The present invention relates to an image forming apparatus that determines whether a specific sound is occurring when being in operation, an image forming method, and an image forming system.
Image forming apparatuses such as a copier and a laser printer include replacement components that are to be replaced due to their lifetimes. When a replacement component is used in a period exceeding its lifetime, a specific sound may be generated or the sound may change according to the state of the component. For example, in a feeding unit that feeds sheets to a conveyance path, as a result of the outer diameter and the surface property of the roller changing due to wear-out of its roller surface, a specific sound is generated. The generation of a specific sound is one of the signs indicating that a replacement component is used past its lifetime and a failure may occur; therefore, it is desired that the generation of a specific sound is determined and a replacement component that generates the specific sound is specified.
Japanese Patent Laid-Open No. 2004-226482 discloses a configuration in which a sound collector is arranged inside an image forming apparatus, and a component that generates a specific sound is detected by comparing a sound collected by the sound collector with the sound in a normal state.
Japanese Patent Laid-Open No. 2016-55933 discloses a configuration in which an ultrasonic wave is transmitted from a transmitting unit, and a receiving unit receives an ultrasonic wave that has passed through a sheet, and as a result information regarding the sheet is detected.
However, if both of the configuration in which a specific sound is detected in order to determine the state of a member, as in Japanese Patent Laid-Open No. 2004-226482, and the configuration in which information regarding a sheet is detected, as in Japanese Patent Laid-Open No. 2016-55933, are provided in an apparatus, the following problems are incurred. First, the space for accommodating both of the configurations inside the apparatus increases. Also, the number of components of the apparatus increases. Moreover, the cost of the apparatus increases.
According to an aspect of the present invention, an image forming apparatus includes: a plurality of members for forming an image; a transmitting unit configured to transmit a sonic wave; a receiving unit configured to receive a first sonic wave that has been transmitted from the transmitting unit and has passed through a sheet and a second sonic wave that is generated from at least one of the plurality of members; a detection unit configured to detect information regarding a type or state of the sheet based on the first sonic wave; and a determination unit configured to determine a state of a member that has generated the second sonic wave based on the second sonic wave.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are assigned to the same or similar configurations, and redundant description thereof is omitted.
The intermediate transfer belt 17 is extended between a driving roller 18, a tension roller 25, and a secondary transfer counter roller 20, and is rotationally driven, following the rotation of the driving roller 18, in the counterclockwise direction in the diagram when an image is formed. With this, the developer image transferred to the intermediate transfer belt 17 is conveyed to a position opposing a secondary transfer roller 19. Meanwhile, a recording material (sheet) P stored in a cassette 2 is fed to a conveyance path by a feeding roller 4. A separation roller 5 separates the recording materials P sheet by sheet when the recording materials P are fed from the cassette 2. The feeding roller 4 and the separation roller 5 constitute a feeding unit. In a period in which an unshown electromagnetic clutch is in an ON state, a rotary driving force from an unshown motor is transmitted to the feeding roller 4, and with this, the feeding roller 4 is rotationally driven. In a period in which the electromagnetic clutch is in an OFF state, transmission of the rotary driving force from the unshown motor to the feeding roller 4 is cut off. A conveyance roller pair 6 conveys the fed recording material P downstream of the conveyance path, that is, toward a position opposing the secondary transfer roller 19. The secondary transfer roller 19 outputs a secondary transfer bias, and transfers the developer image on the intermediate transfer belt 17 to the recording material P. Note that the developer that remains on the intermediate transfer belt 17 without being transferred to the recording material P is collected to a cleaning unit 36 by a cleaning blade 35. After the developer image is transferred, the recording material P is conveyed to a fixing device 21. The fixing device 21 fixes the developer image on the recording material P by heating and pressing the recording material P. After the developer image is fixed, the recording material P is discharged outside of the image forming apparatus 1 by a discharging roller pair 22. Note that the roller pairs including the conveyance roller pair 6 and the discharging roller pair 22 are configured as a roller unit.
The image forming apparatus 1 includes a transmitting unit 31 that transmits an ultrasonic wave and a receiving unit 71 that receives a sonic wave including an ultrasonic wave. Note that the transmitting unit 31 and the receiving unit 71 are respectively arranged on sides opposite to each other relative to the conveyance path of the recording material P, and the ultrasonic wave that has been transmitted from the transmitting unit 31 and has passed through the conveyance path of the recording material P is received by the receiving unit 71. For example, the transmitting unit 31 includes a piezoelectric element, which is a mutual converting element between a mechanical displacement and an electric signal. Also, the receiving unit 71 includes a MEMS (Micro Electro Mechanical System) microphone that converts the vibration displacement of a diaphragm due to pressure to a change in voltage, and outputs the voltage. Note that, if both of an ultrasonic wave and a sonic wave in an audible range are allowed to be received, a microphone, other than the MEMS microphone, such as a condenser microphone can also be used.
Returning to
The receiving unit 71 outputs a voltage corresponding to the level of the received ultrasonic wave. An amplifier unit 342 of a reception control unit 34 amplifies the voltage input from the receiving unit 71, and outputs the amplified voltage to an A/D converter unit 343. The A/D converter unit 343 converts the voltage from the amplifier unit 342 to a digital signal. A peak detection unit 344 detects a peak value (maximum value) of values of the input digital signal, and saves the detected peak value in a storage unit 346. Note that the peak detection unit 344 saves the peak values in a state in which the recording material P is not present at a detection position 200 between the transmitting unit 31 and the receiving unit 71 and in a state in which the recording material P is present at the detection position 200 in the storage unit 346. Whether the recording material P is present or not is notified from the CPU 80 via the communication unit 32. A computation unit 345 calculates an attenuation coefficient from the ratio between the peak value in a state in which the recording material P is not present and the peak value in a state in which the recording material P is present, which are saved in the storage unit 346, and stores the attenuation coefficient into the storage unit 346. The attenuation coefficient indicates a degree of attenuation of an ultrasonic wave by the recording material P, and because the degree of attenuation differs depending on the basis weight, the basis weight of the recording material P can be determined from the attenuation coefficient. The CPU 80 acquires the attenuation coefficient from the storage unit 346 via the communication unit 32, and determines the basis weight of the recording material P. Also, the CPU 80 controls the image forming condition when an image is formed on a recording material P based on the determined basis weight of the recording material P. The image forming condition to be controlled includes a conveyance speed of the recording material P, a secondary transfer bias, a fixing temperature of the fixing device 21, and the like.
A filtering computation unit 735 performs filtering processing by applying a filter in order to extract a frequency component suitable for determining a specific sound (hereinafter, referred to as an “abnormal sound”) from the digital signal from which a DC component has been removed by the reference A/D value setting unit 734. Note that the filtering computation unit 735 has a plurality of filters that are to be applied to a plurality of abnormal sounds to be determined, and performs filtering processing using the filter notified by the CPU 80. A square computation unit 736 performs a square computation on the digital signal subjected to the filtering processing, and a section average computation unit 737 performs a section average computation on the digital signal subjected to the square computation. For example, the time period for which a section average computation is performed is 100 ms. The time length for which the section average computation is performed may be the same regardless of the abnormal sound to be determined, or different in accordance with the abnormal sound to be determined. As a result of performing the square computation and the section average computation, the magnitude of a sound can be easily compared when an abnormal sound is determined. The section-averaged signal is stored in a storage unit 738 as a signal level L of the received sound. The CPU 80 acquires the signal level L from the storage unit 738 via the communication unit 74, and determines whether or not an abnormal sound is occurring. The CPU 80, upon determining that an abnormal sound is occurring, performs processing in accordance with the determined abnormal sound.
Also, the abnormal sounds shown in
Also, the determination information also indicates a filter to be used by the filtering computation unit 735 in order to determine the abnormal sound of a determination target. In the example in
In step S12, the CPU 80 determines whether or not the signal level L is anomalous based on the criterion shown in
If it is determined that the signal level L is anomalous in step S12, the CPU 80 determines whether a counter N is a threshold value Nth or more in step S13. The threshold value Nth is shown in the “number of determinations” in
On the other hand, if it is determined that the signal level L is not anomalous in step S12, the CPU 80 determines, in step S17, whether the counter M is a threshold value Mth or more. The threshold value Mth is shown in the “number of releases” in
In step S19, the CPU 80 determines whether the image formation has ended, and if the image formation has not ended, repeats the processing from step S10. On the other hand, if the image formation has ended, the CPU 80 ends the processing in
Note that, a configuration may be adopted in which the CPU 80 normally selects the abnormal sound to be determined successively from the table in
The feeding unit abnormal sound occurs because the surfaces of the feeding roller 4 and the separation roller 5 are worn away due to the feeding of the recording materials P. When a recording material P is drawn out by the downstream conveyance roller pair 6 in a state in which the electromagnetic clutch is turned off and the rotational driving of the feeding roller 4 is stopped, a vibration may occur in the separation roller 5 that rotates due to drawing out of the recording material P. This vibration causes vibration in the separation roller 5 and the recording material P, and as a result, an abnormal sound is generated. Therefore, the generation of the feeding unit abnormal sound is determined based on the sound received by the receiving unit 71 in a period in which the electromagnetic clutch is in an OFF state, and a recording material P is being drawn out from the feeding unit by the conveyance roller pair 6. The arrows A in
As described above, the states of members of the image forming apparatus 1 are determined by utilizing the receiving unit 71 that is used to detect the basis weight of a recording material P. Specifically, it is determined whether or not a member is generating an abnormal sound while being in operation. As a result of determining an abnormal sound using the receiving unit 71 for basis weight detection that is generally provided in an image forming apparatus, the number of components to be added for determining an abnormal sound can be reduced, and the cost of the image forming apparatus 1 can be reduced. Also, the size of the image forming apparatus 1 can be reduced.
Note that, in
Also, in the present embodiment, the CPU 80 selects the determination target abnormal sound. However, the configuration may be such that, instead of setting a specific abnormal sound as the determination target, the receiving unit 71 continuously collects sounds, and the CPU 80 determines the occurrences of the abnormal sounds and the positions at which the abnormal sounds are occurring by performing computations in accordance with the respective determination target abnormal sounds on the receiving result of the receiving unit 71. Moreover, in the present embodiment, an abnormal sound is detected by utilizing the receiving unit 71 that is used to detect the basis weight, which is a parameter for specifying the type of a recording material P. However, a configuration may also be adopted in which an abnormal sound is detected by utilizing a receiving unit 71 that is used to detect another parameter for specifying the type of a recording material P, e.g., the thickness. More generally, the configuration may be such that an abnormal sound is detected by utilizing a receiving unit 71 that receives sounds for detecting the type of a recording material P.
Also, the threshold values for the respective determination target abnormal sounds can be determined in advance. Moreover, the configuration can also be such that the receiving unit 71 is caused to receive sonic waves in an initial stage of the operation of the image forming apparatus, and the threshold values are determined based on the received result.
Next, a second embodiment will be described focusing on the difference from the first embodiment. If a driving unit including motors for driving rollers is used over its lifetime in an image forming apparatus, a problem may occur such as an image failure due to grinding of gears, depletion of grease, or the like in the driving unit. In this case, the driving unit needs to be replaced. In the present embodiment, the driving unit that is used over its lifetime is determined by a sonic wave occurring in the driving unit.
When grinding of gears, depletion of grease, or the like occurs in the driving unit, the sound from the driving unit gradually increases such that a user does not feel the sound as an uncomfortable abnormal sound. In the present embodiment, the number of recording materials P on which images are formed is stored in an unshown storage unit in the control unit 3. If the number of recording materials P stored in the storage unit reaches a predetermined number, e.g., 10000, the control unit 3 independently drives each driving unit. In this example, the image forming apparatus is assumed to include a feeding driving unit for driving the feeding roller 4 and the like, an image forming driving unit for driving an image formation unit, and a fixing driving unit that drives the fixing device 21 and the like. Note that the image formation unit includes at least one of the photoconductive member 11, the charging roller 12, the developing device 14, the intermediate transfer belt 17, and the cleaning unit 36. In this case, the control unit 3 successively drives the feeding driving unit, the image forming driving unit, and the fixing driving unit. That is, the control unit 3 performs control such that two or more of the driving units of the three driving units are not driven at the same time. Then, the abnormal sound determination control unit 70 stores the signal level L of a received sound that is created based on sonic waves received by the receiving unit 71 in a state in which only one driving unit is being driven, similarly to the first embodiment.
As described above, the states of the members of the image forming apparatus 1 are determined utilizing the receiving unit 71 that is used to detect the basis weight of a recording material P. Specifically, it is determined whether or not a member has reached a predetermined lifetime. With this, similarly to the first embodiment, the number of components to be added for determining the states of the members can be reduced, and the cost of the image forming apparatus 1 can be reduced. Also, the size of the image forming apparatus 1 can be reduced.
Next, a third embodiment will be described focusing on the difference from the first embodiment. As described above, when a recording material P is fed to the conveyance path, the recording materials P are separated sheet by sheet by the separation roller 5. However, so-called double feed, which is a phenomenon in which the separation roller 5 does not function and a plurality of recording materials P are fed in an overlaid state, may occur when sheets are conveyed. Therefore, the image forming apparatus 1 is provided with a function of detecting the double feed. In the present embodiment, the occurrence of an abnormal sound is determined utilizing a receiving unit used for detecting this double feed.
The receiving unit 71 outputs a voltage corresponding to the level of the ultrasonic wave received through a recording material P. An amplifier unit 442 of a reception control unit 44 amplifies a voltage input from the receiving unit 71, and outputs the amplified voltage to an A/D converter unit 443. The A/D converter unit 443 converts the voltage from the amplifier unit 442 to a digital signal, and outputs the digital signal to a peak detection unit 444. The peak detection unit 444 detects a peak value (maximum value) of values of the input digital signal, and saves the detected peak value in a storage unit 446. The CPU 80 acquires a peak value from the storage unit 446 via the communication unit 32, and compares the peak value with a reference peak value. The reference peak value is a peak value when there is one recording material P, and is measured and stored in the control unit 3 in advance. When the double feed is not occurring, the difference between the peak value acquired from the storage unit 446 and the reference peak value is small. On the other hand, if the double feed is occurring, the level of ultrasonic wave received by the receiving unit 71 decreases. Therefore, when the double feed is occurring, the difference between the peak value acquired from the storage unit 446 and the reference peak value is large. Therefore, the CPU 80 can determine whether or not the double feed is occurring based on whether or not the difference between the peak value acquired from the storage unit 446 and the reference peak value is larger than a threshold value.
Note that the method of determining a specific sound utilizing the receiving unit 71 is similar to those of the first and second embodiments, and therefore the description thereof will be omitted.
As described above, as a result of determining the states of the members utilizing the receiving unit 71 that is used to detect the double feed, which is a state of the recording materials P, the number of components can be reduced, and the reduction in size of the image forming apparatus can be realized. As a result, the cost of the image forming apparatus 1 can be reduced.
In the first embodiment, the basis weight detection control unit 30 is provided with the amplifier unit 342 and the A/D converter unit 343, and the abnormal sound determination control unit 70 is provided with the amplifier unit 732 and the A/D converter unit 733. In the present embodiment, an amplifier unit and an A/D converter unit are shared between the control units.
When the basis weight is detected, the CPU 80 instructs the basis weight detection control unit 37 to transmit an ultrasonic wave. With this, the basis weight detection control unit 37 outputs a driving signal. The amplifier unit 852 amplifies the driving signal, and outputs the amplified driving signal to the transmitting unit 31. Note that the amplification factor of the amplifier unit 852 is set by the CPU 80. Also, when the basis weight is detected, the CPU 80 sets a preset first amplification factor suitable for detecting the basis weight to the amplifier unit 842. The A/D converter unit 843 digitally converts the voltage from the amplifier unit 842 that has been amplified with the first amplification factor, and outputs the digitally converted voltage to the basis weight detection control unit 37. The processing in the basis weight detection control unit 37 thereafter is similar to that in the first embodiment.
When an abnormal sound is determined, the CPU 80 sets a preset second amplification factor suitable for determining the abnormal sound to the amplifier unit 842. Note that, because the level of the abnormal sound is larger than that of the ultrasonic wave, the second amplification factor is smaller than the first amplification factor. The A/D converter unit 843 digitally converts the voltage from the amplifier unit 842 that has been amplified with the second amplification factor, and outputs the digitally converted voltage to the abnormal sound determination control unit 75. The processing in the abnormal sound determination control unit 75 thereafter is similar to that in the first embodiment. Note that a configuration can be adopted in which the digital signal from the A/D converter unit 843 is constantly output to both of the basis weight detection control unit 37 and the abnormal sound determination control unit 75. Also, the configuration can be such that the digital signal from the A/D converter unit 843 is output to only one of the basis weight detection control unit 37 and the abnormal sound determination control unit 75 in accordance with whether the basis weight detection is to be performed or the determination of an abnormal sound is to be performed.
In step S28, the CPU 80 determines the basis weight of the recording material P based on the ratio of the peak value in a state in which the recording material P is not present at the detection position 200 and the peak value in a state in which the recording material P is present at the detection position 200. In step S29, the CPU 80 sets the image forming condition based on the determined basis weight. Thereafter, the CPU 80 sets, in step S30, the second amplification factor for abnormal sound determination to the amplifier unit 842, and performs, in step S31, determination of the abnormal sound by causing the abnormal sound determination control unit 75 to acquire the signal level L. In step S32, the CPU 80 determines whether the image formation has ended, that is, whether images have been formed on all the recording materials P in this image formation. Upon determining that the image formation has ended, the CPU 80 ends the processing in
As described above, in the present embodiment, as a result of the amplifier unit and the A/D converter unit being used in common between the basis weight detection and the determination of a specific sound, the number of components can be reduced relative to the configurations of the first and second embodiments. Therefore, the cost of the image forming apparatus can further be reduced. Note that the amplifier unit and the A/D converter unit can also be used in common between the double feed detection and the determination of a specific sound. With this, the number of components can be reduced relative to the configuration of the third embodiment, and the cost can be reduced. Note that a configuration may be adopted in which only the amplifier unit is used in common, and the A/D converter unit is not used in common.
The first embodiment and the third embodiment can also be combined. That is, a configuration may be adopted in which the receiving unit is shared between the basis weight detection and the double feed detection, and the basis weight, the double feed, and the specific sound are detected using one receiving unit. Also, the present invention can also be realized as a sheet conveyance apparatus that conveys sheets such as recording materials P. The sheet conveyance apparatus has a function of detecting the basis weight of a recording material P to be conveyed and/or a function of detecting the double feed. Also, the sheet conveyance apparatus performs determination of a specific sound using the receiving unit for detecting the basis weight of a recording material P and the double feed. Also, the sonic wave to be transmitted from the transmitting unit 31 may include components in an audible band.
Also, each of the amplifier units in the first to fourth embodiments may have a plurality of amplification factors. For example, the configuration may be such that when a sound having a high sound pressure is to be detected, a low amplification factor is selected, and when a sound having a low sound pressure is to be detected, a high amplification factor is selected. With this, appropriate amplification factors can be set to the amplifier units 732 and 842 in accordance with the member whose state is to be determined, specifically, the specific sound to be determined.
Also, some of the functions of the abnormal sound determination control unit 70, e.g., the functional blocks after the reference A/D value setting unit 734, can be provided in a processing system (processing apparatus) outside the image forming apparatus. That is, the present invention can be realized as an image forming system including the image forming apparatus 1 and a processing system that are connected via a network. In this case, the image forming apparatus 1 transmits information indicating the sound received by the receiving unit 71, e.g., a digital value, to the processing system via the network. Also, the processing system determines the signal level L based on the information received from the image forming apparatus 1, and determines the state of a member of the image forming apparatus 1, specifically, whether or not the member generates a specific sound based on the signal level L. Note that the specific sound is a sound generated when the member has failed or a sound generated when the member has reached a predetermined lifetime, for example. Therefore, in this case, the processing for determining the state of a member that is to be executed by the control unit 3 (or CPU 80) in the embodiments described above is to be performed by the processing system. Upon determining the member that generates a specific sound, the processing system notifies the image forming apparatus 1 or a service center of this fact. With this, the image forming apparatus 1 performs processing in accordance with the determined member and processing for notifying the user.
The processing system or processing apparatus outside the image forming apparatus can perform higher level processing than the image forming apparatus itself, e.g., fast Fourier transform and the like, and therefore can detect a specific sound at a higher accuracy. Also, the abnormal sound determination control unit 70 can also be realized by a circuit that realizes a specific function (e.g., ASIC). Also, when a processing system or a processing apparatus is provided outside the image forming apparatus, the processing in the processing system or the processing apparatus can be realized by a computer program. That is, the above-described processing for determining whether or not the specific sound is occurring in a member can be realized by one or more processors reading out and executing a program.
The present invention is not limited to the above embodiments, and various changes and modifications can be made within the spirit and scope of the invention. Therefore, claims have been made to apprise the public of the scope of the present invention.
Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiments and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiments, and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiments and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiments. The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.
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. 2019-058899, filed on Mar. 26, 2019, which is hereby incorporated by reference herein in its entirety.
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