Output device and image forming apparatus

Abstract

This image forming device (1) comprises: a USB connector (7) connected to a terminal device (40) via a cable; a FIFO (24); and a control unit (10) functioning as a control unit (100) that alternatively executes either a normal mode or a power saving mode. When running in the power saving mode and receiving data transmitted from the terminal device (40) via the cable, the control unit (100) temporarily stores data in the FIFO (24) to temporarily wait for the execution of processing according to the data, checks the data stored in the FIFO (24) at predetermined time intervals in seconds, and executes processing based on the data.

Description

Technical Field

[0001] The present invention relates to power saving of output devices such as image forming apparatuses.

Background Art

[0002] There is known an image forming apparatus such as a printer that receives data from a PC (Personal Computer) connected via a USB (Universal Serial Bus) cable and generates a printed matter. Further, there is known an image forming apparatus that can alternatively execute a plurality of operation modes having different power consumption amounts (for example, a normal mode and a power saving mode). For example, when a print command is received from a PC while in the power saving mode, there is known an image forming apparatus that shifts from the power saving mode to the normal mode and executes processing based on the print command to generate a printed matter.

[0003] Patent Document 1 discloses a technique for storing a command received from a PC in a buffer in a printer connectable to the PC via a USB cable, checking whether a command is stored in the buffer when a polling time arrives, and returning from the power saving mode when the command is confirmed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] By the way, data that is not meaningful to the user, such as a print command, may be transmitted from the PC to the image forming apparatus instead of data that is meaningful to the user. For example, the PC may periodically transmit data for checking whether communication with the image forming apparatus is possible to the output device.

[0006] When the image forming apparatus shifts to the power saving mode, even if it receives data that is not very meaningful to such a user, it supplies power to a part of the circuit and executes processing according to the received data. For example, the image forming apparatus resumes the main memory from the power saving state and transmits response data for the received data to the PC. As a result, since power is supplied to a part of the circuit, the power consumption increases.

[0007] Patent Document 1 discloses a technique in a printer of storing a command received from a PC in a buffer and checking the inside of the buffer when a polling time arrives. That is, Patent Document 1 discloses a technique of reducing the execution frequency of the confirmation process for the buffer to achieve power saving.

[0008] However, since the polling time is estimated to be in milliseconds, the execution frequency of the above confirmation process is not low, and the power saving effect is not very high. In addition, the circuit of the polling timer that measures the polling time has a higher operating speed than the circuit of a general timer that measures in seconds. Therefore, compared with a general timer, the power consumption is large and the power saving effect is low.

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to further reduce power consumption in the power saving mode in an output device that receives data transmitted from a terminal device connected via a cable.

[0010] An output device according to an aspect of the present invention includes a connector connected to a terminal device via a cable, a buffer, and a control unit that selectively executes either a normal mode or a power saving mode with less power consumption than the normal mode. When the control unit receives data transmitted from the terminal device via the cable while executing the power saving mode, it temporarily stores the data in the buffer and temporarily waits for the execution of the processing according to the data, and at a predetermined time interval in seconds, it checks the data stored in the buffer and executes the processing based on the data.

[0011] An image forming apparatus according to another aspect of the present invention includes the above output device and an image forming unit that forms an image on a recording medium.

Advantages of the Invention

[0012] According to the present invention, when the power saving mode is being executed, data transmitted from a terminal device via a cable is temporarily stored in a buffer, and processing corresponding to the data is not immediately executed but is executed after being temporarily waited. As a result, it is possible to maintain a longer time with less power consumption than when immediately executing the processing corresponding to the data, and further power saving can be achieved. In addition, since the waiting time is in seconds instead of the general millisecond unit, the power saving effect is high. Further, since a timer with a high operating speed (i.e., a timer with a large power consumption) is not required, further power saving can be achieved.

[0013] If the processing corresponding to the data transmitted from the terminal device is temporarily waited, the execution of the processing may be delayed and the convenience may be reduced. However, the waiting is performed only in the power saving mode, and the waiting is not performed in the normal mode. Therefore, a significant reduction in convenience can be suppressed.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

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Figure 6

Embodiments for Carrying Out the Invention

[0015] (First Embodiment) Hereinafter, an output device and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram schematically showing the main internal configuration of the image forming apparatus 1 according to the first embodiment of the present invention. The image forming apparatus 1 is a multifunction machine having a plurality of functions such as, for example, a copying function, a printer function, a scanner function, and a facsimile function. The image forming apparatus 1 is an example of an output device in the claims.

[0016] The image forming apparatus 1 includes a control unit 10, a document feeder 6, a document reading unit 5, an image forming unit 12, a fixing unit 13, a paper feeding unit 14, an operation unit 47, a USB connector 7, and a storage unit 8.

[0017] The document feeder 6 is configured to be openable and closable by a hinge or the like on the upper surface of the document reading unit 5. The document feeder 6 functions as a document pressing cover when reading a document placed on the platen glass. The document feeder 6 is an ADF (Auto Document Feeder). The document feeder 6 includes a document placement tray and supplies the document placed on the document placement tray to the document reading unit 5.

[0018] A case where a document reading operation is performed in the image forming apparatus 1 will be described. The document reading unit 5 optically reads the image of the document supplied to the document reading unit 5 by the document feeder 6 or the document placed on the platen glass, and generates image data. The image data generated by the document reading unit 5 is stored in an image memory or the like.

[0019] A case where an image forming operation is performed by the image forming apparatus 1 will be described. Based on the image data generated by the original document reading operation, the image data stored in the image memory or the like, or the image data received from a computer connected to the network, the image forming unit 12 forms a toner image on a recording paper as a recording medium fed from the paper feeding unit 14.

[0020] The fixing unit 13 heats and presses the recording paper on which the toner image is formed by the image forming unit 12 to fix the toner image on the recording paper. The recording paper subjected to the fixing process is discharged to the discharge tray. The paper feeding unit 14 includes a paper feed cassette.

[0021] The operation unit 47 receives instructions from the user, such as an instruction to execute an image forming operation, regarding various operations and processes that can be executed by the image forming apparatus 1. The operation unit 47 includes a display unit 473 for displaying operation guidance to the user and the like. The operation unit 47 receives an input of the user's instruction based on an operation (touch operation) by the user on the operation screen displayed on the display unit 473 via the touch panel provided in the display unit 473 or an operation by the user on a physical key.

[0022] The display unit 473 is composed of an LCD (Liquid Crystal Display) or the like. The display unit 473 includes a touch panel. When the user performs an operation of touching a button or a key displayed on the screen, the touch panel receives an instruction associated with the touched position.

[0023] The USB connector 7 is a USB connector for connecting the image forming apparatus 1 and a terminal device 40 such as a PC which is an external device. A USB cable 50 is connected to the USB connector 7. The image forming apparatus 1 performs data communication with the terminal device 40 via the USB cable 50.

[0024] The storage unit 8 is a large-capacity storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The storage unit 8 stores various control programs and the like.

[0025] The control unit 10 includes a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and a dedicated hardware circuit. The processor is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an MPU (Micro Processing Unit), etc. The control unit 10 is provided with a buffer 101 and a timer 102.

[0026] The control unit 10 functions as a control unit 100 by the operation of the above-mentioned processor according to the control program stored in the storage unit 8. However, the control unit 100 can also be configured by a hardware circuit without depending on the operation according to the control program by the control unit 10. The same applies to each embodiment hereinafter unless otherwise specified.

[0027] The control unit 100 is in charge of the overall operation control of the image forming apparatus 1. The control unit 100 is connected to the document feeder 6, the document reading unit 5, the image forming unit 12, the fixing unit 13, the paper feeding unit 14, the operation unit 47, the USB connector 7, and the storage unit 8, and performs drive control and the like of these units. For example, the control unit 100 controls the operation of the image forming unit 12 and the like to form the document image indicated by the image data obtained by the reading by the document reading unit 5 on the recording paper as the recording medium. The control unit 100 controls the operation of the image forming unit 12 and the like according to the print command transmitted from the terminal device 40 via the USB connector 7 to form an image on the recording paper as the recording medium.

[0028] The control unit 100 alternatively executes a plurality of modes with different power consumption levels (here, the normal mode and the power-saving mode). The normal mode is a mode for causing the image forming apparatus 1 to perform default operations without reducing power consumption. The power-saving mode is a mode for causing the image forming apparatus 1 to perform operations with less power consumption than the normal mode.

[0029] The buffer 101 is composed of a FIFO (First-In First Out) memory or the like. The buffer 101 temporarily stores data transmitted from the terminal device 40 via the USB cable 50 when the power-saving mode is being executed. The timer 102 is a general timer that measures time in seconds.

[0030] When the control unit 100 operates each operation mechanism of the image forming apparatus 1 in the power-saving mode, it temporarily waits for the execution of processing according to the data transmitted from the terminal device 40. Based on the time measured by the timer 102, the control unit 100 checks the data stored in the buffer 101 at a predetermined time interval T in seconds (for example, a predetermined time interval much longer than the time interval used to check whether data has arrived by a polling timer), and executes processing according to the data. That is, when the control unit 100 is executing the power-saving mode, even if it receives data from the terminal device 40, it does not start executing the processing according to the data immediately after reception, but delays the start of execution.

[0031] As the buffer 101, a memory having a capacity sufficient to accumulate data transmitted from the terminal device 40 at the time interval T is used.

[0032] FIG. 2 is a diagram schematically showing an example of the internal structure of the ASIC constituting the control unit 10 and its peripheral parts. The printer ASIC 20 includes a CPU 21, a RAMC 22 which is a memory controller, and a USB PHY (physical layer) 23.

[0033] The USB PHY 23 performs data communication (specifically, packet communication) with the terminal device 40 via the USB cable 50 connected to the USB connector 7. The USB PHY 23 includes a FIFO (First In First Out) 24 as the buffer 101. The USB PHY 23 converts, for example, an electrical signal transmitted from the terminal device 40 into a digital signal and outputs it to the CPU 21, the RAMC 22, or the FIFO 24. The USB PHY 23 further converts the digital signal into an electrical signal and transmits it toward the terminal device 40. The data output to the RAMC 22 is transferred to the RAM 30, which is the main memory, as necessary.

[0034] FIG. 3 is a diagram for explaining the data flow when the image forming apparatus 1 is in the normal mode. When the image forming apparatus 1 is in the normal mode, when the USB PHY 23 receives data from the terminal device 40, the control unit 100 (see FIG. 1) causes the USB PHY 23 to output the received data to the CPU 21 or the RAMC 22 as necessary, or to transmit response data from the USB PHY 23 toward the terminal device 40.

[0035] FIGS. 4A and 4B are diagrams for explaining the data flow when the image forming apparatus 1 is in the power saving mode. FIG. 4A shows a situation when the USB PHY 23 is receiving data from the terminal device 40, and FIG. 4B shows a situation when the control unit 100 is executing processing according to the data stored in the FIFO 24.

[0036] When the image forming apparatus 1 is in the power saving mode, when the USB PHY 23 receives data from the terminal device 40, the USB PHY 23 stores the received data in the FIFO 24 as shown in FIG. 4A.

[0037] When the control unit 100 shifts from the normal mode to the power-saving mode, it activates the timer 102. When in the power-saving mode, the control unit 100 determines whether data is stored in the FIFO 24 every time a predetermined time interval T elapses based on the time measured by the timer 102. When the control unit 100 determines that data is stored in the FIFO 24, it executes processing according to the data (i.e., predetermined processing to be performed on the data). For example, as shown in FIG. 4B, the control unit 100 causes the FIFO 24 to output the stored data to the CPU 21 or the RAMC 22 as needed, causes the CPU 21 or the RAMC 22 to execute data processing, or causes the USB PHY 23 to transmit response data to the terminal device 40.

[0038] The control unit 100 also determines whether it is necessary to perform processing according to the data stored in the FIFO 24. If the control unit 100 determines that processing according to the data is necessary, it performs the processing; if it determines that it is not necessary, it does not perform the processing. When the data stored in the FIFO 24 is a print command, since the data includes print data, the data volume becomes a certain size. In other words, data with a small data volume can be said to be data for which processing according to the data is not necessary. Therefore, the control unit 100 determines that data with a data volume equal to or greater than a predetermined volume is data for which processing according to the data is necessary.

[0039] Next, a data confirmation process for the control unit 100 to confirm the data stored in the FIFO 24 will be described with reference to the flowchart shown in FIG. 5 and the like. Note that the control unit 100 executes the data confirmation process every time interval T measured by the timer 102 when in the power-saving mode.

[0040] The control unit 100 determines whether data is stored in the FIFO 24 (step S1). When the control unit 100 determines that data is stored in the FIFO 24 (YES in step S1), it determines whether the data contains data that requires processing (step S2). On the other hand, when the control unit 100 determines that no data is stored in the FIFO 24 (NO in step S1), it ends the data confirmation process.

[0041] When the control unit 100 determines that the data contains data that requires processing (YES in step S2), it executes processing according to the data determined to require processing (step S3) and ends the data confirmation process. On the other hand, when the control unit 100 determines that the data does not contain data that requires processing (NO in step S2), it ends the data confirmation process.

[0042] According to the first embodiment, data transmitted from the terminal device 40 via the USB cable 50 when the power saving mode is being executed is temporarily stored in the FIFO 24, and execution of processing according to the data is temporarily suspended. As a result, it is possible to maintain a long period of time with low power consumption, and further power saving can be achieved. Also, since the standby time is in seconds as described above instead of in the general millisecond (msec) unit used when checking whether data has arrived using a polling timer, the power saving effect is high. Also, since the time interval T is set to a predetermined time interval that is much longer than the general time interval used when checking whether data has arrived using a polling timer, a timer with a high operating speed (i.e., a timer with high power consumption) is not required. Therefore, further power saving can be achieved.

[0043] Further, the control unit 100 determines whether the data stored in the FIFO 24 needs to be processed based on the amount of data. If it is determined that the data needs to be processed, the control unit 100 performs the processing. If it is determined that the data does not need to be processed, the control unit 100 does not perform the processing. That is, the control unit 100 surely executes the processing that should be immediately executed, and for the processing that does not need to be immediately executed, it is performed only every time interval T, so as to prevent the power from being wastedly supplied to the RAMC 22 or the RAM 30 and prevent the power consumption from increasing.

[0044] Note that if the processing corresponding to the data transmitted from the terminal device 40 is temporarily waited for, the execution of the processing may be delayed and the convenience may be reduced. However, such waiting is performed only in the power saving mode and not in the normal mode. Therefore, a large reduction in convenience can be suppressed.

[0045] (Second Embodiment) Next, the image forming apparatus 1 according to the second embodiment will be described. FIG. 6 is a functional block diagram schematically showing the main internal configuration of the image forming apparatus 1 according to the second embodiment. In the description of the second embodiment, the description of the same configuration and processing as those in the first embodiment will be omitted. The image forming apparatus 1 according to the second embodiment is different from the image forming apparatus 1 according to the first embodiment shown in FIG. 1 in that the control unit 10 functions as a change unit 103 and a selection reception unit 104.

[0046] The control unit 10 functions as a control unit 100, a change unit 103, and a selection reception unit 104 by the operation of the processor according to the control program stored in the storage unit 8.

[0047] The change unit 103 changes the length of the time interval T according to the usage environment of the image forming apparatus 1. For example, since it is expected that the usage frequency of the image forming apparatus 1 will be high from 9:00 am to 5:00 pm on weekdays, the change unit 103 shortens the time interval T for this time period and lengthens the time interval T for other time periods. Thereby, an apparatus excellent in the balance between power saving and convenience can be realized. For example, the change unit 103 follows the specified time period and the specified value indicating how much to shorten the time interval T, which are input to the operation unit 47 by the user's operation, regarding the time period for shortening the time interval T and how much to shorten the time interval T.

[0048] The selection reception unit 104 receives a user selection as to whether to enable or disable a function for temporarily waiting for the execution of processing according to the data transmitted from the terminal device 40. For example, the selection reception unit 104 receives the user selection via the operation unit 47.

[0049] The control unit 100 enables or disables the above function according to the user selection received by the selection reception unit 104. Thereby, it is possible to further prevent a decrease in user convenience.

[0050] (Third Embodiment) Incidentally, the terminal device 40 may have a timeout function. The timeout function is a function for ending the connection relationship when there is no response from the other party of the data communication even after a predetermined fixed time has elapsed. This function is originally assumed that some trouble has occurred on the other party.

[0051] However, as described in the above embodiment, when the data transmitted from the terminal device 40 is temporarily stored in the FIFO 24 and the execution start of the process corresponding to the data is delayed by waiting for the time interval T, there is a possibility that the terminal device 40 may utilize the timeout function and terminate the connection relationship with the image forming apparatus 1 even though there is no trouble in the image forming apparatus 1. In such a case, when the terminal device 40 receives the response data transmitted from the image forming apparatus 1 after the elapse of the time interval T, an inconsistency occurs, and there is a possibility that some problem may occur.

[0052] On the other hand, in the image forming apparatus 1 according to the third embodiment, when the process corresponding to the data stored in the FIFO 24 is a process of transmitting response data for the data to the terminal device 40, the control unit 100 transmits, via the cable 50, information indicating that the data has been normally received to the terminal device 40 when the data is received via the cable 50. Thereby, it is possible to prevent the occurrence of the above problem. Note that the configuration of the image forming apparatus 1 according to the third embodiment may be any of the configurations shown in the first and second embodiments.

[0053] The terminal device 40 is provided with a function for appropriately responding to the above information. For example, the function is provided in the printer driver installed in the terminal device 40 for controlling the image forming apparatus 1.

[0054] (Fourth Embodiment) In the image forming apparatus 1 according to the fourth embodiment, when shifting to the power saving mode, the control unit 100 transmits, via the cable 50, information indicating that the execution of the process corresponding to the data transmitted from the terminal device 40 is temporarily suspended to the terminal device 40. Thereby, it is possible to prevent the occurrence of the above problem. Note that the configuration of the image forming apparatus 1 according to the fourth embodiment may be any of the configurations shown in the first and second embodiments.

[0055] The terminal device 40 is provided with a function for appropriately responding to the above information. For example, similar to the case described in the third embodiment above, the above function is provided in the printer driver.

[0056] (Fifth Embodiment) In the image forming apparatus 1 according to the fifth embodiment, the control unit 100 sets the length of the time interval T to be shorter than the timeout time when connecting to the image forming apparatus 1, which is set in the terminal device 40. For example, when the control unit 100 connects to the terminal device 40 in which the timeout time is set to 5 seconds, the control unit 100 sets the time interval T to less than 5 seconds. When the control unit 100 connects to the terminal device 40 in which the timeout time is set to 3 seconds, the control unit 100 sets the time interval T to less than 3 seconds. Thereby, it is possible to prevent the occurrence of the above problem. Note that the configuration of the image forming apparatus 1 according to the fifth embodiment may be any of the configurations shown in the first and second embodiments.

[0057] By performing the procedures as described in the third to fifth embodiments above, appropriate power saving for the image forming apparatus 1 can be realized regardless of the host terminal device 40.

[0058] The present invention is not limited to the configurations of the above embodiments, and various modifications are possible. In the above embodiments, an image forming apparatus, which is a multifunction device, is used as the output device according to the present invention, but this is merely an example. The output device according to the present invention may be another output device that performs output processing according to data received from the terminal device 40, such as a printer.

[0059] The configurations and processes of the above embodiments shown in FIGS. 1 to 6 are merely one embodiment of the present invention, and are not intended to limit the present invention to such configurations and processes.

Claims

1. A connector connected to a terminal device via a cable, A buffer, A control unit that alternatively executes either a normal mode or a power saving mode with less power consumption than the normal mode, The control unit, When receiving data transmitted from the terminal device via the cable while executing the power saving mode, the data is temporarily stored in the buffer to temporarily wait for the execution of processing according to the data, and at a predetermined time interval in seconds, the data stored in the buffer is checked and processing based on the data is executed. An output device that determines whether it is necessary to perform processing based on the data stored in the buffer according to the amount of the data, performs the processing if it is determined to be necessary, and does not perform the processing if it is determined not to be necessary.

2. A connector connected to a terminal device via a cable, A buffer, A control unit that alternatively executes either a normal mode or a power saving mode with less power consumption than the normal mode, When the control unit receives data transmitted from the terminal device via the cable while executing the power saving mode, the data is temporarily stored in the buffer to temporarily wait for the execution of processing according to the data, and at a predetermined time interval in seconds, the data stored in the buffer is checked and processing based on the data is executed. An operation unit for inputting a user instruction, A selection reception unit that receives a user selection via the operation unit as to whether to enable or disable a function for temporarily waiting for the execution of processing according to the data transmitted from the terminal device, The control unit enables or disables the function according to the user selection received by the selection reception unit. An output device.

3. A connector connected to a terminal device via a cable, A buffer, And a control unit that alternatively executes either a normal mode or a power saving mode with less power consumption than the normal mode, The control unit, When receiving data transmitted from the terminal device via the cable while executing the power saving mode, the data is temporarily stored in the buffer to temporarily wait for the execution of processing according to the data, and at a predetermined time interval in seconds, the data stored in the buffer is checked, and processing based on the data is executed. When the processing according to the data is a process of transmitting response data to the terminal device for the data, when receiving the data via the cable, information indicating that the response data has been normally received is transmitted to the terminal device via the cable. An output device.

4. A connector connected to a terminal device via a cable, A buffer, And a control unit that alternatively executes either a normal mode or a power saving mode with less power consumption than the normal mode, The control unit, When receiving data transmitted from the terminal device via the cable while executing the power saving mode, the data is temporarily stored in the buffer to temporarily wait for the execution of processing according to the data, and at a predetermined time interval in seconds, the data stored in the buffer is checked, and processing based on the data is executed. When shifting to the power saving mode, information indicating that the execution of processing according to the data transmitted from the terminal device is temporarily waited is transmitted to the terminal device via the cable. An output device.

5. An output device, A connector connected to a terminal device via a cable, A buffer, A control unit that alternatively executes either a normal mode or a power saving mode with lower power consumption than the normal mode, The control unit, When receiving data transmitted from the terminal device via the cable while the power saving mode is being executed, temporarily stores the data in the buffer to temporarily wait for the execution of processing according to the data, and checks the data stored in the buffer at a predetermined time interval in seconds and executes processing based on the data, An output device that sets the length of the time interval to be shorter than the timeout time when connecting to the output device, which is set in the terminal device.

6. A connector connected to a terminal device via a cable, A buffer, A control unit that alternatively executes either a normal mode or a power saving mode with lower power consumption than the normal mode, The control unit, When receiving data transmitted from the terminal device via the cable while the power saving mode is being executed, temporarily stores the data in the buffer to temporarily wait for the execution of processing according to the data, and checks the data stored in the buffer at a predetermined time interval in seconds and executes processing based on the data, An output device that performs processing according to the data when the amount of the data is equal to or more than a predetermined amount, and does not perform the processing when the amount of the data is less than the predetermined amount.

7. An image forming apparatus comprising the output device according to claim 1, An image forming unit that forms an image on a recording medium.

Images