Patent Application
20210302893
Embodiments described herein relate generally to an image forming apparatus, an image forming method, and a non-transitory recording medium.
When a sheet is enmeshed into a transfer belt in an image forming apparatus, there is concern of the sheet not being transported along an appropriate transport path. Accordingly, an image forming apparatus includes a sensor that detects whether a sheet is transported along an appropriate transport path in some cases. The image forming apparatus stops forming an image when the sensor does not normally operate. This is because a sheet invades into an inappropriate transport path and is likely to be moved up to a position at which a user may not extract the sheet. Through such control, it is possible to prevent the sheet from being moved up to the position at which the user may not extract the sheet. However, when the sensor does not operate normally, a sensor error occurs. Therefore, there is the problem that the user may not form an image.
An exemplary embodiment provides an image forming apparatus including a transport member or conveyor, a driving unit or actuator, an image forming unit or printing assembly, a detection unit or sheet detection sensor(s), and a control unit or controller. The transport member transports a sheet. The driving unit drives the transport member. The image forming unit forms an image on the sheet. The detection unit outputs a detection signal indicating whether the sheet transported by the transport member passes through a predetermined detection position. The control unit controls an operation of the driving unit according to a length in a transport direction of the sheet which is a target on which an image is formed by the image forming unit when the detection unit does not perform a normal operation.
Hereinafter, an image forming apparatus and an image forming method according to an embodiment will be described with reference to the drawings.
An example of a hardware configuration of the image forming apparatus 100 and an example of a transport path of a sheet according to an embodiment will be described with reference to
The image forming apparatus 100 is, for example, a multi-function machine. The image forming apparatus 100 includes a display 110, a control panel 120, a printer unit 130, a sheet accommodation unit 140, and an image reading unit 200. The image forming apparatus 100 forms an image on a sheet using developer such as toner. The sheet is, for example, a paper or label sheet. The sheet may be any object as long as the image forming apparatus 100 can form an image on the surface of the sheet.
The display 110 is an image display device such as a liquid crystal display or an organic electro luminescence (EL) display. The display 110 displays various kinds of information regarding the image forming apparatus 100.
The control panel 120 includes a plurality of buttons. The control panel 120 receives an operation by a user. The control panel 120 outputs a signal according to the operation performed by the user to a control unit of the image forming apparatus 100. The display 110 and the control panel 120 may be configured as an integrated touch panel.
The printer unit 130 forms an image on a sheet based on image information generated by the image reading unit 200 or image information received via a communication path. For example, the printer unit 130 forms an image using developer such as toner. The sheet on which the image is formed may be a sheet accommodated in the sheet accommodation unit 140 or may be a sheet input by hand. The printer unit 130 includes an image forming unit 31, a fixing unit 32, a paper discharging unit 33, a transport member 34, and a detection unit 35.
The image forming unit 31 includes an intermediate transfer body 11, development units 12 to 16, a plurality of primary transfer rollers 17 (17-1 to 17-5), a secondary transfer unit 18, and an exposure unit 19. The development units 12 to 16 include photosensitive drums 121 to 161. For example, the image forming unit 31 operates as follows. The exposure unit 19 forms electrostatic latent images on the photosensitive drums 121 to 161 based on image information which is an image forming target. The development units 12 to 16 form visible images by attaching the developer to the electrostatic latent images. The primary transfer rollers 17-1 to 17-5 transfer the formed visible images to an image carrier (e.g., the intermediate transfer body 11). The intermediate transfer body 11 is an endless belt that is able to rotate in a direction indicated by an arrow 91. The intermediate transfer body 11 is rotated in the direction indicated by the arrow 91 to transport the transferred visible images up to the secondary transfer unit 18. The secondary transfer unit 18 transfers the visible images formed on the intermediate transfer body 11 to the sheet. Specifically, the secondary transfer unit includes a pair of rollers that press the sheet against the intermediate transfer body 11 to transfer the visible images to the sheet.
The fixing unit 32 fixes the visible images to the sheet by heating and pressurizing the visible images transferred to the sheet. The paper discharging unit 33 discharges the sheet on which the visible images are fixed by the fixing unit 32.
The transport members 34 (i.e., conveyors) transport the sheet. Each transport member 34 includes, for example, a pair of rotatable rollers. In other embodiments, the transport members 34 include one or more conveyor belts. The image forming apparatus 100 includes the plurality of transport members 34. The transport members 34 transport a sheet accommodated in the sheet accommodation unit 140 to the secondary transfer unit 18. The sheet transported to the secondary transfer unit 18 is transported to the fixing unit 32 by the transport members 34.
The detection unit 35 outputs a signal (hereinafter referred to as a “detection signal”) indicating whether the sheet transported by the transport member 34 passes through a predetermined position (hereinafter referred to as a “detection position”). The detection unit 35 may include any type of device or unit that is able to output a detection signal indicating whether the sheet is present in a corresponding detection position. The number of detection positions may be single or plural. The detection unit 35 may include, for example, detection devices 351-1 to 351-2 (i.e., sheet detection sensors). According to an exemplary embodiment, each of the detection devices 351-1 to 351-2 emits (e.g., radiates) a laser toward the detection position, receives reflected light of the radiated laser, and outputs a signal according to the received reflected light as a detection signal (e.g., each detection device may be a break beam sensor). The signal according to the reflected light is, for example, a signal according to the strength (e.g., magnitude, intensity, etc.) of the reflected light. The strength of the reflected light may vary based on whether or not a sheet is present at the corresponding detection position. By way of example, the sheet may block the laser, resulting in a reduced strength of the reflected light. The detection position differs for each detection device. For example, in
The sheet accommodation unit 140 accommodates a sheet to be used for the printer unit 130 to form an image.
The image reading unit 200 reads reading target image information as brightness and darkness of light. The image reading unit 200 records the read image information. The recorded image information may be transmitted to another information processing device via a network. The recorded image information may be formed as an image on a sheet by the printer unit 130.
Here, an example of the transport path of a sheet will be described. The image forming apparatus 100 is an apparatus that is designed so that a sheet is transported along a predetermined transport path. However, in some cases, a sheet invades into an inappropriate transport path and the sheet is moved up to a position at which a user may not extract the sheet. In
The communication unit 101 includes a communication interface that connects the image forming apparatus 100 to an external apparatus. The communication unit 101 communicates with the external apparatus through a wired or wireless connection and outputs the received information to the control unit 102. The communication unit 101 receives, for example, a printing job. The printing job may include image information and sheet size information. The sheet size information is information indicating a size of a forming target sheet on which an image indicated by the image information is formed.
The control unit 102 (i.e., a controller) is configured using a processor such as a CPU and a memory. The control unit 102 operates when the processor executes a program. The control unit 102 controls an operation of each functional unit included in the image forming apparatus 100. The control unit 102 controls, for example, an operation of the image forming unit 31. The control unit 102 controls, for example, an operation of the fixing unit 32. The control unit 102 controls, for example, an operation of the driving unit 104.
The control unit 102 determines whether the detection unit 35 is operating normally. For example, when one or more of the detection devices output a control signal indicating that a sheet does not pass through the detection position consecutively a predetermined number of times or more, the control unit 102 determines that the operation is not normal. Alternatively, when there is a detection device that constantly outputs a control signal indicating that a sheet is passing through the detection position while the image forming apparatus 100 is in a state in which no sheet should be passing through the detection position (e.g., the sheet has not yet been removed from the sheet accommodation unit 140, the detection device 351-2 indicates that a sheet is passing through its corresponding detection position prior to the detection device 351-1 indicating that the sheet is passing through its corresponding detection position), the control unit 102 may determine that the operation is not normal. When the detection unit 35 includes three or more detection devices, the control unit 102 may determine whether the operation of the detection unit 35 is normal as follows, for example. Specifically, when only one detection device outputs a detection signal indicating that the sheet does not pass through the detection position, the control unit 102 may determine that the operation is not normal. A determination result of normality or non-normality of the operation of the detection unit 35 by the control unit 102 is recorded in the storage unit 103 by the control unit 102.
The storage unit 103 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The storage unit 103 stores various kinds of information regarding the image forming apparatus 100. For example, the storage unit 103 stores a program to be executed by the processor of the control unit 102 in advance. The storage unit 103 stores information indicating a determination result of normality or abnormality of the operation of the detection unit 35 by the control unit 102 (hereinafter referred to as “error information”).
The driving unit 104 (i.e., an actuator) drives the transport member 34. The driving unit 104 is, for example, a motor that operates under the control of the control unit 102.
When a sheet does not invade into the inappropriate transport path, printing can be performed without the use of the detection device 351-1. If the detection device 351-1 is in an abnormal state, the detection device 351-2 can detect that the sheet is not appropriately transported. However, even if transportation of the sheet is stopped at this time, the sheet may have already invaded a distance along the intermediate transfer belt 11, and thus the user may not be able to remove the sheet if the size of the sheet is small.
Accordingly, in one embodiment, when the control unit determines that the detection device 351-1 is abnormal, the detection device 351-1 is invalidated. When the size of a printing target sheet is equal to or greater than a predetermined size, printing can still be performed in this state, as the sheet is long enough to protrude from the intermediate transfer belt 11 sufficiently to be removed by a user.
Conversely, when the operation is not normal (NO in ACT102), the control unit 102 determines whether the size of the sheet indicated by the sheet size information is equal to or greater than a pre-decided predetermined size (ACT108). When the size of the sheet is equal to or greater than the predetermined size (YES in ACT108), the control unit 102 controls the driving unit 104 to transport the sheet (ACT109). Subsequently, the image forming unit 31 forms a visible image on the transported sheet (ACT110). Subsequently, the fixing unit 32 fixes the visible image on the sheet (ACT111). Conversely, when the size of the sheet is less than the predetermined size (NO in ACT108), the control unit 102 causes the driving unit 104 to stop transporting the sheet (ACT112) (e.g., to prevent further transportation of the sheet).
The predetermined size in ACT108 is, for example, a predetermined length in the transport direction of the sheet. The predetermined length in the transport direction of the sheet is, for example, a length of the sheet at which the user may not extract the sheet when the sheet has reached a predetermined position. The predetermined length in the transport direction of the sheet is, for example, longer than a distance from a position at which the user extracts the sheet (i.e., an extraction position) to a predetermined position at which the user may not extract the sheet. More specifically, the predetermined length is a length of a distance or more in which the sheet is transported along an inappropriate transport path until the control unit receives a signal indicating that the sheet is not correctly transported from the detection device 351-2, which is normally operating, and stops the transporting of the sheet. The position at which the user extracts the sheet is, for example, the position of the secondary transfer unit 18. In this case, since the sheet invading to the inappropriate transport path does not invade up to a predetermined position at which the sheet is not extractable, the user can extract the sheet. By way of example, the sheet may be incorrectly transported along the intermediate transfer body 11 instead of moving to the fixing unit 32. The sheet may travel along this inappropriate transfer path for a first period of time piror to the detection device 351-2 indicating that the sheet is being incorrectly transported and causing the control unit 102 to stop transportation of the sheet. This first period of time may correspond to a first distance that the sheet travels along the intermediate transfer body 11. This first distance may be the predetermined distance. If the length of the sheet is less than the predetermined distance, the end of the sheet may have moved beyond a location where the end of a sheet is accessible to the user. If the length of the sheet is greater than or equal to the predetermined length, the end of the sheet may be accessed by an operator (e.g., at the secondary transfer device 18) to remove the sheet.
The image forming apparatus 100 that has such a configuration includes the control unit 102 that controls an operation of the driving unit 104 according to the size of a sheet when the detection unit 35 does not normally operate. Therefore, even when a sensor is broken down, non-movement of the sheet up to the position at which the user may not extract the sheet and formation of an image can be compatible.
The detection unit 35 may not necessarily include the plurality of detection devices when the detection unit 35 can detect whether the sheet passes through a predetermined detection position. The detection unit 35 may include one detection device.
In the fixing unit 32 according to the embodiment, a method of fixing a visible image to a sheet by performing heating via a film-shaped member may be applied.
According to at least one of the above-described embodiments, the control unit 102 is included. Thus, even when the sensor is broken down, non-movement of the sheet up to the position at which the user may not extract the sheet and formation of an image can be compatible.
Some or all of the functions of the image forming apparatus 100 may be realized using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA). A program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a storage device such as a portable medium such as a flexible disc, a magneto-optic disc, a ROM, or a CD-ROM or a hard disk embedded in a computer system. The program may be transmitted via an electrical communication line.
While certain embodiments have been described these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms: furthermore various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
