JPH03293153A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To maintain an ink jet recording head constantly in a state where ink is normally discharged by setting an ink discharge amount at the time of head recovery action of an ink jet recording device in accordance with the length of non-use time in which recording operation does not take place and performing the head recovery action efficiently with the discharge of ink. CONSTITUTION:If a power supply switch 37 for an ink jet recording device is turned OFF, MPU 30 sets a timer 31 and resets it when the action to restore use of an ink jet head ends. Next MPU 30 reads the number of count registered by the timer 31 when the power supply for the device is turned ON and transfers the number to a comparison circuit 303. The comparison circuit 303 refers to a mode table 30 stored previously in ROM 302 as it does to a program, if the circuit 303 receives the number of count of the timer 31 which is read by MPU 301. Next the comparison circuit 303 selects an operation mode corresponding to an appropriate elapsing time for the received number of count, and transfers the mode to MPU 301. An ink discharge amount during the head recovery action is determined by this recovery action mode.

Description

[Detailed description of the invention] C Industrial application field] The present invention relates to an inkjet recording device.

[Conventional technology]

As a measure to stabilize the ejection of the inkjet recording head in a conventional inkjet recording apparatus, the ejection surface of the inkjet recording head is capped by a power-off sequence when the power of the inkjet recording apparatus is turned off, and the ejection is stabilized when the inkjet recording head is not in use. A device that prevents foreign matter such as dust from adhering to the surface and ejection port, or a device that forcibly draws a certain amount of ink using suction means or pressure means when the inkjet recording device is powered on.
There is a type of ink that is discharged from an ejection port of an inkjet recording head, and removes foreign matter such as ink that has thickened when the inkjet recording apparatus is not in use, along with the ink.

C Problems to be Solved by the Invention] However, in the conventional technology described above, when capping an inkjet recording head by performing a series of power-off sequences, a relay or the like is used to operate a drive source such as a motor for a certain period of time. This requires a circuit, which complicates the device configuration, and is inconvenient in that the power cannot be turned off until the power-off sequence is completed after the recording operation is completed. Furthermore, in this case, capping the inkjet recording head can prevent dirt and dust from adhering to it, but it does not prevent the ink inside the inkjet recording head from increasing in viscosity. This may cause ink to fail to be ejected.

In addition, if the inkjet recording device is forcibly discharged when the power is turned on, a constant amount of ink is always discharged regardless of the degree of thickening of the ink in the inkjet recording head, which changes depending on the length of time the inkjet recording device is not in use. Because it uses ink, you need to turn on the power frequently,
If the ink is turned off, there is a problem in that not only ink is wasted, but also measures must be taken to prevent staining of the inside of the device due to discharged ink.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and it is an object of the present invention to efficiently perform a head recovery operation by discharging ink to keep an inkjet recording head in a state where it can always discharge normal ink. The purpose of the present invention is to provide an inkjet recording device that can perform the following functions.

[Means to solve the problem]

The present invention provides an inkjet recording apparatus having a controller that discharges ink from the inkjet recording head and performs a head recovery operation of the inkjet recording head when the power is turned on, including a timer that counts the non-use time of the inkjet recording apparatus. , the controller: Corresponding to the non-use time of the inkjet recording device,
a storage unit pre-stored with a mode table in which a recovery operation mode indicating the amount of ink discharged during the head recovery operation is set; and a timer control means for resetting the timer after reading the count number, and searching the mode table based on the count number read by the timer control means and resetting the timer after reading the count number. and a control means for discharging ink from the inkjet recording head in accordance with the recovery operation mode selected by the comparison means.

Further, the timer control means of the controller includes one for resetting a timer at the end of the head recovery operation, and an ink inflow means for forcibly flowing ink into the inkjet recording head and discharging the ink, In the table, a recovery operation mode indicating the amount of ink discharged from the inkjet recording head due to the ink inflow of the ink inflow means is determined corresponding to the non-use time of the inkjet recording apparatus, and the inkjet recording head is Ink is ejected using thermal energy, and some are equipped with an electrothermal converter that provides the thermal energy to the ink.

[Function] When the inkjet recording device of the present invention is powered on, the ink is discharged from the inkjet recording head, and foreign matter that causes ink failure to be ejected, such as thickened ink, in the inkjet recording head is removed from the ink. It performs a head recovery operation that removes the head when it is ejected.
It is possible to count the non-use time during which no printing operation is performed and set the amount of ink discharged during the head recovery operation according to the length of the non-use time. Therefore, when the non-use time is short and the degree of ink thickening is low, the amount of ink discharge can be restricted to suppress ink consumption, and when the non-use time is long and the degree of ink thickening is If it is high, it can be reliably removed by increasing the amount of ink discharged.

As in the second aspect of the present invention, by resetting a timer that counts the non-use time of the inkjet recording device at the end of the head recovery operation, it is possible to avoid the case where the power is turned off again immediately after the power is turned on. However, if the head recovery operation has not been completed, the timer will not be reset and will count the unused time during which no recording operation is being performed since the power was turned off after the previous head recovery operation was completed. Then, when the power is turned on next time, the head recovery operation can be performed with the amount of ink discharged according to the non-use time.

[Example] Next, an example of the present invention will be described with reference to the drawings.

In the inkjet recording apparatus of this embodiment, as shown in FIG. It is connected to a part of the drive belt 4 to be transmitted and is slidably attached to two guide shafts 6a and 6b arranged parallel to each other, and the drive force of the drive motor 5 causes the The inkjet recording head 3 reciprocates over the entire width of a recording medium fed from a medium feeding device (not shown) to a platen 7 disposed opposite to the ejection surface of the inkjet recording head 3. The configuration is such that recording is performed on a recording medium.

The above-mentioned inkjet recording head 3 has four parts having the same configuration.
It consists of two recording heads 3a, 3b, 3c, and 3d, each recording head 3a, 3b.

3c and 3d, as shown in FIG. 2, a plurality of nozzles 1 which are ink ejection ports are provided on the ejection surface facing the recording medium
2 are arranged in parallel, and an electrothermal transducer 13 is provided corresponding to each nozzle 12 to apply ejection energy to the ink within the nozzle 12.

Further, the inkjet recording apparatus of this embodiment is located outside the range of the reciprocating motion of the inkjet recording head 3 during the recording operation, at a position where the inkjet recording head 3 stops during non-recording operation (the left end of the guide shaft 6a in the figure, hereinafter referred to as "
It is called the home position. ), when performing the head recovery operation of the inkjet recording head 3, each recording head 3a, 3b, 3c, 3d of the inkjet recording head 3 is driven by the driving force of the cleaning motor 10 via the transmission mechanism 11. A head recovery device 8 is provided that includes a cap member 8a that caps the ejection surface. This head recovery device 8 includes a cap member 8a for each recording head 3a, 3 during a head recovery operation.
b, 3c.

In connection with the capping of the ejection surface 3d, the ink is forcibly discharged from each nozzle 12 by suctioning the ink by the suction means serving as the ink inflow means, so that the ink can be forcibly discharged from each of the recording heads 3a and 3b.

A head recovery operation such as removing the thickened ink in the nozzles 12 of 3c and 3d is performed. In addition, each recording head 3a, 3b, 3c, 3 by the cap member 8a.
In connection with the capping of the ejection surface of d, the controller described below controls the recording heads 3a, 3b, 3c, 3.
Either the electrothermal transducers 13 of d are driven to perform preliminary ejection of the inkjet recording head 3, or the electrothermal transducers 13 are driven to such an extent that no ink is ejected and the ink is ejected from each of the recording heads 3a, 3b. , 3c, and 3d, a head recovery operation such as reducing the viscosity of the ink in the nozzles 12 is also performed.

Further, on the side surface of the head recovery device 8, a blade 9 as a wiping member made of silicone rubber is held in a cantilever form by a blade holding member 9a.
Like the head recovery device 8, it is operated by a cleaning motor 10 and a transmission mechanism 11, and can engage with the ejection surfaces of each of the recording heads 3a, 3b, 3c, and 3d of the inkjet recording head 3. As a result, after the head recovery operation using the head recovery device 8, the blade 9 is projected into the movement path of the inkjet recording head 3, and as the inkjet recording head 3 moves, each of the recording heads 3a, 3b, 3c3d Wipe off any condensation, moisture, or dust on the discharge surface.

Here, the control system by the controller of this embodiment will be explained with reference to FIG. 3.

FIG. 3 is a block diagram showing the above-mentioned inkjet recording apparatus, and shows a state in which the inkjet recording apparatus is connected to a host device 20, which is an external device.

In the inkjet recording apparatus of this embodiment, the power switch 3
7, power supply voltage from the power supply device 38 is applied, and the controller 30 starts operating. When the power switch 30 is turned on, a message indicating that the power is on is displayed on the panel 32. This panel 32
is for operation, and is equipped with a display means 1 and a switch for recording paper feed, etc., and is connected to the controller 30, and the display means includes operation information such as turning on the power, recording operation, head recovery operation, etc. You can also display the mode.

In this inkjet recording apparatus, the recording operation and the aforementioned head recovery operation are controlled by a controller 30, and the controller 30 controls each recording head 3a, 3b, 3c of the inkjet recording head 3.
, a head drive system sensor 34 that drives the electrothermal transducer 13 of 3d, a mechanical drive system sensor 35 that drives the drive motor 5 and the cleaning motor 10, and a recovery device that drives the suction means of the head recovery device 8. Drive circuit 36
and is connected to. Moreover, this controller 30 is
Document information is received from the host device 20, which is an external device, via the interface circuit 33, and based on the received document information, each of the recording heads 3a, 3b, 3c, and 3d undergoes electrothermal conversion via the head drive system sensor 34. body 1
3 is driven 2 to cause each recording head 3a, 3b, 3c, and 3d to eject ink.

Further, a timer 31 is connected to the controller 30, which is set when the power is turned off by the power switch 37 and reset when the head recovery operation is completed.

Here, the configuration of the controller 30 will be explained with reference to FIG. 4.

The controller 30 of this embodiment includes an MPU 301 and a ROM.
302 and a comparison circuit 303.
U, 301 controls the above-described recording operation and head recovery operation in accordance with a program stored in the ROM 302 in advance. In this embodiment, this program specifies that the head recovery operation is performed when the inkjet recording apparatus is powered on.

Furthermore, the MPU 301 includes the inkjet recording apparatus.
The timer 31 is set when the power switch 37 is turned off, the timer 31 is reset when the head recovery operation ends, and the count of the timer 31 at this time is set when the power switch 37 is turned off. The count is read and transferred to the comparison circuit 303. Therefore, the count number of the timer 31 indicates the non-use time of the inkjet recording apparatus from when the power is turned off to when it is turned on. When the comparator circuit 303 receives the count number of the timer 31 read by the MPU 301, it refers to the mode table 304 shown in Table 1, which is stored in advance in the ROM 302 in the same way as the program, and calculates the elapsed time corresponding to the received count number. The selected operation mode is selected and transferred to the MPU 301.

The above-mentioned mode table 304 indicates that during the head recovery operation,
A recovery operation mode to be executed for the elapsed time is determined, and as shown in Table 1, the recovery operation mode includes a preliminary ejection mode, an ink heating mode, an ink suction mode, and a test pattern depending on the elapsed time. There are print modes or a combination thereof. When the recovery operation mode selected by the comparison circuit 303 is the preliminary ejection mode, the MPU 301 drives the cleaning motor 10 via the mechanical drive system sensor 35, and the inkjet recording head is activated by the cap member 8a of the head recovery device 8. The electrothermal transducer 13 of each of the recording heads 3a, 3b, 3c, and 3d is driven via the head drive system sensor 34 with the ejection surfaces of each of the recording heads 3a, 3b, 3C, and 3d being capped. Ink is ejected a predetermined number of times. Further, when the recovery operation mode is the ink heating mode and preliminary ejection mode, the electrothermal converter 13 is driven for a predetermined period of time via the head drive system sensor 34 to such an extent that ink is not ejected, and the ink is ejected. The ink is heated to lower the viscosity of the ink, and then ink is ejected in the same manner as in the preliminary ejection mode. When the recovery operation mode is the ink suction mode, each of the recording heads 3a and 3b as described above.

With the ejection surfaces 3c and 3d capped, the suction means in the head recovery device 8 is driven via the recovery device drive circuit 36, and ink is sucked a predetermined number of times with a constant suction pressure, thereby discharging each nozzle 12. Perform forced ink discharge from the printer. Furthermore, when the recovery operation mode is the ink suction + test pattern printing mode, after forcibly discharging ink from each recording head 3a, 3b, 3c, and 3d in the same manner as described above, each recording head is 3a
, 3b, 3c, and 3d, and print each recording head 3 along the print data showing a predetermined test pattern.
The electrothermal transducers 13 a, 3b, 3c, and 3d are driven to print the test pattern on the recording medium.

Here, the timing of setting and resetting the timer 3I by the MPU 301 is shown in FIGS. 5(A) and 5(B).
Explain with reference to.

First, as shown in FIG. 5(A), at time t.

When the power switch 37 of the inkjet recording apparatus is turned off, the supply of power supply voltage from the power supply device 38 is stopped, and the logic voltage, which is the operating voltage of the controller 30, begins to fall. Then, at time t2, the logic voltage reaches the threshold level v of the operating voltage of the controller 30.
When TH is reached, the controller 30 stops operating, the timer 3I is set, and the timer 31 starts counting. Thereafter, at time t3, when the power switch 37 of the inkjet recording apparatus is turned on again, the logic voltage starts to rise, and at time t4, when the logic voltage reaches the threshold level T0, the controller 30 is activated. Then, a head recovery operation is performed. When this head recovery operation ends at time t,
At this time, the timer 31 is reset by a signal issued by the MPU 301 indicating the end of the head recovery operation.

Further, if the power switch 37 is turned on and off continuously, and the power switch 37 is turned off at time t6 in the middle of the head recovery operation, as shown in FIG.
Since the PU 301 does not output a signal indicating the end of the head recovery operation, the timer 31 is not reset and continues to count the elapsed time since the power switch 37 was turned off at the aforementioned time t1.

Next, the operation of this embodiment will be explained along the flowchart shown in FIG.

When the recording operation by the inkjet recording apparatus is completed and the power switch 37 is turned off, the supply of power voltage from the power supply device 38 is stopped, and at the same time the operation of the controller 30 is stopped, the timer 31 is set (step 5
01). Thereafter, the timer 31 counts the elapsed time since the power switch 37 turned off the power.

Then, turn on the power switch 3 of the inkjet recording device again.
7 is turned on and the controller 30 is started, the MPU 301 of the controller 30 starts the timer 31 at that time.
The count number of is read (step 502). Based on this read count number, the comparison circuit 3 of the controller 30
03 sequentially searches the mode table 304 and selects a recovery operation mode for the elapsed time corresponding to the count number (steps 503 to 507).
Transfer to 1. At this time, if the read count number indicates, for example, 4 days, "ink heating 10 preliminary ejections N3 times" in step 510 is selected as the recovery operation mode. In this case, as described above, in the controller 30, the MPU 301 drives the head drive system sensor 34 and the mechanical drive system sensor 35 to heat the ink, performs preliminary ejection N3 times, and when these operations are completed. , outputs a signal indicating the end of the head recovery operation and resets the timer 31 (step 514).

This means that the head recovery operation at the time of power-on of the inkjet recording apparatus has been completed, and it is possible to move on to the recording operation.

In this embodiment, when suctioning ink using the suction means during the head recovery operation, the number of suctions with a constant suction pressure was changed depending on the elapsed time since the power was turned off. may be kept the same and the suction pressure may be varied.

Furthermore, the head recovery device may be provided with a pressurizing means in place of the above-mentioned suction means. In this case as well, the same effect can be obtained by changing the number of pressurizations or the pressurizing force depending on the elapsed time.

Furthermore, the inkjet recording head used in this example is composed of four recording heads, and in this case, each recording head is injected with a different color of ink (
For example, by supplying colors (cyan, magenta, yellow, black), it is possible to print a recorded image in color.

The present invention brings about excellent effects particularly in recording heads and recording apparatuses of the bubble jet method proposed by Canon Co., Ltd. among ink jet recording methods.

For typical configurations and principles thereof, see, for example, 0 US Pat. No. 4,723,129, US Pat.
Preferably, the method is carried out using the basic principle disclosed in the specification of No. 6. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. By applying at least one drive signal that corresponds to recorded information and causes a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the electrothermal transducer generates thermal energy, and the recording head This is effective because it causes film boiling on the heat acting surface of the liquid (ink), resulting in the formation of bubbles in the liquid (ink) in one-to-one correspondence with this drive signal. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one drop. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, so that ejection of liquid (ink) with particularly excellent responsiveness can be achieved. This pulse-shaped drive signal is described in U.S. Pat. No. 4,463,359 and U.S. Pat.
Suitable are those described in No. 62 specification. Further, if the conditions described in US Pat. No. 4,313,124 concerning the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be achieved.

The configuration of the recording head includes, in addition to the combined configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. US Pat. No. 4,558,333 and US Pat. No. 4,459,600 disclose a configuration in which the
The structure described in the specification may be used. In addition, Japanese Patent Application Laid-Open No. 1983 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
The present invention is also effective in configurations based on Japanese Patent Application Laid-open No. 138461 of 1982, which discloses a configuration compatible with the open-hole discharge portion that absorbs pressure waves of thermal energy.

In the embodiments of the present invention described above, the ink is described as a liquid, but it may be an ink that solidifies at room temperature or below, but softens or becomes a liquid at room temperature, or an ink that is generally used in inkjet. It may be one that softens or becomes liquid in the temperature range of 30° C. or higher and 70° C. or lower, which is the temperature range for temperature adjustment. That is,
Any ink may be used as long as the ink is in a liquid state when the recording signal is applied. In addition, it is possible to actively prevent temperature rise due to thermal energy by using it as energy to transform the ink from a solid state to a liquid state, or to use ink that solidifies when left in order to prevent ink evaporation. However, in any case, the ink may be liquefied by applying thermal energy in accordance with the recording signal and ejected as liquid ink, or the ink may already begin to solidify by the time it reaches the recording medium. The present invention is also applicable to the use of ink that is liquefied only by energy. In such a case, the ink is held in a liquid or solid state in the recesses or through holes of the porous sheet, as described in JP-A-54-56847 or JP-A-60-71260. It may also be in a form in which it faces the electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

[Effects of the Invention] As explained above, the present invention provides the following effects.

(1) Set a timer when the inkjet recording device is powered off, and when the inkjet recording device is powered on,
By reading the count number of the timer, it is possible to determine the non-use time of the inkjet recording device, and furthermore, the amount of ink discharged from the inkjet recording head in the head recovery operation is determined in accordance with the non-use time. This eliminates wasted ink even if the power is turned on and off frequently, and even if the ink in the inkjet recording head has a high degree of viscosity, it is reliably removed. can do.

(2) Since the head recovery operation is performed when the power of the inkjet recording apparatus 4 is turned on, foreign matter that causes ink failure to be ejected is reliably removed from the inkjet recording head before the recording operation is started. The accuracy of image recording is increased, and the reliability of the recording device is improved.

(3) In the case of the item described in claim 2, even if the power is turned off again immediately after the inkjet recording device is turned on, the timer will not be reset and will continue counting if the head recovery operation has not been completed. , it is possible to accurately determine the non-use time of the inkjet recording apparatus during which no recording operation is performed.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of an inkjet recording apparatus of the present invention, FIG. 2 is a perspective view showing an example of a recording head,
FIG. 3 is a block diagram showing the inkjet recording apparatus of FIG. 1, FIG. 4 is a block diagram showing the controller, and FIGS. 5 (A) and (B) are timings showing the timing of setting and resetting the timer by the controller, respectively. FIG. 6 is a flowchart showing an example of the operation of the inkjet recording apparatus of the present invention. ■...Inkjet head cartridge, 2...
Carriage, 3... Inkjet recording head, 4... Drive head, 5... Drive motor, 6a, 6b
... Guide shaft, 7 ... Platen, 8 ... Head recovery device, 8a ... Cap member, 9 ... Blade, 9a ... Blade holding member, 10 ... Cleaning motor, 11 ... Transmission mechanism, 12... Nozzle, 13... Electrothermal converter, 20... Host device, 30... Controller, 31... Timer, 32... Panel, 33...
... Interface circuit, 34... Head drive system sensor, 35... Mechanical drive system sensor, 36... Recovery device drive circuit, 37... Power switch, 38... Power supply device, 301
...MPU, 302...ROM. 303... Comparison circuit, 304... Mote table,
501-514...step.

Claims (1)

[Claims] 1. In an inkjet recording apparatus having a controller that discharges ink from the inkjet recording head and performs a head recovery operation of the inkjet recording head when the power is turned on, the non-use time of the inkjet recording apparatus is counted. The controller includes a timer that: corresponds to non-use time of the inkjet recording device;
a storage unit pre-stored with a mode table in which a recovery operation mode indicating the amount of ink discharged during the head recovery operation is set; and a timer control means for resetting the timer after reading the count number, and searching the mode table based on the count number read by the timer control means and resetting the timer after reading the count number. and a control means for discharging ink from the inkjet recording head according to the recovery operation mode selected by the comparison means. Inkjet recording device. 2. The inkjet recording apparatus according to claim 1, wherein the timer control means of the controller resets the timer at the end of the head recovery operation. 3. An ink inflow means for forcibly flowing ink into the inkjet recording head and discharging the ink is provided, and the mode table indicates the amount of ink discharged from the inkjet recording head due to the ink inflow of the ink inflow means. 3. The inkjet recording apparatus according to claim 1, wherein the recovery operation mode shown is determined corresponding to the non-use time of the inkjet recording apparatus. 4. 4. The inkjet recording apparatus according to claim 1, wherein the inkjet recording head discharges ink using thermal energy, and includes an electrothermal converter that applies the thermal energy to the ink. .