded in the RAM 8. The ROM 9 is a memory device in which a control program is stored. After the system is started, the control program in the ROM 9 is read by the CPU 4 and developed on the RAM 8. The RAM 8 is used as a work memory for developing a control program read from the ROM 9.

  The scanner I / F 2 receives image data that has been optically read by the scanner unit 21 and converted into digital data. The received image data is temporarily stored on the RAM 8. The print engine I / F 3 reads image data once stored in the RAM 8 and transmits it to the printing unit 31 for printing processing.

  The image processing unit 5 performs optimal image processing on the image data read by the scanner unit 21, image data stored in the external storage device 71, FAX image data, and the like according to various requests. The compression unit 6 mainly generates image data by compressing image data and reducing the data size. The decompressing unit 10 decompresses the compressed image data. The external storage device controller 7 is an interface for controlling the external storage device 71 and inputting / outputting data stored in the external storage device 71. Specifically, in accordance with an instruction from the CPU 4, processing for reading data from the RAM 8 and transferring it to the external storage device 71, processing for reading data from the external storage device 71 and transferring it to the RAM 8, and the like are executed. The external storage device 71 is a storage device for storing various data, and inputs and outputs data according to instructions from the external storage device controller 7.

  FIG. 2 is a diagram for explaining an example of scanner processing by the MFP 1. In this example, a case where a document is read by the scanner unit 21 and stored in the external storage device 71 via the external storage device controller 7 (not shown) will be described. First, a document is read as analog data by the scanner unit 21, and after AD (analog / digital) conversion, image data is temporarily written in the RAM 8 as digital data. Next, the image processing unit 5 reads the image data once stored in the RAM 8, performs various image processing, and then writes it back to the RAM 8. The image data for which image processing has been completed is compressed by the compression unit 6 and written again to the RAM 8, and finally, the compressed data in the RAM 8 is written to the external storage device 71, and a series of scanner processing is completed.

  FIG. 3 is a diagram for explaining an example of the printing process performed by the MFP 1. In this example, a case where image data is read from the external storage device 71 via the external storage device controller 7 (not shown) and this image data is printed by the printing unit 31 will be described. First, the compressed image data is read from the external storage device 71 and developed in the RAM 8. Next, the decompression unit 10 reads the compressed image data expanded in the RAM 8, performs decompression processing on the compressed image data, and writes the obtained image data back to the RAM 8. The expanded image data is read by the image processing unit 5, subjected to various image processing for printing, and then written back to the RAM 8. Finally, the print engine I / F 3 reads the image data after the image processing from the RAM 8 and transfers the image data to the printing unit 31 to perform the printing process.

  The main feature of the present invention is that, when an external storage device with a low transfer speed is connected, it is possible to select whether or not to continue using the external storage device by allowing the performance of the image forming device to be lowered by the user's intention. There is in doing so. As a configuration for this, the MFP 1 includes an external storage device controller 7 for detachably connecting the external storage device 71, and whether or not a new external storage device 71 is connected to the external storage device controller 7. A connection determination unit that is determined from the device-specific information, a data transfer rate calculation unit that calculates a data transfer rate of the external storage device 71 when it is determined that the external storage device 71 is newly connected, and a calculation A performance determination unit that compares the data transfer speed of the external storage device 71 and the data processing speed of the MFP 1 and determines whether or not a decrease in the data processing performance of the MFP 1 is expected based on the comparison result; If it is determined that a decrease in the data processing performance of the MFP 1 is expected, the fact is notified to the user and the data processing performance of the MFP 1 is allowed to decrease. And and a notification unit configured to select whether to use the external storage device 71 to the user.

  The functions as the connection determination unit, data transfer rate calculation unit, and performance determination unit are executed by the CPU 4, and the function as the notification unit is executed by the CPU 4 and the display unit 11. Specifically, a program for executing functions as a connection determination unit, a data transfer rate calculation unit, a performance determination unit, and a notification unit is stored in the ROM 9, and the CPU 4 executes the ROM 9 when executing this program. Are read out from the RAM and loaded into the RAM 8 for execution. Hereinafter, as an example of connection determination of a new external storage device by the connection determination unit, a case of replacement determination of an external storage device will be described as an example.

  FIG. 4 is a flowchart for explaining an operation example by the MFP 1 according to the embodiment of the present invention. First, the MFP 1 determines whether or not the external storage device 71 has been replaced (step S1). The detection of the exchange of the external storage device 71 is performed at the time of system startup, recovery from the sleep state, or the like. Specifically, it can be performed by acquiring device specific information of the external storage device 71. For example, when the system is stopped, system-specific information of the external storage device connected to the MFP 1 is acquired, and basic information such as device ID, manufacturer information, and capacity information included in the system-specific information is acquired in advance. . Then, at the next system startup, device specific information of the external storage device connected to the MFP 1 is acquired, and the device specific information at this time is compared with the previous device specific information, for example, whether the device ID has changed. judge. If the device ID has changed, it is determined that the external storage device has been replaced. If the device ID has not changed, it is determined that the external storage device has not been replaced.

  If YES in step S1, that is, if it is determined that the external storage device 71 has been replaced, the MFP 1 measures the actual data transfer performance of the external storage device 71 (step S2). If NO in step S1, the external storage device 71 has not been replaced, and the process is terminated as it is. Then, the MFP 1 calculates the data transfer speed of the external storage device 71 based on the actual data transfer performance of the external storage device 71 measured in step S2 (step S3). The processes in steps S2 and S3 are executed by the CPU 4. For example, when the data processing speed of the MFP 1 is determined in advance as the number of pages processed per unit time, the CPU 4 measures the data transfer amount per unit time by the external storage device 71 and measures the measured unit time per unit time. Based on the data transfer amount, the number of pages transferred per unit time is calculated as the data transfer rate of the external storage device 71.

  The process of step S2 will be described based on a specific example. First, the actual writing performance of the external storage device 71 is measured. For example, 100 MB of data is written to the external storage device 71, and the time taken for writing is measured by the timer function of the CPU 4. Specifically, the external storage device controller 7 has a DMA (Direct Memory Access) function, is set to perform a 100 MB write operation from the CPU 4 to the external storage device 71, and issues a DMA activation command from the CPU 4. receive. The CPU 4 issues a DMA start command and starts a timer, stops the timer when a DMA completion interrupt is received, and acquires the value (time) at that time. For example, if it takes 2 seconds to transfer 100 MB of data, the write transfer capability is 50 MB / s. By executing this data writing process a plurality of times by changing the write address, an accurate write performance is measured.

  Next, the actual read performance of the external storage device 71 is measured. This is basically the same as the measurement of the write performance described above, but the data transfer direction when the CPU 4 instructs the DMA is reversed and the data is set to be read from the external storage device 71. For example, the CPU 4 is set to perform a 100 MB read operation on the external storage device 71 and receives a DMA activation command from the CPU 4. The CPU 4 issues a DMA start command and starts a timer, stops the timer when a DMA completion interrupt is received, and acquires the value (time) at that time. For example, if it takes 2 seconds to transfer 100 MB of data, the read transfer capacity is 50 MB / s. By executing this data reading process a plurality of times by changing the reading address, the accurate reading performance is measured.

  The process of step S3 will be described based on a specific example. For example, it is assumed that the maximum image data size is 100 MB, and the worst compression rate (this is a compression rate varies depending on the image data and it is difficult to accurately define the compression rate) is 50%. In this case, since one page of data is 50 MB, it takes 1 second to write to the external storage device 71 as described above. Therefore, the external storage device 71 has a data writing speed of 60 pages / minute. That is, when the data reading speed of the scanner unit 21 of the MFP 1 is infinitely high, the data reading speed of the scanner unit 21 is 60 pages / minute.

  Similarly, in the case of reading data, it takes 1 second to read data from the external storage device 71. Therefore, the external storage device 71 has a data reading speed of 60 pages / minute. That is, when the data printing speed of the printing unit 31 of the MFP 1 is infinitely high, the data printing speed of the printing unit 31 is 60 pages / minute.

  Next, the MFP 1 compares the data transfer speed of the external storage device 71 calculated in step S3 with the data processing speed of the MFP 1, and based on the comparison result, whether or not a decrease in the data processing performance of the MFP 1 is expected. Is determined (step S4). Specifically, when the data transfer speed of the external storage device 71 is the data writing speed when writing data to the external storage device 71 and the data processing speed of the MFP 1 is the data reading speed of the scanner unit 21, the CPU 4 When the data writing speed of the external storage device 71 is compared with the data reading speed of the MFP 1 and the data writing speed of the external storage device 71 is slower than the data reading speed of the MFP 1, the data reading performance of the MFP 1 is expected to deteriorate. Is determined. When the data transfer speed of the external storage device 71 is the data read speed when reading data from the external storage device 71 and the data processing speed of the MFP 1 is the data print speed of the printing unit 31, the CPU 4 The data reading speed of 71 and the data printing speed of the MFP 1 are compared. If the data reading speed of the external storage device 71 is slower than the data printing speed of the MFP 1, it is determined that the data printing performance of the MFP 1 is expected to deteriorate.

  For example, it is assumed that the scanner performance of the MFP 1 is 40 pages / minute and the printing performance is also 40 pages / minute. Since both the read transfer performance (data read speed) and the write transfer performance (data write speed) of the external storage device 71 acquired in step S3 are 60 pages / minute, both are the processing performance of the MFP 1 (40 pages / minute). The transfer performance of the external storage device 71 does not become a bottleneck of the MFP 1. Accordingly, the data processing performance of the MFP 1 does not deteriorate.

  On the other hand, when both the read transfer performance (data read speed) and the write transfer performance (data write speed) of the external storage device 71 acquired in step S3 are 30 pages / min, the scanner performance and print performance of the MFP 1 are both used. (Both are 40 pages / minute), the transfer performance of the external storage device 71 becomes a bottleneck, and the processing performance of the scanner unit 21 is reduced to 30 pages / minute. This is because the reading process in the scanner unit 21 completes the reading process for one page at a speed of 40 pages / minute, but waits for the next page process to be started after the writing to the external storage device 71 is completed. Time is generated and the overall processing performance decreases. Similarly, the processing performance of the printing unit 31 is reduced to 30 pages / minute. This is because the printing process in the printing unit 31 completes the printing process for one page at a speed of 40 pages / minute, but after waiting for the reading from the external storage device 71 to be completed, the next page process is started. In the same manner as described above, a waiting time occurs, and the overall processing performance decreases.

  Next, in the case of YES in step S4, the MFP 1 displays a message as shown in FIG. 5 to notify the user that the data processing performance of the MFP 1 is expected to decline, and to perform the data processing of the MFP 1 It is selected whether or not the external storage device 71 is used while permitting a decrease in performance (step S5). If NO in step S4, the MFP 1 ends as it is not expected to decrease the data processing performance of the MFP 1. In this case, the external storage device 71 is used as it is. As described above, when it is determined that the data processing performance of the MFP 1 is expected to deteriorate, the MFP 1 notifies the user to that effect. At this time, the MFP 1 is limited by the data transfer speed of the external storage device 71. The specific processing performance may be notified of the data processing speed, that is, how many pages / minute the scanner performance and printing performance of the MFP 1 correspond to. For example, as described above, when the read transfer performance (data read speed) and the write transfer performance (data write speed) of the external storage device 71 are both 30 pages / minute, the scanner performance and print performance of the MFP 1 are both used. Therefore, the processing performance of the scanner unit 21 and the processing performance of the printing unit 31 are limited to 30 pages / min. The user is notified of the limited processing performance of 30 pages / minute.

  If the user selects “YES” in response to the notification shown in FIG. 5 displayed in step S5, the external storage device 71 can be used while allowing the data processing performance of the MFP 1 to be lowered. When “NO” is selected, the external storage device 71 is not used, and a response such as replacement to another external storage device is taken. In this way, the user can select whether to continue using the external storage device while allowing the performance of the MFP to be lowered, or to prepare a new external storage device according to the serviceman's response.

  Another embodiment of the present invention will be described. In this embodiment, in addition to the above configuration, a capacity determination unit that determines whether the storage capacity of the external storage device 71 satisfies the minimum capacity necessary for the operation of the MFP 1 is provided. The function as the capacity determination unit is executed by the CPU 4. Here, it is determined whether or not the storage capacity of the external storage device 71 satisfies the minimum capacity necessary for storing the program and data necessary for the operation of the MFP 1. Since the device 71 cannot be used, this is notified to the user. Further, when it is determined that the minimum capacity is satisfied and it is determined that the data processing performance of the MFP 1 is not expected to decrease, or when it is determined that the minimum capacity is satisfied and the notification of FIG. When the user selects to use the external storage device 71 while allowing the data processing performance to be lowered, it is necessary to define the storage area of the external storage device 71, so that the storage area used for data storage is Adjustable.

  FIG. 6 is a flowchart for explaining an operation example by the MFP 1 according to another embodiment of the present invention. First, the MFP 1 determines whether or not the external storage device 71 has been replaced (step S11). If YES in step S11, that is, if it is determined that the external storage device 71 has been replaced, the MFP 1 measures the actual data transfer performance of the external storage device 71 and acquires the storage capacity of the external storage device 71 ( Step S12). The storage capacity of the external storage device 71 can be acquired by, for example, obtaining configuration information by issuing a request to the external storage device 71 after the MFP 1 establishes a connection with the external storage device 71, and the configuration information What is necessary is just to acquire the storage capacity contained in. If NO in step S11, since the external storage device 71 has not been replaced, the process is terminated as it is.

  Next, the MFP 1 calculates the data transfer rate of the external storage device 71 based on the actual data transfer performance of the external storage device 71 measured in step S12 (step S13). Then, the MFP 1 compares the data transfer speed of the external storage device 71 calculated in step S13 with the data processing speed of the MFP 1, and based on the comparison result, whether or not a decrease in the data processing performance of the MFP 1 is expected. Is determined (step S14). If YES in step S14, the MFP 1 causes the display unit 11 to display the message as shown in FIG. 5 to notify that the data processing performance of the MFP 1 is expected to be reduced, and to reduce the data processing performance of the MFP 1. And whether or not to use the external storage device 71 is selected (step S15). If NO in step S14, the MFP 1 does not expect a decrease in the data processing performance of the MFP 1, and moves to step S17.

  Next, the MFP 1 determines whether or not to use the external storage device 71 while allowing the data processing performance of the MFP 1 to be lowered based on the user's selection for the notification of FIG. 5 displayed in step S15 (step S15). Step S16). If the user selects “YES” in FIG. 5 (YES in step S16), it is determined that the data storage performance of the MFP 1 is allowed to be used and the external storage device 71 is used, and the process proceeds to step S17. Further, when the user selects “NO” in FIG. 5 (NO in step S16), the process ends as it is, and the external storage device 71 is not used, and measures such as replacement with another external storage device are taken. become.

  Then, the MFP 1 determines whether or not the storage capacity of the external storage device 71 is insufficient with respect to the minimum capacity necessary for the operation of the MFP 1 (step S17). Since this external storage device cannot be used, the fact is notified to the user, and the process ends as it is (step S18). If NO in step S17, since the storage capacity of the external storage device 71 satisfies the minimum capacity, the storage area used for data storage in the external storage device 71 is adjusted (step S19). The storage area adjustment in step S19 may be performed according to a user operation or may be performed according to a mode preset by the user.

  As described above, when the CPU 4 determines that the storage capacity of the external storage device 71 does not satisfy the minimum capacity, the external storage device 71 cannot be used. In addition, when it is determined that the data processing performance of the MFP 1 is not expected to deteriorate and the storage capacity of the external storage device 71 is determined to satisfy the minimum capacity, the storage used for data storage of the external storage device 71 The area can be adjusted. Further, in response to the notification shown in FIG. 5, the user selects to use the external storage device 71 while allowing the data processing performance of the MFP 1 to decrease, and the storage capacity of the external storage device 71 satisfies the minimum capacity. If it is determined, the storage area used for saving data in the external storage device 71 can be adjusted.

  FIG. 7 is a diagram for explaining an example of adjusting the storage area used for storing data in the external storage device 71. In the case of NO in step S17 in the flow of FIG. 6, the newly connected external storage device 71 can be used, so it is necessary to define a storage area. In this example, it is assumed that the storage area required to store the program is 1 GB, the storage area required to store temporarily stored data is 3 GB, and the minimum capacity required for the operation of the MFP 1 is 4 GB.

  Here, the program data is a program code for the CPU 4 to control the operation of the MFP 1 and is read when the system is activated. Since it is indispensable data for operating the system, it is necessary to secure a storage area. However, if the program data is stored in another storage device, the area need not be secured.

  Temporary storage data is image data temporarily stored in scanner processing, copy processing, print processing, and the like. For example, in the process of copying five copies of five originals, the same original is not scanned five times, but after five originals are temporarily stored in the external storage device 71, five print processes are performed. Execute. In this way, the captured image data is always stored in the temporary storage area and reused. However, since it is temporarily stored, it is deleted at various timings, such as deleting every time a job is completed, or deleting at shutdown.

  Further, the file data is data that is saved / erased by a user's instruction, unlike the above-described temporarily saved data. It is data that can be accessed and controlled from various terminal devices such as a PC connected to a network as well as being able to be saved and recalled by the user interface operation of the MFP 1.

  In addition, it is necessary to secure various data areas such as file system data, job log data, and application data, but they are omitted here for the sake of simplicity. In the case of this example, an area for program data is necessarily required, and an external storage device that cannot secure the capacity for this area cannot be used. For example, in a system with a program data size of 1 GB, a 512 MB external storage device cannot be connected. The area for temporarily stored data is also an indispensable area for realizing the system. For example, assuming that the maximum image data size is 100 MB and the worst compression rate is 50%, a 3 GB area is required to temporarily store 60 sheets of document data.

  In FIG. 7, when an 8 GB external storage device 71 is connected as shown in FIG. 7A, 1 GB as a program area, 3 GB as a temporary storage area are secured first, and the remaining 4 GB becomes a file area. If an external storage device of 8 GB or more is connected, the file area will increase. Next, a case where the storage capacity is close to the minimum size is shown. When an external storage device with a storage capacity of 4 GB is newly connected, as shown in FIG. 7B, if 1 GB is secured as the program area and 3 GB is secured as the temporary storage area, the file area cannot be secured.

  Therefore, a “system performance priority mode” and a “file area priority mode” are prepared as modes preset by the user. In the “system performance priority mode”, as shown in FIG. 7B, by ensuring 3 GB of the temporary storage area, the system operates without degrading the performance of the system that forms the basis of the MFP 1, such as scanner, copy, and print. It becomes possible. However, since the file area is not secured, the file sharing function is limited.

  The “file area priority mode” is an operation mode in which a temporary storage area is minimized and a file area can be secured as much as possible. For example, a 1.5 GB file area is secured by limiting the temporary storage area to half of 1.5 GB. At this time, the region configuration is as shown in FIG. By minimizing the temporary storage area, for example, the normal temporary storage area of 60 sheets is reduced to half, 30 sheets, which affects the number of copies that can be processed at one time, the number of stored jobs, etc. However, the file sharing function can be used by providing a file area although the number is small.

  As described above, when it is determined that a decrease in the data processing performance of the MFP is expected, in addition to notifying the user of this, when the storage capacity of the external storage device does not satisfy the minimum capacity, This is notified to the user, so that the user can easily know whether or not the exchanged external storage device is usable. When the storage capacity of the external storage device satisfies the minimum capacity, the storage area of the external storage device can be easily adjusted according to the user's intention and usage pattern.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus (MFP), 2 ... Scanner I / F, 3 ... Print engine I / F, 4 ... CPU, 5 ... Image processing part, 6 ... Compression part, 7 ... External storage device controller, 8 ... RAM, DESCRIPTION OF SYMBOLS 9 ... ROM, 10 ... Decompression part, 11 ... Display part, 21 ... Scanner part, 31 ... Printing part, 71 ... External storage device.

Claims (10)

An image forming apparatus provided with an external storage device interface for detachably connecting an external storage device,
A connection determination unit that determines whether or not a new external storage device is connected to the external storage device interface from device-specific information of the external storage device, and it is determined that the external storage device is newly connected The data transfer rate calculation unit for calculating the data transfer rate of the external storage device, the calculated data transfer rate of the external storage device and the data processing rate of the image forming device, and the comparison result And a performance determination unit that determines whether or not a decrease in data processing performance of the image forming apparatus is expected, and if it is determined that a decrease in data processing performance of the image forming apparatus is expected, the user And a notification unit that allows a user to select whether to use the external storage device while allowing a decrease in data processing performance of the image forming apparatus. An image forming apparatus comprising and.   If the performance determination unit determines that the data processing performance of the image forming apparatus is expected to deteriorate, the notification unit determines the data processing speed of the image forming apparatus that is limited by the data transfer speed of the external storage device. The image forming apparatus according to claim 1, wherein the image forming apparatus notifies the user.   The data processing speed of the image forming apparatus is the number of pages processed per unit time, and the data transfer speed calculation unit measures the data transfer amount per unit time by the external storage device, and the measured unit 3. The image forming apparatus according to claim 1, wherein the number of pages transferred per unit time is calculated as a data transfer rate of the external storage device based on a data transfer amount per time.   The data transfer speed of the external storage device is the data writing speed when data is written to the external storage device, and the data processing speed of the image forming apparatus is the data reading speed of the scanner unit included in the image forming apparatus. And the performance determination unit compares the data writing speed of the external storage device with the data reading speed of the image forming apparatus, and the data writing speed of the external storage device is greater than the data reading speed of the image forming apparatus. 3. The image forming apparatus according to claim 1, wherein when it is late, it is determined that a decrease in data reading performance of the image forming apparatus is expected.   The data transfer speed of the external storage device is a data reading speed when reading data from the external storage device, and the data processing speed of the image forming apparatus is a data printing speed of a printing unit included in the image forming apparatus. The performance determination unit compares the data reading speed of the external storage device with the data printing speed of the image forming apparatus, and when the data reading speed of the external storage device is slower than the data printing speed of the image forming apparatus, The image forming apparatus according to claim 1, wherein it is determined that a decrease in data printing performance of the image forming apparatus is expected.   A capacity determination unit that determines whether or not the storage capacity of the external storage device satisfies a minimum capacity necessary for the operation of the image forming apparatus, and the storage capacity of the external storage device is set to a minimum capacity by the capacity determination unit; The image forming apparatus according to claim 1, wherein when it is determined that the condition is not satisfied, the notification unit notifies the user to that effect.   When it is determined by the performance determination unit that a decrease in data processing performance of the image forming apparatus is not expected, and the storage determination unit determines that the storage capacity of the external storage device satisfies the minimum capacity, The image forming apparatus according to claim 6, wherein a storage area used for storing data in the external storage device can be adjusted.   The user selects to use the external storage device while allowing the data processing performance of the image forming apparatus to be reduced in response to the notification from the notification unit, and the capacity determination unit stores the storage capacity of the external storage device. The image forming apparatus according to claim 6, wherein a storage area used for storing data in the external storage device can be adjusted when it is determined that satisfies a minimum capacity.   9. The image forming apparatus according to claim 7, wherein adjustment of a storage area used for storing data in the external storage device is performed according to a user operation.   9. The image forming apparatus according to claim 7, wherein adjustment of a storage area used for data storage of the external storage device is performed according to a mode preset by a user.

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