JPH068458A - Driving method for ink jet recording head - Google Patents

Abstract

PURPOSE:To enable electric power for preliminary discharge control to be reduced by a method wherein a quantity of preliminary discharge is changed between a case where input of a key is received again within specific time after turning off a specific power source of an ink jet recorder and a case where input of the key is received again after measuring for specific time after turning off its specific power source. CONSTITUTION:In an ink jet recorder, a quantity of preliminary discharge to be carried out after inputting an ON key is changed between a case where input of the ON key is received within specific time by counting specific time with a built-in arithmetic controller and a case where input of the ON key is received after counting the specific time after recorder's automatic power off or off with an OFF key, i.e. after apparent off of a power source by stopping operation of the recorder, or by turning off display. Consequently, since driving of a DC/DC converter circuit for supplying power from an electric cell to each part is stopped after counting specific time and power consumption in the DC/DC converter circuit is prevented, and besides the arithmetic controller until the ON key is received again is made a low power consumption mode, the recording head will be enabled to be driven even with a dry cell.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving an ink jet recording head, which is suitable for an ink jet recording apparatus using a battery as a power source.

[0002]

2. Description of the Related Art Most of the conventionally known ink jet recording apparatuses are driven by an AC power source. Even when batteries are used, secondary batteries having a large capacity such as Ni-Cd batteries are used. It had been.

FIG. 6 is a schematic configuration diagram of an ink jet recording head mounted in a conventionally known ink jet recording apparatus.

In FIG. 6, reference numeral 601 denotes a heater board, which is an electrothermal converter (discharge heater) 60 on a silicon substrate.
2 and wiring 6 such as aluminum 4 for supplying electric power to this
03 are formed by a film forming technique. Then, with respect to the heater board 601, a top plate 608 provided with a partition wall for limiting the liquid path (nozzle) 606 of the recording liquid is provided.
The ink jet recording head is configured by bonding the.

A recording liquid (ink) is supplied to a common liquid chamber 604 through a supply port 605 provided in a top plate 608, and is introduced into each nozzle 606 from here. Then, when the heater 602 generates heat by energization, bubbling occurs in the ink filled in the nozzle 606, and an ink droplet is ejected from the ejection port 607.

When the recording head shown in FIG. 6 is not driven for a while, the water content of the ink supplied to each nozzle evaporates to increase the viscosity and clogging of the ink at the initial recording stage. Occurs and printing defects occur.
Therefore, in the conventional ink jet head driving device, as shown in FIG. 7, the preliminary ejection of the amount N corresponding to the time T not driven and proportional to the time T is executed.

That is, in the preliminary ejection, the high-viscosity ink is discharged from the ejection port 607 to an ink absorber (not shown) at a predetermined position unrelated to printing, and the low-viscosity ink is fed from the common port through the supply port 605. Supply into each nozzle through chamber 604, which reduces the viscosity of the ink,
I got normal printing from the beginning. That is, the preliminary ejection amount corresponding to the time Ti that has not been driven is ni as shown in FIG.

Further, for the time _exceeding T _max in FIG. 7, the preliminary discharge of n _{max by} the same amount as when the power is turned on is executed. This is because, due to the structure of the nozzle 606 and the common liquid chamber 604, it has been experimentally proved that most of the ink clogging can be eliminated by preliminary ejection of n _max .

[0009]

However, since the conventional ink jet recording apparatus is AC-driven, there is a sufficient power supply, so that the electric power for measuring the time T (see FIG. 7) during which the ink-jet recording apparatus is not driven is used. Power consumption in the circuit was not a problem.

On the other hand, an AC cord is required,
Since the power supply circuit is large, it has drawbacks such as (1) poor portability, (2) difficulty in downsizing, and (3) high cost.

Therefore, in view of the above points, an object of the present invention is to
An object of the present invention is to provide a method for driving an inkjet recording head in which the power consumed for controlling preliminary ejection of ink is reduced as much as possible.

[0012]

In order to achieve such an object, the present invention, when driving a recording head in an ink jet recording apparatus, after turning off a specific power source of the ink jet recording apparatus, measuring its off time, The amount of preliminary ejection to be executed after the input of the key is changed depending on whether the input of the power-on key is received again within a predetermined time or the input of the key is received after the measurement of the predetermined time.

Here, it is preferable to adopt a control method in which the preliminary discharge amount is larger when the power-on key is received after the predetermined time is measured than when the key input is received within the predetermined time. Is.

[0014]

According to the above configuration of the present invention, by simplifying the method of determining the preliminary discharge amount as compared with the conventional method, after a predetermined time has passed, only the minimum necessary circuits are energized to suppress power consumption. You can

[0015]

In the embodiments of the present invention described in detail below, in an ink jet recording apparatus having an auto power off function for avoiding power consumption, after the auto power off or the OFF key turns off, that is, the operation of the recording apparatus. After apparently turning off the power by turning off the display or turning off the display, the built-in arithmetic and control unit measures a fixed time, and when the ON key input is received within that fixed time, The amount of the preliminary discharge executed after the ON key is input is changed according to the case where it is received after the timing of. As a result, after measuring a certain time, driving of the DC / DC converter circuit for supplying electric power from the battery to each unit is stopped, power consumption in the DC / DC converter circuit is prevented, and calculation is performed until the ON key is received again. By setting the control device in the low power consumption mode, it is possible to drive the inkjet recording head even with a small capacity battery such as a dry battery.

Each embodiment of the present invention will be described in detail below with reference to the drawings.

Embodiment 1 FIG. 1 is a diagram showing a correspondence relationship between the amount of preliminary ejection N and the time from the input of the OFF key until the input of the ON key is received after the auto power off or the input of the OFF key in this embodiment. Is. In this figure, the broken line indicates the conventionally known preliminary ejection amount (see FIG. 7).

As shown in FIG. 1, conventionally, the time T
On the other hand, since the preliminary discharge amount has a substantially linear change, it is necessary to have a very high accuracy with respect to timing. Therefore, an arithmetic and control unit having a time counting function is required, or an LSI dedicated to the time counting function is added. However, in order to operate the clock function, power is consumed even when it is off.

On the other hand, in this embodiment, T _max
Since the number of preliminary discharges is simplified to n times and n _max at the boundary, there is no need for an accurate time counting function and a time counting above T _max . However, although the ink is consumed for the preliminary ejection more than the conventional one by the shaded area, the amount is smaller than the amount of ink consumed during actual printing, and one ink head It does not have a great influence on the print life that can be printed with. On the other hand, with respect to clogging, a greater recovery power is provided, and battery operability enables improved portability, downsizing, and cost reduction.

FIG. 2 is a perspective view of a printer-equipped computer 201 equipped with the ink jet recording apparatus according to the present invention. In the figure, 202 is a display unit, 203 is an OFF key, 204 is an ON key, 205 is a keyboard including other keys as a group, 206 is an inkjet recording head, 20
Reference numeral 7 denotes an ink absorber for absorbing the ink for preliminary ejection,
Reference numeral 208 represents a printer unit, and 209 represents recording paper.

FIG. 3 is an electric block diagram of the printer-equipped computer shown in FIG. In the figure, reference numeral 301 denotes a calculation control unit (MPU), which performs calculation processing in a computer, a keyboard 302, a printer 208, and a display 303.
Controls each part while exchanging signals with the like. This M
The PU 301 is a RAM 301 used for a work area in each process, a buffer for print processing, and the like, as well as a ROM 301B for storing the processing procedure detailed in FIG.
A and timer TMR3 that counts a fixed time
Has 01C.

Reference numeral 307 denotes a driver IC for driving a stepping motor included in the printer unit, 308.
Is a drive IC for driving the inkjet recording head
Is. Reference numeral 305 represents a battery (four batteries). Reference numeral 306 denotes a DC / DC converter circuit for inputting the output voltage of the four batteries 305 and converting it into a voltage required for each unit. This D
The driving of the C / DC converter circuit 306 is controlled by the PCNT signal from the MPU 301.

[0023] When the driving by PCNT signal is not restrained is, V _CC as the MPU supply, V _M which is a stepping motor power, even when there is no consumption of V _H as the ink jet recording head power, DC / DC converter circuit 306 It consumes its own power.

Reference numeral 310 denotes a diode, the DC / DC converter circuit 306 is stopped in response to the PCNT signal,
When the MPU301 enters the low power consumption mode, the battery 3
This is for supplying electric power to the MPU 301 directly from 05. When the MPU 301 enters the low power consumption mode, its power supply voltage range is widened, and the direct drive of the battery becomes possible. Reference numeral 309 is a capacitor for backup.

FIG. 4 shows the driving electric circuit of the ink jet recording head in detail. In this figure,
In the recording head drive IC 308 which receives the signal from the MPU 301 at the input end I _n , the transistor T _r therein is turned on. Then, from the power source V _H to the heater r _{0 of the} recording head.
A current I _H flows into the transistor T _r via the output port O ₀ and the heater r ₀ to generate heat to cause bubbling of the ink, and an ink droplet is ejected from the ejection port.

FIG. 5 is a flow chart showing an OFF process (a) and an ON key process (b) built in the ROM 301B.

The OFF process shown in FIG. 5A may be started by automatic power off or by pressing the OFF key. First, in step S501, general OFF processing such as printer OFF processing, display OFF processing, and memory flag OFF processing is performed.

In step S502, a timer TMR301C for counting a fixed time after turning off is started.

In step S503, the input of the ON key is checked, and if there is, the N _max flag is turned off in step S508, and the process jumps to the ON key processing.

When there is no ON key input in step S503, it is determined whether or not the timer has reached a certain time (T _max ). If not, the process returns to step S503 and loops. On the other hand, when the timer reaches T _max , the N _max flag is turned on in step S505, and further step S
At 506, the PCNT signal is turned on to stop driving the DC / DC converter circuit 306.

In step S507, a process for bringing the MPU 301 into a sleep mode, which is a low power consumption mode, is executed. It should be noted that the MPU 301 in slip mode
Is turned on by pressing the ON key to return to the normal mode.
Perform key processing.

In the ON key processing of FIG. 5, step S
Reference numeral 509 indicates general initialization processing after the ON key such as memory flag initialization, display initialization, printer initialization, etc.
N processing is executed.

In step S510, it is determined whether the N _max flag is turned on or off. If it is turned on, preliminary ejection of N _{max is} issued in step S511, and if it is turned off, step S51 is performed.
In 2, the preliminary ejection of n shots is executed, and the process jumps to the key input waiting process to wait for the next process.

Embodiment 2 In the embodiment described so far, the timer 301C built in the MPU 301 measures the fixed time, but as shown in FIG. It is also possible to use the / D converter 380.

That is, in FIG. 8A, the switch SW1 is closed through the port P1 when the off key is pressed or when the auto power is turned off. At this time, the switch SW2 is opened by the action of the port P3. When the switch SW1 is closed, the minute current i _R is charged in the capacitor C through R having a large resistance value.
The charging voltage V _C of the capacitor C which changes with the charging time T is shown in FIG.

When the ON key is pressed, the switch SW1 is opened, and the charging voltage V _C of the capacitor C is read by the A / D converter 380 via the port P2. The flag N _max is turned on / off depending on whether or not the A / D converted data is _equal to or more than V _cm corresponding to the constant time T _max .

After reading the charging voltage V _C of the capacitor C, the switch SW2 is closed via the port P3 and the capacitor C is discharged through the resistor r having a small resistance value.

In the method described above, when measuring the constant time T _max , the accuracy is lacked due to variations in the battery voltage and the values of C and R, but the MPU is set in the low power consumption mode even during the fixed time measurement. (Sleep mode) can be set.

(Others) The present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating heat energy as energy used for ejecting ink, particularly in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
Although it can be applied to any of the continuous type, in particular, in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, further excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the apparatus main body or the electrical connection to the apparatus main body or the ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add the ejection recovery means of the recording head, the auxiliary auxiliary means, etc. because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or below and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change from the solid state of the ink to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying heat energy such as ink that is liquefied by applying heat energy according to the recording signal and liquid ink is ejected or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as the form of the ink jet recording apparatus of the present invention, other than the one used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function can be used. It may be a form or the like.

[0048]

As described above, according to the present invention, when the input of the ON key is received within a predetermined time after the automatic power-off or the OFF by the OFF key, and when the ON key is input after the predetermined time has elapsed. The configuration is such that a simple preliminary discharge control is performed by changing the amount of preliminary discharge to be executed after the ON key is input. Therefore, for example, the driving of the DC / DC converter circuit is stopped and the arithmetic and control unit is operated. It is possible to reduce the power consumption by, for example, setting the low power consumption mode. As a result, even a small capacity battery such as a dry battery can be driven,
The C-code is not required, the power supply circuit can be made small, the entire device can be downsized, the portability can be improved, and the manufacturing cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a correspondence relationship between a time until receiving an ON key input and a preliminary ejection amount in one embodiment of the present invention.

FIG. 2 is an external view of a computer with a printer according to the present invention.

3 is an electrical block diagram of the printer-equipped computer shown in FIG. 2. FIG.

FIG. 4 is a detailed explanatory diagram showing a drive electric circuit of the inkjet recording head.

FIG. 5 is a flowchart showing a control procedure of this embodiment.

FIG. 6 is an explanatory diagram of a structure of an inkjet recording head.

FIG. 7 is a diagram showing a correspondence relationship between a time when a head is not driven and a preliminary ejection amount in a conventional example.

FIG. 8 is an explanatory diagram of another embodiment of the present invention.

[Explanation of symbols]

 209 Printer 301 MPU 302 Keyboard 303 Display 305 Battery 306 DC / DC converter

Claims (4)

[Claims] 1. When driving a recording head of an ink jet recording apparatus, after turning off a specific power source of the ink jet recording apparatus, the off time is measured, and the input of a power-on key is received again within a predetermined time. A method for driving an inkjet recording head, wherein the amount of preliminary ejection to be executed after inputting the key is changed depending on whether the input of the key is received after measuring a predetermined time. 2. The pre-ejection amount according to claim 1, wherein the pre-discharge amount is larger when the power-on key is received after the predetermined time is measured than when the key input is received within the predetermined time. And a method for driving an inkjet recording head. 3. The method for driving an inkjet recording head according to claim 1, wherein the inkjet recording head performs recording by ejecting ink droplets due to growth / contraction of bubbles. 4. The method for driving an ink jet recording head according to claim 1, wherein the ink jet recording apparatus uses a battery as an operating power source.