Image forming apparatus, waste liquid tank accommodation error determination method, waste liquid tank accommodation error determination device, and waste liquid tank accommodation error determination program

Abstract

To provide an image forming apparatus capable of determining whether or not waste liquid ink is appropriately stored in a waste liquid tank.SOLUTION: An image forming apparatus 100 includes a head 33 for ejecting ink toward a recording medium, a detection means 13 for detecting an increase amount of waste liquid ink in a waste liquid tank 41 for storing the waste liquid ink from the head 33, and a detection means 14 for detecting a storage error of the waste liquid tank 41 for storing the waste liquid ink based on a detection result by the detection means 13.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that fixes ink onto a recording medium, a method for determining a storage error in a waste liquid tank, a device for determining a storage error in a waste liquid tank, and a program for determining a storage error in a waste liquid tank. [Background technology]

[0002] Inkjet printing devices are equipped with inkjet heads for generating images. Air bubbles can occasionally get trapped in the head, causing ink to be ejected improperly from the nozzles with trapped air bubbles, resulting in vertical streaks on the printed output. To prevent such poor print results, inkjet printing devices perform head maintenance to supply ink to the head and expel air bubbles from the head. The ink consumed and expelled during head maintenance is collected in a waste tank. When the waste tank becomes full, the user replaces it with an empty one. A weight sensor is installed at the bottom of the waste tank, which notifies the user when it detects that it is full.

[0003] For example, a conventional image forming apparatus includes a waste liquid tank, a first waste liquid tank detection sensor, a second waste liquid tank detection sensor, and a waste liquid counting unit (see Patent Document 1). The waste liquid tank recovers ink from an ink receiving member. The first waste liquid tank detection sensor determines whether the waste liquid tank is installed in a predetermined position. The second waste liquid tank detection sensor determines whether the amount of waste liquid exceeds a predetermined threshold for a certain period of time. The waste liquid counting unit counts the amount of waste liquid discharged into the ink receiving member.

[0004] In this image forming apparatus, when the waste liquid tank is removed and reinstalled, the first waste liquid tank detection sensor recognizes that the waste liquid tank has been reinstalled. Then, in the image forming apparatus, the second waste liquid tank detection sensor recognizes that the waste liquid has run out when the amount of waste liquid falls below a threshold. Furthermore, in the image forming apparatus, the amount of waste liquid accumulated in the waste liquid counter is reset based on the above-mentioned recognition. This image forming apparatus can calculate the amount of waste liquid discharged and periodically check the weight of the waste liquid tank. Therefore, if the image forming apparatus does not detect an increase in the amount of waste liquid for a certain period of time, it can warn of a malfunction of the sensor in the waste liquid tank or a warning to remove the lid of the waste liquid tank.

[0005] Another example of a conventional image forming apparatus is known to have the following configuration: The image forming apparatus is provided with a suction pump that sucks up waste ink, a waste ink tank that collects waste ink, a waste ink volume accumulation counter, and a memory element that can read and write the accumulated waste ink count value in the waste ink tank (see Patent Document 2). In this image forming apparatus, the accumulated waste ink count value is recorded in the memory element, making it possible to immediately grasp the amount of waste ink that has been discarded in the waste ink cartridge. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2023-112881 [Patent Document 2] Japanese Patent Publication No. 2020-029065 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the image forming apparatus described in Patent Document 1, if the second waste liquid tank detection sensor for determining whether the amount of waste liquid exceeds a threshold value breaks down, the amount of waste ink cannot be determined. As a result, it becomes unclear whether the waste ink in the waste liquid tank is being properly stored. Also, in the image forming apparatus described in Patent Document 2, if the waste liquid amount accumulating counter breaks down, it becomes unclear whether the amount of waste ink in the waste liquid tank can be accumulated. As a result, the amount of waste ink cannot be properly recorded, and it becomes unclear whether the waste ink tank is properly storing the waste ink. Furthermore, the inside of the printing device could become dirty due to ink overflowing when the waste liquid tank lid was removed, improper installation of the ink tank, or damage to the ink tank, which required a great deal of effort to clean the inside of the printing device.

[0008] The present invention has been made in consideration of the above-mentioned problems, and has as its object to provide an image forming apparatus, a method for determining a storage error in a waste liquid tank, a device for determining a storage error in a waste liquid tank, and a program for determining a storage error in a waste liquid tank, which can determine whether waste ink is properly stored in the waste liquid tank. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention has the following configuration. (1) An image forming apparatus comprising: a head that ejects ink toward a recording medium; a detection means that detects an increase in the amount of waste ink in a waste liquid tank that stores waste ink from the head; and a detection means that detects a storage error in the waste liquid tank that stores the waste ink based on the detection results by the detection means.

[0010] (2) An image forming apparatus as described in claim 1, further comprising a waste ink amount accumulating means for measuring the amount of waste ink discharged outside the head, and the detecting means detects a storage error in the waste ink tank based on the amount of waste ink measured by the waste ink amount accumulating means and the increase in the amount of waste ink detected by the detecting means.

[0011] (3) An image forming apparatus as described in claim 2, wherein the detection means detects a storage error in the waste ink tank when the increase detected by the detection means is less than the increase estimated from the amount of waste ink calculated by the waste ink amount accumulating means.

[0012] (4) In the image forming apparatus according to claim 2, the waste ink amount accumulating means calculates the amount of waste ink from the actual amount of ink consumed by an ink sensor, a predetermined value calculated in advance, and the number of times the ink supply pump is operated.

[0013] (5) The image forming apparatus according to claim 2, wherein the detection means is a mechanism for measuring the increased amount of waste ink based on the actual weight measured by a weight sensor that measures the weight of the waste liquid tank, or a mechanism for measuring the height position of the waste liquid tank from multiple status sensors and measuring the weight of the waste liquid tank from the height of the waste liquid tank.

[0014] (6) An image forming apparatus as described in claim 5, further comprising a waste liquid tank installation sensor for detecting whether or not the waste liquid tank is installed, and when the waste liquid tank installation sensor detects a state transition from a state in which the waste liquid tank is in the appropriate position for the weight sensor to a state in which the waste liquid tank is not installed, the amount of waste ink accumulated by the waste ink amount accumulating means and the weight measurement start standard of the weight sensor are reset.

[0015] (7) The image forming apparatus according to claim 1, further comprising a maintenance unit for performing maintenance on the head, the maintenance unit being activated when the power is turned on and a user issues an instruction for maintenance on the head from an operation panel.

[0016] (8) The image forming apparatus according to claim 1, wherein a malfunction of the weight sensor of the waste liquid tank, forgetting to remove the cap of the waste liquid tank, or an installation error of the waste liquid tank is displayed on an operation panel.

[0017] (9) The image forming apparatus according to claim 1, wherein the waste liquid tank is removable and replaceable. (10) The image forming apparatus according to claim 7, wherein the head maintenance can be performed by specifying one head or a plurality of heads at once.

[0018] (11) A method for determining a storage error in a waste liquid tank, comprising the steps of: measuring the weight of the waste liquid tank using a weight sensor; calculating an increase in the amount of the waste liquid tank from the measured weight; calculating an estimated cumulative amount of waste ink using a waste ink amount accumulating means; comparing the increase calculated from the weight of the waste liquid tank with the cumulative amount of waste ink; and determining that a storage error has occurred in the waste liquid tank if the increase is less than the cumulative amount in the comparing step.

[0019] (12) A waste ink tank storage error determination device comprising: a calculation means for receiving the weight value of the waste ink tank measured by a weight sensor of the waste ink tank and calculating an increase amount; a detection means for receiving the increase amount calculated by the calculation means; a waste ink amount integrating means for calculating the accumulated amount of waste ink stored in the waste ink tank; and a detection means for comparing the increase amount with the accumulated amount and detecting a storage error in the waste ink tank when the increase amount is less than the accumulated amount. (13) A waste liquid tank storage error determination program for causing a computer to execute a procedure for detecting an increase in the amount of waste liquid in the waste liquid tank and a procedure for determining that a storage error has occurred in the waste liquid tank based on the increase in the amount of waste liquid in the waste liquid tank. [Effects of the Invention]

[0020] According to the present invention, the user can easily determine whether or not the waste ink tank is properly storing the waste ink. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is an explanatory diagram schematically illustrating an overview of an image forming apparatus according to an embodiment of the present invention. [Figure 2] 1 is a block diagram illustrating an image forming apparatus according to an embodiment of the present invention. [Figure 3]FIG. 2 is an exploded perspective view showing the waste liquid tank with the outer lid and inner lid removed. [Figure 4] FIG. 2 is an explanatory diagram illustrating a carriage and a waste ink tank of the image forming apparatus according to the embodiment of the present invention, with some parts omitted. [Figure 5] FIG. 2 is an explanatory diagram schematically illustrating a carriage used in the image forming apparatus according to the embodiment of the present invention. [Figure 6] 2 is an explanatory diagram illustrating a schematic arrangement relationship between a carriage and a waste liquid storage unit of an image forming apparatus according to an embodiment of the present invention; FIG. [Figure 7A] 10 is a graph showing the weight of waste ink in a normal state of the image forming apparatus according to the embodiment of the present invention. [Figure 7B] 10 is a graph showing the weight of waste ink when an abnormality occurs in the image forming apparatus according to the embodiment of the present invention. [Figure 7C] 10 is a graph showing the weight of waste ink when an abnormality occurs in the image forming apparatus according to the embodiment of the present invention. [Figure 8] FIG. 10 is an explanatory diagram showing a flowchart for detecting a storage error in the waste ink tank of the image forming apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. Note that common components in each drawing are designated by the same reference numerals. Furthermore, in each drawing, the dimensions may be exaggerated or reduced to be different from the actual dimensions, or the shapes may be simplified, in order to make the positional relationship of the components easier to understand. Fig. 1 is an explanatory diagram showing a schematic overview of an image forming apparatus 100 according to an embodiment of the present invention, and Fig. 2 is a block diagram showing the image forming apparatus 100 according to an embodiment of the present invention.

[0023] <Image forming device> 1, as an example, image forming apparatus 100 includes a paper feed unit 52, an image forming unit 50, an image reading unit 80, a paper discharge unit 53, a waste liquid storage unit 40, and a control unit 10. This image forming apparatus 100 forms an image on a storage medium such as paper, fabric, plastic film, or glass plate. Note that, as an example, image forming apparatus 100 will be described as forming an image on paper.

[0024] Furthermore, the image forming apparatus 100 not only allows operations such as printing to be performed via the operation panel 21, but also includes a communication unit (not shown) that allows operations such as printing image data via signals from an external personal computer. The communication unit uses various local connection interfaces, such as network interfaces based on standards such as SATA, PCI Express, USB (Universal Serial Bus) (registered trademark), Ethernet (registered trademark), and IEEE1394, and wireless communication interfaces such as Bluetooth (registered trademark) and IEEE802.11. A print job consisting of print data and print settings can be received via the communication unit from an external terminal such as a PC (Personal Computer).

[0025] <Operation panel> 2 is composed of, for example, a touch panel display in which a touch panel is stacked on top of a liquid crystal display. Operation panel 21 includes a touch panel for inputting settings for a job to be performed using image forming apparatus 100, and a liquid crystal display for displaying the contents of operations performed on the touch panel.

[0026] The operation panel 21 is used to input various settings such as printing conditions and the timing for adjusting the formation positions of front and back images, as well as to display the status of the device and input various instructions. The user can also use the operation panel 21 to input paper information for the paper stored in each tray of the paper feed tray. The paper information includes the type of paper 5 (plain paper, fine paper, colored paper, coated paper, pre-printed paper (pre-printed paper), etc.), paper basis weight, thickness, size, etc. The input paper information is stored in the storage means 16 in association with the upper tray, middle tray, and lower tray, or the paper feed device.

[0027] The paper feed tray is, for example, a three-tiered drawer tray consisting of an upper tray, a middle tray, and a lower tray. The upper tray, middle tray, and lower tray are provided with attachment / detachment sensors for detecting the attachment / detachment of each tray. The attachment / detachment states of the upper tray, middle tray, and lower tray are detected by the attachment / detachment sensors, and the detection signals are sent to the control unit 10. The upper tray, middle tray, and lower tray are provided with paper remaining sensors for measuring the amount of paper remaining in each tray. The paper remaining sensors detect the amount of paper remaining in the upper tray, middle tray, and lower tray, and send the detected detection signals to the control unit 10. The paper feed tray is provided in a paper feeder. The paper feeder may be provided with multi-tiered trays. The number of trays is not limited to three, and may be one, four, or more.

[0028] <Paper feed section> The paper feed unit 52 has a paper transport path with multiple transport rollers and a drive motor that drives the transport rollers. The paper feed unit 52 rotates the transport rollers at a predetermined timing by driving the drive motor, and transports paper fed from the paper feed tray to the image forming unit 50. The transport path is also provided with registration rollers that rotate and stop using a clutch to adjust the timing of paper transport. The paper is transported along the transport path and has an image formed on it by the image forming unit 50. Then, it passes through the downstream transport path, undergoes various processes according to the print settings of the print job, and is then placed on the paper output tray via the paper output unit 53.

[0029] Image forming unit The image forming unit 50 is a device that forms an image on paper. Here, as an example, the image forming unit 50 is assumed to be an image forming unit that forms an image by an inkjet method, but is not limited to this and may be, for example, a device that uses another method. The image forming unit 50 is a device that forms an image on paper supplied from a paper supply unit 52. The image forming unit 50 forms an image on paper fed from, for example, an upper tray, a middle tray, or a lower tray. The image forming unit 50 moves the head 33 using a carriage mechanism 60 to form an image on paper fed onto a transport drum 51 using an inkjet method. The image forming unit 50 also includes an ultraviolet irradiation unit that irradiates ultraviolet light. Therefore, after ink is applied to the paper using the inkjet method, the ink is cured by irradiating ultraviolet light from the ultraviolet irradiation unit.

[0030] 2 and 6, the image forming unit 50 includes a sub-ink tank 32 mounted on a carriage 61, and ink of each color is supplied to the sub-ink tank 32 from a large-capacity main ink tank 71 via a tube or the like. The main ink tank 71 includes a black ink tank 71K, a cyan ink tank 71C, a magenta ink tank 71M, and a yellow ink tank 71Y. The sub-ink tank 32 includes a black sub-tank 32K, a cyan sub-tank 32C, a magenta sub-tank 32M, and a yellow sub-tank 32Y. As shown in FIG. 5, the head 33 includes multiple heads 33K, 33C, 33M, and 33Y, one for each color, and printing is performed by moving the carriage 61 on a conveyor belt 62.

[0031] <Image reading unit> The image reading unit 80 is a device that reads images on the front and back of a sheet of paper on the conveying path, and includes a reading unit and a spectrophotometer. The reading unit is equipped with one or two scanners each consisting of a CCD. If the reading unit is equipped with two scanners, it will read both the front and back sides of the paper being conveyed at the same time. If the reading unit is equipped with one scanner, it will read the front side of the paper being conveyed. The image data read by the reading unit is analyzed by the reading control unit. Then, by analyzing the image data, adjustments such as paper position adjustment, color adjustment, and image position adjustment are automatically performed.

[0032] The spectrophotometer is disposed between the opposing units disposed across the conveyance path. The spectrophotometer spectrally measures the color of each color patch of the color evaluation image formed on paper by the image forming unit 50, and acquires colorimetric data such as the spectral reflectance of each wavelength in the visible light range and its neighboring range. The colorimetric data can be output in a color system such as XYZ. Note that the spectrophotometer does not necessarily have to be provided.

[0033] <Paper ejection section> The paper discharge unit 53 is provided on the conveyance path. A tray is provided in the paper discharge unit 53 so that the operator can easily remove the printed paper, and the printed paper is discharged onto the tray.

[0034] <Waste liquid storage section> The waste liquid storage unit 40 is an area that houses the waste liquid tank 41. The waste liquid storage unit 40 includes a weight sensor 42 and a waste ink receiver 45. The waste liquid storage unit 40 is configured to receive waste ink discharged from the ink head into the waste ink receiver 45 located above it and store it in the waste liquid tank 41 via the waste ink receiver 45. The waste liquid storage unit 40 is located below one end of the movement of the head 33, which is moved by the carriage mechanism 60. The waste liquid storage unit 40 is located within the housing of the image forming apparatus 100, and the waste liquid tank 41 can be installed and removed via an opening / closing door. Waste ink is generated during nozzle clogging elimination maintenance, air bubble removal maintenance, and ink introduction maintenance. When waste ink is generated, the carriage mechanism 60 positions the head 33 at the waste ink receiver 45.

[0035] The waste ink receiver 45 receives the waste ink discharged from the head 33 and sends it to the waste ink tank 41. The waste ink receiver 45 has a wide upper opening at the top, and is positioned so that the upper opening is located below the four heads. The waste ink receiver 45 also has a lower opening below an inclined surface that continues from the upper opening. The waste ink tank 41 is positioned so that the tank opening of the waste ink receiver 45 faces the lower opening of the waste ink receiver 45.

[0036] The waste liquid tank 41 is a container that stores waste ink used to form an image on paper. The waste liquid tank 41 is made of, for example, resin. This waste liquid tank includes a tank housing main body 41a that stores waste ink, and a tank opening 41b formed at the top of the tank housing main body 41a. Note that the tank opening 41b is designed to be detachably engaged with, for example, a tank inner lid 41c and a tank cap 41d. The waste liquid tank 41 can be replaced with a new, empty waste liquid tank 41 once a certain amount of waste ink has been stored therein.

[0037] The waste liquid tank 41 is installed in the waste liquid storage unit 40 with the tank cap 41d and tank inner lid 41c, which close the tank opening 41b, removed. The waste liquid tank 41 is preferably translucent or white so that waste ink can be visually confirmed from the outside when stored inside. The waste liquid tank 41 is placed on a mounting base for a weight sensor 42 installed in the waste liquid storage unit 40. The mounting base for the weight sensor 42 is provided with a waste liquid tank installation sensor 43 that reacts when pressed by the bottom surface of the waste liquid tank 41. In other words, when the waste liquid tank 41 is placed in the correct position on the mounting base for the weight sensor 42, the waste liquid tank installation sensor 43 is configured to determine that the waste liquid tank 41 is placed in the correct position. For this reason, the waste liquid tank installation sensor 43 is preferably located at the rear side where it is pressed when the waste liquid tank 41 is pushed all the way in.

[0038] The weight sensor 42 measures the weight of the waste liquid tank 41. The weight of the waste liquid tank 41 measured by the weight sensor 42 is converted into a digital signal and sent to the control unit 10. The weight sensor 42 is capable of measuring general weights, and is preferably a weighing scale capable of measuring in 1g increments. The weight sensor 42 may also be a weight measuring device that quantifies changes in resistance value by using, for example, a strain gauge.

[0039] <Control unit> The control unit 10 is configured by a computer that controls the overall operation of the image forming apparatus 100. The control unit 10 is configured by a computer that controls the overall operation of the image forming apparatus 100. The computer includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an input / output circuit, etc. The CPU, as the control unit 10, reads out a program corresponding to the processing content from the storage means 16, loads it into the RAM, and controls each component of the image forming apparatus 100 in cooperation with the loaded program. The control unit 10 changes the settings of each unit of the image forming apparatus 100 and controls the operation of each unit based on the operation of the operation panel 21 and the received signals sent to the image forming apparatus 100 via the communication unit.

[0040] Here, the control unit 10 is described as including a waste ink tank ink storage determination unit (waste ink tank sink storage determination device) 20 that determines whether or not the waste ink is properly stored in the waste ink tank 41, a maintenance unit 18 that performs maintenance, and a reset unit 17 that performs resetting. Also, a description of control related to image formation that is generally used in the image forming apparatus 100 will be omitted here.

[0041] The waste tank ink storage determination unit 20 includes a calculation means 11, a waste ink amount accumulating means 12, a detection means 13, a sensing means 14, and a storage means 16. The calculation means 11 calculates the increased amount of waste ink from the weight value sent from the weight sensor 42. The calculation means 11 calculates the latest increased amount of waste ink from the weight value from the weight sensor 42 and the previous weight value of the waste ink tank 41 stored in the storage means 16. The increased amount calculated by the calculation means 11 is sent to the detection means 13.

[0042] The waste ink amount accumulating means 12 calculates the accumulated amount of waste ink from either the actual consumption amount measured by the ink sensor, a predetermined value calculated in advance, or the number of times the ink supply pump has been operated. Here, as an example, a configuration will be described in which the accumulated amount of waste ink is the predetermined value calculated in advance. For ink ejecting heads 33, waste ink is generated when nozzle clogging elimination maintenance (hereinafter referred to as first maintenance), air bubble removal maintenance (hereinafter referred to as second maintenance), and ink introduction maintenance (hereinafter referred to as third maintenance) are performed. During head cleaning maintenance, either or both of the first maintenance and second maintenance are performed.

[0043] Therefore, when a predetermined value is used, the amount of waste ink generated during each maintenance is stored in advance in storage means. When each maintenance occurs, the waste ink amount accumulating means 12 reads and accumulates the amount of waste ink generated during each maintenance operation that has been stored in advance in storage means. For example, when the first maintenance operation occurs, the waste ink amount accumulating means 12 reads the amount of waste ink generated during the first maintenance operation from storage means 16 in response to a signal from maintenance means 18.

[0044] Furthermore, when the waste ink amount accumulating means 12 receives a signal from each maintenance means 18, it counts and stores the number of times the signal has been received according to the type of maintenance. Therefore, the waste ink amount accumulating means 12 receives the amount of waste ink from the storage means 16 and calculates it according to the number of times, thereby accumulating the amount of waste ink. The waste ink amount accumulating means 12 outputs to the detection means 13 the amount of waste ink received from the storage means 16 and the accumulated amount of waste ink calculated from the number of times it has been counted. The actual ink consumption detecting means 34 detects the actual amount of ink consumed and notifies the waste ink amount accumulating means 12. Based on this actual consumption amount, the waste ink amount accumulating means 12 accumulates the amount of waste ink.

[0045] The detecting means 13 compares the increase from the calculating means 11 with the accumulated amount from the waste ink amount accumulating means 12, and detects the difference between them. For example, if the increase in the amount of waste ink is the same as or greater than the accumulated amount of waste ink, the detecting means 13 outputs a positive numerical value to the detecting means 14. On the other hand, if the increase in the amount of waste ink is less than the same as the accumulated amount of waste ink, the detecting means 13 outputs a negative numerical value to the detecting means 14.

[0046] The detection unit 14 receives information from the detection unit 13 and determines whether waste ink is being properly stored in the waste ink tank 41 based on that information. The detection unit 14 has preset criteria. For example, if the received information indicates a positive value, it determines that waste ink is being properly stored in the waste ink tank 41. If the received information indicates a negative value, the detection unit 14 determines that waste ink is not being properly stored in the waste ink tank 41, indicating a storage error. The detection unit 14 then displays information indicating that waste ink is not being stored in the waste ink tank 41 on the operation panel 21 via the output unit 15. Since the detection unit 14 knows that the previously detected waste ink regulation value is not completely accurate, it is preferable to make a determination with a certain margin of error. For example, the detection unit 14 may determine that the waste ink tank 41 is properly storing waste ink even if the information indicates a negative value up to -0.5.

[0047] The output unit 15 outputs information from the detection means 14 to the operation panel 21, and also outputs a signal from the maintenance means 18 to the head 33 to perform maintenance on the head 33 based on the information. When the output unit 15 receives information from the detection means 14, it outputs a signal to the operation panel 21 so that a warning message is displayed on the operation panel 21 using text or sound. For example, the operation panel 21 may display one or all of the following at once, based on the signal from the output unit 15: "Failure of the weight sensor in the waste liquid tank," "Forgotten to remove the cap from the waste liquid tank," or "Waste liquid tank installation error." It is also preferable that the text displayed on the operation panel 21 flash. Furthermore, a warning sound may be emitted from the speaker at the same time.

[0048] When the output unit 15 receives a signal from the power supply 22 via the maintenance means 18, and when the user receives a maintenance instruction from the operation panel 21 via the maintenance means 18, the output unit 15 outputs a signal to the head 33 to perform maintenance on the head 33. When the signal is sent from the output unit 15 to the head 33, the head 33 performs one of the first to third maintenance operations based on the signal.

[0049] The storage means 16 is configured with any of SRAM, DRAM, flash memory, non-volatile semiconductor memory, etc., and stores various data. The storage means 16 is configured to store data input via input means 23 such as a keyboard. The storage means 16 stores, for example, the amount of waste ink generated when each of the first to third maintenance events occurs. The storage means 16 also stores values ​​that serve as reference values ​​when the detection means 14 makes judgments. Furthermore, the storage means 16 exchanges information with the calculation means 11, the waste ink amount accumulating means 12, the detection means 13, and the input means 23.

[0050] The resetting means 17 receives a signal from the waste tank installation sensor 43 and resets the calculating means 11 and the waste ink amount integrating means 12. When a signal is sent to the resetting means 17 from the waste tank installation sensor 43, the resetting means 17 resets the count held by the waste ink amount integrating means 12 to zero. It also resets the weight measurement start standard held by the calculating means 11 from the weight sensor 42. In other words, the signal from the resetting means 17 resets the calculating means 11 so that the increase calculated by the calculating means 11 is calculated as the initial state.

[0051] Next, with reference to Figures 7A to 7C, we will explain specific events that detect when waste ink is not properly stored in the waste ink tank 41. Event A6 shown in Figures 7A to 7C corresponds to the first maintenance (maintenance to unclog nozzles) or the second maintenance (maintenance to remove air bubbles). First, Figure 7A shows the relationship between the increase in waste ink volume and the cumulative amount under normal conditions. In this graph, the vertical axis represents the weight of waste ink, and the horizontal axis represents the events performed by the printing press. For example, waste ink is generated when head maintenance is performed from the time the power is turned on in event A1 until the time the printer is idle in event A2. Thereafter, no waste ink is generated while printing A3, but waste ink is generated when head maintenance is performed during the transition to power-saving mode in event A4, which occurs after printing of event A3 is completed. Furthermore, waste ink is generated from the time the power-saving mode is released in event A5 (i.e., the printer is in an idle state) until head maintenance is performed in event A6. Note that head maintenance may involve either the first maintenance, the second maintenance, or both.

[0052] In this way, the increase in the weight of waste ink in a step-like manner each time an event occurs as shown in Figure 7A indicates a normal state, and indicates that waste ink is being properly stored in the waste ink tank 41. Whether the state is normal as described above or an abnormal state as described below is detected by the detecting means 13 and the detecting means 14 based on information from the weight sensor 42 input to the calculating means 11 and information from the waste ink amount integrating means 12, as shown in FIG. 2.

[0053] On the other hand, as shown in Fig. 7B, after powering on for event A1, a malfunction occurred in weight sensor 42, so the weight of the waste ink does not increase in a single line even when each event occurs. In this way, when the weight of the waste ink does not increase even though waste ink is being generated by each event, this indicates a state in which there is a high possibility that there is an abnormality in weight sensor 42. In such a case, as shown in Fig. 2, detection means 13 and detection means 14 detect an abnormality, a storage error, and this is displayed on operation panel 21.

[0054] 7C, if the weight of the waste ink does not increase at all after the power is turned on in event A1, it is highly likely that the tank cap 41d of the waste ink tank 41 has been left on. Even though waste ink is being sent, because the tank cap 41d is closed, none of the waste ink can be stored in the waste ink tank 41, and no increase in the weight of the waste ink occurs. Even in such a case, as shown in FIG. 2, the detection means 13 and the detection means 14 will detect that the printer is not in a normal state, that there is a storage error, and this will be displayed on the operation panel 21.

[0055] In other words, as shown in FIG. 8, by performing the waste ink tank ink storage determination method, it is possible to always confirm whether waste ink is being stored normally in the waste ink tank 41 or whether a storage error has occurred. The waste ink tank ink storage determination method S10 determines whether waste ink is being stored normally in the waste ink tank 41 by comparing information from the weight sensor 42 with information from the waste ink amount accumulating means when each event occurs. That is, in the method S10 for determining whether an ink storage tank contains waste liquid, the power is turned on (step S11), and various maintenance operations that generate waste ink, such as head maintenance, occur (step S12). Note that the various maintenance operations in step S12 are either nozzle clogging elimination maintenance (first maintenance), air bubble removal maintenance (second maintenance), nozzle clogging elimination maintenance (third maintenance), or head cleaning maintenance (referred to as fourth maintenance).

[0056] Then, the weight sensor 42 measures the weight of the waste ink tank 41 (step S13) and sends it to the calculation means 11. Also, the waste ink amount integrating means 12 selects the integrated amount of waste ink from the storage means 16, calculates the received integrated amount (step S13), and sends it to the detection means 13. Then, the detection means 13 compares the increased amount with the integrated amount (step S14) and detects whether the increased amount is the same as the integrated amount, or whether it is positive or negative. If the values ​​detected by the comparison are the same or positive, the comparison result in step S14 becomes No, indicating that the waste ink is being properly stored in the waste ink tank.

[0057] Furthermore, if the value is negative in step S14, the comparison result in step S14 becomes Yes, and the detection means 14 detects that the waste ink is not properly stored in the waste liquid tank. When the detection means 14 detects (determines) that the waste ink is not properly stored in the waste liquid tank 41, it notifies the operation panel 21 to that effect. Based on the information from the detection means 14, the operation panel 21 displays on the display panel, "Failure of the weight sensor of the waste liquid tank," or "Forgotten to remove the cap of the waste liquid tank," or "Waste liquid tank installation error."

[0058] In this way, the image forming apparatus 100 can detect whether or not the waste ink is properly stored in the waste ink tank 41, so the inside of the apparatus is not soiled with waste ink and the operator is not required to take extra time and effort. The weight of the waste liquid tank 41 may be measured by a status sensor (not shown) disposed in the waste liquid storage unit 40. The status sensor, for example, measures the height position at which the waste liquid tank 41 is placed and measures the weight of the waste liquid tank 41 from that height position. The status sensor may be, for example, an optical sensor, which converts the height into weight when the height of the waste liquid tank 41 is changed from the reference position at which the waste liquid tank 41 is placed by storing waste ink. When a status sensor is used, the height of the mounting base supporting the waste liquid tank 41 needs to be configured to change depending on the weight of the waste liquid tank 41.

[0059] If a status sensor is provided, the calculation means 11 receives information from the status sensor, compares it with data stored in the storage means 16, and calculates the height position of the waste liquid tank 41 according to its weight. For example, if the status sensor is a sensor that detects the height position and the weight sensor 42 is configured to change its height position according to the weight, if the waste liquid tank 41 is not properly filled with waste ink, the height position of the waste liquid tank 41 will not change. Therefore, the calculation means 11 calculates information on the current increased height position of the waste liquid tank 41 from the information on the height position of the waste liquid tank 41 sent from the status sensor and the information on the height position sent previously from the status sensor, and detects the increased amount of waste liquid ink from the information on the increased height position and sends it to the detection means 13.

[0060] In addition, if a status sensor (not shown) is provided, when an increased amount of waste ink calculated based on the height position of the waste tank 41 is sent, the detection means 13 compares the increased amount with the load amount and outputs a positive or negative number to the detection means 14. Furthermore, if the storage means 16 is provided with a status sensor, it stores the amount of increase in waste ink relative to the height position of the waste ink tank 41 that is set in advance.

[0061] The sequence assumed for the method of determining whether the waste tank contains ink may be, for example, as follows. That is, expected sequence 1 includes turning on the power, starting initialization, measuring the weight of the waste liquid, performing maintenance, measuring the weight of the waste liquid, accumulating the weight of the waste ink, determining the adequacy of the amount of waste ink discharged, and completing initialization. Further, the predicted sequence 2 includes an idling state, maintenance execution (user instruction), measurement of the waste liquid weight, accumulation of the waste ink weight, and determination of the adequacy of the amount of waste ink discharged. Furthermore, predicted sequence 3 includes idling state, or power off, head replacement, ink introduction maintenance, waste liquid weight measurement, waste ink volume accumulation, and determination of the adequacy of the amount of waste ink discharged.

[0062] In predicted sequences 1 to 3, when the weight of the waste liquid is measured, the weight is stored in the storage means 16. The validity is determined by the detection means 14. Furthermore, the maintenance to be performed is one of the first to fourth maintenances. The amount of waste ink used during each maintenance has been calculated in advance through experiments.

[0063] The image forming apparatus naturally includes information for printing and programs for executing various procedures. For example, the programs can cause a computer to execute the following procedures: detect whether the middle tray is open or closed during a print job using paper fed from the upper tray; print a front-back position adjustment chart on paper fed from the middle tray using the image forming unit; read the formed front-back position adjustment chart using the reading unit; and adjust the front-back position relative to the middle tray. The image forming apparatus can also operate a computer with programs for causing the computer to function as each of the above-mentioned units. For example, the programs can be a waste liquid tank storage error determination program that causes the computer to execute procedures for detecting an increase in the amount of waste liquid in the waste liquid tank 41 and determining a storage error in the waste liquid tank 41 based on the increase in the amount of waste liquid in the waste liquid tank 41.

[0064] [Variations] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate within the scope of the present invention. For example, although the waste ink amount accumulating means 12 calculates the accumulated amount using a predetermined value, it is also possible to calculate the accumulated amount of waste ink from the actual amount of ink consumed measured by an ink sensor or the number of times the ink supply pump 31 has been operated. Note that the actual amount of ink consumed measured by an ink sensor can be calculated by placing a sensor such as a flow meter between the ink receiving member and the waste ink tank, or between the sub-tank and the head, and measuring the actual amount of ink. [Explanation of symbols]

[0065] 100 Image forming device 10 Control Unit 11 Calculation method 12 Waste ink amount accumulating means 13. Detection Methods 14. Detection methods 15 Output section 16 Memory means 17 Reset Method 18 Maintenance methods 20 Waste tank ink storage determination section 21 Operation panel 22 Power supply 23 Input Methods 31 Ink supply pump 33 head 34 Actual ink consumption detection means 40 Waste liquid storage section 41 Waste liquid tank 42 Weight sensor 43 Waste tank installation sensor 45 Waste ink receiver 50 Image forming unit 51 Transport drum 52 Paper feed section 53 Paper output section 60 Carriage mechanism 61 Carriage 62 Conveyor belt 71 Ink tank 71K black ink tank 71C Cyan Ink Tank 71M magenta ink tank 71Y Yellow Ink Tank 32 Sub ink tank 32K Black Subtank 32C Cyan Subtank 32M Magenta Subtank 32Y Yellow Subtank

Claims

1. a head that ejects ink toward a recording medium; a detection means for detecting an increase in the amount of waste ink in a waste ink tank that stores waste ink from the head; a detecting means for detecting a storage error in the waste ink tank that stores the waste ink based on the detection result by the detecting means; An image forming apparatus comprising:

2. a waste ink amount accumulating means for measuring the amount of waste ink discharged to the outside of the head; the detecting means detects a storage error in the waste ink tank based on the amount of waste ink measured by the waste ink amount integrating means and the increased amount of waste ink detected by the detecting means; 2. The image forming apparatus according to claim 1.

3. When the increase amount detected by the detecting means is equal to or less than the increase amount estimated from the amount of waste ink calculated by the waste ink amount accumulating means, the detecting means detects a storage error in the waste ink tank.

3. The image forming apparatus according to claim 2.

4. the waste ink amount accumulating means calculates the amount of waste ink from an actual amount of ink consumed by an ink sensor, a predetermined value calculated in advance, and the number of times the ink supply pump is operated; The image forming apparatus according to claim 2 .

5. The detection means is a mechanism for measuring the increased amount of waste ink based on the actual weight measured by a weight sensor that measures the weight of the waste tank, or a mechanism for measuring the height position of the waste tank from a plurality of status sensors and measuring the weight of the waste tank based on the height of the waste tank. The image forming apparatus according to claim 2 .

6. a waste liquid tank installation sensor for detecting whether the waste liquid tank is installed; resetting the amount of waste ink accumulated by the waste ink amount accumulating means and the weight measurement start criterion of the weight sensor when the waste ink tank installation sensor detects a state transition from a state in which the waste ink tank is in the appropriate position for the weight sensor to a state in which the waste ink tank is not present; The image forming apparatus according to claim 5 .

7. a maintenance means for performing maintenance on the head; 2. The image forming apparatus according to claim 1, wherein the maintenance unit is activated when the power is turned on and a user issues an instruction for maintenance of the head from an operation panel.

8. 2. The image forming apparatus according to claim 1, wherein a malfunction of the weight sensor of the waste liquid tank, forgetting to remove the cap of the waste liquid tank, or an installation error of the waste liquid tank is displayed on an operation panel.

9. 2. The image forming apparatus according to claim 1, wherein the waste liquid tank is removable and replaceable.

10. 8. The image forming apparatus according to claim 7, wherein the head maintenance can be performed by specifying one head or a plurality of heads at once.

11. measuring the weight of the waste liquid tank with a weight sensor; calculating an increase in the amount of the waste liquid tank from the measured weight; a step of calculating an estimated accumulated amount of waste ink by a waste ink amount accumulating means; a step of comparing the increased amount calculated from the weight of the waste ink tank with the accumulated amount of waste ink; and determining that a storage error has occurred in the waste liquid tank when the increased amount falls below the integrated amount in the comparing step.

12. a calculation means for receiving a weight value of the waste ink tank measured by a weight sensor of the waste ink tank and calculating an increase in the weight value; a detection means for receiving the increase calculated by the calculation means; a waste ink amount accumulating means for calculating an accumulated amount of waste ink stored in the waste ink tank; a detection means for comparing the increased amount with the integrated amount and detecting a storage error in the waste ink tank when the increased amount is smaller than the integrated amount.

13. On the computer, a procedure for detecting an increase in the volume of the waste tank; a waste liquid tank storage error determination program for executing a procedure for determining whether a storage error has occurred in the waste liquid tank based on the increase in the amount of waste liquid in the waste liquid tank;

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