JP2004249597A - Inkjet printer and method for detecting waste ink amount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To elongate life and save power of a waste ink detector for detecting whether or not a waste liquid tray is full in an inkjet printer which can collect ink liquid droplets discharged from an inkjet head by the waste liquid tray disposed at the rear face side of a platen. <P>SOLUTION: When a marginless printing mode is designated (step ST1), a control part 31 of the inkjet printer 1 energizes the waste ink detector 17 set at the waste liquid tray 5 disposed at the platen rear face side to switch the detector to an operation state (step ST2). It is detected on the basis of an output of the detector 17 whether or not the waste liquid tray 5 becomes full (step ST4). When printing by the marginless printing mode finishes (step ST5), the waste ink detector 7 is brought back again to a non operation state (step ST6). Since the waste ink detector 17 is operated only when it is necessary, the life of the waste ink detector 17 is elongated and and the power of it is saved. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet printer in which a waste ink collecting unit for collecting ink droplets ejected from an ink jet head to a platen is arranged on the back side of a platen defining a printing position by an ink jet head. . More specifically, the present invention relates to an ink jet printer provided with a detecting means for detecting that a waste ink collecting section is full with waste ink.
[0002]
[Prior art]
2. Description of the Related Art As an ink jet printer, there is known an ink jet printer capable of performing printing in a printing mode in which printing is performed by designating a printing area wider than a recording medium to be printed. In this print mode, a print area wider than the recording paper conveyed along the platen is designated, print data corresponding to the print area is created, and printing is performed. Such a print mode is called, for example, a borderless print mode, and is used when it is desired to perform a predetermined print without leaving a margin on the outer peripheral portion of the recording paper.
[0003]
In this printing mode, ink droplets are also ejected from the inkjet head in the outer portions of the front and rear edges or right and left edges of the recording paper. Ink droplets ejected at such positions land directly on the platen. The platen surface portion on which the ink droplet lands is formed in a concave shape so that the ink droplet lands on the platen surface does not adhere to recording paper or the like being conveyed. Also, a large number of through holes are formed in the portion, so that the ink droplets are guided to the platen rear side. Further, a waste liquid tray (waste ink recovery unit) is disposed on the rear side of the platen, and ink droplets guided to the rear side of the platen are collected on the waste liquid tray. The waste liquid tray includes an ink absorber and a tray containing the ink absorber, and is detachably attached to the inkjet printer.
[0004]
Here, the ink jet printer having the waste liquid tray is provided with a detecting unit for detecting that the waste liquid tray is full of the waste ink. As the detection means, there is generally known a detection means which counts the number of ejections of ink droplets in a printing operation in the borderless printing mode, and detects that the waste liquid tray is full based on the integrated value. However, in this method, a large margin needs to be taken because the detection error is large. For this reason, it is often detected that the waste liquid tray is full before the waste liquid tray is full, which is uneconomical.
[0005]
Therefore, a waste ink detector consisting of an electrode as described in the following patent document is attached to the ink absorber of the waste liquid tray, and based on the output of the waste ink detector, it is determined whether or not the waste liquid tray is full. It is conceivable to adopt a detection method.
[0006]
[Patent Document]
Japanese Patent Publication No. 6-32925
[Problems to be solved by the invention]
An object of the present invention is to provide an ink jet printer that detects whether or not a waste liquid tray is full based on an output of a waste ink detector attached to a waste ink recovery unit, to extend the life of the waste ink detector and to save power. To achieve.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an inkjet head, a platen opposed to the inkjet head for defining a printing position of the inkjet head, and an ink droplet ejected toward the platen. An ink jet printer comprising: a waste ink recovery unit disposed on the back side of the platen for recovering the waste ink; and detection means for detecting that the waste ink recovered by the waste ink recovery unit has reached a predetermined amount. , The detection means includes a waste ink detector attached to the waste ink recovery unit, and a switching means for switching the waste ink detector between an operation state and a non-operation state, wherein the switching means is determined in advance. The waste ink detector is switched to the operating state only during the set period.
[0009]
According to the present invention, the waste ink detector attached to the waste ink recovery unit can be turned on by supplying power only in an operation state in which ink droplets ejected from the inkjet head are recovered by the waste ink recovery unit. it can. For example, in a print mode in which printing is performed by designating a print area wider than the recording medium to be printed, the print mode is switched to the ON state only during a period in which printing is performed. In this way, the waste ink detector is switched to the operating state only in the operation state in which it is necessary to detect whether the waste ink recovery unit is full, and the detection of whether the waste ink recovery unit is full is performed. Is performed. Therefore, compared to the conventional waste ink detector that is energized in conjunction with the on / off operation of the ink jet printer, the waste ink detector is switched to the operating state only during the period when the detection operation is required. A longer life can be achieved, and wasteful power consumption can be suppressed.
[0010]
On the other hand, the present invention relates to an inkjet apparatus for detecting whether or not a waste ink recovery unit disposed on the back side of the platen is full in order to collect ink droplets ejected on a platen disposed opposite to an inkjet head. In the method for detecting a waste ink amount of a printer, when the inkjet printer is in a predetermined specific operation mode, a detector ON step of switching a waste ink detector attached to the waste ink recovery unit from a non-operation state to an operation state; A determining step of determining whether or not the waste ink collecting unit is full based on an output of the waste ink detector; and, when the ink jet printer is not in the specific operation mode, turning off the waste ink detector. Switching off the detector to the operating state.
[0011]
In the method of the present invention, the waste ink detector is switched to the operation state only when the inkjet printer is in a specific operation mode. Therefore, only in the operation mode in which the ink droplets ejected from the inkjet head are collected in the waste ink collection unit, for example, in the print mode in which printing is performed by specifying a print area wider than the recording medium to be printed, Can be turned on. Therefore, according to the method of the present invention, the waste ink detector is turned on only when necessary, that is, when it is necessary to detect whether or not the waste ink recovery unit is full. A longer life can be achieved, and power saving can be achieved.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an inkjet printer to which the present invention is applied will be described with reference to the drawings.
[0013]
FIG. 1 is a perspective view showing an internal structure of the ink jet printer according to the present embodiment, and FIG. 2 is a perspective view showing a state where a waste liquid tray is pulled out. The illustrated ink-jet printer 1 includes an ink-jet head 3 mounted on a head carriage 2 in a downward direction, a platen 4 for defining a printing position by the ink-jet head 3, and a back side (lower side in the figure) of the platen 4. And a waste liquid tray 5 disposed therein. The inkjet head 3 is reciprocated by the head carriage 2 in the print width direction X. The inkjet head 3 is driven and controlled by a control circuit (not shown) via the flexible wiring board 6. Further, ink is supplied from an ink cartridge 9 removably mounted on a cartridge mounting portion 8 mounted on the printer frame 7.
[0014]
The platen 4 has a size including the maximum print width of the inkjet head 3, and has a downwardly curved portion extending in the print width direction X at a portion facing a nozzle (not shown) of the inkjet head 3. A recess 11 is formed. A large number of through holes 12 are formed in the recess 11 at regular intervals along the printing width direction. The waste liquid tray 5 has a width including the platen 4, and includes a flat tray body 13 having an open upper side, and an ink absorber 14 housed in the tray body 13. The ink absorber 14 is a sponge or a felt.
[0015]
The waste liquid tray 5 is detachably mounted on a tray mounting portion 15 formed on the printer frame 7. In this example, as shown in FIG. 2, the tray can be detached from the tray mounting portion 15 by pulling it forward, and can be mounted on the tray mounting portion 15 by pushing it backward.
[0016]
Here, a waste ink detector 17 having a pair of electrodes 16a and 16b is attached to a side surface of the waste liquid tray 5 in the tray body 13. The electrodes 16a, 16b are inserted inside the ink absorber 14. In the case of the ink absorber 14 in which the waste ink is not absorbed at all, the resistance between the electrodes is infinite, and when the waste ink is absorbed, the resistance between the electrodes gradually decreases. Therefore, if the mounting position of the electrode is appropriately set, it is possible to detect whether or not the waste liquid tray 5 is full based on the resistance between the electrodes.
[0017]
Next, on the side of the platen 4 in the printing width direction, a head maintenance unit 21 is disposed at a position outside the printing range of the inkjet head 3. The head maintenance unit 21 includes a head cap 22 for capping the nozzle surface of the inkjet head. During printing standby, the ink jet head 3 returns to the home position facing the head cap 22, and its ink nozzle surface is covered by the head cap 22 to increase the viscosity of the ink remaining in the ink nozzles and the ink nozzle. This prevents foreign matter such as paper powder from entering the paper. In addition, ink droplets are ejected from the inkjet head 3 to the head cap 22 regardless of printing, and the thickened ink is discharged from the ink nozzles to prevent clogging of the ink nozzles. Further, a waste ink recovery pump 23 is provided to suck ink from the ink nozzles to prevent clogging of the ink nozzles.
[0018]
The waste ink collected from the inkjet head 3 by such head cleaning is collected in, for example, the ink cartridge 9. A waste ink recovery tank is formed inside the ink cartridge 9, and the waste ink sucked by the waste ink recovery pump 23 is recovered in the waste ink recovery tank of the ink cartridge 9.
[0019]
FIG. 3 is a schematic block diagram showing a control system of the inkjet printer 1 together with an ink supply / collection system. The outline of the operation of the inkjet printer 1 will be described with reference to FIG.
[0020]
First, the control system of the ink jet printer 1 includes a control unit 31 mainly composed of a microcomputer including a CPU, a ROM, a RAM, and the like. The control unit 31 receives print commands, print data, and the like from a host device 32. Supplied. In the printing operation, the recording paper P is conveyed at a predetermined speed in a direction perpendicular to the printing width direction X through the space between the ink jet head 3 and the platen 4, and in synchronization with this, the ink jet head 3 is moved in the printing width direction X. The ink droplets are ejected onto the surface of the recording paper P while being reciprocated. The ink cartridge 9 stores, for example, inks of respective colors of black, cyan, magenta, and yellow, and these inks are supplied to the inkjet head 3 via the ink supply path 33.
[0021]
In this example, it is possible to perform printing in a printing mode (hereinafter, referred to as a borderless printing mode) in which printing is performed by designating a printing area wider than the recording paper P to be printed. Is performed under the control of the control unit 31 based on, for example, a command from the host device 32. In the printing operation in the borderless printing mode, ink droplets are ejected from the ink jet head 3 even at positions deviated from the front and rear edges or the left and right edges of the recording paper P. The ejected ink droplets are collected in the waste liquid tray 5 on the back side through the through holes 12 formed in the concave portions 11 of the platen 4.
[0022]
In a printing standby state or the like, the inkjet head 3 is waiting at a home position outside the printing range. In addition, even during printing, the ink jet head 3 returns to the home position at predetermined intervals, and head cleaning for eliminating clogging of the ink nozzles is performed. Ink droplets ejected from the inkjet head 3 during head cleaning are collected by the waste ink recovery pump 23 from the head cap 22 via the waste ink recovery path 34 into the waste ink recovery tank 9a of the ink cartridge 9.
[0023]
(Waste ink amount detection operation of waste liquid tray)
Next, FIG. 4 is a schematic flowchart mainly showing an operation for detecting whether or not the waste liquid tray 5 is full by the inkjet printer 1. Referring to this figure, when the borderless printing mode is designated by the device 32 (step ST1), the control unit 31 supplies power to the waste ink detector 17 attached to the waste liquid tray 5 to thereby control the waste ink. The detector 17 is switched to the operating state (step ST2: detector ON step). Thereafter, printing in the borderless printing mode is executed (step ST3).
[0024]
Here, during printing in the borderless printing mode, whether or not the waste liquid tray 5 is full is periodically determined based on the output of the waste ink detector 17 (step ST4: determination step). In an actual operation, such a determination operation is periodically executed as an interrupt process. If it is detected that the battery is full, the fact is notified via an output device such as the display 33, and the printing operation is temporarily stopped (step ST1112).
[0025]
When printing in the borderless printing mode is completed (step ST5), the power supply to the waste ink detector 17 is stopped, the waste ink detector 17 is returned to the non-operation state (step ST6: detector off step), and printing is completed. I do.
[0026]
In the printing modes other than the borderless printing mode, the waste ink detector 17 is kept in the non-driving state. That is, printing is performed without switching the waste ink detector 17 to the operating state (steps ST1, ST21, ST22).
[0027]
As described above, in the inkjet printer 1, a detection unit for detecting whether the waste liquid tray 5 is full by the control unit 31 and the waste ink detector 17 is configured. Further, the control unit 31 functions as a switching unit for switching the waste ink detector 17 between an operation state and a non-operation state, and determines whether or not the waste liquid tray 5 is full only when printing is performed in the borderless print mode. I try to detect. Therefore, the waste ink detector 17 is switched to the operating state only in the printing state in the borderless printing mode. Therefore, since the waste ink detector 17 is energized and used only when necessary, it is possible to achieve a longer life and power saving as compared with a case where the energization is always performed.
[0028]
(Other embodiments)
In the above-mentioned ink jet printer 1, a configuration using a pair of electrodes 16a and 16b is adopted as the waste ink detector 17. Of course, other types of waste ink detectors can be used. For example, an optical detector using a prism reflecting surface can be used.
[0029]
Further, the waste ink detector may be switched to the operating state in an operating state other than the borderless printing mode, and whether or not the waste liquid tray is full may be detected based on the output. For example, in a state where the recording paper is not conveyed, an operation of driving the inkjet head in the printing area to eject ink droplets not involved in printing from each ink nozzle to perform clogging of the ink nozzle may be performed. Conceivable. In such an operation, the waste ink is collected in the waste liquid tray. Therefore, it is necessary to switch the waste ink detector to the operating state and detect the amount of waste ink in the waste liquid tray.
[0030]
Further, in the above example, whether or not the waste liquid tray is full is detected. However, the amount of waste ink collected in the waste liquid tray other than the full state may be detected.
[0031]
【The invention's effect】
As described above, according to the present invention, in an ink jet printer capable of collecting ink droplets ejected from an ink jet head by a waste ink collecting unit disposed on the back side of a platen, the waste ink attached to the waste ink collecting unit The detector is switched from the non-operation state to the operation state only in the operation state of the ink jet printer in which the waste ink is collected in the waste ink collection section. Therefore, as compared with the conventional detection mechanism which always keeps the waste ink detector in the operating state, it is possible to achieve a longer life and a lower power consumption of the waste ink detector.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the internal structure of an ink jet printer to which the present invention has been applied.
FIG. 2 is a perspective view showing the internal structure of the ink jet printer of FIG. 1, showing a state in which a waste liquid tray is pulled out.
FIG. 3 is a schematic block diagram showing a control system in the ink jet printer of FIG. 1 together with an ink supply / recovery system.
FIG. 4 is a schematic flowchart showing an operation of detecting whether or not a waste liquid tray is full by the inkjet printer of FIG. 1;
[Explanation of symbols]
Reference Signs List 1 inkjet printer, 2 head carriage, 3 inkjet head, 4 platen, 5 waste liquid tray, 7 device frame, 8 cartridge mounting portion, 9 ink cartridge, 11 concave portion, 12 through hole, 15 tray mounting portion, 16a, 16b electrode, 17 Waste ink detector, 22 head cap, 31 control unit, 32

Claims (4)

An ink-jet head, a platen opposed to the ink-jet head for defining a printing position of the ink-jet head, and a rear side of the platen for collecting ink droplets ejected toward the platen. A waste ink collecting unit, and an ink jet printer having a detecting unit for detecting that the waste ink collected by the waste ink collecting unit has reached a predetermined amount.
The detection unit includes a waste ink detector attached to the waste ink recovery unit, and a switching unit that switches the waste ink detector to an operation state and a non-operation state,
The inkjet printer according to claim 1, wherein the switching unit switches the waste ink detector to an operation state only during a predetermined period. In claim 1,
The inkjet printer according to claim 1, wherein the predetermined period is a period in which printing is performed in a print mode in which printing is performed by designating a print area wider than a recording medium to be printed. Waste ink amount detection of an inkjet printer for detecting whether or not a waste ink recovery unit disposed on the back side of the platen is full in order to collect ink droplets ejected on a platen opposed to an inkjet head In the method,
When the inkjet printer enters a predetermined specific operation mode, a detector ON step of switching a waste ink detector attached to the waste ink recovery unit from an inactive state to an active state,
A determining step of determining whether the waste ink collecting unit is full based on an output of the waste ink detector;
A detector off step of switching the waste ink detector to a non-operational state when the inkjet printer is not in the specific operation mode;
And a method for detecting a waste ink amount of an ink jet printer. In claim 3,
The waste ink amount detection method for an ink jet printer, wherein the specific operation mode is a print mode in which printing is performed by designating a print area wider than a recording medium to be printed.

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