CN110275401B - Optional device monitoring device, image forming apparatus, and monitoring method - Google Patents

Abstract

The invention relates to an optional device monitoring device, an image forming apparatus and a monitoring method, wherein the optional device monitoring device comprises optional devices, a sensor and a central processing unit, wherein m optional devices and sensors exist respectively, the central processing unit executes a monitoring main program for monitoring all m optional devices, a plurality of monitoring periods are included in one cycle till the monitoring of all m optional devices is finished, the monitoring main program comprises a monitoring subprogram, in the monitoring subprogram, the central processing unit monitors n optional devices including at least one optional device which is not monitored in one monitoring period, m is an integer larger than or equal to 2, and n is an integer larger than 1 and smaller than m. Even when a plurality of paper feed cassettes are mounted on the machine main body, information on the paper feed cassettes can be communicated with the machine main body in real time without being limited by the processing capability of the CPU.

Description

Optional device monitoring device, image forming apparatus, and monitoring method

Technical Field

The present invention relates to an optional device monitoring device, an image forming apparatus, and a monitoring method, and more particularly, to an optional device monitoring device, an image forming apparatus, and a monitoring method capable of communicating information on a plurality of paper feed cassettes with an apparatus main body in real time without being limited by the processing capability of a CPU even when the apparatus main body is mounted with the paper feed cassettes.

Background

In the conventional technique, when a plurality of paper feed cassettes are mounted, the control section of the image forming apparatus needs to communicate with each paper feed cassette to monitor the state thereof, and since the processing capability of the CPU of the control section is limited and the communication time required for each paper feed cassette is the same, the paper feed cassettes that can be processed in a predetermined control cycle are constant. Further, in order to keep the communication load with each paper feed cassette within a certain range, the CPU of the control unit has to be monitored for the utilization rate, but the monitoring of the CPU requires further processing capability of the CPU itself, for example, a higher circuit is required for the circuit board, so that the CPU having more excellent performance and higher price has to be selected, and the cost thereof increases. Meanwhile, since the monitoring of the utilization rate of the CPU occupies a part of the processing capacity of the CPU, it causes a waste of computational resources. (patent document 1)

Further, in the related art, there are a method of performing communication by switching between a broadcast mode and a unicast mode, and a method of performing asynchronous communication. However, switching between broadcast and unicast modes can complicate the communication scheme, and the broadcast mode is not favorable for information security. Further, the asynchronous communication method cannot acquire information in real time, which may cause the machine body to have hysteresis with respect to the paper feed cassette information.

Patent document 1: CN102651790A

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object thereof is to provide an optional apparatus monitoring apparatus, an image forming apparatus, and a monitoring method that can communicate information on a plurality of paper feed cassettes with an apparatus main body in real time without being limited by the processing capability of a CPU even when the apparatus main body is equipped with the paper feed cassettes.

An optional device monitoring device, comprising: an optional device disposed in a main body of the image forming apparatus; a sensor which is disposed in correspondence with the optional device and detects a state of the optional device; and a central processing unit that communicates with the sensor to monitor a state of the optional device, wherein m optional devices and the sensor are present, the central processing unit executes a monitoring main program that monitors all of the m optional devices, the monitoring main program includes a monitoring subroutine that includes a plurality of monitoring cycles in one cycle until monitoring of all of the m optional devices is completed, and the central processing unit monitors n optional devices including at least one optional device that has not been monitored in one monitoring cycle, where m is an integer greater than or equal to 2 and n is an integer greater than 1 and less than m.

In the monitoring subroutine, the central processing unit monitors n optional devices including at least one optional device that has not been monitored in one monitoring cycle, and therefore, even when m (for example, 5) optional devices are mounted on the machine main body, information of the optional devices can be communicated with the machine main body in real time without being limited by the processing capability of the CPU. This reduces the load on the CPU and improves the operation efficiency of the entire device. In other words, the monitoring period of the CPU is not changed, the monitoring period of the present invention is the same as the original monitoring period of the CPU, and the number of optional devices monitored in the same monitoring period is reduced, so that the workload of the CPU per unit time is reduced.

In addition, when the number of optional devices is to be further increased according to actual needs, for example, when the number of optional devices is increased to 6 or more, the CPU with the existing performance can be used for coping without replacing a new CPU with more excellent performance and more expensive price, in other words, the number of optional devices can be further increased without requiring higher CPU processing capacity. In addition, as the number of the optional devices is increased, the times of opening or closing the optional devices by workers can be reduced, and manual intervention is reduced.

Further, since it is not necessary to monitor the usage rate of the CPU in real time as in the conventional art, it is possible to avoid waste of calculation resources, and since a mechanism for monitoring the usage rate of the CPU can be omitted, it is possible to simplify the configuration.

In addition, since the original monitoring period of the CPU is not changed, it is possible to prevent other problems such as a decrease in control accuracy due to a simple increase in the period, as compared with a case where the period is simply increased.

In addition, in the invention, the broadcasting mode is not needed to be used, and the switching between the broadcasting mode and the unicast mode is not needed, thereby not only ensuring the information security, but also improving the communication efficiency. In addition, compared with using an asynchronous communication method, the monitored states (operating state, presence or absence of paper, etc.) of the optional devices can be sent to the CPU in real time, which not only ensures data consistency but also improves paper feeding performance.

In addition, in the invention, the monitoring in the working process of the machine is continuously carried out, so that after the paper of the current optional device is used, the current optional device can be immediately switched to other idle optional devices without suspending the current task, thereby improving the overall operation efficiency of the machine.

In the present invention, the relationship between the number of optional devices to be monitored and the number of optional devices monitored in one monitoring period can be summarized as follows: when the number of optional devices is m and the number of optional devices to be monitored in one monitoring period is n, the above-described technical effects can be achieved on the premise that m is an integer of 2 or more and n is an integer of 1 or more and less than m.

In the optional device monitoring apparatus, the cpu determines the m value after acquiring the number of the optional devices.

The CPU may determine the m value after acquiring the number of optional devices for the m value, and the m value may be matched with the number of optional devices installed in the machine, or the m value may be manually input by the user or the service person as needed at a later stage, for example, when the number of optional devices is 5, or the user or the service person may change the m value as needed when the user or the service person thinks that all optional devices are not necessary to use, for example, the m value may be set to 3 for 3 optional devices to be used. By setting the value of m, the selectivity of the control mode can be increased, and the degree of freedom of control is improved.

The optional device monitoring apparatus further includes a determination unit configured to determine whether or not an optional device in use exists among the m optional devices, and a monitoring target of the monitoring subprogram when the optional device in use exists is different from a monitoring target of the monitoring subprogram when the optional device in use does not exist. When the determination unit determines that there is an optional device in use, each of the monitoring subroutines includes an optional device in use as a monitoring target. When the determination unit determines that there is no optional device in use, at least a part of the monitoring objects do not overlap among the monitoring subroutines.

When the determination unit determines that there is no optional device in use, the non-task monitoring subroutine is executed such that a plurality of monitoring periods until the monitoring of all of the m optional devices is completed form one cycle (may be a single cycle).

When the determination unit determines that there is an optional device in use, the task monitoring subroutine is executed such that a plurality of monitoring periods until the monitoring of all m optional devices is completed form a single loop, and when the task is not completed, the loop is repeated so that the optional device in use is first monitored in each task monitoring subroutine, that is, the optional device in use is included in the monitored object, and when the task is completed, the loop is exited from the loop and enters the non-task monitoring subroutine.

In this way, when there is no optional device in use, at least a part of the monitoring target does not overlap between the monitoring subroutines, and thus each optional device can be completely monitored without fail. In the case where there is an optional device in use, since the possibility of occurrence of an abnormality such as paper-out or paper jam in the optional device in use is much higher than that in other optional devices, in each monitoring subroutine, the monitoring object includes the optional device in use, and the optional device in which an abnormality is more likely to occur can be monitored more specifically and more effectively. By combining the two monitoring methods, the monitoring efficiency can be effectively improved.

In the optional device monitoring apparatus, the cpu may change the value of n. The central processing unit determines the n value according to the use condition or the processing capacity of the central processing unit.

The CPU can change the N value according to actual needs, for example, the N value may be changed according to the processing capability of the CPU itself, or the N value of the subsequent monitoring subroutine may be changed according to actual needs with respect to the previous monitoring subroutine. By changing the value of n, not only can a control mode most suitable for the processing capacity of the CPU be selected, but also other control modes required by a user or maintenance personnel can be selected according to actual needs, so that the selectivity is increased, and the degree of freedom of control is improved.

In the optional device monitoring device, the optional device includes at least a paper feed cassette.

The optional device monitoring device includes not only the paper feed cassette but also other post-processing devices such as a paper discharge cassette, a paper folding device, and a nailing device, and when other kinds of optional devices are applied, the technical effects described above can be achieved similarly.

An image forming apparatus is characterized by comprising the optional apparatus monitoring apparatus.

A method for monitoring an optional device monitoring device, the method for monitoring an optional device monitoring device, comprising: executing a monitoring main program for monitoring all m optional devices; and a step of including a plurality of monitoring periods in one cycle until monitoring of all m optional devices is completed, and including a monitoring subroutine in the monitoring main program, wherein in the monitoring subroutine, n optional devices including at least one optional device that has not been monitored are monitored in one monitoring period, m is an integer of 2 or more, and n is an integer of 1 or more and less than m.

Drawings

Fig. 1 is a structural diagram showing an image forming apparatus according to the present invention.

Fig. 2 is a schematic diagram showing a main configuration of an image forming apparatus of the present invention.

Fig. 3 is a flowchart showing a monitoring control flow of the monitoring main routine.

Fig. 4 is a flowchart showing a flow of determining the state of the machine.

Fig. 5 is a flowchart showing a monitoring control flow of the non-task monitoring subroutine.

Fig. 6 is a flowchart showing a monitoring control flow of the task monitoring subroutine.

Fig. 7 is a flowchart showing a flow of determination as to whether or not the paper feed cassette is in use.

Fig. 8 is a flowchart showing communication between the CPU and each paper feed cassette.

Description of the drawings:

1 \ 8230a image forming apparatus; 141 \ 8230and paper supply carton (optional device); 141a 8230, a first paper supply cassette; 141b 8230a second paper supply cassette; 141c 8230a third paper supply cassette; 141d 8230a fourth paper supply cassette; 141e 8230a fifth paper supply cassette; 144a 8230, a first sensor; 144b 8230a second sensor; 144c 8230a third sensor; 144d 8230a fourth sensor; 144e 8230a fifth sensor; 18 8230a paper feed cassette monitoring device (optional device monitoring device); 171 \ 8230and CPU (central processing unit); 170a 8230and a judging part.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Further, it will be apparent to those skilled in the art that many alternatives thereof are possible in light of the above disclosure, and that the present invention is not limited to the preferred embodiments described herein.

First, the overall configuration of the image forming apparatus of the present invention will be described. Fig. 1 is a configuration diagram showing an image forming apparatus according to the present invention, and fig. 2 is a schematic diagram showing a main configuration of the image forming apparatus according to the present invention.

As shown in fig. 1 and 2, the image forming apparatus 1 of the present invention forms an image by primary-transferring toner images of colors Y (yellow), M (magenta), C (cyan), and K (black) formed on the photosensitive drums 213 to the intermediate transfer belt 221, superimposing the toner images of the four colors on the intermediate transfer belt 221, and then secondary-transferring the superimposed toner images to a sheet.

As shown in fig. 1, the image forming apparatus 1 generally includes an image reading unit 11, an operation display unit 12, an image processing unit 13, an image forming unit 20, a paper feed unit 14, a paper discharge unit 15, a paper transport unit 16, and a control unit 17.

The control Unit 17 includes a Central Processing Unit 171 (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), and the like, and centrally controls the operations of the respective blocks of the image forming apparatus 1. The control unit 17 transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication Network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via a communication unit (not shown).

The image reading unit 11 includes an Auto Document feed cassette 111 called an ADF (Auto Document Feeder), a Document image scanning device 112 (scanner), and the like.

The automatic document sheet feed cassette 111 conveys a document placed on a document tray by a conveying mechanism and feeds the document to the document image scanning device 112. The document image scanning Device 112 optically scans a document fed from the automatic document feeding cassette 111 onto the contact glass or a document placed on the contact glass, forms an image of reflected light from the document on a light receiving surface of a CCD (Charge Coupled Device) sensor 112a, and reads a document image. The image reading unit 11 generates input image data based on the reading result of the document image scanning device 112. The image processing unit 13 performs predetermined image processing on the input image data.

The operation Display unit 12 is constituted by, for example, a Liquid Crystal Display (LCD) with an operation panel, and functions as a Display unit 121 and an operation unit 122. The display unit 121 displays various operation screens, image status displays, operation statuses of the functions, and the like, based on a display control signal input from the control unit 17. The operation unit 122 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs an operation signal to the control unit 17. The user can operate the operation display portion 12 to perform settings related to image formation, such as document setting, image quality setting, magnification setting, application setting, output setting, single-sided/double-sided setting, and paper setting.

The image processing unit 13 includes a circuit and the like for performing digital image processing corresponding to initial setting or user setting on input image data. For example, the image processing unit 13 performs gradation correction based on the gradation correction data under the control of the control unit 17. The image processing unit 13 performs various correction processes such as color correction and shading correction on the input image data. The image forming unit 20 is controlled based on the image data obtained by performing these processes.

The image forming unit 20 includes: a toner image forming section 21 for forming a toner image based on color toners of Y component, M component, C component, and K component from input image data; an intermediate transfer section 22 for transferring the toner image formed by the toner image forming section 21 to a sheet; and a fixing device 23 for fixing the transferred toner image to paper.

The toner image forming portion 21 includes four toner image forming portions 21Y, 21M, 21C, and 21K for Y component, M component, C component, and K component. Since the toner image forming portions 21Y, 21M, 21C, and 21K have the same configuration, common components are denoted by the same reference numerals for convenience of illustration and description, and Y, M, C, and K are added to the reference numerals for distinguishing the components. In fig. 1, only the constituent elements of the toner image forming portion 21Y for the Y component are denoted by reference numerals, and the constituent elements of the other toner image forming portions 21M, 21C, and 21K are denoted by reference numerals.

The toner image forming unit 21 includes an exposure device 211, a developing device 212, a photosensitive drum 213, a charging device 214, a drum cleaning device 215, and the like.

The photosensitive drum 213 is an Organic Photoconductor (OPC) of a negative Charge type in which an undercoat Layer (UCL: undercoat Layer), a Charge Generation Layer (CGL: charge Generation Layer), and a Charge Transport Layer (CTL: charge Transport Layer) are laminated in this order on the outer surface of an aluminum conductive cylindrical body (aluminum raw material pipe), for example.

The charging device 214 is constituted by a corona discharge generator such as a grid-controlled corona charging device or a corotron charging device. The charging device 214 charges the surface of the photosensitive drum 213 with a negative polarity by corona discharge as well.

The exposure device 211 is constituted by, for example, an LED array in which a plurality of Light Emitting Diodes (LEDs) are linearly arranged, an LPH drive unit (driver IC) for driving the respective LEDs, and an LED print head having a lens array for forming an image of Light emitted from the LED array on the photosensitive drum 213. One LED of the LED array corresponds to one point of the image. The control unit 17 controls the LPH drive unit so that a predetermined drive current flows through the LED array to cause a specific LED to emit light.

The exposure device 211 irradiates the photosensitive drum 213 with light corresponding to an image of each color component. The positive charge generated in the charge generation layer of the photosensitive drum 213 by the irradiation of light is transported to the surface of the charge transport layer, thereby neutralizing the surface charge (negative charge) of the photosensitive drum 213. Thereby, an electrostatic latent image of each color component is formed on the surface of the photosensitive drum 213 due to a potential difference with the surroundings.

The developing device 212 accommodates developers of respective color components (for example, a two-component developer composed of toner and magnetic carrier). The developing device 212 forms a toner image by visualizing the electrostatic latent image by causing toner of each color component to adhere to the surface of the photosensitive drum 213. Specifically, a developing bias is applied to the developer carrier (developing roller), and an electric field is formed between the photosensitive drum 213 and the developer carrier. The charged toner on the developer carrier moves and adheres to the exposed portion on the surface of the photosensitive drum 213 due to the potential difference between the photosensitive drum 213 and the developer carrier.

The drum cleaning device 215 has a drum cleaning blade or the like which is in sliding contact with the surface of the photosensitive drum 213, and removes transfer residual toner remaining on the surface of the photosensitive drum 213 after the primary transfer.

The intermediate transfer section 22 includes an intermediate transfer belt 221, a primary transfer roller 222, two or more support rollers 223, a secondary transfer roller 224, a belt cleaning device 225, and the like.

The intermediate transfer belt 221 is an endless belt, and is looped around a plurality of support rollers 223. At least one of the plurality of support rollers 223 is constituted by a drive roller, and the others are constituted by driven rollers. By rotating the drive roller, the intermediate transfer belt 221 travels at a constant speed in the arrow a direction.

The primary transfer roller 222 is disposed on the inner peripheral surface side of the intermediate transfer belt 221 so as to face the photosensitive drum 213 for each color component. The primary transfer roller 222 is pressed against the photosensitive drum 213 so as to sandwich the intermediate transfer belt 221, thereby forming a primary transfer nip portion (hereinafter referred to as "primary transfer portion") for transferring the toner image from the photosensitive drum 213 to the intermediate transfer belt 221.

The secondary transfer roller 224 is disposed on the outer peripheral surface side of the intermediate transfer belt 221 so as to face one of the plurality of support rollers 223. The support roller 223 disposed opposite to the intermediate transfer belt 221 is referred to as a support roller. The secondary transfer roller 224 is pressed against the backup roller so as to sandwich the intermediate transfer belt 221, thereby forming a secondary transfer nip portion (hereinafter referred to as "secondary transfer portion") for transferring the toner image from the intermediate transfer belt 221 to the paper.

In the primary transfer section, the toner images on the photosensitive drums 213 are sequentially superimposed and primary-transferred onto the intermediate transfer belt 221. Specifically, a primary transfer bias is applied to the primary transfer roller 222, and a charge having a polarity opposite to that of the toner is applied to the lower surface side of the intermediate transfer belt 221 (the side in contact with the primary transfer roller 222), whereby the toner image is electrostatically transferred to the intermediate transfer belt 221.

Thereafter, when the sheet passes through the secondary transfer section, the toner image on the intermediate transfer belt 221 is secondarily transferred onto the sheet.

Specifically, a secondary transfer bias is applied to the secondary transfer roller 224, and a charge of a polarity opposite to that of the toner is applied to the lower surface side of the paper (the side in contact with the secondary transfer roller 224), whereby the toner image is electrostatically transferred to the paper. The sheet to which the toner image is transferred is conveyed toward the fixing device 23.

The belt cleaning device 225 has a belt cleaning blade or the like which is in sliding contact with the surface of the intermediate transfer belt 221, and removes transfer residual toner remaining on the surface of the intermediate transfer belt 221 after the secondary transfer.

In the intermediate transfer section 22, instead of the secondary transfer roller 224, a configuration may be adopted in which a secondary transfer belt is looped over a plurality of support rollers including a secondary transfer roller (so-called belt-type secondary transfer unit).

The fixing device 23 includes: a heating roller 231 disposed on the fixing surface (surface on which a toner image is formed) side of the sheet; a pressure roller 232 disposed on the back surface (opposite surface to the fixing surface) side of the sheet and facing the heating roller 231 via the sheet conveyance path; a heating source 233 that heats the fixing surface side member; and a pressure separation portion (not shown) for bringing the rear surface side supporting member into pressure contact with the fixing surface side member. The sheet of paper, which is conveyed along the paper passage after the toner image is secondarily transferred, is heated and pressurized when passing through the fixing device 23. Thereby, the toner image is fixed on the paper.

The paper feed unit 14 includes a plurality of paper feed cassettes 141. The paper feed unit 14 includes a paper feed roller unit 143 and the like, and feeds paper fed from the paper feed cassette 141 or the manual feed paper feed unit 142 to the paper transport unit 16.

The sheet discharge portion 15 includes a sheet discharge roller portion 151 and the like, and discharges the sheet fed out from the sheet conveying portion 16 to the outside of the apparatus.

The paper conveying unit 16 includes a main conveying unit 161, a switchback conveying unit 162, a reverse-side printing conveying unit 163, a paper passage switching unit (not shown), and the like. A part of the paper conveying section 16 is incorporated into one unit together with the fixing device 23, for example, and is detachably attached to the image forming apparatus 1 (paper conveying unit ADU).

The main transport section 161 includes a plurality of transport roller sections including an entrance roller section 165 disposed upstream in the paper transport direction of the secondary transfer section as a paper transport element for nipping and transporting paper. The main transport section 161 transports the paper fed from the paper feed cassette 141 or the paper fed via the manual feed paper feed section 142 through the image forming section 20 (secondary transfer section, fixing device 23), and transports the paper fed from the image forming section 20 (fixing device 23) toward the paper discharge section 15.

The switchback conveying unit 162 temporarily stops the paper fed from the fixing device 23, reverses the conveying direction, and conveys the paper to the paper discharge unit 15 or the reverse-side printing conveying unit 163.

The reverse side printing conveying unit 163 is a circulation path for conveying the paper diverted by the diverting conveying unit 162 to the main conveying unit 161. In the main conveying section 161, the sheet passes with the second surface (back surface) facing upward.

The paper path switching unit (not shown) switches the paper path by discharging the paper fed from the fixing device 23 in a state as it is, reversing the paper to discharge the paper, or conveying the paper to the back-side printing conveying unit 163. Specifically, the control unit 17 controls the operation of the paper path switching unit based on the processing content (single-sided/double-sided printing, face-up/face-down paper discharge, and the like) of the image forming process.

An image forming apparatus 1 (hereinafter, for convenience of explanation, the image forming apparatus 1 may be simply referred to as a machine including a plurality of devices such as a printer, a copier, and a multifunction machine) according to the present invention includes a plurality of optional devices, and includes a plurality of optional device monitoring devices for monitoring and controlling the plurality of optional devices in correspondence with the plurality of optional devices. The optional device may be, for example, a paper feed cassette or a paper discharge cassette, or may be other post-processing devices such as a paper folding device and a nailing device. As shown in fig. 2, a paper feed cassette 141 and a paper feed cassette monitoring device 18 corresponding to the paper feed cassette 141 will be described as an example.

As shown in fig. 1 and 2, in the image forming apparatus 1 of the present invention, there are provided a plurality of paper feed cassettes as optional means, namely: first paper feed cassette 141a, second paper feed cassette 141b, third paper feed cassette 141c, fourth paper feed cassette 141d, and fifth paper feed cassette 141e (hereinafter, when no distinction is made, first to fifth paper feed cassettes 141a to 141e may be simply referred to as paper feed cassettes 141 or paper feed cassettes 141a to 141 e). The first to fifth paper feed cassettes 141a to 141e are stacked in the vertical direction in the order of 141a, 141b, 141c, 141d, and 141e from top to bottom, and various print sheets such as print paper for printing are stored in the paper feed cassettes 141a to 141 e. Note that, as necessary, a plurality of types of paper sheets having different sizes and thicknesses can be stored in the first to fifth paper feed cassettes 141a to 141 e.

The paper feed cassettes 141a to 141e will be specifically described below. The first paper feed cassette 141a is the uppermost cassette among the plurality of paper feed cassettes 141, and mainly includes a first paper feed tray 141a-1 for receiving paper and a first paper feed roller 141a-2 for discharging paper received on the first paper feed tray 141a-1 toward the downstream side of the conveyance path when the machine is in operation.

The second paper feed cassette 141b is a cassette provided adjacent to the first paper feed cassette 141a on the lower side of the first paper feed cassette 141a among the plurality of paper feed cassettes 141, and mainly includes a second paper feed tray 141b-1 for carrying paper and a second paper feed roller 141b-2 for carrying out the paper carried on the second paper feed tray 141b-1 toward the downstream side of the conveyance path when the machine is in operation.

The third paper feed cassette 141c is a cassette provided adjacent to the second paper feed cassette 141b on the lower side of the second paper feed cassette 141b among the plurality of paper feed cassettes 141, and mainly includes a third paper feed tray 141c-1 for carrying paper and a third paper feed roller 141c-2 for carrying out the paper carried on the third paper feed tray 141c-1 toward the downstream side of the conveyance path when the machine is in operation.

The fourth paper feed cassette 141d is a cassette provided adjacent to the third paper feed cassette 141c on the lower side of the third paper feed cassette 141c among the plurality of paper feed cassettes 141, and mainly includes a fourth paper feed tray 141d-1 for receiving paper and a fourth paper feed roller 141d-2 for discharging paper received on the fourth paper feed tray 141d-1 toward the downstream side of the conveyance path when the machine is in operation.

The fifth paper feed cassette 141e is the lowermost paper feed cassette among the plurality of paper feed cassettes 141, is provided below the fourth paper feed cassette 141d adjacent to the fourth paper feed cassette 141d, and mainly includes a fifth paper feed tray 141e-1 for receiving paper and a fifth paper feed roller 141e-2 for discharging paper received on the fifth paper feed tray 141e-1 toward the downstream side of the conveyance path during operation of the machine.

A plurality of sensors for detecting the states of the first to fifth paper feed cassettes 141a to 141e, i.e., a first sensor 144a, a second sensor 144b, a third sensor 144c, a fourth sensor 144d, and a fifth sensor 144e are arranged corresponding to the first to fifth paper feed cassettes 141a to 141e (hereinafter, when no distinction is made, the first to fifth sensors 144a to 144e may be simply referred to as sensors 144a to 144 e). First to fifth sensors 144a to 144e are disposed on the downstream side of the first to fifth paper feed rollers 141a to 141e-2 in the conveyance direction in proximity to the first to fifth paper feed rollers 141a to 141e-2, and detect the states of the first to fifth paper feed cassettes 141a to 141 e.

The detected states of the paper feed cassettes 141a to 141e include, for example: the usage status of the paper feed cassettes 141a to 141e, that is, which paper feed cassette is currently in use, which paper feed cassette is in an idle state, which paper feed cassette is in an abnormal state (e.g., a paper jam), which paper feed cassette has been opened, and the like.

The central processing unit 171 (hereinafter, simply referred to as CPU) included in the control unit 17 can monitor the states of the first to fifth paper feed cassettes 141a to 141e by communicating with the first to fifth sensors 144a to 144e.

For example, in the paper feed cassette monitoring device 18 of the present invention, 5 paper feed cassettes 141a to 141e and sensors 144a to 144e are provided, that is, a first paper feed cassette 141a and a first sensor 144a are provided, a second paper feed cassette 141b and a second sensor 144b are provided, a third paper feed cassette 141c and a third sensor 144c are provided, a fourth paper feed cassette 141d and a fourth sensor 144d are provided, and a fifth paper feed cassette 141e and a fifth sensor 144e are provided.

The CPU171 executes the monitoring main program for the entire period from power on to power off. The monitoring main program is a main program for monitoring the states of all of the 5 paper feed cassettes 141a to 141e, and the entire period from power-on to power-off includes, for example, the entire initial operation period from power-on to the end of the initial operation; after the initial action is finished, the machine is in a state of waiting for a task, and the whole standby period before the task is started or the power supply is turned off; the whole task period from the start of the task to the end of the task; and the machine encounters a fault in the task, the machine enters a faulted state, the entire machine exception period before reset is not restored, etc.

The monitoring main program includes a monitoring subroutine in which the CPU monitors 2 paper feed cassettes including at least one paper feed cassette not monitored in the cycle for one monitoring period, and the monitoring routine includes a plurality of monitoring periods in one cycle until the monitoring of all of the 5 paper feed cassettes 141a to 141e is completed. (hereinafter, "not monitored in a loop" may be simply referred to as "not monitored", and "monitored in a loop" may be simply referred to as "monitored")

The monitoring subroutine is repeatedly executed during the entire period from power-on to power-off, and the monitoring cycle is the time required until the monitoring of 2 paper feed cassettes 141a to 141e is completed, and is appropriately adjusted according to the processing capacity of the CPU171 and the number of paper feed cassettes to be monitored. The specific monitoring control flow of the monitoring main routine and the monitoring subprogram will be described in detail later.

The paper feed cassette monitoring device 18 of the present invention is provided with a determination unit 170a (see fig. 8), specifically, the CPU171 is provided with a determination unit 170a that is capable of determining whether or not an abnormality or the like has occurred in a part of the device, and also capable of determining whether or not a paper feed cassette in use is present among the paper feed cassettes 141a to 141e as shown in fig. 8.

A specific monitoring control flow of the sheet cassette monitoring device 18 according to the present invention will be described below.

< monitoring control flow of monitoring main program >

Fig. 3 is a flowchart showing a monitoring control flow of the monitoring main routine. As shown in fig. 3, the CPU171 executes a monitoring main routine for monitoring the states of all of the 5 paper feed cassettes 141a to 141e, and the entire process of the monitoring main routine is performed in a plurality of consecutive monitoring cycles, and the CPU171 determines the machine state while executing the monitoring subprogram for each monitoring cycle.

Specifically, after the monitoring main routine is started (S01), the CPU171 performs processing based on the determination result of the determination unit 170a regarding the state of the machine in the previous monitoring period (S02), and specifically, when the determination result is that the machine is in the initial operation (S03), the machine is in an abnormal state (S04), or is in a standby state (S05) in the previous monitoring period, the CPU171 executes the non-task monitoring subroutine in the present monitoring period (S07); if the determination result is that the device is in the task in the previous monitoring period (S06), the CPU171 executes a task monitoring subroutine in the current monitoring period (S08). After the non-task monitoring routine or the task monitoring routine in the current monitoring cycle is completed, the process returns to step S02, and the CPU171 performs the processing again based on the determination result, adjusts the type of the monitoring routine executed in the current monitoring cycle, and details the non-task monitoring routine and the task monitoring routine.

Through the monitoring control flow, the CPU171 can continuously execute the monitoring subprogram, and at the same time, based on the determination result of the machine state in the previous monitoring cycle, can quickly adjust the type of the monitoring subprogram executed in the current monitoring cycle, thereby improving the detection efficiency of the entire machine.

Since the device is in the initial operation immediately after the power is turned on, the CPU171 executes the non-task monitoring subroutine in the first monitoring cycle.

< machine State decision flow >

Next, a specific flow of determining the machine state will be described. Fig. 4 is a flowchart showing a flow of determining the state of the machine.

As shown in fig. 4, after the power is turned on (S101), the execution of the monitoring main program is started (S102), and an initial operation of initializing the device is performed (in this case, the execution of the non-task monitoring sub program is started) (S103). The initial operation is performed not only after the power is turned on but also at the time of restarting the sleep mode, opening or closing the door, or the like.

Next, the determination unit 170a determines whether or not there is an abnormality in the apparatus (for example, door opening, paper jam, abnormal operation of components, and the like in any case) (S104). If it is determined that the device is abnormal, the process related to the resolution of the abnormality is executed and the determination in step S104 is repeated, and if it is determined that the device is not abnormal, the standby mode is entered (in this case, the non-task monitoring subroutine is continued) (S105).

In the standby mode, the determination unit 170a determines whether or not there is an abnormality in the apparatus (S106), and if it is determined that there is an abnormality in the apparatus, it executes a process related to the resolution of the abnormality and repeats the determination in step S106, and if it is determined that there is no abnormality in the apparatus, it determines whether or not there is a job related to the apparatus, such as printing (S107). If it is determined that there is a task, the task is executed (in this case, execution of the task monitoring subroutine is started) (S108), and if it is determined that there is no task, the operation returns to the standby mode (S105).

After step S108, it is determined again whether or not there is an abnormality in the machine (S109), and if it is determined that there is an abnormality in the machine, the process related to the resolution of the abnormality is executed and the determination in step S109 is repeated, and if it is determined that there is no abnormality in the machine, it is determined whether or not the task has been completed (S110). If it is determined that the task is not completed, the determination in step S110 is repeated, and if it is determined that the task is completed, the program returns to the standby mode (in this case, the non-task monitoring subroutine is executed again) (S105). When the power is turned off, the monitoring main program is ended.

< monitor control flow of non-task monitor subroutine >

The following describes a monitoring control flow of the non-task monitoring subroutine. Fig. 5 is a flowchart showing a monitoring control flow of the non-task monitoring subroutine.

In the present invention, when the machine is in an initial operation (S03), in an abnormal state (S04), or in a standby state (S05), the CPU171 repeatedly executes a non-task monitoring subroutine of: in the non-task monitoring subroutine, 2 paper feed cassettes including at least one paper feed cassette not monitored in the loop are monitored in one monitoring period, wherein the loop may be understood as a period from the first monitoring period to the third monitoring period in fig. 5, or may be understood as a period from the first monitoring period to the fifth monitoring period in fig. 5, and the detailed description will be given later.

In addition, when the determination unit 170a determines that there is a task during the execution of the non-task monitoring subroutine, in other words, when the determination result of the determination unit 170a is that the machine is in the task in the previous monitoring period, the non-task monitoring subroutine is terminated and the process proceeds to the task monitoring subroutine.

Specifically, as shown in fig. 5, during the execution of the non-task monitoring subroutine, a first monitoring cycle is started, the non-task monitoring subroutine is executed for the first time, and after the CPU171 monitors the first paper feed cassette 141a that has not been monitored in the first monitoring cycle (S201), the second paper feed cassette 141b that has not been monitored is monitored (S202).

After the first non-task monitoring subroutine is finished, if the determination unit 170a determines that there is a task, the non-task monitoring subroutine is finished and the process proceeds to the task monitoring subroutine, and if the determination unit 170a determines that there is no task, the process proceeds to the second monitoring cycle and the second non-task monitoring subroutine is executed. During the execution of the second non-task monitoring subroutine, the CPU171 monitors the unmonitored third paper feed cassette 141c in the second monitoring period (S203), and thereafter monitors the unmonitored fourth paper feed cassette 141d (S204).

After the second non-task monitoring subroutine is finished, if the determination unit 170a determines that there is a task, the non-task monitoring subroutine is finished and the process proceeds to the task monitoring subroutine, and if the determination unit 170a determines that there is no task, the process proceeds to a third monitoring cycle and the third non-task monitoring subroutine is executed. During the execution of the third non-task monitoring subroutine, the CPU171 monitors the unmonitored fifth paper feed cassette 141e in the third monitoring period (S205), and then monitors the monitored first paper feed cassette 141a again (S206).

After the third non-task monitoring subroutine is finished, if the determination unit 170a determines that there is a task, the non-task monitoring subroutine is finished and the task monitoring subroutine is entered, and if the determination unit 170a determines that there is no task, the first monitoring cycle is returned and the first non-task monitoring subroutine is executed again.

In other words, it can also be understood that: in the non-task monitoring subroutine, the first to third monitoring periods from the end of monitoring of all of the 5 paper feed cassettes 141a to 141e constitute one cycle, and if there is no task, the cycle is repeated so that at least a part of the monitoring target does not overlap.

As shown by the broken line in fig. 5, after the third non-task monitoring subroutine is finished, if the determination unit 170a determines that there is a task, the non-task monitoring subroutine may be finished and the routine may be entered into the task monitoring subroutine, and if the determination unit 170a determines that there is no task, the routine may be entered into the fourth monitoring cycle and the fourth non-task monitoring subroutine may be executed. During execution of the fourth non-task monitoring subroutine, the CPU171 monitors the second paper feed cassette 141b not monitored in another cycle consisting of the third to fifth monitoring periods from the end of monitoring of all 5 paper feed cassettes 141a to 141e in the fourth monitoring period (S207), and then monitors the third paper feed cassette 141c not monitored in another cycle (S208).

After the fourth non-task monitoring subroutine is finished, if the judgment unit 170a judges that there is a task, the non-task monitoring subroutine is finished and the routine proceeds to a task monitoring subroutine, and if the judgment unit 170a judges that there is no task, the routine proceeds to a fifth monitoring cycle and the fifth non-task monitoring subroutine is executed. During the execution of the fifth non-task monitoring subroutine, the CPU171 monitors the fourth paper feed cassette 141d that has not been monitored in another cycle in the fifth monitoring period (S209), and then monitors the fifth paper feed cassette 141e that has been monitored (monitored in the third non-task monitoring subroutine) (S210).

After the fifth non-task monitoring subroutine is finished, if the judging unit 170a judges that there is a task, the non-task monitoring subroutine is finished and the task monitoring subroutine is entered, and if the judging unit 170a judges that there is no task, the first monitoring cycle is returned and the first non-task monitoring subroutine is executed again.

In other words, it can also be understood that: in the non-task monitoring subroutine, the first to fifth monitoring periods from the start of monitoring of all of the 5 paper feed cassettes 141a to 141e constitute two overlapping loops, and the two overlapping loops constitute a single loop.

< monitoring control flow of task monitoring subroutine >

The following describes a monitoring control flow of the task monitoring subroutine. Fig. 6 is a flowchart showing a monitoring control flow of the task monitoring subroutine.

In the present invention, when the machine is in the task (S06), the CPU171 repeatedly executes a task monitoring subroutine of: the monitoring main program includes a task monitoring subroutine in which 2 paper feed cassettes including at least one paper feed cassette not monitored in the loop are monitored for one monitoring period.

Fig. 6 illustrates a case where the first paper feed cassette 141a is in a used state, and in a case where another paper feed cassette is in a used state, the first paper feed cassette in fig. 6 may be adjusted to a paper feed cassette in another used state. The above cycle can be understood as the period from the first monitoring period to the fourth monitoring period in fig. 6, but it may be adjusted according to specific needs. If the determination unit 170a determines that the task is completed during the execution of the task monitoring subroutine, in other words, if the determination result of the determination unit 170a is that the task executed by the machine in the previous monitoring period is completed, the task monitoring subroutine is terminated and the non-task monitoring subroutine is entered.

Specifically, as shown in fig. 6, during the execution of the task monitoring subroutine, a first monitoring cycle is started, the first task monitoring subroutine is executed for the first time, and the CPU171 monitors the first paper feed cassette 141a in the use state that is not monitored in the first monitoring cycle (S301), and then monitors the second paper feed cassette 141b that is not monitored (S302).

After the first task monitoring subroutine is finished, if the judging unit 170a judges that the task is finished, the task monitoring subroutine is finished and the process goes to the non-task monitoring subroutine, and if the judging unit 170a judges that the task is in progress, the process goes to the second monitoring period and the second task monitoring subroutine is executed. During the execution of the second task monitoring subroutine, the CPU171 again monitors the first paper feed cassette 141a in the monitored in-use state in the second monitoring period (S303), and then monitors the third paper feed cassette 141c that is not monitored (S304).

After the second task monitoring subroutine is finished, if the determination unit 170a determines that the task is finished, the task monitoring subroutine is finished and the process proceeds to the non-task monitoring subroutine, and if the determination unit 170a determines that the task is in progress, the process proceeds to a third monitoring period and the third task monitoring subroutine is executed. During the execution of the third job monitoring subroutine, the CPU171 again monitors the first paper feed cassette 141a in the monitored in-use state in the third monitoring period (S305), and then monitors the fourth paper feed cassette 141d which is not monitored (S306).

After the third task monitoring subroutine is finished, if the determination unit 170a determines that the task is finished, the task monitoring subroutine is finished and the routine proceeds to the non-task monitoring subroutine, and if the determination unit 170a determines that the task is in progress, the routine proceeds to a fourth monitoring period and the fourth task monitoring subroutine is executed. During execution of the fourth task monitoring subroutine, the CPU171 again monitors the first paper feed cassette 141a in the monitored in-use state in the fourth monitoring period (S307), and then monitors the fifth paper feed cassette 141e which is not monitored (S308).

After the fourth task monitoring subroutine is finished, if the judging unit 170a judges that the task is finished, the task monitoring subroutine is finished and the non-task monitoring subroutine is entered, and if the judging unit 170a judges that the task is in progress, the monitoring unit returns to the first monitoring cycle and executes the first task monitoring subroutine again.

In other words, it can also be understood that: in the task monitoring subroutine, the first to fourth monitoring periods up to the end of monitoring of all 5 paper feed cassettes 141a to 141e constitute one cycle, and when a task is not ended, the cycle is repeated so that the paper feed cassette in use is monitored first in each task monitoring subroutine, that is, the optional device in use is included in the monitoring target, and when the task is ended, the monitoring target exits from the cycle and enters the non-task monitoring subroutine.

< determination flow of whether paper feed cassette is in use >

The flow of determination as to whether or not the paper feed cassette is in use will be described below. Fig. 7 is a flowchart showing a flow of determination as to whether or not the paper feed cassette is in use.

In the determination process of whether or not the paper feed cassette is in use, first, the determination portion 170a determines whether or not the first paper feed cassette 141a is in use (S401), and when the determination result is that the first paper feed cassette 141a is in use, each task monitoring subroutine first monitors the first paper feed cassette 141a in use. When the determination result shows that the first paper feed cassette 141a is not in use, it is determined whether or not the second paper feed cassette 141a is in use (S402).

When the determination result in step S402 is that the second paper feed cassette 141b is in use, the task monitoring subroutines first monitor the second paper feed cassette 141b in use. When the determination result shows that the second paper feed cassette 141b is not in use, it is determined whether or not the third paper feed cassette 141c is in use (S403).

When the determination result in step S403 is that the third paper feed cassette 141c is in use, the task monitoring subroutines first monitor the third paper feed cassette 141c in use. When the determination result shows that the third paper feed cassette 141c is not in use, it is determined whether or not the fourth paper feed cassette 141d is in use (S404).

When the determination result in step S404 is that the fourth paper feed cassette 141d is in use, the task monitoring subroutines first monitor the fourth paper feed cassette 141d in use. When the fourth paper feed cassette 141d is not in use as a result of the determination, it is determined whether or not the fifth paper feed cassette 141e is in use (S405).

When the fifth paper feed cassette 141e is in use as a result of the determination in step S405, the fifth paper feed cassette 141e in use is first monitored in each task monitoring subroutine. If the fifth paper feed cassette 141e is not in use as a result of the determination, the process returns to step S405, and it is determined again whether or not the first paper feed cassette 141a is in use.

The effects of the present invention will be explained below.

In the conventional image forming apparatus, when a plurality of paper feed cassettes are mounted, the control section of the image forming apparatus needs to communicate with each paper feed cassette to monitor the state thereof, and since the processing capability of the CPU of the control section is limited and the communication time required for each paper feed cassette is the same, the paper feed cassettes that can be processed in a predetermined control cycle are constant. In addition, in order to keep the communication load with each paper feed cassette within a certain range, the CPU of the control unit has to be monitored for the utilization rate, however, the CPU monitoring requires further processing capability of the CPU itself, for example, a higher circuit requirement is imposed on the circuit board, and therefore, the CPU having more excellent performance and higher price has to be selected, and the cost thereof increases. Meanwhile, the monitoring of the utilization rate of the CPU occupies a part of the processing capacity of the CPU, which causes a waste of computational resources.

In contrast, in the present invention, in the monitoring subroutine, the CPU monitors 2 paper feed cassettes including at least one paper feed cassette not monitored in the cycle in one monitoring period, and therefore even when 5 paper feed cassettes are mounted on the machine main body, it is possible to communicate information of the paper feed cassettes with the machine main body in real time without being limited by the processing capability of the CPU. This reduces the load on the CPU and improves the operation efficiency of the entire device. In other words, the monitoring cycle of the CPU is not changed, the monitoring cycle of the present invention is the same as the original monitoring cycle of the CPU, and the number of paper feed cassettes monitored in the same monitoring cycle is reduced, so that the workload of the CPU per unit time is reduced.

In addition, when the number of paper feed cassettes is further increased according to actual needs, for example, when the number of paper feed cassettes is increased to 6 or more, the CPU having the existing performance can be used for coping with the situation without replacing a new CPU having more excellent performance and more expensive price, in other words, the number of paper feed cassettes can be further increased without requiring higher CPU processing capacity. In addition, as the number of the paper supply paper boxes is increased, the times of opening or closing the paper supply paper boxes by workers can be reduced, and manual intervention is reduced.

Further, since it is not necessary to monitor the usage rate of the CPU in real time as in the conventional art, it is possible to avoid waste of calculation resources, and since a mechanism for monitoring the usage rate of the CPU can be omitted, it is possible to simplify the configuration.

In addition, since the original monitoring period of the CPU is not changed, it is possible to prevent other problems such as a decrease in control accuracy due to a simple increase in the period, as compared with a case where the period is simply increased.

In addition, in the invention, the broadcasting mode is not needed to be used, and the switching between the broadcasting mode and the unicast mode is not needed, thereby not only ensuring the information security, but also improving the communication efficiency. In addition, compared with using an asynchronous communication method, the state (operating state, presence or absence of paper, etc.) of the monitored paper feed cassette can be transmitted to the CPU in real time, which not only ensures data consistency but also improves paper feed performance.

In addition, in the invention, the monitoring in the working process of the machine is continuously carried out, so that after the paper of the current paper supply paper box is used, the paper can be switched to other idle paper supply paper boxes immediately without suspending the current task, thereby improving the operation efficiency of the whole machine.

In the above description of the present invention, a case where 5 paper feed cassettes are attached and 2 paper feed cassettes are monitored in one monitoring cycle has been described as an example. However, the number of paper feed cassettes and the number of paper feed cassettes monitored in one monitoring cycle may be changed as appropriate as needed, and for example, the number of paper feed cassettes may be increased to 6, 7, 8, or even more; alternatively, the number of paper feed cassettes may be reduced to 4, 3, or 2.

Specifically, when the number of paper feed cassettes is increased to 6, in the non-job monitoring subroutine, the non-job monitoring subroutine is executed 3 times in 3 monitoring cycles, for example, in the first non-job monitoring subroutine, the CPU monitors the first paper feed cassette not monitored in the first monitoring cycle, and thereafter monitors the second paper feed cassette not monitored; in the second non-job monitoring subroutine, the CPU monitors the unmonitored third paper feed cassette in the second monitoring period, and thereafter monitors the unmonitored fourth paper feed cassette; in the third non-job monitoring subroutine, the CPU monitors the unmonitored fifth paper feed cassette in the third monitoring period, and thereafter monitors the unmonitored sixth paper feed cassette. Thus, during execution of the monitoring main program, the CPU repeatedly executes the monitoring subprogram, that is: in the monitoring subroutine, 2 paper feed cassettes including at least one paper feed cassette not monitored in the cycle are monitored in one monitoring period.

When the number of paper feed cassettes is reduced to 4, the non-task monitoring subroutine may be executed 2 times in 2 monitoring cycles in the non-task monitoring subroutine, for example, in the first non-task monitoring subroutine, the CPU monitors the first paper feed cassette not monitored in the first monitoring cycle and then monitors the second paper feed cassette not monitored; in the second non-job monitoring subroutine, the CPU monitors the unmonitored third paper feed cassette in the second monitoring period, and then monitors the unmonitored fourth paper feed cassette. Thus, during execution of the monitoring main program, the CPU repeatedly executes the monitoring subprogram, that is: in the monitoring subroutine, 2 monitoring periods are included in one cycle until the monitoring of all the 4 paper feed cassettes is completed, and in one monitoring period, 2 paper feed cassettes including at least one paper feed cassette not monitored in the cycle are monitored.

The task monitoring subroutine when the number of paper feed cassettes is changed is similar to the case where the number of paper feed cassettes is 5 in the above description, and the description thereof is omitted here.

In addition, the number of paper feed cassettes monitored in one monitoring cycle can be appropriately changed as follows: assuming that 5 paper feed cassettes are installed, the number of paper feed cassettes monitored in one monitoring period may be reduced to one or increased to 3 or the like based on CPU performance or the like. For example, when the CPU processing capacity is low, the number of paper feed cassettes monitored in one monitoring cycle may be adjusted to one, so that only one paper feed cassette may be monitored in each monitoring cycle, and when the CPU processing capacity is high, the number of paper feed cassettes monitored in one monitoring cycle may be increased to 3, and in this case, the number of monitoring cycles and which 3 paper feed cassettes are monitored each time may be adjusted accordingly (in this case, 2 paper feed cassettes that have not been monitored may be included).

Therefore, in the present invention, the relationship between the number of paper feed cassettes and the number of paper feed cassettes monitored in one monitoring cycle can be summarized as follows: when the number of paper feed cassettes is m and the number of paper feed cassettes monitored in one monitoring cycle is n, the above-described technical effects can be achieved on the premise that the relationship is satisfied where m is an integer of 2 or more and n is an integer of 1 or more and less than m.

The present invention is applicable not only to optional devices for paper feed cassettes but also to optional devices for other post-processing devices such as paper discharge cassettes, paper folding devices, and nailing devices, and can achieve the technical effects described above when other types of optional devices are applied.

As described above, in the present invention, in the monitoring subroutine, the CPU monitors n optional devices including at least one optional device that has not been monitored in one monitoring cycle, and therefore, even when m (for example, 5) optional devices are mounted on the machine main body, the information of the optional devices can be communicated with the machine main body in real time without being limited by the processing capability of the CPU. This reduces the load on the CPU and improves the operation efficiency of the entire device. In other words, the monitoring period of the CPU is not changed, the monitoring period of the present invention is the same as the original monitoring period of the CPU, and the number of optional devices monitored in the same monitoring period is reduced, so that the workload of the CPU per unit time is reduced.

In addition, when the number of optional devices is to be further increased according to actual needs, for example, when the number of optional devices is increased to 6 or more, the CPU with the existing performance can be used for coping without replacing a new CPU with more excellent performance and more expensive price, in other words, the number of optional devices can be further increased without requiring higher CPU processing capacity. In addition, as the number of the optional devices is increased, the times of opening or closing the optional devices by workers can be reduced, and manual intervention is reduced.

Further, since it is not necessary to monitor the usage rate of the CPU in real time as in the conventional art, it is possible to avoid waste of calculation resources, and since a mechanism for monitoring the usage rate of the CPU can be omitted, it is possible to simplify the configuration.

In addition, since the original monitoring period of the CPU is not changed, it is possible to prevent other problems such as a decrease in control accuracy due to a simple increase in the period, as compared with a case where the period is simply increased.

In addition, in the invention, the broadcasting mode is not needed to be used, and the switching between the broadcasting mode and the unicast mode is not needed, thereby not only ensuring the information security, but also improving the communication efficiency. In addition, compared with the asynchronous communication method, the monitored states (the running state, the presence or absence of paper, and the like) of the optional devices can be sent to the CPU in real time, which not only ensures the consistency of data, but also improves the paper feeding performance.

In addition, in the invention, the monitoring in the working process of the machine is continuously carried out, so that after the paper of the current optional device is used, the current optional device can be immediately switched to other idle optional devices without suspending the current task, thereby improving the overall operation efficiency of the machine.

In the present invention, the relationship between the number of optional devices to be monitored and the number of optional devices monitored in one monitoring period can be summarized as follows: when the number of optional devices is m and the number of optional devices to be monitored in one monitoring cycle is n, the above-described technical effects can be achieved on the premise that m is an integer of 2 or more and n is an integer of 1 or more and less than m.

The CPU may determine the m value after acquiring the number of optional devices for the m value, and the m value may be matched with the number of optional devices installed in the machine, or the m value may be manually input by the user or the service person as needed at a later stage, for example, when the number of optional devices is 5, or the user or the service person may change the m value as needed when the user or the service person thinks that all optional devices are not necessary to use, for example, the m value may be set to 3 for 3 optional devices to be used. By setting the value of m, the selectivity of the control mode can be increased, and the degree of freedom of control can be improved.

The CPU can change the N value according to actual needs, for example, the N value may be changed according to the processing capability of the CPU itself, or the N value of the subsequent monitoring subroutine may be changed according to actual needs with respect to the previous monitoring subroutine. By changing the value of n, not only can a control mode which is most suitable for the processing capacity of the CPU be selected, but also other control modes required by a user or maintenance personnel can be selected according to actual needs, so that the selectivity is increased, and the control freedom degree is improved.

In the present invention, the monitoring apparatus further includes a determination unit configured to determine whether or not there is an optional apparatus in use among the m optional apparatuses, and a monitoring target of the monitoring sub-program when there is an optional apparatus in use is different from a monitoring target of the monitoring sub-program when there is no optional apparatus in use. In the case where the determination unit determines that there is an optional device in use, each of the monitoring subroutines includes an optional device in use as a monitoring target. When the determination unit determines that there is no optional device in use, at least a part of the monitoring objects do not overlap among the monitoring subroutines.

Specifically, when the determination unit determines that there is no optional device in use, the non-task monitoring subroutine is executed such that a plurality of monitoring periods until the monitoring of all m optional devices is completed form one cycle (may be a single cycle), and when there is no task, the cycle is repeated so that at least a part of the monitoring target is not repeated, and when there is a task, the routine is exited from the cycle and the task monitoring subroutine is entered.

When the determination unit determines that there is an optional device in use, the task monitoring subroutine is executed such that a plurality of monitoring periods until the monitoring of all m optional devices is completed form a single loop, and when the task is not completed, the loop is repeated so that the optional device in use is first monitored in each task monitoring subroutine, that is, the optional device in use is included in the monitored object, and when the task is completed, the loop is exited from the loop and enters the non-task monitoring subroutine.

In this way, when there is no optional device in use, at least a part of the monitoring target does not overlap between the monitoring subroutines, and thus each optional device can be completely monitored without omission. In the case where there is an optional device in use, since the possibility of occurrence of an abnormality such as paper-out or paper jam in the optional device in use is much higher than that in other optional devices, in each monitoring subroutine, the monitoring object includes the optional device in use, and the optional device in which an abnormality is more likely to occur can be monitored more specifically and more effectively. By combining the two monitoring methods, the monitoring efficiency can be effectively improved.

The present invention is not limited to the above embodiments, and the above embodiments may be freely combined as necessary, and various modifications may be made within a scope including the technical idea of the present invention.

Claims (8)

1. An optional device monitoring device, comprising:

an optional device disposed in a main body of the image forming apparatus;

a sensor which is disposed in correspondence with the optional device and detects a state of the optional device; and

a central processor which communicates with the sensor to monitor the state of the optional device,

the above-mentioned alternative apparatus monitoring device is characterized in that,

there are m each of said optional means and said sensor,

the central processor executes a monitoring main program for monitoring all m selectable devices,

a plurality of monitoring periods are included in one cycle until the monitoring of all m optional devices is finished,

the above-mentioned monitoring main program includes a monitoring sub-program,

in the monitoring subroutine, the central processing unit monitors n optional devices including at least one optional device that has not been monitored in one monitoring period,

wherein m is an integer of 2 or more, n is an integer of 1 or more and less than m,

the optional device monitoring apparatus further includes a determination unit configured to determine whether an optional device in use exists among the m optional devices,

the monitoring object of the monitoring sub program when the optional device in use exists is different from the monitoring object of the monitoring sub program when the optional device in use does not exist,

when the judging section judges that there is an optional device in use,

in each of the monitoring subroutines, the monitoring object includes an optional device in use.

2. The optional device monitoring device of claim 1,

the CPU determines the value of m after acquiring the number of the optional devices.

3. The optional device monitoring device of claim 2,

the central processing unit can change the value of n.

4. The selectable device monitoring device of claim 3,

the central processing unit determines the n value according to the use condition or the processing capacity of the central processing unit.

5. The selectable device monitoring device of claim 2,

the above-mentioned optional means includes at least a paper feed cassette.

6. The selectable device monitoring device of claim 1,

when the judging unit judges that there is no optional device in use,

at least a part of the monitoring objects do not overlap between the monitoring subroutines.

7. An image forming apparatus comprising the optional apparatus monitoring apparatus according to any one of claims 1 to 6.

8. A method for monitoring an optional device monitoring device according to any one of claims 1 to 6, comprising:

executing a monitoring main program for monitoring all m optional devices; and

a step of including a plurality of monitoring periods in one cycle until monitoring of all m optional devices is completed, and including a monitoring subroutine in the monitoring main routine, wherein the monitoring subroutine monitors n optional devices including at least one optional device that has not been monitored in one monitoring period,

wherein m is an integer of 2 or more, and n is an integer of 1 or more and less than m.

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