Image forming apparatus

Abstract

To provide an image forming apparatus low in cost and excellent in convenience and power-saving capability.SOLUTION: When an image forming apparatus 1 is in a normal mode and, in this state, a controller 10 accepts through an operation device 16 an instruction to transition to a power-saving mode, the controller 10 causes the image forming apparatus 1 to transition from the normal mode to the power-saving mode. Then, the controller 10 counts the number of times that a detection device 21 has detected a person within a first period from the time of acceptance of the instruction to transition, and when the counted number of times reaches a specified number, the controller 10 causes the image forming apparatus 1 to return from the power-saving mode to the normal mode. When the counted number of times falls short of the specified number, the controller 10 keeps the image forming apparatus 1 in the power-saving mode.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an image forming apparatus, and more particularly to a technique for determining the timing of returning from a power saving mode to a normal mode.

Background Art

[0002] There is known an image forming apparatus that returns from a power saving mode to a normal mode when a human sensor detects a person. In such an image forming apparatus, after the image forming apparatus shifts to the power saving mode by the user pressing the power saving key, when the user who pressed the power saving key leaves the image forming apparatus, the human sensor may detect the user. In this case, although it is immediately after shifting to the power saving mode based on the pressing of the power saving key by the user, the image forming apparatus unnecessarily returns to the normal mode.

[0003] In order to solve such a problem, Patent Document 1 discloses a technique of restricting the return to the normal mode based on the detection of the human sensor until the first detection by the human sensor becomes non-detection when shifting to the power saving mode by pressing the power saving key. Also, a technique of making a return determination to the normal mode using a high-performance human sensor capable of detecting the approach and separation of a user to and from the image forming apparatus can be proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the technology disclosed in Patent Document 1, when the user who presses the power-saving key does not leave the image forming apparatus for a long time, the return to the normal mode is restricted until the user leaves the image forming apparatus. Therefore, there is a risk that the convenience of another user who wants to use the image forming apparatus may be impaired. In addition, when providing the above-described high-performance human sensor, there is a problem that the cost increases.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming apparatus that is low-cost and excellent in convenience and power saving performance.

Means for Solving the Problems

[0007] An image forming apparatus according to an aspect of the present invention includes an image forming unit that forms an image on a recording sheet, an operation unit into which a user's instruction is input, a detection unit that detects a person existing within a predetermined range, and when the image forming apparatus is in a predetermined first power state, upon receiving an instruction to shift to a second power state having less power consumption than the first power state via the operation unit, a control unit that causes the image forming apparatus to shift from the first power state to the second power state. The control unit counts the number of times the detection unit detects a person within a predetermined first period from the time when the shift instruction is received, and when the counted number reaches at least a predetermined number of times or more, causes the image forming apparatus to return from the second power state to the first power state, and when the counted number has not reached the predetermined number of times, maintains the image forming apparatus in the second power state.

Effects of the Invention

[0008] According to the present invention, it is possible to prevent the image forming apparatus from unnecessarily returning to the normal mode within a predetermined period from the time when the shift instruction is received without using a high-performance sensor. In addition, after the elapse of a predetermined period, since the return determination based on the counted number is not performed, even when the user who has pressed the power-saving key has not left the image forming apparatus, another user can use the image forming apparatus. Therefore, it is possible to provide an image forming apparatus that is low-cost and excellent in convenience and power saving performance.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front cross-sectional view showing the structure of an image forming apparatus 1 according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the image forming apparatus 1.

[0011] [Device Configuration] Referring to FIG. 1, the image forming apparatus 1 is a multifunction device having a plurality of functions such as a copying function, a transmitting function, a printer function, and a facsimile function. The housing of the image forming apparatus 1 houses an image reading unit 11, an image forming unit 12, a fixing unit 13, a paper feeding unit 14, and the like.

[0012] The image reading unit 11 is an ADF (Auto Document Feeder) including a document conveying unit 6 that conveys a document placed on the document table, and a scanner that optically reads the document conveyed by the document conveying unit 6 or a document placed on the platen glass 7. The image reading unit 11 irradiates the document with a light irradiation unit and receives the reflected light with a CCD (Charge-Coupled Device) sensor to read the image of the document and generate image data.

[0013] The image forming unit 12 includes a photoreceptor drum, a charging device, an exposure device, a developing device, and a transfer device. Based on the image data generated by the image reading unit 11 or the image data etc. input via the communication unit 23, the image forming unit 12 forms an image constituted by a toner image on the recording paper P conveyed along the conveyance path T by the conveyance unit 17.

[0014] The fixing unit 13 heats and presses the recording paper P on which the toner image is formed by the image forming unit 12 to fix the toner image on the recording paper P. The recording paper P on which the toner image is fixed is discharged to the discharge tray 8.

[0015] The paper feeding unit 14 includes a manual feed tray and a plurality of paper feed cassettes. The paper feeding unit 14 pulls out the recording paper P accommodated in any one of the plurality of paper feed cassettes or the recording paper placed on the manual feed tray one by one by a pickup roller and feeds it to the conveyance path T.

[0016] Referring to FIG. 2, the image forming apparatus 1 includes a control unit 100. The control unit 100 includes a processor, a RAM (Random Access Memory), and a ROM (Read Only Memory). The processor is, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or an ASIC (Application Specific Integrated Circuit).

[0017] The control unit 100 is electrically connected to the original document conveyance unit 6, the image reading unit 11, the image forming unit 12, the fixing unit 13, the paper feeding unit 14, the display unit 15, the operation unit 16, the conveyance unit 17, the HDD (Hard Disk Drive) 18, the image processing unit 19, the image memory 20, the detection unit 21, the facsimile communication unit 22, and the communication unit 23 etc.

[0018] The control unit 100 functions as the control unit 10 when various computer programs stored in the built-in ROM or HDD 18 are executed by the above-mentioned processor. The control unit 10 performs overall control of the image forming apparatus 1. More specifically, the control unit 10 controls the operations of each part of the image forming apparatus 1 and the communication with external devices such as a PC (Personal Computer) 24 connected via a network.

[0019] Note that the control unit 10 may be configured to be operable by a logic circuit without depending on the operations based on the computer program, or may be configured to be realized by two or more control units.

[0020] The display unit 15 is a display device constituted by a liquid crystal display or an organic EL (Organic Light-Emitting Diode) display. The display unit 15 displays various screens regarding each function executable by the image forming apparatus 1.

[0021] The operation unit 16 includes a plurality of hard keys including a power saving key 16A for inputting an instruction to shift from the normal mode to the power saving mode. The operation unit 16 includes a touch panel 16B disposed overlapping the display unit 15. User instructions regarding each function executable by the image forming apparatus 1 are input to the operation unit 16.

[0022] The conveyance unit 17 includes a pair of conveyance rollers 17A and a pair of discharge rollers 17B, and a conveyance motor connected to the pair of conveyance rollers 17A and the pair of discharge rollers 17B. The control unit 10 drives the conveyance motor to rotate the pair of conveyance rollers 17A and the pair of discharge rollers 17B, thereby conveying the recording paper P fed by the paper feeding unit 14 along the conveyance path T toward the image forming unit 12 and the discharge tray 8.

[0023] The HDD 18 stores the image data generated by the image reading unit 11 and various data including various computer programs for realizing the operations of the image forming apparatus 1. In the present embodiment, the HDD 18 stores a return determination program for executing a return determination process described later.

[0024] The image processing unit 19 executes image processing on the image data generated by the image reading unit 11 as necessary. The image memory 20 includes an area for temporarily storing the image data generated by the image reading unit 11.

[0025] The detection unit 21 is provided on the front side of the image forming apparatus 1. The detection unit 21 is a human presence sensor that detects a person existing within a predetermined range near the image forming apparatus 1. The detection unit 21 is not particularly limited as long as it is generally used, and for example, an infrared sensor can be used.

[0026] The facsimile communication unit 22 connects to a public line and transmits and receives image data via the public line. The communication unit 23 includes a communication module such as a LAN (Local Area Network) board. The control unit 10 performs data communication with an external device such as a PC 24 connected via a network via the communication unit 23.

[0027] Power is connected to each part of the image forming apparatus 1. When the power is turned on by the user, power is supplied from the power source to each part of the image forming apparatus 1.

[0028] The control unit 10 operates the image forming apparatus 1 in either a normal mode or a power saving mode. In the normal mode, the image forming apparatus 1 operates in a predetermined first power state. The first power state indicates a state in which power is sufficiently supplied to each part of the image forming apparatus 1 so that various functions of the image forming apparatus 1 can be immediately executed.

[0029] In the power saving mode, the image forming apparatus 1 operates in a second power state with less power consumption than the first power state. The second power state indicates a state in which the power supply to each part of the image forming apparatus 1 is reduced or cut off, and only the minimum power necessary to operate the image forming apparatus 1 is supplied to each part of the image forming apparatus 1. In the power saving mode, for example, the fixing roller of the fixing unit 13 is maintained at a low temperature, and the screen of the display unit 15 is turned off.

[0030] In the present embodiment, when the control unit 10 operates according to the above-described return determination program and receives an instruction to shift to the power saving mode via the operation unit 16 when the image forming apparatus 1 is in the normal mode, the control unit 10 shifts the image forming apparatus 1 from the normal mode to the power saving mode, counts the number of times the detection unit 21 detects a person within a predetermined first period from the time the shift instruction is received, and when the counted number reaches a specified number, returns the image forming apparatus 1 from the power saving mode to the normal mode. When the counted number has not reached the specified number, a return determination process for maintaining the image forming apparatus 1 in the power saving mode is executed.

[0031] [Operation] Hereinafter, with reference to FIGS. 3 to 5 and the like, the operation of the image forming apparatus 1 when the return determination process is executed will be described. FIG. 3 is a flowchart showing the return determination process. FIG. 4 is a diagram showing the operation of the image forming apparatus 1 when the number of times a person is detected within the first period reaches a specified number. FIG. 5 is a diagram showing the operation of the image forming apparatus 1 when the number of times a person is detected within the first period does not reach a specified number.

[0032] When the user turns on the power of the image forming apparatus 1, the control unit 10 starts the image forming apparatus 1 and operates it in the normal mode, and starts the return determination program stored in the HDD 18 to start the execution of the return determination process shown in FIG. 3. When starting the execution of the return determination process, the control unit 10 initializes the value of the variable N indicated by the detection count counter for counting the number of times a person is detected by the detection unit 21 to "0" (step S10).

[0033] After the process of step S10, the control unit 10 determines whether or not a predetermined second period has elapsed without the operation unit 16 receiving an instruction (step S11). Here, the control unit 10 sets the second period to a predetermined default period (for example, 5 minutes). Note that the control unit 10 may set the second period according to an instruction indicating a period received from an administrator or a user via the operation unit 16.

[0034] In this case, the control unit 10 determines that the second period has not elapsed (NO in step S11), and determines whether or not an instruction to shift to the power saving mode has been received (step S12). In this case, the control unit 10 determines that no shift instruction has been received (NO in step S12), and returns to the process of step S11.

[0035] (1) When the power saving key 16A is pressed When the user presses the power saving key 16A of the operation unit 16 while the image forming apparatus 1 is in the normal mode, the control unit 10 determines that an instruction to shift to the power saving mode has been received (YES in step S12), and starts counting from the time when the shift instruction was received using a general timekeeping function (step S13). After the process of step S13, the control unit 10 shifts the image forming apparatus 1 from the normal mode to the power saving mode as shown in FIGS. 4 and 5 (step S14).

[0036] After the process of step S14, the control unit 10 determines whether or not a predetermined first time T1 has elapsed from the time when the shift instruction was received (step S15). Here, the control unit 10 sets the first period T1 to a predetermined default period (in this case, 10 seconds). Note that the control unit 10 may set the first period T1 according to an instruction indicating a period received from an administrator or a user via the operation unit 16.

[0037] (1-1) When the number of human detections reaches a specified number within the first period T1 When the control unit 10 determines that the first time T1 has not elapsed (NO in step S15), the detection unit 21 determines whether a person exists within a predetermined range near the image forming apparatus 1 (step S16). In this case, when the control unit 10 determines that the detection unit 21 has not detected a person (NO in step S16), the process returns to the process of step S15.

[0038] Here, before the first time T1 elapses, assume that the user who pressed the power saving key 16A has left the image forming apparatus 1 and the detection unit 21 has detected the user. The control unit 10 determines that the first time T1 has not elapsed (NO in step S15), and as shown in FIGS. 4 and 5, determines that the detection unit 21 has detected a person (YES in step S16), and adds 1 to the value of the variable N indicated by the detection count counter (step S17).

[0039] After the process of step S17, the control unit 10 determines whether the value of the variable N has reached a predetermined specified number of times (step S18). Here, the control unit 10 sets the specified number of times to a predetermined default number of times (in this case, 2 times). Note that the control unit 10 may set the specified number of times according to an instruction indicating the number of times received via the operation unit 16 from an administrator or a user.

[0040] In this case, since the value of the variable N is "1", the control unit 10 determines that the value of the variable N has not reached the predetermined specified number of times (NO in step S18), maintains the image forming apparatus 1 in the power saving mode, and returns to the process of step S15.

[0041] Here, before the first time T1 elapses, assume that a user different from the user who pressed the power saving key 16A approaches the image forming apparatus 1 to use the image forming apparatus 1, and the detection unit 21 has detected the different user. The control unit 10 determines that the first time T1 has not elapsed (NO in step S15), and as shown in FIG. 4, determines that the detection unit 21 has detected a person (YES in step S16), and adds 1 to the value of the variable N indicated by the detection count counter (step S17).

[0042] In this case, since the value of the variable N becomes "2", the control unit 10 determines that the value of the variable N has reached a predetermined number of times (YES in step S18), and causes the image forming apparatus 1 to return from the power saving mode to the normal mode as shown in FIG. 4 (step S19). After the process of step S19, the control unit 10 returns to the process of step S10.

[0043] (1-2) When the number of detections does not reach the specified number within the first period T1 Here, as described above, after the detection unit 21 detects the user who has pressed the power saving key 16A when the user has left the image forming apparatus 1, it is assumed that the first time T1 has elapsed without the detection unit 21 detecting a person any further.

[0044] In this case, the control unit 10 determines that the first time T1 has elapsed (YES in step S15), and determines whether the detection unit 21 has detected a person (step S20). In this case, the control unit 10 determines that the detection unit 21 has not detected a person (NO in step S20), and repeats the process of step S20.

[0045] Here, it is assumed that a user different from the user who has pressed the power saving key 16A approaches the image forming apparatus 1 to use the image forming apparatus 1, and the detection unit 21 detects the different user. The control unit 10 determines that the detection unit 21 has detected a person (YES in step S20), and causes the image forming apparatus 1 to return from the power saving mode to the normal mode as shown in FIG. 5 (step S19). After the process of step S19, the control unit 10 returns to the process of step S10.

[0046] (2) When the second period has elapsed without the operation unit 16 receiving an instruction Here, when the image forming apparatus 1 is in the normal mode, assume that the second period has elapsed without the operation unit 16 receiving an instruction. The control unit 10 determines that the second period has elapsed (YES in step S11), and determines whether the detection unit 21 has detected a person (step S20). In this case, the control unit 10 determines that the detection unit 21 has not detected a person (NO in step S20), and repeats the process of step S20.

[0047] Here, for example, assume that a user different from the user who has turned on the power approaches the image forming apparatus 1 to use the image forming apparatus 1, and the detection unit 21 has detected the other user. The control unit 10 determines that the detection unit 21 has detected a person (YES in step S20), and causes the image forming apparatus 1 to return from the power saving mode to the normal mode (step S19). After the process of step S19, the control unit 10 returns to the process of step S10.

[0048] According to the above embodiment, when the image forming apparatus 1 is in the normal mode, when the control unit 10 receives an instruction to shift to the power saving mode via the operation unit 16, the control unit 10 causes the image forming apparatus 1 to shift from the normal mode to the power saving mode. The control unit 10 counts the number of times the detection unit 21 has detected a person within the first period from the time when the shift instruction is received, and when the counted number reaches a specified number, causes the image forming apparatus 1 to return from the power saving mode to the normal mode. When the counted number has not reached the specified number, the control unit 10 maintains the image forming apparatus 1 in the power saving mode.

[0049] Thereby, without using a high-performance sensor, it is possible to prevent the image forming apparatus from unnecessarily returning to the normal mode within the first period from the time when the shift instruction is received. Also, after the elapse of the first period, since a return determination based on the counted number is not performed, even when the user who has pressed the power saving key has not left the image forming apparatus, another user can use the image forming apparatus. Therefore, it is possible to provide an image forming apparatus that is low-cost, and excellent in convenience and power saving performance.

[0050] According to the above embodiment, the control unit 10 sets the first period to a predetermined default period. Alternatively, the control unit 10 sets the first period according to an instruction indicating the period received via the operation unit 16.

[0051] Thereby, the first period is set to an appropriate period without the administrator or user inputting an instruction, or the administrator or user can set the first period to a desired period. Therefore, the convenience for the user is further improved.

[0052] According to the above embodiment, after the first period has elapsed since the control unit 10 received the transition instruction, when the detection unit 21 first detects a person, the control unit 10 returns the image forming apparatus 1 from the power saving mode to the normal mode.

[0053] Thereby, after the elapse of the first period, even if the user who pressed the power saving key has not left the image forming apparatus, another user can surely use the image forming apparatus. Therefore, the convenience for the user is further improved.

[0054] According to the above embodiment, the control unit 10 sets the specified number of times to a predetermined default number of times. Alternatively, the control unit 10 sets the specified number of times according to an instruction indicating the number of times received via the operation unit 16.

[0055] Thereby, the specified number of times is set to an appropriate number of times without the administrator or user inputting an instruction, or the administrator or user can set the specified number of times to a desired number of times. Therefore, the convenience for the user is further improved.

[0056] According to the above embodiment, when the image forming apparatus 1 is in the normal mode, when the second period elapses without the operation unit 16 receiving an instruction, the control unit 10 shifts the image forming apparatus 1 from the normal mode to the power saving mode. After the control unit 10 performs the transition to the power saving mode as the second period elapses, when the detection unit 21 first detects a person, the control unit 10 returns the image forming apparatus 1 from the power saving mode to the normal mode.

[0057] Thus, when there is no possibility that the detection unit 21 detects a user who has pressed the power saving key 16A, the return to the normal mode is performed when the detection unit 21 first detects a person without waiting for the number of person detections to reach the specified number. Therefore, when the shift to the power saving mode is performed as the second period elapses, the return to the normal mode is performed at a more appropriate timing.

[0058] (Other Modifications) In the above embodiment, the control unit 10 sets the first period T1 to 10 seconds, but the present invention is not limited to such an embodiment. The first period T1 is not particularly limited as long as it is a period normally required until the user who has pressed the power saving key 16A leaves from a predetermined range near the image forming apparatus 1. For example, the control unit 10 may set 5 seconds, 30 seconds, or the like as the first period T1.

[0059] Also, in the above embodiment, the control unit 10 sets the specified number to 2, but the present invention is not limited to such an embodiment. The specified number is not particularly limited as long as it is at least 2 or more. For example, the control unit 10 may set 3, 4, or the like as the specified number.

[0060] Also, in the above embodiment, the image forming unit 12 or the like forms an image on the recording paper P, but the present invention is not limited to such an embodiment. The image forming unit 12 or the like may form an image not only on the recording paper but also on other recording media. Examples of other recording media include, for example, OHP (Overhead Projector) sheets.

[0061] Note that the present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the above embodiment, a color multifunction machine is used as the image forming apparatus, but this is merely an example, and other image forming apparatuses such as a monochrome multifunction machine, a copying machine, or a facsimile apparatus may be used.

[0062] The configuration and processing of the above-described embodiment shown using FIGS. 1 to 5 are merely one embodiment of the present invention, and are not intended to limit the present invention to such configuration and processing.

Explanation of Reference Numerals

[0063] 1 Image forming apparatus 10 Control unit 12 Image forming unit 16 Operation unit 21 Detection unit

Claims

1. An image forming unit that forms an image on a recording paper; An operation unit to which a user's instruction is input; A detection unit that detects a person existing within a predetermined range; When the image forming apparatus is in a predetermined first power state, and a transition instruction to a second power state with less power consumption than the first power state is received via the operation unit, a control unit that causes the image forming apparatus to transition from the first power state to the second power state, and The control unit counts the number of times the detection unit has detected the person within a predetermined first period from the time the transition instruction is received, and when the counted number reaches at least a predetermined number of times or more, causes the image forming apparatus to return from the second power state to the first power state, and when the counted number has not reached the predetermined number of times, maintains the image forming apparatus in the second power state. An image forming apparatus.

2. The control unit sets the first period to a predetermined default period, or sets the first period according to an instruction indicating a period received via the operation unit. The image forming apparatus according to claim 1.

3. After the first period has elapsed from the time the transition instruction is received, the control unit causes the image forming apparatus to return from the second power state to the first power state when the detection unit first detects the person. The image forming apparatus according to claim 1.

4. The control unit sets the predetermined number of times to a predetermined default number of times, or sets the predetermined number of times according to an instruction indicating a number of times received via the operation unit. The image forming apparatus according to claim 1.

5. The control unit When a predetermined second period elapses without the operation unit receiving the instruction when the image forming apparatus is in the first power state, the image forming apparatus is shifted from the first power state to the second power state. After the transition to the second power state is performed as the second period elapses, when the detection unit first detects the person, the image forming apparatus is restored from the second power state to the first power state. The image forming apparatus according to claim 1.

Images