JP2003211670A - Recording method and recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermal ink jet printer in which such a phenomenon as the head is clogged and rendered unrestorable when the printer is not used for a long term is prevented, and to prevent waste of ink by stopping ink ejection when the nozzle of a thermal ink jet head is prevented from clogging. <P>SOLUTION: In a thermal ink jet printer, the thermal ink jet head is subjected to preliminary thermal driving periodically or unperiodically at the time of nonrecording by supplying it with power low enough not to eject ink. Preliminary thermal driving is performed by supplying the thermal ink jet head with a pulse of (1) such a pulse width or (2) such a voltage as not ejecting ink. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal ink jet recording apparatus for ejecting ink to record on a recording medium, and a thermal ink jet recording method.

As a recording apparatus to which the present invention is suitable, for example, a printer used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader, a Japanese word processor having a key input function, It includes an electronic typewriter, and a facsimile device having a transmission / reception function.

[0003]

2. Description of the Related Art An ink jet recording method is a recording method in which ejection droplets of ink are formed by various methods and are adhered to a recording medium such as paper for recording. In particular, the inkjet recording apparatus that uses heat as energy for forming discharged droplets has an excellent feature that a high-resolution and high-quality image can be obtained at high speed because a high-density multi-nozzle can be realized. ing.

In this type of ink jet recording apparatus, heat is generated by supplying a plurality of droplet forming means for ejecting ink droplets from an ejection port by applying thermal energy to the ink, that is, a current pulse. For a line printer, a plurality of droplet forming means having an electrothermal converter capable of heating an electrothermal converter and a plurality of integrated circuits (driving ICs) for driving the electrothermal converter are arranged on the same substrate. There is a recording head, that is, a so-called full-multi type recording head in which ejection ports are aligned over the entire width of a recording medium.

By the way, in this kind of apparatus, since the recording liquid (hereinafter referred to as ink) is directly ejected from the ejection port of the recording head to perform the recording, in order to always keep the ink in the ejectable state, the recording of another method is performed. It may require special consideration not found in the device.

That is, since the ink remains in the liquid passage of the recording head even during non-recording, it is necessary to take measures to prevent the ink in the liquid passage from being dried or being deteriorated due to evaporation. Therefore, for this reason, when the recording is not performed, the ejection port of the recording head is covered with a lid to dry the ink,
A device provided with a so-called capping means for preventing evaporation is known.

However, in a low-humidity environment, or when the apparatus is stopped for a long period of time, it may be unavoidable to increase the viscosity of the ink only by the above-mentioned drying preventing means. Therefore,
Along with the capping means described above, the air in the cap that covers the recording head is sucked and a negative pressure is applied from the discharge port so as to suck out the ink that has stagnated in the liquid path of the head, or the ink is discharged using a pump or the like. By applying pressure to the supply system, it is possible to discharge the deteriorated ink from the discharge port, or a part other than the recording medium,
For example, a recovery mechanism has been used in which the capping means is caused to eject ink (also called idle ejection) from all ejection ports to eject the thickened ink in the liquid passage.

[0008]

However, such a recovery mechanism is generally driven automatically when the power is turned on, etc. In general, in order to save the ink consumption during the recording operation, the recovery mechanism is driven at the longest possible interval. It is desirable to do. However, in order to cope with the deterioration of the ink in the liquid path which is not related to the driving during the printing operation, the printing operation is frequently interrupted at a short interval to perform the ejection recovery process, but as a result, the printing process efficiency is lowered. It will be.

Particularly, in a liquid jet recording apparatus using a recording head in which a large number of ejection openings are arranged in a line, there are ejection openings that are rarely used for printing depending on the statistical properties of the printing data, and therefore the ejection interval is very large. There are variations in the ejection drive such that it becomes longer. Therefore, the ink in the liquid path when the number of ejections is small or the ejection interval is long, the viscosity of the ink increases due to drying depending on the atmospheric conditions such as humidity and temperature, and the ink ejection from the ejection port becomes unstable, In addition, there is a risk that ejection may become impossible.

It is an object of the present invention to provide an ink jet recording apparatus and a recording method which perform stable quality recording and do not waste ink. That is, (1) It is possible to prevent the phenomenon that the head becomes stuck and cannot be recovered when the printer is not used for a long time. (2) When the nozzles of the thermal inkjet head are prevented from being clogged, the ink is not ejected, so the ink is not wasted.

[0011]

In order to achieve the above-mentioned object, the recording apparatus of the present invention has the following constitution. That is, a plurality of heat generating elements and a plurality of ink discharge ports provided corresponding to the plurality of heat generating elements are provided, and the ink is discharged from the ink discharge ports by causing a state change in the ink due to heat generated by energization of the heat generating elements. In a recording apparatus for recording an image on a recording material by using a recording head that discharges the ink, a driving unit that energizes the plurality of heating elements according to the recording data, and a supply unit that supplies the recording data to the recording unit. The supply means preliminarily heats and drives the plurality of heating elements by supplying electric power to the plurality of heating elements at regular or irregular intervals during non-recording.

The preheating drive is performed by giving a pulse of (1) pulse width or (2) voltage pulse to the extent that ink is not ejected to the thermal ink jet head.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION <Embodiment 1> Hereinafter, a preferred embodiment 1 of the present invention will be described in detail with reference to FIGS.

FIG. 3 is a block diagram showing the configuration of an ink jet printer 300 which is an example of the recording apparatus according to the first embodiment of the present invention.

Hereinafter, the ink jet printer 300 will be described.
The configuration of will be described. A CPU 301 controls the entire printer 300, a ROM 302 stores a control program executed by the CPU 301 and various data, and a RAM 303 is used as a work area during various control processes by the CPU 301 and temporarily stores each data. To save it. An A / D converter (A / D C) 305 converts an analog signal input from a LICC 311 described later into a digital signal and inputs the digital signal to the CPU 301. Three
Reference numeral 06 denotes an interface unit (I / F), which is used for the inkjet printer 300 and the host computer (HOST).
It controls the exchange of data with the PC 200. 307 is a gate array (GA), which is the CPU 301.
The image data for printing received from the device is subjected to horizontal-vertical conversion (HV conversion) according to the nozzle arrangement of the print head 315, and the converted recording data is output to the print head 315 in synchronization with the movement of the print head 315. is doing.

A memory (DRAM) 308 is used to temporarily store the image data when the gate array 307 converts the image data into HV. It is also used as a buffer for temporarily storing the print data output from the gate array 307 to the print head 315. The print head 315 has, for example, a plurality of ink jet heads that eject ink of a plurality of colors, receives the print data H-V converted by the gate array 307, and outputs the print data from the corresponding print heads according to the print data. An image is recorded by ejecting ink. LI
The CC 311 outputs to the A / D converter 305 a rank signal indicating the individual difference in the resistance value of the print head 315 and a temperature signal indicating the temperature of the print head 315.
The data (rank data and temperature data) converted into a digital signal by the D converter 305 is input to the CPU 301.

A main power switch 316 is a main power supply (low voltage power supply 31) of the ink jet printer 300.
It is a switch for turning on / off 7). 330
Is a printer power soft switch, and this switch 330
By pressing, the soft power on / off of the printer 300 can be performed. Reference numeral 331 is an auxiliary power supply, which includes, for example, a battery or the like, and prevents malfunction due to momentary interruption of the low-voltage power supply 317.

[Structure of Inkjet Recording Head] FIG. 2
FIG. 3 is a partially cutaway perspective view of an inkjet recording head to which the present invention can be applied.

Reference numeral 54 is a heating resistor, which generates heat in response to energization, causes film boiling of the ink to generate bubbles in the ink, and causes ink to be ejected by growth / contraction of the bubbles. The electrothermal conversion element 7 is constructed. The heating resistor 54 is formed on the substrate 51 together with the wiring through the same manufacturing process as that of the semiconductor. 52A is a liquid path forming member, which corresponds to the heating resistor 54
And the liquid path 53 communicating with this is formed. Also, 56
Is a top plate and covers the liquid path forming member. Furthermore, 55
Is a liquid chamber that communicates with each liquid passage 53 in common, and stores ink supplied from an ink supply source (not shown) in the recording head.

[Description of Printing Operation of Inkjet Printer 300] When a print job is received from the host computer 200 via the interface section 306,
The gate array (GA) 307 notifies the CPU 301 that the print job has been received. Gate array 3
Reference numeral 07 denotes HV conversion of the image data received from the host computer 200 via the interface unit 306, and outputs the print data generated thereby to the print head 315 which ejects ink. This gate array 3
07 uses the DRAM 308 as a buffer for H-V converting the received image data and for storing print data to be output to the print head 315.

In this way, the print head 3 according to the recording data.
By driving 15, the ink is ejected from the print head 315 to a recording medium (paper or the like) to print. At this time, the CPU 301 receives the rank data, which is the individual difference data of the resistance value of the print head 315 sent from the LICC 311 via the A / D converter 305, and the temperature data of the print head 315. The drive of the print head 315 is controlled based on the information of the print head 315 thus obtained, and an image is recorded.

Next, the operation of the ink jet printer according to this embodiment will be described with reference to the flowchart of FIG.

FIG. 1 is a flowchart showing the control processing by the CPU 301 of the ink jet printer 300 according to this embodiment.

In FIG. 1, first in step S101,
When the printer power supply soft switch 330 is turned on, the process proceeds to step S102, and the CPU 301 of the inkjet printer 300 performs initialization processing of the printer 300 at power-on such as wiping of the inkjet recording head. Wiping of the inkjet recording head is a process of cleaning the surface of the nozzle with a wiper in order to remove the ink clogging and dust of the head.

Then, in step S103, it is checked whether a print signal is received from the host computer 200,
When the print head 315 is received, the process proceeds to step S104.
Drive to print.

When the print signal from the host computer 200 is not received in step S103, the count value t _c of the timer 309 preheats the head in step S106 unless the printer power soft switch 330 is turned off in step S105. It regularly monitors whether or not the set value t _{0 of the} timer 309 that determines the driving interval becomes equal to or greater than the set value t ₀ . When the count value t _c of the timer 309 becomes equal to or greater than the set value t _{0 of the} timer 309 that determines the interval for preheating the head in step S106, step S107
Preheating is performed with a pulse width shorter than that during printing. In step S110, the count value t _c of the timer 309 is set to 0. Then, in step S103, the reception of a print signal from the host computer 200 is awaited.

When the printer power supply soft switch 330 is turned off in step S105 when the print signal from the host computer 200 is not received in step S103, the process proceeds to step S108, and the low voltage power supply 317 of the ink jet printer 300 is turned off. To

As described above, according to the first embodiment, the following effects can be obtained.

(1) It is possible to prevent the phenomenon that the head becomes stuck and cannot be recovered when the printer is not used for a long time.

(2) No ink is wasted because no ink is ejected when the nozzles of the thermal ink jet head are prevented from clogging.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, the structure of the ink jet recording head is shown in FIG. 2 and is the same as that of the first embodiment. A block diagram showing the configuration of the inkjet printer 300 is FIG. 3 and is similar to that of the first embodiment. Here, the low voltage power supply 317 is instructed by the CPU 301.
Is characterized in that the head drive voltage can be output lower than during printing.

FIG. 4 is a flowchart showing the control processing by the CPU 301 of the ink jet printer 300 according to this embodiment.

When the count value t _c of the timer 309 becomes equal to or larger than the set value t _{0 of the} timer 309 that determines the interval for preheating the head in step S106, step S109
The feature is that pre-heating is performed at a lower voltage than during printing.

As described above, according to the second embodiment, the following effects can be obtained.

(1) It is possible to prevent the phenomenon that the head becomes stuck and cannot be recovered when the printer is not used for a long period of time.

(2) When the nozzles of the thermal ink jet head are prevented from being clogged, the ink is not discharged, so the ink is not wasted.

[0038]

As described above, the recording apparatus of the present invention,
According to the recording method, in a thermal inkjet printer, periodically or irregularly when not recording,
Preheating drive is performed by supplying power to the thermal inkjet head to the extent that ink is not ejected.
The following effects can be obtained by applying (1) a pulse width pulse or (2) voltage pulse to the thermal ink jet head so as not to eject ink.

(1) It is possible to prevent the phenomenon that the head becomes stuck and cannot be recovered when the printer is not used for a long period of time.

(2) No ink is wasted because no ink is ejected when the nozzles of the thermal ink jet head are prevented from being clogged.

[Brief description of drawings]

FIG. 1 is a flowchart showing processing by a CPU of an inkjet printer according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of the inkjet recording head according to Embodiments 1 and 2 of the invention.

FIG. 3 is a block diagram showing a configuration of an inkjet printer showing an example of the recording apparatus according to the first and second embodiments of the present invention.

FIG. 4 is a flowchart showing processing by the CPU of the inkjet printer according to the second embodiment of the present invention.

Claims (14)

[Claims] 1. A plurality of heat generating elements and a plurality of ink discharge ports provided corresponding to the plurality of heat generating elements, wherein a state change is caused in the ink due to heat generated by energization of the heat generating elements to discharge the ink. In a recording apparatus that records an image on a recording material using a recording head that ejects ink from an outlet, a driving unit that energizes the plurality of heating elements according to recording data, and recording data to the recording unit. And a supply unit for supplying the electric power to the plurality of heating elements such that ink is not ejected to the plurality of heating elements at regular or irregular intervals during pre-heating for preheating. Characteristic recording device. 2. The recording apparatus according to claim 1, wherein the recording head has ink discharge ports arranged in a line over the entire width of the recording material, and records an image on a line-by-line basis. 3. The recording apparatus can be set in a sleep mode in which a function or performance is limited to reduce power consumption, and in the sleep mode, ink is applied to the plurality of heating elements periodically or irregularly. 3. The recording apparatus according to claim 1, wherein the recording apparatus is preheated by supplying electric power that does not discharge the ink. 4. The recording apparatus according to claim 1, wherein the recording standby state is when the recording is not performed. 5. When performing the preheating driving, data for preheating driving is supplied to the driving means by supplying electric power to the plurality of heat generating elements so as not to eject ink. Item 5. The recording device according to any one of items 1 to 4. 6. The recording apparatus according to claim 1, wherein the preheating drive is performed by applying a pulse having a pulse width that does not eject ink to the plurality of heating elements. 7. The recording apparatus according to claim 1, wherein the preheating drive is performed by applying a pulse of a voltage that does not eject ink to the plurality of heating elements. 8. A plurality of heat generating elements and a plurality of ink discharge ports provided corresponding to the plurality of heat generating elements are provided, and a state change is caused in the ink by heat generated by energization of the heat generating elements to discharge the ink. In a recording method of recording an image on a recording material using a recording head that ejects ink from an outlet, a driving unit that energizes the plurality of heating elements according to the recording data, and recording data to the recording unit. And a supply unit for supplying the electric power to the plurality of heating elements such that ink is not ejected to the plurality of heating elements at regular or irregular intervals during pre-heating for preheating. Characteristic recording method. 9. The recording method according to claim 8, wherein the recording head has ink discharge ports arranged in a line over the entire width of the recording material, and records an image in units of lines. 10. The recording method can be set to a sleep mode in which a function or performance is limited to reduce power consumption, and in the sleep mode, ink is applied to the plurality of heating elements periodically or irregularly. The recording method according to claim 8 or 9, wherein preheating driving is performed by supplying electric power that does not discharge the ink. 11. The recording method according to claim 8, wherein the recording standby state is when the recording is not performed. 12. When the preheating is driven, data for preheating driving is supplied to the driving means by supplying electric power to the plurality of heating elements so that ink is not ejected. Item 12. The recording method according to any one of items 8 to 11. 13. The recording method according to claim 8, wherein the preheating drive is performed by applying a pulse having a pulse width that does not eject ink to the plurality of heating elements. 14. The recording method according to claim 8, wherein the preheating drive is performed by applying a pulse of a voltage that does not eject ink to the plurality of heating elements.