Patent Grant
8837973
1. Field of the Invention
The present invention relates to an image processing apparatus having power saving control, a control method thereof, and a storage medium.
2. Description of the Related Art
Recently, computer peripheral devices including printers have been required to reduce the energy consumption from the viewpoint of global environment preservation. As the international standards, a peripheral device satisfying predetermined conditions is required to automatically transit to a low power consumption state. Accordingly, energy saving and user friendliness are important themes of device development.
Also, a device having an automatic power-off function in order to reduce the power consumption even in the lower power consumption state has been developed. Especially in recent years, energy saving leads to the saving of electricity charge and the reduction in CO2 exhaustion amount, so users are taking a growing interest. In addition, enterprises cannot ignore energy saving as social responsibility regardless of the enterprise scales, and are extensively developing energy saving techniques.
As a method of controlling the transition to the lower power consumption state, Japanese Patent Laid-Open No. 2008-142942 has described a method of performing the control when a predetermined time has elapsed after a printing operation is stopped. In this method, a time zone in which no printing is performed is preset. When transiting to a sleep mode, the power source is turned off if the time is in this predetermined time zone; if not, the control transits to the sleep mode.
Unfortunately, the above-mentioned prior art has the following problems. In the above prior art, in the control of transiting to the sleep mode if no printing operation is performed for a predetermined time, a time zone during which no printing is performed is preset, and the power source is turned off if the time is in this predetermined time zone; if not, the control transits to the sleep mode. That is, when transiting to the sleep mode or power-off mode, a time zone during which no printing is performed is predetermined, and judgment is performed based on the range of this time zone alone.
Also, when the power source is once turned off, it takes a long time to return to a usable state, unlike when standing by in the sleep state. Especially when using a printer across a network, many users use the printer, so it is difficult to grasp the use statuses of all the users. In addition, some apparatuses consume high power when the power source is turned on or off. Therefore, the energy saving effect worsens if ON and OFF of the power source occur within a short time.
The present invention enables realization of an image processing apparatus that performs a process of transiting to a power-off state or sleep state in accordance with the connected state of an interface, a control method thereof, and a storage medium.
One aspect of the present invention provides an image processing apparatus comprising a plurality of interfaces for connecting an external apparatus, comprising: a confirmation unit configured to confirm, in a case where a condition for changing a power state of the image processing apparatus is satisfied, an interface which is able to communicate with an external apparatus; a determination unit configured to determine, based on a confirmation result by the confirmation unit, whether or not the image processing apparatus transits to a sleep state in which at least one of the plurality of interfaces is communicable; and a power control unit configured to transit the image processing apparatus to the sleep state if the determination unit has determined that the image processing apparatus transits to the sleep state, and transit the image processing apparatus to a power-off state in which the plurality of interfaces are incommunicable if the determination unit has determined that the image processing apparatus does not transit to the sleep state.
Another aspect of the present invention provides a control method for an image processing apparatus comprising a plurality of interfaces for connecting an external apparatus, comprising: confirming, by a confirmation unit, in a case where a condition for changing a power state of the image processing apparatus is satisfied, an interface which is able to communicate with an external apparatus; determining, by a determination unit, based on a confirmation result by the confirmation unit, whether or not the image processing apparatus transits to a sleep state in which at least one of the plurality of interfaces is communicable; and controlling, by a power control unit, to transit the image processing apparatus to the sleep state if the determination unit has determined that the image processing apparatus transits to the sleep state, and transit the image processing apparatus to a power-off state in which the plurality of interfaces are incommunicable if the determination unit has determined that the image processing apparatus does not transit to the sleep state.
Still another aspect of the present invention provides a computer-readable storage medium storing a computer program for causing a computer to execute each step in a control method for an image processing apparatus.
Further features of the present invention will be apparent from the following description of exemplary embodiments with reference to the attached drawings.
Embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.
<First Embodiment>
<Arrangement of Image Processing Apparatus>
The first embodiment of the present invention will be explained below with reference to
The printer 2 receives data from various external apparatuses such as host computers, and executes printing on a printing medium. In this embodiment, a laser beam printer is applied to the printer 2. However, the present invention is not limited to this, and applicable to any image processing apparatus connectable to a network.
The printer 2 receives print information (for example, a character code), form pattern information, or compressed image data supplied from a connected external host computer. The input image data is stored, and a corresponding character pattern or form pattern is formed in accordance with the information, or an image is formed on printing paper as a printing medium while the compressed image data is rasterized.
The operation panel 200 includes switches and LED indicators for various operations. The printer control unit (controller) 201 executes overall control in the printer 2, and analyzes character information and the like supplied from a host computer or the like. The printer control unit 201 mainly converts character information into a video signal having a corresponding character pattern, and transfers compressed image data to the laser scanner unit 209 while rasterizing the data.
When printing is started, the printer 2 starts a paper feed operation of feeding printing paper into the apparatus from the paper feed cassette 202 or manual feed tray 203. The printing paper thus fed is fed to the paper convey unit 204, and conveyed so as to sequentially pass through the developing units 205, 206, 207, and 208. At the same time, the image data of different colors rasterized by the printer control unit 201 are subjected to an image conversion process, and supplied to the laser scanner unit 209.
The laser scanner unit 209 is a circuit for driving a semiconductor laser, and switches ON and OFF of a laser beam emitted from the semiconductor laser in accordance with input image data. Electrostatic latent images are formed on photosensitive drums of the developing units 205, 206, 207, and 208 based on the image data of different colors supplied to the laser scanner unit 209, and the images are developed in accordance with the individual colors, thereby forming desired color images (developer images).
By synchronizing the formation of the image data of different colors with the conveyance of the printing paper, color images of different colors are transferred onto the printing paper conveyed by the paper convey unit 204. Also, a sensor for sensing the residual amount of toner is attached to each of the developing units 205, 206, 207, and 208, and each sensor supplies information to the control system of the printing section in accordance with the reduction in toner. The fixing unit 210 thermally fixes the color images thus printed on the printing paper, and discharges the printing paper to the paper discharge tray 211. In the arrangement of the printer 2 as described above, a printed image can be obtained at very high speed because each color can independently be developed.
<Arrangement of Printer Control Unit>
Details of an arrangement example of the printer control unit 201 in the above-described printer 2 will be explained below with reference to
The interface units 106, 107, and 108 are connected to external apparatuses (for example, host computers), and receive code data and compressed image data from external apparatuses 111 to 113. In accordance with the types of interfaces, the interface units 106 to 108 include independent I/F units, that is, the USB I/F unit 106, LAN I/F unit 107, and WLAN I/F unit 108.
The CPU 101 executes a control program stored in the ROM 102, and comprehensively controls the printer 2. The RAM 103 provides an area for storing printing data to be printed supplied from the host computers, and provides, as a work memory, a work area required when the CPU 101 executes various control operations. The ROM 102 stores various programs (firmware) to be executed by the CPU 101.
The interface units 106 to 108 are connected by interface cables, and exchange control signals and data with the host computers. Data reception is performed by storing image data transferred from the host computer in the RAM 103, and transferring the stored data to the engine controller 110 when printing the data. The engine controller 110 outputs the image data transferred from the RAM 103, in response to a sync signal supplied from the engine unit 105. The panel controller 109 controls information to be displayed on the panel 200, and monitors information of the switches and the like on the panel 200.
The power controller 104 manages the power source of the whole apparatus by monitoring ON/OFF of the main power switch, and controls power supply to each portion of the printer control unit 201. The printer 2 according to this embodiment is controlled to, for example, a standby state, sleep state, or power-off state, as a power control state set by the power controller 104. The standby state is a state in which the printer 2 is activated, printing is immediately executable when a print instruction or the like is received, and electric power is supplied to each device shown in
<Interface>
Next, the connection environment between the printer 2 and external apparatuses will be explained with reference to
<Power Saving Control>
The procedure of power saving control in this embodiment will be explained below with reference to
When the printer has completed printing, the CPU 101 determines in step S301 whether there is a next print instruction from an external apparatus (for example, a host computer). If there is a print instruction, the process advances to step S302, and the CPU 101 starts the next printing. When the printing is complete, the process returns to step S301.
On the other hand, if there is no printing instruction in step S301, the process advances to step S303, and the CPU 101 determines whether an elapsed time from the completion of printing has exceeded a preset time. If the elapsed time has not exceeded the preset time, the process returns to step S301, and the CPU 101 determines whether there is a print instruction. That is, in this step, the CPU 101 determines whether an elapsed time from the execution of last processing in the printer 2 has exceeded a predetermined time. A condition for clearing a counter that counts the elapsed time in step S303 includes an operation such as cartridge exchange or door open. Note that in step S301, whether the elapsed time has exceeded the preset time is determined. In the present invention, however, it is also possible to determine whether a condition for changing the power state of the image processing apparatus is satisfied. Examples of the condition for changing the power state are a predetermined time, and the remote-controlled reception of a shutoff command from an external apparatus.
If the elapsed time has exceeded the preset time in step S303, the process advances to step S304, and the CPU 101 confirms which of the USB I/F unit 106, LAN I/F unit 107, and WLAN I/F unit 108 is presently in a connected state. After that, the process advances to step S305. “An external apparatus is in a connected state” indicates a state in which the printer 2 is connected to the external apparatus so that communication is possible between them. That is, if an external apparatus is merely physically connected, the external apparatus is not necessarily in the connected state. In step S305, the CPU 101 determines whether a plurality of external apparatus are in the connected state, in accordance with the confirmation result in step S304. If a plurality of external apparatuses are in the connected state, the process advances to step S308, and the CPU 101 performs a shutdown process. The power controller 104 then automatically turns off the main power source of the apparatus itself, thereby shutting down the power source for the whole printer 2.
On the other hand, if a plurality of external apparatuses are not in the connected state, that is, if one external apparatus is in the connected state, the process advances to step S306 and the CPU 101 determines which interface is in the connected state. In addition, in accordance with the interface in the connected state, the CPU 101 determines whether it is possible to transit to a 0.5-W (Watt) sleep state (to be abbreviated as 0.5-W sleep hereinafter). In the printer 2 according to this embodiment, information indicating whether the sleep power can be set at 0.5 W or less is prestored in the ROM 102, and whether to transit to 0.5-W sleep or turn off the power source is determined based on this information. For example, necessary power when each interface is in the connected state is defined in the information. By referring to this information, the CPU 101 can calculate minimum necessary power by using information of the interface in the connected state as well. In this step, whether it is possible to transit to the 0.5-W sleep state is determined. However, the present invention is not limited to this, and it is also possible to perform determination equivalent to step S306 by confirming the types or number of interfaces. For example, it is possible to transit to the power-off state (a second power state) for a USB connection, and transit to the sleep state (a first power state) for a LAN connection. Alternatively, it is possible to transit to the power-off state (second power state) if there are two or more connections, and transit to the sleep state (first power state) if there is one or less connection. If there are two or more connections, it is also possible to make a predetermined interface communicable, and turn off the power sources of other interfaces. For example, if both the USB and LAN are in the connected state when the interface states are confirmed in step S304, it is possible to maintain the connected state of the LAN as a predetermined interface, and set the USB in the power-off state.
If only the WLAN I/F unit 108 is in the connected state in step S306, the CPU 101 determines that the electric power will exceed 0.5 W in the sleep state by referring to the information in the ROM 102. Therefore, the CPU 101 advances the process to step S308, and turns off the power source. On the other hand, if only the LAN I/F unit 107 is in the connected state, the CPU 101 determines that 0.5-W sleep is possible, and advances to step S307.
In step S307, the CPU 101 causes the power controller 104 to stop power supply to the interface units except for the LAN I/F unit 107, and simultaneously changes the LAN I/F unit 107 to minimum necessary power supply, thereby transiting to 0.5-W sleep. After that, the process advances to step S309. Also, the CPU 101 stops power supply to the engine controller 110, and stops power supply to the panel controller 109 except for a switch for resumption from sleep. In step S309, the CPU 101 maintains the sleep state until a print instruction from the LAN I/F 107 or an instruction from the resuming switch of the panel is received. When the resuming instruction is received, the process returns to step S301.
As has been explained above, the image processing apparatus according to this embodiment confirms the connected state of each interface when a predetermined time has elapsed after printing is complete (after image processing is complete), and determines whether it is possible to transit to 0.5-W sleep in which a power state of 0.5 W or less is maintained. If the transition to 0.5-W sleep is possible, the image processing apparatus executes sleep control for transiting to the sleep state. If the transition to 0.5-W sleep is impossible, the image processing apparatus turns off the power source. Consequently, the image processing apparatus according to this embodiment can execute power saving control more effectively. For example, it is possible to reduce unnecessary turning-off of the power source, thereby reducing an unnecessary power consumption and unnecessary standby time caused by reboot.
Note that in this embodiment, power saving control as explained with reference to
<Second Embodiment>
The second embodiment of the present invention will be explained below with reference to
<Power Saving Control>
The procedure of power saving control according to this embodiment will be explained below with reference to
In step S405, the CPU 101 determines whether it is possible to transit to sleep at 0.5 W or less, regardless of the number of interfaces in the connected state. More specifically, the CPU 101 refers to a management table 600 shown in
The management table 600 shown in
The priority order 603 defines information of an interface whose connected state is to be given priority, in an item for which a plurality of interfaces are in the connected state. Therefore, no information of the priority order is defined for a single interface. Referring to
Referring back to
In step S407, the CPU 101 confirms the priority order by referring to the management table 600 stored in the ROM 102. Note that the user can freely set the priority order in the management table 600. An operation when, for example, the USB and LAN are in the connected state will be explained below.
When the USB and LAN are in the connected state, the CPU 101 refers to the management table, and determines that the LAN is an interface when transiting to sleep, because the LAN is preset in the priority order 603.
In step S408, the CPU 101 confirms power consumption when sleep is set for the LAN based on the management table shown in
In step S409, the CPU 101 causes a power controller 104 to stop power supply to the interface units except for the LAN I/F unit 107, and changes the LAN I/F unit 107 to minimum necessary power supply. Note that if the process advances to step S409 from the determination in step S408, power supply to the USB I/F unit 106 in the connected state is stopped. In this embodiment as described above, even when a plurality of external apparatuses are in the connected state, power supply to a given interface in the connected state is stopped in accordance with the predetermined priority order, unlike in the above-mentioned first embodiment. In addition, power supply to an engine controller 110 is also stopped, and power supply to a panel controller 109 is stopped except for a switch for resumption from sleep. In step S411, the CPU 101 maintains the sleep state until a print instruction from the LAN I/F unit 107 or an instruction from the resuming switch of the panel is received. When the resuming instruction is received, the process returns to step S401.
As has been explained above, the image processing apparatus according to this embodiment determines, when performing power saving control, whether 0.5 W or less can be achieved from the present connected state in accordance with the management table. In addition, if 0.5 W or less cannot be achieved when a plurality of external apparatuses are in the connected state, this image processing apparatus determines whether 0.5 W or less can be achieved by stopping power supply to a given external apparatus in accordance with the priority order. Accordingly, the image processing apparatus according to this embodiment can execute power saving control more effectively. For example, it is possible to reduce unnecessary turning-off of the power source, thereby reducing an unnecessary power consumption and unnecessary standby time caused by reboot.
Other Embodiments
Aspects of the present invention can also be realized by a computer of a system or apparatus (or devices such as a CPU or MPU) that reads out and executes a program recorded on a memory device to perform the functions of the above-described embodiment(s), and by a method, the steps of which are performed by a computer of a system or apparatus by, for example, reading out and executing a program recorded on a memory device to perform the functions of the above-described embodiment(s). For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (for example, computer-readable medium).
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2012-031042 filed on Feb. 15, 2012, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-031042 | Feb 2012 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6895196 | Uchizono et al. | May 2005 | B2 |
| 7283262 | Takeda et al. | Oct 2007 | B2 |
| Number | Date | Country |
|---|---|---|
| 2008-142942 | Jun 2008 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20130209132 A1 | Aug 2013 | US |
