JPH10146993A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent troubles from generating at the time of a re-usage after being left to stand even when the ink jet printer has been left to stand for a long period of time under a non-printing state wherein there are no dischargings and drawings of an ink by a method wherein a thickened ink removing process for the printing head is periodically performed based on a measurement result of a clock measuring means. SOLUTION: This ink jet printer 1 is equipped with a main body control part 100, a humidity sensor 10 which measures a relative humidity, a printing part 20 (a thickened ink removal executing means) which performs a flushing, and a power source circuit 40, etc. The overall motion of the ink jet printer 1 is controlled by the main body control part 100, and for the main body control part 100, a CPU 110, a memory 120, a timer 140 to measure an elapsed time, etc., of a non-printing period, and an operation circuit 150 which performs a detect-operation of a flushing timing based on the information from the humidity sensor and the timer 140, etc., are connected to each other. Then, in the printer 1, a maintenance flushing process (thickened ink removing process) is performed by the main body control part 100, and a temperature sensor 10, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer having a thickening ink removing function such as a cleaning function and a flushing function.

[0002]

2. Description of the Related Art Conventionally, an ink jet printer of this type has used an ink (hereinafter referred to as a "viscosity ink") which is solidifying due to evaporation of a solvent (eg, water in the case of a water-soluble ink).
) To remove thickened ink such as cleaning and flushing.

For example, at the start of printing after a lapse of a predetermined time from the end of printing, at the start of printing after replacing an ink cartridge, or when an operator finds a printing defect, FIG.
As shown in (2), at the home position HP, the head cap 24 is brought into close contact with the print head 21 provided at the tip of the carriage 23 in which the ink cartridge 29 is set, and the carriage 23 is closed.
7, the ink is collected in the ink absorbing material 26 by the pump 28, or a process such as wiping or lapping of the surface of the print head 21 is performed. That is, cleaning is performed.

The head cap 24 is mounted on the print head 2.
When a predetermined time has elapsed in a printing operation or the like that is not in close contact with the printing head 1 or when printing is completed, the carriage 23 is returned from the printing range PA to the home position HP, and
1 is directed to the head cap 24 and a small amount of ink is ejected from all the nozzles 22 of the print head 21. That is, so-called flushing is performed. Immediately after the main power is turned on, the above cleaning and flushing are performed alone or in combination. By these processes, the thickened ink generated at the outlet of the nozzle 22 and the surrounding ink path is removed to prevent clogging and the like.

[0005]

However, in such a conventional ink jet printer, even if the printing head 21 is in close contact with the head cap 24, the ink cartridge 29 remains set for a long time even if the printing head 21 is in close contact with the head cap 24. If left unattended (about several months), not only the inside of the nozzle 22 but also a part of the ink in the ink path from the ink cartridge 29 to the nozzle 22 solidifies due to evaporation of the solvent, and the ink path becomes clogged. Due to the state, there is a disadvantage that printing cannot be performed normally at the next use only by cleaning or flushing performed at the time of normal startup. Further, in order to recover from the state, a new ink cartridge 29 is set and the solidified ink is redissolved.
Cleaning such as 1 is repeatedly performed by the pump 28 many times, and if necessary, a recovery process such as replacement of the print head 21 is required. Therefore, there is a trouble that the printer cannot be used immediately when desired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has been made in the non-printing mode in which ink is not ejected and sucked from a print head, such as when the print head is in close contact with a head cap. An object of the present invention is to provide an ink jet printer which does not hinder reuse after being left for a long time in a state.

[0007]

According to a first aspect of the present invention, there is provided an ink jet printer, comprising: a time measuring means for measuring an elapsed time in a state where a print head is in close contact with a head cap; and the printing based on a measurement result of the time measuring means. A thickened ink removing unit that periodically executes a thickened ink removing process of the head.

This ink-jet printer periodically executes the thickening ink removing process even in a non-printing state in which the print head is in close contact with the head cap. Etc. can be maintained. As a result, a normal printing operation or the like can be immediately performed without any trouble even when reused after being left unattended. Here, the thickened ink removal processing is a concept including cleaning, flushing, and the like.

An ink jet printer according to a second aspect of the present invention is an ink jet printer using an ink as a solution having a solvent, wherein a time measuring means for measuring an elapsed time in a state where the ink is not ejected or sucked from a print head, The printing apparatus further includes an evaporation rate parameter measuring unit that measures a parameter related to an evaporation rate of the solvent, and a thickened ink removing unit that performs a thickened ink removing process of the print head.

In general, ink-jet inks have environmental parameters (e.g., relative humidity in the case of water-soluble ink using water as a solvent, environmental temperature in the case of oil-soluble ink using kerosene as a solvent, for example). ), The time required for solidification by evaporation of the solvent differs. According to this inkjet printer, a state in which ink is not ejected and sucked from the print head, for example,
In addition to measuring the elapsed time when the print head is in close contact with the head cap or in a non-printing state such as when printing is stopped for other reasons, it measures parameters related to the evaporation rate of the solvent. Based on the result, it is possible to calculate an appropriate timing and the like for executing the thickened ink removing process such as cleaning or flushing.

3. The ink jet printer according to claim 2, wherein the thickened ink removing means calculates the timing of the thickened ink removing processing based on the measurement result of the time measuring means and the measurement result of the evaporation rate parameter measuring means. It is preferable to have a calculating means for performing the thickening ink removal processing at the timing calculated by the calculating means.

In this ink jet printer, the timing of the thickened ink removal processing is calculated based on the measurement result of the time measuring means and the measurement result of the evaporation rate parameter measuring means, and the thickened ink removal processing is executed at that timing. Even if the printer is left in a non-printing state, it is possible to remove the thickened ink in consideration of the external environment, whereby the thickened ink removing process can be performed efficiently.

4. An ink jet printer according to claim 3, wherein said ink is a water-soluble ink, said evaporation rate parameter measuring means is a humidity sensor for measuring relative humidity, and said arithmetic means is measured by said humidity sensor. The evaporation rate of water in the water-soluble ink is obtained from the relative humidity obtained, and the evaporation rate of water in the water-soluble ink per minute time is obtained based on the evaporation rate and the measurement result of the time measuring means. It is preferable to accumulate the amount of evaporation per unit to obtain an accumulated amount of evaporation, and calculate the timing from the accumulated amount of evaporation.

Generally, the time required for the water-soluble ink to dry and solidify depends on the evaporation rate of water from the ink, that is, the amount of water evaporation per unit area per unit time.
The evaporation rate changes depending on the relative humidity at that time.
According to this inkjet printer, the evaporation rate of water is determined from the measured relative humidity, and the evaporation rate per minute of water in the water-soluble ink is determined based on the evaporation rate and the measurement result of the time measurement unit. From the cumulative evaporation amount obtained by accumulating the evaporation amount, it is possible to calculate a good timing that satisfies the necessary and sufficient conditions that require the removal of the thickened ink,
Appropriate and flexible response to environmental changes.

5. The ink jet printer according to claim 4, wherein said thickening ink removing means further comprises a storage means for storing a conversion table for converting the evaporation rate of said moisture from said relative humidity, and said arithmetic means comprises: Finding the evaporation rate of the water by referring to the conversion table,
preferable.

According to this configuration, by storing the conversion table, the evaporation rate of water can be easily obtained by referring to the conversion table. Further, by using the conversion table, for example, even when it is desired to use inks having different characteristics, it is possible to cope only by rewriting the values of the conversion table without changing the configuration of the above-described arithmetic unit of the ink jet printer. Further, for example, printing using a plurality of types of inks can be handled by storing a conversion table for each type of ink, thereby expanding the applicable range.

The ink jet printer according to claim 3, wherein said ink is an oil-soluble ink, said evaporation rate parameter measuring means is a temperature sensor for measuring an environmental temperature, and said calculating means is measured by said temperature sensor. The evaporation rate of the solvent of the oil-soluble ink is obtained from the environmental temperature obtained, and the amount of evaporation of the solvent of the oil-soluble ink per minute time is obtained based on the evaporation rate and the measurement result of the time measuring means. It is preferable to accumulate the amount of evaporation per unit to obtain an accumulated amount of evaporation, and calculate the timing from the accumulated amount of evaporation.

Generally, the time required for the oil-soluble ink to dry and harden depends on the solvent (eg, kerosene) from the ink.
The evaporation rate varies depending on the environmental temperature at that time. According to this inkjet printer, the evaporation rate of the solvent is determined from the measured environmental temperature, and the evaporation rate per minute of the solvent of the oil-soluble ink is determined based on the evaporation rate and the measurement result of the time measurement unit. From the accumulated evaporation amount obtained by accumulating the evaporation amount, it is possible to calculate a good timing that satisfies a necessary and sufficient condition for removing the thickened ink, and it is possible to appropriately and flexibly cope with a change in environment.

6. The ink jet printer according to claim 6, wherein said thickened ink removing means further comprises a storage means for storing a conversion table for converting an evaporation rate of said solvent from said environmental temperature, and said arithmetic means comprises: Finding the evaporation rate of the solvent with reference to the conversion table,
preferable.

According to this configuration, by storing the conversion table, the evaporation rate of the solvent of the oil-soluble ink can be easily obtained by referring to the conversion table. In addition, by using the conversion table, the same effect as in the case of the water-soluble ink described above can be obtained.

It is preferable that the ink jet printer according to any one of claims 1 to 7, further include a sub power supply for supplying power to the thickened ink removing means during a main power supply off period.

In this ink jet printer, power is supplied from the sub power supply during the main power supply off period. Therefore, even when the main power supply is turned off, even when the main power supply is turned off, the removal of the thickened ink is performed. Can be executed without hindrance, whereby the above-mentioned advantages of claims 1 to 7 can be maintained, and can be used immediately when the user wants to use it next time.

[0023] In the ink jet printer according to any one of claims 1 to 8, it is preferable that the thickened ink removing means is a flushing means for executing flushing as the thickened ink removing process.

According to this ink jet printer, by executing flushing as the thickened ink removing process, the above-described effects of claims 1 to 8 can be obtained.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet printer according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the ink jet printer described below, flushing in a non-printing state in which the print head is in close contact with the head cap is performed as the thickened ink removal processing performed during the non-printing period.

FIG. 1 shows an example of an ink jet printer to which the present invention is applied. As shown in FIG. 1, the ink jet printer 1 includes a main body control unit 100, a humidity sensor (evaporation rate parameter measuring unit) 10 for measuring relative humidity, a printing unit (a thickening ink) for performing printing and flushing described above with reference to FIG. A power supply circuit (main power supply, sub power supply) 40, and other units 50 in the inkjet printer 1. The ink used is water-soluble.

This ink-jet printer 1 is equivalent to a conventional general ink-jet printer except for the features of the present invention described in detail below. FIG. 1 collectively shows components not related to the present invention and other components. It is abbreviated as 50. Further, since the printing unit 20 has the same configuration as the conventional one, the description of FIG. 5 will be used instead, and other description of the configuration and the like will be omitted. However, this printing unit 2
0 is also used for maintenance flushing during a non-printing period, which will be described later, in addition to the general flushing described above, and is shown separately from the other units 50 in FIG.

The overall operation of the ink jet printer 1 is controlled by the main body control unit 100. As shown in FIG. 1, the main body control unit 100 includes a CPU 110, a memory (storage unit) 120, a power supply control circuit 130 for controlling a power supply circuit, and a timer for measuring elapsed time and other time in a non-printing period described later. (Time measuring means) 140,
An arithmetic circuit (arithmetic means) 150 for performing an arithmetic operation for detecting a flushing timing, which will be described later, and other arithmetic processing based on information from the humidity sensor 10 and the timer 140;
A printing unit controller 160 for controlling the printing unit 20 for normal printing operation and flushing according to a command from the printer 10; and other unit controllers 170 for controlling the other units 50. Are interconnected. Other controllers 17
0 is also omitted for the same reason as the other units 50 described above.

The memory 120 includes a ROM 121 and a RAM 1
The ROM 121 stores a control program and the like for controlling each unit in the inkjet printer 1 in addition to a maintenance flushing process to be described later.
The AM 122 stores various data such as normal printing data in addition to a conversion table and a battery power-on flag described later. The CPU 110 outputs control signals to each unit via the internal bus 180 by processing the data in the RAM 122 according to the program in the ROM 121, and as a result, controls the entire inkjet printer 1 as the main body control unit 100. .

The power supply circuit 40 includes a normal main power supply 41,
A battery power source 42 is provided as a sub power source, and a power cable 43
Power is supplied to each unit in the inkjet printer 1 via the. When the main power supply 41 is turned off, the battery power supply 42 supplies various components in the inkjet printer 1, particularly, the main body control unit 100, the humidity sensor 10, and the printing unit 2.
0, the power is supplied in place of the main power supply 41, whereby even during the main power off period,
The maintenance flushing process described below can be performed. In this case, the power supply circuit 40 is also controlled by the CPU 110 via the power supply control circuit 130.

In the ink jet printer 1 of this embodiment, the maintenance flushing process (thickening ink removal process), which is a feature of the present invention, is performed by the main body controller 100 and the humidity sensor 1.
0, printing unit 20 and battery power supply 42 in power supply circuit 40
Performed by

Here, the relationship between the maintenance flushing timing and the accumulated ink evaporation amount will be described. Since the ink jet printer of this embodiment uses a water-soluble ink, the component (solvent) that evaporates in this embodiment is moisture.

The evaporation rate of the solvent of the ink, that is, the evaporation amount of the water content of the ink per unit time per unit area can be estimated using the relative humidity as a parameter. Assuming that the relative humidity (reciprocal) that changes in the elapsed time with respect to the elapsed time draws a curve as shown in FIG. 3, the evaporation rate of the ink depends on the function f (x) based on the characteristics of the ink.
(X = 1 / relative humidity). For this reason,
Ink evaporation amount f (x) × Δt per minute time Δt
Is accumulated for the elapsed time, the accumulated evaporation amount of the water content of the ink per unit area can be obtained. For example,
Assuming that the evaporation amount per unit time is proportional to the reciprocal of the relative humidity, the accumulated evaporation amount from the ink is proportional to the area between the curve and the elapsed time axis in FIG.

For the sake of simplicity, as shown in FIG. 4, three types of cumulative evaporation per unit area where the evaporation rate of water from the ink is constant and different from each other due to the difference in ink characteristics and the above-mentioned relative humidity. Curve (a), (b),
Consider (c). (D) shows the nozzle 2 of the print head 21.
2 shows the limit line of the accumulated evaporation amount at which the ink path of the second class (see FIG. 5) is clogged, that is, the limit line which cannot be used immediately at the next use due to drying and solidification of the ink. As is clear from the figure, the timing at which flushing is required is based on the cumulative evaporation amount rise curves (a), (b),
The timings ta, tb, and tc respectively correspond to (c).
Becomes

On the other hand, the evaporation rate V of the water content of the ink can be calculated, for example, from the relative humidity hum without calculating the function f (x) based on the characteristics of the ink.
If a conversion table TB for converting the evaporation rate is prepared, the evaporation rate V can be obtained by referring to the conversion table TB.
(Hum) and the minute evaporation time Δt, the accumulated evaporation amount can be easily obtained.

For this reason, in the ink jet printer 1, the above conversion table TB is stored in the RAM 122, and based on the relative humidity hum measured by the humidity sensor 10, the evaporation rate V is referred to by referring to the conversion table TB.
(Hum), and from the evaporation rate V (hum) and the elapsed time data obtained from the timer 140, an ink evaporation amount f (x) × Δt per minute time Δt is obtained, and the results are accumulated. By obtaining the accumulated evaporation amount VAP from the ink, it is possible to determine a good timing that satisfies the necessary and sufficient conditions for the flushing.

The conversion table TB is determined based on, for example, actual measurement data measured in advance for each type of ink, and is stored in the RAM 122. In the above case, the evaporation rate V (hum) and the minute time Δt
Is the evaporation amount f of the ink per minute time Δt
If a conversion table TB2 for converting (x) × Δt is prepared, the calculation of the evaporation amount f (x) × Δt of the ink can be omitted by referring to the conversion table TB2. Of course, a conversion table TB3 for directly converting the ink evaporation amount f (x) × Δt per minute time Δt using the relative humidity hum and the minute time Δt as arguments may be used.

Next, a maintenance flushing processing flow in the ink jet printer 1 will be described with reference to FIG. When the normal printing process or the like is completed, the carriage 23 returns to the home position HP, and after normal flushing at the time of printing completion is performed, the head cap 2
4 is in close contact with the print head 21 and is closed, and enters a non-printing state waiting for the next printing start. Here, the inkjet printer 1 starts a maintenance flushing process.

As shown in FIG. 2, when the maintenance flushing process is started, even if the main power supply 41 is turned off, the battery power supply ON flag is prepared so that the following maintenance flushing process can be performed. Is set. That is, after this, when the main power supply 41 is turned off, the inkjet printer 1 performs
For example, post-processing such as saving various data and various flags in the RAM 122 to a save area for restart is performed, and by referring to the battery power-on flag,
After the battery power supply 42 is turned on, the supply of power from the main power supply 41 is stopped.

When the battery power supply 42 is turned on, power supplies for the main body control unit 100, the humidity sensor 10, and the printing unit 20 during the main power supply off period are secured (S1). In this case, the other controllers 170 in the main body controller 100
Is disconnected from the power supply system as needed, but may be used as long as it does not consume power when it does not operate.

When the power is secured (S1), the timer and the like are initialized (S2). In this case, for example, the timer 140 may be of a reset type, or may be of a type in which the time at that time is stored and the elapsed time from that time is obtained as a difference and output. In the case where there is a timer for controlling the date and time for control in the inkjet printer 1, for example, the elapsed time is obtained by calculation from the display time of the timer for date and time management, thereby replacing the latter type of timer. You can also. Similarly to the timer 140, the humidity sensor 10 also performs initial setting as necessary, and the accumulated evaporation amount VAP (i) = 0 (where i is a variable corresponding to the unit time ΔT (i),
At the time of initialization, the initialization (i = 0) is performed, and then the initialization processing (S2) is terminated.

When the initialization process (S2) is completed, the elapsed time TIM from the transition to the non-printing state by the timer 140, ie, the elapsed time T in the non-printing period,
At the same time as extracting the IM, the relative humidity hum at that time is measured by the humidity sensor 10, and those results are taken into the RAM 122 as processing data (S3).

After the extraction of the relative humidity hum and the elapsed time TIM (S3) is completed, the ink accumulated evaporation amount VAP
The calculation of (i) is performed (S4). In this process, as described above, the evaporation speed V (hum) is obtained from the relative humidity hum with reference to the conversion table TB, and the elapsed time TI
The elapsed time from the previous calculation time, that is, the minute time ΔT (i) is obtained from the data of M (S41).

Next, based on these, the minute time Δ
The evaporation amount VAP (i) at this time is obtained by adding the evaporation amount V (hum) × ΔT (i) at T (i) to the accumulated evaporation amount VAP (i-1) up to the previous time (i−1). . That is, in this process, the current accumulated evaporation amount VAP (i) = the accumulated evaporation amount VAP (i-1) + the evaporation speed V (hum) × the minute time ΔT (i) is obtained (S42). At this point,
Since it is still the first time (i = 1), the accumulated evaporation amount VAP (i-1) = 0 until the previous time (i-1 = 0) is obtained, and the first accumulated evaporation amount VAP (1) = evaporation speed V (hum). ) × small time ΔT (1) is obtained.

Calculation of accumulated ink evaporation amount VAP (i) (S
When 4) is completed, it is determined whether or not the accumulated evaporation amount VAP (i) has reached the accumulated evaporation amount corresponding to the clogging limit line (S5). If the clogging limit line has not been reached (S5: No), then the relative humidity h
Extraction of um / elapsed time TIM (S3) and calculation of accumulated ink evaporation amount VAP (i) (S4) are performed.

Thus, the second (i = 2) cumulative evaporation amount VAP (2) = cumulative evaporation amount VAP (1) + evaporation speed V
(Hum) × small time ΔT (2) is obtained. Here, the minute time ΔT (2) is the elapsed time from the previous time (i−1 = 1), that is, the first accumulated evaporation amount VAP (1).

Then, similarly to the first time (i = 1), it is determined whether or not the clogging limit line has been reached. If the clogging limit line has not been reached (S5: N)
o) Hereinafter, similarly, the third, fourth,... (i = 3,
Extraction of relative humidity hum / elapsed time TIM (4, ...) (S
3) calculation of accumulated ink evaporation amount VAP (i) (S4),
Also, whether or not it is the clogging limit line (S5) is reached or exceeds the clogging limit line (S5: Yes).
Up to a certain sampling interval.

When the clogging limit line is reached or exceeded (S
5: Yes), and then execute flushing (S
6). In this process, as described above with reference to FIG. 5, by discharging a small amount of ink from all the nozzles 22 of the print head 21, it is possible to prevent clogging of the nozzles 22 and the like of the print head 21 due to drying and solidification of the ink. I do.

When the flushing process (S6) is completed,
Next, the initialization process (S2) is performed again. From the first time (i = 1), the relative humidity hum and the elapsed time TIM are extracted (S3), and the calculation of the accumulated ink evaporation amount VAP (i) ( S4), and determination as to whether or not it is the clogging limit line (S5)
Until the clogging limit line is reached (S5: Yes).
Repeatedly, the clogging limit line is reached (S5: Y
At es), flushing is performed (S6). This loop processing (S2 to S6) is repeated until the printing processing is restarted, that is, until the non-printing state is released.

Here, the main power supply 41 is turned off during the non-printing period, and the main power supply 41
Is turned on again, the inkjet printer 1 restarts the supply of power from the main power supply 41, turns off the battery power supply 42, and performs various interrupt processing (not shown), for example, to store various data and the like in the RAM 122. Initialization such as returning information of various flags from the evacuation area is performed, and a non-printing state in which the processing waits until print processing is resumed. When the printing process is restarted, the process exits from the above-described loop process (S2 to S6) of the maintenance flushing process in FIG. 2, terminates the maintenance flushing process, and returns to the process flow such as the normal printing process.

As described above, the ink jet printer 1 to which the present invention is applied performs flushing at an appropriate timing even during a non-printing period. The state in which the thickened ink has been removed can be maintained, and the ink can be used immediately when desired. In addition, the relative humidity hum is measured, and the evaporation amount V × ΔT per minute time ΔT is obtained based on the measurement result. From the accumulated evaporation amount VAP, the necessary and sufficient conditions for the necessity of flushing are satisfied. It is possible to calculate a good timing to perform the maintenance flushing efficiently and to appropriately and flexibly respond to changes in the environment.

Further, a battery power supply 42 is provided as a sub-power supply for supplying power during the off-period of the main power supply 41, and flushing is performed using the power of the battery power supply 42 during the off-period of the main power supply 41. Even if the main power supply 42 is turned off during the period, the maintenance flushing can be executed without any trouble, thereby maintaining the above advantage that the device can be used immediately at the next use.

Further, according to the ink jet printer 1 of the present embodiment, by storing the conversion table TB, the evaporation rate V can be easily obtained by referring to the conversion table TB. When the user wants to use it, the same configuration can be used only by rewriting the value of the conversion table TB. Furthermore, printing in which a plurality of types of inks are used can be handled by storing the conversion table TB for each type of ink, so that the applicable range is wide.

The present invention is not limited to the embodiment described above, but can be implemented in various modes.

For example, in the above embodiment, an ink jet printer using a water-soluble ink has been described.
The present invention is also applicable to an ink jet printer using an oil-soluble ink. In the case of an oil-soluble ink, the solvent (solvent), for example, kerosene evaporates to become a thickened ink, so that the evaporation amount of such a solvent is measured. In the case of kerosene, the amount of evaporation per minute time changes according to the temperature. Therefore, the environmental temperature is measured using a temperature sensor instead of the humidity sensor 10. The conversion table TB is also replaced with a conversion table for converting the measured value of the environmental temperature into the evaporation rate.

As described above, also in the case of the ink jet printer using the oil-soluble ink, the evaporation rate of the solvent of the oil-soluble ink is determined by using the parameters measured by using a suitable sensor, and the evaporation rate and time measurement are performed. The amount of evaporation of the solvent per minute time is determined based on the elapsed time measured by the means. By accumulating the amount of evaporation, the accumulated amount of evaporation can be obtained, and the appropriate timing of flushing can be determined based on the accumulated amount of evaporation.

In the above embodiment, the flushing timing is detected by judging whether or not the accumulated evaporation amount has reached the clogging limit line. If is somewhat predictable, based on elapsed time alone, more simply, for example,
Flushing can also be performed periodically every two to three months.

In the maintenance flushing process described above with reference to FIG. 2, when the flushing process (S6) is completed, the initialization (S2) is performed again. In the same manner as the type that obtains the elapsed time, instead of performing the initialization (S2) again, the time of the last flushing processing (S6) is stored, and the elapsed time from that time is stored in the elapsed time. It may be calculated as TIM. Further, when flushing is performed periodically, for example, once every two months or the like based only on the elapsed time, the flushing process (S
Every time 6), the timer 140 may be reset to measure two months again, or the elapsed time from the beginning may be two months,
, Six months,... May be detected, and the flushing process (S6) may be performed.

In the above-described embodiment, a battery power supply is used as a sub power supply. However, a rechargeable backup power supply that can be charged when an outlet is connected can be used as the sub power supply. . In addition, by providing a power supply system different from the other parts in the ink jet printer at the part where maintenance flushing is performed, the main power supply is connected when the outlet of the main unit is connected, and the backup power supply or Power may be supplied from a battery power supply or the like. In addition, a timer (time measuring means) or the like that is driven by a mainspring, a solar cell, or the like can also be used.

In the above-described embodiment, the flushing is performed as the thickened ink removing process performed during the non-printing period. However, since it is sufficient that the thickened ink can be removed, cleaning and other thickened ink removing processes are performed. You can also. Further, in the above embodiment, the conversion table TB is stored in the RAM 122, but it goes without saying that the conversion table TB may be stored in the ROM 121 together with the control program.

In the above-described embodiment, the evaporation amount of water per minute time is calculated, and then the accumulated evaporation amount is calculated. The routine of the maintenance flushing process of FIG. 2 is executed at minute unit time intervals. By omitting the extraction and multiplication of the minute time and directly converting and integrating the evaporation amount per minute unit time from the conversion table TB or the like, the accumulated evaporation amount of water (solvent) from the ink can also be obtained. .

Further, in the above-described embodiment, the normal printing process and the like are completed in the non-printing state, and the home position H
In P, a non-printing state is assumed in which the head cap 24 is in close contact with the print head 21 and is closed. For example, when the outlet is suddenly unplugged during the printing operation, the ink discharge or ink discharge without blocking by the head cap is performed. A change can be made so as to be able to cope with the case of shifting to the non-printing state without suction.

In this case, for example, when it is detected that a non-printing state in which ink is not ejected or sucked for some reason due to multitasking or interrupt processing, maintenance is always performed prior to other processing. It is possible to change the entire control so that the flushing process is started and the process returns to the normal print process flow when the print process is started.

That is, when the maintenance flushing process is started, the battery power-on flag is set immediately as described above with reference to FIG. 2, so that the non-printing state may be caused by the sudden disconnection of the outlet. In the subsequent interrupt processing, post-processing such as saving various data and information of various flags is performed, and after turning on the battery power supply 42 with reference to the battery power-on flag, the power supply from the main power supply 41 is performed. The supply is stopped, and the maintenance flushing process can be continued.

In the case of the above-described change, the ink ejected in the flushing process is received as shown in FIG.
At the beginning of the maintenance flushing process, the carriage 23 may be returned to the home position, and a process of closing with the head cap 24 may be inserted. Regardless of the position of the carriage 23, for example, paper or a head cap may be used. A mechanism that covers the print head may be provided. Further, even if there is no paper to be printed, a function of absorbing ink may be added to the feeding surface of the printing paper so that ink can be freely discharged at any position.

In addition, the configuration and the like of the details can be appropriately changed without departing from the spirit of the present invention.

[0067]

As described above in detail, according to the ink jet printer of the present invention, in a non-printing state in which ink is not ejected and sucked from the print head, such as a state in which the print head is in close contact with the head cap. Even if it is left for a long period of time, there is an effect that it can be used immediately when it is desired to use it without hindering reuse after leaving.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an inkjet printer according to an embodiment of the present invention.

FIG. 2 is a diagram showing a maintenance flushing process flow by the inkjet printer of FIG. 1;

FIG. 3 is an explanatory diagram of an evaporation amount per minute time of a water content of ink and a cumulative evaporation amount.

FIG. 4 is a diagram for explaining the relationship between maintenance flushing timing and the accumulated evaporation amount of water from ink.

FIG. 5 is a schematic diagram illustrating a flushing process in a printing unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inkjet printer 10 Humidity sensor (evaporation speed parameter measurement means) 20 Printing part (viscosity ink removal execution means) 21 Print head 22 Nozzle 23 Carriage 24 Head cap 25 Ink absorber 26 Ink absorber 27 Ink recovery pipe 28 Pump 29 Ink Cartridge 40 power supply circuit 41 main power supply 42 battery power supply (sub-power supply) 43 power supply cable 50 other parts in printer 100 main body control unit 110 CPU 120 memory (storage means) 121 ROM 122 RAM 130 power supply control circuit 140 timer (time measuring means) 150 arithmetic circuit (arithmetic means) 160 printing unit controller 170 other units controller 180 internal bus HP home position PA printing range

Claims (9)

[Claims] 1. A time measuring means for measuring an elapsed time of a state in which a print head is in close contact with a head cap, and a thickening ink removing process of the print head is periodically performed based on a measurement result of the time measuring means. An ink jet printer comprising: a thickening ink removing unit that executes the ink. 2. An ink jet printer using an ink as a solution having a solvent, comprising: a time measuring means for measuring an elapsed time in a state where the ink is not ejected and sucked from a print head; An ink jet printer comprising: an evaporation rate parameter measuring unit for measuring related parameters; and a thickened ink removing unit for executing a thickened ink removing process of the print head. 3. The calculating means for calculating the timing of the thickening ink removal processing based on the measurement result of the time measuring means and the measurement result of the evaporation rate parameter measuring means, An ink jet printer comprising: a thickened ink removal executing unit that executes the thickened ink removing process at the timing calculated by the calculating unit. 4. The ink according to claim 1, wherein the ink is a water-soluble ink, the evaporation rate parameter measuring means is a humidity sensor for measuring a relative humidity, and the calculating means is a water-soluble ink based on the relative humidity measured by the humidity sensor. The evaporation rate of water in the water-soluble ink,
Based on the evaporation rate and the measurement result of the time measuring means, the amount of evaporation of water in the water-soluble ink per minute time is obtained, and the amount of evaporation per minute time is accumulated to obtain an accumulated amount of evaporation. The inkjet printer according to claim 3, wherein the timing is calculated from an evaporation amount. 5. The thickening ink removing unit further includes a storage unit for storing a conversion table for converting the evaporation rate of the moisture from the relative humidity, and the calculation unit refers to the conversion table. 5. The ink jet printer according to claim 4, wherein the evaporation rate of the moisture is obtained by using the following method. 6. The ink according to claim 1, wherein the ink is an oil-soluble ink, the evaporating rate parameter measuring means is a temperature sensor for measuring an environmental temperature, and the calculating means is an oil based on the environmental temperature measured by the temperature sensor. Determine the evaporation rate of the solvent of the soluble ink,
Based on the evaporation rate and the measurement result of the time measuring means, the amount of evaporation of the solvent of the oil-soluble ink per minute time is obtained, and the amount of evaporation per minute time is accumulated to obtain a cumulative evaporation amount. The inkjet printer according to claim 3, wherein the timing is calculated from an evaporation amount. 7. The thickening ink removing unit further includes a storage unit for storing a conversion table for converting the evaporation rate of the solvent from the environmental temperature, and the calculation unit refers to the conversion table. The ink-jet printer according to claim 6, wherein the evaporation rate of the solvent is obtained by using the following method. 8. The ink jet printer according to claim 1, further comprising a sub power supply for supplying power to said thickened ink removing means during a main power off period. 9. The ink jet printer according to claim 1, wherein said thickened ink removing means is a flushing means for executing flushing as said thickened ink removing process.